FXUS61 KAKQ 041519
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1019 AM EST FRI DEC 4 2009
.SYNOPSIS...
WEAK HIGH PRESSURE SLIDES OVER THE REGION TODAY...WHILE THE NEXT
LOW PRESSURE SYSTEM DEVELOPS OVER THE GULF OF MEXICO...THEN TRACKS
NORTHEAST TO OFF THE CAROLINAS BY SATURDAY AFTERNOON. THE
STORM MOVES QUICKLY AWAY FROM THE COAST SATURDAY NIGHT. HIGH
PRESSURE BUILDS BACK OVER THE REGION FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SC CLOUD DECK OVRSPRDG WRN CNTYS ATTM WITH HIGH/MID LVL CLDS
NOTED ELSEWHERE. HAVE ADJUSTED CLOUD GRIDS TO REFLECT M CLDY SKIES
ACROSS WRN CNTYS. OTW...PT SUNNY SKIES WILL BECOME M CLDY B4 SS.
12Z DATA SPRTS CRNT FCSTD MAX TMPS...GNRLY IN THE L-M50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
SKIES WILL BCM MSTLY CLDY BY EVENING AS COLUMN CONTS TO MOISTEN.
STM SYS QUICKLY SHIFTS TO THE SE COAST LATE TONIGHT...THEN
INTENSIFIES AND MVS NE ALONG THE COAST SAT/SAT NGHT. MSTR SURGES
NWRD INTO THE MID ATLC WHERE PRECIP CHCS ARE INTRODUCED ACROSS SRN
COUNTIES THIS EVENING...WITH THE REST OF THE FA TO FOLLOW
OVERNIGHT. P-TYPE WILL NOT BE A CONCERN TONIGHT AS TEMPS WILL BE
MUCH TOO WARM.
CONFIDENCE IS HIGH THAT WE WILL HAVE ANOTHER WIDESPREAD
PRECIP EVENT...SO HV GONE AHEAD AND BUMPED UP POPS TO CATEGORICAL
EARLY SAT. SAT MORNING PRECIP WILL BE IN THE FORM OF A COLD RAIN
BUT AS STM SYS BEGINS TO PULL AWAY FROM THE AREA, THE THREAT FOR A
WINTRY PRECIP BEGINS ACROSS THE NW TIER...WHERE SUFFICIENT COLUMN
COOLING BEGINS TO TAKE PLACE. MDLS HV GENERALLY STAYED IN LINE
WITH CURRENT FORECAST...THOUGH THE NAM IS BIT MORE DEEPER AND
AMPLIFIED THAN OTHER SOLNS AND IS BELIEVED TO BE TRYING TO CATCH
UP TO OTHER MDL SOLNS. HV TRIED TO SHOW A NW TO SE PROGRESSION OF
RA CHANGING TO -SN SAT AFTN AND EVENING. AGREE WITH PREV FORECAST
THAT A MINOR SLUSHY ACCUM IS POSSIBLE...AT LEAST OVR GRASSY SFCS.
AT THIS POINT HEADLINES ARE NOT NEEDED AND WILL CONTINUE TO
MENTION SNOW CHCS IN THE HWO.
SYS IS QUICK TO MV NE AND FARTHER OUT TO SEA SAT NIGHT. (GFS
ACTUALLY SHOWING A FASTER SOLN WITH 0Z RUN.) THIS WILL RESULT IN
CLEARING FROM W TO E OVERNIGHT SAT AND AN END TO THE MAJORITY OF THE
PRECIP SHORTLY AFTER MIDNIGHT. WL HANG ONTO SLGT CHC (MIXED RN/SN)
POPS NR THE CST. SFC HI PRES BUILDS OVR THE FA ON SUN...BRINGING
DRY/SEASONABLY COOL WX. LO TEMPS SAT NGT IN THE 20S TO M30S. HI
TEMPS SUN FM THE M40S TO NR 50.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MODEL AGREEMENT IN THE EXTENDED RANGE CONTINUES AS THE MODELS
SHOW A FAST FLOW ACROSS THE US WITH MUCH MORE PACIFIC FLOW VERSUS
A MERIDIONAL FLOW. THIS WILL RESULT IN RELATIVELY MILD WEATHER FOR
THIS TIME OF YEAR...BUT WILL SEE SEVERAL SYSTEMS MOVING ACROSS THE
US WITH GULF MOISTURE AVAILABLE.
