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000
FXUS64 KHUN 231118 AAA
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
618 AM CDT WED APR 23 2014

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 317 AM CDT WED APR 23 2014/
WATER VAPOR IMAGERY AND RAP H5 ANALYSIS INDICATED RIDGING IN PLACE
ACROSS MUCH OF THE CENTRAL CONUS THIS MORNING, WITH A DEPARTING LOW
OVER THE NORTHEAST, AND ANOTHER ONE ARRIVING IN THE PACNW. AT THE
SFC, THE COLD FRONT THAT BROUGHT SCATTERED SHOWERS AND STORMS TO THE
CWFA YESTERDAY HAS PUSHED SOUTH/EAST OF THE AREA AS OF 8Z, DRAPED
FROM THE MID-ATLANTIC SWWRD INTO THE NRN GOMEX. A 1020MB SFC HIGH WAS
ANCHORED OVER THE GREAT LAKES, WITH CLEAR SKIES/LIGHT WINDS IN PLACE
ACROSS MUCH OF THE OH/TN VALLEYS THIS MORNING. SOME PATCHY DENSE FOG
IS POSSIBLE IN FAR SOUTHERN/EASTERN AREAS THROUGH DAYBREAK TODAY,
WITH DEWPOINT DEPRESSIONS THERE OF 3 DEGREES OR LESS. FOG WILL
DISSIPATE SHORTLY AFTER SUNRISE WHEN MIXING ENSUES AND DRIER AIR
CONTINUES TO FILTER INTO THE AREA FROM THE NW.

TODAY AND TOMORROW WILL BE DRY AND WARM, AS THE SFC/UPPER RIDGING
SHIFTS EASTWARD ACROSS THE AREA INTO TOMORROW. AFTN HIGHS TODAY WILL
TOP OUT IN THE MIDDLE 70S, AND WITH SWRLY FLOW ALOFT TOMORROW, TEMPS
WILL LIKELY SURPASS THE 80-DEGREE MARK IN MANY AREAS. MORNING LOWS
THURSDAY WILL ONLY BOTTOM OUT BETWEEN 45-50F AS SOUTHERLY FLOW SETS
UP ACROSS THE REGION AHEAD OF THE NEXT WEATHERMAKER.

THIS FEATURE IS CURRENTLY COMING ASHORE IN THE PACNW THIS MORNING,
AND WILL TRAVERSE THE HIGH PLAINS THROUGH TOMORROW AFTERNOON,
INDUCING SFC CYCLOGENESIS OVER THE CENTRAL PLAINS. THE SFC LOW WILL
MOVE NE TOWARD THE GREAT LAKES, DRAGGING A COLD FRONT TOWARD THE
TN VALLEY THURSDAY NIGHT INTO FRIDAY. NAM/UKMET/GFS/ECMWF SHOW THE
BULK OF THE PCPN ASSOCIATED WITH THIS NEXT SYSTEM HOLDING OFF UNTIL
00Z FRIDAY. HAVE RETAINED THE 50-POPS FROM THE PREVIOUS SHIFT, WHICH
IS A GOOD CONSENSUS WITH THE VARYING ARRAY OF QPF FROM THE LATEST
MODEL RUNS. SOUNDINGS FOR THU NIGHT INTO FRIDAY SHOW THE POTENTIAL
FOR GUSTY WINDS AND MAYBE SOME HEAVY RAINFALL, BUT NOT MUCH ELSE.
INSTABILITY IS RATHER WEAK, BUT WILL KEEP THE MENTION OF 40MPH WINDS
IN THE HWO FOR NOW.

THE FRONT WILL HAVE PUSHED ACROSS THE AREA BY MIDDAY FRIDAY, WITH DRY
AND WARM CONDS EXPECTED AS HIGH PRESSURE QUICKLY BUILDS INTO THE
REGION FROM THE WEST. WARM AND DRY WILL BE THE RULE FOR
FRIDAY/SATURDAY, WITH AFTN HIGHS FLIRTING WITH 80F FRIDAY, AND 85F
SATURDAY. BY THIS TIME, AN UPPER LOW WILL HAVE COME ASHORE IN NRN
CA, AND WILL DEEPEN OVER THE INTERMOUNTAIN WEST BY SUNDAY AFTERNOON.
THIS WILL INDUCE SFC CYCLOGENESIS OVER THE LEE SIDE OF THE ROCKIES,
WITH THE POTENTIAL FOR SVR WX IN THE CENTRAL PLAINS/MID-MS RIVER
VALLEY SUNDAY NIGHT AND MONDAY.

FOR OUR AREA, THE PERIOD FROM MONDAY EVENING THROUGH TUESDAY MORNING IS
SHAPING UP TO BE A STORMY ONE, WITH STRONG TO POSSIBLY SEVERE STORMS
DEVELOPING AND OVERSPREADING THE AREA FROM THE ARKLAMISS. A SECONDARY
VORT MAX WILL ROUND THE BASE OF THE TROF TO THE WEST, DEVELOPING
ANOTHER SFC LOW CLOSER/JUST NW OF OUR AREA DURING THIS TIME. FOR
NOW, HAVE INCREASED POPS, BUT THE EVENTUAL EVOLUTION/STORM MODE IS
STILL UNCERTAIN AT THIS POINT. THE GFS/ECMWF HAVE QUITE DIFFERENT
SOLUTIONS REGARDING STRENGTH/PLACEMENT OF UPPER LEVEL FEATURES, BUT
PARAMETERS HAVE STRENGTHENED FROM THIS TIME YESTERDAY, WITH THE
POTENTIAL FOR DAMAGING WINDS INCREASING DURING THIS TIMEFRAME. 0-1KM
SHEAR VALUES OF 50KTS COUPLED WITH 300-400 M2/S2 0-1 HELICITY RAISES
A RED FLAG, AS WELL AS AN 850MB JET INCREASING TO 60KTS OVERNIGHT
MONDAY INTO TUESDAY. LCLS ARE ALSO RATHER LOW DURING THIS TIME, BUT
AM NOT GOING TO FORMALLY MENTION THE `T-WORD` JUST YET (WILL AWAIT
BETTER MODEL AGREEMENT BEFORE THAT HAPPENS). FOR NOW, WILL ENHANCE
THE WORDING IN THE HWO FOR THE POTENTIAL FOR DAMAGING WINDS. AFTER
THE MONDAY/TUESDAY TIMEFRAME, BOTH THE ECMWF/GFS SHOW THE UPPER LOW
THEN WOBBLING OVER THE OH/TN VALLEYS FOR THE LATTER HALF OF THE WEEK,
WITH COOLER TEMPS RETURNING. TEMPS WEREN`T DRASTICALLY CHANGED FROM
YESTERDAY, BUT THE AFTN HIGHS FORECAST NEXT WEDNESDAY IN THE MIDDLE
60S ARE PROBABLY TOO OPTIMISTIC (WITH A 1030-1040MB HIGH EXPECTED TO
SURGE SOUTHWARD IN THE WAKE OF THE DEPARTING UPPER LOW, IF THE ECMWF
VERIFIES). DON`T PUT THOSE JACKETS AWAY JUST YET!

12

&&

.AVIATION...
FOR 12Z TAFS... VFR CONDITIONS ARE FORECAST DURING THE NEXT 24 HOURS.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

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AT WEATHER.GOV/HUNTSVILLE.