Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/15/14


AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
854 AM PST THU NOV 13 2014 .SYNOPSIS...OUTSIDE OF A FEW SHOWERS INTO THE AFTERNOON HOURS, LOOK FOR COOL AND DRY CONDITIONS TODAY. HIGH PRESSURE WILL THEN REBUILD WITH A RETURN TO DRY AND SEASONABLE WEATHER THROUGH THE UPCOMING WEEKEND. RAIN MAY RETURN NEXT WEEK BUT PROBABLY NOT UNTIL MIDWEEK OR BEYOND. && .DISCUSSION...AS OF 8:50 AM PST THURSDAY...RAIN HAS ENDED ACROSS MOST OF OUR AREA, ALTHOUGH KMUX IS STILL SHOWING A FEW ECHOS OVER SOUTHEASTERN PORTIONS OF THE CWA. RAINFALL TOTALS HAVE BEEN GENERALLY UNDER 1/3" FOR URBAN SPOTS WITH A FEW HIGHER ELEVATION LOCATIONS ABOVE HALF AN INCH. ONCE STATION ON MOUNT TAM ENDED UP WITH AROUND 3/4". MINOR FORECAST UPDATE WAS DONE TO REFLECT THE RAINFALL ENDED THIS MORNING. MAIN FORECAST CONCERN WILL BE FOR POSSIBLE RAINFALL LATE SATURDAY INTO SUNDAY PLUS NEXT WORK WEEK. STILL WAITING ON THE ECMWF TO COME IN BEFORE DECIDING TO MAKE ANY SUBSTANTIAL CHANGES TO THE FORECAST. .PREVIOUS DISCUSSION...RAIN EVENT SEEMS TO BE VERIFYING ABOUT AS ADVERTISED WITH QUARTER INCH RAIN TOTALS ON AVERAGE. THERE HAVE BEEN A FEW SITES AROUND HALF INCH IN THE NORTH BAY AND LESSER AMOUNTS FROM MONTEREY SOUTHWARD...BUT IT SEEMS LIKE MOST AREAS RECEIVED FAIRLY UNIFORM LIGHT RAIN AMOUNTS. SCATTERED SHOWERS AND AREAS OF FOG WILL IMPACT THE EARLY MORNING COMMUTE WITH SOME WET ROADWAYS. IN GENERAL CONDITIONS WILL RAPIDLY IMPROVE BY 17-18Z WITH MOST SHOWER ACTIVITY WINDING DOWN EXCEPT PERHAPS SOME OF THE INLAND HILLS OF SANTA CLARA AND SAN BENITO COUNTY. WILL HAVE TO MONITOR FOR POSSIBLE FOG FORMATION TONIGHT GIVEN TODAY`S LIGHT RAIN AND THEN SOME HIGH PRESSURE QUICKLY BUILDING OVER THE REGION. DRY WEATHER WILL RETURN FOR FRIDAY WITH SEASONABLE TEMPERATURES IN THE 60S. RIGHT NOW THERE IS HIGH CONFIDENCE FOR DRY WEATHER AT LEAST THROUGH SATURDAY IN TERMS OF WEEKEND PLANNING WITH AFTERNOON HIGHS IN THE UPPER 60S AND LOWER 70S. THE LONG RANGE FORECAST REMAINS SOMEWHAT MUDDLED. THE DRIVING FORCE SEEMS TO BE THE ARCTIC AIR THAT IS BECOMING ENTRENCHED OVER THE EASTERN HALF OF THE COUNTRY. THEN LATE SATURDAY INTO SUNDAY A CHUNK OF COLD AIR WANTS TO DROP INTO THE NORTHERN ROCKIES AND TRY AND EXTEND AS FAR WEST AS EASTERN OREGON AND WESTERN NEVADA. SOME OF THE MODELS WANT TO BRING THIS SYSTEM DOWN INTO CALIFORNIA BUT THE MOST OBJECTIVE GUIDANCE SUGGESTS IT SHOULD STAY EAST OF THE SIERRA. UPSHOT IS TO KEEP THE BAY AREA FORECAST DRY ON SUNDAY FOR THE TIME BEING. THE LONG RANGE FORECAST REMAINS PROBLEMATIC AS WELL WITH LOTS OF JET STREAM ENERGY OVER THE PACIFIC...THE RIDGE OVER ALASKA AND THE COLD TROUGH OVER THE EASTERN US. WERE SEEING POOR MODEL RUN TO RUN CONSISTENCY. LATEST SOLUTIONS HAVE THE GEM BEING PRETTY WET AND INDICATING POTENTIAL FOR MULTIPLE STORMS NEXT WEEK WHILE THE GFS HAS GONE DRY UNTIL LATE NEXT WEEK. INTERNAL COMPUTER ISSUES DIDN`T ALLOW ECMWF ANALYSIS TONIGHT AND THE LONG FORECAST WAS BLENDED WITH SURROUNDING WFOS. IN TERMS OF RAINFALL LOOKS LIKE PATIENCE WILL BE NEEDED. && .AVIATION...AS OF 4:30 AM PST THURSDAY...STORM SYSTEM JUST OFFSHORE OF NORCAL COASTLINE SPREADING -RA AND MVFR CIGS/VISBY ACROSS TAF SITES THIS MORNING. HRRR SUGGESTS BULK OF WIDESPREAD PRECIP DWINDLES AFTER 14Z WITH -SHRA/VCSH LIKELY THROUGH BAY AREA UNTIL 19Z THU AND MONTEREY BAY AIRPORTS THROUGH 22Z THU. WINDS VEER WITH FRONTAL PASSAGE TOWARDS THE WEST BETWEEN 18Z AND 19Z THU AT KSFO AND KOAK. MEDIUM CONFIDENCE ON TIMING OF WIND SHIFT/RAIN TAPER. VICINITY OF KSFO...PREDOMINATELY MVFR CIGS THROUGH THURSDAY MORNING WITH SLIGHT PROBABILITY OF IFR CIGS. PRECIPITATION TAPERS OFF AFTER 14Z THU... WITH LIGHTER RAIN SHOWERS IN VICINITY THROUGH 19Z THU. WINDS VEER FROM SE TO SW 17-18Z THU. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS. PRECIPITATION TAPERS OFF AFTER 16Z WITH LIGHTER RAIN SHOWERS IN VICINITY THROUGH 22Z THU. && .MARINE...AS OF 04:05 AM PST THURSDAY...NORTHWEST WINDS HAVE DEVELOPED OVER THE COASTAL WATERS IN THE WAKE OF FRONTAL PASSAGE AND WILL PERSIST INTO THE WEEKEND. NW WINDS GRADUALLY DECLINE INTO THE WEEKEND EXCEPT ALONG THE BIG SUR COASTLINE. WEST TO NORTHWEST DOMINATE SWELL WITH GRADUALLY SHORTENING PERIODS ARE EXPECTED THROUGH THE FORECAST PERIOD. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: BELL/RWW AVIATION/MARINE: DRP VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
433 AM PST THU NOV 13 2014 .SYNOPSIS...SCATTERED SHOWERS WILL CONTINUE EARLY THIS MORNING ACROSS THE BAY AREA BUT END BY MID-MORNING OR LUNCHTIME. HIGH PRESSURE WILL THEN REBUILD WITH A RETURN TO DRY AND SEASONABLE WEATHER THROUGH THE UPCOMING WEEKEND. RAIN MAY RETURN NEXT WEEK BUT PROBABLY NOT UNTIL MIDWEEK OR BEYOND. && .DISCUSSION...AS OF 3:43 AM PST THURSDAY...RAIN EVENT SEEMS TO BE VERIFYING ABOUT AS ADVERTISED WITH QUARTER INCH RAIN TOTALS ON AVERAGE. THERE HAVE BEEN A FEW SITES AROUND HALF INCH IN THE NORTH BAY AND LESSER AMOUNTS FROM MONTEREY SOUTHWARD...BUT IT SEEMS LIKE MOST AREAS RECEIVED FAIRLY UNIFORM LIGHT RAIN AMOUNTS. SCATTERED SHOWERS AND AREAS OF FOG WILL IMPACT THE EARLY MORNING COMMUTE WITH SOME WET ROADWAYS. IN GENERAL CONDITIONS WILL RAPIDLY IMPROVE BY 17-18Z WITH MOST SHOWER ACTIVITY WINDING DOWN EXCEPT PERHAPS SOME OF THE INLAND HILLS OF SANTA CLARA AND SAN BENITO COUNTY. WILL HAVE TO MONITOR FOR POSSIBLE FOG FORMATION TONIGHT GIVEN TODAYS LIGHT RAIN AND THEN SOME HIGH PRESSURE QUICKLY BUILDING OVER THE REGION. DRY WEATHER WILL RETURN FOR FRIDAY WITH SEASONABLE TEMPERATURES IN THE 60S. RIGHT NOW THERE IS HIGH CONFIDENCE FOR DRY WEATHER AT LEAST THROUGH SATURDAY IN TERMS OF WEEKEND PLANNING WITH AFTERNOON HIGHS IN THE UPPER 60S AND LOWER 70S. THE LONG RANGE FORECAST REMAINS SOMEWHAT MUDDLED. THE DRIVING FORCE SEEMS TO BE THE ARCTIC AIR THAT IS BECOMING ENTRENCHED OVER THE EASTERN HALF OF THE COUNTRY. THEN LATE SATURDAY INTO SUNDAY A CHUNK OF COLD AIR WANTS TO DROP INTO THE NORTHERN ROCKIES AND TRY AND EXTEND AS FAR WEST AS EASTERN OREGON AND WESTERN NEVADA. SOME OF THE MODELS WANT TO BRING THIS SYSTEM DOWN INTO CALIFORNIA BUT THE MOST OBJECTIVE GUIDANCE SUGGESTS IT SHOULD STAY EAST OF THE SIERRA. UPSHOT IS TO KEEP THE BAY AREA FORECAST DRY ON SUNDAY FOR THE TIME BEING. THE LONG RANGE FORECAST REMAINS PROBLEMATIC AS WELL WITH LOTS OF JET STREAM ENERGY OVER THE PACIFIC...THE RIDGE OVER ALASKA AND THE COLD TROUGH OVER THE EASTERN US. WERE SEEING POOR MODEL RUN TO RUN CONSISTENCY. LATEST SOLUTIONS HAVE THE GEM BEING PRETTY WET AND INDICATING POTENTIAL FOR MULTIPLE STORMS NEXT WEEK WHILE THE GFS HAS GONE DRY UNTIL LATE NEXT WEEK. INTERNAL COMPUTER ISSUES DIDNT ALLOW ECMWF ANALYSIS TONIGHT AND THE LONG FORECAST WAS BLENDED WITH SURROUNDING WFOS. IN TERMS OF RAINFALL LOOKS LIKE PATIENCE WILL BE NEEDED. && .AVIATION...AS OF 4:30 AM PST THURSDAY...STORM SYSTEM JUST OFFSHORE OF NORCAL COASTLINE SPREADING -RA AND MVFR CIGS/VISBY ACROSS TAF SITES THIS MORNING. HRRR SUGGESTS BULK OF WIDESPREAD PRECIP DWINDLES AFTER 14Z WITH -SHRA/VCSH LIKELY THROUGH BAY AREA UNTIL 19Z THU AND MONTEREY BAY AIRPORTS THROUGH 22Z THU. WINDS VEER WITH FRONTAL PASSAGE TOWARDS THE WEST BETWEEN 18Z AND 19Z THU AT KSFO AND KOAK. MEDIUM CONFIDENCE ON TIMING OF WIND SHIFT/RAIN TAPER. VICINITY OF KSFO...PREDOMINATELY MVFR CIGS THROUGH THURSDAY MORNING WITH SLIGHT PROBABILITY OF IFR CIGS. PRECIPITATION TAPERS OFF AFTER 14Z THU... WITH LIGHTER RAIN SHOWERS IN VICINITY THROUGH 19Z THU. WINDS VEER FROM SE TO SW 17-18Z THU. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS. PRECIPITATION TAPERS OFF AFTER 16Z WITH LIGHTER RAIN SHOWERS IN VICINITY THROUGH 22Z THU. && .MARINE...AS OF 04:05 AM PST THURSDAY...NORTHWEST WINDS HAVE DEVELOPED OVER THE COASTAL WATERS IN THE WAKE OF FRONTAL PASSAGE AND WILL PERSIST INTO THE WEEKEND. NW WINDS GRADUALLY DECLINE INTO THE WEEKEND EXCEPT ALONG THE BIG SUR COASTLINE. WEST TO NORTHWEST DOMINATE SWELL WITH GRADUALLY SHORTENING PERIODS ARE EXPECTED THROUGH THE FORECAST PERIOD. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: RWW AVIATION/MARINE: DRP VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
928 AM EST THU NOV 13 2014 .SYNOPSIS... A QUICK MOVING COASTAL LOW FORMS ALONG A COLD FRONT OFFSHORE TONIGHT AND MOVES TO THE EAST OF THE REGION EARLY FRIDAY. HIGH PRESSURE FOLLOWS FOR A MAJORITY OF THE WEEKEND BEFORE ANOTHER COLD FRONT MOVES THROUGH MONDAY MORNING. LOW PRESSURE SYSTEM, FORMING ALONG THE GULF COAST, MOVES ALONG THE FRONT CLOSE TO OUR REGION ON MONDAY INTO TUESDAY. HIGH PRESSURE MOVES BACK IN BEHIND THIS DEPARTING SYSTEM LATE ON TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MID AND HIGH LEVEL CLOUDS WERE SPREADING OVER OUR REGION FROM THE WEST AND SOUTHWEST THIS MORNING. THE SKY IS EXPECTED TO BECOME OVERCAST FOR THIS AFTERNOON. TEMPERATURES WERE MAINLY IN THE UPPER 30S AND LOWER 40S AT 900 AM. THE INCREASING CLOUD COVER WILL PREVENT TEMPERATURES FROM RISING ABOVE THE 40S DURING THE AFTERNOON HOURS. A NORTHERLY WIND AT 5 TO 10 MPH IS EXPECTED TO BACK TOWARD THE NORTHWEST AS THE DAY PROGRESSES. THE HRRR CONTINUES TO SUPPORT THE IDEA OF LIGHT RAIN SPREADING INTO THE WESTERN AND SOUTHERN PARTS OF OUR FORECAST AREA LATE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... WIDESPREAD LIGHT PCPN ANTICIPATED AS A 140 MB HFC DEVELOPS OVER E PA BY FRIDAY MORNING. VERY NICE FGEN THIS EVENING AND BOTH THE 00Z AND 06Z/13 OPERATIONAL GFS HAVE ABOUT 17MBAR/SEC SNOW GROWTH MODELED OVER NE NJ BY 06Z FRI (550MB). THE NAM IS LESS ROBUST. NOTICING ALSO DECENT SNOW GROWTH ELSEWHERE I95 REGION NEAR 04-06Z DESPITE DRYING IN THE LOW LVLS AS NW WINDS INCREASE. COULD SEE BRIEF 1 MI LIGHT SNOW ALL ALONG I95 CORRIDOR FOR AN HOUR SO IN THE 10PM TO 2 AM TIME FRAME. LOOKING AT MAX WBZ UNDER 2C IN THE 0-6KM LAYER AND BL LESS THAN 0C IN LOWEST 750 FT...WE SHOULD SEE RAIN CHANGE TO SNOW NW OF I95 THIS EVENING AND THE QUESTION HOW QUICKLY DOES IT START STICKING... PROBABLY A MATTER OF ELEVATION AND TO SOME DEGREE INTENSITY. ITS CERTAINLY APPEARING TO BE SPS MATERIAL BUT NOT AN ADVY NW OF I95. I95 ITSELF...COULD END UP WITH A SKIFF OF SNOW ON THE GRASS IN SOME PLACES AS RAIN ENDS AS SNOW. PRIMARY PCPN EVENT IS 5 PM THIS AFTERNOON TO 3 AM FRIDAY. CLEARING TOWARD DAWN FRIDAY IN E PA AS WELL AS STIFFENING CAA SHOULD PERMIT SOME ICY SPOTS TO LINGER ON UNTREATED SFC TOMORROW MORNING FROM NW NJ THRU E PA (MAINLY WEST OF THE I95 CORRIDOR). THE 330 AND 630 AM FORECAST INCLUDING SNOW MAP I THINK IS CONSERVATIVE AND I COULD SEE ANYWHERE FROM .1 TO .5 ADDITIONAL TO THE TOTALS POSTED EARLY TODAY. I JUST DIDNT WANT TO FORCE THE TOOLS ANY FURTHER. ITS POSSIBLE I DID NOT COOL THE SFC TEMPS FAST ENOUGH THIS EVENING IN E PA AND NW NJ WHICH WOULD LEAD TO A SLIGHTLY HIGHER SNOW TOTAL. POPS WERE ADJUSTED UPWARD BY 20 PCT IN DELAWARE FOR THIS 630 AM ESTF. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... PERSISTENT MID-LEVEL TROUGHING OVER THE EASTERN HALF OF THE CONUS THROUGH THE LONG TERM. THOUGH THE TROUGH WILL RELOAD SEVERAL TIMES OVER THE NEXT 7 DAYS BRINGING WITH IT BOUTS OF UNSETTLED WEATHER, TEMPERATURES WILL AVERAGE WELL BELOW NORMAL. FRIDAY - SATURDAY...COLD FRONT WILL BE OFFSHORE WITH THE LAST OF THE LINGERING MOISTURE ASSOCIATED WITH THE QUICK COASTAL LOW MOVES AS IT MOVES INTO NEW ENGLAND. A FEW LAKE EFFECT STREAMERS MAY MAKE IT INTO OUR EXTREME NORTHERN ZONES, BUT WITH A FRESH AND DRY AIR MASS IN PLACE SHOULD BE MORE IN THE WAY OF FLURRIES. GUSTY NORTHWEST WINDS WILL HELP TO KEEP WIND CHILL VALUES IN THE MID- 30S. SATURDAY THE SURFACE FLOW BECOMES MORE WESTERLY AS THE DRYING TREND CONTINUES WITH WEAK RIDGING MOVING IN ALOFT. TEMPERATURES EACH DAY WILL AVERAGE IN THE LOW-40S. SUNDAY...SURFACE HIGH PRESSURE AND THE WEAK RIDGING BREAK DOWN AND MOVE OFFSHORE. LIGHT SOUTHERLY FLOW COMMENCES, THOUGH NOT EXPECTING A GREAT DEAL OF AIR MASS MODIFICATION WITH TEMPERATURES STILL IN THE 40S...DEWPOINTS INCREASE. THIS IS ALL AHEAD OF THE NEXT COLD FRONT PROGGED TO PUSH THROUGH LATE ON SUNDAY NIGHT INTO MONDAY MORNING. WE LOOK TO REMAIN DRY SUNDAY BEFORE INCREASING THETA-E ADVECTION KICKS IN WITH STRONGER LOW-LEVEL SOUTHERLY FLOW AND A PASSING MID-LEVEL SHORTWAVE LATE SUNDAY NIGHT. THERMALLY WE LOOK WARM ENOUGH FOR A MOSTLY OVER-RUNNING RAIN FROM THE LEHIGH VALLEY SOUTHWARD WITH A COLD BOUNDARY LAYER ACROSS THE NORTH FOR MOSTLY SNOW. MONDAY - TUESDAY...GUIDANCE CONTINUES TO INDICATE THAT THE NORTHERN STREAM ENERGY WILL BE THE DOMINATE FEATURE AS THE MID- LEVEL TROUGH RELOADS OVER THE GREAT LAKES AND AS THE GULF COAST LOW MOVES BY OUR REGION. PHASING STILL DOES NOT LOOK TO OCCUR THOUGH A JOG TOWARDS THE WEST-NORTHWEST HAS BEEN NOTED OVER THE PAST DAY OF RUNS WITH THE GFS...EC MOVED A LITTLE FURTHER EAST. THIS SETUP CONTINUES TO SHOW AN ABOVE 0C LOW-LEVEL PROFILE AS WARM AIR ADVECTS INTO THE REGION FROM THE SOUTH....COULD BE COLD ENOUGH AT THE START ACROSS THE NORTH FOR SNOW CHANGING TO RAIN DURING THE EVENT. ENSEMBLES SHOW A DECENT AMOUNT OF SPREAD STILL EXISTS SO WE WILL CONTINUE TO WATCH THE TRENDS THE NEXT COUPLE OF DAYS. BY TUESDAY THE LOW, WHATEVER STRENGTH IT BECOMES, WILL BE TO OUR NORTHEAST AND ANOTHER SHOT OF CANADIAN AIR SPILLS BACK INTO THE REGION. COULD SEE SOME SNOW SHOWERS ON THE BACKSIDE OF THE SYSTEM EARLY TUESDAY WITH STRONG NORTHWEST WINDS KICKING BACK IN. WEDNESDAY...DRY DAY EXPECTED WITH RIDGING MOVING BACK IN BUT WITH AN EVEN COLDER AIR MASS EXPECTED TO BE IN PLACE. HIGHS MAY NOT REACH 40F IN A LOT OF PLACES. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...CIGS BETWEEN 6000 AND 8000 FT RAPIDLY OVERSPREADING THE REGION FROM SW TO NE. LIGHT N TO NORTHWEST WIND. RAIN SHOULD DEVELOP AFTER 22Z SOUTHERN TERMINALS. TONIGHT...MVFR OR LOWER POSSIBLE IN -RA....EXCEPT RAIN CHANGING TO SNOW KRDG/KABE WITH A SMALL ACCUMULATION POSSIBLE BY 05Z WHILE RAIN SHOULD END AS WET SNOW WITH LITTLE OR NO ACCUM DURING THE PCPN KTTN/ KPNE/KPHL/KILG. IT IS POSSIBLE THAT KPHL-KTTN WILL SEE AN HOUR OF 1 MILE VSBY IN SNOW WITH JUST ABV FREEZING SFC TEMP SOMETIME BETWEEN 03Z-07Z. BEST CHC FOR ACCUMULATIVE SNOW OF ONE HALF INCH OR MORE ON PAVEMENT APPEARS TO BE KABE. AFTER 08Z FRIDAY...ICY SPOTS MAY DEVELOP FROM LEFTOVER MOISTURE TOWARD 10Z FRIDAY AS A STIFFENING NW WIND DEVELOPS....GUSTS TO 15 OR 20 MPH POSSIBLE AFTER 08Z FRIDAY. OUTLOOK... FRIDAY - SUNDAY...VFR. GUSTY NORTHWEST WINDS EXPECTED ON FRIDAY. MONDAY - TUESDAY...CHANCE OF MVFR WITH RAIN AND SNOW. SOUTHERLY WINDS INCREASE IN TIME. && .MARINE... SCA FOR LATER TONIGHT AND FRIDAY. TODAY, NW TO N WINDS 10-15 KT BECOMING 5-10 KT BY THE AFTN. TONIGHT...NW WINDS INCREASE WITH GUSTS 25-30 KT EXPECTED...STARTING AROUND 03Z LOWER DE BAY AND DE ATLC WATERS THEN PROGRESSING THROUGH THE NJ WATERS AROUND 06Z. WE LEFT GALE FORCE GUSTS IN THE WATERS E OF DELAWARE FROM OUR WIND GUST TOOL AS IT IS POSSIBLE THAT THERE COULD BE AN HOUR OR 2 OF GALE GUSTS NEAR 44009 EARLY FRIDAY MORNING. OUTLOOK... FRIDAY...CONTINUED SCA CONDITIONS WITH STRONG NORTHWEST WINDS AND SEAS AROUND 4 TO 6 FEET. SATURDAY - SUNDAY...SUB-SCA EXPECTED THOUGH SCA GUSTS MAY LINGER INTO EARLY SATURDAY MORNING. MONDAY...LOW END CHANCE OF SCA SEAS AS THE SURFACE FLOW INCREASES FROM THE SOUTH. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST FRIDAY FOR ANZ450>453. SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM EST FRIDAY FOR ANZ430-431-454-455. && $$ SYNOPSIS...HEAVENER NEAR TERM...IOVINO SHORT TERM...DRAG LONG TERM...HEAVENER AVIATION...DRAG/HEAVENER MARINE...DRAG/HEAVENER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
557 PM EST THU NOV 13 2014 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE AREA TONIGHT WITH A LARGE AREA OF CANADIAN HIGH PRESSURE BUILDING IN FRIDAY THROUGH SATURDAY. THE HIGH WILL WEAKEN AND RETREAT TO THE NORTHEAST ON SUNDAY IN ADVANCE OF A LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE AREA ON MONDAY. ANOTHER AREA OF CANADIAN HIGH PRESSURE WILL BUILD IN AND PREVAIL THROUGH LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... A COMPLEX SURFACE PATTERN IS IN PLACE ACROSS THE SOUTHEAST U.S. THIS EVENING. MESOANALYSIS AT 13/22Z PLACED A 1011 HPA SURFACE LOW VERY NEAR LITTLE RIVER INLET WITH A WEAK COLD FRONT EXTENDING SOUTHWEST FROM THE LOW...ESSENTIALLY PARALLELING SOUTH CAROLINA AND GEORGIA COASTS. AN AREA OF INTENSIFYING SURFACE FRONTOGENESIS PER 13/21Z RAP FGEN VECTORS STRETCHED WEST ACROSS THE SOUTH CAROLINA PEE DEE AND NORTHERN MIDLANDS INTO THE UPSTATE FROM THE WEAK SURFACE CYCLONE. THIS FEATURE WILL BECOME A STRONGER...SECONDARY COLD FRONT LATER TONIGHT AS MID-LEVEL COLD AIR ADVECTION INTENSIFIES AND FURTHER PUSHES COLD AIR AROUND AND EVENTUALLY OVER THE SOUTHERN APPALACHIANS IN THE WAKE OF THE DEPARTING LOW. THE PRIMARY COLD FRONT WILL PUSH OFF THE COAST OVER THE NEXT 1-2 HOURS AND BE FOLLOWED BY THE SECONDARY COLD FRONT DURING THE EARLY MORNING HOURS FRIDAY. THE VARIOUS FRONTAL PASSES THROUGH THE NIGHT POSES A PARTICULAR FORECAST CHALLENGE TO HOURLY TEMPERATURES. SHOULD ONLY SEE A SLIGHT TEMPERATURE FALL IN THE WAKE OF THE FIRST FRONT WITH A STEEPER THERMAL DECLINES OCCURRING LATE AS STRONG COLD AIR ADVECTION ENSUES IN THE WAKE OF THE SECONDARY COLD FRONT. THE COOLEST LOWS WILL ACTUALLY BE FOUND ACROSS INTERIOR SOUTHEAST GEORGIA AND THE CHARLESTON TRI-COUNTY AREA EARLY FRIDAY WITH A WARMER CORRIDOR STRETCHING ACROSS JASPER...BEAUFORT...SOUTHERN COLLETON AND LOWER CHARLESTON COUNTIES. LOWS WILL RANGE FROM THE UPPER 30S/LOWER 40S SOUTHWEST AND NORTHERN AREAS TO THE UPPER 40S/NEAR 50 ACROSS THE AFOREMENTIONED AREAS AROUND BEAUFORT COUNTY. CHANCES FOR MEASURABLE RAIN WILL REMAIN QUITE LOW...ALTHOUGH A FEW SPRINKLES CAN NOT BE COMPLETELY RULED OUT. GRIDDED POPS OF 10 PERCENT OR LESS WILL BE MAINTAINED. FOR THE EARLY EVENING UPDATE... 1. ADJUSTED HOURLY TEMPERATURES PER LATEST GLAMP...RAP AND H3R THERMAL TRENDS. 2. REMOVED MENTION OF SPRINKLES AS THIS PHENOMENA WILL NOT LAST MORE THAN A FEW MINUTES FOR ANY ONE LOCATION. 3. ADJUSTED WINDS SLIGHTLY BASED ON THE EXPECTED PASSAGES OF THE PRIMARY AND SECONDARY FRONTS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... A BROAD ZONAL FLOW ALOFT WILL FACILITATE STRONG CANADIAN HIGH PRESSURE DROPPING INTO THE SOUTHEAST UNITED STATES FRIDAY INTO SATURDAY. ALTHOUGH THE INITIAL COLD FRONT WILL BE OFFSHORE BY DAYBREAK...THE PRIMARY BOUNDARY WILL LINGER BEHIND AND MOVE OFF THE COAST LATE FRIDAY MORNING. STRONG COLD AND DRY ADVECTION WILL RESULT IN A CHILLY DAY ON FRIDAY WITH HIGH TEMPS IN THE MIDDLE 50S. THE THICKNESS PROGS ACTUALLY GIVE LOWER 50S IN MOST AREAS BUT THE ADDITION OF WEAK DOWNSLOPE FLOW WILL PUSH TEMPS A FEW DEGREES HIGHER. STRONG COLD AIR ADVECTION CONTINUES INTO FRIDAY NIGHT WITH 5-10 KT NORTHERLY FLOW PERSISTING. ALTHOUGH THE MIXED BOUNDARY LAYER WILL REDUCE THE EFFECTS OF RADIATIONAL COOLING...CLEAR SKIES WILL ONLY HELP TEMPS PLUMMET AFTER DARK. WE ARE STILL SHOWING OVERNIGHT LOWS IN THE UPPER 20S FAR INLAND WITH READINGS AT OR SLIGHTLY BELOW FREEZING IN MANY LOCATIONS AWAY FROM THE GA COAST AND SC BEACHES. BASED ON OUR GREATER THAN 50 PERCENT CONFIDENCE IN FREEZING TEMPS IN MUCH OF THIS AREA...WE ISSUED A FREEZE WATCH FOR FRIDAY NIGHT. THE COLD AIRMASS WILL REMAIN OVER THE AREA THROUGH SATURDAY. DESPITE SUNNY SKIES THE HIGHS WILL STILL ONLY MAKE IT TO THE MID 50S. SATURDAY NIGHT INTO SUNDAY...WITH THE BUILDING UPPER TROUGH TO OUR WEST THE SURFACE HIGH WILL SHIFT OFF THE COAST. LOW-LEVEL MOISTURE AND POSITIVE THERMAL ADVECTION WILL BRING HIGHER SURFACE DEWPOINTS AND HIGH TEMPS SUNDAY IN THE MID TO UPPER 60S. DIFLUENCE ALOFT WILL ALLOW A WEAK COASTAL TROUGH TO DEVELOP...WITH ISOLATED SHOWERS POSSIBLE OVER THE COASTAL WATERS AND IMMEDIATE SC COAST. LAKE WINDS...IT CONTINUES TO APPEAR THAT THE STRONGEST WINDS OVER LAKE MOULTRIE WILL OCCUR FRIDAY NIGHT AS THE PRESSURE GRADIENT TIGHTENS AND COLD AIR MOVES OVER THE RELATIVELY WARM LAKE WATERS. WE STILL ARE FORECASTING WIND GUSTS JUST BELOW LAKE WIND ADVISORY CRITERIA BUT WILL MAINTAIN MENTION OF THE POSSIBILITY IN THE HAZARDOUS WEATHER OUTLOOK. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE FIRST PART OF THE LONG TERM PERIOD WILL BE A BIT ACTIVE AS THE CORE OF A DEEP TROUGH DIVES OUT OF CENTRAL CANADA AND HELPS SPREAD SHORTWAVE ENERGY ACROSS THE GULF COAST AND SOUTHEAST. AN AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST EARLY MONDAY AND THEN QUICKLY RIDE NORTHEAST ALONG THE FRONT IN THE LEE OF THE APPALACHIANS. THIS WILL SPREAD A RELATIVELY QUICK SHOT OF MOISTURE INTO THE AREA WITH GOOD FORCING...ESPECIALLY FOR THE LATTER PART OF MONDAY AND INTO MONDAY NIGHT. POPS HAVE BEEN KEPT IN THE 50 PERCENT RANGE FOR NOW...BUT GIVEN SUFFICIENT CONTINUED MODEL AGREEMENT RAIN CHANCES WILL LIKELY RISE WITH FUTURE FORECAST UPDATES. SINCE WE LOOK TO BE SOLIDLY IN THE WARM SECTOR...ISOLATED THUNDER HAS BEEN ADDED TO THE FORECAST MONDAY AFTERNOON AND THEN FOR THE COASTAL WATERS MONDAY NIGHT. BEHIND THE COLD FRONT...CONFIDENCE IS INCREASING IN AN IMPRESSIVE ARCTIC BLAST TUESDAY ONWARD. IN FACT...RAW MODEL THICKNESS VALUES FROM THE ECMWF WOULD ONLY SUPPORT HIGHS IN THE LOW TO MID 40S BY WEDNESDAY. TEMPERATURES HAVE BEEN TRENDED DOWN TO FEATURE HIGHS AND LOWS APPROACHING 20 DEGREES BELOW NORMAL. ALSO... IT LOOKS LIKELY THAT A HARD FREEZE WILL OCCUR JUST ABOUT EVERYWHERE ESPECIALLY AS THE HIGH MOVES OVERHEAD AND SETS UP IDEAL RADIATIONAL COOLING CONDITIONS. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... MAINLY VFR. WILL LIKELY SEE A PERIOD OF MVFR CIGS AT KCHS FROM 10-13Z AND 13-15Z AT KSAV IN THE WAKE OF THE SECONDARY COLD FRONT. NO MAJOR IMPACTS ARE EXPECTED. EXTENDED AVIATION OUTLOOK...MVFR CEILINGS POSSIBLE SATURDAY NIGHT AND SUNDAY MORNING AS A WEAK COASTAL TROUGH MOVES INLAND. INCREASING CHANCES FOR CEILING REDUCTIONS SUNDAY NIGHT THROUGH MONDAY AS A LOW PRESSURE SYSTEM AFFECTS THE AREA. && .MARINE... TONIGHT...DETERIORATING MARINE CONDITIONS EXPECTED AS A STRONG...SECONDARY COLD FRONT PUSHES SOUTHWARD THROUGH THE WATERS...MAINLY AFTER MIDNIGHT. WINDS LIKELY TO GUST NEAR ADVISORY LEVELS /25 KT/ BEYOND 20 NM AND THUS WE HAVE RAISED A SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS. SEAS WILL ALSO BUILD BUT BE LIMITED BY THE OFFSHORE WINDS...PROBABLY PEAKING AT 5 FT OUT NEAR 40 NM OFF THE NORTHERN GA COAST. FRIDAY THROUGH TUESDAY...THE PRIMARY WIND SURGE BEHIND THE COLD FRONT WILL OCCUR FRIDAY INTO FRIDAY NIGHT AS COLD NORTHERLY WINDS AFFECT THE WATERS. 20-30 KT GEOSTROPHIC WINDS OVER FAR NORTHEASTERN CHARLESTON WATERS AND THE OFFSHORE GA WATERS JUSTIFY THE ISSUANCE OF A SMALL CRAFT ADVISORY FOR BOTH ZONES DUE TO FREQUENT 25 KT WIND GUSTS. WIND GUSTS ACROSS THE REMAINDER OF THE NEARSHORE WATERS MAY BE CLOSE TO 25 KT AT TIMES...ESPECIALLY FRIDAY NIGHT BUT WILL LET LATER SHIFTS MONITOR MODEL TRENDS. MARINE CONDITIONS IMPROVE GREATLY SATURDAY NIGHT INTO SUNDAY AS THE SURFACE HIGH BUILDS CLOSER TO THE WATERS AND THE GRADIENT RELAXES. A LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL THEN AFFECT THE REGION MONDAY WITH INCREASING SOUTHWESTERLY WINDS IN ADVANCE. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOR GAZ087-088-099>101-114>116-118-137-138. SC...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOR SCZ040-042>045-047>052. MARINE...SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO NOON EST SATURDAY FOR AMZ350. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST SATURDAY FOR AMZ374. && $$ ST
AREA FORECAST DISCUSSION
NWS POCATELLO ID
851 PM MST FRI NOV 14 2014 .UPDATE...HAVE MADE A FEW ADJUSTMENTS THROUGH THE EVENING AS FINAL STAGES OF EARLY WINTER STORM IMPACTS EAST IDAHO. CURRENT RADAR/SAT SHOWS MAIN BAND OF PRECIP STILL IN PLACE OVER SOUTHERN HIGHLANDS. STRATUS THRU SNAKE PLAIN ALONG WITH POCKETS OF DENSE FREEZING FOG ACROSS THE REGION. WEAK BAND OF LIGHT SNOW HAS DEVELOPED IN ROUGHLY THE APPROPRIATE PLACE FOR CONVERGENCE ZONE. PRESSURE FIELD NOT QUITE FAVORABLE BUT MESONET OBSERVATIONS SHOWING SOME CONVERGENCE AT SURFACE. JUST ENOUGH FORCING WITH UPSLOPE FLOW OVER EASTERN HIGHLANDS IN COMBINATION WITH SATURATED LOW LEVELS. MODELS STILL HAVING A HARD TIME WITH THIS BAND. NAM PICKS IT UP AND SAGS IT SOUTH OVERNIGHT INTO THE SOUTHERN HIGHLANDS. LOCAL WRF DID NOT HAVE IT PREVIOUS RUN BUT WAITING ON 00Z TO SEE. HRRR SHOWING WEAK PRECIP NEXT COUPLE HOURS BUT ORGANIZES THE BAND AND STRENGTHENS IT BEFORE DROPPING IT ALONG THE I15 CORRIDOR THROUGH ABOUT SUNRISE. DESPITE HAVING ALLOWED EARLIER ADVISORY FOR SNAKE PLAIN TO EXPIRE...WILL WORK UP A NEW WINTER WX ADVISORY FOR AREAS EXPECTED TO BE IMPACTED BY THIS BAND. ROADS ALREADY ICY FROM PRIOR SNOW /SNOW-RAIN/MELTING AND REFREEZING. A NEW SKIFF OF SNOW ON TOP OF THAT COULD BE DEADLY TO UNSUSPECTING DRIVERS. WITH THAT...WILL EXTEND THE SOUTHERN/EASTERN HIGHLANDS ADVISORY OUT UNTIL 12Z TO CATCH REMNANTS OF CURRENT BAND. DMH && .PREV DISCUSSION... /ISSUED 154 PM MST FRI NOV 14 2014/ SHORT TERM...TODAY THROUGH SATURDAY AFTERNOON. RADAR AND CURRENT OBSERVATIONS SHOW RAIN AND SNOW CONTINUING ACROSS MUCH OF EASTERN IDAHO. WE HAVEN`T RECEIVED ANY REPORTS OF FREEZING RAIN IN SEVERAL HOURS...BUT POCKETS OF IT ARE STILL POSSIBLE ALONG/JUST NORTH OF A WARM FRONT. AS OF 140PM...THAT BOUNDARY EXTENDS ALONG A KINSEY BUTTE-CRATERS-BLACKFOOT-BONE- ANTELOPE FLATS-VICTOR LINE. IT SHOULDN`T MAKE ANY SIGNIFICANT PROGRESS NORTH AS WE ALREADY SEEING COLDER AIR PUSH BACK SOUTH AND EAST NEAR MOUNTAIN HOME AND ALSO ACROSS THE CENTRAL MOUNTAINS. CURRENTLY SOUTH OF THE WARM FRONT...WE HAVE SEEN MORE RAIN THAN SNOW AND WET ROADS. ELSEWHERE...ROADS ARE A MIX OF SNOWCOVERED...SLUSHY AND WET EVEN WITH SNOW FALLING. AS THE COLD FRONT PUSHES ACROSS OVER THE NEXT FEW HOURS...WE WILL SEE A CHANGE BACK TO SNOW. BEHIND IT...LOCAL WIND STUDY INDICATES NEAR WIND ADVISORY LEVEL WIND SPEEDS THAT CONTINUE BEYOND MIDNIGHT. THE AIR MASS BEHIND THE FRONT IS QUITE COLD...INDICATED BY THE SINGLE DIGIT AND LOW TEEN LOWS EXPECTED FOR TONIGHT. SAT AFTERNOON HIGHS WILL STRUGGLE TO REACH 20 DEGREES AT THE SNAKE RIVER PLAIN LEVEL. A HIGH AMPLITUDE RIDGE DEVELOPS ON SATURDAY AND THE BITTER COLD AIR CONTINUES TO FUNNEL INTO THE FORECAST AREA...LOOK FOR MANY BELOW ZERO TEMPERATURES IN THE SNAKE RIVER PLAIN. IN TERMS OF ADDITIONAL SNOWFALL THROUGH THIS EVENING...FOR THE CENTRAL MOUNTAINS EXPECT TRACE AMOUNTS MOST LOCATIONS WITH AN INCH OR SO POSSIBLE NEAR CHALLIS AND ACROSS THE LOST RIVER/PAHSIMEROI REGION. THE SNAKE PLAIN/MAGIC VALLEY WILL SEE ANYWHERE FROM A TRACE TO LOCALLY 2 INCHES AS THE SWITCHOVER OCCURS. THE SOUTHERN HIGHLANDS WILL SEE TRACE AMOUNTS IN THE VALLEYS AND 2-4 INCHES ABOVE 5000FT. THE EASTERN HIGHLANDS CAN EXPECT 1-4 INCHES IN THE VALLEYS AND UP TO 7 IN THE MOUNTAINS. WITH SOME WIND...WE SHOULD SEE SOME POCKETS OF BLOWING/DRIFTING AND REDUCED VISIBILITY. ADDITIONAL AMOUNTS AFTER THAT WILL BE LESS THAN AN INCH GENERALLY EXCEPT FOR PORTIONS OF THE SOUTHERN AND EASTERN HIGHLANDS COULD SEE ANOTHER 1-3 INCHES BEFORE TAPERING OFF QUICKLY LATER SATURDAY. ALL HEADLINES REMAIN IN PLACE WITH THE NEXT UPDATE COMING AT AROUND 5PM. KEYES/MESSICK LONG TERM...SUNDAY THROUGH FRIDAY. A STRONG RIDGE WILL BUILD INTO THE REGION AND WILL KEEP CONDITIONS DRY BUT VERY COLD INTO MIDDLE OF NEXT WEEK. EXPECT VERY SIMILAR TEMPS TO THE RECENT COLD OUTBREAK WITH LOWS IN THE SINGLE DIGITS OR BELOW ZERO AND HIGHS IN THE 20S. MODELS CONTINUE TO HAVE PROBLEMS HANDLING THE NEXT SYSTEM. MAIN PROBLEM IS RUN TO RUN CONTINUITY AS SOME RUNS TRY TO KEEP THE RIDGE INTACT WHILE OTHER RUNS BREAK DOWN THE RIDGE AND ALLOW A SHORTWAVE TO BRING PRECIPITATION INTO THE REGION. CONTINUE TO MENTION LOW CHANCE POPS AT THIS POINT...BUT CHANCES COULD EASILY GO UP OR DOWN WHEN MODELS DEVELOP BETTER AGREEMENT. VALLE AVIATION...A SECOND WAVE OF PRECIPITATION WILL GIVE A GLANCING BLOW TO THE TWO SOUTHERN AIRPORTS...WHILE NORTHERLY COMPONENT WINDS AT KSUN AND KIDA WILL PUT THOSE AIRDROMES IN A PRECIPITATION SHADOW. WINDY CONDITIONS WILL LINGER UNTIL LATE TONIGHT IN THE SNAKE RIVER PLAIN. THE WINDS WILL FORTUNATELY KEEP FOG FROM HAVING A SEVERE IMPACT ON VSBY...AND WHY IT WILL MORE LIKELY BE STRATUS TROUBLE. ALL LOCATIONS THOUGH SHOULD BECOME CIG UNLIMITED BY THE LATE MORNING ON SAT. MESSICK && .PIH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING IDZ022>025. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1210 PM EST THU NOV 13 2014 .SYNOPSIS... ISSUED AT 455 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PERSIST TODAY AND TONIGHT. ACCUMULATIONS OF 1 TO 4 INCHES ARE POSSIBLE THROUGH FRIDAY MORNING IN THE LAKE EFFECT REGION. ELSEWHERE...SCATTERED FLURRIES ARE POSSIBLE AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE UPPER MISSISSIPPI VALLEY. HIGH TEMPERATURES TODAY WILL ONLY BE IN THE LOWER 30S. LOWS TONIGHT WILL ONCE AGAIN BE IN THE 20S. && .UPDATE... ISSUED AT 958 AM EST THU NOV 13 2014 INCREASED SNOW AMOUNTS AND ISSUED A WINTER WX ADVISORY FOR TODAY ACROSS NW ZONES GIVEN RADAR TRENDS/SPOTTER REPORTS/ROAD CLOSERS...ESPECIALLY IN THE SOUTH BEND AREA. ADDED MOISTURE/ASCENT WITH PASSAGE OF MID LEVEL TROUGH AXIS AND EXTREME INSTABILITY HAS BEEN ENOUGH TO OVERCOME DRY LOW LEVELS/POOR FETCH SO FAR THIS MORNING. LATEST NAM BUFR SOUNDINGS ALSO SHOW OMEGA AND SUPERSATURATION WITH RESPECT TO ICE ALIGNED NICELY WITHIN LOWER PART OF DGZ THROUGH THE AFTN FOR DECENT RATIOS/SNOW PRODUCTION. WITH THAT SAID...INCREASE IN LARGE SCALE SUBSIDENCE/DRYING AND DIURNAL CYCLE DISRUPTIONS SHOULD HOPEFULLY SUPPORT LESS ORGANIZATION/IMPACTS AND POTENTIAL FOR A BRIEF LULL BY THIS AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST THU NOV 13 2014 LAKE EFFECT MACHINE FINALLY CRANKING UP EARLY THIS MORNING WITH PASSAGE OF SHORT WAVE TROUGH AND LITTLE COLDER AIR AND SLIGHTLY BETTER FETCH. EXPECT SNOW SHOWERS TO PERSIST THROUGH THE DAY AND TONIGHT ACROSS FAVORED NORTHWEST FLOW COUNTIES. THIS FLOW WILL RESULT IN A MULTI BAND SETUP WITH LIMITED FETCH IN THE 280-300 RANGE. COULD SEE SOME BRIEF INTENSE BANDS TODAY AND TONIGHT AS INVERSION HEIGHTS RISE TO 10KFT AND SFC-850MB DELTA TS NEAR 20C AND SFC-700MB NEAR 30C. FOLLOWING HIRES RAP AND HRRR GUIDANCE FOR TODAY EXPECT TO SEE MULTIBANDS PRODUCE GENERAL 1 TO 2 INCH AMOUNTS. SIMILAR AMOUNTS TONIGHT AS WELL FOR A TOTAL OF 2 TO 4 INCHES BY EARLY FRIDAY MORNING. EXPECT SURFACE PAVEMENT TEMPS TO RISE ABOVE FREEZING TODAY WITH AIR TEMPS NEAR OR JUST BELOW FREEZING. THIS SHOULD KEEP MAIN ROADS WET WITH POSSIBLE ICY SPOTS RATHER THAN SNOW COVERED. AS TEMPS FALL THIS EVENING...REMAINING SNOW BANDS SHOULD START TO PRODUCE A COVERING ON ALL SURFACES. HAVE OPTED TO HOLD OFF ON ANY ADVISORY HEADLINES WITH THIS PACKAGE WITH MOST CONCERN FOCUSED ON TONIGHT PERIOD WITH COLDER TEMPS AND ROADS THEN BECOMING SNOW COVERED AND SLICK. WILL DEFER ANY HEADLINES FOR TONIGHT TO DAY SHIFT WITH FURTHER MONITORING OF WHERE BANDS PERSIST. WILL ISSUE A SPECIAL WEATHER STATEMENT TO MENTION POSSIBLE ICY CONDITIONS THIS MORNING WITH ACCUMULATING SNOW. VERY COLD TEMPERATURES TODAY WITH HIGHS NEAR OR BELOW FREEZING...ABOUT 20 DEGREES BELOW NORMAL. LOWS TONIGHT WILL AGAIN BE DOWN TO AROUND 20 FAR SOUTH WHERE SOME PARTIAL CLEARING POSSIBLE AND IN THE MIDDLE TO UPPER 20S NORTH UNDER LAKE CLOUDS. && .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 450 AM EST THU NOV 13 2014 AMAZING HIGH LATITUDE BLOCK UPSTREAM WITH A FULL 4 STANDARDIZED DEVIATIONS/ANOMALIES PER PAST CLIMATE WAS HELPING TO INSURE TEMPERATURES WILL STAY WELL BELOW NORMAL DOWNSTREAM INCLUDING THE WESTERN GREAT LAKES REGION. INHERENT WITH THIS PATTERN ARE LAKE EFFECT SNOW CHALLENGES WITH ACCOMPANYING NEARLY FRIGID AIR AS DELTA T VALUES RANGE FROM 18C TO 25C FOR THE ENTIRE LONG TERM PERIOD. INVERSION HEIGHTS WILL FALL FRIDAY...CAUSING LAKE EFFECT SNOW SHOWERS TO DIMINISH AND EVENTUALLY BUT TEMPORARILY END. SOME LIGHT SYSTEM SNOW IS EXPECTED SATURDAY NIGHT AS AN UPPER LEVEL TROF MOVES ACROSS THE AREA. USING THE GARCIA METHOD ON THE 285K/GFS SURFACE YIELDS AROUND AN INCH OF SNOW BY SUNDAY MORNING. A SECOND ARCTIC SURGE OF EVEN COLDER AIR WILL CREATE FAVORABLE CONDITIONS FOR MORE LAKE EFFECT SNOW EARLY NEXT WEEK. HAVE INCREASED LAKE EFFECT SNOW CHANCES MONDAY THROUGH WEDNESDAY AS INVERSION HEIGHTS RISE AND THE FETCH BECOMES MORE FAVORABLE FOR SNOW SHOWERS. GFS/BUFKIT INDICATES THE EQUILIBRIUM LEVEL OF LAKE INDUCED CAPE RISING TO 10K FEET WITH THE DENDRITIC GROWTH ZONE OVERLAYING THE CLOUD LAYER. GIVEN THE FETCH...MORE OF A MULTI/BAND EVENT IS EXPECTED IN LIEU OF A SINGLE BAND. AS FOR TEMPERATURES...ONGOING HIGHS OF GENERALLY 29F TO 35F FRIDAY THROUGH SUNDAY FOLLOWED BY HIGHS IN THE MID TO UPPER 20S MONDAY AND TUESDAY APPEAR ON TRACK. THE COLDEST HIGH RECORD FOR TUESDAY AT FT WAYNE NOVEMBER 18 IS 26F. HAVE LOWERED THE HIGH TO 26F...THE CANADIAN GEM EPS GRAM AND ECMWF TEMPERATURE GUIDANCE SUPPORTS HIGHS OF ONLY 22F TO 24F. 850 MB TEMPS SHOULD BE CLOSE TO -18C TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1209 PM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS AND CIGS RANGING BTW HIGH MVFR-LOW VFR WILL CONTINUE TO IMPACT NORTHERN INDIANA THROUGH THE FORECAST PERIOD. GREATEST IMPACT FROM THE SNOW SHOWER ACTIVITY WILL CONTINUE TO BE AT KSBN WHERE VISIBILITIES WILL BE HIGHLY VARIABLE THROUGH THE PERIOD. KFWA WILL ALSO SEE A FEW FLURRIES/SNOW SHOWERS MAINLY THIS AFTN WHICH MAY BRIEFLY REDUCE VISIBILITIES. OTHERWISE...WNW WINDS 10-16 KTS THIS AFTN WILL LESSEN TO BTW 6-12 KTS TONIGHT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR INZ003>005. MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ077>079. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST FRIDAY FOR LMZ043-046. && $$ UPDATE...STEINWEDEL SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...STEINWEDEL 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
959 AM EST THU NOV 13 2014 .SYNOPSIS... ISSUED AT 455 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PERSIST TODAY AND TONIGHT. ACCUMULATIONS OF 1 TO 4 INCHES ARE POSSIBLE THROUGH FRIDAY MORNING IN THE LAKE EFFECT REGION. ELSEWHERE...SCATTERED FLURRIES ARE POSSIBLE AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE UPPER MISSISSIPPI VALLEY. HIGH TEMPERATURES TODAY WILL ONLY BE IN THE LOWER 30S. LOWS TONIGHT WILL ONCE AGAIN BE IN THE 20S. && .UPDATE... ISSUED AT 958 AM EST THU NOV 13 2014 INCREASED SNOW AMOUNTS AND ISSUED A WINTER WX ADVISORY FOR TODAY ACROSS NW ZONES GIVEN RADAR TRENDS/SPOTTER REPORTS/ROAD CLOSERS...ESPECIALLY IN THE SOUTH BEND AREA. ADDED MOISTURE/ASCENT WITH PASSAGE OF MID LEVEL TROUGH AXIS AND EXTREME INSTABILITY HAS BEEN ENOUGH TO OVERCOME DRY LOW LEVELS/POOR FETCH SO FAR THIS MORNING. LATEST NAM BUFR SOUNDINGS ALSO SHOW OMEGA AND SUPERSATURATION WITH RESPECT TO ICE ALIGNED NICELY WITHIN LOWER PART OF DGZ THROUGH THE AFTN FOR DECENT RATIOS/SNOW PRODUCTION. WITH THAT SAID...INCREASE IN LARGE SCALE SUBSIDENCE/DRYING AND DIURNAL CYCLE DISRUPTIONS SHOULD HOPEFULLY SUPPORT LESS ORGANIZATION/IMPACTS AND POTENTIAL FOR A BRIEF LULL BY THIS AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST THU NOV 13 2014 LAKE EFFECT MACHINE FINALLY CRANKING UP EARLY THIS MORNING WITH PASSAGE OF SHORT WAVE TROUGH AND LITTLE COLDER AIR AND SLIGHTLY BETTER FETCH. EXPECT SNOW SHOWERS TO PERSIST THROUGH THE DAY AND TONIGHT ACROSS FAVORED NORTHWEST FLOW COUNTIES. THIS FLOW WILL RESULT IN A MULTI BAND SETUP WITH LIMITED FETCH IN THE 280-300 RANGE. COULD SEE SOME BRIEF INTENSE BANDS TODAY AND TONIGHT AS INVERSION HEIGHTS RISE TO 10KFT AND SFC-850MB DELTA TS NEAR 20C AND SFC-700MB NEAR 30C. FOLLOWING HIRES RAP AND HRRR GUIDANCE FOR TODAY EXPECT TO SEE MULTIBANDS PRODUCE GENERAL 1 TO 2 INCH AMOUNTS. SIMILAR AMOUNTS TONIGHT AS WELL FOR A TOTAL OF 2 TO 4 INCHES BY EARLY FRIDAY MORNING. EXPECT SURFACE PAVEMENT TEMPS TO RISE ABOVE FREEZING TODAY WITH AIR TEMPS NEAR OR JUST BELOW FREEZING. THIS SHOULD KEEP MAIN ROADS WET WITH POSSIBLE ICY SPOTS RATHER THAN SNOW COVERED. AS TEMPS FALL THIS EVENING...REMAINING SNOW BANDS SHOULD START TO PRODUCE A COVERING ON ALL SURFACES. HAVE OPTED TO HOLD OFF ON ANY ADVISORY HEADLINES WITH THIS PACKAGE WITH MOST CONCERN FOCUSED ON TONIGHT PERIOD WITH COLDER TEMPS AND ROADS THEN BECOMING SNOW COVERED AND SLICK. WILL DEFER ANY HEADLINES FOR TONIGHT TO DAY SHIFT WITH FURTHER MONITORING OF WHERE BANDS PERSIST. WILL ISSUE A SPECIAL WEATHER STATEMENT TO MENTION POSSIBLE ICY CONDITIONS THIS MORNING WITH ACCUMULATING SNOW. VERY COLD TEMPERATURES TODAY WITH HIGHS NEAR OR BELOW FREEZING...ABOUT 20 DEGREES BELOW NORMAL. LOWS TONIGHT WILL AGAIN BE DOWN TO AROUND 20 FAR SOUTH WHERE SOME PARTIAL CLEARING POSSIBLE AND IN THE MIDDLE TO UPPER 20S NORTH UNDER LAKE CLOUDS. && .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 450 AM EST THU NOV 13 2014 AMAZING HIGH LATITUDE BLOCK UPSTREAM WITH A FULL 4 STANDARDIZED DEVIATIONS/ANOMALIES PER PAST CLIMATE WAS HELPING TO INSURE TEMPERATURES WILL STAY WELL BELOW NORMAL DOWNSTREAM INCLUDING THE WESTERN GREAT LAKES REGION. INHERENT WITH THIS PATTERN ARE LAKE EFFECT SNOW CHALLENGES WITH ACCOMPANYING NEARLY FRIGID AIR AS DELTA T VALUES RANGE FROM 18C TO 25C FOR THE ENTIRE LONG TERM PERIOD. INVERSION HEIGHTS WILL FALL FRIDAY...CAUSING LAKE EFFECT SNOW SHOWERS TO DIMINISH AND EVENTUALLY BUT TEMPORARILY END. SOME LIGHT SYSTEM SNOW IS EXPECTED SATURDAY NIGHT AS AN UPPER LEVEL TROF MOVES ACROSS THE AREA. USING THE GARCIA METHOD ON THE 285K/GFS SURFACE YIELDS AROUND AN INCH OF SNOW BY SUNDAY MORNING. A SECOND ARCTIC SURGE OF EVEN COLDER AIR WILL CREATE FAVORABLE CONDITIONS FOR MORE LAKE EFFECT SNOW EARLY NEXT WEEK. HAVE INCREASED LAKE EFFECT SNOW CHANCES MONDAY THROUGH WEDNESDAY AS INVERSION HEIGHTS RISE AND THE FETCH BECOMES MORE FAVORABLE FOR SNOW SHOWERS. GFS/BUFKIT INDICATES THE EQUILIBRIUM LEVEL OF LAKE INDUCED CAPE RISING TO 10K FEET WITH THE DENDRITIC GROWTH ZONE OVERLAYING THE CLOUD LAYER. GIVEN THE FETCH...MORE OF A MULTI/BAND EVENT IS EXPECTED IN LIEU OF A SINGLE BAND. AS FOR TEMPERATURES...ONGOING HIGHS OF GENERALLY 29F TO 35F FRIDAY THROUGH SUNDAY FOLLOWED BY HIGHS IN THE MID TO UPPER 20S MONDAY AND TUESDAY APPEAR ON TRACK. THE COLDEST HIGH RECORD FOR TUESDAY AT FT WAYNE NOVEMBER 18 IS 26F. HAVE LOWERED THE HIGH TO 26F...THE CANADIAN GEM EPS GRAM AND ECMWF TEMPERATURE GUIDANCE SUPPORTS HIGHS OF ONLY 22F TO 24F. 850 MB TEMPS SHOULD BE CLOSE TO -18C TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 629 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS ONGOING AND WILL CONTINUE THROUGH THE PERIOD AT KSBN. VISIBILITIES WILL VARY DEPENDING ON WHEN THE BANDS MOVE OVER THE AIRPORT. WILL HAVE A TEMPO GROUP TO START THE PERIOD WITH IFR POSSIBLE. BANDS SHOULD WANE A LITTLE LATER IN THE DAY BUT EXPECT ADDITIONAL TEMPO GROUP WILL BE NEEDED LATE MORNING INTO AFTERNOON. SECOND WAVE EXPECTED THIS EVENING AND WILL BRING ADDITIONAL SNOW SHOWERS OVERNIGHT. KFWA WILL SEE SOME LIGHT SNOW SHOWERS OR FLURRIES AS A SHORT WAVE PASSES THROUGH. THEY ALSO MAY SEE THE TAIL END OF SOME LAKE BANDS. TOO MUCH UNCERTAINTY FOR VIS RESTRICTIONS AT THIS TIME BUT EXPECT SOME MVFR CIGS TO DEVELOP AND MOVE IN LATER THIS MORNING WITH FLOW OFF THE LAKE. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR INZ003>005. MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ077>079. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST FRIDAY FOR LMZ043-046. && $$ UPDATE...STEINWEDEL 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
727 AM EST THU NOV 13 2014 .SYNOPSIS... ISSUED AT 455 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PERSIST TODAY AND TONIGHT. ACCUMULATIONS OF 1 TO 4 INCHES ARE POSSIBLE THROUGH FRIDAY MORNING IN THE LAKE EFFECT REGION. ELSEWHERE...SCATTERED FLURRIES ARE POSSIBLE AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE UPPER MISSISSIPPI VALLEY. HIGH TEMPERATURES TODAY WILL ONLY BE IN THE LOWER 30S. LOWS TONIGHT WILL ONCE AGAIN BE IN THE 20S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST THU NOV 13 2014 LAKE EFFECT MACHINE FINALLY CRANKING UP EARLY THIS MORNING WITH PASSAGE OF SHORT WAVE TROUGH AND LITTLE COLDER AIR AND SLIGHTLY BETTER FETCH. EXPECT SNOW SHOWERS TO PERSIST THROUGH THE DAY AND TONIGHT ACROSS FAVORED NORTHWEST FLOW COUNTIES. THIS FLOW WILL RESULT IN A MULTI BAND SETUP WITH LIMITED FETCH IN THE 280-300 RANGE. COULD SEE SOME BRIEF INTENSE BANDS TODAY AND TONIGHT AS INVERSION HEIGHTS RISE TO 10KFT AND SFC-850MB DELTA TS NEAR 20C AND SFC-700MB NEAR 30C. FOLLOWING HIRES RAP AND HRRR GUIDANCE FOR TODAY EXPECT TO SEE MULTIBANDS PRODUCE GENERAL 1 TO 2 INCH AMOUNTS. SIMILAR AMOUNTS TONIGHT AS WELL FOR A TOTAL OF 2 TO 4 INCHES BY EARLY FRIDAY MORNING. EXPECT SURFACE PAVEMENT TEMPS TO RISE ABOVE FREEZING TODAY WITH AIR TEMPS NEAR OR JUST BELOW FREEZING. THIS SHOULD KEEP MAIN ROADS WET WITH POSSIBLE ICY SPOTS RATHER THAN SNOW COVERED. AS TEMPS FALL THIS EVENING...REMAINING SNOW BANDS SHOULD START TO PRODUCE A COVERING ON ALL SURFACES. HAVE OPTED TO HOLD OFF ON ANY ADVISORY HEADLINES WITH THIS PACKAGE WITH MOST CONCERN FOCUSED ON TONIGHT PERIOD WITH COLDER TEMPS AND ROADS THEN BECOMING SNOW COVERED AND SLICK. WILL DEFER ANY HEADLINES FOR TONIGHT TO DAY SHIFT WITH FURTHER MONITORING OF WHERE BANDS PERSIST. WILL ISSUE A SPECIAL WEATHER STATEMENT TO MENTION POSSIBLE ICY CONDITIONS THIS MORNING WITH ACCUMULATING SNOW. VERY COLD TEMPERATURES TODAY WITH HIGHS NEAR OR BELOW FREEZING...ABOUT 20 DEGREES BELOW NORMAL. LOWS TONIGHT WILL AGAIN BE DOWN TO AROUND 20 FAR SOUTH WHERE SOME PARTIAL CLEARING POSSIBLE AND IN THE MIDDLE TO UPPER 20S NORTH UNDER LAKE CLOUDS. && .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 450 AM EST THU NOV 13 2014 AMAZING HIGH LATITUDE BLOCK UPSTREAM WITH A FULL 4 STANDARDIZED DEVIATIONS/ANOMALIES PER PAST CLIMATE WAS HELPING TO INSURE TEMPERATURES WILL STAY WELL BELOW NORMAL DOWNSTREAM INCLUDING THE WESTERN GREAT LAKES REGION. INHERENT WITH THIS PATTERN ARE LAKE EFFECT SNOW CHALLENGES WITH ACCOMPANYING NEARLY FRIGID AIR AS DELTA T VALUES RANGE FROM 18C TO 25C FOR THE ENTIRE LONG TERM PERIOD. INVERSION HEIGHTS WILL FALL FRIDAY...CAUSING LAKE EFFECT SNOW SHOWERS TO DIMINISH AND EVENTUALLY BUT TEMPORARILY END. SOME LIGHT SYSTEM SNOW IS EXPECTED SATURDAY NIGHT AS AN UPPER LEVEL TROF MOVES ACROSS THE AREA. USING THE GARCIA METHOD ON THE 285K/GFS SURFACE YIELDS AROUND AN INCH OF SNOW BY SUNDAY MORNING. A SECOND ARCTIC SURGE OF EVEN COLDER AIR WILL CREATE FAVORABLE CONDITIONS FOR MORE LAKE EFFECT SNOW EARLY NEXT WEEK. HAVE INCREASED LAKE EFFECT SNOW CHANCES MONDAY THROUGH WEDNESDAY AS INVERSION HEIGHTS RISE AND THE FETCH BECOMES MORE FAVORABLE FOR SNOW SHOWERS. GFS/BUFKIT INDICATES THE EQUILIBRIUM LEVEL OF LAKE INDUCED CAPE RISING TO 10K FEET WITH THE DENDRITIC GROWTH ZONE OVERLAYING THE CLOUD LAYER. GIVEN THE FETCH...MORE OF A MULTI/BAND EVENT IS EXPECTED IN LIEU OF A SINGLE BAND. AS FOR TEMPERATURES...ONGOING HIGHS OF GENERALLY 29F TO 35F FRIDAY THROUGH SUNDAY FOLLOWED BY HIGHS IN THE MID TO UPPER 20S MONDAY AND TUESDAY APPEAR ON TRACK. THE COLDEST HIGH RECORD FOR TUESDAY AT FT WAYNE NOVEMBER 18 IS 26F. HAVE LOWERED THE HIGH TO 26F...THE CANADIAN GEM EPS GRAM AND ECMWF TEMPERATURE GUIDANCE SUPPORTS HIGHS OF ONLY 22F TO 24F. 850 MB TEMPS SHOULD BE CLOSE TO -18C TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 629 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS ONGOING AND WILL CONTINUE THROUGH THE PERIOD AT KSBN. VISIBILITIES WILL VARY DEPENDING ON WHEN THE BANDS MOVE OVER THE AIRPORT. WILL HAVE A TEMPO GROUP TO START THE PERIOD WITH IFR POSSIBLE. BANDS SHOULD WANE A LITTLE LATER IN THE DAY BUT EXPECT ADDITIONAL TEMPO GROUP WILL BE NEEDED LATE MORNING INTO AFTERNOON. SECOND WAVE EXPECTED THIS EVENING AND WILL BRING ADDITIONAL SNOW SHOWERS OVERNIGHT. KFWA WILL SEE SOME LIGHT SNOW SHOWERS OR FLURRIES AS A SHORT WAVE PASSES THROUGH. THEY ALSO MAY SEE THE TAIL END OF SOME LAKE BANDS. TOO MUCH UNCERTAINTY FOR VIS RESTRICTIONS AT THIS TIME BUT EXPECT SOME MVFR CIGS TO DEVELOP AND MOVE IN LATER THIS MORNING WITH FLOW OFF THE LAKE. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST FRIDAY FOR LMZ043-046. && $$ 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
637 AM EST THU NOV 13 2014 .SYNOPSIS... ISSUED AT 455 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PERSIST TODAY AND TONIGHT. ACCUMULATIONS OF 1 TO 4 INCHES ARE POSSIBLE THROUGH FRIDAY MORNING IN THE LAKE EFFECT REGION. ELSEWHERE...SCATTERED FLURRIES ARE POSSIBLE AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE UPPER MISSISSIPPI VALLEY. HIGH TEMPERATURES TODAY WILL ONLY BE IN THE LOWER 30S. LOWS TONIGHT WILL ONCE AGAIN BE IN THE 20S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST THU NOV 13 2014 LAKE EFFECT MACHINE FINALLY CRANKING UP EARLY THIS MORNING WITH PASSAGE OF SHORT WAVE TROUGH AND LITTLE COLDER AIR AND SLIGHTLY BETTER FETCH. EXPECT SNOW SHOWERS TO PERSIST THROUGH THE DAY AND TONIGHT ACROSS FAVORED NORTHWEST FLOW COUNTIES. THIS FLOW WILL RESULT IN A MULTI BAND SETUP WITH LIMITED FETCH IN THE 280-300 RANGE. COULD SEE SOME BRIEF INTENSE BANDS TODAY AND TONIGHT AS INVERSION HEIGHTS RISE TO 10KFT AND SFC-850MB DELTA TS NEAR 20C AND SFC-700MB NEAR 30C. FOLLOWING HIRES RAP AND HRRR GUIDANCE FOR TODAY EXPECT TO SEE MULTIBANDS PRODUCE GENERAL 1 TO 2 INCH AMOUNTS. SIMILAR AMOUNTS TONIGHT AS WELL FOR A TOTAL OF 2 TO 4 INCHES BY EARLY FRIDAY MORNING. EXPECT SURFACE PAVEMENT TEMPS TO RISE ABOVE FREEZING TODAY WITH AIR TEMPS NEAR OR JUST BELOW FREEZING. THIS SHOULD KEEP MAIN ROADS WET WITH POSSIBLE ICY SPOTS RATHER THAN SNOW COVERED. AS TEMPS FALL THIS EVENING...REMAINING SNOW BANDS SHOULD START TO PRODUCE A COVERING ON ALL SURFACES. HAVE OPTED TO HOLD OFF ON ANY ADVISORY HEADLINES WITH THIS PACKAGE WITH MOST CONCERN FOCUSED ON TONIGHT PERIOD WITH COLDER TEMPS AND ROADS THEN BECOMING SNOW COVERED AND SLICK. WILL DEFER ANY HEADLINES FOR TONIGHT TO DAY SHIFT WITH FURTHER MONITORING OF WHERE BANDS PERSIST. WILL ISSUE A SPECIAL WEATHER STATEMENT TO MENTION POSSIBLE ICY CONDITIONS THIS MORNING WITH ACCUMULATING SNOW. VERY COLD TEMPERATURES TODAY WITH HIGHS NEAR OR BELOW FREEZING...ABOUT 20 DEGREES BELOW NORMAL. LOWS TONIGHT WILL AGAIN BE DOWN TO AROUND 20 FAR SOUTH WHERE SOME PARTIAL CLEARING POSSIBLE AND IN THE MIDDLE TO UPPER 20S NORTH UNDER LAKE CLOUDS. && .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 450 AM EST THU NOV 13 2014 AMAZING HIGH LATITUDE BLOCK UPSTREAM WITH A FULL 4 STANDARDIZED DEVIATIONS/ANOMALIES PER PAST CLIMATE WAS HELPING TO INSURE TEMPERATURES WILL STAY WELL BELOW NORMAL DOWNSTREAM INCLUDING THE WESTERN GREAT LAKES REGION. INHERENT WITH THIS PATTERN ARE LAKE EFFECT SNOW CHALLENGES WITH ACCOMPANYING NEARLY FRIGID AIR AS DELTA T VALUES RANGE FROM 18C TO 25C FOR THE ENTIRE LONG TERM PERIOD. INVERSION HEIGHTS WILL FALL FRIDAY...CAUSING LAKE EFFECT SNOW SHOWERS TO DIMINISH AND EVENTUALLY BUT TEMPORARILY END. SOME LIGHT SYSTEM SNOW IS EXPECTED SATURDAY NIGHT AS AN UPPER LEVEL TROF MOVES ACROSS THE AREA. USING THE GARCIA METHOD ON THE 285K/GFS SURFACE YIELDS AROUND AN INCH OF SNOW BY SUNDAY MORNING. A SECOND ARCTIC SURGE OF EVEN COLDER AIR WILL CREATE FAVORABLE CONDITIONS FOR MORE LAKE EFFECT SNOW EARLY NEXT WEEK. HAVE INCREASED LAKE EFFECT SNOW CHANCES MONDAY THROUGH WEDNESDAY AS INVERSION HEIGHTS RISE AND THE FETCH BECOMES MORE FAVORABLE FOR SNOW SHOWERS. GFS/BUFKIT INDICATES THE EQUILIBRIUM LEVEL OF LAKE INDUCED CAPE RISING TO 10K FEET WITH THE DENDRITIC GROWTH ZONE OVERLAYING THE CLOUD LAYER. GIVEN THE FETCH...MORE OF A MULTI/BAND EVENT IS EXPECTED IN LIEU OF A SINGLE BAND. AS FOR TEMPERATURES...ONGOING HIGHS OF GENERALLY 29F TO 35F FRIDAY THROUGH SUNDAY FOLLOWED BY HIGHS IN THE MID TO UPPER 20S MONDAY AND TUESDAY APPEAR ON TRACK. THE COLDEST HIGH RECORD FOR TUESDAY AT FT WAYNE NOVEMBER 18 IS 26F. HAVE LOWERED THE HIGH TO 26F...THE CANADIAN GEM EPS GRAM AND ECMWF TEMPERATURE GUIDANCE SUPPORTS HIGHS OF ONLY 22F TO 24F. 850 MB TEMPS SHOULD BE CLOSE TO -18C TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 629 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS ONGOING AND WILL CONTINUE THROUGH THE PERIOD AT KSBN. VISIBILITIES WILL VARY DEPENDING ON WHEN THE BANDS MOVE OVER THE AIRPORT. WILL HAVE A TEMPO GROUP TO START THE PERIOD WITH IFR POSSIBLE. BANDS SHOULD WANE A LITTLE LATER IN THE DAY BUT EXPECT ADDITIONAL TEMPO GROUP WILL BE NEEDED LATE MORNING INTO AFTERNOON. SECOND WAVE EXPECTED THIS EVENING AND WILL BRING ADDITIONAL SNOW SHOWERS OVERNIGHT. KFWA WILL SEE SOME LIGHT SNOW SHOWERS OR FLURRIES AS A SHORT WAVE PASSES THROUGH. THEY ALSO MAY SEE THE TAIL END OF SOME LAKE BANDS. TOO MUCH UNCERTAINTY FOR VIS RESTRICTIONS AT THIS TIME BUT EXPECT SOME MVFR CIGS TO DEVELOP AND MOVE IN LATER THIS MORNING WITH FLOW OFF THE LAKE. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST FRIDAY FOR LMZ043-046. && $$ 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
456 AM EST THU NOV 13 2014 .SYNOPSIS... ISSUED AT 455 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PERSIST TODAY AND TONIGHT. ACCUMULATIONS OF 1 TO 4 INCHES ARE POSSIBLE THROUGH FRIDAY MORNING IN THE LAKE EFFECT REGION. ELSEWHERE...SCATTERED FLURRIES ARE POSSIBLE AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE UPPER MISSISSIPPI VALLEY. HIGH TEMPERATURES TODAY WILL ONLY BE IN THE LOWER 30S. LOWS TONIGHT WILL ONCE AGAIN BE IN THE 20S. .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM EST THU NOV 13 2014 LAKE EFFECT MACHINE FINALLY CRANKING UP EARLY THIS MORNING WITH PASSAGE OF SHORT WAVE TROUGH AND LITTLE COLDER AIR AND SLIGHTLY BETTER FETCH. EXPECT SNOW SHOWERS TO PERSIST THROUGH THE DAY AND TONIGHT ACROSS FAVORED NORTHWEST FLOW COUNTIES. THIS FLOW WILL RESULT IN A MULTI BAND SETUP WITH LIMITED FETCH IN THE 280-300 RANGE. COULD SEE SOME BRIEF INTENSE BANDS TODAY AND TONIGHT AS INVERSION HEIGHTS RISE TO 10KFT AND SFC-850MB DELTA TS NEAR 20C AND SFC-700MB NEAR 30C. FOLLOWING HIRES RAP AND HRRR GUIDANCE FOR TODAY EXPECT TO SEE MULTIBANDS PRODUCE GENERAL 1 TO 2 INCH AMOUNTS. SIMILAR AMOUNTS TONIGHT AS WELL FOR A TOTAL OF 2 TO 4 INCHES BY EARLY FRIDAY MORNING. EXPECT SURFACE PAVEMENT TEMPS TO RISE ABOVE FREEZING TODAY WITH AIR TEMPS NEAR OR JUST BELOW FREEZING. THIS SHOULD KEEP MAIN ROADS WET WITH POSSIBLE ICY SPOTS RATHER THAN SNOW COVERED. AS TEMPS FALL THIS EVENING...REMAINING SNOW BANDS SHOULD START TO PRODUCE A COVERING ON ALL SURFACES. HAVE OPTED TO HOLD OFF ON ANY ADVISORY HEADLINES WITH THIS PACKAGE WITH MOST CONCERN FOCUSED ON TONIGHT PERIOD WITH COLDER TEMPS AND ROADS THEN BECOMING SNOW COVERED AND SLICK. WILL DEFER ANY HEADLINES FOR TONIGHT TO DAY SHIFT WITH FURTHER MONITORING OF WHERE BANDS PERSIST. WILL ISSUE A SPECIAL WEATHER STATEMENT TO MENTION POSSIBLE ICY CONDITIONS THIS MORNING WITH ACCUMULATING SNOW. VERY COLD TEMPERATURES TODAY WITH HIGHS NEAR OR BELOW FREEZING...ABOUT 20 DEGREES BELOW NORMAL. LOWS TONIGHT WILL AGAIN BE DOWN TO AROUND 20 FAR SOUTH WHERE SOME PARTIAL CLEARING POSSIBLE AND IN THE MIDDLE TO UPPER 20S NORTH UNDER LAKE CLOUDS. && .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 450 AM EST THU NOV 13 2014 AMAZING HIGH LATITUDE BLOCK UPSTREAM WITH A FULL 4 STANDARDIZED DEVIATIONS/ANOMALIES PER PAST CLIMATE WAS HELPING TO INSURE TEMPERATURES WILL STAY WELL BELOW NORMAL DOWNSTREAM INCLUDING THE WESTERN GREAT LAKES REGION. INHERENT WITH THIS PATTERN ARE LAKE EFFECT SNOW CHALLENGES WITH ACCOMPANYING NEARLY FRIGID AIR AS DELTA T VALUES RANGE FROM 18C TO 25C FOR THE ENTIRE LONG TERM PERIOD. INVERSION HEIGHTS WILL FALL FRIDAY...CAUSING LAKE EFFECT SNOW SHOWERS TO DIMINISH AND EVENTUALLY BUT TEMPORARILY END. SOME LIGHT SYSTEM SNOW IS EXPECTED SATURDAY NIGHT AS AN UPPER LEVEL TROF MOVES ACROSS THE AREA. USING THE GARCIA METHOD ON THE 285K/GFS SURFACE YIELDS AROUND AN INCH OF SNOW BY SUNDAY MORNING. A SECOND ARCTIC SURGE OF EVEN COLDER AIR WILL CREATE FAVORABLE CONDITIONS FOR MORE LAKE EFFECT SNOW EARLY NEXT WEEK. HAVE INCREASED LAKE EFFECT SNOW CHANCES MONDAY THROUGH WEDNESDAY AS INVERSION HEIGHTS RISE AND THE FETCH BECOMES MORE FAVORABLE FOR SNOW SHOWERS. GFS/BUFKIT INDICATES THE EQUILIBRIUM LEVEL OF LAKE INDUCED CAPE RISING TO 10K FEET WITH THE DENDRITIC GROWTH ZONE OVERLAYING THE CLOUD LAYER. GIVEN THE FETCH...MORE OF A MULTI/BAND EVENT IS EXPECTED IN LIEU OF A SINGLE BAND. AS FOR TEMPERATURES...ONGOING HIGHS OF GENERALLY 29F TO 25F FRIDAY THROUGH SUNDAY FOLLOWED BY HIGHS IN THE MID TO UPPER 20S MONDAY AND TUESDAY APPEAR ON TRACK. THE COLDEST HIGH RECORD FOR TUESDAY AT FT WAYNE NOVEMBER 18 IS 26F. HAVE LOWERED THE HIGH TO 26F...THE CANADIAN GEM EPS GRAM AND ECMWF TEMPERATURE GUIDANCE SUPPORTS HIGHS OF ONLY 22F TO 24F. 850 MB TEMPS SHOULD BE CLOSE TO -18C TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1224 AM EST THU NOV 13 2014 NARROW BAND OF LIGHT SNOW HAS FORMED JUST WEST OF KFWA AND MAY CLIP THIS SITE NEXT FEW HOURS. OBSERVATIONS UPSTREAM HAVE BEEN IN THE 2-3SM MILE RANGE WITH LIGHT SNOW BUT KEPT KFWA MVFR AS LOWER RESTRICTIONS WOULD BE BRIEF IF THEY OCCUR AT ALL. OTHERWISE CIGS HOVERING AROUND THE 3KFT RANGE. LAKE EFFECT SNOW SHOWERS TO INCREASE LATER AS WINDS VEER SLIGHTLY AND COLDER AIR ARRIVES. KEPT KSBN TAF IN THE MVFR RANGE BUT ANY STRONGER BANDS COULD PRODUCE BRIEF IFR VISIBILITIES. WILL HAVE TO MONITOR DEVELOPMENT FOR UPDATES AS LOCATION UNCERTAIN AT THIS TIME. LAKE EFFECT TO CONTINUE OFF AND ON TODAY AND TONIGHT BUT MAY SEE A BRIEF LULL LATE TODAY AHEAD OF ANOTHER SHORT WAVE TO MOVE THROUGH THIS EVENING. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST FRIDAY FOR LMZ043-046. && $$ SYNOPSIS...MARSILI 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
1128 AM CST THU NOV 13 2014 .UPDATE... ISSUED AT 1123 AM CST THU NOV 13 2014 SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO THE FORECAST. WEB CAMS INDICATE A VERY MINOR ACCUMULATION IN THE DBQ AREA. AS SUCH THE MINOR SNOWFALL AMOUNTS HAVE BEEN INCREASED A FEW TENTHS OF AN INCH FOR THE AFTERNOON HOURS. RAP TRENDS CONTINUE TO INDICATE MORE SNOW SHOWERS DURING THE AFTERNOON LIKELY DURING THE MAXIMUM HEATING THAT CAN OCCUR THIS AFTERNOON. UPDATE ISSUED AT 1016 AM CST THU NOV 13 2014 A SIGNIFICANT REVISION HAS BEEN MADE TO THE FORECAST. RADAR HAS FLURRIES AND SNOW SHOWERS ACROSS THE AREA IN ADVANCE OF THE APPROACHING UPPER LEVEL DISTURBANCE. FORCING AND LIMITED DAYTIME HEATING HAS CREATED NEW CLOUDS WITH AN INCREASE IN COVERAGE OF THE FLURRIES AND SNOW SHOWERS. IF TRENDS WITH THE RAP MODEL ARE CORRECT...SOME OF THE SNOW SHOWERS SHOULD GET FAIRLY STRONG LATE THIS MORNING AND EARLY AFTERNOON WITH THE POTENTIAL FOR MINOR ACCUMULATIONS IN SOME LOCATIONS. && .SYNOPSIS... ISSUED AT 345 AM CST THU NOV 13 2014 LOWER CLOUDS HAVE ENVELOPED MUCH OF CWA FROM NORTH TO SOUTH WITH APPROACH OF SHEARING UPPER LEVEL WAVE. OCCASIONAL FLURRIES ALSO CONTINUE WITH SOME LIGHT SNOW SHOWERS PORTIONS OF SOUTHERN MN INTO NORTHERN IA BRIEFLY REDUCING VSBYS TO AROUND 2-5SM. SFC ANALYSIS SHOWS IMPRESSIVE AND ANOMALOUSLY STRONG ANTICYCLONE OF 1045+ MB OVER PORTIONS OF NORTHERN ROCKIES... WITH COUPLE OF WEAK TROUGHS OR WIND SHIFTS NOTED UPSTREAM ATTENDANT TO UPPER LEVEL DISTURBANCES BEING SHUTTLED DOWN IN CYCLONIC FLOW. ITS STILL COLD... WITH 00Z DVN RAOB 850 TEMP OF -16.1C 3RD COLDEST 850 MB TEMP IN MONTH OF NOVEMBER AT DVN... TIED WITH 2000 (11/21 00Z) AND 2005 (11/25 00Z)... WITH THE COLDEST BEING -16.8C IN 1997 (11/16 12Z). && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST THU NOV 13 2014 LOWER CLOUDS TO CONTINUE SAGGING SOUTHWARD THROUGH CWA AS SHEARING UPPER LEVEL WAVE PASSES... AND MAY SEE SOME BREAKS FOR A TIME THIS AM NORTH HALF... BUT SHOULD BE SHORT-LIVED WITH ANY DIURNAL HEATING LENDING TO MORE LOW CLOUD DEVELOPMENT. THUS... CONTINUED PT-MOCLDY SKIES ALONG WITH OCCASIONAL FLURRIES TDY. MAY SEE SOME LIGHT SNOW SHOWERS DEVELOP BY MID-LATE AM THROUGH AFTN WITH APPROACH OF SECONDARY SHORTWAVE CURRENTLY OVER NORTHERN WI... AND ALSO WITH BUFR SOUNDINGS SHOWING STEEP LOW LEVEL LAPSE RATES EXTENDING UP THROUGH THE DENDRITIC GROWTH ZONE FOR BRIEF REDUCED VSBYS WITH DUSTING OR SO OF ACCUM POSSIBLE. AS MENTIONED EARLIER... ALREADY SEEING VSBYS DROP DOWN IN RANGE OF 2-5SM OVER PORTIONS OF SOUTHERN MN EARLY THIS AM. AS FOR TEMPS... WITH CLOUDS AND MODERATE CYCLONIC FLOW WOULD EXPECT ANOTHER DAY OF LITTLE RISE ON TEMPS... WITH HIGHS RANGING FROM MID 20S TO AROUND 30F. TONIGHT... FLURRIES TO WANE EARLY FOLLOWED BY DECREASING CLOUDS WITH SUBSIDENCE BUILDING IN WAKE OF DEPARTING SHORTWAVE. ENOUGH WIND FROM NW AT 5-10 MPH SHOULD PREVENT BOTTOMING OUT ON TEMPS... BUT WITH PARTIAL CLEARING EXPECT COLDER LOWS WITH WIDESPREAD MID/UPPER TEENS. WIND CHILLS ONCE AGAIN DOWN IN THE SINGLE DIGITS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST THU NOV 13 2014 OVERVIEW...A HIGHLY AMPLIFIED UPPER LEVEL PATTERN WITH A RIDGE OVER THE E PACIFIC AND ALASKA AND A TROUGH OVER CENTRAL CANADA/U.S. WILL CONTINUE TO BE REINFORCED THROUGH MID NEXT WEEK AS A SERIES OF UPPER LEVEL DISTURBANCES DIVE SOUTHWARD FROM THE CANADIAN ARCHIPELAGO INTO THE LOWER 48. FRIDAY...AS A NOTABLE UPPER LEVEL LOW MOVES EASTWARD INTO QUEBEC...A LOW-LEVEL SFC-850 MB RIDGE AXIS WILL BUILD INTO THE FORECAST AREA WHICH WILL RESULT IN DECREASING WINDS AND DRY CONDITIONS. HOWEVER...TEMPS WILL REMAIN WELL BELOW SEASONAL AVERAGES...REACHING THE MID 20S TO LOWER 30S. THESE NUMBERS ARE CORROBORATED BY 1000-500 MB THICKNESSES NEAR 522 DAM. SREF HAS 850 MB TEMPS "WARMING" TO NEAR -11 C BY THE EVENING. SATURDAY WILL BE THE WARMEST DAY UNTIL WED OR THU OF NEXT WEEK. HIGHS WILL BE IN THE LOWER TO MIDDLE 30S AHEAD OF A POSITIVELY TILTED TROUGH DIVING SOUTHWARD INTO THE WESTERN U.S. THE WARMER TEMPS SIGNAL INCREASING MOISTURE AND A GOOD CHANCE FOR PRECIP. THE NAM/GFS/ECMWF SHOW AN AREA OF PACIFIC MOISTURE TRAVERSING THE FOUR CORNERS REGION ON FRI WHICH IS THEN ADVECTED OUT AHEAD OF THE AFOREMENTIONED TROUGH. FORCING FOR ASCENT IS TIED TO A LOW TO MID-LEVEL WAA/PRESSURE ADVECTION REGIME AND UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 300 MB JET STREAK. NEGATIVE OMEGA IS MOST PROMINENT SAT EVENING BUT IS NOT OVERLY IMPRESSIVE. THE NAM/ECMWF ARE MORE AGGRESSIVE WITH THE NORTHWARD MOISTURE TRANSPORT AND PAINT AROUND 0.15 INCHES OF QPF WHILE THE GFS IS NEAR OR SLIGHTLY BELOW 0.10 INCHES. THE NAM IS DRY THROUGH SAT AFTN BUT IS AN OUTLIER IN THIS REGARD. 850 MB TEMPS AT -10 C SUPPORT ALL SNOW...EVEN IF SFC TEMPS BRIEFLY WARM ABOVE FREEZING AT MIDDAY...EVAPORATE COOLING WILL KNOCK TEMPS TO FREEZING OR BELOW QUICKLY. SNOW RATIOS WILL BE HIGH FOR THIS TIME OF YEAR. THE DGZ DEPTH WILL BE IN THE 100-150 MB RANGE DURING THE CORE OF THE EVENT AND WILL BE DEEPEST OVER THE NORTHERN CWA. THE DGZ DEPTH WILL INCREASE TO >200 MB AFTER 06Z/SUNDAY BUT MUCH OF THE SNOW WILL HAVE FALLEN BY THIS TIME. ADDITIONALLY...SURFACE WINDS WILL BE LIGHT...SO NAM COBB SNOW RATIOS AVERAGING NEAR NEAR 16:1 ARE REASONABLE. IF MODELS STAY ON TRACK AVG SNOW AMOUNTS BETWEEN 1 TO 2 INCHES COULD BE EXPECTED ACROSS THE CWA BY LATE SAT NIGHT WITH ISOLATED 3 INCH AMOUNTS POSSIBLE. SUNDAY INTO MIDDLE OF NEXT WEEK...HARD TO BELIEVE IT IS ONLY MID NOVEMBER BUT COLDER AIR IS POISED TO ARRIVE DURING THIS TIME. MODELS IN AGREEMENT BRINGING ANOTHER SURGE OF ARCTIC AIR INTO THE MIDWEST. ANOTHER JET STREAK AND ATTENDANT VORTICITY MAX WILL ORIGINATE OVER THE ARCTIC OCEAN AND PROPAGATE STRAIGHT TO THE SOUTH THROUGH CENTRAL CANADA INTO THE CENTRAL U.S. IF IT WERE JANUARY THIS TYPE OF AIR MASS TRAJECTORY COULD RESULT IN SOME BRUTALLY COLD TEMPS. CONSENSUS HAS HIGHS IN THE LOW TO MID 20S ON MON/TUE BUT THIS MAY TREND SLIGHTLY COLDER. 850 TEMPS NEAR -20 C WOULD BE 3 STANDARD DEVIATIONS BELOW NORMAL AND WOULD BE A RECORD IN THE DVN SOUNDING CLIMATE DATA. LOWS IN THE SINGLE DIGITS FOR SEVERAL CONSECUTIVE NIGHTS ARE A REAL POSSIBILITY ALONG WITH SUB-ZERO WIND CHILLS ESPECIALLY NW OF DAVENPORT. DRY WEATHER IS FORECAST DURING THIS TIME. TEMPS TRY TO PUSH UP INTO THE LOWER TO MIDDLE BY WED AS 1000-500 MB THICKNESSES RISE TO NEAR 534 DAM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1123 AM CST THU NOV 13 2014 CONDITIONS WILL BE MAINLY MVFR THROUGH 03Z/14 WITH POCKETS OF VFR. BRIEF IFR CONDITIONS ARE LIKELY IN SNOW SHOWERS THAT AFFECT A TAF SITE AND MAY DROP VSBYS BRIEFLY DOWN TO 1SM. AFT 03Z/14 CONDITIONS WILL SLOWLY IMPROVE TO VFR AS HIGH PRESSURE BUILDS INTO THE MIDWEST. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...MCCLURE SHORT TERM...MCCLURE LONG TERM...UTTECH AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1021 AM CST THU NOV 13 2014 .UPDATE... ISSUED AT 1016 AM CST THU NOV 13 2014 A SIGNIFICANT REVISION HAS BEEN MADE TO THE FORECAST. RADAR HAS FLURRIES AND SNOW SHOWERS ACROSS THE AREA IN ADVANCE OF THE APPROACHING UPPER LEVEL DISTURBANCE. FORCING AND LIMITED DAYTIME HEATING HAS CREATED NEW CLOUDS WITH AN INCREASE IN COVERAGE OF THE FLURRIES AND SNOW SHOWERS. IF TRENDS WITH THE RAP MODEL ARE CORRECT...SOME OF THE SNOW SHOWERS SHOULD GET FAIRLY STRONG LATE THIS MORNING AND EARLY AFTERNOON WITH THE POTENTIAL FOR MINOR ACCUMULATIONS IN SOME LOCATIONS. && .SYNOPSIS... ISSUED AT 345 AM CST THU NOV 13 2014 LOWER CLOUDS HAVE ENVELOPED MUCH OF CWA FROM NORTH TO SOUTH WITH APPROACH OF SHEARING UPPER LEVEL WAVE. OCCASIONAL FLURRIES ALSO CONTINUE WITH SOME LIGHT SNOW SHOWERS PORTIONS OF SOUTHERN MN INTO NORTHERN IA BRIEFLY REDUCING VSBYS TO AROUND 2-5SM. SFC ANALYSIS SHOWS IMPRESSIVE AND ANOMALOUSLY STRONG ANTICYCLONE OF 1045+ MB OVER PORTIONS OF NORTHERN ROCKIES... WITH COUPLE OF WEAK TROUGHS OR WINDSHIFTS NOTED UPSTREAM ATTENDANT TO UPPER LEVEL DISTURBANCES BEING SHUTTLED DOWN IN CYCLONIC FLOW. ITS STILL COLD... WITH 00Z DVN RAOB 850 TEMP OF -16.1C 3RD COLDEST 850 MB TEMP IN MONTH OF NOVEMBER AT DVN... TIED WITH 2000 (11/21 00Z) AND 2005 (11/25 00Z)... WITH THE COLDEST BEING -16.8C IN 1997 (11/16 12Z). && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST THU NOV 13 2014 LOWER CLOUDS TO CONTINUE SAGGING SOUTHWARD THROUGH CWA AS SHEARING UPPER LEVEL WAVE PASSES... AND MAY SEE SOME BREAKS FOR A TIME THIS AM NORTH HALF... BUT SHOULD BE SHORT-LIVED WITH ANY DIURNAL HEATING LENDING TO MORE LOW CLOUD DEVELOPMENT. THUS... CONTINUED PT-MOCLDY SKIES ALONG WITH OCCASIONAL FLURRIES TDY. MAY SEE SOME LIGHT SNOW SHOWERS DEVELOP BY MID-LATE AM THROUGH AFTN WITH APPROACH OF SECONDARY SHORTWAVE CURRENTLY OVER NORTHERN WI... AND ALSO WITH BUFR SOUNDINGS SHOWING STEEP LOW LEVEL LAPSE RATES EXTENDING UP THROUGH THE DENDRITIC GROWTH ZONE FOR BRIEF REDUCED VSBYS WITH DUSTING OR SO OF ACCUM POSSIBLE. AS MENTIONED EARLIER... ALREADY SEEING VSBYS DROP DOWN IN RANGE OF 2-5SM OVER PORTIONS OF SOUTHERN MN EARLY THIS AM. AS FOR TEMPS... WITH CLOUDS AND MODERATE CYCLONIC FLOW WOULD EXPECT ANOTHER DAY OF LITTLE RISE ON TEMPS... WITH HIGHS RANGING FROM MID 20S TO AROUND 30F. TONIGHT... FLURRIES TO WANE EARLY FOLLOWED BY DECREASING CLOUDS WITH SUBSIDENCE BUILDING IN WAKE OF DEPARTING SHORTWAVE. ENOUGH WIND FROM NW AT 5-10 MPH SHOULD PREVENT BOTTOMING OUT ON TEMPS... BUT WITH PARTIAL CLEARING EXPECT COLDER LOWS WITH WIDESPREAD MID/UPPER TEENS. WIND CHILLS ONCE AGAIN DOWN IN THE SINGLE DIGITS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST THU NOV 13 2014 OVERVIEW...A HIGHLY AMPLIFIED UPPER LEVEL PATTERN WITH A RIDGE OVER THE E PACIFIC AND ALASKA AND A TROUGH OVER CENTRAL CANADA/U.S. WILL CONTINUE TO BE REINFORCED THROUGH MID NEXT WEEK AS A SERIES OF UPPER LEVEL DISTURBANCES DIVE SOUTHWARD FROM THE CANADIAN ARCHIPELAGO INTO THE LOWER 48. FRIDAY...AS A NOTABLE UPPER LEVEL LOW MOVES EASTWARD INTO QUEBEC...A LOW-LEVEL SFC-850 MB RIDGE AXIS WILL BUILD INTO THE FORECAST AREA WHICH WILL RESULT IN DECREASING WINDS AND DRY CONDITIONS. HOWEVER...TEMPS WILL REMAIN WELL BELOW SEASONAL AVERAGES...REACHING THE MID 20S TO LOWER 30S. THESE NUMBERS ARE CORROBORATED BY 1000-500 MB THICKNESSES NEAR 522 DAM. SREF HAS 850 MB TEMPS "WARMING" TO NEAR -11 C BY THE EVENING. SATURDAY WILL BE THE WARMEST DAY UNTIL WED OR THU OF NEXT WEEK. HIGHS WILL BE IN THE LOWER TO MIDDLE 30S AHEAD OF A POSITIVELY TILTED TROUGH DIVING SOUTHWARD INTO THE WESTERN U.S. THE WARMER TEMPS SIGNAL INCREASING MOISTURE AND A GOOD CHANCE FOR PRECIP. THE NAM/GFS/ECMWF SHOW AN AREA OF PACIFIC MOISTURE TRAVERSING THE FOUR CORNERS REGION ON FRI WHICH IS THEN ADVECTED OUT AHEAD OF THE AFOREMENTIONED TROUGH. FORCING FOR ASCENT IS TIED TO A LOW TO MID-LEVEL WAA/PRESSURE ADVECTION REGIME AND UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 300 MB JET STREAK. NEGATIVE OMEGA IS MOST PROMINENT SAT EVENING BUT IS NOT OVERLY IMPRESSIVE. THE NAM/ECMWF ARE MORE AGGRESSIVE WITH THE NORTHWARD MOISTURE TRANSPORT AND PAINT AROUND 0.15 INCHES OF QPF WHILE THE GFS IS NEAR OR SLIGHTLY BELOW 0.10 INCHES. THE NAM IS DRY THROUGH SAT AFTN BUT IS AN OUTLIER IN THIS REGARD. 850 MB TEMPS AT -10 C SUPPORT ALL SNOW...EVEN IF SFC TEMPS BRIEFLY WARM ABOVE FREEZING AT MIDDAY...EVAPORATE COOLING WILL KNOCK TEMPS TO FREEZING OR BELOW QUICKLY. SNOW RATIOS WILL BE HIGH FOR THIS TIME OF YEAR. THE DGZ DEPTH WILL BE IN THE 100-150 MB RANGE DURING THE CORE OF THE EVENT AND WILL BE DEEPEST OVER THE NORTHERN CWA. THE DGZ DEPTH WILL INCREASE TO >200 MB AFTER 06Z/SUNDAY BUT MUCH OF THE SNOW WILL HAVE FALLEN BY THIS TIME. ADDITIONALLY...SURFACE WINDS WILL BE LIGHT...SO NAM COBB SNOW RATIOS AVERAGING NEAR NEAR 16:1 ARE REASONABLE. IF MODELS STAY ON TRACK AVG SNOW AMOUNTS BETWEEN 1 TO 2 INCHES COULD BE EXPECTED ACROSS THE CWA BY LATE SAT NIGHT WITH ISOLATED 3 INCH AMOUNTS POSSIBLE. SUNDAY INTO MIDDLE OF NEXT WEEK...HARD TO BELIEVE IT IS ONLY MID NOVEMBER BUT COLDER AIR IS POISED TO ARRIVE DURING THIS TIME. MODELS IN AGREEMENT BRINGING ANOTHER SURGE OF ARCTIC AIR INTO THE MIDWEST. ANOTHER JET STREAK AND ATTENDANT VORTICITY MAX WILL ORIGINATE OVER THE ARCTIC OCEAN AND PROPAGATE STRAIGHT TO THE SOUTH THROUGH CENTRAL CANADA INTO THE CENTRAL U.S. IF IT WERE JANUARY THIS TYPE OF AIRMASS TRAJECTORY COULD RESULT IN SOME BRUTALLY COLD TEMPS. CONSENSUS HAS HIGHS IN THE LOW TO MID 20S ON MON/TUE BUT THIS MAY TREND SLIGHTLY COLDER. 850 TEMPS NEAR -20 C WOULD BE 3 STANDARD DEVIATIONS BELOW NORMAL AND WOULD BE A RECORD IN THE DVN SOUNDING CLIMATE DATA. LOWS IN THE SINGLE DIGITS FOR SEVERAL CONSECUTIVE NIGHTS ARE A REAL POSSIBILITY ALONG WITH SUB-ZERO WIND CHILLS ESPECIALLY NW OF DAVENPORT. DRY WEATHER IS FORECAST DURING THIS TIME. TEMPS TRY TO PUSH UP INTO THE LOWER TO MIDDLE BY WED AS 1000-500 MB THICKNESSES RISE TO NEAR 534 DAM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1016 AM CST THU NOV 13 2014 SNOW SHOWERS ARE INCREASING IN COVERAGE ACROSS EASTERN IOWA AND NORTHERN ILLINOIS. IF CURRENT TRENDS FROM THE RAP MODEL ARE CORRECT...SOME OF THE SNOW SHOWERS MAY BE QUITE STRONG AND PRODUCE A PERIOD OF IFR CONDITIONS. THIS HAS ALREADY OCCURRED AT KDBQ WHICH LENDS SOME CREDENCE TO WHAT THE RAP MODEL IS SUGGESTING. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...MCCLURE SHORT TERM...MCCLURE LONG TERM...UTTECH AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
559 AM CST THU NOV 13 2014 .SYNOPSIS... ISSUED AT 345 AM CST THU NOV 13 2014 LOWER CLOUDS HAVE ENVELOPED MUCH OF CWA FROM NORTH TO SOUTH WITH APPROACH OF SHEARING UPPER LEVEL WAVE. OCCASIONAL FLURRIES ALSO CONTINUE WITH SOME LIGHT SNOW SHOWERS PORTIONS OF SOUTHERN MN INTO NORTHERN IA BRIEFLY REDUCING VSBYS TO AROUND 2-5SM. SFC ANALYSIS SHOWS IMPRESSIVE AND ANOMALOUSLY STRONG ANTICYCLONE OF 1045+ MB OVER PORTIONS OF NORTHERN ROCKIES... WITH COUPLE OF WEAK TROUGHS OR WINDSHIFTS NOTED UPSTREAM ATTENDANT TO UPPER LEVEL DISTURBANCES BEING SHUTTLED DOWN IN CYCLONIC FLOW. ITS STILL COLD... WITH 00Z DVN RAOB 850 TEMP OF -16.1C 3RD COLDEST 850 MB TEMP IN MONTH OF NOVEMBER AT DVN... TIED WITH 2000 (11/21 00Z) AND 2005 (11/25 00Z)... WITH THE COLDEST BEING -16.8C IN 1997 (11/16 12Z). && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CST THU NOV 13 2014 LOWER CLOUDS TO CONTINUE SAGGING SOUTHWARD THROUGH CWA AS SHEARING UPPER LEVEL WAVE PASSES... AND MAY SEE SOME BREAKS FOR A TIME THIS AM NORTH HALF... BUT SHOULD BE SHORT-LIVED WITH ANY DIURNAL HEATING LENDING TO MORE LOW CLOUD DEVELOPMENT. THUS... CONTINUED PT-MOCLDY SKIES ALONG WITH OCCASIONAL FLURRIES TDY. MAY SEE SOME LIGHT SNOW SHOWERS DEVELOP BY MID-LATE AM THROUGH AFTN WITH APPROACH OF SECONDARY SHORTWAVE CURRENTLY OVER NORTHERN WI... AND ALSO WITH BUFR SOUNDINGS SHOWING STEEP LOW LEVEL LAPSE RATES EXTENDING UP THROUGH THE DENDRITIC GROWTH ZONE FOR BRIEF REDUCED VSBYS WITH DUSTING OR SO OF ACCUM POSSIBLE. AS MENTIONED EARLIER... ALREADY SEEING VSBYS DROP DOWN IN RANGE OF 2-5SM OVER PORTIONS OF SOUTHERN MN EARLY THIS AM. AS FOR TEMPS... WITH CLOUDS AND MODERATE CYCLONIC FLOW WOULD EXPECT ANOTHER DAY OF LITTLE RISE ON TEMPS... WITH HIGHS RANGING FROM MID 20S TO AROUND 30F. TONIGHT... FLURRIES TO WANE EARLY FOLLOWED BY DECREASING CLOUDS WITH SUBSIDENCE BUILDING IN WAKE OF DEPARTING SHORTWAVE. ENOUGH WIND FROM NW AT 5-10 MPH SHOULD PREVENT BOTTOMING OUT ON TEMPS... BUT WITH PARTIAL CLEARING EXPECT COLDER LOWS WITH WIDESPREAD MID/UPPER TEENS. WIND CHILLS ONCE AGAIN DOWN IN THE SINGLE DIGITS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST THU NOV 13 2014 OVERVIEW...A HIGHLY AMPLIFIED UPPER LEVEL PATTERN WITH A RIDGE OVER THE E PACIFIC AND ALASKA AND A TROUGH OVER CENTRAL CANADA/U.S. WILL CONTINUE TO BE REINFORCED THROUGH MID NEXT WEEK AS A SERIES OF UPPER LEVEL DISTURBANCES DIVE SOUTHWARD FROM THE CANADIAN ARCHIPELAGO INTO THE LOWER 48. FRIDAY...AS A NOTABLE UPPER LEVEL LOW MOVES EASTWARD INTO QUEBEC...A LOW-LEVEL SFC-850 MB RIDGE AXIS WILL BUILD INTO THE FORECAST AREA WHICH WILL RESULT IN DECREASING WINDS AND DRY CONDITIONS. HOWEVER...TEMPS WILL REMAIN WELL BELOW SEASONAL AVERAGES...REACHING THE MID 20S TO LOWER 30S. THESE NUMBERS ARE CORROBORATED BY 1000-500 MB THICKNESSES NEAR 522 DAM. SREF HAS 850 MB TEMPS "WARMING" TO NEAR -11 C BY THE EVENING. SATURDAY WILL BE THE WARMEST DAY UNTIL WED OR THU OF NEXT WEEK. HIGHS WILL BE IN THE LOWER TO MIDDLE 30S AHEAD OF A POSITIVELY TILTED TROUGH DIVING SOUTHWARD INTO THE WESTERN U.S. THE WARMER TEMPS SIGNAL INCREASING MOISTURE AND A GOOD CHANCE FOR PRECIP. THE NAM/GFS/ECMWF SHOW AN AREA OF PACIFIC MOISTURE TRAVERSING THE FOUR CORNERS REGION ON FRI WHICH IS THEN ADVECTED OUT AHEAD OF THE AFOREMENTIONED TROUGH. FORCING FOR ASCENT IS TIED TO A LOW TO MID-LEVEL WAA/PRESSURE ADVECTION REGIME AND UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 300 MB JET STREAK. NEGATIVE OMEGA IS MOST PROMINENT SAT EVENING BUT IS NOT OVERLY IMPRESSIVE. THE NAM/ECMWF ARE MORE AGGRESSIVE WITH THE NORTHWARD MOISTURE TRANSPORT AND PAINT AROUND 0.15 INCHES OF QPF WHILE THE GFS IS NEAR OR SLIGHTLY BELOW 0.10 INCHES. THE NAM IS DRY THROUGH SAT AFTN BUT IS AN OUTLIER IN THIS REGARD. 850 MB TEMPS AT -10 C SUPPORT ALL SNOW...EVEN IF SFC TEMPS BRIEFLY WARM ABOVE FREEZING AT MIDDAY...EVAPORATE COOLING WILL KNOCK TEMPS TO FREEZING OR BELOW QUICKLY. SNOW RATIOS WILL BE HIGH FOR THIS TIME OF YEAR. THE DGZ DEPTH WILL BE IN THE 100-150 MB RANGE DURING THE CORE OF THE EVENT AND WILL BE DEEPEST OVER THE NORTHERN CWA. THE DGZ DEPTH WILL INCREASE TO >200 MB AFTER 06Z/SUNDAY BUT MUCH OF THE SNOW WILL HAVE FALLEN BY THIS TIME. ADDITIONALLY...SURFACE WINDS WILL BE LIGHT...SO NAM COBB SNOW RATIOS AVERAGING NEAR NEAR 16:1 ARE REASONABLE. IF MODELS STAY ON TRACK AVG SNOW AMOUNTS BETWEEN 1 TO 2 INCHES COULD BE EXPECTED ACROSS THE CWA BY LATE SAT NIGHT WITH ISOLATED 3 INCH AMOUNTS POSSIBLE. SUNDAY INTO MIDDLE OF NEXT WEEK...HARD TO BELIEVE IT IS ONLY MID NOVEMBER BUT COLDER AIR IS POISED TO ARRIVE DURING THIS TIME. MODELS IN AGREEMENT BRINGING ANOTHER SURGE OF ARCTIC AIR INTO THE MIDWEST. ANOTHER JET STREAK AND ATTENDANT VORTICITY MAX WILL ORIGINATE OVER THE ARCTIC OCEAN AND PROPAGATE STRAIGHT TO THE SOUTH THROUGH CENTRAL CANADA INTO THE CENTRAL U.S. IF IT WERE JANUARY THIS TYPE OF AIRMASS TRAJECTORY COULD RESULT IN SOME BRUTALLY COLD TEMPS. CONSENSUS HAS HIGHS IN THE LOW TO MID 20S ON MON/TUE BUT THIS MAY TREND SLIGHTLY COLDER. 850 TEMPS NEAR -20 C WOULD BE 3 STANDARD DEVIATIONS BELOW NORMAL AND WOULD BE A RECORD IN THE DVN SOUNDING CLIMATE DATA. LOWS IN THE SINGLE DIGITS FOR SEVERAL CONSECUTIVE NIGHTS ARE A REAL POSSIBILITY ALONG WITH SUB-ZERO WIND CHILLS ESPECIALLY NW OF DAVENPORT. DRY WEATHER IS FORECAST DURING THIS TIME. TEMPS TRY TO PUSH UP INTO THE LOWER TO MIDDLE BY WED AS 1000-500 MB THICKNESSES RISE TO NEAR 534 DAM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 549 AM CST THU NOV 13 2014 STRATUS WITH MVFR TO LOWER VFR CIGS AND OCCASIONAL FLURRIES AND NORTHWEST WINDS AROUND 10-15 KTS EXPECTED TODAY. WITH AN APPROACHING UPPER LEVEL DISTURBANCE THERE MAY ALSO BE SOME SNOW SHOWERS AROUND FROM MID AM THROUGH AFTN... WHICH COULD DROP VSBYS IN RANGE OF AROUND 2-5SM FOR BRIEF PERIODS OF TIME RESULTING IN A DUSTING OF ACCUM. NOT CONFIDENT ON IMPACT AT TERMINAL ATTIM THUS LEFT OUT MENTION. RAP MODEL MOST AGGRESSIVE WITH DEPICTING LOW MVFR STRATUS HANGING ON MUCH OF TONIGHT... AND FOR NOW SIDED TOWARD MORE OPTIMISTIC CONSENSUS AS ANTICIPATE SUBSIDENCE IN WAKE OF DEPARTING DISTURBANCE MAY AID IN PARTIAL CLEARING WITH ANY CIGS LIFTING TO VFR. NORTHWEST WINDS EXPECTED IN GENERAL RANGE OF 5-9 KTS TONIGHT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...MCCLURE SHORT TERM...MCCLURE LONG TERM...UTTECH AVIATION...05
AREA FORECAST DISCUSSION
NWS GOODLAND KS
