Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/16/13


AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1103 AM MDT MON OCT 14 2013 .UPDATE...BAND OF CONVECTION CONTINUES TO PUSH EAST ACROSS THE PLAINS. MEANWHILE ADDITIONAL SHOWERS WERE DEVELOPING AND SPREADING SOUTHWARD BEHIND THE COLD FRONT WHICH HAD MOVED THROUGH GREELEY AND FORT COLLINS AND WILL PUSH ACROSS MOST OF DENVER METRO BY NOON AND PALMER DIVIDE AROUND 1 PM. HAVE MADE FURTHER MINOR ADJUSTMENTS TO PUSH STORMS EAST ACROSS THE EASTERN PLAINS BY 1 PM AND THEN HAVE SCATTERED SHOWER REDEVELOPMENT BEHIND THE FRONT ALONG THE I-25 CORRIDOR AND FOOTHILLS. IN THE HIGH COUNTRY...OROGRAPHICS AND GOOD UPSTREAM MOISTURE WILL KEEP SNOW SHOWERS GOING THROUGH THE AFTERNOON WITH ANOTHER 1-3 INCHES ACCUMULATION. EXISTING HIGHLIGHTS LOOK GOOD AS NORTHERN MOUNTAIN AREAS HAVE ALREADY SEEN 2-7 INCHES...AND GENERALLY 1-3 IN THE I-70 CORRIDOR. SHOWERS ARE EXPECTED TO GRADUALLY DECREASE THIS EVENING...BUT OVERALL HAD TO INCREASE POPS AND SNOW AMOUNTS SLIGHTLY GIVEN THE UPSTREAM MOISTURE AND DECENT OROGRAPHIC FLOW IN PLACE AS WINDS GO NORTHWESTERLY. && .AVIATION...FRONT WILL REACH KDEN AND KBJC AROUND 1720Z-1730Z AND THEN KAPA ABOUT 1830Z. GUSTY NORTH/NORTHEAST WINDS UP TO 25-28KTS POSSIBLE ESPECIALLY WITH ANY ENHANCEMENT FROM SHOWER OUTFLOWS. SCATTERED RAIN SHOWERS WILL LIKELY REDEVELOP BEHIND THE FRONT SO FEEL TEMPO -SHRA LOOKS GOOD THIS AFTERNOON. MOST PRECIPITATION SHOULD BE ENDING THIS EVENING BEFORE TEMPERATURES GET COLD ENOUGH TO SUPPORT MUCH IF ANY SNOWFALL. BIGGER CONCERN IS NOW SHIFTING TO POTENTIAL OF LOW STRATUS CEILINGS DEVELOPING BEHIND THE FRONT GIVEN THE UPSTREAM OBSERVATIONS AND VERY LOW T/TD SPREADS IN WYOMING. AS LONG AS UPSLOPE COMPONENT IS IN PLACE...WE WILL LIKELY HAVE LOWER CEILINGS THAN EXISTING FORECAST SO LOWERING THEM IN THE TAFS FOR NOW. && .PREV DISCUSSION... /ISSUED 759 AM MDT MON OCT 14 2013/ UPDATE...CONVECTION INCLUDING THUNDERSTORMS BREAKING OUT ALONG THE FRONT RANGE. HAVE UPDATED FORECAST FOR HIGHER POPS THIS MORNING AND THUNDERSTORMS. AVIATION...FOG IS IN THE PROCESS OF BEING REPLACED BY A BAND OF CONVECTIVE SHOWERS AND ISOLATED THUNDERSTORMS. MOST OF THESE WILL BE MOVING THROUGH 14Z-16Z WITH PARTIAL CLEARING AND SOME IMPROVEMENT IN CEILINGS WITH FRONT. COULD SEE GUSTS TO AROUND 35 KTS WITH THOSE SHOWERS AND STORMS. STILL A CHANCE OF SHOWERS AFTER 16Z BUT LESS WIND WITH THOSE. PREV DISCUSSION... /ISSUED 409 AM MDT MON OCT 14 2013/ SHORT TERM...TODAY AND TONIGHT...AN UPPER LEVEL TROUGH CENTERED NEAR THE FOUR CORNERS WILL LIFT NORTHEAST THIS MORNING AND CLOSE OFF OVER THE NEBRASKA PAN HANDLE AROUND 18Z. STRONG LIFT AHEAD OF THE TROUGH WILL CONTINUE TO BRING RAIN AND MOUNTAIN SNOW TO NORTHWEST AND NORTH CENTRAL COLORADO. SOUTHWEST FLOW AHEAD OF THE TROUGH IS BRINGING DRY AIR TO NORTHEAST COLORADO THIS MORNING...THE DRY SLOT. A SURFACE LOW OVER NORTHEAST COLORADO WILL MOVE INTO NEBRASKA THIS MORNING. AS IT LIFTS NORTHEAST IT WILL PULL A COLD FRONT ACROSS COLORADO. EXPECT THE FRONT TO PUSH ACROSS NORTHEAST COLORADO DURING THE LATE MORNING HOURS AS INDICATED BY THE GFS AND ECMWF. THE NAM...RAP AND HRRR ARE ALL MUCH LATER SHOWING THE FRONT PUSHING THROUGH DURING THE MID AFTERNOON. NORMALLY THE QUICKER SOLUTION OF THE GFS/ECMWF PANS OUT. APPEARS THE GFS IS HANDLING THE SURFACE PATTERN BETTER AND EXPECT ITS FORECAST TO BE BETTER. FOR THE FRONT RANGE...WILL HAVE TO WAIT UNTIL THE FRONT PASSES THROUGH AND UPSLOPE DEVELOPS FOR SHOWERS TO FORM. MOST OF THE SHOWERS WILL BE LIGHT AND DO NOT EXPECT MUCH FOR PRECIPITATION AMOUNTS. BETTER OROGRAPHIC LIFT WILL PREVAIL THIS AFTERNOON OVER THE MOUNTAINS DUE TO NORTHWEST FLOW AND COLD AIR ADVECTION. WILL KEEP THE ADVISORY GOING THROUGH 00Z. BASED ON CURRENT RADAR AND SATELLITE...APPEARS THE NORTH CENTRAL MOUNTAINS WILL SEE 2 TO 5 INCHES OF SNOW THROUGH SUNRISE. OROGRAPHIC LIFT TODAY SHOULD PRODUCE ANOTHER 2 TO 4 INCHES OF SNOW. ANOTHER THING TO WATCH WITH THIS SYSTEM WILL BE STRONG WINDS ON THE EASTERN PLAINS. STRONG COLD AIR ADVECTION BEHIND BEHIND THE FRONT WILL HELP STRONGER WINDS ALOFT MIX DOWN. THIS COMBINED WITH A TIGHT PRESSURE GRADIENT WILL PRODUCE WIND GUSTS OF 45 TO 55 MPH...JUST BELOW HIGH WIND CRITERIA. SOME WEAK SHOWERS WILL REMAIN POSSIBLE TONIGHT...MAINLY BEFORE MIDNIGHT. MAY GET COLD ENOUGH FOR A FEW SNOW SHOWERS ALONG THE FRONT RANGE AFTER SUNSET...BUT NO ACCUMULATION IS EXPECTED. EVEN THOUGH PRECIPITATION IS EXPECTED TO END...CLOUDY SKIES SHOULD LINGER THROUGH THE NIGHT. IT WILL BE A CHILLY NIGHT WITH MOST LOCATIONS FALLING BELOW FREEZING. LONG TERM...A CHILLY AND UNSETTLED AIRMASS IS STILL INDICATED OVER NORTHERN COLORADO AND WYOMING ON TUESDAY BENEATH A WESTERN EXTENSION OF THE MAIN UPPER TROUGH CENTERED EITHER OVER EASTERN SOUTH DAKOTA OR WESTERN MINNESOTA TUESDAY MORNING. MODELS ALSO INDICATE A 1030MB SFC HIGH IN THE COLDEST AIR COVERING NORTHERN WYOMING AND NORTH- NORTHWESTERLY SFC-700 MB FLOW OVER NORTH CENTRAL/NORTHEAST COLORADO. MODELS SHOW A SECONDARY UPPER LOW FORMING OVER EASTERN UTAH AROUND MIDDAY...AND THEN TRACKING SOUTHEASTWARD OVER SOUTHWESTERN COLORADO TUESDAY NIGHT. HEIGHT FALLS TO OUR SOUTHWEST IN COMBINATION WITH PRESSURE RISES IN ADVANCE OF THE SOUTHWARD TREKING SFC HIGH IS FORECAST TO PRODUCE WEAK TO MODERATE UPSLOPE FLOW OVER NORTHEAST COLORADO TUESDAY AFTERNOON/EVENING. AS A RESULT COULD SEE SCATTERED SNOW SHOWERS ON THE FRONT RANGE MTNS AND FOOTHILLS...AND ISOLATED RAIN AND SNOW SHOWERS ON THE ADJACENT PLAINS. ANY SNOW ACCUMULATION SHOULD BE MINIMAL. OVERNIGHT THIS SECONDARY UPPER LOW AND SFC HIGH MIGRATE SOUTH AND THE UPSLOPE FLOW ENDS...RESULTING IN AN END TO PRECIP AROUND HERE. MAX TEMPERATURES ON TUESDAY LIKELY TO BE THE COOLEST DURING THE UPCOMING WEEK. HIGHS AT LOWER ELEVATIONS NOT EXPECTED TO CLIMB OUT OF THE 40S. FOR REST OF THE WEEK...FLOW ALOFT RETURNS TO A NORTHWESTERLY COMPONENT WITH RIDGING OVER THE LOWER GREAT BASIN AND DESERT SOUTHWEST. THIS RESULTS IN WARMER TEMPERATURES AND DRY CONDITIONS ON WEDNESDAY. BY THURSDAY...THE ECMWF SHOWS A COLD FRONT RACING SOUTH OUT OF WYOMING AHEAD OF A CLIPPER SYSTEM DROPPING OUT OF THE NORTHERN ROCKIES. THE EC SHOWS THIS FRONT MOVING THROUGH NERN COLORADO THURSDAY MORNING. WHILE THE GFS DOESN/T SHOW IT ARRIVING UNTIL MUCH LATER IN THE DAY. THIS ADDS MORE UNCERTAINTY TO THE HIGH TEMPERATURE FCST FOR THAT DAY. THURSDAY NIGHT AND FRIDAY...ECMWF DRIVES THIS SYSTEM STRAIGHT SOUTH ALONG THE LEE SIDE OF THE ROCKIES INTO NORTHEAST COLORADO POTENTIALLY RESULTING IN AMPLE CLOUD COVER...SIGNIFICANTLY COOLER TEMPERATURES AND A GOOD CHANCE OF PRECIP...LIKELY IN THE FORM OF SNOW FOR THE MTNS AND PLAINS. THE CANADIAN GEM INDICATES A NEARLY SIMILAR PATTERN DEVELOPING...BUT NOT AS COLD OR AS WET. WHEREAS THE GFS SHOWS THIS SYSTEM JUST GLANCING THE AREA BRINGING ONLY SLIGHTLY COOLER TEMPERATURES AND ONLY A SLIGHT CHANCE OF PRECIP MAINLY TO THE NORTHEAST PLAINS. SINCE THIS IS STILL A FEW DAYS AWAY...WILL APPLY A BLEND OF THESE MODELS TO THIS FORECAST ISSUANCE. AVIATION...SOUTHERLY WINDS WILL TURN WEST THEN TO NORTHWEST THIS MORNING AHEAD OF AN APPROACHING COLD FRONT. THE FRONT IS EXPECTED TO PUSH THROUGH AROUND 16Z CAUSING WINDS TO TURN NORTHERLY. CLOUDS WILL INCREASE BEHIND THE FRONT AND SCATTERED RAIN SHOWERS WILL BE POSSIBLE. CEILINGS ARE EXPECTED TO BE 4000 TO 8000 FEET THIS AFTERNOON. CLOUDS WILL LOWER TONIGHT WITH CEILING OF 2000 TO 5000 FEET POSSIBLE. THERE WILL BE A CHANCE CEILINGS COULD FALL BELOW 2000 FEET BY 12Z TUESDAY. HYDROLOGY...NO CONCERNS. SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS WILL MOVE ACROSS THE AREA THROUGH THIS EVENING. RAINFALL AMOUNTS WILL BE LESS THAN A QUARTER INCH. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ031- 033. && $$ SHORT TERM...BARJENBRUCH LONG TERM....BAKER AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
759 AM MDT MON OCT 14 2013 .UPDATE...CONVECTION INCLUDING THUNDERSTORMS BREAKING OUT ALONG THE FRONT RANGE. HAVE UPDATED FORECAST FOR HIGHER POPS THIS MORNING AND THUNDERSTORMS. && .AVIATION...FOG IS IN THE PROCESS OF BEING REPLACED BY A BAND OF CONVECTIVE SHOWERS AND ISOLATED THUNDERSTORMS. MOST OF THESE WILL BE MOVING THROUGH 14Z-16Z WITH PARTIAL CLEARING AND SOME IMPROVEMENT IN CEILINGS WITH FRONT. COULD SEE GUSTS TO AROUND 35 KTS WITH THOSE SHOWERS AND STORMS. STILL A CHANCE OF SHOWERS AFTER 16Z BUT LESS WIND WITH THOSE. && .PREV DISCUSSION... /ISSUED 409 AM MDT MON OCT 14 2013/ SHORT TERM...TODAY AND TONIGHT...AN UPPER LEVEL TROUGH CENTERED NEAR THE FOUR CORNERS WILL LIFT NORTHEAST THIS MORNING AND CLOSE OFF OVER THE NEBRASKA PAN HANDLE AROUND 18Z. STRONG LIFT AHEAD OF THE TROUGH WILL CONTINUE TO BRING RAIN AND MOUNTAIN SNOW TO NORTHWEST AND NORTH CENTRAL COLORADO. SOUTHWEST FLOW AHEAD OF THE TROUGH IS BRINGING DRY AIR TO NORTHEAST COLORADO THIS MORNING...THE DRY SLOT. A SURFACE LOW OVER NORTHEAST COLORADO WILL MOVE INTO NEBRASKA THIS MORNING. AS IT LIFTS NORTHEAST IT WILL PULL A COLD FRONT ACROSS COLORADO. EXPECT THE FRONT TO PUSH ACROSS NORTHEAST COLORADO DURING THE LATE MORNING HOURS AS INDICATED BY THE GFS AND ECMWF. THE NAM...RAP AND HRRR ARE ALL MUCH LATER SHOWING THE FRONT PUSHING THROUGH DURING THE MID AFTERNOON. NORMALLY THE QUICKER SOLUTION OF THE GFS/ECMWF PANS OUT. APPEARS THE GFS IS HANDLING THE SURFACE PATTERN BETTER AND EXPECT ITS FORECAST TO BE BETTER. FOR THE FRONT RANGE...WILL HAVE TO WAIT UNTIL THE FRONT PASSES THROUGH AND UPSLOPE DEVELOPS FOR SHOWERS TO FORM. MOST OF THE SHOWERS WILL BE LIGHT AND DO NOT EXPECT MUCH FOR PRECIPITATION AMOUNTS. BETTER OROGRAPHIC LIFT WILL PREVAIL THIS AFTERNOON OVER THE MOUNTAINS DUE TO NORTHWEST FLOW AND COLD AIR ADVECTION. WILL KEEP THE ADVISORY GOING THROUGH 00Z. BASED ON CURRENT RADAR AND SATELLITE...APPEARS THE NORTH CENTRAL MOUNTAINS WILL SEE 2 TO 5 INCHES OF SNOW THROUGH SUNRISE. OROGRAPHIC LIFT TODAY SHOULD PRODUCE ANOTHER 2 TO 4 INCHES OF SNOW. ANOTHER THING TO WATCH WITH THIS SYSTEM WILL BE STRONG WINDS ON THE EASTERN PLAINS. STRONG COLD AIR ADVECTION BEHIND BEHIND THE FRONT WILL HELP STRONGER WINDS ALOFT MIX DOWN. THIS COMBINED WITH A TIGHT PRESSURE GRADIENT WILL PRODUCE WIND GUSTS OF 45 TO 55 MPH...JUST BELOW HIGH WIND CRITERIA. SOME WEAK SHOWERS WILL REMAIN POSSIBLE TONIGHT...MAINLY BEFORE MIDNIGHT. MAY GET COLD ENOUGH FOR A FEW SNOW SHOWERS ALONG THE FRONT RANGE AFTER SUNSET...BUT NO ACCUMULATION IS EXPECTED. EVEN THOUGH PRECIPITATION IS EXPECTED TO END...CLOUDY SKIES SHOULD LINGER THROUGH THE NIGHT. IT WILL BE A CHILLY NIGHT WITH MOST LOCATIONS FALLING BELOW FREEZING. LONG TERM...A CHILLY AND UNSETTLED AIRMASS IS STILL INDICATED OVER NORTHERN COLORADO AND WYOMING ON TUESDAY BENEATH A WESTERN EXTENSION OF THE MAIN UPPER TROUGH CENTERED EITHER OVER EASTERN SOUTH DAKOTA OR WESTERN MINNESOTA TUESDAY MORNING. MODELS ALSO INDICATE A 1030MB SFC HIGH IN THE COLDEST AIR COVERING NORTHERN WYOMING AND NORTH- NORTHWESTERLY SFC-700 MB FLOW OVER NORTH CENTRAL/NORTHEAST COLORADO. MODELS SHOW A SECONDARY UPPER LOW FORMING OVER EASTERN UTAH AROUND MIDDAY...AND THEN TRACKING SOUTHEASTWARD OVER SOUTHWESTERN COLORADO TUESDAY NIGHT. HEIGHT FALLS TO OUR SOUTHWEST IN COMBINATION WITH PRESSURE RISES IN ADVANCE OF THE SOUTHWARD TREKING SFC HIGH IS FORECAST TO PRODUCE WEAK TO MODERATE UPSLOPE FLOW OVER NORTHEAST COLORADO TUESDAY AFTERNOON/EVENING. AS A RESULT COULD SEE SCATTERED SNOW SHOWERS ON THE FRONT RANGE MTNS AND FOOTHILLS...AND ISOLATED RAIN AND SNOW SHOWERS ON THE ADJACENT PLAINS. ANY SNOW ACCUMULATION SHOULD BE MINIMAL. OVERNIGHT THIS SECONDARY UPPER LOW AND SFC HIGH MIGRATE SOUTH AND THE UPSLOPE FLOW ENDS...RESULTING IN AN END TO PRECIP AROUND HERE. MAX TEMPERATURES ON TUESDAY LIKELY TO BE THE COOLEST DURING THE UPCOMING WEEK. HIGHS AT LOWER ELEVATIONS NOT EXPECTED TO CLIMB OUT OF THE 40S. FOR REST OF THE WEEK...FLOW ALOFT RETURNS TO A NORTHWESTERLY COMPONENT WITH RIDGING OVER THE LOWER GREAT BASIN AND DESERT SOUTHWEST. THIS RESULTS IN WARMER TEMPERATURES AND DRY CONDITIONS ON WEDNESDAY. BY THURSDAY...THE ECMWF SHOWS A COLD FRONT RACING SOUTH OUT OF WYOMING AHEAD OF A CLIPPER SYSTEM DROPPING OUT OF THE NORTHERN ROCKIES. THE EC SHOWS THIS FRONT MOVING THROUGH NERN COLORADO THURSDAY MORNING. WHILE THE GFS DOESN/T SHOW IT ARRIVING UNTIL MUCH LATER IN THE DAY. THIS ADDS MORE UNCERTAINTY TO THE HIGH TEMPERATURE FCST FOR THAT DAY. THURSDAY NIGHT AND FRIDAY...ECMWF DRIVES THIS SYSTEM STRAIGHT SOUTH ALONG THE LEE SIDE OF THE ROCKIES INTO NORTHEAST COLORADO POTENTIALLY RESULTING IN AMPLE CLOUD COVER...SIGNIFICANTLY COOLER TEMPERATURES AND A GOOD CHANCE OF PRECIP...LIKELY IN THE FORM OF SNOW FOR THE MTNS AND PLAINS. THE CANADIAN GEM INDICATES A NEARLY SIMILAR PATTERN DEVELOPING...BUT NOT AS COLD OR AS WET. WHEREAS THE GFS SHOWS THIS SYSTEM JUST GLANCING THE AREA BRINGING ONLY SLIGHTLY COOLER TEMPERATURES AND ONLY A SLIGHT CHANCE OF PRECIP MAINLY TO THE NORTHEAST PLAINS. SINCE THIS IS STILL A FEW DAYS AWAY...WILL APPLY A BLEND OF THESE MODELS TO THIS FORECAST ISSUANCE. AVIATION...SOUTHERLY WINDS WILL TURN WEST THEN TO NORTHWEST THIS MORNING AHEAD OF AN APPROACHING COLD FRONT. THE FRONT IS EXPECTED TO PUSH THROUGH AROUND 16Z CAUSING WINDS TO TURN NORTHERLY. CLOUDS WILL INCREASE BEHIND THE FRONT AND SCATTERED RAIN SHOWERS WILL BE POSSIBLE. CEILINGS ARE EXPECTED TO BE 4000 TO 8000 FEET THIS AFTERNOON. CLOUDS WILL LOWER TONIGHT WITH CEILING OF 2000 TO 5000 FEET POSSIBLE. THERE WILL BE A CHANCE CEILINGS COULD FALL BELOW 2000 FEET BY 12Z TUESDAY. HYDROLOGY...NO CONCERNS. SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS WILL MOVE ACROSS THE AREA THROUGH THIS EVENING. RAINFALL AMOUNTS WILL BE LESS THAN A QUARTER INCH. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ031- 033. && $$ SHORT TERM...BARJENBRUCH LONG TERM....BAKER AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
409 AM MDT MON OCT 14 2013 .SHORT TERM...TODAY AND TONIGHT...AN UPPER LEVEL TROUGH CENTERED NEAR THE FOUR CORNERS WILL LIFT NORTHEAST THIS MORNING AND CLOSE OFF OVER THE NEBRASKA PAN HANDLE AROUND 18Z. STRONG LIFT AHEAD OF THE TROUGH WILL CONTINUE TO BRING RAIN AND MOUNTAIN SNOW TO NORTHWEST AND NORTH CENTRAL COLORADO. SOUTHWEST FLOW AHEAD OF THE TROUGH IS BRINGING DRY AIR TO NORTHEAST COLORADO THIS MORNING...THE DRY SLOT. A SURFACE LOW OVER NORTHEAST COLORADO WILL MOVE INTO NEBRASKA THIS MORNING. AS IT LIFTS NORTHEAST IT WILL PULL A COLD FRONT ACROSS COLORADO. EXPECT THE FRONT TO PUSH ACROSS NORTHEAST COLORADO DURING THE LATE MORNING HOURS AS INDICATED BY THE GFS AND ECMWF. THE NAM...RAP AND HRRR ARE ALL MUCH LATER SHOWING THE FRONT PUSHING THROUGH DURING THE MID AFTERNOON. NORMALLY THE QUICKER SOLUTION OF THE GFS/ECMWF PANS OUT. APPEARS THE GFS IS HANDLING THE SURFACE PATTERN BETTER AND EXPECT ITS FORECAST TO BE BETTER. FOR THE FRONT RANGE...WILL HAVE TO WAIT UNTIL THE FRONT PASSES THROUGH AND UPSLOPE DEVELOPS FOR SHOWERS TO FORM. MOST OF THE SHOWERS WILL BE LIGHT AND DO NOT EXPECT MUCH FOR PRECIPITATION AMOUNTS. BETTER OROGRAPHIC LIFT WILL PREVAIL THIS AFTERNOON OVER THE MOUNTAINS DUE TO NORTHWEST FLOW AND COLD AIR ADVECTION. WILL KEEP THE ADVISORY GOING THROUGH 00Z. BASED ON CURRENT RADAR AND SATELLITE...APPEARS THE NORTH CENTRAL MOUNTAINS WILL SEE 2 TO 5 INCHES OF SNOW THROUGH SUNRISE. OROGRAPHIC LIFT TODAY SHOULD PRODUCE ANOTHER 2 TO 4 INCHES OF SNOW. ANOTHER THING TO WATCH WITH THIS SYSTEM WILL BE STRONG WINDS ON THE EASTERN PLAINS. STRONG COLD AIR ADVECTION BEHIND BEHIND THE FRONT WILL HELP STRONGER WINDS ALOFT MIX DOWN. THIS COMBINED WITH A TIGHT PRESSURE GRADIENT WILL PRODUCE WIND GUSTS OF 45 TO 55 MPH...JUST BELOW HIGH WIND CRITERIA. SOME WEAK SHOWERS WILL REMAIN POSSIBLE TONIGHT...MAINLY BEFORE MIDNIGHT. MAY GET COLD ENOUGH FOR A FEW SNOW SHOWERS ALONG THE FRONT RANGE AFTER SUNSET...BUT NO ACCUMULATION IS EXPECTED. EVEN THOUGH PRECIPITATION IS EXPECTED TO END...CLOUDY SKIES SHOULD LINGER THROUGH THE NIGHT. IT WILL BE A CHILLY NIGHT WITH MOST LOCATIONS FALLING BELOW FREEZING. .LONG TERM...A CHILLY AND UNSETTLED AIRMASS IS STILL INDICATED OVER NORTHERN COLORADO AND WYOMING ON TUESDAY BENEATH A WESTERN EXTENSION OF THE MAIN UPPER TROUGH CENTERED EITHER OVER EASTERN SOUTH DAKOTA OR WESTERN MINNESOTA TUESDAY MORNING. MODELS ALSO INDICATE A 1030MB SFC HIGH IN THE COLDEST AIR COVERING NORTHERN WYOMING AND NORTH- NORTHWESTERLY SFC-700 MB FLOW OVER NORTH CENTRAL/NORTHEAST COLORADO. MODELS SHOW A SECONDARY UPPER LOW FORMING OVER EASTERN UTAH AROUND MIDDAY...AND THEN TRACKING SOUTHEASTWARD OVER SOUTHWESTERN COLORADO TUESDAY NIGHT. HEIGHT FALLS TO OUR SOUTHWEST IN COMBINATION WITH PRESSURE RISES IN ADVANCE OF THE SOUTHWARD TREKING SFC HIGH IS FORECAST TO PRODUCE WEAK TO MODERATE UPSLOPE FLOW OVER NORTHEAST COLORADO TUESDAY AFTERNOON/EVENING. AS A RESULT COULD SEE SCATTERED SNOW SHOWERS ON THE FRONT RANGE MTNS AND FOOTHILLS...AND ISOLATED RAIN AND SNOW SHOWERS ON THE ADJACENT PLAINS. ANY SNOW ACCUMULATION SHOULD BE MINIMAL. OVERNIGHT THIS SECONDARY UPPER LOW AND SFC HIGH MIGRATE SOUTH AND THE UPSLOPE FLOW ENDS...RESULTING IN AN END TO PRECIP AROUND HERE. MAX TEMPERATURES ON TUESDAY LIKELY TO BE THE COOLEST DURING THE UPCOMING WEEK. HIGHS AT LOWER ELEVATIONS NOT EXPECTED TO CLIMB OUT OF THE 40S. FOR REST OF THE WEEK...FLOW ALOFT RETURNS TO A NORTHWESTERLY COMPONENT WITH RIDGING OVER THE LOWER GREAT BASIN AND DESERT SOUTHWEST. THIS RESULTS IN WARMER TEMPERATURES AND DRY CONDITIONS ON WEDNESDAY. BY THURSDAY...THE ECMWF SHOWS A COLD FRONT RACING SOUTH OUT OF WYOMING AHEAD OF A CLIPPER SYSTEM DROPPING OUT OF THE NORTHERN ROCKIES. THE EC SHOWS THIS FRONT MOVING THROUGH NERN COLORADO THURSDAY MORNING. WHILE THE GFS DOESN/T SHOW IT ARRIVING UNTIL MUCH LATER IN THE DAY. THIS ADDS MORE UNCERTAINTY TO THE HIGH TEMPERATURE FCST FOR THAT DAY. THURSDAY NIGHT AND FRIDAY...ECMWF DRIVES THIS SYSTEM STRAIGHT SOUTH ALONG THE LEE SIDE OF THE ROCKIES INTO NORTHEAST COLORADO POTENTIALLY RESULTING IN AMPLE CLOUD COVER...SIGNIFICANTLY COOLER TEMPERATURES AND A GOOD CHANCE OF PRECIP...LIKELY IN THE FORM OF SNOW FOR THE MTNS AND PLAINS. THE CANADIAN GEM INDICATES A NEARLY SIMILAR PATTERN DEVELOPING...BUT NOT AS COLD OR AS WET. WHEREAS THE GFS SHOWS THIS SYSTEM JUST GLANCING THE AREA BRINGING ONLY SLIGHTLY COOLER TEMPERATURES AND ONLY A SLIGHT CHANCE OF PRECIP MAINLY TO THE NORTHEAST PLAINS. SINCE THIS IS STILL A FEW DAYS AWAY...WILL APPLY A BLEND OF THESE MODELS TO THIS FORECAST ISSUANCE. && .AVIATION...SOUTHERLY WINDS WILL TURN WEST THEN TO NORTHWEST THIS MORNING AHEAD OF AN APPROACHING COLD FRONT. THE FRONT IS EXPECTED TO PUSH THROUGH AROUND 16Z CAUSING WINDS TO TURN NORTHERLY. CLOUDS WILL INCREASE BEHIND THE FRONT AND SCATTERED RAIN SHOWERS WILL BE POSSIBLE. CEILINGS ARE EXPECTED TO BE 4000 TO 8000 FEET THIS AFTERNOON. CLOUDS WILL LOWER TONIGHT WITH CEILING OF 2000 TO 5000 FEET POSSIBLE. THERE WILL BE A CHANCE CEILINGS COULD FALL BELOW 2000 FEET BY 12Z TUESDAY. && .HYDROLOGY...NO CONCERNS. SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS WILL MOVE ACROSS THE AREA THROUGH THIS EVENING. RAINFALL AMOUNTS WILL BE LESS THAN A QUARTER INCH. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ031- 033. && $$ SHORT TERM...MEIER LONG TERM....BAKER AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
913 AM EDT MON OCT 14 2013 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE THROUGH TUESDAY...THEN WEAKEN TUESDAY NIGHT INTO WEDNESDAY...DRIFTING INTO THE CANADIAN MARITIMES. WEAK LOW PRESSURE WILL DEVELOP OFF THE EAST COAST WHILE A FRONTAL SYSTEM APPROACHES FROM THE GREAT LAKES. THE COLD FRONT WILL MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. WAVES OF LOW PRESSURE ARE THEN FORECAST TO IMPACT THE AREA FRIDAY AND SATURDAY NIGHT. ANOTHER COLD FRONT MOVES THROUGH LATE SATURDAY NIGHT INTO SUNDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FORECAST ON TRACK. HIGH PRESSURE REMAINS STRONG...ESPECIALLY NORTH AND EAST OF THE LOCAL REGION. ALOFT...A RIDGE WILL REMAIN DOMINANT WITH ITS BASE TO OUR SOUTH. A COLD FRONT ASSOCIATED WITH AN EQUIVALENT BAROTROPIC LOW IN EASTERN CANADA WILL WEAKEN THROUGH THE DAY WITH EASTWARD MOVEMENT. THE LOSS OF TEMPERATURE ADVECTIONS WILL CONTRIBUTE TO THE WEAKENING OF THIS SYSTEM AND INHERENTLY RESULTING IN THE FRONTOLYSIS. THE ONLY EFFECT OF THE FRONT WILL BE AN INCREASE IN THE MOISTURE IN THE 700 TO 850 MB COLUMN LATE THIS AFTERNOON. THE LOWEST INVERSION AROUND 900MB GOING INTO THIS MORNING IS SHOWN TO MIX OUT BUT THE ONE AROUND 700 TO 800MB WILL REMAIN ALLOWING FOR MOISTURE TO COLLECT HERE. THIS IS WHERE CLOUDS WILL DEVELOP. THERE IS UNCERTAINTY ON EXACTLY HOW MUCH CLOUDS THERE WILL BE AND THE TIMING OF THE HIGHER CLOUD COVERAGE AND THIS IS ONE PARAMETER THAT COULD FLUCTUATE WITH SUBSEQUENT FORECASTS. THE NAM AND RUC BUFKITS INDICATE THIS POSSIBILITY BUT DIFFER ON THE TIMING WHILE THE GFS BUFKITS DOES NOT MOISTEN THE 700 TO 850MB LAYER BUT IS SLOWER TO MIX OUT THE LOWEST INVERSION AROUND 900MB WITH ITS CLOUDS THIS MORNING. THE RESULTING UNCERTAINTY WAS THE REASON WHY AN EQUAL BLEND OF MAV AND MET GUIDANCE WAS CHOSEN FOR HIGH TEMPERATURES TODAY...WHICH ARE FORECAST TO BE IN THE MID TO UPPER 60S FOR A MAJORITY OF THE REGION. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... HIGH PRESSURE WILL REMAIN DOMINANT TONIGHT WITH A WEAK COLD FRONT APPROACHING FROM THE WEST AND DISSIPATING. ONLY EXPECTING AN INCREASE IN CLOUDS FROM THIS WITHIN THE 700-850MB LAYER FROM WEST TO EAST. THERE IS A LITTLE HIGHER CONFIDENCE ON MORE CLOUDS TONIGHT. HENCE...LOWS WERE PREFERRED WITH A 3/4 MET WARMER GUIDANCE TO 1/4 COOLER MAV GUIDANCE. WILL KEEP FORECAST ON THE SLOWER SIDE WITH PROGRESSION OF CLOUDS CONSIDERING THE LOWERING BOUNDARY LAYER FLOW AND LACK OF WINDS TO MIX DOWN. THIS WILL RESULT IN MORE CLOUDS FOR TONIGHT. GOING WITH A WARMER DAY TUESDAY AS THE RIDGE SHIFTS EAST AND THERE IS MORE OF A SOUTHWEST FLOW ALOFT. THERE IS SOME PRETTY GOOD LOW LEVEL WARM ADVECTION TOO WITH THE SOUTHEAST FLOW AT 850MB VEERING TO THE SOUTHWEST FLOW AT 700MB. THE WINDS ARE SLIGHTLY MORE THAN THE PREVIOUS DAY. HIGH TEMPS WERE A BLEND OF THE WARMER MET 2/3 AND COOLER 1/3 MAV CONSIDERING THE WARM AIR ADVECTION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... UPPER LEVEL RIDGE AXIS WILL SLIDE E OF THE AREA BY WED EVE WITH A TROUGH TRACKING TOWARDS THE AREA FROM THE GREAT LAKES/OHIO VALLEY REGION. THERE ARE TIMING DIFFERENCES WITH THE PROGRESSION OF THIS FIRST TROUGH WHICH HAS A RIPPLE EFFECT ON LATER PERIODS. THE GFS/GEFS MEAN IS FASTEST...FOLLOWED CLOSELY BY THE EC AND SREF...THEN THE NAM AND CMC AND LASTLY THE UKMET. HAVE STUCK WITH A MIDDLE OF THE ROAD SOLN...NAM/SREF BLEND UNTIL THIS IS BETTER RESOLVED. MEANWHILE...A BROAD UPPER LEVEL TROUGH WILL BE CARVED OUT THROUGH CENTRAL NOAM. A PROGRESSIVE PATTERN WILL DEVELOP ACROSS THE EASTERN US IN RESPONSE TO A TIGHT SW FLOW ALOFT. ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE NORTHEAST THU NIGHT/FRI...WITH YET ANOTHER NEXT WEEKEND. AT THE SFC...HIGH PRES ENTRENCHED DOWN THE APPALACHIANS WILL WEAKEN AS AN INVERTED TROUGH DEVELOPS OFF THE EAST COAST. MODELS ARE VARYING WITH THE PRONUNCIATION OF THIS FEATURE AND HOW MUCH IT WILL IMPACT THE LOCAL AREA ON WED. FOR NOW HAVE SCHC POPS ACROSS THE EAST END ALTHOUGH SOME OF THIS SYSTEMS MOISTURE MAY BE INFUSED INTO AN APPROACHING COLD FRONT AND COULD PRODUCE SOME SHOWERS WELL OUT AHEAD OF IT. HAVE THE FRONT MOVING THROUGH LATE WED NIGHT/THU MORNING...CONSISTENT WITH A NAM/SREF BLEND AS STATED ABOVE. THE PROGRESSIVE FLOW DEVELOPING ALOFT WILL ALSO BE TRANSLATED TO THE SFC. WEAK HIGH PRES RETURNS IN THE WAKE OF THE FRONT WITH LOW PRES PASSING S OF LONG ISLAND THU NIGHT OR FRI. DRY CONDITIONS THEN RETURN AGAIN FRI NIGHT INTO SAT COURTESY OF HIGH PRES BUILDING TO OUR S...BUT A WAVE OF LOW PRES DEVELOPING OVER THE GULF COAST RIDES ALONG ANOTHER COLD FRONT MARCHING TOWARDS THE AREA NEXT WEEKEND. TEMPERATURES WILL START OFF 5 TO 10 DEGREES ABOVE NORMAL...BUT WILL GRADUALLY RETURN TO SEASONABLE LEVELS IN THE LOWER TO MID 60S DURING THE DAY AND 40S...AROUND 50 IN NYC...AT NIGHT NEXT WEEKEND. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE WILL SETTLE OVER THE AREA TODAY. PATCHES OF MVFR CIGS CONTINUE...IMPACTING ABOUT HALF THE AREA. WILL CONTINUE TO MONITOR TRENDS. AMENDMENTS ARE LIKELY AS FORECASTING THESE CLOUDS REMAINS QUITE A CHALLENGE THIS MORNING. LIGHT NE FLOW SHOULD BECOME SE-S 5-10 KT BY AFTERNOON. IT IS UNCERTAIN EXACTLY WHERE THE HIGH PRESSURE RIDGE WILL BE ORIENTED BY LATE DAY...SO WIND DIRECTION FORECAST CONFIDENCE LOWERS LATE IN THE DAY. SPEEDS REMAIN LESS THAN 10 KT. SCT TO BROKEN CLOUDS 5 TO 10 KFT ARE ANTICIPATED LATE TODAY AND TONIGHT AS AN APPROACHING FRONTAL BOUNDARY WEAKENS. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: TIMING OF WIND SHIFT FROM NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO S/SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KLGA FCSTER COMMENTS: TIMING OF WIND SHIFT FROM NE TO E/SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KTEB FCSTER COMMENTS: CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KHPN FCSTER COMMENTS: POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KISP FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. OUTLOOK FOR 12Z TUE THROUGH FRI... .TUE...VFR. .TUE NIGHT...POSSIBLE SUB VFR IN STRATUS AND FOG. .WED-FRI...MVFR CONDITIONS POSSIBLE AT TIMES IN SCT SHOWERS. && .MARINE... THE SURFACE PRESSURE GRADIENT HAS WEAKENED AND WIND HAS DIMINISHED. THE PRESSURE GRADIENT CONTINUES TO WEAKEN THROUGH THE DAY. IN RESPONSE SEAS ON THE OCEAN WATERS HAVE FALLEN BELOW 5 FT. THE SMALL CRAFT FOR HAZARDOUS SEAS HAS BEEN CANCELLED. THEREAFTER WITH WEAK PRESSURE GRADIENTS IN PLACE...SUB SCA CONDITIONS WILL BE FORECAST GOING INTO MONDAY NIGHT AND TUESDAY. A RELATIVELY WEAK FLOW WILL REMAIN ACROSS THE WATERS THROUGH THE END OF THE WEEK RESULTING IN SUB-SCA CONDS. && .HYDROLOGY... DRY WEATHER IS FORECAST THROUGH TUESDAY. GENERALLY BETWEEN 1/4 AND 1/2 INCH OF RAINFALL IS EXPECTED WITH THE COLD FRONTAL PASSAGE LATE WED NIGHT/THU MORNING. NO HYDROLOGIC ISSUES ARE ANTICIPATED WITH THIS. && .EQUIPMENT... DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM. DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
728 AM EDT MON OCT 14 2013 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE THROUGH TUESDAY...REMAINING GENERALLY NORTH AND EAST OF THE WATERS. THIS HIGH PRESSURE AREA WEAKENS TUESDAY NIGHT INTO WEDNESDAY AS IT SHIFTS INTO THE CANADIAN MARITIMES. AS HIGH PRESSURE MOVES OUT TO SEA...WEAK LOW PRESSURE WILL DEVELOP OFF THE EAST COAST WHILE A FRONTAL SYSTEM APPROACHES FROM THE GREAT LAKES. THIS SYSTEMS COLD FRONT WILL MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT OR THURSDAY MORNING. WAVES OF LOW PRESSURE ARE THEN FORECAST TO IMPACT THE AREA FRIDAY AND SATURDAY NIGHT. ANOTHER COLD FRONT MOVES THROUGH LATE SATURDAY NIGHT INTO SUNDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LOWERED CLOUDS FOR EASTERN HALF OF REGION AS WELL AS LOWERED TEMPERATURES WITH VASTLY DIFFERENT RADIATIONAL COOLING BECAUSE OF THE PATCHY CLOUD COVERAGE. OTHER THAN THAT...FORECAST MAINLY ON TRACK. PATCHY FOG WILL DISSIPATE WITH DIURNAL WARMING THIS MORNING ACROSS THE INTERIOR AND RURAL AREAS. HIGH PRESSURE REMAINS STRONG...ESPECIALLY NORTH AND EAST OF THE LOCAL REGION. ALOFT...A RIDGE WILL REMAIN DOMINANT WITH ITS BASE TO OUR SOUTH. A COLD FRONT ASSOCIATED WITH AN EQUIVALENT BAROTROPIC LOW IN EASTERN CANADA WILL WEAKEN THROUGH THE DAY WITH EASTWARD MOVEMENT. THE LOSS OF TEMPERATURE ADVECTIONS WILL CONTRIBUTE TO THE WEAKENING OF THIS SYSTEM AND INHERENTLY RESULTING IN THE FRONTOLYSIS. THE ONLY EFFECT OF THE FRONT WILL BE AN INCREASE IN THE MOISTURE IN THE 700 TO 850 MB COLUMN LATE THIS AFTERNOON. THE LOWEST INVERSION AROUND 900MB GOING INTO THIS MORNING IS SHOWN TO MIX OUT BUT THE ONE AROUND 700 TO 800MB WILL REMAIN ALLOWING FOR MOISTURE TO COLLECT HERE. THIS IS WHERE CLOUDS WILL DEVELOP. THERE IS UNCERTAINTY ON EXACTLY HOW MUCH CLOUDS THERE WILL BE AND THE TIMING OF THE HIGHER CLOUD COVERAGE AND THIS IS ONE PARAMETER THAT COULD FLUCTUATE WITH SUBSEQUENT FORECASTS. THE NAM AND RUC BUFKITS INDICATE THIS POSSIBILITY BUT DIFFER ON THE TIMING WHILE THE GFS BUFKITS DOES NOT MOISTEN THE 700 TO 850MB LAYER BUT IS SLOWER TO MIX OUT THE LOWEST INVERSION AROUND 900MB WITH ITS CLOUDS THIS MORNING. THE RESULTING UNCERTAINTY WAS THE REASON WHY AN EQUAL BLEND OF MAV AND MET GUIDANCE WAS CHOSEN FOR HIGH TEMPERATURES TODAY...WHICH ARE FORECAST TO BE IN THE MID TO UPPER 60S FOR A MAJORITY OF THE REGION. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... HIGH PRESSURE WILL REMAIN DOMINANT TONIGHT WITH A WEAK COLD FRONT APPROACHING FROM THE WEST AND DISSIPATING. ONLY EXPECTING AN INCREASE IN CLOUDS FROM THIS WITHIN THE 700-850MB LAYER FROM WEST TO EAST. THERE IS A LITTLE HIGHER CONFIDENCE ON MORE CLOUDS TONIGHT. HENCE...LOWS WERE PREFERRED WITH A 3/4 MET WARMER GUIDANCE TO 1/4 COOLER MAV GUIDANCE. WILL KEEP FORECAST ON THE SLOWER SIDE WITH PROGRESSION OF CLOUDS CONSIDERING THE LOWERING BOUNDARY LAYER FLOW AND LACK OF WINDS TO MIX DOWN. THIS WILL RESULT IN MORE CLOUDS FOR TONIGHT. GOING WITH A WARMER DAY TUESDAY AS THE RIDGE SHIFTS EAST AND THERE IS MORE OF A SOUTHWEST FLOW ALOFT. THERE IS SOME PRETTY GOOD LOW LEVEL WARM ADVECTION TOO WITH THE SOUTHEAST FLOW AT 850MB VEERING TO THE SOUTHWEST FLOW AT 700MB. THE WINDS ARE SLIGHTLY MORE THAN THE PREVIOUS DAY. HIGH TEMPS WERE A BLEND OF THE WARMER MET 2/3 AND COOLER 1/3 MAV CONSIDERING THE WARM AIR ADVECTION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... UPPER LEVEL RIDGE AXIS WILL SLIDE E OF THE AREA BY WED EVE WITH A TROUGH TRACKING TOWARDS THE AREA FROM THE GREAT LAKES/OHIO VALLEY REGION. THERE ARE TIMING DIFFERENCES WITH THE PROGRESSION OF THIS FIRST TROUGH WHICH HAS A RIPPLE EFFECT ON LATER PERIODS. THE GFS/GEFS MEAN IS FASTEST...FOLLOWED CLOSELY BY THE EC AND SREF...THEN THE NAM AND CMC AND LASTLY THE UKMET. HAVE STUCK WITH A MIDDLE OF THE ROAD SOLN...NAM/SREF BLEND UNTIL THIS IS BETTER RESOLVED. MEANWHILE...A BROAD UPPER LEVEL TROUGH WILL BE CARVED OUT THROUGH CENTRAL NOAM. A PROGRESSIVE PATTERN WILL DEVELOP ACROSS THE EASTERN US IN RESPONSE TO A TIGHT SW FLOW ALOFT. ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE NORTHEAST THU NIGHT/FRI...WITH YET ANOTHER NEXT WEEKEND. AT THE SFC...HIGH PRES ENTRENCHED DOWN THE APPALACHIANS WILL WEAKEN AS AN INVERTED TROUGH DEVELOPS OFF THE EAST COAST. MODELS ARE VARYING WITH THE PRONUNCIATION OF THIS FEATURE AND HOW MUCH IT WILL IMPACT THE LOCAL AREA ON WED. FOR NOW HAVE SCHC POPS ACROSS THE EAST END ALTHOUGH SOME OF THIS SYSTEMS MOISTURE MAY BE INFUSED INTO AN APPROACHING COLD FRONT AND COULD PRODUCE SOME SHOWERS WELL OUT AHEAD OF IT. HAVE THE FRONT MOVING THROUGH LATE WED NIGHT/THU MORNING...CONSISTENT WITH A NAM/SREF BLEND AS STATED ABOVE. THE PROGRESSIVE FLOW DEVELOPING ALOFT WILL ALSO BE TRANSLATED TO THE SFC. WEAK HIGH PRES RETURNS IN THE WAKE OF THE FRONT WITH LOW PRES PASSING S OF LONG ISLAND THU NIGHT OR FRI. DRY CONDITIONS THEN RETURN AGAIN FRI NIGHT INTO SAT COURTESY OF HIGH PRES BUILDING TO OUR S...BUT A WAVE OF LOW PRES DEVELOPING OVER THE GULF COAST RIDES ALONG ANOTHER COLD FRONT MARCHING TOWARDS THE AREA NEXT WEEKEND. TEMPERATURES WILL START OFF 5 TO 10 DEGREES ABOVE NORMAL...BUT WILL GRADUALLY RETURN TO SEASONABLE LEVELS IN THE LOWER TO MID 60S DURING THE DAY AND 40S...AROUND 50 IN NYC...AT NIGHT NEXT WEEKEND. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE WILL SETTLE OVER THE AREA TODAY. PATCHES OF MVFR CIGS CONTINUE...IMPACTING ABOUT HALF THE AREA. WILL CONTINUE TO MONITOR TRENDS. AMENDMENTS ARE LIKELY AS FORECASTING THESE CLOUDS REMAINS QUITE A CHALLENGE THIS MORNING. LIGHT NE FLOW SHOULD BECOME SE-S 5-10 KT BY AFTERNOON. IT IS UNCERTAIN EXACTLY WHERE THE HIGH PRESSURE RIDGE WILL BE ORIENTED BY LATE DAY...SO WIND DIRECTION FORECAST CONFIDENCE LOWERS LATE IN THE DAY. SPEEDS REMAIN LESS THAN 10 KT. SCT TO BROKEN CLOUDS 5 TO 10 KFT ARE ANTICIPATED LATE TODAY AND TONIGHT AS AN APPROACHING FRONTAL BOUNDARY WEAKENS. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: TIMING OF WIND SHIFT FROM NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO S/SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KLGA FCSTER COMMENTS: TIMING OF WIND SHIFT FROM NE TO E/SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KTEB FCSTER COMMENTS: CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KHPN FCSTER COMMENTS: POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. KISP FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING AROUND OR JUST UNDER 3 KFT AT TIMES THIS MORNING. OUTLOOK FOR 12Z TUE THROUGH FRI... .TUE...VFR. .TUE NIGHT...POSSIBLE SUB VFR IN STRATUS AND FOG. .WED-FRI...MVFR CONDITIONS POSSIBLE AT TIMES IN SCT SHOWERS. && .MARINE... SEAS ARE ON A SLOW DECLINE WITH WAVE HEIGHTS. HOWEVER...THERE IS STILL A 8 SEC EASTERLY SWELL WHICH WILL ENABLE FOR THE FURTHER DECREASES IN WAVE HEIGHT TO BE RATHER SLOW. WAVEWATCH IS ALSO NOW RUNNING A LITTLE LOW IN TERMS OF THE WAVE HEIGHT AT BUOY 44025. THE PRESSURE GRADIENT WILL WEAKEN CONSIDERABLY GOING INTO THE DAY SO THE SMALL CRAFT WAS CONVERTED TO ONE JUST FOR HAZARDOUS SEAS. GUSTS WILL BE LOWERING WITH CURRENT GUSTS ONLY UP TO 20 KT ON THE OCEAN. THE TIMING IS SUCH THAT THE OCEAN WEST OF MORICHES INLET WILL HAVE SMALL CRAFT CONDITIONS UNTIL 18Z WHILE EAST OF THERE...IT REMAINS UNTIL 16Z. THEREAFTER WITH WEAK PRESSURE GRADIENTS IN PLACE...SUB SCA CONDITIONS WILL BE FORECAST GOING INTO MONDAY NIGHT AND TUESDAY. A RELATIVELY WEAK FLOW WILL REMAIN ACROSS THE WATERS THROUGH THE END OF THE WEEK RESULTING IN SUB-SCA CONDS. && .HYDROLOGY... DRY WEATHER IS FORECAST THROUGH TUESDAY. GENERALLY BETWEEN 1/4 AND 1/2 INCH OF RAINFALL IS EXPECTED WITH THE COLD FRONTAL PASSAGE LATE WED NIGHT/THU MORNING. NO HYDROLOGIC ISSUES ARE ANTICIPATED WITH THIS. && .EQUIPMENT... DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM. DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353-355. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EDT TODAY FOR ANZ350. && $$ SYNOPSIS...24/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...24 AVIATION...PW MARINE...24/JM HYDROLOGY...24/JM EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
706 AM EDT MON OCT 14 2013 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE THROUGH TUESDAY...REMAINING GENERALLY NORTH AND EAST OF THE WATERS. THIS HIGH PRESSURE AREA WEAKENS TUESDAY NIGHT INTO WEDNESDAY AS IT SHIFTS INTO THE CANADIAN MARITIMES. AS HIGH PRESSURE MOVES OUT TO SEA...WEAK LOW PRESSURE WILL DEVELOP OFF THE EAST COAST WHILE A FRONTAL SYSTEM APPROACHES FROM THE GREAT LAKES. THIS SYSTEMS COLD FRONT WILL MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT OR THURSDAY MORNING. WAVES OF LOW PRESSURE ARE THEN FORECAST TO IMPACT THE AREA FRIDAY AND SATURDAY NIGHT. ANOTHER COLD FRONT MOVES THROUGH LATE SATURDAY NIGHT INTO SUNDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LOWERED CLOUDS FOR EASTERN HALF OF REGION AS WELL AS LOWERED TEMPERATURES WITH VASTLY DIFFERENT RADIATIONAL COOLING BECAUSE OF THE PATCHY CLOUD COVERAGE. OTHER THAN THAT...FORECAST MAINLY ON TRACK. PATCHY FOG WILL DISSIPATE WITH DIURNAL WARMING THIS MORNING ACROSS THE INTERIOR AND RURAL AREAS. HIGH PRESSURE REMAINS STRONG...ESPECIALLY NORTH AND EAST OF THE LOCAL REGION. ALOFT...A RIDGE WILL REMAIN DOMINANT WITH ITS BASE TO OUR SOUTH. A COLD FRONT ASSOCIATED WITH AN EQUIVALENT BAROTROPIC LOW IN EASTERN CANADA WILL WEAKEN THROUGH THE DAY WITH EASTWARD MOVEMENT. THE LOSS OF TEMPERATURE ADVECTIONS WILL CONTRIBUTE TO THE WEAKENING OF THIS SYSTEM AND INHERENTLY RESULTING IN THE FRONTOLYSIS. THE ONLY EFFECT OF THE FRONT WILL BE AN INCREASE IN THE MOISTURE IN THE 700 TO 850 MB COLUMN LATE THIS AFTERNOON. THE LOWEST INVERSION AROUND 900MB GOING INTO THIS MORNING IS SHOWN TO MIX OUT BUT THE ONE AROUND 700 TO 800MB WILL REMAIN ALLOWING FOR MOISTURE TO COLLECT HERE. THIS IS WHERE CLOUDS WILL DEVELOP. THERE IS UNCERTAINTY ON EXACTLY HOW MUCH CLOUDS THERE WILL BE AND THE TIMING OF THE HIGHER CLOUD COVERAGE AND THIS IS ONE PARAMETER THAT COULD FLUCTUATE WITH SUBSEQUENT FORECASTS. THE NAM AND RUC BUFKITS INDICATE THIS POSSIBILITY BUT DIFFER ON THE TIMING WHILE THE GFS BUFKITS DOES NOT MOISTEN THE 700 TO 850MB LAYER BUT IS SLOWER TO MIX OUT THE LOWEST INVERSION AROUND 900MB WITH ITS CLOUDS THIS MORNING. THE RESULTING UNCERTAINTY WAS THE REASON WHY AN EQUAL BLEND OF MAV AND MET GUIDANCE WAS CHOSEN FOR HIGH TEMPERATURES TODAY...WHICH ARE FORECAST TO BE IN THE MID TO UPPER 60S FOR A MAJORITY OF THE REGION. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... HIGH PRESSURE WILL REMAIN DOMINANT TONIGHT WITH A WEAK COLD FRONT APPROACHING FROM THE WEST AND DISSIPATING. ONLY EXPECTING AN INCREASE IN CLOUDS FROM THIS WITHIN THE 700-850MB LAYER FROM WEST TO EAST. THERE IS A LITTLE HIGHER CONFIDENCE ON MORE CLOUDS TONIGHT. HENCE...LOWS WERE PREFERRED WITH A 3/4 MET WARMER GUIDANCE TO 1/4 COOLER MAV GUIDANCE. WILL KEEP FORECAST ON THE SLOWER SIDE WITH PROGRESSION OF CLOUDS CONSIDERING THE LOWERING BOUNDARY LAYER FLOW AND LACK OF WINDS TO MIX DOWN. THIS WILL RESULT IN MORE CLOUDS FOR TONIGHT. GOING WITH A WARMER DAY TUESDAY AS THE RIDGE SHIFTS EAST AND THERE IS MORE OF A SOUTHWEST FLOW ALOFT. THERE IS SOME PRETTY GOOD LOW LEVEL WARM ADVECTION TOO WITH THE SOUTHEAST FLOW AT 850MB VEERING TO THE SOUTHWEST FLOW AT 700MB. THE WINDS ARE SLIGHTLY MORE THAN THE PREVIOUS DAY. HIGH TEMPS WERE A BLEND OF THE WARMER MET 2/3 AND COOLER 1/3 MAV CONSIDERING THE WARM AIR ADVECTION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... UPPER LEVEL RIDGE AXIS WILL SLIDE E OF THE AREA BY WED EVE WITH A TROUGH TRACKING TOWARDS THE AREA FROM THE GREAT LAKES/OHIO VALLEY REGION. THERE ARE TIMING DIFFERENCES WITH THE PROGRESSION OF THIS FIRST TROUGH WHICH HAS A RIPPLE EFFECT ON LATER PERIODS. THE GFS/GEFS MEAN IS FASTEST...FOLLOWED CLOSELY BY THE EC AND SREF...THEN THE NAM AND CMC AND LASTLY THE UKMET. HAVE STUCK WITH A MIDDLE OF THE ROAD SOLN...NAM/SREF BLEND UNTIL THIS IS BETTER RESOLVED. MEANWHILE...A BROAD UPPER LEVEL TROUGH WILL BE CARVED OUT THROUGH CENTRAL NOAM. A PROGRESSIVE PATTERN WILL DEVELOP ACROSS THE EASTERN US IN RESPONSE TO A TIGHT SW FLOW ALOFT. ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE NORTHEAST THU NIGHT/FRI...WITH YET ANOTHER NEXT WEEKEND. AT THE SFC...HIGH PRES ENTRENCHED DOWN THE APPALACHIANS WILL WEAKEN AS AN INVERTED TROUGH DEVELOPS OFF THE EAST COAST. MODELS ARE VARYING WITH THE PRONUNCIATION OF THIS FEATURE AND HOW MUCH IT WILL IMPACT THE LOCAL AREA ON WED. FOR NOW HAVE SCHC POPS ACROSS THE EAST END ALTHOUGH SOME OF THIS SYSTEMS MOISTURE MAY BE INFUSED INTO AN APPROACHING COLD FRONT AND COULD PRODUCE SOME SHOWERS WELL OUT AHEAD OF IT. HAVE THE FRONT MOVING THROUGH LATE WED NIGHT/THU MORNING...CONSISTENT WITH A NAM/SREF BLEND AS STATED ABOVE. THE PROGRESSIVE FLOW DEVELOPING ALOFT WILL ALSO BE TRANSLATED TO THE SFC. WEAK HIGH PRES RETURNS IN THE WAKE OF THE FRONT WITH LOW PRES PASSING S OF LONG ISLAND THU NIGHT OR FRI. DRY CONDITIONS THEN RETURN AGAIN FRI NIGHT INTO SAT COURTESY OF HIGH PRES BUILDING TO OUR S...BUT A WAVE OF LOW PRES DEVELOPING OVER THE GULF COAST RIDES ALONG ANOTHER COLD FRONT MARCHING TOWARDS THE AREA NEXT WEEKEND. TEMPERATURES WILL START OFF 5 TO 10 DEGREES ABOVE NORMAL...BUT WILL GRADUALLY RETURN TO SEASONABLE LEVELS IN THE LOWER TO MID 60S DURING THE DAY AND 40S...AROUND 50 IN NYC...AT NIGHT NEXT WEEKEND. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE WILL SETTLE OVER THE AREA TODAY. PATCHES OF MVFR CIGS CONTINUE...IMPACTING ABOUT HALF THE AREA. WILL CONTINUE TO MONITOR TRENDS. AMENDMENTS ARE LIKELY AS FORECASTING THESE CLOUDS REMAINS QUITE A CHALLENGE THIS MORNING. LIGHT E-NE FLOW SHOULD BECOME SE-S 5-10 KT BY AFTERNOON. IT IS UNCERTAIN EXACTLY WHERE THE HIGH PRESSURE RIDGE WILL BE ORIENTED BY LATE DAY...SO WIND DIRECTION FORECAST CONFIDENCE LOWERS LATE IN THE DAY. SPEEDS REMAIN LESS THAN 10 KT. SCT TO BROKEN CLOUDS 5 TO 10 KFT ARE ANTICIPATED LATE TODAY AND THROUGH THE EVENING AS AN APPROACHING FRONTAL BOUNDARY WEAKENS. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO S/SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KLGA FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KTEB FCSTER COMMENTS: POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KHPN FCSTER COMMENTS: POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KISP FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. OUTLOOK FOR 06Z TUE THROUGH FRI... .TONIGHT-TUE...VFR. .WED-FRI...MVFR CONDS POSSIBLE AT TIMES IN SCT SHOWERS. && .MARINE... SEAS ARE ON A SLOW DECLINE WITH WAVE HEIGHTS. HOWEVER...THERE IS STILL A 8 SEC EASTERLY SWELL WHICH WILL ENABLE FOR THE FURTHER DECREASES IN WAVE HEIGHT TO BE RATHER SLOW. WAVEWATCH IS ALSO NOW RUNNING A LITTLE LOW IN TERMS OF THE WAVE HEIGHT AT BUOY 44025. THE PRESSURE GRADIENT WILL WEAKEN CONSIDERABLY GOING INTO THE DAY SO THE SMALL CRAFT WAS CONVERTED TO ONE JUST FOR HAZARDOUS SEAS. GUSTS WILL BE LOWERING WITH CURRENT GUSTS ONLY UP TO 20 KT ON THE OCEAN. THE TIMING IS SUCH THAT THE OCEAN WEST OF MORICHES INLET WILL HAVE SMALL CRAFT CONDITIONS UNTIL 18Z WHILE EAST OF THERE...IT REMAINS UNTIL 16Z. THEREAFTER WITH WEAK PRESSURE GRADIENTS IN PLACE...SUB SCA CONDITIONS WILL BE FORECAST GOING INTO MONDAY NIGHT AND TUESDAY. A RELATIVELY WEAK FLOW WILL REMAIN ACROSS THE WATERS THROUGH THE END OF THE WEEK RESULTING IN SUB-SCA CONDS. && .HYDROLOGY... DRY WEATHER IS FORECAST THROUGH TUESDAY. GENERALLY BETWEEN 1/4 AND 1/2 INCH OF RAINFALL IS EXPECTED WITH THE COLD FRONTAL PASSAGE LATE WED NIGHT/THU MORNING. NO HYDROLOGIC ISSUES ARE ANTICIPATED WITH THIS. && .EQUIPMENT... DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM. DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353-355. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EDT TODAY FOR ANZ350. && $$ SYNOPSIS...24/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...24 AVIATION...PW MARINE...24/JM HYDROLOGY...24/JM EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
435 AM EDT MON OCT 14 2013 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE THROUGH TUESDAY...REMAINING GENERALLY NORTH AND EAST OF THE WATERS. THIS HIGH PRESSURE AREA WEAKENS TUESDAY NIGHT INTO WEDNESDAY AS IT SHIFTS INTO THE CANADIAN MARITIMES. AS HIGH PRESSURE MOVES OUT TO SEA...WEAK LOW PRESSURE WILL DEVELOP OFF THE EAST COAST WHILE A FRONTAL SYSTEM APPROACHES FROM THE GREAT LAKES. THIS SYSTEMS COLD FRONT WILL MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT OR THURSDAY MORNING. WAVES OF LOW PRESSURE ARE THEN FORECAST TO IMPACT THE AREA FRIDAY AND SATURDAY NIGHT. ANOTHER COLD FRONT MOVES THROUGH LATE SATURDAY NIGHT INTO SUNDAY MORNING. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG WILL DISSIPATE WITH DIURNAL WARMING THIS MORNING ACROSS THE INTERIOR AND RURAL AREAS. HIGH PRESSURE REMAINS STRONG...ESPECIALLY NORTH AND EAST OF THE LOCAL REGION. ALOFT...A RIDGE WILL REMAIN DOMINANT WITH ITS BASE TO OUR SOUTH. A COLD FRONT ASSOCIATED WITH AN EQUIVALENT BAROTROPIC LOW IN EASTERN CANADA WILL WEAKEN THROUGH THE DAY WITH EASTWARD MOVEMENT. THE LOSS OF TEMPERATURE ADVECTIONS WILL CONTRIBUTE TO THE WEAKENING OF THIS SYSTEM AND INHERENTLY RESULTING IN THE FRONTOLYSIS. THE ONLY EFFECT OF THE FRONT WILL BE AN INCREASE IN THE MOISTURE IN THE 700 TO 850 MB COLUMN. THE LOWEST INVERSION AROUND 900MB GOING INTO THIS MORNING IS SHOWN TO MIX OUT BUT THE ONE AROUND 700 TO 800MB WILL REMAIN ALLOWING FOR MOISTURE TO COLLECT HERE. THIS IS WHERE CLOUDS WILL DEVELOP. THE NAM AND RUC BUFKITS INDICATE THIS POSSIBILITY BUT DIFFER ON THE TIMING WHILE THE GFS BUFKITS DOES NOT MOISTEN THE 700 TO 850MB LAYER BUT IS SLOWER TO MIX OUT THE LOWEST INVERSION AROUND 900MB WITH ITS CLOUDS THIS MORNING. HIGH PRESSURE WILL REMAIN DOMINANT THROUGH TONIGHT WITH A WEAK COLD FRONT APPROACHING FROM THE WEST. ONLY EXPECTING AN INCREASE IN CLOUDS FROM THIS PARTICULARLY TOWARDS AND DURING TONIGHT. THERE IS UNCERTAINTY ON EXACTLY HOW MUCH CLOUDS THERE WILL BE AND THE TIMING OF THE HIGHER CLOUD COVERAGE AND THIS IS ONE PARAMETER THAT COULD FLUCTUATE WITH SUBSEQUENT FORECASTS. THE RESULTING UNCERTAINTY WAS THE REASON WHY AN EQUAL BLEND OF MAV AND MET GUIDANCE WAS CHOSEN FOR HIGH TEMPERATURES TODAY...WHICH ARE FORECAST TO BE IN THE MID TO UPPER 60S FOR A MAJORITY OF THE REGION. THERE IS A LITTLE HIGHER CONFIDENCE ON MORE CLOUDS TONIGHT. HENCE...LOWS WERE PREFERRED WITH A 3/4 MET WARMER GUIDANCE TO 1/4 COOLER MAV GUIDANCE. WILL KEEP FORECAST ON THE SLOWER SIDE WITH PROGRESSION OF CLOUDS CONSIDERING THE LOWERING BOUNDARY LAYER FLOW AND LACK OF WINDS TO MIX DOWN. THIS WILL RESULT IN MORE CLOUDS FOR THE LATTER PORTION OF THE DAY AND NIGHTTIME. && .SHORT TERM /TUESDAY/... GOING WITH A WARMER DAY TUESDAY AS THE RIDGE SHIFTS EAST AND THERE IS MORE OF A SOUTHWEST FLOW ALOFT. THERE IS SOME PRETTY GOOD LOW LEVEL WARM ADVECTION TOO WITH THE SOUTHEAST FLOW AT 850MB VEERING TO THE SOUTHWEST FLOW AT 700MB. THE WINDS ARE SLIGHTLY MORE THAN THE PREVIOUS DAY. HIGH TEMPS WERE A BLEND OF THE WARMER MET 2/3 AND COOLER 1/3 MAV CONSIDERING THE WARM AIR ADVECTION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... UPPER LEVEL RIDGE AXIS WILL SLIDE E OF THE AREA BY WED EVE WITH A TROUGH TRACKING TOWARDS THE AREA FROM THE GREAT LAKES/OHIO VALLEY REGION. THERE ARE TIMING DIFFERENCES WITH THE PROGRESSION OF THIS FIRST TROUGH WHICH HAS A RIPPLE EFFECT ON LATER PERIODS. THE GFS/GEFS MEAN IS FASTEST...FOLLOWED CLOSELY BY THE EC AND SREF...THEN THE NAM AND CMC AND LASTLY THE UKMET. HAVE STUCK WITH A MIDDLE OF THE ROAD SOLN...NAM/SREF BLEND UNTIL THIS IS BETTER RESOLVED. MEANWHILE...A BROAD UPPER LEVEL TROUGH WILL BE CARVED OUT THROUGH CENTRAL NOAM. A PROGRESSIVE PATTERN WILL DEVELOP ACROSS THE EASTERN US IN RESPONSE TO A TIGHT SW FLOW ALOFT. ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE NORTHEAST THU NIGHT/FRI...WITH YET ANOTHER NEXT WEEKEND. AT THE SFC...HIGH PRES ENTRENCHED DOWN THE APPALACHIANS WILL WEAKEN AS AN INVERTED TROUGH DEVELOPS OFF THE EAST COAST. MODELS ARE VARYING WITH THE PRONUNCIATION OF THIS FEATURE AND HOW MUCH IT WILL IMPACT THE LOCAL AREA ON WED. FOR NOW HAVE SCHC POPS ACROSS THE EAST END ALTHOUGH SOME OF THIS SYSTEMS MOISTURE MAY BE INFUSED INTO AN APPROACHING COLD FRONT AND COULD PRODUCE SOME SHOWERS WELL OUT AHEAD OF IT. HAVE THE FRONT MOVING THROUGH LATE WED NIGHT/THU MORNING...CONSISTENT WITH A NAM/SREF BLEND AS STATED ABOVE. THE PROGRESSIVE FLOW DEVELOPING ALOFT WILL ALSO BE TRANSLATED TO THE SFC. WEAK HIGH PRES RETURNS IN THE WAKE OF THE FRONT WITH LOW PRES PASSING S OF LONG ISLAND THU NIGHT OR FRI. DRY CONDITIONS THEN RETURN AGAIN FRI NIGHT INTO SAT COURTESY OF HIGH PRES BUILDING TO OUR S...BUT A WAVE OF LOW PRES DEVELOPING OVER THE GULF COAST RIDES ALONG ANOTHER COLD FRONT MARCHING TOWARDS THE AREA NEXT WEEKEND. TEMPERATURES WILL START OFF 5 TO 10 DEGREES ABOVE NORMAL...BUT WILL GRADUALLY RETURN TO SEASONABLE LEVELS IN THE LOWER TO MID 60S DURING THE DAY AND 40S...AROUND 50 IN NYC...AT NIGHT NEXT WEEKEND. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE WILL SETTLE OVER THE AREA TODAY. PATCHES OF MVFR CIGS CONTINUE...IMPACTING ABOUT HALF THE AREA. WILL CONTINUE TO MONITOR TRENDS. AMENDMENTS ARE LIKELY AS FORECASTING THESE CLOUDS REMAINS QUITE A CHALLENGE THIS MORNING. LIGHT E-NE FLOW SHOULD BECOME SE-S 5-10 KT BY AFTERNOON. IT IS UNCERTAIN EXACTLY WHERE THE HIGH PRESSURE RIDGE WILL BE ORIENTED BY LATE DAY...SO WIND DIRECTION FORECAST CONFIDENCE LOWERS LATE IN THE DAY. SPEEDS REMAIN LESS THAN 10 KT. SCT TO BROKEN CLOUDS 5 TO 10 KFT ARE ANTICIPATED LATE TODAY AND THROUGH THE EVENING AS AN APPROACHING FRONTAL BOUNDARY WEAKENS. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO S/SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KLGA FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KTEB FCSTER COMMENTS: POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KHPN FCSTER COMMENTS: POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KISP FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. OUTLOOK FOR 06Z TUE THROUGH FRI... .TONIGHT-TUE...VFR. .WED-FRI...MVFR CONDS POSSIBLE AT TIMES IN SCT SHOWERS. && .MARINE... SEAS ARE ON A SLOW DECLINE WITH WAVE HEIGHTS. HOWEVER...THERE IS STILL A 8 SEC EASTERLY SWELL WHICH WILL ENABLE FOR THE FURTHER DECREASES IN WAVE HEIGHT TO BE RATHER SLOW. WAVEWATCH IS ALSO NOW RUNNING A LITTLE LOW IN TERMS OF THE WAVE HEIGHT AT BUOY 44025. THE PRESSURE GRADIENT WILL WEAKEN CONSIDERABLY GOING INTO THE DAY SO THE SMALL CRAFT WAS CONVERTED TO ONE JUST FOR HAZARDOUS SEAS. GUSTS WILL BE LOWERING WITH CURRENT GUSTS ONLY UP TO 20 KT ON THE OCEAN. THE TIMING IS SUCH THAT THE OCEAN WEST OF MORICHES INLET WILL HAVE SMALL CRAFT CONDITIONS UNTIL 18Z WHILE EAST OF THERE...IT REMAINS UNTIL 16Z. THEREAFTER WITH WEAK PRESSURE GRADIENTS IN PLACE...SUB SCA CONDITIONS WILL BE FORECAST GOING INTO MONDAY NIGHT AND TUESDAY. A RELATIVELY WEAK FLOW WILL REMAIN ACROSS THE WATERS THROUGH THE END OF THE WEEK RESULTING IN SUB-SCA CONDS. && .HYDROLOGY... DRY WEATHER IS FORECAST THROUGH TUESDAY. GENERALLY BETWEEN 1/4 AND 1/2 INCH OF RAINFALL IS EXPECTED WITH THE COLD FRONTAL PASSAGE LATE WED NIGHT/THU MORNING. NO HYDROLOGIC ISSUES ARE ANTICIPATED WITH THIS. && .EQUIPMENT... DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM. DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353-355. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EDT TODAY FOR ANZ350. && $$ SYNOPSIS...24/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...24 AVIATION...PW MARINE...24/JM HYDROLOGY...24/JM EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
404 AM EDT MON OCT 14 2013 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE THROUGH TUESDAY...REMAINING GENERALLY NORTH AND EAST OF THE WATERS. THIS HIGH PRESSURE AREA WEAKENS TUESDAY NIGHT INTO WEDNESDAY AS IT SHIFTS INTO THE CANADIAN MARITIMES. AS HIGH PRESSURE MOVES OUT TO SEA...WEAK LOW PRESSURE WILL DEVELOP OFF THE EAST COAST WHILE A FRONTAL SYSTEM APPROACHES FROM THE GREAT LAKES. THIS SYSTEMS COLD FRONT WILL MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT OR THURSDAY MORNING. WAVES OF LOW PRESSURE ARE THEN FORECAST TO IMPACT THE AREA FRIDAY AND SATURDAY NIGHT. ANOTHER COLD FRONT MOVES THROUGH LATE SATURDAY NIGHT INTO SUNDAY MORNING. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG WILL DISSIPATE WITH DIURNAL WARMING THIS MORNING ACROSS THE INTERIOR AND RURAL AREAS. HIGH PRESSURE REMAINS STRONG...ESPECIALLY NORTH AND EAST OF THE LOCAL REGION. ALOFT...A RIDGE WILL REMAIN DOMINANT WITH ITS BASE TO OUR SOUTH. A COLD FRONT ASSOCIATED WITH AN EQUIVALENT BAROTROPIC LOW IN EASTERN CANADA WILL WEAKEN THROUGH THE DAY WITH EASTWARD MOVEMENT. THE LOSS OF TEMPERATURE ADVECTIONS WILL CONTRIBUTE TO THE WEAKENING OF THIS SYSTEM AND INHERENTLY RESULTING IN THE FRONTOLYSIS. THE ONLY EFFECT OF THE FRONT WILL BE AN INCREASE IN THE MOISTURE IN THE 700 TO 850 MB COLUMN. THE LOWEST INVERSION AROUND 900MB GOING INTO THIS MORNING IS SHOWN TO MIX OUT BUT THE ONE AROUND 700 TO 800MB WILL REMAIN ALLOWING FOR MOISTURE TO COLLECT HERE. THIS IS WHERE CLOUDS WILL DEVELOP. THE NAM AND RUC BUFKITS INDICATE THIS POSSIBILITY BUT DIFFER ON THE TIMING WHILE THE GFS BUFKITS DOES NOT MOISTEN THE 700 TO 850MB LAYER BUT IS SLOWER TO MIX OUT THE LOWEST INVERSION AROUND 900MB WITH ITS CLOUDS THIS MORNING. HIGH PRESSURE WILL REMAIN DOMINANT THROUGH TONIGHT WITH A WEAK COLD FRONT APPROACHING FROM THE WEST. ONLY EXPECTING AN INCREASE IN CLOUDS FROM THIS PARTICULARLY TOWARDS AND DURING TONIGHT. THERE IS UNCERTAINTY ON EXACTLY HOW MUCH CLOUDS THERE WILL BE AND THE TIMING OF THE HIGHER CLOUD COVERAGE AND THIS IS ONE PARAMETER THAT COULD FLUCTUATE WITH SUBSEQUENT FORECASTS. THE RESULTING UNCERTAINTY WAS THE REASON WHY AN EQUAL BLEND OF MAV AND MET GUIDANCE WAS CHOSEN FOR HIGH TEMPERATURES TODAY...WHICH ARE FORECAST TO BE IN THE MID TO UPPER 60S FOR A MAJORITY OF THE REGION. THERE IS A LITTLE HIGHER CONFIDENCE ON MORE CLOUDS TONIGHT. HENCE...LOWS WERE PREFERRED WITH A 3/4 MET WARMER GUIDANCE TO 1/4 COOLER MAV GUIDANCE. WILL KEEP FORECAST ON THE SLOWER SIDE WITH PROGRESSION OF CLOUDS CONSIDERING THE LOWERING BOUNDARY LAYER FLOW AND LACK OF WINDS TO MIX DOWN. THIS WILL RESULT IN MORE CLOUDS FOR THE LATTER PORTION OF THE DAY AND NIGHTTIME. && .SHORT TERM /TUESDAY/... GOING WITH A WARMER DAY TUESDAY AS THE RIDGE SHIFTS EAST AND THERE IS MORE OF A SOUTHWEST FLOW ALOFT. THERE IS SOME PRETTY GOOD LOW LEVEL WARM ADVECTION TOO WITH THE SOUTHEAST FLOW AT 850MB VEERING TO THE SOUTHWEST FLOW AT 700MB. THE WINDS ARE SLIGHTLY MORE THAN THE PREVIOUS DAY. HIGH TEMPS WERE A BLEND OF THE WARMER MET 2/3 AND COOLER 1/3 MAV CONSIDERING THE WARM AIR ADVECTION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... UPPER RIDGE OVER THE EASTERN COAST MOVES OFFSHORE TUESDAY INTO TUESDAY NIGHT AS DIGGING TROUGH FROM CENTRAL CANADA DIGS INTO THE UPPER MIDWEST AND MOVES THROUGH THE GREAT LAKES REGION. SURFACE HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST WITH THE HIGH REMAINING EAST OF THE APPALACHIANS. WITH THE SURFACE LOW WELL TO THE WEST TUESDAY NIGHT INTO WEDNESDAY...AND WARM ADVECTION RATHER WEAK...NOT EXPECTING THE WARM FRONT TO MOVE THROUGH UNTIL DURING THE DAY WEDNESDAY. SOME WEAK OVERRUNNING PRECIPITATION WILL BE POSSIBLE IN ASSOCIATION WITH WEAK ISENTROPIC LIFT. LEANED TOWARD THE NAM AND ECMWF AS THE GFS BECOMES AN OUTLIER BY WEDNESDAY...BECOMING TOO PROGRESSIVE AND WEAKER WITH THE SYSTEM. EVEN THE LIFT WITH THE COLD FRONT IS WEAK AND WILL KEEP LOW END CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY. BROAD UPPER TROUGH REMAINS ACROSS CENTRAL CANADA AND INTO THE NORTHEAST WITH A SERIES OF SHORTWAVES ROTATING THROUGH. FLOW REMAINS PROGRESSIVE THURSDAY THROUGH THE UPCOMING WEEKEND...WITH ANOTHER COLD FRONT COMING THROUGH THE REGION SATURDAY INTO SUNDAY. WITH THE PROGRESSIVE FLOW FRONTAL TIMING TOUGH TO DETERMINE AT THIS TIME. FOR WEDNESDAY THROUGH SUNDAY USED A BLEND OF THE WPC GUIDANCE AND THE ECMWF. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE WILL SETTLE OVER THE AREA TODAY. PATCHES OF MVFR CIGS CONTINUE...IMPACTING ABOUT HALF THE AREA. WILL CONTINUE TO MONITOR TRENDS. AMENDMENTS ARE LIKELY AS FORECASTING THESE CLOUDS REMAINS QUITE A CHALLENGE THIS MORNING. LIGHT E-NE FLOW SHOULD BECOME SE-S 5-10 KT BY AFTERNOON. IT IS UNCERTAIN EXACTLY WHERE THE HIGH PRESSURE RIDGE WILL BE ORIENTED BY LATE DAY...SO WIND DIRECTION FORECAST CONFIDENCE LOWERS LATE IN THE DAY. SPEEDS REMAIN LESS THAN 10 KT. SCT TO BROKEN CLOUDS 5 TO 10 KFT ARE ANTICIPATED LATE TODAY AND THROUGH THE EVENING AS AN APPROACHING FRONTAL BOUNDARY WEAKENS. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO S/SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KLGA FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KTEB FCSTER COMMENTS: POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KHPN FCSTER COMMENTS: POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. KISP FCSTER COMMENTS: TIMING OF WIND SHIFT FROM E/NE TO SE MAY BE OFF BY AN HOUR OR TWO. POSSIBLE CEILING UNDER 3 KFT AT TIMES THIS MORNING. OUTLOOK FOR 06Z TUE THROUGH FRI... .TONIGHT-TUE...VFR. .WED-FRI...MVFR CONDS POSSIBLE AT TIMES IN SCT SHOWERS. && .MARINE... SEAS ARE ON A SLOW DECLINE WITH WAVE HEIGHTS. HOWEVER...THERE IS STILL A 8 SEC EASTERLY SWELL WHICH WILL ENABLE FOR THE FURTHER DECREASES IN WAVE HEIGHT TO BE RATHER SLOW. WAVEWATCH IS ALSO NOW RUNNING A LITTLE LOW IN TERMS OF THE WAVE HEIGHT AT BUOY 44025. THE PRESSURE GRADIENT WILL WEAKEN CONSIDERABLY GOING INTO THE DAY SO THE SMALL CRAFT WAS CONVERTED TO ONE JUST FOR HAZARDOUS SEAS. GUSTS WILL BE LOWERING WITH CURRENT GUSTS ONLY UP TO 20 KT ON THE OCEAN. THE TIMING IS SUCH THAT THE OCEAN WEST OF MORICHES INLET WILL HAVE SMALL CRAFT CONDITIONS UNTIL 18Z WHILE EAST OF THERE...IT REMAINS UNTIL 16Z. THEREAFTER WITH WEAK PRESSURE GRADIENTS IN PLACE...SUB SCA CONDITIONS WILL BE FORECAST GOING INTO MONDAY NIGHT AND TUESDAY. && .HYDROLOGY... DRY WEATHER IS FORECAST THROUGH TUESDAY. && .EQUIPMENT... DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM. DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353-355. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EDT TODAY FOR ANZ350. && $$ SYNOPSIS...24/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...24 AVIATION...PW MARINE...24/JM HYDROLOGY...24/JM EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1103 PM EDT TUE OCT 15 2013 .SYNOPSIS... A HIGH PRESSURE RIDGE EXTENDING SOUTHWESTWARD INTO THE APPALACHIANS FROM NEW ENGLAND WILL SLOWLY EASE EASTWARD. A COLD FRONT FROM THE GREAT LAKES IS FORECAST TO ARRIVE LATE ON WEDNESDAY NIGHT AND STALL AS A WAVE OF LOW PRESSURE RIDES ALONG IT THROUGH OR NEAR OUR FORECAST AREA ON THURSDAY NIGHT. HIGH PRESSURE WILL LIKELY FOLLOW FOR FRIDAY INTO SATURDAY WITH ANOTHER COLD FRONT EXPECTED FOR LATE SATURDAY. THEN A HIGH PRESSURE SYSTEM FROM THE SOUTHERN ROCKIES SHOULD REACH THE MIDDLE ATLANTIC COAST ON MONDAY AND MOVE OFFSHORE ON TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... CIRRUS A BIT THICKER THAN ANTICIPATED AND NOT PERMITTING AS FAST A BL SATURATION AND MODELED BL RH IS LESS THAN 24 HOURS AGO. STILL... SCT-BKN CLOUDS IN THE 800-1400 FT LAYER ARE BECOMING MORE EVIDENT ALONG THE COAST. CONTG THE PATCHY FOG THEME LATE AND VARIABLY THICK CIRRUS SHOULD SOON SEE LAYERS OF CLOUDS BELOW 4000 FT DEVELOPING NORTHWARD DURING THE NIGHT. THE 1030 PM EARLY ESTF UPDATE...ADJUSTED SOME OF THE TEMPS OVERNIGHT...LOWERING IN N AND CENTRAL NJ. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... WARM AIR ADVECTION IS EXPECTED ON WEDNESDAY ABOVE THE FORECAST CLOUD DECK. AS A RESULT, THE CLOUDS SHOULD BE SLOW TO DISSIPATE. MOST LOCATIONS WILL REMAIN CLOUDY THROUGH THE MORNING WITH THE CLOUDS BREAKING A BIT AND LIFTING FOR THE AFTERNOON HOURS. THE SURFACE FLOW IS EXPECTED TO VEER TOWARD THE SOUTHEAST DURING THE AFTERNOON AS THE RIDGE AXIS PASSES OFF THE COAST. THE WEAK SURFACE LOW SHOULD REMAIN OFF CAPE HATTERAS. SPOTTY LIGHT RAIN SHOWERS MAY FORM ON WEDNESDAY IN THE DEVELOPING UPSLOPE FLOW, MAINLY FROM THE INTERSTATE 95 CORRIDOR NORTHWESTWARD. MAXIMUM TEMPERATURES ON WEDNESDAY SHOULD REMAIN SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE YEAR. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... NEITHER THE GFS NOR THE WRF-NMMB INITIALIZATION WAS A CLEAR VICTOR OFF THE 12Z SOUNDINGS. BOTH LOOKED BETTER IN DIFFERENT PARTS OF NOAM AND IF THERE WAS ANY CLEAR DP/DT OFF THIS RUN WAS TOWARD A FASTER SOLUTION IN THE FIRST 24 TO 48 HOURS. BEYOND THAT, THE REMAINING OF THE LONG WAVE TROF IN THE CENTRAL CONUS WOULD BEG FOR A SLOWER TIMING. ITS HALF A DOZEN OF ONE AND SIX OF THE OTHER AS FOR THIS FORECAST PACKAGE WE ARE GOING TO GO AS FAST AS THE CURRENT SOLUTION, BUT NOT TREND IT ANY FASTER. THE FIRST COLD FRONT OF THE LONG TERM WILL BE APPROACHING WEDNESDAY NIGHT. THE BEST SUPPORT FOE PRECIPITATION (CLOSEST PROXIMITY TO THE LOW LEVEL JET) AND EXIT REGION OF THE 250MB JET IS IN THE NORTHWEST PART OF OUR CWA. HIGHEST (INCLUDING LIKELY) POPS ARE THEREFORE IN THE NORTHWEST PART OF OUR CWA. CONVECTIVE SUPPORT FOR THUNDER IS PRETTY UNANIMOUSLY MODELED TO REMAIN NORTHWEST OF OUR CWA. KEPT MIN TEMPS UP TOWARD THE HIER END OF STAT GUIDANCE OWING TO THE FRONT SLOWING DOWN AND NO APPRECIABLE CLEARING BY 12Z THU. THE SLOWING/STALLING FRONT ON THURSDAY OVER OUR CWA WILL KEEP A RELATIVELY MILD AIR MASS IN PLACE. THE NEXT TRIGGER FOR PRECIPITATION SHOULD BE LATE IN ARRIVING. THE SLIGHTLY FASTER TIMING HAS US REMOVING THE MORNING POPS, BUT BRINGING LATE IN THE DAY POPS. REGARDLESS THERE APPEARS TO BE SUFFICIENT MOISTURE FORECAST TO PROBABLY PUT A DAMPER ON THE HIGHER STAT GUIDANCE FOR THE DAY. MAX TEMPS CLOSER TO LOWER STAT GUIDANCE. ALL THE MODELS ARE PRETTY CLOSE IN THE OVERALL SYNOPTIC SET-UP FOR THURSDAY NIGHT AS A JET STREAK IS FORECAST TO ENHANCE UPWARD MOTION AND PRECIPITATION ALONG THE FRONTAL BOUNDARY AS A REFLECTING SFC WAVE FORMS. IN GETTING BACK TO "NORMAL", THE WRF-NMMB IS THE LONE MODEL THAT WOULD SUPPORT THUNDER THURSDAY NIGHT IN OUR CWA. THE GLOBAL MODELS DO NOT. ATTM WE WILL NOT ADD THUNDER, BUT AT THE CONVECTIVE SUGGESTION WILL KEEP PTYPE AS SHOWERS VS RAIN. THE GFS HAS BECOME EVEN FASTER WITH THIS EVOLUTION IN SPITE OF WHAT LOOKS LIKE SOME GRID SCALE FEEDBACK INDUCED SHORT WAVES. THIS BRINGS THE AXIS OF HEAVIER RAIN FARTHER TO THE SOUTHEAST THAN THE OTHER MODELS. BECAUSE OF THAT TRIGGER, WE DID NOT GO THAT FAR AND KEPT HIGHEST POPS ALONG THE I95 CORRIDOR NORTHWESTWARD. GIVEN THE FCST PWATS HALF INCH TO INCH EVENT TOTALS ARE POSSIBLE, ALTHOUGH THIS MIGHT OCCUR NORTHWEST OF OUR CWA. FRIDAY SHOULD BE A DRY DAY. IF WE ARE WRONG, THE TIMING ERROR IS EARLY IN THE NORTHEASTERN PART OF OUR CWA. THE CONVECTIVE TEMP SHOULD BE REACHED NORTHWEST, SO SOME CAA STRATOCU THERE. THE NORTHWEST FLOW LOOKS BRISK, BUT NOT ATTM OVERTLY BRISK TO COUNTERACT THE KATABATIC FLOW. MAX TEMPS ARE CLOSE TO FULL ADIABATIC MIXING THROUGH ABOUT 900MB AND CLOSE TO STAT GUIDANCE. ON THE WEEKEND, A MOISTURE STARVED COLD FRONT IS FORECAST TO PASS THROUGH OUR CWA ABOUT SATURDAY NIGHT. WE WERE NOT AS RADIATIONALLY AGGRESSIVE WITH MIN TEMPERATURES ON SATURDAY NIGHT AS WE WERE ON FRIDAY NIGHT FOR THIS REASON. WHILE THE 00Z RUN OF THE GFS WAS THERMALLY NEAR THE WARM END OF THE GEFS SPECTRUM, THE 12Z RUN HELD COURT. OUR MAX TEMPS BOTH SATURDAY AND SUNDAY (SIMILAR SCENARIO TO FRIDAY) ARE TOWARD THIS END. A SOUTHERN ROCKIES HIGH APPROACHES ON MONDAY AND MOVES OFFSHORE TUESDAY. THE POSITIONING OF THE 500MB TROF WEST OF THE GREAT LAKES TELLS US TO NOT BUY INTO COLDER STAT GUIDANCE SOLUTIONS JUST YET BECAUSE OF THE ROUNDABOUT ARRIVAL OF THE COOLER AIR AND WE WENT ABOVE THEM. THE NEXT FRONT MIGHT ARRIVE IN TIME TO TRIGGER SHOWERS AS SOON AS TUESDAY, WHICH FOR NOW WERE SET UP IN THE GRIDS FOR TUESDAY NIGHT. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. OVERNIGHT...LIGHT NE WIND. MODELED BL MOISTURE IS LESS THAN FROM EVEN THE 18Z MODELS BUT IT STILL SUGGESTS FOG AND STRATUS...ESPECIALLY WHEN LOOKING AT 00Z/16 NAM TSEC...18Z GFS TSEC AND 01Z RUC TSEC. SREF PROBS FOR IFR CIGS ARE STILL NEAR 90 PCT BY SUNRISE AND DEVELOP WESTWARD FROM THE NJ COAST DURING THE NIGHT. ALONG THE NJ AND DE COASTS...A DECK OF SCT-BKN 800-1400 FT WAS NOTED AT 0230Z. CIRRUS IS MASKING THE FOG PRODUCT OUTPUT BENEATH THE CIRRUS BUT LOWER CIGS ARE LIKELY TO DEVELOP MANY TAF SITES BY 10Z... IN THE IFR OR MVFR CATEGORY. AS FOR VSBY...MUCH LESS CONFIDENCE REGARDING HOW THIS EVOLVES BY MORNING BUT TSECS ARE INSISTENT ON NEAR 100 PCT RH BY 12Z. THAT I AM NOT SO SURE ABOUT. SREF PROBS ARE MOST FAVORABLE FOR IFR FOG IN THE POCONOS BY MORNING. WEDNESDAY...CIGS LIFT TO VFR BY MIDDAY. WIND TURN S-SE. OUTLOOK... WEDNESDAY NIGHT...MVFR TO IFR CONDITIONS POSSIBLE MAINLY NW OF INTERSTATE 95 CORRIDOR AIRPORTS AS SCATTERED SHOWERS MOVE THROUGH. THURSDAY...MOSTLY VFR. THURSDAY NIGHT...PREDOMINATELY MVFR CONDITIONS EXPECTED. SOME IFR CONDITIONS POSSIBLE ONCE AGAIN AIRPORTS NORTHWEST OF THE INTERSTATE 95 CORRIDOR. FRIDAY THROUGH SATURDAY...MAINLY VFR. NORTHWEST WIND GUSTS EXCEEDING 20 KTS POSSIBLE FRIDAY. SATURDAY NIGHT...MAINLY VFR CIG. SUNDAY...MAINLY VFR. NORTHWEST WIND GUSTS EXCEEDING 20 KTS POSSIBLE. && .MARINE... SCA FOR SEAS IN PROGRESS NOW FOR THE S NJ AND DE COASTAL WATERS WITH THE 5-6 FT SEAS POSSIBLY LINGERING THRU 16Z. THE 6 FT SEA AT 44009 AT 02Z IS 1 FT ABOVE PREDICTED AND EXTRAPOLATING THIS AGAINST THE GUIDANCE WOULD SUGGEST AN EXTENSION THRU AT LEAST 16Z WED IS POSSIBLE. THE NNJ WATERS AND DE BAY WILL NOT NEED ANY MARINE HEADLINES THROUGH WEDNESDAY. OUTLOOK... SUB SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED THROUGHOUT THE OUTLOOK PERIOD. A PAIR OF COLD FRONTS WILL MOVE THROUGH. WINDS PRECEDING AND FOLLOWING THEM ARE EXPECTED TO COME CLOSE, BUT NOT REACH SMALL CRAFT ADVISORY CRITERIA. IF THERE WERE WINDOWS OF OPPORTUNITIES IN THE WEST TO NORTHWEST FLOW, IT WOULD BE EARLY FRIDAY AND SUNDAY DAYS. THE TIMING OF THE TIGHTEST GRADIENT IS NOT COINCIDING WITH GREATER AIR AND WATER TEMP DIFFERENTIAL FOR NOW. WE ARE SLIGHTLY MORE CONFIDENT OF SEAS NOT REACHING SMALL CRAFT ADVISORY CRITERIA AS THE STRONGEST WINDS ARE EXPECTED TO OCCUR IN THE POST COLD FRONTAL WEST TO NORTHWEST FLOW. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ452-453. SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ454-455. && $$ SYNOPSIS...GIGI/O`HARA NEAR TERM...DRAG/IOVINO/HEAVENER 1103 SHORT TERM...IOVINO LONG TERM...GIGI AVIATION...DRAG/GIGI/IOVINO/O`HARA 1103 MARINE...DRAG/GIGI/IOVINO 1103
AREA FORECAST DISCUSSION
NWS MIAMI FL
1005 PM EDT TUE OCT 15 2013 .UPDATE... THE 00Z SOUNDING INDICATED A STABLE LOCAL ATMOSPHERE WITH A WELL PRONOUNCED LOW LEVEL INVERSION. A WEAK AREA OF LOW PRESSURE ACROSS THE BAHAMAS IS PRODUCING ISOLATED SHOWERS ACROSS THE OFF SHORE ATLANTIC WATERS...BUT UPPER LEVEL SUBSIDENCE ACROSS THE REGION IS SUPPRESSING ANY SUBSTANTIAL DEVELOPMENT OF THE SHOWERS AND MAINLY ISOLATED ACTIVITY IS EXPECTED ACROSS THE ATLANTIC WATERS TONIGHT. NO SIGNIFICANT CHANGES WERE REQUIRED TO THE CURRENT FORECAST PACKAGE. 60 && .PREV DISCUSSION... /ISSUED 824 PM EDT TUE OCT 15 2013/ AVIATION... LOW PRESSURE ACROSS THE BAHAMAS CONTINUES TO SPREAD MOISTURE WESTWARD AND INTO THE OFFSHORE ATLANTIC WATERS. ASSOCIATED SHRAS ARE EXPECTED TO STAY AWAY FROM THE EAST COAST SITES THROUGH THE NIGHT. LOCAL HI RES MODELS DEPICT A FEW OF THESE SHRAS MOVING CLOSER TO THE EAST COAST SITES DURING THE DAY TOMORROW. KEPT VCSH AFTER 14Z. WINDS SHOULD BE LIGHT OVERNIGHT WITH WEAK DRAINAGE AT KAPF. EAST-NORTHEASTERLY FLOW SHOULD PREVAIL AT THE EAST COAST SITES TOMORROW AT AROUND 10 KTS WITH A GULF BREEZE DEVELOPING AT KAPF. PREV DISCUSSION... /ISSUED 231 PM EDT TUE OCT 15 2013/ SHORT TERM (TONIGHT-THURSDAY NIGHT)... VERY PROGRESSIVE MID LATITUDE PATTERN TAKING SHAPE ACROSS NORTH AMERICA WITH TWO MAJOR MID/UPPER LEVEL TROUGHS MOVING ACROSS THE NORTHERN STATES THIS PERIOD. AT THE SAME TIME, A TROUGH HAS BEEN CUT OFF OVER THE ATLANTIC NORTH OF THE BAHAMAS WITH A RIDGE ACROSS THE GULF OF MEXICO. THE ATLANTIC TROUGH WILL DRIFT SOUTH OVER THE NEXT COUPLE OF DAYS AS A STRONG RIDGE AMPLIFIES OVER THE EASTERN PACIFIC FORCING THE GULF RIDGE TO EXPAND EAST AND THE ATLANTIC TROUGH GETS PINCHED OFF FROM THE NORTHERN STREAM TROUGHS. THE ATLANTIC TROUGH HAS IN TURN, INDUCED A WEAK SURFACE TROUGH ACROSS THE BAHAMAS IN THE VICINITY OF NASSAU AND ANDROS ISLAND. THIS IS CLEARLY EVIDENT ON VISIBLE SATELLITE AND IT APPEARS TO BE DRIFTING TO THE WEST IN AN OTHERWISE WEAK SURFACE PRESSURE PATTERN IN THE AREA SURROUNDING SOUTH FLORIDA. I MENTION ALL OF THIS AS THE NAM HAS CAPTURED THIS SURFACE FEATURE MORE SO THAN THE GFS OR THE ECMWF FOR THAT MATTER. THE PROBLEM FOR AT LEAST THE FIRST PERIOD OR TWO WITH THIS FORECAST PACKAGE IS HOW MUCH AFFECT THIS TROUGH WILL HAVE ON SOUTH FLORIDA. THERE ALREADY ARE SCATTERED SHOWERS OVER THE FAR OFFSHORE ATLANTIC WATERS WITH A COUNTERCLOCKWISE MOVEMENT TO THEM AROUND THE LOWER PRESSURE. HOWEVER, THE NAM IS NOTED FOR SUFFERING FROM MESOSCALE BIAS BUT SOMETIMES PICKS UP ON THESE SMALL SCALE FEATURES WITH ITS FINER RESOLUTION BETTER THAN THE GFS. THE LATEST RUN OF THE HIGH RESOLUTION HRRR ALSO SHOWS AN INCREASE IN SHOWER ACTIVITY APPROACHING THE SOUTHEAST FLORIDA COAST LATER TONIGHT. FOR ALL OF THESE REASONS, WILL INTRODUCE SCATTERED POPS FOR THE THE SOUTHEAST COASTAL REGION FOR LATE TONIGHT AND CONTINUING INTO EARLY WEDNESDAY. IN ADDITION, DUE TO ITS MESOSCALE BIAS WILL NOT GO AS BULLISH AS THE MET GUIDANCE BUT WILL CERTAINLY GO ABOVE THE MAV NUMBERS. THE GULF OF MEXICO RIDGE WILL CONTINUE TO BUILD EAST THROUGH THURSDAY NIGHT WHICH SHOULD MAINTAIN A SUBSIDENCE CAP ACROSS THE REGION. THE NAM CONTINUES HIGH MOISTURE OVER SOUTH FLORIDA THROUGH THURSDAY NIGHT SHOWING PWAT IN THE RANGE OF 1.6-1.9 INCHES. THIS IS NO DOUBT IS OVERDONE CONSIDERING THE RIDGE SHOULD MAINTAIN A SUBSIDENCE CAP OVER SOUTH FLORIDA AND WILL REDUCE THE POPS CLOSER TO THE MAV GUIDANCE BUT AGAIN THE MAV MIGHT BE TOO LOW. ON A SIDE NOTE, THIS IS THE TIME OF THE YEAR OF ASTRONOMICAL HIGH TIDES AND THE HIGHEST TIDES ALONG THE ATLANTIC COAST WILL BE PEAKING BETWEEN THIS EVENING THROUGH THE UPCOMING WEEKEND. THIS ALSO COINCIDES WITH THE FULL MOON WHICH IS TO OCCUR ON FRIDAY. THERE WILL THEREFORE BE AN INCREASE IN SOME NUISANCE TYPE URBAN STREET FLOODING AT TIMES OF HIGH TIDE OVER THE NEXT SEVERAL DAYS POSSIBLY INTO THE EARLY NEXT WEEK ESPECIALLY ON THE BARRIER ISLANDS SUCH AS MIAMI BEACH. THE HIGH TIDES THROUGH THE END OF THIS WEEK WILL BE OCCURRING IN THE EVENING AND AGAIN EARLY IN THE MORNING. LONG TERM (FRIDAY-TUESDAY)... THE GULF RIDGE WILL MAINTAIN A PRESENCE ACROSS SOUTH FLORIDA THROUGH THE EXTENDED PERIOD. FOR THIS REASON, A COLD FRONT THAT WILL MOVE INTO THE SOUTH GULF COASTAL STATES EARLY FRIDAY, WILL STALL AND REMAIN NEARLY STATIONARY THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THIS WILL MAINTAIN A LOW LEVEL EASTERLY FLOW BUT WITH MOISTURE CONTENT REMAINING LOW. BUT STILL, THERE COULD BE SOME ISOLATED SHOWERS ESPECIALLY ALONG THE EAST COAST. MARINE... TRANQUIL WIND AND SEAS WILL CONTINUE THROUGH THE PERIOD WITH SEAS 4 FEET OR LESS. THERE COULD BE AN INCREASE IN SHOWER ACTIVITY OVER THE ATLANTIC WATERS THIS EVENING SPREADING TOWARDS THE SOUTHEAST COAST INCLUDING BISCAYNE BAY AFTER MIDNIGHT DUE TO AN APPROACHING SURFACE TROUGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 87 73 87 / 20 20 20 10 FORT LAUDERDALE 74 85 74 85 / 20 20 20 20 MIAMI 74 86 75 87 / 20 20 20 20 NAPLES 71 88 72 88 / - 20 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...10/CD AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
