Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/27/15


AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
901 PM PDT MON OCT 26 2015 .SYNOPSIS...MILD TEMPERATURES AND DRY WEATHER CONDITIONS WILL PERSIST THROUGH MUCH OF TUESDAY. A PACIFIC SYSTEM WILL THEN BRING A FRONTAL BOUNDARY ACROSS THE REGION LATE TUESDAY INTO WEDNESDAY AND RESULT IN INCREASED CHANCES FOR PRECIPITATION. IN WAKE OF THE SYSTEM...COOLER TEMPERATURES AND BREEZY NORTHERLY WINDS ARE FORECAST THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 8:44 PM PDT MONDAY...SATELLITE IMAGERY SHOWS A LARGE SWATH OF HIGH CLOUDS MOVING OUT AHEAD OF THE COLD FRONT THAT IS CURRENTLY STRETCHED ACROSS THE EASTERN PACIFIC. HIGH CLOUDS STREAMING ACROSS THE FORECAST AREA ARE MAKING IT HARD TO SEE WHAT IS GOING ON AT THE SURFACE. HOWEVER OBSERVATIONS ALONG THE COAST REVEAL LOW CLOUDS PERSIST UNDER A SHALLOW 800 FOOT MARINE LAYER PER THE FORT ORD PROFILER. THE BLANKET OF HIGH CLOUDS ADVECTING OVER THE REGION WILL HAMPER FURTHER DEVELOPMENT OF LOW CLOUDS OVERNIGHT AND THEREFORE KEEP THE LOW CLOUDS CONFINED PRIMARILY TO THE COAST AND LOCALLY INTO COASTAL VALLEYS AND BAYS. COOL OVERNIGHT LOWS ARE EXPECTED ONCE AGAIN WITH TEMPS DIPPING DOWN INTO THE MID 40S TO MID 50S IN MOST LOCATIONS. A GRADUAL COOLING TREND IS FORECAST THROUGH MIDWEEK AS THE COLD FRONT MENTIONED ABOVE MOVES ACROSS THE REGION. MODELS AGREE THAT THE APPROACHING FRONT WILL SPREAD PRECIP ACROSS THE DISTRICT...HOWEVER DISCREPANCIES REMAIN IN THE TIMING AND INTENSITY OF THE PRECIPITATION. THE EURO HAS THE WETTEST AND FASTEST SOLUTION WHILE THE GFS LAGS ONLY SLIGHTLY BEHIND. THE 12Z EURO BRINGS LIGHT PRECIP TO THE NORTH BAY AS EARLY AS 18Z ON TUESDAY. WHILE THIS SEEMS EARLY THE LATEST RUN OF THE HRRR SHOWS LIGHT SHOWERS ACROSS THE NORTHERNMOST PORTION OF SONOMA COUNTY AROUND 16Z TUESDAY. THE EURO SPREADS SHOWERS SOUTHWARD TOWARD THE SAN FRANCISCO BAY BY 00Z WEDNESDAY WITH THE BULK OF THE PRECIP REACHING THE NORTH BAY AROUND 06Z WEDNESDAY. THE GFS SHOWS A FEW SHOWERS TUESDAY EVENING HOWEVER THE MAIN BAND OF PRECIP DOESN`T REACH THE NORTH BAY TIL WELL AFTER 12Z WEDNESDAY. THE CURRENT FORECAST BRINGS IN A CHANCE OF RAIN TO THE NORTH BAY TUESDAY AFTERNOON WITH CHANCES INCREASING AND SPREADING SOUTH TUESDAY EVENING INTO WEDNESDAY. THIS SOLUTIONS SPLITS THE DIFFERENCE AND IS REASONABLE AT THIS TIME. WILL NOT BE MAKING ANY SIGNIFICANT CHANGES TO THE FORECAST PACKAGE. FROM PREVIOUS DISCUSSION...LIGHT RAIN IS FORECAST TO SPREAD OVER THE SAN FRANCISCO BAY AREA LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. WHILE THE PWAT VALUES ARE FORECAST TO PEAK BETWEEN 1.10" AND 1.30" OVER THE REGION...THE AVAILABLE MOISTURE WILL BE MORE LIMITED OVER THE CENTRAL COAST AS THE BOUNDARY PUSHES THROUGH WEDNESDAY MORNING. HAVING SAID THAT...DO EXPECT MOST LOCATIONS WILL RECEIVE SOME RAINFALL FROM THIS SYSTEM. THE GREATEST RAINFALL AMOUNTS FROM TOMORROW NIGHT INTO WEDNESDAY WILL BE OVER THE NORTH BAY WHERE COASTAL RANGES COULD PICK UP BETWEEN 0.25" TO 0.50" FROM THIS SYSTEM. THE REST OF THE BAY AREA COULD PICK UP BETWEEN 0.10" TO 0.25" WITH GENERALLY LESS THAN 0.10" FURTHER SOUTH. AS TYPICAL WITH THESE SYSTEMS...OTHER COASTAL RANGES FROM THE SANTA CRUZ MOUNTAINS SOUTHWARD COULD PICK UP 0.25" IN ISOLATED LOCATIONS. ONCE THE MAIN TROUGH SHIFTS INLAND WEDNESDAY AFTERNOON...LINGERING SHOWERS WILL BE POSSIBLE INTO THE LATE AFTERNOON AS THE UPPER LEVEL JET DEVELOPS ALOFT. BY LATE WEDNESDAY NIGHT...MUCH OF THE MOISTURE AND UPPER LEVEL SUPPORT WILL BE FAR ENOUGH INLAND TO BRING AN END TO PRECIPITATION OVER THE REGION. AS THE MAIN MID/UPPER LEVEL TROUGH SHIFTS INLAND AND DIVES INTO THE FOUR CORNERS REGION THURSDAY INTO FRIDAY...THE SURFACE PRESSURE GRADIENT WILL TIGHTEN OVER THE AREA AND RESULT IN BREEZY TO WINDY CONDITIONS. THE STRONGEST WINDS WILL BE IN THE HIGHER ELEVATIONS WITH GUSTS TO 40 MPH POSSIBLE...WITH GUSTS TO 30 MPH EXPECTED REGION- WIDE. WIND SPEEDS WILL THEN RELAX LATE FRIDAY INTO SATURDAY AS HIGH PRESSURE BUILDS OVER THE REGION. IN ADDITION...THIS WILL ALLOW FOR A SLIGHT WARMING TREND THROUGH SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO SHOW SIGNS OF ANOTHER WEATHER SYSTEM DROPPING DOWN ACROSS OUR REGION THIS UPCOMING SUNDAY INTO NEXT MONDAY. && .AVIATION...AS OF 4:55 PM PDT MONDAY...MID TO HIGH CLOUDS ARE FORECAST TO RETURN ACROSS THE REGION IN ADVANCE OF AN APPROACHING STORM SYSTEM. LOWER CLOUDS ARE FORECAST TO MOVE TO MORE TERMINALS THIS EVENING AND INTO THE OVERNIGHT HOURS. WINDS WILL GENERALLY STAY UNDER 10 KT. OVERALL MODERATE CONFIDENCE. VICINITY OF KSFO...ONLY MINOR CHANGES FROM THE PREVIOUS TAF PACKAGE WITH MVFR FORECAST TO RETURN AROUND 08Z. HIGH CLOUDS MOVING ACROSS THE TERMINAL WILL COMPLICATE THE PICTURE A BIT. MODERATE CONFIDENCE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR RETURNS OVERNIGHT CLOSE TO 10Z WITH WINDS UNDER 10 KT. VFR RETURNS AROUND 17Z TOMORROW. MODERATE CONFIDENCE. && .MARINE...AS OF 8:41 PM PDT MONDAY...NORTHWESTERLY WINDS WILL PREVAIL INTO TUESDAY AFTERNOON WITH HIGHER GUSTS LIKELY UNTIL MIDNIGHT. WINDS WILL BECOME SOUTHERLY FOR A SHORT PERIOD OF TIME TUESDAY EVENING AHEAD OF AN APPROACHING STORM SYSTEM. THE FIRST WINTER SWELL OF THE SEASON IS EXPECTED TO ARRIVE ON WEDNESDAY WITH A SWELL OF 18 TO 20 SECONDS. PLEASE BE PREPARED FOR ROUGH CONDITIONS ACROSS THE SAN FRANCISCO AND BREAKING WAVES NEAR OFFSHORE REEFS AND SAND BARS. NORTHERLY WINDS ARE EXPECTED TO STRENGTHEN THURSDAY AS COOL AIR FILTERS IN BEHIND THE DEPARTING STORM SYSTEM. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...NONE. $$ PUBLIC FORECAST: CW AVIATION: BELL MARINE: LARRY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
211 AM CDT SUN OCT 25 2015 .UPDATE... 816 PM CDT MINOR TWEAKS TO GOING FORECAST THIS EVENING...MAINLY TO INCLUDE A FEW SPRINKLES ACROSS THE FAR EASTERN CWA FOR THE NEXT COUPLE OF HOURS...AND TO ADD SOME DETAIL TO HOURLY SKY CONDITIONS GRIDS WITH CLEARING WORKING IN FROM THE WEST LATE THIS EVENING/OVERNIGHT. THE COLD FRONT WHICH CLEARED THE FORECAST AREA LATE THIS AFTERNOON CONTINUES TO PUSH OFF TO THE SOUTHEAST THIS EVENING...WITH STRONG SURFACE PRESSURE RISES ANALYZED ACROSS THE WESTERN GREAT LAKES REGION AS THE LOW PRESSURE SYSTEM PULLS AWAY AND HIGH PRESSURE SPREADS IN FROM THE WEST. A FEW SPRINKLES HAVE BEEN REPORTED ACROSS THE EASTERN PART OF THE CWA...AND CAN BE SEEN IN 88D REFLECTIVITY CLEAR-AIR MODE...AND APPEAR TO BE ASSOCIATED WITH LINGERING MOISTURE AND F-GEN FORCING GENERATED BY COLD ADVECTION IN 950-850 MB LAYER. HIGH-RES GUIDANCE INDICATES THIS SHOULD WEAKEN/MOVE EAST OF THE CWA FAIRLY QUICKLY THIS EVENING...BUT HAVE ADDED A MENTION OF ISOLATED SPRINKLES GENERALLY EAST OF THE I-55 CORRIDOR AND INTO NORTHWEST INDIANA FOR THE NEXT COUPLE OF HOURS. GOES SATELLITE IMAGERY DEPICTS FAIRLY EXTENSIVE CLOUD COVER LINGERS ALMOST BACK TO THE MISSISSIPPI RIVER...WITH EXTRAPOLATION BRINGING THE TRAILING EDGE INTO THE RFD AREA BY LATE EVENING AND INTO THE CHICAGO AROUND/JUST AFTER MIDNIGHT. SATELLITE ALSO DEPICTS A FAIRLY DENSE AREA OF HIGHER CIRRUS CLOUD COVER FROM OUR SOUTHERN CWA SOUTH...AND THIS MAY LINGER ACROSS THE FAR SOUTHERN COUNTIES AFTER THE LOW CLOUDS CLEAR THERE LATER TONIGHT. THUS CLEAR SKIES MORE LIKELY ACROSS NORTHERN IL NORTH OF I-80 OR SO... WITH SOME LINGERING HIGH CLOUDS SOUTH. WINDS HAVE REMAINED BREEZY/GUSTY FROM THE NORTHWEST THIS EVENING WITH COLD ADVECTION AND THE CLOUD COVER HELPING KEEP THE BOUNDARY LAYER MIXED...THOUGH THIS SHOULD DIMINISH WITH THE STRONGEST PRESSURE RISES MOVING EAST OF THE AREA AND WEAKENING OF GRADIENT AS WELL AS EVENTUAL CLEARING HELPING TO ALLOW COOLING AND DECOUPLING OF THE SURFACE LAYER. TEMP FORECAST APPEARS ON TRACK WITH READINGS SLOWLY COOLING OFF THROUGH THE LOWER 50S AND 40S THROUGH THE NIGHT...WITH OVERNIGHT LOWS RANGING FROM THE MID 30S OVER NORTHERN IL WHERE CLEAR SKIES AND LIGHTEST WINDS ALLOW MOST EFFECTIVE COOLING...AND LOWER 40S IN THE FAR EAST/SOUTHEAST. RATZER && .SHORT TERM... TONIGHT AND SUNDAY... 228 PM...THE COLD FRONT HAS MOVED EAST INTO INDIANA WITH COOLER AIR NOW ADVECTING INTO THE REGION. AS THIS OCCURS...SOME DRIZZLE/LIGHT SHOWERS HAVE DEVELOPED. SHORT RANGE HRRR HINTED AT THIS AND CONTINUES TO DEVELOP MORE LIGHT PRECIP THRU THE LATE AFTERNOON...AS IT SLOWLY SHIFTS EAST. INCLUDED SLIGHT CHANCE POPS THRU LATE THIS AFTERNOON BUT OVERALL CONFIDENCE REGARDING DURATION AND COVERAGE IS LOW. WRAP AROUND CLOUD COVER IS QUITE EXTENSIVE WITH THE CLEARING LINE BACK ACROSS NORTHWEST WI INTO EAST CENTRAL IA. IT CURRENTLY APPEARS TO BE MAKING STEADY PROGRESS AND IF THIS TREND CONTINUES AS IS EXPECTED...SHOULD SEE CLEARING SKIES FROM MID EVENING IN THE WEST TO AFTER MIDNIGHT IN THE EAST. AND WITH HIGH PRESSURE BUILDING ACROSS THE AREA TONIGHT...NORTHWEST WINDS SHOULD BECOME LIGHT OVERNIGHT AND POSSIBLY CALM BY MORNING. THE HIGH THEN SLOWLY MOVES EAST ACROSS THE AREA SUNDAY WITH LIGHT WINDS EXPECTED THRU MUCH OF THE DAY. DESPITE HIGH TEMPS ONLY WARMING TO THE UPPER 50S/LOWER 60S...A LAKE BREEZE MAY STILL DEVELOP IN THE AFTERNOON. CMS && .LONG TERM... 237 PM CDT SUNDAY NIGHT THROUGH SATURDAY... THE LONGER TERM FORECAST PERIOD WILL START OUT RELATIVELY QUIET AS A LARGE AREA OF HIGH PRESSURE...EXTENDS FROM THE CANADIAN PRAIRIES THROUGH THE GREAT LAKES AND INTO THE MID ATLANTIC REGION. THE HIGH PRESSURE WILL GRADUALLY SLIDE OFF TO THE EAST AS A HYBRID SUB- TROPICAL LOW DEVELOPING AS THE REMNANTS OF HURRICANE PATRICIA INTERACTS WITH SRN STREAM...MID LATITUDE SHORT WAVE ENERGY. THE MODELS ARE RELATIVELY CONSISTENT IN TRACKING THIS LOW TO THE LOWER MS VALLEY BY MONDAY MORNING AND THEN LIFTS NORTH AS LONG WAVE TROUGHING DEVELOPS OVER THE WESTERN PLAINS. WHILE THERE ARE STILL SOME MINOR TIMING AND INTENSITY DIFFERENCES AMONG THE MODELS IN THE EVOLUTION OF THIS SYSTEM...THE GENERAL TREND IS FOR A STRONG NRN STREAM SHORTWAVE TO DROP OUT OF CNTRL CANADA AND INTO THE UPPER MS VALLEY BY TUESDAY NIGHT OR WEDNESDAY...TAPPING SOME OF THE RESIDUAL TROPICAL MOISTURE. CURRENT THINKING IS THAT THE NRN STREAM SHORTWAVE WILL NOT SO MUCH PHASE WITH THE REMNANT TROPICAL SYSTEM...BUT TAP SOME OF THE TROPICAL MOISTURE...SETTING UP A PERIOD WET WEATHER FOR THE MIDDLE OF NEXT WEEK. THE LONGER RANGE GUIDANCE IS CURRENTLY INDICATING PWATS IN EXCESS OF 1.25 INCHES WITH THIS SYSTEM. THE MOST FAVORABLE PERIOD FOR HEAVIER RAIN SHOULD BE TUESDAY INTO EARLY WEDNESDAY...AHEAD OF AN ASSOCIATED COLD FRONT. SOME MODEST INSTABILITY MAY REACH INTO CENTRAL IL...AND PERHAPS AS FAR NORTH AS THE ILLINOIS/KANKAKEE RIVERS...SO HAVE INCLUDED A SLIGHT CHANCE TS FOR THE SRN PORTIONS OF THE CWA. MODERATE TO...LOCALLY...HEAVY RAINFALL IS POSSIBLE DURING THIS PERIOD. THE COLD FRONT SHOULD QUICKLY PUSH THROUGH THE AREA ON WEDNESDAY. FOLLOWING THE PASSAGE OF THE SFC COLD FRONT...THE PARENT SFC LOW IS EXPECTED TO UNDERGO RAPID INTENSIFICATION OVER THE UPPER GREAT LAKES...WHICH SHOULD SET UP BREEZY CONDITIONS FOR WEDNESDAY AND THURSDAY. ANOTHER LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE REGION LATE NEXT WEEK...SETTLING CONDITIONS ACROSS THE REGION. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NONE. //DISCUSSION...UPDATED 06Z... SPRAWLING HIGH PRESSURE FROM THE CENTRAL PLAINS WILL GRADUALLY BUILD INTO THE AREA BY LATE MORNING BRINGING A DIMINISHING TO THE NORTHWEST WINDS. A FEW LAKE EFFECT CLOUDS MAY LINGER INTO GYY THROUGH MID-MORNING BUT SHOULD BE VFR. WINDS ARE LIKELY TO BE VARIABLE AT TIMES TODAY WHICH MAY ALLOW FOR A WEAK LAKE BREEZE TO DEVELOP. THE MOMENTUM OF THIS WILL BE WEAK THOUGH WITH SPEEDS REMAINING LIGHT. //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH IN ALL ELEMENTS INCLUDING THAT WINDS TODAY WILL REMAIN BELOW 9 KT. //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR. TUESDAY...RAIN LIKELY. MVFR LIKELY...IFR POSSIBLE. WEDNESDAY...CHANCE OF SHOWERS. MVFR LIKELY. THURSDAY...MVFR CIGS POSSIBLE. FRIDAY...VFR. MTF/IZZI && .MARINE... 209 AM CDT NORTHERLY WINDS WILL CONTINUE TO EASE THIS MORNING AS HIGH PRESSURE PUSHES IN FROM THE WEST. WAVES WITHIN THE INDIANA NEARSHORE WILL BE SLOWER TO SUBSIDE GIVEN THE FETCH AND SMALL CRAFT ADVISORY WAVES WILL LINGER THROUGH MID TO POSSIBLY LATE MORNING. WINDS WILL TURN SOUTHERLY OVER THE LAKE LATE TONIGHT INTO MONDAY BEFORE BECOMING EASTERLY MONDAY NIGHT. AS LOW PRESSURE RESPONSIBLE FOR THE HEAVY RAIN ACROSS SOUTHERN STATES MOVES NORTHWARD INTO THE MID-MISSISSIPPI VALLEY...THESE EASTERLY WINDS WILL INCREASE TO EASILY SMALL CRAFT ADVISORY CRITERIA...WITH THE WAVES BUILDING WITHIN ILLINOIS AND WISCONSIN NEARSHORES. THIS LOW PRESSURE IS FORECAST TO CONSIDERABLY DEEPEN LATER TUESDAY NIGHT INTO WEDNESDAY AS IT MOVES NORTH OVER OR NEAR LAKE MICHIGAN. AN ASSOCIATED COLD FRONT IS EXPECTED TO SWING THROUGH THE LAKE SOMETIME LATE WEDNESDAY TO WEDNESDAY EVENING. SUCH A PATTERN CERTAINLY POINTS TOWARD WESTERLY TO NORTHWESTERLY GALES BEHIND THAT FRONT...ALTHOUGH SPECIFICS ON TIMING AND INTENSITY OF THE SYSTEM FOR MAXIMUM WIND STRENGTH...WILL NEED TO BE REFINED IN TIME. A QUIET TAIL END OF THE WEEK LOOKS TO BE THE CASE BEHIND THAT SYSTEM. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM SUNDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1211 AM CDT SUN OCT 25 2015 .UPDATE... 816 PM CDT MINOR TWEAKS TO GOING FORECAST THIS EVENING...MAINLY TO INCLUDE A FEW SPRINKLES ACROSS THE FAR EASTERN CWA FOR THE NEXT COUPLE OF HOURS...AND TO ADD SOME DETAIL TO HOURLY SKY CONDITIONS GRIDS WITH CLEARING WORKING IN FROM THE WEST LATE THIS EVENING/OVERNIGHT. THE COLD FRONT WHICH CLEARED THE FORECAST AREA LATE THIS AFTERNOON CONTINUES TO PUSH OFF TO THE SOUTHEAST THIS EVENING...WITH STRONG SURFACE PRESSURE RISES ANALYZED ACROSS THE WESTERN GREAT LAKES REGION AS THE LOW PRESSURE SYSTEM PULLS AWAY AND HIGH PRESSURE SPREADS IN FROM THE WEST. A FEW SPRINKLES HAVE BEEN REPORTED ACROSS THE EASTERN PART OF THE CWA...AND CAN BE SEEN IN 88D REFLECTIVITY CLEAR-AIR MODE...AND APPEAR TO BE ASSOCIATED WITH LINGERING MOISTURE AND F-GEN FORCING GENERATED BY COLD ADVECTION IN 950-850 MB LAYER. HIGH-RES GUIDANCE INDICATES THIS SHOULD WEAKEN/MOVE EAST OF THE CWA FAIRLY QUICKLY THIS EVENING...BUT HAVE ADDED A MENTION OF ISOLATED SPRINKLES GENERALLY EAST OF THE I-55 CORRIDOR AND INTO NORTHWEST INDIANA FOR THE NEXT COUPLE OF HOURS. GOES SATELLITE IMAGERY DEPICTS FAIRLY EXTENSIVE CLOUD COVER LINGERS ALMOST BACK TO THE MISSISSIPPI RIVER...WITH EXTRAPOLATION BRINGING THE TRAILING EDGE INTO THE RFD AREA BY LATE EVENING AND INTO THE CHICAGO AROUND/JUST AFTER MIDNIGHT. SATELLITE ALSO DEPICTS A FAIRLY DENSE AREA OF HIGHER CIRRUS CLOUD COVER FROM OUR SOUTHERN CWA SOUTH...AND THIS MAY LINGER ACROSS THE FAR SOUTHERN COUNTIES AFTER THE LOW CLOUDS CLEAR THERE LATER TONIGHT. THUS CLEAR SKIES MORE LIKELY ACROSS NORTHERN IL NORTH OF I-80 OR SO... WITH SOME LINGERING HIGH CLOUDS SOUTH. WINDS HAVE REMAINED BREEZY/GUSTY FROM THE NORTHWEST THIS EVENING WITH COLD ADVECTION AND THE CLOUD COVER HELPING KEEP THE BOUNDARY LAYER MIXED...THOUGH THIS SHOULD DIMINISH WITH THE STRONGEST PRESSURE RISES MOVING EAST OF THE AREA AND WEAKENING OF GRADIENT AS WELL AS EVENTUAL CLEARING HELPING TO ALLOW COOLING AND DECOUPLING OF THE SURFACE LAYER. TEMP FORECAST APPEARS ON TRACK WITH READINGS SLOWLY COOLING OFF THROUGH THE LOWER 50S AND 40S THROUGH THE NIGHT...WITH OVERNIGHT LOWS RANGING FROM THE MID 30S OVER NORTHERN IL WHERE CLEAR SKIES AND LIGHTEST WINDS ALLOW MOST EFFECTIVE COOLING...AND LOWER 40S IN THE FAR EAST/SOUTHEAST. RATZER && .SHORT TERM... TONIGHT AND SUNDAY... 228 PM...THE COLD FRONT HAS MOVED EAST INTO INDIANA WITH COOLER AIR NOW ADVECTING INTO THE REGION. AS THIS OCCURS...SOME DRIZZLE/LIGHT SHOWERS HAVE DEVELOPED. SHORT RANGE HRRR HINTED AT THIS AND CONTINUES TO DEVELOP MORE LIGHT PRECIP THRU THE LATE AFTERNOON...AS IT SLOWLY SHIFTS EAST. INCLUDED SLIGHT CHANCE POPS THRU LATE THIS AFTERNOON BUT OVERALL CONFIDENCE REGARDING DURATION AND COVERAGE IS LOW. WRAP AROUND CLOUD COVER IS QUITE EXTENSIVE WITH THE CLEARING LINE BACK ACROSS NORTHWEST WI INTO EAST CENTRAL IA. IT CURRENTLY APPEARS TO BE MAKING STEADY PROGRESS AND IF THIS TREND CONTINUES AS IS EXPECTED...SHOULD SEE CLEARING SKIES FROM MID EVENING IN THE WEST TO AFTER MIDNIGHT IN THE EAST. AND WITH HIGH PRESSURE BUILDING ACROSS THE AREA TONIGHT...NORTHWEST WINDS SHOULD BECOME LIGHT OVERNIGHT AND POSSIBLY CALM BY MORNING. THE HIGH THEN SLOWLY MOVES EAST ACROSS THE AREA SUNDAY WITH LIGHT WINDS EXPECTED THRU MUCH OF THE DAY. DESPITE HIGH TEMPS ONLY WARMING TO THE UPPER 50S/LOWER 60S...A LAKE BREEZE MAY STILL DEVELOP IN THE AFTERNOON. CMS && .LONG TERM... 237 PM CDT SUNDAY NIGHT THROUGH SATURDAY... THE LONGER TERM FORECAST PERIOD WILL START OUT RELATIVELY QUIET AS A LARGE AREA OF HIGH PRESSURE...EXTENDS FROM THE CANADIAN PRAIRIES THROUGH THE GREAT LAKES AND INTO THE MID ATLANTIC REGION. THE HIGH PRESSURE WILL GRADUALLY SLIDE OFF TO THE EAST AS A HYBRID SUB- TROPICAL LOW DEVELOPING AS THE REMNANTS OF HURRICANE PATRICIA INTERACTS WITH SRN STREAM...MID LATITUDE SHORT WAVE ENERGY. THE MODELS ARE RELATIVELY CONSISTENT IN TRACKING THIS LOW TO THE LOWER MS VALLEY BY MONDAY MORNING AND THEN LIFTS NORTH AS LONG WAVE TROUGHING DEVELOPS OVER THE WESTERN PLAINS. WHILE THERE ARE STILL SOME MINOR TIMING AND INTENSITY DIFFERENCES AMONG THE MODELS IN THE EVOLUTION OF THIS SYSTEM...THE GENERAL TREND IS FOR A STRONG NRN STREAM SHORTWAVE TO DROP OUT OF CNTRL CANADA AND INTO THE UPPER MS VALLEY BY TUESDAY NIGHT OR WEDNESDAY...TAPPING SOME OF THE RESIDUAL TROPICAL MOISTURE. CURRENT THINKING IS THAT THE NRN STREAM SHORTWAVE WILL NOT SO MUCH PHASE WITH THE REMNANT TROPICAL SYSTEM...BUT TAP SOME OF THE TROPICAL MOISTURE...SETTING UP A PERIOD WET WEATHER FOR THE MIDDLE OF NEXT WEEK. THE LONGER RANGE GUIDANCE IS CURRENTLY INDICATING PWATS IN EXCESS OF 1.25 INCHES WITH THIS SYSTEM. THE MOST FAVORABLE PERIOD FOR HEAVIER RAIN SHOULD BE TUESDAY INTO EARLY WEDNESDAY...AHEAD OF AN ASSOCIATED COLD FRONT. SOME MODEST INSTABILITY MAY REACH INTO CENTRAL IL...AND PERHAPS AS FAR NORTH AS THE ILLINOIS/KANKAKEE RIVERS...SO HAVE INCLUDED A SLIGHT CHANCE TS FOR THE SRN PORTIONS OF THE CWA. MODERATE TO...LOCALLY...HEAVY RAINFALL IS POSSIBLE DURING THIS PERIOD. THE COLD FRONT SHOULD QUICKLY PUSH THROUGH THE AREA ON WEDNESDAY. FOLLOWING THE PASSAGE OF THE SFC COLD FRONT...THE PARENT SFC LOW IS EXPECTED TO UNDERGO RAPID INTENSIFICATION OVER THE UPPER GREAT LAKES...WHICH SHOULD SET UP BREEZY CONDITIONS FOR WEDNESDAY AND THURSDAY. ANOTHER LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE REGION LATE NEXT WEEK...SETTLING CONDITIONS ACROSS THE REGION. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NONE. //DISCUSSION...UPDATED 06Z... SPRAWLING HIGH PRESSURE FROM THE CENTRAL PLAINS WILL GRADUALLY BUILD INTO THE AREA BY LATE MORNING BRINGING A DIMINISHING TO THE NORTHWEST WINDS. A FEW LAKE EFFECT CLOUDS MAY LINGER INTO GYY THROUGH MID-MORNING BUT SHOULD BE VFR. WINDS ARE LIKELY TO BE VARIABLE AT TIMES TODAY WHICH MAY ALLOW FOR A WEAK LAKE BREEZE TO DEVELOP. THE MOMENTUM OF THIS WILL BE WEAK THOUGH WITH SPEEDS REMAINING LIGHT. //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH IN ALL ELEMENTS INCLUDING THAT WINDS TODAY WILL REMAIN BELOW 9 KT. //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR. TUESDAY...RAIN LIKELY. MVFR LIKELY...IFR POSSIBLE. WEDNESDAY...CHANCE OF SHOWERS. MVFR LIKELY. THURSDAY...MVFR CIGS POSSIBLE. FRIDAY...VFR. MTF/IZZI && .MARINE... 237 PM CDT THE CENTER OF LOW PRESSURE IS MOVING INTO SWRN ONTARIO THIS AFTERNOON WHILE DRAGGING A COLD FRONT ACROSS LAKE MICHIGAN. A SHORT PERIOD OF GALES IS EXPECTED FOR THE NORTHERN PORTIONS OF THE LAKE AS STRONG PRESSURE RISES IN THE WAKE OF THE EXITING LOW COMBINES WITH COLD ADVECTION BEHIND THE COLD FRONT. WINDS SHOULD BEING TO DIMINISH LATE THIS EVENING AS HIGH PRESSURE OVERSPREADS THE WRN GREAT LAKES. HIGH PRESSURE SHOULD PREVAIL OVER THE GREAT LAKES FROM SUNDAY THROUGH MONDAY NIGHT OR TUESDAY. LOW PRESSURE DEVELOPING ALONG THE TX GULF COAST THIS EVENING...DEVELOPING AS THE REMNANTS OF PATRICIA INTERACTS WITH MID-LATITUDE SHORTWAVE ENERGY...WILL SLOWLY MOVE ACROSS THE NWRN GLFMEX TO THE LOWER MS VALLEY MONDAY EVENING. THIS LOW WILL CONTINUE TO SLOWLY LIFT NORTH AS THE HIGH PRESSURE MOVES OVER NEW ENGLAND EARLY NEXT WEEK...SETTING UP A PERIOD OF BRISK SELY-ELY WINDS OVER THE LAKE THROUGH TUESDAY INTO EARLY WEDNESDAY MORNING. THIS LOW IS EXPECTED TO CONTINUE TO TRACK NORTH...WEST OF LAKE MICHIGAN ON WEDNESDAY AND THEN MERGE WITH ANOTHER LOW DROPPING OUT OF THE NRN PLAINS...NEAR LAKE SUPERIOR...RAPIDLY DEEPENING AS IT TURNS EAST ACROSS THE UPPER GREAT LAKES. A PERIOD OF GALES IS POSSIBLE BY LATE NEXT WEEK AS THE TWO LOWS CONSOLIDATE INTO A SINGLE DEEPENING LOW OVER THE UPPER GREAT LAKES. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM SUNDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
725 PM EDT MON OCT 26 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 419 PM EDT MON OCT 26 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE UPPER GREAT LAKES ON THE SRN PERIPHERY OF AN ERN CANADA TROF ANCHORED BY A DEEP MID LEVEL LOW CENTERED JUST N OF HUDSON BAY. WITHIN THE TROF...110KT UPPER JET EXTENDS FROM NE MN TO NEW ENGLAND. RIGHT ENTRANCE UPPER DIVERGENCE ASSOCIATED WITH THE JET...CORRESPONDING FGEN IN THE LOWER TO MID LEVELS...AND SHORTWAVE HAVE SUPPORTED SHRA FROM NW WI E ACROSS UPPER MI TODAY...THOUGH SHRA HAVE BEEN CONFINED TO ROUGHLY THE SRN HALF OF THE U.P. OTHERWISE...IT`S BEEN A CLOUDY DAY. HOWEVER...RECENTLY MID CLOUDS HAVE CLEARED OUT OVER THE KEWEENAW WITH DAYTIME HEATING NOW LEADING TO SOME DIURNAL CU/STRATOCU DEVELOPMENT THERE. TEMPS ARE IN THE 40S ACROSS THE FCST AREA...BUT ARE NEARING 50F ON THE KEWEENAW AND HAVE RISEN INTO THE LOW/MID 50S IN MENOMINEE COUNTY. WITH FORCING THAT HAS GENERATED THE SHRA TODAY BREAKING DOWN THIS EVENING...EXPECT A DIMINISHING TREND TO THE SHRA AS MODELS INDICATE. HOWEVER...ONGOING WAA AHEAD OF TROF SWINGING ACROSS THE ROCKIES MAY WORK TO GENERATE ISOLD -SHRA/SPRINKLES ALONG THE CURRENT PCPN GENERATION ZONE THAT IS SLOWLY LIFTING NE AS SEEN ON RADAR IMAGERY LOOPS ACROSS NW WI TO AROUND KDLH. TO ACCOUNT FOR THIS POSSIBILITY...LINGERED SOME SCHC POPS W INTO PORTIONS OF WRN UPPER THRU THE EVENING. TROF MOVING ACROSS THE ROCKIES TONIGHT SHIFTS OUT OVER THE PLAINS TUE. AHEAD OF THE TROF...MODELS SHOW BETTER FOCUS OF WAA SHIFTING TO THE NW OF UPPER MI. END RESULT WILL BE A DRY DAY...BUT WITH CONSIDERABLE MID AND HIGH CLOUDS OVERSPREADING THE AREA. DESPITE CLOUD COVER...TEMPS WILL TOP OUT A LITTLE ABOVE NORMAL IN THE LOW/MID 50S. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 423 PM EDT MON OCT 26 2015 MUCH OF THIS PERIOD WILL BE DOMINATED BY STEADY RAIN WEDNESDAY THEN COOLER/BREEZY CONDITIONS WITH LAKE EFFECT RAIN AND SNOW SHOWERS THURSDAY INTO FRIDAY. AT 00Z WEDNESDAY UPPER MI WILL BE IN BETWEEN A STRONG SFC HIGH PUSHING OFF THE NEW ENGLAND COAST...AND AN ELONGATED AREA OF LOW PRESSURE STRETCHING FROM THE N SASKATCHEWAN AND MANITOBA BORDER TO NE...AND THE LOWER MS VALLEY /REMNANTS OF HURRICANE PATRICA/. WILL BE STARTING OUT WITH A STRONG S-SE PUSH OF AIR ON 850MB WINDS OF 25- 40KTS OVERHEAD. THESE 850MB WINDS WILL INCREASE TO AN AVERAGE 40KTS CWA WIDE OVERNIGHT. THE CONSOLIDATING AREA OF LOW PRESSURE WILL CONVERGE AND STRETCH FROM MANITOBA TO IL/IN BY DAYBREAK WEDNESDAY...WITH STEADY RAIN THROUGH MID AFTERNOON. PRECIP TOTALS EARLY WEDNESDAY MORNING THROUGH THE REST OF THE DAY WILL LIKELY TOTAL AROUND OR OVER 0.5IN. THE SFC LOW WILL THEN DEEPEN TO NEAR 990MB EARLY WEDNESDAY AFTERNOON ACROSS UPPER MI/N LAKE MI...AND AROUND 980MB ACROSS N OR NE LAKE SUPERIOR BY 00Z THURSDAY. SO AFTER A BRIEF LULL IN THE WINDS MIDDAY WEDNESDAY AS THE LOW PRESSES...EXPECT STRONGER W-NW WINDS TO PUSH IN WEDNESDAY NIGHT. RAIN WILL BEGIN TO MIX WITH AND CHANGE OVER TO SNOW MAINLY INLAND FROM THE GREAT LAKES AS 850MB TEMPS FALL FROM AROUND 3C WEDNESDAY AFTERNOON TO 0 TO -5C BY 12Z THURSDAY. THE CONSENSUS...WITH THE COLD AIR IS TO HAVE IT PUSH MAINLY INLAND OR S OF THE CWA. THIS RESULTS IN ONLY MODERATE CONFIDENCE IN THE TIMING OR AMOUNTS OF SNOW POSSIBLE BEHIND THE LOW...AS THERE IS SOME DISCREPANCY ON THE HANDLING OF THE 500MB LOW AS IT SINKS IN BEHIND THE SFC LOW. STILL...IT WILL BE A COOL AND BREEZY DAY WITH GALES LIKELY CENTRAL AND E OVER LAKE SUPERIOR. THE GFS AND CANADIAN SOLUTIONS ARE THE FARTHEST S WITH THE LOW...ACROSS CENTRAL LAKE MI AND S WI AT 06Z THURSDAY. BY CONTRAST...THE NAM/ECMWF/SREF SOLUTIONS HAVE THE LOW OVER UPPER MI. WILL BE INTERESTING HOW THIS FALLS OVER THE NEXT COUPLE OF DAYS. WILL CONTINUE WITH A BLENDED SOLUTION FOR NOW. CONFIDENCE INCREASES AT THE TAIL END OF THE MOISTURE AS IT DEPARTS THURSDAY AFTERNOON. NW WINDS AND COOLER AIR WITH 850MB TEMPS AVERAGING -4 TO -5C WOULD RESULT IN MAINLY SNOW IF SFC TEMPS WERE JUST A COUPLE OF DEGREES COOLER. OTHERWISE...LOOK FOR SLOWLY RISING TEMPS FOR HIGHS THROUGH MONDAY. THIS WILL BE AS THE SFC RIDGE BUILDS INTO MUCH OF THE E HALF OF THE NATION FRIDAY. THIS AREA OF HIGH PRESSURE WILL EXIT TO OUR E FRIDAY NIGHT...AS WE RESIDE IN BETWEEN THE DEPARTING HIGH AND NEARING AREA OF LOW PRESSURE ACROSS W AND CENTRAL CANADA. WILL BE HARD TO COMPLETELY RULE OUT PRECIP FRIDAY NIGHT THROUGH MONDAY /WITH THE BEST CHANCE MONDAY WITH LOW PRESSURE NEARBY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 724 PM EDT MON OCT 26 2015 WITH A LIGHT UPSLOPE SSE FLOW DVLPG OFF LK MI AND ADVECTING RA MOISTENED AIR INTO SAW IN THE PRESENCE OF NOCTURNAL COOLING... EXPECT CONDITIONS THERE TO DETERIORATE TO MVFR AND PERHAPS IFR DURING THE NGT. DOWNSLOPE NATURE OF THE LLVL FLOW WL LEAD TO VFR WX AT IWD. ALTHOUGH CMX WL BE DOMINATED BY LLVL DRY AIR THIS EVNG... SOME LO CLDS MAY IMPACT THAT SITE LATER TNGT AS THE FLOW SHIFTS MORE TO THE ESE. AS THE S WIND AHEAD OF DVLPG LO PRES TO THE W TAPS DRIER LLVL AIR ON TUE WITH DAYTIME HEATING...ANY LO CLDS WL GIVE WAY TO VFR CONDITIONS AT ALL 3 TAF SITES DESPITE PLENTY OF HIER CLDS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EDT MON OCT 26 2015 LIGHT WINDS MOSTLY UNDER 15KT WILL START THE FCST PERIOD TONIGHT ACROSS MOST OF LAKE SUPERIOR. WINDS OVER WRN LAKE SUPERIOR WILL GUST UP TOWARD 20KT. WINDS WILL BEGIN TO RAMP UP ON TUE AHEAD OF A COLD FRONT SWEEPING ACROSS THE PLAINS. AS THE COLD FRONT REACHES THE UPPER LAKES WED...LOW PRES WILL ORGANIZE ALONG THE FRONT. THE LOW WILL THEN RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY LATE TUE AFTN... INCREASING FURTHER TO 20-30KT TUE NIGHT. THE STRONGEST WINDS TUE NIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. NOT OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE GUSTS TUE NIGHT OVER CNTRL/ERN LAKE SUPERIOR...ESPECIALLY IN THE CARIBOU ISLAND/WHITEFISH POINT AREA. WINDS WILL TEMPORARILY DIMINISH IN THE VNCTY OF THE LOW/FRONT AS THEY MOVE ACROSS LAKE SUPERIOR WED. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED THRU THU WITH THE STRONGEST WINDS TO AROUND 40KT OVER THE E HALF OF THE LAKE. WINDS WILL DIMINISH TO UNDER 20KT W TO E THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
107 PM EDT SUN OCT 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 508 AM EDT SUN OCT 25 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH FROM HUDSON BAY INTO THE GREAT LAKES RESULTING IN WNW FLOW FROM SRN SASK/ALBERTA AND THE NRN PLAINS INTO THE WRN LAKES. A WEAK SHRTWV INTO LAKE SUPERIOR SUPPORTED AN AREA OF CLOUDS AND SOME ISOLATED LIGHT SHOWERS OR SPRINKLES OVER CNTRL/ERN LAKE SUPERIOR AND INTO N CNTRL UPPER MI. FARTHER UPSTREAM...A COUPLE OF SHORTWAVES OVER ALBERTA WILL INFLUENCE THE WEATHER TONIGHT. AT THE SFC...NW WINDS WERE DIMINISHING AS HIGH PRES OVER THE UPPER MS VALLEY BUILDS INTO THE REGION. TODAY...THE POTENTIAL REMAINS FOR A FEW LIGHT SHOWERS OR SPRINKLE OVER THE ERN CWA THROUGH THIS MORNING AS ANOTHER WEAK SHRTWV BRUSHES THE AREA. OTHERWISE...UNDER PARTLY TO MOSTLY CLOUDY SKIES TEMPS WILL REMAIN NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES WITH HIGHS IN THE MID 40S NORTH AND AROUND 50 SOUTH. TONIGHT...AS THE ALBERTA SHRTWVS NEAR THE REGION PCPN ASSOCIATED WITH A BAND OF 850-600 MB FGEN WILL DEVELOP. THE GFS/NAM/ECMWF AND HIGH RES MODELS REMAINED REASONABLY CONSISTENT IN KEEPING THE GREATEST PCPN AMOUNTS MAINLY THROUGH SRN UPPER MI NEAR THE WI BORDER. HOWEVER...SOME UNCERTAINTY REMAINS WITH THE POSITION OF THE BAND AS THE GEM PRODUCES PCPN ACROSS MOST OF UPPER MICHIGAN. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 508 AM EDT SUN OCT 25 2015 ...ACTIVE WEATHER WEEK EXPECTED... ACTIVE WEEK OF WEATHER IN STRORE WITH BEST CHANCE OF WIDESPREAD RAIN LATE TUESDAY NIGHT INTO WEDNESDAY AS DEEPENING LOW PRESSURE SYSTEM LIFTS THROUGH THE UPPER GREAT LAKES REGION. ENOUGH COOL AIR ON BACK SIDE OF THE SYSTEM TO HAVE SOME SNOW IN THE FORECAST LATE WEDNESDAY NIGHT INTO THURSDAY. SLIGHTLY WARMER CONDITIONS WILL RETURN BY NEXT WEEKEND. OUTLOOKS FM CPC INDICATE ABOVE NORMAL CONDITIONS COULD PERSIST INTO MUCH OF NOVEMBER AS STRONG EL NINO CONTINUES TO INFLUENCE THE OVERALL LARGER SCALE WEATHER PATTERN. STARTING OFF THE LONG TERM SHORTWAVE WILL BE DROPPING OVER NORTHERN MN INTO LK SUPERIOR BEFORE RIDGING BUILDS IN LATER MONDAY INTO MONDAY NIGHT. SFC TROUGH THAT MOVES THROUGH TODAY SHOULD BE SOUTH OF UPR MICHIGAN ON MONDAY BUT THE SHORTWAVE ALONG WITH RIBBON OF H85-H7 FRONTOGENESIS NORTH OF THE SFC TROUGH RESULTS IN WIDESPREAD BUT LIGHT RAIN OVER AT LEAST SOUTH HALF OF CWA. LIGHT RAIN MAY LIFT NORTH SLIGHTLY ON MONDAY AS THE SHORTWAVE BEGINS TO EXIT TO THE NORTHEAST. APPEARS KEWEENAW MISSES OUT ON MOST OF THE RAIN WITH THIS SYSTEM...THROUGH FARTHER NORTH GEM-REGIONAL WOULD BRING SOME RAIN UP TO HOUGHTON/HANCOCK. DECAYING RIBBON OF MOISTURE LINGERS INTO MONDAY EVENING...THOUGH EXACTLY WHERE IS NOT CERTAIN. SLIGHT CHANCES FOR CNTRL IN CASE A FEW SHOWERS OR SPRINKLES PERSIST. ATTN TUESDAY INTO TUESDAY NIGHT TURNS TO DEEPENING TROUGH FM CANADIAN PRAIRIES INTO THE CNTRL CONUS. COMPLICATED INTERACTION OF MULTIPLE SHORTWAVES AND ALSO REMNANTS OF HURRICANE PATRICIA OVER SCNTRL CONUS WILL CAUSE THE TROUGH TO DEEPEN. AT THE SFC...HIGH PRESSURE RIDGE WILL BUILD OVER THE LOWER GREAT LAKES TO THE MID ATLANTIC COAST WHILE LOW PRESSURE TROUGH DEVELOPS OVER THE CNTRL CONUS. WARM AIR ADVECTION ALOFT SHOULD BE OFFSET BY DRY LOW-LEVELS DUE TO HIGH IN THE VCNTY TO PROHIBIT MUCH RAIN ON TUESDAY. MOISTURE ADVECTION IN LOW-LEVELS FOCUSES OVER WEST LK SUPERIOR AND OVER MN SO THAT IS WHERE LOW POPS WILL RESIDE ON TUESDAY. SHOULD BE PLENTY OF MID-HIGH CLOUDS AROUND THOUGH. ON TUESDAY NIGHT...ONE PART OF UPPER LEVEL TROUGH DEEPENS AND MOVES OVER CNTRL PLAINS WHILE STRONGER SHORTWAVE TROUGH DIGS SOUTHEAST OVER SASKATCHEWAN AND MANITOBA. DEEP LAYER Q-VECTOR CONVERGENCE AND MOISTURE ADVECTION AHEAD OF DEEPENING SFC LOWS OVER MANITOBA AND OVER MO/ILL SHOULD RESULT IN SHIELD OF RAIN LIFTING ACROSS WESTERN GREAT LAKES. BULK OF RAIN WILL HOLD OFF TIL AFTER MIDNIGHT TO MOVE INTO CWA. SUPPOSE ESE WINDS AND INCREASING MOISTURE MAY ALLOW FOR A FEW SHOWERS TO FORM AS EARLY AS EVENING OVER UPSLOPE OF CENTRAL UPR MICHIGAN. PRETTY LOW CHANCE. RAIN SPREADS OVER ALL CWA BY DAYBREAK WED. RAIN SHOULD CONTINUE MUCH OF WED AS LARGE SCALE FORCING ONLY INCREASES DUE TO PHASING OF CANADIAN SHORTWAVE TROUGH AND SOUTHERN SHORTWAVE TROUGH LIFTING FM THE PLAINS TO THE OHIO VALLEY. SFC LOW OVER MO/ILL BECOMES MAIN PLAYER...DEEPENING TO 990-995MB WHILE REACHING SOMEWHERE VCNTY OF UPR MICHIGAN BY MIDDAY WED AND TO AROUND 985MB AS IT MOVES OVER LK SUPERIOR BY 00Z THU. DESPITE LOW CROSSING THE CWA ON WED...FORCING AND DEEP MOISTURE VIA THE SOUTHERN SHORTWAVE TROUGH APPEAR TO KEEP DRY SLOT AFFECTS TO A MINIMUM. TOTAL RAINFALL OF AT LEAST ONE QUARTER IF NOT ONE HALF INCH SHOULD RESULT FM THE SYSTEM...BUT GIVEN ALL THE INTERACTIONS THAT ARE FORECAST TO OCCUR ALOFT...SPECIFICS IN RAIN TIMING/EXTENT AND AMOUNTS MAY STILL CHANGE. ONCE THE LOW MOVES NORTH OF LK SUPERIOR TOWARD JAMES BAY WEDNESDAY NIGHT...COOLER AIR BEGINS TO WORK ACROSS UPPER GREAT LAKES. PROGS OF H85 TEMPS AND 1000- 850MB THICKNESSES FM GFS/ECMWF POINT TO COOLEST AIR STAYING OVER MN AND WI WHILE OCCLUDING LOW PRESSURE SYSTEM RESULTS IN SLIGHTLY WARMER AIR OVER UPR MICHIGAN. H85 TEMPS AT 12Z THU ARE -2C OVER LK SUPERIOR AND ONLY FALL TO AROUND -4C BY 00Z. LK SUPERIOR TEMPS ARE 8- 10C...SO PROBABLY JUST ENOUGH OVER-WATER INSTABILITY TO RESULT IN LAKE EFFECT PRECIPITATION...ESPECIALLY WITH CYCLONIC LOW-LEVEL FLOW AND WRAP AROUND MOISTURE. MIX OF RAIN/SNOW WOULD BE MOST FAVORED OVER HIGHER TERRAIN OF WESTERN UPR MICHIGAN LATE WED NIGHT INTO THU MORNING. NW WINDS WILL BE BREEZY NEAR LK SUPERIOR ON THU. HIGH TEMPERATURES ON THU LIKELY WILL STRUGGLE TO REACH 40 DEGREES OVER HIGHER TERRAIN OF WEST AND NCNTRL UPR MICHIGAN. UPPER LEVEL TROUGH BECOMES MORE PROGRESSIVE THURSDAY NIGHT INTO FRIDAY. H85 TEMPS FALL TO -6C TO -8C BY 12Z FRIDAY BUT WITH LESS CYCLONIC FLOW LOOKING AT PURE LAKE EFFECT BY THAT TIME. GFS IS COLDER AND WOULD POINT TO SMALL CHANCES FOR LAKE EFFECT ESPECIALLY NCNTRL AND EAST NEAR LK SUPERIOR INTO FRIDAY. FLOW ALOFT CONTINUES TO FLATTEN OUT FRIDAY INTO SATURDAY. GFS MORE AGGRESSIVE THAN ECMWF OR GEM IN BRINGING QPF INTO UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES BY SATURDAY. USED CONSENSUS WHICH ONLY HAS SMALL CHANCES. TEMPS SHOULD WARM TO AROUND NORMAL FOR THE LAST DAY OF OCTOBER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 107 PM EDT SUN OCT 25 2015 VFR CONDITIONS WILL CONTINUE AT KIWD UNTIL LATE TONIGHT WHEN RAIN MOVES INTO THE AREA AND CONDITIONS LOWER TO MVFR THERE LATE TONIGHT. AT KCMX...WILL GO VFR SHORTLY AND STAY THAT WAY THROUGH THE PERIOD AS THE RAIN WILL STAY SOUTH OF THEM. FOR KSAW...MVFR CLOUDS WITH UPSLOPE AND LAKE EFFECT COMPONENT WILL BE STUBBORN TO LEAVE THIS AFTERNOON...BUT WINDS WILL GO LIGHT ENOUGH BY THIS EVENING TO DISSIPATE THE MVFR DECK. MVFR CONDITIONS WILL MOVE BACK INTO KSAW LATE TONIGHT WITH THE RAIN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 508 AM EDT SUN OCT 25 2015 WINDS WILL DIMINISH TODAY AS HIGH PRESSURE BEGINS TO BUILD BACK OVER THE REGION. WINDS ARE EXPECTED TO REMAIN AOB 25 KTS INTO TUESDAY...BUT WILL INCREASE BY WEDNESDAY AS A LOW PRESSURE SYSTEM CROSSES THE UPPER GREAT LAKES. NW WINDS IN WAKE OF THE LOW ARE EXPECTED TO REACH NEAR OR JUST ABOVE GALE FORCE OVER PORTIONS CENTRAL AND EASTERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
732 AM EDT SUN OCT 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 508 AM EDT SUN OCT 25 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH FROM HUDSON BAY INTO THE GREAT LAKES RESULTING IN WNW FLOW FROM SRN SASK/ALBERTA AND THE NRN PLAINS INTO THE WRN LAKES. A WEAK SHRTWV INTO LAKE SUPERIOR SUPPORTED AN AREA OF CLOUDS AND SOME ISOLATED LIGHT SHOWERS OR SPRINKLES OVER CNTRL/ERN LAKE SUPERIOR AND INTO N CNTRL UPPER MI. FARTHER UPSTREAM...A COUPLE OF SHORTWAVES OVER ALBERTA WILL INFLUENCE THE WEATHER TONIGHT. AT THE SFC...NW WINDS WERE DIMINISHING AS HIGH PRES OVER THE UPPER MS VALLEY BUILDS INTO THE REGION. TODAY...THE POTENTIAL REMAINS FOR A FEW LIGHT SHOWERS OR SPRINKLE OVER THE ERN CWA THROUGH THIS MORNING AS ANOTHER WEAK SHRTWV BRUSHES THE AREA. OTHERWISE...UNDER PARTLY TO MOSTLY CLOUDY SKIES TEMPS WILL REMAIN NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES WITH HIGHS IN THE MID 40S NORTH AND AROUND 50 SOUTH. TONIGHT...AS THE ALBERTA SHRTWVS NEAR THE REGION PCPN ASSOCIATED WITH A BAND OF 850-600 MB FGEN WILL DEVELOP. THE GFS/NAM/ECMWF AND HIGH RES MODELS REMAINED REASONABLY CONSISTENT IN KEEPING THE GREATEST PCPN AMOUNTS MAINLY THROUGH SRN UPPER MI NEAR THE WI BORDER. HOWEVER...SOME UNCERTAINTY REMAINS WITH THE POSITION OF THE BAND AS THE GEM PRODUCES PCPN ACROSS MOST OF UPPER MICHIGAN. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 508 AM EDT SUN OCT 25 2015 ...ACTIVE WEATHER WEEK EXPECTED... ACTIVE WEEK OF WEATHER IN STRORE WITH BEST CHANCE OF WIDESPREAD RAIN LATE TUESDAY NIGHT INTO WEDNESDAY AS DEEPENING LOW PRESSURE SYSTEM LIFTS THROUGH THE UPPER GREAT LAKES REGION. ENOUGH COOL AIR ON BACK SIDE OF THE SYSTEM TO HAVE SOME SNOW IN THE FORECAST LATE WEDNESDAY NIGHT INTO THURSDAY. SLIGHTLY WARMER CONDITIONS WILL RETURN BY NEXT WEEKEND. OUTLOOKS FM CPC INDICATE ABOVE NORMAL CONDITIONS COULD PERSIST INTO MUCH OF NOVEMBER AS STRONG EL NINO CONTINUES TO INFLUENCE THE OVERALL LARGER SCALE WEATHER PATTERN. STARTING OFF THE LONG TERM SHORTWAVE WILL BE DROPPING OVER NORTHERN MN INTO LK SUPERIOR BEFORE RIDGING BUILDS IN LATER MONDAY INTO MONDAY NIGHT. SFC TROUGH THAT MOVES THROUGH TODAY SHOULD BE SOUTH OF UPR MICHIGAN ON MONDAY BUT THE SHORTWAVE ALONG WITH RIBBON OF H85-H7 FRONTOGENESIS NORTH OF THE SFC TROUGH RESULTS IN WIDESPREAD BUT LIGHT RAIN OVER AT LEAST SOUTH HALF OF CWA. LIGHT RAIN MAY LIFT NORTH SLIGHTLY ON MONDAY AS THE SHORTWAVE BEGINS TO EXIT TO THE NORTHEAST. APPEARS KEWEENAW MISSES OUT ON MOST OF THE RAIN WITH THIS SYSTEM...THROUGH FARTHER NORTH GEM-REGIONAL WOULD BRING SOME RAIN UP TO HOUGHTON/HANCOCK. DECAYING RIBBON OF MOISTURE LINGERS INTO MONDAY EVENING...THOUGH EXACTLY WHERE IS NOT CERTAIN. SLIGHT CHANCES FOR CNTRL IN CASE A FEW SHOWERS OR SPRINKLES PERSIST. ATTN TUESDAY INTO TUESDAY NIGHT TURNS TO DEEPENING TROUGH FM CANADIAN PRAIRIES INTO THE CNTRL CONUS. COMPLICATED INTERACTION OF MULTIPLE SHORTWAVES AND ALSO REMNANTS OF HURRICANE PATRICIA OVER SCNTRL CONUS WILL CAUSE THE TROUGH TO DEEPEN. AT THE SFC...HIGH PRESSURE RIDGE WILL BUILD OVER THE LOWER GREAT LAKES TO THE MID ATLANTIC COAST WHILE LOW PRESSURE TROUGH DEVELOPS OVER THE CNTRL CONUS. WARM AIR ADVECTION ALOFT SHOULD BE OFFSET BY DRY LOW-LEVELS DUE TO HIGH IN THE VCNTY TO PROHIBIT MUCH RAIN ON TUESDAY. MOISTURE ADVECTION IN LOW-LEVELS FOCUSES OVER WEST LK SUPERIOR AND OVER MN SO THAT IS WHERE LOW POPS WILL RESIDE ON TUESDAY. SHOULD BE PLENTY OF MID-HIGH CLOUDS AROUND THOUGH. ON TUESDAY NIGHT...ONE PART OF UPPER LEVEL TROUGH DEEPENS AND MOVES OVER CNTRL PLAINS WHILE STRONGER SHORTWAVE TROUGH DIGS SOUTHEAST OVER SASKATCHEWAN AND MANITOBA. DEEP LAYER Q-VECTOR CONVERGENCE AND MOISTURE ADVECTION AHEAD OF DEEPENING SFC LOWS OVER MANITOBA AND OVER MO/ILL SHOULD RESULT IN SHIELD OF RAIN LIFTING ACROSS WESTERN GREAT LAKES. BULK OF RAIN WILL HOLD OFF TIL AFTER MIDNIGHT TO MOVE INTO CWA. SUPPOSE ESE WINDS AND INCREASING MOISTURE MAY ALLOW FOR A FEW SHOWERS TO FORM AS EARLY AS EVENING OVER UPSLOPE OF CENTRAL UPR MICHIGAN. PRETTY LOW CHANCE. RAIN SPREADS OVER ALL CWA BY DAYBREAK WED. RAIN SHOULD CONTINUE MUCH OF WED AS LARGE SCALE FORCING ONLY INCREASES DUE TO PHASING OF CANADIAN SHORTWAVE TROUGH AND SOUTHERN SHORTWAVE TROUGH LIFTING FM THE PLAINS TO THE OHIO VALLEY. SFC LOW OVER MO/ILL BECOMES MAIN PLAYER...DEEPENING TO 990-995MB WHILE REACHING SOMEWHERE VCNTY OF UPR MICHIGAN BY MIDDAY WED AND TO AROUND 985MB AS IT MOVES OVER LK SUPERIOR BY 00Z THU. DESPITE LOW CROSSING THE CWA ON WED...FORCING AND DEEP MOISTURE VIA THE SOUTHERN SHORTWAVE TROUGH APPEAR TO KEEP DRY SLOT AFFECTS TO A MINIMUM. TOTAL RAINFALL OF AT LEAST ONE QUARTER IF NOT ONE HALF INCH SHOULD RESULT FM THE SYSTEM...BUT GIVEN ALL THE INTERACTIONS THAT ARE FORECAST TO OCCUR ALOFT...SPECIFICS IN RAIN TIMING/EXTENT AND AMOUNTS MAY STILL CHANGE. ONCE THE LOW MOVES NORTH OF LK SUPERIOR TOWARD JAMES BAY WEDNESDAY NIGHT...COOLER AIR BEGINS TO WORK ACROSS UPPER GREAT LAKES. PROGS OF H85 TEMPS AND 1000- 850MB THICKNESSES FM GFS/ECMWF POINT TO COOLEST AIR STAYING OVER MN AND WI WHILE OCCLUDING LOW PRESSURE SYSTEM RESULTS IN SLIGHTLY WARMER AIR OVER UPR MICHIGAN. H85 TEMPS AT 12Z THU ARE -2C OVER LK SUPERIOR AND ONLY FALL TO AROUND -4C BY 00Z. LK SUPERIOR TEMPS ARE 8- 10C...SO PROBABLY JUST ENOUGH OVER-WATER INSTABILITY TO RESULT IN LAKE EFFECT PRECIPITATION...ESPECIALLY WITH CYCLONIC LOW-LEVEL FLOW AND WRAP AROUND MOISTURE. MIX OF RAIN/SNOW WOULD BE MOST FAVORED OVER HIGHER TERRAIN OF WESTERN UPR MICHIGAN LATE WED NIGHT INTO THU MORNING. NW WINDS WILL BE BREEZY NEAR LK SUPERIOR ON THU. HIGH TEMPERATURES ON THU LIKELY WILL STRUGGLE TO REACH 40 DEGREES OVER HIGHER TERRAIN OF WEST AND NCNTRL UPR MICHIGAN. UPPER LEVEL TROUGH BECOMES MORE PROGRESSIVE THURSDAY NIGHT INTO FRIDAY. H85 TEMPS FALL TO -6C TO -8C BY 12Z FRIDAY BUT WITH LESS CYCLONIC FLOW LOOKING AT PURE LAKE EFFECT BY THAT TIME. GFS IS COLDER AND WOULD POINT TO SMALL CHANCES FOR LAKE EFFECT ESPECIALLY NCNTRL AND EAST NEAR LK SUPERIOR INTO FRIDAY. FLOW ALOFT CONTINUES TO FLATTEN OUT FRIDAY INTO SATURDAY. GFS MORE AGGRESSIVE THAN ECMWF OR GEM IN BRINGING QPF INTO UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES BY SATURDAY. USED CONSENSUS WHICH ONLY HAS SMALL CHANCES. TEMPS SHOULD WARM TO AROUND NORMAL FOR THE LAST DAY OF OCTOBER. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 731 AM EDT SUN OCT 25 2015 EXPECT A PERIOD OF MVFR CIGS THIS MORNING AS A LOW PRES TROUGH OR WEAK COLD FRONT MOVES THROUGH THE AREA. ALTHOUGH CONDITIONS ARE LIKELY TO IMPROVE INTO THE VFR RANGE BY LATE MORNING AT IWD/CMX AND AT SAW THIS EVENING FOLLOWING THE TROF PASSAGE...ANOTHER DISTURBANCE MOVING TOWARD WI AND ALONG THE STALLED LOW PRES TROUGH MAY BRING SOME MVFR CIGS AGAIN TO IWD AND SAW BY LATE TONIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 508 AM EDT SUN OCT 25 2015 WINDS WILL DIMINISH TODAY AS HIGH PRESSURE BEGINS TO BUILD BACK OVER THE REGION. WINDS ARE EXPECTED TO REMAIN AOB 25 KTS INTO TUESDAY...BUT WILL INCREASE BY WEDNESDAY AS A LOW PRESSURE SYSTEM CROSSES THE UPPER GREAT LAKES. NW WINDS IN WAKE OF THE LOW ARE EXPECTED TO REACH NEAR OR JUST ABOVE GALE FORCE OVER PORTIONS CENTRAL AND EASTERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