400 PM MST THU NOV 13 2014 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 126 PM MST THU NOV 13 2014 DECENT REBOUND IN AREA TEMPERATURES OFF OF THE MORNING LOWS...AS THE FORECAST AREA CURRENTLY SITS IN THE UPPER TEENS THROUGH THE MID 20S...UNDER MSUNNY/SUNNY SKIES. RIDGE AXIS CONTINUES TO PUSH SLOWLY EASTWARD FURTHER ON INTO THE CENTRAL PLAINS...ALLOWING FOR WEAK RETURN/SOUTHERLY FLOW TO WORK INTO WESTERN PORTIONS OF THE FORECAST AREA. THE CLOUD COVER ASSOCIATED WITH THE SYSTEM MOVING THRU THE ROCKIES WILL CONTINUE TO PUSH NORTH AND EAST ACROSS THE TRI STATE REGION OVERNIGHT...WITH THE ENTIRE AREA UNDER SOUTHERLY WIND REGIME. INITIALLY LOOKING FOR MID/HIGH CLOUDS TO SHIFT OVER AREA...BUT AFTER MIDNIGHT TONIGHT LOW LEVEL CLOUDS THAT HAVE BEEN SITTING OFF TO OUR SOUTH AND EAST WILL WORK NORTHWARD. FOCUS FOR ANY FLURRIES OR WEAK --SW WILL OCCUR MAINLY OVER EASTERN COLORADO WHERE TEMP/PRESSURE CONFLUENCE IS OCCURRING BETWEEN APPROACHING SYSTEM AND STRONG RIDGE TO THE EAST OF THE CWA. THIS IS CURRENTLY OVER CENTRAL COLORADO AND WILL SHIFT EAST OVERNIGHT. NO MAJOR ACCUMULATION IS EXPECTED WITH AFFECTED AREA SEEING A TRACE TO ONLY A FEW TENTHS OF AN INCH. FOR TEMPS/WIND CHILL CONCERNS OVERNIGHT...NOT PLANNING ON ANY PRODUCT ISSUANCE AT THIS TIME AS WITH SOUTHERLY FLOW REMAINING INTACT OVERNIGHT AND INCREASING CLOUD COVER EXPECTED. TEMPS ARE EXPECTED TO FALL INTO/CLOSE TO THE SINGLE NUMBERS UNTIL THICKER LOW LEVEL CLOUDS ARRIVE THEN SHOULD HOLD STEADY OR SLOWLY INCREASE FROM THERE. OVERALL LOWS FOR TONIGHT WILL RANGE IN THE SINGLE NUMBERS ABOVE ZERO...WARMEST IN EASTERN ZONES. GOING INTO FRIDAY...MUCH OF THE CWA WILL REMAIN UNDER PARTLY SUNNY CONDITIONS...WITH RIDGE TO THE EAST AND AREA UNDER SOUTHERLY FLOW AROUND 10-20 MPH. EXPECTED CLOUD COVER WILL HAMPER DAYTIME HIGHS DESPITE WINDS...SO HAVE UNDERCUT MODEL GUIDANCE GIVING THE AREA A RANGE IN THE MID TO UPPER 20S FOR HIGH TEMPERATURES. POSSIBILITY FOR SOME BRIEF MORNING FLURRIES OR SNOW SHOWERS ACROSS NW ZONES OTHERWISE LOOKING FOR NO OTHER WEATHER TO AFFECT THE AREA DURING THE DAY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 136 PM MST THU NOV 13 2014 AN UPPER LEVEL SHORT WAVE TROUGH EMBEDDED IN THE JET IN PLACE ACROSS THE SOUTHERN UNITED STATES TRAVERSES THE SOUTHWEST UNITED STATES ON FRIDAY AND MOVES EAST OF THE ROCKIES AND ACROSS THE SOUTHERN AND CENTRAL HIGH PLAINS EARLY SATURDAY. THIS WILL SPREAD AN AREA OF LIGHT SNOW ACROSS MAINLY THE SOUTHERN AND EASTERN SECTIONS OF THE FORECAST AREA FRIDAY NIGHT AND SATURDAY MORNING. THE UPPER SHORT WAVE TROUGH EXITS TO THE EAST OUT OF THE REGION WITH THE NEXT STRONGER UPPER TROUGH DIVING SOUTH THROUGH THE WESTERN UNITED STATES. THIS STRONGER TROUGH MOVES THROUGH THE CENTRAL HIGH PLAINS REGION SATURDAY NIGHT AND EARLY SUNDAY WITH AN AREA OF SUBSIDENCE MOVING ACROSS THE FORECAST AREA BY SUNDAY AFTERNOON. THIS WILL SPREAD ANOTHER AREA OF LIGHT SNOW SOUTHWARD ACROSS MAINLY THE WESTERN PORTIONS OF THE FORECAST AREA LATE SATURDAY THROUGH SATURDAY NIGHT THAT WILL END QUICKLY EARLY SUNDAY. TOTAL SNOWFALL AMOUNTS FROM THE TWO PERIOD OF LIGHT SNOW WILL VARY FROM LESS THAN AN INCH ACROSS SOUTHWEST NEBRASKA TO NEARLY 3 INCHES OVER CENTRAL KANSAS. EASTERN COLORADO SHOULD SEE BETWEEN 1 AND 2 INCHES OF SNOW. EXPECT TEMPERATURES TO COOL SATURDAY AND SATURDAY NIGHT AS THE SURGE OF COLD AIR MOVES IN BEHIND A COLD FRONT. SHOULD SEE TEMPERATURES RISING AGAIN ON SUNDAY AND THROUGH NEXT WEEK AS COLD AIR STARTS MOVING OUT OF THE REGION. THE HIGH AMPLITUDE RIDGE OVER THE WESTERN UNITED STATES IS EXPECTED TO FLATTEN AND MOVE EASTWARD OVER THE ROCKIES AND THE CENTRAL HIGH PLAINS REGION BY MID-WEEK. RESULTING CONDITIONS ARE EXPECTED TO BE DRY NEXT WEEK THROUGH THE MIDDLE OF THE WEEK WITH DAYTIME HIGHS RETURNING TO THE 40S BY WEDNESDAY AND THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 400 PM MST THU NOV 13 2014 BATCH OF 850-500 MOISTURE FORECAST TO REACH THE KGLD TERMINAL FROM THE WEST AROUND 03Z...EXITING IN THE 06Z-07Z TIMEFRAME. FOR KMCK IT ARRIVES AROUND 07Z AND EXITS TO THE NORTHEAST AROUND 10Z. LEFT FRONT QUAD OF UPPER JET HEADS FROM THE FOUR CORNERS AREA AT TAF ISSUANCE TO THE OKLAHOMA PANHANDLE BY 12Z FRIDAY. THERE SHOULD BE SOME SUPPORT FROM THE JET AND A BIT OF MID LEVEL FORCING TO PRODUCE SOME FLURRIES AS THE DISTURBANCE MOVES THROUGH. FOR NOW WILL LEAVE FLURRIES OUT AS THEY ARENT EXPECTED TO CREATE AN AVIATION HAZARD OR BRING TERMINALS TO MVFR CATEGORIES. FRIDAY...FOR KGLD WE SHOULD BE IN BETWEEN SYSTEMS THUS A MOSTLY SUNNY SKY. FOR KMCK THERE IS ENOUGH LINGERING LOW LEVEL MOISTURE TO PRODUCE A BKN DECK OF CLOUDS AROUND/JUST ABOVE MVFR RANGE. AM CONCERNED ABOUT MVFR CLOUDS CURRENTLY ALONG THE FRONT RANGE AND ALONG/SOUTH OF THE PALMER DIVIDE PER OBS AND RUC 75+ PERCENT RH REACHING THE KGLD TERMINAL IN THE 03Z-09Z TIMEFRAME. HAVE DEBATED WHETHER OR NOT INCLUDE MVFR CIGS AND FOR NOW HAVE KEPT THEM OUT OF THE TAF BUT WILL WATCH CLOSELY. OTHERWISE...SOUTH WINDS AROUND 10KTS AT KGLD AT TAF ISSUANCE CONTINUE THROUGH 14Z THEN INCREASE AND GUST IN THE 20-25KT RANGE IN THE 17Z-22Z TIMEFRAME. FOR KMCK LGT/VRB WINDS AT TAF ISSUANCE BECOME SOUTHEASTERLY AROUND 07KTS AT 10Z THEN VEER TO THE SOUTH AND GUST 15-20KTS FROM 17Z-22Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JN LONG TERM...LOCKHART AVIATION...99
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1135 AM CST Thu Nov 13 2014 .UPDATE... Issued at 1135 CST THU NOV 13 2014 Updated for aviation forecast discussion. .SHORT TERM...(Today through Saturday) Issued at 350 AM CST THU NOV 13 2014 A near term challenge is forecasting the coverage of clouds, which have been a broken mix of low, mid, and high variety overnight. It looks like the RAP model may have the best handle on the overall pattern of cloudiness, if not necessarily the coverage (which appeared a bit lacking in the model). The diminishing of most cloudiness should be underway across the wrn two thirds of the PAH forecast area by midday, with a possible resurgence in the I-64 corridor during the afternoon. It appears that the clearing pattern is generally associated with a 700 mb trof axis which is forecast to move ewd through the cyclonic pattern aloft. After today, opaque cloud cover should be minimal. An arctic air mass will continue to filter into the region through Fri night, before easing off to the east on Sat. The mid/upper pattern will take on brief ridging ahead of the next system. Low level flow should have enough time to turn to the south by Sat afternoon, giving a limited boost to temps. Measurable pcpn is possible in the afternoon, first rainfall, then perhaps some snowfall in the nwrn half of our region toward evening as the lower trop cools. The area with the best chance of measuring more than a tenth of an inch of snow will be the higher elevations of the Ozark Foothills. Temps much below average will continue in the short term period. .LONG TERM...(Saturday night through Wednesday) Issued at 350 AM CST THU NOV 13 2014 Low to medium forecast confidence in the long term with models still not in good agreement. Overrunning precipitation due to isentropic upglide should be underway at the beginning of the long term period. Thermal profiles still indicating all precipitation to be snow, but models still quite different on QPF amounts. Models do however indicate the best chances for snow Saturday night should be over the northwest half of the CWA. The latest GFS run still the colder of the extended models. A cold front is still expected to blast across the CWA on Sunday. For Sunday morning, thermal profiles would suggest a rain/snow/sleet mix over the southeast third of our CWA with snow elsewhere. For Sunday afternoon models are indicating the lower levels warming up a bit, so expect snow over the northwest third, a rain/snow/sleet mix over the middle third, with all rain over the southeast third. Sunday evening, in the wake of the frontal passage, the combination of the approach of a short wave, an inverted trough over the deep south, and plenty of moisture will induce a deformation zone and produce yet another overrunning precipitation scenario but with more impressive QPF amounts than Saturday night. As the cooler post-frontal air overspreads the region Sunday evening, expect a snow/sleet mix over the southeast third of the CWA, with all snow elsewhere. After midnight Sunday night precipitation should change over to all snow. Snow may linger over the far southeast portions of our CWA Monday morning, but little to no additional snow accumulation is expected. Total snow accumulation from Saturday night through Sunday night should max out somewhere in the 1.5-2.0 inch range area-wide, with the majority falling Sunday night. Beyond that, high pressure at the surface and flow aloft becoming more northwest should produce dry conditions through the remainder of the long term period along with below normal temperatures. && .AVIATION... Issued at 1135 AM CST THU NOV 13 2014 As an arctic air mass continues to filter into the region, substantial cloud cover will probably linger for most of the daylight hours and low level moisture is abundant. Latest satellite shows a decent looking strato-cu deck heading southeast into the region. Not sure how long this low vfr deck will stick around past 00Z, but that will have to be watched in addition to any lowering of ceilings after dark. If any clouds do linger into the evening/overnight, they should clear by morning as the main trough to our north pushes east. North to nw sustained winds around 10-12 knots with occasional higher gusts will prevail during the day before decreasing overnight. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
957 AM CST Thu Nov 13 2014 .UPDATE... Issued at 957 AM CST THU NOV 13 2014 KPAH/KEVV radar along with a few spotter reports have revealed a few snow flurries/light snow showers occurring with this band of clouds moving through the area this morning. According to radar, it appears most of the echoes are over S. IL, SW IN and parts of W. KY. Looking upstream, there are additional reports of flurries in association with more clouds heading this way. So, will add in some scattered flurries to the forecast grids for several hours based on these trends. No accumulation expected. .SHORT TERM...(Today through Saturday) Issued at 350 AM CST THU NOV 13 2014 A near term challenge is forecasting the coverage of clouds, which have been a broken mix of low, mid, and high variety overnight. It looks like the RAP model may have the best handle on the overall pattern of cloudiness, if not necessarily the coverage (which appeared a bit lacking in the model). The diminishing of most cloudiness should be underway across the wrn two thirds of the PAH forecast area by midday, with a possible resurgence in the I-64 corridor during the afternoon. It appears that the clearing pattern is generally associated with a 700 mb trof axis which is forecast to move ewd through the cyclonic pattern aloft. After today, opaque cloud cover should be minimal. An arctic air mass will continue to filter into the region through Fri night, before easing off to the east on Sat. The mid/upper pattern will take on brief ridging ahead of the next system. Low level flow should have enough time to turn to the south by Sat afternoon, giving a limited boost to temps. Measurable pcpn is possible in the afternoon, first rainfall, then perhaps some snowfall in the nwrn half of our region toward evening as the lower trop cools. The area with the best chance of measuring more than a tenth of an inch of snow will be the higher elevations of the Ozark Foothills. Temps much below average will continue in the short term period. .LONG TERM...(Saturday night through Wednesday) Issued at 350 AM CST THU NOV 13 2014 Low to medium forecast confidence in the long term with models still not in good agreement. Overrunning precipitation due to isentropic upglide should be underway at the beginning of the long term period. Thermal profiles still indicating all precipitation to be snow, but models still quite different on QPF amounts. Models do however indicate the best chances for snow Saturday night should be over the northwest half of the CWA. The latest GFS run still the colder of the extended models. A cold front is still expected to blast across the CWA on Sunday. For Sunday morning, thermal profiles would suggest a rain/snow/sleet mix over the southeast third of our CWA with snow elsewhere. For Sunday afternoon models are indicating the lower levels warming up a bit, so expect snow over the northwest third, a rain/snow/sleet mix over the middle third, with all rain over the southeast third. Sunday evening, in the wake of the frontal passage, the combination of the approach of a short wave, an inverted trough over the deep south, and plenty of moisture will induce a deformation zone and produce yet another overrunning precipitation scenario but with more impressive QPF amounts than Saturday night. As the cooler post-frontal air overspreads the region Sunday evening, expect a snow/sleet mix over the southeast third of the CWA, with all snow elsewhere. After midnight Sunday night precipitation should change over to all snow. Snow may linger over the far southeast portions of our CWA Monday morning, but little to no additional snow accumulation is expected. Total snow accumulation from Saturday night through Sunday night should max out somewhere in the 1.5-2.0 inch range area-wide, with the majority falling Sunday night. Beyond that, high pressure at the surface and flow aloft becoming more northwest should produce dry conditions through the remainder of the long term period along with below normal temperatures. && .AVIATION... Issued at 619 AM CST THU NOV 13 2014 As an arctic air mass continues to filter into the region, VFR cigs are forecast to lift this morning, but substantial cloud cover will probably linger for most of the daylight hours in the ern third of the region. North to nw sustained winds around 10-12 knots will prevail during the day before decreasing overnight. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...CW SHORT TERM...DB LONG TERM...JP AVIATION...DB
AREA FORECAST DISCUSSION
NWS PADUCAH KY
619 AM CST Thu Nov 13 2014 .UPDATE... Issued at 619 AM CST THU NOV 13 2014 Updated aviation discussion only. .SHORT TERM...(Today through Saturday) Issued at 350 AM CST THU NOV 13 2014 A near term challenge is forecasting the coverage of clouds, which have been a broken mix of low, mid, and high variety overnight. It looks like the RAP model may have the best handle on the overall pattern of cloudiness, if not necessarily the coverage (which appeared a bit lacking in the model). The diminishing of most cloudiness should be underway across the wrn two thirds of the PAH forecast area by midday, with a possible resurgence in the I-64 corridor during the afternoon. It appears that the clearing pattern is generally associated with a 700 mb trof axis which is forecast to move ewd through the cyclonic pattern aloft. After today, opaque cloud cover should be minimal. An arctic air mass will continue to filter into the region through Fri night, before easing off to the east on Sat. The mid/upper pattern will take on brief ridging ahead of the next system. Low level flow should have enough time to turn to the south by Sat afternoon, giving a limited boost to temps. Measurable pcpn is possible in the afternoon, first rainfall, then perhaps some snowfall in the nwrn half of our region toward evening as the lower trop cools. The area with the best chance of measuring more than a tenth of an inch of snow will be the higher elevations of the Ozark Foothills. Temps much below average will continue in the short term period. .LONG TERM...(Saturday night through Wednesday) Issued at 350 AM CST THU NOV 13 2014 Low to medium forecast confidence in the long term with models still not in good agreement. Overrunning precipitation due to isentropic upglide should be underway at the beginning of the long term period. Thermal profiles still indicating all precipitation to be snow, but models still quite different on QPF amounts. Models do however indicate the best chances for snow Saturday night should be over the northwest half of the CWA. The latest GFS run still the colder of the extended models. A cold front is still expected to blast across the CWA on Sunday. For Sunday morning, thermal profiles would suggest a rain/snow/sleet mix over the southeast third of our CWA with snow elsewhere. For Sunday afternoon models are indicating the lower levels warming up a bit, so expect snow over the northwest third, a rain/snow/sleet mix over the middle third, with all rain over the southeast third. Sunday evening, in the wake of the frontal passage, the combination of the approach of a short wave, an inverted trough over the deep south, and plenty of moisture will induce a deformation zone and produce yet another overrunning precipitation scenario but with more impressive QPF amounts than Saturday night. As the cooler post-frontal air overspreads the region Sunday evening, expect a snow/sleet mix over the southeast third of the CWA, with all snow elsewhere. After midnight Sunday night precipitation should change over to all snow. Snow may linger over the far southeast portions of our CWA Monday morning, but little to no additional snow accumulation is expected. Total snow accumulation from Saturday night through Sunday night should max out somewhere in the 1.5-2.0 inch range area-wide, with the majority falling Sunday night. Beyond that, high pressure at the surface and flow aloft becoming more northwest should produce dry conditions through the remainder of the long term period along with below normal temperatures. && .AVIATION... Issued at 619 AM CST THU NOV 13 2014 As an arctic air mass continues to filter into the region, VFR cigs are forecast to lift this morning, but substantial cloud cover will probably linger for most of the daylight hours in the ern third of the region. North to nw sustained winds around 10-12 knots will prevail during the day before decreasing overnight. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DB LONG TERM...JP AVIATION...DB
AREA FORECAST DISCUSSION
NWS PADUCAH KY
350 AM CST Thu Nov 13 2014 .SHORT TERM...(Today through Saturday) Issued at 350 AM CST THU NOV 13 2014 A near term challenge is forecasting the coverage of clouds, which have been a broken mix of low, mid, and high variety overnight. It looks like the RAP model may have the best handle on the overall pattern of cloudiness, if not necessarily the coverage (which appeared a bit lacking in the model). The diminishing of most cloudiness should be underway across the wrn two thirds of the PAH forecast area by midday, with a possible resurgence in the I-64 corridor during the afternoon. It appears that the clearing pattern is generally associated with a 700 mb trof axis which is forecast to move ewd through the cyclonic pattern aloft. After today, opaque cloud cover should be minimal. An arctic air mass will continue to filter into the region through Fri night, before easing off to the east on Sat. The mid/upper pattern will take on brief ridging ahead of the next system. Low level flow should have enough time to turn to the south by Sat afternoon, giving a limited boost to temps. Measurable pcpn is possible in the afternoon, first rainfall, then perhaps some snowfall in the nwrn half of our region toward evening as the lower trop cools. The area with the best chance of measuring more than a tenth of an inch of snow will be the higher elevations of the Ozark Foothills. Temps much below average will continue in the short term period. .LONG TERM...(Saturday night through Wednesday) Issued at 350 AM CST THU NOV 13 2014 Low to medium forecast confidence in the long term with models still not in good agreement. Overrunning precipitation due to isentropic upglide should be underway at the beginning of the long term period. Thermal profiles still indicating all precipitation to be snow, but models still quite different on QPF amounts. Models do however indicate the best chances for snow Saturday night should be over the northwest half of the CWA. The latest GFS run still the colder of the extended models. A cold front is still expected to blast across the CWA on Sunday. For Sunday morning, thermal profiles would suggest a rain/snow/sleet mix over the southeast third of our CWA with snow elsewhere. For Sunday afternoon models are indicating the lower levels warming up a bit, so expect snow over the northwest third, a rain/snow/sleet mix over the middle third, with all rain over the southeast third. Sunday evening, in the wake of the frontal passage, the combination of the approach of a short wave, an inverted trough over the deep south, and plenty of moisture will induce a deformation zone and produce yet another overrunning precipitation scenario but with more impressive QPF amounts than Saturday night. As the cooler post-frontal air overspreads the region Sunday evening, expect a snow/sleet mix over the southeast third of the CWA, with all snow elsewhere. After midnight Sunday night precipitation should change over to all snow. Snow may linger over the far southeast portions of our CWA Monday morning, but little to no additional snow accumulation is expected. Total snow accumulation from Saturday night through Sunday night should max out somewhere in the 1.5-2.0 inch range area-wide, with the majority falling Sunday night. Beyond that, high pressure at the surface and flow aloft becoming more northwest should produce dry conditions through the remainder of the long term period along with below normal temperatures. && .AVIATION... Issued at 1147 PM CST THU NOV 13 2014 Apparently the cloud depth was narrow enough at KEVV/KOWB to erode during the evening hours. With the 06z Thursday TAF issuance, the trend toward broken VFR ceilings was continued. Unrestricted ceilings should dominate for the latter 12 hours of the forecast period. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DB LONG TERM...JP AVIATION...DB
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1148 PM CST Wed Nov 12 2014 .UPDATE... Issued at 840 PM CST WED NOV 12 2014 Just updated most notably for cloud trends through the night. The west edge of the low clouds has slowed to a crawl from near Evansville Indiana to near Murray Kentucky, but widespread mid- level clouds have developed over the remainder of the area. Guidance still pushes the low clouds east of the area by midnight, but keeps the mid clouds over the area through much of the night, before clearing in the morning. It appears that there will be a lull in the north winds late this evening and into the overnight hours, but the latest model data shows a tightening pressure gradient toward morning, so winds will likely pick up significantly by daybreak. The combination of clouds and winds should keep temperatures from dropping much tonight. Lows were hardly changed across the region with this update. Noticed single digit dewpoints as close as central Missouri as of 02Z. With the continued northwest winds, our dewpoint forecast may not be low even across at least the northwest half of the area during the day Thursday. && .SHORT TERM...(Tonight through Friday night) Issued at 121 PM CST WED NOV 12 2014 Clouds continued to cover the CWFA early this afternoon, keeping temperatures from rising much as well. Breaks continue to head SE from Missouri and west IL. Should see a gradual decrease with time. RAP was a decent guide in handling the general trend. At the surface, strong high pressure with unseasonably cold air will continue to move southeast, overspreading the area. It should finally be centered over our area by 12z Saturday. Meanwhile, a double barrel low over the northern Plains and Great Lakes will phase, with one low heading up through Quebec, while energy from the western end swings across the Upper Midwest and Great Lakes tonight through Thursday. Expect mainly mid and upper level clouds tonight through early Thursday, followed by decreasing clouds. NW flow will persist as energy dives south into the Rockies from west Canada Friday through Friday night. Dry weather is forecast with just a few clouds from Thursday afternoon through Friday night. As far as temperatures, followed a blend of the slightly colder MOS and standard model output. MOS appears to have finally caught on to the degree of cold air. Prior output from a few days ago, MOS had its typical mild climo influence bias, while the standard raw model output was better identifying how cold it would likely be. No real model preference in the short term tonight and beyond. A GFS/NAM blend was used. .LONG TERM...(Saturday through Wednesday) Issued at 121 PM CST WED NOV 12 2014 Main focus continues to be on weekend precip (even wintry) chances, and the continued cold. Both the GFS and ECMWF ops runs continue to suffer run to run inconsistencies, especially with respect to timing in response to the evolution of the mid tropospheric flow pattern over the CONUS east of the Rockies. The GFS is trending toward, and ECMWF back towards separate energy that may pinch off the main trof over the Southern Rockies, eventually heading east over the weekend. The models continue to advertise a lead weak s/wv that will move from the southern Rockies to Mississippi Valley region Saturday into Saturday night. May see rather light wintry mix into SEMO by afternoon. Will continue with light rain/light snow mention here. Saturday night, as the wave moves ENE, the models continue to hint at a band of light precip (parameters suggest light snow), for parts of the area. Not much QPF, so still not expecting much. But any minor coating of light snow around here...well. The models are not showing much now for Sunday, thus will keep PoPs on the low side. As some slightly warmer boundary layer air advects into the SE 1/2 of the CWFA (still favor the slightly colder GFS), will use a mix (including light rain) mention, with just light snow NW 1/2. As the aforementioned mid level wave moves east Sunday and phases with the parent broad mid level trof by Sunday night, models ramp up moisture a bit over the SE 1/2 of the area. This is slower, so PoPs will need to linger Sunday night, vs. early depictions of ending things by Sunday evening. This is where the back and forth (changing forecast) has been most prominent. Again types, light wintry mix possible SE 1/2, just a small chance of light snow NW 1/2. The GFS remains quicker departing chances, while the ECMWF lingers the chance now through early Monday. Given the adjustments and changes that continue to go on within the models, will keep PoPs in check and only in the chance category for now. Otherwise continued cold through early next week. Dry weather returns for most of Monday on through Wednesday. && .AVIATION... Issued at 1147 PM CST WED NOV 12 2014 Apparently the cloud depth was narrow enough at KEVV/KOWB to erode during the evening hours. With the 06z Thursday TAF issuance, the trend toward broken VFR ceilings was continued. Unrestricted ceilings should dominate for the latter 12 hours of the forecast period. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS AVIATION...Smith
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1237 PM EST THU NOV 13 2014 .SYNOPSIS... LOW PRESSURE DEVELOPS ALONG A STALLED FRONT OVER THE CAROLINAS THIS AFTERNOON...AND STRENGTHENS OFF THE COAST TONIGHT. HIGH PRESSURE BUILDS INTO THE REGION FRIDAY THROUGH SUNDAY MORNING...USHERING IN MUCH BELOW NORMAL TEMPERATURES. THE NEXT CHANCE FOR RAIN COMES SUNDAY NIGHT THROUGH MONDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... QUITE THE DIFFERENCE IN CONDS FM 24 HRS AGO. MUCH COOLER AMS HAS SETTLED OVR THE RGN ON NNW WNDS. PLENTY OF CLDNS COVERS THE FA ATTM...AND THAT WILL CONT THROUGH THE REST OF THE DAY. PATCHY VERY LGT RA TRACKS ACRS PORTIONS OF THE AREA (MNLY INLAND) SO FAR THIS MRNG. WILL HANG ONTO SLGT CHC POPS FOR THOSE AREAS INTO THE AFTN HRS. OTRW...AWAITING RA TO DEVELOP/ARRIVE LT THIS AFTN/EARLY EVE AS VERY WK WAVE OF LO PRES TRACKS NE INVOF CSTL PLAIN IN ERN NC. LTL EVIDENCE OF PCPN SO FAR TO THE SSW...HWVR THAT SHOULD CHANGE DURG THE AFTN HRS (THOUGH 15Z/13 RUC KEEPS BULK OF ANY PCPN LARGELY TO AREAS OVR NE NC THROUGH 00Z/14). WILL HAVE POPS INCRSG TO 30-50% AFT 21Z/13 (HIGHEST S). TEMPS RMNG IN THE M/U40S N AND CNTRL LOCATIONS...FALLING INTO THE 40S/L50S FAR SE VA/CSTL NE NC. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... BEST CHANCE FOR PRECIP IN MOST AREAS LOOKS TO OCCUR IN THE EVENING HRS...AS SECONDARY SURGE OF COLD AIR ARRIVES WITH THE COLD FRONT AND THE SFC LOW INTENSIFIES OFFSHORE. PRECIP LINGERS INTO THE EARLY AM HRS FRI ALONG THE COAST. WILL BE ALL RAIN INTIALLY THIS EVE...WITH COLDER AIR PUSHING IN FROM THE NW BETWEEN 03-06Z. MAIN AREA OF FORCING/UVM DEPARTING AFTER MDNGT AS COOLING BEGINS. TIMING WOULD BE CRUCIAL FOR ANY PSBL MIXED PTYPE (RA/SN) AS BNDRY LYR IS THE LAST TO SUFFICIENTLY COOL. WILL CONTINUE TO CONFINE MENTION OF SN TO AREAS MNLY N OF A LINE FM FVX TO RIC TO SBY (EARLIEST/LT THU EVE W...AFT MDNGT E). NO IMPACT (FM ANY FROZEN PCPN) IS XPCD. LO TEMPS THU NGT ARND 30F FAR NW TO THE U30S/ARND 40F RIGHT AT THE CST. PCPN WINDING DOWN QUICKLY BY EARLY FRI MRNG W/ CLDS SLO TO EXIT TO THE E. GUSTY NNW WNDS USHER IN COLD/DRY AIR ON FRI...SETTING UP A VERY COLD NGT FRI NGT W/ SKC AND DIMINISHING WNDS. HIGHS FRI IN THE MID-UPPER 40S. PTNTL EXISTS FOR A FREEZE FM KPHF TO KORF/KNTU (LAST RMNG AREAS TO BE IN AKQ FROST/FREEZE PROGRAM)...WILL DEPEND ON WIND SPEED AND DIRECTION...BUT MOST OF THESE AREAS EXCEPT THE IMMEDIATE COAST APPEAR TO HAVE A GOOD CHANCE FOR MINS AT OR BELOW 32 F. WELL INALND A HARD FREEZE APPEARS LIKELY WITH LOWS IN THE LOWER TO MID 20S. SAT WILL BE DRY/CHILLY W/ SFC HI PRES SETTLING OVR THE RGN FM THE WNW. LIGHETER WINDS AND MOSTLY SUNNY WITH HIGHS ONLY IN THE MID 40S MOST AREAS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AN ACTIVE PATTERN WITH GENERALLY BELOW NORMAL TEMPERATURES IS INDICATED. AS A PIECE OF THE ARCTIC HIGH PRESSURE FROM THE PLAINS STATES MOVES EAST AND OFF THE COAST SUNDAY...A SECONDARY FRONT AND GENERAL AREA OF LOW PRESSURE AFFECTS THE EASTERN PART OF THE NATION LATE SUNDAY THROUGH EARLY TUESDAY. SUNDAY IS NOW FORECAST TO BE DRY. BOTH THE 12Z RUNS OF THE GFS AND EURO INDICATE LOW PRESSURE MOVING OUT THE SOUTHWEST WITH THE PERIOD OF PCPN LATER THAN PREVIOUS FORECASTS. HAVE LIKELY POPS ACROSS THE CWA FOR BOTH SUNDAY NIGHT AND MONDAY. THE LOW PULLS OFF TO THE NORTHEAST MONDAY NIGHT WITH PCPN ENDING FROM THE WEST. DRY WEATHER IS INDICATED FOR TUESDAY THROUGH WEDNESDAY. LOW LEVEL THICKNESSES ARGUE AGAINST SNOW AT THIS TIME WITH THE AFOREMENTIONED SYSTEM. SOME LIGHT FREEZING RAIN OR SLEET OVER THE PIEDMONT COULD OCCUR AT THE INITIATION OF THE EVENT SUNDAY NIGHT WITH LOW DEW POINTS IN PLACE BUT CONFIDENCE IS LOW AND LEFT THIS OUT OF THE FORECAST. HIGH TEMPERATURES SUNDAY AND MONDAY RANGE FROM THE UPR 40S NW TO MID 50S SE EXCEPT WARMING TO THE UPR 50S TO LWR 60S FAR SE VA AND NE NC MONDAY. HIGHS RANGE THROUGH THE 40S TUESDAY AND WEDNESDAY. LOWS SUNDAY MORNING WILL BE A BIT WARMER THAN THOSE OF SATURDAY MORNING...RANGING FROM THE MID 20S INLAND TO NEAR FREEZING AT THE COAST. LOWS IN THE 30S INLAND TO LWR 40S AT THE COAST MONDAY MORNING COOL TO THE 30S TUESDAY MORNING AND THE 20S WEDNESDAY MORNING. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... OVC CIGS (2000-3000 FT) ARE ALREADY FOUND ACROSS THE AREA THIS AFTERNOON. EXPECT THESE CIGS TO CONTINUE INTO TONIGHT. LOW PRESSURE MOVES NE OFF THE COAST TONIGHT AND SHOULD PROVIDE THE FOCUS FOR SOME -RA OR -DZ AT ALL TAF SITES BETWEEN 22Z-06Z...BEFORE PCPN ENDS FROM WEST TO EAST OVERNIGHT. CONDITIONS EXPECTED TO GENERALLY REMAIN MVFR BUT IFR CERTAINLY POSSIBLE. A FEW SNOW FLAKES ARE POSSIBLE AT RIC/SBY LATE TNGT/EARLY FRI MORNING AS PCPN ENDS. STRONG NORTHERLY WINDS THEN USHER EVEN DRIER AIR INTO THE REGION BEHIND THE EXITING LOW FOR FRIDAY. OUTLOOK...DRY WX AND VFR CONDITIONS EXPECTED EVERYWHERE FROM FRI INTO EARLY SUN. GOOD CHC FOR MORE RAIN SUN NGT INTO MON NGT WITH POSSIBLE IFR CONDITIONS. && .MARINE... NNE WINDS WILL WEAKEN A BIT DURING TODAY...BUT STRONG NNW WINDS (15 TO 25 KT WITH GUSTS TO ARND 30 KT) ARE EXPECTED LATER THIS EVENG INTO AT LEAST FRI EVENG...DUE TO LO PRES TRACKING NNE OFF THE MID ATLC CST TWD THE CANADIAN MARITIMES AND COLD HI PRES BLDNG IN FM THE W. WINDS/CONDITIONS WILL THEN CALM DOWN SAT THRU SUN MORNG...AS HI PRES BLDS OVR THE AREA AND JUST OFFSHR. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR ANZ635>638. SMALL CRAFT ADVISORY UNTIL 10 PM EST FRIDAY FOR ANZ630>634-650- 652-654-656-658. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...ALB/LKB LONG TERM...LKB/LSA AVIATION...JDM MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1031 AM EST THU NOV 13 2014 .SYNOPSIS... LOW PRESSURE DEVELOPS ALONG A STALLED FRONT OVER THE CAROLINAS THIS AFTERNOON...AND STRENGTHENS OFF THE COAST TONIGHT. HIGH PRESSURE BUILDS INTO THE REGION FRIDAY THROUGH SUNDAY MORNING...USHERING IN MUCH BELOW NORMAL TEMPERATURES. THE NEXT CHANCE FOR RAIN COMES SUNDAY NIGHT THROUGH MONDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... QUITE THE DIFFERENCE IN CONDS FM 24 HRS AGO. MUCH COOLER AMS HAS SETTLED OVR THE RGN ON NNW WNDS. PLENTY OF CLDNS COVERS THE FA ATTM...AND THAT WILL CONT THROUGH THE REST OF THE DAY. PATCHY VERY LGT RA TRACKS ACRS PORTIONS OF THE AREA (MNLY INLAND) SO FAR THIS MRNG. WILL HANG ONTO SLGT CHC POPS FOR THOSE AREAS INTO THE AFTN HRS. OTRW...AWAITING RA TO DEVELOP/ARRIVE LT THIS AFTN/EARLY EVE AS VERY WK WAVE OF LO PRES TRACKS NE INVOF CSTL PLAIN IN ERN NC. LTL EVIDENCE OF PCPN SO FAR TO THE SSW...HWVR THAT SHOULD CHANGE DURG THE AFTN HRS (THOUGH 15Z/13 RUC KEEPS BULK OF ANY PCPN LARGELY TO AREAS OVR NE NC THROUGH 00Z/14). WILL HAVE POPS INCRSG TO 30-50% AFT 21Z/13 (HIGHEST S). TEMPS RMNG IN THE M/U40S N AND CNTRL LOCATIONS...FALLING INTO THE 40S/L50S FAR SE VA/CSTL NE NC. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... BEST CHANCE FOR PRECIP IN MOST AREAS LOOKS TO OCCUR IN THE EVENING HRS...AS SECONDARY SURGE OF COLD AIR ARRIVES WITH THE COLD FRONT AND THE SFC LOW INTENSIFIES OFFSHORE. PRECIP LINGERS INTO THE EARLY AM HRS FRI ALONG THE COAST. WILL BE ALL RAIN INTIALLY THIS EVE...WITH COLDER AIR PUSHING IN FROM THE NW BETWEEN 03-06Z. MAIN AREA OF FORCING/UVM DEPARTING AFTER MDNGT AS COOLING BEGINS. TIMING WOULD BE CRUCIAL FOR ANY PSBL MIXED PTYPE (RA/SN) AS BNDRY LYR IS THE LAST TO SUFFICIENTLY COOL. WILL CONTINUE TO CONFINE MENTION OF SN TO AREAS MNLY N OF A LINE FM FVX TO RIC TO SBY (EARLIEST/LT THU EVE W...AFT MDNGT E). NO IMPACT (FM ANY FROZEN PCPN) IS XPCD. LO TEMPS THU NGT ARND 30F FAR NW TO THE U30S/ARND 40F RIGHT AT THE CST. PCPN WINDING DOWN QUICKLY BY EARLY FRI MRNG W/ CLDS SLO TO EXIT TO THE E. GUSTY NNW WNDS USHER IN COLD/DRY AIR ON FRI...SETTING UP A VERY COLD NGT FRI NGT W/ SKC AND DIMINISHING WNDS. HIGHS FRI IN THE MID-UPPER 40S. PTNTL EXISTS FOR A FREEZE FM KPHF TO KORF/KNTU (LAST RMNG AREAS TO BE IN AKQ FROST/FREEZE PROGRAM)...WILL DEPEND ON WIND SPEED AND DIRECTION...BUT MOST OF THESE AREAS EXCEPT THE IMMEDIATE COAST APPEAR TO HAVE A GOOD CHANCE FOR MINS AT OR BELOW 32 F. WELL INALND A HARD FREEZE APPEARS LIKELY WITH LOWS IN THE LOWER TO MID 20S. SAT WILL BE DRY/CHILLY W/ SFC HI PRES SETTLING OVR THE RGN FM THE WNW. LIGHETER WINDS AND MOSTLY SUNNY WITH HIGHS ONLY IN THE MID 40S MOST AREAS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AN ACTIVE PATTERN WITH GENERALLY BELOW NORMAL TEMPERATURES IS INDICATED. AS A PIECE OF THE ARCTIC HIGH PRESSURE FROM THE PLAINS STATES MOVES EAST AND OFF THE COAST SUNDAY...A SECONDARY FRONT AND GENERAL AREA OF LOW PRESSURE AFFECTS THE EASTERN PART OF THE NATION LATE SUNDAY THROUGH EARLY TUESDAY. SUNDAY IS NOW FORECAST TO BE DRY. BOTH THE 12Z RUNS OF THE GFS AND EURO INDICATE LOW PRESSURE MOVING OUT THE SOUTHWEST WITH THE PERIOD OF PCPN LATER THAN PREVIOUS FORECASTS. HAVE LIKELY POPS ACROSS THE CWA FOR BOTH SUNDAY NIGHT AND MONDAY. THE LOW PULLS OFF TO THE NORTHEAST MONDAY NIGHT WITH PCPN ENDING FROM THE WEST. DRY WEATHER IS INDICATED FOR TUESDAY THROUGH WEDNESDAY. LOW LEVEL THICKNESSES ARGUE AGAINST SNOW AT THIS TIME WITH THE AFOREMENTIONED SYSTEM. SOME LIGHT FREEZING RAIN OR SLEET OVER THE PIEDMONT COULD OCCUR AT THE INITIATION OF THE EVENT SUNDAY NIGHT WITH LOW DEW POINTS IN PLACE BUT CONFIDENCE IS LOW AND LEFT THIS OUT OF THE FORECAST. HIGH TEMPERATURES SUNDAY AND MONDAY RANGE FROM THE UPR 40S NW TO MID 50S SE EXCEPT WARMING TO THE UPR 50S TO LWR 60S FAR SE VA AND NE NC MONDAY. HIGHS RANGE THROUGH THE 40S TUESDAY AND WEDNESDAY. LOWS SUNDAY MORNING WILL BE A BIT WARMER THAN THOSE OF SATURDAY MORNING...RANGING FROM THE MID 20S INLAND TO NEAR FREEZING AT THE COAST. LOWS IN THE 30S INLAND TO LWR 40S AT THE COAST MONDAY MORNING COOL TO THE 30S TUESDAY MORNING AND THE 20S WEDNESDAY MORNING. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... SCT TO BKN SC/AC (4000-9000 FT) WILL SPREAD INTO AND ACRS THE REGION DURING TODAY...AS WEAK LO PRES DEVELOPS ALNG THE NC CST. LWR SC (MVFR CIGS) LIKELY BY EARLY THIS EVENG...AND WILL LAST INTO THE OVRNGT AT ALL TAF SITES WITH -RA POSSIBLE EVERYWHERE...AS THE LO MOVES NE OFF THE MID ATLC AND SRN NEW ENGLAND CST WHILE INTENSIFYING A BIT. A FEW FLURRIES POSSIBLE AT RIC/SBY LATE TNGT/EARLY FRI MORNG BEFORE PCPN ENDS. STRONG NORTHERLY WINDS THEN USHER EVEN DRIER AIR INTO THE REGION BEHIND THE EXITING LO FOR LATE TNGT INTO FRI AFTN. OUTLOOK...DRY WX AND VFR CONDITIONS EXPECTED EVERYWHERE FM MID MORNG FRI INTO EARLY SUN. GOOD CHC FOR MORE RAIN SUN NGT INTO MON NGT WITH POSSIBLE IFR CONDITIONS. && .MARINE... NNE WINDS WILL WEAKEN A BIT DURING TODAY...BUT STRONG NNW WINDS (15 TO 25 KT WITH GUSTS TO ARND 30 KT) ARE EXPECTED LATER THIS EVENG INTO AT LEAST FRI EVENG...DUE TO LO PRES TRACKING NNE OFF THE MID ATLC CST TWD THE CANADIAN MARITIMES AND COLD HI PRES BLDNG IN FM THE W. WINDS/CONDITIONS WILL THEN CALM DOWN SAT THRU SUN MORNG...AS HI PRES BLDS OVR THE AREA AND JUST OFFSHR. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR ANZ635>638. SMALL CRAFT ADVISORY UNTIL 10 PM EST FRIDAY FOR ANZ630>634-650- 652-654-656-658. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...ALB/LKB LONG TERM...LKB/LSA AVIATION...TMG MARINE...TMG
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1250 PM EST THU NOV 13 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 316 AM EST THU NOV 13 2014 SNOW SHOWERS...LOCALLY HEAVY ARE EXPECTED TODAY SOUTH OF INTERSTATE 96 AND WEST OF US-131. WHILE THE SNOW SHOWERS WILL DIMINISH SOME LATE THIS AFTERNOON THEY WILL CONTINUE INTO FRIDAY AFTERNOON RESULTING IN LOCAL ACCUMULATIONS AS HIGH AS 9 INCHES IN PARTS OF ALLEGAN AND OTTAWA COUNTIES. SNOW SHOWERS WILL ALSO RESULT IN 4 TO 6 INCHES OF SNOW WEST OF US-131 AND NORTH OF MUSKEGON INTO FRIDAY AFTERNOON. ELSEWHERE LIGHT SNOW SHOWERS WILL CONTINUE INTO FRIDAY WITH AN INCH OR LESS OF ACCUMULATION. THE UNSEASONABLY COLD TEMPERATURES...NEAR TO BELOW FREEZING WILL CONTINUE THROUGH MOST OF NEXT WEEK. THE SNOW SHOWERS SHOULD COME TO AN END SATURDAY ONLY TO START BACK UP ON SUNDAY AND CONTINUE INTO WEDNESDAY. A SECOND ARCTIC FRONT WILL BRING EVEN COLDER AIR IN THE TUESDAY TO WEDNESDAY TIME FRAME. && .UPDATE... ISSUED AT 824 AM EST THU NOV 13 2014 BASED ON REPORTS OF UP TO 3.5 INCHES IN MUSKEGON COUNTY AND THAT MKG HAS MODERATE TO HEAVY SNOW WITH A SNOW INCREASE ONE AT 8 AM... WE RECENTLY HAVE HAD REPORTS OF SCHOOL BUSES HAVING PROBLEMS MAKING UP HILLS AND SOME EMERGENCY VEHICLES HAVING PROBLEMS STOPPING DUE TO THE SNOW AND ICE. SO...IT MAKES SENSE INCLUDE MUSKEGON IN THE ADVISORY. ALSO I EXPECT THE SNOW TO CONTINUE THERE HEAVY AT TIMES FOR A FEW MORE HOURS YET. THEN THE SNOW WILL REDEVELOP AGAIN THIS EVENING. I COULD SEE 5 TO 7 INCHES BY MIDDAY TOMORROW IN PARTS OF SOUTHERN AND CENTRAL MUSKEGON COUNTY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE WINTER WEATHER ADVISORY IS OUR PRIMARY FOCUS THIS MORNING. IT LOOKS VERY GOOD FOR THE HEAVIER SNOWFALL OVER OTTAWA AND ALLEGAN COUNTIES THIS MORNING BUT IT LOOKS LESS GOOD FOR THE HEAVIER SNOWFALLS OVER OUR NW CWA EVEN SO... I CONTINUED THE ADVISORY THERE SINCE THAT IS A TYPICAL PLACE FOR HEAVIER SNOW WITH A WEST TO NORTHWEST WIND FLOW. BASED ON THE LATEST DATA FROM OUR HIGH RESOLUTIONS MODELS... GETTING HEAVIER SNOWFALL AMOUNTS OVER OTTAWA AND ALLEGAN COUNTY THIS MORNING INTO EARLY THIS AFTERNOON STILL LOOKS GOOD. THE HEAVY SNOW BANDS ARE FORECAST TO OCCUR FROM MID MORNING INTO EARLY THIS AFTERNOON OVER ALLEGAN AND OTTAWA COUNTIES BY THE RAP...NAM AND HRRR MODELS. THE HRRR HAS CONSISTENTLY SHOWN 4 TO 7 INCHES BETWEEN 6 AM AND AND 2 PM THIS AFTERNOON IN TWO BANDS OVER OTTAWA AND ALLEGAN COUNTIES. THIS IS SIMILAR TO THE OUTPUT OF THE NAMDNG55. SINCE THE LATEST RADAR IS CURRENTLY SHOWING A SIGNIFICANT INCREASE IN INTENSITY AND BIV HAS SHOW VISIBILITIES DOWN TO NEAR 1 MILE ALREADY... I HAVE TO BELIEVE THE LOCALLY HEAVIER SNOW BANDS ARE MORE THAN POSSIBLE. WHAT ALSO GOES ALONG WITH THIS IS THE LIFT IF THE DGZ IS IMPRESSIVE ON ALL THREE MODELS OVER THOSE TWO COUNTIES. THE INVERSION HEIGHTS LIFT TO NEAR 11000 FT BY MID MORNING TOO. ALL OF THAT HELPS THE CAUSE OF HEAVIER SNOW BANDS IN OUR ADVISORY AREA. WHAT IS FORCING ALL OF THIS IS A SIGNIFICANT SHORTWAVE THAT MOVES THROUGH THE CWA DURING THE MIDDAY HOURS. IT IS THIS SHORTWAVE THE FINALLY PUSHES THE POLAR JET CORE SOUTH OF MICHIGAN. THAT WAS FORECAST TO HAPPEN SOONER BY EARLIER RUNS OF THE MODELS BUT THIS SHORTWAVE WILL DO THE TRICK AND PUT SOUTHWEST MICHIGAN IN THE DEEP COLD AIR INTO FRIDAY EVENING. ONCE THE SHORTWAVE IS THROUGH THE INTENSITY OF THE SNOW SHOWERS WILL DECREASE BUT WE WILL STILL HAVE LIFT IN THE DGZ WITH NEAR SATURATION DUE OVER ICE THROUGH FRIDAY AFTERNOON SO THE SNOW SHOWERS WILL CONTINUE INTO FRIDAY AFTERNOON FOR SURE. FRIDAY NIGHT INTO SATURDAY THE SURFACE HIGH MOVES IN AND BY MID MORNING SATURDAY THE AIR BECOMES SO DRY THAT GETTING LAKE EFFECT CLOUDS WILL HE HARD TO DO...EVEN WITH THE 20C DIFFERENCE BETWEEN THE LAKE TEMPERATURE AND 850 MB. SO WE SHOULD FINALLY SEE A DRY PERIOD. INLAND AREAS TODAY THROUGH FRIDAY WILL SEE OCCASIONAL SNOW SHOWER WITH THE HELP OF DAY TIME MIXING BRINGING THE SHOWER INLAND. ALSO THE WEST NORTHWEST WINDS WILL HELP THAT CAUSE TOO. TEMPERATURES SHOULD LARGELY STAY NEAR TO BELOW FREEZING ALL THREE AFTERNOONS AND FALL INTO THE 20S AT NIGHT. CLOUDS DUE TO THE WEST TO NORTHWEST WINDS WILL KEEP IT FROM GETTING MUCH COLDER THAN THAT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE COLD SNOWY PATTERN WILL CONTINUE THROUGH THE LONG TERM. HOWEVER BY LATE WEDNESDAY...MODELS ARE HINTING THAT THE CORE OF THE COLD AIR WILL START TO LIFT OUT. THE MAIN FOCUS IS ON MONDAY AND TUESDAY. THAT/S THE TIME FRAME WHEN A DEEP TROUGH WILL MOVE OVER THE GREAT LAKES AND PRODUCE ANOTHER BLAST OF ARCTIC AIR. BOTH THE GFS AND ECMWF ARE SIMILAR IN TIMING AND STRENGTH OF THE UPPER TROUGH. H8 TEMPS FALL TO -16C BY TUESDAY AFTERNOON. WNW BOUNDARY LAYER WINDS SHOULD RESULT IN LAKE EFFECT SNOW MONDAY THROUGH TUESDAY. THE DGZ DOES FALL TO AROUND 4K FT...BUT IS PRETTY TYPICAL FOR THIS TYPE OF COLD AIR. WE/RE LIKELY GOING TO SEE SEVERAL INCHES OF SNOWFALL DURING THIS TIME FRAME AND WE BOOSTED POPS TO ACCOUNT FOR IT. PRIOR TO THE BLAST OF ARCTIC AIR ARRIVING SUNDAY NIGHT...WE/LL SEE SOME WARM AIR ADVECTION SNOW SATURDAY NIGHT THAT WILL CONTINUE INTO SUNDAY. ACCUMS IN THE 1-3 INCH RANGE LOOK REASONABLE SATURDAY NIGHT BASED ON MIXING RATIOS AND THE STRENGTH OF THE ISENTROPIC LIFT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1243 PM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PERSIST THROUGH MUCH OF THE PERIOD. AIRPORTS CLOSER TO LAKE MICHIGAN WILL SEE GREATER IMPACTS. TEMPORARILY IFR IS LIKELY THROUGH THE AFTERNOON FOR KGRR...KMKG...KAZO AND KBTL. FURTHER INLAND...WHILE IFR WAS NOT INCLUDED IN THE FORECAST...THE RISK IS NOT ZERO. SNOW SHOWERS WILL REMAIN NUMEROUS THROUGH TONIGHT WITH IFR MOST LIKELY FOR KMKG...KGRR AND KAZO. KBTL WILL BE CLOSE TO THE HEAVY SNOW BANDS...BUT I WAS NOT CONFIDENT ENOUGH TO GO WITH THE GREATER IMPACTS THERE. ICING WILL BE A CONCERN AS WELL FOR ALL SITES...ESPECIALLY TONIGHT AND FRIDAY. && .MARINE... ISSUED AT 316 AM EST THU NOV 13 2014 I CONTINUED THE SMALL CRAFT ADVISORY AS IS THROUGH FRIDAY AFTERNOON. IT WOULD SEEM HIGH PRESSURE BUILDING INTO THE AREA DURING FRIDAY AFTERNOON SHOULD DECREASE THE PRESSURE GRADIENT AND ALLOW WINDS AND WAVES TO FINALLY SUBSIDE. UNTIL THEN NORTHWEST WINDS OF 15 TO 25 KNOTS SHOULD PREVAIL. && .HYDROLOGY... ISSUED AT 310 PM EST WED NOV 12 2014 NO HYDROLOGY CONCERNS FOR THE NEXT WEEK WITH ANY PCPN OVER THE NEXT WEEK IN THE FORM OF SNOW AND UNSEASONABLY COLD TEMPS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST FRIDAY FOR MIZ037-038-043- 050-056-064-071-072. LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LMZ844>849. && $$ UPDATE...WDM SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...93 AVIATION...MJS HYDROLOGY...LAURENS MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
826 AM EST THU NOV 13 2014 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 316 AM EST THU NOV 13 2014 SNOW SHOWERS...LOCALLY HEAVY ARE EXPECTED TODAY SOUTH OF INTERSTATE 96 AND WEST OF US-131. WHILE THE SNOW SHOWERS WILL DIMINISH SOME LATE THIS AFTERNOON THEY WILL CONTINUE INTO FRIDAY AFTERNOON RESULTING IN LOCAL ACCUMULATIONS AS HIGH AS 9 INCHES IN PARTS OF ALLEGAN AND OTTAWA COUNTIES. SNOW SHOWERS WILL ALSO RESULT IN 4 TO 6 INCHES OF SNOW WEST OF US-131 AND NORTH OF MUSKEGON INTO FRIDAY AFTERNOON. ELSEWHERE LIGHT SNOW SHOWERS WILL CONTINUE INTO FRIDAY WITH AN INCH OR LESS OF ACCUMULATION. THE UNSEASONABLY COLD TEMPERATURES...NEAR TO BELOW FREEZING WILL CONTINUE THROUGH MOST OF NEXT WEEK. THE SNOW SHOWERS SHOULD COME TO AN END SATURDAY ONLY TO START BACK UP ON SUNDAY AND CONTINUE INTO WEDNESDAY. A SECOND ARCTIC FRONT WILL BRING EVEN COLDER AIR IN THE TUESDAY TO WEDNESDAY TIME FRAME. && .UPDATE... ISSUED AT 824 AM EST THU NOV 13 2014 BASED ON REPORTS OF UP TO 3.5 INCHES IN MUSKEGON COUNTY AND THAT MKG HAS MODERATE TO HEAVY SNOW WITH A SNOW INCREASE ONE AT 8 AM... WE RECENTLY HAVE HAD REPORTS OF SCHOOL BUSES HAVING PROBLEMS MAKING UP HILLS AND SOME EMERGENCY VEHICELS HAVING PROBLEMS STOPPING DUE TO THE SNOW AND ICE. SO...IT MAKES SENSE INCLUDE MUSKEGON IN THE ADVISORY. ALSO I EXPECT THE SNOW TO CONTINUE THERE HEAVY AT TIMES FOR A FEW MORE HOURS YET. THEN THE SNOW WILL REDEVELOP AGAIN THIS EVENING. I COULD SEE 5 TO 7 INCHES BY MIDDAY TOMORROW IN PARTS OF SOUTHERN AND CENTRAL MUSKEGON COUNTY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE WINTER WEATHER ADVISORY IS OUR PRIMARY FOCUS THIS MORNING. IT LOOKS VERY GOOD FOR THE HEAVIER SNOWFALL OVER OTTAWA AND ALLEGAN COUNTIES THIS MORNING BUT IT LOOKS LESS GOOD FOR THE HEAVIER SNOWFALLS OVER OUR NW CWA EVEN SO... I CONTINUED THE ADVISORY THERE SINCE THAT IS A TYPICAL PLACE FOR HEAVIER SNOW WITH A WEST TO NORTHWEST WIND FLOW. BASED ON THE LATEST DATA FROM OUR HIGH RESOLUTIONS MODELS... GETTING HEAVIER SNOWFALL AMOUNTS OVER OTTAWA AND ALLEGAN COUNTY THIS MORNING INTO EARLY THIS AFTERNOON STILL LOOKS GOOD. THE HEAVY SNOW BANDS ARE FORECAST TO OCCUR FROM MID MORNING INTO EARLY THIS AFTERNOON OVER ALLEGAN AND OTTAWA COUNTIES BY THE RAP...NAM AND HRRR MODELS. THE HRRR HAS CONSISTENTLY SHOWN 4 TO 7 INCHES BETWEEN 6 AM AND AND 2 PM THIS AFTERNOON IN TWO BANDS OVER OTTAWA AND ALLEGAN COUNTIES. THIS IS SIMILAR TO THE OUTPUT OF THE NAMDNG55. SINCE THE LATEST RADAR IS CURRENTLY SHOWING A SIGNIFICANT INCREASE IN INTENSITY AND BIV HAS SHOW VISIBILITIES DOWN TO NEAR 1 MILE ALREADY... I HAVE TO BELIEVE THE LOCALLY HEAVIER SNOW BANDS ARE MORE THAN POSSIBLE. WHAT ALSO GOES ALONG WITH THIS IS THE LIFT IF THE DGZ IS IMPRESSIVE ON ALL THREE MODELS OVER THOSE TWO COUNTIES. THE INVERSION HEIGHTS LIFT TO NEAR 11000 FT BY MID MORNING TOO. ALL OF THAT HELPS THE CAUSE OF HEAVIER SNOW BANDS IN OUR ADVISORY AREA. WHAT IS FORCING ALL OF THIS IS A SIGNIFICANT SHORTWAVE THAT MOVES THROUGH THE CWA DURING THE MIDDAY HOURS. IT IS THIS SHORTWAVE THE FINALLY PUSHES THE POLAR JET CORE SOUTH OF MICHIGAN. THAT WAS FORECAST TO HAPPEN SOONER BY EARLIER RUNS OF THE MODELS BUT THIS SHORTWAVE WILL DO THE TRICK AND PUT SOUTHWEST MICHIGAN IN THE DEEP COLD AIR INTO FRIDAY EVENING. ONCE THE SHORTWAVE IS THROUGH THE INTENSITY OF THE SNOW SHOWERS WILL DECREASE BUT WE WILL STILL HAVE LIFT IN THE DGZ WITH NEAR SATURATION DUE OVER ICE THROUGH FRIDAY AFTERNOON SO THE SNOW SHOWERS WILL CONTINUE INTO FRIDAY AFTERNOON FOR SURE. FRIDAY NIGHT INTO SATURDAY THE SURFACE HIGH MOVES IN AND BY MID MORNING SATURDAY THE AIR BECOMES SO DRY THAT GETTING LAKE EFFECT CLOUDS WILL HE HARD TO DO...EVEN WITH THE 20C DIFFERENCE BETWEEN THE LAKE TEMPERATURE AND 850 MB. SO WE SHOULD FINALLY SEE A DRY PERIOD. INLAND AREAS TODAY THROUGH FRIDAY WILL SEE OCCASIONAL SNOW SHOWER WITH THE HELP OF DAY TIME MIXING BRINGING THE SHOWER INLAND. ALSO THE WEST NORTHWEST WINDS WILL HELP THAT CAUSE TOO. TEMPERATURES SHOULD LARGELY STAY NEAR TO BELOW FREEZING ALL THREE AFTERNOONS AND FALL INTO THE 20S AT NIGHT. CLOUDS DUE TO THE WEST TO NORTHWEST WINDS WILL KEEP IT FROM GETTING MUCH COLDER THAN THAT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE COLD SNOWY PATTERN WILL CONTINUE THROUGH THE LONG TERM. HOWEVER BY LATE WEDNESDAY...MODELS ARE HINTING THAT THE CORE OF THE COLD AIR WILL START TO LIFT OUT. THE MAIN FOCUS IS ON MONDAY AND TUESDAY. THAT/S THE TIME FRAME WHEN A DEEP TROUGH WILL MOVE OVER THE GREAT LAKES AND PRODUCE ANOTHER BLAST OF ARCTIC AIR. BOTH THE GFS AND ECMWF ARE SIMILAR IN TIMING AND STRENGTH OF THE UPPER TROUGH. H8 TEMPS FALL TO -16C BY TUESDAY AFTERNOON. WNW BOUNDARY LAYER WINDS SHOULD RESULT IN LAKE EFFECT SNOW MONDAY THROUGH TUESDAY. THE DGZ DOES FALL TO AROUND 4K FT...BUT IS PRETTY TYPICAL FOR THIS TYPE OF COLD AIR. WE/RE LIKELY GOING TO SEE SEVERAL INCHES OF SNOWFALL DURING THIS TIME FRAME AND WE BOOSTED POPS TO ACCOUNT FOR IT. PRIOR TO THE BLAST OF ARCTIC AIR ARRIVING SUNDAY NIGHT...WE/LL SEE SOME WARM AIR ADVECTION SNOW SATURDAY NIGHT THAT WILL CONTINUE INTO SUNDAY. ACCUMS IN THE 1-3 INCH RANGE LOOK REASONABLE SATURDAY NIGHT BASED ON MIXING RATIOS AND THE STRENGTH OF THE ISENTROPIC LIFT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 622 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PREVAIL THROUGH TOMORROW BUT THE MORE INTENSE SNOW SHOWERS WILL BE THIS MORNING...NEAR THE LAKE SHORE (MKG)...POSSIBLY REACHING GRR AND AZO/BTL. LAN AND JXN SHOULD MOSTLY BE MVFR WITH CIGS AND OCNL SNOW SHOWERS. THE TAFS ARE WRITTEN TO SHOW MOSTLY VFR CONDITIONS AFTER 18Z BUT I DO EXPECT THE SNOW BANDS TO MOVE BACK INTO AZO /BTL BY EARLY EVENING SO I TOOK THEM TO IFR AFTER 02Z. THOSE SNOW BANDS MAY ALSO IMPACT MKG AND GRR BUT I DID NOT SHOW THAT IN THE TAF FORECAST SINCE IT SEEMED MORE QUESTIONABLE THEN AT AZO AND BTL. && .MARINE... ISSUED AT 316 AM EST THU NOV 13 2014 I CONTINUED THE SMALL CRAFT ADVISORY AS IS THROUGH FRIDAY AFTERNOON. IT WOULD SEEM HIGH PRESSURE BUILDING INTO THE AREA DURING FRIDAY AFTERNOON SHOULD DECREASE THE PRESSURE GRADIENT AND ALLOW WINDS AND WAVES TO FINALLY SUBSIDE. UNTIL THEN NORTHWEST WINDS OF 15 TO 25 KNOTS SHOULD PREVAIL. && .HYDROLOGY... ISSUED AT 310 PM EST WED NOV 12 2014 NO HYDROLOGY CONCERNS FOR THE NEXT WEEK WITH ANY PCPN OVER THE NEXT WEEK IN THE FORM OF SNOW AND UNSEASONABLY COLD TEMPS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST FRIDAY FOR MIZ037-038-043- 050-056-064-071-072. LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LMZ844>849. && $$ UPDATE...WDM SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...93 AVIATION...WDM HYDROLOGY...LAURENS MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
623 AM EST THU NOV 13 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 316 AM EST THU NOV 13 2014 SNOW SHOWERS...LOCALLY HEAVY ARE EXPECTED TODAY SOUTH OF INTERSTATE 96 AND WEST OF US-131. WHILE THE SNOW SHOWERS WILL DIMINISH SOME LATE THIS AFTERNOON THEY WILL CONTINUE INTO FRIDAY AFTERNOON RESULTING IN LOCAL ACCUMULATIONS AS HIGH AS 9 INCHES IN PARTS OF ALLEGAN AND OTTAWA COUNTIES. SNOW SHOWERS WILL ALSO RESULT IN 4 TO 6 INCHES OF SNOW WEST OF US-131 AND NORTH OF MUSKEGON INTO FRIDAY AFTERNOON. ELSEWHERE LIGHT SNOW SHOWERS WILL CONTINUE INTO FRIDAY WITH AN INCH OR LESS OF ACCUMULATION. THE UNSEASONABLY COLD TEMPERATURES...NEAR TO BELOW FREEZING WILL CONTINUE THROUGH MOST OF NEXT WEEK. THE SNOW SHOWERS SHOULD COME TO AN END SATURDAY ONLY TO START BACK UP ON SUNDAY AND CONTINUE INTO WEDNESDAY. A SECOND ARCTIC FRONT WILL BRING EVEN COLDER AIR IN THE TUESDAY TO WEDNESDAY TIME FRAME. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE WINTER WEATHER ADVISORY IS OUR PRIMARY FOCUS THIS MORNING. IT LOOKS VERY GOOD FOR THE HEAVIER SNOWFALL OVER OTTAWA AND ALLEGAN COUNTIES THIS MORNING BUT IT LOOKS LESS GOOD FOR THE HEAVIER SNOWFALLS OVER OUR NW CWA EVEN SO... I CONTINUED THE ADVISORY THERE SINCE THAT IS A TYPICAL PLACE FOR HEAVIER SNOW WITH A WEST TO NORTHWEST WIND FLOW. BASED ON THE LATEST DATA FROM OUR HIGH RESOLUTIONS MODELS... GETTING HEAVIER SNOWFALL AMOUNTS OVER OTTAWA AND ALLEGAN COUNTY THIS MORNING INTO EARLY THIS AFTERNOON STILL LOOKS GOOD. THE HEAVY SNOW BANDS ARE FORECAST TO OCCUR FROM MID MORNING INTO EARLY THIS AFTERNOON OVER ALLEGAN AND OTTAWA COUNTIES BY THE RAP...NAM AND HRRR MODELS. THE HRRR HAS CONSISTENTLY SHOWN 4 TO 7 INCHES BETWEEN 6 AM AND AND 2 PM THIS AFTERNOON IN TWO BANDS OVER OTTAWA AND ALLEGAN COUNTIES. THIS IS SIMILAR TO THE OUTPUT OF THE NAMDNG55. SINCE THE LATEST RADAR IS CURRENTLY SHOWING A SIGNIFICANT INCREASE IN INTENSITY AND BIV HAS SHOW VISIBILITIES DOWN TO NEAR 1 MILE ALREADY... I HAVE TO BELIEVE THE LOCALLY HEAVIER SNOW BANDS ARE MORE THAN POSSIBLE. WHAT ALSO GOES ALONG WITH THIS IS THE LIFT IF THE DGZ IS IMPRESSIVE ON ALL THREE MODELS OVER THOSE TWO COUNTIES. THE INVERSION HEIGHTS LIFT TO NEAR 11000 FT BY MID MORNING TOO. ALL OF THAT HELPS THE CAUSE OF HEAVIER SNOW BANDS IN OUR ADVISORY AREA. WHAT IS FORCING ALL OF THIS IS A SIGNIFICANT SHORTWAVE THAT MOVES THROUGH THE CWA DURING THE MIDDAY HOURS. IT IS THIS SHORTWAVE THE FINALLY PUSHES THE POLAR JET CORE SOUTH OF MICHIGAN. THAT WAS FORECAST TO HAPPEN SOONER BY EARLIER RUNS OF THE MODELS BUT THIS SHORTWAVE WILL DO THE TRICK AND PUT SOUTHWEST MICHIGAN IN THE DEEP COLD AIR INTO FRIDAY EVENING. ONCE THE SHORTWAVE IS THROUGH THE INTENSITY OF THE SNOW SHOWERS WILL DECREASE BUT WE WILL STILL HAVE LIFT IN THE DGZ WITH NEAR SATURATION DUE OVER ICE THROUGH FRIDAY AFTERNOON SO THE SNOW SHOWERS WILL CONTINUE INTO FRIDAY AFTERNOON FOR SURE. FRIDAY NIGHT INTO SATURDAY THE SURFACE HIGH MOVES IN AND BY MID MORNING SATURDAY THE AIR BECOMES SO DRY THAT GETTING LAKE EFFECT CLOUDS WILL HE HARD TO DO...EVEN WITH THE 20C DIFFERENCE BETWEEN THE LAKE TEMPERATURE AND 850 MB. SO WE SHOULD FINALLY SEE A DRY PERIOD. INLAND AREAS TODAY THROUGH FRIDAY WILL SEE OCCASIONAL SNOW SHOWER WITH THE HELP OF DAY TIME MIXING BRINGING THE SHOWER INLAND. ALSO THE WEST NORTHWEST WINDS WILL HELP THAT CAUSE TOO. TEMPERATURES SHOULD LARGELY STAY NEAR TO BELOW FREEZING ALL THREE AFTERNOONS AND FALL INTO THE 20S AT NIGHT. CLOUDS DUE TO THE WEST TO NORTHWEST WINDS WILL KEEP IT FROM GETTING MUCH COLDER THAN THAT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE COLD SNOWY PATTERN WILL CONTINUE THROUGH THE LONG TERM. HOWEVER BY LATE WEDNESDAY...MODELS ARE HINTING THAT THE CORE OF THE COLD AIR WILL START TO LIFT OUT. THE MAIN FOCUS IS ON MONDAY AND TUESDAY. THAT/S THE TIME FRAME WHEN A DEEP TROUGH WILL MOVE OVER THE GREAT LAKES AND PRODUCE ANOTHER BLAST OF ARCTIC AIR. BOTH THE GFS AND ECMWF ARE SIMILAR IN TIMING AND STRENGTH OF THE UPPER TROUGH. H8 TEMPS FALL TO -16C BY TUESDAY AFTERNOON. WNW BOUNDARY LAYER WINDS SHOULD RESULT IN LAKE EFFECT SNOW MONDAY THROUGH TUESDAY. THE DGZ DOES FALL TO AROUND 4K FT...BUT IS PRETTY TYPICAL FOR THIS TYPE OF COLD AIR. WE/RE LIKELY GOING TO SEE SEVERAL INCHES OF SNOWFALL DURING THIS TIME FRAME AND WE BOOSTED POPS TO ACCOUNT FOR IT. PRIOR TO THE BLAST OF ARCTIC AIR ARRIVING SUNDAY NIGHT...WE/LL SEE SOME WARM AIR ADVECTION SNOW SATURDAY NIGHT THAT WILL CONTINUE INTO SUNDAY. ACCUMS IN THE 1-3 INCH RANGE LOOK REASONABLE SATURDAY NIGHT BASED ON MIXING RATIOS AND THE STRENGTH OF THE ISENTROPIC LIFT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 622 AM EST THU NOV 13 2014 LAKE EFFECT SNOW SHOWERS WILL PREVAIL THROUGH TOMORROW BUT THE MORE INTENSE SNOW SHOWERS WILL BE THIS MORNING...NEAR THE LAKE SHORE (MKG)...POSSIBLY REACHING GRR AND AZO/BTL. LAN AND JXN SHOULD MOSTLY BE MVFR WITH CIGS AND OCNL SNOW SHOWERS. THE TAFS ARE WRITTEN TO SHOW MOSTLY VFR CONDITIONS AFTER 18Z BUT I DO EXPECT THE SNOW BANDS TO MOVE BACK INTO AZO /BTL BY EARLY EVENING SO I TOOK THEM TO IFR AFTER 02Z. THOSE SNOW BANDS MAY ALSO IMPACT MKG AND GRR BUT I DID NOT SHOW THAT IN THE TAF FORECAST SINCE IT SEEMED MORE QUESTIONABLE THEN AT AZO AND BTL. && .MARINE... ISSUED AT 316 AM EST THU NOV 13 2014 I CONTINUED THE SMALL CRAFT ADVISORY AS IS THROUGH FRIDAY AFTERNOON. IT WOULD SEEM HIGH PRESSURE BUILDING INTO THE AREA DURING FRIDAY AFTERNOON SHOULD DECREASE THE PRESSURE GRADIENT AND ALLOW WINDS AND WAVES TO FINALLY SUBSIDE. UNTIL THEN NORTHWEST WINDS OF 15 TO 25 KNOTS SHOULD PREVAIL. && .HYDROLOGY... ISSUED AT 310 PM EST WED NOV 12 2014 NO HYDROLOGY CONCERNS FOR THE NEXT WEEK WITH ANY PCPN OVER THE NEXT WEEK IN THE FORM OF SNOW AND UNSEASONABLY COLD TEMPS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST FRIDAY FOR MIZ037-038-043- 056-064-071-072. LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LMZ844>849. && $$ SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...93 AVIATION...WDM HYDROLOGY...LAURENS MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
318 AM EST THU NOV 13 2014 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/MARINE .SYNOPSIS... ISSUED AT 316 AM EST THU NOV 13 2014 SNOW SHOWERS...LOCALLY HEAVY ARE EXPECTED TODAY SOUTH OF INTERSTATE 96 AND WEST OF US-131. WHILE THE SNOW SHOWERS WILL DIMINISH SOME LATE THIS AFTERNOON THEY WILL CONTINUE INTO FRIDAY AFTERNOON RESULTING IN LOCAL ACCUMULATIONS AS HIGH AS 9 INCHES IN PARTS OF ALLEGAN AND OTTAWA COUNTIES. SNOW SHOWERS WILL ALSO RESULT IN 4 TO 6 INCHES OF SNOW WEST OF US-131 AND NORTH OF MUSKEGON INTO FRIDAY AFTERNOON. ELSEWHERE LIGHT SNOW SHOWERS WILL CONTINUE INTO FRIDAY WITH AN INCH OR LESS OF ACCUMULATION. THE UNSEASONABLY COLD TEMPERATURES...NEAR TO BELOW FREEZING WILL CONTINUE THROUGH MOST OF NEXT WEEK. THE SNOW SHOWERS SHOULD COME TO AN END SATURDAY ONLY TO START BACK UP ON SUNDAY AND CONTINUE INTO WEDNESDAY. A SECOND ARCTIC FRONT WILL BRING EVEN COLDER AIR IN THE TUESDAY TO WEDNESDAY TIME FRAME. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE WINTER WEATHER ADVISORY IS OUR PRIMARY FOCUS THIS MORNING. IT LOOKS VERY GOOD FOR THE HEAVIER SNOWFALL OVER OTTAWA AND ALLEGAN COUNTIES THIS MORNING BUT IT LOOKS LESS GOOD FOR THE HEAVIER SNOWFALLS OVER OUR NW CWA EVEN SO... I CONTINUED THE ADVISORY THERE SINCE THAT IS A TYPICAL PLACE FOR HEAVIER SNOW WITH A WEST TO NORTHWEST WIND FLOW. BASED ON THE LATEST DATA FROM OUR HIGH RESOLUTIONS MODELS... GETTING HEAVIER SNOWFALL AMOUNTS OVER OTTAWA AND ALLEGAN COUNTY THIS MORNING INTO EARLY THIS AFTERNOON STILL LOOKS GOOD. THE HEAVY SNOW BANDS ARE FORECAST TO OCCUR FROM MID MORNING INTO EARLY THIS AFTERNOON OVER ALLEGAN AND OTTAWA COUNTIES BY THE RAP...NAM AND HRRR MODELS. THE HRRR HAS CONSISTENTLY SHOWN 4 TO 7 INCHES BETWEEN 6 AM AND AND 2 PM THIS AFTERNOON IN TWO BANDS OVER OTTAWA AND ALLEGAN COUNTIES. THIS IS SIMILAR TO THE OUTPUT OF THE NAMDNG55. SINCE THE LATEST RADAR IS CURRENTLY SHOWING A SIGNIFICANT INCREASE IN INTENSITY AND BIV HAS SHOW VISIBILITIES DOWN TO NEAR 1 MILE ALREADY... I HAVE TO BELIEVE THE LOCALLY HEAVIER SNOW BANDS ARE MORE THAN POSSIBLE. WHAT ALSO GOES ALONG WITH THIS IS THE LIFT IF THE DGZ IS IMPRESSIVE ON ALL THREE MODELS OVER THOSE TWO COUNTIES. THE INVERSION HEIGHTS LIFT TO NEAR 11000 FT BY MID MORNING TOO. ALL OF THAT HELPS THE CAUSE OF HEAVIER SNOW BANDS IN OUR ADVISORY AREA. WHAT IS FORCING ALL OF THIS IS A SIGNIFICANT SHORTWAVE THAT MOVES THROUGH THE CWA DURING THE MIDDAY HOURS. IT IS THIS SHORTWAVE THE FINALLY PUSHES THE POLAR JET CORE SOUTH OF MICHIGAN. THAT WAS FORECAST TO HAPPEN SOONER BY EARLIER RUNS OF THE MODELS BUT THIS SHORTWAVE WILL DO THE TRICK AND PUT SOUTHWEST MICHIGAN IN THE DEEP COLD AIR INTO FRIDAY EVENING. ONCE THE SHORTWAVE IS THROUGH THE INTENSITY OF THE SNOW SHOWERS WILL DECREASE BUT WE WILL STILL HAVE LIFT IN THE DGZ WITH NEAR SATURATION DUE OVER ICE THROUGH FRIDAY AFTERNOON SO THE SNOW SHOWERS WILL CONTINUE INTO FRIDAY AFTERNOON FOR SURE. FRIDAY NIGHT INTO SATURDAY THE SURFACE HIGH MOVES IN AND BY MID MORNING SATURDAY THE AIR BECOMES SO DRY THAT GETTING LAKE EFFECT CLOUDS WILL HE HARD TO DO...EVEN WITH THE 20C DIFFERENCE BETWEEN THE LAKE TEMPERATURE AND 850 MB. SO WE SHOULD FINALLY SEE A DRY PERIOD. INLAND AREAS TODAY THROUGH FRIDAY WILL SEE OCCASIONAL SNOW SHOWER WITH THE HELP OF DAY TIME MIXING BRINGING THE SHOWER INLAND. ALSO THE WEST NORTHWEST WINDS WILL HELP THAT CAUSE TOO. TEMPERATURES SHOULD LARGELY STAY NEAR TO BELOW FREEZING ALL THREE AFTERNOONS AND FALL INTO THE 20S AT NIGHT. CLOUDS DUE TO THE WEST TO NORTHWEST WINDS WILL KEEP IT FROM GETTING MUCH COLDER THAN THAT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 316 AM EST THU NOV 13 2014 THE COLD SNOWY PATTERN WILL CONTINUE THROUGH THE LONG TERM. HOWEVER BY LATE WEDNESDAY...MODELS ARE HINTING THAT THE CORE OF THE COLD AIR WILL START TO LIFT OUT. THE MAIN FOCUS IS ON MONDAY AND TUESDAY. THAT/S THE TIME FRAME WHEN A DEEP TROUGH WILL MOVE OVER THE GREAT LAKES AND PRODUCE ANOTHER BLAST OF ARCTIC AIR. BOTH THE GFS AND ECMWF ARE SIMILAR IN TIMING AND STRENGTH OF THE UPPER TROUGH. H8 TEMPS FALL TO -16C BY TUESDAY AFTERNOON. WNW BOUNDARY LAYER WINDS SHOULD RESULT IN LAKE EFFECT SNOW MONDAY THROUGH TUESDAY. THE DGZ DOES FALL TO AROUND 4K FT...BUT IS PRETTY TYPICAL FOR THIS TYPE OF COLD AIR. WE/RE LIKELY GOING TO SEE SEVERAL INCHES OF SNOWFALL DURING THIS TIME FRAME AND WE BOOSTED POPS TO ACCOUNT FOR IT. PRIOR TO THE BLAST OF ARCTIC AIR ARRIVING SUNDAY NIGHT...WE/LL SEE SOME WARM AIR ADVECTION SNOW SATURDAY NIGHT THAT WILL CONTINUE INTO SUNDAY. ACCUMS IN THE 1-3 INCH RANGE LOOK REASONABLE SATURDAY NIGHT BASED ON MIXING RATIOS AND THE STRENGTH OF THE ISENTROPIC LIFT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1240 AM EST THU NOV 13 2014 SNOW SHOWERS WILL INCREASE IN INTENSITY AND BE MOST NUMEROUS WEST OF US-131. VISIBILITIES WILL FALL TO 1 1/2-2SM AT KMKG/KAZO/KBTL THROUGH MID MORNING BEFORE RISING AGAIN AS THE A TROUGH MOVES THROUGH. SHSN WILL DIMINISH LATER THIS AFTERNOON. && .MARINE... ISSUED AT 316 AM EST THU NOV 13 2014 I CONTINUED THE SMALL CRAFT ADVISORY AS IS THROUGH FRIDAY AFTERNOON. IT WOULD SEEM HIGH PRESSURE BUILDING INTO THE AREA DURING FRIDAY AFTERNOON SHOULD DECREASE THE PRESSURE GRADIENT AND ALLOW WINDS AND WAVES TO FINALLY SUBSIDE. UNTIL THEN NORTHWEST WINDS OF 15 TO 25 KNOTS SHOULD PREVAIL. && .HYDROLOGY... ISSUED AT 310 PM EST WED NOV 12 2014 NO HYDROLOGY CONCERNS FOR THE NEXT WEEK WITH ANY PCPN OVER THE NEXT WEEK IN THE FORM OF SNOW AND UNSEASONABLY COLD TEMPS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST FRIDAY FOR MIZ037-038-043- 056-064-071-072. LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LMZ844>849. && $$ SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...93 AVIATION...93 HYDROLOGY...LAURENS MARINE...WDM
AREA FORECAST DISCUSSION
NWS JACKSON MS
1010 AM CST THU NOV 13 2014 .UPDATE...A RATHER CHILLY MORNING WAS STILL BEING OBSERVED OVER THE ARKLAMISS AS 10AM TEMPERATURES WERE STILL IN THE 30S AND A GUSTY NORTH WIND CHILL TEMPERATURES BELOW FREEZING. SPLIT FLOW REGIME WITH NORTHERN STREAM SHORTWAVE AND A SOUTHERN STREAM SHORTWAVE MOVING ACROSS OUR CWA WAS RESULTING IN VERY LIT RAIN OVER PORTIONS OF THE CWA. THE NORTHERN STREAM SHORTWAVE IS ALMOST EAST OF OUR CWA AND A VERY NARROW BAND OF MOSTLY SPRINKLES HAS SHIFTED EAST OF GRANADA. EARLIER THIS MORNING A REPORT OF LIGHT SLEET MIXED WITH THE RAIN WAS NOTED IN NORTHERN BOLIVAR COUNTY WITH THIS BAND BUT NO IMPACTS OCCURRED DUE TO THE BRIEF DURATION AND VERY LIGHT AMOUNTS. IN THE SOUTH THE SOUTHERN STREAM SHORTWAVE WAS STILL HELPING PRODUCE A BAND OF LIGHT RAIN ALONG THE HIGHWAY 84 CORRIDOR. THIS BAND OF RAIN WILL SHIFT EAST AND END OVER OUR CWA AS THE SHORTWAVE SHIFTS EAST AS WELL. CLOUD COVER SHOULD BREAK UP THIS AFTERNOON AND ALLOW SOME SUNSHINE THROUGH. THIS WILL AID TEMPERATURES IN RISING INTO THE 40S. HAVE ADJUSTED CLOUD COVER AND DEW POINTS THIS WITH THE UPDATE BUT THE REMAINDER OF THE FORECAST IS ON TRACK. /22/ && .AVIATION...A MIX OF MVFR/VFR CONDITIONS WILL PREVAIL ACROSS THE ARKLAMISS THIS MORNING INTO THE AFTERNOON HOURS. A FEW VERY LIGHT RAINSHOWERS ARE POSSIBLE AT HBG THIS MORNING ALSO. EXPECT ALL SITES TO BECOME VFR AFTER 19-20Z WITH MAINLY CLEAR SKIES AFTER 14/00Z. THE WINDS WILL BE OUT OF THE NORTH AT 6-10KTS WITH GUSTS FROM 15-20KTS AT GLH/GWO BECOMING 4-8KTS OUT OF THE NORTH OVERNIGHT./15/ && .PREV DISCUSSION... /ISSUED 402 AM CST THU NOV 13 2014/ SHORT TERM...TODAY THROUGH FRIDAY NIGHT...LOW CLOUDS CONTINUE TO PUSH OFF TO THE EAST AS THE COLD/DRY AIR STEADILY BUILDS INTO THE REGION. MEANWHILE...MID/HIGH CLOUDS ARE ON THE INCREASE AS SHORTWAVE MOVING THROUGH THE BASE OF H5 TROF HAS TAPPED AVAILABLE MOISTURE OVER THE NORTHERN GULF OF MEXICO. ALREADY...ISENTROPIC LIFT HAS ALLOWED AREA OF RAIN TO BREAK OUT ALONG THE LA COAST...BUT THE MAJORITY DOES NOT APPEAR TO BE REACHING THE GROUND. HRRR IS ALSO INDICATING WINTRY PRECIP OVER ARKANSAS...BUT THIS AREA SHOULD JUST GRAZE OUR EXTREME NORTHERN AREAS EARLY AS IT RAPIDLY HEADS EAST. THE SLUG OF MOISTURE AND LIFT FROM THE NORTHERN GULF WILL MAINLY AFFECT SOUTH MS THIS MORNING AND QUICKLY PULL EAST ALONG WITH THE CLOUD COVER THIS AFTERNOON. WOULD NOT BE SURPRISED TO HEAR OF A FEW ICE PELLETS MIXED IN WITH THE LIGHT RAIN ON THE NORTHERN FRINGES GIVEN DRY/COLD AIR IN THE COLUMN AS INDICATED IN THE BUFR DATA PROFILES. WITH THE DRY AIR IN PLACE...EXPECT DECOUPLING AND STRONG RADIATIVE COOLING TO BEGIN AFTER SUNSET ALLOWING TEMPS TO DROP RAPIDLY. WILL UPGRADE THE FREEZE WATCH TO A WARNING AS EXPECT MID 20S TO BE WIDESPREAD ACROSS THE FORECAST AREA BY EARLY FRIDAY MORNING. THIS FREEZE SHOULD KILL ANY REMAINING LIVE VEGETATION. TEMPS WILL BE SLOW TO MODERATE MUCH IF ANY FRIDAY AS NORTHERLY WINDS CONTINUE TO USHER THE COOL AIR SOUTHWARD. TWENTIES LOOK LIKE A GOOD BET AGAIN FRIDAY NIGHT...SLIGHTLY WARMER UPPER 20S OVER THE SOUTH AND WEST AS SURFACE HIGH PRESSURE PUSHES EAST AND WINDS SWITCH TO THE SOUTH./26/ LONG TERM...SATURDAY THROUGH NEXT THURSDAY...THE TWO MAIN STORIES OF THIS PERIOD WILL BE THE WIDESPREAD RAIN EXPECTED SUNDAY INTO EARLY MONDAY AND THE SUBSTANTIAL COLD TEMPERATURES THAT WILL FOLLOW EARLY TO MID-NEXT WEEK. 1) RAIN TOTALS WILL RANGE FROM 1-2 INCHES AND SOME LOCALLY HIGHER AMOUNTS NEAR 3 INCHES COULD BE POSSIBLE. 2) TEMPERATURES WILL PLUNGE MID-WEEK WITH SEVERAL HARD FREEZES LIKELY INTO THE LOW AND MID 20S. OVERALL MODEL ENVELOPE HAS GOOD SYNOPTIC PATTERN AGREEMENT THROUGH PERIOD INDICATING A STRONG BAROCLINIC ZONE ALONG THE NORTHERN GULF INTERACTING WITH SEVERAL EMBEDDED H5 S/WV TROUGHS THAT WILL EJECT OUT AHEAD OF A MORE POTENT PACIFIC ORIGINATED LONGWAVE TROUGH BY SUNDAY INTO EARLY MONDAY. SURFACE LOW CYCLOGENESIS SHOULD OCCUR ALONG THE BAROCLINIC ZONE AND COUPLED WITH UPPER DIVERGENCE FROM INCREASING FRONT ENTRANCE JET MAGNITUDE WILL AID IN LARGE RAIN SHIELD SUNDAY INTO EARLY MONDAY. THIS PACIFIC TROUGH SHOULD THEN PHASE WITH A POLAR ORIGINATED TROUGH LATE MONDAY INTO TUESDAY THAT WILL USHER -3 TO -4 SD H925 TEMPS OVER THE REGION. THIS WILL LEAD TO SEVERAL HARD FREEZES WITH WIDESPREAD LOW TEMPERATURES OF MID 20S AND HIGHS MAINLY IN THE 40S. FOR SENSIBLE WEATHER DETAILS, RAIN CHANCES WERE BOOSTED SUNDAY AND OVERNIGHT INTO EARLY MONDAY WITH A CONTINUED SLOWING TREND WITH HIGH CONFIDENCE OF RAIN. EXPECT A COLD RAIN SUNDAY INTO EARLY MONDAY WITH HEAVIEST RAIN ALONG AND SOUTH OF NATCHEZ TRACE CORRIDOR. INTRODUCED SLIGHT CHANCE THUNDER AS SLIGHTLY NEGATIVE SHOWALTERS AND HIGHER VERTICAL TOTALS (25C) WILL BE INVOF DIRECT CIRCULATION AND JET INDUCED DIVERGENCE THAT WILL ACT TO INCREASE RAINFALL RATE POCKETS. MODELS ARE NOT AS STRONG ON SURFACE LOW DEVELOPMENT VS. PREVIOUS RUNS AND THUS COLD AIR DOES NOT LOOK TO FILTER IN FAST ENOUGH ON BACKSIDE FOR ANY WINTER PRECIP CHANGEOVER. HAVE KEPT OUT ANY WINTER MIX AT THIS POINT. FROM MONDAY THROUGH WEDNESDAY, BOTH MAX HIGHS AND MIN LOWS WERE DROPPED 2-4F DEGREES TO BE MORE IN LINE WITH RAW MODEL GUIDANCE. NEXT TUESDAY LOOKS QUITE COLD AS LOWS SHOULD FALL INTO THE LOW TO MID 20S WITH AFTERNOON TEMPS ONLY RECOVERING INTO MID/UPPER 30S NORTH TO NEAR 40S SOUTH. WIND CHILLS COULD FALL INTO THE TEENS TUESDAY MORNING AND NOT FULLY RECOVER ABOVE FREEZING THROUGH THE DAY. A SLOW WARMING PATTERN SHOULD OCCUR GOING INTO LATE WEEK BUT TEMPS WILL REMAIN BELOW NORMAL. /ALLEN/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 44 25 45 27 / 12 2 5 3 MERIDIAN 46 23 47 26 / 13 2 4 3 VICKSBURG 43 24 45 27 / 11 2 3 3 HATTIESBURG 44 25 48 27 / 25 2 4 3 NATCHEZ 41 23 45 28 / 17 2 4 3 GREENVILLE 41 24 41 27 / 8 1 3 3 GREENWOOD 41 22 42 25 / 8 2 3 3 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...FREEZE WARNING FROM 11 PM THIS EVENING TO 8 AM CST FRIDAY FOR MSZ018-019-025>066-072>074. LA...FREEZE WARNING FROM 11 PM THIS EVENING TO 8 AM CST FRIDAY FOR LAZ007>009-015-016-023>026. AR...FREEZE WARNING FROM 11 PM THIS EVENING TO 8 AM CST FRIDAY FOR ARZ074-075. && $$ 22/15/26/ALLEN
AREA FORECAST DISCUSSION
NWS JACKSON MS
402 AM CST THU NOV 13 2014 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT...LOW CLOUDS CONTINUE TO PUSH OFF TO THE EAST AS THE COLD/DRY AIR STEADILY BUILDS INTO THE REGION. MEANWHILE...MID/HIGH CLOUDS ARE ON THE INCREASE AS SHORTWAVE MOVING THROUGH THE BASE OF H5 TROF HAS TAPPED AVAILABLE MOISTURE OVER THE NORTHERN GULF OF MEXICO. ALREADY...ISENTROPIC LIFT HAS ALLOWED AREA OF RAIN TO BREAK OUT ALONG THE LA COAST...BUT THE MAJORITY DOES NOT APPEAR TO BE REACHING THE GROUND. HRRR IS ALSO INDICATING WINTRY PRECIP OVER ARKANSAS...BUT THIS AREA SHOULD JUST GRAZE OUR EXTREME NORTHERN AREAS EARLY AS IT RAPIDLY HEADS EAST. THE SLUG OF MOISTURE AND LIFT FROM THE NORTHERN GULF WILL MAINLY AFFECT SOUTH MS THIS MORNING AND QUICKLY PULL EAST ALONG WITH THE CLOUD COVER THIS AFTERNOON. WOULD NOT BE SURPRISED TO HEAR OF A FEW ICE PELLETS MIXED IN WITH THE LIGHT RAIN ON THE NORTHERN FRINGES GIVEN DRY/COLD AIR IN THE COLUMN AS INDICATED IN THE BUFR DATA PROFILES. WITH THE DRY AIR IN PLACE...EXPECT DECOUPLING AND STRONG RADIATIVE COOLING TO BEGIN AFTER SUNSET ALLOWING TEMPS TO DROP RAPIDLY. WILL UPGRADE THE FREEZE WATCH TO A WARNING AS EXPECT MID 20S TO BE WIDESPREAD ACROSS THE FORECAST AREA BY EARLY FRIDAY MORNING. THIS FREEZE SHOULD KILL ANY REMAINING LIVE VEGETATION. TEMPS WILL BE SLOW TO MODERATE MUCH IF ANY FRIDAY AS NORTHERLY WINDS CONTINUE TO USHER THE COOL AIR SOUTHWARD. TWENTIES LOOK LIKE A GOOD BET AGAIN FRIDAY NIGHT...SLIGHTLY WARMER UPPER 20S OVER THE SOUTH AND WEST AS SURFACE HIGH PRESSURE PUSHES EAST AND WINDS SWITCH TO THE SOUTH./26/ .LONG TERM...SATURDAY THROUGH NEXT THURSDAY...THE TWO MAIN STORIES OF THIS PERIOD WILL BE THE WIDESPREAD RAIN EXPECTED SUNDAY INTO EARLY MONDAY AND THE SUBSTANTIAL COLD TEMPERATURES THAT WILL FOLLOW EARLY TO MID-NEXT WEEK. 1) RAIN TOTALS WILL RANGE FROM 1-2 INCHES AND SOME LOCALLY HIGHER AMOUNTS NEAR 3 INCHES COULD BE POSSIBLE. 2) TEMPERATURES WILL PLUNGE MID-WEEK WITH SEVERAL HARD FREEZES LIKELY INTO THE LOW AND MID 20S. OVERALL MODEL ENVELOPE HAS GOOD SYNOPTIC PATTERN AGREEMENT THROUGH PERIOD INDICATING A STRONG BAROCLINIC ZONE ALONG THE NORTHERN GULF INTERACTING WITH SEVERAL EMBEDDED H5 S/WV TROUGHS THAT WILL EJECT OUT AHEAD OF A MORE POTENT PACIFIC ORIGINATED LONGWAVE TROUGH BY SUNDAY INTO EARLY MONDAY. SURFACE LOW CYCLOGENESIS SHOULD OCCUR ALONG THE BAROCLINIC ZONE AND COUPLED WITH UPPER DIVERGENCE FROM INCREASING FRONT ENTRANCE JET MAGNITUDE WILL AID IN LARGE RAIN SHIELD SUNDAY INTO EARLY MONDAY. THIS PACIFIC TROUGH SHOULD THEN PHASE WITH A POLAR ORIGINATED TROUGH LATE MONDAY INTO TUESDAY THAT WILL USHER -3 TO -4 SD H925 TEMPS OVER THE REGION. THIS WILL LEAD TO SEVERAL HARD FREEZES WITH WIDESPREAD LOW TEMPERATURES OF MID 20S AND HIGHS MAINLY IN THE 40S. FOR SENSIBLE WEATHER DETAILS, RAIN CHANCES WERE BOOSTED SUNDAY AND OVERNIGHT INTO EARLY MONDAY WITH A CONTINUED SLOWING TREND WITH HIGH CONFIDENCE OF RAIN. EXPECT A COLD RAIN SUNDAY INTO EARLY MONDAY WITH HEAVIEST RAIN ALONG AND SOUTH OF NATCHEZ TRACE CORRIDOR. INTRODUCED SLIGHT CHANCE THUNDER AS SLIGHTLY NEGATIVE SHOWALTERS AND HIGHER VERTICAL TOTALS (25C) WILL BE INVOF DIRECT CIRCULATION AND JET INDUCED DIVERGENCE THAT WILL ACT TO INCREASE RAINFALL RATE POCKETS. MODELS ARE NOT AS STRONG ON SURFACE LOW DEVELOPMENT VS. PREVIOUS RUNS AND THUS COLD AIR DOES NOT LOOK TO FILTER IN FAST ENOUGH ON BACKSIDE FOR ANY WINTER PRECIP CHANGEOVER. HAVE KEPT OUT ANY WINTER MIX AT THIS POINT. FROM MONDAY THROUGH WEDNESDAY, BOTH MAX HIGHS AND MIN LOWS WERE DROPPED 2-4F DEGREES TO BE MORE IN LINE WITH RAW MODEL GUIDANCE. NEXT TUESDAY LOOKS QUITE COLD AS LOWS SHOULD FALL INTO THE LOW TO MID 20S WITH AFTERNOON TEMPS ONLY RECOVERING INTO MID/UPPER 30S NORTH TO NEAR 40S SOUTH. WIND CHILLS COULD FALL INTO THE TEENS TUESDAY MORNING AND NOT FULLY RECOVER ABOVE FREEZING THROUGH THE DAY. A SLOW WARMING PATTERN SHOULD OCCUR GOING INTO LATE WEEK BUT TEMPS WILL REMAIN BELOW NORMAL. /ALLEN/ && .AVIATION...THOUGH MID/HIGH LEVEL CEILINGS WILL EXIST FOR THE MAJORITY OF THE PERIOD...VFR CONDITIONS WILL PREVAIL. AREAS OF RAIN WILL BE POSSIBLE IN THE HBG VICINITY TODAY...BUT SHOULD NOT BE HEAVY ENOUGH TO CREATE ANY OBSTRUCTION TO VISIBILITY. SKIES WILL CLEAR AFTER 14/00Z./26/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 44 25 45 27 / 12 2 5 3 MERIDIAN 46 23 47 26 / 13 2 4 3 VICKSBURG 43 24 45 27 / 11 2 3 3 HATTIESBURG 44 25 48 27 / 25 2 4 3 NATCHEZ 41 23 45 28 / 17 2 4 3 GREENVILLE 41 24 41 27 / 8 1 3 3 GREENWOOD 41 22 42 25 / 8 2 3 3 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...FREEZE WARNING FROM 11 PM THIS EVENING TO 8 AM CST FRIDAY FOR MSZ018-019-025>066-072>074. LA...FREEZE WARNING FROM 11 PM THIS EVENING TO 8 AM CST FRIDAY FOR LAZ007>009-015-016-023>026. AR...FREEZE WARNING FROM 11 PM THIS EVENING TO 8 AM CST FRIDAY FOR ARZ074-075. && $$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1228 PM CST THU NOV 13 2014 .UPDATE... ISSUED AT 1225 PM CST THU NOV 13 2014 AREAS OF LOW STRATUS REMAIN OVER THE AREA WITH SOME FLURRIES CONTINUING. FOR EARLY AFTERNOON UPDATE HAVE EXTENDED THE TIMING OF THE CLOUD COVER...ERODING IT OUT LATER THIS AFTERNOON INTO THE EVENING. UPDATE ISSUED AT 844 AM CST THU NOV 13 2014 BROAD AREA OF STATUS REMAINS OVER MUCH OF WESTERN INTO CENTRAL NORTH DAKOTA WHICH MODELS ARE STILL HAVING TROUBLE WITH. WILL KEEP CLOUDS IN PLACE THROUGH MID-DAY BEFORE STARTING TO ERODE OUT. HAVE ADDED MENTION OF FLURRIES UNDER THE CLOUD COVER THROUGH MID-DAY AS VARIOUS POINTS ARE REPORTING SNOW...BUT LITTLE TO NO REDUCTION IN VISIBILITIES. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 607 AM CST THU NOV 13 2014 THE 06 UTC DETERMINISTIC SUITE AND 09-11 UTC RAP/HRRR ITERATIONS ARE HAVING A DIFFICULT TIME RESOLVING THE LOW LEVEL STRATUS FIELD THAT CONTINUES TO SLOWLY EXPAND ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. THE 10 UTC LAMP IS REALLY THE ONLY GUIDANCE PICKING UP ON THE STRATUS. THUS...WILL MAINTAIN THE STRATUS AS OBSERVED THROUGH 12 UTC...SLOWLY ERODING IT THROUGH THE AFTERNOON AS THE SURFACE HIGH AXIS ACROSS EASTERN MONTANA PROPAGATES EAST. HOWEVER...CONFIDENCE IN HOW THE STRATUS WILL EVOLVE IS LOW. ALSO ADDED FLURRIES TO LOCATIONS UNDER THE STRATUS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST THU NOV 13 2014 CLOUDS CONTINUE TO INCREASE ACROSS THE AREA THIS MORNING. THIS IS ALLOWING TEMPERATURES TO MODERATE SOMEWHAT ACROSS THE REGION THIS MORNING. CLOUDS ARE EXPECTED TO THIN OUT THROUGH THE DAY. VERY HIGH PRESSURE WILL CONTINUE TO SETTLE ACROSS THE AREA TODAY. HIGH TEMPERATURES TODAY WILL ONLY RISE INTO THE LOW TEENS. TONIGHT THE RAP IS FORECASTING A 1042 MB HIGH ACROSS SOUTHWEST NORTH DAKOTA. THIS IS RATHER ANOMALOUS ANYTIME DURING WINTER...BUT ESPECIALLY THIS EARLY. THIS VERY COLD HIGH PRESSURE CENTER WILL AID IN TEMPERATURES FALLING INTO THE TEENS BELOW ZERO ACROSS THE SOUTHWEST. COMBINE A LIGHT WIND WITH THESE TEMPERATURES AND YOU HAVE WIND CHILL READINGS IN THE 20S BELOW ZERO. THIS WILL LIKELY WARRANT A WIND CHILL HEADLINE. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 314 AM CST THU NOV 13 2014 CONTINUED COLD THROUGH THE PERIOD AND BLOWING SNOW POTENTIAL SUNDAY HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES TO DEPICT A BLOCKING HIGH AMPLITUDE UPPER LEVEL RIDGE ACROSS THE EASTERN PACIFIC AND AN ANOMALOUSLY DEEP LONG WAVE TROUGH ACROSS THE CENTRAL AND EASTERN CONUS REMAINING THROUGH THE EXTENDED. THIS PATTERNS PROPAGATES VERY SLOWLY EAST THROUGH THE PERIOD...WHICH MAY ALLOW FOR A RELATIVE WARM UP INTO STILL BELOW NORMAL HIGHS IN THE 20S BY MID NEXT WEEK. PRIOR TO THIS...HIGHS GENERALLY IN THE TEENS ARE EXPECTED WITH WIND CHILLS EACH NIGHT AND EARLY MORNING APPROACHING BUT STAYING JUST WARMER THAN ADVISORY CRITERIA OF -25. THE 00 UTC SUITE IS ALSO IN AGREEMENT ON A CLIPPER SYSTEM TO IMPACT THE NORTHERN PLAINS ON SUNDAY. STRONG WINDS BEHIND THE REINFORCING COLD SURGE MAY LEAD TO BLOWING SNOW...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTH CENTRAL WHERE SNOW DEPTHS ARE GREATEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1225 PM CST THU NOV 13 2014 AREAS OF MVFR CIGS WILL CONTINUE OVER WESTERN AND CENTRAL NORTH DAKOTA THROUGH MID-AFTERNOON. CIGS ARE THEN EXPECTED TO IMPROVE TO VFR THROUGH THE LATE AFTERNOON/EARLY EVENING...AND WILL REMAIN VFR THROUGH THE REMAINDER OF THE FORECAST PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...AJ LONG TERM...AYD AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