824 PM EDT TUE OCT 15 2013 .AVIATION... LOW PRESSURE ACROSS THE BAHAMAS CONTINUES TO SPREAD MOISTURE WESTWARD AND INTO THE OFFSHORE ATLANTIC WATERS. ASSOCIATED SHRAS ARE EXPECTED TO STAY AWAY FROM THE EAST COAST SITES THROUGH THE NIGHT. LOCAL HI RES MODELS DEPICT A FEW OF THESE SHRAS MOVING CLOSER TO THE EAST COAST SITES DURING THE DAY TOMORROW. KEPT VCSH AFTER 14Z. WINDS SHOULD BE LIGHT OVERNIGHT WITH WEAK DRAINAGE AT KAPF. EAST-NORTHEASTERLY FLOW SHOULD PREVAIL AT THE EAST COAST SITES TOMORROW AT AROUND 10 KTS WITH A GULF BREEZE DEVELOPING AT KAPF. && .PREV DISCUSSION... /ISSUED 231 PM EDT TUE OCT 15 2013/ SHORT TERM (TONIGHT-THURSDAY NIGHT)... VERY PROGRESSIVE MID LATITUDE PATTERN TAKING SHAPE ACROSS NORTH AMERICA WITH TWO MAJOR MID/UPPER LEVEL TROUGHS MOVING ACROSS THE NORTHERN STATES THIS PERIOD. AT THE SAME TIME, A TROUGH HAS BEEN CUT OFF OVER THE ATLANTIC NORTH OF THE BAHAMAS WITH A RIDGE ACROSS THE GULF OF MEXICO. THE ATLANTIC TROUGH WILL DRIFT SOUTH OVER THE NEXT COUPLE OF DAYS AS A STRONG RIDGE AMPLIFIES OVER THE EASTERN PACIFIC FORCING THE GULF RIDGE TO EXPAND EAST AND THE ATLANTIC TROUGH GETS PINCHED OFF FROM THE NORTHERN STREAM TROUGHS. THE ATLANTIC TROUGH HAS IN TURN, INDUCED A WEAK SURFACE TROUGH ACROSS THE BAHAMAS IN THE VICINITY OF NASSAU AND ANDROS ISLAND. THIS IS CLEARLY EVIDENT ON VISIBLE SATELLITE AND IT APPEARS TO BE DRIFTING TO THE WEST IN AN OTHERWISE WEAK SURFACE PRESSURE PATTERN IN THE AREA SURROUNDING SOUTH FLORIDA. I MENTION ALL OF THIS AS THE NAM HAS CAPTURED THIS SURFACE FEATURE MORE SO THAN THE GFS OR THE ECMWF FOR THAT MATTER. THE PROBLEM FOR AT LEAST THE FIRST PERIOD OR TWO WITH THIS FORECAST PACKAGE IS HOW MUCH AFFECT THIS TROUGH WILL HAVE ON SOUTH FLORIDA. THERE ALREADY ARE SCATTERED SHOWERS OVER THE FAR OFFSHORE ATLANTIC WATERS WITH A COUNTERCLOCKWISE MOVEMENT TO THEM AROUND THE LOWER PRESSURE. HOWEVER, THE NAM IS NOTED FOR SUFFERING FROM MESOSCALE BIAS BUT SOMETIMES PICKS UP ON THESE SMALL SCALE FEATURES WITH ITS FINER RESOLUTION BETTER THAN THE GFS. THE LATEST RUN OF THE HIGH RESOLUTION HRRR ALSO SHOWS AN INCREASE IN SHOWER ACTIVITY APPROACHING THE SOUTHEAST FLORIDA COAST LATER TONIGHT. FOR ALL OF THESE REASONS, WILL INTRODUCE SCATTERED POPS FOR THE THE SOUTHEAST COASTAL REGION FOR LATE TONIGHT AND CONTINUING INTO EARLY WEDNESDAY. IN ADDITION, DUE TO ITS MESOSCALE BIAS WILL NOT GO AS BULLISH AS THE MET GUIDANCE BUT WILL CERTAINLY GO ABOVE THE MAV NUMBERS. THE GULF OF MEXICO RIDGE WILL CONTINUE TO BUILD EAST THROUGH THURSDAY NIGHT WHICH SHOULD MAINTAIN A SUBSIDENCE CAP ACROSS THE REGION. THE NAM CONTINUES HIGH MOISTURE OVER SOUTH FLORIDA THROUGH THURSDAY NIGHT SHOWING PWAT IN THE RANGE OF 1.6-1.9 INCHES. THIS IS NO DOUBT IS OVERDONE CONSIDERING THE RIDGE SHOULD MAINTAIN A SUBSIDENCE CAP OVER SOUTH FLORIDA AND WILL REDUCE THE POPS CLOSER TO THE MAV GUIDANCE BUT AGAIN THE MAV MIGHT BE TOO LOW. ON A SIDE NOTE, THIS IS THE TIME OF THE YEAR OF ASTRONOMICAL HIGH TIDES AND THE HIGHEST TIDES ALONG THE ATLANTIC COAST WILL BE PEAKING BETWEEN THIS EVENING THROUGH THE UPCOMING WEEKEND. THIS ALSO COINCIDES WITH THE FULL MOON WHICH IS TO OCCUR ON FRIDAY. THERE WILL THEREFORE BE AN INCREASE IN SOME NUISANCE TYPE URBAN STREET FLOODING AT TIMES OF HIGH TIDE OVER THE NEXT SEVERAL DAYS POSSIBLY INTO THE EARLY NEXT WEEK ESPECIALLY ON THE BARRIER ISLANDS SUCH AS MIAMI BEACH. THE HIGH TIDES THROUGH THE END OF THIS WEEK WILL BE OCCURRING IN THE EVENING AND AGAIN EARLY IN THE MORNING. LONG TERM (FRIDAY-TUESDAY)... THE GULF RIDGE WILL MAINTAIN A PRESENCE ACROSS SOUTH FLORIDA THROUGH THE EXTENDED PERIOD. FOR THIS REASON, A COLD FRONT THAT WILL MOVE INTO THE SOUTH GULF COASTAL STATES EARLY FRIDAY, WILL STALL AND REMAIN NEARLY STATIONARY THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THIS WILL MAINTAIN A LOW LEVEL EASTERLY FLOW BUT WITH MOISTURE CONTENT REMAINING LOW. BUT STILL, THERE COULD BE SOME ISOLATED SHOWERS ESPECIALLY ALONG THE EAST COAST. MARINE... TRANQUIL WIND AND SEAS WILL CONTINUE THROUGH THE PERIOD WITH SEAS 4 FEET OR LESS. THERE COULD BE AN INCREASE IN SHOWER ACTIVITY OVER THE ATLANTIC WATERS THIS EVENING SPREADING TOWARDS THE SOUTHEAST COAST INCLUDING BISCAYNE BAY AFTER MIDNIGHT DUE TO AN APPROACHING SURFACE TROUGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 87 73 87 / 20 20 20 10 FORT LAUDERDALE 74 85 74 85 / 20 20 20 20 MIAMI 74 86 75 87 / 20 20 20 20 NAPLES 71 88 72 88 / - 20 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...60/BD AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 AM CDT MON OCT 14 2013 .DISCUSSION... 734 PM CDT TEMPERATURES ARE ALREADY DROPPING MUCH FASTER THAN FORECAST SO LOWERED MIN TEMPS FOR TONIGHT AND ADJUSTED TEMP TRENDS. IN ADDITION EXPANDED THE FROST ADVISORY TO INCLUDE THE FAR SOUTHERN COUNTIES IN IL AND LAKE COUNTY IL. PARTS OF INDIANA MAY SEE AREAS OF FROST TONIGHT...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE ANY INDIANA COUNTIES IN THE FROST ADVISORY. LASTLY...LOWERED SKY COVER ACROSS THE LAKE... NW INDIANA...AND NE ILLINOIS TOMORROW AS THINKING LIGHT WINDS AND THE VERY DRY AIR OVERHEAD WILL LIMIT THE CLOUD COVER. OTHERWISE THE CURRENT FORECAST IS ON TRACK. JEE //PREV DISCUSSION... 305 PM CDT THE CHALLENGES WITH THE FORECAST ARE FROST POTENTIAL TONIGHT...FOLLOWED BY MORNING CLOUDS OFF THE LAKE ON MONDAY AND THEN RAIN CHANCES TUESDAY. FINALLY THE SUBSEQUENT NOTEWORTHY COOL DOWN INTO NEXT WEEK WILL BECOME A GREATER FORECAST CHALLENGE AS THIS WEEK PROGRESSES. SYNOPSIS...EXPANSIVE 1030MB CANADIAN HIGH PRESSURE IS IN PLACE ACROSS THE UPPER MIDWEST AND WILL SHIFT DIRECTLY OVER THE AREA BY EVENING. COOL BUT MORE SEASONAL 850MB TEMPS WERE OBSERVED ACROSS THE AREA THIS MORNING...INCLUDING +3C AT DVN. ALMOST ALL 12Z GUIDANCE INITIALIZED TOO MILD WITH THIS LOW-LEVEL COOL AIR. THAT MAY BE ONE REASON WHY MOST OF THE GUIDANCE SOLUTIONS FOR TEMPS TONIGHT ARE LIKELY TOO WARM. TONIGHT...SATELLITE REVEALS THE ONLY CLOUDS IN THE IMMEDIATE REGION ARE ACROSS NORTHERN LAKE MI...AND THESE ARE IN PLACE THANKS TO THE COLD AIR MASS MOVING OVER THE STILL MILD WATERS. AS THE HIGH DOES MOVE OVER THE AREA...850-1000MB LOW WILL TURN MORE NORTHERLY AND THEN NORTHEASTERLY. SPEEDS WILL DROP BUT ARE LIKELY ENOUGH TO ADVECT LAKE-INDUCED STEEP LAPSE RATES AND SATURATION ON TOP OF THIS INDICATIVE OF STRATOCU INTO FAR NW IN AND THEN FAR NE IL AFTER MIDNIGHT. NAM AND LOCAL ARW SOUNDINGS AND LOW-LEVEL RH FIELDS ARE IN AGREEMENT TO THIS SOLUTIONS...ALONG WITH SPC WRF COLUMN CONDENSATE WHICH SEEMS TO DO WELL WITH STRATOCU IN THESE SITUATIONS. THIS WILL LIKELY SLOW OR EVEN HALT THE TEMPERATURE DROP LATE TONIGHT IN DOWNTOWN CHICAGO AND OTHER LAKE ADJACENT AREAS. FOR THE REMAINDER OF THE CWA...A PICTURE PERFECT RADIATIONAL COOLING EVENING AND OVERNIGHT IS SHAPING UP AS THE ATMOSPHERE SHOULD DECOUPLE BY EARLY TO MID EVE. HAD ADJUSTED THE HOURLY TEMPERATURE TREND TO REFLECT QUICK COOLING AFTER DARK...AND FOR MINS HAVE CONSIDERED LAST NIGHTS TEMPS STRONGLY AS A BASELINE AS OPPOSED TO ANY GUIDANCE SOURCE. THERE IS LITTLE REASON FOR OUTLYING AREAS TO BE WARMER THAN THEY WERE THIS MORNING...AND CURRENT SURFACE DEW POINTS LEAN THAT ROUTE AS WELL INDICATING THE BOUNDARY LAYER IS WELL MIXED TODAY. SO EXPECTING WIDESPREAD 32 TO 35 ACROSS NORTH CENTRAL IL WITH MID TO UPPER 30S ELSEWHERE IN OUTLYING AREAS. CONSIDERING COCORAHS OBSERVER COMMENTS THIS MORNING REPORTING PATCHY FROST...WOULD EXPECT CLOSER TO A WIDESPREAD FROST IN NORTH CENTRAL IL. CONSIDERING THE MILD NIGHT AS OF RECENT...WE HAVE GONE AHEAD AND COLLABORATED A FROST ADVISORY FOR LATE TONIGHT...THE FIRST SUCH ADVISORY OF THE SEASON. MONDAY...THE HIGH WILL REMAIN IN CONTROL ON COLUMBUS DAY. THE LAKE EFFECT CLOUDS ARE ANTICIPATED TO LINGER IN NORTHEAST IL...POSSIBLY AS FAR WEST AS NORTH CENTRAL IL...BUT AMOUNT OF COVERAGE IS LOW CONFIDENCE. THE CLOUD DEPTH LOOKS TO BE AT OR UNDER 3K FT AT MOST OVER THE LAKE SO ANY STRATOCU MAY BEGIN TO THIN QUICKLY BY LATE MORNING. MIXING LOOKS TO BE TO 875MB...AND THAT SHOULD SUPPORT 60S ACROSS THE AREA. TUESDAY AND WEDNESDAY...A PRONOUNCED UPPER TROUGH ACROSS UT/NV WILL SHIFT ENE INTO THE UPPER MIDWEST DURING THIS PERIOD...AND THIS WILL BE THE FIRST OF MULTIPLE UPPER WAVES EVOLVING EASTWARD ACROSS NORTH AMERICA DURING THE MIDDLE OF THIS WEEK. TOGETHER THESE WILL CARVE OUT A LONG WAVE TROUGH OVER THE CENTRAL PART OF THE CONTINENT...EXTENDING INTO THE MIDWEST BY WEEKS END. THIS FIRST WAVE ON TUESDAY LOOKS TO BRING THE BEST CHANCE OF RAIN TO THE AREA AS PRONOUNCED HEIGHT FALLS MOVE ACROSS THE AREA ALONG WITH DYNAMIC SUPPORT FOR ENHANCED LIFT AHEAD OF THE SYSTEM COOL FRONT. THE GFS REMAINS THE QUICKEST SOLUTION WITH THIS...BUT NOT BY MUCH AT ALL. THE MEAN OF THE SOLUTIONS PAINTS THE MORNING AND EARLY AFTERNOON WILL BE THE BEST CHANCE FOR WIDESPREAD SHOWERS AS THE MOISTURE TRANSPORT MAX POINTS INTO THE REGION. AS THE COLD FRONT SHIFTS EASTWARD THROUGH THE AREA LIKELY DURING TUESDAY AFTERNOON...THIS MAY PRESENT A BETTER CHANCE FOR THUNDER. INSTABILITY RETURN LOOKS TO BE VERY MODEST AT BEST...ESPECIALLY IF THERE IS MORNING WIDESPREAD CLOUDS AND RAIN. THE DRY SLOT STILL LOOKS TO EVOLVE OVER TUE NIGHT WITH ANY PRECIP LIKELY TO BE LIGHT AT THAT POINT. COLD AIR ADVECTION WRAPS AROUND THIS SYSTEM AND PREVAILS ON WED WITH HIGHS 10 TO 15 DEGREES COOLER THAN TUE. SMALL CHANCES FOR SHOWERS ARE IN WEDNESDAY AS THE COLD CORE SYSTEM MOVES OVERHEAD. THURSDAY AND BEYOND...THE SUCCESSIVE SHORT WAVE TROUGHS WILL LEAD TO PROGRESSIVE THICKNESS FALLS AND COOLING TEMPS. THE 850 0C ISOTHERM DROPS SOUTH INTO THE AREA ON FRIDAY IN THE GFS/EC MEAN SOLUTION WITH AN ASSOCIATED COLD FRONT. THIS SETS THE STAGE FOR THE FIRST POSSIBLE WIDESPREAD FREEZE ON FRIDAY OR SATURDAY NIGHT IF INDEED HIGH PRESSURE FOLLOWS WHICH IT LOOKS TO. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * POTENTIAL FOR A PERIOD OF HIGH-END MVFR CIGS VERY LATE TONIGHT/EARLY THIS MORNING. * LIGHT NORTH/VARIABLE WIND OVERNIGHT BECOMING EAST THIS MORNING. MDB //DISCUSSION...UPDATED 06Z... HIGH PRESSURE CENTERED ACROSS WISCONSIN WILL SHIFT EASTWARD THROUGH TODAY. THE WEAK PRESSURE GRADIENT HAS ALLOWED WINDS TO BECOME CALM/LIGHT AND VARIABLE ACROSS MOST OF THE AREA. A WEAK LAND BREEZE IS SETTING UP BASED ON OBS NEAR LAKE MICHIGAN WHICH IS PROVIDING LIGHT NORTH TO NORTHWEST WINDS AT ORD/MDW. SKIES ARE CLEAR AWAY FROM LAKE MICHIGAN BUT LAKE EFFECT STRATUS HAS BEEN DEVELOPING OVER THE SOUTH END OF THE LAKE. AT THIS POINT BASES LOOK TO BE IN THE 3000-4000 FT RANGE BUT MAY SEE SOME LOWERING AS COVERAGE INCREASES AND LAND AREAS COOL FURTHER. THESE CLOUDS ARE ALSO EXPECTED TO SPREAD INLAND OVER THE CHICAGO METRO TOWARD MORNING. WILL CONTINUE WITH SCATTERED LOW END VFR CLOUD MENTION AT ORD/MDW FOR NOW BUT BKN PERIODS ARE POSSIBLE FOR SEVERAL HOURS LATE THIS MORNING. WILL CARRY BKN LOW END VFR CIGS AT GYY. ONCE THE SUN RISES THE LAND BREEZE WILL FADE AND A LARGER SCALE LIGHT EAST TO EAST-SOUTHEAST WIND WILL TAKE OVER ACROSS THE AREA. EXPECT THAT THE LAKE CLOUD COVER WILL DISSIPATE WITH TIME INTO LATE AFTERNOON. WINDS WILL TURN SOUTHEASTERLY THIS EVENING WITH STEADY OR EVEN INCREASING SPEEDS TONIGHT AS LOW PRESSURE MOVES NORTHEAST FROM THE CENTRAL PLAINS. MDB //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM CONFIDENCE IN SCT-BKN CLOUDS ARRIVING LATE TONIGHT/EARLY THIS MORNING...LOW CONFIDENCE IF THEY WILL BE MVFR. * HIGH CONFIDENCE IN WIND TRENDS. MDB //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...SHRA/FEW TSRA LIKELY. MVFR POSSIBLE. WEDNESDAY...CHANCE SHRA. MVFR POSSIBLE. THURSDAY...VFR. FRIDAY AND SATURDAY...SLIGHT CHANCE SHRA. MAINLY VFR. RATZER && .MARINE... 225 PM CDT WINDS WILL VEER TO OUT OF THE NORTH AND NORTHEAST AND DIMINISH TONIGHT AS HIGH PRESSURE CENTERED OVER NORTHWEST IOWA AT MID AFTERNOON BUILDS ACROSS THE UPPER MIDWEST AND UPPER GREAT LAKES DURING THE NIGHT. AS THE HIGH CONTINUES ON ACROSS ONTARIO TO SOUTHERN QUEBEC MONDAY AND MONDAY NIGHT LOW PRESSURE WILL BE ORGANIZING OVER THE CENTRAL HIGH PLAINS AND DEEPENING AS IT MOVES NORTHEASTWARD TO SOUTHERN MINNESOTA. WITH THE WESTERN GREAT LAKES BETWEEN THE DEPARTING HIGH AND THE APPROACHING STRENGTHENING LOW WINDS ON LAKE MICHIGAN INCREASE TO MODERATE AND FRESH BREEZES WHILE VEERING TO OUT OF THE SOUTHEAST AND SOUTH DURING MONDAY NIGHT AND TUESDAY. THE LOW MOVES ACROSS NORTHERN WISCONSIN AND THE EASTERN UPPER PENINSULA OF MICHIGAN TUESDAY NIGHT AND WEDNESDAY. AS IT DOES IT WILL PUSH A COLD FRONT EASTWARD ACROSS LAKE MICHIGAN. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FROST ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ019-ILZ020-ILZ021-ILZ023-ILZ032-ILZ033- ILZ039 UNTIL 8 AM MONDAY. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1106 PM CDT Sun Oct 13 2013 .DISCUSSION... ISSUED 815 PM CDT Sun Oct 13 2013 In the process of updating the ZFP this evening to include a Frost Advisory for areas mainly north of a Lewistown to Bloomington line. Early morning temperatures are expected to drop into the middle 30s across the north for a time Monday morning allowing frost to form, especially away from the metropolitan areas of Peoria and Bloomington. Further south, have added some patchy frost for early Monday morning. Early evening temperatures were dropping off rapidly with readings already in the middle 40s across the far north (Galesburg and Lacon). The latest HRRR model suggests the threat for a more prolonged period of calm winds north of I-74 in the 09z-12z time frame as the center of the high will shift just north of our area. Early evening dew points have settled into the lower to middle 30s and that usually gives us a good idea where the early morning low may dip to with this type of radiational cooling setup, especially in low lying areas and in locations away from the city. Have edged the overnight lows down a degree or two further south and as mentioned above, added some patchy frost as well, but the best threat for our first frost of the season will be mainly north of I-74 early Monday morning. The updated zones should be out by 0145z. && .AVIATION... ISSUED 1105 PM CDT Sun Oct 13 2013 VFR conditions are expected through this forecast period (06z Tue). High pressure will drift well to our north tonight into Monday morning allowing a light northeast flow to prevail. A clear sky can be expected into the early afternoon hours of Monday before high level clouds increase ahead of the next weather system slated to affect our area just after this forecast period. Surface winds on Monday will veer slightly into an east-southeast direction at around 10 kts. Smith && .PREV DISCUSSION... ISSUED 249 PM CDT Sun Oct 13 2013 After collaboration with DVN and LOT, have added patchy frost to areas across the northwest forecast area and made some minor adjustments to other grids for late tonight and early Monday morning. Do not expect frost to be widespread enough to warrant an advisory, but wind protected areas may see some patchy frost. && .ILX WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY from 3 AM to 8 AM CDT Monday FOR ILZ027>031- 036>038. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
600 PM CDT Tue Oct 15 2013 ...UPDATE TO AVIATION... .SHORT TERM...(This evening through Wednesday) ISSUED AT 153 PM CDT TUE OCT 15 2013 To start off with, I deliberated over low temperatures quite a bit for tonight, and the resultant freeze and frost hazards. Model guidance varies quite a bit, and this difference seems to be centered around how fast some mid and high clouds will intrude. Have settled upon using the HRRR and RUC models, which are a bit cooler than then NAM, ECMWF, and GFS models. In the end, there could be a small area that freezes tonight in our northwest zones, namely Trego, Ellis, Scott, Lane and Ness counties, where a freeze warning will be posted from 4 am to 9 am CDT. The 32F degree mark may be tricky in Scott county, if the mid level clouds get there before the diurnal cooling off occurs, they may hit 33F or 34F very briefly around 09-10Z. To the south, surrounding the Freeze Warning, mid 30s seem likely and a frost advisory is in place from 4 am to 9 am CDT, with widespread frost mentioned. Even one more tier of counties southward will have patchy frost mentioned late, but without an advisory. Down along most of the Oklahoma state boundary, clouds will be entering there sooner, and thus lows in the upper 30s will extend along most of that stretch. An upper wave, open in nature, will cross from New Mexico into southeast Kansas on Wednesday. The upper synoptic lift may be just enough to kick off a few rain showers across our southern half of the CWA, but only slight chances seem justified since no surface boundary is present, and the lower layers will be cool. With clouds, some scattered showers, and cold air advection, max temps will struggle to get out of the 50s. Current forecast max temps range from 57F in Syracuse, to 60F in Medicine Lodge. I did not change the forecast highs, as they seemed reasonable. The other weather parameter worth noting is winds will not be too strong, as they have been of late. The high pressure will produce northwest winds around 10 mph in the morning, which will shift to the west by afternoon, still blow in the 10 to 15 mph range. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 316 PM CDT TUE OCT 15 2013 Relatively dry and sunny conditions are expected Thursday due to transient mid level shortwave ridging. Cold temperatures in the mid to upper 30`s are most likely during the morning while abundant insolation should allow warming into the 60`s by early afternoon. a sharp mid to upper level baroclinic zone associated with a strongly positively tilted trough and 300 mb level polar will jet have create sensible weather impacts for Friday. As the upper trough approaches and sharpens by Friday morning, the mid level baroclinic zone will strengthen causing frontogenesis and associated lift ageostrophic lifting. GFS is very similar to the ECMWF with respect to most mass fields with this system, and shows a continuously sloping intense frontogenetic profile from above 850 mb level near medicine lodge to near 500 mb across NW Kansas. This cold system aloft appears warm enough in the boundary layer to expect phase change to all rain at the surface. GFS and GEM are the coldest of the models, only allowing for temperatures to reach the upper 40`s across western Kansas by the afternoon. Precipitation chances have been increased to the likely category for Friday morning with a rapid tapering in the afternoon as the upper trough transitions to a subsident northwest flow across central Kansas by Friday night. Saturday morning will have potential to be cold again (even with frost) if winds and clearing conditions are favorable, but yet uncertain considering it is still at a 96 hour forecast timestep. The remainder of the forecast period through early next week is for and only slowly moderating surface temperatures toward normal for mid October, as northwest flow aloft becomes established aloft and high pressure dominates the central Rockies into the southern plains. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) ISSUED AT 600 PM CDT TUE OCT 15 2013 VFR conditions will prevail at all TAF sites through late Wednesday morning. As for winds, surface high pressure in eastern Wyoming will slide southeast along the Rocky Mountain Front Range into the Western High Plains of Colorado and western Kansas tonight. This will result in northwesterly winds of 15 to 25kt early this evening subsiding below 15kt overnight while winds become more westerly toward early Wednesday morning. && .PRELIMINARY POINT TEMPS/POPS... DDC 34 58 38 65 / 0 20 10 10 GCK 34 58 35 64 / 0 20 10 10 EHA 36 57 37 64 / 10 30 0 10 LBL 36 58 37 66 / 10 30 0 10 HYS 32 59 37 63 / 0 10 10 10 P28 38 60 40 67 / 0 20 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY from 4 AM CDT /3 AM MDT/ to 9 AM CDT /8 AM MDT/ Wednesday FOR KSZ046-061>064. FREEZE WARNING from 4 AM to 9 AM CDT Wednesday FOR KSZ030-031- 043>045. && $$ SHORT TERM...Burke LONG TERM...Russell AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS WICHITA KS
308 PM CDT MON OCT 14 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 304 PM CDT MON OCT 14 2013 THIS EVENING-TNGT: MOST OF THE WRN HALF OF THE FORECAST AREA REMAINS IN THE DRY SLOT AHEAD OF THE MAIN COLD AND LINE OF CONVECTION CURRENTLY WEST OF KHYS. WITH WARM ADVECTION SHOWERS CONTINUING OVER THE FLINT HILLS AND SOUTHEAST KS. BUT EXPECT RENEWED CONVECTION IN CEN KS AS THE FRONTAL BOUNDARY AND CONVECTION OVER NW KS MOVES SLOWLY E-SE AS THE LATE AFTN CONTINUES. LATEST RAP OUTPUT SHOWS SFC BASED INSTABILITY CONTINUES TO BE LACKING...ONLY AROUND 1800 J/KG FOR AREAS JUST ALONG OR AHEAD OF THE MAIN DRY LINE/COLD FRONTAL BOUNDARY WHERE CLOUDS HAVE THINNED OUT. BUT BULK SHEAR LOOKS TO MAKE UP FOR THIS...WITH IMPRESSIVE BULK SHEAR VALUES OF 50-70KTS. SO COULD SEE A LOW TOPPED LINE CONVECTION MOVE INTO CEN KS FOR THE LATE AFTN/EARLY EVENING HOURS. IMPRESSIVE SHEAR WILL PROBABLY MAKE UP FOR LOWER INSTABILITY VALUES FOR AT LEAST A SMALL SEVERE EVENT IN CEN KS WITH STRONG STORMS MORE LIKELY. NOT TOO IMPRESSED WITH THE ISOLATED TORNADO THREAT (GIVEN BY SPC) THIS FAR SOUTH...AS NOT A CLASSIC COLD CORE SETUP...GIVEN VERTICAL STRETCHING WILL BE LIMITED...UNLESS CLOUDS CAN THIN ENOUGH JUST AHEAD OF THE BOUNDARY/DRYLINE TRIPLE POINT EXPECTED ACROSS CEN KS. SO THINK A VERY SMALL WINDOW OF OPPORTUNITY EXISTS FOR ANY KIND OF TORNADO/FUNNEL...PROBABLY NORTH OF THE FORECAST AREA IN NRN KS. MORE OF A LOW TOPPED LINE WITH QUARTER HAIL AND DAMAGING WIND THE MAIN CONCERNS. EXPECT THIS LINE OF CONVECTION TO MAKE PROGRESS SLOWLY EAST- SOUTHEAST ACROSS THE FORECAST DURING THE EVENING HOURS. LATEST HRRR SEEMS TO HAVE A NICE HANDLE ON HOW THIS SYSTEM WILL PLAY OUT...WITH A THIN LINE OF CONVECTION EXPECTED TO PUSH SLOWLY ACROSS THE AREA. ALSO THINK THE WINDOW OF OPPORTUNITY FOR SEVERE STORMS WILL DIMINISH QUICKLY AFTER SUNSET...WITH THE LOSS OF DAYTIME HEATING AND COOLING OF THE BOUNDARY LAYER. SO MAIN SEVERE THREAT WILL PROBABLY BE WEST OF I-135 GIVEN THE TIMING. TUE-THU: EXPECT THE COLD FRONT TO PUSH SOUTH AND EAST OF THE AREA EARLY ON TUE...WITH SOME LINGERING SHOWERS POSSIBLE ACROSS SOUTHEAST KANSAS. THE MAIN CONCERN FOR TUE-THU WILL BE THE COOLER THAN NORMAL TEMPS AS A CANADIAN RIDGE OF HIGH PRESSURE DROPS SOUTH OUT OF WRN CANADA INTO THE PLAINS. THIS COULD POSSIBLY LEAD TO SOME PATCHY FROST ESPECIALLY OVER CEN KS FOR WED MORNING...AS THE RIDGE AXIS WILL BE OVER THE AREA. WILL SEE ANOTHER MID LEVEL SHORTWAVE MOVE OUT OF THE ROCKIES INTO THE PLAINS FOR THE DAYTIME HOURS ON WED INTO WED EVE. THIS SHORTWAVE WILL MOVE ACROSS THE AREA AS THE SFC RIDGE REMAINS OVER THE REGION....SO LOW LEVEL MOISTURE WILL BE LIMITED AS IT COMES ACROSS. BOTH THE GFS/ECMWF HINT AT SOME VERY LOW POPS AS IT MOVES ACROSS...BUT GFS FORECAST SOUNDINGS SUGGEST MORE OF A SPRINKLE CHANCE FOR MAINLY SOUTHERN KS GIVEN THE DRY LOW LAYERS. KETCHAM .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 304 PM CDT MON OCT 14 2013 MEDIUM RANGE MODELS SHOW THE NEXT FRONTAL BOUNDARY EXPECTED TO DROP SOUTH ACROSS KS FOR LATE THU NIGHT INTO EARLY ON FRI. BOTH THE GFS/ECMWF TRYS TO BRING THE LOW LEVEL MOISTURE BACK TOWARDS KS BY FRI...AHEAD OF THIS FRONT...BUT TIMING OF THE FRONT SUGGESTS THE BETTER MOISTURE WILL STAY CONFINED TO EXTREME SRN KS OR OK. COULD SEE SOME 850-700H MOISTURE RIDE OVER THE TOP OF THE BOUNDARY FOR A POSSIBLE POST FRONTAL SHOWER/STORM CHANCE...ESPECIALLY ACROSS SRN KS. SO FOR CONSENSUS SAKE...WILL KEEP A LOW POP FOR THIS CHANCE. COOLER THAN NORMAL TEMPS LOOK TO CONTINUE FOR WEEKEND AS SERIES OF FRONTAL BOUNDARY CONTINUE TO KEEP THE WARMER TEMPS SHUNTED FURTHER TO THE SOUTH. KETCHAM && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1242 PM CDT MON OCT 14 2013 THE MAIN AVIATION FORECAST CONCERN IS THE OFF AND ON SHOWERS/THUNDERSTORMS THIS AFTERNOON AND LOW MVFR TO IFR CEILINGS. LOW CEILINGS ARE MOVING INTO THE AREA FROM THE WEST THIS AFTERNOON AND HAVE UPDATED TO DROP ALL CEILINGS TO IFR...EITHER IN A PREVAILING GROUP OR IN A TEMPO. EXPECTING IFR TO LOW MVFR TO PERSIST INTO THE EVENING HOURS. SOUTHERLY WINDS WILL CONTINUE TO BE BREEZY AHEAD OF THE FRONTAL PASSAGE THIS EVENING. THE COLD FRONT/DRY LINE IS EXPECTED TO PUSH EASTWARD LATE THIS AFTERNOON INTO THE EARLY EVENING HOURS. EXPECTING A LINE OF CONVECTION TO MOVE THROUGH THE AREA WITH IT AND HAVE TIMED CURRENT TAFS FOLLOWING GUIDANCE FROM THE LATEST HRRR AND NAM. THIS CONVECTIVE LINE IS NOT ANTICIPATED TO LINGER AT ANY ONE PLACE VERY LONG BEFORE IT MOVES ON TO THE SOUTHEAST. WINDS WILL BECOME NORTHWESTERLY AND BREEZY BEHIND THE FRONT. AS THE FRONT MOVES THROUGH CEILINGS ARE EXPECTED TO LIFT TO VFR. BILLINGS WRIGHT && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 47 62 39 61 / 60 10 10 10 HUTCHINSON 45 60 38 61 / 60 10 10 10 NEWTON 46 60 37 59 / 60 10 10 10 ELDORADO 48 62 39 60 / 60 10 10 10 WINFIELD-KWLD 49 64 41 61 / 60 10 10 10 RUSSELL 40 58 34 58 / 70 0 0 10 GREAT BEND 40 59 33 59 / 70 0 0 10 SALINA 44 60 36 61 / 70 10 10 10 MCPHERSON 45 60 36 60 / 70 10 10 10 COFFEYVILLE 52 64 43 60 / 80 20 10 20 CHANUTE 51 63 42 60 / 70 10 10 10 IOLA 50 63 42 59 / 70 10 10 10 PARSONS-KPPF 52 64 42 60 / 80 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1242 PM CDT MON OCT 14 2013 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 226 AM CDT MON OCT 14 2013 CURRENT SATELLITE WATER VAPOR IMAGERY SHOWS A HEALTHY UPPER LEVEL WAVE CENTERED NEAR THE FOUR CORNERS REGION WITH A EASTWARD MOVEMENT ACROSS THE ROCKIES. WE SHOULD SEE A ROUND OF SCATTERED TO NUMEROUS ELEVATED SHOWERS/STORMS DEVELOP AHEAD OF THIS WAVE DURING THE MORNING/AFTERNOON HOURS. MEANWHILE...RICHER LOW LEVEL MOISTURE NOW OVER CENTRAL OKLAHOMA WILL CONTINUE TO STREAM NORTHWARD IN ADVANCE OF THE APPROACHING COLD FRONT ACROSS WESTERN AND CENTRAL KANSAS TODAY. STRONG CONVERGENCE AND UPPER DYNAMICS IN CONJUNCTION WITH THIS COLD FRONT WILL INITIATE ANOTHER ROUND OF THUNDERSTORMS OVER WESTERN KANSAS THIS AFTERNOON. THIS ACTIVITY WILL SPREAD EASTWARD INTO CENTRAL KANSAS BY LATE AFTERNOON AND EVENING. A FEW STRONG TO SEVERE LOW-TOPPED THUNDERSTORMS ARE POSSIBLE GIVEN VERY STRONG SHEAR ALOFT AND DAYTIME HEATING BOOSTING THE INSTABILITY...MAINLY FOR LOCATIONS WEST OF I-135. THE STORMS WILL WEAKEN SHORTLY AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING AND COOLING OF THE BOUNDARY LAYER. OTHERWISE BELOW NORMAL TEMPERATURES WILL PREVAIL FOR TUE/WED AS SURFACE HIGH PRESSURE AND ASSOCIATED COOL AIRMASS SETTLES OVER KANSAS. ANOTHER UPPER LEVEL WAVE WILL MOVE ACROSS THE AREA ON WEDNESDAY BUT DRY LOW LEVELS SHOULD KEEP MOST AREAS DRY...PERHAPS A FEW SPRINKLES OR LIGHT RAIN SHOWERS FOR SOUTHERN KANSAS. .LONG TERM...(THURSDAY THROUGH SUNDAY) ISSUED AT 226 AM CDT MON OCT 14 2013 DEEP UPPER TROUGHING WITH NORTHWEST FLOW WILL PREVAIL OVER THE CENTRAL PLAINS THIS PERIOD WHICH SHOULD RESULT IN COOLER TEMPERATURES. RAIN CHANCES WILL BE LIMITED WITH THIS WEATHER PATTERN SO WILL ONLY CARRY SOME SMALL PRECIPITATION CHANCES FOR THE FRIDAY/FRIDAY NIGHT PERIOD ACROSS SOUTHERN KANSAS. JAKUB && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1242 PM CDT MON OCT 14 2013 THE MAIN AVIATION FORECAST CONCERN IS THE OFF AND ON SHOWERS/THUNDERSTORMS THIS AFTERNOON AND LOW MVFR TO IFR CEILINGS. LOW CEILINGS ARE MOVING INTO THE AREA FROM THE WEST THIS AFTERNOON AND HAVE UPDATED TO DROP ALL CEILINGS TO IFR...EITHER IN A PREVAILING GROUP OR IN A TEMPO. EXPECTING IFR TO LOW MVFR TO PERSIST INTO THE EVENING HOURS. SOUTHERLY WINDS WILL CONTINUE TO BE BREEZY AHEAD OF THE FRONTAL PASSAGE THIS EVENING. THE COLD FRONT/DRY LINE IS EXPECTED TO PUSH EASTWARD LATE THIS AFTERNOON INTO THE EARLY EVENING HOURS. EXPECTING A LINE OF CONVECTION TO MOVE THROUGH THE AREA WITH IT AND HAVE TIMED CURRENT TAFS FOLLOWING GUIDANCE FROM THE LATEST HRRR AND NAM. THIS CONVECTIVE LINE IS NOT ANTICIPATED TO LINGER AT ANY ONE PLACE VERY LONG BEFORE IT MOVES ON TO THE SOUTHEAST. WINDS WILL BECOME NORTHWESTERLY AND BREEZY BEHIND THE FRONT. AS THE FRONT MOVES THROUGH CEILINGS ARE EXPECTED TO LIFT TO VFR. BILLINGS WRIGHT && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 68 47 63 40 / 80 60 10 10 HUTCHINSON 68 45 61 39 / 90 60 10 10 NEWTON 66 46 62 39 / 80 60 10 10 ELDORADO 66 48 63 40 / 80 60 10 10 WINFIELD-KWLD 68 49 65 41 / 100 60 10 10 RUSSELL 70 40 58 35 / 100 70 0 0 GREAT BEND 69 40 59 37 / 100 70 0 0 SALINA 68 44 60 38 / 90 70 10 10 MCPHERSON 67 45 60 39 / 100 70 10 10 COFFEYVILLE 69 52 65 44 / 100 70 20 10 CHANUTE 68 51 64 42 / 100 70 10 10 IOLA 68 50 63 42 / 100 70 10 10 PARSONS-KPPF 68 52 64 43 / 100 70 20 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1238 PM CDT Mon Oct 14 2013 ...Update to short term and aviation forecasts... .UPDATE... Issued at 1202 PM CDT MON OCT 14 2013 Weak elevated instability is in place across much of the area early this afternoon with substantial forcing for ascent providing several areas of showers and thunderstorms across Kansas. This will lead to periods of rain and thunder this afternoon and evening with the entire area likely to see rain at some point as well as dry periods. Morning model guidance and observations remain consistent in the development of an area of surface based instability 500 to 1500 J/kg developing in western and central KS this afternoon immediately in advance of the incoming cold front/dryline. This instability will rapidly decrease between 00Z and 03Z, with less than 200 J/kg in advance of the front after 03Z. Deep layer wind shear is strong, and low level shear is rather impressive as well, but not sure if the minimal instability in the local area will allow the wind shear to be fully utilized. It seems that 2 or more lines of convection may steadily move through the narrow warm sector west of the area this afternoon, but will likely congeal into a single line as it approaches the forecast area and the cold front becomes the primary focus for forcing. Currently expect this main line of storms to enter the NW corner of the forecast area around 7 PM, into Manhattan area by 10 PM, and into the Topeka area around midnight before moving out of the area by 4 AM. As previously mentioned, the instability decreases to near zero after 10 PM, and thus expect severe weather to be limited to areas west of Manhattan, although there are occasionally situations in high shear environments during which the lift along a front is sufficient to support a low end severe threat even after instability dissipates. Stronger downdrafts and bowing segments with damaging wind would seem to be the primary severe weather hazard, especially given the strong winds through the lower atmosphere associated with this storms system. There also seems to be a small potential for tornadoes, mainly near and west of Highway 81 where the instability may actually support updraft rotation at times. The overall severe threat in the forecast area is low...but non-zero. && .SHORT TERM...(Today and Tonight) Issued at 403 AM CDT MON OCT 14 2013 Confidence on the specifics of when and where best coverage of precipitation will be over the next 24 hours is not high, but the overall setup is for a widespread wet event over much of the Central Plains. 00Z upper jet structure showed southern branch from central Baja into Kansas with northern branch south and east around the Great Basin upper low then northeast into the Four Corners, and this will push east through tonight with persistent diffluence over Kansas resulting. Deep moisture will steadily increase with stronger mid level flow initially leading to better isentropic lift there (ongoing in central portions of the state) and then somewhat lower as the day progresses and 850 mb winds increase to near 60 kt around 00Z. Elevated creeps up as well for an increasing thunder concern pushing east with time. Have generally indicated the most likely wet periods from mid morning through early evening from west to east, close to the WRF-ARW and recent HRRR runs which seem to be handling the overnight convection the best. They are also similar with surface-based storms breaking out in the KHLC vicinity in the late afternoon hours as the mid level dry slot works northeast and cold front surges east. With plenty of shear, CAPE will be the main limiting factor with this activity maintaining itself through north central Kansas, but at least minor concern for severe hail and wind potential exist in western areas. Cold front sweeps through overnight with clearing and drying taking over. High temperature details are also difficult with onset and duration of daytime precip and continued late-day south winds coinciding with some potential dry periods in the west possibly leading to max values around 0Z. .LONG TERM...(Tuesday through Sunday) Issued at 403 AM CDT MON OCT 14 2013 Drier air will move into eastern Kansas in the wake of the frontal boundary and upper level system on Tuesday. Surface high pressure will build into eastern Kansas Tuesday night and Wednesday keeping winds rather light and temperatures below normal. GFS and ECMWF move an upper trough across the plains Wednesday and Wednesday night. Forecast soundings show dry air in the low and mid levels will be present keeping chances of any measurable precipitation to the south of the CWA. Cannot rule out a few sprinkles south of I-35 though. Models continue to offer differing solutions for Friday through the weekend. The ECMWF has been inconsistent while the GFS has been more consistent on a run to run basis. The ECMWF is much sharper and further south with the mid level trough while the GFS maintains a ridge in the eastern Pacific and northwest flow across the Plains with a broad upper low over Ontario into the Ohio Valley through the weekend. However the ECMWF brings another shortwave trough across Kansas Saturday. Given the differences in the models and limited moisture availability, will go with a dry forecast at this time and will wait and see what later model runs provide. Highs will mainly be in the 60s with lows in the 30s and 40s. && .AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon) Issued at 1202 PM CDT MON OCT 14 2013 Periods of showers and embedded thunderstorms will impact TAF sites through this afternoon. Should see predominant MVFR conditions through 00Z, but with a few breaks to VFR possible. MVFR will likely lower to IFR around 01Z at MHK although with some potential to occur sooner. Cigs should stay above 1000 feet at TOP/FOE. A cold front will likely arrive at MHK near 03Z and TOP/FOE near 05Z with a period of IFR conditions and TS. A brief period of strong TS winds will be possible as well. Colder drier air brings VFR and northwest winds after the frontal passage. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barjenbruch SHORT TERM...65 LONG TERM...53 AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
NWS TOPEKA KS
652 AM CDT Mon Oct 14 2013 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 403 AM CDT MON OCT 14 2013 Confidence on the specifics of when and where best coverage of precipitation will be over the next 24 hours is not high, but the overall setup is for a widespread wet event over much of the Central Plains. 00Z upper jet structure showed southern branch from central Baja into Kansas with northern branch south and east around the Great Basin upper low then northeast into the Four Corners, and this will push east through tonight with persistent diffluence over Kansas resulting. Deep moisture will steadily increase with stronger mid level flow initially leading to better isentropic lift there (ongoing in central portions of the state) and then somewhat lower as the day progresses and 850 mb winds increase to near 60 kt around 00Z. Elevated creeps up as well for an increasing thunder concern pushing east with time. Have generally indicated the most likely wet periods from mid morning through early evening from west to east, close to the WRF-ARW and recent HRRR runs which seem to be handling the overnight convection the best. They are also similar with surface-based storms breaking out in the KHLC vicinity in the late afternoon hours as the mid level dry slot works northeast and cold front surges east. With plenty of shear, CAPE will be the main limiting factor with this activity maintaining itself through north central Kansas, but at least minor concern for severe hail and wind potential exist in western areas. Cold front sweeps through overnight with clearing and drying taking over. High temperature details are also difficult with onset and duration of daytime precip and continued late-day south winds coinciding with some potential dry periods in the west possibly leading to max values around 0Z. .LONG TERM...(Tuesday through Sunday) Issued at 403 AM CDT MON OCT 14 2013 Drier air will move into eastern Kansas in the wake of the frontal boundary and upper level system on Tuesday. Surface high pressure will build into eastern Kansas Tuesday night and Wednesday keeping winds rather light and temperatures below normal. GFS and ECMWF move an upper trough across the plains Wednesday and Wednesday night. Forecast soundings show dry air in the low and mid levels will be present keeping chances of any measurable precipitation to the south of the CWA. Cannot rule out a few sprinkles south of I-35 though. Models continue to offer differing solutions for Friday through the weekend. The ECMWF has been inconsistent while the GFS has been more consistent on a run to run basis. The ECMWF is much sharper and further south with the mid level trough while the GFS maintains a ridge in the eastern Pacific and northwest flow across the Plains with a broad upper low over Ontario into the Ohio Valley through the weekend. However the ECMWF brings another shortwave trough across Kansas Saturday. Given the differences in the models and limited moisture availability, will go with a dry forecast at this time and will wait and see what later model runs provide. Highs will mainly be in the 60s with lows in the 30s and 40s. && .AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning) Issued at 652 AM CDT MON OCT 14 2013 Radar trends not far off from short range models with convection becoming more widespread near and upstream of the terminals. Only made a few alterations to going forecast, delaying initial onset of nearby TSRA but then going down to MVFR conditions in especially low clouds a bit earlier. Cold front sweeps through late in the forecast with VFR conditions returning. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...65 LONG TERM...53 AVIATION...65
AREA FORECAST DISCUSSION
NWS TOPEKA KS
403 AM CDT Mon Oct 14 2013 .SHORT TERM...(Today and Tonight) Issued at 403 AM CDT MON OCT 14 2013 Confidence on the specifics of when and where best coverage of precipitation will be over the next 24 hours is not high, but the overall setup is for a widespread wet event over much of the Central Plains. 00Z upper jet structure showed southern branch from central Baja into Kansas with northern branch south and east around the Great Basin upper low then northeast into the Four Corners, and this will push east through tonight with persistent diffluence over Kansas resulting. Deep moisture will steadily increase with stronger mid level flow initially leading to better isentropic lift there (ongoing in central portions of the state) and then somewhat lower as the day progresses and 850 mb winds increase to near 60 kt around 00Z. Elevated creeps up as well for an increasing thunder concern pushing east with time. Have generally indicated the most likely wet periods from mid morning through early evening from west to east, close to the WRF-ARW and recent HRRR runs which seem to be handling the overnight convection the best. They are also similar with surface-based storms breaking out in the KHLC vicinity in the late afternoon hours as the mid level dry slot works northeast and cold front surges east. With plenty of shear, CAPE will be the main limiting factor with this activity maintaining itself through north central Kansas, but at least minor concern for severe hail and wind potential exist in western areas. Cold front sweeps through overnight with clearing and drying taking over. High temperature details are also difficult with onset and duration of daytime precip and continued late-day south winds coinciding with some potential dry periods in the west possibly leading to max values around 0Z. .LONG TERM...(Tuesday through Sunday) Issued at 403 AM CDT MON OCT 14 2013 Drier air will move into eastern Kansas in the wake of the frontal boundary and upper level system on Tuesday. Surface high pressure will build into eastern Kansas Tuesday night and Wednesday keeping winds rather light and temperatures below normal. GFS and ECMWF move an upper trough across the plains Wednesday and Wednesday night. Forecast soundings show dry air in the low and mid levels will be present keeping chances of any measurable precipitation to the south of the CWA. Cannot rule out a few sprinkles south of I-35 though. Models continue to offer differing solutions for Friday through the weekend. The ECMWF has been inconsistent while the GFS has been more consistent on a run to run basis. The ECMWF is much sharper and further south with the mid level trough while the GFS maintains a ridge in the eastern Pacific and northwest flow across the Plains with a broad upper low over Ontario into the Ohio Valley through the weekend. However the ECMWF brings another shortwave trough across Kansas Saturday. Given the differences in the models and limited moisture availability, will go with a dry forecast at this time and will wait and see what later model runs provide. Highs will mainly be in the 60s with lows in the 30s and 40s. && .AVIATION...(For the 06Z TAFs through 06Z Monday Night) Issued at 1149 PM CDT SUN OCT 13 2013 Not much change to prior fcst as moisture surges northward across the terminals overnight with stratocu deck thickening/lowering to around 3500 feet by 11-13z time frame with some convection in the vcnty. As the main axis of deeper moisture advects northward and large scale lifts increases, showers and thunderstorms will increase west to east across the terminals aft 16z with lowering cigs to mvfr thru 00z. East southeasterly winds generally 5 to 8kts will increase aft 12z with gusts aoa 20kts through the end of the fcst period...although a gradual veering and decrease in speeds may occur aft 02z/15 as front approaches. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...65 LONG TERM...53 AVIATION...63
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1030 AM EDT MON OCT 14 2013 .SYNOPSIS... A WEAKENING COLD FRONT WILL MOVE ACROSS THE REGION THIS AFTERNOON INTO THIS EVENING. ANOTHER AREA OF HIGH PRESSURE WILL APPROACH FROM THE WEST TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... 1030 AM UPDATE...HAVE SENT ANOTHER QUICK UPDATE TO INCREASE POPS ACROSS THE NORTH THIS MORNING, AS A BATCH OF LIGHT TO OCCASIONALLY MODERATE RAIN IS MAKING ITS WAY EASTWARD ACROSS AROOSTOOK COUNTY. ALSO BUMPED UP POPS TO 40-50% IN CENTRAL MAINE AS THE HRRR AND RUC/RAP CONTINUE TO SHOW A BAND OF RAIN MAKING IN THERE THIS AFTERNOON. GIVEN THE LOW CLOUDS AND FOG THAT STILL PLAGUE NORTHERN MAINE, ALSO TWEAKED HIGH TEMPS DOWN A COUPLE OF DEGREES, AS WELL. NO OTHER CHANGES NEEDED. PREVIOUS DISCUSSION...HIGH PRESSURE IS CURRENTLY DRIFTING TO THE SOUTH OF THE STATE AS A WEAK COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT IS EXPECTED TO MOVE THROUGH DURING THE DAY MONDAY. THIS MAY RESULT IN SOME SHOWERS OVER THE WESTERN AREAS BUT EXPECT THE FRONT TO WEAK AS IT MOVES THROUGH. FOR POPS AND QPF HAVE BLENDED THE NAM12 GFS40 ...SREF AND THE ECMWF. TEMPERATURE AND DEW POINT GRIDS GENERATED WITH THE BIAS CORRECTED CONSENSUS ALL. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... HIGH PRES WILL MOVE ACROSS THE REGION ON TUESDAY AND PASS OFF TO THE E ON WEDNESDAY. A FRONTAL SYSTEM WILL MOVE TOWARD THE REGION ON WEDNESDAY W/INCREASING CLOUDS AND SHOWERS BY LATER IN THE DAY. AOA NORMAL DAYTIME TEMPERATURES ARE EXPECTED FOR TUESDAY W/SUN AND CLOUDS. STAYED PRETTY CLOSE TO THE DAYCREW`S ASSESSMENT OF UPPER 50S TO AROUND 60 NORTH AND WEST AND LOWER 60S CENTRAL AND DOWNEAST. WEDNESDAY LOOKS TO A MOSTLY CLOUDY DAY FOR THE MOST PART W/THE RISK FOR SHOWERS BY THE AFTERNOON ESPECIALLY FOR THE WESTERN AREAS AS WELL AS THE INTERIOR DOWNEAST AND THE COAST WHERE THE BEST FORCING WILL BE SITUATED. THE LATEST RUNS OF THE GFS AND ECMWF ARE IN VERY GOOD AGREEMENT W/THIS SETUP AS NOW IS THE CANADIAN GLOBAL. THEREFORE, CHANGES WERE MADE TO THE PRECIP CHANCES ESPECIALLY ACROSS THE DOWNEAST AND COAST(RAISED TO 60%) AS A DISTURBANCE LIFTS NORTHWARD AHEAD OF THE APCHG FRONTAL BOUNDARY TO THE WEST. THERE DOES APPEAR TO BE ENOUGH MID LEVEL FORCING(700 MBS) TO SUPPORT THE RAMP UP IN THE PRECIP CHANCES. NORTH-CENTRAL AREAS COULD ACTUALLY GET AWAY RAIN FREE UNTIL WEDNESDAY EVENING AS THIS REGION WILL BE BETWEEN THE 2 FEATURES. TEMPERATURES ON WEDNESDAY ARE FCST TO BE MORE IN LINE W/NORMAL READINGS FOR MID OCTOBER. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... PRECIP CHANCES WILL INCREASE WEDNESDAY NIGHT ON INTO THURSDAY AS THE FRONTAL BOUNDARY MOVES ACROSS THE REGION FROM THE WEST. CONFIDENCE IS HIGH ENOUGH TO RAISE THE PRECIP CHANCES UP TO 60-70% W/STRONG LLVL CONVERGENCE AND GOOD MID LEVEL FORCING. THE DECISION WAS TO KEEP THE WX ELEMENT AS RAIN FOR THIS FCST CYCLE FOLLOWING THE DAYCREW`S LEAD. THERE IS SOME CONCERN FOR POSSIBLE CONVECTION LATER WEDNESDAY NIGHT INTO EARLY THURSDAY. THE ECMWF AND GFS SHOW DECENT LLVL WARMING TAKING HOLD FOR THIS TIMEFRAME W/SOME DECENT UPPER LEVEL DIFLUENCE. THE 00Z RUN OF THE ECMWF IS MORE PRONOUNCED W/THIS SETUP THAN THE 00Z GFS. THE CANADIAN GLOBAL TO SOME EXTENT INDICATED THIS AS WELL. THE DRAWBACK IS TWO FOLD. ONE IS THAT THE LLVLS WILL BE STABLE DUE TO A SSE FLOW AND TWO, THE MODELS ESPECIALLY THE GFS, HAVE BACKED AWAY FROM THE CONVECTIVE POTENTIAL(SUCH AS SBCAPE AND TOTAL TOTALS) THAT THEY WERE SHOWING 24 HR AGO. THEREFORE, DECIDED TO LEAVE THE MENTION OF TSTMS OUT FOR THIS CYCLE AND WOULD LIKE TO SEE HOW THINGS UNFOLD AS WE CLOSE IN ON THE EVENT. THE OVERALL PATTERN LOOKS LIKE IT WILL CONTINUE TO BE PROGRESSIVE AS THIS SYSTEM WILL MOVE ON OUT OF THE CWA BY THURSDAY NIGHT W/PARTIAL CLEARING SLATED FOR FRIDAY. MUCH COOLER WEATHER IS EXPECTED BEHIND THIS SYSTEM W/DAYTIME TEMPERATURES ON FRIDAY ACTUALLY NEAR NORMAL. THIS COOLER WEATHER IS EXPECTED TO CONTINUE RIGHT INTO THE WEEKEND W/ANOTHER FRONTAL BOUNDARY FCST TO BRING SOME SHOWERS ON SATURDAY. STAYED CLOSE TO THE DAYCREW`S ASSESSMENT OF NEAR NORMAL TEMPERATURES INTO THE WEEKEND. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... NEAR TERM: MVFR/IFR IN FOG THIS MORNING THEN VFR CONDITIONS EXPECTED TODAY AND TONIGHT. SHORT TERM: VFR INTO EARLY WEDNESDAY AND THEN CONDITIONS ARE FCST TO DROP TO MVFR WEDNESDAY AFTERNOON AND THEN IFR WEDNESDAY NIGHT INTO THURSDAY FOR ALL TERMINALS. LIFR CONDITIONS ARE POSSIBLY ESPECIALLY ON THURSDAY W/THE FROPA. && .MARINE... NEAR TERM: HAVE USED THE NAM12 TO GENERATE SUSTAINED WIND GRIDS. FOR WAVES: WITH HIGH PRESSURE OVER THE WATERS EXPECT LIGHT WINDS EARLY TODAY WITH PRIMARY SEAS CONSISTING OF SOUTHERLY LONG PERIOD WAVES AROUND 2 FEET/8 SECONDS. WAVE MODEL SPECTRA DEPICTING THIS GROUP WELL ALTHOUGH GROUP WAVE HEIGHTS ARE A LITTLE LOW ON 0000Z WAVE WATCH RUN. LATER TODAY SOUTHERLY WIND WAVE (1-2 FEET/3-4 SECONDS) COMBINES WITH SWELL AND PERSISTS INTO TONIGHT. SHORT TERM: NO HEADLINES ANTICIPATED. WINDS WILL PICK IN ADVANCE OF THE APCHG FRONTAL SYSTEM ON THURSDAY AND DECIDED TO BRING SUSTAINED WINDS TO 10-15 KTS. WAVE HEIGHTS AREA FCST TO CLIMB TO 5 FT W/THE POTENTIAL FOR A SWELL AHEAD OF THE FRONT. THERE IS THE POSSIBILITY THAT THE SWELL COULD REACH 6 FT OVER THE OUTER WATERS BY LATER WEDNESDAY IN THAT SWELL. ATTM, KEPT WAVE HEIGHTS AT 5 FT AND THIS SURGE LOOKS TO BE SHORT LIVED. STILL TIME TO ASSESS THIS W/THE LATER GUIDANCE. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HASTINGS/MIGNONE SHORT TERM...HEWITT LONG TERM...HEWITT AVIATION...HASTINGS/MIGNONE/HEWITT MARINE...HASTINGS/MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
912 AM EDT MON OCT 14 2013 .SYNOPSIS... A WEAKENING COLD FRONT WILL MOVE ACROSS THE REGION THIS AFTERNOON INTO THIS EVENING. ANOTHER AREA OF HIGH PRESSURE WILL APPROACH FROM THE WEST TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... 910 AM UDATE...FOG IS STARTING TO SLOWLY LIFT THIS MORNING, THOUGH WE ARE STILL SOCKED IN HERE IN CARIBOU AND A FEW OTHER LOCATIONS ACROSS NORTHERN AROOSTOOK COUNTY. HOWEVER, MOST OF THE DENSE FOG HAS LIFTED, SO ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 9 AM. THE OTHER CONCERN FOR THIS UPDATE IS THE SHOWERS THAT ARE ASSOCIATED WITH AN APPROACHING COLD FRONT. THE LATEST HI-RES MODELS, INCLUDING THE HRRR AND RUC/RAP, INDICATE THAT THE BATCH OF RAIN CURRENTLY MOVING ACROSS VERMONT AND NORTHERN NEW YORK WILL MOVE NEARLY DIRECTLY EAST INTO CENTRAL AND PORTIONS OF DOWNEAST MAINE BY THIS AFTERNOON. HAVE UPDATED POPS ACCORDINGLY, INTRODUCING ISOLATED/SCATTERED SHOWERS IN THESE AREAS. WILL HAVE TO WATCH RADAR TRENDS CAREFULLY, AS THESE RAIN CHANCES MAY HAVE TO BE EXTENDED EVEN FURTHER SOUTH IN LATER UPDATES. REGARDLESS, DON`T EXPECT MUCH MORE THAN A TENTH OF AN INCH TO FALL IN MOST SPOTS, THOUGH ISOLATED HIGHER AMOUNTS ARE POSSIBLE ACROSS THE HIGHER TERRAIN IN THE NORTH MAINE WOODS. PREVIOUS DISCUSSION...HIGH PRESSURE IS CURRENTLY DRIFTING TO THE SOUTH OF THE STATE AS A WEAK COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT IS EXPECTED TO MOVE THROUGH DURING THE DAY MONDAY. THIS MAY RESULT IN SOME SHOWERS OVER THE WESTERN AREAS BUT EXPECT THE FRONT TO WEAK AS IT MOVES THROUGH. FOR POPS AND QPF HAVE BLENDED THE NAM12 GFS40 ...SREF AND THE ECMWF. TEMPERATURE AND DEW POINT GRIDS GENERATED WITH THE BIAS CORRECTED CONSENSUS ALL. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... HIGH PRES WILL MOVE ACROSS THE REGION ON TUESDAY AND PASS OFF TO THE E ON WEDNESDAY. A FRONTAL SYSTEM WILL MOVE TOWARD THE REGION ON WEDNESDAY W/INCREASING CLOUDS AND SHOWERS BY LATER IN THE DAY. AOA NORMAL DAYTIME TEMPERATURES ARE EXPECTED FOR TUESDAY W/SUN AND CLOUDS. STAYED PRETTY CLOSE TO THE DAYCREW`S ASSESSMENT OF UPPER 50S TO AROUND 60 NORTH AND WEST AND LOWER 60S CENTRAL AND DOWNEAST. WEDNESDAY LOOKS TO A MOSTLY CLOUDY DAY FOR THE MOST PART W/THE RISK FOR SHOWERS BY THE AFTERNOON ESPECIALLY FOR THE WESTERN AREAS AS WELL AS THE INTERIOR DOWNEAST AND THE COAST WHERE THE BEST FORCING WILL BE SITUATED. THE LATEST RUNS OF THE GFS AND ECMWF ARE IN VERY GOOD AGREEMENT W/THIS SETUP AS NOW IS THE CANADIAN GLOBAL. THEREFORE, CHANGES WERE MADE TO THE PRECIP CHANCES ESPECIALLY ACROSS THE DOWNEAST AND COAST(RAISED TO 60%) AS A DISTURBANCE LIFTS NORTHWARD AHEAD OF THE APCHG FRONTAL BOUNDARY TO THE WEST. THERE DOES APPEAR TO BE ENOUGH MID LEVEL FORCING(700 MBS) TO SUPPORT THE RAMP UP IN THE PRECIP CHANCES. NORTH-CENTRAL AREAS COULD ACTUALLY GET AWAY RAIN FREE UNTIL WEDNESDAY EVENING AS THIS REGION WILL BE BETWEEN THE 2 FEATURES. TEMPERATURES ON WEDNESDAY ARE FCST TO BE MORE IN LINE W/NORMAL READINGS FOR MID OCTOBER. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... PRECIP CHANCES WILL INCREASE WEDNESDAY NIGHT ON INTO THURSDAY AS THE FRONTAL BOUNDARY MOVES ACROSS THE REGION FROM THE WEST. CONFIDENCE IS HIGH ENOUGH TO RAISE THE PRECIP CHANCES UP TO 60-70% W/STRONG LLVL CONVERGENCE AND GOOD MID LEVEL FORCING. THE DECISION WAS TO KEEP THE WX ELEMENT AS RAIN FOR THIS FCST CYCLE FOLLOWING THE DAYCREW`S LEAD. THERE IS SOME CONCERN FOR POSSIBLE CONVECTION LATER WEDNESDAY NIGHT INTO EARLY THURSDAY. THE ECMWF AND GFS SHOW DECENT LLVL WARMING TAKING HOLD FOR THIS TIMEFRAME W/SOME DECENT UPPER LEVEL DIFLUENCE. THE 00Z RUN OF THE ECMWF IS MORE PRONOUNCED W/THIS SETUP THAN THE 00Z GFS. THE CANADIAN GLOBAL TO SOME EXTENT INDICATED THIS AS WELL. THE DRAWBACK IS TWO FOLD. ONE IS THAT THE LLVLS WILL BE STABLE DUE TO A SSE FLOW AND TWO, THE MODELS ESPECIALLY THE GFS, HAVE BACKED AWAY FROM THE CONVECTIVE POTENTIAL(SUCH AS SBCAPE AND TOTAL TOTALS) THAT THEY WERE SHOWING 24 HR AGO. THEREFORE, DECIDED TO LEAVE THE MENTION OF TSTMS OUT FOR THIS CYCLE AND WOULD LIKE TO SEE HOW THINGS UNFOLD AS WE CLOSE IN ON THE EVENT. THE OVERALL PATTERN LOOKS LIKE IT WILL CONTINUE TO BE PROGRESSIVE AS THIS SYSTEM WILL MOVE ON OUT OF THE CWA BY THURSDAY NIGHT W/PARTIAL CLEARING SLATED FOR FRIDAY. MUCH COOLER WEATHER IS EXPECTED BEHIND THIS SYSTEM W/DAYTIME TEMPERATURES ON FRIDAY ACTUALLY NEAR NORMAL. THIS COOLER WEATHER IS EXPECTED TO CONTINUE RIGHT INTO THE WEEKEND W/ANOTHER FRONTAL BOUNDARY FCST TO BRING SOME SHOWERS ON SATURDAY. STAYED CLOSE TO THE DAYCREW`S ASSESSMENT OF NEAR NORMAL TEMPERATURES INTO THE WEEKEND. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... NEAR TERM: MVFR/IFR IN FOG THIS MORNING THEN VFR CONDITIONS EXPECTED TODAY AND TONIGHT. SHORT TERM: VFR INTO EARLY WEDNESDAY AND THEN CONDITIONS ARE FCST TO DROP TO MVFR WEDNESDAY AFTERNOON AND THEN IFR WEDNESDAY NIGHT INTO THURSDAY FOR ALL TERMINALS. LIFR CONDITIONS ARE POSSIBLY ESPECIALLY ON THURSDAY W/THE FROPA. && .MARINE... NEAR TERM: HAVE USED THE NAM12 TO GENERATE SUSTAINED WIND GRIDS. FOR WAVES: WITH HIGH PRESSURE OVER THE WATERS EXPECT LIGHT WINDS EARLY TODAY WITH PRIMARY SEAS CONSISTING OF SOUTHERLY LONG PERIOD WAVES AROUND 2 FEET/8 SECONDS. WAVE MODEL SPECTRA DEPICTING THIS GROUP WELL ALTHOUGH GROUP WAVE HEIGHTS ARE A LITTLE LOW ON 0000Z WAVE WATCH RUN. LATER TODAY SOUTHERLY WIND WAVE (1-2 FEET/3-4 SECONDS) COMBINES WITH SWELL AND PERSISTS INTO TONIGHT. SHORT TERM: NO HEADLINES ANTICIPATED. WINDS WILL PICK IN ADVANCE OF THE APCHG FRONTAL SYSTEM ON THURSDAY AND DECIDED TO BRING SUSTAINED WINDS TO 10-15 KTS. WAVE HEIGHTS AREA FCST TO CLIMB TO 5 FT W/THE POTENTIAL FOR A SWELL AHEAD OF THE FRONT. THERE IS THE POSSIBILITY THAT THE SWELL COULD REACH 6 FT OVER THE OUTER WATERS BY LATER WEDNESDAY IN THAT SWELL. ATTM, KEPT WAVE HEIGHTS AT 5 FT AND THIS SURGE LOOKS TO BE SHORT LIVED. STILL TIME TO ASSESS THIS W/THE LATER GUIDANCE. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HASTINGS/MIGNONE SHORT TERM...HEWITT LONG TERM...HEWITT AVIATION...HASTINGS/MIGNONE/HEWITT MARINE...HASTINGS/MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1000 PM EDT TUE OCT 15 2013 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY PUSH OFF THE NEW ENGLAND COAST TONIGHT...AS A TROUGH OF LOW PRESSURE REMAINS ANCHORED OFF THE NORTH CAROLINA COAST. A COLD FRONT WILL APPROACH FROM THE WEST WEDNESDAY EVENING INTO THURSDAY...WITH A WAVE OF LOW PRESSURE TRACKING ALONG THE FRONT AND PUSHING THROUGH THE MID ATLANTIC REGION THURSDAY EVENING THROUGH EARLY FRIDAY MORNING. WEAK HIGH PRESSURE BUILDS TO THE NORTH OF THE AREA BY FRIDAY AFTERNOON. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE LATEST SURFACE ANALYSIS DEPICTS A ~1025MB SURFACE HIGH PRESSURE CENTERED OVER NOVA SCOTIA. MEANWHILE...A 1013MB SURFACE LOW REMAINS CENTERED OFF CAPE HATTERAS. CURRENT SURFACE OBSERVATIONS INDICATE 0.8-1.5K FT CIGS ACROS MOST OF THE AREA WITH THE EXCEPTION OF THE PIEDMONT WHERE CIGS ARE ~3K FT. MOSTLY CLOUDY TO OVERCAST CONDITIONS ARE EXPECTED TO CONTINUE OVERNIGHT WITH STRATUS LOWERING THROUGH THE NIGHT. GIVEN THE AMOUNT OF CLOUD COVER FOG IS NOT EXPECTED...BUT 2-4SM VSBY IS EXPECTED LATER TONIGHT INTO EARLY MORNING. A 20% POP WILL BE MAINTAINED THIS EVENING/OVERNIGHT NEAR THE COAST. WENT A BIT ABOVE GUIDANCE FOR MINS TONIGHT DUE TO LOW STRATUS. LOWS IN THE LOWER-MID 60S IMMEDIATE SE VA/NE NC COAST TO THE MID 50S ACRS THE FAR WEST (MOST AREAS SHOULD SEE MINS IN THE UPPER 50S/AROUND 60F). && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... LIGHT FLOW ALOFT BY DAYBREAK WED WILL GRADUALLY INCREASE LATER WED/THU AS A SERIES OF SHORTWAVES TRACK THROUGH THE GREAT LAKES. WITH MOSTLY CLOUDY/CLOUDY SKIES EARLY ON WED...IT MAY BE DIFFICULT TO SCOUR OUT THE LOW LEVEL MOISTURE. SINCE BOTH THE GFS/NAM BUFKIT SOUNDINGS DO SUGGEST AT LEAST PARTIAL CLEARING BY LATE MORNING/EARLY AFTN...DID NOT KEEP IT CLOUDY ALL DAY...GENLY DROPPING SKY COVER TO BKN CONDITIONS BY AFTN. WENT COOLER THAN GUIDANCE BY ABOUT 2-5 DEGREES DUE TO THE LIGHT FLOW AND POTENTIAL CLOUDS (AND WITH THE WINDS STAYING ONSHORE NEAR THE COAST). THIS YIELDS HIGH MAINLY IN THE LOWER-MID 70S. A STRAY LIGHT SHOWER WILL BE POSSIBLE BUT KEPT POPS CAPPED AT 14% AS VIRTUALLY NO FORCING WILL BE PRESENT. A SLIGHT INCREASE IN THE PRESSURE GRADIENT WED NIGHT/THU MAY OFFSET INCREASING DEEP LAYER MOISTURE TO HAVE SKIES AVG PARTLY CLOUDY RATHER THAN MOSTLY CLOUDY...ESPECIALLY E OF I-95. STILL STAYED COOLER THAN MAV/MET NUMBERS FOR HIGHS THU WHICH ARE GENLY IN THE 80-85 DEGREE RANGE (THINK 75-80 IS MORE LIKELY). BEST CHC FOR PRECIP LOOKS TO OCCUR THU NIGHT...MAINLY OVER THE FAR NW/N ZONES WHERE GFS/NAM SHOW THE BEST LIFT AND MOISTURE CONVERGENCE. STILL A LOT OF UNCERTAINTY AND MANY AREAS MAY RECEIVE LITTLE TO NO QPF AS MAIN UPPER SUPPORT/DYNAMICS STAY WELL TO OUR N/W. AS FOR POPS WENT WITH 30-40% CHANCES MOST AREAS...WITH A NARROW ZONE OF 60% POPS OVER THE FAR N/NW. SKIES CLEAR OUT FROM N TO S FRI MORNING...BUT THINK THE GFS IS TOO FAST AT SHOWING THIS GIVEN CONTINUED WSW/SW FLOW ALOFT. THE HIGH THAT BUILDS TO THE NORTH MAY NOT BE STRONG ENOUGH TO EVEN CLEAR OUT FAR SE ZONES FRI BUT WILL GO W/ PARTLY SUNNY SKIES DOWN THERE FOR NOW. HIGHS IN THE UPPER 60S TO LOWER 70S FRI. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LATEST GFS/NAM/ECMWF BUILD A WEAK AREA OF HIGH PRESSURE OVER THE REGION FRIDAY NIGHT AND EARLY SATURDAY KEEPING MOST IF NOT ALL MOISTURE SOUTH OF FA. THIS HIGH RETREATS OFFSHORE LATE SATURDAY ALLOWING THE SOUTHERN MOISTURE TO DRIFT BACK NORTH A BIT. SO HAVE DROPPED POPS MOST AREAS ON SATURDAY...EXCEPT ALONG AND SOUTH OF VA RT 58 WHERE I KEPT SLGHT CHC POPS. CHILLY FRIDAY NIGHT WITH LOWS IN THE 40S EXCEPT 50-55 ALONG COASTAL SECTIONS. HIGHS SATURDAY M60S-L70S. WEAK WAVE OF LOW PRESSURE PROGGED TO DEVELOP ALONG THE STALLED COASTAL FRONTAL BOUNDARY SATURDAY NIGHT BEFORE MOVING INTO THE VA CAPES SUNDAY. TSCTNS AND MOISTURE FIELDS SHOW ENOUGH SUPPORT FOR LOW CHC POPS ACROSS SERN ZONES AND A BUFFER ZONE ON SLGHT CHC POPS FURTHER NW SATURDAY NIGHT. PCPN THEN SHIFTS TO THE SERN ZONES SUNDAY BEFORE ENDING AS THE LOW PULLS FURTHER OFFSHORE. LOWS SATURDAY NIGHT IN THE M40S-M50S. HIGHS SUNDAY IN THE 60S. HIGH PRESSURE BUILDS OVER THE REGION EARLY NEXT WEEK BRINGING DRY BUT COOLER CONDITIONS TO THE REGION. HIGHS BOTH DAYS 65-70. COOLEST SUNDAY NIGHT UNDER SKIES CLEAR. LOWS U30S NWRN COUNTIES TO L-M50S SERN COASTAL AREAS. LOWS MONDAY NIGHT IN THE 40S TO L50S. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... OBSERVATIONS ARE SHOWING A STRATUS DECK OF CLOUDS ROTATING IN FROM THE OCEAN. THIS IS ASSOCIATED WITH LOW PRESSURE OFF THE NORTH CAROLINA COAST. THESE CLOUDS WILL COVER ALL THE TAF SITES BY MID AFTERNOON WITH RIC BEING THE LAST AREA. CLOSER TO THE COAST MANY OF THE CIGS ARE IFR. BELIEVE ENOUGH MIXING WILL OCCUR TO PUSH THE CLOUDS UP TO MVFR LEVELS AT ALL SITES BY LATE AFTERNOON. LOOKING AT BUFKIT SOUNDINGS FROM THE RAP AND NAM ALL SHOW CIGS LOWERING AGAIN AFTER SUNSET. THIS WILL BRING IFR CIGS BACK TO ALL AIRPORTS EXCEPT RIC WHICH WILL MAINLY BE MVFR BUT COULD AT TIMES LOWER TO IFR ESPECIALLY LATE TONIGHT AND EARLY ON WEDNESDAY. MUCH OF THE STATISTICAL GUIDANCE IS GIVING LOWER VSBY TONIGHT HOWEVER LOOKING AT THE BUFKIT SOUNDINGS AND SREF ALL INDICATE KEEPING VSBY MVFR THROUGHOUT THE AREA. FINALLY DURING WEDNESDAY THE COASTAL LOW WILL WEAKEN AND BEGIN TO MOVE AWAY ALLOW WINDS TO SLOWLY SHIFT TO FROM THE LAND. THIS WILL GENERATE SOME MIXING IN THE BOUNDARY LAYER WHICH SHOULD RAISE CIGS TO VFR INLAND AND MVFR ALONG THE COAST. COULD FINALLY HAVE MAINLY VFR CONDITIONS FOR THURSDAY BEFORE THE NEXT FRONT APPROACHES THURSDAY NIGHT WITH ANOTHER CHANCE FOR SHOWERS AND MVFR CONDITIONS. && .MARINE... NE FLOW CONTINUES THIS AFTERNOON BTWN HIGH PRESSURE OVER THE NE STATES AND LOW PRESSURE OFF THE SOUTHEAST COAST. HIGH PRESSURE HAS EXTENDED INTO CNTRL VA...ALLOWING THE GRADIENT TO FINALLY RELAX OVER THE UPPER AND CNTRL BAY (NE WINDS GENERALLY LESS THAN 25 KT). WAVES IN THE UPPER BAY HAVE ALSO SUBSIDED AOB 2 FT. SCA CONDITIONS CONTINUE IN THE LOWER BAY WITH NE WINDS 15 TO 20 WITH GUSTS UP TO 25 KT AND WAVES 3 TO 5 FT (HIGHEST NEAR THE MOUTH OF THE BAY). SEAS REMAIN 5-9 FT...HIGHEST IN THE SOUTH. WILL MAINTAIN CURRENT HEADLINES THIS AFTERNOON...ALLOWING THE LOWER BAY ZONE (NEW POINT COMFORT TO LITTLE CREEK) AND THE CURRITUCK SOUND TO EXPIRE AT 4PM EDT. HIGH PRESSURE WILL MOVE OFF THE NE COAST TONIGHT-WED MORNING AS A WAVE OF LOW PRESSURE LIFTS JUST OFFSHORE. THIS WILL ALLOW THE GRADIENT TO RELAX AND WINDS TO SUBSIDE AOB 15 KT OVER THE WATERS. HEADLINES WILL CONTINUE FOR THE COASTAL WATERS (THRU EARLY WED MORNING) AND THE MOUTH OF THE BAY (THRU 7PM THIS EVENING) FOR SEAS/WAVES. HIGH PRESSURE RIDGE WILL PUSH OFFSHORE TOMORROW...WITH N-NE WINDS VEERING TO THE S-SW LATE WED-WED NIGHT. A COLD FRONT WILL APPROACH FROM THE WEST ON THURS...BEFORE CROSSING THE WATERS LATE THURS NIGHT-FRI MORNING. GRADIENT WILL TIGHTEN ALOFT IN ADVANCE OF THE FRONT...BUT STRONGEST WINDS NOT EXPECTED TO MIX DOWN TO THE WATER. DO NOT ANTICIPATE SCA CONDITIONS PRE-FRONTAL THURS NIGHT...BUT MAY REACH SCA CONDS POST FRONTAL EARLY FRI MORNING. HIGH PRESSURE WILL RETURN OVER THE WATERS FRI AFTERNOON THROUGH THE WEEKEND. && .TIDES/COASTAL FLOODING... ALL COASTAL FLOOD STATEMENTS HAVE BEEN DISCONTINUED AS WATER LEVELS AT HIGH TIDE WILL FALL BELOW MINOR THRESHOLDS. HOWEVER...WATER LEVELS WILL REMAIN ELEVATED OVER THE NEXT SEVERAL HIGH TIDE CYCLES WITH DEPARTURES AVERAGING AROUND 0.5 TO 1.0FT ABOVE NORMAL. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR ANZ634. SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ650-652- 654-656. SMALL CRAFT ADVISORY UNTIL 10 AM EDT WEDNESDAY FOR ANZ658. && $$ SYNOPSIS...LKB NEAR TERM...AJZ/LKB SHORT TERM...LKB LONG TERM...MPR AVIATION...JAB MARINE...SAM TIDES/COASTAL FLOODING...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
