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Offline WeatherHost

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Area Forecast Discussion
« on: November 02, 2018, 12:36:17 PM »
Is the AFD for your area in English or gibberish?

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Offline saratogaWX

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Re: Area Forecast Discussion
« Reply #1 on: November 02, 2018, 12:50:56 PM »
Mine looks to be good (in English)
Code: [Select]
000
FXUS66 KMTR 021616
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
916 AM PDT Fri Nov 2 2018

.SYNOPSIS...Another mild day across the Bay Area as high pressure
remains off the California Coast. Offshore flow will increase
Friday night into Saturday with decreasing humidity. In the longer
range, dry conditions, warmer than normal temperatures, and
periods of offshore winds are forecast to continue through next
week. Some hints of possible rain chances by Veterans Day Weekend.

&&

.DISCUSSION...as of 09:10 AM PDT Friday...Upper level ridge has
flattened somewhat overnight in response to a shortwave trough
moving through the Pacific Northwest. The North Bay and locations
along the coast will see slight cooling due to the trough while
other areas will see similar temperatures to yesterday with highs
above normal. Currently seeing a narrow band of stratus just off
the coast from Pt. Reyes southward. However the stratus is
pushing onshore locally near San Francisco and Half Moon Bay.

Main weather impact/focus today will be on Fire Weather
conditions tonight through Sunday morning. The trough will act to
increase offshore flow as a surface high builds into Oregon and
Great Basin while lower pressure remains along the coast. The
offshore flow will bring in very dry air especially to the higher
terrain. The strongest winds will be between 12-18Z Saturday
morning over the higher terrain of Napa and eastern Sonoma
Counties and the East Bay Hills. Relative humidity will drop to
critically low values in these areas with RH in the single digits
possible during the day on Saturday. Please see the previous
discussion and Fire Weather section for more details. No updates
planned this morning.

&&

.PREV DISCUSSION...as of 2:58 AM PDT Friday...Main weather
impacts to the Bay Area over the next seven days will be Fire
Weather focused with another offshore flow event.

The broad high pressure parked off the California Coast will
flatten a little today as a disturbance pushes into Pac NW. The
aforementioned disturbance can easily be seen on the water vapor.
So what does this mean for the Bay Area? Two things, slight
cooldown and setting the stage for offshore flow. In the short
term, expect another mild day around the Bay Area with widespread
70s and 80s. The flattening ridge will bring subtle cooling to the
immediate coast, but despite the cooling the temps will remain
above normal. The passing disturbance will push through today and
early tonight. In its wake surface high pressure will build over
Oregon and eventually portions of the Great Basin. This is a
classic set up for offshore over the Bay Area - inland high
pressure and lower pressure at the coast. Latest forecast pressure
gradients peak a little under 10mb from SFO-WMC by Saturday
morning. Lack of strong upper level support and moderate surface
gradients will likely put this event in the moderate category.
None the less there will still be impacts from a fire weather
stand point and less of a widespread wind impact event.

Now for the details - 00Z hi-res models ramp up N to NE winds
across the higher terrain 06Z Saturday with the peak winds 12-18Z
Saturday. Winds of 15 to 30 mph with gusts 40-50 mph and locally
up to 50-60 mph. The 50-60 mph gusts will be possible at places
like Mt Diablo, Mt Saint Helena, Geyser Peak and Atlas Peak. As
the N/NE flow kicks in relative humidity will tumble and become
critically low. In fact, some models suggest single digit humidity
readings during the day Saturday. Therefore, upgraded the Fire
Weather Watch to a Red Flag Warning to account for the gusty
offshore flow and low relative humidity. If a fire gets started it
will easily spread under these conditions. The offshore flow will
also lead to even warmer temperatures on Saturday with widespread
80s across the interior.

Winds will gradually diminish late Saturday night into Sunday, but
the lack of humidity recovery will keep the fire weather threat in
place. Onshore flow returns on Sunday leading to a cooling trend.

As for next week, general high pressure remains off the California
Coast with periods of weak northerly flow. The storm track remains
to the north with mild and dry conditions.

Given another round of fire weather concerns the next logical
question would be, where`s the rain? There is some hope as longer
range models continue to indicate a patter shift and southern drop
of the storm track Nov 10-12. Lots can happen between now and
then, but will have to watch the pattern evolve.