853 AM CST THU NOV 13 2014 .UPDATE... ISSUED AT 844 AM CST THU NOV 13 2014 BROAD AREA OF STATUS REMAINS OVER MUCH OF WESTERN INTO CENTRAL NORTH DAKOTA WHICH MODELS ARE STILL HAVING TROUBLE WITH. WILL KEEP CLOUDS IN PLACE THROUGH MID-DAY BEFORE STARTING TO ERODE OUT. HAVE ADDED MENTION OF FLURRIES UNDER THE CLOUD COVER THROUGH MID-DAY AS VARIOUS POINTS ARE REPORTING SNOW...BUT LITTLE TO NO REDUCTION IN VISIBILITIES. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 607 AM CST THU NOV 13 2014 THE 06 UTC DETERMINISTIC SUITE AND 09-11 UTC RAP/HRRR ITERATIONS ARE HAVING A DIFFICULT TIME RESOLVING THE LOW LEVEL STRATUS FIELD THAT CONTINUES TO SLOWLY EXPAND ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. THE 10 UTC LAMP IS REALLY THE ONLY GUIDANCE PICKING UP ON THE STRATUS. THUS...WILL MAINTAIN THE STRATUS AS OBSERVED THROUGH 12 UTC...SLOWLY ERODING IT THROUGH THE AFTERNOON AS THE SURFACE HIGH AXIS ACROSS EASTERN MONTANA PROPAGATES EAST. HOWEVER...CONFIDENCE IN HOW THE STRATUS WILL EVOLVE IS LOW. ALSO ADDED FLURRIES TO LOCATIONS UNDER THE STRATUS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST THU NOV 13 2014 CLOUDS CONTINUE TO INCREASE ACROSS THE AREA THIS MORNING. THIS IS ALLOWING TEMPERATURES TO MODERATE SOMEWHAT ACROSS THE REGION THIS MORNING. CLOUDS ARE EXPECTED TO THIN OUT THROUGH THE DAY. VERY HIGH PRESSURE WILL CONTINUE TO SETTLE ACROSS THE AREA TODAY. HIGH TEMPERATURES TODAY WILL ONLY RISE INTO THE LOW TEENS. TONIGHT THE RAP IS FORECASTING A 1042 MB HIGH ACROSS SOUTHWEST NORTH DAKOTA. THIS IS RATHER ANOMALOUS ANYTIME DURING WINTER...BUT ESPECIALLY THIS EARLY. THIS VERY COLD HIGH PRESSURE CENTER WILL AID IN TEMPERATURES FALLING INTO THE TEENS BELOW ZERO ACROSS THE SOUTHWEST. COMBINE A LIGHT WIND WITH THESE TEMPERATURES AND YOU HAVE WIND CHILL READINGS IN THE 20S BELOW ZERO. THIS WILL LIKELY WARRANT A WIND CHILL HEADLINE. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 314 AM CST THU NOV 13 2014 CONTINUED COLD THROUGH THE PERIOD AND BLOWING SNOW POTENTIAL SUNDAY HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES TO DEPICT A BLOCKING HIGH AMPLITUDE UPPER LEVEL RIDGE ACROSS THE EASTERN PACIFIC AND AN ANOMALOUSLY DEEP LONG WAVE TROUGH ACROSS THE CENTRAL AND EASTERN CONUS REMAINING THROUGH THE EXTENDED. THIS PATTERNS PROPAGATES VERY SLOWLY EAST THROUGH THE PERIOD...WHICH MAY ALLOW FOR A RELATIVE WARM UP INTO STILL BELOW NORMAL HIGHS IN THE 20S BY MID NEXT WEEK. PRIOR TO THIS...HIGHS GENERALLY IN THE TEENS ARE EXPECTED WITH WIND CHILLS EACH NIGHT AND EARLY MORNING APPROACHING BUT STAYING JUST WARMER THAN ADVISORY CRITERIA OF -25. THE 00 UTC SUITE IS ALSO IN AGREEMENT ON A CLIPPER SYSTEM TO IMPACT THE NORTHERN PLAINS ON SUNDAY. STRONG WINDS BEHIND THE REINFORCING COLD SURGE MAY LEAD TO BLOWING SNOW...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTH CENTRAL WHERE SNOW DEPTHS ARE GREATEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 607 AM CST THU NOV 13 2014 MVFR STRATUS WITH EMBEDDED POCKETS OF BRIEF IFR VISIBILITIES IN LIGHT SNOW WILL IMPACT MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. WHILE THE STRATUS IS EXPECTED TO SLOWLY DECREASE INTO THE AFTERNOON...CONFIDENCE IN THE TIMING OF CLEARING IS LOW. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...AJ LONG TERM...AYD AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
607 AM CST THU NOV 13 2014 .UPDATE... ISSUED AT 607 AM CST THU NOV 13 2014 THE 06 UTC DETERMINISTIC SUITE AND 09-11 UTC RAP/HRRR ITERATIONS ARE HAVING A DIFFICULT TIME RESOLVING THE LOW LEVEL STRATUS FIELD THAT CONTINUES TO SLOWLY EXPAND ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. THE 10 UTC LAMP IS REALLY THE ONLY GUIDANCE PICKING UP ON THE STRATUS. THUS...WILL MAINTAIN THE STRATUS AS OBSERVED THROUGH 12 UTC...SLOWLY ERODING IT THROUGH THE AFTERNOON AS THE SURFACE HIGH AXIS ACROSS EASTERN MONTANA PROPAGATES EAST. HOWEVER...CONFIDENCE IN HOW THE STRATUS WILL EVOLVE IS LOW. ALSO ADDED FLURRIES TO LOCATIONS UNDER THE STRATUS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST THU NOV 13 2014 CLOUDS CONTINUE TO INCREASE ACROSS THE AREA THIS MORNING. THIS IS ALLOWING TEMPERATURES TO MODERATE SOMEWHAT ACROSS THE REGION THIS MORNING. CLOUDS ARE EXPECTED TO THIN OUT THROUGH THE DAY. VERY HIGH PRESSURE WILL CONTINUE TO SETTLE ACROSS THE AREA TODAY. HIGH TEMPERATURES TODAY WILL ONLY RISE INTO THE LOW TEENS. TONIGHT THE RAP IS FORECASTING A 1042 MB HIGH ACROSS SOUTHWEST NORTH DAKOTA. THIS IS RATHER ANOMALOUS ANYTIME DURING WINTER...BUT ESPECIALLY THIS EARLY. THIS VERY COLD HIGH PRESSURE CENTER WILL AID IN TEMPERATURES FALLING INTO THE TEENS BELOW ZERO ACROSS THE SOUTHWEST. COMBINE A LIGHT WIND WITH THESE TEMPERATURES AND YOU HAVE WIND CHILL READINGS IN THE 20S BELOW ZERO. THIS WILL LIKELY WARRANT A WIND CHILL HEADLINE. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 314 AM CST THU NOV 13 2014 CONTINUED COLD THROUGH THE PERIOD AND BLOWING SNOW POTENTIAL SUNDAY HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES TO DEPICT A BLOCKING HIGH AMPLITUDE UPPER LEVEL RIDGE ACROSS THE EASTERN PACIFIC AND AN ANOMALOUSLY DEEP LONG WAVE TROUGH ACROSS THE CENTRAL AND EASTERN CONUS REMAINING THROUGH THE EXTENDED. THIS PATTERNS PROPAGATES VERY SLOWLY EAST THROUGH THE PERIOD...WHICH MAY ALLOW FOR A RELATIVE WARM UP INTO STILL BELOW NORMAL HIGHS IN THE 20S BY MID NEXT WEEK. PRIOR TO THIS...HIGHS GENERALLY IN THE TEENS ARE EXPECTED WITH WIND CHILLS EACH NIGHT AND EARLY MORNING APPROACHING BUT STAYING JUST WARMER THAN ADVISORY CRITERIA OF -25. THE 00 UTC SUITE IS ALSO IN AGREEMENT ON A CLIPPER SYSTEM TO IMPACT THE NORTHERN PLAINS ON SUNDAY. STRONG WINDS BEHIND THE REINFORCING COLD SURGE MAY LEAD TO BLOWING SNOW...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTH CENTRAL WHERE SNOW DEPTHS ARE GREATEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 607 AM CST THU NOV 13 2014 MVFR STRATUS WITH EMBEDDED POCKETS OF BRIEF IFR VISIBILITIES IN LIGHT SNOW WILL IMPACT MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. WHILE THE STRATUS IS EXPECTED TO SLOWLY DECREASE INTO THE AFTERNOON...CONFIDENCE IN THE TIMING OF CLEARING IS LOW. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...AJ LONG TERM...AYD AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
314 AM CST THU NOV 13 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CST THU NOV 13 2014 CLOUDS CONTINUE TO INCREASE ACROSS THE AREA THIS MORNING. THIS IS ALLOWING TEMPERATURES TO MODERATE SOMEWHAT ACROSS THE REGION THIS MORNING. CLOUDS ARE EXPECTED TO THIN OUT THROUGH THE DAY. VERY HIGH PRESSURE WILL CONTINUE TO SETTLE ACROSS THE AREA TODAY. HIGH TEMPERATURES TODAY WILL ONLY RISE INTO THE LOW TEENS. TONIGHT THE RAP IS FORECASTING A 1042 MB HIGH ACROSS SOUTHWEST NORTH DAKOTA. THIS IS RATHER ANOMALOUS ANYTIME DURING WINTER...BUT ESPECIALLY THIS EARLY. THIS VERY COLD HIGH PRESSURE CENTER WILL AID IN TEMPERATURES FALLING INTO THE TEENS BELOW ZERO ACROSS THE SOUTHWEST. COMBINE A LIGHT WIND WITH THESE TEMPERATURES AND YOU HAVE WIND CHILL READINGS IN THE 20S BELOW ZERO. THIS WILL LIKELY WARRANT A WIND CHILL HEADLINE. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 314 AM CST THU NOV 13 2014 CONTINUED COLD THROUGH THE PERIOD AND BLOWING SNOW POTENTIAL SUNDAY HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES TO DEPICT A BLOCKING HIGH AMPLITUDE UPPER LEVEL RIDGE ACROSS THE EASTERN PACIFIC AND AN ANOMALOUSLY DEEP LONG WAVE TROUGH ACROSS THE CENTRAL AND EASTERN CONUS REMAINING THROUGH THE EXTENDED. THIS PATTERNS PROPAGATES VERY SLOWLY EAST THROUGH THE PERIOD...WHICH MAY ALLOW FOR A RELATIVE WARM UP INTO STILL BELOW NORMAL HIGHS IN THE 20S BY MID NEXT WEEK. PRIOR TO THIS...HIGHS GENERALLY IN THE TEENS ARE EXPECTED WITH WIND CHILLS EACH NIGHT AND EARLY MORNING APPROACHING BUT STAYING JUST WARMER THAN ADVISORY CRITERIA OF -25. THE 00 UTC SUITE IS ALSO IN AGREEMENT ON A CLIPPER SYSTEM TO IMPACT THE NORTHERN PLAINS ON SUNDAY. STRONG WINDS BEHIND THE REINFORCING COLD SURGE MAY LEAD TO BLOWING SNOW...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTH CENTRAL WHERE SNOW DEPTHS ARE GREATEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 314 AM CST WED NOV 12 2014 MVFR TO LOW VFR CLOUDS BEGINNING TO DISSIPATE ACROSS ALL TAF SITES. EXPECT THIS TREND TO CONTINUE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT HOURS. MVFR CLOUDS OVER EASTERN MONTANA HAVE MOVED TO KDIK...BUT LATEST RAP/HRRR KEEP THE CLOUDS OUT SO WILL LIKELY ADD A TEMPO GROUP HERE AS CLOUDS GO IN AND OUT. AFTER 12 UTC THURSDAY WE SHOULD SEE AN IMPROVEMENT TO ALL VFR FROM WEST TO EAST AS HIGH PRESSURE OVER MONTANA MOVES EAST INTO THE DAKOTAS. NORTHWEST WINDS WILL CONTINUE TO DIMINISH TONIGHT AND REMAIN AROUND 5-15 KNOTS FROM THE WEST TO NORTHWEST THURSDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AJ LONG TERM...AYD AVIATION...TWH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1233 PM EST THU NOV 13 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR REMAINS ENTRENCHED OVER THE EASTERN TWO THIRDS OF THE UNITED STATES. SPRAWLING SURFACE HIGH PRESSURE WILL PROVIDE DRY WEATHER THROUGH THE END OF THE WORK WEEK AND INTO THE FIRST HALF OF THE WEEKEND. A COUPLE OF WEATHER SYSTEMS SHIFTING THROUGH THE TENNESSEE AND OHIO VALLEYS SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO ON SUNDAY AFTERNOON AND EVENING. THE COLDEST AIR OF THE SEASON IS POISED TO MOVE INTO THE AREA IN THE WAKE OF THESE SYSTEMS EARLY NEXT WEEK...WITH HIGHS REMAINING BELOW FREEZING...AND LOWS IN THE TEENS AND BRISK WINDS. && .NEAR TERM /THROUGH TONIGHT/... AN UPR LVL TROF AXIS WILL CONTINUE TO SHIFT EAST/SOUTHEAST INTO THE GREAT LAKES AND OHIO VALLEY TODAY. WEAK LIFT AND DEEPEST MOISTURE AHEAD OF THIS TROF IS CURRENTLY OVER THE REGION. THERE APPEARS TO BE ENOUGH SEPARATION BETWEEN MID LEVEL CLOUD DECK AND LOWER LEVEL STRATOCUMULUS TO PREVENT A SEED/FEEDER SET UP PER WEAK ECHO RETURNS ON KILN RADAR. THE EXCEPTION IS PERHAPS THE FAR NW. RAP/HRRR MODELS SUGGEST THAT THE DEEPEST MOISTURE WILL SHIFT EAST TODAY. HOWEVER...WITH A WEAK SFC TROF AXIS REFLECTED AT THE SFC...COMBINED WITH CAA OVER LAKE MICHIGAN...A FEW SNOW SHOWERS MAY BE POSSIBLE...ESPECIALLY NORTH. HAVE ADDED ISOLATED SNOW SHOWERS IN THESE LOCATIONS. RADAR AND SATELLITE TRENDS DEPICT FLURRY DEVELOPMENT TO OUR WEST IN THE LOW LEVEL MOIST CAA. AS A RESULT...AM NOW EXPECTING SOME SCATTERED FLURRIES ELSEWHERE AS THIS LOW LEVEL MOISTURE INTERSECTS THE FAVORABLE DENDRITIC GROWTH ZONE...ALLOWING THE MOIST...UNSTABLE LAYER TO SQUEEZE OUT A FEW DENDRITES. HIGHS TODAY WILL RANGE FROM THE UPPER 20S WEST TO THE MID 30S EAST...SOME 20 DEGREES BELOW NORMAL FOR MID NOVEMBER. FOR TONIGHT...HIGHER RES NAM-WRF AND EVEN TO A DEGREE GFS DATA SUGGESTS 900-800MB RH WILL REMAIN HIGH OR EVEN INCREASE TONIGHT AS COLD ADVECTION CONTINUES WITH -14C 850MB POOL ROTATING EAST RIGHT ACROSS THE CWA TONIGHT. DESPITE SUBSIDENCE THAT CONTINUES TO INCREASE...WILL ONLY ALLOW FOR A VERY SLOW EROSION OF CLOUDS AND IT MAY VERY WELL REMAIN MOSTLY CLOUDY THROUGH THE NIGHT AS WELL. FOR THIS REASON...KEEPING MIN TEMPS ON THE WARM SIDE OF STATISTICAL MOS. AT SOME POINT MAY NEED TO MENTION A FLURRY OR LIGHT SNOW SHOWER REMAINING INTACT ALL THE WAY FROM LAKE MICHIGAN INTO AREAS NORTH OF I-70 /REF VERY WEAK SIMULATE REFLECTIVITY ON RECENT HR RR RUNS INTO AUGLAIZE/HARDIN COUNTIES/ && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THIS A QUIET...COLD PERIOD. POOL OF -14C /850MB/ AIR ONLY VERY SLOWLY MODIFIES ON FRIDAY...WITH VERY SIMILAR 925MB TEMPS AS ON THURSDAY...SO KEEPING HIGH TEMPS VERY SIMILAR TO FRIDAY WITH EMPHASIS ON RELATIVELY HIGHER TERRAIN AREAS THE COOLEST AND WARMEST OVER IN THE SCIOTO VALLEY. AM BANKING ON MORE SUNSHINE ON FRIDAY ESPECIALLY THE FURTHER SOUTH ONE GOES IN THE ILN FORECAST AREA...GIVEN TRAJECTORIES OF LOW LEVEL FLOW OFF LAKE MICHIGAN FOCUSING THE BETTER STREAMERS OF LAKE EFFECT CLOUDS INTO AREA ALONG/NORTH OF I-70. THAT BEING SAID...PESKY SUBSIDENCE INVERSION REMAINS ON 13.00Z NAM/GFS SOUNDINGS INTO FRIDAY AFTERNOON WITH STRONG DEEP TROPOSPHERIC SUBSIDENCE SIGNAL ALOFT. PLENTY OF RH ON FCST SOUNDINGS...BUT NOT AS MUCH AS THURSDAY...SO THINKING AT LEAST PARTLY CLOUDY SHOULD WORK BY AFTERNOON MOST AREAS. WE ALWAYS SEEM TO UNDERESTIMATE HOW LONG THE LOW CLOUDS HANG IN THESE FLOW REGIMES...SO LOWER CONFIDENCE HERE. AS MENTIONED IN PREVIOUS DISCUSSIONS...A CHANCE WE COULD TIE OR BARELY BREAK A RECORD LOW MAXIMUM TEMP RECORD ON FRIDAY...ONLY BECAUSE FRIDAY/S VALUES ARE A NOTICEABLE BUBBLE OF WARMTH IN THE PERIOD OF RECORD IN COMPARISON WITH DAYS AROUND IT. CMH /34 DEGREES IN 1916/ HAS THE GREATEST POTENTIAL FOLLOWED BY 32 DEGREES /CVG IN 1916/ AND DAYTON /31 DEGREES IN 1916/. IF A GOOD CLEARING TREND DOES OCCUR FRIDAY NIGHT...APPROACH AND PASSAGE OF 1032MB SURFACE HIGH ACROSS SRN OH AND KENTUCKY SHOULD MEAN LIGHT WINDS OVERNIGHT AND POTENTIAL FOR GOOD TEMP DROP. CONTINUE TO MENTION MID/UPPER TEENS MOST AREAS WITH A BIAS CORRECTION INFLUENCE ON THE TEMP GRID TO BRING OUT THE RELATIVE WARM/COOL SPOTS. WOULD NOT BE AT ALL SURPRISED TO SEE SOME OF THE REAL NOOKS AND CRANNIES PRONE TO COLD AIR SEEPAGE DROP DOWN IN THE LOWER TEENS IF SKIES GO CLEAR EARLY IN THE NIGHT. QUIET WEATHER CONTINUES INTO SATURDAY. SYSTEMS WE WILL NEED TO START WATCHING FOR LATER IN THE WEEKEND /SEE MORE IN LONG TERM DISCUSSION BELOW/ WILL BE 1) DIGGING SOUTHWARD THROUGH NRN ROCKIES...DOWN THE BACKSIDE OF ANOMALOUS WRN CANADA ANTICYCLONE...AND 2) WEAKER WAVE OVER THE FOUR CORNERS. FLOW OVER THE OHIO VALLEY WILL BE BACKING AND FLATTENING IN THE BASAL PORTION OF THE MASSIVE LONG WAVE TROUGH...AND DESPITE SOME RATHER DECENT MID LEVEL HEIGHT RISES DURING THE DAY ON SATURDAY...LOW LEVEL TEMPS WILL BE SLOWER TO RESPOND. DUE TO WEAK TRAJECTORIES/POOR MIXING ON BACKSIDE OF STRONG SURFACE HIGH PUSHING SOUTHEAST OF AREA. LIKELY TO BE AN INCREASE IN CIRRUS SAT AFTN AND WHATEVER REMNANT LOW CLOUDS MAY STILL BE HANGING AROUND...BUT THIS DAY PROBABLY HAS THE POTENTIAL OF A GOOD AMOUNT OF SUNSHINE...WHICH WILL ALLOW TEMPS BACK INTO THE MID/UPPER 30S. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... WEAK WAVE OVER THE FOUR CORNERS SATURDAY MORNING WILL BE EJECTED QUICKLY ON FAST LY FLOW THROUGH THE BASE OF L/W TROUGH INTO THE OHIO VALLEY SAT NIGHT. MOISTURE STARVED...WEAK VERTICAL MOTION SUGGESTS A CONTINUED LOW/MID RANGE MENTION OF LIGHT SNOW CHANCES LATER SATURDAY NIGHT. HAVE SLOWED DOWN THE MENTION OF SNOW A LITTLE FROM PREVIOUS FORECAST. INCREASING/THICKENING CLOUDS SAT NIGHT SHOULD KEEP LOWS A GOOD DEAL WARMER ON SAT NIGHT IN COMPARISON TO FRI NIGHT. WAVE OF INTEREST THOUGH WILL ITSELF BE DIGGING THROUGH THE FOUR CORNERS BY SUNDAY MORNING SET TO EJECT QUICKLY EAST...THOUGH AT A LOWER LATITUDE WITH IT BEING STRONGER AND A DEEPER DIG THROUGH THE L/W TROUGH. THIS WAVE WILL BEGIN TO PHASE WITH AN EVEN STRONGER SHORTWAVE DIGGING SOUTHEAST THROUGH THE WESTERN GREAT LAKES ON SUNDAY AFTERNOON...WHICH IN AN OVERALL SENSE GREATLY AMPLIFIES/SHARPENS THE LONGWAVE TROUGH. WEIGHTED GFS PROGS FOR SUNDAY/MONDAY HAVE SHOWN A STRONG AMPLIFICATION SIGNAL IN RUN- 0VER-RUN SENSE WITH THIS DEEPENING UPPER TROUGH WITH LOWERING HEIGHTS IN THE BASE OF THE TROUGH AND INCREASING HEIGHTS W/TIME ON BOTH UPSTREAM AND DOWNSTREAM RIDGES. IN RESPONSE...PRESSURES WILL FALL WELL DOWNSTREAM OF THIS PHASING OVER THE GULF COAST INTO THE APPALACHIANS SUNDAY AFTN/NIGHT WITH MOISTURE ADVECTION IN THE MID LEVELS TAKING PLACE AND INCREASING DEFORMATION/FGEN FORCING ON THE WEST SIDE OF THE APPALACHIANS INCLUDING OHIO/IND/KY. THIS SHOULD PROMOTE A NEWRD TRANSLATING BAND OF PCPN THROUGH KENTUCKY INTO OHIO/WV SUNDAY AND SUNDAY NIGHT. DPROG/DT TRENDS STILL JUMPY OVER THE LAST 24 HOURS...BUT SOME CONSENSUS STARTING TO BE SEEN WITH 12.12Z GFS AND 13.00Z GFS LOOKING SIMILAR...WHICH IS A TREND TO 12.00Z AND 12.12Z ECMWF SHOWING PRECIPITATION FOCUSING IN ERN HALF OF CWA WITH POTENTIAL FOR LIGHT ACCUMULATING SNOWS. DETERMINISTIC GFS /PARALLEL AND OPNL/ CONTINUE TO BE COLDER THAN ECMWF WITH ALL SNOW SCENARIO...WHILE RECENT ECMWF RUNS VERY STABLE IN SUGGESTING PERHAPS A RAIN/SNOW POTENTIAL IN OUR FAR SOUTHERN/EASTERN AREAS. INCREASED PCPN CHANCES BRINGING LIKELY CHANCES BACK TO CVG/ILN/CMH AND BLENDED THERMAL PROFILES OF COLDER GFS/WARMER ECMWF TO ARRIVE AT PTYPE. 12.18Z GEFS PROBS SUPPORT THE LIKELY POPS IN OUR SOUTH/EAST AT THIS TIME RANGE...AND THERE IS ACKNOWLEDGMENT THAT IF NEW 12Z DETERMINISTIC ECMWF/GFS CONTINUE TO STABILIZE THAT HIGHER CHANCES OF PCPN WILL BE NEEDED CWA-WIDE THOUGH THERE IS A TIGHT GRADIENT IN OUR WEST AS OF NOW. POTENTIAL FOR LIGHT SNOW ACCUMULATIONS FOR MANY ON SUN/SUN NIGHT. MOST CONSENSUS FOCUS RIGHT NOW IS EAST OF I-71. SYSTEM PUSHES EAST MONDAY WITH CORE OF COLDEST AIR IN THIS PATTERN DROPPING SOUTH AND THEN EAST RIGHT ACROSS THE CWA MON NIGHT AND TUES. 850MB TEMPS TO -18C SEEMS LIKELY...WHICH PUTS US AT VERY EDGE OF THE ENVELOPE IN TERMS OF THE CLIMO SPECTRUM SEEN IN BOTH GEFS AND NAEFS REFORECAST PERCENTILES...MEANING FOR WHAT IS BEING FORECAST BY THE ENSEMBLE SYSTEMS AT THIS TIME RANGE IS UNUSUAL TO BE THIS DEEP/COLD WITH THE UPPER TROUGH. M-CLIMATE NUMBERS /GEFS/ AND REFORECAST PERCENTILES /NAEFS/ ARE EITHER AT THEIR MINS OR VERY NEAR THE MIN. AUTUMN READING OF -18C AT 850 MB AT ILN/DAY HAS ONLY HAPPENED ONCE IN THE SOUNDING DATA CLIMATOLOGY ON OR BEFORE NOVEMBER 19TH HAS ONLY HAPPENED ONE TIME /12Z ON NOVEMBER 13 1986 -- -19.3C/. WITH 500MB HEIGHTS/850MB TEMPS BOTH APPROACHING BUT JUST FALLING SHY OF 3 SIGMA BELOW CLIMO...WE PROBABLY SHOULD CONSIDER THE POTENTIAL FOR RECORD TYING/BREAKING TEMPS IN ONE OR MORE OF THESE PERIODS. FOR RIGHT NOW GIVEN WE/RE STILL 5 DAYS AWAY...WILL FOCUS ON TUESDAY MAX TEMPS GIVEN THIS IS WHEN CORE OF COLDEST AIR PASSES OVERHEAD IN BASE OF THERMAL TROUGH. SO PUT TUES MAX TEMPS RIGHT AT RECORD LOW MAX VALUES FOR RIGHT NOW AND WE CAN EVALUATE FURTHER DROPS IF NEEDED. LOW CLOUDS IN LEE OF WARM GREAT LAKES MAY KEEP RECORD MINS UNATTAINABLE AND PLAYING IT THIS WAY RIGHT NOW AS RECORD LOWS ARE VERY COLD ON NOV 19TH. SOMETHING TO WATCH...EITHER WAY...VERY CHILLY FOR MID NOV BUT OUTSIDE OF FLURRY OR PERHAPS A SNOW SHOWER THREAT...MON/TUES SHOULD BE DRY. STILL LOOKS LIKE THIS STRETCH WILL END UP VERY SIMILAR TO NOVEMBER STRETCHES IN 1991...1996...AND 1997. ALL THREE OF THOSE YEARS HAD 8-9 DAY STRETCHES WHERE AVERAGE DAILY TEMPS FOR THE PERIOD WERE NEAR 30F...AND ARE SOME THE CHILLIEST EARLY-MID NOVEMBER LONGER DURATION PERIODS ON RECORD. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... A MID LEVEL TROUGH WILL PUSH EAST/SOUTHEAST THROUGH THE GREAT LAKES AND OHIO VALLEY THROUGH TONIGHT. FOR THIS AFTERNOON INTO EARLY THIS EVENING...MOISTURE BETWEEN 900 MB-850 MB IS A LITTLE UNSTABLE AND ALSO INTERSECTING THE FAVORABLE SNOW GROWTH ZONE. AS A RESULT...SOME SCATTERED FLURRIES CAN BE EXPECTED. THESE FLURRIES SHOULD DIMINISH BY THIS EVENING AS THE ATMOSPHERE STABILIZES SOME DUE TO SURFACE COOLING. THERE WILL ALSO BE SOME POCKETS OF MVFR CEILINGS...MAINLY ACROSS THE NORTHERN TAF SITES. FOR LATER TONIGHT...SCATTERED TO BROKEN STRATOCUMULUS WILL LINGER AS 850 MB COLD POOL SETTLES INTO THE REGION. CEILINGS SHOULD REMAIN VFR. ON FRIDAY...MID LEVEL TROUGH MOVE EAST AS SURFACE HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST. WILL CONTINUE TO SEE SCATTERED TO BROKEN STRATOCUMULUS THROUGH THE DAY UNTIL THE 850 MB COOL POOL/MOISTURE MOVE OFF DURING FRIDAY NIGHT AS SKIES CLEAR. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SATURDAY NIGHT INTO MONDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU/HICKMAN SHORT TERM...BINAU LONG TERM...BINAU AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1136 AM EST THU NOV 13 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR REMAINS ENTRENCHED OVER THE EASTERN TWO THIRDS OF THE UNITED STATES. SPRAWLING SURFACE HIGH PRESSURE WILL PROVIDE DRY WEATHER THROUGH THE END OF THE WORK WEEK AND INTO THE FIRST HALF OF THE WEEKEND. A COUPLE OF WEATHER SYSTEMS SHIFTING THROUGH THE TENNESSEE AND OHIO VALLEYS SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO ON SUNDAY AFTERNOON AND EVENING. THE COLDEST AIR OF THE SEASON IS POISED TO MOVE INTO THE AREA IN THE WAKE OF THESE SYSTEMS EARLY NEXT WEEK...WITH HIGHS REMAINING BELOW FREEZING...AND LOWS IN THE TEENS AND BRISK WINDS. && .NEAR TERM /THROUGH TONIGHT/... AN UPR LVL TROF AXIS WILL CONTINUE TO SHIFT EAST/SOUTHEAST INTO THE GREAT LAKES AND OHIO VALLEY TODAY. WEAK LIFT AND DEEPEST MOISTURE AHEAD OF THIS TROF IS CURRENTLY OVER THE REGION. THERE APPEARS TO BE ENOUGH SEPARATION BETWEEN MID LEVEL CLOUD DECK AND LOWER LEVEL STRATOCUMULUS TO PREVENT A SEED/FEEDER SET UP PER WEAK ECHO RETURNS ON KILN RADAR. THE EXCEPTION IS PERHAPS THE FAR NW. RAP/HRRR MODELS SUGGEST THAT THE DEEPEST MOISTURE WILL SHIFT EAST TODAY. HOWEVER...WITH A WEAK SFC TROF AXIS REFLECTED AT THE SFC...COMBINED WITH CAA OVER LAKE MICHIGAN...A FEW SNOW SHOWERS MAY BE POSSIBLE...ESPECIALLY NORTH. HAVE ADDED ISOLATED SNOW SHOWERS IN THESE LOCATIONS. RADAR AND SATELLITE TRENDS DEPICT FLURRY DEVELOPMENT TO OUR WEST IN THE LOW LEVEL MOIST CAA. AS A RESULT...AM NOW EXPECTING SOME SCATTERED FLURRIES ELSEWHERE AS THIS LOW LEVEL MOISTURE INTERSECTS THE FAVORABLE DENDRITIC GROWTH ZONE...ALLOWING THE MOIST...UNSTABLE LAYER TO SQUEEZE OUT A FEW DENDRITES. HIGHS TODAY WILL RANGE FROM THE UPPER 20S WEST TO THE MID 30S EAST...SOME 20 DEGREES BELOW NORMAL FOR MID NOVEMBER. FOR TONIGHT...HIGHER RES NAM-WRF AND EVEN TO A DEGREE GFS DATA SUGGESTS 900-800MB RH WILL REMAIN HIGH OR EVEN INCREASE TONIGHT AS COLD ADVECTION CONTINUES WITH -14C 850MB POOL ROTATING EAST RIGHT ACROSS THE CWA TONIGHT. DESPITE SUBSIDENCE THAT CONTINUES TO INCREASE...WILL ONLY ALLOW FOR A VERY SLOW EROSION OF CLOUDS AND IT MAY VERY WELL REMAIN MOSTLY CLOUDY THROUGH THE NIGHT AS WELL. FOR THIS REASON...KEEPING MIN TEMPS ON THE WARM SIDE OF STATISTICAL MOS. AT SOME POINT MAY NEED TO MENTION A FLURRY OR LIGHT SNOW SHOWER REMAINING INTACT ALL THE WAY FROM LAKE MICHIGAN INTO AREAS NORTH OF I-70 /REF VERY WEAK SIMULATE REFLECTIVITY ON RECENT HR RR RUNS INTO AUGLAIZE/HARDIN COUNTIES/ && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THIS A QUIET...COLD PERIOD. POOL OF -14C /850MB/ AIR ONLY VERY SLOWLY MODIFIES ON FRIDAY...WITH VERY SIMILAR 925MB TEMPS AS ON THURSDAY...SO KEEPING HIGH TEMPS VERY SIMILAR TO FRIDAY WITH EMPHASIS ON RELATIVELY HIGHER TERRAIN AREAS THE COOLEST AND WARMEST OVER IN THE SCIOTO VALLEY. AM BANKING ON MORE SUNSHINE ON FRIDAY ESPECIALLY THE FURTHER SOUTH ONE GOES IN THE ILN FORECAST AREA...GIVEN TRAJECTORIES OF LOW LEVEL FLOW OFF LAKE MICHIGAN FOCUSING THE BETTER STREAMERS OF LAKE EFFECT CLOUDS INTO AREA ALONG/NORTH OF I-70. THAT BEING SAID...PESKY SUBSIDENCE INVERSION REMAINS ON 13.00Z NAM/GFS SOUNDINGS INTO FRIDAY AFTERNOON WITH STRONG DEEP TROPOSPHERIC SUBSIDENCE SIGNAL ALOFT. PLENTY OF RH ON FCST SOUNDINGS...BUT NOT AS MUCH AS THURSDAY...SO THINKING AT LEAST PARTLY CLOUDY SHOULD WORK BY AFTERNOON MOST AREAS. WE ALWAYS SEEM TO UNDERESTIMATE HOW LONG THE LOW CLOUDS HANG IN THESE FLOW REGIMES...SO LOWER CONFIDENCE HERE. AS MENTIONED IN PREVIOUS DISCUSSIONS...A CHANCE WE COULD TIE OR BARELY BREAK A RECORD LOW MAXIMUM TEMP RECORD ON FRIDAY...ONLY BECAUSE FRIDAY/S VALUES ARE A NOTICEABLE BUBBLE OF WARMTH IN THE PERIOD OF RECORD IN COMPARISON WITH DAYS AROUND IT. CMH /34 DEGREES IN 1916/ HAS THE GREATEST POTENTIAL FOLLOWED BY 32 DEGREES /CVG IN 1916/ AND DAYTON /31 DEGREES IN 1916/. IF A GOOD CLEARING TREND DOES OCCUR FRIDAY NIGHT...APPROACH AND PASSAGE OF 1032MB SURFACE HIGH ACROSS SRN OH AND KENTUCKY SHOULD MEAN LIGHT WINDS OVERNIGHT AND POTENTIAL FOR GOOD TEMP DROP. CONTINUE TO MENTION MID/UPPER TEENS MOST AREAS WITH A BIAS CORRECTION INFLUENCE ON THE TEMP GRID TO BRING OUT THE RELATIVE WARM/COOL SPOTS. WOULD NOT BE AT ALL SURPRISED TO SEE SOME OF THE REAL NOOKS AND CRANNIES PRONE TO COLD AIR SEEPAGE DROP DOWN IN THE LOWER TEENS IF SKIES GO CLEAR EARLY IN THE NIGHT. QUIET WEATHER CONTINUES INTO SATURDAY. SYSTEMS WE WILL NEED TO START WATCHING FOR LATER IN THE WEEKEND /SEE MORE IN LONG TERM DISCUSSION BELOW/ WILL BE 1) DIGGING SOUTHWARD THROUGH NRN ROCKIES...DOWN THE BACKSIDE OF ANOMALOUS WRN CANADA ANTICYCLONE...AND 2) WEAKER WAVE OVER THE FOUR CORNERS. FLOW OVER THE OHIO VALLEY WILL BE BACKING AND FLATTENING IN THE BASAL PORTION OF THE MASSIVE LONG WAVE TROUGH...AND DESPITE SOME RATHER DECENT MID LEVEL HEIGHT RISES DURING THE DAY ON SATURDAY...LOW LEVEL TEMPS WILL BE SLOWER TO RESPOND. DUE TO WEAK TRAJECTORIES/POOR MIXING ON BACKSIDE OF STRONG SURFACE HIGH PUSHING SOUTHEAST OF AREA. LIKELY TO BE AN INCREASE IN CIRRUS SAT AFTN AND WHATEVER REMNANT LOW CLOUDS MAY STILL BE HANGING AROUND...BUT THIS DAY PROBABLY HAS THE POTENTIAL OF A GOOD AMOUNT OF SUNSHINE...WHICH WILL ALLOW TEMPS BACK INTO THE MID/UPPER 30S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... WEAK WAVE OVER THE FOUR CORNERS SATURDAY MORNING WILL BE EJECTED QUICKLY ON FAST LY FLOW THROUGH THE BASE OF L/W TROUGH INTO THE OHIO VALLEY SAT NIGHT. MOISTURE STARVED...WEAK VERTICAL MOTION SUGGESTS A CONTINUED LOW/MID RANGE MENTION OF LIGHT SNOW CHANCES LATER SATURDAY NIGHT. HAVE SLOWED DOWN THE MENTION OF SNOW A LITTLE FROM PREVIOUS FORECAST. INCREASING/THICKENING CLOUDS SAT NIGHT SHOULD KEEP LOWS A GOOD DEAL WARMER ON SAT NIGHT IN COMPARISON TO FRI NIGHT. WAVE OF INTEREST THOUGH WILL ITSELF BE DIGGING THROUGH THE FOUR CORNERS BY SUNDAY MORNING SET TO EJECT QUICKLY EAST...THOUGH AT A LOWER LATITUDE WITH IT BEING STRONGER AND A DEEPER DIG THROUGH THE L/W TROUGH. THIS WAVE WILL BEGIN TO PHASE WITH AN EVEN STRONGER SHORTWAVE DIGGING SOUTHEAST THROUGH THE WESTERN GREAT LAKES ON SUNDAY AFTERNOON...WHICH IN AN OVERALL SENSE GREATLY AMPLIFIES/SHARPENS THE LONGWAVE TROUGH. WEIGHTED GFS PROGS FOR SUNDAY/MONDAY HAVE SHOWN A STRONG AMPLIFICATION SIGNAL IN RUN- 0VER-RUN SENSE WITH THIS DEEPENING UPPER TROUGH WITH LOWERING HEIGHTS IN THE BASE OF THE TROUGH AND INCREASING HEIGHTS W/TIME ON BOTH UPSTREAM AND DOWNSTREAM RIDGES. IN RESPONSE...PRESSURES WILL FALL WELL DOWNSTREAM OF THIS PHASING OVER THE GULF COAST INTO THE APPALACHIANS SUNDAY AFTN/NIGHT WITH MOISTURE ADVECTION IN THE MID LEVELS TAKING PLACE AND INCREASING DEFORMATION/FGEN FORCING ON THE WEST SIDE OF THE APPALACHIANS INCLUDING OHIO/IND/KY. THIS SHOULD PROMOTE A NEWRD TRANSLATING BAND OF PCPN THROUGH KENTUCKY INTO OHIO/WV SUNDAY AND SUNDAY NIGHT. DPROG/DT TRENDS STILL JUMPY OVER THE LAST 24 HOURS...BUT SOME CONSENSUS STARTING TO BE SEEN WITH 12.12Z GFS AND 13.00Z GFS LOOKING SIMILAR...WHICH IS A TREND TO 12.00Z AND 12.12Z ECMWF SHOWING PRECIPITATION FOCUSING IN ERN HALF OF CWA WITH POTENTIAL FOR LIGHT ACCUMULATING SNOWS. DETERMINISTIC GFS /PARALLEL AND OPNL/ CONTINUE TO BE COLDER THAN ECMWF WITH ALL SNOW SCENARIO...WHILE RECENT ECMWF RUNS VERY STABLE IN SUGGESTING PERHAPS A RAIN/SNOW POTENTIAL IN OUR FAR SOUTHERN/EASTERN AREAS. INCREASED PCPN CHANCES BRINGING LIKELY CHANCES BACK TO CVG/ILN/CMH AND BLENDED THERMAL PROFILES OF COLDER GFS/WARMER ECMWF TO ARRIVE AT PTYPE. 12.18Z GEFS PROBS SUPPORT THE LIKELY POPS IN OUR SOUTH/EAST AT THIS TIME RANGE...AND THERE IS ACKNOWLEDGMENT THAT IF NEW 12Z DETERMINISTIC ECMWF/GFS CONTINUE TO STABILIZE THAT HIGHER CHANCES OF PCPN WILL BE NEEDED CWA-WIDE THOUGH THERE IS A TIGHT GRADIENT IN OUR WEST AS OF NOW. POTENTIAL FOR LIGHT SNOW ACCUMULATIONS FOR MANY ON SUN/SUN NIGHT. MOST CONSENSUS FOCUS RIGHT NOW IS EAST OF I-71. SYSTEM PUSHES EAST MONDAY WITH CORE OF COLDEST AIR IN THIS PATTERN DROPPING SOUTH AND THEN EAST RIGHT ACROSS THE CWA MON NIGHT AND TUES. 850MB TEMPS TO -18C SEEMS LIKELY...WHICH PUTS US AT VERY EDGE OF THE ENVELOPE IN TERMS OF THE CLIMO SPECTRUM SEEN IN BOTH GEFS AND NAEFS REFORECAST PERCENTILES...MEANING FOR WHAT IS BEING FORECAST BY THE ENSEMBLE SYSTEMS AT THIS TIME RANGE IS UNUSUAL TO BE THIS DEEP/COLD WITH THE UPPER TROUGH. M-CLIMATE NUMBERS /GEFS/ AND REFORECAST PERCENTILES /NAEFS/ ARE EITHER AT THEIR MINS OR VERY NEAR THE MIN. AUTUMN READING OF -18C AT 850 MB AT ILN/DAY HAS ONLY HAPPENED ONCE IN THE SOUNDING DATA CLIMATOLOGY ON OR BEFORE NOVEMBER 19TH HAS ONLY HAPPENED ONE TIME /12Z ON NOVEMBER 13 1986 -- -19.3C/. WITH 500MB HEIGHTS/850MB TEMPS BOTH APPROACHING BUT JUST FALLING SHY OF 3 SIGMA BELOW CLIMO...WE PROBABLY SHOULD CONSIDER THE POTENTIAL FOR RECORD TYING/BREAKING TEMPS IN ONE OR MORE OF THESE PERIODS. FOR RIGHT NOW GIVEN WE/RE STILL 5 DAYS AWAY...WILL FOCUS ON TUESDAY MAX TEMPS GIVEN THIS IS WHEN CORE OF COLDEST AIR PASSES OVERHEAD IN BASE OF THERMAL TROUGH. SO PUT TUES MAX TEMPS RIGHT AT RECORD LOW MAX VALUES FOR RIGHT NOW AND WE CAN EVALUATE FURTHER DROPS IF NEEDED. LOW CLOUDS IN LEE OF WARM GREAT LAKES MAY KEEP RECORD MINS UNATTAINABLE AND PLAYING IT THIS WAY RIGHT NOW AS RECORD LOWS ARE VERY COLD ON NOV 19TH. SOMETHING TO WATCH...EITHER WAY...VERY CHILLY FOR MID NOV BUT OUTSIDE OF FLURRY OR PERHAPS A SNOW SHOWER THREAT...MON/TUES SHOULD BE DRY. STILL LOOKS LIKE THIS STRETCH WILL END UP VERY SIMILAR TO NOVEMBER STRETCHES IN 1991...1996...AND 1997. ALL THREE OF THOSE YEARS HAD 8-9 DAY STRETCHES WHERE AVERAGE DAILY TEMPS FOR THE PERIOD WERE NEAR 30F...AND ARE SOME THE CHILLIEST EARLY-MID NOVEMBER LONGER DURATION PERIODS ON RECORD. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... MVFR/LOW VFR STRATOCUMULUS DECK IS TRYING TO ERODE AWAY FROM THE WEST WITH SOME LOW LEVEL CLEARING WORKING ACROSS MUCH OF CENTRAL INDIANA. LOWER CLOUDS ARE A LITTLE DIFFICULT TO MAKE OUT ON SATELLITE GIVEN SOME OF THE MID LEVEL CLOUDS ALSO MOVING ACROSS THE AREA...BUT IT DOES LOOK LIKE THE EASTWARD PROGRESSION OF THE LOWER CLOUD CLEARING MAY HAVE SLOWED DOWN ON THE LAST COUPLE OF IMAGES. MODELS ARE SUGGESTING A BIT OF A LOW LEVEL DRY WEDGE POSSIBLY WORKING ACROSS THE AREA THROUGH LATE MORNING...BUT AM HESITANT TO BACK AWAY FROM THE MVFR CIGS BASED ON THEIR PERSISTENCE SO FAR. WILL GO AHEAD AND ALLOW THE CIGS TO LIFT UP INTO VFR THIS AFTERNOON BUT CONTINUE TO LEAN PESSIMISTIC AND HANG ON TO AT LEAST A BKN VFR CLOUD DECK THROUGH TONIGHT. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SUNDAY INTO MONDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU/HICKMAN SHORT TERM...BINAU LONG TERM...BINAU AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
942 AM EST THU NOV 13 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR REMAINS ENTRENCHED OVER THE EASTERN TWO THIRDS OF THE UNITED STATES. SPRAWLING SURFACE HIGH PRESSURE WILL PROVIDE DRY WEATHER THROUGH THE END OF THE WORK WEEK AND INTO THE FIRST HALF OF THE WEEKEND. A COUPLE OF WEATHER SYSTEMS SHIFTING THROUGH THE TENNESSEE AND OHIO VALLEYS SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO ON SUNDAY AFTERNOON AND EVENING. THE COLDEST AIR OF THE SEASON IS POISED TO MOVE INTO THE AREA IN THE WAKE OF THESE SYSTEMS EARLY NEXT WEEK...WITH HIGHS REMAINING BELOW FREEZING...AND LOWS IN THE TEENS AND BRISK WINDS. && .NEAR TERM /THROUGH TONIGHT/... AN UPR LVL TROF AXIS WILL CONTINUE TO SHIFT EAST/SOUTHEAST INTO THE GREAT LAKES AND OHIO VALLEY TODAY. WEAK LIFT AND DEEPEST MOISTURE AHEAD OF THIS TROF IS CURRENTLY OVER THE REGION. THERE APPEARS TO BE ENOUGH SEPARATION BETWEEN MID LEVEL CLOUD DECK AND LOWER LEVEL STRATOCUMULUS TO PREVENT A SEED/FEEDER SET UP PER WEAK ECHO RETURNS ON KILN RADAR. THE EXCEPTION IS PERHAPS THE FAR NW. RAP/HRRR MODELS SUGGEST THAT THE DEEPEST MOISTURE WILL SHIFT EAST TODAY. HOWEVER...WITH A WEAK SFC TROF AXIS REFLECTED AT THE SFC...COMBINED WITH CAA OVER LAKE MICHIGAN...A FEW SNOW SHOWERS MAY BE POSSIBLE...ESPECIALLY NORTH. HAVE ADDED SLIGHT CHANCES OF SNOW SHOWERS IN THESE LOCATIONS. WILL MONITOR RADAR TRENDS TO SEE IF THIS NEEDS TO BE PULLED FARTHER SOUTH. IN ADDITION...THERE MAY BE THE POSSIBILITY OF A FEW FLURRIES ELSEWHERE AS LOW LEVEL MOISTURE INTERSECTS THE FAVORABLE DENDRITIC GROWTH ZONE IN WHICH THE SHALLOW UNSTABLE MOIST LAYER MAY SQUEEZE OUT A FEW FLURRIES. HIGHS TODAY WILL RANGE FROM THE LOWER 30S EAST TO THE MID 30S WEST...SOME 20 DEGREES BELOW NORMAL FOR MID NOVEMBER. FOR TONIGHT...HIGHER RES NAM-WRF AND EVEN TO A DEGREE GFS DATA SUGGESTS 900-800MB RH WILL REMAIN HIGH OR EVEN INCREASE TONIGHT AS COLD ADVECTION CONTINUES WITH -14C 850MB POOL ROTATING EAST RIGHT ACROSS THE CWA TONIGHT. DESPITE SUBSIDENCE THAT CONTINUES TO INCREASE...WILL ONLY ALLOW FOR A VERY SLOW EROSION OF CLOUDS AND IT MAY VERY WELL REMAIN MOSTLY CLOUDY THROUGH THE NIGHT AS WELL. FOR THIS REASON...KEEPING MIN TEMPS ON THE WARM SIDE OF STATISTICAL MOS. AT SOME POINT MAY NEED TO MENTION A FLURRY OR LIGHT SNOW SHOWER REMAINING INTACT ALL THE WAY FROM LAKE MICHIGAN INTO AREAS NORTH OF I-70 /REF VERY WEAK SIMULATE REFLECTIVITY ON RECENT HRRR RUNS INTO AUGLAIZE/HARDIN COUNTIES/ && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THIS A QUIET...COLD PERIOD. POOL OF -14C /850MB/ AIR ONLY VERY SLOWLY MODIFIES ON FRIDAY...WITH VERY SIMILAR 925MB TEMPS AS ON THURSDAY...SO KEEPING HIGH TEMPS VERY SIMILAR TO FRIDAY WITH EMPHASIS ON RELATIVELY HIGHER TERRAIN AREAS THE COOLEST AND WARMEST OVER IN THE SCIOTO VALLEY. AM BANKING ON MORE SUNSHINE ON FRIDAY ESPECIALLY THE FURTHER SOUTH ONE GOES IN THE ILN FORECAST AREA...GIVEN TRAJECTORIES OF LOW LEVEL FLOW OFF LAKE MICHIGAN FOCUSING THE BETTER STREAMERS OF LAKE EFFECT CLOUDS INTO AREA ALONG/NORTH OF I-70. THAT BEING SAID...PESKY SUBSIDENCE INVERSION REMAINS ON 13.00Z NAM/GFS SOUNDINGS INTO FRIDAY AFTERNOON WITH STRONG DEEP TROPOSPHERIC SUBSIDENCE SIGNAL ALOFT. PLENTY OF RH ON FCST SOUNDINGS...BUT NOT AS MUCH AS THURSDAY...SO THINKING AT LEAST PARTLY CLOUDY SHOULD WORK BY AFTERNOON MOST AREAS. WE ALWAYS SEEM TO UNDERESTIMATE HOW LONG THE LOW CLOUDS HANG IN THESE FLOW REGIMES...SO LOWER CONFIDENCE HERE. AS MENTIONED IN PREVIOUS DISCUSSIONS...A CHANCE WE COULD TIE OR BARELY BREAK A RECORD LOW MAXIMUM TEMP RECORD ON FRIDAY...ONLY BECAUSE FRIDAY/S VALUES ARE A NOTICEABLE BUBBLE OF WARMTH IN THE PERIOD OF RECORD IN COMPARISON WITH DAYS AROUND IT. CMH /34 DEGREES IN 1916/ HAS THE GREATEST POTENTIAL FOLLOWED BY 32 DEGREES /CVG IN 1916/ AND DAYTON /31 DEGREES IN 1916/. IF A GOOD CLEARING TREND DOES OCCUR FRIDAY NIGHT...APPROACH AND PASSAGE OF 1032MB SURFACE HIGH ACROSS SRN OH AND KENTUCKY SHOULD MEAN LIGHT WINDS OVERNIGHT AND POTENTIAL FOR GOOD TEMP DROP. CONTINUE TO MENTION MID/UPPER TEENS MOST AREAS WITH A BIAS CORRECTION INFLUENCE ON THE TEMP GRID TO BRING OUT THE RELATIVE WARM/COOL SPOTS. WOULD NOT BE AT ALL SURPRISED TO SEE SOME OF THE REAL NOOKS AND CRANNIES PRONE TO COLD AIR SEEPAGE DROP DOWN IN THE LOWER TEENS IF SKIES GO CLEAR EARLY IN THE NIGHT. QUIET WEATHER CONTINUES INTO SATURDAY. SYSTEMS WE WILL NEED TO START WATCHING FOR LATER IN THE WEEKEND /SEE MORE IN LONG TERM DISCUSSION BELOW/ WILL BE 1) DIGGING SOUTHWARD THROUGH NRN ROCKIES...DOWN THE BACKSIDE OF ANOMALOUS WRN CANADA ANTICYCLONE...AND 2) WEAKER WAVE OVER THE FOUR CORNERS. FLOW OVER THE OHIO VALLEY WILL BE BACKING AND FLATTENING IN THE BASAL PORTION OF THE MASSIVE LONGWAVE TROUGH...AND DESPITE SOME RATHER DECENT MID LEVEL HEIGHT RISES DURING THE DAY ON SATURDAY...LOW LEVEL TEMPS WILL BE SLOWER TO RESPOND. DUE TO WEAK TRAJECTORIES/POOR MIXING ON BACKSIDE OF STRONG SURFACE HIGH PUSHING SOUTHEAST OF AREA. LIKELY TO BE AN INCREASE IN CIRRUS SAT AFTN AND WHATEVER REMNANT LOW CLOUDS MAY STILL BE HANGING AROUND...BUT THIS DAY PROBABLY HAS THE POTENTIAL OF A GOOD AMOUNT OF SUNSHINE...WHICH WILL ALLOW TEMPS BACK INTO THE MID/UPPER 30S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... WEAK WAVE OVER THE FOUR CORNERS SATURDAY MORNING WILL BE EJECTED QUICKLY ON FAST WLY FLOW THROUGH THE BASE OF L/W TROUGH INTO THE OHIO VALLEY SAT NIGHT. MOISTURE STARVED...WEAK VERTICAL MOTION SUGGESTS A CONTINUED LOW/MID RANGE MENTION OF LIGHT SNOW CHANCES LATER SATURDAY NIGHT. HAVE SLOWED DOWN THE MENTION OF SNOW A LITTLE FROM PREVIOUS FORECAST. INCREASING/THICKENING CLOUDS SAT NIGHT SHOULD KEEP LOWS A GOOD DEAL WARMER ON SAT NIGHT IN COMPARISON TO FRI NIGHT. WAVE OF INTEREST THOUGH WILL ITSELF BE DIGGING THROUGH THE FOUR CORNERS BY SUNDAY MORNING SET TO EJECT QUICKLY EAST...THOUGH AT A LOWER LATITUDE WITH IT BEING STRONGER AND A DEEPER DIG THROUGH THE L/W TROUGH. THIS WAVE WILL BEGIN TO PHASE WITH AN EVEN STRONGER SHORTWAVE DIGGING SOUTHEAST THROUGH THE WESTERN GREAT LAKES ON SUNDAY AFTERNOON...WHICH IN AN OVERALL SENSE GREATLY AMPLIFIES/SHARPENS THE LONGWAVE TROUGH. WEIGHTED GFS PROGS FOR SUNDAY/MONDAY HAVE SHOWN A STRONG AMPLIFICATION SIGNAL IN RUN- 0VER-RUN SENSE WITH THIS DEEPENING UPPER TROUGH WITH LOWERING HEIGHTS IN THE BASE OF THE TROUGH AND INCREASING HEIGHTS W/TIME ON BOTH UPSTREAM AND DOWNSTREAM RIDGES. IN RESPONSE...PRESSURES WILL FALL WELL DOWNSTREAM OF THIS PHASING OVER THE GULF COAST INTO THE APPALACHIANS SUNDAY AFTN/NIGHT WITH MOISTURE ADVECTION IN THE MID LEVELS TAKING PLACE AND INCREASING DEFORMATION/FGEN FORCING ON THE WEST SIDE OF THE APPALACHIANS INCLUDING OHIO/IND/KY. THIS SHOULD PROMOTE A NEWRD TRANSLATING BAND OF PCPN THROUGH KENTUCKY INTO OHIO/WV SUNDAY AND SUNDAY NIGHT. DPROG/DT TRENDS STILL JUMPY OVER THE LAST 24 HOURS...BUT SOME CONSENSUS STARTING TO BE SEEN WITH 12.12Z GFS AND 13.00Z GFS LOOKING SIMILAR...WHICH IS A TREND TO 12.00Z AND 12.12Z ECMWF SHOWING PRECIPITATION FOCUSING IN ERN HALF OF CWA WITH POTENTIAL FOR LIGHT ACCUMULATING SNOWS. DETERMINISTIC GFS /PARALLEL AND OPNL/ CONTINUE TO BE COLDER THAN ECMWF WITH ALL SNOW SCENARIO...WHILE RECENT ECMWF RUNS VERY STABLE IN SUGGESTING PERHAPS A RAIN/SNOW POTENTIAL IN OUR FAR SOUTHERN/EASTERN AREAS. INCREASED PCPN CHANCES BRINGING LIKELY CHANCES BACK TO CVG/ILN/CMH AND BLENDED THERMAL PROFILES OF COLDER GFS/WARMER ECMWF TO ARRIVE AT PTYPE. 12.18Z GEFS PROBS SUPPORT THE LIKELY POPS IN OUR SOUTH/EAST AT THIS TIME RANGE...AND THERE IS ACKNOWLEDGMENT THAT IF NEW 12Z DETERMINISTIC ECMWF/GFS CONTINUE TO STABILIZE THAT HIGHER CHANCES OF PCPN WILL BE NEEDED CWA-WIDE THOUGH THERE IS A TIGHT GRADIENT IN OUR WEST AS OF NOW. POTENTIAL FOR LIGHT SNOW ACCUMULATIONS FOR MANY ON SUN/SUN NIGHT. MOST CONSENSUS FOCUS RIGHT NOW IS EAST OF I-71. SYSTEM PUSHES EAST MONDAY WITH CORE OF COLDEST AIR IN THIS PATTERN DROPPING SOUTH AND THEN EAST RIGHT ACROSS THE CWA MON NIGHT AND TUES. 850MB TEMPS TO -18C SEEMS LIKELY...WHICH PUTS US AT VERY EDGE OF THE ENVELOPE IN TERMS OF THE CLIMO SPECTRUM SEEN IN BOTH GEFS AND NAEFS REFORECAST PERCENTILES...MEANING FOR WHAT IS BEING FORECAST BY THE ENSEMBLE SYSTEMS AT THIS TIME RANGE IS UNUSUAL TO BE THIS DEEP/COLD WITH THE UPPER TROUGH. M-CLIMATE NUMBERS /GEFS/ AND REFORECAST PERCENTILES /NAEFS/ ARE EITHER AT THEIR MINS OR VERY NEAR THE MIN. AUTUMN READING OF -18C AT 850 MB AT ILN/DAY HAS ONLY HAPPENED ONCE IN THE SOUNDING DATA CLIMATOLOGY ON OR BEFORE NOVEMBER 19TH HAS ONLY HAPPENED ONE TIME /12Z ON NOVEMBER 13 1986 -- -19.3C/. WITH 500MB HEIGHTS/850MB TEMPS BOTH APPROACHING BUT JUST FALLING SHY OF 3 SIGMA BELOW CLIMO...WE PROBABLY SHOULD CONSIDER THE POTENTIAL FOR RECORD TYING/BREAKING TEMPS IN ONE OR MORE OF THESE PERIODS. FOR RIGHT NOW GIVEN WE/RE STILL 5 DAYS AWAY...WILL FOCUS ON TUESDAY MAX TEMPS GIVEN THIS IS WHEN CORE OF COLDEST AIR PASSES OVERHEAD IN BASE OF THERMAL TROUGH. SO PUT TUES MAX TEMPS RIGHT AT RECORD LOW MAX VALUES FOR RIGHT NOW AND WE CAN EVALUATE FURTHER DROPS IF NEEDED. LOW CLOUDS IN LEE OF WARM GREAT LAKES MAY KEEP RECORD MINS UNATTAINABLE AND PLAYING IT THIS WAY RIGHT NOW AS RECORD LOWS ARE VERY COLD ON NOV 19TH. SOMETHING TO WATCH...EITHER WAY...VERY CHILLY FOR MID NOV BUT OUTSIDE OF FLURRY OR PERHAPS A SNOW SHOWER THREAT...MON/TUES SHOULD BE DRY. STILL LOOKS LIKE THIS STRETCH WILL END UP VERY SIMILAR TO NOVEMBER STRETCHES IN 1991...1996...AND 1997. ALL THREE OF THOSE YEARS HAD 8-9 DAY STRETCHES WHERE AVERAGE DAILY TEMPS FOR THE PERIOD WERE NEAR 30F...AND ARE SOME THE CHILLIEST EARLY-MID NOVEMBER LONGER DURATION PERIODS ON RECORD. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... MVFR/LOW VFR STRATOCUMULUS DECK IS TRYING TO ERODE AWAY FROM THE WEST WITH SOME LOW LEVEL CLEARING WORKING ACROSS MUCH OF CENTRAL INDIANA. LOWER CLOUDS ARE A LITTLE DIFFICULT TO MAKE OUT ON SATELLITE GIVEN SOME OF THE MID LEVEL CLOUDS ALSO MOVING ACROSS THE AREA...BUT IT DOES LOOK LIKE THE EASTWARD PROGRESSION OF THE LOWER CLOUD CLEARING MAY HAVE SLOWED DOWN ON THE LAST COUPLE OF IMAGES. MODELS ARE SUGGESTING A BIT OF A LOW LEVEL DRY WEDGE POSSIBLY WORKING ACROSS THE AREA THROUGH LATE MORNING...BUT AM HESITANT TO BACK AWAY FROM THE MVFR CIGS BASED ON THEIR PERSISTENCE SO FAR. WILL GO AHEAD AND ALLOW THE CIGS TO LIFT UP INTO VFR THIS AFTERNOON BUT CONTINUE TO LEAN PESSIMISTIC AND HANG ON TO AT LEAST A BKN VFR CLOUD DECK THROUGH TONIGHT. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SUNDAY INTO MONDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU/HICKMAN SHORT TERM...BINAU LONG TERM...BINAU AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
639 AM EST THU NOV 13 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR REMAINS ENTRENCHED OVER THE EASTERN TWO THIRDS OF THE UNITED STATES. SPRAWLING SURFACE HIGH PRESSURE WILL PROVIDE DRY WEATHER THROUGH THE END OF THE WORK WEEK AND INTO THE FIRST HALF OF THE WEEKEND. A COUPLE OF WEATHER SYSTEMS SHIFTING THROUGH THE TENNESSEE AND OHIO VALLEYS SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO ON SUNDAY AFTERNOON AND EVENING. THE COLDEST AIR OF THE SEASON IS POISED TO MOVE INTO THE AREA IN THE WAKE OF THESE SYSTEMS EARLY NEXT WEEK...WITH HIGHS REMAINING BELOW FREEZING...AND LOWS IN THE TEENS AND BRISK WINDS. && .NEAR TERM /THROUGH TONIGHT/... RADAR MOSAICS THIS MORNING HAVE BEEN TRACKING A VERY NARROW BAND OF LIGHT SNOW ACROSS CNTL/NRN IND STREAKING INTO NWRN OH. THIS LINES UP VERY WELL WITH RAP/NAM 600MB FRONTOGENETIC FORCING ON THE ANTICYCLONIC SHEAR SIDE OF NARROW/INTENSE 130KT JET RUNNING FROM NRN IL INTO MI AND EVENTUALLY ONTARIO. THIS SEEN ON 1.5 PV SURFACE /DYNAMIC TROPOPAUSE/. MAIN SHORTWAVE TROUGH/PV LOWERING IN THIS FLOW IS APPROACHING CHICAGO AND IS TRANSLATING QUICKLY DOWNSTREAM /NORTHEAST/ AND WILL BE NEAR DETROIT BY MIDDAY. MEANWHILE...LOW LEVEL COLD ADVECTION CONTINUES AS LARGE ERN NOAM TROUGH CONTINUES TO DEVELOP SWRD AND UPSTREAM 13.00Z RAOBS CONFIRM A HEALTHY/DEEP SOURCE OF COLD AIR IN PLACE AND SHIFTING SLOWLY SOUTHEAST WITH KILN /-9C AT 850MB/ GIVING WAY TO -11C TO -14C READINGS AT KILX/KDTX/KGRB/KMPX. SAID RADAR MOSAICS ALSO SHOWING SLOWLY GROWING LAKE-EFFECT SNOW SHOWERS/FLURRIES IN LEE OF WARM LAKE MICHIGAN WATERS. 13.00Z KILN SOUNDING CONTINUED TO SHOW THIN /30 MB DEEP/ LAYER OF SATURATION WITH RESPECT TO ICE BETWEEN 850MB AND 880MB /ABOUT -10C/. GOES FOG PRODUCT CONFIRMS A LARGE AMOUNT OF STRATUS ACROSS THE AREA BACK INTO MUCH OF INDIANA WHERE MID LVL FGEN AND APPROACHING PV ANOMALY ARE PRODUCING THICKER/WIDESPREAD CLOUD ATOP THE LARGE STRATUS SHIELD. SEEMS TO BE JUST ENOUGH SEPARATION /5KFT/ BETWEEN MID LEVEL MOISTURE AND LOWER LEVEL MOISTURE TO PREVENT MUCH IN THE WAY OF SEEDER FEEDER FROM THE MID DECK TO THE LOWER CLOUD AS IT CROSSES THE CWA THIS MORNING. SO...CONSIDERED RUNNING A FLURRY MENTION ESP THIS MORNING ACROSS WCNTL/CNTL OHIO AS WEAKENING BAND OF FGEN FORCING SLIDES EAST/NORTHEAST ACROSS NORTHERN HALF OF OHIO. STILL MAY DO AT SOME POINT IN THE NEXT FEW HOURS OF RADAR EVAL BUT FOR RIGHT NOW NOT SEEING ENOUGH TO MENTION. AM REMAINING PESSIMISTIC ON CLOUDS TODAY...GOING MOSTLY CLOUDY MOST AREAS. WITH MOISTURE SO THIN...AND OVERALL PROFILE BECOMING QUITE SUBSIDENT IN THE WAKE OF THE WAVE/FORCING THIS MORNING...SOME HOLES COULD BE CHEWED IN THE STRATUS ESP THIS AFTN BUT CONSIDERING ITS NOVEMBER...SUBSIDENCE INVERSION NOT GOING AWAY...AND CAA/LAKE MICHIGAN FEED OF RH IS PRESENT ON MOST NWP SOLUTIONS...WILL JUST RIDE THE CLOUDS UNTIL WE SEE MORE SUBSTANTIAL EROSION. 1000-850MB THICKNESS DERIVED EQUATIONS FROM ILN SOUNDING DATA SUGGEST HIGH TEMPS SHOULD BE A FEW DEGREES COLDER THAN PVS FORECAST...SO STARTED WITH THIS BUT NUDGED BACK TO BLENDED MOS WHICH GAVE HIGHS IN THE LOWER/MID 30S MOST AREAS. IF CLOUDS REMAIN THICK ALL DAY...LOWER SIDE OF THIS ENVELOPE IS EXPECTED. LATEST HIGHER RES NAM-WRF AND EVEN TO A DEGREE GFS DATA SUGGESTING 900-800MB RH WILL REMAIN HIGH OR EVEN INCREASE TONIGHT AS COLD ADVECTION CONTINUES WITH -14C 850MB POOL ROTATING EAST RIGHT ACROSS THE CWA TONIGHT. DESPITE SUBSIDENCE THAT CONTINUES TO INCREASE...WILL ONLY ALLOW FOR A VERY SLOW EROSION OF CLOUDS AND IT MAY VERY WELL REMAIN MOSTLY CLOUDY THROUGH THE NIGHT AS WELL. FOR THIS REASON...KEEPING MIN TEMPS ON THE WARM SIDE OF STATISTICAL MOS. AT SOME POINT MAY NEED TO MENTION A FLURRY OR LIGHT SNOW SHOWER REMAINING INTACT ALL THE WAY FROM LAKE MICHIGAN INTO AREAS NORTH OF I-70 /REF VERY WEAK SIMULATE REFLECTIVITY ON RECENT HRRR RUNS INTO AUGLAIZE/HARDIN COUNTIES/ && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THIS A QUIET...COLD PERIOD. POOL OF -14C /850MB/ AIR ONLY VERY SLOWLY MODIFIES ON FRIDAY...WITH VERY SIMILAR 925MB TEMPS AS ON THURSDAY...SO KEEPING HIGH TEMPS VERY SIMILAR TO FRIDAY WITH EMPHASIS ON RELATIVELY HIGHER TERRAIN AREAS THE COOLEST AND WARMEST OVER IN THE SCIOTO VALLEY. AM BANKING ON MORE SUNSHINE ON FRIDAY ESPECIALLY THE FURTHER SOUTH ONE GOES IN THE ILN FORECAST AREA...GIVEN TRAJECTORIES OF LOW LEVEL FLOW OFF LAKE MICHIGAN FOCUSING THE BETTER STREAMERS OF LAKE EFFECT CLOUDS INTO AREA ALONG/NORTH OF I-70. THAT BEING SAID...PESKY SUBSIDENCE INVERSION REMAINS ON 13.00Z NAM/GFS SOUNDINGS INTO FRIDAY AFTERNOON WITH STRONG DEEP TROPOSPHERIC SUBSIDENCE SIGNAL ALOFT. PLENTY OF RH ON FCST SOUNDINGS...BUT NOT AS MUCH AS THURSDAY...SO THINKING AT LEAST PARTLY CLOUDY SHOULD WORK BY AFTERNOON MOST AREAS. WE ALWAYS SEEM TO UNDERESTIMATE HOW LONG THE LOW CLOUDS HANG IN THESE FLOW REGIMES...SO LOWER CONFIDENCE HERE. AS MENTIONED IN PREVIOUS DISCUSSIONS...A CHANCE WE COULD TIE OR BARELY BREAK A RECORD LOW MAXIMUM TEMP RECORD ON FRIDAY...ONLY BECAUSE FRIDAY/S VALUES ARE A NOTICEABLE BUBBLE OF WARMTH IN THE PERIOD OF RECORD IN COMPARISON WITH DAYS AROUND IT. CMH /34 DEGREES IN 1916/ HAS THE GREATEST POTENTIAL FOLLOWED BY 32 DEGREES /CVG IN 1916/ AND DAYTON /31 DEGREES IN 1916/. IF A GOOD CLEARING TREND DOES OCCUR FRIDAY NIGHT...APPROACH AND PASSAGE OF 1032MB SURFACE HIGH ACROSS SRN OH AND KENTUCKY SHOULD MEAN LIGHT WINDS OVERNIGHT AND POTENTIAL FOR GOOD TEMP DROP. CONTINUE TO MENTION MID/UPPER TEENS MOST AREAS WITH A BIAS CORRECTION INFLUENCE ON THE TEMP GRID TO BRING OUT THE RELATIVE WARM/COOL SPOTS. WOULD NOT BE AT ALL SURPRISED TO SEE SOME OF THE REAL NOOKS AND CRANNIES PRONE TO COLD AIR SEEPAGE DROP DOWN IN THE LOWER TEENS IF SKIES GO CLEAR EARLY IN THE NIGHT. QUIET WEATHER CONTINUES INTO SATURDAY. SYSTEMS WE WILL NEED TO START WATCHING FOR LATER IN THE WEEKEND /SEE MORE IN LONG TERM DISCUSSION BELOW/ WILL BE 1) DIGGING SOUTHWARD THROUGH NRN ROCKIES...DOWN THE BACKSIDE OF ANOMALOUS WRN CANADA ANTICYCLONE...AND 2) WEAKER WAVE OVER THE FOUR CORNERS. FLOW OVER THE OHIO VALLEY WILL BE BACKING AND FLATTENING IN THE BASAL PORTION OF THE MASSIVE LONGWAVE TROUGH...AND DESPITE SOME RATHER DECENT MID LEVEL HEIGHT RISES DURING THE DAY ON SATURDAY...LOW LEVEL TEMPS WILL BE SLOWER TO RESPOND. DUE TO WEAK TRAJECTORIES/POOR MIXING ON BACKSIDE OF STRONG SURFACE HIGH PUSHING SOUTHEAST OF AREA. LIKELY TO BE AN INCREASE IN CIRRUS SAT AFTN AND WHATEVER REMNANT LOW CLOUDS MAY STILL BE HANGING AROUND...BUT THIS DAY PROBABLY HAS THE POTENTIAL OF A GOOD AMOUNT OF SUNSHINE...WHICH WILL ALLOW TEMPS BACK INTO THE MID/UPPER 30S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... WEAK WAVE OVER THE FOUR CORNERS SATURDAY MORNING WILL BE EJECTED QUICKLY ON FAST WLY FLOW THROUGH THE BASE OF L/W TROUGH INTO THE OHIO VALLEY SAT NIGHT. MOISTURE STARVED...WEAK VERTICAL MOTION SUGGESTS A CONTINUED LOW/MID RANGE MENTION OF LIGHT SNOW CHANCES LATER SATURDAY NIGHT. HAVE SLOWED DOWN THE MENTION OF SNOW A LITTLE FROM PREVIOUS FORECAST. INCREASING/THICKENING CLOUDS SAT NIGHT SHOULD KEEP LOWS A GOOD DEAL WARMER ON SAT NIGHT IN COMPARISON TO FRI NIGHT. WAVE OF INTEREST THOUGH WILL ITSELF BE DIGGING THROUGH THE FOUR CORNERS BY SUNDAY MORNING SET TO EJECT QUICKLY EAST...THOUGH AT A LOWER LATITUDE WITH IT BEING STRONGER AND A DEEPER DIG THROUGH THE L/W TROUGH. THIS WAVE WILL BEGIN TO PHASE WITH AN EVEN STRONGER SHORTWAVE DIGGING SOUTHEAST THROUGH THE WESTERN GREAT LAKES ON SUNDAY AFTERNOON...WHICH IN AN OVERALL SENSE GREATLY AMPLIFIES/SHARPENS THE LONGWAVE TROUGH. WEIGHTED GFS PROGS FOR SUNDAY/MONDAY HAVE SHOWN A STRONG AMPLIFICATION SIGNAL IN RUN- 0VER-RUN SENSE WITH THIS DEEPENING UPPER TROUGH WITH LOWERING HEIGHTS IN THE BASE OF THE TROUGH AND INCREASING HEIGHTS W/TIME ON BOTH UPSTREAM AND DOWNSTREAM RIDGES. IN RESPONSE...PRESSURES WILL FALL WELL DOWNSTREAM OF THIS PHASING OVER THE GULF COAST INTO THE APPALACHIANS SUNDAY AFTN/NIGHT WITH MOISTURE ADVECTION IN THE MID LEVELS TAKING PLACE AND INCREASING DEFORMATION/FGEN FORCING ON THE WEST SIDE OF THE APPALACHIANS INCLUDING OHIO/IND/KY. THIS SHOULD PROMOTE A NEWRD TRANSLATING BAND OF PCPN THROUGH KENTUCKY INTO OHIO/WV SUNDAY AND SUNDAY NIGHT. DPROG/DT TRENDS STILL JUMPY OVER THE LAST 24 HOURS...BUT SOME CONSENSUS STARTING TO BE SEEN WITH 12.12Z GFS AND 13.00Z GFS LOOKING SIMILAR...WHICH IS A TREND TO 12.00Z AND 12.12Z ECMWF SHOWING PRECIPITATION FOCUSING IN ERN HALF OF CWA WITH POTENTIAL FOR LIGHT ACCUMULATING SNOWS. DETERMINISTIC GFS /PARALLEL AND OPNL/ CONTINUE TO BE COLDER THAN ECMWF WITH ALL SNOW SCENARIO...WHILE RECENT ECMWF RUNS VERY STABLE IN SUGGESTING PERHAPS A RAIN/SNOW POTENTIAL IN OUR FAR SOUTHERN/EASTERN AREAS. INCREASED PCPN CHANCES BRINGING LIKELY CHANCES BACK TO CVG/ILN/CMH AND BLENDED THERMAL PROFILES OF COLDER GFS/WARMER ECMWF TO ARRIVE AT PTYPE. 12.18Z GEFS PROBS SUPPORT THE LIKELY POPS IN OUR SOUTH/EAST AT THIS TIME RANGE...AND THERE IS ACKNOWLEDGMENT THAT IF NEW 12Z DETERMINISTIC ECMWF/GFS CONTINUE TO STABILIZE THAT HIGHER CHANCES OF PCPN WILL BE NEEDED CWA-WIDE THOUGH THERE IS A TIGHT GRADIENT IN OUR WEST AS OF NOW. POTENTIAL FOR LIGHT SNOW ACCUMULATIONS FOR MANY ON SUN/SUN NIGHT. MOST CONSENSUS FOCUS RIGHT NOW IS EAST OF I-71. SYSTEM PUSHES EAST MONDAY WITH CORE OF COLDEST AIR IN THIS PATTERN DROPPING SOUTH AND THEN EAST RIGHT ACROSS THE CWA MON NIGHT AND TUES. 850MB TEMPS TO -18C SEEMS LIKELY...WHICH PUTS US AT VERY EDGE OF THE ENVELOPE IN TERMS OF THE CLIMO SPECTRUM SEEN IN BOTH GEFS AND NAEFS REFORECAST PERCENTILES...MEANING FOR WHAT IS BEING FORECAST BY THE ENSEMBLE SYSTEMS AT THIS TIME RANGE IS UNUSUAL TO BE THIS DEEP/COLD WITH THE UPPER TROUGH. M-CLIMATE NUMBERS /GEFS/ AND REFORECAST PERCENTILES /NAEFS/ ARE EITHER AT THEIR MINS OR VERY NEAR THE MIN. AUTUMN READING OF -18C AT 850 MB AT ILN/DAY HAS ONLY HAPPENED ONCE IN THE SOUNDING DATA CLIMATOLOGY ON OR BEFORE NOVEMBER 19TH HAS ONLY HAPPENED ONE TIME /12Z ON NOVEMBER 13 1986 -- -19.3C/. WITH 500MB HEIGHTS/850MB TEMPS BOTH APPROACHING BUT JUST FALLING SHY OF 3 SIGMA BELOW CLIMO...WE PROBABLY SHOULD CONSIDER THE POTENTIAL FOR RECORD TYING/BREAKING TEMPS IN ONE OR MORE OF THESE PERIODS. FOR RIGHT NOW GIVEN WE/RE STILL 5 DAYS AWAY...WILL FOCUS ON TUESDAY MAX TEMPS GIVEN THIS IS WHEN CORE OF COLDEST AIR PASSES OVERHEAD IN BASE OF THERMAL TROUGH. SO PUT TUES MAX TEMPS RIGHT AT RECORD LOW MAX VALUES FOR RIGHT NOW AND WE CAN EVALUATE FURTHER DROPS IF NEEDED. LOW CLOUDS IN LEE OF WARM GREAT LAKES MAY KEEP RECORD MINS UNATTAINABLE AND PLAYING IT THIS WAY RIGHT NOW AS RECORD LOWS ARE VERY COLD ON NOV 19TH. SOMETHING TO WATCH...EITHER WAY...VERY CHILLY FOR MID NOV BUT OUTSIDE OF FLURRY OR PERHAPS A SNOW SHOWER THREAT...MON/TUES SHOULD BE DRY. STILL LOOKS LIKE THIS STRETCH WILL END UP VERY SIMILAR TO NOVEMBER STRETCHES IN 1991...1996...AND 1997. ALL THREE OF THOSE YEARS HAD 8-9 DAY STRETCHES WHERE AVERAGE DAILY TEMPS FOR THE PERIOD WERE NEAR 30F...AND ARE SOME THE CHILLIEST EARLY-MID NOVEMBER LONGER DURATION PERIODS ON RECORD. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... MVFR/LOW VFR STRATOCUMULUS DECK IS TRYING TO ERODE AWAY FROM THE WEST WITH SOME LOW LEVEL CLEARING WORKING ACROSS MUCH OF CENTRAL INDIANA. LOWER CLOUDS ARE A LITTLE DIFFICULT TO MAKE OUT ON SATELLITE GIVEN SOME OF THE MID LEVEL CLOUDS ALSO MOVING ACROSS THE AREA...BUT IT DOES LOOK LIKE THE EASTWARD PROGRESSION OF THE LOWER CLOUD CLEARING MAY HAVE SLOWED DOWN ON THE LAST COUPLE OF IMAGES. MODELS ARE SUGGESTING A BIT OF A LOW LEVEL DRY WEDGE POSSIBLY WORKING ACROSS THE AREA THROUGH LATE MORNING...BUT AM HESITANT TO BACK AWAY FROM THE MVFR CIGS BASED ON THEIR PERSISTENCE SO FAR. WILL GO AHEAD AND ALLOW THE CIGS TO LIFT UP INTO VFR THIS AFTERNOON BUT CONTINUE TO LEAN PESSIMISTIC AND HANG ON TO AT LEAST A BKN VFR CLOUD DECK THROUGH TONIGHT. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SUNDAY INTO MONDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...BINAU AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
352 AM EST THU NOV 13 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR REMAINS ENTRENCHED OVER THE EASTERN TWO THIRDS OF THE UNITED STATES. SPRAWLING SURFACE HIGH PRESSURE WILL PROVIDE DRY WEATHER THROUGH THE END OF THE WORK WEEK AND INTO THE FIRST HALF OF THE WEEKEND. A COUPLE OF WEATHER SYSTEMS SHIFTING THROUGH THE TENNESSEE AND OHIO VALLEYS SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO ON SUNDAY AFTERNOON AND EVENING. THE COLDEST AIR OF THE SEASON IS POISED TO MOVE INTO THE AREA IN THE WAKE OF THESE SYSTEMS EARLY NEXT WEEK...WITH HIGHS REMAINING BELOW FREEZING...AND LOWS IN THE TEENS AND BRISK WINDS. && .NEAR TERM /THROUGH TONIGHT/... RADAR MOSAICS THIS MORNING HAVE BEEN TRACKING A VERY NARROW BAND OF LIGHT SNOW ACROSS CNTL/NRN IND STREAKING INTO NWRN OH. THIS LINES UP VERY WELL WITH RAP/NAM 600MB FRONTOGENETIC FORCING ON THE ANTICYCLONIC SHEAR SIDE OF NARROW/INTENSE 130KT JET RUNNING FROM NRN IL INTO MI AND EVENTUALLY ONTARIO. THIS SEEN ON 1.5 PV SURFACE /DYNAMIC TROPOPAUSE/. MAIN SHORTWAVE TROUGH/PV LOWERING IN THIS FLOW IS APPROACHING CHICAGO AND IS TRANSLATING QUICKLY DOWNSTREAM /NORTHEAST/ AND WILL BE NEAR DETROIT BY MIDDAY. MEANWHILE...LOW LEVEL COLD ADVECTION CONTINUES AS LARGE ERN NOAM TROUGH CONTINUES TO DEVELOP SWRD AND UPSTREAM 13.00Z RAOBS CONFIRM A HEALTHY/DEEP SOURCE OF COLD AIR IN PLACE AND SHIFTING SLOWLY SOUTHEAST WITH KILN /-9C AT 850MB/ GIVING WAY TO -11C TO -14C READINGS AT KILX/KDTX/KGRB/KMPX. SAID RADAR MOSAICS ALSO SHOWING SLOWLY GROWING LAKE-EFFECT SNOW SHOWERS/FLURRIES IN LEE OF WARM LAKE MICHIGAN WATERS. 13.00Z KILN SOUNDING CONTINUED TO SHOW THIN /30 MB DEEP/ LAYER OF SATURATION WITH RESPECT TO ICE BETWEEN 850MB AND 880MB /ABOUT -10C/. GOES FOG PRODUCT CONFIRMS A LARGE AMOUNT OF STRATUS ACROSS THE AREA BACK INTO MUCH OF INDIANA WHERE MID LVL FGEN AND APPROACHING PV ANOMALY ARE PRODUCING THICKER/WIDESPREAD CLOUD ATOP THE LARGE STRATUS SHIELD. SEEMS TO BE JUST ENOUGH SEPARATION /5KFT/ BETWEEN MID LEVEL MOISTURE AND LOWER LEVEL MOISTURE TO PREVENT MUCH IN THE WAY OF SEEDER FEEDER FROM THE MID DECK TO THE LOWER CLOUD AS IT CROSSES THE CWA THIS MORNING. SO...CONSIDERED RUNNING A FLURRY MENTION ESP THIS MORNING ACROSS WCNTL/CNTL OHIO AS WEAKENING BAND OF FGEN FORCING SLIDES EAST/NORTHEAST ACROSS NORTHERN HALF OF OHIO. STILL MAY DO AT SOME POINT IN THE NEXT FEW HOURS OF RADAR EVAL BUT FOR RIGHT NOW NOT SEEING ENOUGH TO MENTION. AM REMAINING PESSIMISTIC ON CLOUDS TODAY...GOING MOSTLY CLOUDY MOST AREAS. WITH MOISTURE SO THIN...AND OVERALL PROFILE BECOMING QUITE SUBSIDENT IN THE WAKE OF THE WAVE/FORCING THIS MORNING...SOME HOLES COULD BE CHEWED IN THE STRATUS ESP THIS AFTN BUT CONSIDERING ITS NOVEMBER...SUBSIDENCE INVERSION NOT GOING AWAY...AND CAA/LAKE MICHIGAN FEED OF RH IS PRESENT ON MOST NWP SOLUTIONS...WILL JUST RIDE THE CLOUDS UNTIL WE SEE MORE SUBSTANTIAL EROSION. 1000-850MB THICKNESS DERIVED EQUATIONS FROM ILN SOUNDING DATA SUGGEST HIGH TEMPS SHOULD BE A FEW DEGREES COLDER THAN PVS FORECAST...SO STARTED WITH THIS BUT NUDGED BACK TO BLENDED MOS WHICH GAVE HIGHS IN THE LOWER/MID 30S MOST AREAS. IF CLOUDS REMAIN THICK ALL DAY...LOWER SIDE OF THIS ENVELOPE IS EXPECTED. LATEST HIGHER RES NAM-WRF AND EVEN TO A DEGREE GFS DATA SUGGESTING 900-800MB RH WILL REMAIN HIGH OR EVEN INCREASE TONIGHT AS COLD ADVECTION CONTINUES WITH -14C 850MB POOL ROTATING EAST RIGHT ACROSS THE CWA TONIGHT. DESPITE SUBSIDENCE THAT CONTINUES TO INCREASE...WILL ONLY ALLOW FOR A VERY SLOW EROSION OF CLOUDS AND IT MAY VERY WELL REMAIN MOSTLY CLOUDY THROUGH THE NIGHT AS WELL. FOR THIS REASON...KEEPING MIN TEMPS ON THE WARM SIDE OF STATISTICAL MOS. AT SOME POINT MAY NEED TO MENTION A FLURRY OR LIGHT SNOW SHOWER REMAINING INTACT ALL THE WAY FROM LAKE MICHIGAN INTO AREAS NORTH OF I-70 /REF VERY WEAK SIMULATE REFLECTIVITY ON RECENT HRRR RUNS INTO AUGLAIZE/HARDIN COUNTIES/ && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THIS A QUIET...COLD PERIOD. POOL OF -14C /850MB/ AIR ONLY VERY SLOWLY MODIFIES ON FRIDAY...WITH VERY SIMILAR 925MB TEMPS AS ON THURSDAY...SO KEEPING HIGH TEMPS VERY SIMILAR TO FRIDAY WITH EMPHASIS ON RELATIVELY HIGHER TERRAIN AREAS THE COOLEST AND WARMEST OVER IN THE SCIOTO VALLEY. AM BANKING ON MORE SUNSHINE ON FRIDAY ESPECIALLY THE FURTHER SOUTH ONE GOES IN THE ILN FORECAST AREA...GIVEN TRAJECTORIES OF LOW LEVEL FLOW OFF LAKE MICHIGAN FOCUSING THE BETTER STREAMERS OF LAKE EFFECT CLOUDS INTO AREA ALONG/NORTH OF I-70. THAT BEING SAID...PESKY SUBSIDENCE INVERSION REMAINS ON 13.00Z NAM/GFS SOUNDINGS INTO FRIDAY AFTERNOON WITH STRONG DEEP TROPOSPHERIC SUBSIDENCE SIGNAL ALOFT. PLENTY OF RH ON FCST SOUNDINGS...BUT NOT AS MUCH AS THURSDAY...SO THINKING AT LEAST PARTLY CLOUDY SHOULD WORK BY AFTERNOON MOST AREAS. WE ALWAYS SEEM TO UNDERESTIMATE HOW LONG THE LOW CLOUDS HANG IN THESE FLOW REGIMES...SO LOWER CONFIDENCE HERE. AS MENTIONED IN PREVIOUS DISCUSSIONS...A CHANCE WE COULD TIE OR BARELY BREAK A RECORD LOW MAXIMUM TEMP RECORD ON FRIDAY...ONLY BECAUSE FRIDAY/S VALUES ARE A NOTICEABLE BUBBLE OF WARMTH IN THE PERIOD OF RECORD IN COMPARISON WITH DAYS AROUND IT. CMH /34 DEGREES IN 1916/ HAS THE GREATEST POTENTIAL FOLLOWED BY 32 DEGREES /CVG IN 1916/ AND DAYTON /31 DEGREES IN 1916/. IF A GOOD CLEARING TREND DOES OCCUR FRIDAY NIGHT...APPROACH AND PASSAGE OF 1032MB SURFACE HIGH ACROSS SRN OH AND KENTUCKY SHOULD MEAN LIGHT WINDS OVERNIGHT AND POTENTIAL FOR GOOD TEMP DROP. CONTINUE TO MENTION MID/UPPER TEENS MOST AREAS WITH A BIAS CORRECTION INFLUENCE ON THE TEMP GRID TO BRING OUT THE RELATIVE WARM/COOL SPOTS. WOULD NOT BE AT ALL SURPRISED TO SEE SOME OF THE REAL NOOKS AND CRANNIES PRONE TO COLD AIR SEEPAGE DROP DOWN IN THE LOWER TEENS IF SKIES GO CLEAR EARLY IN THE NIGHT. QUIET WEATHER CONTINUES INTO SATURDAY. SYSTEMS WE WILL NEED TO START WATCHING FOR LATER IN THE WEEKEND /SEE MORE IN LONG TERM DISCUSSION BELOW/ WILL BE 1) DIGGING SOUTHWARD THROUGH NRN ROCKIES...DOWN THE BACKSIDE OF ANOMALOUS WRN CANADA ANTICYCLONE...AND 2) WEAKER WAVE OVER THE FOUR CORNERS. FLOW OVER THE OHIO VALLEY WILL BE BACKING AND FLATTENING IN THE BASAL PORTION OF THE MASSIVE LONGWAVE TROUGH...AND DESPITE SOME RATHER DECENT MID LEVEL HEIGHT RISES DURING THE DAY ON SATURDAY...LOW LEVEL TEMPS WILL BE SLOWER TO RESPOND. DUE TO WEAK TRAJECTORIES/POOR MIXING ON BACKSIDE OF STRONG SURFACE HIGH PUSHING SOUTHEAST OF AREA. LIKELY TO BE AN INCREASE IN CIRRUS SAT AFTN AND WHATEVER REMNANT LOW CLOUDS MAY STILL BE HANGING AROUND...BUT THIS DAY PROBABLY HAS THE POTENTIAL OF A GOOD AMOUNT OF SUNSHINE...WHICH WILL ALLOW TEMPS BACK INTO THE MID/UPPER 30S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... WEAK WAVE OVER THE FOUR CORNERS SATURDAY MORNING WILL BE EJECTED QUICKLY ON FAST WLY FLOW THROUGH THE BASE OF L/W TROUGH INTO THE OHIO VALLEY SAT NIGHT. MOISTURE STARVED...WEAK VERTICAL MOTION SUGGESTS A CONTINUED LOW/MID RANGE MENTION OF LIGHT SNOW CHANCES LATER SATURDAY NIGHT. HAVE SLOWED DOWN THE MENTION OF SNOW A LITTLE FROM PREVIOUS FORECAST. INCREASING/THICKENING CLOUDS SAT NIGHT SHOULD KEEP LOWS A GOOD DEAL WARMER ON SAT NIGHT IN COMPARISON TO FRI NIGHT. WAVE OF INTEREST THOUGH WILL ITSELF BE DIGGING THROUGH THE FOUR CORNERS BY SUNDAY MORNING SET TO EJECT QUICKLY EAST...THOUGH AT A LOWER LATITUDE WITH IT BEING STRONGER AND A DEEPER DIG THROUGH THE L/W TROUGH. THIS WAVE WILL BEGIN TO PHASE WITH AN EVEN STRONGER SHORTWAVE DIGGING SOUTHEAST THROUGH THE WESTERN GREAT LAKES ON SUNDAY AFTERNOON...WHICH IN AN OVERALL SENSE GREATLY AMPLIFIES/SHARPENS THE LONGWAVE TROUGH. WEIGHTED GFS PROGS FOR SUNDAY/MONDAY HAVE SHOWN A STRONG AMPLIFICATION SIGNAL IN RUN- 0VER-RUN SENSE WITH THIS DEEPENING UPPER TROUGH WITH LOWERING HEIGHTS IN THE BASE OF THE TROUGH AND INCREASING HEIGHTS W/TIME ON BOTH UPSTREAM AND DOWNSTREAM RIDGES. IN RESPONSE...PRESSURES WILL FALL WELL DOWNSTREAM OF THIS PHASING OVER THE GULF COAST INTO THE APPALACHIANS SUNDAY AFTN/NIGHT WITH MOISTURE ADVECTION IN THE MID LEVELS TAKING PLACE AND INCREASING DEFORMATION/FGEN FORCING ON THE WEST SIDE OF THE APPALACHIANS INCLUDING OHIO/IND/KY. THIS SHOULD PROMOTE A NEWRD TRANSLATING BAND OF PCPN THROUGH KENTUCKY INTO OHIO/WV SUNDAY AND SUNDAY NIGHT. DPROG/DT TRENDS STILL JUMPY OVER THE LAST 24 HOURS...BUT SOME CONSENSUS STARTING TO BE SEEN WITH 12.12Z GFS AND 13.00Z GFS LOOKING SIMILAR...WHICH IS A TREND TO 12.00Z AND 12.12Z ECMWF SHOWING PRECIPITATION FOCUSING IN ERN HALF OF CWA WITH POTENTIAL FOR LIGHT ACCUMULATING SNOWS. DETERMINISTIC GFS /PARALLEL AND OPNL/ CONTINUE TO BE COLDER THAN ECMWF WITH ALL SNOW SCENARIO...WHILE RECENT ECMWF RUNS VERY STABLE IN SUGGESTING PERHAPS A RAIN/SNOW POTENTIAL IN OUR FAR SOUTHERN/EASTERN AREAS. INCREASED PCPN CHANCES BRINGING LIKELY CHANCES BACK TO CVG/ILN/CMH AND BLENDED THERMAL PROFILES OF COLDER GFS/WARMER ECMWF TO ARRIVE AT PTYPE. 12.18Z GEFS PROBS SUPPORT THE LIKELY POPS IN OUR SOUTH/EAST AT THIS TIME RANGE...AND THERE IS ACKNOWLEDGMENT THAT IF NEW 12Z DETERMINISTIC ECMWF/GFS CONTINUE TO STABILIZE THAT HIGHER CHANCES OF PCPN WILL BE NEEDED CWA-WIDE THOUGH THERE IS A TIGHT GRADIENT IN OUR WEST AS OF NOW. POTENTIAL FOR LIGHT SNOW ACCUMULATIONS FOR MANY ON SUN/SUN NIGHT. MOST CONSENSUS FOCUS RIGHT NOW IS EAST OF I-71. SYSTEM PUSHES EAST MONDAY WITH CORE OF COLDEST AIR IN THIS PATTERN DROPPING SOUTH AND THEN EAST RIGHT ACROSS THE CWA MON NIGHT AND TUES. 850MB TEMPS TO -18C SEEMS LIKELY...WHICH PUTS US AT VERY EDGE OF THE ENVELOPE IN TERMS OF THE CLIMO SPECTRUM SEEN IN BOTH GEFS AND NAEFS REFORECAST PERCENTILES...MEANING FOR WHAT IS BEING FORECAST BY THE ENSEMBLE SYSTEMS AT THIS TIME RANGE IS UNUSUAL TO BE THIS DEEP/COLD WITH THE UPPER TROUGH. M-CLIMATE NUMBERS /GEFS/ AND REFORECAST PERCENTILES /NAEFS/ ARE EITHER AT THEIR MINS OR VERY NEAR THE MIN. AUTUMN READING OF -18C AT 850 MB AT ILN/DAY HAS ONLY HAPPENED ONCE IN THE SOUNDING DATA CLIMATOLOGY ON OR BEFORE NOVEMBER 19TH HAS ONLY HAPPENED ONE TIME /12Z ON NOVEMBER 13 1986 -- -19.3C/. WITH 500MB HEIGHTS/850MB TEMPS BOTH APPROACHING BUT JUST FALLING SHY OF 3 SIGMA BELOW CLIMO...WE PROBABLY SHOULD CONSIDER THE POTENTIAL FOR RECORD TYING/BREAKING TEMPS IN ONE OR MORE OF THESE PERIODS. FOR RIGHT NOW GIVEN WE/RE STILL 5 DAYS AWAY...WILL FOCUS ON TUESDAY MAX TEMPS GIVEN THIS IS WHEN CORE OF COLDEST AIR PASSES OVERHEAD IN BASE OF THERMAL TROUGH. SO PUT TUES MAX TEMPS RIGHT AT RECORD LOW MAX VALUES FOR RIGHT NOW AND WE CAN EVALUATE FURTHER DROPS IF NEEDED. LOW CLOUDS IN LEE OF WARM GREAT LAKES MAY KEEP RECORD MINS UNATTAINABLE AND PLAYING IT THIS WAY RIGHT NOW AS RECORD LOWS ARE VERY COLD ON NOV 19TH. SOMETHING TO WATCH...EITHER WAY...VERY CHILLY FOR MID NOV BUT OUTSIDE OF FLURRY OR PERHAPS A SNOW SHOWER THREAT...MON/TUES SHOULD BE DRY. STILL LOOKS LIKE THIS STRETCH WILL END UP VERY SIMILAR TO NOVEMBER STRETCHES IN 1991...1996...AND 1997. ALL THREE OF THOSE YEARS HAD 8-9 DAY STRETCHES WHERE AVERAGE DAILY TEMPS FOR THE PERIOD WERE NEAR 30F...AND ARE SOME THE CHILLIEST EARLY-MID NOVEMBER LONGER DURATION PERIODS ON RECORD. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... THE SOLID STRATOCUMULUS DECK REMAINS IN PLACE ACROSS THE REGION EARLY THIS MORNING. IT HAS BEEN TRYING TO ERODE EVER SO SLOWLY BACK TO OUR SOUTHWEST ACROSS SOUTHERN ILLINOIS AND FAR WESTERN KENTUCKY. MODELS CONTINUE TO HAVE A DIFFICULT TIME HANDLING THESE LOWER CLOUDS BUT GIVEN THE TREND OF THE PAST DAY OR SO AND THE FACT THAT AT LEAST SOME WEAK LOW LEVEL CAA WILL PERSIST THROUGH THE DAY...WILL HANG ON TO THE CLOUDS THROUGH THIS AFTERNOON. THE CLOUD DECK HAS BEEN FLUCTUATING BETWEEN HIGH MVFR AND LOW VFR BUT AS WE PROGRESS THROUGH THE EARLY MORNING HOURS...WOULD EXPECT A BIT OF A LOWERING INTO A MORE CONSISTENT MVFR DECK BEFORE LIFTING BACK UP INTO VFR THIS AFTERNOON. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SUNDAY INTO MONDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...BINAU AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1235 AM EST THU NOV 13 2014 .SYNOPSIS... A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGHOUT MUCH OF NEXT WEEK AS A LARGE POOL OF UNSEASONABLY COLD AIR BECOMES ENTRENCHED OVER THE EASTERN TWO THIRDS OF THE UNITED STATES. SPRAWLING SURFACE HIGH PRESSURE WILL PROVIDE DRY WEATHER THROUGH THE END OF THE WEEK AND INTO THE WEEKEND. A WEATHER SYSTEM SHIFTING THROUGH ON SUNDAY AND SUNDAY NIGHT WILL BRING THE THREAT OF SOME SNOW TO THE AREA...PERHAPS MIXING WITH OR CHANGING TO RAIN ACROSS KENTUCKY AND SOUTHEAST OHIO. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... A PERSISTENT STRATOCUMULUS DECK (2500-3500 FEET) IS EXPECTED TO REMAIN IN PLACE OVERNIGHT. RECENT GFS/NAM RUNS HAVE NOT SEEMED TO CAPTURE THIS LAYER OF RH VERY WELL (THE 00Z NAM WAS A SLIGHT IMPROVEMENT)...BUT THE 01Z RAP IS IN GOOD SHAPE WITH SATURATION INDICATED AT 900MB. THE RAP/HRRR WERE USED AS GUIDANCE FOR SOME SLIGHT UPWARD ADJUSTMENTS TO THE MIN TEMP AND SKY COVER FORECASTS...WITH THE EXPECTATION THAT MOST CLOUDS SHOULD REMAIN IN PLACE THROUGH MORNING. PREVIOUS DISCUSSION > COLD WEATHER PATTERN WITH TEMPERATURES 15 TO 20 DEGREES BELOW NORMAL. BROAD MEAN TROF WITH AN ELONGATED CENTERED ORIENTED E-W FROM THE NRN PLAINS THRU THE GREAT LAKES. DUMBBELL EFFECT TO TAKE PLACE AS INITIAL S/W PIVOTS INTO SE CANADA THE NEXT WESTERN S/W AXIS TO WORK INTO THE UPR MS VLY TONIGHT. SFC HIGH PRESSURE OF ARCTIC ORIGIN TO SLOWLY BUILD SOUTH INTO THE CENTRAL PLAINS AND NOSE INTO THE OHIO VALLEY. ILN/S 12Z SOUNDING SHOWED MOISTURE AROUND 900 MB TRAPPED BELOW A STRONG SUBSIDENCE INVERSION. LATEST VISIBLE SATL IMGRY SHOWS CLOUD COVER OVER OHIO BACK THRU INDIANA INTO ILLINOIS. SOME HOLES DEVELOPED IN THIS SHALLOW MOISTURE BUT LATEST SATL TRENDS SHOWING THESE HOLES FILLING IN. 12Z GFS SOLN IS TOO QUICK WITH DRYING AND PREVIOUS RUN WAS ALREADY NOT VERIFYING WELL. NAM SOLN HOLDS ONTO MOISTURE LONGER...PERHAPS ONLY ALLOWING A FEW MORE BREAKS INTO THE SW LATE. IN LOW LEVEL CAA PATTERN DO NOT EXPECT QUICK CLEARING AT NIGHT. WILL LEAN TOWARD HOLDING ONTO THE CLOUDS LONGER AND ADJUST THE SKY GRIDS ACCORDINGLY. OVERNIGHT LOWS WILL BE COLD...RANGING FROM THE MID 20S WEST TO THE UPPER 20S EAST. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/... BROAD MID/UPR LEVEL TROF OVER THE GREAT LAKES WITH UPSTREAM S/W TO ROTATE SE. ASSOCIATED SHEARED VORT AXIS TO MOVE THRU THE REGION THURSDAY. SOME MID/UPPER LEVEL FORCING WITH THIS FEATURE ON THURSDAY. A SNOW SHOWER OR FLURRY IS NOT OUT OF THE QUESTION...ESPECIALLY ACROSS THE NORTH. NO SIGNIFICANT LOW LEVEL FORCING AND DRY LAYER BETWEEN MID CLOUDS AND LOWER CLOUDS LEANS TOWARD A DRY SOLN. CLOUD COVER AND LOW LEVEL CAA WILL KEEP TEMPERATURES FROM RISING MUCH ON THURSDAY. EXPECT HIGHS ABOUT 20 DEGREES BELOW NORMAL...RANGING FROM THE LOWER 30S NORTHWEST TO THE UPPER 30S SE. EXPECT ONLY SOME PARTIAL CLEARING THURSDAY NIGHT...WITH THE BEST CHANCE ACRS THE SW. OVERNIGHT LOWS GENERALLY EXPECTED TO BE IN THE LOWER 20S BY FRIDAY MORNING. THE CENTER OF THE ARCTIC HIGH PRESSURE TO BUILD INTO THE MS VLY FRIDAY AND OVER THE OHIO VALLEY FRIDAY NIGHT. EXPECT SOME EROSION OF THE CLOUDS FROM THE SW FRIDAY AND THEN BETTER CHANCE FOR CLEARING FRIDAY NIGHT WITH THE HIGH BUILDING IN. COLD HIGHS ON FRIDAY IN THE LOWER/MIDDLE 30S. FRIDAY NIGHT LOOKS TO BE THE COLDEST NIGHT OF THE SHORT TERM WITH LIGHT WINDS AND DIMINISHING CLOUDS. LOWS EXPECTED TO RANGE FROM THE UPPER TEENS TO THE LOWER 20S. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE AND A DRY AIRMASS WILL BE PUSHING EAST EARLY SATURDAY. SHORT WAVE ENERGY AND LIMITED MOISTURE TRAVELING THROUGH THE GREAT LAKES WILL BRING A CHANCE OF SNOW SHOWERS SATURDAY NIGHT. MOISTURE AND ENERGY ARRIVING ON A SOUTHWEST UPPER FLOW MAY RESULT IN MORE SNOW SHOWERS SUNDAY AND MONDAY. DUE TO MODEL DIFFERENCES... TIMING AND AMOUNTS OF PRECIP ARE UNCERTAIN AT THIS POINT. THERMAL PROFILES INDICATE RAIN IN SOUTHERN LOCATIONS MONDAY AFTERNOON. FOR TUESDAY AND WEDNESDAY...HIGH PRESSURE AND A LACK OF MOISTURE SHOULD PRODUCE DRY WEATHER. WELL BELOW NORMAL 500 MB HEIGHTS ARE IN STORE THROUGH THE PERIOD. COUPLED WITH A LOW LEVEL FLOW CARRYING COLDER AIR FROM THE NORTH...TEMPERATURES WILL BE FAR BENEATH SEASONAL AVERAGES. HIGHS MAINLY IN THE 30S SATURDAY THROUGH MONDAY WILL BE FOLLOWED BY EVEN COLDER READINGS IN THE UPPER 20S ON TUESDAY BEFORE REBOUNDING BACK TO THE 30S FOR WEDNESDAY. THIS COMPARES TO NORMAL HIGHS IN THE LOWER 50S. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... THE SOLID STRATOCUMULUS DECK REMAINS IN PLACE ACROSS THE REGION EARLY THIS MORNING. IT HAS BEEN TRYING TO ERODE EVER SO SLOWLY BACK TO OUR SOUTHWEST ACROSS SOUTHERN ILLINOIS AND FAR WESTERN KENTUCKY. MODELS CONTINUE TO HAVE A DIFFICULT TIME HANDLING THESE LOWER CLOUDS BUT GIVEN THE TREND OF THE PAST DAY OR SO AND THE FACT THAT AT LEAST SOME WEAK LOW LEVEL CAA WILL PERSIST THROUGH THE DAY...WILL HANG ON TO THE CLOUDS THROUGH THIS AFTERNOON. THE CLOUD DECK HAS BEEN FLUCTUATING BETWEEN HIGH MVFR AND LOW VFR BUT AS WE PROGRESS THROUGH THE EARLY MORNING HOURS...WOULD EXPECT A BIT OF A LOWERING INTO A MORE CONSISTENT MVFR DECK BEFORE LIFTING BACK UP INTO VFR THIS AFTERNOON. OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES POSSIBLE SUNDAY INTO MONDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...AR NEAR TERM...HATZOS/AR SHORT TERM...AR LONG TERM...CONIGLIO AVIATION...JGL
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