509 AM EDT SUN OCT 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 508 AM EDT SUN OCT 25 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH FROM HUDSON BAY INTO THE GREAT LAKES RESULTING IN WNW FLOW FROM SRN SASK/ALBERTA AND THE NRN PLAINS INTO THE WRN LAKES. A WEAK SHRTWV INTO LAKE SUPERIOR SUPPORTED AN AREA OF CLOUDS AND SOME ISOLATED LIGHT SHOWERS OR SPRINKLES OVER CNTRL/ERN LAKE SUPERIOR AND INTO N CNTRL UPPER MI. FARTHER UPSTREAM...A COUPLE OF SHORTWAVES OVER ALBERTA WILL INFLUENCE THE WEATHER TONIGHT. AT THE SFC...NW WINDS WERE DIMINISHING AS HIGH PRES OVER THE UPPER MS VALLEY BUILDS INTO THE REGION. TODAY...THE POTENTIAL REMAINS FOR A FEW LIGHT SHOWERS OR SPRINKLE OVER THE ERN CWA THROUGH THIS MORNING AS ANOTHER WEAK SHRTWV BRUSHES THE AREA. OTHERWISE...UNDER PARTLY TO MOSTLY CLOUDY SKIES TEMPS WILL REMAIN NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES WITH HIGHS IN THE MID 40S NORTH AND AROUND 50 SOUTH. TONIGHT...AS THE ALBERTA SHRTWVS NEAR THE REGION PCPN ASSOCIATED WITH A BAND OF 850-600 MB FGEN WILL DEVELOP. THE GFS/NAM/ECMWF AND HIGH RES MODELS REMAINED REASONABLY CONSISTENT IN KEEPING THE GREATEST PCPN AMOUNTS MAINLY THROUGH SRN UPPER MI NEAR THE WI BORDER. HOWEVER...SOME UNCERTAINTY REMAINS WITH THE POSITION OF THE BAND AS THE GEM PRODUCES PCPN ACROSS MOST OF UPPER MICHIGAN. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 508 AM EDT SUN OCT 25 2015 ...ACTIVE WEATHER WEEK EXPECTED... ACTIVE WEEK OF WEATHER IN STRORE WITH BEST CHANCE OF WIDESPREAD RAIN LATE TUESDAY NIGHT INTO WEDNESDAY AS DEEPENING LOW PRESSURE SYSTEM LIFTS THROUGH THE UPPER GREAT LAKES REGION. ENOUGH COOL AIR ON BACK SIDE OF THE SYSTEM TO HAVE SOME SNOW IN THE FORECAST LATE WEDNESDAY NIGHT INTO THURSDAY. SLIGHTLY WARMER CONDITIONS WILL RETURN BY NEXT WEEKEND. OUTLOOKS FM CPC INDICATE ABOVE NORMAL CONDITIONS COULD PERSIST INTO MUCH OF NOVEMBER AS STRONG EL NINO CONTINUES TO INFLUENCE THE OVERALL LARGER SCALE WEATHER PATTERN. STARTING OFF THE LONG TERM SHORTWAVE WILL BE DROPPING OVER NORTHERN MN INTO LK SUPERIOR BEFORE RIDGING BUILDS IN LATER MONDAY INTO MONDAY NIGHT. SFC TROUGH THAT MOVES THROUGH TODAY SHOULD BE SOUTH OF UPR MICHIGAN ON MONDAY BUT THE SHORTWAVE ALONG WITH RIBBON OF H85-H7 FRONTOGENESIS NORTH OF THE SFC TROUGH RESULTS IN WIDESPREAD BUT LIGHT RAIN OVER AT LEAST SOUTH HALF OF CWA. LIGHT RAIN MAY LIFT NORTH SLIGHTLY ON MONDAY AS THE SHORTWAVE BEGINS TO EXIT TO THE NORTHEAST. APPEARS KEWEENAW MISSES OUT ON MOST OF THE RAIN WITH THIS SYSTEM...THROUGH FARTHER NORTH GEM-REGIONAL WOULD BRING SOME RAIN UP TO HOUGHTON/HANCOCK. DECAYING RIBBON OF MOISTURE LINGERS INTO MONDAY EVENING...THOUGH EXACTLY WHERE IS NOT CERTAIN. SLIGHT CHANCES FOR CNTRL IN CASE A FEW SHOWERS OR SPRINKLES PERSIST. ATTN TUESDAY INTO TUESDAY NIGHT TURNS TO DEEPENING TROUGH FM CANADIAN PRAIRIES INTO THE CNTRL CONUS. COMPLICATED INTERACTION OF MULTIPLE SHORTWAVES AND ALSO REMNANTS OF HURRICANE PATRICIA OVER SCNTRL CONUS WILL CAUSE THE TROUGH TO DEEPEN. AT THE SFC...HIGH PRESSURE RIDGE WILL BUILD OVER THE LOWER GREAT LAKES TO THE MID ATLANTIC COAST WHILE LOW PRESSURE TROUGH DEVELOPS OVER THE CNTRL CONUS. WARM AIR ADVECTION ALOFT SHOULD BE OFFSET BY DRY LOW-LEVELS DUE TO HIGH IN THE VCNTY TO PROHIBIT MUCH RAIN ON TUESDAY. MOISTURE ADVECTION IN LOW-LEVELS FOCUSES OVER WEST LK SUPERIOR AND OVER MN SO THAT IS WHERE LOW POPS WILL RESIDE ON TUESDAY. SHOULD BE PLENTY OF MID-HIGH CLOUDS AROUND THOUGH. ON TUESDAY NIGHT...ONE PART OF UPPER LEVEL TROUGH DEEPENS AND MOVES OVER CNTRL PLAINS WHILE STRONGER SHORTWAVE TROUGH DIGS SOUTHEAST OVER SASKATCHEWAN AND MANITOBA. DEEP LAYER Q-VECTOR CONVERGENCE AND MOISTURE ADVECTION AHEAD OF DEEPENING SFC LOWS OVER MANITOBA AND OVER MO/ILL SHOULD RESULT IN SHIELD OF RAIN LIFTING ACROSS WESTERN GREAT LAKES. BULK OF RAIN WILL HOLD OFF TIL AFTER MIDNIGHT TO MOVE INTO CWA. SUPPOSE ESE WINDS AND INCREASING MOISTURE MAY ALLOW FOR A FEW SHOWERS TO FORM AS EARLY AS EVENING OVER UPSLOPE OF CENTRAL UPR MICHIGAN. PRETTY LOW CHANCE. RAIN SPREADS OVER ALL CWA BY DAYBREAK WED. RAIN SHOULD CONTINUE MUCH OF WED AS LARGE SCALE FORCING ONLY INCREASES DUE TO PHASING OF CANADIAN SHORTWAVE TROUGH AND SOUTHERN SHORTWAVE TROUGH LIFTING FM THE PLAINS TO THE OHIO VALLEY. SFC LOW OVER MO/ILL BECOMES MAIN PLAYER...DEEPENING TO 990-995MB WHILE REACHING SOMEWHERE VCNTY OF UPR MICHIGAN BY MIDDAY WED AND TO AROUND 985MB AS IT MOVES OVER LK SUPERIOR BY 00Z THU. DESPITE LOW CROSSING THE CWA ON WED...FORCING AND DEEP MOISTURE VIA THE SOUTHERN SHORTWAVE TROUGH APPEAR TO KEEP DRY SLOT AFFECTS TO A MINIMUM. TOTAL RAINFALL OF AT LEAST ONE QUARTER IF NOT ONE HALF INCH SHOULD RESULT FM THE SYSTEM...BUT GIVEN ALL THE INTERACTIONS THAT ARE FORECAST TO OCCUR ALOFT...SPECIFICS IN RAIN TIMING/EXTENT AND AMOUNTS MAY STILL CHANGE. ONCE THE LOW MOVES NORTH OF LK SUPERIOR TOWARD JAMES BAY WEDNESDAY NIGHT...COOLER AIR BEGINS TO WORK ACROSS UPPER GREAT LAKES. PROGS OF H85 TEMPS AND 1000- 850MB THICKNESSES FM GFS/ECMWF POINT TO COOLEST AIR STAYING OVER MN AND WI WHILE OCCLUDING LOW PRESSURE SYSTEM RESULTS IN SLIGHTLY WARMER AIR OVER UPR MICHIGAN. H85 TEMPS AT 12Z THU ARE -2C OVER LK SUPERIOR AND ONLY FALL TO AROUND -4C BY 00Z. LK SUPERIOR TEMPS ARE 8- 10C...SO PROBABLY JUST ENOUGH OVER-WATER INSTABILITY TO RESULT IN LAKE EFFECT PRECIPITATION...ESPECIALLY WITH CYCLONIC LOW-LEVEL FLOW AND WRAP AROUND MOISTURE. MIX OF RAIN/SNOW WOULD BE MOST FAVORED OVER HIGHER TERRAIN OF WESTERN UPR MICHIGAN LATE WED NIGHT INTO THU MORNING. NW WINDS WILL BE BREEZY NEAR LK SUPERIOR ON THU. HIGH TEMPERATURES ON THU LIKELY WILL STRUGGLE TO REACH 40 DEGREES OVER HIGHER TERRAIN OF WEST AND NCNTRL UPR MICHIGAN. UPPER LEVEL TROUGH BECOMES MORE PROGRESSIVE THURSDAY NIGHT INTO FRIDAY. H85 TEMPS FALL TO -6C TO -8C BY 12Z FRIDAY BUT WITH LESS CYCLONIC FLOW LOOKING AT PURE LAKE EFFECT BY THAT TIME. GFS IS COLDER AND WOULD POINT TO SMALL CHANCES FOR LAKE EFFECT ESPECIALLY NCNTRL AND EAST NEAR LK SUPERIOR INTO FRIDAY. FLOW ALOFT CONTINUES TO FLATTEN OUT FRIDAY INTO SATURDAY. GFS MORE AGGRESSIVE THAN ECMWF OR GEM IN BRINGING QPF INTO UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES BY SATURDAY. USED CONSENSUS WHICH ONLY HAS SMALL CHANCES. TEMPS SHOULD WARM TO AROUND NORMAL FOR THE LAST DAY OF OCTOBER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 126 AM EDT SUN OCT 25 2015 EXPECT VFR CONDITIONS TO GIVE WAY TO A PERIOD OF MVFR CIGS AT CMX AND SAW EARLY IN THE MRNG AS A LO PRES TROF APRCHG FM THE NW CROSSES LK SUP. ALTHOUGH CONDITIONS ARE LIKELY TO IMPROVE INTO THE VFR RANGE IN THE AFTN AT THESE LOCATIONS FOLLOWING THE TROF PASSAGE...ANOTHER DISTURBANCE MOVING TOWARD WI AND ALONG THE STALLED LO PRES TROF MAY BRING SOME MVFR CIGS AGAIN TO IWD AND PERHAPS SAW THIS EVNG. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 508 AM EDT SUN OCT 25 2015 WINDS WILL DIMINISH TODAY AS HIGH PRESSURE BEGINS TO BUILD BACK OVER THE REGION. WINDS ARE EXPECTED TO REMAIN AOB 25 KTS INTO TUESDAY...BUT WILL INCREASE BY WEDNESDAY AS A LOW PRESSURE SYSTEM CROSSES THE UPPER GREAT LAKES. NW WINDS IN WAKE OF THE LOW ARE EXPECTED TO REACH NEAR OR JUST ABOVE GALE FORCE OVER PORTIONS CENTRAL AND EASTERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
327 AM EDT SUN OCT 25 2015 .SYNOPSIS... A WARM FRONT WILL PUSH THROUGH THE REGION TONIGHT, FOLLOWED BY A COLD FRONT ON SUNDAY. THE COMBINATION OF THESE SYSTEMS WILL BRING SCATTERED TO NUMEROUS SHOWERS TO THE REGION TONIGHT AND INTO THE MORNING HOURS ON SUNDAY. BEHIND THIS SYSTEM A RETURN TO DRIER WEATHER IS EXPECTED MONDAY INTO TUESDAY BEFORE A STRONGER SYSTEM AND ASSOCIATED RAINFALL AFFECTS THE REGION BY MID-WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1253 AM EDT SUNDAY...A WIND ADVISORY REMAINS IN EFFECT THROUGH 6 AM FOR THE CHAMPLAIN VALLEY DUE TO STRONG GUSTY SOUTHERLY WINDS FROM 20-30 MPH WITH GUSTS UP TO 45-50 MPH. REPORTS OF ADVISORY CRITERIA HAVE ALREADY BEEN MET IN THE CHAMPLAIN VALLEY WITH WHITE`S BEACH ON GRAND ISLE GUSTING TO 49MPH AND COLCHESTER REEF GUSTING TO 53 MPH. I CONTINUED THE MENTION OF ISOLATED CHANCES FOR THUNDER AS THE FRONT MOVES INTO THE SAINT LAWRENCE VALLEY FOR THE VALLEY AND THE WESTERN ADIRONDACKS. I BUMPED UP THE PRECIP CHANCES TO REFLECT OBS AND THE HRRR GUIDANCE. OTHERWISE THE INHERITED FORECAST HAS THE TIMING AND INTENSITY WELL COVERED WITH NO CHANGES NEEDED. PREVIOUS DISCUSSION FROM 708 PM SATURDAY... ONLY RELATIVELY MINOR CHANGES TO REFLECT CURRENT TRENDS/OBSERVATIONS. TEMPERATURES HAVE DROPPED A LITTLE MORE THAN PREVIOUS FORECAST SO HAVE WORKED THAT IN...ALTHOUGH A LEVELING OUT AND EVEN A GRADUAL RISE IS STILL EXPECTED THROUGH THE OVERNIGHT HOURS AS MOISTURE/SOUTHERLY FLOW INCREASE OUT AHEAD OF APPROACHING FRONTAL SYSTEM. FOR WINDS...HAVE ALREADY SEEN SOME WIND GUSTS OVER AND IMMEDIATELY NEAR LAKE CHAMPLAIN IN THE 40-50 MPH RANGE...AND 25-40 MPH RANGE ACROSS THE REMAINDER OF THE NORTHERN CHAMPLAIN VALLEY. WIND GUSTS OVERNIGHT STILL ON TRACK FOR LOW-END ADVISORY CRITERIA IN THE IMMEDIATE CHAMPLAIN VALLEY. STRENGTHENING LOW LEVEL WIND FIELD AND FORCED SOUTHERLY CHANNELING WILL BE PRESENT...THE QUESTION IS HOW THE STABILITY EVOLVES OVERNIGHT. FORECAST SHOWS A CONTINUATION OF CURRENT OBSERVED GUSTS WITH STRONGEST WINDS EXPECTED TO BE RIGHT OVER AND NEAR THE LAKE WITH WARMER LAKE WATERS...WHERE 40-50 MPH GUSTS IN FORECAST. ELSEWHERE IN THE NORTHERN CHAMPLAIN VALLEY 30-40 MPH LOOKS GOOD. OUTSIDE OF THESE LOCATIONS...ALL GUSTS WILL BE LESS THAN 30 MPH EXCEPT FOR THE HIGHEST ELEVATIONS. SCATTERED RAIN SHOWERS WILL CONTINUE TO INCREASE IN COVERAGE OVERNIGHT...WITH GREATEST CONCENTRATION 04Z-10Z. RAINFALL AMOUNTS WILL HAVE SOME TERRAIN-DRIVEN COMPONENTS...WITH THE LEAST IN THE DOWNSLOPE REGIONS OF THE CHAMPLAIN VALLEY (AROUND 0.10")...AND GREATEST IN THE HIGHER TERRAIN OF THE ADIRONDACKS/GREENS WITH UP TO ABOUT A THIRD OF AN INCH. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... AS OF 315 PM EDT SATURDAY...THE FORECAST AREA WILL THEN LIE IN A NARROW WARM SECTOR OF PARENT CENTRAL CANADIAN SYSTEM BY SUNDAY MORNING AS GUSTY SOUTHERLY FLOW GRADUALLY ABATES AND VEERS TO WEST/SOUTHWESTERLY AHEAD OF A COLD FRONT MARCHING STEADILY EASTWARD. WITH THE BEST FORCING AND DEEPER MOISTURE HAVING PUSHED OFF TO THE EAST, ONLY EXPECTING A FEW ADDITIONAL MORNING SHOWERS ALONG THE BOUNDARY WITH MOST OF THE DAY GENERALLY DRY DESPITE DEVELOPMENT OF COLD AIR POST- FRONTAL STRATOCUMULUS CLOUDS. MAXIMUM TEMPERATURES (50S) SHOULD OCCUR BY LATE MORNING TO AROUND NOON AHEAD OF THE FRONT BEFORE READINGS LEVEL OFF, OR EVEN FALL ACROSS THE HIGHER ELEVATIONS DURING THE AFTERNOON. THE REMAINDER OF THE SHORT TERM FORECAST IS ESSENTIALLY COOL AND QUIET FOR SUNDAY NIGHT INTO MONDAY AS EXPANSIVE SURFACE RIDGE BUILDS BODILY EASTWARD INTO THE NORTHEAST. ALONG WITH CLEAR TO PARTLY CLOUDY SKIES DRY WEATHER IS EXPECTED AS TEMPERATURES AVERAGE A FEW DEGREES BELOW LATE OCTOBER NORMS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 326 AM EDT SUNDAY...CONDITIONS BEGIN TRANQUIL TUESDAY NIGHT AS LARGE SFC ANTICYCLONE SLOWLY DEPARTS EWD THRU THE GULF OF MAINE. WILL PROBABLY SEE SOME LIGHT SELY WINDS DEVELOPING AFTER MIDNIGHT...ALONG WITH THE OVERSPREAD OF MID TO UPPER LEVEL CLOUDINESS FROM SW-NE TOWARD MORNING AHEAD OF WARM FRONT ACROSS THE OHIO VALLEY. GOOD RADIATIONAL COOLING EARLY TUESDAY NIGHT SHOULD ALLOW FOR LOWS IN THE MID 30S...EXCEPT UPR 20S TO LOWER 30S ACROSS VERMONT/S NORTHEAST KINGDOM OWING TO LATER ARRIVAL OF HIGH CLOUDINESS. 00Z GFS REMAINS SLIGHTLY FASTER THAN THE 00Z ECMWF...BUT GENERALLY IN BETTER AGREEMENT FOR WIDESPREAD PRECIPITATION EVENT UPCOMING FOR WEDNESDAY INTO THURSDAY. DEEP-LAYER SWLY FLOW IN ADVANCE OF SHORTWAVE TROUGH ACROSS THE SRN GREAT LAKES AND MID MS RIVER VALLEY WILL BRING FIRST WAVE OF ISENTROPIC ASCENT AND ONSET OF PRECIPITATION FROM SW-NE DURING THE DAYLIGHT HRS ON WEDNESDAY. THE 00Z GFS DEVELOPS STEADY/WAA ASSOCIATED PCPN ACROSS THE REGION BETWEEN 15-18Z WED...WHILE ECMWF IS MAINLY 18Z WED THRU 00Z THURSDAY. HAVE INDICATED LIKELY POPS WEDNESDAY (GENERALLY 65-75 PERCENT)...HIGHEST DURING THE AFTN HRS. WILL LIKELY SEE DEVELOPMENT OF SOME GUSTY WINDS AS WELL (S-SE 20-30 MPH)...WITH STRONG P- GRADIENT IN PLACE DURING THE DAY WEDNESDAY. HIGHS GENERALLY IN THE MID-UPR 50S...AND LIKELY ONLY FALLING TO AROUND 50F WEDNESDAY NIGHT WITH CONTINUED SLY GRADIENT FLOW. MAY SEE MID-LEVEL DRY SLOT EVOLVE OVER THE AREA WEDNESDAY NIGHT...BUT PERIODS OF RAIN WILL REMAIN POSSIBLE UNTIL THE COLD FRONT CLEARS THE AREA FROM WEST TO EAST...LIKELY DURING THE DAY THURSDAY. PW VALUES PEAK BETWEEN 1.25-1.5" DURING WEDNESDAY AFTN/EVENING PER 00Z GFS. ALONG WITH STRONG SYNOPTIC ASCENT...THIS SHOULD RESULT IN PERIODS OF MODERATE TO BRIEFLY HVY RAINFALL WED AFTN INTO WEDNESDAY NIGHT. OVERALL QPF GENERALLY 0.75-1" IN THE 00Z GFS...BUT 1-1.5" GENERALLY IN THE 00Z ECMWF. SHOULD BE A SIGNIFICANT RAINFALL...BUT OVERALL NOT ENOUGH TO RESULT IN HYDROLOGICAL CONCERNS. SHOULD SEE HIGH TEMPERATURES BRIEFLY REACH THE MID 60S ON THURSDAY BEFORE COLD FRONT CLEARS THE AREA. THEREAFTER...SOME LINGERING SHOWERS/MTN FLURRIES WILL BE POSSIBLE THURSDAY NIGHT INTO FRIDAY AS SOMEWHAT COLDER AIR MASS MOVES IN FROM THE WNW. HIGHS FRIDAY AND SATURDAY SHOULD BE IN THE MID-UPR 40S IN MOST SECTIONS...WITH GENERAL TREND TOWARD DRIER CONDITIONS. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...STRONG PRESSURE GRADIENT IN PLACE AHEAD OF COLD FRONT APPROACHING FROM THE ERN GREAT LAKES AND SERN ONTARIO. THIS IS RESULTING IN SOUTH WINDS 15-25KT...WITH GUSTS UP TO 35KT AT BTV. DOWNWARD MIXING IS LIMITED AT RUT/MPV/MSS WITH INVERSION LAYER IN PLACE...AND CARRIED LLWS GROUPS AT THESE SITES. ANTICIPATE AREAS OF TURBULENCE AT LOW LEVELS DURING NEXT SEVERAL HRS WITH 60KT LOW-LEVEL JET IN PLACE AT 2-3 KFT AGL THRU ABOUT 10Z. PERIODS OF SHOWERS ALSO EXPECTED THROUGH ABOUT 12Z...WITH CEILINGS LOWERING TO MVFR AT MOST TAF LOCATIONS. FROPA BRINGS WIND SHIFT TO THE WEST AND EVENTUALLY WEST-NORTHWEST LATE THIS MORNING INTO THIS AFTN...WITH WINDS DIMINISHING SLIGHTLY TO 10-15KT AND GUSTS 20-25 KTS. CEILINGS SLOWLY RETURN VFR BY 18Z THIS AFTN WITH DRYING BEHIND THE FRONT...AND GRADUAL CLEARING EXPECTED TOWARD EVENING. SFC WINDS SUBSIDE BELOW 10KTS AREAWIDE AFTER SUNSET. OUTLOOK 06Z MONDAY THROUGH THURSDAY... BUILDING AREA OF HIGH PRESSURE BRINGS VFR CONDITIONS FROM 06Z MONDAY THROUGH 12Z WEDNESDAY. NEXT SYSTEM WILL PRODUCE GUSTY SOUTH WINDS BY WEDNESDAY WITH MODERATE DEVELOPING AHEAD OF A WARM FRONT. PERIODS OF MVFR CIGS/VIS IN RAIN WILL BE POSSIBLE WEDNESDAY INTO THURSDAY MORNING. && .MARINE... AS OF 315 PM SATURDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT FOR TONIGHT INTO SUNDAY MORNING FOR STRONG AND CHANNELED SOUTHERLY WIND GUSTS FROM 28 TO 43 KNOTS. LATEST OBSERVATIONAL DATA INDICATE SOUTHERLY WINDS ALREADY GUSTING AS HIGH AS 40 KNOTS ACROSS PORTIONS OF THE OPEN LAKE WATERS AND EXPECT THIS TREND TO CONTINUE THIS EVENING AND INTO THE OVERNIGHT HOURS BEFORE CONDITIONS ABATE BY THE MID MORNING HOURS ON SUNDAY. THE BROAD LAKE WATERS AND BAYS/INLETS WITH OPEN SOUTHERLY EXPOSURES WILL BE MOST SUSCEPTIBLE TO THE STRONGER WINDS, WHICH MAY PRODUCE SIGNIFICANT WAVE HEIGHTS TO 5 FEET OR SLIGHTLY HIGHER THIS EVENING/TONIGHT. THESE CONDITIONS WILL POSE A SIGNIFICANT HAZARD TO SMALL CRAFT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WIND ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR VTZ001-002- 005. NY...WIND ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR NYZ028. && $$ SYNOPSIS...JMG NEAR TERM...JMG/DEAL/MUCCILLI SHORT TERM...JMG LONG TERM...BANACOS AVIATION...BANACOS MARINE...SISSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
135 AM EDT SUN OCT 25 2015 .SYNOPSIS... A WARM FRONT WILL PUSH THROUGH THE REGION TONIGHT, FOLLOWED BY A COLD FRONT ON SUNDAY. THE COMBINATION OF THESE SYSTEMS WILL BRING SCATTERED TO NUMEROUS SHOWERS TO THE REGION TONIGHT AND INTO THE MORNING HOURS ON SUNDAY. BEHIND THIS SYSTEM A RETURN TO DRIER WEATHER IS EXPECTED MONDAY INTO TUESDAY BEFORE A STRONGER SYSTEM AND ASSOCIATED RAINFALL AFFECTS THE REGION BY MID-WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1253 AM EDT SUNDAY...A WIND ADVISORY REMAINS IN EFFECT THROUGH 6 AM FOR THE CHAMPLAIN VALLEY DUE TO STRONG GUSTY SOUTHERLY WINDS FROM 20-30 MPH WITH GUSTS UP TO 45-50 MPH. REPORTS OF ADVISORY CRITERIA HAVE ALREADY BEEN MET IN THE CHAMPLAIN VALLEY WITH WHITE`S BEACH ON GRAND ISLE GUSTING TO 49MPH AND COLCHESTER REEF GUSTING TO 53 MPH. I CONTINUED THE MENTION OF ISOLATED CHANCES FOR THUNDER AS THE FRONT MOVES INTO THE SAINT LAWRENCE VALLEY FOR THE VALLEY AND THE WESTERN ADIRONDACKS. I BUMPED UP THE PRECIP CHANCES TO REFLECT OBS AND THE HRRR GUIDANCE. OTHERWISE THE INHERITED FORECAST HAS THE TIMING AND INTENSITY WELL COVERED WITH NO CHANGES NEEDED. PREVIOUS DISCUSSION FROM 708 PM SATURDAY... ONLY RELATIVELY MINOR CHANGES TO REFLECT CURRENT TRENDS/OBSERVATIONS. TEMPERATURES HAVE DROPPED A LITTLE MORE THAN PREVIOUS FORECAST SO HAVE WORKED THAT IN...ALTHOUGH A LEVELING OUT AND EVEN A GRADUAL RISE IS STILL EXPECTED THROUGH THE OVERNIGHT HOURS AS MOISTURE/SOUTHERLY FLOW INCREASE OUT AHEAD OF APPROACHING FRONTAL SYSTEM. FOR WINDS...HAVE ALREADY SEEN SOME WIND GUSTS OVER AND IMMEDIATELY NEAR LAKE CHAMPLAIN IN THE 40-50 MPH RANGE...AND 25-40 MPH RANGE ACROSS THE REMAINDER OF THE NORTHERN CHAMPLAIN VALLEY. WIND GUSTS OVERNIGHT STILL ON TRACK FOR LOW-END ADVISORY CRITERIA IN THE IMMEDIATE CHAMPLAIN VALLEY. STRENGTHENING LOW LEVEL WIND FIELD AND FORCED SOUTHERLY CHANNELING WILL BE PRESENT...THE QUESTION IS HOW THE STABILITY EVOLVES OVERNIGHT. FORECAST SHOWS A CONTINUATION OF CURRENT OBSERVED GUSTS WITH STRONGEST WINDS EXPECTED TO BE RIGHT OVER AND NEAR THE LAKE WITH WARMER LAKE WATERS...WHERE 40-50 MPH GUSTS IN FORECAST. ELSEWHERE IN THE NORTHERN CHAMPLAIN VALLEY 30-40 MPH LOOKS GOOD. OUTSIDE OF THESE LOCATIONS...ALL GUSTS WILL BE LESS THAN 30 MPH EXCEPT FOR THE HIGHEST ELEVATIONS. SCATTERED RAIN SHOWERS WILL CONTINUE TO INCREASE IN COVERAGE OVERNIGHT...WITH GREATEST CONCENTRATION 04Z-10Z. RAINFALL AMOUNTS WILL HAVE SOME TERRAIN-DRIVEN COMPONENTS...WITH THE LEAST IN THE DOWNSLOPE REGIONS OF THE CHAMPLAIN VALLEY (AROUND 0.10")...AND GREATEST IN THE HIGHER TERRAIN OF THE ADIRONDACKS/GREENS WITH UP TO ABOUT A THIRD OF AN INCH. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... AS OF 315 PM EDT SATURDAY...THE FORECAST AREA WILL THEN LIE IN A NARROW WARM SECTOR OF PARENT CENTRAL CANADIAN SYSTEM BY SUNDAY MORNING AS GUSTY SOUTHERLY FLOW GRADUALLY ABATES AND VEERS TO WEST/SOUTHWESTERLY AHEAD OF A COLD FRONT MARCHING STEADILY EASTWARD. WITH THE BEST FORCING AND DEEPER MOISTURE HAVING PUSHED OFF TO THE EAST, ONLY EXPECTING A FEW ADDITIONAL MORNING SHOWERS ALONG THE BOUNDARY WITH MOST OF THE DAY GENERALLY DRY DESPITE DEVELOPMENT OF COLD AIR POST- FRONTAL STRATOCUMULUS CLOUDS. MAXIMUM TEMPERATURES (50S) SHOULD OCCUR BY LATE MORNING TO AROUND NOON AHEAD OF THE FRONT BEFORE READINGS LEVEL OFF, OR EVEN FALL ACROSS THE HIGHER ELEVATIONS DURING THE AFTERNOON. THE REMAINDER OF THE SHORT TERM FORECAST IS ESSENTIALLY COOL AND QUIET FOR SUNDAY NIGHT INTO MONDAY AS EXPANSIVE SURFACE RIDGE BUILDS BODILY EASTWARD INTO THE NORTHEAST. ALONG WITH CLEAR TO PARTLY CLOUDY SKIES DRY WEATHER IS EXPECTED AS TEMPERATURES AVERAGE A FEW DEGREES BELOW LATE OCTOBER NORMS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 310 PM EDT SATURDAY...AN ACTIVE 4 THROUGH 7 DAY FORECAST EXPECTED WITH GUSTY WINDS AND A MODERATE RAINFALL EVENT LIKELY. THE PERIOD OF RAIN IS EXPECTED FROM LATE WEDNESDAY AFTERNOON INTO THURSDAY MORNING WITH WIDESPREAD AMOUNTS UP TO 1 INCH LIKELY. IN ADDITION GUSTY SOUTHERLY WINDS ARE LIKELY AHEAD OF THIS SYSTEM ON WEDNESDAY INTO WEDNESDAY EVENING...THEN SHIFTING TO THE SOUTHWEST AND WEST ON THURSDAY. MODELS IN EXCELLENT AGREEMENT SHOWING A DEEP FULL LATITUDE MID/UPPER LEVEL TROF DEVELOPING ACROSS THE CENTRAL PLAINS AND LIFTING THROUGH THE GREAT LAKES ON WEDS INTO THURSDAY. THE PRESSURE GRADIENT BETWEEN DEPARTING 1035MB HIGH PRESSURE AND DEVELOPING 996MB LOW PRESSURE OVER THE NORTHERN PLAINS WILL CREATE GUSTS SOUTHEAST DOWNSLOPE WINDS ON WEDS EVENING. GIVEN MIXING HEIGHTS AND PROGGED LOW LEVEL WIND FIELDS EXPECT GUSTS TO 40 MPH ALONG THE WESTERN SLOPES AND PARTS OF THE CHAMPLAIN VALLEY. BOTH GFS AND ECMWF SHOW NOSE OF 850MB JET OF 50 TO 60 KNOTS LIFTING ACROSS OUR REGION ALONG WITH RIGHT REAR QUADRANT OF 250 MB JET OVER EASTERN CANADA. THIS WILL SUPPORT DEEP SYNOPTIC LIFT WITH STRONG MOISTURE ADVECTION ACROSS THE EASTERN CONUS. PW`S SURGE TO 1.50" AHEAD OF THIS SYSTEM WHICH IS 2 TO 3 STD ABOVE NORMAL. THINKING A WIDESPREAD RAINFALL OF 0.75 TO 1.50 IS LIKELY WITH LOCALIZED HIGHER AMOUNTS IN THE FAVORABLE UPSLOPE REGIONS. SOME SHADOWING WILL BE POSSIBLE IN THE NORTHEAST KINGDOM AND PARTS OF THE CHAMPLAIN VALLEY. I HAVE MENTION HIGH LIKELY TO LOW CAT POPS FROM LATE WEDS INTO THURSDAY MORNING. WELL DEFINED MID/UPPER LEVEL DRY SLOT DEVELOPS BY 18Z THURSDAY...RESULTING IN STEADIER RAINS BECOMING MORE SHOWERY. AS POTENT SHORT WAVE ENERGY AND DEEPENING AREA OF LOW PRESSURE LIFTS INTO CENTRAL CANADA...STRONG LOW LEVEL COLD AIR ADVECTION WILL DEVELOP ON GUSTY WESTERLY WINDS. A FEW GUSTS TO 45 MPH ARE POSSIBLE IN THE SOUTHWEST TO NORTHEAST ALIGNED SAINT LAWRENCE VALLEY AND PARTS OF THE HIGHER TERRAIN. ANY PRECIPITATION ON THURSDAY NIGHT INTO FRIDAY WILL BECOME TERRAIN DRIVEN AND LIGHT. PROGGED 850 TEMPS SUPPORT NEARLY NORMAL HIGHS ON TUESDAY...BUT WARM BETWEEN 3 AND 5C ON WEDS SUPPORTING HIGHS IN THE 50S TO NEAR 60. THINKING EVEN WARMER TEMPS ARE POSSIBLE ON THURSDAY AHEAD OF THE BOUNDARY...BEFORE VALUES DROP BACK TO NEAR NORMAL BY FRIDAY. GIVEN THE WINDS AND PRECIP EXPECT ABOVE NORMAL OVERNIGHT LOWS...ESPECIALLY WEDS NIGHT WITH VALUES IN THE 40S TO MID 50S. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...STRONG PRESSURE GRADIENT IN PLACE AHEAD OF COLD FRONT APPROACHING FROM THE ERN GREAT LAKES AND SERN ONTARIO. THIS IS RESULTING IN SOUTH WINDS 15-25KT...WITH GUSTS UP TO 35KT AT BTV. DOWNWARD MIXING IS LIMITED AT RUT/MPV/MSS WITH INVERSION LAYER IN PLACE...AND CARRIED LLWS GROUPS AT THESE SITES. ANTICIPATE AREAS OF TURBULENCE AT LOW LEVELS DURING NEXT SEVERAL HRS WITH 60KT LOW-LEVEL JET IN PLACE AT 2-3 KFT AGL THRU ABOUT 10Z. PERIODS OF SHOWERS ALSO EXPECTED THROUGH ABOUT 12Z...WITH CEILINGS LOWERING TO MVFR AT MOST TAF LOCATIONS. FROPA BRINGS WIND SHIFT TO THE WEST AND EVENTUALLY WEST-NORTHWEST LATE THIS MORNING INTO THIS AFTN...WITH WINDS DIMINISHING SLIGHTLY TO 10-15KT AND GUSTS 20-25 KTS. CEILINGS SLOWLY RETURN VFR BY 18Z THIS AFTN WITH DRYING BEHIND THE FRONT...AND GRADUAL CLEARING EXPECTED TOWARD EVENING. SFC WINDS SUBSIDE BELOW 10KTS AREAWIDE AFTER SUNSET. OUTLOOK 06Z MONDAY THROUGH THURSDAY... BUILDING AREA OF HIGH PRESSURE BRINGS VFR CONDITIONS FROM 06Z MONDAY THROUGH 12Z WEDNESDAY. NEXT SYSTEM WILL PRODUCE GUSTY SOUTH WINDS BY WEDNESDAY WITH MODERATE DEVELOPING AHEAD OF A WARM FRONT. PERIODS OF MVFR CIGS/VIS IN RAIN WILL BE POSSIBLE WEDNESDAY INTO THURSDAY MORNING. && .MARINE... AS OF 315 PM SATURDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT FOR TONIGHT INTO SUNDAY MORNING FOR STRONG AND CHANNELED SOUTHERLY WIND GUSTS FROM 28 TO 43 KNOTS. LATEST OBSERVATIONAL DATA INDICATE SOUTHERLY WINDS ALREADY GUSTING AS HIGH AS 40 KNOTS ACROSS PORTIONS OF THE OPEN LAKE WATERS AND EXPECT THIS TREND TO CONTINUE THIS EVENING AND INTO THE OVERNIGHT HOURS BEFORE CONDITIONS ABATE BY THE MID MORNING HOURS ON SUNDAY. THE BROAD LAKE WATERS AND BAYS/INLETS WITH OPEN SOUTHERLY EXPOSURES WILL BE MOST SUSCEPTIBLE TO THE STRONGER WINDS, WHICH MAY PRODUCE SIGNIFICANT WAVE HEIGHTS TO 5 FEET OR SLIGHTLY HIGHER THIS EVENING/TONIGHT. THESE CONDITIONS WILL POSE A SIGNIFICANT HAZARD TO SMALL CRAFT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WIND ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR VTZ001-002- 005. NY...WIND ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR NYZ028. && $$ SYNOPSIS...JMG NEAR TERM...JMG/DEAL/MUCCILLI SHORT TERM...JMG LONG TERM...TABER AVIATION...BANACOS MARINE...SISSON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1236 PM CDT SUN OCT 25 2015 .UPDATE... ISSUED AT 1235 PM CDT SUN OCT 25 2015 THE FOG WAS LIFTING ACROSS NORTHERN NORTH DAKOTA...AND HAD LIFTED IN THE JAMES RIVER VALLEY. RADAR RETURNS CONTINUE FROM JUST NORTH OF DICKINSON TO JUST SOUTH OF JAMESTOWN. HAVE MAINTAINED SPRINKLES IN THE FORECAST SOUTH HALF. UPDATE ISSUED AT 940 AM CDT SUN OCT 25 2015 VERY WEAK RADAR RETURNS CONTINUE FROM JUST SOUTHEAST OF GLASGOW MONTANA THO JUST SOUTH OF BISMARCK...PUSHING EAST. OTHER RETURNS WERE COMING FROM BOWMAN AND ADAMS COUNTIES. WHEN THESE RETURNS MOVED OVER KDIK AND KHEI NO PRECIPITATION WAS REPORTED AT THE SURFACE. WITH THAT...HAVE DROPPED ALL POPS AND ADDED SPRINKLES TO THE FORECAST FOR THE SOUTHERN PART OF THE FORECAST AREA. WILL EXPECT NOTHING MORE THAN A SPRINKLE...NOT ENOUGH TO WET THE GROUND...A TRACE...THE REST OF THE DAY. OTHER CONCERN IS PATCHY FOG PARTS OF THE NORTH AND JAMES RIVER VALLEY. MINOT IS A TROUBLE SPOT WITH 1/4 MILE VISIBILITY. AREA WEB CAMS SHOW FOG AT MINOT...THE AFB...CARPIO AND WHITE SHIELD...THROUGH GARRISON AND ON OVER TOWARD NEW ROCKFORD. WILL KEEP PATCHY FOG IN THE FORECAST THE REST OF THE MORNING AND EXPECT CLEARING AS WIND STIRS UP AND DEWPOINT DEPRESSION INCREASES. UPDATE ISSUED AT 638 AM CDT SUN OCT 25 2015 PATCHY FOG HAD DEVELOPED OVER PORTIONS OF CENTRAL NORTH DAKOTA. THE LATEST ITERATIONS OF THE HRRR WERE CONSISTENT WITH EARLIER RUNS WITH FOG FORMATION MOST LIKELY IN SOUTHERN MANITOBA...SOUTHEASTERN SASKATCHEWAN...INTO NORTH CENTRAL AND PARTS OF EASTERN NORTH DAKOTA. SOME FOG EVIDENT ON SATELLITE PICS IN THOSE AREAS...AS WELL AS SOME OBSERVATION STATIONS. GROUND FOG NOTED HERE IN THE BISMARCK AREA. THUS THINK PREVIOUS FORECAST PACKAGE WITH MENTION OF PATCHY FOG HAS ADDRESSED THIS WELL. OVER SOUTHWESTERN NORTH DAKOTA...LIGHT RADAR RETURNS SUGGEST EITHER SPRINKLES OR PERHAPS JUST VIRGA MOVING EASTWARD IN ASSOCIATION WITH A WEAK UPPER LEVEL IMPULSE MOVING EASTWARD OUT OF EASTERN MONTANA. HAVE KEPT THE MENTION OF MORNING LIGHT RAIN OR LIGHT SNOW. CURRENT FORECAST ON TRACK AND ONLY MINOR ADJUSTMENTS MADE IN HOURLY TEMPERATURES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN OCT 25 2015 FOG IS DEVELOPING IN NORTHERN AREAS AND IS EXPECTED TO LINGER IN THE JAMES RIVER VALLEY THROUGH LATE MORNING...SUPPORTED WELL WITHIN THE CURRENT RAP/HRRR MODEL RUNS. LOW STRATUS DEVELOPMENT IS ALSO POSSIBLE. LIGHT RAIN OVER THE SOUTHEAST WAS CONTINUING TO SLOWLY MOVE EASTWARD OUT OF THE STATE. MEANWHILE...A WEAK SHORT WAVE EMBEDDED WITHIN NORTHWEST FLOW ALOFT IS RESULTING IN LIGHT RAIN IN EASTERN MONTANA. PRECIPITATION IS EXPECTED TO CONTINUE EASTWARD INTO WESTERN NORTH DAKOTA BY 13Z...A WINTRY MIX AND/OR A FEW FLAKES OF SNOW MAY BE POSSIBLE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN OCT 25 2015 THE MAIN FOCUS FOR THE LONG TERM CONTINUES TO BE RAIN/SNOW CHANCES MONDAY THROUGH WEDNESDAY...WITH WIDESPREAD PRECIPITATION EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT. A LONGWAVE TROUGH EXTENDING FROM THE PACIFIC NORTHWEST TO THE 4- CORNERS ON MONDAY MORNING IS PROGGED TO MOVE EAST ACROSS THE ROCKIES MONDAY...DEEPENING AND EMERGING IN THE WESTERN PLAINS MONDAY NIGHT...AND MOVE EASTWARD SLOWLY ACROSS THE PLAINS INTO THE MISSISSIPPI VALLEY TUESDAY NIGHT. ANOTHER UPPER LEVEL SHORTWAVE ORIGINATING OVER THE CANADIAN ROCKIES FOLLOWS THE MAIN UPPER LONGWAVE AND DIVES SOUTHEAST ACROSS SASKATCHEWAN/MANITOBA INTO THE DAKOTAS AND MINNESOTA ON WEDNESDAY...MERGING WITH THE LONGWAVE TROUGH. THIS WILL BRING COLDER AIR SOUTHWARD INTO THE DAKOTAS TUESDAY NIGHT/WEDNESDAY. PRECIPITATION SHOULD BEGIN ACROSS SOUTHWEST NORTH DAKOTA MONDAY MORNING WITH THE LEADING EDGE OF UPSTREAM UPPER LEVEL ENERGY REACHING THE WESTERN DAKOTAS. MONDAY NIGHT THE AREA OF PRECIPITATION SHOULD SPREAD NORTH AND EAST ACROSS THE STATE AS THE UPPER TROUGH APPROACHES THE WESTERN DAKOTAS...ACCOMPANIED BY STRONG VORT ENERGY IMPULSES AND PLENTY OF MOISTURE ASSOCIATED WITH THE SYSTEM. PRECIPITATION SHOULD BE MAINLY IN THE FORM OF RAIN THROUGH TUESDAY AFTERNOON. AS THE SECOND COLDER SHORTWAVE MOVES SOUTHEAST FROM CANADA TUESDAY NIGHT...THE CHANCES OF RAIN BECOME CHANCES OF LIGHT SNOW FROM NORTHWEST TO SOUTHEAST. SOME AREAS ALONG THE NORTHERN TIER OF COUNTIES MAY SEE SOME LIGHT SNOW ACCUMULATIONS BY WEDNESDAY MORNING. HIGHS WEDNESDAY AND THURSDAY SHOULD BE IN THE 40S ACROSS NORTH DAKOTA WITH LOWS WEDNESDAY NIGHT AND THURSDAY NIGHT IN THE 20S. ANOTHER LONGWAVE TROUGH IS FORECAST TO MOVE INTO THE WEST COAST AND ROCKIES WEDNESDAY...WITH THE MODELS DEVELOPING A CUTOFF LOW OVER THE FAR SOUTHWEST AND ONLY A WEAK UPPER TROUGH MOVING EASTWARD ACROSS THE DAKOTAS FRIDAY. MODEL CONSENSUS KEEPS OUR AREA ON THE DRY SIDE WEDNESDAY NIGHT INTO NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 1235 PM CDT SUN OCT 25 2015 FOG AND LOW STRATUS LIFR OVER PARTS OF NORTHERN...KMOT...NORTH DAKOTA WAS LIFTING AT OF 17Z. OTHERWISE VFR WITH A BRIEF SPRINKLE OF LIGHT RAIN POSSIBLE KDIK-KBIS-KJMS THROUGH THE DAYLIGHT OF SUNDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JPM SHORT TERM...AC LONG TERM...JV AVIATION...JPM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
941 AM CDT SUN OCT 25 2015 .UPDATE... ISSUED AT 940 AM CDT SUN OCT 25 2015 VERY WEAK RADAR RETURNS CONTINUE FROM JUST SOUTHEAST OF GLASGOW MONTANA THO JUST SOUTH OF BISMARCK...PUSHING EAST. OTHER RETURNS WERE COMING FROM BOWMAN AND ADAMS COUNTIES. WHEN THESE RETURNS MOVED OVER KDIK AND KHEI NO PRECIPITATION WAS REPORTED AT THE SURFACE. WITH THAT...HAVE DROPPED ALL POPS AND ADDED SPRINKLES TO THE FORECAST FOR THE SOUTHERN PART OF THE FORECAST AREA. WILL EXPECT NOTHING MORE THAN A SPRINKLE...NOT ENOUGH TO WET THE GROUND...A TRACE...THE REST OF THE DAY. OTHER CONCERN IS PATCHY FOG PARTS OF THE NORTH AND JAMES RIVER VALLEY. MINOT IS A TROUBLE SPOT WITH 1/4 MILE VISIBILITY. AREA WEB CAMS SHOW FOG AT MINOT...THE AFB...CARPIO AND WHITE SHIELD...THROUGH GARRISON AND ON OVER TOWARD NEW ROCKFORD. WILL KEEP PATCHY FOG IN THE FORECAST THE REST OF THE MORNING AND EXPECT CLEARING AS WIND STIRS UP AND DEWPOINT DEPRESSION INCREASES. UPDATE ISSUED AT 638 AM CDT SUN OCT 25 2015 PATCHY FOG HAD DEVELOPED OVER PORTIONS OF CENTRAL NORTH DAKOTA. THE LATEST ITERATIONS OF THE HRRR WERE CONSISTENT WITH EARLIER RUNS WITH FOG FORMATION MOST LIKELY IN SOUTHERN MANITOBA...SOUTHEASTERN SASKATCHEWAN...INTO NORTH CENTRAL AND PARTS OF EASTERN NORTH DAKOTA. SOME FOG EVIDENT ON SATELLITE PICS IN THOSE AREAS...AS WELL AS SOME OBSERVATION STATIONS. GROUND FOG NOTED HERE IN THE BISMARCK AREA. THUS THINK PREVIOUS FORECAST PACKAGE WITH MENTION OF PATCHY FOG HAS ADDRESSED THIS WELL. OVER SOUTHWESTERN NORTH DAKOTA...LIGHT RADAR RETURNS SUGGEST EITHER SPRINKLES OR PERHAPS JUST VIRGA MOVING EASTWARD IN ASSOCIATION WITH A WEAK UPPER LEVEL IMPULSE MOVING EASTWARD OUT OF EASTERN MONTANA. HAVE KEPT THE MENTION OF MORNING LIGHT RAIN OR LIGHT SNOW. CURRENT FORECAST ON TRACK AND ONLY MINOR ADJUSTMENTS MADE IN HOURLY TEMPERATURES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN OCT 25 2015 FOG IS DEVELOPING IN NORTHERN AREAS AND IS EXPECTED TO LINGER IN THE JAMES RIVER VALLEY THROUGH LATE MORNING...SUPPORTED WELL WITHIN THE CURRENT RAP/HRRR MODEL RUNS. LOW STRATUS DEVELOPMENT IS ALSO POSSIBLE. LIGHT RAIN OVER THE SOUTHEAST WAS CONTINUING TO SLOWLY MOVE EASTWARD OUT OF THE STATE. MEANWHILE...A WEAK SHORT WAVE EMBEDDED WITHIN NORTHWEST FLOW ALOFT IS RESULTING IN LIGHT RAIN IN EASTERN MONTANA. PRECIPITATION IS EXPECTED TO CONTINUE EASTWARD INTO WESTERN NORTH DAKOTA BY 13Z...A WINTRY MIX AND/OR A FEW FLAKES OF SNOW MAY BE POSSIBLE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN OCT 25 2015 THE MAIN FOCUS FOR THE LONG TERM CONTINUES TO BE RAIN/SNOW CHANCES MONDAY THROUGH WEDNESDAY...WITH WIDESPREAD PRECIPITATION EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT. A LONGWAVE TROUGH EXTENDING FROM THE PACIFIC NORTHWEST TO THE 4- CORNERS ON MONDAY MORNING IS PROGGED TO MOVE EAST ACROSS THE ROCKIES MONDAY...DEEPENING AND EMERGING IN THE WESTERN PLAINS MONDAY NIGHT...AND MOVE EASTWARD SLOWLY ACROSS THE PLAINS INTO THE MISSISSIPPI VALLEY TUESDAY NIGHT. ANOTHER UPPER LEVEL SHORTWAVE ORIGINATING OVER THE CANADIAN ROCKIES FOLLOWS THE MAIN UPPER LONGWAVE AND DIVES SOUTHEAST ACROSS SASKATCHEWAN/MANITOBA INTO THE DAKOTAS AND MINNESOTA ON WEDNESDAY...MERGING WITH THE LONGWAVE TROUGH. THIS WILL BRING COLDER AIR SOUTHWARD INTO THE DAKOTAS TUESDAY NIGHT/WEDNESDAY. PRECIPITATION SHOULD BEGIN ACROSS SOUTHWEST NORTH DAKOTA MONDAY MORNING WITH THE LEADING EDGE OF UPSTREAM UPPER LEVEL ENERGY REACHING THE WESTERN DAKOTAS. MONDAY NIGHT THE AREA OF PRECIPITATION SHOULD SPREAD NORTH AND EAST ACROSS THE STATE AS THE UPPER TROUGH APPROACHES THE WESTERN DAKOTAS...ACCOMPANIED BY STRONG VORT ENERGY IMPULSES AND PLENTY OF MOISTURE ASSOCIATED WITH THE SYSTEM. PRECIPITATION SHOULD BE MAINLY IN THE FORM OF RAIN THROUGH TUESDAY AFTERNOON. AS THE SECOND COLDER SHORTWAVE MOVES SOUTHEAST FROM CANADA TUESDAY NIGHT...THE CHANCES OF RAIN BECOME CHANCES OF LIGHT SNOW FROM NORTHWEST TO SOUTHEAST. SOME AREAS ALONG THE NORTHERN TIER OF COUNTIES MAY SEE SOME LIGHT SNOW ACCUMULATIONS BY WEDNESDAY MORNING. HIGHS WEDNESDAY AND THURSDAY SHOULD BE IN THE 40S ACROSS NORTH DAKOTA WITH LOWS WEDNESDAY NIGHT AND THURSDAY NIGHT IN THE 20S. ANOTHER LONGWAVE TROUGH IS FORECAST TO MOVE INTO THE WEST COAST AND ROCKIES WEDNESDAY...WITH THE MODELS DEVELOPING A CUTOFF LOW OVER THE FAR SOUTHWEST AND ONLY A WEAK UPPER TROUGH MOVING EASTWARD ACROSS THE DAKOTAS FRIDAY. MODEL CONSENSUS KEEPS OUR AREA ON THE DRY SIDE WEDNESDAY NIGHT INTO NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 940 AM CDT SUN OCT 25 2015 FOG AND LOW STRATUS LIFR OVER PARTS OF NORTHERN...KMOT...AND PARTS OF THE JAMES RIVER VALLEY TO CONTINUE UNTIL 16-17Z. OTHERWISE VFR WITH A BRIEF SPRINKLE OF LIGHT RAIN POSSIBLE KBIS- KJMS THROUGH THE DAYLIGHT OF SUNDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JPM SHORT TERM...AC LONG TERM...JV AVIATION...JPM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
639 AM CDT SUN OCT 25 2015 .UPDATE... ISSUED AT 638 AM CDT SUN OCT 25 2015 PATCHY FOG HAD DEVELOPED OVER PORTIONS OF CENTRAL NORTH DAKOTA. THE LATEST ITERATIONS OF THE HRRR WERE CONSISTENT WITH EARLIER RUNS WITH FOG FORMATION MOST LIKELY IN SOUTHERN MANITOBA...SOUTHEASTERN SASKATCHEWAN...INTO NORTH CENTRAL AND PARTS OF EASTERN NORTH DAKOTA. SOME FOG EVIDENT ON SATELLITE PICS IN THOSE AREAS...AS WELL AS SOME OBSERVATION STATIONS. GROUND FOG NOTED HERE IN THE BISMARCK AREA. THUS THINK PREVIOUS FORECAST PACKAGE WITH MENTION OF PATCHY FOG HAS ADDRESSED THIS WELL. OVER SOUTHWESTERN NORTH DAKOTA...LIGHT RADAR RETURNS SUGGEST EITHER SPRINKLES OR PERHAPS JUST VIRGA MOVING EASTWARD IN ASSOCIATION WITH A WEAK UPPER LEVEL IMPULSE MOVING EASTWARD OUT OF EASTERN MONTANA. HAVE KEPT THE MENTION OF MORNING LIGHT RAIN OR LIGHT SNOW. CURRENT FORECAST ON TRACK AND ONLY MINOR ADJUSTMENTS MADE IN HOURLY TEMPERATURES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN OCT 25 2015 FOG IS DEVELOPING IN NORTHERN AREAS AND IS EXPECTED TO LINGER IN THE JAMES RIVER VALLEY THROUGH LATE MORNING...SUPPORTED WELL WITHIN THE CURRENT RAP/HRRR MODEL RUNS. LOW STRATUS DEVELOPMENT IS ALSO POSSIBLE. LIGHT RAIN OVER THE SOUTHEAST WAS CONTINUING TO SLOWLY MOVE EASTWARD OUT OF THE STATE. MEANWHILE...A WEAK SHORT WAVE EMBEDDED WITHIN NORTHWEST FLOW ALOFT IS RESULTING IN LIGHT RAIN IN EASTERN MONTANA. PRECIPITATION IS EXPECTED TO CONTINUE EASTWARD INTO WESTERN NORTH DAKOTA BY 13Z...A WINTRY MIX AND/OR A FEW FLAKES OF SNOW MAY BE POSSIBLE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN OCT 25 2015 THE MAIN FOCUS FOR THE LONG TERM CONTINUES TO BE RAIN/SNOW CHANCES MONDAY THROUGH WEDNESDAY...WITH WIDESPREAD PRECIPITATION EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT. A LONGWAVE TROUGH EXTENDING FROM THE PACIFIC NORTHWEST TO THE 4- CORNERS ON MONDAY MORNING IS PROGGED TO MOVE EAST ACROSS THE ROCKIES MONDAY...DEEPENING AND EMERGING IN THE WESTERN PLAINS MONDAY NIGHT...AND MOVE EASTWARD SLOWLY ACROSS THE PLAINS INTO THE MISSISSIPPI VALLEY TUESDAY NIGHT. ANOTHER UPPER LEVEL SHORTWAVE ORIGINATING OVER THE CANADIAN ROCKIES FOLLOWS THE MAIN UPPER LONGWAVE AND DIVES SOUTHEAST ACROSS SASKATCHEWAN/MANITOBA INTO THE DAKOTAS AND MINNESOTA ON WEDNESDAY...MERGING WITH THE LONGWAVE TROUGH. THIS WILL BRING COLDER AIR SOUTHWARD INTO THE DAKOTAS TUESDAY NIGHT/WEDNESDAY. PRECIPITATION SHOULD BEGIN ACROSS SOUTHWEST NORTH DAKOTA MONDAY MORNING WITH THE LEADING EDGE OF UPSTREAM UPPER LEVEL ENERGY REACHING THE WESTERN DAKOTAS. MONDAY NIGHT THE AREA OF PRECIPITATION SHOULD SPREAD NORTH AND EAST ACROSS THE STATE AS THE UPPER TROUGH APPROACHES THE WESTERN DAKOTAS...ACCOMPANIED BY STRONG VORT ENERGY IMPULSES AND PLENTY OF MOISTURE ASSOCIATED WITH THE SYSTEM. PRECIPITATION SHOULD BE MAINLY IN THE FORM OF RAIN THROUGH TUESDAY AFTERNOON. AS THE SECOND COLDER SHORTWAVE MOVES SOUTHEAST FROM CANADA TUESDAY NIGHT...THE CHANCES OF RAIN BECOME CHANCES OF LIGHT SNOW FROM NORTHWEST TO SOUTHEAST. SOME AREAS ALONG THE NORTHERN TIER OF COUNTIES MAY SEE SOME LIGHT SNOW ACCUMULATIONS BY WEDNESDAY MORNING. HIGHS WEDNESDAY AND THURSDAY SHOULD BE IN THE 40S ACROSS NORTH DAKOTA WITH LOWS WEDNESDAY NIGHT AND THURSDAY NIGHT IN THE 20S. ANOTHER LONGWAVE TROUGH IS FORECAST TO MOVE INTO THE WEST COAST AND ROCKIES WEDNESDAY...WITH THE MODELS DEVELOPING A CUTOFF LOW OVER THE FAR SOUTHWEST AND ONLY A WEAK UPPER TROUGH MOVING EASTWARD ACROSS THE DAKOTAS FRIDAY. MODEL CONSENSUS KEEPS OUR AREA ON THE DRY SIDE WEDNESDAY NIGHT INTO NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 638 AM CDT SUN OCT 25 2015 FOG AND LOW STRATUS DEVELOPMENT OVER CENTRAL AND EASTERN AREAS IS EXPECTED TO LINGER THROUGH MID MORNING...WITH IFR CONDITIONS POSSIBLE AT KBIS/KJMS AND HIGHER CONFIDENCE OF LIFR/VLIFR CONDITIONS AT KMOT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...AC LONG TERM...JV AVIATION...AC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
133 AM CDT SUN OCT 25 2015 .UPDATE... ISSUED AT 133 AM CDT SUN OCT 25 2015 ADJUSTMENTS TO POPS WERE MADE AS RAIN CONTINUES TO SLOWLY PUSH EAST. CLOUDS WERE ALSO INCREASED TO REFLECT THE LATEST SATELLITE DATA. EARLY MORNING CONDITIONS ARE FAVORABLE FOR THE DEVELOPMENT OF FOG AND LOW STRATUS...SUPPORTED WELL WITHIN THE CURRENT RAP/HRRR MODELS. UPDATE ISSUED AT 954 PM CDT SAT OCT 24 2015 SHOWERS CONTINUE TO PUSH OFF TO THE SOUTHEAST...NOW OVER FAR SOUTH CENTRAL ND INTO THE SOUTHERN JAMES RIVER VALLEY...AND SHOULD EXIT OFF TO OUR SOUTH AND EAST BY 04-05Z. LATEST FEW HRRR RUNS STILL INDICATE THE POTENTIAL FOR PATCHY FOG AND LOW STRATUS DEVELOPMENT OVERNIGHT AND INTO SUNDAY MORNING...BEGINNING EAST AND EXPANDING WESTWARD WITH AN EASTERLY UPSLOPE WIND COMPONENT. UPDATE ISSUED AT 720 PM CDT SAT OCT 24 2015 EMBEDDED MID LEVEL S/WV TROUGH AND ASSOCIATED SUBTLE SFC LOW PRESSURE CONTINUE TO PUSH SOUTHEAST ACROSS NORTH DAKOTA. SCATTERED SHOWERS NOW OVER THE EASTERN ONE HALF OF THE STATE...FROM THE SOUTH CENTRAL AND FAR NORTH CENTRAL...INTO THE EASTERN THIRD OF THE STATE. A FEW EMBEDDED THUNDERSTORMS IN THE SHOWERS...INCLUDING A SQUALL REPORTED AT THE GRAND FORKS AIRPORT WHICH GENERATED A 35KT WIND GUST. STILL SOME LIGHTNING ACTIVITY OVER MY NORTH CENTRAL...SO HAVE OPTED TO KEEP A SLIGHT CHANCE FOR THUNDER THROUGH 02Z. CLEARING SKIES WEST WILL TREND INTO CENTRAL NORTH DAKOTA OVER THE NEXT FEW HOURS. MODELS HAVE BACKED OFF ON THE ONSET OF PRECIPITATION OVER WESTERN NORTH DAKOTA SUNDAY MORNING...NOW NOT EXPECTED UNTIL MID TO LATE MORNING. THUS THE POTENTIAL FOR A MIX OF RAIN/SNOW IS ZERO SO WILL JUST GO WITH RAIN MID MORNING SUNDAY - MID AFTERNOON SUNDAY WEST CENTRAL. UPDATE ISSUED AT 539 PM CDT SAT OCT 24 2015 A FEW LIGHTNING STRIKES NOW TO THE WEST-NORTHWEST OF BISMARCK...ALONG WITH MORE SHOWING UP NORTH OF MY NORTHEAST. WILL THROW A SLIGHT CHANCE FOR THUNDER INTO THE LATE AFTERNOON/EARLY EVENING FORECAST. UPDATE ISSUED AT 528 PM CDT SAT OCT 24 2015 SHOWERS A TAD MORE ROBUST AND FARTHER SOUTH SO WILL SEND A QUICK UPDATE TO ACCOMMODATE. ISOLATED MODERATE SHOWERS OVER OLIVER COUNTY PUSHING EAST-SOUTHEAST. HAD A FEW LIGHTNING STRIKES WITH BAND OF SHOWERS NORTH OF BOTTINEAU/ROLETTE COUNTY A FEW RADAR SCANS AGO. OPTED NOT TO PUT IN THUNDER FOR NOW AND WILL MONITOR. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 215 PM CDT SAT OCT 24 2015 CURRENT SURFACE ANALYSIS PLACES TROUGH OVER THE GREAT LAKES REGION WITH BROAD RIDGING OVER THE WESTERN CONUS. UPPER LEVEL ANALYSIS PLACES TROUGH OVER THE MIDWEST WITH RIDGE OVER THE FAR WESTERN CONUS. SLIGHTLY CYCLONIC NORTHWESTERLY FLOW REMAINS OVER OUR AREA AS A WEAK SHORT WAVE SLIDES THROUGH...PRODUCING SOME VERY LIGHT RAIN SHOWERS OVER NORTHERN PORTIONS OF THE AREA. FOR THE REMAINDER OF THIS AFTERNOON INTO TONIGHT...A FEW LIGHT RAIN SHOWERS WILL CONTINUE INTO TONIGHT OVER CENTRAL PORTIONS OF THE STATE SLIDING EAST AS THE AFOREMENTIONED WAVE WORKS THROUGH THE AREA. OTHERWISE...THE ONLY OTHER CONCERN IS THE POTENTIAL FOR FOG DEVELOPMENT. FORECAST SOUNDINGS SUGGEST THE POSSIBILITY FOR THIS FROM NORTH-CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY. ON SUNDAY...SOME FOG MAY LINGER OVER AFOREMENTIONED AREAS INTO THE MORNING HOURS. OTHERWISE...THE NEXT IN A ROUND OF WEAK SHORT WAVES WILL THROUGH NORTHWESTERLY FLOW. THIS MAY BRING SOME LIGHT RAIN TO WESTERN AND CENTRAL AREAS...THOUGH CHANCES REMAIN LOW WITH THE MAIN CHANGE BEING INCREASING CLOUD COVER. WITH THE COOL MORNING TEMPERATURES...A FEW FLAKES OF SNOW WILL NOT BE OUT OF THE QUESTION OVER PORTIONS OF THE WEST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 215 PM CDT SAT OCT 24 2015 THE MAIN FOCUS FOR THE LONG TERM CONTINUES TO BE RAIN/SNOW CHANCES MONDAY AFTERNOON THROUGH WEDNESDAY. PRECIPITATION SHOULD BEGIN ACROSS SOUTHWEST NORTH DAKOTA MONDAY AFTERNOON AS WEAK LEAD WAVE ENTERS EASTERN MONTANA. MORE WIDESPREAD PRECIPITATION IS EXPECTED TUESDAY AS A VERY HIGH AMPLITUDE TROUGH DIGS INTO THE NORTHERN PLAINS. THE 12 UTC SUITE OF MODELS CONTINUE TO SHOW A LONGWAVE TROUGH SWINGING THROUGH THE NORTHERN PLAINS TUESDAY AND WEDNESDAY. THE GFS/ECMWF/CANADIAN APPEAR TO BE IN FAIRLY GOOD AGREEMENT WITH THE PROGRESSION OF THIS SYSTEM. THE TROUGH IS FORECAST TO DEEPEN AND TIGHTEN UP JUST EAST OF NORTH DAKOTA. THE LATEST RUNS ARE A LITTLE MORE PROGRESSIVE WITH THE DEVELOPMENT OF THIS TROUGH. THIS WILL LIKELY KEEP PRECIPITATION AMOUNTS MINIMAL. A MIX OF RAIN AND SNOW IS POSSIBLE DURING THE OVERNIGHT HOURS WHEN DYNAMIC AND DIURNAL COOLING WILL LIKELY COINCIDE...HOWEVER...LITTLE TO NO ACCUMULATION IS EXPECTED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 133 AM CDT SUN OCT 25 2015 FOG AND LOW STRATUS DEVELOPMENT IS POSSIBLE OVER CENTRAL AND EASTERN NORTH DAKOTA...SUPPORTED WELL WITHIN THE CURRENT RAP/HRRR MODELS. POSSIBLE IFR CONDITIONS AT KBIS WITH HIGHER CONFIDENCE OF LIFR/VLIFR CONDITIONS AT KMOT AND KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AC SHORT TERM...JJS LONG TERM...AJ AVIATION...AC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
741 PM EDT MON OCT 26 2015 .SYNOPSIS... UPPER LEVEL SYSTEM WITH REMNANTS OF PATRICIA BRINGS RAIN LATE TONIGHT AND TUESDAY INTO WEDNESDAY. COLD FRONT CROSSES LATE WEDNESDAY. HIGH PRESSURE CROSSES FRIDAY THROUGH SATURDAY. && .NEAR TERM /THROUGH TUESDAY/... 730 PM UPDATE. NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION... NO REAL SIGNIFICANT CHANGES NEEDED TO PREVIOUS FORECAST. TWEAKED POPS SOME TODAY TO REFLECT CURRENT TRENDS USING HRRR AND WRFARW. FOR TONIGHT INTO TUESDAY TRIED TO ENHANCE THE DOWNSLOPE PRECIP SHADOW SOME IN THE I79 CORRIDOR...GOING WITH POP/QPF MINIMUM THERE. ON THE OTHER HAND...INCREASED POPS ACROSS THE EASTERN SLOPES AND FAR WESTERN CWA TO AT OR NEAR 100 PERCENT BY TOMORROW AFTERNOON AS A DEFORMATION BAND SLIDES NORTH ACROSS THE CWA. THIS IS ASSOCIATED WITH THE SURFACE LOW CURRENTLY COMING ASHORE FROM THE GULF OF MEXICO. THIS LOW WILL GRADUALLY DRIFT NORTHWARD UP THE MISSISSIPPI RIVER VALLEY THROUGH THE PERIOD AS IT STARTS TO FEEL THE INFLUENCE OF A STRONG UPPER LEVEL LOW ENTERING CENTRAL CANADA. WINDS WILL PICK UP TOMORROW AS 850MB FLOW INCREASES OUT OF THE E/SE TUESDAY. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... STOUT BAROCLINIC LEAF READILY EVIDENT ON STLT TODAY OVER SE 1/4 OF THE CONUS. ASSOCIATED WITH UPPER LEVEL LOW OVER THE LOWER MISSISSIPPI VALLEY...THE CONFLUENCE ZONE WHERE THE NRN AND SRN STREAM JETS MEET OVER THE MID ATLANTIC REGION SERVED TO ENHANCE THE EFFECT. THE UPPER LEVEL LOW OPENS UP AS IT LIFTS NEWD TONIGHT...AND BECOMES A RATHER FLAT WAVE BY THE TIME IT CROSSES THE CWA TUE NT...IN SW UPPER LEVEL FLOW AHEAD OF A LARGER UPPER LEVEL TROUGH FAST APPROACHING FROM THE W EVEN AS IT FORMS OUT OF SEVERAL SMALLER S/W TROUGHS. THE ORIGINAL SFC FEATURE BECOMES WASHED OUT BY THE TIME IT REACHES THE CWA TUE NT...BUT A TIGHT W TO E LOW LEVEL GRADIENT SPELLS A CLASSIC RAIN SHADOW EFFECT ON STRONG SE FLOW. WITH THIS...AND MOST OF THE FORCING OUTSIDE UPSLOPE GENERATED IN THE UPPER LEVELS...RAINFALL TUE NT INTO WED SHOULD BE MANAGEABLE...A SLOW SOAKER WITH UP TO A HALF AN INCH OVER SIX HOUR PERIOD IN THE ERN UPSLOPE AREA OF WV...AND SLIGHTLY LESS OVER THE WRN FRINGES...AND LESS THAN A QUARTER INCH OVER SIX HOURS IN THE SHADOW AREA IN BETWEEN. MOMENTUM TRANSFER ALGORITHMS DO NOT MIX MUCH OF THE 70KTS SHOWN AT H85 OFF THE NAM12 TO THE SFC. THE STRONG INVERSION CREATED BY COOL ATLANTIC AIR FLOWING IN ON THE BACK SIDE OF A STRONG SFC HIGH SLIDING OFF THE NEW ENGLAND COAST...BENEATH WARMER AIR FLOWING IN ON SW MID LEVEL FLOW...WILL KEEP STRONG WIND GUSTS LIMITED TO THE VERY HIGHEST RIDGES. A NRN STREAM UPPER LEVEL LOW THEN DIGS INTO THE UPPER TROUGH...AS THE FINAL PIECE OF THE PUZZLE THAT ESTABLISHES A L/W TROUGH OVER THE ERN CONUS COME THU. A SFC LOW DEEPENS RAPIDLY WED IN RESPONSE TO THE DIGGING UPPER LEVEL LOW...AND PULLS QUICKLY NEWD...REACHING JAMES BAY IN CENTRAL CANADA BY THU MORNING. THIS PULLS A STRONG SFC COLD FRONT THROUGH THE AREA LATE WED INTO WED NT...FOLLOWED BY STRONG COLD ADVECTION INTO THU. THIS RESULTS IN GOOD MIXING THROUGH WED NT AND THU...ONCE THE LOW LEVEL INVERSION IS TAKEN OUT ON WED. THIS ALSO DRIES OUT THE WEATHER...AND STRONGER WIND GUSTS ARE REALIZED ON THU. THU EVENING FINDS THE L/W ALREADY LIFTING OUT THROUGH THE NERN STATES. TEMPERATURES TAKE A NON DIURNAL ROLLER COASTER RIDE...STEADY OR SLOWLY RISING ON TUE NT...AND THEN NEARLY STEADY IN THE COLD ADVECTION DURING THE DAY ON THU AS H85 TEMPERATURES DROP ABOUT 5C. USED MOSTLY TO NAM BASED GUIDANCE. HIGHS ARE NEAR THE LOW END OF THE GUIDANCE ENVELOP ON WED AND THE HIGH END ON THU WITH BETTER MIXING AND INCREASING SUNSHINE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE UPPER TROF LIFTS AS QUICKLY AS IT ARRIVED THURSDAY NIGHT...TO BE REPLACED BY BUILDING HEIGHTS. THIS IS ALL IN RESPONSE TO A BUILDING RIDGE OVER THE W ATLANTIC. WHILE THIS WILL ENSURE DRY WX THRU SATURDAY...THE END OF THE WEEKEND AND EARLY NEXT WEEK LOOKS UNSETTLED. THE CULPRIT BEING AN UPPER LOW EJECTING OUT OF THE SW CONUS AND INTERACTING WITH THE N STREAM. GLOBAL MODEL SOLUTIONS VARY WITH AXIS OF THE UPPER RIDGE WHICH WILL BE CRUCIAL IN DETERMINING JUST HOW WET WET GET. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... 00Z TUESDAY THRU 00Z WEDNESDAY... FOG NOT AS DENSE OR WIDESPREAD IN THE NORTHERN MOUNTAIN VALLEYS LATER TONIGHT...AS CLOUDS AND EASTERLY BREEZE INCREASE LATE. WILL LOWER KEKN TO MVFR VSBY 09Z TO 12Z...IMPROVING THEREAFTER. RAIN SHIELD...WELL AHEAD OF A LOW PRESSURE SYSTEM CENTERED NEAR THE CENTRAL GULF COAST...WILL LIFT SLOWLY NORTHWARD TO ENCOMPASS MOST OF THE AREA BY LATER TUESDAY AFTERNOON. RAIN WILL OVERSPREAD THE AREA SOUTH OF THE I64 CORRIDOR BY 12Z TUESDAY...AND THE REMAINDER OF THE AREA BY 22Z TUESDAY. HOWEVER...WHILE CLOUDS WILL LOWER AND THICKEN FROM SOUTH TO NORTH THIS PERIOD...WE EXPECT GENERAL VFR CONDITIONS TO HOLD WEST OF THE MOUNTAINS EVEN IN THE RAIN SHIELD TIL 18Z TUESDAY...DUE TO INCREASING SOUTHEAST LOW LEVEL FLOW LATER TONIGHT AND TUESDAY. HOWEVER...OVER EAST FACING SLOPES OF THE MOUNTAINS...EXPECT MVFR TO MOVE IN BY 12Z TUESDAY INCLUDING KBKW. AFTER 18Z...CONDITIONS GENERALLY LOWERING TO MVFR FROM SOUTH TO NORTH IN THE WIDESPREAD SHOWERS BY 00Z...POSSIBLY IFR OVER THE EAST FACING SLOPES OF THE SOUTHERN MOUNTAINS INCLUDING KBKW. LOOK FOR INCREASING EAST TO SOUTHEAST WINDS TUESDAY AFTERNOON...ESPECIALLY ON MOUNTAIN RIDGETOPS WHERE GUSTS MAY BE 20 KTS OR MORE. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: FOG MAY NOT FORM AT EKN. TIMING OF SHOWERS MAY BE SLOWER THAN FORECAST. 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 21 22 23 00 01 02 03 04 05 06 07 08 EDT 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 00Z WEDNESDAY... INCREASING SOUTHEAST WIND TUESDAY NIGHT INTO WEDNESDAY WILL LIKELY LEAD TO IFR CIGS ALONG THE EASTERN SLOPES. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ/30 NEAR TERM...JMV/MZ SHORT TERM...TRM LONG TERM...30 AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
