Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/18/15


AREA FORECAST DISCUSSION
NWS TUCSON AZ
845 PM MST SAT OCT 17 2015 .SYNOPSIS...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TONIGHT FOLLOWED BY LESS COVERAGE OF SHOWERS AND THUNDERSTORMS SUNDAY AND ESPECIALLY MONDAY. A LOW PRESSURE SYSTEM WILL THEN BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY. DRY CONDITIONS WILL RETURN BY NEXT WEEKEND. && .DISCUSSION...WATER VAPOR IMAGERY...18/00Z UPPER-AIR PLOTS AND THE MOST RECENT MODEL DATA SHOW AN UPPER LOW SPINNING OFF THE NORTHERN CALIFORNIA COAST WITH THE ASSOCIATED TROUGH AXIS EXTENDING SOUTH JUST OFF THE CALIFORNIA COAST. MEANWHILE...A WEAK DISTURBANCE MOVING UP FROM THE SOUTHWEST HAS HELPED TO TRIGGER SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE INTERFACE BETWEEN VERY DRY MID LEVEL AIR TO THE SOUTHWEST AND MORE MOIST AIR TO THE EAST/NORTHEAST. IR IMAGERY SHOWS THE LINGERING COMPLEX OVER THE CENTRAL PORTION OF MY FORECAST AREA...INCLUDING PARTS OF THE TUCSON METRO. RADAR MOSAIC SHOWS SCATTERED SHOWERS AND THUNDERSTORMS THAT EXTEND FROM NEAR KEARNY IN EASTERN PINAL COUNTY...TO ORACLE JUNCTION...CATALINA AND INTO PARTS OF THE TUCSON METRO AND SOUTH TOWARD GREEN VALLEY AND NOGALES. THESE SHOWERS AND STORMS WILL CONTINUE TO MOVE TO THE NORTHEAST/EAST BUT BOTH THE U OF A WRF/NAM AND HRRR SEEM TO SUGGEST THAT AS THEY AREA OF SHOWERS/STORMS MOVES EAST THEY SHOULD DECREASE IN INTENSITY. THAT SAID...WILL KEEP THE FORECAST FOR THE REMAINDER OF TONIGHT `AS IS`...WHICH SHOWS THE BEST CHANCES FOR THE REMAINDER OF THIS EVENING OVER CENTRAL LOCATIONS...WITH A LESSER THREAT TO THE EAST. IF IT LOOKS LIKE THE ACTIVITY WILL HOLD TOGETHER OVER THE NEXT HOUR OR TWO...WILL UPDATE THE FORECAST TO INCREASE POPS TO THE EAST. WILL MAKE SOME ADJUSTMENTS TO THE OVERNIGHT LOW TEMPS TO ACCOUNT FOR CURRENT TEMP TRENDS...WHERE SOME AREAS HAVE BEEN SIGNIFICANTLY RAIN COOLED DUE TO THUNDERSTORMS IN THE AREA. FOR DETAILS REGARDING THE FORECAST BEYOND TONIGHT...PLEASE REFER TO THE PREVIOUS DISCUSSION BELOW. && .AVIATION...VALID THRU 19/06Z. SCATTERED TO NUMEROUS -SHRA/-TSRA THIS EVENING FOLLOWED BY SCATTERED SHOWERS/TSTMS LATE TONIGHT THRU SUNDAY AFTERNOON. THE BULK OF THIS ACTIVITY SUNDAY WILL OCCUR FROM KTUS VICINITY EAST TO THE NEW MEXICO BORDER. MVFR CONDITIONS AND BRIEF IFR CONDITIONS WILL OCCUR AT TIMES THROUGH SUNDAY AFTERNOON. OTHERWISE...CLOUD DECKS WILL BE AROUND 8- 12K FT AGL AND SURFACE WIND WILL GENERALLY BE EASTERLY TO SOUTHERLY AT 5-15 KTS WITH GUSTS TO AROUND 25 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS EVENING...BUT THEY SHOULD GRADUALLY DIMINISH AS THEY MOVE EAST. SCATTERED SHOWERS AND THUNDERSTORMS WILL PREVAIL ESPECIALLY EAST OF TUCSON SUNDAY FOLLOWED BY MARKEDLY LESS COVERAGE OF SHOWERS AND THUNDERSTORMS MONDAY. THE NEXT LOW PRESSURE SYSTEM WILL THEN BRING A MUCH BETTER CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY. DRY CONDITIONS WILL RETURN BY NEXT WEEKEND. && .PREV DISCUSSION...THE UPPER LEVEL PATTERN SUN WILL BE CHARACTERIZED WITH A LOW PRESSURE TROUGH OVER THE WRN CONUS...AND LOW PRESSURE CENTERED OVER NRN CALIFORNIA. 17/12Z GFS/ECMWF/CMC WERE SIMILAR WITH DEPICTING A DRIER REGIME ESPECIALLY ABOVE 500 MB ENCROACHING UPON SWRN ARIZONA SUN...AND A DRIER 700-500MB LAYER ACROSS MUCH OF THIS FORECAST AREA MON. THIS WILL TRANSLATE INTO REDUCED PRECIP CHANCES SUN AND PARTICULARLY MON. HOWEVER...THERE WILL STILL BE ENOUGH MOISTURE FOR SCATTERED SHOWERS/TSTMS SUN AFTERNOON/EVENING MAINLY FROM TUCSON EAST TO THE NEW MEXICO BORDER. ISOLATED SHOWERS/TSTMS SHOULD OCCUR MAINLY ACROSS ERN SECTIONS MON. THE UPPER LEVEL TROUGH IS PROGGED TO DEEPEN OVER THE SWRN CONUS TUE...WITH LOW PRESSURE TO BE CENTERED NEAR LAS VEGAS NEVADA. THE GFS/ECMWF WERE NEARLY IDENTICAL WITH DEPICTING A 568 DM LOW TO BE CENTERED NEAR THE INTERNATIONAL BORDER WEST OF NOGALES MIDDAY WED. BASED ON THESE SOLUTIONS...POPS WERE RAISED INTO THE CHANCE-CATEGORY AREA-WIDE TUE AND TUE NIGHT...THEN CHANCE-CATEGORY TO LOW-END LIKELY CATEGORY WED. TEMPS/THICKNESSES MAY BE LOW ENOUGH TO SUPPORT SOME ACCUMULATING SNOW ACROSS THE HIGHEST PEAKS OF THE WHITE MOUNTAINS AND MOUNT GRAHAM LATE WED NIGHT/EARLY THUR MORNING. GFS/ECMWF REMAIN VERY CONSISTENT WITH LIFTING THE UPPER LOW TO NEAR THE FOUR CORNERS REGION MIDDAY THUR. A DRYING TREND SHOULD START THUR AS THE FLOW ALOFT BECOMES INCREASINGLY WLY. THUS...PRECIP CHANCES SHOULD DIMINISH FROM WEST-TO-EAST THUR. PRECIP-FREE CONDITIONS ARE FORECAST TO OCCUR AREA-WIDE THUR NIGHT-SAT WITH ANY MEASURABLE PRECIP TO REMAIN NORTH-TO-EAST OF THIS FORECAST AREA. HIGH TEMPS SUN-MON WILL AVERAGE A FEW DEGS ABOVE NORMAL...THEN BELOW NORMAL DAYTIME TEMPS WILL PREVAIL TUE-THUR. HIGH TEMPS ARE FORECAST TO TREND CLOSER TO SEASONAL NORMALS BY NEXT WEEKEND. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ CURRENT DISCUSSION...MOLLERE PREVIOUS DISCUSSION...FRANCIS VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
725 PM MST SAT OCT 17 2015 .SYNOPSIS... A SERIES OF SLOW MOVING LOW PRESSURE SYSTEMS WILL BRING ELEVATED CHANCES OF SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE MIDDLE OF NEXT WEEK. SHOWERS AND STORMS ARE POSSIBLE ACROSS SOUTH CENTRAL AZ TONIGHT AND SUNDAY AS THE FIRST LOW PRESSURE SYSTEM PASSES ACROSS THE REGION...WITH A MODEST DRYING TREND ON MONDAY. THIS WILL BE SHORT LIVED AS A SECOND LOW MOVES INTO THE DESERT SOUTHWEST ON TUESDAY...AND REMAINS IN PLACE THROUGH THURSDAY. DRIER AIR WILL THEN MOVE INTO THE AREA LATE NEXT WEEK. && .DISCUSSION... TWO DISTINCT PV ANOMALIES CAN BE SEEN ON EARLY EVENING WV IMAGERY TRANSLATING THROUGH THE BROAD SWRN CONUS CYCLONIC FLOW. THE FIRST SMALL FEATURE HAS PROPAGATED FROM SWRN ARIZONA TOWARDS THE TUCSON AREA...WHILE ANOTHER MORE PRONOUNCED CIRCULATION HAS MOVED INTO WRN CHIHUAHUA. THE RESULTANT STRONGLY DIFLUENT JET FLOW AND SYNOPTIC ASCENT HAS TAPPED MODEST INSTABILITY (MLCAPES NEAR 500 J/KG) ALBEIT IN AN ENVIRONMENT WITH POOR MIDLEVEL LAPSE RATES. HOWEVER...HIGHER DCAPE VALUES ABOVE 1000 J/KG HAVE PROMOTED MORE AGGRESSIVE OUTFLOW BOUNDARIES FEEDING THE FOCUS FOR FURTHER SHOWER DEVELOPMENT. RECENT HRRR ITERATIONS SEEM TO CAPTURE THE TRENDS THUS FAR IN THE EVENING WITH PRIMARY CONVECTIVE FOCUS CLOSER TO THE PV ANOMALY IN SERN ARIZONA...AND DECAYING/SPORADIC SHOWERS TO THE NORTH. THROUGH THE WRN HALF OF THE FORECAST AREA...WV IMAGERY AND OBJECTIVE ANALYSIS SUGGEST A LARGER MEASURE OF ANTI-CYCLONIC FLOW AND SYNOPTIC SUBSIDENCE...SO HAVE CUT POPS ALONG AND WEST OF THE COLORADO RIVER THROUGH SUNDAY. OTHERWISE...ONLY MINOR CHANGES WERE NEEDED TO ACCOUNT FOR HOURLY TRENDS IN TEMPERATURE FORECAST THIS EVENING. && .PREVIOUS DISCUSSION... /130 PM MST SAT OCT 17 2015/ SUNDAY THROUGH MONDAY... MUCH OF SUNDAY LOOKS LIKE IT WILL BE DRY IN MOST AREAS...ALTHOUGH THE COMBINATION OF LINGERING MOISTURE AND UPSLOPE SOUTHWESTERLY FLOW COULD TRIGGER SOME SHOWER ACTIVITY AGAIN ON SUNDAY AFTERNOON ACROSS SOUTH-CENTRAL AZ...MAINLY OVER THE HIGHER TERRAIN EAST OF PHOENIX. MONDAY LOOKS LIKE IT WILL BE EVEN DRIER...AS WEAK SHORTWAVE RIDGING BUILDS BRIEFLY OVER THE REGION AHEAD OF THE NEXT UPPER TROF. OUTSIDE OF PERHAPS A FEW SHOWERS OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX...THE ONLY OTHER PLACE THAT COULD SEE SOME ISOLATED SHOWERS IS OVER THE HIGHER TERRAIN OF LA PAZ COUNTY...AS LOW-LEVEL SOUTHERLY FLOW PULLS A SURGE OF MOISTURE NORTHWARD FROM THE GULF OF CALIFORNIA. HIGH TEMPERATURES ON SUNDAY AND MONDAY APPEAR THAT THEY WILL BE NEAR OR JUST SLIGHTLY ABOVE NORMAL. TUESDAY THROUGH THURSDAY... FURTHER COOLING AND ANOTHER CHANCE FOR RAINFALL APPEARS TO BE ON THE WAY FOR THIS TIME PERIOD. THE GFS...EURO...AND MANY OF THEIR ENSEMBLE MEMBERS ARE NOW SHOWING A RATHER DEEP UPPER TROF DIGGING SOUTHEASTWARD INTO THE LOWER COLORADO RIVER VALLEY BY LATE TUESDAY...THEN WOBBLING VERY SLOWLY EASTWARD ACROSS SOUTHERN AZ ON WEDNESDAY AND THURSDAY AS IT TEMPORARILY GETS CUT OFF FOR THE MAIN POLAR JET. ALTHOUGH THIS SYSTEM WILL BE A PRETTY DYNAMIC ONE WITH COLDER AIR ALOFT (500MB TEMPS IN THE -15C TO -16C RANGE) VERSUS WHAT WE ARE SEEING WITH THE CURRENT SYSTEM...MOISTURE WITH THIS NEW SYSTEM APPEARS IT WILL BE MORE LIMITED WITH PWATS MAINLY IN THE 0.70- 1.00 INCH RANGE AT MOST. THIS IS LIKELY DUE TO THE SYSTEM/S MORE NORTHERLY ORIGIN OVER THE NE PACIFIC WHICH WILL LIKELY LIMIT RAINFALL CHANCES/COVERAGE. STILL...IT APPEARS THAT SHOWER CHANCES WILL BE AT LEAST IN THE CHANCE-LIKELY RANGE WITH THE BEST CHANCES BEING LATE TUESDAY/EARLY WEDNESDAY OVER SOUTH-CENTRAL AZ. ALONG WITH THE RETURN OF SHOWER CHANCES...IT APPEARS TEMPERATURES WILL LIKELY FALL BELOW NORMAL DURING THIS PERIOD WITH THE CONSENSUS GUIDANCE SHOWING LOWER DESERT HIGHS IN THE LOW-MID 80S EACH DAY. TEMPERATURES COULD TURN OUT TO BE EVEN COOLER IF IT TURNS OUT WE GET MORE RAIN/CLOUDS THEN WE CURRENTLY EXPECT. FRIDAY AND SATURDAY... AT THIS TIME...IT APPEARS THAT THIS WILL BE A DRY COUPLE OF DAYS WITH SLIGHTLY WARMER TEMPERATURES...AS THE MAIN TROF MOVES OFF TO THE EAST AND FLAT RIDGING BUILDS OVER THE REGION && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SCT SHOWERS WILL AFFECT TERMINAL SITES THROUGH THIS EVENING...THEN AGAIN POSSIBLY LATE SUNDAY AFTERNOON. THOUGH AN ISOLD TSRA COULD BE CONTAINED WITH THE SHOWERS...COVERAGE WILL BE VERY LIMITED AND NOT MENTIONED IN TAF PACKAGE. EASTERLY SFC WINDS WILL BE FAVORED FOR MUCH OF THE PERIOD...HOWEVER SOUTHERLY OUTFLOW MAY COULD CAUSE AN HOUR OR TWO OF SHIFTING WINDS THIS EVENING. CIGS SHOULD REMAIN ABOVE 6K FT THROUGH SUNDAY AFTERNOON. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... LITTLE TO NO AVIATION CONCERN THROUGH SUNDAY AFTERNOON AS SHOWER ACTIVITY REMAINS NORTH AND EAST OF TERMINAL SITES. KBLH SFC WINDS COULD BECOME GUSTY OUT OF THE SOUTH SUNDAY AFTERNOON. OTHERWISE...ONLY SCT CLOUD DECKS FOR THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... UNSETTLED WEATHER DURING THE MIDDLE OF THE WEEK WILL TRANSITION TO MUCH DRIER CONDITIONS LATE IN THE WEEK. WETTING RAINS WILL FAVOR CENTRAL ARIZONA DISTRICTS...AND ESPECIALLY HIGHER TERRAIN LOCATIONS NORTH AND EAST OF PHOENIX. AFTERNOON HUMIDITY VALUES IN A 25 TO 40 PERCENT RANGE EARLIER IN THE WEEK WILL DECREASE TO A 20 TO 30 PERCENT RANGE BY THE END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. WIND SPEEDS WILL NOT BE PARTICULARLY STRONG...WITH ONLY SOME OCCASIONAL HIGHER GUSTS IN SOUTHEAST CALIFORNIA TUESDAY AND WEDNESDAY AFTERNOON. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...MO/PERCHA AVIATION...MO FIRE WEATHER...MO
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
226 PM MST FRI OCT 16 2015 .UPDATE...UPDATED AVIATION...FIRE WEATHER...AND WATCHES/WARNING/ADVISORY SECTIONS. && .SYNOPSIS... LOW PRESSURE MOVING IN FROM THE PACIFIC WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE WEEKEND...WITH THE POTENTIAL FOR LOCALLY HEAVY RAIN AND GUSTY WINDS FROM THE STRONGEST STORMS. AFTER A BIT OF A BREAK ON MONDAY...A SECOND PACIFIC LOW PRESSURE SYSTEM WILL BRING ANOTHER CHANCE FOR PRECIP AND COOLER TEMPERATURES DURING THE MIDDLE PORTION OF NEXT WEEK...WITH A DRYING TREND FORECAST FOR THE END OF NEXT WEEK. && .DISCUSSION.../ISSUED 110 PM MST 16 OCTOBER 2015/... TONIGHT THROUGH SATURDAY NIGHT... LATEST SATELLITE AND RADAR LOOPS ARE NOW SHOWING THE DEVELOPMENT OF SHOWERS AND A FEW THUNDERSTORMS ACROSS WESTERN AND EXTREME SOUTHERN ARIZONA...AS THE UPPER LOW THAT BROUGHT LOCALLY HEAVY RAIN AND FLASH FLOODING TO PARTS OF SOUTHERN CA BEGINS TO MOVE ACROSS SOUTH-CENTRAL CA. THE LATEST HRRR AND 4KM NAM HIGH-RES MODELS CONTINUE TO SHOW THE DEVELOPMENT OF MORE SHOWER/THUNDERSTORM ACTIVITY ACROSS SOUTH-CENTRAL ARIZONA LATER THIS AFTERNOON AND EVENING...BEING TRIGGERED BY A JET MAX/SHORTWAVE THAT CAN BE SEEN ON WV SATELLITE IMAGERY APPROACHING THE REGION FROM THE SW...AS IT ROTATES AROUND THE MAIN UPPER-LEVEL TROF. AS FAR AS THE POTENTIAL FOR FLASH FLOODING/SEVERE WEATHER IS CONCERNED...THE LATEST SPC SREF FORECAST CONTINUES TO SHOW 0-6KM BULK SHEAR VALUES ONLY RISING INTO THE 20-25KT RANGE THIS EVENING...WITH MUCAPES VALUES REMAINING IN THE 500-1000 J/KG RANGE. THUS...IT APPEARS THAT CHANCES FOR SEVERE STORMS APPEAR TO BE ON THE LOW SIDE...WITH GUSTY WINDS AND HAIL BEING THE MAIN THREAT. HEAVY RAIN APPEARS TO BE MORE OF A THREAT...WITH PWATS IN THE 1.00-1.50 INCH RANGE...WHICH IS 2-4 SD ABOVE THE MEAN FOR THIS TIME OF YEAR. ALTHOUGH FAIRLY RAPID STORM MOTION SHOULD LIMIT RAINFALL AMOUNTS IN MOST CASES...TRAINING OF STORMS IS POSSIBLE DUE TO FAIRLY UNIDIRECTIONAL FLOW THROUGH THE COLUMN...WHICH COULD LOCALLY ENHANCE RAINFALL AMOUNTS. ANOTHER...WEAKER SHORTWAVE WILL MOVE THROUGH THE AREA ON SATURDAY. THERMODYNAMIC PARAMETERS AREN`T QUITE AS FAVORABLE FOR DEEP CONVECTION ON SATURDAY BUT STILL IMPRESSIVE ENOUGH TO WARRANT POPS THAT ARE WELL ABOVE CLIMO FOR MID OCTOBER. MUCH LIKE TODAY...IT WOULD APPEAR SATURDAY AFTERNOON/EVENING WILL BE MORE ACTIVE THAN SATURDAY MORNING ALTHOUGH MID LEVEL DRY ADVECTION WILL ALREADY BE UNDERWAY BY THIS POINT AND AREAL COVERAGE SHOULD BE MUCH LESS THAN FRIDAY. SUNDAY THROUGH FRIDAY... THE FORECAST FOR SUNDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WILL REMAIN RATHER UNSETTLED. ON SUNDAY...THE AFOREMENTIONED UPPER LOW WILL BE SHIFTING OFF TO THE EAST OF OUR CWA...WITH RAINFALL CHANCES ENDING FROM WEST TO EAST. AFTER A DRY DRY ON MONDAY AS ANOTHER UPPER TROF PASSES OFF WELL TO OUR NORTH...THERE IS GROWING CONSENSUS BETWEEN THE GLOBAL MODEL SUITES...AND MANY OF THEIR RESPECTIVE MEMBERS...THAT A RATHER DEEP UPPER LOW WILL DROP SOUTHEASTWARD INTO THE DESERT SW. ALTHOUGH AVAILABLE MOISTURE VALUES WILL BE LESS THEN HAT WE ARE SEEING WITH THE CURRENT LOW CENTER THIS IS AFFECTING OUR REGION...MUCH COLDER AIR ALOFT (500MB TEMPS IN THE -16 TO -18C RANGE) AND STRONGER WINDS THROUGH THE COLUMN SHOULD PROVIDE GREATER LIFT FOR SHOWER/THUNDERSTORM DEVELOPMENT. THUS...HAVE DECIDED TO RAISE POPS AND COOL TEMPS DURING THIS PERIOD...WITH LOWER DESERT HIGHS LIKELY FALLING INTO THE LOW-MID 80 RANGE BY WEDNESDAY. NEXT THURSDAY AND FRIDAY WILL LIKELY SEE SOMEWHAT WARMER AND DRIER CONDITIONS AS THE UPPER LOW MOVES OFF TO THE NORTHEAST. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... INCREASING MID/HIGH CLOUDS THROUGH THIS AFTERNOON WILL GRADUALLY LOWER WITH 8-10K FT CIGS DEVELOPING LATER THIS AFTERNOON/EARLY EVENING. RAIN AND THUNDERSTORM CHANCES WILL CONTINUE THROUGH 04Z WITH ISOLATED THUNDERSTORMS PRODUCING LOCALLY GUSTY WINDS 20 TO 25 KTS AND POSSIBLE LOCALLY REDUCED VISIBITLITY FROM BLOWING DUST. LOCATIONS AROUND PHOENIX AND EASTWARD WILL BE IMPACTED THROUGH ABOUT 04Z BEFORE GREATLY IMPROVING. HAVE KEPT VSTS FOR ALL PHOENIX TAF SITES. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... RAIN CHANCES WILL REMAIN MOSTLY ACROSS ARIZONA WITH SOME LIGHT SHOWER ACTIVITY NEAR KBLH. CIGS AROUND 10K FT WILL LIKELY PERSIST THROUGH THE AFTERNOON BEFORE LIFTING HIGHER THIS EVENING. EXPECTING WINDS TO REMAIN MOSTLY CALM THROUGH THE EVENING HOURS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... MONDAY THROUGH FRIDAY... UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT. LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE WEATHER IMPACT. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...DUST STORM WARNING UNTIL 4 PM MST THIS AFTERNOON FOR AZZ023-028. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/LEINS AVIATION...DEWEY FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
110 PM MST FRI OCT 16 2015 && .SYNOPSIS... LOW PRESSURE MOVING IN FROM THE PACIFIC WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE WEEKEND...WITH THE POTENTIAL FOR LOCALLY HEAVY RAIN AND GUSTY WINDS FROM THE STRONGEST STORMS. AFTER A BIT OF A BREAK ON MONDAY...A SECOND PACIFIC LOW PRESSURE SYSTEM WILL BRING ANOTHER CHANCE FOR PRECIP AND COOLER TEMPERATURES DURING THE MIDDLE PORTION OF NEXT WEEK...WITH A DRYING TREND FORECAST FOR THE END OF NEXT WEEK. && .DISCUSSION... TONIGHT THROUGH SATURDAY NIGHT... LATEST SATELLITE AND RADAR LOOPS ARE NOW SHOWING THE DEVELOPMENT OF SHOWERS AND A FEW THUNDERSTORMS ACROSS WESTERN AND EXTREME SOUTHERN ARIZONA...AS THE UPPER LOW THAT BROUGHT LOCALLY HEAVY RAIN AND FLASH FLOODING TO PARTS OF SOUTHERN CA BEGINS TO MOVE ACROSS SOUTH-CENTRAL CA. THE LATEST HRRR AND 4KM NAM HIGH-RES MODELS CONTINUE TO SHOW THE DEVELOPMENT OF MORE SHOWER/THUNDERSTORM ACTIVITY ACROSS SOUTH-CENTRAL ARIZONA LATER THIS AFTERNOON AND EVENING...BEING TRIGGERED BY A JET MAX/SHORTWAVE THAT CAN BE SEEN ON WV SATELLITE IMAGERY APPROACHING THE REGION FROM THE SW...AS IT ROTATES AROUND THE MAIN UPPER-LEVEL TROF. AS FAR AS THE POTENTIAL FOR FLASH FLOODING/SEVERE WEATHER IS CONCERNED...THE LATEST SPC SREF FORECAST CONTINUES TO SHOW 0-6KM BULK SHEAR VALUES ONLY RISING INTO THE 20-25KT RANGE THIS EVENING...WITH MUCAPES VALUES REMAINING IN THE 500-1000 J/KG RANGE. THUS...IT APPEARS THAT CHANCES FOR SEVERE STORMS APPEAR TO BE ON THE LOW SIDE...WITH GUSTY WINDS AND HAIL BEING THE MAIN THREAT. HEAVY RAIN APPEARS TO BE MORE OF A THREAT...WITH PWATS IN THE 1.00-1.50 INCH RANGE...WHICH IS 2-4 SD ABOVE THE MEAN FOR THIS TIME OF YEAR. ALTHOUGH FAIRLY RAPID STORM MOTION SHOULD LIMIT RAINFALL AMOUNTS IN MOST CASES...TRAINING OF STORMS IS POSSIBLE DUE TO FAIRLY UNIDIRECTIONAL FLOW THROUGH THE COLUMN...WHICH COULD LOCALLY ENHANCE RAINFALL AMOUNTS. ANOTHER...WEAKER SHORTWAVE WILL MOVE THROUGH THE AREA ON SATURDAY. THERMODYNAMIC PARAMETERS AREN`T QUITE AS FAVORABLE FOR DEEP CONVECTION ON SATURDAY BUT STILL IMPRESSIVE ENOUGH TO WARRANT POPS THAT ARE WELL ABOVE CLIMO FOR MID OCTOBER. MUCH LIKE TODAY...IT WOULD APPEAR SATURDAY AFTERNOON/EVENING WILL BE MORE ACTIVE THAN SATURDAY MORNING ALTHOUGH MID LEVEL DRY ADVECTION WILL ALREADY BE UNDERWAY BY THIS POINT AND AREAL COVERAGE SHOULD BE MUCH LESS THAN FRIDAY. SUNDAY THROUGH FRIDAY... THE FORECAST FOR SUNDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WILL REMAIN RATHER UNSETTLED. ON SUNDAY...THE AFOREMENTIONED UPPER LOW WILL BE SHIFTING OFF TO THE EAST OF OUR CWA...WITH RAINFALL CHANCES ENDING FROM WEST TO EAST. AFTER A DRY DRY ON MONDAY AS ANOTHER UPPER TROF PASSES OFF WELL TO OUR NORTH...THERE IS GROWING CONSENSUS BETWEEN THE GLOBAL MODEL SUITES...AND MANY OF THEIR RESPECTIVE MEMBERS...THAT A RATHER DEEP UPPER LOW WILL DROP SOUTHEASTWARD INTO THE DESERT SW. ALTHOUGH AVAILABLE MOISTURE VALUES WILL BE LESS THEN HAT WE ARE SEEING WITH THE CURRENT LOW CENTER THIS IS AFFECTING OUR REGION...MUCH COLDER AIR ALOFT (500MB TEMPS IN THE -16 TO -18C RANGE) AND STRONGER WINDS THROUGH THE COLUMN SHOULD PROVIDE GREATER LIFT FOR SHOWER/THUNDERSTORM DEVELOPMENT. THUS...HAVE DECIDED TO RAISE POPS AND COOL TEMPS DURING THIS PERIOD...WITH LOWER DESERT HIGHS LIKELY FALLING INTO THE LOW-MID 80 RANGE BY WEDNESDAY. NEXT THURSDAY AND FRIDAY WILL LIKELY SEE SOMEWHAT WARMER AND DRIER CONDITIONS AS THE UPPER LOW MOVES OFF TO THE NORTHEAST. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... PERIODIC MID/HIGH CLOUDS THIS MORNING WILL GRADUALLY LOWER WITH 10- 12K FT CIGS DEVELOPING FOR THIS AFTERNOON. RAIN CHANCES PICK BACK UP AROUND 18Z WITH BEST CHANCES FOR ISOLATED THUNDERSTORMS FROM LATE AFTERNOON THROUGH EARLY EVENING AND OCCURRING MAINLY FROM PHOENIX EASTWARD. SFC WINDS TO MAINTAIN AN EASTERLY COMPONENT THROUGHOUT THE PERIOD AND COULD BECOME GUSTY FROM STORM OUTFLOWS LATE THIS AFTERNOON AND EVENING. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... RAIN CHANCES HAVE DIMINISHED CONSIDERABLY WITH ONLY LIMITED CHANCES THROUGH THIS AFTERNOON AND MAINLY FURTHER NORTH AND EAST. HAVE KEPT VCSH AT KBLH...BUT FEEL CHANCES ARE TOO LOW TO KEEP ANY MENTION OF SHOWERS AT KIPL. CIGS AROUND 10K FT WILL LIKELY PERSIST INTO THE AFTERNOON BEFORE LIFTING HIGHER THIS EVENING. WINDS WILL INITIALLY BE GUSTY OUT OF THE NORTH AT KBLH...BUT EXPECTING WINDS TO SLACKEN OFF QUICKLY LATER THIS MORNING. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT. LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE WEATHER IMPACT. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/LEINS AVIATION...KUHLMAN FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS TUCSON AZ
313 AM MST FRI OCT 16 2015 .SYNOPSIS...MULTIPLE WEATHER SYSTEMS WILL IMPACT THE REGION THROUGH EARLY NEXT WEEK...RESULTING IN SHOWERS AND THUNDERSTORMS AS WELL AS COOLER TEMPERATURES. THERE IS AN ELEVATED RISK FOR STRONGER THUNDERSTORMS TODAY AND SATURDAY AS THE FIRST SYSTEMS PASS ACROSS THE AREA. TEMPERATURES WILL COOL TO NEAR NORMAL LEVELS SATURDAY AND BEYOND. && .DISCUSSION...UNSETTLED WEATHER IN TERMS OF SHOWERS AND THUNDERSTORMS CAN BE ANTICIPATED THE NEXT FEW DAYS AS A COUPLE OF WEATHER SYSTEMS IMPACT THE REGION. THE FIRST SYSTEM WAS SPINNING OVER THE CENTRAL CALIFORNIA COAST THIS MORNING WITH A WEAK DISTURBANCE EMBEDDED IN THE FLOW AHEAD OF IT PASSING THROUGH ARIZONA. THIS FEATURE WAS HELPING TRIGGER SOME SHOWERS ACROSS MAINLY NORTHERN SECTIONS OF THE STATE SOUTH THROUGH EAST-CENTRAL AND FAR SOUTHEAST ARIZONA EARLY THIS MORNING. LATEST HRRR SOLUTION APPEARED TO DEPICT THE AREAS OF SHOWERS VERY WELL IN THE SHORT TERM WITH THE AREAL COVERAGE INCREASING BY 22Z TODAY. BASED ON THIS...LOWERED POP VALUES A BIT FOR THIS MORNING MOST AREAS AND SHOWED THE INCREASING TREND FOR THIS AFTERNOON AND EVENING. SPC GUIDANCE SUPPORTED THE POSSIBILITY OF STRONG THUNDERSTORMS WITH WIND AND HAIL BEING THE PRIMARY CONCERNS FOR TODAY. THE GFS AND ECMWF MODELS SHOWED THE CLOSED UPPER LOW SPINNING OVER CENTRAL CALIFORNIA WEAKENING AND BECOMING AN OPEN WAVE BY TONIGHT. MODELS LIFT THIS FEATURE NORTHEAST IN RESPONSE TO A SECONDARY SYSTEM ENTERING THE PACIFIC NORTHWEST ON SATURDAY. THE TAIL END WILL PASS THROUGH SOUTHERN ARIZONA TONIGHT INTO LATE SATURDAY. AS A RESULT...RAIN CHANCES AREAWIDE WILL CONTINUE THROUGH LATE SATURDAY WITH STRONG THUNDERSTORMS AGAIN. WILL LIKELY SEE A BRIEF BREAK IN THE SHOWERY WEATHER ON SUNDAY BEFORE THE SECOND SYSTEM STARTS TO IMPACT THE DESERT SOUTHWEST. THIS NEXT SYSTEM WAS PROGGED TO DROP SOUTH INLAND AND INTO SOUTHERN CALIFORNA BY EARLY TUESDAY BASED ON THE GFS SOLUTION. THE ECMWF SHOWED SOMEWHAT OF A DIFFERENT IDEA IN TERMS OF THE SYSTEM EVOLUTION AND TRACK. AT ANY RATE...THE SYSTEM WILL BRING MORE RAIN CHANCES TO THE AREA EARLY NEXT WEEK. && .AVIATION...VALID THRU 17/12Z. SCTD TO LCLY BKN 10-12KFT AGL WITH ISOLD -SHRA THRU 16/17Z...MAINLY FROM KTUS E AND N. AFT 16/17Z...BKN 6-10KFT AGL WITH LYRS ABV. SCT SHRA/ISOLD +TSRA DVLPG W-SW OF KTUS AND SPRDG TO ENE. LCL MVFR CONDS VCNTY OF STRONG TSTORMS. SFC WINDS MAINLY FROM THE E-SE 5-15 KTS. GUSTS ARND 45 KTS NR STRONG AFTN T-STORMS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...INCREASED MOISTURE AND A PASSING STORM SYSTEM WILL BRING PERIODS OF SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH SATURDAY. THE BEST CHANCE FOR SHOWERS AND STRONG TO POSSIBLY SEVERE THUNDERSTORMS WILL BE THIS AFTERNOON AND ONCE AGAIN ON SATURDAY AFTERNOON WITH THE GREATEST COVERAGE FROM THE TUCSON AREA EASTWARD. SHOWERS AND STORMS WILL LIKELY CONTINUE THROUGH FRIDAY NIGHT AS WELL. THUNDERSTORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS AND ERRATIC WIND GUSTS IN EXCESS OF 40 MPH AND HAIL. A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORM CHANCES WILL THEN LINGER THROUGH EARLY TUESDAY MORNING. RECENT MODEL TRENDS ARE SUGGESTING ANOTHER UPPER LOW WILL AFFECT THE AREA NEXT WEEK FOR ANOTHER ROUND OF PRECIPITATION. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
135 PM PDT FRI OCT 16 2015 .SYNOPSIS... A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM MOVING ACROSS SOUTHERN CALIFORNIA WILL LIKELY RESULT IN SCATTERED THUNDERSTORMS FOR THE MOUNTAINS...DESERTS AND VALLEYS THIS AFTERNOON AND EVENING. SOME RESIDUAL MOISTURE AND INSTABILITY COULD CREATE A FEW THUNDERSTORMS OVER THE MOUNTAINS AND HIGH DESERTS SATURDAY AFTERNOON. A SECOND LOW PRESSURE SYSTEM FROM THE NORTHWEST WILL CONTINUE A CHANCE FOR SHOWERS AND THUNDERSTORMS FOR SUNDAY. A DEEP MARINE LAYER WILL CONTINUE...WITH NIGHT AND MORNING CLOUDS FILLING THE COASTAL BASIN...AND DRIZZLE OCCURRING AT TIMES. ANOTHER LOW PRESSURE SYSTEM MAY MOVE OVER THE REGION DURING THE MIDDLE TO LATER PART OF NEXT WEEK. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... A SLOWLY EASTWARD MOVING UPPER LEVEL LOW IS CURRENTLY OVER CENTRAL CALIFORNIA ACCORDING TO WATER VAPOR SATELLITE. THE 12Z MIRAMAR SOUNDING CONTINUES TO SHOW A MOIST AND UNSTABLE ATMOSPHERE...WITH 1.4 INCHES OF PRECIPITABLE WATER AND 1336 J/KG OF MOST UNSTABLE CAPE. IT ALSO SHOWS SOUTHEASTERLY WINDS OF 15-25 KT BETWEEN 850 AND 550 MB...AND SOUTHWESTERLY WINDS OF 15-25 KT ABOVE THAT LEVEL. MEANWHILE...YESTERDAY THE WINDS WERE SOUTHERLY THROUGH MOST OF THE LAYER AT 20-40 KT. THUS...IT IS APPARENT THAT THE WINDS ALOFT ARE A BIT WEAKER TODAY...AND WILL LIKELY CONTINUE TO WEAKEN DURING THE DAY AS THE LOW MOVES EASTWARD INTO THE FORECAST AREA. THE ELEVATED SHOWERS AND THUNDERSTORMS WE ARE CURRENTLY SEEING OVER NORTHERN PORTIONS OF THE AREA MAY CONTINUE THROUGH THE AFTERNOON...WHILE SURFACE BASED THUNDERSTORMS WILL LIKELY INITIATE OVER THE MOUNTAINS AS THE AFTERNOON CONTINUES. THE HRRR AND MOST OF THE HI-RES MODELS CONTINUE TO INDICATE THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS AND HIGH DESERTS DUE TO DAY-TIME HEATING INDUCED INSTABILITY WHICH SHOULD OCCUR...AS VISIBLE SATELLITE SHOWS ENOUGH BREAKS IN THE CLOUDS OVER THOSE AREAS. THE LATEST SPC MESOANALYSIS PAINTS 1000 J/KG OF SURFACE BASED CAPE OVER THE MOUNTAINS AND DESERTS. SOME OF THESE STORMS MAY MOVE INTO THE LOWER DESERTS...AND THE HRRR SHOWS STORMS ALSO DEVELOPING IN THE INLAND EMPIRE LATE IN THE DAY. WITH THE WEAKER WINDS ALOFT...SURFACE BASED THUNDERSTORMS ARE LIKELY TO BE SOMEWHAT SLOW MOVING...INCREASING THE THREAT FOR FLASH FLOODING. PLEASE SEE THE HYDROLOGY SECTION BELOW FOR DETAILS ON THE FLASH FLOOD THREAT. MEANWHILE...A DEEP MARINE LAYER AND THE NEARBY TROUGH HAS CONTINUED TO BRING BRING AREAS OF DRIZZLE TO THE COASTS AND VALLEYS THIS AFTERNOON...WITH MANY STATIONS REPORTING LIGHT ACCUMULATIONS OF A FEW HUNDREDTHS OF AN INCH...TO AS MUCH AS A TENTH OF AN INCH. LATEST VISIBLE SATELLITE SHOWS A SOLID STRATUS DECK...WITH ANY FURTHER CLEARING UNLIKELY. THUS...PATCHY TO MORE WIDESPREAD DRIZZLE WILL LIKELY CONTINUE THROUGH THE REST OF THE DAY AND INTO TONIGHT AND SATURDAY MORNING FOR COASTAL AREAS AND PORTIONS OF THE VALLEYS. SHOWER/THUNDERSTORM ACTIVITY SHOULD DISSIPATE OVERNIGHT AS THE TROUGH PROGRESSES ACROSS THE REGION AND THE WINDS ALOFT TURN WESTERLY. THERE SHOULD BE DRYING AND CLEARING OF SKIES AS WELL SATURDAY...BUT ENOUGH RESIDUAL MOISTURE AROUND THE AREA COULD BRING A THUNDERSTORM OR TWO TO THE MOUNTAINS AND HIGH DESERTS SATURDAY AFTERNOON. ON SUNDAY...A SHORT-WAVE TROUGH WILL MOVE ACROSS CENTRAL CALIFORNIA...AND COULD BRING SHOWERS TO AREAS OVER AND WEST OF THE MOUNTAINS LATE IN THE DAY...ALTHOUGH MODELS DO NOT SHOW MUCH IN THE WAY OF PRECIPITATION AT THE MOMENT. THE TROUGH WILL BRING STRONGER ONSHORE FLOW TO THE AREA AND MAINTAIN A DEEP MARINE LAYER...WITH TEMPERATURES FALLING TO SEVERAL DEGREES BELOW NORMAL FOR ALL AREAS AWAY FROM THE IMMEDIATE COAST SUNDAY AND MONDAY AND PATCHY DRIZZLE POSSIBLE. GUSTY WESTERLY WINDS IN THE MOUNTAINS AND DESERTS DURING THE AFTERNOONS AND EVENINGS ARE LIKELY AS WELL. THE GFS AND ECMWF THEN SHOW ANOTHER SHORT-WAVE TROUGH DEVELOPING OVER SOUTHERN CALIFORNIA LATE MONDAY...WITH THE SHORT-WAVE SPLITTING OUT OF THE JET-STREAM AND FORMING A CUT-OFF LOW ON TUESDAY. THE 12Z GFS BRINGS THE LOW ACROSS SOUTHERN CALIFORNIA...WITH WRAP-AROUND PRECIPITATION OCCURRING LATE TUESDAY INTO WEDNESDAY. THE 12Z ECMWF AND CANADIAN MODELS HAVE TRENDED A LITTLE FURTHER WEST WITH THE LOW...BRINGING THE LOW INTO SOUTHWEST ARIZONA/EXTREME SOUTHEAST CALIFORNIA...BUT STILL KEEPING SOUTHERN CALIFORNIA DRY. NEVERTHELESS...IT APPEARS THE ECMWF AND CANADIAN ARE TRENDING TOWARDS THE GFS. THERE COULD STILL BE SOME WEAK OFFSHORE FLOW ON TUESDAY AND WEDNESDAY...BUT MODELS CONTINUE TO BACK OFF ON THAT...AND WITH THE LOW NEARBY...OR POSSIBLY DIRECTLY OVER THE REGION...THE FORECAST HAS TRENDED COOLER FOR THAT TIME PERIOD. FOR LATE IN THE WEEK...THE LOW LOOKS TO MOVE OFF TO THE EAST WITH ZONAL FLOW ALOFT PREVAILING. && .AVIATION... 162015Z...COAST/VALLEYS...WIDESPREAD STRATUS WITH BASES 1500-2200 FT MSL AND TOPS TO 4000 FT MSL WILL CONTINUE OVER THE COASTAL BASIN THIS MORNING WITH LITTLE IN THE WAY OF CLEARING THIS AFTERNOON. HIGHER TERRAIN WILL BE OBSCURED AT TIMES...ALONG WITH PATCHY DRIZZLE WEST OF THE MOUNTAINS. A SLIGHT CHANCE OF SHRA/TSRA REMAINS FOR THE INLAND EMPIRE TODAY IF ENOUGH CLEARING OCCURS...CHANCES ENDING THIS EVENING. STRATUS FILLING BACK IN WEST OF THE MTNS BEGINNING EARLY TO MID EVENING WITH SIMILAR BASES AND TOPS THROUGH SATURDAY MORNING. MOUNTAINS/DESERTS...CHANCE OF SHRA/TSRA THIS AFTERNOON AND EVENING WITH BASES NEAR 8000 FT MSL AND TOPS TO 40000 FT MSL. LOCAL VIS 2- 4SM AND SFC GUSTS TO 35 KT POSSIBLE IN HEAVIER TSRA. && .MARINE... 115 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH TUESDAY. && .HYDROLOGY... THE FLASH FLOOD WATCH CONTINUES FOR THE MOUNTAINS...DESERTS AND THE INLAND EMPIRE. THERE WILL LIKELY BE SLOW MOVING THUNDERSTORMS DEVELOPING THIS AFTERNOON OVER THE MOUNTAINS AND HIGH DESERTS...WITH SOME STORMS DRIFTING INTO THE LOWER DESERTS AND THE INLAND EMPIRE. THESE STORMS WILL HAVE THE CAPABILITY TO PRODUCE HEAVY RAINFALL RATES IN EXCESS OF 1 INCH PER HOUR...RESULTING IN POSSIBLE FLASH FLOODING. && .SKYWARN... SKYWARN ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING FOR SAN BERNARDINO...RIVERSIDE AND SAN DIEGO COUNTIES. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...FLASH FLOOD WATCH UNTIL 8 PM PDT THIS EVENING FOR APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-RIVERSIDE COUNTY MOUNTAINS- SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS NEAR BANNING. PZ...NONE. && $$ PUBLIC/HYDROLOGY...HARRISON AVIATION/MARINE...TS
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
941 AM PDT FRI OCT 16 2015 .SYNOPSIS... A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM MOVING ACROSS SOUTHERN CALIFORNIA WILL CONTINUE TO BRING ISOLATED SHOWERS AND THUNDERSTORMS TO NORTHERN AREAS THIS MORNING. HIGH MOISTURE AND DAY-TIME INSTABILITY WILL LIKELY RESULT IN THUNDERSTORMS FOR THE MOUNTAINS...DESERTS AND VALLEYS THIS AFTERNOON AND EVENING. SOME RESIDUAL MOISTURE AND INSTABILITY COULD CREATE A FEW THUNDERSTORMS OVER THE MOUNTAINS AND HIGH DESERTS SATURDAY AFTERNOON. A SECOND LOW PRESSURE SYSTEM FROM THE NORTHWEST WILL CONTINUE A CHANCE FOR SHOWERS AND THUNDERSTORMS FOR SUNDAY AND MONDAY...MAINLY OVER AND WEST OF THE MOUNTAINS. A DEEP MARINE LAYER WILL CONTINUE...WITH NIGHT AND MORNING CLOUDS FILLING THE COASTAL BASIN...WITH DRIZZLE POSSIBLE AT TIMES. DRY AND WARMER FOR THE MIDDLE TO LATER PART OF NEXT WEEK WITH HIGHER PRESSURE ALOFT AND WEAK OFFSHORE FLOW. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... THE UPPER LEVEL LOW IS CURRENTLY OVER CENTRAL CALIFORNIA ACCORDING TO WATER VAPOR SATELLITE...WITH AN UPPER LEVEL WAVE MOVING NORTH OVER SAN BERNARDINO COUNTY...AND A WEAKER WAVE ROTATING TO THE SOUTHEAST NEAR POINT CONCEPTION. THE FIRST WAVE IS RESULTING IN SHOWER AND THUNDERSTORM ACTIVITY OVER SAN BERNARDINO COUNTY AND INTO SOUTHERN NEVADA...WITH SHOWERS MOVING NORTH AT AROUND 25 MPH...WHEREAS THEY WERE MOVING NORTH AT 35 MPH YESTERDAY. THE 12Z MIRAMAR SOUNDING CONTINUES TO SHOW A MOIST AND UNSTABLE ATMOSPHERE...WITH 1.4 INCHES OF PRECIPITABLE WATER AND 1336 J/KG OF MOST UNSTABLE CAPE. IT ALSO SHOWS SOUTHEASTERLY WINDS OF 15- 25 KT BETWEEN 850 AND 550 MB...AND SOUTHWESTERLY WINDS OF 15-25 KT ABOVE THAT LEVEL. MEANWHILE...YESTERDAY THE WINDS WERE SOUTHERLY THROUGH MOST OF THE LAYER AT 20-40 KT. THUS...IT IS APPARENT THAT THE WINDS ALOFT ARE A BIT WEAKER TODAY...AND WILL LIKELY CONTINUE TO WEAKEN DURING THE DAY AS THE LOW MOVES EASTWARD INTO THE FORECAST AREA. THE ELEVATED SHOWERS AND THUNDERSTORMS WE ARE CURRENTLY SEEING WILL PROBABLY CONTINUE THROUGH THE NEXT FEW HOURS FOR THE NORTHERN AREA. THIS AFTERNOON...THE HRRR AND MOST OF THE HI-RES MODELS INDICATE THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS AND HIGH DESERTS DUE TO DAY-TIME HEATING INDUCED INSTABILITY WHICH SHOULD OCCUR WITH ENOUGH BREAKS IN THE CLOUDS. SOME OF THESE STORMS MAY MOVE INTO THE LOWER DESERTS...AND THE HRRR SHOWS STORMS ALSO DEVELOPING IN THE INLAND EMPIRE LATE IN THE DAY. ALTHOUGH MODELS INDICATE THAT THE INSTABILITY WILL BE A LITTLE LESS THAN YESTERDAY...IT SHOULD STILL BE MORE THAN ENOUGH FOR THUNDERSTORM DEVELOPMENT...WITH SURFACE BASED CAPE INCREASING TO 1000-2000 J/KG. WITH THE WEAKER WINDS ALOFT...SURFACE BASED THUNDERSTORMS ARE LIKELY TO BE SOMEWHAT SLOW MOVING...INCREASING THE THREAT FOR FLASH FLOODING. PLEASE SEE THE HYDROLOGY SECTION BELOW FOR DETAILS ON THE FLASH FLOOD THREAT. MEANWHILE...A DEEP MARINE LAYER AND THE NEARBY TROUGH HAS BEEN BRINGING AREAS OF DRIZZLE TO THE COAST AND VALLEY AREAS THIS MORNING...WITH MANY STATIONS REPORTING LIGHT ACCUMULATIONS OF A FEW HUNDREDTHS OF AN INCH...TO AS MUCH AS A TENTH OF AN INCH. ALTHOUGH THERE WILL LIKELY BE PARTIAL CLEARING OF THE MARINE LAYER STRATUS TODAY...IT WILL REMAIN DEEP AND COME BACK IN TONIGHT AND COVER THE COASTAL BASIN AGAIN. DAY-TIME HIGHS TODAY LOOK BE SIMILAR TO YESTERDAY...AT AROUND NEAR NORMAL FOR THIS TIME OF YEAR...ALTHOUGH THE HIGH DEWPOINTS IN THE UPPER 60S/LOW 70S AROUND THE AREA WILL STILL MAKE IT FEEL SOMEWHAT UNCOMFORTABLE. SHOWER/THUNDERSTORM ACTIVITY SHOULD DISSIPATE OVERNIGHT AS THE TROUGH PROGRESSES ACROSS THE REGION AND THE WINDS ALOFT TURN WESTERLY. THERE SHOULD BE DRYING AND CLEARING OF SKIES AS WELL SATURDAY...BUT ENOUGH RESIDUAL MOISTURE AROUND THE AREA COULD BRING A THUNDERSTORM OR TWO TO THE MOUNTAINS AND HIGH DESERTS SATURDAY AFTERNOON. ON SUNDAY...A SHORT-WAVE TROUGH WILL MOVE ACROSS CENTRAL CALIFORNIA...AND COULD BRING SHOWERS TO AREAS OVER AND WEST OF THE MOUNTAINS LATE IN THE DAY...ALTHOUGH MODELS DO NOT SHOW MUCH IN THE WAY OF PRECIPITATION AT THE MOMENT. THE TROUGH WILL BRING STRONGER ONSHORE FLOW TO THE AREA AND MAINTAIN A DEEP MARINE LAYER...WITH TEMPERATURES FALLING TO SEVERAL DEGREES BELOW NORMAL FOR ALL AREAS AWAY FROM THE IMMEDIATE COAST SUNDAY AND MONDAY. GUSTY WESTERLY WINDS IN THE MOUNTAINS AND DESERTS DURING THE AFTERNOONS AND EVENINGS ARE LIKELY AS WELL. THE GFS AND ECMWF THEN SHOW ANOTHER SHORT-WAVE TROUGH DEVELOPING OVER SOUTHERN CALIFORNIA LATE MONDAY...WITH THE TROUGH SPLITTING OUT OF THE JET-STREAM AND FORMING A CUT-OFF LOW ON TUESDAY. HOWEVER...THERE ARE BIG DIFFERENCES WITH WHERE THE MODELS PLACE THE LOW...AS THE 12Z GFS BRINGS IT ACROSS SOUTHERN CALIFORNIA...WITH WRAP-AROUND PRECIPITATION OCCURRING LATE TUESDAY INTO WEDNESDAY. ON THE OTHER HAND...THE 00Z ECMWF AND CANADIAN MODEL KEEP THE LOW OVER ARIZONA RESULTING IN DRY CONDITIONS FOR OUR AREA. THERE COULD STILL BE SOME WEAK OFFSHORE FLOW ON TUESDAY AND WEDNESDAY...BUT MODELS ARE BACKING OFF ON THIS SOMEWHAT. FOR LATE IN THE WEEK...THE LOW LOOKS TO MOVE OFF TO THE EAST WITH ZONAL FLOW ALOFT WITH ABOVE NORMAL TEMPERATURES CONTINUING. && .AVIATION... 161530Z...COAST/VALLEYS...SCT-BKN STRATUS WITH BASES 1500-2200 FT MSL AND TOPS TO 4000 FT MSL WILL CONTINUE OVER THE COASTAL BASIN THIS MORNING WITH SLOW PARTIAL CLEARING EXPECTED 18Z-21Z. HIGHER TERRAIN WILL BE OBSCURED AT TIMES. THERE IS A SLIGHT CHANCE OF SHRA/TSRA IN THE INLAND EMPIRE TODAY...ENDING THIS EVENING. STRATUS FILLING BACK IN WEST OF THE MTNS BEGINNING EARLY TO MID EVENING WITH SIMILAR BASES AND TOPS. MOUNTAINS/DESERTS...CHANCE OF SHRA/TSRA TODAY WITH BASES NEAR 8000 FT MSL AND TOPS TO 40000 FT MSL. LOCAL VIS 2-4SM AND SFC GUSTS TO 35 KT POSSIBLE IN HEAVIER TSRA. && .MARINE... 830 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH TUESDAY. && .HYDROLOGY... THE FLASH FLOOD WATCH HAS BEEN EXTENDED TO INCLUDE THE SAN DIEGO AND RIVERSIDE COUNTY MOUNTAINS AND DESERTS...AND ALSO THE INLAND EMPIRE FOR THIS AFTERNOON THROUGH EARLY EVENING. THERE WILL LIKELY BE SLOW MOVING THUNDERSTORMS DEVELOPING THIS AFTERNOON OVER THE MOUNTAINS AND HIGH DESERTS...WITH SOME STORMS DRIFTING INTO THE LOWER DESERTS AND THE INLAND EMPIRE. THESE STORMS WILL HAVE THE CAPABILITY TO PRODUCE HEAVY RAINFALL RATES IN EXCESS OF 1 INCH PER HOUR...RESULTING IN POSSIBLE FLASH FLOODING. && .SKYWARN... SKYWARN ACTIVATION MAY BE NEEDED THIS AFTERNOON FOR SAN BERNARDINO...RIVERSIDE AND SAN DIEGO COUNTIES. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...FLASH FLOOD WATCH FROM NOON TODAY TO 8 PM PDT THIS EVENING FOR APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS NEAR BANNING. PZ...NONE. && $$ PUBLIC/HYDROLOGY...HARRISON AVIATION/MARINE...TS
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
930 AM PDT FRI OCT 16 2015 .SYNOPSIS... LOW PRESSURE ALOFT WILL BRING THE POSSIBILITY OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS AND DESERTS THROUGH SUNDAY. OTHERWISE...FAIR WEATHER AND SEASONABLE TEMPERATURES WILL PREVAIL. FOR THE MIDDLE OF NEXT WEEK...BUILDING HIGH PRESSURE AND DEVELOPING OFFSHORE WINDS WILL BRING WARMER AND DRIER CONDITIONS TO THE AREA. && .SHORT TERM (TODAY-SUN)...THE UPPER LOW THAT BROUGHT STRONG THUNDERSTORMS TO THE MTNS AND AV YESTERDAY HAS MOVED VERY LITTLE AND BECAUSE OF THIS THE CONVECTIVE PARAMETERS LOOK VERY SIMILAR TODAY. STEERING FLOW REMAINS FAIRLY WEAK OUT OF THE SOUTH AT 15 KT OR LESS CAPES THIS AFTERNOON ARE IN THE 1500-2000 J/KG RANGE, AND PWATS ARE STILL AROUND 1.4". SO THE FLASH FLOOD WATCH IS CERTAINLY JUSTIFIED AND IN FACT IT WOULD BE SURPRISING TO NOT SEE VERY HEAVY RAIN AND AT LEAST SOME FLASH FLOODING SOMEWHERE IN THE MTNS AND/OR AV TODAY GIVEN THESE PARAMETERS. WILL BE INCREASING POPS FOR THE MTNS AND AV TODAY TO EITHER HIGH CHANCE OR LIKELY CATEGORIES. AT LOWER ELEVATIONS A DEEP MARINE LYR BETWEEN 2000 AND 2500` FILLED IN NICELY BUT SHOULD CLEAR TO NEAR THE COAST BY AFTERNOON AS WE HAVE A 2 MB OFFSHORE TREND IN THE GRADIENTS. BASIN PROFILERS SHOW LITTLE CHANGE OR SLIGHT COOLING OF TEMPS UP TO 5000` AND OVERALL HIGHS SHOULD BE SIMILAR TO YESTERDAY. OVERNIGHT TONIGHT CLOUDS SHOULD FILL IN ALL COAST/VALLEYS AGAIN WITH HIGHS SATURDAY SIMILAR TODAY. SATURDAY SHOWS SIMILAR CONVECTIVE PARAMETERS AS TODAY BUT MISSING A LOT OF THE UPPER LEVEL DYNAMICS THAT WE HAVE TODAY AND HAD YESTERDAY. SO WHILE THERE IS STILL A CHANCE OF AFTERNOON STORMS THEY SHOULDN`T BE AS STRONG OR WIDESPREAD. ALSO THE STEERING FLOW SATURDAY, WHILE STILL MOSTLY UNDER 15KT, SHIFTS TO THE WEST. ON SUNDAY A WEAK COLD FRON WILL WASH OUT BEFORE REACHING THE AREA AS THE UPPER LEVEL SYSTEM TAKES A MORE OVER LAND TRAJECTORY. HOWEVER, IT WILL MOISTEN UP THE BOUNDARY LAYER AND MOST AREAS WILL HAVE AT LEAST SOME CLOUDS AND POSSIBLY EVEN A SPRINKLE OR TWO ACROSS THE UPSLOPE AREAS IN THE AFTERNOON FOLLOWED BY SOME POSSIBLE SHOWERS ACROSS THE INTERIOR SLOPE SUNDAY EVENING AS THE FLOW SHIFTS TO THE NORTH AND NORTHEAST. SRN SBA COUNTY EXPECTED TO SEE SOME LOCALLY GUSTY NORTHERLY WINDS THE NEXT FEW EVENINGS, POSSIBLY CLOSE TO ADVISORY LEVELS SATURDAY AND SUNDAY EVENINGS. ***FROM PREVIOUS DISCUSSION*** .LONG TERM (MON-THU)...FOR THE EXTENDED...MODELS CONTINUE TO EXHIBIT DECENT SYNOPTIC AGREEMENT. AT UPPER LEVELS...TROUGH WILL DIVE INTO THE GREAT BASIN ON MONDAY...THEN DEVELOP INTO AN UPPER LOW OVER INTERIOR SOUTHERN CALIFORNIA ON TUESDAY...THEN MEANDER EASTWARD INTO ARIZONA ON WEDNESDAY/THURSDAY AS HIGH PRESSURE MOVES IN FROM THE WEST. NEAR THE SURFACE...NORTHERLY FLOW WILL PREVAIL ON MONDAY THEN SHIFT TO THE NORTHEAST TUESDAY THROUGH THURSDAY. FORECAST-WISE...THE EXTENDED PERIOD SHOULD REMAIN DRY. HOWEVER...THE GFS DOES HAVE THE TROUGH/UPPER LOW FURTHER WEST MONDAY AND MONDAY NIGHT THAN THE ECMWF WHICH COULD RESULT IN THE POTENTIAL FOR SOME ADDITIONAL SHOWER ACTIVITY. AT THIS TIME...WILL SKEW FORECAST TOWARDS THE ECMWF FOR MONDAY/MONDAY NIGHT...AND KEEP POPS BELOW MENTIONABLE LEVELS. MORE SIGNIFICANT ISSUE FOR THE EXTENDED WILL BE THE POTENTIAL FOR OFFSHORE WINDS AS WELL AS WARM/DRY CONDITIONS. FOR MONDAY NIGHT...THE NORTHERLY FLOW ACROSS SOUTHERN SANTA BARBARA COUNTY MAY BE STRONG ENOUGH TO REACH ADVISORY LEVELS. BY TUESDAY MORNING...THE FLOW WILL TURN NORTHEASTERLY AND REMAIN THAT WAY THROUGH THURSDAY. BOTH THE GFS AND ECMWF INDICATE DECENT LOW LEVEL WIND SUPPORT...WITH THE BEST SUPPORT (950 MB WINDS 15-25 KT...850 MB WINDS 20-30 KT) ON WEDNESDAY. WIND SPEEDS OF THIS MAGNITUDE ON THESE MODELS IS QUITE IMPRESSIVE THAT FAR OUT IN TIME...SO IT WILL BE INTERESTING TO SEE HOW THINGS DEVELOP WHEN NEXT WEEK FALLS INTO THE HIGH-RES MODEL WINDOW. HOWEVER...GIVEN THE FORECASTED STRONG OFFSHORE GRADIENT AND DECENT UPPER LEVEL WIND SUPPORT...THE POSSIBILITY EXISTS FOR ADVISORY LEVEL SANTA ANA WINDS TUESDAY AND WEDNESDAY...WITH THE BEST CHANCES ON WEDNESDAY. WITH THE DEVELOPING OFFSHORE FLOW...AND HIGH PRESSURE BUILDING IN ALOFT...TEMPERATURES WILL BE ON THE UPSWING THROUGH THE PERIOD WITH AS FOR THE WARM AND DRY POTENTIAL...WITH WEDNESDAY/THURSDAY LIKELY THE WARMEST DAYS. ADDITIONALLY...THE OFFSHORE FLOW AND WARM TEMPERATURES WILL RESULT IN LOW RELATIVE HUMIDITY...WHICH WILL CONSPIRE TO BRING A HEIGHTENED FIRE WEATHER RISK TO THE AREA...AND POSSIBLY CRITICAL FIRE WEATHER CONDITIONS TO PARTS OF VENTURA AND LOS ANGELES COUNTIES. && .AVIATION...16/12Z. AT 11Z AT KLAX... THE INVERSION WAS ABOUT 500 FEET DEEP. THE TOP OF THE INVERSION WAS NEAR 2500 FEET WITH A TEMPERATURE OF 18 DEGREES CELSIUS. OVERALL... MODERATE CONFIDENCE IN THE 12Z TAFS. IFR/MVFR CONDITIONS AT COASTAL AND ADJACENT VALLEY SITES WILL CLEAR 16Z-18Z THEN REDEVELOP AFTER 05Z. THUNDERSTORMS ARE EXPECTED IN THE ANTELOPE VALLEY 22Z-04Z. OTHERWISE AND ELSEWHERE VFR CONDITIONS WILL PREVAIL. KLAX... MODERATE CONFIDENCE IN THE 12Z TAF. IFR/MVFR CONDITIONS WILL CLEAR 16Z-18Z THEN REDEVELOP AFTER 05Z. OTHERWISE VFR CONDITIONS WILL PREVAIL. KBUR... MODERATE CONFIDENCE IN THE 12Z TAF. IFR/MVFR CONDITIONS WILL CLEAR 16Z-17Z THEN REDEVELOP AFTER 05Z. OTHERWISE VFR CONDITIONS WILL PREVAIL. && .MARINE...16/900 AM... MODERATE CONFIDENCE IN LOW GRADE SMALL CRAFT ADVISORY CONDITIONS TONIGHT NORTH OF SAN NICOLAS ISLAND BEYOND 10 NM FROM SHORE. HIGH CONFIDENCE IN SMALL CRAFT CONDITIONS WITH WINDS TO AROUND 30 KT SATURDAY THROUGH EARLY NEXT WEEK. 30 PERCENT CHANCE OF GALE CONDITIONS MONDAY NIGHT. THESE WINDS COULD IMPACT THE WESTERN SBA CHANNEL AS WELL. THESE WINDS WILL ALSO CREATE CHOPPY SEAS NORTH OF SAN ONOFRE...INCREASING EACH DAY THROUGH MONDAY. NO THUNDERSTORMS EXPECTED OVER THE COASTAL WATERS AT THIS TIME. && .LOX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH (SEE LAXFFALOX). SMALL CRAFT ADVISORY (SEE LAXMWWLOX). && $$ PUBLIC...MW/RAT AVIATION...KJ MARINE...RK SYNOPSIS...RAT WWW.WEATHER.GOV/LOSANGELES