719 PM CST FRI NOV 14 2014 .UPDATE... ADJUSTED PRECIPITATION TYPE ACROSS NORTHERN OKLAHOMA AFTER MIDNIGHT TONIGHT THROUGH EARLY SATURDAY AFTERNOON TO INCLUDE SLEET. && .DISCUSSION... A LIGHT WINTRY MIX OF MAINLY LIGHT SLEET AND LIGHT SNOW IS POSSIBLE AFTER MIDNIGHT TONIGHT THROUGH 3 PM SATURDAY ACROSS NORTHERN OKLAHOMA. LATEST HRRR RUNS HAVE BEEN DEPICTING LIGHT PRECIPITATION DEVELOPING AS LIFT INCREASES IN NORTHWEST OKLAHOMA MIDNIGHT TO 4 AM TONIGHT...THEN SPREADING EAST...AFFECTING AREAS NORTH OF A GAGE TO STILLWATER LINE. FORECAST PRECIPITATION CHANCES ARE IN GOOD SHAPE AND WERE NOT ALTERED. BASED ON THE LATEST 00Z NEARBY UPPER AIR SOUNDINGS AND TOP DOWN SOUNDING METHODOLOGY...BELIEVE ANY PRECIPITATION REACHING THE GROUND WOULD MAINLY BE LIGHT SLEET AS PRECIPITATION ALOFT WOULD PARTIALLY OR COMPLETELY MELT WITH A 720-800 MB WARM NOSE OF +1 TO +6C THEN REFREEZE 800-850 MB WITH TEMPERATURES AROUND -9C. LIGHT SNOW WOULD BE POSSIBLE IF PRECIPITATION INTENSITY BECOMES HEAVY ENOUGH TO ALLOW EVAPORATIONAL COOLING TO ERODE THE MID LEVEL WARM NOSE. LATEST RAP13 RUNS HINT THAT THIS COULD OCCUR NORTH OF AN ALVA TO STILLWATER LINE AFTER 4 AM TONIGHT. REGARDLESS OF PRECIPITATION TYPE...ANY PRECIPITATION AMOUNTS APPEAR TO BE LIGHT IN NORTHERN OKLAHOMA WITH THE HEAVIER AMOUNTS FARTHER NORTH ACROSS NORTHERN KANSAS LATE TONIGHT INTO SATURDAY. COULD NOT COMPLETELY RULE OUT A DUSTING OF SLEET OR SNOW ACCUMULATIONS MIDNIGHT TONIGHT TO 3 PM SATURDAY OVER NORTHERN OKLAHOMA...BUT THINK IMPACTS WILL BE MINIMAL DUE TO THE LIGHT NATURE OF PRECIPITATION AND LACK OF SIGNIFICANT NEARBY MOISTURE. HOWEVER...WITH SURFACE TEMPERATURES BELOW FREEZING...A FEW SLICK SPOTS COULD DEVELOP. WILL CONTINUE TO MONITOR. PRODUCTS HAVE BEEN UPDATED. NO WINTER WEATHER ADVISORIES ARE EXPECTED TO BE ISSUED FOR TONIGHT THROUGH SATURDAY AFTERNOON AT THIS TIME. MBS && .PREV DISCUSSION... /ISSUED 542 PM CST FRI NOV 14 2014/ DISCUSSION... AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW. AVIATION... OVERALL...VFR CONDITIONS ARE EXPECTED TO CONTINUE. A LIGHT WINTRY MIX OF PRECIPITATION IS POSSIBLE NORTH OF KCSM- KOKC 06-18Z. KEPT PROB30 GROUP FOR MVFR CONDITIONS AND -SN AT KPNC 12-17Z WHERE CONFIDENCE IS MODERATE. OTHERWISE...CONFIDENCE OF PRECIPITATION OCCURRENCE IS TOO LOW TO MENTION. SOUTH WINDS WILL BE BECOME GUSTY AT MANY SITES 12-16Z...THEN DIMINISH 20-24Z. A COLD FRONT WILL BRING A WIND SHIFT TO THE NORTH NEAR KWWR AND KGAG AFTER 21Z. MBS PREV DISCUSSION... /ISSUED 255 PM CST FRI NOV 14 2014/ DISCUSSION... SHORT TERM...(TONIGHT-SUNDAY NIGHT) LOW CLOUDS SHOULD CONTINUE TO ERODE THROUGH THE AFTERNOON WHILE HIGH CLOUDS SLOWLY INCREASE. A QUICK MOVING SYSTEM WILL APPROACH TONIGHT AND SHOULD CLEAR THE SOUTHERN PLAINS BY SATURDAY AFTERNOON. THE OVERALL TREND WITH THIS SYSTEM...HAS BEEN BETTER CHANCES FOR PRECIPITATION MAINLY NORTH OF OKLAHOMA. WILL KEEP LOW CHANCES FOR LIGHT SNOW ACROSS NORTHERN OKLAHOMA FROM LATE TONIGHT THROUGH LATE SATURDAY MORNING. A WARM NOSE BELOW 7H ACROSS NORTHWEST OKLAHOMA MAY RESULT IN SOME SLEET OVERNIGHT. PRECIPITATION AMOUNTS WILL BE LIGHT WITH THIS SYSTEM. ANOTHER PUSH OF RATHER COLD AIR WILL BEGIN TO ENTER NORTHWEST OKLAHOMA LATE SATURDAY AFTERNOON AND EVENING. GUSTY NORTHERLY WINDS CAN BE EXPECTED ACROSS MOST OF OKLAHOMA BY EARLY/MID SUNDAY MORNING. AN APPROACHING WAVE WILL BRING A DECENT CHANCE OF LIGHT SNOW SUNDAY MORNING AND AFTERNOON. MOST MODELS INDICATE THE BEST LIFT OCCURRING ACROSS NORTHERN OKLAHOMA SUNDAY MORNING THEN SHIFTING SOUTHWARD DURING THE AFTERNOON. A LITTLE UNSURE ON AMOUNTS...BUT EXPECT SOME AREAS NORTH OF OF I-40 SHOULD SEE AN INCH OF SNOW WITH 2 INCH AMOUNTS POSSIBLE. WITH THE RECENT COLD WEATHER...ANY SNOW THAT FALLS WILL ACCUMULATE AND MAY CAUSE MINOR TRAFFIC DELAYS. LONG TERM...(MONDAY-THURSDAY) A GRADUAL WARMING TREND WILL BEGIN EARLY NEXT WEEK, WITH SURFACE WINDS BECOMING SOUTHERLY BY MIDWEEK. AN UPPER WAVE WILL MOVE ACROSS THE AREA ON THURSDAY, BRINGING LOW POPS FOR RAIN ACROSS SOUTHEAST OKLAHOMA. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM APPEARS TO BE WEAK, STALLING ACROSS NORTHWEST OKLAHOMA BEFORE LIFTING BACK TO THE NORTH. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 27 46 27 29 / 0 20 10 50 HOBART OK 28 48 27 29 / 10 10 10 40 WICHITA FALLS TX 29 53 32 33 / 0 10 10 30 GAGE OK 25 42 20 29 / 20 10 30 60 PONCA CITY OK 25 41 24 29 / 10 30 20 60 DURANT OK 28 45 34 39 / 0 10 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 04/17
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1206 AM CST THU NOV 13 2014 .AVIATION...06Z TAF ISSUANCE... VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. OVC MID LEVEL CLOUDS WILL PERSIST THROUGH MUCH OF THE PERIOD... SLIGHTLY IMPROVING THROUGH THE AFTN FROM N-S. GUSTY NORTH WINDS WILL PERSIST THROUGH 18Z... WITH WINDS RELAXING THROUGH THE LATE AFTERNOON AND EVENING. JTK && .PREV DISCUSSION... /ISSUED 1011 PM CST WED NOV 12 2014/ UPDATE... ADJUSTED PRECIP/WX FOR OVERNIGHT. DISCUSSION... WATCHING RADAR/OBS TRENDS CLOSELY... LIGHT AREA OF SNOW LOOKS TO BE PERSISTING JUST NORTH/ALONG THE OK/KS BORDER. RECENT HRRR DISPENSES WITH THIS AREA QUICK THROUGH 13/04Z... WHILE 13/00Z NAM SWEEPS SOME LIGHT PRECIP ACROSS NWRN OK TONIGHT. GIVEN WEAK OVERALL FORCING... WILL STICK WITH THE RADAR/OBS TRENDS. DDC WENT DOWN TO 2 1/2 MILES VIS EARLIER...8-9PM... AS THE BAND SLID THROUGH. OTHER THAN A QUICK DROP IN VIS ACROSS FAR NWRN OK... LITTLE TO NO IMPACTS ARE EXPECTED AS THIS BAND FINALLY DISSIPATES IN 2-3HRS. JTK PREV DISCUSSION... /ISSUED 758 PM CST WED NOV 12 2014/ UPDATE... LOWERED MIN TEMPS IN THE NORTHWEST. INCREASED CLOUD COVER OVERNIGHT. ADJUSTED WINDS TO MORE ACCURATELY REFLECT CURRENT OBSERVATIONS. DISCUSSION... TEMPERATURES IN THE NORTHWEST WERE DROPPING FASTER THAN PREVIOUSLY FORECAST. THE HRRR SHOWS TEMPS IN THAT REGION FALLING INTO THE LOWER TEENS. SKIES ARE CURRENTLY OVERCAST...AND CLOUDS ARE NOT EXPECTED TO BREAK ANY TIME SOON. GUSTY WINDS ARE STILL HOLDING ON...BUT ARE STILL EXPECTED TO DIE DOWN LATER TONIGHT. PREV DISCUSSION... /ISSUED 250 PM CST WED NOV 12 2014/ DISCUSSION... ARCTIC AIR WILL REMAIN IN PLACE OVER THE NEXT FEW DAYS AS A POLAR HIGH SLOWLY SETTLES INTO THE CENTRAL AND SOUTHERN PLAINS. A COMPACT UPPER WAVE HAS LEAD TO WIDESPREAD CLOUDS AND EVEN A FEW SNOW SHOWERS OVER PARTS OF THE TX PANHANDLE/SOUTHWEST OK THIS AFTERNOON. A FEW SNOW FLURRIES MAY FALL IN ISOLATED AREAS THROUGH TONIGHT...BUT NO SIGNIFICANT IMPACTS ARE EXPECTED. COLD WEATHER WILL PREVAIL THROUGH THE COMING WEEKEND. THIS MAY SET THE STAGE FOR OUR FIRST TASTE OF WINTRY PRECIPITATION AS A SERIES OF UPPER LEVEL STORMS MOVE ACROSS THE SOUTHERN PLAINS WITHIN A PERSISTENT COLD AIRMASS. THE FIRST SYSTEM WILL AFFECT THE REGION DURING THE DAY ON SATURDAY. SNOW OR A MIXTURE OF RAIN AND SNOW MAY OCCUR OVER NORTHERN OKLAHOMA EARLY SATURDAY...WITH RAIN ELSEWHERE. SOUTHERLY FLOW AND MID-LEVEL DRY AIR SHOULD ALLOW HIGHS TO ECLIPSE FREEZING OVER MUCH OF THE AREA BY NOON SATURDAY...RESULTING IN A TRANSITION TO MAINLY RAIN MUCH OF SATURDAY AFTERNOON AND EVENING...AND LITTLE IF ANY ACCUMULATION OF FROZEN PRECIPITATION IS EXPECTED SATURDAY. A SECOND MORE POTENT STORM WILL ARRIVE SATURDAY NIGHT AND SUNDAY ON THE HEELS OF A SECOND SHOT OF ARCTIC AIR. AS THE FRONT SHIFTS SOUTHWARD...A DEEP COLD AIRMASS WILL SETTLE INTO THE PLAINS. AS FRONTOGENETIC FORCING INCREASES SUNDAY AND SUNDAY AFTERNOON...ONE OR MORE BANDS OF LIGHT TO MODERATE SNOW MAY DEVELOP AND MOVE FROM NORTHWEST TO SOUTHEAST ACROSS NORTHERN AND CENTRAL OKLAHOMA THROUGH SUNDAY NIGHT. LIGHT SNOW ACCUMULATIONS APPEAR LIKELY...MAINLY OVER NORTHERN AND WESTERN OKLAHOMA. LOCALIZED AREAS MAY PICK UP AN INCH OR MORE OF SNOW SUNDAY INTO SUNDAY NIGHT...RESULTING IN SLICK AND HAZARDOUS ROADS IN SOME AREAS. HEADING INTO NEXT WEEK...VERY COLD AND DRY AIR WILL REMAIN IN PLACE...WITH HIGHS GENERALLY IN THE 30S AND LOWS IN THE TEENS AND 20S. THIS WILL MAKE SNOW/ICE MELT FAIRLY SLOW FOR AREAS THAT SEE MEASURABLE SNOWFALL OVER THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 33 19 39 27 / 0 0 0 10 HOBART OK 33 18 39 28 / 0 0 0 20 WICHITA FALLS TX 36 21 43 30 / 0 0 0 10 GAGE OK 27 13 36 24 / 0 0 0 30 PONCA CITY OK 32 16 36 25 / 0 0 0 10 DURANT OK 37 22 41 27 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1015 PM EST FRI NOV 14 2014 .SYNOPSIS... THE ANOMALOUS UPPER TROUGH WILL BRIEFLY LIFT OUT OVER THE WEEKEND AS SURFACE HIGH PRESSURE SLIDES BY JUST TO THE SOUTH OF PENNSYLVANIA. AN EVEN DEEPER TROUGH WILL FORM OVER THE GREAT LAKES AND NORTHEAST CONUS EARLY NEXT WEEK. THIS DEEPENING TROUGH WILL HELP TO FORM A FAST MOVING AREA OF LOW PRESSURE THAT WILL TRACK FROM THE DEEP SOUTH TO THE SOUTHERN NEW ENGLAND COAST BY MONDAY EVENING. THIS WEATHER FEATURE WILL BRING A LIKELIHOOD OF A LIGHT TO MODERATE SNOWFALL MONDAY ACROSS AT LEAST THE NORTHWEST HALF OF PENNSYLVANIA. MIXED PRECIPITATION AND RAIN ARE MOST LIKELY OVER THE CENTRAL AND SOUTHEAST ON MONDAY. && .NEAR TERM /UNTIL 7 AM SATURDAY MORNING/... 10 PM UPDATE... SNOW SHOWERS ARE STILL MAINLY CELLULAR IN ONLY SEMI-CONCENTRATED BANDS. CELLS MOVING VERY QUICKLY AND CIGS GET HIGH PRETTY QUICKLY AWAY FROM THE LAKE. EVEN KERI IS HIGH-MVFR WHEN IT DOES SNOW THERE. THUS...ACCUMS FOR THE OVERNIGHT LOOK ON TRACK. AS EARLIER...HRRR AND RAP HANDLING THE NEAR-TERM WAGGLE TO THE SOUTH OF THE BROAD BANDS. THEY AND THE NEWEST NAM CONTINUE TO SINK THE BANDS SOUTHWARD FOR A FEW MORE HOURS...THEN STALL FOR A FEW HOURS AND SHOVE THEM BACK TO THE NORTH AS THE CENTER OF THE BIG SFC HIGH MOVES INTO THE CENTRAL APPALACHIANS. 730 PM UPDATE... HRRR AND RUC HANDLING THE SHIFT OF THE BANDS TO THE SOUTH WITH VEERING LOW LEVEL WINDS VERY NICELY. THE NEAR TERM PREDICTIONS PORTRAY THE CONTINUED VEERING THROUGH MIDNIGHT OR A LITTLE LATER...THEN A TURN AROUND AND BACKING TO A GENERALLY SWRLY FLOW IN THE CLOUD LAYER BY SUNRISE. THUS...HAVE HIGH CONFIDENCE IN KEEPING ALL THE WEATHER ELEMENTS VERY CLOSE TO CURRENT PROJECTIONS. LES ADVY STILL LOOKING GOOD FOR WARREN CO. PREV... A PERSISTENT...COLD NORTHWESTERLY FLOW OVR THE GRT LKS WILL CONTINUE TO PRODUCE FREQUENT SNOW SHOWERS ACROSS THE NW MTNS AND LAUREL HIGHLANDS TONIGHT WITH ADDITIONAL LIGHT ACCUMULATIONS OF A COATING TO ONE INCH ACROSS MANY AREAS NEAR...AND JUST TO THE WEST OF RT 219. HIGH RES MODELS SHOW DIRECTIONAL SHEAR IN THE LOWEST FEW KM BECOMING BETTER ALIGNED LATE THIS AFTERNOON THROUGH MUCH OF TONIGHT...WHICH WILL CREATE 2 OR 3...MORE ORGANIZED LES BANDS /THAT WILL PENETRATE FURTHER INLAND THANKS TO A MEAN 20KT FLOW FROM 300 DEG IN THE LOWEST 2 KM/. BRIEF PERIODS OF 1/4-1/2SM SNOW WILL OCCUR WITHIN THESE BANDS. EXTENDED THE LES ADVISORY FOR WARREN COUNTY THROUGH 12Z SATURDAY AS THE PASSAGE OF A WEAK UPPER SHORT WAVE AND SFC TROUGH WILL LEAD TO A BETTER UPSTREAM MOISTURE TAP OFF SOUTHERN LAKE HURON. AREAS OF MORE SHALLOW BKN-OVC STRATO CU ACROSS THE NORTH-CENTRAL MTNS AND CENTRAL RIDGE AND VALLEY REGION /INCLUDING THE SUSQ VALLEY/ WILL SUPPORT MAINLY FLURRIES AN PERHAPS A BRIEF 2-3SM VSBY SNOW SHOWER LATE TODAY AND TONIGHT WITH A FEW LOCATIONS SEEING A POWDERY DUSTING OF SNOW. MIN TEMPS EARLY SATURDAY WILL BE IN THE LOWER TO MID 20S...BUT THE WEST TO NORTHWEST BREEZE WILL DECREASE TO ABOUT 6-8 KTS AFTER 02Z SAT. && .SHORT TERM /7 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... EXPECT ANY REMAINING LAKE EFFECT SNOW BANDS TO SHIFT QUICKLY NORTH OR DISSIPATE DURING LATE MORNING/EARLY AFTERNOON HOURS AS SHEAR WITHIN THE SFC-800 INCREASES...BEFORE THE MEAN WIND IN THIS LAYER GRADUALLY BACKS TO THE WEST-SOUTHWEST IN THE AFTERNOON. ACROSS THE CENTRAL AND SERN ZONES...SOME MORNING CLOUDS AND FLURRIES WILL LIKELY YIELD TO INCREASING AMOUNT OF SUNSHINE THROUGH THE SHALLOW STRATO CU DECK. PARTLY TO MOSTLY CLOUDY SKIES IN THE FORM OF MAINLY ALTO CU CLOUDS EXPECTED FOR SAT NIGHT AS A WARM FRONT LIFTS NE FROM THE OHIO VALLEY. A BIT OF LIGHT SNOW OR FLURRIES IS POSSIBLE SAT NIGHT/EARLY SUNDAY ACROSS THE NW HALF OF THE STATE WITH VERY MINOR ACCUMS AT MOST. MAX TEMPS SAT WILL BE IN THE L-M 30S ACROSS THE NRN AND WRN MTNS...AND UPR 30S TO L40S FURTHER SE THROUGH THE SUSQ VALLEY. LOW TEMPS AT DAYBREAK SUNDAY WILL BE IN THE M-U 20S ACROSS THE MTNS AND 30-35 ELSEWHERE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... COLD WEATHER PATTERN CONTINUES THROUGH NEXT WEEK... ADVISORY LEVEL SNOW ACCUMULATION POSSIBLE ON MONDAY... UPPER LEVEL RIDGING FROM THE NW COAST TO ALASKA WILL SUSTAIN AND MAINTAIN A DEEP TROUGH AND UNSEASONABLY COLD AIRMASS OVER THE AREA THROUGH MUCH OF NEXT WEEK. FORECAST CONFIDENCE REMAINS VERY HIGH IN A PROLONGED STRETCH OF WELL-BELOW NORMAL TEMPERATURES FOR THIS TIME OF YEAR WITH THE CORE OF THE COLD IMPACTING THE CWA TUE-WED. MODELS CONTINUE TO SHOW A LEAD SHORTWAVE CROSSING THE ERN GREAT LAKES ON SUNDAY...WHICH COULD SPREAD SOME LIGHT SNOW/RAIN INTO THE WESTERN COUNTIES DURING THE DAY. RELOADING CENTRAL US TROUGH BECOMES WELL ESTABLISHED BY 12Z MONDAY WITH CORE OF NEGATIVE HEIGHT ANOMALIES /-3 STD/ SPREADING EWD FROM THE UPPER MIDWEST THROUGH THE OH VALLEY. THERE IS AN EMERGING CONSENSUS AMONG THE GLOBAL GUIDANCE IN A BROAD AREA OF PCPN OVERSPREADING THE AREA ON MONDAY...AS MOISTURE AND LIFT BECOME ENHANCED WITHIN THE ENTRANCE REGION OF A STRONG UPPER JET EAST OF THE DEEP TROUGH...ALONG SHARPENING LOW LEVEL THERMAL GRADIENT/FRONTAL AXIS MARKING LEADING EDGE OF ARCTIC AIRMASS. FOLLOWED WPC BLEND FOR QPF AND THERMAL PROFILES WHICH SUPPORTS POTENTIAL FOR ADVISORY LEVEL SNOW ACCUMULATIONS /2-4 INCHES/ OVER THE NW 1/2 OF THE CWA. FURTHER SOUTH/EAST...A RAIN TO SNOW MIX TO CHANGEOVER SCENARIO SEEMS LKLY WITH LOWER ACCUMS GIVEN INITIALLY WARM BLYR. ALTHOUGH THE PTYPE DETAILS AND SNOW ACCUMS ARE STILL UNCERTAIN...CONFIDENCE IN WINTER WEATHER IMPACTS TO THE MONDAY MORNING COMMUTE IS INCREASING ESPECIALLY OVER THE WRN 1/2 OF THE CWA. WILL ADD WORDING INTO THE HWO. A FRIGID SURGE OF ARCTIC AIR WILL BLAST INTO THE REGION BEHIND THIS SYSTEM ON TUESDAY AND PERSIST THRU THE MIDDLE OF NEXT WEEK. MEAN 85H TEMPS ARND -15C IN BOTH THE GEFS/ECENS TRANSLATE INTO HIGH TEMPS BELOW FREEZING FOR MOST OF CENTRAL PA TUE/WED. WIND CHILLS IN THE LOW TEENS AND SINGLE DIGITS ARE LKLY AND MAY EVEN DIP BELOW 0F OVER THE WRN MTNS. THE TRANSITION BACK TO A COLD CYCLONIC NW FLOW PATTERN WILL FAVOR LAKE EFFECT AND TERRAIN ENHANCED SNOW SHOWERS OVER THE NW MTNS WITH COLD AND DRY CONDITIONS FROM THE CENTRAL RIDGES INTO THE LWR SUSQ VLY. SOME MODERATION IN TEMPS MAY BE IN SIGHT BY THE END OF NEXT WEEK AS MODELS AND ENSEMBLES SHOW THE UPSTREAM PATTERN CONFIGURATION BREAKING DOWN. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... LITTLE CHANGE IS EXPECTED ACRS THE REGION TONIGHT AS COLD AIR RIDING SOUTHEAST ACROSS THE RELATIVELY WARMER WATERS OF THE GREAT LAKES IS LIFTED OVER THE HIGHER TERRAIN IN WESTERN PA. THIS SHOULD PRODUCE A LARGE AREA OF MVFR REDUCTIONS WITH SCT IFR CONDITIONS IN MEANDERING BANDS OF SNOW SHOWERS FROM NEAR KBFD- KJST TO AOO. VFR TO HIGH-END MVFR STRATOCU AND SCT LIGHT SNOW SHOWERS/FLURRIES WILL SPILL INTO CENTRAL MTNS AND SUSQ LATE TODAY AND TONIGHT. WINDS WILL SETTLE TO 6-8 KTS TONIGHT. OUTLOOK... SAT...AM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SUN...SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD. MON...LGT-MDT SNOW/LOW CIGS EXPECTED ACROSS THE NW HALF OF PA. RAIN/MIXED PRECIP AND LOW CIGS POSS SE. TUE AND WED...BLUSTERY AND VERY COLD WITH SNOW SHOWERS AND AREAS OF REDUCED CIGS/VSBYS - MAINLY ACROSS THE NW HALF OF PENN. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SATURDAY FOR PAZ004. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
813 PM EST FRI NOV 14 2014 .SYNOPSIS... THE ANOMALOUS UPPER TROUGH WILL BRIEFLY LIFT OUT OVER THE WEEKEND AS SURFACE HIGH PRESSURE SLIDES BY JUST TO THE SOUTH OF PENNSYLVANIA. AN EVEN DEEPER TROUGH WILL FORM OVER THE GREAT LAKES AND NORTHEAST CONUS EARLY NEXT WEEK. THIS DEEPENING TROUGH WILL HELP TO FORM A FAST MOVING AREA OF LOW PRESSURE THAT WILL TRACK FROM THE DEEP SOUTH TO THE SOUTHERN NEW ENGLAND COAST BY MONDAY EVENING. THIS WEATHER FEATURE WILL BRING A LIKELIHOOD OF A LIGHT TO MODERATE SNOWFALL MONDAY ACROSS AT LEAST THE NORTHWEST HALF OF PENNSYLVANIA. MIXED PRECIPITATION AND RAIN ARE MOST LIKELY OVER THE CENTRAL AND SOUTHEAST ON MONDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 730 PM UPDATE... HRRR AND RUC HANDLING THE SHIFT OF THE BANDS TO THE SOUTH WITH VEERING LOW LEVEL WINDS VERY NICELY. THE NEAR TERM PREDICTIONS PORTRAY THE CONTINUED VEERING THROUGH MIDNIGHT OR A LITTLE LATER...THEN A TURN AROUND AND BACKING TO A GENERALLY SWRLY FLOW IN THE CLOUD LAYER BY SUNRISE. THUS...HAVE HIGH CONFIDENCE IN KEEPING ALL THE WEATHER ELEMENTS VERY CLOSE TO CURRENT PROJECTIONS. LES ADVY STILL LOOKING GOOD FOR WARREN CO. PREV... A PERSISTENT...COLD NORTHWESTERLY FLOW OVR THE GRT LKS WILL CONTINUE TO PRODUCE FREQUENT SNOW SHOWERS ACROSS THE NW MTNS AND LAUREL HIGHLANDS TONIGHT WITH ADDITIONAL LIGHT ACCUMULATIONS OF A COATING TO ONE INCH ACROSS MANY AREAS NEAR...AND JUST TO THE WEST OF RT 219. HIGH RES MODELS SHOW DIRECTIONAL SHEAR IN THE LOWEST FEW KM BECOMING BETTER ALIGNED LATE THIS AFTERNOON THROUGH MUCH OF TONIGHT...WHICH WILL CREATE 2 OR 3...MORE ORGANIZED LES BANDS /THAT WILL PENETRATE FURTHER INLAND THANKS TO A MEAN 20KT FLOW FROM 300 DEG IN THE LOWEST 2 KM/. BRIEF PERIODS OF 1/4-1/2SM SNOW WILL OCCUR WITHIN THESE BANDS. EXTENDED THE LES ADVISORY FOR WARREN COUNTY THROUGH 12Z SATURDAY AS THE PASSAGE OF A WEAK UPPER SHORT WAVE AND SFC TROUGH WILL LEAD TO A BETTER UPSTREAM MOISTURE TAP OFF SOUTHERN LAKE HURON. AREAS OF MORE SHALLOW BKN-OVC STRATO CU ACROSS THE NORTH-CENTRAL MTNS AND CENTRAL RIDGE AND VALLEY REGION /INCLUDING THE SUSQ VALLEY/ WILL SUPPORT MAINLY FLURRIES AN PERHAPS A BRIEF 2-3SM VSBY SNOW SHOWER LATE TODAY AND TONIGHT WITH A FEW LOCATIONS SEEING A POWDERY DUSTING OF SNOW. MIN TEMPS EARLY SATURDAY WILL BE IN THE LOWER TO MID 20S...BUT THE WEST TO NORTHWEST BREEZE WILL DECREASE TO ABOUT 6-8 KTS AFTER 02Z SAT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... EXPECT ANY REMAINING LAKE EFFECT SNOW BANDS TO SHIFT QUICKLY NORTH OR DISSIPATE DURING LATE MORNING/EARLY AFTERNOON HOURS AS SHEAR WITHIN THE SFC-800 INCREASES...BEFORE THE MEAN WIND IN THIS LAYER GRADUALLY BACKS TO THE WEST-SOUTHWEST IN THE AFTERNOON. ACROSS THE CENTRAL AND SERN ZONES...SOME MORNING CLOUDS AND FLURRIES WILL LIKELY YIELD TO INCREASING AMOUNT OF SUNSHINE THROUGH THE SHALLOW STRATO CU DECK. PARTLY TO MOSTLY CLOUDY SKIES IN THE FORM OF MAINLY ALTO CU CLOUDS EXPECTED FOR SAT NIGHT AS A WARM FRONT LIFTS NE FROM THE OHIO VALLEY. A BIT OF LIGHT SNOW OR FLURRIES IS POSSIBLE SAT NIGHT/EARLY SUNDAY ACROSS THE NW HALF OF THE STATE WITH VERY MINOR ACCUMS AT MOST. MAX TEMPS SAT WILL BE IN THE L-M 30S ACROSS THE NRN AND WRN MTNS...AND UPR 30S TO L40S FURTHER SE THROUGH THE SUSQ VALLEY. LOW TEMPS AT DAYBREAK SUNDAY WILL BE IN THE M-U 20S ACROSS THE MTNS AND 30-35 ELSEWHERE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... COLD WEATHER PATTERN CONTINUES THROUGH NEXT WEEK... ADVISORY LEVEL SNOW ACCUMULATION POSSIBLE ON MONDAY... UPPER LEVEL RIDGING FROM THE NW COAST TO ALASKA WILL SUSTAIN AND MAINTAIN A DEEP TROUGH AND UNSEASONABLY COLD AIRMASS OVER THE AREA THROUGH MUCH OF NEXT WEEK. FORECAST CONFIDENCE REMAINS VERY HIGH IN A PROLONGED STRETCH OF WELL-BELOW NORMAL TEMPERATURES FOR THIS TIME OF YEAR WITH THE CORE OF THE COLD IMPACTING THE CWA TUE-WED. MODELS CONTINUE TO SHOW A LEAD SHORTWAVE CROSSING THE ERN GREAT LAKES ON SUNDAY...WHICH COULD SPREAD SOME LIGHT SNOW/RAIN INTO THE WESTERN COUNTIES DURING THE DAY. RELOADING CENTRAL US TROUGH BECOMES WELL ESTABLISHED BY 12Z MONDAY WITH CORE OF NEGATIVE HEIGHT ANOMALIES /-3 STD/ SPREADING EWD FROM THE UPPER MIDWEST THROUGH THE OH VALLEY. THERE IS AN EMERGING CONSENSUS AMONG THE GLOBAL GUIDANCE IN A BROAD AREA OF PCPN OVERSPREADING THE AREA ON MONDAY...AS MOISTURE AND LIFT BECOME ENHANCED WITHIN THE ENTRANCE REGION OF A STRONG UPPER JET EAST OF THE DEEP TROUGH...ALONG SHARPENING LOW LEVEL THERMAL GRADIENT/FRONTAL AXIS MARKING LEADING EDGE OF ARCTIC AIRMASS. FOLLOWED WPC BLEND FOR QPF AND THERMAL PROFILES WHICH SUPPORTS POTENTIAL FOR ADVISORY LEVEL SNOW ACCUMULATIONS /2-4 INCHES/ OVER THE NW 1/2 OF THE CWA. FURTHER SOUTH/EAST...A RAIN TO SNOW MIX TO CHANGEOVER SCENARIO SEEMS LKLY WITH LOWER ACCUMS GIVEN INITIALLY WARM BLYR. ALTHOUGH THE PTYPE DETAILS AND SNOW ACCUMS ARE STILL UNCERTAIN...CONFIDENCE IN WINTER WEATHER IMPACTS TO THE MONDAY MORNING COMMUTE IS INCREASING ESPECIALLY OVER THE WRN 1/2 OF THE CWA. WILL ADD WORDING INTO THE HWO. A FRIGID SURGE OF ARCTIC AIR WILL BLAST INTO THE REGION BEHIND THIS SYSTEM ON TUESDAY AND PERSIST THRU THE MIDDLE OF NEXT WEEK. MEAN 85H TEMPS ARND -15C IN BOTH THE GEFS/ECENS TRANSLATE INTO HIGH TEMPS BELOW FREEZING FOR MOST OF CENTRAL PA TUE/WED. WIND CHILLS IN THE LOW TEENS AND SINGLE DIGITS ARE LKLY AND MAY EVEN DIP BELOW 0F OVER THE WRN MTNS. THE TRANSITION BACK TO A COLD CYCLONIC NW FLOW PATTERN WILL FAVOR LAKE EFFECT AND TERRAIN ENHANCED SNOW SHOWERS OVER THE NW MTNS WITH COLD AND DRY CONDITIONS FROM THE CENTRAL RIDGES INTO THE LWR SUSQ VLY. SOME MODERATION IN TEMPS MAY BE IN SIGHT BY THE END OF NEXT WEEK AS MODELS AND ENSEMBLES SHOW THE UPSTREAM PATTERN CONFIGURATION BREAKING DOWN. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... LITTLE CHANGE IS EXPECTED ACRS THE REGION TONIGHT AS COLD AIR RIDING SOUTHEAST ACROSS THE RELATIVELY WARMER WATERS OF THE GREAT LAKES IS LIFTED OVER THE HIGHER TERRAIN IN WESTERN PA. THIS SHOULD PRODUCE A LARGE AREA OF MVFR REDUCTIONS WITH SCT IFR CONDITIONS IN MEANDERING BANDS OF SNOW SHOWERS FROM NEAR KBFD- KJST TO AOO. VFR TO HIGH-END MVFR STRATOCU AND SCT LIGHT SNOW SHOWERS/FLURRIES WILL SPILL INTO CENTRAL MTNS AND SUSQ LATE TODAY AND TONIGHT. WINDS WILL SETTLE TO 6-8 KTS TONIGHT. OUTLOOK... SAT...AM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SUN...SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD. MON...LGT-MDT SNOW/LOW CIGS EXPECTED ACROSS THE NW HALF OF PA. RAIN/MIXED PRECIP AND LOW CIGS POSS SE. TUE AND WED...BLUSTERY AND VERY COLD WITH SNOW SHOWERS AND AREAS OF REDUCED CIGS/VSBYS - MAINLY ACROSS THE NW HALF OF PENN. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SATURDAY FOR PAZ004. && $$ SYNOPSIS...LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
736 PM EST FRI NOV 14 2014 .SYNOPSIS... THE ANOMALOUS UPPER TROUGH WILL BRIEFLY LIFT OUT OVER THE WEEKEND AS SURFACE HIGH PRESSURE SLIDES BY JUST TO THE SOUTH OF PENNSYLVANIA. AN EVEN DEEPER TROUGH WILL FORM OVER THE GREAT LAKES AND NORTHEAST CONUS EARLY NEXT WEEK. THIS DEEPENING TROUGH WILL HELP TO FORM A FAST MOVING AREA OF LOW PRESSURE THAT WILL TRACK FROM THE DEEP SOUTH TO THE SOUTHERN NEW ENGLAND COAST BY MONDAY EVENING. THIS WEATHER FEATURE WILL BRING A LIKELIHOOD OF A LIGHT TO MODERATE SNOWFALL MONDAY ACROSS AT LEAST THE NORTHWEST HALF OF PENNSYLVANIA. MIXED PRECIPITATION AND RAIN ARE MOST LIKELY OVER THE CENTRAL AND SOUTHEAST ON MONDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 730 PM UPDATE... HRRR AND RUC HANDLING THE SHIFT OF THE BANDS TO THE SOUTH WITH VEERING LOW LEVEL WINDS VERY NICELY. THE NEAR TERM PREDICTIONS PORTRAY THE CONTINUED VEERING THROUGH MIDNIGHT OR A LITTLE LATER...THEN A TURN AROUND AND BACKING TO A GENERALLY SWRLY FLOW IN THE CLOUD LAYER BY SUNRISE. THUS...HAVE HIGH CONFIDENCE IN KEEPING ALL THE WEATHER ELEMENTS VERY CLOSE TO CURRENT PROJECTIONS. LES ADVY STILL LOOKING GOOD FOR WARREN CO. PREV... A PERSISTENT...COLD NORTHWESTERLY FLOW OVR THE GRT LKS WILL CONTINUE TO PRODUCE FREQUENT SNOW SHOWERS ACROSS THE NW MTNS AND LAUREL HIGHLANDS TONIGHT WITH ADDITIONAL LIGHT ACCUMULATIONS OF A COATING TO ONE INCH ACROSS MANY AREAS NEAR...AND JUST TO THE WEST OF RT 219. HIGH RES MODELS SHOW DIRECTIONAL SHEAR IN THE LOWEST FEW KM BECOMING BETTER ALIGNED LATE THIS AFTERNOON THROUGH MUCH OF TONIGHT...WHICH WILL CREATE 2 OR 3...MORE ORGANIZED LES BANDS /THAT WILL PENETRATE FURTHER INLAND THANKS TO A MEAN 20KT FLOW FROM 300 DEG IN THE LOWEST 2 KM/. BRIEF PERIODS OF 1/4-1/2SM SNOW WILL OCCUR WITHIN THESE BANDS. EXTENDED THE LES ADVISORY FOR WARREN COUNTY THROUGH 12Z SATURDAY AS THE PASSAGE OF A WEAK UPPER SHORT WAVE AND SFC TROUGH WILL LEAD TO A BETTER UPSTREAM MOISTURE TAP OFF SOUTHERN LAKE HURON. AREAS OF MORE SHALLOW BKN-OVC STRATO CU ACROSS THE NORTH-CENTRAL MTNS AND CENTRAL RIDGE AND VALLEY REGION /INCLUDING THE SUSQ VALLEY/ WILL SUPPORT MAINLY FLURRIES AN PERHAPS A BRIEF 2-3SM VSBY SNOW SHOWER LATE TODAY AND TONIGHT WITH A FEW LOCATIONS SEEING A POWDERY DUSTING OF SNOW. MIN TEMPS EARLY SATURDAY WILL BE IN THE LOWER TO MID 20S...BUT THE WEST TO NORTHWEST BREEZE WILL DECREASE TO ABOUT 6-8 KTS AFTER 02Z SAT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... EXPECT ANY REMAINING LAKE EFFECT SNOW BANDS TO SHIFT QUICKLY NORTH OR DISSIPATE DURING LATE MORNING/EARLY AFTERNOON HOURS AS SHEAR WITHIN THE SFC-800 INCREASES...BEFORE THE MEAN WIND IN THIS LAYER GRADUALLY BACKS TO THE WEST-SOUTHWEST IN THE AFTERNOON. ACROSS THE CENTRAL AND SERN ZONES...SOME MORNING CLOUDS AND FLURRIES WILL LIKELY YIELD TO INCREASING AMOUNT OF SUNSHINE THROUGH THE SHALLOW STRATO CU DECK. PARTLY TO MOSTLY CLOUDY SKIES IN THE FORM OF MAINLY ALTO CU CLOUDS EXPECTED FOR SAT NIGHT AS A WARM FRONT LIFTS NE FROM THE OHIO VALLEY. A BIT OF LIGHT SNOW OR FLURRIES IS POSSIBLE SAT NIGHT/EARLY SUNDAY ACROSS THE NW HALF OF THE STATE WITH VERY MINOR ACCUMS AT MOST. MAX TEMPS SAT WILL BE IN THE L-M 30S ACROSS THE NRN AND WRN MTNS...AND UPR 30S TO L40S FURTHER SE THROUGH THE SUSQ VALLEY. LOW TEMPS AT DAYBREAK SUNDAY WILL BE IN THE M-U 20S ACROSS THE MTNS AND 30-35 ELSEWHERE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... COLD WEATHER PATTERN CONTINUES THROUGH NEXT WEEK... ADVISORY LEVEL SNOW ACCUMULATION POSSIBLE ON MONDAY... UPPER LEVEL RIDGING FROM THE NW COAST TO ALASKA WILL SUSTAIN AND MAINTAIN A DEEP TROUGH AND UNSEASONABLY COLD AIRMASS OVER THE AREA THROUGH MUCH OF NEXT WEEK. FORECAST CONFIDENCE REMAINS VERY HIGH IN A PROLONGED STRETCH OF WELL-BELOW NORMAL TEMPERATURES FOR THIS TIME OF YEAR WITH THE CORE OF THE COLD IMPACTING THE CWA TUE-WED. MODELS CONTINUE TO SHOW A LEAD SHORTWAVE CROSSING THE ERN GREAT LAKES ON SUNDAY...WHICH COULD SPREAD SOME LIGHT SNOW/RAIN INTO THE WESTERN COUNTIES DURING THE DAY. RELOADING CENTRAL US TROUGH BECOMES WELL ESTABLISHED BY 12Z MONDAY WITH CORE OF NEGATIVE HEIGHT ANOMALIES /-3 STD/ SPREADING EWD FROM THE UPPER MIDWEST THROUGH THE OH VALLEY. THERE IS AN EMERGING CONSENSUS AMONG THE GLOBAL GUIDANCE IN A BROAD AREA OF PCPN OVERSPREADING THE AREA ON MONDAY...AS MOISTURE AND LIFT BECOME ENHANCED WITHIN THE ENTRANCE REGION OF A STRONG UPPER JET EAST OF THE DEEP TROUGH...ALONG SHARPENING LOW LEVEL THERMAL GRADIENT/FRONTAL AXIS MARKING LEADING EDGE OF ARCTIC AIRMASS. FOLLOWED WPC BLEND FOR QPF AND THERMAL PROFILES WHICH SUPPORTS POTENTIAL FOR ADVISORY LEVEL SNOW ACCUMULATIONS /2-4 INCHES/ OVER THE NW 1/2 OF THE CWA. FURTHER SOUTH/EAST...A RAIN TO SNOW MIX TO CHANGEOVER SCENARIO SEEMS LKLY WITH LOWER ACCUMS GIVEN INITIALLY WARM BLYR. ALTHOUGH THE PTYPE DETAILS AND SNOW ACCUMS ARE STILL UNCERTAIN...CONFIDENCE IN WINTER WEATHER IMPACTS TO THE MONDAY MORNING COMMUTE IS INCREASING ESPECIALLY OVER THE WRN 1/2 OF THE CWA. WILL ADD WORDING INTO THE HWO. A FRIGID SURGE OF ARCTIC AIR WILL BLAST INTO THE REGION BEHIND THIS SYSTEM ON TUESDAY AND PERSIST THRU THE MIDDLE OF NEXT WEEK. MEAN 85H TEMPS ARND -15C IN BOTH THE GEFS/ECENS TRANSLATE INTO HIGH TEMPS BELOW FREEZING FOR MOST OF CENTRAL PA TUE/WED. WIND CHILLS IN THE LOW TEENS AND SINGLE DIGITS ARE LKLY AND MAY EVEN DIP BELOW 0F OVER THE WRN MTNS. THE TRANSITION BACK TO A COLD CYCLONIC NW FLOW PATTERN WILL FAVOR LAKE EFFECT AND TERRAIN ENHANCED SNOW SHOWERS OVER THE NW MTNS WITH COLD AND DRY CONDITIONS FROM THE CENTRAL RIDGES INTO THE LWR SUSQ VLY. SOME MODERATION IN TEMPS MAY BE IN SIGHT BY THE END OF NEXT WEEK AS MODELS AND ENSEMBLES SHOW THE UPSTREAM PATTERN CONFIGURATION BREAKING DOWN. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... LITTLE CHANGE IS EXPECTED ACRS THE REGION LATE TODAY AND TONIGHT AS COLD AIR RIDING SOUTHEAST ACROSS THE RELATIVELY WARMER WATERS OF THE GREAT LAKES IS LIFTED OVER THE HIGHER TERRAIN IN WESTERN PA...PRODUCING A LARGE AREA OF MVFR REDUCTIONS WITH SCT IFR CONDITIONS IN MEANDERING BANDS OF SNOW SHOWERS FROM NEAR KBFD-KJST. VFR TO HIGH-END MVFR STRATOCU AND SCT LIGHT SNOW SHOWERS/FLURRIES WILL SPILL INTO CENTRAL MTNS AND SUSQ LATE TODAY AND TONIGHT. WINDS WILL BE IN THE 10-15 KT RANGE WITH GUSTS UP TO AROUND 20 KTS AT A FEW LOCATIONS THROUGH 23Z. WINDS WILL SETTLE TO 6-8 KTS TONIGHT. OUTLOOK... SAT...AM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SUN...SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD. MON...LGT-MDT SNOW/LOW CIGS EXPECTED ACROSS THE NW HALF OF PA. RAIN/MIXED PRECIP AND LOW CIGS POSS SE. TUE AND WED...BLUSTERY AND VERY COLD WITH SNOW SHOWERS AND AREAS OF REDUCED CIGS/VSBYS - MAINLY ACROSS THE NW HALF OF PENN. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SATURDAY FOR PAZ004. && $$ SYNOPSIS...LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1047 AM EST THU NOV 13 2014 .DISCUSSION... BAND OF SNOW NOW OVER THE NORTHWESTERN PARTS OF THE CWA...BUT LOOKING LIKE THIS WILL NOT PENETRATE TOO FAR INTO OUR AREA...PER LAST FEW HRRR RUNS. WILL LEAVE SOME LIGHT POPS IN THE NORTHEASTERN SECTIONS FOR THIS AFTERNOON AS SOME LIGHT INSTABILITY WILL BE PUSHING INTO THAT AREA DURING THE AFTERNOON. WILL HAVE AT LEAST THE MENTION OF SPRINKLES FOLLOWED BY FLURRIES OVER THE NORTHERN HALF OF THE AREA. DRIER AIR WILL BE PUSHING INTO THE AREA AND SHOULD END ANY REMAINING DRIZZLE. TEMPERATURE FORECAST IS ON TRACK. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 44 25 42 25 / 10 0 10 10 KNOXVILLE MCGHEE TYSON AIRPORT, TN 42 23 39 23 / 10 10 10 10 OAK RIDGE, TN 42 23 38 23 / 10 10 10 10 TRI CITIES AIRPORT, TN 44 24 34 19 / 20 10 10 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ GM
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1112 PM CST WED NOV 12 2014 .AVIATION... VFR CONDITIONS WILL PREVAIL WITH BREEZY NORTHERLY WINDS CONTINUING THROUGH TOMORROW AFTERNOON. SPEEDS WILL FINALLY DECREASE TOMORROW EVENING AS SKIES BECOME MOSTLY CLEAR. VERY SMALL CHANCE FOR A PASSING SHOWER TONIGHT...PROBABILITIES ARE TOO LOW TO MENTION IN THE TAFS. HAMPSHIRE && .PREV DISCUSSION... /ISSUED 959 PM CST WED NOV 12 2014/ UPDATE... RADAR ECHOES CONTINUE ACROSS OUR AREA WITH CURRENT TEMPS IN THE MID 30S ACROSS THE HILL COUNTRY. THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS AS THE LATEST HRRR HIRES SOLUTION MODEL SUGGEST. THEREFORE...WILL GO WITH A SLIGHT CHANCE FOR COLD/FREEZING RAIN LATE TONIGHT AS TEMPS REACH THE 32 DEGREE MARK. NO ACCUMULATION EXPECTED. UPDATED ZONES OUT SHORTLY. PREV DISCUSSION... /ISSUED 755 PM CST WED NOV 12 2014/ UPDATE... AN UPPER LEVEL DISTURBANCE MOVING NORTHEASTWARD ACROSS THE RIO GRANDE IS HELPING FOR LIGHT RAIN TO FORM OVER THE SOUTHERN COUNTIES. LATEST HRRR SHOWS LIGHT RAIN OVER THAT AREA TO ABOUT MIDNIGHT BEFORE SHIFTING TO THE EAST AND AWAY OF THE REGION. WILL ADD A SLIGHT CHANCE FOR LIGHT RAIN MAINLY ALONG AND EAST OF PEARSALL TO SEGUIN TO SCHULENBURG LINE TO MIDNIGHT TONIGHT. UPDATED ZONES OUT SHORTLY. PREV DISCUSSION... /ISSUED 504 PM CST WED NOV 12 2014/ AVIATION... VFR CLOUD DECK REMAINS IN PLACE ACROSS ALL TAF SITES AND THIS WILL CONTINUE FOR THE NEXT 20-24 HOURS BEFORE SKIES FINALLY BEGIN TO CLEAR. CIGS WILL LOWER OVERNIGHT FOR THE I-35 TAF SITES TO AROUND 5KFT AS A WEAK MID-LEVEL DISTURBANCE MOVES INTO THE AREA FROM THE WEST. THE LOW-LEVELS OF THE ATMOSPHERE WILL BE MUCH TOO DRY FOR ANY PRECIP. OTHERWISE...BREEZY NORTHERLY FLOW SHOULD CONTINUE THROUGH THE PERIOD. HAMPSHIRE PREV DISCUSSION... /ISSUED 341 PM CST WED NOV 12 2014/ SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... WEAK ISENTROPIC LIFT AHEAD OF AN APPROACHING SHORTWAVE HAS ALLOWED A LOW CLOUD DECK TO MOVE BACK OVER MUCH OF SOUTH CENTRAL TEXAS TODAY. EARLIER NAM AND HI-RES MODEL RUNS HAD INDICATED SOME PRECIPITATION FOR TONIGHT. HOWEVER...LATEST RUNS NO LONGER SHOW IT. THIS IS REASONABLE AS MOISTURE DEPTH IS SHALLOW AND SUFFICIENT FOR ONLY CLOUD FORMATION AND MAINTENANCE. EVEN THOUGH CLOUDS PERSIST OVERNIGHT INTO THURSDAY MORNING...COLD ADVECTION CONTINUES AND ALLOWS FOR SLIGHTLY MORE WIDESPREAD FREEZING TEMPERATURES FOR TONIGHT INTO THURSDAY MORNING ACROSS THE HILL COUNTRY AND AREAS ALONG THE ESCARPMENT WEST OF I-35. MANY AREAS OF THE HILL COUNTRY THAT STAYED ABOVE FREEZING LAST NIGHT INTO THIS MORNING WILL FALL BELOW FREEZING BY THURSDAY MORNING. THE FEW SPOTS THAT STAYED ABOVE FREEZING IN GILLESPIE AND KERR COUNTIES WILL FALL BELOW FREEZING BY THURSDAY MORNING. AREAS ALONG THE ESCARPMENT WEST OF I-35 IN HAYS...TRAVIS AND WILLIAMSON COUNTIES WILL HAVE FREEZING TEMPERATURES FOR 2 TO 3 HOURS AROUND SUNRISE THURSDAY. HOWEVER... THE AUSTIN METRO AREA WILL REMAIN JUST ABOVE FREEZING. ISENTROPIC LIFT WANES ON THURSDAY AS THE SHORTWAVE MOVES EAST OF TEXAS RESULTING IN DECREASING CLOUDS. TEMPERATURES WILL WARM ONLY ABOUT 10 DEGREES OR SO DURING THE DAY DUE CLOUDS LINGERING IN THE MORNING AND CONTINUED COLD ADVECTION. SKIES BECOME CLEAR TO PARTLY CLOUDY AND COMBINED WITH DECREASING WINDS WILL ALLOW FOR A WIDESPREAD FREEZE ACROSS SOUTH CENTRAL TEXAS THURSDAY NIGHT INTO FRIDAY MORNING. A FREEZE WARNING WILL LIKELY BE ISSUED FOR THE REMAINDER OF SOUTH CENTRAL TEXAS FOR THURSDAY NIGHT INTO FRIDAY MORNING IN LATER FORECASTS. LONG TERM (FRIDAY THROUGH WEDNESDAY)... AN UPPER LEVEL TROUGH MOVES ACROSS TEXAS SATURDAY WHILE A SURFACE TROUGH MOVES TO THE NORTHEAST ACROSS THE TEXAS COASTAL WATERS. ISENTROPIC LIFT DEVELOPS FRIDAY NIGHT LEADING TO SLIGHT CHANCE TO CHANCE OF RAIN SATURDAY INTO SATURDAY NIGHT EAST OF HIGHWAY 281 AND I-35. A WARM ADVECTION PATTERN WILL KEEP TEMPERATURES ABOVE FREEZING FRIDAY NIGHT INTO SATURDAY NIGHT. A COLD FRONT MOVES ACROSS TEXAS SUNDAY WHILE ANOTHER UPPER LEVEL TROUGH MOVES ACROSS THE SOUTHERN PLAINS BY EARLY MONDAY. ISENTROPIC LIFT BECOMES MORE WIDESPREAD WITH SLIGHT CHANCES OF RAIN SPREADING TO ALL OF SOUTH CENTRAL TEXAS SUNDAY NIGHT. THE TROUGH MOVES OFF TO THE EAST ENDING RAIN CHANCES LATE SUNDAY NIGHT BEFORE SOME FREEZING TEMPERATURES OCCUR EARLY MONDAY MORNING. MORE WIDESPREAD FREEZING TEMPERATURES ARE EXPECTED MONDAY NIGHT INTO TUESDAY MORNING. FLOW OFF THE GULF RETURNS WITH WARMER TEMPERATURES BY NEXT WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 34 44 30 48 37 / 10 - - - 10 AUSTIN BERGSTROM INTL AIRPORT 33 45 27 49 35 / 10 - - - 10 NEW BRAUNFELS MUNI AIRPORT 33 46 29 51 37 / 10 - - - 10 BURNET MUNI AIRPORT 30 41 27 48 34 / 10 - - - - DEL RIO INTL AIRPORT 34 47 31 52 38 / 20 - - - - GEORGETOWN MUNI AIRPORT 31 42 27 48 35 / 10 - - - - HONDO MUNI AIRPORT 33 47 27 50 35 / 10 - - - - SAN MARCOS MUNI AIRPORT 33 45 29 49 36 / 10 - - - 10 LA GRANGE - FAYETTE REGIONAL 34 45 30 50 38 / 10 10 - - 10 SAN ANTONIO INTL AIRPORT 35 47 30 51 39 / 10 - - - 10 STINSON MUNI AIRPORT 36 48 31 51 39 / 20 - - - 10 && .EWX WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 10 AM CST THURSDAY FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...GILLESPIE...HAYS...KENDALL... KERR...LLANO...REAL...TRAVIS...VAL VERDE...WILLIAMSON. && $$ MESOSCALE/AVIATION...29 SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
254 PM EST THU NOV 13 2014 .SYNOPSIS... A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT AND DEEPEN OFF THE NEW ENGLAND COAST ON FRIDAY. ARCTIC HIGH PRESSURE WILL BUILD INTO THE REGION INTO AND THROUGH SATURDAY. OUR NEXT POTENTIAL WEATHER MAKER MOVES ACROSS THE AREA SUNDAY THROUGH MONDAY WITH GUSTY WINDS AND COLD TEMPERATURES BEHIND IT ON TUESDAY. && .NEAR TERM /THROUGH FRIDAY/... AS OF 245 PM EST THURSDAY... THROUGH THIS EVENING...OUR FOCUS WILL BE A REGION OF INSENTROPIC LIFT THAT WILL HAVE THE CENTER OF ITS FORCING SHIFT EASTWARD ACROSS THE REGION. CURRENTLY PRECIPITATION ASSOCIATED WITH IT IS EXTENDING FROM WESTERN MARYLAND SOUTHWEST INTO EASTERN KENTUCKY AND TENNESSEE. FROM ROUGHLY LONESOME PINE VIRGINIA AND POINTS NORTH...THE PRECIPITATION WAS IN THE FORM OF VERY LIGHT SNOW. POINTS SOUTH INTO EASTERN TENNESSEE HAD LIGHT RAIN. REGIONAL RADAR TRENDS AND OUTPUT FROM THE MESOSCALE HRRR AND RNK WRF-ARW MODELS SUGGEST THE FOLLOWING PROGRESSION WITHIN THE PRECIPITATION THIS EVENING. THE PRECIPITATION SLOWLY CONTINUES ITS PROGRESSION INTO THE WESTERN PORTION OF THE FORECAST AREA THROUGH ROUGHLY 600 PM. AFTER 7 OR 8 PM...THE FOCUS SHIFTS TO NEAR THE CREST OF THE BLUE RIDGE FROM ROUGHLY ROANOKE VA AND POINTS NORTH...AND THEN FARTHER EASTWARD TOWARDS BUCKINGHAM BY 1 OR 2 AM. THE PRECIPITATION TYPE WILL BE MAINLY LIGHT RAIN OR LIGHT SNOW WITH A TRANSITION FROM WEST TO EAST AS THE EVENING PROGRESSES. MOST AREAS WILL RECEIVE NO MEASURABLE PRECIPITATION. ELEVATED SURFACES IN THE WEST AND NORTH MAY BE ABLE TO GET A LIGHT COATING OF SNOW. WHILE NOT EXPECTED AT ALL LOCATIONS...THERE IS A POTENTIAL FOR A BRIEF PERIOD OF SLEET DURING THE TRANSITION FROM LIGHT RAIN TO LIGHT SNOW. AS OUR ENERGY FROM THIS EVENING SHIFTS TO THE COAST...IT WILL TEAM UP WITH ANOTHER SYSTEM THAT HAS BEEN HUGGING THE COAST DURING THE COURSE OF TODAY. THIS MERGER AND DEEPENING WILL HELP STRENGTHEN THE PRESSURE GRADIENT ACROSS THE AREA...AND THUS THE MAGNITUDE OF THE NORTHWEST FLOW COLD AIR ADVECTION. IT WILL BE THIS TIME WHERE OUR REALLY GOOD SURGE OF COLDER AIR COMMENCES ACROSS THE REGION. LOWS TONIGHT WILL RANGE FROM THE UPPER TEENS TO LOWER 20S ACROSS THE MOUNTAINS WITH UPPER 20S TO LOWER 30S ACROSS THE PIEDMONT. ON FRIDAY...NORTHWEST FLOW WILL CONTINUE AND HELP MAINTAIN UPSLOPE CLOUDS ACROSS THE MOUNTAINS THROUGH AT LEAST MIDDAY. IN THE EAST...THE CLOUD COVER WILL CLEAR EARLY GIVEN A DECENT DOWNSLOPE COMPONENT. DRIER AIR WILL EVENTUALLY WIN OUT IN THE MOUNTAINS TOO...WITH MOST REGIONS AT LEAST MOSTLY SUNNY BY THE LATE AFTERNOON. HIGH TEMPERATURES WILL RANGE FROM THE LOW TO MID 30S ACROSS THE MOUNTAINS WITH READINGS AROUND 40 TO THE LOWER 40S ACROSS THE PIEDMONT. SOME OF THE FORECAST HIGHS...ESPECIALLY THOSE IN THE WEST...ARE ONLY EXPECTED TO BE A COUPLE OF DEGREES ABOVE THE RECORD LOW MAXIMUMS FOR THE DAY. SPECIFIC LOW MAXIMUM RECORDS FOR FRIDAY AND SATURDAY ARE IN THE CLIMATE SECTION OF THIS DISCUSSION. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... AS OF 205 PM EST THURSDAY... COLD HIGH PRESSURE WILL SLIDE EAST ACROSS THE AREA FRIDAY NIGHT AND BE ABOUT OVERHEAD BY SATURDAY MORNING. THIS WILL BRING CLEAR SKIES UNDER STRONG SUBSIDENCE ALONG WITH VERY COLD EARLY MORNING TEMPS SATURDAY AS THE CORE OF THE COLDEST 85H SETTLES OVERHEAD. THIS ALONG WITH GREAT RADIATIONAL COOLING SUPPORTS LOWS IN THE TEENS WEST TO LOW/MID 20S EAST. RIDGING SHIFTS SLOWLY EAST DURING SATURDAY BUT SHOULD HANG ON LONG ENOUGH TO KEEP THINGS MOSTLY SUNNY BUT STILL ON THE COLD SIDE WITH ONLY ABOUT A 3-5+ DEGREE RISE IN 85H TEMPS. HOWEVER EVEN WITH SOME SLIGHT WARMING ALOFT INFLUX OF HIGH LEVEL CLOUDS MAY HOLD TEMPS SLIGHTLY BELOW MOS...MAINLY 38-45. MID LEVEL RIDGING STARTS TO BREAK DOWN SATURDAY NIGHT INTO SUNDAY AS A DEVELOPING 5H TROUGH STARTS TO APPROACH FROM THE WEST. ONSET OF BETTER MID/HIGH LEVEL MOISTURE LIKELY TO BRING INCREASING CLOUDS SATURDAY NIGHT BUT LIKELY THIN ENOUGH EARLY ON TO ALLOW TEMPS TO DIP INTO THE 20S MOST SPOTS BUT STILL DRY. SYSTEM HEADS EAST TOWARD THE REGION BUT QUITE DISORGANIZED INITIALLY WITH NORTHERN STREAM ENERGY PASSING TO THE NW AND THE MAIN SOUTHERN STREAM WAVE STILL HANGING BACK ALONG THE GULF COAST. SOME SOLUTIONS SUCH AS THE GFS REMAIN FAST TO BRING SOME LEAD LIGHT PRECIP NE INTO THE AREA ON SUNDAY WHILE OTHERS PER THE LATEST ECMWF QUITE SLOW WITH LITTLE PRECIP AT ALL DURING THE DAY. GIVEN THE STRONG UPPER JET AND PAST HISTORY OF WEAK LIFT SYSTEMS DEVELOPING PRECIP FASTER...LEFT IN SOME CHANCE POPS SUNDAY AFTERNOON WITH SOME LIGHT SNOW...MAINLY FAR NW WHERE A NAM/GFS MIX WOULD SUPPORT A MORE FROZEN SCENARIO. TEMPS TO WARM A BIT UNDER WARM ADVECTION ALOFT IN ADVANCE OF THE INITIAL FRONT WITH HIGHS MOSTLY 40S EXCEPT LOW 50S SE. DIGGING/AMPLIFYING 5H TROUGH WILL START TO ARRIVE FROM THE NW LATER SUNDAY NIGHT AND HELP ENHANCE MOISTURE COMING NE WITH THE SOUTHERN SHORTWAVE. HOWEVER JUST HOW FAST THIS HAPPENS KEY TO PRECIP COVERAGE SUNDAY NIGHT AS WELL AS THE TEMP PROFILE ALOFT GIVEN DECENT 85H WARM ADVECTION. LATEST GFS FASTER BUT STILL HAS BEST LIFT CLOSER TO THE BAROCLINIC ZONE ALONG THE APPALACHIANS AS WEAK SURFACE WAVES LIFT NE INTO THE CAROLINAS LATE. NEW ECMWF MUCH SLOWER WITH THE SOUTHERN SYSTEM LAGGING FARTHER SOUTH WHICH WOULD RESULT IN ONLY SPOTTY PRECIP. FOR NOW KEPT LIKELY POPS FOR LATER SUNDAY NIGHT BUT WARMER WITH PERHAPS ONLY THE HIGHER ELEVATIONS OVER THE FAR NW STAYING COLD ENOUGH ALOFT FOR SNOW. OTRW LOWS STEADYING OUT IN THE 30S WEST TO AROUND 40 SE. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM EST THURSDAY... GENERAL FLAVOR OF MODEL GUIDANCE REMAINS THE SAME FOR THE EXTENDED PERIOD AS A COLD FRONT MOVES THROUGH THE REGION SUNDAY NIGHT WITH A WAVE RIDING UP ALONG THE FRONT FROM THE SOUTHEAST. LOW LEVEL WARM AIR SURGING IN AHEAD OF THIS SYSTEM SHOULD HAVE PTYPE MOSTLY LIQUID UNTIL COLD AIR PUSHES IN FROM THE NORTHWEST LATER ON MONDAY...AND WE TRANSITION OVER TO SNOW AS BULK OF SYNOPTIC PCPN PULLS OUT. UPSLOPE SNOW SHOWERS WILL THEN AFFECT AREAS WEST OF THE BLUE RIDGE MONDAY NIGHT INTO TUESDAY WITH SOME ACCUMULATIONS POSSIBLE FOR THE WESTERN SLOPES. MAY SEE AN UPTICK IN SNOW SHOWERS TOWARD DAYBREAK TUESDAY AS A VIGOROUS SHORT WAVE MOVES SWINGS THROUGH THE BASE OF THE UPPER TROF AND PASSES OVER THE REGION. HIGH PRESSURE WILL THEN PUSH IN FROM THE SOUTHEAST AS MOISTURE RETREATS AND WE ARE QUIET AND COLD FOR LATE TUESDAY INTO WEDNESDAY. HIGH PRESSURE SLIDES OFF TO OUR EAST THURSDAY...ALLOWING SOUTHERLY RETURN FLOW TO MODERATE TEMPERATURES A BIT BEFORE WE SEE AFFECTS OF NEXT SYSTEM APPROACHING FROM THE MISSISSIPPI VALLEY THURSDAY NIGHT. IT LOOKS LIKE MONDAY NIGHT THROUGH TUESDAY NIGHT WILL SEE THE BEST CHANCES FOR WINDY CONDITIONS WITH GOOD DOWNWARD MOMENTUM TRANSFER ABLE TO BRING STRONG LOW LEVEL WINDS TO THE SURFACE. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... AS OF 1235 PM EST WEDNESDAY... MAINLY MVFR CONDITIONS ACROSS THE REGION CURRENTLY FOR CEILING HEIGHT. THE REMAINDER OF THE AFTERNOON THROUGH THE EARLY EVENING...A DISTURBANCE WILL CROSS THE REGION AND BRING SOME LIGHT PATCHY LIGHT RAIN...LIGHT SLEET OR LIGHT SNOW ACROSS...WITH THE BEST CHANCE FOR LIGHT FROZEN PRECIPITATION ACROSS THE MOUNTAINS. FLIGHT CATEGORIES WILL REMAIN PRIMARILY MVFR WITH SOME POCKETS OF IFR FOR CIGS AND MVFR FOR VSBYS. THE DISTURBANCE WILL EXIT THE REGION AROUND 04Z/11PM THIS EVENING TAKING THE PATCHY LIGHT PRECIPITATION WITH IT. NORTHWEST WINDS WILL GRADUALLY INCREASE THIS EVENING WITH SOME GUSTS AROUND 15-20KT. CIGS WILL SHOW ONLY GRADUAL IMPROVEMENT THE REMAINDER OF THE NIGHT THROUGH THE FORENOON FRIDAY. CONDITIONS WILL IMPROVE THE MOST RAPIDLY EAST OF THE CREST OF THE BLUE RIDGE THANKS TO A DOWNSLOPING COMPONENT. EXTENDED DISCUSSION... AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE EASTERN U.S. AND MAKE ITS WAY NORTHEAST THROUGH SATURDAY. ARCTIC HIGH PRESSURE WILL KEEP MOST AREAS VFR FRIDAY AND SATURDAY. THE EXCEPTION MAY BE SOME LATE NIGHT RIVER OR VALLEY FOG AND LINGERING UPSLOPE CLOUDS AND POSSIBLY -SHSN AT KBLF/KLWB INTO FRIDAY MORNING. ON SUNDAY INTO MONDAY...A STRONG UPPER WAVE AND ASSOCIATED COLD FRONT IS EXPECTED TO MOVE INTO AND/OR THROUGH THE REGION. THIS MAY BRING SUB-VFR CONDITIONS AND A WINTRY MIX OF PRECIPITATION. MODELS ARE COMING IN WARMER...SO THE TREND IS FOR MORE RAIN AND LESS WINTER PRECIPITATION THREAT. MOST WINTER PRECIPITATION SHOULD BE CONFINED TO THE MOUNTAINS...IMPACTING KLWB/KBLF TO SOME EXTENT...BUT BY NO MEANS A SIGNIFICANT WINTER EVENT. MORE WIDESPREAD -SHSN EXPECTED BEHIND THE FRONT MON NIGHT INTO TUE WITH SOME ACCUMULATIONS POSSIBLE AT THAT TIME...AGAIN MAINLY IMPACTING BLF/LWB. GUSTY NORTHWEST WINDS ARE EXPECTED BEHIND THE SYSTEM ON TUESDAY. && .CLIMATE... RECORD COOLEST HIGHS FRI NOV 14TH BLACKSBURG VA...35 IN 1986 BLUEFIELD WV....29 IN 1975 DANVILLE VA.....39 IN 1997 ROANOKE VA......37 IN 1976 LEWISBURG WV....30 IN 1975 LYNCHBURG VA....37 IN 1996 SAT NOV 15TH BLACKSBURG VA...32 IN 1976 BLUEFIELD WV....23 IN 1969 DANVILLE VA.....41 IN 1986 ROANOKE VA......34 IN 1969 LEWISBURG WV....29 IN 1995 LYNCHBURG VA....36 IN 1969 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS NEAR TERM...DS SHORT TERM...JH LONG TERM...MBS AVIATION...DS CLIMATE...DS
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AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1044 AM CST THU NOV 13 2014 .UPDATE... AN UPPER LEVEL TROUGH WILL VERY SLOWLY SWING THROUGH THE REGION TODAY. THERE IS PERSISTENT BUT VERY WEAK VORTICITY ADVECTION INTO SOUTHERN WI WITH THIS UPPER TROUGH. PERIODS OF LIGHT SNOW OR LIGHT SNOW SHOWERS OR SCATTERED FLURRIES /OR WHATEVER TERMINOLOGY YOU WOULD LIKE TO USE/ WILL PERSIST THROUGH THE AFTERNOON. RADAR MOSAIC SHOWS LIGHT RETURNS ALL ACROSS THE REGION WITH THE EXCEPTION OF EAST CENTRAL WI WHERE THERE ARE BREAKS IN THE CLOUDS. BUFKIT RAP SOUNDINGS SHOW STEEP LOW LEVEL LAPSE RATES WITHIN THE DENDRITE GROWTH ZONE /DGZ/ THROUGH THE WHOLE AFTERNOON WITH THE EXCEPTION OF OUR NORTH NEAR SHEBOYGAN WHERE THERE ARE DRIER PROFILES. I DEBATED ABOUT WHAT TO DO ABOUT POPS AND WEATHER SINCE THIS IS A HIGH-OCCURRENCE/TRACE EVENT. PER COLLABORATION WITH SURROUNDING OFFICES... WE ARE HANDLING THIS LIGHT SNOW WITH HIGH POPS AND DEFINITE LIGHT SNOW OR SOMETHING SIMILAR. && .AVIATION/18Z TAFS/... LINGERING LOW LEVEL RH AND PASSING WEAK DISTURBANCES WL RESULT IN MVFR CLOUDS AT TIMES AND PERSISTENT LIGHT SNOW/FLURRIES TODAY INTO THIS EVENING. CLOUDS SHOULD ERODE AND BECOME MORE WIDESPREAD VFR LATE TNGT INTO FRI MRNG. && .PREV DISCUSSION... /ISSUED 327 AM CST THU NOV 13 2014/ TODAY AND TONIGHT... FORECAST CONFIDENCE - MEDIUM. AREA OF MID-LEVEL SHEAR VORTICITY WL PASS OUT OF SOUTHEAST WI EARLY THIS MRNG AS FLURRIES CONTINUE TO DIMINISH OVER THE SOUTH. LOW LEVEL MOISTURE WILL LINGER OVER SRN WI INTO TNGT WITH EVEN A SLIGHT INCREASE IN THE MID LEVELS. SATELLITE IMAGERY AND VWP NETWORK SHOWING SECONDARY UPSTREAM MID-LEVEL CIRCULATION OVER NW WI/E CENTRAL MN REGION. SHORT TERM GUIDANCE IN GOOD AGREEMENT ON SWINGING THIS WEAK SHORT WAVE SOUTHWARD ACROSS SRN WI LATER THIS MRNG AND AFTN. SLIGHTLY DEEPER COLUMN RH WL ONCE AGAIN BE ABLE TO TAP INTO DENDRITIC GROWTH ZONE AS WEAK LIFT PASSES THRU. HENCE WL CONTINUE 20-30 PERCENT POPS. PAVEMENT TEMPS NOW BELOW FREEZING SO A LIGHT DUSTING WL BE POSSIBLE. LINGERING FLURRIES POSSIBLE THIS EVENING BEFORE INCREASING SUBSIDENCE FROM UPSTREAM SHORT WAVE RIDGING SETTLES IN LATE TNGT INTO FRI. CLOUDS MAY HANG ON INTO FRI MRNG. FRIDAY...FORECAST CONFIDENCE...HIGH SURFACE HIGH PRESSURE WILL MOVE OVERHEAD FRIDAY...BRINGING A FAIR AMOUNT OF SUNSHINE BY AFTERNOON AS DRIER LOW LEVEL AIR ARRIVES. THE SUNSHINE WILL NOT PUT MUCH OF A DENT IN THE COLD AIR THOUGH...WITH HIGHS STRUGGLING INTO THE UPPER 20S MOST PLACES. SATURDAY...FORECAST CONFIDENCE...MEDIUM MODELS REMAIN IN GOOD AGREEMENT WITH A SHORTWAVE SLIDING THROUGH SATURDAY NIGHT INTO SUNDAY MORNING. THOUGH THERE IS NOT A TON OF MOISTURE AND LIFT WITH THIS SYSTEM...FAIRLY DEEP SATURATION OCCURS FOR A TIME...WITH THE DENDRITE GROWTH ZONE VIA MODEL SOUNDINGS ABOUT 250-300 MB DEEP DURING THE PERIOD OF BEST LIFT. BEST Q-VECTOR CONVERGENCE AND DEEPEST SATURATION IS EXPECTED SAT EVENING AND OVERNIGHT...WHEN AROUND AN INCH OR TWO OF SNOW IS POSSIBLE. SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM SNOW IS EXPECTED TO WIND DOWN SUNDAY MORNING...WITH UPPER TROUGHING REMAINING OVER THE AREA THROUGH WEDNESDAY. WILL SEE A FEW EMBEDDED SHORTWAVES SLIDE THROUGH WHICH WILL BRING FLURRIES AT TIMES...BUT NOT SEEING ENOUGH MOISTURE/LIFT WITH THESE WEAK WAVES TO CONSIDER ADDING SLIGHT CHANCE POPS. THE COLD AIR IS EXPECTED TO REMAIN IN PLACE THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK. TEMPS EARLY NEXT WEEK MAY BE EVEN A BIT COLDER THAN THIS WEEK...WITH FORECAST HIGHS ABOUT 15 TO 20 DEGREES BELOW NORMAL. AVIATION/12Z TAFS/... LINGERING LOW LEVEL RH AND PASSING WEAK DISTURBANCES WL RESULT IN MORE MVFR CLOUDS AT TIMES AND ISOLD -SHSN/FLURRIES TODAY INTO THIS EVENING. CLOUDS SHOULD ERODE AND BECOME MORE WIDESPREAD VFR LATE TNGT INTO FRI MRNG. MARINE... WIND GUSTS ARE EXPECTED TO REMAIN MOSTLY BELOW 22 KNOTS THROUGH TONIGHT DESPITE SECONDARY WEAK SURGE OF LOW LEVEL COLD AIR MOVING ACROSS WARMER LAKE MI WATERS. FEW GUSTS TO 22 KNOTS MAY AFFECT SGNW3 BUT FOR THE MOST POINT BORDERLINE SITUATION WITH MOST GUSTS REMAINING BELOW ADVY LEVELS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...MRC TODAY/TONIGHT AND AVIATION/MARINE...MBK FRIDAY THROUGH WEDNESDAY...DDV
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1042 PM MST FRI NOV 14 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 232 PM MST FRI NOV 14 2014 ...ACTIVE WEATHER CONTINUES... CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING MODERATE TO STRONG WESTERLY FLOW ALOFT ACROSS THE REGION WITH ANOTHER EMBEBBED SHORT WAVE TRANSLATING ACROSS THE GREAT BASIN AND INTO WESTERN COLORADO. REGIONAL SATELLITE AND RADAR DATA INDICATING A GOOD SLUG OF MOISTURE MOVING INTO WESTERN COLORADO ALONG WITH A FEW LIGHTNING STRIKES ACROSS SOUTHEASTERN UTAH AT THIS TIME. TEMPERATURES AS OF 2 PM INDICATING SHALLOW COLD AIRMASS PERSISTING ACROSS SOUTHERN EL PASO COUNTY AND THE LOWER ARKANSAS RIVER VALLEY FROM CANON CITY TO LAMER...WITH TEMPS IN THE 20S TO LOWER 30S AT THIS TIME. ELSEWHERE ACROSS THE AREA...TEMPS HAVE WARMED INTO THE 40S TO LOWER 50S WITH MAINLY 20S AND 30S ACROSS THE CONTDVD. TONIGHT...MODELS CONTINUE TO BRING WAVE ACROSS THE AREA WITH MODERATE TO HEAVY SNOWFALL EXPECTED ACROSS THE CENTRAL AND SOUTHWEST MTS AND ACROSS THE HIGHER ELEVATIONS OF THE SANGRE DE CRISTO MTS THROUGH EARLY SATURDAY MORNING. CURRENT WINTER WEATHER HIGHLIGHTS LOOK ON TRACK WITH 4 TO 8 INCHES POSSIBLE OVERNIGHT. MODELS...TO A VARYING DEGREE...CONTINUE TO INDICATE A BAND OF PRECIPITATION... MOVING INTO THE LA GARITA MTS AT THIS TIME...CONTINUING TO SPREAD EAST ACROSS THE NORTHERN SAN LUIS VALLEY AND ACROSS THE LOWER ARKANSAS RIVER THROUGH THE LATE EVENING AND OVERNIGHT HOURS. WHILE THE 18Z NAM LOOKS HEAVY HANDED IN QPF...RAP AND HRRR HAVE A SIMILAR SET UP AND HAVE INCREASED POPS ACROSS THIS AREA TO MATCH KEEPING ACCUMULATIONS OF AN INCH OR LESS AT THIS TIME. HOWEVER...WILL NEED TO CONTINUE TO MONITOR THE DEVELOPMENT OF THIS BAND AS THE 18Z NAM IS GIVING UP TO 3 INCHES ACROSS THE LOWER ARK VALLEY TONIGHT. WITH EXPECTED CLOUD COVER...EXPECTING LOWS TO BE MAINLY IN THE 20S ACROSS THE AREA. TOMORROW...MODELS CONTINUE TO DIFFER ON TIMING OF THE NEXT SLUG OF ARCTIC AIR TO INVADE EASTERN COLORADO...ESPECIALLY ITS ASSOCIATED PRECIPITATION FIELD. NAM AND EC CONTINUE TO BE SLOWER WITH THE UPPER TROUGH MOVING ACROSS THE ROCKIES WITH THE GFS REMAINING FASTER. AT ANY RATE...HAVE PLAYED THE TIMING OF THE ARCTIC FRONT ACROSS THE PALMER DVD AROUND 18Z...THOUGH HAVE DELAYED ONSET OF PRECIPITATION INTO THE LATE AFTERNOON. GUSTY NORTH TO NORTHEAST WINDS OF 20 TO 30 MPH TO ANNOUNCE THE ARRIVAL OF THE FRONT...WHICH MAY BE ENOUGH TO BRIEFLY MIX OUT THE SHALLOW COLD AIRMASS IN PLACE ACROSS THE LOWER ARK VALLEY...BEFORE TEMPS COOL AGAIN BEHIND THE FRONT. NEEDLESS TO SAY...FORECASTING HIGH TEMPERATURES TOMORROW WILL AGAIN BE A CHALLENGE. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 232 PM MST FRI NOV 14 2014 ...SNOW CONTINUES SATURDAY NIGHT THROUGH SUNDAY... UPPER TROF WILL DROP IN FROM THE NORTHWEST SATURDAY NIGHT BRINGING A HEALTHY BOUT OF UPPER FORCING ACROSS THE AREA IS IT DROPS TO THE SOUTHEAST. THERE ARE STILL SOME TIMING DIFFERENCES IN THE MODELS WITH THE ONSET OF THE PRECIPITATION...ESPECIALLY FOR THE SOUTHEAST MTS/PLAINS. GFS IS A TOUCH FASTER WITH THE SOUTHWARD PROGRESSION OF THE UPPER TROF...WHICH MAY BE THE REASON IT IS TRENDING FASTER WITH THE ONSET OF PRECIPITATION VS THE SLOWER NAM12 AND ECMWF. FRONT WILL HAVE ALREADY BLASTED THROUGH SOUTHEAST CO BY 00Z SUN...AND GIVEN ITS ARCTIC ORIGIN...THIS TIMING LOOKS REASONABLE. HOWEVER...WITH THE UPPER FORCING IS STILL WELL OFF TO THE NORTH DURING THIS TIME PERIOD...AND A SLOWER TIMING TO THE ONSET OF PRECIPITATION...ESP FOR THE SE PLAINS...SEEMS MORE REASONABLE. NORTHEAST UPSLOPE BEHIND THE FRONT IS RATHER SHALLOW (BELOW H7) BUT AS UPPER TROF DROPS IN FROM THE NORTHWEST...THERE WILL BE A PERIOD OF UPGLIDE OVER THE COLD DOME DURING THE EVENING AND OVERNIGHT HOURS. THE GFS SHOWS SOME PRETTY GOOD DIV-Q...THE CORE OF WHICH PASSES ACROSS UT/THE 4 CORNERS REGION/SRN CO/AND NORTHERN NM. SO ALTHOUGH UPSLOPE IS SHALLOW FOR THE SOUTHEAST MTS...AND NOT THE BEST FOR THE SOUTHWEST MOUNTAINS WITH FLOW ALOFT MORE WESTERLY (INSTEAD OF THE MORE FAVORABLE SOUTHWEST DIRECTION)...HAVE SEEN THESE DYNAMIC SYSTEMS PRODUCE WIDESPREAD MODERATE TO HEAVY SNOWFALL AMOUNTS. WITH TIMING OF THE FORCING EXITING SOUTHERN CO AROUND OR SHORTLY AFTER 12Z SUN...PLAN TO KEEP THE HEADLINE TIMING FOR THE CONTINENTAL DIVIDE AS IS FOR NOW. HOWEVER...IF MOISTURE DIMINISHES RAPIDLY ENOUGH BEHIND THE TROF...ITS POSSIBLE THAT THE SNOW MAY DECREASE A BIT SOONER FARTHER NORTH ACROSS THE SAWATCH AND MOSQUITO RANGES. GIVEN THE INCONSISTENCIES BETWEEN MODELS...WILL LET LATER SHIFTS REFINE THE TIMING AS NEED BE. ADDITIONAL SNOWFALL AMOUNTS IN THE 4 TO 8 INCH RANGE LOOKS REASONABLE ALONG THE CONTINENTAL DIVIDE SAT NIGHT GIVEN THE PROBABILITY FOR 20+/1 LIQUID/SNOW RATIOS. STILL SOME UNCERTAINTY FOR SNOWFALL AMOUNTS ACROSS THE SOUTHEAST MOUNTAINS...AS THE GFS IS HEAVIER WITH QPF ACROSS THE PIKES PEAK REGION VS THE DRIER NAM12. HUNCH IS THAT SOUTHEAST MOUNTAINS AND PORTIONS OF THE I-25 CORRIDOR MAY NEED AN ADVISORY SAT NIGHT...WITH THE WETS AND SANGRES LIKELY TO SEE SOMEWHERE IN THE 3-8 INCH RANGE. TELLER AND EL PASO COUNTIES STILL VERY MUCH IN THE AIR WITH NAM SUGGESTING ONLY AN INCH OR TWO SAT NIGHT...WHILE GFS HAS 2 TO NEARLY 4 INCHES. GIVEN THE TRACK OF THE STRONGER FORCING ALOFT...IT DOES MAKE SENSE THAT THE LIGHTER NAM12 AMOUNTS COULD BE MORE REASONABLE. SUSPECT THAT SOME BANDING OF SNOW ALONG/SOUTH OF THE ARKANSAS RIVER WILL EXTEND EASTWARD ACROSS THE SOUTHEAST PLAINS...BUT SNOWFALL AMOUNTS AT THIS TIME APPEAR TO STAY BELOW ADVISORY LEVELS...PERHAPS 1-3" RANGE. AGAIN GIVEN THE COLD AIRMASS WITH THIS EVENT...IT SHOULD BE ANOTHER DRY FLUFFY SNOW EVENT. THE DIFFERENCE THIS TIME WILL BE THAT THE ROAD SURFACES WILL START OUT COLDER GIVEN OUR PREVIOUS COLD OUTBREAK. THIS COULD LIMIT THE ICING FACTOR SOME DEPENDING ON ASPHALT TEMPERATURES SATURDAY AFTERNOON. SNOW WILL END FROM NORTH TO SOUTH DURING THE MORNING ON SUNDAY...AND SNOW COVER WILL LIKELY KEEP TEMPERATURES FROM WARMING MUCH. HAVE DROPPED HIGHS A FEW DEGREES FROM THE CONSENSUS GRIDS...WHICH PUTS THEM CLOSER TO THE COLDER SIDE OF GUIDANCE VALUES. FORECAST DRIES OUT FOR THE REMAINDER OF THE EXTENDED. ANOTHER SURFACE HIGH DESCENDS THROUGH THE PLAINS WITH SOME UNCERTAINTIES AS TO HOW FAR WEST THE CORE OF COLD AIR ASSOCIATED WITH IT WILL GET. NAM12 AND EC ARE SEVERAL DEGREES COOLER WITH H7 TEMPS ACROSS THE PLAINS VS THE WARMER GFS MONDAY AFTERNOON...WHICH PUTS HIGH TEMPERATURES IN QUESTION ACROSS THE PLAINS. CURRENT GRIDS ARE CARRYING MID 20S TO AROUND 30...BUT THESE MAY NEED TO BE COOLED OFF EVEN FURTHER DEPENDING ON HOW THIS EVOLVES. NORTHERLY FLOW ALOFT GRADUALLY SHIFTS TO A MORE WESTERLY DIRECTION WHICH SHOULD BRING SOME MODERATING TEMPERATURES THROUGH MID TO LATE WEEK. ANOTHER PACIFIC SYSTEM MAY CUT THROUGH THE WESTERN U.S. UPPER RIDGE TOWARDS FRIDAY. FORECAST WILL CARRY GENERALLY DRY CONDITIONS UNTIL FRIDAY WITH TEMPERATURES WARMING BUT STILL REMAINING BELOW NORMAL. -KT && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1042 PM MST FRI NOV 14 2014 PRIMARILY VFR CONDITIONS ARE ANTICIPATED AT THE KALS...KCOS AND KPUB TAF SITES INTO SATURDAY AFTERNOON(OUTSIDE OF KALS...WHERE SOME LOW CLOUDS WILL BE POSSIBLE AT TIMES TONIGHT). METEOROLOGICAL CONDITIONS ARE THEN EXPECTED TO DETERIORATE FROM LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT...ESPECIALLY OVER THE KCOS AND KPUB TAF SITES AS MOIST NORTH TO NORTHEASTERLY SURFACE FLOW DEVELOPS IN THE WAKE OF A MODIFIED ARCTIC FRONT PROJECTED TO PUSH ACROSS THE SOUTHEASTERN COLORADO PLAINS DURING SATURDAY AFTERNOON. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. WINTER WEATHER ADVISORY UNTIL 5 AM MST SATURDAY FOR COZ073-075. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
303 AM CST SAT NOV 15 2014 .SHORT TERM /TODAY/... ISSUED AT 303 AM CST SAT NOV 15 2014 NO MAJOR CHANGES WITH ONGOING FORECAST FOR THE FIRST SIGNIFICANT SNOWFALL OF THE SEASON AS MODELS REMAIN IN GOOD AGREEMENT WITH EXPECTED SNOW TODAY. USED A BLEND OF THE HRRR/HOPWRF FOR TIMING OF PRECIP AND NAM/ECMWF TEMPS. BROAD ISENTROPIC LIFT AND DECENT MOISTURE TRANSPORT DEVELOP OVER WESTERN TO NORTHWEST IOWA THIS MORNING AND QUICKLY BLOSSOMS ACROSS THE REMAINDER OF THE STATE THIS AFTERNOON. ONE MINOR CHANGE WAS START THE SNOW A LITTLE SOONER THIS MORNING OVER THE WEST TO NORTHWEST AS SNOW ALREADY DEVELOPING ALOFT AND SNOW SHOULD START REACHING THE SURFACE BETWEEN 12-14Z THIS MORNING. THE 15.03Z HOPWRF AND 15.05Z HRRR HAVE SNOW MOVING INTO THE WESTERN EDGES OF THE FORECAST AREA BETWEEN 13-15Z. THE FORECAST SOUNDINGS ACROSS NORTHERN IOWA BECOME COMPLETELY SATURATED BY 17-18Z TODAY AND THE STRONGER OMEGA IS JUST AT THE TOP EDGE OF THE DENDRITIC LAYER BUT ENOUGH OVERLAP TO SEE SOME DECENT FLAKES...AND THUS SLIGHTLY HIGHER SNOW ACCUMULATION THIS AFTERNOON OVER NORTHERN IOWA. RAP IS A BIT LESS WITH THE FORCING THAN THE NAM/GFS AND HAS SLIGHTLY LOWER SNOW AMOUNTS GOING...BUT STILL DEPICTS ENOUGH SNOW TO WARRANT ADVISORY. FURTHER SOUTH...SOUNDINGS NOT TOO DISSIMILAR THAN NORTHERN IOWA...WITH THE MAIN DIFFERENCE BEING JUST SLIGHTLY LESSER FORCING WITHIN THE DENDRITIC LAYER. THIS RESULTING IN LESS SNOW AMOUNTS OVER THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA. LEANED TOWARD A BLEND OF THE WARMER NAM/ECMWF FOR TEMPERATURES TODAY. THIS RESULTED IN SNOW RATIOS AROUND 17:1 TO 18:1 OVER NORTHERN IOWA AND 15:1 TO 16:1 ACROSS THE SOUTH...BASED ON 925M TO 700MB THICKNESS. HAVE 100 POPS GOING MUCH OF THE AFTERNOON WITH HIGH CONFIDENCE ALL OF CENTRAL IOWA WILL BE SNOWING BY OR SHORTLY PAST 18Z. VERY LITTLE WIND TODAY BUT WITH THE FLUFFY SNOW TYPE EXPECTED AND AT TIMES FALLING MODERATELY...THIS SHOULD BE ENOUGH TO CAUSE SOME VISIBILITY RESTRICTION WITH A 6-9 KNOT WIND. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 303 AM CST SAT NOV 15 2014 ACTIVE WEATHER WILL CONTINUE THROUGH THE WEEKEND AND EARLY NEXT WEEK FOLLOWING TONIGHTS SYSTEM...ANOTHER INTENSE UPPER LEVEL LOW WILL DROP SOUTH INTO THE NORTHERN GREAT LAKES SUNDAY NIGHT AND MONDAY MORNING. TONIGHT...SYSTEM EXITING THE AREA TO THE EAST DURING THE EVENING HOURS. BEST FORCING ALONG H500 AND SFC TROUGH NEAR 00Z FOCUSING ON H700 BOUNDARY ACROSS NORTHERN IOWA. THROUGH 06Z THIS H700 BOUNDARY PUSHES EAST WITH TROUGH RESULTING IN LESSENING FORCING WEST OF I35 DURING THE LATE EVENING. BY 12Z BEST FORCING EAST OF THE AREA WITH SOME RESIDUAL LIGHT SNOW/FLURRIES OVER THE NORTHEAST ENDING QUICKLY WITH CLOUDS DEPARTING IN THE MORNING SUNDAY. SNOW RATIOS OF 18 TO 20:1 AND EXPECTED QPF AMOUNT YIELD SNOWFALL AMOUNTS OF UP TO ANOTHER 1.5 INCHES TONIGHT DURING THE EVENING AND OVERNIGHT HOURS. FORTUNATELY THE WINDS WILL BE LIGHT DURING THE EVENT...SO BLOWING SNOW WILL NOT BE AN ISSUE TONIGHT. WITH CLEARING BY MORNING...LOWS WILL QUICKLY FALL NORTHWEST AND WEST INTO THE SINGLE DIGITS WITH TEENS I35 EAST. SUNDAY WILL INITIALLY SEE SOME SUNSHINE BETWEEN WAVES BUT CLOUDS WILL INCREASE WEST DURING THE AFTERNOON. WITH H850 TEMPS IN THE -10C TO -12C RANGE AND WESTERLY WINDS...TEMPERATURES WILL BE TOLERABLE IN THE MID 20S OVER MOST OF THE AREA. AN APPROACHING COLD FRONT WILL SPREAD CLOUDS ACROSS THE REGION THROUGH EARLY EVENING. THE SECOND STRONG H500 LOW WILL FORCE A BULGE OF COLD AIR QUICKLY SOUTHEAST INTO WESTERN IOWA SUNDAY EVENING WITH RATHER STRONG COLD AIR ADVECTION AND INCREASING WINDS ALOFT. BY 12Z H850 TEMPS WILL HAVE FALLEN ANOTHER 8 TO 10C WITH READINGS FROM -16C TO -20C. THROUGH THE DAY MONDAY CLOUD COVER WILL OVERTAKE THE AREA WITH H850 TEMPS SETTLING TOWARD -18C TO -20C REGION WIDE. MODELS HAVE BEEN CONSISTENT WITH STEEPENING LAPSE RATES NEAR 15Z AND STRONG MIXING THROUGH THE DAY...POTENTIAL FOR SNOW SHOWERS ACROSS THE NORTHEAST WITH FLURRIES CENTRAL AND SOUTH. ALL IN ALL...MONDAY IS LOOKING RATHER UNPLEASANT. POTENTIAL FOR 15 TO 25 MPH WINDS WITH GUSTS TO NEAR 35 MPH AT TIMES. THIS WILL CAUSE PATCHY TO AREAS BLOWING SNOW OVER MUCH OF THE NORTHEAST HALF OF THE AREA WITH REDUCTIONS TO VISIBILITY. HEADLINES MAY BE NEEDED AGAIN ON MONDAY FOR THE COMBINATION OF WIND...BLOWING SNOW...AND COLD. HAVE EXPANDED THE POTENTIAL FOR LIGHT PRECIP AND BLOWING SNOW MONDAY ACROSS THE AREA. HIGHS WILL RECOVER LITTLE FROM FRIGID MORNING LOWS IN THE SINGLE DIGITS TO LOWER TEENS. BY AFTERNOON HIGHS NORTH WILL REACH THE LOWER TEENS TO THE LOWER 20S IN THE SOUTHEAST. TO TOP OFF THE WONDERFUL DAY...MINIMUM RECORD HIGHS LOOK LIKELY TO BE SET AT MANY LOCATIONS...ONE WHICH HAS NOT BEEN SEEN SINCE THE 1890S AND MANY SINCE THE 1950S. IN FACT...OUR HIGHS MONDAY WOULD STILL BE ABOUT 10 TO 15 DEGREES BELOW OUR COLDEST AVERAGE HIGHS FOR THE NORMALLY COLDEST WINTER DAY OF THE YEAR...OR ABOUT 30 DEGREES BELOW OUR NORMAL FOR 11/17. WE HAVENT HAD HIGHS THIS COLD SINCE EARLY MARCH OF 2014. TUESDAY WILL BEGIN QUITE COLD WITH A RIDGE JUST EDGING INTO THE AREA BUT WARM BY AFTERNOON. QUICKLY ANOTHER CLIPPER OVER THE NORTHERN PLAINS WILL MODERATE THE AIRMASS WITH BRISK WEST WINDS DEVELOPING DURING THE DAY. TEMPS WILL RISE INTO THE 20S. ANOTHER ARCTIC FRONT WILL DROP SOUTH INTO THE AREA TUESDAY NIGHT BUT THE AIRMASS WILL NOT BE QUITE AS COLD AS THE PREVIOUS. THE REMAINDER OF THE WEEK FEATURES A SERIES OF ARCTIC SHORT WAVES ROTATING AROUND THE HUDSON BAY PARENT H500 LOW...PULLING ADDITIONAL COLD AIR TOWARD THE GREAT PLAINS. NEXT WEEK WILL FEATURE DAYS WITH CLOUD COVER MIXED WITH SOME SUNSHINE AND CHILLY READINGS. FORTUNATELY BY LATE IN THE EXTENDED...TOWARD SATURDAY THE CROSS POLAR FLOW CUTS OFF...THE H500 RIDGE ACROSS THE WEST COAST BREAKS DOWN AND MORE ZONAL FLOW RESULTS OVER THE ROCKIES. THIS WILL CAUSE CHINOOK COMPRESSIONAL HEATING OVER THE PLAINS AND MODERATE HIGHS TO ABOVE FREEZING. FROM WEDNESDAY THROUGH FRIDAY HIGHS WILL APPROACH THE 30 DEGREE MARK WITH LOWS MODERATING INTO THE TEENS OVER THE AREA. LITTLE PRECIPITATION IS EXPECTED FOR MUCH OF THE PERIOD NEXT WEEK. && .AVIATION...15/06Z ISSUED AT 1121 PM CST FRI NOV 14 2014 BROAD AREA OF SN WILL PUSH EAST INTO SITES BEGINNING AFTER 12Z. SN WILL PERSIST AT SITES THROUGH MAJORITY OF PERIOD. CEILINGS AND VISIBILITIES WILL DROP TO MVFR AND TO IFR AT TIMES...ESPECIALLY WITH FALLING SNOW. SYSTEM WILL PUSH QUICKLY EAST AND MAY SEE VISIBILITIES IMPROVE AT WESTERN SITES...KFOD/KDSM BY END OF PERIOD BUT LOW MVFR OR IFR CEILINGS WILL REMAIN. && .DMX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE- BREMER-BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-CRAWFORD- DALLAS-DAVIS-DECATUR-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE- HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-LUCAS-MADISON- MAHASKA-MARION-MARSHALL-MONROE-PALO ALTO-POCAHONTAS-POLK- POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN- WAYNE-WEBSTER-WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...AWB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 AM EST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 416 AM EST SAT NOV 15 2014 A QUIET START TO THE SHORT TERM FORECAST THIS MORNING...AS THE AREA IS ON THE NORTHEAST EDGE OF A HIGH CENTERED FROM THE MID/UPPER MISSISSIPPI VALLEY TO THE OHIO RIVER VALLEY. THIS HAS LED TO A CLEAR AND COLD NIGHT ACROSS AT LEAST HALF OF THE CWA. WHERE WINDS HAVE DECOUPLED (GENERALLY ACROSS THE INTERIOR WEST AND NEAR THE WISCONSIN BORDER)...TEMPERATURES HAVE FALLEN INTO THE SINGLE DIGITS BELOW ZERO. MEANWHILE...OVER THE CENTRAL AND EAST WHERE THE WINDS HAVE BEEN STAYING UP...TEMPERATURES HAVE BEEN IN THE UPPER SINGLE DIGITS ABOVE ZERO TO MID TEENS. OVER LAKE SUPERIOR AND THE KEWEENAW...COLD AIR CONTINUING TO FLOW OVER THE RELATIVELY WARM WATERS OF LAKE SUPERIOR WAS PRODUCING MAINLY LAKE EFFECT CLOUDS THIS PAST EVENING AND INTO THE EARLY OVERNIGHT HOURS. BUT STARTED SEEING WEAK LAKE EFFECT BANDS OVER EASTERN LAKE SUPERIOR ON THE CANADIAN RADAR AT MONTREAL RIVER SHORTLY AFTER MIDNIGHT. INVERSION IS RIGHT AT 875-850MB ON 00Z KGRB/KINL SOUNDINGS AND THE LIMITED MOISTURE ON THE NORTH EDGE OF THE HIGH HAVE BEEN THE MAIN LIMITING FACTORS TO LAKE EFFECT SNOW EARLY THIS MORNING. KMQT VWP HAS BEEN SHOWING THE WINDS A LITTLE MORE OUT OF THE WEST-NORTHWEST AND CONTRIBUTING TO THE LAKE EFFECT CLOUDS NOSING SOUTHEAST INTO BARAGA...SOUTHERN HOUGHTON...AND EVEN FAR NORTHERN IRON COUNTY EARLY THIS MORNING. BUT AS WE HEAD INTO THE MORNING HOURS...MODELS SHOWING THE WINDS GOING BACK TO A MORE WESTERLY AND POTENTIALLY WEST-SOUTHWESTERLY DIRECTION AND CONFINING THE LAKE EFFECT CLOUDS AND SNOW POTENTIAL TO THE KEWEENAW AND OFF THE SHORELINE FROM GRAND MARAIS EASTWARD. THIS WILL ALSO BE AIDED BY THE LAND BREEZE THAT HAS DEVELOPED ALONG THE EASTERN U.P. SHORELINE AND WILL AID IN KEEPING THE BANDS OFFSHORE THERE. THE COVERAGE OF THE SHOWERS IS A LITTLE BIT OF A CONCERN DUE TO THE LIMITED MOISTURE...BUT WOULD EXPECT SOME UPTICK IN THE SNOW SHOWERS AS 875MB TEMPERATURES FALL FROM -11C ON THE RAP ANALYSIS TO -13/-14C BY THIS AFTERNOON. THUS...WILL CONTINUE TO SHOW POPS RAMPING UP TO HIGH CHANCES OVER THE KEWEENAW. WITH MUCH OF THE LAKE EFFECT CLOUD BELOW THE DGZ...WILL KEEP SNOW RATIOS ON THE LOW END FOR LAKE EFFECT AND ONLY HAVE ACCUMULATIONS AT A DUSTING TO AN INCH IN THAT AREA. OVER THE REST OF THE AREA...EXPECT A SUNNY START TO THE DAY WHICH WILL ALLOW TEMPERATURES TO RISE TO THE LOW-MID 20S THIS AFTERNOON. EXPECT MORE OF A FILTERED SUNSHINE IN THE AFTERNOON AS HIGH CLOUDS MOVE IN AHEAD OF THE WAVE BRUSHING THE AREA LATE TONIGHT. HEADING INTO TONIGHT...FOCUS TURNS TO THE SHORTWAVE CURRENTLY MOVING THROUGH WYOMING. THIS WAVE WILL QUICKLY SHIFT EAST THROUGH NEBRASKA AND SOUTH DAKOTA TODAY AND THEN LIFT NORTHEAST ACROSS NORTHERN LAKE MICHIGAN LATE TONIGHT AND SUNDAY MORNING. EXPECT THE HIGH CLOUDS TO THICKEN THIS EVENING AND MID CLOUDS TO MOVE IN DURING THE LATE EVENING AND OVERNIGHT. ANOTHER SHORTWAVE (CURRENTLY IN COLORADO) WILL LIFT NORTHEAST OUT AHEAD OF THE MAIN WAVE AND COULD PRODUCE A FEW SHOWERS AROUND MIDNIGHT. THE BETTER/MAIN FORCING (GENERALLY ABOVE 700MB) COMES FROM THE SECOND SHORTWAVE AND LOOKS TO STAY SOUTHEAST OF THE AREA...BUT DO EXPECT MENOMINEE COUNTY AND AREAS ALONG THE LAKE MICHIGAN SHORELINE TO SEE THE BEST OPPORTUNITY FOR ACCUMULATING SNOW. CURRENT FORECAST HAS SNOWFALL AMOUNTS UP TO AN INCH OVER SOUTHERN MENOMINEE COUNTY AND TAPERING OFF TO A HALF INCH OR LESS SOUTH OF A LINE FROM IRON MOUNTAIN TO MANISTIQUE. SINCE THE NORTHERN EDGE OF THE FORCING WILL BE JUST BRUSHING THE AREA...DO EXPECT A SHARP CUTOFF TO THE PRECIPITATION TO THE NORTHWEST AND KEEP THE SNOW CHANCES TO THE SOUTHEAST OF A LINE FROM MARQUETTE TO WATERSMEET. AS FOR THE LAKE EFFECT OVER THE KEWEENAW...THIS WAVE WILL BACK THE LOW LEVEL WINDS FARTHER TO THE SOUTHWEST AND FOCUS ANY LINGERING LAKE EFFECT TO THE FAR NORTHERN PORTIONS OF THE KEWEENAW PENINSULA. ACCUMULATIONS WILL REMAIN LIGHT AND BELOW 2 INCHES. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 409 AM EST SAT NOV 15 2014 A HI AMPLITUDE PATTERN FEATURING A TROF OVER CENTRAL AND ERN NAMERICA DOWNSTREAM OF A RDG ALONG THE W COAST WL DOMINATE THE WX PATTERN THIS COMING WEEK...LEADING TO PERSISTENT BLO TO WELL BLO NORMAL TEMPS THRU THE WEEK. THE MOST SGNFT WX CONCERN WL BE THE IMPACT OF A POTENT SHRTWV THAT IS FCST TO DIG SEWD THRU THE UPR LKS EARLY IN THE WEEK AND AMPLIFY THE TROF. THIS DISTURBANCE WL ALMOST CERTAINLY BRING ANOTHER ROUND OF MODERATE TO HEAVY LES AND SOME BLSN MAINLY TO THE NW WIND SN BELTS NEAR LK SUP ON MON INTO TUE. YET ANOTHER DISTURBANCE DIGGING THRU THE UPR TROF MAY BRING MORE SGNFT LES ON WED INTO THU. SUN...ONGOING LIGHT SN OVER THE SE CWA WL END BY EARLY IN THE AFTN AS SHRTWV OVER ERN WI AT 12Z AND ACCOMPANYING DYNAMIC FORCING/ DEEPER MSTR EXIT TO THE E THRU LOWER MI AND INTO FAR SE ONTARIO IN THE AFTN. AXIS OF DRIER AIR/DEEP LYR QVECTOR DVGC BTWN THIS DEPARTING SHRTWV AND ANOTHER MORE POTENT SHRTWV DIGGING SE THRU SCENTRAL CANADA WL THEN BRING A PERIOD OF DRY WX TO THE CWA. ALTHOUGH H85 TEMPS ARE FCST TO BE AS LO AS -12 TO -13C...THE FCST 230 DEGREE LLVL FLOW IN ADVANCE OF THE APRCHG SHRTWV WL HOLD ANY LES MAINLY TO THE NW OF THE KEWEENAW PENINSULA AND E OF LUCE/SCHOOLCRAFT COUNTIES. ALTHOUGH DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THE INCOMING SHRTWV ARE FCST TO INVADE THE WRN CWA LATER IN THE DAY... THE ABSENCE OF ANY SGNFT LLVL MSTR INFLOW WL MAINTAIN DRY WX THRU 00Z MON UNDER INCRSG HI/MID CLDS. SUN NIGHT...INCOMING SHRTWV/SFC LO ARE FCST TO DRIFT OVER NRN LK SUP BY 12Z MON AND CAUSE 12HR H5 HGT FALLS UP TO 120M ACROSS THE UPR LKS. AXIS OF DPVA/DEEP LYR QVECTOR CNVGC WITHIN THE COMMA TAIL OF THIS FEATURE ARE FCST TO SWING ACROSS UPR MI. HOWEVER...POTENTIAL FOR WIDESPREAD SN IN ADVANCE OF THE SHRTWV WL BE LIMITED BY THE ABSENCE OF LLVL MOISTENING/PWAT UNDER 0.25 INCH/H7 SPECIFIC HUMIDITY NO MORE THAN ABOUT 1 G/KG. STILL LOOKS LIKE THE LLVL FLOW WL NOT BACK SUFFICIENTLY TO ALLOW ANY LK ENHANCED OFF LK MI TO IMPACT LUCE OR SCHOOLCRAFT COUNTIES. THE BEST CHC FOR MORE WIDESPREAD/HEAVIER SNOW WL BE OVER THE W MAINLY LATE FOLLOWING COLD FROPA AND WIND SHIFT TO AN UPSLOPE NW DIRECTION. ARRIVAL OF H85 TEMPS AROUND -15C WITH SHARP CYC FLOW/LINGERING DEEP MSTR UNDER THE FALLING HGTS WILL WARRANT KEEPING LIKELY TO CATEGORICAL POPS OVER THE W. WL GO NO HIER THAN CHC POPS ELSEWHERE...WITH THE LOWEST SCHC POPS OVER THE SCENTRAL. MON/MON NGT...AS THE UPR TROF DEEPENS INTO THE GREAT LKS AND A CLOSED H5 LO FORMS...UPR MI IS FCST TO BE UNDER SHARP...CYC W VEERING NW FLOW ON MON AND NNW-NW FLOW ON MON NGT. FCST SDNGS SHOW DEEP MOISTURE/INSTABILITY AS H5 TEMPS DIP TOWARD -40C. GIVEN H85 TEMPS FALLING TO -16C TO -18C AND THE DEEP INSTABILITY/MOISTURE WITH THE CYC LLVL FLOW...CATEGORICAL POPS ARE WARRANTED IN THE FAVORED SN BELTS. GUSTY WINDS UNDER THE SHARP PRES GRADIENT/DESTABILIZATION WL CAUSE BLSN IN ADDITIONAL TO THE HEAVIER LES. FAVORABLE OMEGA PROFILE WITHIN THE DGZ SITUATED BTWN ABOUT 1-5K FT AGL WL ALSO ENHANCE SN/WATER RATIOS DESPITE THE IMPACT OF THE STRONG WINDS TO FRAGMENT THE SN FLAKES. RIGHT NOW... THE FAR W IN ONTONAGON/GOGEBIC COUNTIES LOOKS TO PICK UP THE HEAVIEST SN ON MON NGT...WITH ADDITIONAL HEAVY LES IMPACTING AREAS E OF MARQUETTE LATER ON MON THRU MON NGT. LATER SHIFTS NO DOUBT WL NEED TO HOIST LES HEADLINES. THE STRONG NW WINDS MAY ALSO CAUSE HI ENOUGH WAVES ON LK SUPERIOR TO BRING SOME MINOR BEACH EROSION/FLOODING IN AREAS MOST EXPOSED TO THE HIER WINDS/WAVES BEGINNING ON LATE MON. FOR NOW...WL CONTINUE TO MENTION THE SGFNT LES POTENTIAL/BLSN AND HI WAVES IN THE HWO PRODUCT AND EHWO GRAPHICS. TUE/TUE NGT...AS THE CLOSED LO SHIFTS INTO QUEBEC AND 12HR H5 HGT RISES APRCH 100M ON TUE IN THE LARGER SCALE DNVA AHEAD OF TRAILING H5 RDG AXIS...MID LVL SUBSIDENCE/DRYING/TREND TOWARD NEUTRAL OR MORE ACYC LLVL FLOW WL TEND TO WEAKEN THE LES W TO E. STEADILY BACKING WINDS OVER THE W THRU THE DAY AND MAINLY DURING TUE AFTN OVER THE E WL TEND TO LIMIT THE RESIDENCE TIME OF THE HEAVIER SN BANDS AND SHIFT THE LES TO PRIMARILY OVER THE KEWEENAW AND TO THE E OF MUNISING BY LATE IN THE DAY. DESPITE THIS DIMINISHING TREND...SN TOTALS ON MON THRU TUE WL LIKELY APRCH OR EXCEED A FOOT IN THE FAVORED SN BELTS OVER THE W CENTERED IN ONTONAGON COUNTY AND E OF MUNISING. AS THE FLOW CONTINUES TO BACK TOWARD THE SW ON TUE NGT IN ADVANCE OF NEXT CLIPPER SHRTWV DIGGING SEWD TOWARD MN...THE MAIN AREA OF LES SHOULD SHIFT INTO LK SUP. BUT MORE WIDESPREAD SN MAY ARRIVE LATE AT NGT AT LEAST OVER THE W WITH THE ONSET OF MORE VIGOROUS DYNAMIC FORCING/HGT FALLS IN THE DPVA AHEAD OF THE NEXT SHRTWV. WED THRU FRI...PASSAGE OF POTENT SHRTWV/VIGOROUS DYNAMIC FORCING WL BRING THE THREAT OF A MORE WIDESPREAD SN AGAIN ON WED DESPITE RATHER LIMITED ABSOLUTE MSTR /FCST PWAT UNDER 0.25 INCH/. MORE LES WL BE THE RULE ON THU INTO FRI MAINLY IN THE NW WIND SN BELTS AS ANOTHER COLD SHOT WITH H85 TEMPS AS LO AS -16 TO -18C POURS INTO THE UPR LKS BEHIND THE DEPARTING SHRTWV. LONGER RANGE MODELS CONTINUE TO POINT TOWARD SOME MODERATION IN THE COLD NEXT WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1153 PM EST FRI NOV 14 2014 WESTERLY WINDS ACROSS LAKE SUPERIOR AND SUFFICIENTLY COLD AIR WILL SUPPORT BKN-OVC MVFR CIGS AT KCMX THRU THE FCST PERIOD. OCNL FLURRIES/-SHSN ARE EXPECTED AS WELL. AT KIWD/KSAW...VFR CONDITIONS WILL PREVAIL THRU THE FCST PERIOD UNDER A RELATIVELY DRY AIR MASS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EST SAT NOV 15 2014 UNDER A SHARP PRES GRADIENT BETWEEN HI PRES IN THE OH RIVER VALLEY AND LO PRES OVER HUDSON BAY...PLAN ON W WINDS UP TO 20-30KTS INTO SUN. THE WINDS WL THEN BACK TOWARD THE SW AND DIMINISH TO UP TO 25KTS IN ADVANCE OF ANOTHER STRONG DISTURBANCE MOVING THRU SCENTRAL CANADA AND INTO NORTHERN LAKE SUPERIOR ON MON MORNING. FOLLOWING THE PASSAGE OF THIS LO TO THE E...THE PRES GRADIENT WILL TIGHTEN AND THE INSTABILITY WILL INCREASE AS ANOTHER SURGE OF COLD AIR FLOWS OVER THE RELATIVELY WARM LAKE WATERS. THE RESULT WILL BE A PERIOD OF NW GALES ON MON INTO TUE. SINCE THIS AIRMASS WILL BE SUFFICIENTLY COLD...THERE WILL LIKELY BE SOME FREEZING SPRAY IN SOME AREAS. THE BEST CHANCE FOR THE GALES WILL BE OVER CENTRAL LAKE SUPERIOR. AS THE LO PRES MOVES AWAY ON TUE AND HI PRES SHIFTS E...EXPECT THE WINDS TO BACK TO THE W AND DIMINISH TO 25 TO 30KTS. THE PASSAGE OF ANOTHER STRONG DISTURBANCE ON WED MAY LEAD TO ANOTHER NW GALE EVENT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...KC AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 AM EST SAT NOV 15 2014 .SYNOPSIS...HIGH PRESSURE WILL SETTLE OVER THE REGION ON SATURDAY... THEN SHIFT OFFSHORE SUNDAY AND SUNDAY NIGHT AS A COLD FRONT APPROACHES THE MOUNTAINS FROM THE WEST. A COLD FRONT WILL SURGE EASTWARD THROUGH THE CAROLINAS MONDAY EVENING. && .NEAR TERM /THROUGH SUNDAY/... AS OF 230 AM SATURDAY... TODAY AND TONIGHT: SURFACE HIGH PRESSURE WILL CENTER OVER NORTH CAROLINA AND VIRGINIA ON SATURDAY AS MID-LEVEL FLOW BECOMES ZONAL OR SLIGHTLY SOUTHWESTERLY. THAT MEANS THICKNESS VALUES WILL BEGIN TO RISE AND TEMPERATURES WILL BOTTOM OUT WITH THE MINIMUMS SATURDAY MORNING...IN THE LOW TO MID 20S. WITH NO DISTURBANCES IN THE UPPER LEVEL VORTICITY FIELD AND HIGH PRESSURE IN CONTROL...SATURDAY SHOULD BE A MOSTLY CLEAR DAY WITH MINIMAL WIND. THIS WILL GIVE CONDITIONS FOR INSOLATION BUT WITH THE COLD AIRMASS IN PLACE AND THICKNESS VALUES ONLY JUST APPROACHING 1300 N BY THE SATURDAY AFTERNOON...ONLY EXPECT HIGHS TO TOP OUT IN THE MID 40S ACROSS THE AREA. SLIGHT WARM AIR ADVECTION WILL MODERATE THICKNESS SATURDAY NIGHT BY TEN METERS OR SO...DRIVING A 3-5 DEGREE IMPROVEMENT IN LOW TEMPERATURES SUNDAY MORNING. SUNDAY: HIGH PRESSURE BEGINS TO SHIFT EASTWARD AND CENTRAL NC WILL BEGIN TO FEEL SOME RETURN FLOW. THIS WILL HELP MODERATE TEMPERATURES ON SUNDAY INTO THE LOWER 50S...STILL ABOUT 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. A VORTICITY MAXIMUM WILL APPROACH FROM THE SOUTH WHICH WILL CAUSE THE AREA TO OVERSPREAD WITH SOME 850 MB CLOUDINESS BY SUNDAY AFTERNOON. MOST OF THE AREA SHOULD REMAIN DRY HOWEVER AS PRECIPIATION ASSOCIATED WITH THE DEVELOPING TROUGH REMAINS TO THE SOUTHEAST AND THE APPROACHING FRONTAL SYSTEM REMAINS WEST OF THE AREA...DRAPED ACROSS THE DEEP SOUTH. THE CAVEAT TO THIS IS THAT THE POSITION OF THE SURFACE HIGH AND NEWLY FORMING TROUGH WILL HELP SET UP AN IN-SITU DAMMING SITUATION WITH A COASTAL FRONT THAT COULD PROVIDE THE MOISTURE FOR SOME LIGHT OVERRUNNING PRECIPITATION DRIVEN BY ISENTROPIC LIFT. