Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/25/15


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
845 PM MST MON AUG 24 2015 .SYNOPSIS... HIGH PRESSURE HAS BECOME REESTABLISHED TO THE NORTHEAST OF ARIZONA...WHICH WILL RESULT IN HIGHER THAN NORMAL RAIN CHANCES ACROSS THE LOWER DESERTS THROUGH TUESDAY. DRIER CONDITIONS WILL SLOWLY RETURN BY THE MIDDLE AND END OF THE WEEK ALONG WITH ABOVE NORMAL TEMPERATURES. WELL ABOVE NORMAL TEMPERATURES ARE POSSIBLE BY THE WEEKEND. && .DISCUSSION... A BIT OF A DOWN-DAY MONSOON-WISE ACROSS SOUTH-CENTRAL ARIZO0NA SO FAR HIS EVENING WHEN COMPARED WITH YESTERDAY. ALTHOUGH THUNDERSTORMS DID DEVELOP AS FORECAST ACROSS THE RIM COUNTY AND WHITE MOUNTAINS THIS AFTERNOON...WITH THESE STORMS TRYING TO MOVE INTO THE LOWER ELEVATIONS...DRIER AIR IN THE MID-LEVELS OF THE ATMOSPHERE THAT WAS ADVECTED SOUTHWESTWARD INTO THE LOWER DESERTS OF SOUTH-CENTRAL ARIZONA HAS SO FAR KEPT THUNDERSTORM ACTIVITY QUITE LIMITED ACROSS THE LOWER DESERTS...WITH MOST OF THE ACTIVITY LIMITED TO EXTREME NORTH AND NORTHWEST MARICOPA COUNTY. GIVEN THESE TRENDS...HAVE DECIDED TO CUT BACK POPS FOR THE REST OF THE EVENING ACROSS THE LOWER DESERTS. AS FAR AS THE FORECAST FOR THE REST OF THE NIGHT AND EARLY TUESDAY...HAVE DECIDED TO LEAVE OUR CURRENT ELEVATED POPS ALONE ACROSS SOUTHWEST AZ LATER TONIGHT AND EARLY TUESDAY...SINCE THE LATEST HIGH-RES MODEL RUNS CONTINUE TO SHOW DEBRIS CLOUDS AND SHOWERS FROM STORMS OVER NORTHERN MEXICO MOVING NORTHWARD AS A WEAK SHORTWAVE MOVES INTO THE REGION...WITH THESE SAME MODELS SHOWING MORE THUNDERSTORM DEVELOPMENT TUESDAY AFTERNOON OVER SOUTH-CENTRAL AZ. && .PREVIOUS DISCUSSION... PREDOMINANT MIDLEVEL SUBTROPICAL HIGH PRESSURE HAS BECOME ESTABLISHED OVER FAR SOUTHEAST UTAH THIS AFTERNOON...WITH A COMBINATION OF WEAK MCVS AND INVERTED TROUGHS ROTATING ABOUT THE SRN PERIPHERY OF THIS ANTI-CYCLONE IN NRN MEXICO. 12Z REGIONAL SOUNDINGS DEPICTED EROSION OF CAPPING ALOFT WITH MOIST H5 TEMPERATURES COOLING TO -7C TO -8C YIELDING MIDLEVEL LAPSE RATES STEEPER THAN USUAL FOR THE MONSOON SEASON. ON THE OTHER HAND...SFC- H7 MOISTURE LEVELS WERE SAMPLED SLIGHTLY LOWER THAN THE PAST COUPLES DAYS (ONLY 10-11 G/KG) LEADING TO MLCAPES SUBSTANTIALLY LOWER ONLY AROUND 500 J/KG. SEVERAL CONFLICTING SIGNALS REGARDING CONVECTIVE COVERAGE AND PROPAGATION THIS AFTERNOON AND EVENING. OBJECTIVELY ANALYZED DEEP EASTERLY OR NORTHEASTERLY FLOW WOULD GENERALLY PROMOTE DEEPER OUTFLOW BOUNDARIES MARCHING INTO LOWER ELEVATIONS FROM HIGH TERRAIN STORM INITIATION POINTS. HOWEVER...THE NORTHEASTERLY TRAJECTORY HAS ACTUALLY BEEN ADVECTING SLIGHTLY DRIER AIR OVER HIGH TERRAIN...LOWERING INSTABILITY AND HINDERING ORGANIZED STORM FORMATION. STRONGER JET LEVEL DIFFLUENCE WAS LOCATED IN NRN MEXICO...AND SHOULD BEGIN FORMULATING NORTHWARD BUT POSSIBLY NOT UNTIL LATER THIS EVENING AIDING IN LARGE SCALE ASCENT. MORNING TRENDS IN THE HRRR AS WELL AS 12Z LOCAL WRF CORES SUGGESTED INCREASING CONFIDENCE OF DEEP CONVECTION ERUPTING THROUGHOUT THE MOGOLLON RIM AND WHITE MOUNTAINS...WITH FAVORABLE STEERING FLOW BRINGING DEEP OUTFLOWS AND LINEAR ASCENT TOWARDS THE PHOENIX METRO. HOWEVER...LATEST HRRR TRENDS AND EARLY/MID AFTERNOON RADAR IMAGERY YIELD HIGHER UNCERTAINTY ESPECIALLY WITH SFC DEWPOINTS NOW FALLING INTO THE MID/UPPER 50S. SHOULD MORE BACKED WINDS UPSTREAM AT H7 AND BETTER MOISTURE IN THIS LAYER BE ADVECTED WESTWARD...THAN MORE WIDESPREAD THUNDERSTORMS WOULD BE POSSIBLE. REGARDLESS...ANY ACTIVITY AFFECTING CNTRL ARIZONA MAY BE MORE DELAYED INTO THE EVENING HOURS. BY TUESDAY AND WEDNESDAY...THE THREAT FOR SCATTERED SHOWER AND STORM ACTIVITY WILL CONTINUE NEARLY AREAWIDE...PEAKING TUESDAY AS A MORE PRONOUNCED UPSTREAM INVERTED TROUGH AND SYNOPTIC SCALE UPPER DIVERGENCE ROTATES THROUGH THE FORECAST AREA. MODELS INDICATE DEEP MOISTURE PROFILES PUSHING BEHIND CONVECTIVE OUTFLOW EARLY TUESDAY MORNING...WITH PWATS IN A 1.75 TO 2 INCH RANGE (NEARLY THE 90TH PERCENTILE OF NAEFS MEAN). ALONG WITH THE ELEVATED POP CHANCES...SIGNIFICANT DAYTIME CLOUD COVER SHOULD WORK TO LIMIT DAYTIME HIGHS...OR AT LEAST DRAWING THEM BACK TO SEASONAL NORMALS /104 FOR PHOENIX AND 106 FOR YUMA/. HIGH TEMPERATURES COULD EASILY BE COOLER FOR LOCALES AFFECTED BY THICKER CLOUD COVER AND RAIN- COOLED OUTFLOWS...AND BUFR SOUNDINGS AND ENSEMBLE MAJORITY MODEL OUTPUT SUPPORT SUB-100 DEGREE HIGHS OVER MUCH OF SOUTHEAST CALIFORNIA. PRECIPITATION CHANCES WILL BEGIN TO DECREASE WEST TO EAST ON WEDNESDAY AND FOCUS MORE ACROSS THE FOUR CORNERS REGION AS THE AFOREMENTIONED TROUGH/SHORTWAVE SHIFTS NORTH IN RESPONSE TO THE REPOSITIONING RIDGE CENTER. THE RIDGE WILL BEGIN TO TRANSITION ACROSS NM DURING THE DAY WEDNESDAY AND GRADUALLY SINK SOUTHWARD INTO OLD MEXICO LATE WEDNESDAY INTO THURSDAY. ML AND UL FLOW WILL GRADUALLY TAKE UP SOUTHWESTERLY HEADINGS AGAIN...ONLY SLOWLY THINNING AND DRAWING DOWN MOISTURE THROUGH THE COLUMN. AS A RESULT...POP CHANCES START DECREASING MORE NOTABLY BEGINNING THURSDAY. AS THE UPPER HIGH SETTLES BACK TO OUR SOUTH AND DEWPOINTS/PWATS CONTINUE TO THIN...AIRMASS TEMPERATURES BEGIN TO WARM PROMPTING SFC TEMPERATURES TO ABOVE NORMAL READINGS BY THURSDAY AND THROUGH THE WEEKEND. THE WARMEST WESTERN DESERTS...INCLUDING EL CENTRO...YUMA AND TACNA...COULD HIT THE 110F MARK BY FRIDAY AND A DEGREE OR TWO WARMER BY THE WEEKEND. MEANWHILE LOCATIONS AROUND SOUTH-CENTRAL AZ...INCLUDING THE PHX METRO AND GILA BEND...COULD POTENTIALLY REACH THE 110F MARK BY THE WEEKEND. OVER THE LAST NORMAL PERIOD /1981- 2010/ THE AVERAGE LAST 110F DAY IN PHOENIX FALLS ON AUGUST 26TH /SEPTEMBER 6TH FOR YUMA/. WE COULD CERTAINLY PUSH PAST THE AVERAGE LAST DAY IN THE PHOENIX AREA BY THE WEEKEND...AND WORK TO CINCH THE TOP SPOT FOR THE WARMEST AUGUST ON RECORD AT BOTH LOCALES TO CLOSE OUT THE MONTH. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... A FEW AFTERNOON AND EVENING THUNDERSTORMS WILL DEVELOP OVER THE DISTANT MOUNTAINS NORTH THROUGH SOUTHEAST OF THE GREATER PHOENIX AREA. THERE IS A SLIGHT CHANCE OF AN ISOLATED THUNDERSTORMS REDEVELOPING OVER THE PHOENIX AREA ALONG WEAK CONVECTIVE OUTFLOW BOUNDARIES. THROUGH 04Z TUE...WEST WIND 8 TO 12 KNOTS...SCT TO BKN CLDS AOA 14 THSD MSL. ISOLD TSTM POSSIBLE. FROM 04Z TUE THROUGH 18Z THU...LGT EAST WIND UNDER 9 KNOTS. BKN CLDS AOA 14 THSD MSL. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... THROUGH 04Z TUE...SCT-BKN CLDS AOA 14 THSD MSL. ISOLATED TSTM. SOUTH TO SOUTHWEST WIND 8 TO 12 KNOTS. FROM 04Z TUE TO 18Z TUE...SOUTH WIND 6 TO 10 KNOTS. SCT-BKN CLDS AOA 16 THSD MSL. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... WEDNESDAY THROUGH SUNDAY... ISOLATED SHOWERS AND THUNDERSTORMS WILL PERSIST WEDNESDAY AS FAR WEST AS SOUTHERN CALIFORNIA AS MOISTURE REMAINS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM. THEREAFTER...THE GENERAL TREND WILL BE TOWARDS DRIER AND WARMER CONDITIONS AS HIGH PRESSURE DRIFTS BACK TO THE SOUTH AND WEST. THE RESULTING SOUTHWESTERLY FLOW WILL RELEGATE ISOLATED STORM ACTIVITY PRIMARILY TO THE HIGHER TERRAIN OF EASTERN ARIZONA THURSDAY AND FRIDAY. ABOVE NORMAL TEMPERATURES AND BELOW NORMAL HUMIDITIES ARE EXPECTED BY FRIDAY AND WILL CONTINUE THROUGH THE WEEKEND. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT AND TERRAIN- DRIVEN AND CONSEQUENTLY AN ELEVATED FIRE DANGER IS NOT ANTICIPATED. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...MO/NOLTE AVIATION...VASQUEZ FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION...UPDATE
NWS TUCSON AZ
1150 AM MST SUN AUG 23 2015 .SYNOPSIS...CONDITIONS ARE STILL FAVORABLE FOR AN INCREASE IN THE STRENGTH AND COVERAGE OF STORMS LATER TODAY AND MONDAY...ALTHOUGH SOME VALLEY DEVELOPMENT WILL BE DELAYED. SOME STORMS WILL GENERATE STRONG WINDS AND HEAVY RAIN. THE INCREASED MOISTURE WILL ALSO KEEP DAYTIME TEMPERATURES CLOSER TO SEASONAL AVERAGES. FOR THE SECOND HALF OF THE NEW WEEK...BUILDING HIGH PRESSURE WILL TEND TO SUPPRESS THUNDERSTORM COVERAGE WHILE BRINGING HOTTER TEMPERATURES TO THE AREA. && .UPDATE...THE 18Z SOUNDING HAS MAINTAINED A NICE WIND PROFILE WITH DECENT STORM LEVEL FLOW AND BETTER SHEAR THAN RECENT DAYS. SIGNS OF RECOVERY COMPARED TO 12Z WITH MODIFIED MIXED LAYER CAPE PUSHING 800 AND CONVECTIVE INHIBITION FALLING TO SLIGHTLY MORE MANAGEABLE LEVELS. WHILE WE PROBABLY WON`T REACH CONVECTIVE INITIATION VERY EASILY IN VALLEY LOCATIONS THE SOUNDING APPEARS TO BE RESPONSIVE ENOUGH TO OUTFLOWS. OUR CURRENT FORECAST WILL STAND PAT WITH THE IDEA OF SLOWER VALLEY DEVELOPMENT LARGELY DEPENDENT ON VIGOROUS ORGANIZED OUTFLOW FROM THE EAST AND NORTHEAST. STILL LOOKING FOR DUST BECOMING AN ISSUE WITH FAVORED AREAS MAINLY IN PINAL COUNTY AND NORTHERN PORTIONS OF THE TOHONO O`ODHAM NATION. FORECAST UPDATE OUT SHORTLY WILL FURTHER REDUCE THE CHANCE OF VALLEY STORMS IN THE AFTERNOON HOURS FOR MANY LOCATIONS. && .DISCUSSION...THE 12Z KTWC SOUNDING IS A BIT WORKED OVER AS EXPECTED. CURRENT THINKING IS THAT IT WILL RECOVER ENOUGH FOR STRONG EASTERLY/NORTHEASTERLY OUTFLOW TO FIRE CONVECTION ACROSS METRO TUCSON AGAIN LATE IN THE AFTERNOON OR EARLY EVENING. WE WILL SEE HOW THE ATMOSPHERE IS PROGRESSING WITH AN 18Z RELEASE IN A LITTLE WHILE. LATEST HRRR CONTINUES TO BACK-PEDAL ON STORM CHANCES TODAY WHILE THE 12Z STANDARD GFS/NAM RUNS WERE MORE FAVORABLE SUSTAINING DEEP OUTFLOW FROM THE EAST INTO LOWER DESERT LOCATIONS DURING LATE AFTERNOON AND EVENING HOURS. THIS REMAINS OUR CURRENT FORECAST SCENARIO PENDING THE PROGRESS REPORT FROM THE 18Z SOUNDING. WE`RE ALSO LOOKING AT THE ORIENTATION OF THE EXPECTED OUTFLOWS FROM CONVECTION IN EASTERN AREAS FOR POSSIBLE LARGE SCALE BLOWING DUST CONCERNS...ESPECIALLY IN PINAL COUNTY. PLEASE SEE THE PREVIOUS DISCUSSION FOR ADDITIONAL DETAILS. && .AVIATION...VALID THRU 24/18Z. MAINLY W OF KTUS...FEW-SCTD 8-12KFT OTRW CLR. FROM KTUS S AND E... SCTD TO LCLY BKN CLOUDS AT 8-12K FT. AFT 23/19Z ISOLD TO SCTD -SHRA/TS. AFT 24/00Z SCT-BKN 8-10K FT AREA WIDE WITH BKN LYRS ABV AND SCT SHRA/TSRA. BRIEF MVFR CONDS...ALONG WITH STRONG GUSTY WINDS POSSIBLE IN AN AROUND SHRA/TSRA. WINDS AWAY FROM STORMS GENERALLY LIGHT AND TERRAIN DRIVEN. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...GOOD THUNDERSTORM CHANCES LATER TODAY WELL INTO TONIGHT THEN AGAIN MONDAY AS A DISTURBANCE MOVES NW ACROSS THE REGION. DECENT STORM CHANCES REMAIN TUESDAY INTO WEDNESDAY DUE TO PLENTY OF MOISTURE LINGERING OVER THE REGION. AN UPPER RIDGE WILL BUILD OVER THE AREA LATE IN THE WEEK INTO NEXT WEEKEND RESULTING IN A SIGNIFICANT DECREASE IN SHOWER AND THUNDERSTORMS AND TEMPERATURES RISING TO NEAR RECORD LEVELS FRIDAY ONWARD. OUTSIDE OF THUNDERSTORM WINDS...WINDS WILL BE TYPICAL FOR MID AUGUST AND GENERALLY LESS THAN 15 MPH WITH AFTERNOON GUSTINESS. && .DISCUSSION...WATER VAPOR IMAGERY...23/00Z UPPER-AIR PLOTS AND LATEST MODEL DATA INDICATE THAT HIGH PRESSURE EXTENDS GENERALLY FROM SRN CALIFORNIA/NRN BAJA ACROSS THE DESERT SOUTHWEST AND INTO NEW MEXICO. TROUBLE WITH UPPER-AIR BALLOON LAUNCHES YESTERDAY AFTERNOON RESULTED IN NO FLIGHT FOR KTWC AND A SHORT FLIGHT FROM KPSR (ONLY UP TO AROUND 620MB)...SO NO PW INFO FROM THAT SOURCE. HOWEVER...THE U OF A GPS PW VALUES SHOW AROUND 1.2 INCHES FOR TUS AND SIMILAR VALUES FROM THE SATELLITE DERIVED BLENDED TOTAL PW IMAGERY. IR SATELLITE IMAGERY SHOWS LINGERING CONVECTION WELL TO OUR EAST OVER SOUTH CENTRAL NEW MEXICO...WITH MID TO HIGH LEVEL DEBRIS CLOUDS EXTENDING WESTWARD INTO SOUTHEAST ARIZONA AS FAR AS THE TUCSON AREA. THESE CLOUDS SHOW SIGNS OF ERODING. MODELS INDICATE THAT THE HIGH SHIFTS TO A POSITION THAT EXTENDS FROM ARIZONA THROUGH NEW MEXICO AND INTO EASTERN TEXAS TODAY. AS THIS OCCURS FLOW WILL BECOME EAST TO SOUTHEAST WITH A WEAK DISTURBANCE PROGGED TO MOVE ACROSS NORTHERN CHIHUAHUA MEXICO AND ACROSS THE ARIZONA/SONORAN BORDER THIS AFTERNOON THROUGH LATE MONDAY AS IT MOVES TOWARD THE LOWER COLORADO RIVER BASIN. MODELS ARE ADVERTISING THE PW`S TO INCREASE TO AROUND 1.4-1.6 INCHES TODAY FOR TUCSON WITH LESSER VALUES EAST. BY MONDAY VALUES EXPECTED TO RANGE FROM 1.2-1.4 INCHES EAST...1.5-1.6 INCHES CENTRAL AREAS AND 1.8-2.0 INCHES FOR THE FAR WEST (AJO/ORGAN PIPE). WITH THE COMBO OF AMPLE MOISTURE AND THE AFOREMENTIONED TRIGGERING MECHANISM OF THE WEAK VORT MAX TRAVERSING SOUTHERN ARIZONA...EXPECT SCATTERED TO LOCALLY NUMEROUS SHOWERS AND THUNDERSTORMS TODAY THROUGH MONDAY...WITH THE BEST THREAT OCCURRING LATE THIS AFTERNOON AND THIS EVENING...BUT STILL A DECENT THREAT AGAIN MONDAY AFTERNOON/EVENING. BY TUESDAY RAIN CHANCES IN THE LOW END SCATTERED CATEGORY NEARLY AREA WIDE AS THE WEAK DISTURBANCE MOVES UP THE COLORADO RIVER VALLEY AS THE HIGH SHIFTS TO A POSITION OVER EASTERN COLORADO. SO... WITHOUT THAT ENHANCEMENT STILL STORMS AROUND...BUT NOT AS NUMEROUS AS WHAT IS EXPECTED FOR TODAY AND MONDAY. BY WEDNESDAY THE HIGH IS EXPECTED TO MOVE TO NEW MEXICO/WEST TEXAS WITH PW`S EXPECTED TO BE DOWN FROM PREVIOUS DAYS...GENERALLY IN THE 1.1 TO 1.4 INCH RANGE FOR EAST AND CENTRAL LOCATIONS. FOR THURSDAY AND CONTINUING THROUGH SATURDAY...THE HIGH IS EXPECTED TO SHIFT TO A POSITION NEARLY OVERHEAD OR JUST TO OUR SOUTH...GIVING US A DRIER SOUTHWESTERLY FLOW ALOFT...WITH PW`S DROPPING TO AROUND THE 1 INCH MARK BY SATURDAY. THAT SAID...I TWEAKED THE POP FORECAST FOR LATE IN THE PERIOD TO GIVE US MAINLY ISOLATED TO LOW END SCATTERED ACTIVITY MAINLY NEAR THE NEW MEXICO BORDER FOR FRIDAY AND SATURDAY. FOR TUCSON...HIGH TEMPS WILL GENERALLY BE NEAR NORMAL TODAY AND MONDAY...THEN 1 TO 3 DEGS ABOVE NORMAL TUESDAY AND WEDNESDAY...THEN 5 TO 7 DEGS ABOVE NORMAL THURSDAY THROUGH SATURDAY. LOWS WILL RANGE FROM 3 TO 6 DEGS ABOVE NORMAL...BUT THE WARMEST MORNINGS WILL LIKELY OCCUR LATE NEXT WEEK AND WEEKEND. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE/DISCUSSION...MEYER AVIATION/FIRE WEATHER...CERNIGLIA PREVIOUS DISCUSSION...MOLLERE VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
945 AM MST SUN AUG 23 2015 .SYNOPSIS... HIGH PRESSURE WILL BECOME REESTABLISHED TO OUR EAST...RESULTING IN HIGHER THAN NORMAL RAIN CHANCES ACROSS THE LOWER DESERTS THROUGH TUESDAY. DRIER CONDITIONS WILL RETURN BY MIDWEEK ALONG WITH ABOVE NORMAL TEMPERATURES. WELL ABOVE NORMAL TEMPERATURES ARE POSSIBLE BY NEXT WEEKEND. && .DISCUSSION... VERY COMPLEX FORECAST THROUGH THE NEXT 24 HOURS AS PATTERN REALIGNMENT...SHIFTING AND VARIABLE STEERING FLOW...INSTABILITY GRADIENTS...MOISTURE AVAILABILITY...AND INVERTED TROUGHING MAY BEGIN TO COME TOGETHER TO ALLOW FOR ORGANIZED CONVECTION AND DEEPER OUTFLOWS TO AFFECT THE FORECAST AREA. 1) WV IMAGERY AND OBJECTIVE ANALYSIS CLEARLY SHOW A STACKED ANTI- CYCLONE NEAR THE NRN GULF OF CALIFORNIA THIS MORNING...WITH 12Z REGIONAL SOUNDING SAMPLING VARIABLE TO PREDOMINANTLY NELY FLOW IN THE H8-H5 LAYER. WITH THIS HIGH PRESSURE DOME REALIGNING TOWARDS THE 4-CORNERS...STEERING FLOW ALOFT SHOULD GENERALLY BACK TO AN E/SE DIRECTION THIS EVENING...SUPPORTING WESTWARD MAINTENANCE OF ANY DEEP OUTFLOWS GENERATED OVER ERN OR SERN ARIZONA. 2) 12Z KPSR AND KTWC SOUNDINGS ONCE AGAIN SHOWED GOOD 12 G/KG MIXING RATIOS IN THE SFC-800MB LAYER...THOUGH DROPPING OFF ABOVE H7. MORE BACKED FLOW IN THE H8-H5 LAYER SHOULD LESSEN THE EFFECTS OF DRY MIXING INTO THE BOUNDARY LAYER THIS AFTERNOON...AND AN UPSTREAM SLUG OF HIGHER MOISTURE (EVIDENCED BY ACCAS OVER ERN ARIZONA/WRN NEW MEXICO) MAY INFUSE BETTER MOISTURE AROUND THE CRITICAL H7/MIXING LAYER TOP LATER TODAY. HOWEVER...THIS CLOUD COVER AND CONVECTIVELY CONTAMINATED ATMOSPHERE HAVE SIGNIFICANTLY REDUCED INSTABILITY OVER ERN ARIZONA TODAY VERSUS THE PAST COUPLE DAYS. 3) A WEAK MIDLEVEL INVERTED TROUGH IS EVIDENT OVER NRN SONORA THIS MORNING...WHICH COULD AID IN LARGE SCALE ASCENT LATER TODAY. SOME MEASURE OF WLY JET STREAM FLOW IS NOTED IN OBJECTIVE ANALYSIS...THOUGH SUBJECTIVELY IT APPEARS DIFLUENCE AT THIS LEVEL MAY INCREASE THROUGH THE DAY IN SERN ARIZONA. THE PREPONDERANCE OF HIGH RESOLUTION CONVECTIVE MODELS STILL SHOW LIMITED CHANCES FOR PRECIPITATION BEYOND HIGHER ELEVATION LOCATIONS OVER GILA/PINAL COUNTIES...BUT RATHER LONG REACHING OUTFLOW BOUNDARIES MARCHING WEST THROUGH CNTRL (AND EVEN WRN) ARIZONA. BASED ON SOUNDING AND MLCAPE ANALYSIS...COULD NOT SEE ANY JUSTIFICATION TO INCREASE POPS...BUT RATHER MADE SOME SMALL DOWNWARD ADJUSTMENTS AROUND THE PHOENIX METRO. STILL THINKING LARGEST IMPACT THIS EVENING WOULD BE LOCALLY DENSE BLOWING DUST...WITH OUTFLOW BOUNDARIES USHERING BETTER DEEP MOISTURE PROFILES SETTING THE STAGE FOR MORE WIDESPREAD STORMS AND RAIN MONDAY AND TUESDAY. OTHERWISE IN THE SHORT TERM...MADE SOME MINOR ADJUSTMENTS TO HOURLY TEMPERATURE AND DEWPOINTS BASED ON OBSERVATIONAL TRENDS. && .PREVIOUS DISCUSSION... /455 AM MST SUN AUG 23 2015/ LATEST RAP STREAMLINE ANALYSIS SHOWS THE SUBTROPICAL RIDGE WEAKENING ACROSS THE BAJA PENINSULA AND MIGRATING EASTWARD...RESULTING IN A CESSATION OF THE PERSISTENT WESTERLY FLOW. A VERY WEAK STEERING FLOW WILL DEVELOP TODAY FOLLOWED BY A REVERSAL IN THE WINDS TO LIGHT EASTERLY BY TONIGHT. MEANWHILE...A VORT MAX ASSOCIATED WITH AN INVERTED TROUGH IS EVIDENT NEAR THE BOOTHEEL OF NM. THIS SETUP IS FAVORABLE FOR THUNDERSTORM ACTIVITY ACROSS EASTERN AND SOUTHEASTERN AZ TODAY WITH PROPAGATION TO THE WEST INTO SOUTH-CENTRAL AZ THIS EVENING. CONVECTIVELY PARAMETERIZED MODELS SUCH AS THE GFS...ECMWF AND NMM-B SUGGEST SOME POTENTIAL FOR THUNDERSTORMS ACROSS THE LOWER DESERTS INCLUDING THE PHOENIX AREA. HOWEVER...CONSENSUS AMONG THE CONVECTIVE ALLOWING WRFS IS THAT CONVERGING OUTFLOW BOUNDARIES WILL PRODUCE ONLY ISOLATED CONVECTION ACROSS THE PHOENIX AREA...BUT WITH PERHAPS HIGHER PROBABILITIES ACROSS THE SOUTHWEST DESERTS. MOST LIKELY IMPACT TONIGHT IS BLOWING DUST...THOUGH THE POTENTIAL CERTAINLY EXISTS FOR THUNDERSTORMS CONTAINING STRONG WINDS AND DOWNBURSTS...PARTICULARLY ACROSS PORTIONS OF MARICOPA AND PINAL COUNTIES. WITH THE INVERTED TROUGH DRAPED ACROSS THE LOWER DESERTS OVERNIGHT...CONVECTION ALSO CANNOT BE RULED OUT THROUGH MONDAY MORNING. BEST CHANCE FOR PRECIPITATION APPEARS TO BE MONDAY AS THE MONSOON HIGH DRIFTS TOWARDS THE FOUR CORNERS RESULTING IN A MOIST SOUTHEASTERLY FLOW. MODELS ALSO INDICATE THAT THE 250 MB HIGH DISPLACED TO THE SOUTH WILL PRODUCE A DIFLUENT AND DIVERGENT PATTERN IN THE UPPER LEVELS...HELPING TO PROVIDE ASCENT WHICH MAY OFFSET ANY LACK OF INSTABILITY DUE TO THE WIDESPREAD CLOUDINESS. THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL PERSIST TUESDAY BUT WILL SHIFT SOMEWHAT TO THE WEST. LATEST MODELS SUGGEST THAT SEVERAL TRAILING VORT MAXES AND MCVS WILL PROVIDE ASCENT IN A RELATIVELY STRONG AND MOIST SOUTHERLY FLOW. THE FOCUS FOR PRECIPITATION WILL SHIFT NORTHWARD WEDNESDAY AS THE AFOREMENTIONED TROUGH ACCELERATES NORTHEASTWARD AROUND THE ANTICYCLONE IN NM. GFS/ECMWF ARE IN GOOD AGREEMENT THAT THE RIDGE WILL AGAIN MIGRATE TO OUR SOUTH LATE IN THE WEEK...RESULTING IN A SOUTHWESTERLY FLOW AND A RETURN TO WARMER AND DRIER CONDITIONS. ABOVE NORMAL TEMPERATURES ARE LIKELY BEGINNING THURSDAY WITH HIGHS IN THE PHOENIX AREA POTENTIALLY REACHING 110 DEGREES AGAIN BY NEXT SATURDAY...AND EVEN WARMER ACROSS SOUTHEASTERN CA. THIS COULD BE THE WARMEST AUGUST ON RECORD FOR BOTH PHOENIX AND YUMA AND THE PERIOD OF ABOVE NORMAL TEMPERATURES TO END THE MONTH MAY HELP CLINCH THE TOP SPOT FOR BOTH LOCATIONS. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... MOSTLY CLEAR SKIES AND TYPICAL AM EASTERLY WINDS TO PERSIST THRU MIDDAY. WINDS TO GRADUALLY SWING AROUND TO W-SW PSBLY AN HOUR OR TWO EARLIER THAN THEIR USUAL EARLY AFTN WINDOW...PSBLY AS EARLY AS 23/18Z. TODAY BEGINS A SEVERAL-DAY RETURN PERIOD OF MORE FAVORABLE MONSOON STORM CHANCES ACROSS THE LOWER DESERTS AND SURVIVING INTO CORNERS OF THE PHX METRO TO START. HI-RES MODEL GUIDANCE AND EARLY AM CCFP INDICATE STORMS TO DEVELOP FIRST ALONG THE MOGOLLON RIM BY MIDDAY AND AN HOUR OR TWO LATER ACROSS SE AZ. INITIAL BEST GUESS AT TIMING THE FIRST...IN A POTENTIAL FEW...OUTFLOW INTRUSION...COULD BE BETWEEN THE 24/00-02Z WINDOW FROM EAST- NORTHEAST. ADDITIONAL OUTFLOW PUSH FROM THE SOUTH COULD EXPAND INTO THE PHX METRO POST 02Z...ALONG WITH ISO. POP-UP SHOWER AND STORM ACTIVITY WITH ITS PASSAGE. GNLY OPENED WITH VCSH AROUND 24/02-03Z TIMEFRAME FOR THE TERMINALS. VSBY REDUCTION IS PSBL EITHER IN SUSPENDED/LOFTED DUST OR A MORE CONSOLIDATED OUTFLOW AND THICKER DUST...BUT HELD OFF FROM INCLUDING VSBY REDUCTION IN THE 12Z TAF PACKAGE ATTM. DEPENDING ON WHERE THE OUTFLOW ORIGINATES WILL HAVE BEARING ON WHAT AMOUNT...IF ANY...DUST IT MANAGES TO PICK UP. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... MOSTLY CLEAR SKIES AND PERSISTENT SOUTH TO SOUTHEASTERLY WINDS FORECAST FOR THE WESTERN TERMINALS TODAY AND THIS EVENING. STORM ACTIVITY SHOULD STAY WILL TO THE EAST ACROSS AZ THIS AFTN/EVENING...WITH SOME PSBL HIGH LEVEL DEBRIS CLOUD IN LATER INTO THE OVERNIGHT FOR KBLH. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST TUESDAY AND WEDNESDAY AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE IN FROM THE SOUTHEAST. THESE DISTURBANCES WILL SUPPORT ELEVATED CHANCES FOR MORE WIDESPREAD AND SUBSTANTIAL STORM DEVELOPMENT REGION-WIDE...WITH STORM CHANCES REACHING BEYOND THE CO RIVER VALLEY. MIN RH VALUES WILL GENERALLY RANGE BETWEEN 20 TO 30 PERCENT WITH GOOD OVERNIGHT RECOVERY. OUTSIDE OF THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS WILL BEGIN TO FOLLOW TYPICAL DIURNAL/DRAINAGE DRIVEN TRENDS. A DRAW DOWN OF MONSOON MOISTURE IS STILL FORECAST TOWARDS THE END OF THE WEEK...BUT MAY OCCUR AT A SLOWER RATE THAN ORIGINALLY THOUGHT. THE UPPER RIDGE WILL GRADUALLY POSITION ITSELF TO DRAW IN DRIER WESTERLY FLOW ALOFT...RELEGATING STORM CHANCES BACK ACROSS THE EASTERN AZ AND THE HIGHER TERRAIN. AS THE AIRMASS SLOWLY DRIES OUT...DAYTIME TEMPERATURES WILL RISE TO ABOVE NORMAL VALUES AND IN SOME OF THE SOUTHEAST CA FIRE ZONES PUSH THE 110F MARK BY THE WEEKEND. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...MO/HIRSCH AVIATION...NOLTE FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST SUN AUG 23 2015 .SYNOPSIS...CONDITIONS ARE STILL FAVORABLE FOR AN INCREASE IN THE STRENGTH AND COVERAGE OF STORMS LATER TODAY AND MONDAY...ALTHOUGH SOME VALLEY DEVELOPMENT WILL BE DELAYED. SOME STORMS WILL GENERATE STRONG WINDS AND HEAVY RAIN. THE INCREASED MOISTURE WILL ALSO KEEP DAYTIME TEMPERATURES CLOSER TO SEASONAL AVERAGES. FOR THE SECOND HALF OF THE NEW WEEK...BUILDING HIGH PRESSURE WILL TEND TO SUPPRESS THUNDERSTORM COVERAGE WHILE BRINGING HOTTER TEMPERATURES TO THE AREA. && .DISCUSSION...THE 12Z KTWC SOUNDING IS A BIT WORKED OVER AS EXPECTED. CURRENT THINKING IS THAT IT WILL RECOVER ENOUGH FOR STRONG EASTERLY/NORTHEASTERLY OUTFLOW TO FIRE CONVECTION ACROSS METRO TUCSON AGAIN LATE IN THE AFTERNOON OR EARLY EVENING. WE WILL SEE HOW THE ATMOSPHERE IS PROGRESSING WITH AN 18Z RELEASE IN A LITTLE WHILE. LATEST HRRR CONTINUES TO BACK-PEDAL ON STORM CHANCES TODAY WHILE THE 12Z STANDARD GFS/NAM RUNS WERE MORE FAVORABLE SUSTAINING DEEP OUTFLOW FROM THE EAST INTO LOWER DESERT LOCATIONS DURING LATE AFTERNOON AND EVENING HOURS. THIS REMAINS OUR CURRENT FORECAST SCENARIO PENDING THE PROGRESS REPORT FROM THE 18Z SOUNDING. WE`RE ALSO LOOKING AT THE ORIENTATION OF THE EXPECTED OUTFLOWS FROM CONVECTION IN EASTERN AREAS FOR POSSIBLE LARGE SCALE BLOWING DUST CONCERNS...ESPECIALLY IN PINAL COUNTY. PLEASE SEE THE PREVIOUS DISCUSSION FOR ADDITIONAL DETAILS. && .AVIATION...VALID THRU 24/18Z. MAINLY W OF KTUS...FEW-SCTD 8-12KFT OTRW CLR. FROM KTUS S AND E... SCTD TO LCLY BKN CLOUDS AT 8-12K FT. AFT 23/19Z ISOLD TO SCTD -SHRA/TS. AFT 24/00Z SCT-BKN 8-10K FT AREA WIDE WITH BKN LYRS ABV AND SCT SHRA/TSRA. BRIEF MVFR CONDS...ALONG WITH STRONG GUSTY WINDS POSSIBLE IN AN AROUND SHRA/TSRA. WINDS AWAY FROM STORMS GENERALLY LIGHT AND TERRAIN DRIVEN. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...GOOD THUNDERSTORM CHANCES LATER TODAY WELL INTO TONIGHT THEN AGAIN MONDAY AS A DISTURBANCE MOVES NW ACROSS THE REGION. DECENT STORM CHANCES REMAIN TUESDAY INTO WEDNESDAY DUE TO PLENTY OF MOISTURE LINGERING OVER THE REGION. AN UPPER RIDGE WILL BUILD OVER THE AREA LATE IN THE WEEK INTO NEXT WEEKEND RESULTING IN A SIGNIFICANT DECREASE IN SHOWER AND THUNDERSTORMS AND TEMPERATURES RISING TO NEAR RECORD LEVELS FRIDAY ONWARD. OUTSIDE OF THUNDERSTORM WINDS...WINDS WILL BE TYPICAL FOR MID AUGUST AND GENERALLY LESS THAN 15 MPH WITH AFTERNOON GUSTINESS. CERNIGLIA && .DISCUSSION...WATER VAPOR IMAGERY...23/00Z UPPER-AIR PLOTS AND LATEST MODEL DATA INDICATE THAT HIGH PRESSURE EXTENDS GENERALLY FROM SRN CALIFORNIA/NRN BAJA ACROSS THE DESERT SOUTHWEST AND INTO NEW MEXICO. TROUBLE WITH UPPER-AIR BALLOON LAUNCHES YESTERDAY AFTERNOON RESULTED IN NO FLIGHT FOR KTWC AND A SHORT FLIGHT FROM KPSR (ONLY UP TO AROUND 620MB)...SO NO PW INFO FROM THAT SOURCE. HOWEVER...THE U OF A GPS PW VALUES SHOW AROUND 1.2 INCHES FOR TUS AND SIMILAR VALUES FROM THE SATELLITE DERIVED BLENDED TOTAL PW IMAGERY. IR SATELLITE IMAGERY SHOWS LINGERING CONVECTION WELL TO OUR EAST OVER SOUTH CENTRAL NEW MEXICO...WITH MID TO HIGH LEVEL DEBRIS CLOUDS EXTENDING WESTWARD INTO SOUTHEAST ARIZONA AS FAR AS THE TUCSON AREA. THESE CLOUDS SHOW SIGNS OF ERODING. MODELS INDICATE THAT THE HIGH SHIFTS TO A POSITION THAT EXTENDS FROM ARIZONA THROUGH NEW MEXICO AND INTO EASTERN TEXAS TODAY. AS THIS OCCURS FLOW WILL BECOME EAST TO SOUTHEAST WITH A WEAK DISTURBANCE PROGGED TO MOVE ACROSS NORTHERN CHIHUAHUA MEXICO AND ACROSS THE ARIZONA/SONORAN BORDER THIS AFTERNOON THROUGH LATE MONDAY AS IT MOVES TOWARD THE LOWER COLORADO RIVER BASIN. MODELS ARE ADVERTISING THE PW`S TO INCREASE TO AROUND 1.4-1.6 INCHES TODAY FOR TUCSON WITH LESSER VALUES EAST. BY MONDAY VALUES EXPECTED TO RANGE FROM 1.2-1.4 INCHES EAST...1.5-1.6 INCHES CENTRAL AREAS AND 1.8-2.0 INCHES FOR THE FAR WEST (AJO/ORGAN PIPE). WITH THE COMBO OF AMPLE MOISTURE AND THE AFOREMENTIONED TRIGGERING MECHANISM OF THE WEAK VORT MAX TRAVERSING SOUTHERN ARIZONA...EXPECT SCATTERED TO LOCALLY NUMEROUS SHOWERS AND THUNDERSTORMS TODAY THROUGH MONDAY...WITH THE BEST THREAT OCCURRING LATE THIS AFTERNOON AND THIS EVENING...BUT STILL A DECENT THREAT AGAIN MONDAY AFTERNOON/EVENING. BY TUESDAY RAIN CHANCES IN THE LOW END SCATTERED CATEGORY NEARLY AREA WIDE AS THE WEAK DISTURBANCE MOVES UP THE COLORADO RIVER VALLEY AS THE HIGH SHIFTS TO A POSITION OVER EASTERN COLORADO. SO... WITHOUT THAT ENHANCEMENT STILL STORMS AROUND...BUT NOT AS NUMEROUS AS WHAT IS EXPECTED FOR TODAY AND MONDAY. BY WEDNESDAY THE HIGH IS EXPECTED TO MOVE TO NEW MEXICO/WEST TEXAS WITH PW`S EXPECTED TO BE DOWN FROM PREVIOUS DAYS...GENERALLY IN THE 1.1 TO 1.4 INCH RANGE FOR EAST AND CENTRAL LOCATIONS. FOR THURSDAY AND CONTINUING THROUGH SATURDAY...THE HIGH IS EXPECTED TO SHIFT TO A POSITION NEARLY OVERHEAD OR JUST TO OUR SOUTH...GIVING US A DRIER SOUTHWESTERLY FLOW ALOFT...WITH PW`S DROPPING TO AROUND THE 1 INCH MARK BY SATURDAY. THAT SAID...I TWEAKED THE POP FORECAST FOR LATE IN THE PERIOD TO GIVE US MAINLY ISOLATED TO LOW END SCATTERED ACTIVITY MAINLY NEAR THE NEW MEXICO BORDER FOR FRIDAY AND SATURDAY. FOR TUCSON...HIGH TEMPS WILL GENERALLY BE NEAR NORMAL TODAY AND MONDAY...THEN 1 TO 3 DEGS ABOVE NORMAL TUESDAY AND WEDNESDAY...THEN 5 TO 7 DEGS ABOVE NORMAL THURSDAY THROUGH SATURDAY. LOWS WILL RANGE FROM 3 TO 6 DEGS ABOVE NORMAL...BUT THE WARMEST MORNINGS WILL LIKELY OCCUR LATE NEXT WEEK AND WEEKEND. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...MEYER AVIATION/FIRE WEATHER...CERNIGLIA PREVIOUS DISCUSSION...MOLLERE VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION...CORRECTED
