FXUS61 KLWX 292015 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 315 PM EST SAT JAN 29 2011 .SYNOPSIS... A SHORT WAVE WILL TRACK EAST FROM PENNSYLVANIA THROUGH THIS EVENING. A RIDGE OF HIGH PRESSURE WILL BUILD TO THE NORTH SUNDAY INTO MONDAY. A STORM SYSTEM WILL TRACK TOWARD THE AREA LATER MONDAY INTO WEDNESDAY. HIGH PRESSURE WILL THEN RETURN FOR THE LATTER PART OF THE WEEK. && .NEAR TERM /TONIGHT/... IN A FLASHBACK - WHAT A DIFFERENCE A HALF-YEAR MAKES. I WAS THINKING AB HOW HOT IT WAS AT THE END OF JUL 2010 SO I DID SOME SEARCHING. JUL 29 - ALL 3 MAJOR AIRPORTS HAD HIGH TEMPS OF 92-94 W/ LOWS OF 73-76. THERE WERE STRONG TSTMS THAT AFTN - IAD GUSTED TO 45 MPH. SIX MONTHS HENCE WL WE BE THINKING ABT THE SNOWS OF THIS PAST WED? BACK TO TDA - SFC ANLYS SHOWS AN ARCTIC BNDRY ACROSS SRN QUEBEC/ONTARIO. CLRG SKIES ONGOING ACROSS THE CENTRAL SHEN VLLY...DENSER CLD CVR CLOSER TO THE PA BRDR. THESE CLDS ARE CAUGHT UP IN A JET RUNNING FM THE UPR MIDWEST TO PA. A SHRT WV IS PROGRESSING THRU THIS FLOW BRINGING SNOW TO PA. S OF THE MASON- DIXON LN HAS HAD A FEW OBS OF LGT SNOW...AND MAY CONT TO DO SO THRU ERLY EVE...BUT NO APPRECIABLE SNOW IS XPCTD. AFTR THAT SKIES XPCTD TO RMN GNRLY CLDY AS THAT UPR LVL FLOW PERSISTS OVR THE MID ATLC RGN. THERE SHOULD BE LTL DIURNAL TEMP VARIATION TNGT - LOWEST TEMPS IN THE HIGHLANDS IN M20S...BUT MAJORITY OF THE CWA WL ONLY FALL TO 25-30. && .SHORT TERM /SUNDAY/... ON SUNDAY THE CD FNT THAT IS IN ASSO W/ THE SHRT WV OVR OH WL BE MOVING THRU THE MID ATLC. BLV THAT SUNDAY MRNG WL STILL SEE A FAIR AMT OF CLD CVR...BUT THEN BRKS WL DVLP DURG THE AFTN. MDLS ARE FCSTG U40S IN THE CENTRAL SHEN VLLY...I'M GOING TO HOLD AT THE M40S. FURTHER N TEMPS WL TOP OUT IN THE U30S AND L40S. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... SUNDAY NIGHT THROUGH TUESDAY...A VERY DEEP LOW OVER NORTHERN QUEBEC WILL DRIFT TOWARD LABRADOR AS A BROAD RIDGE PERSISTS ACROSS THE SOUTHEASTERN CONUS...BRINGING A ZONAL SURFACE RIDGE AXIS ACROSS THE GREAT LAKES AND NORTHERN MID ATLANTIC. AN EASTERLY FLOW/CAD WILL SETUP MONDAY ACROSS THE CENTRAL AND SOUTHERN MID ATLANTIC AS THE CENTER OF THE SURFACE LOW PUSHES EAST TO THE ST LAWRENCE VALLEY. THE COMBINATION OF ONSHORE FLOW AND AN APPROACHING SYSTEM WILL MAKE FOR A VERY COMPLEX PRECIPITATION SCENARIO MONDAY INTO MID WEEK. AS NOTED BY THE PREVIOUS SHIFT...A SHALLOW LAYER OF LOW LEVEL SATURATION EARLY MONDAY WOULD RESULT IN FREEZING DRIZZLE FOR THE BLUE RIDGE AND WEST WITH TEMPS 0 TO -5C GENERALLY NOT COLD ENOUGH FOR ICE CRYSTALS...WENT WITH LOW CHANCES FOR FREEZING RAIN SINCE ACCRETION IS POSSIBLE. AS THE SATURATION DEPTH INCREASES WITH MID LEVEL ISENTROPIC LIFT...CHANCES FOR A WINTRY MIX OF SNOW...SLEET...AND EVENTUALLY FREEZING RAIN IS EXPECTED TO BUILD EAST FROM THE SHENANDOAH VALLEY TO ACROSS THE CWA THROUGH MONDAY NIGHT. MONDAY NIGHT THROUGH TUESDAY NIGHT...A DEEP TROUGH WILL DIG OVER THE SOUTHWESTERN CONUS WITH A MOISTURE PLUME RIDING A BROAD RIDGE ACROSS THE SOUTHEASTERN CONUS TO THE MID ATLANTIC. WITH THE WARMING MID LEVEL SOUTHWESTERLY FLOW...ISENTROPIC FLOW INCREASES...AND THE PRECIP LIKELIHOOD WILL BECOME LIQUID /RAIN AND FREEZING RAIN/ AS SOLID PRECIP /SNOW AND SLEET/ ENDS FROM SOUTHWEST TO NORTHEAST. LIGHT PRECIP RATES ARE EXPECTED THROUGH TUESDAY...BEFORE PICKING UP AND TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. MUCH UNCERTAINTY REMAINS WHETHER RAIN OR FREEZING RAIN WILL FALL FROM THE I-95 CORRIDOR TO THE SHENANDOAH VALLEY TUESDAY AND