Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/05/15


AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
958 AM MST TUE MAR 3 2015 .UPDATE... ISSUED AT 958 AM MST TUE MAR 3 2015 COLD FRONT HAS PUSHED THROUGH EASTERN COLORADO ALREADY THIS MORNING. TEMPERATURES ARE EXPECTED TO SLOWLY FALL THROUGH THE DAY. UPDATED TEMPERATURE GRIDS TO REFLECT THE COLDER START TO THE MORNING. LIGHT SNOW HAS FORMED OVER THE DENVER AREA DUE TO UPSLOPE BEHIND THE FRONT. EXPECT LIGHT SNOW TO LINGER THROUGH THE DAY WITH SNOW ACCUMULATION AROUND AN INCH WITH SLIGHTLY MORE POSSIBLE NEAR THE FOOTHILLS AND UNDER SNOW BANDS. THE HRRR AND OTHER SHORT TERM MODELS STILL HAVE NOT CAUGHT ON TO THE LIGHT SNOW THIS MORNING...SO EXPECT SNOW AMOUNTS TO BE A LITTLE HIGHER THAN IN THE MODELS THROUGH THIS AFTERNOON. A BAND OF SLIGHTLY HEAVIER SNOW IS OVER BOULDER...LARIMER AND WELD COUNTIES. MORNING SOUNDING AT KDNR SHOWED STEEP LAPSE RATES UP TO ABOUT 550 MB. SO ADDITIONAL SNOW SHOWERS WILL REMAIN POSSIBLE THROUGH THE DAY WHICH WILL PRODUCE HEAVIER SNOW FOR A SHORT TIME. HEAVIEST SNOW AND BEST COVERAGE IS STILL EXPECTED LATE THIS AFTERNOON AND TONIGHT AS AN UPPER LEVEL TROUGH PROVIDES ADDITIONAL LIFT. IN ADDITION TO THIS...A SECONDARY PUSH FROM THE NORTH MAY PRODUCE A LINE OF HEAVIER SNOW THAT WILL MOVE SOUTH ACROSS THE AREA. WILL KEEP WINTER WEATHER HIGHLIGHTS AS IS. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 446 AM MST TUE MAR 3 2015 MODELS CONTINUE A TREND OF SLIGHTLY SLOWING THE INCOMING SYSTEM. THIS LOOKS CORRECT SO THE MAIN ADJUSTMENT HAS BEEN TO SLOW THINGS DOWN BY 3-6 HOURS. COLD FRONT COMING ACROSS THE BORDER AND SHOULD BE THROUGH DENVER BY ABOUT 7 AM. ONE GOOD SHOWER BAND HAS FORMED AROUND CHEYENNE BUT IS TIED TO THE UPPER FEATURES...NOT THE COLD FRONT. AIRMASS IS ACTUALLY DRYING FROM THE WEST OVERALL AT THIS TIME...THOUGH THERE ARE STILL SOME SHALLOW SHOWER BANDS AND ENOUGH MOISTURE FOR OROGRAPHIC SNOW TO CONTINUE ON THE RIDGES. SO FOR THIS MORNING THE LOW LEVELS WILL BECOME MORE SUPPORTIVE OF SHOWERS...BUT THERE WILL BE LESS UPPER LEVEL SUPPORT. I REDUCED THE COVERAGE OF SHOWERS ON THE PLAINS THIS MORNING BUT THERE WILL LIKELY STILL BE SOME. THIS AFTERNOON THE LOW LEVEL COLD AIR DEEPENS WHILE UPSLOPE CONVERGENCE DEVELOPS ON THE EAST SIDE OF THE FRONT RANGE. THERE IS COOLING ALOFT WITH DESTABILIZATION AND THE NEXT AREA OF LIFT MOVES INTO THE MOUNTAINS AND NORTHERN AREAS...AND ACROSS THE REST OF OUR AREA BY EARLY EVENING. PRETTY GOOD CONSENSUS ON WIDESPREAD 2-3 INCHES OF SNOW AS THIS FEATURE PASSES IN THE LATE AFTERNOON AND OVERNIGHT...PLUS THE OROGRAPHIC INFLUENCES. ENVIRONMENT WILL BE FAVORABLE FOR A GOOD RESPONSE TO THE LOW LEVEL CONVERGENCE THIS EVENING...NOT SUPER UNSTABLE BUT A DEEP LAYER OF WEAK STABILITY. FOR THIS REASON PLANNING ON DECENT ENHANCEMENT IN AND NEAR THE FOOTHILLS...AND ALSO A PERIOD OF PRETTY GOOD OROGRAPHIC SNOW IN THE HIGHER MOUNTAINS IN THE LATE AFTERNOON/EARLY EVENING WHILE THERE IS BOTH INSTABILITY AND WIND. EXTENDED THE MOUNTAIN WARNING THROUGH TONIGHT...AND ISSUED AN ADVISORY FOR THE FOOTHILLS...DENVER/BOULDER AND DOUGLAS AND ELBERT COUNTIES WHERE THIS ENHANCEMENT WILL LIKELY CREATE SEVERAL HOURS OF MODERATE TO HEAVY SNOW. HOPING THE HEAVIEST TIME FOR DENVER WILL BE AFTER RUSH HOUR...BUT AT A MINIMUM THINGS WILL LIKELY BE GOING DOWNHILL WITH SOME SNOWFALL AND COOLING TEMPERATURES. AREAS JUST EAST OF THE ADVISORY MAY WIND UP NEEDING ONE...ESPECIALLY IF THE WIND ON THE PLAINS LASTS LONGER THAN EXPECTED. THE CURRENT EXPECTATION IS THAT THE STRONGEST WINDS WILL OCCUR BEFORE THERE IS MUCH SNOW ON THE GROUND. SNOW WILL BE DECREASING FROM NORTH TO SOUTH LATE TONIGHT THOUGH THERE WILL LIKELY STILL BE LIGHT SNOW IN DENVER ALL NIGHT. BUMPED TEMPERATURES UP SLIGHTLY THIS MORNING FOR THE FRONT TIMING...BUT THEY WILL BE COLDER THIS AFTERNOON. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 446 AM MST TUE MAR 3 2015 MAIN AXIS OF UPPER LEVEL TROUGH WILL BE MOVING ACROSS ERN CO WED MORNING AND THEN BE EAST OF AREA BY 18Z. CROSS-SECTIONS STILL SHOW WEAK UPSLOPE COMPONENT THRU MID MORNING WITH QUITE A BIT OF MOISTURE SO THERE WILL LIKELY BE SOME LIGHT SNOW FM DENVER SOUTH ACROSS THE PALMER DIVIDE INTO THE FOOTHILLS. EXPECT MOST OF THIS ACTIVITY WILL GRADUALLY END BY MID TO LATE MORNING. OTHERWISE DRIER AIR WILL SPREAD ACROSS THE RGN BY AFTN WITH DECREASING CLOUDS AND ONLY A A SLIGHT CHC OF -SN IN THE MTNS. AFTN HIGHS WILL BE WELL BLO NORMAL AS READINGS OVER NERN CO RANGE FROM THE UPPER TEENS TO LOWER 20S. ON THU A WK DISTURBANCE WILL MOVE ACROSS THE AREA IN NW FLOW ALOFT HOWEVER THIS FEATURE HAS NO MOISTURE WITH IT SO WILL KEEP FCST DRY. AS FOR HIGHS 850-700 MB TEMPS RISE AROUND 10-11 DEGREES C BY LATE AFTN SO SHOULD SEE READINGS WRM INTO THE 35 TO 40 DEGREE RANGE OVER NERN CO WITH LOWER TO MID 40S OVER THE FAR NERN CORNER. FOR FRI DRY NWLY FLOW ALOFT WILL CONTINUE WITH 850-700 MB TEMPS RISING ANOTHER 3- DEGREES C WHICH SHOULD ALLOW FOR HIGHS TO REACH THE 45 TO 50 DEGREE RANGE OVER NERN CO. OVER THE WEEKEND NWLY FLOW ALOFT WILL REMAIN OVER THE AREA WITH SOME MOISTURE EMBEDDED IN THE FLOW. THUS MAY SEE A CHC OF LIGHT SNOW IN THE MTNS ESPECIALLY SAT AFTN AND EVENING AS A WK DISTURBANCE MOVES ACROSS. OVER NERN CO A COOL FNT WILL MOVE ACROSS LATE FRI NIGHT INTO SAT. CROSS-SECTIONS DO NOT SHOW MUCH MOISTURE WITH THIS FNT SO WILL KEEP FCST DRY FOR NOW. HIGHS WILL BE IN THE LOWER TO MID 40S OVER THE PLAINS ON SAT AND THEN SLIGHTLY WARMER ON SUN WITH READINGS IN THE 45 TO 50 DEGREE RANGE. FOR EARLY NEXT WEEK THE FLOW ALOFT WILL CONTINUE NWLY WITH NOT MUCH MOISTURE SHOWN SO WILL NOT MENTION ANY PCPN. TEMPS WILL CONTINUE TO MODERATE WITH READINGS IN THE LOWER TO MID 50S ACROSS NERN CO ON MON. && .AVIATION...(FOR THE TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 958 AM MST TUE MAR 3 2015 LIGHT SNOW WILL SLOWLY INCREASE OVER THE DENVER AREA AFTER 21Z. VISIBILITY IS EXPECTED TO REMAIN 2-5 MILES THROUGH 21Z AND THEN LOWER. CEILINGS ARE EXPECTED TO STAY BELOW 2000 TODAY AND BE LOWER TONIGHT. POCKETS OF HEAVIER SNOW MAY REDUCE VISIBILITY TO A HALF MILE FOR A SHORT TIME. NORTH TO NORTHEAST WINDS UP TO 20 KNOTS WILL SLOWLY DECREASE THROUGH THE NEXT 24 HOURS. WINDS MAY SHIFT EASTERLY FOR A SHORT TIME BUT WILL BOUNCE BACK TO THE NORTH-NORTHEAST WITH A SECOND PUSH FROM THE NORTH AROUND 03Z. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 5 AM MST WEDNESDAY FOR COZ035-036-039>041. WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY FOR COZ031-033. && $$ UPDATE...MEIER SHORT TERM...GIMMESTAD LONG TERM...RPK AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1037 PM EST WED MAR 4 2015 .SYNOPSIS... A FRONT WILL STALL SOUTH OF NEW ENGLAND OVERNIGHT. LOW PRESSURE WILL PUSH ALONG THE FRONT WITH ANOTHER ROUND OF SNOW OVERNIGHT INTO THURSDAY...MAINLY ACROSS SOUTHERN CT...RI...AND SOUTHEAST MA. HIGH PRESSURE WILL BUILD IN FOR FRIDAY THROUGH THIS WEEKEND...BRINGING DRY CONDITIONS WITH COLDER THAN NORMAL TEMPERATURES. A WEAKENING FRONT MAY BRING SOME LIGHT SNOW SHOWERS ON MONDAY. ANOTHER COLD FRONT MAY APPROACH TOWARD THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 1025 PM UPDATE... 00Z NAM AND THE LATEST HRRR CONTINUE TO INDICATE A SHARP NORTHERN CUTOFF TO THE SNOW. THESE MODEL FORECASTS...IN COMBINATION WITH RADAR TRENDS...HAVE GIVEN SOME ADDED CONFIDENCE FOR NORTHERNMOST AREAS OF MASSACHUSETTS. HAVE REDUCED POPS AND HAVE TRIMMED SNOWFALL EVER SO SLIGHTLY SUCH THAT THERE IS NONE FORECAST FOR FAR NORTHERN PORTIONS OF FRANKLIN...WORCESTER...MIDDLESEX...AND ESSEX COUNTIES. FARTHER TO THE SOUTH...THE NAM HAS ACTUALLY INCREASED ITS TOTAL PRECIPITATION FOR THE CAPE AND ISLANDS BUT SINCE IT IS LIKELY TO START AS MIXED PRECIPITATION...HAVE NOT CHANGED THE SNOWFALL FORECAST AT THIS TIME. PRECIPITATION IS INCREASING ALONG THE SOUTH COAST AT THIS TIME...IN AGREEMENT WITH ALL MODELS AND WITH THE CURRENT FORECAST. TEMPERATURES...AFTER DROPPING TO THE MID 30S...HAVE RISEN TO THE UPPER 30S ALONG THE COAST. WILL BE WATCHING THE SITUATION CLOSELY...IN CASE SNOWFALL FORECAST AMOUNTS NEED TO BE LOWERED. FOR NOW THEY SEEM REASONABLE. PREVIOUS DISCUSSION... WE WILL MAINTAIN WINTER STORM WARNING FOR ISLANDS /4 TO 7 INCHES/. OUR HIGHEST CONFIDENCE IS ON LOWER END OF THAT RANGE BASED UPON MODEL CONSENSUS. WE WILL CONVERT WINTER STORM WATCH ON S COASTAL RI/MA TO WINTER WEATHER ADVISORY /2 TO 5 INCHES/ WITH HIGHER TOTALS FOCUSED ON COAST AND CAPE COD AND LOWER END OF RANGE CLOSER TO PROVIDENCE. THERE ARE SEVERAL RED FLAGS TO CONSIDER AGAINST GOING WITH OVERLY HIGH AMOUNTS INCLUDING BEING ABLE TO OVERCOME INITIALLY WARM LOW LEVEL TEMPERATURES...CONTINUED SOUTHWARD NUDGE ON MODELS AND FACT THAT BEST LIFT IN MAX SNOW GROWTH ZONE IS LIMITED TO LATE TONIGHT AND EARLY THU MORNING NEAR S COAST. FACT THAT HIGH-RES MODELS SHOW LITTLE IF ANY SNOWFALL N OF MASS PIKE MAKES SENSE GIVEN WE EXPECT A SHARP GRADIENT ON NORTHERN EDGE OF SYSTEM...SO IF ANYTHING SNOWFALL TOTALS ALONG AND N OF MASS PIKE MAY BE A BIT OVERDONE. NOTE PROBABILISTIC SNOW FORECASTS WILL SHOW RATHER LARGE RANGE /IE FEW INCHES TO NEARLY A FOOT ON NANTUCKET/ DUE TO UNCERTAINTY IN TEMPERATURE PROFILE AND TO SOME DEGREE HOW FAR CLOSE OR OFFSHORE DOES AXIS OF HEAVIEST QPF LIE. THIS LEADS US TO PLAY FORECAST MORE CONSERVATIVELY DUE TO REASONS MENTIONED ABOVE. FOR THOSE WONDERING ABOUT BOS SNOWFALL RECORD...WE NEED 1.9 INCHES TO TIE 1995-96. OUR LATEST FORECAST HAS ABOUT 0.7 INCH AT BOS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... FOCUS FOR STEADIER SNOWFALL WILL BE OVER SE NEW ENGLAND THU MORNING WITH RAPID DRYING FROM NW BRINGING CLEARING TO INTERIOR BY AFTERNOON. EXPECT ADDITIONAL 2 TO 4 INCHES DURING DAY ACROSS S COASTAL RI/MA AND CAPE COD/ISLANDS WITH LESS THAN INCH AS FAR N AS MASS PIKE. DEFINITELY COLDER DAY AHEAD WITH HIGHS ONLY IN 20S EXCEPT NEAR 30 ON CAPE AND ISLANDS. CLEARING SETS IN ACROSS ALL OF REGION THU NIGHT AS SYSTEM HEADS FARTHER OUT TO SEA AND HIGH PRESSURE BUILDS IN. ANOTHER SHOT OF BITTERLY COLD AIR ARRIVES WITH LOWS FROM ABOUT 5 BELOW TO 5 ABOVE ACROSS INTERIOR TO TEENS CLOSER TO COAST. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... * HIGH PRESSURE ARRIVES FRIDAY * MOISTURE-STARVED COLD FRONT MOVES THROUGH THIS WEEKEND * UNCERTAIN FORECAST EARLY NEXT WEEK MODELS ARE IN FAIRLY GOOD AGREEMENT GOING INTO THIS WEEKEND. THERE ARE SOME MINOR DISCREPANCIES IN TIMING OF A COLD FRONT INTO THIS WEEKEND. MORE SIGNIFICANT DIFFERENCES DEVELOP SATURDAY NIGHT INTO SUNDAY. THE GFS IS VERY AGGRESSIVE IN DEVELOPING A SURFACE LOW NEAR THE GREAT LAKES...AND IS OFF ON ITS OWN IN DOING SO. AT THIS POINT...AM FAVORING A CONSENSUS BLEND OF THE OTHER GUIDANCE DUE TO FAIRLY BROAD MID-LEVEL TROUGH OVER THE NORTHEAST. HIGH PRESSURE SOUTH OF NEW ENGLAND IS THE MAIN THEME EARLY NEXT WEEK. THERE IS SOME QUESTION AS TO HOW CLOSE A COLD FRONT CAN GET TO SOUTHERN NEW ENGLAND TOWARD MID WEEK. FRIDAY...A HIGH PRESSURE BECOMES SUPPRESSED TO OUR SOUTH AS A LOW PRESSURE MOVES INTO QUEBEC. THIS WILL KEEP LOWER TEMPERATURES... WELL BELOW NORMAL FOR EARLY MARCH...IN PLACE FOR SOUTHERN NEW ENGLAND. THIS WEEKEND...A SHORTWAVE PUSHES LOW PRESSURE THROUGH QUEBEC... ALLOWING A COLD FRONT TO MOVE THROUGH SOUTHERN NEW ENGLAND. AT THIS POINT...THIS FRONTAL PASSAGE APPEARS TO BE FAIRLY MOISTURE- STARVED...SO LITTLE IF ANY PRECIP WILL ACCOMPANY THIS FRONT. TEMPERATURES MODERATE A BIT...BUT REMAIN WELL BELOW NORMAL. EARLY NEXT WEEK...MODELS CONTINUE TO SHOW SIGNIFICANT DIFFERENCES WITH THE EVOLUTION OF THE MID LEVEL FLOW. 04/12Z GFS IS FASTER TO WARM UP THE LOWER ATMOSPHERE THAN BOTH ITS ENSEMBLE MEAN AND THE 04/12Z ECMWF. WHILE THINKING TEMPERATURES WILL EVENTUALLY BECOME HIGHER...AM NOT YET SOLD ON THE GFS TIMING. THIS WILL HAVE IMPLICATIONS FOR PRECIPITATION TYPE. WILL CONTINUE TO FAVOR A CONSENSUS APPROACH FOR THIS TIME RANGE. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE. POCKETS OF IFR PERSIST ACROSS PORTIONS OF CAPE COD AND THE ISLANDS. VFR CIGS ELSEWHERE. MVFR/IFR SPREADS N IN LIGHT SNOW TONIGHT...PROBABLY AS FAR N AS KBDL-KSFZ-KBOS...MAINLY DUE TO VSBY. LIGHT RAIN CHANGES TO SLEET AND SNOW CLOSER TO S COAST AFTER 06Z WHERE LIFR EXPECTED THROUGH DAYBREAK THU. VFR CIGS FARTHER N AND W. MVFR CIGS ALSO SPREADING FROM THE BERKSHIRES INTO WESTERN MA AND WESTERN CT BETWEEN 04Z AND 08Z. CONDITIONS SLOWLY IMPROVE THU FROM NW TO SE...WITH CAPE COD AND ISLANDS LAST TO IMPROVE 16Z-20Z. EXPECTED GENERAL SNOW ACCUMULATIONS... BOS/BAF/BDL/BED/ORH...1 INCH OR LESS PVD...2 INCHES FMH/HYA...3-4 INCHES ACK...5-7 INCHES KBOS TAF...HIGH CONFIDENCE. KBDL TAF...HIGH CONFIDENCE. OUTLOOK...FRIDAY THROUGH MONDAY... MODERATE CONFIDENCE. MAINLY VFR THROUGH THIS PERIOD. BRIEF MVFR CONDITIONS ARE POSSIBLE SATURDAY NIGHPREVIOUS DISCUSSION... && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE. MAINTAINING SCA ON OUTER WATERS AND BLOCK ISLAND/RI SOUNDS PRIMARILY DUE TO SEAS THROUGH THU OR THU NIGHT. COLD FRONT SLOWLY DROPS S OVERNIGHT WITH WIND SHIFT TO NW AND POSSIBLY A FEW GUSTS TO 25 KT. SPOTTY LIGHT RAIN WILL GIVE WAY TO SLEET AND SNOW LATE TONIGHT...WITH LOWEST VSBY FROM MIDNIGHT INTO THU MORNING. SNOW SHOULD MAINLY AFFECT S COASTAL WATERS THU BEFORE HEADING OFFSHORE THU NIGHT. HIGH PRESSURE BUILDING IN TO REGION MAY BRING PERIOD OF 25KT NW WIND GUSTS THU NIGHT...MAINLY ON OUTER WATERS. OUTLOOK...FRIDAY THROUGH MONDAY... HIGH CONFIDENCE. WINDS AND SEAS SLOWLY DIMINISH FRIDAY AS HIGH PRESSURE BUILDS OVER THE WATERS. THEY THEN INCREASE AGAIN...BUT ONLY MODESTLY OVER THIS WEEKEND AS A COLD FRONT APPROACHES...THEN CROSSES THE WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE NECESSARY ON THE OUTER WATERS FOR A PORTION OF THIS TIME. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MAZ023-024. WINTER WEATHER ADVISORY UNTIL 7 PM EST THURSDAY FOR MAZ020>022. RI...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR RIZ008. WINTER WEATHER ADVISORY UNTIL 7 PM EST THURSDAY FOR RIZ003>007. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ235-237-250- 254>256. && $$ SYNOPSIS...BELK/JWD NEAR TERM...JWD/GAF SHORT TERM...JWD LONG TERM...BELK AVIATION...BELK/JWD/GAF MARINE...BELK/JWD/GAF
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
821 PM EST WED MAR 4 2015 .SYNOPSIS... SEVERAL WAVES OF LOW PRESSURE WILL TRACK NORTHEASTWARD ALONG A COLD FRONTAL BOUNDARY TONIGHT AND THURSDAY. THIS COLD FRONTAL BOUNDARY WILL MOVE OFFSHORE THURSDAY NIGHT AND WILL GIVE WAY TO AN AREA OF HIGH PRESSURE MOVING INTO THE REGION ON FRIDAY. FOR THE WEEKEND AND EARLY NEXT WEEK, WE WILL ALTERNATE BETWEEN AREAS OF HIGH PRESSURE AND COLD FRONTS MOVING THROUGH THE REGION. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 800PM UPDATE...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR SOUTHERN NEW JERSEY...PARTS OF SOUTHEAST PENNSYLVANIA AND NORTHERN DELMARVA INCLUDING ALL OF DELAWARE. NUMEROUS STATIONS ARE REPORTING VISIBILITY OF 1/4 MILE OR LESS IN FOG. APPARENTLY MELTING SNOW EVAPORATED INTO THE LOWER ATMOS TODAY AND THEN SLIGHT COOLING AROUND SUNDOWN ENABLED THE FOG TO FORM. NOT SURE HOW LONG FOG WILL LAST BUT IT SHOULD BEGIN TO DISSIPATE WHEN HEAVIER PRECIP ARRIVES LATER THIS EVENING. CURRENT ADVISORY RUNS UNTIL MIDNIGHT. SOCIAL MEDIA HAS THE UPDATED WED EVENING BRIEFING PACKAGE AND REQUEST FOR OBSERVATIONS. WE WILL BE MONITORING MOSTLY OUR SKYWARN ACCOUNT AND PHI FB. THANK YOU VERY MUCH FOR ALL YOUR ASSISTANCE INCLUDING THE ENERGY TO HELP US DURING THE NIGHT. SAFETY FIRST. 545PM ESTF UPDATE: ADDED PATCHY FOG MUCH OF THE AREA THIS EVENING IN LIGHT WIND FRONTAL ZONE. HAVE DELAYED THE CHANGE TO SNOW AND SLEET IN NE PA AND NW NJ BY 2 HOURS. NO OTHER SIGNIFICANT CHANGES TO THIS FCST WILL POST BEFORE 730 PM. OTHERWISE TRENDS VIA 18Z AND 20Z HRRR SHOW A CHANGE TO SNOW FROM NORTH TO SOUTH SUCH THAT PHL SHOULD BE SEEING SNOW ACCUM AROUND 08Z WITH 2-3 INCHES NEAR AND N OF I-80 BY 09Z. COLD FRONT SHOULD BEGIN TO PUSH THROUGH THE REGION LATE THIS EVENING. AS IT DOES SO, THE PRECIPITATION TYPE WILL CHANGE FROM RAIN TO WINTRY PRECIPITATION. EXACTLY WHAT KIND OF WINTRY PRECIPITATION WILL DEPEND ON WHERE IN THE REGION AND WHAT TIME THE FRONT FINALLY COMES THROUGH. FOR THE POCONOS AND LEHIGH VALLEY IN PA AND NORTHWEST NJ, IT LOOKS LIKE A PRETTY FAST AND CLEAN TRANSITION FROM RAIN TO SNOW BY LATE THIS EVENING. FOR THE URBAN CORRIDOR, CENTRAL AND SOUTHERN NJ, AND FAR NORTHERN DELMARVA, A WARM NOSE IS EXPECTED TO DEVELOP AROUND OR JUST AFTER MIDNIGHT IN THE LOW LEVELS, MAKING A BRIEF PERIOD OF A WINTRY MIX OF SLEET AND SNOW POSSIBLE BEFORE CHANGING OVER TO ALL SNOW. SOUTHERN DELMARVA SHOULD STAY MOSTLY RAIN THROUGH THE OVERNIGHT HOURS UNTIL JUST BEFORE SUNRISE - WHICH IS DISCUSSED MORE IN THE SHORT TERM SECTION. THIS ALL DEPENDENT ON THE TIMING OF THE COLD FRONT AND THE TEMPERATURES, WHICH GUIDANCE HAS BEEN POOR FOR TEMPERATURES MOST OF THE DAY. AS FOR SNOW AMOUNTS, THE AXIS OF HEAVIEST QPF HAS SHIFTED FURTHER SOUTH, HOWEVER THIS WILL ALL BE DEPENDENT ON THE TIMING OF THE CHANGE OVER, WHICH AS MENTIONED BEFORE IS STILL UNCERTAIN. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... RECORD DAILY SNOWFALLS POSSIBLE AT KILG AND KACY. PLS SEE CLIMATE SECTION FOR DETAILS ON THE BIG FOUR CLIMATE SITES. THE WARM NOSE WILL STILL BE PRESENT, AND SHOULD IN FACT BE A BIT DEEPER OVER SOUTHERN DELMARVA AS THEY DROP NEAR AND BELOW FREEZING NEAR SUNRISE. AS SUCH, COULD SEE A MIX OF FREEZING RAIN AND SLEET BEFORE IT CHANGES OVER TO ALL SNOW NO LATER THAN MID MORNING. ON THE OTHER SIDE OF THE REGION, DRIER AIR MOVING INTO THE POCONOS AND NW NJ COULD ERODE AND END THE PRECIPITATION FOR THOSE AREAS BY MID DAY. DRY AIR ADVECTION WILL TAKE OVER ACROSS MUCH OF THE REST OF THE AREA THROUGH THE AFTERNOON, ALLOWING THE PRECIPITATION TO TAPER OFF ALMOST EVERYWHERE BY LATE AFTERNOON. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... FAIRLY QUIET WITH A GENERAL NORTHWEST FLOW PATTERN OF ALTERNATING COLD FRONTS AND WEST-SOUTHWESTERLY FLOW WARM-UPS AHEAD OF THESE FRONTS. SLIGHT TO LOW PRECIPITATION CHANCES AHEAD OF THESE FRONTS, FOCUSED NORTH. THURSDAY NIGHT THROUGH SATURDAY: A COLD FRIDAY MORNING IS ON TAP WITH SNOWCOVER IN PLACE, CLEAR SKIES AND MAINLY LIGHT WINDS UNDER 10 MPH. RADIATIONAL COOLING SHOULD ALLOW FOR A QUICK TEMPERATURE DROP AFTER CLOUDS CLEAR. WENT COLDER THAN MAV AND MET GUIDANCE SETS CLOSER TO THE MODELED TWO METER TEMPERATURES FROM THE GFS. HIGH PRESSURE BUILDS INTO THE REGION KEEPING THIS PERIOD DRY WITH A EVENTUAL SWING FROM NORTHWEST TO SOUTHWEST WINDS AND MODERATING TEMPERATURES BY SATURDAY. TRENDED COLDER THAN THE MET AND MAV AT NIGHT DUE TO SNOWCOVER AND WARMER DURING THE DAY. THESE GUIDANCE SETS HAVE BEEN RUNNING WITH A COLD BIAS IN THE DAYTIME. SOUNDINGS ALSO YIELD THE POTENTIAL FOR SOME WIND GUSTS AROUND 15 MPH SATURDAY AFTERNOON. SATURDAY NIGHT AND SUNDAY: A COLD FRONT WILL DECAY INTO A TROUGH ACROSS NEW ENGLAND BY SUNDAY MORNING PROVIDING AN INCREASE IN CLOUDS AND PERHAPS A LOW CHANCE FOR RAIN AND SNOW SHOWERS ACROSS FAR NORTHERN PARTS OF THE REGION, CLOSER TO THE FRONT. A FEW 06Z GEFS MEMBERS HAVE MOISTURE FROM THE GULF COMING NORTH AS WELL, FOR NOW WILL GO WITH THE MODEL CONSENSUS AWAY FROM THIS IDEA. SNOWCOVER SHOULD LESS OF A CONCERN WITH TEMPERATURES BY SUNDAY. WITH MORE CLOUDS AROUND THE ENSEMBLE GUIDANCE FROM WPC IS PREFERRED FOR MOST ELEMENTS. WINDS ARE MORE IN LINE WITH THE NAM/GFS MODELS THOUGH. SUNDAY NIGHT THROUGH WEDNESDAY: ONCE AGAIN HIGH PRESSURE IS IN CONTROL IN THE REGION WITH GENERAL WEST WINDS. THIS WILL RESULT IN A BRIEF PERIOD OF COOLER TEMPERATURES SUNDAY NIGHT BEFORE SPRING LIKE DAYS ON MONDAY THROUGH WEDNESDAY. A WEAK FRONTAL BOUNDARY AGAIN LOOKS TO FOCUS ON NEW ENGLAND FOR MONDAY, ANOTHER LOW CHANCE OF PRECIPITATION. THEN THIS WILL BE FOLLOWED BY ANOTHER HIGH PRESSURE SYSTEM. THE AIRMASS BY TUESDAY AND WEDNESDAY WILL BE THE WARMEST IN SOME TIME ACROSS THE REGION. LIKED THE DIRECTION OF THE ENSEMBLE GUIDANCE TO TREND TEMPERATURES SEVERAL DEGREES WARMER THAN THE MODELED TWO METER TEMPERATURES. THE MODELED TWO METER TEMPS LOOK TO COOL SHOULD SOME SOUTHERLY COMPONENT GET INVOLVED, THIS LOOKS LIKE IT HAS A FAIR CHANCE OF OCCURRING BY WEDNESDAY. FORECAST HIGH OF 56 AT PHL WEDNESDAY, I`M SURE THIS WILL BE WELCOME TO MANY. LOW PRESSURE THAT FORMS IN THE GULF OF MEXICO TUE-WED LOOKS TO STAY SOUTH OF OUR REGION ATTM. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...MVFR CONDS IN RAIN/FOG VARIABLE LIFR IN PATCHY DENSE FOG THIS EVENING. THEN AS THE COLDER NORTHWEST WIND INCREASES, THE CHANGE FROM RAIN TO SLEET/FREEZING RAIN FOR 1-2 HOURS AND THEN IFR SNOW OCCURS. PLEASE SEE THE 00Z TAFS FOR DETAILS. MY CONFIDENCE IN MDT 1/2 MI SNOW IS BELOW AVERAGE. HOWEVER, I AM CONFIDENT THAT WIDESPREAD PLOWING AND EXTENSIVE DELAYS WILL DEVELOP BY SUNRISE THURSDAY. NORTH WIND GUSTS TO 18 KT BY 11Z THURSDAY. THURSDAY...IFR SNOW IN THE MORNING WITH TEMPERATURES FALLING INTO THE 20S AT ALL TAF SITES BY 15Z. NORTH WIND GUSTING TO 20 KT. CONDITIONS SHOULD IMPROVE TO VFR FROM NORTH TO SOUTH DURING THE AFTERNOON. PLOWING OPERATIONS AND EXTENSIVE DELAYS ARE ANTICIPATED WITH WIDESPREAD EVENT TOTALS OF 4 TO 8 INCHES. OUTLOOK... THURSDAY NIGHT: IMPROVING TO VFR BY MID-EVENING. NORTHWEST WIND AROUND 10 KNOTS. FRIDAY AND FRIDAY NIGHT: VFR, NORTHWEST WIND 10 KNOTS OR LESS. SATURDAY THROUGH SUNDAY NIGHT: VFR, WEST TO SOUTHWEST WIND AROUND 10 KNOTS, GUSTS AROUND 15 KNOTS SATURDAY AFTERNOON. MID-LEVEL CLOUDS SATURDAY NIGHT AND SUNDAY MORNING, PASSING RAIN/SNOW SHOWER CAN NOT BE RULED OUT FOR ABE. MONDAY AND MONDAY NIGHT: VFR, MID-LEVEL CLOUDS. && .MARINE... WAVES ALONG THE COASTAL WATERS WILL CONTINUE TO REMAIN NEAR OR ABOVE 5 FT. AFTER MIDNIGHT, WINDS INCREASE WITH GUSTS ABOVE 25 KT POSSIBLE. THEREFORE THE SMALL CRAFT ADVISORY CONTINUES THROUGH THURSDAY EVENING ALONG THE COASTAL WATERS. ON THE BAY, A FEW GUSTS NEAR 20KT ARE POSSIBLE, BUT CONDITIONS SHOULD GENERALLY REMAIN BELOW SCA CRITERIA. OUTLOOK.. SEAS LOOK TO REMAIN BELOW FIVE FEET THROUGHOUT THE ENTIRE OUTLOOK PERIOD, WITH SEAS NEAR FIVE FEET EARLY THURSDAY NIGHT. THE FORECAST IS ABOUT A FOOT HIGHER THAN WAVEWATCH. NORTHWEST WIND GUSTS AROUND 20 KNOTS MAY OCCUR THURSDAY EVENING. OTHERWISE WIND GUSTS SHOULD STAY UNDER 20 KNOTS. SOME FREEZING SPRAY MAY OCCUR THURSDAY NIGHT AND EARLY FRIDAY IN ICE FREE WATERS. CONFIDENCE IS NOT HIGH FOR ANY MODERATE FREEZING SPRAY IN TERMS OF DURATION AND LIKELIHOOD, MAY JUST LAST A FEW HOURS IF IT OCCURS. WITH SOME MODERATE FREEZING SPRAY IN THE GRIDS, DID INCLUDE MENTION IN THE HWO. && .HYDROLOGY... MODELS CONTINUE TO SHOW A DECENT AMOUNT OF QPF ACROSS THE AREA TONIGHT INTO THURSDAY. IN GENERAL AND BREAKING THE CWA INTO THIRDS, A CHANGEOVER TO SLEET OR SNOW IS EXPECTED ACROSS THE NORTHERN THIRD BY AROUND MIDNIGHT, THE MIDDLE THIRD BY DAYBREAK, AND THE SOUTHERN THIRD BY MID-MORNING TOMORROW. WITH THE GROUND BEING FROZEN EVERYWHERE, ANY RUNOFF WILL BE VERY EFFICIENT BEFORE THE CHANGEOVER. MORNING MODELS CONTINUE TO PRODUCE BETWEEN 0.50 TO 1.00 INCH OF QPF BEFORE THE CHANGEOVER. WITH THIS AMOUNT, WE FEEL NUISANCE POOR DRAINAGE AND LOW LYING FLOODING WILL BE THE MOST LIKELY OUTCOME. WITH MORE SNOW OR SLEET EXPECTED ACROSS THE NORTHERN HALF OF THE CWA, WE`RE LESS CONCERNED ABOUT FLOODING THERE. MODELED SOLUTIONS SUGGEST WE WOULD NEED BETWEEN 1.50 TO 2.00 INCHES OF LIQUID (OVER A 6 TO 12 HOUR PERIOD), EITHER IN THE FORM OF ALL RAIN OR RAIN AND MELTING SNOW TO HAVE OUR SOUTHERN CREEKS AND STREAMS LEAVE THEIR BANKS. NONE OF OUR RIVER FORECAST POINTS ARE FORECAST TO HIT FLOOD STAGE OR EVEN CAUTION STAGE. THE SHORT TERM GOOD NEWS IS THAT RAIN WILL CHANGE OVER TO SNOW QUICKER ACROSS PLACES THAT HAVE A SNOWPACK AND WHERE MORE RAIN IS EXPECTED, THERE IS LESS SNOW PACK. THE LONGER TERM BAD NEWS IS THAT WE`RE POTENTIALLY KICKING THE CAN DOWN THE LINE AND JUST ADDING TO OUR SNOWPACK FOR A FUTURE MELT. WITH THE RAINFALL, THE FLOW ON AREA CREEKS AND STREAMS WILL INCREASE. THIS COULD START TO MOVE ICE, AND IN A WORST CASE SCENARIO, CREATE RESTRICTIONS OR JAMS. THE GOOD NEWS IS WE`VE SEEN SOME RECESSION/MELT THE LAST FEW DAYS. && .CLIMATE... CLIMATE: WITH A SNOWCOVER IN PLACE AND ANOTHER MODIFIED ARCTIC AIRMASS SETTLING INTO THE REGION AND RADIATIONAL COOLING OCCURRING, WE HAVE ANOTHER CHANCE FOR MORE RECORD LOWS ACROSS THE REGION. FRIDAY 3/6 RECORD LOWS ACY 10 1888 PHL 10 1978 ILG 11 1926 ABE 7 1960 TTN 7 1872 GED 10 1978 RDG 7 1978 MPO -5 1909 THE CURRENT FORECAST CURRENTLY HAS MOST LOCATIONS BREAKING THERE RECORD LOW ON FRIDAY MORNING. THE ONE EXCEPTION WOULD BE MOUNT POCONO. SATURDAY 3/7 RECORD LOWS ACY 10 1890 PHL 9 1960 ILG 11 1960 ABE 1 1960 TTN 7 1890 GED 3 1960 RDG 10 1989 MPO -18 1911 MOST LOCATIONS ARE FORECASTED TO BE SEVERAL DEGREES WARMER THAN THE RECORD LOWS FOR SATURDAY MORNING. RECORD DAILY SNOWFALL FOR THURSDAY MARCH 5 KACY 0.3 - 1960 KILG 3.7 - 1981 KABE 7.0 - 1917 KPHL 8.8 - 1981 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THURSDAY FOR PAZ054-055- 061-062. WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR PAZ060- 101>106. DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR PAZ070-071- 101>106. WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR PAZ070-071. NJ...WINTER WEATHER ADVISORY UNTIL 7 PM EST THURSDAY FOR NJZ001-007- 008. WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR NJZ009-010- 012-015. DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NJZ015>027. WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR NJZ013-014- 016>027. DE...DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR DEZ001>004. WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR DEZ001-002. WINTER STORM WARNING FROM 3 AM TO 7 PM EST THURSDAY FOR DEZ003- 004. MD...DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MDZ008-012- 015-019-020. WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MDZ008-012- 015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR ANZ450>455. && $$ SYNOPSIS...GAINES NEAR TERM...AMC/DRAG/JOHNSON SHORT TERM...DRAG/JOHNSON LONG TERM...GAINES AVIATION...DRAG/GAINES/JOHNSON MARINE...DRAG/GAINES/JOHNSON HYDROLOGY... CLIMATE...
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
945 PM EST WED MAR 4 2015 .UPDATE...TEMPS REACHED THE MID 80S ACROSS THE AREA THIS AFTERNOON WITH JACKSONVILLE AIRPORT REACHING 85 DEGREES...ONE DEGREE SHY OF TYING TODAY`S RECORD. MOIST SOUTHERLY FLOW WILL KEEP THE LOW LEVEL MOISTURE PLENTIFUL AND IT WILL BE A VERY STICKY NIGHT WITH LOWS IN THE LOWER 60S. SEA FOG DEVELOPMENT OVER THE APALACHEE BAY AREA HAS BEEN ONGOING FOR THE LAST SEVERAL HOURS. BOTH THE HRRR AND NARRE DEPICT THIS FOG AND LOW STRATUS DRIFTING NORTHEAST INTO OUR WESTERNMOST FL AND GA COUNTIES. BASED ON THIS WE EXPECT THE BEST CHANCES FOR FOG DEVELOPMENT TO BE IN AND AROUND THE I-75 CORRIDOR. SEA FOG DEVELOPMENT WILL ALSO BE POSSIBLE IN OUR COASTAL GA COUNTIES LATE TONIGHT. RAIN CHANCES WILL BEGIN TO INCREASE TOMORROW AFTERNOON AS A FRONTAL SYSTEM MOVES IN FROM THE NORTHWEST. && .AVIATION... MODELS STILL DIFFER ON TIMING AND EXTENT OF IFR CIGS/VSBYS IN FOG IMPACTING TAF SITES AND WILL LIKELY BEGIN IN THE 06-09Z TIME FRAME AND LINGERING UNTIL THE 12-14Z TIME FRAME BEFORE LIFTING. 2000 FEET WINDS TONIGHT EXPECT TO INCREASE SW 25-30 KNOTS BY 09-12Z BUT WILL FALL JUST SHORT OF LOW LEVEL WIND SHEAR CRITERIA. && .MARINE... SEAS 2 TO 4 FEET WITH WINDS DECREASING TO AROUND 10 KNOTS OUT OF THE SOUTHWEST. HIGH PRESSURE BEGINS TO EXIT AS A FRONT MOVES INTO THE AREA TOMORROW. FLOW WILL SWITCH TO NORTHEAST AND BRING OUR NEXT CHANCE OF SWELL. RIP CURRENTS: LOW RISK TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... AMG 63 83 44 46 / 0 60 60 40 SSI 62 78 47 48 / 0 20 30 40 JAX 63 85 52 52 / 0 10 20 30 SGJ 65 82 57 57 / 0 0 20 30 GNV 63 85 57 60 / 0 0 10 10 OCF 63 85 60 66 / 0 0 10 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ HESS/SHULER/WALSH
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1235 PM EST TUE MAR 3 2015 .PREV DISCUSSION... /ISSUED 1037 AM EST TUE MAR 3 2015/ UPDATE... VERY FEW CHANGES THIS MORNING...MAINLY SOME TWEAKS TO ACCOUNT FOR CURRENT TRENDS AND DESPITE THE WIDESPREAD CLOUDS...TEMPS ARE RISING A LITTLE MORE QUICKLY THAN ANTICIPATED SO HAVE ADJUSTED HIGHS AND WILL UPDATE PRODUCTS SHORTLY. OTHERWISE...CONTINUED CLOUDS AND SPOTTY RAIN/DRIZZLE. TDP PREV DISCUSSION... /ISSUED 623 AM EST TUE MAR 3 2015/ PREV DISCUSSION... /ISSUED 315 AM EST TUE MAR 3 2015/ SHORT TERM /TODAY THROUGH WEDNESDAY/... WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK FRONT. RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT APPROACHES FROM THE NW. THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE. WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE METRO AREA. NLISTEMAA LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES. LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW. 20 && .AVIATION... 18Z UPDATE... WIDESPREAD IFR TO LIFR CONDITIONS FOR NORTHERN TAFS...MVFR CREEPING UP TO MCN/CSG. MCN/CSG WILL CONTINUE TO IMPROVE AND LIKELY SEE VFR LATER THIS EVENING...BUT NORTHERN TAFS WILL REMAIN IFR TO AT BEST BRIEFLY LOW MVFR THROUGH THE EVENING. EXPECT LIFR AGAIN OVERNIGHT ESPECIALLY NORTHERN TAFS AND CANNOT RULE OUT CIGS AS LOW AS 002...WITH GRADUAL LIFTING LATE MORNING WEDNESDAY. WILL PROBABLY SEE AT LEAST SOME MVFR BY THE END OF THE PERIOD. ESE WINDS ALL BUT MCN/CSG TO START...WITH SHIFT TO SW EXPECTED OVERNIGHT...CURRENT TIMING AROUND 08Z. COULD SEE LOW-END GUSTS ATL WEDNESDAY AFTERNOON. //ATL CONFIDENCE...18Z UPDATE... MEDIUM ON LIFTING POTENTIAL THIS AFTERNOON/EVENING. HIGH ON OVERNIGHT CIG TRENDS...MEDIUM ON ACTUAL CIGS. HIGH ON WINDS. TDP && .PRELIMINARY POINT TEMPS/POPS... ATHENS 55 49 72 54 / 60 30 10 70 ATLANTA 60 55 70 45 / 60 20 20 70 BLAIRSVILLE 54 47 62 42 / 70 70 50 70 CARTERSVILLE 55 52 69 40 / 60 40 40 70 COLUMBUS 75 60 75 54 / 30 10 10 60 GAINESVILLE 51 47 67 47 / 60 50 30 70 MACON 67 58 77 59 / 20 20 5 50 ROME 58 53 68 37 / 60 50 50 70 PEACHTREE CITY 63 56 71 48 / 50 20 20 70 VIDALIA 69 62 79 62 / 20 10 5 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1037 AM EST TUE MAR 3 2015 .UPDATE... VERY FEW CHANGES THIS MORNING...MAINLY SOME TWEAKS TO ACCOUNT FOR CURRENT TRENDS AND DESPITE THE WIDESPREAD CLOUDS...TEMPS ARE RISING A LITTLE MORE QUICKLY THAN ANTICIPATED SO HAVE ADJUSTED HIGHS AND WILL UPDATE PRODUCTS SHORTLY. OTHERWISE...CONTINUED CLOUDS AND SPOTTY RAIN/DRIZZLE. TDP && .PREV DISCUSSION... /ISSUED 623 AM EST TUE MAR 3 2015/ PREV DISCUSSION... /ISSUED 315 AM EST TUE MAR 3 2015/ SHORT TERM /TODAY THROUGH WEDNESDAY/... WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK FRONT. RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT APPROACHES FROM THE NW. THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE. WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE METRO AREA. NLISTEMAA LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES. LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW. 20 AVIATION... 12Z UPDATE... OLD FRONTAL BOUNDARY SITUATED ACROSS SOUTH GA THIS MORNING. THE BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. WEDGING HAS STARTED TO BUILD IN ACROSS THE NE PORTION OF THE STATE AS THE EASTERLY WINDS HAVE BECOME ESTABLISHED. REGIONAL RADAR SHOWS SOME PATCHY LIGHT RAIN/HEAVY DRIZZLE MAKING ITS WAY ACROSS THE NORTHERN TERMINAL SITES...IN ASSOCIATION WITH A PASSING SHORTWAVE. LOW CIGS SHOULD CONTINUE FOR MUCH OF THE DAY...HOWEVER A BRIEF PERIOD OF MVFR IS POSSIBLE DURING THE LATE AFTERNOON. IFR EXPECTED AGAIN OVERNIGHT. EAST WINDS WILL ALSO BEGIN TO SHIFT TO THE S/SW OVERNIGHT AS A COLD FRONT APPROACHES FROM THE NW. //ATL CONFIDENCE...12Z UPDATE... MEDIUM CONFIDENCE ALL ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 55 49 72 54 / 60 50 40 70 ATLANTA 60 55 70 45 / 60 40 50 70 BLAIRSVILLE 54 47 62 42 / 70 70 70 70 CARTERSVILLE 55 52 69 40 / 60 50 60 70 COLUMBUS 75 60 75 54 / 30 20 30 60 GAINESVILLE 51 47 67 47 / 60 50 50 70 MACON 67 58 77 59 / 30 20 20 50 ROME 58 53 68 37 / 60 60 70 70 PEACHTREE CITY 63 56 71 48 / 50 30 40 70 VIDALIA 69 62 79 62 / 30 20 10 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
623 AM EST TUE MAR 3 2015 .PREV DISCUSSION... /ISSUED 315 AM EST TUE MAR 3 2015/ SHORT TERM /TODAY THROUGH WEDNESDAY/... WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK FRONT. RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT APPROACHES FROM THE NW. THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE. WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE METRO AREA. NLISTEMAA LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES. LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW. 20 && .AVIATION... 12Z UPDATE... OLD FRONTAL BOUNDARY SITUATED ACROSS SOUTH GA THIS MORNING. THE BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. WEDGING HAS STARTED TO BUILD IN ACROSS THE NE PORTION OF THE STATE AS THE EASTERLY WINDS HAVE BECOME ESTABLISHED. REGIONAL RADAR SHOWS SOME PATCHY LIGHT RAIN/HEAVY DRIZZLE MAKING ITS WAY ACROSS THE NORTHERN TERMINAL SITES...IN ASSOCIATION WITH A PASSING SHORTWAVE. LOW CIGS SHOULD CONTINUE FOR MUCH OF THE DAY...HOWEVER A BRIEF PERIOD OF MVFR IS POSSIBLE DURING THE LATE AFTERNOON. IFR EXPECTED AGAIN OVERNIGHT. EAST WINDS WILL ALSO BEGIN TO SHIFT TO THE S/SW OVERNIGHT AS A COLD FRONT APPROACHES FROM THE NW. //ATL CONFIDENCE...12Z UPDATE... MEDIUM CONFIDENCE ALL ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 51 49 72 54 / 60 50 40 70 ATLANTA 59 55 70 45 / 60 40 50 70 BLAIRSVILLE 49 47 62 42 / 70 70 70 70 CARTERSVILLE 54 52 69 40 / 60 50 60 70 COLUMBUS 74 60 75 54 / 30 20 30 60 GAINESVILLE 49 47 67 47 / 60 50 50 70 MACON 66 58 77 59 / 30 20 20 50 ROME 57 53 68 37 / 60 60 70 70 PEACHTREE CITY 62 56 71 48 / 50 30 40 70 VIDALIA 68 62 79 62 / 30 20 10 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
315 AM EST TUE MAR 3 2015 .SHORT TERM /TODAY THROUGH WEDNESDAY/... WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK FRONT. RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT APPROACHES FROM THE NW. THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE. WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE METRO AREA. NLISTEMAA .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES. LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW. 20 && AVIATION... 06Z UPDATE... OLD FRONTAL BOUNDARY SITUATED ACROSS CENTRAL GA THIS MORNING. THE BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. NORTH OF THE BOUNDARY...WEDGING TRIES TO BUILD IN...SO LOW CLOUDS AND PATCHY DRIZZLE WILL BE THE RULE FOR THE NORTHERN TAFS TODAY. THE LATEST RUN OF THE HRRR DOES BRING A PATCH OF PRECIP ACROSS ATL BETWEEN 11Z AND 16Z...SO TRIED TO TIME THIS WITH A TEMPO GROUP. CIGS MAY TRY AND LIFT TO MVFR LATE THIS AFTERNOON...BUT ARE EXPECTED TO GO IFR AFTER DARK AGAIN. MORE ORGANIZED PRECIP ANTICIPATED ON WEDNESDAY WITH A FROPA. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE ALL ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 51 49 72 54 / 60 50 40 70 ATLANTA 59 55 70 45 / 60 40 50 70 BLAIRSVILLE 49 47 62 42 / 70 70 70 70 CARTERSVILLE 54 52 69 40 / 60 50 60 70 COLUMBUS 74 60 75 54 / 30 20 30 60 GAINESVILLE 49 47 67 47 / 60 50 50 70 MACON 66 58 77 59 / 30 20 20 50 ROME 57 53 68 37 / 60 60 70 70 PEACHTREE CITY 62 56 71 48 / 50 30 40 70 VIDALIA 68 62 79 62 / 30 20 10 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...NLISTEMAA LONG TERM....20 AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1259 AM EST TUE MAR 3 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL STALL JUST TO OUR SOUTH AND WEST TONIGHT THROUGH TUESDAY. THE FRONT WILL SHIFT BACK THROUGH LATE TUESDAY NIGHT OR EARLY WEDNESDAY AS A WARM FRONT. A COLD FRONT WILL COME THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE INTO THE REGION FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... CURRENT SURFACE ANALYSIS REVEALS THAT THE FRONTAL BOUNDARY HAS DROPPED SOUTH OF THE FORECAST AREA WITH SURFACE WINDS BECOMING NORTHEASTERLY IN THE WAKE OF THE FRONT. THE BOUNDARY WILL STALL TO OUR SOUTH AND WEST TONIGHT. DEWPOINTS REMAIN IN THE 50S AT MOST LOCATIONS ACROSS THE FORECAST AREA BUT A STRONG GRADIENT IN DEWPOINTS EXISTS TO OUR NORTH AND WEST. REGIONAL RADAR COMPOSITE SHOWS A FEW LIGHT SHOWERS FINALLY REACHING THE CSRA AND WESTERN MIDLANDS DUE TO ISENTROPIC LIFT AHEAD OF SOME UPPER ENERGY. EXPECT PRECIPITATION COVERAGE TO INCREASE TOWARD DAYBREAK TUESDAY WHICH IS CONSISTENT WITH LATEST HRRR AND LAMP POP TRENDS. OVERNIGHT LOWS RANGING FROM AROUND 40 NORTH TO THE LOWER 50S EXTREME SOUTH. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... COLD FRONT WILL BE SITUATED JUST TO THE SOUTH OF THE CWA TUESDAY MORNING...BUT WILL BEGIN TO SLOWLY LIFT NORTHWARD LATE IN THE DAY AND INTO TUESDAY NIGHT. MODELS SUGGESTING THE BEST CHANCE FOR RAIN WITH ISENTROPIC LIFT MAY BE DURING THE MORNING HOURS ACROSS THE MAJORITY OF THE CWA...THEN THE BEST CHANCES FOR RAINFALL MOVE NORTH AND WEST DURING THE AFTERNOON HOURS ON TUESDAY. WITH THE SLOW NORTHWARD PROGRESSION OF THE WARM FRONT...TEMPERATURES THROUGH THE DAY TUESDAY WILL BE BACK BELOW NORMAL. TEMPERATURES ARE EXPECTED TO BE ON THE INCREASE TUESDAY NIGHT AS THE WARM FRONT MOVES THROUGH THE AREA...WITH A WARM DAY...HIGHS BACK IN THE 70S...LOOKING ON TAP FOR WEDNESDAY. BEST CHANCE FOR RAIN SHOULD STILL REMAIN OFF TO THE NORTH AND WEST THROUGH THE DAY WEDNESDAY. BETTER RAIN CHANCES WILL INCREASE WEDNESDAY NIGHT AHEAD OF THE NEXT APPROACHING COLD FRONT...ESPECIALLY ACROSS THE WESTERN COUNTIES LATE WEDNESDAY NIGHT. && .LONG TERM /THURSDAY THROUGH MONDAY/... COLD FRONT POISED TO MOVE THROUGH THE CWA DURING THE DAY THURSDAY. MAY SEE HIGH TEMPERATURES EARLY IN THE DAY...WITH READINGS THEN BECOMING STEADY OR FALLING INTO THE AFTERNOON. BEST CHANCE FOR RAINFALL WILL BE EARLY IN THE DAY THURSDAY AHEAD OF THE FRONT...AND SHOULD SEE SOME SHOWER OR AN ISOLATED THUNDERSTORMS. ANOTHER AREA OF COOL HIGH PRESSURE WILL BUILD OVER THE AREA BEHIND THE FRONT THURSDAY NIGHT AND FRIDAY. AT THIS POINT IT LOOKS AS IF THE FRONT WILL STALL OUT FAR ENOUGH SOUTH OF THE CWA SO THAT DRY CONDITIONS WOULD OCCUR THURSDAY NIGHT THROUGH SATURDAY MORNING. AFTER THAT...MOISTURE WILL BEGIN INCREASING FROM THE SOUTH...ALTHOUGH DO NOT EXPECT MORE THAN SLIGHT CHANCE FOR RAINFALL ACROSS SOUTHERN COUNTIES. LATER ON IN THE LONGER TERM...CONFIDENCE IS LOW DUE TO DISAGREEMENTS BETWEEN THE GFS AND THE ECMWF. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... SURFACE HIGH PRESSURE HAS BEGUN RIDGING INTO THE AREA FROM THE NORTH WITH LIGHT EAST-NORTHEASTERLY FLOW. INCREASING SOUTHWESTERLY FLOW ALOFT ATOP THE NORTHEASTERLY SURFACE FLOW IS GOING TO RESULT IN THE DEVELOPMENT OF ANOTHER WEDGE WITH LOWERING CEILINGS AND LIGHT RAIN DEVELOPING. VFR CEILINGS TO START THE PERIOD ARE EXPECTED TO DROP TO MVFR BY 08Z AND EVENTUALLY TO IFR BY AROUND 12Z AND REMAIN RESTRICTED THROUGH MUCH OF THE REMAINDER OF THE FORECAST PERIOD. LIGHT RAIN AND LOWERING VISIBILITIES TO IFR ARE EXPECTED BY 15Z ALL TERMINALS...THOUGH LOWER CONFIDENCE AT AGS/DNL/OGB AS IT COULD OCCUR A LITTLE LATER THERE. CONDITIONS WILL REMAIN DETERIORATED THIS AFTERNOON AND TONIGHT AS THE STALL FRONT TO THE SOUTH BEGINS TO LIFT NORTHWARD AS A WARM FRONT AND CEILINGS AND VISIBILITIES DROP FURTHER TO LIFR WITH SOME DENSE FOG POSSIBLE BY THE END OF THE FORECAST PERIOD. STRENGTHENING FLOW ABOVE THE SURFACE LIKELY WILL RESULT IN LOW LEVEL WIND SHEAR AND WILL INCLUDE IN THE FORECAST. EXTENDED AVIATION OUTLOOK...WIDESPREAD IFR OR MVFR CONDITIONS ARE EXPECTED DURING THE REST OF TUESDAY NIGHT AND EARLY WEDNESDAY AND ALSO ON THURSDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1245 AM EST TUE MAR 3 2015 .PREV DISCUSSION... /ISSUED 1048 PM EST MON MAR 2 2015/ EVENING UPDATE... CURRENT FORECAST LOOKS ON TRACK... SO NO SIGNIFICANT CHANGES ARE NEEDED AT THIS TIME. /39 SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... /ISSUED AT 259 PM EST MON MAR 2 2015/ SHORT TERM BEGINS WITH WEAK ZONAL FLOW ALOFT GIVING WAY TO WEAK RIDGING AS AN AREA OF SURFACE HIGH PRESSURE CROSSES THE APPALACHIANS AND RIDGES DOWN THE EASTERN SEABOARD IN A HYBRID DAMMING EVENT. MOISTURE CONTINUES TO OVERSPREAD THE AREA BRINGING A CHANCE OF RAIN TO MAINLY NORTH GEORGIA...BUT HAVE CONTINUED TREND OF AT LEAST SLIGHT CHANCE POPS ACROSS THE AREA. ZERO SBCAPE TO SPEAK OF TOMORROW BUT SOME LOW-LEVEL MUCAPE /LESS THAN 100 J/KG/ SHOWS UP IN PORTIONS OR NORTH GEORGIA ESPECIALLY ON THE NAM...WHICH OF COURSE TENDS TO BE ON THE HIGH SIDE ANYWAY. SPC DAY2 OUTLOOK DOES NOT HAVE EVEN GENERAL THUNDER NOSING INTO GEORGIA SO WHILE AN ISOLATED RUMBLE CANNOT BE TOTALLY RULED OUT...JUST NOT ENOUGH CONFIDENCE TO KEEP THUNDER CHANCES IN AT THIS TIME. TEMPERATURES TODAY HAVE RISEN QUITE A BIT HIGHER THAN ANTICIPATED WITH CLEARING SKIES WHICH MAY VERY WELL HAVE IMPLICATIONS ON LOWS TONIGHT AS MOISTURE FILLS BACK IN AND CLOUD COVER INCREASES...AND THUS TRENDED A TAD LOWER WITH OVERNIGHT LOWS. HIGHS TOMORROW NEAR SEASONAL FOR THE SOUTHWEST HALF OF THE AREA BUT WITH THE DAMMING BUILDING IN THERE SHOULD NOT BE MUCH OF A DIURNAL CURVE ACROSS ESPECIALLY NORTHEAST GEORGIA...AND AS IT IS CURRENT FORECAST HIGHS MAY BE A LITTLE TOO WARM IN THOSE AREAS. FOLLOWING THAT...LOWS TOMORROW NIGHT WILL HAVE TO BE REEVALUATED DEPENDING ON THE STRENGTH OF THE DAMMING AND HOW MUCH PRECIPITATION HAS INFLUENCED THE COLD DOME. HIGH CHANCE TO LIKELY POPS REMAIN ACROSS NORTH GEORGIA THROUGH THE END OF THE PERIOD THOUGH BY WEDNESDAY MORNING EXPECT VERY LITTLE IF ANY RAIN ACROSS THE REST OF THE AREA. TDP LONG TERM /WEDNESDAY THROUGH MONDAY/... /ISSUED AT 259 PM EST MON MAR 2 2015/ HAVE LEFT THE LONG TERM ESSENTIALLY AS IS. POTENTIAL WINTER WEATHER EVENT FOR WEDNESDAY NIGHT THURSDAY MORNING DEPENDS ON SEVERAL FACTORS...HOW FAR SOUTH THE COLD AIR GETS SEEMS TO BE THE MAIN UNCERTAINTY. UPPER FLOW REMAINS SOUTHWEST AND IT MAY BE HARD FOR THE FREEZING TEMPERATURES TO GET TOO FAR SOUTH INTO THE STATE. THICKNESS PROFILES SHOW A POSSIBILITY OF RAIN...FREEZING RAIN AND SLEET WITH SOME SNOW INTO THURSDAY MORNING. THIS WILL BE MONITORED IN UPCOMING MODEL RUNS. REMAINDER OF FORECAST LOOKS OKAY BUT THERE IS MORE UNCERTAINTY TOWARD THE END OF THE PERIOD WITH GFS AND ECMWF SHOWING DIFFERING UPPER AIR PATTERNS. HAVE ONLY TWEAKED THE LAST COUPLE OF PERIODS. PREVIOUS DISCUSSION IS INCLUDED BELOW. 41 PREVIOUS LONG TERM.../ISSUED AT 344 AM EST MON MAR 2 2015/ LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MEDIUM RANGE MODELS REMAIN CONSISTENT AND IN RELATIVELY GOOD AGREEMENT THROUGH THE MAJORITY OF THE EXTENDED FORECAST PERIOD. STILL SHOWING THE WORK WEEK DOMINATED BY SOUTHWESTERLY UPPER FLOW AHEAD OF THE DEEP WESTERN U.S. TROUGH. THIS KEEPS THE REGION IN A FAIRLY WARM PATTERN UNTIL THURSDAY BEHIND THE SHARP SURFACE FRONT THE SWEEPS THROUGH WEDNESDAY/WEDNESDAY NIGHT. STILL SEEING ENOUGH INSTABILITY FOR CHANCE COVERAGE OF THUNDERSTORMS WEDNESDAY. STRONG LOW/MID-LEVEL WINDS ALSO STILL HAVE ME A BIT CONCERNED ABOUT AT LEAST ISOLATED SEVERE THUNDERSTORM POTENTIAL. GOOD LOW-LEVEL FORCING AHEAD OF THE FRONT BUT UPPER SUPPORT IS LACKING WITH THE MAIN UPPER TROUGH/SHORT WAVE LAGGING FAR BEHIND THE FRONT. GFS AND ECMWF ALSO STILL INSIST ON BRINGING IN MUCH COLDER AIR AS EARLY AS LATE WEDNESDAY NIGHT WITH RESIDUAL MOISTURE AND THE INFLUENCE OF THE UPPER SYSTEM SQUEEZING OUT SOME LOW QPF PRECIPITATION. UPPER FLOW REMAINS SOUTHWESTERLY THROUGH THURSDAY AND LOWEST THICKNESSES REMAIN WELL NORTH OF THE STATE. WILL NEED TO WATCH TRENDS FOR THE POSSIBILITY OF SOME WINTRY MIX ACROSS THE NORTH. GFS AND ECMWF BOTH SHOW A GOOD TEMPERATURE RECOVERY INTO THE WEEKEND AFTER A THE SHOT OF COOL AIR THURSDAY THROUGH FRIDAY MORNING AS THE UPPER FLOW REMAINS GENERALLY ZONAL OVER THE SOUTHEASTERN U.S. AND THE HEART OF THE COLDEST AIR REMAINS WELL NORTH OF THE STATE. MAINLY DRY AS WELL...HOWEVER BOTH MODELS SHOW SOME PRECIPITATION POSSIBLY SURGING NORTH INTO CENTRAL GEORGIA SATURDAY AS SURFACE LOW PRESSURE SPINS UP OFF THE GEORGIA/CAROLINA COAST. NOT REAL CONFIDENT WE WILL SEE ANYTHING SIGNIFICANT WITH THIS BUT SLIGHT CHANCE OR LOW CHANCE POPS MAY BE APPROPRIATE. 20 && .AVIATION... 06Z UPDATE... OLD FRONTAL BOUNDARY SITUATED ACROSS CENTRAL GA THIS MORNING. THE BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. NORTH OF THE BOUNDARY...WEDGING TRIES TO BUILD IN...SO LOW CLOUDS AND PATCHY DRIZZLE WILL BE THE RULE FOR THE NORTHERN TAFS TODAY. THE LATEST RUN OF THE HRRR DOES BRING A PATCH OF PRECIP ACROSS ATL BETWEEN 11Z AND 16Z...SO TRIED TO TIME THIS WITH A TEMPO GROUP. CIGS MAY TRY AND LIFT TO MVFR LATE THIS AFTERNOON...BUT ARE EXPECTED TO GO IFR AFTER DARK AGAIN. MORE ORGANIZED PRECIP ANTICIPATED ON WEDNESDAY WITH A FROPA. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE ALL ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 49 48 71 46 / 60 50 70 80 ATLANTA 58 54 69 39 / 60 40 70 80 BLAIRSVILLE 51 48 61 35 / 70 70 80 80 CARTERSVILLE 56 53 67 35 / 60 50 80 80 COLUMBUS 72 58 74 52 / 30 20 70 80 GAINESVILLE 49 46 66 40 / 60 50 80 80 MACON 67 56 76 53 / 30 20 60 80 ROME 58 54 64 33 / 60 60 80 80 PEACHTREE CITY 63 55 71 42 / 50 30 70 80 VIDALIA 67 59 81 61 / 30 20 30 50 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
355 PM CST TUE MAR 3 2015 .SHORT TERM... 247 PM CST THROUGH THURSDAY... SOMEWHAT BAGGY COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING AND USHER IN PROGRESSIVELY COLDER AIR MASS THROUGH THE NIGHT. AHEAD OF THE INTO THE EARLY-MID EVENING ANTICIPATE LOW STRATUS HANGING AROUND AND LIKELY RESULTING IN NEARLY STEADY TEMPS AND HAVE GONE A BIT ABOVE HOURLY GUIDANCE TEMPS HANGING ONTO 30S INTO THE EARLY EVENING OVER MOST OF THE CWA BEFORE BOTTOM DROPS OUT LATE TONIGHT. SOME PARTIAL CLEARING IS EXPECTED OVERNIGHT BUT SOME MID-HIGH CLOUDS WILL MOVE IN AS WELL...SO NOT CURRENTLY EXPECTING SKIES TO GO CLEAR. A COUPLE DAYS OF UNSEASONABLY COLD WEATHER LOOK TO BE ON TAP WEDNESDAY AND THURSDAY. WEDNESDAY NIGHT HAS POTENTIAL TO GIVE CHICAGO`S RECORD LOW A RUN FOR ITS MONEY...THOUGH GUIDANCE SUGGESTS MID-HIGH LEVEL CLOUDINESS COULD BE RATHER EXTENSIVE FOR MUCH OF THE NIGHT AND WINDS STAYING UP A BIT. BOTH OF THESE FACTORS COULD KEEP TEMPS FROM REALIZING THEIR FULL FRIGID POTENTIAL...THOUGH ANY LATE NIGHT CLEARING COULD ALLOW FOR LAST MINUTE DROPS IN TEMPS. ARCTIC HIGH WILL BE NEAR BY THURSDAY WITH HEART OF THE ARCTIC AIR MASS OVERHEAD TO START THE DAY...SUGGESTING THAT HIGHS COULD THREATEN RECORD LOW MAX TEMPS. FULL SUNSHINE THURSDAY WITH LOWER ALBEDO IN CHICAGO AND RFD METRO AREAS SHOULD ALLOW TEMPS TO MODERATE A BIT ABOVE GUIDANCE AND HAVE TRENDED HIGHS EVER SO SLIGHTLY UPWARD. IZZI && .LONG TERM... 247 PM CST THURSDAY NIGHT THROUGH TUESDAY... THURSDAY NIGHT COULD BE ONE OF THOSE NIGHTS THAT SEE TEMPERATURES CRASH DURING THE EVENING HOURS GIVEN CLEAR SKIES AND PROXIMITY OF THE HIGH. HIGH DOES SCOOT OFF TO THE EAST OVERNIGHT AND SOUTHERLY WINDS LOOK TO DEVELOP AFTER MIDNIGHT WHICH SHOULD ALLOW TEMPS TO LEVEL OFF AND THEN BEGIN TO SLOWLY RISE PRIOR TO SUNRISE AND DID REFLECT THIS TREND IN THE HOURLY TEMP GRIDS. FRIDAY INTO NEXT WEEK LOOK TO BE FAIRLY QUIET PERIOD WITH A TREND TO NORMAL AND THEN POTENTIALLY EVEN ABOVE NORMAL TEMPS BY EARLY NEXT WEEK. STRONG MARCH SUN AND TEMPS WARMING ABOVE FREEZING THIS WEEKEND DURING THE DAYTIME SHOULD BEGIN THE PROCESS OF CHIPPING AWAY AT THE DEEP SNOW PACK/GLACIER THAT HAS BLANKETED THE REGION SINCE THE EARLY FEBRUARY BLIZZARD. MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST AN EXTENDED PERIOD OF ABOVE AVERAGE TEMPERATURES HEADING INTO THE MIDDLE OF THE MONTH...THE QUICKER THE SNOW PACK MELTS THE WARMER TEMPS COULD POTENTIALLY GET AS A MEAN RIDGE IS PROGGED TO DEVELOP OF THE NATION`S MID SECTION. IZZI && .CLIMATE... WE COULD COME CLOSE TO A COUPLE RECORDS WITH THIS NEXT COLD SPELL. THE ONES WITH STARS (*) ARE MOST VULNERABLE. WED 3/4 THU 3/5 ROCKFORD RECORD LOW-11 (2002)-11 (2002) RECORD LOW MAX 14 (2002)* 17 (1960)* CHICAGO RECORD LOW-12 (1873) 0 (1978)* RECORD LOW MAX 17 (1890) 12 (1901) && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * MVFR CIGS EXPECTED THROUGH THE NIGHT BCMG VFR WEDNESDAY MORNING. * WEST WINDS GUSTING TO 22 KT THIS AFTN. * NW WINDS GUSTING TO 25 KT WEDNESDAY. JEE //DISCUSSION...UPDATED 18Z... WARM...MOIST ADVECTION HAS SET UP ACROSS THE REGION IN ADVANCE OF A STRONG COLD FRONT EXTENDING FROM NERN MN THROUGH CNTRL IOWA. CIGS HAVE BECOME MORE UNIFORMLY 005-007 ACROSS THE REGION AS TEMPERATURES RISE INTO THE LOWER TO MIDDLE 30S AND DEW POINTS RISE INTO THE UPPER 20S TO LOWER 30S. DRY AIR OVERSPREADING THE NEARLY SATURATED LOWER LEVELS HAS TRANSITIONED PCPN OVER TO DZ WHERE SFC TEMPS ARE ABOVE FREEZING AND FZDZ WHERE TEMPS REMAIN BELOW FREEZING. A FEW ISOLD POCKETS OF MORE STEADY RAIN REMAIN...BUT SHOULD BE BRIEF. EXPECT THAT MDW/GYY HAVE ALREADY TRANSITIONED OVER TO DZ...WHILE ORD/DPA/RFD REMAIN UNDER FZDZ. A SFC WAVE ALONG THE FRONT IS QUICKLY TRACKING NEWD ALONG THE FRONT AND HAS ALREADY MOVED INTO WISCONSIN...WITH A 7MB/3HR PRESSURE RISE/FALL COUPLET GENERATING WIND GUSTS TO 25KT ACROSS THE REGION. EXPECT THE DZ TO END AS THE SFC LOW CONTINUES NEWD INTO THE UPPER GREAT LAKES...WITH LATEST RADAR IMAGERY SHOWING A RELATIVELY SHARP BACK EDGE TO THE PCPN MOVING EWD THROUGH NCNTRL IL. CONDITIONS SHOULD GRADUALLY IMPROVE TO MVFR AND VFR FOLLOWING THE FROPA AS COLDER...DRIER AIR FILTERS ACROSS THE REGION. FOLLOWING THE FROPA...EXPECT THAT STRONG ADVECTION BEHIND THE FRONT WILL HELP DRIVE NWLY GUSTS TO 25KT TOMORROW. KREIN //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM-HIGH CONFIDENCE IN WHEN CIGS IMPROVE TO VFR. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT THROUGH FRIDAY...VFR. SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE. RATZER && .MARINE... 230 PM...LOW PRESSURE OVER THE NORTHERN LAKES WILL MERGE WITH DEEPER LOW PRESSURE OVER NORTHERN ONTARIO TONIGHT AND THEN MOVE INTO QUEBEC WEDNESDAY MORNING. WINDS WILL BE SHIFTING WESTERLY OVER THE NEXT FEW HOURS AND THEN MORE NORTHWEST ACROSS THE SOUTHERN PART OF THE LAKE OVERNIGHT. THE GRADIENT WILL REMAIN TIGHT AS HIGH PRESSURE BUILDS ACROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY AND WEDNESDAY NIGHT AND COMBINED WITH RETURNING COLD AIR...WINDS TO 30KT LOOKS REASONABLE. AS THE HIGH MOVES EAST ACROSS THE SOUTHERN LAKES AND OHIO VALLEY THURSDAY NIGHT INTO FRIDAY...THE GRADIENT WILL TIGHTEN ACROSS THE WESTERN LAKES WITH SOUTHWEST WINDS INCREASING BACK TO 30KT WITH SOME POTENTIAL FOR LOW END GALES. THESE WINDS WILL GRADUALLY DIMINISH FRIDAY NIGHT AS THE GRADIENT BEGINS TO WEAKEN. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 331 PM CST Tue Mar 3 2015 .SHORT TERM...(Tonight) ISSUED AT 330 PM CST TUE MAR 3 2015 Freezing rain and sleet developed over western Illinois around midnight and quickly tracked east over all but extreme southeast Illinois by 08z/2am. Already seeing the backedge of our second band of wintry precip entering west central Illinois, so it appears we will have a brief lull in the freezing rain and sleet. However, the latest HRRR suggests another band of rain, freezing rain and sleet will move northeast across our area at or just after dawn Rainfall rates have not been much with these quick moving bands of freezing rain/sleet with most areas seeing less than 0.05" per hour, but certainly enough for some light icing to occur on bridge decks and overpasses and on lesser traveled roads. RAP forecast soundings continue to suggest temperatures will rise above the freezing mark over southeast Illinois by dawn...central sections of the forecast area by 900 am...and between 10 am and Noon roughly along and north of the Interstate 74 corridor. By late morning into the afternoon hours the stronger lift associated with the low level warm advection/ isentropic ascent shifts off to our east and southeast with a gradual lowering of POPs warranted from northwest to southeast. Best 850-700 forcing edges into southeast IL by mid to late afternoon where our highest POPs will be located. Guidance temperatures look reasonable for this afternoon with highs ranging from the upper 30s far north to the upper 40s far southeast. && .LONG TERM...(Wednesday through Tuesday) ISSUED AT 330 PM CST TUE MAR 3 2015 The cold front currently passing through the forecast area will stall out south of the Ohio River Valley early Wednesday as it becomes parallel to the upper-level flow. A 180+ kt jet streak will be in our vicinity on the cool side of this front/low level baroclinic zone for much of the day Wednesday. A very small portion of our forecast area south of I-70 will be at least nicked by the good frontogenetical forcing/jet dynamics in this flow regime. With this in mind it is looking like 2-4 inches of snow will fall late tonight through Wednesday evening across at least Clay, Richland, and Lawrence counties. There is some model disagreement on where the axis of heavier snow will set up, and the snow totals may need to be boosted a little and pushed further north or decreased and pulled further south depending on future model runs. The snow threat in southeast IL diminishes later Wednesday night, as the current system finally pulls away, and another Arctic high (hopefully the last of the winter) builds into the entire forecast area. This high will be accompanied by a couple nights of mainly single digit lows Wednesday night and Thursday night, and highs mainly in the teens for Thursday. Temperatures are still expected to gradually moderate beginning Friday and continuing into next week. High temperatures may actually be above normal for a change by early next week, with highs in the 50s possible by next Tuesday. The models do not suggest the passage of any significant system from Thursday-Tuesday, so predominantly dry weather looks to be the rule through the period. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 1157 AM CST TUE MAR 3 2015 Mainly LIFR cigs/IFR vsbys in fog and -dz/-ra across central IL late this morning. Conditions expected to remain steady for a few more hours before gradual lifting of ceilings during afternoon as a cold front and drier air approach from the NW. Gradual improvement to continue from 20Z through 06Z before MVFR ceilings dissipate to scattered cloud cover. Winds S-SW 15-20 kts with higher gusts through early afternoon, gradually shifting to NW through evening and decreasing to 10-15 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY from 6 AM to 6 PM CST Wednesday FOR ILZ071>073. && $$ SHORT TERM...Onton LONG TERM...Bak AVIATION...Onton
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
151 PM CST TUE MAR 3 2015 .UPDATE... 1022 AM CST THE MORE SIGNIFICANT PRECIP IS MOVING OFF TO THE EAST AND SHOULD SEE PRECIP TAPER TO DRIZZLE/FREEZING DRIZZLE WITH JUST SOME INTERMITTENT LIGHT RAIN OR FREEZING RAIN INTO THE EARLY AFTERNOON. TEMPERATURES SHOULD CONTINUE TO INCH UPWARD AND CLIMB ABOVE FREEZING ACROSS THE AREA IN THE NEXT COUPLE HOURS. IT IS POSSIBLE THAT WINTER WX ADVISORY COULD NEED TO BE EXTENDED A COUPLE OF HOURS OVER NORTHERN PORTIONS OF THE CWA...WILL CONTINUE TO MONITOR TEMP TRENDS AND MAKE A LAST MINUTE DECISION ON THAT. IZZI && .SHORT TERM... 300 AM CST THROUGH WEDNESDAY... MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING. SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE BEFORE ENDING ALTOGETHER THIS EVENING. HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER DEUBELBEISS && .LONG TERM... 300 AM CST WEDNESDAY NIGHT THROUGH MONDAY... FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING. FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT DOESNT COME THROUGH DRY. DEUBELBEISS && .CLIMATE... A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN JEOPARDY ON WEDNESDAY AND THURSDAY. HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO THEM. WED 3/4 THU 3/5 ROCKFORD RECORD LOW-11 (2002)-11 (2002) RECORD LOW MAX 14 (2002)* 17 (1960)* CHICAGO RECORD LOW-12 (1873) 0 (1978)* RECORD LOW MAX 17 (1890)* 12 (1901) KMD/KJB/BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WSWLY WINDS GUSTING TO 20-25KT UNTIL FROPA EARLY THIS EVENING...THEN WIND SHIFTING TO WNWLY OVERNIGHT AND NWLY TOMORROW GUSTING TO 20KT. * IFR VIS IN -DZ/BR FOR A COUPLE MORE HOURS...IMPROVING TO MVFR IN BR UNTIL FROPA. * IFR CIGS UNTIL FROPA...THEN IMPROVING TO MVFR OVERNIGHT INTO EARLY TOMORROW MORNING. KREIN //DISCUSSION...UPDATED 18Z... WARM...MOIST ADVECTION HAS SET UP ACROSS THE REGION IN ADVANCE OF A STRONG COLD FRONT EXTENDING FROM NERN MN THROUGH CNTRL IOWA. CIGS HAVE BECOME MORE UNIFORMLY 005-007 ACROSS THE REGION AS TEMPERATURES RISE INTO THE LOWER TO MIDDLE 30S AND DEWPOINTS RISE INTO THE UPPER 20S TO LOWER 30S. DRY AIR OVERSPREADING THE NEARLY SATURATED LOWER LEVELS HAS TRANSITIONED PCPN OVER TO DZ WHERE SFC TEMPS ARE ABOVE FREEZING AND FZDZ WHERE TEMPS REMAIN BELOW FREEZING. A FEW ISOLD POCKETS OF MORE STEADY RAIN REMAIN...BUT SHOULD BE BRIEF. EXPECT THAT MDW/GYY HAVE ALREADY TRANSITIONED OVER TO DZ...WHILE ORD/DPA/RFD REMAIN UNDER FZDZ. A SFC WAVE ALONG THE FRONT IS QUICKLY TRACKING NEWD ALONG THE FRONT AND HAS ALREADY MOVED INTO WISCONSIN...WITH A 7MB/3HR PRESSURE RISE/FALL COUPLET GENERATING WIND GUSTS TO 25KT ACROSS THE REGION. EXPECT THE DZ TO END AS THE SFC LOW CONTINUES NEWD INTO THE UPPER GREAT LAKES...WITH LATEST RADAR IMAGERY SHOWING A RELATIVELY SHARP BACK EDGE TO THE PCPN MOVING EWD THROUGH NCNTRL IL. CONDITIONS SHOULD GRADUALLY IMPROVE TO MVFR AND VFR FOLLOWING THE FROPA AS COLDER...DRIER AIR FILTERS ACROSS THE REGION. FOLLOWING THE FROPA...EXPECT THAT STRONG ADVECTION BEHIND THE FRONT WILL HELP DRIVE NWLY GUSTS TO 25KT TOMORROW. KREIN //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN TIMING PCPN ENDING. * LOW CONFIDENCE IN TIMING OF CIGS/VIS IMPROVING TO MVFR AND VFR. * HIGH CONFIDENCE IN WIND TRENDS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT THROUGH FRIDAY...VFR. SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE. RATZER && .MARINE... 214 AM CST MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS TO RELAX A BIT AND SHIFT TO THE WEST. SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS. RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR TO HAVE A FAIR AMOUNT OF OPEN WATER. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1157 AM CST Tue Mar 3 2015 .UPDATE... ISSUED AT 1044 AM CST TUE MAR 3 2015 Temperatures have risen above 32 degrees at all sites with an immediate threat for precipitation this morning, with all sites expected above freezing in the next hour, therefore the winter weather advisory has been allowed to expire. Temperatures expected to continue to rise to the upper 30s to mid 40s this afternoon as central Illinois remains in the warm sector of the current system. Winds breezy S-SW 10-20 mph with dewpoints well into the 30s will help melt the light ice accumulations off. Scattered light showers continue to stream into the area from the southwest and this will continue until after a cold front moves in from the northwest later this afternoon and evening. && .SHORT TERM...(Today) ISSUED AT 244 AM CST TUE MAR 3 2015 Freezing rain and sleet developed over western Illinois around midnight and quickly tracked east over all but extreme southeast Illinois by 08z/2am. Already seeing the back edge of our second band of wintry precip entering west central Illinois, so it appears we will have a brief lull in the freezing rain and sleet. However, the latest HRRR suggests another band of rain, freezing rain and sleet will move northeast across our area at or just after dawn. Rainfall rates have not been much with these quick moving bands of freezing rain/sleet with most areas seeing less than 0.05" per hour, but certainly enough for some light icing to occur on bridge decks and overpasses and on lesser traveled roads. RAP forecast soundings continue to suggest temperatures will rise above the freezing mark over southeast Illinois by dawn...central sections of the forecast area by 900 am...and between 10 am and Noon roughly along and north of the Interstate 74 corridor. By late morning into the afternoon hours the stronger lift associated with the low level warm advection/ isentropic ascent shifts off to our east and southeast with a gradual lowering of POPs warranted from northwest to southeast. Best 850-700 forcing edges into southeast IL by mid to late afternoon where our highest POPs will be located. Guidance temperatures look reasonable for this afternoon with highs ranging from the upper 30s far north to the upper 40s far southeast. && .LONG TERM...(Tonight through Monday) ISSUED AT 244 AM CST TUE MAR 3 2015 Current system will not fully clear our area until Thursday, as the trailing end of the cold front becomes parallel to the upper flow over the Ohio Valley. Most of the evening models keep the threat for precipitation from about I-70 southward, although the NAM has a secondary surge on Wednesday afternoon all the way up to about I-72. Leaning more toward the ECMWF/GFS blend for PoP`s tonight and Wednesday. Lingering precip north of I-70 should end this evening, but kept higher PoP`s all night into Wednesday. This evening, most areas will see the precipitation switch briefly to snow before ending, with little accumulation. While the transition to snow south of I-70 occurs late tonight, temperatures will be supportive of all snow through Wednesday. Greatest snow amounts expected near the Ohio Valley, but currently think that 1 to 3 inches in southeast Illinois is likely. Light snow will linger into Wednesday night before ending late. The other feature of note is what hopefully will be the last Arctic blast of the winter. Digging upper trough currently coming into Manitoba will spread a chunk of unseasonably cold air over much of the Midwest Wednesday and Thursday, with 850 mb temperatures down into the -18C range by Thursday morning. Highs both days will struggle to get out of the teens in some areas -- normal highs are well into the 40s by now -- and lows Thursday morning should be a few degrees either side of zero. Current indications are that a wind chill advisory would be needed across the northern CWA Wednesday night and early Thursday, as the system to our south keeps the winds up and slows the arrival of high pressure. Heading into the weekend and early next week, 40s should become more widespread, and the latest 8-14 day outlook introduces a foreign concept called "above normal temperatures". && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 1157 AM CST TUE MAR 3 2015 Mainly LIFR cigs/IFR vsbys in fog and -dz/-ra across central IL late this morning. Conditions expected to remain steady for a few more hours before gradual lifting of ceilings during afternoon as a cold front and drier air approach from the NW. Gradual improvement to continue from 20Z through 06Z before MVFR ceilings dissipate to scattered cloud cover. Winds S-SW 15-20 kts with higher gusts through early afternoon, gradually shifting to NW through evening and decreasing to 10-15 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Onton SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Onton
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1153 AM CST TUE MAR 3 2015 .UPDATE... 1022 AM CST THE MORE SIGNIFICANT PRECIP IS MOVING OFF TO THE EAST AND SHOULD SEE PRECIP TAPER TO DRIZZLE/FREEZING DRIZZLE WITH JUST SOME INTERMITTENT LIGHT RAIN OR FREEZING RAIN INTO THE EARLY AFTERNOON. TEMPERATURES SHOULD CONTINUE TO INCH UPWARD AND CLIMB ABOVE FREEZING ACROSS THE AREA IN THE NEXT COUPLE HOURS. IT IS POSSIBLE THAT WINTER WX ADVISORY COULD NEED TO BE EXTENDED A COUPLE OF HOURS OVER NORTHERN PORTIONS OF THE CWA...WILL CONTINUE TO MONITOR TEMP TRENDS AND MAKE A LAST MINUTE DECISION ON THAT. IZZI && .SHORT TERM... 300 AM CST THROUGH WEDNESDAY... MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING. SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE BEFORE ENDING ALTOGETHER THIS EVENING. HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER DEUBELBEISS && .LONG TERM... 300 AM CST WEDNESDAY NIGHT THROUGH MONDAY... FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING. FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT DOESNT COME THROUGH DRY. DEUBELBEISS && .CLIMATE... A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN JEOPARDY ON WEDNESDAY AND THURSDAY. HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO THEM. WED 3/4 THU 3/5 ROCKFORD RECORD LOW-11 (2002)-11 (2002) RECORD LOW MAX 14 (2002)* 17 (1960)* CHICAGO RECORD LOW-12 (1873) 0 (1978)* RECORD LOW MAX 17 (1890)* 12 (1901) KMD/KJB/BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * FREEZING DRIZZLE CHANGING OVER TO DRIZZLE OR OCNL LIGHT RAIN AS TEMPS RISE ABOVE FREEZING. * IFR CIGS UNTIL FROPA LATE AFTERNOON/EARLY EVENING...THEN IMPROVING TO MVFR OVERNIGHT INTO EARLY TOMORROW MORNING. * SSWLY WINDS GUSTING TO 25KT...VEERING TO WLY BY EARLY EVENING... THEN VEERING NWLY AND GUSTING TO 25KT TOMORROW. KREIN //DISCUSSION...UPDATED 18Z... WARM...MOIST ADVECTION HAS SET UP ACROSS THE REGION IN ADVANCE OF A STRONG COLD FRONT EXTENDING FROM NERN MN THROUGH CNTRL IOWA. CIGS HAVE BECOME MORE UNIFORMLY 005-007 ACROSS THE REGION AS TEMPERATURES RISE INTO THE LOWER TO MIDDLE 30S AND DEWPOINTS RISE INTO THE UPPER 20S TO LOWER 30S. DRY AIR OVERSPREADING THE NEARLY SATURATED LOWER LEVELS HAS TRANSITIONED PCPN OVER TO DZ WHERE SFC TEMPS ARE ABOVE FREEZING AND FZDZ WHERE TEMPS REMAIN BELOW FREEZING. A FEW ISOLD POCKETS OF MORE STEADY RAIN REMAIN...BUT SHOULD BE BRIEF. EXPECT THAT MDW/GYY HAVE ALREADY TRANSITIONED OVER TO DZ...WHILE ORD/DPA/RFD REMAIN UNDER FZDZ. A SFC WAVE ALONG THE FRONT IS QUICKLY TRACKING NEWD ALONG THE FRONT AND HAS ALREADY MOVED INTO WISCONSIN...WITH A 7MB/3HR PRESSURE RISE/FALL COUPLET GENERATING WIND GUSTS TO 25KT ACROSS THE REGION. EXPECT THE DZ TO END AS THE SFC LOW CONTINUES NEWD INTO THE UPPER GREAT LAKES...WITH LATEST RADAR IMAGERY SHOWING A RELATIVELY SHARP BACK EDGE TO THE PCPN MOVING EWD THROUGH NCNTRL IL. CONDITIONS SHOULD GRADUALLY IMPROVE TO MVFR AND VFR FOLLOWING THE FROPA AS COLDER...DRIER AIR FILTERS ACROSS THE REGION. FOLLOWING THE FROPA...EXPECT THAT STRONG ADVECTION BEHIND THE FRONT WILL HELP DRIVE NWLY GUSTS TO 25KT TOMORROW. KREIN //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM CONFIDENCE IN TIMING PCPN ENDING. * LOW CONFIDENCE IN TIMING OF CIGS/VIS IMPROVING TO MVFR AND VFR. * HIGH CONFIDENCE IN WIND TRENDS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT THROUGH FRIDAY...VFR. SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE. RATZER && .MARINE... 214 AM CST MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS TO RELAX A BIT AND SHIFT TO THE WEST. SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS. RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR TO HAVE A FAIR AMOUNT OF OPEN WATER. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008- ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021- ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY. IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL NOON TUESDAY. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1044 AM CST Tue Mar 3 2015 .UPDATE... ISSUED AT 1044 AM CST TUE MAR 3 2015 Temperatures have risen above 32 degrees at all sites with an immediate threat for precipitation this morning, with all sites expected above freezing in the next hour, therefore the winter weather advisory has been allowed to expire. Temperatures expected to continue to rise to the upper 30s to mid 40s this afternoon as central Illinois remains in the warm sector of the current system. Winds breezy S-SW 10-20 mph with dewpoints well into the 30s will help melt the light ice accumulations off. Scattered light showers continue to stream into the area from the southwest and this will continue until after a cold front moves in from the northwest later this afternoon and evening. && .SHORT TERM...(Today) ISSUED AT 244 AM CST TUE MAR 3 2015 Freezing rain and sleet developed over western Illinois around midnight and quickly tracked east over all but extreme southeast Illinois by 08z/2am. Already seeing the back edge of our second band of wintry precip entering west central Illinois, so it appears we will have a brief lull in the freezing rain and sleet. However, the latest HRRR suggests another band of rain, freezing rain and sleet will move northeast across our area at or just after dawn. Rainfall rates have not been much with these quick moving bands of freezing rain/sleet with most areas seeing less than 0.05" per hour, but certainly enough for some light icing to occur on bridge decks and overpasses and on lesser traveled roads. RAP forecast soundings continue to suggest temperatures will rise above the freezing mark over southeast Illinois by dawn...central sections of the forecast area by 900 am...and between 10 am and Noon roughly along and north of the Interstate 74 corridor. By late morning into the afternoon hours the stronger lift associated with the low level warm advection/ isentropic ascent shifts off to our east and southeast with a gradual lowering of POPs warranted from northwest to southeast. Best 850-700 forcing edges into southeast IL by mid to late afternoon where our highest POPs will be located. Guidance temperatures look reasonable for this afternoon with highs ranging from the upper 30s far north to the upper 40s far southeast. && .LONG TERM...(Tonight through Monday) ISSUED AT 244 AM CST TUE MAR 3 2015 Current system will not fully clear our area until Thursday, as the trailing end of the cold front becomes parallel to the upper flow over the Ohio Valley. Most of the evening models keep the threat for precipitation from about I-70 southward, although the NAM has a secondary surge on Wednesday afternoon all the way up to about I-72. Leaning more toward the ECMWF/GFS blend for PoP`s tonight and Wednesday. Lingering precip north of I-70 should end this evening, but kept higher PoP`s all night into Wednesday. This evening, most areas will see the precipitation switch briefly to snow before ending, with little accumulation. While the transition to snow south of I-70 occurs late tonight, temperatures will be supportive of all snow through Wednesday. Greatest snow amounts expected near the Ohio Valley, but currently think that 1 to 3 inches in southeast Illinois is likely. Light snow will linger into Wednesday night before ending late. The other feature of note is what hopefully will be the last Arctic blast of the winter. Digging upper trough currently coming into Manitoba will spread a chunk of unseasonably cold air over much of the Midwest Wednesday and Thursday, with 850 mb temperatures down into the -18C range by Thursday morning. Highs both days will struggle to get out of the teens in some areas -- normal highs are well into the 40s by now -- and lows Thursday morning should be a few degrees either side of zero. Current indications are that a wind chill advisory would be needed across the northern CWA Wednesday night and early Thursday, as the system to our south keeps the winds up and slows the arrival of high pressure. Heading into the weekend and early next week, 40s should become more widespread, and the latest 8-14 day outlook introduces a foreign concept called "above normal temperatures". && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 500 AM CST TUE MAR 3 2015 MVFR cigs expected to deteriorate to IFR/LIFR this morning as the freezing rain/drizzle continues. We expect a change over to light rain at SPI between 14z-16z, CMI between 15z-17z and BMI and PIA between 17z-18z. IFR to LIFR cigs will continue this afternoon along with some light rain at times with short term models suggesting a slight improvement to MVFR cigs after 21z as drier air works east into the region. However, will continue with MVFR cigs thru at least 02z this evening. Surface winds at all sites will become south and increase to between 12 and 17 kts by 16z with gusts in the 20-23kt range into the afternoon hours. We will see the direction begin to veer more into the southwest and west as a cold front approaches the area this afternoon and then into the northwest at 10 to 15 kts just after 00z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Onton SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
549 AM CST TUE MAR 3 2015 .SHORT TERM... 300 AM CST THROUGH WEDNESDAY... MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING. SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE BEFORE ENDING ALTOGETHER THIS EVENING. HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER DEUBELBEISS && .LONG TERM... 300 AM CST WEDNESDAY NIGHT THROUGH MONDAY... FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING. FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT DOESNT COME THROUGH DRY. DEUBELBEISS && .CLIMATE... A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN JEOPARDY ON WEDNESDAY AND THURSDAY. HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO THEM. WED 3/4 THU 3/5 ROCKFORD RECORD LOW-11 (2002)-11 (2002) RECORD LOW MAX 14 (2002)* 17 (1960)* CHICAGO RECORD LOW-12 (1873) 0 (1978)* RECORD LOW MAX 17 (1890)* 12 (1901) KMD/KJB/BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * SNOW...SLEET AND FREEZING RAIN THIS MORNING EVENTUALLY TURNING TO RAIN/DRIZZLE AS TEMPS RISE ABOVE FREEZING LATE MORNING/MIDDAY. GENERALLY IFR/LIFR CONDITIONS THIS MORNING WITH CONDITIONS IMPROVING TO MVFR CIGS AND HIGHER VSBYS LATE AFTN AND EVENING. * SOUTHEAST WINDS BECOMING GUSTY AROUND 20 KT FROM THE SOUTH BY LATE MORNING AND SOUTHWEST THIS AFTERNOON. WEST-NORTHWEST WINDS TONIGHT REMAIN GUSTY. RATZER //DISCUSSION...UPDATED 12Z... AREA OF PRECIPITATION HAS OVERSPREAD THE TERMINALS EARLY THIS MORNING...WITH SOME MODERATE SNOW AT TIMES FROM ORD NORTH/NORTHWEST. NORTHERN TERMINALS...RFD...DPA...ORD WILL LIKELY CONTINUE TO BE THE FOCUS FOR HEAVIER SNOW/SLEET THIS MORNING WITH OCCASIONALLY LOWER VIS/CIG CONDITIONS RESULTING. FARTHER SOUTH SOME DRYING IN THE MID-LEVELS IS RESULTING IN LIGHTER PRECIP WHICH WILL AFFECT MDW/GYY...AND MAY RESULT IN MORE OF A FZRA/FZDZ TREND RATHER THAN SNOW FOR MUCH OF THE MORNING AT THOSE LOCATIONS. IN ANY CASE...WARMING ALOFT WILL EVENTUALLY TURN PRECIP FROM SNOW TO SLEET/FREEZING RAIN OR DRIZZLE OVER THE NEXT FEW HOURS...AND EVENTUALLY TO RAIN/DRIZZLE AS SURFACE TEMPS RISE ABOVE FREEZING LATER THIS MORNING. PRECIP IS EXPECTED TO END LATER THIS AFTERNOON AS WINDS SHIFT WEST AND DRIER AIR FILTERS IN. SPEAKING OF WINDS...WINDS ARE CURRENTLY SOUTHEAST AROUND 10 KT BUT WILL INCREASE 10-15 KT WITH GUSTS AROUND 20 KT BY LATE MORNING... BACKING TO THE SOUTH AND SOUTHWEST INTO THIS AFTERNOON AS LOW PRESSURE MOVES ACROSS WISCONSIN. TRAILING COLD FRONT WILL SHIFT WINDS WEST THIS EVENING...WITH GUSTS 20-25 KT LINGERING INTO TONIGHT. RATZER //ORD AND MDW CONFIDENCE...UPDATED 12Z... * MEDIUM IN TIMING OF PRECIP TYPE CHANGES AND CIG/VIS IMPACTS. * HIGH IN WIND TRENDS...AND IN MVFR OR BETTER CONDITIONS BY THIS EVENING. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT THROUGH FRIDAY...VFR. SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE. RATZER && .MARINE... 214 AM CST MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS TO RELAX A BIT AND SHIFT TO THE WEST. SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS. RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR TO HAVE A FAIR AMOUNT OF OPEN WATER. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008- ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021- ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY. IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL NOON TUESDAY. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 507 AM CST Tue Mar 3 2015 .SHORT TERM...(Today) ISSUED AT 244 AM CST TUE MAR 3 2015 Freezing rain and sleet developed over western Illinois around midnight and quickly tracked east over all but extreme southeast Illinois by 08z/2am. Already seeing the back edge of our second band of wintry precip entering west central Illinois, so it appears we will have a brief lull in the freezing rain and sleet. However, the latest HRRR suggests another band of rain, freezing rain and sleet will move northeast across our area at or just after dawn. Rainfall rates have not been much with these quick moving bands of freezing rain/sleet with most areas seeing less than 0.05" per hour, but certainly enough for some light icing to occur on bridge decks and overpasses and on lesser traveled roads. RAP forecast soundings continue to suggest temperatures will rise above the freezing mark over southeast Illinois by dawn...central sections of the forecast area by 900 am...and between 10 am and Noon roughly along and north of the Interstate 74 corridor. By late morning into the afternoon hours the stronger lift associated with the low level warm advection/ isentropic ascent shifts off to our east and southeast with a gradual lowering of POPs warranted from northwest to southeast. Best 850-700 forcing edges into southeast IL by mid to late afternoon where our highest POPs will be located. Guidance temperatures look reasonable for this afternoon with highs ranging from the upper 30s far north to the upper 40s far southeast. && .LONG TERM...(Tonight through Monday) ISSUED AT 244 AM CST TUE MAR 3 2015 Current system will not fully clear our area until Thursday, as the trailing end of the cold front becomes parallel to the upper flow over the Ohio Valley. Most of the evening models keep the threat for precipitation from about I-70 southward, although the NAM has a secondary surge on Wednesday afternoon all the way up to about I-72. Leaning more toward the ECMWF/GFS blend for PoP`s tonight and Wednesday. Lingering precip north of I-70 should end this evening, but kept higher PoP`s all night into Wednesday. This evening, most areas will see the precipitation switch briefly to snow before ending, with little accumulation. While the transition to snow south of I-70 occurs late tonight, temperatures will be supportive of all snow through Wednesday. Greatest snow amounts expected near the Ohio Valley, but currently think that 1 to 3 inches in southeast Illinois is likely. Light snow will linger into Wednesday night before ending late. The other feature of note is what hopefully will be the last Arctic blast of the winter. Digging upper trough currently coming into Manitoba will spread a chunk of unseasonably cold air over much of the Midwest Wednesday and Thursday, with 850 mb temperatures down into the -18C range by Thursday morning. Highs both days will struggle to get out of the teens in some areas -- normal highs are well into the 40s by now -- and lows Thursday morning should be a few degrees either side of zero. Current indications are that a wind chill advisory would be needed across the northern CWA Wednesday night and early Thursday, as the system to our south keeps the winds up and slows the arrival of high pressure. Heading into the weekend and early next week, 40s should become more widespread, and the latest 8-14 day outlook introduces a foreign concept called "above normal temperatures". && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 500 AM CST TUE MAR 3 2015 MVFR cigs expected to deteriorate to IFR/LIFR this morning as the freezing rain/drizzle continues. We expect a change over to light rain at SPI between 14z-16z, CMI between 15z-17z and BMI and PIA between 17z-18z. IFR to LIFR cigs will continue this afternoon along with some light rain at times with short term models suggesting a slight improvement to MVFR cigs after 21z as drier air works east into the region. However, will continue with MVFR cigs thru at least 02z this evening. Surface winds at all sites will become south and increase to between 12 and 17 kts by 16z with gusts in the 20-23kt range into the afternoon hours. We will see the direction begin to veer more into the southwest and west as a cold front approaches the area this afternoon and then into the northwest at 10 to 15 kts just after 00z. && .ILX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY until 10 AM CST this morning FOR ILZ027>031-036>038-040>057-061>063-066>068-071>073. && $$ SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 AM CST TUE MAR 3 2015 .SHORT TERM... 300 AM CST THROUGH WEDNESDAY... MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING. SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE BEFORE ENDING ALTOGETHER THIS EVENING. HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER DEUBELBEISS && .LONG TERM... 300 AM CST WEDNESDAY NIGHT THROUGH MONDAY... FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING. FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT DOESNT COME THROUGH DRY. DEUBELBEISS && .CLIMATE... A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN JEOPARDY ON WEDNESDAY AND THURSDAY. HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO THEM. WED 3/4 THU 3/5 ROCKFORD RECORD LOW-11 (2002)-11 (2002) RECORD LOW MAX 14 (2002)* 17 (1960)* CHICAGO RECORD LOW-12 (1873) 0 (1978)* RECORD LOW MAX 17 (1890)* 12 (1901) KMD/KJB/BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SNOW EXPECTED TO DEVELOP DURING PREDAWN HOURS...QUICKLY TRANSITIONING TO A SNOW/SLEET MIX AND THEN FREEZING RAIN DURING THE MORNING. TEMPS RISE TO/ABOVE FREEZING BY MIDDAY WITH PRECIP CHANGING TO RAIN/DRIZZLE. * CIG/VIS EXPECTED TO DETERIORATE FAIRLY QUICKLY FROM VFR TO IFR/LIFR WITH PRECIPITATION THIS MORNING. SLOW IMPROVEMENT IN CONDITIONS EXPECTED LATER THIS AFTERNOON/EVENING...WITH MVFR CIGS LIKELY LINGERING TONIGHT. * SOUTH-SOUTHEAST WINDS INCREASING 10-15 KT EARLY THIS MORNING AND BECOMING GUSTY AROUND 20 KTS AT TIMES WHILE BACKING SOUTH LATE THIS MORNING. SOUTHWEST WINDS GUSTING AROUND 20 KTS THIS AFTERNOON BECOME WEST-NORTHWEST BY EARLY EVENING AND REMAINING GUSTY. RATZER //DISCUSSION...UPDATED 06Z... LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO AROUND MIDNIGHT... WITH SOUTH-SOUTHEAST WINDS INCREASING ACROSS THE PLAINS AND MIDWEST AND STARTING TO PULL MOISTURE NORTHWARD FROM THE WESTERN GULF. REGIONAL RADAR MOSAIC SHOWS PRECIPITATION BLOSSOMING ACROSS THE MID-MISSISSIPPI VALLEY AND LIFTING NORTHEAST AHEAD OF WARM FRONT DEVELOPING ACROSS MISSOURI AND KANSAS. FORECAST MODELS CONTINUE TO DEPICT PRECIPITATION SPREADING ACROSS THE LOCAL TERMINALS ROUGHLY 10-12Z...WITH THERMAL PROFILES SUPPORTING INITIALLY SNOW...QUICKLY MIXING WITH SLEET AND FREEZING RAIN AS TEMPERATURES WARM ALOFT. SURFACE TEMPS LOOK TO CLIMB TO/ABOVE FREEZING BY LATE MORNING OR MIDDAY WITH ANY LINGERING PRECIPITATION IN THE FORM OF RAIN OR DRIZZLE AS THE BETTER FORCING WITH THE ELEVATED WARM FRONT LIFTS NORTH OF THE AREA. WITH DEVELOPMENT OF PRECIPITATION...GUIDANCE REMAINS STEADFAST IN A RAPID DETERIORATION OF VFR CONDITIONS TO IFR/LIFR WITHIN A FEW HOURS OF ONSET. CIGS SHOULD LIFT ABOVE LIFR THIS AFTERNOON AS WARM FRONT MOVES NORTH...AND EVENTUALLY TO MVFR LATE THIS AFTERNOON AND THIS EVENING AS A COLD FRONT PUSHES EAST ACROSS THE AREA. SOUTH-SOUTHEAST WINDS WILL BACK MORE SOUTHEAST EARLY THIS MORNING AND INCREASE INTO THE 10-15 KT RANGE AS THE LOW MOVES QUICKLY ACROSS THE PLAINS. WINDS WILL BACK SOUTH BY LATE MORNING/EARLY AFTERNOON AS THE LOW PASSES NORTH ACROSS WISCONSIN. FORECAST SOUNDINGS SUPPORT GUSTS AROUND 20 KTS BY LATE MORNING...AND CONTINUE TO INDICATE GUSTY CONDITIONS AS WINDS SHIFT SOUTHWEST THIS AFTERNOON AND WEST-NORTHWEST THIS EVENING. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM IN TIMING PRECIP DEVELOPMENT AND TRANSITION OF P-TYPES AS WELL AS CIG/VIS IMPACTS. * HIGH IN WINDS...AND DRY WEATHER WITH LINGERING MVFR CIGS THIS EVENING. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z TUESDAY...UPDATED 00Z... WEDNESDAY...MVFR CIGS. THURSDAY AND FRIDAY...VFR. SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE. BEACHLER && .MARINE... 214 AM CST MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS TO RELAX A BIT AND SHIFT TO THE WEST. SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS. RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR TO HAVE A FAIR AMOUNT OF OPEN WATER. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008- ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021- ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY. IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL NOON TUESDAY. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 247 AM CST Tue Mar 3 2015 .SHORT TERM...(Today) ISSUED AT 244 AM CST TUE MAR 3 2015 Freezing rain and sleet developed over western Illinois around midnight and quickly tracked east over all but extreme southeast Illinois by 08z/2am. Already seeing the back edge of our second band of wintry precip entering west central Illinois, so it appears we will have a brief lull in the freezing rain and sleet. However, the latest HRRR suggests another band of rain, freezing rain and sleet will move northeast across our area at or just after dawn. Rainfall rates have not been much with these quick moving bands of freezing rain/sleet with most areas seeing less than 0.05" per hour, but certainly enough for some light icing to occur on bridge decks and overpasses and on lesser traveled roads. RAP forecast soundings continue to suggest temperatures will rise above the freezing mark over southeast Illinois by dawn...central sections of the forecast area by 900 am...and between 10 am and Noon roughly along and north of the Interstate 74 corridor. By late morning into the afternoon hours the stronger lift associated with the low level warm advection/ isentropic ascent shifts off to our east and southeast with a gradual lowering of POPs warranted from northwest to southeast. Best 850-700 forcing edges into southeast IL by mid to late afternoon where our highest POPs will be located. Guidance temperatures look reasonable for this afternoon with highs ranging from the upper 30s far north to the upper 40s far southeast. && .LONG TERM...(Tonight through Monday) ISSUED AT 244 AM CST TUE MAR 3 2015 Current system will not fully clear our area until Thursday, as the trailing end of the cold front becomes parallel to the upper flow over the Ohio Valley. Most of the evening models keep the threat for precipitation from about I-70 southward, although the NAM has a secondary surge on Wednesday afternoon all the way up to about I-72. Leaning more toward the ECMWF/GFS blend for PoP`s tonight and Wednesday. Lingering precip north of I-70 should end this evening, but kept higher PoP`s all night into Wednesday. This evening, most areas will see the precipitation switch briefly to snow before ending, with little accumulation. While the transition to snow south of I-70 occurs late tonight, temperatures will be supportive of all snow through Wednesday. Greatest snow amounts expected near the Ohio Valley, but currently think that 1 to 3 inches in southeast Illinois is likely. Light snow will linger into Wednesday night before ending late. The other feature of note is what hopefully will be the last Arctic blast of the winter. Digging upper trough currently coming into Manitoba will spread a chunk of unseasonably cold air over much of the Midwest Wednesday and Thursday, with 850 mb temperatures down into the -18C range by Thursday morning. Highs both days will struggle to get out of the teens in some areas -- normal highs are well into the 40s by now -- and lows Thursday morning should be a few degrees either side of zero. Current indications are that a wind chill advisory would be needed across the northern CWA Wednesday night and early Thursday, as the system to our south keeps the winds up and slows the arrival of high pressure. Heading into the weekend and early next week, 40s should become more widespread, and the latest 8-14 day outlook introduces a foreign concept called "above normal temperatures". && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1147 PM CST MON MAR 2 2015 Freezing rain and sleet is still expected to move into the area and effect all the TAFs in the next 1 to 3 hours, starting in SPI and PIA and then move east. The pcpn will start as a mix of FZRA and PL given how dry the lower layers are. Then in a few hours, it will change over to all FZRA and then last until morning, when the temp rises to above freezing. Expecting the FZRA to last around 4hrs at each site. Cigs and vis will be VFR to start but then drop into the IFR category later overnight. The rain will end at the sites late afternoon or early evening as the front moves through. Winds will be southeast and then become south during the morning, then become westerly when the front moves through. Could be some gusts to around 22kts in the morning and afternoon. && .ILX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY until 10 AM CST this morning FOR ILZ027>031-036>038-040>057-061>063-066>068-071>073. && $$ SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Auten