204 AM EDT SUN OCT 25 2015 .SYNOPSIS... COLD FRONT MOVES THROUGH OVERNIGHT. STRONGER LOW PRESSURE AND COLD FRONT MID WEEK. HIGH PRESSURE BY NEXT WEEKEND. && .NEAR TERM /THROUGH TODAY/... 800 PM UPDATE... COLD FRONT AS OF 00Z ENTERING NW OH...MARKED BY A VERY THIN BAND OF MODERATE SHRA. AHEAD OF THE FRONT MOSTLY LIGHT SHRA CONCENTRATED W OF THE OH RIVER. TIMING OF FRONT TWEAKED TO LATEST HRRR RUNS. HAVING IT THRU SE OH BY 06Z...E OF CKB/CRW BY 08Z...AND EXITING THE S ZONES TOWARD DAYBREAK. THINKING POST FRONTAL STRATUS WILL LINGER AT LEAST INTO THRU THE MORNING HOURS AND QUITE POSSIBLY INTO THE AFTERNOON. IN FACT SW VA AND SE WV MAY HOLD ON TO STRATUS UNTIL DUSK. THIS IS THE RESULT OF A SUBSIDENCE INVERSION BUILDING OVER TOP LINGERING LOW LEVEL MOISTURE. PREVIOUS DISCUSSION BELOW... MODELS SHOWING A GOOD BAND OF LIFT ALONG AND IN ADVANCE OF THE COLD FRONT THAT MOVES THROUGH OVERNIGHT...SO WILL INCREASE POPS A BIT MORE. WILL ALSO MAKE A FEW TIMING TWEAKS. A GOOD DRY AIR PUSH BEHIND THE FRONT SHOULD END PRECIPITATION CHANCES FAIRLY QUICKLY...SO WILL TIGHTEN UP THE GRADIENT THERE AS WELL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... MODELS INDICATE HIGH PRESSURE WILL MOVE QUICKLY ACROSS THE NORTHERN PART OF OUR FORECAST AREA SUNDAY NIGHT...ALLOWING SOUTHEAST LOW- LEVEL WINDS TO RETURN TO THE FORECAST AREA. AN AREA OF LOW PRESSURE ALONG THE LA COAST AT THE BEGINNING OF THE PERIOD WILL NORTH INTO THE LOWER OHIO VALLEY. COMBINATION OF LOW- LEVEL MOISTURE...FROM THE GULF AND THE REMNANTS OF PATRICIA...WILL RESULT IN ABUNDANT LOW LEVEL MOISTURE FLOWING INTO THE FORECAST AREA. WHILE THERE ARE SOME DISCREPANCIES IN THE ONSET OF PRECIPITATION... SMALL CHANCES OF PRECIPITATION SHOULD CONTINUE ACROSS OUR FAR SOUTH SUNDAY NIGHT INTO MONDAY AS THE HIGH PUSHES EAST. THE PRECIPITATION CHANCES SHOULD THEN INCREASE AND SPREAD NORTH ACROSS THE REMAINDER OF THE AREA MONDAY NIGHT AND TUESDAY. LATEST GUIDANCE AND NBM DATA WERE RELATIVELY CLOSE TO PREVIOUS FORECAST NUMBERS THROUGH THE PERIOD...SO ONLY MINOR TWEAKS WERE MADE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS ARE TRENDING FASTER WITH THE STRONG UPPER TROUGH AND COLD FRONT COMING ACROSS MID WEEK. THEY ARE ALSO INGESTING THE REMAINS OF THE TROPICAL SYSTEM FROM THE WESTERN GULF OF MEXICO FASTER. THIS RESULTS IN THE WIDESPREAD SHIELD OF RAIN SHOWERS AHEAD OF THE OVERALL SYSTEM ALREADY INTO MUCH OF THE AREA BY TUESDAY EVENING. THE RAIN SHOWERS WILL CONTINUE THROUGH MUCH OF WEDNESDAY BEFORE THE COLD FRONT MOVES THROUGH. THE COLD FRONT WILL BE THROUGH THE WESTERN HALF OF THE AREA BY WEDNESDAY EVENING...THEN EXITING THE MOUNTAINS BEFORE MIDNIGHT WEDNESDAY NIGHT. THE UPPER TROUGH TAKING ON A NEGATIVE TILT THANKS TO THE ABSORPTION OF THE TROPICAL SYSTEM...AND A STRONG SOUTHEAST FLOW CREATING A RELATIVE SHADOW ZONE WEST OF THE MOUNTAINS...LEADS TO THE HEAVIER QPF LIFTING TO THE WEST OF OUR AREA. THE RESULT WILL BE WHILE HAVING CAT POPS AND WIDESPREAD SHOWERS TUESDAY NIGHT AND WEDNESDAY...THE QPF WILL DIMINISHED SOMEWHAT BY THESE FACTORS. THUS...WITH THIS AND THE DRY GROUND...NO WATER PROBLEMS ARE EXPECTED. IN ADDITION...INSTABILITY IS WEAK...SO THUNDER IS LEFT OUT OF THE FORECAST. BEHIND THE FRONT FOR WEDNESDAY NIGHT AND THURSDAY...A WESTERLY FLOW REGIME WITH WEAK COLD ADVECTION WILL LEAD TO LESS THAN EXPECTED POST FRONTAL SHOWERS. WE DO HAVE SOME LOW POP POST FRONTAL SHOWERS...MAINLY NORTHERN MOUNTAINS...BUT THESE MAY BE TOO GENEROUS. IN ANY EVENT...IS SHOWERS DO LINGER INTO THURSDAY NIGHT...THERE MAY BE SOME FLAKES IN THE HIGHER ELEVATIONS OF THE NORTHERN MOUNTAINS...BUT ANY ACCUMULATIONS WILL BE MINIMAL. HIGH PRESSURE WITH DRY WEATHER AND NEAR NORMAL TEMPERATURES CAN BE EXPECTED FOR FRIDAY AND SATURDAY. TEMPS WILL GO FROM ABOVE NORMAL AHEAD OF THE FRONT TO NEAR NORMAL BEHIND THE FRONT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... COLD FRONT CROSSES THE AREA. MOST AREAS GENERALLY VFR...EXCEPT IN FRONTAL SHOWERS WHERE MVFR IS MORE PREVALENT. INCLUDED A FEW ISOLATED IFR CONDITIONS AS FRONT PASSES. BELIEVE MVFR AND VFR MIX WILL FOLLOW FRONT BEFORE DOMINANT VFR TAKES HOLD THIS AFTERNOON. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: TIMING OF RESTRICTIONS WITH SHOWERS AND LOWER CLOUDS ALONG FRONT COULD VARY. TIMING OF ERADICATION OF MVFR STRATUS SUNDAY WILL VARY. 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 SUN 10/25/15 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H M L M M H M M M M M M HTS CONSISTENCY M M M H H H H H M M H H BKW CONSISTENCY H M H M L L L L L L L M EKN CONSISTENCY H H M M M M M M M L L L PKB CONSISTENCY M M H M H H M M M M M H CKB CONSISTENCY M M L M M H M M M M M M AFTER 06Z MONDAY... INCREASING SOUTHEAST WIND TUESDAY NIGHT INTO WEDNESDAY COULD FORM IFR CEILINGS ON THE EASTERN SLOPES. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JSH/RPY/JMV NEAR TERM...RPY/30 SHORT TERM...JSH LONG TERM...JMV AVIATION...JW
AREA FORECAST DISCUSSION
NWS PORTLAND OR
905 AM PDT SUN OCT 25 2015 .SYNOPSIS...A LOW PRES SYSTEM OFF THE OREGON COAST WILL SPREAD RAIN ACROSS THE REGION TODAY. A SECONDARY UPPER LEVEL TROUGH WILL MAINTAIN SHOWERS TONIGHT THROUGH MONDAY. HIGH PRESSURE AND EAST WINDS WILL RETURN TUESDAY FOR DRY WEATHER. ANOTHER...SIMILAR LOW PRESSURE SYSTEM WILL BRING MORE RAIN WEDNESDAY AND THURSDAY. && .SHORT TERM...SATELLITE IMAGERY SHOWED AN UPPER LEVEL TROUGH OFF THE OREGON COAST SUN MORNING...TAKING ON A NEGATIVE TILT. A SURFACE FRONT WAS APPROACHING THE CENTRAL AND S OREGON COAST...PUSHING E OVER SW OREGON...WHILE MAKING SLOWER PROGRESS NE OVER NW OREGON. A BAND OF RAIN PRECEDED THE FRONT...DRIVEN BY MOIST ISENTROPIC LIFT IN MID LEVELS AROUND 300K ISENTROPE. OFFSHORE FLOW AHEAD OF THE FRONT THIS MORNING WILL SWITCH TO ONSHORE FLOW BEHIND THE FRONT AS IT MOVES INLAND TODAY...EARLIEST IN THE S PART OF THE FORECAST...LATER IN THE DAY IN THE N. MODELS CONTINUED TO SHOW A SWITCH TO A SHOWERY PATTERN BEHIND THE FRONT AS LOW LEVEL MOISTEN AND DESTABILIZE. LAYER OF INSTABILITY EXPECTED TO BE 10K TO 15K FT DEEP...DEEPEST IN THE N. REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL SHORT WAVE TROUGH OFF OF THE B.C. COAST. THIS SECONDARY TROUGH WILL MOVE SOUTH TODAY AND CONTINUE SHOWERS OVER SW WASHINGTON AND EXTREME NW OREGON TONIGHT INTO MONDAY. ONSHORE WINDS WILL RETURN TONIGHT AS THIS TROUGH NEARS AND SNOW LEVELS WILL LOWER TO AROUND 7000 FEET MONDAY MORNING...SUCH THAT MOUNT HOOD... ADAMS...AND SAINT HELENS MAY SEE A COUPLE OF INCHES OF FRESH SNOW NEAR THEIR PEAKS. SHOWERS WILL END MONDAY EVENING AS AN UPPER LEVEL RIDGE MOVES OVER THE PACIFIC NW. OFFSHORE WINDS WILL RETURN TUESDAY WITH HIGH PRESSURE MOVING INLAND AND ANOTHER LOW DEVELOPING OFFSHORE. THIS WILL RESULT IN DRY WEATHER TUESDAY WITH SLIGHTLY WARMER TEMPERATURES. TJ .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...PREVIOUS DISCUSSION)...TUESDAY NIGHT THROUGH SATURDAY...NEXT LOW PRESSURE SYSTEM APPROACHES MIDWEEK...WITH ACTIVE WEATHER PATTERN CONTINUING THROUGH LATE NEXT WEEK. RAIN MOVES BACK IN WEDNESDAY THROUGH THURSDAY WITH THIS SYSTEM. RIGHT NOW MODELS SHOW SHORTWAVE RIDGING BUILDING IN ON FRIDAY...WHICH SHOULD KEEP MOST OF OUR AREA DRY UNTIL THE NEXT LOW PRESSURE SYSTEM BRINGS MORE RAIN NEXT WEEKEND. -MCCOY && .AVIATION...SURFACE LOW ABOUT 150 TO 200 NM WEST OF KONP AT 15Z WILL CONTINUE TO DRIFT NE TODAY. OFFSHORE FLOW HAS STRENGTHENED... W ITH THE KTTD-KDLS GRADIENT AT -7.7 MB AS OF 15Z. WIND GUSTS UP TO 60 KT IN WIND-FAVORED AREAS OF THE WEST COLUMBIA GORGE. GRADIENT SHOULD START TO WEAKEN LATE THIS AFTERNOON. THERE IS THE POTENTIAL FOR LLWS NEAR THE WEST COLUMBIA GORGE THROUGH THIS AFTERNOON. GENERALLY VFR INLAND THROUGH THE MORNING THEN EXPECT AREAS OF MVFR...ESPECIALLY AWAY FROM THE COLUMBIA GORGE WHERE THE OFFSHORE FLOW WILL RESULT IN HIGHER CIGS. COASTAL AREAS TO SEE INCREASING MVFR THIS MORNING AS THE FRONT MOVES ASHORE. THERE IS THE POSSIBILITY OF IFR ALONG THE CENTRAL OREGON COAST. THE FRONT SHOULD CLEAR THE REGION BY LATE AFTERNOON...WITH RAIN TAPERING TO SHOWERS AND CONDITIONS GENERALLY IMPROVING TO VFR. HOWEVER MVFR CONDITIONS SHOULD RETURN TO THE COAST THIS EVENING. KPDX AND APPROACHES...VFR THROUGH ABOUT 19Z...THEN A MIX OF MVFR AND LOW-END VFR DURING THE AFTERNOON. PREDOMINANT VFR RETURNS AFTER 00Z. E WIND 20-30 KT THROUGH THE AFTERNOON. STRONGEST WIND OVER THE W END OF THE COLUMBIA GORGE WHERE GUSTS TO 45 KT ARE LIKELY. MAY BE AREAS OF LLWS WITH S WIND ABOVE 2K FEET. WIND WILL SWITCH TO SW LATE THIS AFTERNOON OR EARLY EVENING. WEISHAAR && .MARINE...SURFACE ANALYSIS HAS 998 MB LOW CENTER NEAR 45N 128W AT 7 AM. THE LOW IS FORECAST TO TRACK NE AND WEAKEN TODAY AS IT MOVES TOWARD THE CENTRAL WASHINGTON COAST. WILL MAINTAIN GALE WARNINGS FOR THE SRN WATERS...BUT BASED MORE ON GUSTS THAN SUSTAINED SPEEDS. BUOY 46015...NEAR PORT ORFORD...HAS HAD GUSTS 40-45 KT SINCE 12Z. COULD BE A FEW GUSTS TO 40 KT IN THE SRN OUTER WATERS. BEST POTENTIAL FOR ANY LOW-LEVEL JET DEVELOPMENT WOULD BE OVER THE SRN INNER WATERS THIS AFTERNOON. OFFSHORE COMPONENT CONTINUES OVER THE NRN WATERS THROUGH MUCH OF THE DAY. STILL SOME QUESTION AS TO WHERE THE LOW MAKES LANDFALL. LATEST NAM AND 13Z RUC SHOW THE LOW NEAR THE MOUTH OF THE COLUMBIA RIVER AT 00Z MON. GFS AND ECMWF ARE A LITTLE MORE NORTH. THERE IS THE POSSIBILITY OF GALE FORCE GUSTS OVER THE OREGON NRN WATERS THIS AFTERNOON AND EARLY EVENING...WITH THE 12Z GFS INDICATING 30 KT BOUNDARY LAYER WIND SPEEDS LATE THIS AFTERNOON. WIND SPEEDS DIMINISH THIS EVENING AND TONIGHT AS THE PRESSURE GRADIENT EASES. AFTER A LULL MON AFTERNOON THROUGH TUE NIGHT...ANOTHER SPLITTING SYSTEM IS FORECAST TO IMPACT THE WATERS WED. SHOULD SEE SMALL CRAFT ADVISORY SPEEDS WITH THIS SYSTEM AS WELL. INCREASING W-SW SWELL ASSOCIATED WITH THE WINDS FROM THIS SYSTEM TO MOVE INTO THE WATERS TODAY. SEAS WILL LIKELY REACH 12-15 FT BY THIS AFTERNOON...GRADUALLY SUBSIDING SUNDAY NIGHT AND MONDAY AS THE LOW CONTINUES TO FILL AND MOVE ONSHORE. SEAS SHOULD DROP BELOW 10 FT LATER MON AND TUE...BUT THE NEXT SYSTEM TUE NIGHT/WED SHOULD BRING ANOTHER ROUND OF SEAS IN THE 12-15 FT RANGE. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT MONDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 AM PDT MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM. GALE WARNING UNTIL 11 AM PDT THIS MORNING FOR WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM. GALE WARNING UNTIL 2 PM PDT THIS AFTERNOON FOR COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 5 AM PDT MONDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
933 PM PDT SAT OCT 24 2015 .SYNOPSIS...A LOW PRES SYSTEM OFF THE OREGON COAST WILL SLOWLY WEAKEN AND MOVE E TONIGHT AND SUN...BRINGING RAIN TO MOST OF THE REGION. A SECONDARY UPPER LEVEL TROUGH OF LOW PRES WILL FOLLOW SUN NIGHT KEEPING A THREAT FOR SHOWERS GOING THROUGH MON. HIGH PRESSURE MON NIGHT AND TUE SHOULD WILL RESULT IN DRIER WEATHER...BEFORE THE NEXT LOW PRESSURE SYSTEM BRINGS ANOTHER CHANCE FOR RAIN ON WEDNESDAY. && .UPDATE...RAIN ASSOCIATED WITH A WEAK COLD FRONT IS BEGINNING TO MOVE ONSHORE THIS EVENING AND WILL SPREAD ACROSS THE AREA DURING THE OVERNIGHT HOURS...ALTHOUGH ACCUMULATIONS SHOULD BE RELATIVELY LIGHT TONIGHT. HIGH RESOLUTION MODELS SHOW MORE SIGNIFICANT RAINFALL MOVING INTO THE AREA SUNDAY MORNING AS THE LOW AND UPPER LEVEL TROUGH CURRENTLY OFFSHORE MOVE CLOSER. RAIN SHOULD PROVIDE A GOOD SOAKING BUT NOTHING MORE. UPDATED FORECAST A BIT EARLIER THIS EVEN TO MOVE POPS UP IN TIME WEST OF THE VALLEY BASED ON LATEST RADAR TRENDS. DOES NOT LOOK LIKE ANY ADDITIONAL UPDATES WILL BE NEEDED THIS EVENING. BOWEN .SHORT TERM (PREVIOUS DISCUSSION)...SATELLITE PICS EARLY SAT AFTERNOON SHOWED A LOW ABOUT 250 NM OFF THE S OREGON COAST...WITH AN ACTIVE BAND OF SHOWERS NEAR 127W ASSOCIATED WITH AN OCCLUDED FRONT AHEAD OF THE LOW. MODELS BRING THIS FEATURE TO THE COAST THIS EVENING...WHILE SLOWLY WEAKENING THE OVERALL SYSTEM AS UPPER LEVEL DYNAMICS STRETCH OUT. WILL SEE CHANCES FOR PRECIPITATION INCREASE ON THE COAST THIS EVENING...WITH A CHANCE FOR SOME RAIN SPREADING INLAND LATER IN THE NIGHT. THE BETTER THREAT FOR MORE WIDESPREAD PRECIPITATION WILL SPREAD IN EARLY SUN AS THE MAIN UPPER TROUGH PUSHES INLAND AND A WRAP AROUND OCCLUSION MOVES INLAND. AN AREA OF MID AND UPPER LEVEL MOISTURE AND MODEST ISENTROPIC LIFT BEST SEEN NEAR THE 300K ISENTROPE WILL PRECEDE THE FRONT SPREADING CHANCES FOR RAIN INLAND DURING THE MORNING. LOW TO MID LEVEL MOISTURE WILL FOLLOW THE FRONT WITH MODEL SOUNDINGS INDICATING AN UNSTABLE LAYER BELOW 10K FT THAT SHOULD BE CONDUCIVE TO POST FRONTAL SHOWERS SUN AFTERNOON. WITH PLENTY OF CLOUDS AND PRECIPITATION AROUND SUN AS THE UPPER TROUGH MOVES IN EXPECT TO SEE HIGH TEMPS DIP TO A LITTLE BELOW NORMAL. MODELS ALL INDICATE THE SURFACE LOW WEAKENING AS IT APPROACHES THE COAST SUN...EVENTUALLY TRACKING NE TOWARDS THE OLYMPIC PENINSULA SUN EVENING. GRADIENTS LOOK CONSIDERABLY WEAKER AS THE SYSTEM MAKE LANDFALL SO HIGH WINDS ARE UNLIKELY...BUT ENOUGH GRADIENT EXISTS FOR SOME GUSTY WINDS ON THE COAST SUN AFTERNOON. A SECONDARY SHORTWAVE DIVING DOWN THE BACKSIDE OF THE UPPER TROUGH SUN NIGHT AND MON WILL CONTINUE A CHANCE FOR SHOWERS THROUGH THE DAY MON...ESP ACROSS THE NE PART OF THE FORECAST AREA WHERE LOW LEVEL ONSHORE FLOW IS THE BEST. A TRANSIENT RIDGE OF HIGH PRES MOVING ACROSS MON NIGHT AND TUE WILL BRING A SHORT LIVED RETURN TO DRY WEATHER. .LONG TERM (PREVIOUS DISCUSSION)...TUESDAY NIGHT THROUGH SATURDAY...NEXT LOW PRESSURE SYSTEM APPROACHES MIDWEEK...WITH ACTIVE WEATHER PATTERN CONTINUING THROUGH LATE NEXT WEEK. RAIN MOVES BACK IN WEDNESDAY THROUGH THURSDAY WITH THIS SYSTEM. RIGHT NOW MODELS SHOW SHORTWAVE RIDGING BUILDING IN ON FRIDAY...WHICH SHOULD KEEP MOST OF OUR AREA DRY UNTIL THE NEXT LOW PRESSURE SYSTEM BRINGS MORE RAIN NEXT WEEKEND. -MCCOY && .AVIATION...MAINLY VFR CONDITIONS TO CONTINUE THROUGH THE EVENING AND MUCH OF THE OVERNIGHT PERIOD WITH MID AND HIGH LEVEL CLOUDS IN PLACE. LOW PRES TO APPROACH THE COAST THROUGH SUN...CAUSING CIGS TO GRADUALLY LOWER OVERNIGHT. -SHRA DEVELOPING ALONG THE COAST THIS EVENING. STEADIER RAIN TO SPREAD ONTO THE COAST OVERNIGHT AND INLAND SUNDAY MORNING. COASTAL AREAS LIKELY TO FALL INTO MVFR AROUND SUNRISE. INLAND AREAS SHOULD REMAIN VFR THROUGH SUN MORNING...EXCEPT FOR MVFR CIGS OVER THE OREGON COAST RANGE AND WILLAPA HILLS IN SW WA. MVFR CIGS LIKELY TO MOVE INTO THE INLAND TAF SITES BY EARLY SUNDAY AFTERNOON. THE FRONT SHOULD CLEAR THE REGION BY LATE AFTERNOON...WITH RAIN TAPERING TO SHOWERS AND CONDITIONS GENERALLY IMPROVING TO VFR. KPDX AND APPROACHES...VFR OVERNIGHT INTO SUN AM. VARIABLE MID AND HIGH CLOUDS THROUGH ABOUT 08Z THEN CIGS TO GRADUALLY LOWER. RAIN TO SPREAD IN LATER SUNDAY MORNING...WITH VFR CIGS LIKELY BY AROUND MIDDAY. E WIND TO AFFECT ERN APPROACHES TO THE TERMINAL THROUGH MID AFTERNOON SUN. WINDS WILL THEN TRANSITION TO S-SW. PYLE && .MARINE...SATELLITE IMAGERY SHOWS IMPRESSIVE-LOOKING LOW PRES SYSTEM NEAR 44N/130W THIS EVENING WITH A CENTRAL PRES NEAR 996 MB. THE LOW AND ASSOCIATED OCCLUDED FRONT WILL APPROACH THE WATERS OVERNIGHT AND SUN. THE LOW IS EXPECTED TO BE AROUND 125 NM W OF NEWPORT BY AROUND 15Z. EVEN THOUGH THE LOW WILL BE GRADUALLY FILLING...EXPECT A BURST OF FAIRLY STRONG WINDS AHEAD OF THIS SYSTEM...PARTICULARLY OVER THE CENTRAL OREGON WATERS. THE LATEST FCST MODELS...INCLUDING THE 00Z NAM AND 03Z RAP ARE TRENDING STRONGER WITH THE WINDS OVERNIGHT INTO SUN MORNING OUT AHEAD OF THE LOW. HAVE ISSUED A GALE WARNING WITH THIS FCST PACKAGE FOR THE CENTRAL OREGON WATERS...WHICH MAY SEE GUSTS TO 35 TO 40 KT DEVELOP OVERNIGHT. WILL KEEP A SMALL CRAFT ADVISORY FOR WINDS FOR THE NORTHERN WATERS...ALTHOUGH THERE IS THE POTENTIAL FOR THEM TO SEE OCCASIONAL GUSTS TO 35 KT AS WELL. THE STRONGEST WINDS WILL BE OVER THE OUTER WATERS DURING THIS EVENT. THERE IS AN OFFSHORE COMPONENT TO THE FLOW... WHICH SHOULD SHELTER THE INNER WATERS UNTIL THE LOW COMES CLOSED NEAR TO THE INNER WATERS SUN MORNING. THE LOW WILL PUSH ONSHORE OVER THE S WASHINGTON COAST SUN EVENING...BUT A REINFORCING DISTURBANCE WILL MOVE IN FROM THE NORTH...KEEPING GUSTY W-NW WINDS CONTINUING THROUGH MUCH OF SUN NIGHT. AFTER A LULL MON AFTERNOON THROUGH TUE NIGHT...ANOTHER SPLITTING SYSTEM IS FORECAST TO IMPACT THE WATERS WED. SHOULD SEE SMALL CRAFT ADVISORY SPEEDS WITH THIS SYSTEM AS WELL. INCREASING W-SW SWELL ASSOCIATED WITH THE WINDS FROM THIS SYSTEM TO MOVE INTO THE WATERS OVERNIGHT AND SUN. SEAS WILL LIKELY REACH 12-15 FT BY SUN AFTERNOON...GRADUALLY SUBSIDING SUNDAY NIGHT AND MONDAY AS THE LOW CONTINUES TO FILL AND MOVE ONSHORE. SEAS SHOULD DROP BELOW 10 FT LATER MON AND TUE...BUT THE NEXT SYSTEM TUE NIGHT/WED SHOULD BRING ANOTHER ROUND OF SEAS IN THE 12-15 FT RANGE. PYLE && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT MONDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT MONDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR WINDS FROM 5 AM TO 9 PM PDT SUNDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 5 AM TO 9 PM PDT SUNDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM. GALE WARNING UNTIL 11 AM PDT SUNDAY FOR WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM. GALE WARNING FROM 2 AM TO 2 PM PDT SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO 6 PM PDT SUNDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
820 AM EDT SUN OCT 25 2015 .SYNOPSIS... A COLD FRONT WILL SOUTHEAST OF THE REGION TODAY...FOLLOWED BY DRIER AIR WHICH WILL LAST INTO TUESDAY. AFTER A QUIET START TO THE NEW WORK WEEK...THE PATTERN WILL TURN UNSETTLED FOR THE MID TO LATE WEEK PERIOD. && .NEAR TERM /THROUGH TONIGHT/... 12Z UPDATE...MINOR CHANGES TO NEAR TERM FCST BASED ON LATEST TEMP AND RADAR TRENDS. THE SYNOPTIC COLD FRONT APPEARS TO BE JUST WEST OF FIG-BGM-AFJ LINE. EXPECT LITTLE MORE THAN AN ISOLD -SHRA OVER THE LAUREL HIGHLANDS INTO THE CENTRAL MTNS IN THE NEXT FEW HOURS. PREVIOUS DISCUSSION... MESO ANAL INDICATES THE CORE OF THE LOW LEVEL JET IS NOW MOVING UP INTO NY AND NEW ENGLAND. RADAR SHOWS THE STEADIEST RAIN SIMILARLY MOVING OUT OF THE FORECAST AREA. HRRR HAS THE SHOWERS CONTINUING TO DWINDLE AND RACE EAST OVER THE NEXT SEVERAL HOURS. THE ACTUAL COLD FRONT LOOKS LIKE IT JUST MOVED THROUGH BRADFORD...ON SCHEDULE TO BE MOVING THROUGH THE LOWER SUSQ VALLEY EARLY THIS MORNING...LEADING TO A FAST DROP OFF IN RAIN CHANCES. I LEFT IN A SMALL CHANCE OF SHOWERS EARLY...MAINLY OVER THE SOUTHERN TIER...BUT THE BULK OF THE DAY WILL BE DRY WITH A MIX OF SUN AND CLOUDS DEVELOPING. A DEVELOPING NW...DOWNSLOPE FLOW WILL HELP PUSH TEMPS INTO THE MID 60S OVER THE SE. HIGHS OVER THE NW WILL BE COOLER...IN THE LOWER TO MID 50S. FAIR SKIES WILL PREVAIL OVERNIGHT AS A BIG HIGH BUBBLE SLIDES THROUGH NORTHERN PA. LIGHT WINDS AND CLEAR SKIES WILL LEAD TO A CHILLY NIGHT GENERALLY IN THE 30S...WHICH WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR LATE OCTOBER. && .SHORT TERM /MONDAY/... THE HIGH WILL BRING A BRIGHT DAY FOR MONDAY. HIGHS WILL BE A TAD BELOW SEASONAL NORMS RANGING FROM NEAR 50 OVER THE NW TO NEAR 60 OVER THE SE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE WILL MIGRATE EASTWARD FROM THE GREAT LAKES REGION INTO THE INTERIOR NORTHEAST EARLY IN THE PERIOD...WITH DRY WX EXPECTED TO LAST AT LEAST THROUGH TUESDAY. MODELS ARE NOW IN BETTER AGREEMENT IN THE TIMING OF THE RETURN MOISTURE ASSOCIATED WITH THE DIGGING NORTHERN PLAINS ENERGY WHICH IS MADE TO CAPTURE THE TROPICAL MOISTURE CURRENTLY SUPPORTING THE HEAVY RAIN OVER THE GULF STATES. A STORM IS EXPECTED TO FORM OVER THE LOWER MISS VALLEY...TRACKING ALMOST STRAIGHT NORTH THROUGH THE CENTRAL GR LAKES THROUGH MID WEEK. THE TRAILING COLD FRONT IS MADE TO SWING THROUGH THE LOCAL AREA LATER WED OR WED EVENING. PWATS OF 1.25 - 1.75"...OR 1-3 STD DEV ABOVE NORMAL ARE SURGED NORTH ON A STRONG SSE LOW LEVEL JET THAT IS TIMED INTO THE REGION DURING THE DAY WEDNESDAY. GEFS SHOWS A HIGH PROB OF AT LEAST 1 INCH OF RAIN/24 HOURS WITH THE OPERATIONAL GFS AND ECMWF ALSO PAINTING QPF IN EXCESS OF 1 INCH. ENSEMBLES INDICATE AMOUNTS GREATER THAN 2 INCHES IN 24 HOURS ARE NOT LIKELY...PROBABLY DUE TO THE SPEED OF THE SYSTEM AS IT CHUGS THROUGH THE AREA. A COLDER POST-FRONTAL CYCLONIC FLOW WILL GRIP THE REGION THU-FRI WITH LAKE ENHANCED SHOWERS LIKELY OVER NW PA. HIGH PRESSURE SHOULD RETURN FAIR/DRY WX CONDITIONS TO THE AREA BY NEXT WEEKEND. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A WIDE VARIATION IN CONDITIONS AS OF 7 AM. MOST OF THE SHOWERS NOW EAST OF THE AREA. WAS CONCERN ABOUT THE INVERSION MAKING IT HARD TO CLEAR OUT TODAY...BUT GIVEN HOW DRY THE AIRMASS IS COMING INTO THE AREA AND THAT THE CLOUDS OFF LAKE MI ARE BREAKING UP NOW ACROSS MUCH OF MI...EXPECT VFR CONDITIONS ACROSS THE AREA LATER THIS MORNING/EARLY THIS AFT. 12Z TAFS SENT. OUTLOOK... MON-TUE...NO SIG WX EXPECTED. WED...RAIN/LOW CIGS POSSIBLE. THU...WINDY WITH SOME SHOWERS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE/STEINBUGL SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
735 AM EDT SUN OCT 25 2015 .SYNOPSIS... A COLD FRONT WILL SOUTHEAST OF THE REGION TODAY...FOLLOWED BY DRIER AIR WHICH WILL LAST INTO TUESDAY. AFTER A QUIET START TO THE NEW WORK WEEK...THE PATTERN WILL TURN UNSETTLED FOR THE MID TO LATE WEEK PERIOD. && .NEAR TERM /THROUGH TONIGHT/... MESO ANAL INDICATES THE CORE OF THE LOW LEVEL JET IS NOW MOVING UP INTO NY AND NEW ENGLAND. RADAR SHOWS THE STEADIEST RAIN SIMILARLY MOVING OUT OF THE FORECAST AREA. HRRR HAS THE SHOWERS CONTINUING TO DWINDLE AND RACE EAST OVER THE NEXT SEVERAL HOURS. THE ACTUAL COLD FRONT LOOKS LIKE IT JUST MOVED THROUGH BRADFORD...ON SCHEDULE TO BE MOVING THROUGH THE LOWER SUSQ VALLEY EARLY THIS MORNING...LEADING TO A FAST DROP OFF IN RAIN CHANCES. I LEFT IN A SMALL CHANCE OF SHOWERS EARLY...MAINLY OVER THE SOUTHERN TIER...BUT THE BULK OF THE DAY WILL BE DRY WITH A MIX OF SUN AND CLOUDS DEVELOPING. A DEVELOPING NW...DOWNSLOPE FLOW WILL HELP PUSH TEMPS INTO THE MID 60S OVER THE SE. HIGHS OVER THE NW WILL BE COOLER...IN THE LOWER TO MID 50S. FAIR SKIES WILL PREVAIL OVERNIGHT AS A BIG HIGH BUBBLE SLIDES THROUGH NORTHERN PA. LIGHT WINDS AND CLEAR SKIES WILL LEAD TO A CHILLY NIGHT GENERALLY IN THE 30S...WHICH WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR LATE OCTOBER. && .SHORT TERM /MONDAY/... THE HIGH WILL BRING A BRIGHT DAY FOR MONDAY. HIGHS WILL BE A TAD BELOW SEASONAL NORMS RANGING FROM NEAR 50 OVER THE NW TO NEAR 60 OVER THE SE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE WILL MIGRATE EASTWARD FROM THE GREAT LAKES REGION INTO THE INTERIOR NORTHEAST EARLY IN THE PERIOD...WITH DRY WX EXPECTED TO LAST AT LEAST THROUGH TUESDAY. MODELS ARE NOW IN BETTER AGREEMENT IN THE TIMING OF THE RETURN MOISTURE ASSOCIATED WITH THE DIGGING NORTHERN PLAINS ENERGY WHICH IS MADE TO CAPTURE THE TROPICAL MOISTURE CURRENTLY SUPPORTING THE HEAVY RAIN OVER THE GULF STATES. A STORM IS EXPECTED TO FORM OVER THE LOWER MISS VALLEY...TRACKING ALMOST STRAIGHT NORTH THROUGH THE CENTRAL GR LAKES THROUGH MID WEEK. THE TRAILING COLD FRONT IS MADE TO SWING THROUGH THE LOCAL AREA LATER WED OR WED EVENING. PWATS OF 1.25 - 1.75"...OR 1-3 STD DEV ABOVE NORMAL ARE SURGED NORTH ON A STRONG SSE LOW LEVEL JET THAT IS TIMED INTO THE REGION DURING THE DAY WEDNESDAY. GEFS SHOWS A HIGH PROB OF AT LEAST 1 INCH OF RAIN/24 HOURS WITH THE OPERATIONAL GFS AND ECMWF ALSO PAINTING QPF IN EXCESS OF 1 INCH. ENSEMBLES INDICATE AMOUNTS GREATER THAN 2 INCHES IN 24 HOURS ARE NOT LIKELY...PROBABLY DUE TO THE SPEED OF THE SYSTEM AS IT CHUGS THROUGH THE AREA. A COLDER POST-FRONTAL CYCLONIC FLOW WILL GRIP THE REGION THU-FRI WITH LAKE ENHANCED SHOWERS LIKELY OVER NW PA. HIGH PRESSURE SHOULD RETURN FAIR/DRY WX CONDITIONS TO THE AREA BY NEXT WEEKEND. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A WIDE VARIATION IN CONDITIONS AS OF 7 AM. MOST OF THE SHOWERS NOW EAST OF THE AREA. WAS CONCERN ABOUT THE INVERSION MAKING IT HARD TO CLEAR OUT TODAY...BUT GIVEN HOW DRY THE AIRMASS IS COMING INTO THE AREA AND THAT THE CLOUDS OFF LAKE MI ARE BREAKING UP NOW ACROSS MUCH OF MI...EXPECT VFR CONDITIONS ACROSS THE AREA LATER THIS MORNING/EARLY THIS AFT. 12Z TAFS SENT. OUTLOOK... MON-TUE...NO SIG WX EXPECTED. WED...RAIN/LOW CIGS POSSIBLE. THU...WINDY WITH SOME SHOWERS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
546 AM EDT SUN OCT 25 2015 .SYNOPSIS... A COLD FRONT WILL SOUTHEAST OF THE REGION TODAY...FOLLOWED BY DRIER AIR WHICH WILL LAST INTO TUESDAY. AFTER A QUIET START TO THE NEW WORK WEEK...THE PATTERN WILL TURN UNSETTLED FOR THE MID TO LATE WEEK PERIOD. && .NEAR TERM /THROUGH TONIGHT/... MESO ANAL INDICATES THE CORE OF THE LOW LEVEL JET IS NOW MOVING UP INTO NY AND NEW ENGLAND. RADAR SHOWS THE STEADIEST RAIN SIMILARLY MOVING OUT OF THE FORECAST AREA. HRRR HAS THE SHOWERS CONTINUING TO DWINDLE AND RACE EAST OVER THE NEXT SEVERAL HOURS. THE ACTUAL COLD FRONT LOOKS LIKE IT JUST MOVED THROUGH BRADFORD...ON SCHEDULE TO BE MOVING THROUGH THE LOWER SUSQ VALLEY EARLY THIS MORNING...LEADING TO A FAST DROP OFF IN RAIN CHANCES. I LEFT IN A SMALL CHANCE OF SHOWERS EARLY...MAINLY OVER THE SOUTHERN TIER...BUT THE BULK OF THE DAY WILL BE DRY WITH A MIX OF SUN AND CLOUDS DEVELOPING. A DEVELOPING NW...DOWNSLOPE FLOW WILL HELP PUSH TEMPS INTO THE MID 60S OVER THE SE. HIGHS OVER THE NW WILL BE COOLER...IN THE LOWER TO MID 50S. FAIR SKIES WILL PREVAIL OVERNIGHT AS A BIG HIGH BUBBLE SLIDES THROUGH NORTHERN PA. LIGHT WINDS AND CLEAR SKIES WILL LEAD TO A CHILLY NIGHT GENERALLY IN THE 30S...WHICH WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR LATE OCTOBER. && .SHORT TERM /MONDAY/... THE HIGH WILL BRING A BRIGHT DAY FOR MONDAY. HIGHS WILL BE A TAD BELOW SEASONAL NORMS RANGING FROM NEAR 50 OVER THE NW TO NEAR 60 OVER THE SE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE WILL MIGRATE EASTWARD FROM THE GREAT LAKES REGION INTO THE INTERIOR NORTHEAST EARLY IN THE PERIOD...WITH DRY WX EXPECTED TO LAST AT LEAST THROUGH TUESDAY. MODELS ARE NOW IN BETTER AGREEMENT IN THE TIMING OF THE RETURN MOISTURE ASSOCIATED WITH THE DIGGING NORTHERN PLAINS ENERGY WHICH IS MADE TO CAPTURE THE TROPICAL MOISTURE CURRENTLY SUPPORTING THE HEAVY RAIN OVER THE GULF STATES. A STORM IS EXPECTED TO FORM OVER THE LOWER MISS VALLEY...TRACKING ALMOST STRAIGHT NORTH THROUGH THE CENTRAL GR LAKES THROUGH MID WEEK. THE TRAILING COLD FRONT IS MADE TO SWING THROUGH THE LOCAL AREA LATER WED OR WED EVENING. PWATS OF 1.25 - 1.75"...OR 1-3 STD DEV ABOVE NORMAL ARE SURGED NORTH ON A STRONG SSE LOW LEVEL JET THAT IS TIMED INTO THE REGION DURING THE DAY WEDNESDAY. GEFS SHOWS A HIGH PROB OF AT LEAST 1 INCH OF RAIN/24 HOURS WITH THE OPERATIONAL GFS AND ECMWF ALSO PAINTING QPF IN EXCESS OF 1 INCH. ENSEMBLES INDICATE AMOUNTS GREATER THAN 2 INCHES IN 24 HOURS ARE NOT LIKELY...PROBABLY DUE TO THE SPEED OF THE SYSTEM AS IT CHUGS THROUGH THE AREA. A COLDER POST-FRONTAL CYCLONIC FLOW WILL GRIP THE REGION THU-FRI WITH LAKE ENHANCED SHOWERS LIKELY OVER NW PA. HIGH PRESSURE SHOULD RETURN FAIR/DRY WX CONDITIONS TO THE AREA BY NEXT WEEKEND. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... MOST OF THE SHOWERS NOW EAST OF THE AREA. WAS CONCERN ABOUT THE INVERSION MAKING IT HARD TO CLEAR OUT TODAY...BUT GIVEN HOW DRY THE AIRMASS IS COMING INTO THE AREA AND THAT THE CLOUDS OFF LAKE MI ARE BREAKING UP NOW ACROSS MUCH OF MI...EXPECT VFR CONDITIONS ACROSS THE AREA LATER THIS MORNING/EARLY THIS AFT. OUTLOOK... MON-TUE...NO SIG WX EXPECTED. WED...RAIN/LOW CIGS POSSIBLE. THU...WINDY WITH SOME SHOWERS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
426 AM EDT SUN OCT 25 2015 .SYNOPSIS... A COLD FRONT WILL SOUTHEAST OF THE REGION TODAY...FOLLOWED BY DRIER AIR WHICH WILL LAST INTO TUESDAY. AFTER A QUIET START TO THE NEW WORK WEEK...THE PATTERN WILL TURN UNSETTLED FOR THE MID TO LATE WEEK PERIOD. && .NEAR TERM /THROUGH TONIGHT/... MESO ANAL INDICATES THE CORE OF THE LOW LEVEL JET IS NOW MOVING UP INTO NY AND NEW ENGLAND. RADAR SHOWS THE STEADIEST RAIN SIMILARLY MOVING OUT OF THE FORECAST AREA. HRRR HAS THE SHOWERS CONTINUING TO DWINDLE AND RACE EAST OVER THE NEXT SEVERAL HOURS. THE ACTUAL COLD FRONT LOOKS LIKE IT JUST MOVED THROUGH BRADFORD...ON SCHEDULE TO BE MOVING THROUGH THE LOWER SUSQ VALLEY EARLY THIS MORNING...LEADING TO A FAST DROP OFF IN RAIN CHANCES. I LEFT IN A SMALL CHANCE OF SHOWERS EARLY...MAINLY OVER THE SOUTHERN TIER...BUT THE BULK OF THE DAY WILL BE DRY WITH A MIX OF SUN AND CLOUDS DEVELOPING. A DEVELOPING NW...DOWNSLOPE FLOW WILL HELP PUSH TEMPS INTO THE MID 60S OVER THE SE. HIGHS OVER THE NW WILL BE COOLER...IN THE LOWER TO MID 50S. FAIR SKIES WILL PREVAIL OVERNIGHT AS A BIG HIGH BUBBLE SLIDES THROUGH NORTHERN PA. LIGHT WINDS AND CLEAR SKIES WILL LEAD TO A CHILLY NIGHT GENERALLY IN THE 30S...WHICH WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR LATE OCTOBER. && .SHORT TERM /MONDAY/... THE HIGH WILL BRING A BRIGHT DAY FOR MONDAY. HIGHS WILL BE A TAD BELOW SEASONAL NORMS RANGING FROM NEAR 50 OVER THE NW TO NEAR 60 OVER THE SE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE WILL MIGRATE EASTWARD FROM THE GREAT LAKES REGION INTO THE INTERIOR NORTHEAST EARLY IN THE PERIOD...WITH DRY WX EXPECTED TO LAST AT LEAST THROUGH TUESDAY. MODELS ARE NOW IN BETTER AGREEMENT IN THE TIMING OF THE RETURN MOISTURE ASSOCIATED WITH THE DIGGING NORTHERN PLAINS ENERGY WHICH IS MADE TO CAPTURE THE TROPICAL MOISTURE CURRENTLY SUPPORTING THE HEAVY RAIN OVER THE GULF STATES. A STORM IS EXPECTED TO FORM OVER THE LOWER MISS VALLEY...TRACKING ALMOST STRAIGHT NORTH THROUGH THE CENTRAL GR LAKES THROUGH MID WEEK. THE TRAILING COLD FRONT IS MADE TO SWING THROUGH THE LOCAL AREA LATER WED OR WED EVENING. PWATS OF 1.25 - 1.75"...OR 1-3 STD DEV ABOVE NORMAL ARE SURGED NORTH ON A STRONG SSE LOW LEVEL JET THAT IS TIMED INTO THE REGION DURING THE DAY WEDNESDAY. GEFS SHOWS A HIGH PROB OF AT LEAST 1 INCH OF RAIN/24 HOURS WITH THE OPERATIONAL GFS AND ECMWF ALSO PAINTING QPF IN EXCESS OF 1 INCH. ENSEMBLES INDICATE AMOUNTS GREATER THAN 2 INCHES IN 24 HOURS ARE NOT LIKELY...PROBABLY DUE TO THE SPEED OF THE SYSTEM AS IT CHUGS THROUGH THE AREA. A COLDER POST-FRONTAL CYCLONIC FLOW WILL GRIP THE REGION THU-FRI WITH LAKE ENHANCED SHOWERS LIKELY OVER NW PA. HIGH PRESSURE SHOULD RETURN FAIR/DRY WX CONDITIONS TO THE AREA BY NEXT WEEKEND. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... AREA OF SHOWERS...SOME HEAVY...WILL MOVE OUT OF THE AREA BY EARLY TO MID MORNING. IT WILL TAKE A FEW HOURS AFTER THIS TO SEE VFR CONDITIONS TO RETURN TO THE AREA. SOME MINOR CHANGES MADE TO 06Z TAFS. EARLIER DISCUSSION BELOW. APPROACHING COLD FRONT IS SPREADING RAIN AND LOWERING CIGS ACROSS CENTRAL PA LATE THIS EVENING. LATEST MDL OUTPUT SUPPORTS A CONTINUATION OF LIFR/IFR CIGS AT KBFD THRU 07Z. ELSEWHERE...EXPECT MVFR CONDS OVR THE CENTRAL MTNS BTWN 03Z-07Z AND EXPECT A TRANSITION FROM VFR TO MVFR ACROSS THE SE AIRFIELDS /KMDT AND KLNS/ BY ARND 08Z. COLD FRONT WILL PUSH SE ACROSS CENTRAL PA BTWN 07Z-14Z. EXPECT SOME MODEST IMPROVEMENT AT KBFD AFTER 07Z...AS NW FLOW PULLS DRIER AIR IN BEHIND THE FRONT. AT KJST...A WIND SHIFT FROM SW TO NW WITH FROPA TYPICALLY BRINGS A TEMPORARY REDUCTION IN CIGS...DUE TO OROGRAPHIC LIFTING. THEREFORE...EXPECT A PERIOD OF IFR CIGS AT KJST BEHIND FRONT LATE TONIGHT. FURTHER EAST...EXPECT GRADUALLY IMPROVING CIGS SUN MORNING...AS FRONT CLEARS THE AREA AND DRIER NW FLOW TAKES HOLD. EXAMINATION OF LATEST MDL SOUNDINGS SUGGEST MUCH OF CENTRAL PA WILL REMAIN JUST BELOW LLWS CRITERIA TONIGHT. HOWEVER...HAVE INCLUDED LLWS FOR A SEVERAL HOUR PERIOD AT KBFD/KJST/KIPT...COINCIDENT WITH PASSAGE OF STRONGEST WINDS ALOFT. HIGH PRES WILL BUILD INTO THE REGION FROM THE NW LATER SUNDAY...LIKELY RESULTING IN WIDESPREAD VFR CONDS BY SUN AFTN. OUTLOOK... MON-TUE...NO SIG WX EXPECTED. WED...RAIN/LOW CIGS POSSIBLE. THU...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
330 PM CDT SUN OCT 25 2015 .DISCUSSION... THE MAIN HEADLINE OF THIS FORECAST PACKAGE IS THE CONTINUED RAINS EXPECTED TO PERSIST THROUGH THE EARLY PORTIONS OF THIS WEEK IN ASSOCIATED WITH THE REMNANTS OF PATRICIA AND EVENTUAL FRONTAL INTERACTION... CURRENTLY...A STRONG AND COMPACT SURFACE LOW WAS LOCATED IN THE NORTHERN GULF OF MEXICO WHICH WAS SLOWLY MOVING NORTH WITH TIME. ZONAL BUT BROADLY CYCLONIC FLOW AT 500 MB PREVAILED ACROSS MUCH OF THE NORTHERN CONUS AS A STRONG S/W WAS CURRENTLY MOVING ONSHORE IN THE PACIFIC NORTHWEST. A LARGE PRECIP SHIELD ASSOCIATED WITH SLOW ISENTROPIC ASCENT ENCOMPASSED MUCH OF THE MID-SOUTH WITH THE EXCEPTION OF EXTREME NORTHEAST ARKANSAS AND THE MO BOOTHEEL. THROUGH THE REST OF THE AFTERNOON...PERSISTENT LIGHT TO OCCASIONALLY MODERATE RAINFALL SHOULD CONTINUE. THE HEAVIEST PRECIP TOTALS ARE EXPECTED ACROSS PORTIONS OF NORTHERN MISSISSIPPI IN CLOSER PROXIMITY TO THE STRONGER...MORE FOCUSED LIFT. TEMPERATURES ARE NOT EXPECTED TO MOVE MUCH THROUGH THE OVERNIGHT PERIOD AS THE DIURNAL CURVE REMAINS NEARLY FLAT. IN FACT...MANY LOCATIONS DID NOT GET OUT OF THE MID TO UPPER 50S TODAY...WELL BELOW GUIDANCE. THE UPPER LEVEL PATTERN EVOLUTION WILL GO A LONG WAY IN DETERMINING HOW THE DURATION OF THE PRECIPITATION EVENT PLAYS OUT THROUGH EARLY THIS WEEK. THE ECMWF AND GFS BOTH AGREE THAT A STRONG CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE NORTHEAST US ON MONDAY...WHICH SHOULD STUNT THE NORTHWARD PROGRESSION OF THE GULF LOW PRESSURE. DRY AIR ASSOCIATED WITH THE HIGH TO THE NORTH WILL PREVENT PRECIP FROM SPREADING TO NORTHERNMOST PORTIONS OF THE MID-SOUTH. THERE WILL LIKELY BE A STRONG GRADIENT IN PRECIP TOTALS ON MONDAY. AS THE HIGH PRESSURE SYSTEM EVENTUALLY EXITS...IT SHOULD ALLOW THE LOW PRESSURE TO RESUME ITS PROGRESS NORTH WITH RAIN CHANCES INCREASING MONDAY NIGHT AND TUESDAY. BY LATE TUESDAY...A SHORTWAVE MOVING ACROSS THE NORTHERN PLAINS WILL SWEEP A FRONTAL BOUNDARY THROUGH THE CENTRAL US AND EVENTUALLY THE MID-SOUTH. EVENTUALLY THE SURFACE LOW SHOULD PHASE WITH THE NORTHERN STREAM INDUCING CYCLOGENESIS ACROSS THE GREAT LAKES LATER IN THE WEAK. THE INTERACTION WITH THE SURFACE LOW EJECTING AND FRONTAL BOUNDARY SUGGEST THE PRECIPITATION WILL REMAIN LIKELY THROUGH AT LEAST EARLY WEDNESDAY MORNING. AS THE FRONT PUSHES THROUGH THE MID-SOUTH...PRECIP CHANCES DECREASE FROM WEST TO EAST DURING THE DAY ON WEDNESDAY. COOLER AND DRIER AIR IS EXPECTED TO MOVE IN FOR THE THURSDAY AND FRIDAY PERIOD. IN THE LONG-TERM...THE UPPER LEVEL FLOW REGIME AMPLIFIES AND BECOMES MUCH MORE ACTIVE. AGREEMENT EXISTS THAT A LARGE AND DEEP UPPER LEVEL TROUGH WILL DIG EQUATORWARD LATE IN THE WEEK...INDUCING RETURN FLOW ACROSS THE SOUTHERN PLAINS. THE SLOW MOVING NATURE OF THE LOW SUGGESTS THAT PRECIP WILL BE SLOW TO DEVELOP EAST. FOR THIS REASON...PRECIP CHANCES HAVE BEEN KEPT REASONABLY LOW UNTIL UNCERTAINTY REGARDING THE EVOLUTION OF THE SYSTEM DECREASES. TVT && .AVIATION... 18Z TAFS IFR/MVFR CIGS WILL PREVAIL THROUGH THE NEXT 24 HOURS...AS MOIST TROPICAL AIR OVERRIDES A NEARLY SATURATED AND COOLER LOW LEVEL AIRMASS. PERSISTENT RAINFALL WILL SERVE TO REINFORCE THE LOW LEVEL MOIST INVERSION. AFTER 00Z...EXPECT RAINFALL TO CONTRACT TO THE SOUTH/SOUTHWEST NEARER THE APPROACHING TROPICAL LOW. SOME IMPROVEMENT IN CIGS TO MVFR/ISOLATED VFR NOT OUT OF THE QUESTION...THOUGH CONFIDENCE IS MARGINAL. 15Z HRRR SHOWS IFR CIGS LIKELY TO PERSIST INTO EARLY EVENING...WHILE NAM BUFR SOUNDINGS DEPICT IMPROVEMENT TO MVFR WITH DIMINISHING RAINFALL. RAIN CHANCES FOR MEM WILL RAMP UP SIGNIFICANTLY JUST AFTER THE 18Z TAF VALID PERIOD...WITH OUTER BOUND RAINFALL AROUND THE NORTHERN PERIPHERY OF THE TROPICAL LOW. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
316 PM EDT SUN OCT 25 2015 .SHORT TERM...(TONIGHT THROUGH TUESDAY)...SOME PACKING OF 850 MB ISOTHERMS OVER ERN KY AND W VA...WITH COLD AIR ADVECTION INTO WISE AND RUSSELL COUNTIES OF SW VA THIS AFTERNOON. THIS HAS CAUSED LOW CEILINGS AND POOR VISBY AT LONESOME PINE (LNP). HOWEVER...THE ACTUAL WEAK SURFACE COLD FRONT STILL APPEARED TO BE DISSIPATING ACROSS ERN KY...WITH LATEST RAP MODEL RUN NOT PRODUCING MUCH ADDITIONAL RAINFALL UNTIL VERY LATE TONIGHT. ADJUSTED POP AND WEATHER GRIDS TO BETTER REFLECT THIS MOST PLAUSIBLE SCENARIO. OTHERWISE...RAIN LOOKS TO INCREASE DURING THE DAY MONDAY...WITH HIGHEST POPS THEN NEEDED THROUGH MONDAY NIGHT INTO TUESDAY...AS THE LOW PRESSURE CENTER TRACKS NORTH FROM THE LA-MS COAST. THE APPROACHING LOW PRESSURE WILL CREATE E-SE DOWNSLOPE LOW LEVEL FLOW AS INDICATED IN THE RAIN AMOUNT AND TEMP GRIDS FOR THOSE PERIODS. MONITORING THE POSSIBILITY OF A MINOR MOUNTAIN WAVE EVENT...WHILE RAIN AMOUNTS DURING THE SHORT TERM SHOULD NOT POSE ANY CONCERNS. THE COOLER MAV/GFS MOS MAX TEMPS LOOKED BETTER FOR AREAS WHERE DOWNSLOPE FLOW IS NOT A FACTOR. CLOSELY FOLLOWED THE SIMILAR MOS MINS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)...WITH THE CHANGING SEASONS THE UPPER PATTERN WILL CONTINUE TO BECOME MORE AMPLIFIED INCREASING THE FREQUENCY OF STORM SYSTEM PASSAGE ACROSS THE SOUTHEASTERN U.S. ONE SUCH SYSTEM WILL BE MOVING ACROSS THE SOUTHERN APPALACHIANS TUESDAY NIGHT INTO WEDNESDAY WITH A WARM AND DEEP SOUTHERLY COMPONENT TO THE MEAN FLOW AHEAD OF AN APPROACHING UPPER TROUGH. THE MODELS STILL INDICATE JUST ENOUGH INSTABILITY ON WEDNESDAY FOR THE POSSIBILITY OF CONVECTION SO KEPT A CHANCE FOR THIS ACTION IN THE FORECAST FOR THE DAYTIME GROUP WEDNESDAY. A COLD FRONT BUILDS EAST OF THE APPALACHIAN RISE EARLY ON THURSDAY BRINGING AN END TO THE RAINFALL. A DRY PERIOD FOLLOWS THURSDAY NIGHT THROUGH FRIDAY NIGHT BUT IN THE EVER STRENGTHENING WESTERLIES...ANOTHER AMPLIFIED SYSTEM BUILDS IN FOR THE WEEKEND. KEPT A SLIGHT CHANCE OF SHOWERS GOING ON SATURDAY AS A WARM AND MOIST SOUTHERLY FLOW GRADUALLY STRENGTHENS ACROSS THE REGION. HOWEVER...IT STILL APPEARS THE BEST CHANCE OF SHOWERS MAY BE ON SUNDAY AS THE SYSTEM SURFACE COLD FRONT APPROACHES. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 60 64 56 62 / 60 80 80 100 KNOXVILLE MCGHEE TYSON AIRPORT, TN 56 64 54 63 / 40 70 80 80 OAK RIDGE, TN 55 64 55 61 / 30 70 80 90 TRI CITIES AIRPORT, TN 53 63 51 61 / 30 60 70 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG/TH
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1259 PM CDT SUN OCT 25 2015 .UPDATE... UPDATED FOR 18Z AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... /ISSUED 1054 AM CDT SUN OCT 25 2015/ UPDATE... TWO RELATIVELY MAJOR CHANGES WERE MADE TO THE FORECAST WITH THIS UPDATE. THE FIRST WAS TO LOWER TEMPERATURES SIGNIFICANTLY ACROSS PORTIONS OF NORTHEAST ARKANSAS WHERE DIURNAL CURVES HAVE BEEN NEARLY FLAT THIS MORNING. ONLY EXPECT HIGHS IN THE UPPER 50S ACROSS THIS REGION...PROGRESSING TO THE LOWER 60S ALONG THE I40 CORRIDOR. THE OTHER CHANGE WAS TO REMOVE ANY MENTION OF THUNDER AREA-WIDE. THERE SIMPLY IS NOT ENOUGH ELEVATED INSTABILITY TO SUPPORT CARRYING THIS THROUGH THE NEAR-TERM PORTION OF THE FORECAST PERIOD. OTHERWISE...FORECAST LOOKS GOOD AS LIGHT TO OCCASIONALLY MODERATE RAINFALL WILL CONTINUE THROUGH THE DAY. FALL HAS OFFICIALLY ARRIVED. TVT PREV DISCUSSION... /ISSUED 306 AM CDT SUN OCT 25 2015/ DISCUSSION... SKIES ARE MOSTLY CLOUDY ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING WITH TEMPERATURES RANGING FROM THE MID 50S TO UPPER 60S. A FAIRLY LARGE AREA OF SHOWERS IS PUSHING NORTH ACROSS NORTH MISSISSIPPI AND INTO SOUTHWEST TENNESSEE. THE COLD FRONT WHICH MOVED THROUGH AREA EARLIER ON SATURDAY IS NOW JUST EAST AND SOUTH OF THE FORECAST AREA. THIS FRONT WILL NOT MOVE MUCH FURTHER EAST OR SOUTH TODAY. THIS WILL MEAN MORE SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED ACROSS THE ENTIRE FORECAST AREA. WITH COLDER AIR IN PLACE OVER THE REGION BEHIND THE FRONT TEMPERATURES WILL BE MUCH COOLER THAN THE LAST FEW DAYS WITH HIGHS TODAY MAINLY IN THE 60S TO AROUND 70 DEGREES. LOW PRESSURE HAS DEVELOP ALONG THE TEXAS GULF COAST. THIS LOW WILL TRACK NORTH TODAY AND TONIGHT WILL BE OVER SOUTHWEST LOUISIANA. THIS LOW WILL HELP TO SPREAD MORE MOISTURE INTO THE REGION WITH MORE SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED TONIGHT MAINLY OVER NORTH MISSISSIPPI. TEMPERATURES WILL BE A LITTLE COOLER THAN THEY HAVE BEEN WITH LOWS MONDAY MORNING IN THE LOWER 50S TO LOWER 60S. ON MONDAY...THE SURFACE LOW WILL DRIFT SLOWLY NORTHEAST INTO EASTERN LOUISIANA. AS A RESULT MORE RAIN WILL SPREAD THROUGH THE FORECAST AREA. TEMPERATURES WILL REMAIN ON THE COOL SIDE WITH HIGHS IN THE MID 60S TO AROUND 70 DEGREES. RAINY WEATHER WILL CONTINUE INTO MONDAY NIGHT AS WELL. ON TUESDAY...THE LOW WILL START TO LIFT NORTH INTO WESTERN MISSISSIPPI WITH MORE SHOWERS EXPECTED ACROSS THE FORECAST AREA. BY TUESDAY NIGHT THE LOW WILL LIFT NORTH THROUGH THE FORECAST AREA SO MORE RAIN IS EXPECTED. BY WEDNESDAY A COLD FRONT WILL START TO SWEEP THROUGH THE REGION BRINGING ONE MORE ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS. HIGH PRESSURE WILL START TO BUILD INTO THE REGION BY LATE WEDNESDAY NIGHT SO THE RAINY PERIOD WE WILL BE EXPERIENCING WILL COME TO AN END. HIGH PRESSURE WILL REMAIN OVER THE EASTERN U.S. FOR THURSDAY AND FRIDAY BRINGING DRY CONDITIONS WITH TEMPERATURES SLIGHTLY BELOW NORMAL. A NEW STORM SYSTEM WILL DEVELOP OVER CENTRAL TEXAS AND MOVE NORTHEAST ON SATURDAY. THIS MEAN ANOTHER PERIOD OF WET WEATHER STARTING FRIDAY NIGHT AND CONTINUING INTO SATURDAY. ARS && .AVIATION... 18Z TAFS IFR/MVFR CIGS WILL PREVAIL THROUGH THE NEXT 24 HOURS...AS MOIST TROPICAL AIR OVERRIDES A NEARLY SATURATED AND COOLER LOW LEVEL AIRMASS. PERSISTENT RAINFALL WILL SERVE TO REINFORCE THE LOW LEVEL MOIST INVERSION. AFTER 00Z...EXPECT RAINFALL TO CONTRACT TO THE SOUTH/SOUTHWEST NEARER THE APPROACHING TROPICAL LOW. SOME IMPROVEMENT IN CIGS TO MVFR/ISOLATED VFR NOT OUT OF THE QUESTION...THOUGH CONFIDENCE IS MARGINAL. 15Z HRRR SHOWS IFR CIGS LIKELY TO PERSIST INTO EARLY EVENING...WHILE NAM BUFR SOUNDINGS DEPICT IMPROVEMENT TO MVFR WITH DIMINISHING RAINFALL. RAIN CHANCES FOR MEM WILL RAMP UP SIGNIFICANTLY JUST AFTER THE 18Z TAF VALID PERIOD...WITH OUTER BOUND RAINFALL AROUND THE NORTHERN PERIPHERY OF THE TROPICAL LOW. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
937 AM EDT SUN OCT 25 2015 .DISCUSSION...RAIN THIS MORNING REMAINS WELL TO OUR NORTH ALONG THE WEAKENING COLD FRONT. THE LATEST RAP MODEL RUN SHOWS THIS FRONTAL BOUNDARY DISSIPATING...AND THE NAM MODEL DEPICTS THIS AS WELL. SO... WILL UPDATE THE FORECAST GRIDS SHORTLY AND LOWER RAIN CHANCES TO 20 PERCENT FOR SE TN/SW NC...TO AROUND 40 TO 50 PERCENT ACROSS NRN PLATEAU AND SW VA COUNTIES. THESE LOWER RAIN CHANCES MAY AFFECT MAX TEMPS FOR TODAY...WHICH WILL BE TWEAKED AS NEEDED BASED ON LATEST HOURLY TEMPS AND DEW POINT TEMPS. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 72 59 65 56 / 40 50 80 80 KNOXVILLE MCGHEE TYSON AIRPORT, TN 68 55 65 55 / 40 40 70 80 OAK RIDGE, TN 66 55 65 54 / 40 40 70 80 TRI CITIES AIRPORT, TN 66 52 63 50 / 50 40 60 70 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
729 AM CDT SUN OCT 25 2015 .UPDATE... PER LATEST HRRR MODEL TRENDS...HAVE UPDATED SUITE OF FORECAST PRODUCTS TO RAISE POPS SLIGHTLY ACROSS W/SW PORTIONS OF MID STATE WHERE RAINFALL/RAINFALL POTENTIAL MOST PROMINENT. ALSO TWEAKED HRLY TEMP...DEWPOINT...WIND DIRECTIONS/SPEED GRIDS. REMAINDER OF FORECAST CONTINUES TO BE ON TRACK. && .PREV DISCUSSION... 12Z AVIATION UPDATE... LIGHT -SHRA WILL CONTINUE TO DEVELOP AND SPREAD ACROSS AIRPORTS THIS MORNING INTO THE AFTERNOON BEFORE TAPERING OFF PER LATEST HRRR MODEL RUNS. MVFR CIGS ARE ANTICIPATED INTO THE AFTERNOON WITH IMPROVEMENT TO VFR AT CKV/BNA BY LATE AFTERNOON BUT CONTINUED MVFR AT CSV. LIGHT NORTH TO NORTHEAST WINDS ARE EXPECTED THROUGH THE TAF PERIOD. SHAMBURGER && $$ 31