&&

.AVIATION...as of 5:02 AM PDT Friday...A dry northerly flow and a
compressed marine inversion continues. Stratus and fog is brushing
the San Mateo Coast and more stratus far upstream is rounding the
corner of Cape Mendocino. Fog has reduced the visibility to less
than 1/4 mile /VLIFR/ and ceiling 200 feet at KHAF. The stratus
near Cape Mendocino is with a discontinuous and shallow cool
frontal boundary that`ll eventually sweep southward to the Central
Coast by early Saturday morning; patchy stratus and fog will remain
possible on the immediate coastline, otherwise it`ll be VFR.

WRF model forecasts marginal low level wind shear over the Bay
Area terminals Saturday morning.

Vicinity of KSFO...VFR. Light wind becoming NW-W 10 to 12 knots
this afternoon. Light wind late tonight, low level wind shear
forecast 12z-18z Saturday.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...VFR. Light E-SE winds except near 10 knots
in the Salinas Valley this morning. Wind becoming onshore 5 to 10
knots this afternoon shifting back to light E-SE tonight.

&&

.FIRE WEATHER...as of 3:15 AM PDT Friday...Fire Weather Watch has
been upgraded to a Red Flag Warning for late tonight through early
Sunday morning. The greatest impacts where fire weather conditions
will be most critical will be to locations above 1,000 feet for
the North Bay Mountains and East Bay Hills. Hi-res models have
really honed in on increasing winds after about 11 PM Friday and
peaking during the afternoon on Saturday. Winds will diminish
gradually Saturday night. Humidity values will recovery early
Friday night then drop through sunrise Saturday as NE flow kicks
in. Further drying is expected during the day Saturday with RH
dropping into the single digits. Winds may diminish Saturday
night, but RH recovery will remain poor and less than 30%. It
should be noted that even though the Santa Cruz Mts, Santa Lucia
Mts and southern Gabilan are not technically in the Red Flag
Warning, those locations will be near critical levels, just not as
as windy.

&&

.MARINE...as of 9:10 AM PDT Friday...Northerly winds will
increase across the coastal waters today and tomorrow. Winds will
remain gusty through early next week before gradually diminishing.
These winds will generate steep wind waves and fresh swell
resulting in hazardous seas conditions, especially for smaller
vessels. Mixed northwest and southerly swell will continue through
the forecast period.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...SCA...Pt Reyes to Pigeon Pt 0-10 nm from 3 PM
             SCA...Pigeon Pt to Pt Pinos 0-10 nm from 3 PM
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm from 3 PM
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 3 PM
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pt Arena to Pt Reyes 0-10 nm from 9 AM

&&

$$

PUBLIC FORECAST: ST/MM
AVIATION: W Pi/Canepa
MARINE: AS
FIRE WEATHER: MM

Visit us at www.weather.gov/sanfrancisco

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www.facebook.com/nwsbayarea
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« Last Edit: November 02, 2018, 12:53:06 PM by saratogaWX »
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Offline WeatherHost

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Re: Area Forecast Discussion
« Reply #2 on: November 02, 2018, 01:19:25 PM »
Ours for now is somewhere between:

"
Starting with the first system, a 500 mb shortwave will drop
south-southeast into the base of the large-scale trough axis over
the Mississippi Valley today. The leading edge of light rain is
forecast to reach the Ozark foothills during the midday hours. The
eastward extent of the rain is in doubt, but small chances of rain
will be maintained east of the Mississippi River late today and
this evening. The shortwave will essentially lose its identity as
it bottoms out in the base of the mean trough axis this evening.

Saturday remains the solitary dry day of the forecast. As the
first system moves away from our region, another 500 mb shortwave
will dig southeast into the Plains. Our region will be located
between systems under a weak 500 mb shortwave ridge. One potential
fly in the ointment is possible low clouds and fog during the
morning hours. The combination of clearing skies, light winds, and
moist ground could result in stratus or fog around sunrise Sat.
Once any low clouds burn off, warm advection mid clouds may
increase in the afternoon. While a sunny day is not anticipated,
there should be enough sun with south winds to attain highs
around 60."

It may be OK if you know what a '500 mb shortwave' is and how or why it matters, but most of the public does not.  I've seen them be much, much worse though, loaded with cryptic abbreviations that even the Glossary doesn't help with.

