Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 231950
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
350 PM EDT THU APR 23 2015

.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL CONTINUE MOVING EAST FROM THE GREAT
LAKES TOWARD NEW ENGLAND THROUGH THIS WEEKEND. MEANWHILE SURFACE
LOW PRESSURE WILL TRACK FROM THE CENTRAL PLAINS...EMERGING OFF THE
CAROLINA COAST SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
ANOTHER BREEZY DAY ACROSS THE MID-ATLC. YESTERDAY`S COLD FRONT
BROUGHT ABOUT ANOTHER MULTI-DAY PERIOD OF WELL-BELOW AVG CONDS THAT
WILL LARGELY LINGER WELL INTO NEXT WEEK. TODAY IS THE SECOND DAY OF
DAILY UPPER WAVE PASSAGES INTO THE COMING WEEKEND...W/ DRIER AND
COOLER AIR BEING THE MAIN WX STORY. TEMPS ARE HAVING TROUBLE GETTING
INTO THE MID-50S AND MOST LOCALES WON`T REACH THE 60F MARK BY THE
END OF PEAK HEATING THIS AFTN. BREEZY WNW WINDS ARE EFFICIENTLY
PREVENTING DEWPOINTS FROM CLIMBING ANY HIGHER THAN THE U20S...FAIRLY
DRY FOR THIS TIME OF YEAR. THIS SETS THE AREA UP FOR CONSECUTIVE NEAR
AND SUB-FREEZING OVERNIGHT PERIODS OVER THE NEXT COUPLE OF
OVERNIGHTS.

SOME GUIDANCE ATTEMPTED TO KEEP A MORE MILD TEMP REGIME OVER SRN
MD...WHILE OTHER LOCAL AND BIAS-CORRECTED VERSIONS COOLED-OFF THE
WRN SECTIONS OF THE AREA A BIT TOO MUCH. THE MAV AND ECM WERE
BLENDED FOR A BETTER DEPICTION OF THE OVERNIGHT LOWS. HAVE
CONVERTED THE FREEZE WATCH INTO A FREEZE WARNING FOR SAME LOCALES
OVERNIGHT...MAINLY FOR POCKETS OF SUB-FREEZING TEMPS TOWARD DAWN
FRI W/ CLOUDS EXITING AND SHELTERED LOCATIONS SEEING CALM/DECOUPLED
WINDS FROM THE NEAR-SFC LAYER.

PLENTY OF CLOUDS SLIDING OVER THE AREA THIS AFTN BUT FRI WILL BE
MAINLY CLEAR. THE UPPER WAVE RESPONSIBLE FOR TODAY`S CLOUD COVER
WILL BE WELL OFF THE COAST...W/ MAINLY AN AREA OF SUBSIDENCE
SWEEPING THRU TMRW AND TAKING THE LOW LEVEL MOISTURE OUT OF THE
AREA. TEMPS WILL BE ON PAR W/ TODAY`S CONDS AS WE START OFF COLDER
BUT W/ LESS CLOUD COVER DURING THE DAY AND A HIGHER SUN
ANGLE...SHOULD BE ABLE TO MAKE UP FOR THE COLDER START.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AREA WL BE AFFECTED BY A NARROW RIDGE OF HIPRES FRI NGT. FLOW ALOFT
WL BE DISORGANIZED THROUGH AS DP H5 LOPRES WL BE EMERGING INTO THE
GULF OF MAINE AND A SECOND STORM SYSTEM WL BE CROSSING THE PLAINS.
MAY GET SOME HIGH CLDS LATE...OTRW WL BE IN A DCPLD ENVIRONMENT WITH
LOW DEWPTS. TEMPS WL BE BELOW NORMAL ONCE AGAIN. FCST REFLECTS A
BLEND.

CLDS WL BE THICKENING AND LOWERING SAT AS WAA OVERSPREADS THE AREA.
THERE SHUD BE ENUF UPGLIDE FOR PCPN...BUT THE ACTIVE SRN STREAM OF
THE UPR JET SUGGESTS THAT PCPN WL STRUGGLE TO MAKE IT TOO FAR NORTH
TOO QUICKLY. ASSOCIATED LOPRES WL BE NEAREST LATE SAT NGT...AND MADE
THAT THE WETTEST PD. NE MD POPS STILL DONT RISE ABV CHC. ON THE
OTHER HAND...CAT POPS FOR A PORTION OF THE PTMC HIGHLANDS. LKLY IN
BTWN. SAT MIDDAY-AFTN WL BE THE PD WHEN PCPN OVERSPREADS AREA... AND
HV OFFERED GRDLY INCRSG POPS.