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... AS OF 235 AM SATURDAY... SUNDAY NIGHT: HOW LONG THE IN-SITU DAMMING SITUATION HANGS AROUND REMAINS TO BE SEEN AS THE VERY DEEP UPPER LEVEL TROUGH OVER THE CENTRAL CONUS IS QUITE AGGRESSIVE WITH FORCING THE FRONTAL SYSTEM OVER THE APPALACHIANS INTO THE AREA AND BLOWING OUT THE WEDGE FRONT. WHETHER OR NOT THE DAMMING STICKS AROUND OR THE FRONT APPROACHES FROM THE WEST...THE UPSHOT WILL BE THE SAME...AN INCREASE IN POPS FOR SUNDAY NIGHT INTO EARLY MONDAY MORNING WITH THE GREATEST CHANCES IN THE NORTHWEST BUT QPF VALUES REMAINING UNDER A QUARTER OF AN INCH THROUGH 12Z MONDAY. INCREASED WARM AIR ADVECTION WILL HELP THICKNESS VALUES REACH 1350 M BY DAYBREAK ON MONDAY AND THUS LOWS WILL MODERATE SIGNIFICANTLY..INTO THE LOW TO MID 40S. -ELLIS FOR MON/MON NIGHT: MONDAY WILL START WITH THE WARM FRONT SW-TO-NE THROUGH CENTRAL NC MOVING TO THE NW... AS THE STRONG COLD FRONT APPROACHES FROM THE EAST. RAIN IS EXPECTED TO CONTINUE INTO MONDAY... WITH HIGHEST POPS IN THE NW HALF OF CENTRAL NC IN THE MORNING... SPREADING EAST THROUGH THE AFTERNOON. STRONG LOW LEVEL MASS FLUX CONFLUENCE COUPLED WITH VIGOROUS UPPER DIVERGENCE WILL CONTINUE TO FUEL WIDESPREAD PRECIP... WITH ADDITIONAL FORCING FOR ASCENT PROVIDED BY POCKETS OF MID LEVEL VORTICITY (DIFFICULT TO PINPOINT AT THIS RANGE) THAT WILL TRACK TO THE NE WITHIN THE FAST MID LEVEL SWRLY FLOW... PART OF THE STRONG BROAD TROUGH COVERING NEARLY THE ENTIRE CONUS. BASED ON THIS EXPECTED DEEP LIFT AND ABUNDANT MOISTURE (PW VALUES OVER 1.5 INCHES NOW OVER THE SOURCE REGION IN THE BAY OF CAMPECHE WILL SURGE NE INTO NC BY MON... EQUATING TO PW OF 2 STANDARD DEVIATIONS ABOVE NORMAL)... WILL BUMP UP POPS TO CATEGORICAL... MAINLY WEST HALF MON MORNING AND EXPANDING EAST IN THE AFTERNOON BEFORE SLOWLY EXITING IN THE EVENING. THE NAM/GFS/ECMWF ALL DIFFER SLIGHTLY WITH THE PLACEMENT AND STRENGTH OF SURFACE LOWS TRACKING ALONG THE INCOMING COLD FRONT... WITH THE GFS/ECMWF SHOWING STRONGER LOWS AND A SLIGHTLY FASTER FRONTAL PASSAGE THROUGH CENTRAL NC MON AFTERNOON/EVENING AS COMPARED TO THE NAM... BUT OVERALL TIMING IS IN FAIRLY DECENT AGREEMENT. BOTH THE NAM AND GFS DEPICT LOW BUT NON-ZERO MUCAPE VALUES IN THE EAST MON AFTERNOON INTO EARLY EVENING (100-250 J/KG ON THE GFS AND 250-750 J/KG ON THE NAM) WITH STRONG DEEP LAYER SHEAR OF 60-90 KTS... AND WHILE MID LEVEL LAPSE RATES ARE JUST MARGINAL AT 5.5-6.0 C/KM... THE MOISTURE ALOFT AND ASCENT ARE SUFFICIENT TO MENTION ISOLATED THUNDER IN THE ERN CWA LATE MON. TEMP FORECAST FOR MON IS A CHALLENGE... GIVEN THE HIGH POTENTIAL FOR A WEDGE REGIME TO HOLD IN THE NW PIEDMONT DESPITE A STRONG SSW LOW LEVEL FLOW PRECEDING THE FRONT. THE NAM REMAINS THE MOST SUPPORTIVE OF A LINGER WEDGE... IN LINE WITH THE 12Z/14TH ECMWF... HOWEVER THE NEW ECMWF IS CLOSER TO THE GFS WITH A STRONGER ALONG-FRONT SURFACE LOW AND RESULTING PREFRONTAL DISSOLUTION OF THE WEDGE REGIME. WITH THE LACK OF MODEL CONSENSUS ON THIS AND BASED ON PAST EXPERIENCE... WILL STICK WITH LINGERING COLDER AND MORE STABLE AIR OVER THE NW MON... BUT STAY TUNED... AS JUST A QUICK JUMP OF THE WARM FRONT MORE TO THE NW WILL YIELD MUCH HIGHER TEMPS. WILL HAVE HIGHS RANGING FROM AROUND 50 NW TO AROUND 70 SE... WITH PERIODICALLY GUSTY SW WINDS... ALTHOUGH THE MOIST ADIABATIC LOW LEVEL PROFILE COULD LIMIT MIXING OF THE STRONGEST WINDS DOWN TO THE SURFACE. EXPECT THE COLD FRONT TO MOVE QUICKLY EAST AND OFF THE COAST MON NIGHT... WITH MUCH COLDER AIR SURGING IN FROM THE NW... AND GRADUAL CLEARING OVERNIGHT. WE`LL HANG ONTO THE MIXED LAYER UP THROUGH ABOUT 900 MB OVERNIGHT... AND NW WINDS BEING THE FRONT WILL BE QUITE BRISK WITH OCCASIONAL GUSTS OVER 20 MPH POSSIBLE. THE POLAR CHARACTER OF THE INCOMING AIR MASS WITH LITTLE IMPEDIMENT TO ITS ARRIVAL SUPPORTS LOWS JUST A TAD LOWER THAN PREVIOUS LOWS... FROM 26 WEST TO 38 SOUTHEAST. -GIH && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 235 AM SATURDAY... WITH THE POLAR FLOODGATES WIDE OPEN... THE COLDEST AIR OF THIS STRETCH WILL BE UPON US TUE... MAKING THIS THE CHILLIEST DAY AS FORECAST THICKNESSES BOTTOM OUT BELOW 1275 M OVER MOST OF CENTRAL NC. THESE VALUES ALONG WITH FORECAST SOUNDINGS INDICATE A STRUGGLE TO GET OUT OF THE MID 30S OVER THE NW PIEDMONT... DESPITE PLENTIFUL SUNSHINE. HAVE TRENDED TEMPS IN THIS DIRECTION... WITH HIGHS FROM 37 NW TO 44 SE. THE TROUGH LIFTS NE AND WEAKENS A BIT WED/THU AS THE SURFACE HIGH MODIFIES WHILE SLIDING ACROSS THE SOUTHEAST STATES. SHOULD SEE HIGHS BACK UP INTO THE LOW-MID 40S THU AND AROUND 50-55 THU... STILL WELL BELOW NORMAL. A FEW HIGH CLOUDS ARE LIKELY TO RETURN LATE WED INTO WED NIGHT AS WEAK VORTICITY SHEARS ACROSS NC WITHIN THE PERSISTENT CYCLONIC FLOW. DETAILS IN THE GFS/ECMWF START TO GET VERY MURKY LATE THU INTO FRI AS LONGWAVE TROUGHING DIGS ANEW THROUGH THE GREAT LAKES AND POTENTIALL DOWN INTO THE CENTRAL PLAINS... WHICH WOULD MEAN THE SURFACE HIGH WOULD MOVE OFF THE COAST WITH RESULTANT SW RETURN FLOW PUMPING MOISTURE INTO THE CAROLINA AHEAD OF THE NEXT FRONT. WILL BRING IN SLIGHT CHANCE POPS ACROSS THE WEST AND NORTH... STILL BELOW CLIMATOLOGY AND IN LINE WITH THE ECMWF WHICH SHOWS PRECIP ENTERING WRN NC FRI. HIGHS FRI IN THE MID-UPPER 50S. EXPECT LOWS TUE NIGHT/WED MORNING IN THE TEENS TO LOW 20S... SLOWLY WARMING THROUGH THE END OF THE WEEK TO AROUND FREEZING FRI MORNING. -GIH && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 1235 AM SATURDAY... 24 HOUR TAF PERIOD: VERY HIGH CONFIDENCE OF VFR CONDITIONS PERSISTING THROUGH THE TAF PERIOD AS HIGH PRESSURE BEGINS TO MOVE OVERHEAD. THAT BEING SAID...THERE IS A THREAT TONIGHT FOR SOME LOW LEVEL WIND SHEAR IN THE 500-1000 FT LAYER AT EASTERN SITES (KRDU...KFAY...AND ESPECIALLY KRWI) WHERE WIND SPEEDS WILL GO FROM RELATIVELY LIGHT AT 500 FT TO 25-30 KTS OR SO AT 1000 FT. THIS IS BACKED UP BY WIND PROFILER DATA AT 530Z SHOWING 1 KT AT THE SURFACE AND 33 KTS AT 900 FT. RAP FORECAST SOUNDINGS SHOW THIS ACTIVITY CONTINUING UNTIL 13-14Z SATURDAY MORNING. OTHERWISE MOSTLY CLEAR SKIES OVERNIGHT WITH LIGHT NORTHWESTERLY WINDS SHIFTING TO NORTHEASTERLY DURING THE OVERNIGHT HOURS. FOR SATURDAY EXPECT WINDS 5-10 KTS OUT OF THE NORTHEAST THEN POSSIBLY SHIFTING TO A MORE EASTERLY DIRECTION LATER IN THE AFTERNOON. BY 00Z OR SO SOME MID TO HIGH LEVEL CLOUDS MAY START TO FILTER IN ABOVE 10 KFT. LONG TERM: THE NEXT THREAT TO SUB-VFR CONDITIONS WILL COME ON MONDAY AS A FRONTAL SYSTEM STARTS TO CROSS THE APPALACHIANS. HIGH PRESSURE WILL THEN RETURN ON TUESDAY FOR THE REMAINDER OF THE WEEK. && .CLIMATE... THE FOLLOWING ARE RECORD TEMPERATURES THAT WILL BE CHALLENGED THROUGH THE FORECAST PERIOD: RECORD LOW: GSO RDU FAY SAT 11/15 - 20 IN 1969 21 IN 1969 22 IN 1942 WED 11/19 - 20 IN 1951 21 IN 1903 21 IN 1959 THU 11/20 - 12 IN 1951 19 IN 1951 20 IN 1951 RECORD LOW MAX: GSO RDU FAY TUE 11/18 - 37 IN 1924 35 IN 1924 46 IN 2008 WED 11/19 - 34 IN 1951 36 IN 1951 41 IN 2000 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...ELLIS SHORT TERM...ELLIS/GIH LONG TERM...GIH AVIATION...ELLIS CLIMATE...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1236 AM EST SAT NOV 15 2014 .SYNOPSIS...HIGH PRESSURE WILL SETTLE OVER THE REGION ON SATURDAY... THEN SHIFT OFFSHORE SUNDAY AND SUNDAY NIGHT AS A COLD FRONT APPROACHES THE MOUNTAINS FROM THE WEST. THE COLD FRONT WILL SURGE EASTWARD THROUGH THE CAROLINAS MONDAY EVENING. && .NEAR TERM /TONIGHT/... AS OF 730 PM FRIDAY... MODIFIED ARCTIC HIGH PRESSURE BUILDING INTO THE REGION THIS EVENING WILL SETTLE OVERHEAD TONIGHT. WITH CLEAR SKIES AND A COLD/DRY AIRMASS IN PLACE...THE ONLY MITIGATING FACTOR W/REGARD TO THE REALIZATION OF FULL RADIATIONAL COOLING WILL BE A LIGHT NW BREEZE THROUGH 06-09Z. HOWEVER...PREVIOUS EXPERIENCE WOULD SUGGEST THAT SEVERAL HRS OF CALM CONDITIONS PRIOR TO SUNRISE SHOULD BE SUFFICIENT FOR LOWS IN THE LOW/MID 20S...PERHAPS UPPER TEENS IN A FEW LOCATIONS WHERE WINDS REMAIN CALM FROM MIDNIGHT ONWARD. -VINCENT && .SHORT TERM /SATURDAY THROUGH SUNDAY/... AS OF 250 PM FRIDAY... SURFACE HIGH OVER THE FORECAST AREA WILL DRIFT EAST...THOUGH SURFACE RIDGE AXIS WILL LINGER/EXTEND ACROSS THE REGION THROUGH EARLY SUNDAY. WHILE THE LOWEST 10K OF THE ATMOSPHERE WILL BE TOO DRY TO SUPPORT ANY CLOUDS...THE WLY FLOW ALOFT MAY ADVECT ENOUGH MOISTURE TO CAUSE AREAS OF CIRRUS OVERHEAD LATE SATURDAY MORNING THROUGH THE AFTERNOON. AT THIS TIME ANTICIPATE THE HIGH CLOUDS TO BE THIN...SO THEY SHOULD NOT HAVE ANY IMPACTS ON TEMPS. IF CIRRUS SHIELD THICKER/DENSER THAN CURRENTLY ANTICIPATED...THEN MAX TEMPS MAY END UP BEING 3-4 DEGREES COOLER THAN FORECAST. THE DRY AIR MASS WILL ALLOW TEMPS TO REBOUND FROM A FRIGID START. AFTERNOON TEMPS SHOULD BE IN THE MID-UPPER 40S. MODEL RH CROSS SECTIONS SUGGEST HIGH CLOUDS DEPARTING THE REGION EARLY SATURDAY EVENING WITH MAINLY CLEAR SKIES FOR MOST OF THE NIGHT UNTIL THE NEXT ROUND OF HIGH CLOUDS APPROACHES FROM THE WEST AROUND DAYBREAK SUNDAY. THE MAINLY CLEAR SKIES AND CALM WINDS WILL AGAIN ALLOW TEMPS TO FALL QUICKLY AFTER SUNSET. EXPECT MIN TEMPS SOLIDLY IN THE MID-UPPER 20S. SUNDAY...AS SURFACE HIGH RETREATS FARTHER AWAY FROM CENTRAL NC...THE LOW LEVEL RETURN SLY FLOW WILL ADVECT MOISTURE OFF THE ATLANTIC INTO THE SOUTHERN AND EASTERN SECTIONS OF CENTRAL NC. MODEL RH PLANE VIEW PLOTS SUGGEST THE AIR MASS BETWEEN 925-850 MB ADEQUATELY MOIST TO SUPPORT A DECK OF STRATOCU ACROSS THE SOUTHERN PIEDMONT...SANDHILLS...AND SOUTHERN COASTAL PLAIN BY SUNDAY AFTERNOON. OTHERWISE HIGH CLOUDS WILL THICKEN OVERHEAD ELSEWHERE IN ADVANCE OF THE NEXT LOW PRESSURE SYSTEM. THERE MAY BE ENOUGH ISENTROPIC UPGLIDE TO PERMIT THE DEVELOPMENT OF SPOTTY LIGHT RAIN OVER THE FAR SOUTH-SE AND POSSIBLY THE FAR NW PRIOR TO SUNSET SUNDAY. HIGH TEMPS SUNDAY WILL BE DICTATED TO THE EXTENT OF CLOUD COVER. AIR MASS PROJECTED TO MODIFY WITH LOW LEVEL THICKNESSES IN THE MID 1330S. THESE VALUES STILL ABOUT 15M BELOW NORMAL...SUPPORTIVE OF MAX TEMPS IN THE MID-UPPER 50S. SINCE EXPECTING THICKENING CLOUD COVER...MAX TEMPS SHOULD TOP OUT IN THE LOW-MID 50S. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... AS OF 305 PM FRIDAY... FOR THE PERIOD SUNDAY NIGHT THROUGH MONDAY...A SERIES OF MID-LEVEL SHORTWAVES ARE FORECAST TO MOVE THROUGH CENTRAL NORTH CAROLINA WITH THE BEST LIFT FORECAST BY BOTH THE NAM AND GFS DURING THE DAY MONDAY. THE NAM IS DRY FOR A LARGE PART OF SUNDAY NIGHT...WHICH IS CLOSER TO WHAT THE 12Z ECMWF IS FORECASTING...WHILE THE GFS SATURATES THE AIR MASS MUCH MORE QUICKLY SUNDAY NIGHT. BETTER 700MB VORTICITY IS FORECAST MONDAY BY BOTH THE NAM AND THE GFS...AND THE GREATER 850MB THETA-E AND K INDICES OCCUR THEN ALONG WITH THE PASSAGE OF BETTER VORTICITY ON THE 1.5PVU SURFACE AS THE RIGHT ENTRANCE REGION OF A 100KT 500MB JET APPROACHES LATE IN THE DAY. FOR THIS FORECAST...EVEN THE DRIER NAM PROVIDES FOR LIKELY CHANCES FOR RAIN IN THE TRIAD BY LATE SUNDAY NIGHT AND WILL BASICALLY FORECAST LIKELY CHANCES THERE AND TOWARD ALBEMARLE AFTER MIDNIGHT WITH CHANCES ELSEWHERE. FOR MONDAY...POPS WILL BE LIKELY WEST OF INTERSTATE 95 FOR MUCH OF THE DAY...WITH LIKELY POPS ALONG AND EAST OF INTERSTATE 95 AS THE 850MB THETA-E VALUES ARE MAXIMIZED IN CENTRAL NORTH CAROLINA DURING THE AFTERNOON. AROUND 18Z...THE GFS FORECASTS 850MB WINDS INCREASING TO AROUND 60KT IN THE COASTAL PLAIN COINCIDENT WITH THE INCREASE IN 850MB THETA-E. MUCAPE FROM 1000-500MB IS ONLY 100-200J/KG IN THE INTERSTATE 95 CORRIDOR MONDAY...AND NAM AND GFS BUFR SOUNDINGS SHOW LAPSE RATES NEAR MOIST ADIABATIC. HOWEVER...THE 0-3KM SHEAR IS AROUND 50KT... AND 0-3KM HELICITY IS FORECAST TO INCREASE INTO TRIPLE FIGURES M2/S2 ON BUFR SOUNDINGS AT KFAY AND KRWI BY 21Z. BUFR SOUNDINGS ALSO SHOW SOME EROSION THE CAP...AND WHILE THE WINDOW IS NARROW...LIKELY ONLY AROUND 19Z TO 22Z OR SO...THERE IS A NON-ZERO THREAT OF STRONGER... DEEP CONVECTION MONDAY AFTERNOON BUT FOR THIS FORECAST WILL HOLD OFF ON THE MENTION OF THUNDER IN ORDER TO EVALUATE TRENDS. IS THE SURFACE LOW IS DEEPER OR SURFACE DEW POINTS START TO FIND THEIR WAY MORE INTO THE 60S IN THE FAR EAST MONDAY AFTERNOON...THE POTENTIAL FOR LOCAL SEVERE WEATHER COULD INCREASE. GIVEN THE DISPARITY IN THE MODEL GUIDANCE LOWS FOR SUNDAY NIGHT... AND UNCERTAINTY IN HOW QUICKLY LOWER CLOUDS AND PRECIPITATION MAY DEVELOP...OPTED FOR A BLEND OF MOS VALUES FOR LOWS SUNDAY NIGHT IN THE LOWER TO MID 40S. ON MONDAY...CERTAINLY A CHALLENGE IN TERMS OF THE HIGHS CONSIDERING ANY COLD-AIR DAMMING...AND FOR THIS FORECAST WILL HAVE MAXES IN THE LOWER TO MID 50S IN THE IMMEDIATE TRIAD... TO NEAR 70 TOWARD KFAY AND KCTZ. GIVEN THE INCREASE IN 850MB AND 925MB WINDS EAST MONDAY AFTERNOON...THERE COULD BE A FEW GUSTS NEAR 30MPH IN THE COASTAL PLAIN THEN. FOR THE PERIOD MONDAY NIGHT THROUGH TUESDAY...WHILE THE GFS HAS BEEN FASTER THAN THE ECMWF WITH THE PASSAGE OF THE COLD FRONT AND THE RETURN OF MUCH COLDER AIR...EVEN THE SLOWER ECMWF WOULD SUGGEST THE COLD AIR CHASING THE MOISTURE MONDAY NIGHT SUCH THAT DRYING SHOULD OCCUR BEFORE PARTIAL THICKNESSES AND SURFACE WET BULB TEMPERATURES FALL TO RESULT IN ANY NON-LIQUID PRECIPITATION LATE MONDAY NIGHT. ANTICIPATING THE CHANCES FOR PRECIPITATION FALLING BELOW SLIGHT BY 12Z TUESDAY...CHANCE-TO-LIKELY POPS WEST TO EAST MONDAY EVENING DIMINISH OVERNIGHT WITH DRYING BEHIND THE COLD FRONT. IF THERE WOULD BE ANY NON-LIQUID PRECIPITATION...THE THOUGHT WOULD BE IT WOULD OCCUR EAST OF U.S. 1 IMMEDIATELY AT THE END OF THE PRECIPITATION AND HAVE NO IMPACT. FROM THERE...COLD HIGH PRESSURE BUILDS INTO CENTRAL NORTH CAROLINA WITH 1000-850MB THICKNESSES POSSIBLE FALLING INTO THE 1250S TUESDAY NIGHT WHICH BY LOCAL STUDY RESULTS IN LOWS WELL INTO THE 20S AND POSSIBLY INTO THE TEENS. FORECASTS OF MOISTURE ALOFT...WHICH SOMETIMES RESULTS IN CHALLENGES FOR VERY COLD OVERNIGHT LOWS...ARE DRY...WITH THE HIGH BUILDING IN MAKING FOR LIGHT WINDS AS WELL. AFTER HIGHS ON TUESDAY THAT MAY CHALLENGE THE RECORD LOW MAXIMUM TEMPERATURE AT KFAY DEPENDING ON THE MIDNIGHT TEMPERATURE EARLY TUESDAY...OVERNIGHT LOWS TUESDAY NIGHT SHOULD BE CLOSE TO RECORDS AT LEAST AT KGSO AND KRDU. THE DAYTIME HIGH WEDNESDAY AT KFAY WILL... AGAIN...LIKELY BE CLOSE TO THE RECORD LOW MAXIMUM THERE BASED ON THE EXPECTED HIGH TEMPERATURE FORECAST FROM THE 1000-850MB THICKNESSES. WHILE HIGH PRESSURE WILL BE IN PLACE AT THE SURFACE...A MODEST MID- LEVEL SHORTWAVE MOVING THROUGH OR NEAR CENTRAL NORTH CAROLINA LATE WEDNESDAY COULD RESULT IN THE PASSAGE OF SOME MID- OR HIGH-LEVEL CLOUDS THEN. GRADUAL WARMING SHOULD TAKE PLACE DURING THE END OF THE WEEK AS THE COLD...UPPER TROUGH STARTS TO RETREAT. OVERNIGHT LOWS THURSDAY NIGHT ARE COMPLICATED BY THE POTENTIAL FOR SOME HIGH CLOUDS AS THE UPPER FLOW BACKS. BY FRIDAY...A SURFACE FRONT SHOULD BE MOVING TOWARD THE VIRGINIA BORDER FROM THE NORTH...AND WHILE HIGH PRESSURE OVER THE GULF SHOULD LIMIT THE LOW-LEVEL MOISTURE RETURN TOWARD CENTRAL NORTH CAROLINA...BY OVERNIGHT FRIDAY THERE IS WHAT WILL CURRENTLY BE FORECAST AS A SLIGHT CHANCE OF RAIN MAINLY IN THE INTERSTATE 85 CORRIDOR. PARTIAL THICKNESSES ARE WELL TOO WARM FOR ANYTHING BUT LIQUID...BUT NOT CONFIDENT ENOUGH IN THE MOISTURE RETURN OR FRONTAL CONVERGENCE TO FORECAST POPS BEYOND SLIGHT AT THIS POINT. BY FRIDAY...TEMPERATURES SHOULD FINALLY RETURN CLOSE TO NORMAL. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 1235 AM SATURDAY... 24 HOUR TAF PERIOD: VERY HIGH CONFIDENCE OF VFR CONDITIONS PERSISTING THROUGH THE TAF PERIOD AS HIGH PRESSURE BEGINS TO MOVE OVERHEAD. THAT BEING SAID...THERE IS A THREAT TONIGHT FOR SOME LOW LEVEL WIND SHEAR IN THE 500-1000 FT LAYER AT EASTERN SITES (KRDU...KFAY...AND ESPECIALLY KRWI) WHERE WIND SPEEDS WILL GO FROM RELATIVELY LIGHT AT 500 FT TO 25-30 KTS OR SO AT 1000 FT. THIS IS BACKED UP BY WIND PROFILER DATA AT 530Z SHOWING 1 KT AT THE SURFACE AND 33 KTS AT 900 FT. RAP FORECAST SOUNDINGS SHOW THIS ACTIVITY CONTINUING UNTIL 13-14Z SATURDAY MORNING. OTHERWISE MOSTLY CLEAR SKIES OVERNIGHT WITH LIGHT NORTHWESTERLY WINDS SHIFTING TO NORTHEASTERLY DURING THE OVERNIGHT HOURS. FOR SATURDAY EXPECT WINDS 5-10 KTS OUT OF THE NORTHEAST THEN POSSIBLY SHIFTING TO A MORE EASTERLY DIRECTION LATER IN THE AFTERNOON. BY 00Z OR SO SOME MID TO HIGH LEVEL CLOUDS MAY START TO FILTER IN ABOVE 10 KFT. LONG TERM: THE NEXT THREAT TO SUB-VFR CONDITIONS WILL COME ON MONDAY AS A FRONTAL SYSTEM STARTS TO CROSS THE APPALACHIANS. HIGH PRESSURE WILL THEN RETURN ON TUESDAY FOR THE REMAINDER OF THE WEEK. && .CLIMATE... THE FOLLOWING ARE RECORD TEMPERATURES THAT WILL BE CHALLENGED THROUGH THE FORECAST PERIOD: RECORD LOW: GSO RDU FAY SAT 11/15 - 20 IN 1969 21 IN 1969 22 IN 1942 WED 11/19 - 20 IN 1951 21 IN 1903 21 IN 1959 THU 11/20 - 12 IN 1951 19 IN 1951 20 IN 1951 RECORD LOW MAX: GSO RDU FAY TUE 11/18 - 37 IN 1924 35 IN 1924 46 IN 2008 WED 11/19 - 34 IN 1951 36 IN 1951 41 IN 2000 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...WSS LONG TERM...DJF AVIATION...ELLIS CLIMATE...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1236 PM EST FRI NOV 14 2014 .SYNOPSIS...HIGH PRESSURE WILL SETTLE OVER THE REGION ON SATURDAY... THEN SHIFT OFFSHORE SUNDAY AND SUNDAY NIGHT AS A COLD FRONT APPROACHES THE MOUNTAINS FROM THE WEST. THE COLD FRONT WILL SURGE EASTWARD THROUGH THE CAROLINAS MONDAY EVENING. && .NEAR TERM /TONIGHT/... AS OF 730 PM FRIDAY... MODIFIED ARCTIC HIGH PRESSURE BUILDING INTO THE REGION THIS EVENING WILL SETTLE OVERHEAD TONIGHT. WITH CLEAR SKIES AND A COLD/DRY AIRMASS IN PLACE...THE ONLY MITIGATING FACTOR W/REGARD TO THE REALIZATION OF FULL RADIATIONAL COOLING WILL BE A LIGHT NW BREEZE THROUGH 06-09Z. HOWEVER...PREVIOUS EXPERIENCE WOULD SUGGEST THAT SEVERAL HRS OF CALM CONDITIONS PRIOR TO SUNRISE SHOULD BE SUFFICIENT FOR LOWS IN THE LOW/MID 20S...PERHAPS UPPER TEENS IN A FEW LOCATIONS WHERE WINDS REMAIN CALM FROM MIDNIGHT ONWARD. -VINCENT && .SHORT TERM /SATURDAY THROUGH SUNDAY/... AS OF 250 PM FRIDAY... SURFACE HIGH OVER THE FORECAST AREA WILL DRIFT EAST...THOUGH SURFACE RIDGE AXIS WILL LINGER/EXTEND ACROSS THE REGION THROUGH EARLY SUNDAY. WHILE THE LOWEST 10K OF THE ATMOSPHERE WILL BE TOO DRY TO SUPPORT ANY CLOUDS...THE WLY FLOW ALOFT MAY ADVECT ENOUGH MOISTURE TO CAUSE AREAS OF CIRRUS OVERHEAD LATE SATURDAY MORNING THROUGH THE AFTERNOON. AT THIS TIME ANTICIPATE THE HIGH CLOUDS TO BE THIN...SO THEY SHOULD NOT HAVE ANY IMPACTS ON TEMPS. IF CIRRUS SHIELD THICKER/DENSER THAN CURRENTLY ANTICIPATED...THEN MAX TEMPS MAY END UP BEING 3-4 DEGREES COOLER THAN FORECAST. THE DRY AIR MASS WILL ALLOW TEMPS TO REBOUND FROM A FRIGID START. AFTERNOON TEMPS SHOULD BE IN THE MID-UPPER 40S. MODEL RH CROSS SECTIONS SUGGEST HIGH CLOUDS DEPARTING THE REGION EARLY SATURDAY EVENING WITH MAINLY CLEAR SKIES FOR MOST OF THE NIGHT UNTIL THE NEXT ROUND OF HIGH CLOUDS APPROACHES FROM THE WEST AROUND DAYBREAK SUNDAY. THE MAINLY CLEAR SKIES AND CALM WINDS WILL AGAIN ALLOW TEMPS TO FALL QUICKLY AFTER SUNSET. EXPECT MIN TEMPS SOLIDLY IN THE MID-UPPER 20S. SUNDAY...AS SURFACE HIGH RETREATS FARTHER AWAY FROM CENTRAL NC...THE LOW LEVEL RETURN SLY FLOW WILL ADVECT MOISTURE OFF THE ATLANTIC INTO THE SOUTHERN AND EASTERN SECTIONS OF CENTRAL NC. MODEL RH PLANE VIEW PLOTS SUGGEST THE AIR MASS BETWEEN 925-850 MB ADEQUATELY MOIST TO SUPPORT A DECK OF STRATOCU ACROSS THE SOUTHERN PIEDMONT...SANDHILLS...AND SOUTHERN COASTAL PLAIN BY SUNDAY AFTERNOON. OTHERWISE HIGH CLOUDS WILL THICKEN OVERHEAD ELSEWHERE IN ADVANCE OF THE NEXT LOW PRESSURE SYSTEM. THERE MAY BE ENOUGH ISENTROPIC UPGLIDE TO PERMIT THE DEVELOPMENT OF SPOTTY LIGHT RAIN OVER THE FAR SOUTH-SE AND POSSIBLY THE FAR NW PRIOR TO SUNSET SUNDAY. HIGH TEMPS SUNDAY WILL BE DICTATED TO THE EXTENT OF CLOUD COVER. AIR MASS PROJECTED TO MODIFY WITH LOW LEVEL THICKNESSES IN THE MID 1330S. THESE VALUES STILL ABOUT 15M BELOW NORMAL...SUPPORTIVE OF MAX TEMPS IN THE MID-UPPER 50S. SINCE EXPECTING THICKENING CLOUD COVER...MAX TEMPS SHOULD TOP OUT IN THE LOW-MID 50S. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... AS OF 305 PM FRIDAY... FOR THE PERIOD SUNDAY NIGHT THROUGH MONDAY...A SERIES OF MID-LEVEL SHORTWAVES ARE FORECAST TO MOVE THROUGH CENTRAL NORTH CAROLINA WITH THE BEST LIFT FORECAST BY BOTH THE NAM AND GFS DURING THE DAY MONDAY. THE NAM IS DRY FOR A LARGE PART OF SUNDAY NIGHT...WHICH IS CLOSER TO WHAT THE 12Z ECMWF IS FORECASTING...WHILE THE GFS SATURATES THE AIR MASS MUCH MORE QUICKLY SUNDAY NIGHT. BETTER 700MB VORTICITY IS FORECAST MONDAY BY BOTH THE NAM AND THE GFS...AND THE GREATER 850MB THETA-E AND K INDICES OCCUR THEN ALONG WITH THE PASSAGE OF BETTER VORTICITY ON THE 1.5PVU SURFACE AS THE RIGHT ENTRANCE REGION OF A 100KT 500MB JET APPROACHES LATE IN THE DAY. FOR THIS FORECAST...EVEN THE DRIER NAM PROVIDES FOR LIKELY CHANCES FOR RAIN IN THE TRIAD BY LATE SUNDAY NIGHT AND WILL BASICALLY FORECAST LIKELY CHANCES THERE AND TOWARD ALBEMARLE AFTER MIDNIGHT WITH CHANCES ELSEWHERE. FOR MONDAY...POPS WILL BE LIKELY WEST OF INTERSTATE 95 FOR MUCH OF THE DAY...WITH LIKELY POPS ALONG AND EAST OF INTERSTATE 95 AS THE 850MB THETA-E VALUES ARE MAXIMIZED IN CENTRAL NORTH CAROLINA DURING THE AFTERNOON. AROUND 18Z...THE GFS FORECASTS 850MB WINDS INCREASING TO AROUND 60KT IN THE COASTAL PLAIN COINCIDENT WITH THE INCREASE IN 850MB THETA-E. MUCAPE FROM 1000-500MB IS ONLY 100-200J/KG IN THE INTERSTATE 95 CORRIDOR MONDAY...AND NAM AND GFS BUFR SOUNDINGS SHOW LAPSE RATES NEAR MOIST ADIABATIC. HOWEVER...THE 0-3KM SHEAR IS AROUND 50KT... AND 0-3KM HELICITY IS FORECAST TO INCREASE INTO TRIPLE FIGURES M2/S2 ON BUFR SOUNDINGS AT KFAY AND KRWI BY 21Z. BUFR SOUNDINGS ALSO SHOW SOME EROSION THE CAP...AND WHILE THE WINDOW IS NARROW...LIKELY ONLY AROUND 19Z TO 22Z OR SO...THERE IS A NON-ZERO THREAT OF STRONGER... DEEP CONVECTION MONDAY AFTERNOON BUT FOR THIS FORECAST WILL HOLD OFF ON THE MENTION OF THUNDER IN ORDER TO EVALUATE TRENDS. IS THE SURFACE LOW IS DEEPER OR SURFACE DEW POINTS START TO FIND THEIR WAY MORE INTO THE 60S IN THE FAR EAST MONDAY AFTERNOON...THE POTENTIAL FOR LOCAL SEVERE WEATHER COULD INCREASE. GIVEN THE DISPARITY IN THE MODEL GUIDANCE LOWS FOR SUNDAY NIGHT... AND UNCERTAINTY IN HOW QUICKLY LOWER CLOUDS AND PRECIPITATION MAY DEVELOP...OPTED FOR A BLEND OF MOS VALUES FOR LOWS SUNDAY NIGHT IN THE LOWER TO MID 40S. ON MONDAY...CERTAINLY A CHALLENGE IN TERMS OF THE HIGHS CONSIDERING ANY COLD-AIR DAMMING...AND FOR THIS FORECAST WILL HAVE MAXES IN THE LOWER TO MID 50S IN THE IMMEDIATE TRIAD... TO NEAR 70 TOWARD KFAY AND KCTZ. GIVEN THE INCREASE IN 850MB AND 925MB WINDS EAST MONDAY AFTERNOON...THERE COULD BE A FEW GUSTS NEAR 30MPH IN THE COASTAL PLAIN THEN. FOR THE PERIOD MONDAY NIGHT THROUGH TUESDAY...WHILE THE GFS HAS BEEN FASTER THAN THE ECMWF WITH THE PASSAGE OF THE COLD FRONT AND THE RETURN OF MUCH COLDER AIR...EVEN THE SLOWER ECMWF WOULD SUGGEST THE COLD AIR CHASING THE MOISTURE MONDAY NIGHT SUCH THAT DRYING SHOULD OCCUR BEFORE PARTIAL THICKNESSES AND SURFACE WET BULB TEMPERATURES FALL TO RESULT IN ANY NON-LIQUID PRECIPITATION LATE MONDAY NIGHT. ANTICIPATING THE CHANCES FOR PRECIPITATION FALLING BELOW SLIGHT BY 12Z TUESDAY...CHANCE-TO-LIKELY POPS WEST TO EAST MONDAY EVENING DIMINISH OVERNIGHT WITH DRYING BEHIND THE COLD FRONT. IF THERE WOULD BE ANY NON-LIQUID PRECIPITATION...THE THOUGHT WOULD BE IT WOULD OCCUR EAST OF U.S. 1 IMMEDIATELY AT THE END OF THE PRECIPITATION AND HAVE NO IMPACT. FROM THERE...COLD HIGH PRESSURE BUILDS INTO CENTRAL NORTH CAROLINA WITH 1000-850MB THICKNESSES POSSIBLE FALLING INTO THE 1250S TUESDAY NIGHT WHICH BY LOCAL STUDY RESULTS IN LOWS WELL INTO THE 20S AND POSSIBLY INTO THE TEENS. FORECASTS OF MOISTURE ALOFT...WHICH SOMETIMES RESULTS IN CHALLENGES FOR VERY COLD OVERNIGHT LOWS...ARE DRY...WITH THE HIGH BUILDING IN MAKING FOR LIGHT WINDS AS WELL. AFTER HIGHS ON TUESDAY THAT MAY CHALLENGE THE RECORD LOW MAXIMUM TEMPERATURE AT KFAY DEPENDING ON THE MIDNIGHT TEMPERATURE EARLY TUESDAY...OVERNIGHT LOWS TUESDAY NIGHT SHOULD BE CLOSE TO RECORDS AT LEAST AT KGSO AND KRDU. THE DAYTIME HIGH WEDNESDAY AT KFAY WILL... AGAIN...LIKELY BE CLOSE TO THE RECORD LOW MAXIMUM THERE BASED ON THE EXPECTED HIGH TEMPERATURE FORECAST FROM THE 1000-850MB THICKNESSES. WHILE HIGH PRESSURE WILL BE IN PLACE AT THE SURFACE...A MODEST MID- LEVEL SHORTWAVE MOVING THROUGH OR NEAR CENTRAL NORTH CAROLINA LATE WEDNESDAY COULD RESULT IN THE PASSAGE OF SOME MID- OR HIGH-LEVEL CLOUDS THEN. GRADUAL WARMING SHOULD TAKE PLACE DURING THE END OF THE WEEK AS THE COLD...UPPER TROUGH STARTS TO RETREAT. OVERNIGHT LOWS THURSDAY NIGHT ARE COMPLICATED BY THE POTENTIAL FOR SOME HIGH CLOUDS AS THE UPPER FLOW BACKS. BY FRIDAY...A SURFACE FRONT SHOULD BE MOVING TOWARD THE VIRGINIA BORDER FROM THE NORTH...AND WHILE HIGH PRESSURE OVER THE GULF SHOULD LIMIT THE LOW-LEVEL MOISTURE RETURN TOWARD CENTRAL NORTH CAROLINA...BY OVERNIGHT FRIDAY THERE IS WHAT WILL CURRENTLY BE FORECAST AS A SLIGHT CHANCE OF RAIN MAINLY IN THE INTERSTATE 85 CORRIDOR. PARTIAL THICKNESSES ARE WELL TOO WARM FOR ANYTHING BUT LIQUID...BUT NOT CONFIDENT ENOUGH IN THE MOISTURE RETURN OR FRONTAL CONVERGENCE TO FORECAST POPS BEYOND SLIGHT AT THIS POINT. BY FRIDAY...TEMPERATURES SHOULD FINALLY RETURN CLOSE TO NORMAL. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 1235 AM SATURDAY... 24 HOUR TAF PERIOD: VERY HIGH CONFIDENCE OF VFR CONDITIONS PERSISTING THROUGH THE TAF PERIOD AS HIGH PRESSURE BEGINS TO MOVE OVERHEAD. THAT BEING SAID...THERE IS A THREAT TONIGHT FOR SOME LOW LEVEL WIND SHEAR IN THE 500-1000 FT LAYER AT EASTERN SITES (KRDU...KFAY...AND ESPECIALLY KRWI) WHERE WIND SPEEDS WILL GO FROM RELATIVELY LIGHT AT 500 FT TO 25-30 KTS OR SO AT 1000 FT. THIS IS BACKED UP BY WIND PROFILER DATA AT 530Z SHOWING 1 KT AT THE SURFACE AND 33 KTS AT 900 FT. RAP FORECAST SOUNDINGS SHOW THIS ACTIVITY CONTINUING UNTIL 13-14Z SATURDAY MORNING. OTHERWISE MOSTLY CLEAR SKIES OVERNIGHT WITH LIGHT NORTHWESTERLY WINDS SHIFTING TO NORTHEASTERLY DURING THE OVERNIGHT HOURS. FOR SATURDAY EXPECT WINDS 5-10 KTS OUT OF THE NORTHEAST THEN POSSIBLY SHIFTING TO A MORE EASTERLY DIRECTION LATER IN THE AFTERNOON. BY 00Z OR SO SOME MID TO HIGH LEVEL CLOUDS MAY START TO FILTER IN ABOVE 10 KFT. LONG TERM: THE NEXT THREAT TO SUB-VFR CONDITIONS WILL COME ON MONDAY AS A FRONTAL SYSTEM STARTS TO CROSS THE APPALACHIANS. HIGH PRESSURE WILL THEN RETURN ON TUESDAY FOR THE REMAINDER OF THE WEEK. && .CLIMATE... THE FOLLOWING ARE RECORD TEMPERATURES THAT WILL BE CHALLENGED THROUGH THE FORECAST PERIOD: RECORD LOW: GSO RDU FAY SAT 11/15 - 20 IN 1969 21 IN 1969 22 IN 1942 WED 11/19 - 20 IN 1951 21 IN 1903 21 IN 1959 THU 11/20 - 12 IN 1951 19 IN 1951 20 IN 1951 RECORD LOW MAX: GSO RDU FAY TUE 11/18 - 37 IN 1924 35 IN 1924 46 IN 2008 WED 11/19 - 34 IN 1951 36 IN 1951 41 IN 2000 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...WSS LONG TERM...DJF AVIATION...ELLIS CLIMATE...MWS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
346 AM EST SAT NOV 15 2014 .SYNOPSIS... HIGH PRESSURE LINGERS TODAY. NEXT SYSTEM WITH DEEPER MOISTURE SUNDAY NIGHT INTO MONDAY. REINFORCING COLD AIR ARRIVES MONDAY NIGHT INTO TUESDAY. COLDEST DAY TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... STRATUS HANGING TOUGH OVER THE N MOUNTAINS ATTM WHICH IS KEEPING TEMPS UP AT EKN COMPARED A HAIR. EXPECT THESE CLOUDS TO DISSIPATE PER HRRR OVER THE NEXT SEVERAL HRS. ELSEWHERE...QUITE COLD WITH TEMPS RUNNING A BIT BLOW FCST CURVE IN THE OUTLYING AREAS. ADJUSTED HOURLY TEMPS AND MINT GRID DOWN A FEW DEGREES...ESPECIALLY AWAY FROM URBAN CENTERS. MID TEENS LOOK LIKE A GOOD BET ACROSS THESE LOCATIONS ACROSS THE LOWLANDS. IF THE CLOUDS OVER THE MOUNTAINS CAN CLEAR IN TIME...THEN SOME HIGH SINGLE NUMBERS ARE POSSIBLE OVER THE HIGH RIDGES. SNOWSHOE CURRENTLY SITTING AT 11F. AS FOR TODAY...THE SUN WILL FINALLY MAKE AN APPEARANCE...ALBEIT WITH A SHORT STAY. SOME CIRRUS WILL STREAK IN DURING THE FIRST HALF OF TODAY...FOLLOWED BY INCREASE IN MID LEVEL CLOUDS ASSOCIATED WAA ALOFT LATE IN THE AFTERNOON AND EARLY EVENING /FROM SW TO NE/. H85 TEMPS WILL MODERATE BY ALMOST 10 DEGREES TODAY. STILL...WITH H925 TEMPS STILL ON THE COOL SIDE...FELT ROLLING WITH COOLER GUIDANCE /A LA LOCAL IN HOUSE MOS/ WAS THE BEST OPTION. AS SUCH...HAVE SOME MID 30S FOR THE LOWLANDS WITH LOWER 30S FOR THE HIGH TERRAIN. BIGGEST IMPROVEMENT IN TEMPS COMPARED TO YESTERDAY WILL BE FELT IN THE HIGHER ELEVATIONS WHERE SNOWSHOE SHOULD MAKE A RUN TOWARD UPPER 20S LATE IN THE DAY VERSUS LOW TEENS OBSERVED YESTERDAY. A MID LEVEL DISTURBANCE WILL RACE THROUGH THE REGION TONIGHT. HOWEVER...WITH LITTLE FANFARE OTHER THAN THE INCREASE IN MIDDLE LEVEL CLOUDS. THE WAA ALOFT CONTINUES THOUGH...SO HAVE HIGHEST RIDGES HOLDING NEAR STEADY IF NOT RISING TOWARD MORNING WITH GENERALLY MID 20S IN THE LOWLANDS. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... A WAVE MOVING ACROSS SATURDAY NIGHT INTO SUNDAY SUFFERS FROM LACK OF LOW LEVEL MOISTURE. SHOULD SEE LOTS OF VIRGA...BUT QUESTIONABLE HOW MUCH MAKES IT TO THE GROUND. WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE CATEGORIES...SLOWING INCREASING AS THE COLUMN TRIES TO SATURATE. MAIN SYSTEM OF INTEREST ARRIVES SUNDAY NIGHT AND CONTINUES INTO MONDAY. SREF/NAM/ECMWF ARE THE WARMEST OF THE MODELS...WITH THE GFS AND CANADIAN ON THE COOLER SIDE. WILL RUN IN BETWEEN THE 2 CAMPS FOR NOW...KEEPING A BAND OF PRECIPITATION IN THE MIDDLE THAT COULD BE EITHER RAIN OR SNOW. THIS BASICALLY KEEPS MOST OF WV AND VA AS RAIN...WITH A TRANSITION ZONE ACROSS NORTHEAST KY/SOUTHEAST OH AND FAR NW WV. CENTRAL OH HAS THE BEST CHANCE OF BEING ALL SNOW. THE TIMING OF THE TRANSITION TO SNOW IS ALSO UP FOR DEBATE ON MONDAY WITH TIMING DIFFERENCES BETWEEN THE MODELS. WILL GO BELOW MOS GUIDANCE OF HIGHS ON MONDAY DUE TO FALLING PRECIPITATION. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... THE SUPPORT FROM THE STRENGTHENING 250 MB JET SHOULD BE TO OUR EAST BY MONDAY EVENING...WITH THE REINFORCING COLD ARCTIC AIR BLOWING IN. LIKE YESTERDAY AND THE DAY BEFORE THAT...WE WILL CONTINUE TO HOLD ONTO TO HIGHER POPS LONGER IN SOME ACCUMULATING SNOW SHOWERS MONDAY EVENING THAN MODEL GUIDANCE....AS DEW POINTS LOWER IN THE COLD AIR ADVECTION. DRIER ARCTIC AIR TAKES CONTROL FOR TUESDAY WITH LOW DEW POINTS. SO DESPITE THE 850 MB THERMAL TROF...DO NOT WANT TO BE AS PESSIMISTIC AS WE USUALLY ARE ON CLOUDS IN THE LOW LEVEL THERMAL TROF. YET...STILL LEFT SOME FLAKES IN THE AIR WELL THROUGH TUESDAY NIGHT FOR THE MOUNTAIN COUNTIES. COLDEST DAY MAXIMUM READINGS SHOULD BE TUESDAY. MOST LOWLAND READINGS IN THE 20S FOR MAXIMUM. OUR SMALL AREA AOA 4000 FEET SHOULD REMAIN IN SINGLE DIGITS DURING THE DAY ON TUESDAY. AN IDEAL CLEAR/CALM NIGHT MAY BE HARD TO FIND...SINCE HIGH PRESSURE CENTER NOT DIRECTLY OVER US. BUT WINDS SHOULD DIMINISH TUESDAY NIGHT. SO COLDEST TEMPERATURES FOR LOWLANDS LIKELY TUESDAY NIGHT/EARLY WEDNESDAY. CONTINUED DRY WEDNESDAY INTO THURSDAY. WARM AIR ADVECTION MOISTURE INCREASES THURSDAY NIGHT INTO FRIDAY. WILL HAVE CHANCE POPS SPREADING SW TO NE OVERNIGHT THURSDAY NIGHT INTO FRIDAY. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD EXCEPT FOR SOME MVFR CIGS OVER KBKW EARLY THIS MORNING. AN INCREASE IN HIGH AND MIDDLE LEVEL CLOUDS CAN BE EXPECTED AS THE DAY PROGRESSES. THIS TREND CONTINUES TONIGHT WITH PASSAGE OF AN UPPER LEVEL DISTURBANCE. FLOW SURFACE AND ALOFT WILL BE LIGHT TODAY COURTESY OF HIGH PRESSURE. FLOW ALOFT INCREASES OUT OF SW 20 TO 25 KTS TONIGHT BUT SURFACE WINDS ACROSS TAF SITES WILL REMAIN LIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: HIGH ALTERNATE SCENARIOS: NONE 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 SAT 11/15/14 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H H H H H H 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 H H H H H 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 H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z SUNDAY... IFR POSSIBLE SUNDAY NIGHT INTO TUESDAY IN PRECIPITATION AND CLOUDS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/RPY/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...KTB AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
135 AM EST SAT NOV 15 2014 .SYNOPSIS... HIGH PRESSURE LINGERS TODAY. NEXT SYSTEM WITH DEEPER MOISTURE SUNDAY NIGHT INTO MONDAY. REINFORCING COLD AIR ARRIVES MONDAY NIGHT INTO TUESDAY. COLDEST DAY TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... STRATUS HANGING TOUGH OVER THE N MOUNTAINS ATTM WHICH IS KEEPING TEMPS UP AT EKN COMPARED A HAIR. EXPECT THESE CLOUDS TO DISSIPATE PER HRRR OVER THE NEXT SEVERAL HRS. ELSEWHERE...QUITE COLD WITH TEMPS RUNNING A BIT BLOW FCST CURVE IN THE OUTLYING AREAS. ADJUSTED HOURLY TEMPS AND MINT GRID DOWN A FEW DEGREES...ESPECIALLY AWAY FROM URBAN CENTERS. MID TEENS LOOK LIKE A GOOD BET ACROSS THESE LOCATIONS ACROSS THE LOWLANDS. IF THE CLOUDS OVER THE MOUNTAINS CAN CLEAR IN TIME...THEN SOME HIGH SINGLE NUMBERS ARE POSSIBLE OVER THE HIGH RIDGES. SNOWSHOE CURRENTLY SITTING AT 11F. AS FOR TODAY...THE SUN WILL FINALLY MAKE AN APPEARANCE...ALBEIT WITH A SHORT STAY. SOME CIRRUS WILL STREAK IN DURING THE FIRST HALF OF TODAY...FOLLOWED BY INCREASE IN MID LEVEL CLOUDS ASSOCIATED WAA ALOFT LATE IN THE AFTERNOON AND EARLY EVENING /FROM SW TO NE/. H85 TEMPS WILL MODERATE BY ALMOST 10 DEGREES TODAY. STILL...WITH H925 TEMPS STILL ON THE COOL SIDE...FELT ROLLING WITH COOLER GUIDANCE /A LA LOCAL IN HOUSE MOS/ WAS THE BEST OPTION. AS SUCH...HAVE SOME MID 30S FOR THE LOWLANDS WITH LOWER 30S FOR THE HIGH TERRAIN. BIGGEST IMPROVEMENT IN TEMPS COMPARED TO YESTERDAY WILL BE FELT IN THE HIGHER ELEVATIONS WHERE SNOWSHOE SHOULD MAKE A RUN TOWARD UPPER 20S LATE IN THE DAY VERSUS LOW TEENS OBSERVED YESTERDAY. A MID LEVEL DISTURBANCE WILL RACE THROUGH THE REGION TONIGHT. HOWEVER...WITH LITTLE FANFARE OTHER THAN THE INCREASE IN MIDDLE LEVEL CLOUDS. THE WAA ALOFT CONTINUES THOUGH...SO HAVE HIGHEST RIDGES HOLDING NEAR STEADY IF NOT RISING TOWARD MORNING WITH GENERALLY MID 20S IN THE LOWLANDS. && .SHORT TERM /SUNDAY THROUGH MONDAY/... SURFACE HIGH PRESSURE EXITING TO THE EAST AT THE START OF THE PERIOD. MOISTURE BEGINS INCREASING SATURDAY NIGHT INTO SUNDAY...AND AS A WEAK SHORTWAVE PASSES TO OUR NORTH WE COULD SQUEEZE OUT A LITTLE SNOW ACROSS NW CORNER OF CWA. STILL PRETTY DRY AT THE SURFACE...SO ONLY HAVE LOW CHANCE POPS WITH THIS. MOISTURE CONTINUES TO INCREASE THROUGH SUNDAY. SOME UNCERTAINTY ON JUST HOW QUICKLY THE COLUMN WILL SATURATE AND PRECIP WILL BEGIN. MODELS SEEM TO HAVE BACKED OFF JUST A TOUCH...SO REDUCED POPS SOME SUNDAY MORNING. POPS RAMP UP PRETTY QUICKLY AS WARM AIR ADVECTION CONTINUES MOISTURE INFLOW AND STARTS PROVIDING LIFT. IN REALITY WILL LIKELY BE AN EVEN TIGHTER POP GRADIENT THAN CURRENT FORECAST AS COLUMN SATURATES. WITH THE WARM AIR ADVECTION FOLLOWED BY COLD SURGE FROM THE WEST...ANTICIPATE A WARM WEDGE SETTING UP ACROSS THE WV LOWLANDS FOR SUNDAY NIGHT INTO MONDAY. FARTHER WEST...NEAR THE OHIO RIVER...COLDER AIR WILL PUSH IN CHANGING RAIN TO SNOW SUNDAY NIGHT. MODELS IN GOOD AGREEMENT WITH JET DYNAMICS TAKING OVER SUNDAY NIGHT...INCREASING PRECIP EFFICIENCY AS DIVERGENCE FROM A 130-150KT JET STREAK SETS UP OVER THE OHIO RIVER VALLEY. MODELS ALSO IN GOOD AGREEMENT ON 850MB TEMPERATURE FIELD...WITH RATHER TIGHT GRADIENT CENTERED ROUGHLY OVER THE OHIO RIVER. THIS WILL ALLOW ACCUMULATING SNOW FROM THE OHIO RIVER WEST...WITH MORE OF A RAIN/SNOW/SLEET MIX EAST OF THE RIVER...AND EVEN JUST RAIN ACROSS THE SOUTHERN COAL FIELDS INTO MONDAY AFTERNOON. WITH THE COLD AIR AND JET STREAK LINING UP PRETTY WELL...EXPECTING A GOOD BAND OF SNOW DEVELOPING OVER SE OHIO. HAVE GENERALLY 2-4 INCHES. ANTICIPATE A BAND OF 4 OR MORE SOMEWHERE JUST WEST OF THE OHIO RIVER...BUT CANNOT PIN POINT THAT THIS FAR OUT. THAT WILL PUT US RIGHT AT THE WINTER WEATHER ADVISORY/WARNING CRITERIA LINE WHERE EVER THAT BAND SETS UP. WILL CONTINUE MENTION OF POSSIBLE WINTER HEADLINES IN HWO...AND HOPEFULLY THE HIGHER RESOLUTION NEAR TERM MODELS WILL BEGIN PROVIDING USEFUL INPUT INTO THE MOST LIKELY PLACEMENT FOR THE BAND OF HIGHER SNOW OVER THE NEXT SEVERAL SHIFTS. FARTHER EAST...ACROSS THE HIGHEST TERRAIN OF THE WV MOUNTAINS...THERE COULD BE A BRIEF PERIOD OF SOME LIGHT FREEZING RAIN AND/OR SLEET AS TEMPERATURES ALOFT WARM SUNDAY NIGHT. AS THE COLD AIR CONTINUES TRYING TO ERODE THE WARM WEDGE MONDAY AND THE UPPER LEVEL JET SINKS SE ACROSS FORECAST AREA...HAVE ANY REMAINING RAIN CHANGING BACK OVER TO SNOW FROM WEST TO EAST...BECOMING ALL SNOW BY 22Z-23Z. BLENDED IN GFS/ECMWF INTO PREVIOUS TEMP FORECAST THROUGH SUNDAY NIGHT...AND THEN WENT NON-DIURNAL MONDAY AS COLD AIR SURGES IN. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... THE SUPPORT FROM THE STRENGTHENING 250 MB JET SHOULD BE TO OUR EAST BY MONDAY EVENING...WITH THE REINFORCING COLD ARCTIC AIR BLOWING IN. LIKE YESTERDAY AND THE DAY BEFORE THAT...WE WILL CONTINUE TO HOLD ONTO TO HIGHER POPS LONGER IN SOME ACCUMULATING SNOW SHOWERS MONDAY EVENING THAN MODEL GUIDANCE....AS DEW POINTS LOWER IN THE COLD AIR ADVECTION. DRIER ARCTIC AIR TAKES CONTROL FOR TUESDAY WITH LOW DEW POINTS. SO DESPITE THE 850 MB THERMAL TROF...DO NOT WANT TO BE AS PESSIMISTIC AS WE USUALLY ARE ON CLOUDS IN THE LOW LEVEL THERMAL TROF. YET...STILL LEFT SOME FLAKES IN THE AIR WELL THROUGH TUESDAY NIGHT FOR THE MOUNTAIN COUNTIES. COLDEST DAY MAXIMUM READINGS SHOULD BE TUESDAY. MOST LOWLAND READINGS IN THE 20S FOR MAXIMUM. OUR SMALL AREA AOA 4000 FEET SHOULD REMAIN IN SINGLE DIGITS DURING THE DAY ON TUESDAY. AN IDEAL CLEAR/CALM NIGHT MAY BE HARD TO FIND...SINCE HIGH PRESSURE CENTER NOT DIRECTLY OVER US. BUT WINDS SHOULD DIMINISH TUESDAY NIGHT. SO COLDEST TEMPERATURES FOR LOWLANDS LIKELY TUESDAY NIGHT/EARLY WEDNESDAY. CONTINUED DRY WEDNESDAY INTO THURSDAY. WARM AIR ADVECTION MOISTURE INCREASES THURSDAY NIGHT INTO FRIDAY. WILL HAVE CHANCE POPS SPREADING SW TO NE OVERNIGHT THURSDAY NIGHT INTO FRIDAY. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD EXCEPT FOR SOME MVFR CIGS OVER KBKW EARLY THIS MORNING. AN INCREASE IN HIGH AND MIDDLE LEVEL CLOUDS CAN BE EXPECTED AS THE DAY PROGRESSES. THIS TREND CONTINUES TONIGHT WITH PASSAGE OF AN UPPER LEVEL DISTURBANCE. FLOW SURFACE AND ALOFT WILL BE LIGHT TODAY COURTESY OF HIGH PRESSURE. FLOW ALOFT INCREASES OUT OF SW 20 TO 25 KTS TONIGHT BUT SURFACE WINDS ACROSS TAF SITES WILL REMAIN LIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: HIGH ALTERNATE SCENARIOS: NONE 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 SAT 11/15/14 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H H H H H H 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 H H H H H 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 H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z SUNDAY... IFR POSSIBLE SUNDAY NIGHT INTO TUESDAY IN PRECIPITATION AND CLOUDS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/RPY/30 NEAR TERM...30 SHORT TERM...MZ LONG TERM...KTB AVIATION...30
AREA FORECAST DISCUSSION
NWS NORMAN OK
1054 PM CST FRI NOV 14 2014 .DISCUSSION... AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW. && .AVIATION... OVERALL...VFR CONDITIONS ARE EXPECTED TO CONTINUE. A LIGHT WINTRY MIX OF PRECIPITATION IS POSSIBLE NEARLY ANYWHERE THROUGH 18Z. CONFIDENCE OF PRECIPITATION OCCURRENCE REMAINS TOO LOW TO MENTION AT THIS TIME AS MOST PRECIPITATION WILL LIKELY STAY NORTH OF THE OKLAHOMA KANSAS STATELINE. THERE IS AN OUTSIDE CHANCE FOR MVFR CEILINGS TO DEVELOP ACROSS THE AREA AFTER 09Z...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. SOUTH TO SOUTHEAST WINDS WILL BECOME GUSTY AT MANY SITES 09-16Z...THEN DIMINISH 20-24Z. A COLD FRONT WILL BRING A WIND SHIFT TO THE NORTH NEAR KWWR AND KGAG AROUND 21Z...AND TO OTHER SITES 22-02Z. MBS && .PREV DISCUSSION... /ISSUED 719 PM CST FRI NOV 14 2014/ UPDATE... ADJUSTED PRECIPITATION TYPE ACROSS NORTHERN OKLAHOMA AFTER MIDNIGHT TONIGHT THROUGH EARLY SATURDAY AFTERNOON TO INCLUDE SLEET. DISCUSSION... A LIGHT WINTRY MIX OF MAINLY LIGHT SLEET AND LIGHT SNOW IS POSSIBLE AFTER MIDNIGHT TONIGHT THROUGH 3 PM SATURDAY ACROSS NORTHERN OKLAHOMA. LATEST HRRR RUNS HAVE BEEN DEPICTING LIGHT PRECIPITATION DEVELOPING AS LIFT INCREASES IN NORTHWEST OKLAHOMA MIDNIGHT TO 4 AM TONIGHT...THEN SPREADING EAST...AFFECTING AREAS NORTH OF A GAGE TO STILLWATER LINE. FORECAST PRECIPITATION CHANCES ARE IN GOOD SHAPE AND WERE NOT ALTERED. BASED ON THE LATEST 00Z NEARBY UPPER AIR SOUNDINGS AND TOP DOWN SOUNDING METHODOLOGY...BELIEVE ANY PRECIPITATION REACHING THE GROUND WOULD MAINLY BE LIGHT SLEET AS PRECIPITATION ALOFT WOULD PARTIALLY OR COMPLETELY MELT WITH A 720-800 MB WARM NOSE OF +1 TO +6C THEN REFREEZE 800-850 MB WITH TEMPERATURES AROUND -9C. LIGHT SNOW WOULD BE POSSIBLE IF PRECIPITATION INTENSITY BECOMES HEAVY ENOUGH TO ALLOW EVAPORATIONAL COOLING TO ERODE THE MID LEVEL WARM NOSE. LATEST RAP13 RUNS HINT THAT THIS COULD OCCUR NORTH OF AN ALVA TO STILLWATER LINE AFTER 4 AM TONIGHT. REGARDLESS OF PRECIPITATION TYPE...ANY PRECIPITATION AMOUNTS APPEAR TO BE LIGHT IN NORTHERN OKLAHOMA WITH THE HEAVIER AMOUNTS FARTHER NORTH ACROSS NORTHERN KANSAS LATE TONIGHT INTO SATURDAY. COULD NOT COMPLETELY RULE OUT A DUSTING OF SLEET OR SNOW ACCUMULATIONS MIDNIGHT TONIGHT TO 3 PM SATURDAY OVER NORTHERN OKLAHOMA...BUT THINK IMPACTS WILL BE MINIMAL DUE TO THE LIGHT NATURE OF PRECIPITATION AND LACK OF SIGNIFICANT NEARBY MOISTURE. HOWEVER...WITH SURFACE TEMPERATURES BELOW FREEZING...A FEW SLICK SPOTS COULD DEVELOP. WILL CONTINUE TO MONITOR. PRODUCTS HAVE BEEN UPDATED. NO WINTER WEATHER ADVISORIES ARE EXPECTED TO BE ISSUED FOR TONIGHT THROUGH SATURDAY AFTERNOON AT THIS TIME. MBS PREV DISCUSSION... /ISSUED 255 PM CST FRI NOV 14 2014/ DISCUSSION... SHORT TERM...(TONIGHT-SUNDAY NIGHT) LOW CLOUDS SHOULD CONTINUE TO ERODE THROUGH THE AFTERNOON WHILE HIGH CLOUDS SLOWLY INCREASE. A QUICK MOVING SYSTEM WILL APPROACH TONIGHT AND SHOULD CLEAR THE SOUTHERN PLAINS BY SATURDAY AFTERNOON. THE OVERALL TREND WITH THIS SYSTEM...HAS BEEN BETTER CHANCES FOR PRECIPITATION MAINLY NORTH OF OKLAHOMA. WILL KEEP LOW CHANCES FOR LIGHT SNOW ACROSS NORTHERN OKLAHOMA FROM LATE TONIGHT THROUGH LATE SATURDAY MORNING. A WARM NOSE BELOW 7H ACROSS NORTHWEST OKLAHOMA MAY RESULT IN SOME SLEET OVERNIGHT. PRECIPITATION AMOUNTS WILL BE LIGHT WITH THIS SYSTEM. ANOTHER PUSH OF RATHER COLD AIR WILL BEGIN TO ENTER NORTHWEST OKLAHOMA LATE SATURDAY AFTERNOON AND EVENING. GUSTY NORTHERLY WINDS CAN BE EXPECTED ACROSS MOST OF OKLAHOMA BY EARLY/MID SUNDAY MORNING. AN APPROACHING WAVE WILL BRING A DECENT CHANCE OF LIGHT SNOW SUNDAY MORNING AND AFTERNOON. MOST MODELS INDICATE THE BEST LIFT OCCURRING ACROSS NORTHERN OKLAHOMA SUNDAY MORNING THEN SHIFTING SOUTHWARD DURING THE AFTERNOON. A LITTLE UNSURE ON AMOUNTS...BUT EXPECT SOME AREAS NORTH OF OF I-40 SHOULD SEE AN INCH OF SNOW WITH 2 INCH AMOUNTS POSSIBLE. WITH THE RECENT COLD WEATHER...ANY SNOW THAT FALLS WILL ACCUMULATE AND MAY CAUSE MINOR TRAFFIC DELAYS. LONG TERM...(MONDAY-THURSDAY) A GRADUAL WARMING TREND WILL BEGIN EARLY NEXT WEEK, WITH SURFACE WINDS BECOMING SOUTHERLY BY MIDWEEK. AN UPPER WAVE WILL MOVE ACROSS THE AREA ON THURSDAY, BRINGING LOW POPS FOR RAIN ACROSS SOUTHEAST OKLAHOMA. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM APPEARS TO BE WEAK, STALLING ACROSS NORTHWEST OKLAHOMA BEFORE LIFTING BACK TO THE NORTH. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 27 46 27 29 / 0 20 10 50 HOBART OK 28 48 27 29 / 10 10 10 40 WICHITA FALLS TX 29 53 32 33 / 0 10 10 30 GAGE OK 25 42 20 29 / 20 10 30 60 PONCA CITY OK 25 41 24 29 / 10 30 20 60 DURANT OK 28 45 34 39 / 0 10 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 04/17/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1157 PM EST FRI NOV 14 2014 .SYNOPSIS... THE ANOMALOUS UPPER TROUGH WILL BRIEFLY LIFT OUT OVER THE WEEKEND AS SURFACE HIGH PRESSURE SLIDES BY JUST TO THE SOUTH OF PENNSYLVANIA. AN EVEN DEEPER TROUGH WILL FORM OVER THE GREAT LAKES AND NORTHEAST CONUS EARLY NEXT WEEK. THIS DEEPENING TROUGH WILL HELP TO FORM A FAST MOVING AREA OF LOW PRESSURE THAT WILL TRACK FROM THE DEEP SOUTH TO THE SOUTHERN NEW ENGLAND COAST BY MONDAY EVENING. THIS WEATHER FEATURE WILL BRING A LIKELIHOOD OF A LIGHT TO MODERATE SNOWFALL MONDAY ACROSS AT LEAST THE NORTHWEST HALF OF PENNSYLVANIA. MIXED PRECIPITATION AND RAIN ARE MOST LIKELY OVER THE CENTRAL AND SOUTHEAST ON MONDAY. && .NEAR TERM /UNTIL 7 AM SATURDAY MORNING/... 10 PM UPDATE... SNOW SHOWERS ARE STILL MAINLY CELLULAR IN ONLY SEMI-CONCENTRATED BANDS. CELLS MOVING VERY QUICKLY AND CIGS GET HIGH PRETTY QUICKLY AWAY FROM THE LAKE. EVEN KERI IS HIGH-MVFR WHEN IT DOES SNOW THERE. THUS...ACCUMS FOR THE OVERNIGHT LOOK ON TRACK. AS EARLIER...HRRR AND RAP HANDLING THE NEAR-TERM WAGGLE TO THE SOUTH OF THE BROAD BANDS. THEY AND THE NEWEST NAM CONTINUE TO SINK THE BANDS SOUTHWARD FOR A FEW MORE HOURS...THEN STALL FOR A FEW HOURS AND SHOVE THEM BACK TO THE NORTH AS THE CENTER OF THE BIG SFC HIGH MOVES INTO THE CENTRAL APPALACHIANS. 730 PM UPDATE... HRRR AND RUC HANDLING THE SHIFT OF THE BANDS TO THE SOUTH WITH VEERING LOW LEVEL WINDS VERY NICELY. THE NEAR TERM PREDICTIONS PORTRAY THE CONTINUED VEERING THROUGH MIDNIGHT OR A LITTLE LATER...THEN A TURN AROUND AND BACKING TO A GENERALLY SWRLY FLOW IN THE CLOUD LAYER BY SUNRISE. THUS...HAVE HIGH CONFIDENCE IN KEEPING ALL THE WEATHER ELEMENTS VERY CLOSE TO CURRENT PROJECTIONS. LES ADVY STILL LOOKING GOOD FOR WARREN CO. PREV... A PERSISTENT...COLD NORTHWESTERLY FLOW OVR THE GRT LKS WILL CONTINUE TO PRODUCE FREQUENT SNOW SHOWERS ACROSS THE NW MTNS AND LAUREL HIGHLANDS TONIGHT WITH ADDITIONAL LIGHT ACCUMULATIONS OF A COATING TO ONE INCH ACROSS MANY AREAS NEAR...AND JUST TO THE WEST OF RT 219. HIGH RES MODELS SHOW DIRECTIONAL SHEAR IN THE LOWEST FEW KM BECOMING BETTER ALIGNED LATE THIS AFTERNOON THROUGH MUCH OF TONIGHT...WHICH WILL CREATE 2 OR 3...MORE ORGANIZED LES BANDS /THAT WILL PENETRATE FURTHER INLAND THANKS TO A MEAN 20KT FLOW FROM 300 DEG IN THE LOWEST 2 KM/. BRIEF PERIODS OF 1/4-1/2SM SNOW WILL OCCUR WITHIN THESE BANDS. EXTENDED THE LES ADVISORY FOR WARREN COUNTY THROUGH 12Z SATURDAY AS THE PASSAGE OF A WEAK UPPER SHORT WAVE AND SFC TROUGH WILL LEAD TO A BETTER UPSTREAM MOISTURE TAP OFF SOUTHERN LAKE HURON. AREAS OF MORE SHALLOW BKN-OVC STRATO CU ACROSS THE NORTH-CENTRAL MTNS AND CENTRAL RIDGE AND VALLEY REGION /INCLUDING THE SUSQ VALLEY/ WILL SUPPORT MAINLY FLURRIES AN PERHAPS A BRIEF 2-3SM VSBY SNOW SHOWER LATE TODAY AND TONIGHT WITH A FEW LOCATIONS SEEING A POWDERY DUSTING OF SNOW. MIN TEMPS EARLY SATURDAY WILL BE IN THE LOWER TO MID 20S...BUT THE WEST TO NORTHWEST BREEZE WILL DECREASE TO ABOUT 6-8 KTS AFTER 02Z SAT. && .SHORT TERM /7 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... EXPECT ANY REMAINING LAKE EFFECT SNOW BANDS TO SHIFT QUICKLY NORTH OR DISSIPATE DURING LATE MORNING/EARLY AFTERNOON HOURS AS SHEAR WITHIN THE SFC-800 INCREASES...BEFORE THE MEAN WIND IN THIS LAYER GRADUALLY BACKS TO THE WEST-SOUTHWEST IN THE AFTERNOON. ACROSS THE CENTRAL AND SERN ZONES...SOME MORNING CLOUDS AND FLURRIES WILL LIKELY YIELD TO INCREASING AMOUNT OF SUNSHINE THROUGH THE SHALLOW STRATO CU DECK. PARTLY TO MOSTLY CLOUDY SKIES IN THE FORM OF MAINLY ALTO CU CLOUDS EXPECTED FOR SAT NIGHT AS A WARM FRONT LIFTS NE FROM THE OHIO VALLEY. A BIT OF LIGHT SNOW OR FLURRIES IS POSSIBLE SAT NIGHT/EARLY SUNDAY ACROSS THE NW HALF OF THE STATE WITH VERY MINOR ACCUMS AT MOST. MAX TEMPS SAT WILL BE IN THE L-M 30S ACROSS THE NRN AND WRN MTNS...AND UPR 30S TO L40S FURTHER SE THROUGH THE SUSQ VALLEY. LOW TEMPS AT DAYBREAK SUNDAY WILL BE IN THE M-U 20S ACROSS THE MTNS AND 30-35 ELSEWHERE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... COLD WEATHER PATTERN CONTINUES THROUGH NEXT WEEK... ADVISORY LEVEL SNOW ACCUMULATION POSSIBLE ON MONDAY... UPPER LEVEL RIDGING FROM THE NW COAST TO ALASKA WILL SUSTAIN AND MAINTAIN A DEEP TROUGH AND UNSEASONABLY COLD AIRMASS OVER THE AREA THROUGH MUCH OF NEXT WEEK. FORECAST CONFIDENCE REMAINS VERY HIGH IN A PROLONGED STRETCH OF WELL-BELOW NORMAL TEMPERATURES FOR THIS TIME OF YEAR WITH THE CORE OF THE COLD IMPACTING THE CWA TUE-WED. MODELS CONTINUE TO SHOW A LEAD SHORTWAVE CROSSING THE ERN GREAT LAKES ON SUNDAY...WHICH COULD SPREAD SOME LIGHT SNOW/RAIN INTO THE WESTERN COUNTIES DURING THE DAY. RELOADING CENTRAL US TROUGH BECOMES WELL ESTABLISHED BY 12Z MONDAY WITH CORE OF NEGATIVE HEIGHT ANOMALIES /-3 STD/ SPREADING EWD FROM THE UPPER MIDWEST THROUGH THE OH VALLEY. THERE IS AN EMERGING CONSENSUS AMONG THE GLOBAL GUIDANCE IN A BROAD AREA OF PCPN OVERSPREADING THE AREA ON MONDAY...AS MOISTURE AND LIFT BECOME ENHANCED WITHIN THE ENTRANCE REGION OF A STRONG UPPER JET EAST OF THE DEEP TROUGH...ALONG SHARPENING LOW LEVEL THERMAL GRADIENT/FRONTAL AXIS MARKING LEADING EDGE OF ARCTIC AIRMASS. FOLLOWED WPC BLEND FOR QPF AND THERMAL PROFILES WHICH SUPPORTS POTENTIAL FOR ADVISORY LEVEL SNOW ACCUMULATIONS /2-4 INCHES/ OVER THE NW 1/2 OF THE CWA. FURTHER SOUTH/EAST...A RAIN TO SNOW MIX TO CHANGEOVER SCENARIO SEEMS LKLY WITH LOWER ACCUMS GIVEN INITIALLY WARM BLYR. ALTHOUGH THE PTYPE DETAILS AND SNOW ACCUMS ARE STILL UNCERTAIN...CONFIDENCE IN WINTER WEATHER IMPACTS TO THE MONDAY MORNING COMMUTE IS INCREASING ESPECIALLY OVER THE WRN 1/2 OF THE CWA. WILL ADD WORDING INTO THE HWO. A FRIGID SURGE OF ARCTIC AIR WILL BLAST INTO THE REGION BEHIND THIS SYSTEM ON TUESDAY AND PERSIST THRU THE MIDDLE OF NEXT WEEK. MEAN 85H TEMPS ARND -15C IN BOTH THE GEFS/ECENS TRANSLATE INTO HIGH TEMPS BELOW FREEZING FOR MOST OF CENTRAL PA TUE/WED. WIND CHILLS IN THE LOW TEENS AND SINGLE DIGITS ARE LKLY AND MAY EVEN DIP BELOW 0F OVER THE WRN MTNS. THE TRANSITION BACK TO A COLD CYCLONIC NW FLOW PATTERN WILL FAVOR LAKE EFFECT AND TERRAIN ENHANCED SNOW SHOWERS OVER THE NW MTNS WITH COLD AND DRY CONDITIONS FROM THE CENTRAL RIDGES INTO THE LWR SUSQ VLY. SOME MODERATION IN TEMPS MAY BE IN SIGHT BY THE END OF NEXT WEEK AS MODELS AND ENSEMBLES SHOW THE UPSTREAM PATTERN CONFIGURATION BREAKING DOWN. && .AVIATION /04Z SATURDAY THROUGH WEDNESDAY/... LITTLE CHANGE IS EXPECTED ACRS THE REGION TONIGHT AS COLD AIR RIDING SOUTHEAST ACROSS THE RELATIVELY WARMER WATERS OF THE GREAT LAKES IS LIFTED OVER THE HIGHER TERRAIN IN WESTERN PA. THE BIGGEST AVIATION CONCERN TONIGHT WILL BE THE LAKE ENHANCED SNOW SHOWERS ACROSS THE NORTHWEST MOUNTAINS. IT IS NOT PERSISTENT ENOUGH TO ALLOW FOR CIGS AND VSBYS TO REMAIN IFR...BUT CONDITIONS WILL DROP DOWN TO IFR BETWEEN 04Z TO 09Z...WHEN LAKE EFFECT SHOWERS WILL FADE AS WINDS SHIFT TO A MORE WESTERLY COMPONENT AND MOISTURE WILL BE CUT OFF. VFR TO HIGH-END MVFR STRATOCU AND SCT LIGHT SNOW SHOWERS/FLURRIES WILL SPILL INTO CENTRAL MTNS TONIGHT. WINDS WILL SETTLE TO 6-8 KTS TONIGHT. VFR WILL DOMINATE THE WEATHER PATTERN TOMORROW WITH ONLY POSSIBLE MVFR AT BFD...MAINLY TOMORROW NIGHT. OUTLOOK... SAT...AM SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD AND JST. SUN...SNOW SHOWERS/REDUCED VSBYS POSS AT KBFD. MON...LGT-MDT SNOW/LOW CIGS EXPECTED ACROSS THE NW HALF OF PA. RAIN/MIXED PRECIP AND LOW CIGS POSS SE. TUE AND WED...BLUSTERY AND VERY COLD WITH SNOW SHOWERS AND AREAS OF REDUCED CIGS/VSBYS - MAINLY ACROSS THE NW HALF OF PENN. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SATURDAY FOR PAZ004. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
253 AM MST SAT NOV 15 2014 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 253 AM MST SAT NOV 15 2014 MAIN CONCERN IN THE NEAR TERM IS ACCUMULATING SNOW ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINTER WEATHER ADVISORIES LOOK GOOD AND HAVE MADE NO CHANGES WITH THE MORNING FCST PACKAGE. HAVE SEEN A RELATIVE LULL IN SNOW SHOWERS OVERNIGHT WITH SUBSIDENCE AND SOMEWHAT DRY AIR ALOFT. HOWEVER...POTENT MIDLVL SHORTWAVE EVIDENT ON MORNING WATER VAPOR LOOP OVER THE PAC NW WILL MOVE SOUTHEAST TODAY. COOLING CLOUD TOPS OVER CENTRAL WY SUGGEST AN UPTICK IN PCPN COVERAGE OVER THE NEXT FEW HOURS...SO WILL KEEP CATEGORICAL POPS GOING. LOOKING AT TWO DISTINCT AREAS OF SNOW ACCUMULATIONS. FIRST ACROSS THE NORTHERN TIER OF COUNTIES WITH FRONTOGENESIS ALONG THE SFC FRONT. SECOND ALONG AND WEST OF THE LARAMIE RANGE WITHIN THE LEFT EXIT REGION OF A 105 KT H25 JET STREAK NOW ENTERING NORTHERN UT. BOTH AREAS COINCIDE WELL WITH A MIDLVL MOISTURE PLUME OVERSPREADING THE CWA. A GENERAL 2 TO 5 INCH SNOWFALL SEEMS PROBABLE IN THESE CORRIDORS. EVEN IF WE DO NOT SEE ADVISORY CRITERIA AMOUNTS...NORTHWEST WINDS WILL GUST IN EXCESS OF 30 MPH TODAY WHICH WILL CREATE BLOWING/DRIFTING. WEBCAMS ALREADY LOOK QUITE NASTY IN THE RAWLINS IN ELK MOUNTAIN AREAS AS OF 09Z THIS MORNING. THOUGHT ABOUT A TEMPORAL EXTENTION OF THE ADVISORY THROUGH THE AFTN FOR BLOWING SNOW AFTER ACCUMULATIONS END...BUT WILL LET THE DAY SHIFT MONITOR CONDITIONS TO SEE JUST HOW BAD VISIBILITY BECOMES LATER ON. SNOW HAS BEEN DIFFICULT TO COME BY IN THE CHEYENNE AREA SO FAR. IT STILL LOOKS LIKE WE HAVE A WINDOW OF OPPORTUNITY IN THE 12-15Z TIME FRAME AS THE NAM SHOWS A BAND OF MODERATE H7 FRONTOGENESIS FROM THE SOUTHERN LARAMIE RANGE EAST INTO KIMBALL COUNTY NE. MAY BE ENOUGH FOR A QUICK 1 TO 2 INCHES...BUT NOT MUCH MORE. WITH NORTHWEST WINDS GUSTING 25 TO 35 MPH...DAY SHIFT MIGHT NEED TO CONSIDER A BLOWING SNOW ADVISORY FOR CENTRAL AND EASTERN LARAMIE COUNTY. THE MOUNTAINS STILL LOOK PRIME FOR 8 TO 12 INCHES OF TOTAL ACCUMULATION. NVA WILL SPREAD ACROSS THE AREA BY LATE AFTN...SO EXPECT A GRADUAL DECREASE IN PCPN COVERAGE FROM NORTHWEST TO SOUTHEAST THROUGH EARLY EVE. DRY AFTER 00Z OUTSIDE OF A FEW FLURRIES. STRONG LLVL COLD AIR ADVECTION WILL CONTINUE TODAY WITH THE FROPA...WITH GFS H7 TEMPS PLUNGING TO THE -17C TO -20C RANGE BY 00Z SUN. SURFACE TEMPS WILL MOST LIKELY HOLD STEADY TODAY OR EVEN FALL SLIGHTLY INTO THE AFTN. DRYING ALOFT SIGNALS CLEARING INTO TONIGHT...AND WITH FRESH SNOWPACK COMES VERY COLD TEMPERATURES TONIGHT. GUSTY WEST WINDS MIGHT KEEP THINGS MIXED ENOUGH TO PREVENT TEMPERATURES FROM REALLY TANKING...BUT IT WILL BE SUFFICIENT FOR DANGEROUS WIND CHILLS BETWEEN -20 AND -30F. EXPECT WIND CHILL ADVISORIES WILL BE NECESSARY. BOTH THE NAM AND GFS SUGGEST A FAIRLY POTENT SHORTWAVE DIVING SOUTH ACROSS THE WESTERN DAKOTAS ON SUN AFTN. WHILE THIS DOES PROVIDE A REINFORCING SHOT OF COLD AIR...THE GOOD CAA DOES NOT ARRIVE UNTIL LATE. AS SUCH...EXPECT A PERIOD OF GUSTY WEST/DOWNSLOPE WINDS EAST OF THE LARAMIE RANGE TO CONTRIBUTE TO COMPRESSIONAL WARMING THROUGH EARLY AFTN. TRENDED HIGHER FOR MAX TEMPS BECAUSE OF THIS. MOISTENING ALOFT AND STRONG PVA SUGGESTS LIGHT SNOW SHOWERS ACROSS OUR NORTHERN AND EASTERN ZONES...SO ADDED LOW-END POPS THERE. COOLER FOR MON WITH CYCLONIC FLOW ALOFT AND SURFACE HIGH PRESSURE ENCOMPASSING MUCH OF THE CENTRAL AND NORTHERN ROCKIES. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 253 AM MST SAT NOV 15 2014 LONG TERM LOOKS DRY FOR THE MOST PART WITH TEMPERATURES BACK TO NEAR NORMAL FOR THIS TIME OF YEAR. WE STAY IN A NORTHWEST FLOW THAT COULD BRING SOME QUICK HITTING SNOW SHOWERS MOSTLY TO THE MOUNTAINS. THE MOST PROMINENT BEING THURSDAY. ECMWF ADVERTISING THIS WITH THE GFS SOLUTION ON THE SHORTWAVE FURTHER NORTH AND EAST OF OUR CWFA. DID KEEP SOME LOW CHANCE POPS IN THE FORECAST FOR THE MOUNTAINS. MOST OTHER PLACES DRY THROUGH FRIDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1023 PM MST FRI NOV 14 2014 BASED 06Z TERMINAL FORECASTS OFF THE LATEST HRRR FORECAST. STARTED LOWERING FLIGHT CONDITIONS A LITTLE EARLIER. CURRENT MOSAIC RADAR SHOWING SNOW SHOWERS MOVING INTO CARBON COUNTY...SO KRWL SHOULD BE COMING DOWN SOON. MORNING HOURS THROUGH 18Z WILL SEE THE MOST WIDESPREAD IFR/LIFR CONDITIONS ACROSS SOUTHEAST WYOMING AND NEBRASKA PANHANDLE WITH IMPROVING CONDITIONS AFTERWARDS. && .FIRE WEATHER... ISSUED AT 253 AM MST SAT NOV 15 2014 NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND. ANOTHER ARCTIC SYSTEM WILL BRING SNOW ACROSS MOST AREAS THROUGH SATURDAY. SEVERAL INCHES OF SNOW WILL ACCUMULATE...ESPECIALLY IN THE HIGHER ELEVATIONS OF SOUTHERN WYOMING. THIS SNOW WILL BE FOLLOWED BY BRISK SURFACE WIND AND COLD TEMPERATURES SUNDAY INTO SUNDAY NIGHT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR WYZ101>103-112-114. WINTER WEATHER ADVISORY UNTIL 1 PM MST THIS AFTERNOON FOR WYZ104>106-109>111-113-115>117. NE...WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR NEZ002- 095. && $$ SHORT TERM...CLH LONG TERM...GCC AVIATION...GCC FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1027 PM MST FRI NOV 14 2014 .UPDATE... ISSUED AT 934 PM MST FRI NOV 14 2014 04Z SFC ANALYSIS SHOWS COLD FRONT LOCATED FROM AROUND GUERNSEY EAST TO BETWEEN ALLIANCE AND HEMINGFORD. NORTH OF THE FRONT TEMPERATURES HAVE TUMBLED INTO THE TEENS...WITH 20S AND EVEN SOME 30S REMAINING SOUTH OF THE FRONT ALONG THE I-80 CORRIDOR. ALTHOUGH AREA RADAR BEAMS ARE OVERSHOOTING MUCH OF THE SNOW...WEBCAMS CONFIRM THAT SNOW WAS FALLING IN AREAS FROM GLENROCK EAST TO DOUGLAS...HARRISON AND CHADRON. ALTHOUGH ACCUMULATIONS APPEAR TO BE RELATIVELY LIGHT THUS FAR...PERHAPS UP TO AN INCH IN A FEW AREAS. BOTH 00Z NAM/GFS HAVE A GOOD HANDLE ON THIS 1-2 INCH SNOW BAND IN THIS AREA THRU MIDNIGHT. FRONT WILL SHIFT SOUTH OF THE CWFA THRU THE MORNING HOURS SATURDAY...CARRYING BEST FRONTAL FORCING WITH IT. AS SUCH...BAND OF HEAVIER SNOW WILL SPREAD SOUTH INTO THE REMAINDER OF THE AREA BY SUNRISE OR SHORTLY THEREAFTER. SNOW WILL BE OUT OF THE AREA BY EARLY AFTERNOON. DIDNT NEED TO MAKE ANY CHANGES TO CURRENT HIGHLIGHT PACKAGES...ALTHOUGH DID ADJUST SNOWFALL ACCUMS SLIGHTLY...DOWNWARD IN THE NORTH PLATTE RIVER VALLEY AND PERHAPS SLIGHTLY LESS ELSEWHERE AS WELL. ADDED BLOWING SNOW TO THE FORECAST AS WELL AS POST-FRONTAL NORTHERLIES WILL GUST TO 25-30 MPH AT TIMES...ESPECIALLY TOMORROW AFTERNOON. THE COMBINATION OF WINDS...SNOW AND SUB-ZERO WIND CHILLS WILL NOT MAKE FOR A DAY TO SPEND MUCH TIME OUTDOORS ON SATURDAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 357 PM MST FRI NOV 14 2014 COLD FRONT POISED JUST TO THE NORTH OF THE FORECAST AREA THIS AFTERNOON. UPPER LEVEL WESTERLY FLOW PARALLELING THE FRONT AND KEEPING IT FROM MAKING MUCH PROGRESS TO THE SOUTH. SNOW SHOULD BEGIN SPREADING EAST ACROSS CONVERSE/NIOBRARA COUNTIES BETWEEN 00Z-03Z/SAT AND INTO DAWES AND NORTHERN SIOUX COUNTIES IN THE NEBRASKA PANHANDLE BETWEEN 03Z-05Z/SAT. BOTH THE NAM12 AND HRRR KEEP THE SNOW CONFINED TO THESE AREAS THROUGH 06Z/SAT. ABOUT THAT TIME...MORE ROBUST BAND OF SNOW WILL BEGIN TO DEVELOP OVER CARBON COUNTY...ESPECIALLY ALONG THE INTERSTATE 80 CORRIDOR AND THE MEDICINE BOW AND SIERRA MADRE RANGES. STRONGER FRONTAL SURGE COMES AFTER ABOUT 08Z/SAT AND PUSHES TO THE SOUTHERN BORDER OF THE FORECAST AREA BY 13Z/SAT. BEST SNOWFALL ALONG AND EAST OF I-25 SHOULD COME WITH AND SHORTLY BEHIND THE FRONTAL PASSAGE. PLATTE...GOSHEN...AND LARAMIE COUNTIES ALONG WITH THE REMAINDER OF THE PANHANDLE SHOULD SEE 1 TO 3 INCH AMOUNTS. FRONTOGENETIC FORCING DOES FAVOR SOME ENHANCED LIFT IN LARAMIE COUNTY WHERE IMPACTS COULD STILL NECESSITATE AN UPGRADE TO A WINTER WEATHER ADVISORY. THE EVENING SHIFT WILL NEED TO MONITOR TRENDS FROM 00Z OUTPUT CLOSELY. IN ADDITION TO THE SNOW...NORTHERLY WIND OF 15 TO 30 MPH WILL PREVAIL FOLLOWING COLD FRONTAL PASSAGE. ELSEWHERE...ADVISORIES LOOK TO BE IN GOOD SHAPE WITH FORECAST STILL ON THE CORRECT TRACK. AIRMASS SLOWLY DRIES AFTER 18Z/SAT BUT ANY SUN WILL JUST ALLOW FOR COLD AIR STRATOCUMULUS TO DEVELOP. OVERALL... SHOULD BE A MOSTLY CLOUDY DAY. RAPID CLEARING WILL OCCUR AFTER SUNSET SATURDAY. GIVEN A FRESH SNOW COVER AND A LACK OF CLOUDS...WOULD NOT BE SURPRISED TO SEE TEMPERATURES DROP BELOW GUIDANCE. IN OUR FAVOR WOULD BE A CONTINUING WEST WIND IN SOME AREAS THAT WILL HELP KEEP THE BOUNDARY LAYER BETTER MIXED. THOSE AREAS LACKING WIND WILL UNDOUBTEDLY AGAIN SEE SUB-ZERO TEMPERATURES. NORTHERLY FLOW WILL BE REINFORCED SUNDAY AS 100KT+ JET DIVES SOUTH OUT OF SASKATCHEWAN. HIGH-AMPLITUDE RIDGE BUILDING ALONG THE WEST COAST WILL KEEP THE FORECAST AREA IN CYCLONIC FLOW THROUGH AT LEAST SUNDAY NIGHT. TAIL END OF SHORTWAVE ENERGY MOVING THROUGH THE NORTHERN PLAINS WILL BRUSH THE EASTERN TWO-THIRDS OF THE FORECAST AREA SUNDAY. THIS WILL BRING ADDITIONAL CLOUD COVER AND ANOTHER WEAK SHOT OF COLDER AIR. GUSTY NORTHWEST WIND 20 TO 30 MPH WILL MAKE FOR A RAW DAY EVEN WITH TEMPERATURES REBOUNDING FROM THE COLDER AIR OF SATURDAY AND SATURDAY NIGHT. LOW TEMPERATURES SUNDAY NIGHT WILL BE LARGELY DEPENDENT ON HOW MUCH CLOUD COVER REMAINS...ESPECIALLY OVER THE EASTERN PLAINS OF WYOMING AND THE PANHANDLE. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 357 PM MST FRI NOV 14 2014 LOOKS LIKE DRY NORTHWEST FLOW ALOFT OVER THE FORECAST AREA FOR MUCH OF THE EXTENDED. GRADIENT IS SUCH THAT BREEZY TO WINDY CONDITIONS WILL PERSIST EARLY IN THE EXTENDED PERIOD. SHORTWAVE RIDGE ALOFT DEPICTED FOR WEDNESDAY AND THURSDAY WITH WARMER TEMPERATURES. CANNOT RULE OUT A FEW SNOW SHOWERS OVER THE SNOWY AND SIERRA MADRE RANGES...POSSIBLY MORE SO FRIDAY WITH PASSAGE OF DEEPENING MID LEVEL TROUGH. WILL HAVE TO SEE HOW THIS TROUGH OR SHORTWAVE EVOLVES FOR LATE THURSDAY NIGHT INTO FRIDAY...BUT NO SIGNIFICANT STORM SYSTEMS DURING THIS PERIOD. TEMPERATURES SHOULD BE AROUND NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1023 PM MST FRI NOV 14 2014 BASED 06Z TERMINAL FORECASTS OFF THE LATEST HRRR FORECAST. STARTED LOWERING FLIGHT CONDITIONS A LITTLE EARLIER. CURRENT MOSAIC RADAR SHOWING SNOW SHOWERS MOVING INTO CARBON COUNTY...SO KRWL SHOULD BE COMING DOWN SOON. MORNING HOURS THROUGH 18Z WILL SEE THE MOST WIDESPREAD IFR/LIFR CONDITIONS ACROSS SOUTHEAST WYOMING AND NEBRASKA PANHANDLE WITH IMPROVING CONDITIONS AFTERWARDS. && .FIRE WEATHER... ISSUED AT 357 PM MST FRI NOV 14 2014 NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND. ANOTHER ARCTIC SYSTEM WILL BRING SNOW ACROSS MOST AREAS THROUGH SATURDAY. SEVERAL INCHES OF SNOW WILL ACCUMULATE...ESPECIALLY IN THE HIGHER ELEVATIONS OF SOUTHERN WYOMING. THIS SNOW WILL BE FOLLOWED BY BRISK SURFACE WIND AND COLD TEMPERATURES SUNDAY INTO SUNDAY NIGHT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR WYZ101>103- 112-114. WINTER WEATHER ADVISORY UNTIL 1 PM MST SATURDAY FOR WYZ104>106- 109>111-113-115>117. NE...WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR NEZ002-095. && $$ UPDATE...CAH SHORT TERM...RIW/ZF LONG TERM...RIW/CAH AVIATION...GCC FIRE WEATHER...RIW/ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
934 PM MST FRI NOV 14 2014 .UPDATE... ISSUED AT 934 PM MST FRI NOV 14 2014 04Z SFC ANALYSIS SHOWS COLD FRONT LOCATED FROM AROUND GUERNSEY EAST TO BETWEEN ALLIANCE AND HEMINGFORD. NORTH OF THE FRONT TEMPERATURES HAVE TUMBLED INTO THE TEENS...WITH 20S AND EVEN SOME 30S REMAINING SOUTH OF THE FRONT ALONG THE I-80 CORRIDOR. ALTHOUGH AREA RADAR BEAMS ARE OVERSHOOTING MUCH OF THE SNOW...WEBCAMS CONFIRM THAT SNOW WAS FALLING IN AREAS FROM GLENROCK EAST TO DOUGLAS...HARRISON AND CHADRON. ALTHOUGH ACCUMULATIONS APPEAR TO BE RELATIVELY LIGHT THUS FAR...PERHAPS UP TO AN INCH IN A FEW AREAS. BOTH 00Z NAM/GFS HAVE A GOOD HANDLE ON THIS 1-2 INCH SNOW BAND IN THIS AREA THRU MIDNIGHT. FRONT WILL SHIFT SOUTH OF THE CWFA THRU THE MORNING HOURS SATURDAY...CARRYING BEST FRONTAL FORCING WITH IT. AS SUCH...BAND OF HEAVIER SNOW WILL SPREAD SOUTH INTO THE REMAINDER OF THE AREA BY SUNRISE OR SHORTLY THEREAFTER. SNOW WILL BE OUT OF THE AREA BY EARLY AFTERNOON. DIDNT NEED TO MAKE ANY CHANGES TO CURRENT HIGHLIGHT PACKAGES...ALTHOUGH DID ADJUST SNOWFALL ACCUMS SLIGHTLY...DOWNWARD IN THE NORTH PLATTE RIVER VALLEY AND PERHAPS SLIGHTLY LESS ELSEWHERE AS WELL. ADDED BLOWING SNOW TO THE FORECAST AS WELL AS POST-FRONTAL NORTHERLIES WILL GUST TO 25-30 MPH AT TIMES...ESPECIALLY TOMORROW AFTERNOON. THE COMBINATION OF WINDS...SNOW AND SUB-ZERO WIND CHILLS WILL NOT MAKE FOR A DAY TO SPEND MUCH TIME OUTDOORS ON SATURDAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 357 PM MST FRI NOV 14 2014 COLD FRONT POISED JUST TO THE NORTH OF THE FORECAST AREA THIS AFTERNOON. UPPER LEVEL WESTERLY FLOW PARALLELING THE FRONT AND KEEPING IT FROM MAKING MUCH PROGRESS TO THE SOUTH. SNOW SHOULD BEGIN SPREADING EAST ACROSS CONVERSE/NIOBRARA COUNTIES BETWEEN 00Z-03Z/SAT AND INTO DAWES AND NORTHERN SIOUX COUNTIES IN THE NEBRASKA PANHANDLE BETWEEN 03Z-05Z/SAT. BOTH THE NAM12 AND HRRR KEEP THE SNOW CONFINED TO THESE AREAS THROUGH 06Z/SAT. ABOUT THAT TIME...MORE ROBUST BAND OF SNOW WILL BEGIN TO DEVELOP OVER CARBON COUNTY...ESPECIALLY ALONG THE INTERSTATE 80 CORRIDOR AND THE MEDICINE BOW AND SIERRA MADRE RANGES. STRONGER FRONTAL SURGE COMES AFTER ABOUT 08Z/SAT AND PUSHES TO THE SOUTHERN BORDER OF THE FORECAST AREA BY 13Z/SAT. BEST SNOWFALL ALONG AND EAST OF I-25 SHOULD COME WITH AND SHORTLY BEHIND THE FRONTAL PASSAGE. PLATTE...GOSHEN...AND LARAMIE COUNTIES ALONG WITH THE REMAINDER OF THE PANHANDLE SHOULD SEE 1 TO 3 INCH AMOUNTS. FRONTOGENETIC FORCING DOES FAVOR SOME ENHANCED LIFT IN LARAMIE COUNTY WHERE IMPACTS COULD STILL NECESSITATE AN UPGRADE TO A WINTER WEATHER ADVISORY. THE EVENING SHIFT WILL NEED TO MONITOR TRENDS FROM 00Z OUTPUT CLOSELY. IN ADDITION TO THE SNOW...NORTHERLY WIND OF 15 TO 30 MPH WILL PREVAIL FOLLOWING COLD FRONTAL PASSAGE. ELSEWHERE...ADVISORIES LOOK TO BE IN GOOD SHAPE WITH FORECAST STILL ON THE CORRECT TRACK. AIRMASS SLOWLY DRIES AFTER 18Z/SAT BUT ANY SUN WILL JUST ALLOW FOR COLD AIR STRATOCUMULUS TO DEVELOP. OVERALL... SHOULD BE A MOSTLY CLOUDY DAY. RAPID CLEARING WILL OCCUR AFTER SUNSET SATURDAY. GIVEN A FRESH SNOW COVER AND A LACK OF CLOUDS...WOULD NOT BE SURPRISED TO SEE TEMPERATURES DROP BELOW GUIDANCE. IN OUR FAVOR WOULD BE A CONTINUING WEST WIND IN SOME AREAS THAT WILL HELP KEEP THE BOUNDARY LAYER BETTER MIXED. THOSE AREAS LACKING WIND WILL UNDOUBTEDLY AGAIN SEE SUB-ZERO TEMPERATURES. NORTHERLY FLOW WILL BE REINFORCED SUNDAY AS 100KT+ JET DIVES SOUTH OUT OF SASKATCHEWAN. HIGH-AMPLITUDE RIDGE BUILDING ALONG THE WEST COAST WILL KEEP THE FORECAST AREA IN CYCLONIC FLOW THROUGH AT LEAST SUNDAY NIGHT. TAIL END OF SHORTWAVE ENERGY MOVING THROUGH THE NORTHERN PLAINS WILL BRUSH THE EASTERN TWO-THIRDS OF THE FORECAST AREA SUNDAY. THIS WILL BRING ADDITIONAL CLOUD COVER AND ANOTHER WEAK SHOT OF COLDER AIR. GUSTY NORTHWEST WIND 20 TO 30 MPH WILL MAKE FOR A RAW DAY EVEN WITH TEMPERATURES REBOUNDING FROM THE COLDER AIR OF SATURDAY AND SATURDAY NIGHT. LOW TEMPERATURES SUNDAY NIGHT WILL BE LARGELY DEPENDENT ON HOW MUCH CLOUD COVER REMAINS...ESPECIALLY OVER THE EASTERN PLAINS OF WYOMING AND THE PANHANDLE. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 357 PM MST FRI NOV 14 2014 LOOKS LIKE DRY NORTHWEST FLOW ALOFT OVER THE FORECAST AREA FOR MUCH OF THE EXTENDED. GRADIENT IS SUCH THAT BREEZY TO WINDY CONDITIONS WILL PERSIST EARLY IN THE EXTENDED PERIOD. SHORTWAVE RIDGE ALOFT DEPICTED FOR WEDNESDAY AND THURSDAY WITH WARMER TEMPERATURES. CANNOT RULE OUT A FEW SNOW SHOWERS OVER THE SNOWY AND SIERRA MADRE RANGES...POSSIBLY MORE SO FRIDAY WITH PASSAGE OF DEEPENING MID LEVEL TROUGH. WILL HAVE TO SEE HOW THIS TROUGH OR SHORTWAVE EVOLVES FOR LATE THURSDAY NIGHT INTO FRIDAY...BUT NO SIGNIFICANT STORM SYSTEMS DURING THIS PERIOD. TEMPERATURES SHOULD BE AROUND NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 357 PM MST FRI NOV 14 2014 VFR CONDITIONS EXPECTED AT ALL TERMINALS UNTIL ABOUT 02Z/SAT. FIRST SURGE OF COLDER AIR WILL BEGIN TO GENERATE LIGHT SNOW GENERALLY ALONG AND NORTH OF A KDGW-KCDR LINE BETWEEN 02Z-05Z. CONDITIONS WILL BECOME MVFR AND EVENTUALLY IFR BY 06Z/SAT AT KCDR. KAIA AND KBFF WILL BEGIN TO GET IN ON THE ACTION WITH MVFR EXPECTED AROUND 06Z/SAT AS THE AREA OF LIGHT SNOW SAGS SLOWLY SOUTH. ABOUT THE SAME TIME... APPEARS THAT A BETTER BAND OF SNOW WILL EXTEND EAST INTO CARBON COUNTY AND IMPACT KRWL BY 08Z/SAT. A SECOND WAVE OF SNOW WILL THEN DEVELOP AS A STRONGER FRONTAL SURGE TRAVERSES THE FORECAST AREA FROM NORTH TO SOUTH FROM 08Z TO 13/SAT. GUSTY NORTHERLY WIND OF 15-30KTS WILL ACCOMPANY AND FOLLOW FRONTAL PASSAGE. IFR AND LIFR CONDITIONS WILL BE WIDESPREAD WITH THE HEAVIEST SNOWFALL LIKELY TO OCCUR BETWEEN ABOUT 10Z-15Z/SAT. DRIER CONDITIONS SHOULD BEGIN TO PUSH ACROSS THE FORECAST AREA FROM NORTH-TO-SOUTH BETWEEN 15Z-20Z/SAT. THERE SHOULD BE ENOUGH COLD AIR ALOFT THAT ANY PARTIAL CLEARING WILL ALLOW FOR STRATOCUMULUS TO FORM...ALTHOUGH CONDITIONS SHOULD BE VFR AFTER ABOUT 19Z/SAT. MOUNTAIN OBSCURATIONS WILL BE WIDESPREAD FROM SHORTLY AFTER 00Z/SAT UNTIL ABOUT 18Z/SAT. MOUNTAIN TOP OBSCURATIONS WILL CONTINUE AFTER THAT TIME UNTIL SUNSET LATE SATURDAY AFTERNOON. && .FIRE WEATHER... ISSUED AT 357 PM MST FRI NOV 14 2014 NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND. ANOTHER ARCTIC SYSTEM WILL BRING SNOW ACROSS MOST AREAS THROUGH SATURDAY. SEVERAL INCHES OF SNOW WILL ACCUMULATE...ESPECIALLY IN THE HIGHER ELEVATIONS OF SOUTHERN WYOMING. THIS SNOW WILL BE FOLLOWED BY BRISK SURFACE WIND AND COLD TEMPERATURES SUNDAY INTO SUNDAY NIGHT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR WYZ101>103- 112-114. WINTER WEATHER ADVISORY UNTIL 1 PM MST SATURDAY FOR WYZ104>106- 109>111-113-115>117. NE...WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR NEZ002-095. && $$ UPDATE...CAH SHORT TERM...RIW/ZF LONG TERM...RIW/CAH AVIATION...RIW/CAH FIRE WEATHER...RIW/ZF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
444 AM MST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 412 AM MST SAT NOV 15 2014 ...MORE SNOW AND ARCTIC AIR ON THE WAY... CURRENTLY... THE LEADING EDGE OF THE NEXT ARCTIC INTRUSION WAS ALONG THE CO/WY BORDER AND IT WAS HEADING SOUTH. CLOSER TO HOME...TEMPERATURES AT 3 AM VARIED CONSIDERABLY ACROSS THE PLAINS...AS ELEVATIONS GENERALLY ABOVE 6000 FEET WERE IN THE RELATIVELY WARMER AIR (30S AND 40S) WHILE AREAS BELOW 6000 WERE IN THE TEENS AND 20S. IN THE MTNS AND VALLEYS...IT WAS RELATIVELY WARM WITH TEMPS IN THE 20S AND 30S. RADAR...OBS AND WEB CAMS INDICATED THAT SNOW STILL OCCURRING OVER THE CONTDVD. TODAY... WEATHER WILL BE QUITE ACTIVE DURING THE NEXT 24. HRRR INDICATES THAT THE LEADING EDGE OF THE ARCTIC AIR WILL MOVE INTO EL PASO COUNTY AROUND 9-10 AM AND WILL PROGRESS SOUTH...REACHING THE NEW MEXICO BORDER BY 3 PM. LIKEWISE...MAX TEMPS TODAY WILL LIKELY OCCUR THIS MORNING ACROSS THE PIKES PEAK REGION AND MIDDAY ACROSS THE REST OF THE REGION. TEMPS WILL QUICKLY FALL AFTER THE ARCTIC FRONT GOES BY. AS FOR PRECIP...IN THE MTNS...STEADY SNOW...SOME HEAVY...WILL CONTINUE ACROSS THE CENTRAL MTNS ALL DAY TODAY. SNOW ACROSS THE SAN JUANS WILL DECREASE LATER THIS MORNING BUT WILL RAMP UP ONCE AGAIN BY MID AFTERNOON. PRECIP ON THE PLAINS WILL GENERALLY DEVELOP ACROSS THE PIKES PEAK REGION SHORTLY AFTER NOON AND WILL PICK UP AS THE AFTERNOON PROGRESSES. STEADY SNOW WILL LIKELY BE ONGOING BY LATE AFTERNOON ACROSS EL PASO COUNTY AND TRAVEL WILL ONCE AGAIN BECOME DIFFICULT ACROSS THIS REGION. WINDS WILL LIKELY BE A BIT GUSTY SO AREAS OF BLOWING SNOW WILL OCCUR. BY LATE AFTERNOON THE SNOW WILL DEVELOP FARTHER SOUTH DOWN THE I-25 CORRIDOR AND EASTERN MTN REGION. OTHERWISE...THE REST OF THE PLAINS WILL LIKELY REMAIN DRY. TONIGHT... MAIN CONCERN DURING THIS PERIOD IS THE SPANISH PEAKS/RATON MESA/WET MTNS REGION AS ALL GUIDANCE IS SHOWING PRETTY HEALTHY QPF BULLSEYES OVER THIS REGION. FOR NOW I HAVE ISSUED A WINTER WEATHER ADVISORY FOR THIS REGION WITH THE AREA LIKELY RECEIVING 3-6 INCHES OF SNOW AT THE LOWER ELEVATIONS OF LAS ANIMAS AND HUERFANO COUNTIES WHILE HIGHER ELEVATIONS WILL LIKELY RECEIVE 4 TO 10 INCHES OF SNOW. IT IS POSSIBLE THAT THESE VALUES MAY BE ON THE LOW SIDE...ESPECIALLY IF GUIDANCE DOES VERIFY. WILL ALLOW LATER SHIFT TO REANALYZE AND UPGRADE TO WARNING STATUS IF LATER SIMULATIONS SHOW LARGE QPF VALUES OVER AFOREMENTIONED REGION. FOR THE REST OF THE PLAINS...EL PASO COUNTY SHOULD GENERALLY RECEIVE ABOUT 2-4" OF SNOW WITH THIS EVENT WITH 2-6 IN TELLER COUNTY AND PIKES PEAK. PUEBLO/FREMONT COUNTIES WILL LIKELY RECEIVE ANYWHERE FROM BETWEEN 2 AND 5 INCHES. OVER THE FAR EAST PLAINS...1 TO 2 INCHES WILL BE POSSIBLE. THE MOUNTAINS WILL CONTINUE TO SEE SNOW...HOWEVER THE SNOW WILL END FROM S TO N ACROSS THE C MTNS LATER TONIGHT. OVERALL ANOTHER 6 TO 12 INCHES OF SNOW IS LIKELY OVER THE CONTDVD REGION TEMPS TONIGHT WILL BE COLD ONCE AGAIN ACROSS THE ENTIRE REGION. SINGLE DIGITS WILL OCCUR ACROSS NEARLY ALL OF THE REGION EXCEPT TEENS MAINLY IN THE SAN LUIS VALLEY. /HODANISH .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 412 AM MST SAT NOV 15 2014 ...COLD SUNDAY THEN GRADUAL WARMING... SNOW WILL LINGER ALONG THE SOUTHERN BORDER AREAS EARLY SUNDAY...BUT SHOULD MOSTLY END BY NOON AS PROGRESSIVE SHORTWAVE MOVES ON THROUGH. NEW SHOT OF ARCTIC AIR WILL BRING ONE MORE REALLY COLD DAY SUNDAY BUT THEN THINGS WILL START TO WARM UP AND DRY OUT FOR MOST OF THE UPCOMING WEEK. THE WARM UP MAY START A LITTLE SLOW ON MONDAY AS SNOW COVER AND LIGHT PRESSURE GRADIENTS WILL TEND TO KEEP SURFACE INVERSIONS IN PLACE THROUGH THE DAY. BY TUESDAY...IT LOOKS LIKE WE SHOULD SEE A LITTLE BETTER MIXING AS DOWNSLOPE PRESSURE GRADIENTS DEVELOP. THIS SHOULD HELP BRING CHINOOK BREEZES OFF THE MOUNTAINS TO START WARMING THE AIR. COULD BE A LITTLE SET BACK WEDNESDAY AS THE MODELS ARE SHOWING A WEAK SURFACE HIGH DROPPING THROUGH THE PLAINS THIS DAY. THIS COULD REESTABLISH INVERSIONS IF THERE IS ENOUGH COOLING WITH THE HIGH AND IF THERE IS ANY SNOW COVER REMAINING. THURSDAY AND ESPECIALLY FRIDAY...IT LOOKS LIKE SOME WEAK ENERGY FROM THE PACIFIC WILL START MOVING BACK INTO THE REGION. THIS ENERGY COULD SPREAD SOME SNOW SHOWERS INTO THE CONTINENTAL DIVIDE THURSDAY...AND EAST TO THE REST OF THE MOUNTAINS AND PIKES PEAK REGION ON FRIDAY. THE APPROACHING ENERGY DOESN`T LOOK STRONG AT THIS POINT SO FORECAST CONFIDENCE IS LOW AT THIS TIME. TEMPERATURES WILL LIKELY REMAIN MILD THURSDAY...BUT THEN START TO COOL ON FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 412 AM MST SAT NOV 15 2014 KCOS...ARCTIC FRONT WILL CROSS KCOS AOA NOONTIME...18-19Z. WINDS WILL SHIFT TO NORTH THAN NORTH-NORTHEAST AND BECOME GUSTY. COULD SEE SOME SNOW SHOWERS BY MID AFTERNOON BUT EXPECT BRUNT OF IT WILL OCCUR MORE TOWARDS SUNSET. LIFR CONDITIONS WILL BE POSSIBLE/LIKELY BETWEEN 00Z-09Z AS STEADY SNOW IS EXPECTED. KPUB...ARCTIC FRONT WILL CROSS KPUB AOA 19-20Z WITH WINDS QUICKLY SHIFTING TO THE NORTHEAST AND THEN EAST. PRECIP WILL LIKELY DEVELOP AFTER SUNSET AND THERE IS A HIGH PROBABILITY THAT IT WILL SNOW...AND IT IS EXPECTED TO ACCUMULATE TO 2-4 INCHES. LIFR CONDITIONS LIKELY ONCE SNOW STARTS. IT WILL LAST THROUGH THE NIGHT ENDING AROUND SUNRISE. KALS...LOW CIGS THIS MORNING SHOULD BREAK UP ABOUT 1-2HRS AFTER SUNRISE AS WEST WINDS INCREASE. VFR EXPECTED THROUGH THE REST OF THE DAY WITH PRECIP DEVELOPING AFTER MIDNIGHT. SNOW WILL LIKELY ACCUMULATE AT KALS WITH 1-2" ANTICIPATED. CIGS LIKELY WILL GO LIFR AFTER MIDNIGHT. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 9 AM MST SUNDAY FOR COZ072>075-079-080-087-088. WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR COZ073-075. && $$ SHORT TERM...HODANISH LONG TERM...LW AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