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
632 PM CDT MON OCT 26 2015 .UPDATE...UPDATE FOR 00Z AVIATION BELOW. && .AVIATION...VFR CONDITIONS THROUGH THE NEXT 30 HOURS AT TAF SITES. CAN NOT RULE OUT PATCHY GROUND FOG EAST OF I-35 AROUND SUNRISE TUE MORNING...CLOSER TO WHERE HIGHER RAINFALL FELL OVER THE WEEKEND. WINDS DIMINISHING QUICKLY THIS EVENING. A CALM TO WEAK NW-N WIND AROUND 5 KTS EXPECTED OVERNIGHT. SW WIND 5-7 KTS DEVELOPS AT AUS/SAT TUE AFTERNOON AND A S TO SE WIND AT DRT. && .PREV DISCUSSION... /ISSUED 252 PM CDT MON OCT 26 2015/ SHORT TERM (TONIGHT THROUGH TUESDAY)... NO HIGHLIGHTS OR HAZARDS EXPECTED THROUGH THE NEXT FEW DAYS WITH A DRY AIRMASS IN PLACE AS NEAR NORMAL TEMPERATURES ARE EXPECTED. CURRENT WATER VAPOR AND RAP ANALYSIS DEPICT A STRONG CLOSED MID LEVEL LOW TRAVERSING EAST ACROSS THE NORTHERN GULF OF MEXICO AWAY FROM THE REGION. FARTHER UPSTREAM TO THE WEST...A DAMPENED TROUGH IS SHIFTING ACROSS THE INTER-MOUNTAIN WEST THAT WILL EVENTUALLY BRING A WEAK FRONT TOWARDS THE REGION BY MID WEEK. FOR TODAY...WINDY AND WARM TEMPERATURES ARE ONGOING AS A TIGHT PRESSURE GRADIENT EXISTS FROM WEST TO EAST TOWARDS THE AFOREMENTIONED LOW PRESSURE SYSTEM IN THE GULF. WINDS WILL GUST TO 20-25 MPH AT TIMES AS TEMPS MAX OUT IN THE MID 70S TO LOW 80S. WINDS WILL DECREASE OVERNIGHT AS THE LOW PULLS AWAY AND WITH DEWPOINTS EXPECTED IN THE UPPER 40S AND LOW 50S OVERNIGHT WITH CLEARING SKIES...TEMPS WILL DROP INTO THE UPPER 40S IN THE HILL COUNTRY AND LOW TO MID 50S ACROSS THE I-35 CORRIDOR AND COASTAL PLAINS. A NEAR REPEAT OF CONDITIONS IS EXPECTED TOMORROW WITH SLIGHTLY WARMER MAX HIGHS AND LESS CLOUD COVER GIVEN DRIER VERTICAL PROFILES FROM MODEL SOUNDINGS. LONG TERM (WEDNESDAY THROUGH MONDAY)... OUR HAZARD FOCUS THIS PERIOD WILL BE ON FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON AS ANOTHER POTENT STORM SYSTEM WILL APPROACH THE REGION. THE MAIN RISKS AT THIS POINT LOOK TO BE ANOTHER ROUND OF HEAVY RAIN BUT WILL NEED TO MONITOR EVOLUTION FOR OTHER POTENTIAL SEVERE WEATHER HAZARDS. BY MID-WEEK...NORTH WINDS WILL CONTINUE AS A WEAK DRY FRONT MOVES TOWARDS THE REGION DUE TO A WEAK SHORTWAVE TROUGH SHIFTING ACROSS THE SOUTHERN PLAINS. HOWEVER...BY THURSDAY...WINDS WILL BEGIN TO VEER TO THE EAST AND THEN SOUTHEAST AS THE RE-ESTABLISHING OF MOISTURE COMMENCES. A STRONG SIGNAL ACROSS THE ENSEMBLE SUITE OF GLOBAL MODELS INDICATES A POTENT MID-LVL TROUGH MOVING INTO NORTHERN MEXICO BY THURSDAY. THIS FEATURE...ALONG SIDE BROAD TROUGHING OVER THE PLAINS...WILL HELP INDUCE LEE-SIDE SURFACE CYCLOGENESIS THAT WILL AID IN DEEPER SOUTHERLY FLOW. BY MID-DAY FRIDAY...THE TROUGH OVER SOUTHERN ARIZONA WILL HAVE DEEPENED SUBSTANTIALLY TO NEAR 560 DM WHICH IS ABOUT 10DM DEEPER THAN THE PREVIOUS TROUGH THAT IMPACTED THE REGION. HOWEVER...WE WILL HAVE LESS MOISTURE TO WORK WITH THIS UPCOMING WEEKEND VS. THE PAST EVENT WHERE PWATS WERE UPWARDS OF 2.1-2.3" VS. THE PROGGED 1.8-1.9` (BUT STILL GOOD). THESE VALUES WILL STILL BE ADEQUATE ENOUGH FOR HEAVY RAIN AS SET-UP LOOKS TO BE SLIGHTLY STRONGER FORCED. IT IS TOO EARLY TO TELL IF THERE WILL BE MULTIPLE WAVES FRIDAY AFTERNOON AND AGAIN SATURDAY AS A POSSIBLE DRYLINE SURGE OCCURS OR IF IT WILL BE A MORE PROLONGED EVENT LATE FRIDAY INTO MID-DAY SATURDAY. LOOKING AT PROGGED CAPE/SHEAR COMBINATIONS AND SOUNDINGS...HEALTHY PARAMETERS APPEAR TO BE IN PLACE THAT COULD SUGGEST ORGANIZATION FOR A BROKEN QLCS ALONG A POSSIBLE DRYLINE SURGE SATURDAY MORNING TO MID-DAY. ANY ORGANIZATION THAT DOES OCCUR COULD AID IN STRONG WINDS AND POSSIBLY OTHER HAZARDS AS A 90-100 KT JET STREAK WILL SUPPORT STRONG UPPER-LEVEL DIVERGENCE NEAR AND NORTH OF THE REGION. WILL CONTINUE TO MONITOR THE SET-UP FOR OVERALL RAIN ACCUMULATION AMOUNTS AND SEVERE WEATHER HAZARD POSSIBILITIES. THE TIMING OF THE SYSTEM MOVING THROUGH BECOMES MURKY ON SUNDAY WITH EC SLOWER THAN THE PROGRESSIVE GFS. THE UKMET AND GEM FAVOR A SLOWER PATTERN WITH RAIN POSSIBLY LINGERING INTO SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 55 82 60 84 56 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 52 81 55 84 53 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 53 84 57 87 56 / 0 0 0 0 0 BURNET MUNI AIRPORT 51 80 57 79 52 / 0 0 0 0 0 DEL RIO INTL AIRPORT 49 84 58 86 56 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 52 81 57 81 52 / 0 0 0 0 0 HONDO MUNI AIRPORT 49 84 55 88 55 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 54 82 57 85 55 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 55 82 58 85 57 / 0 0 0 0 0 SAN ANTONIO INTL AIRPORT 54 85 60 87 57 / 0 0 0 0 0 STINSON MUNI AIRPORT 54 85 59 88 58 / 0 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...RUNYEN SYNOPTIC/GRIDS...TREADWAY PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
934 AM EDT SUN OCT 25 2015 .SYNOPSIS... A COLD FRONT WILL SLIDE SOUTHEAST INTO THE CAROLINAS BY THIS EVENING. HIGH PRESSURE WEDGES SOUTH ALONG THE EASTERN SLOPES OF THE APPALACHIANS MONDAY AND TUESDAY. THEN A LOW PRESSURE SYSTEM WILL MOVE FROM THE UPPER MISSISSIPPI VALLEY INTO THE NORTHEAST UNITED STATES...PUSHING A COLD FRONT THROUGH THE AREA ON WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 925 AM EDT SUNDAY... COVERAGE OF SHOWERS GREATEST FROM BUCKINGHAM TO AMHERST TO BECKLEY THIS MORNING. THIS ALONG THE FRONT WITH BEST MOISTURE CONVERGENCE AND THETA-E RIDGING OCCURRING...ESPECIALLY IN THE MOUNTAINS. THE 12Z HRRR SHOWS THIS WELL WITH BAND OF SHOWERS SHIFTING SE TOWARD THE MOUNTAIN EMPIRE-NEW RIVER VALLEY-SMITH MTN LAKE- LYNCHBURG CORRIDOR BY MIDDAY-EARLY AFTERNOON. COVERAGE IS NOT GREAT ENOUGH TO GO HIGHER THAN LIKELY...AND WILL TAPER TO SLIGHT TO NO CHANCE TO THE NORTH AND SOUTH OF THIS BAND INTO EARLY AFTERNOON. TEMPERATURES WERE COOLER THAN EARLIER FORECAST...AND BACKED OFF A FEW DEGREES THROUGH MIDDAY ESPECIALLY IN THE PIEDMONT. STILL QUESTION OF HOW MUCH DRIER AIR CAN GAIN HOLD FROM THE NORTH BEFORE SUNSET...WHERE SUNSHINE COULD WARM TEMPS UP SOME AROUND LYNCHBURG TO LEXINGTON...AS WELL AS POSSIBLE BREAKS SHOWING UP IN THE NC PIEDMONT TOWARD DANVILLE. KEPT FORECAST HIGHS RANGING FROM THE LOWER 70S SOUTHEAST TO AROUND 60 OVER THE MOUNTAINS. LATEST MODEL PROJECTION SHOW THE FRONT MOVING INTO NC BY LATE AFTERNOON WITH SHOWERS DIMINISHING. PREVIOUS VALID DISCUSSION... THE SURFACE BOUNDARY WILL PUSH ALL THE WAY THROUGH THE CAROLINAS BUT THE 850 MB FRONT WILL STALL CLOSE TO THE EXTREME SOUTHERN COUNTY WARNING AREA TONIGHT. BY TONIGHT HIGH PRESSURE MOVES EAST INTO PENNSYLVANIA AND NEW YORK WHICH WILL BRING WINDS AROUND TO THE NORTHEAST. THE BEST COVERAGE TONIGHT WILL BE IN THE SOUTHWEST COUNTY WARNING AREA WITH ONLY LIMITED PRECIPITATION FOR THE REST OF THE FORECAST AREA. MODELS INDICATED A SHARP NORTHERN EDGE OF THE PRECIPITATION AND CLOUD COVER ALTHOUGH WITH SOME DIFFERENCES IN THE LOCATION OF THAT NORTHERN EDGE. HAVE BROUGHT THE NORTHERN EDGE OF CLOUD COVER INTO THE NORTHERN COUNTY WARNING AREA TONIGHT. CLOUDS WILL ALSO LIMIT TEMPERATURE DROP TONIGHT SO HAVE RAISED MINIMUM TEMPERATURES. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... AS OF 430 AM EDT SUNDAY... A STRONG AREA OF HIGH PRESSURE...CENTERED OVER NEW YORK...WILL WEDGE SOUTH INTO GEORGIA-SOUTH CAROLINA MONDAY. MEANWHILE...REMNANTS OF HURRICANE PATRICIA MOVES INLAND OVER THE SOUTHERN MISSISSIPPI VALLEY. THE WEDGE WILL PUSH IN DRIER COOLER AIR ON NORTHEASTERLY FLOW WHILE TROPICAL MOISTURE ALOFT ADVANCES NORTHWARD. THESE TWO SYSTEM WILL BEGIN TO INTERSECT OVER THE SOUTHERN APPALACHIANS WITH MAINLY AN INCREASE IN CLOUD COVER THROUGH THE DAY. WEAK ISENTROPIC LIFT EDGES INTO THE SOUTHWEST CORNER OF THE COUNTY WARNING AREA BRINGING LIGHT RAIN CHANCES TO THE MOUNTAIN EMPIRE AND NORTH CAROLINA HIGH COUNTY THROUGH THE DAY MONDAY. THE COMBINATION OF CLOUDS AND LIGHT RAIN TO THE SOUTHWEST AND SOME SUN AND COOL AIR TOWARDS THE NORTH...SHOULD KEEP TEMPERATURES FROM PEAKING ABOVE 60F MONDAY. THE FORECAST BECOMES COMPLICATED MONDAY NIGHT AS SHORT WAVES FROM THE REMNANTS OF HURRICANE PATRICIA TRACK NORTHWARD. ONE WAVE WITH THE BETTER JET DYNAMICS TRACKS OVER THE TENNESSEE VALLEY...HEADING TO THE OHIO VALLEY ON TUESDAY. A SECOND WEAKER WAVE TRACKS NORTHEAST ALONG THE BLUE RIDGE AND OVER THE WEDGE. EVEN THOUGH THIS WAVE WILL HAVE TROPICAL ORIGINS...THIS WARM RAIN WILL ENHANCE THE WEDGE MAKING TUESDAY A VERY COLD DAY WITH TEMPERATURES NOT MAKING IT OUT OF THE 40S. DYNAMICS WITH THIS SHORT WAVE AND ABUNDANT MOISTURE WILL BRING A PROLONG PERIOD OF RAIN TO THE AREA TUESDAY INTO WEDNESDAY. MODELS ARE SUGGESTING UPWARDS OF 3 INCHES OF RAIN IS POSSIBLE. HOWEVER...THIS TROPICAL SHORT WAVE IS TRACKING OVER A WEDGE AND LIKE THE OCT 4TH EVENT...MODELS MAY BE OVER DONE WITH RAINFALL AMOUNTS. MODELS ARE PROJECTING A 35-50KT EASTERLY JET WHICH COULD ENHANCE RAINFALL AMOUNTS...ESPECIALLY ALONG THE BLUE RIDGE. HOWEVER...THE WEDGE WILL REMAIN THICK OVER THE AREA AND THESE STRONGER WINDS WILL NOT MIX DOWN. MODEL ARE ALSO DISPLAYING A DEEPLY SATURATED SOUNDING WHICH IS ANOTHER HINT THAT THESE WINDS WILL NOT MIX DOWN. FOR THIS PACKAGE...WE ARE FORECASTING AN INCH OF RAIN FOR THE MAJORITY OF THE AREA WITH UP TO TWO INCHES ALONG THE BLUE RIDGE. WITH OUR RECENT DRY PERIOD...WE SHOULD BE TO HANDLE ALL THIS RAIN WITH NO PROBLEM. HYDRO CONCERNS TUESDAY INTO WEDNESDAY MAYBE HEIGHTEN IF THE WEDGE MANAGES TO ERODE AND ALLOW THE POTENTIAL FOR HIGHER RAINFALL RATES TO OCCUR. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 330 PM EDT SATURDAY... THE COLD FRONT WILL PASS ACROSS OUR AREA WEDNESDAY NIGHT AND EARLY THURSDAY...BRINGING AN END TO RAINFALL ACROSS OUR AREA ASIDE FROM UPSLOPE SHOWERS OVER THE MOUNTAINS THAT WILL PERSIST THROUGH THURSDAY AFTERNOON. HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST...CONTROLLING OUR WEATHER PATTERN INTO SATURDAY WITH DOWNSLOPE WEST NORTHWEST WINDFLOW. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... AS OF 720 AM EDT SUNDAY... HIGH CONFIDENCE OF AREAS WITH MVFR CEILINGS AND VISIBILITIES AS A BAND OF SHOWERS ASSOCIATED WITH A COLD FRONT CROSSES THROUGH THE FORECAST AREA TODAY. MODELS WERE SIMILAR WITH THE TIMING OF THE FRONT AND PRECIPITATION...WITH THE WINDS SHIFTING TO THE NORTHWEST BEHIND THE BOUNDARY. LOWER CONFIDENCE WITH OCCURRENCE AND AREAL COVERAGE OF IFR OR LOWER CEILINGS WITH THE PRECIPITATION. MODELS ALSO SHOWED A SHARP NORTHERN EDGE TO THE CLOUDS AND PRECIPITATION AS THE FRONT BECOMES ORIENTED WEST TO EAST ACROSS THE CAROLINAS TONIGHT. AS HIGH PRESSURE BUILDS IN TONIGHT NORTH OF THE FRONT...WINDS WILL TURN TO THE NORTHEAST. THE MOST LIKELY LOCATION TO HAVE MVFR CEILINGS TONIGHT WILL BE ACROSS SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA...INCLUDING KBLF AND KBCB AFTER MIDNIGHT. EXTENDED DISCUSSION... THE PROBABILITY OF PRECIPITATION AND WIDESPREAD IFR CONDITIONS INCREASES ON MONDAY AND TUESDAY WITH A STRONGER WEDGE. MVFR/IFR CEILINGS AND VISIBILITIES ARE EXPECTED ALONG AND AHEAD OF A COLD FRONT ON WEDNESDAY. GUSTY WINDS BUT DRIER WEATHER IS EXPECTED BEHIND THE FRONT ON THURSDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/WP NEAR TERM...AMS/WP SHORT TERM...RCS LONG TERM...NF AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
142 AM EDT SUN OCT 25 2015 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION OVERNIGHT BEFORE SLIDING SOUTH AND WEAKENING BY EARLY SUNDAY. A WEAK COLD FRONT WORKS EAST FROM THE MIDWEST AND THROUGH THE AREA BY LATE SUNDAY. HIGH PRESSURE WEDGES SOUTH ALONG THE EASTERN SLOPES OF THE APPALACHIANS MONDAY AND TUESDAY FOLLOWED BY A WETTER STORM SYSTEM BY MIDWEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 840 PM EDT SATURDAY... EVENING SOUNDINGS SHOW MOISTURE CONTINUING TO INCREASE ALOFT ACROSS THE REGION AS DEEPER SOUTHWEST FLOW DEVELOPS IN ADVANCE OF THE COLD FRONT BACK ACROSS THE MIDWEST. HOWEVER STILL QUITE A TONGUE OF MID LEVEL DRY AIR SEEN WITHIN THE 85H-7H INVERSION...WITH SURFACE DEWPOINTS REMAINING QUITE DRY PER THE LEFTOVER RESIDUAL WEDGE FROM EARLIER TODAY. THIS HAS ACTED TO LIMIT THE EASTWARD ADVANCE OF SPOTTY SHOWERS/SPRINKLES THAT WERE CROSSING THE WESTERN MOUNTAINS IN ADVANCE OF THE MAIN LOBE OF LIFT/SHOWERS ALONG THE ACTUAL FRONT JUST WEST OF THE OHIO RIVER. LATEST SHORT TERM MODELS CONTINUE TO DISAGREE ON JUST HOW FAR EAST THIS MAIN BAND OF SHOWERS WILL MAKE IT WITH OVERALL ONLY THE HRRR BRINGING COVERAGE EAST TO AT LEAST THE BLUE RIDGE OVERNIGHT. THUS PLAN TO KEEP SOME HIGHER LIKELY POPS GOING FAR WEST AFTER MIDNIGHT PER CURRENT PROXIMITY OF THE SHOWERS...WHILE ONLY GOING WITH SPOTTY SHOWERS/SPRINKLES EARLY ON...THEN MORE CHANCE NATURE COVERAGE ELSEWHERE OVER THE WESTERN/NORTHERN SECTIONS BY DAYBREAK. SOLID MID DECK CANOPY SHOULD KEEP LOWS FROM FALLING TOO MUCH UNLESS SHOWERS/EVAPORATION INCREASE SO STAYING MOSTLY IN THE 50S FOR LOWS AT THIS POINT. SUNDAY...AS THE FRONT MOVES SOUTHEAST...THE MOISTURE POOLS BEST ACROSS THE SOUTHERN APPALACHIANS WITH MORE SCATTERED NATURE FURTHER NORTHEAST. BY LATE SUNDAY AFTERNOON MOST OF THE SHOWERS WILL BE CONFINED SOUTH OF NC/VA BORDER AND FURTHER SOUTH WITH THE FRONT REACHING AN NORFOLK VA TO GSP LINE. THE MODELS START TO BRING JUST ENOUGH DRY AIR INTO THE ALLEGHANY HIGHLANDS TO BUCKINGHAM COUNTY CORRIDOR...OR ROUGHLY NORTH OF I- 64...HIGHWAY 60 TO RETURN SOME SUN BY 4 PM SUNDAY AFTERNOON. MOST OVERALL WILL STAY CLOUDY. HIGHS SHOULD CLOSE TO SEASONAL NORMS WITH LOWER 60S WEST TO UPPER 60SS OUT EAST AND THE NC FOOTHILLS. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... AS OF 300 PM EDT SATURDAY... HIGH PRESSURE OVER THE EASTERN GREAT LAKES SUNDAY EVENING WILL CONTINUE TO SHIFT TOWARD NEW ENGLAND...WHILE ALSO SPREADING SOUTHWARD ACROSS THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE APPALACHIANS. WILL START THE EVENING WITH SPOTTY OCCASIONAL RAIN ACROSS THE SOUTHERN HALF OF OUR AREA AS WEAK DISTURBANCES RIDE ALONG THE FRONT JUST SOUTH OF OUR AREA...HOWEVER RAINFALL WILL GRADUALLY BECOME MORE WIDESPREAD OVERNIGHT ACROSS THE MOUNTAINS AS WINDS SHIFT EAST NORTHEASTERLY...INCREASING THE UPSLOPE COMPONENT AS THE HIGH PRESSURE WEDGE BUILDS IN. FOR MONDAY AND MONDAY NIGHT...HIGH PRESSURE WILL REMAIN SITUATED ACROSS OUR AREA...MAINTAINING A COOL EAST NORTHEAST UPSLOPE WINDFLOW. AN AREA OF DEEP LOW PRESSURE ALONG THE GULF COAST WILL GRADUALLY LIFT NORTHWARD THROUGH THE DAY...RADIATING DEEP GULF MOISTURE INTO THE TENNESSEE VALLEY AND ALONG THE APPALACHIAN CHAIN. AS SUCH...BELIEVE RAINFALL WILL REMAIN SPOTTY ON MONDAY...MAINLY AFFECTING THE MOUNTAINS...BUT WILL GRADUALLY INCREASE IN COVERAGE MONDAY NIGHT AS THE AREA OF LOW PRESSURE ADVANCES NORTHWARD. HIGH PRESSURE WILL REMAIN FIRMLY WEDGED ON TUESDAY AND TUESDAY NIGHT...ALBEIT WEAKENING AS THE DAY WEARS ON...WHILE LOW PRESSURE WILL CONTINUE IT NORTHWARD JOG UP THE MISSISSIPPI RIVER VALLEY. WHILE GULF MOISTURE WILL CONTINUE TO OVERRUN THE COOL HIGH PRESSURE ACROSS OUR AREA...BRINGING WIDESPREAD RAINFALL THROUGH THE DAY AND NIGHT...THE AXIS OF HEAVIEST RAIN WILL REMAIN WEST OF THE APPALACHIAN DIVIDE...OUTSIDE OF OUR AREA. THEREFORE...THE MOST LIKELY LOCATIONS FOR HEAVY RAIN WILL BE ALONG THE BLUE RIDGE AND AGAINST OTHER EAST FACING SLOPES...WHERE THE UPSLOPE FLOW WILL LOCALLY ENHANCE RAINFALL INTENSITY. BELIEVE RAINFALL AMOUNTS THROUGH TUESDAY NIGHT WILL RANGE FROM AROUND ONE HALF INCH ACROSS THE SOUTHSIDE...TO A LITTLE MORE THAN AN INCH ACROSS THE MOUNTAINS...WITH LOCALLY TWO TO THREE INCHES ALONG THE BLUE RIDGE PARKWAY AND OTHER PROMINENT EAST FACING SLOPES. CONSIDERING HOW DRY OUR AREA HAS BEEN OVER THE PAST WEEK OR TWO...DO NOT BELIEVE THESE RAINFALL AMOUNTS WILL CAUSE MORE THAN ISOLATED MINOR FLOODING ISSUES. HIGH PRESSURE WEDGING AND RAINFALL THROUGH THE PERIODS WILL MAINTAIN TEMPERATURES WHICH ARE BELOW NORMAL FOR THE END OF OCTOBER. AFTERNOON HIGHS WILL RANGE FROM THE UPPER 40S TO THE UPPER 50S AREAWIDE...WHILE OVERNIGHT LOWS WILL HOLD MAINLY IN THE 40S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 330 PM EDT SATURDAY... BY WEDNESDAY...THE LOW PRESSURE WILL BE NEAR THE GREAT LAKES... PUSHING A COLD FRONT TOWARD OUR AREA FROM THE WEST. HIGH PRESSURE WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS WILL CONTINUE TO WEAKEN...ALLOWING WINDS TO GRADUALLY SHIFT SOUTHERLY FOR OUR AREA. WILL SEE RAIN SHOWERS CONTINUE THROUGH THE DAY...POSSIBLY WITH A RUMBLE OF THUNDER OR TWO IN THE WEST AS BETTER INSTABILITY APPROACHES OUR WESTERN BORDER AHEAD OF THE COLD FRONT. THE COLD FRONT WILL PASS ACROSS OUR AREA WEDNESDAY NIGHT AND EARLY THURSDAY...BRINGING AN END TO RAINFALL ACROSS OUR AREA ASIDE FROM UPSLOPE SHOWERS OVER THE MOUNTAINS THAT WILL PERSIST THROUGH THURSDAY AFTERNOON. HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST...CONTROLLING OUR WEATHER PATTERN INTO SATURDAY WITH DOWNSLOPE WEST NORTHWEST WINDFLOW. && .AVIATION /05Z SUNDAY THROUGH THURSDAY/... AS OF 120 AM EDT SUNDAY... CEILINGS WERE VFR EARLY THIS MORNING BUT WILL CONTINUE TO LOWER THROUGH 12Z/8AM. WIDELY SCATTERED LIGHT SHOWERS WILL HELP SATURATE LOWER LEVELS OF THE ATMOSPHERE. EXPECT CEILINGS OVER THE MOUNTAINS TO REACH MVFR LEVELS BETWEEN 10Z/6AM AND 13Z/9AM. MEDIUM CONFIDENCE THAT CEILINGS WILL REMAIN VFR EAST OF THE BLUE RIDGE. A COLD FRONT FROM EASTERN OHIO TO WESTERN TENNESSEE WILL MOVE EAST TODAY. AS THE FRONT PASSES WINDS WILL TURN TO THE WEST THEN NORTHWEST. BY 00Z/8PM THE FRONT WILL BE IN NORTH CAROLINA AND WINDS WILL BE FROM THE NORTHEAST. SCATTERED SHOWERS WILL CONTINUE ALONG AND AHEAD OF THE FRONT TODAY. BEST PROBABILITY OF MVFR CEILINGS AND VISIBILITIES WILL BE WITH THE FRONT...AND ONCE THE FRONT PROGRESSES FAR ENOUGH SOUTHEAST...CONDITIONS WILL IMPROVE. EXTENDED DISCUSSION... THE PROBABILITY OF PRECIPITATION AND WIDESPREAD IFR CONDITIONS INCREASES ON MONDAY AND TUESDAY WITH A STRONGER WEDGE. MVFR/IFR CEILINGS AND VISIBILITIES ARE EXPECTED ALONG AND AHEAD OF A COLD FRONT ON WEDNESDAY. GUSTY WINDS BUT DRIER WEATHER IS EXPECTED BEHIND THE FRONT ON THURSDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/JH/WP NEAR TERM...JH/WP SHORT TERM...NF LONG TERM...NF AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1213 PM CDT SUN OCT 25 2015 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 329 AM CDT SUN OCT 25 2015 MESSY PATTERN SETTING UP OVER THE UPPER MIDWEST AS THE FLOW ALOFT HAS BECOME WEST TO NORTHWEST. ONE SHORT WAVE TROUGH CURRENTLY COMING OUT OF NORTH DAKOTA INTO NORTHERN MINNESOTA WAS GENERATING SOME RADAR RETURNS AHEAD OF IT. THE 25.05Z RUNS OF THE HRRR AND CR-HRRR WEAKEN THESE RETURNS AND DISSIPATE THEM THIS MORNING BEFORE THEY REACH THE FORECAST AREA. SURFACE OBSERVATIONS IN THE VICINITY OF THESE RETURNS DO NOT INDICATE ANY RAIN IS REACHING THE SURFACE...SO FOR NOW...WILL NOT INCLUDE ANY RAIN OR SPRINKLES IN THE FORECAST FOR THIS MORNING. WATER VAPOR SATELLITE SHOWS THE NEXT SHORT WAVE TROUGH IS OVER SOUTHERN ALBERTA. THIS WAVE WILL MOVE SOUTHEAST AND ACROSS THE UPPER MIDWEST TONIGHT THROUGH MONDAY. BOTH THE 25.00Z NAM AND GFS INDICATE THE PV ADVECTION IN THE 500-300 MB LAYER SHOULD BE VERY WEAK AND STAY TO THE NORTH ACROSS NORTHERN MINNESOTA AND LAKE SUPERIOR. THIS WAVE DOES LOOK TO PUSH A WEAK COLD FRONT INTO THE AREA WITH A BAND OF WEAK FRONTOGENESIS IN THE 1000-700 MB LAYER DEVELOPING THIS AFTERNOON AND THEN REMAINS IN PLACE THROUGH MONDAY FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN. THERE SHOULD ALSO BE A BAND OF WEAK QG CONVERGENCE IN THE 1000-500 MB LAYER OF THE SAME GENERAL AREA. THE ISENTROPIC UP GLIDE ON THE 290K SURFACE STARTS TO SPREAD IN LATE THIS AFTERNOON AND THEN PEAKS ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA OVERNIGHT IN THE 3 TO 5 UBAR/S RANGE. ALL OF THE HI-RES MESO MODELS KEEP THE AREA DRY TODAY AS DOES THE 25.00Z NAM AND ECMWF WHILE THE GFS SPREADS SOME LIGHT RAIN IN BY LATE AFTERNOON. WILL SHOW A VERY SMALL RAIN CHANCE LATE THIS AFTERNOON ACROSS THE VERY FAR NORTHERN SECTIONS AND THEN INCREASE THESE INTO THE 40 TO 60 PERCENT RANGE FOR THE OVERNIGHT. THESE RAIN CHANCES WILL THEN PERSIST INTO MONDAY MORNING BEFORE MOVING PAST THE AREA MONDAY AFTERNOON. .LONG TERM...(TUESDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN OCT 25 2015 ALMOST ALL THE MODELS HAVE NOW CONVERGED TO THE SOLUTION FIRST SHOWN BY THE ECMWF FOR THE UPCOMING MID WEEK SYSTEM. A SHORT WAVE TROUGH COMING ONTO THE PACIFIC NORTHWEST COAST TODAY WILL CONTINUE TO ADVANCE EAST TOWARD THE AREA TUESDAY AND THEN ACROSS THE REGION TUESDAY NIGHT AS A SYSTEM COMING DOWN FROM THE CANADIAN ROCKIES BECOMES A CLOSED SYSTEM AND MOVES SOUTHEAST ACROSS THE UPPER MIDWEST AND GREAT LAKES TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. BOTH THE ECMWF AND GFS SHOW THE LEAD SHORT WAVE TROUGH PRODUCING SOME MODERATE PV ADVECTION IN THE 500-300 MB LAYER TUESDAY NIGHT AND THEN MODERATE TO STRONG PV ADVECTION WEDNESDAY AFTERNOON AND EVENING. THE LEAD SHORT WAVE TROUGH SHOULD CAUSE A SURFACE LOW TO SPIN UP SOMEPLACE OVER IOWA OR MISSOURI TUESDAY EVENING WITH THIS THEN MOVING NORTH/NORTHEAST TOWARD LAKE SUPERIOR THROUGH WEDNESDAY IN RESPONSE TO THE STRONGER CLOSED LOW. THE RAIN CHANCES FROM THESE SYSTEMS WILL START COME INTO THE SOUTHERN SECTIONS TUESDAY AFTERNOON AND THEN OVERSPREAD THE ENTIRE AREA TUESDAY NIGHT. THE BEST CHANCE FOR RAIN LOOKS TO BE TUESDAY NIGHT IN THE DEFORMATION AREA WITH THE PASSAGE OF THE SURFACE LOW AND WILL SHOW 60 TO 80 PERCENT CHANCES FROM WEST TO EAST. STILL DECENT RAIN CHANCES INTO WEDNESDAY AND THE SOME LINGERING CHANCES FOR WEDNESDAY NIGHT INTO TUESDAY. STILL SOME UNCERTAINTY ON WHAT THE PRECIPITATION TYPE WILL BE ON THE BACK SIDE OF THIS SYSTEM. 925 AND 850 MB TEMPERATURES LOOK TO COOL ENOUGH TO SUPPORT ICE MAINTAINING ITSELF INTO THE LOWER LEVELS OF THE ATMOSPHERE WHILE FORECAST SOUNDINGS SUGGEST SURFACE TEMPERATURES MAY BE TOO WARM AND THE PRECIPITATION MAY BE ALL RAIN. BECAUSE OF THIS UNCERTAINTY AND TO MAINTAIN AGREEMENT WITH NEIGHBORING OFFICES...WILL SHOW A RAIN/SNOW MIX POSSIBLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 1ZZ MONDAY AFTERNOON) ISSUED AT 1213 PM CDT SUN OCT 25 2015 MAIN MOISTURE AXIS AND FORCING/LIFT WILL BE NORTH OF THE TAF SITES THIS PERIOD...WITH LOWER CIGS AND ANY SHRA MAINLY ACROSS CENTRAL/ NORTHERN MN AND NORTHERN WI. FURTHER SOUTH ACROSS THE TAF SITES THE MOISTURE WILL MAINLY BE MID LEVEL WITH CLOUDS/CIGS AROUND THE 10K FT LEVEL. THESE CLOUDS TONIGHT EXPECTED TO LIMIT ANY LATE NIGHT/EARLY MORNING BR/FG...AND LEFT TAFS AS P6SM LATE TONIGHT/EARLY MON MORNING. WEAKER GRADIENTS THRU TONIGHT/MON MORNING...FOR SOUTH TO SOUTHEAST WINDS MOSTLY IN THE 5 TO 10KT RANGE THIS PERIOD. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM....04 AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
555 AM CDT SUN OCT 25 2015 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 329 AM CDT SUN OCT 25 2015 MESSY PATTERN SETTING UP OVER THE UPPER MIDWEST AS THE FLOW ALOFT HAS BECOME WEST TO NORTHWEST. ONE SHORT WAVE TROUGH CURRENTLY COMING OUT OF NORTH DAKOTA INTO NORTHERN MINNESOTA WAS GENERATING SOME RADAR RETURNS AHEAD OF IT. THE 25.05Z RUNS OF THE HRRR AND CR-HRRR WEAKEN THESE RETURNS AND DISSIPATE THEM THIS MORNING BEFORE THEY REACH THE FORECAST AREA. SURFACE OBSERVATIONS IN THE VICINITY OF THESE RETURNS DO NOT INDICATE ANY RAIN IS REACHING THE SURFACE...SO FOR NOW...WILL NOT INCLUDE ANY RAIN OR SPRINKLES IN THE FORECAST FOR THIS MORNING. WATER VAPOR SATELLITE SHOWS THE NEXT SHORT WAVE TROUGH IS OVER SOUTHERN ALBERTA. THIS WAVE WILL MOVE SOUTHEAST AND ACROSS THE UPPER MIDWEST TONIGHT THROUGH MONDAY. BOTH THE 25.00Z NAM AND GFS INDICATE THE PV ADVECTION IN THE 500-300 MB LAYER SHOULD BE VERY WEAK AND STAY TO THE NORTH ACROSS NORTHERN MINNESOTA AND LAKE SUPERIOR. THIS WAVE DOES LOOK TO PUSH A WEAK COLD FRONT INTO THE AREA WITH A BAND OF WEAK FRONTOGENESIS IN THE 1000-700 MB LAYER DEVELOPING THIS AFTERNOON AND THEN REMAINS IN PLACE THROUGH MONDAY FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN. THERE SHOULD ALSO BE A BAND OF WEAK QG CONVERGENCE IN THE 1000-500 MB LAYER OF THE SAME GENERAL AREA. THE ISENTROPIC UP GLIDE ON THE 290K SURFACE STARTS TO SPREAD IN LATE THIS AFTERNOON AND THEN PEAKS ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA OVERNIGHT IN THE 3 TO 5 UBAR/S RANGE. ALL OF THE HI-RES MESO MODELS KEEP THE AREA DRY TODAY AS DOES THE 25.00Z NAM AND ECMWF WHILE THE GFS SPREADS SOME LIGHT RAIN IN BY LATE AFTERNOON. WILL SHOW A VERY SMALL RAIN CHANCE LATE THIS AFTERNOON ACROSS THE VERY FAR NORTHERN SECTIONS AND THEN INCREASE THESE INTO THE 40 TO 60 PERCENT RANGE FOR THE OVERNIGHT. THESE RAIN CHANCES WILL THEN PERSIST INTO MONDAY MORNING BEFORE MOVING PAST THE AREA MONDAY AFTERNOON. .LONG TERM...(TUESDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN OCT 25 2015 ALMOST ALL THE MODELS HAVE NOW CONVERGED TO THE SOLUTION FIRST SHOWN BY THE ECMWF FOR THE UPCOMING MID WEEK SYSTEM. A SHORT WAVE TROUGH COMING ONTO THE PACIFIC NORTHWEST COAST TODAY WILL CONTINUE TO ADVANCE EAST TOWARD THE AREA TUESDAY AND THEN ACROSS THE REGION TUESDAY NIGHT AS A SYSTEM COMING DOWN FROM THE CANADIAN ROCKIES BECOMES A CLOSED SYSTEM AND MOVES SOUTHEAST ACROSS THE UPPER MIDWEST AND GREAT LAKES TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. BOTH THE ECMWF AND GFS SHOW THE LEAD SHORT WAVE TROUGH PRODUCING SOME MODERATE PV ADVECTION IN THE 500-300 MB LAYER TUESDAY NIGHT AND THEN MODERATE TO STRONG PV ADVECTION WEDNESDAY AFTERNOON AND EVENING. THE LEAD SHORT WAVE TROUGH SHOULD CAUSE A SURFACE LOW TO SPIN UP SOMEPLACE OVER IOWA OR MISSOURI TUESDAY EVENING WITH THIS THEN MOVING NORTH/NORTHEAST TOWARD LAKE SUPERIOR THROUGH WEDNESDAY IN RESPONSE TO THE STRONGER CLOSED LOW. THE RAIN CHANCES FROM THESE SYSTEMS WILL START COME INTO THE SOUTHERN SECTIONS TUESDAY AFTERNOON AND THEN OVERSPREAD THE ENTIRE AREA TUESDAY NIGHT. THE BEST CHANCE FOR RAIN LOOKS TO BE TUESDAY NIGHT IN THE DEFORMATION AREA WITH THE PASSAGE OF THE SURFACE LOW AND WILL SHOW 60 TO 80 PERCENT CHANCES FROM WEST TO EAST. STILL DECENT RAIN CHANCES INTO WEDNESDAY AND THE SOME LINGERING CHANCES FOR WEDNESDAY NIGHT INTO TUESDAY. STILL SOME UNCERTAINTY ON WHAT THE PRECIPITATION TYPE WILL BE ON THE BACK SIDE OF THIS SYSTEM. 925 AND 850 MB TEMPERATURES LOOK TO COOL ENOUGH TO SUPPORT ICE MAINTAINING ITSELF INTO THE LOWER LEVELS OF THE ATMOSPHERE WHILE FORECAST SOUNDINGS SUGGEST SURFACE TEMPERATURES MAY BE TOO WARM AND THE PRECIPITATION MAY BE ALL RAIN. BECAUSE OF THIS UNCERTAINTY AND TO MAINTAIN AGREEMENT WITH NEIGHBORING OFFICES...WILL SHOW A RAIN/SNOW MIX POSSIBLE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 554 AM CDT SUN OCT 25 2015 AXIS OF HIGH PRESSURE WAS SITUATED N/S FROM EASTERN MN THROUGH CENTRAL IA EARLY THIS MORNING. LIGHT/CALM WINDS IN THE MISSISSIPI RIVER VALLEY HAS LED TO SOME LIFR RIVER VALLEY FOG AT KLSE. LOOK FOR THIS TO DISSIPATE BY 9 AM. OTHERWISE...WILL BE WATCHING SOME VFR ALTOCUMULUS DRIFTING SOUTHEAST ACROSS CENTRAL MN THIS MORNING...WHICH MAY AFFECT KRST/KLSE FROM TIME TO TIME TODAY. LOOK FOR THIS MID-CLOUD TO THEN INCREASE EARLY THIS EVENING INTO TONIGHT AS A TROUGH OF LOW PRESSURE ROTATES THROUGH THE NORTHERN PLAINS INTO NORTHERN WI. OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH LIGHT SOUTHERLY WINDS OF 10KT OR LESS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
329 AM CDT SUN OCT 25 2015 .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 329 AM CDT SUN OCT 25 2015 MESSY PATTERN SETTING UP OVER THE UPPER MIDWEST AS THE FLOW ALOFT HAS BECOME WEST TO NORTHWEST. ONE SHORT WAVE TROUGH CURRENTLY COMING OUT OF NORTH DAKOTA INTO NORTHERN MINNESOTA WAS GENERATING SOME RADAR RETURNS AHEAD OF IT. THE 25.05Z RUNS OF THE HRRR AND CR-HRRR WEAKEN THESE RETURNS AND DISSIPATE THEM THIS MORNING BEFORE THEY REACH THE FORECAST AREA. SURFACE OBSERVATIONS IN THE VICINITY OF THESE RETURNS DO NOT INDICATE ANY RAIN IS REACHING THE SURFACE...SO FOR NOW...WILL NOT INCLUDE ANY RAIN OR SPRINKLES IN THE FORECAST FOR THIS MORNING. WATER VAPOR SATELLITE SHOWS THE NEXT SHORT WAVE TROUGH IS OVER SOUTHERN ALBERTA. THIS WAVE WILL MOVE SOUTHEAST AND ACROSS THE UPPER MIDWEST TONIGHT THROUGH MONDAY. BOTH THE 25.00Z NAM AND GFS INDICATE THE PV ADVECTION IN THE 500-300 MB LAYER SHOULD BE VERY WEAK AND STAY TO THE NORTH ACROSS NORTHERN MINNESOTA AND LAKE SUPERIOR. THIS WAVE DOES LOOK TO PUSH A WEAK COLD FRONT INTO THE AREA WITH A BAND OF WEAK FRONTOGENESIS IN THE 1000-700 MB LAYER DEVELOPING THIS AFTERNOON AND THEN REMAINS IN PLACE THROUGH MONDAY FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN. THERE SHOULD ALSO BE A BAND OF WEAK QG CONVERGENCE IN THE 1000-500 MB LAYER OF THE SAME GENERAL AREA. THE ISENTROPIC UP GLIDE ON THE 290K SURFACE STARTS TO SPREAD IN LATE THIS AFTERNOON AND THEN PEAKS ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA OVERNIGHT IN THE 3 TO 5 UBAR/S RANGE. ALL OF THE HI-RES MESO MODELS KEEP THE AREA DRY TODAY AS DOES THE 25.00Z NAM AND ECMWF WHILE THE GFS SPREADS SOME LIGHT RAIN IN BY LATE AFTERNOON. WILL SHOW A VERY SMALL RAIN CHANCE LATE THIS AFTERNOON ACROSS THE VERY FAR NORTHERN SECTIONS AND THEN INCREASE THESE INTO THE 40 TO 60 PERCENT RANGE FOR THE OVERNIGHT. THESE RAIN CHANCES WILL THEN PERSIST INTO MONDAY MORNING BEFORE MOVING PAST THE AREA MONDAY AFTERNOON. .LONG TERM...(TUESDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN OCT 25 2015 ALMOST ALL THE MODELS HAVE NOW CONVERGED TO THE SOLUTION FIRST SHOWN BY THE ECMWF FOR THE UPCOMING MID WEEK SYSTEM. A SHORT WAVE TROUGH COMING ONTO THE PACIFIC NORTHWEST COAST TODAY WILL CONTINUE TO ADVANCE EAST TOWARD THE AREA TUESDAY AND THEN ACROSS THE REGION TUESDAY NIGHT AS A SYSTEM COMING DOWN FROM THE CANADIAN ROCKIES BECOMES A CLOSED SYSTEM AND MOVES SOUTHEAST ACROSS THE UPPER MIDWEST AND GREAT LAKES TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. BOTH THE ECMWF AND GFS SHOW THE LEAD SHORT WAVE TROUGH PRODUCING SOME MODERATE PV ADVECTION IN THE 500-300 MB LAYER TUESDAY NIGHT AND THEN MODERATE TO STRONG PV ADVECTION WEDNESDAY AFTERNOON AND EVENING. THE LEAD SHORT WAVE TROUGH SHOULD CAUSE A SURFACE LOW TO SPIN UP SOMEPLACE OVER IOWA OR MISSOURI TUESDAY EVENING WITH THIS THEN MOVING NORTH/NORTHEAST TOWARD LAKE SUPERIOR THROUGH WEDNESDAY IN RESPONSE TO THE STRONGER CLOSED LOW. THE RAIN CHANCES FROM THESE SYSTEMS WILL START COME INTO THE SOUTHERN SECTIONS TUESDAY AFTERNOON AND THEN OVERSPREAD THE ENTIRE AREA TUESDAY NIGHT. THE BEST CHANCE FOR RAIN LOOKS TO BE TUESDAY NIGHT IN THE DEFORMATION AREA WITH THE PASSAGE OF THE SURFACE LOW AND WILL SHOW 60 TO 80 PERCENT CHANCES FROM WEST TO EAST. STILL DECENT RAIN CHANCES INTO WEDNESDAY AND THE SOME LINGERING CHANCES FOR WEDNESDAY NIGHT INTO TUESDAY. STILL SOME UNCERTAINTY ON WHAT THE PRECIPITATION TYPE WILL BE ON THE BACK SIDE OF THIS SYSTEM. 925 AND 850 MB TEMPERATURES LOOK TO COOL ENOUGH TO SUPPORT ICE MAINTAINING ITSELF INTO THE LOWER LEVELS OF THE ATMOSPHERE WHILE FORECAST SOUNDINGS SUGGEST SURFACE TEMPERATURES MAY BE TOO WARM AND THE PRECIPITATION MAY BE ALL RAIN. BECAUSE OF THIS UNCERTAINTY AND TO MAINTAIN AGREEMENT WITH NEIGHBORING OFFICES...WILL SHOW A RAIN/SNOW MIX POSSIBLE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1145 PM CDT SAT OCT 24 2015 RADAR WIND PROFILE IS SHOWING NORTHERLY WINDS FROM 30 TO 35 KTS AT 2000 FT AGL AS OF 25.0430Z. ALTHOUGH THESE WINDS WILL WEAKEN OVERNIGHT AS HIGH PRESSURE BUILDS ACROSS THE REGION...THEY ARE EXPECTED TO REMAIN STRONG ENOUGH (10 TO 15 KTS IN THE LOWEST FEW HUNDRED FEET) TO LIMIT WIDESPREAD VALLEY FOG. IF ANYTHING...WOULD EXPECT A LOW STRATUS DECK TO DEVELOP IN THE VICINITY OF KLSE...SO REMOVED EARLY SUNDAY MORNING VISIBILITY RESTRICTION AND ADDED BCFG WITH A SCATTERED CLOUD DECK AT 200 FT AGL FROM 25.11Z TO 25.13Z. OTHERWISE...EXPECT VFR CONDITIONS AT BOTH TAF AIRFIELDS THROUGH THE PERIOD. WILL SEE SOME INCREASING MID-HIGH LEVEL CLOUDS SUNDAY AFTERNOON AND EVENING WITH LIGHT SOUTHERLY WINDS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1024 PM PDT MON OCT 26 2015 .SYNOPSIS...MILD TEMPERATURES AND DRY WEATHER CONDITIONS WILL PERSIST THROUGH MUCH OF TUESDAY. A PACIFIC SYSTEM WILL THEN BRING A FRONTAL BOUNDARY ACROSS THE REGION LATE TUESDAY INTO WEDNESDAY AND RESULT IN INCREASED CHANCES FOR PRECIPITATION. IN WAKE OF THE SYSTEM...COOLER TEMPERATURES AND BREEZY NORTHERLY WINDS ARE FORECAST THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 8:44 PM PDT MONDAY...SATELLITE IMAGERY SHOWS A LARGE SWATH OF HIGH CLOUDS MOVING OUT AHEAD OF THE COLD FRONT THAT IS CURRENTLY STRETCHED ACROSS THE EASTERN PACIFIC. HIGH CLOUDS STREAMING ACROSS THE FORECAST AREA ARE MAKING IT HARD TO SEE WHAT IS GOING ON AT THE SURFACE. HOWEVER OBSERVATIONS ALONG THE COAST REVEAL LOW CLOUDS PERSIST UNDER A SHALLOW 800 FOOT MARINE LAYER PER THE FORT ORD PROFILER. THE BLANKET OF HIGH CLOUDS ADVECTING OVER THE REGION WILL HAMPER FURTHER DEVELOPMENT OF LOW CLOUDS OVERNIGHT AND THEREFORE KEEP THE LOW CLOUDS CONFINED PRIMARILY TO THE COAST AND LOCALLY INTO COASTAL VALLEYS AND BAYS. COOL OVERNIGHT LOWS ARE EXPECTED ONCE AGAIN WITH TEMPS DIPPING DOWN INTO THE MID 40S TO MID 50S IN MOST LOCATIONS. A GRADUAL COOLING TREND IS FORECAST THROUGH MIDWEEK AS THE COLD FRONT MENTIONED ABOVE MOVES ACROSS THE REGION. MODELS AGREE THAT THE APPROACHING FRONT WILL SPREAD PRECIP ACROSS THE DISTRICT...HOWEVER DISCREPANCIES REMAIN IN THE TIMING AND INTENSITY OF THE PRECIPITATION. THE EURO HAS THE WETTEST AND FASTEST SOLUTION WHILE THE GFS LAGS ONLY SLIGHTLY BEHIND. THE 12Z EURO BRINGS LIGHT PRECIP TO THE NORTH BAY AS EARLY AS 18Z ON TUESDAY. WHILE THIS SEEMS EARLY THE LATEST RUN OF THE HRRR SHOWS LIGHT SHOWERS ACROSS THE NORTHERNMOST PORTION OF SONOMA COUNTY AROUND 16Z TUESDAY. THE EURO SPREADS SHOWERS SOUTHWARD TOWARD THE SAN FRANCISCO BAY BY 00Z WEDNESDAY WITH THE BULK OF THE PRECIP REACHING THE NORTH BAY AROUND 06Z WEDNESDAY. THE GFS SHOWS A FEW SHOWERS TUESDAY EVENING HOWEVER THE MAIN BAND OF PRECIP DOESN`T REACH THE NORTH BAY TIL WELL AFTER 12Z WEDNESDAY. THE CURRENT FORECAST BRINGS IN A CHANCE OF RAIN TO THE NORTH BAY TUESDAY AFTERNOON WITH CHANCES INCREASING AND SPREADING SOUTH TUESDAY EVENING INTO WEDNESDAY. THIS SOLUTIONS SPLITS THE DIFFERENCE AND IS REASONABLE AT THIS TIME. WILL NOT BE MAKING ANY SIGNIFICANT CHANGES TO THE FORECAST PACKAGE. FROM PREVIOUS DISCUSSION...LIGHT RAIN IS FORECAST TO SPREAD OVER THE SAN FRANCISCO BAY AREA LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. WHILE THE PWAT VALUES ARE FORECAST TO PEAK BETWEEN 1.10" AND 1.30" OVER THE REGION...THE AVAILABLE MOISTURE WILL BE MORE LIMITED OVER THE CENTRAL COAST AS THE BOUNDARY PUSHES THROUGH WEDNESDAY MORNING. HAVING SAID THAT...DO EXPECT MOST LOCATIONS WILL RECEIVE SOME RAINFALL FROM THIS SYSTEM. THE GREATEST RAINFALL AMOUNTS FROM TOMORROW NIGHT INTO WEDNESDAY WILL BE OVER THE NORTH BAY WHERE COASTAL RANGES COULD PICK UP BETWEEN 0.25" TO 0.50" FROM THIS SYSTEM. THE REST OF THE BAY AREA COULD PICK UP BETWEEN 0.10" TO 0.25" WITH GENERALLY LESS THAN 0.10" FURTHER SOUTH. AS TYPICAL WITH THESE SYSTEMS...OTHER COASTAL RANGES FROM THE SANTA CRUZ MOUNTAINS SOUTHWARD COULD PICK UP 0.25" IN ISOLATED LOCATIONS. ONCE THE MAIN TROUGH SHIFTS INLAND WEDNESDAY AFTERNOON...LINGERING SHOWERS WILL BE POSSIBLE INTO THE LATE AFTERNOON AS THE UPPER LEVEL JET DEVELOPS ALOFT. BY LATE WEDNESDAY NIGHT...MUCH OF THE MOISTURE AND UPPER LEVEL SUPPORT WILL BE FAR ENOUGH INLAND TO BRING AN END TO PRECIPITATION OVER THE REGION. AS THE MAIN MID/UPPER LEVEL TROUGH SHIFTS INLAND AND DIVES INTO THE FOUR CORNERS REGION THURSDAY INTO FRIDAY...THE SURFACE PRESSURE GRADIENT WILL TIGHTEN OVER THE AREA AND RESULT IN BREEZY TO WINDY CONDITIONS. THE STRONGEST WINDS WILL BE IN THE HIGHER ELEVATIONS WITH GUSTS TO 40 MPH POSSIBLE...WITH GUSTS TO 30 MPH EXPECTED REGION- WIDE. WIND SPEEDS WILL THEN RELAX LATE FRIDAY INTO SATURDAY AS HIGH PRESSURE BUILDS OVER THE REGION. IN ADDITION...THIS WILL ALLOW FOR A SLIGHT WARMING TREND THROUGH SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO SHOW SIGNS OF ANOTHER WEATHER SYSTEM DROPPING DOWN ACROSS OUR REGION THIS UPCOMING SUNDAY INTO NEXT MONDAY. && .AVIATION...AS OF 10:25 PM PDT MONDAY...TRICKY FORECAST WITH LOW CLOUDS INCREASING ACROSS THE AREA WHILE HIGH CLOUDS MOVE OVERHEAD IN ADVANCE OF AN APPROACHING SYSTEM. WILL GO MODERATELY PESSIMISTIC BASED ON CURRENT SURFACE REPORTS. BURN-OFF SLATED FOR AFTER 16Z. WINDS SHOULD NOT BE A FACTOR AND WILL MOSTLY STAY UNDER 10 KT BY 07Z AND CONTINUE THROUGH TUESDAY MORNING. LOW CONFIDENCE. VICINITY OF KSFO...LOW CLOUDS ONLY FORECAST TO DROP SFO DOWN TO MVFR CONDITIONS OVERNIGHT WITH CIGS AROUND 015. WINDS WILL DROP TO UNDER 10 KT AFTER 07Z. VFR RETURNS AFTER 17Z. LOW TO MODERATE CONFIDENCE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...VLIFR TO LIFR CONDITIONS OVERNIGHT WITH CIGS DOWN TO 002 AND VIS OF POTENTIALLY LESS THAN 1/2 SM. WINDS UNDER 10 KT THROUGH TUESDAY MORNING. LOW CONFIDENCE. && .MARINE...AS OF 8:41 PM PDT MONDAY...NORTHWESTERLY WINDS WILL PREVAIL INTO TUESDAY AFTERNOON WITH HIGHER GUSTS LIKELY UNTIL MIDNIGHT. WINDS WILL BECOME SOUTHERLY FOR A SHORT PERIOD OF TIME TUESDAY EVENING AHEAD OF AN APPROACHING STORM SYSTEM. THE FIRST WINTER SWELL OF THE SEASON IS EXPECTED TO ARRIVE ON WEDNESDAY WITH A SWELL OF 18 TO 20 SECONDS. PLEASE BE PREPARED FOR ROUGH CONDITIONS ACROSS THE SAN FRANCISCO AND BREAKING WAVES NEAR OFFSHORE REEFS AND SAND BARS. NORTHERLY WINDS ARE EXPECTED TO STRENGTHEN THURSDAY AS COOL AIR FILTERS IN BEHIND THE DEPARTING STORM SYSTEM. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: CW AVIATION: BELL MARINE: BELL VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
324 AM CDT TUE OCT 27 2015 .SHORT TERM...(Today) ISSUED AT 324 AM CDT TUE OCT 27 2015 08z/3am surface analysis shows ridge of high pressure extending from New England southwestward to the Central Plains...while a 1005mb low continues to spin over Louisiana. Showers from the Gulf Coast low have been slowly spreading northward over the past several hours, but have been encountering a very dry mid/low-level airmass beneath the surface ridge as evidenced by the 00z KILX upper air sounding and current surface dewpoints in the middle to upper 30s across the northern half of the CWA. This dry air has been impeding the northward progress of the precip...with 08z/3am radar imagery and surface obs indicating very light showers/sprinkles confined to locations along and south of a Litchfield to Paris line. HRRR has a decent handle on the current situation and suggests light rain will likely not make it north of the Peoria area until after sunrise. Have therefore cut back PoPs early this morning, especially across the far N/NW CWA where dry air will delay precip onset. Once the airmass moistens sufficiently and an upper-level trough approaching from the west provides increasing synoptic lift, rain will become widespread across the entire area by mid to late morning through the afternoon. Thanks to the rain and a brisk easterly wind of 10 to 15mph, high temperatures today will be considerably cooler than yesterday with readings remaining in the 50s in most locations. && .LONG TERM...(Tonight through Monday) ISSUED AT 324 AM CDT TUE OCT 27 2015 Rain will continue tonight as the Louisiana low tracks northward across central Illinois. Forecast soundings remain quite stable, but do show modest elevated instability as the upper trough arrives. Think this may be just enough to produce a rumble or two of thunder, so will continue to mention isolated thunderstorms tonight. As the low lifts into the Great Lakes, showers will gradually diminish from southwest to northeast on Wednesday. Total rainfall with this system will generally be around 1 inch...with higher totals of 1 to 2 inches focused along/east of the I-57 corridor into the Ohio River Valley. Thanks to deepening surface low pressure over the Great Lakes and an approaching deep upper low, Thursday is shaping up to be the coolest day of the forecast period. Cloud cover associated with the upper system will likely remain just north of the CWA across northern Illinois. Despite abundant sunshine, brisk W/NW winds gusting to around 25mph will create a distinct chill as high temperatures struggle to reach the lower to middle 50s. After a very cool night Thursday night with lows dipping into the lower to middle 30s, temperatures will begin to rebound well into the 50s on Friday as high pressure drifts across the area. Models are still having trouble resolving the next potential system over the weekend. An upper low is expected to dive into the Desert Southwest on Friday, then slowly track E/NE through early next week. Exactly how quickly this process unfolds remains in question, as the models differ on how amplified the low will become. The 00z Oct 27 GEM is the deepest and furthest south with the low, keeping it over northwest Mexico until finally ejecting it northeastward into the Midwest by Tuesday. Meanwhile, the GFS and ECMWF are both more progressive...with the GFS tracking the low across the area on Sunday and the ECMWF on Monday. Given the considerable model spread, have opted to make few changes to the going forecast which follows the GFS closely. As a result, have introduced chance PoPs late Friday night into Saturday as a northern-stream wave approaches from the Northern Plains and have continued PoPs through Sunday night as the Desert Southwest low ejects northeastward. Have then gone with a dry forecast for Monday. Will need to watch future model trends closely...as further adjustments will likely be needed for the PoP forecast over the upcoming weekend. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1143 PM CDT MON OCT 26 2015 A developing low pressure system will lift into the Midwest Tuesday from the lower Mississippi Valley. The approach of this system, and associated rainfall, will have conditions across the central Illinois terminals rapidly decrease from VFR to IFR or lower late tonight into Tuesday morning. Once the rains and IFR conditions develop, they should linger through the 06Z TAF valid time and beyond. Easterly winds will prevail through the period to the north of the approaching low. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Barnes LONG TERM...Barnes AVIATION...BAK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