204 AM EDT MON OCT 14 2013 .SYNOPSIS... STRONG HIGH PRESSURE WILL SLOWLY PUSH OFF THE NEW ENGLAND COAST THROUGH TUESDAY...AS A TROUGH OF LOW PRESSURE REMAINS ANCHORED OFF THE SOUTHEAST COAST. AS A RESULT...NORTHEAST WINDS WILL CONTINUE TO BRING MAINLY CLOUDY AND DAMP CONDITIONS INTO MONDAY MORNING. A SLOW DRYING TREND IS EXPECTED MONDAY AFTERNOON THROUGH TUESDAY...AS A PORTION OF THE HIGH RIDGES SOUTH INTO THE NORTHERN MID ATLANTIC REGION. THE NEXT COLD FRONT WILL APPROACH FROM THE WEST LATE WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE LATEST SURFACE ANALYSIS SHOWS A 1015MB LOW PRESSURE CENTER OFF THE NC/SC COAST WITH A STEADY PRESSURE TENDENCY. MEANWHILE...A ~1030MB SFC HIGH PRESSURE ANCHORED ALONG THE COAST OF SOUTHERN COAST OF MAINE IS SLOWLY BUILDING SSW INTO THE MID ATLANTIC REVEALED BY +2MB/3HR PRESSURE RISES ACROSS THE REGION. ALOFT...A MID-LEVEL LOW CONTINUES TO LINGER OFF THE COAST ABOVE THE SURFACE REFLECTION OF THE LOW. THE PRIMARY MOIST FRONTAL BAND (DOWNSTREAM OF THE LOW) IS WELL OFF THE COAST OVER THE SUBTROPICAL WESTERN ATLANTIC. HOWEVER...A MOIST AIRSTREAM CONTINUES TO FLOW WESTWARD TOWARD THE LOCAL AREA...WITH IR SATELLITE ENHANCEMENT SUGGESTING SOME LIFT WITHIN THIS AIRSTREAM. THE LATEST RUC BRINGS THIS LIFT INTO NE NC/FAR SE VA LATE TONIGHT INTO EARLY MONDAY...SO A PERIOD OF LIKELY AND CATEGORICAL RAIN HAS BEEN INTRODUCED. OTHERWISE...AREAS OF LIGHT RAIN AND DRIZZLE SHOULD PERSIST OVERNIGHT MAINLY ACROSS SOUTHERN AND WESTERN PORTIONS. WITH NE FLOW REMAINING BREEZY...LOWS WILL AVG 60-65 OVER SE VA/NE NC MID- UPPER 50S NW. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... MON WILL GENLY BEGIN CLOUDY AND DAMP ONCE AGAIN...BUT SLOW DRYING FROM THE NNE WILL BEGIN THROUGH THE DAY. MDL TIME SECTIONS (WHICH GENERALLY HOLD ONTO MSTR UP TO 3-4K FT) WILL HANG ONTO CLDY/DAMP CONDS WELL THROUGH THE DAY MON ACRS SRN VA/NE NC...WHILE SKIES BECOME PARTLY SUNNY ACRS THE NORTH. HIGHS GENLY CLOSE TO 70 F THROUGHOUT. WK REFLECTION OF LO PRES LINGERS INVOF CSTL NC...AND SFC HI PRES NNE OF THE RGN WKNS MON NGT THROUGH TUE. THEREFORE...CONFIDENCE IN PRONOUNCED CLRG...ESP ACRS SRN VA/NE NC...RMNG QUITE LOW. THERE IS NO MECHANISM TO SCOUR OUT THE LO LVL MSTR...AND CONCERNED THAT WHILE THERE WILL LIKELY BE SOME PROGRESS (OR TREND) TOWARD CLRG ERY IN THE WK...LO CLDS WILL BE DIFFICULT TO DISLODGE (OR EVEN IF THERE IS CLRG ON MON IN SOME PLACES - CLDS RETURN MON NGT AND/OR TUE). RA CHCS XPCD TO BE LWR FOR TUE...HWVR...WOULD NOT RULE OUT AT LEAST PTCHY DZ CONTG ACRS THE SE. INCREASING CLOUDINESS FROM THE W TUE NIGHT/WED AS THE SFC RIDGE WEAKENS. WILL SEE PARTLY TO MOSTLY CLOUDY SKIES WED W/ HIGHS 70-75. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... WSW FLOW ALOFT BEGINS TO INCREASE AHEAD OF THE NEXT SYSTEM PUSHING FROM THE UPPER MIDWEST TO THE GREAT LAKES ON WED CAUSING THE SFC RIDGING ASSOCIATED WITH HIGH PRESSURE OFF THE NEW ENGLAND COAST TO WEAKEN. LATEST ECMWF/GFS IN GOOD AGREEMENT THROUGH EARLY FRI SHOWING POTENTIAL FOR MOISTURE AND CLOUDS AS COLD FRONT APPROACHES THE AREA FROM THE WEST. DIFFERENCES BETWEEN THE MODELS BEGIN TO ARISE FRI NIGHT AS GFS SWEEPS THE FRONT THROUGH THE AREA WHILE THE ECMWF STALLS THE FRONT OVER THE AREA. TRENDED TOWARDS THE ECMWF DUE TO TRENDS LATELY IN WHICH COLD FRONTS STRUGGLE TO BE ABLE TO PUSH THEIR WAY COMPLETELY THROUGH THE AREA AND OFF THE COAST. WITH THE FRONT STALLING AROUND THE AREA EXPECT WARMER TEMPS BUT WITH A CLOUDIER/WETTER FORECAST. STRONGEST DYNAMICS STAY WELL TO OUR NW SO WILL ONLY CARRY A 30% POP THU THROUGH FRI MORNING FOR NOW. TEMPS WILL BE CLOSE TO AVG BY DAY WITH HIGHS MAINLY 70-75 AND A BIT ABOVE AVG AT NIGHT WITH LOWS IN THE LOW 50S TO AROUND 60 SE COAST. BY SAT...ECMWF SHOWS ANOTHER FRONT APPROACHING FROM THE WEST AS THE MID LEVEL FLOW REMAINS FROM THE SW AGAIN BRINGING THE POSSIBILITY FOR ANOTHER ROUND OF PRECIP. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... STRONG NE FLOW WILL CONTINUE OVER THE REGION THROUGH TODAY...DUE TO COMBINATION OF STRONG HI PRES BLDNG OVR NEW ENGLAND AND A WEAK AREA OF LO PRES OFF THE MID ATLC AND SE COAST. MAINLY IFR/MVFR CIGS AND OCNL -RA/-DZ WILL PERSIST OVR THE TAF SITES THRU THIS MORNG. BUFKIT SOUNDINGS INDICATE IMPROVEMENT TO MVFR/VFR CONDITIONS THIS AFTN INTO THIS EVENG. BUT...IFR CONDITIONS (FOG OR STRATUS) WILL LIKELY RETURN AGAIN LATE TNGT INTO TUE MORNG...DUE TO ANY CLEARING...CONTINUED WET GROUND...AND LIGHTER NE WINDS. && .MARINE... SOLID SCA CONDITIONS CONTINUE AS TIGHT PRESSURE GRADIENT REMAINS OVER THE WATERS. STRONG 1031 MB SFC HIGH PRESSURE (+1 STD DEV MSLP) WILL CONTINUE TO BUILD OVER THE NE STATES AS THE PERSISTENT SFC LOW OF THE PAST SEVERAL DAYS WILL DRIFT SWD...LOCATING JUST OFF THE SE NC COAST. NE WINDS HAVE INCREASED AS THE STRONGEST LOW LEVEL WINDS TRANSITION SWD OVER THE WATERS. GOOD LOW LEVEL GRADIENT WILL MIX THESE STRONGER WINDS TO THE WATER...WITH GUSTS UP TO 28 KT ALREADY OBSERVED OVER THE CNTRL BAY AND NRN COASTAL ZONES. HIGHER PLATFORMS...INCLUDING THE CBBT...HAVE REACHED 30 KT. STRONG WINDS HAVE BUILT WAVES TO 4-5 FT IN THE BAY AND 6 TO 10 FT OVER THE COASTAL WATERS. HIGH PRESSURE WILL SETTLE OFF THE NE COAST MON AS A WEAK COASTAL TROUGH REMAINS OFF THE COAST. GRADIENT WILL BEGIN TO RELAX OVER THE NRN WATERS...BUT SCA CONDITIONS WILL CONTINUE OVER THE SRN BAY AS NE WINDS REMAIN 15 TO 20 KT AND WAVES 3-4 FT. SEAS WILL SUBSIDE TO NEAR 5-6 FT OVER THE NRN COASTAL ZONES...AS SEAS IN THE SRN ZONES BUILD TO 6-9 FT. HIGH PRESSURE WILL MOVE EWD AWAY FROM THE NE COAST TUES...ALLOWING THE GRADIENT TO RELAX OVER THE WATERS AND NE WINDS TO FINALLY FALL BELOW SCA SPEEDS. HOWEVER...PERSISTENT NE WINDS WILL KEEP SEAS HIGH (5-6 FT) AND SCA HEADLINES THRU LATE TUES. WILL ALSO KEEP SCA HEADLINES IN THE MOUTH OF THE BAY AS 4 FT WAVES ARE FORECAST. HIGH SEAS WILL LIKELY CONTINUE INTO WEDS...BUT CONDITIONS OVER THE BAY/RIVER/SOUND WILL BE FAVORABLE WITH ELY WINDS GENERALLY BELOW 10 KT. A COLD FRONT WILL APPROACH THE WATERS WEDS NIGHT-THURS MORNING. && .TIDES/COASTAL FLOODING... STRONG NE WINDS WILL CONTINUE TO RESULT IN 1 TO 1.5 FOOT (APPROACHING 2 FT ALONG THE COASTAL ERN SHORE DUE TO NEAR GALE FORCE WINDS) TIDAL ANOMALIES THROUGH THE OVERNIGHT. HAVE EXTENDED ALL HEADLINES THROUGH MONDAY MORNINGS HIGH TIDE CYCLES AS MINOR COASTAL FLOODING IS EITHER IMMINENT...OR CONFIDENCE OF REACHING MINOR FLOOD LEVELS IS HIGH. STRONG NE WINDS OVER THE BAY MAY PUSH WATER LEVELS TO NEAR MODERATE THRESHOLDS AT WINDMILL POINT AND THE LOWER NRN NECK MONDAY MORNING. ADVISORY LEVEL FLOODING IS POSSIBLE AGAIN DURING MONDAYS HIGH TIDE CYCLES. SEE CFWAKQ FOR MORE SITE- SPECIFIC TIDAL INFORMATION. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...COASTAL FLOOD ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MDZ024- 025. COASTAL FLOOD ADVISORY UNTIL 3 PM EDT THIS AFTERNOON FOR MDZ021>023. NC...NONE. VA...COASTAL FLOOD ADVISORY UNTIL NOON EDT TODAY FOR VAZ075>078-081- 082-084>086-089>091-093-094-096-097. COASTAL FLOOD ADVISORY UNTIL 8 AM EDT THIS MORNING FOR VAZ095- 098. COASTAL FLOOD ADVISORY UNTIL 10 AM EDT THIS MORNING FOR VAZ099- 100. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ634-650-652- 654-656-658. SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ630-631-636- 637. SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR ANZ635. SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ632. SMALL CRAFT ADVISORY UNTIL NOON EDT TUESDAY FOR ANZ633. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ638. && $$ SYNOPSIS...LKB NEAR TERM...AJZ/LKB SHORT TERM...ALB/LKB LONG TERM...DAP AVIATION...TMG MARINE...SAM TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1026 PM EDT TUE OCT 15 2013 .SYNOPSIS... ISSUED AT 414 PM EDT TUE OCT 15 2013 LOW PRESSURE NEAR THE TWIN CITIES TUESDAY AFTERNOON...WILL MOVE TO EASTERN LAKE SUPERIOR BY WEDNESDAY MORNING. THIS SYSTEM WILL PRODUCE SHOWERS TONIGHT ACROSS ALL OF NORTHERN MICHIGAN. NEAR NORMAL TEMPERATURES WILL LINGER BEHIND THIS SYSTEM FOR THE REST OF THE WORK WEEK. MUCH COOLER WEATHER APPEARS LIKELY BY THE END OF THE WEEKEND. && .UPDATE... ISSUED AT 1016 PM EDT TUE OCT 15 2013 TWEAKED POPS AND REMOVED THUNDER FROM THE FORECAST BASED ON CURRENT RADAR TRENDS. BEGINNING TO SEE SOME CONVECTIVE SHOWER ACTIVITY DEVELOP OVER THE SOUTHERN HALF OF LAKE MICHIGAN...NOT CONFIDENT THAT THIS WILL EVOLVE INTO ANY THUNDER THREAT GIVEN 250J/KG OF ELEVATED CAPE PER LATEST SPC MESOANALYSIS. NUMEROUS SHOWERS...WITH PATCHY DRIZZLE OVER THE HIGHER TERRAIN...WILL CONTINUE ACROSS THE CWA FOR THE REMAINDER OF THE EVENING INTO THE OVERNIGHT WITH THE DEEPEST MOISTURE NOW EXITING NE LOWER PER LATEST WATER VAPOR LOOP. SKIES WILL REMAIN OVERALL CLOUDY...BUT WOULD NOT BE SURPRISED TO SEE SOME CLEARING ASSOCIATED WITH APPROACHING DRY SLOT CLIP THE SW PORTION OF THE FORECAST AREA FOR A BRIEF TIME...BEFORE WRAP AROUND CLOUDS AND MOISTURE FILTER BACK INTO THE PICTURE LATE TONIGHT. TEMPERATURES WILL REMAIN STEADY OR SLOWLY RISE LATE THIS EVENING AS OCCLUDED FRONT APPROACHES...BUT WILL DROP BACK INTO THE 40S LATE TONIGHT AS COLD AIR ADVECTION ENSUES. UPDATE ISSUED AT 743 PM EDT TUE OCT 15 2013 LITTLE CHANGES TO THE FORECAST AT THIS TIME. SWATH OF RAINFALL ASSOCIATED WITH WAA/ISENTROPIC ASCENT IS RAPIDLY MOVING THROUGH THE CWA ATTM...AND WILL LIKELY BE OUT OF THE AREA BY AROUND 03Z. MAIN QUESTION IS WHETHER OR NOT WE CAN REDEVELOP SOME CONVECTION WITH APPROACHING DRY SLOT AND COLD FRONT. THINGS NOT LOOKING GOOD AT ALL REGARDING THAT SCENARIO...WITH NO SIGNS OF CONVECTION UPSTREAM. WHILE LATEST RUC CONTINUES TO SHOW SOME ELEVATED INSTABILITY SKIRTING MAINLY THE NORTHERN HALF OF THE CWA...SHORT TERM RUC SOUNDINGS ALSO DEPICT SOME MID LEVEL CAPPING WITH THE ARRIVAL OF SAID DRY SLOT/STEEPER MID LEVEL LAPSE RATES. WILL MAINTAIN THUNDER MENTION FOR NOW...BUT WILL LIKELY HAVE TO REMOVE IT FROM THE FORECAST BY THE NEXT UPDATE IF THINGS DON`T GET GOING SOON. OTHERWISE LINGERING MOIST BOUNDARY LAYER WILL BRING PERIODS OF LOW CLOUDS AND VERY LIGHT RAIN SHOWERS OR DRIZZLE FOR THE REMAINDER OF THE EVENING INTO THE EARLY OVERNIGHT. TEMPERATURES WILL REMAIN STEADY IN THE 50S...WITH WINDS VEERING TO THE SOUTHWEST LATER TONIGHT WITH THE FRONTAL PASSAGE AND SUBTLE INCREASE IN THE PRESSURE GRADIENT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 414 PM EDT TUE OCT 15 2013 A BIT OF A CHALLENGING FORECAST THE NEXT 24 HOURS...BUT IN THE GRAND SCHEME OF THINGS...QUITE TYPICAL FOR OCTOBER...WITH THE MAIN FORECAST ISSUES BEING RAIN AND POSSIBLE CONVECTION THROUGH THE EVENING...AND LAKE EFFECT/WATERSPOUT ISSUES INTO WEDNESDAY. EARLY AFTERNOON ANALYSIS PLACES A RATHER POTENT CLOSED LOW MEANDERING THROUGH SOUTHERN MINNESOTA...TAKING ON THE CLASSIC OCCLUDING CYCLONE LOOK THE PAST 12 HOURS. A DISTINCT DRY SLOT IS JUST NOW PUNCHING THROUGH THE WESTERN LAKES...WITH A NARROW RIBBON OF DEEP MOISTURE (PWAT VALUES IN EXCESS OF 1.1 INCHES) NOTED FLOWING FROM THE BAJA PENINSULA RIGHT UP INTO OUR NECK OF THE WOODS. REGIONAL RADAR MOSAIC SHOWS A NICE BATCH OF RAIN FINALLY WORKING EAST FROM WISCONSIN INTO LAKE MICHIGAN AND BUMPING UP AGAINST THE NORTHWEST CWA...WITH A BIT MORE NARROWED RAIN SHIELD EXTENDING INTO THE LOWER LAKES AND TO A GREATER EXTENT THE WESTERN TENNESSEE/MID MISSISSIPPI VALLEY. THAT NORTHERN RAIN SHIELD IS ASSOCIATED WITH A DECENT AXIS OF BOTH LOW/MID LEVEL WARM ADVECTION ASCENT AND PRONOUNCED 850-500MB QG UPWARD FORCING...WHILE THE SOUTHERN STUFF IS MORE TIED TO AN UPPER JET STREAK/JET FORCING RIDING THROUGH THE SOUTHERN PLAINS. THE BIG QUESTION FOR LATE AFTERNOON/EVENING IS JUST WHAT TYPE OF RAIN COVERAGE/AMOUNTS WE WILL END UP WITH. NO DOUBT THE CURRENT RAIN SHIELD WILL CONTINUE ITS SLOW NORTH/NORTHEAST JAUNT...SUGGESTING GOING CATEGORICAL POPS ARE JUST FINE FOR MUCH OF NORTHWEST LOWER AND EASTERN UPPER. THE BIG QUESTION IS WHAT HAPPENS ACROSS NORTHEAST LOWER AS THAT BAND MAY FIZZLE WITH TIME AS IT OUTRUNS THE BETTER ASCENT WHILE A NOTABLE BREAK HAS ALREADY DEVELOPED ACROSS THE SOUTHERN LAKES. A BIT CONCERNED THIS BREAK MAY SLIDE NORTHEASTWARD ON THE DOWNWARD SIDE OF THE UPPER JET AND PROVIDE LESSER AMOUNTS WITH EASTWARD EXTENT. HOWEVER...WITH THAT SAID...STILL BELIEVE JUST ABOUT ALL FOLKS WILL END UP WITH SOME MEASURABLE RAINS AND CATEGORICAL POPS WILL CONTINUE. AS FOR CONVECTIVE CHANCES...CONFIDENCE IS WANING GIVEN THE LACK OF ANY UPSTREAM ACTIVITY JUST YET. STILL LOOKING AT A QUITE STEEP PLUME OF 700-500MB LAPSE RATES (PUSHING 8C/KM) WORKING ACROSS IOWA/ SOUTHERN WISCONSIN...WHERE THERE IS SOME CLEARING ONGOING AND HINTS OF CU DEVELOPMENT. WILL HAVE TO WATCH AND SEE IF THINGS CAN GET GOING IN ANOTHER FEW HOURS...BUT WILL OVERALL LOWER THE THUNDER MENTION TO SLIGHT CHANCE AS THE ELEVATED INSTABILITY (UP TO 500J/KG) AND STEEP LAPSE RATES WILL BE THERE ALONG THE DRY SLOT...BUT CONFIDENCE IS LOW WITH THE LACK OF CURRENT ACTIVITY. OTHERWISE...DRY SLOT WILL END THE MORE WIDESPREAD RAINFALL TOWARD OR JUST AFTER MIDNIGHT...WITH MORE SHOWERY CONDITIONS POSSIBLE THE REST OF THE NIGHT...PERHAPS ENHANCED BY THE LAKES TOWARD MORNING AS H8 TEMPS COOL BACK TOWARD 3C. OUR BETTER CHANCE FOR LAKE ENHANCED PRECIP WILL COME WEDNESDAY AS THE UPPER LOW TO THE WEST OPENS UP AND SLOWLY SLIDES OVERHEAD. NICE SLUG OF DEEPER MOISTURE AND MORE THAN SUFFICIENT LAKE INSTABILITY SHOULD RESULT IN QUITE A FEW LAKE EFFECT/ENHANCED SHOWERS...WITH SOME DIURNAL COMPONENT ALSO POSSIBLE BENEATH THE UPPER COLD POOL. SHOULD SEE A WATERSPOUT THREAT FOR A TIME...ESPECIALLY WEDNESDAY MORNING AS THE DEEPER VORTICITY AXIS PULLS OVERHEAD...WHILE A SECONDARY COLD FRONT/FORCING BOUNDARY CROSSES LAKE MICHIGAN. LATEST SZILAGYI NOMOGRAM PLOTS HIGHLIGHT THIS IDEA WELL AND PROBABLY WORTH A MENTION. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 414 PM EDT TUE OCT 15 2013 OVERVIEW: FOUR-WAVE LONG WAVE PATTERN IN PLACE ACROSS THE NRN HEMISPHERE WITH LONG WAVE TROUGHINESS DEEPENING ACROSS CENTRAL NOAM IN RESPONSE TO LONG-WAVE RIDGING BUILDING FROM THE GULF OF ALASKA DOWN ALONG THE PACIFIC COAST. THIS AMPLIFIED RIDGE WEST/TROUGH EAST PATTERN STILL ON TRACK TO GET "LOCKED IN" THROUGH AT LEAST THE NEXT SEVEN TO TEN DAYS (AND BEYOND) LEADING TO THE MUCH ADVERTISED COOL DOWN AND SLIDE INTO TRUE FALL FOR THE MIDWEST/GREAT LAKES...AND A SIZABLE PART OF EASTERN NOAM FOR THAT MATTER. IN FACT...A SUBSTANTIAL COOL DOWN MAY BE IN THE WORKS AS A COUPLE POCKETS OF FAIRLY COLD AIR GET DISLODGED FROM NRN CANADA AND SLIDE DOWN INTO THE MIDWEST/GREAT LAKES REGION GOING THROUGH THE WEEKEND AND NEXT WEEK (POSSIBLY LINKED TO ONGOING TYPHOON ACTIVITY IN THE WESTERN PACIFIC). REGARDLESS...AT LEAST A POSSIBILITY THAT WE SEE A LITTLE SNOW OR AT LEAST SOME SNOW OR RAIN/SNOW MIX IN THIS CWA DURING THE COURSE OF THE EXTENDED FORECAST. IN THE SHORTER TERM...NO SNOW THROUGH THE BALANCE OF THE WORK WEEK AS WE ARE JUST NOT COLD ENOUGH...YET. BUT WE DO HAVE A COUPLE SRN STREAM WAVES TO WORRY ABOUT AS THEY ROTATE AROUND THE AFOREMENTIONED DEEPENING LONG WAVE TROUGH. FIRST OF THESE WAVES IS MOVING THROUGH THE REGION TONIGHT AND WEDNESDAY (HANDLED IN THE SHORT TERM PART OF THE FORECAST). NEXT PIECE OF SRN STREAM ENERGY/SHORT WAVE DIPPING INTO THE FOUR CORNERS REGION TODAY AND FORECAST TO SWING UP THROUGH THE MIDWEST WEDNESDAY NIGHT...THEN UP THROUGH LOWER MICHIGAN DURING THE DAY THURSDAY. NOT A PARTICULARLY MOIST SYSTEM ORIGINATING FROM THE FOUR CORNERS AND NO SUPPORTING TAP OF GULF MOISTURE. BUT IT IS A DECENT WAVE LEADING TO A NICE SHOT OF QG-UPWARD FORCING MOVING THROUGH LOWER MICHIGAN THURSDAY AFTERNOON. BEST CHANCE FOR RAINFALL LOOKING TO OCCUR ACROSS CENTRAL AND SRN LOWER MICHIGAN ALONG AND SOUTH OF THE SHORT WAVE TRACK. BUT NOT COMFORTABLE HAVING A COMPLETELY DRY FORECAST FOR THIS CWA ON THURSDAY AND HAVE INTRODUCED SOME CHANCY POPS FOR THE S/SE HALF OF THE CWA PARTICULARLY DOWN TOWARD SAGINAW BAY. THURSDAY NIGHT THROUGH FRIDAY...BEHIND THURSDAYS SYSTEM...A BRIEF LULL ANTICIPATED THURSDAY NIGHT COURTESY OF A WEDGE OF DRIER AIR/SUBTLE SHORT WAVE RIDGING AND DOWNWARD QG FORCING. THAT SAID...CERTAINLY ENOUGH LOW LEVEL COLD AIR TO WORRY ABOUT LAKE EFFECT RAIN SHOWER PROSPECTS GIVEN H8 TEMPS JUST A FEW DEGREES ABOVE 0C. BUT IN TRYING TO FIND A LEAST ONE DRY FORECAST PERIOD OVER THE NEXT SEVERAL...THURSDAY NIGHT PROBABLY HAS THE BEST SHOT AND WILL LEAVE IT DRY FOR NOW. HEADING THROUGH FRIDAY...UPPER LEVEL TROUGHINESS BEGINS TO DESCEND INTO THE UPPER MIDWEST/WESTERN GREAT LAKES BEGINNING WITH A SUBTLE COLD FRONT PASSAGE DURING THE DAY FRIDAY. POSSIBILITIES FOR ANOTHER BATCH OF RAINFALL TO DEVELOP ALONG THE FRONT...ADVANCING THROUGH THE REGION THROUGH THE DAY FRIDAY FOLLOWED BY CONTINUING LAKE INDUCED RAIN SHOWER POSSIBILITIES FRIDAY NIGHT. OVERALL...THE START OF A RATHER UNSETTLED AND COOLER PERIOD FOR THE GREAT LAKES. SATURDAY THROUGH TUESDAY (EXTENDED PERIODS)... AS MENTIONED ABOVE...SUBSTANTIAL TROUGHINESS/COLDER AIR CARVES OUT ACROSS CENTRAL AND EASTERN CANADA AND DOWN INTO THE UPPER MIDWEST AND GREAT LAKES DURING THE COURSE OF THE WEEKEND. POTENTIAL FOR ANOTHER REINFORCING PUSH OF YET COLDER AIR FOR THE FIRST HALF OF NEXT WORK WEEK. BUT THE DEVIL IS IN THE DETAILS AND THE GFS/EURO SOLUTIONS HAVE HAD SUBSTANTIAL DIFFERENCES ON JUST HOW THE PATTERN EVOLVES AND HOW COLD IT GETS. EURO HAS BEEN RELUCTANT TO DRAG THE MORE SUBSTANTIAL COLD AIR (COLD ENOUGH FOR THE MENTION OF SNOW) INTO THE GREAT LAKES UNTIL NEXT WEEK...WHILE GFS DEVELOPS A STRONGER LOW PRESSURE SYSTEM FOR SATURDAY INTO SUNDAY WHICH DRAGS -4C TO -6C H8 AIR INTO THE REGION AS EARLY AS SUNDAY (USUALLY NEED AT LEAST -5C H8 TEMPS THIS TIME OF YEAR TO SEE SNOW). THE OVERRIDING IDEA IN THE FORECAST WILL BE A STRETCH OF BELOW NORMAL TEMPERATURES AND UNSETTLED (WET) WEATHER THROUGH THE EXTENDED. BUT IT IS POSSIBLE WE SEE A LITTLE BIT OF SNOW OR RAIN/SNOW MIX FOR INLAND AREAS EITHER LATE SATURDAY INTO SUNDAY (PER GFS COLDER IDEA) OR THE EARLY TO MID PART OF THE NEXT WEEK AS SOME THE COLDEST AIR FINALLY GETS PULLED INTO THE REGION. HAVE NOT ADDED THE MENTION OF SNOW TO THE FORECAST JUST YET HOWEVER...GIVEN THE UNCERTAINTY AND GIVEN THAT...AT LEAST RIGHT NOW...WHATEVER SNOW WE MIGHT SEE LOOKS TRANSIENT AND FAIRLY LOW IMPACT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 743 PM EDT TUE OCT 15 2013 SWATH OF RAIN WILL CONTINUE TO ROLL THROUGH NORTHERN MICHIGAN THIS EVENING...EXITING NORTHEAST LOWER BY AROUND 03Z. BEHIND THIS AREA OF RAIN...LINGERING LOW LEVEL MOISTURE WILL BRING LOWERING CIGS TO HIGHER END IFR FOR ALL TAF SITES IN THE 02 TO 09Z TIMEFRAME...WITH SOME MFVR VSBYS AND PERIODS OF DRIZZLE. LOW LEVEL WIND SHEAR WILL ALSO BE A CONCERN THIS EVENING...BUT WILL DIMINISH BY AROUND MIDNIGHT AS WINDS THROUGHOUT THE BOUNDARY LAYER BECOME MORE UNIFORM AND SOUTHWESTERLY. ANY THUNDER THREAT LOOKS GREATLY DIMINISHED ATTM. SLIGHTLY DRIER AIR WILL BEGIN TO FILTER INTO NORTHERN MICHIGAN VERY LATE TONIGHT ON THE BACK SIDE OF THE DEPARTING LOW PRESSURE SYSTEM. HOWEVER...LINGERING SHOWERS AND MVFR CIGS WILL HOLD THROUGH THE DAY WEDNESDAY WITH GUSTY SOUTHWESTERLY WINDS...SHIFTING MORE NORTHWESTERLY LATER IN THE DAY. && .MARINE... ISSUED AT 414 PM EDT TUE OCT 15 2013 SOME GUSTY CONDITIONS ARE EXPECTED ON THE LAKES...INITIALLY OUT OF THE SOUTHEAST AHEAD OF AN APPROACHING COLD FRONT...THEN SWITCHING SOUTHWEST LATER TONIGHT...AND EVENTUALLY NORTHWEST ON WEDNESDAY AS ANOTHER COLD FRONT PASSES. CONDITIONS WILL LIKELY APPROACH SMALL CRAFT ADVISORY LEVELS AT VARIOUS INTERVALS...AND HAVE SIMPLY CONTINUED THE GOING ADVISORY THROUGH THE NIGHT FOR MOST OF THE WATERS...THOUGH ARGUABLY NOT ALL SPOTS WILL SEE CRITERIA ALL OF THE TIME. THIS SYSTEM WILL DEPART INTO THURSDAY...LEAVING A PERIOD OF MUCH LIGHTER WINDS...BEFORE SEVERAL MORE WEAKER LOW PRESSURE AREAS TRACK NEARBY RIGHT ON INTO THE WEEKEND. AT THIS POINT...THERE IS NO BIG INDICATION THAN ANY SIGNIFICANT PERIODS OF WIND OR WAVES WILL OCCUR TROUGH AT LEAST SUNDAY. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LHZ345-347>349. SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LHZ346. LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LMZ323-342- 344>346. SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LMZ341. LS...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR LSZ321-322. && $$ UPDATE...NS SYNOPSIS...JZ SHORT TERM...LAWRENCE LONG TERM...ADAM AVIATION...NS MARINE...LAWRENCE
AREA FORECAST DISCUSSION
NWS GAYLORD MI
802 PM EDT TUE OCT 15 2013 .SYNOPSIS... ISSUED AT 414 PM EDT TUE OCT 15 2013 LOW PRESSURE NEAR THE TWIN CITIES TUESDAY AFTERNOON...WILL MOVE TO EASTERN LAKE SUPERIOR BY WEDNESDAY MORNING. THIS SYSTEM WILL PRODUCE SHOWERS TONIGHT ACROSS ALL OF NORTHERN MICHIGAN. NEAR NORMAL TEMPERATURES WILL LINGER BEHIND THIS SYSTEM FOR THE REST OF THE WORK WEEK. MUCH COOLER WEATHER APPEARS LIKELY BY THE END OF THE WEEKEND. && .UPDATE... ISSUED AT 743 PM EDT TUE OCT 15 2013 LITTLE CHANGES TO THE FORECAST AT THIS TIME. SWATH OF RAINFALL ASSOCIATED WITH WAA/ISENTROPIC ASCENT IS RAPIDLY MOVING THROUGH THE CWA ATTM...AND WILL LIKELY BE OUT OF THE AREA BY AROUND 03Z. MAIN QUESTION IS WHETHER OR NOT WE CAN REDEVELOP SOME CONVECTION WITH APPROACHING DRY SLOT AND COLD FRONT. THINGS NOT LOOKING GOOD AT ALL REGARDING THAT SCENARIO...WITH NO SIGNS OF CONVECTION UPSTREAM. WHILE LATEST RUC CONTINUES TO SHOW SOME ELEVATED INSTABILITY SKIRTING MAINLY THE NORTHERN HALF OF THE CWA...SHORT TERM RUC SOUNDINGS ALSO DEPICT SOME MID LEVEL CAPPING WITH THE ARRIVAL OF SAID DRY SLOT/STEEPER MID LEVEL LAPSE RATES. WILL MAINTAIN THUNDER MENTION FOR NOW...BUT WILL LIKELY HAVE TO REMOVE IT FROM THE FORECAST BY THE NEXT UPDATE IF THINGS DON`T GET GOING SOON. OTHERWISE LINGERING MOIST BOUNDARY LAYER WILL BRING PERIODS OF LOW CLOUDS AND VERY LIGHT RAIN SHOWERS OR DRIZZLE FOR THE REMAINDER OF THE EVENING INTO THE EARLY OVERNIGHT. TEMPERATURES WILL REMAIN STEADY IN THE 50S...WITH WINDS VEERING TO THE SOUTHWEST LATER TONIGHT WITH THE FRONTAL PASSAGE AND SUBTLE INCREASE IN THE PRESSURE GRADIENT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 414 PM EDT TUE OCT 15 2013 A BIT OF A CHALLENGING FORECAST THE NEXT 24 HOURS...BUT IN THE GRAND SCHEME OF THINGS...QUITE TYPICAL FOR OCTOBER...WITH THE MAIN FORECAST ISSUES BEING RAIN AND POSSIBLE CONVECTION THROUGH THE EVENING...AND LAKE EFFECT/WATERSPOUT ISSUES INTO WEDNESDAY. EARLY AFTERNOON ANALYSIS PLACES A RATHER POTENT CLOSED LOW MEANDERING THROUGH SOUTHERN MINNESOTA...TAKING ON THE CLASSIC OCCLUDING CYCLONE LOOK THE PAST 12 HOURS. A DISTINCT DRY SLOT IS JUST NOW PUNCHING THROUGH THE WESTERN LAKES...WITH A NARROW RIBBON OF DEEP MOISTURE (PWAT VALUES IN EXCESS OF 1.1 INCHES) NOTED FLOWING FROM THE BAJA PENINSULA RIGHT UP INTO OUR NECK OF THE WOODS. REGIONAL RADAR MOSAIC SHOWS A NICE BATCH OF RAIN FINALLY WORKING EAST FROM WISCONSIN INTO LAKE MICHIGAN AND BUMPING UP AGAINST THE NORTHWEST CWA...WITH A BIT MORE NARROWED RAIN SHIELD EXTENDING INTO THE LOWER LAKES AND TO A GREATER EXTENT THE WESTERN TENNESSEE/MID MISSISSIPPI VALLEY. THAT NORTHERN RAIN SHIELD IS ASSOCIATED WITH A DECENT AXIS OF BOTH LOW/MID LEVEL WARM ADVECTION ASCENT AND PRONOUNCED 850-500MB QG UPWARD FORCING...WHILE THE SOUTHERN STUFF IS MORE TIED TO AN UPPER JET STREAK/JET FORCING RIDING THROUGH THE SOUTHERN PLAINS. THE BIG QUESTION FOR LATE AFTERNOON/EVENING IS JUST WHAT TYPE OF RAIN COVERAGE/AMOUNTS WE WILL END UP WITH. NO DOUBT THE CURRENT RAIN SHIELD WILL CONTINUE ITS SLOW NORTH/NORTHEAST JAUNT...SUGGESTING GOING CATEGORICAL POPS ARE JUST FINE FOR MUCH OF NORTHWEST LOWER AND EASTERN UPPER. THE BIG QUESTION IS WHAT HAPPENS ACROSS NORTHEAST LOWER AS THAT BAND MAY FIZZLE WITH TIME AS IT OUTRUNS THE BETTER ASCENT WHILE A NOTABLE BREAK HAS ALREADY DEVELOPED ACROSS THE SOUTHERN LAKES. A BIT CONCERNED THIS BREAK MAY SLIDE NORTHEASTWARD ON THE DOWNWARD SIDE OF THE UPPER JET AND PROVIDE LESSER AMOUNTS WITH EASTWARD EXTENT. HOWEVER...WITH THAT SAID...STILL BELIEVE JUST ABOUT ALL FOLKS WILL END UP WITH SOME MEASURABLE RAINS AND CATEGORICAL POPS WILL CONTINUE. AS FOR CONVECTIVE CHANCES...CONFIDENCE IS WANING GIVEN THE LACK OF ANY UPSTREAM ACTIVITY JUST YET. STILL LOOKING AT A QUITE STEEP PLUME OF 700-500MB LAPSE RATES (PUSHING 8C/KM) WORKING ACROSS IOWA/ SOUTHERN WISCONSIN...WHERE THERE IS SOME CLEARING ONGOING AND HINTS OF CU DEVELOPMENT. WILL HAVE TO WATCH AND SEE IF THINGS CAN GET GOING IN ANOTHER FEW HOURS...BUT WILL OVERALL LOWER THE THUNDER MENTION TO SLIGHT CHANCE AS THE ELEVATED INSTABILITY (UP TO 500J/KG) AND STEEP LAPSE RATES WILL BE THERE ALONG THE DRY SLOT...BUT CONFIDENCE IS LOW WITH THE LACK OF CURRENT ACTIVITY. OTHERWISE...DRY SLOT WILL END THE MORE WIDESPREAD RAINFALL TOWARD OR JUST AFTER MIDNIGHT...WITH MORE SHOWERY CONDITIONS POSSIBLE THE REST OF THE NIGHT...PERHAPS ENHANCED BY THE LAKES TOWARD MORNING AS H8 TEMPS COOL BACK TOWARD 3C. OUR BETTER CHANCE FOR LAKE ENHANCED PRECIP WILL COME WEDNESDAY AS THE UPPER LOW TO THE WEST OPENS UP AND SLOWLY SLIDES OVERHEAD. NICE SLUG OF DEEPER MOISTURE AND MORE THAN SUFFICIENT LAKE INSTABILITY SHOULD RESULT IN QUITE A FEW LAKE EFFECT/ENHANCED SHOWERS...WITH SOME DIURNAL COMPONENT ALSO POSSIBLE BENEATH THE UPPER COLD POOL. SHOULD SEE A WATERSPOUT THREAT FOR A TIME...ESPECIALLY WEDNESDAY MORNING AS THE DEEPER VORTICITY AXIS PULLS OVERHEAD...WHILE A SECONDARY COLD FRONT/FORCING BOUNDARY CROSSES LAKE MICHIGAN. LATEST SZILAGYI NOMOGRAM PLOTS HIGHLIGHT THIS IDEA WELL AND PROBABLY WORTH A MENTION. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 414 PM EDT TUE OCT 15 2013 OVERVIEW: FOUR-WAVE LONG WAVE PATTERN IN PLACE ACROSS THE NRN HEMISPHERE WITH LONG WAVE TROUGHINESS DEEPENING ACROSS CENTRAL NOAM IN RESPONSE TO LONG-WAVE RIDGING BUILDING FROM THE GULF OF ALASKA DOWN ALONG THE PACIFIC COAST. THIS AMPLIFIED RIDGE WEST/TROUGH EAST PATTERN STILL ON TRACK TO GET "LOCKED IN" THROUGH AT LEAST THE NEXT SEVEN TO TEN DAYS (AND BEYOND) LEADING TO THE MUCH ADVERTISED COOL DOWN AND SLIDE INTO TRUE FALL FOR THE MIDWEST/GREAT LAKES...AND A SIZABLE PART OF EASTERN NOAM FOR THAT MATTER. IN FACT...A SUBSTANTIAL COOL DOWN MAY BE IN THE WORKS AS A COUPLE POCKETS OF FAIRLY COLD AIR GET DISLODGED FROM NRN CANADA AND SLIDE DOWN INTO THE MIDWEST/GREAT LAKES REGION GOING THROUGH THE WEEKEND AND NEXT WEEK (POSSIBLY LINKED TO ONGOING TYPHOON ACTIVITY IN THE WESTERN PACIFIC). REGARDLESS...AT LEAST A POSSIBILITY THAT WE SEE A LITTLE SNOW OR AT LEAST SOME SNOW OR RAIN/SNOW MIX IN THIS CWA DURING THE COURSE OF THE EXTENDED FORECAST. IN THE SHORTER TERM...NO SNOW THROUGH THE BALANCE OF THE WORK WEEK AS WE ARE JUST NOT COLD ENOUGH...YET. BUT WE DO HAVE A COUPLE SRN STREAM WAVES TO WORRY ABOUT AS THEY ROTATE AROUND THE AFOREMENTIONED DEEPENING LONG WAVE TROUGH. FIRST OF THESE WAVES IS MOVING THROUGH THE REGION TONIGHT AND WEDNESDAY (HANDLED IN THE SHORT TERM PART OF THE FORECAST). NEXT PIECE OF SRN STREAM ENERGY/SHORT WAVE DIPPING INTO THE FOUR CORNERS REGION TODAY AND FORECAST TO SWING UP THROUGH THE MIDWEST WEDNESDAY NIGHT...THEN UP THROUGH LOWER MICHIGAN DURING THE DAY THURSDAY. NOT A PARTICULARLY MOIST SYSTEM ORIGINATING FROM THE FOUR CORNERS AND NO SUPPORTING TAP OF GULF MOISTURE. BUT IT IS A DECENT WAVE LEADING TO A NICE SHOT OF QG-UPWARD FORCING MOVING THROUGH LOWER MICHIGAN THURSDAY AFTERNOON. BEST CHANCE FOR RAINFALL LOOKING TO OCCUR ACROSS CENTRAL AND SRN LOWER MICHIGAN ALONG AND SOUTH OF THE SHORT WAVE TRACK. BUT NOT COMFORTABLE HAVING A COMPLETELY DRY FORECAST FOR THIS CWA ON THURSDAY AND HAVE INTRODUCED SOME CHANCY POPS FOR THE S/SE HALF OF THE CWA PARTICULARLY DOWN TOWARD SAGINAW BAY. THURSDAY NIGHT THROUGH FRIDAY...BEHIND THURSDAYS SYSTEM...A BRIEF LULL ANTICIPATED THURSDAY NIGHT COURTESY OF A WEDGE OF DRIER AIR/SUBTLE SHORT WAVE RIDGING AND DOWNWARD QG FORCING. THAT SAID...CERTAINLY ENOUGH LOW LEVEL COLD AIR TO WORRY ABOUT LAKE EFFECT RAIN SHOWER PROSPECTS GIVEN H8 TEMPS JUST A FEW DEGREES ABOVE 0C. BUT IN TRYING TO FIND A LEAST ONE DRY FORECAST PERIOD OVER THE NEXT SEVERAL...THURSDAY NIGHT PROBABLY HAS THE BEST SHOT AND WILL LEAVE IT DRY FOR NOW. HEADING THROUGH FRIDAY...UPPER LEVEL TROUGHINESS BEGINS TO DESCEND INTO THE UPPER MIDWEST/WESTERN GREAT LAKES BEGINNING WITH A SUBTLE COLD FRONT PASSAGE DURING THE DAY FRIDAY. POSSIBILITIES FOR ANOTHER BATCH OF RAINFALL TO DEVELOP ALONG THE FRONT...ADVANCING THROUGH THE REGION THROUGH THE DAY FRIDAY FOLLOWED BY CONTINUING LAKE INDUCED RAIN SHOWER POSSIBILITIES FRIDAY NIGHT. OVERALL...THE START OF A RATHER UNSETTLED AND COOLER PERIOD FOR THE GREAT LAKES. SATURDAY THROUGH TUESDAY (EXTENDED PERIODS)... AS MENTIONED ABOVE...SUBSTANTIAL TROUGHINESS/COLDER AIR CARVES OUT ACROSS CENTRAL AND EASTERN CANADA AND DOWN INTO THE UPPER MIDWEST AND GREAT LAKES DURING THE COURSE OF THE WEEKEND. POTENTIAL FOR ANOTHER REINFORCING PUSH OF YET COLDER AIR FOR THE FIRST HALF OF NEXT WORK WEEK. BUT THE DEVIL IS IN THE DETAILS AND THE GFS/EURO SOLUTIONS HAVE HAD SUBSTANTIAL DIFFERENCES ON JUST HOW THE PATTERN EVOLVES AND HOW COLD IT GETS. EURO HAS BEEN RELUCTANT TO DRAG THE MORE SUBSTANTIAL COLD AIR (COLD ENOUGH FOR THE MENTION OF SNOW) INTO THE GREAT LAKES UNTIL NEXT WEEK...WHILE GFS DEVELOPS A STRONGER LOW PRESSURE SYSTEM FOR SATURDAY INTO SUNDAY WHICH DRAGS -4C TO -6C H8 AIR INTO THE REGION AS EARLY AS SUNDAY (USUALLY NEED AT LEAST -5C H8 TEMPS THIS TIME OF YEAR TO SEE SNOW). THE OVERRIDING IDEA IN THE FORECAST WILL BE A STRETCH OF BELOW NORMAL TEMPERATURES AND UNSETTLED (WET) WEATHER THROUGH THE EXTENDED. BUT IT IS POSSIBLE WE SEE A LITTLE BIT OF SNOW OR RAIN/SNOW MIX FOR INLAND AREAS EITHER LATE SATURDAY INTO SUNDAY (PER GFS COLDER IDEA) OR THE EARLY TO MID PART OF THE NEXT WEEK AS SOME THE COLDEST AIR FINALLY GETS PULLED INTO THE REGION. HAVE NOT ADDED THE MENTION OF SNOW TO THE FORECAST JUST YET HOWEVER...GIVEN THE UNCERTAINTY AND GIVEN THAT...AT LEAST RIGHT NOW...WHATEVER SNOW WE MIGHT SEE LOOKS TRANSIENT AND FAIRLY LOW IMPACT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 743 PM EDT TUE OCT 15 2013 SWATH OF RAIN WILL CONTINUE TO ROLL THROUGH NORTHERN MICHIGAN THIS EVENING...EXITING NORTHEAST LOWER BY AROUND 03Z. BEHIND THIS AREA OF RAIN...LINGERING LOW LEVEL MOISTURE WILL BRING LOWERING CIGS TO HIGHER END IFR FOR ALL TAF SITES IN THE 02 TO 09Z TIMEFRAME...WITH SOME MFVR VSBYS AND PERIODS OF DRIZZLE. LOW LEVEL WIND SHEAR WILL ALSO BE A CONCERN THIS EVENING...BUT WILL DIMINISH BY AROUND MIDNIGHT AS WINDS THROUGHOUT THE BOUNDARY LAYER BECOME MORE UNIFORM AND SOUTHWESTERLY. ANY THUNDER THREAT LOOKS GREATLY DIMINISHED ATTM. SLIGHTLY DRIER AIR WILL BEGIN TO FILTER INTO NORTHERN MICHIGAN VERY LATE TONIGHT ON THE BACK SIDE OF THE DEPARTING LOW PRESSURE SYSTEM. HOWEVER...LINGERING SHOWERS AND MVFR CIGS WILL HOLD THROUGH THE DAY WEDNESDAY WITH GUSTY SOUTHWESTERLY WINDS...SHIFTING MORE NORTHWESTERLY LATER IN THE DAY. && .MARINE... ISSUED AT 414 PM EDT TUE OCT 15 2013 SOME GUSTY CONDITIONS ARE EXPECTED ON THE LAKES...INITIALLY OUT OF THE SOUTHEAST AHEAD OF AN APPROACHING COLD FRONT...THEN SWITCHING SOUTHWEST LATER TONIGHT...AND EVENTUALLY NORTHWEST ON WEDNESDAY AS ANOTHER COLD FRONT PASSES. CONDITIONS WILL LIKELY APPROACH SMALL CRAFT ADVISORY LEVELS AT VARIOUS INTERVALS...AND HAVE SIMPLY CONTINUED THE GOING ADVISORY THROUGH THE NIGHT FOR MOST OF THE WATERS...THOUGH ARGUABLY NOT ALL SPOTS WILL SEE CRITERIA ALL OF THE TIME. THIS SYSTEM WILL DEPART INTO THURSDAY...LEAVING A PERIOD OF MUCH LIGHTER WINDS...BEFORE SEVERAL MORE WEAKER LOW PRESSURE AREAS TRACK NEARBY RIGHT ON INTO THE WEEKEND. AT THIS POINT...THERE IS NO BIG INDICATION THAN ANY SIGNIFICANT PERIODS OF WIND OR WAVES WILL OCCUR TROUGH AT LEAST SUNDAY. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LHZ345-347>349. SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LHZ346. LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LMZ323-342- 344>346. SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LMZ341. LS...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR LSZ321-322. && $$ UPDATE...NS SYNOPSIS...JZ SHORT TERM...LAWRENCE LONG TERM...ADAM AVIATION...NS MARINE...LAWRENCE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 PM EDT MON OCT 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 527 AM EDT MON OCT 14 2013 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL LOW LIFTING NE ACROSS HUDSON BAY WITH A TROF EXTENDING SW INTO THE ROCKIES WHERE ANOTHER SHORTWAVE WAS LOCATED OVER UT/CO. THIS SHORTWAVE WILL BEGIN TO AFFECT THE UPPER GREAT LAKES LATER TODAY AND TONIGHT AS IT LIFTS NE. BTWN THE SYSTEMS OVER HUDSON BAY AND THE ROCKIES...SHORTWAVE RIDGING IS SUPPORTING SFC HIGH PRES OVER THE WRN GREAT LAKES EARLY THIS MORNING. EXCELLENT RADIATIONAL COOLING CONDITIONS DURING THE NIGHT HAVE ALLOWED TEMPS TO FALL INTO THE MID 20S TO LWR 30S ACROSS MUCH OF THE INTERIOR OF UPPER MI. HERE AT NWS MQT...THE TEMP SO FAR AS OF 09Z HAS FALLEN TO 30F...MAKING THIS THE FIRST NIGHT THIS AUTUMN WITH A MIN TEMP AT OR BLO FREEZING. THIS TIES 1997 FOR THE LATEST OCCURRENCE OF THE FIRST MIN TEMP AT OR BLO FREEZING IN AUTUMN. SFC HIGH PRES OVER THE AREA WILL SLOWLY MOVE E TODAY WHILE SHORTWAVE OVER THE ROCKIES LIFTS NE INTO THE WRN PLAINS. FORCING ASSOCIATED WITH WAVE WILL REMAIN WELL W AND SW OF HERE TODAY. HOWEVER...RIGHT ENTRANCE OF STRENGTHENING UPPER JET ACROSS NRN ONTARIO/SRN MANITOBA WILL BRING INCREASING UPPER DIVERGENCE OVER THE UPPER MISSISSIPPI VALLEY. UPPER DIVERGENCE ASSOCIATED WITH THE JET IS ALREADY AIDING SOME BANDS OF -SHRA ACROSS ND INTO NW MN EARLY THIS MORNING PER RADAR IMAGERY THOUGH NOT ALL OF IT IS REACHING THE GROUND. THRU LATE AFTN...PLACEMENT OF THE UPPER JET OVER NRN ONTARIO/SRN MANITOBA WILL LEAD TO BEST UPPER DIVERGENCE REMAINING W OF THE FCST AREA AS DOES ISENTROPIC ASCENT AT THE LOWER LEVELS. IN ADDITION...DRY AIR MASS OVER THE AREA (SIMILAR TO 00Z KINL SOUNDING) WILL TAKE SOME TIME TO SATURATE...ESPECIALLY SINCE MAIN MOISTURE TRANSPORT REMAINS TO THE W OVER MN. THUS...PLAN TO MAINTAIN DRY WEATHER ACROSS UPPER MI TODAY...BUT WILL BRING CHC POPS INTO WRN LAKE SUPERIOR MID/LATE AFTN AS ERN FRINGE OF PCPN AREA MAY MAKE SOME PROGRESS INTO DRIER AIR. OTHERWISE...EXPECT A SLOW/STEADY INCREASE IN HIGH/MID CLOUDS THRU THE DAY FROM W TO E AS CLOUDS SPREAD DOWNWIND FROM THE UPPER DIVERGENCE/ISENTROPIC ASCENT AREA TO THE W. GUIDANCE IS WELL CLUSTERED ON MAX TEMPS TODAY...GENERALLY MID/UPPER 50S. AS UPPER JET TO THE N LIFTS SLIGHTLY N AND E...THERE SHOULD BE AN AREA OF -SHRA THAT SHIFTS ACROSS WRN AND NRN LAKE SUPERIOR TONIGHT...PROBABLY TO THE N OF UPPER MI. MEANWHILE...SHORTWAVE OVER THE WRN PLAINS WILL LIFT TO SE SD/SW MN/NW IA BY 12Z TUE WITH HEALTHY FORCING NOTED BY DEEP LAYER QVECTORS SPREADING TOWARD UPPER MI LATE. COMBINED WITH STRONG MOISTURE TRANSPORT AND STRONG ISENTROPIC ASCENT NOTED ON THE 300K SFC...EXPECT SHRA TO ADVANCE NE INTO WRN UPPER MI OVERNIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 426 AM EDT MON OCT 14 2013 MODELS ARE IN DECENT GENERAL AGREEMENT THROUGH THE EXTENDED...BUT LACK AGREEMENT ON SPECIFIC DETAILS /ESPECIALLY FOR TUE-WED/ THAT LEADS TO A MORE UNCERTAIN FORECAST. A NEARLY STACKED LOW PRESSURE SYSTEM WILL BE OVER FAR SW MN AT 12Z TUE...WITH WAA DRIVEN PRECIP OVER THE W AND CENTRAL CWA THROUGH TUE MORNING. AS THE SYSTEM MOVES OVER OR S OF THE CWA /DEPENDING OF MODEL SOLUTION/ THE TRACK OF THE LOW WILL BECOME MORE IMPORTANT AS A TROWAL WILL ACCOMPANY THE LOW. MODELS HAVE SLOWED THE SYSTEM DOWN A BIT FROM 24 HOURS AGO...AND THERE IS STILL DISAGREEMENT ON THE TIMING OF THE SYSTEM. THE 00Z/14 GFS AND 00Z/14 NAM ARE FASTER AND FARTHER N WITH THE TIMING/TRACK...WHICH MOVES THE TROWAL AND ASSOCIATED RAIN E FASTER ON WED. THE 12Z/13 GEM AND 12Z/13 ECMWF ARE SLOWER...BUT STILL DISAGREE ON THE EXACT TRACK. IF THE MORE SOUTHERN SOLUTION OF THE ECMWF VERIFIES...EVEN THOUGH IT IS SLOWER...RAIN WILL NOT LAST AS LONG ON WED AS EVEN THE GFS/NAM ARE SAYING SINCE THE TROWAL WOULD BE S/SE OF THE CWA WED AFTERNOON. THE SLOWER AND FARTHER N SOLUTION OF THE GEM WOULD RESULT IN THE LONGEST LASTING RAIN AS THE TROWAL STAYS OVER THE CWA INTO EARLY WED NIGHT. WILL CONTINUE TO LEAN TOWARD THE SLOWER SOLUTION GIVEN MODEL TRENDS IN THAT DIRECTION. WILL ALSO KEEP POPS HIGH TUE AND TUE NIGHT AS CONFIDENCE OFF AREA WIDE RAIN IS GOOD AT THAT TIME. FOR WED NIGHT INTO EARLY THU...MODELS GIVE A BRIEF REPRIEVE FROM TROUGHING AS A WEAK RIDGE MOVES OVERHEAD. AFTER THAT...A DEEP UPPER LOW WILL MOVE S FROM HUDSON BAY CLOSER TO THE INTERNATIONAL BORDER IN ONTARIO THROUGH SUN. THIS WILL BRING AN INCREASINGLY COLD AIRMASS OVERHEAD THROUGH AT LEAST THE WEEKEND. LOOKS LIKE A COLD FRONT WILL MOVE THROUGH ON THU...BUT PRECIP IS UNCERTAIN ALONG THE FRONT AS MODELS DISAGREE ON HOW MUCH SYNOPTIC FORCING WILL BE AVAILABLE FROM THE UPPER TROUGH MOVING INTO THE REGION. WILL NOT GO HIGHER THAN SLIGHT CHANCE POPS FOR THU. BY 00Z SAT...850MB TEMPS COOL TO AROUND -2C...SO EXPECT LAKE ENHANCED PRECIP ALONG A SECONDARY AND STRONGER COLD FRONT ON FRI GIVEN LAKE SFC TEMPS OF 9C TO 13C. MODELS THEN SHOW 850MB TEMPS DECREASING TO -5C TO -7C FRI NIGHT THROUGH SUN AS MULTIPLE ROUNDS OF UPPER LEVEL ENERGY MOVE THROUGH. WITH THESE COLDER TEMPS...EXPECT PURE LAKE EFFECT PRECIP WITH INCREASES IN INTENSITY WITH ENHANCEMENT FROM ANY CONTRIBUTING SYNOPTIC ENERGY. AS FOR PRECIP TYPE...SHOULD BE ABLE TO SEE ALL SNOW AT NIGHT/MORNING WHEN TEMPS ARE COOLEST FRI NIGHT THROUGH SUN MORNING...AND MAINLY OVER THE HIGHER TERRAIN. OTHERWISE...HIGH TEMPS WILL BE IN THE 40S SO SNOW IS NOT EXPECTED DURING THE WARMER DAYTIME HOURS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 128 PM EDT MON OCT 14 2013 VFR CONDITIONS ARE EXPECTED FOR ALL THREE SITES OVER THE NEXT 12-18HRS...AS A AREA OF HIGH PRESSURE DEPARTS THE AREA. BUT A LOW PRESSURE SYSTEM MOVING OUT OF THE CENTRAL PLAINS AND INTO WISCONSIN TOMORROW WILL PUSH A LARGE AREA OF RAIN NORTHEAST ACROSS UPPER MICHIGAN LATE TONIGHT THROUGH TUESDAY. THUS...EXPECT THE VFR CEILINGS TO QUICKLY FALL TO MVFR AS THE RAIN INCREASES IN INTENSITY. DUE TO THE UNFAVORABLE SOUTHEASTERLY WINDS...OPTED TO LEAVE KIWD AT MVFR CEILINGS BUT LOWERED KSAW TO IFR CEILINGS TOWARDS MID DAY SINCE THAT IS A FAVORABLE DIRECTION FOR THEM. THIS HEAVIEST BAND OF SHOWERS SHOULD LIFT NORTHEAST DURING THE AFTERNOON...BUT STILL THINK SCATTERED SHOWERS AND LOWER CEILINGS WILL LINGER THROUGH TUESDAY NIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 527 AM EDT MON OCT 14 2013 HIGH PRES OVER THE WRN LAKES WILL RESULT IN LIGHT WINDS ACROSS LAKE SUPERIOR...MOSTLY UNDER 15KT THRU MID AFTN. LATER TODAY AND TONIGHT...EASTERLY WINDS WILL BEGIN TO INCREASE FROM W TO E AS THE HIGH SHIFTS E AND LOW PRES LIFTS NE THRU THE PLAINS. BY TUE AFTN...E TO NE WINDS WILL BE INTO THE 20-30KT RANGE OVER WRN LAKE SUPERIOR. AS THE LOW MOVES ENE JUST TO THE S OF LAKE SUPERIOR TUE AFTN THRU WED MORNING...THESE STRONGER WINDS GENERALLY IN THE 20-30KT RANGE WILL SPREAD W TO E ACROSS THE REST OF LAKE SUPERIOR WHILE THE WINDS BACK NORTHERLY. IT`S NOT OUT OF THE QUESTION THAT THERE COULD BE A PERIOD OF GALES TUE NIGHT/WED MORNING ON THE BACKSIDE OF THE LOW. WINDS WILL THEN DIMINISH W TO E WED AFTN/NIGHT AS THE LOW MOVES FARTHER E AND A WEAK SFC HIGH PRES RIDGE ARRIVES. AT THIS TIME...IT APPEARS WINDS WILL MOSTLY BE AOB 20KT THU/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...SRF MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
733 AM EDT MON OCT 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 527 AM EDT MON OCT 14 2013 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL LOW LIFTING NE ACROSS HUDSON BAY WITH A TROF EXTENDING SW INTO THE ROCKIES WHERE ANOTHER SHORTWAVE WAS LOCATED OVER UT/CO. THIS SHORTWAVE WILL BEGIN TO AFFECT THE UPPER GREAT LAKES LATER TODAY AND TONIGHT AS IT LIFTS NE. BTWN THE SYSTEMS OVER HUDSON BAY AND THE ROCKIES...SHORTWAVE RIDGING IS SUPPORTING SFC HIGH PRES OVER THE WRN GREAT LAKES EARLY THIS MORNING. EXCELLENT RADIATIONAL COOLING CONDITIONS DURING THE NIGHT HAVE ALLOWED TEMPS TO FALL INTO THE MID 20S TO LWR 30S ACROSS MUCH OF THE INTERIOR OF UPPER MI. HERE AT NWS MQT...THE TEMP SO FAR AS OF 09Z HAS FALLEN TO 30F...MAKING THIS THE FIRST NIGHT THIS AUTUMN WITH A MIN TEMP AT OR BLO FREEZING. THIS TIES 1997 FOR THE LATEST OCCURRENCE OF THE FIRST MIN TEMP AT OR BLO FREEZING IN AUTUMN. SFC HIGH PRES OVER THE AREA WILL SLOWLY MOVE E TODAY WHILE SHORTWAVE OVER THE ROCKIES LIFTS NE INTO THE WRN PLAINS. FORCING ASSOCIATED WITH WAVE WILL REMAIN WELL W AND SW OF HERE TODAY. HOWEVER...RIGHT ENTRANCE OF STRENGTHENING UPPER JET ACROSS NRN ONTARIO/SRN MANITOBA WILL BRING INCREASING UPPER DIVERGENCE OVER THE UPPER MISSISSIPPI VALLEY. UPPER DIVERGENCE ASSOCIATED WITH THE JET IS ALREADY AIDING SOME BANDS OF -SHRA ACROSS ND INTO NW MN EARLY THIS MORNING PER RADAR IMAGERY THOUGH NOT ALL OF IT IS REACHING THE GROUND. THRU LATE AFTN...PLACEMENT OF THE UPPER JET OVER NRN ONTARIO/SRN MANITOBA WILL LEAD TO BEST UPPER DIVERGENCE REMAINING W OF THE FCST AREA AS DOES ISENTROPIC ASCENT AT THE LOWER LEVELS. IN ADDITION...DRY AIR MASS OVER THE AREA (SIMILAR TO 00Z KINL SOUNDING) WILL TAKE SOME TIME TO SATURATE...ESPECIALLY SINCE MAIN MOISTURE TRANSPORT REMAINS TO THE W OVER MN. THUS...PLAN TO MAINTAIN DRY WEATHER ACROSS UPPER MI TODAY...BUT WILL BRING CHC POPS INTO WRN LAKE SUPERIOR MID/LATE AFTN AS ERN FRINGE OF PCPN AREA MAY MAKE SOME PROGRESS INTO DRIER AIR. OTHERWISE...EXPECT A SLOW/STEADY INCREASE IN HIGH/MID CLOUDS THRU THE DAY FROM W TO E AS CLOUDS SPREAD DOWNWIND FROM THE UPPER DIVERGENCE/ISENTROPIC ASCENT AREA TO THE W. GUIDANCE IS WELL CLUSTERED ON MAX TEMPS TODAY...GENERALLY MID/UPPER 50S. AS UPPER JET TO THE N LIFTS SLIGHTLY N AND E...THERE SHOULD BE AN AREA OF -SHRA THAT SHIFTS ACROSS WRN AND NRN LAKE SUPERIOR TONIGHT...PROBABLY TO THE N OF UPPER MI. MEANWHILE...SHORTWAVE OVER THE WRN PLAINS WILL LIFT TO SE SD/SW MN/NW IA BY 12Z TUE WITH HEALTHY FORCING NOTED BY DEEP LAYER QVECTORS SPREADING TOWARD UPPER MI LATE. COMBINED WITH STRONG MOISTURE TRANSPORT AND STRONG ISENTROPIC ASCENT NOTED ON THE 300K SFC...EXPECT SHRA TO ADVANCE NE INTO WRN UPPER MI OVERNIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 426 AM EDT MON OCT 14 2013 MODELS ARE IN DECENT GENERAL AGREEMENT THROUGH THE EXTENDED...BUT LACK AGREEMENT ON SPECIFIC DETAILS /ESPECIALLY FOR TUE-WED/ THAT LEADS TO A MORE UNCERTAIN FORECAST. A NEARLY STACKED LOW PRESSURE SYSTEM WILL BE OVER FAR SW MN AT 12Z TUE...WITH WAA DRIVEN PRECIP OVER THE W AND CENTRAL CWA THROUGH TUE MORNING. AS THE SYSTEM MOVES OVER OR S OF THE CWA /DEPENDING OF MODEL SOLUTION/ THE TRACK OF THE LOW WILL BECOME MORE IMPORTANT AS A TROWAL WILL ACCOMPANY THE LOW. MODELS HAVE SLOWED THE SYSTEM DOWN A BIT FROM 24 HOURS AGO...AND THERE IS STILL DISAGREEMENT ON THE TIMING OF THE SYSTEM. THE 00Z/14 GFS AND 00Z/14 NAM ARE FASTER AND FARTHER N WITH THE TIMING/TRACK...WHICH MOVES THE TROWAL AND ASSOCIATED RAIN E FASTER ON WED. THE 12Z/13 GEM AND 12Z/13 ECMWF ARE SLOWER...BUT STILL DISAGREE ON THE EXACT TRACK. IF THE MORE SOUTHERN SOLUTION OF THE ECMWF VERIFIES...EVEN THOUGH IT IS SLOWER...RAIN WILL NOT LAST AS LONG ON WED AS EVEN THE GFS/NAM ARE SAYING SINCE THE TROWAL WOULD BE S/SE OF THE CWA WED AFTERNOON. THE SLOWER AND FARTHER N SOLUTION OF THE GEM WOULD RESULT IN THE LONGEST LASTING RAIN AS THE TROWAL STAYS OVER THE CWA INTO EARLY WED NIGHT. WILL CONTINUE TO LEAN TOWARD THE SLOWER SOLUTION GIVEN MODEL TRENDS IN THAT DIRECTION. WILL ALSO KEEP POPS HIGH TUE AND TUE NIGHT AS CONFIDENCE OFF AREA WIDE RAIN IS GOOD AT THAT TIME. FOR WED NIGHT INTO EARLY THU...MODELS GIVE A BRIEF REPRIEVE FROM TROUGHING AS A WEAK RIDGE MOVES OVERHEAD. AFTER THAT...A DEEP UPPER LOW WILL MOVE S FROM HUDSON BAY CLOSER TO THE INTERNATIONAL BORDER IN ONTARIO THROUGH SUN. THIS WILL BRING AN INCREASINGLY COLD AIRMASS OVERHEAD THROUGH AT LEAST THE WEEKEND. LOOKS LIKE A COLD FRONT WILL MOVE THROUGH ON THU...BUT PRECIP IS UNCERTAIN ALONG THE FRONT AS MODELS DISAGREE ON HOW MUCH SYNOPTIC FORCING WILL BE AVAILABLE FROM THE UPPER TROUGH MOVING INTO THE REGION. WILL NOT GO HIGHER THAN SLIGHT CHANCE POPS FOR THU. BY 00Z SAT...850MB TEMPS COOL TO AROUND -2C...SO EXPECT LAKE ENHANCED PRECIP ALONG A SECONDARY AND STRONGER COLD FRONT ON FRI GIVEN LAKE SFC TEMPS OF 9C TO 13C. MODELS THEN SHOW 850MB TEMPS DECREASING TO -5C TO -7C FRI NIGHT THROUGH SUN AS MULTIPLE ROUNDS OF UPPER LEVEL ENERGY MOVE THROUGH. WITH THESE COLDER TEMPS...EXPECT PURE LAKE EFFECT PRECIP WITH INCREASES IN INTENSITY WITH ENHANCEMENT FROM ANY CONTRIBUTING SYNOPTIC ENERGY. AS FOR PRECIP TYPE...SHOULD BE ABLE TO SEE ALL SNOW AT NIGHT/MORNING WHEN TEMPS ARE COOLEST FRI NIGHT THROUGH SUN MORNING...AND MAINLY OVER THE HIGHER TERRAIN. OTHERWISE...HIGH TEMPS WILL BE IN THE 40S SO SNOW IS NOT EXPECTED DURING THE WARMER DAYTIME HOURS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 731 AM EDT MON OCT 14 2013 VFR CONDITIONS WILL CONTINUE AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD AS DRY AIR MASS LINGERS DESPITE EXITING HIGH PRES. HOWEVER...AS LOW PRES SYSTEM ORGANIZING OVER THE WRN PLAINS MOVES NE...SHRA WILL SPREAD NE AND WILL LIKELY REACH KIWD LATE TONIGHT. WITH AN E TO SE DOWNSLOPE WIND...CONDITIONS SHOULDN`T FALL BLO VFR UNTIL SEVERAL HRS AFTER PCPN BEGINS. SHOWERS AND DETERIORATING CONDITIONS ARE EXPECTED AT ALL 3 TERMINALS BEYOND THIS FCST PERIOD DURING THE DAY TUE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 527 AM EDT MON OCT 14 2013 HIGH PRES OVER THE WRN LAKES WILL RESULT IN LIGHT WINDS ACROSS LAKE SUPERIOR...MOSTLY UNDER 15KT THRU MID AFTN. LATER TODAY AND TONIGHT...EASTERLY WINDS WILL BEGIN TO INCREASE FROM W TO E AS THE HIGH SHIFTS E AND LOW PRES LIFTS NE THRU THE PLAINS. BY TUE AFTN...E TO NE WINDS WILL BE INTO THE 20-30KT RANGE OVER WRN LAKE SUPERIOR. AS THE LOW MOVES ENE JUST TO THE S OF LAKE SUPERIOR TUE AFTN THRU WED MORNING...THESE STRONGER WINDS GENERALLY IN THE 20-30KT RANGE WILL SPREAD W TO E ACROSS THE REST OF LAKE SUPERIOR WHILE THE WINDS BACK NORTHERLY. IT`S NOT OUT OF THE QUESTION THAT THERE COULD BE A PERIOD OF GALES TUE NIGHT/WED MORNING ON THE BACKSIDE OF THE LOW. WINDS WILL THEN DIMINISH W TO E WED AFTN/NIGHT AS THE LOW MOVES FARTHER E AND A WEAK SFC HIGH PRES RIDGE ARRIVES. AT THIS TIME...IT APPEARS WINDS WILL MOSTLY BE AOB 20KT THU/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
527 AM EDT MON OCT 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 527 AM EDT MON OCT 14 2013 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL LOW LIFTING NE ACROSS HUDSON BAY WITH A TROF EXTENDING SW INTO THE ROCKIES WHERE ANOTHER SHORTWAVE WAS LOCATED OVER UT/CO. THIS SHORTWAVE WILL BEGIN TO AFFECT THE UPPER GREAT LAKES LATER TODAY AND TONIGHT AS IT LIFTS NE. BTWN THE SYSTEMS OVER HUDSON BAY AND THE ROCKIES...SHORTWAVE RIDGING IS SUPPORTING SFC HIGH PRES OVER THE WRN GREAT LAKES EARLY THIS MORNING. EXCELLENT RADIATIONAL COOLING CONDITIONS DURING THE NIGHT HAVE ALLOWED TEMPS TO FALL INTO THE MID 20S TO LWR 30S ACROSS MUCH OF THE INTERIOR OF UPPER MI. HERE AT NWS MQT...THE TEMP SO FAR AS OF 09Z HAS FALLEN TO 30F...MAKING THIS THE FIRST NIGHT THIS AUTUMN WITH A MIN TEMP AT OR BLO FREEZING. THIS TIES 1997 FOR THE LATEST OCCURRENCE OF THE FIRST MIN TEMP AT OR BLO FREEZING IN AUTUMN. SFC HIGH PRES OVER THE AREA WILL SLOWLY MOVE E TODAY WHILE SHORTWAVE OVER THE ROCKIES LIFTS NE INTO THE WRN PLAINS. FORCING ASSOCIATED WITH WAVE WILL REMAIN WELL W AND SW OF HERE TODAY. HOWEVER...RIGHT ENTRANCE OF STRENGTHENING UPPER JET ACROSS NRN ONTARIO/SRN MANITOBA WILL BRING INCREASING UPPER DIVERGENCE OVER THE UPPER MISSISSIPPI VALLEY. UPPER DIVERGENCE ASSOCIATED WITH THE JET IS ALREADY AIDING SOME BANDS OF -SHRA ACROSS ND INTO NW MN EARLY THIS MORNING PER RADAR IMAGERY THOUGH NOT ALL OF IT IS REACHING THE GROUND. THRU LATE AFTN...PLACEMENT OF THE UPPER JET OVER NRN ONTARIO/SRN MANITOBA WILL LEAD TO BEST UPPER DIVERGENCE REMAINING W OF THE FCST AREA AS DOES ISENTROPIC ASCENT AT THE LOWER LEVELS. IN ADDITION...DRY AIR MASS OVER THE AREA (SIMILAR TO 00Z KINL SOUNDING) WILL TAKE SOME TIME TO SATURATE...ESPECIALLY SINCE MAIN MOISTURE TRANSPORT REMAINS TO THE W OVER MN. THUS...PLAN TO MAINTAIN DRY WEATHER ACROSS UPPER MI TODAY...BUT WILL BRING CHC POPS INTO WRN LAKE SUPERIOR MID/LATE AFTN AS ERN FRINGE OF PCPN AREA MAY MAKE SOME PROGRESS INTO DRIER AIR. OTHERWISE...EXPECT A SLOW/STEADY INCREASE IN HIGH/MID CLOUDS THRU THE DAY FROM W TO E AS CLOUDS SPREAD DOWNWIND FROM THE UPPER DIVERGENCE/ISENTROPIC ASCENT AREA TO THE W. GUIDANCE IS WELL CLUSTERED ON MAX TEMPS TODAY...GENERALLY MID/UPPER 50S. AS UPPER JET TO THE N LIFTS SLIGHTLY N AND E...THERE SHOULD BE AN AREA OF -SHRA THAT SHIFTS ACROSS WRN AND NRN LAKE SUPERIOR TONIGHT...PROBABLY TO THE N OF UPPER MI. MEANWHILE...SHORTWAVE OVER THE WRN PLAINS WILL LIFT TO SE SD/SW MN/NW IA BY 12Z TUE WITH HEALTHY FORCING NOTED BY DEEP LAYER QVECTORS SPREADING TOWARD UPPER MI LATE. COMBINED WITH STRONG MOISTURE TRANSPORT AND STRONG ISENTROPIC ASCENT NOTED ON THE 300K SFC...EXPECT SHRA TO ADVANCE NE INTO WRN UPPER MI OVERNIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 426 AM EDT MON OCT 14 2013 MODELS ARE IN DECENT GENERAL AGREEMENT THROUGH THE EXTENDED...BUT LACK AGREEMENT ON SPECIFIC DETAILS /ESPECIALLY FOR TUE-WED/ THAT LEADS TO A MORE UNCERTAIN FORECAST. A NEARLY STACKED LOW PRESSURE SYSTEM WILL BE OVER FAR SW MN AT 12Z TUE...WITH WAA DRIVEN PRECIP OVER THE W AND CENTRAL CWA THROUGH TUE MORNING. AS THE SYSTEM MOVES OVER OR S OF THE CWA /DEPENDING OF MODEL SOLUTION/ THE TRACK OF THE LOW WILL BECOME MORE IMPORTANT AS A TROWAL WILL ACCOMPANY THE LOW. MODELS HAVE SLOWED THE SYSTEM DOWN A BIT FROM 24 HOURS AGO...AND THERE IS STILL DISAGREEMENT ON THE TIMING OF THE SYSTEM. THE 00Z/14 GFS AND 00Z/14 NAM ARE FASTER AND FARTHER N WITH THE TIMING/TRACK...WHICH MOVES THE TROWAL AND ASSOCIATED RAIN E FASTER ON WED. THE 12Z/13 GEM AND 12Z/13 ECMWF ARE SLOWER...BUT STILL DISAGREE ON THE EXACT TRACK. IF THE MORE SOUTHERN SOLUTION OF THE ECMWF VERIFIES...EVEN THOUGH IT IS SLOWER...RAIN WILL NOT LAST AS LONG ON WED AS EVEN THE GFS/NAM ARE SAYING SINCE THE TROWAL WOULD BE S/SE OF THE CWA WED AFTERNOON. THE SLOWER AND FARTHER N SOLUTION OF THE GEM WOULD RESULT IN THE LONGEST LASTING RAIN AS THE TROWAL STAYS OVER THE CWA INTO EARLY WED NIGHT. WILL CONTINUE TO LEAN TOWARD THE SLOWER SOLUTION GIVEN MODEL TRENDS IN THAT DIRECTION. WILL ALSO KEEP POPS HIGH TUE AND TUE NIGHT AS CONFIDENCE OFF AREA WIDE RAIN IS GOOD AT THAT TIME. FOR WED NIGHT INTO EARLY THU...MODELS GIVE A BRIEF REPRIEVE FROM TROUGHING AS A WEAK RIDGE MOVES OVERHEAD. AFTER THAT...A DEEP UPPER LOW WILL MOVE S FROM HUDSON BAY CLOSER TO THE INTERNATIONAL BORDER IN ONTARIO THROUGH SUN. THIS WILL BRING AN INCREASINGLY COLD AIRMASS OVERHEAD THROUGH AT LEAST THE WEEKEND. LOOKS LIKE A COLD FRONT WILL MOVE THROUGH ON THU...BUT PRECIP IS UNCERTAIN ALONG THE FRONT AS MODELS DISAGREE ON HOW MUCH SYNOPTIC FORCING WILL BE AVAILABLE FROM THE UPPER TROUGH MOVING INTO THE REGION. WILL NOT GO HIGHER THAN SLIGHT CHANCE POPS FOR THU. BY 00Z SAT...850MB TEMPS COOL TO AROUND -2C...SO EXPECT LAKE ENHANCED PRECIP ALONG A SECONDARY AND STRONGER COLD FRONT ON FRI GIVEN LAKE SFC TEMPS OF 9C TO 13C. MODELS THEN SHOW 850MB TEMPS DECREASING TO -5C TO -7C FRI NIGHT THROUGH SUN AS MULTIPLE ROUNDS OF UPPER LEVEL ENERGY MOVE THROUGH. WITH THESE COLDER TEMPS...EXPECT PURE LAKE EFFECT PRECIP WITH INCREASES IN INTENSITY WITH ENHANCEMENT FROM ANY CONTRIBUTING SYNOPTIC ENERGY. AS FOR PRECIP TYPE...SHOULD BE ABLE TO SEE ALL SNOW AT NIGHT/MORNING WHEN TEMPS ARE COOLEST FRI NIGHT THROUGH SUN MORNING...AND MAINLY OVER THE HIGHER TERRAIN. OTHERWISE...HIGH TEMPS WILL BE IN THE 40S SO SNOW IS NOT EXPECTED DURING THE WARMER DAYTIME HOURS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 113 AM EDT MON OCT 14 2013 EXPECT VFR CONDITIONS THROUGH THE NEXT 24 HRS AS HIGH PRES REMAINS IN CONTROL. HIGH CLOUDS WILL BE MOVING INTO THE AREA LATER TODAY AHEAD OF DEVELOPING LOW PRESSURE IN THE PLAINS. RAIN AND LOWER CIGS/VSBYS EXPECTED BY TUESDAY MORNING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 527 AM EDT MON OCT 14 2013 HIGH PRES OVER THE WRN LAKES WILL RESULT IN LIGHT WINDS ACROSS LAKE SUPERIOR...MOSTLY UNDER 15KT THRU MID AFTN. LATER TODAY AND TONIGHT...EASTERLY WINDS WILL BEGIN TO INCREASE FROM W TO E AS THE HIGH SHIFTS E AND LOW PRES LIFTS NE THRU THE PLAINS. BY TUE AFTN...E TO NE WINDS WILL BE INTO THE 20-30KT RANGE OVER WRN LAKE SUPERIOR. AS THE LOW MOVES ENE JUST TO THE S OF LAKE SUPERIOR TUE AFTN THRU WED MORNING...THESE STRONGER WINDS GENERALLY IN THE 20-30KT RANGE WILL SPREAD W TO E ACROSS THE REST OF LAKE SUPERIOR WHILE THE WINDS BACK NORTHERLY. IT`S NOT OUT OF THE QUESTION THAT THERE COULD BE A PERIOD OF GALES TUE NIGHT/WED MORNING ON THE BACKSIDE OF THE LOW. WINDS WILL THEN DIMINISH W TO E WED AFTN/NIGHT AS THE LOW MOVES FARTHER E AND A WEAK SFC HIGH PRES RIDGE ARRIVES. AT THIS TIME...IT APPEARS WINDS WILL MOSTLY BE AOB 20KT THU/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...MRD MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1223 PM CDT MON OCT 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM CDT MON OCT 14 2013 AN ACTIVE 24 HOURS WITH QUITE HIGH MEASURABLE RAIN CHANCES IS ALREADY UNDERWAY ACROSS THE CWA...WITH PLENTY OF FORECAST CHALLENGES RANGING FROM TRYING TO REFINE SHORT-TERM POPS...ASSESSING THE MAGNITUDE OF A POSSIBLE SEVERE WEATHER RISK THIS AFTERNOON-EARLY EVENING...DETERMINING THE EFFECTS OF WIDESPREAD CLOUD COVER/PRECIP ON HIGH TEMPS...AND ALSO TRYING TO DETERMINE HOW CLOSE ESPECIALLY THE NORTHWESTERN CWA MAY COME TO AT LEAST BRIEFLY FLIRTING WITH WIND ADVISORY CRITERIA TONIGHT IN THE WAKE OF THE PASSING LOW. 08Z OBJECTIVE SURFACE ANALYSIS REVEALS A GRADUALLY-TIGHTENING PRESSURE GRADIENT...BETWEEN A ROUGHLY 1031 MILLIBAR HIGH OVER THE GREAT LAKES...AND A 1006 LOW OVER NORTHEAST CO. AS A RESULT...SUSTAINED SOUTHEAST WINDS ACROSS MOST OF THE CWA AT THIS HOUR ARE AVERAGING AT LEAST 10-15 MPH WITH HIGHER GUSTS TO AROUND 20 MPH...ESPECIALLY IN THE WEST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A VIGOROUS MID/UPPER LEVEL TROUGH PLOWING ACROSS THE ROCKIES...WITH ITS 500MB VORT MAX CURRENTLY SWINGING OVER THE 4-CORNERS AREA. UPPER LEVEL FLOW HAS BECOME INCREASINGLY DIFFLUENT OVER THE CENTRAL PLAINS AHEAD OF A 100+KT JET STREAK APPROACHING FROM SOUTHERN CO...AND FARTHER DOWN A 40-50KT SOUTHERLY LOW LEVEL JET IS EVIDENT AT 850MB...RIGHT OVER THE HEART OF CENTRAL/WESTERN NEB AND KS. MUCH AS EXPECTED FOR DAYS NOW...STOUT LOW-MID LEVEL MOISTURE ADVECTION ESPECIALLY EVIDENT IN THE 850-700MB LAYER HAS RESULTED IN A GRADUAL INCREASE IN SHOWER/THUNDERSTORM ACTIVITY WITHIN THE CWA DURING THE NIGHT. OF COURSE...ITS NOT RAINING EVERYWHERE AT ONCE...AND EARLIER ON MOST OF THE PRECIP WAS FOCUSED IN NORTHWESTERN COUNTIES...BUT OVER THE PAST FEW HOURS THE MAIN FOCUS HAS TRANSITIONED TO ROUGHLY THE EASTERN 1/2 OF THE CWA...WITH MUCH OF THE WEST IN AT LEAST A SHORT TERM LULL. ALTHOUGH ITS QUITE POSSIBLE THAT A FEW OF THE STRONGER STORMS EARLY THIS MORNING HAVE PRODUCED/COULD PRODUCE VERY SMALL HAIL...NOT EXPECTING ANY SEVERE STORMS GIVEN MUCAPE IN THE 850-700MB LAYER ONLY AVERAGING A FEW HUNDRED J/KG PER LATEST RAP- BASED MESOANALYSIS. NOT SURPRISINGLY...TEMPS HAVE BEEN FAIRLY STEADY EARLY THIS MORNING UNDER WHAT HAS BECOME WIDESPREAD LOW CLOUD COVER AND SLOWLY-INCREASING DEWPOINTS...WITH MOST ALL PLACES CURRENTLY SOMEWHERE IN THE 50S. FOCUSING ON THE DAYTIME HOURS TODAY THROUGH 00Z/7PM...TOOK A BEST STAB AT 3-HOURLY POP TRENDS...BUT THE BOTTOM LINE IS THAT THE ENTIRE CWA IS SPORTING AN 80-90 PERCENT CHANCE OF MEASURABLE RAIN THROUGH SUNSET...ITS JUST A MATTER OF WHEN IT FALLS AND HOW MUCH FALLS. IN THE BIG PICTURE...THE PRIMARY 500MB VORT MAX ASSOCIATED WITH THE INCOMING TROUGH IS SCHEDULED TO REACH THE NEB PANHANDLE BY MID-DAY AS IT DEEPENS AND SWINGS NORTHEAST IN A NEGATIVELY TILTED FASHION...AND THEN REACHING FAR NORTH CENTRAL NEB BY AROUND SUNSET. IN SUIT...THE ASSOCIATED SURFACE LOW CURRENTLY CENTERED IN NORTHEAST CO IS PROGGED TO SHIFT NORTHEAST AS WELL...BUT SLIGHTLY SOUTHEAST OF THE MID LEVEL LOW TRACK...MEANING THAT IT GENERALLY SKIRTS JUST ALONG THE FAR WEST-CENTRAL/NORTHWEST EDGES OF THE CWA AS IT TRACKS NORTHEAST INTO NORTH CENTRAL NEB BY SUNSET WITH A CENTRAL PRESSURE AROUND 1003MB. MEANWHILE...A STOUT 50+KT LOW LEVEL JET WILL PERSIST OVER THE CWA PRETTY MUCH ALL DAY...WHICH IN TANDEM WITH CONTINUED LOW-MID LEVEL THETA-E ADVECTION SHOULD PROMOTE RATHER WIDESPREAD SHOWERS AND AT LEAST ISOLATED TO SCATTERED EMBEDDED THUNDERSTORMS THROUGH MUCH OF THE DAY. ITS YET TO BE SEEN WHETHER THIS WIDESPREAD PRECIPITATION MAINLY STAYS FOCUSED ACROSS THE EASTERN HALF OF THE CWA AS CURRENTLY HAPPENING...OR EVENTUALLY ALSO DEVELOPS OVER...OR MOVES INTO WESTERN AREAS AS WELL. MODELS VARY...WITH SOME ENDING THE LULL OVER THE WEST BY MID-MORNING...WHILE OTHERS SUCH AS THE LATEST HRRR CONTINUE TO FOCUS ON EASTERN AREAS AT LEAST THROUGH MID-DAY. AT ANY RATE...WOULD BE QUITE SURPRISED IF ANY OF THE CWA GOT THROUGH THE ENTIRE DAY WITHOUT MEASURABLE RAIN...AS MANY EASTERN AREAS COULD EASILY RECEIVE 0.50-0.75 INCH OR MORE THROUGH SUNSET. TURNING TO THE AFTERNOON HOURS...AS HAS ALSO BEEN ADVERTISED FOR A FEW DAYS NOW WE ARE FACING A CONDITIONAL SEVERE WEATHER THREAT...AS SPC HAS THE MAJORITY OF THE CWA IN A DAY 1 SLIGHT RISK AREA. THE MILLION DOLLAR QUESTION HERE IS...HOW MUCH CLEARING WILL TAKE PLACE JUST WEST OF...AND POSSIBLY INTO THE FAR SOUTHWESTERN PORTIONS OF THE CWA THIS AFTERNOON UNDER THE INVADING MID LEVEL DRY SLOT AND JUST AHEAD OF THE INVADING COLD FRONT/DRYLINE COMBO...TO PROMOTE SUFFICIENT DESTABILIZATION FOR SEVERE STORMS. FOLLOWING THE LEAD OF THE LATEST RAP...THE VAST MAJORITY OF THE CWA WILL REMAIN LOCKED UNDER LOW CLOUDS AND SCATTERED TO WIDESPREAD ELEVATED PRECIP THROUGH NEARLY THE ENTIRE DAY...WITH LIKELY NOTHING MORE THAN A HIT AND MISS THREAT OF SMALL HAIL POSSIBLY UP TO AROUND DIME SIZE. HOWEVER...BY MID-LATE AFTERNOON...THE RAP BRINGS A NARROW NORTH-SOUTH CORRIDOR OF LOW-LEVEL CAPE POTENTIALLY INTO THE 1000-1500 J/KG RANGE INTO MAINLY THE WESTERN 1/4 OF THE CWA. AS A RESULT...AND AS DEPICTED FAIRLY WELL BY THE 00Z RUNS OF THE 4KM WRF-NMM AND ARW AND ALSO THE LATEST HRRR...A LINE OF FAST MOVING STRONG TO POTENTIALLY SEVERE STORMS COULD SWEEP FROM WEST- EAST ACROSS MUCH OF THE CWA MAINLY BETWEEN 4PM-9PM...BUT LIKELY GRADUALLY LOSING STEAM AS IT DOES SO. ALTHOUGH LOW LEVEL SHEAR WILL BE STRONG...THUS MEANING THAT A BRIEF TORNADO THREAT IS NON- ZERO...EXPECT SYNOPTIC FORCING TO BE STRONG ENOUGH TO FORCE A LINEAR MODE FAIRLY QUICKLY...WITH THE MAIN THREAT BEING WINDS GUSTS TO AT LEAST 60 MPH...AND MAYBE SOME MARGINALLY SEVERE HAIL TO AROUND QUARTER SIZE. ALTHOUGH THE SPC SLIGHT RISK AREA COVERS NEARLY THE ENTIRE CWA...WILL BE FOCUSING THE LOCAL HAZARDOUS WEATHER OUTLOOK MAINLY ON THE SOUTHWEST HALF OF THE CWA...OR ROUGHLY SOUTHWEST OF A LOUP CITY-BELOIT LINE WHERE INSTABILITY SHOULD BE MAXIMIZED BEFORE IT DROPS OFF FARTHER EAST AS NIGHT FALLS. TURNING BRIEFLY TO OTHER ELEMENTS TODAY...HIGH TEMPERATURES WILL BE QUITE TRICKY AND OBVIOUSLY VERY DEPENDENT ON HOW MUCH PRECIP IS FALLING AND WHETHER ANY CLEARING TAKES PLACE IN THE SOUTHWEST...BUT BASED ON A VARIED BLEND OF SHORT TERM MODELS/GUIDANCE HAVE A RANGE FROM ONLY MID-UPPER 50S NORTH TO MID- UPPER 60S SOUTHWEST...WHICH IS A BIT COOLER THAN A STRAIGHT MET/MAV GUIDANCE BLEND AND COUNTS ON LOW CLOUDS HOLDING FIRM ACROSS MOST OF THE AREA. WIND-WISE TODAY...ALTHOUGH CERTAINLY QUITE BREEZY WITH SUSTAINED SOUTH-SOUTHEAST SPEEDS AVERAGING 20-25 MPH WITH GUSTS TO AROUND 30 MPH AHEAD OF THE APPROACHING COLD FRONT...NOT EXPECTING SUSTAINED SPEEDS TO BREACH ADVISORY CRITERIA OF 30+ MPH. TURNING TO THE TONIGHT PERIOD/7PM-7AM/...THE MAIN FOCUS IS ON HOW QUICKLY CONVECTION VACATES THE AREA...AND HOW STRONG WEST- NORTHWEST WINDS BECOME. ON THE BIG PICTURE...THERE IS GOOD AGREEMENT THAT THE CENTER OF THE CLOSED MID LEVEL LOW WILL ONLY SLOWLY MIGRATE FROM FAR NORTH CENTRAL NEB TO NEAR SIOUX FALLS...WHILE THE ATTENDANT SURFACE LOW FOLLOWS A SIMILAR PATH AND MAINTAINS A SIMILAR CENTRAL PRESSURE AROUND 1003MB. IN THE STOUT COLD AIR ADVECTION REGIME BEHIND THE DEPARTING LOW...AND IN AN ENHANCED PRESSURE GRADIENT BETWEEN THE SURFACE LOW AND AN EXPANSIVE HIGH NOSING INTO THE REGION FROM THE NORTHERN ROCKIES...ITS QUITE POSSIBLE THAT ESPECIALLY THE NORTHWEST HALF OF THE CWA MAY BE OVERALL-WINDIER TONIGHT THAN THEY ARE DURING THE DAY TODAY...EXCEPT THIS TIME OUT OF THE WEST-NORTHWEST BEHIND THE QUICKLY PASSING COLD FRONT...WHICH IS SLATED TO CRUISE ACROSS THE CWA GENERALLY BETWEEN 5-11PM. ALTHOUGH ITS NOT OUT OF THE QUESTION THAT THE LATEST SUITE OF MODELS/GUIDANCE ARE UNDER-DOING WIND SPEEDS A BIT...AT LEAST FOR NOW EXPECT SUSTAINED SPEEDS TO ONLY AVERAGE IN THE 20-25 MPH RANGE WITH GUSTS OF 30-35 MPH...AND THUS FALLING AT LEAST SLIGHTLY SHORT OF ADVISORY CRITERIA. NEIGHBORING OFFICES TO THE WEST HAVE ISSUED WIND HEADLINES FOR PORTIONS OF TODAY/TONIGHT...BUT AT THIS POINT JUST DON/T SEE THE LOCAL AREA BEING QUITE WINDY ENOUGH TO JUSTIFY AN ADVISORY...ALTHOUGH OF COURSE LATER SHIFTS WILL HAVE TO RE-EVALUATE THIS. OTHERWISE...IN TERMS OF PRECIP TRENDS...HAVE SLIGHTLY SPED UP THE DEPARTURE OF SHOWERS/STORMS...WITH MUCH OF THE WESTERN 1/2 OF THE CWA LIKELY DRIED OUT BY AROUND SUNSET...WHILE LIKELY POPS CONTINUE IN EASTERN COUNTIES THROUGH 02Z/9PM BEFORE QUICKLY DIMINISHING AND ENDING BY MIDNIGHT. ITS POSSIBLE THAT STORMS COULD CARRY AT LEAST A MARGINAL SEVERE THREAT UNTIL THEY DEPART EASTERN AREAS...BUT WOULD EXPECT THE MAIN THREAT TO DIMINISH POST-SUNSET. ALTHOUGH THE MAIN AREA OF PRECIP WILL VACATE THE AREA THIS EVENING...DID INTRODUCE A SLIGHT CHANCE OF LIGHT RAIN TO FAR NORTHERN ZONES THROUGH THE LATE EVENING/OVERNIGHT HOURS TO ACCOUNT FOR PRECIPITATION POSSIBLY BARELY BRUSHING THE CWA ON THE SOUTH-END OF THE WRAP-AROUND SHIELD. THE VAST MAJORITY OF THIS SHOULD FOCUS ACROSS FAR NORTHERN NEB HOWEVER. MADE LITTLE CHANGE TO OVERNIGHT LOWS...WITH MOST OF THE CWA BOTTOMING OUT IN THE 39-42 RANGE BY SUNRISE TUESDAY...ALTHOUGH ESPECIALLY THE NORTHWEST HALF OF THE AREA MAY BE HELD UP A BIT BY PLENTY OF LOW STRATUS WRAPPING BACK SOUTHWARD INTO THE AREA. THOSE VENTURING OUT LATE TONIGHT/EARLY TUESDAY WILL DEFINITELY NOTICE A BITE TO THE AIR...WITH WIND CHILL READINGS WELL DOWN INTO THE 30S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 445 AM CDT MON OCT 14 2013 PRIMARY CONCERNS WILL BE WINDY CONDITIONS ON TUESDAY AND LOW TEMPERATURES WITH FROST/FREEZE CHANCES ON WEDNESDAY AND THURSDAY MORNING. BUSY PATTERN STARTING OUT TUESDAY MORNING AS 500MB CLOSED LOW IS EXPECTED TO BE NEAR THE SDAK/MN BORDER WITH THE SYSTEM STACKED AS SURFACE LOW SHOULD BE JUST A TAD SOUTHEAST OF THE UPPER LOW POSITION. IN ADDITION TO THE UPPER LOW...TROUGHINESS IS EXPECTED TO EXTEND WESTWARD TOWARD THE CENTRAL ROCKIES. AS NOTED ABOVE...EXPECT WINDY CONDITIONS DURING THE DAYTIME TUESDAY AS WE SIT IN BETWEEN A WOUND UP SURFACE LOW NEAR THE MN/IA BORDER AND A STRONG HIGH PRESSURE BUILDING INTO CENTRAL WYOMING. THIS WILL RESULT IN A 20MB PRESSURE GRADIENT ACROSS NEBRASKA. SHOULD SEE SUSTAINED 25 MPH WINDS AT LEAST AND MAY BE APPROACHING ADVISORY CRITERIA ESPECIALLY IN THE NORTHERN HALF OF THE CWA FROM MID MORNING TO MID AFTERNOON. SOME LIGHT RAIN ALSO POSSIBLE ON TUESDAY IN THE NORTHERN QUARTER OF THE CWA WRAPPING AROUND THE LOW PRESSURE. IF WE DO GET ANY IT SHOULD NOT AMOUNT TO MUCH MORE THAN ONE OR TWO HUNDREDTHS. BY WEDNESDAY MORNING THE SURFACE LOW WILL HAVE MOVED INTO THE GREAT LAKES REGION WITH THE SURFACE HIGH BUILDING INTO OUR AREA. THIS WILL BRING LIGHTER WINDS AND ALSO EXPECTING SKIES TO CLEAR OUT...SO WITH DEWPOINTS IN THE UPPER 20S TO NEAR 30...MUCH OF THE CWA STANDS A DECENT CHANCE OF SEEING FROST WED MORNING. ON THURSDAY ANOTHER MID LEVEL WAVE WILL SLIDE ACROSS DRAGGING A COLD FRONT THROUGH THE CWA. DOESN`T APPEAR TO BE MUCH MOISTURE WITH THIS SYSTEM AND WILL KEEP FORECAST DRY. FRIDAY IS A LITTLE MORE INTERESTING AS A DEEP UPPER LOW SWINGS ACROSS CANADA AND THE NORTHERN PART OF THE U.S. THE EC MODELS BRINGS DOWN MUCH COLDER AIR THAN THE OPERATIONAL GFS. IT ALSO BRINGS A STRONG MID LEVEL WAVE DOWN THE BACKSIDE OF THE LOW ON FRIDAY AND GENERATES SOME MODERATE QPF WITH IT. THE GFS NOT SHOWING THIS AND THE GEM IS ALSO UNDERPLAYING THIS FEATURE. CHECKING THE ALL BLEND POPS...THEY ARE ONLY IN THE 15 TO 20 PERCENT RANGE FOR THE DAYTIME FRIDAY. BACK TO THE EC...IF ONE WERE TO ONLY LOOK AT 1000-500 MB THICKNESSES...THERE MAY BE CAUSE FOR CONCERN AS THE EC IS SHOWING THICKNESSES CONDUCIVE FOR SNOW. HOWEVER...A CLOSER EXAMINATION OF THE FORECAST SOUNDINGS FROM THE EC SHOWS SURFACE TEMPS IN THE UPPER 30S FRIDAY MORNING. ALSO THE GROUND SHOULD BE FAIRLY WARM SINCE HIGHS ON WED AND THURSDAY WILL BE NEAR 60. SO IF THE EC DOES VERIFY WITH THE MID LEVEL WAVE...WOULD EXPECT ANY PRECIP THAT OCCURS TO BE MORE OF A COLD RAIN. OF COURSE THIS WILL NEED TO BE MONITORED OVER THE NEXT FEW DAYS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1223 PM CDT MON OCT 14 2013 SHOWERS AND A FEW THUNDERSTORMS ARE GOING TO BE MOVING THROUGH THE KGRI TERMINAL AREA THIS AFTERNOON AND EARLY THIS EVENING BUT SHOULD BE OUT OF THE AREA LATER THIS EVENING. IFR CEILINGS ARE EXPECTED THROUGH THE AFTERNOON BUT SHOULD LIFT AS THE THUNDERSTORMS MOVE THROUGH THE AREA. A COLD FRONT WILL MOVE THROUGH THE AREA THIS EVENING TURNING WINDS FROM SOUTH TO NORTHWEST. IN ADDITION WINDS WILL BE FAIRLY STRONG DURING THE NIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...JCB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1222 PM CDT MON OCT 14 2013 .AVIATION... 18Z TAFS FOR KOFK...KOMA AND KLNK. BANDS OF SHOWERS/TSTMS WILL CONTINUE TO ROTATE ACROSS ERN NEBRASKA AS A STRONG UPPER SYSTEM MOVES INTO ERN SD BY EARLY TONIGHT. DRIER AIR OVER WRN IA WAS KEEPING CIGS/VSBYS A BIT HIGHER AT KLNK/KOMA BUT BOTH SHOULD BE LOWERING AS LOW LEVEL MOISTURE WORKS EAST LATER THIS AFTN/EARLY EVENING AND STRONGER CONVECTIVE LINES ALSO MOVE EAST. BULK OF CONVECTION SHOULD BE SHIFTING EAST OF TAF SITES BY 02-04Z. STRONG LOW LEVEL JET COULD BRING A PERIOD OF LOW LEVEL WIND SHEAR EARLY AND COULD ALSO PROVIDE SOME STRONG WIND GUSTS IN STRONGER THUNDERSTORMS THROUGH EARLY EVENING. WRLY WINDS BEHIND COLD FRONT THIS EVENING COULD LIMIT SRN EXTENSION OF LOWER CIGS UNTIL LATER IN TAF PERIOD...BUT MVFR CIGS WERE MAINTAINED IN OUT PERIOD FOR NOW. CHERMOK && .PREV DISCUSSION... /ISSUED 355 AM CDT MON OCT 14 2013/ DISCUSSION... MAIN FORECAST CHALLENGE IS TIMING THE RAIN TODAY THROUGH TUESDAY...AND DETERMINING RAINFALL AMOUNTS. AT 08Z...SHOWERS WITH A FEW THUNDERSTORMS WERE MOVING THROUGH PARTS OF NEBRASKA...THEN EXTENDED SOUTHWEST THROUGH COLORADO AND INTO NORTHERN NEW MEXICO. THIS AREA OF PRECIPITATION WAS IN RESPONSE TO A DEEP UPPER LOW SPINNING OVER UTAH PER WATER VAPOR IMAGERY. ASSOCIATED WITH THE LOW WAS AN IMPRESSIVE JET MAX OF AROUND 145 KNOTS AS INDICATED BY THE RAP MODEL ANALYSIS NEAR THE COLORADO- NEW MEXICO BORDER. NUMEROUS LIGHTNING STRIKES WERE NOTED WITHIN THIS PRECIPITATION AREA. THE SURFACE CYCLOGENESIS RESPONSE TO THE UPPER LOW WAS MAXIMIZED FROM SOUTHEAST WYOMING INTO SOUTHWEST SOUTH DAKOTA WHERE 3 HOURLY PRESSURE FALLS WERE 2-3MB. BASED ON THE 100 METER 500MB HEIGHT RISES ON THE BACK SIDE OF THE UPPER TROUGH...THE EXPECTED SCENARIO IS FOR THE UPPER LOW TO MOVE FROM UTAH INTO THE NEBRASKA PANHANDLE BY THIS AFTERNOON. THAT WILL PIVOT THE JET AXIS TO A MORE EAST-WEST ORIENTATION...POSITIONING IT ACROSS SOUTHEAST COLORADO-SOUTHERN KANSAS. EXPECT STRONG UPWARD FORCING DUE TO A COMBINATION OF: THE UPPER DIVERGENCE FROM THE LEFT FRONT EXIT REGION OF THE JET MAX...STRONG DPVA AHEAD OF THE UPPER LOW...ISENTROPIC LIFT IN THE WARM CONVEYER BELT REGION...AND CONTINUED SURFACE CYCLOGENESIS. ALL OF THIS POINTS TO A WELL-DEFINED EXTRATROPICAL CYCLONE PATTERN MOVING THROUGH THE PLAINS TODAY AND THIS EVENING...WITH A SURFACE COLD FRONT MOVING THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA TONIGHT. IN THESE SCENARIOS WE CAN PLAN ON SOMEWHAT HEAVY RAINS AHEAD OF THE LOW DURING THE DAY TODAY AND INTO THE EVENING...THEN THE DRY SLOT PUSHING INTO THE REGION OVERNIGHT TONIGHT. THEN AS THE UPPER LOW MOVES NORTHEAST OF THE REGION...SCATTERED SHOWERS SHOULD OCCUR ON THE BACK SIDE OF THE LOW IN THE DEFORMATION ZONE. RAINFALL AMOUNTS OF 2 INCHES WILL BE POSSIBLE NEAR THE SOUTH DAKOTA BORDER...WITH CLOSER TO 0.5 INCH NEAR THE MISSOURI BORDER...AND 1-1.5 INCHES NEAR I-80. THESE AMOUNTS ARE SUPPORTED BY FAIRLY GOOD MODEL AGREEMENT WITH THE OVERALL PATTERN AS WELL AS THE MODEL RAINFALL. THIS ACTIVE PATTERN SHOULD BE ACCOMPANIED BY A STRONG SOUTHERLY LOW LEVEL JET OF AROUND 60 KNOTS THIS AFTERNOON AND EVENING...THEN 40-45 KNOTS OUT OF THE NORTHWEST TUESDAY. THUNDERSTORMS THAT DEVELOP ON THE EASTERN EDGE OF THE DRY SLOT OVER SOUTH CENTRAL NEBRASKA THIS AFTERNOON/EVENING MAY BE QUITE STRONG AND COULD MOVE NORTHEAST INTO AREAS GENERALLY WEST AND SOUTH OF NORFOLK. BEHIND THE COLD FRONT...TEMPERATURES WILL BE ABOUT 10 DEGREES COLDER TUESDAY THAN TODAY WITH GUSTY NORTHWEST WINDS...CLOUDS...AND SCATTERED LIGHT SHOWERS ESPECIALLY IN NORTHEAST NEBRASKA. SURFACE HIGH PRESSURE MOVES IN WEDNESDAY WITH COOL/QUIET WEATHER. THE PATTERN OVER NORTH AMERICA SETTLES INTO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST WITH A BROAD LONGWAVE TROUGH FROM HUDSON BAY INTO THE SOUTHERN US...AND THIS KEEPS THE CENTRAL PLAINS IN A COOL NORTHWEST FLOW REGIME INTO NEXT WEEK. NIETFELD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
622 AM CDT MON OCT 14 2013 .AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. NUMEROUS AVIATION CONCERNS DURING THE PERIOD. THIS IS SHAPING UP TO BE WET DAY WITH SHOWERS AND THUNDERSTORMS THROUGH AT LEAST THE FIRST 12 TO 15 HOURS OF THE FORECAST PERIOD. GUSTY SOUTHEAST WINDS AT ALL TAF SITES...BECOMING WEST IN THE LATTER HALF OF THE FORECAST...AND EVENTUALLY NORTHWEST TOWARD THE END OF THE PERIOD. CEILINGS EVENTUALLY BECOMING MVFR...AND POSSIBLY IFR AT KOFK. LOW LEVEL WIND SHEAR WILL ALSO BE AN ISSUE AT ALL TAF SITES THIS MORNING. DEWALD && .PREV DISCUSSION... /ISSUED 355 AM CDT MON OCT 14 2013/ DISCUSSION... MAIN FORECAST CHALLENGE IS TIMING THE RAIN TODAY THROUGH TUESDAY...AND DETERMINING RAINFALL AMOUNTS. AT 08Z...SHOWERS WITH A FEW THUNDERSTORMS WERE MOVING THROUGH PARTS OF NEBRASKA...THEN EXTENDED SOUTHWEST THROUGH COLORADO AND INTO NORTHERN NEW MEXICO. THIS AREA OF PRECIPITATION WAS IN RESPONSE TO A DEEP UPPER LOW SPINNING OVER UTAH PER WATER VAPOR IMAGERY. ASSOCIATED WITH THE LOW WAS AN IMPRESSIVE JET MAX OF AROUND 145 KNOTS AS INDICATED BY THE RAP MODEL ANALYSIS NEAR THE COLORADO- NEW MEXICO BORDER. NUMEROUS LIGHTNING STRIKES WERE NOTED WITHIN THIS PRECIPITATION AREA. THE SURFACE CYCLOGENESIS RESPONSE TO THE UPPER LOW WAS MAXIMIZED FROM SOUTHEAST WYOMING INTO SOUTHWEST SOUTH DAKOTA WHERE 3 HOURLY PRESSURE FALLS WERE 2-3MB. BASED ON THE 100 METER 500MB HEIGHT RISES ON THE BACK SIDE OF THE UPPER TROUGH...THE EXPECTED SCENARIO IS FOR THE UPPER LOW TO MOVE FROM UTAH INTO THE NEBRASKA PANHANDLE BY THIS AFTERNOON. THAT WILL PIVOT THE JET AXIS TO A MORE EAST-WEST ORIENTATION...POSITIONING IT ACROSS SOUTHEAST COLORADO-SOUTHERN KANSAS. EXPECT STRONG UPWARD FORCING DUE TO A COMBINATION OF: THE UPPER DIVERGENCE FROM THE LEFT FRONT EXIT REGION OF THE JET MAX...STRONG DPVA AHEAD OF THE UPPER LOW...ISENTROPIC LIFT IN THE WARM CONVEYER BELT REGION...AND CONTINUED SURFACE CYCLOGENESIS. ALL OF THIS POINTS TO A WELL-DEFINED EXTRATROPICAL CYCLONE PATTERN MOVING THROUGH THE PLAINS TODAY AND THIS EVENING...WITH A SURFACE COLD FRONT MOVING THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA TONIGHT. IN THESE SCENARIOS WE CAN PLAN ON SOMEWHAT HEAVY RAINS AHEAD OF THE LOW DURING THE DAY TODAY AND INTO THE EVENING...THEN THE DRY SLOT PUSHING INTO THE REGION OVERNIGHT TONIGHT. THEN AS THE UPPER LOW MOVES NORTHEAST OF THE REGION...SCATTERED SHOWERS SHOULD OCCUR ON THE BACK SIDE OF THE LOW IN THE DEFORMATION ZONE. RAINFALL AMOUNTS OF 2 INCHES WILL BE POSSIBLE NEAR THE SOUTH DAKOTA BORDER...WITH CLOSER TO 0.5 INCH NEAR THE MISSOURI BORDER...AND 1-1.5 INCHES NEAR I-80. THESE AMOUNTS ARE SUPPORTED BY FAIRLY GOOD MODEL AGREEMENT WITH THE OVERALL PATTERN AS WELL AS THE MODEL RAINFALL. THIS ACTIVE PATTERN SHOULD BE ACCOMPANIED BY A STRONG SOUTHERLY LOW LEVEL JET OF AROUND 60 KNOTS THIS AFTERNOON AND EVENING...THEN 40-45 KNOTS OUT OF THE NORTHWEST TUESDAY. THUNDERSTORMS THAT DEVELOP ON THE EASTERN EDGE OF THE DRY SLOT OVER SOUTH CENTRAL NEBRASKA THIS AFTERNOON/EVENING MAY BE QUITE STRONG AND COULD MOVE NORTHEAST INTO AREAS GENERALLY WEST AND SOUTH OF NORFOLK. BEHIND THE COLD FRONT...TEMPERATURES WILL BE ABOUT 10 DEGREES COLDER TUESDAY THAN TODAY WITH GUSTY NORTHWEST WINDS...CLOUDS...AND SCATTERED LIGHT SHOWERS ESPECIALLY IN NORTHEAST NEBRASKA. SURFACE HIGH PRESSURE MOVES IN WEDNESDAY WITH COOL/QUIET WEATHER. THE PATTERN OVER NORTH AMERICA SETTLES INTO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST WITH A BROAD LONGWAVE TROUGH FROM HUDSON BAY INTO THE SOUTHERN US...AND THIS KEEPS THE CENTRAL PLAINS IN A COOL NORTHWEST FLOW REGIME INTO NEXT WEEK. NIETFELD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