NWS PHOENIX AZ
455 AM MST SUN AUG 23 2015 .SYNOPSIS... HIGH PRESSURE WILL BECOME REESTABLISHED TO OUR EAST...RESULTING IN HIGHER THAN NORMAL RAIN CHANCES ACROSS THE LOWER DESERTS THROUGH TUESDAY. DRIER CONDITIONS WILL RETURN BY MIDWEEK ALONG WITH ABOVE NORMAL TEMPERATURES. WELL ABOVE NORMAL TEMPERATURES ARE POSSIBLE BY NEXT WEEKEND. && .DISCUSSION... LATEST RAP STREAMLINE ANALYSIS SHOWS THE SUBTROPICAL RIDGE WEAKENING ACROSS THE BAJA PENINSULA AND MIGRATING EASTWARD...RESULTING IN A CESSATION OF THE PERSISTENT WESTERLY FLOW. A VERY WEAK STEERING FLOW WILL DEVELOP TODAY FOLLOWED BY A REVERSAL IN THE WINDS TO LIGHT EASTERLY BY TONIGHT. MEANWHILE...A VORT MAX ASSOCIATED WITH AN INVERTED TROUGH IS EVIDENT NEAR THE BOOTHEEL OF NM. THIS SETUP IS FAVORABLE FOR THUNDERSTORM ACTIVITY ACROSS EASTERN AND SOUTHEASTERN AZ TODAY WITH PROPAGATION TO THE WEST INTO SOUTH-CENTRAL AZ THIS EVENING. CONVECTIVELY PARAMETERIZED MODELS SUCH AS THE GFS...ECMWF AND NMM-B SUGGEST SOME POTENTIAL FOR THUNDERSTORMS ACROSS THE LOWER DESERTS INCLUDING THE PHOENIX AREA. HOWEVER...CONSENSUS AMONG THE CONVECTIVE ALLOWING WRFS IS THAT CONVERGING OUTFLOW BOUNDARIES WILL PRODUCE ONLY ISOLATED CONVECTION ACROSS THE PHOENIX AREA...BUT WITH PERHAPS HIGHER PROBABILITIES ACROSS THE SOUTHWEST DESERTS. MOST LIKELY IMPACT TONIGHT IS BLOWING DUST...THOUGH THE POTENTIAL CERTAINLY EXISTS FOR THUNDERSTORMS CONTAINING STRONG WINDS AND DOWNBURSTS...PARTICULARLY ACROSS PORTIONS OF MARICOPA AND PINAL COUNTIES. WITH THE INVERTED TROUGH DRAPED ACROSS THE LOWER DESERTS OVERNIGHT...CONVECTION ALSO CANNOT BE RULED OUT THROUGH MONDAY MORNING. BEST CHANCE FOR PRECIPITATION APPEARS TO BE MONDAY AS THE MONSOON HIGH DRIFTS TOWARDS THE FOUR CORNERS RESULTING IN A MOIST SOUTHEASTERLY FLOW. MODELS ALSO INDICATE THAT THE 250 MB HIGH DISPLACED TO THE SOUTH WILL PRODUCE A DIFLUENT AND DIVERGENT PATTERN IN THE UPPER LEVELS...HELPING TO PROVIDE ASCENT WHICH MAY OFFSET ANY LACK OF INSTABILITY DUE TO THE WIDESPREAD CLOUDINESS. THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL PERSIST TUESDAY BUT WILL SHIFT SOMEWHAT TO THE WEST. LATEST MODELS SUGGEST THAT SEVERAL TRAILING VORT MAXES AND MCVS WILL PROVIDE ASCENT IN A RELATIVELY STRONG AND MOIST SOUTHERLY FLOW. THE FOCUS FOR PRECIPITATION WILL SHIFT NORTHWARD WEDNESDAY AS THE AFOREMENTIONED TROUGH ACCELERATES NORTHEASTWARD AROUND THE ANTICYCLONE IN NM. GFS/ECMWF ARE IN GOOD AGREEMENT THAT THE RIDGE WILL AGAIN MIGRATE TO OUR SOUTH LATE IN THE WEEK...RESULTING IN A SOUTHWESTERLY FLOW AND A RETURN TO WARMER AND DRIER CONDITIONS. ABOVE NORMAL TEMPERATURES ARE LIKELY BEGINNING THURSDAY WITH HIGHS IN THE PHOENIX AREA POTENTIALLY REACHING 110 DEGREES AGAIN BY NEXT SATURDAY...AND EVEN WARMER ACROSS SOUTHEASTERN CA. THIS COULD BE THE WARMEST AUGUST ON RECORD FOR BOTH PHOENIX AND YUMA AND THE PERIOD OF ABOVE NORMAL TEMPERATURES TO END THE MONTH MAY HELP CLINCH THE TOP SPOT FOR BOTH LOCATIONS. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... MOSTLY CLEAR SKIES AND TYPICAL AM EASTERLY WINDS TO PERSIST THRU MIDDAY. WINDS TO GRADUALLY SWING AROUND TO W-SW PSBLY AN HOUR OR TWO EARLIER THAN THEIR USUAL EARLY AFTN WINDOW...PSBLY AS EARLY AS 23/18Z. TODAY BEGINS A SEVERAL-DAY RETURN PERIOD OF MORE FAVORABLE MONSOON STORM CHANCES ACROSS THE LOWER DESERTS AND SURVIVING INTO CORNERS OF THE PHX METRO TO START. HI-RES MODEL GUIDANCE AND EARLY AM CCFP INDICATE STORMS TO DEVELOP FIRST ALONG THE MOGOLLON RIM BY MIDDAY AND AN HOUR OR TWO LATER ACROSS SE AZ. INITIAL BEST GUESS AT TIMING THE FIRST...IN A POTENTIAL FEW...OUTFLOW INTRUSION...COULD BE BETWEEN THE 24/00-02Z WINDOW FROM EAST- NORTHEAST. ADDITIONAL OUTFLOW PUSH FROM THE SOUTH COULD EXPAND INTO THE PHX METRO POST 02Z...ALONG WITH ISO. POP-UP SHOWER AND STORM ACTIVITY WITH ITS PASSAGE. GNLY OPENED WITH VCSH AROUND 24/02-03Z TIMEFRAME FOR THE TERMINALS. VSBY REDUCTION IS PSBL EITHER IN SUSPENDED/LOFTED DUST OR A MORE CONSOLIDATED OUTFLOW AND THICKER DUST...BUT HELD OFF FROM INCLUDING VSBY REDUCTION IN THE 12Z TAF PACKAGE ATTM. DEPENDING ON WHERE THE OUTFLOW ORIGINATES WILL HAVE BEARING ON WHAT AMOUNT...IF ANY...DUST IT MANAGES TO PICK UP. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... MOSTLY CLEAR SKIES AND PERSISTENT SOUTH TO SOUTHEASTERLY WINDS FORECAST FOR THE WESTERN TERMINALS TODAY AND THIS EVENING. STORM ACTIVITY SHOULD STAY WILL TO THE EAST ACROSS AZ THIS AFTN/EVENING...WITH SOME PSBL HIGH LEVEL DEBRIS CLOUD IN LATER INTO THE OVERNIGHT FOR KBLH. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST TUESDAY AND WEDNESDAY AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE IN FROM THE SOUTHEAST. THESE DISTURBANCES WILL SUPPORT ELEVATED CHANCES FOR MORE WIDESPREAD AND SUBSTANTIAL STORM DEVELOPMENT REGION-WIDE...WITH STORM CHANCES REACHING BEYOND THE CO RIVER VALLEY. MIN RH VALUES WILL GENERALLY RANGE BETWEEN 20 TO 30 PERCENT WITH GOOD OVERNIGHT RECOVERY. OUTSIDE OF THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS WILL BEGIN TO FOLLOW TYPICAL DIURNAL/DRAINAGE DRIVEN TRENDS. A DRAW DOWN OF MONSOON MOISTURE IS STILL FORECAST TOWARDS THE END OF THE WEEK...BUT MAY OCCUR AT A SLOWER RATE THAN ORIGINALLY THOUGHT. THE UPPER RIDGE WILL GRADUALLY POSITION ITSELF TO DRAW IN DRIER WESTERLY FLOW ALOFT...RELEGATING STORM CHANCES BACK ACROSS THE EASTERN AZ AND THE HIGHER TERRAIN. AS THE AIRMASS SLOWLY DRIES OUT...DAYTIME TEMPERATURES WILL RISE TO ABOVE NORMAL VALUES AND IN SOME OF THE SOUTHEAST CA FIRE ZONES PUSH THE 110F MARK BY THE WEEKEND. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH AVIATION...NOLTE FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
313 AM MST SUN AUG 23 2015 .SYNOPSIS... HIGH PRESSURE WILL BECOME REESTABLISHED TO OUR EAST...RESULTING IN HIGHER THAN NORMAL RAIN CHANCES ACROSS THE LOWER DESERTS THROUGH TUESDAY. DRIER CONDITIONS WILL RETURN BY MIDWEEK ALONG WITH ABOVE NORMAL TEMPERATURES. WELL ABOVE NORMAL TEMPERATURES ARE POSSIBLE BY NEXT WEEKEND. && .DISCUSSION... LATEST RAP STREAMLINE ANALYSIS SHOWS THE SUBTROPICAL RIDGE WEAKENING ACROSS THE BAJA PENINSULA AND MIGRATING EASTWARD...RESULTING IN A CESSATION OF THE PERSISTENT WESTERLY FLOW. A VERY WEAK STEERING FLOW WILL DEVELOP TODAY FALLOWED BY A REVERSAL IN THE WINDS TO LIGHT EASTERLY BY TONIGHT. MEANWHILE...A VORT MAX ASSOCIATED WITH AN INVERTED TROUGH IS EVIDENT NEAR THE BOOTHEEL OF NM. THIS SETUP IS FAVORABLE FOR THUNDERSTORM ACTIVITY ACROSS EASTERN AND SOUTHEASTERN AZ TODAY WITH PROPAGATION TO THE WEST INTO SOUTH-CENTRAL AZ THIS EVENING. CONVECTIVELY PARAMETERIZED MODELS SUCH AS THE GFS...ECMWF AND NMM-B SUGGEST SOME POTENTIAL FOR THUNDERSTORMS ACROSS THE LOWER DESERTS INCLUDING THE PHOENIX AREA. HOWEVER...CONSENSUS AMONG THE CONVECTIVE ALLOWING WRFS IS THAT CONVERGING OUTFLOW BOUNDARIES WILL PRODUCE ONLY ISOLATED CONVECTION ACROSS THE PHOENIX AREA...BUT WITH PERHAPS HIGHER PROBABILITIES ACROSS THE SOUTHWEST DESERTS. MOST LIKELY IMPACT TONIGHT IS BLOWING DUST...THOUGH THE POTENTIAL CERTAINLY EXISTS FOR THUNDERSTORMS CONTAINING STRONG WINDS AND DOWNBURSTS...PARTICULARLY ACROSS PORTIONS OF MARICOPA AND PINAL COUNTIES. WITH THE INVERTED TROUGH DRAPED ACROSS THE LOWER DESERTS OVERNIGHT...CONVECTION ALSO CANNOT BE RULED OUT THROUGH MONDAY MORNING. BEST CHANCE FOR PRECIPITATION APPEARS TO BE MONDAY AS THE MONSOON HIGH DRIFTS TOWARDS THE FOUR CORNERS RESULTING IN A MOIST SOUTHEASTERLY FLOW. MODELS ALSO INDICATE THAT THE 250 MB HIGH DISPLACED TO THE SOUTH WILL PRODUCE A DIFLUENT AND DIVERGENT PATTERN IN THE UPPER LEVELS...HELPING TO PROVIDE ASCENT WHICH MAY OFFSET ANY LACK OF INSTABILITY DUE TO THE WIDESPREAD CLOUDINESS. THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL PERSIST TUESDAY BUT WILL SHIFT SOMEWHAT TO THE WEST. LATEST MODELS SUGGEST THAT SEVERAL TRAILING VORT MAXES AND MCVS WILL PROVIDE ASCENT IN A RELATIVELY STRONG AND MOIST SOUTHERLY FLOW. THE FOCUS FOR PRECIPITATION WILL SHIFT NORTHWARD WEDNESDAY AS THE AFOREMENTIONED TROUGH ACCELERATES NORTHEASTWARD AROUND THE ANTICYCLONE IN NM. GFS/ECMWF ARE IN GOOD AGREEMENT THAT THE RIDGE WILL AGAIN MIGRATE TO OUR SOUTH LATE IN THE WEEK...RESULTING IN A SOUTHWESTERLY FLOW AND A RETURN TO WARMER AND DRIER CONDITIONS. ABOVE NORMAL TEMPERATURES ARE LIKELY BEGINNING THURSDAY WITH HIGHS IN THE PHOENIX AREA POTENTIALLY REACHING 110 DEGREES AGAIN BY NEXT SATURDAY...AND EVEN WARMER ACROSS SOUTHEASTERN CA. THIS COULD BE THE WARMEST AUGUST ON RECORD FOR BOTH PHOENIX AND YUMA AND THE PERIOD OF ABOVE NORMAL TEMPERATURES TO END THE MONTH MAY HELP CLINCH THE TOP SPOT FOR BOTH LOCATIONS. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... ONCE AGAIN CONVECTION LOOKS TO BE FOCUSED WELL TO THE EAST/SOUTHEAST OF THE GREATER PHOENIX AREA THIS EVENING...AS PERSISTENT WESTERLY STEERING FLOW WILL HINDER THE PROGRESS OF ANY STORM THAT TRIES TO DEVELOP OR MOVE WESTWARD AND THREATEN THE CENTRAL DESERTS AND THE PHOENIX AREA. MOISTURE IS DOWN SLIGHTLY WITH SURFACE DEWPOINTS MOSTLY IN THE 50S AND WE HAVE SEEN LESS CUMULUS IN THE AREA AS COMPARED TO 24 HOURS AGO. NO MENTION OF THUNDER WILL BE IN THE AREA TAFS TONIGHT...JUST FEW TO SCT HIGH BASED CU AND A BIT OF CIRRUS DEBRIS CLOUDS LATER IN THE EVENING AND OVERNIGHT. SOME HI-RES MODEL GUIDANCE SUGGESTED OUTFLOW WINDS MAY MOVE INTO THE PHOENIX AREA AFTER 7 PM...BUT GIVEN HOW FAR AWAY FROM PHOENIX THE STORMS CURRENTLY ARE...CONFIDENCE IN THIS IS LOW. HAVE REMOVED THE TEMPO GROUP FOR A SOUTHEAST WIND SHIFT THIS EVENING AT KPHX BUT LEFT IT IN FOR KIWA. CANNOT RULE OUT A WIND SHIFT TO THE SOUTHEAST LATER THIS EVENING BUT ODDS ARE SOMEWHAT LOW THAT IT WILL OCCUR. OTHERWISE WINDS SHOULD STAY GENERALLY WEST TIL LATE IN THE EVENING ESPECIALLY AT KPHX. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... PERSISTENCE WIND AND CIG FORECAST FOR THE WESTERN TERMINALS WITH BREEZY SOUTHERLY WINDS FOR KBLH...SOUTHEASTERLY WINDS FOR KIPL AND SKC FOR THE 00Z TAF PERIOD. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... MONDAY THROUGH FRIDAY... MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST THROUGH MIDWEEK. STORM CHANCES WILL CONTINUE FOR THE HIGHER TERRAIN LOCALES FOR SUNDAY BEFORE EXPANDING INTO THE LOWER DESERT ELEVATIONS BY THE EARLY WORK WEEK AS SOME UPPER LEVEL DISTURBANCES PASS THROUGH THE AREA AND SUPPORT THE POTENTIAL FOR MORE WIDESPREAD STORM DEVELOPMENT. DAYTIME HUMIDITIES WILL RANGE FROM THE 20 TO 30 PERCENT RANGE WHILE MAKING GOOD OVERNIGHT RECOVERIES. OUTSIDE OF THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS TO MAINTAIN DAYTIME HEADINGS 10 TO 20 MPH WHILE BECOMING DOWN DRAINAGE/DOWN VALLEY IN THE OVERNIGHTS. A DRAW DOWN OF MONSOON MOISTURE AND INTRUSION OF WESTERLY FLOW ALOFT WILL RELEGATE STORM CHANCES BACK ACROSS EASTERN AZ FOR THE LATTER PART OF THE WEEK...WHILE TEMPERATURES ALSO BEGIN TO WARM TO ABOVE NORMAL VALUES. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH AVIATION...CB FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1149 AM MDT SUN AUG 23 2015 .UPDATE... ISSUED AT 1149 AM MDT SUN AUG 23 2015 UPDATED TO EXTENT COVERAGE OF SHRA/TSRA ACROSS BACA COUNTY. UPDATE ISSUED AT 945 AM MDT SUN AUG 23 2015 UPDATED TO ADD AREAS OF SMOKE AND HAZE FOR TODAY TO AREAS ALONG THE LOWER EASTERN SLOPES...WEST OF THE I-25 CORRIDOR...WITH LOW LEVEL UPSLOPE FLOW AND MID LEVEL INVERSIONS LIKELY KEEPING PAC NORTHWEST SMOKE...BROUGHT IN BY LAST NIGHTS COLD FRONT...IN PLACE. UPDATE ISSUED AT 743 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER AND POPS TO REFLECT CURRENT SATELLITE AND RADAR. LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. UPDATE ISSUED AT 647 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER PER SATELLITE AND LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 534 AM MDT SUN AUG 23 2015 ...THUNDERSTORMS MAINLY MOUNTAINS TODAY... COLD FRONT HAS PUSHED A MASS OF RELATIVELY COOL STABLE AIR SOUTH ACROSS THE PLAINS...WITH WIDESPREAD MID LEVEL CLOUDS ACROSS THE EASTERN MOUNTAINS AND PLAINS BUT NO PRECIPITATION. THE MOUNTAINS AND HIGH VALLEYS TO THE WEST REMAIN CLEAR TO PARTLY CLOUDY...WITH SOME MOSTLY CLOUDY SKIES OVER THE EASTERN SAN JUANS. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW THE ONLY REAL PROSPECTS FOR THUNDERSTORMS TO BE OVER THE MOUNTAINS AND HIGH VALLEYS. THE PLAINS SOUNDINGS SHOW A STRONG CAP. OF NOTE...HOWEVER...ARE RUNS OF THE EXPERIMENTAL HRRR AND...TO A LESSER EXTENT...THE 4KM NSSL WRF...THAT SHOW SOME CONVECTION MOVING OFF THE MOUNTAINS AND ACROSS THE I-25 CORRIDOR...MAINLY BETWEEN 4 PM AND 8 PM. NOT SURE IF THIS WILL HAPPEN GIVEN THE STRONG CAP INDICATED IN THE FORECAST SOUNDINGS BUT SOMETHING TO KEEP AN EYE ON. PROBABLY WHAT THESE MODELS ARE DOING IS DEVELOPING ELEVATED CONVECTION...AND TRACKING IT SOUTHEAST ACROSS THE PLAINS...ABOVE THE STABLE AIR. USUALLY WHEN THIS HAPPENS...HOWEVER...ANY ELEVATED CONVECTION DIES OUT ONCE IT MOVES OVER THE STABLE AIR. SO...SUSPECT THIS IS WHAT WILL HAPPEN. PRIMARY THREATS FROM STORMS OVER THE MOUNTAINS AND HIGH VALLEYS TODAY WILL BE LIGHTNING AND WIND GUSTS TO AROUND 40 MPH. THERE COULD ALSO BE SOME SPOTTY HEAVY RAIN OUT THERE. TEMPERATURES BEHIND THE COLD FRONT WILL BE ABOUT 15-20 DEGREES COOLER OVER THE EAST TODAY WITH COMFORTABLE HIGHS RANGING FROM THE MID 70S TO MID 80S. FOR THE MOUNTAINS AND HIGH VALLEYS...NOT QUITE AS MUCH COOLING...RANGING FROM JUST A COUPLE DEGREES COOLER IN SOME AREAS UP TO ABOUT 10 DEGREES COOLER IN OTHERS. HIGH VALLEY TEMPERATURES SHOULD RANGE FORM THE 70S TO LOWER 80S WITH MOUNTAIN READINGS MOSTLY IN THE 60S AND 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 534 AM MDT SUN AUG 23 2015 .MONDAY AND TUESDAY...UPPER RIDGE REMAINS OVERHEAD WITH A MODEST AMOUNT OF MID LEVEL MOISTURE OVER THE REGION. BEST CHANCES FOR DIURNAL CONVECTION WILL BE OVER AND NEAR THE MOUNTAINS. WITH WEAK WINDS ALOFT...ANTICIPATE CONVECTION WILL HAVE DIFFICULTY MOVING OFF OF THE HIGHER TERRAIN. NAM CONTINUES TO SHOW SOME INCREASED CAPE NEAR THE KANSAS BORDER DURING THE AFTERNOON AND EVENING. GIVEN THE LACK OF A SHORTWAVE...MAINTAINED SILENT POPS OVER THE PLAINS. WARM WEATHER CONTINUES WITH HIGHS ABOVE AVERAGE ON BOTH DAYS. .WEDNESDAY AND THURSDAY...AN UPPER TROUGH WILL APPROACH THE WEST COAST INCREASING THE INFLUX OF MONSOON MOISTURE INTO THE REGION. LATEST SIMULATIONS HAVE WEDNESDAY BEING THE WETTEST DAY OVER AND NEAR THE MOUNTAINS WITH GREATEST AMOUNT OF MOISTURE. GFS AND EC DEVELOP A TROUGH OVER THE REGION WHICH SLOWLY MOVES EAST ON THURSDAY. WITH THE TROUGH NEAR THE KANSAS BORDER BY THURSDAY AFTERNOON...CHANCES FOR CONVECTION WILL INCREASE NEAR THE KANSAS BORDER. HAVE CONCERNS THAT THE CONVECTIVE PARAMETERIZATION COULD BE INFLUENCING THE DEVELOPMENT OF THIS TROUGH...WHICH COULD AFFECT THE LOCATION...TIMING AND STRENGTH OF CONVECTION. .FRIDAY AND SATURDAY...MODELS HAVE DIFFERENCES IN THE SPEED OF THE NEXT TROUGH MOVING INTO THE PACIFIC NORTHWEST. GENERAL TREND WILL BE TO TURN FLOW ALOFT MORE SOUTHWESTERLY BRINGING DRIER AIR ALOFT INTO THE REGION. GRIDS GENERALLY HAVE ISOLATED TO SCATTERED CONVECTION MOSTLY CONFINED TO THE MOUNTAINS WITH TEMPERATURE NEAR OR ABOVE NORMAL. --PGW-- && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1132 AM MDT SUN AUG 23 2015 MAINLY VFR CONDITIONS EXPECTED AT COS...PUB AND ALS OVER THE NEXT 24 HOURS...ALTHOUGH THERE COULD SOME AREAS OF REDUCED VISIBILITIES ALONG AND WEST OF THE I-25 CORRIDOR THROUGH THE AFTERNOON AND EVENING...WITH BREEZY SOUTH TO SOUTHEAST WINDS AND MID LEVEL INVERSIONS KEEPING SMOKE FROM PAC NW WILDFIRES IN PLACE ALONG THE FRONT RANGE. ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING STORMS EXPECTED OVER AND NEAR THE HIGHER TERRAIN...WITH BEST CHANCES OF STORMS AFFECTING TERMAINALS AT ALS. A FEW STORMS COULD TRY A MOVE EAST ONTO THE I-25 CORRIDOR...THOUGH ATMOSPHERE BEHIND LAST NIGHTS COLD FRONT LOOKS BE TOO STABLE TO SUSTAIN STORMS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...LW LONG TERM...PGW AVIATION...MW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1133 AM MDT SUN AUG 23 2015 .UPDATE... ISSUED AT 945 AM MDT SUN AUG 23 2015 UPDATED TO ADD AREAS OF SMOKE AND HAZE FOR TODAY TO AREAS ALONG THE LOWER EASTERN SLOPES...WEST OF THE I-25 CORRIDOR...WITH LOW LEVEL UPSLOPE FLOW AND MID LEVEL INVERSIONS LIKELY KEEPING PAC NORTHWEST SMOKE...BROUGHT IN BY LAST NIGHTS COLD FRONT...IN PLACE. UPDATE ISSUED AT 743 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER AND POPS TO REFLECT CURRENT SATELLITE AND RADAR. LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. UPDATE ISSUED AT 647 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER PER SATELLITE AND LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 534 AM MDT SUN AUG 23 2015 ...THUNDERSTORMS MAINLY MOUNTAINS TODAY... COLD FRONT HAS PUSHED A MASS OF RELATIVELY COOL STABLE AIR SOUTH ACROSS THE PLAINS...WITH WIDESPREAD MID LEVEL CLOUDS ACROSS THE EASTERN MOUNTAINS AND PLAINS BUT NO PRECIPITATION. THE MOUNTAINS AND HIGH VALLEYS TO THE WEST REMAIN CLEAR TO PARTLY CLOUDY...WITH SOME MOSTLY CLOUDY SKIES OVER THE EASTERN SAN JUANS. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW THE ONLY REAL PROSPECTS FOR THUNDERSTORMS TO BE OVER THE MOUNTAINS AND HIGH VALLEYS. THE PLAINS SOUNDINGS SHOW A STRONG CAP. OF NOTE...HOWEVER...ARE RUNS OF THE EXPERIMENTAL HRRR AND...TO A LESSER EXTENT...THE 4KM NSSL WRF...THAT SHOW SOME CONVECTION MOVING OFF THE MOUNTAINS AND ACROSS THE I-25 CORRIDOR...MAINLY BETWEEN 4 PM AND 8 PM. NOT SURE IF THIS WILL HAPPEN GIVEN THE STRONG CAP INDICATED IN THE FORECAST SOUNDINGS BUT SOMETHING TO KEEP AN EYE ON. PROBABLY WHAT THESE MODELS ARE DOING IS DEVELOPING ELEVATED CONVECTION...AND TRACKING IT SOUTHEAST ACROSS THE PLAINS...ABOVE THE STABLE AIR. USUALLY WHEN THIS HAPPENS...HOWEVER...ANY ELEVATED CONVECTION DIES OUT ONCE IT MOVES OVER THE STABLE AIR. SO...SUSPECT THIS IS WHAT WILL HAPPEN. PRIMARY THREATS FROM STORMS OVER THE MOUNTAINS AND HIGH VALLEYS TODAY WILL BE LIGHTNING AND WIND GUSTS TO AROUND 40 MPH. THERE COULD ALSO BE SOME SPOTTY HEAVY RAIN OUT THERE. TEMPERATURES BEHIND THE COLD FRONT WILL BE ABOUT 15-20 DEGREES COOLER OVER THE EAST TODAY WITH COMFORTABLE HIGHS RANGING FROM THE MID 70S TO MID 80S. FOR THE MOUNTAINS AND HIGH VALLEYS...NOT QUITE AS MUCH COOLING...RANGING FROM JUST A COUPLE DEGREES COOLER IN SOME AREAS UP TO ABOUT 10 DEGREES COOLER IN OTHERS. HIGH VALLEY TEMPERATURES SHOULD RANGE FORM THE 70S TO LOWER 80S WITH MOUNTAIN READINGS MOSTLY IN THE 60S AND 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 534 AM MDT SUN AUG 23 2015 .MONDAY AND TUESDAY...UPPER RIDGE REMAINS OVERHEAD WITH A MODEST AMOUNT OF MID LEVEL MOISTURE OVER THE REGION. BEST CHANCES FOR DIURNAL CONVECTION WILL BE OVER AND NEAR THE MOUNTAINS. WITH WEAK WINDS ALOFT...ANTICIPATE CONVECTION WILL HAVE DIFFICULTY MOVING OFF OF THE HIGHER TERRAIN. NAM CONTINUES TO SHOW SOME INCREASED CAPE NEAR THE KANSAS BORDER DURING THE AFTERNOON AND EVENING. GIVEN THE LACK OF A SHORTWAVE...MAINTAINED SILENT POPS OVER THE PLAINS. WARM WEATHER CONTINUES WITH HIGHS ABOVE AVERAGE ON BOTH DAYS. .WEDNESDAY AND THURSDAY...AN UPPER TROUGH WILL APPROACH THE WEST COAST INCREASING THE INFLUX OF MONSOON MOISTURE INTO THE REGION. LATEST SIMULATIONS HAVE WEDNESDAY BEING THE WETTEST DAY OVER AND NEAR THE MOUNTAINS WITH GREATEST AMOUNT OF MOISTURE. GFS AND EC DEVELOP A TROUGH OVER THE REGION WHICH SLOWLY MOVES EAST ON THURSDAY. WITH THE TROUGH NEAR THE KANSAS BORDER BY THURSDAY AFTERNOON...CHANCES FOR CONVECTION WILL INCREASE NEAR THE KANSAS BORDER. HAVE CONCERNS THAT THE CONVECTIVE PARAMETERIZATION COULD BE INFLUENCING THE DEVELOPMENT OF THIS TROUGH...WHICH COULD AFFECT THE LOCATION...TIMING AND STRENGTH OF CONVECTION. .FRIDAY AND SATURDAY...MODELS HAVE DIFFERENCES IN THE SPEED OF THE NEXT TROUGH MOVING INTO THE PACIFIC NORTHWEST. GENERAL TREND WILL BE TO TURN FLOW ALOFT MORE SOUTHWESTERLY BRINGING DRIER AIR ALOFT INTO THE REGION. GRIDS GENERALLY HAVE ISOLATED TO SCATTERED CONVECTION MOSTLY CONFINED TO THE MOUNTAINS WITH TEMPERATURE NEAR OR ABOVE NORMAL. --PGW-- && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1132 AM MDT SUN AUG 23 2015 MAINLY VFR CONDITIONS EXPECTED AT COS...PUB AND ALS OVER THE NEXT 24 HOURS...ALTHOUGH THERE COULD SOME AREAS OF REDUCED VISIBILITIES ALONG AND WEST OF THE I-25 CORRIDOR THROUGH THE AFTERNOON AND EVENING...WITH BREEZY SOUTH TO SOUTHEAST WINDS AND MID LEVEL INVERSIONS KEEPING SMOKE FROM PAC NW WILDFIRES IN PLACE ALONG THE FRONT RANGE. ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING STORMS EXPECTED OVER AND NEAR THE HIGHER TERRAIN...WITH BEST CHANCES OF STORMS AFFECTING TERMAINALS AT ALS. A FEW STORMS COULD TRY A MOVE EAST ONTO THE I-25 CORRIDOR...THOUGH ATMOSPHERE BEHIND LAST NIGHTS COLD FRONT LOOKS BE TOO STABLE TO SUSTAIN STORMS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...LW LONG TERM...PGW AVIATION...MW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
945 AM MDT SUN AUG 23 2015 .UPDATE... ISSUED AT 945 AM MDT SUN AUG 23 2015 UPDATED TO ADD AREAS OF SMOKE AND HAZE FOR TODAY TO AREAS ALONG THE LOWER EASTERN SLOPES...WEST OF THE I-25 CORRIDOR...WITH LOW LEVEL UPSLOPE FLOW AND MID LEVEL INVERSIONS LIKELY KEEPING PAC NORTHWEST SMOKE...BROUGHT IN BY LAST NIGHTS COLD FRONT...IN PLACE. UPDATE ISSUED AT 743 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER AND POPS TO REFLECT CURRENT SATELLITE AND RADAR. LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. UPDATE ISSUED AT 647 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER PER SATELLITE AND LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 534 AM MDT SUN AUG 23 2015 ...THUNDERSTORMS MAINLY MOUNTAINS TODAY... COLD FRONT HAS PUSHED A MASS OF RELATIVELY COOL STABLE AIR SOUTH ACROSS THE PLAINS...WITH WIDESPREAD MID LEVEL CLOUDS ACROSS THE EASTERN MOUNTAINS AND PLAINS BUT NO PRECIPITATION. THE MOUNTAINS AND HIGH VALLEYS TO THE WEST REMAIN CLEAR TO PARTLY CLOUDY...WITH SOME MOSTLY CLOUDY SKIES OVER THE EASTERN SAN JUANS. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW THE ONLY REAL PROSPECTS FOR THUNDERSTORMS TO BE OVER THE MOUNTAINS AND HIGH VALLEYS. THE PLAINS SOUNDINGS SHOW A STRONG CAP. OF NOTE...HOWEVER...ARE RUNS OF THE EXPERIMENTAL HRRR AND...TO A LESSER EXTENT...THE 4KM NSSL WRF...THAT SHOW SOME CONVECTION MOVING OFF THE MOUNTAINS AND ACROSS THE I-25 CORRIDOR...MAINLY BETWEEN 4 PM AND 8 PM. NOT SURE IF THIS WILL HAPPEN GIVEN THE STRONG CAP INDICATED IN THE FORECAST SOUNDINGS BUT SOMETHING TO KEEP AN EYE ON. PROBABLY WHAT THESE MODELS ARE DOING IS DEVELOPING ELEVATED CONVECTION...AND TRACKING IT SOUTHEAST ACROSS THE PLAINS...ABOVE THE STABLE AIR. USUALLY WHEN THIS HAPPENS...HOWEVER...ANY ELEVATED CONVECTION DIES OUT ONCE IT MOVES OVER THE STABLE AIR. SO...SUSPECT THIS IS WHAT WILL HAPPEN. PRIMARY THREATS FROM STORMS OVER THE MOUNTAINS AND HIGH VALLEYS TODAY WILL BE LIGHTNING AND WIND GUSTS TO AROUND 40 MPH. THERE COULD ALSO BE SOME SPOTTY HEAVY RAIN OUT THERE. TEMPERATURES BEHIND THE COLD FRONT WILL BE ABOUT 15-20 DEGREES COOLER OVER THE EAST TODAY WITH COMFORTABLE HIGHS RANGING FROM THE MID 70S TO MID 80S. FOR THE MOUNTAINS AND HIGH VALLEYS...NOT QUITE AS MUCH COOLING...RANGING FROM JUST A COUPLE DEGREES COOLER IN SOME AREAS UP TO ABOUT 10 DEGREES COOLER IN OTHERS. HIGH VALLEY TEMPERATURES SHOULD RANGE FORM THE 70S TO LOWER 80S WITH MOUNTAIN READINGS MOSTLY IN THE 60S AND 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 534 AM MDT SUN AUG 23 2015 .MONDAY AND TUESDAY...UPPER RIDGE REMAINS OVERHEAD WITH A MODEST AMOUNT OF MID LEVEL MOISTURE OVER THE REGION. BEST CHANCES FOR DIURNAL CONVECTION WILL BE OVER AND NEAR THE MOUNTAINS. WITH WEAK WINDS ALOFT...ANTICIPATE CONVECTION WILL HAVE DIFFICULTY MOVING OFF OF THE HIGHER TERRAIN. NAM CONTINUES TO SHOW SOME INCREASED CAPE NEAR THE KANSAS BORDER DURING THE AFTERNOON AND EVENING. GIVEN THE LACK OF A SHORTWAVE...MAINTAINED SILENT POPS OVER THE PLAINS. WARM WEATHER CONTINUES WITH HIGHS ABOVE AVERAGE ON BOTH DAYS. .WEDNESDAY AND THURSDAY...AN UPPER TROUGH WILL APPROACH THE WEST COAST INCREASING THE INFLUX OF MONSOON MOISTURE INTO THE REGION. LATEST SIMULATIONS HAVE WEDNESDAY BEING THE WETTEST DAY OVER AND NEAR THE MOUNTAINS WITH GREATEST AMOUNT OF MOISTURE. GFS AND EC DEVELOP A TROUGH OVER THE REGION WHICH SLOWLY MOVES EAST ON THURSDAY. WITH THE TROUGH NEAR THE KANSAS BORDER BY THURSDAY AFTERNOON...CHANCES FOR CONVECTION WILL INCREASE NEAR THE KANSAS BORDER. HAVE CONCERNS THAT THE CONVECTIVE PARAMETERIZATION COULD BE INFLUENCING THE DEVELOPMENT OF THIS TROUGH...WHICH COULD AFFECT THE LOCATION...TIMING AND STRENGTH OF CONVECTION. .FRIDAY AND SATURDAY...MODELS HAVE DIFFERENCES IN THE SPEED OF THE NEXT TROUGH MOVING INTO THE PACIFIC NORTHWEST. GENERAL TREND WILL BE TO TURN FLOW ALOFT MORE SOUTHWESTERLY BRINGING DRIER AIR ALOFT INTO THE REGION. GRIDS GENERALLY HAVE ISOLATED TO SCATTERED CONVECTION MOSTLY CONFINED TO THE MOUNTAINS WITH TEMPERATURE NEAR OR ABOVE NORMAL. --PGW-- && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 534 AM MDT SUN AUG 23 2015 COLD FRONT HAS BROUGHT WIDESPREAD MID LEVEL CLOUDS TO THE EASTERN MOUNTAINS AND PLAINS THIS MORNING. THE FRONT HAS EVEN PUSHED LOW CLOUDS UP INTO PARTS OF THE UPPER ARKANSAS RIVER VALLEY. SKIES OVER THE SAN LUIS VALLEY AND SOUTHWEST MOUNTAINS ARE GENERALLY CLEAR OR PARTLY CLOUDY...ALTHOUGH SKIES OVER THE SAN JUANS ARE MOSTLY CLOUDY. LITTLE OR NO PRECIPITATION ACROSS THE FLIGHT AREA AT THIS TIME BUT THERE ARE SOME POCKETS OF MVFR/IFR/LIFR CLOUDS OVER THE CENTRAL AND EASTERN MOUNTAINS...AND THE UPPER ARKANSAS RIVER VALLEY. OUTSIDE OF THE LOW CLOUDS...CONDITIONS ARE VFR THIS MORNING. MUCH OF THE CLOUDINESS SHOULD DISSIPATE WITHIN A FEW HOURS OF SUNRISE THIS MORNING. THEN...AFTER ABOUT 17Z...ISOLATED THUNDERSTORMS WILL START TO DEVELOP OVER THE MOUNTAINS AND HIGH VALLEYS...INCREASING IN COVERAGE THROUGH THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN PORTIONS OF THE MOUNTAINS AND SAN LUIS VALLEY. A FEW STORMS COULD DRIFT OVER THE I-25 CORRIDOR BETWEEN ROUGHLY 22Z AND 02Z...BUT THESE ARE EXPECTED TO BE ISOLATED AND WEAK DUE TO A RELATIVELY COOL...STABLE AIRMASS SITUATED OVER THE PLAINS. GENERALLY VFR ACROSS THE FLIGHT AREA TODAY AND TONIGHT...ALTHOUGH LOCAL MVFR/IFR/LIFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWER OR THUNDERSTORM ACTIVITY. FOR KCOS AND KPUB...STRATUS CLOUD BASES THIS MORNING EXPECTED TO REMAIN HIGH ENOUGH FOR VFR. NO THUNDERSTORMS IN FORECAST FOR THESE 2 SITES IN THE AFTERNOON AS THE AIRMASS SHOULD BE TOO STABLE. FOR KALS...NO STRATUS DECK THIS MORNING...BUT COULD BE SOME THUNDERSTORMS IN THE AFTERNOON. THUS...12Z ISSUANCE OF TAFS WILL INCLUDE MENTION OF VCTS AFTER 21Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...LW LONG TERM...PGW AVIATION...LW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