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
215 AM CST TUE MAR 3 2015 .UPDATE... 758 PM CST THE FORECAST REMAINS ON TRACK WITH THE NEXT SYSTEM OVER COLORADO THIS EVENING. GUIDANCE CONTINUES TO SUGGEST THAT THE LOW WILL REACH SOUTHERN WISCONSIN MID-DAY TUESDAY AND MERGE WITH A STRONGER LOW PUSHING EAST ACROSS ONTARIO. PRECIP WILL SPREAD ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST EARLY TUESDAY MORNING. PRECIP SHOULD INITIALLY FALL AS SNOW...BUT WILL QUICKLY TURN OVER TO A WINTRY MIX AS TEMPERATURES WARM TO ABOVE ZERO ALOFT AND WE LOSE SATURATION IN THE DGZ. WILL KEEP THE WINTER WEATHER ADVISORY AS IS. JEE && .SHORT TERM... 317 PM CST THROUGH WEDNESDAY... .SHORT TERM...THROUGH WEDNESDAY AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION BEGINS. A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS. THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR MASS..AND DEW POINTS ARE STILL VERY LOW ACROSS THE AREA...WITH DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE. MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION POTENTIAL. WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE 80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH. WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME -SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE AFTERNOON AND EVENING. THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO THE AFD WILL BE FORTHCOMING. KMD && .LONG TERM... 317 PM CST THURSDAY THROUGH MONDAY... THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD. KJB && .CLIMATE... A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN JEOPARDY ON WEDNESDAY AND THURSDAY. HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO THEM. WED 3/4 THU 3/5 ROCKFORD RECORD LOW-11 (2002)-11 (2002) RECORD LOW MAX 14 (2002)* 17 (1960)* CHICAGO RECORD LOW-12 (1873) 0 (1978)* RECORD LOW MAX 17 (1890)* 12 (1901) KMD/KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SNOW EXPECTED TO DEVELOP DURING PREDAWN HOURS...QUICKLY TRANSITIONING TO A SNOW/SLEET MIX AND THEN FREEZING RAIN DURING THE MORNING. TEMPS RISE TO/ABOVE FREEZING BY MIDDAY WITH PRECIP CHANGING TO RAIN/DRIZZLE. * CIG/VIS EXPECTED TO DETERIORATE FAIRLY QUICKLY FROM VFR TO IFR/LIFR WITH PRECIPITATION THIS MORNING. SLOW IMPROVEMENT IN CONDITIONS EXPECTED LATER THIS AFTERNOON/EVENING...WITH MVFR CIGS LIKELY LINGERING TONIGHT. * SOUTH-SOUTHEAST WINDS INCREASING 10-15 KT EARLY THIS MORNING AND BECOMING GUSTY AROUND 20 KTS AT TIMES WHILE BACKING SOUTH LATE THIS MORNING. SOUTHWEST WINDS GUSTING AROUND 20 KTS THIS AFTERNOON BECOME WEST-NORTHWEST BY EARLY EVENING AND REMAINING GUSTY. RATZER //DISCUSSION...UPDATED 06Z... LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO AROUND MIDNIGHT... WITH SOUTH-SOUTHEAST WINDS INCREASING ACROSS THE PLAINS AND MIDWEST AND STARTING TO PULL MOISTURE NORTHWARD FROM THE WESTERN GULF. REGIONAL RADAR MOSAIC SHOWS PRECIPITATION BLOSSOMING ACROSS THE MID-MISSISSIPPI VALLEY AND LIFTING NORTHEAST AHEAD OF WARM FRONT DEVELOPING ACROSS MISSOURI AND KANSAS. FORECAST MODELS CONTINUE TO DEPICT PRECIPITATION SPREADING ACROSS THE LOCAL TERMINALS ROUGHLY 10-12Z...WITH THERMAL PROFILES SUPPORTING INITIALLY SNOW...QUICKLY MIXING WITH SLEET AND FREEZING RAIN AS TEMPERATURES WARM ALOFT. SURFACE TEMPS LOOK TO CLIMB TO/ABOVE FREEZING BY LATE MORNING OR MIDDAY WITH ANY LINGERING PRECIPITATION IN THE FORM OF RAIN OR DRIZZLE AS THE BETTER FORCING WITH THE ELEVATED WARM FRONT LIFTS NORTH OF THE AREA. WITH DEVELOPMENT OF PRECIPITATION...GUIDANCE REMAINS STEADFAST IN A RAPID DETERIORATION OF VFR CONDITIONS TO IFR/LIFR WITHIN A FEW HOURS OF ONSET. CIGS SHOULD LIFT ABOVE LIFR THIS AFTERNOON AS WARM FRONT MOVES NORTH...AND EVENTUALLY TO MVFR LATE THIS AFTERNOON AND THIS EVENING AS A COLD FRONT PUSHES EAST ACROSS THE AREA. SOUTH-SOUTHEAST WINDS WILL BACK MORE SOUTHEAST EARLY THIS MORNING AND INCREASE INTO THE 10-15 KT RANGE AS THE LOW MOVES QUICKLY ACROSS THE PLAINS. WINDS WILL BACK SOUTH BY LATE MORNING/EARLY AFTERNOON AS THE LOW PASSES NORTH ACROSS WISCONSIN. FORECAST SOUNDINGS SUPPORT GUSTS AROUND 20 KTS BY LATE MORNING...AND CONTINUE TO INDICATE GUSTY CONDITIONS AS WINDS SHIFT SOUTHWEST THIS AFTERNOON AND WEST-NORTHWEST THIS EVENING. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM IN TIMING PRECIP DEVELOPMENT AND TRANSITION OF P-TYPES AS WELL AS CIG/VIS IMPACTS. * HIGH IN WINDS...AND DRY WEATHER WITH LINGERING MVFR CIGS THIS EVENING. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z TUESDAY...UPDATED 00Z... WEDNESDAY...MVFR CIGS. THURSDAY AND FRIDAY...VFR. SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE. BEACHLER && .MARINE... 214 AM CST MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS TO RELAX A BIT AND SHIFT TO THE WEST. SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS. RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR TO HAVE A FAIR AMOUNT OF OPEN WATER. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008- ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021- ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY. IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL NOON TUESDAY. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1200 AM CST TUE MAR 3 2015 .UPDATE... 758 PM CST THE FORECAST REMAINS ON TRACK WITH THE NEXT SYSTEM OVER COLORADO THIS EVENING. GUIDANCE CONTINUES TO SUGGEST THAT THE LOW WILL REACH SOUTHERN WISCONSIN MID-DAY TUESDAY AND MERGE WITH A STRONGER LOW PUSHING EAST ACROSS ONTARIO. PRECIP WILL SPREAD ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST EARLY TUESDAY MORNING. PRECIP SHOULD INITIALLY FALL AS SNOW...BUT WILL QUICKLY TURN OVER TO A WINTRY MIX AS TEMPERATURES WARM TO ABOVE ZERO ALOFT AND WE LOSE SATURATION IN THE DGZ. WILL KEEP THE WINTER WEATHER ADVISORY AS IS. JEE && .SHORT TERM... 317 PM CST THROUGH WEDNESDAY... .SHORT TERM...THROUGH WEDNESDAY AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION BEGINS. A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS. THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR MASS..AND DEW POINTS ARE STILL VERY LOW ACROSS THE AREA...WITH DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE. MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION POTENTIAL. WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE 80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH. WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME -SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE AFTERNOON AND EVENING. THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO THE AFD WILL BE FORTHCOMING. KMD && .LONG TERM... 317 PM CST THURSDAY THROUGH MONDAY... THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD. KJB && .CLIMATE... A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN JEOPARDY ON WEDNESDAY AND THURSDAY. HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO THEM. WED 3/4 THU 3/5 ROCKFORD RECORD LOW-11 (2002)-11 (2002) RECORD LOW MAX 14 (2002)* 17 (1960)* CHICAGO RECORD LOW-12 (1873) 0 (1978)* RECORD LOW MAX 17 (1890)* 12 (1901) KMD/KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SNOW EXPECTED TO DEVELOP DURING PREDAWN HOURS...QUICKLY TRANSITIONING TO A SNOW/SLEET MIX AND THEN FREEZING RAIN DURING THE MORNING. TEMPS RISE TO/ABOVE FREEZING BY MIDDAY WITH PRECIP CHANGING TO RAIN/DRIZZLE. * CIG/VIS EXPECTED TO DETERIORATE FAIRLY QUICKLY FROM VFR TO IFR/LIFR WITH PRECIPITATION THIS MORNING. SLOW IMPROVEMENT IN CONDITIONS EXPECTED LATER THIS AFTERNOON/EVENING...WITH MVFR CIGS LIKELY LINGERING TONIGHT. * SOUTH-SOUTHEAST WINDS INCREASING 10-15 KT EARLY THIS MORNING AND BECOMING GUSTY AROUND 20 KTS AT TIMES WHILE BACKING SOUTH LATE THIS MORNING. SOUTHWEST WINDS GUSTING AROUND 20 KTS THIS AFTERNOON BECOME WEST-NORTHWEST BY EARLY EVENING AND REMAINING GUSTY. RATZER //DISCUSSION...UPDATED 06Z... LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO AROUND MIDNIGHT... WITH SOUTH-SOUTHEAST WINDS INCREASING ACROSS THE PLAINS AND MIDWEST AND STARTING TO PULL MOISTURE NORTHWARD FROM THE WESTERN GULF. REGIONAL RADAR MOSAIC SHOWS PRECIPITATION BLOSSOMING ACROSS THE MID-MISSISSIPPI VALLEY AND LIFTING NORTHEAST AHEAD OF WARM FRONT DEVELOPING ACROSS MISSOURI AND KANSAS. FORECAST MODELS CONTINUE TO DEPICT PRECIPITATION SPREADING ACROSS THE LOCAL TERMINALS ROUGHLY 10-12Z...WITH THERMAL PROFILES SUPPORTING INITIALLY SNOW...QUICKLY MIXING WITH SLEET AND FREEZING RAIN AS TEMPERATURES WARM ALOFT. SURFACE TEMPS LOOK TO CLIMB TO/ABOVE FREEZING BY LATE MORNING OR MIDDAY WITH ANY LINGERING PRECIPITATION IN THE FORM OF RAIN OR DRIZZLE AS THE BETTER FORCING WITH THE ELEVATED WARM FRONT LIFTS NORTH OF THE AREA. WITH DEVELOPMENT OF PRECIPITATION...GUIDANCE REMAINS STEADFAST IN A RAPID DETERIORATION OF VFR CONDITIONS TO IFR/LIFR WITHIN A FEW HOURS OF ONSET. CIGS SHOULD LIFT ABOVE LIFR THIS AFTERNOON AS WARM FRONT MOVES NORTH...AND EVENTUALLY TO MVFR LATE THIS AFTERNOON AND THIS EVENING AS A COLD FRONT PUSHES EAST ACROSS THE AREA. SOUTH-SOUTHEAST WINDS WILL BACK MORE SOUTHEAST EARLY THIS MORNING AND INCREASE INTO THE 10-15 KT RANGE AS THE LOW MOVES QUICKLY ACROSS THE PLAINS. WINDS WILL BACK SOUTH BY LATE MORNING/EARLY AFTERNOON AS THE LOW PASSES NORTH ACROSS WISCONSIN. FORECAST SOUNDINGS SUPPORT GUSTS AROUND 20 KTS BY LATE MORNING...AND CONTINUE TO INDICATE GUSTY CONDITIONS AS WINDS SHIFT SOUTHWEST THIS AFTERNOON AND WEST-NORTHWEST THIS EVENING. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM IN TIMING PRECIP DEVELOPMENT AND TRANSITION OF P-TYPES AS WELL AS CIG/VIS IMPACTS. * HIGH IN WINDS...AND DRY WEATHER WITH LINGERING MVFR CIGS THIS EVENING. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z TUESDAY...UPDATED 00Z... WEDNESDAY...MVFR CIGS. THURSDAY AND FRIDAY...VFR. SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE. BEACHLER && .MARINE... 224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008- ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021- ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON TUESDAY. IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3 AM TUESDAY TO NOON TUESDAY. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
917 PM EST WED MAR 4 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 330 PM EST WED MAR 4 2015 LIGHT SNOW ON THE NORTHERN FRINGES OF A BAND OF PRECIPITATION ASSOCIATED WITH A FRONT TO OUR SOUTH WILL CONTINUE INTO THIS EVENING AND THE EARLY PORTION OF THE OVERNIGHT BEFORE TAPERING OFF. A VERY TIGHT GRADIENT IS EXPECTED AND THUS SIGNIFICANT VARIATION COULD OCCUR WITHIN A VERY SHORT DISTANCE. BEYOND TONIGHT...DRY WEATHER IS THE RULE FOR THE REMAINDER OF THE SEVEN DAY FORECAST. HIGH PRESSURE WILL CREATE VERY COLD CONDITIONS THROUGH FRIDAY...WITH SUB ZERO TEMPERATURES POSSIBLE THURSDAY NIGHT INTO FRIDAY MORNING...BEFORE TEMPERATURES MODERATE SIGNIFICANTLY ACROSS THE REGION. && .NEAR TERM /THIS AFTERNOON AND TONIGHT/... ISSUED AT 330 PM EST WED MAR 4 2015 SNOW FORECAST ACROSS THE SOUTH ESSENTIALLY A NOWCASTING ISSUE AT THIS POINT. BASED ON HRRR AND NATIONAL RADAR MOSAIC TRENDS...HAVE TIGHTENED UP GRADIENT EVEN MORE ACROSS THE SOUTH...EFFECTIVELY DECREASING EXPECTED SNOW HERE IN THE INDY METRO DOWN TO A FEW TENTHS AT BEST. AMOUNTS ARE BASICALLY THE SAME ACROSS THE SOUTH...1 TO 3 ALONG A SULLIVAN TO BLOOMINGTON AND GREENSBURG LINE...AND 2 TO 5 ALONG A VINCENNES TO NORTH VERNON LINE. COULD SEE ISOLATED SPOTS PUSH 6 ACROSS OUR FAR SOUTHERN/SOUTHEASTERN FRINGE. HIGHER RESOLUTION MODELS MOVE THE SNOW OUT FASTER LATE TONIGHT AND HAVE GENERALLY TRENDED TOWARD A SLIGHTLY FASTER END. WILL KEEP ADVISORY GOING AS IS AS CHANGES HAVE BEEN RELATIVELY MINOR AND SEE NO REASON TO DEVIATE FROM CURRENT COURSE OF ACTION. TIGHTENED UP TEMPERATURE GRADIENT DEPICTED BY CONSENSUS TEMPS ON MINS TONIGHT...WITH MID SINGLE DIGITS NORTH TO MID TEENS SOUTH. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... ISSUED AT 330 PM EST WED MAR 4 2015 DRY WEATHER RETURNS TOMORROW AND WILL PERSIST THROUGH THE PERIOD. THIS LEAVES TEMPERATURES AS THE SIGNIFICANT FOCUS. CONSENSUS NUMBERS REQUIRED SOME SLIGHT DOWNWARD TWEAKS...ESPECIALLY ON MIN TEMPS WITH A STILL FAIRLY DEEP SNOWPACK AND HIGH PRESSURE BUILDING INTO THE REGION. SUB ZERO TEMPERATURES ARE IN PLAY FOR THURSDAY NIGHT...SOMETHING THAT HAS ONLY HAPPENED ON TEN OTHER OCCASIONS OF RECORD AT INDIANAPOLIS IN MARCH...AND NOT SINCE 9 MARCH 1984. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... ISSUED AT 145 PM EST WED MAR 4 2015 THIS IS A HIGH CONFIDENCE FORECAST. THE INITIALIZATION FROM THE REGIONAL SOFTWARE IS ACCEPTED. THE GFS ENSEMBLE SPREAD IS QUITE LOW FOR THE PERIOD...SO THERE IS A HIGH CHANCE THE INITIALIZATION WILL VERIFY. ALSO...WHILE THE EUROPEAN AND GFS MODELS HAVE SOME DIFFERENCES IN THEIR DETERMINISTIC FIELDS...THEIR STATISTICAL GUIDANCE IS CLOSE. IN A SENSE IT DOESNT MATTER WHICH VERIFIES BETTER...WE CAN EXPECT THE SAME SENSIBLE WEATHER EITHER WAY. && .AVIATION /DISCUSSION FOR 050300Z TAF ISSUANCE/... ISSUED AT 917 PM EST WED MAR 4 2015 SNOW HAS MOVED OUT OF THE SITES AND WITH THE POSSIBLE EXCEPTION OF A FLURRY AT KBMG SHOULD BE DRY FOR THE REST OF THE NIGHT AT ALL THE SITES. AT KLAF EXPECT TO SEE NOTHING BUT VFR CONDITIONS THROUGH THE PERIOD. ALL THE SITES SHOULD BE VFR THROUGH THE OVERNIGHT. WITH TIME HEIGHTS SHOWING SOME LOW LEVEL MOISTURE HANGING AROUND THROUGH THE DAY TOMORROW AS THE HIGH BUILDS TOWARD THE AREA...COULD SEE SOME MVFR STRATOCU DEVELOP WITH AFTERNOON SUNSHINE AT ALL BUT KLAF WHICH WILL BE CLOSEST TO THE HIGH. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 9 AM EST THURSDAY FOR INZ061>065- 067>072. && $$ SYNOPSIS...NIELD NEAR TERM...NIELD SHORT TERM...NIELD LONG TERM...JK AVIATION...CP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
626 PM EST WED MAR 4 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 330 PM EST WED MAR 4 2015 LIGHT SNOW ON THE NORTHERN FRINGES OF A BAND OF PRECIPITATION ASSOCIATED WITH A FRONT TO OUR SOUTH WILL CONTINUE INTO THIS EVENING AND THE EARLY PORTION OF THE OVERNIGHT BEFORE TAPERING OFF. A VERY TIGHT GRADIENT IS EXPECTED AND THUS SIGNIFICANT VARIATION COULD OCCUR WITHIN A VERY SHORT DISTANCE. BEYOND TONIGHT...DRY WEATHER IS THE RULE FOR THE REMAINDER OF THE SEVEN DAY FORECAST. HIGH PRESSURE WILL CREATE VERY COLD CONDITIONS THROUGH FRIDAY...WITH SUB ZERO TEMPERATURES POSSIBLE THURSDAY NIGHT INTO FRIDAY MORNING...BEFORE TEMPERATURES MODERATE SIGNIFICANTLY ACROSS THE REGION. && .NEAR TERM /THIS AFTERNOON AND TONIGHT/... ISSUED AT 330 PM EST WED MAR 4 2015 SNOW FORECAST ACROSS THE SOUTH ESSENTIALLY A NOWCASTING ISSUE AT THIS POINT. BASED ON HRRR AND NATIONAL RADAR MOSAIC TRENDS...HAVE TIGHTENED UP GRADIENT EVEN MORE ACROSS THE SOUTH...EFFECTIVELY DECREASING EXPECTED SNOW HERE IN THE INDY METRO DOWN TO A FEW TENTHS AT BEST. AMOUNTS ARE BASICALLY THE SAME ACROSS THE SOUTH...1 TO 3 ALONG A SULLIVAN TO BLOOMINGTON AND GREENSBURG LINE...AND 2 TO 5 ALONG A VINCENNES TO NORTH VERNON LINE. COULD SEE ISOLATED SPOTS PUSH 6 ACROSS OUR FAR SOUTHERN/SOUTHEASTERN FRINGE. HIGHER RESOLUTION MODELS MOVE THE SNOW OUT FASTER LATE TONIGHT AND HAVE GENERALLY TRENDED TOWARD A SLIGHTLY FASTER END. WILL KEEP ADVISORY GOING AS IS AS CHANGES HAVE BEEN RELATIVELY MINOR AND SEE NO REASON TO DEVIATE FROM CURRENT COURSE OF ACTION. TIGHTENED UP TEMPERATURE GRADIENT DEPICTED BY CONSENSUS TEMPS ON MINS TONIGHT...WITH MID SINGLE DIGITS NORTH TO MID TEENS SOUTH. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... ISSUED AT 330 PM EST WED MAR 4 2015 DRY WEATHER RETURNS TOMORROW AND WILL PERSIST THROUGH THE PERIOD. THIS LEAVES TEMPERATURES AS THE SIGNIFICANT FOCUS. CONSENSUS NUMBERS REQUIRED SOME SLIGHT DOWNWARD TWEAKS...ESPECIALLY ON MIN TEMPS WITH A STILL FAIRLY DEEP SNOWPACK AND HIGH PRESSURE BUILDING INTO THE REGION. SUB ZERO TEMPERATURES ARE IN PLAY FOR THURSDAY NIGHT...SOMETHING THAT HAS ONLY HAPPENED ON TEN OTHER OCCASIONS OF RECORD AT INDIANAPOLIS IN MARCH...AND NOT SINCE 9 MARCH 1984. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... ISSUED AT 145 PM EST WED MAR 4 2015 THIS IS A HIGH CONFIDENCE FORECAST. THE INITIALIZATION FROM THE REGIONAL SOFTWARE IS ACCEPTED. THE GFS ENSEMBLE SPREAD IS QUITE LOW FOR THE PERIOD...SO THERE IS A HIGH CHANCE THE INITIALIZATION WILL VERIFY. ALSO...WHILE THE EUROPEAN AND GFS MODELS HAVE SOME DIFFERENCES IN THEIR DETERMINISTIC FIELDS...THEIR STATISTICAL GUIDANCE IS CLOSE. IN A SENSE IT DOESNT MATTER WHICH VERIFIES BETTER...WE CAN EXPECT THE SAME SENSIBLE WEATHER EITHER WAY. && .AVIATION /DISCUSSION FOR 050000Z TAF ISSUANCE/... ISSUED AT 619 PM EST WED MAR 4 2015 SNOW CONTINUES TO FALL AT KBMG AND WILL FOR THE NEXT SEVERAL HOURS...BUT CONDITIONS THERE HAVE ALREADY IMPROVED TO IFR AND WILL CONTINUE TO IMPROVE TO MVFR OVER THE NEXT COUPLE OF HOURS. AT KLAF EXPECT TO SEE NOTHING BUT VFR CONDITIONS THROUGH THE PERIOD...WITH SOME WIND GUSTS TO AROUND 18 KTS OUT OF THE NORTHWEST OFF AND ON THROUGH AROUND 6Z OR SO. AT KIND EXPECT TO SEE SIMILAR WIND GUSTS. WHILE KIND COULD SEE A FLURRY OR TWO YET DO NOT THINK THERE WILL BE ANY MORE SNOW THAT WOULD IMPACT CATEGORY...AND HAVE SIMILAR THOUGHTS ON KHUF. WITH TIME HEIGHTS SHOWING SOME LOW LEVEL MOISTURE HANGING AROUND THROUGH THE DAY TOMORROW AS THE HIGH BUILDS TOWARD THE AREA...COULD SEE SOME MVFR STRATOCU DEVELOP WITH AFTERNOON SUNSHINE. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 9 AM EST THURSDAY FOR INZ061>065- 067>072. && $$ SYNOPSIS...NIELD NEAR TERM...NIELD SHORT TERM...NIELD LONG TERM...JK AVIATION...CP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
110 PM EST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 1038 AM EST TUE MAR 3 2015 AREAS OF FREEZING RAIN AND SLEET WILL CHANGEOVER TO LIGHT RAIN AND DRIZZLE THIS AFTERNOON AND EVENING IN ADVANCE OF A COLD FRONT. LIGHT ICE ACCUMULATIONS WILL CREATE SLICK SPOTS ON UNTREATED ROADS AND SIDEWALKS INTO THE EARLY AFTERNOON. TEMPERATURES BY LATE THIS AFTERNOON AND EVENING SHOULD RECOVER INTO THE MID TO UPPER 30S BEFORE FALLING BACK INTO THE UPPER TEENS AND 20S LATER TONIGHT INTO WEDNESDAY BEHIND A COLD FRONT. && .UPDATE... ISSUED AT 1120 AM EST TUE MAR 3 2015 3 HR EXTENSION OF ADVISORY PRIMARILY FOR FREEZING RAIN PERSISTING ACRS FAR NORTHERN/NORTHEAST CWA. SHALLOW INVERSION AFFORDING SLOWER RECESSION ACRS DEEPER SNOWPACK/MORE DEEPLY ROOTED ANTECEDENT ARCTIC AIRMASS. HOWEVER...WITH EARLY MARCH SUN PEAKING HIR ALTITUDES...EXPECT EVENTUAL MIXOUT ACRS ENTIRE CWA TO AOA FZG. MAR 3 PEAK SOLAR ALTITUDE AT KASW FOR EXAMPLE IS 42 DEGREES WHICH SHOULD ALSO AFFORD RAPID IMPROVEMENT OF EVEN UNTREATED SFCS IN ALL BUT INSOLATION SHELTERED LOCALES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 438 AM EST TUE MAR 3 2015 RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS MORNING WHERE SFC TEMPS IN THE MID 20S. PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z. ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3 TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING. THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING. POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON. CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN THIS MORNING. SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z. HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2 INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL WITHIN GOING ADVISORY WHICH WILL CONTINUE. MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 438 AM EST TUE MAR 3 2015 STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE COLDEST HIGH AT FT WAYNE FOR THE DATE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 109 PM EST TUE MAR 3 2015 AMPLE AFTN SUN ANGLE AND WARM AIR ADVECTION SHOULD ALLOW PTYPE TO CHANGE TO ALL LIQUID BY 19 UTC AT KFWA. CONTD MOISTURE FLUX FROM SLOW MELTING SNOWPACK AND TOP/DOWN SATURATION TO LIKELY LEND LONG DURATION IFR CIGS ACRS NRN INDIANA THROUGH AT LEAST MID.LATE EAVENING. FRONTAL BOUNDARY CRTNLY ACRS WI INTO FAR ERN IA TO PUSH EWD THROUGH REGION IN 01-03 UTC TIMEFRAME AND SHOULD LEAD TO MIXOUT INVERSION TRAPPED MOISTURE FOR IMPROVED VSBYS/CIGS THROUGH REMAINDER OF FCST PD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR INZ003>005-008-009-012>018-020-022>027-032>034. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR INZ006- 007. MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ078>081. OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ004- 005-015-016-024-025. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ001- 002. LM...NONE. && $$ UPDATE...MURPHY SYNOPSIS...STEINWEDEL SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...MURPHY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1123 AM EST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 1038 AM EST TUE MAR 3 2015 AREAS OF FREEZING RAIN AND SLEET WILL CHANGEOVER TO LIGHT RAIN AND DRIZZLE THIS AFTERNOON AND EVENING IN ADVANCE OF A COLD FRONT. LIGHT ICE ACCUMULATIONS WILL CREATE SLICK SPOTS ON UNTREATED ROADS AND SIDEWALKS INTO THE EARLY AFTERNOON. TEMPERATURES BY LATE THIS AFTERNOON AND EVENING SHOULD RECOVER INTO THE MID TO UPPER 30S BEFORE FALLING BACK INTO THE UPPER TEENS AND 20S LATER TONIGHT INTO WEDNESDAY BEHIND A COLD FRONT. && .UPDATE... ISSUED AT 1120 AM EST TUE MAR 3 2015 3 HR EXTENSION OF ADVISORY PRIMARILY FOR FREEZING RAIN PERSISTING ACRS FAR NORTHERN/NORTHEAST CWA. SHALLOW INVERSION AFFORDING SLOWER RECESSION ACRS DEEPER SNOWPACK/MORE DEEPLY ROOTED ANTECEDENT ARCTIC AIRMASS. HOWEVER...WITH EARLY MARCH SUN PEAKING HIR ALTITUDES...EXPECT EVENTUAL MIXOUT ACRS ENTIRE CWA TO AOA FZG. MAR 3 PEAK SOLAR ALTITUDE AT KASW FOR EXAMPLE IS 42 DEGREES WHICH SHOULD ALSO AFFORD RAPID IMPROVEMENT OF EVEN UNTREATED SFCS IN ALL BUT INSOLATION SHELTERED LOCALES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 438 AM EST TUE MAR 3 2015 RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS MORNING WHERE SFC TEMPS IN THE MID 20S. PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z. ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3 TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING. THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING. POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON. CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN THIS MORNING. SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z. HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2 INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL WITHIN GOING ADVISORY WHICH WILL CONTINUE. MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 438 AM EST TUE MAR 3 2015 STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE COLDEST HIGH AT FT WAYNE FOR THE DATE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 639 AM EST TUE MAR 3 2015 FIRST BATCH OF MIXED PCPN COMING THROUGH THIS MORNING. BRIEF LULL POSSIBLE AS RADAR RETURNS WEAKEN IMMEDIATELY BEHIND. HOWEVER...UPSTREAM RADARS SHOWING LIGHT RETURNS DEVELOPING AND EXPECT THESE TO MOVE BACK IN SHORTLY. CIGS AND VIS LOWERING UPSTREAM AS WELL SO EXPECT THIS TREND LATER TODAY. LIGHT ICING STILL EXPECTED THROUGH THE MORNING THOUGH PCPN AMOUNTS MAY BE LESS THAN PREVIOUSLY ANTICIPATED. HOWEVER...LIGHT GLAZE OF AT LEAST A FEW HUNDREDTHS EXPECTED WHICH WILL CAUSE PROBLEMS. TEMPS STILL EXPECTED ABOVE FREEZING BY AFTERNOON WITH RAIN. CHANCE OF LIGHT SNOW TONIGHT AND STILL POSSIBILITY OF LIGHT FZDZ BUT TOO LOW OF A CHANCE TO MENTION AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR INZ003>005-008-009-012>018-020-022>027-032>034. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR INZ006- 007. MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ078>081. OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ004- 005-015-016-024-025. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ001- 002. LM...NONE. && $$ UPDATE...MURPHY SYNOPSIS...STEINWEDEL SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1039 AM EST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 1038 AM EST TUE MAR 3 2015 AREAS OF FREEZING RAIN AND SLEET WILL CHANGEOVER TO LIGHT RAIN AND DRIZZLE THIS AFTERNOON AND EVENING IN ADVANCE OF A COLD FRONT. LIGHT ICE ACCUMULATIONS WILL CREATE SLICK SPOTS ON UNTREATED ROADS AND SIDEWALKS INTO THE EARLY AFTERNOON. TEMPERATURES BY LATE THIS AFTERNOON AND EVENING SHOULD RECOVER INTO THE MID TO UPPER 30S BEFORE FALLING BACK INTO THE UPPER TEENS AND 20S LATER TONIGHT INTO WEDNESDAY BEHIND A COLD FRONT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 438 AM EST TUE MAR 3 2015 RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS MORNING WHERE SFC TEMPS IN THE MID 20S. PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z. ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3 TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING. THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING. POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON. CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN THIS MORNING. SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z. HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2 INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL WITHIN GOING ADVISORY WHICH WILL CONTINUE. MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 438 AM EST TUE MAR 3 2015 STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE COLDEST HIGH AT FT WAYNE FOR THE DATE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 639 AM EST TUE MAR 3 2015 FIRST BATCH OF MIXED PCPN COMING THROUGH THIS MORNING. BRIEF LULL POSSIBLE AS RADAR RETURNS WEAKEN IMMEDIATELY BEHIND. HOWEVER...UPSTREAM RADARS SHOWING LIGHT RETURNS DEVELOPING AND EXPECT THESE TO MOVE BACK IN SHORTLY. CIGS AND VIS LOWERING UPSTREAM AS WELL SO EXPECT THIS TREND LATER TODAY. LIGHT ICING STILL EXPECTED THROUGH THE MORNING THOUGH PCPN AMOUNTS MAY BE LESS THAN PREVIOUSLY ANTICIPATED. HOWEVER...LIGHT GLAZE OF AT LEAST A FEW HUNDREDTHS EXPECTED WHICH WILL CAUSE PROBLEMS. TEMPS STILL EXPECTED ABOVE FREEZING BY AFTERNOON WITH RAIN. CHANCE OF LIGHT SNOW TONIGHT AND STILL POSSIBILITY OF LIGHT FZDZ BUT TOO LOW OF A CHANCE TO MENTION AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR INZ003>009-012>018-020-022>027-032>034. MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077>081. OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001- 002-004-005-015-016-024-025. LM...NONE. && $$ SYNOPSIS...STEINWEDEL SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
644 AM EST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 440 AM EST MON MAR 2 2015 A WINTRY MIX OF PRECIPITATION WILL SPREAD ACROSS THE AREA THIS MORNING. LIGHT SNOW...SLEET AND FREEZING RAIN WILL TRANSITION TO JUST FREEZING RAIN. AS TEMPERATURES RISE ABOVE FREEZING LATE THIS MORNING AND EARLY THIS AFTERNOON...PRECIPITATION WILL THEN BE IN THE FORM OF JUST RAIN. LIGHT ACCUMULATIONS OF SNOW...SLEET AND ICE ARE POSSIBLE WHICH WILL MAKE CONDITIONS SLICK THIS MORNING. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 30S NORTH TO LOWER AND MIDDLE 40S SOUTH. A COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT. LOWS WILL DROP BACK INTO THE TEENS AND 20S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 438 AM EST TUE MAR 3 2015 RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS MORNING WHERE SFC TEMPS IN THE MID 20S. PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z. ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3 TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING. THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING. POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON. CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN THIS MORNING. SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z. HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2 INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL WITHIN GOING ADVISORY WHICH WILL CONTINUE. MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 438 AM EST TUE MAR 3 2015 STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE COLDEST HIGH AT FT WAYNE FOR THE DATE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 639 AM EST TUE MAR 3 2015 FIRST BATCH OF MIXED PCPN COMING THROUGH THIS MORNING. BRIEF LULL POSSIBLE AS RADAR RETURNS WEAKEN IMMEDIATELY BEHIND. HOWEVER...UPSTREAM RADARS SHOWING LIGHT RETURNS DEVELOPING AND EXPECT THESE TO MOVE BACK IN SHORTLY. CIGS AND VIS LOWERING UPSTREAM AS WELL SO EXPECT THIS TREND LATER TODAY. LIGHT ICING STILL EXPECTED THROUGH THE MORNING THOUGH PCPN AMOUNTS MAY BE LESS THAN PREVIOUSLY ANTICIPATED. HOWEVER...LIGHT GLAZE OF AT LEAST A FEW HUNDREDTHS EXPECTED WHICH WILL CAUSE PROBLEMS. TEMPS STILL EXPECTED ABOVE FREEZING BY AFTERNOON WITH RAIN. CHANCE OF LIGHT SNOW TONIGHT AND STILL POSSIBILITY OF LIGHT FZDZ BUT TOO LOW OF A CHANCE TO MENTION AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR INZ003>009-012>018-020-022>027-032>034. MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077>081. OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001- 002-004-005-015-016-024-025. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
443 AM EST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 440 AM EST MON MAR 2 2015 A WINTRY MIX OF PRECIPITATION WILL SPREAD ACROSS THE AREA THIS MORNING. LIGHT SNOW...SLEET AND FREEZING RAIN WILL TRANSITION TO JUST FREEZING RAIN. AS TEMPERATURES RISE ABOVE FREEZING LATE THIS MORNING AND EARLY THIS AFTERNOON...PRECIPITATION WILL THEN BE IN THE FORM OF JUST RAIN. LIGHT ACCUMULATIONS OF SNOW...SLEET AND ICE ARE POSSIBLE WHICH WILL MAKE CONDITIONS SLICK THIS MORNING. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 30S NORTH TO LOWER AND MIDDLE 40S SOUTH. A COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT. LOWS WILL DROP BACK INTO THE TEENS AND 20S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 438 AM EST TUE MAR 3 2015 RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS MORNING WHERE SFC TEMPS IN THE MID 20S. PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z. ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3 TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING. THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING. POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON. CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN THIS MORNING. SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z. HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2 INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL WITHIN GOING ADVISORY WHICH WILL CONTINUE. MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 438 AM EST TUE MAR 3 2015 STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE COLDEST HIGH AT FT WAYNE FOR THE DATE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1232 AM EST TUE MAR 3 2015 PRIOR TAF FORECASTS ON TRACK AND CONTINUED TREND WITH THIS PACKAGE. SLIGHT ADJUSTMENTS MADE TO PCPN TIMING BASED ON LATEST 00Z MODELS AND 03Z HIRES MODELS WHICH CONTINUE TO SLOW ONSET OF PCPN. THIS IN LARGE PART DUE TO VERY DRY WEDGE IN THE LOWER LEVELS WHICH WILL AID IN EVAPORATION OF FALLING PCPN UNTIL DEEPER MOISTURE SURGE ARRIVES AROUND 12-15Z. THIS DRY WEDGE ALSO UNDER DEEP LAYER OF SUPERCOOLED WATER. THIS SUGGEST EVAP COOLING PROCESSES MAY ALSO ALLOW SOME OF THIS WATER TO FREEZE AND FALL AS SLEET ALONG WITH SNOW AT ONSET. MOVED UP TIMING OF SLEET GIVEN THIS POSSIBLE SCENARIO. PCPN BECOMES FZRA FOR A FEW HOURS MID MORNING WITH WARM AIR ALOFT. THIS DEEPENS TO NEAR SFC AROUND 18-19Z WITH SFC TEMPS JUST BARELY ABOVE FREEZING FOR JUST RAIN IN AFTERNOON. CHANGE BACK TO LIGHT SNOW WITH COLD FRONT PASSAGE EARLY EVENING. A SLIGHT CHANCE FOR FZDZ THIS EVENING WITH DRYING ALOFT BUT FEW MODELS SHOW SOME CLOUD SEEDING SO WILL NOT INTRODUCE ANY MENTION INTO TAFS AT THIS TIME GIVEN SMALL PROBABILITY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR INZ003>009-012>018-020-022>027-032>034. MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077>081. OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001- 002-004-005-015-016-024-025. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
135 PM CST TUE MAR 3 2015 .UPDATE... ISSUED AT 133 PM CST TUE MAR 3 2015 COLD FRONT ARRIVING FASTER THAN FORECAST. AS SUCH HIGH TEMPERATURES WILL PEAK BETWEEN NOW AND 3 PM AND THEN START FALLING. AN UPDATE FOR LOWER HIGH TEMPERATURES WILL BE OUT SHORTLY. && .SYNOPSIS... ISSUED AT 252 AM CST TUE MAR 3 2015 STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 252 AM CST TUE MAR 3 2015 THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH 15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND 2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED. HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE BATTLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 252 AM CST TUE MAR 3 2015 MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST! AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES. GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND CHILLS THAT WILL REACH WIND CHILL CRITERIA. NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY. MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE CONFIDENCE ON A WARM UP NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1123 AM CST TUE MAR 3 2015 IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH 00Z/04 WITH AREAS OF DRIZZLE AS TEMPERATURES CLIMB ABOVE FREEZING. AFT 00Z/04 CONDITIONS WILL SLOWLY IMPROVE TO MVFR FOLLOWING THE PASSAGE OF A STRONG COLD FRONT. AFT 09Z/04 CONDITIONS WILL SLOWLY IMPROVE TO VFR. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...GIBBS AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1126 AM CST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 252 AM CST TUE MAR 3 2015 STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 252 AM CST TUE MAR 3 2015 THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH 15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND 2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED. HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE BATTLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 252 AM CST TUE MAR 3 2015 MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST! AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES. GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND CHILLS THAT WILL REACH WIND CHILL CRITERIA. NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY. MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE CONFIDENCE ON A WARM UP NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1123 AM CST TUE MAR 3 2015 IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH 00Z/04 WITH AREAS OF DRIZZLE AS TEMPERATURES CLIMB ABOVE FREEZING. AFT 00Z/04 CONDITIONS WILL SLOWLY IMPROVE TO MVFR FOLLOWING THE PASSAGE OF A STRONG COLD FRONT. AFT 09Z/04 CONDITIONS WILL SLOWLY IMPROVE TO VFR. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JOHNSON-JONES- KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-WASHINGTON. IL...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BUREAU-CARROLL- HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON- WHITESIDE. MO...NONE. && $$ SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...GIBBS AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
532 AM CST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 252 AM CST TUE MAR 3 2015 STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 252 AM CST TUE MAR 3 2015 THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH 15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND 2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED. HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE BATTLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 252 AM CST TUE MAR 3 2015 MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST! AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES. GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND CHILLS THAT WILL REACH WIND CHILL CRITERIA. NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY. MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE CONFIDENCE ON A WARM UP NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 524 AM CST TUE MAR 3 2015 FREEZING RAIN AND SNOW WILL FALL AT ALL LOCATIONS THROUGH AROUND 15Z...AT WHICH TIME THE PRECIPITATION SHOULD END. AS THE FREEZING RAIN AND SNOW END...TEMPERATURES WILL QUICKLY RISE TO THE MID TO UPPER 30S...ENDING THE FREEZING THREAT...AND HELPING TO IMPROVE REMAINING ICING CONDITIONS. SOUTH WINDS BRINGING IN THE MILD AIR WILL BLOW AROUND 15 TO 20 KTS THROUGH THE MORNING...BEFORE SWITCHING TO SOUTHWEST AT 15 KTS...THEN AS A COLD FRONT ARRIVES...NORTHWEST AT 18 TO 26 KTS THIS EVENING. IFR TO MVFR CIGS WILL CONTINUE THROUGH THE MORNING...BUT SHOULD IMPROVE ONCE SOUTHWESTERLY WINDS ESTABLISH THEMSELVES. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JOHNSON-JONES- KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-WASHINGTON. WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR DES MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN. IL...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BUREAU-CARROLL- HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON- WHITESIDE. WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR HANCOCK- HENDERSON-MCDONOUGH-WARREN. MO...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK- SCOTLAND. && $$ SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...GIBBS AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
311 AM CST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 252 AM CST TUE MAR 3 2015 STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 252 AM CST TUE MAR 3 2015 THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH 15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND 2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED. HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE BATTLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 252 AM CST TUE MAR 3 2015 MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST! AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES. GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND CHILLS THAT WILL REACH WIND CHILL CRITERIA. NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY. MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE CONFIDENCE ON A WARM UP NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1147 PM CST MON MAR 2 2015 LOW LEVEL WIND SHEAR IS STILL POSSIBLE OVERNIGHT INTO EARLY TUESDAY AM WITH STRENGTHENING LOW LEVEL JET. MODELS THOUGH VARY ON STRENGTH OF WINDS 1500-2000 FT AGL (30-40 KTS) AND WITH EXPECTED INCREASE IN SURFACE WINDS WITH SOME GUSTS HAVE CONTINUED TO LEAVE OUT MENTION ATTIM BUT CONTINUE TO MONITOR. OTHERWISE... OVERNIGHT AND TUESDAY AM EXPECT CONDITIONS TO DETERIORATE INTO MVFR TO POSSIBLY AREAS OF IFR WITH A SHOWERY WINTRY MIX OF PCPN ACROSS THE AREA. PCPN WILL BE MAINLY LIGHT WITH TYPES FAVORING MAINLY SLEET/ SNOW NORTH OF I-80 WITH FREEZING RAIN/SLEET TRANSITION TO RAIN SOUTH WHERE MINOR GLAZING OF ICE ACCUM POSSIBLE. PCPN TO DIMINISH IN COVERAGE BY LATE AM THROUGH MIDDAY WITH MVFR TO POSSIBLY AREAS OF IFR CONDITIONS CONTINUING THROUGH AFTN AHEAD OF A COLD FRONT WHICH WILL PASS THROUGH THE TERMINALS 19-23Z AND MAY BE ACCOMPANIED BY FLURRIES OR BRIEF PERIOD OF LIGHT SNOW ESPECIALLY NORTHEAST IA. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JOHNSON-JONES- KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-WASHINGTON. WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR DES MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN. IL...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BUREAU-CARROLL- HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON- WHITESIDE. WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR HANCOCK- HENDERSON-MCDONOUGH-WARREN. MO...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK- SCOTLAND. && $$ SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...GIBBS AVIATION...05
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
245 PM CST TUE MAR 3 2015 ...UPDATE TO SHORT TERM... .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 245 PM CST TUE MAR 3 2015 MOST OF THE ACTION IS AFTER MIDNIGHT. IN THE MEANTIME, COLDER AIR WILL CONTINUE TO ADVECT IN FROM THE NORTHWEST AND NORTH. BY MIDNIGHT, THE THERMO PROFILE SHOULD BE COLD ENOUGH FOR SNOW. A FORECAST SOUNDING DID SHOW 0.5C WARM TONGUE FOR MEDICINE LODGE BETWEEN 00-06Z, BUT FOR RIGHT NOW, WILL KEEP PRECIPITATION TYPE ALL SNOW THROUGH THE SHORT TERM DOMAIN. SPEAKING OF, HAVE RELIED ON THE MESOSCALE MODELS LIKE THE WRF AND NAM, WHICH SHOWS A MESOSCALE SNOW BAND MOVING ACROSS THE REGION. FROM THE METEOROLOGICAL COOKBOOK... 290-300K ISENTROPIC LIFT, 700-HPA OMEGA AND BAROCLINIC BAND, 800-600-HPA FRONTOGENESIS DO GIVE SUPPORT TO THE PHYSICAL REASONING AS WHY THE MODELS ARE BEHAVING AS SUCH. IT SHOULD BE NOTED THAT THE WRF-NMM ACTUALLY SHOWS A STRONGER BAND AND HIGHER SNOW AMOUNTS. WILL GO IN THE MIDDLE OF THE ROAD FOR NOW. HAVE A 2-4" BAND OF SNOW ROUGHLY ALONG THE HIGHWAY 56 CORRIDOR AS WELL AS A 50 MILE BUFFER ZONE SURROUNDING IT. HAVE THE LOWEST CONFIDENCE FARTHER NORTH TOWARDS HAYS. THE RAP SHOWS THE FRONTO BAND STRONGER IN THIS AREA AND HAS HIGH SNOW AMOUNTS. WILL LET THE MID SHIFT ALONG WITH 00Z GUIDANCE SPLIT THAT DETAIL. HAVE ISSUED A WINTER WEATHER ADVISORY FOR MUCH OF THE FORECAST AREA EXCEPT THE NORTHWEST AND NORTHERN ZONES. THE 18Z NAM HAS SHIFTED THE HEAVIEST SNOW BAND ABOUT 20 MILES NORTH FROM WHAT I HAVE IT NOW. AGAIN, WITH INCREASED POPS/SNOWFALL AMOUNTS, FEEL THE POSITIVE TREND COVERS THE SITUATION FOR NOW. THAT BEING SAID, DON`T BE SURPRISED IF THERE ARE TWEAKS BETWEEN NOW AND THE STORM EVENT AS CONFIDENCE ON MESOSCALE EVOLUTION INCREASES. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 209 PM CST TUE MAR 3 2015 FOR WEDNESDAY NIGHT...ANY LINGERING LIGHT PRECIPITATION NEAR THE OKLAHOMA BORDER WILL END DURING THE EVENING AS AN UPPER LEVEL TROUGH CROSSES WESTERN KANSAS. SUBSIDENCE DEVELOPING BEHIND THIS UPPER TROUGH SHOULD BRING SOME CLEARING SKIES DURING THE OVERNIGHT HOURS. WINDS WILL BE LIGHT BASED ON WHERE THE SURFACE RIDGE AXIS WILL BE LOCATED EARLY THURSDAY MORNING ALSO. GIVEN CLEAR SKIES, LIGHT WINDS AND EXPECTED SNOW COVER WILL BE STAY SEVERAL DEGREES BELOW THE COOLER GUIDANCE FOR LOWS, ESPECIALLY EAST OF DODGE CITY. AN UPPER LEVEL RIDGE AXIS WILL BECOME ESTABLISHED OVER THE WEST COAST LATE WEEK AND A NORTHWEST FLOW IS EXPECTED ACROSS THE CENTRAL HIGH PLAINS THROUGH THE WEEKEND PERIOD. THE WARMING TREND CURRENTLY ADVERTISED IN THE PREVIOUS FORECAST STILL LOOKS ON TRACK GIVEN THIS NORTHWEST DOWNSLOPE FLOW. TOWARDS SUNDAY AN UPPER LEVEL DISTURBANCE EMBEDDED IN THIS NORTHWEST WILL CROSS THE NORTHERN PLAINS WHICH WILL BRING ANOTHER COLD FRONT INTO WESTERN KANSAS. AT THIS TIME NOT MUCH IN THE WAY OF COLDER AIR IS EXPECTED TO RETURN TO WESTERN KANSAS BEHIND THIS FRONT. PRECIPITATION CHANCES APPEAR SMALL LATE WEEK INTO EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1108 AM CST TUE MAR 3 2015 GUSTY NORTH/NORTHEAST WINDS WILL GRADUALLY SUBSIDE TO 10 TO 15 KNOTS BY 00Z WEDNESDAY AS A SURFACE RIDGE AXIS BUILDS INTO WESTERN KANSAS. A BRIEF PERIOD OF LOW MVFR CEILINGS WILL BE POSSIBLE AT GCK AND DDC BETWEEN 18Z AND 21Z BASED ON LATEST HRRR. TONIGHT VFR CEILINGS WILL GRADUALLY LOWER THIS EVENING AS MOISTURE AND FORCING IMPROVES IN THE 800MB TO 600MB LEVEL. LOW VFR CONDITIONS WILL THEN GIVE WAY TO MVFR AND IFR CEILINGS BETWEEN 06Z AND 12Z WEDNESDAY AS THE LOWER LEVELS SATURATE AND LIGHT SNOW DEVELOPS, ESPECIALLY AT GCK AND DDC. NORTHEASTERLY WINDS WILL ALSO BE INCREASING AFTER MIDNIGHT INTO THE 15 TO 20 KNOT RANGE. && .PRELIMINARY POINT TEMPS/POPS... DDC 16 24 7 38 / 80 80 10 0 GCK 15 24 6 38 / 60 60 10 0 EHA 16 23 10 39 / 70 70 10 0 LBL 17 24 9 38 / 80 80 10 0 HYS 15 28 6 40 / 50 50 0 0 P28 19 25 9 39 / 80 80 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST WEDNESDAY FOR KSZ045-046-062>066-074>081-084>090. && $$ SHORT TERM...SUGDEN LONG TERM...BURGERT AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1042 PM MST MON MAR 2 2015 .UPDATE... ISSUED AT 551 PM MST MON MAR 2 2015 JUST COMPLETED AN UPDATE. MODELS ARE NOT CATCHING THE FULL EXTENT OF THE FOG. FOG HAS ALREADY DEVELOPED/ADVECTED INTO MOST LOCATIONS IN THE WESTERN HALF OF THE FORECAST AREA. THIS IS FASTER AND FURTHER EAST THAN THE MODEL DEPICTION. THE NAM LOOKS TO BE CAPTURING THIS THE BEST. SO USED A BLEND OF REALITY AND THE LATEST NAM TO INCREASE THE EXTENT OF THE FOG. DAY SHIFT HAD SOME CONCERN ABOUT THE FOG BECOMING DENSE BUT WAS THINKING THE WIND/MIXING WOULD PREVENT THAT. CURRENTLY THE NAM... HRRR AND RAP ARE INDICATING DENSE FOG POSSIBLE FOR LOCATIONS ALONG THE COLORADO BORDER. WHAT COMPLICATES THE EXTENT OF THE FOG AND HOW LONG IT COULD STAY DENSE IS THE MODEL DIFFERENCE IN THE SPEED THEY SWITCH THE WINDS TO A WESTERLY DIRECTION AS THEY BRING IN DRIER AIR. BASED ON THE STRENGTH OF THE SURFACE TROUGH IT IS POSSIBLE THE SLOWEST SOLUTIONS COULD BE RIGHT. THIS WOULD ALLOW A LONGER PERIOD OF DENSE FOG. WILL KEEP MONITOR AND WAIT FOR THE LATEST MODEL DATA TO SEE IF A DENSE FOG ADVISORY MAY BE NEEDED. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 200 PM MST MON MAR 2 2015 AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE REGION ARE MOSTLY CLOUDY TO OVERCAST. WINDS ARE SOUTH AT 15 TO 25 MPH...GUSTING 35 MPH. TEMPERATURES RANGED FROM THE LOW 30S WHERE STRATUS PERSISTS TO THE UPPER 30S WHERE CLOUD BREAKS ARE NOTED. AT THE SURFACE...LOW PRESSURE IS LOCATED ALONG THE FRONT RANGE. ALOFT...A WEAK SHORTWAVE AND MOISTURE ADVECTION IS MOVING IN FROM THE SOUTHWEST. THIS DISTURBANCE IS EJECTING AHEAD OF A DEEP UPPER LOW OVER CALIFORNIA. FOR THIS AFTERNOON/TONIGHT...MANY FORECAST COMPLICATIONS HAVE LEAD TO LOWER CONFIDENCE THAN NORMAL. SEVERAL FACTORS ARE WORKING FOR PRECIPITATION/FOG WHILE THERE ARE ALSO COMPETING FACTORS THAT COULD NEGATE ANY POTENTIAL PRECIP/FOG THREAT. FIRST...BEGINNING WITH PRECIPITATION CHANCES...A STRONG LOW LEVEL JET DEVELOPS THIS EVENING. THIS RESULTS IN FURTHER WARM/MOIST AIR ADVECTION. IN ADDITION...SLIGHT LIFT APPLIED BY PASSING SHORTWAVE MAY ALLOW FOR SOME DRIZZLE/FREEZING DRIZZLE TO DEVELOP...MAINLY EAST OF HIGHWAY 25. HOWEVER...CONDENSATION PRESSURE DEFICITS INDICATE THAT MOST DRIZZLE/FREEZING DRIZZLE AND ANY HEAVIER PRECIPITATION REMAINS SOUTHEAST. IN ADDITION...ONLY A SHALLOW LAYER OF MOISTURE IS PRESENT IN THE ATMOSPHERIC COLUMN SO NOT SURE IF THERE IS EVEN ENOUGH MOISTURE TO PRECIPITATE. MOST LIKELY...PERSISTENT STRATUS CONTINUES THROUGH THE NIGHT WITH A FEW SPORADIC OBSERVATIONS OF DRIZZLE/FREEZING DRIZZLE. ANY PRECIPITATION EXITS TO THE EAST BY SUNRISE. WITH COLD GROUND/ROAD TEMPERATURES...IT IS POSSIBLE THAT DRIZZLE FREEZES ON CONTACT SO CAN NOT COMPLETELY RULE OUT A PATCHY GLAZE. A COMPLICATING FACTOR TO THIS IS THE STRONG WARM AIR ADVECTION. TEMPERATURES MAY REMAIN ABOVE FREEZING THROUGHOUT THE NIGHT. THIS WOULD LIKELY ELIMINATE ANY THREAT OF ICE. AS FOR THE FOG THREAT...SEVERAL HIGH RESOLUTION MODELS CONTINUE TO INDICATE FOG DEVELOPMENT OVER EAST COLORADO SHORTLY AFTER SUNSET WITH FOG ADVECTING EAST DURING THE EVENING. GUIDANCE INDICATES THAT FOG MAY BE DENSE GIVEN THE AMOUNT OF MOISTURE ADVECTION INITIALLY. HOWEVER...GUSTY SOUTH WINDS PERSIST THROUGH THE NIGHT. THIS RESTRICTS HOW LOW VISIBILITIES DROP AND WOULD LEAD TO MORE STRATUS AND LIGHT FOG OBSERVATIONS THAN DENSE FOG. HAVE NOT MENTIONED DENSE FOG BUT DID MENTION PATCHY/AREAS OF FOG WHERE OCCURRENCE IS MOST LIKELY. FOG DIMINISHES IN DENSITY/COVERAGE AFTER MIDNIGHT AS DRIER AIR ADVECTS IN FROM THE SOUTHWEST. IT IS SOMEWHAT UNUSUAL THAT VISIBILITIES IMPROVE BEFORE SUNRISE BUT THIS SHOULD BE ONE OF THOSE CASES WHERE IT OCCURS. DURING THE DAY TOMORROW...THE NEXT DISTURBANCE BEGINS TO PUSH IN FROM THE WEST. IN ADDITION...A STRONG COLD FRONT WILL PUSH THROUGH DURING THE MORNING. BEHIND THE COLD FRONT...GUSTY NORTHWEST WINDS ARE LIKELY WITH GUIDANCE INDICATING PRESSURE RISES ON THE ORDER OF 10-15 MBS IN 6 HOURS. PRECIPITATION CHANCES LOOK MEAGER UNTIL BETTER FORCING ARRIVES LATER IN THE AFTERNOON BUT CAN`T RULE OUT A FEW FLURRIES ALONG AND JUST BEHIND THE FRONT. HIGH TEMPERATURES SHOULD BE REACHED DURING THE MORNING WITH FALLING TEMPS THROUGH REMAINDER OF THE DAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 200 PM MST MON MAR 2 2015 THE MAIN FORECAST CONCERNS THROUGH THIS PERIOD ARE THE POSSIBILITY OF SNOW TUESDAY NIGHT INTO WEDNESDAY MORNING AND THE CONTINUED COLD TEMPERATURES. THE THROUGH ALOFT OVER THE WESTERN UNITED STATES FINALLY SWEEPS EAST OF THE ROCKIES AND ACROSS THE CENTRAL HIGH PLAINS REGION WITH A COLD FRONT PUSHING SOUTH ACROSS THE FORECAST AREA TUESDAY NIGHT. EXPECT SNOW TO DEVELOP ALONG THE FRONT AS IT MOVES SOUTH WITH SNOW DIMINISHING FROM NORTH TO SOUTH WEDNESDAY MORNING. EXPECT 1-2 INCHES AT MOST OVER EASTERN COLORADO WITH AMOUNTS TAPERING OFF TO LESS THAN ONE INCH FURTHER EAST. IN ADDITION TO THE SNOW...10-15 MPH NORTH WINDS BEHIND THE FRONT ON WEDNESDAY MORNING ALONG WITH LOW TEMPERATURES IN THE SINGLE DIGITS ABOVE ZERO WILL PRODUCE WIND CHILLS IN THE -10 TO -15 DEGREE RANGE ACROSS THE FAR WESTERN PORTIONS OF THE FORECAST AREA. NO HIGHLIGHTS ARE CURRENTLY WARRANTED FOR EITHER THE SNOW OR THE COLD WIND CHILLS AT THIS POINT...BUT MAY END UP MENTIONING THEM IN THE HWO TO MAINTAIN SOME CONSISTENCY. SIGNIFICANT WARMING TAKES PLACE OVER THE REMAINDER OF THE FORECAST PERIOD AS TEMPERATURES COME UP TO NEAR NORMAL ON THURSDAY AND REMAIN ABOVE NORMAL FOR FRIDAY THROUGH MONDAY. BOTH THE ECMWF AND GFS AMPLIFY THE RIDGE OVER THE WESTERN U.S. THROUGH FRIDAY WITH MAINLY NORTHWEST FLOW BEING MAINTAINED ACROSS THE FORECAST AREA. THE GFS AND ECMWF BEGIN TO DIVERGE OVER THE WEEKEND WITH THE GFS PLACING THE RIDGE OVER THE ROCKIES WHILE THE ECMWF RETROGRADES THE RIDGE OVER THE WEST COAST. THE PATTERN FLATTENS AND BECOMES MORE OUT OF PHASE BETWEEN MODELS BY TUESDAY...BUT THE END RESULT IS THE CENTRAL HIGH PLAINS REGION REMAINS WARMER THAN AVERAGE AND DRY INTO THE BEGINNING OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1035 PM MST MON MAR 2 2015 MODELS ARE NOW REVERSING COURSE ON NOT ONLY FOG BUT STRATUS. MODELS HAVE BEEN HAVING A VERY HARD TIME THE LAST FEW DAYS IN RESOLVING THE LOW LEVEL MOISTURE. CONFIDENCE IS LOW RIGHT NOW. CONDITIONS HAVE BECOME VFR AT KGLD. PER SATELLITE AND LATEST RAP/HRRR THAT MATCHES UP PRETTY WELL. SO UNTIL THE PASSAGE OF THE FRONT NEAR 14Z...CONDITIONS WILL BE VFR. AS THE FRONT MOVES THROUGH KGLD...MVFR CONDITIONS ARE EXPECTED TO BECOME MVFR FOR ABOUT 4 TO 5 HOURS BEFORE BECOME VFR AGAIN. TOWARD THE END OF THE PERIOD...SNOW IS EXPECTED TO START MOVING NEAR KGLD. SO AT THIS TIME JUST PUT VCSH WITH MVFR CEILINGS. GUSTY NORTHERLY WINDS ARE EXPECTED FOR THE MAJORITY OF THE DAY. FOR KMCK...MVFR CONDITIONS ARE EXPECTED UNTIL NEAR 12Z WHEN THEY BRIEFLY BECOME VFR RIGHT BEFORE THE FRONT COMES THROUGH. JUST LIKE KGLD MVFR CONDITIONS ARE EXPECTED FOR ABOUT 4 TO 5 HOURS AFTER THE FRONT COMES THROUGH. AROUND 19Z VFR CONDITIONS ARE EXPECTED UNTIL TOWARD THE END OF THE PERIOD. AT THAT TIME...MVFR CONDITIONS ARE EXPECTED AS LIGHT SNOW...DEPICTED BY VCSH...MOVES INTO THE AREA. GUSTY NORTHERLY WINDS WILL PREVAIL DURING THE DAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...RRH LONG TERM...LOCKHART AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS JACKSON KY
405 PM EST TUE MAR 3 2015 .UPDATE... ISSUED AT 120 PM EST TUE MAR 3 2015 ISOLATED TO SCATTERED SHOWERS CONTINUED ACROSS A GOOD PORTION OF KY...MAINLY ACROSS OUR NORTHERN CWA. STILL HAVE MENTION OF CHANCE POPS...INCLUDING THUNDER...FOR THE REST OF THE AFTERNOON. MAY END UP TRENDING BACK ON THIS A BIT GIVEN THE ONGOING RADAR TRENDS. HOWEVER...CONDITIONS ARE RIPE FOR ANY SHOWERS TO BEGIN DEVELOPING AT ANY TIME...SO MAY END UP KEEPING WITH THE ONGOING CHANCES TO BE SAFE. UPDATED THE FORECAST /ZFP AND SAF/ TO TAKE OUT ANY MORNING WORDING FOR ISOLATED SHOWERS. UPDATE ISSUED AT 1026 AM EST TUE MAR 3 2015 LATEST RADAR TRENDS CONTINUE TO MOVE THE HEAVIEST SHOWERS ALONG NORTH CENTRAL KY AND THEN NORTH OF THE CWA. EXPECT THINGS TO EVENTUALLY START SHIFTING SOUTHWARD...BUT THE LATEST HRRR AND NAM12 ARE NOT SHOWING THIS TRANSITION UNTIL THIS EVENING /CLOSER TO 3Z/...A LITTLE LATER THAN ORIGINALLY FORECASTED/ANTICIPATED. AS SUCH...GIVEN THE LATEST RADAR TRENDS AND GOOD INITIATION OF THESE HI RES MODELS...WENT AHEAD AND DROPPED TO ONLY SLIGHT CHANCES ACROSS THE SE CWA THROUGH THE MORNING...INCREASING TO CHANCES THROUGH THE REST OF THE DAY. BY THIS EVENING...HEAVIEST RAIN SHOULD BE MAKING IT INTO MUCH OF THE CWA...SO KEPT WITH A LIKELY/DEFINITE POP FROM THIS POINT ON. ALSO...LOADED IN THE LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE THE NEAR-TERM FORECAST FOR THESE PARAMETERS WAS WELL ON TRACK WITH THE CURRENT CONDITIONS. UPDATE ISSUED AT 850 AM EST TUE MAR 3 2015 QUICK UPDATE TO BRING GRIDS IN LINE WITH HOURLY OBS AND RADAR TRENDS. HAD SOME SPRINKLES THIS MORNING BUT NOTHING SIGNIFICANT WITH RESPECT TO LIGHT FREEZING DZ...RA. TEMPS ARE RISING ABOVE FREEZING NOW. WILL LET CURRENT SPS FOR PATCHY FREEZING DRIZZLE ACROSS PORTIONS OF THE AREA EXPIRE AT 9 AM. ALSO FRESHENED UP THE ZONES. OTHERWISE...NO OTHER CHANGES TO THE FORECAST PACKAGE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 358 AM EST TUE MAR 3 2015 A COMPLICATED WEATHER PATTERN SHAPING UP FOR EASTERN KENTUCKY THROUGH THE MIDDLE OF THE WEEK. THE FIRST FORECAST CONCERN WILL BE THE POTENTIAL FOR FREEZING DRIZZLE OR FREEZING RAIN EARLY THIS MORNING NORTH OF THE MOUNTAIN PARKWAY. THERE IS A SMALL CHANCE THAT SOME LIGHT PRECIPITATION WILL FALL INTO A LAYER OF SUBFREEZING AIR THAT IS CURRENTLY IN PLACE ACROSS THE NORTHERN HALF OF THE FORECAST AREA. THE ISSUE WITH THIS WILL BE WHETHER OR NOT THE PRECIP IS ABLE TO REACH THE GROUND BEFORE TEMPERATURES RISE ABOVE FREEZING. THIS SITUATION WILL CONTINUE TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL HOURS. IF SOME FREEZING PRECIP DOES DEVELOP...AN SPECIAL WEATHER STATEMENT WILL BE ISSUED TO DEAL WITH IT. THE SECOND CONCERN IN THE FIRST 36 HOURS OF THE FORECAST WILL BE HEAVY RAIN AND THE POTENTIAL FOR FLOODING ACROSS THE AREA. AT THIS TIME...THE FORECAST MODELS HAVE MOVED THE AXIS OF HEAVIEST PRECIPITATION TODAY SLIGHTLY NORTH OF WHERE IT WAS IN PREVIOUS RUNS. THE POP AND QPF FORECAST FOR TODAY WAS MODIFIED AS A RESULT TO ACCOUNT FOR THIS CHANGE. IT STILL APPEARS HIGHLY LIKELY THAT EASTERN KENTUCKY WILL EXPERIENCE A PERIOD OF MODERATE TO HEAVY RAIN BEGINNING LATE THIS AFTERNOON AND LASTING THROUGH THE END OF THE DAY ON WEDNESDAY. THERE MAY EVEN BE ENOUGH VERTICAL MOTION AND WIND ENERGY ALOFT TO FIRE OFF A FEW THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. AT THIS TIME...IT STILL APPEARS THAT 2 TO 3 INCHES OF RAIN WILL FALL ACROSS ALL OF EASTERN KENTUCKY. DUE TO RECENTLY MELTED SNOW...THE GROUND IS ALREADY COMPLETELY SATURATED ACROSS THE ENTIRE AREA...SO IT WILL NOT TAKE MUCH RAIN TO BEGIN CAUSING PROBLEMS. BASED ON CURRENT HYDRO FORECASTS...IT APPEARS THAT THE CUMBERLAND RIVER BASIN MAY EXPERIENCE THE MOST SIGNIFICANT FLOODING ISSUES. THERE WILL ALSO BE POINTS ALONG THE KENTUCKY BASIN THAT MAY SEE SIGNIFICANT FLOODING...SUCH AS AT RAVENNA. THE TEMPERATURES TODAY ARE STILL EXPECTED TO RISE ABOVE NORMAL ACROSS THE AREA...WITH HIGHS TOPPING OUT IN THE LOW TO MID 50S FOR THE ENTIRE AREA. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY EVEN APPROACH 60 IN THE STRONG SOUTHERLY FLOW THAT IS ON TAP FOR TODAY. THE END OF THE SHORT TERM PERIOD IS WHERE OUR SECOND AND PERHAPS MORE SERIOUS FORECAST CONCERN LIES. ONCE THE PREVIOUSLY MENTIONED COLD FRONT MOVES THROUGH THE AREA...VERY COLD AIR WILL FILTER INTO THE AREA BEHIND IT...AS WINDS SHIFT TO THE NORTH AND NORTHWEST. WITH A STRONG FEED OF GULF MOISTURE STILL ON TRACK TO OVERRIDE THE SLUGGISH COLD FRONT...SIGNIFICANT AMOUNTS OF PRECIPITATION ARE EXPECTED TO OCCUR. PRECIPITATION WILL GRADUALLY TRANSITION FROM RAIN TO A MIX OF RAIN...SLEET...AND SNOW ALONG AND NORTH OF THE I634 CORRIDOR WEDNESDAY AFTERNOON. THIS MIX OF PRECIPITATION IS FORECAST TO MOVE STEADILY EASTWARD ACROSS THE AREA BEHIND THE DEPARTING FRONT. AS MORE AND MORE COLD AIR MOVES IN...THE PRECIP WILL CHANGE OVER FROM A MESSY WINTRY MIX TO ALL SNOW BY AROUND 0Z THURSDAY. SOME LIGHT SNOW AND SLEET ACCUMULATIONS MAY OCCUR LATE WEDNESDAY IN OUR FAR NORTHWEST. THE CHALLENGE WITH THIS PART OF THE FORECAST WILL BE DETERMINING HOW STRONG THE WARM NOSE ALOFT WILL BE AT THE START OF THE EVENT. AT THIS TIME...THE NAM12 BY FAR HAS THE MOST WELL DEFINED LAYER OF WARM AIR AMONGST THE MODELS...WHICH WOULD LEAD TO MORE SLEET IN OUR NORTHER AND LESS SNOW. THE GFS AND ECMWF MODELS...ON THE OTHER HAND...ARE BOTH SHOWING A MUCH LESS WELL DEFINED WARM NOSE ALOFT AND THEREFORE MORE SNOW. FOR NOW HAVE DECIDED TO USE A BLEND OF THE TWO SOLUTIONS...GOING WITH A MIX OF SNOW AND SLEET TO START THE EVENT AND LEANING MORE TOWARD THE SNOWFALL AMOUNTS THE WWD FORECAST IS CURRENTLY PREDICTING. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 405 PM EST TUE MAR 3 2015 HIGH PRESSURE (AND QUIET WEATHER) WILL BE THE DOMINANT FEATURE BEGINNING LATE THURSDAY THROUGH THE REMAINDER OF THE EXTENDED PERIOD. TEMPS FRIDAY MORNING WILL DIP INTO THE SINGLE DIGITS... WITH A FEW SPOTS IN OUR NORTH POSSIBLY DROPPING BELOW 0 DEGREES... WHICH IS WELL BELOW NORMAL FOR MARCH AND NEAR RECORD LOWS. THE COLD SNAP APPEARS TO BE FAIRLY SHORT LIVED AS TEMPERATURES START MODERATING BACK TOWARDS SEASONABLE LEVELS BY THE WEEKEND...THOUGH THEY WILL GENERALLY REMAIN BELOW NORMAL. SOME LIGHT PRECIPITATION WILL BE POSSIBLE EARLY NEXT WEEK... LATE SUNDAY INTO MONDAY AND AGAIN EARLY TUESDAY MORNING. BUT WITH SIGNIFICANT MODEL DIFFERENCES ASSOCIATED WITH THE LATTER PART OF THE FORECAST HAVE MAINTAINED SLIGHT POPS DURING THOSE PERIODS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 137 PM EST TUE MAR 3 2015 SCT SHOWERS CONTINUE TO MOVE ACROSS NORTH CENTRAL KY...GENERALLY PUSHING JUST NORTH OF EASTERN KY...MISSING MOST OF THE TAF SITES. AS SUCH...TOOK OUT MENTION OF SHRA OR TSRA DIRECTLY IMPACTING THE TAF SITES THROUGH ABOUT 00Z...THOUGH SOME VCSH OR VCTS ARE STILL POSSIBLE. AFTER 0Z...EXPECTING PRECIP TO BEGIN INCREASING IN COVERAGE AND INTENSITY ACROSS KY. WITH INSTABILITY STILL IN PLACE /DUE TO A STRONG PUSH OF COLDER NORTHERLY AIR INTERACTING WITH MOIST SRLY FLOW OFF THE GULF OF MEXICO/...COULD SEE SOME LINGERING POTENTIAL FOR THUNDER THROUGH THE EVENING AS WELL. BY OVERNIGHT...WE WILL LOSE OUR INSTABILITY...BUT RAIN WILL REALLY TAKE HOLD. ALL MODELS ARE SHOWING TAF SITES GOING BELOW AIRPORT MINS THROUGH THE REMAINDER OF THE FORECAST PERIOD...WITH PERIODS OF VIS AND CIGS LIFR AND BELOW. && .JKL WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH THURSDAY EVENING FOR KYZ044-050>052-058>060- 068-069-079-080-083>088-104-106>120. WINTER STORM WARNING FROM 1 PM TO 10 PM EST WEDNESDAY FOR KYZ044- 050>052. WINTER STORM WARNING FROM 4 PM TO 10 PM EST WEDNESDAY FOR KYZ058>060-104-106-108-111. WINTER STORM WARNING FROM 7 PM TO 10 PM EST WEDNESDAY FOR KYZ068- 069-079-080-083>086-107-109-110-112>117-119-120. WINTER STORM WARNING FROM 10 PM WEDNESDAY TO 1 PM EST THURSDAY FOR KYZ087-088-118. && $$ UPDATE...JMW SHORT TERM...AR LONG TERM...JVM AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
138 PM EST TUE MAR 3 2015 .UPDATE... ISSUED AT 120 PM EST TUE MAR 3 2015 ISOLATED TO SCATTERED SHOWERS CONTINUED ACROSS A GOOD PORTION OF KY...MAINLY ACROSS OUR NORTHERN CWA. STILL HAVE MENTION OF CHANCE POPS...INCLUDING THUNDER...FOR THE REST OF THE AFTERNOON. MAY END UP TRENDING BACK ON THIS A BIT GIVEN THE ONGOING RADAR TRENDS. HOWEVER...CONDITIONS ARE RIPE FOR ANY SHOWERS TO BEGIN DEVELOPING AT ANY TIME...SO MAY END UP KEEPING WITH THE ONGOING CHANCES TO BE SAFE. UPDATED THE FORECAST /ZFP AND SAF/ TO TAKE OUT ANY MORNING WORDING FOR ISOLATED SHOWERS. UPDATE ISSUED AT 1026 AM EST TUE MAR 3 2015 LATEST RADAR TRENDS CONTINUE TO MOVE THE HEAVIEST SHOWERS ALONG NORTH CENTRAL KY AND THEN NORTH OF THE CWA. EXPECT THINGS TO EVENTUALLY START SHIFTING SOUTHWARD...BUT THE LATEST HRRR AND NAM12 ARE NOT SHOWING THIS TRANSITION UNTIL THIS EVENING /CLOSER TO 3Z/...A LITTLE LATER THAN ORIGINALLY FORECASTED/ANTICIPATED. AS SUCH...GIVEN THE LATEST RADAR TRENDS AND GOOD INITIATION OF THESE HI RES MODELS...WENT AHEAD AND DROPPED TO ONLY SLIGHT CHANCES ACROSS THE SE CWA THROUGH THE MORNING...INCREASING TO CHANCES THROUGH THE REST OF THE DAY. BY THIS EVENING...HEAVIEST RAIN SHOULD BE MAKING IT INTO MUCH OF THE CWA...SO KEPT WITH A LIKELY/DEFINITE POP FROM THIS POINT ON. ALSO...LOADED IN THE LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE THE NEAR-TERM FORECAST FOR THESE PARAMETERS WAS WELL ON TRACK WITH THE CURRENT CONDITIONS. UPDATE ISSUED AT 850 AM EST TUE MAR 3 2015 QUICK UPDATE TO BRING GRIDS IN LINE WITH HOURLY OBS AND RADAR TRENDS. HAD SOME SPRINKLES THIS MORNING BUT NOTHING SIGNIFICANT WITH RESPECT TO LIGHT FREEZING DZ...RA. TEMPS ARE RISING ABOVE FREEZING NOW. WILL LET CURRENT SPS FOR PATCHY FREEZING DRIZZLE ACROSS PORTIONS OF THE AREA EXPIRE AT 9 AM. ALSO FRESHENED UP THE ZONES. OTHERWISE...NO OTHER CHANGES TO THE FORECAST PACKAGE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 358 AM EST TUE MAR 3 2015 A COMPLICATED WEATHER PATTERN SHAPING UP FOR EASTERN KENTUCKY THROUGH THE MIDDLE OF THE WEEK. THE FIRST FORECAST CONCERN WILL BE THE POTENTIAL FOR FREEZING DRIZZLE OR FREEZING RAIN EARLY THIS MORNING NORTH OF THE MOUNTAIN PARKWAY. THERE IS A SMALL CHANCE THAT SOME LIGHT PRECIPITATION WILL FALL INTO A LAYER OF SUBFREEZING AIR THAT IS CURRENTLY IN PLACE ACROSS THE NORTHERN HALF OF THE FORECAST AREA. THE ISSUE WITH THIS WILL BE WHETHER OR NOT THE PRECIP IS ABLE TO REACH THE GROUND BEFORE TEMPERATURES RISE ABOVE FREEZING. THIS SITUATION WILL CONTINUE TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL HOURS. IF SOME FREEZING PRECIP DOES DEVELOP...AN SPECIAL WEATHER STATEMENT WILL BE ISSUED TO DEAL WITH IT. THE SECOND CONCERN IN THE FIRST 36 HOURS OF THE FORECAST WILL BE HEAVY RAIN AND THE POTENTIAL FOR FLOODING ACROSS THE AREA. AT THIS TIME...THE FORECAST MODELS HAVE MOVED THE AXIS OF HEAVIEST PRECIPITATION TODAY SLIGHTLY NORTH OF WHERE IT WAS IN PREVIOUS RUNS. THE POP AND QPF FORECAST FOR TODAY WAS MODIFIED AS A RESULT TO ACCOUNT FOR THIS CHANGE. IT STILL APPEARS HIGHLY LIKELY THAT EASTERN KENTUCKY WILL EXPERIENCE A PERIOD OF MODERATE TO HEAVY RAIN BEGINNING LATE THIS AFTERNOON AND LASTING THROUGH THE END OF THE DAY ON WEDNESDAY. THERE MAY EVEN BE ENOUGH VERTICAL MOTION AND WIND ENERGY ALOFT TO FIRE OFF A FEW THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. AT THIS TIME...IT STILL APPEARS THAT 2 TO 3 INCHES OF RAIN WILL FALL ACROSS ALL OF EASTERN KENTUCKY. DUE TO RECENTLY MELTED SNOW...THE GROUND IS ALREADY COMPLETELY SATURATED ACROSS THE ENTIRE AREA...SO IT WILL NOT TAKE MUCH RAIN TO BEGIN CAUSING PROBLEMS. BASED ON CURRENT HYDRO FORECASTS...IT APPEARS THAT THE CUMBERLAND RIVER BASIN MAY EXPERIENCE THE MOST SIGNIFICANT FLOODING ISSUES. THERE WILL ALSO BE POINTS ALONG THE KENTUCKY BASIN THAT MAY SEE SIGNIFICANT FLOODING...SUCH AS AT RAVENNA. THE TEMPERATURES TODAY ARE STILL EXPECTED TO RISE ABOVE NORMAL ACROSS THE AREA...WITH HIGHS TOPPING OUT IN THE LOW TO MID 50S FOR THE ENTIRE AREA. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY EVEN APPROACH 60 IN THE STRONG SOUTHERLY FLOW THAT IS ON TAP FOR TODAY. THE END OF THE SHORT TERM PERIOD IS WHERE OUR SECOND AND PERHAPS MORE SERIOUS FORECAST CONCERN LIES. ONCE THE PREVIOUSLY MENTIONED COLD FRONT MOVES THROUGH THE AREA...VERY COLD AIR WILL FILTER INTO THE AREA BEHIND IT...AS WINDS SHIFT TO THE NORTH AND NORTHWEST. WITH A STRONG FEED OF GULF MOISTURE STILL ON TRACK TO OVERRIDE THE SLUGGISH COLD FRONT...SIGNIFICANT AMOUNTS OF PRECIPITATION ARE EXPECTED TO OCCUR. PRECIPITATION WILL GRADUALLY TRANSITION FROM RAIN TO A MIX OF RAIN...SLEET...AND SNOW ALONG AND NORTH OF THE I634 CORRIDOR WEDNESDAY AFTERNOON. THIS MIX OF PRECIPITATION IS FORECAST TO MOVE STEADILY EASTWARD ACROSS THE AREA BEHIND THE DEPARTING FRONT. AS MORE AND MORE COLD AIR MOVES IN...THE PRECIP WILL CHANGE OVER FROM A MESSY WINTRY MIX TO ALL SNOW BY AROUND 0Z THURSDAY. SOME LIGHT SNOW AND SLEET ACCUMULATIONS MAY OCCUR LATE WEDNESDAY IN OUR FAR NORTHWEST. THE CHALLENGE WITH THIS PART OF THE FORECAST WILL BE DETERMINING HOW STRONG THE WARM NOSE ALOFT WILL BE AT THE START OF THE EVENT. AT THIS TIME...THE NAM12 BY FAR HAS THE MOST WELL DEFINED LAYER OF WARM AIR AMONGST THE MODELS...WHICH WOULD LEAD TO MORE SLEET IN OUR NORTHER AND LESS SNOW. THE GFS AND ECMWF MODELS...ON THE OTHER HAND...ARE BOTH SHOWING A MUCH LESS WELL DEFINED WARM NOSE ALOFT AND THEREFORE MORE SNOW. FOR NOW HAVE DECIDED TO USE A BLEND OF THE TWO SOLUTIONS...GOING WITH A MIX OF SNOW AND SLEET TO START THE EVENT AND LEANING MORE TOWARD THE SNOWFALL AMOUNTS THE WWD FORECAST IS CURRENTLY PREDICTING. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 557 AM EST TUE MAR 3 2015 APPEARS INCREASINGLY LIKELY THAT WE WILL BE DIVING HEADLONG INTO A TRANSITION FROM A HEAVY RAIN INTO A SIGNIFICANT WINTER WEATHER EVENT BY THE BEGINNING OF THE EXTENDED. GFS...ECMWF SOLUTIONS CONTINUE TO SHOW FAIRLY GOOD AGREEMENT WITH THIS SCENARIO. HOWEVER...THE NAM CONTINUES TO TREND FURTHER TO THE NORTHWEST WITH THE MOST SIGNIFICANT FEATURES IN OUR SENSIBLE WEATHER. WITH THE NAM OUTSIDE ITS WINDOW OF BEST PERFORMANCE...GENERAL PREFERRED TO REMAINED CLOSER TO THE OFFICIAL FORECAST AND A CONSENSUS OF THE GFS AND ECMWF. ENOUGH UNCERTAINTY REMAINS IN THE MODEL SOLUTIONS TO WARRANT STAYING WITH THE CURRENT SUITE OF WATCH PRODUCTS THROUGH THE FIRST PORTIONS OF THE EXTENDED. A VERY TIGHT BAROCLINIC ZONE STRETCHING WSW TO ENE ACROSS THE OHIO VALLEY WILL GRADUALLY SHIFT SOUTHEAST INTO TENNESSEE VALLEY THROUGH THURSDAY. WEATHER ALONG THE BAROCLINIC ZONE WILL REMAIN OF ACTIVE AS SEVERAL WAVES OF LOW PRESSURE TRACK THROUGH THE TN VALLEY REGION. COLDER ARCTIC AIR FILTERING INTO OUR AREA ON THE NORTHERN SIDE OF THIS ZONE WILL CHANGE RAIN OVER TO SNOW WEDNESDAY NIGHT. THERMAL PROFILES SUGGEST THAT THERE WILL BE A PERIOD OF MIXED PRECIPITATION DURING THE CHANGOVER...GENERALLY SLEET IN THE NORTH BUT SLEET OR POSSIBLY EVEN SOME FREEZING RAIN IN THE SOUTH. OVERALL MODEL TRENDS SEEM TO BE SLIGHTLY SLOWER WITH THE ONSLAUGHT OF COLD ARCTIC AIR INTO OUR FORECAST AREA LATE WEDNESDAY INTO WEDNESDAY NIGHT. BUT SIGNIFICANT SNOW/SLEET ACCUMULATIONS STILL APPEAR POSSIBLE...WITH THE HIGHEST AMOUNTS LIKELY NEAR THE I-64 CORRIDOR AND LESSER AMOUNTS ACROSS OUR SOUTHEAST. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT BEGINNING LATE THURSDAY NIGHT AND REMAIN OVER THE AREA THROUGH LATE SUNDAY. TEMPS FRIDAY MORNING WILL LIKELY DIP INTO THE SINGLE DIGITS...WITH A FEW SPOTS IN OUR NORTH POSSIBLY DROPPING BELOW 0 DEGREES...WELL BELOW NORMAL FOR MARCH AND NEAR RECORD LOWS. THE COLD SNAP APPEARS TO BE FAIRLY SHORT LIVED AS TEMPERATURES START MODERATING BACK TOWARDS SEASONABLE LEVELS BY THE WEEKEND...THOUGH THEY WILL GENERALLY REMAIN BELOW NORMAL. SOME LIGHT PRECIPITATION WILL BE POSSIBLE EARLY NEXT WEEK AS A WEAK FRONTAL BOUNDARY DROPS SOUTHWARD OUT OF CANADA AND THE GREAT LAKES. BUT WEATHER WITH THIS FEATURE HAS BEEN TRENDING DRIER WITH TIME. FOR NOW MAINTAINED A SLIGHT POP SUNDAY NIGHT INTO MONDAY BUT FEEL THIS MAY BE OVERDONE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 137 PM EST TUE MAR 3 2015 SCT SHOWERS CONTINUE TO MOVE ACROSS NORTH CENTRAL KY...GENERALLY PUSHING JUST NORTH OF EASTERN KY...MISSING MOST OF THE TAF SITES. AS SUCH...TOOK OUT MENTION OF SHRA OR TSRA DIRECTLY IMPACTING THE TAF SITES THROUGH ABOUT 00Z...THOUGH SOME VCSH OR VCTS ARE STILL POSSIBLE. AFTER 0Z...EXPECTING PRECIP TO BEGIN INCREASING IN COVERAGE AND INTENSITY ACROSS KY. WITH INSTABILITY STILL IN PLACE /DUE TO A STRONG PUSH OF COLDER NORTHERLY AIR INTERACTING WITH MOIST SRLY FLOW OFF THE GULF OF MEXICO/...COULD SEE SOME LINGERING POTENTIAL FOR THUNDER THROUGH THE EVENING AS WELL. BY OVERNIGHT...WE WILL LOSE OUR INSTABILITY...BUT RAIN WILL REALLY TAKE HOLD. ALL MODELS ARE SHOWING TAF SITES GOING BELOW AIRPORT MINS THROUGH THE REMAINDER OF THE FORECAST PERIOD...WITH PERIODS OF VIS AND CIGS LIFR AND BELOW. && .JKL WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY EVENING FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104- 106>120. && $$ UPDATE...JMW SHORT TERM...AR LONG TERM...RAY AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
1027 AM EST TUE MAR 3 2015 .UPDATE... ISSUED AT 1026 AM EST TUE MAR 3 2015 LATEST RADAR TRENDS CONTINUE TO MOVE THE HEAVIEST SHOWERS ALONG NORTH CENTRAL KY AND THEN NORTH OF THE CWA. EXPECT THINGS TO EVENTUALLY START SHIFTING SOUTHWARD...BUT THE LATEST HRRR AND NAM12 ARE NOT SHOWING THIS TRANSITION UNTIL THIS EVENING /CLOSER TO 3Z/...A LITTLE LATER THAN ORIGINALLY FORECASTED/ANTICIPATED. AS SUCH...GIVEN THE LATEST RADAR TRENDS AND GOOD INITIATION OF THESE HI RES MODELS...WENT AHEAD AND DROPPED TO ONLY SLIGHT CHANCES ACROSS THE SE CWA THROUGH THE MORNING...INCREASING TO CHANCES THROUGH THE REST OF THE DAY. BY THIS EVENING...HEAVIEST RAIN SHOULD BE MAKING IT INTO MUCH OF THE CWA...SO KEPT WITH A LIKELY/DEFINITE POP FROM THIS POINT ON. ALSO...LOADED IN THE LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE THE NEAR-TERM FORECAST FOR THESE PARAMETERS WAS WELL ON TRACK WITH THE CURRENT CONDITIONS. UPDATE ISSUED AT 850 AM EST TUE MAR 3 2015 QUICK UPDATE TO BRING GRIDS IN LINE WITH HOURLY OBS AND RADAR TRENDS. HAD SOME SPRINKLES THIS MORNING BUT NOTHING SIGNIFICANT WITH RESPECT TO LIGHT FREEZING DZ...RA. TEMPS ARE RISING ABOVE FREEZING NOW. WILL LET CURRENT SPS FOR PATCHY FREEZING DRIZZLE ACROSS PORTIONS OF THE AREA EXPIRE AT 9 AM. ALSO FRESHENED UP THE ZONES. OTHERWISE...NO OTHER CHANGES TO THE FORECAST PACKAGE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 358 AM EST TUE MAR 3 2015 A COMPLICATED WEATHER PATTERN SHAPING UP FOR EASTERN KENTUCKY THROUGH THE MIDDLE OF THE WEEK. THE FIRST FORECAST CONCERN WILL BE THE POTENTIAL FOR FREEZING DRIZZLE OR FREEZING RAIN EARLY THIS MORNING NORTH OF THE MOUNTAIN PARKWAY. THERE IS A SMALL CHANCE THAT SOME LIGHT PRECIPITATION WILL FALL INTO A LAYER OF SUBFREEZING AIR THAT IS CURRENTLY IN PLACE ACROSS THE NORTHERN HALF OF THE FORECAST AREA. THE ISSUE WITH THIS WILL BE WHETHER OR NOT THE PRECIP IS ABLE TO REACH THE GROUND BEFORE TEMPERATURES RISE ABOVE FREEZING. THIS SITUATION WILL CONTINUE TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL HOURS. IF SOME FREEZING PRECIP DOES DEVELOP...AN SPECIAL WEATHER STATEMENT WILL BE ISSUED TO DEAL WITH IT. THE SECOND CONCERN IN THE FIRST 36 HOURS OF THE FORECAST WILL BE HEAVY RAIN AND THE POTENTIAL FOR FLOODING ACROSS THE AREA. AT THIS TIME...THE FORECAST MODELS HAVE MOVED THE AXIS OF HEAVIEST PRECIPITATION TODAY SLIGHTLY NORTH OF WHERE IT WAS IN PREVIOUS RUNS. THE POP AND QPF FORECAST FOR TODAY WAS MODIFIED AS A RESULT TO ACCOUNT FOR THIS CHANGE. IT STILL APPEARS HIGHLY LIKELY THAT EASTERN KENTUCKY WILL EXPERIENCE A PERIOD OF MODERATE TO HEAVY RAIN BEGINNING LATE THIS AFTERNOON AND LASTING THROUGH THE END OF THE DAY ON WEDNESDAY. THERE MAY EVEN BE ENOUGH VERTICAL MOTION AND WIND ENERGY ALOFT TO FIRE OFF A FEW THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. AT THIS TIME...IT STILL APPEARS THAT 2 TO 3 INCHES OF RAIN WILL FALL ACROSS ALL OF EASTERN KENTUCKY. DUE TO RECENTLY MELTED SNOW...THE GROUND IS ALREADY COMPLETELY SATURATED ACROSS THE ENTIRE AREA...SO IT WILL NOT TAKE MUCH RAIN TO BEGIN CAUSING PROBLEMS. BASED ON CURRENT HYDRO FORECASTS...IT APPEARS THAT THE CUMBERLAND RIVER BASIN MAY EXPERIENCE THE MOST SIGNIFICANT FLOODING ISSUES. THERE WILL ALSO BE POINTS ALONG THE KENTUCKY BASIN THAT MAY SEE SIGNIFICANT FLOODING...SUCH AS AT RAVENNA. THE TEMPERATURES TODAY ARE STILL EXPECTED TO RISE ABOVE NORMAL ACROSS THE AREA...WITH HIGHS TOPPING OUT IN THE LOW TO MID 50S FOR THE ENTIRE AREA. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY EVEN APPROACH 60 IN THE STRONG SOUTHERLY FLOW THAT IS ON TAP FOR TODAY. THE END OF THE SHORT TERM PERIOD IS WHERE OUR SECOND AND PERHAPS MORE SERIOUS FORECAST CONCERN LIES. ONCE THE PREVIOUSLY MENTIONED COLD FRONT MOVES THROUGH THE AREA...VERY COLD AIR WILL FILTER INTO THE AREA BEHIND IT...AS WINDS SHIFT TO THE NORTH AND NORTHWEST. WITH A STRONG FEED OF GULF MOISTURE STILL ON TRACK TO OVERRIDE THE SLUGGISH COLD FRONT...SIGNIFICANT AMOUNTS OF PRECIPITATION ARE EXPECTED TO OCCUR. PRECIPITATION WILL GRADUALLY TRANSITION FROM RAIN TO A MIX OF RAIN...SLEET...AND SNOW ALONG AND NORTH OF THE I634 CORRIDOR WEDNESDAY AFTERNOON. THIS MIX OF PRECIPITATION IS FORECAST TO MOVE STEADILY EASTWARD ACROSS THE AREA BEHIND THE DEPARTING FRONT. AS MORE AND MORE COLD AIR MOVES IN...THE PRECIP WILL CHANGE OVER FROM A MESSY WINTRY MIX TO ALL SNOW BY AROUND 0Z THURSDAY. SOME LIGHT SNOW AND SLEET ACCUMULATIONS MAY OCCUR LATE WEDNESDAY IN OUR FAR NORTHWEST. THE CHALLENGE WITH THIS PART OF THE FORECAST WILL BE DETERMINING HOW STRONG THE WARM NOSE ALOFT WILL BE AT THE START OF THE EVENT. AT THIS TIME...THE NAM12 BY FAR HAS THE MOST WELL DEFINED LAYER OF WARM AIR AMONGST THE MODELS...WHICH WOULD LEAD TO MORE SLEET IN OUR NORTHER AND LESS SNOW. THE GFS AND ECMWF MODELS...ON THE OTHER HAND...ARE BOTH SHOWING A MUCH LESS WELL DEFINED WARM NOSE ALOFT AND THEREFORE MORE SNOW. FOR NOW HAVE DECIDED TO USE A BLEND OF THE TWO SOLUTIONS...GOING WITH A MIX OF SNOW AND SLEET TO START THE EVENT AND LEANING MORE TOWARD THE SNOWFALL AMOUNTS THE WWD FORECAST IS CURRENTLY PREDICTING. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 557 AM EST TUE MAR 3 2015 APPEARS INCREASINGLY LIKELY THAT WE WILL BE DIVING HEADLONG INTO A TRANSITION FROM A HEAVY RAIN INTO A SIGNIFICANT WINTER WEATHER EVENT BY THE BEGINNING OF THE EXTENDED. GFS...ECMWF SOLUTIONS CONTINUE TO SHOW FAIRLY GOOD AGREEMENT WITH THIS SCENARIO. HOWEVER...THE NAM CONTINUES TO TREND FURTHER TO THE NORTHWEST WITH THE MOST SIGNIFICANT FEATURES IN OUR SENSIBLE WEATHER. WITH THE NAM OUTSIDE ITS WINDOW OF BEST PERFORMANCE...GENERAL PREFERRED TO REMAINED CLOSER TO THE OFFICIAL FORECAST AND A CONSENSUS OF THE GFS AND ECMWF. ENOUGH UNCERTAINTY REMAINS IN THE MODEL SOLUTIONS TO WARRANT STAYING WITH THE CURRENT SUITE OF WATCH PRODUCTS THROUGH THE FIRST PORTIONS OF THE EXTENDED. A VERY TIGHT BAROCLINIC ZONE STRETCHING WSW TO ENE ACROSS THE OHIO VALLEY WILL GRADUALLY SHIFT SOUTHEAST INTO TENNESSEE VALLEY THROUGH THURSDAY. WEATHER ALONG THE BAROCLINIC ZONE WILL REMAIN OF ACTIVE AS SEVERAL WAVES OF LOW PRESSURE TRACK THROUGH THE TN VALLEY REGION. COLDER ARCTIC AIR FILTERING INTO OUR AREA ON THE NORTHERN SIDE OF THIS ZONE WILL CHANGE RAIN OVER TO SNOW WEDNESDAY NIGHT. THERMAL PROFILES SUGGEST THAT THERE WILL BE A PERIOD OF MIXED PRECIPITATION DURING THE CHANGOVER...GENERALLY SLEET IN THE NORTH BUT SLEET OR POSSIBLY EVEN SOME FREEZING RAIN IN THE SOUTH. OVERALL MODEL TRENDS SEEM TO BE SLIGHTLY SLOWER WITH THE ONSLAUGHT OF COLD ARCTIC AIR INTO OUR FORECAST AREA LATE WEDNESDAY INTO WEDNESDAY NIGHT. BUT SIGNIFICANT SNOW/SLEET ACCUMULATIONS STILL APPEAR POSSIBLE...WITH THE HIGHEST AMOUNTS LIKELY NEAR THE I-64 CORRIDOR AND LESSER AMOUNTS ACROSS OUR SOUTHEAST. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT BEGINNING LATE THURSDAY NIGHT AND REMAIN OVER THE AREA THROUGH LATE SUNDAY. TEMPS FRIDAY MORNING WILL LIKELY DIP INTO THE SINGLE DIGITS...WITH A FEW SPOTS IN OUR NORTH POSSIBLY DROPPING BELOW 0 DEGREES...WELL BELOW NORMAL FOR MARCH AND NEAR RECORD LOWS. THE COLD SNAP APPEARS TO BE FAIRLY SHORT LIVED AS TEMPERATURES START MODERATING BACK TOWARDS SEASONABLE LEVELS BY THE WEEKEND...THOUGH THEY WILL GENERALLY REMAIN BELOW NORMAL. SOME LIGHT PRECIPITATION WILL BE POSSIBLE EARLY NEXT WEEK AS A WEAK FRONTAL BOUNDARY DROPS SOUTHWARD OUT OF CANADA AND THE GREAT LAKES. BUT WEATHER WITH THIS FEATURE HAS BEEN TRENDING DRIER WITH TIME. FOR NOW MAINTAINED A SLIGHT POP SUNDAY NIGHT INTO MONDAY BUT FEEL THIS MAY BE OVERDONE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 358 AM EST TUE MAR 3 2015 VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH AROUND 10Z. CLOUD BASES WILL CONTINUE TO GRADUALLY LOWER THROUGH THE REMAINDER OF THE OVERNIGHT AND PREDAWN HOURS AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. CIGS AT 10 OR 11Z AT JKL...LOZ...AND SME SHOULD RANGE BETWEEN 2.5 AND 3K AS MULTIPLE LAYERS OF LOW LEVEL CLOUDS MOVE IN. CIGS WILL STEADILY LOWER THROUGHOUT THE MORNING...AND WE WILL LIKELY SEE IFR CIGS AT THE TAF SITES BY 14 TO 16Z THIS MORNING. PRECIPITATION IN THE FORM OF DRIZZLE OR LIGHT WILL BEGIN AFFECTING THE TAF SITES BY AROUND 9Z THIS MORNING. THERE IS A SMALL CHANCE FOR SOME FREEZING RAIN OR FREEZING DRIZZLE AT SJS AND SYM BETWEEN 9 AND 13Z AS PRECIP OVERRIDES A LAYER OF NEAR FREEZING AIR NORTH OF THE MOUNTAIN PARKWAY. THE PRECIP SHOULD CHANGE OVER TO ALL RAIN BY 14Z. CONDITIONS WILL WORSEN DURING THE TRANSITION...WITH IFR TO LIFR CONDITIONS THROUGH THE REMAINDER OF THE TAF PERIOD. THERE IS ALSO A CHANCE OF THUNDER THIS AFTERNOON AND EVENING...AS A STRONG COLD MOVING ACROSS THE AREA INTERACTS WITH WARM MOIST AIR OFF THE GULF OF MEXICO. && .JKL WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY EVENING FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104- 106>120. && $$ UPDATE...JMW SHORT TERM...AR LONG TERM...RAY AVIATION...AR
AREA FORECAST DISCUSSION
NWS CARIBOU ME
742 PM EST WED MAR 4 2015 .SYNOPSIS... A SECONDARY ARCTIC COLD FRONT WILL CROSS THE REGION OVERNIGHT. STRONG CANADIAN HIGH PRESSURE WILL BUILD ACROSS THE REGION THURSDAY INTO FRIDAY. ANOTHER COLD FRONT WILL APPROACH LATE FRIDAY NIGHT AND CROSS THE REGION LATE SATURDAY. && .NEAR TERM /THROUGH THURSDAY NIGHT/... 730 PM UPDATE: SECOND ARCTIC FRONT IS SCHEDULED TO MOVE ACROSS THE REGION OVERNIGHT. THIS FRONT WAS ACROSS QUEBEC ATTM AND MOVING S. A LINE OF SNOW SHOWERS/SQUALLS ARE EXPECTED TO MOVE ACROSS NORTHERN MAINE AROUND MIDNIGHT AND THEN SLIDE SE AND BREAK UP. INCREASED THE POPS TO 40% ACROSS FAR NORTHERN MAINE(THE CROWN) AND ADDED UP TO 0.5" OF FLUFFY SNOWFALL W/THIS LINE. TEMPERATURES WERE ADJUSTED TO MATCH THE LATEST OBS. COLDER AIR WILL BE MOVING INTO THE FA OVRNGT IN TWO SUCCESSIVE WVS...THE FIRST MID TO LATE EVE...AND A SECOND ARND DAYBREAK. THE FIRST COULD BE ACCOMPANIED BY SOME CLDNSS AND SN SHWRS WITH A COUPLE OF ST LAWRENCE STREAMERS BEING IMPLIED FOR NRN ME BY THE LATEST HRRR HRLY SIM RADAR FCST GOING INTO THE OVRNGT. ANY ORGANIZATION OF SN SHWR STREAMERS SHOULD WEAKEN LATE TNGT AS LLVL LAPSE RATES DECREASE. JUST S OF THE FA...PRECIP WITH A SECOND WV OF LOW PRES MOVG ENE OFF THE MID ATLANTIC COAST SHOULD REMAIN JUST S OF DOWNEAST COAST LATER TNGT INTO THU MORNING...WITH NRN EDGE OF THE HI CLD SHIELD REACHING NWRD INTO INTERIOR DOWNEAST ME. OTHERWISE...SKIES SHOULD BE MSLY SUNNY...OR BECOMING MSLY SUNNY THU AS COLDER ARCTIC AIR PREVAILS ACROSS THE REGION. UNDER FAIRLY BRISK CONDITIONS...HI TEMPS THU WILL MAKE LMTD RECOVERY FROM LOWS TNGT...AND WILL BE ABOUT 20 DEG F COLDER THAN TDY`S HIGHS. WINDS SHOULD DIMINISH UNDER CLR SKIES THU EVE AS THE SFC RIDGE AXIS XTNDS WSW TO ENE ACROSS THE FA...WITH DECENT RADIATIONAL FOR MSLY BROAD VLY AREAS LATE THU NGT WHILE HIER TRRN HOLDS ON ON TO A LGT BREEZE. LOWS THU NGT WILL BE QUITE COLD...POTENTIALLY INTO THE -20S DEG F OVR THE COLDEST NW VLY AREAS WITH SINGLE DIGIT AND TEENS BELOW ZERO ELSEWHERE. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... HIGH PRESSURE WILL BRING DRY WEATHER CONDITIONS TO THE REGION FRIDAY. HIGHS WILL RANGE FROM THE TEENS NORTH THE LOWER 20S DOWNEAST. A COLD FRONT APPROACHES FRIDAY NIGHT WITH INCREASING CLOUDS LATE. LOWS FRIDAY NIGHT WILL BE IN THE SINGLE DIGITS ACROSS THE AREA. A COLD FRONT WILL CROSS THE REGION SATURDAY WITH THE CHANCE FOR SOME NORTHERN SNOW SHOWERS. HIGHS ON SATURDAY WILL BE CLOSE TO NORMAL FOR THIS TIME OF YEAR. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE UPPER LEVEL PATTERN WILL BE FAIRLY ZONAL THROUGH MOST OF THE LONG TERM PORTION OF THE FORECAST. THIS WILL BRING A SERIES OF SHORT WAVES ACROSS THE REGION DURING THIS PERIOD BUT NO MAJOR STORMS ARE EXPECTED. TEMPERATURES WILL ACTUALLY BE CLOSE TO SEASONAL LEVELS AT THE BEGINNING OF THE PERIOD AND THEN RISE TO A BIT ABOVE NORMAL LEVELS BY THE MIDDLE OF NEXT WEEK. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... NEAR TERM: MSLY VFR THRU THU NGT...WITH BRIEF INTERVALS OF MVFR CLGS AND VSBYS POSSIBLE WITH ISOLD SN SHWRS OVR NRN MOST TAF SITES LATE THIS EVE INTO THE OVRNGT TNGT. SHORT TERM: VFR THROUGH MUCH OF THIS PERIOD ALTHOUGH MVFR IS POSSIBLE AT TIMES IN SCT SNOW SHOWER MAINLY ACROSS THE NORTH. && .MARINE... NEAR TERM: SCA WIND AND SEA CONDITIONS WILL PREVAIL AT LEAST INTO THU AFTN...SPCLY OVR OUTER MZS050-051. OTHERWISE...WITH COLDER AIR MOVING BACK OVR THE WATERS...A PD OF MDT FZG SPY IS POSSIBLE THU NGT. KEPT CLOSE TO WW3 WV HTS...WITH WV HTS THIS EVE RUNNING ABOUT A FOOT OR TWO ABV GUIDANCE...THEN TO GUIDANCE BY MID THU MORN. SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SCA LEVELS FRIDAY. WIND GUSTS COULD APPROACH SCA LEVELS FRIDAY NIGHT AND SATURDAY. LIGHT FREEZING SPRAY IS POSSIBLE FRIDAY NIGHT AND SATURDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THURSDAY FOR ANZ050>052. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THURSDAY FOR ANZ050>052. && $$ NEAR TERM...HEWITT/VJN SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT/VJN/DUDA MARINE...HEWITT/VJN/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
