Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

153
FXUS62 KTAE 110814
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
414 AM EDT SAT APR 11 2015

.NEAR TERM [THROUGH TODAY]...

AS OF 08 UTC, THE SURFACE WEATHER PATTERN ACROSS THE REGION WAS
SOMEWHAT MUDDLED DUE TO MESOSCALE PRESSURE FLUCTUATIONS FROM EARLIER
CONVECTIVE ACTIVITY. THE SYNOPTIC COLD FRONT APPEARS TO BE SITUATED
FROM NEAR CHARLOTTE, TO ATLANTA, TO MERIDIAN MS, BASED ON SURFACE
TEMPERATURE, THETAE, AND 3HR PRESSURE CHANGES. MOST OF THE LATEST
MODEL RUNS ONLY ADVANCE THIS FRONT TO NEAR THE NORTHERN BORDER OF
OUR FORECAST AREA BY LATE THIS AFTERNOON. DESPITE THAT, MANY OF
THOSE MODELS INITIATE CONVECTION BY MID-LATE MORNING FROM THE
CENTRAL FLORIDA PANHANDLE INTO FAR SOUTH-CENTRAL GEORGIA - WELL
AHEAD OF THE SYNOPTIC FRONT. THIS WOULD LIKELY BE DUE TO THE
COMBINATION OF LINGERING CONVECTIVE OUTFLOW BOUNDARIES (CONVERGENCE
AND MINIMUM IN PRESSURE NOTED AT 08Z FROM PANAMA CITY, TO QUINCY, TO
MOULTRIE) AND A RIBBON OF GREATER INSTABILITY DUE TO HIGHER BOUNDARY
LAYER MIXING RATIOS. THE ONE OUTLIER IS THE 00Z NAM, WHICH FOCUSES
CONVERGENCE FURTHER NORTH ALONG THE SYNOPTIC COLD FRONT AND THUS
KEEPS CONVECTION MORE ISOLATED ACROSS OUR AREA TODAY. HOWEVER, THE
00Z GFS, 00Z ECMWF, AND MAJORITY OF HI-RES GUIDANCE IS IN AGREEMENT
WITH FOCUSING CONVECTION IN OUR FLORIDA ZONES AND FAR SOUTH CENTRAL
GEORGIA, AND THAT IS HOW WE STRUCTURED THE FORECAST. SOME OF THE HI-
RES GUIDANCE INDICATES VERY HEAVY, BUT LOCALIZED, RAIN RATES ON THE
ORDER OF 2-3"/HR IN SOME SPOTS. WITH SLOW BACK-BUILDING STORM MOTION
VECTORS AND PWATS NEAR THE 95TH TO 99TH PERCENTILE FOR THIS TIME OF
YEAR, THAT IS NOT OUT OF THE QUESTION. WE ADDED SOME HEAVY RAIN
WORDING TO THE FORECAST IN THE AREAS WITH HIGHEST POPS.


.SHORT TERM [TONIGHT THROUGH MONDAY]...

TONIGHT, A BROAD UPPER LEVEL RIDGE CENTERED OVER THE MISSISSIPPI
VALLEY WILL BE SANDWICHED BETWEEN A TROUGH OVER THE NORTHEAST,
AND ANOTHER OFF THE SOUTHWEST COAST OF THE U.S. AT THE SURFACE,
HIGH PRESSURE WILL COVER THE EASTERN CONUS WITH A FRONTAL BOUNDARY
DRAPED ESSENTIALLY ZONAL ACROSS THE LOWER SOUTHEAST. THROUGH
MONDAY, THE ENTIRE PATTERN WILL SHIFT EAST, WITH THE SOUTHWEST
TROUGH CUTTING OFF OVER WEST TEXAS, AND A NORTHERN STREAM TROUGH
AXIS MOVING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS. AT
THE SURFACE, HIGH PRESSURE WILL FINALLY BE LOSING ITS HOLD AS
BROAD TROUGHING MOVES THROUGH THE MISSISSIPPI VALLEY.

EXPECT THE SHORT TERM PERIOD TO BE RATHER WET, WITH A NOTICEABLE
DIURNAL TREND ON SUNDAY AND MORE STEADY WIDESPREAD RAIN MOVING IN
SUNDAY NIGHT THROUGH MONDAY. CONVECTION ON SUNDAY WILL MOSTLY BE
FORCED ALONG THE DECAYING FRONTAL BOUNDARY, WITH SOME SORT OF WEAK
SEABREEZE INFLUENCE POSSIBLE. SUNDAY NIGHT THROUGH MONDAY, FLOW
WILL VEER SOUTHERLY ON THE BACKSIDE OF THE DEPARTING RIDGE SETTING
UP A LARGE AREA OF ISENTROPIC RAIN IN THE WAA REGIME. AT THE SAME
TIME A SOUTHERN STREAM ANOMALY WILL BE MOVING OUT OF THE SOUTHERN
PLAINS, THROUGH THE MISSISSIPPI VALLEY, AND INTO THE DEEP SOUTH.
THIS WILL INCREASE THE COVERAGE AND INTENSITY OF THE ALREADY
FORECAST WIDESPREAD RAIN. EXPECT ONLY ISOLATED THUNDERSTORMS
THROUGH THE PERIOD. FROM SUNDAY THROUGH MONDAY, EXPECT WIDESPREAD
AVERAGE RAINFALL AMOUNTS AROUND 2 INCHES, HIGHEST OVER SOUTHEAST
ALABAMA AND THE FLORIDA PANHANDLE.