539 AM CST SAT NOV 15 2014 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 303 AM CST SAT NOV 15 2014 NO MAJOR CHANGES WITH ONGOING FORECAST FOR THE FIRST SIGNIFICANT SNOWFALL OF THE SEASON AS MODELS REMAIN IN GOOD AGREEMENT WITH EXPECTED SNOW TODAY. USED A BLEND OF THE HRRR/HOPWRF FOR TIMING OF PRECIP AND NAM/ECMWF TEMPS. BROAD ISENTROPIC LIFT AND DECENT MOISTURE TRANSPORT DEVELOP OVER WESTERN TO NORTHWEST IOWA THIS MORNING AND QUICKLY BLOSSOMS ACROSS THE REMAINDER OF THE STATE THIS AFTERNOON. ONE MINOR CHANGE WAS START THE SNOW A LITTLE SOONER THIS MORNING OVER THE WEST TO NORTHWEST AS SNOW ALREADY DEVELOPING ALOFT AND SNOW SHOULD START REACHING THE SURFACE BETWEEN 12-14Z THIS MORNING. THE 15.03Z HOPWRF AND 15.05Z HRRR HAVE SNOW MOVING INTO THE WESTERN EDGES OF THE FORECAST AREA BETWEEN 13-15Z. THE FORECAST SOUNDINGS ACROSS NORTHERN IOWA BECOME COMPLETELY SATURATED BY 17-18Z TODAY AND THE STRONGER OMEGA IS JUST AT THE TOP EDGE OF THE DENDRITIC LAYER BUT ENOUGH OVERLAP TO SEE SOME DECENT FLAKES...AND THUS SLIGHTLY HIGHER SNOW ACCUMULATION THIS AFTERNOON OVER NORTHERN IOWA. RAP IS A BIT LESS WITH THE FORCING THAN THE NAM/GFS AND HAS SLIGHTLY LOWER SNOW AMOUNTS GOING...BUT STILL DEPICTS ENOUGH SNOW TO WARRANT ADVISORY. FURTHER SOUTH...SOUNDINGS NOT TOO DISSIMILAR THAN NORTHERN IOWA...WITH THE MAIN DIFFERENCE BEING JUST SLIGHTLY LESSER FORCING WITHIN THE DENDRITIC LAYER. THIS RESULTING IN LESS SNOW AMOUNTS OVER THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA. LEANED TOWARD A BLEND OF THE WARMER NAM/ECMWF FOR TEMPERATURES TODAY. THIS RESULTED IN SNOW RATIOS AROUND 17:1 TO 18:1 OVER NORTHERN IOWA AND 15:1 TO 16:1 ACROSS THE SOUTH...BASED ON 925M TO 700MB THICKNESS. HAVE 100 POPS GOING MUCH OF THE AFTERNOON WITH HIGH CONFIDENCE ALL OF CENTRAL IOWA WILL BE SNOWING BY OR SHORTLY PAST 18Z. VERY LITTLE WIND TODAY BUT WITH THE FLUFFY SNOW TYPE EXPECTED AND AT TIMES FALLING MODERATELY...THIS SHOULD BE ENOUGH TO CAUSE SOME VISIBILITY RESTRICTION WITH A 6-9 KNOT WIND. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 303 AM CST SAT NOV 15 2014 ACTIVE WEATHER WILL CONTINUE THROUGH THE WEEKEND AND EARLY NEXT WEEK FOLLOWING TONIGHTS SYSTEM...ANOTHER INTENSE UPPER LEVEL LOW WILL DROP SOUTH INTO THE NORTHERN GREAT LAKES SUNDAY NIGHT AND MONDAY MORNING. TONIGHT...SYSTEM EXITING THE AREA TO THE EAST DURING THE EVENING HOURS. BEST FORCING ALONG H500 AND SFC TROUGH NEAR 00Z FOCUSING ON H700 BOUNDARY ACROSS NORTHERN IOWA. THROUGH 06Z THIS H700 BOUNDARY PUSHES EAST WITH TROUGH RESULTING IN LESSENING FORCING WEST OF I35 DURING THE LATE EVENING. BY 12Z BEST FORCING EAST OF THE AREA WITH SOME RESIDUAL LIGHT SNOW/FLURRIES OVER THE NORTHEAST ENDING QUICKLY WITH CLOUDS DEPARTING IN THE MORNING SUNDAY. SNOW RATIOS OF 18 TO 20:1 AND EXPECTED QPF AMOUNT YIELD SNOWFALL AMOUNTS OF UP TO ANOTHER 1.5 INCHES TONIGHT DURING THE EVENING AND OVERNIGHT HOURS. FORTUNATELY THE WINDS WILL BE LIGHT DURING THE EVENT...SO BLOWING SNOW WILL NOT BE AN ISSUE TONIGHT. WITH CLEARING BY MORNING...LOWS WILL QUICKLY FALL NORTHWEST AND WEST INTO THE SINGLE DIGITS WITH TEENS I35 EAST. SUNDAY WILL INITIALLY SEE SOME SUNSHINE BETWEEN WAVES BUT CLOUDS WILL INCREASE WEST DURING THE AFTERNOON. WITH H850 TEMPS IN THE -10C TO -12C RANGE AND WESTERLY WINDS...TEMPERATURES WILL BE TOLERABLE IN THE MID 20S OVER MOST OF THE AREA. AN APPROACHING COLD FRONT WILL SPREAD CLOUDS ACROSS THE REGION THROUGH EARLY EVENING. THE SECOND STRONG H500 LOW WILL FORCE A BULGE OF COLD AIR QUICKLY SOUTHEAST INTO WESTERN IOWA SUNDAY EVENING WITH RATHER STRONG COLD AIR ADVECTION AND INCREASING WINDS ALOFT. BY 12Z H850 TEMPS WILL HAVE FALLEN ANOTHER 8 TO 10C WITH READINGS FROM -16C TO -20C. THROUGH THE DAY MONDAY CLOUD COVER WILL OVERTAKE THE AREA WITH H850 TEMPS SETTLING TOWARD -18C TO -20C REGION WIDE. MODELS HAVE BEEN CONSISTENT WITH STEEPENING LAPSE RATES NEAR 15Z AND STRONG MIXING THROUGH THE DAY...POTENTIAL FOR SNOW SHOWERS ACROSS THE NORTHEAST WITH FLURRIES CENTRAL AND SOUTH. ALL IN ALL...MONDAY IS LOOKING RATHER UNPLEASANT. POTENTIAL FOR 15 TO 25 MPH WINDS WITH GUSTS TO NEAR 35 MPH AT TIMES. THIS WILL CAUSE PATCHY TO AREAS BLOWING SNOW OVER MUCH OF THE NORTHEAST HALF OF THE AREA WITH REDUCTIONS TO VISIBILITY. HEADLINES MAY BE NEEDED AGAIN ON MONDAY FOR THE COMBINATION OF WIND...BLOWING SNOW...AND COLD. HAVE EXPANDED THE POTENTIAL FOR LIGHT PRECIP AND BLOWING SNOW MONDAY ACROSS THE AREA. HIGHS WILL RECOVER LITTLE FROM FRIGID MORNING LOWS IN THE SINGLE DIGITS TO LOWER TEENS. BY AFTERNOON HIGHS NORTH WILL REACH THE LOWER TEENS TO THE LOWER 20S IN THE SOUTHEAST. TO TOP OFF THE WONDERFUL DAY...MINIMUM RECORD HIGHS LOOK LIKELY TO BE SET AT MANY LOCATIONS...ONE WHICH HAS NOT BEEN SEEN SINCE THE 1890S AND MANY SINCE THE 1950S. IN FACT...OUR HIGHS MONDAY WOULD STILL BE ABOUT 10 TO 15 DEGREES BELOW OUR COLDEST AVERAGE HIGHS FOR THE NORMALLY COLDEST WINTER DAY OF THE YEAR...OR ABOUT 30 DEGREES BELOW OUR NORMAL FOR 11/17. WE HAVENT HAD HIGHS THIS COLD SINCE EARLY MARCH OF 2014. TUESDAY WILL BEGIN QUITE COLD WITH A RIDGE JUST EDGING INTO THE AREA BUT WARM BY AFTERNOON. QUICKLY ANOTHER CLIPPER OVER THE NORTHERN PLAINS WILL MODERATE THE AIRMASS WITH BRISK WEST WINDS DEVELOPING DURING THE DAY. TEMPS WILL RISE INTO THE 20S. ANOTHER ARCTIC FRONT WILL DROP SOUTH INTO THE AREA TUESDAY NIGHT BUT THE AIRMASS WILL NOT BE QUITE AS COLD AS THE PREVIOUS. THE REMAINDER OF THE WEEK FEATURES A SERIES OF ARCTIC SHORT WAVES ROTATING AROUND THE HUDSON BAY PARENT H500 LOW...PULLING ADDITIONAL COLD AIR TOWARD THE GREAT PLAINS. NEXT WEEK WILL FEATURE DAYS WITH CLOUD COVER MIXED WITH SOME SUNSHINE AND CHILLY READINGS. FORTUNATELY BY LATE IN THE EXTENDED...TOWARD SATURDAY THE CROSS POLAR FLOW CUTS OFF...THE H500 RIDGE ACROSS THE WEST COAST BREAKS DOWN AND MORE ZONAL FLOW RESULTS OVER THE ROCKIES. THIS WILL CAUSE CHINOOK COMPRESSIONAL HEATING OVER THE PLAINS AND MODERATE HIGHS TO ABOVE FREEZING. FROM WEDNESDAY THROUGH FRIDAY HIGHS WILL APPROACH THE 30 DEGREE MARK WITH LOWS MODERATING INTO THE TEENS OVER THE AREA. LITTLE PRECIPITATION IS EXPECTED FOR MUCH OF THE PERIOD NEXT WEEK. && .AVIATION...15/12Z ISSUED AT 536 AM CST SAT NOV 15 2014 MVFR CONDITIONS WILL QUICKLY MOVE IN WITH THE SWATH OF SNOW LATE THIS MORNING CONTINUE THROUGH THE AFTERNOON HOURS. HAVE IFR CONDITIONS MENTIONED THIS AFTERNOON DURING THE HIGHER SNOWFALL RATES ANTICIPATED. HIGHER CONFIDENCE TO MENTION IFR CIGS THIS AFTERNOON AND KEPT MVFR CIGS THROUGH THE END OF THE TAF PERIOD. SNOW SHOULD END BY 06Z TONIGHT...IF NOT SOONER FROM WEST TO EAST HELPING TO IMPROVE VISIBILITY. && .DMX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE- BREMER-BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-CRAWFORD- DALLAS-DAVIS-DECATUR-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE- HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-LUCAS-MADISON- MAHASKA-MARION-MARSHALL-MONROE-PALO ALTO-POCAHONTAS-POLK- POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN- WAYNE-WEBSTER-WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
447 AM MST SAT NOV 15 2014 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 404 AM MST SAT NOV 15 2014 MAIN FORECAST CONCERN WILL BE WINTER WEATHER EVENT OCCURRING THROUGH TONIGHT. SATELLITE CONTINUING TO SHOW AN AMPLIFIED PATTERN FROM THE EASTERN PACIFIC INTO EASTERN NORTH AMERICA. CURRENTLY NEARLY ZONAL FLOW OVER OUR AREA WITH MULTIPLE SMALL SCALE WAVES EMBEDDED WITHIN THAT FLOW. STRONG...COLD AND RATHER COMPLEX UPPER TROUGH IS MOVING THROUGH THE NORTH CENTRAL OF THE COUNTRY. SATELLITE ALSO SHOWING DRY MID LEVEL AIR MASS IN PLACE AHEAD OF INCOMING NORTHERN TROUGH. ANOTHER STRONG COLD FRONT IS APPROACHING FROM THE NORTH. AT JET LEVEL...MODELS LOOKED LIKE THEY INITIALIZED FINE. AT MID LEVELS...THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF AND CANADIAN. THE SREF WAS DOING THE BEST AT THE SURFACE. ALL THE MODELS WERE OKAY ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...THE DAY STARTS OUT WITH AREA IN SUBSIDENCE FROM DEPARTING JET. AFTER THIS MODELS DISAGREE WHERE THE MAIN JET ENERGY WILL BE THROUGH THE REST OF THE PERIOD. BY 18Z IT LOOKS LIKE A LEFT FRONT QUADRANT WILL BEGIN AFFECTING THE AREA. BY LATE IN THE AFTERNOON INTO THE EVENING...THERE MAY BE A RIGHT REAR QUADRANT ACROSS THE SOUTHEASTERN PORTION OF THE AREA. AFTER THAT THE JET IS WELL SOUTH. CURRENTLY INITIAL SHORTWAVE TROUGH IS MOVING THROUGH AND PRODUCING LIGHT SNOW OVER SOUTHERN AND EASTERN SECTIONS. MODELS HAVE A GOOD HANDLE ON THIS INITIAL SHORTWAVE TROUGH. CURRENT RADAR SHOWS THAT THE MOST INTENSE SNOWFALL IS TO THE SOUTH OF AREA AND MOVING THROUGH RATHER QUICKLY. ALL NIGHT THE HRRR HAS BEEN CATCHING THE CURRENT RADAR TRENDS EXTREMELY WELL AND IT ALSO MATCHES UP WELL WITH THE ABOVE MENTIONED MID AND UPPER LEVEL LIFT. OTHER OUTPUT IS TOO FAR NORTH WITH THE PRECIPITATION SHIELD. SO WILL LEAN HEAVILY ON THE HRRR FOR PRECIPITATION EARLY ON AND THEN TREND MORE TOWARD THE CANADIAN/ECMWF AFTER THAT. SO LITTLE TO NO SNOW FALL WILL END UP FALLING OVER THE WESTERN HALF TO TWO THIRDS THIS MORNING WITH MOST OF THE SNOW OCCURRING IN THE EASTERN SIX COUNTIES THROUGH MID MORNING. UPSTREAM SATELLITE IS SHOWING A CLEARING TREND BEHIND THIS EXITING SHORTWAVE AND A DRY AIR MASS IN ADVANCE OF THE NEXT SHORTWAVE TROUGH. AFTER THE SNOW ENDS THIS MORNING...THE NEXT BATCH OF LIGHT SNOW WILL DEVELOP TO OUR NORTH AND NORTHWEST BY LATE IN THE MORNING TO EARLY AFTERNOON. THIS AREA THEN MOVES ACROSS THE AREA THROUGH THE REST OF THE NIGHT WITH THE MOST SNOWFALL OCCURRING BEFORE MIDNIGHT. IT IS POSSIBLE THAT SOME LOCATIONS MAY NOT SEE ANY SNOW UNTIL LATER THIS AFTERNOON TO EARLY THIS EVENING. MODELS...ESPECIALLY THE GFS...TEND TO BE TOO DEEP WITH THE MOISTURE AND THEREFORE OVERPRODUCES PRECIPITATION. THE DRIER AIR MASS UPSTREAM MAKES SENSE SINCE MOISTURE IN THE WESTERLY FLOW ALOFT IS GETTING WRUNG BY THE HIGHER TERRAIN OVER COLORADO. SO PER THE REASONING GIVEN ABOVE...SNOWFALL AMOUNTS WILL BE MUCH LIGHTER THAN PREVIOUSLY EXPECTED WITH TOTAL AMOUNTS NOW ANTICIPATED TO BE AROUND AN INCH OR LESS. IT IS ALSO POSSIBLE THAT WHEN THE COLD FRONT MOVES THROUGH LATER TODAY...THAT LITTLE IF ANY SNOW WILL BE ON THE GROUND. ALSO CONSIDERING WHAT LITTLE SNOW HAS ALREADY FALLEN AND THAT THERE WILL BE A SIGNIFICANT LULL BEFORE THE NEXT SNOWFALL STARTS...HAVE DECIDED TO CANCEL THE WINTER WEATHER ADVISORY. IF SNOWFALL ENDS UP BEING WORSE THAN CURRENTLY EXPECTED...THEN A MORE SHORT TERM ADVISORY CAN BE ISSUED TO HANDLE THAT SINCE NOTHING IS GOING ON AT THIS TIME. NOW FOR TEMPERATURES. JUST LIKE LAST NIGHT...MODELS ARE TOO COOL WITH THE CURRENT TEMPERATURES DUE TO CLOUD COVER AND CONTINUED WARM AIR ADVECTION. FRONT IS ALSO EXPECTED TO ARRIVE LATER AND WILL NOT MOVE THROUGH THE EASTERN PORTION OF THE AREA UNTIL THIS AFTERNOON. THERE ALSO MAY BE ENOUGH BREAKS IN THE CLOUD COVER TO ALLOW SOME SUNSHINE TO OCCUR. A LOT OF THE OUTPUT IS SAYING WARMER AND TRENDED IN THAT DIRECTION. SUNDAY/SUNDAY NIGHT...DRY CONDITIONS EXPECTED THROUGH THE PERIOD. SHOULD SEE A DECENT AMOUNT OF SUN WITH WINDS BEING MOSTLY FROM A DOWNSLOPE DIRECTION. MODELS ARE SHOW TEMPERATURES WARMER THAN YESTERDAY. MODELS HAVE HAD A RECENT COOL BIAS AS WELL. SO WENT NEAR THE WARMER GUIDANCE. MONDAY/MONDAY NIGHT...STRONG UPPER SYSTEM DIGS INTO THE NORTH CENTRAL PORTION OF THE COUNTRY JUST BEFORE AND DURING THIS PERIOD. THIS PUSHES ANOTHER COLD FRONT THROUGH THE AREA AND SHOULD MAKE FOR COOLER TEMPERATURES COMPARED TO SUNDAY MAXES. HOWEVER...THERE IS A BIG DIFFERENCE IN THE AMOUNT OF COOLING INDICATED BY THE MODELS. DID NOT GO WITH THE COLDEST GUIDANCE BUT TRENDED IN THE COLDER DIRECTION. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 404 AM MST SAT NOV 15 2014 COMPARING TONIGHTS MODELS RUN TO LAST NIGHTS THE LONG WAVE RIDGE OVER THE WEST COAST OF THE UNITED STATES WILL STILL MOVE EAST AND BE LOCATED OVER THE ROCKIES BY FRIDAY. HOWEVER... UNLIKE LAST NIGHTS RUN... WHERE THE RIDGE LOOKED LIKE IT WOULD FLATTEN... IT NOW SEEMS IT WILL MAINTAIN ITS AMPLITUDE. THIS WILL PRODUCE A PREDOMINATELY NORTHWESTERN UPPER LEVEL FLOW OVER THE TRI-STATE AREA DURING THE EXTENDED. YESTERDAYS QUESTION WAS WHEN WILL THE NEXT FRONT PASS OVER THE AREA. TONIGHTS RUN OF THE GFS... NAVGEM AND ECMWF ARE IN BETTER AGREEMENT ON THIS FRONT COMPARED TO LAST NIGHTS RUN. THEY ALL HAVE THE FRONT PASSING OVER THE AREA ON THE 19TH BETWEEN 00Z AND 06Z. THEY ALSO SHOW THIS SYSTEM TO BE A DRY ONE AND WILL HAVE LITTLE TO NO EFFECT ON THE TEMPERATURES. IT DOES SHOW A SHIFT IN THE WINDS FOLLOWED BY LIGHT WINDS AS HIGH PRESSURE BUILDS IN BEHIND IT FOR THE REST OF THE EXTENDED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 440 AM MST SAT NOV 15 2014 MODELS ARE HAVING A HARD TIME RESOLVING ONGOING CONDITIONS. THEY ARE TENDING TO OVERDUE LOW LEVEL CLOUD COVER AND PRECIPITATION. WILL BE GOING WITH PERSISTENCE/CURRENT CONDITIONS AND THE BEST MESOSCALE GUIDANCE FOR THE BEGINNING OF THIS FORECAST. FIRST SHORTWAVE AND ASSOCIATED SNOWFALL HAS MOVED TO THE EAST OF BOTH TAF SITES. SO WILL HAVE VFR CONDITIONS AND NO SNOWFALL AT BOTH SITES UNTIL THIS AFTERNOON WHEN NEXT SHORTWAVE TROUGH MOVES IN. MVFR CEILINGS WILL BE POSSIBLE AT BOTH SITES THIS AFTERNOON INTO EARLY THIS EVENING. AFTER THAT VFR CONDITIONS WILL RETURN TO BOTH SITES. A COLD FRONT WILL MOVE THROUGH LATE THIS MORNING INTO EARLY THIS AFTERNOON AND WILL PRODUCE SUSTAINED WINDS OF 15 TO 20 KNOTS WITH GUSTS GETTING CLOSE TO 30 KNOTS. GUSTS WILL END EARLY THIS EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...BDW/BULLER AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
523 AM CST Sat Nov 15 2014 ...AVIATION UPDATE... .SHORT TERM...(Today and Tonight) Issued at 223 AM CST SAT NOV 15 2014 09Z Water vapor and profiler data show the lead shortwave beginning to come out of the Rockies and into western KS. Regional radars show a band of precip preceding the wave now moving into central KS. So the forecast appears to be on track, kind of. Models continue to show a progressive wave moving across the area today and the best forcing and lift is expected to overspread north central KS during the next 3 to 6 hours. By noon or shortly after, the forcing diminishes and models show the vertical motion shifting out of the area. There still does not appear to be much of a surface reflection with the short wave that could enhance mesoscale forcing either. There atmosphere does appear to be weakly unstable with some conditional symmetric instability and even hints of upright instability which could allow for a brief intensification to the snowfall. There have been some lightning strikes over the central Rockies with the wave. In general everything points to lower snow amounts today due to no sustained forcing mechanism to maintain precipitation. And given the track of the wave, which fits well with the latest guidance, north central KS is more likely to see 1 to 3 inches while east central KS might be lucky to pick up an inch. Will not make any changes to the advisory at this time. The biggest impact could be a brief period of heavy snow in the convective elements that restricts visibilities and quickly brings an inch or so of snow. Have bumped up highs today to around the freezing mark. While it is not real strong, there is persistent low level warm air advection with the southeast winds of 5 to 10 mph. If snowfall ends early in the day and the clouds thin, highs could be a degree or two warmer. Am not real concerned about mixed precip today as forecast soundings maintain temps below freezing aloft. Its only at the surface where temps warm above freezing and this is likely to happen once the snowfall exits to the east and north. About the only concern I have for a different precip type other than snow is for the potential of light drizzle this afternoon. Low levels stay saturated with some weak isentropic lift in the cloud. If drizzle (or freezing drizzle depending on temps) were to happen, think it would occur after the area of snow has ended due to a lose of forcing and deep vertical motion. For tonight, there remains some forcing as a more amplified wave swings across NEB driving a cold front through the area. However by this time models have a hard time keeping the column saturated. Have kept some small chances going to account for the wave, but think any snow would not amount to much. The one concern this evening would be possible strengthening northwest winds behind the front. Models suggest speed around 15 MPH are possible behind the front and any snow that was falling could blow around some. Again think this may be a marginal impact and last for a short period of time. Lows tonight should fall into the teens as cold air moves in behind the front. .LONG TERM...(Sunday through Friday) Issued at 223 AM CST SAT NOV 15 2014 Lingering flurries quickly come to an end early Sunday morning as dry air continues to increase aloft with the upper forcing exiting. A piece of energy from the main upper trough progresses through Kansas during the afternoon as subsident air quickly follows and scours cloud deck to the south. A secondary and colder than previous 1040 MB surface high begins to spread into the CWA as highs struggle into the 20s. Temps from this point on become colder through Tuesday as the arctic airmass spreads across much of the country. Coldest night thus far in the season will be on Tuesday morning as all guidance points at record cold lows in the single digits. A rebound in temps commences through the end of the period as the surface high shifts east and warmer air advects northward, boosting highs near 40 degrees Wednesday through Friday. A poignant blocking ridge across the western CONUS will prevail dry northwest flow aloft through Thursday with indication from the GFS/ECMWF on the ridge beginning to break down Friday as an upper trough enters the west coast. && .AVIATION...(For the 12Z TAFs through 12Z Sunday Morning) Issued at 523 AM CST SAT NOV 15 2014 An area of snow continues to move northeast towards the terminals. Based on radar, the snow may impact the airports 1-2 hours sooner the the HRRR or RAP suggest. Have kept a tempo for IFR conditions since the NAM and GFS show potential for upright instability and brief periods of more intense snowfall. Otherwise think there is a short window for accumulating snowfall. Main uncertainty with the forecast are the CIGS. NAM MOS wants to keep a prolonged period of MVFR conditions after the snow is expected to diminish. Based on obs over southwest MO and northeast OK, this seems unlikely. Did bring some MVFR CIGS back in after the FROPA. But this to should not last long as dry air advects in from the northwest. && .TOP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY until 6 PM CST this evening FOR KSZ008>012-020>024-026-034>040-054>056-058-059. && $$ SHORT TERM...Wolters LONG TERM...Bowen AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
405 AM MST SAT NOV 15 2014 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 404 AM MST SAT NOV 15 2014 MAIN FORECAST CONCERN WILL BE WINTER WEATHER EVENT OCCURRING THROUGH TONIGHT. SATELLITE CONTINUING TO SHOW AN AMPLIFIED PATTERN FROM THE EASTERN PACIFIC INTO EASTERN NORTH AMERICA. CURRENTLY NEARLY ZONAL FLOW OVER OUR AREA WITH MULTIPLE SMALL SCALE WAVES EMBEDDED WITHIN THAT FLOW. STRONG...COLD AND RATHER COMPLEX UPPER TROUGH IS MOVING THROUGH THE NORTH CENTRAL OF THE COUNTRY. SATELLITE ALSO SHOWING DRY MID LEVEL AIR MASS IN PLACE AHEAD OF INCOMING NORTHERN TROUGH. ANOTHER STRONG COLD FRONT IS APPROACHING FROM THE NORTH. AT JET LEVEL...MODELS LOOKED LIKE THEY INITIALIZED FINE. AT MID LEVELS...THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF AND CANADIAN. THE SREF WAS DOING THE BEST AT THE SURFACE. ALL THE MODELS WERE OKAY ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...THE DAY STARTS OUT WITH AREA IN SUBSIDENCE FROM DEPARTING JET. AFTER THIS MODELS DISAGREE WHERE THE MAIN JET ENERGY WILL BE THROUGH THE REST OF THE PERIOD. BY 18Z IT LOOKS LIKE A LEFT FRONT QUADRANT WILL BEGIN AFFECTING THE AREA. BY LATE IN THE AFTERNOON INTO THE EVENING...THERE MAY BE A RIGHT REAR QUADRANT ACROSS THE SOUTHEASTERN PORTION OF THE AREA. AFTER THAT THE JET IS WELL SOUTH. CURRENTLY INITIAL SHORTWAVE TROUGH IS MOVING THROUGH AND PRODUCING LIGHT SNOW OVER SOUTHERN AND EASTERN SECTIONS. MODELS HAVE A GOOD HANDLE ON THIS INITIAL SHORTWAVE TROUGH. CURRENT RADAR SHOWS THAT THE MOST INTENSE SNOWFALL IS TO THE SOUTH OF AREA AND MOVING THROUGH RATHER QUICKLY. ALL NIGHT THE HRRR HAS BEEN CATCHING THE CURRENT RADAR TRENDS EXTREMELY WELL AND IT ALSO MATCHES UP WELL WITH THE ABOVE MENTIONED MID AND UPPER LEVEL LIFT. OTHER OUTPUT IS TOO FAR NORTH WITH THE PRECIPITATION SHIELD. SO WILL LEAN HEAVILY ON THE HRRR FOR PRECIPITATION EARLY ON AND THEN TREND MORE TOWARD THE CANADIAN/ECMWF AFTER THAT. SO LITTLE TO NO SNOW FALL WILL END UP FALLING OVER THE WESTERN HALF TO TWO THIRDS THIS MORNING WITH MOST OF THE SNOW OCCURRING IN THE EASTERN SIX COUNTIES THROUGH MID MORNING. UPSTREAM SATELLITE IS SHOWING A CLEARING TREND BEHIND THIS EXITING SHORTWAVE AND A DRY AIR MASS IN ADVANCE OF THE NEXT SHORTWAVE TROUGH. AFTER THE SNOW ENDS THIS MORNING...THE NEXT BATCH OF LIGHT SNOW WILL DEVELOP TO OUR NORTH AND NORTHWEST BY LATE IN THE MORNING TO EARLY AFTERNOON. THIS AREA THEN MOVES ACROSS THE AREA THROUGH THE REST OF THE NIGHT WITH THE MOST SNOWFALL OCCURRING BEFORE MIDNIGHT. IT IS POSSIBLE THAT SOME LOCATIONS MAY NOT SEE ANY SNOW UNTIL LATER THIS AFTERNOON TO EARLY THIS EVENING. MODELS...ESPECIALLY THE GFS...TEND TO BE TOO DEEP WITH THE MOISTURE AND THEREFORE OVERPRODUCES PRECIPITATION. THE DRIER AIR MASS UPSTREAM MAKES SENSE SINCE MOISTURE IN THE WESTERLY FLOW ALOFT IS GETTING WRUNG BY THE HIGHER TERRAIN OVER COLORADO. SO PER THE REASONING GIVEN ABOVE...SNOWFALL AMOUNTS WILL BE MUCH LIGHTER THAN PREVIOUSLY EXPECTED WITH TOTAL AMOUNTS NOW ANTICIPATED TO BE AROUND AN INCH OR LESS. IT IS ALSO POSSIBLE THAT WHEN THE COLD FRONT MOVES THROUGH LATER TODAY...THAT LITTLE IF ANY SNOW WILL BE ON THE GROUND. ALSO CONSIDERING WHAT LITTLE SNOW HAS ALREADY FALLEN AND THAT THERE WILL BE A SIGNIFICANT LULL BEFORE THE NEXT SNOWFALL STARTS...HAVE DECIDED TO CANCEL THE WINTER WEATHER ADVISORY. IF SNOWFALL ENDS UP BEING WORSE THAN CURRENTLY EXPECTED...THEN A MORE SHORT TERM ADVISORY CAN BE ISSUED TO HANDLE THAT SINCE NOTHING IS GOING ON AT THIS TIME. NOW FOR TEMPERATURS. JUST LIKE LAST NIGHT...MODELS ARE TOO COOL WITH THE CURRENT TEMPERATURES DUE TO CLOUD COVER AND CONTINUED WARM AIR ADVECTION. FRONT IS ALSO EXPECTED TO ARRIVE LATER AND WILL NOT MOVE THROUGH THE EASTERN PORTION OF THE AREA UNTIL THIS AFTERNOON. THERE ALSO MAY BE ENOUGH BREAKS IN THE CLOUD COVER TO ALLOW SOME SUNSHINE TO OCCUR. A LOT OF THE OUTPUT IS SAYING WARMER AND TRENDED IN THAT DIRECTION. SUNDAY/SUNDAY NIGHT...DRY CONDITIONS EXPECTED THROUGH THE PERIOD. SHOULD SEE A DECENT AMOUNT OF SUN WITH WINDS BEING MOSTLY FROM A DOWNSLOPE DIRECTION. MODELS ARE SHOW TEMPERATURES WARMER THAN YESTERDAY. MODELS HAVE HAD A RECENT COOL BIAS AS WELL. SO WENT NEAR THE WARMER GUIDANCE. MONDAY/MONDAY NIGHT...STRONG UPPER SYSTEM DIGS INTO THE NORTH CENTRAL PORTION OF THE COUNTRY JUST BEFORE AND DURING THIS PERIOD. THIS PUSHES ANOTHER COLD FRONT THROUGH THE AREA AND SHOULD MAKE FOR COOLER TEMPERATURES COMPARED TO SUNDAY MAXES. HOWEVER...THERE IS A BIG DIFFERENCE IN THE AMOUNT OF COOLING INDICATED BY THE MODELS. DID NOT GO WITH THE COLDEST GUIDANCE BUT TRENDED IN THE COLDER DIRECTION. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 404 AM MST SAT NOV 15 2014 COMPARING TONIGHTS MODELS RUN TO LAST NIGHTS THE LONG WAVE RIDGE OVER THE WEST COAST OF THE UNITED STATES WILL STILL MOVE EAST AND BE LOCATED OVER THE ROCKIES BY FRIDAY. HOWEVER... UNLIKE LAST NIGHTS RUN... WHERE THE RIDGE LOOKED LIKE IT WOULD FLATTEN... IT NOW SEEMS IT WILL MAINTAIN ITS AMPLITUDE. THIS WILL PRODUCE A PERDOMINATELY NORTHWESTERN UPPER LEVEL FLOW OVER THE TRI-STATE AREA DURING THE EXTENDED. YESTERDAYS QUESTION WAS WHEN WILL THE NEXT FRONT PASS OVER THE AREA. TONIGHTS RUN OF THE GFS... NAVGEM AND ECMWF ARE IN BETTER AGREEMENT ON THIS FRONT COMPARED TO LAST NIGHTS RUN. THEY ALL HAVE THE FRONT PASSING OVER THE AREA ON THE 19TH BWTWEEN 00Z AND 06Z. THEY ALSO SHOW THIS SYSTEM TO BE A DRY ONE AND WILL HAVE LITTLE TO NO EFFECT ON THE TEMPERATURES. IT DOES SHOW A SHIFT IN THE WINDS FOLLOWED BY LIGHT WINDS AS HIGH PRESSURE BUILDS IN BEHIND IT FOR THE REST OF THE EXTENDED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1025 PM MST FRI NOV 14 2014 MONITOR FOR POTENTIAL WINTER PRECIP AT BOTH KGLD AND KMCK TERMINALS DURING THE TAF PERIOD. HIGHEST CONFIDENCE IN LOWER VIS/CIGS IS 09Z-15Z PERIOD...WHEN MVFR...POSSIBLY IFR WILL OCCUR AS LIGHT SNOW DEVELOPS. COULD SEE A BRIEF PERIOD OF FREEZING DRIZZLE AROUND 12-15Z...HOWEVER CONFIDENCE IS TOO LOW IN COVERAGE/TIMING TO ADD MENTION. THERE SHOULD BE IMPROVEMENT IN CONDITIONS BY MIDDAY...WITH ANOTHER ROUND OF SNOW BY LATE SATURDAY AFTERNOON. THERE COULD BE BRIEF REDUCTIONS IN VIS/CIGS WITH THIS SECOND BATCH OF SNOW...HOWEVER THERE ARE STILL TIMING AND COVERAGE VARIATIONS BETWEEN MODELS WITH THIS SECOND ROUND OF SNOW...SO I KEPT VFR CONDITIONS IN THE AFTERNOON/EVENING SATURDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...BDW/BULLER AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
635 AM EST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 416 AM EST SAT NOV 15 2014 A QUIET START TO THE SHORT TERM FORECAST THIS MORNING...AS THE AREA IS ON THE NORTHEAST EDGE OF A HIGH CENTERED FROM THE MID/UPPER MISSISSIPPI VALLEY TO THE OHIO RIVER VALLEY. THIS HAS LED TO A CLEAR AND COLD NIGHT ACROSS AT LEAST HALF OF THE CWA. WHERE WINDS HAVE DECOUPLED (GENERALLY ACROSS THE INTERIOR WEST AND NEAR THE WISCONSIN BORDER)...TEMPERATURES HAVE FALLEN INTO THE SINGLE DIGITS BELOW ZERO. MEANWHILE...OVER THE CENTRAL AND EAST WHERE THE WINDS HAVE BEEN STAYING UP...TEMPERATURES HAVE BEEN IN THE UPPER SINGLE DIGITS ABOVE ZERO TO MID TEENS. OVER LAKE SUPERIOR AND THE KEWEENAW...COLD AIR CONTINUING TO FLOW OVER THE RELATIVELY WARM WATERS OF LAKE SUPERIOR WAS PRODUCING MAINLY LAKE EFFECT CLOUDS THIS PAST EVENING AND INTO THE EARLY OVERNIGHT HOURS. BUT STARTED SEEING WEAK LAKE EFFECT BANDS OVER EASTERN LAKE SUPERIOR ON THE CANADIAN RADAR AT MONTREAL RIVER SHORTLY AFTER MIDNIGHT. INVERSION IS RIGHT AT 875-850MB ON 00Z KGRB/KINL SOUNDINGS AND THE LIMITED MOISTURE ON THE NORTH EDGE OF THE HIGH HAVE BEEN THE MAIN LIMITING FACTORS TO LAKE EFFECT SNOW EARLY THIS MORNING. KMQT VWP HAS BEEN SHOWING THE WINDS A LITTLE MORE OUT OF THE WEST-NORTHWEST AND CONTRIBUTING TO THE LAKE EFFECT CLOUDS NOSING SOUTHEAST INTO BARAGA...SOUTHERN HOUGHTON...AND EVEN FAR NORTHERN IRON COUNTY EARLY THIS MORNING. BUT AS WE HEAD INTO THE MORNING HOURS...MODELS SHOWING THE WINDS GOING BACK TO A MORE WESTERLY AND POTENTIALLY WEST-SOUTHWESTERLY DIRECTION AND CONFINING THE LAKE EFFECT CLOUDS AND SNOW POTENTIAL TO THE KEWEENAW AND OFF THE SHORELINE FROM GRAND MARAIS EASTWARD. THIS WILL ALSO BE AIDED BY THE LAND BREEZE THAT HAS DEVELOPED ALONG THE EASTERN U.P. SHORELINE AND WILL AID IN KEEPING THE BANDS OFFSHORE THERE. THE COVERAGE OF THE SHOWERS IS A LITTLE BIT OF A CONCERN DUE TO THE LIMITED MOISTURE...BUT WOULD EXPECT SOME UPTICK IN THE SNOW SHOWERS AS 875MB TEMPERATURES FALL FROM -11C ON THE RAP ANALYSIS TO -13/-14C BY THIS AFTERNOON. THUS...WILL CONTINUE TO SHOW POPS RAMPING UP TO HIGH CHANCES OVER THE KEWEENAW. WITH MUCH OF THE LAKE EFFECT CLOUD BELOW THE DGZ...WILL KEEP SNOW RATIOS ON THE LOW END FOR LAKE EFFECT AND ONLY HAVE ACCUMULATIONS AT A DUSTING TO AN INCH IN THAT AREA. OVER THE REST OF THE AREA...EXPECT A SUNNY START TO THE DAY WHICH WILL ALLOW TEMPERATURES TO RISE TO THE LOW-MID 20S THIS AFTERNOON. EXPECT MORE OF A FILTERED SUNSHINE IN THE AFTERNOON AS HIGH CLOUDS MOVE IN AHEAD OF THE WAVE BRUSHING THE AREA LATE TONIGHT. HEADING INTO TONIGHT...FOCUS TURNS TO THE SHORTWAVE CURRENTLY MOVING THROUGH WYOMING. THIS WAVE WILL QUICKLY SHIFT EAST THROUGH NEBRASKA AND SOUTH DAKOTA TODAY AND THEN LIFT NORTHEAST ACROSS NORTHERN LAKE MICHIGAN LATE TONIGHT AND SUNDAY MORNING. EXPECT THE HIGH CLOUDS TO THICKEN THIS EVENING AND MID CLOUDS TO MOVE IN DURING THE LATE EVENING AND OVERNIGHT. ANOTHER SHORTWAVE (CURRENTLY IN COLORADO) WILL LIFT NORTHEAST OUT AHEAD OF THE MAIN WAVE AND COULD PRODUCE A FEW SHOWERS AROUND MIDNIGHT. THE BETTER/MAIN FORCING (GENERALLY ABOVE 700MB) COMES FROM THE SECOND SHORTWAVE AND LOOKS TO STAY SOUTHEAST OF THE AREA...BUT DO EXPECT MENOMINEE COUNTY AND AREAS ALONG THE LAKE MICHIGAN SHORELINE TO SEE THE BEST OPPORTUNITY FOR ACCUMULATING SNOW. CURRENT FORECAST HAS SNOWFALL AMOUNTS UP TO AN INCH OVER SOUTHERN MENOMINEE COUNTY AND TAPERING OFF TO A HALF INCH OR LESS SOUTH OF A LINE FROM IRON MOUNTAIN TO MANISTIQUE. SINCE THE NORTHERN EDGE OF THE FORCING WILL BE JUST BRUSHING THE AREA...DO EXPECT A SHARP CUTOFF TO THE PRECIPITATION TO THE NORTHWEST AND KEEP THE SNOW CHANCES TO THE SOUTHEAST OF A LINE FROM MARQUETTE TO WATERSMEET. AS FOR THE LAKE EFFECT OVER THE KEWEENAW...THIS WAVE WILL BACK THE LOW LEVEL WINDS FARTHER TO THE SOUTHWEST AND FOCUS ANY LINGERING LAKE EFFECT TO THE FAR NORTHERN PORTIONS OF THE KEWEENAW PENINSULA. ACCUMULATIONS WILL REMAIN LIGHT AND BELOW 2 INCHES. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 409 AM EST SAT NOV 15 2014 A HI AMPLITUDE PATTERN FEATURING A TROF OVER CENTRAL AND ERN NAMERICA DOWNSTREAM OF A RDG ALONG THE W COAST WL DOMINATE THE WX PATTERN THIS COMING WEEK...LEADING TO PERSISTENT BLO TO WELL BLO NORMAL TEMPS THRU THE WEEK. THE MOST SGNFT WX CONCERN WL BE THE IMPACT OF A POTENT SHRTWV THAT IS FCST TO DIG SEWD THRU THE UPR LKS EARLY IN THE WEEK AND AMPLIFY THE TROF. THIS DISTURBANCE WL ALMOST CERTAINLY BRING ANOTHER ROUND OF MODERATE TO HEAVY LES AND SOME BLSN MAINLY TO THE NW WIND SN BELTS NEAR LK SUP ON MON INTO TUE. YET ANOTHER DISTURBANCE DIGGING THRU THE UPR TROF MAY BRING MORE SGNFT LES ON WED INTO THU. SUN...ONGOING LIGHT SN OVER THE SE CWA WL END BY EARLY IN THE AFTN AS SHRTWV OVER ERN WI AT 12Z AND ACCOMPANYING DYNAMIC FORCING/ DEEPER MSTR EXIT TO THE E THRU LOWER MI AND INTO FAR SE ONTARIO IN THE AFTN. AXIS OF DRIER AIR/DEEP LYR QVECTOR DVGC BTWN THIS DEPARTING SHRTWV AND ANOTHER MORE POTENT SHRTWV DIGGING SE THRU SCENTRAL CANADA WL THEN BRING A PERIOD OF DRY WX TO THE CWA. ALTHOUGH H85 TEMPS ARE FCST TO BE AS LO AS -12 TO -13C...THE FCST 230 DEGREE LLVL FLOW IN ADVANCE OF THE APRCHG SHRTWV WL HOLD ANY LES MAINLY TO THE NW OF THE KEWEENAW PENINSULA AND E OF LUCE/SCHOOLCRAFT COUNTIES. ALTHOUGH DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THE INCOMING SHRTWV ARE FCST TO INVADE THE WRN CWA LATER IN THE DAY... THE ABSENCE OF ANY SGNFT LLVL MSTR INFLOW WL MAINTAIN DRY WX THRU 00Z MON UNDER INCRSG HI/MID CLDS. SUN NIGHT...INCOMING SHRTWV/SFC LO ARE FCST TO DRIFT OVER NRN LK SUP BY 12Z MON AND CAUSE 12HR H5 HGT FALLS UP TO 120M ACROSS THE UPR LKS. AXIS OF DPVA/DEEP LYR QVECTOR CNVGC WITHIN THE COMMA TAIL OF THIS FEATURE ARE FCST TO SWING ACROSS UPR MI. HOWEVER...POTENTIAL FOR WIDESPREAD SN IN ADVANCE OF THE SHRTWV WL BE LIMITED BY THE ABSENCE OF LLVL MOISTENING/PWAT UNDER 0.25 INCH/H7 SPECIFIC HUMIDITY NO MORE THAN ABOUT 1 G/KG. STILL LOOKS LIKE THE LLVL FLOW WL NOT BACK SUFFICIENTLY TO ALLOW ANY LK ENHANCED OFF LK MI TO IMPACT LUCE OR SCHOOLCRAFT COUNTIES. THE BEST CHC FOR MORE WIDESPREAD/HEAVIER SNOW WL BE OVER THE W MAINLY LATE FOLLOWING COLD FROPA AND WIND SHIFT TO AN UPSLOPE NW DIRECTION. ARRIVAL OF H85 TEMPS AROUND -15C WITH SHARP CYC FLOW/LINGERING DEEP MSTR UNDER THE FALLING HGTS WILL WARRANT KEEPING LIKELY TO CATEGORICAL POPS OVER THE W. WL GO NO HIER THAN CHC POPS ELSEWHERE...WITH THE LOWEST SCHC POPS OVER THE SCENTRAL. MON/MON NGT...AS THE UPR TROF DEEPENS INTO THE GREAT LKS AND A CLOSED H5 LO FORMS...UPR MI IS FCST TO BE UNDER SHARP...CYC W VEERING NW FLOW ON MON AND NNW-NW FLOW ON MON NGT. FCST SDNGS SHOW DEEP MOISTURE/INSTABILITY AS H5 TEMPS DIP TOWARD -40C. GIVEN H85 TEMPS FALLING TO -16C TO -18C AND THE DEEP INSTABILITY/MOISTURE WITH THE CYC LLVL FLOW...CATEGORICAL POPS ARE WARRANTED IN THE FAVORED SN BELTS. GUSTY WINDS UNDER THE SHARP PRES GRADIENT/DESTABILIZATION WL CAUSE BLSN IN ADDITIONAL TO THE HEAVIER LES. FAVORABLE OMEGA PROFILE WITHIN THE DGZ SITUATED BTWN ABOUT 1-5K FT AGL WL ALSO ENHANCE SN/WATER RATIOS DESPITE THE IMPACT OF THE STRONG WINDS TO FRAGMENT THE SN FLAKES. RIGHT NOW... THE FAR W IN ONTONAGON/GOGEBIC COUNTIES LOOKS TO PICK UP THE HEAVIEST SN ON MON NGT...WITH ADDITIONAL HEAVY LES IMPACTING AREAS E OF MARQUETTE LATER ON MON THRU MON NGT. LATER SHIFTS NO DOUBT WL NEED TO HOIST LES HEADLINES. THE STRONG NW WINDS MAY ALSO CAUSE HI ENOUGH WAVES ON LK SUPERIOR TO BRING SOME MINOR BEACH EROSION/FLOODING IN AREAS MOST EXPOSED TO THE HIER WINDS/WAVES BEGINNING ON LATE MON. FOR NOW...WL CONTINUE TO MENTION THE SGFNT LES POTENTIAL/BLSN AND HI WAVES IN THE HWO PRODUCT AND EHWO GRAPHICS. TUE/TUE NGT...AS THE CLOSED LO SHIFTS INTO QUEBEC AND 12HR H5 HGT RISES APRCH 100M ON TUE IN THE LARGER SCALE DNVA AHEAD OF TRAILING H5 RDG AXIS...MID LVL SUBSIDENCE/DRYING/TREND TOWARD NEUTRAL OR MORE ACYC LLVL FLOW WL TEND TO WEAKEN THE LES W TO E. STEADILY BACKING WINDS OVER THE W THRU THE DAY AND MAINLY DURING TUE AFTN OVER THE E WL TEND TO LIMIT THE RESIDENCE TIME OF THE HEAVIER SN BANDS AND SHIFT THE LES TO PRIMARILY OVER THE KEWEENAW AND TO THE E OF MUNISING BY LATE IN THE DAY. DESPITE THIS DIMINISHING TREND...SN TOTALS ON MON THRU TUE WL LIKELY APRCH OR EXCEED A FOOT IN THE FAVORED SN BELTS OVER THE W CENTERED IN ONTONAGON COUNTY AND E OF MUNISING. AS THE FLOW CONTINUES TO BACK TOWARD THE SW ON TUE NGT IN ADVANCE OF NEXT CLIPPER SHRTWV DIGGING SEWD TOWARD MN...THE MAIN AREA OF LES SHOULD SHIFT INTO LK SUP. BUT MORE WIDESPREAD SN MAY ARRIVE LATE AT NGT AT LEAST OVER THE W WITH THE ONSET OF MORE VIGOROUS DYNAMIC FORCING/HGT FALLS IN THE DPVA AHEAD OF THE NEXT SHRTWV. WED THRU FRI...PASSAGE OF POTENT SHRTWV/VIGOROUS DYNAMIC FORCING WL BRING THE THREAT OF A MORE WIDESPREAD SN AGAIN ON WED DESPITE RATHER LIMITED ABSOLUTE MSTR /FCST PWAT UNDER 0.25 INCH/. MORE LES WL BE THE RULE ON THU INTO FRI MAINLY IN THE NW WIND SN BELTS AS ANOTHER COLD SHOT WITH H85 TEMPS AS LO AS -16 TO -18C POURS INTO THE UPR LKS BEHIND THE DEPARTING SHRTWV. LONGER RANGE MODELS CONTINUE TO POINT TOWARD SOME MODERATION IN THE COLD NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 635 AM EST SAT NOV 15 2014 WESTERLY WINDS OFF LAKE SUPERIOR WILL CONTINUE TO LEAD TO LAKE EFFECT CLOUDS (HIGH END MVFR) AND SOME SNOW SHOWERS AT KCMX THROUGH MUCH OF THE PERIOD. CONFIDENCE IS LOW ON THE ORGANIZED NATURE OF THE LAKE EFFECT SNOW...DUE TO THE EXISTING DRY AIR...SO WILL KEEP VISIBILITIES AT VFR VALUES. FOR KIWD/KSAW...EXPECT VFR CONDITIONS DUE TO UNFAVORABLE WIND DIRECTIONS FOR LAKE EFFECT. LEFT OVER LAKE EFFECT CLOUDS FROM THE KEWEENAW HAVE BEEN TRYING TO PUSH INTO NORTHERN MARQUETTE COUNTY THIS MORNING. WITH WINDS OUT OF THE WEST-NORTHWEST...THEY WILL TRY TO APPROACH KSAW BUT FEEL THEY WILL STAY MAINLY TO THE NORTH OF THE SITE. AN APPROACHING UPPER LEVEL DISTURBANCE WILL LEAD TO INCREASING HIGH/MID CLOUDS THIS AFTERNOON AND TONIGHT. KSAW WILL BE THE CLOSEST FOR SOME SNOW SHOWERS AND WILL MENTION VCSH LATE TONIGHT AS THEY APPROACH. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EST SAT NOV 15 2014 UNDER A SHARP PRES GRADIENT BETWEEN HI PRES IN THE OH RIVER VALLEY AND LO PRES OVER HUDSON BAY...PLAN ON W WINDS UP TO 20-30KTS INTO SUN. THE WINDS WL THEN BACK TOWARD THE SW AND DIMINISH TO UP TO 25KTS IN ADVANCE OF ANOTHER STRONG DISTURBANCE MOVING THRU SCENTRAL CANADA AND INTO NORTHERN LAKE SUPERIOR ON MON MORNING. FOLLOWING THE PASSAGE OF THIS LO TO THE E...THE PRES GRADIENT WILL TIGHTEN AND THE INSTABILITY WILL INCREASE AS ANOTHER SURGE OF COLD AIR FLOWS OVER THE RELATIVELY WARM LAKE WATERS. THE RESULT WILL BE A PERIOD OF NW GALES ON MON INTO TUE. SINCE THIS AIRMASS WILL BE SUFFICIENTLY COLD...THERE WILL LIKELY BE SOME FREEZING SPRAY IN SOME AREAS. THE BEST CHANCE FOR THE GALES WILL BE OVER CENTRAL LAKE SUPERIOR. AS THE LO PRES MOVES AWAY ON TUE AND HI PRES SHIFTS E...EXPECT THE WINDS TO BACK TO THE W AND DIMINISH TO 25 TO 30KTS. THE PASSAGE OF ANOTHER STRONG DISTURBANCE ON WED MAY LEAD TO ANOTHER NW GALE EVENT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...KC AVIATION...SRF MARINE...KC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
839 AM CST SAT NOV 15 2014 .UPDATE... ISSUED AT 839 AM CST SAT NOV 15 2014 UPDATED THE FORECAST TO CANCEL THE WIND CHILL ADVISORY FOR WEST CENTRAL AND NORTHWESTERN NORTH DAKOTA THIS MORNING. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A STRATUS DECK BEGINNING TO DRIFT SOUTH ACROSS NORTHWESTERN NORTH DAKOTA. ISOLATED FLURRIES HAVE BEEN REPORTED UNDER THIS STATUS DECK. AS A RESULT...ADDED ISOLATED FLURRIES TO THE FORECAST NORTHWEST THIS MORNING. THE STRATUS SHOULD BEGIN TO BREAK UP SOMEWHAT BY THIS AFTERNOON. THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 653 AM CST SAT NOV 15 2014 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC. WILL LEAVE THE WIND CHILL ADVISORY IN PLACE AS BORDERLINE ADVISORY CRITERIA VALUES NEAR -25 WILL CONTINUE EARLY THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM CST SAT NOV 15 2014 MAIN HIGHLIGHT THIS MORNING IS A WIND CHILL ADVISORY FOR PORTIONS OF THE FAR WEST. COLDER AIR COMING IN FROM THE WEST AND BRISK WINDS WILL DOMINATE THROUGH MID MORNING. A POTENT SHORTWAVE AND ASSOCIATED COLD FRONT SHIFTING SOUTH FROM CENTRAL CANADA WILL BEGIN TO IMPACT WESTERN/NORTHERN NORTH DAKOTA LATE SATURDAY NIGHT THEN SPREAD SOUTH SUNDAY MORNING. THE LATEST WATER VAPOR IMAGERY SHOWS AN ELONGATED UPPER TROUGH FROM HUDSON BAY SOUTHWEST INTO MONTANA. AHEAD OF THE TROUGH...A SHORTWAVE WAS SEEN ALONG THE WYOMING/MONTANA BORDER MOVING EAST TO SOUTHEAST WITH TIME...AS THE SURFACE LOW REMAINS FARTHER SOUTH. LIGHT SNOW ASSOCIATED WITH THIS SYSTEM EXTENDED ACROSS CENTRAL AND SOUTHERN SOUTH DAKOTA AND IS MOVING EAST. FARTHER UPSTREAM...AN AREA OF STRATUS OVER SOUTHERN SASKATCHEWAN PER LATEST FOG/STRATUS LOOP CONTINUES A SOUTHEAST MOVEMENT. THE HRRR AND RAP13 SHIFT THIS INTO NORTHWEST AND NORTH CENTRAL NORTH DAKOTA BETWEEN 12Z-21Z TODAY. CONCUR WITH THIS AND ADJUSTED SKY GRIDS ACCORDINGLY. ELSEWHERE ISOLATED FLURRIES WITH POCKETS OF STRATUS CONTINUE EARLY THIS MORNING IN THE FAR SOUTHWEST...ALONG AND SOUTH OF LAKE SAKAKAWEA...AND IN THE SOUTHERN JAMES RIVER VALLEY. ANOTHER VERY COLD DAY AHEAD WITH HIGHS IN THE SINGLE DIGITS ABOVE ZERO IN THE WEST AND SOUTHWEST...TO LOWER/MIDDLE TEENS ELSEWHERE. BRISK NORTHWEST WINDS THIS AFTERNOON 10 TO 25 MPH. FOR TONIGHT...ATTENTION TURNS TO A STRONG SHORTWAVE TROUGH AND ASSOCIATED SHARP COLD FRONT HEADING DUE SOUTH FROM THE NORTHWEST TERRITORIES. THE COLD FRONT WILL PASS THROUGH NORTHWEST AND NORTH CENTRAL AFTER MIDNIGHT WITH INCREASING WINDS TOWARD AND SHORTLY AFTER DAYBREAK ON SUNDAY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 406 AM CST SAT NOV 15 2014 BLOWING SNOW POTENTIAL ON SUNDAY HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES THE TREND OVER THE PAST SEVERAL DAYS OF A REINFORCING COLD FRONT TO PROPAGATE ACROSS WESTERN AND CENTRAL NORTH DAKOTA SUNDAY MORNING IN ASSOCIATION WITH ITS PARENT CLIPPER SYSTEM ACROSS EASTERN MANITOBA INTO WESTERN ONTARIO. STRONG NORTHWEST WINDS INTERACTING WITH THE SNOWFALL FROM LAST WEEKEND PRESENTS A BLOWING SNOW THREAT. THE CHALLENGE IS IF BLIZZARD CRITERIA WILL BE MET ACROSS THE SOUTHWEST WHERE THE MOST SNOW WAS RECEIVED. THE SNOW HAS BEEN ON THE GROUND FOR A WEEK...HOWEVER...IT IS UNCRUSTED AND HAS NOT BEEN SIGNIFICANTLY COMPACTED. THAT SAID....BEING THE FIRST SNOWFALL OF THE SEASON...SOME OF THE SNOW MAY BE ADVERSE TO BEING LOFTED FROM BEING TRAPPED IN THE GRASSES. THUS...WILL FORGO A BLIZZARD WATCH FOR NOW...AND HIGHLIGHT THE THREAT WITH NEAR-BLIZZARD CONDITIONS POSSIBLE IN THE REMAINDER OF THE PRODUCT SUITE AND SPECIAL WEATHER STATEMENT. PROBABILITIES FOR HALF-MILE VISIBILITIES USING THE BAGGALY BLOWING SNOW MODEL TAKING INTO ACCOUNT SNOW AGE AND THE LACK OF SIGNIFICANT FALLING SNOW PRODUCE RESULTS THAT DO NOT FAVOR BLIZZARD CRITERIA BEING MET. FURTHERMORE...THE STRENGTH OF ISALLOBARIC FORCING AND WINDS AT THE TOP OF THE MIXED LAYER DECREASE THROUGH THE DAY...BEING GREATEST PRIOR TO THE PRE-FRONTAL INVERSION BEING BROKEN. CERTAINLY AT LEAST A WINTER WEATHER ADVISORY FOR BLOWING SNOW WILL BE NEEDED FOR THE SOUTHWEST...AND POSSIBLY INTO THE SOUTH CENTRAL. GIVEN FURTHER EVALUATION TODAY.... WOULD NOT BE SURPRISED IF A BLIZZARD WATCH IS ISSUED. THEREAFTER...THE DE-AMPLIFICATION OF THE ANOMALOUS UPPER LEVEL PATTERN IS SLOWER WITH THE 15/00 UTC GUIDANCE CONSENSUS COMPARED TO PREVIOUS RUNS...WITH A RECOVERY FROM ARCTIC AIR LIKELY DELAYED UNTIL LATE NEXT WEEK AT THE EARLIEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 653 AM CST SAT NOV 15 2014 SATELLITE AND SURFACE OBSERVATIONS CONTINUE TO SHOW MVFR CIGS ENTERING WESTERN AND PORTIONS OF SOUTH CENTRAL NORTH DAKOTA THIS MORNING. THIS IS FORECAST TO PERSIST INTO THE EARLY AFTERNOON. CIGS AT KDIK WILL FREQUENTLY VARY BETWEEN MVFR/IFR...WHILE MVFR CIGS WILL CONTINUE TO FILL IN AT KBIS BY 13Z...AND INTO KMOT BY 16Z. KJMS WILL REMAIN VFR TODAY WITH MVFR CIGS SOUTH OF THE TERMINAL. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...KS LONG TERM...AYD AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
654 AM CST SAT NOV 15 2014 .UPDATE... ISSUED AT 653 AM CST SAT NOV 15 2014 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC. WILL LEAVE THE WIND CHILL ADVISORY IN PLACE AS BORDERLINE ADVISORY CRITERIA VALUES NEAR -25 WILL CONTINUE EARLY THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM CST SAT NOV 15 2014 MAIN HIGHLIGHT THIS MORNING IS A WIND CHILL ADVISORY FOR PORTIONS OF THE FAR WEST. COLDER AIR COMING IN FROM THE WEST AND BRISK WINDS WILL DOMINATE THROUGH MID MORNING. A POTENT SHORTWAVE AND ASSOCIATED COLD FRONT SHIFTING SOUTH FROM CENTRAL CANADA WILL BEGIN TO IMPACT WESTERN/NORTHERN NORTH DAKOTA LATE SATURDAY NIGHT THEN SPREAD SOUTH SUNDAY MORNING. THE LATEST WATER VAPOR IMAGERY SHOWS AN ELONGATED UPPER TROUGH FROM HUDSON BAY SOUTHWEST INTO MONTANA. AHEAD OF THE TROUGH...A SHORTWAVE WAS SEEN ALONG THE WYOMING/MONTANA BORDER MOVING EAST TO SOUTHEAST WITH TIME...AS THE SURFACE LOW REMAINS FARTHER SOUTH. LIGHT SNOW ASSOCIATED WITH THIS SYSTEM EXTENDED ACROSS CENTRAL AND SOUTHERN SOUTH DAKOTA AND IS MOVING EAST. FARTHER UPSTREAM...AN AREA OF STRATUS OVER SOUTHERN SASKATCHEWAN PER LATEST FOG/STRATUS LOOP CONTINUES A SOUTHEAST MOVEMENT. THE HRRR AND RAP13 SHIFT THIS INTO NORTHWEST AND NORTH CENTRAL NORTH DAKOTA BETWEEN 12Z-21Z TODAY. CONCUR WITH THIS AND ADJUSTED SKY GRIDS ACCORDINGLY. ELSEWHERE ISOLATED FLURRIES WITH POCKETS OF STRATUS CONTINUE EARLY THIS MORNING IN THE FAR SOUTHWEST...ALONG AND SOUTH OF LAKE SAKAKAWEA...AND IN THE SOUTHERN JAMES RIVER VALLEY. ANOTHER VERY COLD DAY AHEAD WITH HIGHS IN THE SINGLE DIGITS ABOVE ZERO IN THE WEST AND SOUTHWEST...TO LOWER/MIDDLE TEENS ELSEWHERE. BRISK NORTHWEST WINDS THIS AFTERNOON 10 TO 25 MPH. FOR TONIGHT...ATTENTION TURNS TO A STRONG SHORTWAVE TROUGH AND ASSOCIATED SHARP COLD FRONT HEADING DUE SOUTH FROM THE NORTHWEST TERRITORIES. THE COLD FRONT WILL PASS THROUGH NORTHWEST AND NORTH CENTRAL AFTER MIDNIGHT WITH INCREASING WINDS TOWARD AND SHORTLY AFTER DAYBREAK ON SUNDAY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 406 AM CST SAT NOV 15 2014 BLOWING SNOW POTENTIAL ON SUNDAY HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES THE TREND OVER THE PAST SEVERAL DAYS OF A REINFORCING COLD FRONT TO PROPAGATE ACROSS WESTERN AND CENTRAL NORTH DAKOTA SUNDAY MORNING IN ASSOCIATION WITH ITS PARENT CLIPPER SYSTEM ACROSS EASTERN MANITOBA INTO WESTERN ONTARIO. STRONG NORTHWEST WINDS INTERACTING WITH THE SNOWFALL FROM LAST WEEKEND PRESENTS A BLOWING SNOW THREAT. THE CHALLENGE IS IF BLIZZARD CRITERIA WILL BE MET ACROSS THE SOUTHWEST WHERE THE MOST SNOW WAS RECEIVED. THE SNOW HAS BEEN ON THE GROUND FOR A WEEK...HOWEVER...IT IS UNCRUSTED AND HAS NOT BEEN SIGNIFICANTLY COMPACTED. THAT SAID....BEING THE FIRST SNOWFALL OF THE SEASON...SOME OF THE SNOW MAY BE ADVERSE TO BEING LOFTED FROM BEING TRAPPED IN THE GRASSES. THUS...WILL FORGO A BLIZZARD WATCH FOR NOW...AND HIGHLIGHT THE THREAT WITH NEAR-BLIZZARD CONDITIONS POSSIBLE IN THE REMAINDER OF THE PRODUCT SUITE AND SPECIAL WEATHER STATEMENT. PROBABILITIES FOR HALF-MILE VISIBILITIES USING THE BAGGALY BLOWING SNOW MODEL TAKING INTO ACCOUNT SNOW AGE AND THE LACK OF SIGNIFICANT FALLING SNOW PRODUCE RESULTS THAT DO NOT FAVOR BLIZZARD CRITERIA BEING MET. FURTHERMORE...THE STRENGTH OF ISALLOBARIC FORCING AND WINDS AT THE TOP OF THE MIXED LAYER DECREASE THROUGH THE DAY...BEING GREATEST PRIOR TO THE PRE-FRONTAL INVERSION BEING BROKEN. CERTAINLY AT LEAST A WINTER WEATHER ADVISORY FOR BLOWING SNOW WILL BE NEEDED FOR THE SOUTHWEST...AND POSSIBLY INTO THE SOUTH CENTRAL. GIVEN FURTHER EVALUATION TODAY.... WOULD NOT BE SURPRISED IF A BLIZZARD WATCH IS ISSUED. THEREAFTER...THE DE-AMPLIFICATION OF THE ANOMALOUS UPPER LEVEL PATTERN IS SLOWER WITH THE 15/00 UTC GUIDANCE CONSENSUS COMPARED TO PREVIOUS RUNS...WITH A RECOVERY FROM ARCTIC AIR LIKELY DELAYED UNTIL LATE NEXT WEEK AT THE EARLIEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 653 AM CST SAT NOV 15 2014 SATELLITE AND SURFACE OBSERVATIONS CONTINUE TO SHOW MVFR CIGS ENTERING WESTERN AND PORTIONS OF SOUTH CENTRAL NORTH DAKOTA THIS MORNING. THIS IS FORECAST TO PERSIST INTO THE EARLY AFTERNOON. CIGS AT KDIK WILL FREQUENTLY VARY BETWEEN MVFR/IFR...WHILE MVFR CIGS WILL CONTINUE TO FILL IN AT KBIS BY 13Z...AND INTO KMOT BY 16Z. KJMS WILL REMAIN VFR TODAY WITH MVFR CIGS SOUTH OF THE TERMINAL. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR NDZ001-009-017-018-031>033. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...AYD AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
406 AM CST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM CST SAT NOV 15 2014 MAIN HIGHLIGHT THIS MORNING IS A WIND CHILL ADVISORY FOR PORTIONS OF THE FAR WEST. COLDER AIR COMING IN FROM THE WEST AND BRISK WINDS WILL DOMINATE THROUGH MID MORNING. A POTENT SHORTWAVE AND ASSOCIATED COLD FRONT SHIFTING SOUTH FROM CENTRAL CANADA WILL BEGIN TO IMPACT WESTERN/NORTHERN NORTH DAKOTA LATE SATURDAY NIGHT THEN SPREAD SOUTH SUNDAY MORNING. THE LATEST WATER VAPOR IMAGERY SHOWS AN ELONGATED UPPER TROUGH FROM HUDSON BAY SOUTHWEST INTO MONTANA. AHEAD OF THE TROUGH...A SHORTWAVE WAS SEEN ALONG THE WYOMING/MONTANA BORDER MOVING EAST TO SOUTHEAST WITH TIME...AS THE SURFACE LOW REMAINS FARTHER SOUTH. LIGHT SNOW ASSOCIATED WITH THIS SYSTEM EXTENDED ACROSS CENTRAL AND SOUTHERN SOUTH DAKOTA AND IS MOVING EAST. FARTHER UPSTREAM...AN AREA OF STRATUS OVER SOUTHERN SASKATCHEWAN PER LATEST FOG/STRATUS LOOP CONTINUES A SOUTHEAST MOVEMENT. THE HRRR AND RAP13 SHIFT THIS INTO NORTHWEST AND NORTH CENTRAL NORTH DAKOTA BETWEEN 12Z-21Z TODAY. CONCUR WITH THIS AND ADJUSTED SKY GRIDS ACCORDINGLY. ELSEWHERE ISOLATED FLURRIES WITH POCKETS OF STRATUS CONTINUE EARLY THIS MORNING IN THE FAR SOUTHWEST...ALONG AND SOUTH OF LAKE SAKAKAWEA...AND IN THE SOUTHERN JAMES RIVER VALLEY. ANOTHER VERY COLD DAY AHEAD WITH HIGHS IN THE SINGLE DIGITS ABOVE ZERO IN THE WEST AND SOUTHWEST...TO LOWER/MIDDLE TEENS ELSEWHERE. BRISK NORTHWEST WINDS THIS AFTERNOON 10 TO 25 MPH. FOR TONIGHT...ATTENTION TURNS TO A STRONG SHORTWAVE TROUGH AND ASSOCIATED SHARP COLD FRONT HEADING DUE SOUTH FROM THE NORTHWEST TERRITORIES. THE COLD FRONT WILL PASS THROUGH NORTHWEST AND NORTH CENTRAL AFTER MIDNIGHT WITH INCREASING WINDS TOWARD AND SHORTLY AFTER DAYBREAK ON SUNDAY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 406 AM CST SAT NOV 15 2014 BLOWING SNOW POTENTIAL ON SUNDAY HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES THE TREND OVER THE PAST SEVERAL DAYS OF A REINFORCING COLD FRONT TO PROPAGATE ACROSS WESTERN AND CENTRAL NORTH DAKOTA SUNDAY MORNING IN ASSOCIATION WITH ITS PARENT CLIPPER SYSTEM ACROSS EASTERN MANITOBA INTO WESTERN ONTARIO. STRONG NORTHWEST WINDS INTERACTING WITH THE SNOWFALL FROM LAST WEEKEND PRESENTS A BLOWING SNOW THREAT. THE CHALLENGE IS IF BLIZZARD CRITERIA WILL BE MET ACROSS THE SOUTHWEST WHERE THE MOST SNOW WAS RECEIVED. THE SNOW HAS BEEN ON THE GROUND FOR A WEEK...HOWEVER...IT IS UNCRUSTED AND HAS NOT BEEN SIGNIFICANTLY COMPACTED. THAT SAID....BEING THE FIRST SNOWFALL OF THE SEASON...SOME OF THE SNOW MAY BE ADVERSE TO BEING LOFTED FROM BEING TRAPPED IN THE GRASSES. THUS...WILL FORGO A BLIZZARD WATCH FOR NOW...AND HIGHLIGHT THE THREAT WITH NEAR-BLIZZARD CONDITIONS POSSIBLE IN THE REMAINDER OF THE PRODUCT SUITE AND SPECIAL WEATHER STATEMENT. PROBABILITIES FOR HALF-MILE VISIBILITIES USING THE BAGGLEY BLOWING SNOW MODEL TAKING INTO ACCOUNT SNOW AGE AND THE LACK OF SIGNIFICANT FALLING SNOW PRODUCE RESULTS THAT DO NOT FAVOR BLIZZARD CRITERIA BEING MET. FURTHERMORE...THE STRENGTH OF ISALLOBARIC FORCING AND WINDS AT THE TOP OF THE MIXED LAYER DECREASE THROUGH THE DAY...BEING GREATEST PRIOR TO THE PRE-FRONTAL INVERSION BEING BROKEN. CERTAINLY AT LEAST A WINTER WEATHER ADVISORY FOR BLOWING SNOW WILL BE NEEDED FOR THE SOUTHWEST...AND POSSIBLY INTO THE SOUTH CENTRAL. GIVEN FURTHER EVALUATION TODAY.... WOULD NOT BE SURPRISED IF A BLIZZARD WATCH IS ISSUED. THEREAFTER...THE DE-AMPLIFICATION OF THE ANOMALOUS UPPER LEVEL PATTERN IS SLOWER WITH THE 15/00 UTC GUIDANCE CONSENSUS COMPARED TO PREVIOUS RUNS...WITH A RECOVERY FROM ARCTIC AIR LIKELY DELAYED UNTIL LATE NEXT WEEK AT THE EARLIEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 406 AM CST SAT NOV 15 2014 AN AREA OF MVFR CIGS OVER SASKATCHEWAN AND NORTHEAST MONTANA CONTINUE TO SHIFT SOUTHEAST TOWARD KISN EARLY THIS MORNING. EXPECT MVFR CIGS INTO KISN BETWEEN 10Z-12Z SATURDAY...AND INTO KMOT BY 15Z SATURDAY. ELSEWHERE...POCKETS OF LOW VFR CIGS WILL CONTINUE OVER KJMS THROUGH THE EARLY MORNING...WITH KDIK DETERIORATING FROM VFR TO MVFR/IFR. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR NDZ001-009-017-018-031>033. && $$ SHORT TERM...KS LONG TERM...AYD AVIATION...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
846 AM EST SAT NOV 15 2014 .SYNOPSIS... HIGH PRESSURE LINGERS TODAY. NEXT SYSTEM WITH DEEPER MOISTURE SUNDAY NIGHT INTO MONDAY. REINFORCING COLD AIR ARRIVES MONDAY NIGHT INTO TUESDAY. COLDEST DAY TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... 845 AM UPDATE...NO MAJOR CHANGES NEEDED. DID HIT RECORD OR NEAR RECORD LOWS FOR MUCH OF THE AREA THIS MORNING. PREVIOUS DISCUSSION BELOW... STRATUS HANGING TOUGH OVER THE N MOUNTAINS ATTM WHICH IS KEEPING TEMPS UP AT EKN COMPARED A HAIR. EXPECT THESE CLOUDS TO DISSIPATE PER HRRR OVER THE NEXT SEVERAL HRS. ELSEWHERE...QUITE COLD WITH TEMPS RUNNING A BIT BLOW FCST CURVE IN THE OUTLYING AREAS. ADJUSTED HOURLY TEMPS AND MINT GRID DOWN A FEW DEGREES...ESPECIALLY AWAY FROM URBAN CENTERS. MID TEENS LOOK LIKE A GOOD BET ACROSS THESE LOCATIONS ACROSS THE LOWLANDS. IF THE CLOUDS OVER THE MOUNTAINS CAN CLEAR IN TIME...THEN SOME HIGH SINGLE NUMBERS ARE POSSIBLE OVER THE HIGH RIDGES. SNOWSHOE CURRENTLY SITTING AT 11F. AS FOR TODAY...THE SUN WILL FINALLY MAKE AN APPEARANCE...ALBEIT WITH A SHORT STAY. SOME CIRRUS WILL STREAK IN DURING THE FIRST HALF OF TODAY...FOLLOWED BY INCREASE IN MID LEVEL CLOUDS ASSOCIATED WAA ALOFT LATE IN THE AFTERNOON AND EARLY EVENING /FROM SW TO NE/. H85 TEMPS WILL MODERATE BY ALMOST 10 DEGREES TODAY. STILL...WITH H925 TEMPS STILL ON THE COOL SIDE...FELT ROLLING WITH COOLER GUIDANCE /A LA LOCAL IN HOUSE MOS/ WAS THE BEST OPTION. AS SUCH...HAVE SOME MID 30S FOR THE LOWLANDS WITH LOWER 30S FOR THE HIGH TERRAIN. BIGGEST IMPROVEMENT IN TEMPS COMPARED TO YESTERDAY WILL BE FELT IN THE HIGHER ELEVATIONS WHERE SNOWSHOE SHOULD MAKE A RUN TOWARD UPPER 20S LATE IN THE DAY VERSUS LOW TEENS OBSERVED YESTERDAY. A MID LEVEL DISTURBANCE WILL RACE THROUGH THE REGION TONIGHT. HOWEVER...WITH LITTLE FANFARE OTHER THAN THE INCREASE IN MIDDLE LEVEL CLOUDS. THE WAA ALOFT CONTINUES THOUGH...SO HAVE HIGHEST RIDGES HOLDING NEAR STEADY IF NOT RISING TOWARD MORNING WITH GENERALLY MID 20S IN THE LOWLANDS. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... A WAVE MOVING ACROSS SATURDAY NIGHT INTO SUNDAY SUFFERS FROM LACK OF LOW LEVEL MOISTURE. SHOULD SEE LOTS OF VIRGA...BUT QUESTIONABLE HOW MUCH MAKES IT TO THE GROUND. WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE CATEGORIES...SLOWING INCREASING AS THE COLUMN TRIES TO SATURATE. MAIN SYSTEM OF INTEREST ARRIVES SUNDAY NIGHT AND CONTINUES INTO MONDAY. SREF/NAM/ECMWF ARE THE WARMEST OF THE MODELS...WITH THE GFS AND CANADIAN ON THE COOLER SIDE. WILL RUN IN BETWEEN THE 2 CAMPS FOR NOW...KEEPING A BAND OF PRECIPITATION IN THE MIDDLE THAT COULD BE EITHER RAIN OR SNOW. THIS BASICALLY KEEPS MOST OF WV AND VA AS RAIN...WITH A TRANSITION ZONE ACROSS NORTHEAST KY/SOUTHEAST OH AND FAR NW WV. CENTRAL OH HAS THE BEST CHANCE OF BEING ALL SNOW. THE TIMING OF THE TRANSITION TO SNOW IS ALSO UP FOR DEBATE ON MONDAY WITH TIMING DIFFERENCES BETWEEN THE MODELS. WILL GO BELOW MOS GUIDANCE OF HIGHS ON MONDAY DUE TO FALLING PRECIPITATION. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... THE SUPPORT FROM THE STRENGTHENING 250 MB JET SHOULD BE TO OUR EAST BY MONDAY EVENING...WITH THE REINFORCING COLD ARCTIC AIR BLOWING IN. LIKE YESTERDAY AND THE DAY BEFORE THAT...WE WILL CONTINUE TO HOLD ONTO TO HIGHER POPS LONGER IN SOME ACCUMULATING SNOW SHOWERS MONDAY EVENING THAN MODEL GUIDANCE....AS DEW POINTS LOWER IN THE COLD AIR ADVECTION. DRIER ARCTIC AIR TAKES CONTROL FOR TUESDAY WITH LOW DEW POINTS. SO DESPITE THE 850 MB THERMAL TROF...DO NOT WANT TO BE AS PESSIMISTIC AS WE USUALLY ARE ON CLOUDS IN THE LOW LEVEL THERMAL TROF. YET...STILL LEFT SOME FLAKES IN THE AIR WELL THROUGH TUESDAY NIGHT FOR THE MOUNTAIN COUNTIES. COLDEST DAY MAXIMUM READINGS SHOULD BE TUESDAY. MOST LOWLAND READINGS IN THE 20S FOR MAXIMUM. OUR SMALL AREA AOA 4000 FEET SHOULD REMAIN IN SINGLE DIGITS DURING THE DAY ON TUESDAY. AN IDEAL CLEAR/CALM NIGHT MAY BE HARD TO FIND...SINCE HIGH PRESSURE CENTER NOT DIRECTLY OVER US. BUT WINDS SHOULD DIMINISH TUESDAY NIGHT. SO COLDEST TEMPERATURES FOR LOWLANDS LIKELY TUESDAY NIGHT/EARLY WEDNESDAY. CONTINUED DRY WEDNESDAY INTO THURSDAY. WARM AIR ADVECTION MOISTURE INCREASES THURSDAY NIGHT INTO FRIDAY. WILL HAVE CHANCE POPS SPREADING SW TO NE OVERNIGHT THURSDAY NIGHT INTO FRIDAY. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD EXCEPT FOR SOME LINGERING MVFR CIGS OVER KEKN EARLY THIS MORNING. AN INCREASE IN HIGH AND MIDDLE LEVEL CLOUDS CAN BE EXPECTED AS THE DAY PROGRESSES. THIS TREND CONTINUES TONIGHT WITH PASSAGE OF AN UPPER LEVEL DISTURBANCE. FLOW SURFACE AND ALOFT WILL BE LIGHT TODAY COURTESY OF HIGH PRESSURE. FLOW ALOFT INCREASES OUT OF SW 20 TO 25 KTS TONIGHT BUT SURFACE WINDS ACROSS TAF SITES WILL REMAIN LIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY... FORECAST CONFIDENCE: HIGH ALTERNATE SCENARIOS: NONE 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 H H H H H 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 H H H H H 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 H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z SUNDAY... IFR POSSIBLE SUNDAY NIGHT INTO TUESDAY IN PRECIPITATION AND CLOUDS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/RPY/30 NEAR TERM...SL/30 SHORT TERM...RPY LONG TERM...KTB AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
543 AM EST SAT NOV 15 2014 .SYNOPSIS... HIGH PRESSURE LINGERS TODAY. NEXT SYSTEM WITH DEEPER MOISTURE SUNDAY NIGHT INTO MONDAY. REINFORCING COLD AIR ARRIVES MONDAY NIGHT INTO TUESDAY. COLDEST DAY TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... 640 AM UPDATE... NO CHANGES ATTM. LOWEST TEMP I COULD FIND AT THIS HOUR WAS AN UNOFFICIAL OBSERVATION OF 8 DEGREES UP A HOLLOW NEAR TOWN OF BOLT IN SW RALEIGH COUNTY. BRRR. PREVIOUS DISCUSSION BELOW... STRATUS HANGING TOUGH OVER THE N MOUNTAINS ATTM WHICH IS KEEPING TEMPS UP AT EKN COMPARED A HAIR. EXPECT THESE CLOUDS TO DISSIPATE PER HRRR OVER THE NEXT SEVERAL HRS. ELSEWHERE...QUITE COLD WITH TEMPS RUNNING A BIT BLOW FCST CURVE IN THE OUTLYING AREAS. ADJUSTED HOURLY TEMPS AND MINT GRID DOWN A FEW DEGREES...ESPECIALLY AWAY FROM URBAN CENTERS. MID TEENS LOOK LIKE A GOOD BET ACROSS THESE LOCATIONS ACROSS THE LOWLANDS. IF THE CLOUDS OVER THE MOUNTAINS CAN CLEAR IN TIME...THEN SOME HIGH SINGLE NUMBERS ARE POSSIBLE OVER THE HIGH RIDGES. SNOWSHOE CURRENTLY SITTING AT 11F. AS FOR TODAY...THE SUN WILL FINALLY MAKE AN APPEARANCE...ALBEIT WITH A SHORT STAY. SOME CIRRUS WILL STREAK IN DURING THE FIRST HALF OF TODAY...FOLLOWED BY INCREASE IN MID LEVEL CLOUDS ASSOCIATED WAA ALOFT LATE IN THE AFTERNOON AND EARLY EVENING /FROM SW TO NE/. H85 TEMPS WILL MODERATE BY ALMOST 10 DEGREES TODAY. STILL...WITH H925 TEMPS STILL ON THE COOL SIDE...FELT ROLLING WITH COOLER GUIDANCE /A LA LOCAL IN HOUSE MOS/ WAS THE BEST OPTION. AS SUCH...HAVE SOME MID 30S FOR THE LOWLANDS WITH LOWER 30S FOR THE HIGH TERRAIN. BIGGEST IMPROVEMENT IN TEMPS COMPARED TO YESTERDAY WILL BE FELT IN THE HIGHER ELEVATIONS WHERE SNOWSHOE SHOULD MAKE A RUN TOWARD UPPER 20S LATE IN THE DAY VERSUS LOW TEENS OBSERVED YESTERDAY. A MID LEVEL DISTURBANCE WILL RACE THROUGH THE REGION TONIGHT. HOWEVER...WITH LITTLE FANFARE OTHER THAN THE INCREASE IN MIDDLE LEVEL CLOUDS. THE WAA ALOFT CONTINUES THOUGH...SO HAVE HIGHEST RIDGES HOLDING NEAR STEADY IF NOT RISING TOWARD MORNING WITH GENERALLY MID 20S IN THE LOWLANDS. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... A WAVE MOVING ACROSS SATURDAY NIGHT INTO SUNDAY SUFFERS FROM LACK OF LOW LEVEL MOISTURE. SHOULD SEE LOTS OF VIRGA...BUT QUESTIONABLE HOW MUCH MAKES IT TO THE GROUND. WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE CATEGORIES...SLOWING INCREASING AS THE COLUMN TRIES TO SATURATE. MAIN SYSTEM OF INTEREST ARRIVES SUNDAY NIGHT AND CONTINUES INTO MONDAY. SREF/NAM/ECMWF ARE THE WARMEST OF THE MODELS...WITH THE GFS AND CANADIAN ON THE COOLER SIDE. WILL RUN IN BETWEEN THE 2 CAMPS FOR NOW...KEEPING A BAND OF PRECIPITATION IN THE MIDDLE THAT COULD BE EITHER RAIN OR SNOW. THIS BASICALLY KEEPS MOST OF WV AND VA AS RAIN...WITH A TRANSITION ZONE ACROSS NORTHEAST KY/SOUTHEAST OH AND FAR NW WV. CENTRAL OH HAS THE BEST CHANCE OF BEING ALL SNOW. THE TIMING OF THE TRANSITION TO SNOW IS ALSO UP FOR DEBATE ON MONDAY WITH TIMING DIFFERENCES BETWEEN THE MODELS. WILL GO BELOW MOS GUIDANCE OF HIGHS ON MONDAY DUE TO FALLING PRECIPITATION. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... THE SUPPORT FROM THE STRENGTHENING 250 MB JET SHOULD BE TO OUR EAST BY MONDAY EVENING...WITH THE REINFORCING COLD ARCTIC AIR BLOWING IN. LIKE YESTERDAY AND THE DAY BEFORE THAT...WE WILL CONTINUE TO HOLD ONTO TO HIGHER POPS LONGER IN SOME ACCUMULATING SNOW SHOWERS MONDAY EVENING THAN MODEL GUIDANCE....AS DEW POINTS LOWER IN THE COLD AIR ADVECTION. DRIER ARCTIC AIR TAKES CONTROL FOR TUESDAY WITH LOW DEW POINTS. SO DESPITE THE 850 MB THERMAL TROF...DO NOT WANT TO BE AS PESSIMISTIC AS WE USUALLY ARE ON CLOUDS IN THE LOW LEVEL THERMAL TROF. YET...STILL LEFT SOME FLAKES IN THE AIR WELL THROUGH TUESDAY NIGHT FOR THE MOUNTAIN COUNTIES. COLDEST DAY MAXIMUM READINGS SHOULD BE TUESDAY. MOST LOWLAND READINGS IN THE 20S FOR MAXIMUM. OUR SMALL AREA AOA 4000 FEET SHOULD REMAIN IN SINGLE DIGITS DURING THE DAY ON TUESDAY. AN IDEAL CLEAR/CALM NIGHT MAY BE HARD TO FIND...SINCE HIGH PRESSURE CENTER NOT DIRECTLY OVER US. BUT WINDS SHOULD DIMINISH TUESDAY NIGHT. SO COLDEST TEMPERATURES FOR LOWLANDS LIKELY TUESDAY NIGHT/EARLY WEDNESDAY. CONTINUED DRY WEDNESDAY INTO THURSDAY. WARM AIR ADVECTION MOISTURE INCREASES THURSDAY NIGHT INTO FRIDAY. WILL HAVE CHANCE POPS SPREADING SW TO NE OVERNIGHT THURSDAY NIGHT INTO FRIDAY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD EXCEPT FOR SOME LINGERING MVFR CIGS OVER KEKN EARLY THIS MORNING. AN INCREASE IN HIGH AND MIDDLE LEVEL CLOUDS CAN BE EXPECTED AS THE DAY PROGRESSES. THIS TREND CONTINUES TONIGHT WITH PASSAGE OF AN UPPER LEVEL DISTURBANCE. FLOW SURFACE AND ALOFT WILL BE LIGHT TODAY COURTESY OF HIGH PRESSURE. FLOW ALOFT INCREASES OUT OF SW 20 TO 25 KTS TONIGHT BUT SURFACE WINDS ACROSS TAF SITES WILL REMAIN LIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY... FORECAST CONFIDENCE: HIGH ALTERNATE SCENARIOS: NONE 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 H 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 H H H H H 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 H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z SUNDAY... IFR POSSIBLE SUNDAY NIGHT INTO TUESDAY IN PRECIPITATION AND CLOUDS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/RPY/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...KTB AVIATION...30
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
535 AM CST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 415 AM CST SAT NOV 15 2014 FOCUS ON THE SNOW EVENT CURRENTLY UNDERWAY ACROSS OUR WESTERN CWA... EXPECTED TO PROGRESS EAST THROUGH THE REGION OVER THE NEXT 24 HOURS. OVERALL LOOKING AT A BROAD ISENTROPIC UPGLIDE AHEAD OF OPEN WAVE...WHICH SHOULD RESULT IN FAIRLY UNIFORM SNOW AMOUNTS ACROSS THE REGION. HOWEVER...CURRENT RADAR SHOWING A COUPLE MORE DISTINCT BANDS NEAR MID LEVEL /750-650MB/ FRONTAL BOUNDARIES PER RAP MODEL...SO COULD SEE SOME AREAS OF ENHANCEMENT THROUGHOUT THE DAY. FRONTOGENESIS APPEARS TO BE FAIRLY TRANSIENT THOUGH...SO DO NOT EXPECT HEAVIER BANDS TO SIT IN ANY ONE LOCATION FOR PROLONGED PERIOD OF TIME. NORTHERN BAND APPEARS TO BE A LITTLE FARTHER NORTH THAN PREVIOUSLY EXPECTED THOUGH...AIMING TOWARD THE HIGHWAY 14 CORRIDOR THROUGH THE MORNING. HAVE BUMPED UP SNOW AMOUNTS A BIT IN THESE AREAS AS A RESULT...AND EXPANDED ADVISORY NORTHWARD TO COVER ENTIRE CWA FOR WIDESPREAD 3 TO 5 INCHES. IN ADDITION TO POTENTIALLY HIGHER BANDS...CONCERN FOR THIS EVENT IS HIGH SNOW RATIOS GIVEN STRONG LIFT WITHIN DEEP DENDRITIC LAYER... AND LIGHT WINDS ALLOWING DENDRITIC SNOW FLAKES TO HOLD TOGETHER. GENERALLY STICKING WITH 16-18:1 RATIOS FOR BULK OF THE SNOWFALL... BUT SOME MODELS INDICATE A BIT HIGHER...WHICH COULD PUSH AMOUNTS CLOSER TO 6 INCH RANGE IN SOME AREAS. STILL EXPECT SNOW TO BE DONE IN MOST AREAS BY MID-LATE EVENING...BUT WAVE IS A BIT SLOWER IN DEPARTING THIS EVENING...SO EXTENDED ADVISORY TIMING IN OUR FAR EAST THROUGH MIDNIGHT TONIGHT. GIVEN FLUFFY NATURE OF SNOWFALL... COULD SEE A LITTLE BLOWING/DRIFTING OF FRESH SNOW AS NORTHWEST WINDS PICK UP BEHIND THE FRONT ACROSS OUR SOUTHWEST AREAS THIS AFTERNOON AND EVENING...AND WILL CONTINUE MENTION OF PATCHY BLOWING SNOW THROUGH PARTS OF THE MISSOURI RIVER VALLEY. STRONGER WINDS OCCUR AFTER BULK OF ACCUMULATION IS OVER THOUGH...SO AT THIS TIME HAVE NOT EXTENDED HEADLINES TO COVER ANY BLOWING SNOW THREAT. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 415 AM CST SAT NOV 15 2014 ON SUNDAY...INTENSIFYING LOW PRESSURE TRACKING THROUGH THE UPPER MISSISSIPPI VALLEY/WESTERN GREAT LAKES REGION WILL PULL A COLD FRONT THROUGH OUR AREA IN THE AFTERNOON. WHILE WINDS WILL INITIALLY BE OUT OF THE WEST/SOUTHWEST EARLY IN THE DAY...THEY WILL TURN AROUND TO THE NORTHWEST WITH THE PASSAGE OF THE SYSTEM...AND PICK UP IN A COLD AIR ADVECTION REGIME. WITH THIS...GUSTS WILL RAMP UP TO 20 TO 30 KTS ACROSS THE AREA. IN RESPONSE TO THIS...WILL BEGIN TO HAVE AREAS OF BLOWING SNOW WITH FRESH SNOW COVER ON THE GROUND. WILL ALSO SEE THE POSSIBILITY OF SCATTERED FLURRIES OVER PORTIONS OF THE AREA WITH SOME CLOUD COVER AND VERY COLD THERMAL PROFILES SUPPORTIVE OF DENDRITIC GROWTH. IN A THE WEST/SOUTHWESTERLY FLOW OUT AHEAD OF THE FRONT...THE MISSOURI RIVER VALLEY WILL HAVE THE OPPORTUNITY TO WARM INTO THE MID 20S BEFORE BEGINNING TO DROP OFF IN THE AFTERNOON AS THE COLDER AIR FEEDS INTO THE AREA. BACK TO THE NORTH AND EAST...HIGHS WILL ONLY MAKE IT INTO THE UPPER TEENS TO LOWER 20S. STRONG GUSTY NORTHWESTERLY WINDS WILL PERSIST FOR SUNDAY NIGHT AND MONDAY...KEEPING THE POSSIBILITY OF BLOWING SNOW ACROSS THE AREA THROUGH THE PERIOD. THE WINDS WILL KEEP TEMPERATURES FROM DROPPING OFF TOO DRAMATICALLY ON SUNDAY NIGHT...THOUGH STILL COLD WITH LOWS IN THE SINGLE DIGITS. IN AN INCREASINGLY COLD AIRMASS WITH MONDAY 925 MB TEMPERATURES PROGGED TO BE JUST EITHER SIDE OF -15 C...IT WILL BE A BITTERLY COLD DAY WITH HIGHS IN THE LOWER TO MID TEENS. WITH THE AFOREMENTIONED WINDS...WIND CHILLS WILL BE FIERCE...RUNNING IN THE SINGLE DIGITS BELOW ZERO TO TEENS BELOW ZERO. WINDS WILL THEN RAMP DOWN ON MONDAY NIGHT AS A SURFACE RIDGE AXIS SLIDES CLOSER TO THE AREA...BRINGING AN END TO ANY BLOWING SNOW. STILL ENOUGH WIND HOWEVER TO KEEP OVERNIGHT LOWS SOMEWHAT IN CHECK...BOTTOMING OUT JUST EITHER SIDE OF ZERO. FOR THE REMINDER OF NEXT WEEK...THERE WILL BE A SLIGHT MODERATION OF TEMPERATURES...ALBEIT STILL MUCH BELOW NORMAL...IN A NORTHWESTERLY UPPER LEVEL FLOW. THIS WOULD BE MOST APPARENT TOWARD THE END OF THE WEEK WHEN HIGHS ON FRIDAY COULD CLOSE IN ON THE LOWER 30S THROUGH THE MISSOURI RIVER VALLEY. THERE DOES NOT APPEAR TO BE ANY SIGNIFICANT PRECIPITATION PRODUCERS THROUGH THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 535 AM CST SAT NOV 15 2014 WIDESPREAD MVFR-IFR CONDITIONS EXPECTED TODAY WITH SNOW MOVING THROUGH THE REGION. CONDITIONS SHOULD GRADUALLY IMPROVE WEST TO EAST AFTER 16/00Z AS SNOW COMES TO AN END BEHIND DEPARTING UPPER WAVE AND ASSOCIATED FRONT. WINDS GENERALLY AT OR BELOW 10KT WITH THE SNOW...BUT EXPECTED TO INCREASE WITH GUSTS 15-25KT AS WINDS BECOME NORTHWESTERLY IN THE LATE AFTERNOON/EVENING. GUSTY WINDS WILL LIKELY CREATE DRIFTING ACROSS RUNWAYS...AND COULD PRODUCE LINGERING MVFR VISIBILITY IN BLOWING SNOW AT TIMES. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR SDZ039- 040-054>056-060>062-065>071. WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR SDZ038- 050-052-053-057>059-063-064. MN...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ071- 072-080-089-097-098. WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR MNZ081-090. IA...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR IAZ001- 012-020-031. WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR IAZ002-003-013-014-021-022-032. NE...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NEZ013- 014. && $$ SHORT TERM...JH LONG TERM...JM AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
415 AM CST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 415 AM CST SAT NOV 15 2014 FOCUS ON THE SNOW EVENT CURRENTLY UNDERWAY ACROSS OUR WESTERN CWA... EXPECTED TO PROGRESS EAST THROUGH THE REGION OVER THE NEXT 24 HOURS. OVERALL LOOKING AT A BROAD ISENTROPIC UPGLIDE AHEAD OF OPEN WAVE...WHICH SHOULD RESULT IN FAIRLY UNIFORM SNOW AMOUNTS ACROSS THE REGION. HOWEVER...CURRENT RADAR SHOWING A COUPLE MORE DISTINCT BANDS NEAR MID LEVEL /750-650MB/ FRONTAL BOUNDARIES PER RAP MODEL...SO COULD SEE SOME AREAS OF ENHANCEMENT THROUGHOUT THE DAY. FRONTOGENESIS APPEARS TO BE FAIRLY TRANSIENT THOUGH...SO DO NOT EXPECT HEAVIER BANDS TO SIT IN ANY ONE LOCATION FOR PROLONGED PERIOD OF TIME. NORTHERN BAND APPEARS TO BE A LITTLE FARTHER NORTH THAN PREVIOUSLY EXPECTED THOUGH...AIMING TOWARD THE HIGHWAY 14 CORRIDOR THROUGH THE MORNING. HAVE BUMPED UP SNOW AMOUNTS A BIT IN THESE AREAS AS A RESULT...AND EXPANDED ADVISORY NORTHWARD TO COVER ENTIRE CWA FOR WIDESPREAD 3 TO 5 INCHES. IN ADDITION TO POTENTIALLY HIGHER BANDS...CONCERN FOR THIS EVENT IS HIGH SNOW RATIOS GIVEN STRONG LIFT WITHIN DEEP DENDRITIC LAYER... AND LIGHT WINDS ALLOWING DENDRITIC SNOW FLAKES TO HOLD TOGETHER. GENERALLY STICKING WITH 16-18:1 RATIOS FOR BULK OF THE SNOWFALL... BUT SOME MODELS INDICATE A BIT HIGHER...WHICH COULD PUSH AMOUNTS CLOSER TO 6 INCH RANGE IN SOME AREAS. STILL EXPECT SNOW TO BE DONE IN MOST AREAS BY MID-LATE EVENING...BUT WAVE IS A BIT SLOWER IN DEPARTING THIS EVENING...SO EXTENDED ADVISORY TIMING IN OUR FAR EAST THROUGH MIDNIGHT TONIGHT. GIVEN FLUFFY NATURE OF SNOWFALL... COULD SEE A LITTLE BLOWING/DRIFTING OF FRESH SNOW AS NORTHWEST WINDS PICK UP BEHIND THE FRONT ACROSS OUR SOUTHWEST AREAS THIS AFTERNOON AND EVENING...AND WILL CONTINUE MENTION OF PATCHY BLOWING SNOW THROUGH PARTS OF THE MISSOURI RIVER VALLEY. STRONGER WINDS OCCUR AFTER BULK OF ACCUMULATION IS OVER THOUGH...SO AT THIS TIME HAVE NOT EXTENDED HEADLINES TO COVER ANY BLOWING SNOW THREAT. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 415 AM CST SAT NOV 15 2014 ON SUNDAY...INTENSIFYING LOW PRESSURE TRACKING THROUGH THE UPPER MISSISSIPPI VALLEY/WESTERN GREAT LAKES REGION WILL PULL A COLD FRONT THROUGH OUR AREA IN THE AFTERNOON. WHILE WINDS WILL INITIALLY BE OUT OF THE WEST/SOUTHWEST EARLY IN THE DAY...THEY WILL TURN AROUND TO THE NORTHWEST WITH THE PASSAGE OF THE SYSTEM...AND PICK UP IN A COLD AIR ADVECTION REGIME. WITH THIS...GUSTS WILL RAMP UP TO 20 TO 30 KTS ACROSS THE AREA. IN RESPONSE TO THIS...WILL BEGIN TO HAVE AREAS OF BLOWING SNOW WITH FRESH SNOW COVER ON THE GROUND. WILL ALSO SEE THE POSSIBILITY OF SCATTERED FLURRIES OVER PORTIONS OF THE AREA WITH SOME CLOUD COVER AND VERY COLD THERMAL PROFILES SUPPORTIVE OF DENDRITIC GROWTH. IN A THE WEST/SOUTHWESTERLY FLOW OUT AHEAD OF THE FRONT...THE MISSOURI RIVER VALLEY WILL HAVE THE OPPORTUNITY TO WARM INTO THE MID 20S BEFORE BEGINNING TO DROP OFF IN THE AFTERNOON AS THE COLDER AIR FEEDS INTO THE AREA. BACK TO THE NORTH AND EAST...HIGHS WILL ONLY MAKE IT INTO THE UPPER TEENS TO LOWER 20S. STRONG GUSTY NORTHWESTERLY WINDS WILL PERSIST FOR SUNDAY NIGHT AND MONDAY...KEEPING THE POSSIBILITY OF BLOWING SNOW ACROSS THE AREA THROUGH THE PERIOD. THE WINDS WILL KEEP TEMPERATURES FROM DROPPING OFF TOO DRAMATICALLY ON SUNDAY NIGHT...THOUGH STILL COLD WITH LOWS IN THE SINGLE DIGITS. IN AN INCREASINGLY COLD AIRMASS WITH MONDAY 925 MB TEMPERATURES PROGGED TO BE JUST EITHER SIDE OF -15 C...IT WILL BE A BITTERLY COLD DAY WITH HIGHS IN THE LOWER TO MID TEENS. WITH THE AFOREMENTIONED WINDS...WIND CHILLS WILL BE FIERCE...RUNNING IN THE SINGLE DIGITS BELOW ZERO TO TEENS BELOW ZERO. WINDS WILL THEN RAMP DOWN ON MONDAY NIGHT AS A SURFACE RIDGE AXIS SLIDES CLOSER TO THE AREA...BRINGING AN END TO ANY BLOWING SNOW. STILL ENOUGH WIND HOWEVER TO KEEP OVERNIGHT LOWS SOMEWHAT IN CHECK...BOTTOMING OUT JUST EITHER SIDE OF ZERO. FOR THE REMINDER OF NEXT WEEK...THERE WILL BE A SLIGHT MODERATION OF TEMPERATURES...ALBEIT STILL MUCH BELOW NORMAL...IN A NORTHWESTERLY UPPER LEVEL FLOW. THIS WOULD BE MOST APPARENT TOWARD THE END OF THE WEEK WHEN HIGHS ON FRIDAY COULD CLOSE IN ON THE LOWER 30S THROUGH THE MISSOURI RIVER VALLEY. THERE DOES NOT APPEAR TO BE ANY SIGNIFICANT PRECIPITATION PRODUCERS THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1048 PM CST FRI NOV 14 2014 THROUGH 15Z CEILINGS AND VISIBILITIES WILL LOWER FROM THE WEST FROM VFR TO AROUND 1K FEET AND BELOW 3SM IN SNOW. FROM 15/20Z TO 16/06Z CONDITIONS WILL IMPROVE SLOWLY FROM THE WEST TO CEILINGS 2-3K FEET AND VISIBILITY GREATER THAN 5SM AS SNOW ENDS. WEST OF A BKX/FSD/SUX LINE...SKIES WILL CLEAR FROM THE WEST 16/00Z-06Z. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR SDZ039- 040-054>056-060>062-065>071. WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR SDZ038- 050-052-053-057>059-063-064. MN...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ071- 072-080-089-097-098. WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR MNZ081-090. IA...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR IAZ001- 012-020-031. WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR IAZ002-003-013-014-021-022-032. NE...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NEZ013- 014. && $$ SHORT TERM...JH LONG TERM...JM AVIATION...