931 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE WILL SLIDE SOUTH OF THE AREA TODAY. A FAST MOVING TROUGH OF LOW PRESSURE WILL CROSS THE REGION TONIGHT. HIGH PRESSURE WILL BUILD TOWARD THE EAST COAST WEDNESDAY THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... 930 AM UPDATE: ADJUSTED THE SKY CONDITIONS TO ALLOW FOR MORE SUNSHINE AS THE NAM12 AND RAP KEEP THE THICKEST CLOUD SHIELD FURTHER S THROUGH THE AFTERNOON AS RIDGE AXIS IS OVERHEAD. ALSO NEEDED TO PUSH BACK TIMING OF THE ARRIVAL OF SNOW AND LOWERED THE POPS THIS AFTERNOON. HRLY TEMPS WERE ADJUSTED TO ACCOUNT FOR THE LATEST CONDITIONS. STRONG HIGH PRESSURE WILL MOVE ACROSS THE REGION TODAY THEN MOVE TO THE EAST THIS EVENING. OVER-RUNNING SNOW WILL SPREAD ACROSS THE REGION THIS EVENING AS LOW PRESSURE APPROACHES FROM THE WEST. SNOW COULD MIX WITH OR CHANGE TO RAIN IN COASTAL AREA LATE TONIGHT BUT EXPECT MOST OF THE PRECIPITATION WILL BE IN THE FORM OF SNOW. WILL USE PRECIPITATION TYPE FROM THICKNESS TOOL RUN ON 50/50 BLEND OF THE NAM AND GFS. WILL ALSO USE SNOW ACCUMULATION FROM THICKNESS FOR SNOW AMOUNTS. FOR QPF... POPS AND SKY CONDITIONS WILL BLEND THE NAM... GFS AND ECMWF. HAVE USED THE GMOS FOR WINDS. HAVE MANUALLY ADJUSTED THE TEMPERATURE AND DEW POINTS. WILL ISSUE ADVISORY FOR SNOW. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... LOW PRESSURE NORTH OF THE AREA COMBINED WITH HIGH PRESSURE BEGINNING TO BUILD IN FROM THE WEST WILL BRING A WARM AND WINDY DAY ON WEDNESDAY. TEMPERATURES WILL GET ABOVE FREEZING ACROSS THE AREA RANGING FROM THE 30S ACROSS THE NORTH TO THE 40S DOWNEAST. WEST WINDS WILL BE VERY GUSTY, ESPECIALLY IN THE AFTERNOON, AS COOLER AIR BEGINS WORKING IN FORM THE WEST AND STRONG WINDS ALOFT BEGIN TO MIX DOWN. WEDNESDAY NIGHT WILL BE BREEZY AND COOLER. HIGH PRESSURE WILL THEN BRING A SUNNY TO PARTLY CLOUDY AND COLD DAY ON THURSDAY WITH TEMPS ABOUT 20 DEGREES COLDER THAN THEY WILL BE ON WEDNESDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... DRY WEATHER WILL CONTINUE FRIDAY AS HIGH PRESSURE SLIDES TOWARD THE EAST COAST. A WEAK TROUGH OF LOW PRESSURE FRIDAY NIGHT THROUGH SATURDAY WILL BRING A CHANCE FOR SOME SNOW SHOWERS. DRY WEATHER WILL RETURN FOR SUNDAY. A SMALL CLIPPER LOW MAY THEN BRING ANOTHER CHANCE FOR SNOW SHOWERS ON MONDAY BEFORE HIGH PRESSURE BRINGS A RETURN OF DRY WEATHER ON TUESDAY. IN GENERAL, NO MAJOR STORMS ARE IN SIGHT WELL INTO NEXT WEEK AS A BROAD TROUGH REMAINS OVER THE EAST AND WEAK, FAST MOVING LOWS FOLLOWED BY LARGE HIGHS DOMINATE THE PATTERN. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... NEAR TERM: EXPECT VFR CONDITIONS TODAY THEN IFR CONDITIONS EARLY THIS EVENING AS SNOW SPREADS ACROSS THE AREA. SHORT TERM: CONDITIONS WILL BECOME VFR WEDNESDAY. VERY GUSTY WINDS MAY RESULT IN TURBULANCE, ESPECIALLY IN THE AFTERNOON WEDNESDAY. MAINLY VFR CONDITIONS SHOULD PERSIST THROUGH FRIDAY. CONDITIONS MAY LOWER TO MVFR ACROSS THE NORTH FRIDAY NIGHT THEN MVFR OR IFR ON SATURDAY IN LOWER CLOUDS. && .MARINE... UPDATE 0545 EST: HAVE LOWERED GALE TO SCA. NEAR TERM: HAVE USED THE NAM12 FOR SUSTAINED WINDS. FOR WAVES: PRIMARY WAVE SYSTEM EARLY TODAY WILL BE OFF-SHORE WIND WAVE WITH HEIGHTS A FUNCTION OF FETCH DISTANCE FROM SHORE. WIND WAVE WILL SUBSIDE WITH WINDS LATER TODAY. A NEW SOUTHERLY FETCH WILL DEVELOP TONIGHT ACROSS THE GULF OF MAINE WITH WIND WAVE BUILDING TO 6 TO 10 FEET/8 SECONDS BY MORNING. SHORT TERM: A STRONG SCA OR A GALE WILL LIKELY BE NEEDED WEDNESDAY INTO WEDNESDAY NIGHT FOR GUSTY WEST WINDS. AN SCA MAY BE NEEDED THURSDAY. WINDS MAY DIMINISH FRIDAY AS HIGH PRESSURE BUILDS OVER. AN SCA MAY BE NEEDED ON SATURDAY. WINDS SHOULD THEN BE LIGHTER SUNDAY WITH ANOTHER HIGH BUILDING OVER THE WATERS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR MEZ002>006-010-011-015>017-029>032. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ050>052. FREEZING SPRAY ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ050>052. && $$ NEAR TERM...HEWITT/MIGNONE SHORT TERM...BLOOMER LONG TERM...BLOOMER AVIATION...HEWITT/MIGNONE/BLOOMER MARINE...HEWITT/MIGNONE/BLOOMER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1240 AM EST TUE MAR 3 2015 .SYNOPSIS... AN ARCTIC COLD FRONT WILL CROSS THE AREA THIS EVENING. HIGH PRESSURE WILL RIDGE ACROSS THE AREA ON TUESDAY FROM THE WEST. ANOTHER LOW WILL CROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY. && .NEAR TERM /THROUGH TODAY/... UPDATE 0010 EST: HAVE ADJUSTED POP GRIDS TO EXTEND SNOW SHOWERS A FEW MORE HOURS. ALSO UPDATED WINDS... TEMPERATURE AND DEW POINT BASED ON LATEST OBSERVATIONS. PREVIOUS DISCUSSION... SNOW SHOWERS/SQUALLS THIS EVENING AND THEN MUCH COLDER. WIND CHILLS WILL BE THE MAIN CONCERN OVERNIGHT INTO TUESDAY MORNING. 20Z SURFACE ANALYSIS SHOWED THE ARCTIC FRONT MAKING ITS WAY SE ACROSS THE REGION. THE FIRST BATCH OF SNOW SHOWERS/SQUALLS OUT AHEAD OF THE BOUNDARY THIS AFTERNOON PER THE RADAR. ANOTHER ROUND SETTING UP AND WILL DIVE SE W/THE UPPER LEVEL SUPPORT EARLY THIS EVENING. THE LATEST RUN OF THE HRRR 3KM AND RAP MODEL DOING WELL W/THE PLACEMENT OF THE SNOW MATCHING UP W/THE RADAR TRENDS. LAPSE RATES ARE STEEPENING ATTM ESPECIALLY FROM 850-700MBS(7.0 C/KM). THIS COMBINED W/DECENT SHEAR AT 0-3KM OF 35 KTS AND FORECAST CAPE 80+ JOULES WILL BE ENOUGH TO GET SOME MORE SQUALLS GOING. 12Z UPPER AIR ANALYSIS SUPPORTED THE MODEL SOUNDINGS W/DEEP MOISTURE THROUGH 700MBS. THE HEAVIEST ACTIVITY WILL RESIDE FROM THE ST. JOHN VALLEY DOWN THROUGH CARIBOU-PRESQUE ISLE DOWN INTO HOULTON. ANOTHER AREA OF HEAVY SNOW SHOWERS/SQUALLS IS FORECAST TO DROP ACROSS PORTIONS OF CENTRAL MAINE INCLUDING THE MILLINOCKET-PATTEN AREA ALONG ROUTE 11 AND PORTIONS OF I-95. BRIEF HEAVY SNOW BURSTS W/WIND GUSTS TO 35 MPH WILL LEAD TO BRIEF WHITEOUTS AND VSBY 1/4 OF A MILE OR LESS. CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS EVENING AS SKIES BEGIN TO CLEAR AND THE FRONT PUSHES TO THE COAST. WINDS WILL REMAIN UP AT 15 TO 25 MPH SUSTAINED THROUGH THE OVERNIGHT PERIOD W/GUSTS AT LEAST 30 MPH. THESE WINDS COMBINED W/THE ARCTIC AIRMASS MOVING IN WILL LEAD TO SOME DANGEROUS WIND CHILLS ACROSS THE NORTHERN 1/2 OF THE CWA. WIND CHILL ADVISORIES REMAIN UP FOR NORTHERN AREAS THROUGH TUESDAY MORNING. ATTM, IT LOOKS LIKE THE CENTRAL HIGHLANDS AND DOWNEAST WILL SEE WIND CHILLS STAY ABOVE ADVISORY CRITERIA OF -20F. FOR TUESDAY, HIGH PRES IS FORECAST TO RIDGE ACROSS THE REGION W/DAYTIME TEMPERATURES BELOW NORMAL FOR EARLY MARCH. CLOUDS WILL BE ON THE INCREASE LATER IN THE AFTERNOON IN ADVANCE OF THE NEXT SYSTEM TO AFFECT OUR REGION. THIS IS EXPLAINED MORE IN THE SHORT TERM SECTION BELOW. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... LOOKING FOR ANOTHER SNOW EVENT TUESDAY NIGHT JUST AHEAD OF A WARM FRONT MOVING FROM WEST TO EAST THROUGH THE AREA SOUTH OF THE PARENT LOW PASSING WELL TO OUR NORTH. TEMPERATURES WILL BE RISING THROUGH THE NIGHT TUESDAY NIGHT, BUT THINK THAT FOR THE VAST MAJORITY OF AREAS, THIS WILL BE AN ALL SNOW EVENT, PERHAPS ENDING AS JUST A BIT OF LIGHT RAIN NEAR THE COAST. LOOKING FOR ABOUT 3 TO 5 INCHES OF SNOW. AFTER THE WARM FRONT PASSES LATE TUESDAY NIGHT, WE ARE LOOKING FOR A WARM DAY WEDNESDAY WITH HIGHS ABOVE FREEZING FOR PRETTY MUCH EVERYWHERE, AND EVEN IN THE LOW 40S DOWNEAST. THE WARMTH IS SHORT LIVED, HOWEVER, AS THE COLD FRONT MOVES THROUGH LATE WEDNESDAY. THURSDAY WILL BE MUCH COOLER WITH TEMPERATURES NEAR STEADY IN THE TEENS TO LOW 20S. THERE MAY BE A FEW SNOW SHOWERS WITH AND BEHIND THE FRONT LATE WEDNESDAY INTO THURSDAY, BUT NOTHING MAJOR. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... LOOK FOR BELOW AVERAGE TEMPERATURES TO PERSIST FRIDAY THROUGH EARLY NEXT WEEK. WE DO NOT FORESEE ANY MAJOR STORMS, BUT THERE COULD BE A FEW WEAK ONES BEYOND FRIDAY AFTER WEAK HIGH PRESSURE OVER THE AREA WEAKENS. TOO MUCH MODEL DISAGREEMENT TO TIME THE WEAK SYSTEMS THIS FAR OUT. && .AVIATION /05Z TUESDAY THROUGH SATURDAY/... NEAR TERM: VFR FOR THE MOST PART FOR ALL TERMINALS INTO TUE. BRIEF IFR IN ISOLATED SNOW SHOWERS AND AREAS OF BLOWING SNOW TONIGHT AS A NW SFC WIND GUSTS TO 35 KNOTS. THE WIND WILL DIMINISH TUE MORNING. SHORT TERM: IFR OR WORSE AREAWIDE TUESDAY NIGHT WITH SNOW. PRECIPITATION TAPERING OFF WEDNESDAY THROUGH THURSDAY WITH GENERALLY VFR, THOUGH MVFR COULD LINGER IN THE NORTH ESPECIALLY WEDNESDAY. && .MARINE... NEAR TERM: GALES ARE OCCURRING NOW AS THE COLD AIR POURS OUT OVER THE WATERS. WINDS ARE EXPECTED TO DROP BACK TO SCA LEVELS BY EARLY TUESDAY MORNING. THE SCA LOOKS TO BE SHORT LIVED AS HIGH PRES RIDGES IN FROM THE SOUTH. SEAS OF 5 TO 8 FT OVERNIGHT WILL SUBSIDE TUE. FREEZING SPRAY WILL BE DEVELOPING OVERNIGHT INTO EARLY TUE MORNING. SHORT TERM: EXPECT PROLONGED SMALL CRAFT CONDITIONS TUESDAY NIGHT THROUGH THURSDAY NIGHT. WINDS WILL SHIFT FROM SOUTH TO NORTHWEST AS A SYSTEM MOVES THROUGH. SEAS WILL PEAK AROUND 9 FEET ON WEDNESDAY. && .CLIMATE... THE METEOROLOGICAL WINTER WHICH IS THE 3 MONTH PERIOD OF DECEMBER THROUGH FEBRUARY HAD AN AVERAGE TEMPERATURE OF 16.8 DEGREES AT BANGOR. IT WAS THE COLDEST SINCE THE WINTER OF 2002-03. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WIND CHILL ADVISORY UNTIL 7 AM EST THIS MORNING FOR MEZ001>004. MARINE...FREEZING SPRAY ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ050>052. GALE WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR ANZ050>052. && $$ NEAR TERM...CB/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1221 PM EST TUE MAR 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM EST TUE MAR 3 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS NAMERICA WITH ARCTIC AND POLAR/SUBTROPICAL BRANCH RDG OVER THE GREAT LKS EARLY THIS MRNG. LOCAL 00Z ROABS SHOW A VERY DRY AIRMASS WITH PWATS UNDER 0.10 INCH AT INL/GRB/APX...ON AVERAGE 33 PCT OF NORMAL...AND H7 DEWPT DEPRESSIONS UP TO 40-45C. THERE ARE TWO SHRTWVS THAT WL HAVE A SGNFT IMPACT ON UPR MI WX...ONE IN EACH STREAM. THE POLAR/SUBTROPICAL BRANCH SHRTWV IS LIFTING NEWD INTO THE WRN PLAINS EARLY THIS MRNG AND SUPPORTING A WELL DEFINED BAROCLINIC LEAF CLD...WITH SOME VERY COLD CLD TOPS OVER NEBRASKA AND IOWA JUST TO THE N OF H85 WARM FNT ATTENDANT TO DVLPG SFC LO PRES IN FAR NW KANSAS AND WHERE THERE IS ENHANCED UPR DVGC IN EXIT REGION OF SUPPORTING 140KT H3 JET MAX. IN THE ARCTIC BRANCH...THERE IS A STRONG SHRTWV DIGGING SEWD INTO MANITOBA...WITH 12HR H5 HGT FALLS APRCHG 150M IN THE VIGOROUS DPVA AHEAD OF THIS FEATURE. SFC COLD FNT HANGING S OF THE ACCOMPANYING SFC LO MOVING INTO FAR NW ONTARIO EXTENDS S INTO THE NRN PLAINS AND IS APRCHG NW MN. CLOSER TO HOME... A BAND OF COLDER CLD TOPS IS NOTED NEAR THE WI BORDER ALONG AXIS OF FGEN SHOWN BEST BTWN ABOUT H7-5. HOWEVER...DRYNESS OF ANTECEDENT AIRMASS HAS SO FAR LIMITED THE COVERAGE/INTENSITY OF ACCOMPANYING LIGHT SN. MAIN FCST CONCERNS THIS FCST PERIOD WL BE ON POPS/SN TOTALS ASSOCIATED WITH THE TWO SHRTWVS NOTED ABOVE. SINCE THESE DISTURBANCES WL REMAIN OUT OF PHASE...OVERALL SN TOTALS EXPECTED TODAY OVER UPR MI WL NOT BE EXCESSIVE BEFORE MUCH COLDER AIR FOLLOWING THE ARCTIC BRANCH FROPA SURGES INTO THE AREA TNGT AND BRINGS A RETURN OF SOME LES. TODAY...SRN BRANCH DISTURBANCE IS FCST TO ACCELERATE TO THE NE AND ACROSS THE UPPER MIDWEST IN FAST WSW FLOW BTWN THE TWO BRANCHES AS THE NRN BRANCH SHRTWV PUSHES INTO NW ONTARIO...WITH COLD FNT ATTENDANT TO ACCOMPANY SFC LO REACHING THE WRN CWA LATE IN THE DAY. ARRIVAL OF SOME VIGOROUS DEEP LYR QVECTOR CNVGC/UPR DVGC IN LEFT EXIT OF SUPPORTING H3 JET MAX AS WELL AS DEEP ISENTROPIC ASCENT IN THE SSW FLOW ALF IN ADVANCE OF THESE DISTURBANCES WL CAUSE BAND OF PATCHY SN NEAR THE WI BORDER EARLY RELATED TO MID LVL FGEN TO EXPAND IN COVERAGE DURING THE MRNG HRS. SINCE THE SHARPEST ISENTROPIC ASCENT AS WELL AS FGEN THAT IS MAXIMIZED IN THE H7-6 LYR IS FCST TO IMPACT MAINLY THE SE HALF OF THE CWA...WHERE SOME LK ENHANCEMENT OFF LK MI LIMITED SOMEHWAT BY ICE COVERAGE IS PSBL IN THE LLVL SLY FLOW AHEAD OF THE SFC LO ASSOCIATED WITH THE SRN BRANCH DISTURBANCE... EXPECT THE GREATER SN TOTALS IN THIS AREA. WITH SPECIFIC HUMIDITY IN THE H7-75 LYR UP TO 3G/KG...3-6 INCHES OF SN SEEMS A GOOD BET FOR 6- 9 HR PERIOD OF STEADY PCPN EXPECTED BEFORE ARRIVAL OF DNVA/VIGOROUS QVECTOR DVGC DURING THE MID TO LATE AFTN IN THE WAKE OF THIS DISTURANCE WL BRING AN END TO THE STEADIER SN W-E AND OVER THE FAR E BY 00Z WED. ALTHOUGH THE SHARPER ISENTROPIC ASCENT/FGEN/MSTR TRANSPORT WL TEND TO MISS THE WRN CWA...EXPECTED HIER SN/WATER RATIOS IN THAT AREA DUE TO A DEEPER FCST DGZ MAY HELP RAISE SN TOTALS AT LEAST TO THE 3 INCH THRESHOLD IN THAT AREA. WL MAINTAIN GOING ADVY FOR THE ENTIRE CWA AS IS EVEN THOUGH THE HEADLINE MAY BE DROPPED A FEW HRS EARLY OVER THE W. TNGT...UPR MI WL BE DOMINATED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE IN THE WAKE OF THE DEPARTING DISTURBANCES. BUT ARRIVAL OF COLDER AIR IN THE WAKE OF ARCTIC BRANCH COLD FROPA THAT IS FCST TO DROP H85 TEMPS TO AS LO AS -26C OVER THE W BY 12Z WED WL RESULT IN LES...MAINLY IN AERAS THAT ARE DOWNSTREAM OF HOLES IN THE ICE COVER OBSVED JUST E OF THE MN ARROWHEAD...THE BAYFIELD PENINSULA AND THE KEWEENAW PENINSULA IN THE FCST WNW H925 FLOW. BUT STILL RATHER EXTENSIVE ICE COVER... AS WELL AS DISAPPEARING DGZ OVER THE W RELATED TO THE CHILL OF THE INCOMING AIRMASS...WL HOLD DOWN SN TOTALS. THE BEST CHANCE FOR MORE NMRS SN SHOWERS APPEARS TO BE E OF MUNISING IN ALGER COUNTY THAT WL BE DOWNWIND OF THE AREA OF OPEN WATER E OF THE KEWEENAW AND WHERE THE ONSHORE 290 FLOW WL BE MORE PARALLEL TO THAT AREA OF OPEN WATER. GUSTY WINDS RELATED TO FCST H925 WINDS UP TO 35-40KTS/STRONG CAA AND DESTABILIZATION WL CAUSE SOME GUSTY WINDS...ESPECIALLY NEAR THE LK SUP SHORE. GUSTS IN THE MORE EXPOSED LOCATIONS E OF MUNISING MAY APRCH ADVY CRITERIA. OVER THE SCENTRAL...EXPECT SOME CLEARING...WITH MIN TEMPS FALLING BLO ZERO OVER THE INTERIOR W HALF...ESPECIALLY NEAR THE WI BORDER WHERE LK MODERATION WL BE MINIMAL OR ABSENT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 356 AM EST TUE MAR 3 2015 A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU. FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1220 PM EST TUE MAR 3 2015 ARRIVAL OF STRONGER DYNAMIC FORCING WL RESULT IN STEADY SN AND CAUSE PREDOMINANT IFR VSBYS INTO MID AFTN. AS THIS FORCING EXITS W-E THIS AFTN... CONDITIONS WL IMPROVE TO MVFR. A STRONG COLD FNT WL THEN PASS LATE THIS AFTN OVER THE W AND DURING THE EVNG AT SAW. GUSTY WNW WINDS WL DVLP IN ITS WAKE. EXPECT THE STRONGEST WINDS AT THE MORE EXPOSED IWD AND ESPECIALLY THE CMX LOCATIONS. DESPITE EXTENSIVE ICE COVER ON LK SUP...MVFR CONDITIONS ARE LIKELY TO PREDOMINANT AT THESE LOCATIONS WITH AN UPSLOPE WIND COMPONENT. DOWNSLOPE FLOW INTO SAW WL CAUSE VFR CONDITIONS THERE TNGT FOLLOWING THE COLD FROPA. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 410 AM EST TUE MAR 3 2015 S WINDS UP TO 25 KTS TODAY IN ADVANCE OF AN APPROACHING COLD FRONT WILL SHIFT TO THE WNW FOLLOWING THE PASSAGE OF THIS FRONT LATE TODAY/TONIGHT. TIGHTENING PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HI PRES MOVING INTO THE NORTHERN PLAINS WILL BRING A PERIOD OF WNW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. UPGRADED GALE WATCH TO A WARNING FOR THESE AREAS. AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE FORECAST PERIOD. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK THAT WILL OPEN SOME HOLES IN THE ICE...THE SIGNIFICANT ICE COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR MIZ001>007-009>014-084-085. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR LSZ266. GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR LSZ265. GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR LSZ264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...07 MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
643 AM EST TUE MAR 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM EST TUE MAR 3 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS NAMERICA WITH ARCTIC AND POLAR/SUBTROPICAL BRANCH RDG OVER THE GREAT LKS EARLY THIS MRNG. LOCAL 00Z ROABS SHOW A VERY DRY AIRMASS WITH PWATS UNDER 0.10 INCH AT INL/GRB/APX...ON AVERAGE 33 PCT OF NORMAL...AND H7 DEWPT DEPRESSIONS UP TO 40-45C. THERE ARE TWO SHRTWVS THAT WL HAVE A SGNFT IMPACT ON UPR MI WX...ONE IN EACH STREAM. THE POLAR/SUBTROPICAL BRANCH SHRTWV IS LIFTING NEWD INTO THE WRN PLAINS EARLY THIS MRNG AND SUPPORTING A WELL DEFINED BAROCLINIC LEAF CLD...WITH SOME VERY COLD CLD TOPS OVER NEBRASKA AND IOWA JUST TO THE N OF H85 WARM FNT ATTENDANT TO DVLPG SFC LO PRES IN FAR NW KANSAS AND WHERE THERE IS ENHANCED UPR DVGC IN EXIT REGION OF SUPPORTING 140KT H3 JET MAX. IN THE ARCTIC BRANCH...THERE IS A STRONG SHRTWV DIGGING SEWD INTO MANITOBA...WITH 12HR H5 HGT FALLS APRCHG 150M IN THE VIGOROUS DPVA AHEAD OF THIS FEATURE. SFC COLD FNT HANGING S OF THE ACCOMPANYING SFC LO MOVING INTO FAR NW ONTARIO EXTENDS S INTO THE NRN PLAINS AND IS APRCHG NW MN. CLOSER TO HOME... A BAND OF COLDER CLD TOPS IS NOTED NEAR THE WI BORDER ALONG AXIS OF FGEN SHOWN BEST BTWN ABOUT H7-5. HOWEVER...DRYNESS OF ANTECEDENT AIRMASS HAS SO FAR LIMITED THE COVERAGE/INTENSITY OF ACCOMPANYING LIGHT SN. MAIN FCST CONCERNS THIS FCST PERIOD WL BE ON POPS/SN TOTALS ASSOCIATED WITH THE TWO SHRTWVS NOTED ABOVE. SINCE THESE DISTURBANCES WL REMAIN OUT OF PHASE...OVERALL SN TOTALS EXPECTED TODAY OVER UPR MI WL NOT BE EXCESSIVE BEFORE MUCH COLDER AIR FOLLOWING THE ARCTIC BRANCH FROPA SURGES INTO THE AREA TNGT AND BRINGS A RETURN OF SOME LES. TODAY...SRN BRANCH DISTURBANCE IS FCST TO ACCELERATE TO THE NE AND ACROSS THE UPPER MIDWEST IN FAST WSW FLOW BTWN THE TWO BRANCHES AS THE NRN BRANCH SHRTWV PUSHES INTO NW ONTARIO...WITH COLD FNT ATTENDANT TO ACCOMPANY SFC LO REACHING THE WRN CWA LATE IN THE DAY. ARRIVAL OF SOME VIGOROUS DEEP LYR QVECTOR CNVGC/UPR DVGC IN LEFT EXIT OF SUPPORTING H3 JET MAX AS WELL AS DEEP ISENTROPIC ASCENT IN THE SSW FLOW ALF IN ADVANCE OF THESE DISTURBANCES WL CAUSE BAND OF PATCHY SN NEAR THE WI BORDER EARLY RELATED TO MID LVL FGEN TO EXPAND IN COVERAGE DURING THE MRNG HRS. SINCE THE SHARPEST ISENTROPIC ASCENT AS WELL AS FGEN THAT IS MAXIMIZED IN THE H7-6 LYR IS FCST TO IMPACT MAINLY THE SE HALF OF THE CWA...WHERE SOME LK ENHANCEMENT OFF LK MI LIMITED SOMEHWAT BY ICE COVERAGE IS PSBL IN THE LLVL SLY FLOW AHEAD OF THE SFC LO ASSOCIATED WITH THE SRN BRANCH DISTURBANCE... EXPECT THE GREATER SN TOTALS IN THIS AREA. WITH SPECIFIC HUMIDITY IN THE H7-75 LYR UP TO 3G/KG...3-6 INCHES OF SN SEEMS A GOOD BET FOR 6- 9 HR PERIOD OF STEADY PCPN EXPECTED BEFORE ARRIVAL OF DNVA/VIGOROUS QVECTOR DVGC DURING THE MID TO LATE AFTN IN THE WAKE OF THIS DISTURANCE WL BRING AN END TO THE STEADIER SN W-E AND OVER THE FAR E BY 00Z WED. ALTHOUGH THE SHARPER ISENTROPIC ASCENT/FGEN/MSTR TRANSPORT WL TEND TO MISS THE WRN CWA...EXPECTED HIER SN/WATER RATIOS IN THAT AREA DUE TO A DEEPER FCST DGZ MAY HELP RAISE SN TOTALS AT LEAST TO THE 3 INCH THRESHOLD IN THAT AREA. WL MAINTAIN GOING ADVY FOR THE ENTIRE CWA AS IS EVEN THOUGH THE HEADLINE MAY BE DROPPED A FEW HRS EARLY OVER THE W. TNGT...UPR MI WL BE DOMINATED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE IN THE WAKE OF THE DEPARTING DISTURBANCES. BUT ARRIVAL OF COLDER AIR IN THE WAKE OF ARCTIC BRANCH COLD FROPA THAT IS FCST TO DROP H85 TEMPS TO AS LO AS -26C OVER THE W BY 12Z WED WL RESULT IN LES...MAINLY IN AERAS THAT ARE DOWNSTREAM OF HOLES IN THE ICE COVER OBSVED JUST E OF THE MN ARROWHEAD...THE BAYFIELD PENINSULA AND THE KEWEENAW PENINSULA IN THE FCST WNW H925 FLOW. BUT STILL RATHER EXTENSIVE ICE COVER... AS WELL AS DISAPPEARING DGZ OVER THE W RELATED TO THE CHILL OF THE INCOMING AIRMASS...WL HOLD DOWN SN TOTALS. THE BEST CHANCE FOR MORE NMRS SN SHOWERS APPEARS TO BE E OF MUNISING IN ALGER COUNTY THAT WL BE DOWNWIND OF THE AREA OF OPEN WATER E OF THE KEWEENAW AND WHERE THE ONSHORE 290 FLOW WL BE MORE PARALLEL TO THAT AREA OF OPEN WATER. GUSTY WINDS RELATED TO FCST H925 WINDS UP TO 35-40KTS/STRONG CAA AND DESTABILIZATION WL CAUSE SOME GUSTY WINDS...ESPECIALLY NEAR THE LK SUP SHORE. GUSTS IN THE MORE EXPOSED LOCATIONS E OF MUNISING MAY APRCH ADVY CRITERIA. OVER THE SCENTRAL...EXPECT SOME CLEARING...WITH MIN TEMPS FALLING BLO ZERO OVER THE INTERIOR W HALF...ESPECIALLY NEAR THE WI BORDER WHERE LK MODERATION WL BE MINIMAL OR ABSENT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 356 AM EST TUE MAR 3 2015 A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU. FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 643 AM EST TUE MAR 3 2015 A BAND OF SOME -SN FALLING INTO LLVL DRY AIR MAY RESULT IN MVFR CONDITIONS AT TIMES INTO MID MRNG...BUT THE ARRIVAL OF STRONGER DYNAMIC FORCING IN ADVANCE OF A LO PRES MOVING NE FM THE CENTRAL PLAINS WL RESULT IN STEADY SN BY MID MRNG AND CAUSE PREDOMINANT IFR VSBYS INTO MID AFTN. AS THIS FORCING EXITS W-E THIS AFTN... CONDITIONS WL IMPROVE TO MVFR. A STRONG COLD FNT WL THEN PASS LATE THIS AFTN OVER THE W AND DURING THE EVNG AT SAW. GUSTY WNW WINDS WL DVLP IN ITS WAKE. EXPECT THE STRONGEST WINDS AT THE MORE EXPOSED IWD AND ESPECIALLY THE CMX LOCATIONS. DESPITE EXTENSIVE ICE COVER ON LK SUP...MVFR CONDITIONS ARE LIKELY TO PREDOMINANT AT THESE LOCATIONS WITH AN UPSLOPE WIND COMPONENT. DOWNSLOPE FLOW INTO SAW WL CAUSE VFR CONDITIONS THERE TNGT FOLLOWING THE COLD FROPA. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 410 AM EST TUE MAR 3 2015 S WINDS UP TO 25 KTS TODAY IN ADVANCE OF AN APPROACHING COLD FRONT WILL SHIFT TO THE WNW FOLLOWING THE PASSAGE OF THIS FRONT LATE TODAY/TONIGHT. TIGHTENING PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HI PRES MOVING INTO THE NORTHERN PLAINS WILL BRING A PERIOD OF WNW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. UPGRADED GALE WATCH TO A WARNING FOR THESE AREAS. AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE FORECAST PERIOD. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK THAT WILL OPEN SOME HOLES IN THE ICE...THE SIGNIFICANT ICE COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR MIZ001>007-009>014-084-085. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR LSZ266. GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR LSZ265. GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR LSZ264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION...CORRECTED
NWS MARQUETTE MI
413 AM EST TUE MAR 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM EST TUE MAR 3 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS NAMERICA WITH ARCTIC AND POLAR/SUBTROPICAL BRANCH RDG OVER THE GREAT LKS EARLY THIS MRNG. LOCAL 00Z ROABS SHOW A VERY DRY AIRMASS WITH PWATS UNDER 0.10 INCH AT INL/GRB/APX...ON AVERAGE 33 PCT OF NORMAL...AND H7 DEWPT DEPRESSIONS UP TO 40-45C. THERE ARE TWO SHRTWVS THAT WL HAVE A SGNFT IMPACT ON UPR MI WX...ONE IN EACH STREAM. THE POLAR/SUBTROPICAL BRANCH SHRTWV IS LIFTING NEWD INTO THE WRN PLAINS EARLY THIS MRNG AND SUPPORTING A WELL DEFINED BAROCLINIC LEAF CLD...WITH SOME VERY COLD CLD TOPS OVER NEBRASKA AND IOWA JUST TO THE N OF H85 WARM FNT ATTENDANT TO DVLPG SFC LO PRES IN FAR NW KANSAS AND WHERE THERE IS ENHANCED UPR DVGC IN EXIT REGION OF SUPPORTING 140KT H3 JET MAX. IN THE ARCTIC BRANCH...THERE IS A STRONG SHRTWV DIGGING SEWD INTO MANITOBA...WITH 12HR H5 HGT FALLS APRCHG 150M IN THE VIGOROUS DPVA AHEAD OF THIS FEATURE. SFC COLD FNT HANGING S OF THE ACCOMPANYING SFC LO MOVING INTO FAR NW ONTARIO EXTENDS S INTO THE NRN PLAINS AND IS APRCHG NW MN. CLOSER TO HOME... A BAND OF COLDER CLD TOPS IS NOTED NEAR THE WI BORDER ALONG AXIS OF FGEN SHOWN BEST BTWN ABOUT H7-5. HOWEVER...DRYNESS OF ANTECEDENT AIRMASS HAS SO FAR LIMITED THE COVERAGE/INTENSITY OF ACCOMPANYING LIGHT SN. MAIN FCST CONCERNS THIS FCST PERIOD WL BE ON POPS/SN TOTALS ASSOCIATED WITH THE TWO SHRTWVS NOTED ABOVE. SINCE THESE DISTURBANCES WL REMAIN OUT OF PHASE...OVERALL SN TOTALS EXPECTED TODAY OVER UPR MI WL NOT BE EXCESSIVE BEFORE MUCH COLDER AIR FOLLOWING THE ARCTIC BRANCH FROPA SURGES INTO THE AREA TNGT AND BRINGS A RETURN OF SOME LES. TODAY...SRN BRANCH DISTURBANCE IS FCST TO ACCELERATE TO THE NE AND ACROSS THE UPPER MIDWEST IN FAST WSW FLOW BTWN THE TWO BRANCHES AS THE NRN BRANCH SHRTWV PUSHES INTO NW ONTARIO...WITH COLD FNT ATTENDANT TO ACCOMPANY SFC LO REACHING THE WRN CWA LATE IN THE DAY. ARRIVAL OF SOME VIGOROUS DEEP LYR QVECTOR CNVGC/UPR DVGC IN LEFT EXIT OF SUPPORTING H3 JET MAX AS WELL AS DEEP ISENTROPIC ASCENT IN THE SSW FLOW ALF IN ADVANCE OF THESE DISTURBANCES WL CAUSE BAND OF PATCHY SN NEAR THE WI BORDER EARLY RELATED TO MID LVL FGEN TO EXPAND IN COVERAGE DURING THE MRNG HRS. SINCE THE SHARPEST ISENTROPIC ASCENT AS WELL AS FGEN THAT IS MAXIMIZED IN THE H7-6 LYR IS FCST TO IMPACT MAINLY THE SE HALF OF THE CWA...WHERE SOME LK ENHANCEMENT OFF LK MI LIMITED SOMEHWAT BY ICE COVERAGE IS PSBL IN THE LLVL SLY FLOW AHEAD OF THE SFC LO ASSOCIATED WITH THE SRN BRANCH DISTURBANCE... EXPECT THE GREATER SN TOTALS IN THIS AREA. WITH SPECIFIC HUMIDITY IN THE H7-75 LYR UP TO 3G/KG...3-6 INCHES OF SN SEEMS A GOOD BET FOR 6- 9 HR PERIOD OF STEADY PCPN EXPECTED BEFORE ARRIVAL OF DNVA/VIGOROUS QVECTOR DVGC DURING THE MID TO LATE AFTN IN THE WAKE OF THIS DISTURANCE WL BRING AN END TO THE STEADIER SN W-E AND OVER THE FAR E BY 00Z WED. ALTHOUGH THE SHARPER ISENTROPIC ASCENT/FGEN/MSTR TRANSPORT WL TEND TO MISS THE WRN CWA...EXPECTED HIER SN/WATER RATIOS IN THAT AREA DUE TO A DEEPER FCST DGZ MAY HELP RAISE SN TOTALS AT LEAST TO THE 3 INCH THRESHOLD IN THAT AREA. WL MAINTAIN GOING ADVY FOR THE ENTIRE CWA AS IS EVEN THOUGH THE HEADLINE MAY BE DROPPED A FEW HRS EARLY OVER THE W. TNGT...UPR MI WL BE DOMINATED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE IN THE WAKE OF THE DEPARTING DISTURBANCES. BUT ARRIVAL OF COLDER AIR IN THE WAKE OF ARCTIC BRANCH COLD FROPA THAT IS FCST TO DROP H85 TEMPS TO AS LO AS -26C OVER THE W BY 12Z WED WL RESULT IN LES...MAINLY IN AERAS THAT ARE DOWNSTREAM OF HOLES IN THE ICE COVER OBSVED JUST E OF THE MN ARROWHEAD...THE BAYFIELD PENINSULA AND THE KEWEENAW PENINSULA IN THE FCST WNW H925 FLOW. BUT STILL RATHER EXTENSIVE ICE COVER... AS WELL AS DISAPPEARING DGZ OVER THE W RELATED TO THE CHILL OF THE INCOMING AIRMASS...WL HOLD DOWN SN TOTALS. THE BEST CHANCE FOR MORE NMRS SN SHOWERS APPEARS TO BE E OF MUNISING IN ALGER COUNTY THAT WL BE DOWNWIND OF THE AREA OF OPEN WATER E OF THE KEWEENAW AND WHERE THE ONSHORE 290 FLOW WL BE MORE PARALLEL TO THAT AREA OF OPEN WATER. GUSTY WINDS RELATED TO FCST H925 WINDS UP TO 35-40KTS/STRONG CAA AND DESTABILIZATION WL CAUSE SOME GUSTY WINDS...ESPECIALLY NEAR THE LK SUP SHORE. GUSTS IN THE MORE EXPOSED LOCATIONS E OF MUNISING MAY APRCH ADVY CRITERIA. OVER THE SCENTRAL...EXPECT SOME CLEARING...WITH MIN TEMPS FALLING BLO ZERO OVER THE INTERIOR W HALF...ESPECIALLY NEAR THE WI BORDER WHERE LK MODERATION WL BE MINIMAL OR ABSENT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 356 AM EST TUE MAR 3 2015 A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU. FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1149 PM EST MON MAR 2 2015 VFR CONDITIONS WILL GIVE WAY TO MVFR CONDITIONS LATE TONIGHT AT KIWD (AROUND 10Z) AND AT KCMX/KSAW AROUND 12Z AS INCREASING MOISTURE IN A SW FLOW WILL LEAD TO SNOW DEVELOPMENT. BY MID TO LATE MORNING...ALL TERMINALS SHOULD SEE IFR CONDITIONS. EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS LATE AFTERNOON/EVENING (BTWN 20-22Z) WITH DRIER CONDITIONS AND DEVELOPING W WINDS IN WAKE OF LOW PRES TROF/COLD FROPA. W WINDS GUSTING AS HIGH AS 30 MPH AT KCMX COULD LEAD TO SOME BLSN AND POSSIBLY BRIEF IFR CONDITIONS TUE EVENING. EXPECT KSAW TO SEE VFR CONDITIONS DEVELOPING TUE EVENING IN DOWNSLOPE WNW FLOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 410 AM EST TUE MAR 3 2015 S WINDS UP TO 25 KTS TODAY IN ADVANCE OF AN APPROACHING COLD FRONT WILL SHIFT TO THE WNW FOLLOWING THE PASSAGE OF THIS FRONT LATE TODAY/TONIGHT. TIGHTENING PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HI PRES MOVING INTO THE NORTHERN PLAINS WILL BRING A PERIOD OF WNW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. UPGRADED GALE WATCH TO A WARNING FOR THESE AREAS. AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE FORECAST PERIOD. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK THAT WILL OPEN SOME HOLES IN THE ICE...THE SIGNIFICANT ICE COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR MIZ001>007-009>014-084-085. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR LSZ266. GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR LSZ265. GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR LSZ264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 AM EST TUE MAR 3 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 451 PM EST MON MAR 2 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER N AMERICA. FEATURES OF INTEREST FOR THE SHORT TERM FCST ARE A NRN STREAM SHORTWAVE DROPPING THRU ALBERTA/SASKATCHEWAN AND THE SRN STREAM TROF OVER CA/NV...IN PARTICULAR THE SHORTWAVE OVER SRN CA/SRN NV WHERE CONVECTION IS NOTED. THESE TWO WAVES WILL BRING A WIDESPREAD SYNOPTIC SNOW TO THE AREA TUE. ABUNDANT SUNSHINE HAS BEEN THE RULE ACROSS THE AREA THIS AFTN UNDER DRY AIR MASS ASSOCIATED WITH SFC HIGH OVER THE MID MISSISSIPPI VALLEY AND WRN GREAT LAKES REGION. SUNSHINE WORKING ON THE FORESTED TERRAIN OF UPPER MI HAS RESULTED IN TEMPS RISING WELL INTO THE 20S OVER MOST OF THE AREA. COOLEST CONDITIONS (AROUND 20F) ARE OVER THE FAR E...CLOSER TO THE DEPARTING 850MB THERMAL TROF...AND AT MANY LOCATIONS ALONG LAKE SUPERIOR WHERE LAKE/ICE BREEZE HAS DEVELOPED. LATEST MODEL RUNS CONTINUE TO SHOW THE 2 AFOREMENTIONED SHORTWAVES REMAINING UNPHASED AS THEY AFFECT THE AREA TUE. THE SRN WAVE WILL ACCELERATE OUT OF THE SW INTO THE DOWNSTREAM CONFLUENT FLOW...AND IT WILL BE THE DRIVER OF THE SNOW THAT SPREADS INTO THE UPPER LAKES. IT APPEARS 1 MAIN STREAK OF PCPN OR AT LEAST MORE ORGANIZED/HEAVIER PCPN WILL DEVELOP TONIGHT TO THE SW. THIS PCPN WILL STREAK NE ACROSS SD INTO CNTRL MN IN ASSOCIATION WITH A COUPLED UPPER JET STRUCTURE/ENHANCED UPPER DIVERGENCE FROM LEFT EXIT OF 150KT JET TRANSLATING OUT OF THE SRN ROCKIES AND THE RIGHT ENTRANCE OF 125KT JET STREAK OVER ND INTO NRN ONTARIO. MORE PCPN WILL BEGIN TO GET ORGANIZED FARTHER E LATE IN THE NIGHT AS MID LEVEL FRONTOGENESIS AND BROADER WAA/ISENTROPIC ASCENT BEGIN TO SATURATE DRIER AIR AT THE LOWER LEVELS. MODELS ARE NEARLY IDENTICAL IN TIMING THE PCPN INTO WRN AND SRN UPPER MI IN THE 08-12Z TIME FRAME...AND STARTING ACROSS THE N AND E AROUND OR SHORTLY AFTER 12Z. SO...LITTLE ADJUSTMENT WILL BE REQUIRED WITH ONSET TIMING. ACCUMULATIONS AROUND ONE HALF INCH MAY OCCUR ALONG THE WI BORDER BY 12Z. ON TUE...THE BEST UPPER DIVERGENCE ASSOCIATED WITH A WEAKENING COUPLED UPPER JET STRUCTURE QUICKLY SHIFTS NE ACROSS NE MN/WRN LAKE SUPERIOR INTO NRN ONTARIO. MEANWHILE...WAA/ISENTROPIC ASCENT/FRONTOGENETICALLY FORCED PCPN WILL QUICKLY EXPAND/INCREASE IN INTENSITY AS AIR MASS SATURATES AND DEEP LAYER FORCING PROVIDED BY SHORTWAVE ARRIVES. ON THE 285K SFC (ROUGHLY 700-750MB)...MIXING RATIOS AROUND 2.5G/KG ARE AVBL...SUGGESTING SOMETHING AROUND 3 INCHES OF SNOW FOR 6-9HRS OF ASCENT. HOWEVER...GIVEN THE OTHER FACTORS AT PLAY...A WIDESPREAD FAIRLY UNIFORM 3-5 INCH SNOW IS EXPECTED ACROSS THE ENTIRE FCST AREA TUE...WHICH FALLS NICELY INLINE WITH THE CONSENSUS QPF NUMBERS FROM THE MODELS CONVERTED TO SNOW USING A 15 TO 1 OR SO SNOW RATIO. WITH SOUTHERLY LOW-LEVEL FLOW UP LAKE MICHIGAN FOR SEVERAL HRS AND AIR MASS JUST COLD ENOUGH TO SUPPORT ENHANCEMENT...THERE SHOULD BE SOME BOOST TO SNOW TOTALS DOWNWIND OF LAKE MICHIGAN THOUGH ICE COVER WILL LIMIT THE ENHANCEMENT OVER WHAT IT COULD BE. THAT AREA IS MORE LIKELY TO SEE ACCUMULATIONS CLOSER TO 5 INCHES THAN 3...AND NOT OUT OF THE QUESTION THAT SOME 6 INCH AMOUNTS COULD OCCUR. FORCING QUICKLY SHIFTS E TUE AFTN...RESULTING IN SNOW RAPIDLY DIMINISHING W TO E DURING THE MID AND LATE AFTN HRS. IN FACT...IT MAY END COMPLETELY OVER PORTIONS OF THE WEST LATE IN THE AFTN. WITH SNOW RATIO LIKELY UNDER 20 TO 1...THIS SYSTEM WILL ACHIEVE THE WETTER SNOW TYPE ADVY CRITERIA OF AN AVG SNOWFALL OF AT LEAST 3IN/12HR OVER THE ENTIRE FCST AREA. SO...ADVY WILL BE HOISTED ACROSS THE BOARD. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 356 AM EST TUE MAR 3 2015 A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU. FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1149 PM EST MON MAR 2 2015 VFR CONDITIONS WILL GIVE WAY TO MVFR CONDITIONS LATE TONIGHT AT KIWD (AROUND 10Z) AND AT KCMX/KSAW AROUND 12Z AS INCREASING MOISTURE IN A SW FLOW WILL LEAD TO SNOW DEVELOPMENT. BY MID TO LATE MORNING...ALL TERMINALS SHOULD SEE IFR CONDITIONS. EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS LATE AFTERNOON/EVENING (BTWN 20-22Z) WITH DRIER CONDITIONS AND DEVELOPING W WINDS IN WAKE OF LOW PRES TROF/COLD FROPA. W WINDS GUSTING AS HIGH AS 30 MPH AT KCMX COULD LEAD TO SOME BLSN AND POSSIBLY BRIEF IFR CONDITIONS TUE EVENING. EXPECT KSAW TO SEE VFR CONDITIONS DEVELOPING TUE EVENING IN DOWNSLOPE WNW FLOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 451 PM EST MON MAR 2 2015 GENERALLY LIGHT WINDS CURRENTLY ACROSS LAKE SUPERIOR WILL BECOME S AND RAMP UP TONIGHT AND TUE TO 15-25KT IN ADVANCE OF AN APPROACHING LO PRES TROF. ONCE THE TROF PASSES TO THE E TUE NIGHT...TIGHTENING PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HIGH PRES MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF NW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE WEEK. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...THE HIGHER ICE COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ THIS MORNING TO 7 PM EST /6 PM CST/ THIS EVENING FOR MIZ001>007-009>014-084- 085. LAKE SUPERIOR... GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267. GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR LSZ266. GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR LSZ265. GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR LSZ264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST MON MAR 2 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 451 PM EST MON MAR 2 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER N AMERICA. FEATURES OF INTEREST FOR THE SHORT TERM FCST ARE A NRN STREAM SHORTWAVE DROPPING THRU ALBERTA/SASKATCHEWAN AND THE SRN STREAM TROF OVER CA/NV...IN PARTICULAR THE SHORTWAVE OVER SRN CA/SRN NV WHERE CONVECTION IS NOTED. THESE TWO WAVES WILL BRING A WIDESPREAD SYNOPTIC SNOW TO THE AREA TUE. ABUNDANT SUNSHINE HAS BEEN THE RULE ACROSS THE AREA THIS AFTN UNDER DRY AIR MASS ASSOCIATED WITH SFC HIGH OVER THE MID MISSISSIPPI VALLEY AND WRN GREAT LAKES REGION. SUNSHINE WORKING ON THE FORESTED TERRAIN OF UPPER MI HAS RESULTED IN TEMPS RISING WELL INTO THE 20S OVER MOST OF THE AREA. COOLEST CONDITIONS (AROUND 20F) ARE OVER THE FAR E...CLOSER TO THE DEPARTING 850MB THERMAL TROF...AND AT MANY LOCATIONS ALONG LAKE SUPERIOR WHERE LAKE/ICE BREEZE HAS DEVELOPED. LATEST MODEL RUNS CONTINUE TO SHOW THE 2 AFOREMENTIONED SHORTWAVES REMAINING UNPHASED AS THEY AFFECT THE AREA TUE. THE SRN WAVE WILL ACCELERATE OUT OF THE SW INTO THE DOWNSTREAM CONFLUENT FLOW...AND IT WILL BE THE DRIVER OF THE SNOW THAT SPREADS INTO THE UPPER LAKES. IT APPEARS 1 MAIN STREAK OF PCPN OR AT LEAST MORE ORGANIZED/HEAVIER PCPN WILL DEVELOP TONIGHT TO THE SW. THIS PCPN WILL STREAK NE ACROSS SD INTO CNTRL MN IN ASSOCIATION WITH A COUPLED UPPER JET STRUCTURE/ENHANCED UPPER DIVERGENCE FROM LEFT EXIT OF 150KT JET TRANSLATING OUT OF THE SRN ROCKIES AND THE RIGHT ENTRANCE OF 125KT JET STREAK OVER ND INTO NRN ONTARIO. MORE PCPN WILL BEGIN TO GET ORGANIZED FARTHER E LATE IN THE NIGHT AS MID LEVEL FRONTOGENESIS AND BROADER WAA/ISENTROPIC ASCENT BEGIN TO SATURATE DRIER AIR AT THE LOWER LEVELS. MODELS ARE NEARLY IDENTICAL IN TIMING THE PCPN INTO WRN AND SRN UPPER MI IN THE 08-12Z TIME FRAME...AND STARTING ACROSS THE N AND E AROUND OR SHORTLY AFTER 12Z. SO...LITTLE ADJUSTMENT WILL BE REQUIRED WITH ONSET TIMING. ACCUMULATIONS AROUND ONE HALF INCH MAY OCCUR ALONG THE WI BORDER BY 12Z. ON TUE...THE BEST UPPER DIVERGENCE ASSOCIATED WITH A WEAKENING COUPLED UPPER JET STRUCTURE QUICKLY SHIFTS NE ACROSS NE MN/WRN LAKE SUPERIOR INTO NRN ONTARIO. MEANWHILE...WAA/ISENTROPIC ASCENT/FRONTOGENETICALLY FORCED PCPN WILL QUICKLY EXPAND/INCREASE IN INTENSITY AS AIR MASS SATURATES AND DEEP LAYER FORCING PROVIDED BY SHORTWAVE ARRIVES. ON THE 285K SFC (ROUGHLY 700-750MB)...MIXING RATIOS AROUND 2.5G/KG ARE AVBL...SUGGESTING SOMETHING AROUND 3 INCHES OF SNOW FOR 6-9HRS OF ASCENT. HOWEVER...GIVEN THE OTHER FACTORS AT PLAY...A WIDESPREAD FAIRLY UNIFORM 3-5 INCH SNOW IS EXPECTED ACROSS THE ENTIRE FCST AREA TUE...WHICH FALLS NICELY INLINE WITH THE CONSENSUS QPF NUMBERS FROM THE MODELS CONVERTED TO SNOW USING A 15 TO 1 OR SO SNOW RATIO. WITH SOUTHERLY LOW-LEVEL FLOW UP LAKE MICHIGAN FOR SEVERAL HRS AND AIR MASS JUST COLD ENOUGH TO SUPPORT ENHANCEMENT...THERE SHOULD BE SOME BOOST TO SNOW TOTALS DOWNWIND OF LAKE MICHIGAN THOUGH ICE COVER WILL LIMIT THE ENHANCEMENT OVER WHAT IT COULD BE. THAT AREA IS MORE LIKELY TO SEE ACCUMULATIONS CLOSER TO 5 INCHES THAN 3...AND NOT OUT OF THE QUESTION THAT SOME 6 INCH AMOUNTS COULD OCCUR. FORCING QUICKLY SHIFTS E TUE AFTN...RESULTING IN SNOW RAPIDLY DIMINISHING W TO E DURING THE MID AND LATE AFTN HRS. IN FACT...IT MAY END COMPLETELY OVER PORTIONS OF THE WEST LATE IN THE AFTN. WITH SNOW RATIO LIKELY UNDER 20 TO 1...THIS SYSTEM WILL ACHIEVE THE WETTER SNOW TYPE ADVY CRITERIA OF AN AVG SNOWFALL OF AT LEAST 3IN/12HR OVER THE ENTIRE FCST AREA. SO...ADVY WILL BE HOISTED ACROSS THE BOARD. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 402 PM EST MON MAR 2 2015 AT THE START OF THE LONG TERM PERIOD...UPPER MICHIGAN WILL SEE THE SYNOPTIC PRECIPITATION QUICKLY COMING TO AN END OVER THE EASTERN THIRD OF THE CWA. THIS IS DUE TO THE DRY MID LEVEL AIR MOVING OVER THE AREA BEHIND THE COLD FRONT AND AHEAD OF THE MAIN SHORTWAVE TROUGH THAT WILL MOVE THROUGH ON TUESDAY. THEN...AS COLDER AIR SURGES INTO THE AREA...GENERALLY AFTER MIDNIGHT TUESDAY NIGHT...SHOULD SEE THE POTENTIAL FOR LAKE EFFECT INCREASE FROM WEST TO EAST. 850MB TEMPS WILL FALL FROM AROUND -11C AT 00Z WEDNESDAY TO -26C AT 18Z WEDNESDAY...PROVIDING PLENTY OF OVER LAKE INSTABILITY WHERE THERE IS OPEN WATER. THAT IS THE BIG QUESTION FOR THE LAKE EFFECT FORECAST. VISIBLE SATELLITE SHOWS SEVERAL LARGER AREAS OF OPEN WATER AND SLUSH OVER WESTERN...NORTH CENTRAL...AND SOUTH CENTRAL LAKE SUPERIOR. THOSE AREAS HAVE NOT BEEN REPRESENTED IN THE MODELS AT THIS POINT...SO I DON/T FEEL THE MODELS ARE INDICATING THE LAKE EFFECT POTENTIAL IN THE QPF FIELDS. THUS...HAVE PERFORMED SIGNIFICANT HAND EDITS TO THE GRIDS...BOTH IN RAISING POPS AND HIGHLIGHTING AREAS DOWNWIND OF THE CURRENT OPEN WATER AREAS. WITH THE STRONG WEST TO WEST-NORTHWEST WINDS TUESDAY NIGHT INTO WEDNESDAY...THOSE AREAS OF OPEN WATER WILL LIKELY EXPAND AND MOVE...SO THAT DOES INCREASE THE UNCERTAINTY OF THE LAKE EFFECT SOME...BUT EVEN WITH THE COLD AIR...THINK THE WINDS WILL LIMIT THE ICE COVER EXPANDING AT LEAST THROUGH WEDNESDAY. WHILE THE LAKE EFFECT WON/T BE TOO STRONG INITIALLY TUESDAY NIGHT...THE CLOUD WILL BE WITHIN THE DGZ AND LEAD TO A FLUFFY INCH OR SO OF ACCUMULATION. THEN ON WEDNESDAY...INVERSION HEIGHTS WILL RISE TO 7-9KFT AS A SHORTWAVE MOVES THROUGH AND SUPPORT MODERATE TO POTENTIALLY EVEN LOCALLY HEAVY SNOWFALL. WITH THE COLD AIR BEING IN PLACE ON WEDNESDAY...SNOWFLAKE SIZE SHOULD BE SMALL AND KEEP ACCUMULATIONS IN THE COUPLE INCH RANGE FOR THE WEST-NORTHWEST WIND AREAS DOWNWIND OF THE OPEN WATER. IN ADDITION...RECENT SNOWFALL AND THE STRONG WINDS WILL LIKELY LEAD TO PATCHY/AREAS OF BLOWING SNOW...ESPECIALLY OVER THE KEWEENAW AND NEAR LAKE SUPERIOR EAST OF MARQUETTE. WHEN COMBINED WITH THE FINE FLAKED LAKE EFFECT SNOW...THIS WILL LEAD TO VISIBILITIES BEING REDUCED BELOW 1 MILE AND IN THE STRONGER BANDS LIKELY BELOW 1/2MI. FORTUNATELY...WITH WINDS MORE OUT OF THE WEST TO WEST-NORTHWEST...THE IMPACT FOR AREAS EAST OF MARQUETTE WILL BE FOCUSED MORE IN THE AREAS TO THE EAST OF MUNISING AND GENERALLY LESS POPULATED AREAS. HIGH PRESSURE RIDGE WILL BEGIN TO MOVE INTO THE AREA WEDNESDAY NIGHT...DECREASING WINDS AND INCREASING SUBSIDENCE (LOWERING INVERSION HEIGHTS). A WEAK SURFACE TROUGH MOVING OVER EASTERN LAKE SUPERIOR AROUND MIDNIGHT WILL SHIFT WINDS MORE TO THE NORTHWEST FOR A BRIEF PERIOD OF TIME BEFORE BACKING BACK TO THE WEST BY THURSDAY AFTERNOON. WILL SHOW A GRADUALLY DECREASING TREND TO THE POPS FOR THAT TIME PERIOD WHILE FOLLOWING THE WIND DIRECTIONS. SHOULD SEE TEMPERATURES MODERATING BOTH ALOFT AND AT THE SURFACE FRIDAY THROUGH THE WEEKEND AS 500MB FLOW BEGINS TO TURN A LITTLE MORE WEST-NORTHWESTERLY. THIS SHOULD LEAD TO TEMPERATURES WARMING TOWARDS MORE NORMAL VALUES FOR THIS TIME OF YEAR (INTO THE LOWER 30S). BUT THE CONFIDENCE ON PRECIPITATION OCCURRENCE IS LOW DUE TO DIFFERENCES IN THE WAY THE MODELS HANDLE A COUPLE WAVES COMING ON SHORE IN NORTHERN BRITISH COLUMBIA. THE 12Z GFS/GEM SLIDE THE WAVES SOUTHEAST THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY...WITH ANOTHER ONE ARRIVING ON SUNDAY. MEANWHILE...THE 12Z ECMWF SHOWS THE WAVES BECOMING SEPARATED AND SPLITTING THE CWA THROUGH THE WEEKEND. EITHER WAY WITH THE LIMITED DEEP MOISTURE...WOULDN/T EXPECT MUCH MORE THAN LIGHT PRECIP ACCUMULATION THROUGH THE WEEKEND AND WILL ONLY MENTION SLIGHT CHANCES. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH THE AREA SUNDAY NIGHT INTO MONDAY...LIKELY PULLING IN THE LAST SURGE OF COLD AIR FOR A WHILE THROUGH THE AREA. EXPECT THERE TO BE SOME PRECIP ASSOCIATED WITH THE SHORTWAVE...BUT THEN WITH WINDS TURNING NORTHERLY BETWEEN THE DEPARTING SURFACE TROUGH AND A HIGH IN THE DAKOTAS...SHOULD SEE A PERIOD OF LAKE EFFECT IN THE NORMAL SNOW BELTS. WITH THE FAVORABLE 850MB TEMPS (AROUND -14 TO -18C MONDAY)...WILL TREND POPS UP TO MID/HIGH END CHANCES FOR NOW UNTIL WE ARE ABLE TO GET A BETTER HANDLE ON THE ICE SITUATION ON LAKE SUPERIOR. BEHIND THIS WAVE...GFS/ECMWF DETERMINISTIC AND ENSEMBLE MEMBERS ARE SHOWING THE RIDGE THAT HAS BEEN PERSISTENT OVER THE WESTERN CONUS AND ALASKA FOR THE LAST MONTH TO SHIFT EAST INTO THE CENTRAL CONUS AROUND THE MIDDLE OF NEXT WEEK. THIS WILL LEAD TO TEMPERATURES WARMING TO ABOVE NORMAL VALUES AND START MELTING SOME OF THE SNOWPACK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1149 PM EST MON MAR 2 2015 VFR CONDITIONS WILL GIVE WAY TO MVFR CONDITIONS LATE TONIGHT AT KIWD (AROUND 10Z) AND AT KCMX/KSAW AROUND 12Z AS INCREASING MOISTURE IN A SW FLOW WILL LEAD TO SNOW DEVELOPMENT. BY MID TO LATE MORNING...ALL TERMINALS SHOULD SEE IFR CONDITIONS. EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS LATE AFTERNOON/EVENING (BTWN 20-22Z) WITH DRIER CONDITIONS AND DEVELOPING W WINDS IN WAKE OF LOW PRES TROF/COLD FROPA. W WINDS GUSTING AS HIGH AS 30 MPH AT KCMX COULD LEAD TO SOME BLSN AND POSSIBLY BRIEF IFR CONDITIONS TUE EVENING. EXPECT KSAW TO SEE VFR CONDITIONS DEVELOPING TUE EVENING IN DOWNSLOPE WNW FLOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 451 PM EST MON MAR 2 2015 GENERALLY LIGHT WINDS CURRENTLY ACROSS LAKE SUPERIOR WILL BECOME S AND RAMP UP TONIGHT AND TUE TO 15-25KT IN ADVANCE OF AN APPROACHING LO PRES TROF. ONCE THE TROF PASSES TO THE E TUE NIGHT...TIGHTENING PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HIGH PRES MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF NW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE WEEK. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...THE HIGHER ICE COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ TO 7 PM EST /6 PM CST/ TUESDAY FOR MIZ001>007-009>014-084-085. LAKE SUPERIOR... GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR LSZ264>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
1201 PM CST TUE MAR 3 2015 .UPDATE... ISSUED AT 555 AM CST TUE MAR 3 2015 UPDATED AVIATION SECTION BELOW. && .SHORT TERM...(TODAY THROUGH LATE TONIGHT) ISSUED AT 332 AM CST TUE MAR 3 2015 INCOMING WINTER STORM WITH SNOW AND BLOWING SNOW TODAY IS THE PRIMARY CONCERN IN THE SHORT TERM...WITH A SECONDARY FOCUS ON THE VERY COLD AIR EXPECTED TO PUSH IN LATE TONIGHT. SNOW HAS STARTED TO MOVE IN FROM THE SOUTH THIS MORNING WITH THE LATEST RADAR LOOP SHOWING THE RETURNS INCREASING SOUTH OF HIGHWAY TWO AND THE COLUMN QUICKLY BECOMING SATURATED AS THE AREA OF SNOW LIFTS TO THE NORTH. THE LATEST RAP MESO ANALYSIS SHOWS A BAND OF 700MB F-GEN ALONG THE NRN EDGE OF STRONG WAA...AND THE CORRIDOR OF STRONGEST SNOWFALL DIRECTLY IN LINE WITH THIS FORCING. THIS AREA OF F-GEN WILL DEFINE WHERE THE HEAVIEST SNOW WILL OCCUR THIS MORNING...AND IS STILL EXPECTED FROM AROUND THE BRAINERD LAKES/LAKE MILLE LACS AREA NEWD TO THE TWIN PORTS AND INTO PORTIONS OF NW WISCONSIN. A BROAD AREA OF 3 TO 5 INCHES IS EXPECTED IN THIS ZONE. OTHER AREAS TO THE NORTH/NW...AND EVEN TO THE SE...SOUTH OF STATE HIGHWAY 70 IN WI WILL SEE AROUND 1 TO 2 INCHES. THE MOST FAVORABLE TIME FOR ACCUMULATING SNOW WILL STILL BE THIS MORNING FROM AROUND 5 AM TO 11 AM. THE SFC COLD FRONT...CURRENTLY MOVING INTO FAR NW MN WILL MOVE ACROSS THE NORTHLAND THIS AFTERNOON AND ALLOW THE WINDS TO SHIFT FROM SW TO NW. THIS FRONT WILL ALSO BRING WITH IT VERY GUSTY WINDS. STILL EXPECTING SUSTAINED WINDS AROUND 10 TO 20 MPH AND GUSTS AROUND 30 MPH LATE THIS AFTERNOON THROUGH THE EVENING. THE COMBINATION OF THE INITIAL SNOW THIS MORNING...AND BLOWING SNOW LATER TODAY WILL KEEP CONDITIONS HAZARDOUS THROUGH MIDNIGHT TONIGHT. NO CHANGES...SPATIAL OR TIMING...HAVE BEEN MADE TO THE WINTER WEATHER ADVISORIES. THE SNOW WILL TAPER OFF DURING THE EVENING AND OVERNIGHT HOURS TONIGHT FROM WEST TO EAST WITH THE COLD AIR BEHIND THE FRONT POURING IN ACROSS THE UPPER MIDWEST. 850MB TEMPS FROM -25 TO -28 DEG C ARE EXPECTED WITH THIS AIR MASS. THIS WILL ALLOW SFC TEMPERATURES WILL FALL INTO THE SINGLE DIGITS AND TEENS BELOW ZERO...AND THE COMBINATION OF GUSTY NW WINDS WILL PRODUCE WIND CHILLS IN THE -25 TO -35 F RANGE. WILL LIKELY NEED A WIND CHILL ADVISORY OVER MUCH OF THE FORECAST AREA TONIGHT/WED MORNING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 332 AM CST TUE MAR 3 2015 WEDNESDAY TO BE A COLD AND BLUSTERY DAY WITH THE STRONG SURFACE LOW MOVING NORTHEAST ACROSS QUEBEC. AN INVERTED TROUGH WILL EXTEND WEST FROM THIS LOW...AND SLOWLY SAG SOUTHEAST ACROSS THE FORECAST AREA DURING THE DAY. A STRONG SURFACE HIGH WILL BUILD DOWN THE PLAINS DURING THE DAY AS WELL. EXPECT THAT WE WILL SEE FLURRIES OR LIGHT SNOW IN THE VICINITY OF THE TROUGH AXIS...AND AM CARRYING SOME SMALL POPS FOR THIS ALONG WITH CLOUDY SKIES. WITH THE PRESSURE GRADIENT STILL FAIRLY STEEP SURFACE WINDS WILL REMAIN IN THE 10-15MPH RANGE WITH GUSTS IN THE 20-25MPH RANGE...ESPECIALLY IN EXPOSED AREAS. WEDNESDAY NIGHT THE SURFACE RIDGE BUILDS INTO THE AREA A LITTLE MORE AND ALLOWS THE PRESSURE GRADIENT TO WEAKEN...AND THE CLOUDS AND FLURRIES ARE PULLED OFF TO THE EAST WITH THE SURFACE LOW. THERE MAY BE SOME LAKE EFFECT SNOW AFFECTING THE SOUTH SHORE EAST OF ASHLAND... BUT WIND TRAJECTORY IS NOT THE MOST FAVORABLE AND HAVE KEPT POPS LOW. TEMPERATURES TO BOTTOM OUT IN THE NEGATIVE TEENS FOR MANY LOCATIONS...AND WITH THE LIGHT NORTHWEST WINDS IT LOOKS LIKE WE MAY NEED A WIND CHILL ADVISORY FOR WEDNESDAY NIGHT AND THURSDAY MORNING. FOR NOW WILL DISCUSS IN HWO...AND WILL HAVE TO RE-EVALUATE AS WE GET CLOSER IN. THURSDAY SOME STRONG WARM AIR ADVECTION SETS IN ALOFT AND HIGHS SHOULD RISE INTO THE 10-15 DEGREE RANGE...IF NOT WARMER. OTHERWISE QUIET WEATHER IS EXPECTED WITH THE SURFACE RIDGE IN THE VICINITY. ANOTHER SHORTWAVE IS DUE TO MOVE THROUGH THURSDAY NIGHT AND FRIDAY. FOR NOW AM NOT CARRYING ANY SNOW CHANCES BUT WOULD NOT BE SURPRISED TO SEE FLURRIES. CURRENTLY HAVE HIGHS FRIDAY UP IN LOWER TO MIDDLE 30S. INITIALLY THIS WARMING SEEMS OVERDONE COMPARED TO THURSDAY. HOWEVER...PURE MIXING TECHNIQUES WOULD INDICATE MID 20S TO LOW 30S...AND THEN YOU ADD IN SOME SUNSHINE AND OUR DARK TREES AND SUDDENLY THOSE LOW TO MIDDLE 30S SEEM MORE REASONABLE. THE WEEKEND LOOKS QUESTIONABLE WITH A SERIES OF SHORTWAVES DROPPING DOWN ACROSS THE AREA IN UPPER LEVEL NORTHWEST FLOW. MODELS ARE BRINGING SOME WARM 850MB TEMPERATURES INTO THE AREA ALOFT...BUT WITH THE INCREASED CLOUD COVER ASSOCIATED WITH THE CLIPPERS...AND OUR DECENT SNOWPACK...AM WONDERING IF WE MIGHT NOT GET A BUNCH OF STRATUS AND FOG AND COOLER TEMPERATURES INSTEAD OF SUNSHINE AND MID 30S. HAVE LEFT CONSENSUS ALONE IN THIS LOW CONFIDENCE SITUATION... BUT WE WILL NEED TO WATCH THIS CAREFULLY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1158 AM CST TUE MAR 3 2015 THE STORM SYSTEM THAT BROUGHT THE ACCUMULATING SNOW TO THE NORTHLAND WILL CONTINUE TO PULL OFF THROUGHOUT THE DAY AND INTO TONIGHT. STRONG CAA AND GUSTY WINDS WILL BE FOUND IN THE WAKE OF THE DEPARTING SYSTEM. VLIFR TO IFR CONDITIONS WILL QUICKLY TRANSITION TO MVFR AND EVEN SOME VFR AS THE DAY WEARS ON. WITH THE PASSAGE OF A SYSTEM SUCH AS THIS...THERE ARE OFTEN SOME LINGERING CLOUD STREETS AND SPOTTY FLURRIES OR SNOW SHOWERS. THIS COULD MEAN SOME LOCAL MVFR CIGS/VSBYS TONIGHT OR EVEN ON WEDNESDAY MORNING. && .PRELIMINARY POINT TEMPS/POPS... DLH 25 -9 4 -11 / 100 10 10 0 INL 24 -15 3 -19 / 60 10 10 0 BRD 22 -11 5 -14 / 100 10 10 0 HYR 27 -8 6 -15 / 100 10 20 10 ASX 28 -4 7 -8 / 100 20 20 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ011- 012-018-019-021-025-026. WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ020- 033>038. WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001>004-006>009. LS...NONE. && $$ UPDATE...LE SHORT TERM...BJT LONG TERM...LE AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
556 AM CST TUE MAR 3 2015 .UPDATE... ISSUED AT 555 AM CST TUE MAR 3 2015 UPDATED AVIATION SECTION BELOW. && .SHORT TERM...(TODAY THROUGH LATE TONIGHT) ISSUED AT 332 AM CST TUE MAR 3 2015 INCOMING WINTER STORM WITH SNOW AND BLOWING SNOW TODAY IS THE PRIMARY CONCERN IN THE SHORT TERM...WITH A SECONDARY FOCUS ON THE VERY COLD AIR EXPECTED TO PUSH IN LATE TONIGHT. SNOW HAS STARTED TO MOVE IN FROM THE SOUTH THIS MORNING WITH THE LATEST RADAR LOOP SHOWING THE RETURNS INCREASING SOUTH OF HIGHWAY TWO AND THE COLUMN QUICKLY BECOMING SATURATED AS THE AREA OF SNOW LIFTS TO THE NORTH. THE LATEST RAP MESO ANALYSIS SHOWS A BAND OF 700MB F-GEN ALONG THE NRN EDGE OF STRONG WAA...AND THE CORRIDOR OF STRONGEST SNOWFALL DIRECTLY IN LINE WITH THIS FORCING. THIS AREA OF F-GEN WILL DEFINE WHERE THE HEAVIEST SNOW WILL OCCUR THIS MORNING...AND IS STILL EXPECTED FROM AROUND THE BRAINERD LAKES/LAKE MILLE LACS AREA NEWD TO THE TWIN PORTS AND INTO PORTIONS OF NW WISCONSIN. A BROAD AREA OF 3 TO 5 INCHES IS EXPECTED IN THIS ZONE. OTHER AREAS TO THE NORTH/NW...AND EVEN TO THE SE...SOUTH OF STATE HIGHWAY 70 IN WI WILL SEE AROUND 1 TO 2 INCHES. THE MOST FAVORABLE TIME FOR ACCUMULATING SNOW WILL STILL BE THIS MORNING FROM AROUND 5 AM TO 11 AM. THE SFC COLD FRONT...CURRENTLY MOVING INTO FAR NW MN WILL MOVE ACROSS THE NORTHLAND THIS AFTERNOON AND ALLOW THE WINDS TO SHIFT FROM SW TO NW. THIS FRONT WILL ALSO BRING WITH IT VERY GUSTY WINDS. STILL EXPECTING SUSTAINED WINDS AROUND 10 TO 20 MPH AND GUSTS AROUND 30 MPH LATE THIS AFTERNOON THROUGH THE EVENING. THE COMBINATION OF THE INITIAL SNOW THIS MORNING...AND BLOWING SNOW LATER TODAY WILL KEEP CONDITIONS HAZARDOUS THROUGH MIDNIGHT TONIGHT. NO CHANGES...SPATIAL OR TIMING...HAVE BEEN MADE TO THE WINTER WEATHER ADVISORIES. THE SNOW WILL TAPER OFF DURING THE EVENING AND OVERNIGHT HOURS TONIGHT FROM WEST TO EAST WITH THE COLD AIR BEHIND THE FRONT POURING IN ACROSS THE UPPER MIDWEST. 850MB TEMPS FROM -25 TO -28 DEG C ARE EXPECTED WITH THIS AIR MASS. THIS WILL ALLOW SFC TEMPERATURES WILL FALL INTO THE SINGLE DIGITS AND TEENS BELOW ZERO...AND THE COMBINATION OF GUSTY NW WINDS WILL PRODUCE WIND CHILLS IN THE -25 TO -35 F RANGE. WILL LIKELY NEED A WIND CHILL ADVISORY OVER MUCH OF THE FORECAST AREA TONIGHT/WED MORNING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 332 AM CST TUE MAR 3 2015 WEDNESDAY TO BE A COLD AND BLUSTERY DAY WITH THE STRONG SURFACE LOW MOVING NORTHEAST ACROSS QUEBEC. AN INVERTED TROUGH WILL EXTEND WEST FROM THIS LOW...AND SLOWLY SAG SOUTHEAST ACROSS THE FORECAST AREA DURING THE DAY. A STRONG SURFACE HIGH WILL BUILD DOWN THE PLAINS DURING THE DAY AS WELL. EXPECT THAT WE WILL SEE FLURRIES OR LIGHT SNOW IN THE VICINITY OF THE TROUGH AXIS...AND AM CARRYING SOME SMALL POPS FOR THIS ALONG WITH CLOUDY SKIES. WITH THE PRESSURE GRADIENT STILL FAIRLY STEEP SURFACE WINDS WILL REMAIN IN THE 10-15MPH RANGE WITH GUSTS IN THE 20-25MPH RANGE...ESPECIALLY IN EXPOSED AREAS. WEDNESDAY NIGHT THE SURFACE RIDGE BUILDS INTO THE AREA A LITTLE MORE AND ALLOWS THE PRESSURE GRADIENT TO WEAKEN...AND THE CLOUDS AND FLURRIES ARE PULLED OFF TO THE EAST WITH THE SURFACE LOW. THERE MAY BE SOME LAKE EFFECT SNOW AFFECTING THE SOUTH SHORE EAST OF ASHLAND... BUT WIND TRAJECTORY IS NOT THE MOST FAVORABLE AND HAVE KEPT POPS LOW. TEMPERATURES TO BOTTOM OUT IN THE NEGATIVE TEENS FOR MANY LOCATIONS...AND WITH THE LIGHT NORTHWEST WINDS IT LOOKS LIKE WE MAY NEED A WIND CHILL ADVISORY FOR WEDNESDAY NIGHT AND THURSDAY MORNING. FOR NOW WILL DISCUSS IN HWO...AND WILL HAVE TO RE-EVALUATE AS WE GET CLOSER IN. THURSDAY SOME STRONG WARM AIR ADVECTION SETS IN ALOFT AND HIGHS SHOULD RISE INTO THE 10-15 DEGREE RANGE...IF NOT WARMER. OTHERWISE QUIET WEATHER IS EXPECTED WITH THE SURFACE RIDGE IN THE VICINITY. ANOTHER SHORTWAVE IS DUE TO MOVE THROUGH THURSDAY NIGHT AND FRIDAY. FOR NOW AM NOT CARRYING ANY SNOW CHANCES BUT WOULD NOT BE SURPRISED TO SEE FLURRIES. CURRENTLY HAVE HIGHS FRIDAY UP IN LOWER TO MIDDLE 30S. INITIALLY THIS WARMING SEEMS OVERDONE COMPARED TO THURSDAY. HOWEVER...PURE MIXING TECHNIQUES WOULD INDICATE MID 20S TO LOW 30S...AND THEN YOU ADD IN SOME SUNSHINE AND OUR DARK TREES AND SUDDENLY THOSE LOW TO MIDDLE 30S SEEM MORE REASONABLE. THE WEEKEND LOOKS QUESTIONABLE WITH A SERIES OF SHORTWAVES DROPPING DOWN ACROSS THE AREA IN UPPER LEVEL NORTHWEST FLOW. MODELS ARE BRINGING SOME WARM 850MB TEMPERATURES INTO THE AREA ALOFT...BUT WITH THE INCREASED CLOUD COVER ASSOCIATED WITH THE CLIPPERS...AND OUR DECENT SNOWPACK...AM WONDERING IF WE MIGHT NOT GET A BUNCH OF STRATUS AND FOG AND COOLER TEMPERATURES INSTEAD OF SUNSHINE AND MID 30S. HAVE LEFT CONSENSUS ALONE IN THIS LOW CONFIDENCE SITUATION... BUT WE WILL NEED TO WATCH THIS CAREFULLY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 555 AM CST TUE MAR 3 2015 BAND OF SNOW WITH IFR TO LIFR CEILINGS AND VISIBILITIES TO CONTINUE TO AFFECT KBRD...KDLH...KHIB AND KHYR UNTIL 18Z-21Z. KINL TO ONLY GET IFR VISIBILITIES AND MVFR CEILINGS WITH THIS BAND. NORTHWEST WINDS TO INCREASE TO 15-20KTS WITH GUSTS TO 25KTS AFTER 18Z...AND THOUGH SNOW EXPECTED TO END...BLOWING SNOW WILL KEEP VISIBILITIES MVFR. CONDITIONS TO SLOWLY IMPROVE TO VFR AROUND 21Z OR SHORTLY AFTER. WINDS TO DIMINISH AGAIN BETWEEN 04Z AND 08Z. && .PRELIMINARY POINT TEMPS/POPS... DLH 25 -9 4 -11 / 100 10 10 0 INL 19 -15 3 -19 / 60 10 10 0 BRD 22 -11 5 -14 / 100 10 10 0 HYR 27 -8 6 -15 / 100 10 20 10 ASX 28 -4 7 -8 / 100 20 20 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT FOR MNZ011-012-018-019-021-025-026. WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ020- 033>038. WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001>004-006>009. LS...NONE. && $$ UPDATE...LE SHORT TERM...BJT LONG TERM...LE AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
335 AM CST TUE MAR 3 2015 .SHORT TERM...(TODAY THROUGH LATE TONIGHT) ISSUED AT 332 AM CST TUE MAR 3 2015 INCOMING WINTER STORM WITH SNOW AND BLOWING SNOW TODAY IS THE PRIMARY CONCERN IN THE SHORT TERM...WITH A SECONDARY FOCUS ON THE VERY COLD AIR EXPECTED TO PUSH IN LATE TONIGHT. SNOW HAS STARTED TO MOVE IN FROM THE SOUTH THIS MORNING WITH THE LATEST RADAR LOOP SHOWING THE RETURNS INCREASING SOUTH OF HIGHWAY TWO AND THE COLUMN QUICKLY BECOMING SATURATED AS THE AREA OF SNOW LIFTS TO THE NORTH. THE LATEST RAP MESO ANALYSIS SHOWS A BAND OF 700MB F-GEN ALONG THE NRN EDGE OF STRONG WAA...AND THE CORRIDOR OF STRONGEST SNOWFALL DIRECTLY IN LINE WITH THIS FORCING. THIS AREA OF F-GEN WILL DEFINE WHERE THE HEAVIEST SNOW WILL OCCUR THIS MORNING...AND IS STILL EXPECTED FROM AROUND THE BRAINERD LAKES/LAKE MILLE LACS AREA NEWD TO THE TWIN PORTS AND INTO PORTIONS OF NW WISCONSIN. A BROAD AREA OF 3 TO 5 INCHES IS EXPECTED IN THIS ZONE. OTHER AREAS TO THE NORTH/NW...AND EVEN TO THE SE...SOUTH OF STATE HIGHWAY 70 IN WI WILL SEE AROUND 1 TO 2 INCHES. THE MOST FAVORABLE TIME FOR ACCUMULATING SNOW WILL STILL BE THIS MORNING FROM AROUND 5 AM TO 11 AM. THE SFC COLD FRONT...CURRENTLY MOVING INTO FAR NW MN WILL MOVE ACROSS THE NORTHLAND THIS AFTERNOON AND ALLOW THE WINDS TO SHIFT FROM SW TO NW. THIS FRONT WILL ALSO BRING WITH IT VERY GUSTY WINDS. STILL EXPECTING SUSTAINED WINDS AROUND 10 TO 20 MPH AND GUSTS AROUND 30 MPH LATE THIS AFTERNOON THROUGH THE EVENING. THE COMBINATION OF THE INITIAL SNOW THIS MORNING...AND BLOWING SNOW LATER TODAY WILL KEEP CONDITIONS HAZARDOUS THROUGH MIDNIGHT TONIGHT. NO CHANGES...SPATIAL OR TIMING...HAVE BEEN MADE TO THE WINTER WEATHER ADVISORIES. THE SNOW WILL TAPER OFF DURING THE EVENING AND OVERNIGHT HOURS TONIGHT FROM WEST TO EAST WITH THE COLD AIR BEHIND THE FRONT POURING IN ACROSS THE UPPER MIDWEST. 850MB TEMPS FROM -25 TO -28 DEG C ARE EXPECTED WITH THIS AIR MASS. THIS WILL ALLOW SFC TEMPERATURES WILL FALL INTO THE SINGLE DIGITS AND TEENS BELOW ZERO...AND THE COMBINATION OF GUSTY NW WINDS WILL PRODUCE WIND CHILLS IN THE -25 TO -35 F RANGE. WILL LIKELY NEED A WIND CHILL ADVISORY OVER MUCH OF THE FORECAST AREA TONIGHT/WED MORNING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 332 AM CST TUE MAR 3 2015 WEDNESDAY TO BE A COLD AND BLUSTERY DAY WITH THE STRONG SURFACE LOW MOVING NORTHEAST ACROSS QUEBEC. AN INVERTED TROUGH WILL EXTEND WEST FROM THIS LOW...AND SLOWLY SAG SOUTHEAST ACROSS THE FORECAST AREA DURING THE DAY. A STRONG SURFACE HIGH WILL BUILD DOWN THE PLAINS DURING THE DAY AS WELL. EXPECT THAT WE WILL SEE FLURRIES OR LIGHT SNOW IN THE VICINITY OF THE TROUGH AXIS...AND AM CARRYING SOME SMALL POPS FOR THIS ALONG WITH CLOUDY SKIES. WITH THE PRESSURE GRADIENT STILL FAIRLY STEEP SURFACE WINDS WILL REMAIN IN THE 10-15MPH RANGE WITH GUSTS IN THE 20-25MPH RANGE...ESPECIALLY IN EXPOSED AREAS. WEDNESDAY NIGHT THE SURFACE RIDGE BUILDS INTO THE AREA A LITTLE MORE AND ALLOWS THE PRESSURE GRADIENT TO WEAKEN...AND THE CLOUDS AND FLURRIES ARE PULLED OFF TO THE EAST WITH THE SURFACE LOW. THERE MAY BE SOME LAKE EFFECT SNOW AFFECTING THE SOUTH SHORE EAST OF ASHLAND... BUT WIND TRAJECTORY IS NOT THE MOST FAVORABLE AND HAVE KEPT POPS LOW. TEMPERATURES TO BOTTOM OUT IN THE NEGATIVE TEENS FOR MANY LOCATIONS...AND WITH THE LIGHT NORTHWEST WINDS IT LOOKS LIKE WE MAY NEED A WIND CHILL ADVISORY FOR WEDNESDAY NIGHT AND THURSDAY MORNING. FOR NOW WILL DISCUSS IN HWO...AND WILL HAVE TO RE-EVALUATE AS WE GET CLOSER IN. THURSDAY SOME STRONG WARM AIR ADVECTION SETS IN ALOFT AND HIGHS SHOULD RISE INTO THE 10-15 DEGREE RANGE...IF NOT WARMER. OTHERWISE QUIET WEATHER IS EXPECTED WITH THE SURFACE RIDGE IN THE VICINITY. ANOTHER SHORTWAVE IS DUE TO MOVE THROUGH THURSDAY NIGHT AND FRIDAY. FOR NOW AM NOT CARRYING ANY SNOW CHANCES BUT WOULD NOT BE SURPRISED TO SEE FLURRIES. CURRENTLY HAVE HIGHS FRIDAY UP IN LOWER TO MIDDLE 30S. INITIALLY THIS WARMING SEEMS OVERDONE COMPARED TO THURSDAY. HOWEVER...PURE MIXING TECHNIQUES WOULD INDICATE MID 20S TO LOW 30S...AND THEN YOU ADD IN SOME SUNSHINE AND OUR DARK TREES AND SUDDENLY THOSE LOW TO MIDDLE 30S SEEM MORE REASONABLE. THE WEEKEND LOOKS QUESTIONABLE WITH A SERIES OF SHORTWAVES DROPPING DOWN ACROSS THE AREA IN UPPER LEVEL NORTHWEST FLOW. MODELS ARE BRINGING SOME WARM 850MB TEMPERATURES INTO THE AREA ALOFT...BUT WITH THE INCREASED CLOUD COVER ASSOCIATED WITH THE CLIPPERS...AND OUR DECENT SNOWPACK...AM WONDERING IF WE MIGHT NOT GET A BUNCH OF STRATUS AND FOG AND COOLER TEMPERATURES INSTEAD OF SUNSHINE AND MID 30S. HAVE LEFT CONSENSUS ALONE IN THIS LOW CONFIDENCE SITUATION... BUT WE WILL NEED TO WATCH THIS CAREFULLY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1137 PM CST MON MAR 2 2015 VFR CONDITIONS THROUGH 09Z...THEN LOWERING CEILINGS AS SNOW SPREADS NORTH AND EAST ACROSS THE FORECAST AREA THROUGH DAYBREAK. A 4-6 HOUR WINDOW OF HEAVY SNOW AND LIFR/VLIFR CONDITIONS WILL BE FOUND AT KBRD/KDLH/KHYR WITH THE SNOW INTENSITY AND AMOUNTS DECREASING NORTHWARD FOR THE KHIB AND KINL AREAS. THE MAIN PERIOD OF ACCUMULATING SNOW WILL END IN THE AFTERNOON...FOLLOWED BY STRONG NORTHWEST WINDS GUSTING AROUND 30 KT THROUGH THE EVENING. && .PRELIMINARY POINT TEMPS/POPS... DLH 25 -9 4 -11 / 100 10 10 0 INL 19 -15 3 -19 / 60 10 10 0 BRD 22 -11 5 -14 / 100 10 10 0 HYR 27 -8 6 -15 / 100 10 20 10 ASX 28 -4 7 -8 / 100 20 20 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT FOR MNZ011-012-018-019-021-025-026. WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ020- 033>038. WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001>004-006>009. LS...NONE. && $$ SHORT TERM...BJT LONG TERM...LE AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS BILLINGS MT
251 PM MST TUE MAR 3 2015 .SHORT TERM...VALID FOR WED AND THU... WEATHER SYSTEM LAST NIGHT CARVED OUT A NICE CYCLONIC FLOW OVER OUR REGION. THERE IS STILL SOME WEAK ENERGY ALOFT IN THE FLOW WHICH WILL DROP THROUGH OUR FORECAST AREA TONIGHT...BUT THERE IS LITTLE IF ANY LOW LEVEL RESPONSE. SO I ANTICIPATE SOME LIGHT SNOW OF PERHAPS FLURRIES IN THE EASTERN BORDER COUNTIES. FURTHER WEST...THE HRRR IS PAINTING SOME VERY LIGHT QPF OVER THE HIGHER TERRAIN. THIS IS SUPPORTED SOMEWHAT BY THE GFS. SO I DID ADD SOME SPOTTY LOW POPS OVER THE BEARTOOTHS AND NEARBY ADJACENT AREAS OVERNIGHT. THE BRISK WIND OVER THE COLD AIR MASS DOES DRIVE DOWN THE WIND CHILLS OUT EAST. AS SUCH I WILL ISSUE A WIND CHILL ADVISORY FOR FALLON AND CARTER COUNTIES FROM 11 PM TO 11 AM WEDNESDAY. TOMORROW...WE BEGIN TO TRANSITION TO A MORE CYCLONIC FLOW ALOFT AND SURFACE FLOW WILL SWITCH TO A WESTERLY DOWNSLOPE LATE. THIS WILL LEAD TO SOME WARMING OVER TODAYS HIGHS. I AM GOING LOWER THAN GUIDANCE THROUGH WEDNESDAY IN THE FOOTHILLS DUE TO THE DEEP NEW SNOW THERE. ELSEWHERE...WE MAY BE ABLE TO MELT OFF MOST OF THE SNOW NOW THAT WE ARE IN TO EARLY MARCH. EVEN BETTER WARM UP FOR THURSDAY AS WESTERLY SURFACE FLOW STRENGTHENS AND FLOW ALOFT TURNS ANTI-CYCLONIC OVER THE ENTIRE FORECAST AREA. LOOK FOR BRISK WINDS IN THE GAP LOCATIONS THURSDAY ...BUT DOES NOT LOOK QUITE STRONG ENOUGH FOR ADVISORY HIGHLIGHTS. BT .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... EXTENDED FORECAST LOOKS TO BE IN GOOD SHAPE SO ONLY MADE A FEW MINOR TWEAKS WITH THIS ISSUANCE. A NORTHWEST TO WEST FLOW ALOFT WILL BE OVER THE FORECAST AREA THROUGH THE PERIOD. MODELS BRING A WEAK DISTURBANCE ACROSS EASTERN MONTANA AND THE DAKOTAS FRIDAY NIGHT. THIS IS INCONSISTENT WITH WHAT THEY WERE SHOWING YESTERDAY WITH THE DISTURBANCE BEING FURTHER WEST. IN ANY CASE...REMOVED POPS FROM THE WEST FRIDAY AND ADDED A SLIGHT CHANCE FOR A SNOW SHOWER TO THE EAST FRIDAY NIGHT. OTHER THAN THIS SYSTEM...DRY WEATHER ALONG WITH ABOVE NORMAL TEMPERATURES LOOK TO BE IN STORE FOR THE WEEKEND INTO NEXT WEEK. AFTERNOON TEMPERATURES WILL BE IN THE LOWER 50S FOR THE WEEKEND WARMING INTO THE UPPER 50S EARLY NEXT WEEK. HOOLEY && .AVIATION... SKIES WILL BE MOSTLY CLEAR TO PARTLY CLOUDY WITH VFR CONDITIONS PREVAILING THIS EVENING AND THROUGH THE OVERNIGHT HOURS. THE EXCEPTION WILL BE FROM KMLS TO KBHK WHERE AN ISOLATED SNOW SHOWER AND MVFR CONDITION WILL BE POSSIBLE. HOOLEY && .PRELIMINARY POINT TEMP/POPS... WED THU FRI SAT SUN MON TUE ----------------------------------------------------------- BIL 004/029 016/046 029/050 029/050 030/054 033/058 033/058 00/B 00/N 01/B 21/B 10/B 00/U 00/U LVM 001/031 022/044 029/048 028/049 030/052 031/055 033/056 10/B 00/N 01/B 21/B 00/B 00/U 00/U HDN 002/028 012/047 025/051 026/051 028/055 030/059 030/059 00/U 00/B 01/B 21/B 10/B 00/U 00/U MLS 901/019 006/046 025/048 027/048 028/051 029/055 032/057 20/U 00/B 01/B 21/B 10/B 00/U 00/U 4BQ 902/018 003/042 020/047 024/047 026/051 027/056 029/057 10/B 00/B 00/B 21/B 10/B 00/U 00/U BHK 903/012 000/041 021/046 024/045 025/047 026/051 029/053 20/B 00/B 01/B 21/B 11/B 00/U 00/U SHR 907/018 005/041 021/045 022/044 024/050 027/055 029/056 00/U 00/U 01/B 21/B 00/B 00/U 00/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...WIND CHILL ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 11 AM MST WEDNESDAY FOR ZONES 33-37. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
327 PM CST TUE MAR 3 2015 .SYNOPSIS... ISSUED AT 330 PM CST TUE MAR 3 2015 AT H5 CLOSED LOW OVER WINNIPEG WITH TROUGH EXTENDING SOUTHWEST INTO SOUTHERN CALIFORNIA. HIGH OVER THE GULF OF MEXICO AD RIDGE OVER THE EASTERN PACIFIC. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 330 PM CST TUE MAR 3 2015 WATER VAPOR IMAGERY SHOWS A THE NEXT SHORTWAVE ACROSS SOUTHWEST WYOMING/NORTHWEST COLORADO LATE THIS AFTERNOON. THIS WAVE WILL TRANSLATE EAST ACROSS THE AREA TONIGHT...WITH CHANCES FOR SNOW INCREASING THIS EVENING AND OVERNIGHT ACROSS WEST CENTRAL THROUGH SOUTHWEST NEBRASKA. IT SHOULD REMAIN DRY ACROSS NORTHERN NEBRASKA. MODELS AGREE THAT A NARROW BAND OF LIGHT TO PERHAPS MODERATE SNOW WILL DEVELOP FROM NORTHEAST COLORADO...EASTWARD ACROSS FAR SOUTHWEST NEBRASKA AND INTO FAR SOUTH CENTRAL NEBRASKA LATE THIS EVENING. THE BAND WILL NOT LAST LONG...AROUND 3 OR 4 HOURS. COULD SEE AN INCH OR TWO WITHIN THIS BAND. INITIALLY CROSS SECTIONS INDICATE DRY AIR IN THE LOWER LEVELS OF THE ATMOSPHERE...AND THIS IS CURRENTLY SUPPORTED BY 20 DEGREE PLUS TEMPERATURE/DEW POINT SPREADS. AS THE SYSTEM MOVES EAST INTO THE AREA BY LATE EVENING...DEEP LIFT WILL INCREASE...MAXIMIZED ACROSS FAR SOUTHWEST NEBRASKA BY AROUND 06Z OR SO. LIFT WILL BE WEAKER TO THE NORTH TOWARD INTERSTATE 80. SHOULD SEE A FAIRLY QUICK TOP DOWN SATURATION LATE THIS EVENING...ESPECIALLY ACROSS FAR SOUTHWEST NEBRASKA WHERE THE STRONGER LIFT WILL BE LOCATED. THE LATEST RAP MODEL INDICATES A LITTLE BETTER LIFT WITHIN THE DGZ /EARLIER MODEL RUNS WERE JUST ABOVE THE DGZ/ SO THAT GAVE A BOOST OF CONFIDENCE...AND WILL TAKE LOW END LIKELY POPS ALL THE WAY NORTH INTO THE INTERSTATE 80 CORRIDOR REGION...WHICH IS SUPPORTED BY THE NEW 18Z NAM MODEL RUN. CLOUDS WILL GRADUALLY DECREASE WEDNESDAY...AS DRIER AIR ALOFT ADVECTS INTO THE AREA THROUGH THE DAY. WINDS WILL ALSO BE ON THE DECREASE. STILL PRETTY COLD WEDNESDAY...WITH H850MB NOT WARMING MUCH THROUGH THE DAY...AND STAYING WELL BELOW ZERO. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 PM CST TUE MAR 3 2015 MODELS IN GOOD AGREEMENT IN THE MID AND LONG TERM SOLUTIONS AND HAVE GOOD CONFIDENCE IN THE FORECAST. CAN SEE SOME SNOW ON THE GROUND OVER NORTHERN SHERIDAN COUNTY THROUGH CENTRAL CHERRY COUNTY BUT OVER THE REMAINDER OF THE FORECAST AREA GROUND LOOKS PRETTY BARE. WEDNESDAY NIGHT HAVE LOWS IN THE SINGLE DIGITS WITH BELOW ZERO TEMPERATURES OVER NORTHERN SHERIDAN COUNTY. 850MB TEMPERATURES RISING THROUGH THE DAY ON THURSDAY AS UPPER TROUGH MOVES EAST AND WARMER DRIER AIR MOVES EAST INTO THE FORECAST AREA. QUASI BLOCK ALONG THE WEST COAST WILL SLOW PROGRESSION OF UPPER PATTERN LEAVING NORTHERN PLAINS IN FAST NORTHWEST FLOW. WEAK WAVE WILL MOVE THROUGH NORTHWEST PATTERN SATURDAY WITH MAINLY JUST A WIND SHIFT. TEMPERATURES RISING INTO THE 50S. ANOTHER WEAK WAVE MOVING THROUGH SUNDAY NIGHT WILL PULL ANOTHER WEAK COOL FRONT THROUGH THE FORECAST MONDAY DRY. TEMPERATURES WILL CONTINUE SLOW CLIMB THROUGH THE COMING WEEK AND DRY FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1144 AM CST TUE MAR 3 2015 AN UPPER LEVEL DISTURBANCE CURRENTLY LOCATED NEAR KSLC...WILL MOVE EAST ACROSS SOUTHERN WY AND NORTHERN CO THIS AFTERNOON. THE DISTURBANCE WILL ARRIVE IN SOUTHWEST NEBRASKA THIS EVENING...AND EXPECT A PERIOD...AROUND 4 HOURS OR SO...OF MVFR AND SNOW AS THE SYSTEM PASSES. EXPECT IMPROVING CONDITIONS AFTER ABOUT 07Z WEDNESDAY. WINDS ARE CURRENTLY GUSTING TO NEAR 35 KTS FROM THE NORTH...AND THESE WILL GRADUALLY DIMINISH THROUGH THE AFTERNOON...WITH SPEEDS GENERALLY 10 KTS OR LESS TONIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...POWER SHORT TERM...TAYLOR LONG TERM...POWER AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 AM CST TUE MAR 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 306 AM CST TUE MAR 3 2015 TODAY AND TONIGHT...THE RAP AND OTHER MODELS INDICATE THE SNOW BAND ACROSS NRN NEB WILL EXIT THIS FORECAST AREA THIS MORNING. SOME LIGHT SNOW WOULD LIKELY PERSIST INTO THE AFTN AS THE ARCTIC FRONT UNDERCUTS DEEP MOISTURE IN PLACE LEAVING A GROWTH ZONE FOR SNOW ABOVE 850 MB. THERE IS NO REAL CHANGE IN THE SNOWFALL FORECAST EXCEPT TO SAY THE MODELS CAME IN A BIT DRIER ACROSS THE NORTH BUT THIS MAY JUST BE A WOBBLE IN THE MODEL CONSENSUS. GIVEN THE ROBUST MOISTURE AND DECENT MID AND LOW LEVEL FRONTOGENESIS...1 TO 4 INCHES OF SNOW WOULD APPEAR LIKELY. THE MODEL CONSENSUS OF THE HRRR...RAP...MOSGUIDE AND NAMDNG SUGGESTS GUSTS TO 45 MPH BEHIND THE ARCTIC FRONT. THE BULK OF THE SNOWFALL WILL BE OCCURRING AHEAD OF THESE GUSTS. SO THE WINTER WEATHER ADVISORY APPEARS TO BE RIGHT ON TRACK. WIDESPREAD FOG HAS DEVELOPED AHEAD OF THE ARCTIC FRONT. SFC LOW PRESSURE IS CAUSING THE WINDS TO BACK WITH DRY AIR ALOFT PROMOTING FOG DEVELOPMENT. LIGHT FREEZING RAIN...FREEZING FOG AND FREEZING DRIZZLE SHOULD CONTINUE AHEAD OF THE ARCTIC FRONT. A CHECK ON THE HIGHWAY CAMS INDICATES THE ROAD SURFACES HAVE NOT YET CROSSED THE FREEZING MARK AND ONLY THE CHAPPELL CAMERA APPEARED TO BE COLLECTING ICE ON THE LENS. WEATHER CONDITIONS WILL BE MONITORED CLOSELY FOR SIGNS OF ICING WHICH WOULD WARRANT A FREEZING RAIN ADVISORY THIS MORNING AHEAD OF THE ARCTIC FRONT. ONCE THE ARCTIC FRONT CROSSES THE FCST AREA AROUND 15Z THE ICING THREAT SHOULD END. LOWS TONIGHT FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO. THE WARMER READINGS ACROSS THE SOUTH ARE THE RESULT OF CLOUD COVER AND LINGERING SNOW ACROSS THE FAR SOUTH. SKIES SHOULD CLEAR ACROSS THE NORTH AND WIND CHILL READING ACROSS SHERIDAN AND CHERRY COUNTIES WILL BE APPROACHING OR EXCEEDING THE MINUS 20 THRESHOLD FOR A WIND CHILL ADVISORY. LATER FORECASTS CAN REFINE THIS ELEMENT OF THE FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 306 AM CST TUE MAR 3 2015 TEMPERATURES ARE THE MAIN FORECAST CHALLENGE GOING IN THE EXTENDED PERIODS...AS ARCTIC HIGH PRESSURE WILL BE REPLACED BY DOWNSLOPING WARMING WESTERLY WIND ON THURSDAY. THUS...BELOW AVERAGE TEMPERATURES ARE FORECAST FOR WEDNESDAY...BUT THEREAFTER...CONDITIONS FAVOR NEAR OR ABOVE NORMAL TEMPERATURES. WEDNESDAY...ANOTHER COLD DAY ANTICIPATED AS ARCTIC HIGH PRESSURE REIGNS SUPREME. HIGHS IN THE TEENS AND 20S ARE FORECAST WITH APPARENT TEMPERATURES DANGEROUSLY COLD DURING THE MORNING HOURS. MOST LOCATIONS SHOULD SEE WIND CHILLS OF MINUS TEN OR COLDER UNTIL NOON. THEREAFTER...THE MEDIUM AND LONG RANGE MODELS ARE SHOWING GOOD AGREEMENT IN THAT A SHARP TROUGH...WHICH EXTENDS FROM EASTERN CANADA SOUTHWEST TO BAJA WILL SPLIT AND PROGRESS EAST THROUGH LATE WEEK. THIS WILL LEAVE A CUT OFF LOW SOUTH OF THE DESERT SOUTHWEST...BUT ALLOW THE EASTWARD EXPANSION OF AN AMPLIFIED UPPER RIDGE ACROSS THE WESTERN CONUS. AS THE UPPER LEVELS BECOME LESS AMPLIFIED OVER THE PLAINS...THE PATTERN WOULD THEN FAVOR A MORE DIRECT PATH FROM THE PACIFIC...RATHER THAN THE ARCTIC WHICH HAS BEEN OBSERVED LATELY. AT THE SURFACE...ARCTIC HIGH PRESSURE WILL BUILD EAST WITH THE ADVANCING TROUGH...LEAVING BEHIND A GREATER SOUTHWEST TO WESTERLY COMPONENT OF THE LOWER TROPOSPHERIC WIND. THE DOWNSLOPING TRAJECTORY WILL WORK IN CONCERT WITH RISING HEIGHTS AND THE ASSOCIATED WAA TO PROMOTE RISING TEMPERATURES THURSDAY AND FRIDAY. MOST LOCATIONS WILL SEE HIGHS IN THE 40S BY THURSDAY...WITH 50S ANTICIPATED FOR FRIDAY. THE MODELS ARE HIGHLIGHTING THE PASSAGE OF A WEAK SHORTWAVE AND COLD FRONT ON SATURDAY. THIS AIRMASS HAS A GREATER PACIFIC INFLUENCE...THUS TEMPERATURES ONLY ARE FORECAST TO COOL SLIGHTLY. IT SHOULD BE NOTED HOWEVER THAT THE GFS HAS CAME IN COOLER THAN PREVIOUS FORECASTS...WITH COOLER H85 TEMPERATURES NEARING MINUS 5 ACROSS MUCH OF THE FORECAST AREA EARLY SATURDAY AFTERNOON. WE MAY BE A BIT OPTIMISTIC ON THE CURRENT FORECAST HIGHS...WILL SEE IN THE COMING DAYS. OTHERWISE THE WAVE ARRIVES WILL LITTLE FANFARE...MOISTURE PROFILES IN THE TROPOSPHERE ARE RATHER LACKING...SO WILL CONTINUE THE DRY FORECAST. BEYOND SATURDAY...A DOWNSLOPING REGIME REIGNS ONCE AGAIN ALLOWING FOR ANOTHER WARMUP. THE MODELS ADVERTISE THE RIDGE AXIS BUILDING EAST TOWARD THE HIGH PLAINS EARLY NEXT WEEK...HIGHS SHOULD RESPOND BY WARMING INTO THE UPPER 50S...POSSIBLY LOWER 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1144 AM CST TUE MAR 3 2015 AN UPPER LEVEL DISTURBANCE CURRENTLY LOCATED NEAR KSLC...WILL MOVE EAST ACROSS SOUTHERN WY AND NORTHERN CO THIS AFTERNOON. THE DISTURBANCE WILL ARRIVE IN SOUTHWEST NEBRASKA THIS EVENING...AND EXPECT A PERIOD...AROUND 4 HOURS OR SO...OF MVFR AND SNOW AS THE SYSTEM PASSES. EXPECT IMPROVING CONDITIONS AFTER ABOUT 07Z WEDNESDAY. WINDS ARE CURRENTLY GUSTING TO NEAR 35 KTS FROM THE NORTH...AND THESE WILL GRADUALLY DIMINISH THROUGH THE AFTERNOON...WITH SPEEDS GENERALLY 10 KTS OR LESS TONIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ004>007-094. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...TAYLOR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
523 AM CST TUE MAR 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 306 AM CST TUE MAR 3 2015 TODAY AND TONIGHT...THE RAP AND OTHER MODELS INDICATE THE SNOW BAND ACROSS NRN NEB WILL EXIT THIS FORECAST AREA THIS MORNING. SOME LIGHT SNOW WOULD LIKELY PERSIST INTO THE AFTN AS THE ARCTIC FRONT UNDERCUTS DEEP MOISTURE IN PLACE LEAVING A GROWTH ZONE FOR SNOW ABOVE 850 MB. THERE IS NO REAL CHANGE IN THE SNOWFALL FORECAST EXCEPT TO SAY THE MODELS CAME IN A BIT DRIER ACROSS THE NORTH BUT THIS MAY JUST BE A WOBBLE IN THE MODEL CONSENSUS. GIVEN THE ROBUST MOISTURE AND DECENT MID AND LOW LEVEL FRONTOGENESIS...1 TO 4 INCHES OF SNOW WOULD APPEAR LIKELY. THE MODEL CONSENSUS OF THE HRRR...RAP...MOSGUIDE AND NAMDNG SUGGESTS GUSTS TO 45 MPH BEHIND THE ARCTIC FRONT. THE BULK OF THE SNOWFALL WILL BE OCCURRING AHEAD OF THESE GUSTS. SO THE WINTER WEATHER ADVISORY APPEARS TO BE RIGHT ON TRACK. WIDESPREAD FOG HAS DEVELOPED AHEAD OF THE ARCTIC FRONT. SFC LOW PRESSURE IS CAUSING THE WINDS TO BACK WITH DRY AIR ALOFT PROMOTING FOG DEVELOPMENT. LIGHT FREEZING RAIN...FREEZING FOG AND FREEZING DRIZZLE SHOULD CONTINUE AHEAD OF THE ARCTIC FRONT. A CHECK ON THE HIGHWAY CAMS INDICATES THE ROAD SURFACES HAVE NOT YET CROSSED THE FREEZING MARK AND ONLY THE CHAPPELL CAMERA APPEARED TO BE COLLECTING ICE ON THE LENS. WEATHER CONDITIONS WILL BE MONITORED CLOSELY FOR SIGNS OF ICING WHICH WOULD WARRANT A FREEZING RAIN ADVISORY THIS MORNING AHEAD OF THE ARCTIC FRONT. ONCE THE ARCTIC FRONT CROSSES THE FCST AREA AROUND 15Z THE ICING THREAT SHOULD END. LOWS TONIGHT FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO. THE WARMER READINGS ACROSS THE SOUTH ARE THE RESULT OF CLOUD COVER AND LINGERING SNOW ACROSS THE FAR SOUTH. SKIES SHOULD CLEAR ACROSS THE NORTH AND WIND CHILL READING ACROSS SHERIDAN AND CHERRY COUNTIES WILL BE APPROACHING OR EXCEEDING THE MINUS 20 THRESHOLD FOR A WIND CHILL ADVISORY. LATER FORECASTS CAN REFINE THIS ELEMENT OF THE FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 306 AM CST TUE MAR 3 2015 TEMPERATURES ARE THE MAIN FORECAST CHALLENGE GOING IN THE EXTENDED PERIODS...AS ARCTIC HIGH PRESSURE WILL BE REPLACED BY DOWNSLOPING WARMING WESTERLY WIND ON THURSDAY. THUS...BELOW AVERAGE TEMPERATURES ARE FORECAST FOR WEDNESDAY...BUT THEREAFTER...CONDITIONS FAVOR NEAR OR ABOVE NORMAL TEMPERATURES. WEDNESDAY...ANOTHER COLD DAY ANTICIPATED AS ARCTIC HIGH PRESSURE REIGNS SUPREME. HIGHS IN THE TEENS AND 20S ARE FORECAST WITH APPARENT TEMPERATURES DANGEROUSLY COLD DURING THE MORNING HOURS. MOST LOCATIONS SHOULD SEE WIND CHILLS OF MINUS TEN OR COLDER UNTIL NOON. THEREAFTER...THE MEDIUM AND LONG RANGE MODELS ARE SHOWING GOOD AGREEMENT IN THAT A SHARP TROUGH...WHICH EXTENDS FROM EASTERN CANADA SOUTHWEST TO BAJA WILL SPLIT AND PROGRESS EAST THROUGH LATE WEEK. THIS WILL LEAVE A CUT OFF LOW SOUTH OF THE DESERT SOUTHWEST...BUT ALLOW THE EASTWARD EXPANSION OF AN AMPLIFIED UPPER RIDGE ACROSS THE WESTERN CONUS. AS THE UPPER LEVELS BECOME LESS AMPLIFIED OVER THE PLAINS...THE PATTERN WOULD THEN FAVOR A MORE DIRECT PATH FROM THE PACIFIC...RATHER THAN THE ARCTIC WHICH HAS BEEN OBSERVED LATELY. AT THE SURFACE...ARCTIC HIGH PRESSURE WILL BUILD EAST WITH THE ADVANCING TROUGH...LEAVING BEHIND A GREATER SOUTHWEST TO WESTERLY COMPONENT OF THE LOWER TROPOSPHERIC WIND. THE DOWNSLOPING TRAJECTORY WILL WORK IN CONCERT WITH RISING HEIGHTS AND THE ASSOCIATED WAA TO PROMOTE RISING TEMPERATURES THURSDAY AND FRIDAY. MOST LOCATIONS WILL SEE HIGHS IN THE 40S BY THURSDAY...WITH 50S ANTICIPATED FOR FRIDAY. THE MODELS ARE HIGHLIGHTING THE PASSAGE OF A WEAK SHORTWAVE AND COLD FRONT ON SATURDAY. THIS AIRMASS HAS A GREATER PACIFIC INFLUENCE...THUS TEMPERATURES ONLY ARE FORECAST TO COOL SLIGHTLY. IT SHOULD BE NOTED HOWEVER THAT THE GFS HAS CAME IN COOLER THAN PREVIOUS FORECASTS...WITH COOLER H85 TEMPERATURES NEARING MINUS 5 ACROSS MUCH OF THE FORECAST AREA EARLY SATURDAY AFTERNOON. WE MAY BE A BIT OPTIMISTIC ON THE CURRENT FORECAST HIGHS...WILL SEE IN THE COMING DAYS. OTHERWISE THE WAVE ARRIVES WILL LITTLE FANFARE...MOISTURE PROFILES IN THE TROPOSPHERE ARE RATHER LACKING...SO WILL CONTINUE THE DRY FORECAST. BEYOND SATURDAY...A DOWNSLOPING REGIME REIGNS ONCE AGAIN ALLOWING FOR ANOTHER WARMUP. THE MODELS ADVERTISE THE RIDGE AXIS BUILDING EAST TOWARD THE HIGH PLAINS EARLY NEXT WEEK...HIGHS SHOULD RESPOND BY WARMING INTO THE UPPER 50S...POSSIBLY LOWER 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 523 AM CST TUE MAR 3 2015 IFR/LOCAL LIFR IN SNOW...BLOWING SNOW AND FOG CONTINUE UNTIL AROUND 15Z THIS MORNING AND THEN IMPROVE TO MVFR 15Z-18Z. VFR/MVFR IN LOW CLOUDS ARE EXPECTED FROM 18Z ONWARD. NORTH WINDS INCREASE TO 34025G40KT THIS MORNING AND DECREASE DURING THE AFTN. MVFR/IFR IN SNOW AND LOW CIGS MAY DEVELOP TONIGHT ALONG AND SOUTH OF INTERSTATE 80. LOWEST FLIGHT CONDITIONS ARE EXPECTED SOUTH TOWARD THE KANSAS BORDER WHERE SNOW IS MORE LIKELY. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ004>007-094. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
306 AM CST TUE MAR 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 306 AM CST TUE MAR 3 2015 TODAY AND TONIGHT...THE RAP AND OTHER MODELS INDICATE THE SNOW BAND ACROSS NRN NEB WILL EXIT THIS FORECAST AREA THIS MORNING. SOME LIGHT SNOW WOULD LIKELY PERSIST INTO THE AFTN AS THE ARCTIC FRONT UNDERCUTS DEEP MOISTURE IN PLACE LEAVING A GROWTH ZONE FOR SNOW ABOVE 850 MB. THERE IS NO REAL CHANGE IN THE SNOWFALL FORECAST EXCEPT TO SAY THE MODELS CAME IN A BIT DRIER ACROSS THE NORTH BUT THIS MAY JUST BE A WOBBLE IN THE MODEL CONSENSUS. GIVEN THE ROBUST MOISTURE AND DECENT MID AND LOW LEVEL FRONTOGENESIS...1 TO 4 INCHES OF SNOW WOULD APPEAR LIKELY. THE MODEL CONSENSUS OF THE HRRR...RAP...MOSGUIDE AND NAMDNG SUGGESTS GUSTS TO 45 MPH BEHIND THE ARCTIC FRONT. THE BULK OF THE SNOWFALL WILL BE OCCURRING AHEAD OF THESE GUSTS. SO THE WINTER WEATHER ADVISORY APPEARS TO BE RIGHT ON TRACK. WIDESPREAD FOG HAS DEVELOPED AHEAD OF THE ARCTIC FRONT. SFC LOW PRESSURE IS CAUSING THE WINDS TO BACK WITH DRY AIR ALOFT PROMOTING FOG DEVELOPMENT. LIGHT FREEZING RAIN...FREEZING FOG AND FREEZING DRIZZLE SHOULD CONTINUE AHEAD OF THE ARCTIC FRONT. A CHECK ON THE HIGHWAY CAMS INDICATES THE ROAD SURFACES HAVE NOT YET CROSSED THE FREEZING MARK AND ONLY THE CHAPPELL CAMERA APPEARED TO BE COLLECTING ICE ON THE LENS. WEATHER CONDITIONS WILL BE MONITORED CLOSELY FOR SIGNS OF ICING WHICH WOULD WARRANT A FREEZING RAIN ADVISORY THIS MORNING AHEAD OF THE ARCTIC FRONT. ONCE THE ARCTIC FRONT CROSSES THE FCST AREA AROUND 15Z THE ICING THREAT SHOULD END. LOWS TONIGHT FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO. THE WARMER READINGS ACROSS THE SOUTH ARE THE RESULT OF CLOUD COVER AND LINGERING SNOW ACROSS THE FAR SOUTH. SKIES SHOULD CLEAR ACROSS THE NORTH AND WIND CHILL READING ACROSS SHERIDAN AND CHERRY COUNTIES WILL BE APPROACHING OR EXCEEDING THE MINUS 20 THRESHOLD FOR A WIND CHILL ADVISORY. LATER FORECASTS CAN REFINE THIS ELEMENT OF THE FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 306 AM CST TUE MAR 3 2015 TEMPERATURES ARE THE MAIN FORECAST CHALLENGE GOING IN THE EXTENDED PERIODS...AS ARCTIC HIGH PRESSURE WILL BE REPLACED BY DOWNSLOPING WARMING WESTERLY WIND ON THURSDAY. THUS...BELOW AVERAGE TEMPERATURES ARE FORECAST FOR WEDNESDAY...BUT THEREAFTER...CONDITIONS FAVOR NEAR OR ABOVE NORMAL TEMPERATURES. WEDNESDAY...ANOTHER COLD DAY ANTICIPATED AS ARCTIC HIGH PRESSURE REIGNS SUPREME. HIGHS IN THE TEENS AND 20S ARE FORECAST WITH APPARENT TEMPERATURES DANGEROUSLY COLD DURING THE MORNING HOURS. MOST LOCATIONS SHOULD SEE WIND CHILLS OF MINUS TEN OR COLDER UNTIL NOON. THEREAFTER...THE MEDIUM AND LONG RANGE MODELS ARE SHOWING GOOD AGREEMENT IN THAT A SHARP TROUGH...WHICH EXTENDS FROM EASTERN CANADA SOUTHWEST TO BAJA WILL SPLIT AND PROGRESS EAST THROUGH LATE WEEK. THIS WILL LEAVE A CUT OFF LOW SOUTH OF THE DESERT SOUTHWEST...BUT ALLOW THE EASTWARD EXPANSION OF AN AMPLIFIED UPPER RIDGE ACROSS THE WESTERN CONUS. AS THE UPPER LEVELS BECOME LESS AMPLIFIED OVER THE PLAINS...THE PATTERN WOULD THEN FAVOR A MORE DIRECT PATH FROM THE PACIFIC...RATHER THAN THE ARCTIC WHICH HAS BEEN OBSERVED LATELY. AT THE SURFACE...ARCTIC HIGH PRESSURE WILL BUILD EAST WITH THE ADVANCING TROUGH...LEAVING BEHIND A GREATER SOUTHWEST TO WESTERLY COMPONENT OF THE LOWER TROPOSPHERIC WIND. THE DOWNSLOPING TRAJECTORY WILL WORK IN CONCERT WITH RISING HEIGHTS AND THE ASSOCIATED WAA TO PROMOTE RISING TEMPERATURES THURSDAY AND FRIDAY. MOST LOCATIONS WILL SEE HIGHS IN THE 40S BY THURSDAY...WITH 50S ANTICIPATED FOR FRIDAY. THE MODELS ARE HIGHLIGHTING THE PASSAGE OF A WEAK SHORTWAVE AND COLD FRONT ON SATURDAY. THIS AIRMASS HAS A GREATER PACIFIC INFLUENCE...THUS TEMPERATURES ONLY ARE FORECAST TO COOL SLIGHTLY. IT SHOULD BE NOTED HOWEVER THAT THE GFS HAS CAME IN COOLER THAN PREVIOUS FORECASTS...WITH COOLER H85 TEMPERATURES NEARING MINUS 5 ACROSS MUCH OF THE FORECAST AREA EARLY SATURDAY AFTERNOON. WE MAY BE A BIT OPTIMISTIC ON THE CURRENT FORECAST HIGHS...WILL SEE IN THE COMING DAYS. OTHERWISE THE WAVE ARRIVES WILL LITTLE FANFARE...MOISTURE PROFILES IN THE TROPOSPHERE ARE RATHER LACKING...SO WILL CONTINUE THE DRY FORECAST. BEYOND SATURDAY...A DOWNSLOPING REGIME REIGNS ONCE AGAIN ALLOWING FOR ANOTHER WARMUP. THE MODELS ADVERTISE THE RIDGE AXIS BUILDING EAST TOWARD THE HIGH PLAINS EARLY NEXT WEEK...HIGHS SHOULD RESPOND BY WARMING INTO THE UPPER 50S...POSSIBLY LOWER 60S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1130 PM CST MON MAR 2 2015 A FRONT ACROSS WESTERN SOUTH DAKOTA AND NORTHWEST NEBRASKA IS EXPECTED TO MOVE ACROSS THE STATE TONIGHT. RADAR-INDICATED PRECIPITATION IN WESTERN NEBRASKA AND SOUTHEAST WYOMING WILL SPREAD ACROSS NORTHERN NEBRASKA AS THE FRONT MAKEST ITS WAY SOUTHEASTWARD THROUGH WESTERN AND THEN CENTRAL NEBRASKA. FORECAST SOUNDINGS INDICATE THAT THE VERTICAL TEMPERATURE PROFILES WOULD FAVOR SNOW MOST AREAS. IT IS POSSIBLE THAT...IN SOUTHWEST NEBRASKA...THERE COULD BE SOME FREEZING DRIZZLE OR LIGHT FREEZING RAIN. WIND WILL BE 180-210 AT 15-20G23-29KT UNTIL SOMETIME AFTER 06Z. WIND WILL SHIFT TO 330-360 AT 15-25G30-36KT BEGINNING IN THE NORTH AROUND 10Z AND THE REST OF WESTERN NEBRASKA BEGINNING 14Z. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ004>007-094. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