.LONG TERM [MONDAY NIGHT THROUGH SATURDAY]...

THE EXTENDED RANGE FORECAST REMAINS WET, WITH A PROLONGED SOUTHERN
STREAM CONNECTION TRANSPORTING BOTH ANOMALOUSLY HIGH PWATS INTO
THE SOUTHEAST, AND AT TIMES SOME RATHER STEEP LAPSE RATES FROM THE
MEXICAN PLATEAU REGION. SEVERAL SOUTHERN STREAM ANOMALIES WILL
COMBINE WITH THE AFTERNOON SEABREEZES EACH DAY, AND POSSIBLY EVEN
A BACKDOOR FRONT ON WEDNESDAY, TO FORCE A RATHER WIDESPREAD
COVERAGE OF STORMS. THE POTENTIAL FOR SEVERE WEATHER EXISTS AS
WELL AS THE AFOREMENTIONED LAPSE RATES THE POTENTIAL FOR DAMAGING
WINDS AND HAIL IN THE MORE ISOLATED STRONGEST STORMS. OVERALL,
POPS WILL BE ABOVE AVERAGE, WITH TEMPERATURES NEAR AVERAGE.

&&

.AVIATION...
[THROUGH 06Z SUNDAY]

INTERMITTENT MID-HIGH CLOUD LAYERS ARE CAUSING LOW CLOUDS TO
FLUCTUATE ACROSS THE REGION EARLY THIS MORNING. THEREFORE, MOST
TERMINALS SHOULD SEE A VARIETY OF CONDITIONS THROUGH MID-MORNING,
WITH CIGS REACHING IFR/LIFR AT TIMES. PREDOMINATELY VFR OR MVFR
CIGS ARE EXPECTED DURING THE LATE MORNING AND AFTERNOON HOURS AS
SHOWERS AND STORMS REDEVELOP. THUNDERSTORMS WILL BE MOST LIKELY AT
TLH, AND THEN ECP AND VLD. SOME STORMS COULD PRODUCE HEAVY
RAINFALL AND REDUCE VIS TEMPORARILY INTO THE IFR RANGE.

&&

.MARINE...

IN GENERAL, RELATIVELY LIGHT WINDS AND LOW SEAS WILL PREVAIL FOR
THE NEXT SEVERAL DAYS. THE MOST NOTABLE EXCEPTION WILL BE SUNDAY
NIGHT INTO MONDAY WHEN A NOCTURNAL EASTERLY SURGE COULD BRING
CAUTIONARY LEVEL WINDS TO THE NORTHEAST GULF.

&&

.FIRE WEATHER...

A MOIST AND UNSETTLED WEATHER PATTERN WILL PERSIST THROUGH THE WEEK
WITH MINIMUM RH VALUES EACH AFTERNOON REMAINING ABOVE 60 PERCENT.
THERE SHOULD BE A CHANCE OF RAIN EACH DAY. ALTHOUGH SHOWERS AND
STORMS SHOULD GENERALLY BE SCATTERED, AVERAGE RAINFALL AMOUNTS
SHOULD EXCEED ONE INCH BY LATER IN THE WEEK. SO WHILE A WETTING RAIN
MAY NOT BE LIKELY EACH DAY, MANY LOCATIONS SHOULD EXPERIENCE A
WETTING RAIN SOMETIME IN THE NEXT FEW DAYS.

&&

.HYDROLOGY...

WE`RE TRANSITIONING INTO A MUCH MORE WET PATTERN THAT RECENT DAYS,
WITH WIDESPREAD RAINS EXPECTED SUNDAY NIGHT THROUGH MONDAY NIGHT.
IN THE SHORT-TERM, THE 1 TO 3 INCHES EXPECTED OVER THE NEXT THREE
DAYS WON`T HAVE MUCH OF AN IMPACT ON AREA RIVERS. HOWEVER, OVER
THE COURSE OF THE NEXT 5 TO 7 DAYS, EXPECT AVERAGE RAINFALL
AMOUNTS ON THE ORDER OF 3 TO 5 INCHES (HIGHEST ACROSS THE FLORIDA
PANHANDLE AND ALABAMA). THESE AMOUNTS MAY FORCE SOME RIVERS INTO
ACTION OR EVEN MINOR FLOOD STAGE BY THE END OF NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...

TALLAHASSEE   81  66  78  67  79 /  60  30  70  40  60
PANAMA CITY   77  68  78  70  75 /  60  30  60  50  60
DOTHAN        79  64  77  64  75 /  30  10  60  50  80
ALBANY        79  62  77  64  76 /  40  10  50  40  70
VALDOSTA      81  65  78  66  81 /  50  30  60  30  70
CROSS CITY    83  66  83  67  83 /  20  20  60  30  60
APALACHICOLA  77  69  78  70  76 /  50  20  50  40  50

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&

$$

NEAR TERM...LAMERS
SHORT TERM...HARRIGAN
LONG TERM...HARRIGAN
AVIATION...LAMERS
MARINE...HARRIGAN
FIRE WEATHER...LAMERS
HYDROLOGY...HARRIGAN



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.