745 AM MDT SUN AUG 23 2015 .UPDATE... ISSUED AT 743 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER AND POPS TO REFLECT CURRENT SATELLITE AND RADAR. LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. UPDATE ISSUED AT 647 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER PER SATELLITE AND LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 534 AM MDT SUN AUG 23 2015 ...THUNDERSTORMS MAINLY MOUNTAINS TODAY... COLD FRONT HAS PUSHED A MASS OF RELATIVELY COOL STABLE AIR SOUTH ACROSS THE PLAINS...WITH WIDESPREAD MID LEVEL CLOUDS ACROSS THE EASTERN MOUNTAINS AND PLAINS BUT NO PRECIPITATION. THE MOUNTAINS AND HIGH VALLEYS TO THE WEST REMAIN CLEAR TO PARTLY CLOUDY...WITH SOME MOSTLY CLOUDY SKIES OVER THE EASTERN SAN JUANS. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW THE ONLY REAL PROSPECTS FOR THUNDERSTORMS TO BE OVER THE MOUNTAINS AND HIGH VALLEYS. THE PLAINS SOUNDINGS SHOW A STRONG CAP. OF NOTE...HOWEVER...ARE RUNS OF THE EXPERIMENTAL HRRR AND...TO A LESSER EXTENT...THE 4KM NSSL WRF...THAT SHOW SOME CONVECTION MOVING OFF THE MOUNTAINS AND ACROSS THE I-25 CORRIDOR...MAINLY BETWEEN 4 PM AND 8 PM. NOT SURE IF THIS WILL HAPPEN GIVEN THE STRONG CAP INDICATED IN THE FORECAST SOUNDINGS BUT SOMETHING TO KEEP AN EYE ON. PROBABLY WHAT THESE MODELS ARE DOING IS DEVELOPING ELEVATED CONVECTION...AND TRACKING IT SOUTHEAST ACROSS THE PLAINS...ABOVE THE STABLE AIR. USUALLY WHEN THIS HAPPENS...HOWEVER...ANY ELEVATED CONVECTION DIES OUT ONCE IT MOVES OVER THE STABLE AIR. SO...SUSPECT THIS IS WHAT WILL HAPPEN. PRIMARY THREATS FROM STORMS OVER THE MOUNTAINS AND HIGH VALLEYS TODAY WILL BE LIGHTNING AND WIND GUSTS TO AROUND 40 MPH. THERE COULD ALSO BE SOME SPOTTY HEAVY RAIN OUT THERE. TEMPERATURES BEHIND THE COLD FRONT WILL BE ABOUT 15-20 DEGREES COOLER OVER THE EAST TODAY WITH COMFORTABLE HIGHS RANGING FROM THE MID 70S TO MID 80S. FOR THE MOUNTAINS AND HIGH VALLEYS...NOT QUITE AS MUCH COOLING...RANGING FROM JUST A COUPLE DEGREES COOLER IN SOME AREAS UP TO ABOUT 10 DEGREES COOLER IN OTHERS. HIGH VALLEY TEMPERATURES SHOULD RANGE FORM THE 70S TO LOWER 80S WITH MOUNTAIN READINGS MOSTLY IN THE 60S AND 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 534 AM MDT SUN AUG 23 2015 .MONDAY AND TUESDAY...UPPER RIDGE REMAINS OVERHEAD WITH A MODEST AMOUNT OF MID LEVEL MOISTURE OVER THE REGION. BEST CHANCES FOR DIURNAL CONVECTION WILL BE OVER AND NEAR THE MOUNTAINS. WITH WEAK WINDS ALOFT...ANTICIPATE CONVECTION WILL HAVE DIFFICULTY MOVING OFF OF THE HIGHER TERRAIN. NAM CONTINUES TO SHOW SOME INCREASED CAPE NEAR THE KANSAS BORDER DURING THE AFTERNOON AND EVENING. GIVEN THE LACK OF A SHORTWAVE...MAINTAINED SILENT POPS OVER THE PLAINS. WARM WEATHER CONTINUES WITH HIGHS ABOVE AVERAGE ON BOTH DAYS. .WEDNESDAY AND THURSDAY...AN UPPER TROUGH WILL APPROACH THE WEST COAST INCREASING THE INFLUX OF MONSOON MOISTURE INTO THE REGION. LATEST SIMULATIONS HAVE WEDNESDAY BEING THE WETTEST DAY OVER AND NEAR THE MOUNTAINS WITH GREATEST AMOUNT OF MOISTURE. GFS AND EC DEVELOP A TROUGH OVER THE REGION WHICH SLOWLY MOVES EAST ON THURSDAY. WITH THE TROUGH NEAR THE KANSAS BORDER BY THURSDAY AFTERNOON...CHANCES FOR CONVECTION WILL INCREASE NEAR THE KANSAS BORDER. HAVE CONCERNS THAT THE CONVECTIVE PARAMETERIZATION COULD BE INFLUENCING THE DEVELOPMENT OF THIS TROUGH...WHICH COULD AFFECT THE LOCATION...TIMING AND STRENGTH OF CONVECTION. .FRIDAY AND SATURDAY...MODELS HAVE DIFFERENCES IN THE SPEED OF THE NEXT TROUGH MOVING INTO THE PACIFIC NORTHWEST. GENERAL TREND WILL BE TO TURN FLOW ALOFT MORE SOUTHWESTERLY BRINGING DRIER AIR ALOFT INTO THE REGION. GRIDS GENERALLY HAVE ISOLATED TO SCATTERED CONVECTION MOSTLY CONFINED TO THE MOUNTAINS WITH TEMPERATURE NEAR OR ABOVE NORMAL. --PGW-- && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 534 AM MDT SUN AUG 23 2015 COLD FRONT HAS BROUGHT WIDESPREAD MID LEVEL CLOUDS TO THE EASTERN MOUNTAINS AND PLAINS THIS MORNING. THE FRONT HAS EVEN PUSHED LOW CLOUDS UP INTO PARTS OF THE UPPER ARKANSAS RIVER VALLEY. SKIES OVER THE SAN LUIS VALLEY AND SOUTHWEST MOUNTAINS ARE GENERALLY CLEAR OR PARTLY CLOUDY...ALTHOUGH SKIES OVER THE SAN JUANS ARE MOSTLY CLOUDY. LITTLE OR NO PRECIPITATION ACROSS THE FLIGHT AREA AT THIS TIME BUT THERE ARE SOME POCKETS OF MVFR/IFR/LIFR CLOUDS OVER THE CENTRAL AND EASTERN MOUNTAINS...AND THE UPPER ARKANSAS RIVER VALLEY. OUTSIDE OF THE LOW CLOUDS...CONDITIONS ARE VFR THIS MORNING. MUCH OF THE CLOUDINESS SHOULD DISSIPATE WITHIN A FEW HOURS OF SUNRISE THIS MORNING. THEN...AFTER ABOUT 17Z...ISOLATED THUNDERSTORMS WILL START TO DEVELOP OVER THE MOUNTAINS AND HIGH VALLEYS...INCREASING IN COVERAGE THROUGH THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN PORTIONS OF THE MOUNTAINS AND SAN LUIS VALLEY. A FEW STORMS COULD DRIFT OVER THE I-25 CORRIDOR BETWEEN ROUGHLY 22Z AND 02Z...BUT THESE ARE EXPECTED TO BE ISOLATED AND WEAK DUE TO A RELATIVELY COOL...STABLE AIRMASS SITUATED OVER THE PLAINS. GENERALLY VFR ACROSS THE FLIGHT AREA TODAY AND TONIGHT...ALTHOUGH LOCAL MVFR/IFR/LIFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWER OR THUNDERSTORM ACTIVITY. FOR KCOS AND KPUB...STRATUS CLOUD BASES THIS MORNING EXPECTED TO REMAIN HIGH ENOUGH FOR VFR. NO THUNDERSTORMS IN FORECAST FOR THESE 2 SITES IN THE AFTERNOON AS THE AIRMASS SHOULD BE TOO STABLE. FOR KALS...NO STRATUS DECK THIS MORNING...BUT COULD BE SOME THUNDERSTORMS IN THE AFTERNOON. THUS...12Z ISSUANCE OF TAFS WILL INCLUDE MENTION OF VCTS AFTER 21Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...LW SHORT TERM...LW LONG TERM...PGW AVIATION...LW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
650 AM MDT SUN AUG 23 2015 .UPDATE... ISSUED AT 647 AM MDT SUN AUG 23 2015 ADJUSTED SHORT TERM SKY COVER PER SATELLITE AND LOADED LATEST OBSERVATIONS INTO FRONT END OF FORECAST GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 534 AM MDT SUN AUG 23 2015 ...THUNDERSTORMS MAINLY MOUNTAINS TODAY... COLD FRONT HAS PUSHED A MASS OF RELATIVELY COOL STABLE AIR SOUTH ACROSS THE PLAINS...WITH WIDESPREAD MID LEVEL CLOUDS ACROSS THE EASTERN MOUNTAINS AND PLAINS BUT NO PRECIPITATION. THE MOUNTAINS AND HIGH VALLEYS TO THE WEST REMAIN CLEAR TO PARTLY CLOUDY...WITH SOME MOSTLY CLOUDY SKIES OVER THE EASTERN SAN JUANS. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW THE ONLY REAL PROSPECTS FOR THUNDERSTORMS TO BE OVER THE MOUNTAINS AND HIGH VALLEYS. THE PLAINS SOUNDINGS SHOW A STRONG CAP. OF NOTE...HOWEVER...ARE RUNS OF THE EXPERIMENTAL HRRR AND...TO A LESSER EXTENT...THE 4KM NSSL WRF...THAT SHOW SOME CONVECTION MOVING OFF THE MOUNTAINS AND ACROSS THE I-25 CORRIDOR...MAINLY BETWEEN 4 PM AND 8 PM. NOT SURE IF THIS WILL HAPPEN GIVEN THE STRONG CAP INDICATED IN THE FORECAST SOUNDINGS BUT SOMETHING TO KEEP AN EYE ON. PROBABLY WHAT THESE MODELS ARE DOING IS DEVELOPING ELEVATED CONVECTION...AND TRACKING IT SOUTHEAST ACROSS THE PLAINS...ABOVE THE STABLE AIR. USUALLY WHEN THIS HAPPENS...HOWEVER...ANY ELEVATED CONVECTION DIES OUT ONCE IT MOVES OVER THE STABLE AIR. SO...SUSPECT THIS IS WHAT WILL HAPPEN. PRIMARY THREATS FROM STORMS OVER THE MOUNTAINS AND HIGH VALLEYS TODAY WILL BE LIGHTNING AND WIND GUSTS TO AROUND 40 MPH. THERE COULD ALSO BE SOME SPOTTY HEAVY RAIN OUT THERE. TEMPERATURES BEHIND THE COLD FRONT WILL BE ABOUT 15-20 DEGREES COOLER OVER THE EAST TODAY WITH COMFORTABLE HIGHS RANGING FROM THE MID 70S TO MID 80S. FOR THE MOUNTAINS AND HIGH VALLEYS...NOT QUITE AS MUCH COOLING...RANGING FROM JUST A COUPLE DEGREES COOLER IN SOME AREAS UP TO ABOUT 10 DEGREES COOLER IN OTHERS. HIGH VALLEY TEMPERATURES SHOULD RANGE FORM THE 70S TO LOWER 80S WITH MOUNTAIN READINGS MOSTLY IN THE 60S AND 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 534 AM MDT SUN AUG 23 2015 .MONDAY AND TUESDAY...UPPER RIDGE REMAINS OVERHEAD WITH A MODEST AMOUNT OF MID LEVEL MOISTURE OVER THE REGION. BEST CHANCES FOR DIURNAL CONVECTION WILL BE OVER AND NEAR THE MOUNTAINS. WITH WEAK WINDS ALOFT...ANTICIPATE CONVECTION WILL HAVE DIFFICULTY MOVING OFF OF THE HIGHER TERRAIN. NAM CONTINUES TO SHOW SOME INCREASED CAPE NEAR THE KANSAS BORDER DURING THE AFTERNOON AND EVENING. GIVEN THE LACK OF A SHORTWAVE...MAINTAINED SILENT POPS OVER THE PLAINS. WARM WEATHER CONTINUES WITH HIGHS ABOVE AVERAGE ON BOTH DAYS. .WEDNESDAY AND THURSDAY...AN UPPER TROUGH WILL APPROACH THE WEST COAST INCREASING THE INFLUX OF MONSOON MOISTURE INTO THE REGION. LATEST SIMULATIONS HAVE WEDNESDAY BEING THE WETTEST DAY OVER AND NEAR THE MOUNTAINS WITH GREATEST AMOUNT OF MOISTURE. GFS AND EC DEVELOP A TROUGH OVER THE REGION WHICH SLOWLY MOVES EAST ON THURSDAY. WITH THE TROUGH NEAR THE KANSAS BORDER BY THURSDAY AFTERNOON...CHANCES FOR CONVECTION WILL INCREASE NEAR THE KANSAS BORDER. HAVE CONCERNS THAT THE CONVECTIVE PARAMETERIZATION COULD BE INFLUENCING THE DEVELOPMENT OF THIS TROUGH...WHICH COULD AFFECT THE LOCATION...TIMING AND STRENGTH OF CONVECTION. .FRIDAY AND SATURDAY...MODELS HAVE DIFFERENCES IN THE SPEED OF THE NEXT TROUGH MOVING INTO THE PACIFIC NORTHWEST. GENERAL TREND WILL BE TO TURN FLOW ALOFT MORE SOUTHWESTERLY BRINGING DRIER AIR ALOFT INTO THE REGION. GRIDS GENERALLY HAVE ISOLATED TO SCATTERED CONVECTION MOSTLY CONFINED TO THE MOUNTAINS WITH TEMPERATURE NEAR OR ABOVE NORMAL. --PGW-- && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 534 AM MDT SUN AUG 23 2015 COLD FRONT HAS BROUGHT WIDESPREAD MID LEVEL CLOUDS TO THE EASTERN MOUNTAINS AND PLAINS THIS MORNING. THE FRONT HAS EVEN PUSHED LOW CLOUDS UP INTO PARTS OF THE UPPER ARKANSAS RIVER VALLEY. SKIES OVER THE SAN LUIS VALLEY AND SOUTHWEST MOUNTAINS ARE GENERALLY CLEAR OR PARTLY CLOUDY...ALTHOUGH SKIES OVER THE SAN JUANS ARE MOSTLY CLOUDY. LITTLE OR NO PRECIPITATION ACROSS THE FLIGHT AREA AT THIS TIME BUT THERE ARE SOME POCKETS OF MVFR/IFR/LIFR CLOUDS OVER THE CENTRAL AND EASTERN MOUNTAINS...AND THE UPPER ARKANSAS RIVER VALLEY. OUTSIDE OF THE LOW CLOUDS...CONDITIONS ARE VFR THIS MORNING. MUCH OF THE CLOUDINESS SHOULD DISSIPATE WITHIN A FEW HOURS OF SUNRISE THIS MORNING. THEN...AFTER ABOUT 17Z...ISOLATED THUNDERSTORMS WILL START TO DEVELOP OVER THE MOUNTAINS AND HIGH VALLEYS...INCREASING IN COVERAGE THROUGH THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN PORTIONS OF THE MOUNTAINS AND SAN LUIS VALLEY. A FEW STORMS COULD DRIFT OVER THE I-25 CORRIDOR BETWEEN ROUGHLY 22Z AND 02Z...BUT THESE ARE EXPECTED TO BE ISOLATED AND WEAK DUE TO A RELATIVELY COOL...STABLE AIRMASS SITUATED OVER THE PLAINS. GENERALLY VFR ACROSS THE FLIGHT AREA TODAY AND TONIGHT...ALTHOUGH LOCAL MVFR/IFR/LIFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWER OR THUNDERSTORM ACTIVITY. FOR KCOS AND KPUB...STRATUS CLOUD BASES THIS MORNING EXPECTED TO REMAIN HIGH ENOUGH FOR VFR. NO THUNDERSTORMS IN FORECAST FOR THESE 2 SITES IN THE AFTERNOON AS THE AIRMASS SHOULD BE TOO STABLE. FOR KALS...NO STRATUS DECK THIS MORNING...BUT COULD BE SOME THUNDERSTORMS IN THE AFTERNOON. THUS...12Z ISSUANCE OF TAFS WILL INCLUDE MENTION OF VCTS AFTER 21Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...LW SHORT TERM...LW LONG TERM...PGW AVIATION...LW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
535 AM MDT SUN AUG 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 534 AM MDT SUN AUG 23 2015 ...THUNDERSTORMS MAINLY MOUNTAINS TODAY... COLD FRONT HAS PUSHED A MASS OF RELATIVELY COOL STABLE AIR SOUTH ACROSS THE PLAINS...WITH WIDESPREAD MID LEVEL CLOUDS ACROSS THE EASTERN MOUNTAINS AND PLAINS BUT NO PRECIPITATION. THE MOUNTAINS AND HIGH VALLEYS TO THE WEST REMAIN CLEAR TO PARTLY CLOUDY...WITH SOME MOSTLY CLOUDY SKIES OVER THE EASTERN SAN JUANS. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW THE ONLY REAL PROSPECTS FOR THUNDERSTORMS TO BE OVER THE MOUNTAINS AND HIGH VALLEYS. THE PLAINS SOUNDINGS SHOW A STRONG CAP. OF NOTE...HOWEVER...ARE RUNS OF THE EXPERIMENTAL HRRR AND...TO A LESSER EXTENT...THE 4KM NSSL WRF...THAT SHOW SOME CONVECTION MOVING OFF THE MOUNTAINS AND ACROSS THE I-25 CORRIDOR...MAINLY BETWEEN 4 PM AND 8 PM. NOT SURE IF THIS WILL HAPPEN GIVEN THE STRONG CAP INDICATED IN THE FORECAST SOUNDINGS BUT SOMETHING TO KEEP AN EYE ON. PROBABLY WHAT THESE MODELS ARE DOING IS DEVELOPING ELEVATED CONVECTION...AND TRACKING IT SOUTHEAST ACROSS THE PLAINS...ABOVE THE STABLE AIR. USUALLY WHEN THIS HAPPENS...HOWEVER...ANY ELEVATED CONVECTION DIES OUT ONCE IT MOVES OVER THE STABLE AIR. SO...SUSPECT THIS IS WHAT WILL HAPPEN. PRIMARY THREATS FROM STORMS OVER THE MOUNTAINS AND HIGH VALLEYS TODAY WILL BE LIGHTNING AND WIND GUSTS TO AROUND 40 MPH. THERE COULD ALSO BE SOME SPOTTY HEAVY RAIN OUT THERE. TEMPERATURES BEHIND THE COLD FRONT WILL BE ABOUT 15-20 DEGREES COOLER OVER THE EAST TODAY WITH COMFORTABLE HIGHS RANGING FROM THE MID 70S TO MID 80S. FOR THE MOUNTAINS AND HIGH VALLEYS...NOT QUITE AS MUCH COOLING...RANGING FROM JUST A COUPLE DEGREES COOLER IN SOME AREAS UP TO ABOUT 10 DEGREES COOLER IN OTHERS. HIGH VALLEY TEMPERATURES SHOULD RANGE FORM THE 70S TO LOWER 80S WITH MOUNTAIN READINGS MOSTLY IN THE 60S AND 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 534 AM MDT SUN AUG 23 2015 .MONDAY AND TUESDAY...UPPER RIDGE REMAINS OVERHEAD WITH A MODEST AMOUNT OF MID LEVEL MOISTURE OVER THE REGION. BEST CHANCES FOR DIURNAL CONVECTION WILL BE OVER AND NEAR THE MOUNTAINS. WITH WEAK WINDS ALOFT...ANTICIPATE CONVECTION WILL HAVE DIFFICULTY MOVING OFF OF THE HIGHER TERRAIN. NAM CONTINUES TO SHOW SOME INCREASED CAPE NEAR THE KANSAS BORDER DURING THE AFTERNOON AND EVENING. GIVEN THE LACK OF A SHORTWAVE...MAINTAINED SILENT POPS OVER THE PLAINS. WARM WEATHER CONTINUES WITH HIGHS ABOVE AVERAGE ON BOTH DAYS. .WEDNESDAY AND THURSDAY...AN UPPER TROUGH WILL APPROACH THE WEST COAST INCREASING THE INFLUX OF MONSOON MOISTURE INTO THE REGION. LATEST SIMULATIONS HAVE WEDNESDAY BEING THE WETTEST DAY OVER AND NEAR THE MOUNTAINS WITH GREATEST AMOUNT OF MOISTURE. GFS AND EC DEVELOP A TROUGH OVER THE REGION WHICH SLOWLY MOVES EAST ON THURSDAY. WITH THE TROUGH NEAR THE KANSAS BORDER BY THURSDAY AFTERNOON...CHANCES FOR CONVECTION WILL INCREASE NEAR THE KANSAS BORDER. HAVE CONCERNS THAT THE CONVECTIVE PARAMETERIZATION COULD BE INFLUENCING THE DEVELOPMENT OF THIS TROUGH...WHICH COULD AFFECT THE LOCATION...TIMING AND STRENGTH OF CONVECTION. .FRIDAY AND SATURDAY...MODELS HAVE DIFFERENCES IN THE SPEED OF THE NEXT TROUGH MOVING INTO THE PACIFIC NORTHWEST. GENERAL TREND WILL BE TO TURN FLOW ALOFT MORE SOUTHWESTERLY BRINGING DRIER AIR ALOFT INTO THE REGION. GRIDS GENERALLY HAVE ISOLATED TO SCATTERED CONVECTION MOSTLY CONFINED TO THE MOUNTAINS WITH TEMPERATURE NEAR OR ABOVE NORMAL. --PGW-- && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 534 AM MDT SUN AUG 23 2015 COLD FRONT HAS BROUGHT WIDESPREAD MID LEVEL CLOUDS TO THE EASTERN MOUNTAINS AND PLAINS THIS MORNING. THE FRONT HAS EVEN PUSHED LOW CLOUDS UP INTO PARTS OF THE UPPER ARKANSAS RIVER VALLEY. SKIES OVER THE SAN LUIS VALLEY AND SOUTHWEST MOUNTAINS ARE GENERALLY CLEAR OR PARTLY CLOUDY...ALTHOUGH SKIES OVER THE SAN JUANS ARE MOSTLY CLOUDY. LITTLE OR NO PRECIPITATION ACROSS THE FLIGHT AREA AT THIS TIME BUT THERE ARE SOME POCKETS OF MVFR/IFR/LIFR CLOUDS OVER THE CENTRAL AND EASTERN MOUNTAINS...AND THE UPPER ARKANSAS RIVER VALLEY. OUTSIDE OF THE LOW CLOUDS...CONDITIONS ARE VFR THIS MORNING. MUCH OF THE CLOUDINESS SHOULD DISSIPATE WITHIN A FEW HOURS OF SUNRISE THIS MORNING. THEN...AFTER ABOUT 17Z...ISOLATED THUNDERSTORMS WILL START TO DEVELOP OVER THE MOUNTAINS AND HIGH VALLEYS...INCREASING IN COVERAGE THROUGH THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN PORTIONS OF THE MOUNTAINS AND SAN LUIS VALLEY. A FEW STORMS COULD DRIFT OVER THE I-25 CORRIDOR BETWEEN ROUGHLY 22Z AND 02Z...BUT THESE ARE EXPECTED TO BE ISOLATED AND WEAK DUE TO A RELATIVELY COOL...STABLE AIRMASS SITUATED OVER THE PLAINS. GENERALLY VFR ACROSS THE FLIGHT AREA TODAY AND TONIGHT...ALTHOUGH LOCAL MVFR/IFR/LIFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWER OR THUNDERSTORM ACTIVITY. FOR KCOS AND KPUB...STRATUS CLOUD BASES THIS MORNING EXPECTED TO REMAIN HIGH ENOUGH FOR VFR. NO THUNDERSTORMS IN FORECAST FOR THESE 2 SITES IN THE AFTERNOON AS THE AIRMASS SHOULD BE TOO STABLE. FOR KALS...NO STRATUS DECK THIS MORNING...BUT COULD BE SOME THUNDERSTORMS IN THE AFTERNOON. THUS...12Z ISSUANCE OF TAFS WILL INCLUDE MENTION OF VCTS AFTER 21Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LW LONG TERM...PGW AVIATION...LW
AREA FORECAST DISCUSSION...CORRECTED
NWS PUEBLO CO
444 AM MDT SUN AUG 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 444 AM MDT SUN AUG 23 2015 ...THUNDERSTORMS MAINLY MOUNTAINS TODAY... COLD FRONT HAS PUSHED A MASS OF RELATIVELY COOL STABLE AIR SOUTH ACROSS THE PLAINS...WITH WIDESPREAD MID LEVEL CLOUDS ACROSS THE EASTERN MOUNTAINS AND PLAINS BUT NO PRECIPITATION. THE MOUNTAINS AND HIGH VALLEYS TO THE WEST REMAIN CLEAR TO PARTLY CLOUDY...WITH SOME MOSTLY CLOUDY SKIES OVER THE EASTERN SAN JUANS. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW THE ONLY REAL PROSPECTS FOR THUNDERSTORMS TO BE OVER THE MOUNTAINS AND HIGH VALLEYS. THE PLAINS SOUNDINGS SHOW A STRONG CAP. OF NOTE...HOWEVER...ARE RUNS OF THE EXPERIMENTAL HRRR AND...TO A LESSER EXTENT...THE 4KM NSSL WRF...THAT SHOW SOME CONVECTION MOVING OFF THE MOUNTAINS AND ACROSS THE I-25 CORRIDOR...MAINLY BETWEEN 4 PM AND 8 PM. NOT SURE IF THIS WILL HAPPEN GIVEN THE STRONG CAP INDICATED IN THE FORECAST SOUNDINGS BUT SOMETHING TO KEEP AN EYE ON. PROBABLY WHAT THESE MODELS ARE DOING IS DEVELOPING ELEVATED CONVECTION...AND TRACKING IT SOUTHEAST ACROSS THE PLAINS...ABOVE THE STABLE AIR. USUALLY WHEN THIS HAPPENS...HOWEVER...ANY ELEVATED CONVECTION DIES OUT ONCE IT MOVES OVER THE STABLE AIR. SO...SUSPECT THIS IS WHAT WILL HAPPEN. PRIMARY THREATS FROM STORMS OVER THE MOUNTAINS AND HIGH VALLEYS TODAY WILL BE LIGHTNING AND WIND GUSTS TO AROUND 40 MPH. THERE COULD ALSO BE SOME SPOTTY HEAVY RAIN OUT THERE. TEMPERATURES BEHIND THE COLD FRONT WILL BE ABOUT 15-20 DEGREES COOLER OVER THE EAST TODAY WITH COMFORTABLE HIGHS RANGING FROM THE MID 70S TO MID 80S. FOR THE MOUNTAINS AND HIGH VALLEYS...NOT QUITE AS MUCH COOLING...RANGING FROM JUST A COUPLE DEGREES COOLER IN SOME AREAS UP TO ABOUT 10 DEGREES COOLER IN OTHERS. HIGH VALLEY TEMPERATURES SHOULD RANGE FORM THE 70S TO LOWER 80S WITH MOUNTAIN READINGS MOSTLY IN THE 60S AND 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 444 AM MDT SUN AUG 23 2015 .MONDAY AND TUESDAY...UPPER RIDGE REMAINS OVERHEAD WITH A MODEST AMOUNT OF MID LEVEL MOISTURE OVER THE REGION. BEST CHANCES FOR DIURNAL CONVECTION WILL BE OVER AND NEAR THE MOUNTAINS. WITH WEAK WINDS ALOFT...ANTICIPATE CONVECTION WILL HAVE DIFFICULTY MOVING OFF OF THE HIGHER TERRAIN. NAM CONTINUES TO SHOW SOME INCREASED CAPE NEAR THE KANSAS BORDER DURING THE AFTERNOON AND EVENING. GIVEN THE LACK OF A SHORTWAVE...MAINTAINED SILENT POPS OVER THE PLAINS. WARM WEATHER CONTINUES WITH HIGHS ABOVE AVERAGE ON BOTH DAYS. .WEDNESDAY AND THURSDAY...AN UPPER TROUGH WILL APPROACH THE WEST COAST INCREASING THE INFLUX OF MONSOON MOISTURE INTO THE REGION. LATEST SIMULATIONS HAVE WEDNESDAY BEING THE WETTEST DAY OVER AND NEAR THE MOUNTAINS WITH GREATEST AMOUNT OF MOISTURE. GFS AND EC DEVELOP A TROUGH OVER THE REGION WHICH SLOWLY MOVES EAST ON THURSDAY. WITH THE TROUGH NEAR THE KANSAS BORDER BY THURSDAY AFTERNOON...CHANCES FOR CONVECTION WILL INCREASE NEAR THE KANSAS BORDER. HAVE CONCERNS THAT THE CONVECTIVE PARAMETERIZATION COULD BE INFLUENCING THE DEVELOPMENT OF THIS TROUGH...WHICH COULD AFFECT THE LOCATION...TIMING AND STRENGTH OF CONVECTION. .FRIDAY AND SATURDAY...MODELS HAVE DIFFERENCES IN THE SPEED OF THE NEXT TROUGH MOVING INTO THE PACIFIC NORTHWEST. GENERAL TREND WILL BE TO TURN FLOW ALOFT MORE SOUTHWESTERLY BRINGING DRIER AIR ALOFT INTO THE REGION. GRIDS GENERALLY HAVE ISOLATED TO SCATTERED CONVECTION MOSTLY CONFINED TO THE MOUNTAINS WITH TEMPERATURE NEAR OR ABOVE NORMAL. --PGW-- && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 444 AM MDT SUN AUG 23 2015 COLD FRONT HAS BROUGHT WIDESPREAD MID LEVEL CLOUDS TO THE EASTERN MOUNTAINS AND PLAINS THIS MORNING. THE FRONT HAS EVEN PUSHED LOW CLOUDS UP INTO PARTS OF THE UPPER ARKANSAS RIVER VALLEY. SKIES OVER THE SAN LUIS VALLEY AND SOUTHWEST MOUNTAINS ARE GENERALLY CLEAR OR PARTLY CLOUDY...ALTHOUGH SKIES OVER THE SAN JUANS ARE MOSTLY CLOUDY. LITTLE OR NO PRECIPITATION ACROSS THE FLIGHT AREA AT THIS TIME BUT THERE ARE SOME POCKETS OF MVFR/IFR/LIFR CLOUDS OVER THE CENTRAL AND EASTERN MOUNTAINS...AND THE UPPER ARKANSAS RIVER VALLEY. OUTSIDE OF THE LOW CLOUDS...CONDITIONS ARE VFR THIS MORNING. MUCH OF THE CLOUDINESS SHOULD DISSIPATE WITHIN A FEW HOURS OF SUNRISE THIS MORNING. THEN...AFTER ABOUT 17Z...ISOLATED THUNDERSTORMS WILL START TO DEVELOP OVER THE MOUNTAINS AND HIGH VALLEYS...INCREASING IN COVERAGE THROUGH THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN PORTIONS OF THE MOUNTAINS AND SAN LUIS VALLEY. A FEW STORMS COULD DRIFT OVER THE I-25 CORRIDOR BETWEEN ROUGHLY 22Z AND 02Z...BUT THESE ARE EXPECTED TO BE ISOLATED AND WEAK DUE TO A RELATIVELY COOL...STABLE AIRMASS SITUATED OVER THE PLAINS. GENERALLY VFR ACROSS THE FLIGHT AREA TODAY AND TONIGHT...ALTHOUGH LOCAL MVFR/IFR/LIFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWER OR THUNDERSTORM ACTIVITY. FOR KCOS AND KPUB...STRATUS CLOUD BASES THIS MORNING EXPECTED TO REMAIN HIGH ENOUGH FOR VFR. NO THUNDERSTORMS IN FORECAST FOR THESE 2 SITES IN THE AFTERNOON AS THE AIRMASS SHOULD BE TOO STABLE. FOR KALS...NO STRATUS DECK THIS MORNING...BUT COULD BE SOME THUNDERSTORMS IN THE AFTERNOON. THUS...12Z ISSUANCE OF TAFS WILL INCLUDE MENTION OF VCTS AFTER 21Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LW LONG TERM...PGW AVIATION...LW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1051 PM EDT MON AUG 24 2015 .SYNOPSIS... A WEAK COLD FRONT APPROACHES TONIGHT...THEN SLOWLY MOVES OVER THE REGION TUESDAY...AND THEN EXITS TO THE EAST TUESDAY NIGHT. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT THROUGH THURSDAY NIGHT...THEN REMAINS ACROSS THE AREA THROUGH NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... LATEST HI-RES GUIDANCE MODELS SUGGEST EASTERN AREAS SHOULD REMAIN DRY THROUGH AT LEAST 6Z...HAVE ADJUSTED POPS ACCORDINGLY. ALSO HAVE SLIGHTLY SLOWED ONSET FARTHER WEST AS WELL BASED ON LATEST RADAR TRENDS. NEGATIVE VORTICITY ADVECTION AT 500-700 HPA IS REASON FOR CURRENT LULL IN PRECIPITATION. LARGE SCALE MODELS ARE NOT HANDLING THIS WELL AT ALL...ARE OVERDONE WITH QPF THIS EVENING AS A RESULT. HRRR AND RUC HANDLING CURRENT WEATHER BEST SO FAR...SO LEANED ON FOR UPDATE. BASED ON THIS...HAVE BASICALLY GONE DRY E OF THE HUDSON FOR TONIGHT...WITH SLIGHT CHANCE POPS W OF THE HUDSON...MAINLY FOR AFTER MIDNIGHT. WITH NO PRECIPITATION FORECAST NOW TO AID IN LOW LEVEL MIXING...POTENTIAL FOR FOG OVERNIGHT IS INCREASING. LEFT AS PATCHY FOR NOW...BUT WOULD NOT BE SURPRISED IF ENDED UP WITH CLOSER TO AREAS OF FOG. ALSO WOULD NOT BE SURPRISED IF SOME AREAS ENDED UP WITH DENSE FOG...BUT NOT YET CONFIDENT ENOUGH IN PLACEMENT OR OCCURRENCE TO PUT IN THE FORECAST AT THIS TIME. LOW TEMPERATURE FORECAST MAINLY ON TRACK...LOWS SHOULD BE AROUND 5-10 DEGREES ABOVE NORMAL. THERE IS A MODERATE RISK FOR THE METEOROLOGICAL ENHANCEMENT OF RIP CURRENT DEVELOPMENT AT ATLANTIC OCEAN BEACHES TONIGHT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... INITIALLY...A NEARLY STEADY HEIGHT TREND IN THE MID LEVELS WITH THE MAIN UPPER LEVEL LOW STAYING JUST NORTH OF THE GREAT LAKES. THIS IS FORECAST TO BE RIGHT ABOVE THE SURFACE LOW. HENCE...THIS WILL BE UNFAVORABLE FOR CYCLOGENESIS AND THE LOW BECOMES EQUIVALENT BAROTROPIC. THE FRONT ASSOCIATED WITH IT SLOWS DOWN AND WEAKENS FURTHER WITHIN THE REGION ON TUESDAY. THE MODELS DEPICT SOME SMALLER AREAS OF LOW PRESSURE ALONG IT. THE INSTABILITY BECOMES MORE SURFACE BASED...AND CAPE INCREASES TO ABOUT 1000-1500 J/KG. SCATTERED SHOWERS AND THUNDERSTORMS ARE IN THE FORECAST FOR THE DAY...BUT THESE WILL BE MORE FREQUENT FOR LONG ISLAND AND SOUTHERN CT AS THOSE WILL BE LOCATIONS WITHIN GREATER INSTABILITY. MESOSCALE MODELS DID NOT DEPICT MUCH AT ALL IN THE WAY OF SHOWERS AND THUNDERSTORMS AND MODEL QPF IS NOT THAT HIGH...SO CAPPED POPS AT 54 PERCENT TO STAY IN THE SCATTERED COVERAGE. AS MENTIONED BEFORE...THE FRONT AND PARENT LOW ARE WEAKENING SO THERE WILL BE LESS AND LESS SYNOPTIC FORCING AS THE DAY PROGRESSES. HIGHS TUESDAY WERE A BLEND OF MOS YIELDING VALUES IN THE LOW TO UPPER 80S. THE FRONT EXITS TO THE EAST OF THE REGION TUESDAY NIGHT. DRYING CONDITIONS WILL OCCUR WITH A REMARKABLE LOWERING OF HUMIDITY AS DEWPOINTS LOWER INTO THE MID 50S TO NEAR 60. LOWS AT NIGHT FORECAST TO MAINLY RANGE FROM THE MID 50S TO MID 60S. THERE IS A MODERATE RISK FOR THE METEOROLOGICAL ENHANCEMENT OF RIP CURRENT DEVELOPMENT AT ATLANTIC OCEAN BEACHES INTO TUESDAY EVENING. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGH PRESSURE WILL BE THE MAIN FEATURE THROUGH THE WEEKEND...WITH A WEAK COLD FRONT OR TROUGH POSSIBLY SHIFTING THROUGH THE REGION ON MONDAY. CYCLONIC FLOW ALOFT ON WEDNESDAY AND THURSDAY PROBABLY RESULTS IN NOTHING MORE THAN SOME DIURNAL CU...MAINLY OVER THE NORTHERN ZONES. THE FLOW ALOFT THEN BECOMES ANTICYCLONIC FOR FRIDAY WITH SUNNY CONDITIONS ACROSS THE CWA. THE FLOW THEN FLATTENS SOMEWHAT OVER THE WEEKEND...AND THE OVERALL DEPTH OF MOISTURE INCREASES. THERE IS SOME UNCERTAINTY REGARDING THE TIMING AND PLACEMENT OF A COUPLE OF SHORTWAVES. IT APPEARS THAT SUNDAY WOULD MORE LIKELY FEATURE AN ISOLATED SHOWER/TSTM IF ANYTHING POPS UP...BUT FOR NOW WILL KEEP THE FORECAST DRY THROUGH THE WEEKEND. A WEAK COLD FRONT OR TROUGH IS THEN PROGGED TO PASS THROUGH SOMETIME MONDAY OR MONDAY NIGHT. WILL PUT IN SLIGHT CHANCE POPS IN THE GRIDS FOR THIS PERIOD. ALTHOUGH HIGH TEMPERATURES THROUGH THE LONG TERM WILL LIKELY AVERAGE ABOVE NORMAL EACH DAY...EXCESSIVE HEAT IS NOT EXPECTED. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... COLD FRONT SLOWLY APPROACHES TONIGHT...AND THEN SLOWLY MOVES EAST THROUGH THE REGION ON TUESDAY. MAINLY VFR THROUGH MIDNIGHT...THEN WIDELY ISO SHRA/TSRA...AND POTENTIAL MVFR CONDITIONS LATE TONIGHT INTO EARLY MORNING AHEAD OF APPROACHING COLD FRONT. MVFR/IFR CONDS EXPECTED FOR KGON...AND LIKELY AT KHPN/KSWF AT THAT TIME. GRADUALLY IMPROVING CONDS TO VFR TUE MORNING FOR NYC METRO AND WESTERN TERMINALS...BUT MVFR CONDS COULD LINGER INTO AFTERNOON ACROSS EASTERN TERMINALS. ISO-SCT SHRA/TSRA POTENTIAL MAINLY ACROSS EASTERN TERMINALS IN AFTERNOON. .OUTLOOK FOR 00Z TUESDAY THROUGH SATURDAY... .TUESDAY NIGHT...COLD FRONTAL PASSAGE IN EVENING WITH WINDSHIFT TO W/NW...END OF SHRA/TSRA THREAT...AND VFR. .WEDNESDAY THROUGH SATURDAY...VFR. MORNING W/NW FLOW GIVING WAY TO AFTERNOON W/SW FLOW AND COASTAL SEABREEZES. && .MARINE... MINOR CHANGES WERE MADE WITH THIS UPDATE TO REFLECT THE LATEST TRENDS IN OBSERVATIONS AND GUIDANCE. MAIN CHANGE WAS TO REMOVE PRECIPITATION FROM THE WATERS OVERNIGHT. A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN ACROSS THE WATERS THROUGH TUESDAY NIGHT. AS SUCH...CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA LEVELS. EXPECT SUB SCA CONDITIONS FOR THE REST OF THE FORECAST PERIOD AS HIGH PRESSURE BUILDS TOWARD THE WATERS WITH A RELATIVELY WEAK PRESSURE GRADIENT. && .HYDROLOGY... RAINFALL AMOUNTS INTO TUESDAY NIGHT WILL AVERAGE BETWEEN ONE TO THREE TENTHS OF AN INCH. LOCALLY HIGHER AMOUNTS ARE POSSIBLE FOR ANY AREAS THAT RECEIVE THUNDERSTORMS. WITH PRECIPITABLE WATERS APPROACHING 1.5 TO 1.7 INCH ON TUESDAY...ISOLATED SPOTS COULD RECEIVE OVER AN INCH OF RAINFALL. MOSTLY MINOR FLOODING WILL BE A POSSIBILITY. NO SIGNIFICANT WIDESPREAD RAINFALL IS EXPECTED THROUGH AT LEAST THE WEEKEND. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JM/JC NEAR TERM...MALOIT SHORT TERM...JM LONG TERM...JC AVIATION...NV MARINE...MALOIT/JM/JC HYDROLOGY...JM/JC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1022 PM EDT MON AUG 24 2015 .SYNOPSIS... COLD FRONT APPROACHES FROM THE WEST TONIGHT AND CROSSES NEW ENGLAND TUESDAY NIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THIS FRONT. MAINLY DRY AND SEASONABLE WEATHER WITH COMFORTABLE HUMIDITY LEVELS FOLLOWS WEDNESDAY THROUGH SATURDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 1015 PM UPDATE... WIDELY SCT SHOWERS/TSTMS CONFINED TO THE WEST OF NEW ENG FROM E NY TO NE PA. ACTIVITY IS NOT MAKING MUCH PROGRESS EAST AS IT TRACKS SLOWLY NE. HRRR AND HIRES ARW BRING SOME ELEVATED CONVECTION INTO FAR W NEW ENG VERY LATE TONIGHT. IN ADDITION...WATCHING AREA OF SHOWERS WELL TO THE S ASSOCD WITH HIGHER THETA-E AIR AND SOME ELEVATED INSTABILITY. MODELS BRING THIS NWD ACROSS CAPE/ISLANDS LATE TONIGHT SO CANT RULE AN ISOLD SHOWER HERE OVERNIGHT AS WELL. OTHERWISE...MAINLY DRY OVERNIGHT. CURRENTLY WE HAVE 1000-1500 J/KG OF SBCAPE OFFSHORE TO THE S. MODELS BRING UP TO 1000 J/KG ACROSS SE NEW ENG TOWARD 12Z SO WILL HAVE TO WATCH FOR POSSIBLE DEVELOPMENT NEAR THE S COAST BUT THERE IS NO FORCING MECHANISM. STRATUS HAS DEVELOPED ALONG THE S COAST AND WITH LIGHT SOUTHERLY FLOW MAY SEE THIS ADVECT FURTHER NWD ACROSS SNE. PATCHY FOG POSSIBLE AS WELL...ESPECIALLY NEAR THE S COAST. A WARM AND HUMID NIGHT WITH MINS UPPER 60S TO AROUND 70 WITH SIMILAR DEWPOINTS. && .SHORT TERM /6 AM TUESDAY THROUGH 6 AM TUESDAY/... CLOSED UPPER LOW MOVES TO EASTERN CANADA WITH CYCLONIC FLOW ACROSS THE EASTERN USA. SURFACE COLD FRONT IS FORECAST IN/NEAR THE HUDSON VALLEY AND ROUGHLY PARALLEL TO THE UPPER FLOW. THE GFS IS A LITTLE MORE PROGRESSIVE THAN THE ECMWF BUT BOTH HOLD THE FRONT EITHER SIDE OF THE NEW ENGLAND BORDER TUESDAY EVENING. BOTH MODELS THEN SWEEP THE FRONT EAST ACROSS NEW ENGLAND TUESDAY NIGHT. STABILITY PARAMETERS ARE FAVORABLE FOR CONVECTION WITH TOTALS MID TO UPPER 40S/LI AROUND ZERO/SBCAPE 1000-3000 J/KG. WIND FIELDS ALOFT ALSO PICK UP WITH SPEEDS NEAR 20 KNOTS AT 850 MB AND 40 KNOTS AT 500 MB. THE MOST FAVORABLE AREA FOR CONVECTION WOULD BE WESTERN/CENTRAL MASS AND POSSIBLY PARTS OF NORTHERN CT. THE BEST MODE OF DAMAGING WEATHER WOULD BE STRONG WIND GUSTS. WILL THERE BE A MORNING ROUND OF SHOWERS/TSTMS? BOTH THE GFS AND ECMWF INDICATE INCREASED SBCAPE OVER RI AND SOUTHEAST MASS AT 12Z. COULD BE A QUICK MORNING BURST. MAIN EVENT SHOULD BE FARTHER WEST IN THE AFTERNOON/EVENING. COLD FRONT THEN SLIPS THROUGH DURING TUESDAY NIGHT WITH SHOWERS/TSTMS ENDING...AND DRIER AIR FILTERING IN FROM THE WEST. PRECIPITABLE WATER VALUES WILL BE 1.5 TO 1.75 INCHES...SO LOCALLY HEAVY DOWNPOURS POSSIBLE. TEMPS AT 900 MB ARE EQUIV TO 13C AT 850 MB...MAX SFC TEMPS IN THE LOW TO MID 80S EXCEPT COOLER ALONG THE COAST AND IN THE HIGHER HILLS. MIN SFC TEMPS SHOULD REMAIN IN THE 60S IN THE EAST BUT WILL REACH THE UPPER 50S IN WESTERN MASS. && .LONG TERM /TUESDAY THROUGH MONDAY/... HIGHLIGHTS... * MAINLY DRY/SEASONABLE WITH COMFORTABLE HUMIDITY WED THROUGH SAT * ABOVE NORMAL TEMPS AND HUMIDITY LOOKS TO RETURN EARLY NEXT WEEK OVERVIEW AND MODEL PREFERENCES... 24.12Z MODEL GUIDANCE IS SHOWING LITTLE DIFFERENCE THROUGH MUCH OF THE LONG TERM. AT THE VERY LEAST ANY DIFFERENCES ARE MINIMAL ENOUGH SO AS NOT TO IMPACT THE FORECAST SIGNIFICANTLY. AT THE VERY LEAST...THE PATTERN SHIFT WE HAVE BEEN WAITING FOR NOW FOR ALMOST A WEEK IS AT HAND. UPPER LVL CUTOFF MOVES INTO QUEBEC/LABRADOR ALTHOUGH WITH A SLIGHT REMNANT OF THE ATTENDANT TROF ACROSS THE NE CONUS THROUGH THE END OF THE WEEK. A ZONAL FLOW PATTERN WILL FINALLY DEFINE MUCH OF THE NRN PERIPHERY OF THE CONUS...WITH DRIER CP AIRMASS DRAW INTO NEW ENGLAND. NOTING A SLIGHT SLACKENING OF THE MASS FIELDS TO THE S BY LATE IN THE WEEKEND...WHICH COULD SHIFT THE FLOW PATTERN INCREASING TEMPS/DWPTS AND A RISK FOR SCT PRECIPITATION. WITH THE AGREEMENT...A BLEND OF OPERATIONAL GUIDANCE WILL BE USED. DETAILS... WED... MODELS CONTINUE TO INDICATE THE POSSIBILITY OF WEAK CYCLOGENESIS IN THE GULF OF MAINE ALONG THE SLOW MOVING COLD FRONT. COMBINE THIS WITH STRONG CYCLONIC/COLD UPPER FLOW WITH THE UPPER LVL CUTOFF MAKING IT/S CLOSEST PASS...AND WILL LIKELY SEE A FAIR AMOUNT OF DIURNAL AND LEFTOVER CLOUD COVER THROUGH THE DAY...ALTHOUGH IT WILL LIKELY REMAIN DRY. A SPOT SHOWER CAN/T BE RULED OUT AS BUFKIT DATA SUPPORTS A WEAK UNSTABLE LATER NEAR THE TOP OF THE BL WHICH COULD BE JUST ENOUGH TO SQUEEZE OUT WHAT LITTLE MOISTURE IS THERE. IN SPITE OF THE -10 TO -11C H5 TEMPERATURES...FEEL RISK FOR SMALL HAIL IS LOW IN SPITE OF THE GOOD SETUP AS THERE IS A FAIRLY PRONOUNCED WARM LAYER BETWEEN H8 AND H6. H85 TEMPERATURES BETWEEN 12 AND 14C SHOULD BE REALIZED AT LEAST...SO TEMPERATURES NEAR SEASONAL LEVELS /UPPER 70S AND LOW 80S/ ARE EXPECTED. THE BEST NEWS...DWPTS MAINLY IN THE 50S. THU AND FRI... PLEASANT CONDITIONS. LITTLE CHANGE IN MID LEVEL TEMPERATURES SUGGEST HIGHS REMAIN NEAR NORMAL. LOW DWPTS IN THE 50S...AND MAY EVEN DIP INTO THE 40S LOCALLY. OVERNIGHT MINS IN THE 50S. SAT AND SUN... ZONAL FLOW BUT WITH SRN NEW ENGLAND ON THE ANTICYCLONIC SHEAR SIDE. THEREFORE...FEEL THAT GFS IS A BIT OVERDONE TRYING TO BRING ABOUT SHRA ACTIVITY EACH AFTERNOON. FOR NOW WILL CONTINUE WITH NIL POPS. INCREASING MID LVL TEMPS AND MOISTURE ARE EXPECTED...ALTHOUGH ONLY SLIGHTLY THROUGH THE WEEKEND. EARLY NEXT WEEK... A STRONGER SHORTWAVE WILL ATTEMPT TO PHASE WITH THE SLACKENED MASS FIELDS S OF THE REGION. THIS MAY LEAD TO A SHIFT IN THE PATTERN SUCH THAT WARMING/MOISTENING IS EXPECTED. THE SFC REFLECTION LOOKS TO BE A WEAK WARM FRONT...WHICH COULD INCREASE THE RISK FOR SHRA/TSTORMS BY THIS TIME PERIOD. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THIS AFTERNOON THROUGH TONIGHT/... 00Z UPDATE...NO SIGNIFICANT CHANGES. MAY BE A BIT MORE VFR THAN PREVIOUSLY FORECAST. BUT EXPECT SOME MVFR/IFR CONDITIONS LATE. TONIGHT...MODERATE CONFIDENCE. IFR CIGS ALONG THE SOUTH COAST MAY LOWER TO MVFR/IFR ELSEWHERE BUT CONFIDENCE IS LOWER FURTHER INLAND. PATCHY FOG POSSIBLE AS WELL. WIDELY SCT SHOWERS/TSTMS IN NEW YORK WILL MOVE INTO WESTERN SECTIONS WELL AFTER MIDNIGHT. TUESDAY...LOW CLOUDS AND FOG IN THE MORNING ESPECIALLY ON THE ISLANDS AND SOUTH COAST. A FEW MORNING SHOWERS/TSTM WILL ALSO BRING BRIEF MVFR/IFR CONDITIONS. SHOWERS/TSTMS WILL REFIRE IN THE AFTERNOON...WITH BEST CHANCES IN HFD-SPRINGFIELD-WORCESTER AND NORTHERN MASS. OTHERWISE VFR. TUESDAY NIGHT...COLD FRONT MOVES THROUGH OVERNIGHT WITH A WIND SHIFT FROM SOUTH TO WEST. EVENING SHOWERS/TSTMS SHOULD TAPER OFF. MVFR IN ANY SHOWERS/TSTMS AND IFR IN ANY PATCHY GROUND FOG OVERNIGHT. OTHERWISE VFR. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR CONDITIONS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...MODERATE TO HIGH CONFIDENCE. TONIGHT...HIGH CONFIDENCE. SOUTH TO SOUTH WINDS 10-15 KT OR LESS. SEAS BELOW 5 FT. AREAS OF FOG WITH POOR VISIBILITY. SHOWERS/SCATTERED TSTMS MAY REACH THE WATERS TOWARD MORNING. TUESDAY...WINDS IN ANY TSTMS MAY GUST TO NEAR 35 KNOTS. LOCALLY POOR VSBYS IN MORNING FOG. OTHERWISE WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS. OUTLOOK /WEDNESDAY THROUGH SATURDAY/...HIGH CONFIDENCE. A PERIOD OF QUIET BOATING WEATHER IS EXPECTED THANKS TO SLOW MOVING HIGH PRES WHICH WILL GRADUALLY BUILD OVER THE WATERS THROUGH THE PERIOD. WINDS OUT OF THE W-NW THROUGH FRI...SHIFTING TO THE S SOMEWHAT BY SAT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/DOODY NEAR TERM...KJC SHORT TERM...WTB LONG TERM...DOODY AVIATION...WTB/KJC/DOODY MARINE...WTB/DOODY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
935 AM EDT SUN AUG 23 2015 .UPDATE... CURRENT-THIS AFTERNOON...HIGH PRESSURE STRETCHING FROM VIRGINIA TO MISSISSIPPI RIDGES OVER FLORIDA. CURRENT(9AM) WEATHER ROUNDUP INDICATING CALM TO LIGHT W THROUGH NE WINDS. WINDS BECOME NORTH TO NORTHEAST LATE MORNING AS WINDS OFF THE SURFACE MIX DOWN. SEA BREEZES AT THE COAST EARLY AFTERNOON PUSH INLAND THE REST OF THE DAY. PRECIPITABLE WATER VALUES AVERAGING AROUND 2 INCHES NORTH HALF OF FLORIDA. THE 12Z SOUNDINGS INDICATED THAT THE TEMPERATURES ALOFT WERE STILL QUICK WARM WITH -6C AT 500MB AND 10 TO 12C AT 700MB. THESE NUMBERS SUPPORT CHANCE/SCATTERED AFTERNOON POPS WHICH THE CURRENT FORECAST INDICATES. WILL UPDATE THE VARIOUS WINDS GRIDS FOR THE AFTERNOON AND BACKFILL THE GRIDS BEFORE 12Z. && .AVIATION...SYNOPTIC/MESOSCALE SETUP LOOKS SIMILAR TO SAT WITH PERHAPS A TOUGH MORE LOW LEVEL NE FLOW BUT STEERING WINDS OUT OF THE NORTH ONCE AGAIN. HRRR ALSO SHOWS DIURNAL CONVECTIVE EVOLUTION VERY SIMILAR TO SATURDAY. CONSEQUENTLY...EXPECT ISOLD TS TO SET UP WEST OF THE DAB-SUA CORRIDOR AROUND 17Z...WITH SEA BREEZE CARRYING THE ACTIVITY WELL INLAND AFTER 19Z. POPS SUPPORT MENTION OF VCTS...16Z- 19Z FOR THE COAST...AND 18Z-23Z FOR THE INTERIOR...WITH VARIANCE IN TIMING DEPENDING ON THE LOCATION. && .MARINE... CURRENT-THIS AFTERNOON...BUOYS RECORDING NW-NNE WINDS 5 TO 10 KNOTS AND 1 TO 2 FOOT SEAS. NEARSHORE WINDS TO BECOME ONSHORE AND PICK UP TO AROUND 10 KNOTS ONCE THE SEA BREEZES KICK IN AND PUSH INLAND. CURRENT MARINE FORECAST SHOWS THE TRANSITION AND SPEEDS TO BE UPDATE ALONG WITH ZONES(ON LAND) WINDS. && IMPACT WX/AVIATION...CRISTALDI UPDATES/FORECASTS....WIMMER && .PREVIOUS DISCUSSION... /ISSUED 340 AM EDT SUN AUG 23 2015/ TONIGHT...ONSHORE WINDS WILL WEAKEN TONIGHT AND BECOME LIGHT. ENOUGH DRYING IS ANTICIPATED TO KEEP POPS OUT OF THE FORECAST. MON-MON NIGHT...AN ELONGATED SHORTWAVE TROUGH IN THE MID-LEVELS ACROSS THE DEEP SOUTH EARLY IN THE PERIOD WILL SLIDE DOWN INTO THE CENTRAL FLORIDA PENINSULA DURING THE DAY AND WEAKEN. WEAK HIGH PRESSURE WILL BE OVER ECFL AS A WEAK FRONTAL BOUNDARY SETS UP OVER THE GULF COAST STATES AND ACROSS THE SOUTHEAST U.S. LIGHT/VARIABLE EARLY MORNING WINDS WILL BECOME LIGHT NNE/NE THROUGH THE DAY. THE ECSB WILL DEVELOP AND MOVE INLAND WITH ONLY A SMALL THREAT FOR A SHOWER/STORM OVER COASTAL COUNTIES WITH POPS INCREASING TO AROUND 30 PERCENT OVER THE INTERIOR THROUGH THE AFTERNOON/EARLY EVENING. STORM STEERING FLOW REMAINS LIGHT NORTHERLY. MID-LEVEL TEMPERATURES REMAIN WARM (700/500MB +10C/-5C RESPECTIVELY). WINDS WILL BECOME LIGHT AGAIN MON NIGHT. HIGHS FORECAST IN THE L90S ALONG THE COAST AND M90S INTO THE INTERIOR. OVERNIGHT LOWS WELL INTO THE 70S STILL. TUE-TUE NIGHT...UPPER TROUGHING DEEPENS OVER THE EASTERN CONUS AS UPPER RIDGING AMPLIFIES OVER THE DESERT SOUTHWEST/ROCKY MOUNTAINS. THIS WILL ALLOW FOR A MORE UNIFORM SWRLY FLOW IN THE MID/UPPER LEVELS TO BEGIN TO DEVELOP ACROSS THE FLORIDA PENINSULA. THE WEAK FRONTAL BOUNDARY TO THE NORTH REMAINS QUASI-STATIONARY ACROSS THE NORTH GULF/NORTH FLORIDA. LIGHT SW/WSW FLOW WILL BE FOUND OVER ECFL DURING THE MORNING/EARLY AFTERNOON WITH WINDS BACKING ESE/SE NEAR THE COAST WITH SEA BREEZE DEVELOPMENT. MID-LEVEL TEMPERATURES SLIGHTLY COOLER AT 500MB WITH STORM MOTION OUT OF THE W/NW AROUND 5 MPH. PRECIPITATION CHANCES INCREASE TO 40 PERCENT INTERIOR AND 20-30 PERCENT TOWARD THE EAST COAST. WED-SAT...UPPER TROUGHING PERSISTS INTO THE EXTENDED BUT DOES BEGIN TO WEAKEN LATE IN THE WEEK. THE AFOREMENTIONED WEAK SURFACE BOUNDARY TO THE NORTH REMAINS IN PLACE WITH DEEP LAYER MOISTURE POOLING ALONG/AHEAD OF IT. THE GFS BRINGS SOME DRIER AIR INTO THE AREA FROM THE NORTH ON THU INTO SAT BUT THIS WILL BE DEPENDENT ON THE FRONT TO THE NORTH EITHER MOVING FURTHER SOUTH/DISSIPATING ALTOGETHER. FOR NOW WITH THE SWRLY STORM MOTION THROUGH THE PERIOD BELIEVE HIGH END CHANCE TO LIKELY POPS APPROPRIATE FOR ALMOST EACH AFTERNOON/EARLY EVENING WITH THE EASTERN PENINSULA HAVING GREATEST CHANCES THROUGH THIS PERIOD. COOLER AIR ALOFT (500MB/-7C TO -8C) IS FORECAST. SOME SORT OF ECSB DEVELOPMENT IS FORECAST EACH DAY BUT INLAND MOVEMENT LIKELY SLOWED BY SWRLY FLOW OFF OF THE SURFACE. PRECIPITABLE WATER VALUES IN UPWARDS OF 2 INCHES ALONG AND SOUTH OF THE SURFACE BOUNDARY. && .AVIATION... LOCAL MVFR PRESENTLY ALONG THE COAST IN/NEAR SHOWERS...WILL BECOME MORE COMMON THROUGH SUNRISE. THERE IS A SLIGHT CHANCE FOR IFR IN SOME OF THE SHOWERS THAT MOVE ONSHORE. ONCE DAYTIME HEATING KICKS IN BY LATE MORNING...SCATTERED SHOWERS/ISOLATED STORMS WILL FORM JUST INLAND ALONG THE SEA BREEZE BOUNDARY. SOME OF THESE COULD AFFECT COASTAL TERMINALS. BY 18Z-20Z THE CONVECTION SHOULD SHIFT WELL INLAND...WITH INTERIOR TERMINALS HAVING A CHANCE FOR STORMS UNTIL 22-24Z. && .MARINE... TODAY-TONIGHT...EAST/NORTHEAST WINDS 5-10 KNOTS ARE FORECAST TO BECOME NORTHEAST 10 KNOTS BY THIS AFTERNOON AND EVEN 10-15 KNOTS OFFSHORE AS A SLIGHT SURGE OCCURS. SEAS WILL BE 2-3 FEET EXCEPT 3-4 FEET OFFSHORE AND PERIODS LOWERING TO 5-6 SECONDS WILL PRODUCE MORE CHOP THAN WE HAVE HAD RECENTLY. THE PRESSURE GRADIENT WILL WEAKEN OVERNIGHT WITH WINDS DROPPING TO 5-10 KNOTS. THERE WILL BE SOME MARINE SHOWERS AND A FEW STORMS...ESPECIALLY BUILDING SOUTHWARD TO THE WATERS AROUND CANAVERAL THIS MORNING. LATEST RADAR TRENDS AND MODEL OUTPUT SUGGEST THE SOUTHERN WATERS SHOULD HAVE MORE ISOLATED ACTIVITY. MON-THU...THE PRESSURE GRADIENT WILL REMAIN FAIRLY WEAK WITH WIND SPEEDS STILL FORECAST AOB 10 KTS ON AVERAGE. OVERNIGHT/MORNING WILL LIKELY SEE AN OFFSHORE WIND COMPONENT DEVELOP WITH AN ONSHORE BREEZE FORMING EACH AFTERNOON WITH SLOW PUSH INLAND. SHOWER/STORM CHANCES STILL FAIRLY ISOLD MON/TUE BUT BEGIN TO PICK UP WED INTO THE EXTENDED WITH OFFSHORE STEERING FLOW IN THE AFTERNOON/EVENING WED- THU. SEAS STILL AOB 3 FT BUT LOCALLY HIGHER INVOF OF SHOWERS/STORMS. BOATERS ON INLAND LAKES WILL AGAIN NEED TO KEEP AN EYE TO THE SKY IN THE AFTERNOON/EARLY EVENING FOR DEVELOPING/APPROACHING SHOWERS/STORMS AS PRECIPITATION CHANCES GO UP. && .PRELIMINARY POINT TEMPS/POPS... DAB 91 74 92 74 / 30 10 20 20 MCO 93 75 94 75 / 40 10 30 20 MLB 91 76 92 75 / 30 10 20 10 VRB 90 74 91 74 / 30 10 10 10 LEE 94 76 94 77 / 40 10 30 20 SFB 93 75 94 76 / 40 10 30 20 ORL 93 76 95 77 / 40 10 30 20 FPR 91 74 92 74 / 30 10 10 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1108 PM CDT SAT AUG 22 2015 .UPDATE... ISSUED AT 856 PM CDT SAT AUG 22 2015 THE BAND OF SHOWERS AND ISOLATED STORMS ACROSS EAST CENTRAL IL HAS DISSIPATED, WHILE A FEW SHOWERS LINGER CLOSER TO THE CENTER OF THE SHORTWAVE SOUTH OF HIGHWAY 50. THE MAIN CONCERN THE REST OF THE NIGHT WILL SHIFT TO THE APPROACHING COLD FRONT, THAT IS PROJECTED TO REACH OUR WESTERN COUNTIES LATER TONIGHT. THE LATEST HRRR AND RAP GUIDANCE SHOW A DIMINISHING TREND IN THE LINE OF STORMS AS THEY MOVE ACROSS ILLINOIS. THE TIMING OF THE FRONTS ARRIVAL LENDS CREDENCE TO THAT TREND, WITH LOW INSTABILITY AND WEAKENING SHEAR PROFILES EARLY SUNDAY MORNING. WE WILL KEEP THE PROGRESSION OF A BAND OF CHANCE POPS ACROSS OUR COUNTIES FROM WEST TO EAST LATE TONIGHT AND SUNDAY MORNING. CONFIDENCE IS LOWERING IN A SOLID LINE OF SHOWERS/STORMS, WITH A MORE BROKEN LINE LOOKING MORE LIKELY. THE DIURNAL SWING TONIGHT WILL BE TEMPERED BY INCREASING CLOUD COVER AHEAD OF THE STORMS, AND FROM CLOUDS ASSOCIATED WITH THE SHORTWAVE IN SOUTHERN IL. WILL KEEP LOWS IN THE MID-UPPER 60S, AS DEWPOINTS BEGIN TO CLIMB THROUGH THE 60S. MAIN UPDATE TONIGHT WAS TO THE WEATHER GRIDS THIS EVENING, AND TO INCREASE CLOUD COVER TONIGHT. OTHERWISE, THE FORECAST GRIDS LOOK REASONABLE FOR NOW. && .SHORT TERM...(TONIGHT) ISSUED AT 256 PM CDT SAT AUG 22 2015 A WEAKENING AREA OF SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST OF EFFINGHAM WERE AHEAD OF A SHORT WAVE TROF OVER CENTRAL MO/AR. THIS CONVECTION WILL CONTINUE TO WEAKEN AS IT TRACKS ENE INTO SOUTHEAST IL DURING REST OF THIS AFTERNOON AND EARLY EVENING BEFORE SUNSET. HIGHEST POPS WERE OVER SHELBY...EFFINGHAM AND CLAY COUNTIES. MOST OF CENTRAL IL SHOULD STAY DRY THROUGH THIS EVENING WITH PARTLY TO MOSTLY CLOUDY SKIES. A 997 MB LOW PRESSURE OVER EAST CENTRAL ND HAS A COLD FRONT EXTENDING INTO EASTERN SD/NEBRASKA AND NW KS. MODELS TAKE COLD FRONT EAST TOWARD THE IA/IL BORDER AND CENTRAL MO BY 12Z/7 AM SUNDAY. CHANCES OF SHOWERS AND THUNDERSTORMS INCREASE OVER IL RIVER VALLEY AFTER 06Z/1 AM TONIGHT AND REACH AS FAR EAST AS I-57 BY 12Z/SUNDAY WITH SLIGHT POPS IN EASTERN IL LATE TONIGHT. SPC KEEPS MARGINAL RISK OF SEVERE STORMS WEST OF CWA (FROM QUAD CITIES TO QUINCY WEST) TONIGHT. NUDGED LOWS UP A TAD OVERNIGHT INTO THE MID TO UPPER 60S DUE TO MORE CLOUD COVER AND SE WINDS. COOLEST LOWS IN THE LOWER 60S AROUND DANVILLE WHERE MET/MAV HAVE 62F. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 256 PM CDT SAT AUG 22 2015 THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS TO START THE DAY SUNDAY ACROSS CENTRAL AND SOUTHEAST ILLINOIS AS A COLD FRONT BEGINS TO PUSH INTO THE AREA FROM THE NORTHWEST. THE EARLY ARRIVAL OF THE FRONT, WHICH SHOULD EXIT THE FORECAST AREA INTO INDIANA DURING THE AFTERNOON EVEN IN THE SLOWER MODEL SOLUTIONS, WILL PRECLUDE SIGNIFICANT PRE FRONTAL INSTABILITY. GUIDANCE STILL SUGGESTS CAPE VALUES REACHING AROUND 2500 J/KG IN THE FAR EAST/SOUTHEAST PORTION OF THE FORECAST AREA, BUT CORRESPONDING BULK SHEAR VALUES ARE STILL RATHER WEAK AND TOP OUT AROUND 25 KTS. SO, DO NOT EXPECT MORE THAN SCATTERED SHOWERS/STORMS ACROSS THE FORECAST AREA AHEAD OF THE FRONT, WITH PRECIPITATION QUICKLY ENDING FROM WEST TO EAST DURING THE AFTERNOON AS THE FRONT SWEEPS THROUGH. THE UPPER LEVEL FLOW ACROSS THE AREA TRENDS NORTHWESTERLY BEHIND SUNDAY`S SYSTEM, ALBEIT MOSTLY NEUTRAL LOCALLY, AS UPPER RIDGING BUILDS THROUGH THE ROCKIES. THIS UPPER FLOW PATTERN IS ACCOMPANIED BY HIGH PRESSURE AT THE SURFACE MORE OFTEN THAN NOT, AND THESE FEATURES SHOULD HELP KEEP CONDITIONS QUIET AND SLIGHTLY COOLER THAN NORMAL. MODEL GUIDANCE NOT IN VERY GOOD AGREEMENT IN WHEN THE NEXT DISTURBANCE OF CONSEQUENCE WILL IMPACT THE AREA IN THIS FLOW REGIME, BUT IT DOES NOT APPEAR AS THOUGH IT WILL ARRIVE MUCH SOONER THAN NEXT SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1107 PM CDT SAT AUG 22 2015 A FEW SHOWERS PERSISTED EAST OF CMI LATE THIS EVENING, WITH DRY CONDITIONS EVERYWHERE ELSE ACROSS THE FORECAST AREA THE LAST COUPLE OF HOURS. THAT ACTIVITY SHOULD DISSIPATE AS IT MOVES INTO INDIANA. CLOUD HEIGHTS DIPPED TO MVFR AT BMI...WITH VFR LEVELS AT ALL OTHER TERMINAL SITES. UPSTREAM TRENDS SHOW VFR CONDITIONS SHOULD RETURN FOR SEVERAL HOURS BEFORE THE RAIN REACHES NEAR PIA TO SPI. THEN CLOUD HEIGHTS COULD DIP BACK TO MVFR AS THE LINE OF SHOWERS AND STORMS MOVE ACROSS THE AREA. AS THE COLD FRONT MOVES ACROSS ILLINOIS, A LINE OF SHOWERS/STORMS WILL AFFECT THE TERMINAL SITES WITHIN A GENERAL WINDOW OF 3-5 HOURS. NO SEVERE WEATHER IS EXPECTED, AS SHEAR VALUES REMAIN LOW, AND INSTABILITY MARGINAL. THE SPEED OF THE FRONT SHOULD PUT MOST OF THE PRECIP EAST OF THE TERMINAL SITES BEFORE PEAK AFTERNOON HEATING, ALSO REDUCING THE CHANCES OF PARTICULARLY STRONG STORMS NEAR THE TAF LOCATIONS. FORECAST SOUNDINGS SUPPORT RAPID CLEARING DEVELOPING SUNDAY AFTERNOON FROM WEST TO EAST, REACHING CMI BY 21Z. WINDS WILL START OUT SOUTHEAST AT LESS THAN 10KT, THEN BECOME SOUTH AHEAD OF THE LINE OF PRECIP. ONCE THE COLD FRONT PASSES SUNDAY MORNING, WINDS WILL BECOME W-NW AND INCREASE TO 10-15KT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHIMON SHORT TERM...07 LONG TERM...BAK AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