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Offline SLOweather

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Re: Area Forecast Discussion
« Reply #3 on: November 02, 2018, 01:25:20 PM »
Ours is OK...

AREA FORECAST DISCUSSION


 
 FXUS66 KLOX 021637
  AFDLOX
   
  Area Forecast Discussion
  National Weather Service Los Angeles/Oxnard CA 
  937 AM PDT Fri Nov 2 2018
   
  .SYNOPSIS...02/833 AM.
   
  High pressure combined with gusty offshore flow will continue to 
  bring warm and dry conditions to the area through the weekend. 
  Cooler temperatures are expected next week as the high pressure 
  weakens and onshore flow returns. Overnight low clouds and fog 
  will affect portions of the coast starting Monday.
   
  &&
   
  .SHORT TERM (TDY-SUN)...02/936 AM.
   
  High pressure aloft remains parked off the California coast but
  still some high clouds drifting over the top at times. Dry, warm
  offshore flow to continue through Sunday morning. Models still
  showing an increase in north northeast winds tonight and Saturday
  morning across SLO/SB counties but probably below advisory levels
  in most areas. Main impact will be to increase temps a few degrees 
  most areas which is a slight change from earlier thinking when 
  models had been leaning cooler for Saturday, especially at the
  coast. Instead expecting temps around 90 for parts of the Central
  Coast Saturday as well as many coast/valley locations down south. 
  Have a little patch of stratus drifting down the California coast 
  this morning but expect that will remain offshore and not impact 
  coastal areas.
   
  We`ll start seeing a change Sunday as gradients trend strongly
  onshore in the afternoon ahead of a trough moving into the Pac NW.
  This will bring cooling to most areas except the far interior but
  still well above normal temps.
   
  .LONG TERM (MON-THU)...02/159 AM.
   
  Overall, 00Z models continue to exhibit good synoptic agreement
  through the long-term period. At upper levels, ridge will flatten
  over the Eastern Pacific with a broad northwest flow developing
  over the area. Near the surface, onshore flow will prevail through
  the period although it will likely weaken by Thursday as surface
  high pressure strengthens a bit over the Great Basin.
   
  Forecast-wise, nothing too exciting for the area through next
  week. For Monday through Wednesday, the return of onshore flow as
  well as the flattening upper-level ridge will bring a cooling
  trend to all areas. Additionally, the marine layer stratus will
  make a return with the best stratus coverage likely across the
  coastal plain of Ventura and Los Angeles counties. For Wednesday
  night and Thursday, the weakening onshore gradients should allow
  for less extensive marine layer stratus as well as slightly
  warmer temperatures Thursday afternoon.
   
  &&
   
  .AVIATION...02/1623Z.
   
  At 16Z over KLAX, there was a surface based inversion. The top of
  the inversion was 1600 feet with a temperature of 24 degrees 
  Celsius.
   
  High confidence in VFR conditions through Saturday. Winds should
  be typical, except for the possibility of unusual NE winds 10-20
  KT tonight and Saturday at KSMX KSBP KPRB. 
   
  KLAX...High confidence in VFR through at least Saturday. Any east
  winds will stay below 8 KT. 
   
  KBUR...High confidence in VFR through at least Saturday.
   
  &&
   
  .MARINE...02/936 AM.
   
  Moderate confidence in Small Craft Advisory (SCA) conditions
  starting by this evening over the outer waters from the Central
  Coast to San Nicolas Island. These winds should continue through
  at least Saturday night, and could continue well into next week. 
  Dense fog has formed in the same area and may persist through the 
  weekend. To other significant impacts expected.
   
  &&
   
  .FIRE WEATHER...02/936 AM.
   
  Locally breezy offshore winds will continue to impact Los Angeles
  and Ventura counties through Sunday, with north to northeast winds
  gusting at times between 20 and 35 mph. North to northeast winds
  will also impact Santa Barbara and San Luis Obispo counties at times
  through the weekend. This pattern will maintain very warm and dry
  conditions through Saturday, with a few degrees of cooling by
  Sunday as onshore flow redevelops in the afternoon. Humidities will
  remain low today, then dry further tonight night through Sunday, especially
  at higher elevations where single digits are likely. Widespread elevated
  fire weather conditions will persist through Sunday as a result, especially
  where the winds are strongest. Brief and localized critical conditions are
  likely tonight through Sunday morning over portions of Santa Barbara and
  San Luis Obispo counties, especially the mountains, Central Coast, and
  adjacent foothills. Generally cooler but still dry conditions are
  expected next week as the ridge aloft weakens.
   