TUESDAY NIGHT. WITH WARM AIR ALOFT...IT WILL BE UP TO THE SURFACE TEMPS...WHETHER THE WARMER AIR CAN MIX OR RADIATE DOWN. PLEASE STAY TUNED TO THE FORECAST FOR EARLY THROUGH MID NEXT WEEK. THE COLD FRONT ASSOCIATED WITH A DEVELOPING LOW WILL CROSS THE MID ATLANTIC TUESDAY NIGHT THROUGH WEDNESDAY. LIGHT SNOW/RAIN SHOWERS ARE EXPECTED THROUGH THE FRONTAL PASSAGE ON WEDNESDAY...WITH COLD AIR ADVECTION RAPIDLY ENTERING THE REGION WITH MUCH BELOW NORMAL TEMPERATURES TO END THE WEEK. A BRIEF PERIOD OF UPSLOPE SNOW WEST OF THE ALLEGHENY FRONT IS LIKELY LATE WEDNESDAY. && .AVIATION /TONIGHT THROUGH THURSDAY/... WHILE THERE WL BE XTNSV CLD CVR OVR THE MID ATLC RGN TNGT BLV CIGS WL RMN IN THE VFR REALM. BRKS IN THE CLDS SHOULD DVLP DURG THE AFTN AS A CD FNT PUSHES S ACROSS THE RGN. AN ONSHORE FLOW IS EXPECTED TO DEVELOP MONDAY WITH CHANCES FOR A WINTRY MIX OF PRECIPITATION INCREASING ACROSS THE TERMINALS MONDAY THROUGH TUESDAY NIGHT. IFR OR LOWER CIGS ARE EXPECTED MONDAY NIGHT INTO WEDNESDAY. FREEZING RAIN...PARTICULARLY EAST OF I-95 IS POSSIBLE DURING THE PERIOD OF LOW CIGS. STRONG WLY/NWLY FLOW IS EXPECTED AFTER A COLD FRONT ON WEDNESDAY AS COLD AIR SPREADS ACROSS THE AREA. && .MARINE... NO PROBS ON THE WATERS TNGT. A WEAK CD FNT WL PUSH THRU THE WATERS ON SUNDAY BUT WIND GUSTS WL BE CAPPED AT 15 KT. WALKING ACROSS THE MEMORIAL BRIDGE BTWN ARLINGTON AND DC LAST WWK I SAW PLENTY OF ICE IN THE UPR PTMC. MODIS IMGRY SHOWS CHES BAY ABV BALTIMORE AND ITS ERN TRIBUTARIES ARE ALSO ICE CLOGGED. AN ONSHORE FLOW IS EXPECTED TO DEVELOP ACROSS THE CHESAPEAKE BAY REGION MONDAY...MARGINAL SCA CONDS MAY BE MET. STRONG WLY/NWLY FLOW IS EXPECTED...POSSIBLY GALES...AFTER A COLD FRONT ON WEDNESDAY AS COLD AIR SPREADS ACROSS THE AREA. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ PRODUCTS...WOODY!/BAJ  FXUS61 KLWX 131430 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1030 AM EDT Tue Sep 13 2016 .SYNOPSIS... High pressure will drift east from the northern Mid-Atlantic coast rest of today. A mainly dry cold front will cross the area Wednesday night. High pressure returns to the area through Friday before a cold front crosses the area Sunday night. && .NEAR TERM /THROUGH TONIGHT/... Low level SWly flow will bring mid to upper teen 850mb temps today with temperatures a few degrees higher than yesterday...maxima 85 to 90F. Less cloud cover expected tonight with valley/ground fog possible. Warmer with lows 65 to 70 due to a strengthening Sly flow. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... H85 temps rise to 18-20C and sfc winds become westerly ahead of cdfnt moving through the eastern Great Lks and New England states. MOS guidance looks too cool and have used a model trend for MaxT Wed. Expecting temps to reach the mid 90s with record highs likely at DCA and IAD. Cdfnt will be moving through the area during the evening and have kept a slight chance (20% POP) for MD counties along the Mason- Dixon line. High pressure builds Thu through Fri with temperatures at least 10 degs cooler Thu. Low clouds expected to develop behind front Thu and Thu night with some very light precip over the Blue Ridge mountains due to upslope flow. && .LONG TERM /FRIDAY THROUGH MONDAY/... High pressure will be located over New England on Friday, with upper ridging moving overhead. A light onshore wind combined with the low level thermal trough axis passing through may mean Friday is the coolest day of the week (and dry), as highs may stay below 