526 AM EDT TUE OCT 27 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 518 AM EDT TUE OCT 27 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL TROUGH DEVELOPING FROM SASK/ALBERTA INTO THE NRN ROCKIES AND WRN PLAINS WITH SEVERAL EMBEDDED SHORTWAVES. DOWNSTREAM...A RIDGE WAS BUILDING FROM THE UPPER MS VALLEY TO THE WRN GREAT LAKES. A THE SFC...SE FLOW PREVAILED THROUGH THE REGION BTWN HIGH PRES OVER NRN ONTARIO AND QUEBEC AND A TROUGH OVER THE WRN PLAINS. A BAND OF LIGHT SHOWERS OR SPRINKLES ASSOCIAED WITH WAA AND 295K ISENTROPIC LIFT NORTH OF A SFC FRONT THROUGH SRN MN. OTHERWISE...IR LOOP SHOWED MID CLOUDS SPREADING ACROSS UPPER MI WHERE AREAS OF LOW CLOUDS AND PATCHY FOG HAD ALSO DEVELOPED. TODAY...RADAR TRENDS AND SHORT RANGE MODELS SUGGEST THAT THE AREA OF LIGHT PCPN FROM N CNTRL MN INTO NW WI WILL CONTINUE TO LIFT TO THE NNE WITH ONLY A FEW SPRINKLES POSSIBLE OVER THE FAR WEST BEFORE 15Z. OTHERWISE...DRIER AIR FROM 925-850 MB MOVING IN FROM THE SOUTH COMBINED WITH LIMITED DAYTIME HEATING/MIXING SHOULD HELP SCOUR OUR THE LOWER CLOUDS THIS MORNING. HOWEVER...MID LEVEL CLOUDS WILL CONTINUE TO THICKEN. NEVERTHELESS...WAA WILL HELP PUSH HIGH TEMPS INTO THE LOWER TO MID 50S. TONIGHT...THE MODELS WERE IN GOOD AGREEMENT WITH THE CNTRL PLAINS SHORTWAVE LIFTING TOWARD IA AS A STRONGER SHRTWV OVER CNTRL SASK DROP INTO SRN MANITOBA. A DEEPENING SFC LOW WILL ALSO LIFT TO SRN WI. INCREASING SRLY 80-700 MB FLOW TO 40-50 KNOTS WILL DRAW ABUNDANT MOISTURE TOWARD UPPER MI (PWAT TO AROUND 1.0 INCH) WITH RAIN SPREADING ACROSS THE CWA LATE...MAINLY BTWN 09Z-12Z. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 512 AM EDT TUE OCT 27 2015 DEEPENING LONGWAVE TROUGH OVER THE CENTRAL CONUS ON WEDNESDAY RESULTS FROM PHASING OF MANY INDIVIDUAL SHORTWAVES STRETCHING FROM BRITISH COLUMBIA THROUGH THE INTERMOUNTAIN WEST. AS TROUGH DEEPENS SFC LOW 995-1000MB DEVELOPS OVER IA/IL/SOUTHERN WI BY 12Z ON WED. MOIST ADVECTION OF PWATS OVER 1 INCH AHEAD OF H85 TROUGH AND SFC LOW ALONG WITH H85-H5 Q-VECTOR CONVERGENCE FM THE DEEPENING TROUGH SHOULD SPREAD THE RAIN CURRENTLY OVER LOWER MISSISSIPPI RIVER VALLEY ACROSS THE UPPER GREAT LAKES BY DAYBREAK ON WEDNESDAY. ISENTROPIC ASCENT 290-300K/H9-H65 ALONG WITH THE LARGER SCALE FORCING WITH SOME ADDITIONAL ASSIST TO RIGHT ENTRANCE REGION OF UPPER JET OVER ONTARIO WILL RESULT IN MODERATE RAIN OVER UPR MICHIGAN ON WEDNESDAY. AS THE ISENTROPIC ASCENT FADES IN THE MID-LATE AFTN AND Q-VECTOR DIVERGENCE SPREADS NORTH OVER CWA IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE EXPECT RAIN TO START TO DIMINISH. MID CONUS TROUGH CLOSES OFF SHARPLY INTO THURSDAY AS INITIAL CENTRAL CONUS TROUGH MOVING EAST PHASES WITH STRONG NORTHERN STREAM TROUGH DIGGING SSE FM SASKATCHEWAN AND MANITOBA ON WEDNESDAY MORNING TO THE WESTERN GREAT LAKES WEDNESDAY NIGHT. SFC LOW LIFTING FM THE MIDDLE MISSISSIPPI RIVER VALLEY DEEPENS TO NEAR 983-985MB AS IT REACHES SOUTH CENTRAL LK SUPERIOR WEDNESDAY EVENING THEN STAYS SIMILAR STRENGTH AS IT MOVES TO FAR EAST LK SUPERIOR OR JUST EAST OF LK SUPERIOR BY 12Z THURSDAY. TREND IS SLOWER IN MAJORITY OF GUIDANCE IN LIFTING THE LOW NORTH OF THE REGION. MAIN RESULT IS MORE WIDESPREAD PRECIP LINGERING OVER MUCH OF UPR MICHIGAN WEDNESDAY NIGHT INTO THURSDAY WITH TROWAL WORKING ACROSS WEST TO EAST AS SEEN IN THETA-E FIELDS WITH HEIGHT /ESPECIALLY H7-H6/ AND H7-H5 Q-VECTOR CONVERGENCE. ALSO SEE THE SLOWER TREND SHOW UP WITH WARMER AIR IN THE SFC-H85 LAYER ORIENTED EAST TO WEST ACROSS UPR MICHIGAN AND LK SUPERIOR. BIGGEST IMPACT IS ON SNOW POTENTIAL OVER WESTERN CWA. H85 TEMPS LAST NIGHT WERE AROUND -2C AT THE WARMEST AND -5C AT THE COOLEST BUT LATEST RUNS HAVE TRENDED WARMER. GFS/NAM SOUNDINGS AT IWD INDICATE EVEN WITH H85 TEMPS AROUND -2C OR -3C/GOOD ENOUGH FOR LAKE ENHANCEMENT WITH WATER TEMPS AROUND 8C AND PLENTY OF LARGE SCALE LIFT/MOISTURE/...WET BULB ZERO HEIGHTS REMAIN AT OR ABOVE 1000 FT AGL WHICH SUGGEST A MIX OF RAIN AND SNOW...BUT NOT MUCH SNOW ACCUMULATION. WILL BE TIGHT GRADIENT BTWN WHERE SNOW IS MAIN PYPE AND WHERE THERE WILL BE MIX OR JUST RAIN. RIGHT NOW BELIEVE THAT LINE WILL STAY MAINLY WEST AND SOUTH OF WESTERN CWA. TRENDED SNOW BACK OVER WESTERN INTERIOR TO LESS THAN 0.5 INCH. COOL AND BREEZY CONDITIONS EXPECTED ON THURSDAY ALL CWA. STRONGEST WINDS WILL BE ALONG LK SUPERIOR. SOLID 40-45 MPH IN THE MIXED LAYER THOUGH SLOWER TREND WITH SFC LOW AND LACK OF STRONG COLD AIR ADVECTION WILL COMPLICATE HOW QUICKLY THE STRONG WINDS MIX TO SFC. GOOD PORTION OF THESE WINDS WILL MAKE IT TO SFC AS GUSTS. GALES LOOK CERTAIN OVER LK SUPERIOR AND PROBABLY WILL NEED WIND ADVISORY HEADLINES ON ADJACENT SHORELINES OF NORTHERN UPR MICHIGAN. MOST FAVORED LOCATIONS TO SEE STRONGEST WINDS WOULD BE COPPER HARBOR AND MUNISING/GRAND MARAIS/FAR NORTHERN LUCE COUNTY. WINDS DIMINISH BY MIDNIGHT THURSDAY NIGHT. COOLEST AIR SETTLES ACROSS LK SUPERIOR ON THURSDAY NIGHT WITH H85 TEMPS DOWN TO -6C OR -7C. SOUNDINGS AT END OF FETCH OVER EASTERN LK SUPERIOR INDICATE SHALLOW MOIST LAYER AROUND H85 AND DRY SUB CLOUD LAYER. KEPT LOW CHANCES IN FOR LAKE EFFECT WITH SUFFICIENT OVERWATER INSTABILITY...BUT DRY AIR BLO CLOUD BASE AND FLOW BECOMING MORE ANTICYLONIC SHOULD ALLOW FOR DIMINISHING TREND TO LAKE EFFECT INTO FRIDAY. EXPECT SKIES TO STAY MOSTLY CLOUDY WITH INCREASING WARM AIR ADVECTION OCCURRING ATOP SHALLOW COLD LAYER. MID CLOUDS INCREASE IN THE AFTN AHEAD OF NEXT CHANCE OF RAIN WHICH ARRIVES OVERNIGHT FRIDAY NIGHT. GFS IS NOW JOINED BY ECMWF IN SHOWING SWATH OF RAIN SPREADING OVER UPPER GREAT LAKES LATE FRIDAY NIGHT INTO AT LEAST SATURDAY MORNING AHEAD OF SHORTWAVE TROUGH CROSSING THE NORTHERN PLAINS. STRONGEST LOW-LEVEL MOISTURE ADVECTION REMAINS MORE OVER CNTRL AND LOWER GREAT LAKES...SO LIKELY WILL NOT SEE TOO HIGH AMOUNTS OVER UPR MICHIGAN /AROUND 0.10 INCH BUT LESS THAN 0.25 INCH/. HALLOWEEN 2014 HAD SNOW OVER PARTS OF UPR MICHIGAN SO AT LEAST WILL NOT BE LOOKING AT ANYTHING THAT COLD. TEMPS ON SATURDAY TOP OUT IN THE UPR 40S TO NEAR 50 DEGREES. WARMING TREND STILL EXPECTED INTO FIRST PART OF NEXT WEEK WITH ONLY SMALL CHANCES OF RAIN AS IT STANDS NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 416 AM EDT TUE OCT 27 2015 WITH A LIGHT UPSLOPE SSE FLOW DVLPG OFF LK MI AND ADVECTING RA MOISTENED AIR INTO SAW IN THE PRESENCE OF NOCTURNAL COOLING... EXPECT CONDITIONS THERE TO DETERIORATE TO IFR EARLY THIS MRNG. THIS FLOW WL TAP SOME DRIER AIR NEAR GRB LATER...SO CONDITIONS ARE LIKELY TO IMPROVE TOWARD SUNRISE. AS THE SSE WIND SLOWLY INCREASES...INCRSG DOWNSLOPE WRMG AT IWD SHOULD BREAK UP THE LO CLD CIG PRESENT THERE AND BRING A RETURN OF VFR WX. ALTHOUGH CMX IS DOMINATED BY LLVL DRY AIR ATTM WITH A LGT NE WIND...SOME LO CLDS/FOG MAY IMPACT THAT SITE FOR A TIME AS THE FLOW SHIFTS MORE TO THE ESE. AS THE S WIND AHEAD OF DVLPG LO PRES TO THE W TAPS THE DRIER LLVL AIR TODAY WITH DAYTIME HEATING...ANY LINGERNIG LO CLDS WL GIVE WAY TO VFR CONDITIONS AT ALL 3 TAF SITES DESPITE PLENTY OF HIER CLDS. MORE CLDS AND SOME -RA WL ARRIVE FM THE SW TNGT...BUT VFR CONDITIONS SHOULD PREVAIL THRU 06Z. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 525 AM EDT TUE OCT 27 2015 WINDS WILL BEGIN TO INCREASE TODAY INTO TONIGHT AHEAD OF A STRENGTHING LOW LIFTING TOWARD THE WRN LAKES. THE LOW WILL RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY LATE THIS AFTERNOON...INCREASING FURTHER TO 20-30KT TONIGHT. THE STRONGEST WINDS TONIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. WINDS WILL TEMPORARILY DIMINISH IN THE VNCTY OF THE LOW/FRONT AS THEY MOVE ACROSS LAKE SUPERIOR WED. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED THRU THU WITH THE STRONGEST WINDS TO AROUND 40KT OVER THE E HALF OF THE LAKE. WINDS WILL DIMINISH TO UNDER 20KT W TO E THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...KC MARINE...- NONE -
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
519 AM EDT TUE OCT 27 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 518 AM EDT TUE OCT 27 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL TROUGH DEVELOPING FROM SASK/ALBERTA INTO THE NRN ROCKIES AND WRN PLAINS WITH SEVERAL EMBEDDED SHORTWAVES. DOWNSTREAM...A RIDGE WAS BUILDING FROM THE UPPER MS VALLEY TO THE WRN GREAT LAKES. A THE SFC...SE FLOW PREVAILED THROUGH THE REGION BTWN HIGH PRES OVER NRN ONTARIO AND QUEBEC AND A TROUGH OVER THE WRN PLAINS. A BAND OF LIGHT SHOWERS OR SPRINKLES ASSOCIAED WITH WAA AND 295K ISENTROPIC LIFT NORTH OF A SFC FRONT THROUGH SRN MN. OTHERWISE...IR LOOP SHOWED MID CLOUDS SPREADING ACROSS UPPER MI WHERE AREAS OF LOW CLOUDS AND PATCHY FOG HAD ALSO DEVELOPED. TODAY...RADAR TRENDS AND SHORT RANGE MODELS SUGGEST THAT THE AREA OF LIGHT PCPN FROM N CNTRL MN INTO NW WI WILL CONTINUE TO LIFT TO THE NNE WITH ONLY A FEW SPRINKLES POSSIBLE OVER THE FAR WEST BEFORE 15Z. OTHERWISE...DRIER AIR FROM 925-850 MB MOVING IN FROM THE SOUTH COMBINED WITH LIMITED DAYTIME HEATING/MIXING SHOULD HELP SCOUR OUR THE LOWER CLOUDS THIS MORNING. HOWEVER...MID LEVEL CLOUDS WILL CONTINUE TO THICKEN. NEVERTHELESS...WAA WILL HELP PUSH HIGH TEMPS INTO THE LOWER TO MID 50S. TONIGHT...THE MODELS WERE IN GOOD AGREEMENT WITH THE CNTRL PLAINS SHORTWAVE LIFTING TOWARD IA AS A STRONGER SHRTWV OVER CNTRL SASK DROP INTO SRN MANITOBA. A DEEPENING SFC LOW WILL ALSO LIFT TO SRN WI. INCREASING SRLY 80-700 MB FLOW TO 40-50 KNOTS WILL DRAW ABUNDANT MOISTURE TOWARD UPPER MI (PWAT TO AROUND 1.0 INCH) WITH RAIN SPREADING ACROSS THE CWA LATE...MAINLY BTWN 09Z-12Z. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 512 AM EDT TUE OCT 27 2015 DEEPENING LONGWAVE TROUGH OVER THE CENTRAL CONUS ON WEDNESDAY RESULTS FROM PHASING OF MANY INDIVIDUAL SHORTWAVES STRETCHING FROM BRITISH COLUMBIA THROUGH THE INTERMOUNTAIN WEST. AS TROUGH DEEPENS SFC LOW 995-1000MB DEVELOPS OVER IA/IL/SOUTHERN WI BY 12Z ON WED. MOIST ADVECTION OF PWATS OVER 1 INCH AHEAD OF H85 TROUGH AND SFC LOW ALONG WITH H85-H5 Q-VECTOR CONVERGENCE FM THE DEEPENING TROUGH SHOULD SPREAD THE RAIN CURRENTLY OVER LOWER MISSISSIPPI RIVER VALLEY ACROSS THE UPPER GREAT LAKES BY DAYBREAK ON WEDNESDAY. ISENTROPIC ASCENT 290-300K/H9-H65 ALONG WITH THE LARGER SCALE FORCING WITH SOME ADDITIONAL ASSIST TO RIGHT ENTRANCE REGION OF UPPER JET OVER ONTARIO WILL RESULT IN MODERATE RAIN OVER UPR MICHIGAN ON WEDNESDAY. AS THE ISENTROPIC ASCENT FADES IN THE MID-LATE AFTN AND Q-VECTOR DIVERGENCE SPREADS NORTH OVER CWA IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE EXPECT RAIN TO START TO DIMINISH. MID CONUS TROUGH CLOSES OFF SHARPLY INTO THURSDAY AS INITIAL CENTRAL CONUS TROUGH MOVING EAST PHASES WITH STRONG NORTHERN STREAM TROUGH DIGGING SSE FM SASKATCHEWAN AND MANITOBA ON WEDNESDAY MORNING TO THE WESTERN GREAT LAKES WEDNESDAY NIGHT. SFC LOW LIFTING FM THE MIDDLE MISSISSIPPI RIVER VALLEY DEEPENS TO NEAR 983-985MB AS IT REACHES SOUTH CENTRAL LK SUPERIOR WEDNESDAY EVENING THEN STAYS SIMILAR STRENGTH AS IT MOVES TO FAR EAST LK SUPERIOR OR JUST EAST OF LK SUPERIOR BY 12Z THURSDAY. TREND IS SLOWER IN MAJORITY OF GUIDANCE IN LIFTING THE LOW NORTH OF THE REGION. MAIN RESULT IS MORE WIDESPREAD PRECIP LINGERING OVER MUCH OF UPR MICHIGAN WEDNESDAY NIGHT INTO THURSDAY WITH TROWAL WORKING ACROSS WEST TO EAST AS SEEN IN THETA-E FIELDS WITH HEIGHT /ESPECIALLY H7-H6/ AND H7-H5 Q-VECTOR CONVERGENCE. ALSO SEE THE SLOWER TREND SHOW UP WITH WARMER AIR IN THE SFC-H85 LAYER ORIENTED EAST TO WEST ACROSS UPR MICHIGAN AND LK SUPERIOR. BIGGEST IMPACT IS ON SNOW POTENTIAL OVER WESTERN CWA. H85 TEMPS LAST NIGHT WERE AROUND -2C AT THE WARMEST AND -5C AT THE COOLEST BUT LATEST RUNS HAVE TRENDED WARMER. GFS/NAM SOUNDINGS AT IWD INDICATE EVEN WITH H85 TEMPS AROUND -2C OR -3C/GOOD ENOUGH FOR LAKE ENHANCEMENT WITH WATER TEMPS AROUND 8C AND PLENTY OF LARGE SCALE LIFT/MOISTURE/...WET BULB ZERO HEIGHTS REMAIN AT OR ABOVE 1000 FT AGL WHICH SUGGEST A MIX OF RAIN AND SNOW...BUT NOT MUCH SNOW ACCUMULATION. WILL BE TIGHT GRADIENT BTWN WHERE SNOW IS MAIN PYPE AND WHERE THERE WILL BE MIX OR JUST RAIN. RIGHT NOW BELIEVE THAT LINE WILL STAY MAINLY WEST AND SOUTH OF WESTERN CWA. TRENDED SNOW BACK OVER WESTERN INTERIOR TO LESS THAN 0.5 INCH. COOL AND BREEZY CONDITIONS EXPECTED ON THURSDAY ALL CWA. STRONGEST WINDS WILL BE ALONG LK SUPERIOR. SOLID 40-45 MPH IN THE MIXED LAYER THOUGH SLOWER TREND WITH SFC LOW AND LACK OF STRONG COLD AIR ADVECTION WILL COMPLICATE HOW QUICKLY THE STRONG WINDS MIX TO SFC. GOOD PORTION OF THESE WINDS WILL MAKE IT TO SFC AS GUSTS. GALES LOOK CERTAIN OVER LK SUPERIOR AND PROBABLY WILL NEED WIND ADVISORY HEADLINES ON ADJACENT SHORELINES OF NORTHERN UPR MICHIGAN. MOST FAVORED LOCATIONS TO SEE STRONGEST WINDS WOULD BE COPPER HARBOR AND MUNISING/GRAND MARAIS/FAR NORTHERN LUCE COUNTY. WINDS DIMINISH BY MIDNIGHT THURSDAY NIGHT. COOLEST AIR SETTLES ACROSS LK SUPERIOR ON THURSDAY NIGHT WITH H85 TEMPS DOWN TO -6C OR -7C. SOUNDINGS AT END OF FETCH OVER EASTERN LK SUPERIOR INDICATE SHALLOW MOIST LAYER AROUND H85 AND DRY SUB CLOUD LAYER. KEPT LOW CHANCES IN FOR LAKE EFFECT WITH SUFFICIENT OVERWATER INSTABILITY...BUT DRY AIR BLO CLOUD BASE AND FLOW BECOMING MORE ANTICYLONIC SHOULD ALLOW FOR DIMINISHING TREND TO LAKE EFFECT INTO FRIDAY. EXPECT SKIES TO STAY MOSTLY CLOUDY WITH INCREASING WARM AIR ADVECTION OCCURRING ATOP SHALLOW COLD LAYER. MID CLOUDS INCREASE IN THE AFTN AHEAD OF NEXT CHANCE OF RAIN WHICH ARRIVES OVERNIGHT FRIDAY NIGHT. GFS IS NOW JOINED BY ECMWF IN SHOWING SWATH OF RAIN SPREADING OVER UPPER GREAT LAKES LATE FRIDAY NIGHT INTO AT LEAST SATURDAY MORNING AHEAD OF SHORTWAVE TROUGH CROSSING THE NORTHERN PLAINS. STRONGEST LOW-LEVEL MOISTURE ADVECTION REMAINS MORE OVER CNTRL AND LOWER GREAT LAKES...SO LIKELY WILL NOT SEE TOO HIGH AMOUNTS OVER UPR MICHIGAN /AROUND 0.10 INCH BUT LESS THAN 0.25 INCH/. HALLOWEEN 2014 HAD SNOW OVER PARTS OF UPR MICHIGAN SO AT LEAST WILL NOT BE LOOKING AT ANYTHING THAT COLD. TEMPS ON SATURDAY TOP OUT IN THE UPR 40S TO NEAR 50 DEGREES. WARMING TREND STILL EXPECTED INTO FIRST PART OF NEXT WEEK WITH ONLY SMALL CHANCES OF RAIN AS IT STANDS NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 416 AM EDT TUE OCT 27 2015 WITH A LIGHT UPSLOPE SSE FLOW DVLPG OFF LK MI AND ADVECTING RA MOISTENED AIR INTO SAW IN THE PRESENCE OF NOCTURNAL COOLING... EXPECT CONDITIONS THERE TO DETERIORATE TO IFR EARLY THIS MRNG. THIS FLOW WL TAP SOME DRIER AIR NEAR GRB LATER...SO CONDITIONS ARE LIKELY TO IMPROVE TOWARD SUNRISE. AS THE SSE WIND SLOWLY INCREASES...INCRSG DOWNSLOPE WRMG AT IWD SHOULD BREAK UP THE LO CLD CIG PRESENT THERE AND BRING A RETURN OF VFR WX. ALTHOUGH CMX IS DOMINATED BY LLVL DRY AIR ATTM WITH A LGT NE WIND...SOME LO CLDS/FOG MAY IMPACT THAT SITE FOR A TIME AS THE FLOW SHIFTS MORE TO THE ESE. AS THE S WIND AHEAD OF DVLPG LO PRES TO THE W TAPS THE DRIER LLVL AIR TODAY WITH DAYTIME HEATING...ANY LINGERNIG LO CLDS WL GIVE WAY TO VFR CONDITIONS AT ALL 3 TAF SITES DESPITE PLENTY OF HIER CLDS. MORE CLDS AND SOME -RA WL ARRIVE FM THE SW TNGT...BUT VFR CONDITIONS SHOULD PREVAIL THRU 06Z. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EDT MON OCT 26 2015 LIGHT WINDS MOSTLY UNDER 15KT WILL START THE FCST PERIOD TONIGHT ACROSS MOST OF LAKE SUPERIOR. WINDS OVER WRN LAKE SUPERIOR WILL GUST UP TOWARD 20KT. WINDS WILL BEGIN TO RAMP UP ON TUE AHEAD OF A COLD FRONT SWEEPING ACROSS THE PLAINS. AS THE COLD FRONT REACHES THE UPPER LAKES WED...LOW PRES WILL ORGANIZE ALONG THE FRONT. THE LOW WILL THEN RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY LATE TUE AFTN... INCREASING FURTHER TO 20-30KT TUE NIGHT. THE STRONGEST WINDS TUE NIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. NOT OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE GUSTS TUE NIGHT OVER CNTRL/ERN LAKE SUPERIOR...ESPECIALLY IN THE CARIBOU ISLAND/WHITEFISH POINT AREA. WINDS WILL TEMPORARILY DIMINISH IN THE VNCTY OF THE LOW/FRONT AS THEY MOVE ACROSS LAKE SUPERIOR WED. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED THRU THU WITH THE STRONGEST WINDS TO AROUND 40KT OVER THE E HALF OF THE LAKE. WINDS WILL DIMINISH TO UNDER 20KT W TO E THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
512 AM EDT TUE OCT 27 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 419 PM EDT MON OCT 26 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE UPPER GREAT LAKES ON THE SRN PERIPHERY OF AN ERN CANADA TROF ANCHORED BY A DEEP MID LEVEL LOW CENTERED JUST N OF HUDSON BAY. WITHIN THE TROF...110KT UPPER JET EXTENDS FROM NE MN TO NEW ENGLAND. RIGHT ENTRANCE UPPER DIVERGENCE ASSOCIATED WITH THE JET...CORRESPONDING FGEN IN THE LOWER TO MID LEVELS...AND SHORTWAVE HAVE SUPPORTED SHRA FROM NW WI E ACROSS UPPER MI TODAY...THOUGH SHRA HAVE BEEN CONFINED TO ROUGHLY THE SRN HALF OF THE U.P. OTHERWISE...IT`S BEEN A CLOUDY DAY. HOWEVER...RECENTLY MID CLOUDS HAVE CLEARED OUT OVER THE KEWEENAW WITH DAYTIME HEATING NOW LEADING TO SOME DIURNAL CU/STRATOCU DEVELOPMENT THERE. TEMPS ARE IN THE 40S ACROSS THE FCST AREA...BUT ARE NEARING 50F ON THE KEWEENAW AND HAVE RISEN INTO THE LOW/MID 50S IN MENOMINEE COUNTY. WITH FORCING THAT HAS GENERATED THE SHRA TODAY BREAKING DOWN THIS EVENING...EXPECT A DIMINISHING TREND TO THE SHRA AS MODELS INDICATE. HOWEVER...ONGOING WAA AHEAD OF TROF SWINGING ACROSS THE ROCKIES MAY WORK TO GENERATE ISOLD -SHRA/SPRINKLES ALONG THE CURRENT PCPN GENERATION ZONE THAT IS SLOWLY LIFTING NE AS SEEN ON RADAR IMAGERY LOOPS ACROSS NW WI TO AROUND KDLH. TO ACCOUNT FOR THIS POSSIBILITY...LINGERED SOME SCHC POPS W INTO PORTIONS OF WRN UPPER THRU THE EVENING. TROF MOVING ACROSS THE ROCKIES TONIGHT SHIFTS OUT OVER THE PLAINS TUE. AHEAD OF THE TROF...MODELS SHOW BETTER FOCUS OF WAA SHIFTING TO THE NW OF UPPER MI. END RESULT WILL BE A DRY DAY...BUT WITH CONSIDERABLE MID AND HIGH CLOUDS OVERSPREADING THE AREA. DESPITE CLOUD COVER...TEMPS WILL TOP OUT A LITTLE ABOVE NORMAL IN THE LOW/MID 50S. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 512 AM EDT TUE OCT 27 2015 DEEPENING LONGWAVE TROUGH OVER THE CENTRAL CONUS ON WEDNESDAY RESULTS FROM PHASING OF MANY INDIVIDUAL SHORTWAVES STRETCHING FROM BRITISH COLUMBIA THROUGH THE INTERMOUNTAIN WEST. AS TROUGH DEEPENS SFC LOW 995-1000MB DEVELOPS OVER IA/IL/SOUTHERN WI BY 12Z ON WED. MOIST ADVECTION OF PWATS OVER 1 INCH AHEAD OF H85 TROUGH AND SFC LOW ALONG WITH H85-H5 Q-VECTOR CONVERGENCE FM THE DEEPENING TROUGH SHOULD SPREAD THE RAIN CURRENTLY OVER LOWER MISSISSIPPI RIVER VALLEY ACROSS THE UPPER GREAT LAKES BY DAYBREAK ON WEDNESDAY. ISENTROPIC ASCENT 290-300K/H9-H65 ALONG WITH THE LARGER SCALE FORCING WITH SOME ADDITIONAL ASSIST TO RIGHT ENTRANCE REGION OF UPPER JET OVER ONTARIO WILL RESULT IN MODERATE RAIN OVER UPR MICHIGAN ON WEDNESDAY. AS THE ISENTROPIC ASCENT FADES IN THE MID-LATE AFTN AND Q-VECTOR DIVERGENCE SPREADS NORTH OVER CWA IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE EXPECT RAIN TO START TO DIMINISH. MID CONUS TROUGH CLOSES OFF SHARPLY INTO THURSDAY AS INITIAL CENTRAL CONUS TROUGH MOVING EAST PHASES WITH STRONG NORTHERN STREAM TROUGH DIGGING SSE FM SASKATCHEWAN AND MANITOBA ON WEDNESDAY MORNING TO THE WESTERN GREAT LAKES WEDNESDAY NIGHT. SFC LOW LIFTING FM THE MIDDLE MISSISSIPPI RIVER VALLEY DEEPENS TO NEAR 983-985MB AS IT REACHES SOUTH CENTRAL LK SUPERIOR WEDNESDAY EVENING THEN STAYS SIMILAR STRENGTH AS IT MOVES TO FAR EAST LK SUPERIOR OR JUST EAST OF LK SUPERIOR BY 12Z THURSDAY. TREND IS SLOWER IN MAJORITY OF GUIDANCE IN LIFTING THE LOW NORTH OF THE REGION. MAIN RESULT IS MORE WIDESPREAD PRECIP LINGERING OVER MUCH OF UPR MICHIGAN WEDNESDAY NIGHT INTO THURSDAY WITH TROWAL WORKING ACROSS WEST TO EAST AS SEEN IN THETA-E FIELDS WITH HEIGHT /ESPECIALLY H7-H6/ AND H7-H5 Q-VECTOR CONVERGENCE. ALSO SEE THE SLOWER TREND SHOW UP WITH WARMER AIR IN THE SFC-H85 LAYER ORIENTED EAST TO WEST ACROSS UPR MICHIGAN AND LK SUPERIOR. BIGGEST IMPACT IS ON SNOW POTENTIAL OVER WESTERN CWA. H85 TEMPS LAST NIGHT WERE AROUND -2C AT THE WARMEST AND -5C AT THE COOLEST BUT LATEST RUNS HAVE TRENDED WARMER. GFS/NAM SOUNDINGS AT IWD INDICATE EVEN WITH H85 TEMPS AROUND -2C OR -3C/GOOD ENOUGH FOR LAKE ENHANCEMENT WITH WATER TEMPS AROUND 8C AND PLENTY OF LARGE SCALE LIFT/MOISTURE/...WET BULB ZERO HEIGHTS REMAIN AT OR ABOVE 1000 FT AGL WHICH SUGGEST A MIX OF RAIN AND SNOW...BUT NOT MUCH SNOW ACCUMULATION. WILL BE TIGHT GRADIENT BTWN WHERE SNOW IS MAIN PYPE AND WHERE THERE WILL BE MIX OR JUST RAIN. RIGHT NOW BELIEVE THAT LINE WILL STAY MAINLY WEST AND SOUTH OF WESTERN CWA. TRENDED SNOW BACK OVER WESTERN INTERIOR TO LESS THAN 0.5 INCH. COOL AND BREEZY CONDITIONS EXPECTED ON THURSDAY ALL CWA. STRONGEST WINDS WILL BE ALONG LK SUPERIOR. SOLID 40-45 MPH IN THE MIXED LAYER THOUGH SLOWER TREND WITH SFC LOW AND LACK OF STRONG COLD AIR ADVECTION WILL COMPLICATE HOW QUICKLY THE STRONG WINDS MIX TO SFC. GOOD PORTION OF THESE WINDS WILL MAKE IT TO SFC AS GUSTS. GALES LOOK CERTAIN OVER LK SUPERIOR AND PROBABLY WILL NEED WIND ADVISORY HEADLINES ON ADJACENT SHORELINES OF NORTHERN UPR MICHIGAN. MOST FAVORED LOCATIONS TO SEE STRONGEST WINDS WOULD BE COPPER HARBOR AND MUNISING/GRAND MARAIS/FAR NORTHERN LUCE COUNTY. WINDS DIMINISH BY MIDNIGHT THURSDAY NIGHT. COOLEST AIR SETTLES ACROSS LK SUPERIOR ON THURSDAY NIGHT WITH H85 TEMPS DOWN TO -6C OR -7C. SOUNDINGS AT END OF FETCH OVER EASTERN LK SUPERIOR INDICATE SHALLOW MOIST LAYER AROUND H85 AND DRY SUB CLOUD LAYER. KEPT LOW CHANCES IN FOR LAKE EFFECT WITH SUFFICIENT OVERWATER INSTABILITY...BUT DRY AIR BLO CLOUD BASE AND FLOW BECOMING MORE ANTICYLONIC SHOULD ALLOW FOR DIMINISHING TREND TO LAKE EFFECT INTO FRIDAY. EXPECT SKIES TO STAY MOSTLY CLOUDY WITH INCREASING WARM AIR ADVECTION OCCURRING ATOP SHALLOW COLD LAYER. MID CLOUDS INCREASE IN THE AFTN AHEAD OF NEXT CHANCE OF RAIN WHICH ARRIVES OVERNIGHT FRIDAY NIGHT. GFS IS NOW JOINED BY ECMWF IN SHOWING SWATH OF RAIN SPREADING OVER UPPER GREAT LAKES LATE FRIDAY NIGHT INTO AT LEAST SATURDAY MORNING AHEAD OF SHORTWAVE TROUGH CROSSING THE NORTHERN PLAINS. STRONGEST LOW-LEVEL MOISTURE ADVECTION REMAINS MORE OVER CNTRL AND LOWER GREAT LAKES...SO LIKELY WILL NOT SEE TOO HIGH AMOUNTS OVER UPR MICHIGAN /AROUND 0.10 INCH BUT LESS THAN 0.25 INCH/. HALLOWEEN 2014 HAD SNOW OVER PARTS OF UPR MICHIGAN SO AT LEAST WILL NOT BE LOOKING AT ANYTHING THAT COLD. TEMPS ON SATURDAY TOP OUT IN THE UPR 40S TO NEAR 50 DEGREES. WARMING TREND STILL EXPECTED INTO FIRST PART OF NEXT WEEK WITH ONLY SMALL CHANCES OF RAIN AS IT STANDS NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 416 AM EDT TUE OCT 27 2015 WITH A LIGHT UPSLOPE SSE FLOW DVLPG OFF LK MI AND ADVECTING RA MOISTENED AIR INTO SAW IN THE PRESENCE OF NOCTURNAL COOLING... EXPECT CONDITIONS THERE TO DETERIORATE TO IFR EARLY THIS MRNG. THIS FLOW WL TAP SOME DRIER AIR NEAR GRB LATER...SO CONDITIONS ARE LIKELY TO IMPROVE TOWARD SUNRISE. AS THE SSE WIND SLOWLY INCREASES...INCRSG DOWNSLOPE WRMG AT IWD SHOULD BREAK UP THE LO CLD CIG PRESENT THERE AND BRING A RETURN OF VFR WX. ALTHOUGH CMX IS DOMINATED BY LLVL DRY AIR ATTM WITH A LGT NE WIND...SOME LO CLDS/FOG MAY IMPACT THAT SITE FOR A TIME AS THE FLOW SHIFTS MORE TO THE ESE. AS THE S WIND AHEAD OF DVLPG LO PRES TO THE W TAPS THE DRIER LLVL AIR TODAY WITH DAYTIME HEATING...ANY LINGERNIG LO CLDS WL GIVE WAY TO VFR CONDITIONS AT ALL 3 TAF SITES DESPITE PLENTY OF HIER CLDS. MORE CLDS AND SOME -RA WL ARRIVE FM THE SW TNGT...BUT VFR CONDITIONS SHOULD PREVAIL THRU 06Z. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EDT MON OCT 26 2015 LIGHT WINDS MOSTLY UNDER 15KT WILL START THE FCST PERIOD TONIGHT ACROSS MOST OF LAKE SUPERIOR. WINDS OVER WRN LAKE SUPERIOR WILL GUST UP TOWARD 20KT. WINDS WILL BEGIN TO RAMP UP ON TUE AHEAD OF A COLD FRONT SWEEPING ACROSS THE PLAINS. AS THE COLD FRONT REACHES THE UPPER LAKES WED...LOW PRES WILL ORGANIZE ALONG THE FRONT. THE LOW WILL THEN RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY LATE TUE AFTN... INCREASING FURTHER TO 20-30KT TUE NIGHT. THE STRONGEST WINDS TUE NIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. NOT OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE GUSTS TUE NIGHT OVER CNTRL/ERN LAKE SUPERIOR...ESPECIALLY IN THE CARIBOU ISLAND/WHITEFISH POINT AREA. WINDS WILL TEMPORARILY DIMINISH IN THE VNCTY OF THE LOW/FRONT AS THEY MOVE ACROSS LAKE SUPERIOR WED. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED THRU THU WITH THE STRONGEST WINDS TO AROUND 40KT OVER THE E HALF OF THE LAKE. WINDS WILL DIMINISH TO UNDER 20KT W TO E THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 AM EDT TUE OCT 27 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 419 PM EDT MON OCT 26 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE UPPER GREAT LAKES ON THE SRN PERIPHERY OF AN ERN CANADA TROF ANCHORED BY A DEEP MID LEVEL LOW CENTERED JUST N OF HUDSON BAY. WITHIN THE TROF...110KT UPPER JET EXTENDS FROM NE MN TO NEW ENGLAND. RIGHT ENTRANCE UPPER DIVERGENCE ASSOCIATED WITH THE JET...CORRESPONDING FGEN IN THE LOWER TO MID LEVELS...AND SHORTWAVE HAVE SUPPORTED SHRA FROM NW WI E ACROSS UPPER MI TODAY...THOUGH SHRA HAVE BEEN CONFINED TO ROUGHLY THE SRN HALF OF THE U.P. OTHERWISE...IT`S BEEN A CLOUDY DAY. HOWEVER...RECENTLY MID CLOUDS HAVE CLEARED OUT OVER THE KEWEENAW WITH DAYTIME HEATING NOW LEADING TO SOME DIURNAL CU/STRATOCU DEVELOPMENT THERE. TEMPS ARE IN THE 40S ACROSS THE FCST AREA...BUT ARE NEARING 50F ON THE KEWEENAW AND HAVE RISEN INTO THE LOW/MID 50S IN MENOMINEE COUNTY. WITH FORCING THAT HAS GENERATED THE SHRA TODAY BREAKING DOWN THIS EVENING...EXPECT A DIMINISHING TREND TO THE SHRA AS MODELS INDICATE. HOWEVER...ONGOING WAA AHEAD OF TROF SWINGING ACROSS THE ROCKIES MAY WORK TO GENERATE ISOLD -SHRA/SPRINKLES ALONG THE CURRENT PCPN GENERATION ZONE THAT IS SLOWLY LIFTING NE AS SEEN ON RADAR IMAGERY LOOPS ACROSS NW WI TO AROUND KDLH. TO ACCOUNT FOR THIS POSSIBILITY...LINGERED SOME SCHC POPS W INTO PORTIONS OF WRN UPPER THRU THE EVENING. TROF MOVING ACROSS THE ROCKIES TONIGHT SHIFTS OUT OVER THE PLAINS TUE. AHEAD OF THE TROF...MODELS SHOW BETTER FOCUS OF WAA SHIFTING TO THE NW OF UPPER MI. END RESULT WILL BE A DRY DAY...BUT WITH CONSIDERABLE MID AND HIGH CLOUDS OVERSPREADING THE AREA. DESPITE CLOUD COVER...TEMPS WILL TOP OUT A LITTLE ABOVE NORMAL IN THE LOW/MID 50S. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 423 PM EDT MON OCT 26 2015 MUCH OF THIS PERIOD WILL BE DOMINATED BY STEADY RAIN WEDNESDAY THEN COOLER/BREEZY CONDITIONS WITH LAKE EFFECT RAIN AND SNOW SHOWERS THURSDAY INTO FRIDAY. AT 00Z WEDNESDAY UPPER MI WILL BE IN BETWEEN A STRONG SFC HIGH PUSHING OFF THE NEW ENGLAND COAST...AND AN ELONGATED AREA OF LOW PRESSURE STRETCHING FROM THE N SASKATCHEWAN AND MANITOBA BORDER TO NE...AND THE LOWER MS VALLEY /REMNANTS OF HURRICANE PATRICA/. WILL BE STARTING OUT WITH A STRONG S-SE PUSH OF AIR ON 850MB WINDS OF 25- 40KTS OVERHEAD. THESE 850MB WINDS WILL INCREASE TO AN AVERAGE 40KTS CWA WIDE OVERNIGHT. THE CONSOLIDATING AREA OF LOW PRESSURE WILL CONVERGE AND STRETCH FROM MANITOBA TO IL/IN BY DAYBREAK WEDNESDAY...WITH STEADY RAIN THROUGH MID AFTERNOON. PRECIP TOTALS EARLY WEDNESDAY MORNING THROUGH THE REST OF THE DAY WILL LIKELY TOTAL AROUND OR OVER 0.5IN. THE SFC LOW WILL THEN DEEPEN TO NEAR 990MB EARLY WEDNESDAY AFTERNOON ACROSS UPPER MI/N LAKE MI...AND AROUND 980MB ACROSS N OR NE LAKE SUPERIOR BY 00Z THURSDAY. SO AFTER A BRIEF LULL IN THE WINDS MIDDAY WEDNESDAY AS THE LOW PRESSES...EXPECT STRONGER W-NW WINDS TO PUSH IN WEDNESDAY NIGHT. RAIN WILL BEGIN TO MIX WITH AND CHANGE OVER TO SNOW MAINLY INLAND FROM THE GREAT LAKES AS 850MB TEMPS FALL FROM AROUND 3C WEDNESDAY AFTERNOON TO 0 TO -5C BY 12Z THURSDAY. THE CONSENSUS...WITH THE COLD AIR IS TO HAVE IT PUSH MAINLY INLAND OR S OF THE CWA. THIS RESULTS IN ONLY MODERATE CONFIDENCE IN THE TIMING OR AMOUNTS OF SNOW POSSIBLE BEHIND THE LOW...AS THERE IS SOME DISCREPANCY ON THE HANDLING OF THE 500MB LOW AS IT SINKS IN BEHIND THE SFC LOW. STILL...IT WILL BE A COOL AND BREEZY DAY WITH GALES LIKELY CENTRAL AND E OVER LAKE SUPERIOR. THE GFS AND CANADIAN SOLUTIONS ARE THE FARTHEST S WITH THE LOW...ACROSS CENTRAL LAKE MI AND S WI AT 06Z THURSDAY. BY CONTRAST...THE NAM/ECMWF/SREF SOLUTIONS HAVE THE LOW OVER UPPER MI. WILL BE INTERESTING HOW THIS FALLS OVER THE NEXT COUPLE OF DAYS. WILL CONTINUE WITH A BLENDED SOLUTION FOR NOW. CONFIDENCE INCREASES AT THE TAIL END OF THE MOISTURE AS IT DEPARTS THURSDAY AFTERNOON. NW WINDS AND COOLER AIR WITH 850MB TEMPS AVERAGING -4 TO -5C WOULD RESULT IN MAINLY SNOW IF SFC TEMPS WERE JUST A COUPLE OF DEGREES COOLER. OTHERWISE...LOOK FOR SLOWLY RISING TEMPS FOR HIGHS THROUGH MONDAY. THIS WILL BE AS THE SFC RIDGE BUILDS INTO MUCH OF THE E HALF OF THE NATION FRIDAY. THIS AREA OF HIGH PRESSURE WILL EXIT TO OUR E FRIDAY NIGHT...AS WE RESIDE IN BETWEEN THE DEPARTING HIGH AND NEARING AREA OF LOW PRESSURE ACROSS W AND CENTRAL CANADA. WILL BE HARD TO COMPLETELY RULE OUT PRECIP FRIDAY NIGHT THROUGH MONDAY /WITH THE BEST CHANCE MONDAY WITH LOW PRESSURE NEARBY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 416 AM EDT TUE OCT 27 2015 WITH A LIGHT UPSLOPE SSE FLOW DVLPG OFF LK MI AND ADVECTING RA MOISTENED AIR INTO SAW IN THE PRESENCE OF NOCTURNAL COOLING... EXPECT CONDITIONS THERE TO DETERIORATE TO IFR EARLY THIS MRNG. THIS FLOW WL TAP SOME DRIER AIR NEAR GRB LATER...SO CONDITIONS ARE LIKELY TO IMPROVE TOWARD SUNRISE. AS THE SSE WIND SLOWLY INCREASES...INCRSG DOWNSLOPE WRMG AT IWD SHOULD BREAK UP THE LO CLD CIG PRESENT THERE AND BRING A RETURN OF VFR WX. ALTHOUGH CMX IS DOMINATED BY LLVL DRY AIR ATTM WITH A LGT NE WIND...SOME LO CLDS/FOG MAY IMPACT THAT SITE FOR A TIME AS THE FLOW SHIFTS MORE TO THE ESE. AS THE S WIND AHEAD OF DVLPG LO PRES TO THE W TAPS THE DRIER LLVL AIR TODAY WITH DAYTIME HEATING...ANY LINGERNIG LO CLDS WL GIVE WAY TO VFR CONDITIONS AT ALL 3 TAF SITES DESPITE PLENTY OF HIER CLDS. MORE CLDS AND SOME -RA WL ARRIVE FM THE SW TNGT...BUT VFR CONDITIONS SHOULD PREVAIL THRU 06Z. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EDT MON OCT 26 2015 LIGHT WINDS MOSTLY UNDER 15KT WILL START THE FCST PERIOD TONIGHT ACROSS MOST OF LAKE SUPERIOR. WINDS OVER WRN LAKE SUPERIOR WILL GUST UP TOWARD 20KT. WINDS WILL BEGIN TO RAMP UP ON TUE AHEAD OF A COLD FRONT SWEEPING ACROSS THE PLAINS. AS THE COLD FRONT REACHES THE UPPER LAKES WED...LOW PRES WILL ORGANIZE ALONG THE FRONT. THE LOW WILL THEN RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY LATE TUE AFTN... INCREASING FURTHER TO 20-30KT TUE NIGHT. THE STRONGEST WINDS TUE NIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. NOT OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE GUSTS TUE NIGHT OVER CNTRL/ERN LAKE SUPERIOR...ESPECIALLY IN THE CARIBOU ISLAND/WHITEFISH POINT AREA. WINDS WILL TEMPORARILY DIMINISH IN THE VNCTY OF THE LOW/FRONT AS THEY MOVE ACROSS LAKE SUPERIOR WED. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED THRU THU WITH THE STRONGEST WINDS TO AROUND 40KT OVER THE E HALF OF THE LAKE. WINDS WILL DIMINISH TO UNDER 20KT W TO E THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
132 AM EDT TUE OCT 27 2015 .SYNOPSIS... UPPER LEVEL SYSTEM WITH REMNANTS OF PATRICIA BRINGS RAIN LATE TONIGHT AND TUESDAY INTO WEDNESDAY. COLD FRONT CROSSES LATE WEDNESDAY. HIGH PRESSURE CROSSES FRIDAY THROUGH SATURDAY. && .NEAR TERM /THROUGH TODAY/... 130AM UPDATE... RADAR ECHOES BECOMING MORE NUMEROUS...BUT PRECIPITATION ASSOCIATED WITH THE ECHOES IS STILL FALLING OUT OF 9KFT DECKS...SO STILL LIKELY ONLY SEEING VARY LIGHT RAIN OR SPRINKLES. PREVIOUS DISCUSSION... NO REAL SIGNIFICANT CHANGES NEEDED TO PREVIOUS FORECAST. TWEAKED POPS SOME TODAY TO REFLECT CURRENT TRENDS USING HRRR AND WRFARW. FOR TONIGHT INTO TUESDAY TRIED TO ENHANCE THE DOWNSLOPE PRECIP SHADOW SOME IN THE I79 CORRIDOR...GOING WITH POP/QPF MINIMUM THERE. ON THE OTHER HAND...INCREASED POPS ACROSS THE EASTERN SLOPES AND FAR WESTERN CWA TO AT OR NEAR 100 PERCENT BY TOMORROW AFTERNOON AS A DEFORMATION BAND SLIDES NORTH ACROSS THE CWA. THIS IS ASSOCIATED WITH THE SURFACE LOW CURRENTLY COMING ASHORE FROM THE GULF OF MEXICO. THIS LOW WILL GRADUALLY DRIFT NORTHWARD UP THE MISSISSIPPI RIVER VALLEY THROUGH THE PERIOD AS IT STARTS TO FEEL THE INFLUENCE OF A STRONG UPPER LEVEL LOW ENTERING CENTRAL CANADA. WINDS WILL PICK UP TOMORROW AS 850MB FLOW INCREASES OUT OF THE E/SE TUESDAY. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... STOUT BAROCLINIC LEAF READILY EVIDENT ON STLT TODAY OVER SE 1/4 OF THE CONUS. ASSOCIATED WITH UPPER LEVEL LOW OVER THE LOWER MISSISSIPPI VALLEY...THE CONFLUENCE ZONE WHERE THE NRN AND SRN STREAM JETS MEET OVER THE MID ATLANTIC REGION SERVED TO ENHANCE THE EFFECT. THE UPPER LEVEL LOW OPENS UP AS IT LIFTS NEWD TONIGHT...AND BECOMES A RATHER FLAT WAVE BY THE TIME IT CROSSES THE CWA TUE NT...IN SW UPPER LEVEL FLOW AHEAD OF A LARGER UPPER LEVEL TROUGH FAST APPROACHING FROM THE W EVEN AS IT FORMS OUT OF SEVERAL SMALLER S/W TROUGHS. THE ORIGINAL SFC FEATURE BECOMES WASHED OUT BY THE TIME IT REACHES THE CWA TUE NT...BUT A TIGHT W TO E LOW LEVEL GRADIENT SPELLS A CLASSIC RAIN SHADOW EFFECT ON STRONG SE FLOW. WITH THIS...AND MOST OF THE FORCING OUTSIDE UPSLOPE GENERATED IN THE UPPER LEVELS...RAINFALL TUE NT INTO WED SHOULD BE MANAGEABLE...A SLOW SOAKER WITH UP TO A HALF AN INCH OVER SIX HOUR PERIOD IN THE ERN UPSLOPE AREA OF WV...AND SLIGHTLY LESS OVER THE WRN FRINGES...AND LESS THAN A QUARTER INCH OVER SIX HOURS IN THE SHADOW AREA IN BETWEEN. MOMENTUM TRANSFER ALGORITHMS DO NOT MIX MUCH OF THE 70KTS SHOWN AT H85 OFF THE NAM12 TO THE SFC. THE STRONG INVERSION CREATED BY COOL ATLANTIC AIR FLOWING IN ON THE BACK SIDE OF A STRONG SFC HIGH SLIDING OFF THE NEW ENGLAND COAST...BENEATH WARMER AIR FLOWING IN ON SW MID LEVEL FLOW...WILL KEEP STRONG WIND GUSTS LIMITED TO THE VERY HIGHEST RIDGES. A NRN STREAM UPPER LEVEL LOW THEN DIGS INTO THE UPPER TROUGH...AS THE FINAL PIECE OF THE PUZZLE THAT ESTABLISHES A L/W TROUGH OVER THE ERN CONUS COME THU. A SFC LOW DEEPENS RAPIDLY WED IN RESPONSE TO THE DIGGING UPPER LEVEL LOW...AND PULLS QUICKLY NEWD...REACHING JAMES BAY IN CENTRAL CANADA BY THU MORNING. THIS PULLS A STRONG SFC COLD FRONT THROUGH THE AREA LATE WED INTO WED NT...FOLLOWED BY STRONG COLD ADVECTION INTO THU. THIS RESULTS IN GOOD MIXING THROUGH WED NT AND THU...ONCE THE LOW LEVEL INVERSION IS TAKEN OUT ON WED. THIS ALSO DRIES OUT THE WEATHER...AND STRONGER WIND GUSTS ARE REALIZED ON THU. THU EVENING FINDS THE L/W ALREADY LIFTING OUT THROUGH THE NERN STATES. TEMPERATURES TAKE A NON DIURNAL ROLLER COASTER RIDE...STEADY OR SLOWLY RISING ON TUE NT...AND THEN NEARLY STEADY IN THE COLD ADVECTION DURING THE DAY ON THU AS H85 TEMPERATURES DROP ABOUT 5C. USED MOSTLY TO NAM BASED GUIDANCE. HIGHS ARE NEAR THE LOW END OF THE GUIDANCE ENVELOP ON WED AND THE HIGH END ON THU WITH BETTER MIXING AND INCREASING SUNSHINE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE UPPER TROF LIFTS AS QUICKLY AS IT ARRIVED THURSDAY NIGHT...TO BE REPLACED BY BUILDING HEIGHTS. THIS IS ALL IN RESPONSE TO A BUILDING RIDGE OVER THE W ATLANTIC. WHILE THIS WILL ENSURE DRY WX THRU SATURDAY...THE END OF THE WEEKEND AND EARLY NEXT WEEK LOOKS UNSETTLED. THE CULPRIT BEING AN UPPER LOW EJECTING OUT OF THE SW CONUS AND INTERACTING WITH THE N STREAM. GLOBAL MODEL SOLUTIONS VARY WITH AXIS OF THE UPPER RIDGE WHICH WILL BE CRUCIAL IN DETERMINING JUST HOW WET WET GET. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... EXTENSIVE AREAS OF RAIN AND CLOUD COVER EXPECTED WITH A DEVELOPING LOW PRESSURE SYSTEM TAPPING INTO GULF MOISTURE OVER THE NEXT 30 HOURS. WILL SEE SOME EXPECTED DROPS IN FLIGHT CATEGORIES AS THE RAIN OVERSPREADS THE CENTRAL APPALACHIANS AND MIDDLE OHIO VALLEY. SOUTHEAST DOWNSLOPING FOR THE LOWLAND SITES WILL AID IN KEEPING CATEGORIES FROM DROPPING BELOW MVFR FOR BOTH CEILINGS AND VISIBILITIES. IN FACT...VFR WILL MAKE APPEARANCES HERE AND THERE. OVER THE MOUNTAINS IN THE SOUTHEAST MOIST UPSLOPE...WILL KEEP BKW MVFR DUE TO THE STRENGTH OF THE UPSLOPE FLOW. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: TIMING OF SHOWERS MAY VARY. TIMING OF MVFR ARRIVAL MAY VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE TUE 10/27/15 UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 EDT 1HRLY 23 00 01 02 03 04 05 06 07 08 09 10 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H M M BKW CONSISTENCY H H H H H H M M M M M M EKN CONSISTENCY H H H H H M M M M M H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z WEDNESDAY... INCREASING SOUTHEAST WIND TUESDAY NIGHT INTO WEDNESDAY WILL LIKELY LEAD TO IFR CIGS ALONG THE EASTERN SLOPES. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ/30 NEAR TERM...MZ/26 SHORT TERM...TRM LONG TERM...30 AVIATION...26
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1258 AM CDT TUE OCT 27 2015 .AVIATION... ALL TERMINALS ARE CURRENTLY VFR. DEL RIO AND SAN ANTONIO WILL REMAIN VFR THROUGH THIS PERIOD. THE DEW POINT DEPRESSION AT AUS IS ALREADY ONLY TWO DEGREES...SO I THINK FOG WILL FORM IN THE NEXT FEW HOURS REDUCING VIS TO MVFR UNTIL AFTER SUNRISE. OTHERWISE THEY WILL BE VFR. WINDS WILL BE LIGHT TODAY SHIFTING TO SOUTHWESTERLY THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 252 PM CDT MON OCT 26 2015/ SHORT TERM (TONIGHT THROUGH TUESDAY)... NO HIGHLIGHTS OR HAZARDS EXPECTED THROUGH THE NEXT FEW DAYS WITH A DRY AIRMASS IN PLACE AS NEAR NORMAL TEMPERATURES ARE EXPECTED. CURRENT WATER VAPOR AND RAP ANALYSIS DEPICT A STRONG CLOSED MID LEVEL LOW TRAVERSING EAST ACROSS THE NORTHERN GULF OF MEXICO AWAY FROM THE REGION. FARTHER UPSTREAM TO THE WEST...A DAMPENED TROUGH IS SHIFTING ACROSS THE INTER-MOUNTAIN WEST THAT WILL EVENTUALLY BRING A WEAK FRONT TOWARDS THE REGION BY MID WEEK. FOR TODAY...WINDY AND WARM TEMPERATURES ARE ONGOING AS A TIGHT PRESSURE GRADIENT EXISTS FROM WEST TO EAST TOWARDS THE AFOREMENTIONED LOW PRESSURE SYSTEM IN THE GULF. WINDS WILL GUST TO 20-25 MPH AT TIMES AS TEMPS MAX OUT IN THE MID 70S TO LOW 80S. WINDS WILL DECREASE OVERNIGHT AS THE LOW PULLS AWAY AND WITH DEWPOINTS EXPECTED IN THE UPPER 40S AND LOW 50S OVERNIGHT WITH CLEARING SKIES...TEMPS WILL DROP INTO THE UPPER 40S IN THE HILL COUNTRY AND LOW TO MID 50S ACROSS THE I-35 CORRIDOR AND COASTAL PLAINS. A NEAR REPEAT OF CONDITIONS IS EXPECTED TOMORROW WITH SLIGHTLY WARMER MAX HIGHS AND LESS CLOUD COVER GIVEN DRIER VERTICAL PROFILES FROM MODEL SOUNDINGS. LONG TERM (WEDNESDAY THROUGH MONDAY)... OUR HAZARD FOCUS THIS PERIOD WILL BE ON FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON AS ANOTHER POTENT STORM SYSTEM WILL APPROACH THE REGION. THE MAIN RISKS AT THIS POINT LOOK TO BE ANOTHER ROUND OF HEAVY RAIN BUT WILL NEED TO MONITOR EVOLUTION FOR OTHER POTENTIAL SEVERE WEATHER HAZARDS. BY MID-WEEK...NORTH WINDS WILL CONTINUE AS A WEAK DRY FRONT MOVES TOWARDS THE REGION DUE TO A WEAK SHORTWAVE TROUGH SHIFTING ACROSS THE SOUTHERN PLAINS. HOWEVER...BY THURSDAY...WINDS WILL BEGIN TO VEER TO THE EAST AND THEN SOUTHEAST AS THE RE-ESTABLISHING OF MOISTURE COMMENCES. A STRONG SIGNAL ACROSS THE ENSEMBLE SUITE OF GLOBAL MODELS INDICATES A POTENT MID-LVL TROUGH MOVING INTO NORTHERN MEXICO BY THURSDAY. THIS FEATURE...ALONG SIDE BROAD TROUGHING OVER THE PLAINS...WILL HELP INDUCE LEE-SIDE SURFACE CYCLOGENESIS THAT WILL AID IN DEEPER SOUTHERLY FLOW. BY MID-DAY FRIDAY...THE TROUGH OVER SOUTHERN ARIZONA WILL HAVE DEEPENED SUBSTANTIALLY TO NEAR 560 DM WHICH IS ABOUT 10DM DEEPER THAN THE PREVIOUS TROUGH THAT IMPACTED THE REGION. HOWEVER...WE WILL HAVE LESS MOISTURE TO WORK WITH THIS UPCOMING WEEKEND VS. THE PAST EVENT WHERE PWATS WERE UPWARDS OF 2.1-2.3" VS. THE PROGGED 1.8-1.9` (BUT STILL GOOD). THESE VALUES WILL STILL BE ADEQUATE ENOUGH FOR HEAVY RAIN AS SET-UP LOOKS TO BE SLIGHTLY STRONGER FORCED. IT IS TOO EARLY TO TELL IF THERE WILL BE MULTIPLE WAVES FRIDAY AFTERNOON AND AGAIN SATURDAY AS A POSSIBLE DRYLINE SURGE OCCURS OR IF IT WILL BE A MORE PROLONGED EVENT LATE FRIDAY INTO MID-DAY SATURDAY. LOOKING AT PROGGED CAPE/SHEAR COMBINATIONS AND SOUNDINGS...HEALTHY PARAMETERS APPEAR TO BE IN PLACE THAT COULD SUGGEST ORGANIZATION FOR A BROKEN QLCS ALONG A POSSIBLE DRYLINE SURGE SATURDAY MORNING TO MID-DAY. ANY ORGANIZATION THAT DOES OCCUR COULD AID IN STRONG WINDS AND POSSIBLY OTHER HAZARDS AS A 90-100 KT JET STREAK WILL SUPPORT STRONG UPPER-LEVEL DIVERGENCE NEAR AND NORTH OF THE REGION. WILL CONTINUE TO MONITOR THE SET-UP FOR OVERALL RAIN ACCUMULATION AMOUNTS AND SEVERE WEATHER HAZARD POSSIBILITIES. THE TIMING OF THE SYSTEM MOVING THROUGH BECOMES MURKY ON SUNDAY WITH EC SLOWER THAN THE PROGRESSIVE GFS. THE UKMET AND GEM FAVOR A SLOWER PATTERN WITH RAIN POSSIBLY LINGERING INTO SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 81 62 81 56 78 / 0 0 0 0 - AUSTIN BERGSTROM INTL AIRPORT 81 56 82 52 79 / 0 0 0 0 - NEW BRAUNFELS MUNI AIRPORT 82 59 85 55 80 / 0 0 0 0 - BURNET MUNI AIRPORT 79 57 78 53 76 / 0 0 0 0 - DEL RIO INTL AIRPORT 82 57 83 55 80 / 0 0 0 0 - GEORGETOWN MUNI AIRPORT 79 57 80 52 77 / 0 0 0 0 - HONDO MUNI AIRPORT 82 56 86 54 81 / 0 0 0 0 - SAN MARCOS MUNI AIRPORT 81 57 83 55 79 / 0 0 0 0 - LA GRANGE - FAYETTE REGIONAL 80 58 83 56 80 / 0 0 0 0 - SAN ANTONIO INTL AIRPORT 83 61 85 56 80 / 0 0 0 0 - STINSON MUNI AIRPORT 83 59 86 57 81 / 0 0 0 0 - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...HAMPSHIRE
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY ISSUED AT 342 AM CDT TUE OCT 27 2015 FOCUS IN THE SHORT TERM WILL CONTINUE TO BE ON THE TIMING AND DURATION OF STRATIFORM RAIN SHIELD FORECAST TO EVOLVE OVER THE FORECAST AREA...AS NORTHERN AND SOUTHERN STREAM ENERGY CONGEAL OVER THE UPPER MIDWEST AND GREAT LAKES REGION TONIGHT AND WEDNESDAY. IN THE MEANTIME...WEAK MID-LEVEL FRONTOGENETIC FORCING IN CONCERT WITH SUBTLE SHORTWAVE IMPULSES AND SOMEWHAT DEEPER MOISTURE CONTINUES TO GENERATE A PESKY NARROW BAND OF VERY LIGHT RAIN OR SPRINKLES CURRENTLY EXTENDING FROM NORTHCENTRAL WISCONSIN TO NORTHERN MINNESOTA. RAP SEEMS TO HAVE CAPTURED THE BASIC EVOLUTION OF THIS VERY LIGHT PRECIPITATION BAND AND CARRIES IT NORTHWARD INTO UPPER MICHIGAN BY 14 OR 15Z THIS MORNING WHICH SEEMS REASONABLE BASED ON CURRENT TRENDS. NOT GOING TO INCLUDE MENTION OF ANY POPS THIS MORNING FOR THE FAR NORTH AS MEASURABLE AMOUNTS ARE DUBIOUS AT THIS POINT. OTHERWISE...FOR THE REMAINDER OF TODAY EXPECT LOTS OF MID-LEVEL CLOUDINESS WITHIN BROAD AREA OF WEAK ISENTROPIC LIFT. ACROSS NORTHERN WISCONSIN...EXPECT MORE IN THE WAY OF LOW CLOUDS AND SOME PATCHY FOG FOR AT LEAST A COUPLE MORE HOURS EARLY THIS MORNING. DESPITE LOTS OF CLOUDS...TEMPERATURES WILL REMAIN WELL ABOVE NORMAL FOR LATE OCTOBER WITH READINGS MAINLY IN THE 55 TO 60 DEGREE RANGE. THEN FOCUS SHIFTS TO THIS EVENING AND OVERNIGHT...AS SHORTWAVE ENERGY OVER THE CENTRAL PLAINS GRADUALLY CONGEALS WITH MORE POTENT SHORTWAVE DROPPING OUT OF CANADA. SOMEWHAT SURPRISINGLY...SEEMS TO BE FAIRLY DECENT CONSENSUS AMONG THE MODEL GUIDANCE ON THE OVERALL EVOLUTION OF THIS SYSTEM OVER THE NEXT 24 TO 36 HOURS AS PRIMARY UPPER-LOW DEEPENS OVER WESTCENTRAL MINNESOTA AND SURFACE CYCLOGENESIS RAPIDLY COMMENCES OVER THE UPPER MIDWEST DURING THE DAY ON WEDNESDAY. CONSENSUS OF MODEL GUIDANCE TAKES DEEPENING SURFACE LOW SITUATED NEAR DVN BY 06Z WEDNESDAY...NORTHEAST TO NEAR GRB BY 15Z WEDNESDAY. DURING THIS PERIOD...HUGE SLUG OF DEEP MOISTURE OVER THE SOUTHERN AND CENTRAL MISSISSIPPI WILL ALSO BE RAPIDLY DRAWN NORTHWARD INTO WISCONSIN WEDNESDAY EVENING AS 850 MB SOUTHERLY WINDS INCREASE TO 30 TO 40 KTS. LEADING EDGE OF PRIMARY PRECIPITATION SHIELD SHOULD BEGIN TO IMPACT OUR SOUTHERN TIER OF COUNTIES AROUND 00Z WEDNESDAY...THEN STEADILY SPREAD NORTHWARD OVERNIGHT. INCREASING PRESSURE GRADIENT ON THE NORTH SIDE OF THE DEEPENING SURFACE LOW WILL ALSO LEAD TO INCREASING SOUTHEASTERLY BOUNDARY LAYER WINDS TUESDAY NIGHT INTO EARLY WEDNESDAY. STRONGEST QG FORCING AND DEEP LAYER LIFT EXPECTED TO MOVE ACROSS THE FORECAST AREA ROUGHLY BETWEEN ABOUT 06Z AND 15Z WEDNESDAY...WHEN THE BULK OF THE RAINFALL WILL OCCUR. FORTUNATELY THIS SYSTEM WILL BE RATHER PROGRESSIVE WITH THE BULK OF THE PRECIPITATION MOVING NORTHEAST OF THE FORECAST AREA BY AROUND 00Z THURSDAY AS MID-LEVEL DRY INTRUSION AND STRONG SUBSIDENCE PUSH ACROSS THE SOUTHERN HALF OF WISCONSIN. RAINFALL AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE...WITH STORM TOTAL PRECIPIATION AMOUNTS APPROACHING THREE QUARTER TO PERHAPS AN INCH LOCALLY OVER THE SOUTHWEST PORTION OF THE FORECAST AREA. LOOKS LIKE THE ENTIRE FORECAST AREA SHOULD SEE A DECENT SOAKING RAIN. .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY ISSUED AT 342 AM CDT TUE OCT 27 2015 SIGNIFICANT STORM EXPECTED TO MOVE ACROSS THE REGION WEDNESDAY AND THEN SLOWLY MOVE AWAY FROM THE REGION WEDNESDAY NIGHT AND THURSDAY. SOME SIGNIFICANT DIFFERENCES NOTED IN HOW MUCH COLD AIR GETS WRAPPED INTO THE SYSTEM ACROSS THE NORTH WEDNESDAY NIGHT WHICH WOULD HAVE AN IMPACT ON PRECIPITATION TYPES AND AMOUNT OF SNOW THE FAR NORTH WOULD RECEIVE. GFS IS SLOWER WITH COLDER AIR MOVING INTO THE NORTH...MAINLY LATE EVENING AND OVERNIGHT. THE ECMWF ON THE OTHER HAND WOULD SUGGEST SNOW WOULD START DURING THE EARLY EVENING HOURS AND CONTINUE INTO THURSDAY MORNING. 850MB WINDS WILL BECOME VERY FAVORABLE AT 340 DEGREES FOR LAKE ENHANCEMENT SNOW SHOWERS ACROSS THE NORTH IF THE COLDER AIR MATERIALIZES. LATER SHIFTS WILL NEED TO MONITOR THIS AND MAY NEED ADJUST SNOWFALL TOTALS ACCORDINGLY ONCE MODELS CONVERGE ] ON THE TIMING OF THE COLD AIR. FLURRIES MAY BE SEEN AS FAR SOUTH AS WISCONSIN RAPIDS TO THE FOX VALLEY LATE WEDNESDAY NIGHT BUT NO ACCUMULATION IS EXPECTED IN THIS REGION. GUSTY WESTERLY WINDS OF 30 TO 40 MPH CAN BE EXPECTED WEDNESDAY NIGHT INTO THURSDAY BEHIND THE DEPARTING SYSTEM. INCREASED RAIN CHANCES ACROSS THE AREA DUE TO COLD CYCLONIC FLOW AND WEAK DISTURBANCE MOVING ACROSS THE REGION. DO EXPECT INSTABILITY RAIN SHOWERS...WITH SNOW ACROSS THE NORTH DURING THE MORNING. THE SHOWERS WILL GRADUALLY DIMINISH DURING THE LATE AFTERNOON HOURS. THE NEXT CHANCE OF RAIN WILL OCCUR FRIDAY NIGHT AND SATURDAY AS A COLD FRONT MOVES ACROSS THE STATE. BEYOND THIS PERIOD...NO REAL SIGNIFICANT CHANCES FOR RAIN. MAIN STORY WILL BE THE ABOVE NORMAL TEMPERATURES EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1047 PM CDT MON OCT 26 2015 DESPITE RAIN ENDING AND A SHORTWAVE PULLING OUT OF THE REGION...LIFR CONDITIONS CONTINUE AT THE RHI SITE. GIVEN THE LACK OF A STRONG PUSH OF DRY AIR AT THE LOWER LEVELS WILL KEEP LIFR CONDITIONS IN THROUGH TUESDAY MORNING WHEN WINDS PICK UP AHEAD OF THE NEXT LOW PRESSURE SYSTEM APPROACHING FROM THE WEST. AT THE REST OF THE TAF SITES...MID CLOUDS WILL CONTINUE WITH SOME PATCHY MVFR FOG EXPECTED LATE TONIGHT AND INTO TUESDAY MORNING. RAIN FROM THE NEXT SYSTEM WILL SPREAD INTO THE AREA FROM SOUTH TO NORTH...WITH THE SOUTHERN TAF SITES LIKELY SEEING RAIN TUESDAY EVENING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ESB LONG TERM......ECKBERG AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