607 AM CDT MON OCT 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM CDT MON OCT 14 2013 AN ACTIVE 24 HOURS WITH QUITE HIGH MEASURABLE RAIN CHANCES IS ALREADY UNDERWAY ACROSS THE CWA...WITH PLENTY OF FORECAST CHALLENGES RANGING FROM TRYING TO REFINE SHORT-TERM POPS...ASSESSING THE MAGNITUDE OF A POSSIBLE SEVERE WEATHER RISK THIS AFTERNOON-EARLY EVENING...DETERMINING THE EFFECTS OF WIDESPREAD CLOUD COVER/PRECIP ON HIGH TEMPS...AND ALSO TRYING TO DETERMINE HOW CLOSE ESPECIALLY THE NORTHWESTERN CWA MAY COME TO AT LEAST BRIEFLY FLIRTING WITH WIND ADVISORY CRITERIA TONIGHT IN THE WAKE OF THE PASSING LOW. 08Z OBJECTIVE SURFACE ANALYSIS REVEALS A GRADUALLY-TIGHTENING PRESSURE GRADIENT...BETWEEN A ROUGHLY 1031 MILLIBAR HIGH OVER THE GREAT LAKES...AND A 1006 LOW OVER NORTHEAST CO. AS A RESULT...SUSTAINED SOUTHEAST WINDS ACROSS MOST OF THE CWA AT THIS HOUR ARE AVERAGING AT LEAST 10-15 MPH WITH HIGHER GUSTS TO AROUND 20 MPH...ESPECIALLY IN THE WEST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A VIGOROUS MID/UPPER LEVEL TROUGH PLOWING ACROSS THE ROCKIES...WITH ITS 500MB VORT MAX CURRENTLY SWINGING OVER THE 4-CORNERS AREA. UPPER LEVEL FLOW HAS BECOME INCREASINGLY DIFFLUENT OVER THE CENTRAL PLAINS AHEAD OF A 100+KT JET STREAK APPROACHING FROM SOUTHERN CO...AND FARTHER DOWN A 40-50KT SOUTHERLY LOW LEVEL JET IS EVIDENT AT 850MB...RIGHT OVER THE HEART OF CENTRAL/WESTERN NEB AND KS. MUCH AS EXPECTED FOR DAYS NOW...STOUT LOW-MID LEVEL MOISTURE ADVECTION ESPECIALLY EVIDENT IN THE 850-700MB LAYER HAS RESULTED IN A GRADUAL INCREASE IN SHOWER/THUNDERSTORM ACTIVITY WITHIN THE CWA DURING THE NIGHT. OF COURSE...ITS NOT RAINING EVERYWHERE AT ONCE...AND EARLIER ON MOST OF THE PRECIP WAS FOCUSED IN NORTHWESTERN COUNTIES...BUT OVER THE PAST FEW HOURS THE MAIN FOCUS HAS TRANSITIONED TO ROUGHLY THE EASTERN 1/2 OF THE CWA...WITH MUCH OF THE WEST IN AT LEAST A SHORT TERM LULL. ALTHOUGH ITS QUITE POSSIBLE THAT A FEW OF THE STRONGER STORMS EARLY THIS MORNING HAVE PRODUCED/COULD PRODUCE VERY SMALL HAIL...NOT EXPECTING ANY SEVERE STORMS GIVEN MUCAPE IN THE 850-700MB LAYER ONLY AVERAGING A FEW HUNDRED J/KG PER LATEST RAP- BASED MESOANALYSIS. NOT SURPRISINGLY...TEMPS HAVE BEEN FAIRLY STEADY EARLY THIS MORNING UNDER WHAT HAS BECOME WIDESPREAD LOW CLOUD COVER AND SLOWLY-INCREASING DEWPOINTS...WITH MOST ALL PLACES CURRENTLY SOMEWHERE IN THE 50S. FOCUSING ON THE DAYTIME HOURS TODAY THROUGH 00Z/7PM...TOOK A BEST STAB AT 3-HOURLY POP TRENDS...BUT THE BOTTOM LINE IS THAT THE ENTIRE CWA IS SPORTING AN 80-90 PERCENT CHANCE OF MEASURABLE RAIN THROUGH SUNSET...ITS JUST A MATTER OF WHEN IT FALLS AND HOW MUCH FALLS. IN THE BIG PICTURE...THE PRIMARY 500MB VORT MAX ASSOCIATED WITH THE INCOMING TROUGH IS SCHEDULED TO REACH THE NEB PANHANDLE BY MID-DAY AS IT DEEPENS AND SWINGS NORTHEAST IN A NEGATIVELY TILTED FASHION...AND THEN REACHING FAR NORTH CENTRAL NEB BY AROUND SUNSET. IN SUIT...THE ASSOCIATED SURFACE LOW CURRENTLY CENTERED IN NORTHEAST CO IS PROGGED TO SHIFT NORTHEAST AS WELL...BUT SLIGHTLY SOUTHEAST OF THE MID LEVEL LOW TRACK...MEANING THAT IT GENERALLY SKIRTS JUST ALONG THE FAR WEST-CENTRAL/NORTHWEST EDGES OF THE CWA AS IT TRACKS NORTHEAST INTO NORTH CENTRAL NEB BY SUNSET WITH A CENTRAL PRESSURE AROUND 1003MB. MEANWHILE...A STOUT 50+KT LOW LEVEL JET WILL PERSIST OVER THE CWA PRETTY MUCH ALL DAY...WHICH IN TANDEM WITH CONTINUED LOW-MID LEVEL THETA-E ADVECTION SHOULD PROMOTE RATHER WIDESPREAD SHOWERS AND AT LEAST ISOLATED TO SCATTERED EMBEDDED THUNDERSTORMS THROUGH MUCH OF THE DAY. ITS YET TO BE SEEN WHETHER THIS WIDESPREAD PRECIPITATION MAINLY STAYS FOCUSED ACROSS THE EASTERN HALF OF THE CWA AS CURRENTLY HAPPENING...OR EVENTUALLY ALSO DEVELOPS OVER...OR MOVES INTO WESTERN AREAS AS WELL. MODELS VARY...WITH SOME ENDING THE LULL OVER THE WEST BY MID-MORNING...WHILE OTHERS SUCH AS THE LATEST HRRR CONTINUE TO FOCUS ON EASTERN AREAS AT LEAST THROUGH MID-DAY. AT ANY RATE...WOULD BE QUITE SURPRISED IF ANY OF THE CWA GOT THROUGH THE ENTIRE DAY WITHOUT MEASURABLE RAIN...AS MANY EASTERN AREAS COULD EASILY RECEIVE 0.50-0.75 INCH OR MORE THROUGH SUNSET. TURNING TO THE AFTERNOON HOURS...AS HAS ALSO BEEN ADVERTISED FOR A FEW DAYS NOW WE ARE FACING A CONDITIONAL SEVERE WEATHER THREAT...AS SPC HAS THE MAJORITY OF THE CWA IN A DAY 1 SLIGHT RISK AREA. THE MILLION DOLLAR QUESTION HERE IS...HOW MUCH CLEARING WILL TAKE PLACE JUST WEST OF...AND POSSIBLY INTO THE FAR SOUTHWESTERN PORTIONS OF THE CWA THIS AFTERNOON UNDER THE INVADING MID LEVEL DRY SLOT AND JUST AHEAD OF THE INVADING COLD FRONT/DRYLINE COMBO...TO PROMOTE SUFFICIENT DESTABILIZATION FOR SEVERE STORMS. FOLLOWING THE LEAD OF THE LATEST RAP...THE VAST MAJORITY OF THE CWA WILL REMAIN LOCKED UNDER LOW CLOUDS AND SCATTERED TO WIDESPREAD ELEVATED PRECIP THROUGH NEARLY THE ENTIRE DAY...WITH LIKELY NOTHING MORE THAN A HIT AND MISS THREAT OF SMALL HAIL POSSIBLY UP TO AROUND DIME SIZE. HOWEVER...BY MID-LATE AFTERNOON...THE RAP BRINGS A NARROW NORTH-SOUTH CORRIDOR OF LOW-LEVEL CAPE POTENTIALLY INTO THE 1000-1500 J/KG RANGE INTO MAINLY THE WESTERN 1/4 OF THE CWA. AS A RESULT...AND AS DEPICTED FAIRLY WELL BY THE 00Z RUNS OF THE 4KM WRF-NMM AND ARW AND ALSO THE LATEST HRRR...A LINE OF FAST MOVING STRONG TO POTENTIALLY SEVERE STORMS COULD SWEEP FROM WEST- EAST ACROSS MUCH OF THE CWA MAINLY BETWEEN 4PM-9PM...BUT LIKELY GRADUALLY LOSING STEAM AS IT DOES SO. ALTHOUGH LOW LEVEL SHEAR WILL BE STRONG...THUS MEANING THAT A BRIEF TORNADO THREAT IS NON- ZERO...EXPECT SYNOPTIC FORCING TO BE STRONG ENOUGH TO FORCE A LINEAR MODE FAIRLY QUICKLY...WITH THE MAIN THREAT BEING WINDS GUSTS TO AT LEAST 60 MPH...AND MAYBE SOME MARGINALLY SEVERE HAIL TO AROUND QUARTER SIZE. ALTHOUGH THE SPC SLIGHT RISK AREA COVERS NEARLY THE ENTIRE CWA...WILL BE FOCUSING THE LOCAL HAZARDOUS WEATHER OUTLOOK MAINLY ON THE SOUTHWEST HALF OF THE CWA...OR ROUGHLY SOUTHWEST OF A LOUP CITY-BELOIT LINE WHERE INSTABILITY SHOULD BE MAXIMIZED BEFORE IT DROPS OFF FARTHER EAST AS NIGHT FALLS. TURNING BRIEFLY TO OTHER ELEMENTS TODAY...HIGH TEMPERATURES WILL BE QUITE TRICKY AND OBVIOUSLY VERY DEPENDENT ON HOW MUCH PRECIP IS FALLING AND WHETHER ANY CLEARING TAKES PLACE IN THE SOUTHWEST...BUT BASED ON A VARIED BLEND OF SHORT TERM MODELS/GUIDANCE HAVE A RANGE FROM ONLY MID-UPPER 50S NORTH TO MID- UPPER 60S SOUTHWEST...WHICH IS A BIT COOLER THAN A STRAIGHT MET/MAV GUIDANCE BLEND AND COUNTS ON LOW CLOUDS HOLDING FIRM ACROSS MOST OF THE AREA. WIND-WISE TODAY...ALTHOUGH CERTAINLY QUITE BREEZY WITH SUSTAINED SOUTH-SOUTHEAST SPEEDS AVERAGING 20-25 MPH WITH GUSTS TO AROUND 30 MPH AHEAD OF THE APPROACHING COLD FRONT...NOT EXPECTING SUSTAINED SPEEDS TO BREACH ADVISORY CRITERIA OF 30+ MPH. TURNING TO THE TONIGHT PERIOD/7PM-7AM/...THE MAIN FOCUS IS ON HOW QUICKLY CONVECTION VACATES THE AREA...AND HOW STRONG WEST- NORTHWEST WINDS BECOME. ON THE BIG PICTURE...THERE IS GOOD AGREEMENT THAT THE CENTER OF THE CLOSED MID LEVEL LOW WILL ONLY SLOWLY MIGRATE FROM FAR NORTH CENTRAL NEB TO NEAR SIOUX FALLS...WHILE THE ATTENDANT SURFACE LOW FOLLOWS A SIMILAR PATH AND MAINTAINS A SIMILAR CENTRAL PRESSURE AROUND 1003MB. IN THE STOUT COLD AIR ADVECTION REGIME BEHIND THE DEPARTING LOW...AND IN AN ENHANCED PRESSURE GRADIENT BETWEEN THE SURFACE LOW AND AN EXPANSIVE HIGH NOSING INTO THE REGION FROM THE NORTHERN ROCKIES...ITS QUITE POSSIBLE THAT ESPECIALLY THE NORTHWEST HALF OF THE CWA MAY BE OVERALL-WINDIER TONIGHT THAN THEY ARE DURING THE DAY TODAY...EXCEPT THIS TIME OUT OF THE WEST-NORTHWEST BEHIND THE QUICKLY PASSING COLD FRONT...WHICH IS SLATED TO CRUISE ACROSS THE CWA GENERALLY BETWEEN 5-11PM. ALTHOUGH ITS NOT OUT OF THE QUESTION THAT THE LATEST SUITE OF MODELS/GUIDANCE ARE UNDER-DOING WIND SPEEDS A BIT...AT LEAST FOR NOW EXPECT SUSTAINED SPEEDS TO ONLY AVERAGE IN THE 20-25 MPH RANGE WITH GUSTS OF 30-35 MPH...AND THUS FALLING AT LEAST SLIGHTLY SHORT OF ADVISORY CRITERIA. NEIGHBORING OFFICES TO THE WEST HAVE ISSUED WIND HEADLINES FOR PORTIONS OF TODAY/TONIGHT...BUT AT THIS POINT JUST DON/T SEE THE LOCAL AREA BEING QUITE WINDY ENOUGH TO JUSTIFY AN ADVISORY...ALTHOUGH OF COURSE LATER SHIFTS WILL HAVE TO RE-EVALUATE THIS. OTHERWISE...IN TERMS OF PRECIP TRENDS...HAVE SLIGHTLY SPED UP THE DEPARTURE OF SHOWERS/STORMS...WITH MUCH OF THE WESTERN 1/2 OF THE CWA LIKELY DRIED OUT BY AROUND SUNSET...WHILE LIKELY POPS CONTINUE IN EASTERN COUNTIES THROUGH 02Z/9PM BEFORE QUICKLY DIMINISHING AND ENDING BY MIDNIGHT. ITS POSSIBLE THAT STORMS COULD CARRY AT LEAST A MARGINAL SEVERE THREAT UNTIL THEY DEPART EASTERN AREAS...BUT WOULD EXPECT THE MAIN THREAT TO DIMINISH POST-SUNSET. ALTHOUGH THE MAIN AREA OF PRECIP WILL VACATE THE AREA THIS EVENING...DID INTRODUCE A SLIGHT CHANCE OF LIGHT RAIN TO FAR NORTHERN ZONES THROUGH THE LATE EVENING/OVERNIGHT HOURS TO ACCOUNT FOR PRECIPITATION POSSIBLY BARELY BRUSHING THE CWA ON THE SOUTH-END OF THE WRAP-AROUND SHIELD. THE VAST MAJORITY OF THIS SHOULD FOCUS ACROSS FAR NORTHERN NEB HOWEVER. MADE LITTLE CHANGE TO OVERNIGHT LOWS...WITH MOST OF THE CWA BOTTOMING OUT IN THE 39-42 RANGE BY SUNRISE TUESDAY...ALTHOUGH ESPECIALLY THE NORTHWEST HALF OF THE AREA MAY BE HELD UP A BIT BY PLENTY OF LOW STRATUS WRAPPING BACK SOUTHWARD INTO THE AREA. THOSE VENTURING OUT LATE TONIGHT/EARLY TUESDAY WILL DEFINITELY NOTICE A BITE TO THE AIR...WITH WIND CHILL READINGS WELL DOWN INTO THE 30S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 445 AM CDT MON OCT 14 2013 PRIMARY CONCERNS WILL BE WINDY CONDITIONS ON TUESDAY AND LOW TEMPERATURES WITH FROST/FREEZE CHANCES ON WEDNESDAY AND THURSDAY MORNING. BUSY PATTERN STARTING OUT TUESDAY MORNING AS 500MB CLOSED LOW IS EXPECTED TO BE NEAR THE SDAK/MN BORDER WITH THE SYSTEM STACKED AS SURFACE LOW SHOULD BE JUST A TAD SOUTHEAST OF THE UPPER LOW POSITION. IN ADDITION TO THE UPPER LOW...TROUGHINESS IS EXPECTED TO EXTEND WESTWARD TOWARD THE CENTRAL ROCKIES. AS NOTED ABOVE...EXPECT WINDY CONDITIONS DURING THE DAYTIME TUESDAY AS WE SIT IN BETWEEN A WOUND UP SURFACE LOW NEAR THE MN/IA BORDER AND A STRONG HIGH PRESSURE BUILDING INTO CENTRAL WYOMING. THIS WILL RESULT IN A 20MB PRESSURE GRADIENT ACROSS NEBRASKA. SHOULD SEE SUSTAINED 25 MPH WINDS AT LEAST AND MAY BE APPROACHING ADVISORY CRITERIA ESPECIALLY IN THE NORTHERN HALF OF THE CWA FROM MID MORNING TO MID AFTERNOON. SOME LIGHT RAIN ALSO POSSIBLE ON TUESDAY IN THE NORTHERN QUARTER OF THE CWA WRAPPING AROUND THE LOW PRESSURE. IF WE DO GET ANY IT SHOULD NOT AMOUNT TO MUCH MORE THAN ONE OR TWO HUNDREDTHS. BY WEDNESDAY MORNING THE SURFACE LOW WILL HAVE MOVED INTO THE GREAT LAKES REGION WITH THE SURFACE HIGH BUILDING INTO OUR AREA. THIS WILL BRING LIGHTER WINDS AND ALSO EXPECTING SKIES TO CLEAR OUT...SO WITH DEWPOINTS IN THE UPPER 20S TO NEAR 30...MUCH OF THE CWA STANDS A DECENT CHANCE OF SEEING FROST WED MORNING. ON THURSDAY ANOTHER MID LEVEL WAVE WILL SLIDE ACROSS DRAGGING A COLD FRONT THROUGH THE CWA. DOESN`T APPEAR TO BE MUCH MOISTURE WITH THIS SYSTEM AND WILL KEEP FORECAST DRY. FRIDAY IS A LITTLE MORE INTERESTING AS A DEEP UPPER LOW SWINGS ACROSS CANADA AND THE NORTHERN PART OF THE U.S. THE EC MODELS BRINGS DOWN MUCH COLDER AIR THAN THE OPERATIONAL GFS. IT ALSO BRINGS A STRONG MID LEVEL WAVE DOWN THE BACKSIDE OF THE LOW ON FRIDAY AND GENERATES SOME MODERATE QPF WITH IT. THE GFS NOT SHOWING THIS AND THE GEM IS ALSO UNDERPLAYING THIS FEATURE. CHECKING THE ALL BLEND POPS...THEY ARE ONLY IN THE 15 TO 20 PERCENT RANGE FOR THE DAYTIME FRIDAY. BACK TO THE EC...IF ONE WERE TO ONLY LOOK AT 1000-500 MB THICKNESSES...THERE MAY BE CAUSE FOR CONCERN AS THE EC IS SHOWING THICKNESSES CONDUCIVE FOR SNOW. HOWEVER...A CLOSER EXAMINATION OF THE FORECAST SOUNDINGS FROM THE EC SHOWS SURFACE TEMPS IN THE UPPER 30S FRIDAY MORNING. ALSO THE GROUND SHOULD BE FAIRLY WARM SINCE HIGHS ON WED AND THURSDAY WILL BE NEAR 60. SO IF THE EC DOES VERIFY WITH THE MID LEVEL WAVE...WOULD EXPECT ANY PRECIP THAT OCCURS TO BE MORE OF A COLD RAIN. OF COURSE THIS WILL NEED TO BE MONITORED OVER THE NEXT FEW DAYS. && .AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z TUESDAY MORNING) ISSUED AT 606 AM CDT MON OCT 14 2013 A FAIRLY ACTIVE 24 HOURS OF WEATHER CONTINUES AT KGRI...WITH VARIOUS CONCERNS INCLUDING LOW LEVEL WIND SHEAR...SEVERAL HOURS OF PREVAILING MVFR CEILINGS WITH IFR NOT OUT OF THE QUESTION...GOOD CHANCES FOR PASSING SHOWERS/THUNDERSTORMS...AND FINALLY A PRONOUNCED WIND SHIFT BEHIND A COLD FRONT THIS EVENING. GOING ROUGHLY IN CHRONOLOGICAL ORDER WITH THESE ISSUES...HAVE EXTENDED A MENTION OF LOW LEVEL WIND SHEAR THROUGH 18Z...AS A STRONG LOW LEVEL JET STREAM WILL MAINTAIN AT LEAST A 30-40KT WIND VECTOR DIFFERENCE BETWEEN THE SURFACE AND ROUGHLY 1800 FT AGL...THANKS TO WINDS AT THE TOP OF THIS LAYER AVERAGING AROUND 50KT FROM THE SOUTH. SECONDLY...STRONG MOISTURE ADVECTION/LIFT SHOULD KEEP MVFR CEILINGS AROUND ALL DAY INTO THIS EVENING. HAVE KEPT OUT ANY IFR CEILING FOR NOW...BUT SOME MODEL GUIDANCE SUGGESTS IT IS ALSO POSSIBLE. THROUGH AROUND 03Z THIS EVENING...SCATTERED TO NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS WILL CONTINUE...AND AM ADVERTISING EITHER VCSH/VCTS OR OUTRIGHT PREVAILING -SHRA THROUGH THE FIRST 15 HOURS OF THE PERIOD...BEFORE THERE IS FAIRLY HIGH CONFIDENCE THAT ANY RISK OF PRECIP ENDS THIS EVENING. SURFACE WINDS WILL REMAIN FAIRLY CONSISTENT FROM THE SOUTHEAST AT SUSTAINED SPEEDS 15-20KT WITH GUST POTENTIAL TO AT LEAST 26KT THROUGH THE DAYTIME HOURS...BEFORE AN ABRUPT SWITCH TO WESTERLY WINDS OCCURS AROUND SUNSET AS THE COLD FRONT PASSES...WITH GUST POTENTIAL CONTINUING TO AT LEAST 26KT WELL INTO THE NIGHT. WILL ALSO RAISE CEILING BACK INTO LOW-END VFR TERRITORY BEHIND THIS FRONT...AND SKIES COULD OUTRIGHT CLEAR FOR A TIME...VARYING DEGREES OF LOW LEVEL STRATUS COULD STICK AROUND THROUGH THE NIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
445 AM CDT MON OCT 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 445 AM CDT MON OCT 14 2013 AN ACTIVE 24 HOURS WITH QUITE HIGH MEASURABLE RAIN CHANCES IS ALREADY UNDERWAY ACROSS THE CWA...WITH PLENTY OF FORECAST CHALLENGES RANGING FROM TRYING TO REFINE SHORT-TERM POPS...ASSESSING THE MAGNITUDE OF A POSSIBLE SEVERE WEATHER RISK THIS AFTERNOON-EARLY EVENING...DETERMINING THE EFFECTS OF WIDESPREAD CLOUD COVER/PRECIP ON HIGH TEMPS...AND ALSO TRYING TO DETERMINE HOW CLOSE ESPECIALLY THE NORTHWESTERN CWA MAY COME TO AT LEAST BRIEFLY FLIRTING WITH WIND ADVISORY CRITERIA TONIGHT IN THE WAKE OF THE PASSING LOW. 08Z OBJECTIVE SURFACE ANALYSIS REVEALS A GRADUALLY-TIGHTENING PRESSURE GRADIENT...BETWEEN A ROUGHLY 1031 MILLIBAR HIGH OVER THE GREAT LAKES...AND A 1006 LOW OVER NORTHEAST CO. AS A RESULT...SUSTAINED SOUTHEAST WINDS ACROSS MOST OF THE CWA AT THIS HOUR ARE AVERAGING AT LEAST 10-15 MPH WITH HIGHER GUSTS TO AROUND 20 MPH...ESPECIALLY IN THE WEST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A VIGOROUS MID/UPPER LEVEL TROUGH PLOWING ACROSS THE ROCKIES...WITH ITS 500MB VORT MAX CURRENTLY SWINGING OVER THE 4-CORNERS AREA. UPPER LEVEL FLOW HAS BECOME INCREASINGLY DIFFLUENT OVER THE CENTRAL PLAINS AHEAD OF A 100+KT JET STREAK APPROACHING FROM SOUTHERN CO...AND FARTHER DOWN A 40-50KT SOUTHERLY LOW LEVEL JET IS EVIDENT AT 850MB...RIGHT OVER THE HEART OF CENTRAL/WESTERN NEB AND KS. MUCH AS EXPECTED FOR DAYS NOW...STOUT LOW-MID LEVEL MOISTURE ADVECTION ESPECIALLY EVIDENT IN THE 850-700MB LAYER HAS RESULTED IN A GRADUAL INCREASE IN SHOWER/THUNDERSTORM ACTIVITY WITHIN THE CWA DURING THE NIGHT. OF COURSE...ITS NOT RAINING EVERYWHERE AT ONCE...AND EARLIER ON MOST OF THE PRECIP WAS FOCUSED IN NORTHWESTERN COUNTIES...BUT OVER THE PAST FEW HOURS THE MAIN FOCUS HAS TRANSITIONED TO ROUGHLY THE EASTERN 1/2 OF THE CWA...WITH MUCH OF THE WEST IN AT LEAST A SHORT TERM LULL. ALTHOUGH ITS QUITE POSSIBLE THAT A FEW OF THE STRONGER STORMS EARLY THIS MORNING HAVE PRODUCED/COULD PRODUCE VERY SMALL HAIL...NOT EXPECTING ANY SEVERE STORMS GIVEN MUCAPE IN THE 850-700MB LAYER ONLY AVERAGING A FEW HUNDRED J/KG PER LATEST RAP- BASED MESOANALYSIS. NOT SURPRISINGLY...TEMPS HAVE BEEN FAIRLY STEADY EARLY THIS MORNING UNDER WHAT HAS BECOME WIDESPREAD LOW CLOUD COVER AND SLOWLY-INCREASING DEWPOINTS...WITH MOST ALL PLACES CURRENTLY SOMEWHERE IN THE 50S. FOCUSING ON THE DAYTIME HOURS TODAY THROUGH 00Z/7PM...TOOK A BEST STAB AT 3-HOURLY POP TRENDS...BUT THE BOTTOM LINE IS THAT THE ENTIRE CWA IS SPORTING AN 80-90 PERCENT CHANCE OF MEASURABLE RAIN THROUGH SUNSET...ITS JUST A MATTER OF WHEN IT FALLS AND HOW MUCH FALLS. IN THE BIG PICTURE...THE PRIMARY 500MB VORT MAX ASSOCIATED WITH THE INCOMING TROUGH IS SCHEDULED TO REACH THE NEB PANHANDLE BY MID-DAY AS IT DEEPENS AND SWINGS NORTHEAST IN A NEGATIVELY TILTED FASHION...AND THEN REACHING FAR NORTH CENTRAL NEB BY AROUND SUNSET. IN SUIT...THE ASSOCIATED SURFACE LOW CURRENTLY CENTERED IN NORTHEAST CO IS PROGGED TO SHIFT NORTHEAST AS WELL...BUT SLIGHTLY SOUTHEAST OF THE MID LEVEL LOW TRACK...MEANING THAT IT GENERALLY SKIRTS JUST ALONG THE FAR WEST-CENTRAL/NORTHWEST EDGES OF THE CWA AS IT TRACKS NORTHEAST INTO NORTH CENTRAL NEB BY SUNSET WITH A CENTRAL PRESSURE AROUND 1003MB. MEANWHILE...A STOUT 50+KT LOW LEVEL JET WILL PERSIST OVER THE CWA PRETTY MUCH ALL DAY...WHICH IN TANDEM WITH CONTINUED LOW-MID LEVEL THETA-E ADVECTION SHOULD PROMOTE RATHER WIDESPREAD SHOWERS AND AT LEAST ISOLATED TO SCATTERED EMBEDDED THUNDERSTORMS THROUGH MUCH OF THE DAY. ITS YET TO BE SEEN WHETHER THIS WIDESPREAD PRECIPITATION MAINLY STAYS FOCUSED ACROSS THE EASTERN HALF OF THE CWA AS CURRENTLY HAPPENING...OR EVENTUALLY ALSO DEVELOPS OVER...OR MOVES INTO WESTERN AREAS AS WELL. MODELS VARY...WITH SOME ENDING THE LULL OVER THE WEST BY MID-MORNING...WHILE OTHERS SUCH AS THE LATEST HRRR CONTINUE TO FOCUS ON EASTERN AREAS AT LEAST THROUGH MID-DAY. AT ANY RATE...WOULD BE QUITE SURPRISED IF ANY OF THE CWA GOT THROUGH THE ENTIRE DAY WITHOUT MEASURABLE RAIN...AS MANY EASTERN AREAS COULD EASILY RECEIVE 0.50-0.75 INCH OR MORE THROUGH SUNSET. TURNING TO THE AFTERNOON HOURS...AS HAS ALSO BEEN ADVERTISED FOR A FEW DAYS NOW WE ARE FACING A CONDITIONAL SEVERE WEATHER THREAT...AS SPC HAS THE MAJORITY OF THE CWA IN A DAY 1 SLIGHT RISK AREA. THE MILLION DOLLAR QUESTION HERE IS...HOW MUCH CLEARING WILL TAKE PLACE JUST WEST OF...AND POSSIBLY INTO THE FAR SOUTHWESTERN PORTIONS OF THE CWA THIS AFTERNOON UNDER THE INVADING MID LEVEL DRY SLOT AND JUST AHEAD OF THE INVADING COLD FRONT/DRYLINE COMBO...TO PROMOTE SUFFICIENT DESTABILIZATION FOR SEVERE STORMS. FOLLOWING THE LEAD OF THE LATEST RAP...THE VAST MAJORITY OF THE CWA WILL REMAIN LOCKED UNDER LOW CLOUDS AND SCATTERED TO WIDESPREAD ELEVATED PRECIP THROUGH NEARLY THE ENTIRE DAY...WITH LIKELY NOTHING MORE THAN A HIT AND MISS THREAT OF SMALL HAIL POSSIBLY UP TO AROUND DIME SIZE. HOWEVER...BY MID-LATE AFTERNOON...THE RAP BRINGS A NARROW NORTH-SOUTH CORRIDOR OF LOW-LEVEL CAPE POTENTIALLY INTO THE 1000-1500 J/KG RANGE INTO MAINLY THE WESTERN 1/4 OF THE CWA. AS A RESULT...AND AS DEPICTED FAIRLY WELL BY THE 00Z RUNS OF THE 4KM WRF-NMM AND ARW AND ALSO THE LATEST HRRR...A LINE OF FAST MOVING STRONG TO POTENTIALLY SEVERE STORMS COULD SWEEP FROM WEST- EAST ACROSS MUCH OF THE CWA MAINLY BETWEEN 4PM-9PM...BUT LIKELY GRADUALLY LOSING STEAM AS IT DOES SO. ALTHOUGH LOW LEVEL SHEAR WILL BE STRONG...THUS MEANING THAT A BRIEF TORNADO THREAT IS NON- ZERO...EXPECT SYNOPTIC FORCING TO BE STRONG ENOUGH TO FORCE A LINEAR MODE FAIRLY QUICKLY...WITH THE MAIN THREAT BEING WINDS GUSTS TO AT LEAST 60 MPH...AND MAYBE SOME MARGINALLY SEVERE HAIL TO AROUND QUARTER SIZE. ALTHOUGH THE SPC SLIGHT RISK AREA COVERS NEARLY THE ENTIRE CWA...WILL BE FOCUSING THE LOCAL HAZARDOUS WEATHER OUTLOOK MAINLY ON THE SOUTHWEST HALF OF THE CWA...OR ROUGHLY SOUTHWEST OF A LOUP CITY-BELOIT LINE WHERE INSTABILITY SHOULD BE MAXIMIZED BEFORE IT DROPS OFF FARTHER EAST AS NIGHT FALLS. TURNING BRIEFLY TO OTHER ELEMENTS TODAY...HIGH TEMPERATURES WILL BE QUITE TRICKY AND OBVIOUSLY VERY DEPENDENT ON HOW MUCH PRECIP IS FALLING AND WHETHER ANY CLEARING TAKES PLACE IN THE SOUTHWEST...BUT BASED ON A VARIED BLEND OF SHORT TERM MODELS/GUIDANCE HAVE A RANGE FROM ONLY MID-UPPER 50S NORTH TO MID- UPPER 60S SOUTHWEST...WHICH IS A BIT COOLER THAN A STRAIGHT MET/MAV GUIDANCE BLEND AND COUNTS ON LOW CLOUDS HOLDING FIRM ACROSS MOST OF THE AREA. WIND-WISE TODAY...ALTHOUGH CERTAINLY QUITE BREEZY WITH SUSTAINED SOUTH-SOUTHEAST SPEEDS AVERAGING 20-25 MPH WITH GUSTS TO AROUND 30 MPH AHEAD OF THE APPROACHING COLD FRONT...NOT EXPECTING SUSTAINED SPEEDS TO BREACH ADVISORY CRITERIA OF 30+ MPH. TURNING TO THE TONIGHT PERIOD/7PM-7AM/...THE MAIN FOCUS IS ON HOW QUICKLY CONVECTION VACATES THE AREA...AND HOW STRONG WEST- NORTHWEST WINDS BECOME. ON THE BIG PICTURE...THERE IS GOOD AGREEMENT THAT THE CENTER OF THE CLOSED MID LEVEL LOW WILL ONLY SLOWLY MIGRATE FROM FAR NORTH CENTRAL NEB TO NEAR SIOUX FALLS...WHILE THE ATTENDANT SURFACE LOW FOLLOWS A SIMILAR PATH AND MAINTAINS A SIMILAR CENTRAL PRESSURE AROUND 1003MB. IN THE STOUT COLD AIR ADVECTION REGIME BEHIND THE DEPARTING LOW...AND IN AN ENHANCED PRESSURE GRADIENT BETWEEN THE SURFACE LOW AND AN EXPANSIVE HIGH NOSING INTO THE REGION FROM THE NORTHERN ROCKIES...ITS QUITE POSSIBLE THAT ESPECIALLY THE NORTHWEST HALF OF THE CWA MAY BE OVERALL-WINDIER TONIGHT THAN THEY ARE DURING THE DAY TODAY...EXCEPT THIS TIME OUT OF THE WEST-NORTHWEST BEHIND THE QUICKLY PASSING COLD FRONT...WHICH IS SLATED TO CRUISE ACROSS THE CWA GENERALLY BETWEEN 5-11PM. ALTHOUGH ITS NOT OUT OF THE QUESTION THAT THE LATEST SUITE OF MODELS/GUIDANCE ARE UNDER-DOING WIND SPEEDS A BIT...AT LEAST FOR NOW EXPECT SUSTAINED SPEEDS TO ONLY AVERAGE IN THE 20-25 MPH RANGE WITH GUSTS OF 30-35 MPH...AND THUS FALLING AT LEAST SLIGHTLY SHORT OF ADVISORY CRITERIA. NEIGHBORING OFFICES TO THE WEST HAVE ISSUED WIND HEADLINES FOR PORTIONS OF TODAY/TONIGHT...BUT AT THIS POINT JUST DON/T SEE THE LOCAL AREA BEING QUITE WINDY ENOUGH TO JUSTIFY AN ADVISORY...ALTHOUGH OF COURSE LATER SHIFTS WILL HAVE TO RE-EVALUATE THIS. OTHERWISE...IN TERMS OF PRECIP TRENDS...HAVE SLIGHTLY SPED UP THE DEPARTURE OF SHOWERS/STORMS...WITH MUCH OF THE WESTERN 1/2 OF THE CWA LIKELY DRIED OUT BY AROUND SUNSET...WHILE LIKELY POPS CONTINUE IN EASTERN COUNTIES THROUGH 02Z/9PM BEFORE QUICKLY DIMINISHING AND ENDING BY MIDNIGHT. ITS POSSIBLE THAT STORMS COULD CARRY AT LEAST A MARGINAL SEVERE THREAT UNTIL THEY DEPART EASTERN AREAS...BUT WOULD EXPECT THE MAIN THREAT TO DIMINISH POST-SUNSET. ALTHOUGH THE MAIN AREA OF PRECIP WILL VACATE THE AREA THIS EVENING...DID INTRODUCE A SLIGHT CHANCE OF LIGHT RAIN TO FAR NORTHERN ZONES THROUGH THE LATE EVENING/OVERNIGHT HOURS TO ACCOUNT FOR PRECIPITATION POSSIBLY BARELY BRUSHING THE CWA ON THE SOUTH-END OF THE WRAP-AROUND SHIELD. THE VAST MAJORITY OF THIS SHOULD FOCUS ACROSS FAR NORTHERN NEB HOWEVER. MADE LITTLE CHANGE TO OVERNIGHT LOWS...WITH MOST OF THE CWA BOTTOMING OUT IN THE 39-42 RANGE BY SUNRISE TUESDAY...ALTHOUGH ESPECIALLY THE NORTHWEST HALF OF THE AREA MAY BE HELD UP A BIT BY PLENTY OF LOW STRATUS WRAPPING BACK SOUTHWARD INTO THE AREA. THOSE VENTURING OUT LATE TONIGHT/EARLY TUESDAY WILL DEFINITELY NOTICE A BITE TO THE AIR...WITH WIND CHILL READINGS WELL DOWN INTO THE 30S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 445 AM CDT MON OCT 14 2013 PRIMARY CONCERNS WILL BE WINDY CONDITIONS ON TUESDAY AND LOW TEMPERATURES WITH FROST/FREEZE CHANCES ON WEDNESDAY AND THURSDAY MORNING. BUSY PATTERN STARTING OUT TUESDAY MORNING AS 500MB CLOSED LOW IS EXPECTED TO BE NEAR THE SDAK/MN BORDER WITH THE SYSTEM STACKED AS SURFACE LOW SHOULD BE JUST A TAD SOUTHEAST OF THE UPPER LOW POSITION. IN ADDITION TO THE UPPER LOW...TROUGHINESS IS EXPECTED TO EXTEND WESTWARD TOWARD THE CENTRAL ROCKIES. AS NOTED ABOVE...EXPECT WINDY CONDITIONS DURING THE DAYTIME TUESDAY AS WE SIT IN BETWEEN A WOUND UP SURFACE LOW NEAR THE MN/IA BORDER AND A STRONG HIGH PRESSURE BUILDING INTO CENTRAL WYOMING. THIS WILL RESULT IN A 20MB PRESSURE GRADIENT ACROSS NEBRASKA. SHOULD SEE SUSTAINED 25 MPH WINDS AT LEAST AND MAY BE APPROACHING ADVISORY CRITERIA ESPECIALLY IN THE NORTHERN HALF OF THE CWA FROM MID MORNING TO MID AFTERNOON. SOME LIGHT RAIN ALSO POSSIBLE ON TUESDAY IN THE NORTHERN QUARTER OF THE CWA WRAPPING AROUND THE LOW PRESSURE. IF WE DO GET ANY IT SHOULD NOT AMOUNT TO MUCH MORE THAN ONE OR TWO HUNDREDTHS. BY WEDNESDAY MORNING THE SURFACE LOW WILL HAVE MOVED INTO THE GREAT LAKES REGION WITH THE SURFACE HIGH BUILDING INTO OUR AREA. THIS WILL BRING LIGHTER WINDS AND ALSO EXPECTING SKIES TO CLEAR OUT...SO WITH DEWPOINTS IN THE UPPER 20S TO NEAR 30...MUCH OF THE CWA STANDS A DECENT CHANCE OF SEEING FROST WED MORNING. ON THURSDAY ANOTHER MID LEVEL WAVE WILL SLIDE ACROSS DRAGGING A COLD FRONT THROUGH THE CWA. DOESN`T APPEAR TO BE MUCH MOISTURE WITH THIS SYSTEM AND WILL KEEP FORECAST DRY. FRIDAY IS A LITTLE MORE INTERESTING AS A DEEP UPPER LOW SWINGS ACROSS CANADA AND THE NORTHERN PART OF THE U.S. THE EC MODELS BRINGS DOWN MUCH COLDER AIR THAN THE OPERATIONAL GFS. IT ALSO BRINGS A STRONG MID LEVEL WAVE DOWN THE BACKSIDE OF THE LOW ON FRIDAY AND GENERATES SOME MODERATE QPF WITH IT. THE GFS NOT SHOWING THIS AND THE GEM IS ALSO UNDERPLAYING THIS FEATURE. CHECKING THE ALL BLEND POPS...THEY ARE ONLY IN THE 15 TO 20 PERCENT RANGE FOR THE DAYTIME FRIDAY. BACK TO THE EC...IF ONE WERE TO ONLY LOOK AT 1000-500 MB THICKNESSES...THERE MAY BE CAUSE FOR CONCERN AS THE EC IS SHOWING THICKNESSES CONDUCIVE FOR SNOW. HOWEVER...A CLOSER EXAMINATION OF THE FORECAST SOUNDINGS FROM THE EC SHOWS SURFACE TEMPS IN THE UPPER 30S FRIDAY MORNING. ALSO THE GROUND SHOULD BE FAIRLY WARM SINCE HIGHS ON WED AND THURSDAY WILL BE NEAR 60. SO IF THE EC DOES VERIFY WITH THE MID LEVEL WAVE...WOULD EXPECT ANY PRECIP THAT OCCURS TO BE MORE OF A COLD RAIN. OF COURSE THIS WILL NEED TO BE MONITORED OVER THE NEXT FEW DAYS. && .AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z MONDAY NIGHT) ISSUED AT 100 AM CDT MON OCT 14 2013 A FAIRLY ACTIVE 24 HOURS OF WEATHER AWAITS THE TERMINAL...WITH VARIOUS CONCERNS INCLUDING LOW LEVEL WIND SHEAR...SEVERAL HOURS OF PREVAILING MVFR CEILINGS WITH IFR NOT OUT OF THE QUESTION...GOOD CHANCES FOR SEVERAL ROUNDS OF PASSING SHOWERS/THUNDERSTORMS...AND FINALLY A PRONOUNCED WIND SHIFT BEHIND A COLD FRONT MONDAY EVENING. GOING ROUGHLY IN CHRONOLOGICAL ORDER WITH THESE ISSUES...HAVE MAINTAINED A MENTION OF LOW LEVEL WIND SHEAR THROUGH 15Z...AS A STRONG LOW LEVEL JET STREAM WILL MAINTAIN AT LEAST A 30-40KT WIND VECTOR DIFFERENCE BETWEEN THE SURFACE AND ROUGHLY 1800 FT AGL...THANKS TO WINDS AT THE TOP OF THIS LAYER AVERAGING AROUND 50KT FROM THE SOUTH. SECONDLY...STRONG MOISTURE ADVECTION WILL USHER IN HIGH-END MVFR CEILING WITHIN THE NEXT FEW HOURS...WITH THIS CEILING LIKELY LOWERING INTO LOW-END MVFR THRESHOLDS FOR MUCH OF THE DAYTIME HOURS. HAVE KEPT OUT ANY IFR CEILING FOR NOW...BUT SOME MODEL GUIDANCE SUGGESTS IT IS ALSO POSSIBLE. AS TIME GOES BY EARLY THIS MORNING INTO THE DAYTIME HOURS...SCATTERED TO NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS WILL BECOME INCREASINGLY LIKELY...AND AM ADVERTISING EITHER VCSH/VCTS OR OUTRIGHT PREVAILING -SHRA THROUGH THE FIRST 21 HOURS OF THE PERIOD...BEFORE THERE IS FAIRLY HIGH CONFIDENCE THAT ANY RISK OF PRECIP ENDS MONDAY EVENING. SURFACE WINDS WILL REMAIN FAIRLY CONSISTENT FROM THE SOUTHEAST AT SUSTAINED SPEEDS 15-20KT WITH GUST POTENTIAL TO AT LEAST 26KT THROUGH THE DAYTIME HOURS...BEFORE AN ABRUPT SWITCH TO WESTERLY WINDS OCCURS AROUND SUNSET AS THE COLD FRONT PASSES...WITH GUST POTENTIAL CONTINUING TO AT LEAST 26KT WELL INTO THE NIGHT. WILL ALSO RAISE CEILING BACK INTO LOW-END VFR TERRITORY BEHIND THIS FRONT...BUT PLENTY OF PASSING LOW-LEVEL STRATUS COULD STICK AROUND THROUGH THE NIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
355 AM CDT MON OCT 14 2013 .DISCUSSION... MAIN FORECAST CHALLENGE IS TIMING THE RAIN TODAY THROUGH TUESDAY...AND DETERMINING RAINFALL AMOUNTS. AT 08Z...SHOWERS WITH A FEW THUNDERSTORMS WERE MOVING THROUGH PARTS OF NEBRASKA...THEN EXTENDED SOUTHWEST THROUGH COLORADO AND INTO NORTHERN NEW MEXICO. THIS AREA OF PRECIPITATION WAS IN RESPONSE TO A DEEP UPPER LOW SPINNING OVER UTAH PER WATER VAPOR IMAGERY. ASSOCIATED WITH THE LOW WAS AN IMPRESSIVE JET MAX OF AROUND 145 KNOTS AS INDICATED BY THE RAP MODEL ANALYSIS NEAR THE COLORADO- NEW MEXICO BORDER. NUMEROUS LIGHTNING STRIKES WERE NOTED WITHIN THIS PRECIPITATION AREA. THE SURFACE CYCLOGENESIS RESPONSE TO THE UPPER LOW WAS MAXIMIZED FROM SOUTHEAST WYOMING INTO SOUTHWEST SOUTH DAKOTA WHERE 3 HOURLY PRESSURE FALLS WERE 2-3MB. BASED ON THE 100 METER 500MB HEIGHT RISES ON THE BACK SIDE OF THE UPPER TROUGH...THE EXPECTED SCENARIO IS FOR THE UPPER LOW TO MOVE FROM UTAH INTO THE NEBRASKA PANHANDLE BY THIS AFTERNOON. THAT WILL PIVOT THE JET AXIS TO A MORE EAST-WEST ORIENTATION...POSITIONING IT ACROSS SOUTHEAST COLORADO-SOUTHERN KANSAS. EXPECT STRONG UPWARD FORCING DUE TO A COMBINATION OF: THE UPPER DIVERGENCE FROM THE LEFT FRONT EXIT REGION OF THE JET MAX...STRONG DPVA AHEAD OF THE UPPER LOW...ISENTROPIC LIFT IN THE WARM CONVEYER BELT REGION...AND CONTINUED SURFACE CYCLOGENESIS. ALL OF THIS POINTS TO A WELL-DEFINED EXTRATROPICAL CYCLONE PATTERN MOVING THROUGH THE PLAINS TODAY AND THIS EVENING...WITH A SURFACE COLD FRONT MOVING THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA TONIGHT. IN THESE SCENARIOS WE CAN PLAN ON SOMEWHAT HEAVY RAINS AHEAD OF THE LOW DURING THE DAY TODAY AND INTO THE EVENING...THEN THE DRY SLOT PUSHING INTO THE REGION OVERNIGHT TONIGHT. THEN AS THE UPPER LOW MOVES NORTHEAST OF THE REGION...SCATTERED SHOWERS SHOULD OCCUR ON THE BACK SIDE OF THE LOW IN THE DEFORMATION ZONE. RAINFALL AMOUNTS OF 2 INCHES WILL BE POSSIBLE NEAR THE SOUTH DAKOTA BORDER...WITH CLOSER TO 0.5 INCH NEAR THE MISSOURI BORDER...AND 1-1.5 INCHES NEAR I-80. THESE AMOUNTS ARE SUPPORTED BY FAIRLY GOOD MODEL AGREEMENT WITH THE OVERALL PATTERN AS WELL AS THE MODEL RAINFALL. THIS ACTIVE PATTERN SHOULD BE ACCOMPANIED BY A STRONG SOUTHERLY LOW LEVEL JET OF AROUND 60 KNOTS THIS AFTERNOON AND EVENING...THEN 40-45 KNOTS OUT OF THE NORTHWEST TUESDAY. THUNDERSTORMS THAT DEVELOP ON THE EASTERN EDGE OF THE DRY SLOT OVER SOUTH CENTRAL NEBRASKA THIS AFTERNOON/EVENING MAY BE QUITE STRONG AND COULD MOVE NORTHEAST INTO AREAS GENERALLY WEST AND SOUTH OF NORFOLK. BEHIND THE COLD FRONT...TEMPERATURES WILL BE ABOUT 10 DEGREES COLDER TUESDAY THAN TODAY WITH GUSTY NORTHWEST WINDS...CLOUDS...AND SCATTERED LIGHT SHOWERS ESPECIALLY IN NORTHEAST NEBRASKA. SURFACE HIGH PRESSURE MOVES IN WEDNESDAY WITH COOL/QUIET WEATHER. THE PATTERN OVER NORTH AMERICA SETTLES INTO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST WITH A BROAD LONGWAVE TROUGH FROM HUDSON BAY INTO THE SOUTHERN US...AND THIS KEEPS THE CENTRAL PLAINS IN A COOL NORTHWEST FLOW REGIME INTO NEXT WEEK. NIETFELD && .AVIATION... 06Z TAFS FOR KOFK...KOMA AND KLNK. CEILINGS WILL DECREASE AND PCPN WILL BE INCREASING IN COVERAGE OVERNIGHT...IN RESPONSE TO LOW PRESSURE SYSTEM APPROACHING FROM THE WEST. KOFK COULD SEE MVFR CONDITIONS PRIOR TO 12Z...WITH MVFR CONDITIONS MOVING IN BETWEEN 12Z AND 18Z AT KLNK AND KOMA. AT LEAST TEMPORARY IFR CONDITIONS POSSIBLE AFTER 18Z AT KOFK AND KLNK WITH TSRA. STRONG LOW LEVEL WINDS JUST ABOVE GROUND LEVEL WILL RESULT IN LOW LEVEL WIND SHEAR LATER TONIGHT INTO MONDAY MORNING. EXPECT IMPROVING CONDITIONS AFTER 06Z TUESDAY FOR KLNK AND KOMA BUT LOW CLOUDS SHOULD REMAIN IN THE KOFK AREA. MILLER && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
639 AM EDT MON OCT 14 2013 .SYNOPSIS... STALLED SURFACE FRONT NEAR OHIO RIVER TODAY. FRONT WASHES OUT TUESDAY. A STRONGER COLD FRONT MOVES THROUGH WEDNESDAY. POST FRONTAL DISTURBANCE RACES THROUGH LATE THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... WASHED OUT/STALLED SURFACE FRONT...REALLY MORE A WEAK PRESSURE TROUGH AT THIS POINT...RUNS FROM JUST WEST OF CKB TO JUST EAST OF HTS. DO HAVE SOME SOME MORE ENHANCED ECHOS SHOWING UP ALONG OR JUST WEST OF THIS BOUNDARY...AND ALSO IN NORTH CENTRAL WV. UPPED TO SCATTERED SHOWERS IN THESE AREA THROUGH THE EARLY MORNING. RAP SHOWS AN ELONGATED VORT LOBE MOVING ACROSS CWA THIS MORNING...SO KEEP SOME ISOLATED TO SCATTERED SHOWERS IN THE OHIO RIVER VALLEY TRANSITIONING MORE TO THE NORTHERN MOUNTAINS THIS AFTERNOON. LOW LEVEL MOISTURE STILL STRUGGLES TO CLEAR OUT...SO THINK PLENTY OF CLOUDS AROUND TODAY...EXCEPT VERY WESTERN CWA WHERE SATELLITE SHOWS CLEAR SKIES ALREADY DRIFTING IN. VORT LOBE AND ASSOCIATED POPS SHOULD BE MOVING OUT OF NORTHERN MOUNTAINS LATE AFTERNOON INTO EVENING...WITH A PRECIP FREE FORECAST BY LATE TONIGHT. COOLED HIGHS JUST A BIT TODAY WITH ABUNDANCE OF CLOUDS AND STAYED NEAR TO JUST ABOVE THE WARMER MET FOR LOWS TONIGHT. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AFTER A VERY STRANGE PATTERN OF LATE...WE FINALLY GET THE ATMOSPHERE MOVING AGAIN DURING THIS TUESDAY THROUGH THURSDAY NIGHT TIME PERIOD. SO SEVERAL FEATURES TO TIME. DRIER AIR AT 925 TO 850 MBS THAT IS OFF THE JERSEY COAST THIS PREDAWN SHOULD CONTINUE TO SNEAK BACK WSW AND REACH OUR MOUNTAINOUS COUNTIES FOR TUESDAY. SO EXPECTING LESS CLOUDS THERE DURING TUESDAY AFTERNOON...COMPARED TO SAY OUR OHIO COUNTIES. WARMEST DAY OF THE WEEK SHOULD BE TUESDAY. WITH THE 700 MB FLOW INCREASING IN THE LOWER OHIO VALLEY TUESDAY NIGHT. WAS JUST A BIT FASTER BRINGING BACK SOME CHANCE POPS FOR PREFRONTAL SHOWERS OVERNIGHT TUESDAY NIGHT IN THE WEST. ALSO...KEPT TEMPERATURES MILDER THAN MOST MOS GUIDANCE THERE. INITIAL TIMING OF FRONT IS THROUGH OUR OHIO RIVER VALLEY COUNTIES BY MIDDAY AND ACROSS THE MOUNTAINOUS COUNTIES BY SUNSET. SO...THE ONLY CHANGE WORTH MENTIONING WAS A BIT FASTER LOWERING POPS FROM WEST TO EAST. LEFT OUR FRONTAL POPS IN THE LIKELY RANGE...WAS NOT IMPRESSED ENOUGH TO RAISE TO CATEGORICAL. WITH THAT TIMING...LOWERED DAYTIME MAXIMUM TEMPERATURES A FEW DEGREES WEDNESDAY. WITH 850 TEMPERATURES DROPPING SOME 6 TO 8C OVERNIGHT WEDNESDAY NIGHT...HELD ONTO SOME POPS OVER THE MOUNTAIN COUNTIES...AS WE SQUEEZE OUT THE LOW LEVEL MOISTURE. YET...FURTHER WEST...AT LEAST PARTIAL CLEARING AS EVEN THE 850 MOISTURE THINS OUT. FOR THURSDAY AND THURSDAY NIGHT...THE MORE RECENT RUNS OF THE ECMWF HAVE COME AROUND TO WHAT THE GFS HAD BEEN ADVERTISING PREVIOUSLY. THE MID LEVEL DISTURBANCE RACES THROUGH HERE THURSDAY EVENING. MOISTURE INCREASES FOR THURSDAY AFTERNOON AND EVENING. SO HELD THURSDAY MORNING DRIER THAN OUR PREVIOUS FORECAST...BUT STILL INCREASED POPS THURSDAY AFTERNOON. THINK CLEARING WILL DEVELOP IN OUR WESTERN LOWLANDS THURSDAY NIGHT. WILL LOWER TEMPERATURES FOR DAWN FRIDAY...ESPECIALLY FOR SOUTHEAST OHIO...NORTHEAST KENTUCKY...AND SPILLING INTO A FEW RURAL AREAS OF WESTERN WEST VIRGINIA. HAVE SOME 35 TO 40 DEG TEMPERATURES THERE...WILL MENTION/ADD THE POSSIBILITY OF FROST IN A FEW SPOTS IN THE HAZARDOUS WEATHER POTENTIAL...BUT CURRENTLY DO NOT THINK IT WILL BE WIDESPREAD. && .LONG TERM /FRIDAY THROUGH SUNDAY/... MODELS ARE HAVING DISAGREEMENTS ON HANDLING A SOUTHERN STREAM SYSTEM ON THURSDAY IN THE SPLIT FLOW UPPER AIR PATTERN. ALL AGREE THAT A NORTHERN STREAM SHORT WAVE AND ASSOCIATED COLD FRONT WILL QUICKLY EXIT EARLY WEDNESDAY NIGHT...TAKING THE SHOWERS WITH IT. SOME COOLER AND DRIER AIR DOES FLOW IN BEHIND THIS FRONT WEDNESDAY NIGHT. THE BIG QUESTION BECOMES WHAT HAPPENS TO A CHUNK OF ENERGY LEFT OVER THE SOUTHERN ROCKIES AS IT GETS QUICKLY EJECTED BY ANOTHER NORTHERN STREAM SHORT WAVE DROPPING OUT OF WESTERN CANADA. WILL GO WITH PERSISTENCE IN OUR FORECAST AND ENOUGH MODEL CONSENSUS...USING LATEST GFS AND ECMWF MODELS AVAILABLE...WITH THIS SHORT WAVE LIFTING UP FAR ENOUGH WEST TO DRIVE SURFACE LOW PRESSURE NORTHEASTWARD FROM THE LOWER MISSISSIPPI VALLEY THRU THE MID ATLANTIC THURSDAY. THIS WILL BRING A SWATH OF RAIN ACROSS THE AREA THURSDAY...ESPECIALLY IN THE EAST. OTHERWISE...OUTSIDE A WEAK AND RATHER MOISTURE LIMITED COOL FRONT SATURDAY...HIGH PRESSURE WILL GENERALLY DOMINATE FRIDAY THRU THE WEEKEND. EXPECT TEMPERATURES TO BE A LITTLE BELOW NORMAL FOR THIS TIME OF YEAR...BUT NO SIGNIFICANT FREEZE/FROST OUTSIDE THE HIGHER ELEVATIONS OF THE WEST VIRGINIA IS EXPECTED THRU THE WEEKEND. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... CURRENT OBS SHOW IFR CIGS ACROSS MUCH OF FORECAST AREA. AFTER SUNRISE WILL START TO SEE DECK SLOWLY BEGIN LIFTING...HOWEVER EXPECT MVFR CIGS TO LINGER THROUGH MOST OF THE MORNING. WILL SEE CLOUDS LIFTING TO VFR THROUGH THE AFTERNOON...WITH SOME ISOLATED SHOWERS DRIFTING EAST...MAINLY ACROSS THE NORTHERN CWA. LOW ENOUGH POPS TO LEAVE ANY MENTION OF PRECIP OUT OF TAF FOR NOW. DRIER AIR ARRIVES ACROSS THE EAST OVERNIGHT...SO HIT THE FOG PRETTY HARD FOR MOUNTAIN VALLEYS. SHOULD CLOUDS CLEAR UP FARTHER WEST...COULD GET FOG ACROSS LOWLANDS TOO...HOWEVER THINK ENOUGH CLOUDS WILL HANG AROUND AND REDUCE CHANCES OF THAT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATIVE SCENARIOS: TIMING OF CIG CAT CHANGES ACROSS CWA MAY VARY. DENSITY AND TIMING OF FOG MAY VARY TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 CRW CONSISTENCY M M L L H H H M M M M H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M M 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 M H H H H H H H H H H H AFTER 12Z TUESDAY... IFR POSSIBLE IN CONVECTION WEDNESDAY WITH A COLD FRONT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/MZ NEAR TERM...MZ SHORT TERM...KTB LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
430 AM EDT MON OCT 14 2013 .SYNOPSIS... STALLED SURFACE FRONT NEAR OHIO RIVER TODAY. FRONT WASHES OUT TUESDAY. A STRONGER COLD FRONT MOVES THROUGH WEDNESDAY. POST FRONTAL DISTURBANCE RACES THROUGH LATE THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... WASHED OUT/STALLED SURFACE FRONT...REALLY MORE A WEAK PRESSURE TROUGH AT THIS POINT...RUNS FROM JUST WEST OF CKB TO JUST EAST OF HTS. DO HAVE SOME SOME MORE ENHANCED ECHOS SHOWING UP ALONG OR JUST WEST OF THIS BOUNDARY...AND ALSO IN NORTH CENTRAL WV. UPPED TO SCATTERED SHOWERS IN THESE AREA THROUGH THE EARLY MORNING. RAP SHOWS AN ELONGATED VORT LOBE MOVING ACROSS CWA THIS MORNING...SO KEEP SOME ISOLATED TO SCATTERED SHOWERS IN THE OHIO RIVER VALLEY TRANSITIONING MORE TO THE NORTHERN MOUNTAINS THIS AFTERNOON. LOW LEVEL MOISTURE STILL STRUGGLES TO CLEAR OUT...SO THINK PLENTY OF CLOUDS AROUND TODAY...EXCEPT VERY WESTERN CWA WHERE SATELLITE SHOWS CLEAR SKIES ALREADY DRIFTING IN. VORT LOBE AND ASSOCIATED POPS SHOULD BE MOVING OUT OF NORTHERN MOUNTAINS LATE AFTERNOON INTO EVENING...WITH A PRECIP FREE FORECAST BY LATE TONIGHT. COOLED HIGHS JUST A BIT TODAY WITH ABUNDANCE OF CLOUDS AND STAYED NEAR TO JUST ABOVE THE WARMER MET FOR LOWS TONIGHT. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AFTER A VERY STRANGE PATTERN OF LATE...WE FINALLY GET THE ATMOSPHERE MOVING AGAIN DURING THIS TUESDAY THROUGH THURSDAY NIGHT TIME PERIOD. SO SEVERAL FEATURES TO TIME. DRIER AIR AT 925 TO 850 MBS THAT IS OFF THE JERSEY COAST THIS PREDAWN SHOULD CONTINUE TO SNEAK BACK WSW AND REACH OUR MOUNTAINOUS COUNTIES FOR TUESDAY. SO EXPECTING LESS CLOUDS THERE DURING TUESDAY AFTERNOON...COMPARED TO SAY OUR OHIO COUNTIES. WARMEST DAY OF THE WEEK SHOULD BE TUESDAY. WITH THE 700 MB FLOW INCREASING IN THE LOWER OHIO VALLEY TUESDAY NIGHT. WAS JUST A BIT FASTER BRINGING BACK SOME CHANCE POPS FOR PREFRONTAL SHOWERS OVERNIGHT TUESDAY NIGHT IN THE WEST. ALSO...KEPT TEMPERATURES MILDER THAN MOST MOS GUIDANCE THERE. INITIAL TIMING OF FRONT IS THROUGH OUR OHIO RIVER VALLEY COUNTIES BY MIDDAY AND ACROSS THE MOUNTAINOUS COUNTIES BY SUNSET. SO...THE ONLY CHANGE WORTH MENTIONING WAS A BIT FASTER LOWERING POPS FROM WEST TO EAST. LEFT OUR FRONTAL POPS IN THE LIKELY RANGE...WAS NOT IMPRESSED ENOUGH TO RAISE TO CATEGORICAL. WITH THAT TIMING...LOWERED DAYTIME MAXIMUM TEMPERATURES A FEW DEGREES WEDNESDAY. WITH 850 TEMPERATURES DROPPING SOME 6 TO 8C OVERNIGHT WEDNESDAY NIGHT...HELD ONTO SOME POPS OVER THE MOUNTAIN COUNTIES...AS WE SQUEEZE OUT THE LOW LEVEL MOISTURE. YET...FURTHER WEST...AT LEAST PARTIAL CLEARING AS EVEN THE 850 MOISTURE THINS OUT. FOR THURSDAY AND THURSDAY NIGHT...THE MORE RECENT RUNS OF THE ECMWF HAVE COME AROUND TO WHAT THE GFS HAD BEEN ADVERTISING PREVIOUSLY. THE MID LEVEL DISTURBANCE RACES THROUGH HERE THURSDAY EVENING. MOISTURE INCREASES FOR THURSDAY AFTERNOON AND EVENING. SO HELD THURSDAY MORNING DRIER THAN OUR PREVIOUS FORECAST...BUT STILL INCREASED POPS THURSDAY AFTERNOON. THINK CLEARING WILL DEVELOP IN OUR WESTERN LOWLANDS THURSDAY NIGHT. WILL LOWER TEMPERATURES FOR DAWN FRIDAY...ESPECIALLY FOR SOUTHEAST OHIO...NORTHEAST KENTUCKY...AND SPILLING INTO A FEW RURAL AREAS OF WESTERN WEST VIRGINIA. HAVE SOME 35 TO 40 DEG TEMPERATURES THERE...WILL MENTION/ADD THE POSSIBILITY OF FROST IN A FEW SPOTS IN THE HAZARDOUS WEATHER POTENTIAL...BUT CURRENTLY DO NOT THINK IT WILL BE WIDESPREAD. && .LONG TERM /FRIDAY THROUGH SUNDAY/... MODELS ARE HAVING DISAGREEMENTS ON HANDLING A SOUTHERN STREAM SYSTEM ON THURSDAY IN THE SPLIT FLOW UPPER AIR PATTERN. ALL AGREE THAT A NORTHERN STREAM SHORT WAVE AND ASSOCIATED COLD FRONT WILL QUICKLY EXIT EARLY WEDNESDAY NIGHT...TAKING THE SHOWERS WITH IT. SOME COOLER AND DRIER AIR DOES FLOW IN BEHIND THIS FRONT WEDNESDAY NIGHT. THE BIG QUESTION BECOMES WHAT HAPPENS TO A CHUNK OF ENERGY LEFT OVER THE SOUTHERN ROCKIES AS IT GETS QUICKLY EJECTED BY ANOTHER NORTHERN STREAM SHORT WAVE DROPPING OUT OF WESTERN CANADA. WILL GO WITH PERSISTENCE IN OUR FORECAST AND ENOUGH MODEL CONSENSUS...USING LATEST GFS AND ECMWF MODELS AVAILABLE...WITH THIS SHORT WAVE LIFTING UP FAR ENOUGH WEST TO DRIVE SURFACE LOW PRESSURE NORTHEASTWARD FROM THE LOWER MISSISSIPPI VALLEY THRU THE MID ATLANTIC THURSDAY. THIS WILL BRING A SWATH OF RAIN ACROSS THE AREA THURSDAY...ESPECIALLY IN THE EAST. OTHERWISE...OUTSIDE A WEAK AND RATHER MOISTURE LIMITED COOL FRONT SATURDAY...HIGH PRESSURE WILL GENERALLY DOMINATE FRIDAY THRU THE WEEKEND. EXPECT TEMPERATURES TO BE A LITTLE BELOW NORMAL FOR THIS TIME OF YEAR...BUT NO SIGNIFICANT FREEZE/FROST OUTSIDE THE HIGHER ELEVATIONS OF THE WEST VIRGINIA IS EXPECTED THRU THE WEEKEND. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... CURRENT OBS SHOW IFR CIGS ACROSS THE LOWLANDS...WITH VFR ACROSS THE MOUNTAINS...HOWEVER EXPECT EASTERN CWA TO GRADUALLY DROP BACK INTO MVFR AND IFR AT BKW THROUGH THE REMAINDER OF THE EARLY MORNING. COULD SEE SOME POCKETS OF FOG...BUT EXPECT IT TO REMAIN MOSTLY OF THE MVFR VARIETY WITH DENSE CLOUD COVER. CLEAR SKIES ON SATELLITE JUST INTO WESTERN CWA...AND COULD SEE THIS PUSH TOWARDS HTS...AND POSSIBLY PKB OVER THE NEXT 6 HOURS...BUT SIDED WITH MODEL SOUNDINGS IN KEEPING CLOUDS IN PLACE. SHOULD IT CLEAR...DENSE FOG WOULD BE POSSIBLE. SLOWED DOWN RETURN TO VFR TODAY...HOWEVER ALL SITES SHOULD REBOUND AS THE DAY GOES ALONG WITH SOME ISOLATED TO SCATTERED SHOWERS DRIFTING AROUND AS A VORT LOBE PASSES. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATIVE SCENARIOS: HTS MAY CLEAR AND FOG. TIMING OF CIG CAT CHANGES ACROSS CWA MAY VARY...WITH SOME BOUNCING AROUND POSSIBLE. 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 MON 10/14/13 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15 CRW CONSISTENCY L L H H H H H H H H H H HTS CONSISTENCY L M M M M M H H H H H H BKW CONSISTENCY L L L 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 L 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 TUESDAY... IFR POSSIBLE IN CONVECTION WEDNESDAY WITH A COLD FRONT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/MZ NEAR TERM...MZ SHORT TERM...KTB LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
733 PM CDT TUE OCT 15 2013 .UPDATE...LATEST SURFACE MAP SHOWS THE COLD FRONT EAST OF ST. LOUIS AND LITTLE ROCK, WITH WIDESPREAD SHOWERS WEST OF MIDDLE TENNESSEE. HOWEVER, THE ONGOING ACTIVITY IS HAVING A HARD TIME MAKING EASTWARD PROGRESSION GIVEN THE DRIER, STABLE AIR OF MIDDLE TENNESSEE. LATEST HRRR IS OVERPLAYING CURRENT PRECIPITATION, AND EVEN THEN SHOWS LITTLE ACTIVITY MAKING IT EAST OF I-65 PRIOR TO 06Z. THEREFORE, AM SCALING BACK EVENING POP`S, BUT MAKING NO CHANCES THEREAFTER. && .PREV DISCUSSION... /ISSUED 642 PM CDT TUE OCT 15 2013/ UPDATE...FOR 00Z AVIATION. AVIATION...00Z TAF DISCUSSION. LIGHT RAINS ARE BEING SEEN ACROSS OUR WESTERN COUNTIES AT ISSUANCE...BUT IT`S GOING TO TAKE AWHILE FOR THE AIR TO SATURATE AND DROP CIGS. WILL CONTINUE WITH VFR FLIGHT CATEGORIES UNTIL AROUND SUNRISE FOR KCKV AND KBNA. RAIN RATES SHOULD PICK UP AROUND THIS TIME AND HELP TO PROVIDE LOWERED CIGS...THOUGH NOT EXPECTING ANYTHING LESS THAN MVFR ATTM. RAINS ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE TAF CYCLE. WINDS WILL BE SLOW TO SHIFT AS THE FRONT ASSOCIATED WITH THESE RAINS DRAGS THROUGH MIDDLE TENNESSEE. SHOULD SEE A SHIFT TO THE NW AT CKV BY 12Z...BUT MAY BE MID-AFTERNOON BEFORE KBNA SEES IT. EITHER WAY...WINDS ARE EXPECTED TO BE LIGHT. UNGER PREV DISCUSSION... /ISSUED 357 PM CDT TUE OCT 15 2013/ DISCUSSION... FORECAST REASONING WILL LEAN TOWARD A CONSENSUS MODEL SOLUTION COMPROMISE FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED. FORECAST QUANDARIES...ANY CHANCES OF TSTMS LATE AFTERNOON AND EVENING... TOTAL RAINFALL AMOUNTS THRU THURSDAY...WX PATTERN LATE WEEK INTO FIRST PART OF NEXT WEEK...TEMPS. WILL BE BREAKING OUT A LATE AFTERNOON GROUPING IN THE ZONE FORECAST PRODUCT FOR TRANSITIONAL PURPOSES TO THE TONIGHT PERIOD AS SHWRS JUST STARTING TO ENTER NW PORTIONS OF MID STATE. MAY SEE AN ISO TSTMS HERE OR THERE...BUT BELIEVE AT BEST THIS WILL BE ACROSS FAR NW PORTIONS OF THE MID STATE... APPROACHING THE LAND BETWEEN THE LAKES REGION AND LAST ONLY INTO THE MID EVENING HRS TONIGHT AND WITH SUCH MARGINAL INSTABILITY EXPECTED REMAINDER OF TONIGHT AND INTO WED...WILL NOT MENTION TSTMS DURING THOSE TIME PERIODS. DO NOT ALSO ANTICIPATE ANY ORGANIZED HEAVY RAINFALL POTENTIAL...WITH QPF VALUES GENERALLY RANGING FROM AROUND ONE QUARTER OF AN INCH PLATEAU TO AROUND THREE QUARTERS OF AN INCH TN RIVER VALLEY THRU WED AFTERNOON. SFC COLD FRONT SHOULD APPROACH NW PORTIONS OF THE MID STATE BY 12Z WED...AND THEN MOVE SLOWLY ACROSS THE MID STATE...AS IT WILL BECOME INCREASINGLY PARALLEL WITH FLOW ALOFT...BEING POSITIONED NEAR THE PLATEAU COUNTIES BY 00Z THU. DESPITE NOT EXPECTING A LOT OF RAINFALL WITH THIS SYSTEM...SKIES WILL REMAIN CLOUDY WITH LOWS TONIGHT IN THE UPPER 50S PLATEAU TO LOWER 60S ELSEWHERE. GFS MOS VALUES CONTINUE THEIR RECENT TREND OF BEING GENERALLY A COUPLE OF DEGREES TOO COOL ON LOWS AND THUS ADJUSTED TEMPS ACCORDINGLY. WHAT THIS FRONTAL PASSAGE WILL BRING WITH IT IS COOLER HIGH TEMPS STARTING ON WED...WITH TEMPS REMAINING IN THE 60S...POSSIBLY APPROACHING 70S PLATEAU AHEAD OF FRONTAL PASSAGE DURING THE AFTERNOON HRS ON WED. STILL ALSO EXPECTING SFC FRONT TO MOVE SLOWLY EWD FROM PLATEAU COUNTIES ON WED NIGHT INTO THU...ALLOWING THE DEEPEST MOISTURE TO REMAIN ACROSS THE PLATEAU COUNTIES WITH AN UPPER LEVEL LOW PASSING ACROSS THE SRN GREAT LAKES REGION BRINGING WITH IT A TROUGH ACROSS THE MID STATE AS THU PROGRESSES...RESULTING IN A CONTINUED CHANCE OF SHWRS WED NIGHT INTO THU... WITH QFP VALUES RANGING FROM LESS THAN A TENTH OF AN INCH ACROSS NW PORTIONS OF THE MID STATE WHERE DRIER AIR WILL TRY TO WORK IN TO APPROACHING ONE HALF OF AN INCH ACROSS THE PLATEAU REGION. THIS DRIER AIR THAT IS TRYING TO WORK IN BEHIND THE SFC FRONTAL PASSAGE WILL RESULT IN LOWS WED NIGHT MID TO UPPER 40S NW TO LOW 50S PLATEAU AND LOCATIONS NEAR THE TN/AL BORDER. WITH SKIES REMAINING MOCLDY TO CLDY THRU THIS TIME PERIOD...HIGHS WILL ALSO CONTINUE TO FALL A FEW DEGREES MORE BELOW SEASONABLE VALUES FOR THIS TIME OF YEAR WITH HIGHS MAINLY IN THE MID 60S. IT LOOKS LIKE SFC RIDGING INFLUENCES WILL BUILD IN FROM THE SW WITH A SPLIT UPPER LEVEL FLOW PATTERN DEVELOPING ACROSS THE MID STATE INTO THE WEEKEND... WITH EVENTUALLY BROAD UPPER LEVEL TROUGHING TO THE NORTH BECOMING THE DOMINANT UPPER LEVEL FEATURE INTO THE FIRST PART OF NEXT WEEK. ANOTHER SFC FRONT SHOULD MOVE THRU THE MID STATE ON SAT...BUT IT LOOKS AS OF THIS TIME TO BRING ONLY SOME ADDITIONAL CLOUDINESS AND A SHIFT TO MORE NLY SFC WINDS...AND NO PCPN. SFC RIDGING INFLUENCES FROM THE N WILL THEN TRY TO BUILD ACROSS THE MID STATE THRU THE FIRST PART OF NEXT WEEK ALSO. SO EXPECTING GENERALLY PTCLDY SKIES AND DRY CONDITIONS DURING THIS PERIOD WITH TEMPS AT OR SLIGHTLY BELOW SEASONABLE NORMAL VALUES...AS HIGHS WILL GENERALLY BE IN THE MID TO UPPER 60S WITH LOWS IN THE MID TO UPPER 40S. RECENT MEX MOS GUIDANCE HAS BEEN JUST A LITTLE WARM ON HIGHS AS OF LATE AND CUT BACK THOSE VALUES BY A FEW DEGREES ALSO. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ROSE
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1231 AM CDT MON OCT 14 2013 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...DEBRI CLOUDS FROM THUNDERSTORM ACTIVITY ACROSS SOUTH CENTRAL TEXAS WILL SPREAD SOUTHWARD INTO THE RIO GRANDE VALLEY TONIGHT. THUNDERSTORMS ARE EXPECTED TO IMPACT ZAPATA AND JIM HOGG COUNTY UNTIL SUNRISE PRODUCING MODERATE TO HEAVY RAIN GUSTY WINDS AND FREQUENT CLOUD TO GROUND LIGHTNING. EXPECT MVFR CONDITIONS DEVELOPING DURING THE EARLY MORNING HOURS OVER KBRO... KHRL AND KMFE IMPROVING AFTER SUNRISE. BREEZIER SE WINDS WILL DEVELOP MONDAY WITH ISOLATED SHOWERS POSSIBLE IN THE AFTERNOON HOURS. && .PREV DISCUSSION... /ISSUED 929 PM CDT SUN OCT 13 2013/ DISCUSSION...MONITORING CONVECTION THAT HAS SO FAR REMAINED TO THE NORTHWEST OF THE CWA. HOWEVER TRENDS OVER THE LAST COUPLE OF HOURS IN WATER VAPOR IMAGERY SUGGEST THAT A RIPPLE IN THE SUBTROPICAL JET...WHICH IS BEING ENHANCED BY OUTFLOW OF TS OCTAVE WILL LEAD TO STRONGER DIFFLUENCE PUSHING SOUTHEAST AND HOLDING THROUGH SUNRISE. LOW LAYER ANALYSIS AND THE NAM12/RAP SUGGEST INCREASING CONVERGENCE OVER MAINLY JIM HOGG/ZAPATA COUNTY OVER THE NEXT COUPLE OF HOURS. THERE IS FAIRLY WEAK BUT NONZERO INSTABILITY AND DEEP MOISTURE WITH SATELLITE AND RAP PWAT ESTIMATES AROUND 2.2 INCHES WHICH IS REASONABLY IN LINE WITH 00Z REGIONAL BALLOON RELEASES. WITH AT LEAST SOME BAROCLINICITY IN THE 850/700MB LAYER MORE FOCUSED REGIONAL TROUGHING COULD SET UP ALONG OUR NORTHWESTERN ZONES THROUGH THE NIGHT AS WELL. CONSIDERING THE ABOVE HAVE RAISED PRECIP CHANCES THROUGH THE OVERNIGHT MAINLY IN ZAPATA/BROOKS/STARR/JIM HOGG COUNTIES. LOCAL FLOODING RISK STILL APPEARS LIMITED BY A STABILIZING BOUNDARY LAYER BUT WILL CONTINUE TO MONITOR. -JGG/GB PREV DISCUSSION... /ISSUED 622 PM CDT SUN OCT 13 2013/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...GUSTY SOUTHEAST WINDS WILL FALL TO AROUND 7 TO 10 KNOTS OVER THE NEXT FEW HOURS. CONVECTION IS EXPECTED TO REMAIN NORTHWEST OF THE TAF SITES BUT ISOLATED ACTIVITY IS POSSIBLE ACROSS JIM HOGG AND ZAPATA COUNTY THROUGH THE EARLY EVENING. DRIER AIR AROUND 3000 FT IS EXPECTED TO HELP KEEP CIGS VFR BUT PATCHY HIGH MVFR IS POSSIBLE...ESPECIALLY AROUND SUNRISE AND HAVE INCLUDED A TEMPO GROUP DURING THAT TIME PERIOD. CLOUD DECKS SHOULD RISE ABOVE 3000 FT AND BECOME SCATTERED TO FEW BY MID MORNING AS SOUTHEASTERLY WINDS INCREASE AND PERSIST THROUGH THE DAY ON MONDAY. /68-JGG/ PREV DISCUSSION... /ISSUED 319 PM CDT SUN OCT 13 2013/ SHORT TERM /NOW THROUGH MONDAY NIGHT/...H5 RIDGE CONTINUES TO SPIN JUST OT THE SOUTH...WITH MOISTURE CONTINUING TO WRAP AROUND IT. WEAK IMPULSE EXPECTED TODAY WENT FURTHER NORTH THAN FORECAST...SO SHOWERS HAVE BEEN ISOLATED AND HAVE FOR THE MOST PART MOVED OFF TO THE NORTH. MOISTURE IS FORECAST TO GET SHUNTED FURTHER NORTHWARD DURING THE NEXT 12 HOURS...WHILE MUCH DRIER AIR NOTED TO THE SOUTH ON WV IMAGERY WILL REPLACE IT STARTING TONIGHT. THIS SHOULD PUT AN END TO THE POP CHANCES FOR THE SHORT TERM PERIOD. TEMPERATURES WILL AGAIN RISE INTO THE LOW 90S TOMORROW WITH ANOTHER HUMID DAY IN STORE. LONG TERM /TUESDAY THROUGH SUNDAY/...THE 500 MB RIDGING IN PLACE OVER THE GULF OF MEX AND SOUTHERN TX WILL BE STEADILY ERODED AWAY LATER THIS WEEK AS A SERIES OF STRONG SHORT WAVES WILL DIG ACROSS THE WESTERN AND CENTRAL STATES. THIS WILL PUSH A COLD FRONT THROUGH DEEP SOUTH TX LATE WED NIGHT/EARLY THURS MORNING WITH A SECOND FRONT PUSHING ACROSS CENTRAL AND SOUTHERN TX THIS SATURDAY. AS THE MID LEVEL RIDGING ERODES AWAY THE DEEPER LAYER MOISTURE FEED (WHICH IS BEING ENHANCED FROM THE LEFT OVER MOISTURE FROM T.S. OCTAVE IN THE EASTERN PAC) WILL SHIFT STEADILY SOUTHWARDS AHEAD OF THE NEXT FRONT INCREASING THE CONV POTENTIAL DURING THE LATER HALF OF THE WEEK. THE OLD COLD FRONT WILL REMAIN STATIONARY TO THE SOUTH OF THE REGION ON SUN WITH BROAD HIGH PRESSURE SPREADING OVER MUCH OF THE CENTRAL AND EASTERN STATES. BOTH THE ECMWF AND GFS GENERALLY AGREE IN THE HANDLING OF THE SYNOPTIC FEATURES AND THE OVERALL MOISTURE TRENDS THROUGH THURS. AT THIS POINT THE GFS DEVIATES FROM THE ECMWF AND TRIES TO DEVELOP A SURFACE COASTAL LOW NEAR THE LOWER TX COASTLINE AND LIFTS THIS FEATURE SLOWLY NORTHEAST NEXT WEEKEND. THE ECMWF DOES NOT REFLECT THIS FEATURE AS WELL AND TENDS TO WANT TO DRY OUT THE AREA MUCH FASTER AS SURFACE RIDGING STRENGTHENS OVER THE REGION. FOR NOW WILL GO CLOSE TO THE GFS SOLUTION THROUGH THURS AND WILL LEAN TOWARDS THE ECMWF SOLUTION FOR THE WEEKEND. OVERALL CONFIDENCE FOR THE LONGER RANGE PERIOD IS ABOVE AVERAGE THROUGH AROUND THURS AND IS THEN ONLY AVERAGE AFTER THURS DUE TO THE MODEL DIFFERENCES. WILL GO FAIRLY CLOSE TO GFS MEX MOS TEMPS THROUGH THE WEEKEND AND WILL LEAN TOWARDS THE DRIER ECMWF POPS AFTER THURSDAY. MARINE...NOW THROUGH MONDAY NIGHT...MINIMAL CHANGE IN MARINE FORECAST THROUGH THE NEXT 36 HOURS. WEAK RIDGING CONTINUES ACROSS THE NORTHERN GULF...WHILE THE NEXT COLD FRONT ENTERS NORTH TEXAS. WINDS WILL REMAIN IN THE 10 TO 15 KNOT RANGE THROUGH MONDAY NIGHT...WHILE SEAS STAY GENERALLY BETWEEN 3 AND 4 FEET. TUESDAY THROUGH FRIDAY...A LIGHT TO MODERATE SE FLOW WILL PREVAIL TUES AND WED AHEAD OF THE NEXT FRONT. A MODERATE TO STRONG N-NE FLOW WILL DOMINATE IN BEHIND THE FRONT ON THURS. HOWEVER ONLY BORDERLINE SCA CONDITIONS MAY OCCUR AS THE STRONG PGF MAY BE FAIRLY SHORT LIVED. A MODERATE ONSHORE FLOW WILL PREVAIL INTO FRI AS SURFACE RIDGING SAGS OVER THE GULF OF MEX. THIS WILL MAINTAIN MODERATES SWELLS AS THE WEEKEND APPROACHES. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 67/61
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AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1039 PM CDT TUE OCT 15 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY ISSUED AT 255 PM CDT TUE OCT 15 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN OCCLUDED LOW PRESSURE SYSTEM MOVING NORTHEAST ACROSS SOUTHERN MINNESOTA AND AN OCCLUDED/COLD FRONT SHIFTING EAST OVER SOUTHWEST WISCONSIN. LEADING BAND OF WARM CONVEYOR BELT RAIN IS NOW EXITING NORTHEAST WISCONSIN TO THE EAST...WHILE THE COLD FRONT IS MOSTLY INACTIVE. THE OVERCAST CLOUD DECK EXTENDS ALL THE WAY BACK TO THE CENTRAL ROCKIES HOWEVER...THOUGH SOME BREAKS WERE DEVELOPING RIGHT BEHIND THE FRONT OVER EASTERN IOWA. THIS AREA OF BROKEN CLOUDS MAY MAKE A RUN AT CENTRAL WISCONSIN LATE THIS AFTERNOON. WITHIN THE ELONGATED LOW OVERCAST DECK...THE TROWAL AIRSTREAM IS PRODUCING WIDESPREAD SHOWERS AND DRIZZLE OVER MINNESOTA AND SOUTH DAKOTA. AS THE LOW CONTINUES TO MOVE NORTHEAST...PRECIP CHANCES/TIMING ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW PRESSURE WILL BE MOVING NORTHEAST ACROSS NORTH-CENTRAL WISCONSIN WHILE THE COLD FRONT WILL SWEEP ACROSS NORTHEAST WISCONSIN AT THE SAME TIME. WITH THE DRY SLOT OVERHEAD AND PRONOUNCED CAPPING AT 700MB...NOT EXPECTING ANY THUNDER TO DEVELOP ALONG THE FRONT. BUT ENOUGH SHALLOW MOISTURE WILL BE PRESENT FOR SPOTTY SHOWERS AND AREAS OF DRIZZLE...ESPECIALLY OVER THE HIGHER TERRAIN OF N-C WISCONSIN. BY MID TO LATE EVENING THOUGH...DEEPER WRAP AROUND MOISTURE WILL ARRIVE FROM THE NORTHWEST...WHICH ALONG WITH SHARP SURFACE TROUGHING...SHOULD LEAD TO WIDESPREAD SHOWERS RETURNING TO CENTRAL AND NORTH-CENTRAL WISCONSIN. THESE SHOWERS WILL MOVE SOUTHEAST OVER THE COURSE OF THE NIGHT AND EVENTUALLY REACH NORTHEAST WISCONSIN DURING THE OVERNIGHT HOURS. OTHERWISE...SHOULD SEE PLENTY OF LOW OVERCAST WITH LOWS REMAINING IN THE 40S. WEDNESDAY...LOW PRESSURE WILL EXIT TO THE NORTHEAST...BUT THE SURFACE TROUGH WILL DROP ACROSS NORTHEAST WISCONSIN DURING THE MORNING. WITH PLENTY OF MOISTURE ALOFT...SO SHOULD SEE SHOWERS CONTINUE ACROSS THE EAST. WILL INCREASE POPS INTO THE LIKELY RANGE. THE SHOWERS WILL END FROM NORTHWEST TO SOUTHEAST FROM LATE MORNING TO EARLY AFTERNOON AS THE MID-LEVEL MOISTURE AND THE SURFACE TROUGH DEPARTS. DRIER AIR FROM THE WEST WILL THEN SLOWLY ADVECT INTO THE AREA DURING THE AFTERNOON. WILL STILL HAVE CYCLONIC FLOW AROUND THOUGH...SO DELAYED THE CLEARING TREND BY A FEW HOURS. WESTERN SECTIONS SHOULD SEE SOME SUN BY LATE AFTERNOON. HIGHS MAINLY IN THE LOW TO MID 50S. .LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY ISSUED AT 255 PM CDT TUE OCT 15 2013 MAIN ISSUES THIS PERIOD IN TIMING OF PCPN CHANCES. OVERALL PATTERN WILL CONTINUE TO BE HIGHLY AMPLIFIED WITH STRONG RIDGING ALONG THE WEST COAST AND BROAD TROUGH OVER MUCH OF THE THE CENTRAL PORTION OF CONUS. COOL...CYCLONIC FLOW WILL PRODUCE PERIODS OF SHOWERS FROM TIME TO TIME...THOUGH TRYING TO TIME ENERGY MOVING THROUGH TROF BETWEEN MODELS IS DIFFICULT AS CHANGES FROM RUN TO RUN. HAVE CONTINUED CHANCES FOR SNOW AT TIMES LATE IN THE PERIOD...THOUGH THERE CONTINUES TO BE DIFFERENCES IN LLVL THERMAL FIELDS. MOISTURE FOR PCPN ALSO DIMINISHES WITH TIME AS FLOW COMING OUT OF CANADA. STAYED WITH LOW CHANCE POPS THROUGH EXTENDED. IN NEAR TERM...RIDGING OVERNIGHT WED TO LEAD TO DRY PERIOD. LIGHT WINDS AND COLD TEMPERATURES TO LEAD TO FROST POTENTIAL. WILL NEED TO MONITOR CLOUD TRENDS FOR THIS PERIOD...AT THIS TIME LOOKS LIKE WILL HAVE ENOUGH CLEARING BETWEEN EXITING/ENTERING SYSTEMS. FROST PUT IN GRIDS ONLY FOR EAST CENTRAL WHERE HEADLINES STILL BEING ISSUED. LAKE ENHANCEMENT OF SHOWER ACTIVITY LOOKS MINIMAL AT THIS TIME WITH WINDS REMAINING TOO WESTERLY. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1039 PM CDT TUE OCT 15 2013 LOW PRESSURE MOVING ACROSS NORTHERN WISCONSIN WILL KEEP OCCASIONAL LIGHT RAIN AND MAINLY IFR CEILINGS NORTH OF A WAUSAU/CENTRAL WISCONSIN TO IRON MOUNTAIN LINE. FURTHER SOUTH CEILINGS WILL BE MOSTLY MVFR WITH SOME AREAS OF IFR. CONDITIONS SHOULD BECOME VFR FROM WEST TO EAST WEDNESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......TE AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
634 PM CDT TUE OCT 15 2013 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY ISSUED AT 255 PM CDT TUE OCT 15 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN OCCLUDED LOW PRESSURE SYSTEM MOVING NORTHEAST ACROSS SOUTHERN MINNESOTA AND AN OCCLUDED/COLD FRONT SHIFTING EAST OVER SOUTHWEST WISCONSIN. LEADING BAND OF WARM CONVEYOR BELT RAIN IS NOW EXITING NORTHEAST WISCONSIN TO THE EAST...WHILE THE COLD FRONT IS MOSTLY INACTIVE. THE OVERCAST CLOUD DECK EXTENDS ALL THE WAY BACK TO THE CENTRAL ROCKIES HOWEVER...THOUGH SOME BREAKS WERE DEVELOPING RIGHT BEHIND THE FRONT OVER EASTERN IOWA. THIS AREA OF BROKEN CLOUDS MAY MAKE A RUN AT CENTRAL WISCONSIN LATE THIS AFTERNOON. WITHIN THE ELONGATED LOW OVERCAST DECK...THE TROWAL AIRSTREAM IS PRODUCING WIDESPREAD SHOWERS AND DRIZZLE OVER MINNESOTA AND SOUTH DAKOTA. AS THE LOW CONTINUES TO MOVE NORTHEAST...PRECIP CHANCES/TIMING ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW PRESSURE WILL BE MOVING NORTHEAST ACROSS NORTH-CENTRAL WISCONSIN WHILE THE COLD FRONT WILL SWEEP ACROSS NORTHEAST WISCONSIN AT THE SAME TIME. WITH THE DRY SLOT OVERHEAD AND PRONOUNCED CAPPING AT 700MB...NOT EXPECTING ANY THUNDER TO DEVELOP ALONG THE FRONT. BUT ENOUGH SHALLOW MOISTURE WILL BE PRESENT FOR SPOTTY SHOWERS AND AREAS OF DRIZZLE...ESPECIALLY OVER THE HIGHER TERRAIN OF N-C WISCONSIN. BY MID TO LATE EVENING THOUGH...DEEPER WRAP AROUND MOISTURE WILL ARRIVE FROM THE NORTHWEST...WHICH ALONG WITH SHARP SURFACE TROUGHING...SHOULD LEAD TO WIDESPREAD SHOWERS RETURNING TO CENTRAL AND NORTH-CENTRAL WISCONSIN. THESE SHOWERS WILL MOVE SOUTHEAST OVER THE COURSE OF THE NIGHT AND EVENTUALLY REACH NORTHEAST WISCONSIN DURING THE OVERNIGHT HOURS. OTHERWISE...SHOULD SEE PLENTY OF LOW OVERCAST WITH LOWS REMAINING IN THE 40S. WEDNESDAY...LOW PRESSURE WILL EXIT TO THE NORTHEAST...BUT THE SURFACE TROUGH WILL DROP ACROSS NORTHEAST WISCONSIN DURING THE MORNING. WITH PLENTY OF MOISTURE ALOFT...SO SHOULD SEE SHOWERS CONTINUE ACROSS THE EAST. WILL INCREASE POPS INTO THE LIKELY RANGE. THE SHOWERS WILL END FROM NORTHWEST TO SOUTHEAST FROM LATE MORNING TO EARLY AFTERNOON AS THE MID-LEVEL MOISTURE AND THE SURFACE TROUGH DEPARTS. DRIER AIR FROM THE WEST WILL THEN SLOWLY ADVECT INTO THE AREA DURING THE AFTERNOON. WILL STILL HAVE CYCLONIC FLOW AROUND THOUGH...SO DELAYED THE CLEARING TREND BY A FEW HOURS. WESTERN SECTIONS SHOULD SEE SOME SUN BY LATE AFTERNOON. HIGHS MAINLY IN THE LOW TO MID 50S. .LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY ISSUED AT 255 PM CDT TUE OCT 15 2013 MAIN ISSUES THIS PERIOD IN TIMING OF PCPN CHANCES. OVERALL PATTERN WILL CONTINUE TO BE HIGHLY AMPLIFIED WITH STRONG RIDGING ALONG THE WEST COAST AND BROAD TROUGH OVER MUCH OF THE THE CENTRAL PORTION OF CONUS. COOL...CYCLONIC FLOW WILL PRODUCE PERIODS OF SHOWERS FROM TIME TO TIME...THOUGH TRYING TO TIME ENERGY MOVING THROUGH TROF BETWEEN MODELS IS DIFFICULT AS CHANGES FROM RUN TO RUN. HAVE CONTINUED CHANCES FOR SNOW AT TIMES LATE IN THE PERIOD...THOUGH THERE CONTINUES TO BE DIFFERENCES IN LLVL THERMAL FIELDS. MOISTURE FOR PCPN ALSO DIMINISHES WITH TIME AS FLOW COMING OUT OF CANADA. STAYED WITH LOW CHANCE POPS THROUGH EXTENDED. IN NEAR TERM...RIDGING OVERNIGHT WED TO LEAD TO DRY PERIOD. LIGHT WINDS AND COLD TEMPERATURES TO LEAD TO FROST POTENTIAL. WILL NEED TO MONITOR CLOUD TRENDS FOR THIS PERIOD...AT THIS TIME LOOKS LIKE WILL HAVE ENOUGH CLEARING BETWEEN EXITING/ENTERING SYSTEMS. FROST PUT IN GRIDS ONLY FOR EAST CENTRAL WHERE HEADLINES STILL BEING ISSUED. LAKE ENHANCEMENT OF SHOWER ACTIVITY LOOKS MINIMAL AT THIS TIME WITH WINDS REMAINING TOO WESTERLY. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 634 PM CDT TUE OCT 15 2013 LOW PRESSURE MOVING ACROSS NORTHERN WISCONSIN WILL KEEP OCCASIONAL LIGHT RAIN AND MAINLY IFR CEILINGS NORTH OF A RHINELANDER TO IRON MOUNTAIN LINE. FURTHER SOUTH CEILINGS SHOULD RISE INTO MVFR OR VFR RANGE WITH JUST SCATTERED SHOWERS. MVFR EXPECTED IN MOST PLACES WEDNESDAY MORNING WITH VFR IN THE AFTERNOON. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......TE AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 PM CDT MON OCT 14 2013 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 215 PM CDT MON OCT 14 2013 FOCUS OF THE FORECAST CONTINUES TO BE ON THE INCOMING SYSTEM AND RAIN CHANCES INTO WEDNESDAY. HIGH PRESSURE AT THE SURFACE HAS PUSHED EAST TO OVER EASTERN LAKE SUPERIOR AND LOWER MICHIGAN AS LOW PRESSURE HAS DEVELOPED IN THE LEE OF THE ROCKIES OVER WESTERN NEBRASKA. THE LOW HAS FORMED IN THE RESPONSE THE UPPER LEVEL LOW THAT IS OVER EASTERN WYOMING. THE 14.12Z MODELS CONTINUE TO BE IN EXCELLENT AGREEMENT ON THE HANDLING OF THIS SYSTEM WHICH LEADS TO HIGH CONFIDENCE ON THE OUTCOME. THE UPPER LEVEL LOW WILL MOVE NORTHEAST INTO THE UPPER MIDWEST TONIGHT INTO TUESDAY. AS IT DOES...IT WILL TAKE ON A POSITIVE TILT AS IT BECOMES ENTRAINED INTO THE MEAN LONG WAVE TROUGH EMANATING FROM THE STRONG CLOSED UPPER LEVEL LOW OVER HUDSONS BAY. EVEN AS THIS IS OCCURRING...THE MAIN SHORT WAVE TROUGH WITH THE WYOMING LOW IS FORECAST TO REMAIN STRONG AND BRING BETWEEN 8 AND 16 PVU/S OF VORTICITY ADVECTION IN THE 500 TO 300 MB LAYER ACROSS THE AREA LATE TONIGHT INTO EARLY TUESDAY MORNING. THIS CREATES STRONG AND DEEP QG CONVERGENCE IN THE 1000-300 MB LAYER OVERNIGHT WITH THIS THEN MOVING OFF TO THE NORTHEAST TUESDAY MORNING. EXCELLENT ISENTROPIC UP GLIDE IS EXPECTED TO OCCUR WITH THE MODELS SHOWING BETWEEN 4 AND 6 UBAR/S ON THE 295K SURFACE ALONG WITH THE MOISTURE TRANSPORT ON THIS LEVEL BEING INTO THE NORTHERN HALF OF THE FORECAST AREA THROUGH 12Z TUESDAY. ALL THIS FORCING WILL BE MORE THAN SUFFICIENT TO OVERCOME THE DRY AIR BROUGHT IN BY THE DEPARTING SURFACE HIGH AND EXPECT TO SEE RAIN SHOWERS OVERSPREAD THE AREA AFTER 03Z OR SO AND HAVE SPREAD 90 TO 100 PERCENT RAIN CHANCES ACROSS THE AREA TONIGHT. AS THE SHORT WAVE TROUGH STARTS TO MOVE OFF TUESDAY...THE SURFACE LOW IS EXPECTED TO MOVE FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN ALLOWING THE DRY SLOT TO EITHER APPROACH THE AREA OR MOVE INTO THE SOUTHERN SECTIONS TUESDAY AFTERNOON WITH THE MAIN BAND OF RAIN BECOMING ORIENTED INTO THE DEFORMATION BAND ON THE BACK SIDE OF THE SURFACE LOW. THIS DEFORMATION BAND WILL THEN MOVE ACROSS THE NORTHERN SECTIONS OF THE FORECAST AREA TUESDAY EVENING AND WILL SHOW 50 TO 70 PERCENT RAIN CHANCES NORTH OF I90 FOR THIS. THE WHOLE SYSTEM WILL THEN EXIT THE REGION WEDNESDAY AND JUST HELD ON TO SOME LINGERING CHANCES ACROSS THE EAST DURING THE MORNING BEFORE GOING DRY WEDNESDAY AFTERNOON. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 215 PM CDT MON OCT 14 2013 THE CLOSED LOW WILL REMAIN OVER HUDSONS BAY AND LOOKS TO SWING ANOTHER SHORT WAVE TROUGH...SURFACE LOW PRESSURE AREA AND COLD FRONT ACROSS THE UPPER MIDWEST AND GREAT LAKES TOWARD THE END OF THE WEEK. THERE COULD ALSO BE ANOTHER SYSTEM COMING THROUGH TO OVER THE WEEKEND. WITH THESE SYSTEMS...WILL SHOW SOME SMALL PRECIPITATION CHANCES...MAINLY 20 TO 30 PERCENT...FROM THURSDAY NIGHT THROUGH SATURDAY AND AGAIN FOR SUNDAY NIGHT AND MONDAY. WITH THE PASSAGE OF THE FIRST COLD FRONT...TEMPERATURES COULD GET COLD ENOUGH FOR SOME OF THE PRECIPITATION TO FALL AS SOME SNOW AND HAVE INCLUDED THIS ACROSS THE NORTH FOR FRIDAY NIGHT. OTHERWISE...TEMPERATURES WILL GENERALLY BE COOLING DOWN TO BE BELOW NORMAL WITH HIGHS IN THE 40S AND 50S AND LOWS IN THE 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 300 PM CDT MON OCT 14 2013 A LOW PRESSURE SYSTEM...CURRENTLY LOCATED OVER EASTERN NEBRASKA... WILL MOVE NORTHEAST ACROSS WESTERN IOWA AND SOUTH CENTRAL MINNESOTA THROUGH TUESDAY MORNING. AS THIS LOW APPROACHES THE AREA OF BAND OF SHOWERS WILL MOVE INTO KRST AROUND 15.03Z AND KLSE AROUND 15.06Z. WITH DRY AIR IN PLACE ACROSS THE REGION...IT WILL TAKE ABOUT 3 HOURS BEFORE THE CEILINGS WILL BECOME IFR/MVFR. THE CEILINGS WILL THEN LIKELY STAY THERE THROUGH THE REMAINDER OF TUESDAY MORNING. EXPECT THE VISIBILITIES TO BECOME MVFR AT KRST ABOUT THE SAME TIME THAT THE CEILINGS BECOME IFR...BUT WAS NOT AS CONFIDENT TO DO THE SAME AT KLSE....SO LEFT THEM OUT FOR NOW. WHILE THE BAND OF PRECIPITATION WILL BE NARROW...THE MODELS CONTINUE TO STRUGGLE ON WHEN THIS PRECIPITATION MIGHT END. THE LATEST RAP SUGGESTS THAT THIS WOULD OCCUR AT KRST BY 10Z AT KRST AND 13Z AT KLSE. HOWEVER THE NMM AND ARW SHOW THAT THIS PRECIPITATION WILL CONTINUE THROUGH THE MORNING. SINCE IT WAS UNCLEAR...WENT WITH A COMPROMISE AND ENDED IT AROUND 15.14Z AT KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...BOYNE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND TUESDAY ISSUED AT 233 PM CDT MON OCT 14 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE CENTERED OVER THE CENTRAL GREAT LAKES WHILE LOW PRESSURE IS DEVELOPING IN THE LEE OF THE ROCKIES. PLENTY OF HIGH CLOUDS ARE ALREADY ADVANCING ACROSS THE NORTHWEST HALF OF THE STATE THIS AFTERNOON. FAIRLY WIDESPREAD AREA OF SHOWERS AND ALSO SOME THUNDER AHEAD OF THE LOW AS WELL OVER THE PLAINS. AS THE LOW MOVES NE TOWARDS THE REGION...PRECIP TIMING AND IMPACTS ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TO SOUTHWEST MINNESOTA BY 12Z TUESDAY. AHEAD OF THE LOW...PLENTY OF DRY AIR IN THE LOW AND MID-LEVELS WILL INITIALLY KEEP THE COLUMN FROM SATURATING...SO WILL CONTINUE TO PORTRAY DRY CONDITIONS THROUGH THE EVENING. HIGH CLOUDS WILL BE INCREASING THOUGH ALONG WITH A STEADY EAST WIND WHICH WILL MAKE THE NIGHT RATHER CHILLY. BY LATE TONIGHT...INCREASING UPPER DIVERGENCE AND THE ARRIVAL OF THE WARM CONVEYOR BELT WILL BRING AN INCREASING THREAT OF PRECIP. A 40-50KT LLJ WILL TRANSPORT MOISTURE FROM AN OPEN GULF OF MEXICO WHICH WILL BRING IN PWATS UPWARDS OF AN INCH BY 09Z. SHOULD SEE A PRETTY SOLID PRECIP BAND ARRIVE BETWEEN 09-12Z OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. WITH A BRISK EAST WIND AND INCREASING CLOUDS...LOWS WILL BE WARMER AND MAINLY IN THE 40S. TUESDAY...THE LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE NORTHEAST TO NORTH-CENTRAL WISCONSIN BY 00Z WED. THE WARM CONVEYOR BELT WILL ALSO MOVE IN THE NE DIRECTION ACROSS THE FORECAST AREA DURING THE MORNING...WHICH WILL GIVE THE ENTIRE AREA A DECENT CHANCE OF SEEING A QUARTER TO A HALF INCH (OR MORE) OF RAINFALL. THOUGH ELEVATED INSTABILITY IS PROGGED TO REMAIN UNDER 100 J/KG...DO NOT THINK WE CAN RULE OUT A LIGHTNING STRIKE OR TWO ALONG THE LEADING EDGE OF THE DRY SLOT. WILL KEEP A MENTION IN THE FORECAST. PLENTY OF WIND ALOFT TO BE BROUGHT DOWN BY ANY CONVECTIVE SHOWERS SO WILL LEAVE A MENTION IN THE HWO. A DRY SLOT WILL THEN MOVE ACROSS THE REGION DURING THE AFTERNOON ABOVE THE SURFACE COLD FRONT. PROGGED SOUNDINGS SHOW THE MID-LEVELS DRYING OUT ABOVE 700MB WHERE A DECENT CAP WILL DEVELOP. AS A RESULT...THINK WILL SEE AN ISOLATED LIGHTNING STRIKE AT BEST ALONG THE FRONT...THOUGH ANY SHOWERS COULD STILL BRING A DECENT WIND GUST. HIGHS AROUND 50 NORTH TO THE UPPER 50S SOUTH. .LONG TERM...TUESDAY NIGHT THROUGH MONDAY ISSUED AT 233 PM CDT MON OCT 14 2013 NO NOTABLE CHANGES TO PREVIOUS FORECAST WITH WESTERN GREAT LAKES GENERALLY UNDER THE INFLUENCE OF MEAN LONGWAVE TROUGH INTO EARLY NEXT WEEK. THIS PATTERN WILL SPELL A GENERALLY UNSETTLED PERIOD WITH TEMPERATURES BELOW NORMAL FOR MID OCTOBER. WILL STILL BE DEALING WITH WEAKENING LOW PRESSURE SYSTEM AND ATTENDANT SW-NE ORIENTATED DEFORMATION ZONE ON TUESDAY NIGHT. STILL SOME UNCERTAINTY WITH RESPECT TO TIMING AND NORTHERN PENETRATION OF DRY SLOT AS SURFACE LOW PASSES ACROSS THE FORECAST AREA. OVERALL MODEL CONSENSUS SUGGESTS THAT SWATH OF HEAVIEST PRECIPITATION ON NORTHEAST QUADRANT OF THE SYSTEM SHOULD BE EXITING THE NORTHEAST THIRD OF THE FORECAST AREA BY AROUND 00Z WEDNESDAY...WITH MID-LEVEL DRY INTRUSION PUSHING NORTHWARD TO ABOUT THE HIGHWAY 29 CORRIDOR SOMETIME BETWEEN 00Z AND 06Z TUESDAY NIGHT. THIS SCENARIO WOULD SUGGEST THAT THE MORE PERSISTENT LIGHT TO MODERATE RAINFALL WILL EXIST MAINLY NORTH OF THIS LINE. WOULD EXPECT A BRIEF LULL IN THE PRECIPITATION OVER THE FOX VALLEY AND/OR SOME DRIZZLE FOR A TIME TUESDAY EVENING. REMANANTS OF ERODING DEFORMATION ZONE...AND ASSOCIATED SCATTERED SHOWER ACTIVITY TO SWING ACROSS THE FORECAST AREA AFTER MIDNIGHT. UPPER TROUGH AXIS AND ASSOCIATED SECONDARY SURFACE REFLECTION STILL ON TRACK TO PUSH ACROSS THE FORECAST AREA WEDNESDAY MORNING. ENOUGH FORCING WITH THIS FEATURE IN CONCERT WITH RESIDUAL MOISTURE TO KEEP HIGH-END CHANCE POPS GOING THROUGH ABOUT MIDDAY AS PER PREVIOUS FORECAST. WILL FEEL RATHER FALL-LIKE ON WEDNESDAY WITH BRISK NORTHWEST WINDS AND MOSTLY CLOUDY SKIES LENDING TO DAYTIME HIGHS MAINLY IN THE LOW TO MID 50S. VERY WEAK RIDGING AND SUFFCIENTLY DRY AIRMASS SHOULD BRING A DRY DAY ON THURSDAY WITH PERHAPS A SLIGHT INCREASE IN MAX TEMPS UNDER PARTLY SUNNY SKIES. WILL START OUT RATHER COOL HOWEVER WITH TEMPERATURES EARLY THURSDAY MORNING FALLING BELOW FREEZING ACROSS THE NORTH WITH SOME FROST AGAIN POSSIBLE ACROSS THE FOX VALLEY. CONFIDENCE WANES AS WE GET INTO THE UPCOMING WEEKEND AS DEEPENING UPPER TROUGH SETTLES OVER HUDSON BAY EJECTING WEAK DISTURBANCES SOUTHEASTWARD TOWARD THE WESTERN GREAT LAKES. DID NOT FEEL COMFORTABLE TRYING TO TWEAK TIMING SO PRETTY MUCH LEFT PREVIOUS FORECAST ALONE. STILL APPEARS WEAK FRONTAL SYSTEM WILL BRING SOME SCATTERED SHOWERS LATE FRIDAY INTO SATURDAY AND AGAIN SUNDAY NIGHT INTO MONDAY. MIGHT BE ABLE TO SQUEEZE OUT A MAINLY DRY DAY ON SUNDAY...BUT MUCH TOO EARLY TO BANK ON THAT. SOMEWHAT MORE CONFIDENT ON TEMPERATURES WITH READING CONTINUING TO SLIDE TO BELOW NORMAL VALUES WITH DAYTIME HIGHS BOTH SATURDAY AND SUNDAY IN THE 45 TO 50 DEGREE RANGE. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1230 PM CDT MON OCT 14 2013 VFR CONDITIONS TO PERSIST THROUGH THE EVENING...THOUGH MID AND HIGH CLOUDS WILL BE INCREASING FROM THE WEST OVER THIS TIME. THE LATEST GUIDANCE SUGGESTS RAIN WILL BEGIN MOVING INTO CENTRAL AND NORTH-CENTRAL WISCONSIN AFTER 09Z TONIGHT...AND THEN INTO EASTERN WISCONSIN BY AROUND 12Z. AS THE RAIN ARRIVES...GUIDANCE AND UPSTREAM OBS SHOW CIGS/VSBYS FALLING TO IFR/MVFR LEVELS...WHICH WILL HANG AROUND THROUGH THE END OF THE TAF PERIOD. LOW LEVEL WIND SHEAR TO ALSO DEVELOP LATE TONIGHT AHEAD OF A SURFACE LOW. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ESB AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT MON OCT 14 2013 .UPDATE... ISSUED AT 745 AM CDT MON OCT 14 2013 THE FROST ADVISORY WILL BE ALLOWED TO EXPIRE AT 8 AM. WIDESPREAD FROST HAS OCCURRED OVER THE ADVISORY AREA WITH EARLY MORNING TEMPERATURES PLUMMETING INTO THE MID 20S TO LOWER 30S. TEMPERATURES ARE EXPECTED TO WARM TO ABOVE FREEZING THROUGH 9 AM. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 230 AM CDT MON OCT 14 2013 SHORTWAVE ENERGY WAS DRIVING THROUGH THE MEAN TROUGH OVER THE ROCKIES EARLY THIS MORNING...PER LATEST WATER VAPOR SATELLITE IMAGERY. THE TROUGH WILL LIFT NORTHEAST TODAY AS A 300 MB JET ROUNDS ITS BASE AND HEADS TOWARD THE GREAT LAKES. GOOD AGREEMENT BETWEEN THE GFS/NAM/ECMWF WITH PLACING THE 500 MB LOW OVER SOUTHERN MN BY 18Z TUE...MORE OR LESS VERTICALLY STACKED WITH THE ASSOCIATED SFC LOW AT THIS TIME. STRONG QG RESPONSE...DEEPER AND STRONGER OVER SOUTHERN MN/NORTHWEST WI FROM 06Z-18Z TUE. THERMODYNAMICS ARE EQUALLY HEFTY...WITH A STRONG PUSH OF 925-700 MB WARM AIR ADVECTION AS THE SYSTEM MOVES IN...ALONG WITH RISING AIR ALONG THE 290-305 K ISENTROPIC SFCS. THE LEFT EXIT REGION OF THE 300 MB JET WILL ENHANCE THE ALREADY APPRECIABLE LIFT...MOSTLY IN THE DEFORMATION REGION OF THE STORM SYSTEM. MEANWHILE...FRONTOGENETIC RESPONSE IS GOOD ALONG THE SYSTEM/S SOUTHWARD HANGING COLD FRONT...WITH A 50 KT LOW LEVEL JET SURGING MOISTURE NORTHWARD ALONG THE FRONT...THEN WRAPPED WESTWARD AROUND THE LOW. ITS GOING TO RAIN. MODELS IN GOOD AGREEMENT WITH PCPN ENCROACHING UPON AREAS WEST OF THE MISSISSIPPI LATE THIS EVENING...SPREADING INTO WESTERN WISCONSIN OVERNIGHT. THE FRONTAL/MOISTURE TRANSPORT BAND OF PCPN SHIFTS ACROSS EASTERN WI BY LATE MORNING WHILE THE DEFORMATION BAND NORTH-WEST OF THE SFC LOW HANGS FROM SOUTHERN MN TO ACROSS THE UP OF MICH. THIS REGION WILL SHIFT EASTWARD AND ACROSS THE FORECAST AREA FOR THE AFTERNOON THROUGH NIGHTTIME HOURS. COULD BE A BREAK IN THE PCPN WITH A DRY 850-700 MB PUNCH OF AIR POST THE SFC FRONT. WILL CONTINUE TO PLAY THIS TREND IN THE PCPN CHANCES. ON WED...A LINGERING WESTWARD EXTENDING SFC TROUGH AND A BIT OF UPPER LEVEL ENERGY COULD CONTINUE TO SCATTERED LIGHT RAIN SHOWERS FOR THE MORNING EAST OF THE MISSISSIPPI RIVER. .LONG TERM...(THURSDAY THROUGH SUNDAY) ISSUED AT 230 AM CDT MON OCT 14 2013 GFS/EC IN GOOD AGREEMENT WITH AN UPPER LEVEL LOW SETTING UP SHOP OVER HUDSON/S BAY FOR THE LATER HALF OF THE WEEK...WITH A TROUGH REESTABLISHING ITSELF OVER THE GREAT LAKES. LOCALLY...THIS PUTS THE REGION UNDER NORTHWEST FLOW THROUGH THE WEEKEND...WITH VARIOUS BITS OF UPPER LEVEL ENERGY AND LOW LEVEL COLD AIR ADVECTION. THIS WILL RESULT IN PERIODIC LIGHT RAIN CHANCES...ESPECIALLY ACROSS NORTHERN PORTIONS OF MN/WI. CHANCES WILL BE HIGHER WITH THE PASSAGE OF ANY SHORTWAVE TROUGH/SFC FRONT COMBO. NOTHING OVERLY DYNAMIC AT THIS TIME...AND CAN/T FERRET OUT A MORE LIKELY PERIOD THIS FAR OUT. WILL SIDE WITH CONSENSUS FOR PCPN CHANCES. 850 MB TEMPS WILL TUMBLE TO -6 C FOR THE WEEKEND...WITH ECMWF 850 MB TEMP ANOMALIES FROM -1 TO -1.5. ITS GOING TO BE A COOL LAST HALF OF THE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1242 PM CDT MON OCT 14 2013 A LOW PRESSURE SYSTEM...CURRENTLY LOCATED OVER EASTERN NEBRASKA... WILL MOVE NORTHEAST ACROSS WESTERN IOWA AND SOUTH CENTRAL MINNESOTA THROUGH TUESDAY MORNING. AS THIS LOW APPROACHES THE AREA OF BAND OF SHOWERS WILL MOVE INTO KRST AROUND 15.03Z AND KLSE AROUND 15.06Z. WITH DRY AIR IN PLACE ACROSS THE REGION...IT WILL TAKE ABOUT 3 HOURS BEFORE THE CEILINGS WILL BECOME IFR/MVFR. THE CEILINGS WILL THEN LIKELY STAY THERE THROUGH THE REMAINDER OF TUESDAY MORNING. EXPECT THE VISIBILITIES TO BECOME MVFR AT KRST ABOUT THE SAME TIME THAT THE CEILINGS BECOME IFR...BUT WAS NOT AS CONFIDENT TO DO THE SAME AT KLSE....SO LEFT THEM OUT FOR NOW. WHILE THE BAND OF PRECIPITATION WILL BE NARROW...THE MODELS CONTINUE TO STRUGGLE ON WHEN THIS PRECIPITATION MIGHT END. THE LATEST RAP SUGGESTS THAT THIS WOULD OCCUR AT KRST BY 10Z AT KRST AND 13Z AT KLSE. HOWEVER THE NMM AND ARW SHOW THAT THIS PRECIPITATION WILL CONTINUE THROUGH THE MORNING. SINCE IT WAS UNCLEAR...WENT WITH A COMPROMISE AND ENDED IT AROUND 15.14Z AT KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...WETENKAMP SHORT TERM...RIECK LONG TERM....RIECK AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1128 PM CDT SUN OCT 13 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND MONDAY ISSUED AT 227 PM CDT SUN OCT 13 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE HIGH PRESSURE SYSTEM GRADUALLY MOVING EAST OVER THE NORTHERN PLAINS TO MID-MISSISSIPPI VALLEY. LINGERING WEAK CYCLONIC FLOW AND THERMAL TROUGHING HAVE KEPT A STUBBORN STRATO-CU FIELD OVER THE NE THIRD OF THE STATE...THOUGH ITS GRADUALLY BREAKING UP. LOOKING UPSTREAM...MID AND HIGH CLOUDS ARE ADVANCING NE OVER THE PLAINS AHEAD OF THE NEXT STORM SYSTEM. SO WITH HIGH PRESSURE MOVING IN...FORECAST CONCERNS ARE CLOUDS...TEMPS AND FROST HEADLINES. TONIGHT...SURFACE HIGH PRESSURE WILL BE SETTLING ACROSS THE WESTERN GREAT LAKES REGION...PROVIDING MOSTLY CLEAR SKIES AND LIGHT WINDS. SHOULD SEE HIGH CIRRUS MOVE INTO NORTHERN WISCONSIN THIS EVENING...WHILE LIGHT EASTERLY FLOW WILL DEVELOP OVER THE LAKE MICHIGAN SHORELINE LATE. SOME CONCERN ABOUT LAKE CLOUDS MOVING INLAND THAT COULD MESS AROUND WITH FROST FORMATION OVER EAST-CENTRAL WISCONSIN. HOWEVER...THE EASTERLY FLOW WILL GENERALLY BE 5 KTS OR UNDER...AND LOCAL DATA SUGGESTS LAND BREEZES WILL DEVELOP THAT WILL KEEP LAKE INDUCED CLOUDS OFFSHORE. AS A RESULT...WILL LOWER TEMPS OVER EAST-CENTRAL WISCONSIN...WHERE LOCATIONS AWAY FROM LAKE MICHIGAN WILL LIKELY FALL INTO THE MIDDLE 30S. THESE CONDITIONS WILL LEAD TO THE POTENTIAL OF FROST SO WITH COLLAB FROM OTHER OFFICES...WILL HOIST A FROST ADVISORY EXCEPT FOR DOOR COUNTY. MONDAY...HIGH PRESSURE WILL REMAIN OVER THE AREA. IN ADDITION TO HIGH CLOUDS INCREASING FROM WEST TO EAST OVER THE AREA...EASTERLY WINDS STRENGTHEN SOME DURING THE MORNING...AND POSSIBLY ENOUGH TO PUSH A MID-LAKE CLOUD BAND INLAND. WILL INCREASE CLOUD COVER OVER EAST-CENTRAL WISCONSIN DURING THE MORNING. THINK THESE CLOUDS WILL GRADUALLY DISSIPATE DURING THE AFTERNOON...SO WILL CONTINUE TO SHOW MORE SUN EAST VERSUS WEST. HIGH TEMPS MAINLY IN THE MID TO UPPER 50S. .LONG TERM...MONDAY NIGHT THROUGH SUNDAY ISSUED AT 227 PM CDT SUN OCT 13 2013 PATTERN OVER CONUS FOR THE NEXT WEEK TO CONSIST OF STRONG UPPER RIDGE ALONG THE WEST COAST WITH A BROAD UPR TROF ACROSS THE CENTRAL U.S. UNSETTLED WEATHER EXPECTED INTO WEDNESDAY AS UPPER TROF/ASSOCIATED SFC LOW AND COLD FRONT MOVE THRU THE GREAT LAKES. PCPN CHANCES CONTINUE...ALBEIT LOWER POPS THROUGH THE REMAINDER OF THE PERIOD AS COOLER AIR ALOFT SETTLES OVER THE REGION AND A SECONDARY WEAK COLD FRONT/TROF MOVE THRU. TEMPS TO BE NEAR NORMAL THRU THU AND THEN FALL BELOW NORMAL BY THE END OF THE WEEK. PCPN CHANCES INCREASE THROUGH THE NIGHT MON AS WAA PATTERN SPREADS EAST OVER THE REGION. MODELS CONTINUE TO SHOW DRY LAYER IN MID LEVELS THROUGH MUCH OF THE NIGHT MON. HAVE SLOWED PCPN A BIT EARLY EVENING...THOUGH LEFT REST OF PREVIOUS FORECAST STAND...STAYING DRY OVER THE EAST. WIDESPREAD PCPN EXPECTED TUE INTO TUE EVENING AS SURFACE LOW MOVES THROUGH STATE. DEEPER MOISTURE STRIPPED OUT LATER TUE NIGHT/WED LEADING TO LOWER POPS OR LIGHT PCPN. STILL HAVE TIMING DIFFERENCE THROUGH MUCH OF THE EXTENDED...THUS HAVE LEANED TOWARDS GFS ENSEMBLE FORECAST. HAVE BUMPED WINDS UP ON LAKE/BAY THROUGH THE EXTENDED GIVEN COLD AIR MASS MOVING IN. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1127 PM CDT SUN OCT 13 2013 CLEAR SKIES AND MAYBE SOME PATCHY GROUND FOG EXPECTED IN MOST PLACES TONIGHT. SOME LAKE EFFECT CLOUDS MAY FORM NEAR LAKE MICHIGAN AND THE BAY TOWARDS MORNING. BEST GUESS IS THAT CLOUDS BASES WILL BE BETWEEN 2500 FT AND 3500FT. LAKE EFFECT CLOUDS MAY LINGER AT MTW/SUE/GRB/MNM/OCQ WITH JUST INCREASING HIGH CLOUDS ELSEWHERE. && .GRB WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 3 AM TO 8 AM CDT MONDAY FOR WIZ038-039- 048>050. && $$ SHORT TERM.....MPC LONG TERM......TE AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS RIVERTON WY