TO BEGIN THE PERIOD...RIDGING OVER THE SOUTHEASTERN US WILL BE
BUILDING NWD INTO THE MID ATLANTIC STATES...ALLOW FOR SW FLOW
ALOFT. INTIALLY THIS WILL RESULT IN HIGH LEVEL MOISTURE WITH A
SHORTWAVE TROUGH LIFTING NE OF THE AREA ON MONDAY. SO FOR NOW HAVE
KEPT THE REGION DRY SUNDAY NIGHT INTO TUESDAY...BUT HAVE ALLOWED
FOR MORE SKY COVER. THIS CLOUD COVER SHOULD LIMIT THE DAY TIME
HEATING SOME ...BUT HIGHS IN THE LOW TO MID 50S IS STILL
REASONABLE. A WEAK FRONT DOES TRY AND CROSS THE MOUNTAINS MONDAY
AFTERNOON...BUT LOOKS LIKE TI WILL WEAKEN AND NOT REACH THE AREA
SO HAVE NOT INCLUDING POPS WITH IT.
THE SW FLOW WILL CONTINUE TUESDAY INTO WEDNESDAY...ALLOWING THE
MOISTURE TO BUILD AND FOR OVERRUNNING RAIN ON TUESDAY NIGHT INTO
WEDNESDAY. THE GFS AND ECMWF BOTH SHOW A STRONG TROUGH SWEEPING
EAST WITH THIS SYSTEM ON WEDNESDAY. THE GFS IS MORE AMPLIFIED AND
AS A RESULT PUSHES MUCH WARMER AIR INTO THE REGION WEDNESDAY. THE
ECMWF DOES NOT AMPLIFY THE WAVE UNTIL AFTER IT REACHES NEW ENGLAND
SO THE WARMING IS NOT A GREAT. FOR NOW HAVE JUST INCREASED POPS TO
HIGH CHANCE AND HELD TEMPERATURES DOWN CLOSER TO THE ECMWF/HPC
NUMBERS...BUT IF THE PATTERN DOES AMPLIFY...IT COULD EASILY ALLOW
TEMPERATURES TO PUSH INTO THE 60S PRIOR TO THE COLD FRONTAL PASSAGE.
BY THURSDAY...THE LOW IS DEEPENING OFF THE NEW ENGLAND COAST WITH
A COLD NW FLOW ACROSS THE MID ATLANTIC STATES. THIS SHOULD ALLOW
FOR CLEARING CONDITIONS WITH COOL...BUT NOT COLD TEMPERATURES.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
TRANQUIL CONDITIONS TODAY...WINDS HAVE DIMINISHED AND VFR CONDITIONS
PREVAIL AS VARIABLE CLOUDINESS HAS OVERSPREAD THE REGION W/ ANY CIGS
BEING 5-6K FT OR HIGHER. OVERALL...EXPECT AN INCREASE IN MID/HIGH
CLOUDS TODAY WITH A GENERAL N TO NE FLOW AROUND 10 KT OR LESS.
A DEVELOPING COASTAL SYSTEM LOOKS TO IMPACT THE REGION ON
SATURDAY...EXPECT RAIN AND TO BEGIN SOMETIME BETWEEN 06Z-12Z SAT
(EARLIEST SOUTH AT ECG/ORF...AND LATEST AT SBY). BREEZY NNE FLOW CAN
BE EXPECTED ALONG THE COAST SAT WITH GUSTS TO AT LEAST 25 KT AT ORF.
ALL SITES SHOULD SEE CIGS LOWER TO 2K FT OR LOWER AFTER 12-15Z.