Area Forecast Discussion National Weather Service Sacramento CA 922 AM PDT FRI OCT 16 2015 .SHORT TERM DISCUSSION... SYNOPSIS... Cooling with a chance of a few showers over the Sierra Nevada today. Cloudy with showers and a slight chance of thunderstorms Saturday most of northern California with below normal temperatures. Showers shifting eastward Sunday. Dry with return to above normal temperatures Monday through mid week. && .Discussion Still looking like some showers are in store for the area today and tomorrow. Current radar showing some returns still in portions of western Stanislaus county and also some weak returns in the Sierra. NAM and HRRR both showing a fair amount of showers developing this afternoon in Sierra and have raised up pops for this. System tomorrow still on track as well and looks like there should be some showers with the most organized activity coming through in the afternoon in the northern Sacramento Valley. This scenario covered well in grids but will prepare some additional content to better communicate the timing of this activity later this morning. Rasch .Previous Discussion An upper level low continues to spin over the central California coast and has moved little over the last 24 hours. A disturbance rotating around this low may bring a few light showers to the far southern CWA in but this disturbance should rotate out of the area by sunrise. A low pressure area in the Gulf of Alaska will help to start pushing the low inland today. Southeast flow aloft and instability will bring a threat of showers or thunderstorms to the Sierra this afternoon. The upper low is forecast to push into the Pacific Northwest and northern California on Saturday bringing a chance of precipitation to most of the north state. Cape progs from both the NAM and GFS show enough instability for a threat of thunderstorms on Saturday as well so have expanded slight thunderstorm threat to all areas. The overall airmass cools significantly on Saturday and combined with cloud cover should actually bring down daytime highs to below normal. Overall QPF is not all that large but TPW feeding into this system progged at over an inch so some thunderstorms could contain heavier rainfall. Precipitation threat shifts eastward on Sunday as the upper trough axis shifts to over the Sierra. Cooler air digging into the back side of the low will make Sunday an even cooler day than Saturday. Upper ridging begins building in on Monday for warmer temperatures with highs for the day expected to climb back up closer to or a little above normal. Northerly flow aloft and a fairly tight northerly surface gradient (8-10 mb from MFR to SAC) will bring breezy north winds on Monday. && .EXTENDED DISCUSSION (Tuesday THROUGH Friday) The extended forecast looks like a period of change. Tuesday may be the warmest day of the week, with high pressure rebuilding over the area bringing above normal temperatures and dry weather. North winds are looking increasingly breezy through Tuesday, and there is some potential that they could reach Wind Advisory levels. This along with low humidity could bring elevated fire weather concerns for some areas, such as the western side of the Valley and into Lake County during the day, spreading to northeast winds into the Sierra Tuesday night into early Wednesday. High pressure ridging weakens a little on Wednesday, with slightly lower temperatures and lighter northerly winds. An approaching Pacific shortwave trough is now looking a little slower, spreading inland Thursday and Thursday night. A stronger and potentially wetter system follows close behind, but models are unclear about the details of this system. The European model has made a significant change with the latest run, bringing a deeper digging trough through California Friday and Saturday. The GFS model is more consistent with previous runs, showing a system passing further north through Northern California late Friday. Have blended these latest runs, introducing a slight chance of rain showers Friday and Saturday, mainly in the mountains. Will have to watch this system to see how it evolves for a better idea of where and when there could be some precipitation. At this point, it doesn`t look very wet. It does look like it will bring some weekend temperatures cooling to more normal levels. EK && .AVIATION... Mainly VFR conditions today for TAF sites, though a few sprinkles of light showers are possible through 12z in the northern San Joaquin Valley. Some showers and afternoon/evening thunderstorms are possible over the northern Sierra and southern Cascades. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1055 PM PDT THU OCT 15 2015 .SYNOPSIS...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS REMAIN A POSSIBILITY THROUGH THURSDAY NIGHT...MAINLY FROM THE SOUTHERN DIABLO RANGE SOUTH INTO MONTEREY AND SAN BENITO COUNTIES. PRECIPITATION MAY LINGER ACROSS THE FAR SOUTHEASTERN PART OF THE FORECAST AREA INTO FRIDAY. OTHERWISE DRY WEATHER AND SLIGHTLY COOLER TEMPERATURES ARE FORECAST FOR FRIDAY. ANOTHER WEATHER SYSTEM APPROACHING FROM THE WEST WILL BRING A CHANCE OF PRECIPITATION FROM LATE FRIDAY NIGHT INTO SATURDAY...MAINLY ACROSS THE NORTH BAY. && .DISCUSSION...AS OF 9:05 PM PDT THURSDAY...AN UPPER LOW CURRENTLY CENTERED NEAR THE SLO/SANTA BARBARA COUNTY COASTLINE CONTINUES TO PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS INLAND PORTIONS OF CENTRAL AND SOUTHERN CALIFORNIA. A LINE OF LIGHT SHOWERS MOVED THROUGH THE NORTH BAY FROM LATE AFTERNOON THROUGH EARLY EVENING...BUT OTHERWISE THERE HAD BEEN A BREAK IN THE PRECIPITATION ACTION ACROSS OUR FORECAST AREA EARLY THIS EVENING. THAT IS NOW CHANGING. AN AREA OF THUNDERSTORMS OVER THE SAN JOAQUIN VALLEY HAS BEEN MOVING SLOWLY TO THE WEST-NORTHWEST AND IS CURRENTLY BEGINNING TO SPREAD INTO SOUTHERN SAN BENITO COUNTY AND SOUTHEAST MONTEREY COUNTY. ALSO...SHOWERS HAVE ALSO RECENTLY DEVELOPED NEAR THE SOUTHERN BIG SUR COAST. PREVIOUSLY THE MODELS HAD INDICATED ALL PRECIP WOULD END IN OUR AREA BY LATE THIS EVENING. BUT LATEST NAM AND GFS MODELS SUGGEST SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ACROSS MONTEREY AND SAN BENITO COUNTIES THROUGH THE NIGHT. IN ADDITION...THE HRRR MODEL SHOWS BANDS OF CONVECTIVE PRECIP REACHING FARTHER NORTH INTO SANTA CLARA AND SANTA CRUZ COUNTIES LATER TONIGHT. GIVEN LATEST SATELLITE AND RADAR DATA...BELIEVE THE HRRR MAY HAVE THE RIGHT IDEA HERE. A FORECAST UPDATE EARLIER THIS EVENING INCLUDED EXPANDING SHOWER AND THUNDERSTORM CHANCES ACROSS MORE OF THE SOUTHEASTERN PORTION OF OUR FORECAST AREA...AND ALSO EXTENDING THOSE CHANCES THROUGH THE NIGHT INSTEAD OF LIMITING THEM TO THE EVENING HOURS. SOME MODEL OUTPUT INDICATE LINGERING CONVECTIVE PRECIP ON INTO FRIDAY...PUT MAINLY OVER SCATTERED PORTIONS OF MONTEREY AND SAN BENITO COUNTIES. THE REMAINDER OF OUR FORECAST AREA SHOULD BE DRY ON FRIDAY. HIGH TEMPERATURES ON FRIDAY ARE EXPECTED TO BE SLIGHTLY COOLER THAN TODAY DUE TO A MODEST UPTICK IN ONSHORE FLOW AND SLIGHT COOLING ALOFT. THE NEXT WEATHER SYSTEM...CURRENTLY OVER THE EASTERN PACIFIC ALONG 135W...IS FORECAST TO APPROACH THE NORTHERN CALIFORNIA COAST BY LATE TOMORROW NIGHT OR SATURDAY MORNING. MOST MODEL OUTPUT INDICATES LIGHT RAIN WILL SPREAD INTO THE NORTH BAY BY SATURDAY MORNING...AND PERHAPS INTO NORTH BAY COASTAL AREAS BY LATE FRIDAY NIGHT. POPS ARE CURRENTLY NO HIGHER THAN SLIGHT CHANCE AND WE MAY NEED TO BOOST THOSE A BIT IN THE NORTH BAY GIVEN CURRENT MODEL CONSENSUS. IN ADDITION...THE MODELS AGREE THAT THE WEEKEND SYSTEM WILL DEVELOP A CLOSED LOW NEAR THE NORTHERN CA COAST ON SATURDAY EVENING AND THEN DIG THAT LOW TO THE SOUTH OR SOUTHEAST ON SATURDAY NIGHT AND SUNDAY. THIS MAY RESULT IN SOME SHOWER ACTIVITY FARTHER TO THE SOUTH BY SATURDAY AFTERNOON AND EVENING...ESPECIALLY FOR INLAND PORTIONS OF OUR FORECAST AREA. BOTH THE NAM AND GFS DEVELOP ISOLATED LIGHT PRECIP OVER PORTIONS OF OUR FORECAST AREA ON THE BACK SIDE OF THE UPPER LOW ON SATURDAY NIGHT AND SUNDAY. BUT FOR MOST OF OUR AREA...THESE TWO MODELS FORECAST DRY WEATHER FOR SATURDAY NIGHT AND SUNDAY. HOWEVER...THE 12Z CANADIAN MODEL DROPS THE LOW ALMOST DUE SOUTH AND FORECASTS SCATTERED LIGHT PRECIP ACROSS MUCH OF OUR FORECAST AREA THROUGH SUNDAY. WILL DISCOUNT THE 12Z CANADIAN FOR NOW...BUT THE DRY FORECAST FOR SUNDAY DOES CONTAIN SOME UNCERTAINTY. THE MEDIUM RANGE MODELS MOSTLY AGREE THAT AN UPPER RIDGE WILL MAINTAIN DRY AND MILD WEATHER FOR MOST OF NEXT WEEK. .&& .AVIATION...AS OF 10:45 PM PDT THURSDAY...UPPER LOW SOUTH OF THE FORECAST AREA CONTINUES TO SPREAD MID AND HIGH CLOUDS OVER THE AREA. RADAR IS PICKING UP LIGHT PRECIPITATION SOUTH OF THE MRY BAY AREA BUT THIS ACTIVITY WILL DIMINISH AFTER MIDNIGHT. LOW CLOUDS MOVED INTO THE MRY BAY AREA EARLY THIS EVENING BUT HAS SINCE MIXED OUT. CIGS CURRENTLY OVER HAF AND THE CITY OF SAN FRANCISCO. ONSHORE FLOW SHOULD HELP SPREAD THESE CLOUDS INTO THE SFO AND MRY BAY AREAS LATER TONIGHT. VICINITY OF KSFO...MVFR CIGS AFTER 12Z. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...IFR CIGS AFTER 10Z. CONFIDENCE IS NOT HIGH AS INSTABILITY OVER THE AREA MAY KEEP THE LOWER LEVELS MIXED OUT. && .MARINE...AS OF 10:45 PM PDT THURSDAY...AN UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE INLAND TONIGHT. HIGH PRESSURE WILL SLOWLY BUILD OFF THE CALIFORNIA COAST THURSDAY AND FRIDAY. NORTHWEST WINDS WILL INCREASE FRIDAY THROUGH MONDAY. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...NONE. $$ PUBLIC FORECAST: DYKEMA AVIATION: W PI MARINE: SIMS 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 NEW YORK NY
458 AM EDT FRI OCT 16 2015 .SYNOPSIS... A COLD FRONT PASSES THROUGH TODAY. A LARGE AREA OF HIGH PRESSURE BUILDS TO THE WEST THROUGH SATURDAY. THIS CANADIAN HIGH PRESSURE BUILDS OVER THE REGION SUNDAY THROUGH EARLY NEXT WEEK. THE HIGH MOVES TO THE SOUTH AND EAST THE MIDDLE OF THE WEEK. A FRONTAL SYSTEM MAY APPROACH FROM THE WEST LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SHORTWAVE TROUGH/PVA PASSES ACROSS NEW ENGLAND THIS MORNING. SFC LOW PRESSURE REMAINS CLUSTERED BY MODELS AS IT TRACKS ACROSS NORTHERN NEW ENGLAND THIS MORNING...WITH A COLD FRONT PASSING ACROSS THE AREA BY 11-15Z. LIMITED MOISTURE AND WEAK LIFT WILL ONLY RESULT IN WIDELY SCATTERED SHOWERS THIS MORNING ALONG AND AHEAD OF THE FRONT. PERHAPS SOME WEAK CAPE FURTHER EAST COULD RESULT IN SLIGHT INTENSIFICATION AND INCREASE IN THE SHOWERS ACROSS EXTREME EAST ZONES...BUT THAT REMAINS UNCLEAR. LATEST HRRR NOT OVERLY AGGRESSIVE WITH ANY OF THE CONVECTIVE SHOWERS. BY AFTERNOON...UPPER SHORTWAVE/PVA MOVES EAST WITH DRIER AIR ADVECTING IN FROM THE WEST IN WESTERLY DOWNSLOPE FLOW. SUNSHINE RETURNS...AND THE DOWNSLOPE FLOW WILL AID TEMPS TO SLIGHTLY ABOVE SEASONAL NORMS. FOLLOWED A MOS BLEND FOR TODAY/S HIGH/S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... YET ANOTHER SHORTWAVE/PVA PIVOTS AROUND THE BASE OF TROUGH. IT APPEARS THAT THIS SHORTWAVE WILL MOVE THROUGH TONIGHT. SFC COLD FRONT TRACKS ACROSS THE AREA TONIGHT. WILL MAINTAIN DRY FORECAST...ALTHOUGH AN ISOLATED SHOWER IS NOT OUT OF THE QUESTION. CANADIAN AIR USHERS IN BEHIND THE FRONT SATURDAY...WITH STRONG CAA ENSURING COOLEST TEMPS OF THE SEASON. GUSTY NW FLOW IS EXPECTED AS THE PRESSURE GRADIENT TIGHTENS BEHIND THE FRONT...AND OUT AHEAD OF STRONG HIGH PRESSURE TO THE WEST. VARYING AMOUNTS OF CLOUDS ARE EXPECTED TONIGHT AND SATURDAY DUE TO WEAK MID/UPPER LEVEL LIFT. TEMPS TONIGHT WILL BE CHILLY...BUT DO NOT FORESEE WIDESPREAD FROST DEVELOPMENT ACROSS THE INTERIOR. MOS TEMPS BORDERLINE...AND PATCHY CLOUDS SHOULD PRECLUDE WIDESPREAD DEVELOPMENT TONIGHT. TEMPS ON SATURDAY WILL LIKELY RUN ABOUT 10 DEGREES LOWER THAN FRIDAY TEMPS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AN ANOMALOUSLY DEEP LONGWAVE TROUGH WILL BE SITUATED OVER THE NORTHEAST ON SUNDAY...AND THEN MOVE OFFSHORE ON MONDAY. 500 HPA HEIGHTS ARE MODELED TO FALL TO 2 TO 3 STANDARD DEVIATIONS BELOW CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR ON SUNDAY. AT 850 HPA...TEMPERATURES ARE PROGGED BY THE MODELS TO FALL TO BETWEEN -6C AND -9C. THESE VALUES ARE CLOSE TO 15C BELOW CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR. WITH OF ALL OF THIS IN MIND...A CHILLY PERIOD OF WEATHER IS LIKELY TO OCCUR ACROSS THE AREA FROM SATURDAY NIGHT THROUGH MONDAY. AS THE COLD AIR MASS WORKS ITS WAY INTO THE REGION SATURDAY NIGHT...THE FIRST FREEZE OF THE SEASON BECOMES LIKELY ACROSS INTERIOR ZONES. PER COLLABORATION WITH NEIGHBORING OFFICES...WILL HOLD OFF ON ISSUING A FREEZE WATCH...BUT WILL LIKELY NEED TO BE ISSUED IN THE NEXT FORECAST PACKAGE THIS AFTERNOON. CANADIAN HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST SUNDAY. A STRONG SHORTWAVE DIVING SOUTH TOWARDS THE AREA ON THE BACKSIDE OF THE LONGWAVE TROUGH COULD DEVELOP A SHOWER OR TWO LATE IN THE DAY ACROSS WESTERN ZONES. THE REGION WILL ALSO BRIEFLY LIE NEAR THE LEFT EXIT REGION OF 130+ KT JET ON THE BACKSIDE OF THE TROUGH. WILL CARRY SLIGHT CHANCE POPS BETWEEN ABOUT 18Z SUN TO 00Z MON. THE SHORTWAVE QUICKLY MOVES OFF TO THE EAST SUNDAY NIGHT AS THE MAIN LONGWAVE TROUGH AXIS SHIFTS OFFSHORE. HIGH TEMPERATURES ON SUNDAY WILL STRUGGLE TO REACH 50 DEGREES. AN EVEN COLDER NIGHT IS LIKELY SUNDAY NIGHT AS THE CENTER OF THE HIGH PRESSURE BUILDS OVERHEAD. WINDS SHOULD LIGHTEN ESPECIALLY AWAY FROM THE IMMEDIATE COAST. LOWS IN THE UPPER 20S TO THE LOWER AND MIDDLE 30S ARE FORECAST. AT THIS TIME IT APPEARS COASTAL CONNECTICUT...LONG ISLAND...AND NEW YORK CITY METRO SHOULD STAY JUST ABOVE FREEZING. HEIGHTS BEGIN TO RISE MONDAY AS MIDDLE AND UPPER LEVEL RIDGING BUILDS OVER THE AREA. THE SURFACE HIGH WILL ALSO BEGIN TO SHIFT TO THE SOUTH. SOME MODERATION IN TEMPERATURES ON MONDAY ARE FORECAST BUT READINGS WILL STILL BE WELL BELOW SEASONABLE LEVELS. A WARM ADVECTION PATTERN THEN TAKES SHAPE MONDAY NIGHT INTO TUESDAY WITH SW FLOW IN THE LOW LEVELS AND 850 HPA TEMPS RISING CLOSE TO 10C BY TUESDAY AFTERNOON. HIGH TEMPERATURES WILL RISE BACK TO NEAR SEASONABLE LEVELS FOR TUESDAY. A MID LEVEL SHORTWAVE PASSES WELL TO THE NORTH SO CONDITIONS SHOULD CONTINUE TO REMAIN DRY TUESDAY. RIDGING BUILDS ALOFT AGAIN ON WEDNESDAY WITH HIGH PRESSURE JUST OFFSHORE ALLOWING TEMPERATURES TO WARM SLIGHTLY ABOVE NORMAL. A FRONTAL SYSTEM ASSOCIATED WITH ANOTHER MID LEVEL SHORTWAVE WITHIN THE NORTHERN JET STREAM MAY APPROACH LATE IN THE WEEK. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... A FAST MOVING COLD FRONT WILL MOVE THROUGH THE TERMINALS THIS MORNING FROM 10Z-13Z. EXPECT MAINLY VFR CONDITIONS WITH A BRIEF SHOWER POSSIBLE AS THE FRONT PASSES. FORECAST CHALLENGE WILL BE THE TIMING OF THE NW WIND GUSTS AS WELL AS MAGNITUDE. DEEP MIXING TODAY SHOULD ALLOW GUSTS TO HANG ON THROUGH FIRST HALF OF AFT. IN ADDITION...THERE COULD BE A BRIEF STRONG GUST UP TO 25 KT AHEAD OF THE FRONT THIS MORNING. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: TIMING OF GUSTS...BOTH THE ONSET AND ENDING MAY BE 1-2 HOURS EARLIER. KLGA FCSTER COMMENTS: TIMING OF GUSTS...BOTH THE ONSET AND ENDING MAY BE 1-2 HOURS EARLIER. KEWR FCSTER COMMENTS: TIMING OF GUSTS...BOTH THE ONSET AND ENDING MAY BE 1-2 HOURS EARLIER. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: TIMING OF GUSTS...BOTH THE ONSET AND ENDING MAY BE 1-2 HOURS EARLIER. KHPN FCSTER COMMENTS: TIMING OF GUSTS...BOTH THE ONSET AND ENDING MAY BE 1-2 HOURS EARLIER. KISP FCSTER COMMENTS: TIMING OF GUSTS...BOTH THE ONSET AND ENDING MAY BE 1-2 HOURS EARLIER. .OUTLOOK FOR 06Z SAT THROUGH TUESDAY... .SAT-SUN...VFR. NW WINDS G20-25KT. .MON-TUE...VFR. && .MARINE... AS A COLD FRONT MOVES THROUGH EARLY THIS MORNING...WINDS WILL GUST TO 25 KTS OR HIGHER OVER THE OCEAN WATERS. A BRIEF OR OCCASIONAL GUST TO 25 KTS CANNOT BE RULED OUT FOR NON OCEAN WATERS THIS MORNING. HOWEVER...NOT FREQUENT ENOUGH...OR AN ADEQUATE LONG DURATION FOR ISSUANCE OF AN SCA FOR THOSE NON OCEAN WATERS. WINDS ARE EXPECTED TO DIMINISH SOMEWHAT THIS AFTERNOON BEHIND THE FRONT. ANOTHER FRONT WILL MOVE THROUGH TONIGHT. THEN...THE PRESSURE GRADIENT TIGHTENS FOR SATURDAY. AS SUCH...LIGHTER WINDS TONIGHT INCREASE SATURDAY IN A GUSTY NW FLOW. WILL MAINTAIN CURRENT SCA FOR THE OCEAN WATERS FOR BORDERLINE WINDS THIS MORNING...AND BUILDING SEAS CLOSE TO 5 FEET. ALL WATERS WILL LIKELY EXPERIENCE SCA CONDITIONS SATURDAY...BUT WILL WAIT UNTIL CURRENT HEADLINE IS NO LONGER NEEDED. SCA CONDITIONS ARE LIKELY ON THE OCEAN SATURDAY NIGHT INTO SUNDAY MORNING WINDS GUSTING AROUND 25 KT. THE PRESSURE GRADIENT WILL THEN RELAX ALLOWING CONDITIONS TO FALL BELOW SCA LEVELS FROM SUNDAY THROUGH MONDAY. SCA WINDS AND SEAS ARE POSSIBLE ON TUESDAY AS HIGH PRESSURE SHIFTS SOUTH OF THE WATERS AND THE PRESSURE GRADIENT INCREASES. && .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE FORECAST PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353- 355. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ350. && $$ SYNOPSIS...DS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...DS AVIATION...DW MARINE...DS/PW HYDROLOGY...DS/PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
323 AM EDT FRI OCT 16 2015 .SYNOPSIS... A COLD FRONT PASSES THROUGH TODAY. A LARGE AREA OF HIGH PRESSURE BUILDS TO THE WEST THROUGH SATURDAY. THIS CANADIAN HIGH PRESSURE BUILDS OVER THE REGION SUNDAY THROUGH EARLY NEXT WEEK. THE HIGH MOVES TO THE SOUTH AND EAST THE MIDDLE OF THE WEEK. A FRONTAL SYSTEM MAY APPROACH FROM THE WEST LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SHORTWAVE TROUGH/PVA PASSES ACROSS NEW ENGLAND THIS MORNING. SFC LOW PRESSURE REMAINS CLUSTERED BY MODELS AS IT TRACKS ACROSS NORTHERN NEW ENGLAND THIS MORNING...WITH A COLD FRONT PASSING ACROSS THE AREA BY 11-15Z. LIMITED MOISTURE AND WEAK LIFT WILL ONLY RESULT IN WIDELY SCATTERED SHOWERS THIS MORNING ALONG AND AHEAD OF THE FRONT. PERHAPS SOME WEAK CAPE FURTHER EAST COULD RESULT IN SLIGHT INTENSIFICATION AND INCREASE IN THE SHOWERS ACROSS EXTREME EAST ZONES...BUT THAT REMAINS UNCLEAR. LATEST HRRR NOT OVERLY AGGRESSIVE WITH ANY OF THE CONVECTIVE SHOWERS. BY AFTERNOON...UPPER SHORTWAVE/PVA MOVES EAST WITH DRIER AIR ADVECTING IN FROM THE WEST IN WESTERLY DOWNSLOPE FLOW. SUNSHINE RETURNS...AND THE DOWNSLOPE FLOW WILL AID TEMPS TO SLIGHTLY ABOVE SEASONAL NORMS. FOLLOWED A MOS BLEND FOR TODAY/S HIGH/S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... YET ANOTHER SHORTWAVE/PVA PIVOTS AROUND THE BASE OF TROUGH. IT APPEARS THAT THIS SHORTWAVE WILL MOVE THROUGH TONIGHT. SFC COLD FRONT TRACKS ACROSS THE AREA TONIGHT. WILL MAINTAIN DRY FORECAST...ALTHOUGH AN ISOLATED SHOWER IS NOT OUT OF THE QUESTION. CANADIAN AIR USHERS IN BEHIND THE FRONT SATURDAY...WITH STRONG CAA ENSURING COOLEST TEMPS OF THE SEASON. GUSTY NW FLOW IS EXPECTED AS THE PRESSURE GRADIENT TIGHTENS BEHIND THE FRONT...AND OUT AHEAD OF STRONG HIGH PRESSURE TO THE WEST. VARYING AMOUNTS OF CLOUDS ARE EXPECTED TONIGHT AND SATURDAY DUE TO WEAK MID/UPPER LEVEL LIFT. TEMPS TONIGHT WILL BE CHILLY...BUT DO NOT FORESEE WIDESPREAD FROST DEVELOPMENT ACROSS THE INTERIOR. MOS TEMPS BORDERLINE...AND PATCHY CLOUDS SHOULD PRECLUDE WIDESPREAD DEVELOPMENT TONIGHT. TEMPS ON SATURDAY WILL LIKELY RUN ABOUT 10 DEGREES LOWER THAN FRIDAY TEMPS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AN ANOMALOUSLY DEEP LONGWAVE TROUGH WILL BE SITUATED OVER THE NORTHEAST ON SUNDAY...AND THEN MOVE OFFSHORE ON MONDAY. 500 HPA HEIGHTS ARE MODELED TO FALL TO 2 TO 3 STANDARD DEVIATIONS BELOW CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR ON SUNDAY. AT 850 HPA...TEMPERATURES ARE PROGGED BY THE MODELS TO FALL TO BETWEEN -6C AND -9C. THESE VALUES ARE CLOSE TO 15C BELOW CLIMATOLOGICAL NORMAL FOR THIS TIME OF YEAR. WITH OF ALL OF THIS IN MIND...A CHILLY PERIOD OF WEATHER IS LIKELY TO OCCUR ACROSS THE AREA FROM SATURDAY NIGHT THROUGH MONDAY. AS THE COLD AIR MASS WORKS ITS WAY INTO THE REGION SATURDAY NIGHT...THE FIRST FREEZE OF THE SEASON BECOMES LIKELY ACROSS INTERIOR ZONES. PER COLLABORATION WITH NEIGHBORING OFFICES...WILL HOLD OFF ON ISSUING A FREEZE WATCH...BUT WILL LIKELY NEED TO BE ISSUED IN THE NEXT FORECAST PACKAGE THIS AFTERNOON. CANADIAN HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST SUNDAY. A STRONG SHORTWAVE DIVING SOUTH TOWARDS THE AREA ON THE BACKSIDE OF THE LONGWAVE TROUGH COULD DEVELOP A SHOWER OR TWO LATE IN THE DAY ACROSS WESTERN ZONES. THE REGION WILL ALSO BRIEFLY LIE NEAR THE LEFT EXIT REGION OF 130+ KT JET ON THE BACKSIDE OF THE TROUGH. WILL CARRY SLIGHT CHANCE POPS BETWEEN ABOUT 18Z SUN TO 00Z MON. THE SHORTWAVE QUICKLY MOVES OFF TO THE EAST SUNDAY NIGHT AS THE MAIN LONGWAVE TROUGH AXIS SHIFTS OFFSHORE. HIGH TEMPERATURES ON SUNDAY WILL STRUGGLE TO REACH 50 DEGREES. AN EVEN COLDER NIGHT IS LIKELY SUNDAY NIGHT AS THE CENTER OF THE HIGH PRESSURE BUILDS OVERHEAD. WINDS SHOULD LIGHTEN ESPECIALLY AWAY FROM THE IMMEDIATE COAST. LOWS IN THE UPPER 20S TO THE LOWER AND MIDDLE 30S ARE FORECAST. AT THIS TIME IT APPEARS COASTAL CONNECTICUT...LONG ISLAND...AND NEW YORK CITY METRO SHOULD STAY JUST ABOVE FREEZING. HEIGHTS BEGIN TO RISE MONDAY AS MIDDLE AND UPPER LEVEL RIDGING BUILDS OVER THE AREA. THE SURFACE HIGH WILL ALSO BEGIN TO SHIFT TO THE SOUTH. SOME MODERATION IN TEMPERATURES ON MONDAY ARE FORECAST BUT READINGS WILL STILL BE WELL BELOW SEASONABLE LEVELS. A WARM ADVECTION PATTERN THEN TAKES SHAPE MONDAY NIGHT INTO TUESDAY WITH SW FLOW IN THE LOW LEVELS AND 850 HPA TEMPS RISING CLOSE TO 10C BY TUESDAY AFTERNOON. HIGH TEMPERATURES WILL RISE BACK TO NEAR SEASONABLE LEVELS FOR TUESDAY. A MID LEVEL SHORTWAVE PASSES WELL TO THE NORTH SO CONDITIONS SHOULD CONTINUE TO REMAIN DRY TUESDAY. RIDGING BUILDS ALOFT AGAIN ON WEDNESDAY WITH HIGH PRESSURE JUST OFFSHORE ALLOWING TEMPERATURES TO WARM SLIGHTLY ABOVE NORMAL. A FRONTAL SYSTEM ASSOCIATED WITH ANOTHER MID LEVEL SHORTWAVE WITHIN THE NORTHERN JET STREAM MAY APPROACH LATE IN THE WEEK. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... A FAST MOVING COLD FRONT WILL MOVE THROUGH THE TERMINALS THIS MORNING FROM 10Z-13Z. EXPECT MAINLY VFR CONDITIONS WITH A BRIEF SHOWER POSSIBLE AS THE FRONT PASSES. FORECAST CHALLENGE WILL BE THE TIMING OF THE NW WIND GUSTS AS WELL AS MAGNITUDE. DEEP MIXING TODAY SHOULD ALLOW GUSTS TO HANG ON THROUGH FIRST HALF OF AFT. IN ADDITION...THERE COULD BE A BRIEF STRONG GUST UP TO 25 KT AHEAD OF THE FRONT THIS MORNING. .OUTLOOK FOR 06Z SAT THROUGH TUESDAY... .SAT-SUN...VFR. NW WINDS G20-25KT. .MON-TUE...VFR. && .MARINE... AS A COLD FRONT MOVES THROUGH EARLY THIS MORNING...WINDS WILL GUST TO 25 KTS OR HIGHER OVER THE OCEAN WATERS. A BRIEF OR OCCASIONAL GUST TO 25 KTS CANNOT BE RULED OUT FOR NON OCEAN WATERS THIS MORNING. HOWEVER...NOT FREQUENT ENOUGH...OR AN ADEQUATE LONG DURATION FOR ISSUANCE OF AN SCA FOR THOSE NON OCEAN WATERS. WINDS ARE EXPECTED TO DIMINISH SOMEWHAT THIS AFTERNOON BEHIND THE FRONT. ANOTHER FRONT WILL MOVE THROUGH TONIGHT. THEN...THE PRESSURE GRADIENT TIGHTENS FOR SATURDAY. AS SUCH...LIGHTER WINDS TONIGHT INCREASE SATURDAY IN A GUSTY NW FLOW. WILL MAINTAIN CURRENT SCA FOR THE OCEAN WATERS FOR BORDERLINE WINDS THIS MORNING...AND BUILDING SEAS CLOSE TO 5 FEET. ALL WATERS WILL LIKELY EXPERIENCE SCA CONDITIONS SATURDAY...BUT WILL WAIT UNTIL CURRENT HEADLINE IS NO LONGER NEEDED. SCA CONDITIONS ARE LIKELY ON THE OCEAN SATURDAY NIGHT INTO SUNDAY MORNING WINDS GUSTING AROUND 25 KT. THE PRESSURE GRADIENT WILL THEN RELAX ALLOWING CONDITIONS TO FALL BELOW SCA LEVELS FROM SUNDAY THROUGH MONDAY. SCA WINDS AND SEAS ARE POSSIBLE ON TUESDAY AS HIGH PRESSURE SHIFTS SOUTH OF THE WATERS AND THE PRESSURE GRADIENT INCREASES. && .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE FORECAST PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353- 355. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ350. && $$ SYNOPSIS...DS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...DS AVIATION...DW MARINE...DS/PW HYDROLOGY...DS/PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
213 AM EDT FRI OCT 16 2015 .SYNOPSIS... A COLD FRONT APPROACHES OVERNIGHT AND PASSES THROUGH FRIDAY MORNING. A LARGE AREA OF HIGH PRESSURE THEN BUILDS OVER THE REGION FOR THE WEEKEND AND MOVES OFFSHORE BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... CLOUDS WILL BE ON THE INCREASE EARLY THIS MORNING FROM WEST TO EAST WITH THE APPROACH OF A COLD FRONT. MOISTURE IS LIMITED...SO THINKING IS THAT THERE WILL BE ONLY A SLIGHT CHANCE OF A SHOWER AFTER 3 OR 4AM FOR FAR NORTHERN AND WESTERN ZONES AND TOWARDS DAYBREAK FOR POINTS EAST. LATEST HRRR CONCURS WITH LOW COVERAGE. MAV/NAM MOS BLEND WAS USED FOR LOW TEMPS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... COLD FRONT MOVES THROUGH DURING THE FIRST HALF OF FRIDAY MORNING WITH ONLY A SLIGHT CHANCE OF A SHOWER. THE SLIGHT EXCEPTION MAY BE FAR EASTERN ZONES WITH SOMEWHAT HIGHER INSTABILITY FOR THESE AREAS WITH A CHANCE OF SHOWERS... WHICH SHOULD BE OVER BY LATE MORNING. CLOUDS DIMINISH BEHIND THE FRONT...AND A MODERATE WESTERLY DOWNSLOPE FLOW SHOULD HELP HIGH TEMPERATURES REACH SLIGHTLY ABOVE NORMAL. WEAK HIGH PRESSURE WILL BE IN PLACE FRIDAY NIGHT WITH A SURFACE COLD FRONT MOVING IN FROM THE NORTHWEST. MOISTURE LOOKS TOO LIMITED FOR A MENTION OF A POSSIBLE SHOWER...SO WILL MAINTAIN A DRY FORECAST. LOCALIZED FROST NOT OUT OF THE QUESTION FOR SOME OF THE NORTHERN SUBURBS...BUT WITH FCST LOWS IN THE MID-UPPER 30S AND THE POTENTIAL OF A MOSTLY CLOUDY SKY...WILL NOT INCLUDE THIS IN THE FORECAST AT THIS TIME. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGH PRES BUILDS IN FROM THE NORTH AND WEST THIS WEEKEND WITH SOME OF THE COLDEST TEMPS OF THE FALL. WIDESPREAD SUB-FREEZING TEMPS WITH LOWS IN THE UPPER 20S ARE LIKELY FOR THE INTERIOR AND PARTS OF EASTERN LONG ISLAND WHILE LOWS WILL DROP IN THE 30S MOST ELSEWHERE. A DEEP UPPER TROUGH WITH SEVERAL STRONG SHORTWAVES WILL PASS THROUGH THE REGION SUNDAY NIGHT...AND WILL ONLY CARRY A HIDDEN SLIGHT CHANCE POPS FOR THAT TIME. OTHERWISE...DRY CONDS WITH TEMPS GRADUALLY MODERATING FROM HIGHS IN THE 50S TO HIGHS IN THE 60S BY THE MIDDLE OF THE WEEK. HIGH PRES MOVES OFFSHORE THEN...AND A FRONTAL BOUNDARY LIFTS TOWARDS THE REGION. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... A FAST MOVING COLD FRONT WILL MOVE THROUGH THE TERMINALS THIS MORNING FROM 10Z-13Z. EXPECT MAINLY VFR CONDITIONS WITH A BRIEF SHOWER POSSIBLE AS THE FRONT PASSES. FORECAST CHALLENGE WILL BE THE TIMING OF THE NW WIND GUSTS AS WELL AS MAGNITUDE. DEEP MIXING TODAY SHOULD ALLOW GUSTS TO HANG ON THROUGH FIRST HALF OF AFT. IN ADDITION...THERE COULD BE A BRIEF STRONG GUST UP TO 25 KT AHEAD OF THE FRONT THIS MORNING. .OUTLOOK FOR 06Z SAT THROUGH TUESDAY... .SAT-SUN...VFR. NW WINDS G20-25KT. .MON-TUE...VFR. && .MARINE... WINDS AND SEAS INCREASE EARLY THIS MORNING WITH THE APPROACH OF A COLD FRONT. THE FRONT WILL MOVE ACROSS THE WATERS LATER THIS MORNING. SCA REMAINS IN EFFECT FOR THE OCEAN WATERS. SEAS ON THE EASTERN OCEAN WATERS SHOULD TAKE LONGER TO SUBSIDE WITH A WESTERLY FLOW...SO THE SCA ENDS WEST OF MORICHES INLET AT 18Z FRI...AND CONTINUES TO THE EAST THROUGH THE REST OF THE AFTERNOON. FOR THE REST OF THE WATERS...SUB-SCA CONDITIONS THROUGH THE PERIOD ALTHOUGH FAR EASTERN PORTIONS OF LONG ISLAND SOUND COULD SEE SOME GUSTS TO 25 KT THIS MORNING. WOULD LIKE TO HAVE MORE CONFIDENCE IN A MORE WIDESPREAD EVENT BEFORE INCLUDING THEM IN THE SCA. WINDS DIMINISH THIS EVENING...THEN INCREASE AGAIN LATE TONIGHT AS A TROUGH APPROACHES AND TIGHTENS THE PRESSURE GRADIENT. SMALL CRAFT CONDS ARE LIKELY SATURDAY THROUGH SUNDAY IN A COLD NW FLOW. AS HIGH PRESSURE BUILDS OVER THE WATERS EARLY IN THE NEW WEEK...CONDS WILL DIMINISH BELOW ADVISORY LEVELS. && .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE FORECAST PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353- 355. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ350. && $$ SYNOPSIS...JC/MPS NEAR TERM...JC/JE/PW SHORT TERM...JC/JE LONG TERM...MPS AVIATION...DW MARINE...JC/MPS/PW HYDROLOGY...JC/MPS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1230 AM EDT FRI OCT 16 2015 .SYNOPSIS... A COLD FRONT APPROACHES OVERNIGHT AND PASSES THROUGH FRIDAY MORNING. A LARGE AREA OF HIGH PRESSURE THEN BUILDS OVER THE REGION FOR THE WEEKEND AND MOVES OFFSHORE BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... CLOUDS WILL BE ON THE INCREASE EARLY THIS MORNING FROM WEST TO EAST WITH THE APPROACH OF A COLD FRONT. MOISTURE IS LIMITED...SO THINKING IS THAT THERE WILL BE ONLY A SLIGHT CHANCE OF A SHOWER AFTER 3 OR 4AM FOR FAR NORTHERN AND WESTERN ZONES AND TOWARDS DAYBREAK FOR POINTS EAST. LATEST HRRR CONCURS WITH LOW COVERAGE. MAV/NAM MOS BLEND WAS USED FOR LOW TEMPS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... COLD FRONT MOVES THROUGH DURING THE FIRST HALF OF FRIDAY MORNING WITH ONLY A SLIGHT CHANCE OF A SHOWER. THE SLIGHT EXCEPTION MAY BE FAR EASTERN ZONES WITH SOMEWHAT HIGHER INSTABILITY FOR THESE AREAS WITH A CHANCE OF SHOWERS... WHICH SHOULD BE OVER BY LATE MORNING. CLOUDS DIMINISH BEHIND THE FRONT...AND A MODERATE WESTERLY DOWNSLOPE FLOW SHOULD HELP HIGH TEMPERATURES REACH SLIGHTLY ABOVE NORMAL. WEAK HIGH PRESSURE WILL BE IN PLACE FRIDAY NIGHT WITH A SURFACE COLD FRONT MOVING IN FROM THE NORTHWEST. MOISTURE LOOKS TOO LIMITED FOR A MENTION OF A POSSIBLE SHOWER...SO WILL MAINTAIN A DRY FORECAST. LOCALIZED FROST NOT OUT OF THE QUESTION FOR SOME OF THE NORTHERN SUBURBS...BUT WITH FCST LOWS IN THE MID-UPPER 30S AND THE POTENTIAL OF A MOSTLY CLOUDY SKY...WILL NOT INCLUDE THIS IN THE FORECAST AT THIS TIME. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGH PRES BUILDS IN FROM THE NORTH AND WEST THIS WEEKEND WITH SOME OF THE COLDEST TEMPS OF THE FALL. WIDESPREAD SUB-FREEZING TEMPS WITH LOWS IN THE UPPER 20S ARE LIKELY FOR THE INTERIOR AND PARTS OF EASTERN LONG ISLAND WHILE LOWS WILL DROP IN THE 30S MOST ELSEWHERE. A DEEP UPPER TROUGH WITH SEVERAL STRONG SHORTWAVES WILL PASS THROUGH THE REGION SUNDAY NIGHT...AND WILL ONLY CARRY A HIDDEN SLIGHT CHANCE POPS FOR THAT TIME. OTHERWISE...DRY CONDS WITH TEMPS GRADUALLY MODERATING FROM HIGHS IN THE 50S TO HIGHS IN THE 60S BY THE MIDDLE OF THE WEEK. HIGH PRES MOVES OFFSHORE THEN...AND A FRONTAL BOUNDARY LIFTS TOWARDS THE REGION. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... A COLD FRONT WILL APPROACH TONIGHT...AND MOVE ACROSS FRI MORNING. TIMING OF FROPA WILL BE ABOUT 09Z-10Z KSWF...11Z NYC METRO...12Z KBDR/KISP...AND 13Z KGON. THERE IS A SLIGHT CHANCE FOR SHOWERS AND BRIEF MVFR CONDS WITH FROPA...TOO LOW TO MENTION IN TAF ATTM BUT THAT COULD CHANGE BASED ON RADAR TRENDS OVERNIGHT. HIGH CONFIDENCE IN SUSTAINED WINDS...BUT ONLY MEDIUM FOR GUSTS...WHICH ARE NOT INCLUDED RIGHT AFTER FROPA BUT COULD BRIEFLY REACH 15-20 KT...THEN COULD BRIEFLY GUST OVER 15 KT FROM ABOUT 14Z-16Z. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: COLD FROPA ABOUT 11Z. BRIEF SHOWER WITH MVFR CONDS AND GUSTS 15-20 KT POSSIBLE WITH FROPA. BRIEF GUSTS TO 25 KT POSSIBLE FROM 14Z-16Z. KLGA FCSTER COMMENTS: COLD FROPA ABOUT 11Z. BRIEF SHOWER WITH MVFR CONDS AND GUSTS 15-20 KT POSSIBLE WITH FROPA. BRIEF GUSTS TO 25 KT POSSIBLE FROM 14Z-16Z. KEWR FCSTER COMMENTS: COLD FROPA ABOUT 11Z. BRIEF SHOWER WITH MVFR CONDS AND GUSTS 15-20 KT POSSIBLE WITH FROPA. BRIEF GUSTS TO 25 KT POSSIBLE FROM 14Z-16Z. KTEB FCSTER COMMENTS: COLD FROPA ABOUT 11Z. BRIEF SHOWER WITH MVFR CONDS AND GUSTS 15-20 KT POSSIBLE WITH FROPA. BRIEF GUSTS TO 25 KT POSSIBLE FROM 14Z-16Z. KHPN FCSTER COMMENTS: COLD FROPA ABOUT 10Z-11Z. BRIEF SHOWER WITH MVFR CONDS AND GUSTS 15-20 KT POSSIBLE WITH FROPA. BRIEF GUSTS TO 25 KT POSSIBLE FROM 14Z-16Z. KISP FCSTER COMMENTS: COLD FROPA ABOUT 12Z. BRIEF SHOWER WITH MVFR CONDS AND GUSTS 15-20 KT POSSIBLE WITH FROPA. BRIEF GUSTS TO 25 KT POSSIBLE FROM 15Z-17Z. .OUTLOOK FOR 00Z SAT THROUGH TUE...VFR. NW WINDS G20KT DAYTIME SAT. && .MARINE... WINDS AND SEAS INCREASE EARLY THIS MORNING WITH THE APPROACH OF A COLD FRONT. THE FRONT WILL MOVE ACROSS THE WATERS LATER THIS MORNING. SCA REMAINS IN EFFECT FOR THE OCEAN WATERS. SEAS ON THE EASTERN OCEAN WATERS SHOULD TAKE LONGER TO SUBSIDE WITH A WESTERLY FLOW...SO THE SCA ENDS WEST OF MORICHES INLET AT 18Z FRI...AND CONTINUES TO THE EAST THROUGH THE REST OF THE AFTERNOON. FOR THE REST OF THE WATERS...SUB-SCA CONDITIONS THROUGH THE PERIOD ALTHOUGH FAR EASTERN PORTIONS OF LONG ISLAND SOUND COULD SEE SOME GUSTS TO 25 KT THIS MORNING. WOULD LIKE TO HAVE MORE CONFIDENCE IN A MORE WIDESPREAD EVENT BEFORE INCLUDING THEM IN THE SCA. WINDS DIMINISH THIS EVENING...THEN INCREASE AGAIN LATE TONIGHT AS A TROUGH APPROACHES AND TIGHTENS THE PRESSURE GRADIENT. SMALL CRAFT CONDS ARE LIKELY SATURDAY THROUGH SUNDAY IN A COLD NW FLOW. AS HIGH PRESSURE BUILDS OVER THE WATERS EARLY IN THE NEW WEEK...CONDS WILL DIMINISH BELOW ADVISORY LEVELS. && .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE FORECAST PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ353- 355. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ350. && $$ SYNOPSIS...JC/MPS NEAR TERM...JC/JE/PW SHORT TERM...JC/JE LONG TERM...MPS AVIATION...GOODMAN/JM MARINE...JC/MPS/PW HYDROLOGY...JC/MPS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
408 AM EDT FRI OCT 16 2015 .SYNOPSIS... DRY COLD FRONT CURRENTLY ACROSS THE MID ATLANTIC STATES AND TN VALLEY WILL MOVE THROUGH THE MIDLANDS THIS AFTERNOON INTO THIS EVENING. THIS WILL ALLOW COLDER AND DRIER AIR TO SETTLE OVER THE REGION TONIGHT THROUGH EARLY NEXT WEEK. MOISTURE WILL SLOWLY BEGIN RETURNING TO THE AREA DURING THE MIDDLE OF NEXT WEEK WITH ANOTHER COLD FRONT APPROACHING FROM THE NORTHWEST LATE NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... DRY COLD FRONT CURRENTLY STRETCHED FROM THE MID ATLANTIC STATES THROUGH THE TN VALLEY WILL TRACK SOUTHEASTWARD TODAY AND CROSS THE FORECAST AREA THIS AFTERNOON THROUGH THIS EVENING. DOWNSLOPING ALONG AND AHEAD OF THE FRONT WILL RESULT IN SOME COMPRESSIONAL WARMING ALONG WITH DRYING. EXPECT SKIES TO BECOME PARTLY CLOUDY WITH FRONTAL PASSAGE...HOWEVER WITH THE LIMITED MOISTURE NO RAIN IS EXPECTED. HIGH PRESSURE ALONG WITH COOLER AND DRIER AIR WILL BEGIN BUILDING INTO THE AREA TONIGHT WITH LIGHT WINDS AND CLEAR SKIES ALLOWING FOR EXCELLENT RADIATIONAL COOLING CONDITIONS. TEMPERATURES THIS AFTERNOON WILL BE IN THE UPPER 70S TO LOWER 80S WITH OVERNIGHT LOWS TONIGHT IN THE UPPER 40S TO LOWER 50S. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... HIGH PRESSURE WILL CONTINUE BUILDING ACROSS THE WESTERN GREAT LAKES SATURDAY AND THE THROUGH THE OHIO VALLEY ON SUNDAY. THIS WILL KEEP THE AREA UNDER COLD AIR ADVECTION SATURDAY WITH THE ADVECTION WEAKENING LATE SUNDAY. WITH THE COOLER AND DRIER AIR OVER THE REGION EXPECT MOSTLY CLEAR SKIES AND LIGHT NORTHERLY WINDS. THE CLEAR SKIES AND LIGHT WINDS WILL ALLOW FOR EXCELLENT RADIATIONAL COOLING CONDITIONS SATURDAY AND SUNDAY NIGHTS. HIGH TEMPERATURES SATURDAY WILL BE IN THE UPPER 60S TO LOWER 70S WITH SUNDAYS HIGHS IN THE LOWER TO MIDDLE 60S. OVERNIGHT LOWS WILL BE IN THE UPPER 40S TO LOWER 50S SATURDAY NIGHT AND LOWER 40S SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... MODELS CONTINUE IN GOOD AGREEMENT THROUGH THURSDAY WITH HIGH PRESSURE DOMINATING THE REGION THROUGH WEDNESDAY WITH UNSETTLED WEATHER APPEARING FOR THURSDAY. WITH COOL AND DRY HIGH PRESSURE DOMINATING THE PATTERN THE COOLEST TEMPERATURES OF THE SEASON WILL BE OVER THE REGION THROUGH EARLY NEXT WEEK. MODELS CONTINUE TO CHANGE OVERNIGHT LOWS A COUPLE OF DEGREES MONDAY NIGHT WITH LOWS IN MANY LOCATIONS CURRENTLY EXPECTED IN THE MIDDLE TO UPPER 30S. ALTHOUGH THERE IS SOME POTENTIAL FOR PATCHY FROST MONDAY NIGHT CONFIDENCE REMAINS TOO LOW TO INCLUDE. TEMPERATURES THROUGH THE LONG TERM WILL BE BELOW NORMAL WITH TEMPERATURES GENERALLY 10 DEGREES BELOW NORMAL THROUGH TUESDAY...THEN RETURNING TO NEAR NORMAL. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED THROUGH THE PERIOD...ALTHOUGH SOME PATCHY FOG POSSIBLE NEAR AGS OVERNIGHT. A DRY AIRMASS WILL HOLD OVERNIGHT WITH CLEAR SKIES AND LIGHT WINDS. LAMP AND HRRR SUGGEST SOME FOG POSSIBLE AT AGS TERMINAL OVERNIGHT. MOISTURE QUITE SHALLOW...AND EXPECT BOUNDARY LAYER WINDS TO INCREASE BY 12Z...SO WILL CONTINUE NO RESTRICTIONS. A MOISTURE LIMITED COLD FRONT WILL MOVE THROUGH THE AREA LATE THIS AFTERNOON OR EARLY EVENING. EXPECT MAINLY MID LEVEL CLOUDINESS ASSOCIATED WITH FRONT. WINDS OVERNIGHT LIGHT AND VARIABLE...THEN INCREASE OUT OF THE WEST AROUND 10 KNOTS DURING THE MORNING WITH SOME HIGHER GUSTS BY 16Z. WINDS SHIFTING TO NORTH BEHIND FRONT. EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED DURING THE OUTLOOK PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
136 AM EDT FRI OCT 16 2015 .SYNOPSIS... A DRY COLD FRONT WILL CROSS THE FORECAST AREA FRIDAY AFTERNOON INTO FRIDAY EVENING. THIS WILL ALLOW COLDER AND DRIER AIR TO SETTLE OVER THE REGION FRIDAY NIGHT THROUGH EARLY NEXT WEEK. SOME MOISTURE WILL BEGIN RETURNING TO THE AREA BY THE MIDDLE OF NEXT WEEK WITH ANOTHER COLD FRONT APPROACHING FROM THE NORTHWEST. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... HIGH PRESSURE OVER THE REGION WILL MOVE SOUTH OF THE AREA LATE TONIGHT AS A FAST MOVING AND MOISTURE LIMITED COLD FRONT REACHES THE APPALACHIANS. A DRY AIR MASS AND WEAK PRESSURE GRADIENT WILL HOLD CLEAR SKIES AND LIGHT WINDS ACROSS THE AREA. EXCELLENT RADIATIONAL COOLING CONDITIONS TONIGHT WILL ALLOW OVERNIGHT LOWS TO FALL INTO THE LOWER 50S. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... AN EXPANSIVE UPPER TROUGH WILL CONTINUE TO BUILD SOUTHEASTWARD OVER MUCH OF THE EASTERN HALF OF THE COUNTRY ON FRIDAY. A COLD FRONT EXTENDING FROM THE MID ATLANTIC TO THE TENNESSEE VALLEY ON FRIDAY MORNING WILL SHIFT SOUTHEASTWARD THROUGH THE DAY AND CROSS THE FORECAST AREA BY FRIDAY NIGHT. MOISTURE IS SHALLOW AND LIMITED WITH THE FRONT WITH PWAT VALUES RISING TO JUST OVER AN INCH AND DOWNSLOPING 850MB FLOW OVER THE MOUNTAINS WILL INHIBIT MUCH CHANCE FOR MEASURABLE PRECIPITATION. WILL CONTINUE TO ADVERTISE THE DRY FORECAST WITH THE FRONTAL PASSAGE AND HIGHLIGHT SOME INCREASE IN CLOUD COVER WITHIN THE FRONTAL ZONE. A 1032MB SURFACE RIDGE WILL BUILD SOUTHWARD OUT OF CENTRAL CANADA AND EXPAND ACROSS THE EASTERN HALF OF THE COUNTRY BY SATURDAY NIGHT PROVIDING FAIR WEATHER UNDER MOSTLY CLEAR SKIES AND COOLER AND DRIER CONDITIONS. TEMPERATURES WILL BE WELL ABOVE NORMAL ON FRIDAY DESPITE SOME CLOUD COVER DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT WITH 850MB TEMPS AROUND +14C TO +15C. MAX TEMPERATURES FRIDAY EXPECTED TO RANGE FROM THE UPPER 70S NORTHERN MIDLANDS TO THE LOWER TO MID 80S IN THE SOUTHERN MIDLANDS AND CSRA. WINDS EXPECTED TO STAY UP THROUGH THE NIGHT FRIDAY NIGHT AND WILL PREVENT STRONG RADIATIONAL COOLING AND KEEP THE BOUNDARY LAYER MIXED...AS OVERNIGHT LOWS WILL GENERALLY BE DETERMINED BY THE COLD ADVECTION. OVERNIGHT LOWS EXPECTED TO BE IN THE UPPER 40S TO LOWER 50S. && .LONG TERM /SUNDAY THROUGH THURSDAY/... STRONG AGREEMENT IN THE MEDIUM RANGE MODELS WITH THE OVERALL WEATHER PATTERN THIS PERIOD...THOUGH SOME UNCERTAINTY AND LOWER CONFIDENCE ARISES NEAR THE END OF THE FORECAST PERIOD. UPPER LEVEL TROUGH AXIS SHIFTS OFF THE COAST SUNDAY AND SUNDAY NIGHT AS AN UPPER RIDGE OVER THE MIDDLE PART OF THE COUNTRY FLATTENS AND SHIFTS EASTWARD OVER THE OHIO/MISSISSIPPI VALLEYS. SURFACE HIGH PRESSURE CENTERED OVER THE UPPER MIDWEST BUILDS EASTWARD TO THE MID ATLANTIC AND BECOMES CENTERED OVER THE CAROLINAS AND VIRGINIA BY MONDAY EVENING. NO CHANCES OF RAIN SUNDAY THROUGH EARLY NEXT WEEK DUE TO THE VERY DRY AND COOL AIRMASS IN PLACE. WE WILL EXPERIENCE OUR COLDEST TEMPERATURES OF THE FALL SEASON THIS WEEKEND INTO EARLY NEXT WEEK WITH TEMPERATURES NEARLY 10-15 DEGREES BELOW NORMAL. AFTERNOON HIGHS SUN-TUE IN THE 60S AND MORNING LOWS MON-TUE IN THE UPPER 30S TO LOWER 40S. THOSE OVERNIGHT LOW TEMPERATURES MAY NEED TO BE LOWERED A BIT FURTHER AS THE MOS GUIDANCE TRENDS HAVE BEEN COLDER WITH SUCCESSIVE RUNS. FROST MAY BE POSSIBLE EACH OF THOSE MORNINGS AS WELL BUT CONFIDENCE STILL LOW ENOUGH TO NOT INCLUDE IN THE FORECAST AT THIS POINT. MOISTURE WILL BEGIN TO RETURN INTO THE REGION LATE TUESDAY INTO WEDNESDAY WITH EASTERLY FLOW OFF THE ATLANTIC CIRCULATING AROUND THE SURFACE HIGH...BRINGING INCREASED CLOUDS AND A SLIGHT CHANCE OF RAIN BY THURSDAY. TEMPERATURES WILL GRADUALLY WARM WED-THU AS WELL. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED THROUGH THE PERIOD...ALTHOUGH SOME PATCHY FOG POSSIBLE NEAR AGS OVERNIGHT. A DRY AIRMASS WILL HOLD OVERNIGHT WITH CLEAR SKIES AND LIGHT WINDS. LAMP AND HRRR SUGGEST SOME FOG POSSIBLE AT AGS TERMINAL OVERNIGHT. MOISTURE QUITE SHALLOW...AND EXPECT BOUNDARY LAYER WINDS TO INCREASE BY 12Z...SO WILL CONTINUE NO RESTRICTIONS. A MOISTURE LIMITED COLD FRONT WILL MOVE THROUGH THE AREA LATE THIS AFTERNOON OR EARLY EVENING. EXPECT MAINLY MID LEVEL CLOUDINESS ASSOCIATED WITH FRONT. WINDS OVERNIGHT LIGHT AND VARIABLE...THEN INCREASE OUT OF THE WEST AROUND 10 KNOTS DURNG THE MORNING WITH SOME HIGHER GUSTS BY 16Z. WINDS SHIFTING TO NORTH BEHIND FRONT. EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED DURING THE OUTLOOK PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 23
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
550 PM EDT FRI OCT 16 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 306 PM EDT FRI OCT 16 2015 STRONG HIGH PRESSURE WILL BRING DRY WEATHER TO THE OHIO VALLEY THROUGH THE MIDDLE OF NEXT WEEK. THE COLDEST TEMPERATURES OF THE SEASON ARE EXPECTED OVER THE WEEKEND WITH A HARD FREEZE LIKELY FOR MANY AREAS. WARMER WEATHER WILL RETURN STARTING MONDAY AND CONTINUE THROUGH THE WEEK...WITH THE PASSAGE OF A WEAK FRONT BRINGING THE NEXT CHANCE FOR A FEW SHOWERS WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /TONIGHT/... ISSUED AT 306 PM EDT FRI OCT 16 2015 COOL BRISK AFTERNOON ONGOING AS STRONG HIGH PRESSURE CONTINUES TO ADVECT DRY AIR INTO THE REGION. CU HAS DEVELOPED DOWNWIND OF LAKE MICHIGAN ACROSS THE NORTHERN PART OF INDIANA...WITH THE FRINGES SNEAKING INTO FAR NORTHEAST COUNTIES. TEMPS HAVE WARMED NICELY FROM THE CHILLY START...RANGING FROM THE UPPER 50S TO LOWER 60S AS OF 18Z. THE PRIMARY CHALLENGE FOR THE NEAR TERM IS THE POTENTIAL FOR NEAR- FREEZING OR SUBFREEZING TEMPS LATE TONIGHT...AND ANY IMPACT FROM LAKE MICHIGAN INDUCED CU/STRATOCU. COLD DRY AIR WILL CONTINUE TO OVERSPREAD THE REGION TONIGHT WITH THE STRONG HIGH PRESSURE SETTLING OVER THE MID MISSISSIPPI VALLEY. BULK OF THE FORECAST AREA WILL REMAIN MOSTLY CLEAR WITH LIGHT WINDS TO THE EAST OF THE HIGH CENTER LIKELY TO NOT DETER WIDESPREAD FROST ACCRUAL AFTER MIDNIGHT. COMBINATION OF A WAVE ALOFT REINFORCING THE UPPER TROUGH OVER THE GREAT LAKES OVERNIGHT AND FAVORABLE LOW LEVEL FLOW OFF THE LAKES WILL KEEP SOME FORM OF LOWER CLOUDS DRIFTING THROUGH NORTHERN INDIANA AND POSSIBLY WORKING INTO THE NORTHEAST QUARTER OF THE FORECAST AREA OVERNIGHT. NAM IS MOST AGGRESSIVE IN PUSHING DEEPER MOISTURE IN THE 925-850MB LAYER INTO AREAS NORTHEAST OF THE INDY METRO...AND THE RAP IS STARTING TO HINT AT THIS TOWARD DAWN AS WELL. EVEN WITH BROKEN CLOUDS DRIFTING INTO NORTHEAST COUNTIES LATE... THOSE AREAS ARE LIKELY TO EXPERIENCE ENOUGH TIME WITH MAINLY CLEAR SKIES THIS EVENING THAT TEMPS SHOULD STILL MAKE A RUN TOWARDS THE FREEZING MARK...WITH POTENTIAL TO GO LOWER IF LESS CLOUDS DEVELOP THAN CURRENTLY THINKING. FOR THAT REASON...HAVE CHOSEN TO UPGRADE THE ENTIRE FORECAST AREA TO A FREEZE WARNING OVERNIGHT. NOT EVERYONE IS GOING TO GET TO 32 OR LOWER...BUT STILL FEEL A WIDESPREAD FROST IS LIKELY FOR MUCH OF THE AREA. TEMPS...LEANED TOWARDS LOW END OF MOS AND EVEN UNDERCUT IT BY A FEW DEGREES IN SOME AREAS. WITH THE LACK OF SIGNIFICANT PRECIP OVER THE LAST SEVERAL WEEKS...TEMP RESPONSE HAS OUTPACED MOS GUIDANCE ON BOTH HIGHS AND LOWS THE LAST FEW DAYS. EVEN WITH POTENTIAL FOR SOME CLOUDS LATE...THINK UPPER 20S AND LOWER 30S WILL BE COMMON FOR LOWS OVERNIGHT. && .SHORT TERM /SATURDAY THROUGH MONDAY/... ISSUED AT 306 PM EDT FRI OCT 16 2015 FORECAST CHALLENGES ARE ON TEMPS THROUGH THE PERIOD...INCLUDING THE POTENTIAL FOR THE GROWING SEASON TO COME TO AN OFFICIAL END EARLY SUNDAY MORNING. AFOREMENTIONED STRONG HIGH PRESSURE WILL DRIFT ACROSS THE OHIO VALLEY THROUGH THE SHORT TERM PERIOD...AND BE THE PRIMARY INFLUENCE ON WEATHER FOR THE NEXT FEW DAYS. SCATTERED CU/STRATOCU MAY BE A BIT MORE PREVALENT ON SATURDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF THE FORECAST AREA...AS AN UPPER LEVEL WAVE PASSES THROUGH THE GREAT LAKES AND SOUNDINGS/RH PROGS SUPPORT INCREASED MOISTURE IN THE 925- 850MB LAYER. ANY CU WILL DISSIPATE AROUND OR SHORTLY AFTER SUNSET SATURDAY EVENING AS DRIER AIR AND DEEP SUBSIDENCE OVERSPREADS THE REGION. WITH THE HIGH CENTERED OVER THE AREA AND THE 850MB COLD POOL NEARBY SATURDAY NIGHT...BEST CHANCE AT A WIDESPREAD HARD FREEZE OVER THE AREA WILL EXIST. HAVE MAINTAINED THE FREEZE WATCH FOR SATURDAY NIGHT/EARLY SUNDAY FOR NOW...BUT HAVE NO DOUBT THAT THIS WILL BE UPGRADED TO A WARNING EITHER TONIGHT OR DURING THE DAY SATURDAY. WARM ADVECTION WILL COMMENCE BEGINNING SUNDAY AND CONTINUE THROUGH THE REST OF THE SHORT TERM WITH UPPER RIDGING EXPANDING INTO THE MISSISSIPPI AND OHIO VALLEYS ON MONDAY. TIGHTENING SURFACE PRESSURE GRADIENT WILL DEVELOP AND PRODUCE BREEZY SOUTHWEST FLOW MONDAY BETWEEN THE HIGH JUST TO OUR EAST AND A COLD FRONT MOVING THROUGH THE NORTHERN PLAINS. TEMPS...GOING ALONG WITH TEMP BEHAVIOR LAST FEW DAYS...LEANED TOWARDS FAR ENDS OF THE GUIDANCE ON BOTH HIGHS AND LOWS THROUGH MUCH OF THE PERIOD. UNDERCUT MOS MOST EVERYWHERE SATURDAY NIGHT WITH MANY AREAS BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE UNDER IDEAL RADIATIONAL COOLING SETUP. HIGHS WILL RECOVER BACK INTO THE MID AND UPPER 60S BY MONDAY AND SOME AREAS IN THE WABASH VALLEY COULD MAKE A RUN AT 70. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 218 PM EDT FRI OCT 16 2015 MODELS ARE IN GOOD AGREEMENT ON UPPER RIDGING IN PLACE OVER THE AREA TO BEGIN THE LONG TERM. SOLUTION SPREAD INCREASES BY MID WEEK WITH DIFFERENCES IN TIMING/PLACEMENT OF A SHORTWAVE MOVING ACROSS THE NORTHERN PLAINS AND THROUGH THE GREAT LAKES. ACCEPTED INITIALIZATION WITH ONLY QUALITY CONTROL ADJUSTMENTS RESULTING IN SLIGHT CHANCE POPS IN THE NORTHERN AND CENTRAL COUNTIES TAPERING TO DRY SOUTH. TEMPERATURES WILL RUN SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS IN THE MID 40S TO LOWER 50S. && .AVIATION /DISCUSSION FOR 170000Z TAF ISSUANCE/... ISSUED AT 550 PM EDT FRI OCT 16 2015 HIGH CONFIDENCE THAT VERY DRY BOUNDARY LAYER UNDER HIGH PRESSURE WILL RESULT IN VFR CONDITIONS THROUGH THE TAF PERIOD. GUSTY NORTHWEST WINDS WILL DROP TO BELOW 10 KNOTS BY ISSUANCE TIME AND BECOME LIGHT TO CALM LATE EVENING. THE WINDS WILL PICK UP TO AROUND 10 KNOTS TOMORROW AFTER 15Z...BUT MORE RELAXED PRESSURE GRADIENT WILL DISCOURAGE GUSTS. && .IND WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR INZ021-028>031-035>049-051>057-060>065-067>072. FREEZE WARNING FROM 3 AM TO 10 AM EDT SATURDAY FOR INZ021- 028>031-035>049-051>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