655 PM EST WED MAR 4 2015 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE NORTH COUNTRY OVERNIGHT. A RETURN TO BELOW-NORMAL TEMPERATURES IS EXPECTED TO CLOSE THE WEEK...WITH SUB-ZERO LOW TEMPERATURES EXPECTED THURSDAY NIGHT. A COUPLE OF CLIPPER SYSTEMS WILL MOVE ACROSS THE NORTH COUNTRY OVER THE WEEKEND...THOUGH PRECIPITATION FROM EACH WILL BE LIMITED. TEMPERATURES MODERATE TOWARD MORE SEASONAL NORMALS FOR THE WEEKEND INTO NEXT WEEK. && .NEAR TERM /UNTIL 7 AM THURSDAY MORNING/... AS OF 655 PM EST WEDNESDAY...CURRENT FORECAST IN GOOD SHAPE...SO NO CHANGES HAVE BEEN MADE. PREVIOUS DISCUSSION FROM 311 PM EST WEDNESDAY...MOSTLY CLOUDY SKIES WITH MORE SEASONAL TEMPERATURES IN THE 30S TO NEAR 40 IN PLACE THIS AFTERNOON. SKY COVER CONDITIONS WILL BE THE TOUGHEST ASPECT OF TONIGHT`S FORECAST. GUIDANCE HAS STRUGGLED WITH THE DEGREE OF CLOUD COVER TODAY, CLEARING THE NORTH COUNTRY WAY TOO QUICK THAN WHAT`S HAPPENING IN REALITY. FEEL THAT WITH CONTINUED WESTERLY LOW- LEVEL FLOW ALLOWING FOR MOISTURE TO STREAM IN FROM THE GREAT LAKES, MOSTLY CLOUDY SKIES WILL CONTINUE WELL INTO THE EVENING UNTIL LOW- LEVEL FLOW TURNS MORE WEST-NORTHWEST/DRIER BEHIND A PASSING COLD FRONT. I`VE OFFERED PARTLY TO MOSTLY CLOUDY SKIES BASED ON A BLEND OF RECENT RAP AND 12Z NAM RH. MODERATELY STRONG COLD AIR ADVECTION IN THE FRONT`S WAKE WILL ALLOW FOR 925 MB TEMPS TO FALL INTO THE -12 TO -15C RANGE. LOW TEMPERATURES TONIGHT ARE A FEW DEGREES WARMER THAN AVAILABLE MAV/MET MOS GIVEN DEGREE OF CLOUDS AND NORTHERLY WINDS AROUND 10 KNOTS. VALUES RUN FROM THE SINGLE DIGITS IN THE TYPICALLY COLDER NORTHEAST KINGDOM AND ADIRONDACKS AREAS, WITH MID-TEENS FOR THE CHAMPLAIN VALLEY INTO SOUTHERN VERMONT. ANY MELTED SNOW OR SLUSH DURING THE DAY STANDS THE POTENTIAL TO RE-FREEZE OVERNIGHT, LEADING TO SLIPPERY SPOTS ON ROADWAYS AND SIDEWALKS. && .SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 311 PM EST WEDNESDAY... ALL-IN-ALL, IT`S A FAIRLY QUIET PERIOD OF WEATHER FOR THE REST OF THE WORKWEEK WITH A RETURN TO BELOW-NORMAL TEMPERATURES FOR EARLY MARCH. FOR THURSDAY: RIDGE OF HIGH PRESSURE BUILDS ACROSS THE NORTH COUNTRY WITH MODERATELY STRONG COLD AIR ADVECTION GENERALLY WEAKENING INTO THE AFTERNOON. SKY COVER WILL INITIALLY TEND TO BE GREATEST IN CENTRAL AND SOUTHERN VERMONT INTO THE ADIRONDACKS AS MID- TO HIGH- LEVEL MOISTURE ADVECTS OVER A MORE ACTIVE BAROCLINIC ZONE TO THE SOUTH. GREATER CLEARING EXPECTED INTO THE AFTERNOON. LOOKING AT HIGHS IN THE TEENS TO THE LOW 20S. FOR THURSDAY NIGHT: CLEAR, CALM (OR VERY LIGHT WINDS), AND COLD. IDEAL RADIATIONAL COOLING UNDER RIDGE OF HIGH PRESSURE WITH 925 MB TEMPS OF -17 TO -19C SHOULD ALLOW FOR SUB-ZERO LOWS AREAWIDE, WITH THE COLDEST READINGS IN THE NORTHEAST KINGDOM (NEAR 20 BELOW). FOR FRIDAY: AFTER A COLD START, TEMPERATURES BEGIN TO MODERATE A BIT AS RIDGE AXIS SHIFTS A BIT TO THE SOUTH INTO SOUTHERN NEW ENGLAND. INCREASING SOUTHWEST FLOW INTO THE DAY ON FRIDAY AHEAD OF A CLIPPER- TYPE SYSTEM. EXPECT HIGH CLOUDS TO GRADUALLY LOWER AND THICKEN ESPECIALLY AS WE MOVE INTO FRIDAY EVENING. THOUGH HIGHS WILL TOP OUT IN THE UPPER TEENS TO MID 20S, IT PROBABLY WON`T FEEL THAT WAY GIVEN SOUTHWEST WINDS IN THE 10 TO 15 MPH RANGE. FOR FRIDAY NIGHT: CLOUDS INCREASE INTO THE EVENING AS CLIPPER SYSTEM APPROACHES FROM ONTARIO. THERE`S SOME DIFFERENCE IN TIMING BETWEEN THE GLOBAL MODELS, WITH THE 12Z/04TH ECMWF BEING ABOUT 6 HOURS SLOWER THAN THE GFS. THE NAM AND SREF MEAN ALSO LEND SUPPORT TO THE FASTER GFS. FOLLOWING THAT NAM/SREF MEAN/GFS MAJORITY, I`VE OPTED TO SHOW SLIGHT CHANCE OF SNOW SHOWERS FOR ST. LAWRENCE COUNTY AND THE ADIRONDACKS FOR THE AFTER MIDNIGHT PERIOD FRIDAY NIGHT. SNOW ACCUMS TO AN INCH OR LESS THROUGH 12Z SATURDAY AS MOISTURE SOURCES ARE LIMITED TO THE GREAT LAKES. LOWS IN THE TEENS LOOK TO OCCUR EARLY IN THE EVENING BEFORE LEVELING OFF TOWARD MORNING UNDER CLOUD COVER AND SOUTHWEST FLOW. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 355 PM EST WEDNESDAY...OVERALL TREND DURING THE EXTENDED PERIOD WILL BE TOWARDS MORE SEASONAL TEMPERATURES AND SEVERAL CHANCES FOR LIGHT PRECIPITATION AS THE UPPER FLOW GOES MORE ZONAL AND A FEW WEAK SYSTEMS MOVE THROUGH THE NORTHEAST. MOST NOTABLE SYSTEM WILL BE A WEAK CLIPPER RIDING ALONG A STALLED FRONTAL BOUNDARY THIS WEEKEND. MEDIUM RANGE GUIDANCE OF THE GFS AND ECMWF DIFFER WITH THE TIMING OF SHORTWAVE ENERGY MOVING INTO THE AREA ALONG WITH THE DEVELOPMENT OF THE LOW, SO HAVE KEPT POPS IN THE CHANCE CATEGORY FOR THE WEEKEND. IN GENERAL THOUGH, LOOKS TO BE A LIGHT QPF EVENT WITH TEMP PROFILES SUPPORTING SNOW WITH HIGHS IN THE UPPER 20S TO LOWER 30S AND LOWS IN THE TEENS. GOING INTO NEXT WEEK CONDITIONS TREND DRY AS HIGH PRESSURE DRIFTS FROM THE TENNESSEE RIVER VALLEY MONDAY OFF THE EASTERN SEABOARD TUESDAY AND WEDNESDAY. UPPER FLOW REMAINS ZONAL SO NOT EXPECTING COMPLETELY CLEAR SKIES BUT TEMPERATURES WILL MODERATE UNDER PARTLY CLEAR AND DRY CONDITIONS WITH HIGHS IN THE 30S MONDAY, AND UP INTO THE 40S FOR TUESDAY AND WEDNESDAY. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...MAINLY VFR CONDITIONS THIS EVENING AS HIGH PRESSURE BUILDS INTO THE REGION. LOTS OF LOW LEVEL MOISTURE AROUND BELOW INCOMING DRY AIR ALOFT SO THINK SCT-BKN VFR DECK HANGS AROUND UNTIL THE DRIER AIR ALOFT WINS OUT TOWARDS 12Z THURSDAY. THE LONE EXCEPTION TO THAT WILL BE IN SLK AND MPV WERE THE LOW LEVEL MOISTURE COULD DROP CEILINGS TO MVFR FOR A SMALL WINDOW BETWEEN 08-14Z. AFTER 14Z...THE LOW TO MID LEVEL CLOUDS WILL CLEAR OUT LEAVING ONLY SOME HIGH LEVEL CIRRUS CLOUDS UNDER VFR CONDITIONS. LIGHT TO MODERATE WESTERLY TO SOUTHWESTERLY WINDS 08-14 KTS WILL CONTINUE OVERNIGHT. BOTH SLK AND MSS WILL LIKELY GUSTY WINDS THROUGH THE EARLY EVENING BEFORE SUBSIDING AFTER 06Z. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THURSDAY THROUGH 06Z SATURDAY...GENERALLY VFR UNDER INCOMING HIGH PRESSURE. 06Z SATURDAY - 00Z TUESDAY...PERIODS OF MVFR/IFR IN LIGHT SNOW AS SEVERAL SYSTEM TRACK THROUGH THE REGION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...LOCONTO NEAR TERM...WGH/LOCONTO SHORT TERM...LOCONTO LONG TERM...LAHIFF AVIATION...DEAL/LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
650 PM EST WED MAR 4 2015 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE NORTH COUNTRY TONIGHT. A RETURN TO BELOW-NORMAL TEMPERATURES IS EXPECTED TO CLOSE THE WORKWEEK...WITH SUB-ZERO LOW TEMPERATURES EXPECTED THURSDAY NIGHT. A COUPLE OF CLIPPER SYSTEMS WILL MOVE ACROSS THE NORTH COUNTRY OVER THE WEEKEND...THOUGH PRECIPITATION FROM EACH WILL BE LIMITED. TEMPERATURES MODERATE TOWARD MORE SEASONAL NORMALS FOR THE WEEKEND INTO NEXT WEEK. && .NEAR TERM /UNTIL 7 AM THURSDAY MORNING/... AS OF 311 PM EST WEDNESDAY...MOSTLY CLOUDY SKIES WITH MORE SEASONAL TEMPERATURES IN THE 30S TO NEAR 40 IN PLACE THIS AFTERNOON. SKY COVER CONDITIONS WILL BE THE TOUGHEST ASPECT OF TONIGHT`S FORECAST. GUIDANCE HAS STRUGGLED WITH THE DEGREE OF CLOUD COVER TODAY, CLEARING THE NORTH COUNTRY WAY TOO QUICK THAN WHAT`S HAPPENING IN REALITY. FEEL THAT WITH CONTINUED WESTERLY LOW- LEVEL FLOW ALLOWING FOR MOISTURE TO STREAM IN FROM THE GREAT LAKES, MOSTLY CLOUDY SKIES WILL CONTINUE WELL INTO THE EVENING UNTIL LOW- LEVEL FLOW TURNS MORE WEST-NORTHWEST/DRIER BEHIND A PASSING COLD FRONT. I`VE OFFERED PARTLY TO MOSTLY CLOUDY SKIES BASED ON A BLEND OF RECENT RAP AND 12Z NAM RH. MODERATELY STRONG COLD AIR ADVECTION IN THE FRONT`S WAKE WILL ALLOW FOR 925 MB TEMPS TO FALL INTO THE -12 TO -15C RANGE. LOW TEMPERATURES TONIGHT ARE A FEW DEGREES WARMER THAN AVAILABLE MAV/MET MOS GIVEN DEGREE OF CLOUDS AND NORTHERLY WINDS AROUND 10 KNOTS. VALUES RUN FROM THE SINGLE DIGITS IN THE TYPICALLY COLDER NORTHEAST KINGDOM AND ADIRONDACKS AREAS, WITH MID-TEENS FOR THE CHAMPLAIN VALLEY INTO SOUTHERN VERMONT. ANY MELTED SNOW OR SLUSH DURING THE DAY STANDS THE POTENTIAL TO RE-FREEZE OVERNIGHT, LEADING TO SLIPPERY SPOTS ON ROADWAYS AND SIDEWALKS. && .SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 311 PM EST WEDNESDAY... ALL-IN-ALL, IT`S A FAIRLY QUIET PERIOD OF WEATHER FOR THE REST OF THE WORKWEEK WITH A RETURN TO BELOW-NORMAL TEMPERATURES FOR EARLY MARCH. FOR THURSDAY: RIDGE OF HIGH PRESSURE BUILDS ACROSS THE NORTH COUNTRY WITH MODERATELY STRONG COLD AIR ADVECTION GENERALLY WEAKENING INTO THE AFTERNOON. SKY COVER WILL INITIALLY TEND TO BE GREATEST IN CENTRAL AND SOUTHERN VERMONT INTO THE ADIRONDACKS AS MID- TO HIGH- LEVEL MOISTURE ADVECTS OVER A MORE ACTIVE BAROCLINIC ZONE TO THE SOUTH. GREATER CLEARING EXPECTED INTO THE AFTERNOON. LOOKING AT HIGHS IN THE TEENS TO THE LOW 20S. FOR THURSDAY NIGHT: CLEAR, CALM (OR VERY LIGHT WINDS), AND COLD. IDEAL RADIATIONAL COOLING UNDER RIDGE OF HIGH PRESSURE WITH 925 MB TEMPS OF -17 TO -19C SHOULD ALLOW FOR SUB-ZERO LOWS AREAWIDE, WITH THE COLDEST READINGS IN THE NORTHEAST KINGDOM (NEAR 20 BELOW). FOR FRIDAY: AFTER A COLD START, TEMPERATURES BEGIN TO MODERATE A BIT AS RIDGE AXIS SHIFTS A BIT TO THE SOUTH INTO SOUTHERN NEW ENGLAND. INCREASING SOUTHWEST FLOW INTO THE DAY ON FRIDAY AHEAD OF A CLIPPER- TYPE SYSTEM. EXPECT HIGH CLOUDS TO GRADUALLY LOWER AND THICKEN ESPECIALLY AS WE MOVE INTO FRIDAY EVENING. THOUGH HIGHS WILL TOP OUT IN THE UPPER TEENS TO MID 20S, IT PROBABLY WON`T FEEL THAT WAY GIVEN SOUTHWEST WINDS IN THE 10 TO 15 MPH RANGE. FOR FRIDAY NIGHT: CLOUDS INCREASE INTO THE EVENING AS CLIPPER SYSTEM APPROACHES FROM ONTARIO. THERE`S SOME DIFFERENCE IN TIMING BETWEEN THE GLOBAL MODELS, WITH THE 12Z/04TH ECMWF BEING ABOUT 6 HOURS SLOWER THAN THE GFS. THE NAM AND SREF MEAN ALSO LEND SUPPORT TO THE FASTER GFS. FOLLOWING THAT NAM/SREF MEAN/GFS MAJORITY, I`VE OPTED TO SHOW SLIGHT CHANCE OF SNOW SHOWERS FOR ST. LAWRENCE COUNTY AND THE ADIRONDACKS FOR THE AFTER MIDNIGHT PERIOD FRIDAY NIGHT. SNOW ACCUMS TO AN INCH OR LESS THROUGH 12Z SATURDAY AS MOISTURE SOURCES ARE LIMITED TO THE GREAT LAKES. LOWS IN THE TEENS LOOK TO OCCUR EARLY IN THE EVENING BEFORE LEVELING OFF TOWARD MORNING UNDER CLOUD COVER AND SOUTHWEST FLOW. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 355 PM EST WEDNESDAY...OVERALL TREND DURING THE EXTENDED PERIOD WILL BE TOWARDS MORE SEASONAL TEMPERATURES AND SEVERAL CHANCES FOR LIGHT PRECIPITATION AS THE UPPER FLOW GOES MORE ZONAL AND A FEW WEAK SYSTEMS MOVE THROUGH THE NORTHEAST. MOST NOTABLE SYSTEM WILL BE A WEAK CLIPPER RIDING ALONG A STALLED FRONTAL BOUNDARY THIS WEEKEND. MEDIUM RANGE GUIDANCE OF THE GFS AND ECMWF DIFFER WITH THE TIMING OF SHORTWAVE ENERGY MOVING INTO THE AREA ALONG WITH THE DEVELOPMENT OF THE LOW, SO HAVE KEPT POPS IN THE CHANCE CATEGORY FOR THE WEEKEND. IN GENERAL THOUGH, LOOKS TO BE A LIGHT QPF EVENT WITH TEMP PROFILES SUPPORTING SNOW WITH HIGHS IN THE UPPER 20S TO LOWER 30S AND LOWS IN THE TEENS. GOING INTO NEXT WEEK CONDITIONS TREND DRY AS HIGH PRESSURE DRIFTS FROM THE TENNESSEE RIVER VALLEY MONDAY OFF THE EASTERN SEABOARD TUESDAY AND WEDNESDAY. UPPER FLOW REMAINS ZONAL SO NOT EXPECTING COMPLETELY CLEAR SKIES BUT TEMPERATURES WILL MODERATE UNDER PARTLY CLEAR AND DRY CONDITIONS WITH HIGHS IN THE 30S MONDAY, AND UP INTO THE 40S FOR TUESDAY AND WEDNESDAY. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...MAINLY VFR CONDITIONS THIS EVENING AS HIGH PRESSURE BUILDS INTO THE REGION. LOTS OF LOW LEVEL MOISTURE AROUND BELOW INCOMING DRY AIR ALOFT SO THINK SCT-BKN VFR DECK HANGS AROUND UNTIL THE DRIER AIR ALOFT WINS OUT TOWARDS 12Z THURSDAY. THE LONE EXCEPTION TO THAT WILL BE IN SLK AND MPV WERE THE LOW LEVEL MOISTURE COULD DROP CEILINGS TO MVFR FOR A SMALL WINDOW BETWEEN 08-14Z. AFTER 14Z...THE LOW TO MID LEVEL CLOUDS WILL CLEAR OUT LEAVING ONLY SOME HIGH LEVEL CIRRUS CLOUDS UNDER VFR CONDITIONS. LIGHT TO MODERATE WESTERLY TO SOUTHWESTERLY WINDS 08-14 KTS WILL CONTINUE OVERNIGHT. BOTH SLK AND MSS WILL LIKELY GUSTY WINDS THROUGH THE EARLY EVENING BEFORE SUBSIDING AFTER 06Z. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THURSDAY THROUGH 06Z SATURDAY...GENERALLY VFR UNDER INCOMING HIGH PRESSURE. 06Z SATURDAY - 00Z TUESDAY...PERIODS OF MVFR/IFR IN LIGHT SNOW AS SEVERAL SYSTEM TRACK THROUGH THE REGION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...LOCONTO NEAR TERM...LOCONTO SHORT TERM...LOCONTO LONG TERM...LAHIFF AVIATION...DEAL/LAHIFF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
400 AM EST TUE MAR 3 2015 .SYNOPSIS...HIGH PRESSURE WILL WILL SHIFT OFFSHORE DURING THE DAY AS A LOW PRESSURE SYSTEM TRACKS NORTHEAST FROM THE CENTRAL PLAINS INTO THE GREAT LAKES LATER TODAY AND TONIGHT. A WARM FRONT WILL MOVE NORTH THROUGH THE REGION WEDNESDAY. && .NEAR TERM /TONIGHT THROUGH TUESDAY NIGHT/... AS OF 1000 PM MONDAY... AFTER A PLEASANTLY WARM DAY...COOLER AND DRIER AIR IS WORKING ITS WAY INTO THE AREA FROM THE NORTH-NORTHEAST AS A 1034MB SURFACE HIGH TRANSLATES EAST ACROSS THE MID-ATLANTIC STATES. THE PRIMARY COLD FRONT IS TO OUR SOUTH...BUT THERE APPEARS TO BE A SECONDARY BOUNDARY...WITH NOTICEABLY HIGH DEWPOINTS POOLING ALONG IT...MOVING FROM THE COASTAL PLAIN TOWARD THE PIEDMONT. THIS COMPLICATES THE OVERNIGHT FORECAST AS THE DRIER...SUB-20F DEWPOINT AIR OVER THE THE NORTHWEST PIEDMONT TRIES TO PUSH SOUTH BUT MAY ULTIMATELY BE HALTED OR SHUNTED OFF TO THE WEST. MOST MODEL ARENT HANDLING THIS VERY WELL...EVIDENT IN PART BY THE MUCH DRIER THAN FORECAST BOUNDARY LAYER ON THE 00Z KGSO RAOB...SO WILL LEAN ON THE RAP/HRRR WHICH HAS DEWPOINTS MOSTLY IN THE 20S TO LOWER 30S TUESDAY MORNING. TEMPS WILL CONTINUE TO FALL INTO THE 30S OVERNIGHT...BUT AS SOME 290K ISENTROPIC LIFT AND HIGHER BASED STRATUS SPREAD NORTH AND EAST ACROSS THE AREA...TEMPS SHOULD STABILIZE MOSTLY ABOVE FREEZING. THE BIGGEST FORECAST ISSUES TONIGHT WILL STILL BE 1) WHETHER OR NOT ANY LIGHT RAIN/DRIZZLE SPREADS FAR ENOUGH NORTH AND EAST INTO THE SUB-FREEZING AIRMASS BEFORE A WEAK DIURNAL RECOVERY IN TEMPS BEGINS ON TUESDAY MORNING...OR 2) PRECIP IS EVEN HEAVY ENOUGH WETBULB TEMPS BELOW FREEZING IN AREAS WHERE THEY ARE INITIALLY ABOVE FREEZING. 18Z AND 00Z GUIDANCE CONTINUES TO ONLY SHOW A COUPLE HUNDREDTHS AT BEST AND MOSTLY COMING AFTER 12Z. THE RAP AND HRRR ARE COMPLETELY DRY THROUGH 12Z. WILL LOWER POPS A LITTLE AND JUST MAINTAIN A MENTION JUST FREEZING DRIZZLE IN THE SMALL AREA WHERE TEMPS AT AT OR BELOW 32...WHICH IS CONFINED TO JUST THE NORTH PIEDMONT PRIOR TO 15Z. NO ADVISORY FOR FREEZING RAIN IS NEEDED AT THIS TIME. TEMPS ON TUESDAY WILL MOVE LITTLE OFF MORNING LOWS...MID 30S TO LOWER 40S. A WARM FRONT IS EXPECTED TO LIFT NORTHWARD TOWARD CENTRAL NC TUE NIGHT...WITH TEMPERATURES RISING OVERNIGHT ACROSS MUCH OF THE AREA...ALTHOUGH THEY COULD REMAIN NEAR STEADY IN THE N/NW PIEDMONT. LIGHT RAIN/DRIZZLE COULD TAPER AS THE WARM FRONT LIFTS WITH EXPANDING FOG CONDITIONS POSSIBLE. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 PM MONDAY... THE FORECAST PROBLEM FOR THIS PART OF THE FORECAST CONTINUES TO BE THE UNCERTAINTY IN TEMPERATURES DUE TO THE POTENTIALLY LINGERING WEDGE AND THE TIMING AND EXTENT TO WHICH THE WARM FRONT RETREATS NORTHWARD. GIVEN THAT THE MODELS HAVE A TENDENCY TO ERODE THE WEDGE TOO QUICKLY...ESPECIALLY IF THERE IS PRECIPITATION FALLING INTO IT...CURRENTLY FORECAST THE WEDGE STICKING AROUND INTO WEDNESDAY AFTERNOON IN THE FAR NW PIEDMONT...WITH A LARGE SPREAD IN TEMPS FROM NW TO SE ACROSS THE AREA. CONFIDENCE REMAINS SOMEWHAT LOW WITH RESPECT TO TEMPS...AS ANY CHANGES TO THE TIMING AND POSITION OF THE WEDGE/WARM FRONT AS THEY ERODE/RETREAT NORTHWARD WILL HIGHLY IMPACT TEMPERATURES. THEY WILL HOWEVER INCREASE GRADUALLY THROUGH AROUND MIDNIGHT THURSDAY BEFORE THE COLD FRONT BEGINS MOVING INTO THE NW. KEEPING IN MIND THE POTENTIAL MARGIN FOR ERRORS...FORECAST HIGH TEMPS IN THE MID 60S NW TO MID 70S SE ON WEDNESDAY. A NORMAL DIURNAL TEMPERATURE CURVE SHOULD RETURN WEDNESDAY NIGHT...ALTHOUGH THE TEMPERATURE GRADIENT WILL BE QUITE LARGE AND WILL DEPEND ON THE TIMING AND POSITION OF THE COLD FRONT...EXPECT LOWS IN THE UPPER 30S NORTH TO LOW 50S SOUTH WEDNESDAY NIGHT AND HIGHS IN THE LOW 40S NORTH TO MID 50S SOUTH ON THURSDAY AND DECREASING BEHIND THE FRONT. PRECIPITATION: THERE WILL BE A SLIGHT CHANCE OF PRECIP...MAINLY ACROSS THE WESTERN PORTIONS OF THE AREA WEDNESDAY...EVEN THOUGH THE MAIN PRE-FRONTAL CONVECTIVE RAINFALL REMAINS LARGELY ALONG OR WEST OF THE APPALACHIANS UNTIL WEDNESDAY AFT/EVE. SOUTHWESTERLY WINDS WILL BE QUITE STRONG ON WEDNESDAY AFT/EVE AS THE GRADIENT TIGHTENS AHEAD OF THE FRONT. LATE WEDNESDAY AFTERNOON IS STARTING TO SHAPE UP AS A HIGH SHEAR/LOW CAPE EVENT. FORECAST SOUNDINGS INDICATE 200-300 JOULES OF CAPE AND 0-3 KM SHEAR VALUES AROUND 35 KTS...MAINLY ALONG AND EAST OF I-95 AT THIS TIME. WITH SURFACE TEMPS EXPECTED IN THE MID 70S AND DEWPOINTS AROUND 60 DEGREES...THUNDERSTORMS WILL BE POSSIBLE WEDNESDAY AFTERNOON...THUS WILL INTRODUCE A SLIGHT CHANCE ACROSS THE EAST WITH THIS AFTERNOON`S FORECAST. THE LATEST 12Z ECMWF AND GFS MODEL RUNS ARE IN BETTER AGREEMENT WITH THE TIMING OF THE FROPA AND THE ASSOCIATED RAINFALL AS IT MOVES THROUGH THE AREA. THE LATEST RUNS SUGGEST THAT RAIN WILL BE LIKELY WEDNESDAY NIGHT... PROGRESSING NW TO SE THROUGH CENTRAL NC THROUGH MIDDAY THURSDAY. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 400 AM TUESDAY... THE LATEST MODELS ARE IN GOOD AGREEMENT IN BRING THE COLD FRONT SOUTH THROUGH CENTRAL NORTH CAROLINA THURSDAY MORNING. A WAVE IS EXPECTED TO FORM ALONG THE FRONT OVER UPSTATE SC... WHICH IN TURN HELPS TO HOLD UP THE COLD FRONT FOR SEVERAL HOURS FROM REACHING THE SOUTHERN ZONES. THE STRONGEST CAA SHOULD ALSO LAG THE FRONTAL PASSAGE BY SEVERAL HOURS IT APPEARS. THIS SUPPORTS THE CONTINUATION OF OUR CURRENT PREDOMINATELY RAIN FORECAST FOR THURSDAY WITH LIMITED POTENTIAL FOR WINTERY MIX NEAR THE END OF THE EVENT BETWEEN 18Z AND 23Z OR SO THURSDAY AFTERNOON FOR THE NORTHERN PIEDMONT AND NORTHERN COASTAL PLAIN. P-TYPE NOMOGRAMS SUPPORT SOME MIX WITH OR CHANGE TO FREEZING RAIN THEN EVEN A BRIEF PERIOD OF LIGHT SNOW/SLEET AT THE VERY VERY END OF THE EVENT... ACROSS THE FAR NORTHERN PIEDMONT DURING THE MID TO LATE AFTERNOON. FORECAST WET BULB TEMPERATURES DEPENDING ON THE MODEL OF CHOICE WITH SOME MODEL VARIABILITY ALSO TARGET THE NORTHERN ZONES FOR THIS POTENTIAL CHANGEOVER (ESPECIALLY NORTH OF A LINE EXTENDING FROM DAVIDSON TO RANDOLPH TO WAKE TO WARREN COUNTIES. PRECIPITATION SHOULD END QUICKLY BETWEEN 21Z-00Z... LIMITING THE WINDOW OF OPPORTUNITY FOR ICE TO BECOME A SIGNIFICANT WEATHER HAZARD. TO THE SOUTH... ALL RAIN IS EXPECTED WITH THE SLOWER TO COOL TEMPERATURES THERE. ALL IN ALL... A SIGNIFICANT WINTER WEATHER EVENT IS NOT EXPECTED AT THIS TIME WITH THE PREDOMINATE P-TYPE EXPECTED TO BE RAIN. THE CHANGEOVER WOULD OCCUR DURING THE AFTERNOON IN THE NORTH (IF AT ALL)... AND THE WARM GROUND TEMPERATURES AND TIME OF DAY WOULD LIMIT THE POTENTIAL TO MOSTLY ELEVATED SURFACES. THURSDAY NIGHT... BREEZY AND COLDER CONDITIONS COULD LEAD TO A QUICK FREEZE OF RESIDUAL WATER LEFT BEHIND WHICH MAY BECOME A WEATHER HAZARD. OTHERWISE... SIMPLY CLEARING AND COLD WITH LOWS IN THE 20-25 RANGE. FRIDAY IS EXPECTED TO BE MOSTLY SUNNY AND COLD WITH THE HEART OF THE ARCTIC COLD EXPECTED OVER THE OHIO VALLEY AND NORTHERN MID ATLANTIC STATES. WE WILL STILL BE A GOOD 20 DEGREES BELOW NORMAL WITH HIGHS EXPECTED IN THE UPPER 30S TO LOWER 40S. MODERATION WILL OCCUR IN THE TEMPERATURES OVER THE WEEKEND AS THE HIGH SLIPS SOUTH AND A WESTERLY FLOW DEVELOPS. HIGHS SHOULD RAPIDLY WARM INTO THE MID 40S TO LOWER 50S SATURDAY AND MID 50S TO LOWER 60S SUNDAY. A DRIER PATTERN IS ALSO ANTICIPATED THROUGH THE WEEKEND. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 745 PM MONDAY... STRONG (1032 MB) BUT TRANSIENT MODIFIED ARCTIC HIGH PRESSURE WILL RIDGE SOUTH INTO NC TONIGHT...THEN BUILD QUICKLY OFFSHORE ON TUE. INITIALLY VFR CONDITIONS THIS EVENING WILL BE THREATENED WITH FIRST A NARROW BAND OF LOW MVFR CLOUDS THAT NEAR TERM GUIDANCE WILL DEVELOP IN THE VICINITY OF KRWI IN THE NEXT COUPLE OF HOURS...THEN SWEEP...IN NORTHEASTERLY FLOW...TO THE SOUTHWEST ACROSS THE REMAINDER OF CENTRAL NC BETWEEN 02-07Z...LASTING AT ANY ONE LOCATION FOR JUST 2-3 HOURS BEFORE DEPARTING. MEANWHILE...AN AREA OF 4-5 THOUSAND FT CEILINGS OVER SC WILL EXPAND NORTH AS THE FLOW IN THAT LAYER STRENGTHENS AND CAUSES AIR TO GENTLY RISE ATOP THE AFOREMENTIONED RIDGE OF SURFACE HIGH PRESSURE AND ASSOCIATED NORTHEASTERLY FLOW BENEATH. CONFIDENCE IS RELATIVELY HIGH THAT CEILINGS WITHIN THIS AREA OF CLOUDS WILL THEN GRADUALLY LOWER TO INTO MVFR RANGE FROM WSW TO ENE ON TUE - FIRST AT KINT/KGSO AND LAST AT KRWI. THERE IS A LESSER...MEDIUM CHANCE (AROUND 50 PERCENT)... THAT CONDITIONS WILL LOWER TO IFR...WITH ACCOMPANYING PERIODS OF LIGHT RAIN/DRIZZLE MAINLY AT KGSO/KINT...AND PERHAPS AS FAR EAST AS KRDU...TUE MORNING. IF PRECIPITATION WERE TO INDEED OCCUR... TEMPERATURES WILL BE CLOSE TO FREEZING AT KINT/KGSO...WHERE AN ASSOCIATED PERIOD OF FREEZING PRECIPITATION WOULD BE POSSIBLE. OUTLOOK: TUE NIGHT: SUB-VFR CONDITIONS WILL CONTINUE TO DEVELOP NORTHEAST AND LOWER ACROSS CENTRAL NC THROUGH TUE NIGHT...SUCH THAT LIFR CONDITIONS WITH RESPECT TO CEILINGS AND POSSIBLY VISIBILITIES IN DENSE FOG...ARE EXPECTED TO PREVAIL LATE TUE NIGHT-WED MORNING...IN ASSOCIATION WITH THE SLOW RETREAT/APPROACH OF A WARM FRONT FROM THE SOUTHEAST. WED-THU: A RETURN TO VFR WILL BE PROBABLE WITH THE PASSAGE OF THE WARM FRONT LATER WED AT KFAY/KRWI/KRDU...BUT THIS IMPROVEMENT WILL BE DELAYED...OR MAY NOT OCCUR AT ALL AT KINT/KGSO...BEFORE A COLD FRONT AND AREA OF RAIN ARRIVE FROM THE NORTHWEST WED NIGHT...AND PERSIST THROUGH MUCH OF THU. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...CBL/BLS SHORT TERM...KC LONG TERM...BADGETT AVIATION...RAH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1222 PM CST TUE MAR 3 2015 .UPDATE... ISSUED AT 1220 PM CST TUE MAR 3 2015 WE WILL ISSUE A WIND ADVISORY THROUGH 00Z IN THE VALLEY...GETTING WINDS INTO CRITERIA NOW. OTHERWISE...THE FORECAST REMAINS UNCHANGED FROM PREVIOUS UPDATE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS. MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH. SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING. SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH. SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW. BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR. WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD. N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD TO MINIMAL TEMPERATURE RECOVERY. TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND CHILL HEADLINES. WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY. MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL COLD START. GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES WILL BE MUCH CLOSER TO AVERAGE. FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1220 PM CST TUE MAR 3 2015 WINDS WILL GUST NEAR OR OVER 30KTS AT TIMES THROUGH THE AFTERNOON...BEFORE GRADUALLY SUBSIDING BY THIS EVENING. A MIX OF MVFR TO LOW VFR CEILINGS ARE EXPECTED THROUGH THE AFTERNOON...WITH SOME CLEARING BY THIS EVENING. SOME REDUCED VISIBILITIES ARE EXPECTED AT TIMES THIS AFTERNOON ESPECIALLY AT KTVF/KBJI...OR WITHIN ANY BRIEF SNOW SHOWERS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ053. WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006>008-014>016- 024-026>030-038-039-049-052-054. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ024- 027>032-040. WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ001>004-007. && $$ UPDATE...DK SHORT TERM...VOELKER LONG TERM...GODON/VOELKER AVIATION...MAKOWSKI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
916 AM CST TUE MAR 3 2015 .UPDATE... ISSUED AT 910 AM CST TUE MAR 3 2015 WE WILL BE CANCELING CASS/CLAY/SARGENT AND RANSOM COUNTIES FROM THE WINTER WEATHER ADVISORY...WITH LITTLE SNOW HERE AND NO BLOWING SNOW ISSUES. WE WILL ISSUE A WIND ADVISORY FOR RANSOM/SARGENT. OTHERWISE...NO OTHER CHANGES PLANNED BUT WE WILL MONITOR POTENTIAL FOR A WIND ADVISORY INTO THE WESTERN EDGE OF THE RED RIVER VALLEY. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS. MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH. SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING. SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH. SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW. BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR. WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD. N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD TO MINIMAL TEMPERATURE RECOVERY. TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND CHILL HEADLINES. WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY. MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL COLD START. GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES WILL BE MUCH CLOSER TO AVERAGE. FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 633 AM CST TUE MAR 3 2015 LOWER CIGS MASKED BY CI HOWEVER APPEARS TO BE QUITE A BIT OF MVFR CIGS OVER ALL BUT DVL BASIN WERE CLEARING TAKING PLACE. SOUNDINGS SUPPORTIVE OF SOME SC DEVELOPMENT DURING THE DAY HOWEVER KEPT MVFR CIGS LIMITED TO THE AM. STRONG NW WINDS SPREADING ACROSS THE FA. LOWER VSBY IN SN/BLSN SHOULD REMAIN SOUTH OF TAF SITES. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006-014-015-024- 026-028-038-049-052. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ053. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ024- 027>032-040. && $$ UPDATE...DK SHORT TERM...VOELKER LONG TERM...GODON/VOELKER AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
647 AM CST TUE MAR 3 2015 .UPDATE... ISSUED AT 633 AM CST TUE MAR 3 2015 VIA KABR WSR-88D RADAR RETURNS SHRINKING AND DIMINISHING IN INTENSITY AND VSBY FROM METARS RISING. HAVE SERIOUS DOUBTS THAT NORTHERN COUNTIES WILL REACH ADVISORY CRITERIA/CONDITIONS HOWEVER WILL MAINTAIN THOSE HEADLINES AS -SN CONTINUES AND MORNING COMMUTE SOON TO START. JUST SOUTH AND EAST OF THE FA SNOW REPORTS RANGING FROM 2-3 INCHES SO THIS AREA OK. IF CURRENT TRENDS CONTINUE DAY SHIFT CAN START TRIMMING ADVISORY AREA AT MID MORNING UPDATE. WINDS ALSO YET TO REV UP OVER WESTERN ADVISORY AREA HOWEVER SHOULD INCREASE ONCE MIX LAYER DEEPENS. NO CHANGES PLANNED. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS. MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH. SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING. SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH. SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW. BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR. WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD. N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD TO MINIMAL TEMPERATURE RECOVERY. TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND CHILL HEADLINES. WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY. MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL COLD START. GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES WILL BE MUCH CLOSER TO AVERAGE. FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 633 AM CST TUE MAR 3 2015 LOWER CIGS MASKED BY CI HOWEVER APPEARS TO BE QUITE A BIT OF MVFR CIGS OVER ALL BUT DVL BASIN WERE CLEARING TAKING PLACE. SOUNDINGS SUPPORTIVE OF SOME SC DEVELOPMENT DURING THE DAY HOWEVER KEPT MVFR CIGS LIMITED TO THE AM. STRONG NW WINDS SPREADING ACROSS THE FA. LOWER VSBY IN SN/BLSN SHOULD REMAIN SOUTH OF TAF SITES. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006-014-015-024- 026-028-038. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ039- 049-052-053. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ003- 024-027>032-040. && $$ UPDATE...VOELKER SHORT TERM...VOELKER LONG TERM...GODON/VOELKER AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
328 AM CST TUE MAR 3 2015 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS. MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH. SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING. SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH. SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW. BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR. WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD. N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD TO MINIMAL TEMPERATURE RECOVERY. TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND CHILL HEADLINES. WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 320 AM CST TUE MAR 3 2015 SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY. MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL COLD START. GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES WILL BE MUCH CLOSER TO AVERAGE. FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1138 PM CST MON MAR 2 2015 FOG LOOP/SURFACE OBS INDICATED MID LEVEL CLOUDS AROUND 7 THOUSAND FT WAS EAST OF A LINE FROM ROX TO WYNDMERE ND. HIGH LEVEL CLOUDS WERE LOCATED OVER NORTHEAST ND. POST FRONTAL MVFR CIGS WERE OVER WESTERN ND. LOW CLOUDS WERE BEING MASKED BY A HIGHER LEVEL CLOUD DECK. CIGS EXPECTED TO LOWER AS COLD FRONT MOVES INTO THE AREA OVER THE NEXT FEW HOURS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006-014-015-024- 026-028-038. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ039- 049-052-053. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ003- 024-027>032-040. && $$ SHORT TERM...VOELKER LONG TERM...GODON/VOELKER AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1204 PM EST TUE MAR 3 2015 .SYNOPSIS... A WARM FRONT WILL LIFT NORTHWARD TODAY ALLOWING FREEZING RAIN TO TRANSITION TO RAIN. A COLD FRONT WILL MOVE THROUGH TONIGHT INTO WEDNESDAY MORNING. ANOTHER WAVE WILL ALLOW FOR ACCUMULATING SNOW WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...WITH SLOW TEMPERATURE RISE...HAVE EXTENDED FREEZING RAIN ADVISORY ACRS THE NORTH TO 3 PM. PREVIOUS... ACTIVE WEATHER PATTERN WITH INITIAL FOCUS ON THE FREEZING RAIN POTENTIAL THIS MORNING AND THEN SWITCHING TO HEAVY RAIN TONIGHT AND HEAVY SNOW WED/THU. ISENTROPIC LIFT LEAD TO AN AXIS OF FREEZING RAIN ACRS ILN/S NORTHERN COUNTIES EARLY THIS MORNING. THIS PRECIPITATION AXIS HAS PIVOTED NORTH AND EAST OF ILN/S FA. ILN/S 12Z MORNING SOUNDING SHOWS WARM BULGE ALOFT OF 6 DEG C AROUND 78O MB BUT RATHER DRY AIR BELOW THIS. WITH LIGHT ECHO RETURNS...THIS HAS LIMITED ANY FREEZING RAIN IN THE SOUTH THIS MORNING. BETTER LIFT COMING INTO PLAY BY LATE MORNING AS FAVORABLE LOW LEVEL CONVERGENCE DEVELOPS ASSOCIATED WITH 60-65 KT LLJ. SEEING THIS BETTER FORCING LEADING TO AN INCREASE IN RADAR RETURNS ACRS INDIANA. CURRENTLY IN LULL BUT HAVE SHOWN THIS TREND WITH AN INCREASE IN POPS FROM THE WEST LATER THIS MORNING. HAVE ALLOWED THE SRN TIER OF THE FREEZING RAIN ADVISORY TO EXPIRE WITH TEMPERATURES WARMING ABOVE FREEZING. SOME SFC ROAD/WALKWAY TEMPS WILL LAG. THEREFORE...HAVE AN SPS THRU NOON ACRS THE FAR SOUTH. HAVE KEPT NRN FREEZING RAIN ADVISORY THRU 1 PM WITH TEMPERATURES EXPECTED TO WARM ABOVE FREEZING THIS AFTN AS LOW LEVEL WINDS VEER FROM THE EAST TO THE SOUTH. PREVIOUS DISCUSSION... FREEZING RAIN AND SLEET ARE MOVING INTO NW PORTIONS OF THE FA. THE HIGHEST ICE ACCUMULATIONS OF AROUND FIVE HUNDREDTHS OF AN INCH ARE EXPECTED IN THIS AREA. ELSEWHERE ACROSS THE AREA AROUND A COUPLE HUNDREDTHS OF AN INCH OF ICE ACCUMULATION WILL BE POSSIBLE THIS MORNING. THE LOWEST ICE ACCUMULATIONS ARE EXPECTED ACROSS NORTHERN KENTUCKY WHERE TEMPERATURES WILL BE BELOW FREEZING FOR THE SHORTEST AMOUNT OF TIME AND PRECIPITATION WILL BE LIGHTER. DUE TO THIS REASON HELD OFF ON A FREEZING RAIN ADVISORY FOR A PORTION OF NORTHERN KENTUCKY AND EXTREME SOUTHERN INDIANA. DID GO AHEAD AND EXPAND THE FREEZING RAIN ADVISORY SOUTHWARD FROM PREVIOUS FORECAST SINCE EVEN LIGHT ICE AMOUNTS CAN CREATE HAZARDOUS DRIVING CONDITIONS. CHANGED A TIER OF THE WINTER WEATHER ADVISORY TO A FREEZING RAIN ADVISORY SINCE THE MAIN PRECIPITATION TYPE IS EXPECTED TO BE FREEZING RAIN. KEPT A TIER OF WINTER WEATHER ADVISORY ACROSS THE NORTH DUE TO THE POSSIBILITY OF SOME SLEET MIXING IN. TEMPERATURES WILL RISE THROUGH THE DAY AS A WARM FRONT PUSHES NORTHWARD AND FREEZING RAIN WILL GRADUALLY TRANSITION TO RAIN. THERE IS SOME CONCERN THAT NORTHERN PORTIONS OF THE FA WILL NOT GET ABOVE FREEZING BY THE TIME THE WINTER WEATHER ADVISORY EXPIRES HOWEVER BELIEVE THAT IT WILL BE CLOSE AND THEREFORE DID NOT CHANGE THE END TIME OF THE WINTER WEATHER ADVISORY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... RAIN WILL PICK UP IN INTENSITY ACROSS SE PORTIONS OF THE FA THIS EVENING INTO TONIGHT. OVER AN INCH OF RAIN WILL BE POSSIBLE ACROSS PORTIONS OF THE AREA AND DUE TO THIS HAVE CONTINUED THE FLOOD WATCH. A COLD FRONT WILL WORK INTO THE AREA TONIGHT. THERE IS NOT A LOT OF INSTABILITY WITH THIS SYSTEM AND THEREFORE DECIDED TO LEAVE THUNDER OUT OF THE FORECAST. AS COLDER AIR BEGINS TO WORK INTO THE REGION A MIX OF PRECIPITATION PRIMARILY NW OF DAYTON WILL BE POSSIBLE LATE IN THE OVERNIGHT HOURS. TEMPERATURES ARE EXPECTED TO FALL DURING THE DAY ON WEDNESDAY. AS THEY DO RAIN WILL TRANSITION OVER TO SNOW. DURING THIS TRANSITION PERIOD...SLEET AND FREEZING RAIN WILL BE POSSIBLE. ANY ICE ACCUMULATION FROM FREEZING RAIN IS EXPECTED TO BE MINIMAL. PRECIPITATION WILL BRIEFLY TAPER DOWN DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ON WEDNESDAY HOWEVER ANOTHER WAVE OF PRECIPITATION WILL BEGIN TO WORK INTO THE REGION WEDNESDAY AFTERNOON. THIS PRECIPITATION IS EXPECTED TO BE PRIMARILY SNOW HOWEVER A WINTRY MIX WILL STILL BE POSSIBLE ACROSS PORTIONS OF NORTHERN KENTUCKY AND SE OHIO THROUGH THE AFTERNOON HOURS. PRECIPITATION WILL CHANGE OVER TO ALL SNOW WEDNESDAY EVENING. SNOW WILL CONTINUE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING BEFORE BEGINNING TO TAPER OFF. SNOW WILL BE HEAVY AT TIMES ESPECIALLY ACROSS THE SE HALF OF THE FA. THERE WILL BE A SHARP CUT OFF IN AMOUNTS FURTHER NW OF INTERSTATE 71. EXPANDED THE WINTER STORM WATCH TO COVER ALL BUT FRANKLIN INDIANA AND BUTLER COUNTY OHIO OF THE 4 INCH SNOW CRITERIA. THERE IS SOME UNCERTAINTY ON THE NW EDGE OF THE SNOW AND THEREFORE DECIDED TO LEAVE THOSE COUNTIES OUT AT THIS TIME. HAVE THE NORTHERN TIER OF THE WATCH WITH 4 TO 6 INCHES OF SNOW AND THE REST OF THE WATCH WITH AROUND 6 TO 9 INCHES OF SNOW. ISOLATED HIGHER AMOUNTS CANNOT BE RULED OUT. THERE IS STILL SOME UNCERTAINTY ON HOW QUICKLY THE RAIN WILL TRANSITION TO SNOW ON WEDNESDAY AND THUS THERE IS STILL SOME UNCERTAINTY IN FORECAST SNOW AMOUNTS. SNOW WILL MOVE OUT OF THE FA DURING THE LATE MORNING HOURS AND INTO THE AFTERNOON ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION THURSDAY NIGHT AND CLOUD COVER WILL DECREASE. ALTHOUGH SOME RETURN SOUTHERLY FLOW WILL DEVELOP...WITH FRESH SNOW COVER AND MOSTLY CLEAR SKIES EXPECT TEMPERATURES TO DROP DOWN TO THE NEGATIVE SINGLE DIGITS ACROSS MANY LOCATIONS. && .LONG TERM /FRIDAY THROUGH MONDAY/... FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES EAST WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES. MOSTLY SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING SOUTHERLY RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL GET ON FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT LINGERING SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY. WILL RANGE HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. LOWS FRIDAY NIGHT WILL GENERALLY BE IN THE TEENS. FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS. TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL STILL AVERAGE BELOW NORMAL FOR EARLY MARCH. HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE BIT BELOW NORMAL FOR EARLY MARCH. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/... FREEZING RAIN AND DRIZZLE IS CURRENTLY MOVING INTO THE AREA FROM WEST TO EAST THIS MORNING WITH KDAY ALREADY REPORTING FZDZ. EXPECT LIGHT FREEZING RAIN AND DRIZZLE TO CONTINUE THIS MORNING WITH TEMPERATURES SLOWLY WARMING. LATEST HRRR MODEL RUN SHOWS THAT THERE MIGHT BE A BRIEF BREAK IN THE PRECIP THIS MORNING BUT QUICKLY REDEVELOPS PRECIP ACROSS THE AREA. GFS/ NAM AND RAP SOUNDINGS ALL SHOW TEMPERATURES RISING ABOVE FREEZING BY NOON TODAY. FORECAST SOUNDINGS ALSO SHOW CIGS FALLING INTO IFR CONDITIONS THIS AFTERNOON. LOOKING AT UPSTREAM OBS AM A LITTLE HESITANT WITH THIS. A COLD FRONT WILL THEN MOVE THROUGH THE AREA LATE TONIGHT INTO EARLY WEDNESDAY MORNING. AS THE FRONT MOVES THROUGH THE AREA MUCH COLDER AIR WILL FILTER IN. THIS WILL ALLOW PRECIP TO AGAIN TRANSITION BACK TO SNOW. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL POTENTIALLY LINGER THROUGH THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR OHZ026-034-035-042>046-051>056-060>062. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ063>065-070>074-077. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR OHZ063>065-071>074-077>082-088. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR OHZ063>065-071>074-077>082-088. KY...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ089>100. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR KYZ089>100. IN...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR INZ050-058-059. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR INZ066-073-074. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR INZ073>075-080. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR INZ075-080. && $$ SYNOPSIS...NOVAK NEAR TERM...AR SHORT TERM...NOVAK LONG TERM...HICKMAN AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1022 AM EST TUE MAR 3 2015 .SYNOPSIS... A WARM FRONT...FOLLOWED BY A COLD FRONT TONIGHT. FRONT STALLS TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT WEDNESDAY NIGHT. SNOW SHOWERS LINGER ON THURSDAY. HIGH PRESSURE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... 10 AM UPDATE...NO SIGNIFICANT CHANGES. LETTING MUCH OF THE FREEZING RAIN ADVISORY EXPIRE AT 10 AM. 645 AM UPDATE... PRECIP GRADUALLY TRYING TO FILL IN UPSTREAM...BUT STILL FALLING OUT OF A MID DECK. HRRR INSISTS ON THIS EXPANDING AND REACHING THE GROUND INTO SE OH IN THE 13 TO 15Z TIME FRAME. WILL CONT HEADLINE AS IS FOR NOW. PREVIOUS DISCUSSION BELOW... A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP BREAKING OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH EXTENT OF PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A CONCERN FOR FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE VALLEYS AND HOLLOWS. AFTER COORDINATING WITH SURROUNDING OFFICES...ELECTED TO EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH AND PORTIONS OF W WV ALONG OH RIVER. LOOKING AT ONLY A FEW HUNDREDTHS AT BEST. ADJUSTED END TIMES TO REFLECT EXPECTED WARMING OF TEMPS. LEFT NE KY OUT ATTM AS CONFIDENCE NOT AS HIGH THAT PRECIP WILL BREAK OUT OVER THAT AREA BEFORE TEMPS CAN RECOVER. WILL HANDLE WITH AN SPS FOR NOW AND MONITOR TRENDS. ACROSS THE N MOUNTAINS...THERE MAY MORE IN THE WAY OF SLEET INITIALLY VS FZRA. ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS. THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z. STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD. FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE 50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA. DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR FLOODING. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MODELS ARE STILL IN DISAGREEMENT WITH HOW FAR SOUTH THE COLDER AIR WILL PUSH INTO THE REGION ON WEDNESDAY. THIS IS CRITICAL FOR THE TYPE OF PRECIPITATION THAT WILL OCCUR WEDNESDAY NIGHT WITH A WAVE MOVING ALONG THE FRONT. ALSO DUE TO THE DIFFERENCES IN THE HANDLING OF THE COLD AIR...PLACEMENT OF HIGHER PRECIPITATION AMOUNTS VARY CONSIDERABLY. THIS LEADS TO A LOW CONFIDENCE FORECAST. NAM/SREF WOULD INDICATE SNOW IN CENTRAL OHIO...WITH A LARGE BAND OF SIGNIFICANT AMOUNTS OF SLEET FROM NE KY/S OH INTO CENTRAL WV AND THE WV MOUNTAINS. GFS AND ECMWF ARE MUCH COLDER AND WOULD PRODUCE SIGNIFICANTLY MORE SNOW INSTEAD OF SLEET. IN ANY CASE...FEEL THAT A WINTER STORM WATCH IS WARRANTED AT THIS POINT...ALTHOUGH THE TYPE OF WEATHER IS UNCERTAIN. WILL NOT ISSUE FOR THE SOUTHERN COAL FIELDS AND VA HOWEVER...AS ODDS OF BEING RAIN ARE MUCH LARGER THERE...STILL CAUSING FLOODING CONCERNS. SOME UPSLOPE SNOW LOOKS TO BE A GOOD BET FOR THURSDAY AS COLD AIR MOVES IN BEHIND THE SYSTEM. WILL INCREASE POPS SOME. && .LONG TERM /FRIDAY THROUGH MONDAY/... HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES THROUGHOUT. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... 15Z TUESDAY THRU 12Z WEDNESDAY... A WARM FRONT WILL LIFT NORTH OF THE AREA THIS AFTERNOON...WITH VFR CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL IFR CEILINGS AND VSBY IN RAIN AND FOG ON E SLOPES. ANY VERY LIGHT FREEZING RAIN NORTH WILL END BY 18Z AS TEMPERATURES RISE ABOVE FREEZING. THERE WILL BE A BREAK IN THE RAIN THIS AFTERNOON. LOOK FOR GENERAL MVFR CONDITIONS TO PREVAIL ACROSS SE OH AND POSSIBLY JUST VFR CONDITIONS IN THE WARM SECTOR ACROSS EKN AMID DOWNSLOPE WINDS. IFR CONDITIONS LOOK TO DEVELOP ON E SLOPES INCLUDING KBKW THIS AFTERNOON. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND NIGHT. THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY 09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR OR WORSE. SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE TOPS THIS MORNING...INCLUDING KBKW. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL VARY WITH ONSET OF THE RAIN TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20 CRW CONSISTENCY H H M M H H H H H H H H HTS CONSISTENCY M H M H H H H H M M M M BKW CONSISTENCY H H H H M M M M M H M M EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H M M H H H H H M M M CKB CONSISTENCY H H H H M M M M M M H H AFTER 18Z WEDNESDAY... IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN/SLEET OR SNOW LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. IFR IN SNOW SHOWERS THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY MORNING FOR WVZ005>011-013>020-024>040-046-047. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR WVZ005>011-013>020-026-029. WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR WVZ027-028-030>032-035>040-046-047. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ046-047. OH...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY MORNING FOR OHZ066-067-075-076-083>087. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR OHZ066-067-075-076-083>087. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ066-067-075-076. KY...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY MORNING FOR KYZ101>103-105. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ101>103-105. VA...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY MORNING FOR VAZ003-004. && $$ SYNOPSIS...JS/RPY/30 NEAR TERM...JMV/30 SHORT TERM...RPY LONG TERM...JS AVIATION...JMV/30
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1001 AM EST TUE MAR 3 2015 .SYNOPSIS... A WARM FRONT WILL LIFT NORTHWARD TODAY ALLOWING FREEZING RAIN TO TRANSITION TO RAIN. A COLD FRONT WILL MOVE THROUGH TONIGHT INTO WEDNESDAY MORNING. ANOTHER WAVE WILL ALLOW FOR ACCUMULATING SNOW WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ACTIVE WEATHER PATTERN WITH INITIAL FOCUS ON THE FREEZING RAIN POTENTIAL THIS MORNING AND THEN SWITCHING TO HEAVY RAIN TONIGHT AND HEAVY SNOW WED/THU. ISENTROPIC LIFT LEAD TO AN AXIS OF FREEZING RAIN ACRS ILN/S NORTHERN COUNTIES EARLY THIS MORNING. THIS PRECIPITATION AXIS HAS PIVOTED NORTH AND EAST OF ILN/S FA. ILN/S 12Z MORNING SOUNDING SHOWS WARM BULGE ALOFT OF 6 DEG C AROUND 78O MB BUT RATHER DRY AIR BELOW THIS. WITH LIGHT ECHO RETURNS...THIS HAS LIMITED ANY FREEZING RAIN IN THE SOUTH THIS MORNING. BETTER LIFT COMING INTO PLAY BY LATE MORNING AS FAVORABLE LOW LEVEL CONVERGENCE DEVELOPS ASSOCIATED WITH 60-65 KT LLJ. SEEING THIS BETTER FORCING LEADING TO AN INCREASE IN RADAR RETURNS ACRS INDIANA. CURRENTLY IN LULL BUT HAVE SHOWN THIS TREND WITH AN INCREASE IN POPS FROM THE WEST LATER THIS MORNING. HAVE ALLOWED THE SRN TIER OF THE FREEZING RAIN ADVISORY TO EXPIRE WITH TEMPERATURES WARMING ABOVE FREEZING. SOME SFC ROAD/WALKWAY TEMPS WILL LAG. THEREFORE...HAVE AN SPS THRU NOON ACRS THE FAR SOUTH. HAVE KEPT NRN FREEZING RAIN ADVISORY THRU 1 PM WITH TEMPERATURES EXPECTED TO WARM ABOVE FREEZING THIS AFTN AS LOW LEVEL WINDS VEER FROM THE EAST TO THE SOUTH. PREVIOUS DISCUSSION... FREEZING RAIN AND SLEET ARE MOVING INTO NW PORTIONS OF THE FA. THE HIGHEST ICE ACCUMULATIONS OF AROUND FIVE HUNDREDTHS OF AN INCH ARE EXPECTED IN THIS AREA. ELSEWHERE ACROSS THE AREA AROUND A COUPLE HUNDREDTHS OF AN INCH OF ICE ACCUMULATION WILL BE POSSIBLE THIS MORNING. THE LOWEST ICE ACCUMULATIONS ARE EXPECTED ACROSS NORTHERN KENTUCKY WHERE TEMPERATURES WILL BE BELOW FREEZING FOR THE SHORTEST AMOUNT OF TIME AND PRECIPITATION WILL BE LIGHTER. DUE TO THIS REASON HELD OFF ON A FREEZING RAIN ADVISORY FOR A PORTION OF NORTHERN KENTUCKY AND EXTREME SOUTHERN INDIANA. DID GO AHEAD AND EXPAND THE FREEZING RAIN ADVISORY SOUTHWARD FROM PREVIOUS FORECAST SINCE EVEN LIGHT ICE AMOUNTS CAN CREATE HAZARDOUS DRIVING CONDITIONS. CHANGED A TIER OF THE WINTER WEATHER ADVISORY TO A FREEZING RAIN ADVISORY SINCE THE MAIN PRECIPITATION TYPE IS EXPECTED TO BE FREEZING RAIN. KEPT A TIER OF WINTER WEATHER ADVISORY ACROSS THE NORTH DUE TO THE POSSIBILITY OF SOME SLEET MIXING IN. TEMPERATURES WILL RISE THROUGH THE DAY AS A WARM FRONT PUSHES NORTHWARD AND FREEZING RAIN WILL GRADUALLY TRANSITION TO RAIN. THERE IS SOME CONCERN THAT NORTHERN PORTIONS OF THE FA WILL NOT GET ABOVE FREEZING BY THE TIME THE WINTER WEATHER ADVISORY EXPIRES HOWEVER BELIEVE THAT IT WILL BE CLOSE AND THEREFORE DID NOT CHANGE THE END TIME OF THE WINTER WEATHER ADVISORY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... RAIN WILL PICK UP IN INTENSITY ACROSS SE PORTIONS OF THE FA THIS EVENING INTO TONIGHT. OVER AN INCH OF RAIN WILL BE POSSIBLE ACROSS PORTIONS OF THE AREA AND DUE TO THIS HAVE CONTINUED THE FLOOD WATCH. A COLD FRONT WILL WORK INTO THE AREA TONIGHT. THERE IS NOT A LOT OF INSTABILITY WITH THIS SYSTEM AND THEREFORE DECIDED TO LEAVE THUNDER OUT OF THE FORECAST. AS COLDER AIR BEGINS TO WORK INTO THE REGION A MIX OF PRECIPITATION PRIMARILY NW OF DAYTON WILL BE POSSIBLE LATE IN THE OVERNIGHT HOURS. TEMPERATURES ARE EXPECTED TO FALL DURING THE DAY ON WEDNESDAY. AS THEY DO RAIN WILL TRANSITION OVER TO SNOW. DURING THIS TRANSITION PERIOD...SLEET AND FREEZING RAIN WILL BE POSSIBLE. ANY ICE ACCUMULATION FROM FREEZING RAIN IS EXPECTED TO BE MINIMAL. PRECIPITATION WILL BRIEFLY TAPER DOWN DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ON WEDNESDAY HOWEVER ANOTHER WAVE OF PRECIPITATION WILL BEGIN TO WORK INTO THE REGION WEDNESDAY AFTERNOON. THIS PRECIPITATION IS EXPECTED TO BE PRIMARILY SNOW HOWEVER A WINTRY MIX WILL STILL BE POSSIBLE ACROSS PORTIONS OF NORTHERN KENTUCKY AND SE OHIO THROUGH THE AFTERNOON HOURS. PRECIPITATION WILL CHANGE OVER TO ALL SNOW WEDNESDAY EVENING. SNOW WILL CONTINUE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING BEFORE BEGINNING TO TAPER OFF. SNOW WILL BE HEAVY AT TIMES ESPECIALLY ACROSS THE SE HALF OF THE FA. THERE WILL BE A SHARP CUT OFF IN AMOUNTS FURTHER NW OF INTERSTATE 71. EXPANDED THE WINTER STORM WATCH TO COVER ALL BUT FRANKLIN INDIANA AND BUTLER COUNTY OHIO OF THE 4 INCH SNOW CRITERIA. THERE IS SOME UNCERTAINTY ON THE NW EDGE OF THE SNOW AND THEREFORE DECIDED TO LEAVE THOSE COUNTIES OUT AT THIS TIME. HAVE THE NORTHERN TIER OF THE WATCH WITH 4 TO 6 INCHES OF SNOW AND THE REST OF THE WATCH WITH AROUND 6 TO 9 INCHES OF SNOW. ISOLATED HIGHER AMOUNTS CANNOT BE RULED OUT. THERE IS STILL SOME UNCERTAINTY ON HOW QUICKLY THE RAIN WILL TRANSITION TO SNOW ON WEDNESDAY AND THUS THERE IS STILL SOME UNCERTAINTY IN FORECAST SNOW AMOUNTS. SNOW WILL MOVE OUT OF THE FA DURING THE LATE MORNING HOURS AND INTO THE AFTERNOON ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION THURSDAY NIGHT AND CLOUD COVER WILL DECREASE. ALTHOUGH SOME RETURN SOUTHERLY FLOW WILL DEVELOP...WITH FRESH SNOW COVER AND MOSTLY CLEAR SKIES EXPECT TEMPERATURES TO DROP DOWN TO THE NEGATIVE SINGLE DIGITS ACROSS MANY LOCATIONS. && .LONG TERM /FRIDAY THROUGH MONDAY/... FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES EAST WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES. MOSTLY SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING SOUTHERLY RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL GET ON FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT LINGERING SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY. WILL RANGE HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. LOWS FRIDAY NIGHT WILL GENERALLY BE IN THE TEENS. FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS. TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL STILL AVERAGE BELOW NORMAL FOR EARLY MARCH. HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE BIT BELOW NORMAL FOR EARLY MARCH. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... FREEZING RAIN AND DRIZZLE IS CURRENTLY MOVING INTO THE AREA FROM WEST TO EAST THIS MORNING WITH KDAY ALREADY REPORTING FZDZ. EXPECT LIGHT FREEZING RAIN AND DRIZZLE TO CONTINUE THIS MORNING WITH TEMPERATURES SLOWLY WARMING. LATEST HRRR MODEL RUN SHOWS THAT THERE MIGHT BE A BRIEF BREAK IN THE PRECIP THIS MORNING BUT QUICKLY REDEVELOPS PRECIP ACROSS THE AREA. GFS/ NAM AND RAP SOUNDINGS ALL SHOW TEMPERATURES RISING ABOVE FREEZING BY NOON TODAY. FORECAST SOUNDINGS ALSO SHOW CIGS FALLING INTO IFR CONDITIONS THIS AFTERNOON. LOOKING AT UPSTREAM OBS AM A LITTLE HESITANT WITH THIS. A COLD FRONT WILL THEN MOVE THROUGH THE AREA LATE TONIGHT INTO EARLY WEDNESDAY MORNING. AS THE FRONT MOVES THROUGH THE AREA MUCH COLDER AIR WILL FILTER IN. THIS WILL ALLOW PRECIP TO AGAIN TRANSITION BACK TO SNOW. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL POTENTIALLY LINGER THROUGH THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ042-051>055-060>065-070>074-077. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ026-034-035-043>046-056. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR OHZ063>065-071>074-077>082-088. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR OHZ063>065-071>074-077>082-088. KY...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ089>100. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR KYZ089>100. IN...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR INZ050-058-059-066-073-074. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR INZ073>075-080. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR INZ075-080. && $$ SYNOPSIS...NOVAK NEAR TERM...AR SHORT TERM...NOVAK LONG TERM...HICKMAN AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
904 AM EST TUE MAR 3 2015 .SYNOPSIS... A WARM FRONT WILL LIFT NORTHWARD TODAY ALLOWING FREEZING RAIN TO TRANSITION TO RAIN. A COLD FRONT WILL MOVE THROUGH TONIGHT INTO WEDNESDAY MORNING. ANOTHER WAVE WILL ALLOW FOR ACCUMULATING SNOW WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ACTIVE WEATHER PATTERN WITH INTIAL FOCUS ON THE FREEZING RAIN POTENTIAL THIS MORNING AND THEN SWITCHING TO HEAVY RAIN TONIGHT AND HEAVY SNOW WED/THU. ISENTROPIC LIFT HAS LEAD TO AN AXIS OF FREEZING RAIN ACRS ILN/S NORTHERN COUNTIES EARLY THIS MORNING. REPORTS AND RADAR INDICATED A MIX WITH SLEET AT TIME ACRS CENTRAL OHIO. THIS BAND IS SHIFTING N WITH BEST COVERAGE OF PCPN EXITING ILN/S FA. 12Z ILN SOUNDING SHOWS WARM BULGE ALOFT OF 6 DEG C AROUND 78O MB BUT RATHER DRY AIR BELOW THIS. WITH LIGHT ECHO RETURNS...THIS HAS LIMITED ANY FREEZING RAIN IN THE SOUTH THIS MORNING. BETTER LIFT COMES INTO PLAY BY LATE MORNING AS FAVORABLE LOW LEVEL CONVERGENCE DEVELOPS ASSOICATED WITH 60-65 KT LLJ. SEEING THIS BETTER FORCING LEADING TO AN INCREASE IN RADAR RETURNS ACRS CENTRAL INDIANA AND WESTERN INDIANA. HAVE SHOWN THIS TREND OF DIMINISHING POPS WITH AN INCREASE FROM THE WEST LATER THIS MORNING. HAVE KEPT CURRENT FREEZING RAIN HEADLINES IN PLACE WITH SFC TEMPERATURES RUNNING FROM THE MID/UPR 20S NORTH TO THE LOWER 30S FAR SOUTH. MAY HAVE TO EXTEND FREEZING RAIN ADVISORY ACRS THE NE WITH EASTERLY FLOW RESULTING IN A SLOW TEMPERATURE RISE. WILL CONTINUE TO MONITOR TEMP TRENDS REGARDING. PREVIOUS DISCUSSION... FREEZING RAIN AND SLEET ARE MOVING INTO NW PORTIONS OF THE FA. THE HIGHEST ICE ACCUMULATIONS OF AROUND FIVE HUNDREDTHS OF AN INCH ARE EXPECTED IN THIS AREA. ELSEWHERE ACROSS THE AREA AROUND A COUPLE HUNDREDTHS OF AN INCH OF ICE ACCUMULATION WILL BE POSSIBLE THIS MORNING. THE LOWEST ICE ACCUMULATIONS ARE EXPECTED ACROSS NORTHERN KENTUCKY WHERE TEMPERATURES WILL BE BELOW FREEZING FOR THE SHORTEST AMOUNT OF TIME AND PRECIPITATION WILL BE LIGHTER. DUE TO THIS REASON HELD OFF ON A FREEZING RAIN ADVISORY FOR A PORTION OF NORTHERN KENTUCKY AND EXTREME SOUTHERN INDIANA. DID GO AHEAD AND EXPAND THE FREEZING RAIN ADVISORY SOUTHWARD FROM PREVIOUS FORECAST SINCE EVEN LIGHT ICE AMOUNTS CAN CREATE HAZARDOUS DRIVING CONDITIONS. CHANGED A TIER OF THE WINTER WEATHER ADVISORY TO A FREEZING RAIN ADVISORY SINCE THE MAIN PRECIPITATION TYPE IS EXPECTED TO BE FREEZING RAIN. KEPT A TIER OF WINTER WEATHER ADVISORY ACROSS THE NORTH DUE TO THE POSSIBILITY OF SOME SLEET MIXING IN. TEMPERATURES WILL RISE THROUGH THE DAY AS A WARM FRONT PUSHES NORTHWARD AND FREEZING RAIN WILL GRADUALLY TRANSITION TO RAIN. THERE IS SOME CONCERN THAT NORTHERN PORTIONS OF THE FA WILL NOT GET ABOVE FREEZING BY THE TIME THE WINTER WEATHER ADVISORY EXPIRES HOWEVER BELIEVE THAT IT WILL BE CLOSE AND THEREFORE DID NOT CHANGE THE END TIME OF THE WINTER WEATHER ADVISORY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... RAIN WILL PICK UP IN INTENSITY ACROSS SE PORTIONS OF THE FA THIS EVENING INTO TONIGHT. OVER AN INCH OF RAIN WILL BE POSSIBLE ACROSS PORTIONS OF THE AREA AND DUE TO THIS HAVE CONTINUED THE FLOOD WATCH. A COLD FRONT WILL WORK INTO THE AREA TONIGHT. THERE IS NOT A LOT OF INSTABILITY WITH THIS SYSTEM AND THEREFORE DECIDED TO LEAVE THUNDER OUT OF THE FORECAST. AS COLDER AIR BEGINS TO WORK INTO THE REGION A MIX OF PRECIPITATION PRIMARILY NW OF DAYTON WILL BE POSSIBLE LATE IN THE OVERNIGHT HOURS. TEMPERATURES ARE EXPECTED TO FALL DURING THE DAY ON WEDNESDAY. AS THEY DO RAIN WILL TRANSITION OVER TO SNOW. DURING THIS TRANSITION PERIOD...SLEET AND FREEZING RAIN WILL BE POSSIBLE. ANY ICE ACCUMULATION FROM FREEZING RAIN IS EXPECTED TO BE MINIMAL. PRECIPITATION WILL BRIEFLY TAPER DOWN DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ON WEDNESDAY HOWEVER ANOTHER WAVE OF PRECIPITATION WILL BEGIN TO WORK INTO THE REGION WEDNESDAY AFTERNOON. THIS PRECIPITATION IS EXPECTED TO BE PRIMARILY SNOW HOWEVER A WINTRY MIX WILL STILL BE POSSIBLE ACROSS PORTIONS OF NORTHERN KENTUCKY AND SE OHIO THROUGH THE AFTERNOON HOURS. PRECIPITATION WILL CHANGE OVER TO ALL SNOW WEDNESDAY EVENING. SNOW WILL CONTINUE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING BEFORE BEGINNING TO TAPER OFF. SNOW WILL BE HEAVY AT TIMES ESPECIALLY ACROSS THE SE HALF OF THE FA. THERE WILL BE A SHARP CUT OFF IN AMOUNTS FURTHER NW OF INTERSTATE 71. EXPANDED THE WINTER STORM WATCH TO COVER ALL BUT FRANKLIN INDIANA AND BUTLER COUNTY OHIO OF THE 4 INCH SNOW CRITERIA. THERE IS SOME UNCERTAINTY ON THE NW EDGE OF THE SNOW AND THEREFORE DECIDED TO LEAVE THOSE COUNTIES OUT AT THIS TIME. HAVE THE NORTHERN TIER OF THE WATCH WITH 4 TO 6 INCHES OF SNOW AND THE REST OF THE WATCH WITH AROUND 6 TO 9 INCHES OF SNOW. ISOLATED HIGHER AMOUNTS CANNOT BE RULED OUT. THERE IS STILL SOME UNCERTAINTY ON HOW QUICKLY THE RAIN WILL TRANSITION TO SNOW ON WEDNESDAY AND THUS THERE IS STILL SOME UNCERTAINTY IN FORECAST SNOW AMOUNTS. SNOW WILL MOVE OUT OF THE FA DURING THE LATE MORNING HOURS AND INTO THE AFTERNOON ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION THURSDAY NIGHT AND CLOUD COVER WILL DECREASE. ALTHOUGH SOME RETURN SOUTHERLY FLOW WILL DEVELOP...WITH FRESH SNOW COVER AND MOSTLY CLEAR SKIES EXPECT TEMPERATURES TO DROP DOWN TO THE NEGATIVE SINGLE DIGITS ACROSS MANY LOCATIONS. && .LONG TERM /FRIDAY THROUGH MONDAY/... FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES EAST WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES. MOSTLY SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING SOUTHERLY RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL GET ON FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT LINGERING SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY. WILL RANGE HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. LOWS FRIDAY NIGHT WILL GENERALLY BE IN THE TEENS. FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS. TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL STILL AVERAGE BELOW NORMAL FOR EARLY MARCH. HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE BIT BELOW NORMAL FOR EARLY MARCH. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... FREEZING RAIN AND DRIZZLE IS CURRENTLY MOVING INTO THE AREA FROM WEST TO EAST THIS MORNING WITH KDAY ALREADY REPORTING FZDZ. EXPECT LIGHT FREEZING RAIN AND DRIZZLE TO CONTINUE THIS MORNING WITH TEMPERATURES SLOWLY WARMING. LATEST HRRR MODEL RUN SHOWS THAT THERE MIGHT BE A BRIEF BREAK IN THE PRECIP THIS MORNING BUT QUICKLY REDEVELOPS PRECIP ACROSS THE AREA. GFS/ NAM AND RAP SOUNDINGS ALL SHOW TEMPERATURES RISING ABOVE FREEZING BY NOON TODAY. FORECAST SOUNDINGS ALSO SHOW CIGS FALLING INTO IFR CONDITIONS THIS AFTERNOON. LOOKING AT UPSTREAM OBS AM A LITTLE HESITANT WITH THIS. A COLD FRONT WILL THEN MOVE THROUGH THE AREA LATE TONIGHT INTO EARLY WEDNESDAY MORNING. AS THE FRONT MOVES THROUGH THE AREA MUCH COLDER AIR WILL FILTER IN. THIS WILL ALLOW PRECIP TO AGAIN TRANSITION BACK TO SNOW. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL POTENTIALLY LINGER THROUGH THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ042-051>055-060>065-070>074-077. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ026-034-035-043>046-056. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR OHZ063>065-071>074-077>082-088. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR OHZ063>065-071>074-077>082-088. FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR OHZ078>082-088. KY...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ089>100. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR KYZ089>100. FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR KYZ091>093. IN...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR INZ050-058-059-066-073-074. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR INZ073>075-080. FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR INZ075-080. FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR INZ075. && $$ SYNOPSIS...NOVAK NEAR TERM...AR SHORT TERM...NOVAK LONG TERM...HICKMAN AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
553 AM EST TUE MAR 3 2015 .SYNOPSIS... A WARM FRONT TODAY...FOLLOWED BY A COLD FRONT TONIGHT. FRONT STALLS TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT WEDNESDAY NIGHT. SNOW SHOWERS LINGER ON THURSDAY. HIGH PRESSURE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... 645 AM UPDATE... PRECIP GRADUALLY TRYING TO FILL IN UPSTREAM...BUT STILL FALLING OUT OF A MID DECK. HRRR INSISTS ON THIS EXPANDING AND REACHING THE GROUND INTO SE OH IN THE 13 TO 15Z TIME FRAME. WILL CONT HEADLINE AS IS FOR NOW. PREVIOUS DISCUSSION BELOW... A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP BREAKING OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH EXTENT OF PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A CONCERN FOR FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE VALLEYS AND HOLLOWS. AFTER COORDINATING WITH SURROUNDING OFFICES...ELECTED TO EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH AND PORTIONS OF W WV ALONG OH RIVER. LOOKING AT ONLY A FEW HUNDREDTHS AT BEST. ADJUSTED END TIMES TO REFLECT EXPECTED WARMING OF TEMPS. LEFT NE KY OUT ATTM AS CONFIDENCE NOT AS HIGH THAT PRECIP WILL BREAK OUT OVER THAT AREA BEFORE TEMPS CAN RECOVER. WILL HANDLE WITH AN SPS FOR NOW AND MONITOR TRENDS. ACROSS THE N MOUNTAINS...THERE MAY MORE IN THE WAY OF SLEET INITIALLY VS FZRA. ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS. THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z. STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD. FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE 50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA. DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR FLOODING. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MODELS ARE STILL IN DISAGREEMENT WITH HOW FAR SOUTH THE COLDER AIR WILL PUSH INTO THE REGION ON WEDNESDAY. THIS IS CRITICAL FOR THE TYPE OF PRECIPITATION THAT WILL OCCUR WEDNESDAY NIGHT WITH A WAVE MOVING ALONG THE FRONT. ALSO DUE TO THE DIFFERENCES IN THE HANDLING OF THE COLD AIR...PLACEMENT OF HIGHER PRECIPITATION AMOUNTS VARY CONSIDERABLY. THIS LEADS TO A LOW CONFIDENCE FORECAST. NAM/SREF WOULD INDICATE SNOW IN CENTRAL OHIO...WITH A LARGE BAND OF SIGNIFICANT AMOUNTS OF SLEET FROM NE KY/S OH INTO CENTRAL WV AND THE WV MOUNTAINS. GFS AND ECMWF ARE MUCH COLDER AND WOULD PRODUCE SIGNIFICANTLY MORE SNOW INSTEAD OF SLEET. IN ANY CASE...FEEL THAT A WINTER STORM WATCH IS WARRANTED AT THIS POINT...ALTHOUGH THE TYPE OF WEATHER IS UNCERTAIN. WILL NOT ISSUE FOR THE SOUTHERN COAL FIELDS AND VA HOWEVER...AS ODDS OF BEING RAIN ARE MUCH LARGER THERE...STILL CAUSING FLOODING CONCERNS. SOME UPSLOPE SNOW LOOKS TO BE A GOOD BET FOR THURSDAY AS COLD AIR MOVES IN BEHIND THE SYSTEM. WILL INCREASE POPS SOME. && .LONG TERM /FRIDAY THROUGH MONDAY/... HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES THROUGHOUT. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... 12Z TUESDAY THRU 12Z WEDNESDAY... A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA THIS MORNING...WITH VFR CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL IFR CEILINGS AND VSBY IN RAIN AND FOG ON E SLOPES. THERE MAY BE A PERIOD OF FREEZING RAIN IN THE MORNING BEFORE CHANGING TO ALL RAIN...AT HTS/PKB...BUT DURATION OF THIS PCPN WILL BE SHORT. THERE WILL BE A BREAK IN THE RAIN THIS AFTERNOON. LOOK FOR GENERAL MVFR CONDITIONS TO PREVAIL ACROSS SE OH AND POSSIBLY JUST VFR CONDITIONS IN THE WARM SECTOR ACROSS EKN AMID DOWNSLOPE WINDS. IFR CONDITIONS LOOK TO DEVELOP ON E SLOPES INCLUDING KBKW THIS AFTERNOON. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND NIGHT. THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY 09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR OR WORSE. SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE TOPS THIS MORNING...INCLUDING KBKW. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL VARY WITH ONSET OF THE RAIN TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY H H H H H H M H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H M H H H M H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H M H H H H M CKB CONSISTENCY H H H H H H M M M M H H AFTER 12Z WEDNESDAY... IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN/SLEET OR SNOW LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. IFR IN SNOW SHOWERS THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR WVZ005>011-013>020-024>040-046-047. FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR WVZ007>009-017. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR WVZ005>011-013>020-026-029. WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR WVZ027-028-030>032-035>040-046-047. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ046-047. OH...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR OHZ066-067-075-076-083>087. FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR OHZ083>087. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR OHZ066-067-075-076-083>087. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ066-067-075-076. KY...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR KYZ101>103-105. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ101>103-105. VA...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR VAZ003-004. && $$ SYNOPSIS...JS/RPY/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...JS AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
425 AM EST TUE MAR 3 2015 .SYNOPSIS... A WARM FRONT TODAY...FOLLOWED BY A COLD FRONT TONIGHT. FRONT STALLS TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT WEDNESDAY NIGHT. SNOW SHOWERS LINGER ON THURSDAY. HIGH PRESSURE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP BREAKING OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH EXTENT OF PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A CONCERN FOR FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE VALLEYS AND HOLLOWS. AFTER COORDINATING WITH SURROUNDING OFFICES...ELECTED TO EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH AND PORTIONS OF W WV ALONG OH RIVER. LOOKING AT ONLY A FEW HUNDREDTHS AT BEST. ADJUSTED END TIMES TO REFLECT EXPECTED WARMING OF TEMPS. LEFT NE KY OUT ATTM AS CONFIDENCE NOT AS HIGH THAT PRECIP WILL BREAK OUT OVER THAT AREA BEFORE TEMPS CAN RECOVER. WILL HANDLE WITH AN SPS FOR NOW AND MONITOR TRENDS. ACROSS THE N MOUNTAINS...THERE MAY MORE IN THE WAY OF SLEET INITIALLY VS FZRA. ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS. THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z. STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD. FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE 50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA. DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR FLOODING. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MODELS ARE STILL IN DISAGREEMENT WITH HOW FAR SOUTH THE COLDER AIR WILL PUSH INTO THE REGION ON WEDNESDAY. THIS IS CRITICAL FOR THE TYPE OF PRECIPITATION THAT WILL OCCUR WEDNESDAY NIGHT WITH A WAVE MOVING ALONG THE FRONT. ALSO DUE TO THE DIFFERENCES IN THE HANDLING OF THE COLD AIR...PLACEMENT OF HIGHER PRECIPITATION AMOUNTS VARY CONSIDERABLY. THIS LEADS TO A LOW CONFIDENCE FORECAST. NAM/SREF WOULD INDICATE SNOW IN CENTRAL OHIO...WITH A LARGE BAND OF SIGNIFICANT AMOUNTS OF SLEET FROM NE KY/S OH INTO CENTRAL WV AND THE WV MOUNTAINS. GFS AND ECMWF ARE MUCH COLDER AND WOULD PRODUCE SIGNIFICANTLY MORE SNOW INSTEAD OF SLEET. IN ANY CASE...FEEL THAT A WINTER STORM WATCH IS WARRANTED AT THIS POINT...ALTHOUGH THE TYPE OF WEATHER IS UNCERTAIN. WILL NOT ISSUE FOR THE SOUTHERN COAL FIELDS AND VA HOWEVER...AS ODDS OF BEING RAIN ARE MUCH LARGER THERE...STILL CAUSING FLOODING CONCERNS. SOME UPSLOPE SNOW LOOKS TO BE A GOOD BET FOR THURSDAY AS COLD AIR MOVES IN BEHIND THE SYSTEM. WILL INCREASE POPS SOME. && .LONG TERM /FRIDAY THROUGH MONDAY/... HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES THROUGHOUT. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... 06Z TUESDAY THRU 06Z WEDNESDAY... A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA THIS MORNING...WITH VFR CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL IFR CEILINGS AND VSBY IN RAIN AND FOG. THERE MAY BE A PERIOD OF FREEZING RAIN IN THE MORNING BEFORE CHANGING TO ALL RAIN...ESPECIALLY AT HTS/BKW/PKB...BUT DURATION OF THIS PCPN WILL BE SHORT. THERE MAY BE A BREAK IN THE RAIN THIS AFTERNOON NIGHT...MAINLY SE PORTION...LOOK FOR GENERAL MVFR CONDITIONS TO PREVAIL ACROSS SE OH AND POSSIBLY JUST VFR CONDITIONS IN THE WARM SECTOR ACROSS CRW/EKN/CKB. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND NIGHT. THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY 09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR. SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE TOPS THIS MORNING...INCLUDING KBKW. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL VARY WITH ONSET OF THE RAIN TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE TUE 03/03/15 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY H H H H H H H M M M H H HTS CONSISTENCY H H H H H H H M H H H H BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H M M H H CKB CONSISTENCY H H H H H H H H H M M M AFTER 06Z WEDNESDAY... IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN/SLEET OR SNOW LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. IFR IN SNOW SHOWERS THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR WVZ005>011-013>020-024>040-046-047. FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR WVZ007>009-017. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR WVZ005>011-013>020-026-029. WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR WVZ027-028-030>032-035>040-046-047. FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR WVZ046-047. OH...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR OHZ066-067-075-076-083>087. FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR OHZ083>087. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR OHZ066-067-075-076-083>087. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ066-067-075-076. KY...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR KYZ101>103-105. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR KYZ101>103-105. VA...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR VAZ003-004. && $$ SYNOPSIS...JS/RPY/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...JS AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
310 AM EST TUE MAR 3 2015 .SYNOPSIS... A WARM FRONT TODAY...FOLLOWED BY A COLD FRONT TONIGHT. FRONT STALLS TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT WEDNESDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP BREAKING OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH EXTENT OF PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A CONCERN FOR FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE VALLEYS AND HOLLOWS. AFTER COORDINATING WITH SURROUNDING OFFICES...ELECTED TO EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH AND PORTIONS OF W WV ALONG OH RIVER. LOOKING AT ONLY A FEW HUNDREDTHS AT BEST. ADJUSTED END TIMES TO REFLECT EXPECTED WARMING OF TEMPS. LEFT NE KY OUT ATTM AS CONFIDENCE NOT AS HIGH THAT PRECIP WILL BREAK OUT OVER THAT AREA BEFORE TEMPS CAN RECOVER. WILL HANDLE WITH AN SPS FOR NOW AND MONITOR TRENDS. ACROSS THE N MOUNTAINS...THERE MAY MORE IN THE WAY OF SLEET INITIALLY VS FZRA. ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS. THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z. STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD. FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE 50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA. DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR FLOODING. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A SIGNIFICANT SYSTEM WILL IMPACT THE AREA WEDNESDAY AND THURSDAY. A FRONTAL BOUNDARY STALLS OVER THE FORECAST AREA ON WEDNESDAY AND WILL BRING COPIOUS AMOUNTS OF PRECIPITATION...ON THE ORDER OF 2 TO 3 INCHES IN MOST PLACES. THIS FORECAST IS STILL LIKELY UNDERESTIMATING THE TOTAL ACCUMULATION SPIT OUT BY THE MODELS OF 3 TO 4 INCHES. THE LARGE AMOUNTS OF RAIN...WARM TEMPERATURES...HIGH DEW POINTS AND STRONG 850 MB WINDS WILL PROVIDE IDEAL CONDITIONS FOR MELTING THE CURRENT SNOWPACK ADDING ADDITIONAL MOISTURE AVAILABLE FOR RUNOFF HENCE WE RAISED A FLOOD WATCH FOR OUR ENTIRE FORECAST AREA. TO ADD FUEL TO THE FIRE...A SHARP COLD AIR MASS WILL INFILTRATE THE REGION ON THURSDAY TURNING THE RAIN TO SNOW. DEPENDING ON HOW FAST THIS COLD AIR PROPAGATES TO THE SOUTH WILL DICTATE HOW MUCH SNOW WE GET. RIGHT NOW...THE FORECAST IS FOR ABOUT 5-7 INCHES OVER MUCH OF OUR AREA...AND THIS MAY BE A CONSERVATIVE AMOUNT AS WELL. WHEN THE PRECIPITATION FINALLY DOES SHUT OFF...SOME OF OUR MODELS ARE CALLING FOR SURFACE TEMPERATURES OF -20 F YET AGAIN. WE ARE IN FOR A WILD RIDE OF WEATHER FOR THE NEXT SEVERAL DAYS. && .LONG TERM /FRIDAY THROUGH MONDAY/... HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES THROUGHOUT. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... 06Z TUESDAY THRU 06Z WEDNESDAY... A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA THIS MORNING...WITH VFR CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL IFR CEILINGS AND VSBY IN RAIN AND FOG. THERE MAY BE A PERIOD OF FREEZING RAIN IN THE MORNING BEFORE CHANGING TO ALL RAIN...ESPECIALLY AT HTS/BKW/PKB...BUT DURATION OF THIS PCPN WILL BE SHORT. THERE MAY BE A BREAK IN THE RAIN THIS AFTERNOON NIGHT...MAINLY SE PORTION...LOOK FOR GENERAL MVFR CONDITIONS TO PREVAIL ACROSS SE OH AND POSSIBLY JUST VFR CONDITIONS IN THE WARM SECTOR ACROSS CRW/EKN/CKB. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND NIGHT. THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY 09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR. SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE TOPS THIS MORNING...INCLUDING KBKW. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL VARY WITH ONSET OF THE RAIN TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE TUE 03/03/15 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY H H H H H H H M M M H H HTS CONSISTENCY H H H H H H H M H H H H BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H M M H H CKB CONSISTENCY H H H H H H H H H M M M AFTER 06Z WEDNESDAY... IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN OR SNOW WEDNESDAY/WEDNESDAY NIGHT. IFR IN SNOW SHOWERS THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR WVZ005>011-013>020-024>040-046-047. FREEZING RAIN ADVISORY FROM 7 AM TO 10 AM EST THIS MORNING FOR WVZ007>009-017. FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR WVZ046-047. OH...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR OHZ066-067-075-076-083>087. FREEZING RAIN ADVISORY FROM 7 AM TO 10 AM EST THIS MORNING FOR OHZ083>087. FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR OHZ066-067-075-076. KY...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR KYZ101>103-105. VA...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR VAZ003-004. && $$ SYNOPSIS...JS/RPY/30 NEAR TERM...30 SHORT TERM...JW LONG TERM...JS AVIATION...30
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
100 AM EST TUE MAR 3 2015 .SYNOPSIS... MOISTURE BEING LIFTED UP AND OVER RETREATING COLD AIR WILL BRING AREAS OF FREEZING RAIN...POSSIBLY MIXED WITH SLEET...ACROSS MOST OF THE AREA TUESDAY MORNING BEFORE CHANGING TO RAIN BY TUESDAY AFTERNOON AS TEMPERATURES WARM. LATER TUESDAY AFTERNOON...MODERATE RAIN WILL DEVELOP AND SPREAD ACROSS MUCH OF THE AREA...BUT ESPECIALLY NORTHERN KENTUCKY AND SOUTHERN OHIO WHERE LOCALLY HEAVY RAIN WILL BE POSSIBLE. THE COMBINATION OF RAIN AND MELTING SNOW MAY CAUSE FLOODING. AS COLDER AIR MOVES INTO THE AREA WEDNESDAY AFTERNOON...RAIN WILL CHANGE TO SNOW AND A PERIOD OF HEAVY SNOW IS POSSIBLE FOR NORTHERN KENTUCKY AND SOUTHERN OHIO. THE ENTIRE SYSTEM SHIFTS EAST OF THE AREA BY THURSDAY AFTERNOON WITH DRYING CONDITIONS FOR THE END OF THE WEEK AND INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... ONLY SOME TWEAKS TO THE FORECAST FOR TONIGHT. THE BIGGEST CHANGE IS THAT TEMPERATURES OVER PORTIONS OF THE NORTHERN COUNTIES HAVE FALLEN RAPIDLY UNDER THE MOSTLY CLEAR SKIES. SO ADJUSTED THEIR LOWS DOWN...BUT THE TEMPERATURES SHOULD BEGIN TO RISE ACROSS THE ENTIRE FA AFTER MIDNIGHT. THE SECOND AND MORE MINOR CHANGE HAS TO DO WITH POPS. LATEST NAM IS SLOWER IN BRINGING IN PCPN TUESDAY MORNING. THE RAP AND THE HRRR LIFT A LIGHT BAND ACROSS PORTIONS OF THE FA BETWEEN 12Z-15Z THEN PRETTY MUCH LEAVE THE REST OF THE FA DRY THRU 15Z. BACKED OFF ON THE BEGINNING OF THE POPS BY AN HOUR OR TWO...BUT DIDNT GO AS DRASTIC AS THE RAP/HRRR WITH THIS UPDATE. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... NOT TOO MANY TIMES DO WE ISSUE BACK TO BACK TO BACK ADVISORY/WATCH PRODUCTS BUT THE PATTERN NECESSITATES IT TO RAISE AWARENESS FOR MULTIPLE THREATS BEGINNING TUES A.M. AND CONTINUING INTO EARLY THURSDAY. FIRST OFF...THE TUESDAY MORNING FREEZING RAIN/SLEET POTENTIAL. THIS IS NOT AS CLEAR CUT AS ORIGINALLY THOUGHT. VERY CLEAR PER 02.12Z GUIDANCE THAT VERY STRONG MOISTURE FLUX/TRANSPORT WILL GET GOING AFTER MIDNIGHT TONIGHT TO OUR SOUTHWEST...WITH SREF 850MB TRANSPORT MAGNITUDES OF 5+ SIGMA ABOVE CLIMO AS LOW LEVEL JET RAMPS UP DOWNSTREAM OF APPROACHING NRN STREAM TROUGH SLIPPING THRU THE UPPER MS VALLEY. HOWEVER...AMBIENT AIRMASS /ESP BELOW 500 MB/ IS EXTREMELY DRY PER 02.12Z KILN SOUNDING AND FORECAST SOUNDINGS THROUGH MON NIGHT. MODEL QPFS HAVE BEEN TRENDING LIGHTER/DRIER IN THE TUESDAY MORNING TIME FRAME WHICH IS WORRISOME...BUT HAVE ALSO SEEN TIME AND TIME AGAIN WHERE STRONG WAA/MOISTURE TRANSPORT/ISENTROPIC LIFT SIGNALS USE MOISTURE EFFICIENTLY TO WRING OUT LIGHT QPF OVER RETREATING ARCTIC DOMES. THUS...AM RUNNING WITH HIGHER PRECIP CHANCES THAN MDLS ON TUES MORNING IN THIS SCENARIO GIVEN THE VERY STRONG TRANSPORT SIGNAL AND RETREATING ARCTIC DOME. NOT ONLY IS THERE THAT ASPECT...BUT BOUNDARY LAYER WARMING WILL BE RACING NORTH ON DEVELOPING SSELY FLOW. CURRENT FORECAST IS BEST CURRENT ESTIMATION OF OVERLAP BETWEEN ADVANCING AREAS OF LIGHT RAIN...INCREASING BOUNDARY LAYER WARMING...AND TIMING OF THE TWO...WHICH SPELLS A TWO TO FIVE HOUR PERIOD /LEAST IN THE SOUTH AND MORE IN THE NORTH/ OF LIGHT FREEZING RAIN POTENTIAL. GIVEN VIRTUALLY NO IMPACT OR CHANCE TO MIX WITH SLEET ACROSS SERN IND/SWRN OH/CNTL OH...HAVE OPTED FOR FREEZING RAIN ADVISORY HERE FOR LIGHT ICE AMOUNTS THAT MAY CAUSE TRAVEL ISSUES. FURTHER NORTH...DEPTH OF COLD AIR AND PERHAPS A LITTLE LONGER DURATION MAY ALLOW FOR MORE FZRA/SLEET COMBO SO WINTER WX ADVISORY THERE. TOO MUCH RISK TO LET THIS SITUATION GO WITHOUT AN ADVISORY AS MAGNITUDE OF WARMING/MOISTENING ALOFT MAY ALLOW FOR A MORE RAPID DEVELOPMENT AND BETTER COVERAGE THAN MODELS ARE SHOWING. THE DIFFERENCE BETWEEN 02.12Z NAM/ECMWF /MEAGER ON QPF AND COVERAGE/ TO 02.12Z SREF /HIGH PROBABILITIES OF NOT ONLY MEASURABLE FZRA BUT SOME HINTS OF UP TO 0.10"/ SPURRED THE DECISION TO MOVE TO ADVISORY ON THIS ISSUANCE. NEXT UP...MODERATE TO HEAVY RAIN AND POTENTIAL FLOODING. THIS SIGNAL HAS BEEN VERY LONG ADVERTISED PER ANALOGS AND ANOMALIES...AND NOW IT/S TIME TO SWITCH HIGHER RES DETERMINISTIC GUIDANCE FOR DETAILS. THE PATTERN SUPPORTS A CONTINUED LONG FEED OF MOISTURE TRANSPORT ALONG AND AHEAD OF A SLOWLY MOVING FRONTAL ZONE TUESDAY AFTERNOON INTO WEDNESDAY MORNING. BIG PUSH OF VERY ANOMALOUS/DEEP MOISTURE...WITH PWAT RUNNING 300% NORMAL AND 3 SIGMA ABOVE CLIMO ON TUESDAY NIGHT. 70+KT LOW LEVEL JET AROUND BACKSIDE OF SERN CONUS RIDGING SHOULD FOCUS/FUNNEL MOISTURE INTO THE OHIO VALLEY AND IT SEEMS POTENTIAL FOR EXCESSIVE RAIN IS SHIFTING A TAD SOUTH W/TIME OVER THE LAST 24 HOURS. CURRENTLY EXPECT THE HEAVIEST RAINFALL FOOTPRINT /VIA LONG DURATION TRAIN OF MODERATE/SOMETIMES HEAVY RAIN/ TO BE ALONG AND SOUTH/EAST OF I-71 WHICH IS WHERE FLOOD WATCH HAS BEEN PLACED. PLENTY OF SNOW/FROZEN SOILS TO CONTEND WITH SO STRAIGHTFORWARD TO GET FLOOD WATCH OUT TODAY. AMTS FROM 1-2" - AND WHILE CONVECTION ISN/T GOING TO PLAY A HUGE ROLE - CONVECTIVE ELEMENTS VIA MODEST DESTABILIZATION ABOVE THE STABLE BOUNDARY LAYER WILL CERTAINLY CAUSE CONCERN...ESPECIALLY SOUTH/SOUTHEAST CWA IN NORTHERN KY/SCNTL OH. COULD SEE BRUSH CREEK BASIN...LOWER SCIOTO...AND KENTUCKY/LICKING RIVERS IN KY REALLY RESPOND TO THIS...AS 0.5" TO 1.00" SNOW WATER EQUIVALENT TIED UP IN THE SNOW PACK IS RELEASED RATHER QUICKLY WITH TEMPS APPROACHING 50F IN THE SOUTH. AM A LITTLE MORE THAN CONCERNED FOR NRN KY/FAR SCNTL OHIO SO HOPING FOR A SLOW RELEASE FROM THE SNOW PACK AND RAIN AMOUNTS ON THE LIGHTER END OF THE SPECTRUM. FINALLY...POTENTIAL WINTER STORM. LOW CONFIDENCE HERE BUT A SIGNAL I COULD NOT IGNORE. 02.12Z MODELS CONTINUE TO STABILIZE SOMEWHAT ON COLD AIR OOZING INTO THE FRONTOGENETICALLY FORCED PCPN REGION THAT WILL BE ONGOING ACROSS NRN KY/SRN OH. 02.12Z GFS AND ITS PRIOR RUNS SEEMED WAY TOO COLD IN THE BOUNDARY LAYER AND THROWN OUT. MUCH MORE CONSISTENCY FROM NAM/ECMWF AND THAT IS WHERE FORECAST IS BASED. A LONG DURATION RIGHT ENTRANCE REGION OF THE JET/FGEN FORCED BAND OF PRECIPITATION WILL CONTINUE WED AFTN/NIGHT INTO THURSDAY MORNING AS THE COLD AIR OVERTAKES IT. THERE/S A SCENARIO /ONE OF SEVERAL/ WHERE 12-18 HOURS OF MODERATE SNOW OCCURS FROM NRN KY INTO SRN OHIO...AND SOME SOLUTIONS ARE EXTREME IN SNOWFALL AMOUNTS. ANECDOTALLY...HAVE TO ACKNOWLEDGE THAT THE PATTERN AND FORCING SUPPORTS A POTENTIAL HIGHER-END SNOW ACCUMULATION. BUT USING CLIMO AND WHAT WILL LIKELY BE A SLOWER TRANSITION TO SNOW...AND MARCH INSOLATION /EVEN THRU CLOUDS/ THAT WILL KEEP ANYTHING BUT HEAVY SNOW RATES FROM ACCUMULATING TOO MUCH. IT/S WEDNESDAY NIGHT THAT HAS MY ATTENTION AS A POSSIBILITY OF REALLY ACCUMULATING SNOW UNDER CLOAK OF DARKNESS WITH CONTINUED BANDING/FGEN FORCING IN THE RIGHT ENTRANCE REGION OF THE JET THAT MOVES ONLY VERY SLOWLY SOUTHEAST FROM WED AFTN INTO THURS MORNING. WILL HAVE TO WATCH AREAS BACK FROM CVG TO ILN TO SOUTH OF CMH FOR POSSIBLE EXPANSION OF WATCH IF SOME OF THE MORE DIRE /QUICKER CHANGEOVER/ SITUATIONS GET MORE SUPPORT IN THE ENSEMBLES. HAVE TAKEN A VERY CONSERVATIVE APPROACH TO SNOWFALL FORECAST IN OUR SOUTHERN AREAS AND CURRENTLY INDICATING 4-7" WHICH NECESSITATES A WATCH CENTERED ON WED NIGHT...AGAIN...WITH NEED TO WATCH THAT THIS MAY GET EXPANDED IN TIME. && .LONG TERM /THURSDAY THROUGH MONDAY/... ANOTHER ROUND OF COLD ARCTIC AIR IS ON TAP FOR THURSDAY AS ARCTIC HIGH PRESSURE BUILDS EAST INTO THE REGION. TEMPERATURES WILL STRUGGLE TO WARM INTO THE MID TEENS NORTH TO THE MID 20S SOUTH. THESE TEMPERATURES ARE SOME 25 TO 30 DEGREES BELOW NORMAL FOR EARLY MARCH. NEEDLESS TO SAY...SOME RECORD LOW MAX TEMPERATURES MAY BE IN JEOPARDY. THEY ARE 24...22...AND 20 AT CVG...DAY...AND CMH RESPECTIVELY. WE ARE CURRENTLY FORECASTING 21...17...AND 19 AT CVG...DAY...AND CMH RESPECTIVELY. WHO HAS FRESH SNOW COVER...AND THE AMOUNT OF CLOUDS...WILL ULTIMATELY PLAY A ROLE ON HOW WARM IT GETS DESPITE AN INCREASING SUN ANGLE FOR EARLY MARCH. FOR THURSDAY NIGHT...THE ARCTIC HIGH WILL MOVE EAST ACROSS THE OHIO VALLEY. AT THIS TIME...THE BEST CHANCE FOR WINDS TO BECOME LIGHT OR CALM WILL BE ALONG AND SOUTH OF THE OHIO RIVER. WITH CLEAR SKIES EXPECTED...TEMPERATURES WILL LIKELY DROP BELOW ZERO IN MOST SPOTS. AGAIN...KNOWING HOW COLD IT WILL GET ATTM IS DIFFICULT WHICH WILL DEPEND ON SNOW COVER AND HOW DEEP THAT SNOW COVER IS FOR MAXIMUM RADIATIONAL COOLING EFFECTS. HAVE GONE CONSERVATIVE ATTM...BUT GETTING LOWER THAN WHAT IS FORECAST IS CERTAINLY POSSIBLE. WILL FORECAST LOWS GENERALLY IN THE ZERO TO 5 BELOW RANGE. RECORD LOWS OF 2...0 AND 2 AT CVG...DAY AND CMH WILL ALSO BE IN JEOPARDY. FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES EAST WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES. MOSTLY SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING SOUTHERLY RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL GET ON FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT LINGERING SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY. WILL RANGE HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. LOWS FRIDAY NIGHT WILL GENERALLY BE IN THE TEENS. FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS. TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL STILL AVERAGE BELOW NORMAL FOR EARLY MARCH. HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE BIT BELOW NORMAL FOR EARLY MARCH. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS ARE EXPECTED FOR THE EARLY PART OF THE TAF PERIOD. HOWEVER A BAND LIGHT PRECIPITATION WILL SPREAD ACROSS THE TERMINALS AFTER 09Z. EXPECT THIS TO BE FREEZING RAIN WITH LIGHT ICE ACCUMULATIONS. AT THIS POINT EXPECT THE BAND TO MOVE THROUGH ANY ONE SPOT WITHIN THREE HOURS. APPEARS THAT THERE WILL BE A LULL IN PRECIPITATION WITH TEMPERATURES WARMING ABOVE FREEZING BEFORE ANY THING ELSE DEVELOPS. HOWEVER CEILINGS WILL BE DROPPING TO MVFR AS THE INITIAL PRECIPITATION PULLS OUT. WINDS WILL BE VEERING TO THE SOUTH AND SLOWLY STRENGTHENING. SHOWERS WILL DEVELOP AROUND/AFTER 18Z. CONDITIONS SHOULD REMAIN MVFR BUT THERE COULD BE SOME BRIEF DROPS TO IFR PARTICULARLY IN ANY HEAVIER SHOWERS. EVOLUTION OF PRECIPITATION BECOMES MORE UNCERTAIN FURTHER OUT IN TIME. PRECIPITATION MAY BECOME MORE WIDESPREAD AS A COLD FRONT SAGS INTO THE AREA...ESPECIALLY FOR THE CINCINNATI SITES AS WELL AS KILN. WHERE THIS OCCURS IFR CONDITIONS WILL BECOME MORE PREVALENT. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL POTENTIALLY LINGER THROUGH THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR OHZ053>055-060>065-070>072-074-077. WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR OHZ026-034-035-042>046-051-052-056. FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR OHZ063>065-071>074-077>082-088. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR OHZ081-088. KY...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR KYZ089>100. WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR KYZ089-090-094>100. IN...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR INZ058-059-066-073-074. WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR INZ050. FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR INZ075-080. && $$ SYNOPSIS...BINAU NEAR TERM...SITES SHORT TERM...BINAU LONG TERM...HICKMAN AVIATION...