1120 PM MDT SUN OCT 13 2013 .UPDATE... INSERTED 06Z AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... /ISSUED 422 PM MDT SUN OCT 13 2013/ SHORT TERM...TONIGHT THROUGH MONDAY MAIN TROUGH AXIS IS LOOMING TO OUR WEST OVER IDAHO...NEVADA AND UTAH. THIS TROUGH WILL BE RESPONSIBLE FOR ACCUMULATING SNOW...MAINLY IN OUR MOUNTAINS...AS WELL AS THE LOWER ELEVATIONS OF JOHNSON COUNTY TONIGHT THROUGH MONDAY EVENING. CURRENTLY WE ARE UNDER THE SOUTHWEST UPPER DIFLUENT UPPER FLOW ASSOCIATED WITH THE LEFT FRONT QUAD OF THE JET WHICH IS RESPONSIBLE FOR LIGHTNING ALONG THE FAR WESTERN BORDER OF WYOMING FROM WEAK CONVECTIVE CELLS. THIS MORE CONVECTIVE ACTIVITY HAS REPLACED THE MORE STRATIFORM PRECIP ASSOCIATED WITH THE WEAK ISENTROPIC LIFT IN THE WEST. A CIRCULATION IS EVIDENT ON PIH RADAR IN EASTERN IDAHO JUST WEST OF THE CONVECTION WITH THE RUC INDICATING INCREASING INSTABILITY. HOWEVER...THE GFS...NAM AND THE ECMWF ALL AGREE ON KEEPING THE MAIN JET ENERGY WELL TO THE SOUTH TRACKING ACROSS THE 4 CORNERS AREA LATE TONIGHT WITH THE VORT ENERGY STRENGTHENING IN THE NORTHERN AND CENTRAL PLAINS MONDAY. THE SURFACE FLOW IS OUT OF THE NORTHEAST ATTM...EAST OF THE DIVIDE...BUT AT MAINLY LIGHT SPEEDS. ONCE THE MAIN LOW OVER NEBRASKA/SOUTH DAKOTA STARTS TO BOMB...THE NORTH WINDS EAST OF THE DIVIDE WILL STRENGTHEN AND THUS INCREASE UPSLOPE SNOWFALL POTENTIAL. THE GFS INDICATES 3 SEPARATE SUBTLE CIRCULATIONS AT 700MB THAT WILL TRACK EAST ACROSS VARIOUS PORTIONS OF WYOMING TONIGHT...NOT THE MOST ORGANIZED SYSTEM WITH ASSOCIATED Q VECTOR FORCING AND WEAK ISENTROPIC LIFT. WITH THE 700MB CIRCULATIONS TRACKING ACROSS OUR CWA...BUT WITH THE MAIN ENERGY WELL TO OUR SOUTH...THE THINKING WAS ADVISORY AMOUNTS OF SNOWFALL FOR MOST OF THE MOUNTAIN ZONES EAST OF THE DIVIDE...NAMELY THE WIND RIVER...ABSAROKA AND BIG HORN MOUNTAINS AS WELL AS CASPER MOUNTAIN. THE BIG HORNS AND CASPER MTN WILL LIKELY LAG BEHIND ROUGHLY SIX HOURS COMPARED TO THE WINDS AND THE ABSAROKAS. DECIDED TO ISSUE A WINTER STORM WARNING FOR THE BIG HORN MOUNTAINS TO ACKNOWLEDGE THE 30 TO 40 MPH WIND GUSTS...THE HIGH END SNOW ADVISORY AMOUNTS AND ALSO TAKING INTO ACCOUNT THE TIME OF YEAR AND ALL THE HUNTERS THAT WILL BE NEGOTIATING THE WINTER CONDITIONS. THE BULK OF THE COLDEST 700MB AIR WILL COME CLOSEST TO JOHNSON COUNTY WHERE ADVISORY SNOW AMOUNTS ARE INDICATED FOR THAT ZONE FOR MONDAY AND MONDAY EVENING. THE MOS GUIDANCE INDICATES ACCUMULATING SNOWFALL FOR BYG AND SHR BUT NONE FOR THE OTHER MOS GUIDANCE FORECAST POINTS WHERE 700MB TEMPS ARE PROGGED BY THE NAM TO BE -9.5C IN NORTHERN JOHNSON COUNTY 00Z TUESDAY. NOT ONLY IS ACCUMULATING SNOW EXPECTED FOR THE LOWER ELEVATIONS OF JOHNSON COUNTY BUT STRONG NORTH WINDS OF 30 TO 40 MPH WITH SOME GUSTS OF 50 MPH ARE EXPECTED THERE AS WELL ON MONDAY ONCE THE STORM BOMBS TO THE EAST. THE NIGHT SHIFT WILL NEED TO DECIDE WHETHER OR NOT THE LOWER ELEVATIONS OF JOHNSON COUNTY AND THE GREEN MTNS...FOR THAT MATTER...NEED A HILITE FOR MONDAY AND MONDAY EVENING. LONG TERM...MONDAY NIGHT THROUGH SUNDAY AFTER SOME LINGERING FLURRIES...MAINLY EAST OF THE DIVIDE...SURFACE HIGH PRESSURE WILL BEGIN TO BUILD OVER WYOMING LATE MONDAY NIGHT AND TUESDAY. THE WEST AND NORTH SHOULD CLEAR OUT FIRST...RESULTING IN A VERY CHILLY TUESDAY MORNING. LOW LEVEL CLOUDS COULD REMAIN OVER JOHNSON AND NATRONA COUNTIES EARLY TUESDAY MORNING BEFORE A CLEARING SKY. MOST OF THE FORECAST AREA WILL STILL SEE A SUNNY SKY BY TUESDAY AFTERNOON. NORTHWEST FLOW THEN SETS UP ALOFT OVER WYOMING. IT WILL BE DRY AND COLD TUESDAY NIGHT THROUGH WEDNESDAY NIGHT PER MODELS. FURTHER IN THE EXTENDED WILL HAVE TO WATCH FOR A FEW QUICK HITTING SHORTWAVES IN THIS NORTHWEST FLOW...BEGINNING EARLY THURSDAY. AS IT LOOKS NOW... WEST CENTRAL WYOMING WILL BE UNDER INFLUENCE OF THE DRIER NORTHERLY STREAM INTO NEXT WEEKEND. THE ECMWF IS MORE ROBUST WITH THESE EMBEDDED SHORTWAVES...BUT PREFER THE DRIER GFS FOR NOW. IF ANY AREA WERE TO SEE SOME SNOW SHOWERS IN THIS PATTERN...IT WOULD BE THE BIGHORN MOUNTAINS. THEREFORE...SLIGHTLY HIGHER POPS FOR BIGHORN MOUNTAINS THURSDAY AND FRIDAY. OTHERWISE...TEMPERATURES SHOULD BE NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AVIATION.../06Z ISSUANCE/ WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES UNSETTLED WEATHER WILL CONTINUE MONDAY WITH PERIODS OF MVFR/IFR CONDITIONS IN LOW CLOUDS AND SNOW SHOWERS. HOWEVER...MOST TERMINALS SHOULD SEE CEILINGS LIFT AT TIMES IN THE 035-050 KFT AGL RANGE. THE WORST CONDITIONS WILL PROBABLY OCCUR AT THE ROCK SPRINGS AND BIG PINEY TERMINALS. MOUNTAINS WILL BE OBSCURED WITH IFR CONDITIONS THROUGH MUCH IF NOT ALL OF THE FORECAST PERIOD. AVIATION CONDITIONS WILL GENERALLY BE WORSE EAST OF THE DIVIDE. EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES RAIN WILL CONTINUE TO CHANGE TO SNOW IN THE LOWER ELEVATIONS...AS A COLD FRONT SWEEPS SOUTHWARD...ALSO CHANGING SHOWERY PRECIP TO MORE STRATIFORM. MOST AREAS SHOULD CHANGE BY 14Z. WIDESPREAD IFR/MVFR CONDITIONS WILL OCCUR MONDAY IN SNOW AND LOW CLOUDS WITH WINDY NORTHERLY WINDS. THE WORST CONDITIONS WILL BE THROUGH 18Z TODAY. HOWEVER A CONTINUATION OF MVFR CONDITIONS IS LIKELY THROUGH TONIGHT...ESPECIALLY IN FAVORED UPSLOPE AREAS SUCH AS NEAR THE LANDER AND CASPER AREAS. MOUNTAINS WILL BE OBSCURED WITH LIFR CONDITIONS ACROSS MOUNTAIN PASSES. PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON ICING FORECASTS. FIRE WEATHER... IRE WEATHER WILL NOT BE A FACTOR IN THE NEXT DAY OR TWO DUE TO LOW PRESSURE OVER THE CENTRAL AND NORTHERN ROCKIES. THE LOW PRESSURE...AT THE SURFACE AND ALOFT...WILL RESULT IN AREAS OF SNOW. WINTER STORM WARNINGS AND ADVISORIES HAVE BEEN ISSUED FOR SOME OF THE WEST CENTRAL WYOMING MOUNTAIN RANGES. THIS SNOW WILL TAPER OFF BY MONDAY NIGHT. TUESDAY THROUGH WEDNESDAY WILL HAVE COOL TEMPERATURES AND VERY LITTLE WIND OR MIXING ACROSS THE REGION. && .RIW WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT MDT MONDAY NIGHT WYZ022. WINTER WEATHER ADVISORY UNTIL 6 PM MDT MONDAY WYZ002-015. WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT MDT MONDAY NIGHT WYZ008-009. WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO MIDNIGHT MDT MONDAY NIGHT WYZ010. WINTER WEATHER ADVISORY UNTIL 3 PM MDT MONDAY WYZ003. && $$ UPDATE...WM SHORT TERM...LIPSON LONG TERM...KPL AVIATION...WM FIRE WEATHER...KPL
AREA FORECAST DISCUSSION
NWS MIAMI FL
1253 AM EDT WED OCT 16 2013 .AVIATION... ALTHOUGH AN AREA OF WEAK LOW PRESSURE CONTINUES ACROSS THE NORTHERN BAHAMAS...SHOWERS ARE EXPECTED TO MAINLY REMAIN IN THE OFF SHORE ATLANTIC WATERS. MAINLY VFR CONDITIONS ARE EXPECTED EARLY THIS MORNING. PATCHY MORNING FOG IS POSSIBLE...BUT MAINLY IN THE INTERIOR. 60 && .PREV DISCUSSION... /ISSUED 1005 PM EDT TUE OCT 15 2013/ UPDATE... THE 00Z SOUNDING INDICATED A STABLE LOCAL ATMOSPHERE WITH A WELL PRONOUNCED LOW LEVEL INVERSION. A WEAK AREA OF LOW PRESSURE ACROSS THE BAHAMAS IS PRODUCING ISOLATED SHOWERS ACROSS THE OFF SHORE ATLANTIC WATERS...BUT UPPER LEVEL SUBSIDENCE ACROSS THE REGION IS SUPPRESSING ANY SUBSTANTIAL DEVELOPMENT OF THE SHOWERS AND MAINLY ISOLATED ACTIVITY IS EXPECTED ACROSS THE ATLANTIC WATERS TONIGHT. NO SIGNIFICANT CHANGES WERE REQUIRED TO THE CURRENT FORECAST PACKAGE. 60 PREV DISCUSSION... /ISSUED 824 PM EDT TUE OCT 15 2013/ AVIATION... LOW PRESSURE ACROSS THE BAHAMAS CONTINUES TO SPREAD MOISTURE WESTWARD AND INTO THE OFFSHORE ATLANTIC WATERS. ASSOCIATED SHRAS ARE EXPECTED TO STAY AWAY FROM THE EAST COAST SITES THROUGH THE NIGHT. LOCAL HI RES MODELS DEPICT A FEW OF THESE SHRAS MOVING CLOSER TO THE EAST COAST SITES DURING THE DAY TOMORROW. KEPT VCSH AFTER 14Z. WINDS SHOULD BE LIGHT OVERNIGHT WITH WEAK DRAINAGE AT KAPF. EAST-NORTHEASTERLY FLOW SHOULD PREVAIL AT THE EAST COAST SITES TOMORROW AT AROUND 10 KTS WITH A GULF BREEZE DEVELOPING AT KAPF. PREV DISCUSSION... /ISSUED 231 PM EDT TUE OCT 15 2013/ SHORT TERM (TONIGHT-THURSDAY NIGHT)... VERY PROGRESSIVE MID LATITUDE PATTERN TAKING SHAPE ACROSS NORTH AMERICA WITH TWO MAJOR MID/UPPER LEVEL TROUGHS MOVING ACROSS THE NORTHERN STATES THIS PERIOD. AT THE SAME TIME, A TROUGH HAS BEEN CUT OFF OVER THE ATLANTIC NORTH OF THE BAHAMAS WITH A RIDGE ACROSS THE GULF OF MEXICO. THE ATLANTIC TROUGH WILL DRIFT SOUTH OVER THE NEXT COUPLE OF DAYS AS A STRONG RIDGE AMPLIFIES OVER THE EASTERN PACIFIC FORCING THE GULF RIDGE TO EXPAND EAST AND THE ATLANTIC TROUGH GETS PINCHED OFF FROM THE NORTHERN STREAM TROUGHS. THE ATLANTIC TROUGH HAS IN TURN, INDUCED A WEAK SURFACE TROUGH ACROSS THE BAHAMAS IN THE VICINITY OF NASSAU AND ANDROS ISLAND. THIS IS CLEARLY EVIDENT ON VISIBLE SATELLITE AND IT APPEARS TO BE DRIFTING TO THE WEST IN AN OTHERWISE WEAK SURFACE PRESSURE PATTERN IN THE AREA SURROUNDING SOUTH FLORIDA. I MENTION ALL OF THIS AS THE NAM HAS CAPTURED THIS SURFACE FEATURE MORE SO THAN THE GFS OR THE ECMWF FOR THAT MATTER. THE PROBLEM FOR AT LEAST THE FIRST PERIOD OR TWO WITH THIS FORECAST PACKAGE IS HOW MUCH AFFECT THIS TROUGH WILL HAVE ON SOUTH FLORIDA. THERE ALREADY ARE SCATTERED SHOWERS OVER THE FAR OFFSHORE ATLANTIC WATERS WITH A COUNTERCLOCKWISE MOVEMENT TO THEM AROUND THE LOWER PRESSURE. HOWEVER, THE NAM IS NOTED FOR SUFFERING FROM MESOSCALE BIAS BUT SOMETIMES PICKS UP ON THESE SMALL SCALE FEATURES WITH ITS FINER RESOLUTION BETTER THAN THE GFS. THE LATEST RUN OF THE HIGH RESOLUTION HRRR ALSO SHOWS AN INCREASE IN SHOWER ACTIVITY APPROACHING THE SOUTHEAST FLORIDA COAST LATER TONIGHT. FOR ALL OF THESE REASONS, WILL INTRODUCE SCATTERED POPS FOR THE THE SOUTHEAST COASTAL REGION FOR LATE TONIGHT AND CONTINUING INTO EARLY WEDNESDAY. IN ADDITION, DUE TO ITS MESOSCALE BIAS WILL NOT GO AS BULLISH AS THE MET GUIDANCE BUT WILL CERTAINLY GO ABOVE THE MAV NUMBERS. THE GULF OF MEXICO RIDGE WILL CONTINUE TO BUILD EAST THROUGH THURSDAY NIGHT WHICH SHOULD MAINTAIN A SUBSIDENCE CAP ACROSS THE REGION. THE NAM CONTINUES HIGH MOISTURE OVER SOUTH FLORIDA THROUGH THURSDAY NIGHT SHOWING PWAT IN THE RANGE OF 1.6-1.9 INCHES. THIS IS NO DOUBT IS OVERDONE CONSIDERING THE RIDGE SHOULD MAINTAIN A SUBSIDENCE CAP OVER SOUTH FLORIDA AND WILL REDUCE THE POPS CLOSER TO THE MAV GUIDANCE BUT AGAIN THE MAV MIGHT BE TOO LOW. ON A SIDE NOTE, THIS IS THE TIME OF THE YEAR OF ASTRONOMICAL HIGH TIDES AND THE HIGHEST TIDES ALONG THE ATLANTIC COAST WILL BE PEAKING BETWEEN THIS EVENING THROUGH THE UPCOMING WEEKEND. THIS ALSO COINCIDES WITH THE FULL MOON WHICH IS TO OCCUR ON FRIDAY. THERE WILL THEREFORE BE AN INCREASE IN SOME NUISANCE TYPE URBAN STREET FLOODING AT TIMES OF HIGH TIDE OVER THE NEXT SEVERAL DAYS POSSIBLY INTO THE EARLY NEXT WEEK ESPECIALLY ON THE BARRIER ISLANDS SUCH AS MIAMI BEACH. THE HIGH TIDES THROUGH THE END OF THIS WEEK WILL BE OCCURRING IN THE EVENING AND AGAIN EARLY IN THE MORNING. LONG TERM (FRIDAY-TUESDAY)... THE GULF RIDGE WILL MAINTAIN A PRESENCE ACROSS SOUTH FLORIDA THROUGH THE EXTENDED PERIOD. FOR THIS REASON, A COLD FRONT THAT WILL MOVE INTO THE SOUTH GULF COASTAL STATES EARLY FRIDAY, WILL STALL AND REMAIN NEARLY STATIONARY THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THIS WILL MAINTAIN A LOW LEVEL EASTERLY FLOW BUT WITH MOISTURE CONTENT REMAINING LOW. BUT STILL, THERE COULD BE SOME ISOLATED SHOWERS ESPECIALLY ALONG THE EAST COAST. MARINE... TRANQUIL WIND AND SEAS WILL CONTINUE THROUGH THE PERIOD WITH SEAS 4 FEET OR LESS. THERE COULD BE AN INCREASE IN SHOWER ACTIVITY OVER THE ATLANTIC WATERS THIS EVENING SPREADING TOWARDS THE SOUTHEAST COAST INCLUDING BISCAYNE BAY AFTER MIDNIGHT DUE TO AN APPROACHING SURFACE TROUGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 73 87 74 / 20 20 10 10 FORT LAUDERDALE 85 74 85 75 / 20 20 20 10 MIAMI 86 75 87 75 / 20 20 20 10 NAPLES 88 72 88 72 / 20 10 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...54/BNB AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 AM CDT WED OCT 16 2013 .DISCUSSION... 931 PM CDT ONLY REAL CHANGES TO THE GOING FORECAST WERE TO ADJUST HOURLY SKY TRENDS TO BETTER MATCH SATELLITE AND SHORT TERM GUIDANCE TRENDS IN SPREADING IN THE STRATUS DECK FROM THE NORTHWEST TONIGHT AND BEEFED UP SKY COVER A BIT INTO WEDNESDAY MORNING. COULD BE SOME DRIZZLE...ESPECIALLY NORTHWEST CWA LATE TONIGHT POTENTIALLY SPREADING EAST INTO NORTHEAST ILLINOIS WEDNESDAY MORNING WITHIN THE STRATUS DECK. THINKING THAT GOING POPS FOR TOMORROW LATE MORNING AND AFTERNOON ARE LIKELY TOO HIGH WITH EXTENSIVE CLOUD COVER LIKELY TO LIMIT HEATING/DESTABILIZATION WITH LOW INVERSION HEIGHTS MAKING SHOWERS LOOK FAIRLY UNLIKELY. IF ANYTHING WOULD APPEAR TO BE MORE OF A STRATUS/MORNING DRIZZLE TYPE SCENARIO WEDNESDAY MORNING WITH DRIZZLE TAPERING OFF IN THE AFTERNOON. GIVEN LOW CONFIDENCE HAVE OPTED TO LET GOING FORECAST POPS RIDE FOR WEDNESDAY AND WILL BRIEF ONCOMING NIGHT SHIFT AND ALLOW THEM TO GET A LOOK AT FULL SUITE OF 00Z DATA BEFORE MAKING ANY BIG ADJUSTMENTS. STRATUS DECK LIKELY TO RESULT IN VERY LITTLE HEATING WEDNESDAY AND GOING FORECAST HIGHS BELOW GUIDANCE LOOKS LIKE A GOOD TREND AND EVEN THOSE HIGHS COULD END UP A TAD WARM WHERE SUN DOESN`T BREAK OUT AT ALL. IZZI //PREV DISCUSSION... 307 PM CDT THE FORECAST CONCERNS ARE CENTERED ON TEMPERATURES FOR MUCH OF THE FORECAST...WITH CLOUD COVER BEING KEY. SMALL BUT FREQUENT CHANCES OF SHOWERS EXIST IN THE FORECAST...ESPECIALLY IN THE EXTENDED...AND ALSO WERE A FOCUS TODAY. SYNOPSIS...THE CLOSED UPPER LOW ACROSS THE UPPER MISSISSIPPI VALLEY IS BEGINNING TO GRADUALLY SHEAR AS IT MOVES NORTHEAST...WITH ANOTHER WELL-DEFINED CLOSED LOW ACROSS THE INTERMOUNTAIN WEST THAT WILL BRING A CHANCE FOR SHOWERS ON THU. AT THE SURFACE...1005MB LOW NEAR THE TWIN CITIES IS MOVING NORTHEAST WITH AN ASSOCIATED COLD FRONT...NOT FAR BEHIND THE LEADING EDGE OF THE SYSTEM DRY SLOT...PROGRESSING EASTWARD ACROSS NORTHWEST IL. THIS WILL LIKELY ALLOW MANY AREAS TO EXPERIENCE SUNSHINE FOR ONE TO TWO HOURS PRIOR TO SUNDOWN. THE MAIN AXIS OF SHOWERS THAT PASSED TODAY ASSOCIATED WITH THE MOISTURE TRANSPORT MAX ALONG THE WARM CONVEYOR BELT WILL CONTINUE TO SHIFT EAST...WITH A SMALL CHANCE FOR REDEVELOPING SHOWERS ALONG THE FRONT. THE VISIBLE SATELLITE HAS REVEALS A NARROW AXIS OF CONVERGENCE ALONG THE FRONT BUT THAT HAS SHOWN NO TREND FOR INCREASE...AND DIAGNOSTIC SOUNDINGS ADAPTED FOR SURFACE T/TDS INDICATE MAYBE 100-200 J/KG OF SBCAPE. CONTINUE SMALL POPS FOR THIS FEATURE UNTIL IT PASSES. TONIGHT AND WEDNESDAY...THE COLD FRONT WILL LEAD TO A QUICK DROP IN TEMPS AND EVEN A MORE RAPID FALL IN DEW POINTS. THE DRY SLOT AND ASSOCIATED SUPPRESSION...ALONG WITH STRONG SOUTHWEST WINDS IN THE CLOUD BEARING LAYER...SHOULD HELP TO SCOOT THE LOW CLOUDS EAST FOR MUCH OF THE EVE. WRAPAROUND CLOUDS ARE EXPECTED TO CREEP THEIR WAY IN FROM THE NORTHWEST ACROSS THE CWA OVERNIGHT AND EARLY WED MORNING. NAM AND NCEP WRF RH AND CONDENSATE FIELDS ARE IN STRONG AGREEMENT WITH THIS AND IT LINES UP WELL WITH CAA IN THE 850-925MB LAYER FOR STRATOCU. THE PATTERN IS FAVORABLE FOR THESE CLOUDS TO PREVAIL MUCH OF WED IF NOT A GOOD PART OF WED EVE...AND HAVE EXTENDED FURTHER IN FORECAST AND LONGER THAN WHAT GUIDANCE WOULD OUTRIGHT INDICATE. MID-LEVEL VORT AND COLD POCKET ALOFT WILL LIKELY BE ENOUGH TO GENERATE SCATTERED SHOWERS...ESPECIALLY IN WI...AND HAVE CONTINUED THE CHANCES ACROSS AREAS MAINLY NORTH OF I-80 ON WEDNESDAY. TEMPERATURES WILL BE STUNTED CONSIDERABLY BY THE CLOUDS AND EXPECT LITTLE RANGE BETWEEN MORNING STARTING VALUES AND DAYTIME MAXS. HAVE HIGHS MAINLY IN THE MID 50S BUT LOWER 50S CERTAINLY COULD MATERIALIZE. THURSDAY...UPPER LOW OVER THE INTERMOUNTAIN WEST BECOMES A PROGRESSIVE WAVE IN GUIDANCE SOLUTIONS INTO CENTRAL IL BY THU MORNING/EARLY AFTERNOON. HAVE LEANED TOWARD THE NAM AND EC WITH THIS WHICH ARE BOTH SLIGHTLY DEEPER AND FURTHER NORTH WITH ITS PATH...WHICH FAVOR SHOWER CHANCES OVER MORE OF THE CWA. HAVE INCREASED POPS WITH THIS VORT PASSAGE. TEMPS ON THU LOOK TO BE SLIGHTLY WARMER THAN WED...BUT CLOUDS AND POTENTIALLY SHOWERS WILL KEEP READINGS IN THE 50S. FRIDAY AND BEYOND...A LONG WAVE TROUGH PROGRESSIVELY ESTABLISHES ITSELF ACROSS CENTRAL NORTH AMERICA DURING THIS PERIOD WITH MULTIPLE SHORTWAVES WITHIN THE FLOW...WHICH LOOK TO OVERALL LOWER THE THICKNESSES AND TEMPERATURES ALOFT SLOWLY. THIS SHOULD REFLECT ITSELF IN SURFACE TEMPERATURES...ESPECIALLY HIGHS...BUT IT IS BECOMING MORE MUDDY. DURING SAT AND SUN CONFIDENCE IS ESPECIALLY LOW AS THE PAST TWO RUNS OF THE EC DO WANT TO SHOW A MORE ROBUST WARM SECTOR WITH A LOW IN THE NW FLOW...AND THAT INFRINGES INTO THE CWA ON SUN. THE 850MB TEMPS CLIMB TO 8C IN THE SOUTHERN CWA DURING THAT TIME...WHILE THE GEM AND GFS IN THAT PERIOD BASICALLY KEEP READINGS AT 0C OR BELOW. CERTAINLY LOOKS LIKE PERIODS OF CLOUDS FROM FRIDAY INTO EARLY NEXT WEEK THAT WILL BE A LARGER PLAYER IN TEMPS...ESPECIALLY MINS. SO OVERALL MANY PERIODS WITH CHANCE POPS...BUT THOSE WILL LIKELY BECOME BETTER DEFINED IN TIME. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS OVERSPREADING THE AREA OVERNIGHT...POTENTIALLY DROPPING NEAR OR TO IFR. BMD //DISCUSSION...UPDATED 06Z... LOW PRESSURE LIES OVER NORTHERN LAKE MICHIGAN TONIGHT WITH A SECONDARY FRONT TRAILING TO THE WSW ACROSS WISCONSIN INTO CENTRAL IOWA. A BROAD MVFR/IFR STRATUS DECK SPANS THE AREA OF LOW PRESSURE AND TRAILING FRONTAL TROUGH...AND IS GRADUALLY SPREADING EAST...REACHING THE ROCKFORD TERMINALS SHORTLY...AND THE CHICAGO TERMINALS LATE TONIGHT. LEADING EDGE OF THE STRATUS IS VFR BUT THEN DROPS TO MVFR SHORTLY THEREAFTER. CYCLONIC FLOW IS IN PLACE THROUGH THE DAY TOMORROW AND SHOULD RESULT IN LITTLE IF ANY IMPROVEMENT UNTIL AROUND 06Z THURSDAY WHEN FLOW BECOMES NEUTRAL...THAN ANTICYCLONIC. IN ADDITION TO THE LOW CIGS...AN UPPER LEVEL WAVE PASSING OVER THE AREA IN THE AFTERNOON MAY LEAD TO SOME PATCHY DRIZZLE. BMD //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN CIGS DROPPING TO MVFR...MEDIUM TO HIGH CONFIDENCE IN TIMING. LOW CONFIDENCE IN IFR AT THIS TIME. * MEDIUM CONFIDENCE IN WIND SPEED...MEDIUM TO HIGH CONFIDENCE IN DIRECTION. BMD //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... * THURSDAY...CHANCE OF SHRA. * FRIDAY...DRY/VFR. * SATURDAY...SLIGHT CHANCE OF SHRA. * SUNDAY...DRY/VFR. * MONDAY...CHANCE OF SHRA. && .MARINE... 258 AM CDT LOW PRESSURE LIES OVER NORTHERN LAKE MICHIGAN THIS MORNING WITH A TRAILING COLD FRONT STRETCHING WEST ACROSS WISCONSIN INTO IOWA. WINDS ARE STRONGEST ACROSS THE SOUTHERN HALF OF THE LAKE WHERE 30 KTS ARE EXPECTED TO CONTINUE...THEN SHOULD BEGIN TO TAPER THIS AFTERNOON. A SMALL CRAFT ADVISORY WILL BE HOISTED FOR THE INDIANA NEARSHORE WATERS EAST OF BURNS HARBOR THROUGH LATE THIS EVENING. STRONGER WINDS ARE EXPECTED LATE THIS MORNING AND EARLY AFTERNOON ACROSS THE NORTHERN HALF OF THE LAKE AS THE COLD FRONT PUSHES ACROSS ALLOWING WINDS TO INCREASE WITH 30 KT GUSTS EXPECTED. WINDS WILL TAPER ACROSS THE ENTIRE LATE TONIGHT AS ANOTHER TROUGH DROPS INTO THE WESTERN LAKES REGION ALLOWING THE GRADIENT TO WEAKEN. WINDS BEGIN TO INCREASE AGAIN ON SATURDAY AS ANOTHER LOW DROPS SOUTHEAST ACROSS THE CANADIAN PRAIRIES THEN PIVOTS EAST ACROSS THE NORTHERN LAKES REGION. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion National Weather Service Lincoln IL 244 AM CDT Wed Oct 16 2013 .DISCUSSION... ISSUED 243 AM CDT Wed Oct 16 2013 Latest surface map shows low pressure over the eastern part of the Michigan Upper Peninsula. The cold front extends southwest, and shows up as a narrow fine line through extreme southwest Indiana per radar imagery from the Evansville radar. Narrow clear slot just west of the Illinois River was about to be overtaken by a large stratocumulus deck from the northwest, and excessive mid and high clouds have been streaming northeast along the front across most of the forecast area. Main concern in the short term is with trying to time any cloud breakup today, followed by rain chances late tonight and early Thursday. Longer range issues focus on early weekend storm system and the cool weather trend which will last much of the forecast period. SHORT TERM...Today through Thursday... Latest RAP model guidance showing the mid/high clouds shifting south toward the Ohio Valley later today, as the stratocumulus pushes south of the I-72 corridor, although the NAM shows some decent break up by late morning. Given the expansive nature of the clouds, stretching all the way into northern Minnesota, will go with the more pessimistic route and keep skies mostly cloudy across the central and northern CWA today, with a bit of sunshine over the south. Went a couple degrees below the MOS guidance for highs, but this may need to be adjusted downward later if we are unable to get any breaks to develop. Shortwave currently near the 4 Corners region will zip eastward later today. 00Z model guidance closes this off as it reaches the Iowa/Illinois border toward sunrise Thursday, but ranges quite a bit in terms of any precipitation over our area. NAM is nearly dry with most of the precip near the remains of the earlier frontal boundary south of the Ohio River, while the GFS has a narrow rain axis just east of I-55. The ECMWF and Canadian models are much more bullish with widespread showers. Currently leaning toward more of the GFS solution but a bit more widespread with the showers Thursday morning, fairly similar in coverage to the earlier grids. However, am thinking that much of this will be out of the area by early afternoon, although some slight chance PoP`s will be in the afternoon forecast across the east. LONG TERM...Friday through Tuesday... A deepening upper trough over the central U.S. will be the main player this weekend, as a wedge of colder air drops southward from Canada. Some potential exists for light rain Friday night or early Saturday as the trough axis starts to shift eastward, but will maintain 20% PoP`s at this time. Some frost potential for Saturday night as winds lighten and temperatures fall into the upper 30s over the northern half of the CWA. Going into early next week, periodic lobes of energy will drop southward across the Midwest. The latest ECMWF remains quite chilly similar to the past couple runs, with 850 mb temperatures falling to around -5C by midweek, although the GFS is several degrees warmer. For now, have not strayed too far from the guidance, which keeps temperatures fairly similar throughout the period. Geelhart && .AVIATION... ISSUED 1159 PM CDT Tue Oct 15 2013 VFR conditions prevail across the central Illinois terminals at the moment, with westerly winds in the wake of the today`s cold front. Wrap around cloud cover, with cigs ranging in height from VFR to IFR, is spreading toward the area. The models are having trouble with how quickly these clouds should arrive, and satellite extrapolation is likely to be the best estimation at this point. For now, have kept MVFR cigs restricted to KPIA and KBMI, with VFR cigs elsewhere. Cigs should rise to VFR area-wide by the end of the 06Z TAF valid time. Bak && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1213 AM CDT Wed Oct 16 2013 ...Updated synopsis and aviation discussion... .SYNOPSIS... ISSUED AT 1210 AM CDT WED OCT 16 2013 At 00z Wednesday -22c 500mb low was located near the four corners region. This was near the based of an upper level trough that extended from the southwest United States to the western Great Lakes. A 500mb ridge axis extended from south central Canada into the Pacific Northwest. At the 700mb level temperatures this morning across the central plains ranged from -10c at North Platte to -1c at Dodge City to +3c at Amarillo. At the 850mb level a pools of higher dewpoints were observed across southern Nebraska and northern Kansas with temperatures ranging from +4c at Dodge City to -1c at North Platte and Omaha. Satellite loop also indicating some lower cloud cover was occurring in this area of higher 850mb dewpoints earlier this morning with Goodland reporting a cloud bases at 3600ft and Hays reporting clouds at 4100ft. At the surface an area of high pressure was located over southeast Wyoming with light winds near the surface ridge axis that extending southeast of the high into western Kansas. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 153 PM CDT TUE OCT 15 2013 To start off with, I deliberated over low temperatures quite a bit for tonight, and the resultant freeze and frost hazards. Model guidance varies quite a bit, and this difference seems to be centered around how fast some mid and high clouds will intrude. Have settled upon using the HRRR and RUC models, which are a bit cooler than then NAM, ECMWF, and GFS models. In the end, there could be a small area that freezes tonight in our northwest zones, namely Trego, Ellis, Scott, Lane and Ness counties, where a freeze warning will be posted from 4 am to 9 am CDT. The 32F degree mark may be tricky in Scott county, if the mid level clouds get there before the diurnal cooling off occurs, they may hit 33F or 34F very briefly around 09-10Z. To the south, surrounding the Freeze Warning, mid 30s seem likely and a frost advisory is in place from 4 am to 9 am CDT, with widespread frost mentioned. Even one more tier of counties southward will have patchy frost mentioned late, but without an advisory. Down along most of the Oklahoma state boundary, clouds will be entering there sooner, and thus lows in the upper 30s will extend along most of that stretch. An upper wave, open in nature, will cross from New Mexico into southeast Kansas on Wednesday. The upper synoptic lift may be just enough to kick off a few rain showers across our southern half of the CWA, but only slight chances seem justified since no surface boundary is present, and the lower layers will be cool. With clouds, some scattered showers, and cold air advection, max temps will struggle to get out of the 50s. Current forecast max temps range from 57F in Syracuse, to 60F in Medicine Lodge. I did not change the forecast highs, as they seemed reasonable. The other weather parameter worth noting is winds will not be too strong, as they have been of late. The high pressure will produce northwest winds around 10 mph in the morning, which will shift to the west by afternoon, still blow in the 10 to 15 mph range. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 316 PM CDT TUE OCT 15 2013 Relatively dry and sunny conditions are expected Thursday due to transient mid level shortwave ridging. Cold temperatures in the mid to upper 30`s are most likely during the morning while abundant insolation should allow warming into the 60`s by early afternoon. a sharp mid to upper level baroclinic zone associated with a strongly positively tilted trough and 300 mb level polar will jet have create sensible weather impacts for Friday. As the upper trough approaches and sharpens by Friday morning, the mid level baroclinic zone will strengthen causing frontogenesis and associated lift ageostrophic lifting. GFS is very similar to the ECMWF with respect to most mass fields with this system, and shows a continuously sloping intense frontogenetic profile from above 850 mb level near medicine lodge to near 500 mb across NW Kansas. This cold system aloft appears warm enough in the boundary layer to expect phase change to all rain at the surface. GFS and GEM are the coldest of the models, only allowing for temperatures to reach the upper 40`s across western Kansas by the afternoon. Precipitation chances have been increased to the likely category for Friday morning with a rapid tapering in the afternoon as the upper trough transitions to a subsident northwest flow across central Kansas by Friday night. Saturday morning will have potential to be cold again (even with frost) if winds and clearing conditions are favorable, but yet uncertain considering it is still at a 96 hour forecast timestep. The remainder of the forecast period through early next week is for and only slowly moderating surface temperatures toward normal for mid October, as northwest flow aloft becomes established aloft and high pressure dominates the central Rockies into the southern plains. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) ISSUED AT 1210 AM CDT WED OCT 16 2013 00Z Model runs continue to indicate increasing clouds across western Kansas overnight. Latest bufr soundings suggest cloud bases will between 3000ft and 4000ft AGL at HYS with 5000ft to 8000ft ft AGL at DDC and GCK. These VFR cigs are forecast to linger across western Kansas through late day as an upper level trough moves east across the central high plains. Northwest winds at 10kts or less will gradually back to the west by evening as an area of high pressure at the surface moves across western Kansas. && .PRELIMINARY POINT TEMPS/POPS... DDC 36 65 39 50 / 10 10 40 70 GCK 34 64 39 51 / 10 10 40 70 EHA 38 64 37 50 / 0 10 30 60 LBL 36 66 39 51 / 0 10 40 70 HYS 35 63 39 52 / 10 10 30 60 P28 38 67 42 54 / 10 0 40 70 && .DDC WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY from 4 AM CDT /3 AM MDT/ to 9 AM CDT /8 AM MDT/ this morning FOR KSZ046-061>065-074>079. FREEZE WARNING from 4 AM to 9 AM CDT this morning FOR KSZ030-031- 043>045. && $$ SYNOPSIS...Burgert SHORT TERM...Burke LONG TERM...Russell AVIATION...Burgert
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
529 AM EDT WED OCT 16 2013 .SYNOPSIS... A STALLED FRONT TO OUR SOUTH WILL GRADUALLY RETURN NORTH AS A WARM FRONT LATE TONIGHT AND WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES WEDNESDAY NIGHT THEN CROSS THE AREA ON THURSDAY. WEAK LOW PRESSURE CROSSES THE AREA FRIDAY AND AGAIN ON SUNDAY BRINGING WIDESPREAD SHOWERS TO THE REGION. A WARM FRONT APPROACHES ON MONDAY WHILE HIGH PRESSURE TRIES TO BUILD IN FROM THE SOUTH. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...MINOR CHANGES TO ACCOUNT FOR CURRENT OBSERVATIONAL TRENDS. PREVIOUS DISCUSSION...WARM FNT LIFTING INTO THE REGION WILL BRING A DREARY START TO THE DAY. WEAK ONSHORE FLOW AND NEARLY SATURATED LOW LVLS WILL BRING STRATUS INTO COASTAL AREAS EARLY. WEAK WAA ALOFT WILL PROVIDE ENOUGH LIFT FOR SOME DZ IN THESE AREAS THRU SUNRISE. DAYTIME HEATING WILL EVENTUALLY HELP LIFT AND SCATTER OUT THE LOW LVLS CLOUDS...LEAVING MOSTLY HIGH AND MID LVL OVERCAST. ENOUGH PEEKS OF SUN AND INSOLATION WILL HELP TEMPS INTO THE LOW TO MID 60S. WEAK LOW PRES SPINNING OUT IN THE ATLANTIC WILL DRIFT NWD THRU THE DAY...AND MAY BACK SOME SHRA TOWARDS THE MIDCOAST. HAVE SOME LOW POP FOR THE AFTERNOON THERE...WHILE GRADUALLY INCREASING POP FROM THE W AS COLD FNT APPROACHES LATE IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... EXPECT THAT MOST OF THE SHRA HOLD OFF UNTIL AFTER 00Z IN THE W...AND THIS IS SUPPORTED BY THE LATEST RUNS OF THE HRRR AND SPC WRF. LOW PRES IS NOT REALLY DEEPENING...AS PARENT S/WV IS SHEARING OUT AND LIFTING QUICKLY NEWD WITH TIME. AS SUCH...NOT SEEING MUCH MECHANISM OUT THERE FOR WIDESPREAD RNFL. TRENDING POP DOWNWARDS EXCEPT IN THE MTNS...WHERE OROGRAPHIC LIFTING AND PROXIMITY TO FORCING WILL SUPPORT GREATER COVERAGE OF SHRA. WITH CLOUDS AND PCPN AROUND THE AREA...LOW TEMPS WILL BE QUITE MILD FOR THIS TIME OF YEAR. FNT QUICKLY CROSSING THE AREA EARLY THU...AS S/WV TROF AXIS PASSES E. S/WV RIDGING FOLLOWS IN ITS WAKE...SO DOWNSLOPING AND DRYING ALOFT SHOULD CLEAR OUT SHRA AND HELP TO BREAK UP CLOUDS LATE IN THE DAY. TEMPS SHOULD CLIMB WELL INTO THE 60S DURING THE DAY...WITH SRN NH AND SWRN ME MAKING A RUN INTO THE 70S WITH ENOUGH SUN. TRAILING S/WV LIFTING OUT OF THE OH RIVER VALLEY MAY SPREAD CLOUDS BACK INTO SWRN ZONES LATE IN THE DAY THU. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A MORE ACTIVE PATTERN WILL DEVELOP OVER THE REGION AS WE END OUT THE WORK WEEK. AN AREA OF LOW PRESSURE WILL RAPIDLY CROSS THE AREA THURSDAY NIGHT INTO EARLY FRIDAY MORNING. THIS WILL BRING MORE PERSISTENT SHOWERS TO THE REGION MAINLY THURSDAY NIGHT...HOWEVER THE PRECIPITATION MAY LINGER FOR A COUPLE HOURS FRIDAY MORNING. MODELS HAVE COME INTO BETTER ALIGNMENT WITH THE TIMING OF THIS SYSTEM. A WEAK RIDGE OF HIGH PRESSURE WILL BRING DRIER AIR TO THE REGION FRIDAY AFTERNOON AND FRIDAY NIGHT. OVER THE WEEKEND...CYCLONIC FLOW ALOFT WILL ALLOW FOR SCATTERED SHOWER ACTIVITY...FOLLOWED BY A REINFORCING COLD FRONT SUNDAY NIGHT. HIGH PRESSURE WILL BUILD FOR MONDAY...BUT TEMPS WILL REMAIN NEAR OR BELOW NORMAL FOR THIS TIME OF THE YEAR AS A WARM FRONT APPROACHES FROM THE WEST NEXT TUESDAY. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...AREAS OF IFR OR LOWER THIS MORNING IN COASTAL STRATUS. CONDITIONS WILL IMPROVE TO VFR TODAY...BEFORE MVFR CIGS MOVE IN FROM THE W AS COLD FNT APPROACHES THE REGION. SCT SHRA MAY MOVE INTO THE CT RIVER VALLEY AFTER 00Z. LONG TERM...VFR CONDITIONS WITH AREAS OF MVFR IN SCATTERED SHOWERS FRIDAY AFTERNOON THROUGH SUNDAY NIGHT. MORE PERSISTENT SHOWERS ARE LIKELY THURSDAY NIGHT INTO EARLY FRIDAY MORNING WITH IFR CONDITIONS AT TIMES. && .MARINE... SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA THRESHOLDS. LONG TERM...WINDS AND WAVES SHOULD REMAIN BELOW SMALL CRAFT CRITERIA WITH SEVERAL DISTURBANCES CROSSING THE WATERS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ LEGRO/JC
AREA FORECAST DISCUSSION
NWS GRAY ME
237 AM EDT WED OCT 16 2013 .SYNOPSIS... A STALLED FRONT TO OUR SOUTH WILL GRADUALLY RETURN NORTH AS A WARM FRONT LATE TONIGHT AND WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES WEDNESDAY NIGHT THEN CROSS THE AREA ON THURSDAY. WEAK LOW PRESSURE CROSSES THE AREA FRIDAY AND AGAIN ON SUNDAY BRINGING WIDESPREAD SHOWERS TO THE REGION. A WARM FRONT APPROACHES ON MONDAY WHILE HIGH PRESSURE TRIES TO BUILD IN FROM THE SOUTH. && .NEAR TERM /THROUGH TODAY/... WARM FNT LIFTING INTO THE REGION WILL BRING A DREARY START TO THE DAY. WEAK ONSHORE FLOW AND NEARLY SATURATED LOW LVLS WILL BRING STRATUS INTO COASTAL AREAS EARLY. WEAK WAA ALOFT WILL PROVIDE ENOUGH LIFT FOR SOME DZ IN THESE AREAS THRU SUNRISE. DAYTIME HEATING WILL EVENTUALLY HELP LIFT AND SCATTER OUT THE LOW LVLS CLOUDS...LEAVING MOSTLY HIGH AND MID LVL OVERCAST. ENOUGH PEEKS OF SUN AND INSOLATION WILL HELP TEMPS INTO THE LOW TO MID 60S. WEAK LOW PRES SPINNING OUT IN THE ATLANTIC WILL DRIFT NWD THRU THE DAY...AND MAY BACK SOME SHRA TOWARDS THE MIDCOAST. HAVE SOME LOW POP FOR THE AFTERNOON THERE...WHILE GRADUALLY INCREASING POP FROM THE W AS COLD FNT APPROACHES LATE IN THE DAY. && .SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/... EXPECT THAT MOST OF THE SHRA HOLD OFF UNTIL AFTER 00Z IN THE W...AND THIS IS SUPPORTED BY THE LATEST RUNS OF THE HRRR AND SPC WRF. LOW PRES IS NOT REALLY DEEPENING...AS PARENT S/WV IS SHEARING OUT AND LIFTING QUICKLY NEWD WITH TIME. AS SUCH...NOT SEEING MUCH MECHANISM OUT THERE FOR WIDESPREAD RNFL. TRENDING POP DOWNWARDS EXCEPT IN THE MTNS...WHERE OROGRAPHIC LIFTING AND PROXIMITY TO FORCING WILL SUPPORT GREATER COVERAGE OF SHRA. WITH CLOUDS AND PCPN AROUND THE AREA...LOW TEMPS WILL BE QUITE MILD FOR THIS TIME OF YEAR. FNT QUICKLY CROSSING THE AREA EARLY THU...AS S/WV TROF AXIS PASSES E. S/WV RIDGING FOLLOWS IN ITS WAKE...SO DOWNSLOPING AND DRYING ALOFT SHOULD CLEAR OUT SHRA AND HELP TO BREAK UP CLOUDS LATE IN THE DAY. TEMPS SHOULD CLIMB WELL INTO THE 60S DURING THE DAY...WITH SRN NH AND SWRN ME MAKING A RUN INTO THE 70S WITH ENOUGH SUN. TRAILING S/WV LIFTING OUT OF THE OH RIVER VALLEY MAY SPREAD CLOUDS BACK INTO SWRN ZONES LATE IN THE DAY THU. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A MORE ACTIVE PATTERN WILL DEVELOP OVER THE REGION AS WE END OUT THE WORK WEEK. AN AREA OF LOW PRESSURE WILL RAPIDLY CROSS THE AREA THURSDAY NIGHT INTO EARLY FRIDAY MORNING. THIS WILL BRING MORE PERSISTENT SHOWERS TO THE REGION MAINLY THURSDAY NIGHT...HOWEVER THE PRECIPITATION MAY LINGER FOR A COUPLE HOURS FRIDAY MORNING. MODELS HAVE COME INTO BETTER ALIGNMENT WITH THE TIMING OF THIS SYSTEM. A WEAK RIDGE OF HIGH PRESSURE WILL BRING DRIER AIR TO THE REGION FRIDAY AFTERNOON AND FRIDAY NIGHT. OVER THE WEEKEND...CYCLONIC FLOW ALOFT WILL ALLOW FOR SCATTERED SHOWER ACTIVITY...FOLLOWED BY A REINFORCING COLD FRONT SUNDAY NIGHT. HIGH PRESSURE WILL BUILD FOR MONDAY...BUT TEMPS WILL REMAIN NEAR OR BELOW NORMAL FOR THIS TIME OF THE YEAR AS A WARM FRONT APPROACHES FROM THE WEST NEXT TUESDAY. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...AREAS OF IFR OR LOWER THIS MORNING IN COASTAL STRATUS. CONDITIONS WILL IMPROVE TO VFR TODAY...BEFORE MVFR CIGS MOVE IN FROM THE W AS COLD FNT APPROACHES THE REGION. SCT SHRA MAY MOVE INTO THE CT RIVER VALLEY AFTER 00Z. LONG TERM...VFR CONDITIONS WITH AREAS OF MVFR IN SCATTERED SHOWERS FRIDAY AFTERNOON THROUGH SUNDAY NIGHT. MORE PERSISTENT SHOWERS ARE LIKELY THURSDAY NIGHT INTO EARLY FRIDAY MORNING WITH IFR CONDITIONS AT TIMES. && .MARINE... SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA THRESHOLDS. LONG TERM...WINDS AND WAVES SHOULD REMAIN BELOW SMALL CRAFT CRITERIA WITH SEVERAL DISTURBANCES CROSSING THE WATERS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1203 AM EDT WED OCT 16 2013 .SYNOPSIS... ISSUED AT 414 PM EDT TUE OCT 15 2013 LOW PRESSURE NEAR THE TWIN CITIES TUESDAY AFTERNOON...WILL MOVE TO EASTERN LAKE SUPERIOR BY WEDNESDAY MORNING. THIS SYSTEM WILL PRODUCE SHOWERS TONIGHT ACROSS ALL OF NORTHERN MICHIGAN. NEAR NORMAL TEMPERATURES WILL LINGER BEHIND THIS SYSTEM FOR THE REST OF THE WORK WEEK. MUCH COOLER WEATHER APPEARS LIKELY BY THE END OF THE WEEKEND. && .UPDATE... ISSUED AT 1016 PM EDT TUE OCT 15 2013 TWEAKED POPS AND REMOVED THUNDER FROM THE FORECAST BASED ON CURRENT RADAR TRENDS. BEGINNING TO SEE SOME CONVECTIVE SHOWER ACTIVITY DEVELOP OVER THE SOUTHERN HALF OF LAKE MICHIGAN...NOT CONFIDENT THAT THIS WILL EVOLVE INTO ANY THUNDER THREAT GIVEN 250J/KG OF ELEVATED CAPE PER LATEST SPC MESOANALYSIS. NUMEROUS SHOWERS...WITH PATCHY DRIZZLE OVER THE HIGHER TERRAIN...WILL CONTINUE ACROSS THE CWA FOR THE REMAINDER OF THE EVENING INTO THE OVERNIGHT WITH THE DEEPEST MOISTURE NOW EXITING NE LOWER PER LATEST WATER VAPOR LOOP. SKIES WILL REMAIN OVERALL CLOUDY...BUT WOULD NOT BE SURPRISED TO SEE SOME CLEARING ASSOCIATED WITH APPROACHING DRY SLOT CLIP THE SW PORTION OF THE FORECAST AREA FOR A BRIEF TIME...BEFORE WRAP AROUND CLOUDS AND MOISTURE FILTER BACK INTO THE PICTURE LATE TONIGHT. TEMPERATURES WILL REMAIN STEADY OR SLOWLY RISE LATE THIS EVENING AS OCCLUDED FRONT APPROACHES...BUT WILL DROP BACK INTO THE 40S LATE TONIGHT AS COLD AIR ADVECTION ENSUES. UPDATE ISSUED AT 743 PM EDT TUE OCT 15 2013 LITTLE CHANGES TO THE FORECAST AT THIS TIME. SWATH OF RAINFALL ASSOCIATED WITH WAA/ISENTROPIC ASCENT IS RAPIDLY MOVING THROUGH THE CWA ATTM...AND WILL LIKELY BE OUT OF THE AREA BY AROUND 03Z. MAIN QUESTION IS WHETHER OR NOT WE CAN REDEVELOP SOME CONVECTION WITH APPROACHING DRY SLOT AND COLD FRONT. THINGS NOT LOOKING GOOD AT ALL REGARDING THAT SCENARIO...WITH NO SIGNS OF CONVECTION UPSTREAM. WHILE LATEST RUC CONTINUES TO SHOW SOME ELEVATED INSTABILITY SKIRTING MAINLY THE NORTHERN HALF OF THE CWA...SHORT TERM RUC SOUNDINGS ALSO DEPICT SOME MID LEVEL CAPPING WITH THE ARRIVAL OF SAID DRY SLOT/STEEPER MID LEVEL LAPSE RATES. WILL MAINTAIN THUNDER MENTION FOR NOW...BUT WILL LIKELY HAVE TO REMOVE IT FROM THE FORECAST BY THE NEXT UPDATE IF THINGS DON`T GET GOING SOON. OTHERWISE LINGERING MOIST BOUNDARY LAYER WILL BRING PERIODS OF LOW CLOUDS AND VERY LIGHT RAIN SHOWERS OR DRIZZLE FOR THE REMAINDER OF THE EVENING INTO THE EARLY OVERNIGHT. TEMPERATURES WILL REMAIN STEADY IN THE 50S...WITH WINDS VEERING TO THE SOUTHWEST LATER TONIGHT WITH THE FRONTAL PASSAGE AND SUBTLE INCREASE IN THE PRESSURE GRADIENT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 414 PM EDT TUE OCT 15 2013 A BIT OF A CHALLENGING FORECAST THE NEXT 24 HOURS...BUT IN THE GRAND SCHEME OF THINGS...QUITE TYPICAL FOR OCTOBER...WITH THE MAIN FORECAST ISSUES BEING RAIN AND POSSIBLE CONVECTION THROUGH THE EVENING...AND LAKE EFFECT/WATERSPOUT ISSUES INTO WEDNESDAY. EARLY AFTERNOON ANALYSIS PLACES A RATHER POTENT CLOSED LOW MEANDERING THROUGH SOUTHERN MINNESOTA...TAKING ON THE CLASSIC OCCLUDING CYCLONE LOOK THE PAST 12 HOURS. A DISTINCT DRY SLOT IS JUST NOW PUNCHING THROUGH THE WESTERN LAKES...WITH A NARROW RIBBON OF DEEP MOISTURE (PWAT VALUES IN EXCESS OF 1.1 INCHES) NOTED FLOWING FROM THE BAJA PENINSULA RIGHT UP INTO OUR NECK OF THE WOODS. REGIONAL RADAR MOSAIC SHOWS A NICE BATCH OF RAIN FINALLY WORKING EAST FROM WISCONSIN INTO LAKE MICHIGAN AND BUMPING UP AGAINST THE NORTHWEST CWA...WITH A BIT MORE NARROWED RAIN SHIELD EXTENDING INTO THE LOWER LAKES AND TO A GREATER EXTENT THE WESTERN TENNESSEE/MID MISSISSIPPI VALLEY. THAT NORTHERN RAIN SHIELD IS ASSOCIATED WITH A DECENT AXIS OF BOTH LOW/MID LEVEL WARM ADVECTION ASCENT AND PRONOUNCED 850-500MB QG UPWARD FORCING...WHILE THE SOUTHERN STUFF IS MORE TIED TO AN UPPER JET STREAK/JET FORCING RIDING THROUGH THE SOUTHERN PLAINS. THE BIG QUESTION FOR LATE AFTERNOON/EVENING IS JUST WHAT TYPE OF RAIN COVERAGE/AMOUNTS WE WILL END UP WITH. NO DOUBT THE CURRENT RAIN SHIELD WILL CONTINUE ITS SLOW NORTH/NORTHEAST JAUNT...SUGGESTING GOING CATEGORICAL POPS ARE JUST FINE FOR MUCH OF NORTHWEST LOWER AND EASTERN UPPER. THE BIG QUESTION IS WHAT HAPPENS ACROSS NORTHEAST LOWER AS THAT BAND MAY FIZZLE WITH TIME AS IT OUTRUNS THE BETTER ASCENT WHILE A NOTABLE BREAK HAS ALREADY DEVELOPED ACROSS THE SOUTHERN LAKES. A BIT CONCERNED THIS BREAK MAY SLIDE NORTHEASTWARD ON THE DOWNWARD SIDE OF THE UPPER JET AND PROVIDE LESSER AMOUNTS WITH EASTWARD EXTENT. HOWEVER...WITH THAT SAID...STILL BELIEVE JUST ABOUT ALL FOLKS WILL END UP WITH SOME MEASURABLE RAINS AND CATEGORICAL POPS WILL CONTINUE. AS FOR CONVECTIVE CHANCES...CONFIDENCE IS WANING GIVEN THE LACK OF ANY UPSTREAM ACTIVITY JUST YET. STILL LOOKING AT A QUITE STEEP PLUME OF 700-500MB LAPSE RATES (PUSHING 8C/KM) WORKING ACROSS IOWA/ SOUTHERN WISCONSIN...WHERE THERE IS SOME CLEARING ONGOING AND HINTS OF CU DEVELOPMENT. WILL HAVE TO WATCH AND SEE IF THINGS CAN GET GOING IN ANOTHER FEW HOURS...BUT WILL OVERALL LOWER THE THUNDER MENTION TO SLIGHT CHANCE AS THE ELEVATED INSTABILITY (UP TO 500J/KG) AND STEEP LAPSE RATES WILL BE THERE ALONG THE DRY SLOT...BUT CONFIDENCE IS LOW WITH THE LACK OF CURRENT ACTIVITY. OTHERWISE...DRY SLOT WILL END THE MORE WIDESPREAD RAINFALL TOWARD OR JUST AFTER MIDNIGHT...WITH MORE SHOWERY CONDITIONS POSSIBLE THE REST OF THE NIGHT...PERHAPS ENHANCED BY THE LAKES TOWARD MORNING AS H8 TEMPS COOL BACK TOWARD 3C. OUR BETTER CHANCE FOR LAKE ENHANCED PRECIP WILL COME WEDNESDAY AS THE UPPER LOW TO THE WEST OPENS UP AND SLOWLY SLIDES OVERHEAD. NICE SLUG OF DEEPER MOISTURE AND MORE THAN SUFFICIENT LAKE INSTABILITY SHOULD RESULT IN QUITE A FEW LAKE EFFECT/ENHANCED SHOWERS...WITH SOME DIURNAL COMPONENT ALSO POSSIBLE BENEATH THE UPPER COLD POOL. SHOULD SEE A WATERSPOUT THREAT FOR A TIME...ESPECIALLY WEDNESDAY MORNING AS THE DEEPER VORTICITY AXIS PULLS OVERHEAD...WHILE A SECONDARY COLD FRONT/FORCING BOUNDARY CROSSES LAKE MICHIGAN. LATEST SZILAGYI NOMOGRAM PLOTS HIGHLIGHT THIS IDEA WELL AND PROBABLY WORTH A MENTION. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 414 PM EDT TUE OCT 15 2013 OVERVIEW: FOUR-WAVE LONG WAVE PATTERN IN PLACE ACROSS THE NRN HEMISPHERE WITH LONG WAVE TROUGHINESS DEEPENING ACROSS CENTRAL NOAM IN RESPONSE TO LONG-WAVE RIDGING BUILDING FROM THE GULF OF ALASKA DOWN ALONG THE PACIFIC COAST. THIS AMPLIFIED RIDGE WEST/TROUGH EAST PATTERN STILL ON TRACK TO GET "LOCKED IN" THROUGH AT LEAST THE NEXT SEVEN TO TEN DAYS (AND BEYOND) LEADING TO THE MUCH ADVERTISED COOL DOWN AND SLIDE INTO TRUE FALL FOR THE MIDWEST/GREAT LAKES...AND A SIZABLE PART OF EASTERN NOAM FOR THAT MATTER. IN FACT...A SUBSTANTIAL COOL DOWN MAY BE IN THE WORKS AS A COUPLE POCKETS OF FAIRLY COLD AIR GET DISLODGED FROM NRN CANADA AND SLIDE DOWN INTO THE MIDWEST/GREAT LAKES REGION GOING THROUGH THE WEEKEND AND NEXT WEEK (POSSIBLY LINKED TO ONGOING TYPHOON ACTIVITY IN THE WESTERN PACIFIC). REGARDLESS...AT LEAST A POSSIBILITY THAT WE SEE A LITTLE SNOW OR AT LEAST SOME SNOW OR RAIN/SNOW MIX IN THIS CWA DURING THE COURSE OF THE EXTENDED FORECAST. IN THE SHORTER TERM...NO SNOW THROUGH THE BALANCE OF THE WORK WEEK AS WE ARE JUST NOT COLD ENOUGH...YET. BUT WE DO HAVE A COUPLE SRN STREAM WAVES TO WORRY ABOUT AS THEY ROTATE AROUND THE AFOREMENTIONED DEEPENING LONG WAVE TROUGH. FIRST OF THESE WAVES IS MOVING THROUGH THE REGION TONIGHT AND WEDNESDAY (HANDLED IN THE SHORT TERM PART OF THE FORECAST). NEXT PIECE OF SRN STREAM ENERGY/SHORT WAVE DIPPING INTO THE FOUR CORNERS REGION TODAY AND FORECAST TO SWING UP THROUGH THE MIDWEST WEDNESDAY NIGHT...THEN UP THROUGH LOWER MICHIGAN DURING THE DAY THURSDAY. NOT A PARTICULARLY MOIST SYSTEM ORIGINATING FROM THE FOUR CORNERS AND NO SUPPORTING TAP OF GULF MOISTURE. BUT IT IS A DECENT WAVE LEADING TO A NICE SHOT OF QG-UPWARD FORCING MOVING THROUGH LOWER MICHIGAN THURSDAY AFTERNOON. BEST CHANCE FOR RAINFALL LOOKING TO OCCUR ACROSS CENTRAL AND SRN LOWER MICHIGAN ALONG AND SOUTH OF THE SHORT WAVE TRACK. BUT NOT COMFORTABLE HAVING A COMPLETELY DRY FORECAST FOR THIS CWA ON THURSDAY AND HAVE INTRODUCED SOME CHANCY POPS FOR THE S/SE HALF OF THE CWA PARTICULARLY DOWN TOWARD SAGINAW BAY. THURSDAY NIGHT THROUGH FRIDAY...BEHIND THURSDAYS SYSTEM...A BRIEF LULL ANTICIPATED THURSDAY NIGHT COURTESY OF A WEDGE OF DRIER AIR/SUBTLE SHORT WAVE RIDGING AND DOWNWARD QG FORCING. THAT SAID...CERTAINLY ENOUGH LOW LEVEL COLD AIR TO WORRY ABOUT LAKE EFFECT RAIN SHOWER PROSPECTS GIVEN H8 TEMPS JUST A FEW DEGREES ABOVE 0C. BUT IN TRYING TO FIND A LEAST ONE DRY FORECAST PERIOD OVER THE NEXT SEVERAL...THURSDAY NIGHT PROBABLY HAS THE BEST SHOT AND WILL LEAVE IT DRY FOR NOW. HEADING THROUGH FRIDAY...UPPER LEVEL TROUGHINESS BEGINS TO DESCEND INTO THE UPPER MIDWEST/WESTERN GREAT LAKES BEGINNING WITH A SUBTLE COLD FRONT PASSAGE DURING THE DAY FRIDAY. POSSIBILITIES FOR ANOTHER BATCH OF RAINFALL TO DEVELOP ALONG THE FRONT...ADVANCING THROUGH THE REGION THROUGH THE DAY FRIDAY FOLLOWED BY CONTINUING LAKE INDUCED RAIN SHOWER POSSIBILITIES FRIDAY NIGHT. OVERALL...THE START OF A RATHER UNSETTLED AND COOLER PERIOD FOR THE GREAT LAKES. SATURDAY THROUGH TUESDAY (EXTENDED PERIODS)... AS MENTIONED ABOVE...SUBSTANTIAL TROUGHINESS/COLDER AIR CARVES OUT ACROSS CENTRAL AND EASTERN CANADA AND DOWN INTO THE UPPER MIDWEST AND GREAT LAKES DURING THE COURSE OF THE WEEKEND. POTENTIAL FOR ANOTHER REINFORCING PUSH OF YET COLDER AIR FOR THE FIRST HALF OF NEXT WORK WEEK. BUT THE DEVIL IS IN THE DETAILS AND THE GFS/EURO SOLUTIONS HAVE HAD SUBSTANTIAL DIFFERENCES ON JUST HOW THE PATTERN EVOLVES AND HOW COLD IT GETS. EURO HAS BEEN RELUCTANT TO DRAG THE MORE SUBSTANTIAL COLD AIR (COLD ENOUGH FOR THE MENTION OF SNOW) INTO THE GREAT LAKES UNTIL NEXT WEEK...WHILE GFS DEVELOPS A STRONGER LOW PRESSURE SYSTEM FOR SATURDAY INTO SUNDAY WHICH DRAGS -4C TO -6C H8 AIR INTO THE REGION AS EARLY AS SUNDAY (USUALLY NEED AT LEAST -5C H8 TEMPS THIS TIME OF YEAR TO SEE SNOW). THE OVERRIDING IDEA IN THE FORECAST WILL BE A STRETCH OF BELOW NORMAL TEMPERATURES AND UNSETTLED (WET) WEATHER THROUGH THE EXTENDED. BUT IT IS POSSIBLE WE SEE A LITTLE BIT OF SNOW OR RAIN/SNOW MIX FOR INLAND AREAS EITHER LATE SATURDAY INTO SUNDAY (PER GFS COLDER IDEA) OR THE EARLY TO MID PART OF THE NEXT WEEK AS SOME THE COLDEST AIR FINALLY GETS PULLED INTO THE REGION. HAVE NOT ADDED THE MENTION OF SNOW TO THE FORECAST JUST YET HOWEVER...GIVEN THE UNCERTAINTY AND GIVEN THAT...AT LEAST RIGHT NOW...WHATEVER SNOW WE MIGHT SEE LOOKS TRANSIENT AND FAIRLY LOW IMPACT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1154 PM EDT TUE OCT 15 2013 MARGINAL IFR CONDITIONS WILL CONTINUE FOR PLN AND APN...WITH MAINLY MVFR CIGS FOR TVC AND MBL FOR THE OVERNIGHT HOURS. PATCHES OF LIGHT RAIN OR DRIZZLE WILL ALSO BE IN THE REGION WITH LOW LEVEL MOISTURE IN PLACE. A SLUG OF LOWER LEVEL DRY AIR HAS MOVED UP THE SPINE OF LAKE MICHIGAN...AND MAY AFFECT MBL TONIGHT BY BRINGING PERIODS OF CLEARING/VFR CIGS...BEFORE MVFR OVERCAST OVER WISCONSIN BEGINS TO PUSH INTO THE AREA. GUSTY SOUTHWESTERLY WINDS WILL BEGIN TO RAMP UP FOR TVC/MBL LATE TONIGHT...AND FOR THE REMAINING TAF SITES WEDNESDAY MORNING...AS THE LOW PRESSURE SYSTEM DEPARTS AND THE PRESSURE GRADIENT BEGINS TO TIGHTEN. && .MARINE... ISSUED AT 414 PM EDT TUE OCT 15 2013 SOME GUSTY CONDITIONS ARE EXPECTED ON THE LAKES...INITIALLY OUT OF THE SOUTHEAST AHEAD OF AN APPROACHING COLD FRONT...THEN SWITCHING SOUTHWEST LATER TONIGHT...AND EVENTUALLY NORTHWEST ON WEDNESDAY AS ANOTHER COLD FRONT PASSES. CONDITIONS WILL LIKELY APPROACH SMALL CRAFT ADVISORY LEVELS AT VARIOUS INTERVALS...AND HAVE SIMPLY CONTINUED THE GOING ADVISORY THROUGH THE NIGHT FOR MOST OF THE WATERS...THOUGH ARGUABLY NOT ALL SPOTS WILL SEE CRITERIA ALL OF THE TIME. THIS SYSTEM WILL DEPART INTO THURSDAY...LEAVING A PERIOD OF MUCH LIGHTER WINDS...BEFORE SEVERAL MORE WEAKER LOW PRESSURE AREAS TRACK NEARBY RIGHT ON INTO THE WEEKEND. AT THIS POINT...THERE IS NO BIG INDICATION THAN ANY SIGNIFICANT PERIODS OF WIND OR WAVES WILL OCCUR TROUGH AT LEAST SUNDAY. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LHZ345-347>349. SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LHZ346. LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LMZ323-342- 344>346. SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR LMZ341. LS...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR LSZ321-322. && $$ UPDATE...NS SYNOPSIS...JZ SHORT TERM...LAWRENCE LONG TERM...ADAM AVIATION...NS MARINE...LAWRENCE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
401 PM CDT MON OCT 14 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 157 PM CDT MON OCT 14 2013 THE MASSIVE AREA OF RAIN SHOWERS OVER EASTERN SOUTH DAKOTA AND FAR SOUTHWESTERN MINNESOTA WILL BEGIN TO MAKE ITS EASTWARD SHIFT INTO MINNESOTA THIS EVENING...WITH CLOUDS AND VISIBILITIES LOWERING THROUGHOUT THE EVENING HOURS. PRECIP PROBABILITIES PEAK TO 90-100 PERCENT BETWEEN 03Z AND 09Z TUESDAY...WITH SLIGHTLY LOWER PROBABILITIES ON TUESDAY MORNING AND EARLY AFTERNOON AS THE DRY SLOT WORKS INTO THE AREA WITH THE SURFACE LOW MOVING ACROSS SOUTHERN MINNESOTA. TEMPERATURES WILL HOLD IN THE 40S TONIGHT...WITH NEARLY STEADY OR ONLY SLIGHTLY RISING READINGS ON TUESDAY MORNING. AS THE LOW PASSES BY MID DAY TUESDAY...WILL LIKELY SEE TEMPERATURES GRADUALLY FALL DURING THE AFTERNOON HOURS AS COOLER AIR INFILTRATES THE REGION. THE PASSING OF THE AREA OF LOW PRESSURE WILL ALSO BE MARKED BY BREEZY WINDS EASTERLY WINDS SHIFTING TO NORTHERLY BY TUESDAY EVENING. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 157 PM CDT MON OCT 14 2013 THE PATTERN REMAINS ACTIVE THROUGH THE WEEKEND WITH THE POTENTIAL FOR A FEW ROUNDS OF LIGHT RAIN OR POSSIBLY EVEN SOME SNOW SHOWERS IN CENTRAL MN OR NORTHWEST WI BY THE TIME WE GET TO THE WEEKEND. THE UPPER LOW RESPONSIBLE FOR THE WIDESPREAD RAIN OVER THE NEXT 36 HOURS WILL CLEAR THE FORECAST AREA EARLY WEDNESDAY MORNING. WHILE SOME RESIDUAL BL MOISTURE REMAINS...THE SOUNDINGS DRY OUT NICELY ABOVE 900 MB WITH Q-VECTOR DIVERGENCE AND SUBSIDENCE OVERHEAD BETWEEN 12-15 Z WEDNESDAY. WE MOVED THE RAIN OUT A LITTLE FASTER THAN THE PREVIOUS FORECAST FOR TUESDAY NIGHT...BUT THE CHANGE WAS VERY MINOR. NOT CURRENTLY IN THE FORECAST GIVEN THE UNCERTAINTY IN CLOUD COVER AND HOW QUICK OR IF WE DECOUPLE WEDNESDAY NIGHT...BUT FOG IS CERTAINLY A POSSIBILITY. EVEN THOUGH THE SURFACE HIGH REMAINS CENTERED OVER THE PLAINS...WE GET THE FEELING WINDS WILL GO NEAR CALM WEDNESDAY NIGHT AND THURSDAY MORNING. OTHERWISE...THERE IS GOOD MODEL AGREEMENT IN THE MASS AND MOMENTUM FIELDS THROUGH THE FIRST PART OF THE EXTENDED FORECAST /THURSDAY- SATURDAY/ AND EVEN WHEN LOOKING AT THE MODEL TEMPERATURE SPREADS THERE IS NOT A GREAT DEAL OF VARIABILITY. THERE ARE A COUPLE WEAK FRONT COMING THROUGH ON THURSDAY AFTERNOON/EVENING AND AGAIN FRIDAY NIGHT...BOTH OF WHICH COULD LEAD TO LIGHT SCATTERED SHOWERS AND A FEW HUNDREDTHS OF QPF. THE FRIDAY NIGHT FRONT IS COLD ENOUGH BASED ON THE PROFILES AND BL WETBULB TO THINK ABOUT A RAIN/SNOW MIX. EVEN IF SNOW OCCURS ACROSS THE FAR NORTHERN CWA...IT WILL MELT ON CONTACT GIVEN THE EXPECTED SURFACE TEMPS. ALTHOUGH THERE IS MORE MODEL AMBIGUITY FOR THE SECOND HALF OF THE WEEKEND...CONTINUED COOL /BELOW NORMAL/ TEMPS AND LIGHT RAIN OR RAIN/SNOW MIX ARE LIKELY. LITTLE TO NO RAIN/SNOW ACCUMULATION IS EXPECTED. HOWEVER...WE SHOULD REEMPHASIZE THAT AFTER TOMORROW...THE PRECIP WILL BE VERY LIGHT THROUGH THE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 126 PM CDT MON OCT 14 2013 PRIMARY CONCERNS ARE TIMING THE ONSET OF MODERATE RAIN AND MVFR/IFR CIGS/VSBYS. THE HRRR HASN/T BEEN TOO SHABBY TODAY MODELING PRECIPITATION TRENDS...AND EXPANDS LIGHT SHOWERS TO EAST CENTRAL MN BY LATE AFTERNOON. MORE WIDESPREAD ACTIVITY DEVELOPS OVER MN SITES AFTER 00Z...AND WI SITES BETWEEN 03Z AND 06Z. STILL LIKE THE 0.5KM NAM12 CONDENSATIONAL PRESSURE DEFICITS FOR TIMING OF CIG REDUCTIONS...WHICH WOULD EXPAND LOW-END MVFR CIGS FROM WEST TO EAST ACROSS MN SITES BETWEEN 01Z AND 05Z...WITH FURTHER REDUCTION TO IFR CIGS AT MN SITES BETWEEN 05Z AND 07Z. WI SITES WOULD SEE SIMILAR REDUCTIONS OCCUR BETWEEN 06Z AND 12Z. EXPECT RAIN TO LINGER ON TUESDAY...ALTHOUGH SOME DRY SLOTTING MAY YIELD PRECIP BREAKS FROM SOUTH/EAST CENTRAL MN INTO WEST CENTRAL WI DURING THE LATE MORNING AND EARLY AFTERNOON UNTIL THE DEFORMATION BAND OF PRECIP SWINGS ACROSS. ANY CIG IMPROVEMENTS TO MVFR WOULD BE BRIEF...WITH PREDOMINANT IFR CIGS EXPECTED ONCE THEY DEGRADE TONIGHT. EAST/SOUTHEAST WINDS BEGIN TO SHIFT TO THE WEST/NORTHWEST WITH THE FROPA ON TUESDAY AFTERNOON. KMSP... EXPECT THE BAND OF LIGHT RAIN SHOWERS /VFR CAT/ OVER SOUTHWEST MN TO REACH KMSP AROUND 22Z...WITH MORE MODERATE SHOWERS AND MVFR CIGS DEVELOPING BY 03Z...WHEN CIGS/VSBYS WILL ALSO START REDUCING. ANTICIPATE CIGS TO REDUCE TO AROUND 1500 FT BY 06Z...AND THEN LOWER INTO THE IFR CATEGORY BY 09Z. COULD SEE SOME BREAKS IN THE RAIN ON TUESDAY MORNING AND EARLY AFTERNOON WHEN SOME DRIER AIR WORKS IN...BUT CIGS SHOULD BE PRIMARILY IFR THROUGH THE PERIOD ONCE THEY LOWER TONIGHT. /OUTLOOK FOR KMSP/ WED...IFR/MVFR. CHANCE -RA EARLY. WINDS NW 5-10 KTS. THU...VFR. WINDS NW 10 KTS. FRI...VFR. WINDS NW 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...LS LONG TERM...CLF AVIATION...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
125 PM CDT MON OCT 14 2013 .UPDATE... FOR 18Z AVIATION DISCUSSION BELOW && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 352 AM CDT MON OCT 14 2013 HIGH PRESSURE... WHICH BROUGHT US THE BEAUTIFUL DAY ON SUNDAY WAS CENTERED OVER WISCONSIN EARLY THIS MORNING... WHILE A DEVELOPING LOW PRESSURE SYSTEM WAS LOCATED OVER NORTHEAST COLORADO. MODEL TRENDS REMAIN CONSISTENT ON DEEPENING THE LOW PRESSURE SYSTEM AS IT MOVES TO FAR SOUTHERN MINNESOTA BY MIDDAY TUESDAY AND THEN OFF TO WISCONSIN TUESDAY NIGHT. LOW LEVEL MOISTURE TRANSPORT IS ON THE INCREASE THIS MORNING ACROSS EASTERN NEBRASKA AND EASTERN SOUTH DAKOTA... WITH SHOWERS INCREASING IN COVERAGE AND INTENSITY. THE MOISTURE TRANSPORT REMAINS NEARLY STATIONARY TODAY ALONG THE I-29 CORRIDOR... WHICH KEEPS THE MAIN PRECIPITATION SHIELD THAT IS DEVELOPING FOCUSED OVER OUR WESTERN MINNESOTA COUNTIES THROUGH MUCH OF THE DAY. UPGLIDE AND SATURATION GRADUALLY SPREAD INTO EASTERN MINNESOTA THIS AFTERNOON WITH RAIN MOVING INTO THE TWIN CITIES BY LATE IN THE DAY AND ACROSS WESTERN WISCONSIN THIS EVENING. THE 00Z SPC-WRF REFLECTIVITY PROGS THROUGH 36 HOURS DEPICT QUITE WELL HOW WE FEEL THIS EVENT WILL UNFOLD. WITH THE MOISTURE TRANSPORT HOLDING BACK TO THE WEST TODAY ALONG WITH THE STRONG FORCING DEVELOPING... RAIN AMOUNTS OF AROUND AN INCH ARE LIKELY TODAY ACROSS WEST CENTRAL MINNESOTA WITH VARIOUS WRF/S...INCLUDING THE HOPWRF... SHOWING THE POTENTIAL FOR 2 TO 3 INCHES ACROSS SOUTHEAST SOUTH DAKOTA AND NORTHEAST NEBRASKA. AS THE LOW ADVANCES NORTHEAST TONIGHT... THE MOISTURE TRANSPORT WILL PROGRESS INTO EASTERN MN AND WESTERN WI AND CURVE BACK INTO WEST CENTRAL MINNESOTA. STRONG MID LEVEL FRONTOGENESIS IS DEPICTED BY ALL MODELS IN THE RESULTING DEFORMATION ZONE THAT DEVELOPS FROM EASTERN SOUTH DAKOTA THROUGH CENTRAL MINNESOTA. HENCE... THE FOCUS ON THE HIGHEST RAINFALL AMOUNTS TONIGHT ARE ACROSS EASTERN SOUTH DAKOTA THROUGH CENTRAL MINNESOTA. COMBINING TODAY AND TONIGHT YIELDS A RAINFALL FORECAST OF 2 TO 2.25 INCHES IN OUR FAR WESTERN COUNTIES WITH 1.25 TO 1.75 INCHES IN CENTRAL MINNESOTA. THIS AREA IS IN A SLIGHT RISK OF EXCESSIVE RAINFALL FROM HPC. WE ARE NOT ANTICIPATING WATER PROBLEMS AT THIS TIME GIVEN THE RECENT DRY CONDITIONS AND HOW THIS RAIN IS SPREAD OUT OVER TIME. RAIN AMOUNTS ARE LIMITED SOMEWHAT ACROSS EAST CENTRAL THROUGH SOUTH CENTRAL MINNESOTA AS A DRY SLOT MOVES IN DURING THE 06Z-12Z TIME FRAME. ANOTHER CONCERN FOR TONIGHT IS THE THREAT OF THUNDER OVER SOUTHERN MINNESOTA. BEST LI FORECASTS FROM THE NAM STILL SUGGEST NEAR ZERO PASSING THROUGH. CAPE IS SMALL (LESS THAN 250 J/KG) ABOVE THE WARM LAYER CENTERED NEAR 750 MB. THE THREAT SEEMS MINIMAL AND IT WAS KEPT OUT OF THE FORECAST. SPC ALSO HAS US OUTSIDE OF THE GENERAL THUNDER CONTOUR. THE TEMPERATURE FORECAST TODAY IS A TOUGH ONE WITH THE CLOUDS AND DEVELOPING PRECIPITATION IN THE WEST ALONG WITH SOME SUNSHINE EARLY ON IN THE EAST. TEMPERATURES IN THE WEST ARE LIKELY TO BE NEARLY STEADY IN THE UPPER 40S TO LOWER 50S WITH A RUN INTO THE LOWER 60S FORECAST FOR SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN. LOWS TONIGHT WILL BE QUITE MILD AHEAD OF THE LOW WITH MIDDLE TO UPPER 40S COMMON. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 352 AM CDT MON OCT 14 2013 THE LONG TERM PERIOD WILL START WITH THE UPPER LOW CURRENTLY DOWN IN THE FOUR CORNERS REGION ENTERING SW MN TUESDAY MORNING. THIS LOW WILL FILL AND MOVE INTO THE GREAT LAKES ON WEDNESDAY AS SHORT WAVE RIDGING MOVES ACROSS THE REGION OUT AHEAD OF A DEEP TROUGH THAT WILL CARVE ITSELF OUT A HOME FROM HUDSON BY BACK SOUTHWEST TO THE BAJA PENINSULA FRIDAY INTO THE WEEKEND. MODEL SPREAD/DISCREPANCIES ARE FAIRLY MINIMAL THROUGH FRIDAY...BUT AGREEMENT ON SMALL SCALE DETAILS BEGINS TO BREAK DOWN FAIRLY QUICKLY BY THE WEEKEND. TUESDAY MORNING WILL BE STARTING OUT WITH A SFC LOW OVER SW MN THAT WILL SLIDE OVER TO NEAR GREEN BAY BY THE END OF THE DAY TUESDAY. AHEAD OF THIS LOW...MODELS CONTINUE TO SHOW A MID LEVEL DRY SLOT WORKING UP TO ABOUT THE TWIN CITIES TUESDAY MORNING THAT THEN SLIDES EAST WITH THE LOW DURING THE DAY. FORECAST SOUNDINGS SHOW THE MOIST LAYER EXTENDING FROM THE SFC UP TO ABOUT 825 MB...WITH IT DRY ABOVE THAT. OMEGA WITHIN THIS MOIST LAYER REMAINS NEGATIVE...WHICH MEANS UPWARD MOTION WILL CONTINUE DESPITE THE LOSS OF DEEP MOISTURE...PERFECT CONDITIONS FOR THE FORMATION OF DRIZZLE. THEREFORE...ADDED A DRIZZLE MENTION TO THE FORECAST TUESDAY MORNING THROUGH THE AFTERNOON BENEATH THE DRY SLOT FROM SOUTH CENTRAL MN INTO WRN WI. NORTH AND WEST OF THE DRY SLOT...AN ACTIVE DEFORMATION REGION IS EXPECTED TO PERSIST THROUGH THE DAY ON TUESDAY...SO EXTENDED CATEGORICAL POPS THROUGH THE DAY ACROSS MOST OF THE MN CWA TO ACCOUNT FOR THE LIGHT DEFORMATION RAINS EXPECTED TO MOVE IN RIGHT BEHIND THE DRY SLOT. PRECIP WILL END FROM WEST TO EAST TUESDAY NIGHT AND ENDED ANY RAIN MENTION IN THE ERN CWA AFTER 15Z WEDNESDAY. FOR WEDNESDAY...MAINLY SUNNY SKIES ARE EXPECTED. THE NEXT FRONT TO PUSH THROUGH THE AREA WILL BE PUSHING INTO NODAK DURING WEDNESDAY AFTERNOON AND A SLIGHT REBOUND IN LOW LEVEL TEMPS/THICKNESSES WILL ALLOW TEMPERATURES TO WARM BACK SIMILAR TO WHAT WAS SEEN SUNDAY...JUST A COUPLE OF DEGREES COOLER. THAT FRONT WILL PUSH ACROSS THE MPX AREA ON THURSDAY. FORECAST SOUNDINGS ARE STILL QUITE DRY IN THE WAKE OF THE EARLY WEEK SYSTEM AND THIS FRONT WILL NOT HAVE MUCH MOISTURE TO WORK WITH...HENCE A MAINLY DRY PASSAGE IS EXPECTED. AT THIS POINT...MODELS SHOW BEST PRECIP CHANCES EXISTING OVER IN WI THU AFTERNOON...WHEN THE GFS SHOWS WEAK...MOIST UPGLIDE ON THE 290K/295K SFCS. COLD ADVECTION WILL SET IN BEHIND THE FRONT...RESULTING IN STEEP LAPSE RATES AND UNSTABLE SOUNDINGS FOR FRIDAY...WHICH LOOKS TO FEATURE BREEZY NW WINDS...PLENTY OF STRATOCU...AND SCATTERED SHOWERS. GIVEN FREEZING LEVELS DOWN UNDER H85 /AROUND 3K FT AGL/...WOULD NOT BE AT ALL SURPRISED TO SEE SLEET MIX IN WITH ANY ACTIVITY THAT DOES DEVELOP IN THE AFTERNOON. FOR THE WEEKEND...SATURDAY MORNING LOOKS TO FEATURE THE FIRST WIDESPREAD FREEZE OF THE FALL. BEYOND THAT THOUGH...THE GFS SHOWS COLD AIR REMAINING IN PLACE THROUGH THE WEEKEND...WHILE THE ECMWF SHOWS TEMPERATURES BEGINNING TO MODIFY SATURDAY OUT AHEAD OF A STRONG CLIPPER SYSTEM IT SWINGS THROUGH ON SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 126 PM CDT MON OCT 14 2013 PRIMARY CONCERNS ARE TIMING THE ONSET OF MODERATE RAIN AND MVFR/IFR CIGS/VSBYS. THE HRRR HASN/T BEEN TOO SHABBY TODAY MODELING PRECIPITATION TRENDS...AND EXPANDS LIGHT SHOWERS TO EAST CENTRAL MN BY LATE AFTERNOON. MORE WIDESPREAD ACTIVITY DEVELOPS OVER MN SITES AFTER 00Z...AND WI SITES BETWEEN 03Z AND 06Z. STILL LIKE THE 0.5KM NAM12 CONDENSATIONAL PRESSURE DEFICITS FOR TIMING OF CIG REDUCTIONS...WHICH WOULD EXPAND LOW-END MVFR CIGS FROM WEST TO EAST ACROSS MN SITES BETWEEN 01Z AND 05Z...WITH FURTHER REDUCTION TO IFR CIGS AT MN SITES BETWEEN 05Z AND 07Z. WI SITES WOULD SEE SIMILAR REDUCTIONS OCCUR BETWEEN 06Z AND 12Z. EXPECT RAIN TO LINGER ON TUESDAY...ALTHOUGH SOME DRY SLOTTING MAY YIELD PRECIP BREAKS FROM SOUTH/EAST CENTRAL MN INTO WEST CENTRAL WI DURING THE LATE MORNING AND EARLY AFTERNOON UNTIL THE DEFORMATION BAND OF PRECIP SWINGS ACROSS. ANY CIG IMPROVEMENTS TO MVFR WOULD BE BRIEF...WITH PREDOMINANT IFR CIGS EXPECTED ONCE THEY DEGRADE TONIGHT. EAST/SOUTHEAST WINDS BEGIN TO SHIFT TO THE WEST/NORTHWEST WITH THE FROPA ON TUESDAY AFTERNOON. KMSP... EXPECT THE BAND OF LIGHT RAIN SHOWERS /VFR CAT/ OVER SOUTHWEST MN TO REACH KMSP AROUND 22Z...WITH MORE MODERATE SHOWERS AND MVFR CIGS DEVELOPING BY 03Z...WHEN CIGS/VSBYS WILL ALSO START REDUCING. ANTICIPATE CIGS TO REDUCE TO AROUND 1500 FT BY 06Z...AND THEN LOWER INTO THE IFR CATEGORY BY 09Z. COULD SEE SOME BREAKS IN THE RAIN ON TUESDAY MORNING AND EARLY AFTERNOON WHEN SOME DRIER AIR WORKS IN...BUT CIGS SHOULD BE PRIMARILY IFR THROUGH THE PERIOD ONCE THEY LOWER TONIGHT. /OUTLOOK FOR KMSP/ WED...IFR/MVFR. CHANCE -RA EARLY. WINDS NW 5-10 KTS. THU...VFR. WINDS NW 10 KTS. FRI...VFR. WINDS NW 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...RAH LONG TERM...MPG AVIATION...LS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