112 PM EDT SUN AUG 23 2015 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 344 AM EDT SUN AUG 23 2015 SCATTERED THUNDERSTORMS WILL ACCOMPANY A STRONG COLD FRONT LATER TODAY. THE FRONT WILL SHIFT EAST QUICKLY THIS EVENING...WITH HIGH PRESSURE REESTABLISHING OVER THE OHIO VALLEY. DRY AND PLEASANT WEATHER IS EXPECTED FOR THE ENTIRE WEEK AS THE HIGH REMAINS THE DOMINANT WEATHER FEATURE. && .NEAR TERM /REST OF TODAY/... ISSUED AT 936 AM EDT SUN AUG 23 2015 FOCUS FOR TODAY IS THE APPROACH OF A COLD FRONT FROM THE WEST LATER THIS AFTERNOON. SCATTERED CONVECTION WILL REFIRE ALONG THE FRONT AS IT MOVES THROUGH THE FORECAST AREA DURING THE AFTERNOON. THIN AXIS OF DEEPER MOISTURE WITH PRECIP WATER VALUES AROUND 1.50 INCHES WILL ADVECT INTO THE REGION IMMEDIATELY AHEAD OF THE BOUNDARY. THE DEEPER MOISTURE WILL COMBINE WITH PEAK MLCAPE VALUES AT 1000-1500 J/KG...LOW LEVEL CONVERGENCE AND BL SHEAR VALUES BRIEFLY PEAKING NEAR 30KTS AS THE PRIMARY CATALYSTS IN CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THERE ARE MITIGATING FACTORS IN PLAY THOUGH HOWEVER. DESPITE DIFFLUENCE ALOFT...STRONGER UPPER FORCING WILL REMAIN DISPLACED TO THE NORTH OF THE AREA IN CLOSER PROXIMITY TO THE UPPER LOW. MODEL SOUNDINGS FROM BOTH THE OP GFS AND THE RAP HINT AT A WEAK CAPPING INVERSION PRESENT NEAR 10KFT WITH LARGELY POOR LAPSE RATES WHICH WOULD LIMIT AVAILABLE INSTABILITY AND CONVECTIVE COVERAGE. NAM MODEL SOUNDINGS PRESENT LITTLE IN THE WAY OF CAPPING AND CONSEQUENTLY GREATER AVAILABLE INSTABILITY DURING THE AFTERNOON...BUT THIS SOLUTION IS NOT PREFERRED AS CLOSER ANALYSIS INDICATES THAT IT IS LIKELY OVERDOING BOTH SURFACE TEMPS AND DEWPOINTS LATER TODAY. TAKING ALL OF THIS INTO ACCOUNT...HAVE TRENDED TOWARDS A CONSENSUS SOLUTION LED BY THE HI RES SUITE OF THE HRRR...RAP AND WRF WHICH BRING A NARROW YET BROKEN CONVECTIVE LINE QUICKLY ACROSS THE FORECAST AREA PRIMARILY BETWEEN 18Z AND 00Z. HIGHEST POPS WILL BE EMPLOYED OVER THE NORTHEAST HALF OF THE FORECAST AREA WHERE INSTABILITY WILL BE GREATEST AND INTERACT WITH BEST SHEAR AND MOISTURE. STORMS ARE LIKELY TO DISRUPT OUTDOOR ACTIVITIES BRIEFLY...WITH GUSTY WINDS AND LIGHTNING...AND POSSIBLY HAIL. STRONGER CELLS WILL HAVE THE POTENTIAL FOR AN ISOLATED SEVERE RISK WITH DAMAGING WINDS AND LARGE HAIL...ESPECIALLY NORTH AND EAST OF THE INDY METRO. STORMS WILL END RAPIDLY WITH THE FRONTAL PASSAGE BY EARLY EVENING. TEMPS...MAVMOS GUIDANCE LOOKED REASONABLE FOR HIGHS CONSIDERING INCREASING CLOUDS AND STORMS FOR THE AFTERNOON. EXPECTING GENERALLY LOW TO MID 80S. && .SHORT TERM /|TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 344 AM EDT SUN AUG 23 2015 FORECAST CHALLENGES ARE MINOR THROUGH THE SHORT TERM...AS STRONG HIGH PRESSURE BUILDS IN WITH DRY...PLEASANT WEATHER THROUGH MIDWEEK. HELD ONTO A LOW CHANCE POPS OVER FAR EASTERN COUNTIES FOR A FEW HOURS THIS EVENING TO ACCOUNT FOR ANY LINGERING CONVECTION AS THE COLD FRONT SWEEPS OFF TO THE EAST. EXPECT THE ENTIRE FORECAST AREA WILL BE DRY BY 02-03Z AT THE LATEST. STRONG UPPER LOW BY LATE AUGUST STANDARDS WILL PINWHEEL SLOWLY THROUGH THE GREAT LAKES...MAINTAINING A BROAD TROUGH WITH COOL CYCLONIC FLOW OVER THE REGION THROUGH MIDWEEK. EXPECT PLENTY OF SUNSHINE BOTH MONDAY AND TUESDAY WITH DIURNAL AFTERNOON CU IN THE COLD ADVECTION REGIME. CU WILL DISSIPATE NEAR SUNSET BOTH DAYS...SETTING THE STAGE FOR MAINLY CLEAR SKIES AT NIGHT WITH COOL TEMPERATURES. ALL IN ALL...A VERY PLEASANT STRETCH OF WEATHER UPCOMING FOR MUCH OF THIS WEEK. TEMPS...UTILIZED A MOS BLEND FOR HIGHS MONDAY...THEN TRENDED TOWARDS WARMER MAVMOS GUIDANCE FOR TUESDAY. HIGHS WILL RUN ABOUT 5-10 DEGREES BELOW NORMAL BOTH DAYS IN THE 70S. SHOULD SEE A NICE RURAL- URBAN SPLIT IN OVERNIGHT TEMPS WITH POTENTIAL FOR NORMAL COOL SPOTS ACROSS THE FORECAST AREA TO FALL INTO THE 40S...ESPECIALLY EARLY TUESDAY MORNING. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... ISSUED AT 223 AM EDT SUN AUG 23 2015 GUIDANCE CONTINUES TO DEPICT A DRY AND COOL EXTENDED PORTION OF THE FORECAST...ALTHOUGH WITH SOME MODERATION OF TEMPERATURES BACK TOWARD NORMAL NEAR THE END OF THE PERIOD. MODELS NOW SHOW A STRONGER SURFACE RIDGE ACROSS THE AREA LATE IN THE WEEK...WHICH WOULD PREVENT FRONTAL ZONE FROM MAKING IT INTO THE AREA UNTIL AFTER THE SEVEN DAY FORECAST PERIOD. CAN GO WITH A DRY FORECAST THROUGHOUT THE EXTENDED. BLENDED INITIALIZATION HANDLED THIS WELL AND ONLY MINOR TWEAKS WERE REQUIRED. && .AVIATION /DISCUSSION FOR THE 23/1800Z TAF ISSUANCE/... ISSUED AT 112 PM EDT SUN AUG 23 2015 MVFR CEILING AT TIMES WITH SCATTERED SHOWERS OR THUNDERSTORMS THIS AFTERNOON. OTHERWISE...VFR FROM THIS EVENING ON. A COLD FRONT NEAR A CHICAGO TO SAINT LOUIS LINE WILL PUSH ACROSS OUR REGION LATER THIS AFTERNOON. SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL OCCUR ALONG AND AHEAD OF THIS FRONT. MOST PLACES WHEN VCTS OR VCSH AS ANY SHOWERS OR THUNDERSTORMS WILL BE BRIEF. WEATHER DEPICTION SHOWS SOME AREAS OF MVFR CEILINGS...BUT THIS SHOULD RISE TO NEAR OR ABOVE 3 THOUSAND FEET BY LATE AFTERNOON. CLEARING WILL OCCUR BEHIND COLD FRONT AND FROM MID TO LATE EVENING ON EXPECT VFR WITH MOSTLY CLEAR SKIES AS DRIER AIR SPREADS INTO OUR REGION. WINDS WILL BE FROM THE SOUTHWEST AHEAD OF THE FRONT UP TO 10 KNOTS AND GUSTS TO 18 KNOTS. LIGHT WEST OR NORTHWEST WINDS WILL BE THE RULE TONIGHT. WINDS MAY PICK UP A LITTLE BY MIDDAY MONDAY WITH SOME DAYTIME MIXING...BUT WIND SPEEDS WILL BE LESS THAN 15 KNOTS. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM...NIELD AVIATION...JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1030 AM EDT SUN AUG 23 2015 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 344 AM EDT SUN AUG 23 2015 SCATTERED THUNDERSTORMS WILL ACCOMPANY A STRONG COLD FRONT LATER TODAY. THE FRONT WILL SHIFT EAST QUICKLY THIS EVENING...WITH HIGH PRESSURE REESTABLISHING OVER THE OHIO VALLEY. DRY AND PLEASANT WEATHER IS EXPECTED FOR THE ENTIRE WEEK AS THE HIGH REMAINS THE DOMINANT WEATHER FEATURE. && .NEAR TERM /REST OF TODAY/... ISSUED AT 936 AM EDT SUN AUG 23 2015 FOCUS FOR TODAY IS THE APPROACH OF A COLD FRONT FROM THE WEST LATER THIS AFTERNOON. SCATTERED CONVECTION WILL REFIRE ALONG THE FRONT AS IT MOVES THROUGH THE FORECAST AREA DURING THE AFTERNOON. THIN AXIS OF DEEPER MOISTURE WITH PRECIP WATER VALUES AROUND 1.50 INCHES WILL ADVECT INTO THE REGION IMMEDIATELY AHEAD OF THE BOUNDARY. THE DEEPER MOISTURE WILL COMBINE WITH PEAK MLCAPE VALUES AT 1000-1500 J/KG...LOW LEVEL CONVERGENCE AND BL SHEAR VALUES BRIEFLY PEAKING NEAR 30KTS AS THE PRIMARY CATALYSTS IN CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THERE ARE MITIGATING FACTORS IN PLAY THOUGH HOWEVER. DESPITE DIFFLUENCE ALOFT...STRONGER UPPER FORCING WILL REMAIN DISPLACED TO THE NORTH OF THE AREA IN CLOSER PROXIMITY TO THE UPPER LOW. MODEL SOUNDINGS FROM BOTH THE OP GFS AND THE RAP HINT AT A WEAK CAPPING INVERSION PRESENT NEAR 10KFT WITH LARGELY POOR LAPSE RATES WHICH WOULD LIMIT AVAILABLE INSTABILITY AND CONVECTIVE COVERAGE. NAM MODEL SOUNDINGS PRESENT LITTLE IN THE WAY OF CAPPING AND CONSEQUENTLY GREATER AVAILABLE INSTABILITY DURING THE AFTERNOON...BUT THIS SOLUTION IS NOT PREFERRED AS CLOSER ANALYSIS INDICATES THAT IT IS LIKELY OVERDOING BOTH SURFACE TEMPS AND DEWPOINTS LATER TODAY. TAKING ALL OF THIS INTO ACCOUNT...HAVE TRENDED TOWARDS A CONSENSUS SOLUTION LED BY THE HI RES SUITE OF THE HRRR...RAP AND WRF WHICH BRING A NARROW YET BROKEN CONVECTIVE LINE QUICKLY ACROSS THE FORECAST AREA PRIMARILY BETWEEN 18Z AND 00Z. HIGHEST POPS WILL BE EMPLOYED OVER THE NORTHEAST HALF OF THE FORECAST AREA WHERE INSTABILITY WILL BE GREATEST AND INTERACT WITH BEST SHEAR AND MOISTURE. STORMS ARE LIKELY TO DISRUPT OUTDOOR ACTIVITIES BRIEFLY...WITH GUSTY WINDS AND LIGHTNING...AND POSSIBLY HAIL. STRONGER CELLS WILL HAVE THE POTENTIAL FOR AN ISOLATED SEVERE RISK WITH DAMAGING WINDS AND LARGE HAIL...ESPECIALLY NORTH AND EAST OF THE INDY METRO. STORMS WILL END RAPIDLY WITH THE FRONTAL PASSAGE BY EARLY EVENING. TEMPS...MAVMOS GUIDANCE LOOKED REASONABLE FOR HIGHS CONSIDERING INCREASING CLOUDS AND STORMS FOR THE AFTERNOON. EXPECTING GENERALLY LOW TO MID 80S. && .SHORT TERM /|TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 344 AM EDT SUN AUG 23 2015 FORECAST CHALLENGES ARE MINOR THROUGH THE SHORT TERM...AS STRONG HIGH PRESSURE BUILDS IN WITH DRY...PLEASANT WEATHER THROUGH MIDWEEK. HELD ONTO A LOW CHANCE POPS OVER FAR EASTERN COUNTIES FOR A FEW HOURS THIS EVENING TO ACCOUNT FOR ANY LINGERING CONVECTION AS THE COLD FRONT SWEEPS OFF TO THE EAST. EXPECT THE ENTIRE FORECAST AREA WILL BE DRY BY 02-03Z AT THE LATEST. STRONG UPPER LOW BY LATE AUGUST STANDARDS WILL PINWHEEL SLOWLY THROUGH THE GREAT LAKES...MAINTAINING A BROAD TROUGH WITH COOL CYCLONIC FLOW OVER THE REGION THROUGH MIDWEEK. EXPECT PLENTY OF SUNSHINE BOTH MONDAY AND TUESDAY WITH DIURNAL AFTERNOON CU IN THE COLD ADVECTION REGIME. CU WILL DISSIPATE NEAR SUNSET BOTH DAYS...SETTING THE STAGE FOR MAINLY CLEAR SKIES AT NIGHT WITH COOL TEMPERATURES. ALL IN ALL...A VERY PLEASANT STRETCH OF WEATHER UPCOMING FOR MUCH OF THIS WEEK. TEMPS...UTILIZED A MOS BLEND FOR HIGHS MONDAY...THEN TRENDED TOWARDS WARMER MAVMOS GUIDANCE FOR TUESDAY. HIGHS WILL RUN ABOUT 5-10 DEGREES BELOW NORMAL BOTH DAYS IN THE 70S. SHOULD SEE A NICE RURAL- URBAN SPLIT IN OVERNIGHT TEMPS WITH POTENTIAL FOR NORMAL COOL SPOTS ACROSS THE FORECAST AREA TO FALL INTO THE 40S...ESPECIALLY EARLY TUESDAY MORNING. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... ISSUED AT 223 AM EDT SUN AUG 23 2015 GUIDANCE CONTINUES TO DEPICT A DRY AND COOL EXTENDED PORTION OF THE FORECAST...ALTHOUGH WITH SOME MODERATION OF TEMPERATURES BACK TOWARD NORMAL NEAR THE END OF THE PERIOD. MODELS NOW SHOW A STRONGER SURFACE RIDGE ACROSS THE AREA LATE IN THE WEEK...WHICH WOULD PREVENT FRONTAL ZONE FROM MAKING IT INTO THE AREA UNTIL AFTER THE SEVEN DAY FORECAST PERIOD. CAN GO WITH A DRY FORECAST THROUGHOUT THE EXTENDED. BLENDED INITIALIZATION HANDLED THIS WELL AND ONLY MINOR TWEAKS WERE REQUIRED. && .AVIATION /DISCUSSION FOR THE 23/15Z KIND TAF UPDATE/... ISSUED AT 1030 AM EDT SUN AUG 23 2015 MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS. NO OTHER CHANGES ARE NEEDED AT THIS TIME. PREVIOUS AVIATION DUSCUSSION FOLLOWS... MAINLY VFR THROUGH THE PERIOD...ALTHOUGH MVFR OR WORSE COULD BRIEFLY DEVELOP IN SHOWERS OR STORMS. COLD FRONT WILL SWEEP ACROSS THE AREA LATER TODAY...AND SCATTERED SHOWERS AND STORMS MAY DEVELOP ALONG IT. FOR NOW HAVE INSERTED VCSH MENTION AND WILL ALLOW LATER PACKAGES TO REFINE AS DETAILS EMERGE. BEST CHANCE FOR STORMS WOULD LIKELY BE IN 18-00Z TIME FRAME. WINDS MAY GUST TO NEAR 20KT AT TIMES TODAY OUT OF THE SOUTHWEST. OTHERWISE WINDS WILL BECOME LIGHT AND NORTHWESTERLY IN THE WAKE OF THE FRONT THIS EVENING. NO SIGNIFICANT OBSTRUCTIONS TO VISIBILITY OUTSIDE OF STORMS ANTICIPATED DURING THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM...NIELD AVIATION...NIELD/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
953 AM EDT SUN AUG 23 2015 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 344 AM EDT SUN AUG 23 2015 SCATTERED THUNDERSTORMS WILL ACCOMPANY A STRONG COLD FRONT LATER TODAY. THE FRONT WILL SHIFT EAST QUICKLY THIS EVENING...WITH HIGH PRESSURE REESTABLISHING OVER THE OHIO VALLEY. DRY AND PLEASANT WEATHER IS EXPECTED FOR THE ENTIRE WEEK AS THE HIGH REMAINS THE DOMINANT WEATHER FEATURE. && .NEAR TERM /REST OF TODAY/... ISSUED AT 936 AM EDT SUN AUG 23 2015 FOCUS FOR TODAY IS THE APPROACH OF A COLD FRONT FROM THE WEST LATER THIS AFTERNOON. SCATTERED CONVECTION WILL REFIRE ALONG THE FRONT AS IT MOVES THROUGH THE FORECAST AREA DURING THE AFTERNOON. THIN AXIS OF DEEPER MOISTURE WITH PRECIP WATER VALUES AROUND 1.50 INCHES WILL ADVECT INTO THE REGION IMMEDIATELY AHEAD OF THE BOUNDARY. THE DEEPER MOISTURE WILL COMBINE WITH PEAK MLCAPE VALUES AT 1000-1500 J/KG...LOW LEVEL CONVERGENCE AND BL SHEAR VALUES BRIEFLY PEAKING NEAR 30KTS AS THE PRIMARY CATALYSTS IN CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THERE ARE MITIGATING FACTORS IN PLAY THOUGH HOWEVER. DESPITE DIFFLUENCE ALOFT...STRONGER UPPER FORCING WILL REMAIN DISPLACED TO THE NORTH OF THE AREA IN CLOSER PROXIMITY TO THE UPPER LOW. MODEL SOUNDINGS FROM BOTH THE OP GFS AND THE RAP HINT AT A WEAK CAPPING INVERSION PRESENT NEAR 10KFT WITH LARGELY POOR LAPSE RATES WHICH WOULD LIMIT AVAILABLE INSTABILITY AND CONVECTIVE COVERAGE. NAM MODEL SOUNDINGS PRESENT LITTLE IN THE WAY OF CAPPING AND CONSEQUENTLY GREATER AVAILABLE INSTABILITY DURING THE AFTERNOON...BUT THIS SOLUTION IS NOT PREFERRED AS CLOSER ANALYSIS INDICATES THAT IT IS LIKELY OVERDOING BOTH SURFACE TEMPS AND DEWPOINTS LATER TODAY. TAKING ALL OF THIS INTO ACCOUNT...HAVE TRENDED TOWARDS A CONSENSUS SOLUTION LED BY THE HI RES SUITE OF THE HRRR...RAP AND WRF WHICH BRING A NARROW YET BROKEN CONVECTIVE LINE QUICKLY ACROSS THE FORECAST AREA PRIMARILY BETWEEN 18Z AND 00Z. HIGHEST POPS WILL BE EMPLOYED OVER THE NORTHEAST HALF OF THE FORECAST AREA WHERE INSTABILITY WILL BE GREATEST AND INTERACT WITH BEST SHEAR AND MOISTURE. STORMS ARE LIKELY TO DISRUPT OUTDOOR ACTIVITIES BRIEFLY...WITH GUSTY WINDS AND LIGHTNING...AND POSSIBLY HAIL. STRONGER CELLS WILL HAVE THE POTENTIAL FOR AN ISOLATED SEVERE RISK WITH DAMAGING WINDS AND LARGE HAIL...ESPECIALLY NORTH AND EAST OF THE INDY METRO. STORMS WILL END RAPIDLY WITH THE FRONTAL PASSAGE BY EARLY EVENING. TEMPS...MAVMOS GUIDANCE LOOKED REASONABLE FOR HIGHS CONSIDERING INCREASING CLOUDS AND STORMS FOR THE AFTERNOON. EXPECTING GENERALLY LOW TO MID 80S. && .SHORT TERM /|TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 344 AM EDT SUN AUG 23 2015 FORECAST CHALLENGES ARE MINOR THROUGH THE SHORT TERM...AS STRONG HIGH PRESSURE BUILDS IN WITH DRY...PLEASANT WEATHER THROUGH MIDWEEK. HELD ONTO A LOW CHANCE POPS OVER FAR EASTERN COUNTIES FOR A FEW HOURS THIS EVENING TO ACCOUNT FOR ANY LINGERING CONVECTION AS THE COLD FRONT SWEEPS OFF TO THE EAST. EXPECT THE ENTIRE FORECAST AREA WILL BE DRY BY 02-03Z AT THE LATEST. STRONG UPPER LOW BY LATE AUGUST STANDARDS WILL PINWHEEL SLOWLY THROUGH THE GREAT LAKES...MAINTAINING A BROAD TROUGH WITH COOL CYCLONIC FLOW OVER THE REGION THROUGH MIDWEEK. EXPECT PLENTY OF SUNSHINE BOTH MONDAY AND TUESDAY WITH DIURNAL AFTERNOON CU IN THE COLD ADVECTION REGIME. CU WILL DISSIPATE NEAR SUNSET BOTH DAYS...SETTING THE STAGE FOR MAINLY CLEAR SKIES AT NIGHT WITH COOL TEMPERATURES. ALL IN ALL...A VERY PLEASANT STRETCH OF WEATHER UPCOMING FOR MUCH OF THIS WEEK. TEMPS...UTILIZED A MOS BLEND FOR HIGHS MONDAY...THEN TRENDED TOWARDS WARMER MAVMOS GUIDANCE FOR TUESDAY. HIGHS WILL RUN ABOUT 5-10 DEGREES BELOW NORMAL BOTH DAYS IN THE 70S. SHOULD SEE A NICE RURAL- URBAN SPLIT IN OVERNIGHT TEMPS WITH POTENTIAL FOR NORMAL COOL SPOTS ACROSS THE FORECAST AREA TO FALL INTO THE 40S...ESPECIALLY EARLY TUESDAY MORNING. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... ISSUED AT 223 AM EDT SUN AUG 23 2015 GUIDANCE CONTINUES TO DEPICT A DRY AND COOL EXTENDED PORTION OF THE FORECAST...ALTHOUGH WITH SOME MODERATION OF TEMPERATURES BACK TOWARD NORMAL NEAR THE END OF THE PERIOD. MODELS NOW SHOW A STRONGER SURFACE RIDGE ACROSS THE AREA LATE IN THE WEEK...WHICH WOULD PREVENT FRONTAL ZONE FROM MAKING IT INTO THE AREA UNTIL AFTER THE SEVEN DAY FORECAST PERIOD. CAN GO WITH A DRY FORECAST THROUGHOUT THE EXTENDED. BLENDED INITIALIZATION HANDLED THIS WELL AND ONLY MINOR TWEAKS WERE REQUIRED. && .AVIATION /DISCUSSION FOR THE 23/12Z TAFS/... ISSUED AT 713 AM EDT SUN AUG 23 2015 MAINLY VFR THROUGH THE PERIOD...ALTHOUGH MVFR OR WORSE COULD BRIEFLY DEVELOP IN SHOWERS OR STORMS. COLD FRONT WILL SWEEP ACROSS THE AREA LATER TODAY...AND SCATTERED SHOWERS AND STORMS MAY DEVELOP ALONG IT. FOR NOW HAVE INSERTED VCSH MENTION AND WILL ALLOW LATER PACKAGES TO REFINE AS DETAILS EMERGE. BEST CHANCE FOR STORMS WOULD LIKELY BE IN 18-00Z TIME FRAME. WINDS MAY GUST TO NEAR 20KT AT TIMES TODAY OUT OF THE SOUTHWEST. OTHERWISE WINDS WILL BECOME LIGHT AND NORTHWESTERLY IN THE WAKE OF THE FRONT THIS EVENING. NO SIGNIFICANT OBSTRUCTIONS TO VISIBILITY OUTSIDE OF STORMS ANTICIPATED DURING THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...SMF/RYAN SHORT TERM...RYAN LONG TERM...NIELD AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
713 AM EDT SUN AUG 23 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 344 AM EDT SUN AUG 23 2015 SCATTERED THUNDERSTORMS WILL ACCOMPANY A STRONG COLD FRONT LATER TODAY. THE FRONT WILL SHIFT EAST QUICKLY THIS EVENING...WITH HIGH PRESSURE REESTABLISHING OVER THE OHIO VALLEY. DRY AND PLEASANT WEATHER IS EXPECTED FOR THE ENTIRE WEEK AS THE HIGH REMAINS THE DOMINANT WEATHER FEATURE. && .NEAR TERM /TODAY/... ISSUED AT 344 AM EDT SUN AUG 23 2015 ISOLATED SHOWERS HAVE DEVELOPED ACROSS THE WESTERN HALF OF THE FORECAST AREA EARLY THIS MORNING AS A WEAK UPPER WAVE MOVES ACROSS THE REGION. THE INCREASED CLOUD COVER ASSOCIATED WITH THE WAVE ALOFT WAS KEEPING TEMPS WARMER THIS MORNING. 07Z TEMPS WERE LARGELY IN THE 60S. THE INITIAL UPPER WAVE ACROSS THE AREA WILL SHIFT EAST PRIOR TO DAYBREAK. COULD SEE ISOLATED SHOWERS OVER THE NEXT 2-3 HOURS BEFORE AXIS OF DRIER AIR IMMEDIATELY BEHIND THE WAVE NOTED OFF WATER VAPOR IMAGERY MOVES IN FROM THE WEST. SHOULD ALSO SEE A DECREASE IN CLOUDS TOWARDS DAYBREAK WITH THE ARRIVAL OF THE DRIER AIR AS WELL. THE FOCUS THEN TURNS TO THE APPROACH OF A COLD FRONT FROM THE WEST LATER TODAY. CONVECTION ALONG THE BOUNDARY IS STEADILY WEAKENING EARLY THIS MORNING OVER IOWA AND NORTHERN MISSOURI AND SHOULD CONTINUE TO DO SO THROUGH SUNRISE AS THE STORMS MOVE INTO A LESS FAVORABLE AIRMASS. MID AND HIGH LEVEL REMNANT CLOUD DEBRIS FROM STORMS OVER THE MID MISSISSIPPI VALLEY WILL DRIFT INTO THE REGION AFTER DAYBREAK...BUT EXPECT MOST AREAS WILL REMAIN DRY THROUGH MIDDAY. SCATTERED CONVECTION WILL REFIRE ALONG THE FRONT AS IT MOVES THROUGH THE FORECAST AREA DURING THE AFTERNOON. THIN AXIS OF DEEPER MOISTURE WITH PRECIP WATER VALUES AROUND 1.50 INCHES WILL ADVECT INTO THE REGION IMMEDIATELY AHEAD OF THE BOUNDARY. THE DEEPER MOISTURE WILL COMBINE WITH PEAK MLCAPE VALUES AT 1000-1500 J/KG...LOW LEVEL CONVERGENCE AND BL SHEAR VALUES BRIEFLY PEAKING NEAR 30KTS AS THE PRIMARY CATALYSTS IN CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THERE ARE MITIGATING FACTORS IN PLAY THOUGH HOWEVER. DESPITE DIFFLUENCE ALOFT...STRONGER UPPER FORCING WILL REMAIN DISPLACED TO THE NORTH OF THE AREA IN CLOSER PROXIMITY TO THE UPPER LOW. MODEL SOUNDINGS FROM BOTH THE OP GFS AND THE RAP HINT AT A WEAK CAPPING INVERSION PRESENT NEAR 10KFT WITH LARGELY POOR LAPSE RATES WHICH WOULD LIMIT AVAILABLE INSTABILITY AND CONVECTIVE COVERAGE. NAM MODEL SOUNDINGS PRESENT LITTLE IN THE WAY OF CAPPING AND CONSEQUENTLY GREATER AVAILABLE INSTABILITY DURING THE AFTERNOON...BUT THIS SOLUTION IS NOT PREFERRED AS CLOSER ANALYSIS INDICATES THAT IT IS LIKELY OVERDOING BOTH SURFACE TEMPS AND DEWPOINTS LATER TODAY. TAKING ALL OF THIS INTO ACCOUNT...HAVE TRENDED TOWARDS A CONSENSUS SOLUTION LED BY THE HI RES SUITE OF THE HRRR...RAP AND WRF WHICH BRING A NARROW YET BROKEN CONVECTIVE LINE QUICKLY ACROSS THE FORECAST AREA PRIMARILY BETWEEN 18Z AND 00Z. HIGHEST POPS WILL BE EMPLOYED OVER THE NORTHEAST HALF OF THE FORECAST AREA WHERE INSTABILITY WILL BE GREATEST AND INTERACT WITH BEST SHEAR AND MOISTURE. STORMS ARE LIKELY TO DISRUPT OUTDOOR ACTIVITIES BRIEFLY...WITH GUSTY WINDS AND LIGHTNING...AND POSSIBLY HAIL. STRONGER CELLS WILL HAVE THE POTENTIAL FOR AN ISOLATED SEVERE RISK WITH DAMAGING WINDS AND LARGE HAIL...ESPECIALLY NORTH AND EAST OF THE INDY METRO. STORMS WILL END RAPIDLY WITH THE FRONTAL PASSAGE BY EARLY EVENING. TEMPS...MAVMOS GUIDANCE LOOKED REASONABLE FOR HIGHS CONSIDERING INCREASING CLOUDS AND STORMS FOR THE AFTERNOON. EXPECTING GENERALLY LOW TO MID 80S. && .SHORT TERM /|TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 344 AM EDT SUN AUG 23 2015 FORECAST CHALLENGES ARE MINOR THROUGH THE SHORT TERM...AS STRONG HIGH PRESSURE BUILDS IN WITH DRY...PLEASANT WEATHER THROUGH MIDWEEK. HELD ONTO A LOW CHANCE POPS OVER FAR EASTERN COUNTIES FOR A FEW HOURS THIS EVENING TO ACCOUNT FOR ANY LINGERING CONVECTION AS THE COLD FRONT SWEEPS OFF TO THE EAST. EXPECT THE ENTIRE FORECAST AREA WILL BE DRY BY 02-03Z AT THE LATEST. STRONG UPPER LOW BY LATE AUGUST STANDARDS WILL PINWHEEL SLOWLY THROUGH THE GREAT LAKES...MAINTAINING A BROAD TROUGH WITH COOL CYCLONIC FLOW OVER THE REGION THROUGH MIDWEEK. EXPECT PLENTY OF SUNSHINE BOTH MONDAY AND TUESDAY WITH DIURNAL AFTERNOON CU IN THE COLD ADVECTION REGIME. CU WILL DISSIPATE NEAR SUNSET BOTH DAYS...SETTING THE STAGE FOR MAINLY CLEAR SKIES AT NIGHT WITH COOL TEMPERATURES. ALL IN ALL...A VERY PLEASANT STRETCH OF WEATHER UPCOMING FOR MUCH OF THIS WEEK. TEMPS...UTILIZED A MOS BLEND FOR HIGHS MONDAY...THEN TRENDED TOWARDS WARMER MAVMOS GUIDANCE FOR TUESDAY. HIGHS WILL RUN ABOUT 5-10 DEGREES BELOW NORMAL BOTH DAYS IN THE 70S. SHOULD SEE A NICE RURAL- URBAN SPLIT IN OVERNIGHT TEMPS WITH POTENTIAL FOR NORMAL COOL SPOTS ACROSS THE FORECAST AREA TO FALL INTO THE 40S...ESPECIALLY EARLY TUESDAY MORNING. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... ISSUED AT 223 AM EDT SUN AUG 23 2015 GUIDANCE CONTINUES TO DEPICT A DRY AND COOL EXTENDED PORTION OF THE FORECAST...ALTHOUGH WITH SOME MODERATION OF TEMPERATURES BACK TOWARD NORMAL NEAR THE END OF THE PERIOD. MODELS NOW SHOW A STRONGER SURFACE RIDGE ACROSS THE AREA LATE IN THE WEEK...WHICH WOULD PREVENT FRONTAL ZONE FROM MAKING IT INTO THE AREA UNTIL AFTER THE SEVEN DAY FORECAST PERIOD. CAN GO WITH A DRY FORECAST THROUGHOUT THE EXTENDED. BLENDED INITIALIZATION HANDLED THIS WELL AND ONLY MINOR TWEAKS WERE REQUIRED. && .AVIATION /DISCUSSION FOR THE 23/12Z TAFS/... ISSUED AT 713 AM EDT SUN AUG 23 2015 MAINLY VFR THROUGH THE PERIOD...ALTHOUGH MVFR OR WORSE COULD BRIEFLY DEVELOP IN SHOWERS OR STORMS. COLD FRONT WILL SWEEP ACROSS THE AREA LATER TODAY...AND SCATTERED SHOWERS AND STORMS MAY DEVELOP ALONG IT. FOR NOW HAVE INSERTED VCSH MENTION AND WILL ALLOW LATER PACKAGES TO REFINE AS DETAILS EMERGE. BEST CHANCE FOR STORMS WOULD LIKELY BE IN 18-00Z TIME FRAME. WINDS MAY GUST TO NEAR 20KT AT TIMES TODAY OUT OF THE SOUTHWEST. OTHERWISE WINDS WILL BECOME LIGHT AND NORTHWESTERLY IN THE WAKE OF THE FRONT THIS EVENING. NO SIGNIFICANT OBSTRUCTIONS TO VISIBILITY OUTSIDE OF STORMS ANTICIPATED DURING THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...NIELD AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
344 AM EDT SUN AUG 23 2015 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 344 AM EDT SUN AUG 23 2015 SCATTERED THUNDERSTORMS WILL ACCOMPANY A STRONG COLD FRONT LATER TODAY. THE FRONT WILL SHIFT EAST QUICKLY THIS EVENING...WITH HIGH PRESSURE REESTABLISHING OVER THE OHIO VALLEY. DRY AND PLEASANT WEATHER IS EXPECTED FOR THE ENTIRE WEEK AS THE HIGH REMAINS THE DOMINANT WEATHER FEATURE. && .NEAR TERM /TODAY/... ISSUED AT 344 AM EDT SUN AUG 23 2015 ISOLATED SHOWERS HAVE DEVELOPED ACROSS THE WESTERN HALF OF THE FORECAST AREA EARLY THIS MORNING AS A WEAK UPPER WAVE MOVES ACROSS THE REGION. THE INCREASED CLOUD COVER ASSOCIATED WITH THE WAVE ALOFT WAS KEEPING TEMPS WARMER THIS MORNING. 07Z TEMPS WERE LARGELY IN THE 60S. THE INITIAL UPPER WAVE ACROSS THE AREA WILL SHIFT EAST PRIOR TO DAYBREAK. COULD SEE ISOLATED SHOWERS OVER THE NEXT 2-3 HOURS BEFORE AXIS OF DRIER AIR IMMEDIATELY BEHIND THE WAVE NOTED OFF WATER VAPOR IMAGERY MOVES IN FROM THE WEST. SHOULD ALSO SEE A DECREASE IN CLOUDS TOWARDS DAYBREAK WITH THE ARRIVAL OF THE DRIER AIR AS WELL. THE FOCUS THEN TURNS TO THE APPROACH OF A COLD FRONT FROM THE WEST LATER TODAY. CONVECTION ALONG THE BOUNDARY IS STEADILY WEAKENING EARLY THIS MORNING OVER IOWA AND NORTHERN MISSOURI AND SHOULD CONTINUE TO DO SO THROUGH SUNRISE AS THE STORMS MOVE INTO A LESS FAVORABLE AIRMASS. MID AND HIGH LEVEL REMNANT CLOUD DEBRIS FROM STORMS OVER THE MID MISSISSIPPI VALLEY WILL DRIFT INTO THE REGION AFTER DAYBREAK...BUT EXPECT MOST AREAS WILL REMAIN DRY THROUGH MIDDAY. SCATTERED CONVECTION WILL REFIRE ALONG THE FRONT AS IT MOVES THROUGH THE FORECAST AREA DURING THE AFTERNOON. THIN AXIS OF DEEPER MOISTURE WITH PRECIP WATER VALUES AROUND 1.50 INCHES WILL ADVECT INTO THE REGION IMMEDIATELY AHEAD OF THE BOUNDARY. THE DEEPER MOISTURE WILL COMBINE WITH PEAK MLCAPE VALUES AT 1000-1500 J/KG...LOW LEVEL CONVERGENCE AND BL SHEAR VALUES BRIEFLY PEAKING NEAR 30KTS AS THE PRIMARY CATALYSTS IN CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THERE ARE MITIGATING FACTORS IN PLAY THOUGH HOWEVER. DESPITE DIFFLUENCE ALOFT...STRONGER UPPER FORCING WILL REMAIN DISPLACED TO THE NORTH OF THE AREA IN CLOSER PROXIMITY TO THE UPPER LOW. MODEL SOUNDINGS FROM BOTH THE OP GFS AND THE RAP HINT AT A WEAK CAPPING INVERSION PRESENT NEAR 10KFT WITH LARGELY POOR LAPSE RATES WHICH WOULD LIMIT AVAILABLE INSTABILITY AND CONVECTIVE COVERAGE. NAM MODEL SOUNDINGS PRESENT LITTLE IN THE WAY OF CAPPING AND CONSEQUENTLY GREATER AVAILABLE INSTABILITY DURING THE AFTERNOON...BUT THIS SOLUTION IS NOT PREFERRED AS CLOSER ANALYSIS INDICATES THAT IT IS LIKELY OVERDOING BOTH SURFACE TEMPS AND DEWPOINTS LATER TODAY. TAKING ALL OF THIS INTO ACCOUNT...HAVE TRENDED TOWARDS A CONSENSUS SOLUTION LED BY THE HI RES SUITE OF THE HRRR...RAP AND WRF WHICH BRING A NARROW YET BROKEN CONVECTIVE LINE QUICKLY ACROSS THE FORECAST AREA PRIMARILY BETWEEN 18Z AND 00Z. HIGHEST POPS WILL BE EMPLOYED OVER THE NORTHEAST HALF OF THE FORECAST AREA WHERE INSTABILITY WILL BE GREATEST AND INTERACT WITH BEST SHEAR AND MOISTURE. STORMS ARE LIKELY TO DISRUPT OUTDOOR ACTIVITIES BRIEFLY...WITH GUSTY WINDS AND LIGHTNING...AND POSSIBLY HAIL. STRONGER CELLS WILL HAVE THE POTENTIAL FOR AN ISOLATED SEVERE RISK WITH DAMAGING WINDS AND LARGE HAIL...ESPECIALLY NORTH AND EAST OF THE INDY METRO. STORMS WILL END RAPIDLY WITH THE FRONTAL PASSAGE BY EARLY EVENING. TEMPS...MAVMOS GUIDANCE LOOKED REASONABLE FOR HIGHS CONSIDERING INCREASING CLOUDS AND STORMS FOR THE AFTERNOON. EXPECTING GENERALLY LOW TO MID 80S. && .SHORT TERM /|TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 344 AM EDT SUN AUG 23 2015 FORECAST CHALLENGES ARE MINOR THROUGH THE SHORT TERM...AS STRONG HIGH PRESSURE BUILDS IN WITH DRY...PLEASANT WEATHER THROUGH MIDWEEK. HELD ONTO A LOW CHANCE POPS OVER FAR EASTERN COUNTIES FOR A FEW HOURS THIS EVENING TO ACCOUNT FOR ANY LINGERING CONVECTION AS THE COLD FRONT SWEEPS OFF TO THE EAST. EXPECT THE ENTIRE FORECAST AREA WILL BE DRY BY 02-03Z AT THE LATEST. STRONG UPPER LOW BY LATE AUGUST STANDARDS WILL PINWHEEL SLOWLY THROUGH THE GREAT LAKES...MAINTAINING A BROAD TROUGH WITH COOL CYCLONIC FLOW OVER THE REGION THROUGH MIDWEEK. EXPECT PLENTY OF SUNSHINE BOTH MONDAY AND TUESDAY WITH DIURNAL AFTERNOON CU IN THE COLD ADVECTION REGIME. CU WILL DISSIPATE NEAR SUNSET BOTH DAYS...SETTING THE STAGE FOR MAINLY CLEAR SKIES AT NIGHT WITH COOL TEMPERATURES. ALL IN ALL...A VERY PLEASANT STRETCH OF WEATHER UPCOMING FOR MUCH OF THIS WEEK. TEMPS...UTILIZED A MOS BLEND FOR HIGHS MONDAY...THEN TRENDED TOWARDS WARMER MAVMOS GUIDANCE FOR TUESDAY. HIGHS WILL RUN ABOUT 5-10 DEGREES BELOW NORMAL BOTH DAYS IN THE 70S. SHOULD SEE A NICE RURAL- URBAN SPLIT IN OVERNIGHT TEMPS WITH POTENTIAL FOR NORMAL COOL SPOTS ACROSS THE FORECAST AREA TO FALL INTO THE 40S...ESPECIALLY EARLY TUESDAY MORNING. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... ISSUED AT 223 AM EDT SUN AUG 23 2015 GUIDANCE CONTINUES TO DEPICT A DRY AND COOL EXTENDED PORTION OF THE FORECAST...ALTHOUGH WITH SOME MODERATION OF TEMPERATURES BACK TOWARD NORMAL NEAR THE END OF THE PERIOD. MODELS NOW SHOW A STRONGER SURFACE RIDGE ACROSS THE AREA LATE IN THE WEEK...WHICH WOULD PREVENT FRONTAL ZONE FROM MAKING IT INTO THE AREA UNTIL AFTER THE SEVEN DAY FORECAST PERIOD. CAN GO WITH A DRY FORECAST THROUGHOUT THE EXTENDED. BLENDED INITIALIZATION HANDLED THIS WELL AND ONLY MINOR TWEAKS WERE REQUIRED. && .AVIATION /DISCUSSION FOR THE 23/06Z TAFS/... ISSUED AT 1230 AM EDT SUN AUG 23 2015 SOME SCATTERED CLOUD COVER AROUND 050 EXPECTED OVERNIGHT...WITH LAYERED CLOUD ABOVE THAT LEVEL. LIFT...MOISTURE ADVECTION...AND HEATING AFTER SUNRISE ON SUNDAY SHOULD ALLOW FOR THE DEVELOPMENT OF CEILINGS IN THE 030-050 RANGE BY MID TO LATE MORNING SUNDAY. POTENTIAL EXISTS FOR SCATTERED CONVECTION TOWARDS/AFTER 231800Z AS A COLD FRONT APPROACHES THE AREA. LIGHT SURFACE WINDS OVERNIGHT WILL BECOME 200-230 DEGREES AT 8-12 KTS BY MIDDAY SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...NIELD AVIATION...JAS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