PRECIP TYPE MAY BECOME AN ISSUE AS RAIN MIXES WITH AND/OR CHANGES
TO SNOW LATER IN THE AFTN/AFTER 20Z FOR RIC...AND FOR ORF/PHF/SBY
AFTER 00Z/SUNDAY. CLEARING BY SUNDAY MORNING BETWEEN 06-12Z.
&&
.MARINE...
CURRENTLY HAVE SEAS STILL AROUND 5 FT FOR THE SOUTHERN COASTAL
WATERS BUT THEY HAVE BEEN TRENDING DOWN AND WILL END THE HEADLINE
OVER THE NEXT FEW HRS...WITH NO NEAR-TERM HEADLINES IN EFFECT FOR
THE REMAINDER OF THE MARINE AREA. ANTICIPATE A FAIRLY QUIET DAY
TODAY...WINDS 10-15 KT THROUGH EARLY AFTN...BECOMING NE AND
DIMINISHING TO 5-10 KT BY AFTN.
IT WILL BE A BRIEF RESPITE...AS A DEVELOPING COASTAL LOW STRENGTHENS
OFF THE SC/NC COAST LATER TONIGHT THROUGH SAT. HAVE RAISED THE NEXT
SET OF HEADLINES...SMALL CRAFT ADVISORIES FOR ALL ZONES AFTER
06Z/SAT FOR SOUTHERN WATERS...AND 11Z FARTHER NORTH. UNLIKE THE LAST
EVENT...THIS WILL FEATURE A NORTHERLY FLOW AND MUCH BETTER MIXING SO
EVEN WITH A MORE MODEST SFC PRESSURE GRADIENT...THERE IS STILL THE
POSSIBILITY FOR GALES (ALTHOUGH FOR NOW HAVE DECIDED TO CAP WIND
GUSTS AT 33KT AND FCST A SUSTAINED 25-30 KT). BY SAT NIGHT...WINDS
TURN MORE TO THE NNW SO SEAS/TIDAL ANOMALIES DO NOT HAVE A LOT OF
TIME TO BUILD (ALTHOUGH SEAS OF AT LEAST 7-9 FT ARE STILL EXPECTED).
FOLLOWED CLOSER TO NAM FOR WINDS SAT NIGHT/EARLY SUNDAY AS DEEP CAA
SHOULD CONTINUE TO BRING 25KT OR MORE TO THE RELATIVELY WARM WATERS
(GFS APPEARS TOO FAST AT DIMINISHING THE WINDS).
HIGH PRESSURE BUILDS IN LATER SUNDAY/MONDAY ALLOWING SEAS/WINDS TO
SUBSIDE.
&&
.HYDROLOGY...
DUE TO RECENT HEAVY RAINFALL OVER THE REGION...FLOOD WARNINGS
CONTINUE FOR THE MEHERRIN RIVER AT LAWRENCEVILLE AND THE NOTTOWAY
RIVER NEAR STONY CREEK. SEE LATEST WBCFLSAKQ FOR MORE INFO.
&&
.EQUIPMENT...
THE DATA FEED FOR STONY CREEK RIVER STAGE ON THE WBCRR2AKQ
PRODUCT IS INACCURATE AND WILL BE CORRECTED AS SOON AS POSSIBLE
(BUT MAY TAKE TILL SOMETIME ON FRIDAY TO BE CORRECTED). PLEASE
REFER TO HTTP:/NEWWEB.ERH.NOAA.GOV/AHPS2/INDEX.PHP?WF0=AKQ
AND CLICK ON STONY CREEK ICON ON THE MAP FOR THE LATEST RIVER
STAGE. WE APOLOGIZE FOR ANY INCONVENIENCE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ632-633-656-658.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630-631-650-652-654.
&&
$$
SYNOPSIS...SMF
NEAR TERM...MPR/SMF
SHORT TERM...SMF
LONG TERM...ESS
AVIATION...LKB
MARINE...LKB
HYDROLOGY...
EQUIPMENT...