415 PM EDT FRI OCT 16 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 306 PM EDT FRI OCT 16 2015 STRONG HIGH PRESSURE WILL BRING DRY WEATHER TO THE OHIO VALLEY THROUGH THE MIDDLE OF NEXT WEEK. THE COLDEST TEMPERATURES OF THE SEASON ARE EXPECTED OVER THE WEEKEND WITH A HARD FREEZE LIKELY FOR MANY AREAS. WARMER WEATHER WILL RETURN STARTING MONDAY AND CONTINUE THROUGH THE WEEK...WITH THE PASSAGE OF A WEAK FRONT BRINGING THE NEXT CHANCE FOR A FEW SHOWERS WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /TONIGHT/... ISSUED AT 306 PM EDT FRI OCT 16 2015 COOL BRISK AFTERNOON ONGOING AS STRONG HIGH PRESSURE CONTINUES TO ADVECT DRY AIR INTO THE REGION. CU HAS DEVELOPED DOWNWIND OF LAKE MICHIGAN ACROSS THE NORTHERN PART OF INDIANA...WITH THE FRINGES SNEAKING INTO FAR NORTHEAST COUNTIES. TEMPS HAVE WARMED NICELY FROM THE CHILLY START...RANGING FROM THE UPPER 50S TO LOWER 60S AS OF 18Z. THE PRIMARY CHALLENGE FOR THE NEAR TERM IS THE POTENTIAL FOR NEAR- FREEZING OR SUBFREEZING TEMPS LATE TONIGHT...AND ANY IMPACT FROM LAKE MICHIGAN INDUCED CU/STRATOCU. COLD DRY AIR WILL CONTINUE TO OVERSPREAD THE REGION TONIGHT WITH THE STRONG HIGH PRESSURE SETTLING OVER THE MID MISSISSIPPI VALLEY. BULK OF THE FORECAST AREA WILL REMAIN MOSTLY CLEAR WITH LIGHT WINDS TO THE EAST OF THE HIGH CENTER LIKELY TO NOT DETER WIDESPREAD FROST ACCRUAL AFTER MIDNIGHT. COMBINATION OF A WAVE ALOFT REINFORCING THE UPPER TROUGH OVER THE GREAT LAKES OVERNIGHT AND FAVORABLE LOW LEVEL FLOW OFF THE LAKES WILL KEEP SOME FORM OF LOWER CLOUDS DRIFTING THROUGH NORTHERN INDIANA AND POSSIBLY WORKING INTO THE NORTHEAST QUARTER OF THE FORECAST AREA OVERNIGHT. NAM IS MOST AGGRESSIVE IN PUSHING DEEPER MOISTURE IN THE 925-850MB LAYER INTO AREAS NORTHEAST OF THE INDY METRO...AND THE RAP IS STARTING TO HINT AT THIS TOWARD DAWN AS WELL. EVEN WITH BROKEN CLOUDS DRIFTING INTO NORTHEAST COUNTIES LATE... THOSE AREAS ARE LIKELY TO EXPERIENCE ENOUGH TIME WITH MAINLY CLEAR SKIES THIS EVENING THAT TEMPS SHOULD STILL MAKE A RUN TOWARDS THE FREEZING MARK...WITH POTENTIAL TO GO LOWER IF LESS CLOUDS DEVELOP THAN CURRENTLY THINKING. FOR THAT REASON...HAVE CHOSEN TO UPGRADE THE ENTIRE FORECAST AREA TO A FREEZE WARNING OVERNIGHT. NOT EVERYONE IS GOING TO GET TO 32 OR LOWER...BUT STILL FEEL A WIDESPREAD FROST IS LIKELY FOR MUCH OF THE AREA. TEMPS...LEANED TOWARDS LOW END OF MOS AND EVEN UNDERCUT IT BY A FEW DEGREES IN SOME AREAS. WITH THE LACK OF SIGNIFICANT PRECIP OVER THE LAST SEVERAL WEEKS...TEMP RESPONSE HAS OUTPACED MOS GUIDANCE ON BOTH HIGHS AND LOWS THE LAST FEW DAYS. EVEN WITH POTENTIAL FOR SOME CLOUDS LATE...THINK UPPER 20S AND LOWER 30S WILL BE COMMON FOR LOWS OVERNIGHT. && .SHORT TERM /SATURDAY THROUGH MONDAY/... ISSUED AT 306 PM EDT FRI OCT 16 2015 FORECAST CHALLENGES ARE ON TEMPS THROUGH THE PERIOD...INCLUDING THE POTENTIAL FOR THE GROWING SEASON TO COME TO AN OFFICIAL END EARLY SUNDAY MORNING. AFOREMENTIONED STRONG HIGH PRESSURE WILL DRIFT ACROSS THE OHIO VALLEY THROUGH THE SHORT TERM PERIOD...AND BE THE PRIMARY INFLUENCE ON WEATHER FOR THE NEXT FEW DAYS. SCATTERED CU/STRATOCU MAY BE A BIT MORE PREVALENT ON SATURDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF THE FORECAST AREA...AS AN UPPER LEVEL WAVE PASSES THROUGH THE GREAT LAKES AND SOUNDINGS/RH PROGS SUPPORT INCREASED MOISTURE IN THE 925- 850MB LAYER. ANY CU WILL DISSIPATE AROUND OR SHORTLY AFTER SUNSET SATURDAY EVENING AS DRIER AIR AND DEEP SUBSIDENCE OVERSPREADS THE REGION. WITH THE HIGH CENTERED OVER THE AREA AND THE 850MB COLD POOL NEARBY SATURDAY NIGHT...BEST CHANCE AT A WIDESPREAD HARD FREEZE OVER THE AREA WILL EXIST. HAVE MAINTAINED THE FREEZE WATCH FOR SATURDAY NIGHT/EARLY SUNDAY FOR NOW...BUT HAVE NO DOUBT THAT THIS WILL BE UPGRADED TO A WARNING EITHER TONIGHT OR DURING THE DAY SATURDAY. WARM ADVECTION WILL COMMENCE BEGINNING SUNDAY AND CONTINUE THROUGH THE REST OF THE SHORT TERM WITH UPPER RIDGING EXPANDING INTO THE MISSISSIPPI AND OHIO VALLEYS ON MONDAY. TIGHTENING SURFACE PRESSURE GRADIENT WILL DEVELOP AND PRODUCE BREEZY SOUTHWEST FLOW MONDAY BETWEEN THE HIGH JUST TO OUR EAST AND A COLD FRONT MOVING THROUGH THE NORTHERN PLAINS. TEMPS...GOING ALONG WITH TEMP BEHAVIOR LAST FEW DAYS...LEANED TOWARDS FAR ENDS OF THE GUIDANCE ON BOTH HIGHS AND LOWS THROUGH MUCH OF THE PERIOD. UNDERCUT MOS MOST EVERYWHERE SATURDAY NIGHT WITH MANY AREAS BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE UNDER IDEAL RADIATIONAL COOLING SETUP. HIGHS WILL RECOVER BACK INTO THE MID AND UPPER 60S BY MONDAY AND SOME AREAS IN THE WABASH VALLEY COULD MAKE A RUN AT 70. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 218 PM EDT FRI OCT 16 2015 MODELS ARE IN GOOD AGREEMENT ON UPPER RIDGING IN PLACE OVER THE AREA TO BEGIN THE LONG TERM. SOLUTION SPREAD INCREASES BY MID WEEK WITH DIFFERENCES IN TIMING/PLACEMENT OF A SHORTWAVE MOVING ACROSS THE NORTHERN PLAINS AND THROUGH THE GREAT LAKES. ACCEPTED INITIALIZATION WITH ONLY QUALITY CONTROL ADJUSTMENTS RESULTING IN SLIGHT CHANCE POPS IN THE NORTHERN AND CENTRAL COUNTIES TAPERING TO DRY SOUTH. TEMPERATURES WILL RUN SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS IN THE MID 40S TO LOWER 50S. && .AVIATION /DISCUSSION FOR 162100Z IND TAF UPDATE/... ISSUED AT 415 PM EDT FRI OCT 16 2015 NO CHANGES NEEDED TO THE TAF. PREVIOUS DISCUSSION FOLLOWS... ISSUED AT 1255 PM EDT FRI OCT 16 2015 VFR THROUGH THE PERIOD. COULD SEE FEW TO SCATTERED CU SNEAK INTO KLAF AND KIND THIS AFTERNOON AROUND 3-4 KFT BUT NOT EXPECTING A CEILING. NORTHWESTERLY WINDS AROUND 8-12 KTS WITH GUSTS OF 18-22 KTS SHOULD DEVELOP SHORTLY IF NOT ALREADY OCCURRING AT THE SITES AND THEN SHOULD PERSIST THROUGH AROUND 23Z. WINDS SHOULD REMAIN AROUND 3-5 KTS DURING THE OVERNIGHT OUT OF THE NORTHWEST. SATURDAY EXPECT TO SEE WINDS PICK BACK UP BY MID MORNING TO AROUND 9-12 KTS OUT OF THE NORTHWEST. && .IND WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR INZ021-028>031-035>049-051>057-060>065-067>072. FREEZE WARNING FROM 3 AM TO 10 AM EDT SATURDAY FOR INZ021- 028>031-035>049-051>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...CP/MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
306 PM EDT FRI OCT 16 2015 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 306 PM EDT FRI OCT 16 2015 STRONG HIGH PRESSURE WILL BRING DRY WEATHER TO THE OHIO VALLEY THROUGH THE MIDDLE OF NEXT WEEK. THE COLDEST TEMPERATURES OF THE SEASON ARE EXPECTED OVER THE WEEKEND WITH A HARD FREEZE LIKELY FOR MANY AREAS. WARMER WEATHER WILL RETURN STARTING MONDAY AND CONTINUE THROUGH THE WEEK...WITH THE PASSAGE OF A WEAK FRONT BRINGING THE NEXT CHANCE FOR A FEW SHOWERS WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /TONIGHT/... ISSUED AT 306 PM EDT FRI OCT 16 2015 COOL BRISK AFTERNOON ONGOING AS STRONG HIGH PRESSURE CONTINUES TO ADVECT DRY AIR INTO THE REGION. CU HAS DEVELOPED DOWNWIND OF LAKE MICHIGAN ACROSS THE NORTHERN PART OF INDIANA...WITH THE FRINGES SNEAKING INTO FAR NORTHEAST COUNTIES. TEMPS HAVE WARMED NICELY FROM THE CHILLY START...RANGING FROM THE UPPER 50S TO LOWER 60S AS OF 18Z. THE PRIMARY CHALLENGE FOR THE NEAR TERM IS THE POTENTIAL FOR NEAR- FREEZING OR SUBFREEZING TEMPS LATE TONIGHT...AND ANY IMPACT FROM LAKE MICHIGAN INDUCED CU/STRATOCU. COLD DRY AIR WILL CONTINUE TO OVERSPREAD THE REGION TONIGHT WITH THE STRONG HIGH PRESSURE SETTLING OVER THE MID MISSISSIPPI VALLEY. BULK OF THE FORECAST AREA WILL REMAIN MOSTLY CLEAR WITH LIGHT WINDS TO THE EAST OF THE HIGH CENTER LIKELY TO NOT DETER WIDESPREAD FROST ACCRUAL AFTER MIDNIGHT. COMBINATION OF A WAVE ALOFT REINFORCING THE UPPER TROUGH OVER THE GREAT LAKES OVERNIGHT AND FAVORABLE LOW LEVEL FLOW OFF THE LAKES WILL KEEP SOME FORM OF LOWER CLOUDS DRIFTING THROUGH NORTHERN INDIANA AND POSSIBLY WORKING INTO THE NORTHEAST QUARTER OF THE FORECAST AREA OVERNIGHT. NAM IS MOST AGGRESSIVE IN PUSHING DEEPER MOISTURE IN THE 925-850MB LAYER INTO AREAS NORTHEAST OF THE INDY METRO...AND THE RAP IS STARTING TO HINT AT THIS TOWARD DAWN AS WELL. EVEN WITH BROKEN CLOUDS DRIFTING INTO NORTHEAST COUNTIES LATE... THOSE AREAS ARE LIKELY TO EXPERIENCE ENOUGH TIME WITH MAINLY CLEAR SKIES THIS EVENING THAT TEMPS SHOULD STILL MAKE A RUN TOWARDS THE FREEZING MARK...WITH POTENTIAL TO GO LOWER IF LESS CLOUDS DEVELOP THAN CURRENTLY THINKING. FOR THAT REASON...HAVE CHOSEN TO UPGRADE THE ENTIRE FORECAST AREA TO A FREEZE WARNING OVERNIGHT. NOT EVERYONE IS GOING TO GET TO 32 OR LOWER...BUT STILL FEEL A WIDESPREAD FROST IS LIKELY FOR MUCH OF THE AREA. TEMPS...LEANED TOWARDS LOW END OF MOS AND EVEN UNDERCUT IT BY A FEW DEGREES IN SOME AREAS. WITH THE LACK OF SIGNIFICANT PRECIP OVER THE LAST SEVERAL WEEKS...TEMP RESPONSE HAS OUTPACED MOS GUIDANCE ON BOTH HIGHS AND LOWS THE LAST FEW DAYS. EVEN WITH POTENTIAL FOR SOME CLOUDS LATE...THINK UPPER 20S AND LOWER 30S WILL BE COMMON FOR LOWS OVERNIGHT. && .SHORT TERM /SATURDAY THROUGH MONDAY/... ISSUED AT 306 PM EDT FRI OCT 16 2015 FORECAST CHALLENGES ARE ON TEMPS THROUGH THE PERIOD...INCLUDING THE POTENTIAL FOR THE GROWING SEASON TO COME TO AN OFFICIAL END EARLY SUNDAY MORNING. AFOREMENTIONED STRONG HIGH PRESSURE WILL DRIFT ACROSS THE OHIO VALLEY THROUGH THE SHORT TERM PERIOD...AND BE THE PRIMARY INFLUENCE ON WEATHER FOR THE NEXT FEW DAYS. SCATTERED CU/STRATOCU MAY BE A BIT MORE PREVALENT ON SATURDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF THE FORECAST AREA...AS AN UPPER LEVEL WAVE PASSES THROUGH THE GREAT LAKES AND SOUNDINGS/RH PROGS SUPPORT INCREASED MOISTURE IN THE 925- 850MB LAYER. ANY CU WILL DISSIPATE AROUND OR SHORTLY AFTER SUNSET SATURDAY EVENING AS DRIER AIR AND DEEP SUBSIDENCE OVERSPREADS THE REGION. WITH THE HIGH CENTERED OVER THE AREA AND THE 850MB COLD POOL NEARBY SATURDAY NIGHT...BEST CHANCE AT A WIDESPREAD HARD FREEZE OVER THE AREA WILL EXIST. HAVE MAINTAINED THE FREEZE WATCH FOR SATURDAY NIGHT/EARLY SUNDAY FOR NOW...BUT HAVE NO DOUBT THAT THIS WILL BE UPGRADED TO A WARNING EITHER TONIGHT OR DURING THE DAY SATURDAY. WARM ADVECTION WILL COMMENCE BEGINNING SUNDAY AND CONTINUE THROUGH THE REST OF THE SHORT TERM WITH UPPER RIDGING EXPANDING INTO THE MISSISSIPPI AND OHIO VALLEYS ON MONDAY. TIGHTENING SURFACE PRESSURE GRADIENT WILL DEVELOP AND PRODUCE BREEZY SOUTHWEST FLOW MONDAY BETWEEN THE HIGH JUST TO OUR EAST AND A COLD FRONT MOVING THROUGH THE NORTHERN PLAINS. TEMPS...GOING ALONG WITH TEMP BEHAVIOR LAST FEW DAYS...LEANED TOWARDS FAR ENDS OF THE GUIDANCE ON BOTH HIGHS AND LOWS THROUGH MUCH OF THE PERIOD. UNDERCUT MOS MOST EVERYWHERE SATURDAY NIGHT WITH MANY AREAS BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE UNDER IDEAL RADIATIONAL COOLING SETUP. HIGHS WILL RECOVER BACK INTO THE MID AND UPPER 60S BY MONDAY AND SOME AREAS IN THE WABASH VALLEY COULD MAKE A RUN AT 70. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 218 PM EDT FRI OCT 16 2015 MODELS ARE IN GOOD AGREEMENT ON UPPER RIDGING IN PLACE OVER THE AREA TO BEGIN THE LONG TERM. SOLUTION SPREAD INCREASES BY MID WEEK WITH DIFFERENCES IN TIMING/PLACEMENT OF A SHORTWAVE MOVING ACROSS THE NORTHERN PLAINS AND THROUGH THE GREAT LAKES. ACCEPTED INITIALIZATION WITH ONLY QUALITY CONTROL ADJUSTMENTS RESULTING IN SLIGHT CHANCE POPS IN THE NORTHERN AND CENTRAL COUNTIES TAPERING TO DRY SOUTH. TEMPERATURES WILL RUN SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS IN THE MID 40S TO LOWER 50S. && .AVIATION /DISCUSSION FOR 161800Z TAF ISSUANCE/... ISSUED AT 1255 PM EDT FRI OCT 16 2015 VFR THROUGH THE PERIOD. COULD SEE FEW TO SCATTERED CU SNEAK INTO KLAF AND KIND THIS AFTERNOON AROUND 3-4 KFT BUT NOT EXPECTING A CEILING. NORTHWESTERLY WINDS AROUND 8-12 KTS WITH GUSTS OF 18-22 KTS SHOULD DEVELOP SHORTLY IF NOT ALREADY OCCURRING AT THE SITES AND THEN SHOULD PERSIST THROUGH AROUND 23Z. WINDS SHOULD REMAIN AROUND 3-5 KTS DURING THE OVERNIGHT OUT OF THE NORTHWEST. SATURDAY EXPECT TO SEE WINDS PICK BACK UP BY MID MORNING TO AROUND 9-12 KTS OUT OF THE NORTHWEST. && .IND WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR INZ021-028>031-035>049-051>057-060>065-067>072. FREEZE WARNING FROM 3 AM TO 10 AM EDT SATURDAY FOR INZ021- 028>031-035>049-051>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....CP AVIATION...CP
AREA FORECAST DISCUSSION
NWS GOODLAND KS
509 PM MDT SAT OCT 17 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 137 PM MDT SAT OCT 17 2015 EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS INDICATED LONGWAVE TROUGH ACROSS THE EASTERN US WITH RIDGING ACROSS THE PLAINS AND INTO THE NORTHERN ROCKIES. A CLOSED UPPER LOW IS OFF THE NORTHERN CALIFORNIA COAST. SURFACE LOW PRESSURE HAS DEVELOPED OVER NORTH CENTRAL COLORADO WITH TIGHT SOUTHERLY GRADIENT ACROSS THE PLAINS RESPONSIBLE FOR BREEZY-WINDY CONDITIONS ACROSS OUR CWA. TONIGHT-SUNDAY...CLOSED LOW OFF PACIFIC NW WILL SHIFT TOWARDS THE GREAT BASIN AND WITH A WEAKER SHORTWAVE TROUGH ROTATING AROUND NORTHERN EDGE OF UPPER RIDGE INTO THE NORTHERN PLAINS. WEAK FORCING WILL BE RESPONSIBLE FOR PERIODS OF HIGH CLOUD COVER OTHERWISE A DEEP DRY LAYER IN PLACE WILL PREVENT PRECIP DEVELOPMENT IN OUR CWA THROUGH SUNDAY AFTERNOON. LEE TROUGH WILL SHIFT EAST OVER OUR CWA WITH INCREASING WAA AND UNSEASONABLY WARM TEMPERATURES RETURNING. BASED ON MIXING HEIGHTS/TEMPS ALOFT WE SHOULD SEE HIGHS AROUND 80F WHICH IS ABOUT 15F ABOVE NORMAL SUNDAY. LOWS TONIGHT WILL BE TRICKY AS A RESULT OF A MODERATELY STRONG LLJ INCREASING BL MIXING...HOWEVER LOCATIONS IN THE NORTH AND ALONG VALLEYS SHOULD STILL BE ABLE TO DECOUPLE AND COOL TO AROUND 40F. WE MAY ALSO SEE A PERIOD OF LIGHT FOG DEVELOP ALONG VALLEYS/LOW AREAS IN OUR NW ALONG SURFACE TROUGH AS LOW LEVEL MOISTURE INCREASES. CONFIDENCE WAS TOO LOW AT THIS TIME TO INCLUDE MENTION DUE TO EXPECTED MIXING...BUT WE WILL NEED TO MONITOR. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 116 PM MDT SAT OCT 17 2015 THE CENTRAL HIGH PLAINS WILL BE UNDER SOUTHWESTERLY TO SOUTHERLY FLOW ALOFT THE ENTIRE LONG PERIOD AHEAD OF A SLOW MOVING TROUGH SET TO MOVE OUT OF THE DESERT SOUTHWEST LATE IN THE WEEK. THE LOWER LEVELS WILL GRADUALLY MOISTEN WITH THE FIRST CHANCE OF PRECIPITATION OCCURRING TUESDAY NIGHT MAINLY SOUTH OF THE INTERSTATE THEN SPREADING OVER THE REST OF THE AREA ON WEDNESDAY. RAIN CHANCES WILL CONTINUE THROUGH THE END OF THE PERIOD WITH A SERIES OF DISTURBANCES EJECTING OUT OF THE SOUTHWEST. MODELS SUGGEST AREAS OF HEAVY RAIN POSSIBLE THURSDAY THROUGH THURSDAY NIGHT AS THE MAIN LIFT MOVES OVER THE AREA. THE CLOUDS AND PRECIPITATION WILL ALSO RESULT IN COOLER TEMPERATURES FOR THE END OF THE PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 507 PM MDT SAT OCT 17 2015 VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS AS HIGH PRESSURE RESIDES OVER THE PLAINS. LIGHT WINDS SHIFT TO THE SOUTH AND BECOME GUSTY SUNDAY AFTERNOON. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...FS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
831 PM EDT SAT OCT 17 2015 .UPDATE... ISSUED AT 830 PM EDT SAT OCT 17 2015 HIGH PRESSURE CENTERED OVER THE MID MS VALLEY CONTINUES TO GRADUALLY SHIFT EAST INTO THE OH VALLEY REGION AND HAS USHERED IN A RELATIVELY COLD AND DRY AIRMASS FOR MID OCTOBER. A DISTURBANCE PASSING BY TO THE NORTHEAST HAS LED TO SOME STRATOCU AROUND 6KFT ACROSS THE EASTERN HALF OF THE AREA. HOWEVER...THE BACK EDGE OF THESE APPEAR TO BE OVER INDIANA...AND VALLEY LOCATIONS HAVE ALREADY DECOUPLED. THIS AND DEWPOINTS IN THE UPPER 20S TO AROUND 30 WILL SET THE STAGE FOR A HARD FREEZE IN MANY VALLEY LOCATIONS. OTHER THAN SOME SLIGHT ADJUSTMENTS TO HOURLY GRIDS...NO CHANGES WERE NEEDED ATTM. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 200 PM EDT SAT OCT 17 2015 17Z SFC ANALYSIS SHOWS HIGH PRESSURE SETTLING INTO THE MID MISSISSIPPI VALLEY WITH ITS INFLUENCE STRETCHING WELL EAST INTO THE OHIO VALLEY. THIS HAS LED TO A DRY AIR MASS OVER EASTERN KENTUCKY ALONG WITH AMPLE MORNING SUNSHINE. THESE FACTORS CONTRIBUTED TO TEMPERATURES REBOUNDING INTO THE MIDDLE AND UPPER 50S BY EARLY THIS AFTERNOON. DEVELOPING CU TO THE NORTH WILL LIMIT ADDITIONAL HEATING THERE...BUT THE SOUTH COULD RISE ANOTHER COUPLE OF DEGREES FOR HIGHS. DEWPOINTS...MEANWHILE...ARE IN THE UPPER 20S AND LOWER 30S YIELDING RH VALUES DOWN NEAR 30 PERCENT IN THE SOUTH AND CLOSER TO 40 PERCENT NORTH. WINDS HAVE BEEN GENERALLY OUT OF THE NORTH AT 5 TO 10 MPH. THE MODELS REMAIN IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST AS THEY ALL GRADUALLY MOVE A BROAD AND RELATIVELY DEEP TROUGH THE NORTHEASTERN PARTS OF NORTH AMERICA. IN THE WAKE OF THIS TROUGH DEPARTING THE OHIO VALLEY... HEIGHTS WILL RISE OVER KENTUCKY SUNDAY INTO MONDAY MORNING. GIVEN THIS AGREEMENT HAVE FOLLOWED THE WEATHER DETAILS...FEW THAT THERE ARE...FROM THE HRRR AND NAM12. DID AGAIN LEAN HEAVILY ON THE GFS BASED COOP MOS TO HELP HIT OUR VALLEY COLD SPOTS TONIGHT AND SUNDAY NIGHT. SENSIBLE WEATHER WILL FEATURE A COLD NIGHT UNDER MOSTLY CLEAR SKIES...ONCE THE NORTHERN CU FADES AROUND SUNSET. GOOD RADIATIONAL COOLING UNDER THE INVERSION WILL RESULT IN VALLEY TEMPS FALLING INTO THE MIDDLE 20S WHILE RIDGES SETTLE INTO THE LOWER 30S. THESE LOW TEMPS WILL WARRANT A FREEZE WARNING WITH THE POTENTIAL TO END THE GROWING SEASON THROUGHOUT THE CWA...IN ADDITION TO ANTICIPATED WIDESPREAD FROST. PATCHY DENSE FOG IN THE RIVER VALLEYS IS ALSO LIKELY TO FORM GIVEN WHAT WE SAW THIS MORNING. AFTER COORDINATION WITH THE UK AG WX CENTER YESTERDAY WILL CONTINUE FROST/FREEZE HEADLINES INTO MONDAY MORNING REGARDLESS OF HOW COLD IT GETS TONIGHT. FOLLOWING ANOTHER COOL DAY ON SUNDAY...CONDITIONS SIMILAR TO TONIGHT WILL SET THE STAGE FOR ANOTHER ROUND OF FREEZING TEMPERATURES IN THE VALLEYS...ESPECIALLY THE EASTERN ONES. SO... THIS NECESSITATES ANOTHER FREEZE WARNING FOR LATE SUNDAY NIGHT INTO MONDAY MORNING. AGAIN FROST WILL BE PREVALENT THROUGHOUT THE AREA ALONG WITH PATCHY FOG IN THE RIVER VALLEYS. AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR THE T AND TD GRIDS INTO SUNDAY MORNING WITH THE SUPERBLEND USED THEREAFTER. DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND SUNDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY DIFFERENCES. AS FOR POPS...AGAIN WENT ZERO THROUGH THE SHORT TERM PERIOD...IN LINE WITH ALL GUIDANCE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 200 PM EDT SAT OCT 17 2015 HIGH PRESSURE WILL DOMINATE THROUGH THE EXTENDED PORTION OF THE FORECAST...PROVIDING DRY WEATHER AND WARMING TEMPERATURES THROUGH THE FIRST HALF OF THE UPCOMING WEEK. GIVEN THE DEGREE OF DRY WEATHER...HAVE OPTED TO TREND TEMPERATURES SLIGHTLY ABOVE GUIDANCE FOR HIGHS EACH DAY...WHILE STAYING UNDER GUIDANCE FOR LOWS AT NIGHT...ESPECIALLY IN THE VALLEYS. THIS MEANS WE SHOULD SEE HIGHS AT OR ABOVE 70 FROM TUESDAY ONWARD...MAKING FOR A VERY PLEASANT STRETCH OF WEATHER. A WASHED OUT FRONTAL BOUNDARY WILL DROP SOUTH ACROSS THE AREA ON THURSDAY...BUT THE FEATURE CONTINUES TO TREND WEAKER...AND WILL LIKELY HAVE MINIMAL IMPACT ON THE WEATHER ACROSS EASTERN KENTUCKY. HIGH PRESSURE WILL THEN QUICKLY REBUILD AS WE HEAD INTO NEXT WEEKEND...WITH THE MILD WEATHER CONTINUING INTO NEXT WEEKEND. MAIN WEATHER IMPACT WE WILL SEE THIS WEEK...IS THE CONTINUATION OF THE DRY CONDITIONS WITH AFTERNOON RELATIVE HUMIDITIES FALLING TO BETWEEN 20 AND 30 PERCENT. ITS LIKELY A FEW RH READINGS INTO THE TEENS MAY BE POSSIBLE. WILL CONTINUE TO HIGHLIGHT THE LOW AFTERNOON RELATIVE HUMIDITIES IN THE FIRE WEATHER FORECAST. FORTUNATELY...THE GRADIENT SHOULD REMAIN WEAK ENOUGH TO LIMIT OVERALL WIND POTENTIAL THROUGH THE WEEK...KEEPING WINDS UNDER 10 MPH. CONTINUED TO RUN DEWPOINTS UNDER GUIDANCE EACH AFTERNOON AS MODELS TYPICALLY DON`T HANDLE DEWPOINTS WELL IN THE AFTERNOON WITH GOOD MIXING. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 825 PM EDT SAT OCT 17 2015 HIGH PRESSURE WILL BRING VFR THROUGH THE PERIOD. A FEW STRATOCU NEAR 6KFT ARE ANTICIPATED DURING THE FIRST FEW HOURS OF THE PERIOD ACROSS THE NORTH AND EAST AFFECTING SYM AND SJS BUT THESE SHOULD DEPART. LIGHT WINDS ARE ALSO EXPECTED THROUGH THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 3 AM TO 9 AM EDT SUNDAY FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...KAS AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
220 PM EDT FRI OCT 16 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 220 PM EDT FRI OCT 16 2015 ...COLDEST AIR OF THE SEASON THUS FAR ARRIVES THIS WEEKEND... 17Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO THE OHIO VALLEY. THIS IS BRINGING COOLER AND DRIER AIR INTO EAST KENTUCKY ON NORTHWEST TO NORTH WINDS OF AROUND 10 MPH WITH GUSTS TO 15 MPH. THE HIGH HAS ALSO CLEARED THE SKIES AND PLENTY OF SUNSHINE IS SUPPORTING TEMPERATURES IN THE LOWER 60S ATTM WITH DEWPOINTS MIXING DOWN INTO THE UPPER 20S AND LOWER 30S. THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST AS THEY ALL EASE A TIGHTENING TROUGH TO OUR NORTH...INTO THE GREAT LAKES AND THEN TO EASTERN CANADA. HEIGHTS WILL FALL THROUGH THE OHIO VALLEY TONIGHT AND SATURDAY AS THIS TROUGH PASSES...THOUGH ANY ENERGY ASSOCIATED WITH IT WILL STAY NORTH OF KENTUCKY. GIVEN THE MODEL AGREEMENT HAVE FAVORED THE HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS...WITH SPECIAL EMPHASIS ON THE COOP MOS FROM THE GFS FOR POINT BASED LOWS EACH NIGHT. SENSIBLE WEATHER WILL BE RATHER QUIET THROUGH THE WEEKEND WITH THIS MAINLY A TEMPERATURE FORECAST AS EVEN THE CLOUDS WILL BE FEW AND FAR BETWEEN. HOWEVER...A CANADIAN HIGH PRESSURE SYSTEM IN PLACE DURING THIS TIME OF YEAR WILL ALSO MEAN CHILLY LOW TEMPERATURES AND LIKELY FROST. IN FACT...THAT IS EXACTLY WHAT EAST KENTUCKY IS FACING TONIGHT AND SATURDAY NIGHT. DO EXPECT TEMPERATURES TO BE MORE UNIFORM TONIGHT THAN TOMORROW NIGHT WITH A SMALL RIDGE TO VALLEY DIFFERENCE BY MORNING...THOUGH READINGS IN THE VALLEYS WILL FALL INTO THE LOW 30S WITH AREAS OF FROST FORMING INTO SATURDAY MORNING. FOR THIS REASON A FROST ADVISORY HAS BEEN HOISTED TONIGHT FOR THE CWA. AFTER A COOL AND CLOUD FREE DAY ANOTHER COLD NIGHT WILL SET UP SATURDAY NIGHT WITH A LARGER RIDGE TO VALLEY TEMPERATURE SPLIT. THIS WILL LIKELY RESULT IN TEMPS DOWN TO THE MID 20S IN THE SHELTERED VALLEYS AND NEAR FREEZING ON THE RIDGES. THIS WILL ALSO BRING ABOUT WIDESPREAD FROST AND POTENTIALLY END THE GROWING SEASON...CERTAINLY EXPECT THAT TO BE THE CASE IN THE VALLEYS. ACCORDINGLY...WILL CONTINUE THE FREEZE WATCH FOR SATURDAY NIGHT INTO SUNDAY MORNING. USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR T AND TD GRIDS INTO SATURDAY MORNING WITH THE SUPERBLEND USED THEREAFTER. DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND SATURDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY DIFFERENCES. AS FOR POPS...WENT ZERO THROUGH THE SHORT TERM PERIOD...IN LINE WITH ALL GUIDANCE. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 215 PM EDT FRI OCT 16 2015 HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION THROUGH THE EXTENDED PERIOD OF THE FORECAST WITH RIDGE/VALLEY SPLITS IN TEMPERATURES. LOOKS LIKE SOME DRY AFTERNOONS SHAPING UP WITH RH`S UNDER 25 PERCENT EACH DAY THROUGH AT LEAST WEDNESDAY. LOOKS LIKE FREEZING TEMPERATURES CAN BE EXPECTED AGAIN SUNDAY NIGHT...SO WILL LIKELY NEED TO CARRY SOME HEADLINES AGAIN SUNDAY NIGHT. AT THIS POINT...WILL CONTINUE TO FOCUS ON FROST/FREEZE ISSUES IN THE SHORT TERM. A WEAK FRONT WILL WASH OUT AS IT MOVES INTO THE OHIO RIVER VALLEY ON THURSDAY...BUT MODELS CONTINUE TO TREND DRIER WITH THIS FEATURE...SO WILL MAINTAIN A DRY FORECAST THROUGH NEXT FRIDAY. OTHERWISE...EXPECT SLOWLY WARMING TEMPERATURES THROUGH NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 145 PM EDT FRI OCT 16 2015 NOW THAT THE FRONT IS WELL SOUTH OF THE AREA SKIES ARE CLEAR THROUGH EAST KENTUCKY AND CONDITIONS WILL STAY VFR INTO SATURDAY UNDER THE INFLUENCE OF COOL AND DRY HIGH PRESSURE. WINDS WILL BE OUT OF THE NORTH AT 5 TO 10 KTS...WITH SOME HIGHER GUSTS OF AROUND 15 KTS...THROUGH DUSK. THESE WILL DIMINISH TO 5 KTS OR LESS FOLLOWING SUNSET AND STAY THAT WAY THROUGH THE NIGHT. LOOK FOR THEM TO PICK UP...STILL OUT OF THE NORTH...AT 5 TO 10 KTS BY LATE SATURDAY MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 3 AM TO 9 AM EDT SATURDAY FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
223 AM EDT FRI OCT 16 2015 .UPDATE... ISSUED AT 223 AM EDT FRI OCT 16 2015 ISOLATED POCKETS OF LIGHT RAIN CONTINUE TO STREAM IN FROM THE WEST ACROSS SOUTH CENTRAL KENTUCKY...MAINLY AFFECTING LOCATIONS ALONG AND SOUTH OF THE HAL ROGERS PARKWAY AND HIGHWAY 80 CORRIDORS. COOLER VALLEY TEMPERATURES HAVE GENERALLY MIXED OUT FROM EARLIER LOWS...ALTHOUGH THERE IS STILL SOME RADIATIONAL COOLING BATTLING TRYING TO BATTLE IN THE SOME OF THE DEEPER NORTHEAST VALLEYS...AS EVIDENT AT THE PAINTSVILLE MESONET IN THE PAST COUPLE OF HOURS. THE BROADER VALLEYS AND RIDGETOPS ARE GENERALLY RANGING FROM 55 TO 60 DEGREES...SO CURRENT FORECAST LOWS IN THE 40S SEEM LIKE A REACH AT THIS POINT. HAVE USED SOME OF THE BLENDED SHORT TERM GUIDANCE FOR THE REST OF THE HOURLY TEMPERATURES...WHICH SUGGESTS CONTINUED MIXING...BEFORE DROPPING OFF TOWARDS DAWN BEHIND THE COLD FRONT. LOWS WOULD BE MORE IN THE UPPER 40S AND LOWER 50S...WITH ANY MID 40S RESTRICTED TO THE BLUEGRASS. THIS SEEMS REASONABLE BASED ON THE UPSTREAM TRENDS IN OBSERVATIONS. UPDATE ISSUED AT 1000 PM EDT THU OCT 15 2015 A FEW SPRINKLES ARE BEGINNING TO MOVE INTO EASTERN KENTUCKY WITH THE ROWAN COUNTY MESONET ALREADY RECORDING A TRACE OF PRECIP. OTHERWISE...MOST PLACES SHOULD REMAIN DRY FOR THE NEXT COUPLE OF HOURS OR SO...ESPECIALLY SINCE IT HAS TO OVERCOME SOME DRY AIR. THAT BEING SAID...NUDGED POP/SKY GRIDS TOWARDS THE HIGH RES HRRR MODEL AND FRESHENED UP THE T/TD GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 655 PM EDT THU OCT 15 2015 SPRINKLES AND CLOUD COVER CONTINUE THEIR PUSH TOWARD CENTRAL KENTUCKY THIS EVENING. BUT FOR THE NEAR TERM...SKIES WILL REMAIN MOSTLY CLEAR AND THE GROUND WILL REMAIN DRY. THAT BEING SAID...FORECAST REMAINS ON TRACK. DID A QUICK UPDATE TO ALIGN T/TD GRIDS WITH OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 330 PM EDT THU OCT 15 2015 18Z SFC ANALYSIS SHOWS HIGH PRESSURE NOW OVER EASTERN KENTUCKY AND TENNESSEE WITH CLEAR SKIES...LIGHT WINDS...AND LOW DEW POINTS IN PLACE. TO THE NORTHWEST...A LOW PRESSURE AREA IS MOVING THROUGH THE GREAT LAKES WITH A DRY COLD FRONT CUTTING SOUTHEAST ACROSS THE UPPER MIDWEST AND MID MISSISSIPPI VALLEY. LOCALLY...THE FULL SUNSHINE AND DRY AIR HAS ALLOWED TEMPERATURES TO CLIMB INTO THE UPPER 60S AND LOWER 70S. THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE BASE OF THE BROAD NORTHEAST NORTH AMERICAN TROUGH SWEEPING INTO THE OHIO VALLEY LATE TONIGHT IN CONJUNCTION WITH A SHORTWAVE ROUNDING ITS WESTERN BASE. THIS WAVE...AND THE ENERGY ASSOCIATED WITH IT... THEN PASSES OVER EASTERN KENTUCKY FRIDAY MORNING WITH THE WHOLE TROUGH DESCENDING FURTHER SOUTH THROUGH THE OHIO VALLEY. GIVEN THE GENERAL MODEL AGREEMENT HAVE FAVORED THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX DETAILS. SENSIBLE WEATHER WILL FEATURE A MOSTLY CLEAR EVENING WITH LIKELY A QUICK DROP OFF IN TEMPERATURES FOR THE VALLEYS IN THIS DRY ENVIRONMENT. THIS WILL SET UP A GOOD RIDGE TO VALLEY TEMPERATURE SPLIT INTO THE EARLY MORNING HOURS BEFORE INCREASING CLOUDS...WITH THE APPROACH OF A MOSTLY DRY COLD FRONT...HELP MIX OUT THE COLDER VALLEY TEMPERATURES. THE FRONT WILL ALSO BRING A SMALL CHANCE FOR STRAY SHOWERS...BUT MAINLY ONLY A FEW SPRINKLES...TO THE AREA LATE TONIGHT INTO DAWN. THIS MINOR PCPN THREAT PASSES OUT OF EAST KENTUCKY EARLY FRIDAY WITH CLEARING ALSO QUICKLY TAKING PLACE. THANKS TO RETURNING SUNSHINE...HIGHS WILL REBOUND INTO THE LOW TO MID 60S DESPITE POST FRONTAL CAA THROUGH THE DAY. THIS WILL SET THE STAGE FOR A CHILLY NIGHT INTO SATURDAY MORNING WITH READINGS SETTLING IN THE MID 30S FOR MANY VALLEY LOCATIONS AND FROST A GOOD BET IN THESE SPOTS BY DAWN. USED THE SHORTBLEND GUIDANCE AS A STARTING POINT INTO FRIDAY MORNING...BUT DID NEED TO ADJUST THE T GRIDS TO REFLECT THE VALLEY TEMPERATURE DROP OFF THIS EVENING. FOR THE REST OF THE SHORT TERM...FOLLOWED THE SUPERBLEND FOR T AND TD GRIDS. AS FOR POPS...ENDED UP SIMILAR TO RATHER LOW POPS TONIGHT INTO FRIDAY MORNING AND LOW SINGLE DIGITS OUTSIDE OF THAT TIME FRAME. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 315 PM EDT THU OCT 15 2015 ...HARD FREEZE EXPECTED SATURDAY AND SUNDAY NIGHTS... MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED FORECAST PERIOD. HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH THE WEEKEND. GIVEN THE DEGREE OF DRY AIR IN PLACE WITH PW`S DROPPING TO AROUND OF A QUARTER OF AN INCH BY DAYBREAK SUNDAY...FROST/FREEZE CONCERNS ARE FRONT AND CENTER. MOS GUIDANCE HAS THE COLDER VALLEYS DIPPING INTO THE MID 20S WHICH SEEMS REASONABLE GIVEN THE HIGH WILL BE VIRTUALLY OVERHEAD. THUS...WILL CONTINUE TO HIGHLIGHT THE FREEZE POTENTIAL IN THE HWO AND PLAN TO ISSUE AN SPS TO START HIGHLIGHTING THE THREAT EVEN MORE. A FREEZE WATCH MAY BE NEEDED IN THE NEXT 24 HOURS. GIVEN THE COLD TEMPERATURES...WE SHOULD SEE FROST DEVELOPMENT FAVORED OVER FOG...EXCEPT PERHAPS NEAR BODIES OF WATER. WHILE THE HIGH WILL MOVE TO THE EAST BY SUNDAY NIGHT...GRADIENT WILL STILL REMAIN SOMEWHAT WEAK TO SUPPORT SIMILAR TEMPERATURES IN THE VALLEYS. THUS...IT LOOKS LIKE TWO CONSECUTIVE NIGHTS OF FREEZING TEMPERATURES ARE LIKELY. AS THE HIGH CONTINUES TO SHIFT EAST INTO NEXT WEEK...THE AIR MASS WILL MODERATE WITH THE THREAT OF FROST/FREEZE CONDITIONS DEPARTING. DRY WEATHER WILL CONTINUE THROUGH THE WEEK. MODELS SHOW ANOTHER WEAK FRONT DIVING SOUTH ACROSS THE AREA ON THURSDAY...BUT 12Z GFS HAD THIS FRONT DRY AND THE ECMWF KEEPS THE BETTER FORCING TO THE NORTH. THUS...KEPT THE FORECAST DRY FOR NOW. AS FOR TEMPERATURES THE PERIOD WILL START OUT WELL BELOW NORMAL WITH SOME RECORD LOWS WITHIN REACH SATURDAY AND SUNDAY NIGHT...THEN SLOWLY WARM AS WE HEAD THROUGH THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 223 AM EDT FRI OCT 16 2015 A PASSING COLD FRONT WILL BRING LIGHT RAIN AND CEILINGS DOWN TO AROUND 5-6K FEET AGL IN PLACES THROUGH 12Z...PARTICULARLY ALONG AND SOUTH OF THE HAL ROGERS PARKWAY. THE FRONT AND THICKER CLOUD COVER WILL EXIT FROM NORTHWEST TO SOUTHEAST BETWEEN 12 AND 15Z...WITH CLEAR SKIES FOLLOWING. WINDS WILL TURN TO THE NORTHWEST AT 5 TO 10 KTS...WITH SOME HIGHER GUSTS POSSIBLE DURING PEAK MIXING IN THE AFTERNOON. HIGH PRESSURE WILL BUILD IN ACROSS THE AREA TONIGHT...WITH WINDS GRADUALLY LIGHTENING TO LESS THAN 5 KTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...GREIF LONG TERM...KAS AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
715 AM EDT FRI OCT 16 2015 .SYNOPSIS... WEAK LOW WILL TRACK NORTH OF THE AREA THIS MORNING. ANOTHER LOW IS EXPECTED TO SLOWLY INTENSIFY ON SATURDAY INTO SUNDAY AS IT CROSSES DOWNEAST MAINE AND MOVES INTO THE CANADIAN MARITIMES. CANADIAN HIGH PRESSURE WILL THEN RIDGE OVER THE REGION ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... 705 AM: WE NOTED THAT THE MAIN AREA OF RN OVR THE N IS MOVING OUT 2 TO 3 HRS SOONER THAN THE PREV FCST...SO WE WENT TO SHWRS FOR LESS THAN CATEGORICAL POPS FOR ALL OF THE REGION AFT ADVCG THE TMG OF POPS BY 2 TO 3 HRS. HRRR SIM HRLY FCST REF INDICATES THE POTENTIAL OF SHWRS FOR THE FA AHEAD OF THE COLD FRONT UNTIL ITS PASSAGE FROM MIDDAY NW TO MID AFTN FAR SE. OTHERWISE...ONLY MINOR CHGS TO FCST HRLY TEMPS INTO THE AFTN HRS BASED ON TRENDS SEEN AT 6 AM OBSVD TEMPS. ORGNL DISC: NO SIG CHGS TO FCST QPF AND POPS INTO THIS AFTN...WITH RN MSLY ENDING ACROSS THE N BEFORE COLDER AIR ARRIVES FOR ANY TRANSITION TO SN SHWRS. HI TEMPS MAY OCCUR ARND MIDDAY TO ERLY AFTN BEFORE DROPPING LATER THIS AFTN LONG BEFORE SUNSET WITH THE ARRIVAL OF LLVL COLD ADVCN SW OF THE DEPARTING SFC THRU NRN NEW BRUNSWICK. SOME CLRG XPCTD THIS EVE WITHE FA BETWEEN SFC LOW PRES-S/WV ALF SYSTEMS...THEN WE XPCT CLOUDINESS TO INCREASE LATER TNGT AHEAD OF THE NEXT S/WV AND SFC LOW FROM THE UPPER GREAT LKS...WITH LGT SN OR RN-SN MIX MOVING INTO W CNTRL PTNS OF THE FA JUST PRIOR TO SUNRISE SAT. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... SNOW RETURNS TO THE FORECAST FOR NORTHERN ZONES ON SATURDAY. SURFACE LOW PRESSURE IS EXPECTED TO TRACK FROM SOUTHERN QUEBEC TO DOWN EAST MAINE AND ONWARD INTO NEW BRUNSWICK ON SATURDAY. SNOW WILL OCCUR NORTH OF THE LOW`S TRACK WHILE RAIN WILL FALL ELSEWHERE. HIGHS WILL RANGE FROM THE MID 30S IN THE ALLAGASH TO AROUND 50F FOR BANGOR AND THE COAST. AS ALWAYS THIS TIME OF YEAR....TIME OF DAY AND ELEVATION WILL BE KEY TO SNOW ACCUMULATIONS. SINCE MOST OF SNOW WILL FALL DURING THE DAY...THE COMBINATION OF WARM SURFACES AND A WARM BOUNDARY LAYER WILL REDUCE ACCUMULATIONS. HIGHER TERRAIN IN THE ALLAGASH AND KATAHDIN REGION COULD EASILY RECEIVE 3 INCHES OR MORE...BUT MORE POPULATED AREAS SUCH AS CARIBOU AND PRESQUE ISLE WILL LIKELY RECEIVE JUST OVER AN INCH OF ACCUMULATION. THIS WILL LIKELY OCCUR LATER IN THE AFTERNOON ON THE BACKSIDE OF THE LOW. FURTHER SOUTH TOWARDS HOULTON...THE EXPECTATION IS FOR MOSTLY RAIN UNTIL LATER IN THE AFTERNOON WHEN THE LOW MOVES EAST AND COOLER AIR ARRIVES. THE HEAVIEST ACCUMULATIONS WILL LIKELY BE IN A BAND FROM NORTHERN SOMERSET COUNTY TOWARDS THE KATAHDIN REGION AND EAST TO MARS HILL. SOUTH OF A LINE FROM MILLINOCKET TO FAR SOUTHERN AROOSTOOK COUNTY...LITTLE OR NO ACCUMULATION IS FORECAST. COLD AIR FILTERS INTO THE AREA THROUGH SATURDAY NIGHT WITH SOME RESIDUAL SNOW SHOWERS AND TEMPERATURES FALLING INTO THE UPPER 20S TO LOWER 30S. TEMPERATURES WILL ONLY RECOVER TO THE UPPER 30S TO LOWER 40S ON SUNDAY WITH FLURRIES IN NORTHERN ZONES. SUNDAY NIGHT WILL BE COLDEST NIGHT OF THE SEASON WITH CLEARING SKIES. TEENS ARE PROBABLE IN THE ALLAGASH WHILE LOW TO MID 20S ARE ANTICIPATED ELSEWHERE. && .LONG TERM /MONDAY THROUGH THURSDAY/... HIGH PRESSURE AT THE SURFACE AND ALOFT CRESTS OVER THE AREA MONDAY WITH SUNNY SKIES AND COOL HIGH TEMPERATURES IN THE LOWER 40S. TEMPERATURES WILL DROP OFF INTO THE UPPER 20S MONDAY NIGHT WITH CLEAR SKIES AND LIGHT WINDS...BUT INCREASING CLOUDS LATER WILL PROVIDE THE CHANCE OF A BRIEF PERIOD OF SNOW LATE. WARM AIR ADVECTION AHEAD OF A COLD FRONT WILL PROMPT A QUICK CHANGEOVER TO ALL RAIN TUESDAY MORNING. THE FRONT ITSELF WILL PROBABLY CROSS TOWARDS EVENING...BUT WILL TEND TO WEAKEN AND HAVE REDUCED POPS AS THE DAY PROGRESSES. TEMPERATURES WILL MODERATE INTO UPPER 40S TO LOWER 50S ON TUESDAY. IT WILL BE SLIGHTLY COOLER BEHIND THE FRONT ON WEDNESDAY WITH HIGH PRESSURE. THE NEXT SYSTEM WILL ARRIVE FOR THURSDAY. AT THIS POINT...THERE IS A POSSIBILITY OF MIXED PRECIP TOWARDS THE CROWN OF MAINE. && .AVIATION /11Z FRIDAY THROUGH TUESDAY/... NEAR TERM: MVFR DOWNEAST AND LOW MVFR/IFR NRN TAF SITES TDY IN RN...THEN IMPROVING BACK TO VFR TNGT BEHIND ENDING RNFL. SHORT TERM: IFR TO LIFR IN SNOW NORTH OF HUL DUE TO SNOW. EXPECT MVFR IN SHOWERS SOUTH OF HUL. IT WILL BE VFR FROM SATURDAY NIGHT UNTIL MONDAY NIGHT. && .MARINE... NEAR TERM: WILL CONT WITH THE CURRENT SCA WITH WINDS AND WVS NOW APCHG MARGINAL SCA CRITERIA. AFT PEAKING WITH 25 KT WIND GUSTS AND MAX WV HTS OF UP TO 7 FT OVR THE OUTER WATERS THIS AFTN AND EVE... WINDS AND WVS SHOULD SUBSIDE BACK BELOW SCA CRITERIA LATE TONIGHT. SHORT TERM: SMALL CRAFT ADVISORIES WILL BE NEEDED SATURDAY THROUGH SUNDAY NIGHT...AND RETURN TUESDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ050>052. && $$ NEAR TERM...VJN SHORT TERM...MCW LONG TERM...MCW AVIATION...VJN/MCW MARINE...VJN/MCW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
149 AM EDT FRI OCT 16 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN CENTERED OVER THE SOUTHEAST STATES TONIGHT INTO FRIDAY. AN UPPER LEVEL TROUGH WILL PASS OVER THE MID ATLANTIC FRIDAY...AND PULL A STRONG COLD FRONT THROUGH THE REGION FRIDAY NIGHT. THIS WILL USHER IN COOL CANADIAN HIGH PRESSURE FOR THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... FORECAST REMAINS LARGELY ON TRACK...AND ONLY MINOR CHANGES HAVE BEEN MADE TO REFLECT 00Z OBS. PER LATEST IR/WV SAT IMAGERY...HAVE SLOWED DOWN INCREASING CLOUDS UNTIL AFTER 09Z /TOWARD DAWN/ ACROSS THE WEST, AND INTO LATER FRI MORNING ACROSS THE COASTAL PLAIN. PREVIOUS DISCUSSION... THE LATEST SURFACE ANALYSIS SHOWS ~1020MB HIGH PRESSURE CENTERED OVER THE SOUTHEAST STATES. 1004MB LOW PRESSURE IS CENTERED N OF LAKE HURON ASSOCIATED WITH A VIGOROUS MID/UPPER TROUGH PASSING THROUGH THE GREAT LAKES REGION...AND DRAGGING A STRONG COLD FRONT THROUGH THE UPPER MIDWEST. ADDITIONAL SHORTWAVE ENERGY IS DIVING THROUGH INTO THE MID-MISSISSIPPI VALLEY. HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST TONIGHT AND WILL REMAIN THE DOMINANT FEATURE LOCALLY. EXPECT A CLEAR TO MOSTLY CLEAR SKY...ALTHOUGH AN INCREASE IN HIGH CLOUDS IS POSSIBLE OVER THE PIEDMONT LATE. A LIGHT SW WIND AHEAD OF THE APPROACHING COLD FRONT WILL RESULT IN SLIGHT INCREASE IN LOW TEMPERATURES FROM LAST NIGHT...WITH MINIMA AVERAGING FROM THE MID/UPPER 40S INLAND...TO THE LOW/MID 50S FOR COASTAL AREAS OF SE VA/NE NC. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... DEEP LAYER ZONAL FLOW PREVAILS FRIDAY AS THE AFOREMENTIONED TROUGH APPROACHES FROM THE NW...AND THE SECONDARY SHORTWAVE ENERGY APPROACHES FROM THE W. 15/12Z GFS/ECMWF/NAM EACH DEMONSTRATE DECENT AGREEMENT WITH THIS SCENARIO. 15/12Z GFS/NAM FORECAST SOUNDINGS INDICATE MUCH OF THE MOISTURE IS CONCENTRATED BETWEEN 700-500MB...WITH RATHER DRY CONDITIONS BELOW THIS LAYER. OVERALL THIS PATTERN IS NOT FAVORABLE FOR PCPN...BUT A 20% POP FOR -SHRA WILL BE FORECAST FOR THE ENTIRE AREA GIVEN DECENT MID-LEVEL ENERGY. A MOSTLY CLOUDY PERIOD WILL ACCOMPANY THE TROUGH...WITH CLEARING EXPECTED FROM THE W AS THE TROUGH PULLS OFFSHORE LATER IN THE AFTERNOON. CONTINUED TO TREND HIGH TEMPERATURES DOWN FROM PREVIOUS FORECAST DUE TO EARLIER ONSET OF CLOUDS ACRS PORTIONS OF THE AREA...EXPECT HIGHS RANGE FROM THE UPPER 60S NORTH AND CENTRAL...TO THE LOWER TO MID 70S IN NE NC. A STRONGER COLD FRONT PUSHES THROUGH REGION FRIDAY EVENING...WITH CANADIAN HIGH PRESSURE BUILDING IN FROM THE NW SATURDAY. COOLER AIR FILTERS IN FRIDAY NIGHT WITH LOWS FALLING TO THE LOW 40S OVER THE PIEDMONT TO AROUND 50 ALONG THE COAST. 850MB TEMPERATURES DROP BELOW 0C ACROSS THE N DURING THE DAY SATURDAY...AND AVERAGE 2-4C ACROSS SRN PORTIONS. HIGH TEMPERATURES SHOULD RANGE FROM THE UPPER 50S NW...TO THE LOW/MID 60S SE UNDER A MOSTLY SUNNY SKY. CANADIAN HIGH PRESSURE (1030+ MB) CONTINUES TO BUILD IN SATURDAY NIGHT AND SETTLES OVER THE AREA SUNDAY. THE BEST POTENTIAL FOR DECOUPLING (AND POTENTIAL FREEZE) WILL BE OVER THE PIEDMONT SUNDAY MORNING WHERE LOW ARE FORECAST TO FALL INTO THE LOW 30S...WITH MID/UPPER 30S FARTHER E...AND LOW/MID 40S FOR SE COASTAL AREAS. COOL AND SUNNY SUNDAY WITH HIGHS RANGING FROM THE MID 50S N...TO NEAR 60 S...OR ABOUT -1.5 ST DEV BELOW SEASONAL MEANS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... DRY CONDITIONS WILL CONTINUE THROUGH THE PERIOD AS HIGH PRESSURE REMAINS IN CONTROL OF THE WX PATTERN OVER THE MID-ATLANTIC STATES. THE COLDEST TEMPS SO FAR THIS SEASON ARE EXPECTED SUNDAY NIGHT AS HIGH PRESSURE CENTERS ITSELF OVER PA. BOTH THE GFS AND ECMWF STILL ADVERTISE H85 TEMPS HOVERING BETWEEN 0 C OVER ERN NC TO -4 C ACROSS THE MD ERN SHORE. THIS IS -2 TO -2.5 STD DEV FOR THIS TIME OF YEAR. LOWS TEMPS SUN NIGHT ARE EXPECTED TO REACH 30-34 DEG FOR MOST INTERIOR LOCATIONS...TO THE LOW 40S ALONG THE IMMEDIATE COAST. IF THIS TREND CONTINUES THEN FREEZE HEADLINES WILL LIKELY BE NECESSARY FOR AREAS ALONG AND WEST OF I-95 MON MORNING. WIDESPREAD FROST WOULD ALSO BE LIKELY. THE COOL HIGH PRESSURE SLIDES OVER THE LOCAL AREA ON MONDAY WITH MAX TEMPS NO BETTER THAN THE MID 50S. TEMPS MON NIGHT REMAIN CHILLY WITH LOWS IN THE LOW/MID 30S INLAND...TO LOW 40S AT THE COAST. HIGH PRESSURE PUSHES OFFSHORE TUES AS AN UPPER TROUGH SLOWLY APPROACHES FROM THE WEST. RETURN/SLY FLOW ON THE BACK SIDE OF THE DEPARTING HIGH WILL RESULT IN A WARMING TREND INTO THE MIDDLE OF NEXT WEEK. HIGHS TUES ARE EXPECTED TO BE IN THE MID 60S...WITH 60S TO LOW 70S FOR NEXT WED/THU. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE CENTERED OVER THE SOUTHEAST STATES HAS RESULTED IN SKC CONDITIONS AND LIGHT SLY WINDS AOB 10 KT EARLY THIS MORNING. A COLD FRONT CURRENTLY LOCATED OVER THE OH VALLEY WILL DROP INTO THE MID-ATLANTIC REGION LATER THIS MORNING. INCREASE IN MID-LEVEL CLOUDS AROUND 8 TO 12K FT AGL WILL ACCOMPANY THE FRONT AS IT REACHES THE LOCAL AREA. COLD FRONT PUSHES ACROSS THE REGION THIS MORNING...PUSHING OFFSHORE EARLY AFTERNOON. ASIDE FROM BKN-OVC MID LEVEL CLOUDS...SFC WINDS BACK TO THE NW BUT REMAIN AOB 10 KT. THERE IS A SLIGHT CHANCE FOR SHOWERS/SPRINKLES ALONG THE FRONT. SKY RETURNS TO SKC LATE AFTERNOON INTO THE EVENING HOURS. OUTLOOK...DRY WEATHER IS FORECAST THROUGH EARLY NEXT WEEK WITH SIGNIFICANTLY COOLER WEATHER. GUSTY NW WINDS ARE EXPECTED AT TIMES OVER THE WEEKEND. WINDS DIMINISH AS HIGH PRESSURE SETTLES OVER THE REGION BY LATE SUNDAY AND MONDAY. DRY AND MAINLY VFR CONDITIONS ARE EXPECTED INTO EARLY NEXT WEEK. && .MARINE... SCA ISSUED FOR THE BAY FROM 1 AM TO 1 PM FRIDAY. RAP AND HRRR SUPPORT THIS AND SW WINDS SHOULD MIX WELL WITH AIR TEMPERATURE ABOUT SIX DEGREES COOLER THAN THE WATER. GUSTS TO 20 KNOTS ARE EXPECTED TO BE MAINLY OVER THE ERN PORTION OF THE BAY AS INDICATED BY RAP. MODELS HAVE WINDS DIMINISH QUICKLY IN THE LATE MORNING AND THE MRNG FORECASTER MIGHT BE ABLE TO DROP THE SCA AT 10 AM IF THIS IS THE CASE. PREVIOUS DISCUSSION... HIGH PRESSURE OVER THE AREA NOW PUSHES FARTHER OFFSHORE TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST. SW WINDS RAMP UP LATE TONIGHT INTO FRI MORNING...BUT ARE EXPECTED TO REMAIN AOB 15 KT. WAVES 1-2 FT AND SEAS 2-4 FT. SW WINDS 10-15 KT CONTINUE INTO EARLY FRI AFTERNOON BEFORE A COLD FRONT CROSSES THE REGION FRI AFTERNOON/EVENING. LOW LEVEL CAA KICKS IN LATE FRI NIGHT AS STRONG CANADIAN HIGH PRESSURE BUILDS OVER THE OH VALLEY. HOWEVER...ANY SCA CONDITIONS WOULD BE BRIEF AND MOSTLY LIKELY LIMITED TO THE CHES BAY AND PERHAPS NORTHERN COASTAL ZONES. WINDS ARE THEN SHOWN TO DIMINISH A BIT ON SATURDAY BEFORE RAMPING UP AGAIN SAT NIGHT THRU SUN NIGHT AS A REINFORCING SHOT OF COLD AIR ARRIVES. NWLY WINDS GENERALLY 15 TO 25 KT WITH SEAS 4 TO 6 FT AND WAVES 3 TO 4 FT SAT NIGHT THRU SUN NIGHT. THE HIGH FINALLY SETTLES OVER THE WATERS ON MONDAY. SUB-SCA CONDITIONS ARE FORECAST TO RETURN LATE MONDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK AS HIGH PRESSURE REMAINS OVER THE REGION. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ630>632-634. && $$ SYNOPSIS...AJZ/LKB NEAR TERM...AJZ/MAM SHORT TERM...AJZ/LKB LONG TERM...JDM AVIATION...SAM MARINE...JDM/LSA
