Area Forecast Discussion
Issued by NWS Jacksonville, FL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KJAX 300757
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
310 AM EDT SUN AUG 30 2015

...LOCALIZED FLOODING EXPECTED THIS WEEK...

.NEAR TERM /TODAY AND TONIGHT/...

EARLY THIS MORNING...STRONG MID LEVEL SHORTWAVE IMPULSE/VORT MAX
RIDING UP THE NE FL COAST IS ASSOCD WITH LIGHT/MODERATE RAIN
SHIELD ALONG THE I-95 CORRIDOR FROM JAX NORTHWARD ACROSS COASTAL
SE GA AND EXPECT THIS FEATURE TO SLOWLY PUSH NORTH OF BRUNSWICK BY
SUNRISE WITH A SHARP DOWNWARD TREND IN PCPN COVERAGE OVER LAND
AREAS WITH LINGERING SHOWERS AND STORMS OVER THE COASTAL WATERS.
GUSTY WINDS OF 30 TO 40 MPH HAVE BEEN REPORTED WITH THIS FEATURE
ALL THE WAY UP THE COAST FROM FLAGLER COUNTY AROUND 11 PM TO
COASTAL SE GA AROUND 2-3 AM TIME FRAME.

TODAY...CUT OFF UPPER LOW NEAR PENSACOLA IN WRN FL PANHANDLE
EXPECTED TO TRACK NORTHEAST TOWARDS ATLANTA THROUGH THE DAY AND
THIS WILL KEEP A VERY MOIST SOUTHERLY FLOW ACROSS THE REGION. THE
MORNING HOURS MAY BE A BIT DRIER THAN MODELS DEPICTING WITH SOME
SUBSIDENCE PUSHING IN BEHIND THE DEPARTING SHORTWAVE BUT ANY
LIMITED HEATING TODAY INTO THE MIDDLE/UPPER 80S WILL QUICKLY
TRIGGER SHOWERS AND EMBEDDED STORMS WITH LOCALLY HEAVY RAINFALL
DURING THE AFTERNOON WITH HIGHEST RAINFALL CHANCES ALONG THE I-95
CORRIDOR AND ATLC COASTAL WATERS WITH POPS IN THE 80-90% RANGE AND
LESSER POPS FURTHER INLD IN THE 50-70% RANGE. LOCALLY HEAVY
RAINFALL REMAINS THE MAIN IMPACT TODAY WHILE SOME STRONG STORMS
WITH GUSTY WINDS AND FREQUENT LIGHTNING CAN BE EXPECTED ESPECIALLY
FURTHER INLAND ACRS INLD SE GA AND THE SUWANNEE RIVER VALLEY WHERE
MORE DIURNAL HEATING IS EXPECTED AND MAX TEMPS MAY REACH CLOSE TO
90 DEGREES...WHILE THE ATLC COASTAL COUNTIES WILL SEE OCCASIONAL
SHOWERS AND EMBEDDED STORMS WITH HIGHS ONLY IN THE MIDDLE 80S.

TONIGHT...NUMEROUS TO WIDESPREAD SHOWERS WITH LOCALLY HEAVY
RAINFALL WILL BE ONGOING DURING THE EVENING HOURS...THEN WILL FADE
SLOWLY TOWARDS MIDNIGHT WITH LOSS OF HEATING...ALTHOUGH SOUTHEAST
FLOW NEAR THE SURFACE WILL KEEP BEST CHANCE OF SHOWERS CONTINUING
ALONG THE I-95 CORRIDOR/COASTAL COUNTIES AND COASTAL WATERS
THROUGH THE NIGHT. LOWS GENERALLY IN THE 70S AGAIN. 24 HOUR
RAINFALL TOTALS THROUGH TONIGHT WILL GENERALLY BE CLOSE TO AN
INCH WITH LOCALIZED TOTALS CLOSER TO 2-3 INCHES IN STRONGER STORMS
AND TRAINING OF CELLS THAT OCCUR DURING THE AFTERNOON AND EVENING
HOURS.

.SHORT TERM /MONDAY AND TUESDAY/...

HEAVY RAINFALL WITH A THREAT OF LOCALIZED FLOODING WILL CONTINUE ON
MONDAY AND TUESDAY. A PLUME OF DEEP TROPICAL MOISTURE WILL FEED
NORTH INTO THE AREA AND MAINTAIN A WET PATTERN. WE HAVE CONTINUED TO
FAVOR THE SOLUTION OF THE GFS AND EUROPEAN MODELS WHICH SHOW THE
REMNANTS OF ERIKA IN THE EASTERN GULF OF MEXICO AS MAINLY AN OPEN
WAVE WITH AN INVERTED TROUGH AXIS EXTENDING NORTH INTO OUR AREA.
DEEP MOIST SOUTHERLY FLOW WILL BRING AN INCREASE IN PWATS TO ABOVE
2.25 INCHES WITH BUFR SOUNDINGS INDICATING A SATURATED COLUMN OF AIR
BOTH DAYS. THIS WILL TRANSLATE TO MULTI-LAYERED CLOUD COVERAGE WHICH
WILL REDUCE THE AMOUNT OF POTENTIAL INSTABILITY. THUS WIDESPREAD NON
STOP HEAVY RAINFALL FOR AN EXTENDED PERIOD OF TIME IS NOT
ANTICIPATED.