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
958 AM CST SAT NOV 15 2014 .UPDATE... MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST TODAY AS A SHORTWAVE APPROACHES. THE FORECAST SNOWFALL SEEMS TO BE ON TRACK GIVEN UPSTREAM CONDITIONS AND THE 12Z NAM. LATEST NAM AND RAP SOUNDINGS SUGGEST THE SNOW WILL START IN THE WEST BY 4 PM AND IN THE EAST BY 6 PM. STILL LOOKS LIKE THE BULK OF SNOW WILL FALL PRIOR TO MIDNIGHT...WITH SOME LINGERING LIGHT ACCUMULATIONS THROUGH THE REMAINDER OF THE NIGHT. STORM TOTALS OF 1 TO 2 INCHES STILL LOOKS ABOUT RIGHT. && .AVIATION/18Z TAFS/... MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST TODAY AS A SHORTWAVE APPROACHES. LATEST NAM AND RAP SOUNDINGS SUGGEST THE SNOW WILL START IN THE WEST BY 4 PM AND IN THE EAST BY 6 PM. STILL LOOKS LIKE THE BULK OF SNOW WILL FALL PRIOR TO MIDNIGHT...WITH SOME LINGERING LIGHT ACCUMULATIONS THROUGH THE REMAINDER OF THE NIGHT. STORM TOTALS OF 1 TO 2 INCHES STILL LOOKS ABOUT RIGHT. IT WILL BE A DRY SNOW...WITH LIQUID TO SNOW RATIOS OF AROUND 17 TO 1. UPSTREAM OBS AND SOUNDINGS SUGGEST IFR/MVFR CIGS WITH THE SNOWFALL...WITH VSBYS DROPPING TO 1 TO 2 MILES...POSSIBLY BRIEFLY DOWN TO 1/2SM. LOOKS LIKE MVFR CIGS MAY LINGER FOR MUCH OF SUNDAY...AS A SECOND SHORTWAVE MOVES THROUGH WHILE A THIRD WAVE APPROACHES. WILL PROBABLY SEE A LITTLE LIGHT SNOW AT TIMES SUNDAY...BUT NOT EXPECTING ADDITIONAL ACCUMULATIONS. && .PREV DISCUSSION... /ISSUED 330 AM CST SAT NOV 15 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH. MID LEVEL CLOUDS OVER NRN IL AND WEST OF THE MS RIVER ASSOCIATED WITH LEADING EDGE OF MID LEVEL WARM ADVECTION. WARM ADVECTION PATTERN IS AHEAD OF A SHORTWAVE TROUGH OVER CO AND A STRONGER WAVE OVER MT/IDAHO. THE CO SHORTWAVE WILL LIFT NEWD AND MOVE ACROSS SRN WI THIS EVENING. WEAK MID LEVEL WARM ADVECTION AND FRONTOGENESIS IS EXPECTED DURING THIS TIME BUT THE PVA IS MORE PRONOUNCED. THE LARGER UPPER TROUGH WILL THEN MOVE INTO WEST CENTRAL WI BY 12Z SUN BUT THE 500 MB DRY SLOT WILL KEEP THE SNOW VERY LIGHT. THUS MOST OF THE SNOW ACCUMULATIONS WILL OCCUR FROM LATE THIS AFTERNOON INTO THE EVENING HOURS. QPF TOTALS ARE RANGING FROM 0.08-0.12 INCHES WITH HIGH SNOW RATIOS DUE TO THE VERY COLD TROPOSPHERE. SNOW TOTALS OF 1-2 INCHES ARE EXPECTED WITH THE HIGHER VALUES OVER THE WRN CWA. HIGH TEMPS TO REMAIN IN THE MID TO UPPER 20S TODAY WITH THE INCREASING CLOUDS. THE CLOUDS...SNOW...AND WEAK WARM ADVECTION TNT WILL KEEP TEMPS IN THE LOWER 20S FOR MOST OF THE NIGHT. SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. MODELS IN GOOD AGREEMENT WITH 500 MB VORTICITY MAXIMUM SLIDING EAST ACROSS THE AREA DURING THE MORNING...THEN SLOWLY TO THE EAST OF THE AREA IN THE AFTERNOON. AREA FORECAST SOUNDINGS SHOW ENOUGH DEEP MOISTURE WITHIN DEEP DENDRITE SNOW GROWTH ZONE TO MAINTAIN LOWER END POPS IN THE NORTH AND EAST DURING THE MORNING. MAY SEE SOME FLURRIES IN THE AFTERNOON WITH STEEP LOW LEVEL LAPSE RATES AND SOME LINGERING MOISTURE. SKIES SHOULD BECOME PARTLY SUNNY IN THE AFTERNOON. COLD HIGHS IN THE UPPER 20S TO LOWER 30S ARE EXPECTED. ARCTIC COLD FRONT MOVES EAST THROUGH THE AREA BY EARLY SUNDAY EVENING...WITH STRONG COLD AIR ADVECTION SUNDAY NIGHT INTO MONDAY ACROSS THE AREA. THIS WILL BRING AN EVEN COLDER AIRMASS INTO THE REGION. 925 MB TEMPERATURES SUGGEST HIGHS ONLY IN THE UPPER TEENS TO LOWER 20S MONDAY...WITH LOWS SUNDAY NIGHT INTO THE TEENS AND MONDAY NIGHT IN THE 8 TO 13 ABOVE ZERO RANGE. TIGHT PRESSURE GRADIENT WITH DEEPENING LOW TO THE NORTH WILL BRING GUSTY WEST WINDS...WHICH WILL BRING WIND CHILLS DOWN INTO THE SINGLE DIGITS SUNDAY NIGHT...AND THE SINGLE DIGITS BELOW ZERO MONDAY NIGHT. MODELS GENERALLY SHOWING A 500 MB LOW DEVELOPING OVER NORTHERN MINNESOTA BY SUNDAY NIGHT...THEN MOVING EAST OVER LAKE SUPERIOR ON MONDAY. A 500 MB VORTICITY MAXIMUM SHIFTS EAST THROUGH THE AREA SUNDAY NIGHT...WITH MORE VORTICITY MAXIMA MOVING THROUGH ON MONDAY. AREA FORECAST SOUNDINGS SHOW ENOUGH LOW LEVEL MOISTURE AND STEEP LAPSE RATES WITHIN DENDRITE SNOW GROWTH ZONE TO MAINTAIN POPS FOR SNOW SHOWERS SUNDAY NIGHT INTO MONDAY. LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM. GFS/ECMWF GENERALLY KEEP THE REGION WITHIN NORTHWEST FLOW AT 500 MB THROUGH THE REST OF THE WEEK. THIS SHOULD KEEP THE REGION COLD DURING THIS TIME. 500 MB SHORTWAVE TROUGH SLIDES SOUTHEAST THROUGH THE AREA TUESDAY NIGHT...WITH A TRAILING VORTICITY MAXIMUM CLIPPING OR SHIFTING THROUGH THE REGION WEDNESDAY. MOISTURE IS MODEST DURING THIS TIME...SO KEPT JUST LOW END POPS IN THE NORTH AND NORTHEAST DURING THIS TIME. MODELS THEN DIFFER MORE LATER IN THE WEEK WITH TRENDS...SO USED CONSENSUS POPS AND TEMPERATURES FOR NOW. AVIATION/12Z TAFS/... VFR CONDITIONS UNTIL THE LIGHT SNOW STARTS FROM WEST TO EAST ACROSS SRN WI DURING THE LATE AFTERNOON. CIGS TO FALL TO 1-2 KFT WITH VSBYS OF 1-2 MILES WITH THE SNOW INTO THE EVENING HOURS. THE HEAVIEST SNOW WILL END BY LATE EVENING BUT VERY LIGHT SNOW WILL CONTINUE AT TIMES FROM THE LATE EVENING THROUGH THE OVERNIGHT. VSBYS DURING THIS TIME WILL RANGE FROM 3-5SM BUT MAY RISE TO P6SM BEFORE 12Z SUN. LOW STRATUS TO CONTINUE INTO SUN AM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DDV TODAY/TONIGHT AND AVIATION...GEHRING SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
433 AM MST SAT NOV 15 2014 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 253 AM MST SAT NOV 15 2014 MAIN CONCERN IN THE NEAR TERM IS ACCUMULATING SNOW ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINTER WEATHER ADVISORIES LOOK GOOD AND HAVE MADE NO CHANGES WITH THE MORNING FCST PACKAGE. HAVE SEEN A RELATIVE LULL IN SNOW SHOWERS OVERNIGHT WITH SUBSIDENCE AND SOMEWHAT DRY AIR ALOFT. HOWEVER...POTENT MIDLVL SHORTWAVE EVIDENT ON MORNING WATER VAPOR LOOP OVER THE PAC NW WILL MOVE SOUTHEAST TODAY. COOLING CLOUD TOPS OVER CENTRAL WY SUGGEST AN UPTICK IN PCPN COVERAGE OVER THE NEXT FEW HOURS...SO WILL KEEP CATEGORICAL POPS GOING. LOOKING AT TWO DISTINCT AREAS OF SNOW ACCUMULATIONS. FIRST ACROSS THE NORTHERN TIER OF COUNTIES WITH FRONTOGENESIS ALONG THE SFC FRONT. SECOND ALONG AND WEST OF THE LARAMIE RANGE WITHIN THE LEFT EXIT REGION OF A 105 KT H25 JET STREAK NOW ENTERING NORTHERN UT. BOTH AREAS COINCIDE WELL WITH A MIDLVL MOISTURE PLUME OVERSPREADING THE CWA. A GENERAL 2 TO 5 INCH SNOWFALL SEEMS PROBABLE IN THESE CORRIDORS. EVEN IF WE DO NOT SEE ADVISORY CRITERIA AMOUNTS...NORTHWEST WINDS WILL GUST IN EXCESS OF 30 MPH TODAY WHICH WILL CREATE BLOWING/DRIFTING. WEBCAMS ALREADY LOOK QUITE NASTY IN THE RAWLINS IN ELK MOUNTAIN AREAS AS OF 09Z THIS MORNING. THOUGHT ABOUT A TEMPORAL EXTENTION OF THE ADVISORY THROUGH THE AFTN FOR BLOWING SNOW AFTER ACCUMULATIONS END...BUT WILL LET THE DAY SHIFT MONITOR CONDITIONS TO SEE JUST HOW BAD VISIBILITY BECOMES LATER ON. SNOW HAS BEEN DIFFICULT TO COME BY IN THE CHEYENNE AREA SO FAR. IT STILL LOOKS LIKE WE HAVE A WINDOW OF OPPORTUNITY IN THE 12-15Z TIME FRAME AS THE NAM SHOWS A BAND OF MODERATE H7 FRONTOGENESIS FROM THE SOUTHERN LARAMIE RANGE EAST INTO KIMBALL COUNTY NE. MAY BE ENOUGH FOR A QUICK 1 TO 2 INCHES...BUT NOT MUCH MORE. WITH NORTHWEST WINDS GUSTING 25 TO 35 MPH...DAY SHIFT MIGHT NEED TO CONSIDER A BLOWING SNOW ADVISORY FOR CENTRAL AND EASTERN LARAMIE COUNTY. THE MOUNTAINS STILL LOOK PRIME FOR 8 TO 12 INCHES OF TOTAL ACCUMULATION. NVA WILL SPREAD ACROSS THE AREA BY LATE AFTN...SO EXPECT A GRADUAL DECREASE IN PCPN COVERAGE FROM NORTHWEST TO SOUTHEAST THROUGH EARLY EVE. DRY AFTER 00Z OUTSIDE OF A FEW FLURRIES. STRONG LLVL COLD AIR ADVECTION WILL CONTINUE TODAY WITH THE FROPA...WITH GFS H7 TEMPS PLUNGING TO THE -17C TO -20C RANGE BY 00Z SUN. SURFACE TEMPS WILL MOST LIKELY HOLD STEADY TODAY OR EVEN FALL SLIGHTLY INTO THE AFTN. DRYING ALOFT SIGNALS CLEARING INTO TONIGHT...AND WITH FRESH SNOWPACK COMES VERY COLD TEMPERATURES TONIGHT. GUSTY WEST WINDS MIGHT KEEP THINGS MIXED ENOUGH TO PREVENT TEMPERATURES FROM REALLY TANKING...BUT IT WILL BE SUFFICIENT FOR DANGEROUS WIND CHILLS BETWEEN -20 AND -30F. EXPECT WIND CHILL ADVISORIES WILL BE NECESSARY. BOTH THE NAM AND GFS SUGGEST A FAIRLY POTENT SHORTWAVE DIVING SOUTH ACROSS THE WESTERN DAKOTAS ON SUN AFTN. WHILE THIS DOES PROVIDE A REINFORCING SHOT OF COLD AIR...THE GOOD CAA DOES NOT ARRIVE UNTIL LATE. AS SUCH...EXPECT A PERIOD OF GUSTY WEST/DOWNSLOPE WINDS EAST OF THE LARAMIE RANGE TO CONTRIBUTE TO COMPRESSIONAL WARMING THROUGH EARLY AFTN. TRENDED HIGHER FOR MAX TEMPS BECAUSE OF THIS. MOISTENING ALOFT AND STRONG PVA SUGGESTS LIGHT SNOW SHOWERS ACROSS OUR NORTHERN AND EASTERN ZONES...SO ADDED LOW-END POPS THERE. COOLER FOR MON WITH CYCLONIC FLOW ALOFT AND SURFACE HIGH PRESSURE ENCOMPASSING MUCH OF THE CENTRAL AND NORTHERN ROCKIES. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 253 AM MST SAT NOV 15 2014 LONG TERM LOOKS DRY FOR THE MOST PART WITH TEMPERATURES BACK TO NEAR NORMAL FOR THIS TIME OF YEAR. WE STAY IN A NORTHWEST FLOW THAT COULD BRING SOME QUICK HITTING SNOW SHOWERS MOSTLY TO THE MOUNTAINS. THE MOST PROMINENT BEING THURSDAY. ECMWF ADVERTISING THIS WITH THE GFS SOLUTION ON THE SHORTWAVE FURTHER NORTH AND EAST OF OUR CWFA. DID KEEP SOME LOW CHANCE POPS IN THE FORECAST FOR THE MOUNTAINS. MOST OTHER PLACES DRY THROUGH FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 430 AM MST SAT NOV 15 2014 BASED 12Z TERMINAL FORECASTS OFF THE LATEST HRRR FORECAST. CURRENT MOSAIC RADAR SHOWING SNOW SHOWERS INCREASING IN COVERAGE. SEEING BAND OF MORE INTENSE SNOW JUST NORTH OF KCYS THIS MORNING THAT IS MOVING SOUTH...SO KCYS SHOULD BE COMING DOWN HARD OVER THE NEXT HOUR OR SO. MORNING HOURS THROUGH 18Z WILL SEE THE MOST WIDESPREAD IFR/LIFR CONDITIONS ACROSS SOUTHEAST WYOMING AND NEBRASKA PANHANDLE WITH IMPROVING CONDITIONS AFTERWARDS. && .FIRE WEATHER... ISSUED AT 253 AM MST SAT NOV 15 2014 NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND. ANOTHER ARCTIC SYSTEM WILL BRING SNOW ACROSS MOST AREAS THROUGH SATURDAY. SEVERAL INCHES OF SNOW WILL ACCUMULATE...ESPECIALLY IN THE HIGHER ELEVATIONS OF SOUTHERN WYOMING. THIS SNOW WILL BE FOLLOWED BY BRISK SURFACE WIND AND COLD TEMPERATURES SUNDAY INTO SUNDAY NIGHT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR WYZ101>103-112-114. WINTER WEATHER ADVISORY UNTIL 1 PM MST THIS AFTERNOON FOR WYZ104>106-109>111-113-115>117. NE...WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR NEZ002- 095. && $$ SHORT TERM...CLH LONG TERM...GCC AVIATION...GCC FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
330 PM MST SAT NOV 15 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 330 PM MST SAT NOV 15 2014 ...WIDESPREAD SNOW TO IMPACT THE REGION TONIGHT... COLD FRONT HAS ALREADY DROPPED THROUGH SOUTHEAST COLORADO THOUGH CORE OF COLDER AIR IS STILL SITTING ACROSS NORTHEAST COLORADO AND NORTHERN EL PASO COUNTY WHERE TEMPERATURES ARE IN THE TEENS (VS. THE UPPER 20S AND 30S ACROSS THE REMAINDER OF THE SOUTHEAST PLAINS). MAIN UPPER TROF IS CURRENTLY ACROSS WY/ID AND WILL CONTINUE DROPPING SOUTHWARD INTO THE 4 CORNERS REGION TONIGHT. UPPER JET ACROSS CO HAS LED TO SOME BANDED SNOW ACROSS NORTHEAST COLORADO...WITH SOME PERIODIC LIGHT SNOW CONTINUING ACROSS THE NORTHERN PORTIONS OF MONUMENT HILL WHERE MOST OF THE FORCING IS LIKELY DUE TO SHALLOW OROGRAPHICS. SNOW ALSO CONTINUES ALONG THE CONTINENTAL DIVIDE...THOUGH INTENSITIES HAVE LET UP QUITE A BIT FROM THIS MORNING. THAT WILL BE CHANGING IN THE NEXT 6 HOURS THOUGH AS DYNAMICS FROM THE UPPER TROF SHIFTS SOUTHWARD WITH TIME. BEST QG FORCING APPEARS TO DROP THROUGH THE WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA. CHALLENGES STILL REVOLVE AROUND SNOW AMOUNTS. MODELS APPEAR TO BE STRUGGLING THE MOST ACROSS THE PIKES PEAK REGION...WITH GFS PREDICTING A HEALTHY 3-7 INCHES ACROSS THIS REGION...WHILE NAM12 HAS MORE IN THE 1 TO 3 INCH RANGE. RAP IS GOING ALONG WITH GFS...WHILE ECMWF AND OTHER HIGH RES MODELS (ARW..NMM) AGREE MORE WITH THE NAM. SO HAVE TO HUNT FOR CLUES TO SUGGEST WHERE TO PUT THE NORTHERN EDGE OF THE HEADLINE AREAS. GIVEN THE TRACK OF THE UPPER FORCING IS FARTHER TO THE SOUTH...AND THE BEST UPGLIDE OVER THE H7 FRONT SEEMS TO BE MORE ACROSS SOUTHERN AREAS...HAVE LEFT PIKES PEAK AND EL PASO COUNTY OUT OF THE ADVISORY AREA FOR NOW. SNOWFALL GRIDS WILL CARRY AROUND 2-5 INCHES WITH SOUTHERN EL PASO COUNTY MORE IN THE 2 TO 3 INCH RANGE. WHERE MODELS AGREE BETTER IS ACROSS THE SOUTHEAST MOUNTAINS AND SOUTHERN I-25 CORRIDOR. HAVE EXPANDED THE ADVISORIES NORTHWARD AND EASTWARD A TAD. PUEBLO COUNTY IS ALWAYS A CHALLENGE AS HEAVIER AMOUNTS MAY END UP ACROSS SOUTHERN AND WESTERN PORTIONS OF THE COUNTY WHILE NORTHEAST PORTIONS SEE MORE IN THE 1-3 INCH RANGE. ALL THE MODELS SEEM TO HIT THE SOUTHERN SANGRES WITH THE HEAVIEST AMOUNTS OF QPF...AND THIS LOOKS REASONABLE GIVEN THE TRACK OF THE SYSTEM. THUS HAVE UPGRADED THE WINTER WEATHER ADVISORY TO A WARNING FOR THE SOUTHERN SANGRES. HAVE ALSO ADDED EASTERN LAS ANIMAS COUNTY TO THE ADVISORY WHERE THE NORTHERN SLOPES OF THE RATON WILL HAVE THE BENEFIT OF SOME NORTHEAST OROGRAPHICS. WILL HOLD ON TO THE WINTER STORM WARNINGS ALONG THE CONTINENTAL DIVIDE. THESE AREAS SHOULD PICK UP ANOTHER 5 TO 10 INCHES OVERNIGHT WITH THE HEAVIEST ACROSS SOUTHERN PORTIONS OF THE EASTERN SAN JUAN MOUNTAINS. A COUPLE OTHER CHALLENGING SPOTS INCLUDE THE SAN LUIS VALLEY WHERE HIGH RES MODELS ARE NOT SHOWING MUCH SNOW. HAVE GONE WITH AROUND AN INCH TO 1.5 ACROSS THE VALLEY FLOOR GIVEN THIS AREA WILL BE IN BETTER PROXIMITY TO THE UPPER DYNAMICS. BEST CHANCE WILL COME IN AFTER 10 PM FOR THIS AREA. BACA COUNTY IS THE FINAL CHALLENGE. MODEL RUNS WERE SUGGESTING AROUND 2 TO 4 INCHES OUT THAT WAY...JUST SHY OF ADVISORY CRITERIA...BUT LATEST NAM12 HAS COME IN HEAVIER...SO THIS AREA MAY HAVE TO BE MONITORED CLOSELY IF THE HEAVIER SNOW BAND SETS UP ACROSS THAT AREA. HIGHLIGHTS WILL PARE OFF FROM NORTH TO SOUTH TOWARDS MORNING. MOST OF THE SNOW WILL BE DONE BY 10Z UP NORTH...AND BY 13-16Z DOWN SOUTH. MOSTLY SUNNY SKIES WILL RETURN BY MID DAY SUNDAY. TEMPERATURES TONIGHT WILL DROP BACK DOWN INTO THE SINGLE DIGITS FOR MOST OF THE SOUTHEAST PLAINS WHERE THE CORE OF THE COLDER AIR WILL SPREAD IN. SOME SPOTS COULD DROP INTO THE NEGATIVE DIGITS UP NORTH IF CLEARING CAN OCCUR EARLY ENOUGH. SAN LUIS VALLEY WILL HAVE THE BENEFIT OF CLOUDS AND PRECIPITATION OVERNIGHT SO LOWS THERE MAY ONLY DROP INTO THE TEENS. KEPT HIGH TEMPERATURES ON SUNDAY CLOSER TO THE COLDER SIDE OF GUIDANCE. -KT .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 PM MST SAT NOV 15 2014 ...A SLOW WARMING TREND... A SLOW WARMING TREND TO AROUND MID NOVEMBER AVERAGES REMAINS IN THE OFFING INTO THE MIDDLE OF THE UPCOMING WORK WEEK...AS COLD NORTH TO NORTHWEST FLOW ALOFT ACROSS THE REGION SUNDAY NIGHT GIVES WAY TO WARMER MORE WESTERLY FLOW BY WEDNESDAY. TEMPERATURES TO BE THE MAIN CONCERN AND HEADACHE IN THE SHORT TERM...WITH HIGHS AND LOWS TO BE INFLUENCED BY SNOW COVER. AT ANY RATE...HAVE GONE AT OR BELOW THE COLDER SIDE OF GUIDANCE FOR SUNDAY NIGHT AND MONDAY...ESPECIALLY ACROSS THE SOUTHEASTERN MTS AND PLAINS WITH LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AND HIGHS MAINLY IN THE 20S. INDUCED LEE TROUGHING AHEAD OF A SHORT WAVE TRANSLATING ACROSS THE NORTHERN ROCKIES SHOULD KEEP LOWS SLIGHTLY WARMER ACROSS THE EASTERN SLOPES MONDAY NIGHT AND COULD BOOST HIGHS INTO THE 30S TO LOWER 40S ACROSS THE LOWER ELEVATIONS ON TUESDAY. BUILDING UPPER RIDGE ACROSS THE GREAT BASIN TUESDAY NIGHT FLATTENS ACROSS THE STATE THROUGH WEDNESDAY NIGHT AS MINOR WAVES TRANSLATE EAST ACROSS THE GREAT BASIN AND ROCKIES...WITH THE DOWNSLOPE FLOW OWNING TO THE EXPECTED WARMING TEMPERATURES AND BRINGING CHANCES OF LIGHT SNOWFALL TO THE HIGHER TERRAIN...MAINLY ALONG AND WEST OF THE CONTDVD THURSDAY AND FRIDAY. LATEST MODELS ARE SHOWING A STRONGER SYSTEM MOVING ACROSS THE GREAT BASIN FRIDAY AND ACROSS THE ROCKIES ON SATURDAY...THOUGH BOTH THE GFS AND EC HAVE SHOWN RUN TO RUN INCONSISTENCIES ON ITS TIMING AND STRENGTH. FOR NOW...HAVE KEPT ANY PRECIPITATION CHANCES CONFINED TO THE HIGHER TERRAIN FRIDAY NIGHT AND SATURDAY WITH TEMPERATURES AROUND SEASONAL AVERAGES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 330 PM MST SAT NOV 15 2014 EXPECT DETERIORATING CONDITIONS THROUGH THE EVENING WITH CIGS DROPPING INTO THE IFR CATEGORY AT KCOS AND KPUB BY 00Z AS SNOW DEVELOPS AND SPREAD OFF THE MOUNTAINS. BOTH TERMINALS COULD SEE AROUND 2 TO 2.5 INCHES OF SNOW. SNOW SHOULD DIMINISH AFTER 10Z FOR BOTH TERMINALS WITH CIGS BREAKING BY 15Z. VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY. KALS WILL SEE A LITTLE LATER START TO THE SNOW...WITH SNOW SPREADING IN AFTER 05Z...AND CONTINUING THROUGH 12Z. CIGS MAY DROP INTO THE IFR CATEGORY AT TIMES OVERNIGHT. WIDESPREAD MTN OBSCURATIONS CAN BE EXPECTED TONIGHT WHICH WILL DECREASE FROM NORTH TO SOUTH SUNDAY MORNING. MEANWHILE...GUSTY NORTH WINDS WILL CONTINUE THROUGH THE EVENING ACROSS THE PLAINS BEFORE DIMINISHING OVERNIGHT. KALS WILL SEE GUSTY WEST WINDS...SHIFTING AROUND TO THE NORTH AFTER 08-09Z AS THE SYSTEM MOVES ACROSS. WINDS ON SUNDAY WILL BE LIGHTER AT ALL THREE TAF SITES. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 9 AM MST SUNDAY FOR COZ072-073-079- 080-087-088-094. WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR COZ077-078-083- 086. WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066. WINTER STORM WARNING UNTIL 9 AM MST SUNDAY FOR COZ074-075. WINTER STORM WARNING UNTIL 9 AM MST SUNDAY FOR COZ068. && $$ SHORT TERM...KT LONG TERM...MW AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1050 AM MST SAT NOV 15 2014 .UPDATE... ISSUED AT 1003 AM MST SAT NOV 15 2014 BASED ON LATEST SAT AND MSAS SFC PRESSURE RISES...FRONT ALREADY PUSHING THROUGH EL PASO COUNTY. IRONICALLY THE MIXING HAS BROUGHT SOME WARMING WITH LOCATIONS FINALLY HITTING ABOVE FREEZING THE FREEZING MARK...BUT TEMPERATURES ARE IN THE TEENS BEHIND THE FRONT SO EXPECT ANOTHER QUICK DROP IN TEMPERATURES THROUGH THE AFTERNOON ACROSS SE CO. HIGHS HAVE ALREADY LIKELY BEEN REACHED IN EL PASO COUNTY WITH FALLING TEMPERATURES EXPECTED THROUGH THE REMAINDER OF THE DAY. MODELS CONTINUING TO STRUGGLE WITH TIMING OF PRECIPITATION AS IT IS ALREADY SNOWING UP IN NE COLORADO WHICH MODELS ARE NOT HANDLING WELL. SPED UP THE TIMING OF SNOW IN THE GRIDS. EXPECT LIGHT SNOW TO START BY LATE MORNING ACROSS MONUMENT HILL...WITH HEAVIER SNOW HOLDING OFF UNTIL 22Z ACROSS NORTHERN PORTIONS OF THE AREA...THEN RAPIDLY SPREADING SOUTHWARD THROUGH 00Z AS FORCING FROM THE UPPER TROF APPROACHES. -KT && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 412 AM MST SAT NOV 15 2014 ...MORE SNOW AND ARCTIC AIR ON THE WAY... CURRENTLY... THE LEADING EDGE OF THE NEXT ARCTIC INTRUSION WAS ALONG THE CO/WY BORDER AND IT WAS HEADING SOUTH. CLOSER TO HOME...TEMPERATURES AT 3 AM VARIED CONSIDERABLY ACROSS THE PLAINS...AS ELEVATIONS GENERALLY ABOVE 6000 FEET WERE IN THE RELATIVELY WARMER AIR (30S AND 40S) WHILE AREAS BELOW 6000 WERE IN THE TEENS AND 20S. IN THE MTNS AND VALLEYS...IT WAS RELATIVELY WARM WITH TEMPS IN THE 20S AND 30S. RADAR...OBS AND WEB CAMS INDICATED THAT SNOW STILL OCCURRING OVER THE CONTDVD. TODAY... WEATHER WILL BE QUITE ACTIVE DURING THE NEXT 24. HRRR INDICATES THAT THE LEADING EDGE OF THE ARCTIC AIR WILL MOVE INTO EL PASO COUNTY AROUND 9-10 AM AND WILL PROGRESS SOUTH...REACHING THE NEW MEXICO BORDER BY 3 PM. LIKEWISE...MAX TEMPS TODAY WILL LIKELY OCCUR THIS MORNING ACROSS THE PIKES PEAK REGION AND MIDDAY ACROSS THE REST OF THE REGION. TEMPS WILL QUICKLY FALL AFTER THE ARCTIC FRONT GOES BY. AS FOR PRECIP...IN THE MTNS...STEADY SNOW...SOME HEAVY...WILL CONTINUE ACROSS THE CENTRAL MTNS ALL DAY TODAY. SNOW ACROSS THE SAN JUANS WILL DECREASE LATER THIS MORNING BUT WILL RAMP UP ONCE AGAIN BY MID AFTERNOON. PRECIP ON THE PLAINS WILL GENERALLY DEVELOP ACROSS THE PIKES PEAK REGION SHORTLY AFTER NOON AND WILL PICK UP AS THE AFTERNOON PROGRESSES. STEADY SNOW WILL LIKELY BE ONGOING BY LATE AFTERNOON ACROSS EL PASO COUNTY AND TRAVEL WILL ONCE AGAIN BECOME DIFFICULT ACROSS THIS REGION. WINDS WILL LIKELY BE A BIT GUSTY SO AREAS OF BLOWING SNOW WILL OCCUR. BY LATE AFTERNOON THE SNOW WILL DEVELOP FARTHER SOUTH DOWN THE I-25 CORRIDOR AND EASTERN MTN REGION. OTHERWISE...THE REST OF THE PLAINS WILL LIKELY REMAIN DRY. TONIGHT... MAIN CONCERN DURING THIS PERIOD IS THE SPANISH PEAKS/RATON MESA/WET MTNS REGION AS ALL GUIDANCE IS SHOWING PRETTY HEALTHY QPF BULLSEYES OVER THIS REGION. FOR NOW I HAVE ISSUED A WINTER WEATHER ADVISORY FOR THIS REGION WITH THE AREA LIKELY RECEIVING 3-6 INCHES OF SNOW AT THE LOWER ELEVATIONS OF LAS ANIMAS AND HUERFANO COUNTIES WHILE HIGHER ELEVATIONS WILL LIKELY RECEIVE 4 TO 10 INCHES OF SNOW. IT IS POSSIBLE THAT THESE VALUES MAY BE ON THE LOW SIDE...ESPECIALLY IF GUIDANCE DOES VERIFY. WILL ALLOW LATER SHIFT TO REANALYZE AND UPGRADE TO WARNING STATUS IF LATER SIMULATIONS SHOW LARGE QPF VALUES OVER AFOREMENTIONED REGION. FOR THE REST OF THE PLAINS...EL PASO COUNTY SHOULD GENERALLY RECEIVE ABOUT 2-4" OF SNOW WITH THIS EVENT WITH 2-6 IN TELLER COUNTY AND PIKES PEAK. PUEBLO/FREMONT COUNTIES WILL LIKELY RECEIVE ANYWHERE FROM BETWEEN 2 AND 5 INCHES. OVER THE FAR EAST PLAINS...1 TO 2 INCHES WILL BE POSSIBLE. THE MOUNTAINS WILL CONTINUE TO SEE SNOW...HOWEVER THE SNOW WILL END FROM S TO N ACROSS THE C MTNS LATER TONIGHT. OVERALL ANOTHER 6 TO 12 INCHES OF SNOW IS LIKELY OVER THE CONTDVD REGION TEMPS TONIGHT WILL BE COLD ONCE AGAIN ACROSS THE ENTIRE REGION. SINGLE DIGITS WILL OCCUR ACROSS NEARLY ALL OF THE REGION EXCEPT TEENS MAINLY IN THE SAN LUIS VALLEY. /HODANISH .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 412 AM MST SAT NOV 15 2014 ...COLD SUNDAY THEN GRADUAL WARMING... SNOW WILL LINGER ALONG THE SOUTHERN BORDER AREAS EARLY SUNDAY...BUT SHOULD MOSTLY END BY NOON AS PROGRESSIVE SHORTWAVE MOVES ON THROUGH. NEW SHOT OF ARCTIC AIR WILL BRING ONE MORE REALLY COLD DAY SUNDAY BUT THEN THINGS WILL START TO WARM UP AND DRY OUT FOR MOST OF THE UPCOMING WEEK. THE WARM UP MAY START A LITTLE SLOW ON MONDAY AS SNOW COVER AND LIGHT PRESSURE GRADIENTS WILL TEND TO KEEP SURFACE INVERSIONS IN PLACE THROUGH THE DAY. BY TUESDAY...IT LOOKS LIKE WE SHOULD SEE A LITTLE BETTER MIXING AS DOWNSLOPE PRESSURE GRADIENTS DEVELOP. THIS SHOULD HELP BRING CHINOOK BREEZES OFF THE MOUNTAINS TO START WARMING THE AIR. COULD BE A LITTLE SET BACK WEDNESDAY AS THE MODELS ARE SHOWING A WEAK SURFACE HIGH DROPPING THROUGH THE PLAINS THIS DAY. THIS COULD REESTABLISH INVERSIONS IF THERE IS ENOUGH COOLING WITH THE HIGH AND IF THERE IS ANY SNOW COVER REMAINING. THURSDAY AND ESPECIALLY FRIDAY...IT LOOKS LIKE SOME WEAK ENERGY FROM THE PACIFIC WILL START MOVING BACK INTO THE REGION. THIS ENERGY COULD SPREAD SOME SNOW SHOWERS INTO THE CONTINENTAL DIVIDE THURSDAY...AND EAST TO THE REST OF THE MOUNTAINS AND PIKES PEAK REGION ON FRIDAY. THE APPROACHING ENERGY DOESN`T LOOK STRONG AT THIS POINT SO FORECAST CONFIDENCE IS LOW AT THIS TIME. TEMPERATURES WILL LIKELY REMAIN MILD THURSDAY...BUT THEN START TO COOL ON FRIDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1016 AM MST SAT NOV 15 2014 FRONT ALREADY MOVING INTO NORTHERN PUEBLO COUNTY AS OF 1745Z. EXPECT IT TO HIT THE KPUB TAF SITE WITHIN THE NEXT HOUR. WINDS BEHIND THE FRONT WILL BE FROM THE NORTHEAST AT 15-30 KTS THROUGH THE AFTERNOON. IFR STRATUS IS ALREADY BANKED UP ACROSS NORTHERN EL PASO COUNTY...AND EXPECTED TO SPREAD SOUTHWARD AND FILL IN AGAINST THE MOUNTAINS THROUGH THE AFTERNOON. TIMING OF SNOWFALL IS A CHALLENGE AS FORECAST MODELS NOT HANDLING IT WELL WHERE SNOW IS ALREADY FALLING ACROSS NORTHEAST CO. EXPECT SOME LIGHT SNOW TO BEGIN IN KCOS AROUND 22Z...AND IN KPUB BY 23Z. HEAVIER SNOW WILL COME IN AFTER 00Z AS A BAND DEVELOPS WITH THE INCOMING SYSTEM AND SPREADS SOUTHWARD. IFR TO LIFR CONDITIONS CAN BE EXPECTED OVERNIGHT. KALS WILL SEE A LATER START TO SNOW...PROBABLY AROUND 05Z...BUT SHOULD SEE IFR CONDITIONS DEVELOP OVERNIGHT WITH SNOW. ALL THREE TERMINALS SHOULD EXPECT A COUPLE INCHES...WITH HEAVIER AMOUNTS NEAR THE MOUNTAINS. RAPIDLY IMPROVING CONDITIONS WILL SET IN EARLY SUNDAY MORNING WITH ANY LINGERING VFR STRATUS CLEARED OUT BY 15Z. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 9 AM MST SUNDAY FOR COZ072>075-079-080-087-088. WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. && $$ UPDATE...KT SHORT TERM...HODANISH LONG TERM...LW AVIATION...KT
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1015 AM MST SAT NOV 15 2014 .UPDATE... ISSUED AT 954 AM MST SAT NOV 15 2014 RADAR SHOWS SNOW BANDS INCREASING WHILE CLOUD TOPS ARE ALSO COOLING ACROSS THE REGION. AIRMASS IS POTENTIALLY UNSTABLE PER 12Z GRAND JUNCTION SOUNDING AND NOSE OF FIRST UPPER LEVEL SPEED MAX IS AIDING UPPER LEVEL DIVERGENCE. CONVECTIVE SHOWERS EVIDENCED ON THE WESTERN SLOPE RADAR WHILE BANDS OF HEAVIER SNOW HAVE ALREADY MOVED ACROSS THE NORTHERN PLAINS INCLUDING FORT COLLINS WHICH PICKED UP A QUICK ONE HALF TO ONE INCH OF SNOW WHEN A BAND MOVED ACROSS. FIRST SPEED MAX WILL PASS OFF TO THE NORTH LATER THIS MORNING WHILE NEXT JET MAX WILL PLOW INTO WESTERN COLORADO LATE THIS AFTERNOON/EVENING. LIFT ASSOCIATED WITH THIS NEXT SURGE SHOULD BRING ANOTHER INCREASE IN SNOW MAINLY ALONG AND SOUTH OF THE I-70 CORRIDOR. AS A RESULT...WILL UPGRADE THE ADVISORY IN THE I-70 CORRIDOR OF THE MOUNTAINS INCLUDING SUMMIT COUNTY...ZONE 34...TO A WINTER STORM WARNING THROUGH MIDNIGHT. OTHER MAIN CHANGES WERE TO INCREASE POPS AND SNOW AMOUNTS ON THE PLAINS PER LATEST TRENDS...AND ALSO DELAY ENDING OF SNOW MAINLY FROM DENVER AND LIMON SOUTHWARD THIS EVENING AS NEXT BATCH OF LIFT SEEN IN THE Q-G FIELDS PROVIDE AT LEAST WEAK UPPER LEVEL LIFT. TEMPERATURE FORECAST ON TRACK WITH FALLING TEMPS IN ARCTIC AIRMASS THROUGH THE REST OF THE DAY AND BELOW ZERO READINGS MUCH OF THE PLAINS TONIGHT. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 450 AM MST SAT NOV 15 2014 TWO WEATHER FEATURES TO CONTEND WITH THIS MORNING. FIRST IS THE ARCTIC FRONT SLIPPING SOUTH THROUGH WELD AND WASHINGTON COUNTIES AT THE MOMENT. A PRE-FRONTAL WIND SHIFT HAS ALREADY SWEPT THROUGH THE DENVER METRO AREA...BUT THE COLDER AIR AND LOWER CLOUDS ARE OBSERVED NORTH OF THE MAIN FRONTAL BNDRY. AT PRESENT SPEED COULD SEE THE FRONT INTO THE GREATER DENVER METRO AREA WITH THE NEXT30 MINS OR SO. PRESSURE RISES BEHIND THIS FRONT NOTHING LIKE THOSE PRESENT BEHIND THE STRONGER ARCTIC FRONT LAST MONDAY. NEVERTHELESS...SHOULD SEE TEMPERATURES SLIPPING ON THE PLAINS THROUGH THE MORNING WITH GUSTY N-NELY. GOOD BET TEMPERATURES HAVE ALREADY MAXED OUT FOR TODAY ON THE PLAINS. GUIDANCE INDICATING SINGLE DIGIT TEMPERATURES BY THIS AFTERNOON. FURTHERMORE...SNOWFALL EAST OFF THE MTNS IS STILL UP IN WYOMING...BUT WITHIN NEXT FEW HOURS SHOULD SEE A BAND OF LIGHT SNOW MAKING ITS WAY SOUTHWARD ACRS THE CWA ACCORDING TO THE HRRR AND RAP. ACCUMULATION RATES SHOULD REMAIN ON THE LIGHT SIDE...GENERALLY UNDER A QUARTER INCH PER HOUR THROUGH MIDDAY. HOWEVER MODELS SHOW A BAND OF HEAVIER SNOW DEVELOPING ALONG THE I-70 CORRIDOR DURING THE MID TO LATE AFTERNOON HOURS WITH SNOWFALL RATES AROUND 1/2 TO 3/4 INCH PER HOUR. SHOULD SEE PRECIP COMING TO AN END FROM NORTH TO SOUTH DURING THE EVENING HOURS AS LIFT AND INSTABILITY SHIFT SOUTH OF THE AREA. IN THE HIGH COUNTRY...AN INFLUX OF PACIFIC MOISTURE ON THE NOSE OF A 110+ KT JET WILL RESULT IN A STEADY INFLUX OF SNOWFALL ACROSS THE HIGH COUNTRY THROUGH THE MORNING. WEST FACING ASPECTS IN BEST POSITION TO PICK UP GREATEST SNOW AMOUNTS OVER THE NEXT 18 HOURS. WINTER WEATHER ADVISORY FOR SNOW AND BLOWING SNOW NOW IN EFFECT FOR MTN ZONES. MTN VALLEYS ZONES 30 AND 32 HAVE BEEN ADDED TO THE ADVSY. 5-12 INCH ACCUMS EXPECTED IN MTN ZONES...WITH 3-7 INCH TOTALS ON THE VALLEY FLOORS. INCREASING WEST WINDS WITH ARRIVAL OF THE JET LATER THIS MORNING WILL LIKELY PRODUCE BLOWING AND DRIFTING SNOW IN OPEN AREAS IN THE HIGH COUNTRY MAKING TRAVEL DIFFICULT IF NOT HAZARDOUS FOR A TIME THIS AFTERNOON. JET...MOISTURE AND DYNAMICS ARE FORECAST TO MIGRATE SOUTH AND EAST OF THE AREA THIS EVENING PUTTING A GRADUAL END TO SNOWFALL AND WINDS STARTING IN THE NORTHERN AREAS. CLEARING SKIES LATE TONIGHT WILL RESULT IN BITTER OVERNIGHT LOWS AND POSSIBLY SOME DENSE FOG ON THE PLAINS BEFORE MORNING. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 450 AM MST SAT NOV 15 2014 THE UPPER LEVEL TROF AXIS WILL SAG SOUTHWARD OVER SOUTHERN COLORADO SUNDAY MORNING WITH DRYING AIRMASS. HOWEVER WILL STILL HAVE RATHER COLD TEMPERATURES DURING THE DAY SUNDAY WITH FRESH SNOW COVER AND LINGERING LOW LEVEL INVERSIONS. BY SUNDAY AFTERNOON AND EVENING AN UPPER LEVEL TROF SWEEPS ACROSS THE NORTHERN HIGH PLAINS WITH SOME REFLECTION AT THE SURFACE OVER FAR NORTHEAST COLORADO. STILL REMAINS A SUBSIDENT AIRMASS BUT A MID LEVEL DECK OF CLOUDS EXPECTED. WILL KEEP CONDITIONS DRY FOR NOW BUT GUSTY NORTHWEST WINDS OVER THE PLAINS. MUCH OF NEXT WEEK THROUGH WEDNESDAY WILL BE CHARACTERIZED WITH A STRONG NORTHWEST FLOW PATTERN WITH HIGH AMPLITUDE RIDGING ALONG WEST COAST AND STRONG LOW OVER GREAT LAKES REGION. THERE WILL BE A SLOW MODERATION OF TEMPERATURES WHILE GUSTY WINDS CONTINUE AT TIMES OVER THE HIGH MOUNTAINS. COULD SEE SOME GUSTS UP TO 50 MPH OVER THE MOUNTAIN PASSES. BY THURSDAY AND FRIDAY...SOME PACIFIC MOISTURE BEGINS TO STREAM INTO THE MOUNTAINS WITH A WEAK DISTURBANCE. WILL HAVE LOW POPS IN FOR NOW. FOR LOWER ELEVATIONS...GENERALLY MILD WITH READINGS IN THE 40S ALONG WITH DRY CONDITIONS. && .AVIATION...(FOR THE TAFS THROUGH 18Z SUNDAY MORNING) ISSUED AT 954 AM MST SAT NOV 15 2014 LIGHT SNOW AND IFR/MVFR CEILINGS/VSBYS OVER HAVE OVERSPREAD THE FRONT RANGE AIRPORTS THIS MORNING. THESE CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON HOURS ALTHOUGH A COUPLE HEAVIER SNOW BANDS COULD DROP VSBYS TO 1/4-1/2SM FOR A 30-45 MINUTE PERIOD. MAIN CHANGE WAS TO DELAY THE ENDING OF SNOW AS NEXT UPPER LEVEL DISTURBANCE COULD VERY WELL KEEP SNOW IN THE FORECAST TIL AROUND 06Z/07Z. LATEST SHORT RANGE RAP AND HRRR ALSO POINT TO THIS. TOTAL SNOW ACCUMULATIONS 1-3 INCHES EXPECTED. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 8 PM MST THIS EVENING FOR COZ030>033. WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR COZ034. && $$ UPDATE...BARJENBRUCH SHORT TERM...BAKER LONG TERM...ENTREKIN AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1013 AM MST SAT NOV 15 2014 .UPDATE... ISSUED AT 1003 AM MST SAT NOV 15 2014 BASED ON LATEST SAT AND MSAS SFC PRESSURE RISES...FRONT ALREADY PUSHING THROUGH EL PASO COUNTY. IRONICALLY THE MIXING HAS BROUGHT SOME WARMING WITH LOCATIONS FINALLY HITTING ABOVE FREEZING THE FREEZING MARK...BUT TEMPERATURES ARE IN THE TEENS BEHIND THE FRONT SO EXPECT ANOTHER QUICK DROP IN TEMPERATURES THROUGH THE AFTERNOON ACROSS SE CO. HIGHS HAVE ALREADY LIKELY BEEN REACHED IN EL PASO COUNTY WITH FALLING TEMPERATURES EXPECTED THROUGH THE REMAINDER OF THE DAY. MODELS CONTINUING TO STRUGGLE WITH TIMING OF PRECIPITATION AS IT IS ALREADY SNOWING UP IN NE COLORADO WHICH MODELS ARE NOT HANDLING WELL. SPED UP THE TIMING OF SNOW IN THE GRIDS. EXPECT LIGHT SNOW TO START BY LATE MORNING ACROSS MONUMENT HILL...WITH HEAVIER SNOW HOLDING OFF UNTIL 22Z ACROSS NORTHERN PORTIONS OF THE AREA...THEN RAPIDLY SPREADING SOUTHWARD THROUGH 00Z AS FORCING FROM THE UPPER TROF APPROACHES. -KT && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 412 AM MST SAT NOV 15 2014 ...MORE SNOW AND ARCTIC AIR ON THE WAY... CURRENTLY... THE LEADING EDGE OF THE NEXT ARCTIC INTRUSION WAS ALONG THE CO/WY BORDER AND IT WAS HEADING SOUTH. CLOSER TO HOME...TEMPERATURES AT 3 AM VARIED CONSIDERABLY ACROSS THE PLAINS...AS ELEVATIONS GENERALLY ABOVE 6000 FEET WERE IN THE RELATIVELY WARMER AIR (30S AND 40S) WHILE AREAS BELOW 6000 WERE IN THE TEENS AND 20S. IN THE MTNS AND VALLEYS...IT WAS RELATIVELY WARM WITH TEMPS IN THE 20S AND 30S. RADAR...OBS AND WEB CAMS INDICATED THAT SNOW STILL OCCURRING OVER THE CONTDVD. TODAY... WEATHER WILL BE QUITE ACTIVE DURING THE NEXT 24. HRRR INDICATES THAT THE LEADING EDGE OF THE ARCTIC AIR WILL MOVE INTO EL PASO COUNTY AROUND 9-10 AM AND WILL PROGRESS SOUTH...REACHING THE NEW MEXICO BORDER BY 3 PM. LIKEWISE...MAX TEMPS TODAY WILL LIKELY OCCUR THIS MORNING ACROSS THE PIKES PEAK REGION AND MIDDAY ACROSS THE REST OF THE REGION. TEMPS WILL QUICKLY FALL AFTER THE ARCTIC FRONT GOES BY. AS FOR PRECIP...IN THE MTNS...STEADY SNOW...SOME HEAVY...WILL CONTINUE ACROSS THE CENTRAL MTNS ALL DAY TODAY. SNOW ACROSS THE SAN JUANS WILL DECREASE LATER THIS MORNING BUT WILL RAMP UP ONCE AGAIN BY MID AFTERNOON. PRECIP ON THE PLAINS WILL GENERALLY DEVELOP ACROSS THE PIKES PEAK REGION SHORTLY AFTER NOON AND WILL PICK UP AS THE AFTERNOON PROGRESSES. STEADY SNOW WILL LIKELY BE ONGOING BY LATE AFTERNOON ACROSS EL PASO COUNTY AND TRAVEL WILL ONCE AGAIN BECOME DIFFICULT ACROSS THIS REGION. WINDS WILL LIKELY BE A BIT GUSTY SO AREAS OF BLOWING SNOW WILL OCCUR. BY LATE AFTERNOON THE SNOW WILL DEVELOP FARTHER SOUTH DOWN THE I-25 CORRIDOR AND EASTERN MTN REGION. OTHERWISE...THE REST OF THE PLAINS WILL LIKELY REMAIN DRY. TONIGHT... MAIN CONCERN DURING THIS PERIOD IS THE SPANISH PEAKS/RATON MESA/WET MTNS REGION AS ALL GUIDANCE IS SHOWING PRETTY HEALTHY QPF BULLSEYES OVER THIS REGION. FOR NOW I HAVE ISSUED A WINTER WEATHER ADVISORY FOR THIS REGION WITH THE AREA LIKELY RECEIVING 3-6 INCHES OF SNOW AT THE LOWER ELEVATIONS OF LAS ANIMAS AND HUERFANO COUNTIES WHILE HIGHER ELEVATIONS WILL LIKELY RECEIVE 4 TO 10 INCHES OF SNOW. IT IS POSSIBLE THAT THESE VALUES MAY BE ON THE LOW SIDE...ESPECIALLY IF GUIDANCE DOES VERIFY. WILL ALLOW LATER SHIFT TO REANALYZE AND UPGRADE TO WARNING STATUS IF LATER SIMULATIONS SHOW LARGE QPF VALUES OVER AFOREMENTIONED REGION. FOR THE REST OF THE PLAINS...EL PASO COUNTY SHOULD GENERALLY RECEIVE ABOUT 2-4" OF SNOW WITH THIS EVENT WITH 2-6 IN TELLER COUNTY AND PIKES PEAK. PUEBLO/FREMONT COUNTIES WILL LIKELY RECEIVE ANYWHERE FROM BETWEEN 2 AND 5 INCHES. OVER THE FAR EAST PLAINS...1 TO 2 INCHES WILL BE POSSIBLE. THE MOUNTAINS WILL CONTINUE TO SEE SNOW...HOWEVER THE SNOW WILL END FROM S TO N ACROSS THE C MTNS LATER TONIGHT. OVERALL ANOTHER 6 TO 12 INCHES OF SNOW IS LIKELY OVER THE CONTDVD REGION TEMPS TONIGHT WILL BE COLD ONCE AGAIN ACROSS THE ENTIRE REGION. SINGLE DIGITS WILL OCCUR ACROSS NEARLY ALL OF THE REGION EXCEPT TEENS MAINLY IN THE SAN LUIS VALLEY. /HODANISH .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 412 AM MST SAT NOV 15 2014 ...COLD SUNDAY THEN GRADUAL WARMING... SNOW WILL LINGER ALONG THE SOUTHERN BORDER AREAS EARLY SUNDAY...BUT SHOULD MOSTLY END BY NOON AS PROGRESSIVE SHORTWAVE MOVES ON THROUGH. NEW SHOT OF ARCTIC AIR WILL BRING ONE MORE REALLY COLD DAY SUNDAY BUT THEN THINGS WILL START TO WARM UP AND DRY OUT FOR MOST OF THE UPCOMING WEEK. THE WARM UP MAY START A LITTLE SLOW ON MONDAY AS SNOW COVER AND LIGHT PRESSURE GRADIENTS WILL TEND TO KEEP SURFACE INVERSIONS IN PLACE THROUGH THE DAY. BY TUESDAY...IT LOOKS LIKE WE SHOULD SEE A LITTLE BETTER MIXING AS DOWNSLOPE PRESSURE GRADIENTS DEVELOP. THIS SHOULD HELP BRING CHINOOK BREEZES OFF THE MOUNTAINS TO START WARMING THE AIR. COULD BE A LITTLE SET BACK WEDNESDAY AS THE MODELS ARE SHOWING A WEAK SURFACE HIGH DROPPING THROUGH THE PLAINS THIS DAY. THIS COULD REESTABLISH INVERSIONS IF THERE IS ENOUGH COOLING WITH THE HIGH AND IF THERE IS ANY SNOW COVER REMAINING. THURSDAY AND ESPECIALLY FRIDAY...IT LOOKS LIKE SOME WEAK ENERGY FROM THE PACIFIC WILL START MOVING BACK INTO THE REGION. THIS ENERGY COULD SPREAD SOME SNOW SHOWERS INTO THE CONTINENTAL DIVIDE THURSDAY...AND EAST TO THE REST OF THE MOUNTAINS AND PIKES PEAK REGION ON FRIDAY. THE APPROACHING ENERGY DOESN`T LOOK STRONG AT THIS POINT SO FORECAST CONFIDENCE IS LOW AT THIS TIME. TEMPERATURES WILL LIKELY REMAIN MILD THURSDAY...BUT THEN START TO COOL ON FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 412 AM MST SAT NOV 15 2014 KCOS...ARCTIC FRONT WILL CROSS KCOS AOA NOONTIME...18-19Z. WINDS WILL SHIFT TO NORTH THAN NORTH-NORTHEAST AND BECOME GUSTY. COULD SEE SOME SNOW SHOWERS BY MID AFTERNOON BUT EXPECT BRUNT OF IT WILL OCCUR MORE TOWARDS SUNSET. LIFR CONDITIONS WILL BE POSSIBLE/LIKELY BETWEEN 00Z-09Z AS STEADY SNOW IS EXPECTED. KPUB...ARCTIC FRONT WILL CROSS KPUB AOA 19-20Z WITH WINDS QUICKLY SHIFTING TO THE NORTHEAST AND THEN EAST. PRECIP WILL LIKELY DEVELOP AFTER SUNSET AND THERE IS A HIGH PROBABILITY THAT IT WILL SNOW...AND IT IS EXPECTED TO ACCUMULATE TO 2-4 INCHES. LIFR CONDITIONS LIKELY ONCE SNOW STARTS. IT WILL LAST THROUGH THE NIGHT ENDING AROUND SUNRISE. KALS...LOW CIGS THIS MORNING SHOULD BREAK UP ABOUT 1-2HRS AFTER SUNRISE AS WEST WINDS INCREASE. VFR EXPECTED THROUGH THE REST OF THE DAY WITH PRECIP DEVELOPING AFTER MIDNIGHT. SNOW WILL LIKELY ACCUMULATE AT KALS WITH 1-2" ANTICIPATED. CIGS LIKELY WILL GO LIFR AFTER MIDNIGHT. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 9 AM MST SUNDAY FOR COZ072>075-079-080-087-088. WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066- 068. && $$ UPDATE...KT SHORT TERM...HODANISH LONG TERM...LW AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1208 PM CST SAT NOV 15 2014 .UPDATE... ISSUED AT 1207 PM CST SAT NOV 15 2014 SNOW CONTINUES TO EXPAND ACROSS CENTRAL IOWA. THE EARLY MORNING ACTIVITY BROUGHT AROUND 3 INCHES OVER THE FAR NORTHWEST. THE HEAVIES SNOWFALL RATES WILL SHIFT INTO CENTRAL IOWA THIS AFTERNOON NEAR THE STRONGEST MID LEVEL FRONTOGENESIS. GRADUALLY COOLING PROFILES WILL LEAD TO A DEEP DENDRITIC LAYER FROM NEAR 900 MB TO 500 MB. THESE TYPE EVENTS TEND TO BE EFFICIENT SNOW DEPTH PRODUCING EVENTS WITH A PROLONGED PERIOD OF DENDRITES LEADING TO HIGH SNOW RATIOS NEAR 20 TO 1. SNOW INTENSITIES WILL DIMINISH FOR A PERIOD LATE AFTERNOON INTO THE EARLY EVENING. A VIGOROUS UPPER LEVEL SHORT WAVE OVER WYOMING WITH KINEMATIC FORCING MOVING AHEAD THROUGH CENTRAL SOUTH DAKOTA AND NORTHWEST NEBRASKA. THIS ENERGY WILL ARRIVE THIS EVENING AND BRING A RENEWED BAND OF SNOW AND ADDITIONAL ACCUMULATIONS. A WIDESPREAD 2 TO 4 INCHES STILL IS EXPECTED WITH A FEW LOCATIONS APPROACHING 6 INCHES OVER THE NORTHWEST. && .SHORT TERM /TODAY/... ISSUED AT 303 AM CST SAT NOV 15 2014 NO MAJOR CHANGES WITH ONGOING FORECAST FOR THE FIRST SIGNIFICANT SNOWFALL OF THE SEASON AS MODELS REMAIN IN GOOD AGREEMENT WITH EXPECTED SNOW TODAY. USED A BLEND OF THE HRRR/HOPWRF FOR TIMING OF PRECIP AND NAM/ECMWF TEMPS. BROAD ISENTROPIC LIFT AND DECENT MOISTURE TRANSPORT DEVELOP OVER WESTERN TO NORTHWEST IOWA THIS MORNING AND QUICKLY BLOSSOMS ACROSS THE REMAINDER OF THE STATE THIS AFTERNOON. ONE MINOR CHANGE WAS START THE SNOW A LITTLE SOONER THIS MORNING OVER THE WEST TO NORTHWEST AS SNOW ALREADY DEVELOPING ALOFT AND SNOW SHOULD START REACHING THE SURFACE BETWEEN 12-14Z THIS MORNING. THE 15.03Z HOPWRF AND 15.05Z HRRR HAVE SNOW MOVING INTO THE WESTERN EDGES OF THE FORECAST AREA BETWEEN 13-15Z. THE FORECAST SOUNDINGS ACROSS NORTHERN IOWA BECOME COMPLETELY SATURATED BY 17-18Z TODAY AND THE STRONGER OMEGA IS JUST AT THE TOP EDGE OF THE DENDRITIC LAYER BUT ENOUGH OVERLAP TO SEE SOME DECENT FLAKES...AND THUS SLIGHTLY HIGHER SNOW ACCUMULATION THIS AFTERNOON OVER NORTHERN IOWA. RAP IS A BIT LESS WITH THE FORCING THAN THE NAM/GFS AND HAS SLIGHTLY LOWER SNOW AMOUNTS GOING...BUT STILL DEPICTS ENOUGH SNOW TO WARRANT ADVISORY. FURTHER SOUTH...SOUNDINGS NOT TOO DISSIMILAR THAN NORTHERN IOWA...WITH THE MAIN DIFFERENCE BEING JUST SLIGHTLY LESSER FORCING WITHIN THE DENDRITIC LAYER. THIS RESULTING IN LESS SNOW AMOUNTS OVER THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA. LEANED TOWARD A BLEND OF THE WARMER NAM/ECMWF FOR TEMPERATURES TODAY. THIS RESULTED IN SNOW RATIOS AROUND 17:1 TO 18:1 OVER NORTHERN IOWA AND 15:1 TO 16:1 ACROSS THE SOUTH...BASED ON 925M TO 700MB THICKNESS. HAVE 100 POPS GOING MUCH OF THE AFTERNOON WITH HIGH CONFIDENCE ALL OF CENTRAL IOWA WILL BE SNOWING BY OR SHORTLY PAST 18Z. VERY LITTLE WIND TODAY BUT WITH THE FLUFFY SNOW TYPE EXPECTED AND AT TIMES FALLING MODERATELY...THIS SHOULD BE ENOUGH TO CAUSE SOME VISIBILITY RESTRICTION WITH A 6-9 KNOT WIND. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 303 AM CST SAT NOV 15 2014 ACTIVE WEATHER WILL CONTINUE THROUGH THE WEEKEND AND EARLY NEXT WEEK FOLLOWING TONIGHTS SYSTEM...ANOTHER INTENSE UPPER LEVEL LOW WILL DROP SOUTH INTO THE NORTHERN GREAT LAKES SUNDAY NIGHT AND MONDAY MORNING. TONIGHT...SYSTEM EXITING THE AREA TO THE EAST DURING THE EVENING HOURS. BEST FORCING ALONG H500 AND SFC TROUGH NEAR 00Z FOCUSING ON H700 BOUNDARY ACROSS NORTHERN IOWA. THROUGH 06Z THIS H700 BOUNDARY PUSHES EAST WITH TROUGH RESULTING IN LESSENING FORCING WEST OF I35 DURING THE LATE EVENING. BY 12Z BEST FORCING EAST OF THE AREA WITH SOME RESIDUAL LIGHT SNOW/FLURRIES OVER THE NORTHEAST ENDING QUICKLY WITH CLOUDS DEPARTING IN THE MORNING SUNDAY. SNOW RATIOS OF 18 TO 20:1 AND EXPECTED QPF AMOUNT YIELD SNOWFALL AMOUNTS OF UP TO ANOTHER 1.5 INCHES TONIGHT DURING THE EVENING AND OVERNIGHT HOURS. FORTUNATELY THE WINDS WILL BE LIGHT DURING THE EVENT...SO BLOWING SNOW WILL NOT BE AN ISSUE TONIGHT. WITH CLEARING BY MORNING...LOWS WILL QUICKLY FALL NORTHWEST AND WEST INTO THE SINGLE DIGITS WITH TEENS I35 EAST. SUNDAY WILL INITIALLY SEE SOME SUNSHINE BETWEEN WAVES BUT CLOUDS WILL INCREASE WEST DURING THE AFTERNOON. WITH H850 TEMPS IN THE -10C TO -12C RANGE AND WESTERLY WINDS...TEMPERATURES WILL BE TOLERABLE IN THE MID 20S OVER MOST OF THE AREA. AN APPROACHING COLD FRONT WILL SPREAD CLOUDS ACROSS THE REGION THROUGH EARLY EVENING. THE SECOND STRONG H500 LOW WILL FORCE A BULGE OF COLD AIR QUICKLY SOUTHEAST INTO WESTERN IOWA SUNDAY EVENING WITH RATHER STRONG COLD AIR ADVECTION AND INCREASING WINDS ALOFT. BY 12Z H850 TEMPS WILL HAVE FALLEN ANOTHER 8 TO 10C WITH READINGS FROM -16C TO -20C. THROUGH THE DAY MONDAY CLOUD COVER WILL OVERTAKE THE AREA WITH H850 TEMPS SETTLING TOWARD -18C TO -20C REGION WIDE. MODELS HAVE BEEN CONSISTENT WITH STEEPENING LAPSE RATES NEAR 15Z AND STRONG MIXING THROUGH THE DAY...POTENTIAL FOR SNOW SHOWERS ACROSS THE NORTHEAST WITH FLURRIES CENTRAL AND SOUTH. ALL IN ALL...MONDAY IS LOOKING RATHER UNPLEASANT. POTENTIAL FOR 15 TO 25 MPH WINDS WITH GUSTS TO NEAR 35 MPH AT TIMES. THIS WILL CAUSE PATCHY TO AREAS BLOWING SNOW OVER MUCH OF THE NORTHEAST HALF OF THE AREA WITH REDUCTIONS TO VISIBILITY. HEADLINES MAY BE NEEDED AGAIN ON MONDAY FOR THE COMBINATION OF WIND...BLOWING SNOW...AND COLD. HAVE EXPANDED THE POTENTIAL FOR LIGHT PRECIP AND BLOWING SNOW MONDAY ACROSS THE AREA. HIGHS WILL RECOVER LITTLE FROM FRIGID MORNING LOWS IN THE SINGLE DIGITS TO LOWER TEENS. BY AFTERNOON HIGHS NORTH WILL REACH THE LOWER TEENS TO THE LOWER 20S IN THE SOUTHEAST. TO TOP OFF THE WONDERFUL DAY...MINIMUM RECORD HIGHS LOOK LIKELY TO BE SET AT MANY LOCATIONS...ONE WHICH HAS NOT BEEN SEEN SINCE THE 1890S AND MANY SINCE THE 1950S. IN FACT...OUR HIGHS MONDAY WOULD STILL BE ABOUT 10 TO 15 DEGREES BELOW OUR COLDEST AVERAGE HIGHS FOR THE NORMALLY COLDEST WINTER DAY OF THE YEAR...OR ABOUT 30 DEGREES BELOW OUR NORMAL FOR 11/17. WE HAVENT HAD HIGHS THIS COLD SINCE EARLY MARCH OF 2014. TUESDAY WILL BEGIN QUITE COLD WITH A RIDGE JUST EDGING INTO THE AREA BUT WARM BY AFTERNOON. QUICKLY ANOTHER CLIPPER OVER THE NORTHERN PLAINS WILL MODERATE THE AIRMASS WITH BRISK WEST WINDS DEVELOPING DURING THE DAY. TEMPS WILL RISE INTO THE 20S. ANOTHER ARCTIC FRONT WILL DROP SOUTH INTO THE AREA TUESDAY NIGHT BUT THE AIRMASS WILL NOT BE QUITE AS COLD AS THE PREVIOUS. THE REMAINDER OF THE WEEK FEATURES A SERIES OF ARCTIC SHORT WAVES ROTATING AROUND THE HUDSON BAY PARENT H500 LOW...PULLING ADDITIONAL COLD AIR TOWARD THE GREAT PLAINS. NEXT WEEK WILL FEATURE DAYS WITH CLOUD COVER MIXED WITH SOME SUNSHINE AND CHILLY READINGS. FORTUNATELY BY LATE IN THE EXTENDED...TOWARD SATURDAY THE CROSS POLAR FLOW CUTS OFF...THE H500 RIDGE ACROSS THE WEST COAST BREAKS DOWN AND MORE ZONAL FLOW RESULTS OVER THE ROCKIES. THIS WILL CAUSE CHINOOKS COMPRESSIONAL HEATING OVER THE PLAINS AND MODERATE HIGHS TO ABOVE FREEZING. FROM WEDNESDAY THROUGH FRIDAY HIGHS WILL APPROACH THE 30 DEGREE MARK WITH LOWS MODERATING INTO THE TEENS OVER THE AREA. LITTLE PRECIPITATION IS EXPECTED FOR MUCH OF THE PERIOD NEXT WEEK. && .AVIATION...15/18Z ISSUED AT 1147 AM CST SAT NOV 15 2014 CONDITIONS WILL CONTINUE TO DETERIORATE ACROSS SITES THIS AFTERNOON AS LOWER CIGS AND SNOW MOVE INTO THE AREA. A PERIOD OF IMPROVED VSBYS EXPECTED BY LATE AFTERNOON THROUGH EARLY EVENING BEFORE ANOTHER BAND OF SNOW ARRIVES. CIGS WILL RANGE FROM IFR TO MVFR THROUGH MUCH OF THE PERIOD. SOUTHEAST WINDS WILL BECOME WEST/NORTHWEST LATE TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ADAIR- ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN- CARROLL-CASS-CERRO GORDO-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR- EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HANCOCK-HARDIN- HUMBOLDT-JASPER-KOSSUTH-LUCAS-MADISON-MAHASKA-MARION-MARSHALL- MONROE-PALO ALTO-POCAHONTAS-POLK-POWESHIEK-RINGGOLD-SAC-STORY- TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE-WEBSTER-WINNEBAGO-WORTH- WRIGHT. && $$ UPDATE...DONAVON SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
210 PM MST SAT NOV 15 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 210 PM MST SAT NOV 15 2014 THE UPPER TROUGH AXIS MOVES SOUTH ACROSS THE CENTRAL PLAINS TONIGHT AND SUNDAY WITH NORTHWEST FLOW FOLLOWING. SURFACE HIGH PRESSURE WILL BUILD SOUTHEAST INTO THE CENTRAL PLAINS THROUGH THIS TIME. PLAN TO GO WITH CHANCE AND LIKELY POPS TONIGHT ACROSS THE FA AS DYNAMICS AND MOISTURE MOVE FROM NORTH TO SOUTH. THE DYNAMICS MOVE INTO THE SOUTHWEST PORTION OF THE FA AFTER 06Z AND SO WILL SHIFT LIKELY POPS OVER THE EXTREME SOUTHWEST AFTER MIDNIGHT WITH DECREASING POPS TO THE NORTH. MOISTURE IS LIMITED WITH THIS SYSTEM SO WILL KEEP SNOW AMOUNTS ON THE LIGHT SIDE OR A FEW TENTHS OF AN INCH. THE SOUTHWEST WILL HAVE THE BEST CHANCE OF ACCUMULATING SNOW WITH AROUND A HALF INCH POSSIBLE THERE. MIN TEMPERATURES WILL FALL INTO THE SINGLE DIGITS OVERNIGHT AND WITH NORTHWEST WIND SOME VERY COLD WIND CHILL TEMPERATURES WILL BE REACHED. WIND CHILL TEMPERATURES DROP BELOW WIND CHILL ADVISORY CRITERIA TONIGHT AND SUNDAY MORNING ACROSS THE NORTH AND WEST ZONES. PLAN TO ISSUE A WIND CHILL ADVISORY TO COVER THIS. SEE DETAILS BELOW. MAX TEMPERATURES SUNDAY SHOULD RISE TO THE UPPER 20S WITH TEMPERATURES NEAR 30 OVER THE SOUTHEAST ZONES. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 210 PM MST SAT NOV 15 2014 SEVERAL DRY DAYS ARE EXPECTED FOR THE ENTIRE FORECAST AREA GOING INTO THE BEGINNING OF NEXT WEEK. THE TRI STATE REGION WILL BE IN BETWEEN A BROAD/DEEP 500 MB TROUGH THAT SETS UP OVER THE EASTERN PORTION OF THE COUNTRY SUNDAY NIGHT INTO MONDAY...AND A BUILDING H5 RIDGE OVER THE WESTERN HALF OF THE COUNTRY. RIDGE DOES SHIFT EASTWARD INTO THE ROCKIES BY MIDWEEK..WITH 500/700 MB TROUGH COMING OFF THE PACIFIC AND THRU RIDGE...INTO ROCKIES LATE FRIDAY INTO SATURDAY. DOWN TO THE SURFACE...HIGH PRESSURE WILL BE MOST PREVALENT DURING THIS TIMEFRAME. ONLY CHANCE FOR PRECIPITATION BEFORE NEXT WEEKEND WILL BE ON WEDNESDAY AS FRONTAL BOUNDARY/TROUGH SHIFTS OFF THE ROCKIES AND EASTWARD TO THE MISSISSIPPI VALLEY. WITH HIGH PRESSURE SE OF THE AREA DURING THIS TIME AND BROAD WNW FLOW...LITTLE QPF POTENTIAL...SO WILL HAVE DRY. THE NEXT CHANCE FOR PRECIPITATION WILL BE AT THE END OF NEXT WEEK WHEN MID LEVEL SHORTWAVE MOVES EAST OFF THE PACIFIC. DRY AIR OUT AHEAD OF IT...COMBINED WITH ITS TRIP THRU THE ROCKIES...WILL LIMIT QPF POTENTIAL BUT OUTSIDE CHANCE OF A FEW LATE DAY SHOWERS. WITH LACK OF ANY APPRECIABLE RAIN OR SNOW NEXT WEEK...THE MAIN FOCUS WILL BE SHIFT IN TEMPERATURES. WITH 850/925 MB TEMPS RANGING FROM -2C TO -4C ON MONDAY...UP TO +9C TO +12C ON FRIDAY INTO SATURDAY...THE FORECAST AREA WILL SEE BELOW NORMAL TEMPS SHIFTING TO ABOVE NORMAL READINGS ESPECIALLY DURING THE DAY. TRI STATE REGION WILL SEE HIGHS NEAR 30F ON MONDAY TO MID 40S BY MIDWEEK TO ALMOST MID 50S FOR THE END OF NEXT WEEK. THIS WOULD GIVE WEDNESDAY INTO SATURDAY WITH HIGHS 5 TO 10 DEGREES ABOVE NORMAL. WITH HIGH PRESSURE MOST PREVALENT...CLEAR SKIES AT NIGHT WILL HAVE OVERNIGHT LOWS RANGING FROM THE TEENS TO START THE WEEK...TO THE 20S FOR THE REST OF THE TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1030 AM MST SAT NOV 15 2014 CIGS ARE PROGRESSIVELY LOWERING AT KGLD AND CONTINUE MVFR AT KMCK AT MIDDAY AS THE UPPER TROUGH MOVES INTO THE NORTHERN AND CENTRAL PLAINS TODAY. THE SREF AND HRRR BRING A SWATH OF LIGHT SNOW INTO THE ARE THIS AFTERNOON WHICH SHOULD IMPACT BOTH TERMINALS WITH MVFR CONDITIONS. LIGHT SNOW SHOULD END AT BOTH SITES EARLY THIS EVENING WITH VFR CONDITIONS OCCURING BEHIND THE COLD FRONT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND CHILL ADVISORY FROM 9 PM MST /10 PM CST/ THIS EVENING TO 9 AM MST /10 AM CST/ SUNDAY FOR KSZ001>003-013. CO...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 9 AM MST SUNDAY FOR COZ090-091. NE...WIND CHILL ADVISORY FROM 9 PM MST /10 PM CST/ THIS EVENING TO 9 AM MST /10 AM CST/ SUNDAY FOR NEZ079>081. && $$ SHORT TERM...FS LONG TERM...JN AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1035 AM MST SAT NOV 15 2014 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 404 AM MST SAT NOV 15 2014 MAIN FORECAST CONCERN WILL BE WINTER WEATHER EVENT OCCURRING THROUGH TONIGHT. SATELLITE CONTINUING TO SHOW AN AMPLIFIED PATTERN FROM THE EASTERN PACIFIC INTO EASTERN NORTH AMERICA. CURRENTLY NEARLY ZONAL FLOW OVER OUR AREA WITH MULTIPLE SMALL SCALE WAVES EMBEDDED WITHIN THAT FLOW. STRONG...COLD AND RATHER COMPLEX UPPER TROUGH IS MOVING THROUGH THE NORTH CENTRAL OF THE COUNTRY. SATELLITE ALSO SHOWING DRY MID LEVEL AIR MASS IN PLACE AHEAD OF INCOMING NORTHERN TROUGH. ANOTHER STRONG COLD FRONT IS APPROACHING FROM THE NORTH. AT JET LEVEL...MODELS LOOKED LIKE THEY INITIALIZED FINE. AT MID LEVELS...THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF AND CANADIAN. THE SREF WAS DOING THE BEST AT THE SURFACE. ALL THE MODELS WERE OKAY ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...THE DAY STARTS OUT WITH AREA IN SUBSIDENCE FROM DEPARTING JET. AFTER THIS MODELS DISAGREE WHERE THE MAIN JET ENERGY WILL BE THROUGH THE REST OF THE PERIOD. BY 18Z IT LOOKS LIKE A LEFT FRONT QUADRANT WILL BEGIN AFFECTING THE AREA. BY LATE IN THE AFTERNOON INTO THE EVENING...THERE MAY BE A RIGHT REAR QUADRANT ACROSS THE SOUTHEASTERN PORTION OF THE AREA. AFTER THAT THE JET IS WELL SOUTH. CURRENTLY INITIAL SHORTWAVE TROUGH IS MOVING THROUGH AND PRODUCING LIGHT SNOW OVER SOUTHERN AND EASTERN SECTIONS. MODELS HAVE A GOOD HANDLE ON THIS INITIAL SHORTWAVE TROUGH. CURRENT RADAR SHOWS THAT THE MOST INTENSE SNOWFALL IS TO THE SOUTH OF AREA AND MOVING THROUGH RATHER QUICKLY. ALL NIGHT THE HRRR HAS BEEN CATCHING THE CURRENT RADAR TRENDS EXTREMELY WELL AND IT ALSO MATCHES UP WELL WITH THE ABOVE MENTIONED MID AND UPPER LEVEL LIFT. OTHER OUTPUT IS TOO FAR NORTH WITH THE PRECIPITATION SHIELD. SO WILL LEAN HEAVILY ON THE HRRR FOR PRECIPITATION EARLY ON AND THEN TREND MORE TOWARD THE CANADIAN/ECMWF AFTER THAT. SO LITTLE TO NO SNOW FALL WILL END UP FALLING OVER THE WESTERN HALF TO TWO THIRDS THIS MORNING WITH MOST OF THE SNOW OCCURRING IN THE EASTERN SIX COUNTIES THROUGH MID MORNING. UPSTREAM SATELLITE IS SHOWING A CLEARING TREND BEHIND THIS EXITING SHORTWAVE AND A DRY AIR MASS IN ADVANCE OF THE NEXT SHORTWAVE TROUGH. AFTER THE SNOW ENDS THIS MORNING...THE NEXT BATCH OF LIGHT SNOW WILL DEVELOP TO OUR NORTH AND NORTHWEST BY LATE IN THE MORNING TO EARLY AFTERNOON. THIS AREA THEN MOVES ACROSS THE AREA THROUGH THE REST OF THE NIGHT WITH THE MOST SNOWFALL OCCURRING BEFORE MIDNIGHT. IT IS POSSIBLE THAT SOME LOCATIONS MAY NOT SEE ANY SNOW UNTIL LATER THIS AFTERNOON TO EARLY THIS EVENING. MODELS...ESPECIALLY THE GFS...TEND TO BE TOO DEEP WITH THE MOISTURE AND THEREFORE OVERPRODUCES PRECIPITATION. THE DRIER AIR MASS UPSTREAM MAKES SENSE SINCE MOISTURE IN THE WESTERLY FLOW ALOFT IS GETTING WRUNG BY THE HIGHER TERRAIN OVER COLORADO. SO PER THE REASONING GIVEN ABOVE...SNOWFALL AMOUNTS WILL BE MUCH LIGHTER THAN PREVIOUSLY EXPECTED WITH TOTAL AMOUNTS NOW ANTICIPATED TO BE AROUND AN INCH OR LESS. IT IS ALSO POSSIBLE THAT WHEN THE COLD FRONT MOVES THROUGH LATER TODAY...THAT LITTLE IF ANY SNOW WILL BE ON THE GROUND. ALSO CONSIDERING WHAT LITTLE SNOW HAS ALREADY FALLEN AND THAT THERE WILL BE A SIGNIFICANT LULL BEFORE THE NEXT SNOWFALL STARTS...HAVE DECIDED TO CANCEL THE WINTER WEATHER ADVISORY. IF SNOWFALL ENDS UP BEING WORSE THAN CURRENTLY EXPECTED...THEN A MORE SHORT TERM ADVISORY CAN BE ISSUED TO HANDLE THAT SINCE NOTHING IS GOING ON AT THIS TIME. NOW FOR TEMPERATURES. JUST LIKE LAST NIGHT...MODELS ARE TOO COOL WITH THE CURRENT TEMPERATURES DUE TO CLOUD COVER AND CONTINUED WARM AIR ADVECTION. FRONT IS ALSO EXPECTED TO ARRIVE LATER AND WILL NOT MOVE THROUGH THE EASTERN PORTION OF THE AREA UNTIL THIS AFTERNOON. THERE ALSO MAY BE ENOUGH BREAKS IN THE CLOUD COVER TO ALLOW SOME SUNSHINE TO OCCUR. A LOT OF THE OUTPUT IS SAYING WARMER AND TRENDED IN THAT DIRECTION. SUNDAY/SUNDAY NIGHT...DRY CONDITIONS EXPECTED THROUGH THE PERIOD. SHOULD SEE A DECENT AMOUNT OF SUN WITH WINDS BEING MOSTLY FROM A DOWNSLOPE DIRECTION. MODELS ARE SHOW TEMPERATURES WARMER THAN YESTERDAY. MODELS HAVE HAD A RECENT COOL BIAS AS WELL. SO WENT NEAR THE WARMER GUIDANCE. MONDAY/MONDAY NIGHT...STRONG UPPER SYSTEM DIGS INTO THE NORTH CENTRAL PORTION OF THE COUNTRY JUST BEFORE AND DURING THIS PERIOD. THIS PUSHES ANOTHER COLD FRONT THROUGH THE AREA AND SHOULD MAKE FOR COOLER TEMPERATURES COMPARED TO SUNDAY MAXES. HOWEVER...THERE IS A BIG DIFFERENCE IN THE AMOUNT OF COOLING INDICATED BY THE MODELS. DID NOT GO WITH THE COLDEST GUIDANCE BUT TRENDED IN THE COLDER DIRECTION. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 404 AM MST SAT NOV 15 2014 COMPARING TONIGHTS MODELS RUN TO LAST NIGHTS THE LONG WAVE RIDGE OVER THE WEST COAST OF THE UNITED STATES WILL STILL MOVE EAST AND BE LOCATED OVER THE ROCKIES BY FRIDAY. HOWEVER... UNLIKE LAST NIGHTS RUN... WHERE THE RIDGE LOOKED LIKE IT WOULD FLATTEN... IT NOW SEEMS IT WILL MAINTAIN ITS AMPLITUDE. THIS WILL PRODUCE A PREDOMINATELY NORTHWESTERN UPPER LEVEL FLOW OVER THE TRI-STATE AREA DURING THE EXTENDED. YESTERDAYS QUESTION WAS WHEN WILL THE NEXT FRONT PASS OVER THE AREA. TONIGHTS RUN OF THE GFS... NAVGEM AND ECMWF ARE IN BETTER AGREEMENT ON THIS FRONT COMPARED TO LAST NIGHTS RUN. THEY ALL HAVE THE FRONT PASSING OVER THE AREA ON THE 19TH BETWEEN 00Z AND 06Z. THEY ALSO SHOW THIS SYSTEM TO BE A DRY ONE AND WILL HAVE LITTLE TO NO EFFECT ON THE TEMPERATURES. IT DOES SHOW A SHIFT IN THE WINDS FOLLOWED BY LIGHT WINDS AS HIGH PRESSURE BUILDS IN BEHIND IT FOR THE REST OF THE EXTENDED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1030 AM MST SAT NOV 15 2014 CIGS ARE PROGRESSIVELY LOWERING AT KGLD AND CONTINUE MVFR AT KMCK AT MIDDAY AS THE UPPER TROUGH MOVES INTO THE NORTHERN AND CENTRAL PLAINS TODAY. THE SREF AND HRRR BRING A SWATH OF LIGHT SNOW INTO THE ARE THIS AFTERNOON WHICH SHOULD IMPACT BOTH TERMINALS WITH MVFR CONDITIONS. LIGHT SNOW SHOULD END AT BOTH SITES EARLY THIS EVENING WITH VFR CONDITIONS OCCURING BEHIND THE COLD FRONT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...BDW/BULLER AVIATION...FS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