437 AM PDT TUE OCT 27 2015 .SYNOPSIS...MOSTLY CLOUDY SKIES TODAY AHEAD OF AN INCOMING WEATHER SYSTEM THAT MAY PRODUCE A FEW SHOWERS OR LIGHT SPRINKLES OVER THE NORTH BAY THIS AFTERNOON. LIGHT RAIN CHANCES INCREASE OVERNIGHT INTO WEDNESDAY MORNING AS THE MAIN COLD FRONT WILL PASS THROUGH THE STATE WITH THE BEST CHANCE OF RAIN FOR THE NORTH BAY. MORNING LIGHT RAIN TURNS TO SHOWERS BY WEDNESDAY AFTERNOON BEFORE ENDING. HIGH PRESSURE BUILDS THURSDAY THROUGH HALLOWEEN WITH DRY AND MILD WEATHER ALONG WITH SOME BREEZY NORTH WINDS IN THE HILLS. A COLDER TROUGH MAY ARRIVE FROM THE NORTH BY SUNDAY OR MONDAY WITH THE NEXT CHANCE OF RAIN. && .DISCUSSION...AS OF 4:04 AM PDT TUESDAY...LOTS OF HIGH CLOUDS OVER THE REGION THIS MORNING AHEAD OF THE FRONTAL BOUNDARY OVER THE EASTERN PACIFIC. THERE WAS SOME MORE WIDESPREAD DENSE FOG BEFORE MIDNIGHT BUT THE CLOUD COVER HAS SHUT DOWN THE RADIATIONAL FOG WITH ONLY WATSONVILLE CURRENTLY REPORTING 1/4 MILE. THE HRRR AND RAP MODELS SHOW A FEW SCOUT SHOWERS TODAY IN THE NORTH BAY BUT EXPECTING ONLY TRACE AMOUNTS WITH ISOLATED SHOWERS/SPRINKLES. SKIES STAY CLOUDY TODAY THROUGH TONIGHT WITH HIGHS STILL IN THE 70S FOR MOST OF THE DISTRICT. LONG TALKED ABOUT FRONTAL BOUNDARY WILL FINALLY ARRIVE LATE TONIGHT INTO WEDS MORNING. IN GENERAL RAIN TOTALS HAVE BACKED OFF WITH THE BEST CHANCES APPEARING TO BE FOR THE NORTH BAY WEDS MORNING WHEN 0.10-0.25 IS POSSIBLE. THERE`S NO COLD ADVECTION OR GOOD FORCING WITH MAIN JET ENERGY STAYING TO OUR NORTH. SOME HIT AND MISS SHOWERS ALSO FORECAST OVER THE GREATER BAY AREA AND DOWN TO AROUND MONTEREY BAY ON WEDS BUT IN GENERAL RAINFALL IS LOOKING LIGHT AND SPORADIC WITH AREAS SOUTH OF SALINAS EXPECTED TO RECEIVE LITTLE OR NO RAINFALL. ANY SHOWERS WILL QUICKLY END BY WEDS EVENING. HIGH PRESSURE WILL QUICKLY REBUILD ON THURSDAY WITH DRY AND MILD WEATHER RETURNING. OFFSHORE PRESSURE GRADIENTS WILL SET UP WITH SOME MODERATE NORTHEAST WINDS DEVELOPING ACROSS THE BAY AREA HILLS. IF THE MIDWEEK RAINS DONT DEVELOP AS EXPECTED FIRE WEATHER CONCERNS WILL MAY BECOME FRONT AND CENTER WITH A FAIRLY CLASSIC FALL OFFSHORE WIND PATTERN IN PLACE AS THE THERMAL TROUGH STRADDLES THE COAST. THE GRADIENT RELAXES LATER FRIDAY INTO SATURDAY BUT EXPECT CLEAR SKIES AND SEASONABLY WARM WEATHER FROM THE 70S TO MID 80S WITH DOWNSLOPE WARMING OFF THE HILLS. MODELS BEING CONSISTENT IN SHOWING A COLD TROUGH FROM THE NORTH BY NEXT SUNDAY INTO MONDAY WITH COOLER TEMPERATURES AND A CHANCE OF RAIN. && .AVIATION...AS OF 4:30 AM PDT TUESDAY...DRIER AIR OVER THE SFO BAY AREA THIS MORNING WITH RH AS MUCH AS 20-30% LOWER THAN YESTERDAY MORNING. PATCHY CIGS IN THE MRY BAY AREA MAINLY AROUND SNS SHOULD CLEAR EARLY. VICINITY OF KSFO...VFR. WEST WINDS GUSTING TO 18 KT AFTER 20Z. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...AREAS OF LIFR CONDITIONS WITH VSBYS AS LOW AS 2-3 MILES THROUGH 15Z. && .MARINE...AS OF 03:07 AM PDT TUESDAY...A WEAK UPPER LEVEL TROUGH WILL MOVE THROUGH THE AREA WEDNESDAY THEN DEEPEN OVER THE WESTERN INTERIOR. AS A RESULT NORTHWEST WINDS WILL INCREASE THURSDAY THROUGH FRIDAY. WINDS WILL DECREASE THIS WEEKEND AS THE TROUGH MOVES EAST. A LONG PERIOD SWELL WILL MOVE INTO THE AREA WEDNESDAY AND CONTINUE THROUGH THURSDAY. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. && $$ PUBLIC FORECAST: RWW AVIATION: W PI MARINE: W PI VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
404 AM PDT TUE OCT 27 2015 .SYNOPSIS...MOSTLY CLOUDY SKIES TODAY AHEAD OF AN INCOMING WEATHER SYSTEM THAT MAY PRODUCE A FEW SHOWERS OR LIGHT SPRINKLES OVER THE NORTH BAY THIS AFTERNOON. LIGHT RAIN CHANCES INCREASE OVERNIGHT INTO WEDNESDAY MORNING AS THE MAIN COLD FRONT WILL PASS THROUGH THE STATE WITH THE BEST CHANCE OF RAIN FOR THE NORTH BAY. MORNING LIGHT RAIN TURNS TO SHOWERS BY WEDNESDAY AFTERNOON BEFORE ENDING. HIGH PRESSURE BUILDS THURSDAY THROUGH HALLOWEEN WITH DRY AND MILD WEATHER ALONG WITH SOME BREEZY NORTH WINDS IN THE HILLS. A COLDER TROUGH MAY ARRIVE FROM THE NORTH BY SUNDAY OR MONDAY WITH THE NEXT CHANCE OF RAIN. && .DISCUSSION...AS OF 4:04 AM PDT TUESDAY...LOTS OF HIGH CLOUDS OVER THE REGION THIS MORNING AHEAD OF THE FRONTAL BOUNDARY OVER THE EASTERN PACIFIC. THERE WAS SOME MORE WIDESPREAD DENSE FOG BEFORE MIDNIGHT BUT THE CLOUD COVER HAS SHUT DOWN THE RADIATIONAL FOG WITH ONLY WATSONVILLE CURRENTLY REPORTING 1/4 MILE. THE HRRR AND RAP MODELS SHOW A FEW SCOUT SHOWERS TODAY IN THE NORTH BAY BUT EXPECTING ONLY TRACE AMOUNTS WITH ISOLATED SHOWERS/SPRINKLES. SKIES STAY CLOUDY TODAY THROUGH TONIGHT WITH HIGHS STILL IN THE 70S FOR MOST OF THE DISTRICT. LONG TALKED ABOUT FRONTAL BOUNDARY WILL FINALLY ARRIVE LATE TONIGHT INTO WEDS MORNING. IN GENERAL RAIN TOTALS HAVE BACKED OFF WITH THE BEST CHANCES APPEARING TO BE FOR THE NORTH BAY WEDS MORNING WHEN 0.10-0.25 IS POSSIBLE. THERE`S NO COLD ADVECTION OR GOOD FORCING WITH MAIN JET ENERGY STAYING TO OUR NORTH. SOME HIT AND MISS SHOWERS ALSO FORECAST OVER THE GREATER BAY AREA AND DOWN TO AROUND MONTEREY BAY ON WEDS BUT IN GENERAL RAINFALL IS LOOKING LIGHT AND SPORADIC WITH AREAS SOUTH OF SALINAS EXPECTED TO RECEIVE LITTLE OR NO RAINFALL. ANY SHOWERS WILL QUICKLY END BY WEDS EVENING. HIGH PRESSURE WILL QUICKLY REBUILD ON THURSDAY WITH DRY AND MILD WEATHER RETURNING. OFFSHORE PRESSURE GRADIENTS WILL SET UP WITH SOME MODERATE NORTHEAST WINDS DEVELOPING ACROSS THE BAY AREA HILLS. IF THE MIDWEEK RAINS DONT DEVELOP AS EXPECTED FIRE WEATHER CONCERNS WILL MAY BECOME FRONT AND CENTER WITH A FAIRLY CLASSIC FALL OFFSHORE WIND PATTERN IN PLACE AS THE THERMAL TROUGH STRADDLES THE COAST. THE GRADIENT RELAXES LATER FRIDAY INTO SATURDAY BUT EXPECT CLEAR SKIES AND SEASONABLY WARM WEATHER FROM THE 70S TO MID 80S WITH DOWNSLOPE WARMING OFF THE HILLS. MODELS BEING CONSISTENT IN SHOWING A COLD TROUGH FROM THE NORTH BY NEXT SUNDAY INTO MONDAY WITH COOLER TEMPERATURES AND A CHANCE OF RAIN. && .AVIATION...AS OF 10:25 PM PDT MONDAY...TRICKY FORECAST WITH LOW CLOUDS INCREASING ACROSS THE AREA WHILE HIGH CLOUDS MOVE OVERHEAD IN ADVANCE OF AN APPROACHING SYSTEM. WILL GO MODERATELY PESSIMISTIC BASED ON CURRENT SURFACE REPORTS. BURN-OFF SLATED FOR AFTER 16Z. WINDS SHOULD NOT BE A FACTOR AND WILL MOSTLY STAY UNDER 10 KT BY 07Z AND CONTINUE THROUGH TUESDAY MORNING. LOW CONFIDENCE. VICINITY OF KSFO...LOW CLOUDS ONLY FORECAST TO DROP SFO DOWN TO MVFR CONDITIONS OVERNIGHT WITH CIGS AROUND 015. WINDS WILL DROP TO UNDER 10 KT AFTER 07Z. VFR RETURNS AFTER 17Z. LOW TO MODERATE CONFIDENCE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...VLIFR TO LIFR CONDITIONS OVERNIGHT WITH CIGS DOWN TO 002 AND VIS OF POTENTIALLY LESS THAN 1/2 SM. WINDS UNDER 10 KT THROUGH TUESDAY MORNING. LOW CONFIDENCE. && .MARINE...AS OF 03:07 AM PDT TUESDAY...A WEAK UPPER LEVEL TROUGH WILL MOVE THROUGH THE AREA WEDNESDAY THEN DEEPEN OVER THE WESTERN INTERIOR. AS A RESULT NORTHWEST WINDS WILL INCREASE THURSDAY THROUGH FRIDAY. WINDS WILL DECREASE THIS WEEKEND AS THE TROUGH MOVES EAST. A LONG PERIOD SWELL WILL MOVE INTO THE AREA WEDNESDAY AND CONTINUE THROUGH THURSDAY. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. && $$ PUBLIC FORECAST: RWW AVIATION: W PI MARINE: W PI VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
658 AM CDT TUE OCT 27 2015 .SHORT TERM...(Today) ISSUED AT 324 AM CDT TUE OCT 27 2015 08z/3am surface analysis shows ridge of high pressure extending from New England southwestward to the Central Plains...while a 1005mb low continues to spin over Louisiana. Showers from the Gulf Coast low have been slowly spreading northward over the past several hours, but have been encountering a very dry mid/low-level airmass beneath the surface ridge as evidenced by the 00z KILX upper air sounding and current surface dewpoints in the middle to upper 30s across the northern half of the CWA. This dry air has been impeding the northward progress of the precip...with 08z/3am radar imagery and surface obs indicating very light showers/sprinkles confined to locations along and south of a Litchfield to Paris line. HRRR has a decent handle on the current situation and suggests light rain will likely not make it north of the Peoria area until after sunrise. Have therefore cut back PoPs early this morning, especially across the far N/NW CWA where dry air will delay precip onset. Once the airmass moistens sufficiently and an upper-level trough approaching from the west provides increasing synoptic lift, rain will become widespread across the entire area by mid to late morning through the afternoon. Thanks to the rain and a brisk easterly wind of 10 to 15mph, high temperatures today will be considerably cooler than yesterday with readings remaining in the 50s in most locations. .LONG TERM...(Tonight through Monday) ISSUED AT 324 AM CDT TUE OCT 27 2015 Rain will continue tonight as the Louisiana low tracks northward across central Illinois. Forecast soundings remain quite stable, but do show modest elevated instability as the upper trough arrives. Think this may be just enough to produce a rumble or two of thunder, so will continue to mention isolated thunderstorms tonight. As the low lifts into the Great Lakes, showers will gradually diminish from southwest to northeast on Wednesday. Total rainfall with this system will generally be around 1 inch...with higher totals of 1 to 2 inches focused along/east of the I-57 corridor into the Ohio River Valley. Thanks to deepening surface low pressure over the Great Lakes and an approaching deep upper low, Thursday is shaping up to be the coolest day of the forecast period. Cloud cover associated with the upper system will likely remain just north of the CWA across northern Illinois. Despite abundant sunshine, brisk W/NW winds gusting to around 25mph will create a distinct chill as high temperatures struggle to reach the lower to middle 50s. After a very cool night Thursday night with lows dipping into the lower to middle 30s, temperatures will begin to rebound well into the 50s on Friday as high pressure drifts across the area. Models are still having trouble resolving the next potential system over the weekend. An upper low is expected to dive into the Desert Southwest on Friday, then slowly track E/NE through early next week. Exactly how quickly this process unfolds remains in question, as the models differ on how amplified the low will become. The 00z Oct 27 GEM is the deepest and furthest south with the low, keeping it over northwest Mexico until finally ejecting it northeastward into the Midwest by Tuesday. Meanwhile, the GFS and ECMWF are both more progressive...with the GFS tracking the low across the area on Sunday and the ECMWF on Monday. Given the considerable model spread, have opted to make few changes to the going forecast which follows the GFS closely. As a result, have introduced chance PoPs late Friday night into Saturday as a northern-stream wave approaches from the Northern Plains and have continued PoPs through Sunday night as the Desert Southwest low ejects northeastward. Have then gone with a dry forecast for Monday. Will need to watch future model trends closely...as further adjustments will likely be needed for the PoP forecast over the upcoming weekend. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 658 AM CDT TUE OCT 27 2015 Widespread MVFR ceilings are in place across central IL this morning with areas of showers providing IFR vsby/cigs. Isolated LIFR as well. Conditions will tend to deteriorate through this evening as responsible low pressure system continues to approach. Isolated TSRA possible overnight, but probability too low for mention in TAFS at this time. Widespread LIFR cigs/IFR vsby expected by 00Z. Winds E 10-15 kts with higher gusts during the afternoon hours. Winds veering to S-SW after 09Z- 12Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Onton
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1156 AM EDT TUE OCT 27 2015 .SYNOPSIS... STRONG LOW PRESSURE WILL BRING RAIN THROUGH WEDNESDAY NIGHT. SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE REST OF THE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... MOISTURE WILL CONTINUE TO INCREASE FROM THE SOUTH AHEAD OF THE REMNANTS OF PATRICIA. A RELATIVELY LONG PERIOD OF WET CONDITIONS WILL BE LIKELY OVER THE NEXT COUPLE OF DAY AS THE MOISTURE FROM THE REMNANTS GET ABSORBED BY A VERY DEEP CLOSED UPPER LOW THAT WILL MOVE FROM THE GREAT LAKES THROUGH THE NORTHEAST THIS WEEK. DEEP SOUTHEASTERLY FLOW WILL INCREASE GOING INTO THE EVENING AS MOISTURE INCREASES. MULTI-MODEL CONSENSUS VALUES SUGGEST THE LOW LEVEL JET MAXIMA MAY WELL APPROACH 60-70 KTS FROM THE SOUTHEAST OVERNIGHT TONIGHT INTO WEDNESDAY MORNING. ADDITIONALLY...MODEL SOUNDINGS FAVOR INVERSION HEIGHTS SLIGHTLY ABOVE THE RIDGETOPS WITH SOUTHEASTERLY FLOW BEING PERPENDICULAR TO THE RIDGELINES. THIS COMBINED WITH FAIRLY UNSTABLE CONDITIONS BELOW THE INVERSION HEIGHTS...AS WELL AS PRECIPITATION DRAG WILL LIKELY MIX DOWN A FAIR AMOUNT OF WIND GUSTS. EVEN BELOW THE INVERSION LEVEL...NAM CONUS NEST PLOTS AND HRRR VALUES SUGGEST 45-55 KTS OF WIND GUST POTENTIAL IN CHESTNUT/LAUREL RIDGES AS WELL AS DOWNSLOPE MOUNTAIN WAVE WIND GUST POTENTIAL TO THE WEST OF THE RIDGES. DUE TO THE ORIENTATION OF THE TOPOGRAPHY RELATIVE TO THE FLOW...THIS FAVORS WIND GUST POTENTIAL PRIMARILY IN FAYETTE AND WESTMORELAND COUNTIES...AS WELL AS FAR SOUTHEASTERN INDIANA COUNTY. THE POTENTIAL IS A BIT LESS IN WEST VIRGINIA AND MARYLAND. THAT SAID...WITH GUSTS TO 50 MPH IN THE FORECAST...A WIND ADVISORY HAS BEEN ISSUED FOR WESTMORELAND AND FAYETTE COUNTIES. AS FLOW TURNS MORE SOUTHERLY ON WEDNESDAY IN ADVANCE OF THE APPROACHING WAVE...MOUNTAIN WAVE GUST POTENTIAL DECREASES SUBSTANTIALLY AS THE FLOW DIRECTION CHANGES AND THE LOW LEVEL JET LIFTS NORTHWARD. HOWEVER...AHEAD OF THE INCOMING FRONTAL BOUNDARY...DEEPER STEEP LAPSE RATES MOVE IN FROM THE WEST. THIS WILL ALLOW FOR THE RAIN SHADOW TO THE WEST OF THE RIDGES TO BE ERADICATED AS DEEPER LIFT ASSOCIATED WITH THE INCOMING JET STREAK AND DIFFERENTIAL PVA COUPLED WITH SKINNY CAPE ALONG THE FRONT MAY ALLOW FOR SOME THUNDERSTORM DEVELOPMENT. SHOULD A DECENT LINE FORM ALONG THE FRONT...GIVEN THE MOMENTUM IN THE COLUMN...A SEVERE WIND GUST OR TWO WILL BE POSSIBLE BY LATE AFTERNOON AND EVENING. SPC HAS OUTLINED THIS POSSIBILITY WITH A MARGINAL RISK...AND GIVEN THE LACK OF INSTABILITY...THIS SEEMS A PRAGMATIC APPROACH. A SLIGHT CHANCE OF THUNDERSTORMS WAS INCLUDED IN THE FORECAST...HOWEVER THE CHANCES OF SEVERE WEATHER DO NOT LOOK OVERLY IMPRESSIVE AT THIS TIME. IN ADVANCE OF THE SYSTEM OVERNIGHT...TEMPERATURES MAY WELL RISE DUE TO INCREASING MIXING...AND CONTINUE TO WARM ON WEDNESDAY MORNING AHEAD OF THE COLD FRONT. A FEW SPOTS MAY WELL TOUCH 70F BEFORE THE FRONT CROSSES AS THE UPPER LOW DROPS OVERHEAD LATER IN THE WEEK. FRIES && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/... A SECONDARY COLD FRONT WILL CROSS EARLY THURSDAY MORNING... NECESSITATING THE INCLUSION OF CHANCE POPS UNTIL ITS EXIT. HAVE INCREASED WINDS ALONG AND DIRECTLY BEHIND THE COLD FRONT AS BUFKIT SOUNDINGS SHOW A DEEP MIXING LAYER AND PLENTY OF WIND JUST ABOVE THE SURFACE. DO NOT EXPECT THE STRONGEST WINDS TO MIX DOWN TO THE SURFACE...AS BOUNDARY LAYER STABILIZES...BUT IT WILL BE RATHER GUSTY FOR A TIME ON THURSDAY. ONCE THE SHOWERS END THURSDAY MORNING...EXPECT A DRY REMAINDER OF THE DAY...WITH DECREASING CLOUD COVER. THURSDAY LOOKS LIKE A DAY OF NEARLY STEADY TEMPERATURES WITH THE STRONG COLD AIR ADVECTION BEHIND THE FRONT. HIGHS THURSDAY WILL LIKELY BE AIDED SOMEWHAT BY THE LATE OCTOBER SUN. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... A PROGRESSIVE FLOW PATTERN SHOULD RESULT IN A VARIABLE LONG TERM PERIOD WITH SHORTWAVE RIDGING FORECAST TO PROVIDE A DRY START TO THE WEEKEND...BUT ANOTHER TROUGH MOVING OUT OF THE MIDWEST IS TIMED TO DETERIORATE CONDITIONS WITH RAIN BY SUNDAY. SHORTWAVE RIDGING WOULD AGAIN DRY THE PROGNOSIS EARLY IN THE NEW WORK-WEEK. THE LONG TERM FORECAST WAS CONSTRUCTED USING A BLEND OF WPC AND GFSMOS GUIDANCE AND GENERALLY FEATURES CLIMO POPS AND TEMPS AT...OR A FEW DEGREES ABOVE THE AVERAGES. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE DAY ALTHOUGH LIGHT RAIN IS EXPECTED TO ENCROACH FROM THE SOUTH AS THE AFTN PROGRESSES. CONDITION DETERIORATION CAN BE ANTICIPATED AFTER DARK AS THE LLVLS SATURATE. OUTLOOK...WEDNESDAY THROUGH SATURDAY/... LOW LEVEL WIND SHEAR AND RESTRICTIONS ARE LIKELY THROUGH THURSDAY AS STRONG LOW PRES CROSSES THE MIDWEST AND EASTERN CANADA AND PULLS A CDFNT ACRS THE REGION. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...WIND ADVISORY FROM 2 AM TO 11 AM EDT WEDNESDAY FOR PAZ073>076. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
736 AM EDT TUE OCT 27 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 518 AM EDT TUE OCT 27 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL TROUGH DEVELOPING FROM SASK/ALBERTA INTO THE NRN ROCKIES AND WRN PLAINS WITH SEVERAL EMBEDDED SHORTWAVES. DOWNSTREAM...A RIDGE WAS BUILDING FROM THE UPPER MS VALLEY TO THE WRN GREAT LAKES. A THE SFC...SE FLOW PREVAILED THROUGH THE REGION BTWN HIGH PRES OVER NRN ONTARIO AND QUEBEC AND A TROUGH OVER THE WRN PLAINS. A BAND OF LIGHT SHOWERS OR SPRINKLES ASSOCIAED WITH WAA AND 295K ISENTROPIC LIFT NORTH OF A SFC FRONT THROUGH SRN MN. OTHERWISE...IR LOOP SHOWED MID CLOUDS SPREADING ACROSS UPPER MI WHERE AREAS OF LOW CLOUDS AND PATCHY FOG HAD ALSO DEVELOPED. TODAY...RADAR TRENDS AND SHORT RANGE MODELS SUGGEST THAT THE AREA OF LIGHT PCPN FROM N CNTRL MN INTO NW WI WILL CONTINUE TO LIFT TO THE NNE WITH ONLY A FEW SPRINKLES POSSIBLE OVER THE FAR WEST BEFORE 15Z. OTHERWISE...DRIER AIR FROM 925-850 MB MOVING IN FROM THE SOUTH COMBINED WITH LIMITED DAYTIME HEATING/MIXING SHOULD HELP SCOUR OUR THE LOWER CLOUDS THIS MORNING. HOWEVER...MID LEVEL CLOUDS WILL CONTINUE TO THICKEN. NEVERTHELESS...WAA WILL HELP PUSH HIGH TEMPS INTO THE LOWER TO MID 50S. TONIGHT...THE MODELS WERE IN GOOD AGREEMENT WITH THE CNTRL PLAINS SHORTWAVE LIFTING TOWARD IA AS A STRONGER SHRTWV OVER CNTRL SASK DROP INTO SRN MANITOBA. A DEEPENING SFC LOW WILL ALSO LIFT TO SRN WI. INCREASING SRLY 80-700 MB FLOW TO 40-50 KNOTS WILL DRAW ABUNDANT MOISTURE TOWARD UPPER MI (PWAT TO AROUND 1.0 INCH) WITH RAIN SPREADING ACROSS THE CWA LATE...MAINLY BTWN 09Z-12Z. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 512 AM EDT TUE OCT 27 2015 DEEPENING LONGWAVE TROUGH OVER THE CENTRAL CONUS ON WEDNESDAY RESULTS FROM PHASING OF MANY INDIVIDUAL SHORTWAVES STRETCHING FROM BRITISH COLUMBIA THROUGH THE INTERMOUNTAIN WEST. AS TROUGH DEEPENS SFC LOW 995-1000MB DEVELOPS OVER IA/IL/SOUTHERN WI BY 12Z ON WED. MOIST ADVECTION OF PWATS OVER 1 INCH AHEAD OF H85 TROUGH AND SFC LOW ALONG WITH H85-H5 Q-VECTOR CONVERGENCE FM THE DEEPENING TROUGH SHOULD SPREAD THE RAIN CURRENTLY OVER LOWER MISSISSIPPI RIVER VALLEY ACROSS THE UPPER GREAT LAKES BY DAYBREAK ON WEDNESDAY. ISENTROPIC ASCENT 290-300K/H9-H65 ALONG WITH THE LARGER SCALE FORCING WITH SOME ADDITIONAL ASSIST TO RIGHT ENTRANCE REGION OF UPPER JET OVER ONTARIO WILL RESULT IN MODERATE RAIN OVER UPR MICHIGAN ON WEDNESDAY. AS THE ISENTROPIC ASCENT FADES IN THE MID-LATE AFTN AND Q-VECTOR DIVERGENCE SPREADS NORTH OVER CWA IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE EXPECT RAIN TO START TO DIMINISH. MID CONUS TROUGH CLOSES OFF SHARPLY INTO THURSDAY AS INITIAL CENTRAL CONUS TROUGH MOVING EAST PHASES WITH STRONG NORTHERN STREAM TROUGH DIGGING SSE FM SASKATCHEWAN AND MANITOBA ON WEDNESDAY MORNING TO THE WESTERN GREAT LAKES WEDNESDAY NIGHT. SFC LOW LIFTING FM THE MIDDLE MISSISSIPPI RIVER VALLEY DEEPENS TO NEAR 983-985MB AS IT REACHES SOUTH CENTRAL LK SUPERIOR WEDNESDAY EVENING THEN STAYS SIMILAR STRENGTH AS IT MOVES TO FAR EAST LK SUPERIOR OR JUST EAST OF LK SUPERIOR BY 12Z THURSDAY. TREND IS SLOWER IN MAJORITY OF GUIDANCE IN LIFTING THE LOW NORTH OF THE REGION. MAIN RESULT IS MORE WIDESPREAD PRECIP LINGERING OVER MUCH OF UPR MICHIGAN WEDNESDAY NIGHT INTO THURSDAY WITH TROWAL WORKING ACROSS WEST TO EAST AS SEEN IN THETA-E FIELDS WITH HEIGHT /ESPECIALLY H7-H6/ AND H7-H5 Q-VECTOR CONVERGENCE. ALSO SEE THE SLOWER TREND SHOW UP WITH WARMER AIR IN THE SFC-H85 LAYER ORIENTED EAST TO WEST ACROSS UPR MICHIGAN AND LK SUPERIOR. BIGGEST IMPACT IS ON SNOW POTENTIAL OVER WESTERN CWA. H85 TEMPS LAST NIGHT WERE AROUND -2C AT THE WARMEST AND -5C AT THE COOLEST BUT LATEST RUNS HAVE TRENDED WARMER. GFS/NAM SOUNDINGS AT IWD INDICATE EVEN WITH H85 TEMPS AROUND -2C OR -3C/GOOD ENOUGH FOR LAKE ENHANCEMENT WITH WATER TEMPS AROUND 8C AND PLENTY OF LARGE SCALE LIFT/MOISTURE/...WET BULB ZERO HEIGHTS REMAIN AT OR ABOVE 1000 FT AGL WHICH SUGGEST A MIX OF RAIN AND SNOW...BUT NOT MUCH SNOW ACCUMULATION. WILL BE TIGHT GRADIENT BTWN WHERE SNOW IS MAIN PYPE AND WHERE THERE WILL BE MIX OR JUST RAIN. RIGHT NOW BELIEVE THAT LINE WILL STAY MAINLY WEST AND SOUTH OF WESTERN CWA. TRENDED SNOW BACK OVER WESTERN INTERIOR TO LESS THAN 0.5 INCH. COOL AND BREEZY CONDITIONS EXPECTED ON THURSDAY ALL CWA. STRONGEST WINDS WILL BE ALONG LK SUPERIOR. SOLID 40-45 MPH IN THE MIXED LAYER THOUGH SLOWER TREND WITH SFC LOW AND LACK OF STRONG COLD AIR ADVECTION WILL COMPLICATE HOW QUICKLY THE STRONG WINDS MIX TO SFC. GOOD PORTION OF THESE WINDS WILL MAKE IT TO SFC AS GUSTS. GALES LOOK CERTAIN OVER LK SUPERIOR AND PROBABLY WILL NEED WIND ADVISORY HEADLINES ON ADJACENT SHORELINES OF NORTHERN UPR MICHIGAN. MOST FAVORED LOCATIONS TO SEE STRONGEST WINDS WOULD BE COPPER HARBOR AND MUNISING/GRAND MARAIS/FAR NORTHERN LUCE COUNTY. WINDS DIMINISH BY MIDNIGHT THURSDAY NIGHT. COOLEST AIR SETTLES ACROSS LK SUPERIOR ON THURSDAY NIGHT WITH H85 TEMPS DOWN TO -6C OR -7C. SOUNDINGS AT END OF FETCH OVER EASTERN LK SUPERIOR INDICATE SHALLOW MOIST LAYER AROUND H85 AND DRY SUB CLOUD LAYER. KEPT LOW CHANCES IN FOR LAKE EFFECT WITH SUFFICIENT OVERWATER INSTABILITY...BUT DRY AIR BLO CLOUD BASE AND FLOW BECOMING MORE ANTICYLONIC SHOULD ALLOW FOR DIMINISHING TREND TO LAKE EFFECT INTO FRIDAY. EXPECT SKIES TO STAY MOSTLY CLOUDY WITH INCREASING WARM AIR ADVECTION OCCURRING ATOP SHALLOW COLD LAYER. MID CLOUDS INCREASE IN THE AFTN AHEAD OF NEXT CHANCE OF RAIN WHICH ARRIVES OVERNIGHT FRIDAY NIGHT. GFS IS NOW JOINED BY ECMWF IN SHOWING SWATH OF RAIN SPREADING OVER UPPER GREAT LAKES LATE FRIDAY NIGHT INTO AT LEAST SATURDAY MORNING AHEAD OF SHORTWAVE TROUGH CROSSING THE NORTHERN PLAINS. STRONGEST LOW-LEVEL MOISTURE ADVECTION REMAINS MORE OVER CNTRL AND LOWER GREAT LAKES...SO LIKELY WILL NOT SEE TOO HIGH AMOUNTS OVER UPR MICHIGAN /AROUND 0.10 INCH BUT LESS THAN 0.25 INCH/. HALLOWEEN 2014 HAD SNOW OVER PARTS OF UPR MICHIGAN SO AT LEAST WILL NOT BE LOOKING AT ANYTHING THAT COLD. TEMPS ON SATURDAY TOP OUT IN THE UPR 40S TO NEAR 50 DEGREES. WARMING TREND STILL EXPECTED INTO FIRST PART OF NEXT WEEK WITH ONLY SMALL CHANCES OF RAIN AS IT STANDS NOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 734 AM EDT TUE OCT 27 2015 INCREASING SE FLOW WILL GRADUALY DRAW SOMEHWAT DRIER AIR INTO CNTRL UPPER MI. WITH THE ONSET OF LIMITED DAYTIME HEATING/MIXING CONDITIONS SHOULD IMPROVE TO MVFR BY LATE MORNING AT SAW AND TO VFR THIS AFTERNOON. ALTHOUGH ABUNDANT MID AND HIGH CLOUDS WILL PREVAIL OVER THE AREA...VFR CONDITIONS WILL CONTINUE AT IWD AND CMX. MORE CLOUDS AND SOME -RA WL ARRIVE FROM THE SW OVERNIGHT...BUT VFR CONDITIONS SHOULD PREVAIL THRU 06Z. CIGS SHOULD THEN DROP TO MVFR AT IWD AND CMX AND TO IFR AND SAW WHERE UPSLOPE FLOW DOMINATES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 525 AM EDT TUE OCT 27 2015 WINDS WILL BEGIN TO INCREASE TODAY INTO TONIGHT AHEAD OF A STRENGTHING LOW LIFTING TOWARD THE WRN LAKES. THE LOW WILL RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY LATE THIS AFTERNOON...INCREASING FURTHER TO 20-30KT TONIGHT. THE STRONGEST WINDS TONIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. WINDS WILL TEMPORARILY DIMINISH IN THE VNCTY OF THE LOW/FRONT AS THEY MOVE ACROSS LAKE SUPERIOR WED. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED THRU THU WITH THE STRONGEST WINDS TO AROUND 40KT OVER THE E HALF OF THE LAKE. WINDS WILL DIMINISH TO UNDER 20KT W TO E THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...JLB MARINE...- NONE -
AREA FORECAST DISCUSSION
NWS BISMARCK ND
909 AM CDT TUE OCT 27 2015 .UPDATE... ISSUED AT 849 AM CDT TUE OCT 27 2015 A LOW PRESSURE AREA ACROSS WESTERN SOUTH DAKOTA AT 830 AM CDT HAS A WARM FRONTAL BOUNDARY EXTENDING NORTHEAST ACROSS SOUTHEAST NORTH DAKOTA. AREA OF RAIN ACROSS NORTH CENTRAL TRAILED OFF TO A NARROW BAND OF SHOWERS BETWEEN THE MISSOURI AND JAMES RIVER VALLEYS NORTH OF THE WARM FRONT. LOW LEVEL WARM AIR WILL MOVE NORTH INTO SOUTHEAST NORTH DAKOTA TODAY. CURRENT FORECAST LOOKS OK. MAY HAVE TO RAISE MAX TEMPS SOUTHEAST...BETWEEN WISHEK AND OAKES..IN THE WARM SECTOR OF THE SYSTEM. UPDATE ISSUED AT 637 AM CDT TUE OCT 27 2015 OVERALL...THE FORECAST REMAINS ON TRACK AS RAIN SHOWERS ACROSS CENTRAL NORTH DAKOTA CONTINUE TO PROPAGATE NORTH-NORTHEAST IN ASSOCIATION WITH AN UPPER LEVEL JET STREAK THIS MORNING. ONGOING FORECAST BLENDED TO OBSERVED TRENDS AND A TIME LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 327 AM CDT TUE OCT 27 2015 CLOUDS AND CHANCES OF RAIN TODAY...TURNING COLDER TONIGHT WITH LIGHT RAIN OR FLURRIES POSSIBLE. CURRENTLY...AN UPPER LEVEL LOW PRESSURE SYSTEM EXTENDED FROM THE ROCKIES INTO THE WESTERN PLAINS...WITH EMBEDDED SHORTWAVES/LOWS WITHIN THE MAIN TROUGH CIRCULATING CYCLONICALLY THROUGH THE TROUGH. ONE OF THE CIRCULATION CENTERS WAS LOCATED OVER NORTHWESTERN NORTH DAKOTA/NORTHEASTERN MONTANA...WITH AN AREA OF LIGHT TO MODERATE RAIN EXTENDING FROM NORTHEASTERN MONTANA ACROSS NORTHERN NORTH DAKOTA. THIS AREA OF RAIN CONTINUED TO MOVE NORTHWARD. ANOTHER CIRCULATION CENTER WAS OVER SOUTH CENTRAL NORTH DAKOTA...AND ASSOCIATED WITH ANOTHER AREA OF RAIN FROM HETTINGER AND FORT YATES NORTHWARD TO MORTON AND BURLEIGH COUNTIES. AS THE CIRCULATION CENTERS LIFT NORTH/NORTHEASTWARD ACROSS THE REGION THE AREA OF RAIN SHOULD CONTINUE LIFTING NORTHWARD THROUGH THE MORNING HOURS. THUS THE RAIN SHOULD BE ENDING FROM SOUTH TO NORTH THROUGH THE MORNING HOURS. THEN THIS AFTERNOON THE UPPER LEVEL TROUGH AXIS ENTERS WESTERN NORTH DAKOTA AND ARRIVES IN CENTRAL NORTH DAKOTA BY EVENING. MEANWHILE AT THE SURFACE...A TROUGH OF LOW PRESSURE OVER THE FRONT RANGE EARLY THIS MORNING IS PROGGED TO MOVE EASTWARD IN ASSOCIATION WITH THE UPPER LEVEL TROUGH AXIS. BY THIS EVENING THE SURFACE TROUGH IS PROGGED TO BE IN THE DEVILS LAKE/JAMES RIVER BASINS. THIS WILL KEEP THE CHANCES OF RAIN IN THE FORECAST MAINLY OVER NORTHERN NORTH DAKOTA THIS AFTERNOON. WE WILL SEE YET ANOTHER - STRONGER - UPPER LEVEL SHORTWAVE DIVE SOUTHEAST OUT OF ALBERTA TODAY AND APPROACH NORTHWESTERN NORTH DAKOTA LATER THIS AFTERNOON AS THIS SHORTWAVE MERGES WITH THE AFOREMENTIONED UPPER LEVEL TROUGH. THIS WILL DEEPEN/INTENSIFY THE SYSTEM AS IT MOVES SOUTHEAST ACROSS NORTH DAKOTA TONIGHT AND WEDNESDAY. THIS WILL RESULT IN A BLAST OF COLDER AIR PUSHING INTO THE STATE BEHIND GUSTY NORTHWEST WINDS THAT ARE EXPECTED TO DEVELOP. AFTER TEMPERATURES IN THE UPPER 30S AND LOWER 40S THIS MORNING...AND HIGHS TODAY IN THE 45 TO 55 RANGE...THE COLD AIR INTRUSION SHOULD RESULT IN LOWS TUESDAY NIGHT FROM THE MID 20S IN THE WEST TO LOWER 30S IN THE JAMES RIVER VALLEY. CHANCES OF PRECIPITATION WILL REMAIN IN THE FORECAST TONIGHT...AND CHANCES OF RAIN WILL BECOME CHANCES OF SNOW FROM WEST TO EAST DURING THE EVENING HOURS. LIGHT PRECIP AMOUNTS WILL KEEP ANY SNOW FROM ACCUMULATING...EXCEPT PERHAPS SOME LIGHT ACCUMULATIONS IN THE TURTLE MOUNTAINS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 327 AM CDT TUE OCT 27 2015 A COOL AND WINDY WEDNESDAY HIGHLIGHTS THE EXTENDED FORECAST. GIVEN GOOD AGREEMENT AMONGST THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES...UTILIZED A BLEND FOR THE PERIOD. THE CURRENT SHORTWAVE ACROSS NORTHERN ALBERTA AND SASKATCHEWAN TUESDAY MORNING IS FORECAST TO PROPAGATE SOUTHEAST INTO THE EASTERN DAKOTAS WEDNESDAY MORNING AND DEEPEN. THE ASSOCIATED SURFACE COLD FRONT FROM THE SHORT TERM WILL ALREADY HAVE PROPAGATED THROUGH WESTERN AND CENTRAL NORTH DAKOTA...WITH A WINDY AND COOL POST FRONTAL DAY EXPECTED. 0.5 KM WINDS OF 35-40 KTS ARE FORECAST IN A TIGHT PRESSURE GRADIENT ON THE BACKSIDE OF CYCLOGENESIS ACROSS THE GREAT LAKES...SUPPORTING NEAR ADVISORY LEVEL GUSTS ACROSS MUCH OF THE AREA. HOWEVER...GIVEN THE MARGINAL VALUES...WILL NOT ISSUE ANY WIND HEADLINES AT THIS TIME. A FEW WRAP AROUND RAIN SHOWERS...POTENTIALLY MIXED WITH SNOW IN THE MORNING...ARE POSSIBLE EAST OF US HIGHWAY 83 WEDNESDAY. AFTER WEDNESDAY...A POTENTIAL WARM UP INTO THE 50S AND LOWER 60S IS FORECAST FOR THE WEEKEND AS THE UPPER LEVEL PATTERN IS EXPECTED TO SETTLE BACK TO NEAR ZONAL. HOWEVER...EARLY NEXT WEEK A LONGWAVE WESTERN CONUS TROUGH IS POSSIBLE...WHICH WOULD SIGNAL A POSSIBLE RETURN TO ACTIVE WEATHER ACROSS THE NORTHERN PLAINS MID TO LATE NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 637 AM CDT TUE OCT 27 2015 WIDESPREAD IFR/LIFR CONDITIONS IN STRATUS/FOG/LIGHT RAIN ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING LIFTING TO MVFR/IFR THIS AFTERNOON. STRATUS REMAINING THROUGH THE NIGHT FOR MUCH OF THE AREA. KBIS/KJMS WILL HAVE A WINDOW THIS MORNING OF VFR CONDITIONS AS DRIER AIR BRIEFLY MOVES INTO THESE TERMINALS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...JV LONG TERM...AYD AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT TUE OCT 27 2015 .UPDATE... ISSUED AT 637 AM CDT TUE OCT 27 2015 OVERALL...THE FORECAST REMAINS ON TRACK AS RAIN SHOWERS ACROSS CENTRAL NORTH DAKOTA CONTINUE TO PROPAGATE NORTH-NORTHEAST IN ASSOCIATION WITH AN UPPER LEVEL JET STREAK THIS MORNING. ONGOING FORECAST BLENDED TO OBSERVED TRENDS AND A TIME LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 327 AM CDT TUE OCT 27 2015 CLOUDS AND CHANCES OF RAIN TODAY...TURNING COLDER TONIGHT WITH LIGHT RAIN OR FLURRIES POSSIBLE. CURRENTLY...AN UPPER LEVEL LOW PRESSURE SYSTEM EXTENDED FROM THE ROCKIES INTO THE WESTERN PLAINS...WITH EMBEDDED SHORTWAVES/LOWS WITHIN THE MAIN TROUGH CIRCULATING CYCLONICALLY THROUGH THE TROUGH. ONE OF THE CIRCULATION CENTERS WAS LOCATED OVER NORTHWESTERN NORTH DAKOTA/NORTHEASTERN MONTANA...WITH AN AREA OF LIGHT TO MODERATE RAIN EXTENDING FROM NORTHEASTERN MONTANA ACROSS NORTHERN NORTH DAKOTA. THIS AREA OF RAIN CONTINUED TO MOVE NORTHWARD. ANOTHER CIRCULATION CENTER WAS OVER SOUTH CENTRAL NORTH DAKOTA...AND ASSOCIATED WITH ANOTHER AREA OF RAIN FROM HETTINGER AND FORT YATES NORTHWARD TO MORTON AND BURLEIGH COUNTIES. AS THE CIRCULATION CENTERS LIFT NORTH/NORTHEASTWARD ACROSS THE REGION THE AREA OF RAIN SHOULD CONTINUE LIFTING NORTHWARD THROUGH THE MORNING HOURS. THUS THE RAIN SHOULD BE ENDING FROM SOUTH TO NORTH THROUGH THE MORNING HOURS. THEN THIS AFTERNOON THE UPPER LEVEL TROUGH AXIS ENTERS WESTERN NORTH DAKOTA AND ARRIVES IN CENTRAL NORTH DAKOTA BY EVENING. MEANWHILE AT THE SURFACE...A TROUGH OF LOW PRESSURE OVER THE FRONT RANGE EARLY THIS MORNING IS PROGGED TO MOVE EASTWARD IN ASSOCIATION WITH THE UPPER LEVEL TROUGH AXIS. BY THIS EVENING THE SURFACE TROUGH IS PROGGED TO BE IN THE DEVILS LAKE/JAMES RIVER BASINS. THIS WILL KEEP THE CHANCES OF RAIN IN THE FORECAST MAINLY OVER NORTHERN NORTH DAKOTA THIS AFTERNOON. WE WILL SEE YET ANOTHER - STRONGER - UPPER LEVEL SHORTWAVE DIVE SOUTHEAST OUT OF ALBERTA TODAY AND APPROACH NORTHWESTERN NORTH DAKOTA LATER THIS AFTERNOON AS THIS SHORTWAVE MERGES WITH THE AFOREMENTIONED UPPER LEVEL TROUGH. THIS WILL DEEPEN/INTENSIFY THE SYSTEM AS IT MOVES SOUTHEAST ACROSS NORTH DAKOTA TONIGHT AND WEDNESDAY. THIS WILL RESULT IN A BLAST OF COLDER AIR PUSHING INTO THE STATE BEHIND GUSTY NORTHWEST WINDS THAT ARE EXPECTED TO DEVELOP. AFTER TEMPERATURES IN THE UPPER 30S AND LOWER 40S THIS MORNING...AND HIGHS TODAY IN THE 45 TO 55 RANGE...THE COLD AIR INTRUSION SHOULD RESULT IN LOWS TUESDAY NIGHT FROM THE MID 20S IN THE WEST TO LOWER 30S IN THE JAMES RIVER VALLEY. CHANCES OF PRECIPITATION WILL REMAIN IN THE FORECAST TONIGHT...AND CHANCES OF RAIN WILL BECOME CHANCES OF SNOW FROM WEST TO EAST DURING THE EVENING HOURS. LIGHT PRECIP AMOUNTS WILL KEEP ANY SNOW FROM ACCUMULATING...EXCEPT PERHAPS SOME LIGHT ACCUMULATIONS IN THE TURTLE MOUNTAINS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 327 AM CDT TUE OCT 27 2015 A COOL AND WINDY WEDNESDAY HIGHLIGHTS THE EXTENDED FORECAST. GIVEN GOOD AGREEMENT AMONGST THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES...UTILIZED A BLEND FOR THE PERIOD. THE CURRENT SHORTWAVE ACROSS NORTHERN ALBERTA AND SASKATCHEWAN TUESDAY MORNING IS FORECAST TO PROPAGATE SOUTHEAST INTO THE EASTERN DAKOTAS WEDNESDAY MORNING AND DEEPEN. THE ASSOCIATED SURFACE COLD FRONT FROM THE SHORT TERM WILL ALREADY HAVE PROPAGATED THROUGH WESTERN AND CENTRAL NORTH DAKOTA...WITH A WINDY AND COOL POST FRONTAL DAY EXPECTED. 0.5 KM WINDS OF 35-40 KTS ARE FORECAST IN A TIGHT PRESSURE GRADIENT ON THE BACKSIDE OF CYCLOGENESIS ACROSS THE GREAT LAKES...SUPPORTING NEAR ADVISORY LEVEL GUSTS ACROSS MUCH OF THE AREA. HOWEVER...GIVEN THE MARGINAL VALUES...WILL NOT ISSUE ANY WIND HEADLINES AT THIS TIME. A FEW WRAP AROUND RAIN SHOWERS...POTENTIALLY MIXED WITH SNOW IN THE MORNING...ARE POSSIBLE EAST OF US HIGHWAY 83 WEDNESDAY. AFTER WEDNESDAY...A POTENTIAL WARM UP INTO THE 50S AND LOWER 60S IS FORECAST FOR THE WEEKEND AS THE UPPER LEVEL PATTERN IS EXPECTED TO SETTLE BACK TO NEAR ZONAL. HOWEVER...EARLY NEXT WEEK A LONGWAVE WESTERN CONUS TROUGH IS POSSIBLE...WHICH WOULD SIGNAL A POSSIBLE RETURN TO ACTIVE WEATHER ACROSS THE NORTHERN PLAINS MID TO LATE NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 637 AM CDT TUE OCT 27 2015 WIDESPREAD IFR/LIFR CONDITIONS IN STRATUS/FOG/LIGHT RAIN ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING LIFTING TO MVFR/IFR THIS AFTERNOON. STRATUS REMAINING THROUGH THE NIGHT FOR MUCH OF THE AREA. KBIS/KJMS WILL HAVE A WINDOW THIS MORNING OF VFR CONDITIONS AS DRIER AIR BRIEFLY MOVES INTO THESE TERMINALS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...JV LONG TERM...AYD AVIATION...AYD
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1030 AM CDT TUE OCT 27 2015 .UPDATE... CURRENT REFLECTIVITY SHOWS LEADING SURGE OF PRECIPITATION MAKING ITS WAY THROUGH N IL PRESENTLY. THIS SURGE OF PRECIP IS ARRIVING SLIGHTLY LATER THAN PREVIOUS EXPECTED...SO REDUCED POPS UNTIL THE EARLY TO MID AFTERNOON ACROSS S WI. LATEST HRRR GUIDANCE SUPPORTS THIS THINKING. OTHERWISE...MID TO UPPER LEVEL CLOUD DECK OVER THE REGION WILL THICKEN THIS AFTERNOON INTO THE EVENING HOURS AS AREA OF LOW PRESSURE TRANSLATES FARTHER NORTH INTO THE REGION. RAIN CHANCES WILL INCREASE THIS AFTERNOON AND INTO THE EVENING...WITH THE BEST CHANCES BEING IN THE EVENING AND OVERNIGHT HOURS. EASTERLY WINDS WILL REMAIN GUSTY THIS AFTERNOON INTO THE EVENING. && .AVIATION/18Z TAFS/... VFR CIGS AND VSBYS WILL REDUCE TO MVFR THIS AFTERNOON AND IFR IN THE EVENING AS AN AREA OF LOW PRESSURE MAKES ITS WAY INTO THE REGION. A MOIST AIR MASS ASSOCIATED WITH THE LOW WILL PROVIDED ABUNDANT MOISTURE FOR MODERATE RAIN TO DEVELOP. THE BEST CHANCES WILL BE LATER THIS AFTERNOON...INTO THE EVENING AND OVERNIGHT. GUSTY EASTERLY WINDS IN THE LOWER TO MID 20 KT RANGE WILL DEVELOP THIS AFTERNOON AND LAST INTO THE EVENING HOURS. WIND-DRIVEN RAIN WILL AFFECT VSBYS LATER TONIGHT...LEADING TO THE REDUCTION TO MVFR AND IFR CONDITIONS. && .PREV DISCUSSION... /ISSUED 347 AM CDT TUE OCT 27 2015/ SHORT TERM... TODAY - CONFIDENCE...MEDIUM. PROTECTIVE MID-LEVEL RIDGING OVER SOUTHERN WI AND THE WESTERN GTLAKES MOVING OFF TO THE NORTHEAST...SUCCUMBING TO UPSTREAM PHASING OF NORTHERN AND SOUTHERN STREAM WAVES. THIS UPSTREAM TROF AMPLIFICATION WILL PULL LOW PRESSURE OVER THE SOUTHERN MS VALLEY REGION NORTHWARD TODAY AND TONIGHT. THIS NORTHWARD MOVING LOW PRESSURE SYSTEM HAS DEEPER COLUMN HUMIDITY ASSOCIATED WITH IT. PRECIPITABLE WATER IS EXPECTED TO MORE THAN DOUBLE IN THE NEXT 12-18 HOURS TO OVER 1 INCH. SFC DEWPOINTS IN THE LOWER 50S ARE NOW CREEPING NORTHWARD ACROSS IL AND THE CENTRAL MS VALLEY REGION. THIS SURGE OF MOISTURE WILL INITIALLY BE FIGHTING AGAINST A DRY EASTERLY AIR FEED ACROSS THE LOWER GTLAKES. HENCE THIS WILL SLOW THE DEVELOPMENT OF MEASUREABLE RAIN ACROSS SRN WI FOR A TIME TODAY INTO THIS EVENING ACROSS THE EASTERN CWA. NEVER THE LESS...WITH SURGE OF MOISTURE ALONG WARM CONVEYOR BELT THIS AFTERNOON...EXPECT AREAS OF LIGHT RAIN TO SPREAD INTO SOUTHWEST CWA IN THE EARLY AFTN...EVENTUALLY MAKING ITS WAY NORTH AND EAST THROUGH THE LATE AFTN INTO THE EARLY EVENING. LAYER Q-VECTOR CONVERGENCE INCREASES DURING THE AFTERNOON AND EARLY EVENING AS LOW LEVEL JET AND INCREASED LOW TO MID LEVEL CONVERGENCE INCREASE OVER THE WESTERN GTLAKES. TONIGHT - CONFIDENCE...HIGH. WIDESPREAD RAIN IS EXPECTED DURING THE EVENING AS SURGE OF MOISTURE TIED TO PASSING MID-LEVEL SHORT WAVE AND INCREASING LOW LEVEL CONVERGENCE PASS ACROSS SRN WI. QPF FROM THIS AFTN THRU TNGT SHOULD BE AROUND THREE QUARTER INCHES. MID-LEVEL DRYING WILL BEGIN TO WRAP AROUND THE DEEPENING LOW PRESSURE SYSTEM OVER THE TRI-STATE AREA LATE TONIGHT. THIS WILL LIKELY TRANSITION THE STEADY RAIN TO PERIODS OF LIGHT RAIN AND LIGHT SHOWERS. WEDNESDAY THROUGH THURSDAY... FORECAST CONFIDENCE MEDIUM. EXPECT LULLS IN THE PRECIP DURING THE DAY WED AS MID LEVELS BEGIN TO DRY OUT. LOW CLOUDS AND DRIZZLE ARE LIKELY FOR THE MORNING HOURS AS THE SURFACE LOW TRACKS OVERHEAD. HIGHS WED WILL BE LIMITED IN THE 50S WHICH WILL OCCUR DURING THE MORNING HOURS. THE CLOSED UPPER LOW WILL SLIDE SOUTHEAST THROUGH THE DAKOTAS AND MN ON WED. THIS WILL BRING THE COLDER AIR INTO SOUTHERN WI LATE WED AFTERNOON. THE STRONG COLD AIR ADVECTION WILL ALLOW FOR STEEP LOW LEVEL LAPSE RATES... A PERIOD OF ENHANCED SHOWER ACTIVITY AND VERY GUSTY WINDS. NW 850 MB WINDS WILL APPROACH 50 KNOTS OVER SOUTHERN WI IN THE WAKE OF THE UPPER LOW WED NIGHT. GUSTS TO 40 MPH SEEM LIKELY OVERNIGHT. SHOWERS COULD TAP INTO THE SNOW GROWTH ZONE LATER WED NIGHT INTO THU MORNING SO SNOW SHOWERS ARE POSSIBLE. THE GROUND WILL BE TOO WARM FOR ANY ACCUMULATION. BLUSTERY NORTHWEST WINDS WILL PERSIST THROUGH THE DAY THURSDAY... ALONG WITH A STRATOCUMULUS CLOUD DECK. SHOWERS SHOULD TAPER OFF BY EARLY AFTERNOON AS DRIER AIR WORKS INTO THE REGION. LONG TERM... FRIDAY THROUGH SUNDAY... FORECAST CONFIDENCE MEDIUM. TEMPERATURES SHOULD BOTTOM OUT AROUND FREEZING INLAND FROM LAKE MICHIGAN FRI MORNING WITH CLEARING SKIES AND DIMINISHING WINDS. A MID LEVEL TROUGH APPROACHING THE UPPER MIDWEST WILL DRAW SOUTHERLY WINDS AND MORE SEASONABLE TEMPERATURES BACK INTO THE AREA ON FRIDAY AND THE REST OF THE WEEKEND. MOISTURE WILL RETURN AS WELL... LEADING TO CHANCES FOR RAIN FRIDAY NIGHT THROUGH SATURDAY. MONDAY AND BEYOND... FORECAST CONFIDENCE LOW. MODELS ARE STRUGGLING WITH AN UPPER LOW OVER THE SOUTHWEST US... SO PRECIP CHANCES FOR EARLY NEXT WEEK REMAIN UNCERTAIN. AVIATION/12Z TAFS/... VFR CONDITIONS TODAY WILL YIELD TO RAPIDLY FALLING CIGS AND VSBYS FROM MID AFTN THRU THE EVENING AS WIDESPREAD RAIN OVERSPREADS TAF SITES. WITH MOIST ELY FLOW AND STRONG WINDS...EXPECT CIGS TO FALL TO IFR AND POSSIBLY BELOW ALTERNATE MINIMUMS DURING THE EVENING...WITH LITTLE RECOVERY EXPECTED THROUGH THE LATE NIGHT. BLUSTERY ELY WINDS WILL ACCOMPANY OVERNIGHT RAIN. SOME IMPROVEMENT IN CIGS LIKELY LATER WED AS STEADY PRECIP TURNS MORE SHOWERY. MARINE...NORTHWARD MOVING LOW PRESSURE IS EXPECTED TO UNDERGO RAPID DEEPENING OVER THE WESTERN GREAT LAKES ON WEDNESDAY AS IT TRACKS NORTHWARD FROM THE LAKE MICHIGAN VICINITY TO LAKE SUPERIOR. A TIGHT PRESSURE GRADIENT ON THE SOUTH SIDE OF THE LOW AND STRONG COLD ADVECTION OVER THE RELATIVELY WARMER LAKE MICHIGAN WATERS WILL ALLOW STRONG GUSTY WINDS TO AFFECT THE LAKE SURFACE FROM WED AFTN INTO THU. STRENGTH OF LOW LEVEL FLOW ASSOCIATED WITH LOW PRESSURE WILL CREATE FAVORABLE CONDITIONS FOR WIND GUSTS REACHING 35 KTS. HENCE WL UPGRADE ONGOING SMALL CRAFT ADVISORY TO GALE WATCH FOR THE PERIOD FROM 21Z/WED TO 21Z/THU. WILL ALSO PUSH UP START TIME OF ONGOING SMALL CRAFT ADVISORY SEVERAL HOURS TO 15Z. WILMETTE BUOY REPORTING 4-5FT WAVES AT 08Z WITH 19KT ONSHORE WIND GUSTS. EXPECT WIND GUSTS TO 20KTS TO DEVELOP BY MID- MORNING ACROSS THE NEARSHORE WATERS. THE LOW PRESSURE SYSTEM OVER THE SOUTHERN MS VALLEY REGION WILL MOVE TOWARD WI TODAY AND TONIGHT RESULTING IN THE INCREASING ELY SFC WINDS. A FEW GUSTS COULD GET CLOSE TO GALE CRITERIA TONIGHT BEFORE THE PRESSURE GRADIENT WEAKENS DUE TO THE PROXIMITY OF THE PASSING LOW PRESSURE SYSTEM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON FOR LMZ643>646. SMALL CRAFT ADVISORY UNTIL 4 PM CDT WEDNESDAY FOR LMZ643>646. && $$ UPDATE...JTS TODAY/TONIGHT AND AVIATION/MARINE...MBK WEDNESDAY THROUGH MONDAY...MRC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
651 AM CDT TUE OCT 27 2015 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY ISSUED AT 342 AM CDT TUE OCT 27 2015 FOCUS IN THE SHORT TERM WILL CONTINUE TO BE ON THE TIMING AND DURATION OF STRATIFORM RAIN SHIELD FORECAST TO EVOLVE OVER THE FORECAST AREA...AS NORTHERN AND SOUTHERN STREAM ENERGY CONGEAL OVER THE UPPER MIDWEST AND GREAT LAKES REGION TONIGHT AND WEDNESDAY. IN THE MEANTIME...WEAK MID-LEVEL FRONTOGENETIC FORCING IN CONCERT WITH SUBTLE SHORTWAVE IMPULSES AND SOMEWHAT DEEPER MOISTURE CONTINUES TO GENERATE A PESKY NARROW BAND OF VERY LIGHT RAIN OR SPRINKLES CURRENTLY EXTENDING FROM NORTHCENTRAL WISCONSIN TO NORTHERN MINNESOTA. RAP SEEMS TO HAVE CAPTURED THE BASIC EVOLUTION OF THIS VERY LIGHT PRECIPITATION BAND AND CARRIES IT NORTHWARD INTO UPPER MICHIGAN BY 14 OR 15Z THIS MORNING WHICH SEEMS REASONABLE BASED ON CURRENT TRENDS. NOT GOING TO INCLUDE MENTION OF ANY POPS THIS MORNING FOR THE FAR NORTH AS MEASURABLE AMOUNTS ARE DUBIOUS AT THIS POINT. OTHERWISE...FOR THE REMAINDER OF TODAY EXPECT LOTS OF MID-LEVEL CLOUDINESS WITHIN BROAD AREA OF WEAK ISENTROPIC LIFT. ACROSS NORTHERN WISCONSIN...EXPECT MORE IN THE WAY OF LOW CLOUDS AND SOME PATCHY FOG FOR AT LEAST A COUPLE MORE HOURS EARLY THIS MORNING. DESPITE LOTS OF CLOUDS...TEMPERATURES WILL REMAIN WELL ABOVE NORMAL FOR LATE OCTOBER WITH READINGS MAINLY IN THE 55 TO 60 DEGREE RANGE. THEN FOCUS SHIFTS TO THIS EVENING AND OVERNIGHT...AS SHORTWAVE ENERGY OVER THE CENTRAL PLAINS GRADUALLY CONGEALS WITH MORE POTENT SHORTWAVE DROPPING OUT OF CANADA. SOMEWHAT SURPRISINGLY...SEEMS TO BE FAIRLY DECENT CONSENSUS AMONG THE MODEL GUIDANCE ON THE OVERALL EVOLUTION OF THIS SYSTEM OVER THE NEXT 24 TO 36 HOURS AS PRIMARY UPPER-LOW DEEPENS OVER WESTCENTRAL MINNESOTA AND SURFACE CYCLOGENESIS RAPIDLY COMMENCES OVER THE UPPER MIDWEST DURING THE DAY ON WEDNESDAY. CONSENSUS OF MODEL GUIDANCE TAKES DEEPENING SURFACE LOW SITUATED NEAR DVN BY 06Z WEDNESDAY...NORTHEAST TO NEAR GRB BY 15Z WEDNESDAY. DURING THIS PERIOD...HUGE SLUG OF DEEP MOISTURE OVER THE SOUTHERN AND CENTRAL MISSISSIPPI WILL ALSO BE RAPIDLY DRAWN NORTHWARD INTO WISCONSIN WEDNESDAY EVENING AS 850 MB SOUTHERLY WINDS INCREASE TO 30 TO 40 KTS. LEADING EDGE OF PRIMARY PRECIPITATION SHIELD SHOULD BEGIN TO IMPACT OUR SOUTHERN TIER OF COUNTIES AROUND 00Z WEDNESDAY...THEN STEADILY SPREAD NORTHWARD OVERNIGHT. INCREASING PRESSURE GRADIENT ON THE NORTH SIDE OF THE DEEPENING SURFACE LOW WILL ALSO LEAD TO INCREASING SOUTHEASTERLY BOUNDARY LAYER WINDS TUESDAY NIGHT INTO EARLY WEDNESDAY. STRONGEST QG FORCING AND DEEP LAYER LIFT EXPECTED TO MOVE ACROSS THE FORECAST AREA ROUGHLY BETWEEN ABOUT 06Z AND 15Z WEDNESDAY...WHEN THE BULK OF THE RAINFALL WILL OCCUR. FORTUNATELY THIS SYSTEM WILL BE RATHER PROGRESSIVE WITH THE BULK OF THE PRECIPITATION MOVING NORTHEAST OF THE FORECAST AREA BY AROUND 00Z THURSDAY AS MID-LEVEL DRY INTRUSION AND STRONG SUBSIDENCE PUSH ACROSS THE SOUTHERN HALF OF WISCONSIN. RAINFALL AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE...WITH STORM TOTAL PRECIPIATION AMOUNTS APPROACHING THREE QUARTER TO PERHAPS AN INCH LOCALLY OVER THE SOUTHWEST PORTION OF THE FORECAST AREA. LOOKS LIKE THE ENTIRE FORECAST AREA SHOULD SEE A DECENT SOAKING RAIN. .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY ISSUED AT 342 AM CDT TUE OCT 27 2015 SIGNIFICANT STORM EXPECTED TO MOVE ACROSS THE REGION WEDNESDAY AND THEN SLOWLY MOVE AWAY FROM THE REGION WEDNESDAY NIGHT AND THURSDAY. SOME SIGNIFICANT DIFFERENCES NOTED IN HOW MUCH COLD AIR GETS WRAPPED INTO THE SYSTEM ACROSS THE NORTH WEDNESDAY NIGHT WHICH WOULD HAVE AN IMPACT ON PRECIPITATION TYPES AND AMOUNT OF SNOW THE FAR NORTH WOULD RECEIVE. GFS IS SLOWER WITH COLDER AIR MOVING INTO THE NORTH...MAINLY LATE EVENING AND OVERNIGHT. THE ECMWF ON THE OTHER HAND WOULD SUGGEST SNOW WOULD START DURING THE EARLY EVENING HOURS AND CONTINUE INTO THURSDAY MORNING. 850MB WINDS WILL BECOME VERY FAVORABLE AT 340 DEGREES FOR LAKE ENHANCEMENT SNOW SHOWERS ACROSS THE NORTH IF THE COLDER AIR MATERIALIZES. LATER SHIFTS WILL NEED TO MONITOR THIS AND MAY NEED ADJUST SNOWFALL TOTALS ACCORDINGLY ONCE MODELS CONVERGE ] ON THE TIMING OF THE COLD AIR. FLURRIES MAY BE SEEN AS FAR SOUTH AS WISCONSIN RAPIDS TO THE FOX VALLEY LATE WEDNESDAY NIGHT BUT NO ACCUMULATION IS EXPECTED IN THIS REGION. GUSTY WESTERLY WINDS OF 30 TO 40 MPH CAN BE EXPECTED WEDNESDAY NIGHT INTO THURSDAY BEHIND THE DEPARTING SYSTEM. INCREASED RAIN CHANCES ACROSS THE AREA DUE TO COLD CYCLONIC FLOW AND WEAK DISTURBANCE MOVING ACROSS THE REGION. DO EXPECT INSTABILITY RAIN SHOWERS...WITH SNOW ACROSS THE NORTH DURING THE MORNING. THE SHOWERS WILL GRADUALLY DIMINISH DURING THE LATE AFTERNOON HOURS. THE NEXT CHANCE OF RAIN WILL OCCUR FRIDAY NIGHT AND SATURDAY AS A COLD FRONT MOVES ACROSS THE STATE. BEYOND THIS PERIOD...NO REAL SIGNIFICANT CHANCES FOR RAIN. MAIN STORY WILL BE THE ABOVE NORMAL TEMPERATURES EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 649 AM CDT TUE OCT 27 2015 OTHER THAN SOME SCT IFR CIGS OVER NORTHERN WISCONSIN UNTIL ABOUT 14Z...MAINLY VFR CONDITIONS WILL PREVAIL THROUGH EARLY THIS EVENING. A COMPLEX WEATHER SYSTEM WILL THEN RAPIDLY CONGEAL OVER THE UPPER MIDWEST OVERNIGHT TONIGHT...WITH A LARGE AREA OF STRATIFORM RAINFALL FORECAST TO SPREAD FROM SOUTH TO NORTH ACROSS THE FORECAST AREA LATE THIS EVENING. VFR CONDITIONS WILL GRADUALLY GIVE WAY TO MVFR CIGS AND VSBYS AS RAINFALL COMMENCES...FIRST AT WESTERN TAFS SITES INCLUDING AUW/CWA AFTER ABOUT 03Z...THEN EASTCENTRAL TAF SITES INCLUDING ATW/GRB AFTER ABOUT 06Z. MVFR CONDITIONS WILL LIKELY NOT REACH THE NORTHERN PORTION OF THE FORECAST AREA UNTIL AFTER 09Z. CONDITIONS WILL LIKELY CONTINUE TO DETERIORATE TO IFR OVER AT LEAST THE SOUTHERN THIRD OF THE FORECAST AREA AFTER 09Z WEDNESDAY IN LIGHT TO MODERATE RAIN. BRISK SOUTHEAST WINDS WILL ALSO DEVELOP LATER THIS EVENING...WITH OCCASIONAL GUSTS TO 20 KTS...AS A DEEPENING LOW PRESSURE SYSTEM APPROACHES FROM EASTERN IOWA. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ESB LONG TERM......ECKBERG AVIATION.......ESB
