Area Forecast Discussion
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274
FXUS62 KTAE 292007
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
407 PM EDT SUN MAR 29 2015

.NEAR TERM [THROUGH TONIGHT]...

SURFACE HIGH PRESSURE OVER THE CAROLINAS THIS AFTERNOON WILL SLIDE
EASTWARD OVERNIGHT AS THE UPPER FLOW BRIEFLY BECOMES MORE ZONAL
AHEAD OF THE NEXT SHORTWAVE TROUGH. COOLEST TEMPERATURES (LOWER
40S) WILL BE OVER THE EASTERN BIG BEND OVERNIGHT...CLOSER TO THE
SURFACE HIGH. FARTHER WEST...WEAK RETURN FLOW WILL BEGIN TO
DEVELOP...KEEPING LOW TEMPS IN THE UPPER 40S AND LOWER 50S.


.SHORT TERM [MONDAY THROUGH TUESDAY NIGHT]...

AS A SURFACE COLD FRONT AND DIGGING SHORTWAVE REACH AN AREA OF
DEEPER MOISTURE TONIGHT OVER THE ARKLATEX, CONVECTION SHOULD
DEVELOP JUST HEAD OF THE SURFACE FRONT. THIS BAND OF CONVECTION
SHOULD BE MAINTAINED AS IT TRANSLATES EAST AND SOUTHEAST INTO THE
DAYTIME HOURS ON MONDAY IN A REGION OF ENHANCED LIFT WHERE THE
FOLLOWING FEATURES WILL BE SUPERIMPOSED: LOW-LEVEL COLD FRONT,
DIGGING SHORTWAVE, LEFT EXIT REGION OF A 100KT UPPER LEVEL JET
STREAK. MODELS BRING CONVECTION INTO OUR FORECAST AREA PRIMARILY
IN THE AFTERNOON HOURS.

OVER THE WESTERN HALF OF OUR FORECAST AREA (ROUGHLY ALONG AND
WEST OF A TLH-ABY LINE), MODERATE INSTABILITY AND WIND SHEAR MAY
SUFFICIENTLY OVERLAP TO YIELD A SMALL CHANCE OF SOME SEVERE
STORMS. IN THOSE AFOREMENTIONED AREAS, THE 15Z SREF MEAN INCREASES
AFTERNOON SBCAPE TO NEAR 1000 J/KG WITH AROUND 30 KNOTS OF 0-6KM
SHEAR. THERE IS ALSO GOOD AGREEMENT ON MODEL FORECAST SOUNDINGS OF
STEEP MID-LEVEL LAPSE RATES AROUND 7 C/KM AND RELATIVELY LOW WET-
BULB ZERO HEIGHTS (7000 TO 9000 FT AGL, DEPENDING ON MOISTURE
PROFILES). THE SOMEWHAT FAVORABLE OVERLAP OF INSTABILITY AND SHEAR
SUGGESTS A CHANCE OF A FEW SEVERE STORMS, WHILE THE LAPSE RATES
AND WBZ HEIGHTS SUGGEST THAT HAIL MAY BE THE PRIMARY RISK WITH
GUSTY WINDS SECONDARY. IF SBCAPE EXCEEDS 1000 J/KG, AS INDICATED
BY SEVERAL HI-RES WRF MODELS AND THE 12Z NAM, THEN THE CHANCES OF
LARGE HAIL WILL INCREASE. THOSE PARTICULAR MODEL FORECAST
SOUNDINGS INDICATE A SIG HAIL PARAMETER AROUND 1.0 TO 1.2, WHICH
IS IN A FAVORABLE RANGE FOR LARGE HAIL. WE HAVE ADDED SOME WIND
AND HAIL WORDING TO THE FORECAST.

CONVECTION SHOULD DIMINISH AFTER SUNSET...BUT THE FRONT SHOULD
STALL AROUND THE REGION INTO TUESDAY WHICH SHOULD SET UP ANOTHER
CHANCE FOR SHOWERS AND STORMS. THERE IS A LOT OF VARIETY IN MODEL
FORECASTS FOR THE CONVECTIVE ENVIRONMENT ON TUESDAY, SO IT IS A
LITTLE TOUGHER TO EVALUATE POSSIBLE STORM INTENSITY. HOWEVER,
THERE IS A REASONABLE CHANCE OF A SIMILAR ENVIRONMENT AS IS
EXPECTED ON MONDAY, SO A FEW STRONG STORMS CAN`T BE RULED OUT.
POPS BOTH DAYS WILL BE IN THE CHANCE RANGE (30-50%). TEMPERATURES
SHOULD BE SLIGHTLY ABOVE NORMAL.