AREA FORECAST DISCUSSION
NWS PENDLETON OR
523 PM PST MON MAR 2 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM...ISSUED AN EARLY FORECAST UPDATE THIS EVENING TO PLACE THE ENTIRE FORECAST AREA UNDER AT LEAST A SLIGHT CHANCE OF SHOWERS THROUGH THE EVENING. RADAR AND SATELLITE ARE SHOWING ISOLATED TO SCATTERED SHOWERS ACROSS THE FORECAST AREA UNDER THIS NORTHERLY FLOW. NORTHEAST OREGON CONTINUES TO HAVE THE BEST CHANCE OF SHOWERS ESPECIALLY OVER THE HIGHER TERRAIN AND WALLOWA COUNTY. THESE AREAS COULD SEE 1 TO 3 INCHES OF SNOW OVERNIGHT. REST OF THE FORECAST AREA WILL SEE LITTLE TO NO ACCUMULATIONS. SHOWERS WILL BE ON THE DECREASE AFTER MIDNIGHT. .AVIATION...VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS. THERE WILL BE SOME SCT-BKN CLOUDS 060-080 MAINLY IMPACTING KRDM AND KBDN OTHERWISE CLEARING SKIES FOR OTHER SITES. THERE WILL BE SOME NORTH WINDS 10-20 KNOTS AT KPSC OVERNIGHT DECREASING LATE OTHERWISE EXPECTING MAINLY LESS THAN 10 KNOTS. && .PREV DISC... /ISSUED 230 PM PST MON MAR 2 2015/ SHORT TERM...TONIGHT THROUGH THURSDAY. THE TAIL END OF A BACKDOOR COLD FRONT IS MAKING ITS WAY ACROSS EASTERN WASHINGTON AND NORTHEAST OREGON. DOPPLER RADAR AT SPOKANE IS SHOWING A WIDE SWATH OF WEAK RETURNS (LESS THAN 20 DBZ). LATEST HRRR KEEP REFLECTIVITIES THIS LOW THROUGH EARLY TUESDAY MORNING WITH 12-HOUR QPF AMOUNTS LESS THAN A TENTH OVER MOST OF THE AREA. THIS INCREASES CONFIDENCE THAT ANY SNOWFALL TONIGHT WILL BE LIGHT AND MAINLY ISOLATED TO SCATTERED OROGRAPHIC SHOWERS. THE ONE EXCEPTION WILL BE OVER THE WALLOWA MOUNTAINS WHERE A NORTHERLY FLOW ALOFT AND MOISTURE WILL BRING 3-6 INCHES OF SNOW IN THE HIGHER TERRAIN. THE WALLOWA VALLEY...IMNAHA VALLEY...AND THE NORTHERN PLATEAU OF WALLOWA COUNTY WILL LIKELY RECEIVE 1-3 INCHES OVERNIGHT DUE TO THE 20:1 SNOW-TO-LIQUID RATIO AND LOW LEVEL UPSLOPE. PRECIPITATION WILL TAPER OFF TONIGHT AND EARLY TUESDAY MORNING. A DRY NORTHERLY FLOW ALOFT FOLLOWING THE SYSTEM WILL CAUSE OVERNIGHT TEMPERATURES TONIGHT TO FALL INTO THE TEENS AND 20S...AND SINGLE DIGITS AND TEENS TUESDAY NIGHT. IT WILL BE BREEZY TONIGHT IN THE LOWER COLUMBIA BASIN RESULTING IN WIND CHILLS IN THE TEENS. A FEW LOCATIONS MAY BEAT THEIR RECORD LOWS FOR TUESDAY NIGHT. A DRY FORECAST IS IN STORE TUESDAY AFTERNOON THROUGH THURSDAY. A WARMING TREND BEGINS WEDNESDAY AS HIGH PRESSURE ALOFT BUILDS. AFTERNOON TEMPERATURES WILL CLIMB INTO THE 50S ACROSS THE REGION ON THURSDAY--ABOUT 5 DEGREES ABOVE SEASONAL AVERAGE. WISTER LONG TERM...THURSDAY NIGHT THROUGH MONDAY. TOWARD THE END OF THE WEEK A DISTURBANCE WILL PASS TO THE NORTH OF THE AREA AS STRONG HIGH PRESSURE DOMINATES OUR WEATHER INTO THE WEEKEND WITH DRY CONDITIONS. AFTERNOON TEMPERATURES ARE FORECAST TO CLIMB ABOVE NORMAL AND INTO THE 60S ACROSS SOME LOCATIONS BY THE WEEKEND. AVIATION...LCL MVFR CEILINGS WILL PERSIST INTO THIS EVENING AS A DISTURBANCE MOVES THROUGH THE REGION. WNW SFC WINDS WILL SHIFT TO THE NORTH THAT WILL USHER SOME COLDER AIR INTO THE REGION TONIGHT. DECREASING CLOUDS WILL ACCOMPANY THE COLDER AIR AND A RETURN TO VFR CONDITIONS ARE EXPECTED AFTER 02Z EXCEPT AFTER 06Z ALONG THE FOOTHILLS OF THE BLUE MOUNTAINS THAT INCLUDES TAF SITES KPDT AND KALW. THE VFR CONDITIONS WILL CONTINUE INTO TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... PDT 23 43 19 50 / 20 0 0 0 ALW 27 44 24 53 / 20 0 0 0 PSC 23 48 18 52 / 20 0 0 0 YKM 25 46 21 51 / 20 0 0 0 HRI 22 47 18 53 / 20 0 0 0 ELN 23 48 19 51 / 20 0 0 0 RDM 16 45 12 52 / 20 0 0 0 LGD 22 40 13 47 / 20 10 0 0 GCD 20 41 15 50 / 20 10 0 0 DLS 28 52 24 57 / 20 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 91/91/91
AREA FORECAST DISCUSSION
NWS PENDLETON OR
924 PM PST MON MAR 2 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM...ISSUED AN EARLY FORECAST UPDATE THIS EVENING TO PLACE THE ENTIRE FORECAST AREA UNDER AT LEAST A SLIGHT CHANCE OF SHOWERS THROUGH THE EVENING. RADAR AND SATELLITE ARE SHOWING ISOLATED TO SCATTERED SHOWERS ACROSS THE FORECAST AREA UNDER THIS NORTHERLY FLOW. NORTHEAST OREGON CONTINUES TO HAVE THE BEST CHANCE OF SHOWERS ESPECIALLY OVER THE HIGHER TERRAIN AND WALLOWA COUNTY. THESE AREAS COULD SEE 1 TO 3 INCHES OF SNOW OVERNIGHT. REST OF THE FORECAST AREA WILL SEE LITTLE TO NO ACCUMULATIONS. SHOWERS WILL BE ON THE DECREASE AFTER MIDNIGHT. .AVIATION...VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS. THERE WILL BE SOME SCT-BKN CLOUDS 060-080 MAINLY IMPACTING KRDM AND KBDN OTHERWISE CLEARING SKIES FOR OTHER SITES. THERE WILL BE SOME NORTH WINDS 10-20 KNOTS AT KPSC OVERNIGHT DECREASING LATE OTHERWISE EXPECTING MAINLY LESS THAN 10 KNOTS. && .PREV DISC... /ISSUED 230 PM PST MON MAR 2 2015/ SHORT TERM...TONIGHT THROUGH THURSDAY. THE TAIL END OF A BACKDOOR COLD FRONT IS MAKING ITS WAY ACROSS EASTERN WASHINGTON AND NORTHEAST OREGON. DOPPLER RADAR AT SPOKANE IS SHOWING A WIDE SWATH OF WEAK RETURNS (LESS THAN 20 DBZ). LATEST HRRR KEEP REFLECTIVITIES THIS LOW THROUGH EARLY TUESDAY MORNING WITH 12-HOUR QPF AMOUNTS LESS THAN A TENTH OVER MOST OF THE AREA. THIS INCREASES CONFIDENCE THAT ANY SNOWFALL TONIGHT WILL BE LIGHT AND MAINLY ISOLATED TO SCATTERED OROGRAPHIC SHOWERS. THE ONE EXCEPTION WILL BE OVER THE WALLOWA MOUNTAINS WHERE A NORTHERLY FLOW ALOFT AND MOISTURE WILL BRING 3-6 INCHES OF SNOW IN THE HIGHER TERRAIN. THE WALLOWA VALLEY...IMNAHA VALLEY...AND THE NORTHERN PLATEAU OF WALLOWA COUNTY WILL LIKELY RECEIVE 1-3 INCHES OVERNIGHT DUE TO THE 20:1 SNOW-TO-LIQUID RATIO AND LOW LEVEL UPSLOPE. PRECIPITATION WILL TAPER OFF TONIGHT AND EARLY TUESDAY MORNING. A DRY NORTHERLY FLOW ALOFT FOLLOWING THE SYSTEM WILL CAUSE OVERNIGHT TEMPERATURES TONIGHT TO FALL INTO THE TEENS AND 20S...AND SINGLE DIGITS AND TEENS TUESDAY NIGHT. IT WILL BE BREEZY TONIGHT IN THE LOWER COLUMBIA BASIN RESULTING IN WIND CHILLS IN THE TEENS. A FEW LOCATIONS MAY BEAT THEIR RECORD LOWS FOR TUESDAY NIGHT. A DRY FORECAST IS IN STORE TUESDAY AFTERNOON THROUGH THURSDAY. A WARMING TREND BEGINS WEDNESDAY AS HIGH PRESSURE ALOFT BUILDS. AFTERNOON TEMPERATURES WILL CLIMB INTO THE 50S ACROSS THE REGION ON THURSDAY--ABOUT 5 DEGREES ABOVE SEASONAL AVERAGE. WISTER LONG TERM...THURSDAY NIGHT THROUGH MONDAY. TOWARD THE END OF THE WEEK A DISTURBANCE WILL PASS TO THE NORTH OF THE AREA AS STRONG HIGH PRESSURE DOMINATES OUR WEATHER INTO THE WEEKEND WITH DRY CONDITIONS. AFTERNOON TEMPERATURES ARE FORECAST TO CLIMB ABOVE NORMAL AND INTO THE 60S ACROSS SOME LOCATIONS BY THE WEEKEND. AVIATION...LCL MVFR CEILINGS WILL PERSIST INTO THIS EVENING AS A DISTURBANCE MOVES THROUGH THE REGION. WNW SFC WINDS WILL SHIFT TO THE NORTH THAT WILL USHER SOME COLDER AIR INTO THE REGION TONIGHT. DECREASING CLOUDS WILL ACCOMPANY THE COLDER AIR AND A RETURN TO VFR CONDITIONS ARE EXPECTED AFTER 02Z EXCEPT AFTER 06Z ALONG THE FOOTHILLS OF THE BLUE MOUNTAINS THAT INCLUDES TAF SITES KPDT AND KALW. THE VFR CONDITIONS WILL CONTINUE INTO TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... PDT 23 43 19 50 / 20 0 0 0 ALW 27 44 24 53 / 20 0 0 0 PSC 23 48 18 52 / 20 0 0 0 YKM 25 46 21 51 / 20 0 0 0 HRI 22 47 18 53 / 20 0 0 0 ELN 23 48 19 51 / 20 0 0 0 RDM 16 45 12 52 / 20 0 0 0 LGD 22 40 13 47 / 20 10 0 0 GCD 20 41 15 50 / 20 10 0 0 DLS 28 52 24 57 / 20 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 91/91/91
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
959 PM EST WED MAR 4 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA THIS EVENING AND EARLY THURSDAY. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WATER VAPOR/SATL DERIVED PWAT IMAGERY SHOWING AN ATMOSPHERIC RIVER OF ANOMALOUS PWATS EXTENDING FROM THE S PACIFIC OCEAN NEWRD INTO THE MISS VALLEY AND EVENTUALLY PA. THIS DEEP MOISTURE PLUME IS OVERRUNNING AN EXPANSIVE ARCTIC HIGH PRES TO THE NORTH...CREATING A BAND OF MIXED PRECIP FROM THE PLAINS INTO SOUTHERN PA. AS OF 02Z...PTYPE IS LGT RAIN ACROSS MOST OF SOUTHERN PA. HOWEVER...THE HIGHER TERRAIN FROM KFIG/KUNV SOUTH THRU KJST IS NOW REPORTING SNOW. AS WEAK WAVE OF LOW PRES PASSES SOUTH OF PA OVERNIGHT...PRECIP WILL EXPAND NORTH ACROSS THE STATE...WHILE COLDER AIR FILTERS IN ON NW FLOW. ALL LATEST MDL DATA POINTING TOWARD A GENERAL 2-4 INCH SNOWFALL ACROSS THE SOUTHERN COUNTIES OVERNIGHT...WITH PERHAPS A FEW AMTS NR 6 ALONG THE MD BORDER. 18Z MDL SOUNDINGS AND LATEST HRRR OUTPUT BOTH INDICATE THERMAL PROFILES WILL REMAIN TOO WARM FOR SNOW ACROSS THE LOWER SUSQ VALLEY UNTIL ARND 06Z. THUS...HAVE WILL LOWER AMTS THERE. TEMPERATURES AT 02Z RUNNING FROM THE U20S ACROSS THE NW MTNS...TO THE U30S IN THE SOUTHERN VALLEYS. HOWEVER...ARRIVAL OF PRECIP AND LOW LVL COLD ADVECTION WILL DROP READINGS TO THE TEENS AND 20S BY DAWN. A STRONG JET ENTRANCE REGION ALOFT WILL SLIDE BY JUST NORTH OF THE REGION TONIGHT AND THURSDAY...SUPPORTING AN AREA OF POTENT LOW-MID LEVEL FRONTOGENETIC FORCING. MODELS RESPOND BY BRINGING A FAIRLY PROLONGED PERIOD OF PRECIP TO MY FAR SOUTHERN ZONES. 21Z SREF AND 18Z GEFS THREAT PAGES STILL PAINT MY FAR SERN ZONES AS HAVING THE HIGHEST RISK FOR HEAVY SNOW THROUGH MID DAY THURSDAY...WITH A RATHER SHARP CUT OFF ON THE BACK SIDE UP INTO THE CENTRAL MOUNTAINS. HOWEVER...LEANING TOWARD THE MORE RECENT 00Z AND HRRR GUIDANCE...WHICH INDICATES SLIGHTLY LOWER AMTS THAN EARLIER EXPECTED. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... BLEND OF LATEST MDL DATA INDICATE SNOW WILL TAPER OFF BY LATE AM ACROSS THE CENTRAL COUNTIES...AND MAY LAST UNTIL LATE AFTN ACROSS YORK/LANCASTER COUNTIES. ARCTIC HIGH AND ASSOC DRY AIR MASS WILL ARRIVE EARLY OVR THE NW COUNTIES...RESULTING IN DRY/COLD WX THE ENTIRE DAY UP THERE. SOME PARTIAL CLEARING APPEARS LIKELY ACROSS THE NW COUNTIES LATE IN THE DAY. ELSEWHERE...MDL SOUNDINGS INDICATE A MID LVL CLOUD DECK WILL LINGER EVEN AFTER THE SNOW ENDS. OVERCAST SKIES AND COLD ADVECTION WILL LIKELY BLUNT ANY DIURNAL WARMING AND RESULT IN STEADY TEMPS THRU EARLY AFTN...THEN FALLING TEMPS LATE. CONSALL OUTPUT SUPPORTS DAYTIME TEMPS FROM ONLY ARND 10F ACROSS THE NW MTNS...TO THE L20S ACROSS THE SOUTHEAST COUNTIES...ANOTHER EXCEPTIONALLY COLD DAY FOR THE TIME OF YEAR. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE AND BELOW NORMAL LOW-LEVEL TEMPERATURES WILL DOMINATE THE REGION THURSDAY NIGHT INTO LATE FRIDAY. UNSEASONABLY COLD AIR...PERHAPS THE LAST OF THE SIGNIFICANT ARCTIC SURGES OF OUR ENDLESS WINTER. BASED ON THE LOW TEMPERATURES NEAR AND BELOW 0F AND THE WINDS...THE POTENTIAL EXISTS FOR SOME AREAS TO EXPERIENCE WIND CHILLS OVERNIGHT THURSDAY INTO FRIDAY WHICH MIGHT REQUIRE AN ADVISORY ACROSS THE NORTHERN TIER COUNTIES. SATURDAY THE TEMPERATURES AT 850 MB RETURN CLOSER TO NORMAL AND HIGH PRESSURE DRIFTS TO OUR SOUTH. PENNSYLVANIA SHOULD REMAIN NORTH OF THIS WEAK HIGH....CUTTING OFF ANY MOISTURE TO THE SOUTH...KEEPING THE REGION IN WEAK WESTERLY FLOW INTO MONDAY. THE PERIOD SHOULD BE RELATIVELY DRY WITH ANY FRONTAL PRECIPITATION SUPPRESSED TO OUR SOUTH AND ONLY WEAK NORTHERN STREAM WAVES TO OUR NORTH TO GENERATE ANY PRECIPITATION. SO...KEPT THE POPS LOW THROUGH THE PERIOD AND ANY LIGHT PRECIPITATION WOULD LIKELY BE SNOW AS 850 HPA TEMPS STAY BELOW 0C. BEST CHANCE OF ANY PRECIPITATION WOULD BE IN NORTHERN AREAS SHOULD ONE OF THE NORTHERN STREAM WAVES PROVE TO BE STRONGER THAN GUIDANCE IMPLIES. A RIDGE IS FORECAST TO BUILD OVER THE REGION TUESDAY INTO WEDNESDAY AND OUR LOWER TROPOSPHERE TEMPERATURES SHOULD GET AT LEAST SLIGHTLY....ABOVE NORMAL....BOTH TUESDAY INTO WEDNESDAY. THIS SHOULD PROVIDE AT LEAST 2 DAYS OF NEAR SEASONAL TEMPERATURES FOR A CHANGE. RELATIVELY WARM DAYS AND COLD NIGHTS...A GOOD SLOW WAY TO MELT SNOW WITHOUT FLOODING. THE NAEFSBC AND GEFSBC SUGGEST A FRONTAL PASSAGE THURSDAY WITH SLIGHTLY COLDER TEMPERATURES AS ANOTHER HIGH PRESSURE SYSTEM IS FORECAST TO MOVE OVER THE NORTHEASTERN UNITED STATES THURSDAY INTO SATURDAY NEXT WEEK. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... MOISTURE OVERRUNNING A WAVY COLD FRONT TO THE SOUTH OF THE AREA WILL BRING ANOTHER ROUND OF RAIN/SNOW MAINLY TO AREAS SOUTH OF I-80 TONIGHT INTO EARLY THURSDAY. WIDESPREAD MVFR/IFR WILL CONTINUE OVERNIGHT THROUGH AT LEAST MID DAY THURSDAY BEFORE DRIER AIR BEGINS MOVING INTO THE REGION FROM THE WEST AND NORTH BRINGING IMPROVING CONDITIONS. WORST CONDS ATTM OVER LOWER SUSQ VALLEY WHERE DENSE FOG IS CAUSING VLIFR VSBYS AT KLNS. THIS SHOULD PERSIST THROUGH AT LEAST MIDNIGHT UNTIL STRONGER NW WINDS HELP TO MIX UP THE AMS. OUTLOOK... THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 10 AM EST THURSDAY FOR PAZ017>019-049-051-053. WINTER WEATHER ADVISORY UNTIL 1 PM EST THURSDAY FOR PAZ024>028- 034-035-050-052-056>059-063. WINTER STORM WARNING UNTIL 4 PM EST THURSDAY FOR PAZ033-036- 064>066. && $$ SYNOPSIS...GRUMM/LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...GRUMM AVIATION...GARTNER/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
911 PM EST WED MAR 4 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA THIS EVENING AND EARLY THURSDAY. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WATER VAPOR/SATL DERIVED PWAT IMAGERY SHOWING AN ATMOSPHERIC RIVER OF ANOMALOUS PWATS EXTENDING FROM THE S PACIFIC OCEAN NEWRD INTO THE MISS VALLEY AND EVENTUALLY PA. THIS DEEP MOISTURE PLUME IS OVERRUNNING AN EXPANSIVE ARCTIC HIGH PRES TO THE NORTH...CREATING A BAND OF MIXED PRECIP FROM THE PLAINS INTO SOUTHERN PA. AS OF 23Z...PTYPE IS LGT RAIN ACROSS MOST OF SOUTHERN PA. HOWEVER...THE HIGHER TERRAIN FROM KFIG SOUTH THRU KJST IS NOW REPORTING SNOW. AS WEAK WAVE OF LOW PRES PASSES SOUTH OF PA OVERNIGHT...PRECIP WILL EXPAND NORTH ACROSS THE STATE...WHILE COLDER AIR FILTERS IN ON NW FLOW. ALL LATEST MDL DATA POINTING TOWARD A GENERAL 2-4 INCH SNOWFALL ACROSS THE SOUTHERN COUNTIES OVERNIGHT. 18Z MDL SOUNDINGS AND LATEST HRRR OUTPUT BOTH INDICATE THERMAL PROFILES WILL REMAIN TOO WARM FOR SNOW ACROSS THE LOWER SUSQ VALLEY UNTIL ARND 06Z. THUS...HAVE WILL LOWER AMTS THERE. TEMPERATURES AT 23Z RUNNING FROM ARND 30F ACROSS THE NW MTNS...TO AROUND 40F IN THE SOUTHERN VALLEYS. HOWEVER...ARRIVAL OF PRECIP AND LOW LVL COLD ADVECTION WILL DROP READINGS TO THE TEENS AND 20S BY DAWN. A STRONG JET ENTRANCE REGION ALOFT WILL SLIDE BY JUST NORTH OF THE REGION TONIGHT AND THURSDAY...SUPPORTING AN AREA OF POTENT LOW-MID LEVEL FRONTOGENETIC FORCING. MODELS RESPOND BY BRINGING A FAIRLY PROLONGED PERIOD OF PRECIP TO MY FAR SOUTHERN ZONES. 15Z SREF AND 12Z GEFS THREAT PAGES STILL PAINT MY FAR SERN ZONES AS HAVING THE HIGHEST RISK FOR HEAVY SNOW THROUGH MID DAY THURSDAY...WITH A RATHER SHARP CUT OFF ON THE BACK SIDE UP INTO THE CENTRAL MOUNTAINS. HOWEVER...LEANING TOWARD THE MORE RECENT 18Z AND HRRR GUIDANCE...WHICH INDICATES LOWER AMTS THAN EARLIER EXPECTED. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... LATEST GEFS/SREF SHOW PRECIP ENDING FROM NW TO SE AS THE DAY WEARS ON WITH MUCH OF THE DAY ENDING UP DRY OVER MY NORTHERN TIER...AND MAINLY DRY AFTER 18Z NORTH OF I-80. STILL YET ANOTHER VERY COLD DAY IS IN STORE WITH MAX TEMPS SOME 20-30 DEG BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE AND BELOW NORMAL LOW-LEVEL TEMPERATURES WILL DOMINATE THE REGION THURSDAY NIGHT INTO LATE FRIDAY. UNSEASONABLY COLD AIR...PERHAPS THE LAST OF THE SIGNIFICANT ARCTIC SURGES OF OUR ENDLESS WINTER. BASED ON THE LOW TEMPERATURES NEAR AND BELOW 0F AND THE WINDS...THE POTENTIAL EXISTS FOR SOME AREAS TO EXPERIENCE WIND CHILLS OVERNIGHT THURSDAY INTO FRIDAY WHICH MIGHT REQUIRE AN ADVISORY ACROSS THE NORTHERN TIER COUNTIES. SATURDAY THE TEMPERATURES AT 850 MB RETURN CLOSER TO NORMAL AND HIGH PRESSURE DRIFTS TO OUR SOUTH. PENNSYLVANIA SHOULD REMAIN NORTH OF THIS WEAK HIGH....CUTTING OFF ANY MOISTURE TO THE SOUTH...KEEPING THE REGION IN WEAK WESTERLY FLOW INTO MONDAY. THE PERIOD SHOULD BE RELATIVELY DRY WITH ANY FRONTAL PRECIPITATION SUPPRESSED TO OUR SOUTH AND ONLY WEAK NORTHERN STREAM WAVES TO OUR NORTH TO GENERATE ANY PRECIPITATION. SO...KEPT THE POPS LOW THROUGH THE PERIOD AND ANY LIGHT PRECIPITATION WOULD LIKELY BE SNOW AS 850 HPA TEMPS STAY BELOW 0C. BEST CHANCE OF ANY PRECIPITATION WOULD BE IN NORTHERN AREAS SHOULD ONE OF THE NORTHERN STREAM WAVES PROVE TO BE STRONGER THAN GUIDANCE IMPLIES. A RIDGE IS FORECAST TO BUILD OVER THE REGION TUESDAY INTO WEDNESDAY AND OUR LOWER TROPOSPHERE TEMPERATURES SHOULD GET AT LEAST SLIGHTLY....ABOVE NORMAL....BOTH TUESDAY INTO WEDNESDAY. THIS SHOULD PROVIDE AT LEAST 2 DAYS OF NEAR SEASONAL TEMPERATURES FOR A CHANGE. RELATIVELY WARM DAYS AND COLD NIGHTS...A GOOD SLOW WAY TO MELT SNOW WITHOUT FLOODING. THE NAEFSBC AND GEFSBC SUGGEST A FRONTAL PASSAGE THURSDAY WITH SLIGHTLY COLDER TEMPERATURES AS ANOTHER HIGH PRESSURE SYSTEM IS FORECAST TO MOVE OVER THE NORTHEASTERN UNITED STATES THURSDAY INTO SATURDAY NEXT WEEK. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... MOISTURE OVERRUNNING A WAVY COLD FRONT TO THE SOUTH OF THE AREA WILL BRING ANOTHER ROUND OF RAIN/SNOW MAINLY TO AREAS SOUTH OF I-80 TONIGHT INTO EARLY THURSDAY. WIDESPREAD MVFR/IFR WILL CONTINUE OVERNIGHT THROUGH AT LEAST MID DAY THURSDAY BEFORE DRIER AIR BEGINS MOVING INTO THE REGION FROM THE WEST AND NORTH BRINGING IMPROVING CONDITIONS. WORST CONDS ATTM OVER LOWER SUSQ VALLEY WHERE DENSE FOG IS CAUSING VLIFR VSBYS AT KLNS. THIS SHOULD PERSIST THROUGH AT LEAST MIDNIGHT UNTIL STRONGER NW WINDS HELP TO MIX UP THE AMS. OUTLOOK... THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 10 AM EST THURSDAY FOR PAZ017>019-049-051-053. WINTER WEATHER ADVISORY UNTIL 1 PM EST THURSDAY FOR PAZ024>028- 034>036-050-052-056>059-063. WINTER STORM WARNING UNTIL 4 PM EST THURSDAY FOR PAZ033- 064>066. && $$ SYNOPSIS...GRUMM/LA CORTE NEAR TERM...FITZGERALD/LA CORTE SHORT TERM...LA CORTE LONG TERM...GRUMM AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
633 PM EST WED MAR 4 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA THIS EVENING AND EARLY THURSDAY. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WATER VAPOR/SATL DERIVED PWAT IMAGERY SHOWING AN ATMOSPHERIC RIVER OF ANOMALOUS PWATS EXTENDING FROM THE S PACIFIC OCEAN NEWRD INTO THE MISS VALLEY AND EVENTUALLY PA. THIS DEEP MOISTURE PLUME IS OVERRUNNING AN EXPANSIVE ARCTIC HIGH PRES TO THE NORTH...CREATING A BAND OF MIXED PRECIP FROM THE PLAINS INTO SOUTHERN PA. AS OF 23Z...PTYPE IS LGT RAIN ACROSS MOST OF SOUTHERN PA. HOWEVER...THE HIGHER TERRAIN FROM KFIG SOUTH THRU KJST IS NOW REPORTING SNOW. AS WEAK WAVE OF LOW PRES PASSES SOUTH OF PA OVERNIGHT...PRECIP WILL EXPAND NORTH ACROSS THE STATE...WHILE COLDER AIR FILTERS IN ON NW FLOW. ALL LATEST MDL DATA POINTING TOWARD A GENERAL 2-4 INCH SNOWFALL ACROSS THE SOUTHERN COUNTIES OVERNIGHT. 18Z MDL SOUNDINGS AND LATEST HRRR OUTPUT BOTH INDICATE THERMAL PROFILES WILL REMAIN TOO WARM FOR SNOW ACROSS THE LOWER SUSQ VALLEY UNTIL ARND 06Z. THUS...HAVE WILL LOWER AMTS THERE. TEMPERATURES AT 23Z RUNNING FROM ARND 30F ACROSS THE NW MTNS...TO AROUND 40F IN THE SOUTHERN VALLEYS. HOWEVER...ARRIVAL OF PRECIP AND LOW LVL COLD ADVECTION WILL DROP READINGS TO THE TEENS AND 20S BY DAWN. A STRONG JET ENTRANCE REGION ALOFT WILL SLIDE BY JUST NORTH OF THE REGION TONIGHT AND THURSDAY...SUPPORTING AN AREA OF POTENT LOW-MID LEVEL FRONTOGENETIC FORCING. MODELS RESPOND BY BRINGING A FAIRLY PROLONGED PERIOD OF PRECIP TO MY FAR SOUTHERN ZONES. 15Z SREF AND 12Z GEFS THREAT PAGES STILL PAINT MY FAR SERN ZONES AS HAVING THE HIGHEST RISK FOR HEAVY SNOW THROUGH MID DAY THURSDAY...WITH A RATHER SHARP CUT OFF ON THE BACK SIDE UP INTO THE CENTRAL MOUNTAINS. HOWEVER...LEANING TOWARD THE MORE RECENT 18Z AND HRRR GUIDANCE...WHICH INDICATES LOWER AMTS THAN EARLIER EXPECTED. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... LATEST GEFS/SREF SHOW PRECIP ENDING FROM NW TO SE AS THE DAY WEARS ON WITH MUCH OF THE DAY ENDING UP DRY OVER MY NORTHERN TIER...AND MAINLY DRY AFTER 18Z NORTH OF I-80. STILL YET ANOTHER VERY COLD DAY IS IN STORE WITH MAX TEMPS SOME 20-30 DEG BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE AND BELOW NORMAL LOW-LEVEL TEMPERATURES WILL DOMINATE THE REGION THURSDAY NIGHT INTO LATE FRIDAY. UNSEASONABLY COLD AIR...PERHAPS THE LAST OF THE SIGNIFICANT ARCTIC SURGES OF OUR ENDLESS WINTER. BASED ON THE LOW TEMPERATURES NEAR AND BELOW 0F AND THE WINDS...THE POTENTIAL EXISTS FOR SOME AREAS TO EXPERIENCE WIND CHILLS OVERNIGHT THURSDAY INTO FRIDAY WHICH MIGHT REQUIRE AN ADVISORY ACROSS THE NORTHERN TIER COUNTIES. SATURDAY THE TEMPERATURES AT 850 MB RETURN CLOSER TO NORMAL AND HIGH PRESSURE DRIFTS TO OUR SOUTH. PENNSYLVANIA SHOULD REMAIN NORTH OF THIS WEAK HIGH....CUTTING OFF ANY MOISTURE TO THE SOUTH...KEEPING THE REGION IN WEAK WESTERLY FLOW INTO MONDAY. THE PERIOD SHOULD BE RELATIVELY DRY WITH ANY FRONTAL PRECIPITATION SUPPRESSED TO OUR SOUTH AND ONLY WEAK NORTHERN STREAM WAVES TO OUR NORTH TO GENERATE ANY PRECIPITATION. SO...KEPT THE POPS LOW THROUGH THE PERIOD AND ANY LIGHT PRECIPITATION WOULD LIKELY BE SNOW AS 850 HPA TEMPS STAY BELOW 0C. BEST CHANCE OF ANY PRECIPITATION WOULD BE IN NORTHERN AREAS SHOULD ONE OF THE NORTHERN STREAM WAVES PROVE TO BE STRONGER THAN GUIDANCE IMPLIES. A RIDGE IS FORECAST TO BUILD OVER THE REGION TUESDAY INTO WEDNESDAY AND OUR LOWER TROPOSPHERE TEMPERATURES SHOULD GET AT LEAST SLIGHTLY....ABOVE NORMAL....BOTH TUESDAY INTO WEDNESDAY. THIS SHOULD PROVIDE AT LEAST 2 DAYS OF NEAR SEASONAL TEMPERATURES FOR A CHANGE. RELATIVELY WARM DAYS AND COLD NIGHTS...A GOOD SLOW WAY TO MELT SNOW WITHOUT FLOODING. THE NAEFSBC AND GEFSBC SUGGEST A FRONTAL PASSAGE THURSDAY WITH SLIGHTLY COLDER TEMPERATURES AS ANOTHER HIGH PRESSURE SYSTEM IS FORECAST TO MOVE OVER THE NORTHEASTERN UNITED STATES THURSDAY INTO SATURDAY NEXT WEEK. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... A WAVY COLD FRONT TO THE SOUTH OF THE AREA WILL BRING ANOTHER ROUND OF RAIN/SNOW MAINLY TO AREAS SOUTH OF I-80 TONIGHT INTO EARLY THURSDAY. WIDESPREAD MVFR/IFR WILL CONTINUE OVERNIGHT THROUGH AT LEAST MID DAY THURSDAY BEFORE DRYER AIR BEGINS MOVING INTO THE REGION FROM THE WEST AND NORTH BRINGING IMPROVING CONDITIONS. OUTLOOK... THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR PAZ017-024-025-033- 034. WINTER WEATHER ADVISORY UNTIL 7 PM EST THURSDAY FOR PAZ017>019- 024>028-049>053-058. WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR PAZ033>036- 056-057-059-063>066. && $$ SYNOPSIS...GRUMM/LA CORTE NEAR TERM...FITZGERALD/LA CORTE SHORT TERM...LA CORTE LONG TERM...GRUMM AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
444 PM EST TUE MAR 3 2015 .SYNOPSIS... MIXED PRECIPITATION WILL CHANGE TO AN EXTENDED PERIOD OF FREEZING RAIN THIS EVENING THROUGH LATE TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS SOUTHERN AND FAR WESTERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART OF THE WEEKEND. && .NEAR TERM /UNTIL 10 PM THIS EVENING/... AT MID AFTERNOON...PRECIPITATION TRANSITION IS WELL UNDERWAY WITH INITIAL BURST OF SNOW HAVING PUSHED INTO THE MIDDLE TO LOWER SUSQ RIVER VALLEY. SNOW AND SLEET WILL HAVE CHANGED OVER TO PRIMARILY FREEZING RAIN BY EARLY EVENING. HRRR HAS VACILLATED CONSIDERABLY FROM HOUR TO HOUR...BOTH WITH QPF AND OVERNIGHT TEMPERATURES...AND THUS AM BASING THE ICE FORECAST AND ITS ASSOCIATED NEAR- TO SHORT- TERM CHANGES ON SHORT RANGE ENSEMBLES AND IN PARTICULAR SREF THREATS WHICH CONSECUTIVELY HAVE INDICATED 80% OR GREATER CONFIDENCE IN .25"+ OF ICE ACCRETION FROM LATE THIS AFTERNOON THROUGH THE EARLY MORNING HOURS (PAST MIDNIGHT) OF WEDNESDAY. WILL UPGRADE TO WINTER STORM WARNINGS (THERE IS STILL SOME SNOW/SLEET BEFORE THE COMPLETE CHANGEOVER) FOR ICE ACROSS THE NORTH CENTRAL MOUNTAINS...WHERE GREATER THAN 0.25" OF ICE IS EXPECTED. FARTHER WEST...A CHANGEOVER TO RAIN IS EXPECTED OVER WARREN AND ELK COUNTIES...HOLDING DOWN AMOUNTS ALONG THE WESTERN BORDERS OF THOSE COUNTIES. THE WARNING AREA MAY NEED TO BE EXPANDED FARTHER SOUTH INTO THE CENTRAL MOUNTAINS IN TIME...BUT CONFIDENCE IN DOING SO SOUTH OF INTERSTATE 80 WAS LOW GIVEN CONFLICTING HRRR LLVL TEMPERATURE READINGS AND QPF DISTRIBUTION THROUGH LATE TONIGHT. THE REST OF THE SOUTHERN THIRD OF CENTRAL PA IS SEEING A SEVERAL HOUR LULL IN PRECIP AT MID AFTERNOON AS A RESULT OF A DRY SLOT WHICH FOLLOWED THE INITIAL WAA BURST. PRECIP FILLING IN BEHIND IS FZRA OVER THE LAURELS AND HEADING INTO THE CENTRAL MOUNTAINS WITH A FEW REPORTS STILL OF SOME SLEET PELLETS MIXED IN. NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE. EVE SHIFT WILL CONT TO MONITOR EVOLUTION OF QPF AND ADJUST ICE AMOUNTS AS NECESSARY. && .SHORT TERM /10 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PROLONGED ICE ACCRETION IS THE MAIN THREAT LATE TONIGHT INTO WEDNESDAY MORNING THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE. BY LATE TONIGHT...WARM AIR WILL BE FLOODING THE SOUTH AND CHANGING FZRA OVER TO PLAIN RAIN. THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY QUITE COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.20-0.30 OF AN INCH ACROSS THE NCENT MTNS OF PA WHERE ADVISORIES ARE BEING UPGRADED TO WARNINGS...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE 80. && .LONG TERM /WEDNESDAY THROUGH TUESDAY/... AN ACTIVE LATE-WINTER PRECIPITATION PATTERN WILL IMPACT CENTRAL PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL AND ENSEMBLE CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST THROUGH THE WEEKEND WITH SOME SIGNS OF A PATTERN SHIFT BY THE MIDDLE OF NEXT WEEK WITH TROUGHING FCST TO DEVELOP ALONG THE WEST COAST. BELOW NORMAL TEMPS SHOULD MODERATE CLOSER TO NORMAL EARLY NEXT WEEK WITH SOME HINTS AT EVEN WARMER TEMPS LATER NEXT WEEK. MODELS CONTINUE TO SHOW AN AMPLIFIED AND MOIST SW FLOW ALOFT AND JET ENTRANCE REGION DYNAMICS SUPPORTING A BROAD STRIPE OF PCPN ALONG A WELL DEFINED BAROCLINIC ZONE AHEAD OF PHASING UPPER LEVEL ENERGY OVER THE DSW/ROCKIES ON WED AND MOVING EWD THROUGH THE OH VLY AND MID ATLC ON THURSDAY. SEVERAL WAVES OF LOW PRESSURE ARE FCST TO DEVELOP AND MOVE ENEWD ALONG A SW-NE ORIENTED COLD FRONT WHICH SHOULD PROGRESS AND SETTLE SEWD THROUGH THE MID ATLC REGION BY EARLY THURS...AS ARCTIC HIGH PRESSURE BUILDS INTO THE UPPER PLAINS. AMPLE MOISTURE IS FCST BY THE MODELS TO MOVE INTO A DEEPENING COLD SECTOR ALONG/NORTH OF THE SEWD-ADVANCING COLD FRONTAL BOUNDARY WHICH COULD RESULT IN A LATE SEASON HEAVY SNOW EVENT FOR SOUTH CENTRAL PA WED NGT INTO THURS. THERE ARE MODEL DIFFERENCES WITH THE TIMING OF THE FRONT WHICH IS LKLY TIED TO THE CONSOLIDATION OF SHORTWAVE ENERGY UPSTREAM. THAT SAID...THE CONSENSUS FCST AXIS OF MAX QPF /0.50 INCH OR GREATER/ HAS BEEN FAIRLY CONSISTENT PAINTED OVER THE SRN 1/3 OF THE CWA. SIMILAR TO YESTERDAY...USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF AMTS WHICH GENERALLY RANGE FROM 0.25 TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF TRANSITION AND COOLING DOWN FROM NW TO SE WED-WED NGT AS THE COLD FRONT PUSHES SOUTHEAST ACROSS THE AREA. THIS SHOULD SUPPORT A TRANSITION FROM RAIN TO SNOW. A PERIOD OF SLEET MAY IMPACT FCST SNOW ACCUMULATIONS WITH THE DURATION A KEY FACTOR IN THIS FCST. WITH INCREASING CONFIDENCE AND GREATEST RISK IN THE POTENTIAL FOR HEAVY SNOW/6+ INCHES...WHICH IS SUPPORTED BY ROBUST WPC ENSEMBLE AS WELL AS THE GEFS MEAN...HAVE ISSUED A WINTER STORM WATCH FOR THE SOUTH-CENTRAL COUNTIES FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING. WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR THIS SEASON SHOULD ARRIVE BEHIND THE COLD FRONT. FRIDAY MORNING LOWS ARE LKLY TO BE 20-30F BELOW NORMAL WITH SINGLE DIGIT LOWS +/- ZERO DEGREES. SUCH READINGS MAY BREAK DAILY RECORDS. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... A LARGE AREA OF SLEET AND FREEZING RAIN OVER THE AREA AS OF LATE AFT. MINOR ADJUSTMENTS MADE TO 21Z TAFS. EARLIER DISCUSSION BELOW. WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A PROLONGED WINTRY MIX/FREEZING RAIN EVENT THIS AFTERNOON THROUGH EARLY WEDNESDAY MORNING ACROSS MUCH OF CENTRAL PA. SNOW/SLEET WILL CHANGE TO FREEZING RAIN SOUTH THIS AFTERNOON...AND EVEN PLAIN RAIN ACROSS THE LAUREL HIGHLANDS AND SOUTH CENTRAL MOUNTAINS AND LOWER SUSQUEHANNA RIVER VALLEY BY THIS EVENING. FARTHER NORTH...COLD AIR WILL REMAIN LOCKED OVER THE NORTH CENTRAL MOUNTAINS MAINTAINING FREEZING RAIN THROUGH EARLY WEDNESDAY MORNING. AS A RESULT...WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD FROM THIS AFTERNOON THROUGH LATE TONIGHT. LLWS WILL ALSO BE PREVALENT AS 850MB WINDS INCREASE TO AROUND 50 KTS. LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW AND SIGNIFICANT FREEZING RAIN AS WELL. OUTLOOK... WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN THE DAY. WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE SOUTH. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN...MVFR WITH CHC -SHSN MAINLY NORTH. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ004- 010-017-019-024>028-033>036-042-045-046-049>053-056>059- 063>066. WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR PAZ024>028-033>036-056>059-063>066. WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR PAZ005-006- 011-012-018-037-041. && $$ SYNOPSIS...DEVOIR NEAR TERM...DEVOIR SHORT TERM...DEVOIR LONG TERM...STEINBUGL AVIATION...DEVOIR/MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
407 PM EST TUE MAR 3 2015 .SYNOPSIS... MIXED PRECIPITATION WILL CHANGE TO AN EXTENDED PERIOD OF FREEZING RAIN THIS EVENING THROUGH LATE TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS SOUTHERN AND FAR WESTERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART OF THE WEEKEND. && .NEAR TERM /UNTIL 10 PM THIS EVENING/... AT MID AFTERNOON...PRECIPITATION TRANSITION IS WELL UNDERWAY WITH INITIAL BURST OF SNOW HAVING PUSHED INTO THE MIDDLE TO LOWER SUSQ RIVER VALLEY. SNOW AND SLEET WILL HAVE CHANGED OVER TO PRIMARILY FREEZING RAIN BY EARLY EVENING. HRRR HAS VACILLATED CONSIDERABLY FROM HOUR TO HOUR...BOTH WITH QPF AND OVERNIGHT TEMPERATURES...AND THUS AM BASING THE ICE FORECAST AND ITS ASSOCIATED NEAR- TO SHORT- TERM CHANGES ON SHORT RANGE ENSEMBLES AND IN PARTICULAR SREF THREATS WHICH CONSECUTIVELY HAVE INDICATED 80% OR GREATER CONFIDENCE IN .25"+ OF ICE ACCRETION FROM LATE THIS AFTERNOON THROUGH THE EARLY MORNING HOURS (PAST MIDNIGHT) OF WEDNESDAY. WILL UPGRADE TO WINTER STORM WARNINGS (THERE IS STILL SOME SNOW/SLEET BEFORE THE COMPLETE CHANGEOVER) FOR ICE ACROSS THE NORTH CENTRAL MOUNTAINS...WHERE GREATER THAN 0.25" OF ICE IS EXPECTED. FARTHER WEST...A CHANGEOVER TO RAIN IS EXPECTED OVER WARREN AND ELK COUNTIES...HOLDING DOWN AMOUNTS ALONG THE WESTERN BORDERS OF THOSE COUNTIES. THE WARNING AREA MAY NEED TO BE EXPANDED FARTHER SOUTH INTO THE CENTRAL MOUNTAINS IN TIME...BUT CONFIDENCE IN DOING SO SOUTH OF INTERSTATE 80 WAS LOW GIVEN CONFLICTING HRRR LLVL TEMPERATURE READINGS AND QPF DISTRIBUTION THROUGH LATE TONIGHT. THE REST OF THE SOUTHERN THIRD OF CENTRAL PA IS SEEING A SEVERAL HOUR LULL IN PRECIP AT MID AFTERNOON AS A RESULT OF A DRY SLOT WHICH FOLLOWED THE INITIAL WAA BURST. PRECIP FILLING IN BEHIND IS FZRA OVER THE LAURELS AND HEADING INTO THE CENTRAL MOUNTAINS WITH A FEW REPORTS STILL OF SOME SLEET PELLETS MIXED IN. NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE. EVE SHIFT WILL CONT TO MONITOR EVOLUTION OF QPF AND ADJUST ICE AMOUNTS AS NECESSARY. && .SHORT TERM /10 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PROLONGED ICE ACCRETION IS THE MAIN THREAT LATE TONIGHT INTO WEDNESDAY MORNING THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE. BY LATE TONIGHT...WARM AIR WILL BE FLOODING THE SOUTH AND CHANGING FZRA OVER TO PLAIN RAIN. THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY QUITE COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.20-0.30 OF AN INCH ACROSS THE NCENT MTNS OF PA WHERE ADVISORIES ARE BEING UPGRADED TO WARNINGS...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE 80. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AN ACTIVE LATE-WINTER PRECIPITATION PATTERN WILL IMPACT CENTRAL PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL AND ENSEMBLE CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST THROUGH THE WEEKEND WITH SOME SIGNS OF A PATTERN SHIFT BY THE MIDDLE OF NEXT WEEK WITH TROUGHING FCST TO DEVELOP ALONG THE WEST COAST. BELOW NORMAL TEMPS SHOULD MODERATE CLOSER TO NORMAL EARLY NEXT WEEK WITH SOME HINTS AT EVEN WARMER TEMPS LATER NEXT WEEK. MODELS CONTINUE TO SHOW AN AMPLIFIED AND MOIST SW FLOW ALOFT AND JET ENTRANCE REGION DYNAMICS SUPPORTING A BROAD STRIPE OF PCPN ALONG A WELL DEFINED BAROCLINIC ZONE AHEAD OF PHASING UPPER LEVEL ENERGY OVER THE DSW/ROCKIES ON WED AND MOVING EWD THROUGH THE OH VLY AND MID ATLC ON THURSDAY. SEVERAL WAVES OF LOW PRESSURE ARE FCST TO DEVELOP AND MOVE ENEWD ALONG A SW-NE ORIENTED COLD FRONT WHICH SHOULD PROGRESS AND SETTLE SEWD THROUGH THE MID ATLC REGION BY EARLY THURS...AS ARCTIC HIGH PRESSURE BUILDS INTO THE UPPER PLAINS. AMPLE MOISTURE IS FCST BY THE MODELS TO MOVE INTO A DEEPENING COLD SECTOR ALONG/NORTH OF THE SEWD-ADVANCING COLD FRONTAL BOUNDARY WHICH COULD RESULT IN A LATE SEASON HEAVY SNOW EVENT FOR SOUTH CENTRAL PA WED NGT INTO THURS. THERE ARE MODEL DIFFERENCES WITH THE TIMING OF THE FRONT WHICH IS LKLY TIED TO THE CONSOLIDATION OF SHORTWAVE ENERGY UPSTREAM. THAT SAID...THE CONSENSUS FCST AXIS OF MAX QPF /0.50 INCH OR GREATER/ HAS BEEN FAIRLY CONSISTENT PAINTED OVER THE SRN 1/3 OF THE CWA. SIMILAR TO YESTERDAY...USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF AMTS WHICH GENERALLY RANGE FROM 0.25 TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF TRANSITION AND COOLING DOWN FROM NW TO SE WED-WED NGT AS THE COLD FRONT PUSHES SOUTHEAST ACROSS THE AREA. THIS SHOULD SUPPORT A TRANSITION FROM RAIN TO SNOW. A PERIOD OF SLEET MAY IMPACT FCST SNOW ACCUMULATIONS WITH THE DURATION A KEY FACTOR IN THIS FCST. WITH INCREASING CONFIDENCE AND GREATEST RISK IN THE POTENTIAL FOR HEAVY SNOW/6+ INCHES...WHICH IS SUPPORTED BY ROBUST WPC ENSEMBLE AS WELL AS THE GEFS MEAN...HAVE ISSUED A WINTER STORM WATCH FOR THE SOUTH-CENTRAL COUNTIES FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING. WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR THIS SEASON SHOULD ARRIVE BEHIND THE COLD FRONT. FRIDAY MORNING LOWS ARE LKLY TO BE 20-30F BELOW NORMAL WITH SINGLE DIGIT LOWS +/- ZERO DEGREES. SUCH READINGS MAY BREAK DAILY RECORDS. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A PROLONGED WINTRY MIX/FREEZING RAIN EVENT THIS AFTERNOON THROUGH EARLY WEDNESDAY MORNING ACROSS MUCH OF CENTRAL PA. SNOW/SLEET WILL CHANGE TO FREEZING RAIN SOUTH THIS AFTERNOON...AND EVEN PLAIN RAIN ACROSS THE LAUREL HIGHLANDS AND SOUTH CENTRAL MOUNTAINS AND LOWER SUSQUEHANNA RIVER VALLEY BY THIS EVENING. FARTHER NORTH...COLD AIR WILL REMAIN LOCKED OVER THE NORTH CENTRAL MOUNTAINS MAINTAINING FREEZING RAIN THROUGH EARLY WEDNESDAY MORNING. AS A RESULT...WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD FROM THIS AFTERNOON THROUGH LATE TONIGHT. LLWS WILL ALSO BE PREVALENT AS 850MB WINDS INCREASE TO AROUND 50 KTS. LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW AND SIGNIFICANT FREEZING RAIN AS WELL. OUTLOOK... WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN THE DAY. WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE SOUTH. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN...MVFR WITH CHC -SHSN MAINLY NORTH. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ004- 010-017-019-024>028-033>036-042-045-046-049>053-056>059- 063>066. WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR PAZ024>028-033>036-056>059-063>066. WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR PAZ005-006- 011-012-018-037-041. && $$ SYNOPSIS...DEVOIR NEAR TERM...DEVOIR SHORT TERM...DEVOIR LONG TERM...STEINBUGL AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
225 PM EST TUE MAR 3 2015 .SYNOPSIS... MIXED PRECIPITATION WILL CHANGE TO AN EXTENDED PERIOD OF FREEZING RAIN THIS EVENING THROUGH LATE TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS SOUTHERN AND FAR WESTERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART OF THE WEEKEND. && .NEAR TERM /UNTIL 10 PM THIS EVENING/... AT MID AFTERNOON...PRECIPITATION TRANSITION IS WELL UNDERWAY WITH INITIAL BURST OF SNOW HAVING PUSHED INTO THE MIDDLE TO LOWER SUSQ RIVER VALLEY. SNOW AND SLEET WILL HAVE CHANGED OVER TO PRIMARILY FREEZING RAIN BY EARLY EVENING. HRRR HAS VASCILLATED CONSIDERABLY FROM HOUR TO HOUR...BOTH WITH QPF AND OVERNIGHT TEMPERATURES...AND THUS AM BASING THE ICE FORECAST AND ITS ASSOCIATED NEAR- TO SHORT- TERM CHANGES ON SHORT RANGE ENSEMBES AND IN PARTICULAR SREF THREATS WHICH CONSECUTIVELY HAVE INDICATED 80% OR GREATER CONFIDENCE IN .25"+ OF ICE ACCRETION FROM LATE THIS AFTERNOON THROUGH THE EARLY MORNING HOURS (PAST MIDNIGHT) OF WEDNESDAY. WILL UPGRADE TO WINTER STORM WARNINGS (THERE IS STILL SOME SNOW/SLEET BEFORE THE COMPLETE CHANGEOVER) FOR ICE ACROSS THE NORTH CENTRAL MOUNTAINS...WHERE GREATER THAN 0.25" OF ICE IS EXPECTED. FARTHER WEST...A CHANGEOVER TO RAIN IS EXPECTED OVER WARREN AND ELK COUNTIES...HOLDING DOWN AMOUNTS ALONG THE WESTERN BORDERS OF THOSE COUNTIES. THE WARNING AREA MAY NEED TO BE EXPANDED FARTHER SOUTH INTO THE CENTRAL MOUNTAINS IN TIME...BUT CONFIDENCE IN DOING SO SOUTH OF INTERSTATE 80 WAS LOW GIVEN CONFLICTING HRRR LLVL TEMPERATURE READINGS AND QPF DISTRIBUTION THROUGH LATE TONIGHT. THE REST OF THE SOUTHERN THIRD OF CENTRAL PA IS SEEING A SEVERAL HOUR LULL IN PRECIP AT MID AFTERNOON AS A RESULT OF A DRY SLOT WHICH FOLLOWED THE INITIAL WAA BURST. PRECIP FILLING IN BEHIND IS FZRA OVER THE LAURELS AND HEADING INTO THE CENTRAL MOUNTAINS WITH A FEW REPORTS STILL OF SOME SLEET PELLETS MIXED IN. NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE. EVE SHIFT WILL CONT TO MONITOR EVOLUTION OF QPF AND ADJUST ICE AMOUNTS AS NECESSARY. && .SHORT TERM /10 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... PROLONGED ICE ACCRETION IS THE MAIN THREAT LATE TONIGHT INTO WEDNESDAY MORNING THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE. BY LATE TONIGHT...WARM AIR WILL BE FLOODING THE SOUTH AND CHANGING FZRA OVER TO PLAIN RAIN. THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY QUITE COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.20-0.30 OF AN INCH ACROSS THE NCENT MTNS OF PA WHERE ADVISORIES ARE BEING UPGRADED TO WARNINGS...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE 80. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS. MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN. SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA. HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY 3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN PORTIONS OF THE CWA. WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A PROLONGED WINTRY MIX/FREEZING RAIN EVENT THIS AFTERNOON THROUGH EARLY WEDNESADY MORNING ACROSS MUCH OF CENTRAL PA. SNOW/SLEET WILL CHANGE TO FREEZING RAIN SOUTH THIS AFTERNOON...AND EVEN PLAIN RAIN ACROSS THE LAUREL HIGHLANDS AND SOUTH CENTRAL MOUNTAINS AND LOWER SUSQUEHANNA RIVER VALLEY BY THIS EVENING. FARTHER NORTH...COLD AIR WILL REMAIN LOCKED OVER THE NORTH CENTRAL MOUNTAINS MAINTAINING FREEZING RAIN THROUGH EARLY WEDNESDAY MORNING. AS A RESULT...WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD FROM THIS AFTERNOON THROUGH LATE TONIGHT. LLWS WILL ALSO BE PREVALENT AS 850MB WINDS INCREASE TO AROUND 50 KTS. LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW AND SIGNIFICANT FREEZING RAIN AS WELL. OUTLOOK... WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN THE DAY. WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE SOUTH. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN...MVFR WITH CHC -SHSN MAINLY NORTH. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ004- 010-017-019-024>028-033>036-042-045-046-049>053-056>059- 063>066. WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR PAZ005-006- 011-012-018-037-041. && $$ SYNOPSIS...DEVOIR NEAR TERM...DEVOIR SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1148 AM EST TUE MAR 3 2015 .SYNOPSIS... AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES WILL MOVE QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A SURGE OF DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE COLD AIR IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART OF THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AT MIDDAY...PRIMARY BURST OF WARM ADVECTION IS MAINTAINING/PROPOGATING A MODERATE BAND OF SNOW EXTENDING FROM THE NORTHWEST MOUNTAINS TO THE LOWER SUSQ RIVER VALLEY...WITH A LARGE DRY SLOT OVER SOUTHEAST OHIO AND SOUTHWEST PA FILLING IN WITH MORE SHOWERY ELEMENTS. TEMPERATURES OVER SOMERSET COUNTY RANG FROM THE LOWER 20S NORTH TO THE UPPER 20S SOUTH WITHIN THIS DRY SLOT. SUBSEQUENT PRECIP SHOULD BE MIX TO FZRA THIS AFTERNOON. THE REST OF THE SOUTHERN THIRD OF CENTRAL PA WILL SEE A SEVERAL HOUR LULL IN PRECIP EARLY TO MID AFTERNOON AS A RESULT OF THIS DRY SLOT...AFTER THE INITIAL WAA BAND CROSSES. ACROSS THE NORTHERN HALF OF CENTRAL PA...TRANSITIONS TO SLEET AND THEN FREEZING RAIN WILL TAKE PLACE MID TO LATE AFTERNOON. NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE...BUT STILL CONCERNED THAT WE`LL EXCEED ADVISORY CRITERIA FOR ICE LATER TONIGHT NORTH OF INTERSATE 80. ADJUSTED ICE AMOUNTS UPWARD BY SEVERAL HUNDRETHS ALONG AND NORTH OF I80 WHICH KEEPS AMOUNTS WITHIN ADVISORY CRITERIA. 06Z SREF THREATS BACKED OFF ON EARLIER ROBUST AMOUNTS AND PERCENTAGES...BUT PREVIOUS THREATS HAD INDICATED 70-80% CONFIDENCE IN .20-.30" OR MORE OF ICE. SUCCESSIVE HRRR RUNS CONTINUE TO DELAY WARMING AT THE END OF ITS 15-HOUR WINDOW...MEANING THAT MUCH OF NORTH CENTRAL PA WILL LIKELY NEVER RISE ABOVE FREEZING. CRITICAL TIMEFRAME WILL BE BETWEEN 21Z AND 04Z...AND THINK IT WILL BE A WHITES OF THEIR EYES DECISION FOR THE EVENING SHFIT BASED ON RADAR EVOLUTION AND ADJUSTMENTS OF HRW-ARW AND HRRR CONSENSUS LATE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... PROLONGED ICE ACCRETION IS THE MAIN THREAT TONIGHT THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE /AND TO A LESSER DEGREE ACROSS THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY THE COATING TO 1 INCH OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW IN MOST AREAS (WITH UP TO 3 INCHES NORTH). THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE 80. WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET ACCUM...FOLLOWED BY FREEZING RAIN...THIS AFTERNOON THROUGH THE EARLY MORNING HOURS ON WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS. MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN. SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA. HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY 3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN PORTIONS OF THE CWA. WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... CONDITIONS WILL QUICKLY DETERIORATE FROM WEST TO EAST AS MODERATE SNOW BANDS CROSS THROUGH THE CENTRAL AND NORTH CENTRAL MOUNTAINS THROUGH MIDDAY AND EARLY AFTERNOON HOURS. WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A TRANSITION TO A WINTRY MIX/FREEZING RAIN EVENT BY MID TO LATE AFTERNOON INTO THE EARLY EVENING...BEFORE CHANGING TO RAIN /FZRA NORTH/ LATE TONIGHT INTO EARLY WED AS HEAVIER PRECIP GRADUALLY TAPERS OFF. WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB WINDS INCREASE TO AROUND 50 KTS. LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW AND SIGNIFICANT FREEZING RAIN AS WELL. OUTLOOK... WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN THE DAY. WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE SOUTH. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST WEDNESDAY FOR PAZ006-011-012-018-037-041-042. WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR PAZ004- 005-010-017-024>026-033>035. WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059- 063>066. && $$ SYNOPSIS...DEVOIR/LAMBERT NEAR TERM...DEVOIR/LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1057 AM EST TUE MAR 3 2015 .SYNOPSIS... AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES WILL MOVE QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A SURGE OF DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE COLD AIR IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART OF THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AFTER SEVERAL HOURS OF VIRGA...FIRST BANDS OF PRECIP (SNOW) HAVE ARRIVED ACROSS NORTHWEST/WEST CENTRAL/CENTRAL MOUNTAINS AND LAUREL HIGHLANDS LATE THIS MORNING. SOME QUICK MODERATE RATES HAVE BEEN NOTED AROUND ERIE AND BAND IS INTENSIFYING AS IT PUSHES EASTWARD. A QUICK 1 TO LOCALLY 2 INCHES WILL ACCUMULATE IN SPOTS BEFORE THE INITIAL INTENSE SNOW BAND MOVES EAST OF THE LAUREL HIGHLANDS AND SOUT CENTRAL MOUNTAINS. THE SOUTHERN THIRD OF CENTRAL PA WILL LIKELY THEN SEE A SEVERAL HOUR LULL IN PRECIP LATER THIS AFTERNOON...WHILE THE NORTH TRANSITIONS TO SLEET AND THEN FREEZING RAIN. NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE...BUT CONCERNED THAT WE`LL EXCEED ADVISORY CRITERIA FOR ICE LATER TONIGHT NORTH OF INTERSATE 80. SREF THREATS PAGE INDICATE 70-80% CONFIDENCE IN .20-.30" OR MORE OF ICE AND SUCCESSIVE HRRR RUNS CONTINUE TO DELAY WARMING AT THE END OF ITS 15-HOUR WINDOW...MEANING THAT MUCH OF NORTH CENTRAL PA WILL LIKELY NEVER RISE ABOVE FREEZING. CRITICAL TIMEFRAME WILL BE BETWEEN 21Z AND 04Z...AND MAY BE A WHITES OF THEIR EYES DECISION BASED ON RADAR EVOLUTION AND ADJUSTMENTS OF HRW-ARW AND HRRR CONSENSUS LATE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... PROLONGED ICE ACCRETION IS THE MAIN THREAT TONIGHT THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE /AND TO A LESSER DEGREE ACROSS THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY THE COATING TO 1 INCH OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW IN MOST AREAS (WITH UP TO 3 INCHES NORTH). THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE 80. WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET ACCUM...FOLLOWED BY FREEZING RAIN...GENERALLY FROM MIDDAY TODAY THROUGH THE EARLY MORNING HOURS ON WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS. MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN. SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA. HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY 3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN PORTIONS OF THE CWA. WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... CONDITIONS WILL QUICKLY DETERIORATE FROM WEST TO EAST AS MODERATE SNOW BANDS CROSS THROUGH THE CENTRAL AND NORTH CENTRAL MOUNTAINS THROUGH MIDDAY AND EARLY AFTERNOON HOURS. WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A TRANSITION TO A WINTRY MIX/FREEZING RAIN EVENT BY MID TO LATE AFTERNOON INTO THE EARLY EVENING...BEFORE CHANGING TO RAIN /FZRA NORTH/ LATE TONIGHT INTO EARLY WED AS HEAVIER PRECIP GRADUALLY TAPERS OFF. WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB WINDS INCREASE TO AROUND 50 KTS. LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW AND SIGNIFICANT FREEZING RAIN AS WELL. OUTLOOK... WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN THE DAY. WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE SOUTH. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST WEDNESDAY FOR PAZ006-011-012-018-037-041-042. WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR PAZ004- 005-010-017-024>026-033>035. WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059- 063>066. && $$ SYNOPSIS...DEVOIR/LAMBERT NEAR TERM...DEVOIR/LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
736 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE CENTERED OVER THE THE POCONO MOUNTAINS EARLY TODAY WILL DRIFT EAST TO THE SOUTHERN NEW ENGLAND COAST BY THIS AFTERNOON. AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES WILL MOVE QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A SURGE OF DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE COLD AIR IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART OF THE WEEKEND. && .NEAR TERM /UNTIL NOON TODAY/... SFC HIGH PRESSURE /1030 MB/ WAS CENTERED OVER NORTHEASTERN PENNSYLVANIA AND WILL BE DRIFTING EAST ACROSS THE LOWER HUDSON RIVER VALLEY DURING THE LATE MORNING HOURS. CIRRUS SHIELD HAS OVERSPREAD ALL OF THE CWA AND THICKENED-UP SUBSTANTIALLY OVER THE PAST FEW HOURS. REGIONAL 88D MOSAIC LOOP SHOWS PLENTY OF 10-20 DBZ RETURNS MOVING QUICKLY EAST INTO THE WESTERN PORTIONS OF OUR CWA.HOWEVER...SFC OBS CONFIRM NOTHING MORE THAN A FEW FLURRIES OR LIGHT SLEET PELLETS REACHING THE GROUND ALL THE WAY BACK THROUGH OHIO AND WVA. EXPECT CONDITIONS TO CHANGE RATHER QUICKLY LATE THIS MORNING AND EARLY THIS AFTERNOON /PER LATEST RAP AND HRRR/ AS AN ANOMALOUSLY STRONG 50-60 KT 850 JET /SREF/ TRANSPORTS A PLUME OF DEEP MOISTURE UP AND OVER THIS DOME OF LLVL COLD AIR. ONLY SOME MINOR CHANGES /UPWARD ADJUSTMENTS/ WERE MADE TO THE POPS FOR TODAY WITH LITTLE OR NO CHANGE IN THE ONSET OF THE PRECIP. EARLY MORNING LOWS WITH WINDS LIGHT AND VARIABLE WERE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO ACROSS THE NRN MTNS...IN THE LOWER TO MID TEENS THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION OF THE STATE...AND UPPER TEENS TO AROUND 20F IN THE SOUTHEAST. STILL EXPECT PRECIP ONSET FROM THE SOUTHWEST TO HOLD OFF UNTIL AFTER 15Z/10AM. && .SHORT TERM /NOON TODAY THROUGH 6 PM WEDNESDAY/... CONDITIONS WILL GO DOWNHILL FAIRLY QUICKLY TODAY WITH AN ANTICYCLONIC ARC OF DEEP MOISTURE FROM BAJA MONSOONAL FLOW ADVECTING THROUGH THE OHIO VALLEY AND ARRIVING INTO/BLOSSOMING OVER THE ALLEGHENIES BY LATE THIS MORNING IN THE FORM OF SNOW INITIALLY...SPREADING EASTWARD ACROSS MY CWA THROUGH THE MIDDAY AND EARLY AFTERNOON HOURS. VERY MILD UPPER BOUNDARY LAYER FLOW WILL BRING A QUICK MIX AND EVENTUAL CHANGEOVER TO FREEZING RAIN FOR ALL AS THE DAY PROGRESSES. THERE MAY BE A COMPLETE CHANGEOVER TO RAIN ACROSS THE FAR SOUTH AND SOUTHEAST. CONSENSUS BLEND OF 00Z-06Z OPERATIONAL MODELS AND ENS GUIDANCE IS STILL CONSISTENT WITH PREVIOUS SOLUTIONS FOR AN INITIAL FEW TO SEVERAL HOUR PERIOD OF SNOW/SLEET THIS AFTERNOON...FOLLOWED BY A SIGNIFICANT BOUT OF MIXED PRECIP/FREEZING RAIN LATER THIS AFTERNOON THROUGH EARLY TONIGHT. OVERALL IT APPEARS THAT PROLONGED ICE ACCRETION IS THE MAIN THREAT THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE /AND TO A LESSER DEGREE ACROSS THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY THE COATING TO 1 INCH OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW IN MOST AREAS (WITH UP TO 3 INCHES NORTH). THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE 80. WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET ACCUM...FOLLOWED BY FREEZING RAIN...GENERALLY FROM MIDDAY TODAY THROUGH THE EARLY MORNING HOURS ON WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS. MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN. SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA. HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY 3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN PORTIONS OF THE CWA. WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... ONGOING VFR CONDITIONS AT 12Z WILL PERSIST INTO THE MID/LATE MORNING HOURS AS HIGH PRESSURE QUICKLY CEDES TO AN APPROACHING WINTER STORM SYSTEM. WINDS THROUGH MID MORNING WILL BE LESS THAN 5 MPH. A FAST MOVING STORM SYSTEM WILL LIFT ACROSS THE GREAT LAKES...AND QUICKLY SPREAD SNOW/SLEET INTO WESTERN SECTIONS BY NOON AND ACROSS ALL OF CENTRAL PA BY MID AFTERNOON. WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A TRANSITION TO A WINTRY MIX/FREEZING RAIN EVENT BY LATE AFTERNOON INTO THE EARLY EVENING...BEFORE CHANGING TO RAIN /FZRA EAST/ LATE TONIGHT INTO EARLY WED AS HEAVIER PRECIP GRADUALLY TAPERS OFF. WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB WINDS INCREASE TO AROUND 50 KTS. LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW AND SIGNIFICANT FREEZING RAIN AS WELL. OUTLOOK... WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN THE DAY. WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE SOUTH. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST WEDNESDAY FOR PAZ006-011-012-018-037-041-042. WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST WEDNESDAY FOR PAZ004-005-010-017-024>026-033>035. WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059- 063>066. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
608 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE CENTERED OVER THE THE POCONO MOUNTAINS EARLY TODAY WILL DRIFT EAST TO THE SOUTHERN NEW ENGLAND COAST BY THIS AFTERNOON. AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES WILL MOVE QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A SURGE OF DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE COLD AIR IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART OF THE WEEKEND. && .NEAR TERM /UNTIL NOON TODAY/... SFC HIGH PRESSURE /1030 MB/ WAS CENTERED OVER NORTHEASTERN PENNSYLVANIA AND WILL BE DRIFTING EAST ACROSS THE LOWER HUDSON RIVER VALLEY DURING THE LATE MORNING HOURS. CIRRUS SHIELD HAS OVERSPREAD ALL OF THE CWA AND THICKENED-UP SUBSTANTIALLY OVER THE PAST FEW HOURS. REGIONAL 88D MOSAIC LOOP SHOWS PLENTY OF 10-20 DBZ RETURNS MOVING QUICKLY EAST INTO THE WESTERN PORTIONS OF OUR CWA.HOWEVER...SFC OBS CONFIRM NOTHING MORE THAN A FEW FLURRIES OR LIGHT SLEET PELLETS REACHING THE GROUND ALL THE WAY BACK THROUGH OHIO AND WVA. EXPECT CONDITIONS TO CHANGE RATHER QUICKLY LATE THIS MORNING AND EARLY THIS AFTERNOON /PER LATEST RAP AND HRRR/ AS AN ANOMALOUSLY STRONG 50-60 KT 850 JET /SREF/ TRANSPORTS A PLUME OF DEEP MOISTURE UP AND OVER THIS DOME OF LLVL COLD AIR. ONLY SOME MINOR CHANGES /UPWARD ADJUSTMENTS/ WERE MADE TO THE POPS FOR TODAY WITH LITTLE OR NO CHANGE IN THE ONSET OF THE PRECIP. EARLY MORNING LOWS WITH WINDS LIGHT AND VARIABLE WERE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO ACROSS THE NRN MTNS...IN THE LOWER TO MID TEENS THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION OF THE STATE...AND UPPER TEENS TO AROUND 20F IN THE SOUTHEAST. STILL EXPECT PRECIP ONSET FROM THE SOUTHWEST TO HOLD OFF UNTIL AFTER 15Z/10AM. && .SHORT TERM /NOON TODAY THROUGH 6 PM WEDNESDAY/... CONDITIONS WILL GO DOWNHILL FAIRLY QUICKLY TODAY WITH AN ANTICYCLONIC ARC OF DEEP MOISTURE FROM BAJA MONSOONAL FLOW ADVECTING THROUGH THE OHIO VALLEY AND ARRIVING INTO/BLOSSOMING OVER THE ALLEGHENIES BY LATE THIS MORNING IN THE FORM OF SNOW INITIALLY...SPREADING EASTWARD ACROSS MY CWA THROUGH THE MIDDAY AND EARLY AFTERNOON HOURS. VERY MILD UPPER BOUNDARY LAYER FLOW WILL BRING A QUICK MIX AND EVENTUAL CHANGEOVER TO FREEZING RAIN FOR ALL AS THE DAY PROGRESSES. THERE MAY BE A COMPLETE CHANGEOVER TO RAIN ACROSS THE FAR SOUTH AND SOUTHEAST. CONSENSUS BLEND OF 00Z-06Z OPERATIONAL MODELS AND ENS GUIDANCE IS STILL CONSISTENT WITH PREVIOUS SOLUTIONS FOR AN INITIAL FEW TO SEVERAL HOUR PERIOD OF SNOW/SLEET THIS AFTERNOON...FOLLOWED BY A SIGNIFICANT BOUT OF MIXED PRECIP/FREEZING RAIN LATER THIS AFTERNOON THROUGH EARLY TONIGHT. OVERALL IT APPEARS THAT PROLONGED ICE ACCRETION IS THE MAIN THREAT THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE /AND TO A LESSER DEGREE ACROSS THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY THE COATING TO 1 INCH OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW IN MOST AREAS (WITH UP TO 3 INCHES NORTH). THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE 80. WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET ACCUM...FOLLOWED BY FREEZING RAIN...GENERALLY FROM MIDDAY TODAY THROUGH THE EARLY MORNING HOURS ON WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS. MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN. SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA. HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY 3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN PORTIONS OF THE CWA. WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS WILL PERSIST INTO THE MID/LATE MORNING HOURS AS HIGH PRESSURE QUICKLY CEDES TO AN APPROACHING WINTER STORM SYSTEM. WINDS THROUGH MID MORNING WILL BE LESS THAN 5 MPH. A FAST MOVING SYSTEM MOVING ACROSS THE GREAT LAKES WILL QUICKLY SPREAD SNOW/SLEET INTO WESTERN SECTIONS BY NOON AND ACROSS ALL OF CENTRAL PA BY MID AFTERNOON. WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A TRANSITION TO A WINTRY MIX/FREEZING RAIN EVENT BY LATE AFTERNOON INTO THE EARLY EVENING...BEFORE CHANGING TO RAIN /FZRA EAST/ LATE TONIGHT INTO EARLY WED. WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB WINDS INCREASE TO AROUND 50 KTS. LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW AND SIGNIFICANT FREEZING RAIN AS WELL. OUTLOOK... WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN THE DAY. WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE SOUTH. THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST WEDNESDAY FOR PAZ006-011-012-018-037-041-042. WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST WEDNESDAY FOR PAZ004-005-010-017-024>026-033>035. WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059- 063>066. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...RXR
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1023 PM EST WED MAR 4 2015 .DISCUSSION...TEMPERATURES FALLING STEADILY THIS EVENING...BUT STILL WELL ABOVE FREEZING EVEN ACROSS EASTERN COUNTIES OF THE CUMBERLAND PLATEAU. THE NAM MODEL AND LATEST RAP SEEM TO HAVE A GOOD HANDLE ON THE ARRIVAL OF THE COLD AIR. THUS...THE WINTRY WEATHER TIMING LOOKS GOOD...SO I UPDATED THE WSW PRODUCT. MUCH OF THE RECENT HOUR OR TWO SPENT UPDATING THE FLOOD WATCH AND ASSOCIATED RIVER FLOOD WARNING PRODUCTS. WILL ALSO UPDATE THE AREAL FLOOD WARNINGS FOR WISE AND RUSSELL COUNTIES SHORTLY. OTHERWISE...PLAN TO FRESHEN THE HOURLY GRIDS AND ANY AFFECTED PRODUCTS BY 11 PM EST OR SO. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 34 37 21 42 / 90 100 10 10 KNOXVILLE MCGHEE TYSON AIRPORT, TN 32 35 16 38 / 90 100 10 10 OAK RIDGE, TN 30 33 16 38 / 90 100 10 10 TRI CITIES AIRPORT, TN 32 35 12 34 / 90 100 10 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...WINTER WEATHER ADVISORY FROM 4 AM TO 4 PM EST THURSDAY FOR ANDERSON-BLOUNT SMOKY MOUNTAINS-BRADLEY-COCKE SMOKY MOUNTAINS-GRAINGER-HAMBLEN-HAMILTON-HAWKINS-JEFFERSON- JOHNSON-KNOX-LOUDON-MCMINN-MEIGS-NW BLOUNT-NORTH SEVIER- NORTHWEST CARTER-NORTHWEST COCKE-NORTHWEST GREENE-NORTHWEST MONROE-SEVIER SMOKY MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-SULLIVAN-UNICOI-UNION-WASHINGTON TN-WEST POLK. FLOOD WATCH THROUGH THURSDAY EVENING FOR CAMPBELL-CLAIBORNE- HANCOCK-MORGAN-SCOTT TN. WINTER STORM WARNING UNTIL 4 PM EST THURSDAY FOR CAMPBELL- CLAIBORNE-HANCOCK-MORGAN-SCOTT TN. WINTER STORM WARNING FROM 4 AM EST /3 AM CST/ TO 4 PM EST /3 PM CST/ THURSDAY FOR BLEDSOE-MARION-RHEA-ROANE-SEQUATCHIE. VA...FLOOD WATCH THROUGH THURSDAY EVENING FOR LEE-RUSSELL-SCOTT- WASHINGTON-WISE. WINTER STORM WARNING UNTIL 4 PM EST THURSDAY FOR LEE-RUSSELL- SCOTT-WASHINGTON-WISE. && $$ TG
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
925 PM CST WED MAR 4 2015 .UPDATE... SEE EVENING UPDATE. && .DISCUSSION... A COLD FRONT IS MOVING ACROSS SE TX AND WILL LIKELY CLEAR THE COAST BY 11 PM. TEMPERATURES ARE FALLING QUICKLY BEHIND THE BOUNDARY AND CALDWELL IS ALREADY DOWN TO 37 DEGREES. LEANED TOWARD THE RUC FOR HOURLY TEMPS OVERNIGHT SINCE IT IS THE ONLY MODEL REMOTELY CLOSE TO CURRENT OBS. HAVE SOME CONCERN THAT MODELS ARE NOT COLD ENOUGH AND THAT COULD BE A REAL PROBLEM OVER THE NORTHERN ZONES BY MORNING. WATER VAPOR IMAGERY SHOWS A DISTURBANCE OVER NORTHERN MEXICO. THIS FEATURE WILL APPROACH SE TX AROUND 09Z AND WILL GENERATE A SWATH OF PRECIPITATION ACROSS MOST OF SE TX. HIGH POPS ARE ALREADY IN PLACE BUT BUMPED UP QPF TOWARD THE COAST AND RAISED POPS FOR EARLY THURSDAY MORNING ALONG THE COAST. SINCE PRECIP WILL BE A BIT HEAVIER AND LAST A BIT LONGER THAN PREVIOUSLY FCST...HAVE MORE CONCERN THAT WINTER PRECIP MAY DEVELOP FOR A TIME OVER THE NORTHERN ZONES. AM HESITENT TO MAKE BIG CHANGES AT THIS TIME BUT RAP AND NAM FORECAST SOUNDINGS SHOW A FAIRLY DEEP FREEZING LAYER BETWEEN 500-3500 FEET WHICH APPEARS COLD ENOUGH TO CHANGE PRECIP TO SLEET. WILL BE WATCHING TRENDS VERY CLOSELY AND A WINTER WEATHER ADVISORY FOR THE NORTHERN ZONES IS NOT OUT OF THE QUESTION. WIND ADVISORY AND GALE WARNINGS LOOK ON TARGET SO NO CHANGES PLANNED. NEW ZONES OUT BY 945 PM. 43 && .PREV DISCUSSION... /ISSUED 540 PM CST WED MAR 4 2015/ DISCUSSION... SEE THE 00Z AVIATION DISCUSSION BELOW. 40 AVIATION... THE COLD FRONT HAS ALREADY PUSHED THROUGH KCLL AND KUTS AT 2330Z. EXPECT THE FRONT TO MOVE THROUGH KCXO BY 01Z...THE METRO HOUSTON AIRPORTS BETWEEN 02Z AND 04Z...KLBX BY 04Z...AND KGLS BY 05Z. VFR CONDITIONS AHEAD OF THE FRONT WILL BE OFFSET BY ISOLATED SHOWERS. CONDITIONS BEHIND THE FRONT WILL DETERIORATE...WITH IFR CONDITIONS WITH NORTH WINDS OF 20 TO 30 KNOTS QUICKLY DEVELOPING. GUSTS MAY REACH TO NEAR 35 KNOTS OVERNIGHT TONIGHT INTO THURSDAY MORNING. BEST RAIN CHANCES WILL BE BEHIND THE FRONT. THE RAIN MAY CHANGE OVER OR MIX WITH SLEET OR FREEZING RAIN BEFORE ENDING AT KCLL AND KUTS BETWEEN ABOUT 11Z AND 15Z. CONDITIONS LOOKED TOO WARM FURTHER TO THE SOUTH FOR WINTRY PRECIPITATION. THE RAIN SHOULD END BY MID MORNING...ALTHOUGH A LINGERING SHOWER WILL BE POSSIBLE THROUGH THE EARLY AFTERNOON. THE IFR CONDITIONS AND GUSTY WINDS WILL BE SLOW TO SUBSIDE. HOWEVER...THE NAMBUFR WAS FORECASTING A RETURN TO VFR FROM ABOUT KHOU AND KSGR NORTHWARD AFTER ABOUT 21Z. 40 PREV DISCUSSION... /ISSUED 344 PM CST WED MAR 4 2015/ DISCUSSION... THE COLD FRONT IS AT OUR NORTHERN BORDER THIS AFTERNOON. AT 3PM THE TEMPERATURE IN COLLEGE STATION WAS 75 DEGREES WHILE IN HEARNE THE TEMPERATURE WAS 57 DEGREES. WINDS WILL PICK UP AND TEMPERATURES WILL FALL QUICKLY WITH THE PASSAGE OF THE FRONT. TIMING REMAINS ROUGHLY THE SAME WITH THE FRONT EXPECTED TO MOVE INTO THE METRO AREA AROUND 7PM AND OFF THE COAST AROUND MIDNIGHT. WIDESPREAD LIGHT RAIN IS EXPECTED WITH PERHAPS A RUMBLE OF THUNDER ACROSS OUR NORTHWESTERN COUNTIES WHERE A FEW ISOLATED THUNDERSTORMS MAY OCCUR OVERNIGHT. LITTLE CHANGE TO THINKING FOR ANY WINTER WEATHER ACROSS SOUTHEAST TEXAS. WITH TEMPERATURES CURRENTLY IN THE MID 70S THE GROUND WILL REMAIN QUITE WARM EVEN INTO THURSDAY MORNING. ATMOSPHERIC PROFILES ARE COOL ENOUGH TOMORROW MORNING TO SUPPORT A MIX OF RAIN AND SLEET ACROSS OUR FAR NORTHERN COUNTIES AND A FEW SLICK SPOTS ARE POSSIBLE. AREA OF GREATEST CONCERN WOULD BE PARTS OF HOUSTON AND TRINITY COUNTIES BETWEEN 7-10 AM...ALTHOUGH LITTLE TO NO IMPACTS ARE EXPECTED. TEMPERATURES WILL BE COLDER THURSDAY NIGHT INTO FRIDAY BUT WITH PRECIPITATION CLEARING THE REGION BY THURSDAY AFTERNOON NO TRAVEL IMPACTS ARE EXPECTED. A LIGHT FREEZE IS POSSIBLE AS FAR SOUTH AS THE COASTAL COUNTIES FRIDAY MORNING AND THE I-10 CORRIDOR SATURDAY SO SENSITIVE PLANTS SHOULD REMAIN COVERED INTO THE WEEKEND. RAIN CHANCES RETURN BY SUNDAY AS THE UPPER TROUGH SLOWLY BEGINS TO MOVE OFF TO THE EAST. BEST RAIN CHANCES WILL LIE ALONG THE COAST AND OFFSHORE THROUGH EARLY NEXT WEEK. TEMPERATURES WILL SLOWLY WARM WITH HIGHS IN THE MID 60S AND LOWS IN THE UPPER 40S BY THE MIDDLE OF NEXT WEEK. 38 MARINE... THE SEA FOG HAS RETURNED AND VTS AND PILOTS REPORTING SHUT OUT CONDITIONS IN LOWER GALVESTON BAY AND ACROSS MATAGORDA BAY. THE FOG SHOULD CONTINUE UNTIL THE ARCTIC FRONT ARRIVES...CLOSE TO 10 PM MATAGORDA AND 11 PM FOR GALVESTON. GALE CONDITIONS TONIGHT AFTER MIDNIGHT WITH 25-35 KNOT SUSTAINED WINDS AND GUSTS 40-45 KNOTS. SEAS MAY BUILD TO 15 FEET WELL OFFSHORE WITH VERY ROUGH CONDITIONS ON THE BAYS. LOW WATER ADVISORY WITH VERY STRONG CURRENTS SQUEEZING OUT THURSDAY MORNING IN THE LOWER BAY. GALE CONDITIONS SHOULD LESSEN THURSDAY AFTERNOON BAYS AND NEARSHORE FIRST. MAY NEED TO EXTEND THE GALE WARNING FOR THE 20-60NM WATERS THURSDAY AFTERNOON. 45 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 33 37 27 47 32 / 90 40 10 10 10 HOUSTON (IAH) 37 41 29 49 34 / 80 60 10 10 10 GALVESTON (GLS) 42 43 35 47 41 / 60 50 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...WIND ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...FORT BEND... GALVESTON...HARRIS...JACKSON...MATAGORDA...WHARTON. GM...LOW WATER ADVISORY FROM NOON TO 2 PM CST THURSDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. GALE WARNING UNTIL NOON CST THURSDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. GALE WARNING FROM MIDNIGHT TONIGHT TO 3 PM CST THURSDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1112 PM CST MON MAR 2 2015 .DISCUSSION... SEE 06Z AVIATION DISCUSSION. && .AVIATION... POOR AVIATION CONDITIONS ARE EXPECTED AGAIN OVERNIGHT INTO TUESDAY MORNING. FCST SOUNDINGS AND HRRR VSBY PROGS SHOW STRONG POTENTIAL FOR DENSE FOG OVERNIGHT WITH VISIBILITIES DROPPING TO 1/4 MILE OVER ALL TAF SITES. CIGS WILL ALSO LOWER TO BELOW 200 FEET AT ALL TAF SITES AS WELL. SLOW IMPROVEMENT IS EXPECTED TUESDAY MORNING AFTER 16Z WITH MVFR CONDS EXPECTED TO OCCUR BRIEFLY ON TUESDAY AFTN. WINDS WILL REMAIN LIGHT OVERNIGHT AND GRADUALLY VEER TO THE E-SE BY MORNING. S-SE WINDS EXPECTED ON TUESDAY AFTN AND SPEEDS WILL PROBABLY GET A BIT GUSTY OVER THE WESTERN TAF SITES DURING THE AFTN. 43 && .PREV DISCUSSION... /ISSUED 731 PM CST MON MAR 2 2015/ UPDATE... ISSUED A DENSE FOG ADVISORY FOR THE REGION. SEA FOG AT THE COAST ALREADY MOVING ONSHORE AND VISBY THERE FALLING. OVER THE NORTHERN COUNTIES 1/2 TO 2 MILES IS COMMON WHILE IN BETWEEN 5-9 MILES IS MORE COMMON. AS WE COOL DOWN AND WINDS BECOME MORE EAST AND SOUTHEAST AM EXPECTING VISBY TO DROP AND DENSE TO BECOME WIDESPREAD. WARM FRONT MOVES INLAND TOMORROW MORNING AND SOME IMPROVEMENT IN VISBY SHOULD OCCUR...COASTAL AREAS WILL BE TRICKY DEPENDING ON TRAJECTORIES AND DURATION OVER THE COOLER SHELF WATERS. FOR NOW THE ADVISORY RUN THROUGH 10 AM. ALSO MADE SOME CHANGES TO THE GRIDS IN THE SHORT TERM TO LOWER TEMPERATURES UP NORTH AND INCREASE SKY COVER. 45 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 43 72 61 63 30 / 20 30 30 70 70 HOUSTON (IAH) 55 76 64 70 34 / 20 20 20 50 70 GALVESTON (GLS) 56 72 61 66 37 / 20 20 20 30 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS... COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS... HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA... MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER... WALLER...WASHINGTON...WHARTON. GM...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
139 PM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 138 PM EST TUESDAY... WITH TEMPERATURES RISING THIS AFTERNOON INTO THIS EVENING. THE THREAT FOR WIDESPREAD ICING PROBLEMS HAS ENDED...THUS THE WINTER WEATHER ADVISORY IS CANCELLED. SOME LIGHT RAIN AND PATCHES OF DRIZZLE ARE EXPECTED FOR THE THIS AFTERNOON. ISOLATED POCKETS OF ICE MAY BE POSSIBLE ON THE COLDEST SURFACES. DRIVER SHOULD WATCH FOR SLICK ICY SPOTS ON ROADWAYS. AS OF 1000 AM EST TUESDAY... CANCELLED THE WINTER WEATHER ADVISORY MAINLY WEST OF I77 WHERE TEMPERATURES WERE ABOVE FREEZING MARK AND EXPECTED TO REMAIN AS SUCH...AND RADAR COVERAGE IS LIGHT. STILL CONCERN OVER DIABATIC COOLING OF TEMPERATURES WITH LIGHT PRECIPITATION...THUS WILL HOLD WITH REST OF WINTER WEATHER ADVISORY AT THIS TIME. MODIFIED POPS WITH LATEST RADAR TRENDS. SHAPED MORNING TEMPERATURES WITH SFC OBS AND LATEST MODEL TRENDS. MORE CHANGES LATER THIS MORNING IN THE ACTIVE WEATHER PATTERN . AS OF 415 AM EST TUESDAY... LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN 8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL. WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING. TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE NORTHWEST COUNTY WARNING AREA INCREASES. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 430 AM EST TUESDAY... EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY ABOVE NORMAL FOR EARLY MARCH. DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND DOWNSLOPE. DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN. AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA. THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON. BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY. RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS. PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE APPALACHIANS. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 145 PM EST MONDAY... HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY. THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE. SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST SIDE OF AN APPROACHING SHORTWAVE TROUGH. OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO MONDAY. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... AS OF 1230 PM EST TUESDAY... MVFR CONDITIONS WITH POCKETS OF IFR IN PRECIPITATION...CLOUDS AND FOG THIS AFTERNOON INTO TONIGHT. STRONG SOUTH TO SOUTHWEST WINDS ALOFT WILL BRING ABUNDANT MOISTURE INTO THE REGION THIS AFTERNOON INTO TONIGHT. TEMPERATURES WILL SLOWLY RISE THIS AFTERNOON INTO TONIGHT. THIS WILL END THE THREAT FOR FREEZING RAIN/FREEZING DRIZZLE ACROSS OUR AREA. TRIMMED BACK AND NARROWED THE WINDOW FOR LOW LEVEL WIND SHEAR IN THE TAFS FOR TONIGHT. CEILINGS AND VISIBILITIES WILL BE IFR TO LIFR FOR MUCH OF THE AREA IN LOW CLOUDS AND FOG THIS EVENING INTO WEDNESDAY MORNING. ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION WILL TRACK FROM THE CENTRAL PLAINS INTO SOUTHEAST CANADA BY WEDNESDAY. THIS WILL RESULT IN WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA WEDNESDAY AND THURSDAY WITH ABUNDANT RAIN. A COLD FRONT WILL CROSS THROUGH THE AREA ON WEDNESDAY. MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE TAF PERIOD. EXTENDED FORECAST... WINTER PRECIPITATION IS LIKELY BEHIND THE FRONT WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME THE MOST LIKELY PRECIPITATION TYPES ARE SNOW AND SLEET. FRIDAY AND SATURDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. && .HYDROLOGY... AS OF 300 PM EST MONDAY LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3 INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW WATER AND IN MOST PLACES ZERO. THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS POINT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...NF LONG TERM...DS AVIATION...AMS/KK HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1010 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM EST TUESDAY... CANCELLED THE WINTER WEATHER ADVISORY MAINLY WEST OF I77 WHERE TEMPERATURES WERE ABOVE FREEZING MARK AND EXPECTED TO REMAIN AS SUCH...AND RADAR COVERAGE IS LIGHT. STILL CONCERN OVER DIABATIC COOLING OF TEMPERATURES WITH LIGHT PRECIPITATION...THUS WILL HOLD WITH REST OF WINTER WEATHER ADVISORY AT THIS TIME. MODIFIED POPS WITH LATEST RADAR TRENDS. SHAPED MORNING TEMPERATURES WITH SFC OBS AND LATEST MODEL TRENDS. MORE CHANGES LATER THIS MORNING IN THE ACTIVE WEATHER PATTERN . AS OF 415 AM EST TUESDAY... LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN 8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL. WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING. TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE NORTHWEST COUNTY WARNING AREA INCREASES. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 430 AM EST TUESDAY... EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY ABOVE NORMAL FOR EARLY MARCH. DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND DOWNSLOPE. DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN. AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA. THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON. BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY. RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS. PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE APPALACHIANS. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 145 PM EST MONDAY... HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY. THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE. SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST SIDE OF AN APPROACHING SHORTWAVE TROUGH. OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO MONDAY. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... AS OF 700 AM EST TUESDAY... CEILINGS WERE LOWERING ACROSS THE REGION...DOWN TO MVFR THIS MORNING AND IFR THIS AFTERNOON. STRONG SOUTH TO SOUTHWEST WINDS ALOFT WILL BRING ABUNDANT MOISTURE INTO THE REGION TODAY. EXPECT SCATTERED LIGHT RAIN AND FREEZING RAIN THROUGH NOON. TEMPERATURES WILL BE NEARLY STEADY TODAY THEN RISE TONIGHT. MEDIUM CONFIDENCE AS TO WHEN THE THREAT OF FREEZING RAIN ENDS...ESPECIALLY AT KLYH TODAY. BUFKIT AND MET TEMPERATURE GUIDANCE SUGGESTED THE THREAT OF FREEZING RAIN OR FREEZING DRIZZLE MAY CONTINUE AT KLYH UNTIL 21Z/4PM. MAINTAINED LOW LEVEL WIND SHEAR IN THE TAFS FOR TONIGHT. CEILINGS AND VISIBILITIES WILL BE IFR TO LIFR FOR MUCH OF THE AREA. EXTENDED FORECAST... ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION WILL TRACK FROM THE CENTRAL PLAINS INTO SOUTHEAST CANADA BY WEDNESDAY. THIS WILL RESULT IN WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA WEDNESDAY AND THURSDAY WITH ABUNDANT RAIN. A COLD FRONT WILL CROSS THROUGH THE AREA ON WEDNESDAY. WINTER PRECIPITATION IS LIKELY BEHIND THE FRONT WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME THE MOST LIKELY PRECIPITATION TYPES ARE SNOW AND SLEET. FRIDAY AND SATURDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. && .HYDROLOGY... AS OF 300 PM EST MONDAY LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3 INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW WATER AND IN MOST PLACES ZERO. THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS POINT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR VAZ011-013-014-017>019-022-023-032>034-043-045. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR VAZ020-024-035-046-047. NC...NONE. WV...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR WVZ043-044-507-508. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...NF LONG TERM...DS AVIATION...AMS HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
704 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 415 AM EST TUESDAY... LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN 8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL. WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING. TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE NORTHWEST COUNTY WARNING AREA INCREASES. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 430 AM EST TUESDAY... EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY ABOVE NORMAL FOR EARLY MARCH. DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND DOWNSLOPE. DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN. AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA. THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON. BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY. RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS. PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE APPALACHIANS. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 145 PM EST MONDAY... HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY. THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE. SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST SIDE OF AN APPROACHING SHORTWAVE TROUGH. OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO MONDAY. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 700 AM EST TUESDAY... CEILINGS WERE LOWERING ACROSS THE REGION...DOWN TO MVFR THIS MORNING AND IFR THIS AFTERNOON. STRONG SOUTH TO SOUTHWEST WINDS ALOFT WILL BRING ABUNDANT MOISTURE INTO THE REGION TODAY. EXPECT SCATTERED LIGHT RAIN AND FREEZING RAIN THROUGH NOON. TEMPERATURES WILL BE NEARLY STEADY TODAY THEN RISE TONIGHT. MEDIUM CONFIDENCE AS TO WHEN THE THREAT OF FREEZING RAIN ENDS...ESPECIALLY AT KLYH TODAY. BUFKIT AND MET TEMPERATURE GUIDANCE SUGGESTED THE THREAT OF FREEZING RAIN OR FREEZING DRIZZLE MAY CONTINUE AT KLYH UNTIL 21Z/4PM. MAINTAINED LOW LEVEL WIND SHEAR IN THE TAFS FOR TONIGHT. CEILINGS AND VISIBILITIES WILL BE IFR TO LIFR FOR MUCH OF THE AREA. EXTENDED FORECAST... ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION WILL TRACK FROM THE CENTRAL PLAINS INTO SOUTHEAST CANADA BY WEDNESDAY. THIS WILL RESULT IN WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA WEDNESDAY AND THURSDAY WITH ABUNDANT RAIN. A COLD FRONT WILL CROSS THROUGH THE AREA ON WEDNESDAY. WINTER PRECIPITATION IS LIKELY BEHIND THE FRONT WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME THE MOST LIKELY PRECIPITATION TYPES ARE SNOW AND SLEET. FRIDAY AND SATURDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. && .HYDROLOGY... AS OF 300 PM EST MONDAY LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3 INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW WATER AND IN MOST PLACES ZERO. THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS POINT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR VAZ011-013-014-017>019-022-023-032>034-043-045. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ007-009-010-012-015-016. WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST THIS AFTERNOON FOR VAZ020-024-035-046-047. NC...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NCZ001-002-018. WV...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR WVZ043-044-507-508. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ042. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...NF LONG TERM...DS AVIATION...AMS HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