80F for a large portion of the area. The high will move farther east Saturday as a low pressure system moves into the Great Lakes. Am thinking Saturday remains dry, with the best chance for any storms over the western terrain where heights will be lower and there will be a SE upslope component to the low level flow. It's also possible pre-frontal convection from the west approaches during the evening or overnight. Otherwise, increasing temperatures can be expected. For Sunday-Monday, model spread begins to increase significantly in how to handle the approaching cold front, upper level energy, and possible interaction with moisture along the southeast coast. The 00Z ECMWF is flatter with the upper flow and quicker with the front, whereas the 00Z GFS develops a closed low at 500mb, a wave along the front, and a slower passage on Monday. Therefore, the forecast will call for chances of showers and storms through this time period. Temperatures are expected to remain above normal through Monday. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VFR through Wed night. Southerly flow around 10 kt rest of today. Winds shift west Wednesday gusting around 15 kt ahead of a dry cold front that crosses Wednesday night. NWly flow gusts around 20 knots Thursday. MVFR/IFR cigs possible Thu and especially Thu night due to onshore flow behind fropa. There is potential for MVFR clouds due to onshore flow Friday and Saturday mornings, mainly at IAD/MRB/CHO. && .MARINE... South winds 10 to 15 kt through this evening with high pressure offshore. Winds expected to strengthen Wed night with SCA conditions likely Thu through Fri morning. High pressure will move off the coast Friday into Saturday. Onshore flow Friday will become southerly on Saturday. Winds may approach small craft advisory levels by late in the day. && .FIRE WEATHER... MODIS and VIIRS True color images from yesterday revealed that significant drying has occurred across northern VA and north central MD especially in Washington, Frederick and western Loudoun counties. Record high temperatures likely Wed with Rh's dropping into the low twenties as winds become westerly. Red flags conditions are not expected since winds are expected to remain below criteria, but an elevated fire weather threat will exist due to low humidities and drying fuels. && .TIDES/COASTAL FLOODING... Light south flow has raised water levels about one foot above normal. No coastal flooding is expected with this lesser high tide during the day today (though Straits Pt and Annapolis will be close), but is expected for sensitive locations for the preferred high tide cycle tonight. && .CLIMATE... Unseasonably hot weather will return to the area briefly on Wednesday. Here is a list of record daily high and warm low temperatures for September 14th. Washington DC area (Ronald Reagan National Airport, DCA) Record daily high temperature: 94 (1981, 1980 and 1915) Record daily high minimum temperature: 75 (2008 and 1961) Baltimore MD area (Baltimore-Washington International Thurgood Marshall Airport, BWI) Record daily high temperature: 94 (1931) Record daily high minimum temperature: 74 (1915) Dulles International Airport VA (IAD) Record daily high temperature: 95 (1998) Record daily high minimum temperature: 71 (2008) && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...BAJ/LFR NEAR TERM...BAJ/LFR SHORT TERM...LFR LONG TERM...ADS AVIATION...BAJ/ADS/LFR MARINE...BAJ/ADS/LFR FIRE WEATHER...lfr/baj TIDES/COASTAL