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
914 AM MDT FRI OCT 16 2015 .UPDATE... MADE A FEW ADJUSTMENTS FOR THE MORNING FORECAST UPDATE. AFTER A COLD START WITH MANY READINGS IN THE 20S...MIXING WILL BE LIMITED TO AROUND 800 MB TODAY BASED ON RAP SOUNDINGS AND LOW-LEVEL E FLOW. KBIL WILL LIKELY END UP WITH CLARKS FORK DRAINAGE THROUGH THE DAY WITH A MORE SSW WIND DIRECTION. IN ADDITION TO THE POOR MIXING...HIGH CLOUDS WILL MOVE INTO THE AREA ESPECIALLY OVER THE EASTERN ZONES. KGGW 12Z RAOB SHOWED A MOISTURE LAYER AT 400 MB. USING THE GFS...THIS MOISTURE WAS FORECAST TO MOVE INTO THE FORECAST AREA. HAVE ADJUSTED SKY COVER TO ACCOUNT FOR THIS. THE COMBINATION OF INCREASED CLOUD COVER AND POOR MIXING WILL LIMIT TEMPERATURE RISES SOMEWHAT...SO HAVE LOWERED HIGHS A COUPLE OF DEGREES. ALSO MORNING DEWPOINTS WERE IN THE 20S AND WILL NOT MAKE MUCH HEADWAY BASED ON RAP SOUNDINGS. HAVE LOWERED THESE AS WELL. REMAINDER OF FORECAST WAS IN GOOD SHAPE WITH SUNNY AND WARMER CONDITIONS EXPECTED FOR SAT. ARTHUR && .SHORT TERM...VALID FOR TDY AND SAT... A TRANQUIL NEXT COUPLE OF DAYS ARE IN STORE ACROSS THE FORECAST AREA. HIGH PRESSURE RIDGING HAS SETTLED ACROSS THE AREA OVERNIGHT RESULTING IN CLEAR SKIES ALONG WITH CALM TO VERY LIGHT WINDS. TEMPERATURES HAVE DROPPED INTO THE MIDDLE AND UPPER 20S ACROSS OUR FAR EAST WITH 30S ELSEWHERE RESULTING IN THE FIRST FROST AND FREEZE OF THE SEASON FOR MANY AREAS. HIGH PRESSURE RIDGING WILL CONTINUE TO BUILD ACROSS THE FORECAST AREA TODAY AND SATURDAY. THIS WILL RESULT IN MOSTLY SUNNY SKIES BOTH DAYS ALONG WITH MODERATING TEMPERATURES. A LIGHT EASTERLY OR VARIABLE WIND WILL PREVAIL FOR THE NEXT COUPLE OF DAYS. AFTERNOON HIGHS TODAY WILL BE IN THE UPPER 50S TO LOWER 60S NEAR THE DAKOTA BORDERS TO LOWER 70S ACROSS THE FAR WESTERN ZONES. HIGHS SATURDAY WILL BE WARMER WITH READINGS IN THE MIDDLE 60S TO MIDDLE 70S. HOOLEY .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... MODELS IN REASONABLE AGREEMENT THROUGH THE EXTENDED PERIOD. SUNDAY SHOULD BE THE WARMEST DAY WITH HIGHS WELL INTO THE 70S AHEAD OF A SUNDAY NIGHT COLD FRONTAL PASSAGE...WITH MIXING AIDED BY HEIGHT FALLS AND A SHIFT TO W-NW WINDS DURING THE AFTERNOON. HAVE ADJUSTED FORECAST HIGHS UP A LITTLE MORE. DAILY RECORDS ON THE 18TH ARE IN THE LOWER 80S AND SHOULD NOT BE REACHED...BUT WE WILL BE WELL ABOVE NORMAL. THE POTENTIAL FOR SHOWERS WILL BEGIN TO INCREASE IN OUR WEST SUNDAY AND SUNDAY NIGHT AS AN INITIAL WEAK SHORTWAVE KICKS THROUGH THE REGION...ALTHOUGH MAIN TROF WILL STILL BE TO OUR WEST. THIS TROF WILL SLIDE EAST AND BRING US A GOOD CHANCE OF SHOWERS MONDAY AND TUESDAY. ASCENT LOOKS TO BE STRONGEST LATE MONDAY AND MONDAY NIGHT AS A WEAK MID LEVEL CIRCULATION FORMS AND COULD BRING A BRIEF PERIOD OF EASTERLY FLOW THROUGH 700MB OVER OUR WEST. THOUGH NOT OVERLY DYNAMIC...THIS TROF WILL BE ACCOMPANIED BY HIGH PWATS SO HAVE BUMPED UP POPS A BIT MORE ESPECIALLY FOR OUR WEST HALF. IT SHOULD ALSO BE NOTED THAT THIS WILL BE A RATHER WARM SYSTEM FOR MID OCTOBER WITH 700MB TEMPS STAYING ABOVE ZERO UNTIL MONDAY NIGHT. SO LOOKS LIKE RAIN SHOWERS CHANGING TO RAIN/SNOW OVER THE MOUNTAINS WITH SOME SNOW ACCUMULATION ABOVE 8-9KFT LATE MONDAY NIGHT INTO EARLY TUESDAY. LOWER ELEVATIONS WILL REMAIN RAIN OF COURSE. HIGH TEMPS SHOULD COOL TO THE 60S MONDAY AND MID 50S TO NEAR 60F TUESDAY. HEIGHTS WILL REBUILD AND WE SHOULD SEE DRY CONDITIONS WITH A WARMING TREND WEDNESDAY AND THURSDAY COURTESY OF RIDGING ALOFT. GOOD MODEL CONSENSUS HERE. SHOULD SEE HIGH TEMPS CREEP BACK TOWARD 70F BY THURSDAY. LOOKING FURTHER AHEAD...THERE IS POTENTIAL FOR A STRONGER/WETTER SYSTEM TO COME OFF THE PACIFIC BY NEXT WEEKEND...BUT THERE IS PLENTY OF UNCERTAINTY IN ANY SPECIFICS THIS FAR IN ADVANCE. JKL && .AVIATION... STRONG HIGH PRESSURE ALOFT WILL RESULT IN VFR CONDITIONS ACROSS THE AREA TODAY AND TONIGHT. JKL/RMS && .PRELIMINARY POINT TEMP/POPS... TDY SAT SUN MON TUE WED THU ------------------------------------------------------- BIL 061 041/072 049/076 048/063 045/058 039/063 044/068 0/B 00/U 01/E 23/W 43/W 11/U 11/B LVM 070 039/078 048/072 044/060 040/055 037/063 040/068 0/U 00/U 03/W 45/W 53/W 11/B 11/B HDN 064 038/074 042/079 045/066 043/060 037/065 040/071 0/B 00/U 00/B 23/W 43/W 11/U 01/B MLS 060 035/069 040/077 045/065 045/060 039/061 043/070 0/B 00/U 00/B 11/B 33/W 21/U 01/B 4BQ 065 036/069 044/078 045/066 045/059 038/061 042/070 0/B 00/U 00/B 11/B 33/W 21/U 01/B BHK 057 032/064 038/075 044/064 043/058 038/059 041/066 0/B 00/U 00/B 01/B 33/W 21/U 01/B SHR 066 038/075 043/078 043/067 042/058 037/062 038/069 0/B 00/U 01/B 23/W 43/W 11/U 01/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
855 PM PDT SAT OCT 17 2015 .SYNOPSIS...A BROAD LOW PRESSURE SYSTEM MOVING ACROSS CALIFORNIA AND NEVADA TONIGHT AND SUNDAY WILL BRING INCREASING COVERAGE OF SHOWERS AND SCATTERED THUNDERSTORMS TO MUCH OF THE REGION SUNDAY MORNING THROUGH SUNDAY AFTERNOON. ADDITIONAL UPPER LEVEL DISTURBANCES WILL CONTINUE TO PROVIDE UNSETTLED AND COOL CONDITIONS INTO THE MIDDLE OF NEXT WEEK. && .UPDATE...845 PM...MOST OF THE AREA IS FREE OF CONVECTION AT THIS HOUR...HOWEVER SHORT RANGE GUIDANCE SUGGEST THAT THIS WILL CHANGE OVER THE NEXT FEW HOURS. THE HRRR AND HRRRX HAVE BEEN FAIRLY CONSISTENT SHOWING AN UPTICK IN ACTIVITY ALONG AND WEST OF A LINE FROM BARSTOW TO TONOPAH BETWEEN 04Z AND 06Z THIS EVENING. THIS WILL BE IN RESPONSE TO UPPER LEVEL FORCING ENCOUNTERING AN UNSTABLE AIRMASS. EXPECT MUCH OF THIS ACTIVITY TO CONGEAL INTO A NORTH-SOUTH BAND OF SHOWERS WITH EMBEDDED THUNDERSTORMS BETWEEN 06Z AND 12Z AND SLOWLY PROGRESS EAST. BASED ON MODEL CONSENSUS...BY 12Z THIS LINE SHOULD STRETCH FROM ROUGHLY BAKER TO RACHEL. THROUGH SUNDAY THIS LINE WILL CONTINUE TO PUSH EAST...GRADUALLY PIVOTING TO A SSW-NNE ORIENTATION. AS THIS OCCURS THUNDERSTORM COVERAGE AND INTENSITY BOTH IN AND AHEAD OF THE BAND (MOHAVE AND EASTERN CLARK COUNTIES) IS LIKELY TO INCREASE WITH THE ADDITION OF DAYTIME HEATING. CURRENT GUIDANCE SUGGESTS THE MOST LIKELY TIMING FOR THIS BAND TO CROSS THE LAS VEGAS VALLEY WOULD BE FROM 19Z-23Z (12PM-4PM). FORECAST HAS BEEN TWEAKED TO ACCOUNT FOR THE LATEST MODEL ANALYSIS THROUGH SUNDAY. CURRENT FLASH FLOOD WATCH PLACEMENT AND TIMING APPEARS TO BE GOOD AND NO CHANGES TO THAT PRODUCT ARE EXPECTED AT THIS TIME. && .AVIATION...FOR MCCARRAN...WINDS LIKELY TO REMAIN LIGHT AND VARIABLE UNDER 8 KTS OVERNIGHT...THEN INCREASE TO 12-16KTS WITH GUSTS TO 25 KTS FROM THE SOUTH-SOUTHWEST AFTER 18Z. SHOWER AND THUNDERSTORM ACTIVITY WILL BE FAIRLY LIMITED THE REMAINDER OF THE NIGHT...BUT CANNOT BE COMPLETELY RULED OUT. CIGS OF 4-6K NEAR ANY SHOWER ACTIVITY TONIGHT...OTHERWISE SCT-BKN CLOUDS AT 6-8K FEET. CHANCES FOR SHRA/TSRA WILL INCREASE LATE SUNDAY MORNING AND PEAK BETWEEN 19Z- 23Z. CIGS OF 3-5K FEET ARE EXPECTED WITH THIS ACTIVITY ALONG WITH MOUNTAIN OBSCURATIONS. STORMS COULD BRING GUSTY WINDS IN EXCESS OF 35 KTS THESE STORMS...AS WELL AS REDUCED VSBY. SLIGHT CHANCES FOR SHRA/TSRA WILL CONTINUE THROUGH EARLY NEXT WEEK. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...ISOLATED SHRA/TSRA ARE POSSIBLE THROUGH TONIGHT. SHOWERS AND THUNDERSTORMS WILL BE FAVORED OVER CLARK...NYE...LINCOLN AND MOHAVE COUNTIES ON SUNDAY. GUSTS EXCEEDING 35 KTS ARE POSSIBLE WITH THUNDERSTORMS. CIGS WILL MAINLY BE 4K-6K FEET IN AND NEAR SHRA/TSRA OTHERWISE 8K-12K FEET. VSBY MAY BE REDUCED TO MVFR OR LOWER AND MOUNTAIN OBSCURATIONS ARE LIKELY IN AND NEAR ANY SHRA/TSRA. OUTSIDE OF TSRA EXPECT SOUTHWEST WINDS TO INCREASE TO 10- 20 KTS WITH GUSTS 20-30 KTS IN MOST LOCATIONS BY THE AFTERNOON. CHANCES FOR SHRA/TSRA WILL CONTINUE THROUGH EARLY NEXT WEEK...MAINLY FROM LAS VEGAS EAST. && .SHORT TERM...TONIGHT THROUGH MONDAY NIGHT. IT LOOKS LIKE THE INGREDIENTS ARE COMING TOGETHER FOR AN AN ACTIVE WEATHER DAY SUNDAY ACROSS SOUTHERN SOUTHERN NEVADA AND SURROUNDING AREAS OF NORTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. ANOMALOUSLY HIGH MOISTURE CONTENT WILL REMAIN IN PLACE ACROSS THE REGION WITH PWAT VALUES OF 1.0-1.3 INCHES AND SURFACE DEWPOINTS GENERALLY IN THE 60S. THE LIFTING MECHANISM NEEDED TO TURN THIS MOISTURE INTO SHOWERS AND THUNDERSTORMS IS COMING IN THE FORM OF A VIGOROUS LOW PRESSURE SYSTEM CURRENTLY OFF THE NORTHERN CALIFORNIA COAST. THE CENTER OF THIS BROAD SYSTEM IS FORECAST TO MOVE INLAND OVER NORTHERN CALIFORNIA SUNDAY BUT A VORT MAX AND 50-60 KNOT JET ROUNDING THE BASE OF THE LOW AND EJECTING UP ACROSS SOUTHERN NEVADA WILL PROVIDE PLENTY OF DYNAMIC FORCING COMBINED WITH SOME DESTABILIZATION DUE TO COOLER AIR ALOFT ASSOCIATED WITH THE SYSTEM. FORECAST SOUNDINGS LATE SUNDAY MORNING INDICATE CONSIDERABLE INSTABILITY WITH CAPE VALUES AROUND 1500-1800 J/KG...LIFTED INDICES AROUND -5 AND CONSIDERABLE SPEED SHEAR WITH THE STRENGTHENING SOUTH-SOUTHWEST FLOW. THIS SHOULD LEAD TO FAST MOVING FAIRLY ORGANIZED THUNDERSTORMS AND THE POTENTIAL FOR TRAINING CELLS WHICH WILL ELEVATE THE FLASH FLOOD THREAT. THIS COULD LEAD TO MORE THAN JUST LOCALIZED FLASH FLOOD POTENTIAL SUNDAY AND JUSTIFIES THE FLASH FLOOD WATCH THAT IS ALREADY IN EFFECT UNTIL SUNDAY EVENING. THE BEST WINDOW FOR THESE THINGS TO COME TOGETHER LOOKS TO BE BETWEEN 12Z AND 18Z THEN CONTINUING THROUGH SUNDAY AFTERNOON...SO WE SHOULD SEE AN EARLY START TO STORM DEVELOPMENT. AS THE VORT MAX CONTINUES LIFTING UP THROUGH UTAH SUNDAY EVENING... DRY SOUTHWEST FLOW ALOFT SHOULD GRADUALLY DECREASE MOISTURE CONTENT BUT ISOLATED TO SCATTERED SHOWERS WILL STILL BE POSSIBLE OVER SOUTHERN NEVADA AND NORTHWEST ARIZONA SUNDAY NIGHT INTO MONDAY MORNING. ADDITIONAL ENERGY IS FORECAST TO DIVE DOWN THE WEST COAST MONDAY AND DRAG THE TROUGH SOUTHWARD WHILE SPINNING IT UP INTO A CLOSED LOW CENTERED NEAR YUMA ARIZONA BY TUESDAY MORNING. THIS WILL PLACE MOHAVE COUNTY NEAR THE NORTHEAST QUADRANT OF THE LOW LEADING TO A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS. IN ADDITION...THIS WILL KEEP COOL TEMPERATURES IN PLACE ACROSS THE REGION WITH HIGHS 3-5 DEGREES BELOW NORMAL. .LONG TERM...TUESDAY THROUGH SATURDAY. YET ANOTHER SHORTWAVE TROUGH WILL BE CENTERED DIRECTLY OVER OUR AREA TO START THE LONG TERM PERIOD. THIS SHORTWAVE WILL SPIN UP INTO A CLOSED LOW CENTERED OVER THE LOWER COLORADO RIVER VALLEY ALONG THE CALIFORNIA/ARIZONA BORDER TUESDAY NIGHT AND BE NEARLY STATIONARY THROUGH WEDNESDAY. THIS WILL KEEP COOLER CONDITIONS AROUND THROUGH AT LEAST MID WEEK ALONG WITH A CHANCE OF SHOWERS CONTINUING OVER PORTIONS OF LINCOLN, CLARK, SAN BERNARDINO, AND MOHAVE COUNTIES. GIVEN THE FAIRLY GOOD MODEL AGREEMENT, DID EXPAND PRECIP CHANCES A LITTLE FARTHER WEST AND INCREASED POPS A BIT. THE LOW WILL THEN EDGE INTO CENTRAL ARIZONA THURSDAY AND FINALLY DEPART THURSDAY NIGHT INTO FRIDAY. COULD STILL SEE SOME SHOWERS LINGERING ACROSS NORTHWEST ARIZONA (PERHAPS SLIGHTLY FARTHER WEST) THURSDAY. HAVE GONE WITH AN AREA-WIDE DRY FORECAST FRIDAY AND FRIDAY NIGHT WITH MORE OF A QUASI- ZONAL FLOW ALOFT SETTING IN. THE 00Z MODELS SUGGEST DRY CONDITIONS MAY CONTINUE INTO SATURDAY BUT RUN-TO-RUN MODEL TRENDS HAVE NOT BEEN VERY GOOD. THERE ARE SIGNS THAT ANOTHER TROUGH MAY APPROACH OR SWING INTO THE SOUTHWEST AT SOME POINT NEXT WEEKEND. STILL A LOT OF UNCERTAINTY WITH TIMING AND JUST HOW DEEP/STRONG IT MAY BE. WILL KEEP AN EYE ON MODEL TRENDS AND ADJUST AS NECESSARY. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE REQUIRED THIS WEEKEND. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ UPDATE/AVIATION...WOLCOTT SHORT TERM........ADAIR LONG TERM.........PADDOCK FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1025 AM PDT FRI OCT 16 2015 .SYNOPSIS...BACK TO BACK STORM SYSTEMS WILL BRING THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS AT TIMES TO THE AREA THROUGH MONDAY EVENING. ANY HEAVIER RAINFALL AMOUNTS COULD RESULT IN FLASH FLOODING. OTHERWISE EXPECT EXTENSIVE CLOUD COVER IN MOST AREAS THROUGH MONDAY. DRIER WEATHER WILL RETURN AREA-WIDE FOR TUESDAY. HIGH TEMPERATURES WILL BE NEAR TO JUST SLIGHTLY ABOVE NORMAL THROUGH THE MIDDLE OF NEXT WEEK. && .UPDATE...A BROAD AREA OF SHOWERS WITH ISOLATED EMBEDDED THUNDERSTORMS WAS OVER NORTHEAST SAN BERNARDINO...EASTERN INYO AND CENTRAL SOUTHERN NYE COUNTIES THIS MORNING. BANDS OF LIGHT SHOWERS HAVE BEEN MOVING ACROSS CLARK COUNTY AND MOHAVE COUNTIES. THE LATEST HIGH RES MODELS INDICATE THE BEST FOCUS FOR PRECIPITATION WILL BE INYO...CENTRAL/SOUTHERN NYE AND ESMERALDA COUNTIES THROUGH THE AFTERNOON. HOWEVER...WE SHOULD STILL SOME BANDS OF LIGHT SHOWERS AND AND POSSIBLY A FEW THUNDERSTORMS OVER THE REST OF SOUTHERN NEVADA... NORTHWEST ARIZONA AND SAN BERNARDINO COUNTY CALIFORNIA. AS THE LOW OVER CENTRAL CALIFORNIA BEGINS TO LIFT TO THE NORTHEAST TONIGHT... ADDITIONAL FORCING SHOULD LEAD TO INCREASING COVERAGE OF SHOWERS ACROSS SOUTHERN NEVADA AND NORTHWEST ARIZONA LATE TONIGHT THROUGH SATURDAY MORNING. THIS TREND WAS ALREADY INDICATED IN THE POP GRIDS...BUT SLIGHT UPWARD ADJUSTMENTS WERE MADE TO INCLUDE NORTHEAST CLARK COUNTY INTO THE LIKELY CATEGORY SATURDAY MORNING. && .AVIATION...FOR MCCARRAN...SCATTERED LIGHT SHOWERS ARE POSSIBLE THROUGH THIS EVENING. CIGS EXPECTED TO REMAIN ABOVE 6K FEET. SHOWERS...SOME WITH MODERATE TO HEAVY RAIN ALONG WITH AN ISOLATED THUNDERSTORM WILL BE POSSIBLE AFTERNOON MIDNIGHT AND THROUGH MUCH OF SATURDAY MORNING. CIGS BETWEEN 12 AND 18Z WILL LOWER TO BETWEEN 3-5K FEET. WINDS ARE EXPECTED TO TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 8 KTS OR LESS BUT WILL GUST TO AROUND 20-25 KTS IN THE VICINITY OF STORMS. THE CHANCE FOR SHRA/TSRA WILL CONTINUE THROUGH MONDAY WITH CIGS/VSBY REDUCED TO MVFR OR LOWER AS WELL AS MOUNTAIN OBSCURATIONS POSSIBLE. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...SHRA/TSRA WILL AGAIN BE POSSIBLE THROUGH TONIGHT WITH THE BEST CHANCES ACROSS INYO, NORTHERN SAN BERNARDINO, CENTRAL AND SOUTHERN NYE, WESTERN CLARK AND CENTRAL MOHAVE COUNTIES THROUGH TONIGHT. SHOWERS AND THUNDERSTORMS WILL BE FAVORED OVER CLARK...LINCOLN AND MOHAVE COUNTIES ON SATURDAY. CIGS WILL MAINLY BE 6K-10K FEET IN AND NEAR SHRA/TSRA OTHERWISE 10K-14K FEET. VSBY MAY BE REDUCED TO MVFR OR LOWER WITH GUSTY AND ERRATIC WINDS POSSIBLE IN AND NEAR ANY SHRA/TSRA. OTHERWISE EXPECT WINDS TO TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 10 KTS OR LESS. MOUNTAIN OBSCURATIONS ARE POSSIBLE. THE CHANCE FOR SHRA/TSRA WILL CONTINUE THROUGH MONDAY WITH CIGS/VSBY REDUCED TO MVFR OR LOWER AS WELL AS MOUNTAIN OBSCURATIONS POSSIBLE. && .PREV DISCUSSION... 323 AM PDT FRI OCT 16 2015 .SHORT TERM...TODAY THROUGH SUNDAY NIGHT. BACK TO BACK STORM SYSTEMS WILL MAKE THINGS INTERESTING WEATHER-WISE RIGHT THROUGH THE WEEKEND. ONE THING TO KEEP IN MIND IF YOU HAVE PLANS TODAY THROUGH THIS WEEKEND IS THAT IT WILL NOT RAIN AT ALL TIMES BUT SPECIFIC TIMING OF WHEN IT WILL RAIN AND WILL BE DRY IS VERY TOUGH MORE THAN A FEW HOURS OUT IN THIS SORT OF PATTERN. SO, PLEASE KEEP UPDATED WITH THE WEATHER AS CONDITIONS CAN CHANGE RAPIDLY. AN MID/UPPER LEVEL LOW WAS LOCATED ON WATER VAPOR OVER SAN LUIS OBISPO COUNTY, CALIFORNIA EARLY THIS MORNING. MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY THOUGH WAS WELL TO THE EAST OF THE LOW CENTER EXTENDING FROM DEATH VALLEY NATIONAL PARK SOUTHEAST TOWARD IRON MOUNTAIN, CALIFORNIA. ACTIVITY WITHIN THIS BAND WAS MOVING NORTH AND MOST OF IT WAS LIGHT WITH ONLY EMBEDDED POCKETS OF MODERATE TO HEAVY RAIN AND A FEW THUNDERSTORMS. THE LATEST LOCAL ARW AND NMM MODELS AS WELL AS THE HRRR AND 00Z OPERATIONAL WRF, ECMWF AND GFS BASICALLY KEEP MOST OF THEIR QPF THROUGH LATE THIS MORNING OVER THESE SAME AREAS AND ONLY MOVE IT GRADUALLY FURTHER EAST THIS AFTERNOON. THIS POPS WERE TWEAKED UP FOR THESE AREAS. ONCE AGAIN IT APPEARS ACTIVITY IN LAS VEGAS TODAY WILL MAINLY BE ON THE LIGHT SIDE THROUGH THIS AFTERNOON. SPEED AND DIRECTIONAL SHEAR REMAIN FAVORABLE TO AID IN THE DEVELOPMENT OF A FEW STRONGER STORMS AND POSSIBLY EVEN SEVERE STORMS WITH HAIL AND GUSTY WINDS THE MAIN THREATS. A FLASH FLOOD WATCH IS CURRENTLY OUT FOR MUCH OF THE AREA. PARTS OF SAN BERNARDINO COUNTY (THE NW AND MORONGO BASIN) WILL SEE IT EXPIRE AT 8 PM THIS EVENING AS THE THREAT FOR STORMS STARTS TO DECREASE IN THESE AREAS THEN. THIS WILL BE A LOCALIZED THREAT THAT EXISTS MAINLY IN ANY STRONGER STORMS THAT CAN QUICKLY UNLOAD OR AREAS THAT SEE TRAINING STORMS. HIGH TEMPS WERE BUMPED UP A FEW DEGREES BASED ON THE LATEST MODEL GUIDANCE AND GIVEN THE WARM START TO THE DAY ALREADY. AS WE MOVE INTO TONIGHT THE AFOREMENTIONED LOW STARTS TO GET CAUGHT UP IN A BROADER MID/UPPER LEVEL TROUGH AND THE LOW STARTS TO GET STRETCHED OUT INTO AN OPEN WAVE AND BECOME AN ELONGATED PIECE OF ENERGY THAT MOVES SLOWLY NORTHEAST. WE MAY SEE OUR BEST CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE LAS VEGAS VALLEY LATER TONIGHT INTO SATURDAY MORNING AS THIS ENERGY MOVES RIGHT OVER US AND LARGER SCALE FORCING IS GREATER. BEHIND THIS FIRST SYSTEM DRIER AIR WILL WORK IN AND BRING AN END TO SHOWERS AND THUNDERSTORMS IN THE SOUTHWEST PART OF THE AREA. HOWEVER, CLOUDS WILL NOT CLEAR OUT ENTIRELY IN THESE SPOTS. THERE SHOULD BE SOME SORT OF BREAK IN BETWEEN THE TWO SYSTEMS THOUGH IT MAY NOT BE ALL THAT WELL DEFINED OR LAST LONG FURTHER EAST AND NORTH OF LAS VEGAS. HOWEVER, THE NEXT SYSTEM IS SLATED TO DROP SOUTH INTO NORCAL LATE SATURDAY AND SWING SOUTH ACROSS OUR AREA SUNDAY INTO SUNDAY NIGHT. THERE ARE A FEW GOOD SIGNS POINTING TO A DECENT POTENTIAL FOR PRECIP WITH THIS SYSTEM IN SOUTHERN NEVADA AND NORTHWEST ARIZONA. LOTS OF VORTICITY IS SHOWN TO WORK THROUGH THE BASE OF THE TROUGH AND A 50 KT+ JET STREAK AT 250 MB MOVES OVERHEAD. BOTH THE OPERATIONAL GFS AND ECMWF CONTINUE TO SHOW SOME HEAVIER QPF AMOUNTS WITH A BAND WORKING NORTHEAST OF THE TROUGH AXIS LATE SATURDAY NIGHT INTO SUNDAY AFTERNOON IN SOUTHERN NEVADA AND NORTHWEST ARIZONA. AS A RESULT, THE THOUGHT IS THIS MAY BE A BETTER CHANCE FOR FLASH FLOODING THAN WITH WHAT WE SEE TODAY OR SATURDAY AND THUS THE FLASH FLOOD WATCH KEEPS ON GOING THROUGH 8 PM SUNDAY. TEMPS WILL BE TRICKY AS THICKER CLOUD COVER AND PRECIP COULD HOLD DOWN READINGS EVEN MORE THAN WHAT IS FORECAST. POINTS TO STRESS... + ROADS WILL BE SLICK. SLOW DOWN AND PLAN AHEAD FOR TRAVEL. + FLASH FLOODING IS POSSIBLE IN ANY STRONGER STORMS OR TRAINING ACTIVITY. RAINFALL TOTALS COULD QUICKLY EXCEED AN INCH IN AN HOUR OR LESS. + PRECIP AMOUNTS WILL VARY WITH RAINFALL TOTALS OF A TENTH TO A HALF OF AN INCH THROUGH SATURDAY WITH LOCALIZED AMOUNTS OVER AN INCH. + SNOW LEVELS WILL REMAIN ABOVE 11,000 FEET WITH A FEW INCHES POSSIBLE. + ANOTHER THIRD TO THREE-QUARTERS OF AN INCH IS POSSIBLE SATURDAY NIGHT INTO MONDAY WITH THE NEXT SYSTEM. THE HIGHEST AMOUNTS WILL BE IN SOUTHERN NEVADA AND NORTHWEST ARIZONA. LOCALIZED TOTALS AGAIN COULD EXCEED AN INCH. + HAIL AND WIND GUSTS OVER 45 MPH ARE POSSIBLE IN ANY STRONGER THUNDERSTORMS. .LONG TERM...MONDAY THROUGH FRIDAY. DETERMINISTIC RUNS OF THE 00Z GFS/ECMWF ALONG WITH THE GFS ENSEMBLES NOW DEPICTING ADDITIONAL SHORTWAVE ENERGY MOVING DOWN BACKSIDE OF TROUGH WHICH WILL SLOW ITS EASTWARD PROGRESSION EARLY NEXT WEEK. IN FACT, THE ECMWF ALONG WITH NUMEROUS GFS ENSEMBLE MEMBERS DEVELOP A CLOSED LOW OVER ARIZONA WEDNESDAY. INTRODUCED A SLIGHT CHANCE OF PRECIPITATION TO MOHAVE COUNTY TUESDAY. LEFT WEDNESDAY DRY FOR NOW BUT DEPENDING ON UPPER LOW PLACEMENT WE COULD SEE A FEW SHOWERS IN SOUTHEAST MOHAVE COUNTY. A TROUGH APPROACHING THE PACIFIC NORTHWEST COAST WILL KICK THE LOW EASTWARD OUT OF ARIZONA THURSDAY. THERE ARE SIGNIFICANT DIFFERENCES BETWEEN THE DETERMINISTIC GFS/ECMWF ON FRIDAY. THE ECMWF DEVELOPS ANOTHER SIGNIFICANT TROUGH ACROSS CALIFORNIA/NEVADA FRIDAY-SATURDAY, WHILE THE GFS IS NOT AS AMPLIFIED. THE ECMWF SOLUTION WOULD TURN OUT WETTER AND COOLER WHILE THE GFS WOULD BE DRY AND WINDY. DUE TO THE UNCERTAINTY LEFT LATE NEXT WEEK ALONE. && .CLIMATE...RECORD HIGH MINIMUM TEMPERATURES ARE ALSO POSSIBLE FOR LAS VEGAS TODAY AND SATURDAY. DATE VALUE/YEAR ----------------------------- 10/16 66/2010* 10/17 67/1991 * TIE FROM PREVIOUS YEARS. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE REQUIRED THROUGH MONDAY. && $$ UPDATE...ADAIR AVIATION...CZYZYK SHORT TERM...STACHELSKI LONG TERM...PIERCE FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
323 AM PDT FRI OCT 16 2015 .SYNOPSIS...BACK TO BACK STORM SYSTEMS WILL BRING THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS AT TIMES TO THE AREA THROUGH MONDAY EVENING. ANY HEAVIER RAINFALL AMOUNTS COULD RESULT IN FLASH FLOODING. OTHERWISE EXPECT EXTENSIVE CLOUD COVER IN MOST AREAS THROUGH MONDAY. DRIER WEATHER WILL RETURN AREA-WIDE FOR TUESDAY. HIGH TEMPERATURES WILL BE NEAR TO JUST SLIGHTLY ABOVE NORMAL THROUGH THE MIDDLE OF NEXT WEEK. && .SHORT TERM...TODAY THROUGH SUNDAY NIGHT. BACK TO BACK STORM SYSTEMS WILL MAKE THINGS INTERESTING WEATHER-WISE RIGHT THROUGH THE WEEKEND. ONE THING TO KEEP IN MIND IF YOU HAVE PLANS TODAY THROUGH THIS WEEKEND IS THAT IT WILL NOT RAIN AT ALL TIMES BUT SPECIFIC TIMING OF WHEN IT WILL RAIN AND WILL BE DRY IS VERY TOUGH MORE THAN A FEW HOURS OUT IN THIS SORT OF PATTERN. SO, PLEASE KEEP UPDATED WITH THE WEATHER AS CONDITIONS CAN CHANGE RAPIDLY. AN MID/UPPER LEVEL LOW WAS LOCATED ON WATER VAPOR OVER SAN LUIS OBISPO COUNTY, CALIFORNIA EARLY THIS MORNING. MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY THOUGH WAS WELL TO THE EAST OF THE LOW CENTER EXTENDING FROM DEATH VALLEY NATIONAL PARK SOUTHEAST TOWARD IRON MOUNTAIN, CALIFORNIA. ACTIVITY WITHIN THIS BAND WAS MOVING NORTH AND MOST OF IT WAS LIGHT WITH ONLY EMBEDDED POCKETS OF MODERATE TO HEAVY RAIN AND A FEW THUNDERSTORMS. THE LATEST LOCAL ARW AND NMM MODELS AS WELL AS THE HRRR AND 00Z OPERATIONAL WRF, ECMWF AND GFS BASICALLY KEEP MOST OF THEIR QPF THROUGH LATE THIS MORNING OVER THESE SAME AREAS AND ONLY MOVE IT GRADUALLY FURTHER EAST THIS AFTERNOON. THIS POPS WERE TWEAKED UP FOR THESE AREAS. ONCE AGAIN IT APPEARS ACTIVITY IN LAS VEGAS TODAY WILL MAINLY BE ON THE LIGHT SIDE THROUGH THIS AFTERNOON. SPEED AND DIRECTIONAL SHEAR REMAIN FAVORABLE TO AID IN THE DEVELOPMENT OF A FEW STRONGER STORMS AND POSSIBLY EVEN SEVERE STORMS WITH HAIL AND GUSTY WINDS THE MAIN THREATS. A FLASH FLOOD WATCH IS CURRENTLY OUT FOR MUCH OF THE AREA. PARTS OF SAN BERNARDINO COUNTY (THE NW AND MORONGO BASIN) WILL SEE IT EXPIRE AT 8 PM THIS EVENING AS THE THREAT FOR STORMS STARTS TO DECREASE IN THESE AREAS THEN. THIS WILL BE A LOCALIZED THREAT THAT EXISTS MAINLY IN ANY STRONGER STORMS THAT CAN QUICKLY UNLOAD OR AREAS THAT SEE TRAINING STORMS. HIGH TEMPS WERE BUMPED UP A FEW DEGREES BASED ON THE LATEST MODEL GUIDANCE AND GIVEN THE WARM START TO THE DAY ALREADY. AS WE MOVE INTO TONIGHT THE AFOREMENTIONED LOW STARTS TO GET CAUGHT UP IN A BROADER MID/UPPER LEVEL TROUGH AND THE LOW STARTS TO GET STRETCHED OUT INTO AN OPEN WAVE AND BECOME AN ELONGATED PIECE OF ENERGY THAT MOVES SLOWLY NORTHEAST. WE MAY SEE OUR BEST CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE LAS VEGAS VALLEY LATER TONIGHT INTO SATURDAY MORNING AS THIS ENERGY MOVES RIGHT OVER US AND LARGER SCALE FORCING IS GREATER. BEHIND THIS FIRST SYSTEM DRIER AIR WILL WORK IN AND BRING AN END TO SHOWERS AND THUNDERSTORMS IN THE SOUTHWEST PART OF THE AREA. HOWEVER, CLOUDS WILL NOT CLEAR OUT ENTIRELY IN THESE SPOTS. THERE SHOULD BE SOME SORT OF BREAK IN BETWEEN THE TWO SYSTEMS THOUGH IT MAY NOT BE ALL THAT WELL DEFINED OR LAST LONG FURTHER EAST AND NORTH OF LAS VEGAS. HOWEVER, THE NEXT SYSTEM IS SLATED TO DROP SOUTH INTO NORCAL LATE SATURDAY AND SWING SOUTH ACROSS OUR AREA SUNDAY INTO SUNDAY NIGHT. THERE ARE A FEW GOOD SIGNS POINTING TO A DECENT POTENTIAL FOR PRECIP WITH THIS SYSTEM IN SOUTHERN NEVADA AND NORTHWEST ARIZONA. LOTS OF VORTICITY IS SHOWN TO WORK THROUGH THE BASE OF THE TROUGH AND A 50 KT+ JET STREAK AT 250 MB MOVES OVERHEAD. BOTH THE OPERATIONAL GFS AND ECMWF CONTINUE TO SHOW SOME HEAVIER QPF AMOUNTS WITH A BAND WORKING NORTHEAST OF THE TROUGH AXIS LATE SATURDAY NIGHT INTO SUNDAY AFTERNOON IN SOUTHERN NEVADA AND NORTHWEST ARIZONA. AS A RESULT, THE THOUGHT IS THIS MAY BE A BETTER CHANCE FOR FLASH FLOODING THAN WITH WHAT WE SEE TODAY OR SATURDAY AND THUS THE FLASH FLOOD WATCH KEEPS ON GOING THROUGH 8 PM SUNDAY. TEMPS WILL BE TRICKY AS THICKER CLOUD COVER AND PRECIP COULD HOLD DOWN READINGS EVEN MORE THAN WHAT IS FORECAST. POINTS TO STRESS... + ROADS WILL BE SLICK. SLOW DOWN AND PLAN AHEAD FOR TRAVEL. + FLASH FLOODING IS POSSIBLE IN ANY STRONGER STORMS OR TRAINING ACTIVITY. RAINFALL TOTALS COULD QUICKLY EXCEED AN INCH IN AN HOUR OR LESS. + PRECIP AMOUNTS WILL VARY WITH RAINFALL TOTALS OF A TENTH TO A HALF OF AN INCH THROUGH SATURDAY WITH LOCALIZED AMOUNTS OVER AN INCH. + SNOW LEVELS WILL REMAIN ABOVE 11,000 FEET WITH A FEW INCHES POSSIBLE. + ANOTHER THIRD TO THREE-QUARTERS OF AN INCH IS POSSIBLE SATURDAY NIGHT INTO MONDAY WITH THE NEXT SYSTEM. THE HIGHEST AMOUNTS WILL BE IN SOUTHERN NEVADA AND NORTHWEST ARIZONA. LOCALIZED TOTALS AGAIN COULD EXCEED AN INCH. + HAIL AND WIND GUSTS OVER 45 MPH ARE POSSIBLE IN ANY STRONGER THUNDERSTORMS. .LONG TERM...MONDAY THROUGH FRIDAY. DETERMINISTIC RUNS OF THE 00Z GFS/ECMWF ALONG WITH THE GFS ENSEMBLES NOW DEPICTING ADDITIONAL SHORTWAVE ENERGY MOVING DOWN BACKSIDE OF TROUGH WHICH WILL SLOW ITS EASTWARD PROGRESSION EARLY NEXT WEEK. IN FACT, THE ECMWF ALONG WITH NUMEROUS GFS ENSEMBLE MEMBERS DEVELOP A CLOSED LOW OVER ARIZONA WEDNESDAY. INTRODUCED A SLIGHT CHANCE OF PRECIPITATION TO MOHAVE COUNTY TUESDAY. LEFT WEDNESDAY DRY FOR NOW BUT DEPENDING ON UPPER LOW PLACEMENT WE COULD SEE A FEW SHOWERS IN SOUTHEAST MOHAVE COUNTY. A TROUGH APPROACHING THE PACIFIC NORTHWEST COAST WILL KICK THE LOW EASTWARD OUT OF ARIZONA THURSDAY. THERE ARE SIGNIFICANT DIFFERENCES BETWEEN THE DETERMINISTIC GFS/ECMWF ON FRIDAY. THE ECMWF DEVELOPS ANOTHER SIGNIFICANT TROUGH ACROSS CALIFORNIA/NEVADA FRIDAY-SATURDAY, WHILE THE GFS IS NOT AS AMPLIFIED. THE ECMWF SOLUTION WOULD TURN OUT WETTER AND COOLER WHILE THE GFS WOULD BE DRY AND WINDY. DUE TO THE UNCERTAINTY LEFT LATE NEXT WEEK ALONE. && .AVIATION...FOR MCCARRAN...SCATTERED SHOWERS ARE EXPECTED TO CONTINUE THROUGH TONIGHT. MOST OF THE SHOWERS ARE EXPECTED TO REMAIN LIGHT...BUT THERE WILL BE A FEW HEAVIER SHOWERS ALONG WITH AN ISOLATED THUNDERSTORM THAT WILL DROP CIGS TO AROUND 5-6K FEET AND POTENTIALLY LOWER VSBYS TO 5SM. WINDS ARE EXPECTED TO TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 8 KTS OR LESS BUT WILL GUST TO AROUND 20-25 KTS IN THE VICINITY OF STORMS. THE CHANCE FOR SHRA/TSRA WILL CONTINUE THROUGH MONDAY WITH CIGS/VSBY REDUCED TO MVFR OR LOWER AS WELL AS MOUNTAIN OBSCURATIONS POSSIBLE. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...SHRA/TSRA WILL AGAIN BE POSSIBLE TODAY AND TONIGHT WITH THE BEST CHANCES ACROSS INYO, NORTHERN SAN BERNARDINO, CENTRAL AND SOUTHERN NYE, WESTERN CLARK AND CENTRAL MOHAVE COUNTIES. CIGS WILL MAINLY BE 6K-10K FEET IN AND NEAR SHRA/TSRA OTHERWISE 10K-14K FEET. VSBY MAY BE REDUCED TO MVFR OR LOWER WITH GUSTY AND ERRATIC WINDS POSSIBLE IN AND NEAR ANY SHRA/TSRA. OTHERWISE EXPECT WINDS TO TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 10 KTS OR LESS. MOUNTAIN OBSCURATIONS ARE POSSIBLE. THE CHANCE FOR SHRA/TSRA WILL CONTINUE THROUGH MONDAY WITH CIGS/VSBY REDUCED TO MVFR OR LOWER AS WELL AS MOUNTAIN OBSCURATIONS POSSIBLE. && .CLIMATE...RECORD HIGH MINIMUM TEMPERATURES ARE ALSO POSSIBLE FOR LAS VEGAS TODAY AND SATURDAY. DATE VALUE/YEAR ----------------------------- 10/16 66/2010* 10/17 67/1991 * TIE FROM PREVIOUS YEARS. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE REQUIRED THROUGH MONDAY. && $$ SHORT TERM/AVIATION...STACHELSKI LONG TERM...PIERCE FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
142 AM EDT FRI OCT 16 2015 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS TO NY AND PA FRIDAY MORNING. A SECONDARY SHOT OF COLD AIR ON FRIDAY NIGHT WILL BRING A BIG DROP IN TEMPERATURES, AND WILL KEEP OUR WEATHER UNSETTLED THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 10 PM UPDATE... AN AREA OF RAIN WITH GUSTY WINDS CONTINUES TO MARCH ACROSS OUR AREA. THE FRONT ITSELF IS NOW OVER WESTERN NY. WE HAVE SEEN TWO IMPRESSIVE SQUALL LINES COMING OFF LAKE ERIE BUT THESE HAVE BOTH FALLEN APART. IT APPEARS THE STRONGEST WINDS FOR OUR AREA WILL BE ON THE LEADING EDGE OF THE RAIN NOW MOVING INTO ELMIRA, CORTLAND AND ITHACA. THIS AREA OF RAIN PRODUCED A GUST TO 40 MPH AT SYRACUSE AND 42 MPH AT FINGER LAKES REGIONAL AIRPORT (JUST SOUTH OF SENECA FALLS). I AM STILL EXPECTING THE MAGNITUDE OF THE WIND TO DIE OFF WITH EACH PASSING HOUR. SEE PREVIOUS AFD BELOW FOR WIND GUSTS THROUGH THE REST OF TONIGHT. WITH THE HRRR AND LATEST HI RESOLUTION MODELS STILL DOING WELL, INCREASE POPS FOR THE REST OF NY TO 90%+ ALONG WITH THE NORTHERN TIER OF PA, WITH 60%+ DOWN IN THE WYOMING VALLEY OF PA. 8 PM UPDATE... MADE BIG CHANGES TO OUR FORECAST, INCREASING CHANCES FOR RAIN TO 90%+ ACROSS NY STATE AND ABOVE 60% IN PA. A COLD FRONT IS NOW JUST CROSSING LAKE ERIE AND WESTERN LAKE ONTARIO. AHEAD AN AREA OF SHOWERS IS NOW MOVING INTO OUR AREA. GUSTY WINDS LIKELY WITH ANY SHOWERS THROUGH THIS EVENING. WHILE THE STRONGEST WINDS WILL LIKELY REMAIN OVER WESTERN NY, GUSTS IN THE 30 TO 40 MPH RANGE ARE VERY LIKELY ESPECIALLY FROM THE FINGER LAKES THROUGH CENTRAL NY, THROUGH MIDNIGHT. BASED ON LIGHTNING OVER WESTERN NY AND THE SAME CONVECTIVE ELEMENTS SHOWING UP ON HIGHER RESOLUTION MODELS INTO OUR AREA, ADDED CHANCE THUNDER TO THE FORECAST FOR THE AREAS JUST MENTIONED. LIFTED INDICES IN THESE AREAS ARE AROUND 0, OR ABOUT WHAT THEY ARE NOW IN BUFFALO WHERE THEY ARE SEEING SOME LIGHTNING. FARTHER SOUTH AND EAST RAIN WILL MAKE IT TOWARD THE SOUTHERN TIER AND NORTHERN PA LATER TONIGHT. GUSTY WINDS ARE STILL LIKELY ALONG THE NY/PA BORDER BUT THE MAGNITUDE WILL REALLY DROP OFF INTO NEPA, WHICH IS FARTHER AWAY FROM THE STRONGEST UPPER LEVEL SUPPORT. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... LAKE EFFECT RAIN SHOWERS REMAIN POSSIBLE ON FRIDAY DUE TO ABOVE NORMAL LAKE TO 850MB LAPSE RATES. HOWEVER WITH STRONG DOWNWARD MOTION BEHIND EXITING ENERGY, IT APPEARS THE SHOWERS WILL BE MINIMAL AND MAINLY EAST/DOWNWIND OF LAKE ONTARIO. THE SECONDARY SHOT OF COLD AIR WITH THE FRONT FRIDAY NIGHT LOOKS TO BE THE MOST IMPRESSIVE COLD POOL OF THE SEASON. 850MB TEMPS FALL TO -4C TO -6C LATE FRIDAY NIGHT, AND SOME OF THE RAIN SHOWERS MAY CHANGE OVER TO WET SNOW SHOWERS DURING THE EARLY MORNING HOURS SATURDAY. AS THE LAKE FLOW FALLS APART SATURDAY NIGHT INTO EARLY SUNDAY, TEMPERATURES ARE EXPECTED TO FALL INTO THE MID TO UPPER 20S, INCLUDING OVER THE FINGER LAKES AND LACKAWANNA/LUZERNE COUNTIES WHERE THE GROWING SEASON REMAINS ACTIVE. A WIDESPREAD FROST/FREEZE IS POSSIBLE. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... 4 PM THURSDAY UPDATE... A DEEP EASTERN CANADIAN/NORTHEASTERN U.S. TROUGH SUNDAY NIGHT INTO MONDAY, WILL LIFT OUT WITH TIME THEREAFTER, AS HEIGHTS ALOFT SIGNIFICANTLY BUILD NEXT WEEK OVER THE EASTERN U.S. LINGERING RAIN/SNOW SHOWERS INTO EARLY MONDAY, MAINLY OVER CENTRAL NY, WILL DISSIPATE DURING THE DAY, WITH SURFACE RIDGING COMING IN FROM THE WEST. OTHER THAN PERHAPS A FEW SHOWERS IN OUR FAR NORTHERN ZONES TUESDAY-WEDNESDAY, CLOSER TO A WARM FRONTAL BOUNDARY, IT WILL BE DRY AND MILDER, WITH HIGHS IN THE 50S-LOWER 60S. THURSDAY WILL REMAIN MILD, BUT OUR CHANCES FOR SHOWERS MAY INCREASE BY LATER IN THE DAY, AS A COLD FRONT SLOWLY APPROACHES FROM THE NORTHWEST. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... A COLD FRONT IS SLOWLY MOVING ACROSS NY AND PA THIS MORNING. AHEAD OF THE FRONT... WINDS ARE STILL SOUTHWESTERLY AROUND 5 TO 10 KNOTS... AND BEHIND THE FRONT WINDS ARE WESTERLY AROUND 12 KNOTS. THIS FRONT IS PUSHING THROUGH A LINE OF LIGHT RAIN SHOWERS... AND FOR THE MOST PART MOST OF THE ACTIVITY IS VFR. THERE WILL BE A BRIEF PERIOD EARLY THIS MORNING WHERE FLIGHT CONDITIONS ARE EXPECTED TO BE MVFR. CONDITIONS ARE EXPECTED TO IMPROVE BY MID 15Z. BEHIND THE FROPA IT LOOKS LIKE A GOOD SET UP FOR SOME LAKE EFFECT SHOWERS. THE BEST CHANCE FOR THIS WILL BE OVER KRME AND KSYR... THUS INCLUDED SHRA IN THE TAFS. THE REMAINING SITES WILL HAVE A CHANCE TO SEE A RAIN SHOWER FRIDAY EVENING BUT CONFIDENCE IS TO LOW ATTM TO PLACE IN TAFS. .OUTLOOK... SAT-SUN...OCCASIONAL LIGHT SHOWERS/MVFR CEILINGS ARE ANTICIPATED, PARTICULARLY OVER CENTRAL NY, AS MULTIPLE DISTURBANCES TRACK ACROSS THE REGION. RAIN SHOWERS WILL LIKELY MIX WITH, OR EVEN CHANGE TO SNOW SHOWERS. MON-TUE...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJP NEAR TERM...HEDEN SHORT TERM...DJP LONG TERM...MLJ AVIATION...KAH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1015 PM EDT SAT OCT 17 2015 .SYNOPSIS... A STRONG BUT DRY COLD FRONT WILL MOVE THROUGH TONIGHT. HIGH PRESSURE WILL BUILD OVER THE AREA THIS WEEKEND THROUGH MUCH OF NEXT WEEK. THE NEXT FRONTAL SYSTEM WILL APPROACH THE REGION LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 10 PM SAT...MODELS IN EXCELLENT AGREEMENT ON NEXT SURGE OF CAA COMMENCING THIS EVENING AS DRY COLD FRONT DROPS THROUGH THE AREA FROM THE NORTH. UPSTREAM THICKNESSES ARE FALLING ACROSS THE INTERIOR CAROLINAS...WITH LOW LEVEL WINDS VEERING NORTH. USED A BLEND OF HIGH RES MODELS TO FCST WINDS OVERNIGHT...AND SHOULD SEE ENOUGH DRY/COLD ADVECTION AND LOW LEVEL MIXING TO PRECLUDE ANY FOG DEVELOPMENT. A WIDE RANGE OF LOWS EXPECTED...WITH UPR 30S INLAND TO LOW 50S OBX...WHERE WIND ADVECTING OVER THE RELATIVELY WARM WATERS WILL KEEP TEMPS UP HERE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AS OF 330 PM SAT...DEEP/COLD TROUGH AXIS PROGGED TO MOVE ACROSS EASTERN CONUS ON SUNDAY WITH SFC HIGH PRES BUILDING INTO THE OHIO VALLEY. LOW LEVEL THICKNESS VALS ON PAR WITH MOS GUID FORECASTING CHILLY MAX TEMPS IN THE UPR 50S TO NEAR 60...COOLEST NORTH. CONTINUED CAA AND NORTH WINDS WILL MAKE IT FEEL QUITE BRISK DESPITE FULL SUNSHINE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... AS OF 330 PM SAT...MINOR ADJUSTMENTS TO TEMPS DURING PERIOD. MODELS REMAIN IN GOOD AGREEMENT THAT RIDGING SFC AND ALOFT WILL CONTINUE THROUGH MID WEEK...FOLLOWED BY ANOTHER DRY COLD FRONTAL PASSAGE FRIDAY. MAIN SIGNIFICANT WX THREAT DURING PERIOD WILL BE PSBL FROST SUN NIGHT AND AGAIN MON NIGHT. MODEL GDNC CONTINUES TO INDICATE COLDEST TEMPS SUN NIGHT WTIH LOWS 33-36 DEGS FOR NORMALLY COLDER AREAS ALONG AND W OF HWY 17. COULD EVEN SEE SOME 32 DEG READINGS IN ISOLATED AREAS BUT NOT EXPECTED TO BE WDSPRD ENOUGH TO WARRANT FREEZE WATCH...BUT FROST ADVSY LIKELY TO BE ISSUED WITH NEXT FULL FCST PACKAGE AROUND 4 AM SUNDAY. GOOD RADIATIONAL COOLING CONDITIONS LIKELY AGAIN MON NIGHT WITH SFC HIGH CENTER OVER AREA RESULTING IN LIGHT WINDS ALL THE WAY TO COAST. MOS GDNC INDICATING LOWS MID TO UPR 30S FOR MOST INLAND AREAS...AND COULD SEE SCT FROST THREAT EVEN CLOSER TO COAST THAN ON SUN NIGHT. TEMPS WILL GRADUALLY MODERATE TUE-THU WITH RIDGING ALOFT WHILE SFC HIGH EXTENDS OVER AREA FROM OFFSHORE. LOWS WILL BE IN 40S AND 50S WITH HIGHS IN THE 70S. FRIDAY TO SATURDAY...12Z GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT WITH ANOTHER DRY COLD FRONT MOVING THROUGH EARLY FRIDAY FOLLOWED BY HIGH PRES RIDING IN FROM N FRI NIGHT AND SAT. TEMPS WILL DROP BACK INTO 40S FRI NIGHT WITH HIGHS IN 60S FOR SAT. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... SHORT TERM /THROUGH 18Z SUNDAY/... AS OF 10 PM SAT...PRED VFR EXPECTED THROUGH THE PERIOD WITH SUNNY SKIES...LIGHT N/NW WINDS 5-10KT. KMHX 88D VWP SHOWS 30 KNOTS AT 1 KFT SO WILL KEEP NON CONVECTIVE LLWS AT ALL TERMINALS. SHORT TERM MODELS SHOW WINDS DECREASING AFTER ABOUT 06Z SO WILL CARRY LLWS WORDING UNTIL THEN. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 330 PM SAT...HIGH CONFIDENCE OF VFR CONDITIONS WILL CONTINUE THROUGH THIS PERIOD AS HIGH PRESSURE DOMINATES THE REGION. && .MARINE... SHORT TERM /THROUGH SUNDAY... AS OF 10 PM SAT...STRONG COLD AIR ADVECTION WILL COMMENCE THIS EVENING WITH SCA HEADLINES ON TRACK TO BEGIN JUST PRIOR TO MIDNIGHT AS COLD FRONT DROPS SOUTH THROUGH THE MARINE ZONES. USED A BLEND OF HIGH RES MODELS INCLUDING THE HRRR TO FCST WINDS. WINDS INCRS TO SCA RANGE THIS EVENING AND WILL PEAK LATE TONIGHT IN THE 20-25 KT RANGE WITH SOME GUSTS TO 30 KT FOR ALL WATERS AND SOUNDS...EXCLUDING THE BAY...PAMLICO...AND NEUSE RIVERS...THOUGH OCNL GUSTS TO 25 KT ARE CERTAINLY POSSIBLE PER HRRR FCST. SEAS WILL BUILD DRAMATICALLY TONIGHT AND PEAK IN THE 5 TO 8 FT RANGE...HIGHEST OUTER CENTRAL AND NRN WATERS. WINDS WILL COME DOWN A BIT TO 10-20 KT ON SUNDAY BUT SEAS WILL REMAIN ELEVATED ABOVE 6 FT. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 330 PM SAT...MODELS REMAIN IN GOOD AGREEMENT WITH FINAL CAA SURGE PRODUCING N-NE WINDS 20-25 KT OVER MOST OF WATERS SUN NIGHT INTO MONDAY...AND EXTENDED SCA HEADLINES ACCORDINGLY. WINDS DIMINISH QUICKLY LATE MON AND MON NIGHT. SFC RIDGE AXIS EXTENDING W TO E ACROSS WATERS WILL LEAD TO LIGHT AND SOMEWHAT VRBL CONDITIONS TUE-THU. LATEST WAVE GDNC SUPPORTS PREVIOUS FCST WTIH SEAS BUILDING TO 5-7 FT SUN NIGHT...THEN SUBSIDING ON MONDAY WITH DIMINISHING WINDS. HEIGHTS MAINLY 2-3 FT TUE-THU. && .CLIMATE... RECORD MIN TEMPS FOR 10/19 (MONDAY) LOCATION TEMP/YEAR NEW BERN 33/1948 (KEWN ASOS) CAPE HATTERAS 39/1978 (KHSE ASOS) GREENVILLE 33/1970 (COOP - NOT KPGV AWOS) MOREHEAD CITY 37/1967 (COOP - NOT KMRH ASOS) KINSTON 30/1973 (COOP - NOT KISO AWOS) JACKSONVILLE 36/1992 (KNCA AWOS) && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ135. SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ130-131. SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ150-152-154. SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ156-158. && $$ SYNOPSIS...TL NEAR TERM...HSA/TL SHORT TERM...TL LONG TERM...JBM AVIATION...HSA/TL/JBM MARINE...HSA/TL/JBM CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
111 PM EDT FRI OCT 16 2015 .SYNOPSIS... A COLD FRONT WITH LIMITED MOISTURE WILL MOVE ACROSS THE REGION LATE TODAY, FOLLOWED BY HIGH PRESSURE THAT WILL BUILD OVER THE AREA THIS WEEKEND THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THIS AFTERNOON/... AS OF 111 PM FRI...SFC COLD FRONT ENTERING NORTHERN PORTIONS OF NC EARLY THIS AFTERNOON. MID CLOUD COVER EXTENDS ALONG AND BEHIND THE SFC COLD FRONT AS 700MB FGEN EVIDENT PER MODEL X SECTIONS. SOME LIGHT RAIN AND SPRINKLES DOT THE AREA NORTH OF THE FA...THOUGH THESE ARE NOT AMOUNTING TO MUCH PER MODEL SNDGS INDICATING DECENT LOW LEVEL DRY AIR IN PLACE. WILL LEAVE MENTION OF -RA OUT OF FCST REST OF THE AFTERNOON AS CLOUDS ARE ERODING AS THEY ENTER THE FA FROM THE NORTHWEST. WILL LEAVE IN MENTION OF SPRINKLES THIS EVENING ACROSS THE NE ZONES. TEMPS ON TRACK IN THE 75-80 DEGREE RANGE FOR HIGHS. PREVIOUS DISCUSSION...AS OF 10 AM FRI...HAVE ADJUSTED CLOUD COVER BASED ON CURRENT SATELLITE TRENDS. TOA TOOL INDICATES AREA OF MID CLOUD DECK ARRIVING IN COASTAL PLAIN COUNTIES AND NORTHERN TIER BY AROUND NOON AND SPREADING SOUTH AND EASTWARD THROUGH THE AFTERNOON. HIGH TEMPS STILL ON TRACK TO REACH MID 70S NORTH AND THEN SLOWLY FALLING THROUGH THE AFTERNOON WITH COLD FROPA...AND NEAR 80 ELSEWHERE WITH SW WINDS AND LOW LEVEL THICKNESSES SUPPORTING ABOVE CLIMO READINGS. SLIGHT ADJUSTMENT TO WINDS BASED ON LATEST HRRR INDICATING SHARP VEERING FROM SW TO NW/N BEHIND THE FRONT LATE THIS AFTERNOON. && .SHORT TERM /TONIGHT/... AS OF 245 AM FRIDAY...THE UPPER TROUGH AXIS WILL REMAIN CENTERED OVER THE EASTERN CONUS TONIGHT WITH STRONG HIGH PRESSURE BUILDING ACROSS EASTERN NC FROM THE CENTRAL PLAINS/MIDWESTERN STATES. THE COLD FRONT WILL PUSH OFF THE NC COAST BETWEEN 03-06Z TONIGHT AND WILL KEEP ISOLATED SHOWERS IN FORECAST THROUGH 03Z. WINDS SHIFT NORTHERLY BEHIND THE FRONT LATE THIS EVENING INTO EARLY TONIGHT THOUGH REMAIN LESS THAN 10 MPH INLAND AND 10-15 MPH ALONG THE COAST. DRIER AIRMASS WILL SHIFT EAST OVER THE REGION LATE WITH LOW TEMPERATURES FALLING INTO THE MID 40S INLAND TO LOW 50S ALONG THE SOUTHERN COAST, WITH MID TO UPPER 50S ALONG THE OUTER BANKS. && .LONG TERM /SATURDAY THROUGH FRIDAY/... AS OF 240 AM FRI...NO SIGNIFICANT CHANGES DURING PERIOD AS MODELS REMAIN IN DECENT AGREEMENT WITH HIGH AND DRY CONDITIONS PERSISTING INTO MIDDLE OF NEXT WEEK. SAT THROUGH MONDAY NIGHT...EXPECT TEMPS TO BE BELOW NORMAL THIS PERIOD AS DEEP UPR TRF CROSSES WITH STRONG SFC HIGH BUILDING IN FROM THE NW. INIT CAA WILL LEAD TO HIGHS IN THE 65 TO 70 DGR RANGE SAT. STRONGER CAA KICKS IN SAT NIGHT AND SUNDAY WITH LOWS AROUND 40 INLAND SAT NIGHT AND MID/UPR 30S SUN NIGHT AND MON NIGHT. HIGHS BOTH SUN AND MON WILL BE IN THE UPR 50S TO LOWER 60S. THERE WILL LIKELY BE PATCHY FROST INLAND FROM THE COAST BOTH SUN NIGHT AND MON NIGHT. TUESDAY THROUGH THU...UPPER RIDGE BUILDS EAST AS SFC HIGH EVENTUALLY MOVES OFF THE COAST BRINGING SLOWLY MODERATING TEMPS AND CONTINUED DRY WEATHER INTO MID WEEK. HIGH TEMPS WILL RISE WELL INTO THE 60S TUE THEN BACK TO NEAR NORMAL LEVELS IN THE 70S ON WEDNESDAY AND THU. AS ONSHORE FLOW DEVELOPS THU SLIGHT CHC OF SHRA MAINLY OVER THE CSTL WTRS. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 12Z SATURDAY/... AS OF 111 PM FRIDAY...PREDOMINANT VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A WEAK COLD FRONT WITH LIMITED MOISTURE WILL CROSS EASTERN NC LATE THIS AFTERNOON INTO THIS EVENING RESULTING IN SOME MID/HIGH CLOUDS ACROSS EASTERN NC, BUT REMAINING VFR. WINDS JUST ALOFT WILL REMAIN NORTH TO NW EVEN THOUGH SFC WINDS BECOME CALM INHIBITING COVERAGE OF FOG/BR. STILL COULD SEE SOME LIGHT BR DEVELOP IN PRONE AREAS NEAR RIVERS/STREAMS. WINDS WILL BE LIGHT N/NW ON FRIDAY THOUGH REMAIN LIGHT 5-8 KT UNDER SUNNY SKIES. LONG TERM /SAT THROUGH TUESDAY/... AS OF 240 AM FRI...HIGH CONFIDENCE IN PROLONGED PERIOD OF VFR. HIGH PRES AND DRY AIR WILL DOMINATE WITH LITTLE IN THE WAY OF CLOUDS. SOME LOCAL STEAM FOG PSBL FOR SUN NIGHT AND MON NIGHT. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 111 PM FRI...LATEST OBS INDICATE SW WINDS 10-15 KT WITH OCNL 20 KT GUSTS AS SW GRADIENT INC AHEAD OF COLD FRONT. MEDIUM PERIOD SEAS STILL 1-2 FT ACROSS THE WATERS. THE COLD FRONT WILL CROSS THE WATERS LATE THIS AFTERNOON INTO THE EVENING, SHARPLY VEERING WINDS FROM SOUTHWEST MOST OF TODAY TO NORTHERLY ACROSS THE NORTHERN TIER OF WATERS BY LATE AFTERNOON, WITH FRONT QUICKLY MOVING THROUGH REMAINDER OF WATERS THROUGH EARLY EVENING, BUT REMAINING 15 KT OR LESS POST- FRONTAL. A FEW GUSTS INTO THE 20-24 KT RANGE WITH QUICK NORTHERLY SURGE THOUGH REMAINING BELOW SCA. LONG TERM /SAT THROUGH TUESDAY/... AS OF 240 AM FRI...N WINDS MAINLY 15 TO 20 KTS THRU SAT BEHIND COLD FRONT. SECONDARY SURGES OF CAA WILL FOLLOW SAT NIGHT AND SUN NIGHT RESULTING IN NE WINDS INCREASING TO 20-25 KT LATER SUN NIGHT INTO MON. WINDS WILL GRADUALLY DIMINISH N TO S ON TUESDAY WITH WEAKENING PRES GRADIENT. SEAS WILL BUILD TO 3-5 FT SAT...4-6 FT SUN AND MAY REACH 7 TO 8 FT OUTER CNTRL WTRS EARLY MON. SEAS WILL GRAD SUBSIDE TUE AS WINDS DIMINISH. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG NEAR TERM...DAG/TL SHORT TERM...DAG LONG TERM...RF/JBM AVIATION...RF/DAG/TL MARINE...RF/DAG/TL