  &&
   
  .LOX WATCHES/WARNINGS/ADVISORIES...
  CA...NONE.
  PZ...Small Craft Advisory in effect from 3 PM PDT this afternoon
        to 3 AM PST Sunday for zones 670-673-676. (See LAXMWWLOX).
   
  &&
   
  .HAZARD POTENTIAL OUTLOOK (SUN-THU).
   
  No significant hazards expected.
   
  &&
   
 
$$

 
   
  PUBLIC...MW/Thompson
  AVIATION...Kittell
  MARINE...Kittell
  FIRE...Gomberg
  SYNOPSIS...Smith
   
  weather.gov/losangeles

Offline tmabell

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Re: Area Forecast Discussion
« Reply #4 on: November 03, 2018, 07:03:23 PM »
I may have misunderstood your question but I get the idea that you think that the general public should be able to easily understand the AFD's.  Perhaps, but these products have always been written in a way that is intended for the Meteorological community.  It is an "expert" version of the Regional Weather Synopsis which IS intended for the general public.  For many years these discussions were not available to the general public at all.

Here is an example of a product that is intended for the public:  https://forecast.weather.gov/product.php?issuedby=OKX&product=RWS&site=NWS

Perhaps those who want to know more about the terms used in the AFD could look here: https://forecast.weather.gov/product.php?site=ict&issuedby=ict&product=afd&format=ci&version=1&glossary=1.  A quick look here and you have often used terms highlighted with clickable links that provide explanations to each term.

I want to mention also that some AFD's begin with a "Synopsis" section that is perfect for non-meteorologists.  It is written in an easy to understand manner.

Hope this helps
« Last Edit: November 03, 2018, 07:06:04 PM by tmabell »

Offline CW2274

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Re: Area Forecast Discussion
« Reply #5 on: November 03, 2018, 07:25:15 PM »
What's so tough about educating ones self. If that's too difficult/time consuming, then move on to a more novice context. Thankfully, 'dumbing down' to the common denominator is not the discussion's purpose, some of us always want the 'devil in the details'. 

Offline Cutty Sark Sailor

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Re: Area Forecast Discussion
« Reply #6 on: November 04, 2018, 03:45:43 PM »
Some of it depends on 'who's writing it'...
heh...
I had these two references in one the other day:
"poleward of"
and
"on the equator side"  (or similar...I forget Exactly... it was bizarre, anyway)
... and wondered what was wrong with good ol' 'north and south'... in my hemisphere...
« Last Edit: November 04, 2018, 03:48:00 PM by Cutty Sark Sailor »
 

Offline ocala

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Re: Area Forecast Discussion
« Reply #7 on: November 04, 2018, 05:09:55 PM »
I don't claim to know everything they talk about but after reading them for many years I have a feel for what they are trying to say.
They can spend a whole paragraph just trying to say "partly cloudy with 50% chance of rain" but that's what I like about it. They use things like local knowledge, model consistency, upstream conditions etc etc. And a lot of times they get it wrong too but most of the time it's fairly accurate.
I also have the luxury of being on the extreme southern end of the Jacksonville CWA. 10 miles to my S is the Tampa CWA and 10 miles to my SE is the Melbourne CWA so I get to read each AFD. It's interesting to read how each office handles all the same data but sometimes come up with differing forecasts.


Offline WeatherHost

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Re: Area Forecast Discussion
« Reply #8 on: November 04, 2018, 05:33:24 PM »
It's interesting to read how each office handles all the same data but sometimes come up with differing forecasts.

It's called a dart board.


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Offline CW2274

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Re: Area Forecast Discussion
« Reply #9 on: November 04, 2018, 06:19:39 PM »
It's interesting to read how each office handles all the same data but sometimes come up with differing forecasts.

It's called a dart board.
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Offline WeatherHost

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Re: Area Forecast Discussion
« Reply #10 on: November 05, 2018, 06:42:41 AM »
"Our system of interest today is taking shape to our west, as a
potent shortwave is diving into the Central Plains along with a
surface low currently residing over the Oklahoma Panhandle.
Expecting dry conditions through the morning hours before a rapid
surge of moisture and warm air advection quickly develops a large of
showers and spreads them northeast through the afternoon hours.
Elevated instability develops by mid afternoon so may be some
rumbles of thunder with this activity.