531 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 415 AM EST TUESDAY... LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN 8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL. WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING. TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE NORTHWEST COUNTY WARNING AREA INCREASES. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 430 AM EST TUESDAY... EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY ABOVE NORMAL FOR EARLY MARCH. DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND DOWNSLOPE. DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN. AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA. THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON. BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY. RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS. PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE APPALACHIANS. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 145 PM EST MONDAY... HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY. THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE. SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST SIDE OF AN APPROACHING SHORTWAVE TROUGH. OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO MONDAY. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... AS OF 1250 AM EST TUESDAY... MVFR CIGS WILL START PROGRESSES NORTHEAST ACROSS THE REGION IN CONJUNCTION WITH A WARM FRONT HEADING TOWARD THE AREA. ALONG WITH THE FRONT WILL COME LIGHT WINTRY PRECIPITATION IN THE FORM OF PATCHY LIGHT FREEZING RAIN AND SLEET. BY DAYBREAK TUESDAY...MANY AREAS WILL HAVE LOWERED TO LIFR/IFR CIGS AND MVFR VSBYS DUE TO THE PRECIPITATION AND MIST. THE BULK OF THE WINTRY PRECIPITATION WILL BE CONFINED TO NORTH A LINE FROM KBLF-KROA-KLYH DURING THE LATE MORNING. BY THE AFTERNOON...SURFACE TEMPERATURES SHOULD BE MILD ENOUGH FOR A WIDESPREAD AREA OF RAIN. WINDS WILL REMAIN LIGHT THROUGH THE NIGHT AND GRADUALLY VEER TO THE SOUTHEAST. ON TUESDAY...WINDS WILL INCREASE DURING THE DAY FROM THE SOUTHWEST...AND WINDS AT 850 MB WILL INCREASE TO AROUND 45 TO 50 KTS. LOW LEVEL WIND SHEAR WILL BE POSSIBLE DURING THE AFTERNOON...ESPECIALLY AT TERMINALS AT HIGHER ELEVATION. MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE PERIOD. EXTENDED FORECAST... ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION WILL TRACK FROM THE CENTRAL PLAINS INTO NEW ENGLAND TUESDAY NIGHT INTO WEDNESDAY. THIS WILL RESULT IN SUB-VFR CONDITIONS WEDNESDAY AND THURSDAY WITH WIDESPREAD RAIN AHEAD OF THE FRONT ON WEDNESDAY AND WINTER PRECIPITATION BEHIND THE FRONT WEDNESDAY NIGHT AND THURSDAY. FRIDAY SHOULD SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. && .HYDROLOGY... AS OF 300 PM EST MONDAY LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3 INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW WATER AND IN MOST PLACES ZERO. THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS POINT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR VAZ011-013-014-017>019-022-023-032>034-043-045. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ007-009-010-012-015-016. WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST THIS AFTERNOON FOR VAZ020-024-035-046-047. NC...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NCZ001-002-018. WV...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR WVZ043-044-507-508. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ042. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...NF LONG TERM...DS AVIATION...AMS/DS/KK HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1252 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST INTO THE MID ATLANTIC REGION TONIGHT. MEANWHILE...A WARM FRONT WILL PUSH NORTH THROUGH THE AREA LATE TONIGHT INTO TUESDAY...THEN FOLLOWED BY A COLD FRONT TUESDAY NIGHT INTO WEDNESDAY. COLD HIGH PRESSURE WILL RETURN FOR THURSDAY INTO THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... AS OF 1000 PM EST MONDAY... 1033 MB SURFACE HIGH WAS CENTERED OVER OHIO. THIS HIGH WILL CONTINUE TO DRIFT EAST OVERNIGHT PROVIDING MAINLY DRY CONDITIONS. A STATIONARY FRONT WAS OVER THE DEEP SOUTH...EXTENDING FROM CENTRAL SOUTH CAROLINA SOUTHWEST TO JACKSON MS. THIS STATIONARY FROM IS EXPECTED TO BEGIN MOVING NORTH OVERNIGHT AS A WARM FRONT RESULTING IN THE RETURN OF LOW LEVEL MOISTURE TO THE AREA BY DAYBREAK TUESDAY. QUESTION TO BE ANSWERED IS WHETHER THERE WILL BE ENOUGH MOISTURE FOR PRECIPITATION. THE CLOSEST THING ON RADAR AT THE MOMENT IS OVER THE SOUTHERN APPALACHIANS BETWEEN ASHEVILLE NC AND ATLANTA GA. THE SURFACE HIGH WILL CERTAINLY BE IN A POSITION TO PROVIDE ENOUGH COLD AIR FOR A WINTRY FORM OF PRECIPITATION TUESDAY MORNING. THE QUESTION IS WHETHER THERE WILL BE ENOUGH DEPTH TO THE MOISTURE TO PRODUCE PRECIPITATION. BOTH THE HRRR AND RNKWRF SUGGEST ONLY TRACE AMOUNTS TO OCCUR BETWEEN NOW AND NOON TUESDAY WITH THE LARGER SCALE MODELS PRODUCING A FEW HUNDREDTHS OF AN INCH. TRACE ICE IS CERTAINLY ENOUGH TO BE A NUISANCE...BUT THIS IS NOT GOING TO BE A WIDESPREAD EVENT. THE MAIN PROBLEM WITH PRECIP PRODUCTION FOR TUESDAY IS THE LACK OF UPPER LEVEL MOISTURE WITHIN THE M8-M12 DEG C DENDRITIC GROWTH ZONE. FORECAST MODEL SOUNDINGS ARE DRY WITHIN THIS LAYER...ALL OF THE SATURATION TAKING PLACE IN A LOWER LAYER BETWEEN +3 DEG C AND -3 DEG C. UNLESS THERE IS SOME SEEDER FEEDER PROCESS THAT DEVELOPS INOF THE WARM FRONT...THE MODEL SOUNDINGS SUGGESTS THE PTYPE WILL BE EITHER DRIZZLE OR FREEZING DRIZZLE PENDING SURFACE TEMPERATURE AT THE TIME. THE CRITICAL WINDOW FOR THE FREEZING PRECIPITATION WILL BE DURING THE MORNING...SO STILL SEE THE NEED FOR WINTER WEATHER ADVISORIES TO ACCOUNT FOR THE POTENTIALLY LIGHT ICING THAT MAY OCCUR...KEEPING IN MIND THAT EVEN A VERY LIGHT COATING OF ICE ON AN UNTREATED SURFACE CAN POSE A TRAVEL/WALKING HAZARD. LOW TEMPERATURES OVERNIGHT WILL RANGE FROM THE MID 20S IN THE COLDEST VALLEYS TO THE LOWER 30S IN THE PIEDMONT. WARM AIR WILL MOVE IN FROM THE SOUTHWEST TUESDAY CHANGING PRECIPITATION OVER TO ALL LIQUID TUESDAY AFTERNOON. AREAS ACROSS THE NORTH AND NORTHEAST WILL BE THE SLOWEST TO TRANSITION. HIGH TEMPERATURES TUESDAY WILL RANGE FROM THE MID 30S IN THE NORTHEAST TO THE LOWER 50S IN THE SOUTHWEST. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... AS OF 330 PM EST MONDAY... COMPLICATED SHORT TERM FORECAST WITH MULTIPLE CONCERNS. TO BEGIN TUESDAY NIGHT...ANY REMNANTS OF EARLIER WEDGE WILL BE LONG GONE TO THE NORTHEAST WITH THE AREA SOLIDLY IN THE WARM SECTOR. TEMPERATURES WILL BE WELL ABOVE FREEZING AND CONTINUING TO RISE DURING THE OVERNIGHT HOURS ON THE HEELS OF A STRONG SOUTHWESTERLY LLJ. CONSEQUENTLY...ANY ASSOCIATED WARM FRONTAL PRECIPITATION WILL ALSO HAVE LIFTED WELL NORTHEAST OF THE REGION. NOW...THE ATTENTION SHIFTS TO THE ARCTIC FRONT APPROACHING FROM THE WEST. A BROAD UPPER RIDGE ACROSS THE CENTRAL/EASTERN GULF...590+ DM AT THAT...WILL AMPLIFY INTO THE SOUTHEAST WHILE A DEEP UPPER TROUGH DIGS INTO THE SOUTHERN PLAINS. A SIGNIFICANT SURGE OF ARCTIC AIR WILL PLUNGE INITIALLY SOUTH INTO THE CENTRAL/SOUTH CENTRAL U.S. AS THE ASSOCIATED ARCTIC FRONT SLOWS ITS PUSH INTO THE MID- ATLANTIC/SOUTHEAST STATES THANKS TO THE AFOREMENTIONED UPPER RIDGE AND THE APPALACHIAN MOUNTAINS. THIS HOLDS THE HEAVIEST RAINFALL WEST OF OUR CWA THROUGH WEDNESDAY MUCH OF THE DAY WEDNESDAY...MAINLY ACROSS THE OH/TN VALLEYS. FINALLY...WEDNESDAY AFTERNOON/EVENING...THE FRONT WILL BEGIN A BETTER SOUTHEASTWARD PUSH AS SHORT WAVE ENERGY KICKS OUT OF THE CENTRAL PLAINS. WOULD EXPECT HEAVIER RAIN TO MOVE INTO THE WESTERN PARTS OF THE CWA BY 00Z WED...THEN BEGIN TO SPREAD EASTWARD OVERNIGHT. MEANWHILE...PART OF THE UPPER TROUGH LAGS BEHIND AND SURFACE LOW PRESSURE DEVELOPS ACROSS THE SOUTHEAST STATES IN RESPONSE. THIS WILL FURTHER DELAY THE PUSH OF THE PRECIPITATION INTO/THROUGH THE CWA...BUT PERHAPS NOT THE SHALLOW COLD ARCTIC AIR ONCE IT MANGES TO CROSS THE APPALACHIANS. QUITE A VARIETY OF SOLUTIONS PRESENTED BY THE MODELS AND WPC AS TO THE WINTER WEATHER THREAT THURSDAY GIVEN THAT THIS IS FAR FROM A NORMAL SYNOPTIC SITUATION FOR A SNOW EVENT IN THIS REGION. THE BIG QUESTION IS NOT WHETHER OR NOT THERE WILL BE PRECIPITATION...BUT HOW QUICKLY WILL THE COLD AIR SPREAD INTO THE REGION BEHIND THE FRONT...BEFORE THE HEAVIER PRECIPITATION MOVES OUT...AND HOW QUICKLY WILL THE COLD AIR BECOME DEEP ENOUGH TO CHANGE THE PRECIPITATION TO SNOW. AM INCLINED AT THIS POINT TO THROW OUT RAIN TO FREEZING RAIN SCENARIOS...NOT ONLY BECAUSE IT IS NOT CLIMATOLOGICALLY OR SYNOPTICALLY FAVORABLE IN THIS SITUATION...BUT THINKING IS THAT COLD AIR WILL BECOME DEEP ENOUGH QUICKLY ENOUGH TO CHANGE RAIN OVER TO SNOW...OTHER THAN A BRIEF PERIOD OF SLEET ALONG THE LEADING EDGE OF THE CHANGEOVER. FURTHERMORE...GROUND TEMPS WILL NOT SUPPORT FZRA AT THE CHANGEOVER TIME AS THE SOUNDING COLUMN COOLS ISOTHERMALLY. FINALLY...THIS IS YET AGAIN A SIGNIFICANT ARCTIC AIR MASS...SO ONCE IT ENTERS THE REGION...COOLING WILL BE QUICK...ESPECIALLY WEST OF I-81. FOR SNOW AMOUNTS...A PRELIMINARY ESTIMATE...FAIRLY CONSISTENT WITH WPC WWD...IS 4-5 INCHES NORTH...2-4 INCHES CENTRAL/WESTERN AREAS...1-2 INCHES VA PIEDMONT...LITTLE TO NONE NC PIEDMONT. SEE THE HYDROLOGY SECTION BELOW FOR FURTHER DETAILS ON THE FLOOD THREAT ASSOCIATED WITH COMBINED RAINFALL AND SNOW MELT. DID ADVERTISE A PERIOD OF MODERATE RAIN WEDNESDAY EVENING FROM WEST TO EAST...BUT HAVE REDUCED THE TIME PERIOD OF SUCH COMPARED TO PREVIOUS FORECAST PACKAGES. TEMPERATURE WISE...A LOT OF NON-DIURNAL TEMPERATURE TRENDS THROUGH THIS FORECAST PERIOD. TEMPERATURES CONTINUING TO RISE TUESDAY NIGHT/WEDNESDAY MORNING AND REMAINING MILD/ABOVE FREEZING UNTIL THE ARCTIC FRONT ARRIVES IN THE WEST WEDNESDAY NIGHT. THE PIEDMONT WILL LIKELY REMAIN ABOVE FREEZING FROM TUESDAY AFTERNOON UNTIL THURSDAY MORNING. LIKEWISE...A NON-DIURNAL COOLING TREND EXPECTED THROUGHOUT THE DAY THURSDAY AS ARCTIC AIR SPREADS INTO THE REGION. THE GFS IN PARTICULAR SHOW SFC TEMPS BELOW ZERO IN OUR WESTERN COUNTIES BY FRIDAY MORNING. GIVEN THAT IT IS EARLY MARCH AND THE 850MB TEMPS ARE ONLY AROUND -16C...AS COMPARED TO -26C A COUPLE OF WEEKS AGO...I FIND THIS SOMEWHAT EXTREME. NONETHELESS...IT IS A VERY COLD AIR MASS AND WELL BELOW NORMAL FOR THIS TIME OF YEAR. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 145 PM EST MONDAY... HIGH PRESSURE WILL BUILD OVER THE REGION ON FRIDAY...AND BE IN CONTROL OF OUR WEATHER PATTERN THROUGH AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY. THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE. SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST SIDE OF AN APPROACHING SHORTWAVE TROUGH. OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO MONDAY. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 1250 AM EST TUESDAY... MVFR CIGS WILL START PROGRESSES NORTHEAST ACROSS THE REGION IN CONJUNCTION WITH A WARM FRONT HEADING TOWARD THE AREA. ALONG WITH THE FRONT WILL COME LIGHT WINTRY PRECIPITATION IN THE FORM OF PATCHY LIGHT FREEZING RAIN AND SLEET. BY DAYBREAK TUESDAY...MANY AREAS WILL HAVE LOWERED TO LIFR/IFR CIGS AND MVFR VSBYS DUE TO THE PRECIPITATION AND MIST. THE BULK OF THE WINTRY PRECIPITATION WILL BE CONFINED TO NORTH A LINE FROM KBLF-KROA-KLYH DURING THE LATE MORNING. BY THE AFTERNOON...SURFACE TEMPERATURES SHOULD BE MILD ENOUGH FOR A WIDESPREAD AREA OF RAIN. WINDS WILL REMAIN LIGHT THROUGH THE NIGHT AND GRADUALLY VEER TO THE SOUTHEAST. ON TUESDAY...WINDS WILL INCREASE DURING THE DAY FROM THE SOUTHWEST...AND WINDS AT 850 MB WILL INCREASE TO AROUND 45 TO 50 KTS. LOW LEVEL WIND SHEAR WILL BE POSSIBLE DURING THE AFTERNOON...ESPECIALLY AT TERMINALS AT HIGHER ELEVATION. MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE PERIOD. EXTENDED FORECAST... ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION WILL TRACK FROM THE CENTRAL PLAINS INTO NEW ENGLAND TUESDAY NIGHT INTO WEDNESDAY. THIS WILL RESULT IN SUB-VFR CONDITIONS WEDNESDAY AND THURSDAY WITH WIDESPREAD RAIN AHEAD OF THE FRONT ON WEDNESDAY AND WINTER PRECIPITATION BEHIND THE FRONT WEDNESDAY NIGHT AND THURSDAY. FRIDAY SHOULD SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. && .HYDROLOGY... AS OF 300 PM EST MONDAY LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3 INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW WATER AND IN MOST PLACES ZERO. THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS POINT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR VAZ018>020-022>024-034-035-045>047. WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009- 010-012-015-016. WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM EST THIS AFTERNOON FOR VAZ011-013-014-017-032-033-043. NC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NCZ001-002- 018. WV...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR WVZ507-508. WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ042. WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM EST THIS AFTERNOON FOR WVZ043-044. && $$ SYNOPSIS...KK/RAB NEAR TERM...KK/PM SHORT TERM...RAB LONG TERM...DS AVIATION...AMS/DS/KK HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1108 AM MST TUE MAR 3 2015 .UPDATE... ISSUED AT 1052 AM MST TUE MAR 3 2015 UPDATED WINTER WEATHER HEADLINES TO CONVERT THE WINTER STORM WARNING TO AN ADVISORY. SOME POCKETS OF BLOWING SNOW CONTINUE ALONG WITH SOME LIGHT SNOW SHOWER ACTIVITY THIS MORNING. THE NORTHERN STREAM DISTURBANCE WHICH IS CURRENTLY OVER WESTERN WYOMING WILL MOVE EASTWARD TODAY AND TONIGHT BRINING ANOTHER SHOT OF LIGHT SNOW TO THE FORECAST AREA THIS AFTERNOON AND EVENING. MOST SNOW ACCUMLUATIONS WILL BE ALONG THE SOUTHERN TIER OF THE FORECAST AREA WITH 1 TO 2 INCHES OF ACCUMLUATION OUTSIDE OF THE MOUNTAINS. MOST OF THE FORECAST AREA WILL PICK UP LESS THAN ONE INCH. WINDS WILL REMAIN ON THE BREEZY SIDE AND WILL PRODUCE SOME BLOWING AND DRIFTING THIS AFTERNOON AND EVENING. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 520 AM MST TUE MAR 3 2015 HIGH-IMPACT WINTER STORM CONTINUES THIS MORNING FOR A LARGE PART OF THE CWA. AS EXPECTED...MODERATE TO HEAVY SNOW HAS BECOME QUITE WIDESPREAD THIS MORNING WITH AN ARCTIC COLD FRONT BLASTING SOUTH INTO NORTHERN CO. STRONG NORTHERLY WINDS ARE OCCURRING POST FROPA WITH EXCELLENT MIXING VIA INTENSE COLD ADVECTION ALOFT. PEAK WIND AT KCYS WAS 42 KTS JUST BEFORE 10Z...AND REMAINS STEADY AT 20 TO 30 MPH AT THIS HOUR WITH VERY LOW VISIBILITY OCCURRING IN FALLING AND BLOWING SNOW. DO NOT EXPECT MUCH FOR AMOUNTS AS LLVL FORCING WILL DISAPPEAR QUICKLY...BUT WILL NEED TO MONITOR FOR A POSSIBLE SHORT FUSED ADVISORY IF HEAVY BANDING PERSISTS INTO THE MORNING COMMUTE. A WARM DAY YESTERDAY AHEAD OF THE ARCTIC FRONT SET US UP FOR A FLASH FREEZE...SO ROADWAYS ARE ALREADY QUITE SLICK IN TOWN HERE THIS MORNING. SUSPECT THIS IS THE CASE AREAWIDE BASED ON THE ROAD CLOSURES WE HAVE SEEN ALREADY WITH LARGE SECTIONS OF I25 AND I80 AFFECTED WEST OF LARAMIE AND NORTH OF CHEYENNE. LATEST WATER VAPOR LOOP SHOWS LARGE SCALE TROUGHING ENCOMPASSING MUCH OF THE WESTERN CONUS WITH THE LEAD SHORTWAVE NOW EXITING INTO THE CENTRAL PLAINS. WITH THAT...WE SHOULD CONTINUE TO LOSE DYNAMIC SUPPORT ASSOCIATED WITH THE 150+ KT H25 JET OVER CENTRAL NEBRASKA AND WILL HAVE TO RELY ENTIRELY ON LLVL CONVERGENCE AND FRONTOGENESIS FOR ENHANCED SNOWFALL RATES. SFC COLD FRONT ALREADY ANALYZED ALONG THE CO/WY BORDER WILL CONTINUE TO MOVE SOUTH ALONG THE FRONT RANGE...SO EXPECT SNOW TO LIGHTEN UP BEFORE LONG. EVEN SO...WE SAW SOME HEFTY SNOW RATES OVER PLATTE/NIOBRARA COUNTIES OVERNIGHT WITH THE INITIAL FRONTAL SURGE. INITIAL CALLS TO AREA DISPATCHERS INDICATE GENERALLY 3 TO 5 INCHES WITH WINDS CREATING PROBLEMS. NUMEROUS POWER OUTAGES WERE REPORTED IN NIOBRARA COUNTY AND INTERSTATE 25 WAS CLOSED IN PLATTE. ADDITIONAL LIGHT ACCUMS ARE POSSIBLE THROUGH THE MORNING. NAM/GFS SUGGEST WINDS BECOMING NORTHEASTERLY ALONG THE CENTRAL LARAMIE RANGE BY MID AFTN AS SFC PRESSURE RISES SPREAD INTO SOUTH CENTRAL NE. DEFINITELY CONCERNED WITH POTENTIAL UPSLOPE ENHANCEMENT CAUSING SNOW TO REDEVELOP IN THE AFTN/EVE WITH THE ARRIVAL OF A SECONDARY SHORTWAVE. HRRR IS HITTING THIS AREA HARD BEYOND 21Z. EVEN THOUGH WINDS WILL MOST LIKELY BE A NON FACTOR LATER ON...OPTED TO UPGRADE TO A WINTER STORM WARNING GIVEN OBSERVED IMPACTS AND POTENTIAL FOR AT LEAST ANOTHER COUPLE INCHES OF SNOW THROUGH TONIGHT. ALL AREAS SHOULD SEE THE WORST CONDITIONS RIGHT AWAY IN THE AM WITH THE STRONGEST WINDS OCCURRING THEN. THE MODELS SHOW FLOW ALOFT WEAKENING CONSIDERABLY AFTER 15Z...SO BLOWING SNOW SHOULD BECOME LESS OF A PROBLEM WITH TIME. PRECIPITATION COVERAGE WILL TRANSITION TO SNOW SHOWERS FOR A TIME...BUT ANOTHER SHOT OF PCPN IS EXPECTED LATE THIS AFTN AND EVE WITH A SECONDARY SHORTWAVE AND ASSOCIATED MID LEVEL MOISTURE PLUME UPSTREAM OVER EASTERN IDAHO AS OF 12Z PER MORNING SATELLITE IMAGERY. MIDLVL DRY SLOT HAS PROVEN TO BE A MAJOR INHIBITOR FOR SNOW SO FAR ALONG THE I80 CORRIDOR BETWEEN CHEYENNE AND SIDNEY...SO EXPECT THE BEST CHANCES FOR SNOW LOCALLY TO COME TONIGHT. AMOUNTS WILL PROBABLY BE ON THE LOW SIDE SO DECIDED AGAINST AN ADVISORY FOR NOW...BUT THE DAY SHIFT WILL NEED TO REVISIT. KEPT ALL OTHER HEADLINES THE SAME...EXCEPT FOR EXTENDING THEM THROUGH 07Z WED AS THE NEXT DISTURBANCE WILL KEEP SNOW POTENTIAL GOING A LITTLE LONGER THAN EARLIER EXPECTED. AS SNOW ENDS LATE TONIGHT...WINTER HAZARDS WILL TRANSITION TO WIND CHILLS WITH WIDESPREAD -20F TO -30F READINGS LIKELY. FULLY EXPECT SOME SORT OF WIND CHILL HEADLINES WILL BE NECESSARY ON THE HEELS OF THE CURRENT WINTER PRECIPITATION PRODUCTS. WARMEST TEMPERATURES FOR TODAY OCCURRED OVERNIGHT WITH VERY STRONG H7 COLD AIR ADVECTION EXPECTED TO DRIVE TEMPERATURES DOWNWARD INTO THE AFTERNOON. TEMPERATURES WILL FALL BELOW ZERO ACROSS MUCH OF THE AREA TONIGHT DESPITE WIDESPREAD ABUNDANT MOISTURE ALOFT LEADING TO THICK CLOUDS AND SNOW GIVEN UNSEASONABLY COLD THERMAL PROFILES IN THE LLVLS. HIGHS WEDNESDAY SHOULD BE WELL BELOW ANY CONSENSUS GUIDANCE WITH FRESH SNOWPACK AND 700 MILLIBAR TEMPS REMAINING VERY COLD / -20C PER THE NAM. SHOULD FINALLY SEE SOME IMPROVEMENT ON THURSDAY AS WESTERLY DOWNSLOPE WINDS RETURN FOR AREAS EAST OF THE LARAMIE RANGE...ALLOWING HIGHS TO CLIMB BACK ABOVE FREEZING. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 520 AM MST TUE MAR 3 2015 PROGRESSIVE NORTHWEST FLOW THRU THE WEEKEND WILL GIVE WAY TO A BUILDING RIDGE OF HIGH PRESSURE AND A RETURN TO ABOVE AVERAGE TEMPERATURES FOR EARLY NEXT WEEK. BOTH THE 00Z GFS AND ECMWF ADVERTISE TWO CLIPPER SHORTWAVES EMBEDDED WITHIN THE FLOW WILL TRAVERSE SOMEWHERE THRU THE NRN ROCKIES FRIDAY AND SATURDAY. AS IS TYPICAL IN PROGRESSIVE NORTHWEST FLOW...TIMING AND STRENGTH DIFFERENCES EXIST IN JUST HOW THESE DISTURBANCES PUSH THRU. EITHER SCENARIO CARRIES LITTLE IF ANY IMPACTS FROM THESE SYSTEM. ALTHOUGH...THE DID HAD SOME MOUNTAIN SNOW SHOWER CHANCES ON SUNDAY WITH THE GFS STEERING ONE OF THE CLIPPERS DIRECTLY OVR THE REGION. THE NORTHWEST FLOW WILL CONTINUE SUNDAY AND MONDAY...WITH THE RIDGE AXIS ARRIVING ON TUESDAY. TEMPERATURES WILL HOLD CLOSE TO SEASONAL LEVELS FRIDAY THROUGH SUNDAY WITH HIGHS GENERALLY REACHING THE 30S WEST AND 40S OVR THE ERN PLAINS. THE APPROACHING UPPER-RIDGE AND ASSOCIATED WAA WILL LIFT HIGH TEMPERATURES ABOVE AVERAGE FOR THE FIRST TIME SINCE THE THIRD WEEK OF FEBRUARY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1108 AM MST TUE MAR 3 2015 FAIRLY WIDESPREAD MVFR CONDITIONS WILL PERSIST OVER THE TERMINALS THROUGH THIS EVENING WITH SCTD IFR CIGS AND VSBYS IN SNOW. CONDITIONS SHOULD IMPROVE LATER THIS EVENING AND OVERNIGHT. && .FIRE WEATHER... ISSUED AT 520 AM MST TUE MAR 3 2015 A WINTER STORM WILL CONTINUE TO IMPACT MUCH OF SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE THROUGH TONIGHT. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE LIKELY ALONG WITH STRONG NORTHERLY WINDS RESULTING IN EXTREMELY DANGEROUS TRAVEL CONDITIONS. VERY COLD TEMPERATURES ARE EXPECTED TODAY AND TONIGHT WITH WIDESPREAD DANGEROUS WIND CHILLS POSSIBLE ON EARLY WEDNESDAY MORNING. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR WYZ101>111-113-115>117. WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR WYZ112-114. NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR NEZ002- 003-095-096. && $$ UPDATE...SML SHORT TERM...HAMMER LONG TERM...HAHN AVIATION...RE FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1058 AM MST TUE MAR 3 2015 .UPDATE... ISSUED AT 1052 AM MST TUE MAR 3 2015 UPDATED WINTER WEATHER HEADLINES TO CONVERT THE WINTER STORM WARNING TO AN ADVISORY. SOME POCKETS OF BLOWING SNOW CONTINUE ALONG WITH SOME LIGHT SNOW SHOWER ACTIVITY THIS MORNING. THE NORTHERN STREAM DISTURBANCE WHICH IS CURRENTLY OVER WESTERN WYOMING WILL MOVE EASTWARD TODAY AND TONIGHT BRINING ANOTHER SHOT OF LIGHT SNOW TO THE FORECAST AREA THIS AFTERNOON AND EVENING. MOST SNOW ACCUMLUATIONS WILL BE ALONG THE SOUTHERN TIER OF THE FORECAST AREA WITH 1 TO 2 INCHES OF ACCUMLUATION OUTSIDE OF THE MOUNTAINS. MOST OF THE FORECAST AREA WILL PICK UP LESS THAN ONE INCH. WINDS WILL REMAIN ON THE BREEZY SIDE AND WILL PRODUCE SOME BLOWING AND DRIFTING THIS AFTERNOON AND EVENING. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 520 AM MST TUE MAR 3 2015 HIGH-IMPACT WINTER STORM CONTINUES THIS MORNING FOR A LARGE PART OF THE CWA. AS EXPECTED...MODERATE TO HEAVY SNOW HAS BECOME QUITE WIDESPREAD THIS MORNING WITH AN ARCTIC COLD FRONT BLASTING SOUTH INTO NORTHERN CO. STRONG NORTHERLY WINDS ARE OCCURRING POST FROPA WITH EXCELLENT MIXING VIA INTENSE COLD ADVECTION ALOFT. PEAK WIND AT KCYS WAS 42 KTS JUST BEFORE 10Z...AND REMAINS STEADY AT 20 TO 30 MPH AT THIS HOUR WITH VERY LOW VISIBILITY OCCURRING IN FALLING AND BLOWING SNOW. DO NOT EXPECT MUCH FOR AMOUNTS AS LLVL FORCING WILL DISAPPEAR QUICKLY...BUT WILL NEED TO MONITOR FOR A POSSIBLE SHORT FUSED ADVISORY IF HEAVY BANDING PERSISTS INTO THE MORNING COMMUTE. A WARM DAY YESTERDAY AHEAD OF THE ARCTIC FRONT SET US UP FOR A FLASH FREEZE...SO ROADWAYS ARE ALREADY QUITE SLICK IN TOWN HERE THIS MORNING. SUSPECT THIS IS THE CASE AREAWIDE BASED ON THE ROAD CLOSURES WE HAVE SEEN ALREADY WITH LARGE SECTIONS OF I25 AND I80 AFFECTED WEST OF LARAMIE AND NORTH OF CHEYENNE. LATEST WATER VAPOR LOOP SHOWS LARGE SCALE TROUGHING ENCOMPASSING MUCH OF THE WESTERN CONUS WITH THE LEAD SHORTWAVE NOW EXITING INTO THE CENTRAL PLAINS. WITH THAT...WE SHOULD CONTINUE TO LOSE DYNAMIC SUPPORT ASSOCIATED WITH THE 150+ KT H25 JET OVER CENTRAL NEBRASKA AND WILL HAVE TO RELY ENTIRELY ON LLVL CONVERGENCE AND FRONTOGENESIS FOR ENHANCED SNOWFALL RATES. SFC COLD FRONT ALREADY ANALYZED ALONG THE CO/WY BORDER WILL CONTINUE TO MOVE SOUTH ALONG THE FRONT RANGE...SO EXPECT SNOW TO LIGHTEN UP BEFORE LONG. EVEN SO...WE SAW SOME HEFTY SNOW RATES OVER PLATTE/NIOBRARA COUNTIES OVERNIGHT WITH THE INITIAL FRONTAL SURGE. INITIAL CALLS TO AREA DISPATCHERS INDICATE GENERALLY 3 TO 5 INCHES WITH WINDS CREATING PROBLEMS. NUMEROUS POWER OUTAGES WERE REPORTED IN NIOBRARA COUNTY AND INTERSTATE 25 WAS CLOSED IN PLATTE. ADDITIONAL LIGHT ACCUMS ARE POSSIBLE THROUGH THE MORNING. NAM/GFS SUGGEST WINDS BECOMING NORTHEASTERLY ALONG THE CENTRAL LARAMIE RANGE BY MID AFTN AS SFC PRESSURE RISES SPREAD INTO SOUTH CENTRAL NE. DEFINITELY CONCERNED WITH POTENTIAL UPSLOPE ENHANCEMENT CAUSING SNOW TO REDEVELOP IN THE AFTN/EVE WITH THE ARRIVAL OF A SECONDARY SHORTWAVE. HRRR IS HITTING THIS AREA HARD BEYOND 21Z. EVEN THOUGH WINDS WILL MOST LIKELY BE A NON FACTOR LATER ON...OPTED TO UPGRADE TO A WINTER STORM WARNING GIVEN OBSERVED IMPACTS AND POTENTIAL FOR AT LEAST ANOTHER COUPLE INCHES OF SNOW THROUGH TONIGHT. ALL AREAS SHOULD SEE THE WORST CONDITIONS RIGHT AWAY IN THE AM WITH THE STRONGEST WINDS OCCURRING THEN. THE MODELS SHOW FLOW ALOFT WEAKENING CONSIDERABLY AFTER 15Z...SO BLOWING SNOW SHOULD BECOME LESS OF A PROBLEM WITH TIME. PRECIPITATION COVERAGE WILL TRANSITION TO SNOW SHOWERS FOR A TIME...BUT ANOTHER SHOT OF PCPN IS EXPECTED LATE THIS AFTN AND EVE WITH A SECONDARY SHORTWAVE AND ASSOCIATED MID LEVEL MOISTURE PLUME UPSTREAM OVER EASTERN IDAHO AS OF 12Z PER MORNING SATELLITE IMAGERY. MIDLVL DRY SLOT HAS PROVEN TO BE A MAJOR INHIBITOR FOR SNOW SO FAR ALONG THE I80 CORRIDOR BETWEEN CHEYENNE AND SIDNEY...SO EXPECT THE BEST CHANCES FOR SNOW LOCALLY TO COME TONIGHT. AMOUNTS WILL PROBABLY BE ON THE LOW SIDE SO DECIDED AGAINST AN ADVISORY FOR NOW...BUT THE DAY SHIFT WILL NEED TO REVISIT. KEPT ALL OTHER HEADLINES THE SAME...EXCEPT FOR EXTENDING THEM THROUGH 07Z WED AS THE NEXT DISTURBANCE WILL KEEP SNOW POTENTIAL GOING A LITTLE LONGER THAN EARLIER EXPECTED. AS SNOW ENDS LATE TONIGHT...WINTER HAZARDS WILL TRANSITION TO WIND CHILLS WITH WIDESPREAD -20F TO -30F READINGS LIKELY. FULLY EXPECT SOME SORT OF WIND CHILL HEADLINES WILL BE NECESSARY ON THE HEELS OF THE CURRENT WINTER PRECIPITATION PRODUCTS. WARMEST TEMPERATURES FOR TODAY OCCURRED OVERNIGHT WITH VERY STRONG H7 COLD AIR ADVECTION EXPECTED TO DRIVE TEMPERATURES DOWNWARD INTO THE AFTERNOON. TEMPERATURES WILL FALL BELOW ZERO ACROSS MUCH OF THE AREA TONIGHT DESPITE WIDESPREAD ABUNDANT MOISTURE ALOFT LEADING TO THICK CLOUDS AND SNOW GIVEN UNSEASONABLY COLD THERMAL PROFILES IN THE LLVLS. HIGHS WEDNESDAY SHOULD BE WELL BELOW ANY CONSENSUS GUIDANCE WITH FRESH SNOWPACK AND 700 MILLIBAR TEMPS REMAINING VERY COLD / -20C PER THE NAM. SHOULD FINALLY SEE SOME IMPROVEMENT ON THURSDAY AS WESTERLY DOWNSLOPE WINDS RETURN FOR AREAS EAST OF THE LARAMIE RANGE...ALLOWING HIGHS TO CLIMB BACK ABOVE FREEZING. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 520 AM MST TUE MAR 3 2015 PROGRESSIVE NORTHWEST FLOW THRU THE WEEKEND WILL GIVE WAY TO A BUILDING RIDGE OF HIGH PRESSURE AND A RETURN TO ABOVE AVERAGE TEMPERATURES FOR EARLY NEXT WEEK. BOTH THE 00Z GFS AND ECMWF ADVERTISE TWO CLIPPER SHORTWAVES EMBEDDED WITHIN THE FLOW WILL TRAVERSE SOMEWHERE THRU THE NRN ROCKIES FRIDAY AND SATURDAY. AS IS TYPICAL IN PROGRESSIVE NORTHWEST FLOW...TIMING AND STRENGTH DIFFERENCES EXIST IN JUST HOW THESE DISTURBANCES PUSH THRU. EITHER SCENARIO CARRIES LITTLE IF ANY IMPACTS FROM THESE SYSTEM. ALTHOUGH...THE DID HAD SOME MOUNTAIN SNOW SHOWER CHANCES ON SUNDAY WITH THE GFS STEERING ONE OF THE CLIPPERS DIRECTLY OVR THE REGION. THE NORTHWEST FLOW WILL CONTINUE SUNDAY AND MONDAY...WITH THE RIDGE AXIS ARRIVING ON TUESDAY. TEMPERATURES WILL HOLD CLOSE TO SEASONAL LEVELS FRIDAY THROUGH SUNDAY WITH HIGHS GENERALLY REACHING THE 30S WEST AND 40S OVR THE ERN PLAINS. THE APPROACHING UPPER-RIDGE AND ASSOCIATED WAA WILL LIFT HIGH TEMPERATURES ABOVE AVERAGE FOR THE FIRST TIME SINCE THE THIRD WEEK OF FEBRUARY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 520 AM MST TUE MAR 3 2015 AVIATION CONDITIONS WILL CONTINUE TO BE POOR TODAY WITH WIDESPREAD IFR CONDITIONS PREVAILING AS A SERIES OF STORMS SYSTEMS AND FRONT PUSH THROUGH AREA AIRFIELDS. ALL SITES WILL SEE A PERIOD OF -SN/SN ESPECIALLY THROUGH 16Z AND AGAIN BETWEEN 22-06Z. NORTH/NORTHEAST WINDS WILL PREVAIL TODAY AND TONIGHT AT SPEEDS OF BETWEEN 15 AND 25 KNOTS. THESE BREEZY CONDITIONS WILL PRODUCE SOME AREAS OF BLOWING SNOW. LOW CIGS ALONG WITH THE ACTIVE UPSLOPE PATTERN WILL OBSCURE MOUNTAINS TODAY AND TONIGHT. SHOULD BEGIN TO SEE IMPROVEMENT TO CONDITIONS AFTER 04Z OR SO...WITH VFR RETURNING TO MANY SPOTS AFTER 06Z. && .FIRE WEATHER... ISSUED AT 520 AM MST TUE MAR 3 2015 A WINTER STORM WILL CONTINUE TO IMPACT MUCH OF SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE THROUGH TONIGHT. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE LIKELY ALONG WITH STRONG NORTHERLY WINDS RESULTING IN EXTREMELY DANGEROUS TRAVEL CONDITIONS. VERY COLD TEMPERATURES ARE EXPECTED TODAY AND TONIGHT WITH WIDESPREAD DANGEROUS WIND CHILLS POSSIBLE ON EARLY WEDNESDAY MORNING. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR WYZ101>111-113-115>117. WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR WYZ112-114. NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR NEZ002- 003-095-096. && $$ UPDATE...SML SHORT TERM...HAMMER LONG TERM...HAHN AVIATION...HAHN FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
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
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
403 AM EST THU MAR 5 2015 ...NEAR RECORD WARMTH TODAY FOLLOWED BY SIGNIFICANTLY COLDER CONDITIONS FRIDAY... .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST TODAY AND PUSH OFFSHORE THIS EVENING. COLDER HIGH PRESSURE WILL BUILD OVER THE AREA THURSDAY NIGHT AND WILL PREVAIL INTO SUNDAY. NEXT WEEK...AN UNSETTLED PATTERN WILL DEVELOP BETWEEN A STATIONARY FRONT SOUTH AND EAST OF THE REGION AND HIGH PRESSURE CENTERED TO THE NORTH. && .NEAR TERM /THROUGH TODAY/... THE NEXT 24 HOURS ARE GOING TO BE QUITE DRAMATIC...WHICH IS LIKELY UNDERSTATING WHAT THE LOWCOUNTRY AND COASTAL EMPIRE WILL EXPERIENCE AS A POWERFUL COLD FRONT PUSHES THROUGH THE AREA THIS EVENING. THROUGH SUNRISE...UNUSUALLY WARM CONDITIONS DOMINATE THE REGION THIS MORNING WITH A WELL MIXED BOUNDARY LAYER IN PLACE. COASTAL WEBCAMS AND SATELLITE DATA INDICATE WIDESPREAD SEA FOG CONTINUES TO PLAGUE THE COASTAL WATERS...SOME OF WHICH IS OCCASIONALLY BRUSHING COASTAL COMMUNITIES...MAINLY ACROSS CHARLESTON COUNTY WHERE LOW-LEVEL TRAJECTORIES ARE THE MOST FAVORABLE FOR SEA FOG TO PUSH TO THE COAST. THERE ARE SOME INDICATIONS IN BOTH THE H3R AND RAP FOG FIELDS THAT THE SEA FOG COULD REACH AS FAR INLAND AS HIGHWAY 17 IN CHARLESTON COUNTY...BUT CONFIDENCE IN THIS IS QUITE LOW GIVEN THE PROJECTED CONTINUATION OF SOUTHWEST WINDS THROUGH SUNRISE. TRENDS WILL BE WATCHED CAREFULLY OVER THE NEXT SEVERAL HOURS...HOWEVER. A SPECIAL WEATHER STATEMENT WILL BE REISSUED TO ADDRESS THE SEA FOG LOWERING VSBYS TO 1/2 MILE OR LESS AT TIMES. FOR TODAY...MORNING LOW CLOUDS MOVING UP FROM THE GULF OF MEXICO WILL MIX OUT BY MID-MORNING AS VERTICAL MIXING INTENSIFIES AHEAD OF AN APPROACHING COLD FRONT. THE COMBINATION OF PRE-FRONTAL COMPRESSION...PERIODS OF INSOLATION AND A 1-2C INCREASE IN 850 HPA TEMPERATURES OVER THE PAST 24 HOURS SHOULD RESULT IN HIGH TEMPERATURES VERY NEAR WHAT WAS EXPERIENCED WEDNESDAY...IF NOT A BIT WARMER IF CLOUDS MIX OUT QUICK ENOUGH. HIGHS IN THE LOWER-MID 80S LOOK REASONABLE FOR MOST AREAS AWAY FROM THE IMMEDIATE COAST WHERE INFLUENCES FROM THE COOLER SHELF WATERS WILL NOT BE FACTOR. STRENGTHENING SOUTHWESTERLY WINDS SHOULD SUPPRESS OR AT LEAST SEVERELY DELAY THE INLAND PENETRATION OF THE RESULT SEA BREEZE CIRCULATION...ESPECIALLY ALONG THE GEORGIA COAST THIS AFTERNOON...HOWEVER COASTAL LOCATIONS WILL REMAIN SIGNIFICANTLY COOLER THAN INLAND AREAS GIVEN THE PROXIMITY TO THE CHILLY SHELF WATERS. MOST OF THE DAY WILL BE DRY AS A COLD FRONT APPROACHES FROM THE WEST. MODELS AND CURRENT RADAR DATA SUGGEST THE FRONTAL STRUCTURE IS ANAFRONTAL IN NATURE...SO VERY LITTLE IN THE WAY OF PRE- FRONTAL SHOWER ACTIVITY WILL OCCUR WITH THE BULK OF THE RAINFALL OCCURRING ALONG AND BEHIND THE FRONT ITSELF. RAIN WILL BEGIN TO MOVE INTO THE WESTERN ZONES BY MID-AFTERNOON AND SPREAD EAST TO THE COAST AS THE COLD FRONT MOVES THROUGH THE FORECAST AREA. POPS WILL GENERALLY BE CAPPED AT 50-70 PERCENT WITH THE HIGHER PROBABILITIES OCCURRING ACROSS INTERIOR SOUTHEAST SOUTH CAROLINA. TEMPERATURES WILL FALL AS THE FRONT MOVES IN AND RAIN BEGINS TO FALL SO HAVE TRIED TO TIME THESE THERMAL FALLS TO REFLECT THE EXPECTED TIMING OF THE BOTH THE FRONT AND ONSET OF RAIN. INSTABILITY WILL BE SUFFICIENT FOR A FEW TSTMS ALONG THE FRONT ITSELF...SO A CHANCE FOR TSTMS WILL BE MAINTAINED FOR ALL AREAS. THERE IS NO RISK FOR SEVERE TSTMS WITH THIS SYSTEM. GUSTY SOUTHWEST WINDS WILL OCCUR WITHIN THE WARM SECTOR. GUSTS COULD APPROACH 25-30 MPH AT TIMES...SIMILAR TO WEDNESDAY...BUT MIXING PROFILES OVER LAKE MOULTRIE WILL BE POOR AS WARM AIR FLOWS OVER THE CHILLY LAKE WATERS. THIS WILL YIELD ABSOLUTELY STABLE CONDITIONS OVER THE OPEN LAKE WATERS WITH LITTLE IN THE WAY OF SIGNIFICANT WIND EXPECTED WITHIN THE THICK MARINE LAYER. THE DEGREE OF GUSTINESS WILL EVEN BE SUBDUED ALONG THE LAKESHORE AS A ROBUST LAKE BREEZE CIRCULATION IS LIKELY...WHICH WILL TEND TO STABILIZE THE BOUNDARY LAYER. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... TONIGHT...RAIN CHANCES WILL STEADILY END FROM WEST-EAST THIS EVENING AS THE COLD FRONT PUSHES THROUGH. THE BULK OF THE MEASURABLE RAINS WILL BE OFFSHORE 9 PM TO MIDNIGHT WITH ONLY ISOLATED TO PERHAPS SCATTERED SHOWERS LINGERING THROUGH EARLY FRIDAY. IN THE WAKE OF THE PRIMARY RAIN BAND...LOW CEILINGS AND PERIODS OF DRIZZLE WILL FILL IN AS COLDER AIR PUSHES SOUTH. TEMPERATURES COULD BE NEAR FREEZING ACROSS UPPER PORTIONS OF DORCHESTER AND BERKELEY COUNTIES AFTER 4-5 AM. ALTHOUGH SOUNDINGS SHOW MID-LEVEL MOISTURE QUICKLY SCOURING OUT BY THIS TIME...DEEP MOISTURE WITHIN THE BOUNDARY LAYER WILL SUPPORT PERIODS OF DRIZZLE. THIS OPENS THE POSSIBILITY FOR A LITTLE FREEZING DRIZZLE BY SUNRISE FRIDAY...ROUGHLY ALONG AND NORTH OF SAINT GEORGE- RIDGEVILLE-HUGER-SHULERVILLE LINE. WITH ONLY MARGINALLY COLD CONDITIONS AND TEMPERATURES HOLDING RIGHT AT FREEZING... SIGNIFICANT IMPACTS APPEAR UNLIKELY ATTM. HOWEVER...A VERY LIGHT GLACE ON ELEVATED SURFACES SUCH AS TREES...METAL OBJECTS AS WELL AS SOME BRIDGES AND OVERPASSES CAN NOT BE COMPLETELY RULED OUT. GROUND CONDITIONS WILL BE TOO WARM TO SUPPORT ICE ACCUMULATIONS OTHERWISE...WHICH INCLUDES NON-ELEVATED ROADWAYS. GIVEN THE MARGINAL NATURE OF THIS EVENT...THE FORECAST WILL CALL FOR PERIODS OF DRIZZLE WITH A CHANCE OF FREEZING DRIZZLE IN THE AFOREMENTIONED AREAS. THE RISK FOR FREEZING DRIZZLE WILL SURGE SOUTH AFTER SUNRISE AS SUBFREEZING WET-BULB TEMPERATURES ADVECT SOUTH. LOWS WILL RANGE FROM AROUND FREEZING FAR NORTH TO THE LOWER-MID 40S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. ONE COULD ARGUE THAT A FREEZE WARNING IS NEEDED FOR PARTS OF DORCHESTER AND BERKELEY COUNTIES NOW THAT ITS BEYOND 1 MARCH AND THE GROWING SEASON HAS BEGUN. HOWEVER...GIVEN THE TRANSIENT NATURE OF THE FREEZING LINE AND CONSIDERING A MUCH MORE SIGNIFICANT AND WIDESPREAD FREEZE WILL OCCUR FRIDAY NIGHT...A FREEZE WARNING WILL NOT BE ISSUED. FRIDAY...MODELS HAVE TRENDED DRIER IN THE LOW LEVELS AS COMPARED WITH RECENT RUNS. THUS...EVEN AS THE COLDEST AIR FEATURING TEMPS AROUND FREEZING AND WET BULB TEMPS JUST BELOW FREEZING SPREADS ACROSS INLAND AREAS BETWEEN THE EDISTO RIVER/INTERSTATE 26 AND THE SANTEE RIVER...LOW LEVEL MOISTURE NOW APPEARS BARELY SUFFICIENT TO SUPPORT ANYTHING MORE THAN DRIZZLE. THUS...THE PROBABILITY FOR ANY FREEZING PRECIPITATION HAS DIMINISHED...ALTHOUGH A SLIGHT CHANCE/CHANCE OF FREEZING DRIZZLE IS STILL JUSTIFIED ACROSS NORTHERN/INLAND LOCATIONS THROUGH MIDDAY FRIDAY...POSSIBLY A FAR SOUTH AS A WALTERBORO-NORTH CHARLESTON-MCCLELLANVILLE LINE. EVEN IF A BIT OF FREEZING DRIZZLE OCCURS ANY TRACE AMOUNTS OF GLAZE SHOULD ONLY OCCUR ON ELEVATED SURFACES SUCH AS TREES AND STREET SIGNS...GREATLY LIMITING ANY IMPACTS. FARTHER SOUTH/EAST WHERE DEEPER MOISTURE WILL RESIDE AND SLIGHT CHANCE/CHANCE POPS ARE JUSTIFIED THROUGH MIDDAY/EARLY AFTERNOON... TEMPERATURES WILL REMAIN ABOVE FREEZING. IN GENERAL...GUIDANCE HAS TRENDED TOWARD A SLOW BUT STEADY DRYING TREND...SO POPS DECREASE WITH TIME FRIDAY AFTERNOON AND FALL TO NEAR ZERO FRIDAY NIGHT. ASIDE FROM ANY PRECIP TYPE CONCERNS...FRIDAY WILL PROVIDE TEMPERATURES SOME 35-40F COLDER THAN THOSE OF THURSDAY...ONLY RECOVERING INTO THE UPPER 30S TO MID 40S. FRIDAY NIGHT...CONFIDENCE IS HIGH THAT SUB-FREEZING TEMPERATURES WILL OCCUR ACROSS MOST SOUTH CAROLINA LOCATIONS AND ACROSS SE GEORGIA LOCATIONS WEST OF I-95...AND A HARD FREEZE IS POSSIBLE WELL INLAND. PER COLLABORATION WITH WFO JAX...WILL DEFER DECISIONS REGARDING FREEZE WATCHES/WARNINGS TO SUBSEQUENT FORECAST PACKAGES. DESPITE SUNSHINE...TEMPERATURES WILL REMAIN BELOW NORMAL SATURDAY...RANGING FROM THE MID/UPPER 50S NORTH OF I-16 TO THE LOWER 60S SOUTH. SATURDAY NIGHT...TRANQUIL CONDITIONS WILL PREVAIL...AND LOW TEMPS WILL RANGE FROM THE LOWER/MID 30S WELL INLAND TO THE MID 40S ALONG THE GA COAST. SUNDAY...MID/HIGH LEVEL CLOUDS WILL INCREASE/THICKEN AHEAD OF A WAVE OF LOW PRESSURE APPROACHING FROM THE WEST. HOWEVER...NO RAIN IS EXPECTED DURING THE DAYLIGHT HOURS. ON THE POSITIVE SIDE... TEMPERATURES SHOULD RECOVER INTO THE 60S SUNDAY...CLOSER TO NORMAL FOR EARLY MARCH. LAKE WINDS...FAVORABLE MIXING PROFILES WILL DEVELOP THIS EVENING AND PERSIST THROUGH THE NIGHT AS COLD AIR INTENSIFIES. EXPECT NORTH WINDS OF 20 KT WITH FREQUENT GUSTS TO 25 KT TO PREVAIL THROUGH THE NIGHT...SO A LAKE WIND ADVISORY WILL BE ISSUED. GUSTY CONDITIONS WILL PERSIST THROUGH FRIDAY MORNING BEFORE DIMINISHING. WAVES ON THE OPEN LAKE WATERS WILL BUILD TO 1-2 FEET. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... BETWEEN A STATIONARY FRONT OFF THE SOUTHEAST COAST AND ACROSS THE FL PENINSULA AND HIGH PRESSURE CENTERED NORTH OF THE REGION...A BAROCLINIC ZONE WILL WAVER OVER THE REGION AND WILL CONTRIBUTE TO UNSETTLED CONDITIONS NEXT WEEK. WHILE A MOSTLY CLOUDY REGIME PUNCTUATED BY PERIODS OF PRECIPITATION AND FINALLY DEVOID OF ANY COLD AIR APPEARS LIKELY...CONFIDENCE REGARDING COMPLEX FORECAST DETAILS REMAINS LOW. FOR INSTANCE...WE MAINTAIN CHANCE POPS MONDAY AND TUESDAY...BUT SOME GUIDANCE SUGGESTS THAT LIKELY/CATEGORICAL POPS WILL EVENTUALLY BE NEEDED FOR THIS PERIOD. ALSO...THE POTENTIAL FOR THUNDERSTORMS COULD INCREASE...BUT THE UNCERTAIN DETAILS REGARDING INDIVIDUAL WAVES OF LOW PRESSURE AND AN ASSOCIATED UNCERTAIN POTENTIAL FOR AN INFLUX OF ANY SIGNIFICANT INSTABILITY DOES NOT JUSTIFY ANY MENTION OF THUNDER. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... WATCHING LOW CLOUDS SPREADING NORTHEAST OUT OF THE GULF OF MEXICO. THESE ARE ON TARGET TO IMPACT KSAV 08-9Z WITH CIGS DROPPING TO LOW-END MVFR AND POSSIBLY HIGH END IFR. GUIDANCE SUGGESTS THESE CLOUDS WILL NOT REACH KCHS ATTM AND WILL TREND THE 06Z TAFS IN THAT DIRECTION. AT KSAV WILL SHOW OVC012 TEMPO OVC008 08-12Z TO COVER. VFR AT KCHS. FOG APPEARS UNLIKELY GIVEN THE WELL MIXED BOUNDARY LAYER THAT IS IN PLACE. LOW-LEVEL WIND SHEAR /LLWS/ WILL BE AN ISSUE AT BOTH TERMINALS THROUGH SUNRISE WITH AS MUCH AS 40 KT OF WIND AT 1500 FT OFF THE DECK. VFR FOR MUCH OF THE DAY BEFORE CIGS/VSBYS CRASH LATE AFTERNOON/EARLY EVENING AS A COLD FRONT PUSHES THROUGH THE TERMINALS. IFR OR LOWER CONDITIONS ARE LIKELY AND WILL TREND THE TAFS IN THAT DIRECTION. EXTENDED AVIATION OUTLOOK...VFR LIKELY FRIDAY PM THROUGH THIS WEEKEND. FLIGHT RESTRICTIONS POSSIBLE IN RAIN EARLY NEXT WEEK. && .MARINE... TODAY...NASTY SEA FOG WILL PERSIST OVER THE NEARSHORE WATERS THROUGH EARLY AFTERNOON AS WARM/MOIST AIR FLOWS OVER THE CHILLY SHELF WATERS. THE MOST WIDESPREAD/DENSE SEA FOG WILL OCCUR OVER THE SOUTH CAROLINA NEARSHORE WATERS WHERE SOUTHWEST WINDS WILL PROVIDE LONGER PARCEL RESIDENCE TIMES OVER THE COLD SHELF WATERS. WILL EXTEND THE MARINE DENSE FOG ADVISORY THROUGH 2 PM...ALTHOUGH IT IS POSSIBLE THE GEORGIA NEARSHORE WATERS CAN BE REMOVED PRIOR TO THAT GIVEN THE LESS THAN IDEAL TRAJECTORY STRUCTURE THAT FAR SOUTH. OTHERWISE...SOUTH TO SOUTHWEST WINDS OF 15 KT OR LESS WILL PERSIST WITH SEAS 2-4 FT NEARSHORE WATERS AND 3-5 FT OVER THE CHARLESTON COUNTY AND GEORGIA OFFSHORE WATERS. TONIGHT...CONDITIONS WILL DETERIORATE RAPIDLY THIS EVENING AS A COLD FRONT PUSHES OFF THE COAST AND STRONG COLD AIR ADVECTION ENSUES. THE COMBINATION OF STRONG POST-FRONTAL COLD AIR ADVECTION AND STRONG ISALLOBARIC PRESSURES RISES WILL SUPPORT GALES FOR MUCH OF THE NIGHT OVER THE GEORGIA OFFSHORE WATERS AND THE CHARLESTON COUNTY WATERS WHERE FREQUENT GUSTS TO 35-40 KT GALES WILL OCCUR. THE HIGHEST WINDS WILL OCCUR OVER THE GEORGIA OFFSHORE WATERS...ROUGHLY BEYOND 40 NM...WHERE CONTRAFLOW ALONG THE WESTERN WALL OF THE GULF STREAM WILL BE AT ITS STRONGEST. THE GALE WATCH WILL BE UPGRADED TO A WARNING FOR THESE WATERS BEGINNING AT 6 PM AND CONTINUING THROUGH THE NIGHT. FOR THE OTHER NEARSHORE ZONES...INCLUDING THE CHARLESTON HARBOR...WINDS WILL REMAIN JUST BELOW GALE FORCE...SO SMALL CRAFT ADVISORIES WILL BE MAINTAINED. SEAS WILL BUILD TO 4-6 FT NEARSHORE WATERS AND 6-8 FT OFFSHORE WATERS. FRIDAY THROUGH MONDAY NIGHT...GALES WILL TRANSITION TO SMALL CRAFT ADVISORIES FRIDAY...AND ELEVATED N/NE WINDS AND ASSOCIATED SEAS WILL PERSIST INTO SATURDAY. A MORE TRANQUIL REGIME IS EXPECTED AS HIGH PRESSURE SHIFTS OVER THE WATERS SATURDAY NIGHT THROUGH SUNDAY. THEN...FORECAST CONFIDENCE DECREASES NEXT WEEK AS WINDS/SEAS WILL DEPEND ON A HIGHLY UNCERTAIN STORM TRACK. THE LATEST FORECAST HOLDS WINDS/SEAS WELL BELOW SCA LEVELS...BUT AN OFFSHORE TRACK FOLLOWED BY DEEPER AREAS OF LOW PRESSURE WILL TRANSLATE TO STRONGER WINDS AND HIGHER SEAS. && .CLIMATE... RECORD HIGHS FOR 5 MARCH... KCHS... 85/1997 KCXM... 84/1923 KSAV... 86/1955 RECORD LOW MAXIMUMS FOR 6 MARCH... KCHS... 43/1960 KCXM... 43/1960 KSAV... 42/1901 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...LAKE WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 2 PM EST FRIDAY FOR SCZ045. MARINE...DENSE FOG ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR AMZ350- 352-354. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 4 PM EST FRIDAY FOR AMZ352-354. GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EST FRIDAY FOR AMZ350. GALE WARNING FROM 6 PM THIS EVENING TO 2 PM EST FRIDAY FOR AMZ374. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 11 AM EST FRIDAY FOR AMZ330. && $$ ST/SPR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
354 AM CST THU MAR 5 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST THU MAR 5 2015 QUIET CONDITIONS REIGN ACROSS THE REGION EARLY THIS MORNING WITH MOSTLY CLEAR SKIES.THE CWA SITS IN BETWEEN UPPER LEVEL DISTURBANCES IN NORTHWESTERLY FLOW...ONE BEING THE TROUGH AXIS EXTENDING FROM ROUGHLY THE HUDSON BAY SOUTHWARD INTO THE SRN PLAINS...AND THE OTHER A WEAKER SHORTWAVE DISTURBANCE NOW WORKING ITS WAY INTO NERN MONTANA. AT THE SURFACE...HIGH PRESSURE REMAINS THE DOMINANT FEATURE...AND IS CURRENTLY CENTERED OVER ERN PORTION OF NEB/SD. WINDS ACROSS MUCH OF THE CWA REMAIN ON THE LIGHT/VARIABLE SIDE...AND TEMPS AS OF 3 AM RANGE FROM RIGHT AROUND THE 0 DEGREE MARK IN THE N/NE TO THE LOWER TEENS FURTHER SOUTH. THROUGH THE SHORT TERM PERIOD OF TODAY AND TONIGHT...WILL CONTINUE TO SEE NORTHWESTERLY FLOW SET UP IN THE UPPER LEVEL WITH THAT MAIN TROUGH AXIS PUSHING FURTHER EAST AND RIDGING IN PLACE OVER THE WEST COAST...AND WHILE MODELS SHOW THAT WEAK DISTURBANCE CURRENTLY OVER NERN MONTANA SLIDING THROUGH THE REGION LATER TODAY/THIS EVENING...THERE IS GOOD SUPPORT WITH KEEPING THE FORECAST DRY. AT THE SURFACE...THAT ARE OF HIGH PRESSURE CURRENTLY KEEPING OUR WINDS LIGHT WILL SLIDE OFF TO THE E/SE WITH TIME...WHILE A TROUGH OF LOW PRESSURE SETS UP ACROSS THE HIGH PLAINS. AS A RESULT THE WINDS WILL TURN MORE SRLY WITH TIME...A BIT MORE SWRLY ACROSS OUR FAR WRN COUNTIES. THOUGH THAT WEAK DISTURBANCE MOVING THROUGH LATER ON WONT BE BRINGING ANY PRECIPITATION TO THE CWA...IT WILL BE PUSHING A TROUGH AXIS THROUGH...TURNING WINDS MORE WESTERLY BY SUNRISE TOMORROW. MODELS ARE IN GOOD AGREEMENT SHOWING A MODERATING AIR MASS BUILDING INTO THE REGION FROM THE WEST...AND WITH THOSE MORE SRLY/EVENTUALLY WRLY WINDS...WILL BRING A WELCOME RISE IN TEMPERATURES BOTH TODAY AND TONIGHT. WENT CLOSER TO THE RAP FOR HIGHS TODAY...WHICH WAS A BUMP UP FOR MUCH OF THE AREA BUT NOT A HUGE CHANGE...WITH MID 30S IN THE EAST TO UPPER 40S IN THE WEST FOR FORECAST HIGHS TODAY. OVERNIGHT LOWS TONIGHT WILL BE MORE MILD COMPARED TO CURRENT TEMPS...WITH LOW/MID 20S IN THE FORECAST. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 353 AM CST THU MAR 5 2015 MUCH WARMER AIR WITH DRY CONDITIONS WILL BE THE BIG STORY LINE THIS WEEKEND INTO AT LEAST THE MIDDLE OF NEXT WEEK. WE WILL TRANSITION INTO MORE OF A SPLIT FLOW PATTERN WITH THE COLD ARCTIC AIR BOTTLED UP OVER CANADA...AND FAIRLY PROGRESSIVE FLOW OF PACIFIC ORIGIN ACROSS MUCH OF THE CONUS. MOST DAYS THE SFC WIND WILL HAVE SOMEWHAT OF A DOWNSLOPING WESTERLY COMPONENT AND AN ELEVATED MIXED LAYER OFF THE ROCKIES WILL KEEP TEMPERATURES ALOFT FAIRLY WARM. THIS ALL POINTS TO WARM SFC TEMPERATURES THAT WILL BE ABOVE NORMAL...TO EVEN WELL ABOVE NORMAL FOR THIS TIME OF YEAR...WHICH WILL BE A WELCOMED CHANGE AFTER OUR RECENT COLD SNAP. DESPITE NORMAL HIGHS ONLY BEING IN THE MID 40S...WE EXPECT TO SEE HIGHS THE NEXT FEW DAYS GENERALLY RANGING FROM THE MID 50S TO THE MID 60S. CONFIDENCE IS HIGH IN DRY WEATHER WITH GOOD MODEL AGREEMENT POINTING TOWARDS DRY CONDITIONS. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1123 PM CST WED MAR 4 2015 QUIET WEATHER WITH VFR CONDITIONS REMAIN IN THE FORECAST FOR THIS TAF PERIOD...WITH OVERALL LITTLE IN THE WAY OF CLOUD COVER EXPECTED...BUT ANY CLOUDS THAT DO PASS THROUGH LOOK TO REMAIN IN THE MID/UPPER LEVELS. A WEAK SURFACE PATTERN WILL KEEP WINDS ON THE LIGHT SIDE THIS MORNING...BEFORE A TIGHTENING PRESSURE GRADIENT ALLOWS FOR INCREASED S/SWRLY WINDS THROUGH THE REST OF THE PERIOD. SPEEDS LOOK TO TOP OUT BETWEEN 1O AND 15 MPH. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...WESELY AVIATION...ADP
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
223 AM EST THU MAR 5 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA THIS MORNING. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... WATER VAPOR/SATL DERIVED PWAT IMAGERY SHOWING AN ATMOSPHERIC RIVER OF ANOMALOUS PWATS EXTENDING FROM THE S PACIFIC OCEAN NEWRD INTO THE MISS VALLEY AND EVENTUALLY PA AND THE NEW ENGLAND STATES. THIS DEEP MOISTURE PLUME IS OVERRUNNING AN EXPANSIVE ARCTIC HIGH PRES TO THE NORTH. EARLIER MIXED PRECIP ACROSS FAR SRN PENN AND THE LOWER SUSQ VALLEY HAS CHANGED OVER TO ALL SNOW BETWEEN 06-07Z AS THE MEAN 925-850MB TEMP DIPPED TO JUST BELOW ZERO C. BRIGHT BANDING NEAR AND JUST SOUTH OF KTHV AND KLNS SUGGESTS THAT SLEET/RAIN WILL BE MIXED IN WITH THE SNOWFLAKES FOR THE NEXT HOUR. UPPER FLOW WILL BE BACKING SLIGHTLY EARLY TODAY AHEAD OF THE APPROACHING...POSITIVE TILT UPPER TROUGH EXTENDING FROM THE UPPER GLAKES TO MID MISS RIVER VALLEY. IN ADDITION...SHORT RANGE...HIGHER RESOLUTION MODELS INDICATE A BAND OF WEAK 850-700 FGEN DEVELOPING/MVG NE FROM ECENT OHIO TO NERN PENN. THIS WILL CAUSE THE PRECIP /SNOW/ SHIELD TO TEMPORARILY BULGE NORTH FOR SEVERAL HOURS DURING THE MID-LATE MORNING /09-15Z/...AND LIKELY REACH SLIGHTLY NORTH OF THE I-80 CORRIDOR. THIS SCENARIO AGREES QUITE WELL WITH OUR CURRENT SNOWFALL FORECAST WITH RESPECT TO AMOUNTS AND AREAL DISTRIBUTION. COLDER AIR WILL CONTINUE TO FILTER INTO THE REGION ON NW FLOW. LATEST 21-00Z SREF AND OPER MDL DATA CONTINUE TO POINT TOWARD A GENERAL 2-4 INCH SNOWFALL ACROSS THE SOUTHERN COUNTIES OVERNIGHT...WITH PERHAPS A FEW AMTS NR 6 ALONG THE MD BORDER. TEMPERATURES AT 07Z RUNNING FROM THE L20S ACROSS THE NW MTNS...TO THE L-M30S IN THE SOUTHERN VALLEYS/LOWER SUSQ REGION. HOWEVER...ARRIVAL OF PRECIP AND LOW LVL COLD ADVECTION WILL DROP READINGS TO THE TEENS AND 20S BY DAWN. PERTINENT POINT OF PREVIOUS DISC AND MODEL DATA... 21Z SREF AND 18Z GEFS THREAT PAGES STILL PAINT MY FAR SERN ZONES AS HAVING THE HIGHEST RISK FOR HEAVY SNOW THROUGH MID DAY THURSDAY...WITH A RATHER SHARP CUT OFF ON THE BACK SIDE UP INTO THE CENTRAL MOUNTAINS. HOWEVER...LEANING TOWARD THE MORE RECENT 00Z AND HRRR GUIDANCE...WHICH INDICATES SLIGHTLY LOWER AMTS THAN EARLIER EXPECTED. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/... BLEND OF LATEST MDL DATA INDICATE SNOW WILL TAPER OFF BY LATE AM ACROSS THE CENTRAL COUNTIES...AND MAY LAST UNTIL LATE AFTN ACROSS YORK/LANCASTER COUNTIES. ARCTIC HIGH AND ASSOC DRY AIR MASS WILL ARRIVE EARLY OVR THE NW COUNTIES...RESULTING IN DRY/COLD WX THE ENTIRE DAY UP THERE. SOME PARTIAL CLEARING APPEARS LIKELY ACROSS THE NW COUNTIES LATE IN THE DAY. ELSEWHERE...MDL SOUNDINGS INDICATE A MID LVL CLOUD DECK WILL LINGER EVEN AFTER THE SNOW ENDS. OVERCAST SKIES AND COLD ADVECTION WILL LIKELY BLUNT ANY DIURNAL WARMING AND RESULT IN STEADY TEMPS THRU EARLY AFTN...THEN FALLING TEMPS LATE. CONSALL OUTPUT SUPPORTS DAYTIME TEMPS FROM ONLY ARND 10F ACROSS THE NW MTNS...TO THE L20S ACROSS THE SOUTHEAST COUNTIES...ANOTHER EXCEPTIONALLY COLD DAY FOR THE TIME OF YEAR. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE AND BELOW NORMAL LOW-LEVEL TEMPERATURES WILL DOMINATE THE REGION THURSDAY NIGHT INTO LATE FRIDAY. UNSEASONABLY COLD AIR...PERHAPS THE LAST OF THE SIGNIFICANT ARCTIC SURGES OF OUR ENDLESS WINTER. BASED ON THE LOW TEMPERATURES NEAR AND BELOW 0F AND THE WINDS...THE POTENTIAL EXISTS FOR SOME AREAS TO EXPERIENCE WIND CHILLS OVERNIGHT THURSDAY INTO FRIDAY WHICH MIGHT REQUIRE AN ADVISORY ACROSS THE NORTHERN TIER COUNTIES. SATURDAY THE TEMPERATURES AT 850 MB RETURN CLOSER TO NORMAL AND HIGH PRESSURE DRIFTS TO OUR SOUTH. PENNSYLVANIA SHOULD REMAIN NORTH OF THIS WEAK HIGH....CUTTING OFF ANY MOISTURE TO THE SOUTH...KEEPING THE REGION IN WEAK WESTERLY FLOW INTO MONDAY. THE PERIOD SHOULD BE RELATIVELY DRY WITH ANY FRONTAL PRECIPITATION SUPPRESSED TO OUR SOUTH AND ONLY WEAK NORTHERN STREAM WAVES TO OUR NORTH TO GENERATE ANY PRECIPITATION. SO...KEPT THE POPS LOW THROUGH THE PERIOD AND ANY LIGHT PRECIPITATION WOULD LIKELY BE SNOW AS 850 HPA TEMPS STAY BELOW 0C. BEST CHANCE OF ANY PRECIPITATION WOULD BE IN NORTHERN AREAS SHOULD ONE OF THE NORTHERN STREAM WAVES PROVE TO BE STRONGER THAN GUIDANCE IMPLIES. A RIDGE IS FORECAST TO BUILD OVER THE REGION TUESDAY INTO WEDNESDAY AND OUR LOWER TROPOSPHERE TEMPERATURES SHOULD GET AT LEAST SLIGHTLY....ABOVE NORMAL....BOTH TUESDAY INTO WEDNESDAY. THIS SHOULD PROVIDE AT LEAST 2 DAYS OF NEAR SEASONAL TEMPERATURES FOR A CHANGE. RELATIVELY WARM DAYS AND COLD NIGHTS...A GOOD SLOW WAY TO MELT SNOW WITHOUT FLOODING. THE NAEFSBC AND GEFSBC SUGGEST A FRONTAL PASSAGE THURSDAY WITH SLIGHTLY COLDER TEMPERATURES AS ANOTHER HIGH PRESSURE SYSTEM IS FORECAST TO MOVE OVER THE NORTHEASTERN UNITED STATES THURSDAY INTO SATURDAY NEXT WEEK. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... MOISTURE OVERRUNNING A WAVY COLD FRONT TO THE SOUTH OF PA WILL BRING ANOTHER ROUND OF RAIN/SNOW MAINLY TO AREAS SOUTH OF I-80 OVERNIGHT INTO THURSDAY MORNING. WIDESPREAD MVFR/IFR WILL CONTINUE ACROSS SRN AIRFIELDS OVERNIGHT THROUGH AT LEAST MID DAY THURSDAY BEFORE DRIER AIR BEGINS MOVING INTO THE REGION FROM THE WEST AND NORTH BRINGING IMPROVING CONDITIONS. NORTHERN SITES...ESPECIALLY KBFD MAY STAY MVFR OR HIGHER. TRANSITION FROM RAIN TO SNOW OCCURRING ACROSS KMDT ATTM. THIS SHOULD BE COMPLETE OVER THE NEXT 2 TO 3 HOURS WITH SNOW THEN CONTINUING THROUGH THE NIGHT. OUTLOOK... THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ017>019-049-051-053. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR PAZ024>028-034-035-050-052-056>059-063. WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ033- 036-064>066. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...GRUMM AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1249 AM EST THU MAR 5 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA THIS EVENING AND EARLY THURSDAY. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... WATER VAPOR/SATL DERIVED PWAT IMAGERY SHOWING AN ATMOSPHERIC RIVER OF ANOMALOUS PWATS EXTENDING FROM THE S PACIFIC OCEAN NEWRD INTO THE MISS VALLEY AND EVENTUALLY PA. THIS DEEP MOISTURE PLUME IS OVERRUNNING AN EXPANSIVE ARCTIC HIGH PRES TO THE NORTH...CREATING A BAND OF MIXED PRECIP FROM THE PLAINS INTO SOUTHERN PA. AS OF 02Z...PTYPE IS LGT RAIN ACROSS MOST OF SOUTHERN PA. HOWEVER...THE HIGHER TERRAIN FROM KFIG/KUNV SOUTH THRU KJST IS NOW REPORTING SNOW. AS WEAK WAVE OF LOW PRES PASSES SOUTH OF PA OVERNIGHT...PRECIP WILL EXPAND NORTH ACROSS THE STATE...WHILE COLDER AIR FILTERS IN ON NW FLOW. ALL LATEST MDL DATA POINTING TOWARD A GENERAL 2-4 INCH SNOWFALL ACROSS THE SOUTHERN COUNTIES OVERNIGHT...WITH PERHAPS A FEW AMTS NR 6 ALONG THE MD BORDER. 18Z MDL SOUNDINGS AND LATEST HRRR OUTPUT BOTH INDICATE THERMAL PROFILES WILL REMAIN TOO WARM FOR SNOW ACROSS THE LOWER SUSQ VALLEY UNTIL ARND 06Z. THUS...HAVE WILL LOWER AMTS THERE. TEMPERATURES AT 02Z RUNNING FROM THE U20S ACROSS THE NW MTNS...TO THE U30S IN THE SOUTHERN VALLEYS. HOWEVER...ARRIVAL OF PRECIP AND LOW LVL COLD ADVECTION WILL DROP READINGS TO THE TEENS AND 20S BY DAWN. A STRONG JET ENTRANCE REGION ALOFT WILL SLIDE BY JUST NORTH OF THE REGION TONIGHT AND THURSDAY...SUPPORTING AN AREA OF POTENT LOW-MID LEVEL FRONTOGENETIC FORCING. MODELS RESPOND BY BRINGING A FAIRLY PROLONGED PERIOD OF PRECIP TO MY FAR SOUTHERN ZONES. 21Z SREF AND 18Z GEFS THREAT PAGES STILL PAINT MY FAR SERN ZONES AS HAVING THE HIGHEST RISK FOR HEAVY SNOW THROUGH MID DAY THURSDAY...WITH A RATHER SHARP CUT OFF ON THE BACK SIDE UP INTO THE CENTRAL MOUNTAINS. HOWEVER...LEANING TOWARD THE MORE RECENT 00Z AND HRRR GUIDANCE...WHICH INDICATES SLIGHTLY LOWER AMTS THAN EARLIER EXPECTED. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... BLEND OF LATEST MDL DATA INDICATE SNOW WILL TAPER OFF BY LATE AM ACROSS THE CENTRAL COUNTIES...AND MAY LAST UNTIL LATE AFTN ACROSS YORK/LANCASTER COUNTIES. ARCTIC HIGH AND ASSOC DRY AIR MASS WILL ARRIVE EARLY OVR THE NW COUNTIES...RESULTING IN DRY/COLD WX THE ENTIRE DAY UP THERE. SOME PARTIAL CLEARING APPEARS LIKELY ACROSS THE NW COUNTIES LATE IN THE DAY. ELSEWHERE...MDL SOUNDINGS INDICATE A MID LVL CLOUD DECK WILL LINGER EVEN AFTER THE SNOW ENDS. OVERCAST SKIES AND COLD ADVECTION WILL LIKELY BLUNT ANY DIURNAL WARMING AND RESULT IN STEADY TEMPS THRU EARLY AFTN...THEN FALLING TEMPS LATE. CONSALL OUTPUT SUPPORTS DAYTIME TEMPS FROM ONLY ARND 10F ACROSS THE NW MTNS...TO THE L20S ACROSS THE SOUTHEAST COUNTIES...ANOTHER EXCEPTIONALLY COLD DAY FOR THE TIME OF YEAR. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE AND BELOW NORMAL LOW-LEVEL TEMPERATURES WILL DOMINATE THE REGION THURSDAY NIGHT INTO LATE FRIDAY. UNSEASONABLY COLD AIR...PERHAPS THE LAST OF THE SIGNIFICANT ARCTIC SURGES OF OUR ENDLESS WINTER. BASED ON THE LOW TEMPERATURES NEAR AND BELOW 0F AND THE WINDS...THE POTENTIAL EXISTS FOR SOME AREAS TO EXPERIENCE WIND CHILLS OVERNIGHT THURSDAY INTO FRIDAY WHICH MIGHT REQUIRE AN ADVISORY ACROSS THE NORTHERN TIER COUNTIES. SATURDAY THE TEMPERATURES AT 850 MB RETURN CLOSER TO NORMAL AND HIGH PRESSURE DRIFTS TO OUR SOUTH. PENNSYLVANIA SHOULD REMAIN NORTH OF THIS WEAK HIGH....CUTTING OFF ANY MOISTURE TO THE SOUTH...KEEPING THE REGION IN WEAK WESTERLY FLOW INTO MONDAY. THE PERIOD SHOULD BE RELATIVELY DRY WITH ANY FRONTAL PRECIPITATION SUPPRESSED TO OUR SOUTH AND ONLY WEAK NORTHERN STREAM WAVES TO OUR NORTH TO GENERATE ANY PRECIPITATION. SO...KEPT THE POPS LOW THROUGH THE PERIOD AND ANY LIGHT PRECIPITATION WOULD LIKELY BE SNOW AS 850 HPA TEMPS STAY BELOW 0C. BEST CHANCE OF ANY PRECIPITATION WOULD BE IN NORTHERN AREAS SHOULD ONE OF THE NORTHERN STREAM WAVES PROVE TO BE STRONGER THAN GUIDANCE IMPLIES. A RIDGE IS FORECAST TO BUILD OVER THE REGION TUESDAY INTO WEDNESDAY AND OUR LOWER TROPOSPHERE TEMPERATURES SHOULD GET AT LEAST SLIGHTLY....ABOVE NORMAL....BOTH TUESDAY INTO WEDNESDAY. THIS SHOULD PROVIDE AT LEAST 2 DAYS OF NEAR SEASONAL TEMPERATURES FOR A CHANGE. RELATIVELY WARM DAYS AND COLD NIGHTS...A GOOD SLOW WAY TO MELT SNOW WITHOUT FLOODING. THE NAEFSBC AND GEFSBC SUGGEST A FRONTAL PASSAGE THURSDAY WITH SLIGHTLY COLDER TEMPERATURES AS ANOTHER HIGH PRESSURE SYSTEM IS FORECAST TO MOVE OVER THE NORTHEASTERN UNITED STATES THURSDAY INTO SATURDAY NEXT WEEK. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... MOISTURE OVERRUNNING A WAVY COLD FRONT TO THE SOUTH OF PA WILL BRING ANOTHER ROUND OF RAIN/SNOW MAINLY TO AREAS SOUTH OF I-80 OVERNIGHT INTO THURSDAY MORNING. WIDESPREAD MVFR/IFR WILL CONTINUE ACROSS SRN AIRFIELDS OVERNIGHT THROUGH AT LEAST MID DAY THURSDAY BEFORE DRIER AIR BEGINS MOVING INTO THE REGION FROM THE WEST AND NORTH BRINGING IMPROVING CONDITIONS. NORTHERN SITES...ESPECIALLY KBFD MAY STAY MVFR OR HIGHER. TRANSITION FROM RAIN TO SNOW OCCURRING ACROSS KMDT ATTM. THIS SHOULD BE COMPLETE OVER THE NEXT 2 TO 3 HOURS WITH SNOW THEN CONTINUING THROUGH THE NIGHT. OUTLOOK... THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE. FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ017>019-049-051-053. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR PAZ024>028-034-035-050-052-056>059-063. WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ033- 036-064>066. && $$ SYNOPSIS...GRUMM/LA CORTE NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD/LA CORTE LONG TERM...GRUMM AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1154 PM CST WED MAR 4 2015 .DISCUSSION... SEE THE 06Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... THE COLD FRONT WAS WELL OFFSHORE AT 0530Z. THE MAIN ISSUES ARE WINDS...IFR TO LIFR CEILINGS...AND THE POSSIBILITY FOR A MIX OF WINTRY PRECIPITATION AT KCLL AND KUTS BEFORE SUNRISE.. THE PRECIP TYPE OF BOTH KCLL AND KUTS LOOKS TO BE AT LEAST A MIX OF RAIN AND ICE PELLETS THROUGH 10Z...AND IF THE TEMPERATURES FALL ENOUGH FREEZING RAIN OR DRIZZLE MAY BECOME AN ISSUE. THE HIGH RESOLUTION MODELS END THE PRECIPITATION CHANCES BY AROUND 13Z AT BOTH SITES AND LIFT THE CEILINGS TO VFR BY 19Z. FOR THE REMAINING SITES...THE RAIN SHOULD END BY MID MORNING FROM KCXO THROUGH THE METRO HOUSTON SITES AND MAY LINGER ALONG THE COASTAL SITES THROUGH MID AFTERNOON. THE CEILINGS SHOULD THEN LIFT ACROSS THESE AREAS DURING THE MID AND LATE AFTERNOON. REGARDING THE WINDS...STRONG WIND GUSTS ARE POSSIBLE OVER MANY INLAND LOCATIONS THROUGH ABOUT 15Z AND THEN SLOWLY DIMINISH. THE WINDS WILL SLOWLY DIMINISH ALONG THE COAST DURING THE MID AND LATE AFTERNOON. 40 && .PREV DISCUSSION... /ISSUED 925 PM CST WED MAR 4 2015/ UPDATE... SEE EVENING UPDATE. DISCUSSION... A COLD FRONT IS MOVING ACROSS SE TX AND WILL LIKELY CLEAR THE COAST BY 11 PM. TEMPERATURES ARE FALLING QUICKLY BEHIND THE BOUNDARY AND CALDWELL IS ALREADY DOWN TO 37 DEGREES. LEANED TOWARD THE RUC FOR HOURLY TEMPS OVERNIGHT SINCE IT IS THE ONLY MODEL REMOTELY CLOSE TO CURRENT OBS. HAVE SOME CONCERN THAT MODELS ARE NOT COLD ENOUGH AND THAT COULD BE A REAL PROBLEM OVER THE NORTHERN ZONES BY MORNING. WATER VAPOR IMAGERY SHOWS A DISTURBANCE OVER NORTHERN MEXICO. THIS FEATURE WILL APPROACH SE TX AROUND 09Z AND WILL GENERATE A SWATH OF PRECIPITATION ACROSS MOST OF SE TX. HIGH POPS ARE ALREADY IN PLACE BUT BUMPED UP QPF TOWARD THE COAST AND RAISED POPS FOR EARLY THURSDAY MORNING ALONG THE COAST. SINCE PRECIP WILL BE A BIT HEAVIER AND LAST A BIT LONGER THAN PREVIOUSLY FCST...HAVE MORE CONCERN THAT WINTER PRECIP MAY DEVELOP FOR A TIME OVER THE NORTHERN ZONES. AM HESITANT TO MAKE BIG CHANGES AT THIS TIME BUT RAP AND NAM FORECAST SOUNDINGS SHOW A FAIRLY DEEP FREEZING LAYER BETWEEN 500-3500 FEET WHICH APPEARS COLD ENOUGH TO CHANGE PRECIP TO SLEET. WILL BE WATCHING TRENDS VERY CLOSELY AND A WINTER WEATHER ADVISORY FOR THE NORTHERN ZONES IS NOT OUT OF THE QUESTION. WIND ADVISORY AND GALE WARNINGS LOOK ON TARGET SO NO CHANGES PLANNED. NEW ZONES OUT BY 945 PM. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 33 37 27 47 32 / 90 40 10 10 10 HOUSTON (IAH) 37 41 29 49 34 / 80 60 10 10 10 GALVESTON (GLS) 42 43 35 47 41 / 60 50 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...WIND ADVISORY UNTIL NOON CST THURSDAY FOR THE FOLLOWING ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS... COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS... JACKSON...MADISON...MATAGORDA...WALLER...WASHINGTON... WHARTON. GM...LOW WATER ADVISORY FROM NOON TO 2 PM CST THURSDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. GALE WARNING UNTIL NOON CST THURSDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. GALE WARNING UNTIL 3 PM CST THURSDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...43 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1031 AM EST THU MAR 5 2015 .SYNOPSIS... A COUPLE OF WAVES OF LOW PRESSURE WILL TRACK SOUTHEAST OF THE REGION TODAY AND THIS EVENING. A HIGH PRESSURE SYSTEM WILL MOVE INTO THE REGION ON FRIDAY AND THEN SINK TO THE SOUTHEAST ON SATURDAY. A WEAK CLIPPER TYPE LOW PRESSURE SYSTEM SHOULD PASS NORTH OF THE AREA ON SATURDAY NIGHT FOLLOWED BRIEFLY BY ANOTHER HIGH PRESSURE SYSTEM ON SUNDAY. A COLD FRONT SHOULD PASS THROUGH THE REGION ON MONDAY. ANOTHER HIGH PRESSURE SYSTEM SHOULD THEN BUILD INTO THE AREA ON TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SNOW IS IN PROGRESS ACROSS THE REGION WITH AREAS ACROSS SOUTHEAST NJ AND THE SOUTHERN DELMARVA CHANGING FROM SLEET AND RAIN TO SNOW IN THE NEXT FEW HOURS. THE BACK EDGE OF THE SNOW IS APPROACHING THE NORTHWEST PARTS OF THE REGION. CAA WILL CONTINUE TO PUSH INTO THE REGION BEHIND A COLD FRONT WITH A CONTINUING STREAM OF OVERRUNNING MOISTURE. TEMPERATURES WILL CONTINUE TO DROP TODAY ACROSS THE AREA AND ONLY A FEW ADJUSTMENTS WERE MADE WITH THE 9:30 AM UPDATE. PRECIPITATION SHOULD END VERY SLOWLY FROM NORTH TO SOUTH THIS AFTERNOON. WIND GUSTS AROUND 20 MPH HAVE ALSO BEEN REPORTED IN SPOTS AND THESE WERE INCREASED WITH THE 9:30 AM UPDATE. ONTO SNOW AMOUNTS IN THE ADVISORY AREA A FEW INCHES HAVE ALREADY FALLEN WITH THE POTENTIAL FOR SOME ADDITIONAL ACCUMULATION WITH TOTALS STILL LOOKING TO AVERAGE UNDER WARNING CRITERIA. *WE UPGRADED THE LEHIGH VALLEY AND SURROUDING AREA TO A WINTER STORM WARNING WITH A 10:30 AM UPDATE. WE HAVE ALREADY GOTTEN REPORTS OF 3-5 INCHES WITH ANOTHER BAND OF MODERATE SNOW MOVING INTO THE AREA FOR THE LATE MORNING AREAS. NAM HAS AN ADDITIONAL.1-.25 QPF WHICH WOULD PUSH TOTALS TO AROUND 6 INCHES OF SNOW.* FURTHER SOUTH TOWARD THE PHILADELPHIA METRO AREA MODERATE TO HEAVY SNOW BANDS HAVE SETUP ACROSS THIS REGION WITH REPORTS OF 1 TO AS MUCH AS 2 INCHES PER HOUR FOR SHORT INTERVALS. THE RAP AND HRRR BOTH INDICATE THAT THESE MESOSCALE BANDS WILL BE SOMEWHAT PROGRESSIVE BUT CONTINUE THROUGHOUT THE DAY TODAY. THESE BANDS ARE CAUSED BY SIGNIFICANT FRONTGENETICAL FORCING AND AMPLE ISENTROPIC LIFT. STORM TOTALS OF 6-8 INCHES STILL LOOK ON TRACK ATTM. ALSO PLEASE REFER TO MCD 124 FROM THE SPC AND THE SPS WE HAVE IN EFFECT. IN THE DELMARVA AND SOUTHEAST NJ, THE 9:30 AM UPDATE SLOWS THE CHANGEOVER AN HOUR OR SO. HOWEVER STILL DO NOT THINK THIS WILL CUT INTO TOTALS EXTENSIVELY ATTM. THIS IS DUE TO THE SAME MESOSCALE BANDING SIGNATURES SINKING FURTHER SOUTH FOR THE AFTERNOON HOURS. THIS IS PICKED UP WELL BY THE RAP, HRRR AND 06Z 800-600 MB FRONTGENETICAL FORCING ON THE 06Z NAM FROM EARLIER TODAY. SNOWFALL MAY ALSO FALL AROUND AN INCH FOR A TIME THIS AFTERNOON LEADING TO 4-8 INCHES OF SNOW BY EVENING. ROAD CONDITIONS WILL CONTINUE TO DETERIORATE TODAY WITH THE SNOW, ALLOW EXTRA TIME IF YOU HAVE TO TRAVEL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... THE LAST OF THE STEADY SNOWS WILL PASS EAST OF THE FORECAST AREA THIS EVENING. SKIES WILL BE CLOUDY EARLY THEN THE CLOUDS WILL BREAK UP FROM N/W TO S/E OVERNIGHT. THE LACK OF CLOUDS LATE AND THE FRESH SNOW COVER SHOULD PRODUCE COLD TEMPS OVERNIGHT...WITH LOWS IN THE SINGLE DIGITS AND A FEW SUB-ZERO READINGS FAR NORTH. WIND CHILLS MAY DROP TO NEAR -12 TO -15 ACROSS MOUNT POCONO...BUT REMAIN MORE LIKE 0 TO -10 ELSEWHERE. WINDS WILL BE MOSTLY NRLY AT 5 TO 10 MPH. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... THE GFS INITIALIZATION LOOKED SLIGHTLY BETTER THERMALLY, BUT IT WAS A COLD OP RUN IN COMPARISON TO ITS ENSEMBLE MEAN AND OTHER MODELS. OVERALL AFTER TODAY, THE LONG TERM IS RELATIVELY QUIET WITH TEMPERATURES RETURNING TO NEAR NORMAL VALUES AND NOT MUCH PCPN EXPECTED. A BRIGHT SUNNY DAY IS EXPECTED ON FRIDAY WITH NOT MUCH WIND. THE ONE CATCH IS THAT TEMPERATURES WILL BE WELL BELOW AVERAGE, EVEN IF IT WERE STILL JANUARY. MAX TEMPS ARE CLOSE TO THE FULL SUN MACROS AND THE HIGHER NAM STAT GUIDANCE. ON FRIDAY NIGHT WE CONTINUED THE IDEA OF GOING EITHER WITH THE LOWER STAT GUIDANCE IN URBAN AREAS OR BELOW ALL FOR MINS GIVEN WE ARE EXPECTING RADIATIONAL COOLING CONDITIONS. THERE IS A SHORT WAVE TROF THAT MIGHT SPILL SOME CLOUDS THROUGH PART OF THE NIGHT, ONLY REASON WE DID NOT GO EVEN LOWER. SATURDAY THE AIR MASS RECOVERY WILL START AS A HIGH PRESSURE SYSTEM REACHES THE COAST. THERE SHOULD BE MORE CLOUDS AROUND ASSOCIATED WITH THE WAA PHASE OF THE CLIPPER WHICH SHOULD SLOW TEMP RISE A BIT. WE ARE CLOSER TO NAM STAT GUIDANCE FOR MAX TEMPS AS BY NOW THE GEFS MEAN IS WARMER THAN THE OP GFS. ON SATURDAY NIGHT, CONTINUED WITH THE IDEA THAT THE WEAKENING CLIPPER MIGHT BRING SOME SNOW SHOWERS TO THE NORTHERN PART OF OUR CWA. PRECIPITATION INTENSITY AS OF NOW APPEARS LIGHT IF THEY MAKE IT. SUNDAY, THE MODERATION TREND IS EXPECTED TO CONTINUE AS THE CLIPPER`S DEMISE SHOULD NOT BRING ANY COLDER AIR BACK INTO THE REGION. A NORTHERN STREAM COLD FRONT COULD BRING THE CHANCE OF SHOWERS BACK INTO THE AREA ON MONDAY AND BY THEN IT MIGHT BE WARM ENOUGH FOR THE PTYPE TO FALL AS RAIN. A SOUTHERN STREAM LOW PRESSURE SYSTEM IS EXPECTED TO REMAIN SEPARATE WITH ITS PREDICTED PCPN FOR NOW REMAINING SOUTHEAST OF OUR AREA. THEN A HIGH PRESSURE SYSTEM ENTERING FROM THE PACIFIC OCEAN (INSTEAD OF TAKING THE POLAR ROUTE) FOR A CHANGE IS EXPECTED TO BRING TEMPERATURES CLOSE TO SEASONAL LEVELS FOR TUESDAY AND WEDNESDAY. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDITIONS WILL CONTINUE TO DETERIORATE THIS MORNING WITH CIGS/VSBYS IN THE IFR/LIFR RANGE IN SNOW. THE CHANGE- OVER WILL OCCUR BY 15Z AT ACY WITH MOST LOCATIONS SEEING SNOW WELL INTO THE AFTERNOON. SOME LOWER VSBYS AROUND 1/4 MILE COULD BE OBSERVED AS WELL LOCALLY FOR SHORT INTERVALS, WHICH WERE NOT INCLUDED IN THE TAFS. ALSO, ISOLATED WIND GUSTS AROUND 20 KNOTS ARE POSSIBLE TODAY BUT COVERAGE LOOKS LOW ENOUGH NOT TO MENTION IN TAFS ATTM. IMPROVEMENT TO MVFR IS POSSIBLE AFTER 20Z WITH VFR CONDITIONS AROUND 00-03Z AS CLOUDS CLEAR. RUNWAY SNOW ACCUMULATION IS POSSIBLE TO LIKELY TODAY. OUTLOOK... FRIDAY THROUGH SATURDAY...PRIMARILY VFR. SATURDAY NIGHT...SOME MVFR CIGS POSSIBLE, MAINLY NORTH ALONG WITH A LOW CHANCE OF SNOW SHOWERS. SUNDAY AND SUNDAY NIGHT...PRIMARILY VFR. MONDAY...PRIMARILY VFR, LOCALLY MVFR IN SHOWERS. && .MARINE... WE WILL KEEP THE SCA FLAG FOR TODAY...AND EXTEND THE EXPIRATION TIME INTO TONIGHT. WINDS AND SEAS WILL INCREASE ACROSS THE WATERS AS CAA CONTINUES. IT APPEARS THAT GUSTS IN THE 25 TO 30 KNT RANGE ARE POSSIBLE ACROSS THE OCEAN WATERS AND AROUND 20 KTS ACROSS DEL BAY. THERE WILL BE RAIN/SNOW EARLY TODAY...THEN SNOW INTO THE AFTERNOON. FAIR WEATHER EXPECTED TONIGHT. OUTLOOK... FRIDAY AND FRIDAY NIGHT...CONDITIONS SHOULD RETURN TO SUB SMALL CRAFT ADVISORY LEVELS. FREEZING SPRAY IS LIKELY, NOT CONFIDENT ENOUGH ABOUT MODERATE FREEZING SPRAY OCCURRING ON FRIDAY MORNING TO ISSUE AN ADVISORY. SATURDAY THROUGH MONDAY...SUB SMALL CRAFT ADVISORY CONDITIONS ARE OUTLOOKED TO PREVAIL MAINLY DUE A COMBINATION OF RELATIVELY WEAK PRESSURE SYSTEMS AND ALSO WHERE THERE WILL BE STRONGER WINDS ABOVE THE BOUNDARY LEVEL, IT SHOULD BE AT TIMES WHEN THE AIR TEMPS WILL BE HIGHER THAN THE WATER TEMPS. && .HYDROLOGY... WITH THE TRANSITION BACK TO SNOW TODAY (IF NOT ALREADY), THE HYDROLOGICAL CONCERNS AT LEAST IN THE NEAR TERM ARE LESSENING. WE ARE STILL MONITORING GAGED SITES TO CHECK FOR JAMS. && .CLIMATE... CLIMATE: WITH A SNOWCOVER IN PLACE AND ANOTHER MODIFIED ARCTIC AIRMASS SETTLING INTO THE REGION AND RADIATIONAL COOLING OCCURRING, WE HAVE ANOTHER CHANCE FOR MORE RECORD LOWS ACROSS THE REGION. FRIDAY 3/6 RECORD LOWS ACY 10 1888 PHL 10 1978 ILG 11 1926 ABE 7 1960 TTN 7 1872 GED 10 1978 RDG 7 1978 MPO -5 1909 THE CURRENT FORECAST CURRENTLY HAS MOST LOCATIONS BREAKING THERE RECORD LOW ON FRIDAY MORNING. THE ONE EXCEPTION WOULD BE MOUNT POCONO. SATURDAY 3/7 RECORD LOWS ACY 10 1890 PHL 9 1960 ILG 11 1960 ABE 1 1960 TTN 7 1890 GED 3 1960 RDG 10 1989 MPO -18 1911 ASIDE FROM ATLANTIC CITY, MOST LOCATIONS ARE FORECASTED TO BE SEVERAL DEGREES WARMER THAN THE RECORD LOWS FOR SATURDAY MORNING. RECORD DAILY SNOWFALL FOR THURSDAY MARCH 5 KACY 0.3 - 1960 KILG 3.7 - 1981 KABE 7.0 - 1917 KPHL 8.8 - 1981 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ060>062-070-071-101>106. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054- 055. NJ...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ007>010-012>027. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001. DE...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ008- 012-015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ450>455. && $$ SYNOPSIS...GIGI NEAR TERM...GAINES SHORT TERM...O`HARA LONG TERM...GIGI AVIATION...GAINES/GIGI MARINE...GIGI/O`HARA HYDROLOGY... CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