FLOODING...baj CLIMATE...lwx  FXUS61 KLWX 030755 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 355 AM EDT Mon Oct 3 2016 .SYNOPSIS...High pressure will build southward into the region tonight through early Friday. Hurricane Matthew may track along or offshore the southeast U.S. and mid-Atlantic coasts Thursday night through the end of the week. && .NEAR TERM /THROUGH TUESDAY/...A few showers have been affecting ncntrl and northeast MD during the past couple of hrs, but these are now moving into the MD eastern shore and Delaware. Showers are also developing now over Charles county MD. Low clouds and/or fog have also been developing over eastern WV...nrn and cntrl VA. Fog is evident over the Shenandoah valley on the latest MODIS- Aqua nighttime microphysics product. Will monitor fog potential over the next svrl hrs to see whether a dense fog advzy may be needed or not. After morning fog burns and/or low clouds mix out, light NW flow will take place leading to mostly sunny skies east of the Blue Ridge and partly cloudy skies west. Subsidence will build in behind departing trof leading to a nice early fall day with temps in the mid 70s. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...High pressure will begin to build southward into the area from northern New England tonight. A stratus layer may develop over southwest VA late tonight under a northeast flow. Increasing pres gradient/winds will likely prevent fog from forming. Sfc flow begins to turn more easterly Tue with low clouds possibly advecting from the east in the afternoon. Onshore flow strengthens Tue night into Wed which may result in low clouds and some drizzle along and east of the Appalachians and Blue Ridge mtns. && .LONG TERM /THURSDAY THROUGH SUNDAY/...High pressure will be in place across much of the Mid-Atlantic region and New England Thursday. Onshore flow will persist and low clouds...drizzle and fog are possible through Friday. Northeast flow and cloud cover will keep conditions near normal with max temps in the U60s/L70s through Saturday. Hurricane Matthew is expected to be move across the Bahamas at the end of the work week and continue northward this weekend. There is a high level of uncertainty regarding the track of the hurricane as it moves north of the Bahamas this weekend. Please consult the National Hurricane Center for the most up to date forecasts regarding Hurricane Matthew. && .AVIATION /07Z MONDAY THROUGH FRIDAY/...LIFR conditions possible at KCHO and KMRB early this morning. Conditions improve to VFR after 13Z. Stratus clouds possible again tonight in northeast flow with some cigs restrictions. Higher probs of MVFR/IFR conditions Tue night and early Wed as onshore flow deepens. Flight restrictions possible late this week as onshore flow persists. && .MARINE...Winds less than 10 kt through this evening, then begin to strengthen late tonight through Wed with SCA conditions possible beginning Tue afternoon which may persist through the end of the week. && .TIDES/COASTAL FLOODING...No coastal flooding expected through tonight. Increasing onshore flow Tue and Wed will likely result in minor coastal flooding at Straits Pt and Annapolis Tue night and Wed. Water levels may rise further at the end of the week as winds strengthen as Matthew moves along or offshore the southeast U.S. and mid-Atlc coasts. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...HSK AVIATION...HSK/LFR MARINE...HSK/LFR TIDES/COASTAL FLOODING...LFR