259 PM EST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 416 AM EST SAT NOV 15 2014 A QUIET START TO THE SHORT TERM FORECAST THIS MORNING...AS THE AREA IS ON THE NORTHEAST EDGE OF A HIGH CENTERED FROM THE MID/UPPER MISSISSIPPI VALLEY TO THE OHIO RIVER VALLEY. THIS HAS LED TO A CLEAR AND COLD NIGHT ACROSS AT LEAST HALF OF THE CWA. WHERE WINDS HAVE DECOUPLED (GENERALLY ACROSS THE INTERIOR WEST AND NEAR THE WISCONSIN BORDER)...TEMPERATURES HAVE FALLEN INTO THE SINGLE DIGITS BELOW ZERO. MEANWHILE...OVER THE CENTRAL AND EAST WHERE THE WINDS HAVE BEEN STAYING UP...TEMPERATURES HAVE BEEN IN THE UPPER SINGLE DIGITS ABOVE ZERO TO MID TEENS. OVER LAKE SUPERIOR AND THE KEWEENAW...COLD AIR CONTINUING TO FLOW OVER THE RELATIVELY WARM WATERS OF LAKE SUPERIOR WAS PRODUCING MAINLY LAKE EFFECT CLOUDS THIS PAST EVENING AND INTO THE EARLY OVERNIGHT HOURS. BUT STARTED SEEING WEAK LAKE EFFECT BANDS OVER EASTERN LAKE SUPERIOR ON THE CANADIAN RADAR AT MONTREAL RIVER SHORTLY AFTER MIDNIGHT. INVERSION IS RIGHT AT 875-850MB ON 00Z KGRB/KINL SOUNDINGS AND THE LIMITED MOISTURE ON THE NORTH EDGE OF THE HIGH HAVE BEEN THE MAIN LIMITING FACTORS TO LAKE EFFECT SNOW EARLY THIS MORNING. KMQT VWP HAS BEEN SHOWING THE WINDS A LITTLE MORE OUT OF THE WEST-NORTHWEST AND CONTRIBUTING TO THE LAKE EFFECT CLOUDS NOSING SOUTHEAST INTO BARAGA...SOUTHERN HOUGHTON...AND EVEN FAR NORTHERN IRON COUNTY EARLY THIS MORNING. BUT AS WE HEAD INTO THE MORNING HOURS...MODELS SHOWING THE WINDS GOING BACK TO A MORE WESTERLY AND POTENTIALLY WEST-SOUTHWESTERLY DIRECTION AND CONFINING THE LAKE EFFECT CLOUDS AND SNOW POTENTIAL TO THE KEWEENAW AND OFF THE SHORELINE FROM GRAND MARAIS EASTWARD. THIS WILL ALSO BE AIDED BY THE LAND BREEZE THAT HAS DEVELOPED ALONG THE EASTERN U.P. SHORELINE AND WILL AID IN KEEPING THE BANDS OFFSHORE THERE. THE COVERAGE OF THE SHOWERS IS A LITTLE BIT OF A CONCERN DUE TO THE LIMITED MOISTURE...BUT WOULD EXPECT SOME UPTICK IN THE SNOW SHOWERS AS 875MB TEMPERATURES FALL FROM -11C ON THE RAP ANALYSIS TO -13/-14C BY THIS AFTERNOON. THUS...WILL CONTINUE TO SHOW POPS RAMPING UP TO HIGH CHANCES OVER THE KEWEENAW. WITH MUCH OF THE LAKE EFFECT CLOUD BELOW THE DGZ...WILL KEEP SNOW RATIOS ON THE LOW END FOR LAKE EFFECT AND ONLY HAVE ACCUMULATIONS AT A DUSTING TO AN INCH IN THAT AREA. OVER THE REST OF THE AREA...EXPECT A SUNNY START TO THE DAY WHICH WILL ALLOW TEMPERATURES TO RISE TO THE LOW-MID 20S THIS AFTERNOON. EXPECT MORE OF A FILTERED SUNSHINE IN THE AFTERNOON AS HIGH CLOUDS MOVE IN AHEAD OF THE WAVE BRUSHING THE AREA LATE TONIGHT. HEADING INTO TONIGHT...FOCUS TURNS TO THE SHORTWAVE CURRENTLY MOVING THROUGH WYOMING. THIS WAVE WILL QUICKLY SHIFT EAST THROUGH NEBRASKA AND SOUTH DAKOTA TODAY AND THEN LIFT NORTHEAST ACROSS NORTHERN LAKE MICHIGAN LATE TONIGHT AND SUNDAY MORNING. EXPECT THE HIGH CLOUDS TO THICKEN THIS EVENING AND MID CLOUDS TO MOVE IN DURING THE LATE EVENING AND OVERNIGHT. ANOTHER SHORTWAVE (CURRENTLY IN COLORADO) WILL LIFT NORTHEAST OUT AHEAD OF THE MAIN WAVE AND COULD PRODUCE A FEW SHOWERS AROUND MIDNIGHT. THE BETTER/MAIN FORCING (GENERALLY ABOVE 700MB) COMES FROM THE SECOND SHORTWAVE AND LOOKS TO STAY SOUTHEAST OF THE AREA...BUT DO EXPECT MENOMINEE COUNTY AND AREAS ALONG THE LAKE MICHIGAN SHORELINE TO SEE THE BEST OPPORTUNITY FOR ACCUMULATING SNOW. CURRENT FORECAST HAS SNOWFALL AMOUNTS UP TO AN INCH OVER SOUTHERN MENOMINEE COUNTY AND TAPERING OFF TO A HALF INCH OR LESS SOUTH OF A LINE FROM IRON MOUNTAIN TO MANISTIQUE. SINCE THE NORTHERN EDGE OF THE FORCING WILL BE JUST BRUSHING THE AREA...DO EXPECT A SHARP CUTOFF TO THE PRECIPITATION TO THE NORTHWEST AND KEEP THE SNOW CHANCES TO THE SOUTHEAST OF A LINE FROM MARQUETTE TO WATERSMEET. AS FOR THE LAKE EFFECT OVER THE KEWEENAW...THIS WAVE WILL BACK THE LOW LEVEL WINDS FARTHER TO THE SOUTHWEST AND FOCUS ANY LINGERING LAKE EFFECT TO THE FAR NORTHERN PORTIONS OF THE KEWEENAW PENINSULA. ACCUMULATIONS WILL REMAIN LIGHT AND BELOW 2 INCHES. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 258 PM EST SAT NOV 15 2014 UPPER LEVEL PATTERN TO BEGIN THE LONG TERM ON SUNDAY NIGHT SHOWS AMPLIFIED PATTERN WITH RIDGE OVER WESTERN CONUS AND INTO WESTERN CANADA AND DEEP TROUGHING DOWNSTREAM OVER CNTRL CONUS. MORE RIDGING WILL BE IN PLACE DOWNSTREAM OVER THE EASTERN CONUS. TROUGH DEEPENS OVER THE GREAT LAKES EARLY IN THE WEEK...THEN RELAXES SLIGHTLY BEFORE MORE TROUGHING BRINGS ANOTHER SHOT OF ARCTIC AIR OVER THE GREAT LAKES TOWARD END OF THE WEEK. JET ENERGY BECOMES MORE FOCUSED ON LEADING EDGE OF TROUGHING BY NEXT WEEKEND ALLOWING THE TROUGH TO MOVE EAST AND ALLOWING RIDGING WITH MODERATING TEMPERATURES TO RETURN TO THE GREAT LAKES BEGINNING NEXT WEEKEND. UNTIL THEN THE MAIN THEME OF THIS WEEK WILL BE COLD WITH LAKE EFFECT SNOW SHOWERS. INITIALLY AN UPPER LOW AND ASSOCIATED SFC LOW WORKS ACROSS LK SUPERIOR REGION ON MONDAY. TREND TOWARD A SLOWER FROPA WITH THE SYSTEM. FRONT SHOULD SWEEP ACROSS WETSERN CWA AROUND DAYBREAK ON MONDAY AND NOT REACH EASTERN CWA UNTIL MONDAY AFTN. BLYR WINDS SHIFT NW BEHIND THE FRONT AND THERE IS SUFFICIENT DEEPER MOISTURE TO H7-H6 FOR LAKE ENHANCED SNOW AS H85 TEMPS ARE AROUND -15C. LARGE SCALE FORCING WILL MAINLY BE TO THE EAST OF MUCH OF UPR MICHIGAN BY MONDAY AFTN...BUT EVEN THEN SOUNDINGS SHOW UNSTABLE PROFILE SFC-H7 WITH SUFFICIENT MOISTURE AND STRONG ENOUGH WINDS TO LEAD TO SNOW SHOWERS OVER MUCH OF UPR MICHIGAN. BY FAR THOUGH THE BEST CHANCE OF SNOW SHOWERS WILL BE TIED TO LAKE EFFECT FOR NW FLOW AREAS OVER WESTERN UPR MICHIGAN AND EVENTUALLY IN THE SNOW BELTS OVER EAST HALF OF UPR MICHIGAN AS OVER-WATER INSTABILITY IS VERY FAVORABLE WITH DELTA T/S OVER 20C AND LAKE EQ LEVELS OVER 15KFT. CYCLONIC FLOW SFC-H7 WILL ONLY ENHANCE THE CONVERGENCE AND SNOW SHOWER INTENSITY. EXPECT SOME OF THE HEAVIEST LAKE EFFECT SNOW TO OCCUR MONDAY AFTN/MONDAY NIGHT AND INTO TUESDAY WHEN THE DEEPER MOISTURE TO H7 IS PRESENT AND CYCLONIC FLOW IS STRONGEST. SFC-925MB WINDS INDICATE AREAS FAVORED BY NNW FLOW WILL SEE THE MOST CONCENTRATED LAKE EFFECT...HOWEVER H85-H7 WINDS ARE MORE FM THE N-NNW...SO THIS COULD BRING PERIODS OF LAKE EFFECT INTO AREAS FAVORED BY THAT FLOW REGIME AS WELL. OVERALL...MODERATE TO HEAVY LAKE EFFECT SNOW IS EXPECTED ALONG MUCH OF LK SUPERIOR LATER MONDAY INTO TUESDAY MORNING. MOISTURE OFF THE STILL OPEN WATERS OF LK NIPEGON COULD ALSO SERVE AS ENHANCEMENT FACTOR THE LAKE EFFECT. THERE ARE STILL TIMING AND LOCATION UNCERTAINTIES SO WILL NOT ISSUE ANY LAKE EFFECT SNOW WATCHES YET BUT WILL CONTINUE TO MENTION THE POTENTIAL FOR HEAVY LAKE EFFECT IN HAZARDOUS WEATHER OUTLOOK AND THE EHWO GRAPHICS. SHORTWAVE TROUGH MOVES EAST ON TUESDAY TAKING THE DEEP MOISTURE STEADILY OUT OF THE UPPER GREAT LAKES BY AFTERNOON. ALL THE WHILE EXPECT NW WINDS IN LAKE EFFECT MOIST LAYER TO BECOME MORE WESTERLY BY LATE IN THE DAY...PUSHING THE LAKE EFFECT SNOW SHOWERS ACROSS THE KEWEENAW AND ALONG LK SUPERIOR EAST OF MUNISING. AS ALLUDED TO BEFORE...LARGE SCALE TROUGH IS RE-INFORCED LATER IN THE WEEK AS A COUPLE OF SHORTWAVES DIVE ACROSS THE UPPER GREAT LAKES REGION. POSSIBLE THAT COULD SEE A SWATH OF WIDESPREAD LIGHT SNOW AS THESE WORK ACROSS LATE TUESDAY NIGHT INTO WEDNESDAY...THOUGH MOISTURE IS REALLY LACKING AS H7 MIXING RATIOS ARE BARELY ABOVE 1G/KG SUGGESTING JUST A DUSTING OF SNOW WOULD OCCUR AWAY FM THE GREAT LAKES. APPEARS THAT THERE MAY BE BRIEF OPPORTUNITY FOR LAKE ENHANCED SNOW OFF LK MICHIGAN AS WINDS BACK FM WSW TO SSW AS WITH FORCING PRESENT AND AS H85 TEMPS ARE AROUND -10C. FOR MOST PART THOUGH...THINK BETTER LAKE ENHANCEMENT STAYS JUST EAST OF THE CWA. AS SECOND SHORTWAVE MOVES THROUGH LATER ON WEDNESDAY ALONG WITH SUB 1000MB SFC LOW AND COLD FRONT...LIKELY WILL SEE ANOTHER ROUND OF MODERATE TO HEAVY LAKE ENHANCED SNOW KICK UP AGAIN WITH H85 TEMPS AROUND -14C AND MORE DEEPER MOISTURE THROUGH H7. BASED ON UNIDIRECTIONAL FLOW SFC-H7 THE MOST SNOW WOULD OCCUR ESPECIALLY FOR AREAS FAVORED BY WNW WINDS. LAKE EFFECT WILL BE ON THE MOVE AGAIN ON THURSDAY...HEADING TOWARD AREAS FAVORED BY NORTHWEST WINDS. MID SHIFT HIGHLIGHTED THIS TIME FRAME FOR HEAVY LAKE EFFECT SNOW POTENTIAL IN THE HWO AND EHWO GRAPHICS. WILL FOLLOW SUIT WITH THIS FORECAST. INSTENSITY FOR LAKE EFFECT BEGINS TO DIMINISH LATER THURSDAY AND CERTAINLY BY FRIDAY AS SOUNDINGS INDICATE INVERSIONS LOWERING TO AROUND 5KFT INSTEAD OF THE MORE ROBUST 10KFT+ THEY ARE FOR MOST OF THE WEEK. MORE ANTICYCLONIC LOW-LEVEL FLOW WITH APPROACHING RIDGE WILL ALSO KNOCK DOWN INTENSITY OF SNOW SHOWERS AND LEAD TO LESS COVERAGE OF THE LAKE EFFECT. WINDS BACK WSW-SW FRIDAY NIGHT INTO SATURDAY AS HIGH PRESSURE RIDGE ARRIVES. BETWEEN BACKING WINDS AND WARMING TEMPS IN LOW-LEVELS... LAKE EFFECT SNOW SHOWERS SHOULD END BY SATURDAY. 12Z GFS SHOWS DECENT WARM AND MOIST ADVECTION SNOW ON BACK SIDE OF RIDGE. NO CONSISTENCY WITH PREVIOUS RUNS THOUGH NOR THE ECMWF WHICH HAS THE AREA MAINLY DRY. 12Z GFS REPRESENTS JUST A HIGHER-END SNOW ENSEMBLE MEMBER AT THIS POINT. GIVEN THE DEPTH OF THE COLD AIR DOME THAT WILL BE RETREATING BY THAT TIME...COULD SEE SOME ISENTROPIC LIFT TYPE SNOW...BUT JUST NOT SURE IT WILL BE TO THE EXTENT THE GFS SHOWS. WILL GO WITH CONSENSUS OF MODELS ATTM AND WE CAN FINE TUNE FOR LATER FORECASTS. WARMING TREND DOES APPEAR TO BEGIN ON SATURDAY WHICH MAY RESULT IN TEMPS JUST BEYOND THE EXTENDED REACHING BACK ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1245 PM EST SAT NOV 15 2014 GUSTY WESTERLY WINDS OFF LAKE SUPERIOR WILL CONTINUE TO LEAD TO LAKE EFFECT CLOUDS /HIGH END MVFR/LOW END VFR/ WITH OFF AND ON SNOW SHOWERS AND BLOWING SNOW REDUCING VIS TO AROUND 6SM AT TIMES THROUGH EARLY EVENING. FOR KIWD/KSAW...EXPECT VFR CONDITIONS DUE TO UNFAVORABLE WIND DIRECTIONS FOR LAKE EFFECT. AN APPROACHING UPPER LEVEL DISTURBANCE WILL LEAD TO INCREASING HIGH/MID CLOUDS THIS AFTERNOON-TONIGHT. KSAW WILL BE THE CLOSEST FOR SOME SNOW SHOWERS...AND HAVE ADDED THE POTENTIAL FROM 11-16Z AS CEILINGS FALL TO MVFR. EXPECT SW WINDS TO INCREASE AT ALL 3 SITES SUNDAY MORNING WITH GUSTS NEARING 20KTS PRIOR TO 18Z. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EST SAT NOV 15 2014 UNDER A SHARP PRES GRADIENT BETWEEN HI PRES IN THE OH RIVER VALLEY AND LO PRES OVER HUDSON BAY...PLAN ON W WINDS UP TO 20-30KTS INTO SUN. THE WINDS WL THEN BACK TOWARD THE SW AND DIMINISH TO UP TO 25KTS IN ADVANCE OF ANOTHER STRONG DISTURBANCE MOVING THRU SCENTRAL CANADA AND INTO NORTHERN LAKE SUPERIOR ON MON MORNING. FOLLOWING THE PASSAGE OF THIS LO TO THE E...THE PRES GRADIENT WILL TIGHTEN AND THE INSTABILITY WILL INCREASE AS ANOTHER SURGE OF COLD AIR FLOWS OVER THE RELATIVELY WARM LAKE WATERS. THE RESULT WILL BE A PERIOD OF NW GALES ON MON INTO TUE. SINCE THIS AIRMASS WILL BE SUFFICIENTLY COLD...THERE WILL LIKELY BE SOME FREEZING SPRAY IN SOME AREAS. THE BEST CHANCE FOR THE GALES WILL BE OVER CENTRAL LAKE SUPERIOR. AS THE LO PRES MOVES AWAY ON TUE AND HI PRES SHIFTS E...EXPECT THE WINDS TO BACK TO THE W AND DIMINISH TO 25 TO 30KTS. THE PASSAGE OF ANOTHER STRONG DISTURBANCE ON WED MAY LEAD TO ANOTHER NW GALE EVENT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...JLA AVIATION...KF MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1246 PM EST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 416 AM EST SAT NOV 15 2014 A QUIET START TO THE SHORT TERM FORECAST THIS MORNING...AS THE AREA IS ON THE NORTHEAST EDGE OF A HIGH CENTERED FROM THE MID/UPPER MISSISSIPPI VALLEY TO THE OHIO RIVER VALLEY. THIS HAS LED TO A CLEAR AND COLD NIGHT ACROSS AT LEAST HALF OF THE CWA. WHERE WINDS HAVE DECOUPLED (GENERALLY ACROSS THE INTERIOR WEST AND NEAR THE WISCONSIN BORDER)...TEMPERATURES HAVE FALLEN INTO THE SINGLE DIGITS BELOW ZERO. MEANWHILE...OVER THE CENTRAL AND EAST WHERE THE WINDS HAVE BEEN STAYING UP...TEMPERATURES HAVE BEEN IN THE UPPER SINGLE DIGITS ABOVE ZERO TO MID TEENS. OVER LAKE SUPERIOR AND THE KEWEENAW...COLD AIR CONTINUING TO FLOW OVER THE RELATIVELY WARM WATERS OF LAKE SUPERIOR WAS PRODUCING MAINLY LAKE EFFECT CLOUDS THIS PAST EVENING AND INTO THE EARLY OVERNIGHT HOURS. BUT STARTED SEEING WEAK LAKE EFFECT BANDS OVER EASTERN LAKE SUPERIOR ON THE CANADIAN RADAR AT MONTREAL RIVER SHORTLY AFTER MIDNIGHT. INVERSION IS RIGHT AT 875-850MB ON 00Z KGRB/KINL SOUNDINGS AND THE LIMITED MOISTURE ON THE NORTH EDGE OF THE HIGH HAVE BEEN THE MAIN LIMITING FACTORS TO LAKE EFFECT SNOW EARLY THIS MORNING. KMQT VWP HAS BEEN SHOWING THE WINDS A LITTLE MORE OUT OF THE WEST-NORTHWEST AND CONTRIBUTING TO THE LAKE EFFECT CLOUDS NOSING SOUTHEAST INTO BARAGA...SOUTHERN HOUGHTON...AND EVEN FAR NORTHERN IRON COUNTY EARLY THIS MORNING. BUT AS WE HEAD INTO THE MORNING HOURS...MODELS SHOWING THE WINDS GOING BACK TO A MORE WESTERLY AND POTENTIALLY WEST-SOUTHWESTERLY DIRECTION AND CONFINING THE LAKE EFFECT CLOUDS AND SNOW POTENTIAL TO THE KEWEENAW AND OFF THE SHORELINE FROM GRAND MARAIS EASTWARD. THIS WILL ALSO BE AIDED BY THE LAND BREEZE THAT HAS DEVELOPED ALONG THE EASTERN U.P. SHORELINE AND WILL AID IN KEEPING THE BANDS OFFSHORE THERE. THE COVERAGE OF THE SHOWERS IS A LITTLE BIT OF A CONCERN DUE TO THE LIMITED MOISTURE...BUT WOULD EXPECT SOME UPTICK IN THE SNOW SHOWERS AS 875MB TEMPERATURES FALL FROM -11C ON THE RAP ANALYSIS TO -13/-14C BY THIS AFTERNOON. THUS...WILL CONTINUE TO SHOW POPS RAMPING UP TO HIGH CHANCES OVER THE KEWEENAW. WITH MUCH OF THE LAKE EFFECT CLOUD BELOW THE DGZ...WILL KEEP SNOW RATIOS ON THE LOW END FOR LAKE EFFECT AND ONLY HAVE ACCUMULATIONS AT A DUSTING TO AN INCH IN THAT AREA. OVER THE REST OF THE AREA...EXPECT A SUNNY START TO THE DAY WHICH WILL ALLOW TEMPERATURES TO RISE TO THE LOW-MID 20S THIS AFTERNOON. EXPECT MORE OF A FILTERED SUNSHINE IN THE AFTERNOON AS HIGH CLOUDS MOVE IN AHEAD OF THE WAVE BRUSHING THE AREA LATE TONIGHT. HEADING INTO TONIGHT...FOCUS TURNS TO THE SHORTWAVE CURRENTLY MOVING THROUGH WYOMING. THIS WAVE WILL QUICKLY SHIFT EAST THROUGH NEBRASKA AND SOUTH DAKOTA TODAY AND THEN LIFT NORTHEAST ACROSS NORTHERN LAKE MICHIGAN LATE TONIGHT AND SUNDAY MORNING. EXPECT THE HIGH CLOUDS TO THICKEN THIS EVENING AND MID CLOUDS TO MOVE IN DURING THE LATE EVENING AND OVERNIGHT. ANOTHER SHORTWAVE (CURRENTLY IN COLORADO) WILL LIFT NORTHEAST OUT AHEAD OF THE MAIN WAVE AND COULD PRODUCE A FEW SHOWERS AROUND MIDNIGHT. THE BETTER/MAIN FORCING (GENERALLY ABOVE 700MB) COMES FROM THE SECOND SHORTWAVE AND LOOKS TO STAY SOUTHEAST OF THE AREA...BUT DO EXPECT MENOMINEE COUNTY AND AREAS ALONG THE LAKE MICHIGAN SHORELINE TO SEE THE BEST OPPORTUNITY FOR ACCUMULATING SNOW. CURRENT FORECAST HAS SNOWFALL AMOUNTS UP TO AN INCH OVER SOUTHERN MENOMINEE COUNTY AND TAPERING OFF TO A HALF INCH OR LESS SOUTH OF A LINE FROM IRON MOUNTAIN TO MANISTIQUE. SINCE THE NORTHERN EDGE OF THE FORCING WILL BE JUST BRUSHING THE AREA...DO EXPECT A SHARP CUTOFF TO THE PRECIPITATION TO THE NORTHWEST AND KEEP THE SNOW CHANCES TO THE SOUTHEAST OF A LINE FROM MARQUETTE TO WATERSMEET. AS FOR THE LAKE EFFECT OVER THE KEWEENAW...THIS WAVE WILL BACK THE LOW LEVEL WINDS FARTHER TO THE SOUTHWEST AND FOCUS ANY LINGERING LAKE EFFECT TO THE FAR NORTHERN PORTIONS OF THE KEWEENAW PENINSULA. ACCUMULATIONS WILL REMAIN LIGHT AND BELOW 2 INCHES. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 409 AM EST SAT NOV 15 2014 A HI AMPLITUDE PATTERN FEATURING A TROF OVER CENTRAL AND ERN NAMERICA DOWNSTREAM OF A RDG ALONG THE W COAST WL DOMINATE THE WX PATTERN THIS COMING WEEK...LEADING TO PERSISTENT BLO TO WELL BLO NORMAL TEMPS THRU THE WEEK. THE MOST SGNFT WX CONCERN WL BE THE IMPACT OF A POTENT SHRTWV THAT IS FCST TO DIG SEWD THRU THE UPR LKS EARLY IN THE WEEK AND AMPLIFY THE TROF. THIS DISTURBANCE WL ALMOST CERTAINLY BRING ANOTHER ROUND OF MODERATE TO HEAVY LES AND SOME BLSN MAINLY TO THE NW WIND SN BELTS NEAR LK SUP ON MON INTO TUE. YET ANOTHER DISTURBANCE DIGGING THRU THE UPR TROF MAY BRING MORE SGNFT LES ON WED INTO THU. SUN...ONGOING LIGHT SN OVER THE SE CWA WL END BY EARLY IN THE AFTN AS SHRTWV OVER ERN WI AT 12Z AND ACCOMPANYING DYNAMIC FORCING/ DEEPER MSTR EXIT TO THE E THRU LOWER MI AND INTO FAR SE ONTARIO IN THE AFTN. AXIS OF DRIER AIR/DEEP LYR QVECTOR DVGC BTWN THIS DEPARTING SHRTWV AND ANOTHER MORE POTENT SHRTWV DIGGING SE THRU SCENTRAL CANADA WL THEN BRING A PERIOD OF DRY WX TO THE CWA. ALTHOUGH H85 TEMPS ARE FCST TO BE AS LO AS -12 TO -13C...THE FCST 230 DEGREE LLVL FLOW IN ADVANCE OF THE APRCHG SHRTWV WL HOLD ANY LES MAINLY TO THE NW OF THE KEWEENAW PENINSULA AND E OF LUCE/SCHOOLCRAFT COUNTIES. ALTHOUGH DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THE INCOMING SHRTWV ARE FCST TO INVADE THE WRN CWA LATER IN THE DAY... THE ABSENCE OF ANY SGNFT LLVL MSTR INFLOW WL MAINTAIN DRY WX THRU 00Z MON UNDER INCRSG HI/MID CLDS. SUN NIGHT...INCOMING SHRTWV/SFC LO ARE FCST TO DRIFT OVER NRN LK SUP BY 12Z MON AND CAUSE 12HR H5 HGT FALLS UP TO 120M ACROSS THE UPR LKS. AXIS OF DPVA/DEEP LYR QVECTOR CNVGC WITHIN THE COMMA TAIL OF THIS FEATURE ARE FCST TO SWING ACROSS UPR MI. HOWEVER...POTENTIAL FOR WIDESPREAD SN IN ADVANCE OF THE SHRTWV WL BE LIMITED BY THE ABSENCE OF LLVL MOISTENING/PWAT UNDER 0.25 INCH/H7 SPECIFIC HUMIDITY NO MORE THAN ABOUT 1 G/KG. STILL LOOKS LIKE THE LLVL FLOW WL NOT BACK SUFFICIENTLY TO ALLOW ANY LK ENHANCED OFF LK MI TO IMPACT LUCE OR SCHOOLCRAFT COUNTIES. THE BEST CHC FOR MORE WIDESPREAD/HEAVIER SNOW WL BE OVER THE W MAINLY LATE FOLLOWING COLD FROPA AND WIND SHIFT TO AN UPSLOPE NW DIRECTION. ARRIVAL OF H85 TEMPS AROUND -15C WITH SHARP CYC FLOW/LINGERING DEEP MSTR UNDER THE FALLING HGTS WILL WARRANT KEEPING LIKELY TO CATEGORICAL POPS OVER THE W. WL GO NO HIER THAN CHC POPS ELSEWHERE...WITH THE LOWEST SCHC POPS OVER THE SCENTRAL. MON/MON NGT...AS THE UPR TROF DEEPENS INTO THE GREAT LKS AND A CLOSED H5 LO FORMS...UPR MI IS FCST TO BE UNDER SHARP...CYC W VEERING NW FLOW ON MON AND NNW-NW FLOW ON MON NGT. FCST SDNGS SHOW DEEP MOISTURE/INSTABILITY AS H5 TEMPS DIP TOWARD -40C. GIVEN H85 TEMPS FALLING TO -16C TO -18C AND THE DEEP INSTABILITY/MOISTURE WITH THE CYC LLVL FLOW...CATEGORICAL POPS ARE WARRANTED IN THE FAVORED SN BELTS. GUSTY WINDS UNDER THE SHARP PRES GRADIENT/DESTABILIZATION WL CAUSE BLSN IN ADDITIONAL TO THE HEAVIER LES. FAVORABLE OMEGA PROFILE WITHIN THE DGZ SITUATED BTWN ABOUT 1-5K FT AGL WL ALSO ENHANCE SN/WATER RATIOS DESPITE THE IMPACT OF THE STRONG WINDS TO FRAGMENT THE SN FLAKES. RIGHT NOW... THE FAR W IN ONTONAGON/GOGEBIC COUNTIES LOOKS TO PICK UP THE HEAVIEST SN ON MON NGT...WITH ADDITIONAL HEAVY LES IMPACTING AREAS E OF MARQUETTE LATER ON MON THRU MON NGT. LATER SHIFTS NO DOUBT WL NEED TO HOIST LES HEADLINES. THE STRONG NW WINDS MAY ALSO CAUSE HI ENOUGH WAVES ON LK SUPERIOR TO BRING SOME MINOR BEACH EROSION/FLOODING IN AREAS MOST EXPOSED TO THE HIER WINDS/WAVES BEGINNING ON LATE MON. FOR NOW...WL CONTINUE TO MENTION THE SGFNT LES POTENTIAL/BLSN AND HI WAVES IN THE HWO PRODUCT AND EHWO GRAPHICS. TUE/TUE NGT...AS THE CLOSED LO SHIFTS INTO QUEBEC AND 12HR H5 HGT RISES APRCH 100M ON TUE IN THE LARGER SCALE DNVA AHEAD OF TRAILING H5 RDG AXIS...MID LVL SUBSIDENCE/DRYING/TREND TOWARD NEUTRAL OR MORE ACYC LLVL FLOW WL TEND TO WEAKEN THE LES W TO E. STEADILY BACKING WINDS OVER THE W THRU THE DAY AND MAINLY DURING TUE AFTN OVER THE E WL TEND TO LIMIT THE RESIDENCE TIME OF THE HEAVIER SN BANDS AND SHIFT THE LES TO PRIMARILY OVER THE KEWEENAW AND TO THE E OF MUNISING BY LATE IN THE DAY. DESPITE THIS DIMINISHING TREND...SN TOTALS ON MON THRU TUE WL LIKELY APRCH OR EXCEED A FOOT IN THE FAVORED SN BELTS OVER THE W CENTERED IN ONTONAGON COUNTY AND E OF MUNISING. AS THE FLOW CONTINUES TO BACK TOWARD THE SW ON TUE NGT IN ADVANCE OF NEXT CLIPPER SHRTWV DIGGING SEWD TOWARD MN...THE MAIN AREA OF LES SHOULD SHIFT INTO LK SUP. BUT MORE WIDESPREAD SN MAY ARRIVE LATE AT NGT AT LEAST OVER THE W WITH THE ONSET OF MORE VIGOROUS DYNAMIC FORCING/HGT FALLS IN THE DPVA AHEAD OF THE NEXT SHRTWV. WED THRU FRI...PASSAGE OF POTENT SHRTWV/VIGOROUS DYNAMIC FORCING WL BRING THE THREAT OF A MORE WIDESPREAD SN AGAIN ON WED DESPITE RATHER LIMITED ABSOLUTE MSTR /FCST PWAT UNDER 0.25 INCH/. MORE LES WL BE THE RULE ON THU INTO FRI MAINLY IN THE NW WIND SN BELTS AS ANOTHER COLD SHOT WITH H85 TEMPS AS LO AS -16 TO -18C POURS INTO THE UPR LKS BEHIND THE DEPARTING SHRTWV. LONGER RANGE MODELS CONTINUE TO POINT TOWARD SOME MODERATION IN THE COLD NEXT WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1245 PM EST SAT NOV 15 2014 GUSTY WESTERLY WINDS OFF LAKE SUPERIOR WILL CONTINUE TO LEAD TO LAKE EFFECT CLOUDS /HIGH END MVFR/LOW END VFR/ WITH OFF AND ON SNOW SHOWERS AND BLOWING SNOW REDUCING VIS TO AROUND 6SM AT TIMES THROUGH EARLY EVENING. FOR KIWD/KSAW...EXPECT VFR CONDITIONS DUE TO UNFAVORABLE WIND DIRECTIONS FOR LAKE EFFECT. AN APPROACHING UPPER LEVEL DISTURBANCE WILL LEAD TO INCREASING HIGH/MID CLOUDS THIS AFTERNOON-TONIGHT. KSAW WILL BE THE CLOSEST FOR SOME SNOW SHOWERS...AND HAVE ADDED THE POTENTIAL FROM 11-16Z AS CEILINGS FALL TO MVFR. EXPECT SW WINDS TO INCREASE AT ALL 3 SITES SUNDAY MORNING WITH GUSTS NEARING 20KTS PRIOR TO 18Z. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EST SAT NOV 15 2014 UNDER A SHARP PRES GRADIENT BETWEEN HI PRES IN THE OH RIVER VALLEY AND LO PRES OVER HUDSON BAY...PLAN ON W WINDS UP TO 20-30KTS INTO SUN. THE WINDS WL THEN BACK TOWARD THE SW AND DIMINISH TO UP TO 25KTS IN ADVANCE OF ANOTHER STRONG DISTURBANCE MOVING THRU SCENTRAL CANADA AND INTO NORTHERN LAKE SUPERIOR ON MON MORNING. FOLLOWING THE PASSAGE OF THIS LO TO THE E...THE PRES GRADIENT WILL TIGHTEN AND THE INSTABILITY WILL INCREASE AS ANOTHER SURGE OF COLD AIR FLOWS OVER THE RELATIVELY WARM LAKE WATERS. THE RESULT WILL BE A PERIOD OF NW GALES ON MON INTO TUE. SINCE THIS AIRMASS WILL BE SUFFICIENTLY COLD...THERE WILL LIKELY BE SOME FREEZING SPRAY IN SOME AREAS. THE BEST CHANCE FOR THE GALES WILL BE OVER CENTRAL LAKE SUPERIOR. AS THE LO PRES MOVES AWAY ON TUE AND HI PRES SHIFTS E...EXPECT THE WINDS TO BACK TO THE W AND DIMINISH TO 25 TO 30KTS. THE PASSAGE OF ANOTHER STRONG DISTURBANCE ON WED MAY LEAD TO ANOTHER NW GALE EVENT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...KC AVIATION...KF MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
351 PM CST SAT NOV 15 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 351 PM CST SAT NOV 15 2014 STEADY LIGHT SNOW HAS ENGULFED SOUTHERN MN IN LIGHT SNOW THROUGH THE DAY...WITH THE HEAVIEST BAND SETTING UP ALONG THE IOWA BORDER AS EXPECTED. FOR THE REMAINDER OF THE AFTERNOON...WE`RE EXPECTING MOST OF THE SNOW IN SOUTHERN MN TO WEAKEN AS FORCING WANES...AND THE F-GEN MAX SLIDES SOUTH INTO IOWA...AS FRONTOLYSIS TAKES OVER ACROSS WEST CENTRAL THROUGH SOUTHERN MN. THIS TREND IS QUITE APPARENT ON RADAR AND HAS BEEN HANDLED WELL BY THE HRRR FOR THE LAST SEVERAL RUNS. SO...EXPECT A LULL FOR MUCH OF THE AFTERNOON AND THE EVENING. ANOTHER DECENT SNOW BAND WILL DEVELOP LATER TONIGHT. IT WILL CROSS THE MN/SD BORDER AROUND 6-7 PM AND CONTINUE EASTWARD...PRODUCING LIGHT ACCUMULATIONS ACROSS THE SOUTHERN HALF OF THE STATE AND THROUGH WEST CENTRAL WI. FOR THE TWIN CITIES...THIS BAND WILL PRODUCE AN ADDITIONAL 0.5"-1" MAINLY FROM 9PM THROUGH 1AM. CURRENTLY EXPECTING THE BACK EDGE OF THIS BAND TO CROSS THE MN/WI LINE AT ABOUT 3AM...WITH LIGHT SNOW LINGERING UNTIL 5-6AM NEAR EAU CLAIRE. OVERNIGHT TEMPERATURES LAST NIGHT WERE A GOOD FIVE DEGREES COLDER THAN EXPECTED OVER THE SOLID SNOW PACK. IN COLLABORATION WITH OTHER OFFICES...WENT SLIGHTLY COOLER ACROSS THE WEST THAN MOST OF THE GUIDANCE...BUT THE EASTERN CWA WILL RETAIN SOMEWHAT WARMER TEMPERATURES UNDER CONSISTENT CLOUD COVER /AND LINGERING LIGHT PRECIP OVERNIGHT/. BY TOMORROW MORNING...WINDS WILL HAVE TURNED WESTERLY AND WILL INCREASE THROUGH THE DAY. STRONG CAA APPARENT AT 925H ON THE BACKSIDE OF THE WAVE WILL MAKE FOR A COLD SUNDAY. 925H TEMPS AROUND -12C ACROSS MOST OF THE REGION WILL ONLY ALLOW SURFACE TEMPS TO MIX INTO THE UPPER TEENS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 351 PM CST SAT NOV 15 2014 THE WEEK AHEAD REMAINS EXTREMELY COLD FOR MID NOVEMBER WITH THREE SURGES OF ARCTIC AIR FORECAST ACROSS THE UPPER MISSISSIPPI VALLEY. THE FIRST IS SUNDAY NIGHT/MONDAY...THE SECOND TUESDAY NIGHT/WEDNESDAY WITH THE THIRD ON THURSDAY. LOWS/HIGHS THROUGH THE PERIOD WILL CONTINUE TO AVERAGE SOME 20 TO 30 DEGREES BELOW NORMAL. THE TREND TODAY WAS TO CONTINUE LOWERING TEMPERATURES OVER THE BLENDED GUIDANCE DUE TO A MORE EXPANSIVE SNOW PACK. THE ARCTIC SURGE THAT OCCURS SUNDAY NIGHT/MONDAY OFFERS THE BEST CHANCE FOR SNOW SHOWERS...ESPECIALLY ACROSS CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN...WHERE A FLUFFY INCH OR TWO COULD OCCUR. THE OTHER TWO ARCTIC SURGES HAVE THE BETTER MOISTURE AND FORCING TO THE NORTHEAST OF OUR FORECAST AREA RESULTING IN LESS CHANCES FOR SNOW FOR US. THE MAIN CONCERN IN THE LONG TERM IS THE BLOWING SNOW POTENTIAL IN THE MINNESOTA RIVER VALLEY SUNDAY NIGHT AND MONDAY. THE CONCERN FOR BLIZZARD CONDITIONS DEVELOPING ON MONDAY HAS WANED A BIT TODAY AS ALL OF THE DETERMINISTIC MODELS HAVE DECREASED THE SURFACE PRESSURE GRADIENT ACROSS THE MN FORECAST AREA FROM 10 MB TO 8 MB IN THE PAST 24 HOURS. THIS HAS LOWERED WIND SPEED FORECASTS A LITTLE ON MONDAY FROM KRWF TO KFRM. IN ADDITION...SNOWFALL ACCUMULATION SO FAR TODAY HAS BEEN HIGHEST IN EASTERN SOUTH DAKOTA AND FAR SOUTHWEST MINNESOTA (OUTSIDE OF OUR FORECAST AREA) WHERE 3 TO 5 INCHES HAVE BEEN COMMON. SNOWFALL IN OUR AREA OF WEST CENTRAL THROUGH SOUTH CENTRAL MINNESOTA HAS BEEN MORE IN THE 1 TO 3 INCH RANGE. BUFKIT PROFILES FROM BOTH THE NAM AND GFS SHOW THAT THE BEST LOW LEVEL LAPSE RATES AND HIGHEST TOP OF THE CHANNEL MOMENTUM TRANSFER DON/T OCCUR UNTIL LATE MONDAY MORNING AND AFTERNOON FROM WEST CENTRAL THROUGH SOUTH CENTRAL MINNESOTA. ALTHOUGH AREAS OF BLOWING SNOW WILL BEGIN ACROSS WEST CENTRAL THROUGH SOUTH CENTRAL MINNESOTA SUNDAY NIGHT IN THE WAKE OF THE ARCTIC FRONT...THERE ARE STILL SOME INDICATIONS THAT SUSTAINED WIND SPEEDS COULD REACH 25 MPH FROM KRWF TO KFRM MONDAY AFTERNOON WITH GUSTS HITTING 40 MPH. THIS COULD RESULT IN NEAR BLIZZARD CONDITIONS FOR A COUPLE OF HOURS IN THESE AREAS. COMPLICATING MATTERS IS THE THREAT FOR SNOW SHOWERS ALONG WITH THE SATURATED LOW LEVEL CONDITIONS REMAINING IN THE DENDRITIC GROWTH ZONE. AT THIS POINT...DIDN/T HAVE ENOUGH CONFIDENCE TO ISSUE A BLIZZARD WATCH FOR MONDAY FROM YELLOW MEDICINE AND RENVILLE COUNTIES ON SOUTHEAST TO MARTIN AND FARIBAULT WITH THE PRESSURE GRADIENT WEAKENING SOME AND THE HIGHER SNOW TOTALS TODAY TO OUR WEST. THERE IS STILL PLENTY OF TIME LATER TONIGHT TO ISSUE A WATCH IF WIND CONDITIONS CHANGE WITH THE 00Z MODEL RUNS. OTHERWISE...A WINTER WEATHER ADVISORY FOR BLOWING SNOW WILL LIKELY BE ISSUED ON SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1145 AM CST SAT NOV 15 2014 SNOW FORECAST REMAINS ON TRACK TODAY. ALREADY A FEW INCHES OF ACCUMULATION HAS BEEN REPORTED ALONG THE IOWA BORDER. THAT AREA IS STILL ULTIMATELY EXPECTED TO RECEIVE THE HIGHEST ACCUMULATIONS...IN THE 3-6" RANGE BY TOMORROW MORNING. WIDESPREAD IFR VIS EXPECTED TO CONTINUE THROUGH EARLY AFTERNOON...AND GUIDANCE CONTINUES TO INDICATE SNOW INTENSITIES WILL LIGHTEN UP FOR A PERIOD THIS AFTERNOON AS THE BEST PRE FRONTAL FORCING SHIFTS AWAY TO THE SOUTHEAST. THIS EVENING THOUGH...THE FORCING ASSOCIATED WITH THE MAIN WAVE WILL MOVE THROUGH SOUTHERN MN AND WE SHOULD SEE RADAR RETURNS INTENSIFY SOME. INDICATED THIS IN MANY SITES WITH A RISE IN VSBY DURING THE LATE AFTERNOON...BUT EXPECT THOSE TO RETURN TO IFR TONIGHT. AS FAR AS EXTENT OF THE SNOW...AXN WILL BE LEAST AFFECTED WITH BR OR HAZE BEING MORE OF A VSBY REDUCTION THAN PURE SNOWFALL. LOOKING FOR THE SNOW TO END OVERNIGHT FROM WEST TO EAST...REACHING THE WI BORDER BY AROUND 09Z-10Z. AFTER THAT...A FEW HOURS OF MVFR CIGS FOLLOWED BY VFR FOR MOST AREAS THROUGH THE MORNING ON SUNDAY. WE`LL START TO SEE SW WINDS INCREASING AND BECOMING GUSTY LATE IN THE MORNING AND INTO THE AFTERNOON. KMSP...VSBY REDUCTIONS SO FAR IN LARGE PART DUE TO BR...SO NOT MUCH ACCUMULATION DESPITE VSBYS AROUND 1SM FOR THE LAST FEW HOURS. STILL EXPECT A BIT OF A LULL THIS AFTERNOON...WITH RE-INTENSIFICATION LATE TONIGHT AS THE MAIN WAVE MOVES THROUGH. STILL EXPECT AROUND AN INCH OF ACCUMULATION AT THE AIRFIELD WHEN ITS ALL SAID AND DONE. /OUTLOOK FOR KMSP/ MON...SLIGHT CHC -SN WITH IFR/MVFR CIGS. WINDS NW 15-20 G 25 KTS. TUE...VFR. WINDS W 10-15 KTS. WED...VFR. WINDS NW 10-15 KTS G 20 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ073>076-082>085-091>093. WI...NONE. && $$ SHORT TERM...SPD LONG TERM...RAH AVIATION...SPD
AREA FORECAST DISCUSSION
NWS JACKSON MS
1050 AM CST SAT NOV 15 2014 .UPDATE... FORECAST IS ON TRACK WITH ONLY ADJUSTMENTS MADE TO CLOUD COVER FOR TODAY. && .DISCUSSION... WEAK ISENTROPIC LIFT IN 285-290K LAYER IS SUPPORTING CLOUD DECK MOVING INTO NE LA/SE AR AND SW MS...BUT MOST RECENT HRRR GUIDANCE INDICATES THE DECK WILL DISSIPATE BEFORE GETTING INTO CENTRAL/ERN MS THIS AFTN WHERE HIGHER CONDENSATION PRESSURE DEFICITS AND NEUTRAL PRESSURE ADVECTION ARE FORECAST. HAVE INCREASED THE CLOUD GRADIENT ACROSS THE AREA KEEPING EASTERN MS SUNNY. INCREASED CLOUD COVER OVER WESTERN PORTIONS OF THE AREA SHOULD NOT KEEP TEMPERATURES DOWN TOO MUCH GIVEN INCREASED SE SFC FLOW. /EC/ && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE EVENING HOURS AT MOST AREA TERMINALS. DURING THE LATE OVERNIGHT OR EARLY SUNDAY MORNING...CIGS WILL BEGIN TO LOWER WITH RAIN BEGINNING TO SRPEAD ACROSS THE AREA. MVFR CEILINGS WILL BECOME LIKELY AFTER DAYBREAK... POSSIBLY LOWERING TO IFR LATER IN THE DAY. THERE WILL ALSO BE OCCASIONAL REDUCTIONS TO MVFR VISIBILITY IN HEAVIER RAINFALL DURING THE DAY SUNDAY. /DL/ && .PREV DISCUSSION... /ISSUED 425 AM CST SAT NOV 15 2014/ SHORT TERM...GOOD RADIATIONAL COOLING NIGHT UNDERWAY ACROSS THE AREA AS TEMPS HAVE SETTLED AS EXPECTED IN THE MID/UPPER 20S. THE EXCEPTION HAS BEEN OVER FAR SW PORTIONS WHERE EASTWARD FRINGES OF LOW CLOUD DECK OVER TX/LA HAVE KEPT TEMPS FROM FALLING OFF TO THEIR FULL POTENTIAL. CLOUD DECK OVER TX/LA IS A RESULT OF THE BEGINNINGS OF LOW LEVEL ISENTROPIC ASCENT IN ADVANCE OF DIGGING SYSTEM OVER THE ROCKIES. THIS DECK WILL ONLY THICKEN AND CONTINUE SPREADING EAST TODAY. VEERING LOW LEVEL WINDS ALONG THE UPPER TX/LA COASTS TODAY WILL INTERACT WITH COASTAL BAROCLINIC ZONE LEADING TO FRONTOGENESIS AND A SURGING WARM FRONT NORTHWARD OVERNIGHT. AS DEEP LAYER SOUTHERLY FLOW INCREASES...GOOD ISENTROPIC ASCENT WILL ALLOW RAIN TO BEGIN BREAKING OUT FROM THE WEST MAINLY AFTER MIDNIGHT. AS THE MID/UPPER LEVEL SYSTEM PULLS OUT OF THE PLAINS INTO THE LOWER MS VALLEY SUNDAY...INCREASING DIFFLUENCE ALOFT WILL LEAD TO SURFACE CYCLOGENESIS ALONG THE BOUNDARY OVER CENTRAL LA. AS THIS OCCURS THE FRONTOGENETICAL FORCING WILL DRASTICALLY INCREASE...ESPECIALLY TO THE NORTH AND EAST OF THE SURFACE LOW. WITH DEEP MOISTURE ALREADY IN PLACE...THE ORIENTATION OF THETA-E WILL BE NEARLY UPRIGHT OVER THE TOP OF THE BOUNDARY. THIS SHOULD EASILY LEAD TO FORCED CONVECTION WITH THE 50+ KNOT FLOW BOUND TO THETA-E SURFACES. WHILE SOUNDINGS FOR THE MOST PART WILL BE MOIST ADIABATIC...MODELS SOUNDINGS AND PROFILES ARE SHOWING SOME MAUL POTENTIAL IN THE H8-H6 LAYER DUE TO STRONG CONDENSATIONAL LATENT HEATING OVERTOP THE BOUNDARY. THIS WILL LEAD TO SOME RATHER ROBUST UPDRAFTS WITH THE POSSIBILITIES FOR SPORADIC THUNDER AND PERIODS OF HEAVY RAIN SUNDAY AFTERNOON AND NIGHT. DESPITE THE RECENT DRY SPELL RAINFALL RATES MAY BE HIGH ENOUGH IN SPOTS TO CAUSE AT LEAST MINOR ISOLATED FLOODING WORRIES...AND THIS WILL BE ADDRESSED IN THE HWO. NAM AND ECMWF ARE SUGGESTING THAT THE WARM SECTOR WILL SURGE NORTH SUNDAY NIGHT WITH CAPES AOB 500 J/KG AND 35 TO 45 KNOTS OF 0-1KM BULK SHEAR AS FAR NORTH AS A BROOKHAVEN TO QUITMAN LINE. WILL NOT ADD ANYTHING TO THE HWO AT THE MOMENT...BUT TRENDS WILL NEED TO BE MONITORED CLOSELY./26/ LONG TERM...MONDAY THROUGH THE END OF NEXT WEEK...BIG COLD FRONT SHOULD BE RAPIDLY CLEARING EAST OF THE REGION MONDAY MORNING WITH POST FRONTAL RAIN SHOWERS TAILING OFF QUICKLY FROM WEST TO EAST IN THE MORNING AS WELL. FOR OUR REGION...CURRENT EXPECTATIONS ARE THAT COLD AIR BEHIND THE COLD FRONT WILL NOT BE COMING IN QUICKLY ENOUGH TO WORRY ABOUT ANY BRIEF CHANGEOVER TO FLURRIES BEFORE PRECIPITATION ENDS (EVEN IN MY NORTHERN ZONES). CLEARING SHOULD TAKE PLACE BY MONDAY AFTERNOON AT THE LATEST ALTHOUGH A GUSTY NORTHWEST WIND WILL BE VERY COLD AND BITING. EARLY SEASON MODIFYING ARCTIC AIR FUNNELING SOUTH INTO THE ARKLAMISS LATE MONDAY MIGHT NOT MODIFY AS MUCH AS USUALLY WOULD BE THE CASE OWING TO A LITTLE SNOWCOVER NOT TOO FAR UPSTREAM. THIS WILL LEND TO ANOTHER STRETCH OF UNSEASONABLY COLD CONDITIONS...ALTHOUGH FORTUNATELY WITH NOT QUITE THE STAYING POWER AS THE CURRENT STRETCH. LOWS EARLY TUESDAY MORNING MIGHT FLIRT WITH THE UPPER TEENS IN A FEW NORTHERN ZONES WHILE ALL OTHER AREAS SEE MINIMUMS IN THE 20S. SOME RETURN FLOW DEVELOPING IN WESTERN ZONES BY TUESDAY NIGHT MAY LIMIT RADIATIONAL COOLING THERE A BIT...BUT NOT ELSEWHERE WHERE LOWS WAY DOWN IN THE 20S LOOK A SOLID BET AGAIN. WE WILL START WARMING UP...ALBEIT NOT TERRIBLY QUICKLY...COME WEDNESDAY AS COLD HIGH PRESSURE SHUFFLES OFF TO THE EAST AND BUILDS SOUTH TO SOUTHWEST FLOW IN THE LOWER LEVELS. SUBTLE WAVES OF SOUTHERN STREAM ENERGY MAKING THEIR WAY HERE BY THURSDAY AND THROUGH THE REST OF THE WEEK WILL PROBABLY HAVE ENOUGH MOISTURE TO WORK WITH TO GENERATE AT LEAST A FEW SHOWERS. THERE IS STILL SOME POSSIBILITY OF A DECENT LOW SPINNING UP AND TRACKING TO OUR NORTHWEST SOMETIME NEXT WEEKEND ALTHOUGH MODEL CONSENSUS IN THIS POTENTIALLY STORMY DIRECTION IS NOT THE BEST. ADDING TO THE UNCERTAINTY AT THE END OF NEXT WEEK IS THE LATEST OPERATIONAL EURO RUN SUGGESTING ANOTHER DEEP ARCTIC INCURSION MAY PUT A SERIOUS HALT TO ANY WARMING TREND BY NEXT SATURDAY. ANY CONSENSUS TREND TOWARD THIS OUTLYING SOLUTION WOULD OF COURSE BE WATCHED CLOSELY. /BB/ && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
421 PM CST Sat Nov 15 2014 .DISCUSSION... Issued at 418 PM CST SAT NOV 15 2014 Tonight - Sunday: As today`s system which generated 2-4 inches of snow over the far northern counties exits the region our attention turns to three secondary areas of snow. An area of snow over Nebraska is tied to a shortwave trough moving east through western SD/NE. The trailing band of enhanced clouds/snow is expected to drag through the CWA overnight but only the far northwestern counties have a chance of more than a dusting...maybe 1/2" to and inch. The expected band of snow should diminish in intensity overnight but most areas will see at least intermittent flurries. The second region of snow is a result of the seeder-feeder mechanism as noted by the broken area of enhanced mid clouds which have formed from east central KS into west central MO. There likely is a weak mid-level vorticity max tied to this region of cloud and the NAM h7 prog seems to hint on this. Only the short-range HRRR has picked up on this. Could get a quick half inch of snow across the far southern CWA during the late afternoon/early evening hours before the feature weakens as it quickly heads east. The third area of snow is expected to form over the CO Rockies tonight and rapidly expand as a narrow band in response to the left front quad of an upper level jet streak races through the Central Rockies and into KS/OK Sunday morning. Operational models do depict one or two vorticity lobes tracking into the region within an overall area of ascent. At this time the northern edge of the expected snow band could skirt across our far southern counties so have added chance PoPs to this area. Otherwise, until the primary upper trough passes through late on Sunday am expecting mostly cloudy skies for most of the CWA. This will mute the diurnal temperature range. Monday - Tuesday: Much below average temperatures will continue during this period with the potential for a record low max temperature on Monday and record setting lows Tuesday morning. Another upper trough will dig southward Sunday night and Monday and result in falling mid/upper level heights and enhance the flow of Arctic air southward from the Canadian Plains to central U.S. Another surge of this air will move in during this period. Steep lapse rates below 750mb and a moist layer residing within the boundary layer suggests a good chance for instability snow showers or flurries Monday afternoon. Wednesday - Saturday: This should be a dry period with a continuation of the unseasonably cold regime. Cyclonic/northwest flow aloft will continue featuring the potential for weak embedded shortwaves to pass through. However, the airmass will be quite dry so it should remain dry. A slight moderation in temperatures are expected but they will remain about 15 degrees below average. A particularly cold air mass will swing into the Central Plains Monday into Tuesday. This will result in the coldest temperatures we have seen this fall with both Monday`s high temperatures and Tuesday morning`s low temperatures possibly setting new records. Here is a quick look at just some of those threatened temperature records. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1145 AM CST SAT NOV 15 2014 Band of heavier snow will affect far northwest and north central MO this afternoon with MVFR visibilities and cigs. The higher accumulating snows will miss the Kansas City terminals and graze KSTJ. For the terminals, after the initial light snow with MVFR visibilities/cigs moves through very early this afternoon expect cigs to improve into the low end VFR category for the rest of this afternoon and evening. Intermittent light snow or flurries expected through the night with only minor additional accumulations. Weak frontal passage from northwest to southeast starting in the pre-dawn hours. Could see several hours of MVFR cigs after frontal passage with these clouds clearing to the southeast by mid morning. && .CLIMATE... Issued at 418 PM CST SAT NOV 15 2014 Monday November 17th Current Record Low Forecast High Monday Record Low Highs High Afternoon -------------------------------------------------------------------- Kansas City 24 in 1891 22 St. Joseph 26 in 1951 22 Tuesday November 18th Current Record Low Forecast Low Tuesday Record Lows Morning -------------------------------------------------------------------- Kansas City 14 in 1903 7 St. Joseph 16 in 1989 5 && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...WINTER WEATHER ADVISORY until Midnight CST tonight FOR MOZ001>003-011. && $$ UPDATE...MJ DISCUSSION...MJ AVIATION...MJ CLIMATE...Cutter
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
351 PM CST Sat Nov 15 2014 .SHORT TERM: (Through Late Tonight) Issued at 347 PM CST Sat Nov 15 2014 Shortwave exiting the eastern Plains into the Mississippi Valley is producing a little bit of light snow and flurry activity across the CWFA today. Looks like the best snowfall has moved north of our CWFA across extreme northeast Missouri and southeast Iowa into west central Illinois. The broad scale mid level lift associated with the shortwave is lifting quickly northeast according to the RAP and NAM. Will likely see a little bit of lingering snowfall up there this evening, but any accumulations this evening should be well under an inch. Further south, HRRR and RAP have been very insistent that there will be a frontogenetical band of snow this evening somewhere between I-44 and I-70. The band will move northeast affecting parts of the STL metro area with some light snow. Simulated reflectivity off the 4km NCEP and NSSL WRF models also show this, and the operational NAM and GFS bear this out with a few hundredths of QPF. Latest radar mosaic shows a band of snow developing west central Missouri now...so this looks likely to happen. Have a band of likely PoPs this evening in to account for this snow, stretching across central Missouri into southwest Illinois to account for this. Carney .LONG TERM: (Sunday through Next Saturday) Issued at 347 PM CST Sat Nov 15 2014 (Sunday thru Tuesday) This period will continue to feature much below normal temps and another shot at accumulating snow. Models have come into better agreement with the system for Sunday/Sunday night. All guidance has shifted the forcing and subsequently the precip shield further north. Timing should be similar to today`s event. Precip is expected to begin across cntrl and SE MO around noon and then spread east thru the rest of the CWA during the aftn and then clear from W to E during the evng and be but a memory by midnight. The main p-type should be snow with temps aloft plenty cold enough to support ice crystal formation but...air temps above freezing at the beginning of the event may cause a rain/snow mix at the onset of the precip. I think the mix won`t last long as temps should wet bulb shortly after the precip begins. This will likely lead to a non-diurnal temp trend as temps fall across the sthrn CWA as the precip progresses east. Accum rates may be limited early on in the event for a variety of reasons beyond the warm air temps including...ground temps will likely be above freezing, snowfall rates may not be high enough and the aftn sun...even with the diminished angle...will have an effect. Event total snowfall amounts should be 1-2 inches along and south of I70. There may be a band of slightly enhanced snowfall along the I44 corridor that may reach upwards of 3 inches but not confident on band placement to include in the fcst attm. The system quickly lifts east after midnight. Monday looks like a raw day with potentially steady or slowly falling temps and a stiff NW wind as a 1030mb sfc high builds in. 850 temps fall from the negative single digits at 6Z Monday to the negative mid teens to near -20 by Monday evening. There is also an impressive short wave dropping down in the NW flow on Monday that should instigate at least occnl flurries with the possibility of actual snow showers...as was the case this past Thursday. Models hint at patchy QPF which would equate to a few tenths of an inch of snow...but will let later shifts asses that threat as it is still 2 days away. Tuesday should be the last truly cold day as the sfc ridge passes to the south. (Tuesday night thru Friday) The upper flow flattens thru the end of the week which will allow for a moderating trend. Winds will swing around to the south on the backside of the high Tuesday night. 850 temps near 0 and a Srly wind will boost temps to the upper 30s north to the upper 40s south on Wednesday. The next short waves pushes a cold front thru late in the day on Wednesday causing temps on Thursday and Friday to be a touch cooler. This front appears to be dry at this time. Models guidance diverges after this feature with the GFS building a strong sfc ridge into the Midwest for the end of the week while the ECMWF has another short wave and an attendant weak sfc low that tracks across sthrn MO/IL Thursday/Thursday night. Both models suggest another storm system for either the wknd and/or early next week as the next main short wave approaches in the mean flow. 2% && .AVIATION: (For the 18z TAFs through 18z Sunday Afternoon) Issued at 1204 PM CST Sat Nov 15 2014 Upper level disturbance moving out of eastern Kansas into Missouri is producing snow over northern/northwestern portions of the state. Some trailing precipitation to the south will overspread the area this afternoon, but due to very dry low levels, it will take a while to make it to the ground. Think best chances of snow this afternoon will be across northern portions of the CWFA in northeast Missouri and west central Illinois, tho some light snow is also likely further south. Another band of snow will likely form between I-44 and I-70 across Missouri and move northeast this evening impacting east central Missouri into southwest Illinois. VFR flight conditions should prevail outside of some of the heavier snow showers this afternoon and the bands across northern Missouri this afternoon, and the second band in east central Missouri and southwest Illinois. Flight conditions could drop to IFR in these areas, but MVFR vsbys/ceilings are most likely. After the southern band moves out this evening, VFR flight conditions are expected through Sunday morning. Specifics for KSTL: Expect VFR flight conditions to prevail for most of the afternoon. Precipitation west of the terminal associated with an upper level disturbance will most likely evaporate before hitting the ground, but another band of snow is expected to develop between I-44 and I-70 across Missouri and move northeast this evening impacting east central Missouri into southwest Illinois. The exact position of the band will determine how heavy the snow will get at Lambert, but the band should be fairly narrow and short-lived. While there is a chance for IFR conditions with the band, think the most likely impact will be MVFR visibility for a short period this evening. VFR flight conditions are expected to prevail after the band clears the region by mid-evening. There is another chance of snow Sunday afternoon...but have left mention out for now to focus on the short-range forecast. Carney && .CLIMATE: Issued at 748 PM CST Thu Nov 13 2014 The following are record low maximums and record low minimums for each of the next 5 days, which corresponds to the expected length of the current cold spell and record snowfall for St. Louis and Columbia for Saturday and Sunday when the area is expecting the first widespread accumulating snowfall of the season. Date: 11/15 11/16 11/17 11/18 St. Louis Low High: 29/1940 29/1997 17/1880 25/1880 Low: 11/1940 13/1959 6/1959 14/1932 Snowfall: 0.1/1997 1.0/1951 Columbia Low High: 28/1940 30/1932 23/1959 27/1903 Low: 6/1940 8/1959 4/1959 8/1891 Snowfall: 4.8/1932 0.1/1989 Quincy Low High: 29/1940 28/1997 19/1959 24/1903 Low: 7/1940 4/1959 3/1959 7/1903 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
337 PM CST SAT NOV 15 2014 .SHORT TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 331 PM CST SAT NOV 15 2014 ENDING SNOW TONIGHT...THEN COLD TEMPERATURES THE NEXT FEW DAYS...ARE THE PRIMARY FORECAST CONCERNS. FIRST ROUND OF SNOW TIED TO SOUTHERN SHORTWAVE/WARM ADVECTION PATTERN MOVED EAST/NORTHEAST OF THE CWA BY EARLY AFTERNOON. THIS AREA DROPPED AN INCH OR TWO OF SNOW ACROSS THE SOUTHERN HALF OF THE CWA. ANOTHER AREA OF SNOW WAS ENTERED THE WESTERN PART OF NORTHEAST NEBRASKA EARLY IN THE AFTERNOON. THIS WAS TIED TO STRONGER UPPER LOW/TROUGH SWINGING THROUGH WESTERN SOUTH DAKOTA. 75KT MID LEVEL JET WAS ROUNDING BASE OF THIS FEATURE...INCREASING LIFT IN NORTHEAST WHERE SECOND ROUND OF SNOW WAS FALLING THIS AFTERNOON. CHARACTER OF RADAR RETURNS SUGGEST THIS AREA WILL PRODUCE LIGHT SNOW FOR THE MOST PART...WITH A FEW ROUNDS OF MODERATE SNOW FROM TIME TO TIME. PROGRESSIVE NATURE ALSO SUGGESTS MESOSCALE MODEL FORECASTS FROM HRRR AND RAP IN SHOWING SNOW AFFECTING MAINLY THE NORTHERN HALF OF THE CWA AND WINDING DOWN BY MIDNIGHT STILL LOOKS GOOD. ADDITIONAL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THE NORTHERN TWO-THIRDS OF THE CWA TAPERING TO LESS THAN AN INCH TOWARD THE KANSAS BORDER. BACK EDGE OF SNOW WILL ALSO COINCIDE WITH COLD FRONT SWEEPING ACROSS THE PLAINS. FRONT WILL PASS NORFOLK BY 9 PM AND BE APPROACHING OMAHA BY MIDNIGHT. GUSTY NORTHWEST WINDS OF 15 TO 25 MPH SHOULD FOLLOW...CAUSING A LITTLE BLOWING AND DRIFTING OF SNOW OVERNIGHT BEFORE WINDS BEGIN TO SUBSIDE SOME ON SUNDAY. CLEARING SKIES AFTER MIDNIGHT...COLD AIRMASS AND FRESH SNOW COVER WILL LEAD TO COLD TEMPERATURES BY MORNING...WITH WINDS ONLY THING KEEPING LOWS FROM BOTTOMING OUT. SINGLE DIGITS ARE FORECAST MOST EVERYWHERE. SUNDAY WILL BRING SUNSHINE AND SOUTHWEST FLOW AHEAD OF A REINFORCING COLD FRONT SLATED TO ARRIVE INTO NORTHEAST NEBRASKA IN THE AFTERNOON...THEN THROUGH THE REST OF THE AREA DURING THE EVENING. SNOW COVER WILL KEEP TEMPS FROM REACHING MAXIMUM POTENTIAL SUNDAY AFTERNOON...WITH LOWER 20S EXPECTED MOST AREAS. MORE GUSTY NORTHWEST WINDS WILL ACCOMPANY COLD FRONT AND SHOULD CONTINUE ALL NIGHT. EXTREMELY COLD AIRMASS FOLLOWS THE FRONT WITH MODELS SHOWING -20 850 TEMPERATURES INTO OUR NORTHERN CWA BY 12Z MONDAY. THIS WILL TRANSLATE TO LOWS AGAIN IN THE SINGLE DIGITS WITH HIGHS REBOUNDING ONLY BACK INTO THE TEENS MONDAY AFTERNOON. WIND CHILLS MONDAY MORNING WILL LIKELY FALL TO 15 BELOW OR COLDER FOR MUCH OF THE NORTHERN HALF OF THE CWA. DECREASING WINDS AND CLEARING SKIES SUGGEST TUESDAY MORNING MAY BE THE COLDEST OF THIS RECENT COLD SPELL. LOWS NEAR ZERO ARE LIKELY ACROSS ALL OF EASTERN NEBRASKA AND SOUTHWEST IOWA...WITH SUB-ZERO TEMPS NEARLY A CERTAINTY IN OUR NORTH. SOUTHWEST FLOW RETURNS FOR TUESDAY...HELPING TO WARM TEMPS BACK INTO THE MID 20S IN THE AFTERNOON. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 331 PM CST SAT NOV 15 2014 SLOWLY MODERATING TEMPERATURES APPEAR TO BE THE MAIN STORY IN THE LONGER TERM PERIOD. ANOTHER SHORTWAVE IS SHOWN BY GFS/ECMWF SLAMMING THROUGH MINNESOTA AND IOWA TUESDAY NIGHT...BRINGING ANOTHER SHOT OF COLDER AIR INTO THE PLAINS THROUGH WEDNESDAY. HOWEVER THIS WILL NOT BE NEARLY AS COLD AS EARLIER IN THE WEEK WITH HIGHS WEDNESDAY INTO THE 20S AND LOWER 30S. MID LEVEL HEIGHTS BEGIN A SLOW RISE FOR THE REST OF THE WEEK AS FLOW BECOMES MORE ZONAL BEHIND TUESDAY NIGHT SHORTWAVE. ANOTHER SHOT OF SOMEWHAT COOLER AIR IS EXPECTED THURSDAY...BUT THAT LOOKS SHORT-LIVED. HAVE HIGHS REBOUNDING BACK INTO THE 30S FRIDAY AND SATURDAY. OTHERWISE A DRY FORECAST REMAINS INTACT. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1209 PM CST SAT NOV 15 2014 MAIN BAND OF MODERATE TO HEAVY SNOW ABOUT TO MOVE ACROSS KOMA AT THE START OF THE PERIOD. ONCE THIS AREA MOVES TO THE EAST EXPECT PRIMARILY MVFR CIGS AND VSBY AT ALL THREE SITES WITH OCCASIONAL IFR CONDITIONS THROUGH ABOUT 02Z IN ADVANCE AND JUST BEHIND THE COLD FRONT MOVING INTO CENTRAL NEBRASKA AT 18Z. VFR CONDITIONS ARE EXPECTED TO DEVELOP AFTER 12Z AS FRONT MOVES FURTHER EAST AND HIGH PRESSURE BUILDS INTO THE AREA AHEAD OF NEXT COLD FRONT. THIS SECOND COLD FRONT WILL BE MOVING INTO THE AREA JUST AFTER THE END OF THE FORECAST PERIOD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NEZ011- 012-015>018-030>034-042>045-050>053-065>068-078. IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ043- 055-056-069-079-080-090-091. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
334 PM EST SAT NOV 15 2014 .SYNOPSIS...HIGH PRESSURE CENTERED OVER THE REGION THIS AFTERNOON WILL GRADUALLY SHIFT OFFSHORE TONIGHT AND SUNDAY. A DEVELOPING LOW PRESSURE SYSTEM ATTENDANT AN AMPLIFYING UPPER LEVEL TROUGH WILL INTENSIFY IN VICINITY OF THE LOUISIANA GULF COAST ON SUNDAY...THEN TRACK NORTHEAST ALONG THE SPINE OF THE APPALACHIANS SUNDAY NIGHT INTO MONDAY. AN ASSOCIATED COLD FRONT WILL SWEEP EASTWARD THROUGH THE CAROLINAS MONDAY AFTERNOON AND EVENING. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM SATURDAY... TODAY: MODIFIED ARCTIC HIGH PRESSURE CENTERED OVER THE REGION WILL ENSURE THAT DRY CONDITIONS AND LIGHT/VARIABLE WINDS PREVAIL THROUGH TONIGHT. THE LOW-LEVEL CORE OF THE MODIFIED ARCTIC AIRMASS WAS ANALYZED DIRECTLY OVER CENTRAL NC AND EASTERN VA THIS AFTERNOON (18Z)...CHARACTERIZED BY 925 MB TEMPS IN VICINITY OF -2C. PWAT VALUES BOTTOMED OUT AT A `FINGER-CRACKING` 0.14 INCHES ON THE GSO RAOB 00Z YESTERDAY. 18Z MESOANALYSIS AND RAP DATA INDICATE MID/UPPER LEVEL MOISTURE HAS STEADILY INCREASED SINCE 00Z...THOUGH LITTLE EVIDENCE THEREOF (I.E. CIRRUS) CAN BE IDENTIFIED VIA SATELLITE IMAGERY. GIVEN CLEAR SKIES AND MARGINAL LOW-LEVEL MODIFICATION IN COMPARISON TO YESTERDAY...EXPECT HIGHS SIMILAR ALBEIT SLIGHTLY WARMER THAN YESTERDAY...IN THE LOWER/MID 40S. TONIGHT: MODIFIED ARCTIC HIGH PRESSURE CENTERED OVER THE MID- ATLANTIC THIS EVENING WILL SHIFT OFFSHORE THE MID-ATLANTIC COAST LATE TONIGHT...IN ADVANCE OF SHORTWAVE ENERGY TRACKING EASTWARD FROM THE DAKOTAS TO THE UPPER GREAT LAKES. MEANWHILE...UPSTREAM PRECIP IS EXPECTED TO BLOSSOM ACROSS THE LOWER MS RIVER VALLEY AFTER MIDNIGHT AS SHORTWAVE ENERGY DIGS SSE FROM THE PACIFIC NW TO THE COLORADO FRONT RANGE. ASIDE FROM AN INCREASING LIKELIHOOD OF CIRRUS ADVECTING INTO THE REGION VIA WSW FLOW ALOFT...FAVORABLE RADIATIONAL COOLING CONDITIONS WILL OTHERWISE PREVAIL. DUE TO AIRMASS MODIFICATION ASSOC/W THE ONSET OF A LIGHT SOUTHERLY/SW RETURN FLOW...ANTICIPATE LOWS A FEW DEGREES WARMER THAN THIS MORNING...IN THE MID TO UPPER 20S. -VINCENT && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 315 PM SATURDAY... SUN/SUN NIGHT: CHALLENGING TEMPERATURE AND PRECIP FORECAST. THE ONSET OF WARM ADVECTION...I.E. SOUTHERLY RETURN FLOW EMANATING FROM THE ATLANTIC /GULF STREAM/...WILL RESULT IN INCREASING CLOUD COVER AND THE DEVELOPMENT OF A HYBRID OR IN-SITU COLD AIR DAMMING WEDGE. ELEVATED SHOWER ACTIVITY WILL BE POSSIBLE SUNDAY EVE/NIGHT AS LOW- LEVEL WARM ADVECTION FURTHER STRENGTHENS ATOP THE SHALLOW COLD AIR DAMMING WEDGE IN ADVANCE OF A WARM FRONT LIFTING NORTHWARD THROUGH CENTRAL/EASTERN NC. GIVEN THE EXPECTATION OF BROKEN/OVERCAST CEILINGS AT LOWER (STRATUS) AND UPPER (CIRRUS) LEVELS...EVAP COOLING ASSOCIATED WITH AN INITIALLY DRY SURFACE AIRMASS ALONG WITH VIRGA AND AN INCREASING POTENTIAL FOR ELEVATED SHOWERS...EXPECT CHILLY AFTERNOON TEMPERATURES RANGING FROM THE UPPER 30S TO MID 40S (NW) TO MID 40S/LOWER 50S IN THE SE COASTAL PLAIN. EXPECT TEMPERATURES TO RISE OVERNIGHT FROM SOUTH TO NORTH AS THE LOW-LEVELS SATURATE AND A WARM FRONT LIFTS NORTHWARD THROUGH CENTRAL/EASTERN NC. TEMPS IN THE TRIAD MAY HOLD STEADY FOR MUCH OF THE NIGHT...THOUGH A SLOW RISE STILL APPEARS LIKELY BY SUNRISE. -VINCENT MONDAY THROUGH MONDAY NIGHT...UPPER TROF ROTATING ACROSS THE UPPER MIDWEST INTO THE GREAT LAKES WILL PUSH THE STRONG COLD FRONT EAST ACROSS THE AREA. AMPLITUDE OF THE SYSTEM WILL PROVIDE A DEEP SOUTHWEST TAP INTO THE GULF AHEAD OF THE FRONT...WITH A PLUME OF PRECIPITABLE WATER OF 1.5 INCHES EDGING INTO CENTRAL AND EASTERN NORTH CAROLINA BY AFTERNOON COURTESY OF A 50+ KNOT LOW LEVEL JET AT H850 STRAIGHT OFF THE GULF. TIMING DISCREPANCIES ARE MINOR CONCERNING SENSIBLE WEATHER AND WILL MAINTAIN OUR ONGOING CATEGORICAL POPS IN THE WEST IN THE MORNING PROGRESSING EAST TO THE I-95 CORRIDOR DURING THE AFTERNOON. SOUTHERLY WINDS AT 10-15 MPH GUSTING TO 20 WILL VEER SOUTHWEST TO WEST DURING THE AFTERNOON AND NORTHWEST OVERNIGHT. HIGHS IN THE EAST WILL HAVE AMPLE TIME TO REACH NEAR 70 PRIOR TO THE FRONT WHICH PROGS TO A COUPLE OF HUNDRED JOULES OF CAPE. VERTICAL ALIGNMENT OF THE DEPARTING 150KT UPPER JETS DIFFLUENCE AND PERTURBATIONS IN THE MID LEVEL FLOW WOULD AID CONVECTIVE DEVELOPMENT AND WILL EXPAND MENTION OF THUNDER WEST ACROSS THE TRIANGLE AND SANDHILLS. TEMPERATURES IN THE NORTHWEST ARE A LITTLE MORE UNCERTAIN DUE TO POTENTIAL FOR IN-SITU LINGERING COOL AIR DUE TO EVAPORATIVE COOLING SUNDAY NIGHT. THIS WOULD BLOCK THE TRANSITION TO A MORE PLEASANT SOUTHERLY SURFACE FLOW AND HIGHS WOULD STRUGGLE TO REACH MID 50S. THE FRONT WILL BE MOVING SMARTLY ALONG...WITH SHOWERS ENDING AND CLEARING COMMENCING TOWARDS SUNSET IN THE WEST TO AROUND MIDNIGHT IN THE EAST. TEMPS WILL PLUMMET AS COLD AIR RUSHES IN AND THICKNESSES CRASH OVERNIGHT...MONDAY NIGHTS MINS LOOK TO FALL BELOW FREEZING OVER THE PIEDMONT...WITH MID 30S IN THE EASTERN THIRD OF THE AREA. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 300 PM SATURDAY... A COLD STRETCH IS ON TAP BEHIND THE FRONT AS POLAR AIR PAYS THE AREA A VISIT TUESDAY AND WEDNESDAY. THE INITIAL SURGE WILL BE BRISK AND RAW ON TUESDAY...FEATURING NORTHWEST WIND GUSTING TO 20 MPH AND THICKNESSES BARELY INDICATIVE OF MID 30S OVER THE NORTHWEST TO LOWER 40S SOUTHEAST. SURFACE HIGH SETTLING OVER THE AREA AND LOOSENING PRESSURE GRADIENT WILL BE IDEAL FOR RADIATIONAL COOLING AND MINS WILL BE COLDEST WEDNESDAY MORNING...WITH MOST AREAS WITHIN A COUPLE OF DEGREES OF 20. SLIGHT DEAMPLIFICATION OF THE TROF AND ANOTHER DAY OF STRONG INSOLATION WILL PROVIDE SOME VERY MODEST WARMING ON WEDNESDAY...WITH HIGHS FROM 40 TO 45. FORECAST FOR LATE WEEK IS MORE UNCERTAIN AS THERE IS MODEL UNCERTAINTY IN THE SUBSEQUENT EVOLUTION OF THE UPPER TROF AND STRONGER INDICATIONS OF A SURFACE SYSTEM DEVELOPING AND SKIRTING THE AREA ON FRIDAY IN THE ECMWF. REGARDLESS...TEMPS WILL MODERATE IN THE THURSDAY THROUGH SATURDAY TIME FRAME AS THE TROF DEAMPLIFIES AND HIGHS EACH DAY LOOK TO BE IN THE LOW TO MID 50S...MAYBE A LITTLE WARMER ON THE WEEKEND AS WE SIT UNDER A STRONG HIGH AND TRANSITION BRIEFLY TO A LOW AMPLITUDE UPPER RIDGE. AT THIS POINT AM THINKING ONLY HIGH CLOUDINESS IN THE FASTER FLATTER FLOW AND WILL HAVE ONLY SLIGHT CHANCE POPS FOR THE FRIDAY NIGHT INTO SATURDAY TIME FRAME. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 100 PM SATURDAY... 24-HR TAF PERIOD: VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL THROUGH TONIGHT AT ALL TERMINALS AS HIGH PRESSURE CENTERED OVER THE REGION GRADUALLY BEGINS TO SHIFT OFFSHORE. SUB-VFR CEILINGS WILL BE POSSIBLE AT ALL TERMINALS BY THE END OF THE TAF PERIOD (12-18Z SUN) IN ASSOCIATION WITH THE ONSET OF WARM ADVECTION AS THE SFC HIGH MOVES FURTHER OFFSHORE AND A WARM/MOIST AIRMASS ADVECTS INTO THE CAROLINAS FROM THE ATLANTIC. LOOKING AHEAD: AN EXTENDED PERIOD OF ADVERSE AVIATION CONDITIONS IS EXPECTED SUNDAY AFT/EVE INTO SUN NIGHT IN ASSOC/W WARM ADVECTION ATOP A SHALLOW COLD AIR DAMMING WEDGE IN ADVANCE OF A POTENT COLD FRONT APPROACHING THE MOUNTAINS FROM THE WEST. THE COLD FRONT WILL SWEEP EASTWARD THROUGH THE REGION LATE MONDAY AFTERNOON. BREEZY NORTHWEST WINDS WILL OCCUR IN THE WAKE OF THE FRONT MONDAY NIGHT INTO TUESDAY AS ANOTHER ARCTIC HIGH BUILDS INTO THE REGION FROM THE WEST. -VINCENT && THE FOLLOWING ARE RECORD TEMPERATURES THAT WILL BE CHALLENGED THROUGH THE FORECAST PERIOD: RECORD LOW: GSO RDU FAY WED 11/19 - 20 IN 1951 21 IN 1903 21 IN 1959 THU 11/20 - 12 IN 1951 19 IN 1951 20 IN 1951 RECORD LOW MAX: GSO RDU FAY TUE 11/18 - 37 IN 1924 35 IN 1924 46 IN 2008 WED 11/19 - 34 IN 1951 36 IN 1951 41 IN 2000 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...VINCENT LONG TERM...MONEYPENNY AVIATION...VINCENT CLIMATE...MWS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1219 PM CST SAT NOV 15 2014 .UPDATE... ISSUED AT 1220 PM CST SAT NOV 15 2014 CONTINUED TO EXPAND ISOLATED FLURRIES SOUTHEAST AS THE STRATUS DECK WITH EMBEDDED FLURRIES CONTINUES TO DRIFT SOUTH OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. FOCUS THEN SHIFTS TO WINDS AND BLOWING SNOW POTENTIAL SUNDAY. WILL CONTINUE TO COLLABORATE WITH SURROUNDING OFFICES TO ENSURE CONSISTENT HEADLINES. WILL HAVE HEADLINE DECISIONS REACHED BY THE MID-AFTERNOON UPDATE TIME. UPDATE ISSUED AT 839 AM CST SAT NOV 15 2014 UPDATED THE FORECAST TO CANCEL THE WIND CHILL ADVISORY FOR WEST CENTRAL AND NORTHWESTERN NORTH DAKOTA THIS MORNING. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A STRATUS DECK BEGINNING TO DRIFT SOUTH ACROSS NORTHWESTERN NORTH DAKOTA. ISOLATED FLURRIES HAVE BEEN REPORTED UNDER THIS STATUS DECK. AS A RESULT...ADDED ISOLATED FLURRIES TO THE FORECAST NORTHWEST THIS MORNING. THE STRATUS SHOULD BEGIN TO BREAK UP SOMEWHAT BY THIS AFTERNOON. THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 653 AM CST SAT NOV 15 2014 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC. WILL LEAVE THE WIND CHILL ADVISORY IN PLACE AS BORDERLINE ADVISORY CRITERIA VALUES NEAR -25 WILL CONTINUE EARLY THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 406 AM CST SAT NOV 15 2014 MAIN HIGHLIGHT THIS MORNING IS A WIND CHILL ADVISORY FOR PORTIONS OF THE FAR WEST. COLDER AIR COMING IN FROM THE WEST AND BRISK WINDS WILL DOMINATE THROUGH MID MORNING. A POTENT SHORTWAVE AND ASSOCIATED COLD FRONT SHIFTING SOUTH FROM CENTRAL CANADA WILL BEGIN TO IMPACT WESTERN/NORTHERN NORTH DAKOTA LATE SATURDAY NIGHT THEN SPREAD SOUTH SUNDAY MORNING. THE LATEST WATER VAPOR IMAGERY SHOWS AN ELONGATED UPPER TROUGH FROM HUDSON BAY SOUTHWEST INTO MONTANA. AHEAD OF THE TROUGH...A SHORTWAVE WAS SEEN ALONG THE WYOMING/MONTANA BORDER MOVING EAST TO SOUTHEAST WITH TIME...AS THE SURFACE LOW REMAINS FARTHER SOUTH. LIGHT SNOW ASSOCIATED WITH THIS SYSTEM EXTENDED ACROSS CENTRAL AND SOUTHERN SOUTH DAKOTA AND IS MOVING EAST. FARTHER UPSTREAM...AN AREA OF STRATUS OVER SOUTHERN SASKATCHEWAN PER LATEST FOG/STRATUS LOOP CONTINUES A SOUTHEAST MOVEMENT. THE HRRR AND RAP13 SHIFT THIS INTO NORTHWEST AND NORTH CENTRAL NORTH DAKOTA BETWEEN 12Z-21Z TODAY. CONCUR WITH THIS AND ADJUSTED SKY GRIDS ACCORDINGLY. ELSEWHERE ISOLATED FLURRIES WITH POCKETS OF STRATUS CONTINUE EARLY THIS MORNING IN THE FAR SOUTHWEST...ALONG AND SOUTH OF LAKE SAKAKAWEA...AND IN THE SOUTHERN JAMES RIVER VALLEY. ANOTHER VERY COLD DAY AHEAD WITH HIGHS IN THE SINGLE DIGITS ABOVE ZERO IN THE WEST AND SOUTHWEST...TO LOWER/MIDDLE TEENS ELSEWHERE. BRISK NORTHWEST WINDS THIS AFTERNOON 10 TO 25 MPH. FOR TONIGHT...ATTENTION TURNS TO A STRONG SHORTWAVE TROUGH AND ASSOCIATED SHARP COLD FRONT HEADING DUE SOUTH FROM THE NORTHWEST TERRITORIES. THE COLD FRONT WILL PASS THROUGH NORTHWEST AND NORTH CENTRAL AFTER MIDNIGHT WITH INCREASING WINDS TOWARD AND SHORTLY AFTER DAYBREAK ON SUNDAY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 406 AM CST SAT NOV 15 2014 BLOWING SNOW POTENTIAL ON SUNDAY HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE CONTINUES THE TREND OVER THE PAST SEVERAL DAYS OF A REINFORCING COLD FRONT TO PROPAGATE ACROSS WESTERN AND CENTRAL NORTH DAKOTA SUNDAY MORNING IN ASSOCIATION WITH ITS PARENT CLIPPER SYSTEM ACROSS EASTERN MANITOBA INTO WESTERN ONTARIO. STRONG NORTHWEST WINDS INTERACTING WITH THE SNOWFALL FROM LAST WEEKEND PRESENTS A BLOWING SNOW THREAT. THE CHALLENGE IS IF BLIZZARD CRITERIA WILL BE MET ACROSS THE SOUTHWEST WHERE THE MOST SNOW WAS RECEIVED. THE SNOW HAS BEEN ON THE GROUND FOR A WEEK...HOWEVER...IT IS UNCRUSTED AND HAS NOT BEEN SIGNIFICANTLY COMPACTED. THAT SAID....BEING THE FIRST SNOWFALL OF THE SEASON...SOME OF THE SNOW MAY BE ADVERSE TO BEING LOFTED FROM BEING TRAPPED IN THE GRASSES. THUS...WILL FORGO A BLIZZARD WATCH FOR NOW...AND HIGHLIGHT THE THREAT WITH NEAR-BLIZZARD CONDITIONS POSSIBLE IN THE REMAINDER OF THE PRODUCT SUITE AND SPECIAL WEATHER STATEMENT. PROBABILITIES FOR HALF-MILE VISIBILITIES USING THE BAGGALY BLOWING SNOW MODEL TAKING INTO ACCOUNT SNOW AGE AND THE LACK OF SIGNIFICANT FALLING SNOW PRODUCE RESULTS THAT DO NOT FAVOR BLIZZARD CRITERIA BEING MET. FURTHERMORE...THE STRENGTH OF ISALLOBARIC FORCING AND WINDS AT THE TOP OF THE MIXED LAYER DECREASE THROUGH THE DAY...BEING GREATEST PRIOR TO THE PRE-FRONTAL INVERSION BEING BROKEN. CERTAINLY AT LEAST A WINTER WEATHER ADVISORY FOR BLOWING SNOW WILL BE NEEDED FOR THE SOUTHWEST...AND POSSIBLY INTO THE SOUTH CENTRAL. GIVEN FURTHER EVALUATION TODAY.... WOULD NOT BE SURPRISED IF A BLIZZARD WATCH IS ISSUED. THEREAFTER...THE DE-AMPLIFICATION OF THE ANOMALOUS UPPER LEVEL PATTERN IS SLOWER WITH THE 15/00 UTC GUIDANCE CONSENSUS COMPARED TO PREVIOUS RUNS...WITH A RECOVERY FROM ARCTIC AIR LIKELY DELAYED UNTIL LATE NEXT WEEK AT THE EARLIEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1220 PM CST SAT NOV 15 2014 MVFR CIGS WILL CONTINUE TO DRIFT SOUTH OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. ISOLATED FLURRIES ARE EMBEDDED WITHIN THE STRATUS DECK. INDICATED VCSH IN THE AFTERNOON TAFS TO ACCOUNT FOR THESE FLURRIES. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO DEVELOP OVERNIGHT. A COLD FRONT WILL THEN SWEEP ACROSS THE STATE FROM NORTH TO SOUTH SUNDAY MORNING...WITH WINDY CONDITIONS DEVELOPING IN ITS WAKE SUNDAY AFTERNOON. BLOWING SNOW WILL BE POSSIBLE MAINLY OVER KDIK SUNDAY...WITH IFR VSBYS EXPECTED. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...KS LONG TERM...AYD AVIATION...TM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1126 AM CST SAT NOV 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 415 AM CST SAT NOV 15 2014 FOCUS ON THE SNOW EVENT CURRENTLY UNDERWAY ACROSS OUR WESTERN CWA... EXPECTED TO PROGRESS EAST THROUGH THE REGION OVER THE NEXT 24 HOURS. OVERALL LOOKING AT A BROAD ISENTROPIC UPGLIDE AHEAD OF OPEN WAVE...WHICH SHOULD RESULT IN FAIRLY UNIFORM SNOW AMOUNTS ACROSS THE REGION. HOWEVER...CURRENT RADAR SHOWING A COUPLE MORE DISTINCT BANDS NEAR MID LEVEL /750-650MB/ FRONTAL BOUNDARIES PER RAP MODEL...SO COULD SEE SOME AREAS OF ENHANCEMENT THROUGHOUT THE DAY. FRONTOGENESIS APPEARS TO BE FAIRLY TRANSIENT THOUGH...SO DO NOT EXPECT HEAVIER BANDS TO SIT IN ANY ONE LOCATION FOR PROLONGED PERIOD OF TIME. NORTHERN BAND APPEARS TO BE A LITTLE FARTHER NORTH THAN PREVIOUSLY EXPECTED THOUGH...AIMING TOWARD THE HIGHWAY 14 CORRIDOR THROUGH THE MORNING. HAVE BUMPED UP SNOW AMOUNTS A BIT IN THESE AREAS AS A RESULT...AND EXPANDED ADVISORY NORTHWARD TO COVER ENTIRE CWA FOR WIDESPREAD 3 TO 5 INCHES. IN ADDITION TO POTENTIALLY HIGHER BANDS...CONCERN FOR THIS EVENT IS HIGH SNOW RATIOS GIVEN STRONG LIFT WITHIN DEEP DENDRITIC LAYER... AND LIGHT WINDS ALLOWING DENDRITIC SNOW FLAKES TO HOLD TOGETHER. GENERALLY STICKING WITH 16-18:1 RATIOS FOR BULK OF THE SNOWFALL... BUT SOME MODELS INDICATE A BIT HIGHER...WHICH COULD PUSH AMOUNTS CLOSER TO 6 INCH RANGE IN SOME AREAS. STILL EXPECT SNOW TO BE DONE IN MOST AREAS BY MID-LATE EVENING...BUT WAVE IS A BIT SLOWER IN DEPARTING THIS EVENING...SO EXTENDED ADVISORY TIMING IN OUR FAR EAST THROUGH MIDNIGHT TONIGHT. GIVEN FLUFFY NATURE OF SNOWFALL... COULD SEE A LITTLE BLOWING/DRIFTING OF FRESH SNOW AS NORTHWEST WINDS PICK UP BEHIND THE FRONT ACROSS OUR SOUTHWEST AREAS THIS AFTERNOON AND EVENING...AND WILL CONTINUE MENTION OF PATCHY BLOWING SNOW THROUGH PARTS OF THE MISSOURI RIVER VALLEY. STRONGER WINDS OCCUR AFTER BULK OF ACCUMULATION IS OVER THOUGH...SO AT THIS TIME HAVE NOT EXTENDED HEADLINES TO COVER ANY BLOWING SNOW THREAT. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 415 AM CST SAT NOV 15 2014 ON SUNDAY...INTENSIFYING LOW PRESSURE TRACKING THROUGH THE UPPER MISSISSIPPI VALLEY/WESTERN GREAT LAKES REGION WILL PULL A COLD FRONT THROUGH OUR AREA IN THE AFTERNOON. WHILE WINDS WILL INITIALLY BE OUT OF THE WEST/SOUTHWEST EARLY IN THE DAY...THEY WILL TURN AROUND TO THE NORTHWEST WITH THE PASSAGE OF THE SYSTEM...AND PICK UP IN A COLD AIR ADVECTION REGIME. WITH THIS...GUSTS WILL RAMP UP TO 20 TO 30 KTS ACROSS THE AREA. IN RESPONSE TO THIS...WILL BEGIN TO HAVE AREAS OF BLOWING SNOW WITH FRESH SNOW COVER ON THE GROUND. WILL ALSO SEE THE POSSIBILITY OF SCATTERED FLURRIES OVER PORTIONS OF THE AREA WITH SOME CLOUD COVER AND VERY COLD THERMAL PROFILES SUPPORTIVE OF DENDRITIC GROWTH. IN A THE WEST/SOUTHWESTERLY FLOW OUT AHEAD OF THE FRONT...THE MISSOURI RIVER VALLEY WILL HAVE THE OPPORTUNITY TO WARM INTO THE MID 20S BEFORE BEGINNING TO DROP OFF IN THE AFTERNOON AS THE COLDER AIR FEEDS INTO THE AREA. BACK TO THE NORTH AND EAST...HIGHS WILL ONLY MAKE IT INTO THE UPPER TEENS TO LOWER 20S. STRONG GUSTY NORTHWESTERLY WINDS WILL PERSIST FOR SUNDAY NIGHT AND MONDAY...KEEPING THE POSSIBILITY OF BLOWING SNOW ACROSS THE AREA THROUGH THE PERIOD. THE WINDS WILL KEEP TEMPERATURES FROM DROPPING OFF TOO DRAMATICALLY ON SUNDAY NIGHT...THOUGH STILL COLD WITH LOWS IN THE SINGLE DIGITS. IN AN INCREASINGLY COLD AIRMASS WITH MONDAY 925 MB TEMPERATURES PROGGED TO BE JUST EITHER SIDE OF -15 C...IT WILL BE A BITTERLY COLD DAY WITH HIGHS IN THE LOWER TO MID TEENS. WITH THE AFOREMENTIONED WINDS...WIND CHILLS WILL BE FIERCE...RUNNING IN THE SINGLE DIGITS BELOW ZERO TO TEENS BELOW ZERO. WINDS WILL THEN RAMP DOWN ON MONDAY NIGHT AS A SURFACE RIDGE AXIS SLIDES CLOSER TO THE AREA...BRINGING AN END TO ANY BLOWING SNOW. STILL ENOUGH WIND HOWEVER TO KEEP OVERNIGHT LOWS SOMEWHAT IN CHECK...BOTTOMING OUT JUST EITHER SIDE OF ZERO. FOR THE REMINDER OF NEXT WEEK...THERE WILL BE A SLIGHT MODERATION OF TEMPERATURES...ALBEIT STILL MUCH BELOW NORMAL...IN A NORTHWESTERLY UPPER LEVEL FLOW. THIS WOULD BE MOST APPARENT TOWARD THE END OF THE WEEK WHEN HIGHS ON FRIDAY COULD CLOSE IN ON THE LOWER 30S THROUGH THE MISSOURI RIVER VALLEY. THERE DOES NOT APPEAR TO BE ANY SIGNIFICANT PRECIPITATION PRODUCERS THROUGH THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1124 AM CST SAT NOV 15 2014 MVFR TO OCCASIONAL IFR CONDITIONS IN SNOW TODAY...WITH CONDITIONS GRADUALLY IMPROVING THE THE OVERNIGHT HOURS. WHILE MAINLY VFR CONDITIONS ARE EXPECTED AFTER ABOUT 9Z TONIGHT IN MOST LOCATIONS SOME PATCHY MVFR CEILINGS WILL BE POSSIBLE TOMORROW. BE PREPARED FOR VERY STRONG WINDS AND REDUCED VISIBIITY IN BLOWING SNOW SUNDAY NIGHT INTO MONDAY AFTERNOON. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR SDZ039- 040-054>056-060>062-065>071. WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR SDZ038- 050-052-053-057>059-063-064. MN...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ071- 072-080-089-097-098. WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ081- 090. IA...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR IAZ001- 012-020-031. WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ002- 003-013-014-021-022-032. NE...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NEZ013- 014. && $$ SHORT TERM...JH LONG TERM...JM AVIATION...08