.LONG TERM [WEDNESDAY THROUGH SUNDAY]...

AFTER A LOW-AMPLITUDE SHORTWAVE PUSHES THROUGH THE AREA ON
WEDNESDAY, BRINGING ADDITIONAL RAIN CHANCES, A CORRESPONDING LOW
AMPLITUDE RIDGE WILL BUILD IN BRINGING A BRIEF PERIOD OF LOWER
RAIN CHANCES AND HIGHER TEMPERATURES FROM THURSDAY INTO FRIDAY.
HIGHS MAY REACH INTO THE MID-80S. A COLD FRONT SHOULD SWEEP
THROUGH THE FORECAST AREA ON SATURDAY, BRINGING SLIGHTLY COOLER
WEATHER AND ANOTHER CHANCE FOR RAIN.

&&

.AVIATION...

[THROUGH 18Z MONDAY] VFR CONDITIONS WILL PREVAIL THROUGHOUT THE
TAF PERIOD WITH THE EXCEPTION OF MVFR CIGS AT DHN MONDAY MORNING
POSSIBLY INTO THE AFTERNOON HOURS. WINDS WILL BECOME MORE
SOUTHERLY THIS AFTERNOON...THEN SOUTHWESTERLY IN THE MORNING AS A
COLD FRONT APPROACHES.

&&

.MARINE...

QUIESCENT MARINE WEATHER CONDITIONS WILL CONTINUE THROUGH FRIDAY
WITH WINDS BELOW 15 KNOTS AND SEAS 2 FEET OR LESS. WINDS SHOULD
INCREASE BEHIND A COLD FRONT ON SATURDAY, WITH SCEC OR EVEN
ADVISORY LEVEL CONDITIONS POSSIBLE.

&&

.FIRE WEATHER...

DESPITE THE COOL AFTERNOON TEMPERATURES...THE AIR MASS IS CLEARLY
DRY ENOUGH TO VERIFY THE RED FLAG WARNING FOR TODAY. WITH
FORECAST ERC VALUES OF 37 FOR BOTH LEON AND WAKULLA COUNTIES...AND
VERY LONG DURATIONS OF SUB 28 PERCENT RH. BY MONDAY AND THROUGH AT
LEAST THE MIDDLE OF NEXT WEEK...LOW LEVEL MOISTURE AND RAIN
CHANCES WILL BE GRADUALLY ON THE INCREASE.

&&

.HYDROLOGY...

AVERAGE RAINFALL AMOUNTS OVER THE NEXT WEEK SHOULD BE LESS THAN AN
INCH ACROSS THE AREA. SOME LOCALIZED HIGHER AMOUNTS ARE POSSIBLE
OVER THE NEXT COUPLE DAYS WITH STRONGER THUNDERSTORMS, BUT THAT
SHOULD NOT CONTRIBUTE TO ANY RIVER FLOODING RISK. RIVER LEVELS
SHOULD REMAIN FAIRLY STABLE BELOW FLOOD STAGE ACROSS THE AREA.

&&

.PRELIMINARY POINT TEMPS/POPS...

TALLAHASSEE   43  78  58  81  61 /  10  30  30  30  20
PANAMA CITY   55  74  64  75  66 /  10  30  30  20  10
DOTHAN        49  78  55  78  60 /  10  50  20  40  30
ALBANY        46  76  53  79  58 /  10  50  20  30  20
VALDOSTA      43  77  54  79  59 /  10  30  30  20  20
CROSS CITY    40  76  57  81  61 /   0   0  20  20  10
APALACHICOLA  51  75  63  77  66 /   0  20  20  20  10

&&

.TAE WATCHES/WARNINGS/ADVISORIES...

FL...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR COASTAL WAKULLA-
     INLAND WAKULLA-LEON.

GA...NONE.
AL...NONE.
GM...NONE.

&&

$$

NEAR TERM...CAMP
SHORT TERM...LAMERS
LONG TERM...LAMERS
AVIATION...MCDERMOTT
MARINE...LAMERS
FIRE WEATHER...WOOL
HYDROLOGY...LAMERS



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