AREA FORECAST DISCUSSION
NWS LINCOLN IL
ISSUED BY NATIONAL WEATHER SERVICE CHICAGO IL 147 PM CDT TUE OCT 27 2015 .UPDATE... ISSUED AT 1059 AM CDT TUE OCT 27 2015 LOCAL RADAR IMAGERY AND OBS INDICATE WIDELY SCT LIGHT SHOWERS ONGOING ACROSS THE AREA. HOWEVER...MORE WIDESPREAD RAIN IS EXPECTED ACROSS THE REGION THIS AFTERNOON AND EVENING AS OUR NEXT SURGE OF MOISTURE...ASSOCIATED WITH THE NORTHWARD MOVING GULF LOW...SHIFTS NORTH-NORTHEASTWARD OVER EASTERN ILLINOIS INTO Indiana. THIS SHOULD RESULT IN A DECENT RAINFALL EVENT...WITH THE HIGHEST AMOUNTS LIKELY ACROSS MY EAST CENTRAL ILLINOIS COUNTIES...WHERE RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE ANTICIPATED. FARTHER WEST...AMOUNTS UP TO AN INCH ARE POSSIBLE. IT APPEARS THE THREAT OF THUNDER WILL BE VERY LOW TONIGHT...BUT NOT ZERO. THE BEST CHANCES OF EMBEDDED THUNDERSTORMS LOOKS TO BE ACROSS MY SOUTHERN AND EASTERN COUNTIES LATE TONIGHT...POSSIBLY INTO VERY EARLY Wednesday MORNING...JUST AHEAD OF AN EASTWARD ADVANCING COLD FRONTAL BOUNDARY. && .SHORT TERM...(Today) ISSUED AT 324 AM CDT TUE OCT 27 2015 08z/3am surface analysis shows ridge of high pressure extending from New England southwestward to the Central Plains...while a 1005mb low continues to spin over Louisiana. Showers from the Gulf Coast low have been slowly spreading northward over the past several hours, but have been encountering a very dry mid/low-level airmass beneath the surface ridge as evidenced by the 00z KILX upper air sounding and current surface dewpoints in the middle to upper 30s across the northern half of the CWA. This dry air has been impeding the northward progress of the precip...with 08z/3am radar imagery and surface obs indicating very light showers/sprinkles confined to locations along and south of a Litchfield to Paris line. HRRR has a decent handle on the current situation and suggests light rain will likely not make it north of the Peoria area until after sunrise. Have therefore cut back PoPs early this morning, especially across the far N/NW CWA where dry air will delay precip onset. Once the airmass moistens sufficiently and an upper-level trough approaching from the west provides increasing synoptic lift, rain will become widespread across the entire area by mid to late morning through the afternoon. Thanks to the rain and a brisk easterly wind of 10 to 15mph, high temperatures today will be considerably cooler than yesterday with readings remaining in the 50s in most locations. .LONG TERM...(Friday through Tuesday) ISSUED AT 145 PM CDT TUE OCT 27 2015 FRIDAY WILL BE A QUIET BUT COOL DAY AS TRANSITORY RIDGING BETWEEN THE DEPARTING TROUGH AND A DEEPENING UPPER LOW OVER THE SOUTHWEST. SURFACE HIGH PRESSURE OVER THE AREA WILL BE SHIFTING EAST...ALLOWING FOR SOME RECOVERIES FROM HIGHS ON THURSDAY. AFTER MOSTLY SUNNY SKIES TO START, CLOUD COVER INCREASES AS THE UPPER LOW TRANSLATES EAST. MODEST WARM AIR ADVECTION FRIDAY NIGHT INTO SATURDAY. MODELS DO NOT PAINT A CLEAR PICTURE AS TO HOW QUICKLY THE UPPER LOW WILL MOVE THROUGH THE REGION, AS THERE IS THE POTENTIAL FOR IT TO GET CUT OFF FROM THE NORTHERN STREAM FLOW. TO WHAT DEGREE THIS OCCURS WILL DIRECTLY TRANSLATE TO WHETHER THE WEEKEND WILL REMAIN OCCASIONALLY RAINY, OR IF A BREAK OCCURS ON SUNDAY BEFORE THE UPPER LOW MOVES THROUGH BY MONDAY. THEREFORE...WILL MAINTAIN THE HIGHEST RAIN CHANCES ON HALLOWEEN, FOLLOWED BY SOME CHANCE POPS SUNDAY/MONDAY WITH LOWER CONFIDENCE IN THESE TIME FRAMES. TEMPERATURES CONTINUE TO CLIMB BACK INTO THE 60S WITH PARTLY SUNNY/MOSTLY CLOUDY CONDITIONS. ONCE THE LOW SLIPS NORTHEAST, ANOMALOUSLY STRONG HIGH PRESSURE OVER THE SOUTHEAST AND ADJACENT ATLANTIC COAST WILL EXPAND NORTHWESTWARD AS ANOTHER DEEP UPPER LOW DIGS INTO THE SOUTHWESTERN UNITED STATES. THIS HIGHLY AMPLIFIED PATTERN SETS UP A WARM SOUTHWEST FLOW...RESULTING IN HIGH TEMPERATURES INTO THE 70S BY TUESDAY. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 1228 PM CDT TUE OCT 27 2015 WIDESPREAD LIFR CONDITIONS WILL REMAIN IN PLACE ACROSS THE AREA THROUGH THE AFTERNOON AND EVENING AS RAIN BANDS CONTINUE TO ROTATE NORTHWARD. UPSTREAM OBSERVATIONS SUGGEST SOME LIFTING CIGS ARE POSSIBLE, BUT WARM ADVECTION ABOVE THE COOL MOIST BOUNDARY LAYER SUGGESTS HOLDING THE LIFR CONDITIONS. VISIBILITY WILL VARY FROM 1-3 MILES AS THE RAIN BANDS MOVE THROUGH. THE PRESSURE GRADIENT SUPPORTS WINDS IN THE MID TEENS, WITH OCCASIONAL GUSTS POSSIBLE THOUGH WITH THE RAIN THE WIND GUSTS HAVE BEEN TEMPERED. ISOLATED TSRA DOES REMAIN POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY, BUT PROBABILITY STILL TOO LOW FOR MENTION IN TAFS AT THIS TIME. WINDS WILL VEER TO S-SW AFTER 09Z-12Z AND WEAKEN SOME AS THE DEEPENING LOW PRESSURE SYSTEM MOVES OVERHEAD. WINDS THEN TURN WSW BY MID MORNING WEDNESDAY AND QUICKLY INCREASE AS THE LOW LIFTS NORTHEAST. THERE WILL BE SOME SHOWERS BEHIND THE LOW, BUT THE BETTER CHANCES LOOK TO ARRIVE LATER IN THE DAY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KB SHORT TERM...Barnes LONG TERM...KMD AVIATION...KMD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
602 PM EDT TUE OCT 27 2015 .SYNOPSIS... STRONG LOW PRESSURE WILL BRING RAIN THROUGH WEDNESDAY NIGHT. SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE REST OF THE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... WITH 6PM UPDATE...HAVE SLIGHTLY REDUCED POPS OVER THE NEXT 2-3 HOURS WITH MOST RADAR ECHOES NOT EXPECTED TO MAKE IT TO THE GROUND...BUT THEN INCREASED POPS THROUGH MIDNIGHT TO ACCOUNT FOR SOME BRIEF BANDING OF RAINFALL SHOWN IN MODEL FORECASTS. NO CHANGES HAVE BEEN MADE TO WIND HEADLINES AT THIS POINT...BUT WILL CONTINUE TO MONITOR POSSIBILITY THAT THE WIND ADVISORY MAY NEED TO BE FURTHER EXPANDED IN COVERAGE. THAT SCENARIO WAS EXPLAINED WELL IN THE PREVIOUS DISCUSSION...WHICH FOLLOWS BELOW. MOISTURE WILL CONTINUE TO INCREASE FROM THE SOUTH AHEAD OF THE REMNANTS OF PATRICIA. A RELATIVELY LONG PERIOD OF WET CONDITIONS WILL BE LIKELY OVER THE NEXT COUPLE OF DAYS AS THE MOISTURE FROM THE REMNANTS GET ABSORBED BY A VERY DEEP CLOSED UPPER LOW THAT WILL MOVE FROM THE GREAT LAKES THROUGH THE NORTHEAST THIS WEEK. DEEP SOUTHEASTERLY FLOW WILL INCREASE GOING INTO THE EVENING AS MOISTURE INCREASES. MULTI-MODEL CONSENSUS VALUES SUGGEST THE LOW LEVEL JET MAXIMA MAY WELL APPROACH 60-70 KTS FROM THE SOUTHEAST OVERNIGHT TONIGHT INTO WEDNESDAY MORNING. ADDITIONALLY...MODEL SOUNDINGS FAVOR INVERSION HEIGHTS SLIGHTLY ABOVE THE RIDGETOPS WITH SOUTHEASTERLY FLOW BEING PERPENDICULAR TO THE RIDGELINES. THIS COMBINED WITH FAIRLY UNSTABLE CONDITIONS BELOW THE INVERSION HEIGHTS...AS WELL AS PRECIPITATION DRAG WILL LIKELY MIX DOWN A FAIR AMOUNT OF WIND GUSTS. EVEN BELOW THE INVERSION LEVEL...NAM CONUS NEST PLOTS AND HRRR VALUES SUGGEST 45-55 KTS OF WIND GUST POTENTIAL IN CHESTNUT/LAUREL RIDGES AS WELL AS DOWNSLOPE MOUNTAIN WAVE WIND GUST POTENTIAL TO THE WEST OF THE RIDGES. DUE TO THE ORIENTATION OF THE TOPOGRAPHY RELATIVE TO THE FLOW...THIS FAVORS WIND GUST POTENTIAL PRIMARILY IN FAYETTE AND WESTMORELAND COUNTIES...AS WELL AS FAR SOUTHEASTERN INDIANA COUNTY. THE POTENTIAL IS A BIT LESS IN WEST VIRGINIA AND MARYLAND. THAT SAID...WITH GUSTS TO 50 MPH IN THE FORECAST...A WIND ADVISORY HAS BEEN ISSUED FOR WESTMORELAND AND FAYETTE COUNTIES. AS FLOW TURNS MORE SOUTHERLY ON WEDNESDAY IN ADVANCE OF THE APPROACHING WAVE...MOUNTAIN WAVE GUST POTENTIAL DECREASES SUBSTANTIALLY AS THE FLOW DIRECTION CHANGES AND THE LOW LEVEL JET LIFTS NORTHWARD. HOWEVER...AHEAD OF THE INCOMING FRONTAL BOUNDARY...DEEPER STEEP LAPSE RATES MOVE IN FROM THE WEST. THIS WILL ALLOW FOR THE RAIN SHADOW TO THE WEST OF THE RIDGES TO BE ERADICATED AS DEEPER LIFT ASSOCIATED WITH THE INCOMING JET STREAK AND DIFFERENTIAL PVA COUPLED WITH SKINNY CAPE ALONG THE FRONT MAY ALLOW FOR SOME THUNDERSTORM DEVELOPMENT. SHOULD A DECENT LINE FORM ALONG THE FRONT...GIVEN THE MOMENTUM IN THE COLUMN...A SEVERE WIND GUST OR TWO WILL BE POSSIBLE BY LATE AFTERNOON AND EVENING. SPC HAS OUTLINED THIS POSSIBILITY WITH A MARGINAL RISK...AND GIVEN THE LACK OF INSTABILITY...THIS SEEMS A PRAGMATIC APPROACH. A SLIGHT CHANCE OF THUNDERSTORMS WAS INCLUDED IN THE FORECAST...HOWEVER THE CHANCES OF SEVERE WEATHER DO NOT LOOK OVERLY IMPRESSIVE AT THIS TIME. IN ADVANCE OF THE SYSTEM OVERNIGHT...TEMPERATURES MAY WELL RISE DUE TO INCREASING MIXING...AND CONTINUE TO WARM ON WEDNESDAY MORNING AHEAD OF THE COLD FRONT. A FEW SPOTS MAY WELL TOUCH 70F BEFORE THE FRONT CROSSES AS THE UPPER LOW DROPS OVERHEAD LATER IN THE WEEK. FRIES && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... A SECONDARY COLD FRONT WILL CROSS EARLY THURSDAY MORNING... NECESSITATING THE INCLUSION OF CHANCE POPS UNTIL ITS EXIT. MORE IMPORTANTLY...PRESSURE RISES IMMEDIATELY BEHIND THE FRONT WILL BE RATHER SIGNIFICANT...WHICH LEADS TO CONCERN FOR STRONG WIND GUSTS THROUGH THE AFTERNOON. BUFKIT SOUNDINGS CONTINUE TO SHOW THIS DEEP MIXING LAYER WITH WIND AT THE TOP OF THE INVERSION APPROACHING 40-45KTS. WITH SOME UNCERTAINTY IN HOW MUCH OF THIS WIND WILL TRANSLATE TO THE SURFACE...HAVE OPTED TO MENTION THE THREAT IN THE HWO. ONCE THE SHOWERS END THURSDAY MORNING...EXPECT A DRY REMAINDER OF THE DAY...WITH DECREASING CLOUD COVER. THE UPPER TROUGH WILL FINALLY PIVOT TO THE EAST THURSDAY NIGHT...RETURNING THE REGION TO COLD NORTHWEST FLOW. CHANCE POPS WERE MAINTAINED OVERNIGHT THURSDAY WITH SOME COLD ADVECTION LAKE ENHANCED SHOWERS POSSIBLE. OTHERWISE...TEMPERATURES LOOK TO STAY BELOW SEASONAL AVERAGES BOTH THURSDAY AND FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A PROGRESSIVE FLOW PATTERN SHOULD RESULT IN A VARIABLE LONG TERM PERIOD WITH SHORTWAVE RIDGING FORECAST TO PROVIDE A DRY START TO THE WEEKEND...BUT ANOTHER TROUGH MOVING OUT OF THE MIDWEST IS TIMED TO DETERIORATE CONDITIONS WITH RAIN BY SUNDAY. SHORTWAVE RIDGING WOULD AGAIN DRY THE PROGNOSIS EARLY IN THE NEW WORK-WEEK. THE LONG TERM FORECAST WAS CONSTRUCTED USING A BLEND OF WPC AND GFSMOS GUIDANCE AND GENERALLY FEATURES CLIMO POPS AND TEMPS AT...OR A FEW DEGREES ABOVE THE AVERAGES. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS SHOULD CONTINUE AT MOST OF THE TAF LOCATIONS UNTIL AFTER SUNSET AS THE LOW AND MID LEVELS FINALLY SATURATE. MANY OF THE RETURNS CURRENTLY ON THE RADAR CONTINUE TO DISSIPATE AS THEY MOVE NORTHWARD INTO DRIER AIR. SO...THE TIMING OF THE ONSET OF PRECIPITATION AND RESTRICTIONS WAS PUSHED BACK A BIT ACROSS ALL TERMINALS. EXPECT A GRADUAL DETERIORATION OVERNIGHT WITH RESTRICTIONS LIKELY TO CONTINUE THROUGH MOST OF WEDNESDAY. IN ADDITION TO CIG AND SOME VSBY RESTRICTIONS...GUSTY ESE WIND WILL BE POSSIBLE TOWARD WEDNESDAY MORNING...ESPECIALLY AT THE TERMINALS CLOSEST TO THE RIDGES. HAVE OPTED TO CARRY GUSTS VERSUS LLWS THOUGH THE CONCERN IS THERE FURTHER WEST. OUTLOOK...WEDNESDAY THROUGH SUNDAY/... RESTRICTIONS ARE LIKELY THROUGH THURSDAY UNTIL A STRONG COLD FRONT CROSSES THE REGION. STRONG WIND GUSTS OR LOW LEVEL WIND SHEAR WILL ALSO BE POSSIBLE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...WIND ADVISORY FROM 2 AM TO 11 AM EDT WEDNESDAY FOR PAZ073>076. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
341 PM EDT TUE OCT 27 2015 .SYNOPSIS... STRONG LOW PRESSURE WILL BRING RAIN THROUGH WEDNESDAY NIGHT. SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE REST OF THE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... MOISTURE WILL CONTINUE TO INCREASE FROM THE SOUTH AHEAD OF THE REMNANTS OF PATRICIA. A RELATIVELY LONG PERIOD OF WET CONDITIONS WILL BE LIKELY OVER THE NEXT COUPLE OF DAY AS THE MOISTURE FROM THE REMNANTS GET ABSORBED BY A VERY DEEP CLOSED UPPER LOW THAT WILL MOVE FROM THE GREAT LAKES THROUGH THE NORTHEAST THIS WEEK. DEEP SOUTHEASTERLY FLOW WILL INCREASE GOING INTO THE EVENING AS MOISTURE INCREASES. MULTI-MODEL CONSENSUS VALUES SUGGEST THE LOW LEVEL JET MAXIMA MAY WELL APPROACH 60-70 KTS FROM THE SOUTHEAST OVERNIGHT TONIGHT INTO WEDNESDAY MORNING. ADDITIONALLY...MODEL SOUNDINGS FAVOR INVERSION HEIGHTS SLIGHTLY ABOVE THE RIDGETOPS WITH SOUTHEASTERLY FLOW BEING PERPENDICULAR TO THE RIDGELINES. THIS COMBINED WITH FAIRLY UNSTABLE CONDITIONS BELOW THE INVERSION HEIGHTS...AS WELL AS PRECIPITATION DRAG WILL LIKELY MIX DOWN A FAIR AMOUNT OF WIND GUSTS. EVEN BELOW THE INVERSION LEVEL...NAM CONUS NEST PLOTS AND HRRR VALUES SUGGEST 45-55 KTS OF WIND GUST POTENTIAL IN CHESTNUT/LAUREL RIDGES AS WELL AS DOWNSLOPE MOUNTAIN WAVE WIND GUST POTENTIAL TO THE WEST OF THE RIDGES. DUE TO THE ORIENTATION OF THE TOPOGRAPHY RELATIVE TO THE FLOW...THIS FAVORS WIND GUST POTENTIAL PRIMARILY IN FAYETTE AND WESTMORELAND COUNTIES...AS WELL AS FAR SOUTHEASTERN INDIANA COUNTY. THE POTENTIAL IS A BIT LESS IN WEST VIRGINIA AND MARYLAND. THAT SAID...WITH GUSTS TO 50 MPH IN THE FORECAST...A WIND ADVISORY HAS BEEN ISSUED FOR WESTMORELAND AND FAYETTE COUNTIES. AS FLOW TURNS MORE SOUTHERLY ON WEDNESDAY IN ADVANCE OF THE APPROACHING WAVE...MOUNTAIN WAVE GUST POTENTIAL DECREASES SUBSTANTIALLY AS THE FLOW DIRECTION CHANGES AND THE LOW LEVEL JET LIFTS NORTHWARD. HOWEVER...AHEAD OF THE INCOMING FRONTAL BOUNDARY...DEEPER STEEP LAPSE RATES MOVE IN FROM THE WEST. THIS WILL ALLOW FOR THE RAIN SHADOW TO THE WEST OF THE RIDGES TO BE ERADICATED AS DEEPER LIFT ASSOCIATED WITH THE INCOMING JET STREAK AND DIFFERENTIAL PVA COUPLED WITH SKINNY CAPE ALONG THE FRONT MAY ALLOW FOR SOME THUNDERSTORM DEVELOPMENT. SHOULD A DECENT LINE FORM ALONG THE FRONT...GIVEN THE MOMENTUM IN THE COLUMN...A SEVERE WIND GUST OR TWO WILL BE POSSIBLE BY LATE AFTERNOON AND EVENING. SPC HAS OUTLINED THIS POSSIBILITY WITH A MARGINAL RISK...AND GIVEN THE LACK OF INSTABILITY...THIS SEEMS A PRAGMATIC APPROACH. A SLIGHT CHANCE OF THUNDERSTORMS WAS INCLUDED IN THE FORECAST...HOWEVER THE CHANCES OF SEVERE WEATHER DO NOT LOOK OVERLY IMPRESSIVE AT THIS TIME. IN ADVANCE OF THE SYSTEM OVERNIGHT...TEMPERATURES MAY WELL RISE DUE TO INCREASING MIXING...AND CONTINUE TO WARM ON WEDNESDAY MORNING AHEAD OF THE COLD FRONT. A FEW SPOTS MAY WELL TOUCH 70F BEFORE THE FRONT CROSSES AS THE UPPER LOW DROPS OVERHEAD LATER IN THE WEEK. FRIES && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... A SECONDARY COLD FRONT WILL CROSS EARLY THURSDAY MORNING... NECESSITATING THE INCLUSION OF CHANCE POPS UNTIL ITS EXIT. MORE IMPORTANTLY...PRESSURE RISES IMMEDIATELY BEHIND THE FRONT WILL BE RATHER SIGNIFICANT...WHICH LEADS TO CONCERN FOR STRONG WIND GUSTS THROUGH THE AFTERNOON. BUFKIT SOUNDINGS CONTINUE TO SHOW THIS DEEP MIXING LAYER WITH WIND AT THE TOP OF THE INVERSION APPROACHING 40-45KTS. WITH SOME UNCERTAINTY IN HOW MUCH OF THIS WIND WILL TRANSLATE TO THE SURFACE...HAVE OPTED TO MENTION THE THREAT IN THE HWO. ONCE THE SHOWERS END THURSDAY MORNING...EXPECT A DRY REMAINDER OF THE DAY...WITH DECREASING CLOUD COVER. THE UPPER TROUGH WILL FINALLY PIVOT TO THE EAST THURSDAY NIGHT...RETURNING THE REGION TO COLD NORTHWEST FLOW. CHANCE POPS WERE MAINTAINED OVERNIGHT THURSDAY WITH SOME COLD ADVECTION LAKE ENHANCED SHOWERS POSSIBLE. OTHERWISE...TEMPERATURES LOOK TO STAY BELOW SEASONAL AVERAGES BOTH THURSDAY AND FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... A PROGRESSIVE FLOW PATTERN SHOULD RESULT IN A VARIABLE LONG TERM PERIOD WITH SHORTWAVE RIDGING FORECAST TO PROVIDE A DRY START TO THE WEEKEND...BUT ANOTHER TROUGH MOVING OUT OF THE MIDWEST IS TIMED TO DETERIORATE CONDITIONS WITH RAIN BY SUNDAY. SHORTWAVE RIDGING WOULD AGAIN DRY THE PROGNOSIS EARLY IN THE NEW WORK-WEEK. THE LONG TERM FORECAST WAS CONSTRUCTED USING A BLEND OF WPC AND GFSMOS GUIDANCE AND GENERALLY FEATURES CLIMO POPS AND TEMPS AT...OR A FEW DEGREES ABOVE THE AVERAGES. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS SHOULD CONTINUE AT MOST OF THE TAF LOCATIONS UNTIL AFTER SUNSET AS THE LOW AND MID LEVELS FINALLY SATURATE. MANY OF THE RETURNS CURRENTLY ON THE RADAR CONTINUE TO DISSIPATE AS THEY MOVE NORTHWARD INTO DRIER AIR. SO...THE TIMING OF THE ONSET OF PRECIPITATION AND RESTRICTIONS WAS PUSHED BACK A BIT ACROSS ALL TERMINALS. EXPECT A GRADUAL DETERIORATION OVERNIGHT WITH RESTRICTIONS LIKELY TO CONTINUE THROUGH MOST OF WEDNESDAY. IN ADDITION TO CIG AND SOME VSBY RESTRICTIONS...GUSTY ESE WIND WILL BE POSSIBLE TOWARD WEDNESDAY MORNING...ESPECIALLY AT THE TERMINALS CLOSEST TO THE RIDGES. HAVE OPTED TO CARRY GUSTS VERSUS LLWS THOUGH THE CONCERN IS THERE FURTHER WEST. OUTLOOK...WEDNESDAY THROUGH SATURDAY/... RESTRICTIONS ARE LIKELY THROUGH THURSDAY UNTIL A STRONG COLD FRONT CROSSES THE REGION. STRONG WIND GUSTS OR LOW LEVEL WIND SHEAR WILL ALSO BE POSSIBLE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...WIND ADVISORY FROM 2 AM TO 11 AM EDT WEDNESDAY FOR PAZ073>076. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
358 PM EDT TUE OCT 27 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 352 PM EDT TUE OCT 27 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL TROUGH DEVELOPING FROM SASK/MANITOBA INTO THE WRN AND SCNTRL PLAINS WITH SEVERAL EMBEDDED SHORTWAVES. DOWNSTREAM...A RIDGE HAS BUILT INTO THE GREAT LAKES AND OHIO VALLEY. AT THE SFC...SE FLOW PREVAILED ACROSS THE UPPER GREAT LAKES BTWN HIGH PRES OVER NRN ONTARIO/WRN QUEBEC AND A TROUGH OVER THE WRN/SCNTRL PLAINS WHICH LED TO SOME UPSLOPE STRATUS/FOG AT KSAW AND KCMX EARLIER THIS MORNING. OTHERWISE...VIS SATELLITE LOOP SHOWED MID CLOUDS SPREADING ACROSS INTO WRN AND CENTRAL UPPER MI WITH PARTLY SUNNY SKIES OVER ERN UPR MI. TONIGHT AND WEDNESDAY...THE MODELS WERE IN GOOD AGREEMENT WITH A SHORTWAVE OVER THE SRN PLAINS LIFTING TOWARD THROUGH THE MID MS VALLEY AS A STRONGER SHRTWV OVER SRN SASK DROPS INTO SRN MANITOBA AND NORTH DAKOTA. A DEEPENING SFC LOW WILL ALSO LIFT TO SE WI BY 12Z WED. INCREASING SSE 800-700 MB FLOW OF 35-50 KNOTS AHEAD OF THE LOW WILL DRAW ABUNDANT MOISTURE TOWARD UPPER MI (PWAT TO AROUND 1.0 INCH) AND THIS IN COMBINATION WITH DEEP-LAYER Q-VECTOR CONV WILL ALLOW RAIN TO SPREAD ACROSS THE CWA LATE TONIGHT INTO WED MORNING. PHASING OF NRN AND SRN STREAM SHORTWAVES WILL ALLOW LONGWAVE TROUGH TO DEEPEN OVER THE CENTRAL CONUS ON WED. IN TURN...AS MID-UPPER LEVEL TROUGH DEEPENS...SFC LOW OF 995-1000MB OVER SRN WI WED MORNING WILL DEEPEN NEAR 985 MB OVER ERN LAKE SUPERIOR LATE WED. DIMINISHING ISENTROPIC ASCENT IN THE MID-LATE AFTERNOON AS SFC-850 MB LOW MOVES OVERHEAD AND Q-VECTOR DIVERGENCE SPREADS IN FM THE S-SE IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE SHOULD ALLOW RAIN TO GRADUALLY DIMINISH FROM THE SOUTH LATE AFTERNOON TOWARD EVENING. AS RAIN DIMINISHES FROM SOUTH LATE MORNING INTO AFTERNOON STRATUS WILL LOWER AND FOG MAY FORM ESPECIALLY FOR AREAS FAVORED BY UPSLOPE E-SE FLOW AS DEWPOINTS RISE INTO UPPER 40S/LOWER 50S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 357 PM EDT TUE OCT 27 2015 THE DEEPENING SFC LOW WILL LIKELY BE SITUATED OVER LAKE SUPERIOR AND N UPPER MI AT 00Z THURSDAY...WITH THE 500MB LOW SET UP OVER S MN. LOOKS LIKE PRECIP WILL MAINLY STAY AS RAIN...BUT THERE WILL STILL BE A SMALL CHANCE OF SNOW SHOWERS MIXING IN OVER THE INTERIOR W HALF OF UPPER MI OVERNIGHT. THE WARMER TREND OF 850MB TEMPS CONTINUES...STARTING OUT AROUND 0C OVER THE FAR W AT 00Z THURSDAY AND BOTTOMING OUT BY 12Z THURSDAY IN THE -1 TO -4C RANGE WITH SFC TEMPS NEAR OR STILL ABOVE FREEZING. COOLER AIR WITH 850MB TEMPS OF - 3 TO -5C SLIDE IN LATE THURSDAY AFTERNOON INTO THURSDAY NIGHT...ALLOWING FOR THE BEST CHANCE OF SNOW MIXING INWILL BE AS THE BULK OF PRECIP PULLS OUT OF THE AREA. ALONG WITH THE PRECIP TYPE ISSUES...STRONG WINDS WILL ALSO BE A CONCERN. WITH RAPIDLY RISING HEIGHTS BEHIND THE SFC LOW THURSDAY...EXPECT A BREEZY DAY. ESPECIALLY ACROSS THE KEWEENAW PENINUSLA AND E ALONG LAKE SUPERIOR THANKS TO THE TERRAIN AND THE FACT THAT IT/S CLOSER TO THE GREATEST PRESSURE RISESMOVING ACROSS LAKE SUPERIOR. WITH 900MB WINDS OF 40-45KTS...EXPECT NEAR SFC WINDS OF 30-40KTS. WIND ADVISORIES MAY BE NEEDED. WINDS WILL QUICKLY DIMINISH W TO E THURSDAY EVENING. LOOK FOR THE SFC RIDGE SET UP ACROSS MN AND EXTENDING DOWN THROUGH MO AND THE TN VALLEY AT 06Z FRIDAY WILL SWING ACROSS THE UPPER GREAT LAKES 12-18Z FRIDAY...BEFORE SHIFTING ACROSS THE LOWER GREAT LAKES AND CENTRAL APPALACHIANS LATE IN THE DAY. THE RESULT WILL BE TEMPORARY DRY WEATHER FRIDAY-FRIDAY EVENING. JUST HOW FAST WAA PRECIP GETS INTO THE CWA IS IN QUESTION SATURDAY. THE ECMWF IS MUCH QUICKER TO BRING BACK PRECIP AT LEAST WITH THE 27/00Z RUN INDICATING A DEEPER SHORTWAVE NEARING IN THE BROAD TROUGH SET UP ACROSS MUCH OF THE CENTRAL PART OF THE NATION. EITHER WAY...WITH 850MB TEMPS OF 0-6C AND SFC TEMPS MAINLY ABOVE FREEZING...EXPECT LIQUID PRECIP INSTEAD OF FROZEN. THE SFC LOW HANGING OUT OVER W CANADA AND THE N PLAINS AT THE END OF THE WEEKEND SHOULD CONSOLIDATE OVER THE N PLAINS MONDAY AS SW FLOW SETS UP ALOFT IN RESPONSE TO A SIGNIFICANT TROUGH SET UP ACROSS THE W HALF OF N AMERICA. EXPECT THE S LOW TO EJECT NE INTO ONTARIO ON TUESDAY. EXPECT HIGHS IN THE 50S FROM SUNDAY THROUGH TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 208 PM EDT TUE OCT 27 2015 VFR CONDITIONS AT TAF SITES SHOULD CONTINUE UNDER ABUNDANT MID AND HIGH CLOUDS UNTIL ARRIVAL OF -RA FROM THE SW OVERNIGHT AHEAD OF SYSTEM LIFTING UP FROM THE CENTRAL PLAINS. CONDITIONS WILL THEN DROP TO MVFR WITH ONSET OF STEADIER RAIN LATE TONIGHT AND TO LIFR BY WEDNESDAY MORNING AS HIGHER DEWPOINT AIR WITH SYSTEM LEADS TO FORMATION OF LOW STRATUS AND FOG ACROSS THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 352 PM EDT TUE OCT 27 2015 WINDS WILL BEGIN TO INCREASE TONIGHT AHEAD OF A STRENGTHING LOW LIFTING TOWARD THE WRN LAKES. THE LOW WILL RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY EARLY THIS EVENING...INCREASING TO 20-30KT LATE TONIGHT. THE STRONGEST WINDS TONIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. WINDS WILL TEMPORARILY DIMINISH WED AFTERNOON/EVENING AS THE LOW LIFTS OVER UPPER MI AND LAKE SUPERIOR. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED NIGHT THRU THU WITH THE STRONGEST WINDS TO NEAR 45KT OVER THE E HALF OF THE LAKE BY THU. WINDS WILL DIMINISH TO UNDER 20KT W TO E LATE THU NIGHT/FRI AS A HIGH PRES RIDGE BUILDS IN FROM THE WEST AND GENERALLY REMAIN AT OR BELOW 20 KTS INTO SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...VOSS LONG TERM...KF AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EDT TUE OCT 27 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 352 PM EDT TUE OCT 27 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL TROUGH DEVELOPING FROM SASK/MANITOBA INTO THE WRN AND SCNTRL PLAINS WITH SEVERAL EMBEDDED SHORTWAVES. DOWNSTREAM...A RIDGE HAS BUILT INTO THE GREAT LAKES AND OHIO VALLEY. AT THE SFC...SE FLOW PREVAILED ACROSS THE UPPER GREAT LAKES BTWN HIGH PRES OVER NRN ONTARIO/WRN QUEBEC AND A TROUGH OVER THE WRN/SCNTRL PLAINS WHICH LED TO SOME UPSLOPE STRATUS/FOG AT KSAW AND KCMX EARLIER THIS MORNING. OTHERWISE...VIS SATELLITE LOOP SHOWED MID CLOUDS SPREADING ACROSS INTO WRN AND CENTRAL UPPER MI WITH PARTLY SUNNY SKIES OVER ERN UPR MI. TONIGHT AND WEDNESDAY...THE MODELS WERE IN GOOD AGREEMENT WITH A SHORTWAVE OVER THE SRN PLAINS LIFTING TOWARD THROUGH THE MID MS VALLEY AS A STRONGER SHRTWV OVER SRN SASK DROPS INTO SRN MANITOBA AND NORTH DAKOTA. A DEEPENING SFC LOW WILL ALSO LIFT TO SE WI BY 12Z WED. INCREASING SSE 800-700 MB FLOW OF 35-50 KNOTS AHEAD OF THE LOW WILL DRAW ABUNDANT MOISTURE TOWARD UPPER MI (PWAT TO AROUND 1.0 INCH) AND THIS IN COMBINATION WITH DEEP-LAYER Q-VECTOR CONV WILL ALLOW RAIN TO SPREAD ACROSS THE CWA LATE TONIGHT INTO WED MORNING. PHASING OF NRN AND SRN STREAM SHORTWAVES WILL ALLOW LONGWAVE TROUGH TO DEEPEN OVER THE CENTRAL CONUS ON WED. IN TURN...AS MID-UPPER LEVEL TROUGH DEEPENS...SFC LOW OF 995-1000MB OVER SRN WI WED MORNING WILL DEEPEN NEAR 985 MB OVER ERN LAKE SUPERIOR LATE WED. DIMINISHING ISENTROPIC ASCENT IN THE MID-LATE AFTERNOON AS SFC-850 MB LOW MOVES OVERHEAD AND Q-VECTOR DIVERGENCE SPREADS IN FM THE S-SE IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE SHOULD ALLOW RAIN TO GRADUALLY DIMINISH FROM THE SOUTH LATE AFTERNOON TOWARD EVENING. AS RAIN DIMINISHES FROM SOUTH LATE MORNING INTO AFTERNOON STRATUS WILL LOWER AND FOG MAY FORM ESPECIALLY FOR AREAS FAVORED BY UPSLOPE E-SE FLOW AS DEWPOINTS RISE INTO UPPER 40S/LOWER 50S. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 512 AM EDT TUE OCT 27 2015 DEEPENING LONGWAVE TROUGH OVER THE CENTRAL CONUS ON WEDNESDAY RESULTS FROM PHASING OF MANY INDIVIDUAL SHORTWAVES STRETCHING FROM BRITISH COLUMBIA THROUGH THE INTERMOUNTAIN WEST. AS TROUGH DEEPENS SFC LOW 995-1000MB DEVELOPS OVER IA/IL/SOUTHERN WI BY 12Z ON WED. MOIST ADVECTION OF PWATS OVER 1 INCH AHEAD OF H85 TROUGH AND SFC LOW ALONG WITH H85-H5 Q-VECTOR CONVERGENCE FM THE DEEPENING TROUGH SHOULD SPREAD THE RAIN CURRENTLY OVER LOWER MISSISSIPPI RIVER VALLEY ACROSS THE UPPER GREAT LAKES BY DAYBREAK ON WEDNESDAY. ISENTROPIC ASCENT 290-300K/H9-H65 ALONG WITH THE LARGER SCALE FORCING WITH SOME ADDITIONAL ASSIST TO RIGHT ENTRANCE REGION OF UPPER JET OVER ONTARIO WILL RESULT IN MODERATE RAIN OVER UPR MICHIGAN ON WEDNESDAY. AS THE ISENTROPIC ASCENT FADES IN THE MID-LATE AFTN AND Q-VECTOR DIVERGENCE SPREADS NORTH OVER CWA IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE EXPECT RAIN TO START TO DIMINISH. MID CONUS TROUGH CLOSES OFF SHARPLY INTO THURSDAY AS INITIAL CENTRAL CONUS TROUGH MOVING EAST PHASES WITH STRONG NORTHERN STREAM TROUGH DIGGING SSE FM SASKATCHEWAN AND MANITOBA ON WEDNESDAY MORNING TO THE WESTERN GREAT LAKES WEDNESDAY NIGHT. SFC LOW LIFTING FM THE MIDDLE MISSISSIPPI RIVER VALLEY DEEPENS TO NEAR 983-985MB AS IT REACHES SOUTH CENTRAL LK SUPERIOR WEDNESDAY EVENING THEN STAYS SIMILAR STRENGTH AS IT MOVES TO FAR EAST LK SUPERIOR OR JUST EAST OF LK SUPERIOR BY 12Z THURSDAY. TREND IS SLOWER IN MAJORITY OF GUIDANCE IN LIFTING THE LOW NORTH OF THE REGION. MAIN RESULT IS MORE WIDESPREAD PRECIP LINGERING OVER MUCH OF UPR MICHIGAN WEDNESDAY NIGHT INTO THURSDAY WITH TROWAL WORKING ACROSS WEST TO EAST AS SEEN IN THETA-E FIELDS WITH HEIGHT /ESPECIALLY H7-H6/ AND H7-H5 Q-VECTOR CONVERGENCE. ALSO SEE THE SLOWER TREND SHOW UP WITH WARMER AIR IN THE SFC-H85 LAYER ORIENTED EAST TO WEST ACROSS UPR MICHIGAN AND LK SUPERIOR. BIGGEST IMPACT IS ON SNOW POTENTIAL OVER WESTERN CWA. H85 TEMPS LAST NIGHT WERE AROUND -2C AT THE WARMEST AND -5C AT THE COOLEST BUT LATEST RUNS HAVE TRENDED WARMER. GFS/NAM SOUNDINGS AT IWD INDICATE EVEN WITH H85 TEMPS AROUND -2C OR -3C/GOOD ENOUGH FOR LAKE ENHANCEMENT WITH WATER TEMPS AROUND 8C AND PLENTY OF LARGE SCALE LIFT/MOISTURE/...WET BULB ZERO HEIGHTS REMAIN AT OR ABOVE 1000 FT AGL WHICH SUGGEST A MIX OF RAIN AND SNOW...BUT NOT MUCH SNOW ACCUMULATION. WILL BE TIGHT GRADIENT BTWN WHERE SNOW IS MAIN PYPE AND WHERE THERE WILL BE MIX OR JUST RAIN. RIGHT NOW BELIEVE THAT LINE WILL STAY MAINLY WEST AND SOUTH OF WESTERN CWA. TRENDED SNOW BACK OVER WESTERN INTERIOR TO LESS THAN 0.5 INCH. COOL AND BREEZY CONDITIONS EXPECTED ON THURSDAY ALL CWA. STRONGEST WINDS WILL BE ALONG LK SUPERIOR. SOLID 40-45 MPH IN THE MIXED LAYER THOUGH SLOWER TREND WITH SFC LOW AND LACK OF STRONG COLD AIR ADVECTION WILL COMPLICATE HOW QUICKLY THE STRONG WINDS MIX TO SFC. GOOD PORTION OF THESE WINDS WILL MAKE IT TO SFC AS GUSTS. GALES LOOK CERTAIN OVER LK SUPERIOR AND PROBABLY WILL NEED WIND ADVISORY HEADLINES ON ADJACENT SHORELINES OF NORTHERN UPR MICHIGAN. MOST FAVORED LOCATIONS TO SEE STRONGEST WINDS WOULD BE COPPER HARBOR AND MUNISING/GRAND MARAIS/FAR NORTHERN LUCE COUNTY. WINDS DIMINISH BY MIDNIGHT THURSDAY NIGHT. COOLEST AIR SETTLES ACROSS LK SUPERIOR ON THURSDAY NIGHT WITH H85 TEMPS DOWN TO -6C OR -7C. SOUNDINGS AT END OF FETCH OVER EASTERN LK SUPERIOR INDICATE SHALLOW MOIST LAYER AROUND H85 AND DRY SUB CLOUD LAYER. KEPT LOW CHANCES IN FOR LAKE EFFECT WITH SUFFICIENT OVERWATER INSTABILITY...BUT DRY AIR BLO CLOUD BASE AND FLOW BECOMING MORE ANTICYLONIC SHOULD ALLOW FOR DIMINISHING TREND TO LAKE EFFECT INTO FRIDAY. EXPECT SKIES TO STAY MOSTLY CLOUDY WITH INCREASING WARM AIR ADVECTION OCCURRING ATOP SHALLOW COLD LAYER. MID CLOUDS INCREASE IN THE AFTN AHEAD OF NEXT CHANCE OF RAIN WHICH ARRIVES OVERNIGHT FRIDAY NIGHT. GFS IS NOW JOINED BY ECMWF IN SHOWING SWATH OF RAIN SPREADING OVER UPPER GREAT LAKES LATE FRIDAY NIGHT INTO AT LEAST SATURDAY MORNING AHEAD OF SHORTWAVE TROUGH CROSSING THE NORTHERN PLAINS. STRONGEST LOW-LEVEL MOISTURE ADVECTION REMAINS MORE OVER CNTRL AND LOWER GREAT LAKES...SO LIKELY WILL NOT SEE TOO HIGH AMOUNTS OVER UPR MICHIGAN /AROUND 0.10 INCH BUT LESS THAN 0.25 INCH/. HALLOWEEN 2014 HAD SNOW OVER PARTS OF UPR MICHIGAN SO AT LEAST WILL NOT BE LOOKING AT ANYTHING THAT COLD. TEMPS ON SATURDAY TOP OUT IN THE UPR 40S TO NEAR 50 DEGREES. WARMING TREND STILL EXPECTED INTO FIRST PART OF NEXT WEEK WITH ONLY SMALL CHANCES OF RAIN AS IT STANDS NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 208 PM EDT TUE OCT 27 2015 VFR CONDITIONS AT TAF SITES SHOULD CONTINUE UNDER ABUNDANT MID AND HIGH CLOUDS UNTIL ARRIVAL OF -RA FROM THE SW OVERNIGHT AHEAD OF SYSTEM LIFTING UP FROM THE CENTRAL PLAINS. CONDITIONS WILL THEN DROP TO MVFR WITH ONSET OF STEADIER RAIN LATE TONIGHT AND TO LIFR BY WEDNESDAY MORNING AS HIGHER DEWPOINT AIR WITH SYSTEM LEADS TO FORMATION OF LOW STRATUS AND FOG ACROSS THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 352 PM EDT TUE OCT 27 2015 WINDS WILL BEGIN TO INCREASE TONIGHT AHEAD OF A STRENGTHING LOW LIFTING TOWARD THE WRN LAKES. THE LOW WILL RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY EARLY THIS EVENING...INCREASING TO 20-30KT LATE TONIGHT. THE STRONGEST WINDS TONIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. WINDS WILL TEMPORARILY DIMINISH WED AFTERNOON/EVENING AS THE LOW LIFTS OVER UPPER MI AND LAKE SUPERIOR. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED NIGHT THRU THU WITH THE STRONGEST WINDS TO NEAR 45KT OVER THE E HALF OF THE LAKE BY THU. WINDS WILL DIMINISH TO UNDER 20KT W TO E LATE THU NIGHT/FRI AS A HIGH PRES RIDGE BUILDS IN FROM THE WEST AND GENERALLY REMAIN AT OR BELOW 20 KTS INTO SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...VOSS LONG TERM...JLA AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
351 PM EDT TUE OCT 27 2015 .SHORT TERM...THIS EVENING AND TONIGHT HIGH CONTINUITY WITHIN THE NWP EXISTS THAT A COMPLEX WAVE MERGER EVENT WILL COMMENCE OVER THE GREAT LAKES BY EARLY THIS EVENING. THE FIRST PHASE OF THE WAVE MERGER/INTERACTION IS THE RAPID SURGE IN REMNANT HURRICANE PATRICIA MOISTURE DUE NORTHWARD INTO LOWER MICHIGAN. BULK ANALYSIS CONTINUES TO SUPPORT THAT A WAVE SEPARATION WILL EXIST BETWEEN THIS MIDLEVEL MOISTURE/PV ANOMALY AND THE MORE DOMINANT UPPER LEVEL PV ANOMALY DIGGING SOUTHWARD THROUGH ALBERTA. THERE IS IMPORTANCE IN THIS INFORMATION ON WAVE SEPARATION AS IT INCREASES CONFIDENCE THAT THE SLUG OF MIDLEVEL MOISTURE WILL KEEP PROGRESSING AND NOT STALL OUT. IF THERE HAS BEEN ONE NOTABLE TREND IT HAS BEEN FOR A SLIGHTLY SLOWER ONSET OF PRECIPITATION AND MOISTURE LIFTING NORTHWARD INTO SOUTHEASTERN MICHIGAN. A PERSISTENT LOW LEVEL EASTERLY WIND FEED WILL MAINTAIN A 12 KFT LAYER OF DRY AIR THAT WILL LIMIT ANY STRAY CHANCES AT THE FRONT END/EARLY EVENING. MUCH OF THE DETERMINISTIC SUITE AND CAMS INCLUDING SOME SUPPORT FROM HRRR 1KM REFLECTIVITY SUPPORTS HOLDING OFF PRECIPITATION SOUTH OF M 59 UNTIL 4Z THIS EVENING. THEREFORE...THE NARRATIVE BECOMES INCREASING WIDESPREAD RAIN DEVELOPING AFTER MIDNIGHT. MODELS ARE SHOWING A VERY EFFICIENT RESPONSE OF INCREASING MIDLEVEL SHEARING DEFORMATION THAT WILL FEAST ON THE AMOUNT OF REMNANT TROPICAL MOISTURE...EFFECTIVLY WRINGING OUT THE AVAILABLE MOISTURE WITHIN THE COLUMN. THERE ARE TWO SURGES OF HEAVIER RAINFALL RATES...THE FIRST LIFTING NORTHWARD THROUGH ALL AREAS PRIMARILY BETWEEN 06-09Z...THE SECOND ALIGNED NORTH TO SOUTH OVER THE FAR EASTERN CWA (WAYNE/MONROE/MACOMB/ST CLAIR/OAKLAND COUNTIES) BETWEEN 09-12Z. AGAIN...THERE IS FAIRLY HIGH CONFIDENCE IN RAINFALL AMOUNTS THROUGH 12 Z OF .70 TO .80 OF AN INCH. WITH THE ORIENTATION OF THE SECOND SURGE...HIGHEST RAIN AMOUNTS ARE EXPECTED FOR AREAS EAST OF THE IRISH HILLS/GLACIAL TERRAIN. OVERALL...THE POTENTIAL FOR THUNDER REMAINS LOW...THE THERMODYNAMIC PROFILE REMAINS A FAIRLY STABLE ONE THROUGH 10 KFT AGL. && .LONG TERM... NWP IN REMARKABLE AGREEMENT GIVEN MYRIAD MOVING PARTS INVOLVED IN A DYNAMIC SCENARIO THAT WILL PLAY OUT OVER THE NEXT 48 HOURS. LOCALLY, THE LONG TERM PERIOD WILL BEGIN WITH A CARRYOVER OF TONIGHT`S WEATHER. VERY STRONG UPPER-LEVEL DIVERGENCE WILL BE DIRECTLY OVERHEAD, BUT IN THE PROCESS OF EXITING EAST ALONG WITH THE REST OF THE FIRST WAVE OF MOISTURE AND FORCING. THE RAIN WILL MAINTAIN ITS OVERNIGHT CHARACTER THROUGH THE EARLY MORNING, BUT WILL QUICKLY WIND DOWN FROM SOUTHWEST TO NORTHEAST 12-15Z. ATTENTION THEN TURNS TO THE DEEPENING LONGWAVE TROUGH OVER THE WEST- CENTRAL UNITED STATES TODAY. WATER VAPOR REVEALS A PLETHORA OF EMBEDDED SHORTWAVES FROM MONTANA TO TEXAS. FURTHER NORTH, A WELL- DEFINED PV RIBBON IS DIVING SOUTH AND IS FORECAST TO UNDERGO RAPID AMPLIFICATION OVER THE NORTHERN PLAINS AND UPPER MIDWEST TONIGHT INTO WEDNESDAY. AS THE INITIAL MOISTURE SURGE PUSHES EAST WED MORNING, SOME CONSOLIDATION OF SAID DISTURBANCES IS FORECAST TO OCCUR, PARTICULARLY ABOVE 500MB. THE FLOW AROUND THE ASSOCIATED CONSOLIDATED H4-H3 PV ANOMALY WILL DRAW IN PLENTY OF DRY AIR AND SOUTHEAST MICHIGAN WILL SPEND THE MAJORITY OF THE DAYTIME HOURS WITHIN A DRY SLOT, ALBEIT NOT A CLASSIC ONE, AS A RESULT. CONVECTIVE SHOWERS ALONG THE CONVERGENT LEAD EDGE OF THE DRY SLOT ARE A POSSIBILITY, AND THESE COULD PRODUCE SPORADIC WIND GUSTS OF 40 TO 50 MPH. THIS THREAT, IF IT DEVELOPS, WILL BE SHORT-LIVED AS MID AND UPPER LEVEL MOISTURE WILL BE SCOURED OUT AND FRONTAL-TYPE FORCING WILL QUICKLY MOVE EAST. SEEING AS HOW THE DRY SLOT WILL REMAIN ELEVATED, ELEVATED COOLING ASSOCIATED WITH THE PASSAGE OF THIS WAVE DURING PEAK HEATING WILL LEND ITSELF AT LEAST TO SOME AFTERNOON DRIZZLE PRODUCTION IF NOT LOW-TOPPED SHOWERS GIVEN SUFFICIENT LINGERING MOISTURE DEPTH. BY THIS TIME, THE AFOREMENTIONED VERY DYNAMIC HIGH-LATITUDE WAVE WILL BE IN FIRM CONTROL OF THE LARGER SCALE CIRCULATION AND WILL BE SLAMMING INTO THE GREAT LAKES IN THE UPPER LEVELS. IT WILL TAKE ON AN INCREASINGLY NEUTRAL TILT, FORCING THE UPPER JET TO TRANSLATE RAPIDLY DOWNSTREAM FROM THE EASTERN PLAINS AT 21Z WED TO THE LOWER GREAT LAKES 12Z THURS. ELEVATED FGEN PROCESSES WILL AID THE PRODUCTION OF A SIGNIFICANT TROPOPAUSE UNDULATION AS THIS OCCURS, AND THE DEEP TROPOSPHERIC COLD FRONT WILL UNDERGO STEADY INTENSIFICATION AS THE JET-FRONT COUPLET MATURES. ALTHOUGH THE TEMPERATURE GRADIENT ACROSS THE FRONT IS NOT AT ALL IMPRESSIVE AS FAR AS AUTUMN COLD FRONTS GO, STRONG DYNAMIC FORCING AT ALL LEVELS WILL STILL CAUSE IT TO PACK A PUNCH AS IT RACES WEST-TO-EAST ACROSS SE MICHIGAN 06-09Z. COLD FROPA WILL REPRESENT THE BEST POSSIBILITY FOR HIGHER END WINDS. FIRST, THERE IS THE FRONT ITSELF. WHILE NOT EXHIBITING CLASSIC DENSITY CURRENT CHARACTERISTICS, INSTABILITY IN THE NOSE OF THE FRONTAL ZONE STILL LOOKS SUFFICIENT TO PRODUCE ENOUGH VIGOROUS MIXING AND BRIEF HIT OF WIND GUSTS AROUND WIND ADVISORY CRITERIA. IN FACT, NAM12 DEPICTIONS OF DOWNWARD MOMENTUM TRANSPORT ON THE 284K SURFACE SUGGEST 38-44KTS IS ACHIEVABLE. THIS REPRESENTS A WINDOW FOR A POTENTIAL SHORT-FUSED WIND ADVISORY BETWEEN ABOUT 05Z-10Z THURSDAY MORNING. SECOND, DEEP AND STRONG FRONTAL FORCING WILL CAUSE A LINE OF CONVECTION ALONG THE FRONT LIKEWISE CAPABLE OF MIXING DOWN SIMILARLY STRONG WINDS. COLD ADVECTION WILL FORCE STRONG SYSTEM RELATIVE ISENTROPIC ASCENT THROUGH MUCH OF THURSDAY, BUT A LACK OF ANY REAL COLD AIR BEHIND THE FRONT WILL REALLY LIMIT POTENTIAL IN THIS OTHERWISE FAVORABLE SETUP. FURTHER, THE SLOWLY DEEPENING NATURE OF THE NOW-DISTANT SURFACE CYCLONE WILL CONTRIBUTE JUST A MINIMAL ISALLOBARIC COMPONENT TO WIND GUSTS. CURRENT THINKING IS THAT, AFTER AN INITIAL POP OF WINDS WITH FROPA, POST-FRONTAL WINDS ON THURSDAY TOP OUT BELOW THE 38KT/45MPH WIND ADVISORY THRESHOLD. BETWEEN CLOUDS AND COLD ADVECTION, THURSDAY`S TEMPERATURE RESPONSE WILL BE MUTED. WENT BELOW NEARLY ALL GUIDANCE WITH MID 40S ALONG THE GLACIAL RIDGE AND UPPER 40S ELSEWHERE. SHORTWAVE UPPER RIDGING AND ASSOCIATED SURFACE HIGH BUILDING INTO THE GREAT LAKES REGION FRIDAY AS THE STRONG LOW PULLS AWAY SHOULD PROVIDE FOR A PLEASANT LATE FALL DAY...WITH DIMINISHING WINDS...MAINLY SUNNY SKIES...AND HIGHS AROUND 50. PATTERN REMAINS PROGRESSIVE THANKS TO A STRONG PACIFIC JET COMING ASHORE. THIS FLOW WILL BREAK DOWN INTO A FULL LATITUDE TROUGH...WITH 12Z SUITE CONTINUING TO ZIP THE NORTHERN PORTION OF THE TROUGH ACROSS THE NORTHERN CONUS...WHILE THE SOUTHERN PORTION CUTS OFF OVER THE SOUTHWEST US. RETURN FLOW IN ADVANCE OF THE FORMER FEATURE AND ON THE BACKSIDE OF THE DEPARTING HIGH WILL ALLOW MOISTURE TO INCREASE LOCALLY SATURDAY...WITH ACCOMPANYING RAIN CHANCES THROUGH SATURDAY NIGHT. PREDICTABILITY REMAINS LOW SUNDAY INTO NEXT WEEK WITH HOW QUICKLY THE SOUTHWEST US CUTOFF EJECTS...BROAD BRUSH LOW POPS FOR NOW WILL BE REFINED IN THE FUTURE. A FAIRLY GOOD CHANCE FOR TEMPS WELL ABOVE NORMAL AS WE TURN THE PAGE TO NOVEMBER DUE TO LACK OF COLD AIR WITH THE DEAMPLIFYING NORTHERN STREAM TROUGH AND CONTINUED WARM ADVECTION AHEAD OF THE SOUTHERN STREAM TROUGH. && .MARINE... A STRENGTHENING LOW WILL LIFT ACROSS THE WESTERN GREAT LAKES INTO CANADA BRINGING A PERIOD OF SOUTHEAST GALES TONIGHT INTO EARLY WEDNESDAY. GALE WARNINGS AND SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THIS GALE EVENT. A STRONG COLD FRONT WILL RACE ACROSS THE WATERS LATE THURSDAY NIGHT BRINGING GALES...AND LOCALLY STRONG GALES...TO AREA WATERS. FOR AREAS NOT EXPECTED TO EXPERIENCE GALES TONIGHT....GALE WATCHES ARE IN EFFECT FOR THIS SECOND GALE EVENT. SIGNIFICANT WAVE HEIGHTS WILL PEAK AROUND 8 TO 11 FEET FOR BOTH EVENTS. MAXIMUM WAVE HEIGHTS OF 15 TO 20 FEET WILL POSSIBLE IN FAVORED AREAS...MAINLY THE OPEN WATERS OF CENTRAL LAKE HURON. && .AVIATION...ISSUED 213 PM EDT TUE OCT 27 2015 HIGH MIDLEVEL MOISTURE CONTENT WILL BE DRAWN NORTHWARD THIS EVENING IN ADVANCE OF A DEEPENING LOW PRESSURE SYSTEM OVER THE NORTHERN MISSISSIPPI RIVER VALLEY. AN AXIS OF THE DEEP MIDLEVEL MOISTURE IS FORECASTED TO LIFT DIRECTLY NORTHWARD THROUGH THE TERMINALS...AFFECTING THE SITES PRIMARILY BETWEEN 06-15Z. DELAYED ARRIVAL OF LOWER CIGS AND RAIN FOR THE NORTHERN TAF SITES BY AN HOUR OR TWO...OTHERWISE TIMING OFFERED BY THE PREVIOUS SET OF TAFS LOOK GOOD FOR KPTK SOUTHWARD. THERE IS A HIGH LIKLIHOOD FOR IFR CONDITIONS VERY LATE TONIGHT WITH SOME POTENTIAL FOR LIFR AT DAYBREAK. CONFIDENCE IS INCREASING THAT IFR CIGS WILL PERSIST INTO THE LATE MORNING AND POSSIBLY INTO THE EARLY AFTERNOON. EAST WINDS ARE FORECASTED TO PERSIST IN THE 10 TO 20 KNOT RANGE THROUGHOUT THE TAF FORECAST. FOR DTW...EASTERLY WIND OF 090-120 WIND AT 10 TO 20 KNOTS WILL CONTINUE THROUGH TONIGHT. LITTLE TIME REFINEMENT IN CIG/PRECIPITATION TIMING WAS NEEDED THIS ISSUANCE. CONFIDENCE REMAINS HIGH IN IFR CIGS/VSBYS LATE TONIGHT AND WEDNESDAY MORNING. CONFIDENCE IS LOW ON POTENTIAL FOR LIFR CONDITIONS. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILING BELOW 5000 FT TONIGHT. * MEDIUM FOR EXCEEDING CROSSWIND THRESHOLD FROM 140 BY TONIGHT. * LOW TO MEDIUM FOR CEILING AOB 200 FEET DEVELOPING TOWARD 12Z WEDNESDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...GALE WARNING FROM 5 AM TO 2 PM EDT WEDNESDAY FOR LHZ361>363-462-463. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LHZ421-422. GALE WARNING FROM 5 AM TO 11 AM EDT WEDNESDAY FOR LHZ421-441>443- 464. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO MIDNIGHT EDT WEDNESDAY NIGHT FOR LHZ422. LAKE ST CLAIR...GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LCZ460. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT WEDNESDAY NIGHT FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LEZ444. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT WEDNESDAY NIGHT FOR LEZ444. && $$ SHORT TERM...CB LONG TERM....JVC/DT MARINE.......JVC AVIATION.....CB YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