137 AM EDT SUN AUG 23 2015 .SYNOPSIS... ISSUED AT 331 PM EDT SAT AUG 22 2015 DRY CONDITIONS WILL PREVAIL INTO EARLY SUNDAY AS HIGH PRESSURE MOVES EAST OF THE REGION. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO ACCOMPANY A COLD FRONT AS IT SWEEPS ACROSS THE AREA SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING...WITH COOLER AND DRIER AIR FILTERING BACK INTO THE REGION EARLY NEXT WEEK. LOWS TONIGHT WILL DROP INTO THE MID 50S TO LOW 60S...WITH HIGHS ON SUNDAY RANGING BETWEEN THE UPPER 70S AND LOW 80S. && .UPDATE... ISSUED AT 127 AM EDT SUN AUG 23 2015 REMNANTS OF MID LEVEL WAVE IN MISSOURI WAS PUSHING THROUGH THE AREA WITH A FEW SHOWERS NOW MOVING INTO FAR SW COUNTIES. DRY AIRMASS IS LIKELY LIMITING HOW MUCH IS REACHING THE GROUND...BUT STILL APPEARS ENOUGH TO WARRANT THROWING IN SOME 15 TO 20 POPS FOR A FEW HOURS. HRRR SEEMS TO HANDLE THIS FAIRLY WELL AND TRACKS IT EAST WITH A WEAKENING TREND SO WILL FOLLOW ITS LEAD BUT WATCH FOR CHANGES IN TRENDS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 331 PM EDT SAT AUG 22 2015 A SMALLER SCALE/CONVECTIVELY AIDED MID LEVEL TROUGH ACROSS MISSOURI WILL DAMPEN EASTWARD THROUGH THE OHIO VALLEY TONIGHT. DEEPER MOISTURE/PRECIP CHANCES WITH THIS FEATURE WILL REMAIN WELL SSW OF THE LOCAL AREA WITH ONLY A GRADUAL INCREASE IN MID-HIGH LEVEL CLOUDS ANTICIPATED AS WEAK WAA ENSUES ON BACKSIDE OF EXITING SFC HIGH. A VIGOROUS/DEEPENING UPPER LEVEL SYSTEM JUST ENTERING THE NORTHERN PLAINS WILL CLOSE OFF INTO FAR SOUTHWEST ONTARIO BY LATER SUNDAY- SUNDAY NIGHT. AN UNDERCUTTING SHORTWAVE WILL TAKE ON A NEGATIVE TILT AS IT LIFTS NE THROUGH THE WESTERN/NORTHERN LAKES DURING THIS TIME...FORCING A RELATIVELY STRONG SFC COLD FRONT THROUGH THE AREA SUNDAY AFTN-EARLY EVE. MORE FOCUSED DEEP LAYER FORCING WITH THE AFOREMENTIONED WAVE WILL PASS NNW OF THE IWX CWA...THOUGH INCREASING UPPER LEVEL DIVERGENCE AND WEAK HEIGHT FALLS/SHOT OF PV ADVECTION EXPECTED ACROSS AT LEAST NORTHERN ZONES BY LATE MORNING-AFTN. THIS IN TANDEM WITH FAVORABLE DIURNAL TIMING, DECENT DEPTH TO LOW LEVEL FRONT/CONVERGENCE, AND AMPLE PRE-FRONTAL MOISTURE RETURN (850 MB DEWPOINTS 14-15C & PWATS NEAR 1.5 INCHES WITHIN NARROW THETA-E RIDGE) SHOULD ALLOW AT LEAST SCATTERED CONVECTION TO FIRE CENTRAL/WESTERN ZONES IN THE AFTN...SHIFTING INTO EASTERN ZONES LATE AFTN-EARLY EVE. ALSO RETAINED LOW CHANCE POPS ACROSS NORTHWESTERN ZONES SUNDAY MORNING GIVEN POTENTIAL FOR WEAKENING UPSTREAM ACTIVITY TO SURVIVE INTO MORE STABLE AIR. THERE REMAINS A LOW RISK FOR A FEW SEVERE STORMS GIVEN EXPECTATIONS FOR 1000-1500 J/KG OF MLCAPE AND 30-40 KTS OF EFFECTIVE SHEAR. STRONGER FLOW LAGGING POST-FRONTAL, MEAGER MID-LEVEL LAPSE RATES/FORCING, AND POTENTIAL FOR MORNING CLOUDS TO LIMIT SFC HEATING SHOULD PRECLUDE A MORE WIDESPREAD EVENT. OTHERWISE...TEMPS REMAIN SEASONABLE WITH ONLY MINOR TWEAKS MADE. && .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 331 PM EDT SAT AUG 22 2015 IN THE WAKE OF THE COLD FRONT SUNDAY COLD ADVECTION AND PRONOUNCED BOUNDARY LAYER PRESSURE GRADIENT SUPPORTS STRONG W TO WNW WINDS OVER THE FORECAST AREA...ESPECIALLY AS THE BOUNDARY LAYER MIXES OUT. ADDITIONLLY WITH THE TROF AND ASSOCIATED SURFACE LOW SHIFTING SLOWLY EASTWARD...EXPECT GUSTS TO INCREASE AS WELL. LAKE MICHIGAN WATER TEMPS ARE QUITE WARM NOW AND THIS WILL BE ENOUGH TO FAVOR SLIGHT CHANCE/ISOLD SHRA IN BERRIEN/CASS COUNTIES. ADDITIONALLY THIS CLOUDS WILL OVERSPREAD THE REGION AS CU FIELD FORMS IN THE COLD POOL. WITH THE FETCH ACROSS LAKE MICHIGAN...WIND AND WAVES OVER THE NEAR SHORE WATERS WILL PERSIST AS WELL. WHILE IT IS EARLY TO INCLUDE MENTION OF SURF/BEACH HAZARDS...DO EXPECT TO SEE DANGEROUS SURF CONDITIONS AND WILL NEED TO MONITOR FOR POSSIBLE BEACH HAZARD HEADLINES. GRADIENT RELAXES DURING THE EVENING/OVERNIGHT MONDAY INTO TUESDAY. COOL/DRY AIR REMAINS IN PLACE THROUGH THE REST OF THE EXTENDED. MODELS ALL HINT THAT THERE WILL BE SHORTWAVES RIPPLING THROUGHT THE WESTERLIES AND THROUGH THE MEAN TROF OVER THE GREAT LAKES...HOWEVER PLACEMENT/TIMING/INTENSITY ARE WAY TOO NEBULOUS TO SPECIFICALLY NAIL DOWN ANY PRECIPITATION CHANCES. MODEL CONSENSUS SUGGESTS THAT BY NEXT WEEKEND THERE COULD BE ANOTHER CHANCE OF SHOWERS...AND FOR CONSISTENCY...HAVE INCLUDED SLIGHT CHANCE/CHANCE POP FOR FRIDAY NIGHT/SATURDAY. THIS IS A VERY PESSIMISTIC FORECAST...AND IT IS DOUBTFUL THAT THE 24 HOUR PERIOD WILL BE A WASHOUT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 127 AM EDT SUN AUG 23 2015 TAF SITES SHOULD REMAIN DRY INTO MID MORNING SUNDAY BEFORE AN APPROACHING COLD FRONT BRINGS AT LEAST A NARROW WINDOW OF SHOWERS AND STORMS. CONVECTION WILL DEVELOP NEAR OR JUST TO THE WEST OF KSBN AND THEN INTENSIFY AS IT MOVES EAST. MAY BE SOME THUNDER AT KSBN BUT HIGHER CONFIDENCE AT KFWA TO WARRANT ADDING A TEMPO GROUP. LATER AMENDMENTS WILL BE NEEDED AS EVOLUTION OF UPSTREAM CONVECTION BECOMES CLEARER. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 7 PM EDT TUESDAY FOR LMZ043-046. && $$ UPDATE...FISHER SYNOPSIS...STEINWEDEL SHORT TERM...STEINWEDEL LONG TERM...LEWIS AVIATION...FISHER VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1110 AM MDT SUN AUG 23 2015 .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 406 AM MDT SUN AUG 23 2015 FORECAST CONCERNS WILL BE TEMPERATURES...AND LOW CHANCE FOR PRECIPITATION AT THE END OF THIS PERIOD. SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE PACIFIC INTO NORTH AMERICA. AT JET LEVEL..MODELS STARTED OUT FINE. AT MID LEVELS...THE MODELS WERE CLOSE WITH THE GFS/CANADIAN DOING A LITTLE BETTER THAN THE UKMET...NAM AND ECMWF. THE SREF WAS DOING A LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND AND PRESSURE PATTERN. THE ECMWF WAS DOING A LITTLE BETTER THAN THE CANADIAN...NAM AND GFS ON THE LOW LEVEL THERMAL FIELD. DESPITE CLOSE SOLUTIONS ALOFT FROM MONDAY INTO TUESDAY NIGHT... MODELS HANDLE THE SURFACE PATTERN DIFFERENTLY WHICH DEPENDING ON WHICH SOLUTION IS CORRECT COULD HAVE MAJOR AFFECTS ON THE FORECAST. SO FORECAST CONFIDENCE IS BELOW AVERAGE DURING THIS TIME PERIOD. TODAY/TONIGHT...INITIAL PROBLEM WILL BE TO SEE IF ANY NOCTURNAL CONVECTION WILL BE AROUND IN THE MORNING. 00Z NAM WAS CATCHING THE ISOLATED PRECIPITATION OVER THE WEST CENTRAL PORTION OF THE AREA DURING THE MID AND LATE EVENING WITH A LITTLE LEFT OVER THE FAR SOUTHERN PORTION AT 12Z. THE LATEST RAP WAS SHOWING THE SAME THING. WILL CONTINUE TO WATCH TRENDS BUT IT DOES LOOK LIKE ALL THUNDERSTORMS WILL BE SOUTH OF THE AREA AT THE BEGINNING OF THE DAY. IT LOOKS LIKE WARM AIR ADVECTION ALOFT HAS SPREAD A THICKER MID DECK OF CLOUD COVER OVER THE AREA. IT DOES LOOK LIKE THESE CLOUDS WILL THEN OUT BY LATE MORNING. IF THEY CHOOSE TO HANG ON LONGER THEN THE MAXES MAY BE IMPACTED. LIGHT AND VARIABLE TO LIGHT UPSLOPE WINDS WILL TRANSITION TO A SOUTHERLY FLOW MAINLY OVER THE WESTERN PORTION BY LATE IN THE AFTERNOON. MUCH COOLER AIR MASS AND UNFAVORABLE WIND FIELD WILL MAKE FOR A COOL DAY WITH GUIDANCE IN CLOSE AGREEMENT. LIGHT SOUTHERLY WINDS TONIGHT. AGAIN GUIDANCE PRETTY CLOSE AND TENDED TO GO TOWARD THE COOLER GUIDANCE. MONDAY/MONDAY NIGHT... MODELS DISAGREE ON HOW MUCH TO WARM UP THE MAXES. SURFACE RIDGE WILL BE MOVING TO THE EAST WITH THE LEE TROUGH DEVELOPING TO THE WEST. THERE SHOULD BE NO DOWNSLOPE COMPONENT TO THE WINDS AND BELIEVE AT THIS TIME THAT THE WARMER GFS/MAV AND CANADIAN ARE TOO WARM. TENDED TO GO IN THE MIDDLE OF THE TWO EXTREMES. THIS IS WHERE THE FORECAST STARTS GETTING MORE INTERESTING AND UNCERTAIN. MODELS DISAGREE ON EXACTLY WHERE BUT THEY ALL INDICATE A WEAK JET PROVIDING SOME LIFT ACROSS THE AREA FROM THE LATE EVENING INTO THE OVERNIGHT HOURS. MODELS SHOW A SHORTWAVE TROUGH MOVING ACROSS THE AREA AT THAT TIME WITH A DECENT BAROCLINIC ZONE ACROSS THE EASTERN ZONES. MOISTURE DEFINITELY APPEARS TO BE A PROBLEM BUT THERE LOOKS TO BE A LOT OF ELEVATED CAPE WITH THE ELEVATED CINH POSSIBLY BEING OVERCOME. ONLY MODELS SHOWING SOME QPF ARE THE GFS AND THE ENSEMBLE MEAN. AT THIS TIME WILL PUT IN A SLIGHT CHANCE OF THUNDERSTORMS AFTER MIDNIGHT. IN RETURN FLOW DURING THE NIGHT...THE 00Z NAM SHOWED AN INCREASE IN BOUNDARY LAYER. THE 06Z NAM BACKED OFF THAT SOLUTION. WAS THINKING OF PUTTING IN PATCHY FOG. BUT NOW WILL NOT AND WILL ONLY INCREASE CLOUD COVER. TUESDAY/TUESDAY NIGHT...WHATEVER STRATUS IS AROUND IS GONE BY LATE MORNING. AT THIS TIME WILL LEAVE THE MENTION OF ANY THUNDERSTORMS OUT DURING THE MORNING SINCE THIS IS UNCERTAIN AND IT LOOKS LIKE WHAT LITTLE PRECIPITATION THERE IS WILL BE TO OUR EAST. MODELS INDICATE THAT SOME KIND OF JET LIFT WILL BE AROUND THROUGH THE ENTIRE DAY WITH SOME SHIFT TOWARD THE WESTERN PORTION OF THE AREA LATE IN THE DAY. DURING THE NIGHT...SOME KIND OF JET LIFT...MAINLY THE RIGHT REAR QUADRANT...MOVES FROM THE WESTERN AND CENTRAL PORTION OF THE AREA IN THE EVENING INTO THE EASTERN PORTION DURING THE OVERNIGHT HOURS. AT THE SAME TIME THE MID LEVEL RIDGE BUILDS INTO THE AREA WITH RIDGE ROUGHLY CENTERED OVER THE CENTRAL AND WESTERN PORTIONS OF OUR AREA. MODELS WANT TO TRY TO PUSH A 700 MB SHORTWAVE INTO THE WESTERN PORTION DURING THE AFTERNOON AND OVERNIGHT HOURS. BECAUSE A COUPLE OF THE MODELS WANT TO PUT A BOUNDARY ACROSS THE CENTER OF OUR AREA...UNDERNEATH A RIDGE WHICH DOES SEEM REASONABLE AT THIS TIME...THOSE MODELS WANT TO PRODUCE PRECIPITATION OVER THE AREA. IF ANY PRECIPITATION WOULD DEVELOP TO OUR WEST...NOT SURE HOW FAR EAST IT WOULD GET DUE TO THE SLOW STORM MOTION. IT IS A LITTLE DISCONCERTING THAT A NUMBER OF MODELS ARE PRODUCING LIGHT QPF IN A SCENARIO WITH VERY LITTLE LIFT. SO AS NOT TOO WAFFLE WILL KEEP THE THUNDERSTORMS OUT OF THE FORECAST BUT THIS PERIOD WILL NEED TO BE LOOKED AT CLOSE AGAIN. MODELS ARE ALL OVER THE PLACE WITH WHAT TO DO AT THE SURFACE. THE GFS...CANADIAN AND TO A LESSER EXTENT THE ECMWF WANT TO DRAPE A BOUNDARY ACROSS OUR AREA WITH EAST WINDS ACROSS A MAJORITY OF OUR AREA. OTHER MODELS HAVE SOUTHEASTERLY WINDS. DID NOT WANT TO WARM UP THINGS TOO MUCH...ESPECIALLY AS MUCH AS THE GFS/MAV WANTED TO DO...WITH OTHER GUIDANCE COOLER. WENT TOWARD THAT COOLER GUIDANCE. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 406 AM MDT SUN AUG 23 2015 WEST TO NORTHWEST FLOW ALOFT WILL CONTINUE AS THE UPPER LEVEL RIDGE MOVES SOUTH AND WEST OF THE REGION IN THE BEGINNING OF THE EXTENDED PERIOD. SHOWERS AND THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY NIGHT THROUGH THE WEEKEND AS PERTURBATIONS MOVE ALONG THE RIDGE AND THE HEIGHT FIELD APPEARS TO WEAKEN. MODELS HAVE BEEN HINTING THAT A STRONGER WAVE WILL SLOWLY MOVE ALONG THE PERIPHERY OF THE RIDGE FROM COLORADO/WYOMING SOUTHEAST INTO THE HIGH PLAINS WEDNESDAY NIGHT THROUGH FRIDAY AS MOISTURE INCREASES. THIS LOOKS TO GENERATE PRECIP CHANCES DURING THIS TIME FRAME WITH THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT. MOSTLY DRY CONDITIONS RETURN IN TIME FOR THE WEEKEND AS THE RIDGE MOVES EASTWARD TOWARDS THE PLAINS BEHIND THE DISTURBANCE. STRENGTH OF THE RIDGE WILL DETERMINE IF THESE PRECIP CHANCES HOLD UP AS THE PERIOD GETS CLOSER. A DECREASE IN TEMPERATURES IS CURRENTLY EXPECTED WEDNESDAY THROUGH THE END OF THE WORK WEEK WITH HIGHS IN THE LOW TO MID 80S ON FRIDAY BEFORE INCREASING OVER THE WEEKEND. LOW TEMPERATURES WILL FOLLOW SUITE...DROPPING INTO THE MID 50S TO LOW 60S BY FRIDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1110 AM MDT SUN AUG 23 2015 VFR CONDITIONS ANTICIPATED AT BOTH SITES OVER THE NEXT 24 HOURS. WITH A DRY ATMOSPHERE IN PLACE...SURFACE HIGH PRESSURE SLIDING THROUGH AND A STOUT INVERSION...DO NOT ANTICIPATE ANY PRECIPITATION. MID/UPPER CLOUDS MAY PASS THROUGH TODAY BEFORE CLEAR SKIES BECOME DOMINANT TONIGHT. SOUTH WINDS RETURN LATE THIS AFTERNOON AS A LEE TROUGH DEVELOPS ALONG THE COLORADO FRONT RANGE AND SURFACE HIGH PRESSURE EXITS TO THE EAST. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...JBH AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
414 AM MDT SUN AUG 23 2015 .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 406 AM MDT SUN AUG 23 2015 FORECAST CONCERNS WILL BE TEMPERATURES...AND LOW CHANCE FOR PRECIPITATION AT THE END OF THIS PERIOD. SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE PACIFIC INTO NORTH AMERICA. AT JET LEVEL..MODELS STARTED OUT FINE. AT MID LEVELS...THE MODELS WERE CLOSE WITH THE GFS/CANADIAN DOING A LITTLE BETTER THAN THE UKMET...NAM AND ECMWF. THE SREF WAS DOING A LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND AND PRESSURE PATTERN. THE ECMWF WAS DOING A LITTLE BETTER THAN THE CANADIAN...NAM AND GFS ON THE LOW LEVEL THERMAL FIELD. DESPITE CLOSE SOLUTIONS ALOFT FROM MONDAY INTO TUESDAY NIGHT... MODELS HANDLE THE SURFACE PATTERN DIFFERENTLY WHICH DEPENDING ON WHICH SOLUTION IS CORRECT COULD HAVE MAJOR AFFECTS ON THE FORECAST. SO FORECAST CONFIDENCE IS BELOW AVERAGE DURING THIS TIME PERIOD. TODAY/TONIGHT...INITIAL PROBLEM WILL BE TO SEE IF ANY NOCTURNAL CONVECTION WILL BE AROUND IN THE MORNING. 00Z NAM WAS CATCHING THE ISOLATED PRECIPITATION OVER THE WEST CENTRAL PORTION OF THE AREA DURING THE MID AND LATE EVENING WITH A LITTLE LEFT OVER THE FAR SOUTHERN PORTION AT 12Z. THE LATEST RAP WAS SHOWING THE SAME THING. WILL CONTINUE TO WATCH TRENDS BUT IT DOES LOOK LIKE ALL THUNDERSTORMS WILL BE SOUTH OF THE AREA AT THE BEGINNING OF THE DAY. IT LOOKS LIKE WARM AIR ADVECTION ALOFT HAS SPREAD A THICKER MID DECK OF CLOUD COVER OVER THE AREA. IT DOES LOOK LIKE THESE CLOUDS WILL THEN OUT BY LATE MORNING. IF THEY CHOOSE TO HANG ON LONGER THEN THE MAXES MAY BE IMPACTED. LIGHT AND VARIABLE TO LIGHT UPSLOPE WINDS WILL TRANSITION TO A SOUTHERLY FLOW MAINLY OVER THE WESTERN PORTION BY LATE IN THE AFTERNOON. MUCH COOLER AIR MASS AND UNFAVORABLE WIND FIELD WILL MAKE FOR A COOL DAY WITH GUIDANCE IN CLOSE AGREEMENT. LIGHT SOUTHERLY WINDS TONIGHT. AGAIN GUIDANCE PRETTY CLOSE AND TENDED TO GO TOWARD THE COOLER GUIDANCE. MONDAY/MONDAY NIGHT... MODELS DISAGREE ON HOW MUCH TO WARM UP THE MAXES. SURFACE RIDGE WILL BE MOVING TO THE EAST WITH THE LEE TROUGH DEVELOPING TO THE WEST. THERE SHOULD BE NO DOWNSLOPE COMPONENT TO THE WINDS AND BELIEVE AT THIS TIME THAT THE WARMER GFS/MAV AND CANADIAN ARE TOO WARM. TENDED TO GO IN THE MIDDLE OF THE TWO EXTREMES. THIS IS WHERE THE FORECAST STARTS GETTING MORE INTERESTING AND UNCERTAIN. MODELS DISAGREE ON EXACTLY WHERE BUT THEY ALL INDICATE A WEAK JET PROVIDING SOME LIFT ACROSS THE AREA FROM THE LATE EVENING INTO THE OVERNIGHT HOURS. MODELS SHOW A SHORTWAVE TROUGH MOVING ACROSS THE AREA AT THAT TIME WITH A DECENT BAROCLINIC ZONE ACROSS THE EASTERN ZONES. MOISTURE DEFINITELY APPEARS TO BE A PROBLEM BUT THERE LOOKS TO BE A LOT OF ELEVATED CAPE WITH THE ELEVATED CINH POSSIBLY BEING OVERCOME. ONLY MODELS SHOWING SOME QPF ARE THE GFS AND THE ENSEMBLE MEAN. AT THIS TIME WILL PUT IN A SLIGHT CHANCE OF THUNDERSTORMS AFTER MIDNIGHT. IN RETURN FLOW DURING THE NIGHT...THE 00Z NAM SHOWED AN INCREASE IN BOUNDARY LAYER. THE 06Z NAM BACKED OFF THAT SOLUTION. WAS THINKING OF PUTTING IN PATCHY FOG. BUT NOW WILL NOT AND WILL ONLY INCREASE CLOUD COVER. TUESDAY/TUESDAY NIGHT...WHATEVER STRATUS IS AROUND IS GONE BY LATE MORNING. AT THIS TIME WILL LEAVE THE MENTION OF ANY THUNDERSTORMS OUT DURING THE MORNING SINCE THIS IS UNCERTAIN AND IT LOOKS LIKE WHAT LITTLE PRECIPITATION THERE IS WILL BE TO OUR EAST. MODELS INDICATE THAT SOME KIND OF JET LIFT WILL BE AROUND THROUGH THE ENTIRE DAY WITH SOME SHIFT TOWARD THE WESTERN PORTION OF THE AREA LATE IN THE DAY. DURING THE NIGHT...SOME KIND OF JET LIFT...MAINLY THE RIGHT REAR QUADRANT...MOVES FROM THE WESTERN AND CENTRAL PORTION OF THE AREA IN THE EVENING INTO THE EASTERN PORTION DURING THE OVERNIGHT HOURS. AT THE SAME TIME THE MID LEVEL RIDGE BUILDS INTO THE AREA WITH RIDGE ROUGHLY CENTERED OVER THE CENTRAL AND WESTERN PORTIONS OF OUR AREA. MODELS WANT TO TRY TO PUSH A 700 MB SHORTWAVE INTO THE WESTERN PORTION DURING THE AFTERNOON AND OVERNIGHT HOURS. BECAUSE A COUPLE OF THE MODELS WANT TO PUT A BOUNDARY ACROSS THE CENTER OF OUR AREA...UNDERNEATH A RIDGE WHICH DOES SEEM REASONABLE AT THIS TIME...THOSE MODELS WANT TO PRODUCE PRECIPITATION OVER THE AREA. IF ANY PRECIPITATION WOULD DEVELOP TO OUR WEST...NOT SURE HOW FAR EAST IT WOULD GET DUE TO THE SLOW STORM MOTION. IT IS A LITTLE DISCONCERTING THAT A NUMBER OF MODELS ARE PRODUCING LIGHT QPF IN A SCENARIO WITH VERY LITTLE LIFT. SO AS NOT TOO WAFFLE WILL KEEP THE THUNDERSTORMS OUT OF THE FORECAST BUT THIS PERIOD WILL NEED TO BE LOOKED AT CLOSE AGAIN. MODELS ARE ALL OVER THE PLACE WITH WHAT TO DO AT THE SURFACE. THE GFS...CANADIAN AND TO A LESSER EXTENT THE ECMWF WANT TO DRAPE A BOUNDARY ACROSS OUR AREA WITH EAST WINDS ACROSS A MAJORITY OF OUR AREA. OTHER MODELS HAVE SOUTHEASTERLY WINDS. DID NOT WANT TO WARM UP THINGS TOO MUCH...ESPECIALLY AS MUCH AS THE GFS/MAV WANTED TO DO...WITH OTHER GUIDANCE COOLER. WENT TOWARD THAT COOLER GUIDANCE. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 406 AM MDT SUN AUG 23 2015 WEST TO NORTHWEST FLOW ALOFT WILL CONTINUE AS THE UPPER LEVEL RIDGE MOVES SOUTH AND WEST OF THE REGION IN THE BEGINNING OF THE EXTENDED PERIOD. SHOWERS AND THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY NIGHT THROUGH THE WEEKEND AS PERTURBATIONS MOVE ALONG THE RIDGE AND THE HEIGHT FIELD APPEARS TO WEAKEN. MODELS HAVE BEEN HINTING THAT A STRONGER WAVE WILL SLOWLY MOVE ALONG THE PERIPHERY OF THE RIDGE FROM COLORADO/WYOMING SOUTHEAST INTO THE HIGH PLAINS WEDNESDAY NIGHT THROUGH FRIDAY AS MOISTURE INCREASES. THIS LOOKS TO GENERATE PRECIP CHANCES DURING THIS TIME FRAME WITH THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT. MOSTLY DRY CONDITIONS RETURN IN TIME FOR THE WEEKEND AS THE RIDGE MOVES EASTWARD TOWARDS THE PLAINS BEHIND THE DISTURBANCE. STRENGTH OF THE RIDGE WILL DETERMINE IF THESE PRECIP CHANCES HOLD UP AS THE PERIOD GETS CLOSER. A DECREASE IN TEMPERATURES IS CURRENTLY EXPECTED WEDNESDAY THROUGH THE END OF THE WORK WEEK WITH HIGHS IN THE LOW TO MID 80S ON FRIDAY BEFORE INCREASING OVER THE WEEKEND. LOW TEMPERATURES WILL FOLLOW SUITE...DROPPING INTO THE MID 50S TO LOW 60S BY FRIDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1129 PM MDT SAT AUG 22 2015 VISIBILITIES HAVE IMPROVED ACROSS THE CENTRAL HIGH PLAINS REGION AS THE COLD FRONT MOVES FURTHER TO THE SOUTHEAST AND HIGH PRESSURE CONTINUES TO PUSH IN AT THE SURFACE BEHIND THE COLD FRONT. EXPECT CONDITIONS TO REMAIN VFR THROUGH THE TAF PERIOD AT MCK AND GLD WITH SCATTERED LOW TO MID CLOUDS AND ISOLATED SHOWERS AND THUNDERSTORMS TO MOVE ACROSS THE REGION MAINLY SOUTH OF THE TAF SITES. EXPECT WINDS TO SLACKEN AND BECOME VARIABLE AS THE CENTER OF THE SURFACE HIGH MOVES ACROSS THE REGION AROUND 18Z SUNDAY WITH WINDS TURNING TO THE SOUTHEAST AND REMAINING LIGHT AS THE HIGH MOVES INTO THE SOUTHERN PLAINS AND RETURN FLOW SETS UP ACROSS THE CENTRAL HIGH PLAINS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...JBH AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
601 PM EDT SUN AUG 23 2015 ...UPDATED AVIATION DISCUSSION... ...FORECAST UPDATE... ISSUED AT 455 PM EDT SUN AUG 23 2015 LATEST AMDAR DATA OUT OF KSDF INDICATE A FAIRLY STOUT CAP AT 700 MB...MORE REPRESENTATIVE OF THE CURRENT RUC FORECAST SOUNDING FOR THIS HOUR THAN THE NAM. THAT SAME MODEL...AS WELL AS THE LATEST HRRR TRY TO GET A SMALL LINE OF SCATTERED STORMS INTO OUR NORTH AND NORTHEAST AFTER 23Z...CLOSE TO THE COLD FRONT. HAVE TRIMMED POPS SOME TO ACCOUNT FOR THESE LOCATIONS. DRY AIR IN THE MID LEVELS AS WELL AS NEAR THE SURFACE COULD MEAN SOME STRONGER WIND GUSTS OUT OF THESE STORMS. .SHORT TERM (NOW THROUGH MONDAY NIGHT)... ISSUED AT 304 PM EDT SUN AUG 23 2015 AN UPPER LEVEL CLOSED LOW AND ASSOCIATED SURFACE LOW WILL SLOWLY MOVE ACROSS SOUTHERN CANADA THROUGH THE SHORT TERM PERIOD, JUST TO THE NORTH OF THE GREAT LAKES REGION. A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL SWING THROUGH THE LOWER OHIO VALLEY THIS EVENING INTO THE OVERNIGHT HOURS. THE MAIN QUESTION FOR LATE THIS AFTERNOON INTO THE EVENING HOURS WILL BE WHETHER STORMS WILL DEVELOP JUST AHEAD OF THE COLD FRONT AND HOW STRONG THESE STORMS WILL BE. MUCH OF THE GUIDANCE CONTINUES TO SHOW ISOLATED TO SCATTERED SHOWERS AND STORMS WILL DEVELOP AROUND 23- 0Z ACROSS THE WESTERN PORTION OF THE FORECAST AREA AND MOVE EASTWARD THROUGH THE EVENING. AHEAD OF THE FRONT THERE WILL BE A CORRIDOR OF INSTABILITY WITH 1000+ J/KG MUCAPE ACROSS WEST CENTRAL KY AND SOUTHERN IN. IN ADDITION, THERE WILL BE BETTER EFFECTIVE SHEAR OF POTENTIALLY 30 KNOTS OR SO ACROSS SOUTHERN INDIANA. THIS WILL WEAKEN QUICKLY AFTER 0Z AND THE INSTABILITY WILL DECREASE. THEREFORE, THERE IS A SMALL WINDOW OF OPPORTUNITY ALONG AND NORTH OF THE OHIO RIVER WHERE SOME STRONG STORMS COULD DEVELOP. THE THREAT FROM ANY STRONGER STORMS WOULD BE DAMAGING WIND GUSTS. THIS THREAT SHOULD DIMINISH QUICKLY INTO THE EVENING AS WE LOSE THE SHEAR AND INSTABILITY. THEREFORE, THINK MUCH OF CENTRAL KY WILL ONLY SEE SHOWERS AND ISOLATED THUNDERSTORMS. HAVE KEPT COVERAGE FAIRLY LOW AS WELL. STORMS SHOULD MOVE OUT OF EAST CENTRAL KENTUCKY BY 06Z OR SO AS THE FRONT MOVES THROUGH THE REGION. MUCH DRIER AND COOLER AIR WILL FILTER IN BEHIND THE FRONT. SKIES TOMORROW AND TOMORROW NIGHT SHOULD BE MOSTLY CLEAR. LOWS TONIGHT WILL RANGE FROM THE MID 50S TO MID 60S AND WILL DEPEND SOMEWHAT ON HOW FAST THE COLD AIR MOVES IN BEHIND THE FRONT. HIGHS TOMORROW WILL BE QUITE A BIT COOLER IN THE UPPER 70S WITH LOWS TOMORROW NIGHT DIPPING INTO THE MID TO UPPER 50S. .LONG TERM (TUESDAY THROUGH SUNDAY)... ISSUED AT 305 PM EDT SUN AUG 23 2015 SFC HIGH PRESSURE AND A BROAD TROUGH OVER THE EASTERN CONUS ASSOCIATED WITH A STRONG UPPER LOW OVER SOUTHERN CANADA WILL BRING COOL, UNSEASONABLY DRY WEATHER FOR TUES-THU. HIGHS WILL RANGE FROM THE MID 70S TO AROUND 80 WITH LOWS IN THE 50S TO AROUND 60. SOME OF THE COLDEST LOCATIONS COULD TOUCH THE UPPER 40S WED MORNING. BY THE END OF THE WEEK AND INTO THE WEEKEND, THIS PATTERN WILL BREAK DOWN AS THE UPPER LOW EXITS CANADA TO THE EAST RESULTING IN A LESS AMPLIFIED PATTERN OVER THE CONUS. WARM AIR WILL PUSH BACK NORTH INTO THE OHIO VALLEY FOR THE END OF THE WEEK AND THROUGH THE WEEKEND WITH HIGHS RISING INTO THE LOW TO MID 80S FRI-SUN. LOW TEMPS WILL RANGE THROUGH THE 60S. BY THE WEEKEND WE MAY SEE A SHOT AT SOME SHOWERS/STORMS DEPENDING ON IF WE ENTER MORE OF A NW FLOW WITH MCS`S (GFS SOLN) OR IF A STRONG RIDGE QUICKLY BUILDS IN OVER THE OHIO VALLEY WHICH MAY LEAVE US MORE DRY AND WARMER (ECMWF SOLN). && .AVIATION (00Z TAF UPDATE)... ISSUED AT 600 PM EDT SUN AUG 23 2015 HAVE A THIN LINE OF SHOWERS JUST WEST OF KSDF THIS HOUR. STILL NOT CONFIDENT IN ITS SURVIVAL TO THE TERMINAL BASED ON LATEST AMDAR SOUNDINGS...BUT WILL KEEP IN VICINITY STORMS FOR A FEW HOURS AT THE BEGINNING OF THE TAFS. THINK THE LINE WILL BE WEAKER BY THE TIME IT REACHES KBWG/KLEX...SO AS IN THE PREVIOUS FORECAST KEEPING THEM SHOWERS ONLY. WILL AMEND AS WE SEE HOW CELLS DEVELOP. SKIES SHOULD CLEAR QUICKLY BEHIND THE FRONT...WITH WINDS SWITCHING TO NORTHWESTERLY FOR THE REST OF THE PERIOD. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ UPDATE.........RJS SHORT TERM.....EER LONG TERM......AMS AVIATION.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
456 PM EDT SUN AUG 23 2015 ...FORECAST UPDATE... ISSUED AT 455 PM EDT SUN AUG 23 2015 LATEST AMDAR DATA OUT OF KSDF INDICATE A FAIRLY STOUT CAP AT 700 MB...MORE REPRESENTATIVE OF THE CURRENT RUC FORECAST SOUNDING FOR THIS HOUR THAN THE NAM. THAT SAME MODEL...AS WELL AS THE LATEST HRRR TRY TO GET A SMALL LINE OF SCATTERED STORMS INTO OUR NORTH AND NORTHEAST AFTER 23Z...CLOSE TO THE COLD FRONT. HAVE TRIMMED POPS SOME TO ACCOUNT FOR THESE LOCATIONS. DRY AIR IN THE MID LEVELS AS WELL AS NEAR THE SURFACE COULD MEAN SOME STRONGER WIND GUSTS OUT OF THESE STORMS. .SHORT TERM (NOW THROUGH MONDAY NIGHT)... ISSUED AT 304 PM EDT SUN AUG 23 2015 AN UPPER LEVEL CLOSED LOW AND ASSOCIATED SURFACE LOW WILL SLOWLY MOVE ACROSS SOUTHERN CANADA THROUGH THE SHORT TERM PERIOD, JUST TO THE NORTH OF THE GREAT LAKES REGION. A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL SWING THROUGH THE LOWER OHIO VALLEY THIS EVENING INTO THE OVERNIGHT HOURS. THE MAIN QUESTION FOR LATE THIS AFTERNOON INTO THE EVENING HOURS WILL BE WHETHER STORMS WILL DEVELOP JUST AHEAD OF THE COLD FRONT AND HOW STRONG THESE STORMS WILL BE. MUCH OF THE GUIDANCE CONTINUES TO SHOW ISOLATED TO SCATTERED SHOWERS AND STORMS WILL DEVELOP AROUND 23- 0Z ACROSS THE WESTERN PORTION OF THE FORECAST AREA AND MOVE EASTWARD THROUGH THE EVENING. AHEAD OF THE FRONT THERE WILL BE A CORRIDOR OF INSTABILITY WITH 1000+ J/KG MUCAPE ACROSS WEST CENTRAL KY AND SOUTHERN IN. IN ADDITION, THERE WILL BE BETTER EFFECTIVE SHEAR OF POTENTIALLY 30 KNOTS OR SO ACROSS SOUTHERN INDIANA. THIS WILL WEAKEN QUICKLY AFTER 0Z AND THE INSTABILITY WILL DECREASE. THEREFORE, THERE IS A SMALL WINDOW OF OPPORTUNITY ALONG AND NORTH OF THE OHIO RIVER WHERE SOME STRONG STORMS COULD DEVELOP. THE THREAT FROM ANY STRONGER STORMS WOULD BE DAMAGING WIND GUSTS. THIS THREAT SHOULD DIMINISH QUICKLY INTO THE EVENING AS WE LOSE THE SHEAR AND INSTABILITY. THEREFORE, THINK MUCH OF CENTRAL KY WILL ONLY SEE SHOWERS AND ISOLATED THUNDERSTORMS. HAVE KEPT COVERAGE FAIRLY LOW AS WELL. STORMS SHOULD MOVE OUT OF EAST CENTRAL KENTUCKY BY 06Z OR SO AS THE FRONT MOVES THROUGH THE REGION. MUCH DRIER AND COOLER AIR WILL FILTER IN BEHIND THE FRONT. SKIES TOMORROW AND TOMORROW NIGHT SHOULD BE MOSTLY CLEAR. LOWS TONIGHT WILL RANGE FROM THE MID 50S TO MID 60S AND WILL DEPEND SOMEWHAT ON HOW FAST THE COLD AIR MOVES IN BEHIND THE FRONT. HIGHS TOMORROW WILL BE QUITE A BIT COOLER IN THE UPPER 70S WITH LOWS TOMORROW NIGHT DIPPING INTO THE MID TO UPPER 50S. .LONG TERM (TUESDAY THROUGH SUNDAY)... ISSUED AT 305 PM EDT SUN AUG 23 2015 SFC HIGH PRESSURE AND A BROAD TROUGH OVER THE EASTERN CONUS ASSOCIATED WITH A STRONG UPPER LOW OVER SOUTHERN CANADA WILL BRING COOL, UNSEASONABLY DRY WEATHER FOR TUES-THU. HIGHS WILL RANGE FROM THE MID 70S TO AROUND 80 WITH LOWS IN THE 50S TO AROUND 60. SOME OF THE COLDEST LOCATIONS COULD TOUCH THE UPPER 40S WED MORNING. BY THE END OF THE WEEK AND INTO THE WEEKEND, THIS PATTERN WILL BREAK DOWN AS THE UPPER LOW EXITS CANADA TO THE EAST RESULTING IN A LESS AMPLIFIED PATTERN OVER THE CONUS. WARM AIR WILL PUSH BACK NORTH INTO THE OHIO VALLEY FOR THE END OF THE WEEK AND THROUGH THE WEEKEND WITH HIGHS RISING INTO THE LOW TO MID 80S FRI-SUN. LOW TEMPS WILL RANGE THROUGH THE 60S. BY THE WEEKEND WE MAY SEE A SHOT AT SOME SHOWERS/STORMS DEPENDING ON IF WE ENTER MORE OF A NW FLOW WITH MCS`S (GFS SOLN) OR IF A STRONG RIDGE QUICKLY BUILDS IN OVER THE OHIO VALLEY WHICH MAY LEAVE US MORE DRY AND WARMER (ECMWF SOLN). && .AVIATION (18Z TAF UPDATE)... ISSUED AT 114 PM EDT SUN AUG 23 2015 DRY CONDITIONS WITH SOUTHWESTERLY WINDS ARE EXPECTED THROUGH THE REMAINDER OF THE AFTERNOON. FOR THIS EVENING A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TAF SITES. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THIS FRONT. SDF STILL LOOKS TO STAND THE BEST CHANCE TO SEE ANY THUNDERSTORMS THIS EVENING SO WILL PUT VCTS IN THERE. OTHERWISE THE LINE WILL BE WEAKENING AS IT MOVES THROUGH LEX AND BWG AND CHANCES OF THUNDERSTORMS SEEM SLIM, SO WILL CARRY VCSH. IN THE WAKE OF THE FRONT SKIES WILL CLEAR QUICKLY. WINDS WILL BE OUT OF THE NORTHWEST AT 5-7 KNOTS TOMORROW. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ UPDATE.........RJS SHORT TERM.....EER LONG TERM......AMS AVIATION.......EER