431 AM CDT WED OCT 16 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 430 AM CDT WED OCT 16 2013 COMPARED TO THE PAST 48 HOURS OF WIDESPREAD RAIN FOLLOWED BY FAIRLY STRONG NORTHWEST WINDS...THESE NEXT 24 HOURS ARE GOING TO BE A BENIGN CHANGE OF PACE...WITH ESSENTIALLY ZERO RISK OF MEASURABLE PRECIP AND SUSTAINED BREEZES STRUGGLING TO EXCEED 12 MPH AT MOST. HOWEVER...DUE TO FROST/FREEZE SENSITIVITIES THIS TIME OF YEAR...SKY COVER/CLOUD TRENDS HAVE TAKEN ON AN ENHANCED FORECAST FOCUS...GIVEN THE PRONOUNCED EFFECT OF CLOUD COVER ON TEMPERATURES. AS IT IS TURNING OUT...PARTS OF THE CWA ARE GOING TO FREEZE AND/OR FROST FAIRLY EFFICIENTLY THIS MORNING...WHILE OTHER PARTS OF THE AREA MAY ACTUALLY SEE MORE FAVORABLE CONDITIONS FOR FROST/FREEZE WEDNESDAY NIGHT INSTEAD. 07Z OBJECTIVE SURFACE ANALYSIS SHOWS THE LOCAL AREA POSITIONED BETWEEN A 1003 MILLIBAR LOW THAT HAS DEPARTED WELL EASTWARD INTO THE GREAT LAKES...AND A 1025 MILLIBAR HIGH CENTERED MUCH CLOSER TO HOME OVER THE NEB/KS/CO BORDER AREA. WITH THE PRESSURE GRADIENT CONTINUING TO RELAX...WEST-NORTHWEST BREEZES ACROSS MOST OF THIS CWA HAVE FINALLY EASED TO 10 MPH OR LESS...BUT WITH SLIGHTLY STRONGER SPEEDS STILL SHOWING UP NOW AND THEN MAINLY IN THE NORTHEAST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL THAT THE CWA IS POSITIONED ALMOST DIRECTLY UNDERNEATH A BROAD...SEVERELY POSITIVELY TILTED MID/UPPER LEVEL TROUGH AXIS EXTENDING IN A SOUTHWEST-NORTHEAST ORIENTATION FROM THE 4-CORNERS AREA THROUGH THE GREAT LAKES AND UP INTO EASTERN CANADA. ALONG THE SOUTHERN EDGE OF THIS TROUGH AXIS...A 105+ KT JET STREAK IS EVIDENT AT 300MB OVER THE KS/NEB BORDER. THE FOLLOWING PARAGRAPH FOCUSES SOLELY ON EXISTING FROST/FREEZE HEADLINES THIS MORNING...THE REAL HEADACHE THIS MORNING LIES WITH CLOUD COVER TRENDS PER IR AND 11-3.9 MICRON SATELLITE. ON A POSITIVE NOTE FOR CURRENT FROST/FREEZE HEADLINES...THE EXPANSIVE DECK OF LOW STRATUS THAT RULED MOST OF THE CWA ON TUESDAY CONTINUES TO STEADILY ERODE FROM NORTHWEST-TO-SOUTHEAST...WHICH MAKES IT NOW LOOK LIKE MUCH OF THE CWA SHOULD SEE AT LEAST A FEW HOURS OF CLEAR SKIES...POTENTIALLY ALLOWING FROST FORMATION TO COMMENCE. IN FACT...THIS PROCESS IS LIKELY ALREADY WELL-UNDERWAY IN/NEAR FAR WESTERN PORTIONS OF THE CWA...WHERE SITES SUCH AS LEXINGTON/MCCOOK HAVE ALREADY TUMBLED INTO THE LOW 30S THUS VERIFYING THE EXISTING FREEZE WARNING. HOWEVER...ON THE FLIP SIDE...PORTIONS OF THE ORIGINAL FROST ADVISORY ACROSS ROUGHLY THE EASTERN HALF OF THE CWA SEEMS TO BE FACING A GREATER OBSTACLE TO VERIFY...AS FOLLOWING SHORTLY BEHIND THE VACATING LOW STRATUS IS A SOUTHWARD-SINKING BAND OF MID LEVEL CLOUDS CENTERED BETWEEN 8-10K FEET...WHICH HAS ALREADY BRUSHED INTO THE FAR NORTHERN CWA...AND IS EXPECTED TO SLOWLY DROP SOUTHWARD TO AT LEAST ROUGHLY THE HIGHWAY 6 CORRIDOR BY SUNRISE. HOWEVER...THESE MID CLOUDS SHOULD HAVE LITTLE EFFECT ON EARLY MORNING TEMPERATURES ACROSS MOST OF THE SOUTHERN HALF TO ONE-THIRD OF THE CWA...WITH THESE AREAS LIKELY HEADED FOR SEVERAL HOURS OF CLEARING IN THE WAKE OF THE DEPARTING LOWER DECK. THE NET RESULT...AS IT CURRENTLY STANDS AT 09Z/4AM...IS THAT ADVISORIES/WARNINGS WERE CANCELLED FOR 5 COUNTIES NORTH OF INTERSTATE 80...WHILE AT LEAST FOR NOW WILL LET THE REMAINING 23 COUNTIES STAND AS-IS PER ORIGINAL ISSUANCE...AND TAKE ANOTHER LOOK FOR POSSIBLE UPDATES IN A FEW HOURS. TURNING TO OTHER ELEMENTS OF THE FORECAST...RIGHT OFF THE BAT DECIDED TO SLIP A SLIGHT CHANCE OF SPRINKLES INTO FAR NORTHERN AREAS UP AROUND ORD/GREELEY PRIOR TO SUNRISE TO ACCOUNT FOR A FEW WEAK RETURNS SHOWING UP ON RADAR UNDER THE INVADING MID-DECK...BUT THIS SHOULD BE VERY ISOLATED IN NATURE. BEYOND SUNRISE...ANTICIPATE A COOLISH BUT SEASONABLY PLEASANT DAY UNDER VARIABLE CLOUD COVER. ALOFT...THE AFOREMENTIONED ELONGATED MID LEVEL TROUGH AXIS WILL CONTINUE SLIPPING SOUTHWARD ACROSS THE REGION...AS A SHORTWAVE CURRENTLY WITHIN THE BASE OF THE TROUGH NEAR THE 4-CORNERS AREA GRADUALLY EJECTS EASTWARD ALONG THE KS/OK BORDER AS THE DAY WEARS ON. WHILE ANY SPOTTY RAIN FROM THIS DISTURBANCE SHOULD REMAIN WELL SOUTH OF THE LOCAL AREA...ESPECIALLY OUR KS ZONES COULD SEE A FAIR AMOUNT OF MID/UPPER LEVEL CLOUDS STREAMING EAST-NORTHEAST FROM THIS SYSTEM. MEANWHILE...THE ALREADY-PRESENT MID DECK SLIPPING INTO NORTHERN COUNTIES WILL CONTINUE TO SLOWLY SINK SOUTHWARD...AND IS EXPECTED TO PROVIDE A CLOUDY START TO THE DAY ACROSS THE MAJORITY OF NEB ZONES...BUT THEN ACCORDING TO 700 MILLIBAR RELATIVE HUMIDITY PROGS FROM THE RAP/NAM...SHOULD GRADUALLY FADE AWAY OR SCATTER OUT BY THE MID-LATE MORNING HOURS. SO...THE NET RESULT IS BEST PUT AS VARIABLE CLOUD COVER...AS NORTHERN AREAS SHOULD GENERALLY START OUT RATHER CLOUDY BUT SEE INCREASING SUN WITH TIME...WHILE SOUTHERN AREAS GENERALLY DO THE OPPOSITE AND SEE INCREASING CLOUDS WITH TIME. THESE CLOUD COVER TRENDS WILL BE TOUGH TO CAPTURE IN HOURLY FORECAST GRIDS...AND PLENTY OF UPDATES ARE LIKELY. OTHERWISE...AS THE CENTER OF THE SURFACE RIDGE AXIS SINKS SOUTH OF THE AREA TODAY...BREEZES WILL AVERAGE 10-12 MPH FROM THE WEST-NORTHWEST IN ALL AREAS. HIGH TEMPERATURES WERE ONLY TWEAKED SLIGHTLY PER A BLEND OF MET/MAV GUIDANCE AND RAP TEMPS...AND THUS WILL CONTINUE TO CALL FOR A REMARKABLY UNIFORM RANGE ACROSS THE CWA WITH ALL AREAS TOPPING OUT BETWEEN 56-59. FOR THIS EVENING/TONIGHT...THE MAIN STORY ALOFT IS THAT THE CURRENT SOUTHWEST-TO-NORTHEAST TROUGH AXIS WILL GRADUALLY BE REPLACED BY A SOUTHWEST-NORTHEAST ORIENTED SHORTWAVE RIDGE AXIS. THIS IS BECAUSE THE LOCAL AREA WILL BE IN BETWEEN TROUGHS...AS THE DISTURBANCE CENTERED OVER SOUTHERN KS AT SUNSET DEPARTS EASTWARD INTO MO...WHILE THE NEXT UPSTREAM TROUGH DROPPING SOUTHEAST TOWARD THE AREA ONLY REACHES AN AXIS FROM NORTHWEST CO TO NORTH DAKOTA BY SUNRISE THURSDAY. ALTHOUGH AM EXPECTING SKIES WEDNESDAY NIGHT AS A WHOLE TO AVERAGE CLEARER THAN THIS ONGOING NIGHT HAS BEEN...THERE IS AGAIN GOING TO BE VARIABLE CLOUD COVER EXCEPT THIS TIME SOLELY OF THE MID-UPPER VARIETY. FOR ONE...MAINLY SOUTHERN PARTS OF THE CWA WILL LIKELY START THE EVENING WITH LINGERING CLOUDS FROM THE DEPARTING DISTURBANCE...WHILE LATER IN THE NIGHT...MAINLY NORTHERN AREAS COULD SEE PASSING BATCHES OF CLOUDS OUT AHEAD OF THE APPROACHING UPSTREAM WAVE. MEANWHILE AT THE SURFACE...WINDS WILL REMAIN FAIRLY LIGHT AT SUSTAINED SPEEDS GENERALLY LESS THAN 8 MPH...BUT GRADUALLY TRANSITION FROM A SOUTHWESTERLY DIRECTION TO NORTHWESTERLY IN RESPONSE TO A SUBTLE PASSING TROUGH AXIS. AS FOR LOW TEMPS...ONCE AGAIN PASSING CLOUDS COULD POSE ISSUES...BUT FOR NOW STUCK VERY CLOSE TO A MET/MAV GUIDANCE BLEND...WHICH PUTS THE MAJORITY OF THE CWA DOWN BETWEEN 33-36 DEGREES...WITH THE TYPICALLY FAVORED DAWSON-TO-VALLEY COUNTY CORRIDOR MOST FAVORED TO SLIP SLIGHTLY BELOW FREEZING. OBVIOUSLY THESE LOWS ARE AGAIN SUPPORTIVE OF FROST AND/OR FREEZE DEVELOPMENT. HOWEVER...GIVEN THE ONGOING COMPLICATIONS/UNCERTAINTY THIS MORNING REGARDING LOW TEMPS...WILL HOLD OFF ON ANY WEDNESDAY NIGHT FROST ADVISORIES/FREEZE WARNINGS FOR NOW...NOT ONLY TO AVOID HEADLINE CONFUSION...BUT ALSO TO ALLOW DAY SHIFT TO IDENTIFY COUNTIES THAT COULD NOW BE RULED INELIGIBLE FROM FUTURE FROST/FREEZE HEADLINES BASED ON WHAT HAPPENS THIS MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 430 AM CDT WED OCT 16 2013 MAIN CONCERNS THIS FORECAST PERIOD LOOKS TO BE PRECIPITATION CHANCES ON FRIDAY. STARTING OUT THURSDAY MORNING WITH THE BIG PICTURE...THERE SHOULD BE A HIGH AMPLITUDE RIDGE JUST OFF THE PACIFIC U.S. AND CANADIAN COAST WITH A LONG WAVE TROUGH AND SEVERAL EMBEDDED SHORT WAVES SITUATED OVER MUCH OF THE CONUS. THIS PATTERN WILL GRADUALLY SHIFT EAST A BIT BUT THE CENTRAL PLAINS SHOULD STILL BE SITTING ON THE BACK SIDE OF THE UPPER TROUGH BY NEXT TUESDAY...PUTTING US IN NORTHWEST FLOW. AT THE SURFACE ON TUESDAY MORNING...A TROUGH OF LOW PRESSURE EXTENDING FROM LAKE SUPERIOR TO THE OKLAHOMA PANHANDLE SHOULD BE JUST ABOUT THROUGH THE CWA WITH A WIND SHIFT FROM SOUTHWEST TO NORTHWEST. THE COOLER AIR WILL LAG BEHIND THE TROUGH A WAYS AND THURSDAY SHOULD BE QUITE NICE...JUST A FEW DEGREES LOWER THAN SEASONAL NORMALS. THE NEXT IN THE PROGRESSION OF MID LEVEL SHORTWAVES NOTED ABOVE IS THEN SLATED TO APPROACH THE PLAINS FROM THE NORTHWEST THURSDAY NIGHT INTO FRIDAY. SEVERAL MODELS SHOW A SIMILAR SOLUTION IN TAKING ONE WAVE NORTH AND EAST OF US AND DIGGING ANOTHER WAVE TO OUR WEST AND THEN SOUTH ACROSS KANSAS. INTERESTING TO RUN A TIME HEIGHT SECTION COMPARING THE GRAND ISLAND AREA TO THE PHILLIPSBURG KANSAS AREA IN TERMS OF MID LEVEL FORCING. THE NAM IS ONLY PRODUCING 1-2 UBARS PER SEC OF OMEGA OVER KGRI AT 12Z FRIDAY WHILE AT KPHG IT IS GENERATING 10-12 UBARS PER SEC. THE GFS HAS SIMILAR RESULTS FOR OUR SOUTHERN CWA WITH THE ONLY DIFFERENCE BEING THE GFS HAS A LITTLE LESS LOW LEVEL MOISTURE TO WORK WITH AND MAY TAKE A WHILE TO SATURATE THE COLUMN...WHILE THE NAM IS SATURATED ALL THE WAY FROM NEAR THE SURFACE TO 300 MB. THE EC FORECAST SOUNDING IS SIMILAR TO THE GFS AS IT IS NOT QUITE SATURATED UP TO 700MB. NEITHER THE GFS OR EC IS SHOWING THE LOWER PORTION BECOMING SATURATED BETWEEN 12 AND 18Z FRIDAY BUT I AM A LITTLE CONCERNED OF THE SCENARIO WHERE SNOW FALLING FROM ABOVE MOISTENS AND COOLS THE LOWER COLUMN UNTIL IT REACHES SATURATION. IF THIS WERE TO OCCUR...WE COULD SEE A LITTLE SNOW FRIDAY MORNING IN THE CWA. WILL NOT INCLUDE SNOW IN THE GRIDS FOR NOW AS I ONLY HAVE LOW TEMPERATURES FRIDAY MORNING FORECASTED TO BE AROUND 37 OR 38 DEGREES IN THE KANSAS PART OF OUR CWA...BUT IT WILL BE WORTH KEEPING AN EYE ON THE NEXT COUPLE OF DAYS. BUMPED UP POPS IN THE SOUTHERN PART OF THE CWA FOR FRIDAY AND THESE WILL NEED TO BE RAISED EVEN MORE IF THE MODELS REMAIN CONSISTENT ON THE TRACK OF THE SHORT WAVE TROUGH. THE COOLER AIR WILL THEN MAKE IT INTO THE AREA THURSDAY NIGHT AND BY FRIDAY HIGHS SHOULD BE 5 TO 10 DEGREES COOLER THAN ON THURSDAY. BUT THE COOLER WEATHER WILL ONLY LAST A DAY AS SATURDAY THROUGH TUESDAY SHOULD AGAIN BE IN THE UPPER 50S NORTH TO THE MID 60S SOUTH. WILL LEAVE REST OF FORECAST DRY FOR NOW BUT NOT TOTALLY OUT OF THE QUESTION THAT ONE OR TWO DISTURBANCES RIDING DOWN THE NORTHWEST FLOW MAY GIVE US AT LEAST A SLIGHT CHANCE FOR ADDITIONAL PRECIPITATION. && .AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1234 AM CDT WED OCT 16 2013 COMPARED TO THE PAST 48 HOURS...THESE NEXT 24 HOURS WILL BE MARKED BY IMPROVING AVIATION WEATHER IN SOUTH CENTRAL NEBRASKA...WITH THE DEPARTURE OF MVFR CEILINGS AND CONTINUED SLACKENING OF WINDS. STARTING WITH CEILINGS...THE VAST MAJORITY OF THE PERIOD IS EXPECTED TO FEATURE VFR...DESPITE AT-TIMES CONSIDERABLE MID LEVEL CLOUDS WELL UP AROUND 9KT FEET. HOWEVER...STARTING OFF RIGHT AWAY EARLY THIS MORNING...IT APPEARS THAT THE LAST GASP OF THE CURRENT MVFR DECK WILL STILL HOLD ON FOR A FEW MORE HOURS BEFORE FINALLY ERODING OR EXITING TO THE SOUTH. WILL AIM FOR AN 08Z RETURN TO VFR...BUT ITS POSSIBLE THIS COULD BE A BIT OPTIMISTIC. AS FOR SURFACE WINDS...SPEEDS WILL AVERAGE AT/BELOW 11KT FROM THE WEST- NORTHWEST THROUGHOUT THE REST OF TONIGHT INTO THE DAY WEDNESDAY...BEFORE BECOMING LIGHT AND SOUTHWESTERLY WEDNESDAY EVENING. && .GID WATCHES/WARNINGS/ADVISORIES... NE...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR NEZ041-048-049- 062>064-075>077-085>087. FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR NEZ046-047-060- 061-072>074-082>084. KS...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ007-019. FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR KSZ005-006-017- 018. && $$ SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1154 PM CDT TUE OCT 15 2013 .UPDATE... ISSUED AT 1148 PM CDT TUE OCT 15 2013 HIGH PRESSURE RIDGE INTO EAST CENTRAL ND ATTM...WITH TEMPS HOLDING 30-32 IN NORTHEAST INTO ECNTRL-CNTRL ND AND FAR NW MN. CLOUDS SLOWLY BUT SURELY TRYING TO CLEAR FROM THE NORTH-NORTHEAST AND JUST CLEARED FARGO AT 05Z. LATEST RAP SHOWS CLEARING EXITING SOUTHEAST FCST AREA BY 11Z SO STILL TIME FOR WCNTRL MN TO COOL OFF BEFORE DAYBREAK. LEFT LOWS THERE ALONE WITH LOWER 30S AS WELL. COULD BE SOME PATCHY FOG BUT NOT IN GRIDDS ATTM. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 252 PM CDT TUE OCT 15 2013 MAIN ISSUES WILL BE TIMING OF THE CLEARING OUT AND ENDING OF RAIN AS WELL AS TEMPERATURES THROUGHOUT THE PERIOD. THE UPPER LOW CURRENTLY ROTATING OVER MN WILL MOVE OFF INTO THE GREAT LAKES TONIGHT. RAIN WILL END OVER THE FAR SOUTHEASTERN COUNTIES FAIRLY EARLY THIS EVENING AS THE SFC LOW PULLS AWAY FROM THE AREA. IT LOOKS LIKE THERE WILL BE SOME PRESSURE GRADIENT AND WEST WINDS WILL KEEP US FROM COMPLETELY DECOUPLING. HOWEVER...DEW POINTS WILL BE DOWN INTO THE LOW 30S WITH EVEN SOME 20S NOT OUT OF THE QUESTION. SKIES WILL CLEAR OUT THIS EVENING. MODELS SHOW SOME HIGH RH VALUES APPROACHING FROM CANADA BY EARLY WEDNESDAY MORNING...BUT THINK THAT SKIES WILL STILL BE CLEAR ENOUGH TO GET PRETTY COLD. CONTINUED TREND OF TEMPS NEAR TO A FEW DEGREES BELOW THE FREEZING MARK. GIVEN THE LATENESS OF THE TIME OF YEAR WILL FORGO ANY HEADLINES AND ISSUE A PNS ABOUT THE END OF THE GROWING SEASON. TOMORROW SHOULD BE PRETTY QUIET WITH NEAR SEASONAL TEMPS AS NEAR ZONAL FLOW BRIEFLY SETS UP BETWEEN SYSTEMS. WESTERLY WINDS AND SUNSHINE SHOULD HELP TEMPS CLIMB INTO THE MID TO UPPER 50S. THE WARM TREND WILL BE SHORT LIVED AS ANOTHER COLD FRONT MOVES IN WEDNESDAY NIGHT. WILL CONTINUE TO KEEP SOME LOW POPS FOR LATE WEDNESDAY NIGHT AS THE FRONT MOVES THROUGH...ALTHOUGH THE NAM KEEPS MOST OF THE PRECIP TO OUR SOUTHWEST. THE OTHER MODELS CONTINUE TO SHOW SOME SCATTERED QPF SO KEPT THE SLIGHT MENTION GOING. LOWS WEDNESDAY NIGHT WILL BE A BIT WARMER THAN TUESDAY NIGHT WITH CLOUDS AND WINDS KEEPING US MIXED. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 252 PM CDT TUE OCT 15 2013 THURSDAY...THE COLD FRONT WILL CONTINUE TO PUSH ITS WAY ACROSS THE REGION. THERE SHOULD STILL BE A SLIGHT CHANCE FOR SHOWERS THURSDAY MORNING AS THE MODELS SHOW SOME WEAK FRONTOGENESIS MOVING THROUGH. TEMPS WILL BE COOLING AN MAY EVEN SHOW A NON-DIURNAL TREND AS COLD AIR ADVECTION BRINGS 850MB TEMPS DOWN BELOW THE FREEZING MARK. WIND WILL LIGHTEN AND SHIFT TO THE WEST THURSDAY NIGHT...ALTHOUGH LINGERING CLOUDS SHOULD KEEP TEMPS IN THE MID 30S. A REINFORCING SURGE OF COLD AIR WILL COME DOWN FRIDAY...KEEPING TEMPS IN THE 40S WITH SOME SCATTERED SHOWERS AS A WEAK UPPER SHORTWAVE MOVES THROUGH. FOR THE FRI NIGHT THROUGH TUE TIME PERIOD THE REGION REMAINS IN SHARP NORTHWEST FLOW ALOFT. MAIN FORECAST CHALLENGE WILL BE TIMING ANY WEAK EMBEDDED IMPULSES IN THE FLOW THAT MAY PRODUCE PCPN. AT THIS POINT THERE IS ONE FOR FRI NIGHT INTO SAT...ANOTHER ON SUN AND SUN NIGHT WITH A THIRD MON NIGHT INTO TUE. NONE OF THESE SYSTEMS ARE PARTICULARLY IMPRESSIVE AND WILL NOT LEAD TO ANY HEAVY PCPN. HOWEVER SOME LIGHT RAIN POSSIBLY CHANGING TO LIGHT SNOW AT NIGHT WILL BE POSSIBLE. TEMPS LOOK TO STAY ON THE CHILLY SIDE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1148 PM CDT TUE OCT 15 2013 BEMIDJI CLOUD DECK RISING TO VFR LEVELS AT 05Z WITH CLEARING NOW OVER LOWER RED LAKE...EXPECT BEMIDJI TO CLEAR OUT BY 08Z. CLEAR AT FARGO NOW. EXPECT CLEAR SKY AT REST OF THE AREA THRU WED AM WITH A NORTHWEST WIND TURNING MORE WEST OR WEST-SOUTHWEST TOWARD WED AM. HIGH CLOUD COVER TO INCREASE FROM NORTHWEST TO SOUTHEAST WEDNESDAY MIDDAY-AFTN AHD OF NEXT TROUGH WHICH WILL ENTER NE ND WED AFTN THEN MOVE THRU REST OF THE AREA WED EVE SWITCHING WINDS TO THE NORTHWEST. SOME MID CLOUD COVER LIKELY ALONG OR BEHIND FRONT. && .HYDROLOGY... ISSUED AT 1148 PM CDT TUE OCT 15 2013 BASED ON RISES AT RED RIVER AT WAHPETON AND EXPECTED RISE ABOVE FLOOD STAGE WED AFTN....ISSUED A RIVER FLOOD WARNING THERE. KEPT RIVER FLOOD WATCHES FOR SABIN...DILWORTH AND FARGO AS RISES TO ABOVE FLOOD STAGE MORE THAN 24 HOURS AWAY AND STILL WANT TO SEE RIVER RESPONSES FROM RAIN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...JR LONG TERM...JR/GODON AVIATION...RIDDLE HYDROLOGY...HOPPES/RIDDLE
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
248 AM CDT WED OCT 16 2013 .DISCUSSION... A COLD FRONT CURRENTLY STRETCHES FROM NEAR EVANSVILLE INDIANA TO PINE BLUFF ARKANSAS. A LARGE SHIELD OF RAIN IS PUSHING NORTHEAST ALONG THE FRONT. THE NORTHERN EDGE OF THE RAIN IS FURTHER NORTH THAN WHAT THE GFS AND NAM INITIALIZED WITH THUS FOR THIS MORNINGS FORECAST HAVE LEANED TOWARD THE LATEST HRRR RUN. THUS EXPECT RAIN TO CONTINUE TO FALL OVER AT LEAST THE NORTHWEST HALF OF THE CWA...MAINLY NORTHWEST OF A LINE FROM CLARKSDALE MISSISSIPPI TO JACKSON TENNESSEE THROUGH 10 AM. THEREAFTER...EXPECT RAIN TO GRADUALLY SHIFT SOUTHEAST AS THE DAY PROGRESSES. RAIN AND CLOUDS WILL KEEP TEMPERATURES COOL WITH A LOT OF LOCATIONS HAVING TEMPERATURES HOLD STEADY THROUGHOUT THE DAY FROM WHAT THEIR MORNING LOWS ARE. TONIGHT...EXPECT FRONT TO BE LOCATED ACROSS NORTHEAST MISSISSIPPI. MODELS INDICATING ANOTHER WEAK LOW PRESSURE CENTER DEVELOPING ALONG THE FRONT AS A SHORTWAVE MOVES INTO NORTHEAST ARKANSAS THIS EVENING. RAIN WILL SPREAD BACK NORTHWARD. ALTHOUGH A LOT OF THE PRECIPITATION WILL FALL AS VERY LIGHT RAIN OR POSSIBLY DRIZZLE SO EXPECT RAINFALL AMOUNTS TO BE ON THE LIGHT SIDE. LOWS WILL BE IN THE UPPER 40S TO UPPER 50S. THURSDAY...SHORTWAVE WILL FINALLY PUSH THE FRONT EAST OF THE AREA. EXPECT LIGHT RAIN/DRIZZLE AND CLOUDS TO REMAIN AROUND AT LEAST EASTERN PORTIONS OF THE MIDSOUTH IN THE MORNING. CONDITIONS WILL QUICKLY IMPROVE DURING THE AFTERNOON HOURS WITH A LOT OF LOCATIONS SEEING SUNSHINE BY THE END OF THE DAY. EXPECT HIGHS IN THE MID TO UPPER 60S. THURSDAY NIGHT INTO FRIDAY...SFC HIGH PRESSURE WILL BUILD OVER THE MIDSOUTH. MOSTLY CLEAR SKIES AND LIGHT WINDS WILL ALLOW LOWS TO DROP DOWN INTO THE 40S ACROSS THE ENTIRE CWA. WOULD NOT BE SURPRISED TO SEE A FEW UPPER 30 READINGS ALONG THE TENNESSEE RIVER. FRIDAY NIGHT INTO SATURDAY...MODELS ARE TRENDING TOWARD A DRIER FORECAST DURING THIS TIME FRAME. LOOKS LIKE THE LOW PRESSURE SYSTEM THAT DEVELOPS ALONG THE GULF COAST WILL BE FAR ENOUGH SOUTH TO KEEP RAIN FROM SPREADING BACK INTO THE AREA. CAN/T RULE OUT THE NORTHERN EDGE OF RAIN SKIRTING AREAS IN TALLAHATCHIE TO MONROE COUNTIES IN MISSISSIPPI ON SATURDAY THUS HAVE LEFT SMALL POPS. IN ADDITION...THERE WILL BE A REINFORCING COLD FRONT THAT MOVES INTO THE AREA LATE FRIDAY NIGHT INTO SATURDAY FROM THE NORTH. GFS SHOWS THE FRONT MOVING THROUGH DRY WHILE THE ECMWF SHOWS VERY LIGHT QPF OVER THE AREA. FOR NOW HAVE JUST KEPT 20 POPS ACROSS THE ENTIRE CWA BUT WOULD NOT BE SURPRISED IF THE DAY SHIFT WILL BE ABLE TO REMOVE CHANCES. HIGH PRESSURE WILL SETTLE BACK OVER THE CWA FOR THE LATTER PART OF THE WEEKEND INTO EARLY NEXT WEEK. EXPECT SUNDAY NIGHT TO BE ANOTHER CHILLY NIGHT WITH SEVERAL LOCATIONS ACROSS WEST TENNESSEE AND POSSIBLY NORTHEAST MISSISSIPPI GETTING DOWN INTO THE UPPER 30S. ANOTHER COLD FRONT OR LOW PRESSURE SYSTEM MAY AFFECT THE MIDSOUTH MONDAY NIGHT INTO TUESDAY. GFS AND ECMWF HAVE DIFFERENT SOLUTIONS WITH THE ECMWF BEING DRIER. FOR NOW HAVE ADDED 20 POPS FOR TUESDAY. KRM && .AVIATION... 06Z TAF CYCLE LIGHT RAIN CONTINUES TO FALL OVER PORTIONS OF THE FORECAST AREA AND WILL CONTINUE TO MOVE ACROSS THE FORECAST AREA DURING MUCH OF THE FORECAST PERIOD. CEILINGS WILL LOWER OVERNIGHT WITH IFR CEILINGS EXPECTED BY WEDNESDAY MORNING. CEILINGS WILL BEGIN TO IMPROVE BY WEDNESDAY EVENING AND REACH VFR CONDITIONS AT KJBR AND MVFR CONDITIONS AT KMEM AND KTUP. WINDS WILL BE LIGHT AND MAINLY FROM THE SOUTH TONIGHT AND GRADUALLY SHIFT TO THE NORTHWEST ON WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... MEM 63 55 69 47 / 100 30 20 10 MKL 62 54 66 40 / 100 30 20 10 JBR 65 49 67 42 / 90 20 10 10 TUP 69 57 67 47 / 90 50 30 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1149 PM CDT TUE OCT 15 2013 .UPDATE...FOR 06Z AVIATION. && .AVIATION...06Z TAF DISCUSSION. PRECIPITATION CONTINUES TO TAKE ITS TIME GETTING INTO MIDDLE TENNESSEE...BUT DON`T WORRY. IT WILL GET HERE. WILL SHOW VFR THROUGH MOST OF THE NIGHT...BUT HAVE INTRODUCED SOME IFR INTO THE PREVAILING FOR CKV AND BNA BASED ON CURRENT UPSTREAM TRENDS. FLIGHT CATEGORIES SHOULD IMPROVE TO MVFR AS WE REACH THE AFTERNOON HOURS AT THESE SITES...BUT WIDESPREAD RAINS WILL LIKELY WREAK HAVOC ON CIGS AND VIS THROUGHOUT THE DAY...ESPECIALLY WITH ANY HEAVIER RAINS. WINDS WILL BE SLOW TO SHIFT AS THE FRONT ASSOCIATED WITH THESE RAINS DRAGS THROUGH MIDDLE TENNESSEE. SHOULD SEE A SHIFT TO THE NW AT CKV BY 12Z...BUT MAY BE MID-AFTERNOON BEFORE KBNA SEES IT. EITHER WAY...WINDS ARE EXPECTED TO BE LIGHT. UNGER && .PREV DISCUSSION... /ISSUED 733 PM CDT TUE OCT 15 2013/ UPDATE...LATEST SURFACE MAP SHOWS THE COLD FRONT EAST OF ST. LOUIS AND LITTLE ROCK, WITH WIDESPREAD SHOWERS WEST OF MIDDLE TENNESSEE. HOWEVER, THE ONGOING ACTIVITY IS HAVING A HARD TIME MAKING EASTWARD PROGRESSION GIVEN THE DRIER, STABLE AIR OF MIDDLE TENNESSEE. LATEST HRRR IS OVERPLAYING CURRENT PRECIPITATION, AND EVEN THEN SHOWS LITTLE ACTIVITY MAKING IT EAST OF I-65 PRIOR TO 06Z. THEREFORE, AM SCALING BACK EVENING POP`S, BUT MAKING NO CHANCES THEREAFTER. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 27
AREA FORECAST DISCUSSION
NWS MIAMI FL
857 AM EDT WED OCT 16 2013 .UPDATE... DO NOT PLAN TO MAKE ANY MAJOR CHANGES OTHER THAN TO ADD SLIGHT CHANCE OF SHOWERS. THE 12Z MFL SOUNDING CONTINUES TO SHOW VERY DRY ATMOSPHERE IN PLACE WITH PWAT JUST OVER AN INCH AND STRONG SUBSIDENCE CAP WITH THE BASE AT 6-8K FEET. HOWEVER, THERE HAVE BEEN ISOLATED SHOWERS OVER THE ATLANTIC THAT HAVE TEASING THE BROWARD COUNTY COAST WITH AN EFFORT TO MOVE ONSHORE WITH THE DIURNAL HEATING CYCLE BEGINNING TO TAKE SHAPE. THE HRRR ALSO SHOWS A FEW SHOWERS DEVELOPING INLAND LATE THIS AFTERNOON IN THE LOW LEVEL NORTHEAST FLOW. THESE WILL BE VERY LOW TOPPED SO RAINFALL AMOUNTS WILL BE SMALL AREA COVERAGE AND MOSTLY JUST OVER A TRACE ACCUMULATION. OTHERWISE, THE TRANQUIL WEATHER PATTERN CONTINUES. KOB && .PREV DISCUSSION... /ISSUED 218 AM EDT WED OCT 16 2013/ ..CONTINUED MOSTLY DRY WEATHER THROUGH FRIDAY BEFORE A SLIGHT CHANCE OF SHOWERS RETURN OVER SOUTH FLORIDA THIS WEEKEND... SHORT TERM... HIGH PRESSURE OVER THE SOUTHEASTERN UNITED STATES WILL REMAIN NEARLY STATIONARY TODAY THROUGH FRIDAY...AS A WEAK SURFACE TROUGH OVER THE BAHAMA ISLANDS MOVES SLOWLY WEST TO SOUTHWEST INTO THE FLORIDA KEYS. THIS WILL KEEP A NORTHEAST TO EAST WIND OVER SOUTH FLORIDA TODAY INTO FRIDAY ALLOWING FOR A SLOW INCREASE IN MOISTURE OVER THE AREA. THERE COULD BE ONE OR TWO LIGHT SHOWERS THAT AFFECT THE ATLANTIC WATERS AND THE EAST COAST METRO AREAS TODAY INTO FRIDAY...BUT THE SHOWER COVERAGE WILL BE FAR AND FEW. SO WILL KEEP THE WEATHER DRY OVER SOUTH FLORIDA THROUGH THIS TIME AND ONLY SHOW A SLIGHT 10 PERCENT POPS OVER THE AREA. PATCHY FOG IS ALSO POSSIBLE OVER SOUTH FLORIDA LATE TONIGHT AND AGAIN LATE THURSDAY NIGHT WITH EVEN AREAS OF FOG OVER THE INTERIOR PORTIONS...DUE TO THE INCREASE IN LOW LEVEL MOISTURE WORKING INTO THE AREA FROM THE ATLANTIC WATERS. SO HAVE ADDED FOG WORDING TO THE ZONES FOR LATE TONIGHT AND AGAIN LATE THURSDAY NIGHT. LONG TERM... THE HIGH OVER THE SOUTHEASTERN UNITED STATES SHOULD MOVE SLOWLY EAST INTO THE WESTERN ATLANTIC WATERS THIS WEEKEND...AS A COLD FRONT OVER THE THE CENTRAL UNITED STATES MOVES SLOWLY SOUTHEAST INTO THE SOUTHERN GULF COAST STATES. THIS WILL ALLOW FOR THE WIND FLOW TO BECOME MORE EASTERLY OVER SOUTH FLORIDA THIS WEEKEND WHICH IN TURN WILL CONTINUE TO BRING IN LOW LEVEL MOISTURE TO THE AREA. SO WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS OVER SOUTH FLORIDA THIS WEEKEND. THE FRONT WILL THEN BECOME STATIONARY OVER THE SOUTHERN GULF COAST STATES EARLY NEXT WEEK...AS THE HIGH OVER THE WESTERN ATLANTIC WATERS REMAINS NEARLY STATIONARY. THIS WILL KEEP A EAST TO SOUTHEAST WIND FLOW OVER SOUTH FLORIDA ALONG WITH LOW LEVEL MOISTURE. SO WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS OVER THE AREA FOR EARLY NEXT WEEK. MARINE... THE WINDS OVER SOUTH FLORIDA WILL REMAIN IN A NORTHEAST TO EAST DIRECTION WITH SPEEDS OF 10 KNOTS OR LESS TODAY INTO FRIDAY...BEFORE SWINGING TO A EAST TO SOUTHEAST DIRECTION THIS WEEKEND. SO THE SEAS IN THE ATLANTIC WATERS WILL REMAIN AT OR BELOW 4 FEET TODAY INTO THIS WEEKEND...WHILE IN THE GULF WATERS THE SEAS WILL BE 2 FEET OR LESS. SO BOATING CONDITIONS WILL REMAIN GOOD THROUGH THIS WEEKEND OVER BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 72 87 73 / 10 10 10 10 FORT LAUDERDALE 86 75 87 76 / 10 10 10 10 MIAMI 87 74 88 75 / 10 10 10 10 NAPLES 87 70 88 72 / 10 - 10 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ Area Forecast Discussion National Weather Service Lincoln IL 1044 AM CDT Wed Oct 16 2013 .DISCUSSION... ISSUED 1045 AM CDT Wed Oct 16 2013 Will be updating the forecast for cooler highs today (mid 50s IL river valley and lower 60s southeast IL) and increase cloud cover, similar to what we did yesterday. Otherwise rest of forecast looks on track today with breezy west winds of 10 to 20 mph and gusts of 20 to 25 mph. 1002 mb low pressure was over the eastern end of upper mi penisula with its cold front slicing through western Ohio and central KY and west TN while a secondary frontal trof was over central WI into southeast IA. Strong 550 dm 500 mb low was ne of Lake Superior with a large upper level trof extending sw into IA/NE and southern CO and northern NM where a short wave was. Low clouds over much of central and nw IL as far southeast as Mattoon and also mid level cloud deck southeast of I-70. Models show upper level trof pivoting se toward central IL and moving into the state on Thursday as short wave ejects from southern CO/northern NM toward the region. This should keep more clouds over central and nw parts of CWA while some sunshine over southeast IL allows for milder highs in the lower 60s. Temps currently in the lower 50s with Bloomington and Galesburg still at 49F. 07 && .AVIATION... ISSUED 700 AM CDT Wed Oct 16 2013 The surface low is progressing farther to the NE into the Great Lakes, while the cold front departs through Indiana. Wrap around moisture in Minnesota and Iowa has already reached PIA and SPI, and those MVFR clouds at 2-2.5K feet will reach all the way to DEC and CMI by 13z. A couple of hours of IFR clouds between 700-900 ft are being reported back across Iowa. Mixing and daytime heating should help to lift those ceilings above 1000 ft by the time that area reaches PIA around 16z. So no IFR conditions were included in the 12z TAF issuance. Ceilings may climb above 3k ft to VFR levels later this afternoon, but chances are that they will return to MVFR in the evening. We cant rule out some light drizzle or sprinkles today as a surface trough reaches IL later today. We will monitor those trends but keep a dry forecast for now. Winds will increase from the west this morning, with sustained speeds of 12-14kt and gusts to 22kt at times. Winds should diminish below 10kt by evening Shimon && .PREV DISCUSSION... ISSUED 243 AM CDT Wed Oct 16 2013 Latest surface map shows low pressure over the eastern part of the Michigan Upper Peninsula. The cold front extends southwest, and shows up as a narrow fine line through extreme southwest Indiana per radar imagery from the Evansville radar. Narrow clear slot just west of the Illinois River was about to be overtaken by a large stratocumulus deck from the northwest, and excessive mid and high clouds have been streaming northeast along the front across most of the forecast area. Main concern in the short term is with trying to time any cloud breakup today, followed by rain chances late tonight and early Thursday. Longer range issues focus on early weekend storm system and the cool weather trend which will last much of the forecast period. SHORT TERM...Today through Thursday... Latest RAP model guidance showing the mid/high clouds shifting south toward the Ohio Valley later today, as the stratocumulus pushes south of the I-72 corridor, although the NAM shows some decent break up by late morning. Given the expansive nature of the clouds, stretching all the way into northern Minnesota, will go with the more pessimistic route and keep skies mostly cloudy across the central and northern CWA today, with a bit of sunshine over the south. Went a couple degrees below the MOS guidance for highs, but this may need to be adjusted downward later if we are unable to get any breaks to develop. Shortwave currently near the 4 Corners region will zip eastward later today. 00Z model guidance closes this off as it reaches the Iowa/Illinois border toward sunrise Thursday, but ranges quite a bit in terms of any precipitation over our area. NAM is nearly dry with most of the precip near the remains of the earlier frontal boundary south of the Ohio River, while the GFS has a narrow rain axis just east of I-55. The ECMWF and Canadian models are much more bullish with widespread showers. Currently leaning toward more of the GFS solution but a bit more widespread with the showers Thursday morning, fairly similar in coverage to the earlier grids. However, am thinking that much of this will be out of the area by early afternoon, although some slight chance PoP`s will be in the afternoon forecast across the east. LONG TERM...Friday through Tuesday... A deepening upper trough over the central U.S. will be the main player this weekend, as a wedge of colder air drops southward from Canada. Some potential exists for light rain Friday night or early Saturday as the trough axis starts to shift eastward, but will maintain 20% PoP`s at this time. Some frost potential for Saturday night as winds lighten and temperatures fall into the upper 30s over the northern half of the CWA. Going into early next week, periodic lobes of energy will drop southward across the Midwest. The latest ECMWF remains quite chilly similar to the past couple runs, with 850 mb temperatures falling to around -5C by midweek, although the GFS is several degrees warmer. For now, have not strayed too far from the guidance, which keeps temperatures fairly similar throughout the period. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
911 AM CDT WED OCT 16 2013 .DISCUSSION... 306 AM CDT COOL AND PERIODICALLY DAMP WEATHER WILL DESCRIBE THE FORECAST PERIOD AS AN AMPLIFIED AND ACTIVE PATTERN SETS UP. WATER VAPOR SATELLITE IMAGERY SHOWS A LONGWAVE TROUGH THAT EXTENDS FROM JAMES BAY BACK ACROSS THE CENTRAL PLAINS TO THE FOUR CORNERS. A LARGE NORTH-SOUTH RIDGE IS IN PLACE OFF THE WEST COAST WHILE A MORE PROGRESSIVE FLOW IS FOUND OVER CENTRAL CANADA WHERE ANOTHER TROUGH AXIS IS TRANSLATING SOUTHEASTWARD. AT THE SURFACE...A LOW IS MOVING NORTHEAST ACROSS FAR NORTHERN LAKE MICHIGAN WHICH WAS RESPONSIBLE FOR PUSHING A COLD FRONT ACROSS THE AREA LAST EVENING. A RIBBON OF HIGH PRESSURE STRETCHES FROM THE PACIFIC NORTHWEST TO THE CENTRAL HIGH PLAINS. TODAY...MANY CONCERNS THIS PERIOD RANGING FROM CLOUDS AND STRATUS TO DRIZZLE. THE UPPER TROUGH EXTENDING FROM JAMES BAY SOUTHWEST HAS A CLOSED CIRCULATION EMBEDDED WITHIN IT OVER CENTRAL WISCONSIN. THIS CLOSED CIRCULATION IS EXPECTED TO OPEN UP/WEAKEN WITH THE MAIN LONGWAVE TROUGH PIVOTING ACROSS THE AREA TODAY. IR SATELLITE SHOWS A VERY LARGE AREA OF STRATUS SPREADING EASTWARD ACROSS THE LOCAL AREA. WITH THE UPPER LOW WEAKENING AS IT ARRIVES...UPWARD MOTION WILL BE DIMINISHING THROUGH THE MORNING AND HAVE SEEN THIS ALREADY OCCURRING TO THE NORTH WHERE SHOWER COVERAGE/INTENSITY HAS BEEN WANING. WITH THE EXTENSIVE STRATUS IN PLACE SURFACE WARMING WILL BE LIMITED LEAVING LOW AND MID LEVEL LAPSE RATES MEAGER. WITH THIS IN MIND EXPECT THAT THE FOCUS FOR SHOWERS WILL REMAIN NORTH OF THE AREA LEADING TO LOWER/MINIMAL POPS ACROSS NORTHERN SECTIONS OF THE LOCAL AREA. WILL GO AHEAD AND ADD DRIZZLE ACROSS NORTHERN AREAS THROUGH THE MORNING HOWEVER WITH A DECENT DEPTH OF MOISTURE AND SOME WEAK ASCENT. UPSTREAM OBS OVER THE PAST SEVERAL HOURS HAVE ALSO SHOWN A FAIR AMOUNT OF DRIZZLE. AS ALLUDED TO...THE STRATUS WILL MAKE TEMPS A CHALLENGE. STRATUS DOES LOOK TO HOLD ON THROUGH THE AFTERNOON AND WILL COMBINE WITH LOW LEVEL COLD ADVECTION TO REALLY LIMIT WARMING. UNLESS SOME BREAKS CAN DEVELOP LATE IN THE DAY ALLOWING SOME MINIMAL SUNSHINE...DO NOT EXPECT MORE THAN ABOUT A 3-5 DEGREE DIURNAL INCREASE IN TEMPS FROM MORNING LOW...QUITE A BIT COOLER THAN MOST GUIDANCE. WILL THEREFORE KEEP HIGHS IN THE LOWER 50S IN NORTHERN AREAS TO THE MID EVEN UPPER 50S FAR SOUTH...WITH A BETTER CHANCE FOR SOME SUNSHINE OVER THE EXTREME SOUTHERN PORTIONS OF THE AREA. TONIGHT THROUGH THURSDAY...ATTENTION TURNS TO THE BASE OF THE LONGWAVE UPPER TROUGH OVER THE FOUR CORNERS WHERE ANOTHER CLOSED CIRCULATION IS TAKING SHAPE. THIS LOW WILL EJECT NORTHEASTWARD AND ACROSS THE AREA THURSDAY MORNING. THIS WILL BRING ANOTHER ROUND OF SHOWERS TO MUCH OF THE AREA...ESPECIALLY THE SOUTHEAST TWO-THIRDS... STARTING LATE TONIGHT AND CONTINUING THURSDAY MORNING. TEMPS TONIGHT WILL BE DEPENDENT ON CLOUD COVER. THE LOW CLOUDS LOOK TO HANG ON THROUGH THE EVENING IF NOT THROUGH THE NIGHT. MID CLOUDS WILL BE INCREASING AHEAD OF THE APPROACHING TROUGH OVERNIGHT. WITH SOME QUESTION ABOUT HOW LONG THE LOW CLOUDS WILL HANG ON AND IF THERE WILL BE A BREAK IN CLOUD COVER BEFORE THE HIGHER CLOUDS ARRIVE WILL ONLY RAISE OVERNIGHT LOWS A FEW DEGREES IN MOST AREAS FOR NOW...WITH POTENTIAL FOR ONLY A RELATIVELY SMALL FALL OVER DAYTIME HIGHS. THE PASSAGE OF THE UPPER LOW WILL ALLOW CLOUDS TO DECREASE THURSDAY AFTERNOON WHICH SHOULD ALLOW HIGHS TO WARM SEVERAL DEGREES OVER TODAY DESPITE SIMILAR MID LEVEL TEMPS. FRIDAY THROUGH TUESDAY...THE NEXT FEATURE OF INTEREST IS THE TROUGH MOVING SOUTHEAST ACROSS THE CANADIAN ROCKIES THIS MORNING. PART OF THIS WAVE LOOKS TO SPLIT OFF AND MOVE DUE SOUTH INTO THE CENTRAL ROCKIES WHILE THE REST TRACKS SOUTHEAST ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. ALL OF THIS ENERGY WILL RESULT IN A NEW LONGWAVE TROUGH RIGHT ACROSS THE MID SECTION OF THE COUNTRY. A WAVE WILL THEN ZIP NORTHEAST ACROSS THE AREA FRIDAY EVENING/NIGHT BRINGING A LOW CHANCE FOR POPS ACROSS THE AREA...ESPECIALLY SOUTHEAST. THE LONGWAVE WILL SHIFT EASTWARD SATURDAY INTO SUNDAY WHICH WILL ALLOW EVEN COLDER MID LEVEL AIR TO SPREAD INTO THE AREA...WITH H85 TEMPS FALLING BELOW 0C. PRECIP CHANCES LOOK LESS COHERENT BUT OVERALL MINIMAL SATURDAY AND SUNDAY...THOUGH LAKE EFFECT SHOWERS LOOK TO BE IN FULL SWING EAST OF LAKE MICHIGAN. HIGHS WILL BE IN THE 50S SATURDAY AND SUNDAY. ADDITIONAL ENERGY WILL TRACK SOUTHEAST ACROSS CENTRAL CANADA INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES LATER SUNDAY THROUGH TUESDAY. THIS WILL LEAD TO ADDITIONAL PRECIP CHANCES AND CONTINUED COOL TEMPERATURES BUT THE DETAILS ARE UNCLEAR AT THIS RANGE. MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * MVFR STRATUS DECK. * POTENTIAL FOR PATCHY DRIZZLE LATE THIS MORNING. KREIN //DISCUSSION...UPDATED 12Z... MAIN STORY TODAY WILL BE BROAD STRATUS DECK THAT IS EXPECTED TO IMPACT THE AREA WITH MVFR CIGS THROUGH THE REMAINDER OF THE AND POSSIBLY THROUGH THE OVERNIGHT HOURS. LOW PRESSURE IS LIFTING ACROSS EASTERN LAKE SUPERIOR INTO ONTARIO THIS MORNING WITH TROUGHING EXTENDING SOUTHWEST ACROSS WISCONSIN AND INTO EASTERN IOWA. STRATUS DECK EXTENDS ACROSS MUCH OF THE UPPER MIDWEST...AND IS EXPECTED TO VERY GRADUALLY SLIDE EAST THROUGH THE TAF PERIOD. WHILE THE SOUTHERN HALF OF THE CLOUD COVER IS MAINLY MVFR...IFR CIGS ARE WIDESPREAD ACROSS WISCONSIN AND NORTHEASTERN IOWA...PRIMARILY WITHIN THE TROUGH AXIS. IFR CIGS MAY REACH RFD THIS MORNING...HOWEVER BY THE TIME THE TROUGH MOVES INTO THE CHICAGO AREA...IT WILL WEAKEN WITH WEAK PRESSURE RISES AT THE SURFACE...MAKING IT LESS LIKELY FOR IFR INTO THE CHICAGO TERMINALS. MOST GUIDANCE ONCE AGAIN STRUGGLING BUT THE NAM SEEMS TO HAVE DECENT OF A HANDLE ON THE LOW LEVEL MOISTURE PROFILE...KEEPING MOISTURE IN PLACE THOUGH THE OVERNIGHT HOURS THEN DEPARTING EAST TOMORROW AFTERNOON. THERE IS ALSO A SLIGHT CONCERN FOR SOME PATCHY DRIZZLE DEVELOPING LATE THIS MORNING AS A SHEARED UPPER LEVEL DISTURBANCE MOVES ACROSS THE AREA. BEST TIME FRAME WOULD BE FROM 15Z TO 18Z...AND IT COULD REDUCE VISIBILITY TO 4-5SM...BUT TOO LOW CONFIDENCE RIGHT NOW TO INCLUDE IN THE TAF. BMD //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM CONFIDENCE IN MVFR CIGS THROUGH THE REST OF TODAY AND TONIGHT. LOW CONFIDENCE IN CHANCES FOR IFR. * LOW CONFIDENCE IN DRIZZLE IMPACTING TERMINALS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...VFR. SATURDAY...SLT CHC SHRA. SUNDAY...VFR. MONDAY...CHC SHRA. TUESDAY...SLT CHC SHRA. BMD && .MARINE... 258 AM CDT LOW PRESSURE LIES OVER NORTHERN LAKE MICHIGAN THIS MORNING WITH A TRAILING COLD FRONT STRETCHING WEST ACROSS WISCONSIN INTO IOWA. WINDS ARE STRONGEST ACROSS THE SOUTHERN HALF OF THE LAKE WHERE 30 KTS ARE EXPECTED TO CONTINUE...THEN SHOULD BEGIN TO TAPER THIS AFTERNOON. A SMALL CRAFT ADVISORY WILL BE HOISTED FOR THE INDIANA NEARSHORE WATERS EAST OF BURNS HARBOR THROUGH LATE THIS EVENING. STRONGER WINDS ARE EXPECTED LATE THIS MORNING AND EARLY AFTERNOON ACROSS THE NORTHERN HALF OF THE LAKE AS THE COLD FRONT PUSHES ACROSS ALLOWING WINDS TO INCREASE WITH 30 KT GUSTS EXPECTED. WINDS WILL TAPER ACROSS THE ENTIRE LATE TONIGHT AS ANOTHER TROUGH DROPS INTO THE WESTERN LAKES REGION ALLOWING THE GRADIENT TO WEAKEN. WINDS BEGIN TO INCREASE AGAIN ON SATURDAY AS ANOTHER LOW DROPS SOUTHEAST ACROSS THE CANADIAN PRAIRIES THEN PIVOTS EAST ACROSS THE NORTHERN LAKES REGION. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 701 AM CDT Wed Oct 16 2013 .DISCUSSION... ISSUED 243 AM CDT Wed Oct 16 2013 Latest surface map shows low pressure over the eastern part of the Michigan Upper Peninsula. The cold front extends southwest, and shows up as a narrow fine line through extreme southwest Indiana per radar imagery from the Evansville radar. Narrow clear slot just west of the Illinois River was about to be overtaken by a large stratocumulus deck from the northwest, and excessive mid and high clouds have been streaming northeast along the front across most of the forecast area. Main concern in the short term is with trying to time any cloud breakup today, followed by rain chances late tonight and early Thursday. Longer range issues focus on early weekend storm system and the cool weather trend which will last much of the forecast period. SHORT TERM...Today through Thursday... Latest RAP model guidance showing the mid/high clouds shifting south toward the Ohio Valley later today, as the stratocumulus pushes south of the I-72 corridor, although the NAM shows some decent break up by late morning. Given the expansive nature of the clouds, stretching all the way into northern Minnesota, will go with the more pessimistic route and keep skies mostly cloudy across the central and northern CWA today, with a bit of sunshine over the south. Went a couple degrees below the MOS guidance for highs, but this may need to be adjusted downward later if we are unable to get any breaks to develop. Shortwave currently near the 4 Corners region will zip eastward later today. 00Z model guidance closes this off as it reaches the Iowa/Illinois border toward sunrise Thursday, but ranges quite a bit in terms of any precipitation over our area. NAM is nearly dry with most of the precip near the remains of the earlier frontal boundary south of the Ohio River, while the GFS has a narrow rain axis just east of I-55. The ECMWF and Canadian models are much more bullish with widespread showers. Currently leaning toward more of the GFS solution but a bit more widespread with the showers Thursday morning, fairly similar in coverage to the earlier grids. However, am thinking that much of this will be out of the area by early afternoon, although some slight chance PoP`s will be in the afternoon forecast across the east. LONG TERM...Friday through Tuesday... A deepening upper trough over the central U.S. will be the main player this weekend, as a wedge of colder air drops southward from Canada. Some potential exists for light rain Friday night or early Saturday as the trough axis starts to shift eastward, but will maintain 20% PoP`s at this time. Some frost potential for Saturday night as winds lighten and temperatures fall into the upper 30s over the northern half of the CWA. Going into early next week, periodic lobes of energy will drop southward across the Midwest. The latest ECMWF remains quite chilly similar to the past couple runs, with 850 mb temperatures falling to around -5C by midweek, although the GFS is several degrees warmer. For now, have not strayed too far from the guidance, which keeps temperatures fairly similar throughout the period. Geelhart && .AVIATION... ISSUED 700 AM CDT Wed Oct 16 2013 The surface low is progressing farther to the NE into the Great Lakes, while the cold front departs through Indiana. Wrap around moisture in Minnesota and Iowa has already reached PIA and SPI, and those MVFR clouds at 2-2.5K feet will reach all the way to DEC and CMI by 13z. A couple of hours of IFR clouds between 700-900 ft are being reported back across Iowa. Mixing and daytime heating should help to lift those ceilings above 1000 ft by the time that area reaches PIA around 16z. So no IFR conditions were included in the 12z TAF issuance. Ceilings may climb above 3k ft to VFR levels later this afternoon, but chances are that they will return to MVFR in the evening. We cant rule out some light drizzle or sprinkles today as a surface trough reaches IL later today. We will monitor those trends but keep a dry forecast for now. Winds will increase from the west this morning, with sustained speeds of 12-14kt and gusts to 22kt at times. Winds should diminish below 10kt by evening Shimon && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1033 AM CDT WED OCT 16 2013 .UPDATE... ISSUED AT 1028 AM CDT WED OCT 16 2013 SPOTTY DRIZZLE APPEARS TO BE ASSOCIATED WITH LIFT FROM THE 700 AND 500MB TROFS AND LOW CONDENSATION PRESSURE DEFICITS AT 700MB. RAP TRENDS HAVE THE OVERALL LIFT DISSIPATING DURING THE AFTERNOON SUGGESTING THE POTENTIAL FOR DRIZZLE INTO THE EARLY AFTERNOON. IF THE TRENDS WITH THE RAP ARE CORRECT...AREAS GENERALLY ALONG/NORTH OF HWY 30 WOULD BE FAVORED FOR DRIZZLE. TEMPERATURES SO FAR HAVE RESPONDED A FEW DEGREES SINCE THE OVERNIGHT MINS. TRENDS WILL BE MONITORED BUT THE POTENTIAL EXISTS FOR ANOTHER LOWERING OF MAX TEMPERATURES BY A FEW MORE DEGREES. UPDATE ISSUED AT 842 AM CDT WED OCT 16 2013 BASED ON CURRENT SATELLITE TRENDS...CLEARING LOOKS DOUBTFUL PRIOR TO SUNSET. RECENT RAP TRENDS ALSO SUGGEST CLOUDS REMAINING ACROSS THE AREA AS WELL DURING THE DAYLIGHT HOURS. CLOUD COVER COMBINED WITH THE WEAKENING OCTOBER SUN INDICATE A VERY SMALL DIURNAL RISE IN TEMPERATURES DURING THE DAY. ..08.. && .SYNOPSIS... ISSUED AT 300 AM CDT WED OCT 16 2013 A POSITIVELY TILTED UPPER TROF EXTENDED FROM THE WESTERN GREAT LAKES INTO SOUTHERN CA AND AZ TUESDAY EVENING. A SURFACE LOW WAS LOCATED OVER LAKE SUPERIOR WITH CYCLONIC FLOW AROUND THE LOW EXTENDING WEST INTO SOUTHWESTERN MN AND WESTERN IA. WIDESPREAD LOW CLOUDS WERE ASSOCIATED WITH THE CYCLONIC FLOW. SOME PATCHY DRIZZLE OR LIGHT RAIN WAS OCCURRING FROM CENTRAL MN INTO NORTHERN IA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CDT WED OCT 16 2013 CLOUDS TRENDS WILL BE THE MAIN CONCERN TODAY AND TONIGHT AS THE GREAT LAKES SURFACE LOW MOVES OFF TO THE NORTHEAST AND THE TRAILING CYCLONIC FLOW WEAKENS. THE LOW CLOUDS HAVE OVERSPREAD THE ENTIRE AREA EARLY THIS MORNING AND EXTEND INTO EASTERN NE AND SOUTH DAKOTA SO IT/S DOUBTFUL THAT ANY CLEARING WILL OCCUR TODAY WITH THE CYCLONIC FLOW REMAINING OVER THE AREA. PATCHY DRIZZLE OR LIGHT RAIN SHOULD BE CONFINED TO THE NORTHERN HALF OF THE FORECAST AREA TODAY. THERE IS SOME DISAGREEMENT BETWEEN THE MODELS ON CLEARING TONIGHT. THE GFS SUGGESTS THE WEST WILL SEE SOME CLEARING LATE WHILE THE NAM HOLDS HIGH H8 RH OVER THE ENTIRE AREA THROUGH 12Z THURSDAY ALONG WITH SOME WEAK LOW LEVEL CONVERGENCE...SUPPORTING LITTLE IF ANY CLEARING. IF THE LOW CLOUDS WOULD CLEAR OVER PARTS OF THE AREA TONIGHT...ANY CLEARING SHOULD BE BRIEF WITH MID/HIGH CLOUDS SPREADING OVER THE AREA AHEAD OF A S/W LIFTING OUT OF THE SOUTHWESTERN U.S. THE S/W WILL ALSO BRING A LOW CHANCE OF SOME LIGHT RAIN TO THE SOUTHEASTERN THIRD AFTER MIDNIGHT. THE EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES FROM CHANGING MUCH TODAY AND TONIGHT. 50S ARE EXPECTED TODAY WITH OVERNIGHT LOWS IN THE UPPER 30S AND LOWER 40S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 300 AM CDT WED OCT 16 2013 PATTERN CHANGE TO A PREVAILING NW FLOW TO BRING ABOUT A CHANGE TO BELOW TEMPERATURES BY THE WEEKEND...WHICH WILL REMAIN PLACE THROUGH MUCH OF NEXT WEEK. IN THE TRANSITION...WEAK SYSTEMS WILL BRING PERIODIC CHANCES FOR LIGHT PRECIPITATION LATE THIS WEEK INTO THE WEEKEND. THURSDAY THROUGH FRIDAY NIGHT...VERY LIGHT RAIN OR DRIZZLE ASSOCIATED WITH ISENTROPIC LIFT UNDER THE SHORTWAVE EXITING TO THE EAST WILL BE HANDLED WITH VERY LOW POPS THU MORNING. BY AFTERNOON...A TRANSITORY MID LEVEL SHORTWAVE RIDGE THAT FOLLOWS SHOULD BRING CLEARING SKIES ALLOWING TEMPERATURES TO RECOVER INTO THE LOWER TO MID 60S. ANOTHER SHORTWAVE AND THE BROAD CYCLONIC FLOW ALOFT SHOULD BRING INCREASING CLOUDS OVERNIGHT...BUT WITH THE BEST FORCING WELL TO THE NORTH...WILL NOT ANTICIPATE ANY PRECIPITATION. CLOUD COVER SHOULD CONFINE MINS TO THE UPPER 30S TO LOWER 40S. THE NEXT SYSTEM BRUSHES PAST TO THE SOUTH LATE FRIDAY AND WILL HAVE SLIGHT CHANCE POPS FOR LIGHT RAIN ACROSS THE SOUTH FOR FRIDAY NIGHT. COLD ADVECTION GRADUALLY INCREASES THROUGH THIS PERIOD...AND BY FRIDAY NIGHT...850 MB TEMPERATURES NEAR TO BELOW ZERO CELSIUS ARE PROGGED OVER THE AREA. WILL THUS NEED DEEP MIXING TO REACH HIGHS IN THE 50S FRIDAY...THEN CLOUD COVER TO MAINTAIN LOWS IN THE MID TO UPPER 30S FRIDAY NIGHT. OVER THE WEEKEND...THE NEXT SHORTWAVE IS GENERALLY DEPICTED PASSING TO THE NORTH AROUND SATURDAY NIGHT...AND WILL MAINTAIN ONLY SLIGHT CHANCES FOR RAIN IN THE FAR NORTH. OTHERWISE...IMPROVING MODEL CONSISTENCY...BOTH FROM RUN TO RUN AND BETWEEN MODELS...SHOW 850 MB TEMPERATURES COOLING TO ZERO TO 4 BELOW BY SUNDAY SUPPORT WELL BELOW NORMAL SURFACE TEMPERATURES. ADVERTISED HIGHS IN THE 50S MAY BE TOO OPTIMISTIC...ESPECIALLY SUNDAY DEPENDING ON CLOUD TRENDS. LIKEWISE...CURRENT OVERNIGHT LOWS COULD POTENTIALLY BE COLD ENOUGH FOR A WIDESPREAD KILLING FREEZE...ESPECIALLY SUNDAY MORNING. HOWEVER...FOR NOW...WITH UNCERTAINTIES IN CLOUD COVER AND THE TIMING OF PASSING SURFACE RIDGE AXIS...LOWS WILL BE MAINTAINED IN THE 30S. NEXT WEEK...A CYCLONIC NW FLOW WITH PERIODIC SHORTWAVES AND REINFORCING SURFACE COLD FRONTS SETS UP OVER THE AREA THROUGH MOST OF THE WEEK. THERE IS HIGH CONFIDENCE THAT MUCH OF THE WEEK WILL FEATURE BELOW TO WELL BELOW NORMAL TEMPERATURES. HOWEVER... CHALLENGES WITH THE CRITICAL TIMING AND STRENGTH OF PASSING SHORTWAVES MAKES THIS A LOW PREDICTABILITY PATTERN THIS FAR OUT. FOR NOW...THERE IS ENOUGH CONSENSUS IN THE MODEL BLENDS TO PLACE LOW CHANCE POPS OVER MAINLY THE NORTH FOR SUNDAY NIGHT INTO MONDAY...AND THEN MORE WIDESPREAD HIGHER CHANCES FOR TUE INTO TUE NIGHT. THE LATEST GFS AND ECMWF INDICATE A STRONG SURGE OF COLD AIR BEHIND TUESDAY NIGHT/S COLD FRONT...THAT COULD LIMIT MIDWEEK HIGHS TO THE UPPER 30S OVER AT LEAST THE NORTH AND RESULT IN WIDESPREAD 20S FOR LOWS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 639 AM CDT WED OCT 16 2013 CYCLONIC FLOW AROUND LOW PRESSURE OVER LAKE HURON WILL KEEP MVFR CIGS OVER THE AREA FOR THE REST OF THE TODAY. THERE IS A NARROW BAND OF IFR CIGS OVER NORTHERN IOWA WITH THE SOUTHERN EDGE WAS AS FAR SOUTH AS HIGHWAY 20. THESE LOW CIGS COULD SAG SOUTH INTO THE HWY 30 CORRIDOR YET THIS MORNING. THE IFR CIGS WILL BE ACCOMPANIED BY SOME PATCHY DRIZZLE WITH VSBYS IN THE 3 TO 5SM RANGE. THE LOWER CIGS SHOULD LIFT ABOVE 1000 FT BY LATE MORNING OR EARLY AFTERNOON. THERE IS UNCERTAINTY ABOUT CEILING TRENDS LATE TONIGHT WITH THE 06Z MODELS RUNS SUGGESTING SOME CLEARING WILL TAKE PLACE AFTER MIDNIGHT. FOR NOW MAINTAINED CIGS AROUND 3000 FT AT ALL TAF SITES THROUGH 12Z AND WAIT TO SEE IF LATER RUNS CONTINUE THE TREND OF FASTER CLEARING. IF THERE IS SOME CLEARING OVERNIGHT THEN THERE IS POTENTIAL FOR FOG DEVELOPMENT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...DLF SHORT TERM...DLF LONG TERM...SHEETS AVIATION...DLF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
845 AM CDT WED OCT 16 2013 .UPDATE... ISSUED AT 842 AM CDT WED OCT 16 2013 BASED ON CURRENT SATELLITE TRENDS...CLEARING LOOKS DOUBTFUL PRIOR TO SUNSET. RECENT RAP TRENDS ALSO SUGGEST CLOUDS REMAINING ACROSS THE AREA AS WELL DURING THE DAYLIGHT HOURS. CLOUD COVER COMBINED WITH THE WEAKENING OCTOBER SUN INDICATE A VERY SMALL DIURNAL RISE IN TEMPERATURES DURING THE DAY. ..08.. && .SYNOPSIS... ISSUED AT 300 AM CDT WED OCT 16 2013 A POSITIVELY TILTED UPPER TROF EXTENDED FROM THE WESTERN GREAT LAKES INTO SOUTHERN CA AND AZ TUESDAY EVENING. A SURFACE LOW WAS LOCATED OVER LAKE SUPERIOR WITH CYCLONIC FLOW AROUND THE LOW EXTENDING WEST INTO SOUTHWESTERN MN AND WESTERN IA. WIDESPREAD LOW CLOUDS WERE ASSOCIATED WITH THE CYCLONIC FLOW. SOME PATCHY DRIZZLE OR LIGHT RAIN WAS OCCURRING FROM CENTRAL MN INTO NORTHERN IA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CDT WED OCT 16 2013 CLOUDS TRENDS WILL BE THE MAIN CONCERN TODAY AND TONIGHT AS THE GREAT LAKES SURFACE LOW MOVES OFF TO THE NORTHEAST AND THE TRAILING CYCLONIC FLOW WEAKENS. THE LOW CLOUDS HAVE OVERSPREAD THE ENTIRE AREA EARLY THIS MORNING AND EXTEND INTO EASTERN NE AND SOUTH DAKOTA SO IT/S DOUBTFUL THAT ANY CLEARING WILL OCCUR TODAY WITH THE CYCLONIC FLOW REMAINING OVER THE AREA. PATCHY DRIZZLE OR LIGHT RAIN SHOULD BE CONFINED TO THE NORTHERN HALF OF THE FORECAST AREA TODAY. THERE IS SOME DISAGREEMENT BETWEEN THE MODELS ON CLEARING TONIGHT. THE GFS SUGGESTS THE WEST WILL SEE SOME CLEARING LATE WHILE THE NAM HOLDS HIGH H8 RH OVER THE ENTIRE AREA THROUGH 12Z THURSDAY ALONG WITH SOME WEAK LOW LEVEL CONVERGENCE...SUPPORTING LITTLE IF ANY CLEARING. IF THE LOW CLOUDS WOULD CLEAR OVER PARTS OF THE AREA TONIGHT...ANY CLEARING SHOULD BE BRIEF WITH MID/HIGH CLOUDS SPREADING OVER THE AREA AHEAD OF A S/W LIFTING OUT OF THE SOUTHWESTERN U.S. THE S/W WILL ALSO BRING A LOW CHANCE OF SOME LIGHT RAIN TO THE SOUTHEASTERN THIRD AFTER MIDNIGHT. THE EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES FROM CHANGING MUCH TODAY AND TONIGHT. 50S ARE EXPECTED TODAY WITH OVERNIGHT LOWS IN THE UPPER 30S AND LOWER 40S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 300 AM CDT WED OCT 16 2013 PATTERN CHANGE TO A PREVAILING NW FLOW TO BRING ABOUT A CHANGE TO BELOW TEMPERATURES BY THE WEEKEND...WHICH WILL REMAIN PLACE THROUGH MUCH OF NEXT WEEK. IN THE TRANSITION...WEAK SYSTEMS WILL BRING PERIODIC CHANCES FOR LIGHT PRECIPITATION LATE THIS WEEK INTO THE WEEKEND. THURSDAY THROUGH FRIDAY NIGHT...VERY LIGHT RAIN OR DRIZZLE ASSOCIATED WITH ISENTROPIC LIFT UNDER THE SHORTWAVE EXITING TO THE EAST WILL BE HANDLED WITH VERY LOW POPS THU MORNING. BY AFTERNOON...A TRANSITORY MID LEVEL SHORTWAVE RIDGE THAT FOLLOWS SHOULD BRING CLEARING SKIES ALLOWING TEMPERATURES TO RECOVER INTO THE LOWER TO MID 60S. ANOTHER SHORTWAVE AND THE BROAD CYCLONIC FLOW ALOFT SHOULD BRING INCREASING CLOUDS OVERNIGHT...BUT WITH THE BEST FORCING WELL TO THE NORTH...WILL NOT ANTICIPATE ANY PRECIPITATION. CLOUD COVER SHOULD CONFINE MINS TO THE UPPER 30S TO LOWER 40S. THE NEXT SYSTEM BRUSHES PAST TO THE SOUTH LATE FRIDAY AND WILL HAVE SLIGHT CHANCE POPS FOR LIGHT RAIN ACROSS THE SOUTH FOR FRIDAY NIGHT. COLD ADVECTION GRADUALLY INCREASES THROUGH THIS PERIOD...AND BY FRIDAY NIGHT...850 MB TEMPERATURES NEAR TO BELOW ZERO CELSIUS ARE PROGGED OVER THE AREA. WILL THUS NEED DEEP MIXING TO REACH HIGHS IN THE 50S FRIDAY...THEN CLOUD COVER TO MAINTAIN LOWS IN THE MID TO UPPER 30S FRIDAY NIGHT. OVER THE WEEKEND...THE NEXT SHORTWAVE IS GENERALLY DEPICTED PASSING TO THE NORTH AROUND SATURDAY NIGHT...AND WILL MAINTAIN ONLY SLIGHT CHANCES FOR RAIN IN THE FAR NORTH. OTHERWISE...IMPROVING MODEL CONSISTENCY...BOTH FROM RUN TO RUN AND BETWEEN MODELS...SHOW 850 MB TEMPERATURES COOLING TO ZERO TO 4 BELOW BY SUNDAY SUPPORT WELL BELOW NORMAL SURFACE TEMPERATURES. ADVERTISED HIGHS IN THE 50S MAY BE TOO OPTIMISTIC...ESPECIALLY SUNDAY DEPENDING ON CLOUD TRENDS. LIKEWISE...CURRENT OVERNIGHT LOWS COULD POTENTIALLY BE COLD ENOUGH FOR A WIDESPREAD KILLING FREEZE...ESPECIALLY SUNDAY MORNING. HOWEVER...FOR NOW...WITH UNCERTAINTIES IN CLOUD COVER AND THE TIMING OF PASSING SURFACE RIDGE AXIS...LOWS WILL BE MAINTAINED IN THE 30S. NEXT WEEK...A CYCLONIC NW FLOW WITH PERIODIC SHORTWAVES AND REINFORCING SURFACE COLD FRONTS SETS UP OVER THE AREA THROUGH MOST OF THE WEEK. THERE IS HIGH CONFIDENCE THAT MUCH OF THE WEEK WILL FEATURE BELOW TO WELL BELOW NORMAL TEMPERATURES. HOWEVER... CHALLENGES WITH THE CRITICAL TIMING AND STRENGTH OF PASSING SHORTWAVES MAKES THIS A LOW PREDICTABILITY PATTERN THIS FAR OUT. FOR NOW...THERE IS ENOUGH CONSENSUS IN THE MODEL BLENDS TO PLACE LOW CHANCE POPS OVER MAINLY THE NORTH FOR SUNDAY NIGHT INTO MONDAY...AND THEN MORE WIDESPREAD HIGHER CHANCES FOR TUE INTO TUE NIGHT. THE LATEST GFS AND ECMWF INDICATE A STRONG SURGE OF COLD AIR BEHIND TUESDAY NIGHT/S COLD FRONT...THAT COULD LIMIT MIDWEEK HIGHS TO THE UPPER 30S OVER AT LEAST THE NORTH AND RESULT IN WIDESPREAD 20S FOR LOWS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 639 AM CDT WED OCT 16 2013 CYCLONIC FLOW AROUND LOW PRESSURE OVER LAKE HURON WILL KEEP MVFR CIGS OVER THE AREA FOR THE REST OF THE TODAY. THERE IS A NARROW BAND OF IFR CIGS OVER NORTHERN IOWA WITH THE SOUTHERN EDGE WAS AS FAR SOUTH AS HIGHWAY 20. THESE LOW CIGS COULD SAG SOUTH INTO THE HWY 30 CORRIDOR YET THIS MORNING. THE IFR CIGS WILL BE ACCOMPANIED BY SOME PATCHY DRIZZLE WITH VSBYS IN THE 3 TO 5SM RANGE. THE LOWER CIGS SHOULD LIFT ABOVE 1000 FT BY LATE MORNING OR EARLY AFTERNOON. THERE IS UNCERTAINTY ABOUT CEILING TRENDS LATE TONIGHT WITH THE 06Z MODELS RUNS SUGGESTING SOME CLEARING WILL TAKE PLACE AFTER MIDNIGHT. FOR NOW MAINTAINED CIGS AROUND 3000 FT AT ALL TAF SITES THROUGH 12Z AND WAIT TO SEE IF LATER RUNS CONTINUE THE TREND OF FASTER CLEARING. IF THERE IS SOME CLEARING OVERNIGHT THEN THERE IS POTENTIAL FOR FOG DEVELOPMENT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...DLF SHORT TERM...DLF LONG TERM...SHEETS AVIATION...DLF
AREA FORECAST DISCUSSION
NWS JACKSON KY
1129 AM EDT WED OCT 16 2013 .UPDATE... ISSUED AT 1055 AM EDT WED OCT 16 2013 ISOLATED TO SCATTERED SHOWERS CONTINUE TO WORK ACROSS EASTERN KY WITH TRACE OR GENERALLY LIGHT RAINFALL SO FAR OF A FEW HUNDREDTHS OF AN INCH...IF THAT. THE SHORT TERM MODELS...ESPECIALLY THE HRRR POINT TOWARD THE NEXT WAVE NOW OVER MIDDLE AND WESTERN TN TO WORK INTO THE AREA THIS AFTERNOON...AFFECTING THE SW PART OF THE ARE IN PARTICULAR. WITH THE DENSE CLOUD COVER SO FAR...TEMPS WERE RUNNING BEHIND THE PREVIOUS FORECAST IN THEIR CLIMB THIS MORNING. WITH THAT IN MIND...HOURLY TEMPS AS WELL AS MAX T WERE ADJUSTED DOWN A FEW DEGREES ACROSS THE BOARD. THE INCOMING MET MOS GUIDANCE SUPPORTS THIS CHANGE AS WELL. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 402 AM EDT WED OCT 16 2013 SHOWERS CONTINUE TO SKIRT ALONG THE EDGE OF THE CWA...COVERING PORTIONS OF CENTRAL KY...BUT REMAINING VERY LIGHT IN NATURE. IN FACT...MOST STATIONS ALONG THE CENTRAL PORTION OF THE STATE ARE NOT EVEN PICKING UP ANY MEASURABLE PRECIP. AS SUCH...EXPECT SHOWERS TO MAKE THEIR WAY INTO THE CWA OVER THE NEXT COUPLE OF HOURS...WHILE REMAINING LIGHT IN NATURE. LATEST HI-RES MODELS SHOW PRECIP INTENSIFYING IN COVERAGE DURING THE DAY TIME HOURS...AS THE LINE MAKES IT/S WAY EASTWARD ACROSS THE STATE. DON/T EXPECT MORE THAN A QUARTER INCH OF ACCUMULATION BY 6Z TONIGHT. THE COLD FRONT FOR WHICH THIS PRECIP IS ASSOCIATED WITH WILL PUSH INTO EASTERN KY BY 18Z TODAY. AS IT PASSES...PLACES ACROSS CENTRAL KY...AND POSSIBLY OUR FAR NORTHERN COUNTIES...CAN EXPECT SOME BRIEF CLEARING AS DRIER AIR FILTERS IN. HOWEVER...BY 0Z THIS EVENING...THE FRONT WILL STALL OUT ACROSS THE FAR EASTERN CWA...PIVOTING SOUTHWARD BUT MAKING NO EASTWARD PROGRESSION. THIS WILL KEEP A PULL OF MOISTURE FROM THE ATLANTIC INTO THE APPALACHIAN REGION...AND ENOUGH ISENTROPIC LIFT TO ALLOW LIKELY SHOWERS TO CONTINUE/REDEVELOP ACROSS MUCH OF THE CWA. AN ADDITIONAL QUARTER TO HALF INCH IS POSSIBLE IN SOME LOCATIONS IN THE CWA...MAINLY THE FAR SOUTHEASTERN FRINGES OF THE STATE. THE FRONT WILL THEN FINALLY CONTINUE TO THE SE STARTING 12Z THURSDAY...ALLOWING HIGH PRESSURE TO FINALLY TAKE IT/S PLACE ACROSS STATE THROUGH THE DAY. THE LAST OF THE PRECIP WILL MOVE OUT DURING THE AFTERNOON HOURS...WITH SKIES CLEARING A COUPLE HOURS BEHIND. AS FOR TEMPERATURES...STILL EXPECTING HIGHS TODAY IN THE UPPER 60S TO LOW 70S...WITH THE WARMEST TEMPERATURES BEING FELT ACROSS THE FAR EAST WHERE THE BETTER RAIN CHANCES WILL HOLD OFF THE LONGEST. WITH THE COLD FRONT STALLING AND PIVOTING OVERNIGHT...CLEARING WILL NOT BE AS FAST TO COME AS IN PREVIOUS FORECAST...SO EXPECT MOST OF THE REGION WILL REMAIN IN THE LOW TO MID 50S. THE EXCEPTION WILL BE THE FAR NW SECTION OF THE CWA...WHERE /AS MENTIONED ABOVE/ THE SOUTHWARD PIVOTING WILL BRING IN A BRIEF TIME OF CLEARING BEFORE MOISTURE MOVES BACK IN. LOWS HERE WILL BE SLIGHTLY COOLER...IN THE UPPER 40S. AS FOR HIGHS TOMORROW...RAISED THEM SLIGHTLY COMPARED TO PREVIOUS...DUE TO THE FACT THAT THE MOISTURE AND CLOUDS FROM THE STALLED FRONT WILL STICK AROUND LONGER AND THUS PREVENT COOLER AND DRIER AIR FROM MOVING IN. ONCE FRONT STARTS PROGRESSING EASTWARD DURING THE AFTERNOON...TEMPERATURES WILL BEGIN THEIR DESCENT. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 AM EDT WED OCT 16 2013 THE MODELS CONTINUE TO HAVE PROBLEMS RESOLVING THE EVOLUTION OF A DEEP MID-LEVEL TROUGH OVER THE NORTH CENTRAL PART OF THE COUNTRY LATER THIS WEEKEND. HOWEVER...A QUICK GLANCE AT THE LATEST ECMWF SUGGESTS THAT THERE MAY BE SOME GROWING CONSENSUS AS IT HAS BACKED OFF ITS MORE AMPLIFIED 12Z VERSION OF THE TROUGH. THE DEPARTURE OF A SMALL...BUT POTENT WAVE AT THE START OF THE EXTENDED WILL LEAVE BEHIND FAST...AND RATHER QUIET...SOUTHWEST FLOW OVER THE LOWER OHIO VALLEY INTO THE START OF THE WEEKEND BEFORE A DEEP TROUGH PUSHES EAST FROM THE HIGH PLAINS AND SWEEPS OVER THE AREA. THE BULK OF ITS ENERGY WILL LIFT NORTH INTO THE GREAT LAKES BY 00Z SUNDAY AS HEIGHTS FALL IN ITS WAKE THROUGHOUT THE OHIO VALLEY. VARIOUS WEAKER WAVES WILL THEN PASS THROUGH THE REGION IN GENERAL FAST AND FLAT FLOW. SOME AMPLIFICATION WILL TAKE PLACE LATER MONDAY AS MORE ENERGY POURS INTO THE NORTHERN PLAINS AND THE DEEPER MID CONTINENTAL TROUGH BEGINS TO BECOME REESTABLISHED TO THE NORTH OF THE CWA. GIVEN THE RECENT TROUBLES IN THE MODELS WITH THIS PATTERN WILL CONTINUE TO RESERVE JUDGMENT ON INDIVIDUAL SOLUTIONS AND FAVOR A GENERAL BLEND FOR THE EXTENDED. SENSIBLE WEATHER WILL FEATURE A RELATIVELY DRY...IF SOMEWHAT COOL... EXTENDED AS WEAK HIGH PRESSURE PASSES THROUGH THE AREA UP TO THE START OF THE WEEKEND. A DECENT FRONT WILL CROSS EAST KENTUCKY ON SATURDAY...BUT LOOKS TO BE MOISTURE STARVED WITH THE QPF MAINLY MISSING US TO THE NORTH AND ALSO SOUTH. WILL KEEP A SMALL CHANCE OF POPS IN FOR A SATURDAY AFTERNOON FROPA WITH THIS. ANOTHER WEAK HIGH PRESSURE AREA WILL MOVE INTO THE STATE FOR THE START OF THE NEW WORK WEEK...THOUGH THE NEXT FRONT MAY SNEAK INTO THE NORTHERN EXTENT OF THE CWA ON TUESDAY IN ASSOCIATION WITH THE RESURGENCE OF THE BROAD MID LEVEL TROUGH. THE CR GRID LOAD CAME IN DECENT ENOUGH GIVEN THE COMPROMISE PREFERRED ABOVE WITH LITTLE POP OR SKY ADJUSTMENTS NEEDED. AGAIN WENT WITH SOME SMALL RIDGE AND VALLEY ADJUSTMENTS TO LOW TEMPS FOR THURSDAY AND FRIDAY NIGHTS AS WELL AS SUNDAY AND MONDAY NIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 657 AM EDT WED OCT 16 2013 A COLD FRONT...CURRENTLY LOCATED ACROSS WEST-CENTRAL KY...WILL CONTINUE TO SLOWLY TREK EASTWARD INTO EASTERN KY THROUGH THE DAY. A BAND OF PRECIPITATION ALONG AND AHEAD OF THIS FRONT CONTINUES TO INCH IT/S WAY TOWARD EASTERN KY...WITH A FEW ISOLATED RETURNS POPPING UP ACROSS THE JKL CWA BORDER. SO FAR THESE SHOWERS HAVE BEEN FAIRLY LIGHT...WITH LITTLE TO NO ACCUMULATION. OVER THE NEXT FEW HOURS...EXPECT THESE SHOWERS TO CONTINUE EASTWARD AND BEGIN IMPACTING THE TAF SITES...INCREASING SLIGHTLY IN INTENSITY. AS OF NOW...MAIN CATEGORY RESTRICTIONS SHOULD COME IN THE FORM OF LOWERING MVFR CIGS RATHER THAN VISIBILITY. FRONT WILL THEN STALL OVER EASTERN KY OVERNIGHT AND PIVOT SOUTHWARD SLIGHTLY. THIS WILL LEAD TO CONTINUED CHANCES FOR RAIN ACROSS THE TAF SITES THROUGH THE NIGHT AND INTO TOMORROW MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...JMW LONG TERM...GREIF AVIATION...JMW
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1018 AM EDT WED OCT 16 2013 .SYNOPSIS... A STALLED FRONT TO OUR SOUTH WILL GRADUALLY RETURN NORTH AS A WARM FRONT LATE TONIGHT AND WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES WEDNESDAY NIGHT THEN CROSS THE AREA ON THURSDAY. WEAK LOW PRESSURE CROSSES THE AREA FRIDAY AND AGAIN ON SUNDAY BRINGING WIDESPREAD SHOWERS TO THE REGION. A WARM FRONT APPROACHES ON MONDAY WHILE HIGH PRESSURE TRIES TO BUILD IN FROM THE SOUTH. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .UPDATE...CLOUD COVER WAS ADJUSTED SLIGHTLY TO ACCOUNT FOR A FEW CLEAR SPOTS THAT ARE NOW CLOSING UP. STRATUS IS HOLDING TIGHT AND SHOULD CONTINUE THROUGHOUT THE DAY. AREA OF RAIN OFFSHORE WILL GRADUALLY SPREAD NORTH TOWARDS THE MIDCOAST TODAY. ADDED HIGHER POPS FOR ISLANDS AND OFFSHORE AREAS. && PREVIOUS DISCUSSION...WARM FNT LIFTING INTO THE REGION WILL BRING A DREARY START TO THE DAY. WEAK ONSHORE FLOW AND NEARLY SATURATED LOW LVLS WILL BRING STRATUS INTO COASTAL AREAS EARLY. WEAK WAA ALOFT WILL PROVIDE ENOUGH LIFT FOR SOME DZ IN THESE AREAS THRU SUNRISE. DAYTIME HEATING WILL EVENTUALLY HELP LIFT AND SCATTER OUT THE LOW LVLS CLOUDS...LEAVING MOSTLY HIGH AND MID LVL OVERCAST. ENOUGH PEEKS OF SUN AND INSOLATION WILL HELP TEMPS INTO THE LOW TO MID 60S. WEAK LOW PRES SPINNING OUT IN THE ATLANTIC WILL DRIFT NWD THRU THE DAY...AND MAY BACK SOME SHRA TOWARDS THE MIDCOAST. HAVE SOME LOW POP FOR THE AFTERNOON THERE...WHILE GRADUALLY INCREASING POP FROM THE W AS COLD FNT APPROACHES LATE IN THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... EXPECT THAT MOST OF THE SHRA HOLD OFF UNTIL AFTER 00Z IN THE W...AND THIS IS SUPPORTED BY THE LATEST RUNS OF THE HRRR AND SPC WRF. LOW PRES IS NOT REALLY DEEPENING...AS PARENT S/WV IS SHEARING OUT AND LIFTING QUICKLY NEWD WITH TIME. AS SUCH...NOT SEEING MUCH MECHANISM OUT THERE FOR WIDESPREAD RNFL. TRENDING POP DOWNWARDS EXCEPT IN THE MTNS...WHERE OROGRAPHIC LIFTING AND PROXIMITY TO FORCING WILL SUPPORT GREATER COVERAGE OF SHRA. WITH CLOUDS AND PCPN AROUND THE AREA...LOW TEMPS WILL BE QUITE MILD FOR THIS TIME OF YEAR. FNT QUICKLY CROSSING THE AREA EARLY THU...AS S/WV TROF AXIS PASSES E. S/WV RIDGING FOLLOWS IN ITS WAKE...SO DOWNSLOPING AND DRYING ALOFT SHOULD CLEAR OUT SHRA AND HELP TO BREAK UP CLOUDS LATE IN THE DAY. TEMPS SHOULD CLIMB WELL INTO THE 60S DURING THE DAY...WITH SRN NH AND SWRN ME MAKING A RUN INTO THE 70S WITH ENOUGH SUN. TRAILING S/WV LIFTING OUT OF THE OH RIVER VALLEY MAY SPREAD CLOUDS BACK INTO SWRN ZONES LATE IN THE DAY THU. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A MORE ACTIVE PATTERN WILL DEVELOP OVER THE REGION AS WE END OUT THE WORK WEEK. AN AREA OF LOW PRESSURE WILL RAPIDLY CROSS THE AREA THURSDAY NIGHT INTO EARLY FRIDAY MORNING. THIS WILL BRING MORE PERSISTENT SHOWERS TO THE REGION MAINLY THURSDAY NIGHT...HOWEVER THE PRECIPITATION MAY LINGER FOR A COUPLE HOURS FRIDAY MORNING. MODELS HAVE COME INTO BETTER ALIGNMENT WITH THE TIMING OF THIS SYSTEM. A WEAK RIDGE OF HIGH PRESSURE WILL BRING DRIER AIR TO THE REGION FRIDAY AFTERNOON AND FRIDAY NIGHT. OVER THE WEEKEND...CYCLONIC FLOW ALOFT WILL ALLOW FOR SCATTERED SHOWER ACTIVITY...FOLLOWED BY A REINFORCING COLD FRONT SUNDAY NIGHT. HIGH PRESSURE WILL BUILD FOR MONDAY...BUT TEMPS WILL REMAIN NEAR OR BELOW NORMAL FOR THIS TIME OF THE YEAR AS A WARM FRONT APPROACHES FROM THE WEST NEXT TUESDAY. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...AREAS OF IFR OR LOWER THIS MORNING IN COASTAL STRATUS. CONDITIONS WILL IMPROVE TO VFR TODAY...BEFORE MVFR CIGS MOVE IN FROM THE W AS COLD FNT APPROACHES THE REGION. SCT SHRA MAY MOVE INTO THE CT RIVER VALLEY AFTER 00Z. LONG TERM...VFR CONDITIONS WITH AREAS OF MVFR IN SCATTERED SHOWERS FRIDAY AFTERNOON THROUGH SUNDAY NIGHT. MORE PERSISTENT SHOWERS ARE LIKELY THURSDAY NIGHT INTO EARLY FRIDAY MORNING WITH IFR CONDITIONS AT TIMES. && .MARINE... SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA THRESHOLDS. LONG TERM...WINDS AND WAVES SHOULD REMAIN BELOW SMALL CRAFT CRITERIA WITH SEVERAL DISTURBANCES CROSSING THE WATERS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ UPDATE...HANES
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
725 AM EDT WED OCT 16 2013 .SYNOPSIS... A STALLED FRONT TO OUR SOUTH WILL GRADUALLY RETURN NORTH AS A WARM FRONT LATE TONIGHT AND WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES WEDNESDAY NIGHT THEN CROSS THE AREA ON THURSDAY. WEAK LOW PRESSURE CROSSES THE AREA FRIDAY AND AGAIN ON SUNDAY BRINGING WIDESPREAD SHOWERS TO THE REGION. A WARM FRONT APPROACHES ON MONDAY WHILE HIGH PRESSURE TRIES TO BUILD IN FROM THE SOUTH. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...MINOR CHANGES TO ACCOUNT FOR CURRENT OBSERVATIONAL TRENDS. PREVIOUS DISCUSSION...WARM FNT LIFTING INTO THE REGION WILL BRING A DREARY START TO THE DAY. WEAK ONSHORE FLOW AND NEARLY SATURATED LOW LVLS WILL BRING STRATUS INTO COASTAL AREAS EARLY. WEAK WAA ALOFT WILL PROVIDE ENOUGH LIFT FOR SOME DZ IN THESE AREAS THRU SUNRISE. DAYTIME HEATING WILL EVENTUALLY HELP LIFT AND SCATTER OUT THE LOW LVLS CLOUDS...LEAVING MOSTLY HIGH AND MID LVL OVERCAST. ENOUGH PEEKS OF SUN AND INSOLATION WILL HELP TEMPS INTO THE LOW TO MID 60S. WEAK LOW PRES SPINNING OUT IN THE ATLANTIC WILL DRIFT NWD THRU THE DAY...AND MAY BACK SOME SHRA TOWARDS THE MIDCOAST. HAVE SOME LOW POP FOR THE AFTERNOON THERE...WHILE GRADUALLY INCREASING POP FROM THE W AS COLD FNT APPROACHES LATE IN THE DAY. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... EXPECT THAT MOST OF THE SHRA HOLD OFF UNTIL AFTER 00Z IN THE W...AND THIS IS SUPPORTED BY THE LATEST RUNS OF THE HRRR AND SPC WRF. LOW PRES IS NOT REALLY DEEPENING...AS PARENT S/WV IS SHEARING OUT AND LIFTING QUICKLY NEWD WITH TIME. AS SUCH...NOT SEEING MUCH MECHANISM OUT THERE FOR WIDESPREAD RNFL. TRENDING POP DOWNWARDS EXCEPT IN THE MTNS...WHERE OROGRAPHIC LIFTING AND PROXIMITY TO FORCING WILL SUPPORT GREATER COVERAGE OF SHRA. WITH CLOUDS AND PCPN AROUND THE AREA...LOW TEMPS WILL BE QUITE MILD FOR THIS TIME OF YEAR. FNT QUICKLY CROSSING THE AREA EARLY THU...AS S/WV TROF AXIS PASSES E. S/WV RIDGING FOLLOWS IN ITS WAKE...SO DOWNSLOPING AND DRYING ALOFT SHOULD CLEAR OUT SHRA AND HELP TO BREAK UP CLOUDS LATE IN THE DAY. TEMPS SHOULD CLIMB WELL INTO THE 60S DURING THE DAY...WITH SRN NH AND SWRN ME MAKING A RUN INTO THE 70S WITH ENOUGH SUN. TRAILING S/WV LIFTING OUT OF THE OH RIVER VALLEY MAY SPREAD CLOUDS BACK INTO SWRN ZONES LATE IN THE DAY THU. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A MORE ACTIVE PATTERN WILL DEVELOP OVER THE REGION AS WE END OUT THE WORK WEEK. AN AREA OF LOW PRESSURE WILL RAPIDLY CROSS THE AREA THURSDAY NIGHT INTO EARLY FRIDAY MORNING. THIS WILL BRING MORE PERSISTENT SHOWERS TO THE REGION MAINLY THURSDAY NIGHT...HOWEVER THE PRECIPITATION MAY LINGER FOR A COUPLE HOURS FRIDAY MORNING. MODELS HAVE COME INTO BETTER ALIGNMENT WITH THE TIMING OF THIS SYSTEM. A WEAK RIDGE OF HIGH PRESSURE WILL BRING DRIER AIR TO THE REGION FRIDAY AFTERNOON AND FRIDAY NIGHT. OVER THE WEEKEND...CYCLONIC FLOW ALOFT WILL ALLOW FOR SCATTERED SHOWER ACTIVITY...FOLLOWED BY A REINFORCING COLD FRONT SUNDAY NIGHT. HIGH PRESSURE WILL BUILD FOR MONDAY...BUT TEMPS WILL REMAIN NEAR OR BELOW NORMAL FOR THIS TIME OF THE YEAR AS A WARM FRONT APPROACHES FROM THE WEST NEXT TUESDAY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...AREAS OF IFR OR LOWER THIS MORNING IN COASTAL STRATUS. CONDITIONS WILL IMPROVE TO VFR TODAY...BEFORE MVFR CIGS MOVE IN FROM THE W AS COLD FNT APPROACHES THE REGION. SCT SHRA MAY MOVE INTO THE CT RIVER VALLEY AFTER 00Z. LONG TERM...VFR CONDITIONS WITH AREAS OF MVFR IN SCATTERED SHOWERS FRIDAY AFTERNOON THROUGH SUNDAY NIGHT. MORE PERSISTENT SHOWERS ARE LIKELY THURSDAY NIGHT INTO EARLY FRIDAY MORNING WITH IFR CONDITIONS AT TIMES. && .MARINE... SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA THRESHOLDS. LONG TERM...WINDS AND WAVES SHOULD REMAIN BELOW SMALL CRAFT CRITERIA WITH SEVERAL DISTURBANCES CROSSING THE WATERS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ LEGRO/JC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