AREA FORECAST DISCUSSION
NWS Tulsa OK
1143 PM CDT THU OCT 15 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. For the 6Z TAFS, Gusty northeasterly winds will affect all sites overnight in the wake of a passing cold front. Scattered showers and thunderstorms could temporarily affect Northeast Oklahoma and Northwest Arkansas sites for the first portion of the forecast period. VFR ceilings and visibilities are expected to prevail at all sites for the entire forecast period. && .PREV DISCUSSION... /ISSUED 919 PM CDT THU OCT 15 2015/ DISCUSSION... Cold front is making steady progress to the south this evening and will exit the area by midnight or shortly thereafter. A band of showers and thunderstorms has developed behind the front near the Oklahoma/Kansas border and the latest runs of the HRRR support this activity continuing for the next few hours as it progresses to the south and southeast. As such, have raised pops considerably overnight across northeast Oklahoma and northwest Arkansas. The showers and storms are still expected to weaken and dissipate before reaching southeast Oklahoma so will maintain a dry forecast there. The current low temperature forecast appears reasonable at this time. Update on the way. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...06
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
902 PM EDT SAT OCT 17 2015 .SYNOPSIS... A DEEP UPPER LEVEL TROUGH OVER EASTERN CANADA AND THE NORTHEAST CONUS WILL BRING BELOW NORMAL TEMPERATURES TO CENTRAL PA THIS WEEKEND. WIDESPREAD NIGHTTIME FREEZING CONDITIONS WILL LIKELY END THE GROWING SEASON. THE WEEKEND CHILL WILL BE SHORT-LIVED AS A MILDER PATTERN DEVELOPS THROUGH NEXT WEEK...WITH TEMPERATURES NEAR TO ABOVE NORMAL FOR LATE OCTOBER. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... COVERAGE OF SHOWERS DIMINISHING EARLY THIS EVENING AS BLYR COOLS/STABILIZES. EXPECT COVERAGE TO DWINDLE FURTHER LATE THIS EVENING...AS MID LVL SHORTWAVE PASSES EAST OF THE AREA. LG SCALE SUBSIDENCE IN THE WAKE OF THIS FEATURE SHOULD END THE CHANCE OF PRECIP ACROSS THE LOWER SUSQ VALLEY BY ARND 03Z. ACROSS THE ALLEGHENY PLATEAU...LAKE EFFECT SNOW SHOWERS SHOULD PERSIST OVERNIGHT. HOWEVER...FALLING INVERSION HGT SHOULD LIMIT THE INTENSITY OF LE SNOW. BLEND OF LATEST HRRR AND CONSALL QPF SUPPORT THE IDEA OF LOCALIZED ADDITIONAL SNOW ACCUMS OVERNIGHT OF 1-2 INCHES ACROSS WARREN CO...WITH LITTLE IF ANY ELSEWHERE. THE CASE FOR A WIDESPREAD FREEZE /ESP ACROSS THE LOWER SUSQ VALLEY/ APPEARS TO BE WEAKENING...DUE TO LINGERING LE STRATOCU AND AN ACTIVE NW BREEZE. WILL KEEP CURRENT HEADLINES INTACT FOR NOW...AS BUT MAY NEED TO MAKE ADJUSTMENTS LATER THIS EVENING. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... THE 850MB THERMAL TROUGH /-4C TO -8C/ WILL MOVE THROUGH ON SUNDAY WITH ONE MORE DAY OF SEASONABLY COLD...SHOWERY WEATHER. THE GREATEST COVERAGE OF SHOWERS WILL COME DURING THE LATE AM-MID AFTN WITH PASSAGE OF POTENT MID LVL VORT MAX. MODELS STILL SUGGEST SHOWER ACTIVITY REACHES INTO THE LWR SUSQ VLY COINCIDENT WITH THE STEEP MID LEVEL LAPSE RATES AND RELATIVELY STRONG FORCING ASSOCD WITH THE AFOREMENTIONED SHORTWAVE. HIGH PRESSURE WILL MIGRATE EWD FROM THE LWR OH VALLEY LATER SUNDAY AND TAKE UP RESIDENCE OVER THE NORTH CENTRAL APPALACHIANS BY 12Z MONDAY. THE INCREASING LG SCALE SUBSIDENCE AND BACKING LOW LEVEL TRAJECTORIES WILL SPELL AN END TO THE LAKE EFFECT ACTIVITY SUN NGT. THERE SHOULD ALSO BE A DECREASE IN STRATOCU WITH A GOOD DEAL OF CLEARING EXPECTED. THIS NIGHTTIME RADIATIONAL COOLING SET-UP SHOULD PROVE MORE FAVORABLE FOR COLDER MIN TEMPS...WITH READINGS DROPPING BELOW FREEZING ACROSS THE ENTIRE CWA /25 TO 30F/. A FREEZE WATCH REMAINS IN EFFECT FOR LATE SUNDAY NIGHT INTO EARLY MORNING. CONFIDENCE IS HIGH THAT THIS WATCH WILL BE UPGRADED TO A FREEZE WARNING WHICH SHOULD BRING THE GROWING SEASON TO A CLOSE IN CENTRAL PA. && .LONG TERM /MONDAY THROUGH SATURDAY/... HIGH PRESSURE/RIDGING ALOFT SHOULD PROVIDE FAIR AND MAINLY DRY WEATHER FOR MUCH OF NEXT WEEK. THE PATTERN WILL ALSO TURN MILDER WITH DAYTIME TEMPERATURES REBOUNDING NEAR AND EVENTUALLY ABOVE SEASONAL NORMS TUE-THR. A FRONTAL BOUNDARY EXTENDING FROM THE GREAT LAKES NEWD INTO SOUTHEAST CANADA LOOKS LIKE IT WILL STALL OUT NEAR OR JUST NORTH OF PA AS IT PUSHES SWD ON TUESDAY. WPC PROGS SHOW LOW PRES FORMING IN THE PLAINS AND TRACKING NEWD THROUGH THE GREAT LAKES...DRAGGING A MSTR-STARVED COLD FRONT ACROSS PA ON THURSDAY. HIGH PRESSURE IS FCST TO FOLLOW IN THE WAKE OF THE FRONT WITH COLDER WX LKLY BY FRIDAY. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... VERY MINOR CHANGES MADE TO THE 00Z TAFS. EXPECT A FEW MORE HOURS OF RATHER HEAVY RAIN AND SNOW SHOWERS...AS THE HEATING TAPERS OFF. COLDER OUTSIDE AT 4 PM...WHEN I CAME IN...35 DEGREES...THAN WHEN I LEFT AT 7 AM THIS MORNING...40 DEGREES. SOME OF THE SNOW SHOWERS BEEN ON THE HEAVY SIDE. WIDE RANGE IN CONDITIONS. SITES GO FROM VFR TO IFR FOR A FEW MINUTES...THEN BACK TO VFR. CONDITIONS WILL SLOWLY IMPROVE DURING THE LATER PART OF SUNDAY...AS HIGH PRESSURE STARTS TO BUILD TOWARD PA. OUTLOOK... MON-WED...MAINLY VFR. NO SIG WX EXPECTED. THU...MAINLY VFR...BUT A FEW SHOWERS POSSIBLE...MAINLY N PA. && .CTP WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY MORNING FOR PAZ019-025>028-034>036-045-046-049>053-056>059-063>066. FREEZE WARNING FROM 3 AM TO 9 AM EDT SUNDAY FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. && $$ SYNOPSIS...ROSS NEAR TERM...FITZGERALD SHORT TERM...ROSS/FITZGERALD LONG TERM...GARTNER/STEINBUGL AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
242 AM EDT FRI OCT 16 2015 .SYNOPSIS... AN AMPLIFIED UPPER LEVEL TROUGH OVER EASTERN CANADA WILL DOMINATE THE REGIONAL WEATHER PATTERN THROUGH THE WEEKEND WITH TEMPERATURES AVERAGING BELOW NORMAL. A WEAK FRONT WILL MOVE THROUGH TOMORROW AND FROST/FREEZE CONDITIONS THIS WEEKEND WILL LIKELY BRING AN END TO THE GROWING SEASON. THE SEASONABLY COLD NORTHWEST FLOW WILL LOSE ITS GRIP ON THE AREA NEXT WEEK WITH FAIR WEATHER AND MILDER TEMPERATURES EXPECTED THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... 10 PM UPDATE... SHOWERS MOVING STEADILY BUT SLOWLY THROUGH THE NRN MTNS. FINE LINE OF COOLER AIR/GUST FRONT MOVING THROUGH KDUJ/KPIT RIGHT NOW AND MAY SIGNAL A LITTLE WEAKENING/FRACTURING IS POSSIBLE SOON. A COUPLE OF LINES OF STORMS FIRED UP IN WRN NY AND THE CURRENT ONE IS LESS THAN A COUNTY AWAY FROM THE PA BORDER. SUSPECT THIS LINE IS THE REAL FRONT - WITH A DECENT WIND SHIFT BEHIND IT. SOME 50KT WINDS WILL SNEAK INTO FAR NRN PA AROUND MIDNIGHT...BUT THE STABLE/COOL LAYER IN PLACE FROM THE CURRENT RAIN SHOULD HELP TO MINIMIZE GUST POTENTIAL. GUSTS INTO THE 30S ARE STILL POSSIBLE IN THE EXTREME NORTHERN TIER THOUGH. WILL HOLD OFF ON MENTIONING THUNDER FOR NOW. BUT A STRAY RUMBLE IS POSSIBLE. HAVE BLENDED THE GOING FCST WITH THE HRRR MDL RADAR PROGS FOR THE REST OF THE NIGHT. THIS MATCHES WELL WITH THE PREV FCST AND PROVIDES SOME SLIGHTLY REFINED TIMING/COVG. TEMPS ARE ON TRACK. CLOUDS HOLDING OFF UNTIL JUST BEFORE THE PRECIP ARRIVES. PREV... BAND OF SHOWERS PARALLEL TO THE LOWER LAKES IS SLIDING TO THE ESE ON SCHEDULE. THE RAIN IS NOT PARTICULARLY HEAVY...BUT THE DYNAMICS MUST BE PRETTY STRONG WITH LIGHTNING NOW OCCURRING IN ERIE. COULD GUST INTO THE 30S IN ONE OF THE HEAVIER CELLS AS WINDS NOT TOO FAR ALOFT ARE CLOSE TO 35KTS...AND INCREASE/LOWER THROUGH THE NIGHT. CLOUD BAND STAYS RATHER COHERENT AS IT SLIPS TO THE SE THROUGH THE NIGHT. HOWEVER...THE MOISTURE DECREASES AND LITTLE MORE THAN SPRINKLES SHOULD BE LEFT BY 2/3AM AS IT GETS INTO THE LOWER SUSQ. SOME CLEARING MAY TRY TO TAKE PLACE AFTER THE MAIN BAND GOES BY BUT THE CAA AFTERWARD WILL LIKELY CREATE ADDITIONAL/UPSLOPE CLOUDS IN THE NW. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/... ALL MDL DATA TRACKS COLD FRONT EAST OF THE AREA BY 12Z FRIDAY. ADVECTION OF LOW PWAT AIR MASS IN WAKE OF FRONT SHOULD ENSURE A DRY FRIDAY OVER MOST OF CENTRAL PA. HOWEVER...A SECONDARY SHORTWAVE/COLD FRONT WILL BE DIVING SE FROM THE GRT LKS LATE IN THE DAY...LIKELY SPREADING SCT SHOWERS INTO THE NW COUNTIES BY LATE AFTN. ANY QPF FROM THESE SHOWERS SHOULD BE LIGHT. GEFS MEAN 925TEMPS ARND 5C SHOULD TRANSLATE TO MAX TEMPS FROM THE L50S OVR THE NW MTNS...TO THE M60S ACROSS THE LOWER SUSQ VALLEY. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A COOL SHOWERY REGIME WILL PERSIST AT THE BEGINNING OF THE EXTENDED FORECAST PERIOD AS DEEP CANADIAN UPPER TROF TRACKS FROM EASTERN ONTARIO AND WESTERN QUEBEC FRIDAY NIGHT THROUGH QUEBEC AND NORTHERN NEW ENGLAND SATURDAY NIGHT AND SUNDAY...AND EAST OF NEWFOUNDLAND BY LATE MONDAY AND TUESDAY. THIS TROF WILL DELIVER THE CHILLIEST AIR OF THE SEASON THUS FAR AND A WIDESPREAD CHC OF FLURRIES AND LIGHT SNOW SHOWERS TO WESTERN AND NORTHERN SECTIONS LATER SATURDAY...SATURDAY NIGHT AND SUNDAY. IN ADDITION...A LAKE SUPERIOR/HURON CONNECTION SHOULD SUPPORT A BAND OF MORE SOMEWHAT MORE SUBSTANTIAL LAKE EFFECT SNOW SHOWERS ACROSS THE NW MTNS. AS EARLIER NOTED...BLYR AND GROUND TEMPS WILL LIKELY REMAIN TOO WARM FOR ACCUMS UNTIL SATURDAY NIGHT. SUSPECT THERE WILL BE A DUSTING OF SNOW ACROSS THE NORTHWEST MOUNTAINS SATURDAY NIGHT INTO SUNDAY. LITTLE CHANGE SEEN IN OVERALL DETAILS TODAY AS COLD POOL CROSSES THE STATE SUNDAY...FOLLOWED BY LARGE SCALE RIDGING AND A RETURN TO NICE FALL WEATHER FOR MONDAY AND TUESDAY. MAIN FORECAST ISSUE IS ON THE COLD FOR SUNDAY MORNING...WHICH IS LIKELY TO END THE GROWING SEASON FOR THE REST OF CENTRAL PA...AND ON TIMING OF ARRIVAL OF APPROACHING FRONT TOWARDS MIDWEEK OR BEYOND AS SFC HIGH REMAINS LODGED ALONG AND JUST OFF THE MID ATLANTIC COAST BY WED/THU. INTRODUCED SLGT/CHC SHOWERS ON WEDNESDAY AFTERNOON...WHICH LINGERS THU AND FRI AS SLOW MOVING FRONT SAGS ACROSS THE REGION. ALTHOUGH MUCH OF THE AREA WILL LIKELY EXPERIENCE A FREEZE SAT NIGHT... STILL EXPECT THE COLDEST TEMPS TO OCCUR SUN NIGHT...AS SFC HIGH BUILDS INTO THE REGION. CLEAR SKIES AND A LGT WIND SHOULD ALLOW TEMPS TO FALL BLW FREEZING OVR NEARLY THE ENTIRE CWA WITH WIDESPREAD FROST LIKELY. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... PROGRESSIVE COLD FRONT TRAILING SWWD FROM SFC LOW PRES MOVG ACROSS SOUTHEAST CANADA WILL MOVE THRU THE AIRSPACE EARLY THIS MORNING. A NARROW CORRIDOR OF -SHRA WILL ACCOMPANY THE FRONT AND IMPACT THE NW 1/2 OF THE AIRSPACE. HIRES MDL DATA SUGGESTS -SHRA DO NOT REACH THE MDT/LNS VCNTY. SATL TRENDS SUGGEST POST FRONTAL MVFR TO LOW VFR CIGS SHOULD IMPROVE FAIRLY QUICKLY FROM WEST TO EAST THIS MORNING. VFR FLYING EXPECTED TO PREVAIL THIS AFTN WITH OCNL WIND GUSTS FROM 270-300 BTWN 15-20KTS. LAKE EFFECT -SHRA SHOULD INCREASE OVER THE NW 1/3 AFT 00Z WITH REDUCTIONS LKLY AT BFD INTO TONIGHT. SOME -SHSN MAY MIX WITH -SHRA AFT MIDNIGHT. THE COLD NW FLOW PATTERN WILL GRIP THE AREA THRU THE WEEKEND WITH PERSISTENT LAKE EFFECT -SHRASN AND MVFR CIGS EXPECTED OVER THE NW 1/3...WHILE LOW VFR CIGS RULE EAST OF THE WESTERN HIGH TERRAIN. HIGH PRESSURE RETURNS FOR EARLY NEXT WEEK WITH HIGH CONFIDENCE IN VFR. OUTLOOK... SAT-SUN...MVFR CIGS/-SHRASN WRN TAFS. LOW VFR CIGS CNTRL/EAST. WIND GUSTS 15-20KTS FROM 280-310. MON-TUE...VFR. NO SIG WX EXPECTED. && .EQUIPMENT... KCCX RADAR IS DOWN UFN. ET IS ON SITE. PROBLEM APPEARS TO BE WITH RDARTR LINK/CONNECTION FAILURE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CERU/STEINBUGL NEAR TERM...DANGELO SHORT TERM...FITZGERALD/CERU LONG TERM...DEVOIR AVIATION...STEINBUGL EQUIPMENT...STEINBUGL
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1207 AM CDT FRI OCT 16 2015 .UPDATE... UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... /ISSUED 906 PM CDT THU OCT 15 2015/ DISCUSSION... COLD FRONT IS PUSHING THROUGH THE MIDSOUTH THIS EVENING. KNQA SHOWING A NICE FINE LINE MOVING SOUTH ACROSS THE MEMPHIS METRO ATTM. POST FRONTAL SHOWERS ARE ABOUT 100 MILES NORTH OF THE FRONT ACROSS SOUTHERN MISSOURI. COLD FRONT WILL CONTINUE TO MOVE SOUTH OVERNIGHT AND CLOUDS WILL INCREASE BEHIND THE FRONT ACROSS NORTHERN SECTIONS. A FEW SHOWERS WILL WORK SOUTH INTO NORTHERN AREAS OF THE MIDSOUTH. EXPANDED THE SLIGHT CHANCE POPS A LITTLE FURTHER SOUTH AFTER MIDNIGHT GIVEN AMOUNT OF COVERAGE ACROSS SOUTHERN MISSOURI AND LATEST HRRR DATA. EXPECT COVERAGE TO DIMINISH AS THE SHOWERS HEAD SOUTH AND LIFT ACROSS THE REGION WEAKENS. WINDS WILL START PICKING UP BEHIND THE FRONT...SPREADING SOUTH BY MORNING. THIS WILL KEEP THE BOUNDARY LAYER MIXED UP AND...ALONG WITH ANY CLOUDS...PREVENT TEMPS FROM DROPPING TOO FAR BY MORNING. FORECAST LOW TEMPS IN THE 50S LOOKS GOOD. UPDATE ALREADY OUT. SJM && .PREV DISCUSSION... /ISSUED 244 PM CDT THU OCT 15 2015/ CURRENTLY TEMPERATURES WERE RANGING FROM NEAR 80F ALONG THE LOWER TENNESSEE RIVER...TO RECORD BREAKING LOW 90S FROM THE MEMPHIS METRO DOWN THROUGH THE SOUTHWEST DELTA COUNTIES. WINDS WERE SOUTH THROUGH SOUTHWEST AT 5 TO 10 KTS...WITH OCCASIONAL HIGHER GUSTS. DRY CONDITIONS CONTINUE WITH RELATIVE HUMIDITY BELOW 30 PERCENT. FOR TONIGHT THROUGH SUNDAY...A DRY COLD FRONT WILL PASS THROUGH THE MIDSOUTH TONIGHT...BRINGING A BRIEF PERIOD OF SCATTERED CLOUDS AND MAYBE AN ISOLATED LIGHT SHOWER ACROSS THE NORTH...OTHERWISE A VERY DRY AND COOL WEEKEND IS IN STORE. THOUGH HIGH TEMPERATURES WILL DROP NEARLY 20 DEGREES TOMORROW SO WILL DEWPOINTS. FROM THIS GUSTY NORTH WINDS WILL RAISE MORE FIRE WEATHER CONCERNS...WITH POSSIBLE RED FLAG CONDITIONS ACROSS ARKANSAS AND MISSISSIPPI. NOT MUCH CHANGE EXPECTED ON SATURDAY...THOUGH WINDS SHOULD BE A TAD LIGHTER. THE BRUNT OF THE CANADIAN AIRMASS WILL SETTLE INTO THE REGION BY SATURDAY AFTERNOON...WITH WIDESPREAD HIGHS IN THE 60S. FOR NOW HAVE INTRODUCED AREAS OF FROST ACROSS THE NORTH AND EASTERN COUNTIES BOTH SATURDAY AND SUNDAY MORNING...BUT QUESTIONS ARISE ON WHETHER ENOUGH MOISTURE WILL HUG THE GROUND FOR FROST TO EVEN FORM...SO MADE MENTION OF THE POTENTIAL IN THE AFTERNOON HWO. SUNDAY WILL REMAIN DRY AND COOL WITH LIGHT EAST TO SOUTHEAST WINDS AS THE HIGH CENTER MOVES EAST. MONDAY THROUGH THURSDAY...LONG RANGE MODELS SHOW AN UPPER RIDGE SLIDING EAST OVER THE MISSISSIPPI VALLEY AND APPALACHIANS AS A TROUGH DIGS INTO THE SOUTHERN ROCKIES AND ANOTHER IN THE UPPER MIDWEST. THIS PATTERN WILL KEEP THE MIDSOUTH DRY INITIALLY WITH A SLOW RETURN OF MOISTURE BY MIDWEEK AHEAD OF THE NEXT DROPPING COLD FRONT. RAIN CHANCES WILL BE MINOR HOWEVER AS THE NORTHERN TROUGH LIFTS OUT AND THE SOUTHERN ENERGY IS PROGGED TO STALL OVER NW MEXICO. TEMPERATURES THIS PERIOD WILL WARM TO NEAR SEASONAL NORMS EARLY WITH A RETURN TO ABOVE NORMAL READINGS BY WEDNESDAY. JAB && .AVIATION... 06Z TAF CYCLE VFR CONDITIONS EXPECTED OVER NEXT 24 HOURS. POST FRONTAL SHOWERS AND A FEW ISOLATED THUNDERSTORMS WILL CONTINUE NEAR JBR FOR THE NEXT COUPLE HOURS...WARRANTING A VCSH THROUGH EARLY MORNING. WINDS WILL REMAIN BRISK OVERNIGHT NEAR MEM AND JBR...WITH OCCASIONAL WIND GUSTS TO 16 KTS OR GREATER. LLWS IS BELOW CRITERIA ...BUT WILL REMAIN NEAR 25 KTS FOR A FEW HOURS AS WINDS AT 2000 FEET ARE 35 KTS AS SEEN ON NQA VAD WIND PROFILER. WINDS WILL REMAIN 12-16 KTS GUSTING TO AROUND 25KTS AT ALL SITES TOMORROW AFTERNOON. HIGH PRESSURE WILL SETTLE IN AT THE SURFACE LATE IN THE PERIOD AND WINDS WILL SUBSIDE TO LESS THAN 6 KTS. AC3 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FIRE WEATHER WATCH FROM 7 AM CDT FRIDAY THROUGH SATURDAY EVENING FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR- MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...NONE. MS...FIRE WEATHER WATCH FROM 7 AM CDT FRIDAY THROUGH SATURDAY EVENING FOR ALCORN-BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO- ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC- PRENTISS-QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA- UNION-YALOBUSHA. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
900 PM PDT SAT OCT 17 2015 .SYNOPSIS...A WEAK UPPER TROUGH WILL MOVE SLOWLY ACROSS THE PACIFIC NORTHWEST TONIGHT AND SUNDAY...BRINGING LIGHT SHOWERS TO WESTERN WASHINGTON. A WEAK FRONT WITH AREAS OF LIGHT RAIN WILL REACH THE AREA MONDAY. SUNNY WEATHER WILL RETURN ON TUESDAY AS AN UPPER RIDGE MOVES OVER THE REGION. ANOTHER WEAK FRONT WILL ARRIVE WEDNESDAY NIGHT OR THURSDAY. && .SHORT TERM...LATEST RADAR LOOP AND OBS SHOW AN AREA OF LIGHT RAIN CONCENTRATED OVER GREATER PUGET SOUND TOWARD THE CENTRAL CASCADES/FOOTHILLS. 3 HOUR RAIN TOTALS IN THESE AREAS RANGE FROM A FEW TENTHS IN SOME LOWLAND SPOTS TO A QUARTER INCH OR LOCALLY MORE ALONG SOME OF THE FOOTHILL AND CASCADE LOCATIONS. SHOWERS REMAIN SCATTERED ELSEWHERE WITH LITTLE OR NO MEASURABLE PRECIP SINCE THE AFTERNOON. NONE OF THE MODELS ARE DOING PARTICULARLY WELL WITH THE CURRENT PRECIP PATTERN...THOUGH THE 02Z HRRR AT LEAST ACKNOWLEDGES SOME CONCENTRATED QPF AROUND GREATER PUGET SOUND. EVEN THIS MODEL SHOWS RAIN DISSIPATING IN THE NEXT HOUR OR TWO WITH JUST SPRINKLES OR HIT AND MISS SHOWERS BEFORE MIDNIGHT. THE KATX RADAR DOES SEEM TO HINT AT A SLIGHT DECREASING TREND SO THE HRRR MAY NOT BE FAR OFF BASE. WILL LEAVE CHANCE POPS IN PLACE TONIGHT. A 500 MB CUT OFF LOW DIGS WELL S OF OUR REGION...SETTLING OVER CA/NV ON SUNDAY. ABUNDANT LOW LEVEL MOISTURE WILL STICK AROUND WRN WA SUNDAY WITH WEAK DEFORMATION ALOFT AND A RESIDUAL SURFACE TROUGH DISSIPATES AS IT MOVES ONSHORE. THIS COULD TRIGGER ADDITIONAL SHOWERS BUT QPF SHOULD BE GENERALLY LIGHT AND SPOTTY ONCE AGAIN. HIGHS WILL GENERALLY BE IN THE LOW 60S OVER THE INTERIOR METRO AREAS. MODELS CONSENSUS REMAINS POOR WITH A LOT OF WAFFLING FROM RUN TO RUN REGARDING THE STRENGTH AND TRACK OF THE NEXT FRONTAL SYSTEM. THE LATEST 18Z RUNS ARE IN SOMEWHAT BETTER AGREEMENT SHOWING A MORE CONSOLIDATED SYSTEM COMPARED TO PREVIOUS RUNS. HOWEVER...I DO NOT TOTALLY BUY INTO THE STRENGTH OF THE SYSTEM SHOWN BY SOME 18Z RUNS GIVEN THE EXTENT OF THE LARGE SCALE SPLIT UPPER AIR PATTERN. A WEAKER SYSTEM DIGGING SWD SEEMS MORE LIKELY BUT CONFIDENCE IS TOO LOW TO MAKE ANY CHANGES TO THE FORECAST WHICH IS ALREADY BROADLY HANDLED WITH REGARDS TO TIMING AND QPF. MONDAY SHOULD BE COOLER WITH A CONTINUED THREAT OF SHOWERS AND HIGHS STRUGGLING TO REACH 60. THE MAJORITY OF MODELS SHOW STRONGER RIDGING OVER THE PAC NW TUESDAY INTO MID WEEK. EXPECT A PERIOD OF DRY WEATHE. IT IS FOG SEASON SO ANY SUNSHINE COULD BE LATE IN BREAKING OUT. MERCER .LONG TERM...PREVIOUS DISCUSSION FOLLOWS...WEDNESDAY ALSO LOOKS DRY AS MODELS HAVE BACKED OFF SLIGHTLY ON THE PROGRESSION OF THE NEXT SYSTEM. THE GFS AND EURO BRING ANOTHER WEAK SYSTEM INTO THE AREA WEDNESDAY NIGHT AND THURSDAY. HOWEVER THE EURO HAS WEAKENED THIS SYSTEM ALMOST TO OBLIVION SO WILL JUST HAVE CHANCE POPS FOR NOW. AFTER THAT BOTH MODELS ARE FAIRLY DRY UNTIL SATURDAY OR SUNDAY WHEN THE NEXT SYSTEM ARRIVES. FOR NOW HAVE KEPT LOW CHANCE POPS EACH PERIOD THROUGH SATURDAY. BURKE && .AVIATION... IN THE IMMEDIATE SHORT TERM...BANDS OF SHOWERS CONTINUING TO LIFT NORTH ACROSS THE AREA FROM THE PUGET SOUND TO THE EAST. CONDITIONS HAVE TRENDED TOWARDS MVFR WITH THIS SHOWER ACTIVITY. LIGHT WINDS OVERNIGHT WILL CONTINUE TO FAVOR MVFR TO IFR CONDITIONS. SHOWERS WILL DIMINSH IN COVERAGE OVER THE AREA OVERNIGHT AND THEN DIMINISH AFTER 12Z SUN AT THE TERMINALS BUT HUMIDITY WILL REMAIN HIGH AND SO CIGS WILL REMAIN LOWER IN THE MVFR RANGE. KSEA...A FEW SHOWERS AT THE TERMINAL THIS EVENING WILL PRODUCE MVFR CONDITIONS AND THEN TRENDING TO IFR NEAR OR AFTER 12Z SUNDAY MORNING. LIGHT WINDS BECOMING LIGHT SOUTHWEST WIND 3-5 KT BECOMING LIGHT AND VARIABLE AFTER 03Z. MVFR CIGS EXPECTED THRU THE DAY SUN UNTIL END OF PERIOD. && .MARINE... GENERALLY QUIET WEATHER...A WEAK LOW PRESSURE AND DECAYING COLD FRONT MOVING INTO THE COASTAL WATERS TONIGHT. WINDS TO REMAIN BELOW 20 KT ALL WATERS. A WEAK HIGH PRESSURE WILL CROSS THE COASTAL WATERS...FOLLOWED BY THE CHANCE OF ANOTHER PACIFIC STORM SYSTEM BY EARLY THIS COMING WEEK. WINDS WILL INCREASE IN THE FARTHER OFFSHORE WATERS MONDAY AND INTO TUESDAY. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. PZ...NONE. && $$ WWW.WEATHER.GOV/SEATTLE YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 229 PM CDT FRI OCT 16 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM CENTRAL CANADA TO THE WESTERN GULF OF MEXICO EARLY THIS AFTERNOON. EAST OF THE RIDGE AXIS...COLD CYCLONIC FLOW CONTINUES OVER THE WESTERN GREAT LAKES REGION. RECEIVED SEVERAL REPORTS OF FLURRIES OVER CENTRAL AND NORTH-CENTRAL WI EARLY THIS MORNING...BUT THOSE REPORTS DRIED UP BY LATE IN THE MORNING. SCATTERED TO BROKEN CLOUDS ARE PREVAILING ACROSS MUCH OF THE REGION EARLY THIS AFTERNOON...BUT THESE CLOUDS ARE GRADUALLY MIXING OUT OVER CENTRAL WI. THIS TREND SHOULD SPREAD EAST FOR THE REST OF THE AFTERNOON AWAY FROM THE LAKE EFFECT BELTS. LOOKING UPSTREAM...A FAIRLY SOLID CLOUD MASS IS DIVING SOUTHEAST OVER THE LAKE WINNIPEG/NORTHERN MINNESOTA REGION. CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS IN THE SHORT TERM. TONIGHT...CANADIAN HIGH PRESSURE WILL BE SHIFTING EAST ACROSS THE NORTHERN MISSISSIPPI VALLEY AND INTO THE WESTERN GREAT LAKES. LOW LEVEL WINDS WILL REMAIN OUT OF THE NORTHWEST...AND BRING IN SCATTERED CLOUD COVER OFF LAKE SUPERIOR...WITH AREAS OF BROKEN CLOUDS AT TIMES...INTO NORTH-CENTRAL AND PARTS OF NE WISCONSIN. SCATTERED FLURRIES WILL LIKELY CONTINUE OVER THE NORTHERN HALF OF VILAS CO. THEN MODELS PROJECT THE AREA OF OVERCAST OVER LAKE WINNIPEG WILL ARRIVE AFTER MIDNIGHT INTO N-C WI. PERHAPS WILL SEE A SLIGHT UPTICK IN ANY LAKE EFFECT SNOW SHOWERS IN THE SNOW BELTS. ELSEWHERE...AC DECK OVER MINNESOTA LOOKS TO SLIDE SOUTH OF THE REGION. SO SHOULD SEE CLEARING THIS EVENING OVER CENTRAL AND EAST- CENTRAL WI AS DIURNAL HEATING IS LOST. LOW LEVEL WINDS SHOULD REMAIN IN THE 15-20 KT RANGE...WHICH SHOULD BE GOOD FOR THE COLD SPOTS TO BECOME CALM FOR PERIODS. REMAINED CONSERVATIVE WITH LOWS HOWEVER...DUE TO UNCERTAINTY WITH CLOUD COVER. A HARD FREEZE/FROST STILL LOOKS GOOD FOR THE FOX VALLEY/LAKESHORE. SATURDAY...HIGH PRESSURE WILL SHIFT TOWARDS THE CENTRAL MISSISSIPPI VALLEY. WINDS WILL START OUT FROM THE NORTHWEST..THEN BACK MORE WESTERLY THROUGH THE DAY. AS A RESULT...ANY LAKE CLOUDS AND FLURRIES ACROSS THE NORTH SHOULD RETREAT TOWARDS THE UPPER PENINSULA THROUGH THE DAY. SHOULD STILL SEE SCATTERED TO BROKEN CLOUDS ACROSS THE NORTHERN HALF OF THE FORECAST AREA FROM THE MOISTURE ORIGINATING OVER LAKE WINNIPEG. HIGHS TO BE A FEW DEGREES WARMER THAN TODAYS READINGS. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 229 PM CDT FRI OCT 16 2015 ANOTHER COLD NIGHT EXPECTED SATURDAY NIGHT AS THE SURFACE RIDGE DRIFTS OVER THE GREAT LAKES REGION. ANTICIPATED CLEAR OR CLEARING SKIES...LIGHT WINDS TO COMBINE WITH THE COOL DRY AIR MASS TO POSSIBLY PRODUCE WIDESPREAD FREEZING TEMPERATURES AGAIN BY SUNDAY MORNING. POSSIBLY ADDITIONAL FROST OR FREEZE HEADLINES WILL BE NEEDED OVER EAST CENTRAL WISCONSIN. RETURN FLOW DEVELOPS SUNDAY AND CONTINUES INTO MONDAY AS THE HIGH PRESSURE RIDGE DRIFTS EAST. PROGS CONTINUE TO SUGGEST VERY LIGHT SHOWERS DEVELOPING IN THE H850 WARM PROD REGION OVER NORTHEAST WISCONSIN LATER MONDAY INTO MONDAY EVENING. SINCE THE AIR MASS WILL BE MOISTURE STARVED INITIALLY...WILL FOCUS ANY LOW END CHC POPS ALONG THE SURFACE FRONT. FORECAST ISSUE TURNS TO WHERE THIS FRONT STALLS MONDAY NIGHT INTO TUESDAY PRIOR TO A SURFACE WAVE TRACKING ALONG THIS FRONT TUESDAY NIGHT INTO WEDNESDAY. CONSENSUS OF AVAILABLE 12Z PROGS SUGGESTS A MORE SOUTHERN LOCATION OF THE FRONT LATE MONDAY INTO TUESDAY FOR A DIMINISHED PCPN CHC TREND OR EVEN DRY AND CERTAINLY COOLER. MEDIUM RANGE MODELS TARGETING THE BEST CHANCE OF RAIN TOWARD MID WEEK OR TUESDAY NIGHT INTO WEDNESDAY EVENING AS THE SURFACE WAVE TRACKS OVER SOUTHERN WISCONSIN. HIGH PRESSURE TO SETTLE BACK INTO THE REGION FOR LATER IN THE WEEK FOR A TURN TO DRIER CONDITIONS. ABOVE NORMAL TEMPERATURES EXPECTED MONDAY. SINCE THE FRONT IS EXPECTED TO SAG A BIT FURTHER SOUTH...TEMPERATURES LIKELY WILL BE IN THE COOLER BUT CLOSER TO NORMAL RANGE. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1201 PM CDT FRI OCT 16 2015 SCATTERED TO BROKEN LOW CLOUDS WILL CONTINUE TO IMPACT THE REGION THROUGH THE AFTERNOON. MVFR CIGS ARE POSSIBLE OVER NORTH- CENTRAL WISCONSIN INTO MID-AFTERNOON BEFORE LIFTING. CLEARING IS LIKELY TONIGHT AWAY FROM THE LAKE EFFECT BELTS OF N-C WISCONSIN...BUT KEPT SCATTERED WORDING AT MOST SITES DUE TO UNCERTAINTY. SCATTERED TO BROKEN 4000-7000FT CLOUDS ARE ANTICIPATED FOR SATURDAY WITH LIGHTER WINDS. && .GRB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 10 PM THIS EVENING TO 9 AM CDT SATURDAY FOR WIZ022-038>040-048>050. && $$ SHORT TERM.....MPC LONG TERM......TDH AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GOODLAND KS
145 AM MDT SUN OCT 18 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 137 PM MDT SAT OCT 17 2015 EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS INDICATED LONGWAVE TROUGH ACROSS THE EASTERN US WITH RIDGING ACROSS THE PLAINS AND INTO THE NORTHERN ROCKIES. A CLOSED UPPER LOW IS OFF THE NORTHERN CALIFORNIA COAST. SURFACE LOW PRESSURE HAS DEVELOPED OVER NORTH CENTRAL COLORADO WITH TIGHT SOUTHERLY GRADIENT ACROSS THE PLAINS RESPONSIBLE FOR BREEZY-WINDY CONDITIONS ACROSS OUR CWA. TONIGHT-SUNDAY...CLOSED LOW OFF PACIFIC NW WILL SHIFT TOWARDS THE GREAT BASIN AND WITH A WEAKER SHORTWAVE TROUGH ROTATING AROUND NORTHERN EDGE OF UPPER RIDGE INTO THE NORTHERN PLAINS. WEAK FORCING WILL BE RESPONSIBLE FOR PERIODS OF HIGH CLOUD COVER OTHERWISE A DEEP DRY LAYER IN PLACE WILL PREVENT PRECIP DEVELOPMENT IN OUR CWA THROUGH SUNDAY AFTERNOON. LEE TROUGH WILL SHIFT EAST OVER OUR CWA WITH INCREASING WAA AND UNSEASONABLY WARM TEMPERATURES RETURNING. BASED ON MIXING HEIGHTS/TEMPS ALOFT WE SHOULD SEE HIGHS AROUND 80F WHICH IS ABOUT 15F ABOVE NORMAL SUNDAY. LOWS TONIGHT WILL BE TRICKY AS A RESULT OF A MODERATELY STRONG LLJ INCREASING BL MIXING...HOWEVER LOCATIONS IN THE NORTH AND ALONG VALLEYS SHOULD STILL BE ABLE TO DECOUPLE AND COOL TO AROUND 40F. WE MAY ALSO SEE A PERIOD OF LIGHT FOG DEVELOP ALONG VALLEYS/LOW AREAS IN OUR NW ALONG SURFACE TROUGH AS LOW LEVEL MOISTURE INCREASES. CONFIDENCE WAS TOO LOW AT THIS TIME TO INCLUDE MENTION DUE TO EXPECTED MIXING...BUT WE WILL NEED TO MONITOR. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 142 AM MDT SUN OCT 18 2015 THE EXTENDED PERIOD BEGINS WITH THE APPROACH OF A CUT OFF AREA OF LOW PRESSURE AND ASSOCIATED SLIGHTLY NEGATIVE TROUGH. THIS LOW WILL MOVE NORTHEASTWARD THROUGH THE DAY ON WEDNESDAY AND INTO EARLY THURSDAY. GUIDANCE IS IN GOOD AGREEMENT WITH REGARDS TO THE LOW OPENING AND BECOMING A PART OF THE MAIN TROUGH HOWEVER TEMPORAL AGREEMENT IS WEAK. POPS ON WEDNESDAY WILL BE IN THE 30 TO 50 PERCENT RANGE NORTH TO SOUTH AS THE SOUTHERN PORTION OF THE CWA WILL HAVE SLIGHTLY BETTER OMEGA VALUES THANKS TO FAVORABLE POSITIONING OF THE JET. THIS AXIS WILL SHIFT NORTH AS WE HEAD INTO THURSDAY WITH MUCH OF THE CWA NOW POTENTIALLY SEEING 40 TO 60 PERCENT POPS ESPECIALLY DURING THE MIDDAY TO EARLY AFTERNOON HOURS. THE SYSTEM WILL SLOWLY MOVE OFF TO THE NORTH AND EAST EARLY FRIDAY WITH SHOWERS AND EMBEDDED THUNDERSTORMS TAPERING OFF FROM WEST TO EAST DURING THE DAY. THE EASTERN PORTIONS OF THE CWA WILL SEE RAIN CHANCES PERSIST INTO SATURDAY MORNING HOWEVER MOST ACTIVITY WILL WIND DOWN JUST BEFORE SUNRISE. THERE IS A POSSIBILITY FOR LOW VISIBILITIES DUE TO MIST OR FOG ON WEDNESDAY... THURSDAY AND FRIDAY MORNING DUE TO NEAR ZERO DEW POINT DEPRESSIONS AND A FAVORABLE WIND STRUCTURE. TEMPERATURES DURING THE FORECAST PERIOD WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE WITH HIGHS IN THE LOWER 60S AND LOWS IN THE LOW TO MID 40S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1120 PM MDT SAT OCT 17 2015 VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS AS HIGH PRESSURE RESIDES OVER THE AREA. SOUTH WINDS WILL BECOME GUSTY SUNDAY AFTERNOON IN RESPONSE TO A SURFACE TROUGH OVER EASTERN COLORADO. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...TL AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1123 PM MDT SAT OCT 17 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 137 PM MDT SAT OCT 17 2015 EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS INDICATED LONGWAVE TROUGH ACROSS THE EASTERN US WITH RIDGING ACROSS THE PLAINS AND INTO THE NORTHERN ROCKIES. A CLOSED UPPER LOW IS OFF THE NORTHERN CALIFORNIA COAST. SURFACE LOW PRESSURE HAS DEVELOPED OVER NORTH CENTRAL COLORADO WITH TIGHT SOUTHERLY GRADIENT ACROSS THE PLAINS RESPONSIBLE FOR BREEZY-WINDY CONDITIONS ACROSS OUR CWA. TONIGHT-SUNDAY...CLOSED LOW OFF PACIFIC NW WILL SHIFT TOWARDS THE GREAT BASIN AND WITH A WEAKER SHORTWAVE TROUGH ROTATING AROUND NORTHERN EDGE OF UPPER RIDGE INTO THE NORTHERN PLAINS. WEAK FORCING WILL BE RESPONSIBLE FOR PERIODS OF HIGH CLOUD COVER OTHERWISE A DEEP DRY LAYER IN PLACE WILL PREVENT PRECIP DEVELOPMENT IN OUR CWA THROUGH SUNDAY AFTERNOON. LEE TROUGH WILL SHIFT EAST OVER OUR CWA WITH INCREASING WAA AND UNSEASONABLY WARM TEMPERATURES RETURNING. BASED ON MIXING HEIGHTS/TEMPS ALOFT WE SHOULD SEE HIGHS AROUND 80F WHICH IS ABOUT 15F ABOVE NORMAL SUNDAY. LOWS TONIGHT WILL BE TRICKY AS A RESULT OF A MODERATELY STRONG LLJ INCREASING BL MIXING...HOWEVER LOCATIONS IN THE NORTH AND ALONG VALLEYS SHOULD STILL BE ABLE TO DECOUPLE AND COOL TO AROUND 40F. WE MAY ALSO SEE A PERIOD OF LIGHT FOG DEVELOP ALONG VALLEYS/LOW AREAS IN OUR NW ALONG SURFACE TROUGH AS LOW LEVEL MOISTURE INCREASES. CONFIDENCE WAS TOO LOW AT THIS TIME TO INCLUDE MENTION DUE TO EXPECTED MIXING...BUT WE WILL NEED TO MONITOR. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 116 PM MDT SAT OCT 17 2015 THE CENTRAL HIGH PLAINS WILL BE UNDER SOUTHWESTERLY TO SOUTHERLY FLOW ALOFT THE ENTIRE LONG PERIOD AHEAD OF A SLOW MOVING TROUGH SET TO MOVE OUT OF THE DESERT SOUTHWEST LATE IN THE WEEK. THE LOWER LEVELS WILL GRADUALLY MOISTEN WITH THE FIRST CHANCE OF PRECIPITATION OCCURRING TUESDAY NIGHT MAINLY SOUTH OF THE INTERSTATE THEN SPREADING OVER THE REST OF THE AREA ON WEDNESDAY. RAIN CHANCES WILL CONTINUE THROUGH THE END OF THE PERIOD WITH A SERIES OF DISTURBANCES EJECTING OUT OF THE SOUTHWEST. MODELS SUGGEST AREAS OF HEAVY RAIN POSSIBLE THURSDAY THROUGH THURSDAY NIGHT AS THE MAIN LIFT MOVES OVER THE AREA. THE CLOUDS AND PRECIPITATION WILL ALSO RESULT IN COOLER TEMPERATURES FOR THE END OF THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1120 PM MDT SAT OCT 17 2015 VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS AS HIGH PRESSURE RESIDES OVER THE AREA. SOUTH WINDS WILL BECOME GUSTY SUNDAY AFTERNOON IN RESPONSE TO A SURFACE TROUGH OVER EASTERN COLORADO. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
106 AM EDT SUN OCT 18 2015 .UPDATE... ISSUED AT 106 AM EDT SUN OCT 18 2015 HIGH PRESSURE CONTINUES TO WORK INTO THE OHIO AND TENNESSEE VALLEY REGIONS THIS LATE NIGHT HOUR. THIS CANADIAN HIGH PRESSURE COUPLED WITH CLEAR SKIES HAS ALLOWED FOR DECOUPLING IN MOST VALLEY LOCATIONS. TEMPS THIS HOUR ARE ALREADY NEAR TO BELOW FREEZING IN SUSPECTED VALLEY LOCALES. THEREFORE DID DROP OFF TEMPS A BIT QUICKER THAN WHAT WAS PREVIOUSLY IN THE GRIDS...BUT FOR THE MOST PART NO MAJOR CHANGES NEEDED THIS UPDATE. UPDATE ISSUED AT 830 PM EDT SAT OCT 17 2015 HIGH PRESSURE CENTERED OVER THE MID MS VALLEY CONTINUES TO GRADUALLY SHIFT EAST INTO THE OH VALLEY REGION AND HAS USHERED IN A RELATIVELY COLD AND DRY AIRMASS FOR MID OCTOBER. A DISTURBANCE PASSING BY TO THE NORTHEAST HAS LED TO SOME STRATOCU AROUND 6KFT ACROSS THE EASTERN HALF OF THE AREA. HOWEVER...THE BACK EDGE OF THESE APPEAR TO BE OVER INDIANA...AND VALLEY LOCATIONS HAVE ALREADY DECOUPLED. THIS AND DEWPOINTS IN THE UPPER 20S TO AROUND 30 WILL SET THE STAGE FOR A HARD FREEZE IN MANY VALLEY LOCATIONS. OTHER THAN SOME SLIGHT ADJUSTMENTS TO HOURLY GRIDS...NO CHANGES WERE NEEDED ATTM. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 200 PM EDT SAT OCT 17 2015 17Z SFC ANALYSIS SHOWS HIGH PRESSURE SETTLING INTO THE MID MISSISSIPPI VALLEY WITH ITS INFLUENCE STRETCHING WELL EAST INTO THE OHIO VALLEY. THIS HAS LED TO A DRY AIR MASS OVER EASTERN KENTUCKY ALONG WITH AMPLE MORNING SUNSHINE. THESE FACTORS CONTRIBUTED TO TEMPERATURES REBOUNDING INTO THE MIDDLE AND UPPER 50S BY EARLY THIS AFTERNOON. DEVELOPING CU TO THE NORTH WILL LIMIT ADDITIONAL HEATING THERE...BUT THE SOUTH COULD RISE ANOTHER COUPLE OF DEGREES FOR HIGHS. DEWPOINTS...MEANWHILE...ARE IN THE UPPER 20S AND LOWER 30S YIELDING RH VALUES DOWN NEAR 30 PERCENT IN THE SOUTH AND CLOSER TO 40 PERCENT NORTH. WINDS HAVE BEEN GENERALLY OUT OF THE NORTH AT 5 TO 10 MPH. THE MODELS REMAIN IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST AS THEY ALL GRADUALLY MOVE A BROAD AND RELATIVELY DEEP TROUGH THE NORTHEASTERN PARTS OF NORTH AMERICA. IN THE WAKE OF THIS TROUGH DEPARTING THE OHIO VALLEY... HEIGHTS WILL RISE OVER KENTUCKY SUNDAY INTO MONDAY MORNING. GIVEN THIS AGREEMENT HAVE FOLLOWED THE WEATHER DETAILS...FEW THAT THERE ARE...FROM THE HRRR AND NAM12. DID AGAIN LEAN HEAVILY ON THE GFS BASED COOP MOS TO HELP HIT OUR VALLEY COLD SPOTS TONIGHT AND SUNDAY NIGHT. SENSIBLE WEATHER WILL FEATURE A COLD NIGHT UNDER MOSTLY CLEAR SKIES...ONCE THE NORTHERN CU FADES AROUND SUNSET. GOOD RADIATIONAL COOLING UNDER THE INVERSION WILL RESULT IN VALLEY TEMPS FALLING INTO THE MIDDLE 20S WHILE RIDGES SETTLE INTO THE LOWER 30S. THESE LOW TEMPS WILL WARRANT A FREEZE WARNING WITH THE POTENTIAL TO END THE GROWING SEASON THROUGHOUT THE CWA...IN ADDITION TO ANTICIPATED WIDESPREAD FROST. PATCHY DENSE FOG IN THE RIVER VALLEYS IS ALSO LIKELY TO FORM GIVEN WHAT WE SAW THIS MORNING. AFTER COORDINATION WITH THE UK AG WX CENTER YESTERDAY WILL CONTINUE FROST/FREEZE HEADLINES INTO MONDAY MORNING REGARDLESS OF HOW COLD IT GETS TONIGHT. FOLLOWING ANOTHER COOL DAY ON SUNDAY...CONDITIONS SIMILAR TO TONIGHT WILL SET THE STAGE FOR ANOTHER ROUND OF FREEZING TEMPERATURES IN THE VALLEYS...ESPECIALLY THE EASTERN ONES. SO... THIS NECESSITATES ANOTHER FREEZE WARNING FOR LATE SUNDAY NIGHT INTO MONDAY MORNING. AGAIN FROST WILL BE PREVALENT THROUGHOUT THE AREA ALONG WITH PATCHY FOG IN THE RIVER VALLEYS. AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR THE T AND TD GRIDS INTO SUNDAY MORNING WITH THE SUPERBLEND USED THEREAFTER. DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND SUNDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY DIFFERENCES. AS FOR POPS...AGAIN WENT ZERO THROUGH THE SHORT TERM PERIOD...IN LINE WITH ALL GUIDANCE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 200 PM EDT SAT OCT 17 2015 HIGH PRESSURE WILL DOMINATE THROUGH THE EXTENDED PORTION OF THE FORECAST...PROVIDING DRY WEATHER AND WARMING TEMPERATURES THROUGH THE FIRST HALF OF THE UPCOMING WEEK. GIVEN THE DEGREE OF DRY WEATHER...HAVE OPTED TO TREND TEMPERATURES SLIGHTLY ABOVE GUIDANCE FOR HIGHS EACH DAY...WHILE STAYING UNDER GUIDANCE FOR LOWS AT NIGHT...ESPECIALLY IN THE VALLEYS. THIS MEANS WE SHOULD SEE HIGHS AT OR ABOVE 70 FROM TUESDAY ONWARD...MAKING FOR A VERY PLEASANT STRETCH OF WEATHER. A WASHED OUT FRONTAL BOUNDARY WILL DROP SOUTH ACROSS THE AREA ON THURSDAY...BUT THE FEATURE CONTINUES TO TREND WEAKER...AND WILL LIKELY HAVE MINIMAL IMPACT ON THE WEATHER ACROSS EASTERN KENTUCKY. HIGH PRESSURE WILL THEN QUICKLY REBUILD AS WE HEAD INTO NEXT WEEKEND...WITH THE MILD WEATHER CONTINUING INTO NEXT WEEKEND. MAIN WEATHER IMPACT WE WILL SEE THIS WEEK...IS THE CONTINUATION OF THE DRY CONDITIONS WITH AFTERNOON RELATIVE HUMIDITIES FALLING TO BETWEEN 20 AND 30 PERCENT. ITS LIKELY A FEW RH READINGS INTO THE TEENS MAY BE POSSIBLE. WILL CONTINUE TO HIGHLIGHT THE LOW AFTERNOON RELATIVE HUMIDITIES IN THE FIRE WEATHER FORECAST. FORTUNATELY...THE GRADIENT SHOULD REMAIN WEAK ENOUGH TO LIMIT OVERALL WIND POTENTIAL THROUGH THE WEEK...KEEPING WINDS UNDER 10 MPH. CONTINUED TO RUN DEWPOINTS UNDER GUIDANCE EACH AFTERNOON AS MODELS TYPICALLY DON`T HANDLE DEWPOINTS WELL IN THE AFTERNOON WITH GOOD MIXING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 100 AM EDT SUN OCT 18 2015 HIGH PRESSURE CONTINUES TO KEEP WEATHER QUITE AND THEREFORE VFR TAFS. WHILE THERE COULD BE SOME PATCHY FOG IN SOME VALLEY LOCATIONS...HOWEVER TAF SITES ARE EXPECTED TO REMAIN P6SM. WINDS WILL ALSO REMAIN LIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...DJ SHORT TERM...GREIF LONG TERM...KAS AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
100 AM EDT SUN OCT 18 2015 .UPDATE... ISSUED AT 830 PM EDT SAT OCT 17 2015 HIGH PRESSURE CENTERED OVER THE MID MS VALLEY CONTINUES TO GRADUALLY SHIFT EAST INTO THE OH VALLEY REGION AND HAS USHERED IN A RELATIVELY COLD AND DRY AIRMASS FOR MID OCTOBER. A DISTURBANCE PASSING BY TO THE NORTHEAST HAS LED TO SOME STRATOCU AROUND 6KFT ACROSS THE EASTERN HALF OF THE AREA. HOWEVER...THE BACK EDGE OF THESE APPEAR TO BE OVER INDIANA...AND VALLEY LOCATIONS HAVE ALREADY DECOUPLED. THIS AND DEWPOINTS IN THE UPPER 20S TO AROUND 30 WILL SET THE STAGE FOR A HARD FREEZE IN MANY VALLEY LOCATIONS. OTHER THAN SOME SLIGHT ADJUSTMENTS TO HOURLY GRIDS...NO CHANGES WERE NEEDED ATTM. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 200 PM EDT SAT OCT 17 2015 17Z SFC ANALYSIS SHOWS HIGH PRESSURE SETTLING INTO THE MID MISSISSIPPI VALLEY WITH ITS INFLUENCE STRETCHING WELL EAST INTO THE OHIO VALLEY. THIS HAS LED TO A DRY AIR MASS OVER EASTERN KENTUCKY ALONG WITH AMPLE MORNING SUNSHINE. THESE FACTORS CONTRIBUTED TO TEMPERATURES REBOUNDING INTO THE MIDDLE AND UPPER 50S BY EARLY THIS AFTERNOON. DEVELOPING CU TO THE NORTH WILL LIMIT ADDITIONAL HEATING THERE...BUT THE SOUTH COULD RISE ANOTHER COUPLE OF DEGREES FOR HIGHS. DEWPOINTS...MEANWHILE...ARE IN THE UPPER 20S AND LOWER 30S YIELDING RH VALUES DOWN NEAR 30 PERCENT IN THE SOUTH AND CLOSER TO 40 PERCENT NORTH. WINDS HAVE BEEN GENERALLY OUT OF THE NORTH AT 5 TO 10 MPH. THE MODELS REMAIN IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST AS THEY ALL GRADUALLY MOVE A BROAD AND RELATIVELY DEEP TROUGH THE NORTHEASTERN PARTS OF NORTH AMERICA. IN THE WAKE OF THIS TROUGH DEPARTING THE OHIO VALLEY... HEIGHTS WILL RISE OVER KENTUCKY SUNDAY INTO MONDAY MORNING. GIVEN THIS AGREEMENT HAVE FOLLOWED THE WEATHER DETAILS...FEW THAT THERE ARE...FROM THE HRRR AND NAM12. DID AGAIN LEAN HEAVILY ON THE GFS BASED COOP MOS TO HELP HIT OUR VALLEY COLD SPOTS TONIGHT AND SUNDAY NIGHT. SENSIBLE WEATHER WILL FEATURE A COLD NIGHT UNDER MOSTLY CLEAR SKIES...ONCE THE NORTHERN CU FADES AROUND SUNSET. GOOD RADIATIONAL COOLING UNDER THE INVERSION WILL RESULT IN VALLEY TEMPS FALLING INTO THE MIDDLE 20S WHILE RIDGES SETTLE INTO THE LOWER 30S. THESE LOW TEMPS WILL WARRANT A FREEZE WARNING WITH THE POTENTIAL TO END THE GROWING SEASON THROUGHOUT THE CWA...IN ADDITION TO ANTICIPATED WIDESPREAD FROST. PATCHY DENSE FOG IN THE RIVER VALLEYS IS ALSO LIKELY TO FORM GIVEN WHAT WE SAW THIS MORNING. AFTER COORDINATION WITH THE UK AG WX CENTER YESTERDAY WILL CONTINUE FROST/FREEZE HEADLINES INTO MONDAY MORNING REGARDLESS OF HOW COLD IT GETS TONIGHT. FOLLOWING ANOTHER COOL DAY ON SUNDAY...CONDITIONS SIMILAR TO TONIGHT WILL SET THE STAGE FOR ANOTHER ROUND OF FREEZING TEMPERATURES IN THE VALLEYS...ESPECIALLY THE EASTERN ONES. SO... THIS NECESSITATES ANOTHER FREEZE WARNING FOR LATE SUNDAY NIGHT INTO MONDAY MORNING. AGAIN FROST WILL BE PREVALENT THROUGHOUT THE AREA ALONG WITH PATCHY FOG IN THE RIVER VALLEYS. AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR THE T AND TD GRIDS INTO SUNDAY MORNING WITH THE SUPERBLEND USED THEREAFTER. DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND SUNDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY DIFFERENCES. AS FOR POPS...AGAIN WENT ZERO THROUGH THE SHORT TERM PERIOD...IN LINE WITH ALL GUIDANCE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 200 PM EDT SAT OCT 17 2015 HIGH PRESSURE WILL DOMINATE THROUGH THE EXTENDED PORTION OF THE FORECAST...PROVIDING DRY WEATHER AND WARMING TEMPERATURES THROUGH THE FIRST HALF OF THE UPCOMING WEEK. GIVEN THE DEGREE OF DRY WEATHER...HAVE OPTED TO TREND TEMPERATURES SLIGHTLY ABOVE GUIDANCE FOR HIGHS EACH DAY...WHILE STAYING UNDER GUIDANCE FOR LOWS AT NIGHT...ESPECIALLY IN THE VALLEYS. THIS MEANS WE SHOULD SEE HIGHS AT OR ABOVE 70 FROM TUESDAY ONWARD...MAKING FOR A VERY PLEASANT STRETCH OF WEATHER. A WASHED OUT FRONTAL BOUNDARY WILL DROP SOUTH ACROSS THE AREA ON THURSDAY...BUT THE FEATURE CONTINUES TO TREND WEAKER...AND WILL LIKELY HAVE MINIMAL IMPACT ON THE WEATHER ACROSS EASTERN KENTUCKY. HIGH PRESSURE WILL THEN QUICKLY REBUILD AS WE HEAD INTO NEXT WEEKEND...WITH THE MILD WEATHER CONTINUING INTO NEXT WEEKEND. MAIN WEATHER IMPACT WE WILL SEE THIS WEEK...IS THE CONTINUATION OF THE DRY CONDITIONS WITH AFTERNOON RELATIVE HUMIDITIES FALLING TO BETWEEN 20 AND 30 PERCENT. ITS LIKELY A FEW RH READINGS INTO THE TEENS MAY BE POSSIBLE. WILL CONTINUE TO HIGHLIGHT THE LOW AFTERNOON RELATIVE HUMIDITIES IN THE FIRE WEATHER FORECAST. FORTUNATELY...THE GRADIENT SHOULD REMAIN WEAK ENOUGH TO LIMIT OVERALL WIND POTENTIAL THROUGH THE WEEK...KEEPING WINDS UNDER 10 MPH. CONTINUED TO RUN DEWPOINTS UNDER GUIDANCE EACH AFTERNOON AS MODELS TYPICALLY DON`T HANDLE DEWPOINTS WELL IN THE AFTERNOON WITH GOOD MIXING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 100 AM EDT SUN OCT 18 2015 HIGH PRESSURE CONTINUES TO KEEP WEATHER QUITE AND THEREFORE VFR TAFS. WHILE THERE COULD BE SOME PATCHY FOG IN SOME VALLEY LOCATIONS...HOWEVER TAF SITES ARE EXPECTED TO REMAIN P6SM. WINDS WILL ALSO REMAIN LIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...KAS AVIATION...DJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