As our southeast surface winds quickly switch to
south/southwest by around 00z, we should see dewpoints surge into
the upper 50s to low 60s generally along and south of the Ohio
River. There is some question as to the degree of sfc based
instability that can develop, with the afternoon convection perhaps
limiting the potential. However, most guidance is in good agreement
in depicting a small sliver of SBCAPE developing in portions of west
KY, generally south of a Paducah to Calhoun line. The time window is
short lived, maybe only for a couple hours at any one location.
Given the wind fields aloft (850mb jet of 60+ kts, 500mb jet of 90+
kts), and impressive SRH values (0-1 km 400+, 0-3 km 500+), we won`t
need much instability to get severe storms to develop. Storm mode
may take on a mixed mode of supercells and linear segments with
embedded circulations. Damaging winds will be the primary concern.
While the most robust updraft helicity swaths on the short-res
guidance are depicted just to our south in TN, there are some swaths
across west KY during the evening hours.
"

More Gibberish than English, but I think they're saying it's gonna rain and it might get stormy in some places.

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Offline tmabell

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Re: Area Forecast Discussion
« Reply #11 on: November 05, 2018, 10:17:30 AM »
That one is well written and makes perfect sense to me.  It's hard to know what your complaining about.
« Last Edit: November 05, 2018, 12:45:05 PM by tmabell »

Offline WeatherHost

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Re: Area Forecast Discussion
« Reply #12 on: November 05, 2018, 10:51:19 AM »
degree of sfc based instability

depicting a small sliver of SBCAPE

wind fields aloft (850mb jet of 60+ kts, 500mb jet of 90+
kts), and impressive SRH values (0-1 km 400+, 0-3 km 500+)


Walk in to a mall, grocery store or other public place and ask 10 people at random if they know what any of that means.

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Offline ocala

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Re: Area Forecast Discussion
« Reply #13 on: November 05, 2018, 11:38:25 AM »
I think it was explained above.
You have to educate yourself.

Offline Cutty Sark Sailor

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Re: Area Forecast Discussion
« Reply #14 on: November 05, 2018, 12:45:44 PM »
I think it was explained above.
You have to educate yourself.
Here's one shortcut:
https://w1.weather.gov/glossary/

...and we can continue to sit on the beach sipping a beverage and move on to exploring something really serious, like 'What is dark matter?".... :twisted:
« Last Edit: November 05, 2018, 12:47:33 PM by Cutty Sark Sailor »
 

Offline vreihen

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Re: Area Forecast Discussion
« Reply #15 on: November 05, 2018, 01:57:29 PM »
WU Gold Stars for everyone! :lol:

Offline catdon

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Re: Area Forecast Discussion
« Reply #16 on: November 06, 2018, 05:14:25 PM »
I like when the discussions really go into detail...It usually depends on which forecaster happens to be writing a particular discussion, Sometimes they go into great detail and at other times it seems like they couldn't be bothered... Obviously if the weather is active there is more to talk about but even then the different writing styles can be evident.
Don
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Offline vreihen

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Re: Area Forecast Discussion
« Reply #17 on: November 06, 2018, 07:04:10 PM »
I like when the discussions really go into detail...It usually depends on which forecaster happens to be writing a particular discussion, Sometimes they go into great detail and at other times it seems like they couldn't be bothered... Obviously if the weather is active there is more to talk about but even then the different writing styles can be evident.

https://forecast.weather.gov/product.php?site=OKX&issuedby=OKX&product=AFD&format=CI&version=1&glossary=1&highlight=off

I Assume that you are reading the exact same one as me, and that it ends with an equipment note that KWO35 is *still* off the air  #-o and has the initials of the forecaster(s) who wrote each section at the end.  I've been tempted to attend one of their open houses, just to put names/faces to the initials.

[For those who don't know, KWO35 is the NOAA weather radio station covering the largest population center (New York City and surrounding metro area) in the entire country.  It has been off the air for a few years now, because of radio interference with the Coast Guard on a shared tower at Rockefeller Center.....]
WU Gold Stars for everyone! :lol:

 

anything