907 AM CDT WED OCT 16 2013 .UPDATE... ISSUED AT 900 AM CDT WED OCT 16 2013 OUR MORNING LOW TEMPERATURES HAVE ALREADY BEEN REACHED AND TEMPERATURES ARE NOW RISING. THEREFORE...THE FROST AND FREEZE HEADLINES HAVE BEEN ALLOWED TO EXPIRE FOR ALL AREAS. TEMPERATURES WILL AGAIN BE VERY CHILLY TONIGHT AND FROST MAY AGAIN BE POSSIBLE IN SOME AREAS BY EARLY THURSDAY MORNING. UPDATE ISSUED AT 646 AM CDT WED OCT 16 2013 LITTLE CHANGE IN THINKING FROM A FEW HOURS AGO...AS ONE DECK OF MID CLOUDS CONTINUES SINKING SOUTHWARD ACROSS THE NORTHERN CWA...WHILE MAINLY THINNER/HIGHER CIRRUS CONTINUES INCREASING INTO AREAS NEAR/SOUTH OF THE STATE LINE. IN BETWEEN...MOST PLACES BETWEEN I-80 AND THE STATE LINE ARE ESSENTIALLY CLEAR AT THIS TIME. ALTHOUGH LIGHT BUT STEADY BREEZES HAVE LIKELY PRECLUDED TRULY WIDESPREAD FROST DEVELOPMENT IN MANY AREAS...PRESENT INDICATIONS ARE THAT THE FROST/FREEZE HEADLINES ISSUED YESTERDAY WERE JUSTIFIED ACROSS MOST AFFECTED AREAS...WITH A FEW LOWS SO FAR THIS MORNING CONSISTING OF 31 AT LEXINGTON AIRPORT...32 AT RAVENNA...HOLDREGE AIRPORT AND 4WNW PLAINVILLE KS...AND 33 AT HASTINGS AIRPORT. WITH CLOUDS ON THE INCREASE...ITS BECOMING INCREASINGLY UNLIKELY THAT FROST WILL BE OBSERVED IN THE HAMILTON/YORK AND JEWELL/MITCHELL COUNTY AREAS...BUT GIVEN THAT TEMPS ARE AT LEAST IN THE BALLPARK OF SUPPORTING FROST AT THIS TIME WILL DEFER TO ONCOMING DAY SHIFT TO FORMALLY PUT THESE HEADLINES TO REST. ONCE ALL MORNING TEMPERATURE REPORTS COME IN...DECISIONS WILL ALSO BE MADE REGARDING WHICH ADDITIONAL COUNTIES BESIDES VALLEY/GREELEY ARE DEEMED INELIGIBLE FOR FUTURE FROST/FREEZE HEADLINES...AS WE WILL LIKELY BE ADDING AT LEAST A FEW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 430 AM CDT WED OCT 16 2013 COMPARED TO THE PAST 48 HOURS OF WIDESPREAD RAIN FOLLOWED BY FAIRLY STRONG NORTHWEST WINDS...THESE NEXT 24 HOURS ARE GOING TO BE A BENIGN CHANGE OF PACE...WITH ESSENTIALLY ZERO RISK OF MEASURABLE PRECIP AND SUSTAINED BREEZES STRUGGLING TO EXCEED 12 MPH AT MOST. HOWEVER...DUE TO FROST/FREEZE SENSITIVITIES THIS TIME OF YEAR...SKY COVER/CLOUD TRENDS HAVE TAKEN ON AN ENHANCED FORECAST FOCUS...GIVEN THE PRONOUNCED EFFECT OF CLOUD COVER ON TEMPERATURES. AS IT IS TURNING OUT...PARTS OF THE CWA ARE GOING TO FREEZE AND/OR FROST FAIRLY EFFICIENTLY THIS MORNING...WHILE OTHER PARTS OF THE AREA MAY ACTUALLY SEE MORE FAVORABLE CONDITIONS FOR FROST/FREEZE WEDNESDAY NIGHT INSTEAD. 07Z OBJECTIVE SURFACE ANALYSIS SHOWS THE LOCAL AREA POSITIONED BETWEEN A 1003 MILLIBAR LOW THAT HAS DEPARTED WELL EASTWARD INTO THE GREAT LAKES...AND A 1025 MILLIBAR HIGH CENTERED MUCH CLOSER TO HOME OVER THE NEB/KS/CO BORDER AREA. WITH THE PRESSURE GRADIENT CONTINUING TO RELAX...WEST-NORTHWEST BREEZES ACROSS MOST OF THIS CWA HAVE FINALLY EASED TO 10 MPH OR LESS...BUT WITH SLIGHTLY STRONGER SPEEDS STILL SHOWING UP NOW AND THEN MAINLY IN THE NORTHEAST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL THAT THE CWA IS POSITIONED ALMOST DIRECTLY UNDERNEATH A BROAD...SEVERELY POSITIVELY TILTED MID/UPPER LEVEL TROUGH AXIS EXTENDING IN A SOUTHWEST-NORTHEAST ORIENTATION FROM THE 4-CORNERS AREA THROUGH THE GREAT LAKES AND UP INTO EASTERN CANADA. ALONG THE SOUTHERN EDGE OF THIS TROUGH AXIS...A 105+ KT JET STREAK IS EVIDENT AT 300MB OVER THE KS/NEB BORDER. THE FOLLOWING PARAGRAPH FOCUSES SOLELY ON EXISTING FROST/FREEZE HEADLINES THIS MORNING...THE REAL HEADACHE THIS MORNING LIES WITH CLOUD COVER TRENDS PER IR AND 11-3.9 MICRON SATELLITE. ON A POSITIVE NOTE FOR CURRENT FROST/FREEZE HEADLINES...THE EXPANSIVE DECK OF LOW STRATUS THAT RULED MOST OF THE CWA ON TUESDAY CONTINUES TO STEADILY ERODE FROM NORTHWEST-TO-SOUTHEAST...WHICH MAKES IT NOW LOOK LIKE MUCH OF THE CWA SHOULD SEE AT LEAST A FEW HOURS OF CLEAR SKIES...POTENTIALLY ALLOWING FROST FORMATION TO COMMENCE. IN FACT...THIS PROCESS IS LIKELY ALREADY WELL-UNDERWAY IN/NEAR FAR WESTERN PORTIONS OF THE CWA...WHERE SITES SUCH AS LEXINGTON/MCCOOK HAVE ALREADY TUMBLED INTO THE LOW 30S THUS VERIFYING THE EXISTING FREEZE WARNING. HOWEVER...ON THE FLIP SIDE...PORTIONS OF THE ORIGINAL FROST ADVISORY ACROSS ROUGHLY THE EASTERN HALF OF THE CWA SEEMS TO BE FACING A GREATER OBSTACLE TO VERIFY...AS FOLLOWING SHORTLY BEHIND THE VACATING LOW STRATUS IS A SOUTHWARD-SINKING BAND OF MID LEVEL CLOUDS CENTERED BETWEEN 8-10K FEET...WHICH HAS ALREADY BRUSHED INTO THE FAR NORTHERN CWA...AND IS EXPECTED TO SLOWLY DROP SOUTHWARD TO AT LEAST ROUGHLY THE HIGHWAY 6 CORRIDOR BY SUNRISE. HOWEVER...THESE MID CLOUDS SHOULD HAVE LITTLE EFFECT ON EARLY MORNING TEMPERATURES ACROSS MOST OF THE SOUTHERN HALF TO ONE-THIRD OF THE CWA...WITH THESE AREAS LIKELY HEADED FOR SEVERAL HOURS OF CLEARING IN THE WAKE OF THE DEPARTING LOWER DECK. THE NET RESULT...AS IT CURRENTLY STANDS AT 09Z/4AM...IS THAT ADVISORIES/WARNINGS WERE CANCELLED FOR 5 COUNTIES NORTH OF INTERSTATE 80...WHILE AT LEAST FOR NOW WILL LET THE REMAINING 23 COUNTIES STAND AS-IS PER ORIGINAL ISSUANCE...AND TAKE ANOTHER LOOK FOR POSSIBLE UPDATES IN A FEW HOURS. TURNING TO OTHER ELEMENTS OF THE FORECAST...RIGHT OFF THE BAT DECIDED TO SLIP A SLIGHT CHANCE OF SPRINKLES INTO FAR NORTHERN AREAS UP AROUND ORD/GREELEY PRIOR TO SUNRISE TO ACCOUNT FOR A FEW WEAK RETURNS SHOWING UP ON RADAR UNDER THE INVADING MID-DECK...BUT THIS SHOULD BE VERY ISOLATED IN NATURE. BEYOND SUNRISE...ANTICIPATE A COOLISH BUT SEASONABLY PLEASANT DAY UNDER VARIABLE CLOUD COVER. ALOFT...THE AFOREMENTIONED ELONGATED MID LEVEL TROUGH AXIS WILL CONTINUE SLIPPING SOUTHWARD ACROSS THE REGION...AS A SHORTWAVE CURRENTLY WITHIN THE BASE OF THE TROUGH NEAR THE 4-CORNERS AREA GRADUALLY EJECTS EASTWARD ALONG THE KS/OK BORDER AS THE DAY WEARS ON. WHILE ANY SPOTTY RAIN FROM THIS DISTURBANCE SHOULD REMAIN WELL SOUTH OF THE LOCAL AREA...ESPECIALLY OUR KS ZONES COULD SEE A FAIR AMOUNT OF MID/UPPER LEVEL CLOUDS STREAMING EAST-NORTHEAST FROM THIS SYSTEM. MEANWHILE...THE ALREADY-PRESENT MID DECK SLIPPING INTO NORTHERN COUNTIES WILL CONTINUE TO SLOWLY SINK SOUTHWARD...AND IS EXPECTED TO PROVIDE A CLOUDY START TO THE DAY ACROSS THE MAJORITY OF NEB ZONES...BUT THEN ACCORDING TO 700 MILLIBAR RELATIVE HUMIDITY PROGS FROM THE RAP/NAM...SHOULD GRADUALLY FADE AWAY OR SCATTER OUT BY THE MID-LATE MORNING HOURS. SO...THE NET RESULT IS BEST PUT AS VARIABLE CLOUD COVER...AS NORTHERN AREAS SHOULD GENERALLY START OUT RATHER CLOUDY BUT SEE INCREASING SUN WITH TIME...WHILE SOUTHERN AREAS GENERALLY DO THE OPPOSITE AND SEE INCREASING CLOUDS WITH TIME. THESE CLOUD COVER TRENDS WILL BE TOUGH TO CAPTURE IN HOURLY FORECAST GRIDS...AND PLENTY OF UPDATES ARE LIKELY. OTHERWISE...AS THE CENTER OF THE SURFACE RIDGE AXIS SINKS SOUTH OF THE AREA TODAY...BREEZES WILL AVERAGE 10-12 MPH FROM THE WEST-NORTHWEST IN ALL AREAS. HIGH TEMPERATURES WERE ONLY TWEAKED SLIGHTLY PER A BLEND OF MET/MAV GUIDANCE AND RAP TEMPS...AND THUS WILL CONTINUE TO CALL FOR A REMARKABLY UNIFORM RANGE ACROSS THE CWA WITH ALL AREAS TOPPING OUT BETWEEN 56-59. FOR THIS EVENING/TONIGHT...THE MAIN STORY ALOFT IS THAT THE CURRENT SOUTHWEST-TO-NORTHEAST TROUGH AXIS WILL GRADUALLY BE REPLACED BY A SOUTHWEST-NORTHEAST ORIENTED SHORTWAVE RIDGE AXIS. THIS IS BECAUSE THE LOCAL AREA WILL BE IN BETWEEN TROUGHS...AS THE DISTURBANCE CENTERED OVER SOUTHERN KS AT SUNSET DEPARTS EASTWARD INTO MO...WHILE THE NEXT UPSTREAM TROUGH DROPPING SOUTHEAST TOWARD THE AREA ONLY REACHES AN AXIS FROM NORTHWEST CO TO NORTH DAKOTA BY SUNRISE THURSDAY. ALTHOUGH AM EXPECTING SKIES WEDNESDAY NIGHT AS A WHOLE TO AVERAGE CLEARER THAN THIS ONGOING NIGHT HAS BEEN...THERE IS AGAIN GOING TO BE VARIABLE CLOUD COVER EXCEPT THIS TIME SOLELY OF THE MID-UPPER VARIETY. FOR ONE...MAINLY SOUTHERN PARTS OF THE CWA WILL LIKELY START THE EVENING WITH LINGERING CLOUDS FROM THE DEPARTING DISTURBANCE...WHILE LATER IN THE NIGHT...MAINLY NORTHERN AREAS COULD SEE PASSING BATCHES OF CLOUDS OUT AHEAD OF THE APPROACHING UPSTREAM WAVE. MEANWHILE AT THE SURFACE...WINDS WILL REMAIN FAIRLY LIGHT AT SUSTAINED SPEEDS GENERALLY LESS THAN 8 MPH...BUT GRADUALLY TRANSITION FROM A SOUTHWESTERLY DIRECTION TO NORTHWESTERLY IN RESPONSE TO A SUBTLE PASSING TROUGH AXIS. AS FOR LOW TEMPS...ONCE AGAIN PASSING CLOUDS COULD POSE ISSUES...BUT FOR NOW STUCK VERY CLOSE TO A MET/MAV GUIDANCE BLEND...WHICH PUTS THE MAJORITY OF THE CWA DOWN BETWEEN 33-36 DEGREES...WITH THE TYPICALLY FAVORED DAWSON-TO-VALLEY COUNTY CORRIDOR MOST FAVORED TO SLIP SLIGHTLY BELOW FREEZING. OBVIOUSLY THESE LOWS ARE AGAIN SUPPORTIVE OF FROST AND/OR FREEZE DEVELOPMENT. HOWEVER...GIVEN THE ONGOING COMPLICATIONS/UNCERTAINTY THIS MORNING REGARDING LOW TEMPS...WILL HOLD OFF ON ANY WEDNESDAY NIGHT FROST ADVISORIES/FREEZE WARNINGS FOR NOW...NOT ONLY TO AVOID HEADLINE CONFUSION...BUT ALSO TO ALLOW DAY SHIFT TO IDENTIFY COUNTIES THAT COULD NOW BE RULED INELIGIBLE FROM FUTURE FROST/FREEZE HEADLINES BASED ON WHAT HAPPENS THIS MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 430 AM CDT WED OCT 16 2013 MAIN CONCERNS THIS FORECAST PERIOD LOOKS TO BE PRECIPITATION CHANCES ON FRIDAY. STARTING OUT THURSDAY MORNING WITH THE BIG PICTURE...THERE SHOULD BE A HIGH AMPLITUDE RIDGE JUST OFF THE PACIFIC U.S. AND CANADIAN COAST WITH A LONG WAVE TROUGH AND SEVERAL EMBEDDED SHORT WAVES SITUATED OVER MUCH OF THE CONUS. THIS PATTERN WILL GRADUALLY SHIFT EAST A BIT BUT THE CENTRAL PLAINS SHOULD STILL BE SITTING ON THE BACK SIDE OF THE UPPER TROUGH BY NEXT TUESDAY...PUTTING US IN NORTHWEST FLOW. AT THE SURFACE ON TUESDAY MORNING...A TROUGH OF LOW PRESSURE EXTENDING FROM LAKE SUPERIOR TO THE OKLAHOMA PANHANDLE SHOULD BE JUST ABOUT THROUGH THE CWA WITH A WIND SHIFT FROM SOUTHWEST TO NORTHWEST. THE COOLER AIR WILL LAG BEHIND THE TROUGH A WAYS AND THURSDAY SHOULD BE QUITE NICE...JUST A FEW DEGREES LOWER THAN SEASONAL NORMALS. THE NEXT IN THE PROGRESSION OF MID LEVEL SHORTWAVES NOTED ABOVE IS THEN SLATED TO APPROACH THE PLAINS FROM THE NORTHWEST THURSDAY NIGHT INTO FRIDAY. SEVERAL MODELS SHOW A SIMILAR SOLUTION IN TAKING ONE WAVE NORTH AND EAST OF US AND DIGGING ANOTHER WAVE TO OUR WEST AND THEN SOUTH ACROSS KANSAS. INTERESTING TO RUN A TIME HEIGHT SECTION COMPARING THE GRAND ISLAND AREA TO THE PHILLIPSBURG KANSAS AREA IN TERMS OF MID LEVEL FORCING. THE NAM IS ONLY PRODUCING 1-2 UBARS PER SEC OF OMEGA OVER KGRI AT 12Z FRIDAY WHILE AT KPHG IT IS GENERATING 10-12 UBARS PER SEC. THE GFS HAS SIMILAR RESULTS FOR OUR SOUTHERN CWA WITH THE ONLY DIFFERENCE BEING THE GFS HAS A LITTLE LESS LOW LEVEL MOISTURE TO WORK WITH AND MAY TAKE A WHILE TO SATURATE THE COLUMN...WHILE THE NAM IS SATURATED ALL THE WAY FROM NEAR THE SURFACE TO 300 MB. THE EC FORECAST SOUNDING IS SIMILAR TO THE GFS AS IT IS NOT QUITE SATURATED UP TO 700MB. NEITHER THE GFS OR EC IS SHOWING THE LOWER PORTION BECOMING SATURATED BETWEEN 12 AND 18Z FRIDAY BUT I AM A LITTLE CONCERNED OF THE SCENARIO WHERE SNOW FALLING FROM ABOVE MOISTENS AND COOLS THE LOWER COLUMN UNTIL IT REACHES SATURATION. IF THIS WERE TO OCCUR...WE COULD SEE A LITTLE SNOW FRIDAY MORNING IN THE CWA. WILL NOT INCLUDE SNOW IN THE GRIDS FOR NOW AS I ONLY HAVE LOW TEMPERATURES FRIDAY MORNING FORECASTED TO BE AROUND 37 OR 38 DEGREES IN THE KANSAS PART OF OUR CWA...BUT IT WILL BE WORTH KEEPING AN EYE ON THE NEXT COUPLE OF DAYS. BUMPED UP POPS IN THE SOUTHERN PART OF THE CWA FOR FRIDAY AND THESE WILL NEED TO BE RAISED EVEN MORE IF THE MODELS REMAIN CONSISTENT ON THE TRACK OF THE SHORT WAVE TROUGH. THE COOLER AIR WILL THEN MAKE IT INTO THE AREA THURSDAY NIGHT AND BY FRIDAY HIGHS SHOULD BE 5 TO 10 DEGREES COOLER THAN ON THURSDAY. BUT THE COOLER WEATHER WILL ONLY LAST A DAY AS SATURDAY THROUGH TUESDAY SHOULD AGAIN BE IN THE UPPER 50S NORTH TO THE MID 60S SOUTH. WILL LEAVE REST OF FORECAST DRY FOR NOW BUT NOT TOTALLY OUT OF THE QUESTION THAT ONE OR TWO DISTURBANCES RIDING DOWN THE NORTHWEST FLOW MAY GIVE US AT LEAST A SLIGHT CHANCE FOR ADDITIONAL PRECIPITATION. && .AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z THURSDAY MORNING) ISSUED AT 550 AM CDT WED OCT 16 2013 COMPARED TO THE PAST FEW DAYS...THE UPCOMING PERIOD WILL BE MARKED BY MUCH MORE TRANQUIL AVIATION WEATHER IN SOUTH CENTRAL NEBRASKA. DESPITE PASSING BATCHES OF MID LEVEL CLOUDS CENTERED NEAR/ABOVE 9000 FT...THERE IS HIGH CONFIDENCE IN VFR CONDITIONS THROUGHOUT...AND ESSENTIALLY ZERO RISK OF PRECIPITATION. AS FOR SURFACE WINDS...SPEEDS WILL AVERAGE AT/BELOW 11KT FROM THE WEST- NORTHWEST TODAY BEFORE BECOMING LIGHTER AND SOMEWHAT VARIABLE IN DIRECTION THIS EVENING/TONIGHT...WITH THE ADVERTISED DIRECTION OF 240 DEGREES AFTER 00Z REPRESENTING AN AVERAGE DIRECTION FOR THE NIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...WESELY SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
647 AM CDT WED OCT 16 2013 .UPDATE... ISSUED AT 646 AM CDT WED OCT 16 2013 LITTLE CHANGE IN THINKING FROM A FEW HOURS AGO...AS ONE DECK OF MID CLOUDS CONTINUES SINKING SOUTHWARD ACROSS THE NORTHERN CWA...WHILE MAINLY THINNER/HIGHER CIRRUS CONTINUES INCREASING INTO AREAS NEAR/SOUTH OF THE STATE LINE. IN BETWEEN...MOST PLACES BETWEEN I-80 AND THE STATE LINE ARE ESSENTIALLY CLEAR AT THIS TIME. ALTHOUGH LIGHT BUT STEADY BREEZES HAVE LIKELY PRECLUDED TRULY WIDESPREAD FROST DEVELOPMENT IN MANY AREAS...PRESENT INDICATIONS ARE THAT THE FROST/FREEZE HEADLINES ISSUED YESTERDAY WERE JUSTIFIED ACROSS MOST AFFECTED AREAS...WITH A FEW LOWS SO FAR THIS MORNING CONSISTING OF 31 AT LEXINGTON AIRPORT...32 AT RAVENNA...HOLDREGE AIRPORT AND 4WNW PLAINVILLE KS...AND 33 AT HASTINGS AIRPORT. WITH CLOUDS ON THE INCREASE...ITS BECOMING INCREASINGLY UNLIKELY THAT FROST WILL BE OBSERVED IN THE HAMILTON/YORK AND JEWELL/MITCHELL COUNTY AREAS...BUT GIVEN THAT TEMPS ARE AT LEAST IN THE BALLPARK OF SUPPORTING FROST AT THIS TIME WILL DEFER TO ONCOMING DAY SHIFT TO FORMALLY PUT THESE HEADLINES TO REST. ONCE ALL MORNING TEMPERATURE REPORTS COME IN...DECISIONS WILL ALSO BE MADE REGARDING WHICH ADDITIONAL COUNTIES BESIDES VALLEY/GREELEY ARE DEEMED INELIGIBLE FOR FUTURE FROST/FREEZE HEADLINES...AS WE WILL LIKELY BE ADDING AT LEAST A FEW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 430 AM CDT WED OCT 16 2013 COMPARED TO THE PAST 48 HOURS OF WIDESPREAD RAIN FOLLOWED BY FAIRLY STRONG NORTHWEST WINDS...THESE NEXT 24 HOURS ARE GOING TO BE A BENIGN CHANGE OF PACE...WITH ESSENTIALLY ZERO RISK OF MEASURABLE PRECIP AND SUSTAINED BREEZES STRUGGLING TO EXCEED 12 MPH AT MOST. HOWEVER...DUE TO FROST/FREEZE SENSITIVITIES THIS TIME OF YEAR...SKY COVER/CLOUD TRENDS HAVE TAKEN ON AN ENHANCED FORECAST FOCUS...GIVEN THE PRONOUNCED EFFECT OF CLOUD COVER ON TEMPERATURES. AS IT IS TURNING OUT...PARTS OF THE CWA ARE GOING TO FREEZE AND/OR FROST FAIRLY EFFICIENTLY THIS MORNING...WHILE OTHER PARTS OF THE AREA MAY ACTUALLY SEE MORE FAVORABLE CONDITIONS FOR FROST/FREEZE WEDNESDAY NIGHT INSTEAD. 07Z OBJECTIVE SURFACE ANALYSIS SHOWS THE LOCAL AREA POSITIONED BETWEEN A 1003 MILLIBAR LOW THAT HAS DEPARTED WELL EASTWARD INTO THE GREAT LAKES...AND A 1025 MILLIBAR HIGH CENTERED MUCH CLOSER TO HOME OVER THE NEB/KS/CO BORDER AREA. WITH THE PRESSURE GRADIENT CONTINUING TO RELAX...WEST-NORTHWEST BREEZES ACROSS MOST OF THIS CWA HAVE FINALLY EASED TO 10 MPH OR LESS...BUT WITH SLIGHTLY STRONGER SPEEDS STILL SHOWING UP NOW AND THEN MAINLY IN THE NORTHEAST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL THAT THE CWA IS POSITIONED ALMOST DIRECTLY UNDERNEATH A BROAD...SEVERELY POSITIVELY TILTED MID/UPPER LEVEL TROUGH AXIS EXTENDING IN A SOUTHWEST-NORTHEAST ORIENTATION FROM THE 4-CORNERS AREA THROUGH THE GREAT LAKES AND UP INTO EASTERN CANADA. ALONG THE SOUTHERN EDGE OF THIS TROUGH AXIS...A 105+ KT JET STREAK IS EVIDENT AT 300MB OVER THE KS/NEB BORDER. THE FOLLOWING PARAGRAPH FOCUSES SOLELY ON EXISTING FROST/FREEZE HEADLINES THIS MORNING...THE REAL HEADACHE THIS MORNING LIES WITH CLOUD COVER TRENDS PER IR AND 11-3.9 MICRON SATELLITE. ON A POSITIVE NOTE FOR CURRENT FROST/FREEZE HEADLINES...THE EXPANSIVE DECK OF LOW STRATUS THAT RULED MOST OF THE CWA ON TUESDAY CONTINUES TO STEADILY ERODE FROM NORTHWEST-TO-SOUTHEAST...WHICH MAKES IT NOW LOOK LIKE MUCH OF THE CWA SHOULD SEE AT LEAST A FEW HOURS OF CLEAR SKIES...POTENTIALLY ALLOWING FROST FORMATION TO COMMENCE. IN FACT...THIS PROCESS IS LIKELY ALREADY WELL-UNDERWAY IN/NEAR FAR WESTERN PORTIONS OF THE CWA...WHERE SITES SUCH AS LEXINGTON/MCCOOK HAVE ALREADY TUMBLED INTO THE LOW 30S THUS VERIFYING THE EXISTING FREEZE WARNING. HOWEVER...ON THE FLIP SIDE...PORTIONS OF THE ORIGINAL FROST ADVISORY ACROSS ROUGHLY THE EASTERN HALF OF THE CWA SEEMS TO BE FACING A GREATER OBSTACLE TO VERIFY...AS FOLLOWING SHORTLY BEHIND THE VACATING LOW STRATUS IS A SOUTHWARD-SINKING BAND OF MID LEVEL CLOUDS CENTERED BETWEEN 8-10K FEET...WHICH HAS ALREADY BRUSHED INTO THE FAR NORTHERN CWA...AND IS EXPECTED TO SLOWLY DROP SOUTHWARD TO AT LEAST ROUGHLY THE HIGHWAY 6 CORRIDOR BY SUNRISE. HOWEVER...THESE MID CLOUDS SHOULD HAVE LITTLE EFFECT ON EARLY MORNING TEMPERATURES ACROSS MOST OF THE SOUTHERN HALF TO ONE-THIRD OF THE CWA...WITH THESE AREAS LIKELY HEADED FOR SEVERAL HOURS OF CLEARING IN THE WAKE OF THE DEPARTING LOWER DECK. THE NET RESULT...AS IT CURRENTLY STANDS AT 09Z/4AM...IS THAT ADVISORIES/WARNINGS WERE CANCELLED FOR 5 COUNTIES NORTH OF INTERSTATE 80...WHILE AT LEAST FOR NOW WILL LET THE REMAINING 23 COUNTIES STAND AS-IS PER ORIGINAL ISSUANCE...AND TAKE ANOTHER LOOK FOR POSSIBLE UPDATES IN A FEW HOURS. TURNING TO OTHER ELEMENTS OF THE FORECAST...RIGHT OFF THE BAT DECIDED TO SLIP A SLIGHT CHANCE OF SPRINKLES INTO FAR NORTHERN AREAS UP AROUND ORD/GREELEY PRIOR TO SUNRISE TO ACCOUNT FOR A FEW WEAK RETURNS SHOWING UP ON RADAR UNDER THE INVADING MID-DECK...BUT THIS SHOULD BE VERY ISOLATED IN NATURE. BEYOND SUNRISE...ANTICIPATE A COOLISH BUT SEASONABLY PLEASANT DAY UNDER VARIABLE CLOUD COVER. ALOFT...THE AFOREMENTIONED ELONGATED MID LEVEL TROUGH AXIS WILL CONTINUE SLIPPING SOUTHWARD ACROSS THE REGION...AS A SHORTWAVE CURRENTLY WITHIN THE BASE OF THE TROUGH NEAR THE 4-CORNERS AREA GRADUALLY EJECTS EASTWARD ALONG THE KS/OK BORDER AS THE DAY WEARS ON. WHILE ANY SPOTTY RAIN FROM THIS DISTURBANCE SHOULD REMAIN WELL SOUTH OF THE LOCAL AREA...ESPECIALLY OUR KS ZONES COULD SEE A FAIR AMOUNT OF MID/UPPER LEVEL CLOUDS STREAMING EAST-NORTHEAST FROM THIS SYSTEM. MEANWHILE...THE ALREADY-PRESENT MID DECK SLIPPING INTO NORTHERN COUNTIES WILL CONTINUE TO SLOWLY SINK SOUTHWARD...AND IS EXPECTED TO PROVIDE A CLOUDY START TO THE DAY ACROSS THE MAJORITY OF NEB ZONES...BUT THEN ACCORDING TO 700 MILLIBAR RELATIVE HUMIDITY PROGS FROM THE RAP/NAM...SHOULD GRADUALLY FADE AWAY OR SCATTER OUT BY THE MID-LATE MORNING HOURS. SO...THE NET RESULT IS BEST PUT AS VARIABLE CLOUD COVER...AS NORTHERN AREAS SHOULD GENERALLY START OUT RATHER CLOUDY BUT SEE INCREASING SUN WITH TIME...WHILE SOUTHERN AREAS GENERALLY DO THE OPPOSITE AND SEE INCREASING CLOUDS WITH TIME. THESE CLOUD COVER TRENDS WILL BE TOUGH TO CAPTURE IN HOURLY FORECAST GRIDS...AND PLENTY OF UPDATES ARE LIKELY. OTHERWISE...AS THE CENTER OF THE SURFACE RIDGE AXIS SINKS SOUTH OF THE AREA TODAY...BREEZES WILL AVERAGE 10-12 MPH FROM THE WEST-NORTHWEST IN ALL AREAS. HIGH TEMPERATURES WERE ONLY TWEAKED SLIGHTLY PER A BLEND OF MET/MAV GUIDANCE AND RAP TEMPS...AND THUS WILL CONTINUE TO CALL FOR A REMARKABLY UNIFORM RANGE ACROSS THE CWA WITH ALL AREAS TOPPING OUT BETWEEN 56-59. FOR THIS EVENING/TONIGHT...THE MAIN STORY ALOFT IS THAT THE CURRENT SOUTHWEST-TO-NORTHEAST TROUGH AXIS WILL GRADUALLY BE REPLACED BY A SOUTHWEST-NORTHEAST ORIENTED SHORTWAVE RIDGE AXIS. THIS IS BECAUSE THE LOCAL AREA WILL BE IN BETWEEN TROUGHS...AS THE DISTURBANCE CENTERED OVER SOUTHERN KS AT SUNSET DEPARTS EASTWARD INTO MO...WHILE THE NEXT UPSTREAM TROUGH DROPPING SOUTHEAST TOWARD THE AREA ONLY REACHES AN AXIS FROM NORTHWEST CO TO NORTH DAKOTA BY SUNRISE THURSDAY. ALTHOUGH AM EXPECTING SKIES WEDNESDAY NIGHT AS A WHOLE TO AVERAGE CLEARER THAN THIS ONGOING NIGHT HAS BEEN...THERE IS AGAIN GOING TO BE VARIABLE CLOUD COVER EXCEPT THIS TIME SOLELY OF THE MID-UPPER VARIETY. FOR ONE...MAINLY SOUTHERN PARTS OF THE CWA WILL LIKELY START THE EVENING WITH LINGERING CLOUDS FROM THE DEPARTING DISTURBANCE...WHILE LATER IN THE NIGHT...MAINLY NORTHERN AREAS COULD SEE PASSING BATCHES OF CLOUDS OUT AHEAD OF THE APPROACHING UPSTREAM WAVE. MEANWHILE AT THE SURFACE...WINDS WILL REMAIN FAIRLY LIGHT AT SUSTAINED SPEEDS GENERALLY LESS THAN 8 MPH...BUT GRADUALLY TRANSITION FROM A SOUTHWESTERLY DIRECTION TO NORTHWESTERLY IN RESPONSE TO A SUBTLE PASSING TROUGH AXIS. AS FOR LOW TEMPS...ONCE AGAIN PASSING CLOUDS COULD POSE ISSUES...BUT FOR NOW STUCK VERY CLOSE TO A MET/MAV GUIDANCE BLEND...WHICH PUTS THE MAJORITY OF THE CWA DOWN BETWEEN 33-36 DEGREES...WITH THE TYPICALLY FAVORED DAWSON-TO-VALLEY COUNTY CORRIDOR MOST FAVORED TO SLIP SLIGHTLY BELOW FREEZING. OBVIOUSLY THESE LOWS ARE AGAIN SUPPORTIVE OF FROST AND/OR FREEZE DEVELOPMENT. HOWEVER...GIVEN THE ONGOING COMPLICATIONS/UNCERTAINTY THIS MORNING REGARDING LOW TEMPS...WILL HOLD OFF ON ANY WEDNESDAY NIGHT FROST ADVISORIES/FREEZE WARNINGS FOR NOW...NOT ONLY TO AVOID HEADLINE CONFUSION...BUT ALSO TO ALLOW DAY SHIFT TO IDENTIFY COUNTIES THAT COULD NOW BE RULED INELIGIBLE FROM FUTURE FROST/FREEZE HEADLINES BASED ON WHAT HAPPENS THIS MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 430 AM CDT WED OCT 16 2013 MAIN CONCERNS THIS FORECAST PERIOD LOOKS TO BE PRECIPITATION CHANCES ON FRIDAY. STARTING OUT THURSDAY MORNING WITH THE BIG PICTURE...THERE SHOULD BE A HIGH AMPLITUDE RIDGE JUST OFF THE PACIFIC U.S. AND CANADIAN COAST WITH A LONG WAVE TROUGH AND SEVERAL EMBEDDED SHORT WAVES SITUATED OVER MUCH OF THE CONUS. THIS PATTERN WILL GRADUALLY SHIFT EAST A BIT BUT THE CENTRAL PLAINS SHOULD STILL BE SITTING ON THE BACK SIDE OF THE UPPER TROUGH BY NEXT TUESDAY...PUTTING US IN NORTHWEST FLOW. AT THE SURFACE ON TUESDAY MORNING...A TROUGH OF LOW PRESSURE EXTENDING FROM LAKE SUPERIOR TO THE OKLAHOMA PANHANDLE SHOULD BE JUST ABOUT THROUGH THE CWA WITH A WIND SHIFT FROM SOUTHWEST TO NORTHWEST. THE COOLER AIR WILL LAG BEHIND THE TROUGH A WAYS AND THURSDAY SHOULD BE QUITE NICE...JUST A FEW DEGREES LOWER THAN SEASONAL NORMALS. THE NEXT IN THE PROGRESSION OF MID LEVEL SHORTWAVES NOTED ABOVE IS THEN SLATED TO APPROACH THE PLAINS FROM THE NORTHWEST THURSDAY NIGHT INTO FRIDAY. SEVERAL MODELS SHOW A SIMILAR SOLUTION IN TAKING ONE WAVE NORTH AND EAST OF US AND DIGGING ANOTHER WAVE TO OUR WEST AND THEN SOUTH ACROSS KANSAS. INTERESTING TO RUN A TIME HEIGHT SECTION COMPARING THE GRAND ISLAND AREA TO THE PHILLIPSBURG KANSAS AREA IN TERMS OF MID LEVEL FORCING. THE NAM IS ONLY PRODUCING 1-2 UBARS PER SEC OF OMEGA OVER KGRI AT 12Z FRIDAY WHILE AT KPHG IT IS GENERATING 10-12 UBARS PER SEC. THE GFS HAS SIMILAR RESULTS FOR OUR SOUTHERN CWA WITH THE ONLY DIFFERENCE BEING THE GFS HAS A LITTLE LESS LOW LEVEL MOISTURE TO WORK WITH AND MAY TAKE A WHILE TO SATURATE THE COLUMN...WHILE THE NAM IS SATURATED ALL THE WAY FROM NEAR THE SURFACE TO 300 MB. THE EC FORECAST SOUNDING IS SIMILAR TO THE GFS AS IT IS NOT QUITE SATURATED UP TO 700MB. NEITHER THE GFS OR EC IS SHOWING THE LOWER PORTION BECOMING SATURATED BETWEEN 12 AND 18Z FRIDAY BUT I AM A LITTLE CONCERNED OF THE SCENARIO WHERE SNOW FALLING FROM ABOVE MOISTENS AND COOLS THE LOWER COLUMN UNTIL IT REACHES SATURATION. IF THIS WERE TO OCCUR...WE COULD SEE A LITTLE SNOW FRIDAY MORNING IN THE CWA. WILL NOT INCLUDE SNOW IN THE GRIDS FOR NOW AS I ONLY HAVE LOW TEMPERATURES FRIDAY MORNING FORECASTED TO BE AROUND 37 OR 38 DEGREES IN THE KANSAS PART OF OUR CWA...BUT IT WILL BE WORTH KEEPING AN EYE ON THE NEXT COUPLE OF DAYS. BUMPED UP POPS IN THE SOUTHERN PART OF THE CWA FOR FRIDAY AND THESE WILL NEED TO BE RAISED EVEN MORE IF THE MODELS REMAIN CONSISTENT ON THE TRACK OF THE SHORT WAVE TROUGH. THE COOLER AIR WILL THEN MAKE IT INTO THE AREA THURSDAY NIGHT AND BY FRIDAY HIGHS SHOULD BE 5 TO 10 DEGREES COOLER THAN ON THURSDAY. BUT THE COOLER WEATHER WILL ONLY LAST A DAY AS SATURDAY THROUGH TUESDAY SHOULD AGAIN BE IN THE UPPER 50S NORTH TO THE MID 60S SOUTH. WILL LEAVE REST OF FORECAST DRY FOR NOW BUT NOT TOTALLY OUT OF THE QUESTION THAT ONE OR TWO DISTURBANCES RIDING DOWN THE NORTHWEST FLOW MAY GIVE US AT LEAST A SLIGHT CHANCE FOR ADDITIONAL PRECIPITATION. && .AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z THURSDAY MORNING) ISSUED AT 550 AM CDT WED OCT 16 2013 COMPARED TO THE PAST FEW DAYS...THE UPCOMING PERIOD WILL BE MARKED BY MUCH MORE TRANQUIL AVIATION WEATHER IN SOUTH CENTRAL NEBRASKA. DESPITE PASSING BATCHES OF MID LEVEL CLOUDS CENTERED NEAR/ABOVE 9000 FT...THERE IS HIGH CONFIDENCE IN VFR CONDITIONS THROUGHOUT...AND ESSENTIALLY ZERO RISK OF PRECIPITATION. AS FOR SURFACE WINDS...SPEEDS WILL AVERAGE AT/BELOW 11KT FROM THE WEST- NORTHWEST TODAY BEFORE BECOMING LIGHTER AND SOMEWHAT VARIABLE IN DIRECTION THIS EVENING/TONIGHT...WITH THE ADVERTISED DIRECTION OF 240 DEGREES AFTER 00Z REPRESENTING AN AVERAGE DIRECTION FOR THE NIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR NEZ062>064- 075>077-085>087. FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR NEZ060-061- 072>074-082>084. KS...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ007-019. FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR KSZ005-006-017- 018. && $$ UPDATE...PFANNKUCH SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
550 AM CDT WED OCT 16 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 430 AM CDT WED OCT 16 2013 COMPARED TO THE PAST 48 HOURS OF WIDESPREAD RAIN FOLLOWED BY FAIRLY STRONG NORTHWEST WINDS...THESE NEXT 24 HOURS ARE GOING TO BE A BENIGN CHANGE OF PACE...WITH ESSENTIALLY ZERO RISK OF MEASURABLE PRECIP AND SUSTAINED BREEZES STRUGGLING TO EXCEED 12 MPH AT MOST. HOWEVER...DUE TO FROST/FREEZE SENSITIVITIES THIS TIME OF YEAR...SKY COVER/CLOUD TRENDS HAVE TAKEN ON AN ENHANCED FORECAST FOCUS...GIVEN THE PRONOUNCED EFFECT OF CLOUD COVER ON TEMPERATURES. AS IT IS TURNING OUT...PARTS OF THE CWA ARE GOING TO FREEZE AND/OR FROST FAIRLY EFFICIENTLY THIS MORNING...WHILE OTHER PARTS OF THE AREA MAY ACTUALLY SEE MORE FAVORABLE CONDITIONS FOR FROST/FREEZE WEDNESDAY NIGHT INSTEAD. 07Z OBJECTIVE SURFACE ANALYSIS SHOWS THE LOCAL AREA POSITIONED BETWEEN A 1003 MILLIBAR LOW THAT HAS DEPARTED WELL EASTWARD INTO THE GREAT LAKES...AND A 1025 MILLIBAR HIGH CENTERED MUCH CLOSER TO HOME OVER THE NEB/KS/CO BORDER AREA. WITH THE PRESSURE GRADIENT CONTINUING TO RELAX...WEST-NORTHWEST BREEZES ACROSS MOST OF THIS CWA HAVE FINALLY EASED TO 10 MPH OR LESS...BUT WITH SLIGHTLY STRONGER SPEEDS STILL SHOWING UP NOW AND THEN MAINLY IN THE NORTHEAST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL THAT THE CWA IS POSITIONED ALMOST DIRECTLY UNDERNEATH A BROAD...SEVERELY POSITIVELY TILTED MID/UPPER LEVEL TROUGH AXIS EXTENDING IN A SOUTHWEST-NORTHEAST ORIENTATION FROM THE 4-CORNERS AREA THROUGH THE GREAT LAKES AND UP INTO EASTERN CANADA. ALONG THE SOUTHERN EDGE OF THIS TROUGH AXIS...A 105+ KT JET STREAK IS EVIDENT AT 300MB OVER THE KS/NEB BORDER. THE FOLLOWING PARAGRAPH FOCUSES SOLELY ON EXISTING FROST/FREEZE HEADLINES THIS MORNING...THE REAL HEADACHE THIS MORNING LIES WITH CLOUD COVER TRENDS PER IR AND 11-3.9 MICRON SATELLITE. ON A POSITIVE NOTE FOR CURRENT FROST/FREEZE HEADLINES...THE EXPANSIVE DECK OF LOW STRATUS THAT RULED MOST OF THE CWA ON TUESDAY CONTINUES TO STEADILY ERODE FROM NORTHWEST-TO-SOUTHEAST...WHICH MAKES IT NOW LOOK LIKE MUCH OF THE CWA SHOULD SEE AT LEAST A FEW HOURS OF CLEAR SKIES...POTENTIALLY ALLOWING FROST FORMATION TO COMMENCE. IN FACT...THIS PROCESS IS LIKELY ALREADY WELL-UNDERWAY IN/NEAR FAR WESTERN PORTIONS OF THE CWA...WHERE SITES SUCH AS LEXINGTON/MCCOOK HAVE ALREADY TUMBLED INTO THE LOW 30S THUS VERIFYING THE EXISTING FREEZE WARNING. HOWEVER...ON THE FLIP SIDE...PORTIONS OF THE ORIGINAL FROST ADVISORY ACROSS ROUGHLY THE EASTERN HALF OF THE CWA SEEMS TO BE FACING A GREATER OBSTACLE TO VERIFY...AS FOLLOWING SHORTLY BEHIND THE VACATING LOW STRATUS IS A SOUTHWARD-SINKING BAND OF MID LEVEL CLOUDS CENTERED BETWEEN 8-10K FEET...WHICH HAS ALREADY BRUSHED INTO THE FAR NORTHERN CWA...AND IS EXPECTED TO SLOWLY DROP SOUTHWARD TO AT LEAST ROUGHLY THE HIGHWAY 6 CORRIDOR BY SUNRISE. HOWEVER...THESE MID CLOUDS SHOULD HAVE LITTLE EFFECT ON EARLY MORNING TEMPERATURES ACROSS MOST OF THE SOUTHERN HALF TO ONE-THIRD OF THE CWA...WITH THESE AREAS LIKELY HEADED FOR SEVERAL HOURS OF CLEARING IN THE WAKE OF THE DEPARTING LOWER DECK. THE NET RESULT...AS IT CURRENTLY STANDS AT 09Z/4AM...IS THAT ADVISORIES/WARNINGS WERE CANCELLED FOR 5 COUNTIES NORTH OF INTERSTATE 80...WHILE AT LEAST FOR NOW WILL LET THE REMAINING 23 COUNTIES STAND AS-IS PER ORIGINAL ISSUANCE...AND TAKE ANOTHER LOOK FOR POSSIBLE UPDATES IN A FEW HOURS. TURNING TO OTHER ELEMENTS OF THE FORECAST...RIGHT OFF THE BAT DECIDED TO SLIP A SLIGHT CHANCE OF SPRINKLES INTO FAR NORTHERN AREAS UP AROUND ORD/GREELEY PRIOR TO SUNRISE TO ACCOUNT FOR A FEW WEAK RETURNS SHOWING UP ON RADAR UNDER THE INVADING MID-DECK...BUT THIS SHOULD BE VERY ISOLATED IN NATURE. BEYOND SUNRISE...ANTICIPATE A COOLISH BUT SEASONABLY PLEASANT DAY UNDER VARIABLE CLOUD COVER. ALOFT...THE AFOREMENTIONED ELONGATED MID LEVEL TROUGH AXIS WILL CONTINUE SLIPPING SOUTHWARD ACROSS THE REGION...AS A SHORTWAVE CURRENTLY WITHIN THE BASE OF THE TROUGH NEAR THE 4-CORNERS AREA GRADUALLY EJECTS EASTWARD ALONG THE KS/OK BORDER AS THE DAY WEARS ON. WHILE ANY SPOTTY RAIN FROM THIS DISTURBANCE SHOULD REMAIN WELL SOUTH OF THE LOCAL AREA...ESPECIALLY OUR KS ZONES COULD SEE A FAIR AMOUNT OF MID/UPPER LEVEL CLOUDS STREAMING EAST-NORTHEAST FROM THIS SYSTEM. MEANWHILE...THE ALREADY-PRESENT MID DECK SLIPPING INTO NORTHERN COUNTIES WILL CONTINUE TO SLOWLY SINK SOUTHWARD...AND IS EXPECTED TO PROVIDE A CLOUDY START TO THE DAY ACROSS THE MAJORITY OF NEB ZONES...BUT THEN ACCORDING TO 700 MILLIBAR RELATIVE HUMIDITY PROGS FROM THE RAP/NAM...SHOULD GRADUALLY FADE AWAY OR SCATTER OUT BY THE MID-LATE MORNING HOURS. SO...THE NET RESULT IS BEST PUT AS VARIABLE CLOUD COVER...AS NORTHERN AREAS SHOULD GENERALLY START OUT RATHER CLOUDY BUT SEE INCREASING SUN WITH TIME...WHILE SOUTHERN AREAS GENERALLY DO THE OPPOSITE AND SEE INCREASING CLOUDS WITH TIME. THESE CLOUD COVER TRENDS WILL BE TOUGH TO CAPTURE IN HOURLY FORECAST GRIDS...AND PLENTY OF UPDATES ARE LIKELY. OTHERWISE...AS THE CENTER OF THE SURFACE RIDGE AXIS SINKS SOUTH OF THE AREA TODAY...BREEZES WILL AVERAGE 10-12 MPH FROM THE WEST-NORTHWEST IN ALL AREAS. HIGH TEMPERATURES WERE ONLY TWEAKED SLIGHTLY PER A BLEND OF MET/MAV GUIDANCE AND RAP TEMPS...AND THUS WILL CONTINUE TO CALL FOR A REMARKABLY UNIFORM RANGE ACROSS THE CWA WITH ALL AREAS TOPPING OUT BETWEEN 56-59. FOR THIS EVENING/TONIGHT...THE MAIN STORY ALOFT IS THAT THE CURRENT SOUTHWEST-TO-NORTHEAST TROUGH AXIS WILL GRADUALLY BE REPLACED BY A SOUTHWEST-NORTHEAST ORIENTED SHORTWAVE RIDGE AXIS. THIS IS BECAUSE THE LOCAL AREA WILL BE IN BETWEEN TROUGHS...AS THE DISTURBANCE CENTERED OVER SOUTHERN KS AT SUNSET DEPARTS EASTWARD INTO MO...WHILE THE NEXT UPSTREAM TROUGH DROPPING SOUTHEAST TOWARD THE AREA ONLY REACHES AN AXIS FROM NORTHWEST CO TO NORTH DAKOTA BY SUNRISE THURSDAY. ALTHOUGH AM EXPECTING SKIES WEDNESDAY NIGHT AS A WHOLE TO AVERAGE CLEARER THAN THIS ONGOING NIGHT HAS BEEN...THERE IS AGAIN GOING TO BE VARIABLE CLOUD COVER EXCEPT THIS TIME SOLELY OF THE MID-UPPER VARIETY. FOR ONE...MAINLY SOUTHERN PARTS OF THE CWA WILL LIKELY START THE EVENING WITH LINGERING CLOUDS FROM THE DEPARTING DISTURBANCE...WHILE LATER IN THE NIGHT...MAINLY NORTHERN AREAS COULD SEE PASSING BATCHES OF CLOUDS OUT AHEAD OF THE APPROACHING UPSTREAM WAVE. MEANWHILE AT THE SURFACE...WINDS WILL REMAIN FAIRLY LIGHT AT SUSTAINED SPEEDS GENERALLY LESS THAN 8 MPH...BUT GRADUALLY TRANSITION FROM A SOUTHWESTERLY DIRECTION TO NORTHWESTERLY IN RESPONSE TO A SUBTLE PASSING TROUGH AXIS. AS FOR LOW TEMPS...ONCE AGAIN PASSING CLOUDS COULD POSE ISSUES...BUT FOR NOW STUCK VERY CLOSE TO A MET/MAV GUIDANCE BLEND...WHICH PUTS THE MAJORITY OF THE CWA DOWN BETWEEN 33-36 DEGREES...WITH THE TYPICALLY FAVORED DAWSON-TO-VALLEY COUNTY CORRIDOR MOST FAVORED TO SLIP SLIGHTLY BELOW FREEZING. OBVIOUSLY THESE LOWS ARE AGAIN SUPPORTIVE OF FROST AND/OR FREEZE DEVELOPMENT. HOWEVER...GIVEN THE ONGOING COMPLICATIONS/UNCERTAINTY THIS MORNING REGARDING LOW TEMPS...WILL HOLD OFF ON ANY WEDNESDAY NIGHT FROST ADVISORIES/FREEZE WARNINGS FOR NOW...NOT ONLY TO AVOID HEADLINE CONFUSION...BUT ALSO TO ALLOW DAY SHIFT TO IDENTIFY COUNTIES THAT COULD NOW BE RULED INELIGIBLE FROM FUTURE FROST/FREEZE HEADLINES BASED ON WHAT HAPPENS THIS MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 430 AM CDT WED OCT 16 2013 MAIN CONCERNS THIS FORECAST PERIOD LOOKS TO BE PRECIPITATION CHANCES ON FRIDAY. STARTING OUT THURSDAY MORNING WITH THE BIG PICTURE...THERE SHOULD BE A HIGH AMPLITUDE RIDGE JUST OFF THE PACIFIC U.S. AND CANADIAN COAST WITH A LONG WAVE TROUGH AND SEVERAL EMBEDDED SHORT WAVES SITUATED OVER MUCH OF THE CONUS. THIS PATTERN WILL GRADUALLY SHIFT EAST A BIT BUT THE CENTRAL PLAINS SHOULD STILL BE SITTING ON THE BACK SIDE OF THE UPPER TROUGH BY NEXT TUESDAY...PUTTING US IN NORTHWEST FLOW. AT THE SURFACE ON TUESDAY MORNING...A TROUGH OF LOW PRESSURE EXTENDING FROM LAKE SUPERIOR TO THE OKLAHOMA PANHANDLE SHOULD BE JUST ABOUT THROUGH THE CWA WITH A WIND SHIFT FROM SOUTHWEST TO NORTHWEST. THE COOLER AIR WILL LAG BEHIND THE TROUGH A WAYS AND THURSDAY SHOULD BE QUITE NICE...JUST A FEW DEGREES LOWER THAN SEASONAL NORMALS. THE NEXT IN THE PROGRESSION OF MID LEVEL SHORTWAVES NOTED ABOVE IS THEN SLATED TO APPROACH THE PLAINS FROM THE NORTHWEST THURSDAY NIGHT INTO FRIDAY. SEVERAL MODELS SHOW A SIMILAR SOLUTION IN TAKING ONE WAVE NORTH AND EAST OF US AND DIGGING ANOTHER WAVE TO OUR WEST AND THEN SOUTH ACROSS KANSAS. INTERESTING TO RUN A TIME HEIGHT SECTION COMPARING THE GRAND ISLAND AREA TO THE PHILLIPSBURG KANSAS AREA IN TERMS OF MID LEVEL FORCING. THE NAM IS ONLY PRODUCING 1-2 UBARS PER SEC OF OMEGA OVER KGRI AT 12Z FRIDAY WHILE AT KPHG IT IS GENERATING 10-12 UBARS PER SEC. THE GFS HAS SIMILAR RESULTS FOR OUR SOUTHERN CWA WITH THE ONLY DIFFERENCE BEING THE GFS HAS A LITTLE LESS LOW LEVEL MOISTURE TO WORK WITH AND MAY TAKE A WHILE TO SATURATE THE COLUMN...WHILE THE NAM IS SATURATED ALL THE WAY FROM NEAR THE SURFACE TO 300 MB. THE EC FORECAST SOUNDING IS SIMILAR TO THE GFS AS IT IS NOT QUITE SATURATED UP TO 700MB. NEITHER THE GFS OR EC IS SHOWING THE LOWER PORTION BECOMING SATURATED BETWEEN 12 AND 18Z FRIDAY BUT I AM A LITTLE CONCERNED OF THE SCENARIO WHERE SNOW FALLING FROM ABOVE MOISTENS AND COOLS THE LOWER COLUMN UNTIL IT REACHES SATURATION. IF THIS WERE TO OCCUR...WE COULD SEE A LITTLE SNOW FRIDAY MORNING IN THE CWA. WILL NOT INCLUDE SNOW IN THE GRIDS FOR NOW AS I ONLY HAVE LOW TEMPERATURES FRIDAY MORNING FORECASTED TO BE AROUND 37 OR 38 DEGREES IN THE KANSAS PART OF OUR CWA...BUT IT WILL BE WORTH KEEPING AN EYE ON THE NEXT COUPLE OF DAYS. BUMPED UP POPS IN THE SOUTHERN PART OF THE CWA FOR FRIDAY AND THESE WILL NEED TO BE RAISED EVEN MORE IF THE MODELS REMAIN CONSISTENT ON THE TRACK OF THE SHORT WAVE TROUGH. THE COOLER AIR WILL THEN MAKE IT INTO THE AREA THURSDAY NIGHT AND BY FRIDAY HIGHS SHOULD BE 5 TO 10 DEGREES COOLER THAN ON THURSDAY. BUT THE COOLER WEATHER WILL ONLY LAST A DAY AS SATURDAY THROUGH TUESDAY SHOULD AGAIN BE IN THE UPPER 50S NORTH TO THE MID 60S SOUTH. WILL LEAVE REST OF FORECAST DRY FOR NOW BUT NOT TOTALLY OUT OF THE QUESTION THAT ONE OR TWO DISTURBANCES RIDING DOWN THE NORTHWEST FLOW MAY GIVE US AT LEAST A SLIGHT CHANCE FOR ADDITIONAL PRECIPITATION. && .AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z THURSDAY MORNING) ISSUED AT 550 AM CDT WED OCT 16 2013 COMPARED TO THE PAST FEW DAYS...THE UPCOMING PERIOD WILL BE MARKED BY MUCH MORE TRANQUIL AVIATION WEATHER IN SOUTH CENTRAL NEBRASKA. DESPITE PASSING BATCHES OF MID LEVEL CLOUDS CENTERED NEAR/ABOVE 9000 FT...THERE IS HIGH CONFIDENCE IN VFR CONDITIONS THROUGHOUT...AND ESSENTIALLY ZERO RISK OF PRECIPITATION. AS FOR SURFACE WINDS...SPEEDS WILL AVERAGE AT/BELOW 11KT FROM THE WEST- NORTHWEST TODAY BEFORE BECOMING LIGHTER AND SOMEWHAT VARIABLE IN DIRECTION THIS EVENING/TONIGHT...WITH THE ADVERTISED DIRECTION OF 240 DEGREES AFTER 00Z REPRESENTING AN AVERAGE DIRECTION FOR THE NIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR NEZ062>064- 075>077-085>087. FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR NEZ060-061- 072>074-082>084. KS...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ007-019. FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR KSZ005-006-017- 018. && $$ SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1026 AM CDT WED OCT 16 2013 .DISCUSSION... A COLD FRONT STRETCHES FROM CENTRAL KENTUCKY THROUGH TUPELO INTO THE LOUISIANA. POST FRONTAL RAIN COVERS A GOOD POSITION OF THE MIDSOUTH INCLUDING MOST OF WEST TENNESSEE...NORTH MISSISSIPPI AND EAST CENTRAL ARKANSAS. RAIN HAS ENDED ACROSS MOST OF NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL. MUCH COOLER AIR IS MOVING IN BEHIND THE FRONT WITH TEMPS IN THE MID AND UPPER 50S BEHIND THE FRONT. STILL MILD AHEAD OF THE FRONT WITH TEMPS IN THE MID AND UPPER 60S ACROSS NORTHEAST MISSISSIPPI. GIVEN THE AREAL COVERAGE ATTM AND THE LATEST HRRR HAVE UPPED POPS ACROSS MUCH THE SE HALF OF THE FORECAST AREA FOR THIS AFTERNOON. SJM && PREV DISCUSSION... /ISSUED 248 AM CDT WED OCT 16 2013/ A COLD FRONT CURRENTLY STRETCHES FROM NEAR EVANSVILLE INDIANA TO PINE BLUFF ARKANSAS. A LARGE SHIELD OF RAIN IS PUSHING NORTHEAST ALONG THE FRONT. THE NORTHERN EDGE OF THE RAIN IS FURTHER NORTH THAN WHAT THE GFS AND NAM INITIALIZED WITH THUS FOR THIS MORNINGS FORECAST HAVE LEANED TOWARD THE LATEST HRRR RUN. THUS EXPECT RAIN TO CONTINUE TO FALL OVER AT LEAST THE NORTHWEST HALF OF THE CWA...MAINLY NORTHWEST OF A LINE FROM CLARKSDALE MISSISSIPPI TO JACKSON TENNESSEE THROUGH 10 AM. THEREAFTER...EXPECT RAIN TO GRADUALLY SHIFT SOUTHEAST AS THE DAY PROGRESSES. RAIN AND CLOUDS WILL KEEP TEMPERATURES COOL WITH A LOT OF LOCATIONS HAVING TEMPERATURES HOLD STEADY THROUGHOUT THE DAY FROM WHAT THEIR MORNING LOWS ARE. TONIGHT...EXPECT FRONT TO BE LOCATED ACROSS NORTHEAST MISSISSIPPI. MODELS INDICATING ANOTHER WEAK LOW PRESSURE CENTER DEVELOPING ALONG THE FRONT AS A SHORTWAVE MOVES INTO NORTHEAST ARKANSAS THIS EVENING. RAIN WILL SPREAD BACK NORTHWARD. ALTHOUGH A LOT OF THE PRECIPITATION WILL FALL AS VERY LIGHT RAIN OR POSSIBLY DRIZZLE SO EXPECT RAINFALL AMOUNTS TO BE ON THE LIGHT SIDE. LOWS WILL BE IN THE UPPER 40S TO UPPER 50S. THURSDAY...SHORTWAVE WILL FINALLY PUSH THE FRONT EAST OF THE AREA. EXPECT LIGHT RAIN/DRIZZLE AND CLOUDS TO REMAIN AROUND AT LEAST EASTERN PORTIONS OF THE MIDSOUTH IN THE MORNING. CONDITIONS WILL QUICKLY IMPROVE DURING THE AFTERNOON HOURS WITH A LOT OF LOCATIONS SEEING SUNSHINE BY THE END OF THE DAY. EXPECT HIGHS IN THE MID TO UPPER 60S. THURSDAY NIGHT INTO FRIDAY...SFC HIGH PRESSURE WILL BUILD OVER THE MIDSOUTH. MOSTLY CLEAR SKIES AND LIGHT WINDS WILL ALLOW LOWS TO DROP DOWN INTO THE 40S ACROSS THE ENTIRE CWA. WOULD NOT BE SURPRISED TO SEE A FEW UPPER 30 READINGS ALONG THE TENNESSEE RIVER. FRIDAY NIGHT INTO SATURDAY...MODELS ARE TRENDING TOWARD A DRIER FORECAST DURING THIS TIME FRAME. LOOKS LIKE THE LOW PRESSURE SYSTEM THAT DEVELOPS ALONG THE GULF COAST WILL BE FAR ENOUGH SOUTH TO KEEP RAIN FROM SPREADING BACK INTO THE AREA. CAN/T RULE OUT THE NORTHERN EDGE OF RAIN SKIRTING AREAS IN TALLAHATCHIE TO MONROE COUNTIES IN MISSISSIPPI ON SATURDAY THUS HAVE LEFT SMALL POPS. IN ADDITION...THERE WILL BE A REINFORCING COLD FRONT THAT MOVES INTO THE AREA LATE FRIDAY NIGHT INTO SATURDAY FROM THE NORTH. GFS SHOWS THE FRONT MOVING THROUGH DRY WHILE THE ECMWF SHOWS VERY LIGHT QPF OVER THE AREA. FOR NOW HAVE JUST KEPT 20 POPS ACROSS THE ENTIRE CWA BUT WOULD NOT BE SURPRISED IF THE DAY SHIFT WILL BE ABLE TO REMOVE CHANCES. HIGH PRESSURE WILL SETTLE BACK OVER THE CWA FOR THE LATTER PART OF THE WEEKEND INTO EARLY NEXT WEEK. EXPECT SUNDAY NIGHT TO BE ANOTHER CHILLY NIGHT WITH SEVERAL LOCATIONS ACROSS WEST TENNESSEE AND POSSIBLY NORTHEAST MISSISSIPPI GETTING DOWN INTO THE UPPER 30S. ANOTHER COLD FRONT OR LOW PRESSURE SYSTEM MAY AFFECT THE MIDSOUTH MONDAY NIGHT INTO TUESDAY. GFS AND ECMWF HAVE DIFFERENT SOLUTIONS WITH THE ECMWF BEING DRIER. FOR NOW HAVE ADDED 20 POPS FOR TUESDAY. KRM && .AVIATION... 12Z TAF CYCLE LIGHT RAIN CONTINUES TO FALL OVER PORTIONS OF THE FORECAST AREA AND WILL CONTINUE TO MOVE ACROSS THE FORECAST AREA DURING MUCH OF THE FORECAST PERIOD. CEILINGS WILL BEGIN TO IMPROVE AFTER SUNRISE BUT LIKELY REMAIN MVFR AT ALL SITES WITH THE EXCEPTION OF JBR WHERE VFR CONDITIONS SHOULD PREVAIL. WINDS WILL SHIFT FROM THE NORTH...INCREASING TO AROUND 10 KTS TODAY...DIMINISHING SLIGHTLY TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... MEM 63 55 69 47 / 80 30 20 10 MKL 62 54 66 40 / 90 30 20 10 JBR 65 49 67 42 / 30 20 10 10 TUP 69 57 67 47 / 90 50 30 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
628 AM CDT WED OCT 16 2013 .UPDATE...AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 248 AM CDT WED OCT 16 2013/ DISCUSSION... A COLD FRONT CURRENTLY STRETCHES FROM NEAR EVANSVILLE INDIANA TO PINE BLUFF ARKANSAS. A LARGE SHIELD OF RAIN IS PUSHING NORTHEAST ALONG THE FRONT. THE NORTHERN EDGE OF THE RAIN IS FURTHER NORTH THAN WHAT THE GFS AND NAM INITIALIZED WITH THUS FOR THIS MORNINGS FORECAST HAVE LEANED TOWARD THE LATEST HRRR RUN. THUS EXPECT RAIN TO CONTINUE TO FALL OVER AT LEAST THE NORTHWEST HALF OF THE CWA...MAINLY NORTHWEST OF A LINE FROM CLARKSDALE MISSISSIPPI TO JACKSON TENNESSEE THROUGH 10 AM. THEREAFTER...EXPECT RAIN TO GRADUALLY SHIFT SOUTHEAST AS THE DAY PROGRESSES. RAIN AND CLOUDS WILL KEEP TEMPERATURES COOL WITH A LOT OF LOCATIONS HAVING TEMPERATURES HOLD STEADY THROUGHOUT THE DAY FROM WHAT THEIR MORNING LOWS ARE. TONIGHT...EXPECT FRONT TO BE LOCATED ACROSS NORTHEAST MISSISSIPPI. MODELS INDICATING ANOTHER WEAK LOW PRESSURE CENTER DEVELOPING ALONG THE FRONT AS A SHORTWAVE MOVES INTO NORTHEAST ARKANSAS THIS EVENING. RAIN WILL SPREAD BACK NORTHWARD. ALTHOUGH A LOT OF THE PRECIPITATION WILL FALL AS VERY LIGHT RAIN OR POSSIBLY DRIZZLE SO EXPECT RAINFALL AMOUNTS TO BE ON THE LIGHT SIDE. LOWS WILL BE IN THE UPPER 40S TO UPPER 50S. THURSDAY...SHORTWAVE WILL FINALLY PUSH THE FRONT EAST OF THE AREA. EXPECT LIGHT RAIN/DRIZZLE AND CLOUDS TO REMAIN AROUND AT LEAST EASTERN PORTIONS OF THE MIDSOUTH IN THE MORNING. CONDITIONS WILL QUICKLY IMPROVE DURING THE AFTERNOON HOURS WITH A LOT OF LOCATIONS SEEING SUNSHINE BY THE END OF THE DAY. EXPECT HIGHS IN THE MID TO UPPER 60S. THURSDAY NIGHT INTO FRIDAY...SFC HIGH PRESSURE WILL BUILD OVER THE MIDSOUTH. MOSTLY CLEAR SKIES AND LIGHT WINDS WILL ALLOW LOWS TO DROP DOWN INTO THE 40S ACROSS THE ENTIRE CWA. WOULD NOT BE SURPRISED TO SEE A FEW UPPER 30 READINGS ALONG THE TENNESSEE RIVER. FRIDAY NIGHT INTO SATURDAY...MODELS ARE TRENDING TOWARD A DRIER FORECAST DURING THIS TIME FRAME. LOOKS LIKE THE LOW PRESSURE SYSTEM THAT DEVELOPS ALONG THE GULF COAST WILL BE FAR ENOUGH SOUTH TO KEEP RAIN FROM SPREADING BACK INTO THE AREA. CAN/T RULE OUT THE NORTHERN EDGE OF RAIN SKIRTING AREAS IN TALLAHATCHIE TO MONROE COUNTIES IN MISSISSIPPI ON SATURDAY THUS HAVE LEFT SMALL POPS. IN ADDITION...THERE WILL BE A REINFORCING COLD FRONT THAT MOVES INTO THE AREA LATE FRIDAY NIGHT INTO SATURDAY FROM THE NORTH. GFS SHOWS THE FRONT MOVING THROUGH DRY WHILE THE ECMWF SHOWS VERY LIGHT QPF OVER THE AREA. FOR NOW HAVE JUST KEPT 20 POPS ACROSS THE ENTIRE CWA BUT WOULD NOT BE SURPRISED IF THE DAY SHIFT WILL BE ABLE TO REMOVE CHANCES. HIGH PRESSURE WILL SETTLE BACK OVER THE CWA FOR THE LATTER PART OF THE WEEKEND INTO EARLY NEXT WEEK. EXPECT SUNDAY NIGHT TO BE ANOTHER CHILLY NIGHT WITH SEVERAL LOCATIONS ACROSS WEST TENNESSEE AND POSSIBLY NORTHEAST MISSISSIPPI GETTING DOWN INTO THE UPPER 30S. ANOTHER COLD FRONT OR LOW PRESSURE SYSTEM MAY AFFECT THE MIDSOUTH MONDAY NIGHT INTO TUESDAY. GFS AND ECMWF HAVE DIFFERENT SOLUTIONS WITH THE ECMWF BEING DRIER. FOR NOW HAVE ADDED 20 POPS FOR TUESDAY. KRM .AVIATION... 12Z TAF CYCLE LIGHT RAIN CONTINUES TO FALL OVER PORTIONS OF THE FORECAST AREA AND WILL CONTINUE TO MOVE ACROSS THE FORECAST AREA DURING MUCH OF THE FORECAST PERIOD. CEILINGS WILL BEGIN TO IMPROVE AFTER SUNRISE BUT LIKELY REMAIN MVFR AT ALL SITES WITH THE EXCEPTION OF JBR WHERE VFR CONDITIONS SHOULD PREVAIL. WINDS WILL SHIFT FROM THE NORTH...INCREASING TO AROUND 10 KTS TODAY...DIMINISHING SLIGHTLY TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... MEM 63 55 69 47 / 100 30 20 10 MKL 62 54 66 40 / 100 30 20 10 JBR 65 49 67 42 / 90 20 10 10 TUP 69 57 67 47 / 90 50 30 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1023 AM CDT WED OCT 16 2013 .UPDATE... SEE DISCUSSION FOR MORNING UPDATE. && .DISCUSSION... WIDESPREAD CLOUD COVER ACROSS THE CWA THIS MORNING AS A COLD FRONT LIES ACROSS WASHINGTON... GRIMES... AND TRINITY COUNTIES. THERE IS A WIND SHIFT AHEAD OF THE PRECIP WHICH APPEARS TO BE A PRE FRONTAL TROUGH. BEHIND THE FRONT TEMPERATURES ARE RIGHT AROUND 60 DEGREES AND WILL PROBABLY HAVE TROUBLE GETTING MUCH WARMER AS WIDESPREAD CLOUD COVER AND COLD AIR ADVECTION TAKES OVER. GFS AND NAM OMEGA FIELDS ARE SHOWING BEST LIFT WERE CURRENT PRECIP LIES AND PUSHING OFF TOWARDS THE NORTHEAST. THE NAM IS HINTING AT SOME LIGHTER LIFT MOVING ACROSS THE AREA BELOW THE MAIN PRECIP SHIELD. WHEN LOOKING AT THE 300K SURFACE BEST ISENTROPIC LIFT APPEARS TO BE OCCURRING NOW AND WILL BEGIN TO DISAPPEAR AS WINDS VEER NORTHWESTERLY. ALL OF THIS BEING SAID NOT SURE HOW MUCH OF THE MAIN PRECIP SHIELD WILL MAKE IT TO THE COAST BEFORE DISSIPATING. IT APPEARS THE BEST LIFT WILL BE GONE BY THEN. THERE IS A CHANCE OF SOME ISOLATED SHOWERS AHEAD OF THE MAIN PRECIP BAND BUT THESE SHOULD BE LIMITED. HAVE MADE MINOR CHANGES TO POP AND TEMPERATURE GRIDS TO ACCOUNT FOR THESE TRENDS. NEW GRIDS OUT SHORTLY. 23 && .PREV DISCUSSION... /ISSUED 643 AM CDT WED OCT 16 2013/ DISCUSSION... 12Z TAF DISCUSSION IN AVIATION SECTION. AVIATION... COLD FRONT PUSHING THROUGH HOUSTON AREA THIS MORNING WITH IFR/LIFR CIGS BEHIND THE FRONT. AREA RADAR SHOW BULK OF -RA/RA OVER C TX. EXPECT THIS TO MOVE ACROSS THE NORTHERN HALF OF SE TX DURING THE DAY. THIS SHOULD KEEP CIGS LOW FOR AT LEAST THE NEXT 6-12 HRS BEFORE IMPROVING OVERNIGHT. KCLL/KUTS/KCXO...IFR/LIFR CIGS ALREADY IN PLACE SO WILL KEEP CIGS LOW THROUGH THE NEXT 6-12HRS. EXPECT -RA/RA TO SPREAD OVER THE AREA LATE MORNING THROUGH EARLY AFTERNOON. LIKE HRRR TIMING OF PRECIP BEGIN/END SO TAF REFLECTS THAT TIMING. LOOK FOR MVFR CIGS IN THE AFTERNOON AND HOLDING THROUGH THE NIGHT. LOOKS LIKE VFR CIGS AFTER 12Z THUR. KIAH/KHOU/KSGR...COLD FRONT HAS PUSHED THROUGH KIAH/KSGR BUT JUST AT THE DOOR STEP OF KHOU. GO AHEAD WITH IFR CIGS FOR ALL TERMINALS TO START THE TAF. HAD KDWH REPORT OVC003 SO TEMPO THAT FOR A COUPLE OF HOURS GIVEN THE POSSIBILITY. LIKE HRRR TIMING OF PRECIP BUT REALLY THINK BULK OF -RA/RA WILL BE NORTH OF HOUSTON TERMINALS. WILL STILL CARRY -RA STARTING 16/17Z THROUGH 22Z THIS AFTERNOON. CIGS SHOULD IMPROVE TO MVFR IN THE EARLY AFTERNOON. KLBX/KGLS...COLD FRONT APPROACHING THESE TERMINALS THIS MORNING. EXPECT CIGS TO GO DOWN TO IFR BEHIND THE FRONT LIKE OTHER TERMINALS BUT COULD SEE ONLY MVFR. IFR/MVFR CIGS WILL BE CHALLENGING TO DETERMINE DUE TO THE COAST AND HOW AIRMASS BEHIND THE FRONT MODIFIES DURING THE DAY. WILL MENTION -RA DURING EARLY AFTERNOON BUT THINK MOST OF RAINFALL WILL BE WELL NORTH OF THE COAST. SHOULD SEE CIGS IMPROVE LATE AFTERNOON THROUGH OVERNIGHT. 39 PREV DISCUSSION... /ISSUED 508 AM CDT WED OCT 16 2013/ DISCUSSION... THE SOUTHWESTERLY FLOW ALOFT PRESENT EARLY THIS MORNING WAS DUE TO AN UPPER LEVEL HIGH PRESSURE CENTERED OVER THE SOUTHERN GULF AND AN UPPER TROUGH BETWEEN THE WESTERN GREAT LAKES AND THE SOUTHERN ROCKIES. PACIFIC MOISTURE WAS CAUGHT UP IN THE FLOW BUT WAS JUST WEST AND NORTH OF THE FORECAST AREA AT 5 AM. THE MAIN ITEMS OF CONCERN INCLUDE RAIN CHANCES AND TEMPERATURES. THE COLD FRONT WAS PUSHING ACROSS THE CENTRAL AND SOUTHERN COUNTIES EARLY THIS MORNING. THE FRONT SHOULD WORK ITS WAY OFF THE MATAGORDA COAST LATER THIS MORNING AND THEN OFF THE GALVESTON COAST LATER THIS AFTERNOON. MOST OF THE RAINFALL WAS FALLING WELL BEHIND THE FRONT AND AHEAD OF THE 850 MB TROUGH. THE MODELS DO NOT PUSH THE 850 MB TROUGH THROUGH SE TX UNTIL THURSDAY MORNING. DO EXPECT THE MAIN BULK OF THE RAIN TO PUSH INTO THE NORTHWESTERN QUARTER OF THE FORECAST AREA LATER THIS MORNING. THE HIGH PRESSURE IN THE GULF SHOULD ACTUALLY HELP THE RAIN CHANCES DROP OFF OVER THE CENTRAL AND COASTAL AREAS TODAY...ALTHOUGH CHANCES FOR RAIN WILL LINGER OVER THE SOUTHEASTERN HALF OF THE FORECAST AREA TONIGHT AND EARLY THURSDAY AS THE 850 MB TROUGH PUSHES THROUGH. DO NOT EXPECT RAINFALL AMOUNTS TODAY OR TONIGHT TO EXCEED ONE QUARTER TO ONE HALF OF AN INCH ON AVERAGE. THERE IS SOME CONSENSUSFOR A BREAK IN THE RAINY PATTERN THURSDAY AFTERNOON AND EVENING BEFORE ISENTROPIC LIFT HELPS TO RETURN RAIN CHANCES LATE THURSDAY NIGHT AND FRIDAY. THE MODELS THEN PUSH THE COASTAL FRONT EAST OF THE AREA ON SATURDAY WITH SUNDAY LOOKING DRY. BOTH THE GFS AND ECMWF BRING ANOTHER FRONTAL SYSTEM ACROSS SE TX AND RETURN RAIN CHANCES EARLY NEXT WEEK. A PERIOD OF BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK. SOME LOCATIONS NEAR COLLEGE STATION MAY EVEN EXPERIENCE HIGH TEMPERATURES TODAY ALMOST 20 DEGREES BELOW NORMAL. DO EXPECT A WARMUP TO NEAR NORMAL DAYTIME TEMPERATURES TO BEGIN EARLY NEXT WEEK AHEAD OF THE NEXT COLD FRONT. 40 MARINE... COLD FRONT CURRENTLY WORKING THROUGH SE TX THIS MORNING SHOULD PUSH OFF THE COAST THIS EVENING WITH INCREASING NORTHERLY WINDS TONIGHT. MAY NEED SCEC FOR OFFSHORE WATERS BUT WILL BE BODERLINE TO ISSUE AT THIS TIME. SEAS LIKELY REMAIN AROUND 3-4FT WITH 15 KT WINDS. WINDS TURN MORE TO THE EAST FOR THE END OF THE WEEK. MEDIUM RANGE MODELS STILL SHOWING ANOTHER FRONTAL PUSH ON SATURDAY WHICH MAY BE STRONGER. LIKELY SEE SCEC CONDITIONS WITH 4-5FT SEAS OFFSHORE. NE WINDS WILL CONTINUE INTO SUNDAY WITH SEAS REMAINING AROUND 4FT IN OFFSHORE AREAS. 39 AVIATION... COLD FRONT JUST AT THE DOOR STEP OF KCXO AND KDWH. OBS BEHIND THE FRONT SHOWING IFR/LIFR CIGS SO MAY NEED TO UPDATE TAFS FOR CIGS. DO EXPECT SOME RAIN TODAY BUT THINKING IT WILL NOT BE NEARLY AS INTENSE AS PREVIOUSLY THOUGHT. GENERALLY THINK THERE WILL BE PERIODS OF LIGHT RAIN...POSSIBLY AN ISO TSRA BUT THAT LOOKS LESS LIKELY AT THIS POINT. MAIN CONCERN WILL BE HOW LONG IFR CIGS HOLD OVER SE TX BEHIND THE FRONT. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 62 53 73 55 73 / 80 20 10 10 50 HOUSTON (IAH) 74 58 74 56 75 / 50 50 20 10 40 GALVESTON (GLS) 80 65 75 67 76 / 30 50 40 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
643 AM CDT WED OCT 16 2013 .DISCUSSION... 12Z TAF DISCUSSION IN AVIATION SECTION. && .AVIATION... COLD FRONT PUSHING THROUGH HOUSTON AREA THIS MORNING WITH IFR/LIFR CIGS BEHIND THE FRONT. AREA RADAR SHOW BULK OF -RA/RA OVER C TX. EXPECT THIS TO MOVE ACROSS THE NORTHERN HALF OF SE TX DURING THE DAY. THIS SHOULD KEEP CIGS LOW FOR AT LEAST THE NEXT 6-12 HRS BEFORE IMPROVING OVERNIGHT. KCLL/KUTS/KCXO...IFR/LIFR CIGS ALREADY IN PLACE SO WILL KEEP CIGS LOW THROUGH THE NEXT 6-12HRS. EXPECT -RA/RA TO SPREAD OVER THE AREA LATE MORNING THROUGH EARLY AFTERNOON. LIKE HRRR TIMING OF PRECIP BEGIN/END SO TAF REFLECTS THAT TIMING. LOOK FOR MVFR CIGS IN THE AFTERNOON AND HOLDING THROUGH THE NIGHT. LOOKS LIKE VFR CIGS AFTER 12Z THUR. KIAH/KHOU/KSGR...COLD FRONT HAS PUSHED THROUGH KIAH/KSGR BUT JUST AT THE DOOR STEP OF KHOU. GO AHEAD WITH IFR CIGS FOR ALL TERMINALS TO START THE TAF. HAD KDWH REPORT OVC003 SO TEMPO THAT FOR A COUPLE OF HOURS GIVEN THE POSSIBILITY. LIKE HRRR TIMING OF PRECIP BUT REALLY THINK BULK OF -RA/RA WILL BE NORTH OF HOUSTON TERMINALS. WILL STILL CARRY -RA STARTING 16/17Z THROUGH 22Z THIS AFTERNOON. CIGS SHOULD IMPROVE TO MVFR IN THE EARLY AFTERNOON. KLBX/KGLS...COLD FRONT APPROACHING THESE TERMINALS THIS MORNING. EXPECT CIGS TO GO DOWN TO IFR BEHIND THE FRONT LIKE OTHER TERMINALS BUT COULD SEE ONLY MVFR. IFR/MVFR CIGS WILL BE CHALLENGING TO DETERMINE DUE TO THE COAST AND HOW AIRMASS BEHIND THE FRONT MODIFIES DURING THE DAY. WILL MENTION -RA DURING EARLY AFTERNOON BUT THINK MOST OF RAINFALL WILL BE WELL NORTH OF THE COAST. SHOULD SEE CIGS IMPROVE LATE AFTERNOON THROUGH OVERNIGHT. 39 && .PREV DISCUSSION... /ISSUED 508 AM CDT WED OCT 16 2013/ DISCUSSION... THE SOUTHWESTERLY FLOW ALOFT PRESENT EARLY THIS MORNING WAS DUE TO AN UPPER LEVEL HIGH PRESSURE CENTERED OVER THE SOUTHERN GULF AND AN UPPER TROUGH BETWEEN THE WESTERN GREAT LAKES AND THE SOUTHERN ROCKIES. PACIFIC MOISTURE WAS CAUGHT UP IN THE FLOW BUT WAS JUST WEST AND NORTH OF THE FORECAST AREA AT 5 AM. THE MAIN ITEMS OF CONCERN INCLUDE RAIN CHANCES AND TEMPERATURES. THE COLD FRONT WAS PUSHING ACROSS THE CENTRAL AND SOUTHERN COUNTIES EARLY THIS MORNING. THE FRONT SHOULD WORK ITS WAY OFF THE MATAGORDA COAST LATER THIS MORNING AND THEN OFF THE GALVESTON COAST LATER THIS AFTERNOON. MOST OF THE RAINFALL WAS FALLING WELL BEHIND THE FRONT AND AHEAD OF THE 850 MB TROUGH. THE MODELS DO NOT PUSH THE 850 MB TROUGH THROUGH SE TX UNTIL THURSDAY MORNING. DO EXPECT THE MAIN BULK OF THE RAIN TO PUSH INTO THE NORTHWESTERN QUARTER OF THE FORECAST AREA LATER THIS MORNING. THE HIGH PRESSURE IN THE GULF SHOULD ACTUALLY HELP THE RAIN CHANCES DROP OFF OVER THE CENTRAL AND COASTAL AREAS TODAY...ALTHOUGH CHANCES FOR RAIN WILL LINGER OVER THE SOUTHEASTERN HALF OF THE FORECAST AREA TONIGHT AND EARLY THURSDAY AS THE 850 MB TROUGH PUSHES THROUGH. DO NOT EXPECT RAINFALL AMOUNTS TODAY OR TONIGHT TO EXCEED ONE QUARTER TO ONE HALF OF AN INCH ON AVERAGE. THERE IS SOME CONSENSUSFOR A BREAK IN THE RAINY PATTERN THURSDAY AFTERNOON AND EVENING BEFORE ISENTROPIC LIFT HELPS TO RETURN RAIN CHANCES LATE THURSDAY NIGHT AND FRIDAY. THE MODELS THEN PUSH THE COASTAL FRONT EAST OF THE AREA ON SATURDAY WITH SUNDAY LOOKING DRY. BOTH THE GFS AND ECMWF BRING ANOTHER FRONTAL SYSTEM ACROSS SE TX AND RETURN RAIN CHANCES EARLY NEXT WEEK. A PERIOD OF BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK. SOME LOCATIONS NEAR COLLEGE STATION MAY EVEN EXPERIENCE HIGH TEMPERATURES TODAY ALMOST 20 DEGREES BELOW NORMAL. DO EXPECT A WARMUP TO NEAR NORMAL DAYTIME TEMPERATURES TO BEGIN EARLY NEXT WEEK AHEAD OF THE NEXT COLD FRONT. 40 MARINE... COLD FRONT CURRENTLY WORKING THROUGH SE TX THIS MORNING SHOULD PUSH OFF THE COAST THIS EVENING WITH INCREASING NORTHERLY WINDS TONIGHT. MAY NEED SCEC FOR OFFSHORE WATERS BUT WILL BE BODERLINE TO ISSUE AT THIS TIME. SEAS LIKELY REMAIN AROUND 3-4FT WITH 15 KT WINDS. WINDS TURN MORE TO THE EAST FOR THE END OF THE WEEK. MEDIUM RANGE MODELS STILL SHOWING ANOTHER FRONTAL PUSH ON SATURDAY WHICH MAY BE STRONGER. LIKELY SEE SCEC CONDITIONS WITH 4-5FT SEAS OFFSHORE. NE WINDS WILL CONTINUE INTO SUNDAY WITH SEAS REMAINING AROUND 4FT IN OFFSHORE AREAS. 39 AVIATION... COLD FRONT JUST AT THE DOOR STEP OF KCXO AND KDWH. OBS BEHIND THE FRONT SHOWING IFR/LIFR CIGS SO MAY NEED TO UPDATE TAFS FOR CIGS. DO EXPECT SOME RAIN TODAY BUT THINKING IT WILL NOT BE NEARLY AS INTENSE AS PREVIOUSLY THOUGHT. GENERALLY THINK THERE WILL BE PERIODS OF LIGHT RAIN...POSSIBLY AN ISO TSRA BUT THAT LOOKS LESS LIKELY AT THIS POINT. MAIN CONCERN WILL BE HOW LONG IFR CIGS HOLD OVER SE TX BEHIND THE FRONT. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 62 53 73 55 73 / 60 20 10 10 50 HOUSTON (IAH) 74 58 74 56 75 / 60 50 20 10 40 GALVESTON (GLS) 81 65 75 67 76 / 30 50 40 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
340 PM MDT WED OCT 16 2013 .SHORT TERM...MID LEVEL DISTURBANCE MOVING ACROSS SOUTHEAST COLORADO WITH SUBSIDENCE SPREADING ACROSS CFWA. STILL SOME CLOUDS ALONG THE CONTINENTAL DIVIDE AND WEAK OROGRAPHIC LIFT GENERATING A FEW LIGHT SNOW SHOWERS. SHOWERS SHOULD BE ENDING SHORTLY AS AIRMASS CONTINUES TO DRY OUT. WEAK SHORTWAVE RIDGE TO MOVE ACROSS AREA OVERNIGHT WITH FLOW ALOFT BECOMING NORTHWEST. MAINLY CLEAR SKIES TO PREVAIL. OVERNIGHT TEMPERATURES TO BE FAIRLY CHILLY DUE TO LIGHT WINDS AND CLEAR SKIES. ON THURSDAY...NORTHWEST FLOW ALOFT TO CONTINUE AS AN UPPER LEVEL DISTURBANCE MOVES INTO THE NORTHERN GREAT BASIN. MOISTURE WILL BE ON THE INCREASE BY THE AFTERNOON WITH INCREASING OROGRAPHICS. THOUGH MOST OF THE MID LEVEL QG ASCENT STAYS TO THE NORTH AND WEST...THERE IS ENOUGH LIFT TO INCREASE POPS A BIT FURTHER ACROSS THE MOUNTAINS AND FOOTHILLS. SNOW ACCUMULATIONS OF UP TO 2 INCHES WILL BE POSSIBLE BY THE EVENING. AS FOR FOOTHILLS...APPEARS TEMPERATURES SHOULD BE WARM ENOUGH FOR MAINLY RAIN...WITH A MIX OF RAIN AND SNOW POSSIBLE HIGHER AREAS NEAR THE WYOMING BORDER. ACROSS PLAINS...COLD FRONT TO MOVE ACROSS THE AREA DURING DURING THE AFTERNOON...WITH MODELS SHOWING THE MAIN COLD AIR ADVECTION DURING THE EVENING. CROSS SECTIONS KEEP UPSLOPE FAIRLY SHALLOW THROUGH THE AFTERNOON. BUT INCREASING MID LEVEL ASCENT ENOUGH TO KEEP A SLIGHT CHANCE OF SHOWERS GOING. DID INCREASE THE POPS ACROSS ZONE 38 WHERE THE GREATER LIFT WILL BE. THERE COULD BE A RAIN/SNOW MIX NEAR THE WYOMING BORDER ALONG THE HIGHER AREAS OF THE CHEYENNE RIDGE. OVERALL CURRENT TEMPERATURE GRIDS SEEM REASONABLE...IN LINE WITH LATEST GUIDANCE. .LONG TERM...THURSDAY NIGHT WILL BE VERY ACTIVE ACROSS THE FORECAST AREA AS A SHORT WAVE RIDING DOWN THE BACK SIDE OF A STRONG RIDGE OVER THE PACIFIC NORTHWEST MOVES OVER THE STATE. THE DISTURBANCE WILL CONTAIN QUITE A BIT OF FRONTOGENESIS AT MID- LEVELS DUE TO STRONG CYCLONIC CURVATURE IN THE WIND FIELD AND A STRONG NORTHERLY JET ALOFT APPROACHING THE AREA FROM THE NORTH. MOUNTAIN AREAS SHOULD PICK UP A FAIR AMOUNT OF SNOWFALL WHICH MAY ALSO SPREAD EASTWARD OVER THE NORTHERN FRONT RANGE FOOTHILLS. WILL ISSUE A WINTER WEATHER ADVISORY FOR ZONES 33...34 AND 35 STARTING A 9 PM TOMORROW EVENING THROUGH MIDDAY FRIDAY. FOUR TO 8 INCH ACCUMULATIONS WILL BE POSSIBLE IN THOSE AREAS. AT LOW LEVELS... UPSLOPE FLOW WILL BE CONTINUING ON THE PLAINS WHICH WILL ALSO GIVE THE MOISTENING AIRMASS JUST A LITTLE BIT MORE LIFT. ON THE PLAINS...TEMPERATURES MAY STILL BE WARM ENOUGH IN THE EVENING FOR THE PRECIPITATION TO BEGIN AS RAIN. THROUGH THE NIGHT...EXPECT TEMPERATURES TO DROP TO THE UPPER 20S AND LOWER 30S WITH PRECIPITATION CHANGING TO SNOW. LIGHT ACCUMULATIONS WILL BE POSSIBLE ACROSS THE PLAINS...BUT MOSTLY LESS THAN 2 INCHES EXCEPT ON THE PALMER DIVIDE. ALL OF THE MODELS ARE IN CLOSE AGREEMENT IN MOVING THE UPPER DISTURBANCE OUT OF THE STATE QUICKLY ON FRIDAY. MOST PRECIPITATION WILL BE OUT OF THE STATE BY NOON...EXCEPT FOR SOME LINGERING SHOWERS OVER THE MOUNTAINS. BEYOND THAT...THE MODELS ALL SHOW MODERATE NORTHWEST FLOW ACROSS COLORADO AS THE WEST COAST RIDGE DE-AMPLIFIES AND EXTENDS TO THE DESERT SOUTHWEST. THIS WILL BRING AN EXTENDED PERIOD OF DRY WEATHER TO THE STATE WITH TEMPERATURES CLIMBING TO AROUND SEASONAL NORMALS. && .AVIATION...NORTHEAST WINDS CURRENTLY AT AREA AIRPORTS. BOTH NAM AND HRRR SHOW WINDS SHIFTING TO THE NORTHWEST BY 00Z THEN SOUTHWEST DURING THE EVENING SPEEDS TO REMAIN LESS THAT 10 KTS. WINDS TO BECOME NORTHWEST AFTER 15Z THURSDAY BEHIND A PASSING WEAK COLD FRONT...THEN NORTHEAST BY AROUND 18Z. SPEEDS SHOULD REMAIN LESS THAN 10 KTS. MID AND HIGH LEVEL MOISTURE TO INCREASE DURING THE DAY...CEILINGS SHOULD REMAIN ABOVE 10000 FEET. A FEW RAIN SHOWERS POSSIBLE AFTER 21Z...MAINLY NORTH AND WEST OF THE AREA. VFR TO PREVAIL. && .HYDROLOGY...MOISTURE TO INCREASE DURING THE DAY THURSDAY AHEAD OF THE NEXT WEATHER SYSTEM...WITH SHOWERS DEVELOPING BY THE AFTERNOON. TEMPERATURES WILL BE COLD ENOUGH FOR SNOW OVER THE MOUNTAINS DURING THE AFTERNOON WITH LIGHT ACCUMULATIONS BY THE EVENING. ALONG THE FOOTHILLS...RAINFALL AMOUNTS WILL BE LIGHT...LESS THAN A TENTH OF AN INCH. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 9 PM THURSDAY TO NOON MDT FRIDAY FOR COZ033>035. && $$ SHORT TERM...D-L LONG TERM....DANKERS AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1030 AM MDT WED OCT 16 2013 .UPDATE... && .SHORT TERM...TEMPERATURES HAVE WARMED TO THE LOWER 30S ACROSS THE NORTHEAST PLAINS...THOUGH A FEW LOCATIONS ALONG THE RIVER BOTTOMS STILL AROUND 30. FREEZE WARNING HAS BEEN ALLOWED TO EXPIRE. OTHERWISE...WEAK MID LEVEL DISTURBANCE MOVING ACROSS SOUTHERN COLORADO WITH SOME CLOUDS OVER MOUNTAINS...SOUTHERN FOOTHILLS AND SOUTH PARK. MAIN LIFT ACROSS SOUTHERN COLORADO...VERY LIMITED OVER SOUTHERN SECTIONS OF CFWA. LATEST RUC AND NAM SHOWING A DRIER SUBSIDENT AIRMASS OVER THE AREA BY 18Z AS THE DISTURBANCE MOVES OUT OF COLORADO. WILL LIMIT ANY PRECIPITATION CHANCES FOR THE THE CENTRAL MOUNTAINS AND SOUTH PARK DURING THE MORNING HOURS. WILL ALSO DECREASE THE CLOUDS A BIT...BASED ON CURRENT SATELLITE. REST OF FORECASTS SEEM ON TRACK...WITH WARMER TEMPERATURES EXPECTED TODAY. .AVIATION...CURRENT TAF TRENDS LOOK ON TRACK WITH VFR CONDITIONS PREVAILING. WINDS SHOWING SIGNS OF BECOMING A BIT MORE NORTHWEST... WITH SPEEDS LESS THAN 8 KTS. SHOULD SEE WINDS SHIFTING TO THE NORTHEAST BY 20Z...WITH SPEEDS AROUND 8 KTS. LATEST RAP AND TO A CERTAIN EXTEND THE HRRR INDICATING WINDS BECOMING SOUTHEAST BY 02Z. WITH FLOW ALOFT BECOMING MORE NORTHWEST AND A BIT OF MIXING...WOULD EXPECT WINDS TO HAVE MORE OF A NORTHWEST DIRECTION THROUGH 02Z BEFORE SHIFING TO THE SOUTHWEST. && .PREV DISCUSSION... /ISSUED 253 AM MDT WED OCT 16 2013/ SHORT TERM...SHARPLY TILTED UPPER TROUGH AND LOW CENTER CONTINUE THEIR SLOW EASTWARD PROGRESS ACROSS COLORADO AT THIS TIME. ON SATELLITE IMAGERY...THE MID-LEVEL CIRCULATION APPEARED TO BE CENTERED IMMEDIATELY NORTHEAST OF THE FOUR CORNERS. INCREASING CLOUD ENHANCEMENT SHOWING UP ON IR SAT IMAGERY OVER SOUTH CENTRAL AND SOUTHEAST COLORADO ASSOCIATED WITH WARM ADVECTION/ISENTROPIC LIFT OUT AHEAD OF THE UPPER LOW. AREA OF ENHANCEMENT EXTENDS AS FAR NORTH AS THE PALMER DIVIDE. IN THE PAST HOUR NWS DEN AND PUB RADARS DETECTED A MODEST INCREASE IN PRECIP ECHO COVERAGE ACROSS SOUTHEAST COLORADO. NOW SEE A FEW ECHOS POPPING OVER THE FOOTHILLS IN DOUGLAS COUNTY AND THE SOUTHWEST TIP OF LINCOLN COUNTY. THE STRONGER RADAR RETURNS REMAIN WELL SOUTH OF THE AREA. OVER THE NEXT SEVERAL HOURS NAM...GFS...WRF AND EUROPEAN MODELS ALL SHOW THE UPPER LOW WITH ITS LIFT AND PRECIPITATION FIELDS TRACKING EASTWARD ALONG THE SOUTHEAST COLORADO/NORTHEAST NEW MEXICO BORDER. SOUTHERN PORTIONS OF OUR FORECAST AREA MAY CATCH SOME OF THE NORTHERN EDGE OF THIS SYSTEM IN THE FORM OF A FEW SNOW SHOWERS GENERALLY OF LIGHT INTENSITY. SOUTH PARK AND FOOTHILL AREAS WEST/SOUTHWEST OF DENVER MAY ALSO SEE AN UPTICK IN PRECIP FORMATION IN THE NEXT FEW HOURS. HOWEVER ANY QPF/SNOW ACCUMULATION SHOULD BE MINIMAL IF ANY. HOWEVER ALL BUT THE FAR NORTHEAST CORNER OF THE CWFA WILL LIKELY REMAIN UNDER MOSTLY TO OVERCAST SKIES THROUGH THE EARLY MORNING HOURS...AT LEAST UNTIL THE UPPER LOW MOVES EAST OF THE AREA AND THE 850-600 MB TURNS NORTHWESTERLY. OVERALL..THE FREEZE WARNING OVERNIGHT VERIFIED. AT THE PRESENT TIME...TEMPERATURES ON THE PLAINS IN THE MID TO UPPER 20S ALL EXCEPT IN BOULDER COUNTY WHERE THE LOW CLOUD COVER HAS HELD TEMPERATURES TO THE LOW/MID 30S. WITH ANY CLEARING DURING THE NEXT FEW HOURS...WARNING SHOULD VERIFY THERE...TOO. FOR THE REMAINDER OF TODAY...THE UPPER TROUGH MOVES OUT ALLOWING DRIER AIR TO FILTER DOWN FROM WYOMING RESULTING IN GRADUAL CLEARING FROM NORTH TO SOUTH. RETURN OF SUNSHINE BY AFTERNOON SHOULD RETURN TEMPERATURES TO THE 50S ON THE PLAINS. CLEARING WON/T BE AS QUICK IN THE HIGH COUNTRY SO ONLY SLIGHTLY WARMER UP THERE TODAY. HIGHER ELEVATIONS SHOULD ALSO SEE THE LAST OF THE FEW REMAINING LIGHT SNOW SHOWERS BY LATE MORNING OR EARLY AFTERNOON. FOR THE MOST PART WINDS WILL BE LIGHT TODAY EXCEPT IN THE FAR NORTHEAST WHERE NWLY WINDS OF 10-20KTS EXPECTED TO DEVELOP THIS AFTERNOON WITH INCREASING NORTHWESTERLY FLOW ALOFT ON THE BACK SIDE OF THE TROUGH. OVERNIGHT...A WEAK SHORTWAVE RIDGE EMBEDDED IN NORTHWESTERLY FLOW ALOFT WILL PASS OVERHEAD. CLEAR SKIES...CHILLY TEMPERATURES AND LIGHT WINDS WILL BE THE RULE. ALTHOUGH THE FAR NORTHEAST CORNER MAY CONTINUE TO SEE NORTHWEST WINDS OF 10-15 KTS FOR MUCH OF THE NIGHT IN RESPONSE TO STRENGTHENING NORTHWESTERLY FLOW ALOFT. LONG TERM...FOR MUCH OF THE LONG TERM FORECAST COLORADO WILL BE UNDER A MODERATE NORTHWEST FLOW PATTERN AS HIGH PRESSURE RIDGING ALOFT REMAINS OFF THE WEST COAST. WITHIN THE FLOW...AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO THURSDAY NIGHT AND FRIDAY MORNING WITH THE NEXT SHOT OF PRECIP FOR THE AREA. OVER THE PAST FEW RUNS THE MODELS HAVE BECOME VERY CONSISTENT WITH THIS WAVE AND TIMING. HENCE...WITH INCREASING CONFIDENCE WILL CONTINUE THE UPWARD TREND IN CHANCES OF RAIN AND SNOW. AN ASSOCIATED COLD FRONT WILL MOVE INTO NORTHEAST COLORADO THURSDAY AFTERNOON WITH SHALLOW UPSLOPE FLOW DEVELOPING. INITIALLY THE AIRMASS WILL BE DRY BUT EXPECT INCREASING MOISTURE DURING LATE THURSDAY AFTERNOON AND EVENING. APPEARS THERE WILL BE ENOUGH COOLING FOR MOST LOCALES TO SEE SNOW LATE THURSDAY NIGHT AND INTO FRIDAY MORNING AS AIRMASS SATURATES. OVERALL QPF FROM MODELS IS RANGING FROM .10 TO UP TO 50" OF AN INCH SO CONCEIVABLE THAT THE NORTHEAST PLAINS AND MOUNTAINS MAY SEE A COUPLE OF INCHES OF SNOW FROM THIS SYSTEM. THERE IS SOME MODEST QG FORCING ALOFT AS THIS SYSTEM PASSES ACROSS COLORADO. THE SNOW WILL END FROM NORTH TO SOUTH ON FRIDAY MORNING WITH A RETURN TO DRY CONDITIONS FROM LATE FRIDAY THROUGH THE WEEKEND. THERE IS ANOTHER WEAK WAVE THAT BRUSHES NORTHEAST COLORADO SUNDAY NIGHT AND MONDAY BUT FOR NOW MOISTURE LOOKS QUITE LIMITED WITH THIS SYSTEM. WITH THE NORTHWEST FLOW PATTERN A STRONGER JET STREAK WILL APPROACH NORTHEAST COLORADO LATE MONDAY AND TUESDAY WITH SOME MOISTURE. BEING THAT FAR OUT WILL KEEP THINGS DRY FOR NOW. AVIATION...LOW CLOUD CEILINGS IN THE 3000-5000 FT AGL RANGE IN THE DENVER AREA AS OF 09Z/WED. LOWER CEILINGS FOUND IN THE MTNS AND FOOTHILLS. LOW CLOUDS OVER AND NEAR THE FOOTHILLS WEST AND SOUTHWEST OF DENVER PRODUCING SNOW FLURRIES AT THIS TIME. DO NOT EXPECT TO SEE MORE THAN A FEW FLURRIES AT DENVER AREA AIRPORTS NOW THROUGH 15Z THIS MORNING. OTHERWISE CEILINGS IN THE DENVER AREA SHOULD BEGIN LIFTING NOT LONG AFTER SUNRISE (13Z-14Z)...WITH VFR CEILINGS BY MID-MORNING...AND PARTLY CLOUDY SKIES BY MIDDAY. THE OUTLOOK IS FOR VARIABLE WINDS GENERALLY UNDER 10 KTS TODAY. TONIGHT EXPECT TYPICAL DRAINAGE WINDS UNDER 8 KTS UNDERNEATH A CLEAR TO MOSTLY CLEAR SKY. HYDROLOGY...NO CONCERNS AT THIS TIME. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....ENTREKIN AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
351 PM EDT WED OCT 16 2013 ...SHALLOW COASTAL FLOODING LIKELY AROUND HIGH TIDE THIS EVENING... ...COASTAL FLOOD ADVISORY IN EFFECT FROM 5 PM UNTIL 10 PM EDT... .SYNOPSIS... WEAK HIGH PRESSURE WILL PREVAIL OVER THE REGION TONIGHT. A COLD FRONT WILL MOVE INTO THE AREA EARLY FRIDAY...THEN STALL ALONG THE SOUTHEAST COAST THROUGH SATURDAY. THE FRONT WILL PUSH OFFSHORE ON SUNDAY...AS HIGH PRESSURE BUILDS FROM THE NORTHWEST AND PREVAILS INTO EARLY NEXT WEEK. A WAVE OF LOW PRESSURE COULD APPROACH FROM THE SOUTHWEST DURING THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... WEAK HIGH PRESSURE WILL HOLD FIRM ACROSS THE REGION TONIGHT. THE SHALLOW CUMULUS FIELD THAT HAS DEVELOPED THIS AFTERNOON WILL QUICKLY DISSIPATE THIS EVENING WITH THE LOSS OF INSOLATION. HOWEVER...A THICK MID/HIGH-LEVEL CLOUD DECK ASSOCIATED WITH AN APPROACHING COLD FRONT WILL BEGIN TO AFFECT THE FAR WESTERN ZONES EARLY THIS EVENING...SPREADING STEADILY EAST TO THE COAST. SHOULD SEE MOSTLY CLOUDY IF NOT CLOUDY SKIES DOMINATE FROM LATE EVENING ON. THE INCREASED CLOUD COVER WILL PROMOTE WARMER OVERNIGHT LOWS...RANGING FROM THE LOWER 60S INLAND TO THE MID/UPPER 60S AT THE BEACHES. SREF VISIBILITY PLUMES AND RAP BUFR SOUNDINGS SUGGEST SOME SHALLOW GROUND FOG COULD AFFECT AREAS ROUGHLY ALONG AND EAST OF I-95 EARLY THURSDAY...BUT DO NOT ANTICIPATE IT WILL BECOME TOO MUCH OF AN ISSUE GIVEN THE THICK MID/HIGH-LEVEL CLOUDS THAT WILL BE IN PLACE. WILL CONTINUE TO HIGHLIGHT PATCHY FOG IN THE TEXT AND GRIDDED FORECASTS TO ACCOUNT FOR SOME SMALL REDUCTIONS IN VISIBILITIES EARLY THURSDAY. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... THURSDAY...THE AXIS OF RIDGING AT THE SURFACE AND ALOFT WILL HAVE SHIFTED OFFSHORE BY THURSDAY MORNING...WHILE AN UPPER SHORTWAVE SWEEPS NORTHEAST INTO THE GREAT LAKES DURING THE DAYTIME HOURS. THIS TRANSITION WILL ALLOW A COLD FRONT TO SHIFT TOWARD THE APPALACHIAN REGION...AND A PRE-FRONTAL TROUGH TO MOVE INTO THE WESTERN CAROLINAS...BY LATE AFTERNOON/EARLY EVENING. THE SURFACE TROUGH WILL THEN STEADILY DESCEND INTO THE FORECAST AREA OVERNIGHT...AS THE PROGRESS OF THE MAIN FRONT SLOWS UPSTREAM DUE TO DAMPENING SHORTWAVE ENERGY DEPARTING WELL TO THE NORTH. NUMERICAL MODEL SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT THAT ANY PRECIPITATION WILL REMAIN JUST TO THE WEST OF THE FORECAST AREA THROUGH AT LEAST THE DAYTIME HOURS. CONVERGENCE ASSOCIATED WITH THE APPROACHING PRE-FRONTAL TROUGH THEN SUPPORTS A SLIGHT CHANCE FOR SHOWERS ALONG THE FAR INLAND ZONES AFTER SUNSET AND OVER THE WATERS AFTER MIDNIGHT. TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE SEASONAL NORMALS AS A RESULT OF WARM WEST/SOUTHWEST FLOW AND COMPRESSIONAL HEATING AHEAD OF THE COLD FRONT. EXPECT HIGH TEMPERATURES TO RANGE IN THE LOW TO MID 80S...WITH MILD LOWS IN THE MID TO UPPER 60S. FRIDAY...AS THE APPROACHING COLD FRONT BECOMES PARALLEL TO THE FLOW ALOFT...AT THE SAME TIME THAT WEAK WAVES OF LOW PRESSURE DEVELOP ALONG THE SURFACE TROUGH...THE FRONT WILL STALL OVER THE AREA AT LEAST THROUGH FRIDAY EVENING. ALTHOUGH UPPER LEVEL SUPPORT WILL STILL REMAIN UNIMPRESSIVE...THERE COULD BE ENOUGH CONVERGENCE AND LIFT ALONG THE FRONTAL ZONES AND WITHIN A POSSIBLE SEABREEZE BOUNDARY TO SUPPORT RAIN CHANCES IN THE 20 PERCENT RANGE DURING THE DAYTIME HOURS. THE 12Z GFS SOLUTION SUGGESTS WEAK SHORTWAVE ENERGY COULD SHIFT INTO THE AREA WITHIN THE BROAD UPPER TROUGH...INCREASING RAIN CHANCES TO AROUND 30 PERCENT ALONG THE COAST AND OVER THE MARINE ZONES FRIDAY NIGHT. TEMPERATURES WILL BE SOMEWHAT DEPENDENT ON THE EXACT LOCATION OF THE STALLED FRONT...YET LATEST THINKING IS THAT BOTH HIGHS AND LOWS WILL BE AT LEAST A FEW DEGREES COOLER...PEAKING IN THE UPPER 70S TO LOWER 80S AND FALLING MAINLY INTO THE LOW TO MID 60S OVERNIGHT. SATURDAY...ADDITIONAL WEAK SHORTWAVE ENERGY WILL STREAM NORTHEAST WITHIN THE BROAD CYCLONIC FLOW ALOFT...AND WHILE THE FRONT BEGINS TO SHIFT TOWARD THE NEARSHORE WATERS AS THE DAY PROGRESSES...EXPECT SUFFICIENT MOISTURE AND CONVERGENCE FOR SCATTERED SHOWERS TO DEVELOP. THICK CLOUD COVER AND THE GRADUAL PROGRESSION OF THE FRONT THROUGH THE REGION WILL KEEP HIGH TEMPERATURES AROUND SEASONAL NORMALS IN THE UPPER 70S FOR SATURDAY AFTERNOON. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... IT LOOKS LIKE THE COLD FRONT WILL BE FORCED EAST AND SE INTO THE ATLANTIC FOR EARLY NEXT WEEK AS HIGH PRESSURE BUILDS EAST OUT OF THE CENTRAL AND EASTERN PARTS OF THE COUNTRY. BUT THE BAROCLINIC ZONE WILL BEGIN TO WORK ITS WAY BACK NORTH BY THE MIDDLE OF THE WEEK AS A SOUTHERN STREAM SHORT WAVE AND ITS CO-LOCATED SURFACE WAVE LIFTS INTO THE SE PART OF THE COUNTRY. BUT WHEN THIS OCCURS AND EXACTLY WHERE THE TRACK OF THE SURFACE LOW OCCURS REMAINS TO BE SEEN THIS FAR IN ADVANCE. RAIN CHANCES WILL DIMINISH LATER SUNDAY INTO MONDAY...BUT COULD START TO CLIMB AGAIN IN ADVANCE OF THE NEXT SYSTEM TUESDAY AND/OR WEDNESDAY. ADJUSTMENTS WILL LIKELY BE REQUIRED IN SUBSEQUENT FORECASTS. TEMPS WILL BE A BIT COOLER INTO EARLY IN THE WEEK...BUT COULD MODERATE AGAIN BY MID WEEK. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. MVFR CIGS AT KCHS WILL LIKELY HOLD ON THROUGH ABOUT 20-21Z BEFORE BREAKING AS THEY ERODE FROM THE WEST. LIGHT/SHALLOW GROUND FOG IS POSSIBLE AT EITHER TERMINAL...BUT ANY SIGNIFICANT IMPACTS SEEM LOW AT THIS POINT. EXTENDED AVIATION OUTLOOK..MVFR CONDITIONS ARE POSSIBLE AT TIMES INTO THE WEEKEND AS A FRONT STALLS OVER THE AREA. && .MARINE... TONIGHT...EAST/NORTHEAST WINDS WILL GO VARIABLE LESS THAN 5 KT ALL LEGS TONIGHT AS WEAK HIGH PRESSURE HOLD FIRM. SEAS WILL RANGE FROM 1-2 FT NEARSHORE WATERS...2-3 FT OFFSHORE WATERS AND BE COMPRISED MAINLY OF EASTERLY SWELL WITH PERIODS OF 10-11 SECONDS. THURSDAY THROUGH MONDAY...HIGH PRESSURE WILL DIMINISH AHEAD OF AN APPROACHING COLD FRONT THURSDAY AND FRIDAY. THE FRONT EVENTUALLY STALLS NEAR THE AREA THROUGH SATURDAY...BEFORE SLIDING EAST/SOUTHEAST OF THE MARINE AREA SUNDAY INTO MONDAY. CONTINENTAL HIGH PRESSURE THEN BUILDS OVER THE SOUTHEAST STATES AND EVENTUALLY INTO THE WESTERN ATLANTIC. WINDS THROUGH THE FORECAST PERIOD WILL BE CAPPED AT 15 KT OR LESS...WITH SEAS NO HIGHER THAN 2 OR 3 FT. THE BEST CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE FRIDAY INTO SUNDAY. && .TIDES/COASTAL FLOODING... ISSUED ANOTHER COASTAL FLOOD ADVISORY FOR ALL COASTAL ZONES... INCLUDING TIDAL BERKELEY...VALID 5-10 PM. TIDE IN THE CHARLESTON HARBOR IS EXPECTED TO PEAK 7.2-7.5 FT MLLW AND 9.1-9.4 FT MLLW AT FORT PULASKI. ASTRONOMICAL HIGH TIDES COURTESY OF THE FULL MOON THAT OCCURS FRIDAY EVENING WILL MOST PROBABLY GENERATE ADDITIONAL SHALLOW COASTAL FLOODING WITH MOST IF NOT ALL HIGH TIDES INTO THE WEEKEND. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR GAZ117- 119-139-141. SC...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR SCZ048>052. MARINE...NONE. && $$ ST/WMS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