946 AM EST THU MAR 5 2015 .SYNOPSIS... A COUPLE OF WAVES OF LOW PRESSURE WILL TRACK SOUTHEAST OF THE REGION TODAY AND THIS EVENING. A HIGH PRESSURE SYSTEM WILL MOVE INTO THE REGION ON FRIDAY AND THEN SINK TO THE SOUTHEAST ON SATURDAY. A WEAK CLIPPER TYPE LOW PRESSURE SYSTEM SHOULD PASS NORTH OF THE AREA ON SATURDAY NIGHT FOLLOWED BRIEFLY BY ANOTHER HIGH PRESSURE SYSTEM ON SUNDAY. A COLD FRONT SHOULD PASS THROUGH THE REGION ON MONDAY. ANOTHER HIGH PRESSURE SYSTEM SHOULD THEN BUILD INTO THE AREA ON TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SNOW IS IN PROGRESS ACROSS THE REGION WITH AREAS ACROSS SOUTHEAST NJ AND THE SOUTHERN DELMARVA CHANGING FROM SLEET AND RAIN TO SNOW IN THE NEXT FEW HOURS. THE BACK EDGE OF THE SNOW IS APPROACHING THE NORTHWEST PARTS OF THE REGION. CAA WILL CONTINUE TO PUSH INTO THE REGION BEHIND A COLD FRONT WITH A CONTINUING STREAM OF OVERRUNNING MOISTURE. TEMPERATURES WILL CONTINUE TO DROP TODAY ACROSS THE AREA AND ONLY A FEW ADJUSTMENTS WERE MADE WITH THE 9:30 AM UPDATE. PRECIPITATION SHOULD END VERY SLOWLY FROM NORTH TO SOUTH THIS AFTERNOON. WIND GUSTS AROUND 20 MPH HAVE ALSO BEEN REPORTED IN SPOTS AND THESE WERE INCREASED WITH THE 9:30 AM UPDATE. ONTO SNOW AMOUNTS IN THE ADVISORY AREA A FEW INCHES HAVE ALREADY FALLEN WITH THE POTENTIAL FOR SOME ADDITIONAL ACCUMULATION WITH TOTALS STILL LOOKING TO AVERAGE UNDER WARNING CRITERIA. FURTHER SOUTH TOWARD THE PHILADELPHIA METRO AREA MODERATE TO HEAVY SNOW BANDS HAVE SETUP ACROSS THIS REGION WITH REPORTS OF 1 TO AS MUCH AS 2 INCHES PER HOUR FOR SHORT INTERVALS. THE RAP AND HRRR BOTH INDICATE THAT THESE MESOSCALE BANDS WILL BE SOMEWHAT PROGRESSIVE BUT CONTINUE THROUGHOUT THE DAY TODAY. THESE BANDS ARE CAUSED BY SIGNIFICANT FRONTGENETICAL FORCING AND AMPLE ISENTROPIC LIFT. STORM TOTALS OF 6-8 INCHES STILL LOOK ON TRACK ATTM. ALSO PLEASE REFER TO MCD 124 FROM THE SPC AND THE SPS WE HAVE IN EFFECT. IN THE DELMARVA AND SOUTHEAST NJ, THE 9:30 AM UPDATE SLOWS THE CHANGEOVER AN HOUR OR SO. HOWEVER STILL DO NOT THINK THIS WILL CUT INTO TOTALS EXTENSIVELY ATTM. THIS IS DUE TO THE SAME MESOSCALE BANDING SIGNATURES SINKING FURTHER SOUTH FOR THE AFTERNOON HOURS. THIS IS PICKED UP WELL BY THE RAP, HRRR AND 06Z 800-600 MB FRONTGENETICAL FORCING ON THE 06Z NAM FROM EARLIER TODAY. SNOWFALL MAY ALSO FALL AROUND AN INCH FOR A TIME THIS AFTERNOON LEADING TO 4-8 INCHES OF SNOW BY EVENING. ROAD CONDITIONS WILL CONTINUE TO DETERIORATE TODAY WITH THE SNOW, ALLOW EXTRA TIME IF YOU HAVE TO TRAVEL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... THE LAST OF THE STEADY SNOWS WILL PASS EAST OF THE FORECAST AREA THIS EVENING. SKIES WILL BE CLOUDY EARLY THEN THE CLOUDS WILL BREAK UP FROM N/W TO S/E OVERNIGHT. THE LACK OF CLOUDS LATE AND THE FRESH SNOW COVER SHOULD PRODUCE COLD TEMPS OVERNIGHT...WITH LOWS IN THE SINGLE DIGITS AND A FEW SUB-ZERO READINGS FAR NORTH. WIND CHILLS MAY DROP TO NEAR -12 TO -15 ACROSS MOUNT POCONO...BUT REMAIN MORE LIKE 0 TO -10 ELSEWHERE. WINDS WILL BE MOSTLY NRLY AT 5 TO 10 MPH. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... THE GFS INITIALIZATION LOOKED SLIGHTLY BETTER THERMALLY, BUT IT WAS A COLD OP RUN IN COMPARISON TO ITS ENSEMBLE MEAN AND OTHER MODELS. OVERALL AFTER TODAY, THE LONG TERM IS RELATIVELY QUIET WITH TEMPERATURES RETURNING TO NEAR NORMAL VALUES AND NOT MUCH PCPN EXPECTED. A BRIGHT SUNNY DAY IS EXPECTED ON FRIDAY WITH NOT MUCH WIND. THE ONE CATCH IS THAT TEMPERATURES WILL BE WELL BELOW AVERAGE, EVEN IF IT WERE STILL JANUARY. MAX TEMPS ARE CLOSE TO THE FULL SUN MACROS AND THE HIGHER NAM STAT GUIDANCE. ON FRIDAY NIGHT WE CONTINUED THE IDEA OF GOING EITHER WITH THE LOWER STAT GUIDANCE IN URBAN AREAS OR BELOW ALL FOR MINS GIVEN WE ARE EXPECTING RADIATIONAL COOLING CONDITIONS. THERE IS A SHORT WAVE TROF THAT MIGHT SPILL SOME CLOUDS THROUGH PART OF THE NIGHT, ONLY REASON WE DID NOT GO EVEN LOWER. SATURDAY THE AIR MASS RECOVERY WILL START AS A HIGH PRESSURE SYSTEM REACHES THE COAST. THERE SHOULD BE MORE CLOUDS AROUND ASSOCIATED WITH THE WAA PHASE OF THE CLIPPER WHICH SHOULD SLOW TEMP RISE A BIT. WE ARE CLOSER TO NAM STAT GUIDANCE FOR MAX TEMPS AS BY NOW THE GEFS MEAN IS WARMER THAN THE OP GFS. ON SATURDAY NIGHT, CONTINUED WITH THE IDEA THAT THE WEAKENING CLIPPER MIGHT BRING SOME SNOW SHOWERS TO THE NORTHERN PART OF OUR CWA. PRECIPITATION INTENSITY AS OF NOW APPEARS LIGHT IF THEY MAKE IT. SUNDAY, THE MODERATION TREND IS EXPECTED TO CONTINUE AS THE CLIPPER`S DEMISE SHOULD NOT BRING ANY COLDER AIR BACK INTO THE REGION. A NORTHERN STREAM COLD FRONT COULD BRING THE CHANCE OF SHOWERS BACK INTO THE AREA ON MONDAY AND BY THEN IT MIGHT BE WARM ENOUGH FOR THE PTYPE TO FALL AS RAIN. A SOUTHERN STREAM LOW PRESSURE SYSTEM IS EXPECTED TO REMAIN SEPARATE WITH ITS PREDICTED PCPN FOR NOW REMAINING SOUTHEAST OF OUR AREA. THEN A HIGH PRESSURE SYSTEM ENTERING FROM THE PACIFIC OCEAN (INSTEAD OF TAKING THE POLAR ROUTE) FOR A CHANGE IS EXPECTED TO BRING TEMPERATURES CLOSE TO SEASONAL LEVELS FOR TUESDAY AND WEDNESDAY. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDITIONS WILL CONTINUE TO DETERIORATE THIS MORNING WITH CIGS/VSBYS IN THE IFR/LIFR RANGE IN SNOW. THE CHANGE- OVER WILL OCCUR BY 15Z AT ACY WITH MOST LOCATIONS SEEING SNOW WELL INTO THE AFTERNOON. SOME LOWER VSBYS AROUND 1/4 MILE COULD BE OBSERVED AS WELL LOCALLY FOR SHORT INTERVALS, WHICH WERE NOT INCLUDED IN THE TAFS. ALSO, ISOLATED WIND GUSTS AROUND 20 KNOTS ARE POSSIBILE TODAYBUT COVERAGE LOOKS LOW ENOUGH NOT TO MENTION IN TAFS ATTM. IMPROVEMENT TO MVFR IS POSSIBLE AFTER 20Z WITH VFR CONDITIONS AROUND 00-03Z AS CLOUDS CLEAR. RUNWAY SNOW ACCUMULATION IS POSSIBLE TO LIKELY TODAY. OUTLOOK... FRIDAY THROUGH SATURDAY...PRIMARILY VFR. SATURDAY NIGHT...SOME MVFR CIGS POSSIBLE, MAINLY NORTH ALONG WITH A LOW CHANCE OF SNOW SHOWERS. SUNDAY AND SUNDAY NIGHT...PRIMARILY VFR. MONDAY...PRIMARILY VFR, LOCALLY MVFR IN SHOWERS. && .MARINE... WE WILL KEEP THE SCA FLAG FOR TODAY...AND EXTEND THE EXPIRATION TIME INTO TONIGHT. WINDS AND SEAS WILL INCREASE ACROSS THE WATERS AS CAA CONTINUES. IT APPEARS THAT GUSTS IN THE 25 TO 30 KNT RANGE ARE POSSIBLE ACROSS THE OCEAN WATERS AND AROUND 20 KTS ACROSS DEL BAY. THERE WILL BE RAIN/SNOW EARLY TODAY...THEN SNOW INTO THE AFTERNOON. FAIR WEATHER EXPECTED TONIGHT. OUTLOOK... FRIDAY AND FRIDAY NIGHT...CONDITIONS SHOULD RETURN TO SUB SMALL CRAFT ADVISORY LEVELS. FREEZING SPRAY IS LIKELY, NOT CONFIDENT ENOUGH ABOUT MODERATE FREEZING SPRAY OCCURRING ON FRIDAY MORNING TO ISSUE AN ADVISORY. SATURDAY THROUGH MONDAY...SUB SMALL CRAFT ADVISORY CONDITIONS ARE OUTLOOKED TO PREVAIL MAINLY DUE A COMBINATION OF RELATIVELY WEAK PRESSURE SYSTEMS AND ALSO WHERE THERE WILL BE STRONGER WINDS ABOVE THE BOUNDARY LEVEL, IT SHOULD BE AT TIMES WHEN THE AIR TEMPS WILL BE HIGHER THAN THE WATER TEMPS. && .HYDROLOGY... WITH THE TRANSITION BACK TO SNOW TODAY (IF NOT ALREADY), THE HYDROLOGICAL CONCERNS AT LEAST IN THE NEAR TERM ARE LESSENING. WE ARE STILL MONITORING GAGED SITES TO CHECK FOR JAMS. && .CLIMATE... CLIMATE: WITH A SNOWCOVER IN PLACE AND ANOTHER MODIFIED ARCTIC AIRMASS SETTLING INTO THE REGION AND RADIATIONAL COOLING OCCURRING, WE HAVE ANOTHER CHANCE FOR MORE RECORD LOWS ACROSS THE REGION. FRIDAY 3/6 RECORD LOWS ACY 10 1888 PHL 10 1978 ILG 11 1926 ABE 7 1960 TTN 7 1872 GED 10 1978 RDG 7 1978 MPO -5 1909 THE CURRENT FORECAST CURRENTLY HAS MOST LOCATIONS BREAKING THERE RECORD LOW ON FRIDAY MORNING. THE ONE EXCEPTION WOULD BE MOUNT POCONO. SATURDAY 3/7 RECORD LOWS ACY 10 1890 PHL 9 1960 ILG 11 1960 ABE 1 1960 TTN 7 1890 GED 3 1960 RDG 10 1989 MPO -18 1911 ASIDE FROM ATLANTIC CITY, MOST LOCATIONS ARE FORECASTED TO BE SEVERAL DEGREES WARMER THAN THE RECORD LOWS FOR SATURDAY MORNING. RECORD DAILY SNOWFALL FOR THURSDAY MARCH 5 KACY 0.3 - 1960 KILG 3.7 - 1981 KABE 7.0 - 1917 KPHL 8.8 - 1981 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054- 055-061-062. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ060- 070-071-101>106. NJ...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001- 007-008. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ009- 010-012>027. DE...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ008- 012-015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ450>455. && $$ SYNOPSIS...GIGI NEAR TERM...GAINES SHORT TERM...O`HARA LONG TERM...GIGI AVIATION...GAINES/GIGI/O`HARA MARINE...GIGI/O`HARA HYDROLOGY... CLIMATE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1042 AM EST THU MAR 5 2015 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST TODAY AND PUSH OFFSHORE THIS EVENING. COLDER HIGH PRESSURE WILL BUILD OVER THE AREA THURSDAY NIGHT AND WILL PREVAIL INTO SUNDAY. NEXT WEEK...AN UNSETTLED PATTERN WILL DEVELOP BETWEEN A STATIONARY FRONT SOUTH AND EAST OF THE REGION AND HIGH PRESSURE CENTERED TO THE NORTH. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATE THIS MORNING...THE FORECAST AREA IS POSITIONED WELL WITHIN THE WARM SECTOR AND WARM SUN IS SPILL ACROSS MOST OF IT. VISIBLE SATELLITE IMAGERY SHOWS A WELL DEFINED AREA OF SEA FOG ALONG AND JUST OFF THE COAST...AND ANY FOG THAT HAD ADVECTED ONSHORE EARLIER HAS DISSIPATED WITH STRONG INSOLATION AND RETREATED BACK OVER THE COOLER SHELF WATERS. THE MAIN FORECAST ISSUE FOR TODAY REVOLVES AROUND THE APPROACHING COLD FRONT AND PRECIPITATION CHANCES ASSOCIATED WITH IT. THE COLD FRONT IS CURRENTLY INTERACTING WITH THE SOUTHERN APPALACHIANS AND SLIPPING INTO THE LEE. SURFACE OBSERVATIONS SHOW THE FRONT EXTENDS FROM CENTRAL NORTH CAROLINA...ACROSS THE UPSTATE AND DOWN THROUGH CENTRAL GEORGIA. RECENT RUNS OF THE HRRR AND RAP SEEM TO HAVE A GOOD HANDLE ON THE FRONT AS WELL AS THE CURRENT PRECIPITATION COVERAGE...AND THEY HAVE BEEN USED EXTENSIVELY FOR FORECAST UPDATES. MOST OF THE DAY WILL BE DRY UNTIL THE FRONT BEGINS ENTERING FROM THE WEST AROUND 2 PM. THE DAMPENING UPPER WAVE ALOFT WILL REMAIN TO THE WEST AND NORTHWEST OF THE AREA...AND THE FRONT WILL INCREASINGLY BECOME DISPLACED FROM ANY PVA ALOFT. THERE IS A POWERFUL 180 KT JET ALOFT AND THE REGION WILL BE SOLIDLY IN THE RIGHT ENTRANCE REGION OF IT...SO THAT WILL HELP PROVIDE BROAD ASCENT. BY THE TIME THE FRONT REACHES THE FORECAST AREA IT APPEARS THERE WILL BE MAINLY A BROKEN LINE OF SHOWERS JUST BEHIND THE LEADING EDGE. THERE CONTINUES TO BE A SLIGHT CHANCE FOR THUNDER...ESPECIALLY GIVEN THE INCREASINGLY WARM SURFACE TEMPERATURES. IT WILL BE A BREEZY DAY WITH WINDS GUSTING TO AS HIGH AS 35 MPH AT TIMES. FINALLY...IT WILL ONCE AGAIN BE ANOTHER AFTERNOON WITH WELL ABOVE NORMAL TEMPERATURES. IN FACT...WE WILL LIKELY COME CLOSE TO RECORDS AT KCHS AND KSAV. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... TONIGHT...RAIN CHANCES WILL STEADILY END FROM WEST-EAST THIS EVENING AS THE COLD FRONT PUSHES THROUGH. THE BULK OF THE MEASURABLE RAINS WILL BE OFFSHORE 9 PM TO MIDNIGHT WITH ONLY ISOLATED TO PERHAPS SCATTERED SHOWERS LINGERING THROUGH EARLY FRIDAY. IN THE WAKE OF THE PRIMARY RAIN BAND...LOW CEILINGS AND PERIODS OF DRIZZLE WILL FILL IN AS COLDER AIR PUSHES SOUTH. TEMPERATURES COULD BE NEAR FREEZING ACROSS UPPER PORTIONS OF DORCHESTER AND BERKELEY COUNTIES AFTER 4-5 AM. ALTHOUGH SOUNDINGS SHOW MID-LEVEL MOISTURE QUICKLY SCOURING OUT BY THIS TIME...DEEP MOISTURE WITHIN THE BOUNDARY LAYER WILL SUPPORT PERIODS OF DRIZZLE. THIS OPENS THE POSSIBILITY FOR A LITTLE FREEZING DRIZZLE BY SUNRISE FRIDAY...ROUGHLY ALONG AND NORTH OF SAINT GEORGE- RIDGEVILLE-HUGER-SHULERVILLE LINE. WITH ONLY MARGINALLY COLD CONDITIONS AND TEMPERATURES HOLDING RIGHT AT FREEZING... SIGNIFICANT IMPACTS APPEAR UNLIKELY ATTM. HOWEVER...A VERY LIGHT GLACE ON ELEVATED SURFACES SUCH AS TREES...METAL OBJECTS AS WELL AS SOME BRIDGES AND OVERPASSES CAN NOT BE COMPLETELY RULED OUT. GROUND CONDITIONS WILL BE TOO WARM TO SUPPORT ICE ACCUMULATIONS OTHERWISE...WHICH INCLUDES NON-ELEVATED ROADWAYS. GIVEN THE MARGINAL NATURE OF THIS EVENT...THE FORECAST WILL CALL FOR PERIODS OF DRIZZLE WITH A CHANCE OF FREEZING DRIZZLE IN THE AFOREMENTIONED AREAS. THE RISK FOR FREEZING DRIZZLE WILL SURGE SOUTH AFTER SUNRISE AS SUBFREEZING WET-BULB TEMPERATURES ADVECT SOUTH. LOWS WILL RANGE FROM AROUND FREEZING FAR NORTH TO THE LOWER-MID 40S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. ONE COULD ARGUE THAT A FREEZE WARNING IS NEEDED FOR PARTS OF DORCHESTER AND BERKELEY COUNTIES NOW THAT ITS BEYOND 1 MARCH AND THE GROWING SEASON HAS BEGUN. HOWEVER...GIVEN THE TRANSIENT NATURE OF THE FREEZING LINE AND CONSIDERING A MUCH MORE SIGNIFICANT AND WIDESPREAD FREEZE WILL OCCUR FRIDAY NIGHT...A FREEZE WARNING WILL NOT BE ISSUED. FRIDAY...MODELS HAVE TRENDED DRIER IN THE LOW LEVELS AS COMPARED WITH RECENT RUNS. THUS...EVEN AS THE COLDEST AIR FEATURING TEMPS AROUND FREEZING AND WET BULB TEMPS JUST BELOW FREEZING SPREADS ACROSS INLAND AREAS BETWEEN THE EDISTO RIVER/INTERSTATE 26 AND THE SANTEE RIVER...LOW LEVEL MOISTURE NOW APPEARS BARELY SUFFICIENT TO SUPPORT ANYTHING MORE THAN DRIZZLE. THUS...THE PROBABILITY FOR ANY FREEZING PRECIPITATION HAS DIMINISHED...ALTHOUGH A SLIGHT CHANCE/CHANCE OF FREEZING DRIZZLE IS STILL JUSTIFIED ACROSS NORTHERN/INLAND LOCATIONS THROUGH MIDDAY FRIDAY...POSSIBLY A FAR SOUTH AS A WALTERBORO-NORTH CHARLESTON-MCCLELLANVILLE LINE. EVEN IF A BIT OF FREEZING DRIZZLE OCCURS ANY TRACE AMOUNTS OF GLAZE SHOULD ONLY OCCUR ON ELEVATED SURFACES SUCH AS TREES AND STREET SIGNS...GREATLY LIMITING ANY IMPACTS. FARTHER SOUTH/EAST WHERE DEEPER MOISTURE WILL RESIDE AND SLIGHT CHANCE/CHANCE POPS ARE JUSTIFIED THROUGH MIDDAY/EARLY AFTERNOON... TEMPERATURES WILL REMAIN ABOVE FREEZING. IN GENERAL...GUIDANCE HAS TRENDED TOWARD A SLOW BUT STEADY DRYING TREND...SO POPS DECREASE WITH TIME FRIDAY AFTERNOON AND FALL TO NEAR ZERO FRIDAY NIGHT. ASIDE FROM ANY PRECIP TYPE CONCERNS...FRIDAY WILL PROVIDE TEMPERATURES SOME 35-40F COLDER THAN THOSE OF THURSDAY...ONLY RECOVERING INTO THE UPPER 30S TO MID 40S. FRIDAY NIGHT...CONFIDENCE IS HIGH THAT SUB-FREEZING TEMPERATURES WILL OCCUR ACROSS MOST SOUTH CAROLINA LOCATIONS AND ACROSS SE GEORGIA LOCATIONS WEST OF I-95...AND A HARD FREEZE IS POSSIBLE WELL INLAND. PER COLLABORATION WITH WFO JAX...WILL DEFER DECISIONS REGARDING FREEZE WATCHES/WARNINGS TO SUBSEQUENT FORECAST PACKAGES. DESPITE SUNSHINE...TEMPERATURES WILL REMAIN BELOW NORMAL SATURDAY...RANGING FROM THE MID/UPPER 50S NORTH OF I-16 TO THE LOWER 60S SOUTH. SATURDAY NIGHT...TRANQUIL CONDITIONS WILL PREVAIL...AND LOW TEMPS WILL RANGE FROM THE LOWER/MID 30S WELL INLAND TO THE MID 40S ALONG THE GA COAST. SUNDAY...MID/HIGH LEVEL CLOUDS WILL INCREASE/THICKEN AHEAD OF A WAVE OF LOW PRESSURE APPROACHING FROM THE WEST. HOWEVER...NO RAIN IS EXPECTED DURING THE DAYLIGHT HOURS. ON THE POSITIVE SIDE... TEMPERATURES SHOULD RECOVER INTO THE 60S SUNDAY...CLOSER TO NORMAL FOR EARLY MARCH. LAKE WINDS...FAVORABLE MIXING PROFILES WILL DEVELOP THIS EVENING AND PERSIST THROUGH THE NIGHT AS COLD AIR INTENSIFIES. EXPECT NORTH WINDS OF 20 KT WITH FREQUENT GUSTS TO 25 KT TO PREVAIL THROUGH THE NIGHT...SO A LAKE WIND ADVISORY WILL BE ISSUED. GUSTY CONDITIONS WILL PERSIST THROUGH FRIDAY MORNING BEFORE DIMINISHING. WAVES ON THE OPEN LAKE WATERS WILL BUILD TO 1-2 FEET. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... BETWEEN A STATIONARY FRONT OFF THE SOUTHEAST COAST AND ACROSS THE FL PENINSULA AND HIGH PRESSURE CENTERED NORTH OF THE REGION...A BAROCLINIC ZONE WILL WAVER OVER THE REGION AND WILL CONTRIBUTE TO UNSETTLED CONDITIONS NEXT WEEK. WHILE A MOSTLY CLOUDY REGIME PUNCTUATED BY PERIODS OF PRECIPITATION AND FINALLY DEVOID OF ANY COLD AIR APPEARS LIKELY...CONFIDENCE REGARDING COMPLEX FORECAST DETAILS REMAINS LOW. FOR INSTANCE...WE MAINTAIN CHANCE POPS MONDAY AND TUESDAY...BUT SOME GUIDANCE SUGGESTS THAT LIKELY/CATEGORICAL POPS WILL EVENTUALLY BE NEEDED FOR THIS PERIOD. ALSO...THE POTENTIAL FOR THUNDERSTORMS COULD INCREASE...BUT THE UNCERTAIN DETAILS REGARDING INDIVIDUAL WAVES OF LOW PRESSURE AND AN ASSOCIATED UNCERTAIN POTENTIAL FOR AN INFLUX OF ANY SIGNIFICANT INSTABILITY DOES NOT JUSTIFY ANY MENTION OF THUNDER. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... VFR AT THE SITES THROUGH LATE AFTERNOON. CONDITIONS WILL CRASH RAPIDLY TO SUB-IFR BY 22-00Z AS A COLD FRONT PUSHES THROUGH. LIGHT TO MODERATE RAINS WILL AFFECT THE TERMINALS WITH THE FRONT WITH LOW CLOUDS/DRIZZLE TO FILLING IN BEHIND THE MAIN RAIN BAND HAS IT PUSHES OFFSHORE. LIFR CIGS ARE MOST LIKELY AT KCHS. GUSTY WINDS WILL AFFECT THE TERMINALS FOR THE NEXT 24 HOURS...BOTH IN THE WARM SECTOR AND IN THE POST-FRONTAL COLD SECTOR. EXTENDED AVIATION OUTLOOK...VFR LIKELY FRIDAY PM THROUGH THIS WEEKEND. FLIGHT RESTRICTIONS POSSIBLE IN RAIN EARLY NEXT WEEK. && .MARINE... TODAY...DENSE SEA FOG CONTINUES ACROSS THE NEAR SHORE WATERS LATE THIS MORNING AND WILL PERSIST INTO THE EARLY AFTERNOON. CONDITIONS HAVE IMPROVED SIGNIFICANTLY IN THE CHARLESTON HARBOR AND THE ADVISORY THERE HAS BEEN ALLOWED TO EXPIRE. THE MOST WIDESPREAD/DENSE SEA FOG WILL OCCUR OVER THE SOUTH CAROLINA NEARSHORE WATERS WHERE SOUTHWEST WINDS WILL PROVIDE LONGER PARCEL RESIDENCE TIMES OVER THE COLD SHELF WATERS. WILL EXTEND THE MARINE DENSE FOG ADVISORY THROUGH 2 PM...ALTHOUGH IT IS POSSIBLE THE GEORGIA NEARSHORE WATERS CAN BE REMOVED PRIOR TO THAT GIVEN THE LESS THAN IDEAL TRAJECTORY STRUCTURE THAT FAR SOUTH. OTHERWISE...SOUTH TO SOUTHWEST WINDS OF 15 KT OR LESS WILL PERSIST WITH SEAS 2-4 FT NEARSHORE WATERS AND 3-5 FT OVER THE CHARLESTON COUNTY AND GEORGIA OFFSHORE WATERS. TONIGHT...CONDITIONS WILL DETERIORATE RAPIDLY THIS EVENING AS A COLD FRONT PUSHES OFF THE COAST AND STRONG COLD AIR ADVECTION ENSUES. THE COMBINATION OF STRONG POST-FRONTAL COLD AIR ADVECTION AND STRONG ISALLOBARIC PRESSURES RISES WILL SUPPORT GALES FOR MUCH OF THE NIGHT OVER THE GEORGIA OFFSHORE WATERS AND THE CHARLESTON COUNTY WATERS WHERE FREQUENT GUSTS TO 35-40 KT GALES WILL OCCUR. THE HIGHEST WINDS WILL OCCUR OVER THE GEORGIA OFFSHORE WATERS...ROUGHLY BEYOND 40 NM...WHERE CONTRAFLOW ALONG THE WESTERN WALL OF THE GULF STREAM WILL BE AT ITS STRONGEST. THE GALE WATCH WILL BE UPGRADED TO A WARNING FOR THESE WATERS BEGINNING AT 6 PM AND CONTINUING THROUGH THE NIGHT. FOR THE OTHER NEARSHORE ZONES...INCLUDING THE CHARLESTON HARBOR...WINDS WILL REMAIN JUST BELOW GALE FORCE...SO SMALL CRAFT ADVISORIES WILL BE MAINTAINED. SEAS WILL BUILD TO 4-6 FT NEARSHORE WATERS AND 6-8 FT OFFSHORE WATERS. FRIDAY THROUGH MONDAY NIGHT...GALES WILL TRANSITION TO SMALL CRAFT ADVISORIES FRIDAY...AND ELEVATED N/NE WINDS AND ASSOCIATED SEAS WILL PERSIST INTO SATURDAY. A MORE TRANQUIL REGIME IS EXPECTED AS HIGH PRESSURE SHIFTS OVER THE WATERS SATURDAY NIGHT THROUGH SUNDAY. THEN...FORECAST CONFIDENCE DECREASES NEXT WEEK AS WINDS/SEAS WILL DEPEND ON A HIGHLY UNCERTAIN STORM TRACK. THE LATEST FORECAST HOLDS WINDS/SEAS WELL BELOW SCA LEVELS...BUT AN OFFSHORE TRACK FOLLOWED BY DEEPER AREAS OF LOW PRESSURE WILL TRANSLATE TO STRONGER WINDS AND HIGHER SEAS. && .CLIMATE... RECORD HIGHS FOR 5 MARCH... KCHS... 85/1997 KCXM... 84/1923 KSAV... 86/1955 RECORD LOW MAXIMUMS FOR 6 MARCH... KCHS... 43/1960 KCXM... 43/1960 KSAV... 42/1901 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...LAKE WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 2 PM EST FRIDAY FOR SCZ045. MARINE...DENSE FOG ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR AMZ350- 352-354. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 4 PM EST FRIDAY FOR AMZ352-354. GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EST FRIDAY FOR AMZ350. GALE WARNING FROM 6 PM THIS EVENING TO 2 PM EST FRIDAY FOR AMZ374. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 11 AM EST FRIDAY FOR AMZ330. && $$ NEAR TERM...BSH SHORT TERM...SPR LONG TERM...SPR AVIATION...SPR MARINE...SPR CLIMATE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
528 AM CST THU MAR 5 2015 .SHORT TERM... 356 AM CST TODAY THROUGH FRIDAY... HIGH PRESSURE WAS CENTERED TO OUR WEST OVER THE MID-MISSOURI VALLEY EARLY THIS MORNING...AND WILL SPREAD SOUTHEAST ACROSS CENTRAL ILLINOIS THIS AFTERNOON IN THE WAKE OF A POSITIVE-TILT UPPER TROUGH PROPAGATING ACROSS THE AREA THIS MORNING. ARCTIC AIR HAS OOZED INTO THE REGION OVER THE PAST 24 HOURS...THOUGH HIGH CLOUD COVER ASSOCIATED WITH THE UPPER JET STREAK AHEAD OF THE TROUGH AXIS HAS HELPED TO KEEP READINGS FROM BOTTOMING OUT TOO HARD OVERNIGHT. 3 AM SURFACE MAP SHOWS ONLY ROCHELLE AT -1...WITH TEMPERATURES OTHERWISE IN THE POSITIVE SINGLE DIGITS ACROSS THE FORECAST AREA OUTSIDE OF A FEW LOWER TEENS IN THE CORE OF THE CHICAGO URBAN HEAT ISLAND. MAY SEE A FEW MORE SUB-ZERO TEMPS THROUGH SUNRISE ESPECIALLY ACROSS NORTH CENTRAL ILLINOIS ALONG THE NORTHWEST PERIPHERY OF THE HIGH CLOUD COVER...WITH LIGHT NORTH WINDS PRODUCING WIND CHILLS FROM -5 TO -15 F. THE HIGH CLOUDS WILL SHIFT OFF TO THE EAST TODAY WITH THE UPPER TROUGH...WITH MAINLY SUNNY SKIES EXPECTED. ONLY SHALLOW MIXING IS ANTICIPATED WITH THE NORTHERN EXTENT OF THE SURFACE HIGH PASSING ACROSS THE AREA...THOUGH STRENGTHENING MARCH SUNSHINE SHOULD HELP CHILLY MORNING TEMPERATURES RECOVER INTO THE 15-20 DEGREE RANGE BY AFTERNOON. HAVE MAINTAINED FORECAST HIGHS A FEW DEGREES ABOVE THE WARMER END OF THE GUIDANCE SPECTRUM. THE HIGH WILL SHIFT SOUTHEAST OF THE AREA TONIGHT...ALLOWING SOUTHERLY WINDS TO DEVELOP AND WARM ADVECTION TO DEVELOP ALOFT. WINDS WILL BE LIGHT INITIALLY...WHICH COMBINED WITH MAINLY CLEAR SKIES SHOULD ALLOW TEMPS TO FALL QUICKLY THIS EVENING...THEN BECOME STEADY OR SLOWLY RISE A FEW DEGREES LATER IN THE NIGHT AS THOSE SOUTH WINDS INCREASE JUST A BIT. SOUTH WINDS WILL BECOME GUSTY FRIDAY AS A MID-LEVEL WAVE AND ASSOCIATED SURFACE LOW PRESSURE PASS NORTH OF THE LAKES ACROSS ONTARIO...NEARING 25 MPH AT TIMES DURING THE DAY. WHILE TEMPERATURES MODERATE INTO THE MID 20S TO AROUND 30 ON FRIDAY...THE GUSTY WINDS WILL KEEP WIND CHILLS IN THE TEENS THROUGH THE AFTERNOON MAKING FOR A RAW FEEL TO THE DAY. RATZER && .LONG TERM... 356 AM CST SATURDAY THROUGH WEDNESDAY... THE EASTERN NORTH AMERICAN UPPER TROUGH BROADENS AND DEAMPLIFIES DURING THE PERIOD...WHILE THE PERSISTENT STRONG WEST COAST UPPER RIDGE LOSES STRENGTH. THIS WILL PROVIDE MODERATING TEMPERATURES AS LOW LEVEL FLOW BECOMES MORE PERSISTENTLY WEST-SOUTHWEST...AND NORTHWEST FLOW ALOFT BECOMES MORE ZONAL ESPECIALLY INTO NEXT WEEK. INITIALLY...A COUPLE OF SMALL AMPLITUDE SHORT WAVES WILL RIPPLE SOUTHEAST ACROSS THE GREAT LAKES REGION OVER THE WEEKEND...ONE ON SATURDAY AND ANOTHER LATER IN THE DAY SUNDAY. WEAK SURFACE COLD FRONTS WILL GLANCE THE AREA WITH THESE TWO DISTURBANCES...TEMPERING THE WARM-UP JUST A BIT. STILL...WITH WARMING ALOFT AND SOUTH-SOUTHWEST FLOW AT THE SURFACE AHEAD OF EACH OF THESE WEAK FRONTS TEMPS SHOULD REACH THE 35-40 DEGREE RANGE BOTH SATURDAY AND SUNDAY. SOME OF THE ENSEMBLE GUIDANCE TRIES TO PAINT A LITTLE LIGHT PRECIPITATION AHEAD OF THESE BOUNDARIES AS WELL...THOUGH FORECAST TIME/HEIGHT SECTIONS AND SOUNDINGS SHOW A LACK OF DEEP MOISTURE AND IT APPEARS THAT THE THREAT OF ANY MORE SIGNIFICANT PRECIPITATION WILL REMAIN NORTH OF THE CWA. MORE ROBUST WARMING LOOMS JUST PAST THE WEEKEND AS UPPER FLOW BECOMES MORE ZONAL...AND ANOTHER DEEPER LOW MOVES EAST ACROSS CANADA. ECMWF WARMS OUR 850 MB TEMPS TO +2 C BY TUESDAY AND TO +6 C BY WEDNESDAY...WITH BOTH GFS/ECMWF GUIDANCE BOOSTING SFC TEMPS INTO THE LOW-MID 40S TO START THE WEEK...AND INTO THE 50-55 DEGREE RANGE TUESDAY AND WEDNESDAY. SURFACE HIGH PRESSURE RIDGE REMAINS TO OUR SOUTH FROM TEXAS TO SOUTHERN NEW ENGLAND DURING THE PERIOD... MINIMIZING THE RETURN OF DEEP MOISTURE AND KEEPING PRECIPITATION CHANCES LOW THROUGH THE EXTENDED. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * NONE. BMD //DISCUSSION...UPDATED 12Z... HIGH PRESSURE IS CENTERED OVER THE MID MISSOURI VALLEY EARLY THIS EVENING AND WILL MOVE TOWARDS THE OHIO VALLEY BY THIS EVENING. VFR CONDITIONS WILL BE IN PLACE WITH SOME MID/HIGH CLOUDS AND MODEST NORTHWEST WINDS WHICH WILL SLOWLY BACK TO THE SOUTHWEST BY THIS EVENING. GUSTY SOUTHWEST WINDS WILL DEVELOP ON THE BACKSIDE OF THE HIGH FRIDAY AHEAD OF AN APPROACHING COLD FRONT. BMD //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH. BMD //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT THROUGH WEDNESDAY...PRIMARILY VFR. BMD && .MARINE... 318 AM CST HIGH PRESSURE IS OVER THE UPPER MIDWEST EARLY THIS MORNING AND WILL DRIFT ACROSS THE OHIO VALLEY THIS EVENING...THEN SETTLE ACROSS THE SOUTHEASTERN STATES THROUGH THE WEEKEND. AS THE HIGH DRIFTS ACROSS THE MIDWEST...WINDS WILL BACK TO THE WEST THIS EVENING...THEN SOUTHWEST TONIGHT. A SERIES OF LOWS WILL MOVE ACROSS ONTARIO AND THE NORTHERN LAKES REGION THIS WEEKEND AND EARLY NEXT WEEK. WINDS WILL GENERALLY STAY OUT OF THE WEST AND SOUTHWEST THROUGH THIS PERIOD...FRESHENING UP AT TIMES IN ADVANCE OF THE LOWS. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 519 AM CST Thu Mar 5 2015 .SHORT TERM...(Today) ISSUED AT 254 AM CST THU MAR 5 2015 The storm system that brought snow to southeast Illinois yesterday and last evening was finally starting to shift away from our forecast area early this morning. At the surface, high pressure tracking southeast across northwest Iowa will drift across our area today bringing another 24 hours of unseasonably cold weather with afternoon highs struggling through the teens over most of the forecast area, which is about 30 degrees below where it should be for the first week in March. As the large fair weather system drifts closer to central Illinois today, the wind this afternoon will not be as gusty as what we saw yesterday. However, this morning, that will be a different story, as the pressure gradient will be tight enough for a few more hours to produce just enough wind to drop wind chills down to between -10 to -15 mainly north of I-74 for a few hours early this morning. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 254 AM CST THU MAR 5 2015 Pretty tranquil weather through the period, with no precipitation chances in the forecast into the middle of next week. Periodic upper waves will zip through the area in the northern jet stream, but moisture levels will be meager and little more than wind shifts are expected in our area. The longer range models are in general agreement with this pattern into mid week. The main highlight will be the welcome trend toward milder weather. The long wave trough from Lake Superior to New Mexico evident on early morning water vapor imagery will move through the Midwest later today. Lows in the single digits are still expected tonight, but the coldest temperatures will be this evening, with steady or rising temperatures overnight after surface high pressure settles into the Ohio Valley. However, wind chills well below zero are on tap, as low as 10 below in areas from Bloomington to Danville. After that, nice southwest flow should get much of the western half of the forecast area above freezing on Friday. Temperatures will continue to warm into next week, with most areas well into the 50s by Tuesday. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) ISSUED AT 515 AM CST THU MAR 5 2015 VFR conditions are expected to prevail through tonight. High pressure to our northwest will shift over the region today bringing a lighter wind flow and less in the way of cloud cover compared to yesterday. Currently have a band of cirrus streaming northeast across the area this morning but the latest HRRR forecasts indicate those should be to our east by mid-morning. Surface winds today will be from the northwest at 8 to 15 kts and then become light and variable by 00z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Smith
AREA FORECAST DISCUSSION
NWS JACKSON KY
948 AM EST THU MAR 5 2015 .UPDATE... ISSUED AT 947 AM EST THU MAR 5 2015 UPDATED FORECAST TO REFINE BETTER POPS AND SNOW COVERAGE TO THE MORNING HOURS. ALREADY SEEING THE BETTER RETURNS SHIFTING EAST...AND BACK EDGE OF SNOW PUSHING TOWARDS CENTRAL KENTUCKY. WINTER STORM WARNING WILL CONTINUE THROUGH 1 PM AS ADVERTISED...AND WILL LIKELY BE ALLOWED TO EXPIRE ON TIME AS THERE SHOULD ONLY BE SOME VERY LIGHT SNOW HANGING ON IN THE EAST FOR AN HOUR AFTER THAT. THUS...AN EXTENSION IS NOT LOOKING LIKELY AT THIS TIME. HOWEVER...WILL RE-EVALUATE AS NEEDED AS WE HEAD TOWARDS EARLY AFTERNOON. ALSO ADJUSTED SKY COVER INTO THE AFTERNOON AND EVENING AS IT LOOKS LIKE SOME PRETTY GOOD CLEARING EXPECTED AS VERY DRY AIR WORKS INTO THE REGION. THIS WILL YIELD CLEAR SKIES AND LIGHTER WINDS FOR TONIGHT...SETTING THE STAGE FOR A FRIGID NIGHT. WITH THE FRESH SNOW AND HIGH PRESSURE SETTING UP OVERHEAD...WE COULD EASILY FALL BELOW ZERO IN SEVERAL AREAS...LIKELY SETTING SOME RECORDS. FOR THIS REASON...WENT AHEAD AND ADJUSTED TEMPERATURES DOWN A BIT MORE TONIGHT WITH AREAS AS COLD AS -8 NOW...BUT WE COULD CERTAINLY GO LOWER THAN THAT. PLAN TO TAKE A CLOSER LOOK AT THIS WITH THE NEW MODEL GUIDANCE. UPDATE ISSUED AT 750 AM EST THU MAR 5 2015 WITH PRECIPITATION HAVING LONG CHANGED OVER TO SNOW AND OR SLEET ACROSS EASTERN KENTUCKY...AND WITH FLOODING OCCURRING ACROSS A LARGE OF PART OF THE AREA...THE FLOOD WATCH HAS BEEN CANCELLED. THE FORECAST WERE FRESHENED UP WITH THE LATEST OBS DATA...AND THE ZONE FORECAST TEXT PRODUCT WAS UPDATED TO REMOVE THE FLOOD WATCH HEADLINES. ASIDE FROM THAT NO MAJOR CHANGES WERE MADE TO THE FORECAST. THE WINTER STORM IS STILL IN FULL SWING ACROSS EASTERN KENTUCKY...WITH NUMEROUS ROUNDS OF SNOW AND SLEET STILL EXPECTED FOR THE AREA THROUGHOUT THE MORNING. THE HIGHEST SNOWFALL TOTALS SO FAR HAVE OCCURRED ALONG AND NORTH OF I64 AND BETWEEN THE MOUNTAIN PARKWAY AND I64 CORRIDOR. OUR FAR EASTERN COUNTIES HAVE BEEN EXPERIENCING QUITE A BIT OF SLEET SO FAR THIS MORNING WITH SNOW JUST NOW BEGINNING TO TAKE OVER. A NUMBER OF COUNTIES IN THE WARNING HAVE VERIFIED ALREADY AND IT APPEARS THAT WITH THE AMOUNT OF SNOW AND SLEET THAT ARE STILL MOVING ACROSS THE AREA...THAT IT WILL NOT BE LONG BEFORE MOST OR ALL OF OUR COUNTIES MEET WARNING CRITERIA FOR SLEET AND OR SNOW. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 514 AM EST THU MAR 5 2015 A MAJOR WINTER STORM CONTINUES TO AFFECT EASTERN KENTUCKY EARLY THIS MORNING. A LARGE AREA OF MODERATE SNOW IS CURRENTLY MOVING ACROSS PORTIONS OF EASTERN KENTUCKY GENERALLY EAST OF THE I75 CORRIDOR. ANOTHER BAND OF INTENSE SNOW IS ALSO REORGANIZING AND MOVING BACK INTO OUR FAR NORTHWESTERN COUNTIES. A QUICK CHECK OF UPSTREAM RADAR LOOPS CLEARLY SHOWS MORE BANDS AND AREAS OF MODERATE TO HEAVY SNOW MOVING INTO SOUTH CENTRAL KENTUCKY THAT WILL EVENTUALLY MAKE THEIR WAY INTO OUR AREA. EVEN THOUGH SNOW TOTALS ACROSS THE AREA HAVE NOT BEEN QUITE AS HIGH TO THIS POINT AS WE HAD PREVIOUSLY FORECAST...IT DOES APPEAR WE WILL HAVE PLENTY OF CHANCES THROUGHOUT THE MORNING TO PICK UP WARNING CRITERIA SNOW FALL FOR ALL OF THE AREA. THE ONE AREA WHERE THE SNOW HAS BEEN PILING UP QUICKLY IS NORTH OF THE MOUNTAIN PARKWAY. THE I64 CORRIDOR HAS SEEN A NUMBER OF LOCATIONS PICK UP 6 TO 8 INCHES OF SNOW SINCE YESTERDAY EVENING. AT THIS TIME IT APPEARS THAT MORE SNOW IS ON THE WAY...SO THERE COULD BE AREAS UP THERE THAT SEE AROUND A FOOT OF SNOW BEFORE THE EVENT COMES TO AND LATE THIS MORNING. THE FORECAST GRIDS WERE MODIFIED TO REFLECT THE HIGHER SNOW FALL AMOUNTS IN OUR FAR NORTH IN RELATION TO A NARROW BAND OF HEAVY SNOW THAT MOVED THROUGH THERE OVERNIGHT. THE NEW FORECAST WILL ALSO REFLECT HIGHER SNOW AMOUNTS IN THE CENTRAL AND EASTERN PORTIONS OF THE AREA PER THE LATEST HRRR MODEL OUTPUT. TEMPERATURES FOR TODAY WILL NOT RISE VERY MUCH DUE TO ALL THE SNOW...SO HIGHS WILL LIKELY ONLY TOP OUT 20S ACROSS THE AREA. THE SNOW SHOULD BEGIN WINDING DOWN BY MID MORNING...AND BE OUT OF EASTERN KENTUCKY BY MID AFTERNOON. FLOODING WILL ALSO CONTINUE TO BE AN ISSUE TODAY AND TOMORROW...AS AREA RIVERS HAVE BECOME SWOLLEN DUE TO HEAVY RAINFALL FROM THE PAST 24 HOURS AND RUNOFF FROM SNOW MELT. NUMEROUS FLOOD WARNINGS ARE CURRENTLY IN AFFECT ACROSS THE ENTIRE AREA. A NUMBER OF OUR RIVERS WILL CONTINUE TO RUN HIGH THROUGH THE DAY ON FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 545 AM EST THU MAR 5 2015 AFTER THE NEAR TERM SYSTEM DEPARTS...THE EASTERN CONUS TROUGH SHOULD BECOME MORE BROAD WITH TIME...WHILE THE WESTERN RIDGE REMAINS IN PLACE. THE MAIN BAND OF WESTERLIES WILL BE DISPLACED FURTHER NORTH WITH TIME...WITH DISTURBANCES IN NW FLOW LATE IN THE WEEK AND INTO THE WEEKEND GENERALLY PASSING NORTH. AT THE SFC...HIGH PRESSURE WILL SETTLE ACROSS THE SOUTHEASTERN STATES EARLY IN THE PERIOD...BEFORE DEPARTING LATE IN THE WEEKEND. BY THE END OF THE WEEKEND...RIDGING SHOULD BUILD OFF THE SOUTHEAST US COAST AND ALLOW DISTURBANCE MOVING OUT OF THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS TO MOVE ACROSS THE SOUTHEASTERN STATES AND APPALACHIANS. AFTER A COLD MORNING WITH SOME POSSIBLE SINGLE DIGITS IN SOME OF THE NORMAL COLD SPOTS WITH SNOW COVER EXPECTED FRIDAY NIGHT...THE PATTERN SHOULD BRING MODERATION IN TEMPERATURES TO CLOSER TO NORMAL BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK. THE DISTURBANCES PASSING TO OUR SOUTHEAST COULD BRING CHANCES FOR LIGHT PRECIPITATION AT TIMES FROM SUNDAY NIGHT THROUGH THE END OF THE PERIOD. IF PRECIP OCCURS DURING THAT PERIOD...MOST OF...IT NOT ALL THIS SHOULD FALL AS RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 709 AM EST THU MAR 5 2015 THE TAF SITES WILL CONTINUE TO EXPERIENCE WINTRY WEATHER THROUGH LATE THIS MORNING. CONDITIONS WILL VARY FROM MVFR WHEN THE SNOW IS NOT SO INTENSE TO LIFR CONDITIONS IN HEAVY SNOW DURING THE MOST INTENSE SNOW SHOWERS. THE SNOW SHOULD BE EXITING LOZ AND SME BY AROUND 20Z...JKL...SYM...AND SJS BY AROUND 22Z. BROKEN CIGS ARE THEN EXPECTED TO GIVE WAY TO SCATTERED CIGS AND VFR CONDITIONS BY 3Z TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...KAS SHORT TERM...AR LONG TERM...JP AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
750 AM EST THU MAR 5 2015 .UPDATE... ISSUED AT 750 AM EST THU MAR 5 2015 WITH PRECIPITATION HAVING LONG CHANGED OVER TO SNOW AND OR SLEET ACROSS EASTERN KENTUCKY...AND WITH FLOODING OCCURRING ACROSS A LARGE OF PART OF THE AREA...THE FLOOD WATCH HAS BEEN CANCELLED. THE FORECAST WERE FRESHENED UP WITH THE LATEST OBS DATA...AND THE ZONE FORECAST TEXT PRODUCT WAS UPDATED TO REMOVE THE FLOOD WATCH HEADLINES. ASIDE FROM THAT NO MAJOR CHANGES WERE MADE TO THE FORECAST. THE WINTER STORM IS STILL IN FULL SWING ACROSS EASTERN KENTUCKY...WITH NUMEROUS ROUNDS OF SNOW AND SLEET STILL EXPECTED FOR THE AREA THROUGHOUT THE MORNING. THE HIGHEST SNOWFALL TOTALS SO FAR HAVE OCCURRED ALONG AND NORTH OF I64 AND BETWEEN THE MOUNTAIN PARKWAY AND I64 CORRIDOR. OUR FAR EASTERN COUNTIES HAVE BEEN EXPERIENCING QUITE A BIT OF SLEET SO FAR THIS MORNING WITH SNOW JUST NOW BEGINNING TO TAKE OVER. A NUMBER OF COUNTIES IN THE WARNING HAVE VERIFIED ALREADY AND IT APPEARS THAT WITH THE AMOUNT OF SNOW AND SLEET THAT ARE STILL MOVING ACROSS THE AREA...THAT IT WILL NOT BE LONG BEFORE MOST OR ALL OF OUR COUNTIES MEET WARNING CRITERIA FOR SLEET AND OR SNOW. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 514 AM EST THU MAR 5 2015 A MAJOR WINTER STORM CONTINUES TO AFFECT EASTERN KENTUCKY EARLY THIS MORNING. A LARGE AREA OF MODERATE SNOW IS CURRENTLY MOVING ACROSS PORTIONS OF EASTERN KENTUCKY GENERALLY EAST OF THE I75 CORRIDOR. ANOTHER BAND OF INTENSE SNOW IS ALSO REORGANIZING AND MOVING BACK INTO OUR FAR NORTHWESTERN COUNTIES. A QUICK CHECK OF UPSTREAM RADAR LOOPS CLEARLY SHOWS MORE BANDS AND AREAS OF MODERATE TO HEAVY SNOW MOVING INTO SOUTH CENTRAL KENTUCKY THAT WILL EVENTUALLY MAKE THEIR WAY INTO OUR AREA. EVEN THOUGH SNOW TOTALS ACROSS THE AREA HAVE NOT BEEN QUITE AS HIGH TO THIS POINT AS WE HAD PREVIOUSLY FORECAST...IT DOES APPEAR WE WILL HAVE PLENTY OF CHANCES THROUGHOUT THE MORNING TO PICK UP WARNING CRITERIA SNOW FALL FOR ALL OF THE AREA. THE ONE AREA WHERE THE SNOW HAS BEEN PILING UP QUICKLY IS NORTH OF THE MOUNTAIN PARKWAY. THE I64 CORRIDOR HAS SEEN A NUMBER OF LOCATIONS PICK UP 6 TO 8 INCHES OF SNOW SINCE YESTERDAY EVENING. AT THIS TIME IT APPEARS THAT MORE SNOW IS ON THE WAY...SO THERE COULD BE AREAS UP THERE THAT SEE AROUND A FOOT OF SNOW BEFORE THE EVENT COMES TO AND LATE THIS MORNING. THE FORECAST GRIDS WERE MODIFIED TO REFLECT THE HIGHER SNOW FALL AMOUNTS IN OUR FAR NORTH IN RELATION TO A NARROW BAND OF HEAVY SNOW THAT MOVED THROUGH THERE OVERNIGHT. THE NEW FORECAST WILL ALSO REFLECT HIGHER SNOW AMOUNTS IN THE CENTRAL AND EASTERN PORTIONS OF THE AREA PER THE LATEST HRRR MODEL OUTPUT. TEMPERATURES FOR TODAY WILL NOT RISE VERY MUCH DUE TO ALL THE SNOW...SO HIGHS WILL LIKELY ONLY TOP OUT 20S ACROSS THE AREA. THE SNOW SHOULD BEGIN WINDING DOWN BY MID MORNING...AND BE OUT OF EASTERN KENTUCKY BY MID AFTERNOON. FLOODING WILL ALSO CONTINUE TO BE AN ISSUE TODAY AND TOMORROW...AS AREA RIVERS HAVE BECOME SWOLLEN DUE TO HEAVY RAINFALL FROM THE PAST 24 HOURS AND RUNOFF FROM SNOW MELT. NUMEROUS FLOOD WARNINGS ARE CURRENTLY IN AFFECT ACROSS THE ENTIRE AREA. A NUMBER OF OUR RIVERS WILL CONTINUE TO RUN HIGH THROUGH THE DAY ON FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 545 AM EST THU MAR 5 2015 AFTER THE NEAR TERM SYSTEM DEPARTS...THE EASTERN CONUS TROUGH SHOULD BECOME MORE BROAD WITH TIME...WHILE THE WESTERN RIDGE REMAINS IN PLACE. THE MAIN BAND OF WESTERLIES WILL BE DISPLACED FURTHER NORTH WITH TIME...WITH DISTURBANCES IN NW FLOW LATE IN THE WEEK AND INTO THE WEEKEND GENERALLY PASSING NORTH. AT THE SFC...HIGH PRESSURE WILL SETTLE ACROSS THE SOUTHEASTERN STATES EARLY IN THE PERIOD...BEFORE DEPARTING LATE IN THE WEEKEND. BY THE END OF THE WEEKEND...RIDGING SHOULD BUILD OFF THE SOUTHEAST US COAST AND ALLOW DISTURBANCE MOVING OUT OF THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS TO MOVE ACROSS THE SOUTHEASTERN STATES AND APPALACHIANS. AFTER A COLD MORNING WITH SOME POSSIBLE SINGLE DIGITS IN SOME OF THE NORMAL COLD SPOTS WITH SNOW COVER EXPECTED FRIDAY NIGHT...THE PATTERN SHOULD BRING MODERATION IN TEMPERATURES TO CLOSER TO NORMAL BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK. THE DISTURBANCES PASSING TO OUR SOUTHEAST COULD BRING CHANCES FOR LIGHT PRECIPITATION AT TIMES FROM SUNDAY NIGHT THROUGH THE END OF THE PERIOD. IF PRECIP OCCURS DURING THAT PERIOD...MOST OF...IT NOT ALL THIS SHOULD FALL AS RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 709 AM EST THU MAR 5 2015 THE TAF SITES WILL CONTINUE TO EXPERIENCE WINTRY WEATHER THROUGH LATE THIS MORNING. CONDITIONS WILL VARY FROM MVFR WHEN THE SNOW IS NOT SO INTENSE TO LIFR CONDITIONS IN HEAVY SNOW DURING THE MOST INTENSE SNOW SHOWERS. THE SNOW SHOULD BE EXITING LOZ AND SME BY AROUND 20Z...JKL...SYM...AND SJS BY AROUND 22Z. BROKEN CIGS ARE THEN EXPECTED TO GIVE WAY TO SCATTERED CIGS AND VFR CONDITIONS BY 3Z TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...AR SHORT TERM...AR LONG TERM...JP AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
709 AM EST THU MAR 5 2015 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 514 AM EST THU MAR 5 2015 A MAJOR WINTER STORM CONTINUES TO AFFECT EASTERN KENTUCKY EARLY THIS MORNING. A LARGE AREA OF MODERATE SNOW IS CURRENTLY MOVING ACROSS PORTIONS OF EASTERN KENTUCKY GENERALLY EAST OF THE I75 CORRIDOR. ANOTHER BAND OF INTENSE SNOW IS ALSO REORGANIZING AND MOVING BACK INTO OUR FAR NORTHWESTERN COUNTIES. A QUICK CHECK OF UPSTREAM RADAR LOOPS CLEARLY SHOWS MORE BANDS AND AREAS OF MODERATE TO HEAVY SNOW MOVING INTO SOUTH CENTRAL KENTUCKY THAT WILL EVENTUALLY MAKE THEIR WAY INTO OUR AREA. EVEN THOUGH SNOW TOTALS ACROSS THE AREA HAVE NOT BEEN QUITE AS HIGH TO THIS POINT AS WE HAD PREVIOUSLY FORECAST...IT DOES APPEAR WE WILL HAVE PLENTY OF CHANCES THROUGHOUT THE MORNING TO PICK UP WARNING CRITERIA SNOW FALL FOR ALL OF THE AREA. THE ONE AREA WHERE THE SNOW HAS BEEN PILING UP QUICKLY IS NORTH OF THE MOUNTAIN PARKWAY. THE I64 CORRIDOR HAS SEEN A NUMBER OF LOCATIONS PICK UP 6 TO 8 INCHES OF SNOW SINCE YESTERDAY EVENING. AT THIS TIME IT APPEARS THAT MORE SNOW IS ON THE WAY...SO THERE COULD BE AREAS UP THERE THAT SEE AROUND A FOOT OF SNOW BEFORE THE EVENT COMES TO AND LATE THIS MORNING. THE FORECAST GRIDS WERE MODIFIED TO REFLECT THE HIGHER SNOW FALL AMOUNTS IN OUR FAR NORTH IN RELATION TO A NARROW BAND OF HEAVY SNOW THAT MOVED THROUGH THERE OVERNIGHT. THE NEW FORECAST WILL ALSO REFLECT HIGHER SNOW AMOUNTS IN THE CENTRAL AND EASTERN PORTIONS OF THE AREA PER THE LATEST HRRR MODEL OUTPUT. TEMPERATURES FOR TODAY WILL NOT RISE VERY MUCH DUE TO ALL THE SNOW...SO HIGHS WILL LIKELY ONLY TOP OUT 20S ACROSS THE AREA. THE SNOW SHOULD BEGIN WINDING DOWN BY MID MORNING...AND BE OUT OF EASTERN KENTUCKY BY MID AFTERNOON. FLOODING WILL ALSO CONTINUE TO BE AN ISSUE TODAY AND TOMORROW...AS AREA RIVERS HAVE BECOME SWOLLEN DUE TO HEAVY RAINFALL FROM THE PAST 24 HOURS AND RUNOFF FROM SNOW MELT. NUMEROUS FLOOD WARNINGS ARE CURRENTLY IN AFFECT ACROSS THE ENTIRE AREA. A NUMBER OF OUR RIVERS WILL CONTINUE TO RUN HIGH THROUGH THE DAY ON FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 545 AM EST THU MAR 5 2015 AFTER THE NEAR TERM SYSTEM DEPARTS...THE EASTERN CONUS TROUGH SHOULD BECOME MORE BROAD WITH TIME...WHILE THE WESTERN RIDGE REMAINS IN PLACE. THE MAIN BAND OF WESTERLIES WILL BE DISPLACED FURTHER NORTH WITH TIME...WITH DISTURBANCES IN NW FLOW LATE IN THE WEEK AND INTO THE WEEKEND GENERALLY PASSING NORTH. AT THE SFC...HIGH PRESSURE WILL SETTLE ACROSS THE SOUTHEASTERN STATES EARLY IN THE PERIOD...BEFORE DEPARTING LATE IN THE WEEKEND. BY THE END OF THE WEEKEND...RIDGING SHOULD BUILD OFF THE SOUTHEAST US COAST AND ALLOW DISTURBANCE MOVING OUT OF THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS TO MOVE ACROSS THE SOUTHEASTERN STATES AND APPALACHIANS. AFTER A COLD MORNING WITH SOME POSSIBLE SINGLE DIGITS IN SOME OF THE NORMAL COLD SPOTS WITH SNOW COVER EXPECTED FRIDAY NIGHT...THE PATTERN SHOULD BRING MODERATION IN TEMPERATURES TO CLOSER TO NORMAL BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK. THE DISTURBANCES PASSING TO OUR SOUTHEAST COULD BRING CHANCES FOR LIGHT PRECIPITATION AT TIMES FROM SUNDAY NIGHT THROUGH THE END OF THE PERIOD. IF PRECIP OCCURS DURING THAT PERIOD...MOST OF...IT NOT ALL THIS SHOULD FALL AS RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 709 AM EST THU MAR 5 2015 THE TAF SITES WILL CONTINUE TO EXPERIENCE WINTRY WEATHER THROUGH LATE THIS MORNING. CONDITIONS WILL VARY FROM MVFR WHEN THE SNOW IS NOT SO INTENSE TO LIFR CONDITIONS IN HEAVY SNOW DURING THE MOST INTENSE SNOW SHOWERS. THE SNOW SHOULD BE EXITING LOZ AND SME BY AROUND 20Z...JKL...SYM...AND SJS BY AROUND 22Z. BROKEN CIGS ARE THEN EXPECTED TO GIVE WAY TO SCATTERED CIGS AND VFR CONDITIONS BY 3Z TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...AR LONG TERM...JP AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
621 AM EST THU MAR 5 2015 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 514 AM EST THU MAR 5 2015 A MAJOR WINTER STORM CONTINUES TO AFFECT EASTERN KENTUCKY EARLY THIS MORNING. A LARGE AREA OF MODERATE SNOW IS CURRENTLY MOVING ACROSS PORTIONS OF EASTERN KENTUCKY GENERALLY EAST OF THE I75 CORRIDOR. ANOTHER BAND OF INTENSE SNOW IS ALSO REORGANIZING AND MOVING BACK INTO OUR FAR NORTHWESTERN COUNTIES. A QUICK CHECK OF UPSTREAM RADAR LOOPS CLEARLY SHOWS MORE BANDS AND AREAS OF MODERATE TO HEAVY SNOW MOVING INTO SOUTH CENTRAL KENTUCKY THAT WILL EVENTUALLY MAKE THEIR WAY INTO OUR AREA. EVEN THOUGH SNOW TOTALS ACROSS THE AREA HAVE NOT BEEN QUITE AS HIGH TO THIS POINT AS WE HAD PREVIOUSLY FORECAST...IT DOES APPEAR WE WILL HAVE PLENTY OF CHANCES THROUGHOUT THE MORNING TO PICK UP WARNING CRITERIA SNOW FALL FOR ALL OF THE AREA. THE ONE AREA WHERE THE SNOW HAS BEEN PILING UP QUICKLY IS NORTH OF THE MOUNTAIN PARKWAY. THE I64 CORRIDOR HAS SEEN A NUMBER OF LOCATIONS PICK UP 6 TO 8 INCHES OF SNOW SINCE YESTERDAY EVENING. AT THIS TIME IT APPEARS THAT MORE SNOW IS ON THE WAY...SO THERE COULD BE AREAS UP THERE THAT SEE AROUND A FOOT OF SNOW BEFORE THE EVENT COMES TO AND LATE THIS MORNING. THE FORECAST GRIDS WERE MODIFIED TO REFLECT THE HIGHER SNOW FALL AMOUNTS IN OUR FAR NORTH IN RELATION TO A NARROW BAND OF HEAVY SNOW THAT MOVED THROUGH THERE OVERNIGHT. THE NEW FORECAST WILL ALSO REFLECT HIGHER SNOW AMOUNTS IN THE CENTRAL AND EASTERN PORTIONS OF THE AREA PER THE LATEST HRRR MODEL OUTPUT. TEMPERATURES FOR TODAY WILL NOT RISE VERY MUCH DUE TO ALL THE SNOW...SO HIGHS WILL LIKELY ONLY TOP OUT 20S ACROSS THE AREA. THE SNOW SHOULD BEGIN WINDING DOWN BY MID MORNING...AND BE OUT OF EASTERN KENTUCKY BY MID AFTERNOON. FLOODING WILL ALSO CONTINUE TO BE AN ISSUE TODAY AND TOMORROW...AS AREA RIVERS HAVE BECOME SWOLLEN DUE TO HEAVY RAINFALL FROM THE PAST 24 HOURS AND RUNOFF FROM SNOW MELT. NUMEROUS FLOOD WARNINGS ARE CURRENTLY IN AFFECT ACROSS THE ENTIRE AREA. A NUMBER OF OUR RIVERS WILL CONTINUE TO RUN HIGH THROUGH THE DAY ON FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 545 AM EST THU MAR 5 2015 AFTER THE NEAR TERM SYSTEM DEPARTS...THE EASTERN CONUS TROUGH SHOULD BECOME MORE BROAD WITH TIME...WHILE THE WESTERN RIDGE REMAINS IN PLACE. THE MAIN BAND OF WESTERLIES WILL BE DISPLACED FURTHER NORTH WITH TIME...WITH DISTURBANCES IN NW FLOW LATE IN THE WEEK AND INTO THE WEEKEND GENERALLY PASSING NORTH. AT THE SFC...HIGH PRESSURE WILL SETTLE ACROSS THE SOUTHEASTERN STATES EARLY IN THE PERIOD...BEFORE DEPARTING LATE IN THE WEEKEND. BY THE END OF THE WEEKEND...RIDGING SHOULD BUILD OFF THE SOUTHEAST US COAST AND ALLOW DISTURBANCE MOVING OUT OF THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS TO MOVE ACROSS THE SOUTHEASTERN STATES AND APPALACHIANS. AFTER A COLD MORNING WITH SOME POSSIBLE SINGLE DIGITS IN SOME OF THE NORMAL COLD SPOTS WITH SNOW COVER EXPECTED FRIDAY NIGHT...THE PATTERN SHOULD BRING MODERATION IN TEMPERATURES TO CLOSER TO NORMAL BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK. THE DISTURBANCES PASSING TO OUR SOUTHEAST COULD BRING CHANCES FOR LIGHT PRECIPITATION AT TIMES FROM SUNDAY NIGHT THROUGH THE END OF THE PERIOD. IF PRECIP OCCURS DURING THAT PERIOD...MOST OF...IT NOT ALL THIS SHOULD FALL AS RAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1237 AM EST THU MAR 5 2015 A COMPLEX WINTER STORM CONTINUES TO PUMMEL EASTERN KENTUCKY TONIGHT. MODERATE TO HEAVY SNOW CONTINUES TO FALL AT SYM AND WILL DO SO THROUGHOUT THE OVERNIGHT HOURS. THE SNOW WILL LIKELY NOT SLACK UP THERE UNTIL AROUND 15Z ON THURSDAY. JKL AND SME WERE EXPERIENCING A MESSY MIX OF RAIN...FREEZING RAIN...AND SLEET AT TAF ISSUANCE. LOZ SHOULD BE SEEING THE MIX OF PRECIP BETWEEN 6 AND 7Z. THE TRANSITION TO SNOW IS EXPECTED TO TAKE PLACE AT JKL BY 7 OR 8Z...WITH MODERATE TO HEAVY SNOW EXPECTED THROUGH MIDMORNING ON THURSDAY. LOZ AND SME ARE AT THE SOUTHERN END OF THE MAIN AREA OF SNOW...AND SHOULD NOT RECEIVE AS MUCH SNOW AS THE TAF SITES AT JKL...SYM...AND SJS...WHERE MUCH HIGHER TOTALS ARE EXPECTED. CONDITIONS AT THE TAF SITES WILL VARY GREATLY DURING THE NIGHT...AND WILL BE DEPENDENT ON THE INTENSITY OF THE SNOW. THE WORSE CASE SCENARIO WILL BE LIFR CONDITIONS IN THE HEAVIEST SNOW...WITH VSBYS WELL BELOW 1/4SM AT TIMES. TIMES WHEN THE SNOW IS NOT FALLING AS HEAVILY THE TAF SITES ARE EXPECTED TO HAVE MVFR TO IFR CONDITIONS. && .JKL WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH THIS EVENING FOR KYZ044-050>052-058>060-068- 069-079-080-083>088-104-106>120. WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...AR LONG TERM...JP AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
514 AM EST THU MAR 5 2015 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 514 AM EST THU MAR 5 2015 A MAJOR WINTER STORM CONTINUES TO AFFECT EASTERN KENTUCKY EARLY THIS MORNING. A LARGE AREA OF MODERATE SNOW IS CURRENTLY MOVING ACROSS PORTIONS OF EASTERN KENTUCKY GENERALLY EAST OF THE I75 CORRIDOR. ANOTHER BAND OF INTENSE SNOW IS ALSO REORGANIZING AND MOVING BACK INTO OUR FAR NORTHWESTERN COUNTIES. A QUICK CHECK OF UPSTREAM RADAR LOOPS CLEARLY SHOWS MORE BANDS AND AREAS OF MODERATE TO HEAVY SNOW MOVING INTO SOUTH CENTRAL KENTUCKY THAT WILL EVENTUALLY MAKE THEIR WAY INTO OUR AREA. EVEN THOUGH SNOW TOTALS ACROSS THE AREA HAVE NOT BEEN QUITE AS HIGH TO THIS POINT AS WE HAD PREVIOUSLY FORECAST...IT DOES APPEAR WE WILL HAVE PLENTY OF CHANCES THROUGHOUT THE MORNING TO PICK UP WARNING CRITERIA SNOW FALL FOR ALL OF THE AREA. THE ONE AREA WHERE THE SNOW HAS BEEN PILING UP QUICKLY IS NORTH OF THE MOUNTAIN PARKWAY. THE I64 CORRIDOR HAS SEEN A NUMBER OF LOCATIONS PICK UP 6 TO 8 INCHES OF SNOW SINCE YESTERDAY EVENING. AT THIS TIME IT APPEARS THAT MORE SNOW IS ON THE WAY...SO THERE COULD BE AREAS UP THERE THAT SEE AROUND A FOOT OF SNOW BEFORE THE EVENT COMES TO AND LATE THIS MORNING. THE FORECAST GRIDS WERE MODIFIED TO REFLECT THE HIGHER SNOW FALL AMOUNTS IN OUR FAR NORTH IN RELATION TO A NARROW BAND OF HEAVY SNOW THAT MOVED THROUGH THERE OVERNIGHT. THE NEW FORECAST WILL ALSO REFLECT HIGHER SNOW AMOUNTS IN THE CENTRAL AND EASTERN PORTIONS OF THE AREA PER THE LATEST HRRR MODEL OUTPUT. TEMPERATURES FOR TODAY WILL NOT RISE VERY MUCH DUE TO ALL THE SNOW...SO HIGHS WILL LIKELY ONLY TOP OUT 20S ACROSS THE AREA. THE SNOW SHOULD BEGIN WINDING DOWN BY MID MORNING...AND BE OUT OF EASTERN KENTUCKY BY MID AFTERNOON. FLOODING WILL ALSO CONTINUE TO BE AN ISSUE TODAY AND TOMORROW...AS AREA RIVERS HAVE BECOME SWOLLEN DUE TO HEAVY RAINFALL FROM THE PAST 24 HOURS AND RUNOFF FROM SNOW MELT. NUMEROUS FLOOD WARNINGS ARE CURRENTLY IN AFFECT ACROSS THE ENTIRE AREA. A NUMBER OF OUR RIVERS WILL CONTINUE TO RUN HIGH THROUGH THE DAY ON FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 514 AM EST THU MAR 5 2015 AN EXTENDED DISCUSSION WILL BE ISSUED SHORTLY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1237 AM EST THU MAR 5 2015 A COMPLEX WINTER STORM CONTINUES TO PUMMEL EASTERN KENTUCKY TONIGHT. MODERATE TO HEAVY SNOW CONTINUES TO FALL AT SYM AND WILL DO SO THROUGHOUT THE OVERNIGHT HOURS. THE SNOW WILL LIKELY NOT SLACK UP THERE UNTIL AROUND 15Z ON THURSDAY. JKL AND SME WERE EXPERIENCING A MESSY MIX OF RAIN...FREEZING RAIN...AND SLEET AT TAF ISSUANCE. LOZ SHOULD BE SEEING THE MIX OF PRECIP BETWEEN 6 AND 7Z. THE TRANSITION TO SNOW IS EXPECTED TO TAKE PLACE AT JKL BY 7 OR 8Z...WITH MODERATE TO HEAVY SNOW EXPECTED THROUGH MIDMORNING ON THURSDAY. LOZ AND SME ARE AT THE SOUTHERN END OF THE MAIN AREA OF SNOW...AND SHOULD NOT RECEIVE AS MUCH SNOW AS THE TAF SITES AT JKL...SYM...AND SJS...WHERE MUCH HIGHER TOTALS ARE EXPECTED. CONDITIONS AT THE TAF SITES WILL VARY GREATLY DURING THE NIGHT...AND WILL BE DEPENDENT ON THE INTENSITY OF THE SNOW. THE WORSE CASE SCENARIO WILL BE LIFR CONDITIONS IN THE HEAVIEST SNOW...WITH VSBYS WELL BELOW 1/4SM AT TIMES. TIMES WHEN THE SNOW IS NOT FALLING AS HEAVILY THE TAF SITES ARE EXPECTED TO HAVE MVFR TO IFR CONDITIONS. && .JKL WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH THIS EVENING FOR KYZ044-050>052-058>060-068- 069-079-080-083>088-104-106>120. WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR KYZ044- 050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...AR LONG TERM...JP AVIATION...AR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
522 AM CST THU MAR 5 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST THU MAR 5 2015 QUIET CONDITIONS REIGN ACROSS THE REGION EARLY THIS MORNING WITH MOSTLY CLEAR SKIES.THE CWA SITS IN BETWEEN UPPER LEVEL DISTURBANCES IN NORTHWESTERLY FLOW...ONE BEING THE TROUGH AXIS EXTENDING FROM ROUGHLY THE HUDSON BAY SOUTHWARD INTO THE SRN PLAINS...AND THE OTHER A WEAKER SHORTWAVE DISTURBANCE NOW WORKING ITS WAY INTO NERN MONTANA. AT THE SURFACE...HIGH PRESSURE REMAINS THE DOMINANT FEATURE...AND IS CURRENTLY CENTERED OVER ERN PORTION OF NEB/SD. WINDS ACROSS MUCH OF THE CWA REMAIN ON THE LIGHT/VARIABLE SIDE...AND TEMPS AS OF 3 AM RANGE FROM RIGHT AROUND THE 0 DEGREE MARK IN THE N/NE TO THE LOWER TEENS FURTHER SOUTH. THROUGH THE SHORT TERM PERIOD OF TODAY AND TONIGHT...WILL CONTINUE TO SEE NORTHWESTERLY FLOW SET UP IN THE UPPER LEVEL WITH THAT MAIN TROUGH AXIS PUSHING FURTHER EAST AND RIDGING IN PLACE OVER THE WEST COAST...AND WHILE MODELS SHOW THAT WEAK DISTURBANCE CURRENTLY OVER NERN MONTANA SLIDING THROUGH THE REGION LATER TODAY/THIS EVENING...THERE IS GOOD SUPPORT WITH KEEPING THE FORECAST DRY. AT THE SURFACE...THAT ARE OF HIGH PRESSURE CURRENTLY KEEPING OUR WINDS LIGHT WILL SLIDE OFF TO THE E/SE WITH TIME...WHILE A TROUGH OF LOW PRESSURE SETS UP ACROSS THE HIGH PLAINS. AS A RESULT THE WINDS WILL TURN MORE SRLY WITH TIME...A BIT MORE SWRLY ACROSS OUR FAR WRN COUNTIES. THOUGH THAT WEAK DISTURBANCE MOVING THROUGH LATER ON WONT BE BRINGING ANY PRECIPITATION TO THE CWA...IT WILL BE PUSHING A TROUGH AXIS THROUGH...TURNING WINDS MORE WESTERLY BY SUNRISE TOMORROW. MODELS ARE IN GOOD AGREEMENT SHOWING A MODERATING AIR MASS BUILDING INTO THE REGION FROM THE WEST...AND WITH THOSE MORE SRLY/EVENTUALLY WRLY WINDS...WILL BRING A WELCOME RISE IN TEMPERATURES BOTH TODAY AND TONIGHT. WENT CLOSER TO THE RAP FOR HIGHS TODAY...WHICH WAS A BUMP UP FOR MUCH OF THE AREA BUT NOT A HUGE CHANGE...WITH MID 30S IN THE EAST TO UPPER 40S IN THE WEST FOR FORECAST HIGHS TODAY. OVERNIGHT LOWS TONIGHT WILL BE MORE MILD COMPARED TO CURRENT TEMPS...WITH LOW/MID 20S IN THE FORECAST. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 353 AM CST THU MAR 5 2015 MUCH WARMER AIR WITH DRY CONDITIONS WILL BE THE BIG STORY LINE THIS WEEKEND INTO AT LEAST THE MIDDLE OF NEXT WEEK. WE WILL TRANSITION INTO MORE OF A SPLIT FLOW PATTERN WITH THE COLD ARCTIC AIR BOTTLED UP OVER CANADA...AND FAIRLY PROGRESSIVE FLOW OF PACIFIC ORIGIN ACROSS MUCH OF THE CONUS. MOST DAYS THE SFC WIND WILL HAVE SOMEWHAT OF A DOWNSLOPING WESTERLY COMPONENT AND AN ELEVATED MIXED LAYER OFF THE ROCKIES WILL KEEP TEMPERATURES ALOFT FAIRLY WARM. THIS ALL POINTS TO WARM SFC TEMPERATURES THAT WILL BE ABOVE NORMAL...TO EVEN WELL ABOVE NORMAL FOR THIS TIME OF YEAR...WHICH WILL BE A WELCOMED CHANGE AFTER OUR RECENT COLD SNAP. DESPITE NORMAL HIGHS ONLY BEING IN THE MID 40S...WE EXPECT TO SEE HIGHS THE NEXT FEW DAYS GENERALLY RANGING FROM THE MID 50S TO THE MID 60S. CONFIDENCE IS HIGH IN DRY WEATHER WITH GOOD MODEL AGREEMENT POINTING TOWARDS DRY CONDITIONS. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 518 AM CST THU MAR 5 2015 NO SIGNIFICANT CHANGES MADE FOR THIS TAF FORECAST...STILL EXPECTING QUIET WEATHER AND VFR CONDITIONS. EXPECTING MUCH OF THE DAYTIME HOURS TO BE MOSTLY CLEAR...WITH A FEW MORE MID/UPPER LEVEL CLOUDS POSSIBLE LATER THIS AFTERNOON WITH THE PASSAGE OF AN UPPER LEVEL SHORTWAVE DISTURBANCE. SURFACE HIGH PRESSURE IN PLACE CONTINUES TO KEEP WINDS EARLY THIS MORNING ON THE LIGHT/VARIABLE SIDE...BUT THROUGH THE DAYTIME HOURS WILL BECOME INCREASINGLY S/SWRLY AS THAT HIGH SLIDES OUT OF THE AREA AND A TROUGH OF LOW PRESSURE DEVELOPS OVER THE HIGH PLAINS. IN THE LATTER FEW HOURS OF THE TAF PERIOD...A FRONTAL BOUNDARY IS EXPECTED TO PUSH THROUGH THE AREA...BRINGING A SWITCH TO WRLY WINDS. WINDS THIS AFTERNOON LOOK TO TOP OUT AROUND 15 MPH. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...WESELY AVIATION...ADP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
700 AM EST THU MAR 5 2015 .SYNOPSIS... ARCTIC AIR WILL PUSH INTO THE REGION TODAY BEHIND A LOW PRESSURE SYSTEM THAT WAS CENTERED OVER NORTHWEST NORTH CAROLINA. THIS LOW WILL MOVE SOUTHEAST...FOLLOWED BY HIGH PRESSURE FOR TONIGHT AND FRIDAY. WINTER PRECIPITATION WILL BE WIDESPREAD BY THIS AFTERNOON ACROSS THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 425 AM EST THURSDAY... PRIMARY SURFACE LOW WAS OVER WILKESBORO AT 2AM WITH THE FRONT EXTENDING EAST ALONG THE SOUTHERN BORDER OF THE FORECAST AREA AND SOUTHWEST INTO LOUISIANA. MSAS ANALYSIS WAS NOT SHOWING MUCH PRESSURE FALLS BUT THERE WAS A SOUTHWARD PUSH OF THE COLD AIR INTO THE LOWER MISSISSIPPI VALLEY SINCE MIDNIGHT. AT 00Z THE 850MB FRONT WAS JUST NORTH OF THE FORECAST AREA. MODELS BRING THIS THROUGH THE COUNTY WARNING AREA BY 12Z/7AM...DROPPING TEMPERATURES TO -5 IN THE NORTHWEST. BY THE END OF THE DAY 850 MB TEMPERATURES WILL BE BELOW ZERO AS FAR SOUTH AS THE VIRGINIA / NORTH CAROLINA BORDER. TEMPERATURE PROFILES FROM THE MODELS SHOWED DIFFERENT TIMING OF HOW FAST THE WARM NOSE ERODES. LEANING TOWARD THE RAP AND NAM WHICH COOL THE WARM NOSE A LITTLE SLOWER THAN THE NAM. BIGGEST CHANGE WILL TO ADJUST THE TIMING AND SLOW DOWN THE CHANGE OVER TO MIXED WINTER PRECIPITATION AND THEN SNOW. EXTENDED IN TIME THE WINTER STORM WARNING FOR AMHERST AND BUCKINGHAM COUNTIES TO ACCOUNT FOR THE TIMING OF WHEN THE SNOW ENDS. ALSO ADDED A WINTER WEATHER ADVISORY FOR THE REMAINING COUNTIES IN NORTH CAROLINA. THE AMOUNT OF FREEZING RAIN HAS BEEN INCREASED FOR MUCH OF THE COUNTY WARNING AREA. AT THE SURFACE...RUC GUIDANCE HAD THE BEST HANDLE ON THE CURRENT TEMPERATURE TRENDS SO USED THIS AS A GUIDE FOR THE FALLING TEMPERATURES DURING THE DAY AND THEREFORE THE TRANSITION TIMES. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... AS OF 300 AM EST THURSDAY... DURING EARLY EVENING...PRECIPITATION WILL QUICKLY BE MAKING THE TRANSITION FROM SLEET TO SNOW ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT...JUST AHEAD OF THE BACK EDGE OF THE SNOW WHICH WILL BE RACING EAST ACROSS THE PIEDMONT. EXPECT WE WILL HAVE ALL MEASURABLE SNOWFALL OUT OF OUR AREA BY 10 PM...WITH DECREASING CLOUDS THEREAFTER. ARCTIC HIGH PRESSURE WILL THEN BUILD EAST UP THE OHIO RIVER VALLEY...MAKING FOR MOSTLY CLEAR SKIES AND LIGHT WINDS BY SUNRISE FRIDAY...IDEAL CONDITIONS FOR STRONG RADIATIONAL COOLING. THIS WILL RESULT IN ONE LAST SHOT OF FRIGID AIR FOR THE FORESEEABLE FUTURE AS WE START FRIDAY MORNING OFF WITH TEMPERATURES RANGING FROM NEAR ZERO ALONG THE INTERSTATE 64 CORRIDOR...TO THE LOW 20S ACROSS THE FOOTHILLS AND PIEDMONT OF NORTH CAROLINA. THE ARCTIC AIRMASS WILL KEEP FRIDAY AFTERNOON TEMPERATURES WELL BELOW NORMAL...WITH HIGHS RANGING FROM THE UPPER 20S NORTH TO AROUND 40 SOUTH. TEMPERATURES WILL BEGIN TO MODERATE FOR FRIDAY NIGHT AND SATURDAY AS WINDS SHIFT MORE WEST SOUTHWESTERLY AHEAD OF AN APPROACHING WEAK COLD FRONT...CAUSING THE COLDER AIR TO RETREAT BACK TO THE NORTH. WILL START SATURDAY OFF WITH LOWS IN THE UPPER TEENS AND LOW 20S FOR MUCH OF THE REGION...WITH ABUNDANT SUNSHINE HELPING AFTERNOON HIGHS WARM INTO THE 40S ACROSS THE MOUNTAINS AND THE LOW TO MID 50S EAST OF THE BLUE RIDGE. THE WARMUP WILL CONTINUE INTO SUNDAY...ALBEIT WITH INCREASING CLOUDS BUT OTHERWISE DRY CONDITIONS. AFTERNOON HIGHS WILL RANGE FROM THE MID/UPPER 40S WEST TO THE MID/UPPER 50S EAST. WILL BE KEEPING AN EYE ON AN UPPER LEVEL DISTURBANCE PASSING ACROSS THE SOUTHEAST STATES SUNDAY NIGHT...WHICH HAS THE POTENTIAL OF BRINGING LIGHT RAIN EARLY IN THE NIGHT...CHANGING OVER TO A LIGHT WINTRY MIX TOWARD SUNRISE MONDAY. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM EST WEDNESDAY... THERE HAS BEEN CONSIDERABLE VARIATION IN THE MODEL GUIDANCE DURING THE SUNDAY NIGHT THROUGH TUESDAY TIME PERIOD. WHILE EACH IS FAIRLY CONSISTENT THAT A LONG WAVE TROUGH WILL DEVELOP ACROSS THE EASTERN THIRD OF CONUS...THERE HAVE BEEN INCONSISTENCIES AS TO WHETHER OR NOT...AND WHEN...AND WHAT TRACK A SOUTHERN STREAM SYSTEM MAY GET PICKED UP ON THE EAST SIDE OF THIS TROUGH AND PROGRESS NORTHEAST ACROSS OUR AREA. THE GFS HAS NOT BEEN FAVORABLE OF THIS OCCURRENCE. THE ECMWF WAS OPTIMISTIC ON AN ARRIVAL A SOUTHERN SYSTEM ON MONDAY. OUR FORECAST TODAY WILL REFLECT TEMPERATURES CONTINUING TO MODERATE THROUGH MONDAY...WITH THE THINKING THAT THE DEVELOPING TROUGH AXIS WILL REMAIN TO OUR WEST...AND WE WILL CONTINUE IN WARM AIR ADVECTION AT THE SURFACE. IT WILL ALSO REFLECT THE POTENTIAL FOR SOME ISOLATED TO SCATTERED UPSLOPE SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA WHERE 850 MB FLOW WILL BE MORE W-NW. IT WILL ALSO ALLOW FOR A SLIGHT CHANCE OF A SOUTHERN STREAM SYSTEM IMPACTING THE AREA ON TUESDAY WITH RAIN OR FREEZING RAIN. THE LATEST GUIDANCE FOR THE EARLY TO MIDDLE PART OF NEXT WEEK CONTINUES TO FLUCTUATES IN REGARDS TO THE TIMING AND TRACK OF A SOUTHERN STREAM SYSTEM. THE LATEST TRENDS BRING THE GFS INTO PLAY NOW FOR BRINGING A SYSTEM THROUGH THE AREA ON WEDNESDAY...THE CANADIAN AND ECWMF STILL A LITTLE EARLIER. IN ADDITION TO THE SMALL CHANCE OF PRECIPITATION ON TUESDAY...WE WILL ALSO ADD WEDNESDAY INTO THE MIX TO REFLECT THE MODEL VARIATIONS AND A SMALL POTENTIAL EACH DAY FOR A LOW AND ITS ASSOCIATED PRECIPITATION TO PROGRESS OVER OR NEAR THE REGION. WHILE MOST OF THE REGION SHOULD EXPERIENCE RAIN ON WEDNESDAY...A FEW SPOTS IN THE SOUTHEAST WEST VIRGINIA MAY BE COLD ENOUGH FOR A BRIEF PERIOD OF FREEZING RAIN. HIGH TEMPERATURES ON WEDNESDAY WILL BE MILDER THAN THOSE OF TUESDAY. EXPECT A RANGE OF LOW TO MID 50S ACROSS THE MOUNTAINS WITH UPPER 50S TO LOWER 60S ACROSS THE PIEDMONT. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 655 AM EST THURSDAY... LOW PRESSURE OVER NORTH CAROLINA WILL DRAW COLD AIR INTO THE REGION CHANGING RAIN TO FREEZING RAIN AND SLEET...THEN SNOW. CEILINGS WILL LOWER TO IFR IF NOT ALREADY THERE. VISIBILITIES WILL REMAIN IFR THROUGH 22Z/5PM AT MOST SITES. LOW CONFIDENCE AS TOO WHEN FZRA AND PL WILL START AT LOCAL AIRPORTS. AT THIS TIME USING CURRENT OBSERVATIONS TRENDS AND NAM TEMPERATURE PROFILES HAVE KROA/KBLF/KLWB AND KBCB CHANGING TO FZRA/PL/SN BY NOON AND AT KLYH/KDAN BEFORE 4PM. SNOW WILL BE ENDING AROUND 00Z/7PM AT ALL SITES. CEILINGS WILL REMAIN MVFR IN THE MOUNTAINS BUT MODERATE CONFIDENCE THAT CLOUDS WILL LIFT TO VFR EAST OF THE BLUE RIDGE BEFORE MIDNIGHT. EXTENDED FORECAST... FRIDAY TO SUNDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. SOME RAIN AND SNOW SHOWERS ARE POSSIBLE ON MONDAY IN THE WESTERN MOUNTAINS WITH BRIEF MVFR EXPECTED. && .HYDROLOGY... AS OF 330 AM EST THURSDAY FLOODING WAS WIDESPREAD ACROSS MERCER AND TAZEWELL COUNTIES OVERNIGHT. RAINFALL ACROSS THE AREA WEDNESDAY RANGED FROM ONE /1.00/ TO ONE AND A HALF /1.50/ INCHES. THE RAINFALL...COMBINED WITH EXISTING SNOWMELT...CAUSING EXTENSIVE LOWLAND FLOODING. IN TERMS OF THE RIVERS...THE BLUESTONE AND CLINCH HAVE BEEN THE MOST AFFECTED. MODERATE FLOOD LEVELS WERE REACHED AT SPANISHBURG AND PIPESTEM...WITH MINOR FLOODING AT RICHLANDS. THESE LOCATIONS MAY CONTINUE TO EXPERIENCE FLOODING TODAY. FOR TODAY...THE BIG QUESTION IS HOW MUCH MORE LIQUID PRECIPITATION OCCURS BEFORE THE TRANSITION TO FROZEN. CURRENT THINKING IS THAT ALL PRECIPITATION ACROSS WEST VIRGINIA...AND ALL THE BORDERING COUNTIES WITH VIRGINIA...WILL TRANSITION OVER TO SNOW AFTER DAYBREAK THIS MORNING. THIS SHOULD SIGNIFICANTLY STABILIZE THE HYDROLOGIC SITUATION...LIMITING FURTHER RUNOFF AND ALLOWING RIVERS AND SMALL STREAMS TO RECEDE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ007- 009>018-022-034. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ019- 020-023-024. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ032-033-043>046-058-059. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ035- 047. NC...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ001- 002-018. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NCZ003-019. WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EST THIS EVENING FOR NCZ004>006-020. WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ042>044-507-508. && $$ SYNOPSIS...AMS NEAR TERM...AMS/WP SHORT TERM...NF LONG TERM...DS AVIATION...AMS HYDROLOGY...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
512 AM EST THU MAR 5 2015 .SYNOPSIS... ARCTIC AIR WILL PUSH INTO THE REGION TODAY BEHIND A LOW PRESSURE SYSTEM THAT WAS CENTERED OVER NORTHWEST NORTH CAROLINA. THIS LOW WILL MOVE SOUTHEAST...FOLLOWED BY HIGH PRESSURE FOR TONIGHT AND FRIDAY. WINTER PRECIPITATION WILL BE WIDESPREAD BY THIS AFTERNOON ACROSS THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 425 AM EST THURSDAY... PRIMARY SURFACE LOW WAS OVER WILKESBORO AT 2AM WITH THE FRONT EXTENDING EAST ALONG THE SOUTHERN BORDER OF THE FORECAST AREA AND SOUTHWEST INTO LOUISIANA. MSAS ANALYSIS WAS NOT SHOWING MUCH PRESSURE FALLS BUT THERE WAS A SOUTHWARD PUSH OF THE COLD AIR INTO THE LOWER MISSISSIPPI VALLEY SINCE MIDNIGHT. AT 00Z THE 850MB FRONT WAS JUST NORTH OF THE FORECAST AREA. MODELS BRING THIS THROUGH THE COUNTY WARNING AREA BY 12Z/7AM...DROPPING TEMPERATURES TO -5 IN THE NORTHWEST. BY THE END OF THE DAY 850 MB TEMPERATURES WILL BE BELOW ZERO AS FAR SOUTH AS THE VIRGINIA / NORTH CAROLINA BORDER. TEMPERATURE PROFILES FROM THE MODELS SHOWED DIFFERENT TIMING OF HOW FAST THE WARM NOSE ERODES. LEANING TOWARD THE RAP AND NAM WHICH COOL THE WARM NOSE A LITTLE SLOWER THAN THE NAM. BIGGEST CHANGE WILL TO ADJUST THE TIMING AND SLOW DOWN THE CHANGE OVER TO MIXED WINTER PRECIPITATION AND THEN SNOW. EXTENDED IN TIME THE WINTER STORM WARNING FOR AMHERST AND BUCKINGHAM COUNTIES TO ACCOUNT FOR THE TIMING OF WHEN THE SNOW ENDS. ALSO ADDED A WINTER WEATHER ADVISORY FOR THE REMAINING COUNTIES IN NORTH CAROLINA. THE AMOUNT OF FREEZING RAIN HAS BEEN INCREASED FOR MUCH OF THE COUNTY WARNING AREA. AT THE SURFACE...RUC GUIDANCE HAD THE BEST HANDLE ON THE CURRENT TEMPERATURE TRENDS SO USED THIS AS A GUIDE FOR THE FALLING TEMPERATURES DURING THE DAY AND THEREFORE THE TRANSITION TIMES. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... AS OF 300 AM EST THURSDAY... DURING EARLY EVENING...PRECIPITATION WILL QUICKLY BE MAKING THE TRANSITION FROM SLEET TO SNOW ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT...JUST AHEAD OF THE BACK EDGE OF THE SNOW WHICH WILL BE RACING EAST ACROSS THE PIEDMONT. EXPECT WE WILL HAVE ALL MEASURABLE SNOWFALL OUT OF OUR AREA BY 10 PM...WITH DECREASING CLOUDS THEREAFTER. ARCTIC HIGH PRESSURE WILL THEN BUILD EAST UP THE OHIO RIVER VALLEY...MAKING FOR MOSTLY CLEAR SKIES AND LIGHT WINDS BY SUNRISE FRIDAY...IDEAL CONDITIONS FOR STRONG RADIATIONAL COOLING. THIS WILL RESULT IN ONE LAST SHOT OF FRIGID AIR FOR THE FORESEEABLE FUTURE AS WE START FRIDAY MORNING OFF WITH TEMPERATURES RANGING FROM NEAR ZERO ALONG THE INTERSTATE 64 CORRIDOR...TO THE LOW 20S ACROSS THE FOOTHILLS AND PIEDMONT OF NORTH CAROLINA. THE ARCTIC AIRMASS WILL KEEP FRIDAY AFTERNOON TEMPERATURES WELL BELOW NORMAL...WITH HIGHS RANGING FROM THE UPPER 20S NORTH TO AROUND 40 SOUTH. TEMPERATURES WILL BEGIN TO MODERATE FOR FRIDAY NIGHT AND SATURDAY AS WINDS SHIFT MORE WEST SOUTHWESTERLY AHEAD OF AN APPROACHING WEAK COLD FRONT...CAUSING THE COLDER AIR TO RETREAT BACK TO THE NORTH. WILL START SATURDAY OFF WITH LOWS IN THE UPPER TEENS AND LOW 20S FOR MUCH OF THE REGION...WITH ABUNDANT SUNSHINE HELPING AFTERNOON HIGHS WARM INTO THE 40S ACROSS THE MOUNTAINS AND THE LOW TO MID 50S EAST OF THE BLUE RIDGE. THE WARMUP WILL CONTINUE INTO SUNDAY...ALBEIT WITH INCREASING CLOUDS BUT OTHERWISE DRY CONDITIONS. AFTERNOON HIGHS WILL RANGE FROM THE MID/UPPER 40S WEST TO THE MID/UPPER 50S EAST. WILL BE KEEPING AN EYE ON AN UPPER LEVEL DISTURBANCE PASSING ACROSS THE SOUTHEAST STATES SUNDAY NIGHT...WHICH HAS THE POTENTIAL OF BRINGING LIGHT RAIN EARLY IN THE NIGHT...CHANGING OVER TO A LIGHT WINTRY MIX TOWARD SUNRISE MONDAY. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM EST WEDNESDAY... THERE HAS BEEN CONSIDERABLE VARIATION IN THE MODEL GUIDANCE DURING THE SUNDAY NIGHT THROUGH TUESDAY TIME PERIOD. WHILE EACH IS FAIRLY CONSISTENT THAT A LONG WAVE TROUGH WILL DEVELOP ACROSS THE EASTERN THIRD OF CONUS...THERE HAVE BEEN INCONSISTENCIES AS TO WHETHER OR NOT...AND WHEN...AND WHAT TRACK A SOUTHERN STREAM SYSTEM MAY GET PICKED UP ON THE EAST SIDE OF THIS TROUGH AND PROGRESS NORTHEAST ACROSS OUR AREA. THE GFS HAS NOT BEEN FAVORABLE OF THIS OCCURRENCE. THE ECMWF WAS OPTIMISTIC ON AN ARRIVAL A SOUTHERN SYSTEM ON MONDAY. OUR FORECAST TODAY WILL REFLECT TEMPERATURES CONTINUING TO MODERATE THROUGH MONDAY...WITH THE THINKING THAT THE DEVELOPING TROUGH AXIS WILL REMAIN TO OUR WEST...AND WE WILL CONTINUE IN WARM AIR ADVECTION AT THE SURFACE. IT WILL ALSO REFLECT THE POTENTIAL FOR SOME ISOLATED TO SCATTERED UPSLOPE SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA WHERE 850 MB FLOW WILL BE MORE W-NW. IT WILL ALSO ALLOW FOR A SLIGHT CHANCE OF A SOUTHERN STREAM SYSTEM IMPACTING THE AREA ON TUESDAY WITH RAIN OR FREEZING RAIN. THE LATEST GUIDANCE FOR THE EARLY TO MIDDLE PART OF NEXT WEEK CONTINUES TO FLUCTUATES IN REGARDS TO THE TIMING AND TRACK OF A SOUTHERN STREAM SYSTEM. THE LATEST TRENDS BRING THE GFS INTO PLAY NOW FOR BRINGING A SYSTEM THROUGH THE AREA ON WEDNESDAY...THE CANADIAN AND ECWMF STILL A LITTLE EARLIER. IN ADDITION TO THE SMALL CHANCE OF PRECIPITATION ON TUESDAY...WE WILL ALSO ADD WEDNESDAY INTO THE MIX TO REFLECT THE MODEL VARIATIONS AND A SMALL POTENTIAL EACH DAY FOR A LOW AND ITS ASSOCIATED PRECIPITATION TO PROGRESS OVER OR NEAR THE REGION. WHILE MOST OF THE REGION SHOULD EXPERIENCE RAIN ON WEDNESDAY...A FEW SPOTS IN THE SOUTHEAST WEST VIRGINIA MAY BE COLD ENOUGH FOR A BRIEF PERIOD OF FREEZING RAIN. HIGH TEMPERATURES ON WEDNESDAY WILL BE MILDER THAN THOSE OF TUESDAY. EXPECT A RANGE OF LOW TO MID 50S ACROSS THE MOUNTAINS WITH UPPER 50S TO LOWER 60S ACROSS THE PIEDMONT. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... AS OF 1125 PM EST WEDNESDAY... FLYING CONDITIONS WILL CONTINUE TO DETERIORATE OVER THE MOUNTAINS OVERNIGHT AND IN THE EAST BY DAYBREAK THURSDAY. THIS WILL RESULT IN WIDESPREAD MVFR TO IFR CIGS OVER THE MOUNTAIN LOCATIONS WITH PERIODIC MVFR VSBYS AND PERHAPS IFR AT TIMES AT KBLF/KLWB. BRIEF MVFR MAY OCCUR AT KROA AND POINTS EAST OVER THE NEXT FEW HOURS BEFORE TRENDING TO OVERALL MVFR OVERNIGHT. WINDS WILL SHIFT NW-N BEHIND THE FRONT. THE PRECIPITATION WILL GRADUALLY TRANSITION FROM RAIN TO A RAIN/SLEET MIX...TO A SNOW/SLEET MIX TO MAINLY ALL SNOW BEFORE ENDING OUT EAST THURSDAY AFTERNOON. THIS TRANSITION WILL START FIRST AROUND 06Z/1AM AROUND KBLF...AND THE LAST LOCATION TO TRANSITION TO ALL SNOW WILL BE KDAN AROUND 22Z/5PM. BY LATE IN THE AFTERNOON THURSDAY...CIGS/VSBYS WILL START TO IMPROVE IN THE WEST. A CLEARING TREND IS EXPECTED THURSDAY EVENING...ESPECIALLY IN THE EAST WITH VFR TO MVFR CIGS LIKELY LINGERING IN THE WEST THURSDAY EVENING. MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE TAF PERIOD. EXTENDED FORECAST... FRIDAY TO SUNDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. SOME RAIN AND SNOW SHOWERS ARE POSSIBLE ON MONDAY IN THE WESTERN MOUNTAINS WITH BRIEF MVFR EXPECTED. && .HYDROLOGY... AS OF 330 AM EST THURSDAY FLOODING WAS WIDESPREAD ACROSS MERCER AND TAZEWELL COUNTIES OVERNIGHT. RAINFALL ACROSS THE AREA WEDNESDAY RANGED FROM ONE /1.00/ TO ONE AND A HALF /1.50/ INCHES. THE RAINFALL...COMBINED WITH EXISTING SNOWMELT...CAUSING EXTENSIVE LOWLAND FLOODING. IN TERMS OF THE RIVERS...THE BLUESTONE AND CLINCH HAVE BEEN THE MOST AFFECTED. MODERATE FLOOD LEVELS WERE REACHED AT SPANISHBURG AND PIPESTEM...WITH MINOR FLOODING AT RICHLANDS. THESE LOCATIONS MAY CONTINUE TO EXPERIENCE FLOODING TODAY. FOR TODAY...THE BIG QUESTION IS HOW MUCH MORE LIQUID PRECIPITATION OCCURS BEFORE THE TRANSITION TO FROZEN. CURRENT THINKING IS THAT ALL PRECIPITATION ACROSS WEST VIRGINIA...AND ALL THE BORDERING COUNTIES WITH VIRGINIA...WILL TRANSITION OVER TO SNOW AFTER DAYBREAK THIS MORNING. THIS SHOULD SIGNIFICANTLY STABILIZE THE HYDROLOGIC SITUATION...LIMITING FURTHER RUNOFF AND ALLOWING RIVERS AND SMALL STREAMS TO RECEDE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ007- 009>018-022-034. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ019- 020-023-024. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ032-033-043>046-058-059. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ035- 047. NC...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ001- 002-018. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NCZ003-019. WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EST THIS EVENING FOR NCZ004>006-020. WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ042>044-507-508. && $$ SYNOPSIS...AMS NEAR TERM...AMS/WP SHORT TERM...NF LONG TERM...DS AVIATION...AMS/DS/JH/KK HYDROLOGY...PM
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
932 AM CST THU MAR 5 2015 .UPDATE... A 1004 MB AREA OF HIGH PRESSURE SITUATED OVER THE UPPER MIDWEST WILL BE IN CONTROL OVER THE REGION TODAY. CONDITIONS WILL REMAIN QUIET BUT CHILLY THROUGH THE AFTN HOURS...WITH HIGHS REACHING INTO THE MID TEENS. STEEPENING LOW LEVEL LAPSE RATES COULD HELP SUPPORT SOME LOW CLOUDS THIS AFTN...BUT A MOSTLY DRY ATMOSPHERE WILL KEEP CLOUD COVER FROM BECOMING TOO EXTENSIVE. && .AVIATION/18Z TAFS/... VFR CONDITIONS SHOULD PERSIST INTO THE AFTN HOURS TODAY AS AN AREA OF HIGH PRESSURE WILL BE IN CONTROL OVER THE REGION TODAY. VSBYS WILL STAY IN VFR CATEGORIES DUE TO A MOSTLY DRY ATMOSPHERE. THE ONLY CONCERN WILL BE SOME MVFR CIGS FROM LOW CLOUDS DUE TO STEEPENING LOW LEVEL LAPSE RATES. NAM AND RAP BUFKIT SOUNDINGS SHOW DRY ADIABATIC LOW LEVEL LAPSE RATES UP TO JUST BELOW 900MB...OR JUST BELOW 3000FT THIS AFTN. WINDS SHOULD BE FAIRLY WEAK THIS AFTN AS WELL WITH GUSTS REACHING ONLY THE LOWER TEENS...WITH WINDS TURNING FROM THE NORTHWEST EARLY THIS AFTN TO THE SOUTHWEST BY THE EVENING HOURS. && .PREV DISCUSSION... /ISSUED 156 AM CST THU MAR 5 2015/ TODAY AND TONIGHT... FORECAST CONFIDENCE HIGH. A STRONG 185 KNOT 250 MB JET MAX FROM THE MID MISSISSIPPI VALLEY TO THE EASTERN GREAT LAKES WILL MOVE OFF TO THE EAST AS AN UPPER TROUGH MOVES INTO WISCONSIN THIS MORNING. THIS PLACES THE LEFT ENTRANCE REGION OF THE JET OVER THE AREA THIS MORNING AS THE WEAK UPPER DIVERGENCE BECOMES CONVERGENT. 700 MB DOWNWARD MOTION BECOMES STRONGER BEFORE BECOMING WEAK UPWARD AS A SECOND WEAKER TROUGH MOVES INTO SOUTHERN WISCONSIN LATE TONIGHT. THE 850/700 MB LAYERS REMAINS DRY...UNTIL MOISTURE BEGINS TO INCREASE TOWARD SUNRISE FRIDAY WEST OF MADISON. SHALLOW HIGHER 925 MB MOISTURE...IS JUST ENOUGH FOR THE POTENTIAL OF A FEW AFTERNOON FAIR WEATHER CUMULUS CLOUDS. WEAK 925/850/700 MB WARM AIR ADVECTION BEGINS TODAY AND INCREASES TONIGHT. EXPECT SUB ZERO TEMPERATURES EARLY THIS MORNING BUT SURFACE WINDS WILL BE RATHER LIGHT AS THE SURFACE HIGH BUILDS INTO THE MID MISSISSIPPI VALLEY. WIND CHILLS WILL BE MAINLY IN THE 10 TO 15 BELOW RANGE FOR A TIME. TEMPERATURES WILL DROP AGAIN EARLY TONIGHT...THEN BECOME STEADY OR SLOWLY RISING LATE AS SOUTHWEST WINDS DEVELOP BEHIND THE HIGH DROPPING INTO THE OHIO RIVER VALLEY. LIGHT WINDS IN THE 1 TO 3 THSD FT RANGE BECOME NORTH FOR A BRIEF TIME THIS MORNING AND MAY BRING LAKE CLOUDS CLOSE TO SHORE...BUT SHOULD REMAIN OUT OVER THE LAKE. FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM KEPT SOME FLURRIES IN THE FORECAST FOR FRIDAY AS A SHORTWAVE MOVES THROUGH...THOUGH MODEL SOUNDINGS ARE SHOWING A BIT MORE DRY AIR IN THE MID LEVELS THAN 24 HOURS AGO. ANOTHER WEAK WAVE WILL SLIDE THROUGH SATURDAY...BUT MOISTURE AND LIFT ARE LACKING ONCE AGAIN. SHOULD SEE MOSTLY CLOUDY SKIES...BUT HELD OFF ON MENTION OF FLURRIES FOR NOW. THE CANADIAN AND ECMWF ARE SHOWING A MORE POTENT WAVE FOR SATURDAY...WITH AN AREA OF RAIN/SNOW SLIDING ACROSS SOUTHERN WISCONSIN. THE GFS HAS A WEAK SYSTEM AND IS DRY. NOT A HIGH CONFIDENCE SETUP...SO WENT WITH SLIGHT CHANCE POPS. TEMPS ARE EXPECTED TO WARM TO AROUND NORMAL VALUES FOR THE WEEKEND. MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM THE FLOW WILL TURN MORE ZONAL FOR EARLY NEXT WEEK...ALLOWING FOR MILDER AIR TO MOVE INTO SOUTHERN WISCONSIN. COULD SOME 40S FOR THE FIRST TIME SINCE THE MIDDLE OF JANUARY...MAYBE EVEN 50 TUESDAY AND WEDNESDAY...WHICH HAS NOT HAPPENED SINCE MID-DECEMBER. SOME UNCERTAINTY WITH HOW MUCH THE SNOW PACK WILL IMPACT THE MILDER TEMPS. ALSO...IF DEWPOINTS GET HIGH ENOUGH WHILE THERE IS STILL SNOW ON THE GROUND...MIGHT HAVE TO DEAL WITH SOME FOG. MAY BE COOLER NEAR LAKE MICHIGAN WEDNESDAY...DEPENDING ON THE MODEL. THE GFS IS BREEZY SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT...WHICH WOULD RESULT IN MILDER TEMPS ACROSS THE FORECAST AREA. THE ECMWF HAS MUCH LIGHTER SOUTHERLY WINDS AND ALLOWS FOR ONSHORE WINDS AND COOLER TEMPS NEAR THE LAKE. AVIATION/12Z TAFS/... VFR CONDITIONS THROUGH THE FORECAST AS A LARGE HIGH MOVES ACROSS THE MID MISSISSIPPI VALLEY TOWARDS THE OHIO RIVER VALLEY. A FEW CLOUDS AROUND 25 HUNDRED FT ARE POSSIBLE THIS AFTERNOON. LIGHT WINDS IN THE 1 TO 3 THSD FT RANGE BECOME NORTH FOR A BRIEF TIME THIS MORNING AND MAY BRING LAKE CLOUDS CLOSE TO SHORE...BUT SHOULD REMAIN OUT OVER THE LAKE. MAINLY LIGHT NORTHWEST SURFACE WINDS WILL BECOME WEST TODAY THEN SOUTHWEST TONIGHT. MARINE... NORTHWEST WINDS WILL BECOME WEST AND CONTINUE TO EASE AS A LARGE HIGH OVER THE MID MISSISSIPPI VALLEY MOVES INTO THE OHIO RIVER VALLEY REGION. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...JTS TODAY/TONIGHT AND AVIATION/MARINE...HENTZ FRIDAY THROUGH WEDNESDAY...DDV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
414 PM EST THU MAR 5 2015 .SYNOPSIS... A WEAK LOW PRESSURE SYSTEM WILL TRACK ALONG AN ARCTIC COLD FRONT WELL SOUTH OF THE AREA THROUGH THIS EVENING. HIGH PRESSURE MOVES EAST THROUGH FRIDAY THEN PASSES SOUTH OF THE REGION THIS WEEKEND AS SEVERAL WEAK IMPULSES PASS TO THE NORTH. THE HIGH SLIDES OFFSHORE MONDAY NIGHT AND TUESDAY. A COLD FRONT PASSES THROUGH ON WEDNESDAY...FOLLOWED BY HIGH PRESSURE FOR THURSDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... BECAUSE HEAVY SNOW IS NO LONGER FORECAST FOR THE REST OF TODAY... WINTER STORM WARNINGS WERE REPLACED BY WINTER WEATHER ADVISORIES. DIFFICULT TRAVEL CONDITIONS EXPECTED THROUGH THIS EVENING WITH SNOW AND ICE COVERED ROADS AND TEMPERATURES DROPPING TO AROUND 20. BECAUSE ONLY FLURRIES ARE FORECAST ACROSS ORANGE...PUTNAM...NORTHERN FAIRFIELD AND NORTHERN NEW HAVEN COUNTIES WHERE MUCH LESS SNOW FELL...THE ADVISORIES WERE CANCELLED. A FEW BANDS OF MODERATE SNOW REDUCING VSBY TO 1/2 MILE IS POSSIBLE WITH UP TO AN ADDITIONAL INCH OF SNOW THRU 7 PM MAINLY ACROSS METRO NJ...NYC AND LONG ISLAND. FOR THE LATEST SNOWFALL AMOUNTS REFER TO THE LATEST PUBLIC INFORMATION STATEMENT UNDER THE NWS WEB PAGE TOP NEWS OF THE DAY. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY NIGHT/... UNTIL 10 PM...LIGHT SNOW WILL END ACROSS EASTERN LONG ISLAND AS THE UPPER LVL TROUGH APPROACHES WITH SYNOPTIC SCALE LIFT ADVECTING EAST OF THE AREA. AFTER 10 PM TONIGHT...AS AN ARCTIC HI PRES SYS BUILDS EAST TOWARD THE AREA...NW WINDS OF 10-20 MPH WILL COMBINE WITH OVERNIGHT LOWS OF 0 TO 15 DEGREES TO PRODUCE WIND CHILLS OF AROUND 0 DEGREES AFTER MIDNIGHT UNTIL 9 AM FRIDAY. ARCTIC HIGH PRES WILL PREVAIL WITH TEMPS AVERAGING AROUND 20 DEGS BELOW NORMAL FOR FRIDAY...IN THE MID 20S AND 15-20 DEGS BELOW NORMAL ON FRI NIGHT WITH LOWS FROM THE SINGLE DIGITS TO THE TEENS. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGH PRESSURE BUILDS SOUTH OF THE REGION THIS WEEKEND WITH A SERIES OF WEAK UPPER LEVEL SHORTWAVES PASSING NORTH OF THE REGION. EXPECT PARTLY TO MOSTLY CLOUDY SKIES WITH THE CHANCE OF SOME LIGHT SNOW SHOWERS LATE SATURDAY INTO SATURDAY NIGHT. ANY POPS WILL BE CONFINED TO LOCATIONS NORTH OF NYC. ANOTHER WAVE PASSES NORTH OF THE REGION SUNDAY NIGHT...FOLLOWED BY A THIRD WAVE LATE MONDAY...HOWEVER THINKING THE BEST CHANCE OF POPS WILL BE NORTH OF THE REGION SO WILL KEEP POPS OUT OF THE FORECAST FOR NOW. THE REGION IS THEN UNDER THE INFLUENCE OF HIGH PRESSURE MONDAY NIGHT THROUGH THE END OF THE WEEK WITH WARMING TEMPERATURES EACH DAY. A WEAK COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. TEMPERATURES WILL START OFF BELOW NORMAL WITH HIGHS IN THE LOWER 30S SATURDAY. A MODERATION WILL THEN COMMENCE EARLY NEXT WEEK AS HEIGHTS ALOFT GRADUALLY RISE...WITH TEMPERATURES NEAR NORMAL...IN THE MID TO UPPER 40S FOR HIGHS NEXT WEEK. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... RADAR DATA AND LATEST HRRR GUIDANCE INDICATE BACK EDGE OF SNOW GRADUALLY CROSSING NYC TERMINALS ATTM HOWEVER PROGRESS HAS BEEN SLOW. SNOW STARTING TO LIGHTEN UP AND VISIBILITIES HAVE BEEN INCREASING DESPITE PERSISTENT SNOW BANDING ACROSS IMMEDIATE COASTAL TAFS. SOME RADAR ENHANCEMENT STILL BACK ACROSS PA AND HRRR GUIDANCE BRINGS THIS THROUGH IN THE NEXT FEW HOURS. STILL EXPECT VFR TO RETURN AFTER 00Z BUT MAY BE DELAYED AN HOUR OR SO. WINDS TONIGHT INTO FRIDAY WILL BE OUT OF THE W-NW AROUND 10 KT. TOTAL RUNWAY SNOW ACCUMULATIONS: KISP...5-7 INCHES. KJFK/KLGA/KEWR/KTEB/KGON...4-6 INCHES. KHPN/KBDR...3-5 INCHES. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: SNOW WINDING DOWN IN NEXT 1-3 HOURS WITH SIGNIFICANT IMPROVEMENTS TO VFR AFT 01Z. KLGA FCSTER COMMENTS: SNOW WINDING DOWN IN NEXT 1-3 HOURS WITH SIGNIFICANT IMPROVEMENTS TO VFR AFT 01Z. KEWR FCSTER COMMENTS: SNOW WINDING DOWN IN NEXT 1-3 HOURS WITH SIGNIFICANT IMPROVEMENTS TO VFR AFT 00Z. KTEB FCSTER COMMENTS: SNOW WINDING DOWN IN NEXT 1-3 HOURS WITH SIGNIFICANT IMPROVEMENTS TO VFR AFT 00Z. KHPN FCSTER COMMENTS: SNOW WINDING DOWN IN NEXT 1-3 HOURS WITH SIGNIFICANT IMPROVEMENTS TO VFR AFT 00Z. KISP FCSTER COMMENTS: SNOW WINDING DOWN IN NEXT 1-3 HOURS WITH SIGNIFICANT IMPROVEMENTS TO VFR AFT 02Z. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... .FRI-TUE...MAINLY VFR. && .MARINE... SMALL CRAFT ADVISORY/SCA LEVELS FOR FREQUENT WIND GUSTS TO 25 KT AND SEAS AROUND 5 FEET ARE FORECAST TO CONTINUE UNTIL 11 AM ON FRIDAY. LIGHT FREEZING SPRAY IS ALSO FORECAST UNTIL 11 AM FRIDAY AS WELL. SUB SCA CONDS RETURN FRI AS HIGH PRESSURE BUILDS OVER THE WATERS. SCA CONDS ARE POSSIBLE...MAINLY ON THE OCEAN WATERS SAT IN THE WAKE OF A TROUGH OF LOW PRES. OTHERWISE...SUB-ADVSY CONDS ARE EXPECTED THROUGH THE PERIOD. && .HYDROLOGY... NO SIGNIFICANT PCPN IS EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...TEMPS FORECAST TO WARM INTO THE 40S MAY RESULT IN THE START OF ICE BREAK UP ON AREA RIVERS AND STREAMS. && .EQUIPMENT... NOAA WEATHER RADIO WEEKLY TEST WILL BE DELAYED UNTIL FRIDAY BETWEEN 11 AM AND NOON DUE TO ON GOING HAZARDOUS WEATHER. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR CTZ007>012. NY...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ069>075-078>081-176>179. NJ...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ002- 004-006-103>108. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST FRIDAY FOR ANZ350-353-355. && $$ SYNOPSIS...BC/GC NEAR TERM...GC SHORT TERM...GC LONG TERM...BC AVIATION...IRD MARINE...BC/GC HYDROLOGY...BC/GC EQUIPMENT...GC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