523 AM EDT SUN OCT 18 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 523 AM EDT SUN OCT 18 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A FAIRLY DEEP TROF OVER ERN N AMERICA AND A RIDGE TO THE W WITH AXIS OVER THE HIGH PLAINS. BTWN THESE FEATURES...NW FLOW CONTINUES OVER THE UPPER GREAT LAKES EARLY THIS MORNING...BUT HEIGHTS ARE RISING AS THE RIDGE AND TROF ARE SHIFTING E. LES CONTINUES INTO THE ERN FCST AREA...E OF MARQUETTE. LES WAS MDT TO HVY AT TIMES IN ALGER AND NRN SCHOOLCRAFT COUNTIES FOR SEVERAL HRS DURING THE NIGHT...BUT LES IS NOW SHOWING A NOTABLE DIMINISHING TREND UNDER FALLING SUBSIDENCE INVERSION. WITH THE START OF WAA...LAKE EFFECT CLOUDS OFF WRN LAKE SUPERIOR ARE DECREASING. SFC HIGH PRES RIDGE AXIS NOW JUST W OF LAKE SUPERIOR IS FCST TO SHIFT QUICKLY E ACROSS THE FCST AREA TODAY. ALONG WITH THE FALLING SUBSIDENCE INVERSION...LES INTO THE ERN FCST WILL END THIS MORNING. ONLY MINOR ADDITIONAL SNOW ACCUMULATIONS UNDER AN INCH WILL OCCUR EARLY THIS MORNING. IF THERE ARE ANY LINGERING CLOUDS OVER THE W AFTER SUNRISE...THEY WILL QUICKLY CLEAR OUT THIS MORNING. SKIES WILL ALSO BECOME MOSTLY SUNNY E THIS AFTN. HIGHS TODAY WILL TOP OUT IN THE 40S E TO AS HIGH AS THE LOWER 50S W WHERE WAA AND MORE SUN WILL AID WARMING. PRES GRADIENT WILL QUICKLY TIGHTEN AFTER PASSAGE OF THE HIGH PRES RIDGE AXIS AS A RAPIDLY DEEPENING SFC LOW TRACKING E TO HUDSON BAY PUSHES AN ASSOCIATED TROF INTO THE WRN PLAINS. EXPECT S WINDS TO ALREADY BEGIN TO SHOW SOME GUSTINESS DURING THE LATTER PORTION OF THE AFTN OVER THE W HALF. WINDS WILL THEN BE THE MAIN STORY TONIGHT. A DEEP SFC LOW OVER HUDSON BAY...DROPPING TO A PRES OF AROUND 28.7 INCHES...WILL DRIVE ASSOCIATED SFC TROF INTO MN. A 50+KT LOW-LEVEL JET WILL SHIFT INTO UPPER MI DURING THE NIGHT. WHILE WAA AND NOCTURNAL COOLING WILL RESULT IN CONSIDERABLE STABILITY PREVENTING ACCESS TO THE PEAK LOW- LEVEL WINDS...MAX PRES FALLS OF AROUND 6MB/3HR SHIFTING ACROSS NRN ONTARIO WILL AID AN INCREASE IN SFC WINDS/GUSTINESS...MAINLY IN THE HIGH TERRAIN AND ESPECIALLY IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR AND ALONG NRN LAKE MI E OF ESCANABA. COULD BECOME FAIRLY WINDY AT LEAST FOR A FEW HRS DURING THE TIME THAT THE ISALLOBARIC WIND COMPONENT IS MAXIMIZED. WINDS WILL KEEP MIN TEMPS UP IN THE 30S TO LWR 40S TONIGHT. INTERIOR SHELTERED LOCATIONS IN THE CNTRL AND E MAY FALL TO THE LWR 30S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 443 AM EDT SUN OCT 18 2015 TEMPERATURES THROUGH THE EXTENDED WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH A COUPLE CHANCES FOR RAINFALL. MONDAY THROUGH TUESDAY...THE BROAD SURFACE RIDGE OVER THE MID ATLANTIC STATES MONDAY WILL CONTINUE TO SLIDE TO THE SOUTHEAST. AS THIS HAPPENS...A FAIRLY STRONG LOW PRESSURE SYSTEM OVER HUDSON BAY WILL SLIDE INTO NORTHWEST QUEBEC. THERE WILL BE A FAIRLY STRONG PRESSURE GRADIENT BETWEEN THE TWO SYSTEMS ALONG WITH A 40 TO 50 KNOT LLJ...MAINLY OVER EASTERN LAKE SUPERIOR AND NORTHERN LAKE MICHIGAN MONDAY MORNING BEFORE THE GRADIENT SLOWLY RELAXES DURING THE AFTERNOON HOURS. THIS ALONG WITH DECENT MIXING IN THE LOWER LEVEL WILL ALLOW FOR GUSTY SOUTHWEST WINDS...INCLUDING GALES ON LAKE SUPERIOR AND LAKE MICHIGAN. ADDITIONALLY...THE LOW PRESSURE SYSTEM HAS A WEAK TRAILING COLD FRONT STRETCHING FROM HUDSON BAY TO NEAR THE ARROWHEAD OF MINNESOTA MONDAY MORNING. THIS FRONT WILL BECOME MORE ENE TO WSW ORIENTED ACROSS THE AREA BEFORE QUICKLY SLIDING TO THE SOUTH AND EAST OF THE AREA MONDAY NIGHT. THERE MAY BE A FEW RAIN SHOWERS ALONG THE COLD FRONT BUT MOISTURE LOOKS TO BE FAIRLY LIMITED AT THIS POINT AND FORCING LOOKS TO BE FAIRLY WEAK. HAVE ONLY KEPT ISOLATED RAIN SHOWERS IN THE FORECAST FOR MONDAY. BEHIND THE COLD FRONT...A SURFACE RIDGE...ZONAL TO SLIGHT UPPER LEVEL 500MB RIDGING AND DRY AIR WILL BUILD INTO THE AREA LATE MONDAY NIGHT AND LINGER THROUGH MUCH OF THE DAY TUESDAY BRINGING WARMER TEMPERATURES AND AN END TO ANY ISOLATED SHOWERS THAT MAY DEVELOP MONDAY. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AS THE AFOREMENTIONED HIGH PRESSURE SYSTEM SLIDES TO THE EAST OF THE AREA...A FAIRLY STRONG SHORTWAVE AND SURFACE LOW DEVELOPING OVER SOUTHERN CANADA...WILL BEGIN TO SLIDE EASTWARD TOWARD THE AREA TUESDAY NIGHT. IT LOOKS LIKE THERE WILL BE ANOTHER...WEAKER...SHORTWAVE THAT SLIDES IN AHEAD OF THE MAIN SHORTWAVE WHICH COULD HELP TO KICK UP SCATTERED RAIN SHOWERS TUESDAY NIGHT...HOWEVER...THE BETTER FORCING WILL BE WITH THE MUCH STRONGER SHORTWAVE PROGGED TO SLIDE ACROSS LAKE SUPERIOR AND MUCH OF THE U.P. WEDNESDAY INTO WEDNESDAY NIGHT. THURSDAY THROUGH THE EXTENDED...CONTINUED TO USE A CONSENSUS OF THE MODELS THROUGH THIS TIME PERIOD. THE GENERAL TREND IS FOR A SURFACE RIDGE AND ASSOCIATED UPPER LEVEL RIDGE TO BUILD INTO THE AREA THURSDAY AND LINGER THROUGH THURSDAY NIGHT. THERE ARE SOME MODEL DISAGREEMENTS BEYOND THAT. FRIDAY THE NEXT LOW PRESSURE SYSTEM...DEVELOPING OVER THE PLAINS IS PROGGED TO PROGRESS SLOWLY TOWARD THE EAST. THE GFS...AS IS TYPICAL FOR THIS TIME OF YEAR...RUSHES THE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT EASTWARD. THIS SOLUTION WOULD BRING PRECIPITATION INTO THE U.P. FRIDAY AND RUSH IT OUT OF THE AREA BY SATURDAY MORNING. THE EC...IS LESS PROGRESSIVE WITH THIS SYSTEM...WHICH KEEP THE HIGH PRESSURE IN PLACE A BIT LONGER...KEEPING CONDITIONS DRY THROUGH FRIDAY AFTERNOON. THE RAIN SHOWERS WITH THE EC SOLUTION WOULD THEN LINGER THROUGH SATURDAY. THE REDUCED CONFIDENCE IN ANY ONE PARTICULAR MODEL HAS LEANED THE FORECAST MORE TOWARD THE CONSENSUS OF THE MODELS WHICH KEEPS CHANCE POPS IN THE FORECAST FRIDAY THROUGH SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 137 AM EDT SUN OCT 18 2015 LOOK FOR VFR CONDITIONS TO PREVAIL AT KIWD/KCMX/KSAW THROUGH THE FORECAST PERIOD AS HIGH PRESSURE BUILDS INTO THE REGION OVERNIGHT. LINGERING CLOUD COVER ON NW FLOW WILL GRADUALLY ERODE AWAY AT KCMX AND KSAW OVERNIGHT/EARLY MORNING AS RIDGE BUILDS IN...RESULTING IN MOSTLY CLEAR SKIES THROUGH THE DAYLIGHT HOURS. LIGHT WINDS WILL GRADUALLY INCREASE AS THE RIDGE SHIFTS EAST...WITH GUSTS TO 15 TO 20 KTS POSSIBLE FROM MID/LATE AFTERNOON INTO THE EVENING HOURS. WITH WINDS INCREASING ALOFT...THERE IS A POTENTIAL FOR LLWS THIS EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 523 AM EDT SUN OCT 18 2015 HIGH PRES RIDGE WILL QUICKLY SHIFT ACROSS LAKE SUPERIOR TODAY... RESULTING IN A BRIEF PERIOD OF LIGHT WINDS. ALREADY IN THE AFTN... TIGHTENING PRES GRADIENT BEHIND THE RIDGE WILL LEAD TO INCREASING S WINDS...GUSTING TO 20-25KT BY LATE AFTN. WINDS INCREASE FURTHER TONIGHT AS A DEEP LOW TRACKS E OVER HUDSON BAY. WITH AN AREA OF MAX PRES FALLS PASSING N OF THE LAKE...S TO SW WINDS WILL LIKELY REACH GALE FORCE...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW...AND OVER THE EASTERN PART OF THE LAKE WHERE THIS TYPE OF PATTERN TYPICALLY PRODUCES THE STRONGEST WINDS. THE HIGHEST OBS PLATFORMS WILL PROBABLY SEE WIND GUSTS IN EXCESS OF 40KT FOR A TIME. WINDS WILL DIMINISH TO UNDER 25KT W TO E ON MON. AFTER A TROF PASSES LATE MON AFTN AND EVENING...N TO NE WINDS WILL INCREASE TO 20-30KT OVER MUCH OF THE LAKE AHEAD OF HIGH PRES THAT WILL BUILD SE INTO NRN ONTARIO TUE. WINDS WILL THEN VEER TO THE E-SE TUE NIGHT/WED AS THE HIGH MOVES INTO QUEBEC AND A LOW PRES TROF APPROACHES. AFTER THE TROF PASSES...WINDS WILL FINALLY DIMINISH LATER THU WHEN HIGH PRES BUILDS INTO THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 11 AM EDT MONDAY FOR LSZ266-267. GALE WARNING FROM 11 PM THIS EVENING TO 8 AM EDT MONDAY FOR LSZ263-264. LAKE MICHIGAN... GALE WARNING FROM 1 AM TO 2 PM EDT MONDAY FOR LMZ221-248-250. && $$ SHORT TERM...ROLFSON LONG TERM...KEC AVIATION...RJT MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
329 AM CDT SUN OCT 18 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT SUN OCT 18 2015 BIGGEST CONCERN IN THE SHORT TERM DEALS WITH FIRE WEATHER TODAY...WITH WEST CENTRAL INTO SOUTH CENTRAL MN EXPECTED TO FLIRT WITH RED FLAG WARNING CRITERIA. SFC RIDGE TONIGHT IS CENTERED OVER WI...WITH SE RETURN FLOW QUICKLY BECOMING ESTABLISHED ACROSS MN. THE MAIN THEME FOR TODAY WILL BE STRONG WAA...AS H85 TEMPS WILL BE WARMING ABOUT 10C OVER WHAT WE SAW YESTERDAY. THERE IS GOOD VISUAL EVIDENCE OF SAID WARM ADVECTION IN THE FORM OF A BANK OF 6K-8K FT CLOUDS THAT HAVE FORMED OVER SRN MN THIS MORNING. RAP 750MB RH ALONG WITH THE CLOUD FORECAST FROM THE HRRR EVENTUALLY LATCHED ON TO THIS CLOUD COVER AND FOLLOWED THESE MODEL FEATURES TO PUSH THAT AREA OF CLOUDS EAST ACROSS SRN MN INTO WI THIS MORNING. BY THE AFTERNOON...THESE CLOUDS WILL BE EAST OF THE MPX CWA AND OUR SKIES WILL REMAIN MAINLY CLEAR UNTIL UPPER LEVEL CLOUDS CURRENTLY OVER CO/WY GET HERE TONIGHT. THOUGH H85 TEMPS ARE WARMING 10C...WE WILL NOT BE MIXING THAT DEEP...WITH NAM/RAP SOUNDINGS SHOWING THE BOUNDARY LAYER BUILDING TO ABOUT 900 MB. MIXING TO THIS LEVEL PRODUCED HIGHS SIMILAR TO WHAT WE HAD GOING...WITH UPPER 60S IN WRN MN AND UPPER 50S IN WRN WI. THESE WARM TEMPERATURES COMBINED WITH DEWPS THIS MORNING IN THE 20S WOULD PRODUCE HUMIDITIES UNDER 25 PERCENT...BUT THE GFS/NAM BOTH SUPPORT DEEP ENOUGH MOISTURE ARRIVING WITH THE SE WINDS TO HELP PUSH DEWPS THIS AFTERNOON UP INTO THE LOWER/MIDDLE 30S IN SOUTHERN/WESTERN MN...WHICH IS JUST ENOUGH TO KEEP AFTERNOON HUMIDITIES ABOUT THE 25 PERCENT THRESHOLD FOR A RFW. STILL...WITH HUMIDITIES LIKELY DROPPING UNDER 30 PERCENT ALONG WITH SE WINDS INCREASING TO BETWEEN 20 AND 25 MPH WITH GUSTS TO AROUND 30 MPH...WILL CONTINUE TO HEADLINE THE INCREASED FIRE WEATHER THREAT IN THE FIRE WEATHER PLANNING FORECAST. TONIGHT...SHORTWAVE ENERGY CURRENTLY OVER CO/WY WILL FLATTEN OUT THE UPPER RIDGE MOVING OVERHEAD TODAY AND BRING A SLUG OF UPPER LEVEL MOISTURE WITH AS WELL. HOWEVER...RH TIME-HEIGHT CROSS SECTIONS SHOW THIS MOISTURE ONLY GETTING DOWN TO ABOUT 15K FT...SO NOT CONCERNED ABOUT ANY PRECIP. HOWEVER...THESE CLOUDS ALONG WITH SOUTHERLY WINDS REMAINING UP OVERNIGHT WILL RESULT IN A VERY MILD NIGHT TONIGHT...WITH MUCH OF THE MN CWA SOUTH OF I-94 STAYING UP IN THE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN OCT 18 2015 THE LONG TERM STILL LOOKS TO START OUT ON A WARM NOTE MONDAY WITH HIGHS AROUND 15 TO 20 DEGREES ABOVE CLIMATOLOGICAL NORMALS. MEANWHILE...PRECIPITATION CHANCES CONTINUE TO WANE UNTIL CLOSER TO THE END OF THE WEEK. THE SURFACE COLD FRONT STILL LOOKS TO BE ON OUR WESTERN DOORSTEP AT DAYBREAK MONDAY. FAVORABLE SOUTHWEST FLOW FOR WARMING WILL ENSUE THROUGH MIDDAY ACROSS MUCH OF CENTRAL AND SOUTH CENTRAL MN. H85 TEMPS IN THE UPPER TEENS /CELSIUS/ SHOULD YIELD UPPER 70S TO NEAR 80 DEGREES OVER SOUTHWEST/SOUTH CENTRAL MN...WITH LOW/MID 70S ACROSS THE REMAINDER OF THE AREA. AT THIS POINT THE PROGGED MOISTURE IS HARDLY SUFFICIENT TO GENERATE MUCH MORE THAN BROKEN MID LEVEL CLOUD COVER ACROSS CENTRAL MN/WI...WITH VIRTUALLY NO FORCING TO MENTION. HAVE THEREFORE REMOVED POPS FOR MONDAY. TUESDAY AN INVERTED TROUGH NOSES INTO THE REGION...ALTHOUGH MODELS ARE STILL ALL OVER THE MAP WITH REGARD TO POSITIONING. TWO AREAS OF PRECIPITATION LOOK TO UNFOLD...WITH MODELS HINTING THE FORECAST AREA COULD LARGELY BE PLACED BETWEEN SAID AREAS. HAVE INCLUDED 20-30 POPS FOR TUESDAY/WEDNESDAY...BUT ACTIVITY LOOKS AS IF IT WOULD BE SCATTERED AT BEST WITH LOW PRECIP AMOUNTS. WEDNESDAY NIGHT AND THURSDAY FLEETING SURFACE HIGH PRESSURE MOVES ACROSS THE AREA...BUT THEN A STRONGER TROUGH WITH A NICE FETCH OF MOISTURE ADVECTION LIFTS INTO THE AREA FOR FRIDAY. HAVE INCLUDED 40-50 POPS FOR FRIDAY AND FRIDAY NIGHT...DRYING OUT FOR SATURDAY. HIGH TEMPERATURES FROM TUESDAY THROUGH THE LONG TERM FORECAST PERIOD LOOK TO RUN AROUND 5 TO 10 DEGREES ABOVE NORMAL...WITH LOWS EVEN WARMER IN THE 10 TO 15 DEGREES ABOVE NORMAL RANGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1249 AM CDT SUN OCT 18 2015 DRY SFC HIGH WILL DOMINATE THIS TAF PERIOD. SE RETURN FLOW ALREADY SETUP OUT IN WRN MN AND WILL WORK INTO WRN WI SHORTLY AFTER SUNRISE. STRONG PRESSURE GRADIENT WILL SETUP AND FORECAST SOUNDINGS FULLY SUPPORT LAV GUIDANCE WINDS...SO FOLLOWED THOSE NUMBERS FOR RAMPING UP WINDS LATER TODAY. RAP 750MB RH HAS A GOOD HANDLE ON CLOUDS EXPANDING ACROSS SRN MN AT AROUND 7K FT. THIS AREA OF WARM ADVECTIVE CLOUDS WILL WORK EAST THROUGH THE MORNING...POSSIBLY CLIPPING MSP/EAU. KMSP...ONLY QUESTION MARK FOR THIS TAF IS DO 7K-8K FT CLOUDS SW OF MSP REACH THE FIELD. KEPT THEM OUT...BUT RAP 750MB RH WOULD SAY WE SEE SOME CLOUDS AT THIS LEVEL BETWEEN 8Z AND 18Z. /OUTLOOK FOR KMSP/ MON...VFR. LLWS PSBL IN MRNG. WINDS SW 15G25KTS TUE...VFR. WINDS NE/E 5-10KTS. WED...VFR. CHC MRNG SHRA. WINDS E BCMG NW 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...LS AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1250 AM CDT SUN OCT 18 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 330 PM CDT SAT OCT 17 2015 DRY...COOL AND QUIET WEATHER IS EXPECTED TONIGHT...BUT THERE IS CHANGE AFOOT. RIDGE OF HIGH PRESSURE EXTENDING FROM CENTRAL IOWA TO SOUTHEASTERN MANITOBA WILL CROSS MINNESOTA THIS EVENING...AND REACH WESTERN WISCONSIN LATER THIS EVENING. RETURN FLOW HAS ALREADY STARTED IN FAR WESTERN MN...AND THE ENTIRE AREA WILL HAVE SSE WINDS TOMORROW. WITH LOW PRESSURE EXPECTED TO STILL BE IN THE NORTHERN HIGH PLAINS...A DECENT GRADIENT WILL DEVELOP. WINDS IN WESTERN MN SHOULD REV UP AND PRODUCE GUSTS OF 25-30 KNOTS FROM WEST CENTRAL TO SOUTH CENTRAL MN. RIGHT NOW IT LOOKS LIKE HIGHS WILL BE IN THE LOWER TO MID 60S. DEW POINTS ARE THE MAIN CONCERN AT THIS TIME IN TERMS OF FIRE WEATHER. LOW LEVEL MOISTURE IS SLIGHTLY GREATER TO OUR SOUTHWEST...AND THEREFORE THINK DEW POINTS IN OUR WESTERN COUNTIES TOMORROW WILL RISE A TAD INTO THE LOWER 30S...RESULTING IN MINIMUM HUMIDITIES ON THE ORDER OF 28-32 PERCENT. IF THIS CHANGES VERY MUCH... THEN FIRE WEATHER HIGHLIGHTS MAY BE IN ORDER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 PM CDT SAT OCT 17 2015 THE MAIN CONCERNS IN THE LONG TERM REMAIN HOW WARM IT WILL GET MONDAY AFTERNOON AND THE OVERALL DEVELOPMENT/MOVEMENT OF NEXT WAVE FOR TUE THROUGH WED MORNING...AND AGAIN LATE IN THE WEEK INTO THE WEEKEND. STILL HAVE A DECENT THERMAL RIDGE AHEAD OF THE FRONT ON MONDAY AFTERNOON. QUESTION REMAINS HOW MUCH CLOUD COVER WE WILL WORK OVER THE REGION WITH THE SYSTEM. WILL LIKELY SEE SOME MID/HIGH LEVEL CLOUDS MOVE ACROSS THE AREA...THICKER TO THE EAST. MAINTAINED A SMALL CHANCE FOR SHOWERS INTO THE NORTHEAST CWA WHERE LIMITED FORCING IS LOCATED. THE GFS IS CONSISTENT WITH THE MID/UPPER 70S TO THE SOUTHWEST AND SOME UPPER 60S TO LOWER 70S ELSEWHERE. SOUTHWEST FLOW WILL REMAIN STRONG AHEAD OF THE FRONT AND WITH DEWPOINTS REMAINING FAIRLY DRY...WE WILL LIKELY SEE RELATIVE HUMIDITY DROP OFF TO 25 TO 30 PERCENT AGAIN MONDAY AFTERNOON OVER MAINLY SOUTH CENTRAL MINNESOTA. MENTIONED THIS CONCERN IN THE FIRE WEATHER FORECAST. THE FRONT DROPS SOUTH OF THE AREA INTO MONDAY NIGHT AND UPPER LEVEL FLOW DOES MERGE A BIT OVER THE AREA TUESDAY-WEDNESDAY. WILL CONTINUE A CHANCE FOR -SHRA WITH THIS AS IT MOVES THROUGH. MOISTURE WILL BE LIMITED HOWEVER. ABOVE NORMAL TEMPERATURES REMAIN OVER THE AREA THROUGH THE REMAINDER OF THE FORECAST. THE NEXT BEST SHOT FOR SHOWERS ARRIVES LATE IN THE WEEK AND LINGERING INTO SATURDAY. WE MAY SEE A LITTLE DEEPER MOISTURE RETURN AS FLOW BECOMES MORE SOUTHWEST ALOFT AND PWATS INCREASE TO NEAR 1.4 INCHES BY SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1249 AM CDT SUN OCT 18 2015 DRY SFC HIGH WILL DOMINATE THIS TAF PERIOD. SE RETURN FLOW ALREADY SETUP OUT IN WRN MN AND WILL WORK INTO WRN WI SHORTLY AFTER SUNRISE. STRONG PRESSURE GRADIENT WILL SETUP AND FORECAST SOUNDINGS FULLY SUPPORT LAV GUIDANCE WINDS...SO FOLLOWED THOSE NUMBERS FOR RAMPING UP WINDS LATER TODAY. RAP 750MB RH HAS A GOOD HANDEL ON CLOUDS EXPANDING ACROSS SRN MN AT AROUND 7K FT. THIS AREA OF WARM ADVECTIVE CLOUDS WILL WORK EAST THROUGH THE MORNING...POSSIBLY CLIPPING MSP/EAU. KMSP...ONLY QUESTION MARK FOR THIS TAF IS DO 7K-8K FT CLOUDS SW OF MSP REACH THE FIELD. KEPT THEM OUT...BUT RAP 750MB RH WOULD SAY WE SEE SOME CLOUDS AT THIS LEVEL BETWEEN 8Z AND 18Z. /OUTLOOK FOR KMSP/ MON...VFR. LLWS PSBL IN MRNG. WINDS SW 15G25KTS TUE...VFR. WINDS NE/E 5-10KTS. WED...VFR. CHC MRNG SHRA. WINDS E BCMG NW 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...TDK LONG TERM...DWE AVIATION...MPG
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1253 AM PDT SUN OCT 18 2015 .SYNOPSIS...A BROAD LOW PRESSURE SYSTEM MOVING ACROSS CALIFORNIA AND NEVADA TONIGHT AND SUNDAY WILL BRING INCREASING COVERAGE OF SHOWERS AND SCATTERED THUNDERSTORMS TO MUCH OF THE REGION SUNDAY MORNING THROUGH SUNDAY AFTERNOON. ADDITIONAL UPPER LEVEL DISTURBANCES WILL CONTINUE TO PROVIDE UNSETTLED AND COOL CONDITIONS INTO THE MIDDLE OF NEXT WEEK. && .UPDATE...1250 AM...QUICK UPDATE TO INCREASE PRECIP CHANCES OVER SOUTHERN SAN BERNARDINO AND MOHAVE COUNTIES (INCLUDING LAKE HAVASU) WHERE A COUPLE ISOLATED STORMS HAVE DEVELOPED. THE REST OF THE FORECAST REMAINS ON TRACK EARLY THIS MORNING. ISOLATED-SCATTERED STORMS HAVE BEGUN TO DEVELOP AS EXPECTED ACROSS WESTERN SAN BERNARDINO AND EASTERN INYO COUNTIES...TRACKING NORTHEAST. THESE STORMS ARE BEING MONITORED CLOSELY FOR FLASH FLOODING. && .PREV UPDATE...855 PM PDT SAT OCT 17 2015...MOST OF THE AREA IS FREE OF CONVECTION AT THIS HOUR...HOWEVER SHORT RANGE GUIDANCE SUGGEST THAT THIS WILL CHANGE OVER THE NEXT FEW HOURS. THE HRRR AND HRRRX HAVE BEEN FAIRLY CONSISTENT SHOWING AN UPTICK IN ACTIVITY ALONG AND WEST OF A LINE FROM BARSTOW TO TONOPAH BETWEEN 04Z AND 06Z THIS EVENING. THIS WILL BE IN RESPONSE TO UPPER LEVEL FORCING ENCOUNTERING AN UNSTABLE AIRMASS. EXPECT MUCH OF THIS ACTIVITY TO CONGEAL INTO A NORTH-SOUTH BAND OF SHOWERS WITH EMBEDDED THUNDERSTORMS BETWEEN 06Z AND 12Z AND SLOWLY PROGRESS EAST. BASED ON MODEL CONSENSUS...BY 12Z THIS LINE SHOULD STRETCH FROM ROUGHLY BAKER TO RACHEL. THROUGH SUNDAY THIS LINE WILL CONTINUE TO PUSH EAST...GRADUALLY PIVOTING TO A SSW-NNE ORIENTATION. AS THIS OCCURS THUNDERSTORM COVERAGE AND INTENSITY BOTH IN AND AHEAD OF THE BAND (MOHAVE AND EASTERN CLARK COUNTIES) IS LIKELY TO INCREASE WITH THE ADDITION OF DAYTIME HEATING. CURRENT GUIDANCE SUGGESTS THE MOST LIKELY TIMING FOR THIS BAND TO CROSS THE LAS VEGAS VALLEY WOULD BE FROM 19Z-23Z (12PM-4PM). FORECAST HAS BEEN TWEAKED TO ACCOUNT FOR THE LATEST MODEL ANALYSIS THROUGH SUNDAY. CURRENT FLASH FLOOD WATCH PLACEMENT AND TIMING APPEARS TO BE GOOD AND NO CHANGES TO THAT PRODUCT ARE EXPECTED AT THIS TIME. && .AVIATION...FOR MCCARRAN...WINDS LIKELY TO REMAIN LIGHT AND VARIABLE UNDER 8 KTS OVERNIGHT...THEN INCREASE TO 12-16KTS WITH GUSTS TO 25 KTS FROM THE SOUTH-SOUTHWEST AFTER 18Z. SHOWER AND THUNDERSTORM ACTIVITY WILL BE FAIRLY LIMITED THE REMAINDER OF THE NIGHT...BUT CANNOT BE COMPLETELY RULED OUT. CIGS OF 4-6K NEAR ANY SHOWER ACTIVITY TONIGHT...OTHERWISE SCT-BKN CLOUDS AT 6-8K FEET. CHANCES FOR SHRA/TSRA WILL INCREASE LATE SUNDAY MORNING AND PEAK BETWEEN 19Z- 23Z. CIGS OF 3-5K FEET ARE EXPECTED WITH THIS ACTIVITY ALONG WITH MOUNTAIN OBSCURATIONS. STORMS COULD BRING GUSTY WINDS IN EXCESS OF 35 KTS THESE STORMS...AS WELL AS REDUCED VSBY. SLIGHT CHANCES FOR SHRA/TSRA WILL CONTINUE THROUGH EARLY NEXT WEEK. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...ISOLATED SHRA/TSRA ARE POSSIBLE THROUGH TONIGHT. SHOWERS AND THUNDERSTORMS WILL BE FAVORED OVER CLARK...NYE...LINCOLN AND MOHAVE COUNTIES ON SUNDAY. GUSTS EXCEEDING 35 KTS ARE POSSIBLE WITH THUNDERSTORMS. CIGS WILL MAINLY BE 4K-6K FEET IN AND NEAR SHRA/TSRA OTHERWISE 8K-12K FEET. VSBY MAY BE REDUCED TO MVFR OR LOWER AND MOUNTAIN OBSCURATIONS ARE LIKELY IN AND NEAR ANY SHRA/TSRA. OUTSIDE OF TSRA EXPECT SOUTHWEST WINDS TO INCREASE TO 10- 20 KTS WITH GUSTS 20-30 KTS IN MOST LOCATIONS BY THE AFTERNOON. CHANCES FOR SHRA/TSRA WILL CONTINUE THROUGH EARLY NEXT WEEK...MAINLY FROM LAS VEGAS EAST. && .SHORT TERM...TONIGHT THROUGH MONDAY NIGHT. IT LOOKS LIKE THE INGREDIENTS ARE COMING TOGETHER FOR AN AN ACTIVE WEATHER DAY SUNDAY ACROSS SOUTHERN SOUTHERN NEVADA AND SURROUNDING AREAS OF NORTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. ANOMALOUSLY HIGH MOISTURE CONTENT WILL REMAIN IN PLACE ACROSS THE REGION WITH PWAT VALUES OF 1.0-1.3 INCHES AND SURFACE DEWPOINTS GENERALLY IN THE 60S. THE LIFTING MECHANISM NEEDED TO TURN THIS MOISTURE INTO SHOWERS AND THUNDERSTORMS IS COMING IN THE FORM OF A VIGOROUS LOW PRESSURE SYSTEM CURRENTLY OFF THE NORTHERN CALIFORNIA COAST. THE CENTER OF THIS BROAD SYSTEM IS FORECAST TO MOVE INLAND OVER NORTHERN CALIFORNIA SUNDAY BUT A VORT MAX AND 50-60 KNOT JET ROUNDING THE BASE OF THE LOW AND EJECTING UP ACROSS SOUTHERN NEVADA WILL PROVIDE PLENTY OF DYNAMIC FORCING COMBINED WITH SOME DESTABILIZATION DUE TO COOLER AIR ALOFT ASSOCIATED WITH THE SYSTEM. FORECAST SOUNDINGS LATE SUNDAY MORNING INDICATE CONSIDERABLE INSTABILITY WITH CAPE VALUES AROUND 1500-1800 J/KG...LIFTED INDICES AROUND -5 AND CONSIDERABLE SPEED SHEAR WITH THE STRENGTHENING SOUTH-SOUTHWEST FLOW. THIS SHOULD LEAD TO FAST MOVING FAIRLY ORGANIZED THUNDERSTORMS AND THE POTENTIAL FOR TRAINING CELLS WHICH WILL ELEVATE THE FLASH FLOOD THREAT. THIS COULD LEAD TO MORE THAN JUST LOCALIZED FLASH FLOOD POTENTIAL SUNDAY AND JUSTIFIES THE FLASH FLOOD WATCH THAT IS ALREADY IN EFFECT UNTIL SUNDAY EVENING. THE BEST WINDOW FOR THESE THINGS TO COME TOGETHER LOOKS TO BE BETWEEN 12Z AND 18Z THEN CONTINUING THROUGH SUNDAY AFTERNOON...SO WE SHOULD SEE AN EARLY START TO STORM DEVELOPMENT. AS THE VORT MAX CONTINUES LIFTING UP THROUGH UTAH SUNDAY EVENING... DRY SOUTHWEST FLOW ALOFT SHOULD GRADUALLY DECREASE MOISTURE CONTENT BUT ISOLATED TO SCATTERED SHOWERS WILL STILL BE POSSIBLE OVER SOUTHERN NEVADA AND NORTHWEST ARIZONA SUNDAY NIGHT INTO MONDAY MORNING. ADDITIONAL ENERGY IS FORECAST TO DIVE DOWN THE WEST COAST MONDAY AND DRAG THE TROUGH SOUTHWARD WHILE SPINNING IT UP INTO A CLOSED LOW CENTERED NEAR YUMA ARIZONA BY TUESDAY MORNING. THIS WILL PLACE MOHAVE COUNTY NEAR THE NORTHEAST QUADRANT OF THE LOW LEADING TO A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS. IN ADDITION...THIS WILL KEEP COOL TEMPERATURES IN PLACE ACROSS THE REGION WITH HIGHS 3-5 DEGREES BELOW NORMAL. .LONG TERM...TUESDAY THROUGH SATURDAY. YET ANOTHER SHORTWAVE TROUGH WILL BE CENTERED DIRECTLY OVER OUR AREA TO START THE LONG TERM PERIOD. THIS SHORTWAVE WILL SPIN UP INTO A CLOSED LOW CENTERED OVER THE LOWER COLORADO RIVER VALLEY ALONG THE CALIFORNIA/ARIZONA BORDER TUESDAY NIGHT AND BE NEARLY STATIONARY THROUGH WEDNESDAY. THIS WILL KEEP COOLER CONDITIONS AROUND THROUGH AT LEAST MID WEEK ALONG WITH A CHANCE OF SHOWERS CONTINUING OVER PORTIONS OF LINCOLN, CLARK, SAN BERNARDINO, AND MOHAVE COUNTIES. GIVEN THE FAIRLY GOOD MODEL AGREEMENT, DID EXPAND PRECIP CHANCES A LITTLE FARTHER WEST AND INCREASED POPS A BIT. THE LOW WILL THEN EDGE INTO CENTRAL ARIZONA THURSDAY AND FINALLY DEPART THURSDAY NIGHT INTO FRIDAY. COULD STILL SEE SOME SHOWERS LINGERING ACROSS NORTHWEST ARIZONA (PERHAPS SLIGHTLY FARTHER WEST) THURSDAY. HAVE GONE WITH AN AREA-WIDE DRY FORECAST FRIDAY AND FRIDAY NIGHT WITH MORE OF A QUASI- ZONAL FLOW ALOFT SETTING IN. THE 00Z MODELS SUGGEST DRY CONDITIONS MAY CONTINUE INTO SATURDAY BUT RUN-TO-RUN MODEL TRENDS HAVE NOT BEEN VERY GOOD. THERE ARE SIGNS THAT ANOTHER TROUGH MAY APPROACH OR SWING INTO THE SOUTHWEST AT SOME POINT NEXT WEEKEND. STILL A LOT OF UNCERTAINTY WITH TIMING AND JUST HOW DEEP/STRONG IT MAY BE. WILL KEEP AN EYE ON MODEL TRENDS AND ADJUST AS NECESSARY. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE REQUIRED THIS WEEKEND. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ UPDATE/AVIATION...WOLCOTT SHORT TERM........ADAIR LONG TERM.........PADDOCK FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1215 AM EDT SUN OCT 18 2015 .SYNOPSIS... A STRONG BUT DRY COLD FRONT WILL MOVE THROUGH TONIGHT. HIGH PRESSURE WILL BUILD OVER THE AREA THIS WEEKEND THROUGH MUCH OF NEXT WEEK. THE NEXT FRONTAL SYSTEM WILL APPROACH THE REGION LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1215 AM SUNDAY...APPEARS THAT THE DRY COLD FRONT HAS MOVED THROUGH THE AREA AS OBSERVATIONS INDICATE THAT A SURGE OF COLD AIR WAS OCCURRING OVER THE AREA LATE TONIGHT. POST FRONTAL DRY/COLD ADVECTION AND LOW LEVEL MIXING WILL PRECLUDE ANY FOG DEVELOPMENT OVERNIGHT. A WIDE RANGE OF LOWS EXPECTED...WITH UPR 30S INLAND TO LOW 50S OBX...WHERE WIND ADVECTING OVER THE RELATIVELY WARM SOUND WATERS WILL KEEP TEMPS UP HERE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AS OF 330 PM SAT...DEEP/COLD TROUGH AXIS PROGGED TO MOVE ACROSS EASTERN CONUS ON SUNDAY WITH SFC HIGH PRES BUILDING INTO THE OHIO VALLEY. LOW LEVEL THICKNESS VALS ON PAR WITH MOS GUID FORECASTING CHILLY MAX TEMPS IN THE UPR 50S TO NEAR 60...COOLEST NORTH. CONTINUED CAA AND NORTH WINDS WILL MAKE IT FEEL QUITE BRISK DESPITE FULL SUNSHINE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... AS OF 330 PM SAT...MINOR ADJUSTMENTS TO TEMPS DURING PERIOD. MODELS REMAIN IN GOOD AGREEMENT THAT RIDGING SFC AND ALOFT WILL CONTINUE THROUGH MID WEEK...FOLLOWED BY ANOTHER DRY COLD FRONTAL PASSAGE FRIDAY. MAIN SIGNIFICANT WX THREAT DURING PERIOD WILL BE PSBL FROST SUN NIGHT AND AGAIN MON NIGHT. MODEL GDNC CONTINUES TO INDICATE COLDEST TEMPS SUN NIGHT WITH LOWS 33-36 DEGS FOR NORMALLY COLDER AREAS ALONG AND W OF HWY 17. COULD EVEN SEE SOME 32 DEG READINGS IN ISOLATED AREAS BUT NOT EXPECTED TO BE WDSPRD ENOUGH TO WARRANT FREEZE WATCH...BUT FROST ADVSY LIKELY TO BE ISSUED WITH NEXT FULL FCST PACKAGE AROUND 4 AM SUNDAY. GOOD RADIATIONAL COOLING CONDITIONS LIKELY AGAIN MON NIGHT WITH SFC HIGH CENTER OVER AREA RESULTING IN LIGHT WINDS ALL THE WAY TO COAST. MOS GDNC INDICATING LOWS MID TO UPR 30S FOR MOST INLAND AREAS...AND COULD SEE SCT FROST THREAT EVEN CLOSER TO COAST THAN ON SUN NIGHT. TEMPS WILL GRADUALLY MODERATE TUE-THU WITH RIDGING ALOFT WHILE SFC HIGH EXTENDS OVER AREA FROM OFFSHORE. LOWS WILL BE IN 40S AND 50S WITH HIGHS IN THE 70S. FRIDAY TO SATURDAY...12Z GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT WITH ANOTHER DRY COLD FRONT MOVING THROUGH EARLY FRIDAY FOLLOWED BY HIGH PRES RIDING IN FROM N FRI NIGHT AND SAT. TEMPS WILL DROP BACK INTO 40S FRI NIGHT WITH HIGHS IN 60S FOR SAT. && .AVIATION /04Z SUNDAY THROUGH THURSDAY/... SHORT TERM /THROUGH SUNDAY NIGHT/... AS OF 1215 AM SUNDAY...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD AS HIGH PRESSURE BUILDS OVER THE REGION FROM THE NORTH. DRY ADVECTION FOLLOWING THE PASSAGE OF A DRY COLD FRONT AND AMPLE LOW LEVEL MIXING WILL INHIBIT LOW CLOUD AND FOG FORMATION OVERNIGHT. KMHX 88D VWP SHOWS 40 KNOTS AT 1 KFT SO WILL KEEP NON CONVECTIVE LLWS AT ALL TERMINALS. SHORT TERM MODELS SHOW WINDS DECREASING AFTER ABOUT 09Z SO WILL CARRY LLWS WORDING UNTIL THEN. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 330 PM SAT...HIGH CONFIDENCE OF VFR CONDITIONS WILL CONTINUE THROUGH THIS PERIOD AS HIGH PRESSURE DOMINATES THE REGION. && .MARINE... SHORT TERM /THROUGH SUNDAY/... AS OF 1215 AM SUNDAY...STRONG COLD AIR ADVECTION OVERNIGHT WILL PRODUCE NORTHERLY FLOW TO 25 KT OVER MOST OF THE MARINE ZONES OVERNIGHT INTO SUNDAY SO WILL CONTINUE CURRENT SCA HEADLINES. WINDS WILL PEAK LATE TONIGHT IN THE 20-25 KT RANGE WITH SOME GUSTS TO 30 KT FOR ALL WATERS AND SOUNDS...EXCLUDING THE BAY...PAMLICO...AND NEUSE RIVERS...THOUGH OCNL GUSTS TO 25 KT ARE CERTAINLY POSSIBLE PER HRRR FCST. SEAS WILL BUILD DRAMATICALLY TONIGHT AND PEAK IN THE 5 TO 8 FT RANGE...HIGHEST OUTER CENTRAL AND NRN WATERS. WINDS WILL COME DOWN A BIT TO 10-20 KT ON SUNDAY BUT SEAS WILL REMAIN ELEVATED ABOVE 6 FT. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 330 PM SAT...MODELS REMAIN IN GOOD AGREEMENT WITH FINAL CAA SURGE PRODUCING N-NE WINDS 20-25 KT OVER MOST OF WATERS SUN NIGHT INTO MONDAY...AND EXTENDED SCA HEADLINES ACCORDINGLY. WINDS DIMINISH QUICKLY LATE MON AND MON NIGHT. SFC RIDGE AXIS EXTENDING W TO E ACROSS WATERS WILL LEAD TO LIGHT AND SOMEWHAT VRBL CONDITIONS TUE-THU. LATEST WAVE GDNC SUPPORTS PREVIOUS FCST WTIH SEAS BUILDING TO 5-7 FT SUN NIGHT...THEN SUBSIDING ON MONDAY WITH DIMINISHING WINDS. HEIGHTS MAINLY 2-3 FT TUE-THU. && .CLIMATE... RECORD MIN TEMPS FOR 10/19 (MONDAY) LOCATION TEMP/YEAR NEW BERN 33/1948 (KEWN ASOS) CAPE HATTERAS 39/1978 (KHSE ASOS) GREENVILLE 33/1970 (COOP - NOT KPGV AWOS) MOREHEAD CITY 37/1967 (COOP - NOT KMRH ASOS) KINSTON 30/1973 (COOP - NOT KISO AWOS) JACKSONVILLE 36/1992 (KNCA AWOS) && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ135. SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ130-131. SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ150-152-154. SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ156-158. && $$ SYNOPSIS...TL NEAR TERM...JME/HSA/TL SHORT TERM...TL LONG TERM...JBM AVIATION...JME/TL MARINE...JME/JBM/HSA/TL CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
830 AM MST SUN OCT 18 2015 .SYNOPSIS... A SERIES OF SLOW MOVING LOW PRESSURE SYSTEMS WILL BRING ELEVATED CHANCES OF SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE MIDDLE OF THE WEEK. SHOWERS AND STORMS ARE POSSIBLE ACROSS SOUTH CENTRAL AZ THIS AFTERNOON AS THE FIRST LOW PRESSURE SYSTEM PASSES ACROSS THE REGION...WITH A MODEST DRYING TREND ON MONDAY. THIS WILL BE SHORT LIVED AS A SECOND LOW MOVES INTO THE DESERT SOUTHWEST ON TUESDAY...AND REMAINS IN PLACE THROUGH THURSDAY. DRIER AIR WILL THEN MOVE INTO THE AREA LATE IN THE WEEK. && .DISCUSSION... EARLY THIS MORNING...PLOTS AND VAPOR IMAGERY DEPICTED A LARGE UPPER TROF ALONG THE WEST COAST...CENTERED OVER NRN CALIFORNIA...WITH A PROMINENT SHORT WAVE ROTATING AROUND THE BASE OF THE TROF AND MOVING ACROSS SRN CA AND APPROACHING ARIZONA. BROAD UPPER DIFLUENCE WAS PRESENT OVER ARIZONA IN ADVANCE OF THE SHORT WAVE...AND LOW LEVEL MOISTURE WAS ELEVATED WITH SURFACE DEWPOINTS OVER THE DESERTS RANGING FROM THE MID 50S TO MID 60S. PROGS DEPICT AN AREA OF MID LEVEL Q-CONVERGENCE MOVING INTO SERN CA AND ARIZONA TODAY...AND CAPE WILL BE INCREASING AS WELL. SPC MESOANALYSIS GRAPHICS FORECAST CAPE WELL IN EXCESS OF 1000 J/KG OVER MOST OF OUR DESERTS BY EARLY AFTERNOON AND MODEL GUIDANCE ALSO INCREASES CAPE IN A SIMILAR FASHION. AS SUCH WE EXPECT AN INCREASE IN SHOWERS AND THUNDERSTORMS AS THE DAY PROGRESSES. WE HAVE RAISED POPS OVER MUCH OF THE AREA WITH MANY LOCALES IN THE 20-30 PERCENT RANGE THIS AFTERNOON...WITH HIGHER VALUES OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX. AT 815 AM A NEW THUNDERSTORM DEVELOPED NEAR FLORENCE JUNCTION...AN INDICATOR OF WHAT IS TO COME LATER IN THE DAY. LATEST HRRR ALSO SUGGESTS SCATTERED SHOWERS/STORMS DEVELOPING DURING THE DAY OVER THE DESERTS. CURRENT FORECASTS LOOK TO BE IN GOOD SHAPE BUT WE WILL BE KEEPING AN EYE ON THE DEVELOPING WEATHER IN CASE FURTHER UPDATES ARE NEEDED. .PREVIOUS DISCUSSION... EARLY MORNING WATER VAPOR IMAGERY REVEALS A SERIES OF SHORTWAVE TROUGHS EMBEDDED WITHIN LARGER-SCALE TROUGHING ACROSS THE WESTERN CONUS. A LARGE UPPER LOW REMAINED QUASI-STATIONARY OFF THE NORTHERN CALIFORNIA COAST WHILE A WEAK SHORTWAVE/MCV THAT PRODUCED STORMS SATURDAY EVENING WAS STILL POSITIONED OVER SOUTHEAST ARIZONA. WEAK UPPER LEVEL SUPPORT IN THE FORM OF A 250MB JET STREAK OVER NORTHERN BAJA CALIFORNIA HAS AIDED IN THE CONTINUED DEVELOPMENT AND RE-GENERATION OF ISOLATED DESERT SHOWERS AND STORMS THIS MORNING ALTHOUGH THE AREAL EXTENT OF THESE SHOWERS SINCE MIDNIGHT HAS REMAINED LIMITED. THIS HAS...HOWEVER...ALLOWED CLOUD COVER TO REMAIN IN PLACE AND CONSEQUENTLY HAS KEPT TEMPERATURES ON THE MILD SIDE /GENERALLY IN THE MID 70S AS OF 09Z/. THE FORECAST CONCERNS FOR TODAY WILL ONCE AGAIN BE DOMINATED BY AN APPROACHING SHORTWAVE TROUGH FROM CALIFORNIA AND ITS IMPACTS AS IT INTERACTS WITH A MODERATELY UNSTABLE ATMOSPHERE ACROSS PORTIONS OF ARIZONA. THE WAVE ITSELF WILL DEEPEN LATER THIS MORNING AND MOVE THROUGH ARIZONA THIS AFTERNOON. WITH MLCAPES ONCE AGAIN FORECAST TO CLIMB INTO THE 250-500 J/KG RANGE...IT`S EASY TO ENVISION STORMS DEVELOPING BY EARLY AFTERNOON AND RAPIDLY PUSHING EASTWARD INTO THE MOUNTAINS. THE EXACT LOCATION WHERE STORMS WILL INITIATE IS UP FOR DEBATE BUT A NUMBER OF HI-RES MODELS AND HI-RES ENSEMBLES DEPICT THE BEST CHANCES FROM PHOENIX EASTWARD. AS SUCH...POPS HAVE BEEN REFINED SLIGHTLY AND INCREASED INTO THE 30-40 PERCENT RANGE AROUND PHOENIX AND INTO THE 50-60 PERCENT RANGE IN THE HIGHER TERRAIN LOCATIONS. ONE CONCERN THAT COULD LIMIT STORM POTENTIAL IS THE ABUNDANT DRY AIR AND ASSOCIATED MID LEVEL DRY ADVECTION THAT IS FORECAST LATER TODAY. ALTHOUGH SIMILAR DRY ADVECTION DIDN`T HAVE TOO ADVERSE OF AN EFFECT ON STORM CHANCES ON SATURDAY AND I`M HESITANT TO WRITE OFF TODAY`S STORM CHANCES ENTIRELY. THE UPPER LOW WILL MOVE SOUTHWARD SOMEWHAT ON MONDAY...RESULTING IN SOME DEGREE OF SHORTWAVE RIDGING ACROSS THE AREA. WHILE STORM CHANCES WON`T DIMINISH ENTIRELY...THEY SHOULD BE REDUCED QUITE A BIT FROM WHAT WE`VE SEEN AS OF LATE AND BE RE-ORIENTED MAINLY TO THE NORTH/EAST OF PHOENIX AND ALSO INTO NORTHERN ARIZONA. ALL IN ALL MONDAY APPEARS TO BE FAIRLY QUIET AT THIS POINT BUT CLIMO-LIKE POPS STILL SEEM WARRANTED GIVEN SLIGHTLY HIGHER THAN NORMAL PWATS AND POSSIBLE SHORTWAVES NOT RESOLVED IN THIS MORNING`S MODEL GUIDANCE. ALL SIGNS CONTINUE TO POINT TO THE UPPER LOW MIGRATING AND STALLING OVER ARIZONA ON TUESDAY AND REMAINING IN PLACE THROUGH THURSDAY. NOT MUCH HAS CHANGED IN THE DETERMINISTIC OR PROBABILISTIC GUIDANCE THIS MORNING WITH NEARLY ALL MODELS INDICATING SLIGHTLY HIGHER THAN NORMAL PWATS AND WATER VAPOR TRANSPORT...BUT WELL BELOW NORMAL HEIGHTS. AFTERNOON INSTABILITY IS FORECAST TO RESIDE IN THE 250-500 J/KG RANGE AND THE GFS/ECMWF BOTH SUGGEST A SHORTWAVE TROUGH WILL MOVE THROUGH THE AREA TUESDAY AFTERNOON/EVENING. AS SUCH...POPS HAVE BEEN INCREASED AND CLOSELY MIRROR THOSE PORTRAYED BY THE NAEFS. 40-50 POPS ACROSS THE LOWER AZ DESERTS WITH EVEN HIGHER VALUES IN THE MOUNTAINS EAST OF PHOENIX SEEM MORE THAN WARRANTED AT THIS POINT ALTHOUGH THERE IS CONSIDERABLE UNCERTAINTY WITH RESPECT TO WHICH AREAS WILL SEE LOCALLY HEAVY RAIN AND/OR STRONG STORMS. SOME OF THE CONSENSUS GUIDANCE DEPICTS THE HIGHEST RAIN CHANCES ACROSS YUMA/LA PAZ AND GILA COUNTIES WHILE LEADING MARICOPA/PINAL MAINLY DRY. NOT GOING TO SLICE THINGS THAT THIN AT THIS POINT AND MAINTAIN NAEFS-LIKE VALUES TUESDAY AND TUESDAY NIGHT. WHILE THE LOW WILL REMAIN IN PLACE OVERHEAD WEDNESDAY AND THURSDAY...MOISTURE WILL BEGIN TO SHIFT INTO NEW MEXICO AND FORECAST SOUNDINGS GRADUALLY BECOME LESS AND LESS SUPPORTIVE OF STORMS ACROSS THE AREA WEDNESDAY...AND EVEN MORE SO ON THURSDAY. MEANWHILE DRY ADVECTION WILL BEGIN TO TAKE HOLD ACROSS SOUTHERN CALIFORNIA...FURTHER REDUCING STORM CHANCES ACROSS THE AREA. POPS WILL REMAIN ELEVATED IN LINE WITH CONS MODELS AND 00Z NAEFS DATA BUT THERE SHOULD BE A CLEAR TREND TOWARD DRIER WEATHER LATE IN THE WEEK INTO NEXT WEEKEND. AS FOR TEMPERATURES OVER THE NEXT WEEK...SLIGHTLY ABOVE NORMAL HIGHS ARE EXPECTED TODAY AND MONDAY. GIVEN THE ANOMALOUSLY LOW HEIGHTS FORECAST TO RESIDE ACROSS THE AREA FROM TUESDAY THROUGH LATE WEEK...IT SEEMS ALMOST CERTAIN THAT BELOW NORMAL TEMPS CAN BE EXPECTED FROM MID WEEK ONWARD. EVEN WITH THE LOW DEPARTING LATE IN THE WEEK/NEXT WEEKEND...PERSISTENT WEAK TROUGHING ALOFT SUGGESTS THAT WE WON`T SEE ANY SIGNIFICANT WARMUPS AT ANY POINT IN THE NEXT WEEK. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... A FEW MORNING SHOWERS AND THUNDERSTORMS POSSIBLE ACROSS FAR EAST VALLEY...INCLUDING KIWA...BUT AN EXPECTED BREAK THROUGH AROUND NOON. EXPECTING ANOTHER ROUND OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS THIS AFTERNOON...BUT NOT CONFIDENT ENOUGH TO GO ABOVE VICINITY FOR AREA TERMINALS. EASTERLY SFC WINDS WILL BE FAVORED FOR MUCH OF THE PERIOD...HOWEVER SHOULD HAVE A PERIOD OF SOUTHERLY TO WESTERLY FLOW LATE THIS AFTERNOON AND EVENING. CIGS SHOULD REMAIN ABOVE 6K FT THROUGH TONIGHT. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... LITTLE TO NO AVIATION CONCERN THROUGH MONDAY MORNING AS SHOWER ACTIVITY LIKELY TO REMAIN NORTH AND EAST OF TERMINAL SITES. KBLH SFC WINDS COULD BECOME GUSTY OUT OF THE SOUTH THIS AFTERNOON. OTHERWISE...ONLY SCT CLOUD DECKS FOR THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... UNSETTLED WEATHER DURING THE MIDDLE OF THE WEEK WILL TRANSITION TO MUCH DRIER CONDITIONS LATE IN THE WEEK. WETTING RAINS WILL FAVOR CENTRAL ARIZONA DISTRICTS...AND ESPECIALLY HIGHER TERRAIN LOCATIONS NORTH AND EAST OF PHOENIX. AFTERNOON HUMIDITY VALUES IN A 25 TO 40 PERCENT RANGE EARLIER IN THE WEEK WILL DECREASE TO A 20 TO 30 PERCENT RANGE BY THE END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. WIND SPEEDS WILL NOT BE PARTICULARLY STRONG...WITH ONLY SOME OCCASIONAL HIGHER GUSTS IN SOUTHEAST CALIFORNIA TUESDAY AND WEDNESDAY AFTERNOON. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...CB PREVIOUS DISCUSSION...LEINS AVIATION...KUHLMAN FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1036 AM EDT SUN OCT 18 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST ACROSS THE AREA THROUGH MONDAY THEN SOUTH ACROSS THE MID ATLANTIC ON TUESDAY. A COLD FRONT APPROACHING FROM THE NORTH ON TUESDAY WILL PASS THROUGH TUESDAY NIGHT. THIS FRONT WILL MOVE BACK NORTH AS A WARM FRONT WEDNESDAY AS LOW PRESSURE TRACKS THROUGH SOUTHERN CANADA AND NORTHERN NEW ENGLAND...DRAGGING A COLD FRONT ACROSS ON THURSDAY. HIGH PRESSURE RETURNS FOR FRIDAY AND SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... TEMPERATURES RISING A LITTLE FASTER THAN FORECAST UNDER MOSTLY CLEAR CONDITIONS AND NORTHWEST WIND 5 TO 10 KT. ALSO DEW POINTS A FEW DEGREES HIGHER THIS MORNING...HOWEVER WITH MIXING DEW POINTS WILL DROP OFF AGAIN THIS AFTERNOON. INSTABILITY BKN STRATOCUMULUS CLOUDS ARE FORECAST TO REDEVELOP MAINLY FROM 16Z/NOON UNTIL 20Z/4 PM WITH THE APPROACH OF THE COLD UPPER LVL TROUGH AXIS. NAM AND HRRR CONTINUE TO INDICATE THE POSSIBILITY OF SPRINKLES LATE THIS MORNING INTO THIS AFTERNOON IN THE STRONG NORTHWEST FLOW...HOWEVER WITH LIMITED LOW LVL MOISTURE IN PLACE...DECIDED NOT TO INCLUDE THEM IN THE FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... FOR TONIGHT...WITH CANADIAN HIGH PRES ADVECTING EAST MUCH CLOSER TO THE AREA...SFC WINDS WILL DECOUPLE EARLIER AS STRONGER RADIATIONAL COOLING DEVELOPS ACROSS MORE OF THE LOCAL AREA THAN THIS MORNING. FORECASTING WIDESPREAD TEMPS IN THE MID AND UPPER 20S...A KILLING FREEZE...FOR THE SAME AREA UNDER A FREEZE WARNING THRU 10 AM THIS MORNING. CLOSER TO THE COAST...FORECASTING TEMPS MAINLY IN THE UPPER 20S AND LOW 30S RESULTING IN A MARGINAL FREEZE. *NOTE THAT BASED ON AN ANALYSIS OF OVERNIGHT LOW TEMPS...WE MAY DECIDE TO CANCEL THE FREEZE WARNING FOR PARTS OF THE REGION THAT EXPERIENCED A KILLING FREEZE WITH OVERNIGHT LOWS IN THE 20S. AS THE HIGH MOVES SOUTH OF THE AREA MONDAY...LOW LVL WARM AIR ADVECTION DEVELOPS AS SW WINDS INCREASE DURG THE AFTN. TEMPS WILL REMAIN ARND 10 DEGREES BELOW NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THROUGH THIS TIME FRAME...PROGRESSIVE WESTERLY FLOW EXPECTED AS CLOSED UPPER LEVEL LOW WELL TO THE NORTH IN EASTERN CANADA MOVES EAST MID WEEK...WITH SOUTHWESTERN UNITED STATES LOW REMAINING NEARLY STATIONARY. NEXT SHORTWAVE IN CENTRAL CANADA DIVES SOUTHEASTWARD ACROSS THE GREAT LAKES REGION MID WEEK...THEN PASSES ACROSS NORTHERN NEW ENGLAND/SOUTHEAST CANADIAN PROVINCES THURSDAY. THERE ARE DIFFERENCES IN THE STRENGTH OF THIS SHORTWAVE AS IT MOVES TO OUR NORTH...BUT REASONABLE OVERALL AGREEMENT IS NOTED IN THE OPERATIONAL MODEL SUITE. RIDGE BUILDS BEHIND THIS DEPARTING TROUGH FRIDAY AND SATURDAY...OF COURSE DEPENDENT ON EVENTUAL AMPLIFICATION OF THE TROUGH...WHICH AT THIS STAGE IS UNCLEAR. AT THE SFC...A COLD FRONT APPROACHES FROM THE NORTH MONDAY NIGHT AND TUESDAY...EITHER PASSING JUST SOUTH OR REMAINING OVER THE AREA TUESDAY NIGHT. THEN...THE FRONT WILL JUMP BACK TO THE NORTH AS A WARM FRONT WEDNESDAY...AS THE UPPER TROUGH AND ASSOCIATED SFC COLD FRONT APPROACHES. COLD FRONTAL PASSAGE SOMETIME LATER THURSDAY LOOKS LIKELY. HIGH PRESSURE THEN BUILDS OUT OF CANADA FRIDAY AND SATURDAY. AS FOR SENSIBLE WEATHER...A FEW SPRINKLES FROM TIME TO TIME CANNOT BE RULED OUT TUE NIGHT THROUGH WED WITH THE FRONT IN OUR VICINITY. HOWEVER...THE BEST CHANCE FOR SHOWERS LOOKS TO BE THURSDAY AHEAD OF THE TROUGH WHEN BEST LIFT IS REALIZED. WILL MAINTAIN POPS IN THE SLIGHT CHANCE RANGE DUE TO LACK OF DEEP MOISTURE. DO NOT FORESEE ANY THUNDER PER STABILITY INDICES. WITH WAA WELL UNDERWAY...EXPECT TEMPS TO REBOUND THROUGH MID WEEK. NEAR TO SLIGHTLY ABOVE NORMAL READINGS ARE EXPECTED. A SLIGHT COOL DOWN IS FORECAST BEHIND THE FRONT LATE WEEK...WITH TEMPS AVERAGING SLIGHTLY BELOW NORMAL BY THEN. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... HIGH PRESSURE BUILDS TODAY AND TONIGHT. VFR. SCT-BKN STRATOCU FOR THE AFTN BEFORE CLOUDS GIVE WAY TO CLEARING THIS EVENING. AN ISOLATED SHOWER OR SPRINKLE CANNOT BE RULED OUT THIS AFTERNOON. NW WIND 10 TO 15 KTS WILL PREVAIL TODAY. GUSTS UP TO 20 KTS ARE ALSO ANTICIPATED...BUT POSSIBLY ONLY OCCASIONAL FOR SOME TERMINALS. WINDS ABATE SHORTLY AFTER SUNSET. FOR NYC METRO...WIND DIRECTION SHOULD GENERALLY REMAIN TO THE RIGHT OF 310 MAGNETIC. .OUTLOOK FOR 12Z MON THROUGH THU... .MON-WED...VFR. SW WINDS G20-25KT ON TUESDAY. .THU...MAINLY VFR BUT LOCAL MVFR POSSIBLE WITH A SLIGHT CHANCE OF SHOWERS. && .MARINE... NO CHANGES AT THIS TIME. NW WIND 15 TO 20 KT WITH OCCASIONAL GUSTS UP TO 25 KT WILL CONTINUE THROUGH TODAY WITH SEAS OF 2-4 FT ACROSS NEARSHORE ATLANTIC WATERS. TONIGHT...BECAUSE FCST MODELS SHOW AN INCREASING NW PRES GRADIENT...A SMALL CRAFT ADVISORY WAS ISSUED FOR THE ATLANTIC COASTAL WATERS FROM 8 PM THIS EVENING UNTIL 6 AM MONDAY MORNING. NW WINDS 20-25 KT WITH SEAS OF 3-4 FT ARE FORECAST. MONDAY...WINDS WILL BECOME WSW BY AFTERNOON AT 15-20 KT WITH SEAS OF 3-4 FT AS HIGH PRES MVS SOUTH OF THE AREA. A TIGHTENING PRESSURE GRADIENT AHEAD OF AN APPROACHING COLD FRONT FROM THE NORTH WILL ALLOW WEST/SW WINDS TO INCREASE MONDAY NIGHT AND REMAIN RATHER STRONG TUESDAY. SCA CONDITIONS ARE LIKELY FOR MOST OF THE AREA WATERS...WITH OCEAN SEAS BUILDING PER WAVE WATCH. AS THE FRONT MOVES THROUGH OR SETTLES NEARBY TUESDAY NIGHT...WINDS WILL DIMINISH AND SEAS WILL SUBSIDE. THE FRONT THEN MOVES BACK TO THE NORTH AS A WARM FRONT LATER WEDNESDAY. AS SUCH...WINDS WILL SHIFT FROM THE W TUE NIGHT TO THE N LATE TUE NIGHT INTO WED...ALTHOUGH THAT DEPENDS ON HOW FAR SOUTH THE FRONT SETTLES. THEN WINDS SHIFT BACK AROUND TO THE SOUTH WED NIGHT...AND SW THURSDAY AHEAD OF THE APPROACHING COLD FRONT. ANOTHER WIND SHIFT OCCURS THU NIGHT AS THE COLD FRONT MOVES THROUGH. && .FIRE WEATHER... A DRY AIR MASS COMBINED WITH NORTHWEST WINDS OF 10 TO 20 MPH...LOW HUMIDITY OF 25 TO 35 PERCENT AND NO MEASURABLE RAIN DURING THE PAST WEEK WILL CONTINUE TO CREATE CONDITIONS MORE CONDUCIVE FOR FIRE SPREAD FROM LATE THIS MORNING UNTIL SUNSET TODAY. && .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE FORECAST PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...FREEZE WARNING FROM 2 AM TO 10 AM EDT MONDAY FOR CTZ005>012. NY...FREEZE WARNING FROM 2 AM TO 10 AM EDT MONDAY FOR NYZ067>071- 078>081-177. NJ...FREEZE WARNING FROM 2 AM TO 10 AM EDT MONDAY FOR NJZ002-004- 103>105-107. MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT MONDAY FOR ANZ350-353-355. && $$ SYNOPSIS...GC/PW NEAR TERM...MET SHORT TERM...GC LONG TERM...PW AVIATION...JC MARINE...MET FIRE WEATHER... HYDROLOGY...GC/PW
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
902 AM CDT SUN OCT 18 2015 ...UPDATE TO SYNOPSIS... .SYNOPSIS... ISSUED AT 900 AM CDT SUN OCT 18 2015 WV Imagery indicates a weak upper level ridge of high pressure transitioning eastward across the Central Plains. Meanwhile, an upper level trough of low pressure is pushing ashore off the Pacific into the Pacific Northwest and northern California. Near the surface, a lee side trough of low pressure is slowly strengthening across extreme eastern Colorado. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CDT SUN OCT 18 2015 Efficient mixing is expected as the boundary layer depth increases this late this morning and afternoon. GFS LAMP indicates gusts into the mid 30s knots range as winds turn southwest and result in downslope and enhanced adiabatic warming for highs approaching 80 degrees. Despite the upper ridge beginning to break down across the Central Plains on Monday, the 850 mb temperatures across the high plains increases by Monday afternoon. Temperatures along and ahead of the eastern Colorado trough should exceed 80 degrees Monday afternoon. The axis of breezy to windy southwest wind should gradually move farther east into central Kansas as well. .LONG TERM...(Monday THROUGH Saturday) ISSUED AT 314 AM CDT SUN OCT 18 2015 The continued warming trend should extend into Tuesday in advance of the approaching upper low moving into the desert sw/southern Rockies region. GFS MOS indicated low to mid 80s possible which at this point is a good 15 degrees or more above normal highs. The system has been modeled for several runs now as a closed low weakening to a mid tropospheric open wave moving into the central and southern Plains around Thursday. Highest pops starts about Thursday morning and last through Thursday night/early Friday. With the initial advance of cloudiness and possible showers and thunderstorms Wednesday along the warm conveyor belt/mid level baroclinic zone intersection, forecast high temperatures are cut 10 to 15 degrees in Wednesday. Highs may be relegated to the 60s and 70s for the remainder of the week. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Monday MORNING) ISSUED AT 600 AM CDT SUN OCT 18 2015 Gusty south winds of 20 to near 25 knots will develop by the early afternoon as 35 to 45 knots winds located in the 900mb to 850mb level mixes down to the surface. These very windy conditions are expected to fall back into the 15 to 20 knot range after sunset. 06z NAM BUFR Moisture profiles along with the latest RAP and HRRR indicate VFR conditions today and tonight. && .PRELIMINARY POINT TEMPS/POPS... DDC 79 55 82 59 / 0 0 0 0 GCK 80 55 83 58 / 0 0 0 0 EHA 78 55 83 56 / 0 0 0 0 LBL 80 55 83 58 / 0 0 0 0 HYS 80 57 82 60 / 0 0 0 0 P28 78 57 82 58 / 0 0 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SYNOPSIS...JJohnson SHORT TERM...Russell LONG TERM...Russell AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