AREA FORECAST DISCUSSION
NWS JACKSON KY
210 AM EDT SUN AUG 23 2015 .UPDATE... ISSUED AT 1110 PM EDT SAT AUG 22 2015 WATER VAPOR SAT AND MOST MODELS ARE CONTINUING TO SHOW MID LEVEL WAVE PROGRESSING EAST INTO THE REGION. THAT SAID RIGHT NOW THINK THE GFS HAS THE BEST HANDLE ON THE SYNOPTICS THIS EVENING...THE NAM SEEMS A BIT TOO ROBUST WITH MOISTURE OVERALL. NOW RADAR HAS SHOWN A FEW RETURNS TO THE SW AND INTO PORTIONS OF CENTRAL KY...BUT MUCH OF THIS IS AT MOST SPRINKLES BASED ON THE HIGH BASES/MOSTLY ABOVE 10 KFT. THEREFORE JUST ISSUED A GNOW TO COVER THIS GIVEN THE FACT THAT THIS ACTIVITY IS LIKELY NOT MEASURING. THE HRRR HAS CONTINUED TO WEAKEN ANY OF THE SHOWERS ACROSS CENTRAL KY AND MIDDLE TN...SO DID NOT ADJUST THE POPS UP MUCH GIVEN THIS TREND. MAINLY MADE SOME ADJUSTMENTS TO TEMP/DEWS/WINDS WITH LATEST OBS. UPDATE ISSUED AT 727 PM EDT SAT AUG 22 2015 SYNOPTICALLY WE CONTINUE TO HAVE HIGH PRESSURE CENTERED OFF TO THE NE NEAR THE UPPER MID ATLANTIC REGION...BUT STILL KEEPING CONTROL OF THE OVERALL SENSIBLE WEATHER HERE IN EASTERN KY. MODELS AND WV IMAGERY INDICATE LEAD MID LEVEL WAVE SLOWLY MOVING EAST ACROSS THE MIDDLE MISSISSIPPI RIVER VALLEY. THIS HAS SPARKED OFF SHOWERS AND THUNDERSTORMS IN MIDDLE TN...WEST TN...WESTERN KY THAT ARE SLOWLY MOVING NORTH AND EAST...HOWEVER THEY ARE LOSING STEAM AS THEY MOVE NE WITH GENERALLY DRIER AIR IN PLACE AND HIGH PRESSURE NOSING SOUTH. OVERALL THE CAMS SEEM TO KEEP THIS TREND THIS EVENING AS WELL...ALSO THEY DO HAVE SOME SIGNAL OVERNIGHT/EARLY MORNING SUNDAY AND WE ALREADY HAVE SLIGHT POPS IN THE SOUTH AND SOUTHEAST TO MATCH. THEREFORE THINK POPS THIS EVENING/OVERNIGHT ARE IN GOOD SHAPE IN REGARDS TO PREVIOUS FORECAST AND LATEST TRENDS. JUST SOME MINOR UPDATES TO IN TEMPS/DEWS/WINDS WITH LATEST OBS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 340 PM EDT SAT AUG 22 2015 THIS AFTERNOON...A SHORTWAVE RIDGE WAS WORKING ACROSS THE REGION DOWNSTREAM OF A SHORTWAVE NEARING THE MID MS AND LOWER OH VALLEYS. ANOTHER MORE POTENT SHORTWAVE MEANWHILE IS WORKING FROM THE NORTHERN ROCKIES INTO THE DAKOTAS. AT THE SFC...A LOW PRESSURE SYSTEM PRECEDING THE MORE POTENT SHORTWAVE WAVE CENTERED OVER THE NE SD AND NW MN AREA. THE LEAD SHORTWAVE WILL BRING INCREASING MID AND HIGH MOISTURE LEADING TO AN INCREASE IN MID AND HIGH CLOUDS THROUGH THE EVENING AND INTO THE OVERNIGHT. LOW LEVEL MOISTURE WILL ALSO INCREASE A BIT AS WELL ESPECIALLY ACROSS THE SOUTH. AS THE SHORTWAVE PASSES LATE TONIGHT A SHOWER OR TWO MAY CREEP NORTH INTO THE SOUTHERN TIER OF COUNTIES FROM WAYNE NORTHEAST TOWARD LETCHER. MUCH OF SUNDAY FEATURE SOME HEIGHT RISES AND MOSTLY DRY WEATHER IN BETWEEN THE DEPARTING INITIAL LEAD SHORTWAVE AND THE NEXT APPROACHING SHORTWAVE AND THE COLD FRONT AS THE UPPER LEVEL LOW AND SFC LOW PRESSURE CENTER MOVE INTO ONTARIO. THE SYSTEM WILL GENERALLY BE RATHER MOISTURE STARVED AND INSTABILITY WILL BE LIMITED DUE TO THE NON OPTIMAL TIMING OF THE COLD FRONT WHILE THE BEST FORCING WILL ALSO PASS NORTH OF THE AREA. ANY CONVECTION FROM LATE SUNDAY INTO SUNDAY NIGHT WILL LIKELY BE MAINLY ISOLATED TO SCATTERED SHOWERS ALTHOUGH A FEW ISOLATED RUMBLES CANNOT BE COMPLETELY RULED OUT. QPF FROM THIS SYSTEM SHOULD ALSO BE LIGHT AND MANY LOCATIONS SHOULD REMAIN DRY THROUGH THE ENTIRE EVENT. TEMPERATURES WILL MODERATE A FEW DEGREES FROM LAST NIGHTS OVERNIGHT LOWS ALTHOUGH LESS CLOUD COVER IN THE NORTH AND NORTHEAST SHOULD LEAD TO LOWER MIN T THERE...REACHING THE UPPER 50S FOR VALLEY LOCATIONS. AHEAD OF THE FRONT...WITH A WARMER START AND WARM AIR ADVECTION AHEAD OF THE FRONT...TEMPERATURES SHOULD BE A COUPLE DEGREES WARMER THAN TODAY ON AVERAGE. HOWEVER...HIGHS ON SUNDAY SHOULD STILL BE NEAR NORMAL FOR THE LATTER PART OF AUGUST. CLOUDS AND SOME PRECIP IN THE AREA AS THE FRONT BEGINS TO WORK ACROSS EAST KY WILL LEAD TO AN EVEN MILDER NIGHT ON SUNDAY NIGHT. HOWEVER...A RETURN TO BELOW NORMAL TEMPERATURES IS EXPECTED DURING THE LONG TERM PERIOD. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 246 PM EDT SAT AUG 22 2015 SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION AS A COLD FRONT DEPARTS TO OUR EAST ON MONDAY. A FEW SHOWERS WILL REMAIN IN THE FORECAST MONDAY MORNING...BUT THE REST OF THE PERIOD WILL BE DRY AS THE HIGH BECOMES DOMINANT. A VERY FALL LIKE PATTERN CAN BE EXPECTED WITH COMFORTABLE DEWPOINTS AND TEMPERATURES RUNNING 5 TO 10 DEGREES BELOW NORMAL THROUGH MOST OF THE PERIOD...WITH THE BIGGEST DEPARTURES OCCURRING AT NIGHT AS THE DRY AIRMASS ALLOWS TEMPS TO FALL INTO THE 50S. SOME MODIFICATION WILL OCCUR IN THE AIRMASS BY SATURDAY WITH TEMPS WARMING BACK TO NEAR NORMAL LEVELS FOR THE END OF AUGUST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 209 AM EDT SUN AUG 23 2015 HIGH PRESSURE CONTINUES TO SLIDE OFF TO THE NORTHEAST OVERNIGHT. HIGH CLOUDS ARE MAKING THEIR WAY ACROSS THE REGION...AS WELL AS A FEW MID LEVEL CLOUDS...AHEAD OF AN APPROACHING COLD FRONT. WHILE RADAR RETURNS CONTINUE TO APPEAR ON THE RADAR...MOST OF THIS MOISTURE IS IN THE HIGH LEVELS AND WILL NOT MAKE IT TO THE GROUND. AS SUCH...DID NOT MENTION ANY VCSH OR SHRA DURING THE EARLY MORNING PERIOD. DURING THE DAY TODAY...CLOUDS WILL CONTINUE TO BUILD DOWN. EXPECT MOST STATIONS TO STAY AT OR ABOVE VFR CIGS...BUT A FEW PLACES MAY SEE SOME PERIODS OF MVFR. THE COLD FRONT...AS WELL AS THE BEST RAIN/THUNDERSTORMS CHANCES...WILL MOVE ACROSS THE REGION TOMORROW NIGHT...LATE IN THE TAF PERIOD. CIGS WILL LIKELY BE REDUCED TO MVFR AT TIMES BY TOMORROW EVENING. AND GIVEN THE EXPECTED SPOTTY NATURE OF THE SHOWERS/THUNDERSTORMS...AND THE FACT THEY WILL OCCUR SO LATE IN THE PERIOD WHEN UNCERTAINTY IS HIGHER...DID NOT INCLUDE MENTION OF ANY PRECIP AT THIS TIME. WINDS WILL TRANSITION FROM SE TO WESTERLY DURING THE PERIOD...BUT SHOULD REMAIN LIGHT...LESS THAN 5KTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DJ SHORT TERM...JP LONG TERM...ABE AVIATION...JMW
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1156 PM CDT SAT AUG 22 2015 .AVIATION... VFR CONDITIONS EXPECTED THROUGH THE OVERNIGHT HOURS ALTHOUGH SOME BR WILL BE POSSIBLE AT TAF LCTNS TWRDS SR. && .PREV DISCUSSION... /ISSUED 1051 PM CDT SAT AUG 22 2015/ UPDATE...UPDATED GFS AND LATEST HRRR CONFIRMS THAT THE SHORT WAVE ENERGY HAS MOVED A BIT FURTHER SOUTH, SO REMOVED MENTION OF SHOWERS INLAND FROM THE COASTAL MARSHES. SWEENEY PREV DISCUSSION... /ISSUED 819 PM CDT SAT AUG 22 2015/ UPDATE...IR IMAGERY SHOWING MID AND UPPER LEVEL CLOUD COVER WHICH IS CONFIRMED BY THE EVENING SOUNDING. SOME JET ENERGY IS AVAILABLE ACROSS THE NORTHERN ZONES LATE TNITE...ALSO SEEN ON THE IR IMAGERY UPSTREAM OVER NORTH TEXAS. SHORT WAVE ENERGY REMAINS AVAILABLE ACROSS THE SOUTHERN ZONES. CANNOT RULE OUT ISOLATED SHOWER AND THUNDERSTORM ACTIVITY TONIGHT SO ADDED MINIMAL POPS. TEMPS ON TRACK. SWEENEY PREV DISCUSSION... /ISSUED 652 PM CDT SAT AUG 22 2015/ AVIATION... STORMS ARE MOVING TO THE NORTHEAST ACROSS SOUTH-CENTRAL LOUISIANA THIS EVENING. LFT AND ARA WILL STILL HAVE A SLIGHT CHANCE FOR A SHOWER/TSTMS OTHERWISE LCH/AEX AND BPT LOOK TO REMAIN CLEAR OF STORMS THROUGH SUNRISE. STORM ENDING BEFORE MIDNIGHT. K. KUYPER PREV DISCUSSION... /ISSUED 312 PM CDT SAT AUG 22 2015/ DISCUSSION... WEAK SFC HIGH OVER THE NE GULF PROVIDING FOR A LIGHT SE FLOW ACROSS THE REGION. RADAR SHOWING SCT/NUM SHRA/TSRA ACROSS SE TX/C AND S LA THIS AFTERNOON AS INSTABILITY REMAINS HIGH AND FAVORABLE LOW LEVEL MOISTURE. WITH A BIT MORE COVERAGE THAN EXPECTED...BUMPED UP POPS TO 60% FOR MAJORITY OF INLAND AREA NORTH OF THE INTRACOASTAL WATERWAY THIS AFTERNOON. TEMPS ALL OVER THE PLACE FROM THE RAIN COOLED 70S TO LOWER 90S ACROSS C LA WHERE THE RAIN HASN`T REACHED YET. CONVECTION EXPECTED TO DIMINISH THIS EVENING AND THE OVERNIGHT HOURS. BY SUN...DRIER AIR ALOFT EXPECTED TO MINIMALIZE PRECIP CHANCES TO 20% DURING THE AFTERNOON. HIGHS IN THE MID 90S EXPECTED. WITH HIGHER THAN NORMAL DEWPTS IN THE UPPER 70S DURING THE MORNING...TO MID 70S DURING THE AFTERNOON...HEAT INDEX VALUES LIKELY TO RANGE 100-105 FOR MOST OF THE DAYLIGHT HOURS SUN. GENERALLY THE SAME EXPECTED FOR MON AS WELL. HOWEVER...A DEEPENING LONGWAVE TROF OVER THE C AND E U.S. EXPECTED TO ALLOW A COOL FRONT TO MOVE S ACROSS THE REGION MON NIGHT AND TUE. PRECIP CHANCES EXPECTED TO INCREASE BY MON AFTERNOON ACROSS OUR REGION...AND ALONG THE FROPA MON NIGHT/TUE MORNING. POST FRONTAL WX CONTINUES TO LOOK DRY FOR WED INTO THE REMAINDER OF THE WEEK. OVERNIGHT TEMPS LIKELY TO BE IN THE 60S FOR MOST OF THE REGION (EXCEPT COASTAL PARISHES/COUNTIES) FOR NEXT THU & FRI MORNINGS. HIGHS STILL IN THE LOWER 90S...BUT WITH MUCH LOWER DEWPTS IN THE 50S/60S...IT WILL BE MORE BEARABLE OUTSIDE. DML MARINE... A LIGHT ONSHORE FLOW WILL PERSIST TONIGHT...BECOMING VARIABLE SUNDAY AND MONDAY AS THE PRESSURE GRADIENT REMAINS WEAK. CHANCES OF SHOWERS AND THUNDERSTORMS EXPECTED TO INCREASE AGAIN BY LATE MONDAY INTO TUESDAY AS A COOL FRONT MOVES THROUGH THE REGION. && .PRELIMINARY POINT TEMPS/POPS... AEX 76 96 76 95 / 10 20 10 30 LCH 76 93 77 95 / 10 30 10 30 LFT 75 95 76 95 / 10 30 10 40 BPT 79 92 77 95 / 10 30 10 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ AVIATION...04
AREA FORECAST DISCUSSION
NWS CARIBOU ME
629 PM EDT SUN AUG 23 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL LIFT NORTHWARD ACROSS THE REGION OVERNIGHT INTO MONDAY. A SLOW MOVING COLD FRONT WILL APPROACH MONDAY NIGHT THROUGH TUESDAY...THEN BEGIN TO CROSS THE REGION TUESDAY NIGHT THROUGH WEDNESDAY. && .NEAR TERM /THROUGH MONDAY/... 606 PM UPDATE: CHGS THIS UPDATE INCLUDE MENTIONING HEAVIER SHWRS...ISOLD TSTMS AND PATCHY FOG ACROSS THE NRN HLF THE FA FOR LATER TNGT AND THEN INCREASING CVR OF FOG OVR COASTAL AND INTERIOR DOWNEAST PTNS OF THE FA FOR LATE TNGT. RADAR CONTS TO SHOW SHWRS AND OCNL ISOLD TSTMS MOVG N ALG THE LEADING EDGE OF A SFC WARM FRONT. MOST MODEL GUIDANCE SUGGESTS CONTD NNW PROGRESSION OF THIS ACTIVITY INTO THE REST OF THE FA LATER TNGT...WITH SOME UNCERTAINTY OF SHWR INTENSITY...WITH THE LATEST HRRR FCST HRLY SIM RADAR REF INITIALLY OVERDONE BASED ON LATEST ACTUAL RADAR REF RETURNS. SO FOR NOW...WILL RELY ON LONGER RANGE MODELS WHICH ALSO SHOW AN INCREASE IN SHWR CVRG AND PERHAPS INTENSITY ACROSS THE N LATER TNGT...BUT FOR NOW WILL KEEP MAX POPS IN THE HI LIKELY CAT. OTHERWISE...FCST HRLY TEMPS WERE UPDATED THRU THE OVRNGT TO MSLY UNCHGD FCST LOWS MON MORN AT 6 AM BASED ON ACTUAL OBSVD HI TEMPS AND 5 PM HRLY TEMPS. ADJUSTMENTS TO HI TRRN MAX/MIN TEMPS WERE ALSO MADE THRU THE REST OF THE FCST. ORGNL DISC: SHOWERS AND ISOLATED THUNDERSTORMS ARE GRADUALLY BECOMING MORE NUMEROUS ACROSS PORTIONS OF DOWNEAST MAINE THIS AFTERNOON, WHICH WILL CONTINUE INTO THE EVENING HOURS. THESE SHOWERS ARE ASSOCIATED WITH A FRONTAL BOUNDARY WHICH WILL LIFT NORTHWARD ACROSS THE STATE THIS EVENING AND OVERNIGHT. THERE`S LOTS OF MOISTURE ON THE SOUTH SIDE OF THE BOUNDARY, WITH PWATS ALREADY EXCEEDING 1.75 INCHES ALONG THE COAST. AS SUCH, HEAVY RAIN WILL BE A CONCERN THROUGH THE EVENING HOURS. IN ADDITION, THE FLOW AT THE SURFACE AND ALOFT IS FAIRLY WEAK, SO THE INDIVIDUAL CELLS WILL BE SLOW-MOVING. ALTHOUGH SURFACE INSTABILITY WILL WANE AFTER SUNSET, MODEL GUIDANCE INDICATES THERE`LL ENOUGH ELEVATED INSTABILITY TO ALLOW FOR THE RISK OF THUNDER TO CONTINUE. FOR MONDAY...THE BOUNDARY WILL LIFT NORTH OF THE SAINT JOHN VALLEY, AND EXPECT SHOWERS WILL BE ONGOING AT DAYBREAK, ESPECIALLY OVER NORTHERN MAINE. AN UPPER LEVEL LOW WILL BEGIN TO APPROACH FROM THE GREAT LAKES REGION DURING THE DAY. THIS PUTS NORTHERN NEW ENGLAND IN AN AREA OF UPPER LEVEL DIFFLUENCE, WHICH COMBINED WITH PLENTIFUL MOISTURE WILL KEEP SCATTERED SHOWERS AROUND THROUGH THE DAY. SB CAPES OF 500-1000 J/KG WILL BE ENOUGH TO ALLOW FOR THUNDERSTORMS. HIGHS WILL BE IN THE MID 70S TO AROUND 80. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... AN UPPER LEVEL TROF WILL REMAIN WEST OF THE REGION...WITH UPPER LEVEL RIDGING ACROSS THE MARITIMES...MONDAY NIGHT THROUGH WEDNESDAY. A COLD/OCCLUDED FRONT WILL MOVE SLOWLY EAST ACROSS NEW ENGLAND MONDAY NIGHT THROUGH TUESDAY...THEN BEGIN TO CROSS THE FORECAST AREA TUESDAY NIGHT THROUGH WEDNESDAY. UNSETTLED CONDITIONS WILL OCCUR ACROSS THE REGION IN ADVANCE OF THE FRONT AND ALONG THE FRONT. GENERALLY EXPECT MOSTLY CLOUDY SKIES ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE REGION MONDAY NIGHT THROUGH TUESDAY. SHOWER/THUNDERSTORM CHANCES WILL THEN INCREASE TUESDAY NIGHT AND WEDNESDAY ALONG THE FRONT. HOWEVER...THE EXACT TIMING OF THE FRONT AND LOCATION OF THE HEAVIER PRECIPITATION IS STILL UNCERTAIN. TEMPERATURES WILL BE AT NEAR NORMAL LEVELS TUESDAY/WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A SLOW MOVING UPPER LEVEL TROUGH WILL TRUDGE THROUGH NORTHERN NEW ENGLAND WEDNESDAY NIGHT INTO FRIDAY WITH SHOWERS AND ISOLATED THUNDERSTORMS. EXPECT HIGH TEMPERATURES TO BE SLIGHTLY BELOW TO NEAR NORMAL WITH LOW TEMPERATURES NEAR TO SLIGHTLY ABOVE NORMAL DUE TO EXTENSIVE CLOUD COVER. SEASONALLY STRONG ZONAL/WESTERLY FLOW MOVES INTO THE REGION FOR FRIDAY AND NEXT WEEKEND. A BAROCLINIC ZONE SEPARATES A LATE SUMMER AIRMASS OVER THE MID ATLANTIC AND SOUTHERN NEW ENGLAND FROM A MUCH COOLER REGIME ACROSS QUEBEC. THE MEDIUM RANGE MODELS BRING A SERIES OF DISTURBANCES WITH DISTINCT BAROCLINIC LEAVES NEAR NORTHERN MAINE DURING THIS TIME PERIOD. THE EXACT POSITIONS OF THESE LEAVES WILL DETERMINE WHETHER THE REGION EXPERIENCES MOSTLY DRY OR UNSETTLED RAINY WEATHER. FORECAST CONFIDENCE IS LOW 5 TO 7 DAYS OUT. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... NEAR TERM: VFR CONDITIONS WILL PREVAIL THROUGH ABOUT 00Z, THOUGH LOCAL MVFR WILL BE POSSIBLE IN SHOWERS/ISOLATED THUNDERSTORMS AT KBGR AND KBHB UNTIL THEN. THEREAFTER, THE PRECIPITATION WILL LIFT INTO NORTHERN MAINE WITH WIDESPREAD MVFR AT THE NORTHERN SITES. THE SOUTHERN TERMINALS WILL DROP TO IFR/POSSIBLE LIFR AFTER 06Z IN FOG. CONDITIONS WILL IMPROVE TO MVFR AFTER 14Z MONDAY, AND THE NORTHERN SITES WILL REMAIN MVFR AS WELL. SHORT TERM: VARIABLE CONDITIONS WILL OCCUR WITH ANY SHOWERS/THUNDERSTORMS OR PATCHY FOG MONDAY NIGHT THROUGH THURSDAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED MONDAY NIGHT THROUGH THURSDAY. VFR CONDITIONS ARE EXPECTED FRIDAY. && .MARINE... NEAR TERM: NO HEADLINES WILL BE NEEDED OVER THE WATERS TONIGHT OR MONDAY. SWELLS WILL BUILD TO AROUND 4 FEET THIS EVENING AND OVERNIGHT, BUT SEAS ARE EXPECTED TO REMAIN BELOW 5 FEET. FOG WILL ONCE AGAIN RESTRICT VISIBILITY OVER THE WATERS OVERNIGHT INTO MONDAY MORNING. SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS MONDAY NIGHT THROUGH WEDNESDAY. VISIBILITIES WILL BE REDUCED IN SHOWERS AND FOG LATER TUESDAY THROUGH WEDNESDAY. COULD ALSO HAVE A CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...VJN SHORT TERM...NORCROSS LONG TERM...OKULSKI AVIATION...VJN/NORCROSS MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1258 PM EDT SUN AUG 23 2015 .SYNOPSIS... THE STALLED FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT TODAY THROUGH MONDAY. A SLOW MOVING FRONTAL SYSTEM IS EXPECTED APPROACH THE REGION FROM THE WEST ON TUESDAY AND CROSS THE AREA ON WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... 1255 PM UPDATE...A BAND OF SHOWERS WITH ISOLATED THUNDER IS SLOWLY SLIDING NORTHWARD THROUGH SOUTHERN PENOBSCOT AND INTO SOUTHERN PISCATAQUIS COUNTIES. EAST OF THIS AREA, ACTIVITY HAS BEEN SLOW TO DEVELOP. HOWEVER, THERE`S ANOTHER AREA OF SHOWERS AND THUNDERSTORMS THAT HAVE POPPED UP ALONG COASTAL NEW BRUNSWICK. EXPECT THAT THIS CONVECTION WILL CONTINUE TO DEVELOP WESTWARD THIS AFTERNOON. THE LATEST SPC MESOANALYSIS SHOWS SB CAPES ACROSS DOWNEAST MAINE IS NOW 500-1500 J/KG, SO PLENTY OF INSTABILITY FOR THIS CONVECTION TO FIRE UP. PWATS IN THIS AREA ARE ALSO INCREASING TO ABOVE 1.5 INCHES. AS SUCH EXPECT ANY SHOWERS WILL HAVE THE CABABILITY OF PRODUCING HEAVY RAINFALL. MINIMAL FLOW MEANS THEY`LL BE SLOW MOVING AS WELL. HAVE MADE ADJUSTMENTS TO POPS, SKY, AND TEMPS TO BRING ALL INTO BETTER AGREEMENT WITH CURRENT RADAR/SATELLITE/SURFACE OBS TRENDS. PREVIOUS DISCUSSION...SURFACE ANALYSIS SHOWED TROF OR WEAK FRONTAL BOUNDARY DRAPED ACROSS THE DOWNEAST REGION. THIS FEATURE IS FORECAST TO LIFT NORTHWARD TODAY W/MORE HUMID AIR OVERSPREADING THE REGION AS LOW PRES LIFTS NE ACROSS THE WESTERN ATLC. THE 00Z NAM AND HRRR 3KM HAD THINGS INITIALIZED WELL. USED THIS BLEND FOR TODAY`S FORECAST W/PRECIP LIFTING FROM S TO N. SHOWERS WILL MOVE FROM S TO N TODAY. HIGH PRES ANCHORED OVER THE NW ATLC WILL ACT AS A BLOCK INITIALLY AS PRECIP DIES OUT HITTING A DRY AND STABLE AIRMASS IN PLACE ACROSS THE NORTH AND WEST. FURTHER S ACROSS CENTRAL AND DOWNEAST AREAS, SOUNDING DATA SHOWED THE COLUMN MOISTENING THROUGH 700MBS W/INCREASING INSTABILITY. SB CAPES OF 500-1000 JOULES ARE FORECAST TO SETUP THIS AFTERNOON ACROSS THE AFOREMENTIONED AREAS. PWATS ARE 1.7+ W/LIS DOWN TO -2 TO -3. 0-6KM SHEAR IS WEAK < 10 KTS. A WARM CLOUD LAYER W/HIGH FREEZING LEVELS(13-14K FT) WILL LEAD TO LOADING OF PRECIP W/POTENTIAL FOR HEAVY TO TORRENTIAL RAINFALL IN SPOTS. DECIDED TO STAY W/TSTMS THIS AFTERNOON INTO THE EVENING AND ADDED HEAVY RAINFALL WORDING. SHOWERS AND SOME TSTMS ARE EXPECTED TO SPREAD INTO NORTHERN AND WESTERN MAINE TONIGHT. SOUNDING DATA SHOWED MOST OF THE CONVECTION TO BE ELEVATED W/THE HIGHEST THREAT ACROSS THE HOULTON AND MILLINOCKET REGION W/LESS INSTABILITY FURTHER N. ONCE AGAIN HEAVY RAIN THREAT CONTINUES. DOWNEAST AND COASTAL AREAS WILL BECOME MORE STABLE W/FOG AND DRIZZLE. USED A CONSENSUS BLEND ON THE QPF DUE TO LOW CONFIDENCE IN PLACEMENT OF HEAVIER RAINFALL AMOUNTS. SOME AREAS COULD DEFINITELY PICK AN INCH OR MORE OF RAIN IN TSTMS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... UNSETTLED WX PATTERN CONTINUES FOR THE START OF THE WORK WEEK. EXPECT THE CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS BOTH MONDAY AND AGAIN ON TUESDAY AS A TROF OF LOW PRESSURE TRACKS SLOWLY EAST FROM THE GREAT LAKES REGION. HIGH TEMPERATURES BOTH MONDAY AND TUESDAY WILL RANGE FROM THE MID TO UPPER 70S. IT WILL ALSO CONTINUE TO FEEL ON THE MUGGY SIDE WITH DEW POINT EXPECTED TO REMAIN IN THE 60S BOTH DAYS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... TUESDAY NIGHT WILL SEE THE THREAT FOR SHOWERS AND EVENING THUNDERSTORMS AS A LEAD SHORT WAVE AHEAD OF THE APPROACHING UPPER TROF MOVES ACROSS THE REGION. UNSETTLED WEATHER WITH CONTINUED CHANCES FOR SHOWERS AND AFTERNOON THUNDERSTORMS WILL CONTINUE INTO THURSDAY EVENING AS THE TROF SWINGS ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. A COLD FRONT WILL CROSS THE REGION SATURDAY. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... NEAR TERM: IFR/LIFR FOR SOME OF THE TERMINALS(KPQI-KHUL) THIS MORNING DUE TO FOG. ACROSS KBGR AND KBHB, VFR ATTM. EXPECTING KBGR AND KBHB TO DROP TO MVFR AND THEN IFR LATER THIS MORNING INTO THE AFTERNOON AND HOLD AT IFR TONIGHT. THE NORTHERN TERMINALS WILL IMPROVE TO VFR AFTER 12Z AND STAY THERE THROUGH THE AFTERNOON. MVFR CONDITIONS ARRIVE ACROSS KHUL THIS EVENING AND THEN TO IFR BY MIDNIGHT W/KPQI-KCAR-KFVE DROPPING TO MVFR BY LATE EVENING AND THEN IFR OVERNIGHT. TSTMS W/CLOUD TO GROUND LIGHTNING AND HEAVY RAINFALL ARE POSSIBLE THIS AFTERNOON INTO TONIGHT. SHORT TERM: VFR CONDITIONS WILL PREVAIL MOST OF THE TIME BUT MVFR/IFR IS POSSIBLE IN PATCHY NIGHTTIME/EARLY MORNING FOG AS WELL AS SCT SHOWERS/TSTMS. && .MARINE... NEAR TERM: A 3 FOOT SWELLS OUT ON THE WATERS ATTM IS EXPECTED TO BUILD TO AROUND 4 FT THIS AFTERNOON. SWELLS ARE EXPECTED TO BUILD TO A RANGE OF 4-5 FT TONIGHT. WINDS WILL REMAIN LIGHT 10 KTS OR LESS RIGHT INTO TONIGHT. FOG WILL HAMPER NAVIGATION FROM TIME TO TIME. TSTMS ARE POSSIBLE LATER THIS AFTERNOON INTO THE EVENING. SHORT TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVEL. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HASTINGS/HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HASTINGS/HEWITT/DUDA MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
951 AM EDT SUN AUG 23 2015 .SYNOPSIS... THE STALLED FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT TODAY THROUGH MONDAY. A SLOW MOVING FRONTAL SYSTEM IS EXPECTED APPROACH THE REGION FROM THE WEST ON TUESDAY AND CROSS THE AREA ON WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... 950 AM UPDATE...SHOWERS ARE HAVING A HARD TIME MAKING TOO ONSHORE THIS MORNING, LIKELY DUE TO DRIER AIR NORTH OF THE SURFACE BOUNDARY WHICH STILL LIES OFF THE COAST. HAVE SLOWED THE ARRIVAL OF SHOWERS THIS MORNING ACCORDINGLY. HAVE ALSO MADE ADJUSTMENTS TO HIGH TEMPERATURES ACROSS DOWNEAST AS SOME AREAS HAVE SEEN MORE SUN THAN PREVIOUSLY EXPECTED, ALLOWING TEMPERATURES TO RISE MORE QUICKLY. OTHERWISE THE FORECAST PRETTY MUCH REMAINS THE SAME. PERVIOUS DISCUSSION...SURFACE ANALYSIS SHOWED TROF OR WEAK FRONTAL BOUNDARY DRAPED ACROSS THE DOWNEAST REGION. THIS FEATURE IS FORECAST TO LIFT NORTHWARD TODAY W/MORE HUMID AIR OVERSPREADING THE REGION AS LOW PRES LIFTS NE ACROSS THE WESTERN ATLC. THE 00Z NAM AND HRRR 3KM HAD THINGS INITIALIZED WELL. USED THIS BLEND FOR TODAY`S FORECAST W/PRECIP LIFTING FROM S TO N. SHOWERS WILL MOVE FROM S TO N TODAY. HIGH PRES ANCHORED OVER THE NW ATLC WILL ACT AS A BLOCK INITIALLY AS PRECIP DIES OUT HITTING A DRY AND STABLE AIRMASS IN PLACE ACROSS THE NORTH AND WEST. FURTHER S ACROSS CENTRAL AND DOWNEAST AREAS, SOUNDING DATA SHOWED THE COLUMN MOISTENING THROUGH 700MBS W/INCREASING INSTABILITY. SB CAPES OF 500-1000 JOULES ARE FORECAST TO SETUP THIS AFTERNOON ACROSS THE AFOREMENTIONED AREAS. PWATS ARE 1.7+ W/LIS DOWN TO -2 TO -3. 0-6KM SHEAR IS WEAK < 10 KTS. A WARM CLOUD LAYER W/HIGH FREEZING LEVELS(13-14K FT) WILL LEAD TO LOADING OF PRECIP W/POTENTIAL FOR HEAVY TO TORRENTIAL RAINFALL IN SPOTS. DECIDED TO STAY W/TSTMS THIS AFTERNOON INTO THE EVENING AND ADDED HEAVY RAINFALL WORDING. SHOWERS AND SOME TSTMS ARE EXPECTED TO SPREAD INTO NORTHERN AND WESTERN MAINE TONIGHT. SOUNDING DATA SHOWED MOST OF THE CONVECTION TO BE ELEVATED W/THE HIGHEST THREAT ACROSS THE HOULTON AND MILLINOCKET REGION W/LESS INSTABILITY FURTHER N. ONCE AGAIN HEAVY RAIN THREAT CONTINUES. DOWNEAST AND COASTAL AREAS WILL BECOME MORE STABLE W/FOG AND DRIZZLE. USED A CONSENSUS BLEND ON THE QPF DUE TO LOW CONFIDENCE IN PLACEMENT OF HEAVIER RAINFALL AMOUNTS. SOME AREAS COULD DEFINITELY PICK AN INCH OR MORE OF RAIN IN TSTMS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... UNSETTLED WX PATTERN CONTINUES FOR THE START OF THE WORK WEEK. EXPECT THE CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS BOTH MONDAY AND AGAIN ON TUESDAY AS A TROF OF LOW PRESSURE TRACKS SLOWLY EAST FROM THE GREAT LAKES REGION. HIGH TEMPERATURES BOTH MONDAY AND TUESDAY WILL RANGE FROM THE MID TO UPPER 70S. IT WILL ALSO CONTINUE TO FEEL ON THE MUGGY SIDE WITH DEW POINT EXPECTED TO REMAIN IN THE 60S BOTH DAYS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... TUESDAY NIGHT WILL SEE THE THREAT FOR SHOWERS AND EVENING THUNDERSTORMS AS A LEAD SHORT WAVE AHEAD OF THE APPROACHING UPPER TROF MOVES ACROSS THE REGION. UNSETTLED WEATHER WITH CONTINUED CHANCES FOR SHOWERS AND AFTERNOON THUNDERSTORMS WILL CONTINUE INTO THURSDAY EVENING AS THE TROF SWINGS ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. A COLD FRONT WILL CROSS THE REGION SATURDAY. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... NEAR TERM: IFR/LIFR FOR SOME OF THE TERMINALS(KPQI-KHUL) THIS MORNING DUE TO FOG. ACROSS KBGR AND KBHB, VFR ATTM. EXPECTING KBGR AND KBHB TO DROP TO MVFR AND THEN IFR LATER THIS MORNING INTO THE AFTERNOON AND HOLD AT IFR TONIGHT. THE NORTHERN TERMINALS WILL IMPROVE TO VFR AFTER 12Z AND STAY THERE THROUGH THE AFTERNOON. MVFR CONDITIONS ARRIVE ACROSS KHUL THIS EVENING AND THEN TO IFR BY MIDNIGHT W/KPQI-KCAR-KFVE DROPPING TO MVFR BY LATE EVENING AND THEN IFR OVERNIGHT. TSTMS W/CLOUD TO GROUND LIGHTNING AND HEAVY RAINFALL ARE POSSIBLE THIS AFTERNOON INTO TONIGHT. SHORT TERM: VFR CONDITIONS WILL PREVAIL MOST OF THE TIME BUT MVFR/IFR IS POSSIBLE IN PATCHY NIGHTTIME/EARLY MORNING FOG AS WELL AS SCT SHOWERS/TSTMS. && .MARINE... NEAR TERM: A 3 FOOT SWELLS OUT ON THE WATERS ATTM IS EXPECTED TO BUILD TO AROUND 4 FT THIS AFTERNOON. SWELLS ARE EXPECTED TO BUILD TO A RANGE OF 4-5 FT TONIGHT. WINDS WILL REMAIN LIGHT 10 KTS OR LESS RIGHT INTO TONIGHT. FOG WILL HAMPER NAVIGATION FROM TIME TO TIME. TSTMS ARE POSSIBLE LATER THIS AFTERNOON INTO THE EVENING. SHORT TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVEL. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HASTINGS/HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HASTINGS/HEWITT/DUDA MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
