Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 211724 AAC
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
1224 PM CDT MON APR 21 2014

.UPDATE...
CLOUD COVER TO THE NORTH IS HOLDING TOGETHER BETTER THAN
PREVIOUSLY EXPECTED...SO HAVE INCREASED THE SKY COVER SOME ACROSS
THE NORTHERN CWA FOR THIS AFTERNOON. OTHERWISE...NO CHANGES MADE
TO THE FORECAST AT THIS TIME.

18Z TAF DISCUSSION INCLUDED BELOW...

&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH WEDNESDAY
FIRE WEATHER CONDITIONS TODAY AND TUESDAY WILL BE THE MAIN
FORECAST CHALLENGE.

AN AREA OF LOW PRESSURE OVER NORTHERN MINNESOTA WILL CONTINUE
TRACKING EAST OF THE REGION TODAY. A WEAK COLD FRONT ON THE
BACKSIDE OF THE LOW PRESSURE WILL SLIDE ACROSS THIS CWA LATER
THIS AFTERNOON BRING COOLER TEMPERATURES ALONG WITH BREEZY
NORTHWESTERLY WINDS. SUSTAINED WINDS OF 15 TO 25 MPH WILL BE
POSSIBLE BY PEAK HEATING ALONG WITH A FEW GUSTS EXCEEDING 30 MPH.
THESE WIND SPEEDS ARE WITHIN RED FLAG CRITERIA. THE BIGGEST
CHALLENGE WILL BE DEW POINTS AND HOW LOW RH VALUES FALL THIS
AFTERNOON. SEVERAL MODELS ARE SHOWING LLM POOLING ALONG THE COLD
FRONT THIS AFTERNOON WITH DEW POINTS IN THE MID 30S BETWEEN
18-21Z. IF THESE DEW POINTS ACTUALLY MATERIALIZE...THEN RH VALUES
WILL REMAIN IN THE 30 PERCENT RANGE...OR ABOVE RED FLAG CRITERIA.
EVEN THOUGH FIRE WEATHER CONDITIONS ARE MARGINAL...WILL ISSUE A
RED FLAG WARNING FOR ALL FIRE WX ZONES ALONG AND EAST OF THE JAMES
RIVER.

A STRENGTHENING LOW PRESSURE SYSTEM WEST OF THE REGION WILL BRING
INCREASING WINDS TO THE MISSOURI RIVER VALLEY ON TUESDAY.
SUSTAINED WINDS OF 20 MPH WITH GUSTS EXCEEDING 30 MPH ARE HIGHLY
POSSIBLE. HIGH TEMPERATURES SHOULD WARM INTO THE 70S AND LOWER
80S WITH DEW POINTS IN THE LOWER 40S. THE COMBINATION OF STRONG
WINDS AND LOW RH VALUES WILL PROMOTE ANOTHER POTENTIAL FIRE
WEATHER DAY. WITH FIRE WEATHER CONDITIONS IN THE EAST TODAY...WILL
HOLD OFF ON ADDING ADDITIONAL HEADLINES.

THE LOW PRESSURE SYSTEM WILL SLIDE ACROSS THE REGION TUESDAY NIGHT
AND WEDNESDAY. THIS SYSTEM WILL BRING A DECENT CHANCE FOR SHOWERS
AND PERHAPS A FEW THUNDERSTORMS...MAINLY FOR THE EASTERN HALF OF
THE CWA. DRY CONDITIONS OVER THE PAST MONTH HAS LEAD TO A
PRECIPITATION DEFICIT OF ONE TO TWO INCHES ACROSS MOST OF THIS
CWA. HOPEFULLY THIS STORM SYSTEM WILL BRING THE REGION CLOSER TO
NORMAL.



.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
A SLIGHTLY PROGRESSIVE YET AMPLIFIED PATTERN IS EXPECTED FOR MOST
OF THE LONG TERM. AT THE BEGINNING OF THE PERIOD A MAJOR MID LEVEL
TROF WILL BE LIFTING NORTHEAST INTO THE NORTHERN PLAINS. THE MAIN
CHANCES FOR PCPN WITH THIS SYSTEM SHOULD BE WEDNESDAY THROUGH
THURSDAY NIGHT...AND ESPECIALLY OVER THE EASTERN DAKOTAS AND
MINNESOTA...THE WESTERN PART OF SOUTH DAKOTA GETS PRETTY MUCH DRY
SLOTTED. BASED ON STABILITY/MOISTURE PROGS IT APPEARS THERE IS
STILL SOME CHANCE FOR THUNDER...BUT GENERALLY SPEAKING AM NOT
LOOKING FOR ANY SVR WEATHER. THAT SYSTEM MOVES OFF TO THE
NORTH/EAST ON FRIDAY WITH ANOTHER SYSTEM MOVING ACROSS THE
WESTERN/CENTRAL CONUS THIS WEEKEND. THAT ENERGY IS HANDLED
DIFFERENTLY IN THE MODELS WITH THE ECMWF LOOKING MUCH WETTER
ACROSS THE FORECAST AREA GIVEN A FURTHER NORTH MID LEVEL TROF AND
STRONGER BAROCLINIC ZONE VS THE GFS WHICH PROVIDES A BLOCKING SFC
HIGH...THUS KEEPING PCPN AT BAY OVER MOST OF THE NORTHERN/EASTERN
CWA. HARD TO SAY WHICH IS CORRECT AT THIS POINT. TEMPERATURES
MEANWHILE WILL AVERAGE BELOW NORMAL FOR MOST OF THE
PERIOD...ESPECIALLY IF THE PCPN FORECAST BY THE ECMWF MATERIALIZES
NEXT WEEKEND.




&&

.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

VFR SKIES/VISBYS EXPECTED FOR ALL TAF SITES. NORTHWEST BREEZE WILL
DIMINISH LATE THIS AFTERNOON/EVENING. WINDS WILL SHIFT AROUND TO
THE SOUTHEAST OVERNIGHT/EARLY TUESDAY.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR PRAIRIE COTEAU-
     RED RIVER VALLEY-UPPER JAMES RIVER.

MN...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR BIG STONE-
     TRAVERSE.

&&

$$
UPDATE...PARKIN
SHORT TERM...SD
LONG TERM...TDK
AVIATION...CONNELLY

WEATHER.GOV/ABERDEEN





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