602 AM CDT SUN OCT 18 2015 ...Updated Aviation Discussion... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 314 AM CDT SUN OCT 18 2015 Efficient mixing is expected as the boundary layer depth increases this late this morning and afternoon. GFS LAMP indicates gusts into the mid 30s knots range as winds turn southwest and result in downslope and enhanced adiabatic warming for highs approaching 80 degrees. Despite the upper ridge beginning to break down across the Central Plains on Monday, the 850 mb temperatures across the high plains increases by Monday afternoon. Temperatures along and ahead of the eastern Colorado trough should exceed 80 degrees Monday afternoon. The axis of breezy to windy southwest wind should gradually move farther east into central Kansas as well. .LONG TERM...(Monday THROUGH Saturday) ISSUED AT 314 AM CDT SUN OCT 18 2015 The continued warming trend should extend into Tuesday in advance of the approaching upper low moving into the desert sw/southern Rockies region. GFS MOS indicated low to mid 80s possible which at this point is a good 15 degrees or more above normal highs. The system has been modeled for several runs now as a closed low weakening to a mid tropospheric open wave moving into the central and southern Plains around Thursday. Highest pops starts about Thursday morning and last through Thursday night/early Friday. With the initial advance of cloudiness and possible showers and thunderstorms Wednesday along the warm conveyor belt/mid level baroclinic zone intersection, forecast high temperatures are cut 10 to 15 degrees in Wednesday. Highs may be relegated to the 60s and 70s for the remainder of the week. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Monday MORNING) ISSUED AT 600 AM CDT SUN OCT 18 2015 Gusty south winds of 20 to near 25 knots will develop by the early afternoon as 35 to 45 knots winds located in the 900mb to 850mb level mixes down to the surface. These very windy conditions are expected to fall back into the 15 to 20 knot range after sunset. 06z NAM BUFR Moisture profiles along with the latest RAP and HRRR indicate VFR conditions today and tonight. && .PRELIMINARY POINT TEMPS/POPS... DDC 79 54 80 59 / 0 0 0 0 GCK 80 54 83 58 / 0 0 0 0 EHA 78 54 80 56 / 0 0 0 0 LBL 80 54 80 58 / 0 0 0 0 HYS 80 55 82 60 / 0 0 0 10 P28 78 53 79 58 / 0 0 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
744 AM EDT SUN OCT 18 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 523 AM EDT SUN OCT 18 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A FAIRLY DEEP TROF OVER ERN N AMERICA AND A RIDGE TO THE W WITH AXIS OVER THE HIGH PLAINS. BTWN THESE FEATURES...NW FLOW CONTINUES OVER THE UPPER GREAT LAKES EARLY THIS MORNING...BUT HEIGHTS ARE RISING AS THE RIDGE AND TROF ARE SHIFTING E. LES CONTINUES INTO THE ERN FCST AREA...E OF MARQUETTE. LES WAS MDT TO HVY AT TIMES IN ALGER AND NRN SCHOOLCRAFT COUNTIES FOR SEVERAL HRS DURING THE NIGHT...BUT LES IS NOW SHOWING A NOTABLE DIMINISHING TREND UNDER FALLING SUBSIDENCE INVERSION. WITH THE START OF WAA...LAKE EFFECT CLOUDS OFF WRN LAKE SUPERIOR ARE DECREASING. SFC HIGH PRES RIDGE AXIS NOW JUST W OF LAKE SUPERIOR IS FCST TO SHIFT QUICKLY E ACROSS THE FCST AREA TODAY. ALONG WITH THE FALLING SUBSIDENCE INVERSION...LES INTO THE ERN FCST WILL END THIS MORNING. ONLY MINOR ADDITIONAL SNOW ACCUMULATIONS UNDER AN INCH WILL OCCUR EARLY THIS MORNING. IF THERE ARE ANY LINGERING CLOUDS OVER THE W AFTER SUNRISE...THEY WILL QUICKLY CLEAR OUT THIS MORNING. SKIES WILL ALSO BECOME MOSTLY SUNNY E THIS AFTN. HIGHS TODAY WILL TOP OUT IN THE 40S E TO AS HIGH AS THE LOWER 50S W WHERE WAA AND MORE SUN WILL AID WARMING. PRES GRADIENT WILL QUICKLY TIGHTEN AFTER PASSAGE OF THE HIGH PRES RIDGE AXIS AS A RAPIDLY DEEPENING SFC LOW TRACKING E TO HUDSON BAY PUSHES AN ASSOCIATED TROF INTO THE WRN PLAINS. EXPECT S WINDS TO ALREADY BEGIN TO SHOW SOME GUSTINESS DURING THE LATTER PORTION OF THE AFTN OVER THE W HALF. WINDS WILL THEN BE THE MAIN STORY TONIGHT. A DEEP SFC LOW OVER HUDSON BAY...DROPPING TO A PRES OF AROUND 28.7 INCHES...WILL DRIVE ASSOCIATED SFC TROF INTO MN. A 50+KT LOW-LEVEL JET WILL SHIFT INTO UPPER MI DURING THE NIGHT. WHILE WAA AND NOCTURNAL COOLING WILL RESULT IN CONSIDERABLE STABILITY PREVENTING ACCESS TO THE PEAK LOW- LEVEL WINDS...MAX PRES FALLS OF AROUND 6MB/3HR SHIFTING ACROSS NRN ONTARIO WILL AID AN INCREASE IN SFC WINDS/GUSTINESS...MAINLY IN THE HIGH TERRAIN AND ESPECIALLY IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR AND ALONG NRN LAKE MI E OF ESCANABA. COULD BECOME FAIRLY WINDY AT LEAST FOR A FEW HRS DURING THE TIME THAT THE ISALLOBARIC WIND COMPONENT IS MAXIMIZED. WINDS WILL KEEP MIN TEMPS UP IN THE 30S TO LWR 40S TONIGHT. INTERIOR SHELTERED LOCATIONS IN THE CNTRL AND E MAY FALL TO THE LWR 30S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 443 AM EDT SUN OCT 18 2015 TEMPERATURES THROUGH THE EXTENDED WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH A COUPLE CHANCES FOR RAINFALL. MONDAY THROUGH TUESDAY...THE BROAD SURFACE RIDGE OVER THE MID ATLANTIC STATES MONDAY WILL CONTINUE TO SLIDE TO THE SOUTHEAST. AS THIS HAPPENS...A FAIRLY STRONG LOW PRESSURE SYSTEM OVER HUDSON BAY WILL SLIDE INTO NORTHWEST QUEBEC. THERE WILL BE A FAIRLY STRONG PRESSURE GRADIENT BETWEEN THE TWO SYSTEMS ALONG WITH A 40 TO 50 KNOT LLJ...MAINLY OVER EASTERN LAKE SUPERIOR AND NORTHERN LAKE MICHIGAN MONDAY MORNING BEFORE THE GRADIENT SLOWLY RELAXES DURING THE AFTERNOON HOURS. THIS ALONG WITH DECENT MIXING IN THE LOWER LEVEL WILL ALLOW FOR GUSTY SOUTHWEST WINDS...INCLUDING GALES ON LAKE SUPERIOR AND LAKE MICHIGAN. ADDITIONALLY...THE LOW PRESSURE SYSTEM HAS A WEAK TRAILING COLD FRONT STRETCHING FROM HUDSON BAY TO NEAR THE ARROWHEAD OF MINNESOTA MONDAY MORNING. THIS FRONT WILL BECOME MORE ENE TO WSW ORIENTED ACROSS THE AREA BEFORE QUICKLY SLIDING TO THE SOUTH AND EAST OF THE AREA MONDAY NIGHT. THERE MAY BE A FEW RAIN SHOWERS ALONG THE COLD FRONT BUT MOISTURE LOOKS TO BE FAIRLY LIMITED AT THIS POINT AND FORCING LOOKS TO BE FAIRLY WEAK. HAVE ONLY KEPT ISOLATED RAIN SHOWERS IN THE FORECAST FOR MONDAY. BEHIND THE COLD FRONT...A SURFACE RIDGE...ZONAL TO SLIGHT UPPER LEVEL 500MB RIDGING AND DRY AIR WILL BUILD INTO THE AREA LATE MONDAY NIGHT AND LINGER THROUGH MUCH OF THE DAY TUESDAY BRINGING WARMER TEMPERATURES AND AN END TO ANY ISOLATED SHOWERS THAT MAY DEVELOP MONDAY. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AS THE AFOREMENTIONED HIGH PRESSURE SYSTEM SLIDES TO THE EAST OF THE AREA...A FAIRLY STRONG SHORTWAVE AND SURFACE LOW DEVELOPING OVER SOUTHERN CANADA...WILL BEGIN TO SLIDE EASTWARD TOWARD THE AREA TUESDAY NIGHT. IT LOOKS LIKE THERE WILL BE ANOTHER...WEAKER...SHORTWAVE THAT SLIDES IN AHEAD OF THE MAIN SHORTWAVE WHICH COULD HELP TO KICK UP SCATTERED RAIN SHOWERS TUESDAY NIGHT...HOWEVER...THE BETTER FORCING WILL BE WITH THE MUCH STRONGER SHORTWAVE PROGGED TO SLIDE ACROSS LAKE SUPERIOR AND MUCH OF THE U.P. WEDNESDAY INTO WEDNESDAY NIGHT. THURSDAY THROUGH THE EXTENDED...CONTINUED TO USE A CONSENSUS OF THE MODELS THROUGH THIS TIME PERIOD. THE GENERAL TREND IS FOR A SURFACE RIDGE AND ASSOCIATED UPPER LEVEL RIDGE TO BUILD INTO THE AREA THURSDAY AND LINGER THROUGH THURSDAY NIGHT. THERE ARE SOME MODEL DISAGREEMENTS BEYOND THAT. FRIDAY THE NEXT LOW PRESSURE SYSTEM...DEVELOPING OVER THE PLAINS IS PROGGED TO PROGRESS SLOWLY TOWARD THE EAST. THE GFS...AS IS TYPICAL FOR THIS TIME OF YEAR...RUSHES THE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT EASTWARD. THIS SOLUTION WOULD BRING PRECIPITATION INTO THE U.P. FRIDAY AND RUSH IT OUT OF THE AREA BY SATURDAY MORNING. THE EC...IS LESS PROGRESSIVE WITH THIS SYSTEM...WHICH KEEP THE HIGH PRESSURE IN PLACE A BIT LONGER...KEEPING CONDITIONS DRY THROUGH FRIDAY AFTERNOON. THE RAIN SHOWERS WITH THE EC SOLUTION WOULD THEN LINGER THROUGH SATURDAY. THE REDUCED CONFIDENCE IN ANY ONE PARTICULAR MODEL HAS LEANED THE FORECAST MORE TOWARD THE CONSENSUS OF THE MODELS WHICH KEEPS CHANCE POPS IN THE FORECAST FRIDAY THROUGH SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 744 AM EDT SUN OCT 18 2015 VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD AS THE LOW LEVEL AIR MASS BECOMES QUITE DRY. THERE WILL BE A PERIOD OF BKN MID LEVEL CLOUDS AT KCMX/KSAW THIS MORNING INTO THE EARLY AFTN. OTHERWISE...WITH SFC HIGH PRES RIDGE SHIFTING ACROSS THE TERMINALS...WINDS WILL BE LIGHT THIS MORNING INTO EARLY AFTN. PRES GRADIENT WILL THEN RAPIDLY TIGHTEN AS THE RIDGE SHIFTS E OF THE TERMINALS...LEADING TO INCREASING SOUTHERLY WINDS WITH SOME GUSTINESS AT KIWD/KSAW. LOW-LEVEL JET WILL DEVELOP OVERTOP NOCTURNAL INVERSION TONIGHT...RESULTING IN LLWS AT KCMX/KSAW. WITH LOW-LEVEL WINDS LIKELY REMAINING MORE MIXED/GUSTY AT KIWD...LLWS WAS NOT INCLUDED AT THAT TERMINAL. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 523 AM EDT SUN OCT 18 2015 HIGH PRES RIDGE WILL QUICKLY SHIFT ACROSS LAKE SUPERIOR TODAY... RESULTING IN A BRIEF PERIOD OF LIGHT WINDS. ALREADY IN THE AFTN... TIGHTENING PRES GRADIENT BEHIND THE RIDGE WILL LEAD TO INCREASING S WINDS...GUSTING TO 20-25KT BY LATE AFTN. WINDS INCREASE FURTHER TONIGHT AS A DEEP LOW TRACKS E OVER HUDSON BAY. WITH AN AREA OF MAX PRES FALLS PASSING N OF THE LAKE...S TO SW WINDS WILL LIKELY REACH GALE FORCE...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW...AND OVER THE EASTERN PART OF THE LAKE WHERE THIS TYPE OF PATTERN TYPICALLY PRODUCES THE STRONGEST WINDS. THE HIGHEST OBS PLATFORMS WILL PROBABLY SEE WIND GUSTS IN EXCESS OF 40KT FOR A TIME. WINDS WILL DIMINISH TO UNDER 25KT W TO E ON MON. AFTER A TROF PASSES LATE MON AFTN AND EVENING...N TO NE WINDS WILL INCREASE TO 20-30KT OVER MUCH OF THE LAKE AHEAD OF HIGH PRES THAT WILL BUILD SE INTO NRN ONTARIO TUE. WINDS WILL THEN VEER TO THE E-SE TUE NIGHT/WED AS THE HIGH MOVES INTO QUEBEC AND A LOW PRES TROF APPROACHES. AFTER THE TROF PASSES...WINDS WILL FINALLY DIMINISH LATER THU WHEN HIGH PRES BUILDS INTO THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 11 AM EDT MONDAY FOR LSZ266-267. GALE WARNING FROM 11 PM THIS EVENING TO 8 AM EDT MONDAY FOR LSZ263-264. LAKE MICHIGAN... GALE WARNING FROM 1 AM TO 2 PM EDT MONDAY FOR LMZ221-248-250. && $$ SHORT TERM...ROLFSON LONG TERM...KEC AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
650 AM CDT SUN OCT 18 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT SUN OCT 18 2015 BIGGEST CONCERN IN THE SHORT TERM DEALS WITH FIRE WEATHER TODAY...WITH WEST CENTRAL INTO SOUTH CENTRAL MN EXPECTED TO FLIRT WITH RED FLAG WARNING CRITERIA. SFC RIDGE TONIGHT IS CENTERED OVER WI...WITH SE RETURN FLOW QUICKLY BECOMING ESTABLISHED ACROSS MN. THE MAIN THEME FOR TODAY WILL BE STRONG WAA...AS H85 TEMPS WILL BE WARMING ABOUT 10C OVER WHAT WE SAW YESTERDAY. THERE IS GOOD VISUAL EVIDENCE OF SAID WARM ADVECTION IN THE FORM OF A BANK OF 6K-8K FT CLOUDS THAT HAVE FORMED OVER SRN MN THIS MORNING. RAP 750MB RH ALONG WITH THE CLOUD FORECAST FROM THE HRRR EVENTUALLY LATCHED ON TO THIS CLOUD COVER AND FOLLOWED THESE MODEL FEATURES TO PUSH THAT AREA OF CLOUDS EAST ACROSS SRN MN INTO WI THIS MORNING. BY THE AFTERNOON...THESE CLOUDS WILL BE EAST OF THE MPX CWA AND OUR SKIES WILL REMAIN MAINLY CLEAR UNTIL UPPER LEVEL CLOUDS CURRENTLY OVER CO/WY GET HERE TONIGHT. THOUGH H85 TEMPS ARE WARMING 10C...WE WILL NOT BE MIXING THAT DEEP...WITH NAM/RAP SOUNDINGS SHOWING THE BOUNDARY LAYER BUILDING TO ABOUT 900 MB. MIXING TO THIS LEVEL PRODUCED HIGHS SIMILAR TO WHAT WE HAD GOING...WITH UPPER 60S IN WRN MN AND UPPER 50S IN WRN WI. THESE WARM TEMPERATURES COMBINED WITH DEWPS THIS MORNING IN THE 20S WOULD PRODUCE HUMIDITIES UNDER 25 PERCENT...BUT THE GFS/NAM BOTH SUPPORT DEEP ENOUGH MOISTURE ARRIVING WITH THE SE WINDS TO HELP PUSH DEWPS THIS AFTERNOON UP INTO THE LOWER/MIDDLE 30S IN SOUTHERN/WESTERN MN...WHICH IS JUST ENOUGH TO KEEP AFTERNOON HUMIDITIES ABOUT THE 25 PERCENT THRESHOLD FOR A RFW. STILL...WITH HUMIDITIES LIKELY DROPPING UNDER 30 PERCENT ALONG WITH SE WINDS INCREASING TO BETWEEN 20 AND 25 MPH WITH GUSTS TO AROUND 30 MPH...WILL CONTINUE TO HEADLINE THE INCREASED FIRE WEATHER THREAT IN THE FIRE WEATHER PLANNING FORECAST. TONIGHT...SHORTWAVE ENERGY CURRENTLY OVER CO/WY WILL FLATTEN OUT THE UPPER RIDGE MOVING OVERHEAD TODAY AND BRING A SLUG OF UPPER LEVEL MOISTURE WITH AS WELL. HOWEVER...RH TIME-HEIGHT CROSS SECTIONS SHOW THIS MOISTURE ONLY GETTING DOWN TO ABOUT 15K FT...SO NOT CONCERNED ABOUT ANY PRECIP. HOWEVER...THESE CLOUDS ALONG WITH SOUTHERLY WINDS REMAINING UP OVERNIGHT WILL RESULT IN A VERY MILD NIGHT TONIGHT...WITH MUCH OF THE MN CWA SOUTH OF I-94 STAYING UP IN THE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN OCT 18 2015 THE LONG TERM STILL LOOKS TO START OUT ON A WARM NOTE MONDAY WITH HIGHS AROUND 15 TO 20 DEGREES ABOVE CLIMATOLOGICAL NORMALS. MEANWHILE...PRECIPITATION CHANCES CONTINUE TO WANE UNTIL CLOSER TO THE END OF THE WEEK. THE SURFACE COLD FRONT STILL LOOKS TO BE ON OUR WESTERN DOORSTEP AT DAYBREAK MONDAY. FAVORABLE SOUTHWEST FLOW FOR WARMING WILL ENSUE THROUGH MIDDAY ACROSS MUCH OF CENTRAL AND SOUTH CENTRAL MN. H85 TEMPS IN THE UPPER TEENS /CELSIUS/ SHOULD YIELD UPPER 70S TO NEAR 80 DEGREES OVER SOUTHWEST/SOUTH CENTRAL MN...WITH LOW/MID 70S ACROSS THE REMAINDER OF THE AREA. AT THIS POINT THE PROGGED MOISTURE IS HARDLY SUFFICIENT TO GENERATE MUCH MORE THAN BROKEN MID LEVEL CLOUD COVER ACROSS CENTRAL MN/WI...WITH VIRTUALLY NO FORCING TO MENTION. HAVE THEREFORE REMOVED POPS FOR MONDAY. TUESDAY AN INVERTED TROUGH NOSES INTO THE REGION...ALTHOUGH MODELS ARE STILL ALL OVER THE MAP WITH REGARD TO POSITIONING. TWO AREAS OF PRECIPITATION LOOK TO UNFOLD...WITH MODELS HINTING THE FORECAST AREA COULD LARGELY BE PLACED BETWEEN SAID AREAS. HAVE INCLUDED 20-30 POPS FOR TUESDAY/WEDNESDAY...BUT ACTIVITY LOOKS AS IF IT WOULD BE SCATTERED AT BEST WITH LOW PRECIP AMOUNTS. WEDNESDAY NIGHT AND THURSDAY FLEETING SURFACE HIGH PRESSURE MOVES ACROSS THE AREA...BUT THEN A STRONGER TROUGH WITH A NICE FETCH OF MOISTURE ADVECTION LIFTS INTO THE AREA FOR FRIDAY. HAVE INCLUDED 40-50 POPS FOR FRIDAY AND FRIDAY NIGHT...DRYING OUT FOR SATURDAY. HIGH TEMPERATURES FROM TUESDAY THROUGH THE LONG TERM FORECAST PERIOD LOOK TO RUN AROUND 5 TO 10 DEGREES ABOVE NORMAL...WITH LOWS EVEN WARMER IN THE 10 TO 15 DEGREES ABOVE NORMAL RANGE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 650 AM CDT SUN OCT 18 2015 ONLY CHANGES MADE TO EXISTING TAFS WAS TO ADD A BRIEF FOG MENTION AT EAU THIS MORNING AND ADD IN WIND SHEAR FOR TONIGHT. FOR EAU...THIS IS SIMPLY YOUR RADIATIVE COOLING RIVER FOG. 1330 IS PROBABLY A LITTLE TOO LONG TO HOLD THE FOG...BUT WILL KEEP US FROM HAVING TO CHASE THE IMPROVEMENT. TONIGHT...WE WILL SEE A 55-60KT LLJ CENTERED AT ABOUT 2500 FEET MOVE UP FROM SW MN TOWARD NW WI. DIRECTIONAL SHEAR WITH THE JET IS NOT ALL THAT GREAT...BUT THE SPEED SHEAR NEAR THE NOSE OF THE NOCTURNAL INVERSION WILL BE QUITE STRONG...SO ADDED WIND SHEAR TO ALL BUT STC/AXN AS THE CORE OF THE LLJ LOOKS TO COME IN EAST OF THESE LOCATIONS. KMSP...7K FT CIGS SOUTH OF THE FIELD LOOK TO STAY SOUTH OF MSP...THOUGH A STRAY CLOUD UP AROUND THIS LEVEL THROUGH THE MORNING CAN NOT BE RULED OUT. BOTH THE GFS/NAM SHOW A STRONG JET DEVELOPING AT THE NOSE OF THE LLJ TONIGHT...SO FELT COMFORTABLE WITH GOING WITH THE WIND SHEAR MENTION THIS FAR OUT. /OUTLOOK FOR KMSP/ MON...VFR. WINDS SW 15G25KTS TUE...VFR. WINDS NE/E 5-10KTS. WED...VFR. CHC MRNG SHRA. WINDS E BCMG NW 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...LS AVIATION...MPG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
955 AM CDT SUN OCT 18 2015 .UPDATE... ISSUED AT 943 AM CDT SUN OCT 18 2015 LATEST WV LOOP SHOWS UPPER LOW MOVING ONTO THE NORTHERN CALIFORNIA COAST. LEAD SHORTWAVE ENERGY IS LIFTING THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN HIGH PLAINS. UPPER LEVEL RIDGING REMAINS OVER WESTERN AND CENTRAL NORTH DAKOTA...BUT WILL FLATTEN DURING THE DAY DUE TO AFOREMENTIONED SHORTWAVE ENERGY...AND ANOTHER NORTHERN STREAM WAVE. BREEZY EAST TODAY BUT OVERALL QUIET WITH SOME INCREASING MID AND HIGH LEVEL CLOUDS WEST. SUNNY EAST. FOR THE MORNING UPDATE...INCREASED CLOUDS AND MINIMAL POPS WEST FOR TONIGHT. MESOSCALE MODELS AND THE ECMWF BRING INCREASING MID LEVEL MOISTURE INTO WESTERN NORTH DAKOTA...AND LAST FEW ITERATIONS OF THE HRRR HAVE BROUGHT SOME LIGHT QPF THROUGH NORTHEAST MONTANA. WILL KEEP AN EYE ON HOW THINGS TREND THROUGH THE DAY BUT FOR NOW DID NOT BRING ANY MENTION OF PRECIP INTO THE WORDED FORECAST IN THE WEST TONIGHT AS ATMOSPHERE BELOW THIS MID LEVEL MOISTURE REMAIN QUITE DRY. UPDATE ISSUED AT 636 AM CDT SUN OCT 18 2015 FORECAST ON TRACK. HOURLY TEMPS WERE A LITTLE TOO HIGH ACROSS SOME AREAS...THEREFORE BLENDED FORECAST TO CURRENT OBSERVATIONS. OTHERWISE...NO CHANGES MADE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 301 AM CDT SUN OCT 18 2015 SURFACE HIGH PRESSURE WILL CONTINUE TO DRIFT AWAY FROM THE FORECAST AREA TODAY...TO THE SOUTHEAST...WHILE A LEE SIDE TROUGH THROUGH EASTERN MONTANA PUSHES THROUGH WILLISTON AND DICKINSON BY SUNSET. THIS RESULTS IN SOUTHEAST SURFACE WINDS. MID LEVEL SUPPORT WAS VERY WEAK AND WITH A LACK OF LOW LEVEL MOISTURE THE TROUGH PASSAGE IS FORECAST TO BE DRY. HIGH TEMPERATURES TODAY WILL BE 10 DEGREES ABOVE MID OCTOBER NORMALS OVER THE JAMES RIVER VALLEY TO 20 DEGREES ABOVE NORMAL AT HETTINGER. A GUSTY SOUTHEAST WIND AHEAD OF THE TROUGH...WITH HIGHEST WIND SPEEDS THROUGH THE JAMES RIVER VALLEY...WILL REMAIN BELOW WIND ADVISORY CRITERIA. HIGHER HUMIDITY THROUGH THE JAMES VALLEY WILL ACT TO DAMPEN FIRE WEATHER CONCERNS TODAY. THE DRY TROUGH PASSES THROUGH THE REST OF THE FORECAST AREA TONIGHT WITH PARTLY CLOUDY SKIES. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 301 AM CDT SUN OCT 18 2015 00Z GFS/ECMWF/CANADIAN MODELS ARE IN DECENT AGREEMENT EARLY IN THE PERIOD SHOWING A MORE ACTIVE WEEK SETTING UP WITH THE FIRST CHANCE OF PRECIP MONDAY NIGHT THROUGH TUESDAY WITH OUR REGION IN SOUTHWEST FLOW AHEAD OF LONGWAVE TROUGH ACROSS INTERMOUNTAIN WEST EARLY IN THE WEEK. FORECAST CONTINUES WITH MAINLY CHANCE POPS FOR THIS SYSTEM. NEXT SYSTEM APPROACHES THE NORTHERN PLAINS ON THURSDAY WITH MODELS SHOWING MORE SIGNIFICANT DIFFERENCES. OPERATIONAL GFS IS MUCH FASTER WITH THIS SYSTEM AND FARTHER NORTH WITH SURFACE LOW COMPARED TO GFS ENSEMBLES AND ECMWF. GFS HAS PRECIP EAST OF NORTH DAKOTA EARLY FRIDAY WHILE ECMWF/CANADIAN MODELS HOLD PRECIP ACROSS THE STATE FOR MUCH OF THE DAY. FORECAST LEANS MORE TOWARD THE SLOWER SOLUTIONS AND MAINTAINS PRECIP THROUGH FRIDAY. WITH REGARD TO TEMPERATURES...EXPECT THEM TO CONTINUE TO RUN NEAR/ABOVE NORMAL WITH HIGHS MAINLY IN THE 50 AND SOME LOW 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 943 AM CDT SUN OCT 18 2015 A DRY TROUGH OF LOW PRESSURE WILL MOVE OUT OF MONTANA AND ACROSS NORTH DAKOTA DURING THE TAF VALID PERIOD. VFR WEATHER AT ALL TAF SITES. DURING THE DAYLIGHT HOURS SUNDAY...AHEAD OF THE TROUGH...SOUTHEAST SURFACE WINDS WILL GUST TO 25 KNOTS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...JPM LONG TERM...JNS AVIATION...TWH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST SUN OCT 18 2015 .SYNOPSIS...EXPECT LESS SHOWER AND THUNDERSTORM ACTIVITY INTO MONDAY. A LOW PRESSURE SYSTEM WILL THEN BRING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY. A DRYING TREND WILL START THURSDAY...THEN DRY CONDITIONS WILL OCCUR FRIDAY INTO SATURDAY. && .DISCUSSION...SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE PARTLY CLOUDY TO MOSTLY CLOUDY SKIES ACROSS SE ARIZONA AT THIS TIME. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z WERE IN THE MID TO UPPER 50S...AND THESE TEMPS WERE GENERALLY UNCHANGED VERSUS 24 HOURS AGO. SURFACE TEMPS VALID 16Z WERE NEARLY 3-8 DEGS F WARMER VERSUS THIS TIME SAT. 18/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 1.02 INCHES...AND THIS VALUE WAS 0.12 INCH LOWER VERSUS 24 HOURS AGO. THE ENVIRONMENT WAS MARGINALLY UNSTABLE WITH MUCAPE OF 584 J/KG AND LIFTED INDEX OF MINUS 2. 18/12Z UPPER AIR PLOTS DEPICTED A TROUGH OVER THE WRN CONUS WITH LOW PRESSURE CENTERED OVER NRN CALIFORNIA... AND A NORTH-TO-SOUTH RIDGE OVER THE CENTRAL CONUS PLAINS. IR/WATER VAPOR SATELLITE IMAGERY ALSO DEPICTED THE BACK EDGE OF MAINLY MID AND HIGH-LEVEL CLOUDS REPRESENTING A SHORTWAVE TROUGH ALONG THE WEST COAST OF NRN/CENTRAL BAJA CALIFORNIA. LIGHT TO MODERATE SWLY/WLY FLOW ABOVE 700 MB PREVAILED ACROSS SE ARIZONA. 18/12Z NAM12...18/06Z UNIV OF ARIZONA WRF-NAM AND WRF-GFS AND SEVERAL HRRR SOLUTIONS SUGGEST THAT THE FAVORED LOCALES FOR SHOWERS/ TSTMS INTO THIS EVENING WILL GENERALLY OCCUR NORTH-TO-NORTHEAST OF TUCSON...OR ACROSS SE PINAL/GRAHAM/NRN GREENLEE COUNTIES. THE INHERITED OFFICIAL FORECAST REFLECTS THIS NOTION...WITH CHANCE- CATEGORY POPS ACROSS THIS AREA. THERE IS ENOUGH MOISTURE TO ALSO SUPPORT AT LEAST ISOLATED COVERAGE OF SHOWERS/TSTMS FROM THE TOHONO O`ODHAM NATION EWD INTO COCHISE COUNTY. PRECIP-FREE CONDITIONS SHOULD OCCUR INTO THIS EVENING ACROSS WRN PIMA COUNTY. HOWEVER... BASED ON SATELLITE TRENDS AS WELL AS THE 500-300 MB GFS MOISTURE FIELDS...THE CIRRIFORM CLOUDS APPROACHING FROM THE SOUTHWEST MAY BECOME FAIRLY THICK THIS AFTERNOON AND EVENING...ESPECIALLY WEST OF TUCSON. HIGH TEMPS THIS AFTERNOON WILL AVERAGE A FEW DEGS ABOVE NORMAL. THERE ARE NO UPDATES PLANNED AT THIS TIME. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 19/18Z. SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY NORTH-TO-NORTHEAST ACROSS SE PINAL COUNTY TO THE WHITE MOUNTAINS NE OF KSAD THRU TONIGHT. ISOLATED -SHRA/-TSRA MAY OCCUR MAINLY EAST OF KTUS MONDAY MORNING. MVFR CONDITIONS WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE...SCATTERED TO BROKEN CLOUDS AROUND 8-12K FT AGL AND BROKEN TO OVERCAST CLOUDS ABOVE 20K FT AGL WILL PREVAIL INTO MONDAY MORNING. SURFACE WIND TODAY WILL GENERALLY BE SELY TO SWLY AT 5-15 KTS WITH GUSTS TO 20 KTS. SURFACE WIND WILL BE LESS THAN 10 KTS THIS EVENING INTO MONDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY MAINLY NORTH TO NORTHEAST OF TUCSON FOLLOWED BY A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF TUCSON MONDAY. A LOW PRESSURE SYSTEM WILL THEN BRING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY. A DRYING TREND WILL START THURSDAY...THEN DRY CONDITIONS FRIDAY INTO SATURDAY. && .PREV DISCUSSION /312 AM MST/...MODELS SHOWED A BREAK IN THE RAINY WEATHER MONDAY BEFORE ANOTHER SYSTEM EVOLVES OVER SOUTHERN CALIFORNIA AND TRACKS EASTWARD THROUGH AZ ON TUESDAY INTO LATE WEDNESDAY. THIS WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO MUCH OF THE AREA. UNTIL THEN...JUST EXPECTING SPOTTY SHOWERS AND A STRAY THUNDERSTORM OR TWO. GFS AND ECMWF MODELS STILL SHOWED A VERY PROGRESSIVE PATTERN IN PLACE THIS WEEK AS ANOTHER SYSTEM DEVELOPS NEAR THE REGION AROUND THE WEEKEND. HIGH TEMPERATURES TODAY AND MONDAY WILL REMAIN A FEW DEGREES ABOVE NORMAL...THEN BELOW NORMAL DAYTIME READINGS WILL PREVAIL TUESDAY THROUGH THURSDAY. HIGHS WILL TEND TO BE CLOSER TO SEASONAL NORMALS BY NEXT WEEKEND. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
433 PM MDT SUN OCT 18 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 117 PM MDT SUN OCT 18 2015 WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE CENTERED OVER SOUTHERN PLAINS AND CLOSED LOW CENTERED OVER NORTHERN CALIFORNIA. A UPPER LEVEL SHORTWAVE TROUGH CURRENTLY EXTENDS FROM THE NEBRASKA PANHANDLE AND ALONG CO/KS BORDER. AT THE SURFACE LEE TROUGH HAS DEEPENED ACROSS EASTERN COLORADO WITH SW GRADIENT ACROSS OUR CWA. A WARM FRONT HAS LIFTED NORTH OF KMCK AND TEMPS ACROSS THE REGION HAVE WARMED INTO THE UPPER 70S/LOWER 80S EARLY THIS AFTERNOON. TONIGHT-MONDAY...WEAK FORCING ASSOCIATED WITH SEVERAL PASSING UPPER LEVEL SHORTWAVE TROUGHS WILL RESULT IN PASSING HIGH CLOUD COVER AND LITTLE ELSE. GFS DOES SHOW A LITTLE BETTER MID LEVEL MOISTURE ADVECTION AND A SMALL AREA OF LIGHT QPF ACROSS OUR NORTH. DRY MOISTURE PROFILES BELOW THESE ELEVATED MOIST LAYER EVEN WITH GFS WOULD LIKELY BE TOO MUCH TO OVERCOME AND PRECIP IS NOT EXPECTED. LEE TROUGH WILL SHIFT EASTWARD IN RESPONSE TO DEEPENING TROUGH IN THE WEST AND SHIFT TO SW FLOW ALOFT. GRADIENT WILL WEAKEN AS A RESULT AND WINDS SHOULD BE CONSIDERABLY LIGHTER COMPARED TO TODAY. A VERY SIMILAR AIR MASS WILL BE IN PLACE AND ABOVE NORMAL HIGHS IN THE LOWER 80S TO MID 80S ARE EXPECTED. THE MAIN COMPLICATION WILL BE THICKNESS/COVERAGE OF MID TO HIGH CLOUD COVER. CLOUD COVER APPEARS TO BE FAIRLY PROGRESSIVE WITHIN SW FLOW...SO AT THIS TIME ANTICIPATED IMPACT ON HIGHS SHOULD BE MINIMAL. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 118 PM MDT SUN OCT 18 2015 SOUTHWESTERLY FLOW ALOFT AHEAD OF THE CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL CONTINUE THROUGH WEDNESDAY BEFORE IT FINALLY LIFTS OUT AND ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY. RAIN CHANCES WILL GRADUALLY INCREASE AHEAD OF THE MAIN SYSTEM WITH THE BEST CHANCES FOR RAIN OCCURRING WEDNESDAY NIGHT THROUGH THE DAY ON THURSDAY. 48-HOUR QPF TOTALS ENDING AT 12Z FRIDAY ARE ACTUALLY QUITE SIMILAR FROM THE GFS AND ECMWF...WITH 1 TO 2 INCHES FORECAST SOUTH OF INTERSTATE 70 AND 0.50 TO 1 INCH GENERALLY NORTH OF THE INTERSTATE. A FAVORABLE TROPICAL MOISTURE FETCH IN MID LEVELS AND GOOD MOISTURE ADVECTION FROM THE SOUTHEAST IN THE LOWER LEVELS RESULT IN PRECIPITABLE WATER VALUES APPROACHING 200 PERCENT OF NORMAL LEADING UP TO THE ARRIVAL OF THE SYSTEM. RAIN WILL GRADUALLY END WEST TO EAST ON FRIDAY. TEMPERATURES WILL BE ABOVE NORMAL TUESDAY...NEAR NORMAL ON WEDNESDAY...BELOW NORMAL ON THURSDAY THEN NEAR TO SLIGHTLY BELOW NORMAL FRIDAY THROUGH SUNDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 429 PM MDT SUN OCT 18 2015 VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS. BREEZY SOUTH WINDS WILL PERSIST TONIGHT WITH SOME LOW LEVEL WIND SHEAR AT KMCK. WINDS DECREASE MONDAY AS THE SURFACE TROUGH MOVES EAST NEAR KGLD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
137 PM MDT SUN OCT 18 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 117 PM MDT SUN OCT 18 2015 WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE CENTERED OVER SOUTHERN PLAINS AND CLOSED LOW CENTERED OVER NORTHERN CALIFORNIA. A UPPER LEVEL SHORTWAVE TROUGH CURRENTLY EXTENDS FROM THE NEBRASKA PANHANDLE AND ALONG CO/KS BORDER. AT THE SURFACE LEE TROUGH HAS DEEPENED ACROSS EASTERN COLORADO WITH SW GRADIENT ACROSS OUR CWA. A WARM FRONT HAS LIFTED NORTH OF KMCK AND TEMPS ACROSS THE REGION HAVE WARMED INTO THE UPPER 70S/LOWER 80S EARLY THIS AFTERNOON. TONIGHT-MONDAY...WEAK FORCING ASSOCIATED WITH SEVERAL PASSING UPPER LEVEL SHORTWAVE TROUGHS WILL RESULT IN PASSING HIGH CLOUD COVER AND LITTLE ELSE. GFS DOES SHOW A LITTLE BETTER MID LEVEL MOISTURE ADVECTION AND A SMALL AREA OF LIGHT QPF ACROSS OUR NORTH. DRY MOISTURE PROFILES BELOW THESE ELEVATED MOIST LAYER EVEN WITH GFS WOULD LIKELY BE TOO MUCH TO OVERCOME AND PRECIP IS NOT EXPECTED. LEE TROUGH WILL SHIFT EASTWARD IN RESPONSE TO DEEPENING TROUGH IN THE WEST AND SHIFT TO SW FLOW ALOFT. GRADIENT WILL WEAKEN AS A RESULT AND WINDS SHOULD BE CONSIDERABLY LIGHTER COMPARED TO TODAY. A VERY SIMILAR AIR MASS WILL BE IN PLACE AND ABOVE NORMAL HIGHS IN THE LOWER 80S TO MID 80S ARE EXPECTED. THE MAIN COMPLICATION WILL BE THICKNESS/COVERAGE OF MID TO HIGH CLOUD COVER. CLOUD COVER APPEARS TO BE FAIRLY PROGRESSIVE WITHIN SW FLOW...SO AT THIS TIME ANTICIPATED IMPACT ON HIGHS SHOULD BE MINIMAL. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 118 PM MDT SUN OCT 18 2015 SOUTHWESTERLY FLOW ALOFT AHEAD OF THE CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL CONTINUE THROUGH WEDNESDAY BEFORE IT FINALLY LIFTS OUT AND ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY. RAIN CHANCES WILL GRADUALLY INCREASE AHEAD OF THE MAIN SYSTEM WITH THE BEST CHANCES FOR RAIN OCCURRING WEDNESDAY NIGHT THROUGH THE DAY ON THURSDAY. 48-HOUR QPF TOTALS ENDING AT 12Z FRIDAY ARE ACTUALLY QUITE SIMILAR FROM THE GFS AND ECMWF...WITH 1 TO 2 INCHES FORECAST SOUTH OF INTERSTATE 70 AND 0.50 TO 1 INCH GENERALLY NORTH OF THE INTERSTATE. A FAVORABLE TROPICAL MOISTURE FETCH IN MID LEVELS AND GOOD MOISTURE ADVECTION FROM THE SOUTHEAST IN THE LOWER LEVELS RESULT IN PRECIPITABLE WATER VALUES APPROACHING 200 PERCENT OF NORMAL LEADING UP TO THE ARRIVAL OF THE SYSTEM. RAIN WILL GRADUALLY END WEST TO EAST ON FRIDAY. TEMPERATURES WILL BE ABOVE NORMAL TUESDAY...NEAR NORMAL ON WEDNESDAY...BELOW NORMAL ON THURSDAY THEN NEAR TO SLIGHTLY BELOW NORMAL FRIDAY THROUGH SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1121 AM MDT SUN OCT 18 2015 VFR CONDITIONS WILL CONTINUE AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. TIGHT SURFACE GRADIENT IS IN PLACE OVER KGLD EAST OF DEEPENING SURFACE LOW OVER EASTERN COLORADO. AS WARM FRONT OVER KMCK LIFTS NORTH SOUTHERLY GRADIENT WILL MOVE OVER KMCK TERMINAL AS WELL (WITHIN THE NEXT HOUR). RESULT WILL BE GUSTY WINDS WITH GUSTS AROUND 30KT...POSSIBLY AS HIGH AS 35 KT THIS AFTERNOON. PEAK WIND GUSTS WILL END WITH LOSS OF DAYTIME HEATING AT SUNSET...HOWEVER WITH LOW LEVEL JET LINGERING THROUGH THE NIGHT OVER KMCK I WOULD EXPECT LOW LEVEL WIND SHEER TO DEVELOP. THIS WOULD THEN LAST THROUGH AROUND 8Z WHEN THE LLJ FINALLY TRANSITIONS EAST. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
117 PM MDT SUN OCT 18 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 117 PM MDT SUN OCT 18 2015 WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE CENTERED OVER SOUTHERN PLAINS AND CLOSED LOW CENTERED OVER NORTHERN CALIFORNIA. A UPPER LEVEL SHORTWAVE TROUGH CURRENTLY EXTENDS FROM THE NEBRASKA PANHANDLE AND ALONG CO/KS BORDER. AT THE SURFACE LEE TROUGH HAS DEEPENED ACROSS EASTERN COLORADO WITH SW GRADIENT ACROSS OUR CWA. A WARM FRONT HAS LIFTED NORTH OF KMCK AND TEMPS ACROSS THE REGION HAVE WARMED INTO THE UPPER 70S/LOWER 80S EARLY THIS AFTERNOON. TONIGHT-MONDAY...WEAK FORCING ASSOCIATED WITH SEVERAL PASSING UPPER LEVEL SHORTWAVE TROUGHS WILL RESULT IN PASSING HIGH CLOUD COVER AND LITTLE ELSE. GFS DOES SHOW A LITTLE BETTER MID LEVEL MOISTURE ADVECTION AND A SMALL AREA OF LIGHT QPF ACROSS OUR NORTH. DRY MOISTURE PROFILES BELOW THESE ELEVATED MOIST LAYER EVEN WITH GFS WOULD LIKELY BE TOO MUCH TO OVERCOME AND PRECIP IS NOT EXPECTED. LEE TROUGH WILL SHIFT EASTWARD IN RESPONSE TO DEEPENING TROUGH IN THE WEST AND SHIFT TO SW FLOW ALOFT. GRADIENT WILL WEAKEN AS A RESULT AND WINDS SHOULD BE CONSIDERABLY LIGHTER COMPARED TO TODAY. A VERY SIMILAR AIR MASS WILL BE IN PLACE AND ABOVE NORMAL HIGHS IN THE LOWER 80S TO MID 80S ARE EXPECTED. THE MAIN COMPLICATION WILL BE THICKNESS/COVERAGE OF MID TO HIGH CLOUD COVER. CLOUD COVER APPEARS TO BE FAIRLY PROGRESSIVE WITHIN SW FLOW...SO AT THIS TIME ANTICIPATED IMPACT ON HIGHS SHOULD BE MINIMAL. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 142 AM MDT SUN OCT 18 2015 THE EXTENDED PERIOD BEGINS WITH THE APPROACH OF A CUT OFF AREA OF LOW PRESSURE AND ASSOCIATED SLIGHTLY NEGATIVE TROUGH. THIS LOW WILL MOVE NORTHEASTWARD THROUGH THE DAY ON WEDNESDAY AND INTO EARLY THURSDAY. GUIDANCE IS IN GOOD AGREEMENT WITH REGARDS TO THE LOW OPENING AND BECOMING A PART OF THE MAIN TROUGH HOWEVER TEMPORAL AGREEMENT IS WEAK. POPS ON WEDNESDAY WILL BE IN THE 30 TO 50 PERCENT RANGE NORTH TO SOUTH AS THE SOUTHERN PORTION OF THE CWA WILL HAVE SLIGHTLY BETTER OMEGA VALUES THANKS TO FAVORABLE POSITIONING OF THE JET. THIS AXIS WILL SHIFT NORTH AS WE HEAD INTO THURSDAY WITH MUCH OF THE CWA NOW POTENTIALLY SEEING 40 TO 60 PERCENT POPS ESPECIALLY DURING THE MIDDAY TO EARLY AFTERNOON HOURS. THE SYSTEM WILL SLOWLY MOVE OFF TO THE NORTH AND EAST EARLY FRIDAY WITH SHOWERS AND EMBEDDED THUNDERSTORMS TAPERING OFF FROM WEST TO EAST DURING THE DAY. THE EASTERN PORTIONS OF THE CWA WILL SEE RAIN CHANCES PERSIST INTO SATURDAY MORNING HOWEVER MOST ACTIVITY WILL WIND DOWN JUST BEFORE SUNRISE. THERE IS A POSSIBILITY FOR LOW VISIBILITIES DUE TO MIST OR FOG ON WEDNESDAY... THURSDAY AND FRIDAY MORNING DUE TO NEAR ZERO DEW POINT DEPRESSIONS AND A FAVORABLE WIND STRUCTURE. TEMPERATURES DURING THE FORECAST PERIOD WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE WITH HIGHS IN THE LOWER 60S AND LOWS IN THE LOW TO MID 40S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1121 AM MDT SUN OCT 18 2015 VFR CONDITIONS WILL CONTINUE AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. TIGHT SURFACE GRADIENT IS IN PLACE OVER KGLD EAST OF DEEPENING SURFACE LOW OVER EASTERN COLORADO. AS WARM FRONT OVER KMCK LIFTS NORTH SOUTHERLY GRADIENT WILL MOVE OVER KMCK TERMINAL AS WELL (WITHIN THE NEXT HOUR). RESULT WILL BE GUSTY WINDS WITH GUSTS AROUND 30KT...POSSIBLY AS HIGH AS 35 KT THIS AFTERNOON. PEAK WIND GUSTS WILL END WITH LOSS OF DAYTIME HEATING AT SUNSET...HOWEVER WITH LOW LEVEL JET LINGERING THROUGH THE NIGHT OVER KMCK I WOULD EXPECT LOW LEVEL WIND SHEER TO DEVELOP. THIS WOULD THEN LAST THROUGH AROUND 8Z WHEN THE LLJ FINALLY TRANSITIONS EAST. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...TL AVIATION...DR
AREA FORECAST DISCUSSION
NWS JACKSON KY
310 PM EDT SUN OCT 18 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 310 PM EDT SUN OCT 18 2015 18Z SFC ANALYSIS SHOWS HIGH PRESSURE SETTLING INTO THE OHIO VALLEY AND KENTUCKY. THIS HAS KEPT THE CLOUDS AT BAY TODAY AND ALSO THE WINDS LIGHT. THE DRIER AIR ALOFT DID MIX DOWN BETTER THIS AFTERNOON THAN YESTERDAY WITH READINGS FALLING INTO THE LOWER AND MIDDLE 20S. WHEN COMBINED WITH TEMPERATURES GENERALLY IN THE MID AND UPPER 50S RH VALUES HAVE FALLEN INTO THE LOW 30S FOR MUCH OF THE AREA. THE DRY AIR WILL ALSO SERVE WELL FOR A QUICK TEMPERATURE DROP OFF THIS EVENING...ESPECIALLY IN THE VALLEYS. THE MODELS CONTINUE TO BE IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT TERM AS A BROAD AND FLATTENING RIDGE EASES INTO THE REGION IN THE WAKE OF THE TROUGH CROSSING THE NORTHEAST. SOME WEAK ENERGY WILL DRIFT THROUGH THE AREA ON MONDAY...BUT IN A RISING HEIGHT ENVIRONMENT THIS WILL BE NEGLIGIBLE. HAVE FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX DETAILS GIVEN THE MODEL AGREEMENT WHILE ALSO FAVORING THE GFS CO-OP MOS...TO A CERTAIN EXTENT...FOR SITE SPECIFIC LOWS TONIGHT AND MONDAY NIGHT. SENSIBLE WEATHER WILL FEATURE ANOTHER CHILLY NIGHT WITH A LARGER RIDGE TO VALLEY SPLIT DEVELOPING AROUND SUNSET AND CONTINUING THROUGH THE NIGHT. THIS WILL RESULT IN SUB-FREEZING TEMPERATURES FOR THE VALLEYS BY DAWN ALONG WITH WIDESPREAD FROST. AS A RESULT...WE WILL CONTINUE OUR FREEZE WARNING THROUGH 9 AM MONDAY MORNING. IN ADDITION...DO ANTICIPATE ANOTHER BATCH OF PATCHY DENSE FOG ALONG THE RIVERS AND LAKES ACROSS THE CWA TOWARD DAWN. WITH THE MODERATING SFC HIGH DOMINATING THE WX SUNNY SKIES WILL BE THE RULE FOR MONDAY ALONG WITH WARMER TEMPERATURES UP INTO THE 60S FOR HIGHS. MONDAY NIGHT WILL BE MILDER AS THE HIGH STARTS TO PULL AWAY OPENING UP A LARGER RIDGE TO VALLEY SPLIT BUT ALSO TEMPERATURES 5 TO 10 DEGREES HIGHER ACROSS THE BOARD FOR LOWS. PATCHY FOG WILL ALSO BE FOUND ALONG THE RIVER VALLEYS MONDAY MORNING. STARTED WITH THE SHORTBLEND GUIDANCE FOR THE T AND TD GRIDS INTO MONDAY MORNING FOLLOWED BY THE SUPERBLEND. DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND MONDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY DIFFERENCES. AS FOR POPS...ONCE AGAIN ZEROED THEM OUT THROUGH THE SHORT TERM PERIOD...IN LINE WITH ALL GUIDANCE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 215 PM EDT SUN OCT 18 2015 HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER THROUGH THE EXTENDED PORTION OF THE FORECAST WITH NO RAIN EXPECTED. HIGHS WILL REMAIN AT OR ABOVE 70 THROUGH THE WEEK AND INTO NEXT WEEKEND. THE MAIN WEATHER IMPACT FOR THIS WEEK WILL BE THE CONTINUATION OF DRY CONDITIONS ON TUESDAY AND WEDNESDAY...WITH AFTERNOON RH VALUES FALLING TO BETWEEN 20 AND 30 PERCENT. SOME SPOTS COULD SEE RH`S INTO THE TEENS. RH WILL RECOVER SLIGHTLY ON THURSDAY. HOWEVER...AS THE RIDGE BUILDS AGAIN FRIDAY AND SATURDAY...MORE LOW RH`S COULD RETURN. WILL CONTINUE TO HIGHLIGHT THE LOW AFTERNOON RELATIVE HUMIDITIES IN THE FIRE WEATHER FORECAST. FORTUNATELY...THE GRADIENT SHOULD REMAIN WEAK ENOUGH TO LIMIT OVERALL WIND POTENTIAL THROUGH THE WEEK...KEEPING WINDS UNDER 10 MPH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 210 PM EDT SUN OCT 18 2015 HIGH PRESSURE WILL REMAIN FIRMLY IN CONTROL OF THE WEATHER THROUGH THE UPCOMING TAF PERIOD. THIS WILL KEEP ALL TAF SITES VFR INTO MONDAY AFTERNOON. THIS HIGH PRESSURE WILL ALSO KEEP WINDS LIGHT THROUGH THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
649 PM EDT SUN OCT 18 2015 .SYNOPSIS... LAKE EFFECT SNOW SHOWERS WILL TAPER OFF THIS EVENING...WITH COLD TEMPERATURES REMAINING ACROSS THE REGION THROUGH TONIGHT. HIGH PRESSURE WILL BRING A WARMING TREND MONDAY THROUGH MUCH OF THE WEEK. && .NEAR TERM /THROUGH MONDAY/... THIS EVENINGS UPDATE WAS MADE TO ADJUST SKY COVER AND POPS BASED ON THE LATEST RADAR/SATELLITE OBSERVATIONS AND TRENDS. EXPECT THE SCATTERED RAIN/SNOW SHOWER ACTIVITY TO TAPER OFF AS SUBSIDENCE LOWERS INVERSIONS...CUTTING OFF THE DEEP SATURATION TO MAINTAIN LAKE-EFFECT SHOWER ACTIVITY. ADJUSTED POPS BASED ON THE HRRR WHICH WILL KEEP CHANCE POPS IN NORTH OF I-80 A LITTLE LONGER. WITH THE SURFACE HIGH BUILDING OVERHEAD...EXPECT CLOUDS TO DISSIPATE...ALLOWING FOR GOOD RADIATIONAL COOLING. WHILE WE ENDED THE GROWING SEASON WITH LAST NIGHTS FREEZE...TEMPERATURES WILL ONCE AGAIN FALL BELOW FREEZING ACROSS MOST OF THE REGION. TEMPERATURES WERE TWEAKED FROM LAST NIGHTS VALUES AND BIAS CORRECTED MOS. WARM ADVECTION AND SUNSHINE WILL PROVIDE FOR WARMING TEMPERATURES TOMORROW...ALTHOUGH HIGHS WERE FORECAST 5-10 DEGREES BELOW SEASONAL AVERAGES. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... MUCH OF THE FIRST HALF OF THE WEEK WILL BE DOMINATED BY GENERALLY ZONAL FLOW ALOFT...A PROGRESSIVE FLOW PATTERN THAT WILL SUPPORT THE RAPID ERADICATION OF THE SURFACE HIGH PRESSURE RESPONSIBLE FOR THE COLD WEEKEND. A WARM FRONT WILL SHARPEN ACROSS THE GREAT LAKES TUESDAY NIGHT INTO WEDNESDAY...LEAVING THE FORECAST AREA SOLIDLY IN THE WARM SECTOR AND H9 TRAJECTORIES TRANSPORTING MODIFIED GULF AIR INTO THE REGION. THROUGH WEDNESDAY NIGHT...IT APPEARS THE ACTIVE JET WILL REMAIN IN SOUTHERN CANADA...SO ANY PRECIPITATION CHANCES APPEAR QUITE LIMITED OWING TO MEAGER MOISTURE AND PROGRESSIVE...LOW-AMPLITUDE WAVES IN THE FLOW. THESE CHANCES ARE HIGHEST ALONG THE SHARPENING WARM FRONT...WHICH SHOULD REMAIN NORTH OF THE FORECAST AREA. POPS WERE TRENDED DOWNWARD MODESTLY IN THE EARLIER PERIODS AND FOCUSED PRIMARILY ACROSS THE FAR-NORTHERN ZONES... WITH INCREASING CHANCES WEDNESDAY NIGHT AREA-WIDE AS A SHORTWAVE TROUGH AXIS IMPINGES ON THE REGION. TEMPERATURES WILL INCREASE AGGRESSIVELY THROUGH THE WEEK AS H9 WARM ADVECTION ENSUES ON A 30-40KT LOW-LEVEL JET. MAXIMA COULD APPROACH 70 IN SOME SPOTS BY MID-WEEK AHEAD OF A COLD FRONTAL PASSAGE LATE IN THE WEEK. MINIMA ALSO WILL BE ABOVE NORMAL IN THE MID-UPPER 40S AS CLOUD COVER AND MOISTURE ADVECTION RETARD OVERNIGHT RADIATIONAL COOLING. KRAMAR && .LONG TERM /THURSDAY THROUGH SUNDAY/... DIGGING LOW PRESSURE IN THE LEE OF THE CANADIAN ROCKIES QUICKLY MOVES INTO THE WESTERN GREAT LAKES BY LATE WEDNESDAY. A TRAILING COLD FRONT WILL CROSS THE FORECAST AREA THURSDAY...BUT LIMITED MOISTURE AND PROGRESSIVE NATURE OF THE SYSTEM ARE EXPECTED TO KEEP PRECIPITATION LIMITED. KEPT POPS IN LOW CHANCE RANGE. THE LASTING IMPACT OF THIS SYSTEM WILL MANIFEST AS AN AMPLIFICATION OF THE LARGE SCALE UPPER-LEVEL FLOW. AS THE LOW CONTINUES TO DIG OVER THE NORTHEASTERN CONUS...AN EXPANSIVE RIDGE WILL SET UP OVER THE MISSISSIPPI VALLEY BY FRIDAY. THIS UPPER HIGH WILL QUELL ANY POTENTIAL PRECIPITATION THROUGH THE EARLY PART OF THE WEEKEND...AND AS THE AXIS SLOWLY SHIFTS EAST...TEMPERATURES WILL CONTINUE TO INCREASE. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... CLOUD COVERAGE WILL GRADUALLY CLEAR OUT OVERNIGHT WITH NORTHWESTERLY WINDS BECOMING LIGHT AS HIGH PRESSURE BECOMES THE DOMINANT FEATURE ACROSS THE REGION. NO FLIGHT RESTRICTIONS ARE ANTICIPATED THROUGH THE TAF PERIOD. OUTLOOK...MONDAY THROUGH THURSDAY. GENERAL VFR UNDER HIGH PRESSURE. && .CLIMATE... A WIDESPREAD FREEZE OCCURRED OVERNIGHT IN ALL ZONES...RESULTING IN A CANCELLATION OF THE FROST/FREEZE PROGRAM FOR THE AUTUMN SEASON. REFER TO PNSPBZ FOR DETAILS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