TOTAL RAINFALL AMOUNTS THROUGH TUESDAY WILL LIKELY AVERAGE AROUND 2
TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS EXPECTED. THIS WILL SUPPORT
MORE IN THE WAY OF A LOCALIZED FLOOD THREAT AS OPPOSED TO A
WIDESPREAD SIGNIFICANT FLOOD EVENT. THUS WE WILL HOLD OFF ON ISSUING
ANY FLOOD WATCHES AT THIS TIME. INCREASED COASTAL CONVERGENCE SHOULD
SUPPORT THE HEAVIEST RAIN ALONG THE ATLANTIC COAST THEN SHIFTING
INLAND EACH DAY. COASTAL CONVECTION WILL CONTINUE DURING THE
OVERNIGHT HOURS WITH THE HEAVIEST RAIN EXPECTED TO REMAIN JUST
OFFSHORE ALTHOUGH AT LEAST SOME OVERNIGHT RAIN IS EXPECTED AT THE
COAST.

IT SHOULD BE NOTED THAT THE NAM CONTINUES TO WRAP UP THE REMNANTS OF
ERIKA IN TO A WEAK BUT TIGHTLY CLOSED CIRCULATION DIRECTLY OVER OUR
AREA ON MONDAY. FOR NOW WE ARE DISCOUNTING THIS SOLUTION...BUT THIS
IS THE TYPE OF SOLUTION WE WOULD NEED TO SUPPORT A BETTER CHANCE FOR
ORGANIZED FLOODING IN OUR AREA. WE WILL CONTINUE TO MONITOR THIS
SITUATION AND SHOULD HAVE A MUCH BETTER HANDLE ON IT LATER TODAY
INTO TONIGHT.

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...

BROAD SURFACE TROUGH IS EXPECTED TO LINGER OVER THE AREA THROUGH THE
END OF THE WEEK. THE MID LEVEL RIDGE OVER THE REGION SHOULD BEGIN TO
BREAK DOWN BY THE END OF THE WEEK. MOISTURE AND INSTABILITY WILL
REMAIN HIGH ENOUGH TO SUPPORT A DIURNAL PATTERN OF SCATTERED TO
NUMEROUS SHOWERS AND STORMS EACH DAY...WITH A FOCUS ALONG THE QUASI-
STATIONARY SURFACE BOUNDARY AND ALONG THE SEABREEZES. LOCALLY HEAVY
RAINFALL WILL CONTINUE TO BE THE MAIN CONCERN.

&&

.AVIATION...
WIDESPREAD LIGHT RAIN SHIELD IMPACTING ALL TAF SITES EXCEPT KGNV
WITH A MIXTURE OF VFR AND MVFR CIGS/VSBYS. THE RAINFALL SHOULD
TAPER OFF TOWARDS SUNRISE WITH MULTI-LAYER MVFR/VFR CLOUDS AND
VCSH SHOULD HOLD IN MOST OF THE TAF SETS DURING THE MORNING HOURS
EXCEPT FOR KSSI WHERE SHOWERS WILL CONTINUE THROUGH THE MORNING
HOURS. FOR THE AFTERNOON...WITH SO MUCH UNCERTAINTY IN WHERE
CONVECTION WILL SET UP...HAVE KEPT VCTS AT ALL TAF SETS.

&&

.MARINE...
ONSHORE FLOW INCREASES CLOSE TO 15 TO 20 KNOTS LATER TODAY AND
EXPECT TO CONTINUE SMALL CRAFT EXERCISE CAUTION HEADLINES AS SEAS
BUILD INTO THE 4-6 FT RANGE AND WILL CONTINUE INTO EARLY THIS
WEEK. FLOW WILL BECOME SOUTHERLY BY TUE/WED TIME FRAME AND
DECREASE IN SPEEDS WITH SEAS SLOWLY SUBSIDING.

RIP CURRENTS: MODERATE RISK OF RIPS CONTINUES IN THE ONSHORE FLOW
WITH BREAKER REPORTS IN THE 2-4 FT RANGE.

TIDES/COASTAL FLOODING: SATURDAY`S FULL MOON HIGH TIDAL CYCLES
ALONG THE COAST AND LOWER ST JOHNS RIVER BASIN ALL REMAINED JUST
BELOW COASTAL FLOOD LEVELS AND EXPECT SIMILAR CONDS ON TODAYS HIGH
TIDAL CYCLES...SO NO STATEMENTS OR ADVISORIES ARE EXPECTED.

&&

.HYDROLOGY...
WIDESPREAD 2-4 INCH RAINFALL AMOUNTS EXPECTED THIS WEEK...BUT DUE
TO THE LOCALIZED NATURE OF HEAVIER CONVECTION AT TIMES NO PLANS TO
ISSUE FLOOD WATCH WITH THE MORNING PACKAGE. CONDITIONS ON BLACK
CREEK AND UPPER SANTA FE RIVER BASIN REMAIN ELEVATED BUT MISSED
OUT ON HEAVIEST ACTIVITY ON SATURDAY AND WILL DEPEND ON ANY HEAVY
BANDS THAT SET UP TODAY OR INTO THIS WEEK TO SEE IF STAGES CAN
PUSH SIGNIFICANTLY HIGHER.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  87  72  88  74 /  70  50  60  30
SSI  84  77  86  76 /  80  70  80  60
JAX  87  73  87  75 /  80  60  70  40
SGJ  87  75  87  75 /  90  70  80  50
GNV  88  73  87  73 /  80  50  70  30
OCF  89  73  87  73 /  90  60  80  30

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&

$$

HESS/SHULER


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