141 PM EST THU MAR 5 2015 .SYNOPSIS... A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL TRACK ALONG AN ARCTIC COLD FRONT MOVING FURTHER SOUTH OF THE AREA TODAY. CANADIAN HIGH PRESSURE BUILDS IN TONIGHT THROUGH FRIDAY...THEN BUILDS TO THE SOUTH THROUGH EARLY NEXT WEEK AS SEVERAL WEAK IMPULSES PASS TO THE NORTH. THE HIGH SLIDES OFFSHORE MONDAY NIGHT AND TUESDAY. A COLD FRONT PASSES THROUGH ON WEDNESDAY...FOLLOWED BY CANADIAN HIGH PRESSURE FOR THURSDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... UPGRADED WINTER WEATHER ADVISORY TO WINTER STORM WARNING FOR SOUTHERN MIDDLESEX AND SOUTHERN NEW LONDON COUNTIES IN CT BASED ON CURRENT SNOWFALL OBSERVATIONS AND NEAR TERM FORECAST TRENDS. BACK EDGE OF HVY SNOW BAND IS MVG SE FROM ACROSS CENTRAL NJ NE ACROSS SE CT...WITH HOURLY SNOWFALL RATES OF 1 INCH PLUS. AT 18Z/1 PM...5.5 INCHES AT CENTRAL PARK...5.0 INCHES HERE AT THE NWS OFFICE WITH MORE THAN 4 INCHES AT JFK AND LGA AIRPORTS. WE ARE ON TRACK FOR A WIDESPREAD 6-8 INCH SNOWFALL ACROSS THE WARNING AREA. REDEVELOPMENT OF SNOW CONTS ACROSS NW NJ WITH A LIGHTER BAND POSSIBLE ACROSS THE REGION FROM 19Z-21Z. WILL BE DROPPING ADVISORY ACROSS THE NORTHERN INTERIOR WITH THE NEXT FORECAST UPDATE AS DRY ARCTIC AIR CONTS TO FILTER SE ACROSS THIS REGION WITH DEW POINTS ALREADY NEAR ZERO. DIFFICULT TRAVEL CONDITIONS EXPECTED THROUGH THIS AFTERNOON WITH SNOW COVERED ROADS AND TEMPERATURES DROPPING THROUGH THE 20S CAUSING ICING OF UNTREATED SURFACES. FOR THE LATEST SNOWFALL AMOUNTS REFER TO THE LATEST PUBLIC INFORMATION STATEMENT UNDER THE NWS WEB PAGE TOP NEWS OF THE DAY. SNOW SHOULD END FROM NW TO SSE BETWEEN 00Z AND 03Z...WITH FRIGID AND DRY CONDITIONS TONIGHT. TEMPS EXPECTED TO DROP INTO THE SINGLE DIGITS...LOWER TEENS NYC METRO...ON GUSTY NW WINDS. WIND CHILLS LIKELY DROPPING TO AROUND ZERO FOR MUCH OF THE REGION BY FRIDAY MORNING. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/... HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT. SKIES WILL CLEAR FROM WEST TO EAST. WINDS SHOULD DIMINISH LATE AND WITH DRY CONDITIONS...EXPECTING AN UNSEASONABLY COLD NIGHT WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS FOR MOST LOCATIONS AND LOWER TO MIDDLE TEENS IN THE NYC METRO. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... A MEAN TROUGH WILL REMAIN EAST OF THE ROCKIES THROUGH EARLY NEXT WEEK. A SPLIT FLOW THEN DEVELOPS ACROSS THE CONUS WITH A FAST ACTIVE NORTHERN STREAM ACROSS SOUTHERN CANADA AND A BROAD TROUGH IN THE SOUTHERN STREAM EXTENDING FROM THE CENTRAL US THROUGH MEXICO. ZONAL H5 FLOW DEVELOPS ACROSS THE NORTHEAST AS A RESULT. OVERALL...EXPECT MOSTLY DRY CONDITIONS WITH HIGHS WARMING INTO THE 40S BY THE MIDDLE OF NEXT WEEK. A DECENT SHORTWAVE MOVES THROUGH THE NORTHEAST FRI NIGHT...BUT STRONG SUBSIDENCE WITH LIMITED MOISTURE IS EXPECTED TO KEEP THE LOCAL AREA DRY. A TROUGH OF LOW PRESSURE APPROACHES THE AREA SAT AND MOVES THROUGH SAT NIGHT. DOWN SLOPING FLOW ALOFT WILL LIKELY KEEP PCPN CONFINED TO THE WINDWARD SIDE OF THE APPALACHIANS WITH ONLY PERHAPS FLURRIES OR A FEW SNOW SHOWERS AT BEST LATE SAT NIGHT. THE NAM/GFS ARE INDICATING A WEAK LOW PRES SYSTEM MOVING FROM THE GREAT LAKES THROUGH THE NEW ENGLAND ON SUNDAY. EC IS MUCH WEAKER WITH NO PCPN. HAVE MAINTAINED DRY FORECAST AS PCPN REMAINS CONFINED MAINLY TO THE N WHERE BETTER DYNAMICS ARE PRESENT. FINAL NORTHERN STREAM SHORTWAVE PASSES THROUGH MON. GFS IS SLIGHTLY MORE AMPLIFIED ALOFT WITH THE VORT MAX PASSING DIRECTLY OVER THE AREA...ALTHOUGH NOT MUCH PCPN DUE TO RIDGING NOSING IN FROM THE S. EC IS FURTHER N. HAVE MAINTAINED SCHC POPS. SW-W FLOW ALOFT THEN DEVELOPS AT H5...ALTHOUGH LARGE DIFFERENCES BECOME PREVALENT BY THE MIDDLE OF THE WEEK. THE GFS BECOMES MUCH MORE AMPLIFIED WED/THU WITH SOUTHERN STREAM ENERGY BECOMING PICKED UP IN THE FLOW AND PASSING NEAR THE AREA WED. EC IS MUCH FLATTER WITH DRY WEATHER PREVAILING. REMAINING DRY WEATHER THEN PREVAILS POSSIBLY UNTIL MID WEEK. TEMPS WILL START OFF BELOW NORMAL WITH LOWS IN THE TEENS FRI NIGHT AND LOWER 30S SAT...BUT A MODERATION WILL THEN COMMENCE EARLY NEXT WEEK AS HEIGHTS ALOFT GRADUALLY RISE...WITH TEMPS NEAR NORMAL IN THE MID TO UPPER 40S FOR HIGHS AND LOWER 30S FOR LOWS NEXT WEEK. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... PERIODS OF MODERATE TO HEAVY SNOW CONTINUE NEAR THE COAST THROUGH THE AFTERNOON. RADAR DATA AND LATEST HRRR GUIDANCE STRONGLY SUGGEST LAST BAND OF HEAVIEST SNOW WILL CROSS NYC TERMINALS BETWEEN 18-21Z SO WE HAVE EXTENDED PERIOD OF HEAVIER SNOW BY AN ADDITIONAL 1-3 HOURS IN TAF. BASED ON THE LATEST DATA...BACK EDGE OF SNOW SHOULD SWING THROUGH REGION BY 00Z AND EXPECT VFR TO RETURN AFTER 00Z. KSWF IS ALREADY NORTH OF THE HEAVIEST SNOW...SO MVFR TO VFR IS EXPECTED. WINDS WILL BE OUT OF THE NW AROUND 10-12 KT THROUGH TONIGHT WITH SOME GUSTS TO 15-20 KT THIS AFTERNOON. WINDS DIMINISH LATE TONIGHT INTO FRIDAY. OVERALL...HIGHER CONFIDENCE WITH WINDS AND LOWER CONFIDENCE WITH CATEGORICAL CHANGES WHICH COULD VARY A FEW HOURS WITH SUBSEQUENT FORECASTS. EXPECTED RUNWAY SNOW ACCUMULATIONS: KISP...6-8 INCHES. KJFK/KLGA/KEWR/KTEB/KGON...4-6 INCHES. KHPN/KBDR...3-5 INCHES. KSWF...1-2 INCHES. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KLGA FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KEWR FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KTEB FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KHPN FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KISP FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... .FRI-TUE...MAINLY VFR. && .MARINE... SMALL CRAFT ADVISORY CONDITIONS CONTINUE ON THE COASTAL OCEAN WATERS INTO FRIDAY MORNING AS A SERIES OF LOW PRESSURE WAVES TRACKS TO THE SOUTH OF THE WATERS AND HIGH PRESSURE BUILDS IN FROM THE WEST. MARGINAL SCA GUSTS TODAY...WITH STRONGEST WINDS TONIGHT. SEAS WILL RUN 4 TO 6 FT THROUGH THE PERIOD...WITH SOUTHERLY SWELLS PREDOMINANT TODAY. LIGHT FREEZING SPRAY EXPECTED TO DEVELOP THIS AFTERNOON ACROSS THE OCEAN WATERS...POSSIBLY BECOMING MODERATE LATE TONIGHT. A PERIOD OF FREEZING SPRAY POSSIBLE ON LI SOUND AS WELL LATE TONIGHT. SUB SCA CONDS RETURN FRI AS HIGH PRESSURE BUILDS OVER THE WATERS. SCA CONDS ARE POSSIBLE...MAINLY ON THE OCEAN WATERS SAT IN THE WAKE OF A TROUGH OF LOW PRES. OTHERWISE...SUB-ADVSY CONDS ARE EXPECTED THROUGH THE PERIOD. && .HYDROLOGY... 1/10 TO 7/10 INCH LIQUID EQUIVALENT PRECIPITATION TODAY. THIS WILL BE FROZEN...SO HYDROLOGIC IMPACTS ARE NOT EXPECTED. NO SIGNIFICANT PCPN IS EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...TEMPS FORECAST TO WARM INTO THE 40S MAY RESULT IN THE START OF ICE BREAK UP ON AREA RIVERS AND STREAMS. && .EQUIPMENT... NOAA WEATHER RADIO WEEKLY TEST WILL BE DELAYED UNTIL FRIDAY BETWEEN 11 AM AND NOON DUE TO ON GOING HAZARDOUS WEATHER. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR CTZ011- 012. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR CTZ005>010. NY...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ072>075-078>081-176>179. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ067>071. NJ...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ006- 106>108. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ002- 004-103>105. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST FRIDAY FOR ANZ350-353-355. && $$ SYNOPSIS...GC NEAR TERM...GC SHORT TERM...NV LONG TERM...24 AVIATION...IRD MARINE...24/NV HYDROLOGY...24/NV EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1246 PM EST THU MAR 5 2015 .SYNOPSIS... A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL TRACK ALONG AN ARCTIC COLD FRONT MOVING FURTHER SOUTH OF THE AREA TODAY. CANADIAN HIGH PRESSURE BUILDS IN TONIGHT THROUGH FRIDAY...THEN BUILDS TO THE SOUTH THROUGH EARLY NEXT WEEK AS SEVERAL WEAK IMPULSES PASS TO THE NORTH. THE HIGH SLIDES OFFSHORE MONDAY NIGHT AND TUESDAY. A COLD FRONT PASSES THROUGH ON WEDNESDAY...FOLLOWED BY CANADIAN HIGH PRESSURE FOR THURSDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... THE NEXT BAND OF HVY SNOW IS MOVING EAST ACROSS NORTHERN NJ AND THE LOWER HUDSON VALLEY WITH HOURLY SNOWFALL RATES OF AT LEAST 1 INCH PER HOUR AS SHOWN BY NEWARK`S LATEST 17Z SNINCR METAR OBSERVATION. FOR THE LATEST SNOWFALL AMOUNTS REFER TO THE LATEST PUBLIC INFORMATION STATEMENT UNDER TOP NEWS OF THE DAY. THE HEAVIEST MEASURED SNOWFALL REPORTS ARE AROUND 5 INCHES THROUGH NOON. WE WILL BE RECEIVING THE LATEST SNOWFALL UPDATES FROM OUR FIRST ORDER CLIMATE STATIONS AROUND 1 PM. STAY TUNED. OTHERWISE...CONTINUED TO STAIR STEP INCREASING SNOWFALL AMOUNTS AS THE SNOWFALL RATIOS WILL INCREASE TO 15-20 TO 1 AFT 18Z. STORM TOTAL SNOWFALL FOR THE WARNING AREA...WIDESPREAD 6-8 INCHES WITH ISOLATED AMOUNTS UP TO 10 INCHES. ADVISORIES ISSUED FURTHER NORTH ACROSS NORTHERN FAIRFIELD...NORTHERN NEW HAVEN AND ORANGE AND PUTNAM COUNTIES. FOR THOSE UNDER THE ADVISORY AREA...A WIDESPREAD 4 TO 6 INCHES WITH ISOLATED 8 INCH AMOUNTS. THE CURRENT FORECAST IS ON TRACK. NO CHANGES WILL BE MADE TO THE CURRENT STATUS OF WINTER STORM WARNINGS AND ADVISORIES. THE FOLLOWING LOCATIONS REPORTED 2 CONSECUTIVE HOURS OF 1 INCH SNOWFALL INCREASES AT 13Z AND 14Z...EWR / LGA / JFK / ISP. BASED ON CURRENT OBSERVATIONS AND NEAR TERM FORECAST TRENDS...EXPECT SNOWFALL INTENSITIES TO RANGE FROM LIGHT TO HEAVY WITH THE APPROACH AND PASSAGE OF EACH WAVE OF LOW PRESSURE RIDING ALONG THE ARCTIC FRONT SOUTH OF THE AREA. RAISED SNOWFALL AMOUNTS UP TO 1 INCH ACROSS THE WARNING AREA...MAINLY THROUGH 18Z. ANY LINGERING SNOW ACROSS SOUTHEAST LONG ISLAND COMES TO AND END THIS EVENING...WITH FRIGID AND BUT DRYING CONDITIONS TONIGHT. TEMPS EXPECTED TO DROP INTO THE SINGLE DIGITS...LOWER TEENS NYC METRO...ON GUSTY NW WINDS. WIND CHILLS LIKELY DROPPING TO AROUND ZERO FOR MUCH OF THE REGION BY FRIDAY MORNING. D DIFFICULT TRAVEL CONDITIONS EXPECTED THROUGH THIS AFTERNOON WITH SNOW COVERED ROADS AND TEMPERATURES DROPPING THROUGH THE 20S CAUSING ICING OF UNTREATED SURFACES. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/... HIGH PRESSURE BUILDS IN FROM THE WEST THURSDAY NIGHT. SKIES WILL CLEAR FROM WEST TO EAST. WINDS SHOULD DIMINISH LATE AND WITH DRY CONDITIONS...EXPECTING AN UNSEASONABLY COLD NIGHT WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS FOR MOST LOCATIONS AND LOWER TO MIDDLE TEENS IN THE NYC METRO. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A MEAN TROUGH WILL REMAIN EAST OF THE ROCKIES THROUGH EARLY NEXT WEEK. A SPLIT FLOW THEN DEVELOPS ACROSS THE CONUS WITH A FAST ACTIVE NORTHERN STREAM ACROSS SOUTHERN CANADA AND A BROAD TROUGH IN THE SOUTHERN STREAM EXTENDING FROM THE CENTRAL US THROUGH MEXICO. ZONAL H5 FLOW DEVELOPS ACROSS THE NORTHEAST AS A RESULT. OVERALL...EXPECT MOSTLY DRY CONDITIONS WITH HIGHS WARMING INTO THE 40S BY THE MIDDLE OF NEXT WEEK. A DECENT SHORTWAVE MOVES THROUGH THE NORTHEAST FRI NIGHT...BUT STRONG SUBSIDENCE WITH LIMITED MOISTURE IS EXPECTED TO KEEP THE LOCAL AREA DRY. A TROUGH OF LOW PRESSURE APPROACHES THE AREA SAT AND MOVES THROUGH SAT NIGHT. DOWN SLOPING FLOW ALOFT WILL LIKELY KEEP PCPN CONFINED TO THE WINDWARD SIDE OF THE APPALACHIANS WITH ONLY PERHAPS FLURRIES OR A FEW SNOW SHOWERS AT BEST LATE SAT NIGHT. THE NAM/GFS ARE INDICATING A WEAK LOW PRES SYSTEM MOVING FROM THE GREAT LAKES THROUGH THE NEW ENGLAND ON SUNDAY. EC IS MUCH WEAKER WITH NO PCPN. HAVE MAINTAINED DRY FORECAST AS PCPN REMAINS CONFINED MAINLY TO THE N WHERE BETTER DYNAMICS ARE PRESENT. FINAL NORTHERN STREAM SHORTWAVE PASSES THROUGH MON. GFS IS SLIGHTLY MORE AMPLIFIED ALOFT WITH THE VORT MAX PASSING DIRECTLY OVER THE AREA...ALTHOUGH NOT MUCH PCPN DUE TO RIDGING NOSING IN FROM THE S. EC IS FURTHER N. HAVE MAINTAINED SCHC POPS. SW-W FLOW ALOFT THEN DEVELOPS AT H5...ALTHOUGH LARGE DIFFERENCES BECOME PREVALENT BY THE MIDDLE OF THE WEEK. THE GFS BECOMES MUCH MORE AMPLIFIED WED/THU WITH SOUTHERN STREAM ENERGY BECOMING PICKED UP IN THE FLOW AND PASSING NEAR THE AREA WED. EC IS MUCH FLATTER WITH DRY WEATHER PREVAILING. REMAINING DRY WEATHER THEN PREVAILS POSSIBLY UNTIL MID WEEK. TEMPS WILL START OFF BELOW NORMAL WITH LOWS IN THE TEENS FRI NIGHT AND LOWER 30S SAT...BUT A MODERATION WILL THEN COMMENCE EARLY NEXT WEEK AS HEIGHTS ALOFT GRADUALLY RISE...WITH TEMPS NEAR NORMAL IN THE MID TO UPPER 40S FOR HIGHS AND LOWER 30S FOR LOWS NEXT WEEK. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... PERIODS OF MODERATE TO HEAVY SNOW CONTINUE NEAR THE COAST THROUGH THE AFTERNOON. RADAR DATA AND LATEST HRRR GUIDANCE STRONGLY SUGGEST LAST BAND OF HEAVIEST SNOW WILL CROSS NYC TERMINALS BETWEEN 18-21Z SO WE HAVE EXTENDED PERIOD OF HEAVIER SNOW BY AN ADDITIONAL 1-3 HOURS IN TAF. BASED ON THE LATEST DATA...BACK EDGE OF SNOW SHOULD SWING THROUGH REGION BY 00Z AND EXPECT VFR TO RETURN AFTER 00Z. KSWF IS ALREADY NORTH OF THE HEAVIEST SNOW...SO MVFR TO VFR IS EXPECTED. WINDS WILL BE OUT OF THE NW AROUND 10-12 KT THROUGH TONIGHT WITH SOME GUSTS TO 15-20 KT THIS AFTERNOON. WINDS DIMINISH LATE TONIGHT INTO FRIDAY. OVERALL...HIGHER CONFIDENCE WITH WINDS AND LOWER CONFIDENCE WITH CATEGORICAL CHANGES WHICH COULD VARY A FEW HOURS WITH SUBSEQUENT FORECASTS. EXPECTED RUNWAY SNOW ACCUMULATIONS: KISP...6-8 INCHES. KJFK/KLGA/KEWR/KTEB/KGON...4-6 INCHES. KHPN/KBDR...3-5 INCHES. KSWF...1-2 INCHES. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KLGA FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KEWR FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KTEB FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KHPN FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. KISP FCSTER COMMENTS: FORECAST TIMING OF CATEGORY CHANGES COULD DIFFER 1-3 HRS FROM OBSERVED. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... .FRI-TUE...MAINLY VFR. && .MARINE... SMALL CRAFT ADVISORY CONDITIONS CONTINUE ON THE COASTAL OCEAN WATERS INTO FRIDAY MORNING AS A SERIES OF LOW PRESSURE WAVES TRACKS TO THE SOUTH OF THE WATERS AND HIGH PRESSURE BUILDS IN FROM THE WEST. MARGINAL SCA GUSTS TODAY...WITH STRONGEST WINDS TONIGHT. SEAS WILL RUN 4 TO 6 FT THROUGH THE PERIOD...WITH SOUTHERLY SWELLS PREDOMINANT TODAY. LIGHT FREEZING SPRAY EXPECTED TO DEVELOP THIS AFTERNOON ACROSS THE OCEAN WATERS...POSSIBLY BECOMING MODERATE LATE TONIGHT. A PERIOD OF FREEZING SPRAY POSSIBLE ON LI SOUND AS WELL LATE TONIGHT. SUB SCA CONDS RETURN FRI AS HIGH PRESSURE BUILDS OVER THE WATERS. SCA CONDS ARE POSSIBLE...MAINLY ON THE OCEAN WATERS SAT IN THE WAKE OF A TROUGH OF LOW PRES. OTHERWISE...SUB-ADVSY CONDS ARE EXPECTED THROUGH THE PERIOD. && .HYDROLOGY... 1/10 TO 7/10 INCH LIQUID EQUIVALENT PRECIPITATION TODAY. THIS WILL BE FROZEN...SO HYDROLOGIC IMPACTS ARE NOT EXPECTED. NO SIGNIFICANT PCPN IS EXPECTED THROUGH EARLY NEXT WEEK. HOWEVER...TEMPS FORECAST TO WARM INTO THE 40S MAY RESULT IN THE START OF ICE BREAK UP ON AREA RIVERS AND STREAMS. && .EQUIPMENT... NOAA WEATHER RADIO WEEKLY TEST WILL BE DELAYED UNTIL FRIDAY BETWEEN 11 AM AND NOON DUE TO ON GOING HAZARDOUS WEATHER. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR CTZ005>012. NY...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ072>075-078>081-176>179. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ067>071. NJ...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ006- 106>108. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ002- 004-103>105. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST FRIDAY FOR ANZ350-353-355. && $$ SYNOPSIS...GC NEAR TERM...GC SHORT TERM...NV LONG TERM...24 AVIATION...IRD MARINE...24/NV HYDROLOGY...24/NV EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
431 PM EST THU MAR 5 2015 .SYNOPSIS... A STORM SYSTEM WILL EXIT TO OUR EAST THIS EVENING, THEN ARCTIC HIGH PRESSURE BUILDS IN OVERNIGHT AND FRIDAY. THE HIGH WILL THEN SETTLE TO OUR SOUTH ON SATURDAY. A WEAK LOW PRESSURE SYSTEM WILL TRACK TO OUR NORTH LATE SUNDAY INTO MONDAY, PULLING A COLD FRONT ACROSS OUR REGION ON MONDAY. HIGH PRESSURE SHOULD THEN BUILD INTO THE AREA TUESDAY INTO WEDNESDAY, WITH THE NEXT COLD FRONT SCHEDULED TO ARRIVE LATER WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... FOR THE POCONOS AND NORTHWEST NJ, SNOW HAS ENDED AND THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE. TOTAL ACCUMULATIONS OF A FEW INCHES OCCURRED WITH A SHARP CUTOFF AS YOU GO NORTH IN THIS REGION. FOR THE LEHIGH VALLEY, SNOW WILL BE ENDING BY SUNSET AND A WINTER STORM WARNING CONTINUES UNTIL 7PM. NUMEROUS REPORTS OF AROUND SIX INCHES HAVE COME IN WITH LOCALLY HIGHER TOTALS AND THESE HAVE BEEN REFLECTED IN THE STORM TOTAL WEB MAP. FOR CENTRAL NEW JERSEY AND THE PHILADELPHIA METRO REGION, A COUPLE MORE HOURS OF MODERATE, BRIEFLY HEAVY SNOW ARE POSSIBLE BEFORE ENDING SHORTLY AFTER SUNSET. TOTAL ACCUMULATIONS 6-8, ISOLATED HIGHER. IN THE DELMARVA AND SOUTHEAST NEW JERSEY, THE CHANGEOVER WAS SLOW THIS AFTERNOON AND THIS WILL CUT INTO THE ACCUMULATIONS OF SNOW AND SLEET. FAVORABLE ISENTROPIC LIFT AND 700MB FRONTOGENETICAL FORCING ARE TAKING PLACE RESULTING IN HEAVIER BANDING, SO NOT A DRASTIC REDUCTION IN TOTALS. SUSSEX AND CAPE MAY COUNTIES MAY HAVE THE HARDEST TIME REACHING WARNING CRITERIA (4-6 OR SO) WITH AREAS FURTHER NORTH ENDING UP WITH 6 INCHES OR SO. FOR ADDITIONAL SNOW MAINLY USED THE RAP AND WPC QPF AS A GUIDELINE AND TOOK INTO ACCOUNT CURRENT OBS TO MAKE THE SNOW TOTAL FORECASTS REFERENCED ABOVE. TEMPERATURES WILL TUMBLE ONCE SKIES CLEAR. THIS SHOULD TAKE PLACE FAIRLY QUICKLY AFTER THE SNOW ENDS GIVEN A STEEP DROP IN DEW POINTS AND CONSIDERABLE DRY AIR ADVECTION. RECORD LOWS ARE POSSIBLE, PLEASE SEE CLIMATE SECTION BELOW. LOW TEMPERATURES TONIGHT ARE COMPOSED OF MET/MAV AND THE MODELED TWO METER TEMPERATURES FROM THE GFS WHICH HAS DONE WELL AT NIGHT WITH SNOW COVER. WIND CHILLS ARE LIKELY TO FALL BELOW ZERO ACROSS MOST OF THE REGION, WITH THE POCONOS SEEING WIND CHILLS WHICH MAY GET CLOSE TO ADVISORY THRESHOLD FOR A FEW HOURS. GIVEN THE LIMITED WINDOW AND MARGINAL VALUES IN TERMS OF AND ADVISORY, WILL JUST CONTINUE MENTION IN THE HWO. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... SUNNY DAY WITH HIGH PRESSURE BUILDING IN ON FRIDAY BUT STILL COLD. DID GO A TOUCH WARMER THAN MAV/MET GIVEN THE COOL DAYTIME BIAS WITH SNOW COVER. OTHER ELEMENTS STRAIGHT MAV/MET. CONTINUED NORTHWESTERLY WINDS UNDER 10 MPH OR SO. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... THE OVERALL SYNOPTIC SETUP IS COMPRISED OF AN UPPER-LEVEL TROUGH FROM THE MIDWEST TO THE NORTHEAST AND MID ATLANTIC. AS SHORT WAVE ENERGY MOVES THROUGH THE FLOW, THIS FEATURE SHOULD AMPLIFY A LITTLE FOR A TIME OR TWO. THIS SHOULD EVENTUALLY WEAKEN AS ENERGY EJECTS ACROSS THE SOUTHERN PLAINS LATE IN THE WEEKEND AND EARLY NEXT WEEK, WITH A RIDGE POTENTIALLY BUILDING OFF THE SOUTHEASTERN U.S. COAST. THIS RESULTS IN THE UPPER-LEVEL FLOW TURNING MORE ZONAL NEXT WEEK. WE USED A MODEL BLEND FOR FRIDAY NIGHT THROUGH SUNDAY, THEN WENT WITH THE 12Z WPC GUIDANCE THEREAFTER. WE THEN MADE SOME ADJUSTMENTS AFTER ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES. FOR FRIDAY NIGHT AND SATURDAY...A SHORT WAVE TROUGH LOOKS TO SLIDE ACROSS THE AREA, HOWEVER A DRY AIRMASS RESULTS IN NO PRECIPITATION. AT THE SURFACE, HIGH PRESSURE BUILDS OVER THE AREA HOWEVER ITS CENTER SLIDES TO OUR SOUTH THROUGH SATURDAY. THIS WILL RESULT IN A GRADUAL RETURN FLOW BEING ESTABLISHED AND AFTER A VERY COLD START SATURDAY, SOME MODERATION IS EXPECTED IN THE AFTERNOON. FOR SUNDAY AND MONDAY...A SHORT WAVE IS FORECAST TO TRACK NEAR THE MIDWEST AND GREAT LAKES SUNDAY, THEN WELL TO OUR NORTH MONDAY. THIS WILL DRIVE WEAK LOW PRESSURE WELL TO OUR NORTH, HOWEVER A COLD FRONT IS FORECAST TO MOVE THROUGH DURING MONDAY. IT APPEARS THAT THE MOISTURE WILL BE LACKING WITH THIS FEATURE AS MUCH OF THE LIFT OCCURS WELL TO OUR NORTH. THERE COULD BE A SNOW SHOWER THOUGH SUNDAY NIGHT INTO MONDAY ACROSS THE FAR NORTHWEST. OTHERWISE, THE AIRMASS IS FORECAST TO CONTINUE TO MODIFY AS THE FLOW COMES MORE FROM THE WEST AND NOT THE NORTH. FOR TUESDAY AND WEDNESDAY...HIGH PRESSURE SHOULD SHIFT TO OUR EAST AS A COLD FRONT MOVES ACROSS THE MIDWEST AND THE GREAT LAKES. LOW PRESSURE APPEARS TO TRACK WELL TO OUR NORTH ONCE AGAIN, WITH A WARM FRONT LIFTING MOSTLY TO OUR NORTHWEST. WHILE THE FLOW LOOKS FAIRLY WEAK, ENOUGH WAA IS EXPECTED TO OCCUR TO ALLOW FOR FURTHER MODERATION OF THE AIRMASS WITH MANY AREAS GETTING INTO THE LOWER 50S WEDNESDAY AFTERNOON. THE COLD FRONT SHOULD BE ARRIVING LATE WEDNESDAY, HOWEVER GIVEN THE TRACK OF THE SURFACE LOW AND SHORT WAVE ALOFT IT ALSO LOOKS TO BE MOISTURE STARVED. FOR THURSDAY...A WEAK SURFACE HIGH IS ANTICIPATED TO MOVE ACROSS THE AREA, WHILE A FRONTAL BOUNDARY IS DRAPED FROM NEAR MAINE TO THE GREAT LAKES THEN INTO THE CENTRAL PLAINS. THE AIRMASS SHOULD BE MUCH MILDER WITH AFTERNOON HIGHS GETTING INTO THE 50S. THE OCEAN AND DELAWARE BAY ARE COLD AND IF THERE IS LIGHT ENOUGH FLOW, THEN A COOLING AFFECT CAN BE EXPECTED CLOSER TO THE COAST. && .AVIATION /22Z THURSDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. LIFR AND IFR CONDITIONS WILL LIKELY BE PRESENT AT ALL TAF SITES INTO THE EVENING WITH ACCUMULATING SNOW. KRDG AND KABE WILL BE FIRST TO IMPROVE TO VFR BY 00Z 3/6. OTHER TAF SITES WILL FOLLOW WITH AN IMPROVEMENT TO VFR WITH KACY LAST AROUND 03Z. NORTHERLY WINDS BETWEEN 10 AND 15 KNOTS ARE EXPECTED AS WELL INTO THE EVENING, POTENTIALLY LASTING LONGER THAN CURRENT TAFS INDICATE. OVERNIGHT NORTH TO NORTHWEST WINDS SHOULD SLACKEN SLIGHTLY WITH CONTINUED VFR CONDITIONS ON FRIDAY. OUTLOOK... FRIDAY NIGHT THROUGH SUNDAY...VFR OVERALL. A WEAK SYSTEM MOVING BY LATER SATURDAY SHOULD RESULT IN MORE CLOUDS, HOWEVER ANY PRECIPITATION LOOKS TO STAY TO OUR NORTH AND WEST. MONDAY AND TUESDAY...VFR OVERALL. A WEAK COLD FRONT MOVING THROUGH MONDAY SHOULD RESULT IN MORE CLOUDS, HOWEVER IT APPEARS THAT IT MOVES THROUGH DRY. && .MARINE... WAVES ALONG THE COASTAL WATERS WILL CONTINUE TO REMAIN NEAR OR ABOVE 5 FT. IN ADDITION, WINDS ARE EXPECTED TO INCREASE SLIGHTLY THROUGH THE EVENING HOURS OUT OF THE NORTH NORTHWEST. THEREFORE THE SMALL CRAFT ADVISORY CONTINUES ON THE ATLANTIC COASTAL WATERS THROUGH THE OVERNIGHT HOURS. ON THE BAY, A FEW GUSTS ABOVE 20 KT ARE POSSIBLE, BUT CONDITIONS SHOULD GENERALLY STAY BELOW SMALL CRAFT ADVISORY CRITERIA. FOR FRIDAY, WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA. OUTLOOK... FRIDAY NIGHT AND SATURDAY...THE CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CRITERIA, HOWEVER THE WINDS WILL INCREASE SOME FROM THE WEST-SOUTHWEST DURING SATURDAY. THERE IS A CHC FOR SOME LIGHT FREEZING SPRAY FRIDAY NIGHT AND SATURDAY MORNING. SUNDAY THROUGH TUESDAY...WE ARE ANTICIPATING SUB SMALL CRAFT ADVISORY CONDITIONS AS A WEAK FRONT MOVES THROUGH MAINLY DURING MONDAY. && .CLIMATE... WITH A SNOW COVER IN PLACE AND ANOTHER ARCTIC AIRMASS SETTLING INTO THE REGION AND RADIATIONAL COOLING OCCURRING WE HAVE ANOTHER CHANCE FOR MORE RECORD LOWS ACROSS THE REGION. FRIDAY 3/6 RECORD LOWS ACY 10 1888 PHL 10 1978 ILG 11 1926 ABE 7 1960 TTN 7 1872 GED 10 1978 RDG 7 1978 MPO -5 1909 THE CURRENT FORECAST CURRENTLY HAS MOST LOCATIONS BREAKING THERE RECORD LOW ON FRIDAY MORNING. THE ONE EXCEPTION WOULD BE MOUNT POCONO. SATURDAY 3/7 RECORD LOWS ACY 10 1890 PHL 9 1960 ILG 11 1960 ABE 1 1960 TTN 7 1890 GED 3 1960 RDG 10 1989 MPO -18 1911 IT APPEARS THAT READING AND ATLANTIC CITY HAVE THE BETTER CHANCE OF GETTING TO THEIR RECORD LOW SATURDAY MORNING. RECORD DAILY SNOWFALL FOR THURSDAY MARCH 5 RECORD EVENT REPORTS WILL BE SENT SHORTLY FOR KACY AND KILG AND THOSE WILL BE UPDATED AT 7 PM TONIGHT. WE MAY NEED OTHERS LATER THIS EVENING. KACY 0.3 - 1960 KILG 3.7 - 1981 KABE 7.0 - 1917 KPHL 8.8 - 1981 FWIW...WATER EQUIVALENCE OF TOTAL SNOW DEPTH IN PORTIONS OF EASTERN PA IS NOW WELL OVER 3 INCHES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ060>062-070-071-101>106. NJ...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ007>010-012>027. DE...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ008- 012-015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ450>455. && $$ SYNOPSIS...GORSE NEAR TERM...GAINES SHORT TERM...GAINES LONG TERM...GORSE AVIATION...GAINES/GORSE/O`HARA MARINE...GORSE/JOHNSON/O`HARA CLIMATE...DRAG 430P
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
338 PM EST THU MAR 5 2015 .SYNOPSIS... A STORM SYSTEM WILL EXIT TO OUR EAST THIS EVENING, THEN ARCTIC HIGH PRESSURE BUILDS IN OVERNIGHT AND FRIDAY. THE HIGH WILL THEN SETTLE TO OUR SOUTH ON SATURDAY. A WEAK LOW PRESSURE SYSTEM WILL TRACK TO OUR NORTH LATE SUNDAY INTO MONDAY, PULLING A COLD FRONT ACROSS OUR REGION ON MONDAY. HIGH PRESSURE SHOULD THEN BUILD INTO THE AREA TUESDAY INTO WEDNESDAY, WITH THE NEXT COLD FRONT SCHEDULED TO ARRIVE LATER WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... FOR THE POCONOS AND NORTHWEST NJ, SNOW HAS ENDED AND THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE. TOTAL ACCUMULATIONS OF A FEW INCHES OCCURRED WITH A SHARP CUTOFF AS YOU GO NORTH IN THIS REGION. FOR THE LEHIGH VALLEY, SNOW WILL BE ENDING BY SUNSET AND A WINTER STORM WARNING CONTINUES UNTIL 7PM. NUMEROUS REPORTS OF AROUND SIX INCHES HAVE COME IN WITH LOCALLY HIGHER TOTALS AND THESE HAVE BEEN REFLECTED IN THE STORM TOTAL WEB MAP. FOR CENTRAL NEW JERSEY AND THE PHILADELPHIA METRO REGION, A COUPLE MORE HOURS OF MODERATE, BRIEFLY HEAVY SNOW ARE POSSIBLE BEFORE ENDING SHORTLY AFTER SUNSET. TOTAL ACCUMULATIONS 6-8, ISOLATED HIGHER. IN THE DELMARVA AND SOUTHEAST NEW JERSEY, THE CHANGEOVER WAS SLOW THIS AFTERNOON AND THIS WILL CUT INTO THE ACCUMULATIONS OF SNOW AND SLEET. FAVORABLE ISENTROPIC LIFT AND 700MB FRONTOGENETICAL FORCING ARE TAKING PLACE RESULTING IN HEAVIER BANDING, SO NOT A DRASTIC REDUCTION IN TOTALS. SUSSEX AND CAPE MAY COUNTIES MAY HAVE THE HARDEST TIME REACHING WARNING CRITERIA (4-6 OR SO) WITH AREAS FURTHER NORTH ENDING UP WITH 6 INCHES OR SO. FOR ADDITIONAL SNOW MAINLY USED THE RAP AND WPC QPF AS A GUIDELINE AND TOOK INTO ACCOUNT CURRENT OBS TO MAKE THE SNOW TOTAL FORECASTS REFERENCED ABOVE. TEMPERATURES WILL TUMBLE ONCE SKIES CLEAR. THIS SHOULD TAKE PLACE FAIRLY QUICKLY AFTER THE SNOW ENDS GIVEN A STEEP DROP IN DEW POINTS AND CONSIDERABLE DRY AIR ADVECTION. RECORD LOWS ARE POSSIBLE, PLEASE SEE CLIMATE SECTION BELOW. LOW TEMPERATURES TONIGHT ARE COMPOSED OF MET/MAV AND THE MODELED TWO METER TEMPERATURES FROM THE GFS WHICH HAS DONE WELL AT NIGHT WITH SNOW COVER. WIND CHILLS ARE LIKELY TO FALL BELOW ZERO ACROSS MOST OF THE REGION, WITH THE POCONOS SEEING WIND CHILLS WHICH MAY GET CLOSE TO ADVISORY THRESHOLD FOR A FEW HOURS. GIVEN THE LIMITED WINDOW AND MARGINAL VALUES IN TERMS OF AND ADVISORY, WILL JUST CONTINUE MENTION IN THE HWO. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... SUNNY DAY WITH HIGH PRESSURE BUILDING IN ON FRIDAY BUT STILL COLD. DID GO A TOUCH WARMER THAN MAV/MET GIVEN THE COOL DAYTIME BIAS WITH SNOW COVER. OTHER ELEMENTS STRAIGHT MAV/MET. CONTINUED NORTHWESTERLY WINDS UNDER 10 MPH OR SO. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... THE OVERALL SYNOPTIC SETUP IS COMPRISED OF AN UPPER-LEVEL TROUGH FROM THE MIDWEST TO THE NORTHEAST AND MID ATLANTIC. AS SHORT WAVE ENERGY MOVES THROUGH THE FLOW, THIS FEATURE SHOULD AMPLIFY A LITTLE FOR A TIME OR TWO. THIS SHOULD EVENTUALLY WEAKEN AS ENERGY EJECTS ACROSS THE SOUTHERN PLAINS LATE IN THE WEEKEND AND EARLY NEXT WEEK, WITH A RIDGE POTENTIALLY BUILDING OFF THE SOUTHEASTERN U.S. COAST. THIS RESULTS IN THE UPPER-LEVEL FLOW TURNING MORE ZONAL NEXT WEEK. WE USED A MODEL BLEND FOR FRIDAY NIGHT THROUGH SUNDAY, THEN WENT WITH THE 12Z WPC GUIDANCE THEREAFTER. WE THEN MADE SOME ADJUSTMENTS AFTER ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES. FOR FRIDAY NIGHT AND SATURDAY...A SHORT WAVE TROUGH LOOKS TO SLIDE ACROSS THE AREA, HOWEVER A DRY AIRMASS RESULTS IN NO PRECIPITATION. AT THE SURFACE, HIGH PRESSURE BUILDS OVER THE AREA HOWEVER ITS CENTER SLIDES TO OUR SOUTH THROUGH SATURDAY. THIS WILL RESULT IN A GRADUAL RETURN FLOW BEING ESTABLISHED AND AFTER A VERY COLD START SATURDAY, SOME MODERATION IS EXPECTED IN THE AFTERNOON. FOR SUNDAY AND MONDAY...A SHORT WAVE IS FORECAST TO TRACK NEAR THE MIDWEST AND GREAT LAKES SUNDAY, THEN WELL TO OUR NORTH MONDAY. THIS WILL DRIVE WEAK LOW PRESSURE WELL TO OUR NORTH, HOWEVER A COLD FRONT IS FORECAST TO MOVE THROUGH DURING MONDAY. IT APPEARS THAT THE MOISTURE WILL BE LACKING WITH THIS FEATURE AS MUCH OF THE LIFT OCCURS WELL TO OUR NORTH. THERE COULD BE A SNOW SHOWER THOUGH SUNDAY NIGHT INTO MONDAY ACROSS THE FAR NORTHWEST. OTHERWISE, THE AIRMASS IS FORECAST TO CONTINUE TO MODIFY AS THE FLOW COMES MORE FROM THE WEST AND NOT THE NORTH. FOR TUESDAY AND WEDNESDAY...HIGH PRESSURE SHOULD SHIFT TO OUR EAST AS A COLD FRONT MOVES ACROSS THE MIDWEST AND THE GREAT LAKES. LOW PRESSURE APPEARS TO TRACK WELL TO OUR NORTH ONCE AGAIN, WITH A WARM FRONT LIFTING MOSTLY TO OUR NORTHWEST. WHILE THE FLOW LOOKS FAIRLY WEAK, ENOUGH WAA IS EXPECTED TO OCCUR TO ALLOW FOR FURTHER MODERATION OF THE AIRMASS WITH MANY AREAS GETTING INTO THE LOWER 50S WEDNESDAY AFTERNOON. THE COLD FRONT SHOULD BE ARRIVING LATE WEDNESDAY, HOWEVER GIVEN THE TRACK OF THE SURFACE LOW AND SHORT WAVE ALOFT IT ALSO LOOKS TO BE MOISTURE STARVED. FOR THURSDAY...A WEAK SURFACE HIGH IS ANTICIPATED TO MOVE ACROSS THE AREA, WHILE A FRONTAL BOUNDARY IS DRAPED FROM NEAR MAINE TO THE GREAT LAKES THEN INTO THE CENTRAL PLAINS. THE AIRMASS SHOULD BE MUCH MILDER WITH AFTERNOON HIGHS GETTING INTO THE 50S. THE OCEAN AND DELAWARE BAY ARE COLD AND IF THERE IS LIGHT ENOUGH FLOW, THEN A COOLING AFFECT CAN BE EXPECTED CLOSER TO THE COAST. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. LIFR AND IFR CONDITIONS WILL LIKELY BE PRESENT AT ALL TAF SITES INTO THE EVENING WITH ACCUMULATING SNOW. KRDG AND KABE WILL BE FIRST TO IMPROVE TO VFR BY 00Z 3/6. OTHER TAF SITES WILL FOLLOW WITH AN IMPROVEMENT TO VFR WITH KACY LAST AROUND 03Z. NORTHERLY WINDS BETWEEN 10 AND 15 KNOTS ARE EXPECTED AS WELL INTO THE EVENING, POTENTIALLY LASTING LONGER THAN CURRENT TAFS INDICATE. OVERNIGHT NORTH TO NORTHWEST WINDS SHOULD SLACKEN SLIGHTLY WITH CONTINUED VFR CONDITIONS ON FRIDAY. OUTLOOK... FRIDAY NIGHT THROUGH SUNDAY...VFR OVERALL. A WEAK SYSTEM MOVING BY LATER SATURDAY SHOULD RESULT IN MORE CLOUDS, HOWEVER ANY PRECIPITATION LOOKS TO STAY TO OUR NORTH AND WEST. MONDAY AND TUESDAY...VFR OVERALL. A WEAK COLD FRONT MOVING THROUGH MONDAY SHOULD RESULT IN MORE CLOUDS, HOWEVER IT APPEARS THAT IT MOVES THROUGH DRY. && .MARINE... WAVES ALONG THE COASTAL WATERS WILL CONTINUE TO REMAIN NEAR OR ABOVE 5 FT. IN ADDITION, WINDS ARE EXPECTED TO INCREASE SLIGHTLY THROUGH THE EVENING HOURS OUT OF THE NORTH NORTHWEST. THEREFORE THE SMALL CRAFT ADVISORY CONTINUES ON THE ATLANTIC COASTAL WATERS THROUGH THE OVERNIGHT HOURS. ON THE BAY, A FEW GUSTS ABOVE 20 KT ARE POSSIBLE, BUT CONDITIONS SHOULD GENERALLY STAY BELOW SMALL CRAFT ADVISORY CRITERIA. FOR FRIDAY, WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA. OUTLOOK... FRIDAY NIGHT AND SATURDAY...THE CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CRITERIA, HOWEVER THE WINDS WILL INCREASE SOME FROM THE WEST-SOUTHWEST DURING SATURDAY. THERE IS A CHC FOR SOME LIGHT FREEZING SPRAY FRIDAY NIGHT AND SATURDAY MORNING. SUNDAY THROUGH TUESDAY...WE ARE ANTICIPATING SUB SMALL CRAFT ADVISORY CONDITIONS AS A WEAK FRONT MOVES THROUGH MAINLY DURING MONDAY. && .CLIMATE... WITH A SNOW COVER IN PLACE AND ANOTHER ARCTIC AIRMASS SETTLING INTO THE REGION AND RADIATIONAL COOLING OCCURRING WE HAVE ANOTHER CHANCE FOR MORE RECORD LOWS ACROSS THE REGION. FRIDAY 3/6 RECORD LOWS ACY 10 1888 PHL 10 1978 ILG 11 1926 ABE 7 1960 TTN 7 1872 GED 10 1978 RDG 7 1978 MPO -5 1909 THE CURRENT FORECAST CURRENTLY HAS MOST LOCATIONS BREAKING THERE RECORD LOW ON FRIDAY MORNING. THE ONE EXCEPTION WOULD BE MOUNT POCONO. SATURDAY 3/7 RECORD LOWS ACY 10 1890 PHL 9 1960 ILG 11 1960 ABE 1 1960 TTN 7 1890 GED 3 1960 RDG 10 1989 MPO -18 1911 IT APPEARS THAT READING AND ATLANTIC CITY HAVE THE BETTER CHANCE OF GETTING TO THEIR RECORD LOW SATURDAY MORNING. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ060>062-070-071-101>106. NJ...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NJZ007>010-012>027. DE...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ008- 012-015-019-020. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ450>455. && $$ SYNOPSIS...GORSE NEAR TERM...GAINES SHORT TERM...GAINES LONG TERM...GORSE AVIATION...GAINES/GORSE MARINE...GORSE/JOHNSON CLIMATE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1130 AM CST THU MAR 5 2015 .SHORT TERM... 356 AM CST TODAY THROUGH FRIDAY... HIGH PRESSURE WAS CENTERED TO OUR WEST OVER THE MID-MISSOURI VALLEY EARLY THIS MORNING...AND WILL SPREAD SOUTHEAST ACROSS CENTRAL ILLINOIS THIS AFTERNOON IN THE WAKE OF A POSITIVE-TILT UPPER TROUGH PROPAGATING ACROSS THE AREA THIS MORNING. ARCTIC AIR HAS OOZED INTO THE REGION OVER THE PAST 24 HOURS...THOUGH HIGH CLOUD COVER ASSOCIATED WITH THE UPPER JET STREAK AHEAD OF THE TROUGH AXIS HAS HELPED TO KEEP READINGS FROM BOTTOMING OUT TOO HARD OVERNIGHT. 3 AM SURFACE MAP SHOWS ONLY ROCHELLE AT -1...WITH TEMPERATURES OTHERWISE IN THE POSITIVE SINGLE DIGITS ACROSS THE FORECAST AREA OUTSIDE OF A FEW LOWER TEENS IN THE CORE OF THE CHICAGO URBAN HEAT ISLAND. MAY SEE A FEW MORE SUB-ZERO TEMPS THROUGH SUNRISE ESPECIALLY ACROSS NORTH CENTRAL ILLINOIS ALONG THE NORTHWEST PERIPHERY OF THE HIGH CLOUD COVER...WITH LIGHT NORTH WINDS PRODUCING WIND CHILLS FROM -5 TO -15 F. THE HIGH CLOUDS WILL SHIFT OFF TO THE EAST TODAY WITH THE UPPER TROUGH...WITH MAINLY SUNNY SKIES EXPECTED. ONLY SHALLOW MIXING IS ANTICIPATED WITH THE NORTHERN EXTENT OF THE SURFACE HIGH PASSING ACROSS THE AREA...THOUGH STRENGTHENING MARCH SUNSHINE SHOULD HELP CHILLY MORNING TEMPERATURES RECOVER INTO THE 15-20 DEGREE RANGE BY AFTERNOON. HAVE MAINTAINED FORECAST HIGHS A FEW DEGREES ABOVE THE WARMER END OF THE GUIDANCE SPECTRUM. THE HIGH WILL SHIFT SOUTHEAST OF THE AREA TONIGHT...ALLOWING SOUTHERLY WINDS TO DEVELOP AND WARM ADVECTION TO DEVELOP ALOFT. WINDS WILL BE LIGHT INITIALLY...WHICH COMBINED WITH MAINLY CLEAR SKIES SHOULD ALLOW TEMPS TO FALL QUICKLY THIS EVENING...THEN BECOME STEADY OR SLOWLY RISE A FEW DEGREES LATER IN THE NIGHT AS THOSE SOUTH WINDS INCREASE JUST A BIT. SOUTH WINDS WILL BECOME GUSTY FRIDAY AS A MID-LEVEL WAVE AND ASSOCIATED SURFACE LOW PRESSURE PASS NORTH OF THE LAKES ACROSS ONTARIO...NEARING 25 MPH AT TIMES DURING THE DAY. WHILE TEMPERATURES MODERATE INTO THE MID 20S TO AROUND 30 ON FRIDAY...THE GUSTY WINDS WILL KEEP WIND CHILLS IN THE TEENS THROUGH THE AFTERNOON MAKING FOR A RAW FEEL TO THE DAY. RATZER && .LONG TERM... 356 AM CST SATURDAY THROUGH WEDNESDAY... THE EASTERN NORTH AMERICAN UPPER TROUGH BROADENS AND DEAMPLIFIES DURING THE PERIOD...WHILE THE PERSISTENT STRONG WEST COAST UPPER RIDGE LOSES STRENGTH. THIS WILL PROVIDE MODERATING TEMPERATURES AS LOW LEVEL FLOW BECOMES MORE PERSISTENTLY WEST-SOUTHWEST...AND NORTHWEST FLOW ALOFT BECOMES MORE ZONAL ESPECIALLY INTO NEXT WEEK. INITIALLY...A COUPLE OF SMALL AMPLITUDE SHORT WAVES WILL RIPPLE SOUTHEAST ACROSS THE GREAT LAKES REGION OVER THE WEEKEND...ONE ON SATURDAY AND ANOTHER LATER IN THE DAY SUNDAY. WEAK SURFACE COLD FRONTS WILL GLANCE THE AREA WITH THESE TWO DISTURBANCES...TEMPERING THE WARM-UP JUST A BIT. STILL...WITH WARMING ALOFT AND SOUTH-SOUTHWEST FLOW AT THE SURFACE AHEAD OF EACH OF THESE WEAK FRONTS TEMPS SHOULD REACH THE 35-40 DEGREE RANGE BOTH SATURDAY AND SUNDAY. SOME OF THE ENSEMBLE GUIDANCE TRIES TO PAINT A LITTLE LIGHT PRECIPITATION AHEAD OF THESE BOUNDARIES AS WELL...THOUGH FORECAST TIME/HEIGHT SECTIONS AND SOUNDINGS SHOW A LACK OF DEEP MOISTURE AND IT APPEARS THAT THE THREAT OF ANY MORE SIGNIFICANT PRECIPITATION WILL REMAIN NORTH OF THE CWA. MORE ROBUST WARMING LOOMS JUST PAST THE WEEKEND AS UPPER FLOW BECOMES MORE ZONAL...AND ANOTHER DEEPER LOW MOVES EAST ACROSS CANADA. ECMWF WARMS OUR 850 MB TEMPS TO +2 C BY TUESDAY AND TO +6 C BY WEDNESDAY...WITH BOTH GFS/ECMWF GUIDANCE BOOSTING SFC TEMPS INTO THE LOW-MID 40S TO START THE WEEK...AND INTO THE 50-55 DEGREE RANGE TUESDAY AND WEDNESDAY. SURFACE HIGH PRESSURE RIDGE REMAINS TO OUR SOUTH FROM TEXAS TO SOUTHERN NEW ENGLAND DURING THE PERIOD... MINIMIZING THE RETURN OF DEEP MOISTURE AND KEEPING PRECIPITATION CHANCES LOW THROUGH THE EXTENDED. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NWLY WINDS OCNLLY GUSTING TO 18-20 KT THIS AFTERNOON. KREIN //DISCUSSION...UPDATED 18Z... HIGH PRESSURE IS CENTERED OVER THE MIDDLE MISSISSIPPI VALLEY WILL CONTINUE TO SAG SOUTHEAST TO THE OHIO VALLEY BY THIS EVENING. NWLY WINDS OCNL GUSTING TO 18-20KT WILL SLOWLY BACK TO WLY THIS EVENING WHILE DIMINISHING TO 5-7KT. AS THE HIGH CONTINUES TO SAG TO THE UPPER OHIO VALLEY TO LOWER MISSISSIPPI VALLEY TOMORROW AS WEAK TROUGHING DEVELOPS OVER THE NRN PLAINS. WINDS WILL THE BECOME SWLY TOMORROW...BUT WITH A STRENGTHENING PRESSURE GRADIENT AND AMPLE SUNSHINE FOR DEEP LAYER MIXING...GUSTING TO 20-25KT IS EXPECTED FROM LATE MORNING THROUGH THE AFTERNOON. VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS HIGH PRESSURE REMAINS THE DOMINANT FEATURE OVER THE REGION. KREIN //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM-HIGH CONFIDENCE IN WIND TRENDS. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT THROUGH WEDNESDAY...PRIMARILY VFR. BMD && .MARINE... 318 AM CST HIGH PRESSURE IS OVER THE UPPER MIDWEST EARLY THIS MORNING AND WILL DRIFT ACROSS THE OHIO VALLEY THIS EVENING...THEN SETTLE ACROSS THE SOUTHEASTERN STATES THROUGH THE WEEKEND. AS THE HIGH DRIFTS ACROSS THE MIDWEST...WINDS WILL BACK TO THE WEST THIS EVENING...THEN SOUTHWEST TONIGHT. A SERIES OF LOWS WILL MOVE ACROSS ONTARIO AND THE NORTHERN LAKES REGION THIS WEEKEND AND EARLY NEXT WEEK. WINDS WILL GENERALLY STAY OUT OF THE WEST AND SOUTHWEST THROUGH THIS PERIOD...FRESHENING UP AT TIMES IN ADVANCE OF THE LOWS. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1059 AM CST Thu Mar 5 2015 .UPDATE... ISSUED AT 1059 AM CST THU MAR 5 2015 Made some minor adjustments to the forecast in central and southeast Illinois for sky cover today and to lower the overnight lows in eastern IL. High pressure centered near Des Moines, IA late this morning will continue to slowly push eastward resulting in decreasing west winds and unseasonably cold temperatures today and tonight. A few records may be set today for coldest high temperatures on this date, and we cold get close to some record lows in eastern IL overnight. Lowered the temperatures to below zero readings in all areas east of I-57 due to the extensive snow cover and the expectation of a clear sky and very light wind overnight. In central and west central IL, lowered the overnight temps a bit early, but an increasing southerly wind should result in steady or even slowly rising temperatures toward daybreak from Peoria- Springfield and locations to the west. The high resolution models such as the HRRR, NAM12 and to a lesser extent the RAP, continue to indicate rapidly increasing low level cloudiness this afternoon. These models have done this a lot lately with very few clouds actually developing. Thus, am anticipating some scattered cloud cover and generally mostly sunny conditions in all of central and southeast IL this afternoon. && .SHORT TERM...(Today) ISSUED AT 254 AM CST THU MAR 5 2015 The storm system that brought snow to southeast Illinois yesterday and last evening was finally starting to shift away from our forecast area early this morning. At the surface, high pressure tracking southeast across northwest Iowa will drift across our area today bringing another 24 hours of unseasonably cold weather with afternoon highs struggling through the teens over most of the forecast area, which is about 30 degrees below where it should be for the first week in March. As the large fair weather system drifts closer to central Illinois today, the wind this afternoon will not be as gusty as what we saw yesterday. However, this morning, that will be a different story, as the pressure gradient will be tight enough for a few more hours to produce just enough wind to drop wind chills down to between -10 to -15 mainly north of I-74 for a few hours early this morning. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 254 AM CST THU MAR 5 2015 Pretty tranquil weather through the period, with no precipitation chances in the forecast into the middle of next week. Periodic upper waves will zip through the area in the northern jet stream, but moisture levels will be meager and little more than wind shifts are expected in our area. The longer range models are in general agreement with this pattern into mid week. The main highlight will be the welcome trend toward milder weather. The long wave trough from Lake Superior to New Mexico evident on early morning water vapor imagery will move through the Midwest later today. Lows in the single digits are still expected tonight, but the coldest temperatures will be this evening, with steady or rising temperatures overnight after surface high pressure settles into the Ohio Valley. However, wind chills well below zero are on tap, as low as 10 below in areas from Bloomington to Danville. After that, nice southwest flow should get much of the western half of the forecast area above freezing on Friday. Temperatures will continue to warm into next week, with most areas well into the 50s by Tuesday. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) ISSUED AT 515 AM CST THU MAR 5 2015 VFR conditions are expected to prevail through tonight. High pressure to our northwest will shift over the region today bringing a lighter wind flow and less in the way of cloud cover compared to yesterday. Currently have a band of cirrus streaming northeast across the area this morning but the latest HRRR forecasts indicate those should be to our east by mid-morning. Surface winds today will be from the northwest at 8 to 15 kts and then become light and variable by 00z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Miller SHORT TERM...Smith LONG TERM...Geelhart AVIATION...Smith
AREA FORECAST DISCUSSION
NWS JACKSON MS
427 PM CST THU MAR 5 2015 .DISCUSSION... THE WINTER STORM THAT AFFECTED THE ARKLAMISS LATE LAST NIGHT AND MUCH OF TODAY IS OVER AND ALL ADVISORIES/WARNINGS HAVE ENDED. THERE ARE A FEW REPORTS OF SLEET IN THE PINEBELT REGION BUT TEMPERATURES HAVE STAYED ABOVE FREEZING AND NO TRAVEL ISSUES ARE ANTICIPATED THERE AS THE PRECIPITATION ENDS LATE THIS AFTERNOON. IN AREAS THAT RECEIVED HEAVIER ICE/SLEET...WE HAVE BEEN CONCERNED ABOUT ISSUES WITH REFREEZING FOR TONIGHT GIVEN THAT TEMPERATURES ARE EXPECTED TO FALL WELL INTO THE 20S AND TEENS. SKIES HAVE CLEARED OVER MOST OF THE AREA AND THIS IS ALLOWING TEMPERATURES TO RISE ABOVE FREEZING AS DRY NORTHERLY WINDS HELP TO DRY OFF THE ROADS. WHILE REFREEZING MAY OCCUR IN SOME LOCATIONS...IT IS NOT QUITE AS BIG OF A CONCERN AS IT WAS EARLIER...ESPECIALLY ON THE WELL-TRAVELED ROADS. ONCE THE PRECIPITATION ENDS...DRY CONDITIONS ARE THEN FORECAST THROUGH SATURDAY NIGHT WITH THE BIGGEST CHALLENGE BEING TEMPERATURES AS COLD HIGH PRESSURE BECOMES CENTERED OVER THE AREA. SOME OF THE GUIDANCE IS OVER-DOING COOLING ASSOCIATED WITH ICE COVER TONIGHT AND THIS IS MAKING FOR A LOW-CONFIDENCE TEMPERATURE FORECAST. DID NOT WANT TO GO NEARLY AS LOW AS HRRR WHICH HAS SINGLE DIGIT READINGS IN QUITE A FEW LOCATIONS...BUT DO BELIEVE TEENS WILL BE COMMON PARTICULARLY OVER NORTHERN PORTIONS OF THE ARKLAMISS DELTA REGION WHERE BOUNDARY LAYER DECOUPLING IS MORE LIKELY TO OCCUR. EXPECT MODERATING TEMPERATURES FOR TOMORROW...BUT HIGHS WILL STILL BE WELL BELOW CLIMATOLOGICAL NORMALS. HIGH PRESSURE WILL BE CENTERED OVER THE FORECAST AREA FRIDAY NIGHT AND THIS WILL PROMOTE EXCELLENT NIGHTTIME COOLING CONDITIONS WITH MOSTLY CLEAR SKIES AND LIGHT WIND. HAVE CUT CONSENSUS MODEL BLEND LOW TEMPERATURES A BIT BUT NOT TOO MUCH AS THERE COULD BE A BIT OF CIRRUS THAT DISRUPTS COOLING. /EC/ SUNDAY THROUGH THURSDAY...A WETTER PATTERN LOOKS TO TAKE SHAPE AS WE GO INTO NEXT WEEK. CLOUDS WILL INCREASE OVER THE WEEKEND AS THE SOUTHERN STREAM UPPER JET BECOMES MORE ACTIVE WITH A SERIES OF SHORTWAVES THAT WILL MOVE THROUGH THE REGION DURING THE PERIOD. THE EURO..GFS...AND GEM MODELS HAD SOME DIFFERENCES WITH AREA PRECIP COVERAGE ASSOCIATED WITH THE SHORT WAVES. THE FIRST ONE WILL BRING SOME RAIN TO THE REGION FOR SATURDAY NIGHT INTO MONDAY. A LITTLE STRONGER SHORT WAVE WILL BRING MORE RAIN TO THE REGION FOR TUESDAY THROUGH THURSDAY. THIS ACTIVE PATTERN WILL CONTINUE OVER THE REGION INTO NEXT WEEKEND. EXPECT A WARMING TREND FOR THE UPCOMING WORK WEEK. AS HIGHS GOES FROM THE 50S TO THE 60S. THIS WILL BRING AFTERNOON HIGHS CLOSER TO NORMAL FOR THIS TIME OF THE YEAR. BY THE TIME WE GET TO THURSDAY IT WILL BE SPRING LIKE WITH HIGHS PUSHING TOWARD THE 70 DEGREE MARK IN THE SOUTH. LOWS WILL GRADUALLY RISE TO THE 50S BY WEDNESDAY NIGHT. /17/ && .AVIATION... SKIES ARE RAPIDLY CLEARING FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA THIS AFTERNOON. MVFR FLIGHT STATUSES WILL EXIST AT SITES WHERE CLOUDS ARE OBSERVED. SKIES WILL CONTINUE TO CLEAR THIS EVENING...AND VFR STATUSES ARE EXPECTED TO PREVAIL TONIGHT INTO FRIDAY MORNING. TONIGHT AND FRIDAY MORNING...WITH LOWS FALLING INTO THE TEENS AND 20S...ANY RESIDUAL OR STANDING WATER ON AIRCRAFT... RUNWAYS...TARMACS...AND RAMPS WILL FREEZE. WINDS WILL REMAIN NORTHERLY OVERNIGHT...BUT WILL SUBSIDE A BIT AND GENERALLY RANGE BETWEEN 7-10 KNOTS. /19/ .PRELIMINARY POINT TEMPS/POPS... JACKSON 21 44 25 58 / 0 0 0 6 MERIDIAN 21 46 21 59 / 2 0 0 5 VICKSBURG 20 44 23 55 / 0 0 0 6 HATTIESBURG 24 51 25 63 / 9 0 0 7 NATCHEZ 21 44 24 58 / 0 0 0 8 GREENVILLE 18 38 23 51 / 0 0 0 4 GREENWOOD 17 41 21 54 / 0 0 0 4 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ EC/17/19/
AREA FORECAST DISCUSSION
NWS JACKSON MS
1019 AM CST THU MAR 5 2015 .UPDATE... INFRARED SATELLITE DATA SHOW INFLECTION WITH APPROACHING SHORTWAVE TROUGH NOW MOVING INTO WRN LA. EXTRAPOLATION TAKES IT TO THE MS/ALABAMA BORDER BY AROUND 21Z. LIFT ASSOCIATED WITH THE TROUGH IS ENHANCING PRECIPITATION ALONG THE BAROCLINIC ZONE FROM CENTRAL/NE LA ACROSS SW/CENTRAL/NE PORTIONS OF MS. THIS IS OCCURRING AS COLD ADVECTION HAS PUSHED THE FREEZING LINE SOUTHEAST TO A BROOKHAVEN TO FOREST TO PHILADELPHIA TO MACON LINE. RECENT HRRR GUIDANCE IS HANDLING SITUATION WELL AND SUGGESTS THE FREEZING LINE WILL PUSH A LITTLE FARTHER SOUTHEAST AS WE GO THROUGH THE LATE MORNING BEFORE STABILIZING THIS AFTERNOON. IT HAS HEAVIER QPF LATE THIS MORNING WITH LIGHTER PRECIPITATION LINGERING THROUGH EARLY TO MID AFTERNOON...DIMINISHING AS THE PREVIOUSLY MENTIONED WAVE PASSES ACROSS AND MUCH DRIER AIR SURGES IN. THE PRECIPITATION TYPE HAS BEEN A BIG CHALLENGE WITH A BIG MID LEVEL WARM NOSE IN THE 12Z KJAN SOUNDING (+11 DEG C) THAT BROUGHT COMPLETE MELTING...ABOVE A SUBSTANTIAL COLD LAYER (-4.5 AND ~4000 FT DEEP) WHICH APPARENTLY WAS ENOUGH FOR COMPLETE REFREEZING AS SLEET FELL AT ABOUT THE TIME OF THE RAOB. SINCE THEN...THE FREEZING RAIN HAS MOSTLY TRANSITIONED TO MDT/HEAVY SLEET OVER MOST OF THE AREA NW OF THE FREEZING LINE. WE ASSUME THERE IS STILL A NARROW ZONE OF FREEZING RAIN...BUT THIS SEEMS TO BE LESS OF AN ISSUE NOW. THE CURRENT WINTER WEATHER WARNING/ADVISORY ALIGNMENT IS STILL OK BUT WILL KEEP A CLOSE EYE ON FURTHER PROGRESSION OF THE FREEZING LINE AS PRECIP IS FORECAST TO LINGER OVER THE PINE BELT REGION THROUGH LATE AFTERNOON. LATEST SREF GUIDANCE KEEPS FREEZING RAIN PROBS JUST NW OF THE HATTIESBURG AREA...AND THE SREF HAS PERFORMED WELL HAVING HIT SLEET PROBS HARD SEVERAL DAYS AGO. WILL MAKE UPDATES TO THE NEAR TERM FORECAST BASED ON THE LATEST HRRR GUIDANCE...MAINLY TO ADJUST TEMPERATURES AND ADD SOME PRECIP INTO THE LATE AFTN OVER THE SE. WILL ALSO PLACE MORE EMPHASIS ON SLEET WITH A CHANGEOVER TO LIGHT SNOW AS THE ATMOSPHERIC COLUMN COOLS FURTHER OVER NW PORTIONS OF THE ARKLAMISS. /EC/ .AVIATION...MVFR FLIGHT CATEGORIES CONTINUE TO BE OBSERVED AT TAF SITES ACROSS THE AREA THIS MORNING AS A RESULT OF LOW CEILINGS HEIGHTS. A MIX BAG OF PRECIPITATION...MAINLY THAT IN THE FORM OF A SLEET AND LIGHT SNOW MIX...IS ALSO BEING OBSERVED AT NAMELY KHKS...KJAN...AND KGTR. AT KGLH AND KGWO...PRECIPITATION IS COMING TO AN END. THERE WILL BE A BRIEF WINDOW AT KMEI...FROM 17Z-20Z TODAY...OF A LIGHT FREEZING RAIN AND SLEET MIX...BUT LITTLE ACCUMULATION IS EXPECTED. PRECIPITATION TYPE AT KHBG WILL REMAIN RAIN AS TEMPERATURES HOVER IN THE UPPER 30S. ANY SITES THAT INDEED EXPERIENCE ANY WINTRY PRECIPITATION COULD SEE A LIGHT ICING ON AIRCRAFT AND OTHER METAL AND ELEVATED SURFACES. AGAIN...THIS IS AND/OR WILL BE THE CASE AT ALL SITES EXCEPT KHBG WHERE FROZEN PRECIPITATION IS NOT EXPECTED. THIS ACTIVITY IS CURRENTLY EXPECTED TO COME TO AND END BY 21Z THIS AFTERNOON. HOWEVER TONIGHT AND FRIDAY MORNING...WITH LOWS FALLING INTO THE TEENS AND 20S...ANY RESIDUAL OR STANDING WATER ON AIRCRAFT... RUNWAYS...TARMACS...AND RAMPS WILL FREEZE. WINDS TODAY WILL BE BREEZY FROM THE NORTH AROUND 15 KNOTS...GUSTING AT TIMES AROUND 25 KNOTS. WINDS WILL REMAIN NORTHERLY OVERNIGHT... BUT WILL SUBSIDE A BIT AND RANGE BETWEEN 7-10 KNOTS. /19/ && .PREV DISCUSSION... /ISSUED 439 AM CST THU MAR 5 2015/ WINTER STORM ONGOING FOR PORTIONS OF THE REGION... SHORT TERM...TODAY THROUGH FRIDAY NIGHT...AT 4 AM THE FREEZING LINE AT THE SURFACE HAS SUNK DOWN TO JUST NORTHWEST OF THE NATCHEZ TRACE CORRIDOR AND THIS FREEZING LINE WILL CONTINUE TO STEADILY ADVANCE SOUTHEAST THROUGH THE REMAINDER OF THE MORNING HOURS. ALOFT THE MEAT OF THE UPPER LEVEL TROUGH IS STARTING TO SWING INTO THE LOWER MS VALLEY PRESENTLY WITH AN IMPRESSIVE RIGHT ENTRANCE REGION OF A SCREAMING HIGH LEVEL JET STREAK HELPING TO FOCUS LIFT IN OUR REGION. PRECIPITATION HAS A SOMEWHAT CONVECTIVE LOOK RIGHT NOW ACROSS THE NORTHWEST TWO-THIRDS OF THE REGION WITH AREAS NORTHWEST OF THE NATCHEZ TRACE REPORTING MOSTLY SLEET. A FOCUSED BAND OF MODERATE TO HEAVY PRECIP IS SETTING UP BACK TO OUR SOUTHWEST AND LOOKS TO MOVE ACROSS THE NATCHEZ TRACE CORRIDOR OVER THE NEXT 2-4 HOURS. SOME THUNDER OCCURRING IN THIS PRECIP BAND (AND EVEN ELSEWHERE) GIVES CONFIDENCE OF LOCALLY HEAVY PRECIP WHICH WILL BE MOSTLY WINTRY CONSIDERING DROPPING TEMPS. TAKING MESOSCALE EVOLUTIONS INTO ACCOUNT WE HAVE DECIDED TO EXPAND THE WINTER STORM WARNING A BIT FURTHER INTO THE HEART OF CENTRAL MS AND EXPAND THE WINTER WX ADVISORY A BIT FURTHER INTO SOUTH CENTRAL MS. WE WILL TAKE A LAST LOOK AT THINGS BEFORE DAYBREAK AND MAKE MINOR ADJUSTMENTS TO WARNINGS AND ADVISORIES IF NECESSARY. ONE THING TO POINT OUT IS THAT WHILE SLEET HAS BEEN RATHER UBIQUITOUS SO FAR THIS MORNING IN THE NORTHWESTERN PORTION OF THE REGION THE POTENTIAL FOR FREEZING RAIN WILL INCREASE TOWARD THE HEART OF FORECAST AREA OWING TO SLIGHTLY WARMER TEMPERATURES ALOFT. THAT SAID...MOST AREAS OUTSIDE OF FAR SOUTHEASTERN MS SHOULD SEE SOME OF COMBINATION OF SLEET AND FREEZING RAIN THIS MORNING WITH MORE SLEET NORTH OF I-20 AND MORE FREEZING RAIN SOUTH OF I-20. PRECIPITATION REALLY LOOKS TO BE TAPERING OFF PRETTY QUICKLY FROM LATE MORNING THROUGH EARLY AFTERNOON AND IT IS POSSIBLE PORTIONS OF THE ADVISORY AND WARNING IN EFFECT THROUGH 3 PM MAY BE ABLE TO BE CANCELLED EARLY. DESPITE ENDING PRECIP LATER TODAY THE ONLY CHANCE AT SUN SHOULD BE IN THE EXTREME NORTHWEST ARKLAMISS DELTA ZONES WITH TEMPERATURES THIS AFTERNOON STRUGGLING TO GET OUT OF THE LOW TO MID 30S IN MOST AREAS. CLEARING SKIES TONIGHT WILL SET THE STAGE FOR DECENT RAD COOLING LATE TONIGHT AFTER TODAYS STRONG NORTH WINDS GRADUALLY DIE DOWN. REMAINING ICE PACK IN NORTHWESTERN ZONES WILL HELP WITH COOLING AND ALLOW FOR LOWS IN THE TEENS IN NORTHWESTERN ZONES AND WELL DOWN IN THE 20S MOST OTHER AREAS. SOME RECORD LOWS WILL LIKELY FALL. STILL LOOKS LIKE WIND CHILLS IN THE SINGLE DIGITS WILL BE POSSIBLE IN THE ARKLAMISS DELTA TONIGHT AND THE COMING DAY SHIFT WILL HAVE TO CONSIDER ISSUING A WIND CHILL ADVISORY. FRIDAY WILL FEATURE LOTS OF SUN AND SOMEWHAT WARMER TEMPERATURES...BUT HIGHS WILL REMAIN WAY BELOW NORMAL WITH MODIFYING ARCTIC HIGH PRESSURE PARKED RIGHT OVERHEAD. THIS HIGH PRESSURE RIDGE WILL BE SITUATION TO BRING RATHER PERFECT RAD COOLING CONDITIONS AFTER SUNDOWN WITH PLUMMETING TEMPS AND LOWS ONCE AGAIN WAY BELOW NORMAL. /BB/ LONG TERM...SATURDAY THROUGH THURSDAY...FOR THE WEEKEND SURFACE HIGH PRESSURE WILL BE OVER THE REGION ON SATURDAY WHILE THE UPPER FLOW BECOMES WEST SOUTHWESTERLY. DAILY HIGHS IN THE WEEKEND WILL PUSH INTO MAINLY THE 50S. CLOUDS WILL INCREASE OVER THE WEEKEND AS THE SOUTHERN STREAM UPPER JET BECOMES MORE ACTIVE WITH A SERIES OF SHORTWAVES THAT WILL MOVE THROUGH THE REGION DURING THE PERIOD. THE EURO..GFS...AND GEM MODELS HAD SOME DIFFERENCES WITH AREA PRECIP COVERAGE ASSOCIATED WITH THE SHORT WAVES. THE FIRST ONE WILL BRING SOME RAIN TO THE REGION FOR SATURDAY NIGHT INTO MONDAY. A LITTLE STRONGER SHORT WAVE WILL BRING MORE RAIN TO THE REGION FOR TUESDAY THROUGH THURSDAY. THIS ACTIVE PATTERN WILL CONTINUE OVER THE REGION INTO NEXT WEEKEND. EXPECT A WARMING TREND FOR THE UPCOMING WORK WEEK. AS HIGHS GOES FROM THE 50S TO THE 60S. THIS WILL BRING AFTERNOON HIGHS CLOSER TO NORMAL FOR THIS TIME OF THE YEAR. BY THE TIME WE GET TO THURSDAY IT WILL BE SPRING LIKE WITH HIGHS PUSHING TOWARD THE 70 DEGREE MARK IN THE SOUTH. LOWS WILL GRADUALLY RISE TO THE 50S BY WEDNESDAY NIGHT. /17/ && .JAN WATCHES/WARNINGS/ADVISORIES... MS...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR MSZ039- 045-046-049>051-054-055-059>062. WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR MSZ029>033-036>038-042>044-047-048-053. WINTER STORM WARNING UNTIL NOON CST TODAY FOR MSZ018-019-025>028- 034-035-040-041. LA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR LAZ024- 026. WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR LAZ016- 023-025. WINTER STORM WARNING UNTIL NOON CST TODAY FOR LAZ007>009-015. AR...WINTER STORM WARNING UNTIL NOON CST TODAY FOR ARZ074-075. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1115 AM CST THU MAR 5 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST THU MAR 5 2015 QUIET CONDITIONS REIGN ACROSS THE REGION EARLY THIS MORNING WITH MOSTLY CLEAR SKIES.THE CWA SITS IN BETWEEN UPPER LEVEL DISTURBANCES IN NORTHWESTERLY FLOW...ONE BEING THE TROUGH AXIS EXTENDING FROM ROUGHLY THE HUDSON BAY SOUTHWARD INTO THE SRN PLAINS...AND THE OTHER A WEAKER SHORTWAVE DISTURBANCE NOW WORKING ITS WAY INTO NERN MONTANA. AT THE SURFACE...HIGH PRESSURE REMAINS THE DOMINANT FEATURE...AND IS CURRENTLY CENTERED OVER ERN PORTION OF NEB/SD. WINDS ACROSS MUCH OF THE CWA REMAIN ON THE LIGHT/VARIABLE SIDE...AND TEMPS AS OF 3 AM RANGE FROM RIGHT AROUND THE 0 DEGREE MARK IN THE N/NE TO THE LOWER TEENS FURTHER SOUTH. THROUGH THE SHORT TERM PERIOD OF TODAY AND TONIGHT...WILL CONTINUE TO SEE NORTHWESTERLY FLOW SET UP IN THE UPPER LEVEL WITH THAT MAIN TROUGH AXIS PUSHING FURTHER EAST AND RIDGING IN PLACE OVER THE WEST COAST...AND WHILE MODELS SHOW THAT WEAK DISTURBANCE CURRENTLY OVER NERN MONTANA SLIDING THROUGH THE REGION LATER TODAY/THIS EVENING...THERE IS GOOD SUPPORT WITH KEEPING THE FORECAST DRY. AT THE SURFACE...THAT ARE OF HIGH PRESSURE CURRENTLY KEEPING OUR WINDS LIGHT WILL SLIDE OFF TO THE E/SE WITH TIME...WHILE A TROUGH OF LOW PRESSURE SETS UP ACROSS THE HIGH PLAINS. AS A RESULT THE WINDS WILL TURN MORE SRLY WITH TIME...A BIT MORE SWRLY ACROSS OUR FAR WRN COUNTIES. THOUGH THAT WEAK DISTURBANCE MOVING THROUGH LATER ON WONT BE BRINGING ANY PRECIPITATION TO THE CWA...IT WILL BE PUSHING A TROUGH AXIS THROUGH...TURNING WINDS MORE WESTERLY BY SUNRISE TOMORROW. MODELS ARE IN GOOD AGREEMENT SHOWING A MODERATING AIR MASS BUILDING INTO THE REGION FROM THE WEST...AND WITH THOSE MORE SRLY/EVENTUALLY WRLY WINDS...WILL BRING A WELCOME RISE IN TEMPERATURES BOTH TODAY AND TONIGHT. WENT CLOSER TO THE RAP FOR HIGHS TODAY...WHICH WAS A BUMP UP FOR MUCH OF THE AREA BUT NOT A HUGE CHANGE...WITH MID 30S IN THE EAST TO UPPER 40S IN THE WEST FOR FORECAST HIGHS TODAY. OVERNIGHT LOWS TONIGHT WILL BE MORE MILD COMPARED TO CURRENT TEMPS...WITH LOW/MID 20S IN THE FORECAST. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 353 AM CST THU MAR 5 2015 MUCH WARMER AIR WITH DRY CONDITIONS WILL BE THE BIG STORY LINE THIS WEEKEND INTO AT LEAST THE MIDDLE OF NEXT WEEK. WE WILL TRANSITION INTO MORE OF A SPLIT FLOW PATTERN WITH THE COLD ARCTIC AIR BOTTLED UP OVER CANADA...AND FAIRLY PROGRESSIVE FLOW OF PACIFIC ORIGIN ACROSS MUCH OF THE CONUS. MOST DAYS THE SFC WIND WILL HAVE SOMEWHAT OF A DOWNSLOPING WESTERLY COMPONENT AND AN ELEVATED MIXED LAYER OFF THE ROCKIES WILL KEEP TEMPERATURES ALOFT FAIRLY WARM. THIS ALL POINTS TO WARM SFC TEMPERATURES THAT WILL BE ABOVE NORMAL...TO EVEN WELL ABOVE NORMAL FOR THIS TIME OF YEAR...WHICH WILL BE A WELCOMED CHANGE AFTER OUR RECENT COLD SNAP. DESPITE NORMAL HIGHS ONLY BEING IN THE MID 40S...WE EXPECT TO SEE HIGHS THE NEXT FEW DAYS GENERALLY RANGING FROM THE MID 50S TO THE MID 60S. CONFIDENCE IS HIGH IN DRY WEATHER WITH GOOD MODEL AGREEMENT POINTING TOWARDS DRY CONDITIONS. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1110 AM CST THU MAR 5 2015 QUIET WEATHER IS FORECAST THRU THE TAF PERIOD WITH VFR CONDITIONS. WINDS ARE SOUTHERLY ACROSS THE TERMINALS THIS AFTN IN BETWEEN A DEPARTING SURFACE HIGH TO THE EAST AND A LOW PRESSURE TROUGH TO THE WEST. AS THE SFC TROUGH MOVES EAST TONIGHT...WINDS WILL TRANSITION WESTERLY. CLOUDS WILL BE LIMITED TO HIGH LEVELS...WITH SCATTERED CIRRUS EXPECTED TONIGHT WITH A PASSING JET STREAK. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...WESELY AVIATION...FAY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
347 PM EST THU MAR 5 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA BY LATER TODAY AND THIS EVENING. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 330PM UPDATE...EXTENDED THE WINTER STORM WARNING UNTIL 7PM EST FOR THE LOWER SQV ZONES. NO OTHER CHANGES ATTM. 100PM...HAVE CANCELED PART OF THE WEATHER ADVISORY...OTHERWISE THE NEAR TERM FORECAST HAS NOT CHANGED. AS OF MID DAY THE MOST INTENSE MESOSCALE SNOW BAND EXTENDS FROM FRANKLIN COUNTY THROUGH LEBANON COUNTY. MORE OR LESS ON TRACK WITH RAP PLACEMENT AND TIMING OF BEST FRONTOGENTIC FORCING. HRRR SHOWS THE SNOW GRADUALLY SETTLING SOUTHEAST OVER THE NEXT 2-4 HOURS...WITH A RAPID TAPERING OFF AFTER 21Z. THIS SUPPORTS FINAL SNOW TALLIES IN THE 6-10 INCH RANGE ON AVERAGE. DRIER AIR AND HIGH PRESSURE WILL BUILD IN FOR THE OVERNIGHT LEADING TO YET ANOTHER NIGHT OF WIDESPREAD LOWS OF ZERO OR BELOW. AT THIS POINT...WE ARE COUNTING ON THE WIND TO DROP OFF ENOUGH TO MINIMIZE WIND CHILLS... SO NO HEADLINES ARE PLANNED AT THIS TIME. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... HIGH PRESSURE WILL PROVIDE A MUCH BRIGHTER DAY FRIDAY. FORECAST SOUNDINGS SUGGEST THE POTENTIAL FOR SOME STRATOCU TO GATHER UNDER THE STRONG SUBSIDENCE INVERSION...BUT A FAIR AMOUNT OF SUNSHINE SHOULD MANAGE TO MIX WITH ANY CLOUDS THAT FORM. ONCE AGAIN IT WILL BE MUCH COLDER THAN NORMAL WITH HIGHS GENERALLY IN THE 20S. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... SFC HIGH PRESSURE RIDGE AXIS WILL MIGRATE EWD ACROSS THE MID ATLANTIC REGION FRIDAY NIGHT AND SETTLE INTO THE SOUTHEAST STATES ON SATURDAY. AN INCREASE IN SW GRADIENT WINDS AND CLOUDS ARE EXPECTED ACROSS THE NW HALF OF THE CWA IN ADVANCE OF A WEAK LOW MOVING ACROSS THE GREAT LAKES. MEANWHILE MAINLY CLEAR SKIES AND LIGHTER WINDS ACROSS THE LOWER SUSQ VALLEY SHOULD PREVAIL NEAR THE DEPARTING SFC RIDGE. THIS PATTERN FAVORS A NON-DIURNAL TREND WITH LOWS IN THE MID TEENS OCCURRING EARLY ACROSS THE NW MTNS FRIDAY NIGHT WITH A STEADY TO SLOW RISE INTO SATURDAY MORNING. A MORE TYPICAL NOCTURNAL TEMP CURVE SHOULD ALLOW TEMPS TO FALL TO AROUND 10F OVER THE LOWER SQV. BROAD UPPER CYCLONIC FLOW WILL CONTINUE INTO EARLY NEXT WEEK AS ADDITIONAL SHORTWAVE IMPULSES MOVE FROM CENTRAL CANADA THROUGH THE NORTHERN TIER OF THE U.S. THERE ARE FEWER DIFFERENCES NOTED OVERALL COMPARED TO PREVIOUS MODEL CYCLES WITH RESPECT TO THE TIMING AND DEPTH OF EACH IMPULSE. ONE IMPULSE WILL DRIVE A SURFACE WAVE AND ASSOCIATED FRONT THROUGH THE GREAT LAKES REGION ON SAT AND THEN INTO NEW ENGLAND ON SUN. AN ADDITIONAL IMPULSE WILL TAKE A SIMILAR TRACK THROUGH THE GREAT LAKES LATER SUN INTO EARLY MON ALONG WITH A WEAK FRONT. GIVEN THE FAST DEEPER LAYER WEST NORTHWEST FLOW OVER THE REGION...THE AMPLITUDE OF EACH IMPULSE SHOULD BE RATHER SMALL WITH MOISTURE AVAILABILITY QUITE LIMITED. THEREFORE EXPECT OCCASIONAL SNOW SHOWERS MAINLY OVER THE HIGHER TERRAIN OF THE NORTHERN ALLEGHENIES WITH 48 ACCUMS OF 1-2" POSSIBLE OVER THE NW MTNS BY 12Z MON. THE MODELS AND ENSEMBLE MEANS ARE AGREEABLE/CONSISTENT WITH THE MAIN THEMES OF THE LARGE SCALE PATTERN INTO NEXT WEEK. THESE INCLUDE AN INCREASINGLY ZONAL/PROGRESSIVE NRN STREAM FLOW ACROSS SRN CANADA...AND SRN ROCKIES/PLAINS INTO MEXICO MEAN TROUGH AND STRONG RIDGE E OF THE BAHAMAS. AS THE MEAN PATTERN ALOFT BECOMES INCREASINGLY FLATTER...CONFIDENCE IS RELATIVELY HIGH IN A MAINLY DRY PERIOD WITH STEADILY INCREASING/MODERATING TEMPERATURES TO AT OR SLIGHTLY ABOVE EARLY-MID MARCH CLIMATE NORMALS. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... MOST OF THE FLYING AREA WILL REMAIN VFR NORTH OF THE BANDED PRECIPITATION THAT IS CAUSING MVFR-IFR/LIFR FROM JOHNSTOWN EAST THROUGH THE LOWER SUSQ VALLEY. CONDITIONS WILL SLOWLY IMPROVE OVER SOUTHERN AND SOUTHEASTERN AREAS THIS AFTERNOON...WITH LANCASTER-HARRISBURG LIKELY BEING THE LAST TO ENJOY IN THE IMPROVING CONDITIONS. EXPECT MOST TERMINALS TO BE VFR OVERNIGHT. JST MAY BE THE EXCEPTION WITH LOW CLOUDS HANGING IN TOUGH UNDER THE UPSLOPE FLOW. OUTLOOK... FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. TUE...NO SIG WX. && .CLIMATE... DAILY RECORD LOWS ARE IN SERIOUS JEOPARDY TONIGHT AT MANY LOCATIONS. THE RECORD LOW FOR MARCH 6TH AT HARRISBURG IS 7F SET BACK IN 1901 AND -1F AT WILLIAMSPORT SET IN 1978. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ058. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ033>035. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ036- 057-059-063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...FITZGERALD/LA CORTE SHORT TERM...LA CORTE LONG TERM...STEINBUGL AVIATION...LA CORTE CLIMATE...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
343 PM EST THU MAR 5 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA BY LATER TODAY AND THIS EVENING. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... HAVE CANCELED PART OF THE WEATHER ADVISORY...OTHERWISE THE NEAR TERM FORECAST HAS NOT CHANGED. AS OF MID DAY THE MOST INTENSE MESOSCALE SNOW BAND EXTENDS FROM FRANKLIN COUNTY THROUGH LEBANON COUNTY. MORE OR LESS ON TRACK WITH RAP PLACEMENT AND TIMING OF BEST FRONTOGENTIC FORCING. HRRR SHOWS THE SNOW GRADUALLY SETTLING SOUTHEAST OVER THE NEXT 2-4 HOURS...WITH A RAPID TAPERING OFF AFTER 21Z. THIS SUPPORTS FINAL SNOW TALLIES IN THE 6-10 INCH RANGE ON AVERAGE. DRIER AIR AND HIGH PRESSURE WILL BUILD IN FOR THE OVERNIGHT LEADING TO YET ANOTHER NIGHT OF WIDESPREAD LOWS OF ZERO OR BELOW. AT THIS POINT...WE ARE COUNTING ON THE WIND TO DROP OFF ENOUGH TO MINIMIZE WIND CHILLS... SO NO HEADLINES ARE PLANNED AT THIS TIME. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... HIGH PRESSURE WILL PROVIDE A MUCH BRIGHTER DAY FRIDAY. FORECAST SOUNDINGS SUGGEST THE POTENTIAL FOR SOME STRATOCU TO GATHER UNDER THE STRONG SUBSIDENCE INVERSION...BUT A FAIR AMOUNT OF SUNSHINE SHOULD MANAGE TO MIX WITH ANY CLOUDS THAT FORM. ONCE AGAIN IT WILL BE MUCH COLDER THAN NORMAL WITH HIGHS GENERALLY IN THE 20S. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... SFC HIGH PRESSURE RIDGE AXIS WILL MIGRATE EWD ACROSS THE MID ATLANTIC REGION FRIDAY NIGHT AND SETTLE INTO THE SOUTHEAST STATES ON SATURDAY. AN INCREASE IN SW GRADIENT WINDS AND CLOUDS ARE EXPECTED ACROSS THE NW HALF OF THE CWA IN ADVANCE OF A WEAK LOW MOVING ACROSS THE GREAT LAKES. MEANWHILE MAINLY CLEAR SKIES AND LIGHTER WINDS ACROSS THE LOWER SUSQ VALLEY SHOULD PREVAIL NEAR THE DEPARTING SFC RIDGE. THIS PATTERN FAVORS A NON-DIURNAL TREND WITH LOWS IN THE MID TEENS OCCURRING EARLY ACROSS THE NW MTNS FRIDAY NIGHT WITH A STEADY TO SLOW RISE INTO SATURDAY MORNING. A MORE TYPICAL NOCTURNAL TEMP CURVE SHOULD ALLOW TEMPS TO FALL TO AROUND 10F OVER THE LOWER SQV. BROAD UPPER CYCLONIC FLOW WILL CONTINUE INTO EARLY NEXT WEEK AS ADDITIONAL SHORTWAVE IMPULSES MOVE FROM CENTRAL CANADA THROUGH THE NORTHERN TIER OF THE U.S. THERE ARE FEWER DIFFERENCES NOTED OVERALL COMPARED TO PREVIOUS MODEL CYCLES WITH RESPECT TO THE TIMING AND DEPTH OF EACH IMPULSE. ONE IMPULSE WILL DRIVE A SURFACE WAVE AND ASSOCIATED FRONT THROUGH THE GREAT LAKES REGION ON SAT AND THEN INTO NEW ENGLAND ON SUN. AN ADDITIONAL IMPULSE WILL TAKE A SIMILAR TRACK THROUGH THE GREAT LAKES LATER SUN INTO EARLY MON ALONG WITH A WEAK FRONT. GIVEN THE FAST DEEPER LAYER WEST NORTHWEST FLOW OVER THE REGION...THE AMPLITUDE OF EACH IMPULSE SHOULD BE RATHER SMALL WITH MOISTURE AVAILABILITY QUITE LIMITED. THEREFORE EXPECT OCCASIONAL SNOW SHOWERS MAINLY OVER THE HIGHER TERRAIN OF THE NORTHERN ALLEGHENIES WITH 48 ACCUMS OF 1-2" POSSIBLE OVER THE NW MTNS BY 12Z MON. THE MODELS AND ENSEMBLE MEANS ARE AGREEABLE/CONSISTENT WITH THE MAIN THEMES OF THE LARGE SCALE PATTERN INTO NEXT WEEK. THESE INCLUDE AN INCREASINGLY ZONAL/PROGRESSIVE NRN STREAM FLOW ACROSS SRN CANADA...AND SRN ROCKIES/PLAINS INTO MEXICO MEAN TROUGH AND STRONG RIDGE E OF THE BAHAMAS. AS THE MEAN PATTERN ALOFT BECOMES INCREASINGLY FLATTER...CONFIDENCE IS RELATIVELY HIGH IN A MAINLY DRY PERIOD WITH STEADILY INCREASING/MODERATING TEMPERATURES TO AT OR SLIGHTLY ABOVE EARLY-MID MARCH CLIMATE NORMALS. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... MOST OF THE FLYING AREA WILL REMAIN VFR NORTH OF THE BANDED PRECIPITATION THAT IS CAUSING MVFR-IFR/LIFR FROM JOHNSTOWN EAST THROUGH THE LOWER SUSQ VALLEY. CONDITIONS WILL SLOWLY IMPROVE OVER SOUTHERN AND SOUTHEASTERN AREAS THIS AFTERNOON...WITH LANCASTER-HARRISBURG LIKELY BEING THE LAST TO ENJOY IN THE IMPROVING CONDITIONS. EXPECT MOST TERMINALS TO BE VFR OVERNIGHT. JST MAY BE THE EXCEPTION WITH LOW CLOUDS HANGING IN TOUGH UNDER THE UPSLOPE FLOW. OUTLOOK... FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. TUE...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ036- 057>059-063>066. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ033>035. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...STEINBUGL AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1252 PM EST THU MAR 5 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA BY LATER TODAY AND THIS EVENING. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /THROUGH TONIGHT/... HAVE CANCELED PART OF THE WEATHER ADVISORY...OTHERWISE THE NEAR TERM FORECAST HAS NOT CHANGED. AS OF MID DAY THE MOST INTENSE MESOSCALE SNOW BAND EXTENDS FROM FRANKLIN COUNTY THROUGH LEBANON COUNTY. MORE OR LESS ON TRACK WITH RAP PLACEMENT AND TIMING OF BEST FRONTOGENTIC FORCING. HRRR SHOWS THE SNOW GRADUALLY SETTLING SOUTHEAST OVER THE NEXT 2-4 HOURS...WITH A RAPID TAPERING OFF AFTER 21Z. THIS SUPPORTS FINAL SNOW TALLIES IN THE 6-10 INCH RANGE ON AVERAGE. DRIER AIR AND HIGH PRESSURE WILL BUILD IN FOR THE OVERNIGHT LEADING TO YET ANOTHER NIGHT OF WIDESPREAD LOWS OF ZERO OR BELOW. AT THIS POINT...WE ARE COUNTING ON THE WIND TO DROP OFF ENOUGH TO MINIMIZE WIND CHILLS... SO NO HEADLINES ARE PLANNED AT THIS TIME. && .SHORT TERM /FRIDAY/... HIGH PRESSURE WILL PROVIDE A MUCH BRIGHTER DAY FRIDAY. FORECAST SOUNDINGS SUGGEST THE POTENTIAL FOR SOME STRATOCU TO GATHER UNDER THE STRONG SUBSIDENCE INVERSION...BUT A FAIR AMOUNT OF SUNSHINE SHOULD MANAGE TO MIX WITH ANY CLOUDS THAT FORM. ONCE AGAIN IT WILL BE MUCH COLDER THAN NORMAL WITH HIGHS GENERALLY IN THE 20S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... SFC HIGH PRESSURE RIDGE WILL SAG JUST TO THE SOUTH OF THE MID ATLANTIC REGION FRIDAY NIGHT...ALLOWING FOR AN INCREASE IN SWRLY SFC WINDS AND CLOUDS ACROSS THE NW HALF OF THE CWA...WITH MAINLY CLEAR SKIES AND LIGHTER WIND PERSISTING ACROSS THE LOWER SUSQ VALLEY...MUCH CLOSER TO THE SFC RIDGE. COLD TEMPS IN THE LOW-MID TEENS ACROSS THE NW MTNS FRIDAY WILL STAY NEARLY STEADY OR EVEN RISE A FEW DEG F FRIDAY NIGHT...WHILE A MORE NORMAL NOCTURNAL TEMP DROP OF 12-15F IS EXPECTED ACROSS THE LOWER SUSQ VALLEY. SATURDAY THE TEMPERATURES AT 850 MB RETURN CLOSER TO NORMAL AND HIGH PRESSURE DRIFTS TO OUR SOUTH. PENNSYLVANIA SHOULD REMAIN NORTH OF THIS WEAK HIGH....CUTTING OFF ANY MOISTURE TO THE SOUTH...KEEPING THE REGION IN WEAK WESTERLY FLOW INTO MONDAY. THE PERIOD SHOULD BE RELATIVELY DRY WITH ANY FRONTAL PRECIPITATION SUPPRESSED TO OUR SOUTH AND ONLY WEAK NORTHERN STREAM WAVES TO OUR NORTH TO GENERATE ANY PRECIPITATION. SO...KEPT THE POPS LOW THROUGH THE PERIOD AND ANY LIGHT PRECIPITATION WOULD LIKELY BE SNOW AS 850 HPA TEMPS STAY BELOW 0C. BEST CHANCE OF ANY PRECIPITATION WOULD BE IN NORTHERN AREAS SHOULD ONE OF THE NORTHERN STREAM WAVES PROVE TO BE STRONGER THAN GUIDANCE IMPLIES. A RIDGE IS FORECAST TO BUILD OVER THE REGION TUESDAY INTO WEDNESDAY AND OUR LOWER TROPOSPHERE TEMPERATURES SHOULD GET AT LEAST SLIGHTLY....ABOVE NORMAL....BOTH TUESDAY INTO WEDNESDAY. THIS SHOULD PROVIDE AT LEAST 2 DAYS OF NEAR SEASONAL TEMPERATURES FOR A CHANGE. RELATIVELY WARM DAYS AND COLD NIGHTS...A GOOD SLOW WAY TO MELT SNOW WITHOUT FLOODING. THE NAEFSBC AND GEFSBC SUGGEST A FRONTAL PASSAGE THURSDAY WITH SLIGHTLY COLDER TEMPERATURES AS ANOTHER HIGH PRESSURE SYSTEM IS FORECAST TO MOVE OVER THE NORTHEASTERN UNITED STATES THURSDAY INTO SATURDAY NEXT WEEK. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... MOST OF THE FLYING AREA WILL REMAIN VFR NORTH OF THE BANDED PRECIPITATION THAT IS CAUSING MVR-IFR/LIFR FROM JOHNSTOWN EAST THROUGH THE LOWER SUSQ VALLEY. CONDITIONS WILL SLOWLY IMPROVE OVER SOUTHERN AND SOUTHEASTERN AREAS THIS AFTERNOON...WITH LANCASTER-HARRISBURG LIKELY BEING THE LAST TO ENJOY IN THE IMPROVING CONDITIONS. EXPECT MOST TERMINALS TO BE VFR OVERNIGHT. JST MAY BE THE EXCEPTION WITH LOW CLOUDS HANGING IN TOUGH UNDER THE UPSLOPE FLOW. OUTLOOK... FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. TUE...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ036- 057>059-063>066. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ033>035. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...GRUMM/LAMBERT AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1223 PM EST THU MAR 5 2015 .SYNOPSIS... A WAVE OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA BY LATER TODAY AND THIS EVENING. HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE STATE FRIDAY AND SATURDAY. A STRONG UPPER-LEVEL RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK. THIS SHOULD PROVIDE GENERALLY FAIR WEATHER AND SEVERAL DAYS OF NEAR NORMAL TEMPERATURES AND RELATIVELY DRY WEATHER. && .NEAR TERM /THROUGH TONIGHT/... AS OF MID DAY THE MOST INTENSE MESOSCALE SNOW BAND EXTENDS FROM FRANKLIN COUNTY THROUGH LEBANON COUNTY. MORE OR LESS ON TRACK WITH RAP PLACEMENT AND TIMING OF BEST FRONTOGENTIC FORCING. HRRR SHOWS THE SNOW GRADUALLY SETTLING SOUTHEAST OVER THE NEXT 2-4 HOURS...WITH A RAPID TAPERING OFF AFTER 21Z. THIS SUPPORTS FINAL SNOW TALLIES IN THE 6-10 INCH RANGE ON AVERAGE. DRIER AIR AND HIGH PRESSURE WILL BUILD IN FOR THE OVERNIGHT LEADING TO YET ANOTHER NIGHT OF WIDESPREAD LOWS OF ZERO OR BELOW. AT THIS POINT...WE ARE COUNTING ON THE WIND TO DROP OFF ENOUGH TO MINIMIZE WIND CHILLS... SO NO HEADLINES ARE PLANNED AT THIS TIME. && .SHORT TERM /FRIDAY/... HIGH PRESSURE WILL PROVIDE A MUCH BRIGHTER DAY FRIDAY. FORECAST SOUNDINGS SUGGEST THE POTENTIAL FOR SOME STRATOCU TO GATHER UNDER THE STRONG SUBSIDENCE INVERSION...BUT A FAIR AMOUNT OF SUNSHINE SHOULD MANAGE TO MIX WITH ANY CLOUDS THAT FORM. ONCE AGAIN IT WILL BE MUCH COLDER THAN NORMAL WITH HIGHS GENERALLY IN THE 20S. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... SFC HIGH PRESSURE RIDGE WILL SAG JUST TO THE SOUTH OF THE MID ATLANTIC REGION FRIDAY NIGHT...ALLOWING FOR AN INCREASE IN SWRLY SFC WINDS AND CLOUDS ACROSS THE NW HALF OF THE CWA...WITH MAINLY CLEAR SKIES AND LIGHTER WIND PERSISTING ACROSS THE LOWER SUSQ VALLEY...MUCH CLOSER TO THE SFC RIDGE. COLD TEMPS IN THE LOW-MID TEENS ACROSS THE NW MTNS FRIDAY WILL STAY NEARLY STEADY OR EVEN RISE A FEW DEG F FRIDAY NIGHT...WHILE A MORE NORMAL NOCTURNAL TEMP DROP OF 12-15F IS EXPECTED ACROSS THE LOWER SUSQ VALLEY. SATURDAY THE TEMPERATURES AT 850 MB RETURN CLOSER TO NORMAL AND HIGH PRESSURE DRIFTS TO OUR SOUTH. PENNSYLVANIA SHOULD REMAIN NORTH OF THIS WEAK HIGH....CUTTING OFF ANY MOISTURE TO THE SOUTH...KEEPING THE REGION IN WEAK WESTERLY FLOW INTO MONDAY. THE PERIOD SHOULD BE RELATIVELY DRY WITH ANY FRONTAL PRECIPITATION SUPPRESSED TO OUR SOUTH AND ONLY WEAK NORTHERN STREAM WAVES TO OUR NORTH TO GENERATE ANY PRECIPITATION. SO...KEPT THE POPS LOW THROUGH THE PERIOD AND ANY LIGHT PRECIPITATION WOULD LIKELY BE SNOW AS 850 HPA TEMPS STAY BELOW 0C. BEST CHANCE OF ANY PRECIPITATION WOULD BE IN NORTHERN AREAS SHOULD ONE OF THE NORTHERN STREAM WAVES PROVE TO BE STRONGER THAN GUIDANCE IMPLIES. A RIDGE IS FORECAST TO BUILD OVER THE REGION TUESDAY INTO WEDNESDAY AND OUR LOWER TROPOSPHERE TEMPERATURES SHOULD GET AT LEAST SLIGHTLY....ABOVE NORMAL....BOTH TUESDAY INTO WEDNESDAY. THIS SHOULD PROVIDE AT LEAST 2 DAYS OF NEAR SEASONAL TEMPERATURES FOR A CHANGE. RELATIVELY WARM DAYS AND COLD NIGHTS...A GOOD SLOW WAY TO MELT SNOW WITHOUT FLOODING. THE NAEFSBC AND GEFSBC SUGGEST A FRONTAL PASSAGE THURSDAY WITH SLIGHTLY COLDER TEMPERATURES AS ANOTHER HIGH PRESSURE SYSTEM IS FORECAST TO MOVE OVER THE NORTHEASTERN UNITED STATES THURSDAY INTO SATURDAY NEXT WEEK. && .AVIATION /17Z THURSDAY THROUGH MONDAY/... MOST OF THE FLYING AREA WILL REMAIN VFR NORTH OF THE BANDED PRECIPITATION THAT IS CAUSING MVR-IFR/LIFR FROM JOHNSTOWN EAST THROUGH THE LOWER SUSQ VALLEY. CONDITIONS WILL SLOWLY IMPROVE OVER SOUTHERN AND SOUTHEASTERN AREAS THIS AFTERNOON...WITH LANCASTER-HARRISBURG LIKELY BEING THE LAST TO ENJOY IN THE IMPROVING CONDITIONS. EXPECT MOST TERMINALS TO BE VFR OVERNIGHT. JST MAY BE THE EXCEPTION WITH LOW CLOUDS HANGING IN TOUGH UNDER THE UPSLOPE FLOW. OUTLOOK... FRI-SAT...MAINLY VFR. SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE. TUE...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ033- 036-057>059-063>066. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR PAZ024>028-034-035-050-052-056. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...GRUMM/LAMBERT AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
113 PM EST THU MAR 5 2015 .SYNOPSIS... LOW PRESSURE OVER SOUTHERN NORTH CAROLINA WILL BE MOVING SOUTH AND EAST THROUGH THIS EVENING...AS COLDER AIR SLIDES EAST AND SOUTH ACROSS OUR REGION. WINTRY WEATHER ENDS FROM WEST TO EAST FROM LATE AFTERNOON INTO THIS EVENING. HIGH PRESSURE HEADS TO THE MOUNTAINS BY FRIDAY. && .NEAR TERM /UNTIL 9 PM THIS EVENING/... AS OF 102 PM EST THURSDAY... UPDATED FORECAST REFLECTS HIGHER SNOW BANDING AND SNOW AMOUNTS ACROSS PORTIONS OF THE ALLEGHANY HIGHLANDS...SOUTH TO THE NEW RIVER VALLEY EAST TO THE PIEDMONT NORTH OF HWY 460. GOOD FRONTOGENETICAL FORCING IN THE 800-750MB LAYER WITH EPV ATOP OVER THE ALLEGHANYS SHOWING BANDING POTENTIAL EXISTS WHICH IS EVIDENT ON RADAR. STILL NOT PLANNING ON HEADLINE CHANGES...THOUGH THINK APPOMATTOX COUNTY COULD EXCEED 4 INCHES BY EVENING. STILL LOOKS LIKE THE SOUTHERN CWA WILL BE LIMITED ON AMOUNTS. THE LATEST HRRR AND LOCAL WRF START CLEARING THINGS ACROSS THE MOUNTAINS AFTER 3-4 PM...THEN EXITS THE PIEDMONT BY 03Z. HOWEVER...THEY SHOW POTENTIAL NARROW BAND OVER THE ROANOKE VALLEY LATE THIS AFTERNOON WHICH COULD DUMP ANOTHER 1-2 INCHES...IF THIS SETS UP. && .SHORT TERM /9 PM THIS EVENING THROUGH SUNDAY NIGHT/... AS OF 300 AM EST THURSDAY... ARCTIC HIGH PRESSURE WILL BUILD EAST UP THE OHIO RIVER VALLEY...MAKING FOR MOSTLY CLEAR SKIES AND LIGHT WINDS BY SUNRISE FRIDAY...IDEAL CONDITIONS FOR STRONG RADIATIONAL COOLING. THIS WILL RESULT IN ONE LAST SHOT OF FRIGID AIR FOR THE FORESEEABLE FUTURE AS WE START FRIDAY MORNING OFF WITH TEMPERATURES RANGING FROM NEAR ZERO ALONG THE INTERSTATE 64 CORRIDOR...TO THE LOW 20S ACROSS THE FOOTHILLS AND PIEDMONT OF NORTH CAROLINA. THE ARCTIC AIRMASS WILL KEEP FRIDAY AFTERNOON TEMPERATURES WELL BELOW NORMAL...WITH HIGHS RANGING FROM THE UPPER 20S NORTH TO AROUND 40 SOUTH. TEMPERATURES WILL BEGIN TO MODERATE FOR FRIDAY NIGHT AND SATURDAY AS WINDS SHIFT MORE WEST SOUTHWESTERLY AHEAD OF AN APPROACHING WEAK COLD FRONT...CAUSING THE COLDER AIR TO RETREAT BACK TO THE NORTH. WILL START SATURDAY OFF WITH LOWS IN THE UPPER TEENS AND LOW 20S FOR MUCH OF THE REGION...WITH ABUNDANT SUNSHINE HELPING AFTERNOON HIGHS WARM INTO THE 40S ACROSS THE MOUNTAINS AND THE LOW TO MID 50S EAST OF THE BLUE RIDGE. THE WARMUP WILL CONTINUE INTO SUNDAY...ALBEIT WITH INCREASING CLOUDS BUT OTHERWISE DRY CONDITIONS. AFTERNOON HIGHS WILL RANGE FROM THE MID/UPPER 40S WEST TO THE MID/UPPER 50S EAST. WILL BE KEEPING AN EYE ON AN UPPER LEVEL DISTURBANCE PASSING ACROSS THE SOUTHEAST STATES SUNDAY NIGHT...WHICH HAS THE POTENTIAL OF BRINGING LIGHT RAIN EARLY IN THE NIGHT...CHANGING OVER TO A LIGHT WINTRY MIX TOWARD SUNRISE MONDAY. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM EST WEDNESDAY... THERE HAS BEEN CONSIDERABLE VARIATION IN THE MODEL GUIDANCE DURING THE SUNDAY NIGHT THROUGH TUESDAY TIME PERIOD. WHILE EACH IS FAIRLY CONSISTENT THAT A LONG WAVE TROUGH WILL DEVELOP ACROSS THE EASTERN THIRD OF CONUS...THERE HAVE BEEN INCONSISTENCIES AS TO WHETHER OR NOT...AND WHEN...AND WHAT TRACK A SOUTHERN STREAM SYSTEM MAY GET PICKED UP ON THE EAST SIDE OF THIS TROUGH AND PROGRESS NORTHEAST ACROSS OUR AREA. THE GFS HAS NOT BEEN FAVORABLE OF THIS OCCURRENCE. THE ECMWF WAS OPTIMISTIC ON AN ARRIVAL A SOUTHERN SYSTEM ON MONDAY. OUR FORECAST TODAY WILL REFLECT TEMPERATURES CONTINUING TO MODERATE THROUGH MONDAY...WITH THE THINKING THAT THE DEVELOPING TROUGH AXIS WILL REMAIN TO OUR WEST...AND WE WILL CONTINUE IN WARM AIR ADVECTION AT THE SURFACE. IT WILL ALSO REFLECT THE POTENTIAL FOR SOME ISOLATED TO SCATTERED UPSLOPE SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA WHERE 850 MB FLOW WILL BE MORE W-NW. IT WILL ALSO ALLOW FOR A SLIGHT CHANCE OF A SOUTHERN STREAM SYSTEM IMPACTING THE AREA ON TUESDAY WITH RAIN OR FREEZING RAIN. THE LATEST GUIDANCE FOR THE EARLY TO MIDDLE PART OF NEXT WEEK CONTINUES TO FLUCTUATES IN REGARDS TO THE TIMING AND TRACK OF A SOUTHERN STREAM SYSTEM. THE LATEST TRENDS BRING THE GFS INTO PLAY NOW FOR BRINGING A SYSTEM THROUGH THE AREA ON WEDNESDAY...THE CANADIAN AND ECWMF STILL A LITTLE EARLIER. IN ADDITION TO THE SMALL CHANCE OF PRECIPITATION ON TUESDAY...WE WILL ALSO ADD WEDNESDAY INTO THE MIX TO REFLECT THE MODEL VARIATIONS AND A SMALL POTENTIAL EACH DAY FOR A LOW AND ITS ASSOCIATED PRECIPITATION TO PROGRESS OVER OR NEAR THE REGION. WHILE MOST OF THE REGION SHOULD EXPERIENCE RAIN ON WEDNESDAY...A FEW SPOTS IN THE SOUTHEAST WEST VIRGINIA MAY BE COLD ENOUGH FOR A BRIEF PERIOD OF FREEZING RAIN. HIGH TEMPERATURES ON WEDNESDAY WILL BE MILDER THAN THOSE OF TUESDAY. EXPECT A RANGE OF LOW TO MID 50S ACROSS THE MOUNTAINS WITH UPPER 50S TO LOWER 60S ACROSS THE PIEDMONT. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 1255 PM EST THURSDAY... POOR FLYING WEATHER THROUGH THIS AFTERNOON WITH RAIN CHANGING TO SLEET AND SNOW. MODELS ALL CLEAR THINGS OUT THIS EVENING BUT EXPECT LINGERING LOW LVL MOISTURE FOR A FEW HOURS AFTER THE PRECIP ENDS. NORTH TO NORTHEAST WINDS WILL BE GUSTY AT TIMES AT DAN THIS AFTERNOON. OVERNIGHT...MODELS ARE HINTING AT FOG POTENTIAL IN THE WEST WITH CLEARING SKIES...AND DID ALLOW FOR MVFR/IFR FOG AT BCB/LWB. CONFIDENCE IS MODERATE ON FOG. EXTENDED FORECAST... FRIDAY TO SUNDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER. SOME RAIN AND SNOW SHOWERS ARE POSSIBLE ON MONDAY IN THE WESTERN MOUNTAINS WITH BRIEF MVFR EXPECTED. && .HYDROLOGY... AS OF 1030 AM EST THURSDAY... FLOODING STILL ONGOING OVER THE BLUESTONE AND CLINCH RIVERS. PRECIP CHANGING TO SLEET/SNOW WILL CUT BACK ON RUNOFF WHILE TEMPS FALL. WILL BE WATCHING THE UPPER JAMES AND THE GREENBRIER RIVERS AS WELL FOR POSSIBLE FLOOD CONCERNS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ007- 009>018-022-034. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ019- 020-023-024. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ032-033-043>046-058-059. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ035- 047. NC...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ001- 002-018. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NCZ003>006-019-020. WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ042>044-507-508. && $$ SYNOPSIS...AMS NEAR TERM...AMS/WP SHORT TERM...NF LONG TERM...DS AVIATION...AMS/WP HYDROLOGY...PM