349 PM EDT SUN OCT 18 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 523 AM EDT SUN OCT 18 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A FAIRLY DEEP TROF OVER ERN N AMERICA AND A RIDGE TO THE W WITH AXIS OVER THE HIGH PLAINS. BTWN THESE FEATURES...NW FLOW CONTINUES OVER THE UPPER GREAT LAKES EARLY THIS MORNING...BUT HEIGHTS ARE RISING AS THE RIDGE AND TROF ARE SHIFTING E. LES CONTINUES INTO THE ERN FCST AREA...E OF MARQUETTE. LES WAS MDT TO HVY AT TIMES IN ALGER AND NRN SCHOOLCRAFT COUNTIES FOR SEVERAL HRS DURING THE NIGHT...BUT LES IS NOW SHOWING A NOTABLE DIMINISHING TREND UNDER FALLING SUBSIDENCE INVERSION. WITH THE START OF WAA...LAKE EFFECT CLOUDS OFF WRN LAKE SUPERIOR ARE DECREASING. SFC HIGH PRES RIDGE AXIS NOW JUST W OF LAKE SUPERIOR IS FCST TO SHIFT QUICKLY E ACROSS THE FCST AREA TODAY. ALONG WITH THE FALLING SUBSIDENCE INVERSION...LES INTO THE ERN FCST WILL END THIS MORNING. ONLY MINOR ADDITIONAL SNOW ACCUMULATIONS UNDER AN INCH WILL OCCUR EARLY THIS MORNING. IF THERE ARE ANY LINGERING CLOUDS OVER THE W AFTER SUNRISE...THEY WILL QUICKLY CLEAR OUT THIS MORNING. SKIES WILL ALSO BECOME MOSTLY SUNNY E THIS AFTN. HIGHS TODAY WILL TOP OUT IN THE 40S E TO AS HIGH AS THE LOWER 50S W WHERE WAA AND MORE SUN WILL AID WARMING. PRES GRADIENT WILL QUICKLY TIGHTEN AFTER PASSAGE OF THE HIGH PRES RIDGE AXIS AS A RAPIDLY DEEPENING SFC LOW TRACKING E TO HUDSON BAY PUSHES AN ASSOCIATED TROF INTO THE WRN PLAINS. EXPECT S WINDS TO ALREADY BEGIN TO SHOW SOME GUSTINESS DURING THE LATTER PORTION OF THE AFTN OVER THE W HALF. WINDS WILL THEN BE THE MAIN STORY TONIGHT. A DEEP SFC LOW OVER HUDSON BAY...DROPPING TO A PRES OF AROUND 28.7 INCHES...WILL DRIVE ASSOCIATED SFC TROF INTO MN. A 50+KT LOW-LEVEL JET WILL SHIFT INTO UPPER MI DURING THE NIGHT. WHILE WAA AND NOCTURNAL COOLING WILL RESULT IN CONSIDERABLE STABILITY PREVENTING ACCESS TO THE PEAK LOW- LEVEL WINDS...MAX PRES FALLS OF AROUND 6MB/3HR SHIFTING ACROSS NRN ONTARIO WILL AID AN INCREASE IN SFC WINDS/GUSTINESS...MAINLY IN THE HIGH TERRAIN AND ESPECIALLY IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR AND ALONG NRN LAKE MI E OF ESCANABA. COULD BECOME FAIRLY WINDY AT LEAST FOR A FEW HRS DURING THE TIME THAT THE ISALLOBARIC WIND COMPONENT IS MAXIMIZED. WINDS WILL KEEP MIN TEMPS UP IN THE 30S TO LWR 40S TONIGHT. INTERIOR SHELTERED LOCATIONS IN THE CNTRL AND E MAY FALL TO THE LWR 30S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 349 PM EDT SUN OCT 18 2015 HI PRES BLDG THRU ONTARIO WL BRING A PERIOD OF DRY...SEASONABLE WX ON TUE BEFORE A PAIR OF DISTURBANCES BRING THE CHC FOR SOME RAIN LATE TUE NIGHT INTO WED NGT. THERE WL BE GENERALLY DRY WX ON THU INTO FRI BEFORE AN APPROACHING COLD FRONT CAUSES MORE SHOWERS NEXT FRI/SAT. THE SW FLOW AHEAD OF THIS FRONT WILL BRING THE WARMEST WX RELATIVE TO NORMAL IN THE EXTENDED PERIOD ON FRI. MON NGT/TUE...SFC COLD FNT ASSOCIATED WITH VIGOROUS SHRTWV/DEEP SFC LO PRES CROSSING HUDSON BAY IS FCST TO PASS THRU UPR MI ON MON EVNG AHEAD OF SFC HI PRES IN CENTRAL CANADA BLDG TOWARD NW ONTARIO. SINCE THE FLOW ALF OVER THE FNT IS FCST TO BE WNW...DRYING ALF WL PRECEDE THE SFC FROPA...SO ANY LINGERING CLDS OVER THE SE CWA WL EXIT EARLY IN THE EVNG AND GIVE WAY TO A PERIOD OF MOCLR CONDITIONS. BUT AS THE SFC HI PRES MOVES INTO FAR NW ONTARIO LATE MON NGT AND THEN E THRU TUE TO THE N OF STALLED FNT IN THE LOWER LKS...A SHALLOW BUT INCRSG NNE VEERING E FLOW ON ITS SRN FLANK AND OFF LK SUP IS LIKELY TO GENERATE SOME LO CLDS AT LEAST IN THE UPSLOPE HIER TERRAIN AREAS NEAR LK SUP BLO SHARP SUBSIDENCE INVRN NEAR 3K FT SHOWN ON FCST SDNGS. THERE WL ALSO BE SOME HI CLDS AROUND ON TUE TO THE NE OF A DVLPG LO PRES IN THE NCENTRAL PLAINS. WITH THE INFUSION OF SHALLOW CNDN AIR... TUE WL BE COOLER THAN MON...ESPECIALLY OVER THE NCENTRAL IF THERE IS EXTENSIVE SC. TEMPS ARE LIKELY TO HOLD IN THE 40S OVER MUCH OF THIS AREA. TUE NGT THRU WED NGT...THERE REMAINS SOME UNCERTAINTY ON THE INTERACTION BTWN A SHRTWV MOVING E THRU THE ZONAL NRN BRANCH FLOW NEAR THE CNDN BORDER AND ANOTHER WEAKER DISTURBANCE PASSING THRU THE WEAKER SRN BRANCH FLOW OVER THE CONUS THAT WL BE RESPONSIBLE FOR THE SFC LO TAKING SHAPE IN THE NCENTRAL PLAINS. ALTHOUGH ALL THE MODELS INDICATE THE NRN BRANCH DISTURBANCE WL BE STRONGER...THE SRN BRANCH SHRTWV/SFC LO WL BE IN CLOSER PROXIMITY TO SOME HIER PWAT/THE STNRY FNT TO THE S AND THUS MAY HAVE A SGNFT IMPACT ON POPS. THE MODELS IN GENERAL SHOW TWO AREAS OF HIER QPF FOLLOWING THE GREATER DYNAMIC SUPPORT ASSOCIATED WITH THESE OUT-OF-PHASE DISTURBANCES. MOST OF THE SCENARIOS SHOW UPR MI REMAINING BTWN THE TWO QPF MAXIMUMS BEFORE MORE PHASING AND THE SEPARATE PCPN AREAS TEND TO MERGE TO THE E OF THE CWA LATER ON WED. AT THIS POINT...WL FOLLOW MODEL CONSENSUS THAT FEATURES CHC POPS AHEAD OF THE SRN SHRTWV/SLOWLY RETURNING WARM FNT ARRIVING FM THE SW ON TUE NGT AND THEN DIMINISHING ON WED NGT FOLLOWING THE PASSAGE OF THE SHRTWVS TO THE E AND APRCH OF TRAILING HI PRES FM THE W. RIGHT NOW...MOST OF THE MODELS INDICATE THE INCRSG NW FLOW BEHIND THE STRENGTHENING/DEPARTING WL NOT DRAG ENUF COLD AIR /FCST H85 TEMPS ARND -2C/ INTO THE UPR LKS TO GENERATE ANY SGNFT LK EFFECT PCPN ON WED NGT. THE 18/00Z EMCWF IS AN EXCEPTION...WITH A SHARPER CYC NNW FLOW AND H85 TEMPS FALLING CLOSER TO -5C BY 12Z THU. SUSPECT THERE WL BE ENUF COOLING TO RESULT IN AT LEAST SOME LO CLDS OVER MAINLY THE NRN TIER ON WED NGT INTO EARLY THU IN THE LLVL NNW FLOW BEHIND THE DEPARTING LO. EXTENDED...ANY LK CLDS OVER THE NRN TIER ON THU MRNG WL GIVE WAY TO MORE SUNSHINE IN THE AFTN WITH THE ARRIVAL OF AN UPR RDG/SFC HI PRES TRAILING THE DEPARTING LO PRES. DRY...QUIET AND SEASONABLY CHILLY CONDITIONS WL THEN PREVAIL THU NGT AS THE RDG PASSES OVHD. ALTHOUGH FRI WL START OFF DRY...MORE CLDS AND PERHAPS SOME SHOWERS WL MOVE INTO AT LEAST THE W HALF DURING THE AFTN. MOST OF THE LONGER RANGE GUIDANCE INDICATES A COLD FNT/BAND OF SHOWERS ASSOCIATED WITH A SHRTWV RIDING NE OUT OF THE WRN TROF WL CROSS UPR MI SOMETIME BTWN FRI NGT AND SAT NGT AHEAD OF TRAILING HI PRES APRCHG LATER IN THE WEEKEND. ABOVE NORMAL TEMPS ON FRI INTO SAT WL GIVE WAY TO MORE SEASONABLE WX ON SUN FOLLOWING THE FROPA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 100 PM EDT SUN OCT 18 2015 HIGH PRESSURE CENTERED OVER S IL/SIN/KY IS EXTENDING A RIDGE OVER EUPPER MI IS KEEPING DRY WEATHER GOING OVER THE 3 TAF SITES TODAY.HOWEVER...THERE IS A CHANGE IN THE FORM OF AN INCREASED PRESSUREGRADIENT THIS AFTERNOON AS RAPIDLY DEEPENING LOW PRESSURE ALONG THEN MANITOBA BORDER SHIFTS ACROSS HUDSON BAY TONIGHT THROUGH MONDAY.WHILE VFR CONDITIONS REMAIN...WINDS WILL BE THE MAIN ISSUE THISPERIOD. LLWS IS EXPECTED TONIGHT AT CMX AND SAW AS A STRONG LLJDEVELOPS OVER THE NOCTURNAL INVERSION. DID NOT INCLUDE LLWS ATIWD...DUE TO THE WINDS REMAINING MORE GUSTY AND MIXED OVERNIGHT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 349 PM EDT SUN OCT 18 2015 TIGHTENING PRES GRADIENT BEHIND HI PRES SHIFTING INTO THE NE CONUS AND DEEP LO PRES OVER HUDSON BAY/ATTENDANT COLD FRONT EXTENDING INTO THE UPPER MS RIVER VALLEY WILL CAUSE SW GALES TONIGHT INTO MON MORNING...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW AND OVER THE EASTERN PART OF THE LAKE WHERE THIS TYPE OF PATTERN TYPICALLY PRODUCES THE STRONGEST WINDS. THE HIGHEST OBS PLATFORMS WILL PROBABLY SEE WIND GUSTS IN EXCESS OF 40KT FOR A TIME. MAINTAINED GOING GALE WARNINGS ISSUED EARLIER FOR THESE AREAS. WINDS WILL DIMINISH TO UNDER 25KT W TO E ON MON. AFTER A COLD FRONT PASSES LATE MON AFTERNOON AND EVENING...N TO NE WINDS WILL INCREASE TO 20-30KT OVER MUCH OF THE LAKE AHEAD OF HIGH PRES THAT WILL BUILD SE INTO NORTHERN ONTARIO ON TUE. PLAN ON THE STRONGEST WINDS OVER WESTERN LAKE SUPERIOR WHERE THE TERRAIN WILL FUNNEL AND ENHANCE THIS FLOW. WINDS WILL THEN VEER TO THE E-SE TUE NIGHT/WED AS THE HI MOVES INTO QUEBEC AND A LO PRES TROF APPROACHES. THE STRONGER SE WINDS UP TO 30 KTS ARE MOST LIKELY OVER THE E HALF OF THE LAKE ON WED. AFTER THE TROF PASSES BY LATE WED...WINDS WILL SHIFT TO THE NW AND DIMINISH BY LATE THU AS TRAILING HI PRES BUILDS INTO THE WESTERN GREAT LAKES. S WINDS WILL INCREASE UP TO 25 KTS ON FRI FOLLOWING THE PASSAGE OF THIS HI TO THE E AND UNDER A SHARPENING PRES GRADIENT AHEAD OF AN APPROACHING COLD FRONT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 11 AM EDT MONDAY FOR LSZ266-267. GALE WARNING FROM 11 PM THIS EVENING TO 8 AM EDT MONDAY FOR LSZ263-264. LAKE MICHIGAN... GALE WARNING FROM 1 AM TO 2 PM EDT MONDAY FOR LMZ221-248-250. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...KF MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
100 PM EDT SUN OCT 18 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 523 AM EDT SUN OCT 18 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A FAIRLY DEEP TROF OVER ERN N AMERICA AND A RIDGE TO THE W WITH AXIS OVER THE HIGH PLAINS. BTWN THESE FEATURES...NW FLOW CONTINUES OVER THE UPPER GREAT LAKES EARLY THIS MORNING...BUT HEIGHTS ARE RISING AS THE RIDGE AND TROF ARE SHIFTING E. LES CONTINUES INTO THE ERN FCST AREA...E OF MARQUETTE. LES WAS MDT TO HVY AT TIMES IN ALGER AND NRN SCHOOLCRAFT COUNTIES FOR SEVERAL HRS DURING THE NIGHT...BUT LES IS NOW SHOWING A NOTABLE DIMINISHING TREND UNDER FALLING SUBSIDENCE INVERSION. WITH THE START OF WAA...LAKE EFFECT CLOUDS OFF WRN LAKE SUPERIOR ARE DECREASING. SFC HIGH PRES RIDGE AXIS NOW JUST W OF LAKE SUPERIOR IS FCST TO SHIFT QUICKLY E ACROSS THE FCST AREA TODAY. ALONG WITH THE FALLING SUBSIDENCE INVERSION...LES INTO THE ERN FCST WILL END THIS MORNING. ONLY MINOR ADDITIONAL SNOW ACCUMULATIONS UNDER AN INCH WILL OCCUR EARLY THIS MORNING. IF THERE ARE ANY LINGERING CLOUDS OVER THE W AFTER SUNRISE...THEY WILL QUICKLY CLEAR OUT THIS MORNING. SKIES WILL ALSO BECOME MOSTLY SUNNY E THIS AFTN. HIGHS TODAY WILL TOP OUT IN THE 40S E TO AS HIGH AS THE LOWER 50S W WHERE WAA AND MORE SUN WILL AID WARMING. PRES GRADIENT WILL QUICKLY TIGHTEN AFTER PASSAGE OF THE HIGH PRES RIDGE AXIS AS A RAPIDLY DEEPENING SFC LOW TRACKING E TO HUDSON BAY PUSHES AN ASSOCIATED TROF INTO THE WRN PLAINS. EXPECT S WINDS TO ALREADY BEGIN TO SHOW SOME GUSTINESS DURING THE LATTER PORTION OF THE AFTN OVER THE W HALF. WINDS WILL THEN BE THE MAIN STORY TONIGHT. A DEEP SFC LOW OVER HUDSON BAY...DROPPING TO A PRES OF AROUND 28.7 INCHES...WILL DRIVE ASSOCIATED SFC TROF INTO MN. A 50+KT LOW-LEVEL JET WILL SHIFT INTO UPPER MI DURING THE NIGHT. WHILE WAA AND NOCTURNAL COOLING WILL RESULT IN CONSIDERABLE STABILITY PREVENTING ACCESS TO THE PEAK LOW- LEVEL WINDS...MAX PRES FALLS OF AROUND 6MB/3HR SHIFTING ACROSS NRN ONTARIO WILL AID AN INCREASE IN SFC WINDS/GUSTINESS...MAINLY IN THE HIGH TERRAIN AND ESPECIALLY IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR AND ALONG NRN LAKE MI E OF ESCANABA. COULD BECOME FAIRLY WINDY AT LEAST FOR A FEW HRS DURING THE TIME THAT THE ISALLOBARIC WIND COMPONENT IS MAXIMIZED. WINDS WILL KEEP MIN TEMPS UP IN THE 30S TO LWR 40S TONIGHT. INTERIOR SHELTERED LOCATIONS IN THE CNTRL AND E MAY FALL TO THE LWR 30S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 443 AM EDT SUN OCT 18 2015 TEMPERATURES THROUGH THE EXTENDED WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH A COUPLE CHANCES FOR RAINFALL. MONDAY THROUGH TUESDAY...THE BROAD SURFACE RIDGE OVER THE MID ATLANTIC STATES MONDAY WILL CONTINUE TO SLIDE TO THE SOUTHEAST. AS THIS HAPPENS...A FAIRLY STRONG LOW PRESSURE SYSTEM OVER HUDSON BAY WILL SLIDE INTO NORTHWEST QUEBEC. THERE WILL BE A FAIRLY STRONG PRESSURE GRADIENT BETWEEN THE TWO SYSTEMS ALONG WITH A 40 TO 50 KNOT LLJ...MAINLY OVER EASTERN LAKE SUPERIOR AND NORTHERN LAKE MICHIGAN MONDAY MORNING BEFORE THE GRADIENT SLOWLY RELAXES DURING THE AFTERNOON HOURS. THIS ALONG WITH DECENT MIXING IN THE LOWER LEVEL WILL ALLOW FOR GUSTY SOUTHWEST WINDS...INCLUDING GALES ON LAKE SUPERIOR AND LAKE MICHIGAN. ADDITIONALLY...THE LOW PRESSURE SYSTEM HAS A WEAK TRAILING COLD FRONT STRETCHING FROM HUDSON BAY TO NEAR THE ARROWHEAD OF MINNESOTA MONDAY MORNING. THIS FRONT WILL BECOME MORE ENE TO WSW ORIENTED ACROSS THE AREA BEFORE QUICKLY SLIDING TO THE SOUTH AND EAST OF THE AREA MONDAY NIGHT. THERE MAY BE A FEW RAIN SHOWERS ALONG THE COLD FRONT BUT MOISTURE LOOKS TO BE FAIRLY LIMITED AT THIS POINT AND FORCING LOOKS TO BE FAIRLY WEAK. HAVE ONLY KEPT ISOLATED RAIN SHOWERS IN THE FORECAST FOR MONDAY. BEHIND THE COLD FRONT...A SURFACE RIDGE...ZONAL TO SLIGHT UPPER LEVEL 500MB RIDGING AND DRY AIR WILL BUILD INTO THE AREA LATE MONDAY NIGHT AND LINGER THROUGH MUCH OF THE DAY TUESDAY BRINGING WARMER TEMPERATURES AND AN END TO ANY ISOLATED SHOWERS THAT MAY DEVELOP MONDAY. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AS THE AFOREMENTIONED HIGH PRESSURE SYSTEM SLIDES TO THE EAST OF THE AREA...A FAIRLY STRONG SHORTWAVE AND SURFACE LOW DEVELOPING OVER SOUTHERN CANADA...WILL BEGIN TO SLIDE EASTWARD TOWARD THE AREA TUESDAY NIGHT. IT LOOKS LIKE THERE WILL BE ANOTHER...WEAKER...SHORTWAVE THAT SLIDES IN AHEAD OF THE MAIN SHORTWAVE WHICH COULD HELP TO KICK UP SCATTERED RAIN SHOWERS TUESDAY NIGHT...HOWEVER...THE BETTER FORCING WILL BE WITH THE MUCH STRONGER SHORTWAVE PROGGED TO SLIDE ACROSS LAKE SUPERIOR AND MUCH OF THE U.P. WEDNESDAY INTO WEDNESDAY NIGHT. THURSDAY THROUGH THE EXTENDED...CONTINUED TO USE A CONSENSUS OF THE MODELS THROUGH THIS TIME PERIOD. THE GENERAL TREND IS FOR A SURFACE RIDGE AND ASSOCIATED UPPER LEVEL RIDGE TO BUILD INTO THE AREA THURSDAY AND LINGER THROUGH THURSDAY NIGHT. THERE ARE SOME MODEL DISAGREEMENTS BEYOND THAT. FRIDAY THE NEXT LOW PRESSURE SYSTEM...DEVELOPING OVER THE PLAINS IS PROGGED TO PROGRESS SLOWLY TOWARD THE EAST. THE GFS...AS IS TYPICAL FOR THIS TIME OF YEAR...RUSHES THE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT EASTWARD. THIS SOLUTION WOULD BRING PRECIPITATION INTO THE U.P. FRIDAY AND RUSH IT OUT OF THE AREA BY SATURDAY MORNING. THE EC...IS LESS PROGRESSIVE WITH THIS SYSTEM...WHICH KEEP THE HIGH PRESSURE IN PLACE A BIT LONGER...KEEPING CONDITIONS DRY THROUGH FRIDAY AFTERNOON. THE RAIN SHOWERS WITH THE EC SOLUTION WOULD THEN LINGER THROUGH SATURDAY. THE REDUCED CONFIDENCE IN ANY ONE PARTICULAR MODEL HAS LEANED THE FORECAST MORE TOWARD THE CONSENSUS OF THE MODELS WHICH KEEPS CHANCE POPS IN THE FORECAST FRIDAY THROUGH SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 100 PM EDT SUN OCT 18 2015 HIGH PRESSURE CENTERED OVER S IL/SIN/KY IS EXTENDING A RIDGE OVER EUPPER MI IS KEEPING DRY WEATHER GOING OVER THE 3 TAF SITES TODAY.HOWEVER...THERE IS A CHANGE IN THE FORM OF AN INCREASED PRESSUREGRADIENT THIS AFTERNOON AS RAPIDLY DEEPENING LOW PRESSURE ALONG THEN MANITOBA BORDER SHIFTS ACROSS HUDSON BAY TONIGHT THROUGH MONDAY.WHILE VFR CONDITIONS REMAIN...WINDS WILL BE THE MAIN ISSUE THISPERIOD. LLWS IS EXPECTED TONIGHT AT CMX AND SAW AS A STRONG LLJDEVELOPS OVER THE NOCTURNAL INVERSION. DID NOT INCLUDE LLWS ATIWD...DUE TO THE WINDS REMAINING MORE GUSTY AND MIXED OVERNIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 523 AM EDT SUN OCT 18 2015 HIGH PRES RIDGE WILL QUICKLY SHIFT ACROSS LAKE SUPERIOR TODAY... RESULTING IN A BRIEF PERIOD OF LIGHT WINDS. ALREADY IN THE AFTN... TIGHTENING PRES GRADIENT BEHIND THE RIDGE WILL LEAD TO INCREASING S WINDS...GUSTING TO 20-25KT BY LATE AFTN. WINDS INCREASE FURTHER TONIGHT AS A DEEP LOW TRACKS E OVER HUDSON BAY. WITH AN AREA OF MAX PRES FALLS PASSING N OF THE LAKE...S TO SW WINDS WILL LIKELY REACH GALE FORCE...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW...AND OVER THE EASTERN PART OF THE LAKE WHERE THIS TYPE OF PATTERN TYPICALLY PRODUCES THE STRONGEST WINDS. THE HIGHEST OBS PLATFORMS WILL PROBABLY SEE WIND GUSTS IN EXCESS OF 40KT FOR A TIME. WINDS WILL DIMINISH TO UNDER 25KT W TO E ON MON. AFTER A TROF PASSES LATE MON AFTN AND EVENING...N TO NE WINDS WILL INCREASE TO 20-30KT OVER MUCH OF THE LAKE AHEAD OF HIGH PRES THAT WILL BUILD SE INTO NRN ONTARIO TUE. WINDS WILL THEN VEER TO THE E-SE TUE NIGHT/WED AS THE HIGH MOVES INTO QUEBEC AND A LOW PRES TROF APPROACHES. AFTER THE TROF PASSES...WINDS WILL FINALLY DIMINISH LATER THU WHEN HIGH PRES BUILDS INTO THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 11 AM EDT MONDAY FOR LSZ266-267. GALE WARNING FROM 11 PM THIS EVENING TO 8 AM EDT MONDAY FOR LSZ263-264. LAKE MICHIGAN... GALE WARNING FROM 1 AM TO 2 PM EDT MONDAY FOR LMZ221-248-250. && $$ SHORT TERM...ROLFSON LONG TERM...KEC AVIATION...KF MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
100 PM CDT SUN OCT 18 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT SUN OCT 18 2015 BIGGEST CONCERN IN THE SHORT TERM DEALS WITH FIRE WEATHER TODAY...WITH WEST CENTRAL INTO SOUTH CENTRAL MN EXPECTED TO FLIRT WITH RED FLAG WARNING CRITERIA. SFC RIDGE TONIGHT IS CENTERED OVER WI...WITH SE RETURN FLOW QUICKLY BECOMING ESTABLISHED ACROSS MN. THE MAIN THEME FOR TODAY WILL BE STRONG WAA...AS H85 TEMPS WILL BE WARMING ABOUT 10C OVER WHAT WE SAW YESTERDAY. THERE IS GOOD VISUAL EVIDENCE OF SAID WARM ADVECTION IN THE FORM OF A BANK OF 6K-8K FT CLOUDS THAT HAVE FORMED OVER SRN MN THIS MORNING. RAP 750MB RH ALONG WITH THE CLOUD FORECAST FROM THE HRRR EVENTUALLY LATCHED ON TO THIS CLOUD COVER AND FOLLOWED THESE MODEL FEATURES TO PUSH THAT AREA OF CLOUDS EAST ACROSS SRN MN INTO WI THIS MORNING. BY THE AFTERNOON...THESE CLOUDS WILL BE EAST OF THE MPX CWA AND OUR SKIES WILL REMAIN MAINLY CLEAR UNTIL UPPER LEVEL CLOUDS CURRENTLY OVER CO/WY GET HERE TONIGHT. THOUGH H85 TEMPS ARE WARMING 10C...WE WILL NOT BE MIXING THAT DEEP...WITH NAM/RAP SOUNDINGS SHOWING THE BOUNDARY LAYER BUILDING TO ABOUT 900 MB. MIXING TO THIS LEVEL PRODUCED HIGHS SIMILAR TO WHAT WE HAD GOING...WITH UPPER 60S IN WRN MN AND UPPER 50S IN WRN WI. THESE WARM TEMPERATURES COMBINED WITH DEWPS THIS MORNING IN THE 20S WOULD PRODUCE HUMIDITIES UNDER 25 PERCENT...BUT THE GFS/NAM BOTH SUPPORT DEEP ENOUGH MOISTURE ARRIVING WITH THE SE WINDS TO HELP PUSH DEWPS THIS AFTERNOON UP INTO THE LOWER/MIDDLE 30S IN SOUTHERN/WESTERN MN...WHICH IS JUST ENOUGH TO KEEP AFTERNOON HUMIDITIES ABOUT THE 25 PERCENT THRESHOLD FOR A RFW. STILL...WITH HUMIDITIES LIKELY DROPPING UNDER 30 PERCENT ALONG WITH SE WINDS INCREASING TO BETWEEN 20 AND 25 MPH WITH GUSTS TO AROUND 30 MPH...WILL CONTINUE TO HEADLINE THE INCREASED FIRE WEATHER THREAT IN THE FIRE WEATHER PLANNING FORECAST. TONIGHT...SHORTWAVE ENERGY CURRENTLY OVER CO/WY WILL FLATTEN OUT THE UPPER RIDGE MOVING OVERHEAD TODAY AND BRING A SLUG OF UPPER LEVEL MOISTURE WITH AS WELL. HOWEVER...RH TIME-HEIGHT CROSS SECTIONS SHOW THIS MOISTURE ONLY GETTING DOWN TO ABOUT 15K FT...SO NOT CONCERNED ABOUT ANY PRECIP. HOWEVER...THESE CLOUDS ALONG WITH SOUTHERLY WINDS REMAINING UP OVERNIGHT WILL RESULT IN A VERY MILD NIGHT TONIGHT...WITH MUCH OF THE MN CWA SOUTH OF I-94 STAYING UP IN THE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN OCT 18 2015 THE LONG TERM STILL LOOKS TO START OUT ON A WARM NOTE MONDAY WITH HIGHS AROUND 15 TO 20 DEGREES ABOVE CLIMATOLOGICAL NORMALS. MEANWHILE...PRECIPITATION CHANCES CONTINUE TO WANE UNTIL CLOSER TO THE END OF THE WEEK. THE SURFACE COLD FRONT STILL LOOKS TO BE ON OUR WESTERN DOORSTEP AT DAYBREAK MONDAY. FAVORABLE SOUTHWEST FLOW FOR WARMING WILL ENSUE THROUGH MIDDAY ACROSS MUCH OF CENTRAL AND SOUTH CENTRAL MN. H85 TEMPS IN THE UPPER TEENS /CELSIUS/ SHOULD YIELD UPPER 70S TO NEAR 80 DEGREES OVER SOUTHWEST/SOUTH CENTRAL MN...WITH LOW/MID 70S ACROSS THE REMAINDER OF THE AREA. AT THIS POINT THE PROGGED MOISTURE IS HARDLY SUFFICIENT TO GENERATE MUCH MORE THAN BROKEN MID LEVEL CLOUD COVER ACROSS CENTRAL MN/WI...WITH VIRTUALLY NO FORCING TO MENTION. HAVE THEREFORE REMOVED POPS FOR MONDAY. TUESDAY AN INVERTED TROUGH NOSES INTO THE REGION...ALTHOUGH MODELS ARE STILL ALL OVER THE MAP WITH REGARD TO POSITIONING. TWO AREAS OF PRECIPITATION LOOK TO UNFOLD...WITH MODELS HINTING THE FORECAST AREA COULD LARGELY BE PLACED BETWEEN SAID AREAS. HAVE INCLUDED 20-30 POPS FOR TUESDAY/WEDNESDAY...BUT ACTIVITY LOOKS AS IF IT WOULD BE SCATTERED AT BEST WITH LOW PRECIP AMOUNTS. WEDNESDAY NIGHT AND THURSDAY FLEETING SURFACE HIGH PRESSURE MOVES ACROSS THE AREA...BUT THEN A STRONGER TROUGH WITH A NICE FETCH OF MOISTURE ADVECTION LIFTS INTO THE AREA FOR FRIDAY. HAVE INCLUDED 40-50 POPS FOR FRIDAY AND FRIDAY NIGHT...DRYING OUT FOR SATURDAY. HIGH TEMPERATURES FROM TUESDAY THROUGH THE LONG TERM FORECAST PERIOD LOOK TO RUN AROUND 5 TO 10 DEGREES ABOVE NORMAL...WITH LOWS EVEN WARMER IN THE 10 TO 15 DEGREES ABOVE NORMAL RANGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 100 PM CDT SUN OCT 18 2015 ONLY SIGNIFICANT ISSUE IS WIND SHEAR TONIGHT. SHORT TERM MODELS HAVE STRENGTHENED THE LOW LEVEL WIND EVEN EARLIER...SO MOST LOCALES WILL SEE WIND SHEAR AS EARLY AS 03Z. MAY WELL HAVE OVER 60 KNOTS AT 1500-2500 FT AGL BY 06Z FROM SW MN INTO WESTERN WISC. IN FACT...KRWF MAY SEE 60 KNOTS EVEN AS LOW AS 1200 FT AGL...THOUGH THIS IS NOT CERTAIN. CORE OF STRONGEST WINDS WILL BE FROM SW MN INTO WISC...BUT EVEN WEST CENTRAL MN WILL BE ON THE EDGE OF THIS AND MAY WELL HAVE 50 KNOTS AT 2K TONIGHT. LOW LEVEL WIND SHEAR WILL WEAKEN AS COLD FRONT APPROACHES. OTHERWISE JUST SOME CIRRUS AND MAYBE SOME MID CLOUDS. KMSP...SCATTERED CLOUDS AROUND 7K FT HAVE VIRTUALLY DISSIPATED. ONLY ISSUE WILL BE WIND. MODELS ALL SHOW A STRONG JET DEVELOPING THIS EVENING...WITH 50 KNOTS AT 2K AGL AS EARLY AS 03Z. SOME SHORT TERM MODELS EVEN RAMP UP THE 2K AGL WIND TO 60 KNOTS BY 06Z. THUS HAVE CONTINUED THE MENTION OF LOW LEVEL WIND SHEAR...BUT STARTED IT EARLIER THAN PREVIOUSLY FORECAST. OTHERWISE JUST SOME CIRRUS AND MAYBE MID LEVEL CLOUDS. /OUTLOOK FOR KMSP/ MON...VFR. WINDS SW 15G25KTS TUE...VFR. WINDS NE/E 5-10KTS. WED...VFR. CHC MRNG SHRA. WINDS E BCMG NW 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...LS AVIATION...TDK
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1005 AM PDT SUN OCT 18 2015 .SYNOPSIS...A BROAD LOW PRESSURE SYSTEM MOVING ACROSS CALIFORNIA AND NEVADA WILL BRING WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS TODAY...ALONG WITH A THREAT OF FLASH FLOODING. ADDITIONAL UPPER LEVEL DISTURBANCES WILL CONTINUE TO PROVIDE UNSETTLED AND COOL CONDITIONS INTO THE MIDDLE OF NEXT WEEK. && .UPDATE...THE LATEST SATELLITE AND RADAR TRENDS INDICATE CONVECTION IS DEVELOPING PRETTY CLOSELY TO HOW INHERITED POP/WX GRIDS DEPICT. A TRAIN OF THUNDERSTORMS HAS BEEN PERSISTING FROM DEATH VALLEY JUNCTION UP THROUGH AMARGOSA VALLEY AND THE NEVADA NATIONAL SECURITY SITE. RECENT HRRR RUNS DEPICT A LINE OF CONVECTION DEVELOPING FROM MOUNTAIN PASS IN CALIFORNIA UP THROUGH CENTRAL AND NORTHEAST CLARK COUNTY BETWEEN 19Z AND 23Z. ONLY MINOR ADJUSTMENTS WERE MADE TO THE POP/WX GRIDS TO INCREASE STORM COVERAGE TO SCATTERED DOWN TO BARSTOW AND TWENTYNINE PALMS THIS AFTERNOON. THE REST OF THE TRENDS DETAILED IN THE PREVIOUS DISCUSSION LOOK OKAY. && .AVIATION...FOR MCCARRAN...WINDS LIKELY TO REMAIN LIGHT AND VARIABLE UNDER 8 KTS THE REMAINDER OF THE MORNING...THEN INCREASE TO 12-16KTS WITH GUSTS TO 25 KTS FROM THE SOUTH-SOUTHWEST BY NOON. SHOWER AND THUNDERSTORM ACTIVITY WILL BE FAIRLY LIMITED THE REMAINDER OF THE MORNING...BUT CANNOT BE COMPLETELY RULED OUT. CIGS OF 4-6K NEAR ANY SHOWER ACTIVITY TONIGHT...OTHERWISE SCT-BKN CLOUDS AT 6-8K FEET. CHANCES FOR SHRA/TSRA WILL INCREASE EARLY THIS AFTERNOON AND PEAK BETWEEN 20Z-23Z. CIGS OF 3-5K FEET ARE EXPECTED WITH THIS ACTIVITY ALONG WITH MOUNTAIN OBSCURATIONS. STORMS COULD BRING GUSTY WINDS IN EXCESS OF 35 KTS THESE STORMS...AS WELL AS REDUCED VSBY DUE TO HEAVY RAIN. SLIGHT CHANCES FOR SHRA/TSRA WILL CONTINUE THROUGH EARLY NEXT WEEK...MAINLY IN THE MOUNTAINS SURROUNDING THE VALLEY AND IN THE EASTERN CORRIDORS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...A BAND OF SHOWERS AND SCATTERED THUNDERSTORMS DEVELOPED THIS MORNING AND WILL SLOWLY PUSH EAST ACROSS MAINLY SOUTHERN NEVADA TODAY AND INTO NORTHWEST ARIZONA LATE THIS AFTERNOON AND EVENING. THE STRONGEST THUNDERSTORMS WILL BE FAVORED OVER CLARK...NYE...LINCOLN AND MOHAVE COUNTIES THROUGH THIS AFTERNOON. GUSTS EXCEEDING 35 KTS ARE POSSIBLE WITH THUNDERSTORMS. CIGS WILL MAINLY BE 3K-6K FEET IN AND NEAR SHRA/TSRA OTHERWISE 6K-10K FEET. VSBY MAY BE REDUCED TO MVFR OR LOWER AND MOUNTAIN OBSCURATIONS ARE LIKELY IN AND NEAR ANY SHRA/TSRA. OUTSIDE OF TSRA EXPECT SOUTHWEST WINDS TO INCREASE TO 10-20 KTS WITH GUSTS 20-30 KTS IN MOST LOCATIONS BY THE AFTERNOON. CHANCES FOR SHRA/TSRA WILL CONTINUE THROUGH EARLY NEXT WEEK...MAINLY FROM LAS VEGAS EAST. && .PREV DISCUSSION... 251 AM PDT SUN OCT 18 2015 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. TODAY...CONVECTION HAS BEEN INCREASING OVER THE PAST THREE HOURS AS EXPECTED ALONG A LINE FROM BARSTOW TO TONOPAH. THUS FAR...STORMS HAVE BEEN SOMEWHAT ISOLATED AND INTENSE...BUT SHORT RANGE GUIDANCE INDICATED THAT THE LINE SHOULD FILL IN SOMEWHAT THROUGH THE MORNING HOURS. THIS CONVECTION HAS DEVELOPED IN RESPONSE TO THE INTERACTION OF DIFFLUENT UPPER LEVEL FLOW AHEAD OF AN EJECTING SHORTWAVE AND MODERATELY UNSTABLE CONDITIONS WITH ANOMALOUSLY HIGH MOISTURE LEVELS. THIS LINE IS EXPECTED TO PUSH EAST ACROSS THE REGION TODAY. GUIDANCE HAS SPED UP THE EASTWARD PROGRESSION OF THIS LINE...WITH LAS VEGAS LIKELY UNDER THE GUN BETWEEN 15Z-21Z (8AM-2PM). BY MID TO LATE MORNING MORE WIDESPREAD...DIURNALLY AIDED CONVECTION IS EXPECTED TO BREAK OUT AHEAD OF THIS LINE ACROSS MOHAVE...EASTERN SAN BERNARDINO AND EASTERN CLARK COUNTIES. PRECIPITABLE WATER VALUES OF 1.00-1.50" ARE ALREADY IN PLACE ACROSS THE REGION. THIS IS WELL ABOVE RECORD LEVELS FOR THE MONTH (FOR REFERENCE...THE PREVIOUS OCTOBER RECORD WAS 1.07" AND THE 90TH PERCENTILE FOR THE DATE IS 0.65"). STORM MOTION TODAY WILL TO THE NNE AT AROUND 20 MPH...HOWEVER CONDITIONS SHOULD BE FAVORABLE FOR TRAINING STORMS...ESPECIALLY TO THE NORTH-NORTHEAST OF HIGHER TERRAIN FEATURES. ALL OF THIS MEANS THE THE PRIMARY THREAT WITH STORMS TODAY WILL BE FLASH FLOODING AND THE FLASH FLOOD WATCH WILL REMAIN IN EFFECT THROUGH THIS EVENING. HAIL AND GUSTY WINDS WILL ALSO BE POSSIBLE TODAY COURTESY OF 0-6KM SHEAR VALUES OF 25-40KTS...WHICH MAY ALSO AID IN STORM ORGANIZATION. MUCH OF THIS ACTIVITY IS EXPECTED TO PUSH EAST OF THE AREA OVERNIGHT...THOUGH LINGERING CHANCES WILL REMAIN ACROSS AT LEAST LINCOLN AND MOHAVE COUNTIES. MONDAY...ANOTHER SHORTWAVE IS EXPECTED TO HELP DIG TODAYS UPPER LEVEL LOW FURTHER SOUTH...LEAVING AT LEAST THE EASTERN HALF OF THE FORECAST AREA (FROM LAS VEGAS EAST) WITH CHANCES FOR ADDITIONAL STORMS. TUESDAY AND WEDNESDAY...MONDAY`S SHORTWAVE SHOULD ALLOW THE UPPER LEVEL LOW TO WRAP UP AND BECOME CENTERED NEAR YUMA. THIS IS LIKELY TO RESULT IN INCREASED NORTHERLY FLOW ACROSS THE REGION...AND GUSTY NORTH WINDS ARE LIKELY IN FAVORED AREAS SUCH AS THE COLORADO RIVER VALLEY. DESPITE THIS...MOISTURE WILL CONTINUE TO LINGER ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA AND CHANCE FOR STORMS WILL CONTINUE...WITH THE BEST CHANCES OVER THE HIGHER TERRAIN OF CLARK...MOHAVE...LINCOLN AND EASTERN SAN BERNARDINO COUNTIES. .LONG TERM...THURSDAY THROUGH SATURDAY. PATTERN SHOULD BECOME FAVORABLE FOR DRIER NORTHWEST FLOW...WHICH SHOULD HELP BRING RELIEF FROM A PROLONGED PERIOD OF UNSETTLED AND WET WEATHER. SHORTWAVES MOVING THROUGH THE FLOW COULD BRING ENHANCED WINDS TO THE REGION AT TIMES. OTHERWISE EXPECT CALMER AND SLIGHTLY WARMER CONDITIONS THAN THE FIRST HALF OF THE WEEK. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE REQUIRED TODAY. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ UPDATE...ADAIR AVIATION...GORELOW PREV DISCUSSION...WOLCOTT FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
106 PM CDT SUN OCT 18 2015 .UPDATE... ISSUED AT 103 PM CDT SUN OCT 18 2015 NO SIGNIFICANT CHANGES FOR THE EARLY AFTERNOON UPDATE. A FEW CLOUDS STARTING TO MOVE INTO THE SOUTHWEST...OTHERWISE SUNNY. BREEZY CONDITIONS IN THE JAMES RIVER VALLEY WITH GUSTS TO AROUND 30 MPH. UPDATE ISSUED AT 943 AM CDT SUN OCT 18 2015 LATEST WV LOOP SHOWS UPPER LOW MOVING ONTO THE NORTHERN CALIFORNIA COAST. LEAD SHORTWAVE ENERGY IS LIFTING THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN HIGH PLAINS. UPPER LEVEL RIDGING REMAINS OVER WESTERN AND CENTRAL NORTH DAKOTA...BUT WILL FLATTEN DURING THE DAY DUE TO AFOREMENTIONED SHORTWAVE ENERGY...AND ANOTHER NORTHERN STREAM WAVE. BREEZY EAST TODAY BUT OVERALL QUIET WITH SOME INCREASING MID AND HIGH LEVEL CLOUDS WEST. SUNNY EAST. FOR THE MORNING UPDATE...INCREASED CLOUDS AND MINIMAL POPS WEST FOR TONIGHT. MESOSCALE MODELS AND THE ECMWF BRING INCREASING MID LEVEL MOISTURE INTO WESTERN NORTH DAKOTA...AND LAST FEW ITERATIONS OF THE HRRR HAVE BROUGHT SOME LIGHT QPF THROUGH NORTHEAST MONTANA. WILL KEEP AN EYE ON HOW THINGS TREND THROUGH THE DAY BUT FOR NOW DID NOT BRING ANY MENTION OF PRECIP INTO THE WORDED FORECAST IN THE WEST TONIGHT AS ATMOSPHERE BELOW THIS MID LEVEL MOISTURE REMAIN QUITE DRY. UPDATE ISSUED AT 636 AM CDT SUN OCT 18 2015 FORECAST ON TRACK. HOURLY TEMPS WERE A LITTLE TOO HIGH ACROSS SOME AREAS...THEREFORE BLENDED FORECAST TO CURRENT OBSERVATIONS. OTHERWISE...NO CHANGES MADE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 301 AM CDT SUN OCT 18 2015 SURFACE HIGH PRESSURE WILL CONTINUE TO DRIFT AWAY FROM THE FORECAST AREA TODAY...TO THE SOUTHEAST...WHILE A LEE SIDE TROUGH THROUGH EASTERN MONTANA PUSHES THROUGH WILLISTON AND DICKINSON BY SUNSET. THIS RESULTS IN SOUTHEAST SURFACE WINDS. MID LEVEL SUPPORT WAS VERY WEAK AND WITH A LACK OF LOW LEVEL MOISTURE THE TROUGH PASSAGE IS FORECAST TO BE DRY. HIGH TEMPERATURES TODAY WILL BE 10 DEGREES ABOVE MID OCTOBER NORMALS OVER THE JAMES RIVER VALLEY TO 20 DEGREES ABOVE NORMAL AT HETTINGER. A GUSTY SOUTHEAST WIND AHEAD OF THE TROUGH...WITH HIGHEST WIND SPEEDS THROUGH THE JAMES RIVER VALLEY...WILL REMAIN BELOW WIND ADVISORY CRITERIA. HIGHER HUMIDITY THROUGH THE JAMES VALLEY WILL ACT TO DAMPEN FIRE WEATHER CONCERNS TODAY. THE DRY TROUGH PASSES THROUGH THE REST OF THE FORECAST AREA TONIGHT WITH PARTLY CLOUDY SKIES. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 301 AM CDT SUN OCT 18 2015 00Z GFS/ECMWF/CANADIAN MODELS ARE IN DECENT AGREEMENT EARLY IN THE PERIOD SHOWING A MORE ACTIVE WEEK SETTING UP WITH THE FIRST CHANCE OF PRECIP MONDAY NIGHT THROUGH TUESDAY WITH OUR REGION IN SOUTHWEST FLOW AHEAD OF LONGWAVE TROUGH ACROSS INTERMOUNTAIN WEST EARLY IN THE WEEK. FORECAST CONTINUES WITH MAINLY CHANCE POPS FOR THIS SYSTEM. NEXT SYSTEM APPROACHES THE NORTHERN PLAINS ON THURSDAY WITH MODELS SHOWING MORE SIGNIFICANT DIFFERENCES. OPERATIONAL GFS IS MUCH FASTER WITH THIS SYSTEM AND FARTHER NORTH WITH SURFACE LOW COMPARED TO GFS ENSEMBLES AND ECMWF. GFS HAS PRECIP EAST OF NORTH DAKOTA EARLY FRIDAY WHILE ECMWF/CANADIAN MODELS HOLD PRECIP ACROSS THE STATE FOR MUCH OF THE DAY. FORECAST LEANS MORE TOWARD THE SLOWER SOLUTIONS AND MAINTAINS PRECIP THROUGH FRIDAY. WITH REGARD TO TEMPERATURES...EXPECT THEM TO CONTINUE TO RUN NEAR/ABOVE NORMAL WITH HIGHS MAINLY IN THE 50 AND SOME LOW 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 103 PM CDT SUN OCT 18 2015 VFR CONDITIONS EXPECTED THROUGH THE 18Z FORECAST PERIOD. A DRY AND WEAK COLD FRONT WILL MOVE THROUGH THE FORECAST AREA SHIFTING WINDS FROM SOUTHERLY TODAY TO NORTHERLY MONDAY. MIGHT SEE A FEW SPRINKLES FALLING FROM SOME MID-LEVEL CLOUDS...BUT TO SPARSELY POPULATED TO EVEN MENTION A VCSH AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...JPM LONG TERM...JNS AVIATION...TWH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
700 PM EDT SUN OCT 18 2015 .SYNOPSIS... A DEEP UPPER LEVEL TROUGH OVER EASTERN CANADA WILL LIFT OUT...LEADING TO A MILDER WEATHER PATTERN WITH LIMITED OPPORTUNITIES FOR RAIN FOR MUCH OF THE UPCOMING WEEK...WITH TEMPERATURES RISING NEAR TO ABOVE NORMAL FOR LATE OCTOBER. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... STILL A FEW RAIN AND SNOW SHOWERS ON RADAR...BUT THESE SHOULD BE GONE SOON...AS THE SUN SETS. CURRENT FCST PACKAGE IN GOOD SHAPE. EARLIER DISCUSSION BELOW. RADAR IS FILLED WITH FAST MOVING SCATTERED SHOWERS. LOCALLY WE ARE VARYING BETWEEN THE UPPER 30S AND LOWER 40S DEPENDING ON WHETHER WE HAVE PRECIPITATION IN PROGRESS...WITH IT TENDING TOWARD WET SNOW WHEN IT IS ACTUALLY DOING SOMETHING. THE HRRR INDICATES THESE SHOWERS WILL MAX OUT HERE IN THE NEXT HOUR OR TWO BEFORE DWINDLING AS THE UPPER FORCING ASSOCIATED WITH THE LEFT JET EXIT REGION SWINGS OFF TO OUR EAST. THE GREATEST RISK FOR SNOW TO ACTUALLY WHITEN THE GROUND...ESPECIALLY ON GRASSY SURFACES...WILL BE DOWNWIND OF LAKE ERIE OVER THE HIGHER ELEVATIONS OF THE ALLEGHENY FOREST REGION. MORE DOWNWIND OUT OF THE NORTHERN HIGHER ELEVATIONS...WET SNOW OR A MIX OF RAIN AND SNOW WILL MEAN MOST AREAS WILL NOT EXPERIENCE ANY SNOW ACCUMS. HIGH PRESSURE WILL MIGRATE EWD FROM THE LWR OH VALLEY LATER TODAY AND BE CENTERED OVER THE MD/WV PANHANDLE BY 12Z MONDAY. THE INCREASING LARGE SCALE SUBSIDENCE AND BACKING LOW LEVEL TRAJECTORIES WILL SPELL AN END TO THE LAKE EFFECT SHOWER ACTIVITY. MORE IMPORTANTLY THERE SHOULD ALSO BE A DECREASE IN CLOUD COVER...SETTING THE STAGE FOR A WIDESPREAD KILLING FREEZE. HAVE CONTINUED THE FREEZE WARNING WITH HIGH CONFIDENCE IN ENDING THE GROWING SEASON. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... HIGH PRESSURE WILL SETTLE OFF TO THE SOUTHEAST OF THE REGION MONDAY...ALLOWING A MILDER SOUTHWEST FLOW TO DEVELOP. IT SHOULD LEAD TO A BRIGHT DAY WITH HIGHS REBOUNDING...AVERAGING SOME 5 TO 15 DEGREES WARMER THAN TODAY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... UPPER TROF CURRENTLY OVER THE NERN NORTH AMERICA IS FORECAST TO LIFT/PROGRESS EWD THROUGH EARLY THIS WEEK. UPPER LONGWAVE TROF ALONG THE WEST COAST IS FORECAST TO DROP SOUTH AND CLOSE OFF OVER THE DESERT SW. THIS WILL ALLOW HEIGHT TO RISE SLOWLY OVER THE EASTERN HALF OF THE COUNTRY THROUGH THE WEEK...BUT AN ACTIVE NRN STREAM PATTERN SHOULD KEEP THE UPPER RIDGE OVER THE CENTRAL AND SERN U.S. FROM EXPANDING TOO FAR NORTH. A MILDER SPLIT-FLOW WEATHER PATTERN IS EXPECTED TO DEVELOP AND PERSIST THROUGH MUCH OF NEXT WEEK. THE GLOBAL MODELS AND ENSEMBLE PREDICTION SYSTEMS INDICATE THAT PCPN OPPORTUNITIES WILL REMAIN VERY LIMITED ACROSS THE AREA. THAT SAID THERE IS SOME SPREAD IN KEY SYNOPTIC FEATURES OVER THE LOWER 48...NAMELY THE NRN STREAM SHORTWAVE EVOLUTION CROSSING SERN CANADA/GRT LKS REGION AROUND THURSDAY. THE 18/00Z ECMWF IS DEEPER/SLOWER WITH THE H5 SYSTEM AND FAVORS A MORE PRONOUNCED MID LEVEL TROUGH IN THE NORTHEAST THURS NGT-FRI. THE GFS/GEFS AND GEM ARE MORE PROGRESSIVE WITH THE NRN STREAM WAVE WHICH ALLOWS UPPER RIDGING TO BULGE NWD FROM THE GOMEX. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... UPPER LVL TROUGH AND ASSOC COLD AIR ALOFT IS PRODUCING SCT SHSNRA ACROSS CENTRAL PA AS OF 21Z. ALTHOUGH WIDESPREAD VFR CONDS NOTED AT 21Z...A BRIEF REDUCTION FROM PASSING SHOWERS REMAINS POSSIBLE THRU ARND 23Z. HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT...BRINGING AN END TO THE THREAT OF SHSNRA BY 00Z. FOCUS WILL THEN SHIFT TOWARD THE POSSIBILITY OF LATE NIGHT VALLEY FOG...AS SKIES CLEAR AND THE WIND DIMINISHES. WOULD BE WARY OF WHAT APPEARS TO BE OVERLY OPTIMISTIC MOS GUIDANCE...WHICH INDICATES NO FOG. OVERNIGHT CLEAR SKIES/CALM WIND THIS TIME OF YEAR USUALLY YIELDS AT LEAST PATCHY FOG...AS THE LATEST SREF AND DOWNSCALED NAM SUGGEST. WILL AWAIT LATER MODEL GUIDANCE FOR POSSIBLE INCLUSION OF LATE NIGHT FOG IN THE FCST UPDATE AT 00Z. ANY POSSIBLE VALLEY FOG SHOULD BURN OFF SHORTLY AFTER 12Z MONDAY. HIGH PRESSURE OVR THE REGION SHOULD ENSURE A NEAR CERTAINTY OF VFR CONDS FOR THE REST OF THE DAY. OUTLOOK... TUE-WED...MAINLY VFR. NO SIG WX EXPECTED. THU...MAINLY VFR...BUT A FEW SHOWERS POSSIBLE...MAINLY N PA. FRI...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE/MARTIN SHORT TERM...LA CORTE LONG TERM...GARTNER/STEINBUGL AVIATION...FITZGERALD/LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
510 PM EDT SUN OCT 18 2015 .SYNOPSIS... A DEEP UPPER LEVEL TROUGH OVER EASTERN CANADA WILL LIFT OUT...LEADING TO A MILDER WEATHER PATTERN WITH LIMITED OPPORTUNITIES FOR RAIN FOR MUCH OF THE UPCOMING WEEK...WITH TEMPERATURES RISING NEAR TO ABOVE NORMAL FOR LATE OCTOBER. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... RADAR IS FILLED WITH FAST MOVING SCATTERED SHOWERS. LOCALLY WE ARE VARYING BETWEEN THE UPPER 30S AND LOWER 40S DEPENDING ON WHETHER WE HAVE PRECIPITATION IN PROGRESS...WITH IT TENDING TOWARD WET SNOW WHEN IT IS ACTUALLY DOING SOMETHING. THE HRRR INDICATES THESE SHOWERS WILL MAX OUT HERE IN THE NEXT HOUR OR TWO BEFORE DWINDLING AS THE UPPER FORCING ASSOCIATED WITH THE LEFT JET EXIT REGION SWINGS OFF TO OUR EAST. THE GREATEST RISK FOR SNOW TO ACTUALLY WHITEN THE GROUND...ESPECIALLY ON GRASSY SURFACES...WILL BE DOWNWIND OF LAKE ERIE OVER THE HIGHER ELEVATIONS OF THE ALLEGHENY FOREST REGION. MORE DOWNWIND OUT OF THE NORTHERN HIGHER ELEVATIONS...WET SNOW OR A MIX OF RAIN AND SNOW WILL MEAN MOST AREAS WILL NOT EXPERIENCE ANY SNOW ACCUMS. HIGH PRESSURE WILL MIGRATE EWD FROM THE LWR OH VALLEY LATER TODAY AND BE CENTERED OVER THE MD/WV PANHANDLE BY 12Z MONDAY. THE INCREASING LARGE SCALE SUBSIDENCE AND BACKING LOW LEVEL TRAJECTORIES WILL SPELL AN END TO THE LAKE EFFECT SHOWER ACTIVITY. MORE IMPORTANTLY THERE SHOULD ALSO BE A DECREASE IN CLOUD COVER...SETTING THE STAGE FOR A WIDESPREAD KILLING FREEZE. HAVE CONTINUED THE FREEZE WARNING WITH HIGH CONFIDENCE IN ENDING THE GROWING SEASON. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... HIGH PRESSURE WILL SETTLE OFF TO THE SOUTHEAST OF THE REGION MONDAY...ALLOWING A MILDER SOUTHWEST FLOW TO DEVELOP. IT SHOULD LEAD TO A BRIGHT DAY WITH HIGHS REBOUNDING...AVERAGING SOME 5 TO 15 DEGREES WARMER THAN TODAY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... UPPER TROF CURRENTLY OVER THE NERN NORTH AMERICA IS FORECAST TO LIFT/PROGRESS EWD THROUGH EARLY THIS WEEK. UPPER LONGWAVE TROF ALONG THE WEST COAST IS FORECAST TO DROP SOUTH AND CLOSE OFF OVER THE DESERT SW. THIS WILL ALLOW HEIGHT TO RISE SLOWLY OVER THE EASTERN HALF OF THE COUNTRY THROUGH THE WEEK...BUT AN ACTIVE NRN STREAM PATTERN SHOULD KEEP THE UPPER RIDGE OVER THE CENTRAL AND SERN U.S. FROM EXPANDING TOO FAR NORTH. A MILDER SPLIT-FLOW WEATHER PATTERN IS EXPECTED TO DEVELOP AND PERSIST THROUGH MUCH OF NEXT WEEK. THE GLOBAL MODELS AND ENSEMBLE PREDICTION SYSTEMS INDICATE THAT PCPN OPPORTUNITIES WILL REMAIN VERY LIMITED ACROSS THE AREA. THAT SAID THERE IS SOME SPREAD IN KEY SYNOPTIC FEATURES OVER THE LOWER 48...NAMELY THE NRN STREAM SHORTWAVE EVOLUTION CROSSING SERN CANADA/GRT LKS REGION AROUND THURSDAY. THE 18/00Z ECMWF IS DEEPER/SLOWER WITH THE H5 SYSTEM AND FAVORS A MORE PRONOUNCED MID LEVEL TROUGH IN THE NORTHEAST THURS NGT-FRI. THE GFS/GEFS AND GEM ARE MORE PROGRESSIVE WITH THE NRN STREAM WAVE WHICH ALLOWS UPPER RIDGING TO BULGE NWD FROM THE GOMEX. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... UPPER LVL TROUGH AND ASSOC COLD AIR ALOFT IS PRODUCING SCT SHSNRA ACROSS CENTRAL PA AS OF 21Z. ALTHOUGH WIDESPREAD VFR CONDS NOTED AT 21Z...A BRIEF REDUCTION FROM PASSING SHOWERS REMAINS POSSIBLE THRU ARND 23Z. HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT...BRINGING AN END TO THE THREAT OF SHSNRA BY 00Z. FOCUS WILL THEN SHIFT TOWARD THE POSSIBILITY OF LATE NIGHT VALLEY FOG...AS SKIES CLEAR AND THE WIND DIMINISHES. WOULD BE WARY OF WHAT APPEARS TO BE OVERLY OPTIMISTIC MOS GUIDANCE...WHICH INDICATES NO FOG. OVERNIGHT CLEAR SKIES/CALM WIND THIS TIME OF YEAR USUALLY YIELDS AT LEAST PATCHY FOG...AS THE LATEST SREF AND DOWNSCALED NAM SUGGEST. WILL AWAIT LATER MODEL GUIDANCE FOR POSSIBLE INCLUSION OF LATE NIGHT FOG IN THE FCST UPDATE AT 00Z. ANY POSSIBLE VALLEY FOG SHOULD BURN OFF SHORTLY AFTER 12Z MONDAY. HIGH PRESSURE OVR THE REGION SHOULD ENSURE A NEAR CERTAINTY OF VFR CONDS FOR THE REST OF THE DAY. OUTLOOK... TUE-WED...MAINLY VFR. NO SIG WX EXPECTED. THU...MAINLY VFR...BUT A FEW SHOWERS POSSIBLE...MAINLY N PA. FRI...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...GARTNER/STEINBUGL AVIATION...FITZGERALD/LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
358 PM EDT SUN OCT 18 2015 .SYNOPSIS... A DEEP UPPER LEVEL TROUGH OVER EASTERN CANADA WILL LIFT OUT...LEADING TO A MILDER WEATHER PATTERN WITH LIMITED OPPORTUNITIES FOR RAIN FOR MUCH OF THE UPCOMING WEEK...WITH TEMPERATURES RISING NEAR TO ABOVE NORMAL FOR LATE OCTOBER. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... RADAR IS FILLED WITH FAST MOVING SCATTERED SHOWERS. LOCALLY WE ARE VARYING BETWEEN THE UPPER 30S AND LOWER 40S DEPENDING ON WHETHER WE HAVE PRECIPITATION IN PROGRESS...WITH IT TENDING TOWARD WET SNOW WHEN IT IS ACTUALLY DOING SOMETHING. THE HRRR INDICATES THESE SHOWERS WILL MAX OUT HERE IN THE NEXT HOUR OR TWO BEFORE DWINDLING AS THE UPPER FORCING ASSOCIATED WITH THE LEFT JET EXIT REGION SWINGS OFF TO OUR EAST. THE GREATEST RISK FOR SNOW TO ACTUALLY WHITEN THE GROUND...ESPECIALLY ON GRASSY SURFACES...WILL BE DOWNWIND OF LAKE ERIE OVER THE HIGHER ELEVATIONS OF THE ALLEGHENY FOREST REGION. MORE DOWNWIND OUT OF THE NORTHERN HIGHER ELEVATIONS...WET SNOW OR A MIX OF RAIN AND SNOW WILL MEAN MOST AREAS WILL NOT EXPERIENCE ANY SNOW ACCUMS. HIGH PRESSURE WILL MIGRATE EWD FROM THE LWR OH VALLEY LATER TODAY AND BE CENTERED OVER THE MD/WV PANHANDLE BY 12Z MONDAY. THE INCREASING LARGE SCALE SUBSIDENCE AND BACKING LOW LEVEL TRAJECTORIES WILL SPELL AN END TO THE LAKE EFFECT SHOWER ACTIVITY. MORE IMPORTANTLY THERE SHOULD ALSO BE A DECREASE IN CLOUD COVER...SETTING THE STAGE FOR A WIDESPREAD KILLING FREEZE. HAVE CONTINUED THE FREEZE WARNING WITH HIGH CONFIDENCE IN ENDING THE GROWING SEASON. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... HIGH PRESSURE WILL SETTLE OFF TO THE SOUTHEAST OF THE REGION MONDAY...ALLOWING A MILDER SOUTHWEST FLOW TO DEVELOP. IT SHOULD LEAD TO A BRIGHT DAY WITH HIGHS REBOUNDING...AVERAGING SOME 5 TO 15 DEGREES WARMER THAN TODAY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... UPPER TROF CURRENTLY OVER THE NERN NORTH AMERICA IS FORECAST TO LIFT/PROGRESS EWD THROUGH EARLY THIS WEEK. UPPER LONGWAVE TROF ALONG THE WEST COAST IS FORECAST TO DROP SOUTH AND CLOSE OFF OVER THE DESERT SW. THIS WILL ALLOW HEIGHT TO RISE SLOWLY OVER THE EASTERN HALF OF THE COUNTRY THROUGH THE WEEK...BUT AN ACTIVE NRN STREAM PATTERN SHOULD KEEP THE UPPER RIDGE OVER THE CENTRAL AND SERN U.S. FROM EXPANDING TOO FAR NORTH. A MILDER SPLIT-FLOW WEATHER PATTERN IS EXPECTED TO DEVELOP AND PERSIST THROUGH MUCH OF NEXT WEEK. THE GLOBAL MODELS AND ENSEMBLE PREDICTION SYSTEMS INDICATE THAT PCPN OPPORTUNITIES WILL REMAIN VERY LIMITED ACROSS THE AREA. THAT SAID THERE IS SOME SPREAD IN KEY SYNOPTIC FEATURES OVER THE LOWER 48...NAMELY THE NRN STREAM SHORTWAVE EVOLUTION CROSSING SERN CANADA/GRT LKS REGION AROUND THURSDAY. THE 18/00Z ECMWF IS DEEPER/SLOWER WITH THE H5 SYSTEM AND FAVORS A MORE PRONOUNCED MID LEVEL TROUGH IN THE NORTHEAST THURS NGT-FRI. THE GFS/GEFS AND GEM ARE MORE PROGRESSIVE WITH THE NRN STREAM WAVE WHICH ALLOWS UPPER RIDGING TO BULGE NWD FROM THE GOMEX. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... SATELLITE SHOWS A FAIRLY TYPICAL COOL SEASON SHIELD OF STRATO-CU CLOUDINESS UNDER THE COLD CYCLONIC FLOW AROUND THE DEEP UPPER LOW OVER EASTERN CANADA. WE WILL SEE THIS PATTERN BE REPEATED MANY TIMES OVER THE NEXT SEVERAL MONTHS. MVFR CEILINGS WILL TEND TO FAVOR THE HIGHER ELEVATION TERMINALS WITH BRIEF REDUCTIONS TO IFR POSSIBLE EVEN DOWN INTO CENTRAL AREAS AS FAST MOVING CELLULAR SHOWERS RACE TO THE SOUTHEAST. CONDITIONS WILL IMPROVE LATER TODAY INTO THE EVENING AS HIGH PRESSURE MOVES EASTWARD AND SHUTS OFF THE COLD LAKE EFFECT FLOW. THE WIND WILL WEAKEN AND BECOME LIGHT AND VARIABLE OVERNIGHT. OUTLOOK... MON-WED...MAINLY VFR. NO SIG WX EXPECTED. THU...MAINLY VFR...BUT A FEW SHOWERS POSSIBLE...MAINLY N PA. FRI...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...GARTNER/STEINBUGL AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
218 PM EDT SUN OCT 18 2015 .SYNOPSIS... A DEEP UPPER LEVEL TROUGH OVER EASTERN CANADA WILL LIFT OUT...LEADING TO A MILDER WEATHER PATTERN WITH LIMITED OPPORTUNITIES FOR RAIN FOR MUCH OF THE UPCOMING WEEK...WITH TEMPERATURES RISING NEAR TO ABOVE NORMAL FOR LATE OCTOBER. && .NEAR TERM /THROUGH TONIGHT/... RADAR IS FILLED WITH FAST MOVING SCATTERED SHOWERS. LOCALLY WE ARE VARYING BETWEEN THE UPPER 30S AND LOWER 40S DEPENDING ON WHETHER WE HAVE PRECIPITATION IN PROGRESS...WITH IT TENDING TOWARD WET SNOW WHEN IT IS ACTUALLY DOING SOMETHING. THE HRRR INDICATES THESE SHOWERS WILL MAX OUT HERE IN THE NEXT HOUR OR TWO BEFORE DWINDLING AS THE UPPER FORCING ASSOCIATED WITH THE LEFT JET EXIT REGION SWINGS OFF TO OUR EAST. THE GREATEST RISK FOR SNOW TO ACTUALLY WHITEN THE GROUND...ESPECIALLY ON GRASSY SURFACES...WILL BE DOWNWIND OF LAKE ERIE OVER THE HIGHER ELEVATIONS OF THE ALLEGHENY FOREST REGION. MORE DOWNWIND OUT OF THE NORTHERN HIGHER ELEVATIONS...WET SNOW OR A MIX OF RAIN AND SNOW WILL MEAN MOST AREAS WILL NOT EXPERIENCE ANY SNOW ACCUMS. HIGH PRESSURE WILL MIGRATE EWD FROM THE LWR OH VALLEY LATER TODAY AND BE CENTERED OVER THE MD/WV PANHANDLE BY 12Z MONDAY. THE INCREASING LARGE SCALE SUBSIDENCE AND BACKING LOW LEVEL TRAJECTORIES WILL SPELL AN END TO THE LAKE EFFECT SHOWER ACTIVITY. MORE IMPORTANTLY THERE SHOULD ALSO BE A DECREASE IN CLOUD COVER...SETTING THE STAGE FOR A WIDESPREAD KILLING FREEZE. HAVE CONTINUED THE FREEZE WARNING WITH HIGH CONFIDENCE IN ENDING THE GROWING SEASON. && .SHORT TERM /MONDAY/... HIGH PRESSURE WILL SETTLE OFF TO THE SOUTHEAST OF THE REGION MONDAY...ALLOWING A MILDER SOUTHWEST FLOW TO DEVELOP. IT SHOULD LEAD TO A BRIGHT DAY WITH HIGHS REBOUNDING...AVERAGING SOME 5 TO 15 DEGREES WARMER THAN TODAY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... A MILDER SPLIT-FLOW WEATHER PATTERN IS EXPECTED TO DEVELOP AND PERSIST THROUGH MUCH OF NEXT WEEK. THE GLOBAL MODELS AND ENSEMBLE PREDICTION SYSTEMS INDICATE THAT PCPN OPPORTUNITIES WILL REMAIN VERY LIMITED ACROSS THE AREA. THAT SAID THERE IS SOME SPREAD IN KEY SYNOPTIC FEATURES OVER THE LOWER 48...NAMELY THE NRN STREAM SHORTWAVE EVOLUTION CROSSING SERN CANADA/GRT LKS REGION AROUND THURSDAY. THE 18/00Z ECMWF IS DEEPER/SLOWER WITH THE H5 SYSTEM AND FAVORS A MORE PRONOUNCED MID LEVEL TROUGH IN THE NORTHEAST THURS NGT-FRI. THE GFS/GEFS AND GEM ARE MORE PROGRESSIVE WITH THE NRN STREAM WAVE WHICH ALLOWS UPPER RIDGING TO BULGE NWD FROM THE GOMEX. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... SATELLITE SHOWS A FAIRLY TYPICAL COOL SEASON SHIELD OF STRATO-CU CLOUDINESS UNDER THE COLD CYCLONIC FLOW AROUND THE DEEP UPPER LOW OVER EASTERN CANADA. WE WILL SEE THIS PATTERN BE REPEATED MANY TIMES OVER THE NEXT SEVERAL MONTHS. MVFR CEILINGS WILL TEND TO FAVOR THE HIGHER ELEVATION TERMINALS WITH BRIEF REDUCTIONS TO IFR POSSIBLE EVEN DOWN INTO CENTRAL AREAS AS FAST MOVING CELLULAR SHOWERS RACE TO THE SOUTHEAST. CONDITIONS WILL IMPROVE LATER TODAY INTO THE EVENING AS HIGH PRESSURE MOVES EASTWARD AND SHUTS OFF THE COLD LAKE EFFECT FLOW. THE WIND WILL WEAKEN AND BECOME LIGHT AND VARIABLE OVERNIGHT. OUTLOOK... MON-WED...MAINLY VFR. NO SIG WX EXPECTED. THU...MAINLY VFR...BUT A FEW SHOWERS POSSIBLE...MAINLY N PA. FRI...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...STEINBUGL AVIATION...LA CORTE