223 PM EDT TUE OCT 27 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 518 AM EDT TUE OCT 27 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL TROUGH DEVELOPING FROM SASK/ALBERTA INTO THE NRN ROCKIES AND WRN PLAINS WITH SEVERAL EMBEDDED SHORTWAVES. DOWNSTREAM...A RIDGE WAS BUILDING FROM THE UPPER MS VALLEY TO THE WRN GREAT LAKES. A THE SFC...SE FLOW PREVAILED THROUGH THE REGION BTWN HIGH PRES OVER NRN ONTARIO AND QUEBEC AND A TROUGH OVER THE WRN PLAINS. A BAND OF LIGHT SHOWERS OR SPRINKLES ASSOCIAED WITH WAA AND 295K ISENTROPIC LIFT NORTH OF A SFC FRONT THROUGH SRN MN. OTHERWISE...IR LOOP SHOWED MID CLOUDS SPREADING ACROSS UPPER MI WHERE AREAS OF LOW CLOUDS AND PATCHY FOG HAD ALSO DEVELOPED. TODAY...RADAR TRENDS AND SHORT RANGE MODELS SUGGEST THAT THE AREA OF LIGHT PCPN FROM N CNTRL MN INTO NW WI WILL CONTINUE TO LIFT TO THE NNE WITH ONLY A FEW SPRINKLES POSSIBLE OVER THE FAR WEST BEFORE 15Z. OTHERWISE...DRIER AIR FROM 925-850 MB MOVING IN FROM THE SOUTH COMBINED WITH LIMITED DAYTIME HEATING/MIXING SHOULD HELP SCOUR OUR THE LOWER CLOUDS THIS MORNING. HOWEVER...MID LEVEL CLOUDS WILL CONTINUE TO THICKEN. NEVERTHELESS...WAA WILL HELP PUSH HIGH TEMPS INTO THE LOWER TO MID 50S. TONIGHT...THE MODELS WERE IN GOOD AGREEMENT WITH THE CNTRL PLAINS SHORTWAVE LIFTING TOWARD IA AS A STRONGER SHRTWV OVER CNTRL SASK DROP INTO SRN MANITOBA. A DEEPENING SFC LOW WILL ALSO LIFT TO SRN WI. INCREASING SRLY 80-700 MB FLOW TO 40-50 KNOTS WILL DRAW ABUNDANT MOISTURE TOWARD UPPER MI (PWAT TO AROUND 1.0 INCH) WITH RAIN SPREADING ACROSS THE CWA LATE...MAINLY BTWN 09Z-12Z. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 512 AM EDT TUE OCT 27 2015 DEEPENING LONGWAVE TROUGH OVER THE CENTRAL CONUS ON WEDNESDAY RESULTS FROM PHASING OF MANY INDIVIDUAL SHORTWAVES STRETCHING FROM BRITISH COLUMBIA THROUGH THE INTERMOUNTAIN WEST. AS TROUGH DEEPENS SFC LOW 995-1000MB DEVELOPS OVER IA/IL/SOUTHERN WI BY 12Z ON WED. MOIST ADVECTION OF PWATS OVER 1 INCH AHEAD OF H85 TROUGH AND SFC LOW ALONG WITH H85-H5 Q-VECTOR CONVERGENCE FM THE DEEPENING TROUGH SHOULD SPREAD THE RAIN CURRENTLY OVER LOWER MISSISSIPPI RIVER VALLEY ACROSS THE UPPER GREAT LAKES BY DAYBREAK ON WEDNESDAY. ISENTROPIC ASCENT 290-300K/H9-H65 ALONG WITH THE LARGER SCALE FORCING WITH SOME ADDITIONAL ASSIST TO RIGHT ENTRANCE REGION OF UPPER JET OVER ONTARIO WILL RESULT IN MODERATE RAIN OVER UPR MICHIGAN ON WEDNESDAY. AS THE ISENTROPIC ASCENT FADES IN THE MID-LATE AFTN AND Q-VECTOR DIVERGENCE SPREADS NORTH OVER CWA IN WAKE OF INITIAL SOUTHERN STREAM SHORTWAVE EXPECT RAIN TO START TO DIMINISH. MID CONUS TROUGH CLOSES OFF SHARPLY INTO THURSDAY AS INITIAL CENTRAL CONUS TROUGH MOVING EAST PHASES WITH STRONG NORTHERN STREAM TROUGH DIGGING SSE FM SASKATCHEWAN AND MANITOBA ON WEDNESDAY MORNING TO THE WESTERN GREAT LAKES WEDNESDAY NIGHT. SFC LOW LIFTING FM THE MIDDLE MISSISSIPPI RIVER VALLEY DEEPENS TO NEAR 983-985MB AS IT REACHES SOUTH CENTRAL LK SUPERIOR WEDNESDAY EVENING THEN STAYS SIMILAR STRENGTH AS IT MOVES TO FAR EAST LK SUPERIOR OR JUST EAST OF LK SUPERIOR BY 12Z THURSDAY. TREND IS SLOWER IN MAJORITY OF GUIDANCE IN LIFTING THE LOW NORTH OF THE REGION. MAIN RESULT IS MORE WIDESPREAD PRECIP LINGERING OVER MUCH OF UPR MICHIGAN WEDNESDAY NIGHT INTO THURSDAY WITH TROWAL WORKING ACROSS WEST TO EAST AS SEEN IN THETA-E FIELDS WITH HEIGHT /ESPECIALLY H7-H6/ AND H7-H5 Q-VECTOR CONVERGENCE. ALSO SEE THE SLOWER TREND SHOW UP WITH WARMER AIR IN THE SFC-H85 LAYER ORIENTED EAST TO WEST ACROSS UPR MICHIGAN AND LK SUPERIOR. BIGGEST IMPACT IS ON SNOW POTENTIAL OVER WESTERN CWA. H85 TEMPS LAST NIGHT WERE AROUND -2C AT THE WARMEST AND -5C AT THE COOLEST BUT LATEST RUNS HAVE TRENDED WARMER. GFS/NAM SOUNDINGS AT IWD INDICATE EVEN WITH H85 TEMPS AROUND -2C OR -3C/GOOD ENOUGH FOR LAKE ENHANCEMENT WITH WATER TEMPS AROUND 8C AND PLENTY OF LARGE SCALE LIFT/MOISTURE/...WET BULB ZERO HEIGHTS REMAIN AT OR ABOVE 1000 FT AGL WHICH SUGGEST A MIX OF RAIN AND SNOW...BUT NOT MUCH SNOW ACCUMULATION. WILL BE TIGHT GRADIENT BTWN WHERE SNOW IS MAIN PYPE AND WHERE THERE WILL BE MIX OR JUST RAIN. RIGHT NOW BELIEVE THAT LINE WILL STAY MAINLY WEST AND SOUTH OF WESTERN CWA. TRENDED SNOW BACK OVER WESTERN INTERIOR TO LESS THAN 0.5 INCH. COOL AND BREEZY CONDITIONS EXPECTED ON THURSDAY ALL CWA. STRONGEST WINDS WILL BE ALONG LK SUPERIOR. SOLID 40-45 MPH IN THE MIXED LAYER THOUGH SLOWER TREND WITH SFC LOW AND LACK OF STRONG COLD AIR ADVECTION WILL COMPLICATE HOW QUICKLY THE STRONG WINDS MIX TO SFC. GOOD PORTION OF THESE WINDS WILL MAKE IT TO SFC AS GUSTS. GALES LOOK CERTAIN OVER LK SUPERIOR AND PROBABLY WILL NEED WIND ADVISORY HEADLINES ON ADJACENT SHORELINES OF NORTHERN UPR MICHIGAN. MOST FAVORED LOCATIONS TO SEE STRONGEST WINDS WOULD BE COPPER HARBOR AND MUNISING/GRAND MARAIS/FAR NORTHERN LUCE COUNTY. WINDS DIMINISH BY MIDNIGHT THURSDAY NIGHT. COOLEST AIR SETTLES ACROSS LK SUPERIOR ON THURSDAY NIGHT WITH H85 TEMPS DOWN TO -6C OR -7C. SOUNDINGS AT END OF FETCH OVER EASTERN LK SUPERIOR INDICATE SHALLOW MOIST LAYER AROUND H85 AND DRY SUB CLOUD LAYER. KEPT LOW CHANCES IN FOR LAKE EFFECT WITH SUFFICIENT OVERWATER INSTABILITY...BUT DRY AIR BLO CLOUD BASE AND FLOW BECOMING MORE ANTICYLONIC SHOULD ALLOW FOR DIMINISHING TREND TO LAKE EFFECT INTO FRIDAY. EXPECT SKIES TO STAY MOSTLY CLOUDY WITH INCREASING WARM AIR ADVECTION OCCURRING ATOP SHALLOW COLD LAYER. MID CLOUDS INCREASE IN THE AFTN AHEAD OF NEXT CHANCE OF RAIN WHICH ARRIVES OVERNIGHT FRIDAY NIGHT. GFS IS NOW JOINED BY ECMWF IN SHOWING SWATH OF RAIN SPREADING OVER UPPER GREAT LAKES LATE FRIDAY NIGHT INTO AT LEAST SATURDAY MORNING AHEAD OF SHORTWAVE TROUGH CROSSING THE NORTHERN PLAINS. STRONGEST LOW-LEVEL MOISTURE ADVECTION REMAINS MORE OVER CNTRL AND LOWER GREAT LAKES...SO LIKELY WILL NOT SEE TOO HIGH AMOUNTS OVER UPR MICHIGAN /AROUND 0.10 INCH BUT LESS THAN 0.25 INCH/. HALLOWEEN 2014 HAD SNOW OVER PARTS OF UPR MICHIGAN SO AT LEAST WILL NOT BE LOOKING AT ANYTHING THAT COLD. TEMPS ON SATURDAY TOP OUT IN THE UPR 40S TO NEAR 50 DEGREES. WARMING TREND STILL EXPECTED INTO FIRST PART OF NEXT WEEK WITH ONLY SMALL CHANCES OF RAIN AS IT STANDS NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 208 PM EDT TUE OCT 27 2015 VFR CONDITIONS AT TAF SITES SHOULD CONTINUE UNDER ABUNDANT MID AND HIGH CLOUDS UNTIL ARRIVAL OF -RA FROM THE SW OVERNIGHT AHEAD OF SYSTEM LIFTING UP FROM THE CENTRAL PLAINS. CONDITIONS WILL THEN DROP TO MVFR WITH ONSET OF STEADIER RAIN LATE TONIGHT AND TO LIFR BY WEDNESDAY MORNING AS HIGHER DEWPOINT AIR WITH SYSTEM LEADS TO FORMATION OF LOW STRATUS AND FOG ACROSS THE AREA. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 525 AM EDT TUE OCT 27 2015 WINDS WILL BEGIN TO INCREASE TODAY INTO TONIGHT AHEAD OF A STRENGTHING LOW LIFTING TOWARD THE WRN LAKES. THE LOW WILL RAPIDLY DEEPEN AS IT MOVES ACROSS THE UPPER GREAT LAKES WED AFTN/NIGHT ON ITS WAY TO JAMES BAY THU. WINDS ACROSS MUCH OF LAKE SUPERIOR WILL BE INTO THE 15-25KT RANGE BY LATE THIS AFTERNOON...INCREASING FURTHER TO 20-30KT TONIGHT. THE STRONGEST WINDS TONIGHT WILL BE FAVORED FOR CNTRL/ERN LAKE SUPERIOR...TYPICAL FOR SE FLOW. WINDS WILL TEMPORARILY DIMINISH IN THE VNCTY OF THE LOW/FRONT AS THEY MOVE ACROSS LAKE SUPERIOR WED. NW GALES WILL THEN DEVELOP BEHIND THE LOW LATE WED THRU THU WITH THE STRONGEST WINDS TO AROUND 40KT OVER THE E HALF OF THE LAKE. WINDS WILL DIMINISH TO UNDER 20KT W TO E THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR LSZ267. GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR LSZ265-266. GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LSZ263-264. LAKE MICHIGAN... GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR LMZ221-248-250. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...VOSS MARINE...NONE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
317 PM CDT TUE OCT 27 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 317 PM CDT TUE OCT 27 2015 THE PRIMARY FORECAST CONCERN IN THE SHORT TERM WILL BE GUSTY NORTHWEST WINDS BEHIND A COLD FRONT. FOR THIS EVENING....THE COLD FRONT IS CURRENTLY WORKING SOUTHEAST ACROSS OUR NORTHWEST AND WESTERN ZONES. CLOUDS WITH LIGHT QPF HAVE BEEN ASSOCIATED WITH THE FRONTAL PASSAGE. THE CURRENT KLNX 88D SCAN REVEALS A BROKEN LINE OF SHOWERS/THUNDERSTORM FROM NORTHEASTERN COLORADO NORTH ACROSS DEUEL...WESTERN GARDEN AND EVENTUALLY CENTRAL SHERIDAN COUNTY. NEAR TERM GUIDANCE LOOSELY HAS THE SITUATION RESOLVED...SO WILL GO WITH A GENERAL BLEND OF THE NAM AND LATEST HRRR WITH THE PREVIOUS FORECAST. THE RESULT IS SLIGHT CHANCE TO CHANCE POPS ACROSS THE EASTERN PANHANDLE SOUTH AND EAST THROUGH OUR SOUTHERN ZONES THROUGH THIS EVENING AS THE ACTIVITY GENERALLY DROPS TO THE SOUTHEAST. THERE IS AN ABRUPT END TO PRECIPITATION CHANCES THIS EVENING AS MUCH OF THE ACTIVITY SHOULD BE DIURNALLY DRIVEN. THIS EVENING...WILL NEED TO WATCH A COMPACT PV ANOMALY THAT WILL PUSH SOUTHEAST FROM THE PANHANDLE ACROSS OUR SOUTHERN ZONES. WITH THE FRONTAL PASSAGE INCREASING WINDS ALOFT AND THE PV MAX WOULD ALLOW FOR BREEZY CONDITIONS WELL INTO THE OVERNIGHT HOURS. HOWEVER THE STRONGEST WINDS WILL BEGIN AFTER SUN UP WEDNESDAY WHEN A 100KT+ H5 JET DIVES SOUTH FROM THE NORTHERN PLAINS AND COMBINES WITH SUBSTANTIAL SFC PRESSURE FALLS...AND SOLID MIXING AS LOW AND MID LEVEL LAPSE RATES INCREASE. THERE/S POTENTIAL OF GUSTS IN EXCESS OF 45MPH ACROSS NORTH CENTRAL NEBRASKA...AND IF WE MIX TO THE FULL POTENTIAL /ABOVE H7/...50MPH WOULD BE POSSIBLE. ATTM WE FEEL THE 45 MPH GUSTS SHOULD BE THE UPPER LIMIT. THE WIND/MIXING OVERNIGHT WILL OFFSET THE RADIATIONAL COOLING AND POST FRONTAL CAA...BUT STILL...LOWS ARE FORECAST TO FALL INTO THE UPPER 20S /NORTHWEST/...30S ELSEWHERE. SOME OF THE GUIDANCE INDICATES THE ATMOSPHERE PARTIALLY DECOUPLING NEAR DAWN...IF THIS OCCURS...TEMPERATURES MAY BE COOLER. HIGHS ON WEDNESDAY ARE A PRODUCT OF THE MET/MAV GUIDANCE AND THE PREVIOUS FORECAST. PLENTIFUL CAA WILL PROMOTE HIGHS OF ONLY THE UPPER 40S FOR THE NORTH...NEAR 60 OVER THE SOUTH. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 317 PM CDT TUE OCT 27 2015 A MODIFIED CANADIAN AIRMASS WILL BE IN PLACE ACROSS THE NRN AND CNTRL PLAINS WEDNESDAY NIGHT AS SURFACE HIGH PRESSURE SETTLES OVERHEAD. MODEL GUIDANCE CONTINUES TO SUPPORT LOWS IN THE UPPER TEENS ACROSS THE NWRN SANDHILLS...LOWER 20S CENTRAL SANDHILLS...TO THE UPPER 20S FAR NERN ZONES. HIGHS ON THURSDAY WILL BE AFFECTED BY CANADIAN AIRMASS AS THE SURFACE HIGH DRIFTS EASTWARD AND A LIGHT SOUTHERLY RETURN FLOW BEGINS. WITH FULL SUNSHINE AND LIMITED MIXING...HIGHS NEAR PREVIOUS FCST FROM NEAR 55 SWRN NEBR TO NEAR 50 IN THE NORTHEAST. A PROGRESSIVE POSITIVELY TILTED SYSTEM WILL APPROACH THURSDAY NIGHT WITH A MOISTURE RETURN FROM TEXAS INTO KANSAS. A 20 TO 30 PERCENT CHANCE FOR SHOWERS FRIDAY MORNING...WITH 30 TO 50 POPS FRIDAY AFTN EAST OF AINSWORTH THROUGH MULLEN AND OGALLALA. PREFERRED THE SLOWER TIMING OF THE 12Z GFS RUN OVER THE NAM. CHC POPS INTO FRIDAY NIGHT ACROSS THE SOUTHEAST AS UPPER TROUGH EXITS. DRY WITH A WARMING TREND SATURDAY THROUGH MONDAY. WARM AIR ADVECTION TO OCCUR AS AN UPPER TROUGH DIGS INTO THE PAC NW SUNDAY/MONDAY WITH HIGHS AROUND 70 EACH DAY. A WEAK COLD FRONT MONDAY NIGHT WITH SLIGHTLY COOLER HIGHS TUESDAY IN THE UPPER 50S TO LOWER 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1234 PM CDT TUE OCT 27 2015 A COLD FRONT WILL PROMOTE GUSTY CONDITIONS THROUGH THE TAF FORECAST PERIOD FOR ALL WEST CENTRAL NEBRASKA TERMINALS. TIMING OF THE FRONT IS SLATED TO ARRIVE AT KVTN BEFORE 21Z...AND CROSS THE KLBF TERMINAL BY 00Z THIS EVENING. MODEL GUIDANCE WAS DEEMED A BIT LIGHT ON SPEEDS...ESPECIALLY OVERNIGHT TONIGHT AND ON WEDNESDAY...THUS SUBSEQUENT AVIATION FORECASTS MAY NUDGE SPEEDS HIGHER...BUT FOR NOW GUSTS IN EXCESS OF 25 KTS ARE POSSIBLE. STRATUS IS ACCOMPANYING THE FRONTAL PASSAGE...MVFR CEILINGS ARE EXPECTED WITH THE POSSIBILITY OF LIGHT QPF. BUT AS OF NOW...THE PROBABILITY OF SHOWERS IMPACTING EITHER KLBF OR KVTN IS LOW /LESS THAN 30 PERCENT/. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JACOBS LONG TERM...ROBERG AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
700 PM EDT TUE OCT 27 2015 .SYNOPSIS...A SERIES OF DISTURBANCES WILL PASS OVER THE AREA THROUGH WEDNESDAY... AS A WARM FRONT MOVES GRADUALLY TOWARD THE NORTHWEST AND NORTH THROUGH THE REGION. THE PASSAGE OF A COLD FRONT THURSDAY WILL USHER CANADIAN HIGH PRESSURE INTO THE EASTERN STATES FOR FRIDAY AND SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 700 PM TUESDAY... UPDATE...AN INITIAL WEAK MID LEVEL DISTURBANCE IS LIFTING ACROSS THE NORTHERN TIER OF THE AREA EARLY TONIGHT WITH DIMINISHING RAIN COVERAGE ACROSS THE SOUTH. THIS LULL LOOKS TO BE SHORT LIVED... HOWEVER...AS ANOTHER WEAK DISTURBANCE...BARELY VISIBLE ON H2O VAPOR IMAGERY BUT WELL-DEFINED ON RAP AND GFS...WILL BE LIFTING NORTH ACROSS THE AREA OVERNIGHT. AS SUCH...ONGOING ~100 POPS LOOK GOOD. SIMILARLY... THERE HAS BEEN A SLIGHT BUMP UPWARDS IN THE TEMPS ACROSS THE NORTHWEST OVER THE PAST COUPLE OF HOURS...SUPPORTING THE VERY GRADUAL RISE EXPECTED OVERNIGHT ACROSS THE AREA AS WARM AIR ADVECTION ALOFT CONTINUES TO PECK AWAY AT THE COOL AIRMASS. CLASSICAL COLD AIR DAMMING OCCURRING WITH A PARENT HIGH (1035MB) SLOWLY DRIFTING OFFSHORE OF NEW ENGLAND. MEANWHILE EAST-SELY FLOW JUST A COUPLE THOUSAND FEET OFF THE SURFACE WAS STRENGTHENING IN RESPONSE TO THE APPROACH OF A MID-UPPER LEVEL S/W OR SHEAR AXIS. THIS OVERRUNNING SET-UP WILL MAINTAIN PERIODS OF RAIN OVER CENTRAL NC THROUGH THE EVENING HOURS. AS SHEAR AXIS LIFTS NEWD AND EXITS OUR REGION AFTER MIDNIGHT...RAIN COVERAGE EXPECTED TO BECOME MORE SPOTTY AND LIGHTER IN INTENSITY. A COASTAL TROUGH WAS ANALYZED NEAR OR JUST OFFSHORE OF THE NC COAST AT 19Z. THIS FEATURE WILL SLOWLY DRIFT INLAND OVERNIGHT. MODEL GUIDANCE SUGGEST THIS FEATURE WORKING ITS WAY THROUGH OUR REGION LATE TONIGHT THROUGH WEDNESDAY MORNING. THIS SUGGEST TEMPS HOLDING STEADY OVER MOST OF CENTRAL NC THROUGH THE EVENING HOURS THEN SLOWLY RISING...ESPECIALLY EAST OF THE HIGHWAY 1 CORRIDOR AFTER MIDNIGHT. BY DAYBREAK...MOST LOCATIONS EXCLUDING THE NW PIEDMONT SHOULD BE AT OR ABOVE 60 DEGREES. WHILE VISIBILITIES SHOULD BE IN THE 2-5 MILE RANGE DUE TO RAIN AND/OR LIGHT FOG...ATMOSPHERE APPEARS TO WELL MIXED TO CAUSE AREAS OF DENSE FOG TO DEVELOP. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 345 PM TUESDAY... WEDNESDAY...AN AMPLIFYING UPEPR LEVEL TROUGH EXTENDING FROM THE GREAT LAKES INTO THE TN VALLEY WILL SEND A SERIES OF S/W INTO CENTRAL NC WEDNESDAY AND WEDNESDAY NIGHT. THE APPROACH OF THIS SYSTEM WILL AID TO STRENGTHEN THE LOW-MID LEVEL FLOW OUT OF THE SOUTH OVER CENTRAL NC. THE NEAR SURFACE FLOW WILL ADVECT A WARM HUMID AIR MASS INTO OUR REGION. THE STRENGTHENING FLOW WILL INCREASE THE 0-6KM BULK SHEAR INTO THE 35-45KT RANGE. THIS AMOUNT OF SHEAR COUPLED WITH THE VEERING LOW LEVEL FLOW (RESIDUAL EFFECT OF THE CAD AIR MASS IN THE PIEDMONT) SUGGEST LOW LEVEL HELICITY VALUES NEAR THE FAVORABLE PARAMETERS FOR ROTATING CELLS. HOWEVER... THE LOWER HALF OF THE ATMOSPHERE MAY NOT BE BUOYANT ENOUGH TO GENERATE STORMS OF SUFFICIENT DEPTH AS LOW LEVEL INSTABILITY APPEARS TO BE LACKING. THAT BEING SAID...THE MODEL TREND HAS BEEN TO INCREASE THE INSTABILITY WITH EACH SUCCESSIVE RUN SUCH THAT THE 12Z GFS MUCAPE VALUES REACH 1200-1400 J/KG OVER PORTIONS OF THE PIEDMONT AND COASTAL PLAIN WEDNESDAY AFTERNOON AND MLCAPE 400-600J/KG. IF THE MODEL TREND CONTINUES AND IF PEEKS OF SUN OCCUR LATE WEDNESDAY MORNING-AFTERNOON NEAR OR ADJACENT TO OUR REGION...ESPECIALLY SOUTH OF OUR AREA...THEN THE THREAT FOR SEVERE STORMS WILL INCREASE. PLAN TO HAVE POPS IN THE LIKELY TO CATEGORICAL EARLY WEDNESDAY...THEN HIGH CHANCE-LIKELY CATEGORIES WEDNESDAY AFTERNOON AS PRECIP CHARACTER BECOME MORE CONVECTIVE. HIGH TEMPS DEPENDENT UPON DEGREE OF WARM AIR ADVECTION (SOONER THE BETTER). HAVE MAX TEMPS VARYING FROM THE MID-UPPER 60S NW (WHERE RESIDUAL CAD AIR MASS WILL BE LATE TO ERODE) TO THE MID 70S SE. IF ANY BREAKS IN THE OVERCAST OCCUR (SANDHILLS AND COASTAL PLAIN) THEN MAX TEMPS MAY END UP 3-4 DEGREES WARMER. PRE FRONTAL TROUGH AHEAD OF A COLD FRONT WILL CROSS CENTRAL NC LATE WEDNESDAY EVENING INTO THE OVERNIGHT HOURS. THE PASSAGE OF THIS FEATURE WILL DIMINISH CONVECTIVE THREAT. SHOULD SEE POPS DECREASE IN THE WEST PRIOR TO MIDNIGHT...AND IN THE COASTAL PLAIN BY THE OVERNIGHT HOURS. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 135 PM TUESDAY... THU/THU NIGHT: THE SURFACE FRONT/WIND SHIFT WILL HAVE PUSHED EAST OF THE FORECAST AREA WITH STRONG DRYING AND SINKING AIR EXPECTED ABOVE 850 MB... ALTHOUGH THE TRULY COLDER AND DRIER SURFACE AIR WILL NOT ARRIVE UNTIL THU NIGHT. LOW LEVEL THICKNESSES REMAIN WELL ABOVE NORMAL DURING THE DAY WITH A WESTERLY DOWNSLOPE LOW LEVEL WIND COMPONENT... SO EXPECT ABOVE-NORMAL HIGHS FROM 71-78. ISOLATED SHALLOW SHOWERS ARE POSSIBLE WITH SECONDARY FRONTAL PASSAGE THU NIGHT... BUT WITH EXPECTED VERY LOW COVERAGE AND LOW QPF RESULTING FROM THE FALLING PW... WILL MAINTAIN A DRY FORECAST... ALTHOUGH FORECAST SOUNDINGS SHOW SUFFICIENT MOISTURE AT 850-800 MB ALONG THE FRONTAL ZONE ALOFT TO SUPPORT PARTLY CLOUDY SKIES. LOWS FROM 43 NW TO 51 SE AS THICKNESSES DROP BELOW NORMAL. FRI-TUE: DRY WITH PLENTY OF SUNSHINE FRI/SAT. SURFACE HIGH PRESSURE WILL BUILD OVER THE OH VALLEY FRI... PUSHING TO THE MIDATLANTIC REGION BY SAT AND OFF THE COAST SAT NIGHT. A BAGGY AND POSITIVELY TILTED MID LEVEL TROUGH AXIS WILL PUSH EAST OFF THE COAST FRI AFTERNOON FOLLOWED BY RISING HEIGHTS... A RESULT OF A POTENT LONGWAVE TROUGH FROM THE CENTRAL PLAINS TO THE DESERT SW AND NRN MEXICO FORCING DOWNSTREAM RIDGING OVER FL AND THE SE STATES. CLOUDS SHOULD INCREASE OVER NC STARTING LATE SAT AS THE SW TROUGH HEADS EASTWARD... INCREASING THE SWRLY STEERING FLOW AND PASSAGE OF PERTURBATIONS FROM THE WRN GULF INTO THE SRN APPALACHIANS. THE GFS IS A BIT WEAKER AND OVER 12 HRS FASTER THAN THE ECMWF IN LIFTING THIS MID LEVEL LOW TO THE E THEN NE THROUGH THE MID MISS VALLEY INTO THE OH VALLEY. THE OP ECMWF APPEARS TO HAVE BETTER AGREEMENT WITH ITS ENS MEAN THAN THE GFS... AND THE GEFS MEAN ACTUALLY MORE RESEMBLES THE OP ECMWF THAN THE GFS. WITH A LEAN TOWARD THE ECMWF...WILL GO WITH THICKENING CLOUD COVER SUN BUT HOLD OFF ON CHANCE POPS UNTIL SUN NIGHT... LIKELY LASTING INTO MON/TUE (WITH A DROPOFF IN CONFIDENCE) WITH EXPECTATIONS OF A STEADY STREAM OF ATLANTIC AND GULF MOISTURE IN THE LOW AND MID LEVELS... AND SURFACE FRONTAL ZONE APPROACHING FROM THE NORTH AND WEST. THICKNESSES SHOULD START OFF BELOW NORMAL SAT AND RISE ABOVE NORMAL BY LATE SUN... HOLDING ABOVE NORMAL MON/TUE SOUTHEAST OF THE FRONTAL ZONE. -GIH && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 152 PM TUESDAY... VERY HIGH PROBABILITY THAT LIFR/IFR CONDITIONS WILL PREVAIL ACROSS CENTRAL NC THROUGH WEDNESDAY MORNING AS A STOUT LOW LEVEL EASTERLY FLOW PUMPS MOIST AIR INTO THE REGION. A SERIES OF UPPER LEVEL DISTURBANCES WILL CAUSE PERIODS OF LIGHT-MODERATE RAIN WELL INTO THE OVERNIGHT HOURS WITH THE RAIN BECOMING MORE SHOWERY IN CHARACTER...ESPECIALLY ACROSS THE SANDHILLS AND COASTAL PLAIN...BY EARLY WEDNESDAY. A NELY SFC FLOW WILL QUICKLY VEER TO A SELY FLOW JUST ABOVE THE SURFACE AND INCREASE CLOSE TO 40KTS. THIS WILL RESULT IN MARGINAL LOW LEVEL WIND SHEAR CONDITIONS. THIS CONDITION EXPECTED TO BE GREATEST AND PERSIST THE LONGEST IN VICINITY OF THE TRIAD TAF SITES. THE ATMOSPHERE IS EXPECTED TO BECOME CONDITIONALLY UNSTABLE WEDNESDAY-WEDNESDAY AHEAD OF A COLD FRONT. THIS SET-UP SHOULD INITIATE AND SUSTAIN BROKEN BANDS OF CONVECTION OVER CENTRAL NC FROM MID-LATE MORNING THROUGH THE EVENING HOURS. A FEW STORMS WILL HAVE THE POTENTIAL TO BECOME SEVERE...POSSIBLY PRODUCING DAMAGING WIND GUSTS OR AN ISOLATED TORNADO. MAIN LIMITATION TO THE DEVELOPMENT OF SEVERE STORMS WILL BE THE LACK OF SUFFICIENT LOW LEVEL BUOYANCY/INSTABILITY. THE FRONT WILL CROSS CENTRAL NC LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. DRIER AIR WILL ADVECT INTO CENTRAL NC...AIDING TO LIFT AND DISSIPATE THE CLOUD COVERAGE...INITIATING A PERIOD OF VFR CONDITIONS THAT SHOULD PERSIST THROUGH SATURDAY. AN APPROACHING FRONTAL SYSTEM MAY BRING A PERIOD OF ADVERSE WEATHER CONDITIONS TO CENTRAL NC BY LATE SUNDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...26/HARTFIELD NEAR TERM...WSS/MLM SHORT TERM...WSS LONG TERM...HARTFIELD AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
315 PM EDT TUE OCT 27 2015 .SYNOPSIS... INTERMITTENT RAIN WILL CONTINUE ACROSS THE CAROLINAS THROUGH THIS EVENING AS LOW PRESSURE OVER THE LOWER MISSISSIPPI VALLEY MOVES SLOWLY NORTH. A WARM FRONT WILL LIFT NORTH LATE TONIGHT WITH THUNDERSTORMS POSSIBLE ON WEDNESDAY. DRYING WILL OCCUR EARLY THURSDAY FOLLOWED BY A COLD FRONT LATE IN THE DAY. DRY HIGH PRESSURE WILL FOLLOW FOR FRIDAY AND THE UPCOMING WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 2 PM TUESDAY...RADAR INDICATING AREAS OF LIGHT RAIN WITH A FEW POCKETS OF SLIGHTLY HEAVIER RAIN ACROSS THE AREA. THE HEAVIEST RAIN EARLY THIS AFTERNOON WAS OVER THE TIP OF CAPE FEAR WHERE STRONG ON SHORE WINDS WERE PUSHING SOME MORE CONVECTIVE TYPE PCP TOWARD THE COAST...THEN MOVING ON SHORE AS LIGHT TO MODERATE RAIN. CLOUDY...COOL AND DAMP WEATHER WILL PERSIST WITH PERIODS OF RAIN THROUGH THIS AFTERNOON. FOR THE MOST PART...THE HIGH PRESSURE WEDGE AND EVAPORATIVE COOLING WERE KEEPING TEMPERATURES JUST BELOW 60 WEST OF I95 AND INTO THE MID 60S ALONG THE COAST. HIGH PRESSURE WEDGE EVIDENT WITH N-NE WINDS AT THE SURFACE. VAD WIND PROFILES SHOWING STRONG EASTERLY FLOW UP TO 35 KTS THROUGH THE LOWER LEVELS VEERING TO MORE SOUTHERLY IN THE MID TO UPPER LEVELS. THIS WILL KEEP PERSISTENT MOIST HELP WITH ISENTROPIC LIFT OVER INLAND AREAS WHILE BETTER CONVERGENCE AND CONVECTIVE TYPE PCP HOLDS OFF SHORE. OVERALL A STRONG MOISTURE TRANSPORT OFF THE ATLANTIC WILL PERSIST THROUGH TONIGHT...WITH A CONTINUED VEERING PROFILE OF LOW- LEVEL WINDS WORKING DOWN TO THE SFC EVENTUALLY OVERNIGHT AS WARM FRONT MOVES INLAND AND NORTH. THE BULK OF RAINFALL WILL REMAIN STRATIFORM IN NATURE TODAY...TRANSITIONING TO A SHOWERY CHARACTER TONIGHT AS A WARM FRONT SPREADS MILD AIR INLAND. EXPECT SOME SPOTS TO SEE QPF TOTALS UP TO 1.25 INCHES UP THROUGH DAYBREAK WEDNESDAY. MIN TEMPS WILL BE A BIT TRICKY AS WARM FRONT WORKS ITS WAY INLAND LATE TONIGHT...BUT TEMPS WILL NOT SHOW MUCH MOVEMENT INTO TONIGHT BUT RATHER THAN DROP TOO MUCH THERE WILL BE A SLIGHT RISE AS WARM FRONT MOVES INLAND AND NORTH OVERNIGHT. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...H5 LOW DROPPING TOWARD THE MIDWEST WEDNESDAY WILL DIRECT A SHORT WAVE TOWARD THE CAROLINAS BY WEDNESDAY NIGHT ALLOWING A SURFACE TROUGH/WEAK FRONT TO MOVE BY. THE TROUGH/WEAK FRONT WILL EFFECTIVELY PUSH THE DEEPER MOISTURE/HIGHER PRECIPITABLE WATER OFF THE COAST DURING THAT SAME TIME FRAME BRINGING RAIN CHANCES TO AN END. IN THE MEANTIME...MARGINAL SURFACE BASED INSTABILITY AND CAPE AROUND 1000 J/KG WILL SUPPORT A FEW TSTMS WEDNESDAY...WITH AN ISOLATED SVR THREAT. THE PRECIPITABLE WATER ATTEMPTS TO RECOVER AHEAD OF ANOTHER WEAK COLD FRONT THURSDAY BUT WITH DOWNSLOPE FLOW AND INCREASED STABILITY NO PLAN TO INCLUDE POPS AT THIS TIME FOR THURSDAY. A CONTINUATION OF ABOVE NORMAL TEMPERATURES IS EXPECTED WEDNESDAY AND THURSDAY WITH COLD AIR ADVECTION LACKING. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...DRY DOWNSLOPING MID LEVEL FLOW ON FRIDAY WHILE HIGH PRESSURE BUILDS IN FROM POINTS NORTH AND WEST. ON SATURDAY THE RIDGE AXIS CROSSES THE AREA BOTH SURFACE AND ALOFT. THE PATTERN IS QUITE PROGRESSIVE SO THE AFOREMENTIONED FEATURES END UP OFF THE COAST ON SUNDAY. THIS WILL SET THE STAGE FOR MOISTURE AND TO A LESSER EXTENT WARM ADVECTION. THE OFFSHORE RIDGE APPEARS TO HAVE SOME STRENGTH TO IT AS MODELS SHOW THE NEXT POTENT UPPER TROUGH APPROACH FROM THE WEST GETTING SHUNTED NORTHEASTWARD. THIS IS MAKING FOR A LITTLE UNCERTAINTY REGARDING THE TIMING OF THE RAIN CHANCES BROUGHT BY THIS SYSTEM AS TYPICALLY IN SUCH A SETUP GUIDANCE IS TOO FAST. FOR NOW THE BEST BET STILL LOOKS LIKE MONDAY. BY TUESDAY THE TROUGH EVEN LOSES MOST OF ITS IDENTITY AS VERY BROAD RIDGING DEVELOPS ACROSS MUCH OF THE EASTERN U.S. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...WEDGE STILL HANGING IN THERE AND EXPECTED TO DO SO FOR MUCH OF THE EVENING. NORTHEAST WINDS WILL SLOWLY VEER TO THE EAST THIS EVENING...BECOMING SOUTHEAST DURING THE OVERNIGHT HOURS. AM LEANING TOWARDS THE HRRR IN THE NEAR TERM AS IT HAS BEEN PRETTY CONSISTENT IN BRINGING IN HEAVIER RAIN ALONG THE COAST THIS EVENING...PARTICULARLY AT ILM. OVERNIGHT EXPECT IFR INLAND WITH PREDOMINATELY MVFR ALONG THE COAST...CONFIDENCE IS MODERATE. WEDNESDAY...THINGS BECOME MORE UNSTABLE IN THE WARM SECTOR WITH CONVECTION EXPECTED TO BREAK OUT AT ANY TIME. COULD BE SOME DECENT STORMS IF WE GET SOME GOOD HEATING. GUSTY SOUTHERLY FLOW WITH DEWPOINTS IN THE MID TO UPPER 60S. EXTENDED OUTLOOK...BECOMING VFR WEDNESDAY NIGHT...CONTINUING THROUGH SATURDAY. LOW CONFIDENCE FOR SHOWERS SUNDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 2 PM TUESDAY...A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TONIGHT. SEAS UP TO 6 TO 8 FT WITH WINDS NE UP TO 25 KTS VEERING AROUND SLIGHTLY TO A MORE EASTERLY DIRECTION AND DIMINISHING IN INTENSITY THROUGH THIS AFTERNOON. MOST OF THE WAVE ENERGY WILL BE TIED TO WAVE PERIODS OF 7 TO 8 SECONDS. WINDS WILL DIMINISH AND VEER AROUND FURTHER THROUGH TONIGHT AS A WARM FRONT PUSHES TOWARD THE COAST AND INLAND WITH MAIN FOCUS OF SCA ON SEAS REMAINING HIGH DUE TO ON SHORE PUSH. AS A WARM FRONT MOVES FARTHER INLAND THROUGH TONIGHT...WINDS WILL COME AROUND TO THE E TO SE. INCREASED CONVERGENCE/SHEAR ALONG THIS BOUNDARY WILL PRODUCE ISOLATED TSTMS. SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST THROUGH THE NEAR TERM AND BEYOND. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...SOUTHERLY FETCH WEDNESDAY WILL TURN TO AN OFFSHORE DIRECTION LATE WEDNESDAY NIGHT IN THE WAKE OF A SURFACE TROUGH/WEAK FRONT. COLD AIR ADVECTION IS LACKING BEHIND THE TROUGH/FRONT AND EXPECT THE FLOW TO BACK TO A WEST TO SOUTHWEST DIRECTION BY THURSDAY NIGHT WITH ANOTHER WEAK FRONT ADVANCING ACROSS THE WATERS VERY LATE. SEAS WILL BE HIGHEST ACROSS THE AREA WATERS DURING WEDNESDAY...THEN THE RANGE WILL INCREASE FROM NEARSHORE TO THE OUTER COASTAL WATERS AS THE FLOW BECOMES OFFSHORE. SMALL CRAFT ADVISORY WILL CONTINUE THROUGH WEDNESDAY. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...WINDS VEERING FROM NORTHERLY TO NORTHEASTERLY AS FRIDAY PROGRESSES WITH HIGH PRESSURE MOVING EAST AND PASSING US BY WELL TO THE NORTH. THESE NORTHEASTERLY WINDS WILL CONTINUE INTO SATURDAY AND SLACKEN IN SPEED DUE TO THE HIGH EXTENDING A RIDGE AXIS DOWN INTO THE CAROLINAS AND ADJACENT WATERS EASING THE PRESSURE GRADIENT. FURTHER VEERING TO SE OR PERHAPS EVEN SW THEN SLATED FOR SUNDAY AS THE HIGH PROGRESSES OFFSHORE AND PERHAPS A WEAK PIEDMONT TROUGH DEVELOPS. && .TIDES/COASTAL FLOODING... AS OF 3 PM TUESDAY...COASTAL FLOOD ADVISORY IN EFFECT FOR LOWER CAPE FEAR RIVER AND ALL BEACHES. MINOR COASTAL FLOODING POSSIBLE AGAIN DURING HIGH TIDE THIS EVENING WHICH WILL OCCUR AROUND 8PM THIS EVENING ALONG THE BEACHES AND CLOSE TO 1030 PM FOR DOWNTOWN WILMINGTON. THE GREATEST TIDE DEPARTURE OCCURS THE DAY AFTER FULL MOON AND WITH SLIGHTLY HIGHER ASTRONOMICAL TIDES COUPLED WITH ONSHORE FLOW HAVE OPTED TO RAISE AS COASTAL FLOOD WATCH FOR GEORGETOWN...HORRY... BRUNSWICK.... NEW HANOVER AND PENDER COUNTIES FOR WEDNESDAY MORNING. A COASTAL FLOOD ADVISORY SHOULD COVER THE IMPACTS ALONG THE LOWER CAPE FEAR RIVER TOMORROW MORNING. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...COASTAL FLOOD WATCH WEDNESDAY MORNING FOR SCZ054-056. NC...COASTAL FLOOD WATCH WEDNESDAY MORNING FOR NCZ106-108-110. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR AMZ254-256. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT WEDNESDAY NIGHT FOR AMZ250-252. && $$ NEAR TERM...RGZ SHORT TERM...SRP LONG TERM...MBB AVIATION...DL/RGZ TIDES/COASTAL FLOODING...SRP/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
231 PM EDT TUE OCT 27 2015 .SYNOPSIS... INTERMITTENT RAIN WILL CONTINUE ACROSS THE CAROLINAS THROUGH THIS EVENING AS LOW PRESSURE OVER THE GULF COAST MOVES SLOWLY NORTH. A WARM FRONT WILL LIFT NORTH LATE TONIGHT WITH THUNDERSTORMS POSSIBLE ON WEDNESDAY. DRYING WILL OCCUR EARLY THURSDAY FOLLOWED BY A COLD FRONT LATE IN THE DAY. DRY HIGH PRESSURE WILL FOLLOW FOR FRIDAY AND THE UPCOMING WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 200 PM TUESDAY...RADAR INDICATING AREAS OF LIGHT RAIN WITH A FEW POCKETS OF SLIGHTLY HEAVIER RAIN ACROSS THE AREA. THE HEAVIEST RAIN EARLY THIS AFTERNOON WAS OVER THE TIP OF CAPE FEAR WHERE STRONG ON SHORE WINDS WERE PUSHING SOME MORE CONVECTIVE TYPE PCP TOWARD THE COAST...THEN MOVING ON SHORE AS LIGHT TO MODERATE RAIN. CLOUDY...COOL AND DAMP WEATHER WILL PERSIST WITH PERIODS OF RAIN THROUGH THIS AFTERNOON. FOR THE MOST PART...THE HIGH PRESSURE WEDGE AND EVAPORATIVE COOLING WERE KEEPING TEMPERATURES JUST BELOW 60 WEST OF I95 AND INTO THE MID 60S ALONG THE COAST. HIGH PRESSURE WEDGE EVIDENT WITH N-NE WINDS AT THE SURFACE. VAD WIND PROFILES SHOWING STRONG EASTERLY FLOW UP TO 35 KTS THROUGH THE LOWER LEVELS VEERING TO MORE SOUTHERLY IN THE MID TO UPPER LEVELS. THIS WILL KEEP PERSISTENT MOIST HELP WITH ISENTROPIC LIFT OVER INLAND AREAS WHILE BETTER CONVERGENCE AND CONVECTIVE TYPE PCP HOLDS OFF SHORE. OVERALL A STRONG MOISTURE TRANSPORT OFF THE ATLANTIC WILL PERSIST THROUGH TONIGHT...WITH A CONTINUED VEERING PROFILE OF LOW- LEVEL WINDS WORKING DOWN TO THE SFC EVENTUALLY OVERNIGHT AS WARM FRONT MOVES INLAND AND NORTH. THE BULK OF RAINFALL WILL REMAIN STRATIFORM IN NATURE TODAY...TRANSITIONING TO A SHOWERY CHARACTER TONIGHT AS A WARM FRONT SPREADS MILD AIR INLAND. EXPECT SOME SPOTS TO SEE QPF TOTALS UP TO 1.25 INCHES UP THROUGH DAYBREAK WEDNESDAY. MIN TEMPS WILL BE A BIT TRICKY AS WARM FRONT WORKS ITS WAY INLAND LATE TONIGHT...BUT TEMPS WILL NOT SHOW MUCH MOVEMENT INTO TONIGHT BUT RATHER THAN DROP TOO MUCH THERE WILL BE A SLIGHT RISE AS WARM FRONT MOVES INLAND AND NORTH OVERNIGHT. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM TUESDAY...ACTIVE WEATHER WEDNESDAY BEHIND A WARM FRONT...BEFORE DRYING OCCURS THURSDAY. THE SHORT TERM WILL FEATURE ABOVE NORMAL TEMPERATURES. WARM FRONT WILL BE LIFTING NORTH...OR POSSIBLY COMPLETELY THROUGH...THE CWA TO START THE PERIOD. AS THIS FRONT LIFTS NORTHWARD...DRAPED FROM A LARGE CYCLONE ACROSS THE GREAT LAKES...STRONG WAA WILL DEVELOP. FORECAST SOUNDINGS SUGGEST A LLJ OF 30-40 KTS AT THE TOP OF THE PBL WEDNESDAY AFTN...THIS DRIVING BOTH THE WARM ADVECTION AND POTENTIAL CONVECTION DURING THE DAY. ALTHOUGH FORCING IS SOMEWHAT LIMITED DURING WEDNESDAY...SCATTERED TO WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED IN AN ENVIRONMENT CHARACTERIZED BY PWATS OF 1.75 INCHES AND MLCAPE OF 500-1000 J/KG. LAPSE RATES ARE NOT TREMENDOUSLY STEEP...AND DRY AIR ABOVE 600MB WILL ALSO BE A LIMITING FACTOR...BUT THUNDERSTORMS WITH GUSTY WINDS ARE LIKELY ACROSS THE AREA. THESE STRONG WINDS COULD POTENTIALLY MIX DOWN AS AN ISOLATED DAMAGING WIND GUST AS WELL...AND SPC HAS PLACED THE AREA IN A MARGINAL RISK IN THE SWODY2. POTENT VORT LOBE SWINGS ACROSS THE AREA LATE WEDNESDAY NIGHT AND INTO THURSDAY...CAUSING RAPID DRYING OF THE COLUMN AS EVIDENCED BY PWATS FALLING TO 0.75 INCHES OR LESS. THE COLD FRONT AND ASSOCIATED COLD ADVECTION LAGS THE UPPER VORT HOWEVER...SO THURSDAY WILL LIKELY BE A WARM AND BECOMING MOSTLY SUNNY DAY BEFORE THE FROPA OCCURS LATE. TEMPS WEDNESDAY WILL BE WARM EVEN WITH CLOUDS AND CONVECTION ON THE STRONG WAA...RISING INTO THE UPPER 70S OR EVEN LOW 80S SOUTHERN ZONES...MID 70S ACROSS THE NORTH. MID TO UPPER 70S WILL AGAIN BE EXPECTED ON THURSDAY. MINS WEDNESDAY NIGHT WILL BE A SOLID 10-15 DEGREES ABOVE NORMAL...DROPPING ONLY TO 60-65...COOLEST INLAND...WITH MORE SEASONABLE LOWS EXPECTED THURSDAY NIGHT AFTER COLD FROPA. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 330 AM TUESDAY...BEAUTIFUL FALL WEATHER FOR THE FIRST HALF OF THE EXTENDED BEHIND A COLD FRONT WHICH WILL BE OFFSHORE FRIDAY MORNING. STRONG CAA WILL KEEP TEMPS SLIGHTLY BELOW CLIMO BOTH FRIDAY AND SATURDAY...BUT WITH ABUNDANT SUNSHINE IN AN EXCEEDINGLY DRY COLUMN...IT WILL BE NEARLY PERFECT FOR THE TIME OF YEAR. HALLOWEEN FESTIVITIES SATURDAY NIGHT WILL BE COOL BUT DRY...WITH ONLY SOME MID- LEVEL CLOUDINESS BEGINNING TO INCREASE LATE SAT NIGHT. GUIDANCE HAS SLOWED PROGRESS OF A STORM SYSTEM AND ITS COLD FRONT FOR THE END OF THE PERIOD...AND NOW MUCH OF SUNDAY APPEARS TO BE DRY AND WARMER AS RETURN FLOW DEVELOPS...BUT WITH INCREASED CLOUDINESS. A COLD FRONT WILL APPROACH ON MONDAY WITH INCREASING SHOWER AND TSTM CHANCES...BUT TEMPS ARE FORECAST TO REMAIN ABOVE CLIMO THROUGH THE END OF THE EXTENDED. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...WEDGE STILL HANGING IN THERE AND EXPECTED TO DO SO FOR MUCH OF THE EVENING. NORTHEAST WINDS WILL SLOWLY VEER TO THE EAST THIS EVENING...BECOMING SOUTHEAST DURING THE OVERNIGHT HOURS. AM LEANING TOWARDS THE HRRR IN THE NEAR TERM AS IT HAS BEEN PRETTY CONSISTENT IN BRINGING IN HEAVIER RAIN ALONG THE COAST THIS EVENING...PARTICULARLY AT ILM. OVERNIGHT EXPECT IFR INLAND WITH PREDOMINATELY MVFR ALONG THE COAST...CONFIDENCE IS MODERATE. WEDNESDAY...THINGS BECOME MORE UNSTABLE IN THE WARM SECTOR WITH CONVECTION EXPECTED TO BREAK OUT AT ANY TIME. COULD BE SOME DECENT STORMS IF WE GET SOME GOOD HEATING. GUSTY SOUTHERLY FLOW WITH DEWPOINTS IN THE MID TO UPPER 60S. EXTENDED OUTLOOK...BECOMING VFR WEDNESDAY NIGHT...CONTINUING THROUGH SATURDAY. LOW CONFIDENCE FOR SHOWERS SUNDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 200 PM TUESDAY...A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TONIGHT. SEAS UP TO 6 TO 8 FT WITH WINDS NE UP TO 25 KTS VEERING AROUND SLIGHTLY TO A MORE EASTERLY DIRECTION AND DIMINISHING IN INTENSITY THROUGH THIS AFTERNOON. MOST OF THE WAVE ENERGY WILL BE TIED TO WAVE PERIODS OF 7 TO 8 SECONDS. WINDS WILL DIMINISH AND VEER AROUND FURTHER THROUGH TONIGHT AS A WARM FRONT PUSHES TOWARD THE COAST AND INLAND WITH MAIN FOCUS OF SCA ON SEAS REMAINING HIGH DUE TO ON SHORE PUSH. AS A WARM FRONT MOVES FARTHER INLAND THROUGH TONIGHT...WINDS WILL COME AROUND TO THE E TO SE. INCREASED CONVERGENCE/SHEAR ALONG THIS BOUNDARY WILL PRODUCE ISOLATED TSTMS. SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST THROUGH THE NEAR TERM AND BEYOND. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 330 AM TUESDAY...WARM FRONT WILL BE NORTH OF THE WATERS TO START WEDNESDAY...AND GUSTY SOUTHERLY WINDS WILL BE ONGOING. WINDS OF 15-20 KTS WITH GUSTS UP TO 30 KTS WILL BE COMMON THROUGH WEDNESDAY...AND AN SCA WILL CARRYOVER FROM TUESDAY ACROSS ALL WATERS FOR 4-7 FT SEAS. AS THE WARM FRONT PROGRESSES FARTHER NORTH THROUGH WEDNESDAY...THE GRADIENT WILL RELAX...AND WINDS SPEEDS WILL EASE TO 10-15 KTS WEDNESDAY NIGHT WHILE ALSO SHIFTING MORE TO THE SW. THIS WILL BRING AN END TO THE ADVISORY AND WAVE HEIGHTS WILL BE 3-5 FT THURSDAY MORNING. W/SW WINDS OF 10-15 KTS WILL THEN PERSIST MUCH OF THURSDAY BEFORE A COLD FRONT DROPS SE ACROSS THE WATERS LATE...TURNING WINDS TO THE NW AT 10-15 KTS AND PUSHING THE HIGHEST SEAS EVEN FURTHER FROM SHORE LEAVING 2-4 FT WAVE HEIGHTS ACROSS THE COASTAL WATERS. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 330 AM TUESDAY...COLD FRONT WILL BE OFFSHORE TO START THE PERIOD AS HIGH PRESSURE BUILDS ACROSS THE REGION. WINDS INITIALLY WILL BE NW AROUND 15 KTS AS THE GRADIENT REMAINS PINCHED BEHIND THE FRONT...BUT WILL EASE AS THE HIGH MOVES OVERHEAD AND THEN OFFSHORE INTO SUNDAY. WIND SPEEDS WILL GENERALLY BE 10 KTS FRIDAY AFTN THROUGH THE END OF THE PERIOD...WITH DIRECTION VEERING FROM NW EARLY TO EAST LATE. SEAS OF 2-4 FT EARLY FRIDAY WILL DROP THROUGH THE PERIOD...BECOMING AROUND 2 FT SATURDAY. && .TIDES/COASTAL FLOODING... AS OF 200 PM TUESDAY...ALL RIVER AND WATER LEVELS HAVE DROPPED BELOW ADVISORY THRESHOLDS...BUT COASTAL FLOOD ADVISORIES WILL BE REQUIRED FOR SUCCESSIVE HIGH TIDES UP AND DOWN THE IMMEDIATE COAST AND FOR THE LOWER CAPE FEAR RIVER THROUGH MID WEEK DUE TO STRONG ONSHORE WINDS AND HIGH ASTRONOMICAL TIDES. THE FULL MOON IS TODAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR AMZ254-256. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT WEDNESDAY NIGHT FOR AMZ250-252. && $$ NEAR TERM...RGZ SHORT TERM...JDW/SRP LONG TERM...JDW AVIATION...DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1220 PM CDT TUE OCT 27 2015 .UPDATE... ISSUED AT 1207 PM CDT TUE OCT 27 2015 LATEST RADARS SHOW A BAND OF SHOWERS MOVING THROUGH THE JAMES RIVER VALLEY AND SCATTERED SHOWERS NORTH CENTRAL. EARLIER LIGHTNING SEEMS TO HAVE ENDED EAST. COLD FRONT WILL MOVE THROUGH THIS AFTERNOON. CURRENT FORECAST LOOKS GOOD. UPDATE ISSUED AT 849 AM CDT TUE OCT 27 2015 A LOW PRESSURE AREA ACROSS WESTERN SOUTH DAKOTA AT 830 AM CDT HAS A WARM FRONTAL BOUNDARY EXTENDING NORTHEAST ACROSS SOUTHEAST NORTH DAKOTA. AREA OF RAIN ACROSS NORTH CENTRAL TRAILED OFF TO A NARROW BAND OF SHOWERS BETWEEN THE MISSOURI AND JAMES RIVER VALLEYS NORTH OF THE WARM FRONT. LOW LEVEL WARM AIR WILL MOVE NORTH INTO SOUTHEAST NORTH DAKOTA TODAY. CURRENT FORECAST LOOKS OK. MAY HAVE TO RAISE MAX TEMPS SOUTHEAST...BETWEEN WISHEK AND OAKES..IN THE WARM SECTOR OF THE SYSTEM. UPDATE ISSUED AT 637 AM CDT TUE OCT 27 2015 OVERALL...THE FORECAST REMAINS ON TRACK AS RAIN SHOWERS ACROSS CENTRAL NORTH DAKOTA CONTINUE TO PROPAGATE NORTH-NORTHEAST IN ASSOCIATION WITH AN UPPER LEVEL JET STREAK THIS MORNING. ONGOING FORECAST BLENDED TO OBSERVED TRENDS AND A TIME LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 327 AM CDT TUE OCT 27 2015 CLOUDS AND CHANCES OF RAIN TODAY...TURNING COLDER TONIGHT WITH LIGHT RAIN OR FLURRIES POSSIBLE. CURRENTLY...AN UPPER LEVEL LOW PRESSURE SYSTEM EXTENDED FROM THE ROCKIES INTO THE WESTERN PLAINS...WITH EMBEDDED SHORTWAVES/LOWS WITHIN THE MAIN TROUGH CIRCULATING CYCLONICALLY THROUGH THE TROUGH. ONE OF THE CIRCULATION CENTERS WAS LOCATED OVER NORTHWESTERN NORTH DAKOTA/NORTHEASTERN MONTANA...WITH AN AREA OF LIGHT TO MODERATE RAIN EXTENDING FROM NORTHEASTERN MONTANA ACROSS NORTHERN NORTH DAKOTA. THIS AREA OF RAIN CONTINUED TO MOVE NORTHWARD. ANOTHER CIRCULATION CENTER WAS OVER SOUTH CENTRAL NORTH DAKOTA...AND ASSOCIATED WITH ANOTHER AREA OF RAIN FROM HETTINGER AND FORT YATES NORTHWARD TO MORTON AND BURLEIGH COUNTIES. AS THE CIRCULATION CENTERS LIFT NORTH/NORTHEASTWARD ACROSS THE REGION THE AREA OF RAIN SHOULD CONTINUE LIFTING NORTHWARD THROUGH THE MORNING HOURS. THUS THE RAIN SHOULD BE ENDING FROM SOUTH TO NORTH THROUGH THE MORNING HOURS. THEN THIS AFTERNOON THE UPPER LEVEL TROUGH AXIS ENTERS WESTERN NORTH DAKOTA AND ARRIVES IN CENTRAL NORTH DAKOTA BY EVENING. MEANWHILE AT THE SURFACE...A TROUGH OF LOW PRESSURE OVER THE FRONT RANGE EARLY THIS MORNING IS PROGGED TO MOVE EASTWARD IN ASSOCIATION WITH THE UPPER LEVEL TROUGH AXIS. BY THIS EVENING THE SURFACE TROUGH IS PROGGED TO BE IN THE DEVILS LAKE/JAMES RIVER BASINS. THIS WILL KEEP THE CHANCES OF RAIN IN THE FORECAST MAINLY OVER NORTHERN NORTH DAKOTA THIS AFTERNOON. WE WILL SEE YET ANOTHER - STRONGER - UPPER LEVEL SHORTWAVE DIVE SOUTHEAST OUT OF ALBERTA TODAY AND APPROACH NORTHWESTERN NORTH DAKOTA LATER THIS AFTERNOON AS THIS SHORTWAVE MERGES WITH THE AFOREMENTIONED UPPER LEVEL TROUGH. THIS WILL DEEPEN/INTENSIFY THE SYSTEM AS IT MOVES SOUTHEAST ACROSS NORTH DAKOTA TONIGHT AND WEDNESDAY. THIS WILL RESULT IN A BLAST OF COLDER AIR PUSHING INTO THE STATE BEHIND GUSTY NORTHWEST WINDS THAT ARE EXPECTED TO DEVELOP. AFTER TEMPERATURES IN THE UPPER 30S AND LOWER 40S THIS MORNING...AND HIGHS TODAY IN THE 45 TO 55 RANGE...THE COLD AIR INTRUSION SHOULD RESULT IN LOWS TUESDAY NIGHT FROM THE MID 20S IN THE WEST TO LOWER 30S IN THE JAMES RIVER VALLEY. CHANCES OF PRECIPITATION WILL REMAIN IN THE FORECAST TONIGHT...AND CHANCES OF RAIN WILL BECOME CHANCES OF SNOW FROM WEST TO EAST DURING THE EVENING HOURS. LIGHT PRECIP AMOUNTS WILL KEEP ANY SNOW FROM ACCUMULATING...EXCEPT PERHAPS SOME LIGHT ACCUMULATIONS IN THE TURTLE MOUNTAINS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 327 AM CDT TUE OCT 27 2015 A COOL AND WINDY WEDNESDAY HIGHLIGHTS THE EXTENDED FORECAST. GIVEN GOOD AGREEMENT AMONGST THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES...UTILIZED A BLEND FOR THE PERIOD. THE CURRENT SHORTWAVE ACROSS NORTHERN ALBERTA AND SASKATCHEWAN TUESDAY MORNING IS FORECAST TO PROPAGATE SOUTHEAST INTO THE EASTERN DAKOTAS WEDNESDAY MORNING AND DEEPEN. THE ASSOCIATED SURFACE COLD FRONT FROM THE SHORT TERM WILL ALREADY HAVE PROPAGATED THROUGH WESTERN AND CENTRAL NORTH DAKOTA...WITH A WINDY AND COOL POST FRONTAL DAY EXPECTED. 0.5 KM WINDS OF 35-40 KTS ARE FORECAST IN A TIGHT PRESSURE GRADIENT ON THE BACKSIDE OF CYCLOGENESIS ACROSS THE GREAT LAKES...SUPPORTING NEAR ADVISORY LEVEL GUSTS ACROSS MUCH OF THE AREA. HOWEVER...GIVEN THE MARGINAL VALUES...WILL NOT ISSUE ANY WIND HEADLINES AT THIS TIME. A FEW WRAP AROUND RAIN SHOWERS...POTENTIALLY MIXED WITH SNOW IN THE MORNING...ARE POSSIBLE EAST OF US HIGHWAY 83 WEDNESDAY. AFTER WEDNESDAY...A POTENTIAL WARM UP INTO THE 50S AND LOWER 60S IS FORECAST FOR THE WEEKEND AS THE UPPER LEVEL PATTERN IS EXPECTED TO SETTLE BACK TO NEAR ZONAL. HOWEVER...EARLY NEXT WEEK A LONGWAVE WESTERN CONUS TROUGH IS POSSIBLE...WHICH WOULD SIGNAL A POSSIBLE RETURN TO ACTIVE WEATHER ACROSS THE NORTHERN PLAINS MID TO LATE NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1207 PM CDT TUE OCT 27 2015 AT NOON CDT...A COLD FRONT EXTENDED ACROSS NORTHEAST MONTANA AND WILL MOVE EAST THIS AFTERNOON. MVFR CONDITIONS WILL PREVAIL ACROSS KISN-KDIK-KBIS-KMOT. VFR AT KJMS WILL BECOME MVFR AFTER 06Z. GUSTY NORTHWEST 20 TO 35 KTS WINDS ARE EXPECTED WEDNESDAY....WITH THE STRONGEST WINDS KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...JV LONG TERM...AYD AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1224 PM CDT TUE OCT 27 2015 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY ISSUED AT 342 AM CDT TUE OCT 27 2015 FOCUS IN THE SHORT TERM WILL CONTINUE TO BE ON THE TIMING AND DURATION OF STRATIFORM RAIN SHIELD FORECAST TO EVOLVE OVER THE FORECAST AREA...AS NORTHERN AND SOUTHERN STREAM ENERGY CONGEAL OVER THE UPPER MIDWEST AND GREAT LAKES REGION TONIGHT AND WEDNESDAY. IN THE MEANTIME...WEAK MID-LEVEL FRONTOGENETIC FORCING IN CONCERT WITH SUBTLE SHORTWAVE IMPULSES AND SOMEWHAT DEEPER MOISTURE CONTINUES TO GENERATE A PESKY NARROW BAND OF VERY LIGHT RAIN OR SPRINKLES CURRENTLY EXTENDING FROM NORTHCENTRAL WISCONSIN TO NORTHERN MINNESOTA. RAP SEEMS TO HAVE CAPTURED THE BASIC EVOLUTION OF THIS VERY LIGHT PRECIPITATION BAND AND CARRIES IT NORTHWARD INTO UPPER MICHIGAN BY 14 OR 15Z THIS MORNING WHICH SEEMS REASONABLE BASED ON CURRENT TRENDS. NOT GOING TO INCLUDE MENTION OF ANY POPS THIS MORNING FOR THE FAR NORTH AS MEASURABLE AMOUNTS ARE DUBIOUS AT THIS POINT. OTHERWISE...FOR THE REMAINDER OF TODAY EXPECT LOTS OF MID-LEVEL CLOUDINESS WITHIN BROAD AREA OF WEAK ISENTROPIC LIFT. ACROSS NORTHERN WISCONSIN...EXPECT MORE IN THE WAY OF LOW CLOUDS AND SOME PATCHY FOG FOR AT LEAST A COUPLE MORE HOURS EARLY THIS MORNING. DESPITE LOTS OF CLOUDS...TEMPERATURES WILL REMAIN WELL ABOVE NORMAL FOR LATE OCTOBER WITH READINGS MAINLY IN THE 55 TO 60 DEGREE RANGE. THEN FOCUS SHIFTS TO THIS EVENING AND OVERNIGHT...AS SHORTWAVE ENERGY OVER THE CENTRAL PLAINS GRADUALLY CONGEALS WITH MORE POTENT SHORTWAVE DROPPING OUT OF CANADA. SOMEWHAT SURPRISINGLY...SEEMS TO BE FAIRLY DECENT CONSENSUS AMONG THE MODEL GUIDANCE ON THE OVERALL EVOLUTION OF THIS SYSTEM OVER THE NEXT 24 TO 36 HOURS AS PRIMARY UPPER-LOW DEEPENS OVER WESTCENTRAL MINNESOTA AND SURFACE CYCLOGENESIS RAPIDLY COMMENCES OVER THE UPPER MIDWEST DURING THE DAY ON WEDNESDAY. CONSENSUS OF MODEL GUIDANCE TAKES DEEPENING SURFACE LOW SITUATED NEAR DVN BY 06Z WEDNESDAY...NORTHEAST TO NEAR GRB BY 15Z WEDNESDAY. DURING THIS PERIOD...HUGE SLUG OF DEEP MOISTURE OVER THE SOUTHERN AND CENTRAL MISSISSIPPI WILL ALSO BE RAPIDLY DRAWN NORTHWARD INTO WISCONSIN WEDNESDAY EVENING AS 850 MB SOUTHERLY WINDS INCREASE TO 30 TO 40 KTS. LEADING EDGE OF PRIMARY PRECIPITATION SHIELD SHOULD BEGIN TO IMPACT OUR SOUTHERN TIER OF COUNTIES AROUND 00Z WEDNESDAY...THEN STEADILY SPREAD NORTHWARD OVERNIGHT. INCREASING PRESSURE GRADIENT ON THE NORTH SIDE OF THE DEEPENING SURFACE LOW WILL ALSO LEAD TO INCREASING SOUTHEASTERLY BOUNDARY LAYER WINDS TUESDAY NIGHT INTO EARLY WEDNESDAY. STRONGEST QG FORCING AND DEEP LAYER LIFT EXPECTED TO MOVE ACROSS THE FORECAST AREA ROUGHLY BETWEEN ABOUT 06Z AND 15Z WEDNESDAY...WHEN THE BULK OF THE RAINFALL WILL OCCUR. FORTUNATELY THIS SYSTEM WILL BE RATHER PROGRESSIVE WITH THE BULK OF THE PRECIPITATION MOVING NORTHEAST OF THE FORECAST AREA BY AROUND 00Z THURSDAY AS MID-LEVEL DRY INTRUSION AND STRONG SUBSIDENCE PUSH ACROSS THE SOUTHERN HALF OF WISCONSIN. RAINFALL AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE...WITH STORM TOTAL PRECIPIATION AMOUNTS APPROACHING THREE QUARTER TO PERHAPS AN INCH LOCALLY OVER THE SOUTHWEST PORTION OF THE FORECAST AREA. LOOKS LIKE THE ENTIRE FORECAST AREA SHOULD SEE A DECENT SOAKING RAIN. .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY ISSUED AT 342 AM CDT TUE OCT 27 2015 SIGNIFICANT STORM EXPECTED TO MOVE ACROSS THE REGION WEDNESDAY AND THEN SLOWLY MOVE AWAY FROM THE REGION WEDNESDAY NIGHT AND THURSDAY. SOME SIGNIFICANT DIFFERENCES NOTED IN HOW MUCH COLD AIR GETS WRAPPED INTO THE SYSTEM ACROSS THE NORTH WEDNESDAY NIGHT WHICH WOULD HAVE AN IMPACT ON PRECIPITATION TYPES AND AMOUNT OF SNOW THE FAR NORTH WOULD RECEIVE. GFS IS SLOWER WITH COLDER AIR MOVING INTO THE NORTH...MAINLY LATE EVENING AND OVERNIGHT. THE ECMWF ON THE OTHER HAND WOULD SUGGEST SNOW WOULD START DURING THE EARLY EVENING HOURS AND CONTINUE INTO THURSDAY MORNING. 850MB WINDS WILL BECOME VERY FAVORABLE AT 340 DEGREES FOR LAKE ENHANCEMENT SNOW SHOWERS ACROSS THE NORTH IF THE COLDER AIR MATERIALIZES. LATER SHIFTS WILL NEED TO MONITOR THIS AND MAY NEED ADJUST SNOWFALL TOTALS ACCORDINGLY ONCE MODELS CONVERGE ] ON THE TIMING OF THE COLD AIR. FLURRIES MAY BE SEEN AS FAR SOUTH AS WISCONSIN RAPIDS TO THE FOX VALLEY LATE WEDNESDAY NIGHT BUT NO ACCUMULATION IS EXPECTED IN THIS REGION. GUSTY WESTERLY WINDS OF 30 TO 40 MPH CAN BE EXPECTED WEDNESDAY NIGHT INTO THURSDAY BEHIND THE DEPARTING SYSTEM. INCREASED RAIN CHANCES ACROSS THE AREA DUE TO COLD CYCLONIC FLOW AND WEAK DISTURBANCE MOVING ACROSS THE REGION. DO EXPECT INSTABILITY RAIN SHOWERS...WITH SNOW ACROSS THE NORTH DURING THE MORNING. THE SHOWERS WILL GRADUALLY DIMINISH DURING THE LATE AFTERNOON HOURS. THE NEXT CHANCE OF RAIN WILL OCCUR FRIDAY NIGHT AND SATURDAY AS A COLD FRONT MOVES ACROSS THE STATE. BEYOND THIS PERIOD...NO REAL SIGNIFICANT CHANCES FOR RAIN. MAIN STORY WILL BE THE ABOVE NORMAL TEMPERATURES EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1223 PM CDT TUE OCT 27 2015 AFTER A VFR AFTERNOON OVER THE REGION...ADVERSE FLYING WEATHER WILL QUICKLY OVERSPREAD NE WI THIS EVENING AS A STRENGHTHENING AREA OF LOW PRES MOVES NWD FROM THE MID-MS VALLEY TO THE WRN GREAT LAKES. ABUNDANT GULF MOISTURE WL BE AVAILABLE...THUS MODERATE TO HEAVY RAINFALL IS POSSIBLE DURING THE OVRNGT HOURS. CIGS/VSBYS ARE FCST TO DROP INTO THE MVFR RANGE WHEN THE PCPN BEGINS THIS EVENING AND THEN FALL INTO THE IFR RANGE OVRNGT AS THE RAIN INTENSIFIES. ALONG WITH THE PCPN...GUSTY EAST WINDS AROUND 20 KTS CAN BE EXPECTED FOR MOST OF TNGT. THE SFC LOW IS FCST TO LIFT NORTH AND CONT TO INTENSIFY ON WED...BRINGING ADDITIONAL RAINFALL AND A WIND SHIFT TO THE WEST. IFR CONDITIONS WL PERSIST WED MORNING AND MAY SLOWLY IMPROVE TO THE MVFR RANGE ONCE THE LOW BEGINS TO PULL AWAY IN THE AFTERNOON. THE WEST WINDS ARE ALSO EXPECTED TO GRADUALLY INCREASE WED AFTERNOON WITH GUSTS IN THE 25-30 KT RANGE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ESB LONG TERM......ECKBERG AVIATION.......AK