142 PM CDT WED OCT 16 2013 .DISCUSSION... 306 AM CDT COOL AND PERIODICALLY DAMP WEATHER WILL DESCRIBE THE FORECAST PERIOD AS AN AMPLIFIED AND ACTIVE PATTERN SETS UP. WATER VAPOR SATELLITE IMAGERY SHOWS A LONGWAVE TROUGH THAT EXTENDS FROM JAMES BAY BACK ACROSS THE CENTRAL PLAINS TO THE FOUR CORNERS. A LARGE NORTH-SOUTH RIDGE IS IN PLACE OFF THE WEST COAST WHILE A MORE PROGRESSIVE FLOW IS FOUND OVER CENTRAL CANADA WHERE ANOTHER TROUGH AXIS IS TRANSLATING SOUTHEASTWARD. AT THE SURFACE...A LOW IS MOVING NORTHEAST ACROSS FAR NORTHERN LAKE MICHIGAN WHICH WAS RESPONSIBLE FOR PUSHING A COLD FRONT ACROSS THE AREA LAST EVENING. A RIBBON OF HIGH PRESSURE STRETCHES FROM THE PACIFIC NORTHWEST TO THE CENTRAL HIGH PLAINS. TODAY...MANY CONCERNS THIS PERIOD RANGING FROM CLOUDS AND STRATUS TO DRIZZLE. THE UPPER TROUGH EXTENDING FROM JAMES BAY SOUTHWEST HAS A CLOSED CIRCULATION EMBEDDED WITHIN IT OVER CENTRAL WISCONSIN. THIS CLOSED CIRCULATION IS EXPECTED TO OPEN UP/WEAKEN WITH THE MAIN LONGWAVE TROUGH PIVOTING ACROSS THE AREA TODAY. IR SATELLITE SHOWS A VERY LARGE AREA OF STRATUS SPREADING EASTWARD ACROSS THE LOCAL AREA. WITH THE UPPER LOW WEAKENING AS IT ARRIVES...UPWARD MOTION WILL BE DIMINISHING THROUGH THE MORNING AND HAVE SEEN THIS ALREADY OCCURRING TO THE NORTH WHERE SHOWER COVERAGE/INTENSITY HAS BEEN WANING. WITH THE EXTENSIVE STRATUS IN PLACE SURFACE WARMING WILL BE LIMITED LEAVING LOW AND MID LEVEL LAPSE RATES MEAGER. WITH THIS IN MIND EXPECT THAT THE FOCUS FOR SHOWERS WILL REMAIN NORTH OF THE AREA LEADING TO LOWER/MINIMAL POPS ACROSS NORTHERN SECTIONS OF THE LOCAL AREA. WILL GO AHEAD AND ADD DRIZZLE ACROSS NORTHERN AREAS THROUGH THE MORNING HOWEVER WITH A DECENT DEPTH OF MOISTURE AND SOME WEAK ASCENT. UPSTREAM OBS OVER THE PAST SEVERAL HOURS HAVE ALSO SHOWN A FAIR AMOUNT OF DRIZZLE. AS ALLUDED TO...THE STRATUS WILL MAKE TEMPS A CHALLENGE. STRATUS DOES LOOK TO HOLD ON THROUGH THE AFTERNOON AND WILL COMBINE WITH LOW LEVEL COLD ADVECTION TO REALLY LIMIT WARMING. UNLESS SOME BREAKS CAN DEVELOP LATE IN THE DAY ALLOWING SOME MINIMAL SUNSHINE...DO NOT EXPECT MORE THAN ABOUT A 3-5 DEGREE DIURNAL INCREASE IN TEMPS FROM MORNING LOW...QUITE A BIT COOLER THAN MOST GUIDANCE. WILL THEREFORE KEEP HIGHS IN THE LOWER 50S IN NORTHERN AREAS TO THE MID EVEN UPPER 50S FAR SOUTH...WITH A BETTER CHANCE FOR SOME SUNSHINE OVER THE EXTREME SOUTHERN PORTIONS OF THE AREA. TONIGHT THROUGH THURSDAY...ATTENTION TURNS TO THE BASE OF THE LONGWAVE UPPER TROUGH OVER THE FOUR CORNERS WHERE ANOTHER CLOSED CIRCULATION IS TAKING SHAPE. THIS LOW WILL EJECT NORTHEASTWARD AND ACROSS THE AREA THURSDAY MORNING. THIS WILL BRING ANOTHER ROUND OF SHOWERS TO MUCH OF THE AREA...ESPECIALLY THE SOUTHEAST TWO-THIRDS... STARTING LATE TONIGHT AND CONTINUING THURSDAY MORNING. TEMPS TONIGHT WILL BE DEPENDENT ON CLOUD COVER. THE LOW CLOUDS LOOK TO HANG ON THROUGH THE EVENING IF NOT THROUGH THE NIGHT. MID CLOUDS WILL BE INCREASING AHEAD OF THE APPROACHING TROUGH OVERNIGHT. WITH SOME QUESTION ABOUT HOW LONG THE LOW CLOUDS WILL HANG ON AND IF THERE WILL BE A BREAK IN CLOUD COVER BEFORE THE HIGHER CLOUDS ARRIVE WILL ONLY RAISE OVERNIGHT LOWS A FEW DEGREES IN MOST AREAS FOR NOW...WITH POTENTIAL FOR ONLY A RELATIVELY SMALL FALL OVER DAYTIME HIGHS. THE PASSAGE OF THE UPPER LOW WILL ALLOW CLOUDS TO DECREASE THURSDAY AFTERNOON WHICH SHOULD ALLOW HIGHS TO WARM SEVERAL DEGREES OVER TODAY DESPITE SIMILAR MID LEVEL TEMPS. FRIDAY THROUGH TUESDAY...THE NEXT FEATURE OF INTEREST IS THE TROUGH MOVING SOUTHEAST ACROSS THE CANADIAN ROCKIES THIS MORNING. PART OF THIS WAVE LOOKS TO SPLIT OFF AND MOVE DUE SOUTH INTO THE CENTRAL ROCKIES WHILE THE REST TRACKS SOUTHEAST ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. ALL OF THIS ENERGY WILL RESULT IN A NEW LONGWAVE TROUGH RIGHT ACROSS THE MID SECTION OF THE COUNTRY. A WAVE WILL THEN ZIP NORTHEAST ACROSS THE AREA FRIDAY EVENING/NIGHT BRINGING A LOW CHANCE FOR POPS ACROSS THE AREA...ESPECIALLY SOUTHEAST. THE LONGWAVE WILL SHIFT EASTWARD SATURDAY INTO SUNDAY WHICH WILL ALLOW EVEN COLDER MID LEVEL AIR TO SPREAD INTO THE AREA...WITH H85 TEMPS FALLING BELOW 0C. PRECIP CHANCES LOOK LESS COHERENT BUT OVERALL MINIMAL SATURDAY AND SUNDAY...THOUGH LAKE EFFECT SHOWERS LOOK TO BE IN FULL SWING EAST OF LAKE MICHIGAN. HIGHS WILL BE IN THE 50S SATURDAY AND SUNDAY. ADDITIONAL ENERGY WILL TRACK SOUTHEAST ACROSS CENTRAL CANADA INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES LATER SUNDAY THROUGH TUESDAY. THIS WILL LEAD TO ADDITIONAL PRECIP CHANCES AND CONTINUED COOL TEMPERATURES BUT THE DETAILS ARE UNCLEAR AT THIS RANGE. MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * LOWER END MVFR STRATUS DECK. * POTENTIAL FOR PATCHY DRIZZLE THROUGH THIS AFTERNOON. * CHANCE OF SHOWERS TOMORROW MORNING. KREIN //DISCUSSION...UPDATED 18Z... MAIN ISSUE FOR THE REMAINDER OF THE AFTERNOON AND THROUGH MUCH OF THE NIGHT WILL CONTINUE TO BE CIGS. LATEST SATELLITE IMAGERY INDICATES A WIDESPREAD AREA OF STRATUS UNDER AN UPPER TROUGH...IN THE WAKE OF AN EXITING UPPER LOW MOVING OFF TO THE NORTHEAST. WHILE THERE ARE A FEW ISOLD AREAS OF IFR CIGS...THE GREATER PORTION OF THE ST DECK IS AT THE LOWER END OF MVFR. WHILE THERE IS A CHANCE FOR SOME IFR CIGS TO SNEAK INTO THE TERMINALS...RFD WOULD BE THE MOST LIKELY LOCATION AND ONLY FOR A BRIEF TIME AS THE UPPER TROUGH AXIS IS OVERHEAD. OTHERWISE...EXPECT A SLOW RECOVERY OF CIGS...AND DO NOT ANTICIPATE IMPROVEMENT TO VFR UNTIL TOMORROW MORNING. SINCE THE SATURATED LAYER IS RELATIVELY SHALLOW...THERE WILL STILL BE A CHANCE FOR SOME SCT SPRINKLES OR DRIZZLE THROUGH THE AFTERNOON AND INTO THE EVENING...BUT DO NOT ANTICIPATE A PREVAILING PCPN CONDITION OR SGFNT REDUCTION IN VIS DUE TO PCPN...OR BR AS DEWPOINTS WILL TREND LOWER THROUGH THE PERIOD AS WELL. THERE WILL BE ANOTHER CHANCE FOR SOME SHOWERS TOMORROW AS ANOTHER UPPER LEVEL WAVES TRACKS ACROSS THE MIDWEST...BUT THE LATEST GUIDANCE SUGGESTS THAT THE TRACK OF THIS FEATURE WILL BE CLOSER TO CNTRL IL/NRN INDIANA. THIS WOULD SUGGEST THAT THE GREATEST CHANCES FOR PCPN WILL BE SOUTH AND EAST OF THE TERMINALS...SO WILL ONLY INCLUDE A VCSH MENTION FOR PCPN AT THIS TIME. KREIN //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN MVFR CIGS THROUGH THE REST OF THIS AFTERNOON AND THROUGH TONIGHT. CHANCES THAT CIGS WILL DROP TO IFR ARE LOW...BUT NOT TOTALLY OUT OF THE QUESTION...ESPECIALLY THIS AFTERNOON. * MODERATE CONFIDENCE IN TIMING OF CIGS IMPROVING TO VFR TOMORROW MORNING. * MODERATE CONFIDENCE THAT THERE WILL BE LITTLE OR NO IMPACT FROM PCPN ON THE TERMINALS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...VFR. SATURDAY...SLT CHC SHRA. SUNDAY...VFR. MONDAY...CHC SHRA. TUESDAY...SLT CHC SHRA. BMD && .MARINE... 124 PM CDT A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL TRAVERSE THE LAKES THIS AFTERNOON THROUGH SUNDAY. A BRIEF HIGH PRESSURE RIDGE WILL THEN BUILD IN SUNDAY AFTERNOON AND EVENING BEFORE ANOTHER LOW MOVES IN MONDAY. GENERALLY WESTERLY FLOW WILL PREVAIL THROUGH THE PERIOD. WINDS GUSTING TO 25 KTS THIS AFTERNOON WILL BE DIMINISHING OVERNIGHT. WITH THE GUSTY WEST WINDS AND WAVES AROUND 4 FT AT MICHIGAN CITY THIS AFTERNOON...WILL CONTINUE WITH THE SMALL CRAFT ADVISORY FOR INDIANA SHORES EAST OF BURNS HARBOR INTO THE EVENING. WINDS WILL RAMP UP AGAIN SATURDAY INTO SUNDAY MORNING...GUSTING TO 25 TO 30 KTS...ESPECIALLY OVER THE SOUTH HALF OF THE LAKE. AN UPPER LOW MOVING OVER THE NORTH PART OF THE LAKE THURSDAY AFTERNOON AND MARGINALLY COLD TEMPERATURES ALOFT WILL PRODUCE A LOW END THREAT FOR A WATERSPOUT. ALLSOPP && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1259 PM CDT Wed Oct 16 2013 .DISCUSSION... ISSUED 1045 AM CDT Wed Oct 16 2013 Will be updating the forecast for cooler highs today (mid 50s IL river valley and lower 60s southeast IL) and increase cloud cover, similar to what we did yesterday. Otherwise rest of forecast looks on track today with breezy west winds of 10 to 20 mph and gusts of 20 to 25 mph. 1002 mb low pressure was over the eastern end of upper mi penisula with its cold front slicing through western Ohio and central KY and west TN while a secondary frontal trof was over central WI into southeast IA. Strong 550 dm 500 mb low was ne of Lake Superior with a large upper level trof extending sw into IA/NE and southern CO and northern NM where a short wave was. Low clouds over much of central and nw IL as far southeast as Mattoon and also mid level cloud deck southeast of I-70. Models show upper level trof pivoting se toward central IL and moving into the state on Thursday as short wave ejects from southern CO/northern NM toward the region. This should keep more clouds over central and nw parts of CWA while some sunshine over southeast IL allows for milder highs in the lower 60s. Temps currently in the lower 50s with Bloomington and Galesburg still at 49F. 07 && .AVIATION... ISSUED 1257 PM CDT Wed Oct 16 2013 MVFR ceilings of 1.5-3k feet (currently as far se as MTO) will occur across the central IL terminal airports through tonight and scatter out from west to east after 15Z/Thu. Cloud deck is 1-2k ft thick and will have breaks in it at times like currently at BMI. Have VCSH moving in from 08Z- 10Z from west to east and ending from 15-18Z due to a short wave in the 4 corners ejecting northeast to near St Louis by 12Z Thu and passing ne of central IL by 18Z Thu. VFR visibilies are expected to prevail next 24 hours. Breezy west winds of 10-15 kts with gusts 17-22 kts this afternoon to become light sw this evening and veer more westerly and increaing to 9-13 kts after 15Z Thu. 07 && .PREV DISCUSSION... ISSUED 243 AM CDT Wed Oct 16 2013 Latest surface map shows low pressure over the eastern part of the Michigan Upper Peninsula. The cold front extends southwest, and shows up as a narrow fine line through extreme southwest Indiana per radar imagery from the Evansville radar. Narrow clear slot just west of the Illinois River was about to be overtaken by a large stratocumulus deck from the northwest, and excessive mid and high clouds have been streaming northeast along the front across most of the forecast area. Main concern in the short term is with trying to time any cloud breakup today, followed by rain chances late tonight and early Thursday. Longer range issues focus on early weekend storm system and the cool weather trend which will last much of the forecast period. SHORT TERM...Today through Thursday... Latest RAP model guidance showing the mid/high clouds shifting south toward the Ohio Valley later today, as the stratocumulus pushes south of the I-72 corridor, although the NAM shows some decent break up by late morning. Given the expansive nature of the clouds, stretching all the way into northern Minnesota, will go with the more pessimistic route and keep skies mostly cloudy across the central and northern CWA today, with a bit of sunshine over the south. Went a couple degrees below the MOS guidance for highs, but this may need to be adjusted downward later if we are unable to get any breaks to develop. Shortwave currently near the 4 Corners region will zip eastward later today. 00Z model guidance closes this off as it reaches the Iowa/Illinois border toward sunrise Thursday, but ranges quite a bit in terms of any precipitation over our area. NAM is nearly dry with most of the precip near the remains of the earlier frontal boundary south of the Ohio River, while the GFS has a narrow rain axis just east of I-55. The ECMWF and Canadian models are much more bullish with widespread showers. Currently leaning toward more of the GFS solution but a bit more widespread with the showers Thursday morning, fairly similar in coverage to the earlier grids. However, am thinking that much of this will be out of the area by early afternoon, although some slight chance PoP`s will be in the afternoon forecast across the east. LONG TERM...Friday through Tuesday... A deepening upper trough over the central U.S. will be the main player this weekend, as a wedge of colder air drops southward from Canada. Some potential exists for light rain Friday night or early Saturday as the trough axis starts to shift eastward, but will maintain 20% PoP`s at this time. Some frost potential for Saturday night as winds lighten and temperatures fall into the upper 30s over the northern half of the CWA. Going into early next week, periodic lobes of energy will drop southward across the Midwest. The latest ECMWF remains quite chilly similar to the past couple runs, with 850 mb temperatures falling to around -5C by midweek, although the GFS is several degrees warmer. For now, have not strayed too far from the guidance, which keeps temperatures fairly similar throughout the period. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1101 AM CDT WED OCT 16 2013 .DISCUSSION... 306 AM CDT COOL AND PERIODICALLY DAMP WEATHER WILL DESCRIBE THE FORECAST PERIOD AS AN AMPLIFIED AND ACTIVE PATTERN SETS UP. WATER VAPOR SATELLITE IMAGERY SHOWS A LONGWAVE TROUGH THAT EXTENDS FROM JAMES BAY BACK ACROSS THE CENTRAL PLAINS TO THE FOUR CORNERS. A LARGE NORTH-SOUTH RIDGE IS IN PLACE OFF THE WEST COAST WHILE A MORE PROGRESSIVE FLOW IS FOUND OVER CENTRAL CANADA WHERE ANOTHER TROUGH AXIS IS TRANSLATING SOUTHEASTWARD. AT THE SURFACE...A LOW IS MOVING NORTHEAST ACROSS FAR NORTHERN LAKE MICHIGAN WHICH WAS RESPONSIBLE FOR PUSHING A COLD FRONT ACROSS THE AREA LAST EVENING. A RIBBON OF HIGH PRESSURE STRETCHES FROM THE PACIFIC NORTHWEST TO THE CENTRAL HIGH PLAINS. TODAY...MANY CONCERNS THIS PERIOD RANGING FROM CLOUDS AND STRATUS TO DRIZZLE. THE UPPER TROUGH EXTENDING FROM JAMES BAY SOUTHWEST HAS A CLOSED CIRCULATION EMBEDDED WITHIN IT OVER CENTRAL WISCONSIN. THIS CLOSED CIRCULATION IS EXPECTED TO OPEN UP/WEAKEN WITH THE MAIN LONGWAVE TROUGH PIVOTING ACROSS THE AREA TODAY. IR SATELLITE SHOWS A VERY LARGE AREA OF STRATUS SPREADING EASTWARD ACROSS THE LOCAL AREA. WITH THE UPPER LOW WEAKENING AS IT ARRIVES...UPWARD MOTION WILL BE DIMINISHING THROUGH THE MORNING AND HAVE SEEN THIS ALREADY OCCURRING TO THE NORTH WHERE SHOWER COVERAGE/INTENSITY HAS BEEN WANING. WITH THE EXTENSIVE STRATUS IN PLACE SURFACE WARMING WILL BE LIMITED LEAVING LOW AND MID LEVEL LAPSE RATES MEAGER. WITH THIS IN MIND EXPECT THAT THE FOCUS FOR SHOWERS WILL REMAIN NORTH OF THE AREA LEADING TO LOWER/MINIMAL POPS ACROSS NORTHERN SECTIONS OF THE LOCAL AREA. WILL GO AHEAD AND ADD DRIZZLE ACROSS NORTHERN AREAS THROUGH THE MORNING HOWEVER WITH A DECENT DEPTH OF MOISTURE AND SOME WEAK ASCENT. UPSTREAM OBS OVER THE PAST SEVERAL HOURS HAVE ALSO SHOWN A FAIR AMOUNT OF DRIZZLE. AS ALLUDED TO...THE STRATUS WILL MAKE TEMPS A CHALLENGE. STRATUS DOES LOOK TO HOLD ON THROUGH THE AFTERNOON AND WILL COMBINE WITH LOW LEVEL COLD ADVECTION TO REALLY LIMIT WARMING. UNLESS SOME BREAKS CAN DEVELOP LATE IN THE DAY ALLOWING SOME MINIMAL SUNSHINE...DO NOT EXPECT MORE THAN ABOUT A 3-5 DEGREE DIURNAL INCREASE IN TEMPS FROM MORNING LOW...QUITE A BIT COOLER THAN MOST GUIDANCE. WILL THEREFORE KEEP HIGHS IN THE LOWER 50S IN NORTHERN AREAS TO THE MID EVEN UPPER 50S FAR SOUTH...WITH A BETTER CHANCE FOR SOME SUNSHINE OVER THE EXTREME SOUTHERN PORTIONS OF THE AREA. TONIGHT THROUGH THURSDAY...ATTENTION TURNS TO THE BASE OF THE LONGWAVE UPPER TROUGH OVER THE FOUR CORNERS WHERE ANOTHER CLOSED CIRCULATION IS TAKING SHAPE. THIS LOW WILL EJECT NORTHEASTWARD AND ACROSS THE AREA THURSDAY MORNING. THIS WILL BRING ANOTHER ROUND OF SHOWERS TO MUCH OF THE AREA...ESPECIALLY THE SOUTHEAST TWO-THIRDS... STARTING LATE TONIGHT AND CONTINUING THURSDAY MORNING. TEMPS TONIGHT WILL BE DEPENDENT ON CLOUD COVER. THE LOW CLOUDS LOOK TO HANG ON THROUGH THE EVENING IF NOT THROUGH THE NIGHT. MID CLOUDS WILL BE INCREASING AHEAD OF THE APPROACHING TROUGH OVERNIGHT. WITH SOME QUESTION ABOUT HOW LONG THE LOW CLOUDS WILL HANG ON AND IF THERE WILL BE A BREAK IN CLOUD COVER BEFORE THE HIGHER CLOUDS ARRIVE WILL ONLY RAISE OVERNIGHT LOWS A FEW DEGREES IN MOST AREAS FOR NOW...WITH POTENTIAL FOR ONLY A RELATIVELY SMALL FALL OVER DAYTIME HIGHS. THE PASSAGE OF THE UPPER LOW WILL ALLOW CLOUDS TO DECREASE THURSDAY AFTERNOON WHICH SHOULD ALLOW HIGHS TO WARM SEVERAL DEGREES OVER TODAY DESPITE SIMILAR MID LEVEL TEMPS. FRIDAY THROUGH TUESDAY...THE NEXT FEATURE OF INTEREST IS THE TROUGH MOVING SOUTHEAST ACROSS THE CANADIAN ROCKIES THIS MORNING. PART OF THIS WAVE LOOKS TO SPLIT OFF AND MOVE DUE SOUTH INTO THE CENTRAL ROCKIES WHILE THE REST TRACKS SOUTHEAST ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. ALL OF THIS ENERGY WILL RESULT IN A NEW LONGWAVE TROUGH RIGHT ACROSS THE MID SECTION OF THE COUNTRY. A WAVE WILL THEN ZIP NORTHEAST ACROSS THE AREA FRIDAY EVENING/NIGHT BRINGING A LOW CHANCE FOR POPS ACROSS THE AREA...ESPECIALLY SOUTHEAST. THE LONGWAVE WILL SHIFT EASTWARD SATURDAY INTO SUNDAY WHICH WILL ALLOW EVEN COLDER MID LEVEL AIR TO SPREAD INTO THE AREA...WITH H85 TEMPS FALLING BELOW 0C. PRECIP CHANCES LOOK LESS COHERENT BUT OVERALL MINIMAL SATURDAY AND SUNDAY...THOUGH LAKE EFFECT SHOWERS LOOK TO BE IN FULL SWING EAST OF LAKE MICHIGAN. HIGHS WILL BE IN THE 50S SATURDAY AND SUNDAY. ADDITIONAL ENERGY WILL TRACK SOUTHEAST ACROSS CENTRAL CANADA INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES LATER SUNDAY THROUGH TUESDAY. THIS WILL LEAD TO ADDITIONAL PRECIP CHANCES AND CONTINUED COOL TEMPERATURES BUT THE DETAILS ARE UNCLEAR AT THIS RANGE. MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * LOWER END MVFR STRATUS DECK. * POTENTIAL FOR PATCHY DRIZZLE THROUGH THIS AFTERNOON. KREIN //DISCUSSION...UPDATED 12Z... MAIN STORY TODAY WILL BE BROAD STRATUS DECK THAT IS EXPECTED TO IMPACT THE AREA WITH MVFR CIGS THROUGH THE REMAINDER OF THE AND POSSIBLY THROUGH THE OVERNIGHT HOURS. LOW PRESSURE IS LIFTING ACROSS EASTERN LAKE SUPERIOR INTO ONTARIO THIS MORNING WITH TROUGHING EXTENDING SOUTHWEST ACROSS WISCONSIN AND INTO EASTERN IOWA. STRATUS DECK EXTENDS ACROSS MUCH OF THE UPPER MIDWEST...AND IS EXPECTED TO VERY GRADUALLY SLIDE EAST THROUGH THE TAF PERIOD. WHILE THE SOUTHERN HALF OF THE CLOUD COVER IS MAINLY MVFR...IFR CIGS ARE WIDESPREAD ACROSS WISCONSIN AND NORTHEASTERN IOWA...PRIMARILY WITHIN THE TROUGH AXIS. IFR CIGS MAY REACH RFD THIS MORNING...HOWEVER BY THE TIME THE TROUGH MOVES INTO THE CHICAGO AREA...IT WILL WEAKEN WITH WEAK PRESSURE RISES AT THE SURFACE...MAKING IT LESS LIKELY FOR IFR INTO THE CHICAGO TERMINALS. MOST GUIDANCE ONCE AGAIN STRUGGLING BUT THE NAM SEEMS TO HAVE DECENT OF A HANDLE ON THE LOW LEVEL MOISTURE PROFILE...KEEPING MOISTURE IN PLACE THOUGH THE OVERNIGHT HOURS THEN DEPARTING EAST TOMORROW AFTERNOON. THERE IS ALSO A SLIGHT CONCERN FOR SOME PATCHY DRIZZLE DEVELOPING LATE THIS MORNING AS A SHEARED UPPER LEVEL DISTURBANCE MOVES ACROSS THE AREA. BEST TIME FRAME WOULD BE FROM 15Z TO 18Z...AND IT COULD REDUCE VISIBILITY TO 4-5SM...BUT TOO LOW CONFIDENCE RIGHT NOW TO INCLUDE IN THE TAF. BMD //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM TO HIGH CONFIDENCE IN MVFR CIGS THROUGH THE REST OF TODAY AND TONIGHT. LOW CONFIDENCE IN CHANCES FOR CIGS TO DROP TO IFR. * LOW CONFIDENCE IN SGFNT DRIZZLE IMPACTING TERMINALS. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...VFR. FRIDAY...VFR. SATURDAY...SLT CHC SHRA. SUNDAY...VFR. MONDAY...CHC SHRA. TUESDAY...SLT CHC SHRA. BMD && .MARINE... 258 AM CDT LOW PRESSURE LIES OVER NORTHERN LAKE MICHIGAN THIS MORNING WITH A TRAILING COLD FRONT STRETCHING WEST ACROSS WISCONSIN INTO IOWA. WINDS ARE STRONGEST ACROSS THE SOUTHERN HALF OF THE LAKE WHERE 30 KTS ARE EXPECTED TO CONTINUE...THEN SHOULD BEGIN TO TAPER THIS AFTERNOON. A SMALL CRAFT ADVISORY WILL BE HOISTED FOR THE INDIANA NEARSHORE WATERS EAST OF BURNS HARBOR THROUGH LATE THIS EVENING. STRONGER WINDS ARE EXPECTED LATE THIS MORNING AND EARLY AFTERNOON ACROSS THE NORTHERN HALF OF THE LAKE AS THE COLD FRONT PUSHES ACROSS ALLOWING WINDS TO INCREASE WITH 30 KT GUSTS EXPECTED. WINDS WILL TAPER ACROSS THE ENTIRE LATE TONIGHT AS ANOTHER TROUGH DROPS INTO THE WESTERN LAKES REGION ALLOWING THE GRADIENT TO WEAKEN. WINDS BEGIN TO INCREASE AGAIN ON SATURDAY AS ANOTHER LOW DROPS SOUTHEAST ACROSS THE CANADIAN PRAIRIES THEN PIVOTS EAST ACROSS THE NORTHERN LAKES REGION. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE BURNS HARBOR TO MICHIGAN CITY IN UNTIL 10 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1044 AM CDT Wed Oct 16 2013 .DISCUSSION... ISSUED 1045 AM CDT Wed Oct 16 2013 Will be updating the forecast for cooler highs today (mid 50s IL river valley and lower 60s southeast IL) and increase cloud cover, similar to what we did yesterday. Otherwise rest of forecast looks on track today with breezy west winds of 10 to 20 mph and gusts of 20 to 25 mph. 1002 mb low pressure was over the eastern end of upper mi penisula with its cold front slicing through western Ohio and central KY and west TN while a secondary frontal trof was over central WI into southeast IA. Strong 550 dm 500 mb low was ne of Lake Superior with a large upper level trof extending sw into IA/NE and southern CO and northern NM where a short wave was. Low clouds over much of central and nw IL as far southeast as Mattoon and also mid level cloud deck southeast of I-70. Models show upper level trof pivoting se toward central IL and moving into the state on Thursday as short wave ejects from southern CO/northern NM toward the region. This should keep more clouds over central and nw parts of CWA while some sunshine over southeast IL allows for milder highs in the lower 60s. Temps currently in the lower 50s with Bloomington and Galesburg still at 49F. 07 && .AVIATION... ISSUED 700 AM CDT Wed Oct 16 2013 The surface low is progressing farther to the NE into the Great Lakes, while the cold front departs through Indiana. Wrap around moisture in Minnesota and Iowa has already reached PIA and SPI, and those MVFR clouds at 2-2.5K feet will reach all the way to DEC and CMI by 13z. A couple of hours of IFR clouds between 700-900 ft are being reported back across Iowa. Mixing and daytime heating should help to lift those ceilings above 1000 ft by the time that area reaches PIA around 16z. So no IFR conditions were included in the 12z TAF issuance. Ceilings may climb above 3k ft to VFR levels later this afternoon, but chances are that they will return to MVFR in the evening. We cant rule out some light drizzle or sprinkles today as a surface trough reaches IL later today. We will monitor those trends but keep a dry forecast for now. Winds will increase from the west this morning, with sustained speeds of 12-14kt and gusts to 22kt at times. Winds should diminish below 10kt by evening Shimon && .PREV DISCUSSION... ISSUED 243 AM CDT Wed Oct 16 2013 Latest surface map shows low pressure over the eastern part of the Michigan Upper Peninsula. The cold front extends southwest, and shows up as a narrow fine line through extreme southwest Indiana per radar imagery from the Evansville radar. Narrow clear slot just west of the Illinois River was about to be overtaken by a large stratocumulus deck from the northwest, and excessive mid and high clouds have been streaming northeast along the front across most of the forecast area. Main concern in the short term is with trying to time any cloud breakup today, followed by rain chances late tonight and early Thursday. Longer range issues focus on early weekend storm system and the cool weather trend which will last much of the forecast period. SHORT TERM...Today through Thursday... Latest RAP model guidance showing the mid/high clouds shifting south toward the Ohio Valley later today, as the stratocumulus pushes south of the I-72 corridor, although the NAM shows some decent break up by late morning. Given the expansive nature of the clouds, stretching all the way into northern Minnesota, will go with the more pessimistic route and keep skies mostly cloudy across the central and northern CWA today, with a bit of sunshine over the south. Went a couple degrees below the MOS guidance for highs, but this may need to be adjusted downward later if we are unable to get any breaks to develop. Shortwave currently near the 4 Corners region will zip eastward later today. 00Z model guidance closes this off as it reaches the Iowa/Illinois border toward sunrise Thursday, but ranges quite a bit in terms of any precipitation over our area. NAM is nearly dry with most of the precip near the remains of the earlier frontal boundary south of the Ohio River, while the GFS has a narrow rain axis just east of I-55. The ECMWF and Canadian models are much more bullish with widespread showers. Currently leaning toward more of the GFS solution but a bit more widespread with the showers Thursday morning, fairly similar in coverage to the earlier grids. However, am thinking that much of this will be out of the area by early afternoon, although some slight chance PoP`s will be in the afternoon forecast across the east. LONG TERM...Friday through Tuesday... A deepening upper trough over the central U.S. will be the main player this weekend, as a wedge of colder air drops southward from Canada. Some potential exists for light rain Friday night or early Saturday as the trough axis starts to shift eastward, but will maintain 20% PoP`s at this time. Some frost potential for Saturday night as winds lighten and temperatures fall into the upper 30s over the northern half of the CWA. Going into early next week, periodic lobes of energy will drop southward across the Midwest. The latest ECMWF remains quite chilly similar to the past couple runs, with 850 mb temperatures falling to around -5C by midweek, although the GFS is several degrees warmer. For now, have not strayed too far from the guidance, which keeps temperatures fairly similar throughout the period. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1217 PM CDT WED OCT 16 2013 .UPDATE... ISSUED AT 1210 PM CDT WED OCT 16 2013 THE EARLIER CONCERN IS BEING REALIZED...TEMPERATURES ARE BARELY MOVING IF AT ALL. THUS MAX TEMPERATURES ARE BEING LOWERED AGAIN. SATELLITE TRENDS SHOW DIURNAL COLD WX CLOUDS DEVELOPING ON THE BACK SIDE OF THE LOW CLOUDS. THESE CLOUDS WILL PERSIST THROUGH SUNSET AND THEN DISSIPATE. HOWEVER...THE EFFECT WILL BE TO DELAY ANY CLEARING FURTHER. TRENDS FROM THE RAP ARE NOW POINTING TO KEEPING CLOUDS ACROSS MOST OF THE AREA THROUGH SUNRISE WITH CLEARING ON THURSDAY AS THE UPPER LEVEL DISTURBANCE MOVES NORTHEAST. THUS MIN TEMPERATURES FOR TONIGHT HAVE BEEN RAISED IN ANTICIPATION OF CLOUDS REMAINING ACROSS THE AREA. ..08.. UPDATE ISSUED AT 1028 AM CDT WED OCT 16 2013 SPOTTY DRIZZLE APPEARS TO BE ASSOCIATED WITH LIFT FROM THE 700 AND 500MB TROFS AND LOW CONDENSATION PRESSURE DEFICITS AT 700MB. RAP TRENDS HAVE THE OVERALL LIFT DISSIPATING DURING THE AFTERNOON SUGGESTING THE POTENTIAL FOR DRIZZLE INTO THE EARLY AFTERNOON. IF THE TRENDS WITH THE RAP ARE CORRECT...AREAS GENERALLY ALONG/NORTH OF HWY 30 WOULD BE FAVORED FOR DRIZZLE. TEMPERATURES SO FAR HAVE RESPONDED A FEW DEGREES SINCE THE OVERNIGHT MINS. TRENDS WILL BE MONITORED BUT THE POTENTIAL EXISTS FOR ANOTHER LOWERING OF MAX TEMPERATURES BY A FEW MORE DEGREES. UPDATE ISSUED AT 842 AM CDT WED OCT 16 2013 BASED ON CURRENT SATELLITE TRENDS...CLEARING LOOKS DOUBTFUL PRIOR TO SUNSET. RECENT RAP TRENDS ALSO SUGGEST CLOUDS REMAINING ACROSS THE AREA AS WELL DURING THE DAYLIGHT HOURS. CLOUD COVER COMBINED WITH THE WEAKENING OCTOBER SUN INDICATE A VERY SMALL DIURNAL RISE IN TEMPERATURES DURING THE DAY. ..08.. && .SYNOPSIS... ISSUED AT 300 AM CDT WED OCT 16 2013 A POSITIVELY TILTED UPPER TROF EXTENDED FROM THE WESTERN GREAT LAKES INTO SOUTHERN CA AND AZ TUESDAY EVENING. A SURFACE LOW WAS LOCATED OVER LAKE SUPERIOR WITH CYCLONIC FLOW AROUND THE LOW EXTENDING WEST INTO SOUTHWESTERN MN AND WESTERN IA. WIDESPREAD LOW CLOUDS WERE ASSOCIATED WITH THE CYCLONIC FLOW. SOME PATCHY DRIZZLE OR LIGHT RAIN WAS OCCURRING FROM CENTRAL MN INTO NORTHERN IA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CDT WED OCT 16 2013 CLOUDS TRENDS WILL BE THE MAIN CONCERN TODAY AND TONIGHT AS THE GREAT LAKES SURFACE LOW MOVES OFF TO THE NORTHEAST AND THE TRAILING CYCLONIC FLOW WEAKENS. THE LOW CLOUDS HAVE OVERSPREAD THE ENTIRE AREA EARLY THIS MORNING AND EXTEND INTO EASTERN NE AND SOUTH DAKOTA SO IT/S DOUBTFUL THAT ANY CLEARING WILL OCCUR TODAY WITH THE CYCLONIC FLOW REMAINING OVER THE AREA. PATCHY DRIZZLE OR LIGHT RAIN SHOULD BE CONFINED TO THE NORTHERN HALF OF THE FORECAST AREA TODAY. THERE IS SOME DISAGREEMENT BETWEEN THE MODELS ON CLEARING TONIGHT. THE GFS SUGGESTS THE WEST WILL SEE SOME CLEARING LATE WHILE THE NAM HOLDS HIGH H8 RH OVER THE ENTIRE AREA THROUGH 12Z THURSDAY ALONG WITH SOME WEAK LOW LEVEL CONVERGENCE...SUPPORTING LITTLE IF ANY CLEARING. IF THE LOW CLOUDS WOULD CLEAR OVER PARTS OF THE AREA TONIGHT...ANY CLEARING SHOULD BE BRIEF WITH MID/HIGH CLOUDS SPREADING OVER THE AREA AHEAD OF A S/W LIFTING OUT OF THE SOUTHWESTERN U.S. THE S/W WILL ALSO BRING A LOW CHANCE OF SOME LIGHT RAIN TO THE SOUTHEASTERN THIRD AFTER MIDNIGHT. THE EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES FROM CHANGING MUCH TODAY AND TONIGHT. 50S ARE EXPECTED TODAY WITH OVERNIGHT LOWS IN THE UPPER 30S AND LOWER 40S. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 300 AM CDT WED OCT 16 2013 PATTERN CHANGE TO A PREVAILING NW FLOW TO BRING ABOUT A CHANGE TO BELOW TEMPERATURES BY THE WEEKEND...WHICH WILL REMAIN PLACE THROUGH MUCH OF NEXT WEEK. IN THE TRANSITION...WEAK SYSTEMS WILL BRING PERIODIC CHANCES FOR LIGHT PRECIPITATION LATE THIS WEEK INTO THE WEEKEND. THURSDAY THROUGH FRIDAY NIGHT...VERY LIGHT RAIN OR DRIZZLE ASSOCIATED WITH ISENTROPIC LIFT UNDER THE SHORTWAVE EXITING TO THE EAST WILL BE HANDLED WITH VERY LOW POPS THU MORNING. BY AFTERNOON...A TRANSITORY MID LEVEL SHORTWAVE RIDGE THAT FOLLOWS SHOULD BRING CLEARING SKIES ALLOWING TEMPERATURES TO RECOVER INTO THE LOWER TO MID 60S. ANOTHER SHORTWAVE AND THE BROAD CYCLONIC FLOW ALOFT SHOULD BRING INCREASING CLOUDS OVERNIGHT...BUT WITH THE BEST FORCING WELL TO THE NORTH...WILL NOT ANTICIPATE ANY PRECIPITATION. CLOUD COVER SHOULD CONFINE MINS TO THE UPPER 30S TO LOWER 40S. THE NEXT SYSTEM BRUSHES PAST TO THE SOUTH LATE FRIDAY AND WILL HAVE SLIGHT CHANCE POPS FOR LIGHT RAIN ACROSS THE SOUTH FOR FRIDAY NIGHT. COLD ADVECTION GRADUALLY INCREASES THROUGH THIS PERIOD...AND BY FRIDAY NIGHT...850 MB TEMPERATURES NEAR TO BELOW ZERO CELSIUS ARE PROGGED OVER THE AREA. WILL THUS NEED DEEP MIXING TO REACH HIGHS IN THE 50S FRIDAY...THEN CLOUD COVER TO MAINTAIN LOWS IN THE MID TO UPPER 30S FRIDAY NIGHT. OVER THE WEEKEND...THE NEXT SHORTWAVE IS GENERALLY DEPICTED PASSING TO THE NORTH AROUND SATURDAY NIGHT...AND WILL MAINTAIN ONLY SLIGHT CHANCES FOR RAIN IN THE FAR NORTH. OTHERWISE...IMPROVING MODEL CONSISTENCY...BOTH FROM RUN TO RUN AND BETWEEN MODELS...SHOW 850 MB TEMPERATURES COOLING TO ZERO TO 4 BELOW BY SUNDAY SUPPORT WELL BELOW NORMAL SURFACE TEMPERATURES. ADVERTISED HIGHS IN THE 50S MAY BE TOO OPTIMISTIC...ESPECIALLY SUNDAY DEPENDING ON CLOUD TRENDS. LIKEWISE...CURRENT OVERNIGHT LOWS COULD POTENTIALLY BE COLD ENOUGH FOR A WIDESPREAD KILLING FREEZE...ESPECIALLY SUNDAY MORNING. HOWEVER...FOR NOW...WITH UNCERTAINTIES IN CLOUD COVER AND THE TIMING OF PASSING SURFACE RIDGE AXIS...LOWS WILL BE MAINTAINED IN THE 30S. NEXT WEEK...A CYCLONIC NW FLOW WITH PERIODIC SHORTWAVES AND REINFORCING SURFACE COLD FRONTS SETS UP OVER THE AREA THROUGH MOST OF THE WEEK. THERE IS HIGH CONFIDENCE THAT MUCH OF THE WEEK WILL FEATURE BELOW TO WELL BELOW NORMAL TEMPERATURES. HOWEVER... CHALLENGES WITH THE CRITICAL TIMING AND STRENGTH OF PASSING SHORTWAVES MAKES THIS A LOW PREDICTABILITY PATTERN THIS FAR OUT. FOR NOW...THERE IS ENOUGH CONSENSUS IN THE MODEL BLENDS TO PLACE LOW CHANCE POPS OVER MAINLY THE NORTH FOR SUNDAY NIGHT INTO MONDAY...AND THEN MORE WIDESPREAD HIGHER CHANCES FOR TUE INTO TUE NIGHT. THE LATEST GFS AND ECMWF INDICATE A STRONG SURGE OF COLD AIR BEHIND TUESDAY NIGHT/S COLD FRONT...THAT COULD LIMIT MIDWEEK HIGHS TO THE UPPER 30S OVER AT LEAST THE NORTH AND RESULT IN WIDESPREAD 20S FOR LOWS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1210 PM CDT WED OCT 16 2013 MVFR CONDITIONS WITH A FEW POCKETS OF IFR CIGS WILL PERSIST THROUGH 00Z/17 AS MOISTURE REMAINS TRAPPED BELOW THE INVERSION. AFT 00Z/17 MVFR CONDITIONS WILL CONTINUE WITH A SLOW IMPROVEMENT TO VFR CIGS. AFT 12Z/17 CLEARING WILL COMMENCE FROM SOUTHWEST TO NORTHEAST. ..08.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...DLF SHORT TERM...DLF LONG TERM...SHEETS AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
247 PM EDT WED OCT 16 2013 .UPDATE... ISSUED AT 235 PM EDT WED OCT 16 2013 HOURLY GRIDS WERE FRESHENED UP BASED ON RECENT RADAR AND OBSERVATION TRENDS. MAX T HAS LIKELY ALREADY BEEN REACHED IN THE EASTERN PAR OF THE CWA AND LOCATIONS IN THE CUMBERLAND VALLEY AND NEAR THE TN BORDER WILL PROBABLY ONLY CLIMB ANOTHER COUPLE OF DEGREES AT THE MOST. SHOWER ACTIVITY ACTIVITY SHOULD INCREASE A BIT IN THE EVENING...WITH SHOWERS ANTICIPATED TO BE MORE WIDESPREAD...ESPECIALLY SOUTHEAST CWA LATE TONIGHT AND ON THURSDAY. UPDATE ISSUED AT 1055 AM EDT WED OCT 16 2013 ISOLATED TO SCATTERED SHOWERS CONTINUE TO WORK ACROSS EASTERN KY WITH TRACE OR GENERALLY LIGHT RAINFALL SO FAR OF A FEW HUNDREDTHS OF AN INCH...IF THAT. THE SHORT TERM MODELS...ESPECIALLY THE HRRR POINT TOWARD THE NEXT WAVE NOW OVER MIDDLE AND WESTERN TN TO WORK INTO THE AREA THIS AFTERNOON...AFFECTING THE SW PART OF THE ARE IN PARTICULAR. WITH THE DENSE CLOUD COVER SO FAR...TEMPS WERE RUNNING BEHIND THE PREVIOUS FORECAST IN THEIR CLIMB THIS MORNING. WITH THAT IN MIND...HOURLY TEMPS AS WELL AS MAX T WERE ADJUSTED DOWN A FEW DEGREES ACROSS THE BOARD. THE INCOMING MET MOS GUIDANCE SUPPORTS THIS CHANGE AS WELL. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 402 AM EDT WED OCT 16 2013 SHOWERS CONTINUE TO SKIRT ALONG THE EDGE OF THE CWA...COVERING PORTIONS OF CENTRAL KY...BUT REMAINING VERY LIGHT IN NATURE. IN FACT...MOST STATIONS ALONG THE CENTRAL PORTION OF THE STATE ARE NOT EVEN PICKING UP ANY MEASURABLE PRECIP. AS SUCH...EXPECT SHOWERS TO MAKE THEIR WAY INTO THE CWA OVER THE NEXT COUPLE OF HOURS...WHILE REMAINING LIGHT IN NATURE. LATEST HI-RES MODELS SHOW PRECIP INTENSIFYING IN COVERAGE DURING THE DAY TIME HOURS...AS THE LINE MAKES IT/S WAY EASTWARD ACROSS THE STATE. DON/T EXPECT MORE THAN A QUARTER INCH OF ACCUMULATION BY 6Z TONIGHT. THE COLD FRONT FOR WHICH THIS PRECIP IS ASSOCIATED WITH WILL PUSH INTO EASTERN KY BY 18Z TODAY. AS IT PASSES...PLACES ACROSS CENTRAL KY...AND POSSIBLY OUR FAR NORTHERN COUNTIES...CAN EXPECT SOME BRIEF CLEARING AS DRIER AIR FILTERS IN. HOWEVER...BY 0Z THIS EVENING...THE FRONT WILL STALL OUT ACROSS THE FAR EASTERN CWA...PIVOTING SOUTHWARD BUT MAKING NO EASTWARD PROGRESSION. THIS WILL KEEP A PULL OF MOISTURE FROM THE ATLANTIC INTO THE APPALACHIAN REGION...AND ENOUGH ISENTROPIC LIFT TO ALLOW LIKELY SHOWERS TO CONTINUE/REDEVELOP ACROSS MUCH OF THE CWA. AN ADDITIONAL QUARTER TO HALF INCH IS POSSIBLE IN SOME LOCATIONS IN THE CWA...MAINLY THE FAR SOUTHEASTERN FRINGES OF THE STATE. THE FRONT WILL THEN FINALLY CONTINUE TO THE SE STARTING 12Z THURSDAY...ALLOWING HIGH PRESSURE TO FINALLY TAKE IT/S PLACE ACROSS STATE THROUGH THE DAY. THE LAST OF THE PRECIP WILL MOVE OUT DURING THE AFTERNOON HOURS...WITH SKIES CLEARING A COUPLE HOURS BEHIND. AS FOR TEMPERATURES...STILL EXPECTING HIGHS TODAY IN THE UPPER 60S TO LOW 70S...WITH THE WARMEST TEMPERATURES BEING FELT ACROSS THE FAR EAST WHERE THE BETTER RAIN CHANCES WILL HOLD OFF THE LONGEST. WITH THE COLD FRONT STALLING AND PIVOTING OVERNIGHT...CLEARING WILL NOT BE AS FAST TO COME AS IN PREVIOUS FORECAST...SO EXPECT MOST OF THE REGION WILL REMAIN IN THE LOW TO MID 50S. THE EXCEPTION WILL BE THE FAR NW SECTION OF THE CWA...WHERE /AS MENTIONED ABOVE/ THE SOUTHWARD PIVOTING WILL BRING IN A BRIEF TIME OF CLEARING BEFORE MOISTURE MOVES BACK IN. LOWS HERE WILL BE SLIGHTLY COOLER...IN THE UPPER 40S. AS FOR HIGHS TOMORROW...RAISED THEM SLIGHTLY COMPARED TO PREVIOUS...DUE TO THE FACT THAT THE MOISTURE AND CLOUDS FROM THE STALLED FRONT WILL STICK AROUND LONGER AND THUS PREVENT COOLER AND DRIER AIR FROM MOVING IN. ONCE FRONT STARTS PROGRESSING EASTWARD DURING THE AFTERNOON...TEMPERATURES WILL BEGIN THEIR DESCENT. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 AM EDT WED OCT 16 2013 THE MODELS CONTINUE TO HAVE PROBLEMS RESOLVING THE EVOLUTION OF A DEEP MID-LEVEL TROUGH OVER THE NORTH CENTRAL PART OF THE COUNTRY LATER THIS WEEKEND. HOWEVER...A QUICK GLANCE AT THE LATEST ECMWF SUGGESTS THAT THERE MAY BE SOME GROWING CONSENSUS AS IT HAS BACKED OFF ITS MORE AMPLIFIED 12Z VERSION OF THE TROUGH. THE DEPARTURE OF A SMALL...BUT POTENT WAVE AT THE START OF THE EXTENDED WILL LEAVE BEHIND FAST...AND RATHER QUIET...SOUTHWEST FLOW OVER THE LOWER OHIO VALLEY INTO THE START OF THE WEEKEND BEFORE A DEEP TROUGH PUSHES EAST FROM THE HIGH PLAINS AND SWEEPS OVER THE AREA. THE BULK OF ITS ENERGY WILL LIFT NORTH INTO THE GREAT LAKES BY 00Z SUNDAY AS HEIGHTS FALL IN ITS WAKE THROUGHOUT THE OHIO VALLEY. VARIOUS WEAKER WAVES WILL THEN PASS THROUGH THE REGION IN GENERAL FAST AND FLAT FLOW. SOME AMPLIFICATION WILL TAKE PLACE LATER MONDAY AS MORE ENERGY POURS INTO THE NORTHERN PLAINS AND THE DEEPER MID CONTINENTAL TROUGH BEGINS TO BECOME REESTABLISHED TO THE NORTH OF THE CWA. GIVEN THE RECENT TROUBLES IN THE MODELS WITH THIS PATTERN WILL CONTINUE TO RESERVE JUDGMENT ON INDIVIDUAL SOLUTIONS AND FAVOR A GENERAL BLEND FOR THE EXTENDED. SENSIBLE WEATHER WILL FEATURE A RELATIVELY DRY...IF SOMEWHAT COOL... EXTENDED AS WEAK HIGH PRESSURE PASSES THROUGH THE AREA UP TO THE START OF THE WEEKEND. A DECENT FRONT WILL CROSS EAST KENTUCKY ON SATURDAY...BUT LOOKS TO BE MOISTURE STARVED WITH THE QPF MAINLY MISSING US TO THE NORTH AND ALSO SOUTH. WILL KEEP A SMALL CHANCE OF POPS IN FOR A SATURDAY AFTERNOON FROPA WITH THIS. ANOTHER WEAK HIGH PRESSURE AREA WILL MOVE INTO THE STATE FOR THE START OF THE NEW WORK WEEK...THOUGH THE NEXT FRONT MAY SNEAK INTO THE NORTHERN EXTENT OF THE CWA ON TUESDAY IN ASSOCIATION WITH THE RESURGENCE OF THE BROAD MID LEVEL TROUGH. THE CR GRID LOAD CAME IN DECENT ENOUGH GIVEN THE COMPROMISE PREFERRED ABOVE WITH LITTLE POP OR SKY ADJUSTMENTS NEEDED. AGAIN WENT WITH SOME SMALL RIDGE AND VALLEY ADJUSTMENTS TO LOW TEMPS FOR THURSDAY AND FRIDAY NIGHTS AS WELL AS SUNDAY AND MONDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 238 PM EDT WED OCT 16 2013 A COLD FRONT...WILL CONTINUE TO SLOWLY TREK EASTWARD INTO EASTERN KY EARLY IN THE PERIOD. AHEAD OF THIS BOUNDARY IN SHOWERS AND DRIZZLE...CIGS HAVE DROPPED TO MVFR OR LOWER WITH IFR AND AT TIMES LOWER CIGS RECENTLY REPORTED WEST OF AN SJS TO CPF TO IOB LINE. THIS INCLUDES ALL OF THE TAF SITES. THE FRONT WILL THEN STALL OVER EASTERN KY OVERNIGHT AND PIVOT SOUTHWARD SLIGHTLY. THIS WILL LEAD TO CONTINUED CHANCES FOR RAIN ACROSS THE TAF SITES THROUGH THE NIGHT AND INTO TOMORROW MORNING. BETWEEN 2Z AND 9Z A RELATIVE LULL IN PRECIP CHANCES IS EXPECTED WITH ANY IMPROVEMENT OF CIGS INTO THE VFR RANGE SHORT LIVED AS THE NEXT WAVE SHOULD BRING ANOTHER ROUND OF SHOWERS AND CIGS TO IFR OR EVEN TO AIRPORT MINS LATE IN THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...JMW LONG TERM...GREIF AVIATION...JP
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1222 PM CDT WED OCT 16 2013 .UPDATE... ISSUED AT 900 AM CDT WED OCT 16 2013 OUR MORNING LOW TEMPERATURES HAVE ALREADY BEEN REACHED AND TEMPERATURES ARE NOW RISING. THEREFORE...THE FROST AND FREEZE HEADLINES HAVE BEEN ALLOWED TO EXPIRE FOR ALL AREAS. TEMPERATURES WILL AGAIN BE VERY CHILLY TONIGHT AND FROST MAY AGAIN BE POSSIBLE IN SOME AREAS BY EARLY THURSDAY MORNING. UPDATE ISSUED AT 646 AM CDT WED OCT 16 2013 LITTLE CHANGE IN THINKING FROM A FEW HOURS AGO...AS ONE DECK OF MID CLOUDS CONTINUES SINKING SOUTHWARD ACROSS THE NORTHERN CWA...WHILE MAINLY THINNER/HIGHER CIRRUS CONTINUES INCREASING INTO AREAS NEAR/SOUTH OF THE STATE LINE. IN BETWEEN...MOST PLACES BETWEEN I-80 AND THE STATE LINE ARE ESSENTIALLY CLEAR AT THIS TIME. ALTHOUGH LIGHT BUT STEADY BREEZES HAVE LIKELY PRECLUDED TRULY WIDESPREAD FROST DEVELOPMENT IN MANY AREAS...PRESENT INDICATIONS ARE THAT THE FROST/FREEZE HEADLINES ISSUED YESTERDAY WERE JUSTIFIED ACROSS MOST AFFECTED AREAS...WITH A FEW LOWS SO FAR THIS MORNING CONSISTING OF 31 AT LEXINGTON AIRPORT...32 AT RAVENNA...HOLDREGE AIRPORT AND 4WNW PLAINVILLE KS...AND 33 AT HASTINGS AIRPORT. WITH CLOUDS ON THE INCREASE...ITS BECOMING INCREASINGLY UNLIKELY THAT FROST WILL BE OBSERVED IN THE HAMILTON/YORK AND JEWELL/MITCHELL COUNTY AREAS...BUT GIVEN THAT TEMPS ARE AT LEAST IN THE BALLPARK OF SUPPORTING FROST AT THIS TIME WILL DEFER TO ONCOMING DAY SHIFT TO FORMALLY PUT THESE HEADLINES TO REST. ONCE ALL MORNING TEMPERATURE REPORTS COME IN...DECISIONS WILL ALSO BE MADE REGARDING WHICH ADDITIONAL COUNTIES BESIDES VALLEY/GREELEY ARE DEEMED INELIGIBLE FOR FUTURE FROST/FREEZE HEADLINES...AS WE WILL LIKELY BE ADDING AT LEAST A FEW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 430 AM CDT WED OCT 16 2013 COMPARED TO THE PAST 48 HOURS OF WIDESPREAD RAIN FOLLOWED BY FAIRLY STRONG NORTHWEST WINDS...THESE NEXT 24 HOURS ARE GOING TO BE A BENIGN CHANGE OF PACE...WITH ESSENTIALLY ZERO RISK OF MEASURABLE PRECIP AND SUSTAINED BREEZES STRUGGLING TO EXCEED 12 MPH AT MOST. HOWEVER...DUE TO FROST/FREEZE SENSITIVITIES THIS TIME OF YEAR...SKY COVER/CLOUD TRENDS HAVE TAKEN ON AN ENHANCED FORECAST FOCUS...GIVEN THE PRONOUNCED EFFECT OF CLOUD COVER ON TEMPERATURES. AS IT IS TURNING OUT...PARTS OF THE CWA ARE GOING TO FREEZE AND/OR FROST FAIRLY EFFICIENTLY THIS MORNING...WHILE OTHER PARTS OF THE AREA MAY ACTUALLY SEE MORE FAVORABLE CONDITIONS FOR FROST/FREEZE WEDNESDAY NIGHT INSTEAD. 07Z OBJECTIVE SURFACE ANALYSIS SHOWS THE LOCAL AREA POSITIONED BETWEEN A 1003 MILLIBAR LOW THAT HAS DEPARTED WELL EASTWARD INTO THE GREAT LAKES...AND A 1025 MILLIBAR HIGH CENTERED MUCH CLOSER TO HOME OVER THE NEB/KS/CO BORDER AREA. WITH THE PRESSURE GRADIENT CONTINUING TO RELAX...WEST-NORTHWEST BREEZES ACROSS MOST OF THIS CWA HAVE FINALLY EASED TO 10 MPH OR LESS...BUT WITH SLIGHTLY STRONGER SPEEDS STILL SHOWING UP NOW AND THEN MAINLY IN THE NORTHEAST. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL THAT THE CWA IS POSITIONED ALMOST DIRECTLY UNDERNEATH A BROAD...SEVERELY POSITIVELY TILTED MID/UPPER LEVEL TROUGH AXIS EXTENDING IN A SOUTHWEST-NORTHEAST ORIENTATION FROM THE 4-CORNERS AREA THROUGH THE GREAT LAKES AND UP INTO EASTERN CANADA. ALONG THE SOUTHERN EDGE OF THIS TROUGH AXIS...A 105+ KT JET STREAK IS EVIDENT AT 300MB OVER THE KS/NEB BORDER. THE FOLLOWING PARAGRAPH FOCUSES SOLELY ON EXISTING FROST/FREEZE HEADLINES THIS MORNING...THE REAL HEADACHE THIS MORNING LIES WITH CLOUD COVER TRENDS PER IR AND 11-3.9 MICRON SATELLITE. ON A POSITIVE NOTE FOR CURRENT FROST/FREEZE HEADLINES...THE EXPANSIVE DECK OF LOW STRATUS THAT RULED MOST OF THE CWA ON TUESDAY CONTINUES TO STEADILY ERODE FROM NORTHWEST-TO-SOUTHEAST...WHICH MAKES IT NOW LOOK LIKE MUCH OF THE CWA SHOULD SEE AT LEAST A FEW HOURS OF CLEAR SKIES...POTENTIALLY ALLOWING FROST FORMATION TO COMMENCE. IN FACT...THIS PROCESS IS LIKELY ALREADY WELL-UNDERWAY IN/NEAR FAR WESTERN PORTIONS OF THE CWA...WHERE SITES SUCH AS LEXINGTON/MCCOOK HAVE ALREADY TUMBLED INTO THE LOW 30S THUS VERIFYING THE EXISTING FREEZE WARNING. HOWEVER...ON THE FLIP SIDE...PORTIONS OF THE ORIGINAL FROST ADVISORY ACROSS ROUGHLY THE EASTERN HALF OF THE CWA SEEMS TO BE FACING A GREATER OBSTACLE TO VERIFY...AS FOLLOWING SHORTLY BEHIND THE VACATING LOW STRATUS IS A SOUTHWARD-SINKING BAND OF MID LEVEL CLOUDS CENTERED BETWEEN 8-10K FEET...WHICH HAS ALREADY BRUSHED INTO THE FAR NORTHERN CWA...AND IS EXPECTED TO SLOWLY DROP SOUTHWARD TO AT LEAST ROUGHLY THE HIGHWAY 6 CORRIDOR BY SUNRISE. HOWEVER...THESE MID CLOUDS SHOULD HAVE LITTLE EFFECT ON EARLY MORNING TEMPERATURES ACROSS MOST OF THE SOUTHERN HALF TO ONE-THIRD OF THE CWA...WITH THESE AREAS LIKELY HEADED FOR SEVERAL HOURS OF CLEARING IN THE WAKE OF THE DEPARTING LOWER DECK. THE NET RESULT...AS IT CURRENTLY STANDS AT 09Z/4AM...IS THAT ADVISORIES/WARNINGS WERE CANCELLED FOR 5 COUNTIES NORTH OF INTERSTATE 80...WHILE AT LEAST FOR NOW WILL LET THE REMAINING 23 COUNTIES STAND AS-IS PER ORIGINAL ISSUANCE...AND TAKE ANOTHER LOOK FOR POSSIBLE UPDATES IN A FEW HOURS. TURNING TO OTHER ELEMENTS OF THE FORECAST...RIGHT OFF THE BAT DECIDED TO SLIP A SLIGHT CHANCE OF SPRINKLES INTO FAR NORTHERN AREAS UP AROUND ORD/GREELEY PRIOR TO SUNRISE TO ACCOUNT FOR A FEW WEAK RETURNS SHOWING UP ON RADAR UNDER THE INVADING MID-DECK...BUT THIS SHOULD BE VERY ISOLATED IN NATURE. BEYOND SUNRISE...ANTICIPATE A COOLISH BUT SEASONABLY PLEASANT DAY UNDER VARIABLE CLOUD COVER. ALOFT...THE AFOREMENTIONED ELONGATED MID LEVEL TROUGH AXIS WILL CONTINUE SLIPPING SOUTHWARD ACROSS THE REGION...AS A SHORTWAVE CURRENTLY WITHIN THE BASE OF THE TROUGH NEAR THE 4-CORNERS AREA GRADUALLY EJECTS EASTWARD ALONG THE KS/OK BORDER AS THE DAY WEARS ON. WHILE ANY SPOTTY RAIN FROM THIS DISTURBANCE SHOULD REMAIN WELL SOUTH OF THE LOCAL AREA...ESPECIALLY OUR KS ZONES COULD SEE A FAIR AMOUNT OF MID/UPPER LEVEL CLOUDS STREAMING EAST-NORTHEAST FROM THIS SYSTEM. MEANWHILE...THE ALREADY-PRESENT MID DECK SLIPPING INTO NORTHERN COUNTIES WILL CONTINUE TO SLOWLY SINK SOUTHWARD...AND IS EXPECTED TO PROVIDE A CLOUDY START TO THE DAY ACROSS THE MAJORITY OF NEB ZONES...BUT THEN ACCORDING TO 700 MILLIBAR RELATIVE HUMIDITY PROGS FROM THE RAP/NAM...SHOULD GRADUALLY FADE AWAY OR SCATTER OUT BY THE MID-LATE MORNING HOURS. SO...THE NET RESULT IS BEST PUT AS VARIABLE CLOUD COVER...AS NORTHERN AREAS SHOULD GENERALLY START OUT RATHER CLOUDY BUT SEE INCREASING SUN WITH TIME...WHILE SOUTHERN AREAS GENERALLY DO THE OPPOSITE AND SEE INCREASING CLOUDS WITH TIME. THESE CLOUD COVER TRENDS WILL BE TOUGH TO CAPTURE IN HOURLY FORECAST GRIDS...AND PLENTY OF UPDATES ARE LIKELY. OTHERWISE...AS THE CENTER OF THE SURFACE RIDGE AXIS SINKS SOUTH OF THE AREA TODAY...BREEZES WILL AVERAGE 10-12 MPH FROM THE WEST-NORTHWEST IN ALL AREAS. HIGH TEMPERATURES WERE ONLY TWEAKED SLIGHTLY PER A BLEND OF MET/MAV GUIDANCE AND RAP TEMPS...AND THUS WILL CONTINUE TO CALL FOR A REMARKABLY UNIFORM RANGE ACROSS THE CWA WITH ALL AREAS TOPPING OUT BETWEEN 56-59. FOR THIS EVENING/TONIGHT...THE MAIN STORY ALOFT IS THAT THE CURRENT SOUTHWEST-TO-NORTHEAST TROUGH AXIS WILL GRADUALLY BE REPLACED BY A SOUTHWEST-NORTHEAST ORIENTED SHORTWAVE RIDGE AXIS. THIS IS BECAUSE THE LOCAL AREA WILL BE IN BETWEEN TROUGHS...AS THE DISTURBANCE CENTERED OVER SOUTHERN KS AT SUNSET DEPARTS EASTWARD INTO MO...WHILE THE NEXT UPSTREAM TROUGH DROPPING SOUTHEAST TOWARD THE AREA ONLY REACHES AN AXIS FROM NORTHWEST CO TO NORTH DAKOTA BY SUNRISE THURSDAY. ALTHOUGH AM EXPECTING SKIES WEDNESDAY NIGHT AS A WHOLE TO AVERAGE CLEARER THAN THIS ONGOING NIGHT HAS BEEN...THERE IS AGAIN GOING TO BE VARIABLE CLOUD COVER EXCEPT THIS TIME SOLELY OF THE MID-UPPER VARIETY. FOR ONE...MAINLY SOUTHERN PARTS OF THE CWA WILL LIKELY START THE EVENING WITH LINGERING CLOUDS FROM THE DEPARTING DISTURBANCE...WHILE LATER IN THE NIGHT...MAINLY NORTHERN AREAS COULD SEE PASSING BATCHES OF CLOUDS OUT AHEAD OF THE APPROACHING UPSTREAM WAVE. MEANWHILE AT THE SURFACE...WINDS WILL REMAIN FAIRLY LIGHT AT SUSTAINED SPEEDS GENERALLY LESS THAN 8 MPH...BUT GRADUALLY TRANSITION FROM A SOUTHWESTERLY DIRECTION TO NORTHWESTERLY IN RESPONSE TO A SUBTLE PASSING TROUGH AXIS. AS FOR LOW TEMPS...ONCE AGAIN PASSING CLOUDS COULD POSE ISSUES...BUT FOR NOW STUCK VERY CLOSE TO A MET/MAV GUIDANCE BLEND...WHICH PUTS THE MAJORITY OF THE CWA DOWN BETWEEN 33-36 DEGREES...WITH THE TYPICALLY FAVORED DAWSON-TO-VALLEY COUNTY CORRIDOR MOST FAVORED TO SLIP SLIGHTLY BELOW FREEZING. OBVIOUSLY THESE LOWS ARE AGAIN SUPPORTIVE OF FROST AND/OR FREEZE DEVELOPMENT. HOWEVER...GIVEN THE ONGOING COMPLICATIONS/UNCERTAINTY THIS MORNING REGARDING LOW TEMPS...WILL HOLD OFF ON ANY WEDNESDAY NIGHT FROST ADVISORIES/FREEZE WARNINGS FOR NOW...NOT ONLY TO AVOID HEADLINE CONFUSION...BUT ALSO TO ALLOW DAY SHIFT TO IDENTIFY COUNTIES THAT COULD NOW BE RULED INELIGIBLE FROM FUTURE FROST/FREEZE HEADLINES BASED ON WHAT HAPPENS THIS MORNING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 430 AM CDT WED OCT 16 2013 MAIN CONCERNS THIS FORECAST PERIOD LOOKS TO BE PRECIPITATION CHANCES ON FRIDAY. STARTING OUT THURSDAY MORNING WITH THE BIG PICTURE...THERE SHOULD BE A HIGH AMPLITUDE RIDGE JUST OFF THE PACIFIC U.S. AND CANADIAN COAST WITH A LONG WAVE TROUGH AND SEVERAL EMBEDDED SHORT WAVES SITUATED OVER MUCH OF THE CONUS. THIS PATTERN WILL GRADUALLY SHIFT EAST A BIT BUT THE CENTRAL PLAINS SHOULD STILL BE SITTING ON THE BACK SIDE OF THE UPPER TROUGH BY NEXT TUESDAY...PUTTING US IN NORTHWEST FLOW. AT THE SURFACE ON TUESDAY MORNING...A TROUGH OF LOW PRESSURE EXTENDING FROM LAKE SUPERIOR TO THE OKLAHOMA PANHANDLE SHOULD BE JUST ABOUT THROUGH THE CWA WITH A WIND SHIFT FROM SOUTHWEST TO NORTHWEST. THE COOLER AIR WILL LAG BEHIND THE TROUGH A WAYS AND THURSDAY SHOULD BE QUITE NICE...JUST A FEW DEGREES LOWER THAN SEASONAL NORMALS. THE NEXT IN THE PROGRESSION OF MID LEVEL SHORTWAVES NOTED ABOVE IS THEN SLATED TO APPROACH THE PLAINS FROM THE NORTHWEST THURSDAY NIGHT INTO FRIDAY. SEVERAL MODELS SHOW A SIMILAR SOLUTION IN TAKING ONE WAVE NORTH AND EAST OF US AND DIGGING ANOTHER WAVE TO OUR WEST AND THEN SOUTH ACROSS KANSAS. INTERESTING TO RUN A TIME HEIGHT SECTION COMPARING THE GRAND ISLAND AREA TO THE PHILLIPSBURG KANSAS AREA IN TERMS OF MID LEVEL FORCING. THE NAM IS ONLY PRODUCING 1-2 UBARS PER SEC OF OMEGA OVER KGRI AT 12Z FRIDAY WHILE AT KPHG IT IS GENERATING 10-12 UBARS PER SEC. THE GFS HAS SIMILAR RESULTS FOR OUR SOUTHERN CWA WITH THE ONLY DIFFERENCE BEING THE GFS HAS A LITTLE LESS LOW LEVEL MOISTURE TO WORK WITH AND MAY TAKE A WHILE TO SATURATE THE COLUMN...WHILE THE NAM IS SATURATED ALL THE WAY FROM NEAR THE SURFACE TO 300 MB. THE EC FORECAST SOUNDING IS SIMILAR TO THE GFS AS IT IS NOT QUITE SATURATED UP TO 700MB. NEITHER THE GFS OR EC IS SHOWING THE LOWER PORTION BECOMING SATURATED BETWEEN 12 AND 18Z FRIDAY BUT I AM A LITTLE CONCERNED OF THE SCENARIO WHERE SNOW FALLING FROM ABOVE MOISTENS AND COOLS THE LOWER COLUMN UNTIL IT REACHES SATURATION. IF THIS WERE TO OCCUR...WE COULD SEE A LITTLE SNOW FRIDAY MORNING IN THE CWA. WILL NOT INCLUDE SNOW IN THE GRIDS FOR NOW AS I ONLY HAVE LOW TEMPERATURES FRIDAY MORNING FORECASTED TO BE AROUND 37 OR 38 DEGREES IN THE KANSAS PART OF OUR CWA...BUT IT WILL BE WORTH KEEPING AN EYE ON THE NEXT COUPLE OF DAYS. BUMPED UP POPS IN THE SOUTHERN PART OF THE CWA FOR FRIDAY AND THESE WILL NEED TO BE RAISED EVEN MORE IF THE MODELS REMAIN CONSISTENT ON THE TRACK OF THE SHORT WAVE TROUGH. THE COOLER AIR WILL THEN MAKE IT INTO THE AREA THURSDAY NIGHT AND BY FRIDAY HIGHS SHOULD BE 5 TO 10 DEGREES COOLER THAN ON THURSDAY. BUT THE COOLER WEATHER WILL ONLY LAST A DAY AS SATURDAY THROUGH TUESDAY SHOULD AGAIN BE IN THE UPPER 50S NORTH TO THE MID 60S SOUTH. WILL LEAVE REST OF FORECAST DRY FOR NOW BUT NOT TOTALLY OUT OF THE QUESTION THAT ONE OR TWO DISTURBANCES RIDING DOWN THE NORTHWEST FLOW MAY GIVE US AT LEAST A SLIGHT CHANCE FOR ADDITIONAL PRECIPITATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1223 PM CDT WED OCT 16 2013 SATELLITE SHOWS THAT THE BAND OF CLOUDS OVER THE KGRI TERMINAL AREA HAS BEEN THINNING OUT LATE THIS MORNING AND EARLY THIS AFTERNOON. EXPECT THERE TO BE SOME SCATTERED MID LEVEL CLOUDS ON AND OFF DURING THE NIGHT WITH AN INCREASE IN MID LEVEL CLOUDS LATE IN THE PERIOD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...WESELY SHORT TERM...PFANNKUCH LONG TERM...EWALD AVIATION...JCB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
305 PM CDT WED OCT 16 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 305 PM CDT WED OCT 16 2013 MAIN FORECAST CHALLENGE THROUGH THE SHORT TERM WILL BE THE PERIODIC CHANCES FOR LIGHT RAIN POSSIBLY MIXED WITH A LITTLE WHITE STUFF. MODELS HAVE A DECENT HANDLE ON THINGS WHICH MATCHES UP WELL WITH FORECAST CONTINUITY. AS OF LATE AFTERNOON CLOUDS WERE SLOWLY STARTING TO INCREASE ACROSS THE NORTHWEST PART OF ND BUT NOT SO MUCH YET INTO THIS FA. TEMPS HAVE RISEN NICELY WITH THE WEST/SW WINDS CURRENTLY BEING REPORTED. THE COLD FRONT AND NORTHWEST WIND SWITCH ARE STARTING TO PUSH INTO NORTHWEST SECTIONS OF THE STATE. SO FAR NOT MUCH PCPN BEHIND THE UPSTREAM COLD FRONT AS JUST A FEW STATIONS IN NORTH CENTRAL MT ARE REPORTING LIGHT RAIN. HOWEVER THESE CLOUDS AND THE PATCHY LIGHT RAIN WILL SLOWLY MOVE IN TONIGHT AND MAINLY ALONG AND WEST OF THE RED RIVER VALLEY. TEMPS SHOULD STAY WARM ENOUGH TO KEEP ANY PCPN IN THE LIQUID FORM. FOR THU THE FIRST SHORT WAVE WILL FINISH MOVING THROUGH THE AREA MAINLY AFFECTING THE SOUTHERN HALF OF THE FA. THE NORTHWEST SHOULD SEE SOME CLEARING DURING THE AFTERNOON. MAY BE A BIT OF A BREAK IN THE PCPN THU EVENING BEFORE ANOTHER SHOT MOVES IN LATE. THIS TIME IT MAY BE COLD ENOUGH FOR THE RAIN TO MIX WITH A LITTLE SNOW LATE. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 305 PM CDT WED OCT 16 2 PRETTY SHARP NORTHWEST FLOW GETS ESTABLISHED BY FRI/SAT WITH THE ENDLESS PIECES OF ENERGY CONTINUING TO DROP SOUTHEAST IN IT. KEPT THE CHANCES FOR RAIN POSSIBLY MIXED WITH SNOW AT TIMES THROUGHOUT. SATURDAY NIGHT THROUGH WEDNESDAY...DETERMINISTIC MODELS ARE IN PRETTY GOOD AGREEMENT OVERALL ON A COLD AND FAIRLY WET PATTERN AS VARIOUS SHORTWAVES MOVE THROUGH THE NORTHWESTERLY FLOW ALOFT. THE DIFFERENCES ARE OF COURSE IN THE DETAILS OF THE EXACT TIMING OF THE SHORTWAVES. THINK THAT WITH SFC HIGH PRESSURE BUILDING IN SATURDAY NIGHT SHOULD BE FAIRLY QUIET...BUT THE MODELS ALL BRING IN ANOTHER SHORTWAVE WITH A CHANCE FOR PRECIP ON SUNDAY. AN EVEN STRONGER SHORTWAVE COMING DOWN INTO THE UPPER MIDWEST MONDAY WILL DRAG DOWN EVEN COOLER TEMPS FOR EARLY NEXT WEEK. THE 00Z ECMWF HAD THE HEIGHTS OVER THE REGION STARTING TO RISE AGAIN BY WEDNESDAY...BUT THE NEW 12Z RUN KEEPS THE MAIN TROUGH FURTHER WEST AND THE CWA IN THE COLDER AIR. WITH THE UNCERTAINTY OF THE SHORTWAVE TIMING...KEPT THE 20-30 POPS AS ALLBLEND GAVE US WITH SOME MINOR TWEAKS FOR AESTHETIC REASONS. SOME OF THE PRECIP DURING THE OVERNIGHT AND MORNING HOURS COULD BE SNOW...SO KEPT THE MIXED MENTION IN THE GRIDS. AFTERNOON TEMPS WILL BE WELL BELOW SEASONAL AVERAGES IN THE 40S...ALTHOUGH CLOUDS AT NIGHT WILL PREVENT LOWS FROM GETTING EXTREMELY COLD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1252 PM CDT WED OCT 16 2013 VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST PART OF THE FORECAST PERIOD. WINDS WILL BECOME MORE WESTERLY BY LATE AFTERNOON OR EARLY EVENING ALONG WITH SOME MID LEVEL CLOUDS AS A TROUGH OF LOW PRESSURE MOVES INTO THE AREA. MORE SIGNIFICANT COLD AIR WILL NOT COME DOWN UNTIL LATER TONIGHT...WITH WINDS BECOMING NORTHWESTERLY OVERNIGHT. SOME OF THE MODELS SUCH AS THE HRRR AND THE SHORT RANGE ENSEMBLES SHOW MVFR OR EVEN IFR CIGS WITH THE BOUNDARY. COVERAGE OF THE REDUCED CATEGORIES LOOKS PRETTY SCATTERED HOWEVER. LOWERED CIGS A BIT BUT KEPT THINGS AT VFR EXCEPT FOR AT KDVL WHERE THEY HAVE A BETTER CHANCE OF GETTING BELOW 3000 FT. CONTINUED WITH VCSH...ALTHOUGH WITH LIMITED MOISTURE DO NOT THINK THE SHOWERS WILL BE MUCH MORE THAN SPRINKLES. ANY LOWER CIGS WILL DISSIPATE AFTER 16Z OR SO. && .HYDROLOGY... FLOOD WATCHES REMAIN IN EFFECT FOR THE RED RIVER AT FARGO AND MINNESOTA TRIBUTARIES AT DILWORTH AND SABIN. THESE POINTS ARE CURRENTLY EXHIBITING FLAT OR SLIGHTLY RISING BEHAVIOR AND IT IS UNCERTAIN WHETHER OR NOT ANY OR ALL OF THESE POINTS WILL REACH MINOR FLOOD. THE WATCHES WILL CONTINUE FOR THE TIME BEING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...GODON LONG TERM...GODON/JR AVIATION...JR HYDROLOGY...WJB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1252 PM CDT WED OCT 16 2013 .UPDATE... ISSUED AT 1252 PM CDT WED OCT 16 2013 FORECAST LOOKING ON TRACK AT THIS POINT SO NO UPDATES PLANNED. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 330 AM CDT WED OCT 16 2013 THE MAIN CHALLENGE WILL BE TEMPS AND LOW CHANCES FOR PRECIP. MODELS ARE IN GOOD OVERALL AGREEMENT WITH NO PREFERENCE THIS MORNING. FOR TODAY...EXPECT TEMPS TO WARM INTO THE MID 50S FOR THE ENTIRE REGION WITH PLENTIFUL SUNSHINE AND WESTERLY WINDS DEVELOPING. FOR TONIGHT...A SHORTWAVE AND SOME DEEPER MOISTURE WILL MOVE INTO THE WESTERN AREAS BY 6Z...THEN INTO THE SOUTH THEREAFTER. THERE COULD BE SOME RAIN SHOWERS MAINLY IN THE WEST LATER TONIGHT...BUT MOST AREAS WILL REMAIN DRY. ON THURSDAY...THERE COULD BE A FEW LINGERING SHOWERS IN THE SOUTH/SE...WITH CLEARING SKIES FROM NW TO SE BY AFTERNOON. TEMPS WILL BE COOLER THAN WED...WITH 850MB TEMPS FALLING BELOW 0C. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM CDT WED OCT 16 2013 FOR FRIDAY AND FRIDAY NIGHT...EXPECT COOL/CYCLONIC FLOW WITH CHANCES FOR SHOWERS. EXPECT SOME RAIN SHOWERS MIXING WITH SOME SNOW PERHAPS LATER FRIDAY NIGHT...AS A SECONDARY COLD FRONT DROPS SOUTH FROM CANADA AND SEVERAL SHORTWAVES MOVING THROUGH. FOR SATURDAY-TUESDAY...A RATHER STABLE LONGWAVE PATTERN OVER NORTH AMERICA WILL CONTINUE THROUGH THESE PERIODS...WITH A TROUGH OVER THE CENTRAL AND EASTERN CONUS...AND A SLOWLY PROGRESSING UPPER RIDGE FROM THE EASTERN PACIFIC INTO THE WESTERN CONUS. THIS WILL KEEP THE AREA UNDER NORTHWEST FLOW ALOFT. SEVERAL UPPER LEVEL SHORTWAVE TROUGHS WILL DIVE SOUTHEAST INTO THE NORTHERN PLAINS...BRINGING A FEW OPPORTUNITIES FOR LIGHT RAIN AND PERHAPS LIGHT SNOW DURING COOLER PERIODS...ALTHOUGH MODELS DIFFER ON THE EXACT TIMING AND PLACEMENT OF THE WAVES. TEMPS WILL BE ON THE COOL SIDE GIVEN THIS PATTERN...WITH HIGHS MAINLY IN THE 40S. QUITE A BIT OF CLOUD COVER IS EXPECTED...WHICH WILL LIKELY AFFECT OVERNIGHT LOWS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1252 PM CDT WED OCT 16 2013 VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST PART OF THE FORECAST PERIOD. WINDS WILL BECOME MORE WESTERLY BY LATE AFTERNOON OR EARLY EVENING ALONG WITH SOME MID LEVEL CLOUDS AS A TROUGH OF LOW PRESSURE MOVES INTO THE AREA. MORE SIGNIFICANT COLD AIR WILL NOT COME DOWN UNTIL LATER TONIGHT...WITH WINDS BECOMING NORTHWESTERLY OVERNIGHT. SOME OF THE MODELS SUCH AS THE HRRR AND THE SHORT RANGE ENSEMBLES SHOW MVFR OR EVEN IFR CIGS WITH THE BOUNDARY. COVERAGE OF THE REDUCED CATEGORIES LOOKS PRETTY SCATTERED HOWEVER. LOWERED CIGS A BIT BUT KEPT THINGS AT VFR EXCEPT FOR AT KDVL WHERE THEY HAVE A BETTER CHANCE OF GETTING BELOW 3000 FT. CONTINUED WITH VCSH...ALTHOUGH WITH LIMITED MOISTURE DO NOT THINK THE SHOWERS WILL BE MUCH MORE THAN SPRINKLES. ANY LOWER CIGS WILL DISSIPATE AFTER 16Z OR SO. && .HYDROLOGY... A RIVER FLOOD WARNING CONTINUES ALONG THE RED RIVER AT WAHPETON...WITH RIVER FLOOD WATCHES REMAINING IN EFFECT ALONG THE RED RIVER AT FARGO...S BRANCH BUFFALO RIVER AT SABIN...AND BUFFALO RIVER NEAR DILWORTH. RIVER RISES CONTINUE OVER SECTIONS OF THE RED RIVER AND AREA TRIBUTARIES. RIVER RISES WILL NEED TO BE MONITORED...WITH SOME UNCERTAINTY REGARDING THE DEGREE OF RIVER RISES. BASED ON CURRENT DATA...RISES ARE BEGINNING TO SLOW AT WAHPETON...ALONG THE S BUFFALO RIVER NEAR SABIN...AND ALONG THE WILD RICE RIVER AT ABERCROMBIE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...GODON SHORT TERM...DK LONG TERM...DK/MAKOWSKI AVIATION...JR
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
315 PM CDT WED OCT 16 2013 .DISCUSSION... CURRENTLY...A COLD FRONT STRETCHES FROM EASTERN KENTUCKY THROUGH KCBM INTO LOUISIANA. THE RAIN SHIELD IS PROGRESSING TO THE EAST AND NOW COVERS AREAS GENERALLY SOUTH OF I-40 AND EAST OF I-55. CLOUDS COVER MOST OF THE REST OF THE MIDSOUTH THOUGH THE SUN IS TEMPORARILY PEAKING OUT ACROSS PARTS OF NORTHEAST ARKANSAS. TEMPS ARE WELL BELOW NORMAL AS MUCH COOLER AIR FILTERS IN WITH READINGS HOVERING AROUND 60 WITH A LIGHT NNW WIND. TONIGHT...THE COLD FRONT WILL PUSH SLOWLY EAST. MEANWHILE A WEAK LOW PRESSURE SYSTEM WILL RIDE NORTHEAST ALONG THE FRONT AS A PIECE OF UPPER LEVEL ENERGY NOW MOVING THROUGH THE ARKLATEX PUSHES INTO THE LOWER MISSISSIPPI VALLEY. AS A RESULT THE POST FRONTAL RAIN SHIELD SHOULD EXPAND OVERNIGHT AND PUSH ACROSS NORTH MISSISSIPPI. THE 12Z NAM AND LATEST HRRR DEPICT THIS SCENARIO WHILE THE GFS AND ECMWF ARE LESS BULLISH. WILL ALSO KEEP SMALL POPS ACROSS THE REMAINDER OF THE AREA AS A MID LEVEL SHORTWAVE PUSHES THROUGH THE MID MS VALLEY. THIS FEATURE MAY RESULT IN SOME SPOTTY LIGHT SHOWERS ACROSS THE AREA LATER THIS EVENING AND AFTER MIDNIGHT. GENERALLY WENT ABOVE TEMP GUIDANCE DUE TO CLOUDS. THURSDAY...KEPT A SMALL CHANCE OF RAIN ACROSS EASTERN SECTIONS IN THE MORNING FOLLOWED BY GRADUAL CLEARING AS HIGH PRESSURE BUILDS IN. TEMPS WILL BE A FEW DEGREES COOLER THAN NORMAL...IN THE UPPER 60S TO AROUND 70. THURSDAY NIGHT THROUGH FRIDAY...WEAK HIGH PRESSURE WILL PREVAIL WITH PLEASANT CONDS. MOSTLY CLEAR AND COOL THURSDAY NIGHT WITH LOWS IN THE 40S. EXPECT A SUNNY START TO FRIDAY FOLLOWED BY INCREASING CLOUDS IN THE AFTERNOON WITH THE APPROACH OF THE NEXT SYSTEM. HIGHS WILL BE A COUPLE OF DEGREES WARMER. FRIDAY NIGHT AND SATURDAY...A WEAK REINFORCING COLD FRONT WILL PUSH THROUGH FRIDAY NIGHT WITH THE BEST CHANCE FOR SHOWERS ALONG THE MISSOURI/KY BORDER. MODELS CONTINUE TO TREND TOWARD A DRIER FORECAST ACROSS SOUTHERN AREAS WITH THE LOW PRESSURE ALONG THE GULF REMAINING WELL TO THE SOUTH. WILL LEAVE IN SLIGHT CHANCE POPS ACROSS THE SOUTH FOR NOW BUT THESE MAY NEED TO BE PULLED IF CURRENT TRENDS HOLD. EXPECT SOME CLEARING BY SATURDAY AFTERNOON WITH SEASONABLY COOL TEMPS. SUNDAY THROUGH WEDNESDAY...LOOKS LIKE A PLEASANT STRETCH OF WEATHER WITH HIGH PRESSURE AT THE SURFACE AND COOL WNW FLOW ALOFT. A COUPLE OF WEAK REINFORCING FRONT PUSH THROUGH ON TUESDAY AND AGAIN ON WEDNESDAY BUT THEY ARE MOISTURE STARVED SO REMOVED MENTION OF POPS FOR NOW. TEMPS WILL BE SEASONABLE THEN TURNING COOLER BY MIDWEEK. LONG RANGE MODELS ARE HINTING AT A VERY COOL AIRMASS PUSHING IN BY THU OR FRI OF NEXT WEEK. SJM && .AVIATION... 18Z TAF CYCLE RAIN WILL CONTINUE TO DISSIPATE FROM NORTH TO SOUTH ACROSS THE REGION AS THE FRONT MOVES SOUTHWARD TODAY. CIGS REMAIN MVFR AT NEARLY ALL SITES AS THE POST FRONTAL CLOUDS CONTINUE TO MOVE EAST. RAIN WILL CONTINUE TO AFFECT MKL AND TUP AS ANOTHER UPPER LEVEL WAVE LIFTS THROUGH LATER TODAY. SHOWERS WILL EVENTUALLY TAPER OFF NEAR THE END OF THE PERIOD NEAR TUP. EXPECT MVFR CIGS TO REMAIN AT ALL SITES THROUGH MOST OF THE PERIOD...EXCEPT FOR JBR WHERE CIGS WILL BECOME VFR BY 21Z. SOME OVERNIGHT FOG WILL KEEP MVFR CONDS AT MEM...MKL...AND TUP...BEFORE CLEARING OUT AROUND SUNRISE TOMORROW...THEREAFTER VFR CONDS TO PREVAIL. WINDS WILL REMAIN FROM THE NORTH AT 3-7 KTS. AC3 && .PRELIMINARY POINT TEMPS/POPS... MEM 55 69 49 73 / 30 10 10 10 MKL 53 67 40 70 / 30 20 10 10 JBR 51 68 43 72 / 20 10 10 10 TUP 57 70 47 72 / 70 20 10 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
113 PM CDT WED OCT 16 2013 .UPDATE... UPDATED FOR 18Z AVIATION DISCUSSION. && .DISCUSSION... A COLD FRONT STRETCHES FROM CENTRAL KENTUCKY THROUGH TUPELO INTO THE LOUISIANA. POST FRONTAL RAIN COVERS A GOOD POSITION OF THE MIDSOUTH INCLUDING MOST OF WEST TENNESSEE...NORTH MISSISSIPPI AND EAST CENTRAL ARKANSAS. RAIN HAS ENDED ACROSS MOST OF NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL. MUCH COOLER AIR IS MOVING IN BEHIND THE FRONT WITH TEMPS IN THE MID AND UPPER 50S BEHIND THE FRONT. STILL MILD AHEAD OF THE FRONT WITH TEMPS IN THE MID AND UPPER 60S ACROSS NORTHEAST MISSISSIPPI. GIVEN THE AREAL COVERAGE ATTM AND THE LATEST HRRR HAVE UPPED POPS ACROSS MUCH THE SE HALF OF THE FORECAST AREA FOR THIS AFTERNOON. SJM && A COLD FRONT CURRENTLY STRETCHES FROM NEAR EVANSVILLE INDIANA TO PINE BLUFF ARKANSAS. A LARGE SHIELD OF RAIN IS PUSHING NORTHEAST ALONG THE FRONT. THE NORTHERN EDGE OF THE RAIN IS FURTHER NORTH THAN WHAT THE GFS AND NAM INITIALIZED WITH THUS FOR THIS MORNINGS FORECAST HAVE LEANED TOWARD THE LATEST HRRR RUN. THUS EXPECT RAIN TO CONTINUE TO FALL OVER AT LEAST THE NORTHWEST HALF OF THE CWA...MAINLY NORTHWEST OF A LINE FROM CLARKSDALE MISSISSIPPI TO JACKSON TENNESSEE THROUGH 10 AM. THEREAFTER...EXPECT RAIN TO GRADUALLY SHIFT SOUTHEAST AS THE DAY PROGRESSES. RAIN AND CLOUDS WILL KEEP TEMPERATURES COOL WITH A LOT OF LOCATIONS HAVING TEMPERATURES HOLD STEADY THROUGHOUT THE DAY FROM WHAT THEIR MORNING LOWS ARE. TONIGHT...EXPECT FRONT TO BE LOCATED ACROSS NORTHEAST MISSISSIPPI. MODELS INDICATING ANOTHER WEAK LOW PRESSURE CENTER DEVELOPING ALONG THE FRONT AS A SHORTWAVE MOVES INTO NORTHEAST ARKANSAS THIS EVENING. RAIN WILL SPREAD BACK NORTHWARD. ALTHOUGH A LOT OF THE PRECIPITATION WILL FALL AS VERY LIGHT RAIN OR POSSIBLY DRIZZLE SO EXPECT RAINFALL AMOUNTS TO BE ON THE LIGHT SIDE. LOWS WILL BE IN THE UPPER 40S TO UPPER 50S. THURSDAY...SHORTWAVE WILL FINALLY PUSH THE FRONT EAST OF THE AREA. EXPECT LIGHT RAIN/DRIZZLE AND CLOUDS TO REMAIN AROUND AT LEAST EASTERN PORTIONS OF THE MIDSOUTH IN THE MORNING. CONDITIONS WILL QUICKLY IMPROVE DURING THE AFTERNOON HOURS WITH A LOT OF LOCATIONS SEEING SUNSHINE BY THE END OF THE DAY. EXPECT HIGHS IN THE MID TO UPPER 60S. THURSDAY NIGHT INTO FRIDAY...SFC HIGH PRESSURE WILL BUILD OVER THE MIDSOUTH. MOSTLY CLEAR SKIES AND LIGHT WINDS WILL ALLOW LOWS TO DROP DOWN INTO THE 40S ACROSS THE ENTIRE CWA. WOULD NOT BE SURPRISED TO SEE A FEW UPPER 30 READINGS ALONG THE TENNESSEE RIVER. FRIDAY NIGHT INTO SATURDAY...MODELS ARE TRENDING TOWARD A DRIER FORECAST DURING THIS TIME FRAME. LOOKS LIKE THE LOW PRESSURE SYSTEM THAT DEVELOPS ALONG THE GULF COAST WILL BE FAR ENOUGH SOUTH TO KEEP RAIN FROM SPREADING BACK INTO THE AREA. CAN/T RULE OUT THE NORTHERN EDGE OF RAIN SKIRTING AREAS IN TALLAHATCHIE TO MONROE COUNTIES IN MISSISSIPPI ON SATURDAY THUS HAVE LEFT SMALL POPS. IN ADDITION...THERE WILL BE A REINFORCING COLD FRONT THAT MOVES INTO THE AREA LATE FRIDAY NIGHT INTO SATURDAY FROM THE NORTH. GFS SHOWS THE FRONT MOVING THROUGH DRY WHILE THE ECMWF SHOWS VERY LIGHT QPF OVER THE AREA. FOR NOW HAVE JUST KEPT 20 POPS ACROSS THE ENTIRE CWA BUT WOULD NOT BE SURPRISED IF THE DAY SHIFT WILL BE ABLE TO REMOVE CHANCES. HIGH PRESSURE WILL SETTLE BACK OVER THE CWA FOR THE LATTER PART OF THE WEEKEND INTO EARLY NEXT WEEK. EXPECT SUNDAY NIGHT TO BE ANOTHER CHILLY NIGHT WITH SEVERAL LOCATIONS ACROSS WEST TENNESSEE AND POSSIBLY NORTHEAST MISSISSIPPI GETTING DOWN INTO THE UPPER 30S. ANOTHER COLD FRONT OR LOW PRESSURE SYSTEM MAY AFFECT THE MIDSOUTH MONDAY NIGHT INTO TUESDAY. GFS AND ECMWF HAVE DIFFERENT SOLUTIONS WITH THE ECMWF BEING DRIER. FOR NOW HAVE ADDED 20 POPS FOR TUESDAY. KRM && .AVIATION... 18Z TAF CYCLE RAIN WILL CONTINUE TO DISSIPATE FROM NORTH TO SOUTH ACROSS THE REGION AS THE FRONT MOVES SOUTHWARD TODAY. CIGS REMAIN MVFR AT NEARLY ALL SITES AS THE POST FRONTAL CLOUDS CONTINUE TO MOVE EAST. RAIN WILL CONTINUE TO AFFECT MKL AND TUP AS ANOTHER UPPER LEVEL WAVE LIFTS THROUGH LATER TODAY. SHOWERS WILL EVENTUALLY TAPER OFF NEAR THE END OF THE PERIOD NEAR TUP. EXPECT MVFR CIGS TO REMAIN AT ALL SITES THROUGH MOST OF THE PERIOD...EXCEPT FOR JBR WHERE CIGS WILL BECOME VFR BY 21Z. SOME OVERNIGHT FOG WILL KEEP MVFR CONDS AT MEM...MKL...AND TUP...BEFORE CLEARING OUT AROUND SUNRISE TOMORROW...THENAFTER VFR CONDS TO PREVAIL. WINDS WILL REMAIN FROM THE NORTH AT 3-7 KTS. AC3 && .PRELIMINARY POINT TEMPS/POPS... MEM 63 55 69 47 / 80 30 20 10 MKL 62 54 66 40 / 90 30 20 10 JBR 65 49 67 42 / 30 20 10 10 TUP 69 57 67 47 / 90 50 30 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
233 PM CDT WED OCT 16 2013 .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) ISSUED AT 233 PM CDT WED OCT 16 2013 MAIN FORECAST CHALLENGES THROUGH THE SHORT TERM WILL BE... 1. CLOUD TRENDS OVERNIGHT AND IMPACT ON FOG/FROST FORMATION...AND 2. RAIN CHANCES FROM LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. WATER VAPOR IMAGERY COUPLED WITH RAP 500MB ANALYSIS SHOWS AN ELONGATED TROUGH EXTENDING FROM EASTERN ONTARIO CANADA...THROUGH WI/IA/NEB AND CO. STRATUS IS HOLDING STUBBORNLY ACROSS THE AREA AS A RESULT OF THE GENERAL CYCLONIC FLOW ALOFT. TEMPERATURES WERE ALSO SUFFERING AS A RESULT OF THE TROUGH AND CLOUDS...CURRENTLY SITTING IN THE 40S FOR THE MOST PART. FOR TONIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL DRIFT ACROSS THE AREA. AS A RESULT...MODEL CONSENSUS SHOWS FAIRLY GOOD CLEARING/THINNING OF THE STRATUS DECK FROM NORTHWEST TO SOUTHEAST THIS EVENING WITH MOSTLY CLEAR CONDITIONS EXPECTED BY MIDNIGHT. THIS WILL SET UP GOOD RADIATIONAL COOLING...AND WITH A RELATIVELY MOIST LOWER BOUNDARY LAYER...PATCHY FOG IS LIKELY. IN ADDITION... TEMPERATURES ARE EXPECTED TO DIVE INTO THE UPPER 20S/LOWER 30S ALONG AND NORTH OF THE I-94 CORRIDOR FOR AREAS/WIDESPREAD FROST. ELSEWHERE...LOWS TONIGHT ARE EXPECTED TO BE IN THE MID-UPPER 30S...SO CANNOT RULE OUT SOME POCKETS OF FROST. HOWEVER... HEADLINE-ABLE FROST IS NOT EXPECTED. WILL THEN BE WATCHING A MID-LEVEL TROUGH AND SURFACE COLD FRONT DROP SOUTHEAST ACROSS THE AREA LATER THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. NAM/GFS SHOWING FAIRLY DECENT PV-ADVECTION IN THE 700-300MB LAYER ASSOCIATED WITH THIS WAVE FOR A BOUT OF SCATTERED RAIN SHOWER ACTIVITY MOVING INTO AND ACROSS THE AREA. WARM AIR ADVECTION AHEAD OF THE MID-LEVEL WAVE/SURFACE COLD FRONT THURSDAY BRING 925MB TEMPERATURES INTO THE 8-11C RANGE. THIS SHOULD EQUATE TO NEAR SEASONABLE HIGHS IN THE MIDDLE 50S TO AROUND 60 DEGREES. LOWS THURSDAY NIGHT BEHIND THE COLD FRONT ARE EXPECTED TO DROP INTO THE UPPER 30S TO LOWER 40S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 233 PM CDT WED OCT 16 2013 MAIN CONCERN THROUGH THE LONG TERM IS UNSEASONABLY COLD UPPER LEVEL CYCLONIC FLOW AND PERIODIC SHOTS AT PRECIPITATION. FRIDAY APPEARS TO BE A DRY DAY AS A WEAK MID-LEVEL/SURFACE RIDGE DRIFTS ACROSS THE AREA. HOWEVER...TEMPERATURES WILL BE SOME 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS IN THE 50-55 DEGREE RANGE. FOR SATURDAY...MODELS IN AGREEMENT IN PUSHING ANOTHER DEEP/COLD MID-LEVEL TROUGH OVER THE REGION FOR UNSEASONABLY COOL TEMPERATURES ALONG WITH SCATTERED RAIN SHOWER ACTIVITY GIVEN STEEP 925-700MB LAPSE RATES. LOOK FOR HIGHS IN THE MIDDLE 40S TO THE LOWER 50S. SATURDAY NIGHT INTO SUNDAY LOOKS DRY AT THIS POINT AS ANOTHER WEAK RIDGE OF HIGH PRESSURE DRIFTS OVER THE REGION. PLAN ON LOWS SATURDAY NIGHT IN THE 29-33 DEGREE RANGE WITH HIGHS SUNDAY IN THE MIDDLE 40S TO NEAR THE 50 DEGREE MARK. MODELS THEN DIVERGE A BIT FOR MONDAY THROUGH WEDNESDAY IN HANDLING OF SYSTEMS RIPPLING ACROSS THE AREA IN COLD NORTHWEST FLOW ALOFT. MODEL CONSENSUS GENERALLY YIELDS A 25-35 PERCENT PROBABILITY OF PRECIPITATION THROUGH THE PERIOD. WILL HAVE TO WATCH PRECIPITATION TYPE SUNDAY NIGHT INTO EARLY MONDAY MORNING / MONDAY NIGHT INTO TUESDAY MORNING / AND TUESDAY NIGHT INTO WEDNESDAY MORNING AS TEMPERATURES WILL BE COLD ENOUGH TO SUPPORT AT LEAST A RAIN/SNOW MIX. OTHERWISE...WITH DAYTIME 925MB TEMPERATURES HOVERING IN THE -1 TO -2C RANGE...DAYTIME HIGHS ARE EXPECT TO BE SOME 10-15 DEGREES BELOW NORMAL WITH READINGS IN THE MID 40S TO NEAR 50 MONDAY AND TUESDAY AND IN THE LOWER AND MIDDLE 40S ON WEDNESDAY. OVERNIGHT LOWS ARE EXPECTED TO BE IN THE LOW-MID 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1228 PM CDT WED OCT 16 2013 TWO CONCERNS FOR THE AVIATION FORECAST...LINGERING STRATUS AND POTENTIAL FOR FOG TONIGHT...ESPECIALLY AT LSE. STRATUS PERSISTS ACROSS MUCH OF WI...SOUTHEAST MN AND NORTHEAST IA...LINGERING IN THE WAKE OF A TROUGH OF LOW PRESSURE THAT MOVED THROUGH THE TAF SITES LAST NIGHT. THE CLEARING LINE IS JUST APPROACHING MSP AT 17Z...CO-LOCATED JUST EAST OF A SURFACE HIGH PRESSURE RIDGE AXIS. AS THIS RIDGE PUSHES EAST...EXPECTING THE CLEARING TO GO ALONG WITH IT. TIMING THIS CLEARING REMAINS PROBLEMATIC...THOUGH...WITH MODEL GUIDANCE CONTINUING TO DELAY THE CLEARING. THIS MAKES SENSE SO HAVE CLEARING GO THROUGH RST AT 23Z AND LSE AT 03Z. THESE TIMES COULD EVEN BE PUSHED FURTHER BACK A FEW HOURS IF THE SUN DOES NOT MIX OUT MORE OF THE NORTHWEST SIDE OF THE CLOUDS. MVFR CEILINGS ARE ANTICIPATED TO PERSIST WHILE THE STRATUS IS AROUND. ONCE THE STRATUS CLEARS...WINDS WILL GO LIGHT AT LSE AS THE HIGH PRESSURE RIDGE AXIS MOVES IN. THIS SETS POTENTIAL VALLEY FOG. HAVE TRENDED THE FORECAST TOWARDS THIS POTENTIAL WITH A 4SM BR AND SCT003 DECK. HOWEVER...CONCERNS OF CLOUDS MOVING UP FROM THE SOUTH AS WELL AS TIMING THE CLEARING OF THE CURRENT STRATUS PRECLUDES GOING LOWER ON CEILINGS AND VISIBILITIES. ADDITIONALLY...LOW LEVEL WINDS ARE GOING TO INCREASE LATE IN THE NIGHT AHEAD OF A TROUGH DROPPING THROUGH MN...WHICH COULD DISRUPT THE VALLEY FOG/STRATUS PROCESS. THERE COULD ALSO BE SOME MVFR BR AT RST BUT THINK WINDS WILL BE STRONG ENOUGH TO PREVENT IT. VFR CONDITIONS ARE EXPECTED AT BOTH TAF SITES AFTER ANY FOG MIXES OUT IN THE MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....AJ