SUNDAY DOESNT LOOK PRETTY...BUT ITS DISORGANIZED. WL HV SFC LOPRES
EMERGING OFF THE COAST WHILE THE UPR LOW RETROGRADES TO OUR NORTH
AND STARTS TO FILL. THINK IT/LL BE FAIRLY CLOUDY BUT PCPN WL BE
SPOTTY IF ANY. THIS WL KEEP TEMPS ON THE COOLER SIDE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD OVERHEAD FROM THE GREAT LAKES SUNDAY NIGHT
THROUGH TUESDAY...BRINGING MAINLY DRY CONDITIONS ALONG WITH MORE
BELOW NORMAL TEMPERATURES THANKS TO A NORTHERLY FLOW. LOW PRESSURE
WILL PASS BY TO OUR SOUTH DURING THE MIDDLE PORTION OF NEXT
WEEK...BRINGING THE NEXT CHANCE FOR RAIN.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SOLID VFR CONDS THRU THE TAF PERIOD...THOUGH THE MAIN NOTES ARE THE
CONTINUED GUSTY SFC AND BOUNDARY LAYER WINDS. TOP-END GUSTS CONTINUE
TO SHOW IN THE 25-30KT RANGE ACROSS MUCH OF THE AREA AND WILL
GRADUALLY SUBSIDE TOWARD 00Z THIS EVE. A STEADY BREEZE AROUND 5KT
CONTINUES INTO MID-MRNG FRI...THEN ANOTHER INCREASE BACK TOWARD THE
20-30KT RANGE DURING THE MIDDAY HRS. CIGS THIS AFTN ARE LOWEST IN
THE 5-7KT RANGE...MORE DENSE OVER NRN MD AND DISSIPATING OFF CLOSER
TO THE KCHO AREA. MAINLY CLR SKIES FOR FRI AFTN.

SHUD HV VFR FLGT CONDS FOR THE MRNG HRS...BUT CLDS WL THICKEN AND
LOWER DURING THE DAY. MVFR-IFR LATE SAT INTO ELY SUN. LOWER
CONFIDENCE WHAT FLGT CAT WE WL BE IN SUN AFTN...BUT SUSPECT
RESTRICTIONS WL LINGER.

VFR MON-TUE.

&&

.MARINE...
SOLID SCA CONDS WILL LINGER INTO THE EVE HRS...DIMINISHING TO LOWER
END GUSTS AFTER SUNSET. HOWEVER...A NLY SURGE IS EXPECTED TO MAKE
ITS WAY DOWN THE MAIN CHANNELS OF THE MD CHES BAY AND MAY LEAD TO
SOME HIGH-END SCA GUSTS OR A FEW ISOLATED GALE GUSTS. SCA IN EFFECT
FOR THE BAY OVERNIGHT...THEN FOR ALL THE WATERS AGAIN ON FRIDAY W/
ANOTHER DAY OF BREEZY NW WINDS ACROSS THE ENTIRE REGION.

NLY FLOW FRI NGT WL DIMINISH OVNGT. LGT/VRBL FLOW OVER THE WKND.


&&

.FIRE WEATHER...
BREEZY WNW WINDS TODAY AND LOW DEWPOINTS WILL SET PARTS OF THE AREA
UP FOR SOME ENHANCED FIRE WX CONCERNS ON FRIDAY. FUEL MOISTURES WERE
JUST ABOVE THRESHOLD VALUES TODAY. ALSO FAIRLY DENSE CLOUD COVER AND
COOL TEMPS HAVE LIMITED THE THREAT FOR TODAY. HOWEVER...SEVERAL HRS
WORTH OF DRY AND GUSTY WINDS TODAY WILL LIKELY DECREASE FUEL
MOISTURES ENOUGH FOR PORTIONS OF N CNTRL VA/BLUE RIDGE/FOOTHILLS AND
POSSIBLY SRN MD TO BE CLOSE TO RED FLAG CRITERIA FRI AFTN. THE
STRONGEST WINDS IN THE AREA WILL BE ALONG THE HIGHER TERRAIN AND
ACROSS NERN MD...NOT EXACTLY COINCIDENT W/ THE DRIEST FUEL MOISTURES
IN THE AREA.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FREEZE WARNING FROM 2 AM TO 9 AM EDT FRIDAY FOR MDZ003>006-507.
VA...FREEZE WARNING FROM 2 AM TO 9 AM EDT FRIDAY FOR VAZ025>031-507-
     508.
WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT FRIDAY FOR WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT FRIDAY FOR ANZ530>534-
     537>543.
     SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ535-
     536.
     SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT FRIDAY FOR ANZ535-
     536.

&&

$$
SYNOPSIS...HTS
NEAR TERM...GMS/HTS
SHORT TERM...HTS
LONG TERM...CEM/BJL
AVIATION...GMS/HTS
MARINE...GMS/HTS
FIRE WEATHER...GMS


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