651 AM EDT SUN AUG 23 2015 .SYNOPSIS... THE STALLED FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT TODAY THROUGH MONDAY. A SLOW MOVING FRONTAL SYSTEM IS EXPECTED APPROACH THE REGION FROM THE WEST ON TUESDAY AND CROSS THE AREA ON WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... 645 AM UPDATE...ADJUSTED THE POPS AND SHOWERS BACK BY A FEW HRS THIS MORNING AS THE RADAR SHOWED SHOWERS MOVING IN FROM THE GULF OF MAINE DISSIPATING AS THEY MOVE N. MORE SHOWERS BEGINNING TO MAKE THEIR WAY TO THE COAST AND LOOK AS THOUGH THEY WILL HOLD TOGETHER AS THEY MOVE INLAND. KEPT FOG IN A FEW HRS LONGER AS SOME OBS SHOWED VSBYS DOWN 1SM OR LESS IN FOG. FOG SHOULD DISSIPATE AFTER 8 AM. SURFACE ANALYSIS SHOWED TROF OR WEAK FRONTAL BOUNDARY DRAPED ACROSS THE DOWNEAST REGION. THIS FEATURE IS FORECAST TO LIFT NORTHWARD TODAY W/MORE HUMID AIR OVERSPREADING THE REGION AS LOW PRES LIFTS NE ACROSS THE WESTERN ATLC. THE 00Z NAM AND HRRR 3KM HAD THINGS INITIALIZED WELL. USED THIS BLEND FOR TODAY`S FORECAST W/PRECIP LIFTING FROM S TO N. SHOWERS WILL MOVE FROM S TO N TODAY. HIGH PRES ANCHORED OVER THE NW ATLC WILL ACT AS A BLOCK INITIALLY AS PRECIP DIES OUT HITTING A DRY AND STABLE AIRMASS IN PLACE ACROSS THE NORTH AND WEST. FURTHER S ACROSS CENTRAL AND DOWNEAST AREAS, SOUNDING DATA SHOWED THE COLUMN MOISTENING THROUGH 700MBS W/INCREASING INSTABILITY. SB CAPES OF 500-1000 JOULES ARE FORECAST TO SETUP THIS AFTERNOON ACROSS THE AFOREMENTIONED AREAS. PWATS ARE 1.7+ W/LIS DOWN TO -2 TO -3. 0-6KM SHEAR IS WEAK < 10 KTS. A WARM CLOUD LAYER W/HIGH FREEZING LEVELS(13-14K FT) WILL LEAD TO LOADING OF PRECIP W/POTENTIAL FOR HEAVY TO TORRENTIAL RAINFALL IN SPOTS. DECIDED TO STAY W/TSTMS THIS AFTERNOON INTO THE EVENING AND ADDED HEAVY RAINFALL WORDING. SHOWERS AND SOME TSTMS ARE EXPECTED TO SPREAD INTO NORTHERN AND WESTERN MAINE TONIGHT. SOUNDING DATA SHOWED MOST OF THE CONVECTION TO BE ELEVATED W/THE HIGHEST THREAT ACROSS THE HOULTON AND MILLINOCKET REGION W/LESS INSTABILITY FURTHER N. ONCE AGAIN HEAVY RAIN THREAT CONTINUES. DOWNEAST AND COASTAL AREAS WILL BECOME MORE STABLE W/FOG AND DRIZZLE. USED A CONSENSUS BLEND ON THE QPF DUE TO LOW CONFIDENCE IN PLACEMENT OF HEAVIER RAINFALL AMOUNTS. SOME AREAS COULD DEFINITELY PICK AN INCH OR MORE OF RAIN IN TSTMS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... UNSETTLED WX PATTERN CONTINUES FOR THE START OF THE WORK WEEK. EXPECT THE CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS BOTH MONDAY AND AGAIN ON TUESDAY AS A TROF OF LOW PRESSURE TRACKS SLOWLY EAST FROM THE GREAT LAKES REGION. HIGH TEMPERATURES BOTH MONDAY AND TUESDAY WILL RANGE FROM THE MID TO UPPER 70S. IT WILL ALSO CONTINUE TO FEEL ON THE MUGGY SIDE WITH DEW POINT EXPECTED TO REMAIN IN THE 60S BOTH DAYS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... TUESDAY NIGHT WILL SEE THE THREAT FOR SHOWERS AND EVENING THUNDERSTORMS AS A LEAD SHORT WAVE AHEAD OF THE APPROACHING UPPER TROF MOVES ACROSS THE REGION. UNSETTLED WEATHER WITH CONTINUED CHANCES FOR SHOWERS AND AFTERNOON THUNDERSTORMS WILL CONTINUE INTO THURSDAY EVENING AS THE TROF SWINGS ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. A COLD FRONT WILL CROSS THE REGION SATURDAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... NEAR TERM: IFR/LIFR FOR SOME OF THE TERMINALS(KPQI-KHUL) THIS MORNING DUE TO FOG. ACROSS KBGR AND KBHB, VFR ATTM. EXPECTING KBGR AND KBHB TO DROP TO MVFR AND THEN IFR LATER THIS MORNING INTO THE AFTERNOON AND HOLD AT IFR TONIGHT. THE NORTHERN TERMINALS WILL IMPROVE TO VFR AFTER 12Z AND STAY THERE THROUGH THE AFTERNOON. MVFR CONDITIONS ARRIVE ACROSS KHUL THIS EVENING AND THEN TO IFR BY MIDNIGHT W/KPQI-KCAR-KFVE DROPPING TO MVFR BY LATE EVENING AND THEN IFR OVERNIGHT. TSTMS W/CLOUD TO GROUND LIGHTNING AND HEAVY RAINFALL ARE POSSIBLE THIS AFTERNOON INTO TONIGHT. SHORT TERM: VFR CONDITIONS WILL PREVAIL MOST OF THE TIME BUT MVFR/IFR IS POSSIBLE IN PATCHY NIGHTTIME/EARLY MORNING FOG AS WELL AS SCT SHOWERS/TSTMS. && .MARINE... NEAR TERM: A 3 FOOT SWELLS OUT ON THE WATERS ATTM IS EXPECTED TO BUILD TO AROUND 4 FT THIS AFTERNOON. SWELLS ARE EXPECTED TO BUILD TO A RANGE OF 4-5 FT TONIGHT. WINDS WILL REMAIN LIGHT 10 KTS OR LESS RIGHT INTO TONIGHT. FOG WILL HAMPER NAVIGATION FROM TIME TO TIME. TSTMS ARE POSSIBLE LATER THIS AFTERNOON INTO THE EVENING. SHORT TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVEL. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT/DUDA MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
433 AM EDT SUN AUG 23 2015 .SYNOPSIS... THE STALLED FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT TODAY THROUGH MONDAY. A SLOW MOVING FRONTAL SYSTEM IS EXPECTED APPROACH THE REGION FROM THE WEST ON TUESDAY AND CROSS THE AREA ON WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... CHALLENGE THIS TERM WILL BE TSTMS AND HEAVY RAIN POTENTIAL. THE LATEST RADAR LOOP SHOWED WIDELY SCATTERED SHOWERS MOVING NORTH ACROSS THE COASTAL AREAS FROM THE GULF OF MAINE. THESE SHOWERS WERE DISSIPATED AS THEY MOVED INTO DRIER AIR ACROSS CENTRAL AND NORTHERN MAINE. SOME FOG HAD SETUP MAINLY AWAY FROM THE COAST AS CLEARING, COOLING AND WET GROUND ALLOWED FOR THE FOG DEVELOPMENT. KEPT FOG IN THE FORECAST THROUGH EARLY MORNING. SURFACE ANALYSIS SHOWED TROF OR WEAK FRONTAL BOUNDARY DRAPED ACROSS THE DOWNEAST REGION. THIS FEATURE IS FORECAST TO LIFT NORTHWARD TODAY W/MORE HUMID AIR OVERSPREADING THE REGION AS LOW PRES LIFTS NE ACROSS THE WESTERN ATLC. THE 00Z NAM AND HRRR 3KM HAD THINGS INITIALIZED WELL. USED THIS BLEND FOR TODAY`S FORECAST W/PRECIP LIFTING FROM S TO N. SHOWERS WILL MOVE FROM S TO N TODAY. HIGH PRES ANCHORED OVER THE NW ATLC WILL ACT AS A BLOCK INITIALLY AS PRECIP DIES OUT HITTING A DRY AND STABLE AIRMASS IN PLACE ACROSS THE NORTH AND WEST. FURTHER S ACROSS CENTRAL AND DOWNEAST AREAS, SOUNDING DATA SHOWED THE COLUMN MOISTENING THROUGH 700MBS W/INCREASING INSTABILITY. SB CAPES OF 500-1000 JOULES ARE FORECAST TO SETUP THIS AFTERNOON ACROSS THE AFOREMENTIONED AREAS. PWATS ARE 1.7+ W/LIS DOWN TO -2 TO -3. 0-6KM SHEAR IS WEAK < 10 KTS. A WARM CLOUD LAYER W/HIGH FREEZING LEVELS(13-14K FT) WILL LEAD TO LOADING OF PRECIP W/POTENTIAL FOR HEAVY TO TORRENTIAL RAINFALL IN SPOTS. DECIDED TO STAY W/TSTMS THIS AFTERNOON INTO THE EVENING AND ADDED HEAVY RAINFALL WORDING. SHOWERS AND SOME TSTMS ARE EXPECTED TO SPREAD INTO NORTHERN AND WESTERN MAINE TONIGHT. SOUNDING DATA SHOWED MOST OF THE CONVECTION TO BE ELEVATED W/THE HIGHEST THREAT ACROSS THE HOULTON AND MILLINOCKET REGION W/LESS INSTABILITY FURTHER N. ONCE AGAIN HEAVY RAIN THREAT CONTINUES. DOWNEAST AND COASTAL AREAS WILL BECOME MORE STABLE W/FOG AND DRIZZLE. USED A CONSENSUS BLEND ON THE QPF DUE TO LOW CONFIDENCE IN PLACEMENT OF HEAVIER RAINFALL AMOUNTS. SOME AREAS COULD DEFINITELY PICK AN INCH OR MORE OF RAIN IN TSTMS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... UNSETTLED WX PATTERN CONTINUES FOR THE START OF THE WORK WEEK. EXPECT THE CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS BOTH MONDAY AND AGAIN ON TUESDAY AS A TROF OF LOW PRESSURE TRACKS SLOWLY EAST FROM THE GREAT LAKES REGION. HIGH TEMPERATURES BOTH MONDAY AND TUESDAY WILL RANGE FROM THE MID TO UPPER 70S. IT WILL ALSO CONTINUE TO FEEL ON THE MUGGY SIDE WITH DEW POINT EXPECTED TO REMAIN IN THE 60S BOTH DAYS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... TUESDAY NIGHT WILL SEE THE THREAT FOR SHOWERS AND EVENING THUNDERSTORMS AS A LEAD SHORT WAVE AHEAD OF THE APPROACHING UPPER TROF MOVES ACROSS THE REGION. UNSETTLED WEATHER WITH CONTINUED CHANCES FOR SHOWERS AND AFTERNOON THUNDERSTORMS WILL CONTINUE INTO THURSDAY EVENING AS THE TROF SWINGS ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. A COLD FRONT WILL CROSS THE REGION SATURDAY. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... NEAR TERM: IFR/LIFR FOR SOME OF THE TERMINALS(KPQI-KHUL) THIS MORNING DUE TO FOG. ACROSS KBGR AND KBHB, VFR ATTM. EXPECTING KBGR AND KBHB TO DROP TO MVFR AND THEN IFR LATER THIS MORNING INTO THE AFTERNOON AND HOLD AT IFR TONIGHT. THE NORTHERN TERMINALS WILL IMPROVE TO VFR AFTER 12Z AND STAY THERE THROUGH THE AFTERNOON. MVFR CONDITIONS ARRIVE ACROSS KHUL THIS EVENING AND THEN TO IFR BY MIDNIGHT W/KPQI-KCAR-KFVE DROPPING TO MVFR BY LATE EVENING AND THEN IFR OVERNIGHT. TSTMS W/CLOUD TO GROUND LIGHTNING AND HEAVY RAINFALL ARE POSSIBLE THIS AFTERNOON INTO TONIGHT. SHORT TERM: VFR CONDITIONS WILL PREVAIL MOST OF THE TIME BUT MVFR/IFR IS POSSIBLE IN PATCHY NIGHTTIME/EARLY MORNING FOG AS WELL AS SCT SHOWERS/TSTMS. && .MARINE... NEAR TERM: A 3 FOOT SWELLS OUT ON THE WATERS ATTM IS EXPECTED TO BUILD TO AROUND 4 FT THIS AFTERNOON. SWELLS ARE EXPECTED TO BUILD TO A RANGE OF 4-5 FT TONIGHT. WINDS WILL REMAIN LIGHT 10 KTS OR LESS RIGHT INTO TONIGHT. FOG WILL HAMPER NAVIGATION FROM TIME TO TIME. TSTMS ARE POSSIBLE LATER THIS AFTERNOON INTO THE EVENING. SHORT TERM: WIND/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVEL. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT/DUDA MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1250 AM EDT SUN AUG 23 2015 .SYNOPSIS... THE STALLED FRONT IS EXPECTED TO RETURN NORTH AS A WARM FRONT TODAY THROUGH MONDAY. && .NEAR TERM /THROUGH TODAY/... 1230 AM UPDATE: SOME SHOWERS MOVING ACROSS THE OUTER ISLANDS OF THE COAST PER THE LATEST RADAR LOOP. DECIDED TO BRING POPS AND TIMING UP A BIT BASED ON THE LATEST RADAR. THE RAP & HRRR 3KM MODEL DOING OK W/THIS SETUP. MESO ANALYSIS SHOWED AN INVERTED TROF ALIGNED ACROSS THE COAST NOSING UP INTO EASTERN SECTION. LAPS DATA HAD SOME LLVL CONVERGENCE IN THE AFOREMENTIONED REGION WHICH WILL ALLOW SHOWERS TO STAY IN TACT. ATMOSPHERE LOOKS TOO STABLE FOR TSTMS ATTM PER THE LAPS SHOWING LIFTED INDICES ABOVE 0. SOME FOG SHOWING UP ON THE COAST AND INLAND AS WELL. DAYCREW HAD THIS HANDLED WELL. ADJUSTED THE HRLY TEMPS TO BRING THEM UP SOME ACROSS THE DOWNEAST AND COAST GIVEN CLOUDS AND SHOWERS. FURTHER N AND W, BASICALLY CLEAR W/READINGS IN THE MID TO UPPER 50S. FRONTAL BOUNDARY WILL BEGIN TO LIFT BACK NORTH THROUGH TODAY. HAVE NOTED THE 12Z GUIDANCE WAS FASTER IN BRINGING THIS FRONT THROUGH, SO HAVE SHIFTED THE CHANCES FOR SHOWERS FURTHER NORTH BY THE AFTERNOON; MAINLY ALONG AND SOUTH OF A HOULTON TO GREENVILLE LINE. SB CAPES ARE PROGGED TO REACH 800-1200 J/KG, SO THUNDERSTORMS WILL BE A POSSIBILITY AWAY FROM THE COAST. 0-6KM SHEAR ISN`T ALL THAT IMPRESSIVE, SO STRONG STORMS AREN`T EXPECTED. HOWEVER, PWATS WILL ONCE AGAIN INCREASE TO 1.75 INCHES OR MORE ON THE SOUTH SIDE OF THE FRONT, SO HEAVY RAIN WILL BE A THREAT. STEERING FLOW WILL BE FAIRLY LIGHT, SO SLOW MOVING CELLS WILL BE A CONCERN. HIGHS WILL MAINLY BE IN THE UPPER 70S TO AROUND 80. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... THE FA WILL REMAIN IN A BROAD SW TO NE FLOW REGIME HI ALF AHEAD OF A STRONG UPPER TROF/CLOSED LOW OVR THE MIDWEST FROM SUN NGT THRU TUE...WITH SEVERAL WEAK S/WV IMPULSES TO IMPACT THE FA. FOR THIS REASON...WE DO NOT LOWER POPS BLO CHC EVEN DURG THE LATE NGT AND MORN HRS...BUT WE DO INCREASE POPS INTO THE LIKELY CATEGORY DURG THE LATE AFTN AND ERLY EVE HRS MON AND TUE TO ACCOUNT FOR SOME DIURNAL HTG ADDING TO SBCAPES WHICH COULD REACH AS HI AS 600 TO 1000 J/KG. FOR THIS REASON...WE ADDED CHC TSTMS WITH CHC AND ABV POPS DURG THESE HRS. ALTHOUGH WE DO NOT ADVERTISE ENHANCED WORDING FOR HVY RNFL ATTM...IT WILL LIKELY BE INCLUDED ONCE THIS PTN OF THE FCST APCHS THE NEAR TERM...GIVEN THE POTENTIAL HI PWATS AND THE DIFFLUENT FLOW ALF PATTERN WHICH BOTH FAVOR DEEP ENOUGH CNVCTN FOR HI RNFL RATES WITH SHWRS/TSTMS. HI AND LOW TEMPS WILL CONT ABV AVG...BUT WILL SLOWLY TAPER BACK TO CLOSER TO NORMAL SEASONAL VALUES BY TUE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A SLOW MOVING UPPER LEVEL TROUGH WILL APPROACH FROM THE GREAT LAKES DURING THE MID WEEK PERIOD THEN SLOWLY TRACK ACROSS THE REGION THROUGH THURSDAY BRINGING UNSETTLED WEATHER. TUESDAY NIGHT AND WEDNESDAY WILL BE MOSTLY CLOUDY WITH SOME SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM, ESPECIALLY ACROSS CENTRAL AND NORTHERN AREAS. CLOUDS AND SCATTERED SHOWERS WILL CONTINUE INTO THURSDAY OVER CENTRAL AND NORTHERN AREAS WHILE THE DOWNEAST REGION MAY HAVE SOME BREAKS OF SUNSHINE. THE TROUGH SHOULD WEAKEN AND MOVE OUT TO THE NORTHEAST ON FRIDAY ALLOWING WEAK SURFACE RIDGING TO BRING PARTIAL CLEARING OVER THE AREA AND SEASONABLE TEMPS. THE DRY WEATHER MAY LAST INTO SATURDAY BEFORE ENOUGH TROUGH, DIGGING DOWN FROM CENTRAL CANADA, APPROACHES WITH A CHANCE FOR SHOWERS ON SUNDAY. && .AVIATION /04Z SUNDAY THROUGH THURSDAY/... NEAR TERM: 1030PM UPDATE: GIVEN IFR CIGS AT KRKD AND LOWERING CIGS VISIBLE ALONG THE COAST ON WEBCAMS BEFORE SUNSET, EXPECT THAT CONDITIONS ARE LOWERING AT KBHB. OTHERWISE, PATCHY FOG HAS BEEN NOTED IN INTERIOR AREAS, BUT NOT CURRENTLY EXPECTED TO BE PREVAILING CONDITIONS OUTSIDE OF COASTAL AND DOWN EAST AREAS. MAINTAIN VFR CONDITIONS FOR 4 NORTHERN TERMINALS. 730PM UPDATE: KBHB OBS STILL DOWN, SO USED OBS FM OTHER COASTAL ZONE SITES TO ESTIMATE SOME BORDERLINE MVFR CIGS CURRENTLY. EXPECT AT LEAST IFR CIGS TO DEVELOP FOR KBHB, AND IFR VIS IS CERTAINLY A POSSIBILITY. EXPECT MVFR CIGS AND BORDERLINE IFR VIS IN KBGR BY 06Z, WITH IMPROVEMENT AT BOTH SRN TERMINALS AFTER SUNRISE. KEPT VFR CONDITIONS AT NRN TERMINALS THROUGH THE PERIOD, AND KEPT RAIN OUT OF NRN SITES, EXCEPT SHWRS AT KHUL LATER IN THE AFTERNOON. ORIGINAL DISCUSSION: VFR CONDITIONS AT THE NORTHERN TERMINALS THROUGH THE PERIOD, THOUGH SOME MVFR IN LOCALIZED FOG LATE TONIGHT/EARLY SUNDAY. KBHB AND KBGR WILL ONCE AGAIN DROP TO IFR/LIFR AFTER 06Z TONIGHT IN FOG. SHORT TERM: THE AVG CLG/VSBY FOR THIS PTN OF THE FCST FROM SUN NGT THRU TUE WILL BE MVFR FOR ALL THE TAF SITES WITH PERIODIC SHWRS... LIKELY LOWERING TO IFR LATE AT NGT WITH PATCHY FOG...AND POSSIBLE RISING TO AS HIGH AS LOW VFR BETWEEN SHWRS DURING AFTN AND ERLY EVE HRS. && .MARINE... NEAR TERM: NO HEADLINES WILL BE NEEDED ACROSS THE WATERS TONIGHT OR SUNDAY. THE CONCERN REMAINS AREAS OF DENSE FOG, WHICH WILL REDUCE VISIBILITY TO BELOW 1SM AT TIMES. SHORT TERM: NO HDLNS ANTICIPATED ATTM...ALTHOUGH WV HTS COULD APCH 5 FT OVR OUTER MOST WATERS LATE SUN NGT THRU MON WITH A MDT SWELL COMPONENT. PATCHY...MSLY NGT AND MORN MARINE FOG CAN ALSO BE XPCTD. WE WENT WITH ABOUT 90 PERCENT OF WW3 WV GUIDANCE FOR THE OUTER MZS AND 65 TO 85 PERCENT FOR NEAR SHORE WATERS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
922 PM EDT MON AUG 24 2015 .SYNOPSIS... A COLD FRONT APPROACHING FROM THE WEST WILL CROSS THE MID ATLANTIC STATES TONIGHT. HIGH PRESSURE WILL GRADUALLY BUILD INTO THE AREA DURING THE MIDDLE OF THE WEEK AND BECOME CENTERED OVER THE AREA FOR THE START OF THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... WATCHING ONE CLUSTER OF THUNDERSTORMS WHICH STRENGTHENED OVER THE I-95 CORRIDOR NOW APPROACHING THE BAY. AIRMASS IS CHARACTERIZED BY SBCAPE OF 1000-1500 J/KG AND DEEP LAYER SHEAR AROUND 30 KT. THUS THERE HAS BEEN SOME ORGANIZATION...WHICH MAY HAVE BEEN ENHANCED BY A BOUNDARY SEEN LATE THIS AFTERNOON ON RADAR IN THIS AREA. CURRENTLY RADAR AND SATELLITE DO NOT INDICATE ANY FURTHER DEVELOPMENT BEHIND THE ONGOING CLUSTER. HOWEVER ACTUAL COLD FRONT IS STILL OVER THE MOUNTAINS (DEW POINTS STILL NEAR 70 IN PARTS OF THE NORTHERN SHENANDOAH VALLEY)...AND MESOANALYSIS INDICATES INSTBY STILL EXISTS AHEAD OF THE BOUNDARY. HRRR AND RAP HAVE BEEN CONSISTENT WITH DEVELOPING MORE ACTIVITY AHEAD OF THE FRONT. HOWEVER AM NOT TERRIBLY CONFIDENT IN THESE SOLUTIONS...BUT WILL CONTINUE TO MONITOR THE TRENDS. IF ADDITIONAL ACTIVITY WERE TO DEVELOP...IT MAY NOT EXIT FAR SOUTHERN MD UNTIL VERY LATE TONIGHT. WILL ALSO HAVE TO WATCH FOR PATCHY FOG DEPENDING ON TIMING OF CLEARING/DRIER DEW POINTS. COOLEST READINGS TONIGHT WILL LIKELY BE OUT WEST...WITH A MORE MUDDLED PICTURE OF 60S TO LOWER 70S IN THE EAST. HIGH PRESSURE SLOWLY BUILDS IN ON TUESDAY AS THE FRONT STALLS TO OUR SOUTHEAST. SOME PATCHY CLOUDS WILL BE AROUND BUT FOR THE MOST PART SUN WILL PREVAIL...AND DEW POINTS SHOULD REMAIN VERY LOW... IN THE LOW-MID 50S FOR THE MOST OF THE REGION. HIGH TEMPERATURES WILL ALSO BE COOLER WITH A TROUGH OF LOW PRESSURE CENTERED NEARBY ALOFT...WITH MOST READINGS 5-8 DEGREES BELOW THE HIGHS WE WILL REACH TODAY. OVERALL...A VERY NICE LATE AUGUST DAY. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... HIGH PRESSURE PERSISTS ACROSS THE UPPER MID-WEST INTO THE MID- ATLANTIC TUESDAYS NIGHT THROUGH WEDNESDAY NIGHT. LIGHT NRLY FLOW WILL PERSIST AT THE SURFACE RESULTING IN DRY CONDITIONS WITH TEMPS BARELY REACHING THE UPPER 70S AT HIGHER ELEVATIONS ALONG AND WEST OF THE BLUE RIDGE AND IN THE LOW 80S NEAR THE METROS ON WEDNESDAY. && .LONG TERM /THURSDAY THROUGH MONDAY/... SFC HIGH PRESSURE DOMINATES THE WEATHER PATTERN THROUGH THE LONG TERM...WITH LITTLE DAY-TO-DAY VARIABILITY IN SENSIBLE WEATHER AND LITTLE-TO-NO CHANCE OF MEANINGFUL PRECIPITATION. FULL LATE SUMMER INSOLATION WILL LEAD TO A SLOW INCREASE IN TEMPERATURES EACH DAY AS AIRMASS MODIFIES...WITH TEMPERATURES AOA NORMAL BY SATURDAY AND A FEW DEGREES WARMER...U80S/L90S...ACROSS THE ENTIRE CWA BY SUNDAY. DEWPOINTS REMAIN RELATIVELY LOW THROUGH THE END OF THE WEEK WITH L/M50S ACROSS THE CWA...WHICH WILL KEEP NIGHTTIME TEMPERATURES IN 50S/L60S...THOUGH THERE COULD BE A FEW ISOLATED SPOTS IN OUR FAR WEST WITH LOWS IN THE M/U40S FRIDAY MORNING. WEAK RETURN FLOW BEGINS OVER THE WEEKEND...BUT WITH QUALITY MOISTURE SHUNTED WELL SOUTH AND EAST OF OUR AREA...DEWPOINTS EXPECTED TO ONLY INCREASE INTO THE L60S...SO EVEN WITH TEMPERATURES IN L90S...HEAT INDICES WILL REMAIN AOB 85. ESSENTIALLY NO CHANCE OF PRECIP THURSDAY OR FRIDAY. SFC HIGH WEAKENS ITS GRIP SLIGHTLY OVER THE WEEKEND AND WITH WEAK MOISTURE RETURN...COULD BE A FEW SHOWERS/STORMS AROUND...THOUGH COVERAGE SHOULD BE ISOLATED AND MAINLY CONFINED TO HIGHER TERRAIN. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... AS OF 01Z...HEAVY STORMS ARE EXITING THE BALTIMORE AREA. AT THIS TIME...NO ADDITIONAL STORMS ARE ON THE RADAR. HOWEVER COLD FRONT IS STILL TO THE WEST...AND THEREFORE CANNOT TOTALLY RULE OUT ADDITIONAL STORMS LATE THIS EVENING. HOWEVER GIVEN STRENGTH OF CURRENT STORMS...AM NOT CONFIDENT IF THESE WOULD DEVELOP OVER THE METRO AREAS...ALTHOUGH SOME MODELS SUGGEST IT IS POSSIBLE. DO NOT HAVE ANY FOG IN THE TAFS AT THE MOMENT...BUT THERE COULD BE SOME IF CLEARING WORKS IN BEFORE DRIER LOW LEVEL AIR. WINDS WILL LIKELY BE SOMEWHAT VARIABLE UNTIL THE FRONT PASSES LATER TONIGHT...WHICH WILL ALLOW THEM TO BECOME MORE WESTERLY. OTHERWISE...VFR THROUGH THE REMAINDER OF THE PERIOD UNDER HIGH PRESSURE. && .MARINE... ONE AREA OF STRONG STORMS CROSSING THE NORTHERN BAY NOW. THIS IS THE MAIN CONCERN AT THE MOMENT...ALTHOUGH SOME ADDITIONAL STORMS MAY DEVELOP AHEAD OF AN APPROACHING COLD FRONT LATER TONIGHT. A FEW SOUTHERLY GUSTS TO AROUND 20 KT HAVE OCCURRED OUTSIDE THE STORMS...AND IT STILL LOOKS LIKE THERE WILL BE A PRESSURE SURGE WITH THE COLD FRONT LATER TONIGHT. MADE SOME MINOR ADJUSTMENTS TO THE SCA BASED ON LATEST GUIDANCE. HOWEVER IT STILL LOOKS LIKE THE WINDS WILL BEGIN TO DIMINISH TOWARD DAWN. WINDS EXPECTED TO REMAIN SUB-SCA THROUGH THE REMAINDER OF THE FORECAST PERIOD UNDER HIGH PRESSURE. && .TIDES/COASTAL FLOODING... STILL WATCHING TIDAL ANOMALIES CLOSELY WITH POTENTIAL FOR MINOR FLOODING WITH THE SOUTHERLY UP-BAY FLOW. HAVE ISSUED A COASTAL FLOOD ADVISORY FOR ANNAPOLIS TONIGHT AS A PERSISTENT ANOMALY WILL YIELD THE THRESHOLD. HOWEVER THIS COULD BE DISRUPTED BY THE ONGOING STORMS. STRAITS POINT WILL ALSO BE VERY CLOSE TO MINOR FLOOD STAGE WITH THE UPCOMING HIGH TIDE CYCLE. WESTERLY WINDS BEHIND A COLD FRONT LATE TONIGHT WILL HELP DECREASE THE ANOMALIES. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 4 AM EDT TUESDAY FOR MDZ014. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ533-534-537- 541-543. SMALL CRAFT ADVISORY FROM 1 AM TO 6 AM EDT TUESDAY FOR ANZ542. SMALL CRAFT ADVISORY UNTIL 1 AM EDT TUESDAY FOR ANZ531-532. && $$ SYNOPSIS...RCM NEAR TERM...ADS/RCM SHORT TERM...HAS/RCM LONG TERM...MSE AVIATION...ADS/HAS/MSE/RCM MARINE...ADS/HAS/MSE/RCM TIDES/COASTAL FLOODING...ADS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
736 PM EDT MON AUG 24 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 440 PM EDT MON AUG 24 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN UNSEASONABLY DEEP MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION WITH 500MB HEIGHT ANOMALIES OF 2.5 STANDARD DEVIATIONS BELOW THE LONG TERM LATE AUG AVG. SEVERAL SHORTWAVES ARE ROTATING AROUND THE CIRCULATION. ONE IS JUST E OF LAKE SUPERIOR...ANOTHER IS NEAR LAKE NIPIGON AND A THIRD IS MOVING ACROSS WRN UPPER MI. SHRA HAD NOT BEEN AS NMRS AS EXPECTED OVER UPPER MI UNTIL RECENTLY WHEN SHORTWAVE REACHED WRN UPPER MI. FOR MUCH OF THE DAY OVER LAKE SUPERIOR...THERE HAD BEEN A RATHER SOLID BAND OF SHRA...EXTENDING FROM AROUND LAKE NIPIGON SE AND E TO ERN LAKE SUPERIOR IN SHARP CYCLONIC FLOW/ZONE OF WAA/RATHER FOCUSED THETA-E ADVECTION. 850MB THERMAL TROF WITH 850MB TEMPS AS LOW AS 1C AT KINL PER 12Z RAOBS RUNS FROM NRN MN INTO NRN WI/SRN UPPER MI AND TOWARD LWR MI. ON LATEST WATER VAPOR IMAGERY...SHORTWAVE NEAR LAKE NIPIGON LOOKS QUITE VIGOROUS...AND CANADIAN RADARS SHOW DECENT SHIELD OF SHRA ADVANCING S WITH FEATURE. THUS...EXPECT ANOTHER INCREASE IN SHRA COVERAGE OVER THE W IN THE NEXT FEW HRS. MEANWHILE...SHORTWAVE CURRENTLY MOVING ACROSS WRN UPPER MI WILL SPREAD INCREASED SHRA ACTIVITY EASTWARD INTO THE ERN FCST AREA. AT THE SAME TIME... VEERING WINDS WILL HELP PUSH THE SHRA OVER THE ERN LAKE SE INTO THE ERN FCST AREA AS WELL. LAKE NIPIGON SHORTWAVE WILL THEN CONTINUE TO AID SHRA ACTIVITY OVER THE E THRU LATE EVENING INTO AT LEAST THE EARLY OVERNIGHT. OTHERWISE...DEEP CYCLONIC FLOW AND WEAK WAA WILL CONTINUE TO SUPPORT SCT/NMRS SHRA OVERNIGHT. 850MB TEMPS WILL BE LOW ENOUGH...ESPECIALLY ALONG SRN PORTIONS OF LAKE SUPERIOR WHERE WARMEST WATER RESIDES...TO ADD A LAKE COMPONENT TO PCPN AS WELL. UPSLOPE COMPONENT TO PCPN WILL BE GREATEST OVER THE WRN FCST AREA. ALTHOUGH MID LEVEL LOW DRIFTS FARTHER E ON TUE AND HEIGHT RISES CONTINUE...LINGERING DEEP CYCLONIC FLOW/UPSLOPING AND SOME LAKE COMPONENT WILL KEEP SHRA GOING...ESPECIALLY IN THE AREAS NORMALLY FAVORED BY NW WINDS OFF LAKE SUPERIOR. HOWEVER...COVERAGE OF SHRA SHOULD TEND TO SHOW SOME DIMINISHING TREND DURING THE DAY. IT WILL BE ANOTHER UNSEASONABLY COOL DAY UNDER ABUNDANT CLOUD COVER. COOLEST CONDITIONS (MID 50S FOR MAX TEMPS) WILL BE ACROSS THE HIGHER TERRAIN AND WHERE PCPN IS MOST FREQUENT. NEW RECORD LOW MAX TEMPS MAY BE SET AT SOME LOCATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 429 PM EDT MON AUG 24 2015 DAMP AND FALL-LIKE CONDITIONS WILL GIVE WAY TO MODERATION TOWARD MORE SEASONAL WEATHER BY THU INTO THE WEEKEND. A DEEP CLOSED MID/UPPER LEVEL LOW SOUTH OF JAMES BAY WILL GRADUALLY FILL AND MOVE INTO QUEBEC WED. RIDGING WILL THEN PUSH BACK TOWARD THE WESTERN LAKES BY THU INTO THE WEEKEND. TUE NIGHT AND WED...AS THE MID LEVEL LOW SHIFTS TO THE EAST...MODELS SUGGEST THAT MAINLY NNW FLOW WITH 330-340 WINDS WILL PREVAIL WITH 850 MB TEMPS REMAINING AROUND 6C INTO EARLY WED. WITH THE NNW FLOW AND MOST FAVORABLE MOISTURE OVER THE CNTRL AND ERN LAKE...EXPECT THE GREATEST -SHRA COVERAGE INTO N CNTRL UPPER MI EVEN AS THE AMOUNTS DIMINISH. THE PCPN WILL DIMINISH AND END WED AS THE DEEP MOISTURE SHIFTS TO THE EAST. MAX TEMPS ARE EXPECTED REBOUND BACK INTO THE MID TO UPPER 60S. WED NIGHT INTO THU...WITH FAVORABLE RADIATIONAL COOLING CONDITIONS AS THE SFC RIDGE BUILDS INTO THE AREA AND PWAT VALUES BLO 0.5 INCH...EXPECT INLAND MIN TEMPS INTO THE MID 40S INLAND. ABUNDANT SUNSHINE THU SHOULD PUSH TEMPS BACK TO SEASONAL AVERAGES IN THE LOWER TO MID 70S. FRI-MON...UNCERTAINTY INCREASES DUE TO MODEL DIFFERENCES IN HANDLING THE POSITION OF THE SFC FRONT AND IMPACT OF A SHRTWV MOVING OUT OF THE PLAINS. THE ECMWF HAS BEEN THE MOST CONSISTENT IN KEEPING MOST OF THE PCPN WITH THIS FEATURE SOUTH AND WEST OF WI. THIS WOULD ALLOW A WEAK SFC FRONT/TROUGH TO SLIDE TOWARD OR INTO UPPER MI. THE FRONT COMBINED WITH THE POTENTIAL FOR WNW FLOW SHRTWVS SUPPORTS CONTINUED CHANCE SHRA/TSRA POPS FRI INTO FRI NIGHT. THE MODELS HAVE TRENDED AWAY FROM PCPN FOR SAT INTO MON AS THE MID LEVEL RIDGE BUILDS INTO THE REGION. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 735 PM EDT MON AUG 24 2015 A GUSTY NW FLOW OF COOL...MOIST AIR AROUND LOW PRES TO THE NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO KIWD/KCMX/KSAW THRU THE FCST PERIOD. IN GENERAL...KCMX WILL SEE THE WORST CONDITIONS...WITH MORE FREQUENT...HEAVIER SHRA AND SOME PERIODS OF IFR CONDITIONS AT TIMES DUE TO A MORE PRONOUNCED UPSLOPE WIND COMPONENT. ALSO EXPECT THE STRONGEST WINDS AT THE MORE EXPOSED KCMX TERMINAL. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 455 AM EDT MON AUG 24 2015 AN UNSEASONABLY DEEP LO PRES JUST N OF THUNDER BAY EARLY THIS MORNING WILL DRIFT SLOWLY TO THE ESE THRU TUE. UNDER THE SHARPER PRES GRADIENT ON THE SW FLANK OF THIS LO WHERE THE SURGE OF COOLER AIR IS MOST PRONOUNCED AND DESTABLIZATION IS GREATEST...WNW GALES UP TO 35 KTS WILL CONTINUE OVER THE SW HALF OF THE LAKE THRU THE AFTN. CANCELLED THE GALE WARNING FOR THE NCENTRAL PORTION OF THE LAKE AS THIS AREA HAS FALLEN UNDER A SLACKER GRADIENT CLOSER TO THE LO PRES. ADDED A MENTION OF WATERSPOUTS OVER THE EASTERN PORTION OF THE LAKE WHERE WATER TEMPERATURES ARE WARMEST AND WINDS MAY BE WEAKER FOR A TIME TODAY AHEAD OF AN APPROACHING LO PRES TROUGH MOVING AROUND THE LO JUST TO THE N. AS THE LO CONTINUES E OF LAKE SUPERIOR TONIGHT/TUE...NW GALES TO 35 KTS WILL BE POSSIBLE OVER MAINLY THE CENTRAL PORTION OF THE LAKE WHERE GUIDANCE HINTS THE PRES GRADIENT WILL BE SHARPEST. AS THE LO MOVES FARTHER TO THE E AND HI PRES TO THE W APPROACHES...THE PRES GRADIENT AND WINDS WILL DIMINISH W-E ON TUE NIGHT/WED. WINDS WILL BE UNDER 20 KTS FOR WED NIGHT THRU FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLB AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
444 PM EDT SUN AUG 23 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 401 PM EDT SUN AUG 23 2015 12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW POTENT SHRTWV/ CUTOFF H5 LO LIFTING NORTH OF THE MN ARROWHEAD THIS AFTERNOON INTO ONTARIO. THIS POTENT SYSTEM CAUSED 00Z-12Z H5 HGT FALLS OF 160M AT KINL AND 120-140M HGT FALLS OVER UPPER MI. STRONG UPPER DIFFLUENCE/DPVA AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF THIS FEATURE AND AHEAD OF THE ASSOCIATED COLD FRONTAL PASSAGE RESULTED IN A LINE OF HEAVY SHOWERS AND STRONG STORMS MOVING ACROSS UPPER MI THIS MORNING INTO THE AFTERNOON HOURS. THE MAIN LINE OF SHOWERS HAS EXITED E OF MOST OF THE CWA...BUT THERE WAS STILL SOME LINGERING SCATTERED SHOWERS AHEAD OF THE FRONTAL BOUNDARY WHICH WAS APPROXIMATELY ALONG A LINE FROM MUNISING TO GARDEN IN PAST HOUR. SOME SCATTERED SHOWERS WERE ALSO BEGINNING TO WORK INTO THE FAR WRN CWA THIS PAST HOUR WITH WRAPAROUND MOISTURE MOVING IN ON BACKSIDE OF ONTARIO LOW. TONIGHT AND MONDAY...SCATTERED SHOWERS OVER THE EASTERN THIRD OF THE CWA SHOULD END BETWEEN 22-00Z THIS EVENING AS FRONT EXITS THE AREA. ATTENTION WILL THEN TURN TO WRAPAROUND MOISTURE AND STRONG COLD ADVECTION ON THE BACKSIDE OF NEARLY VERICALLY STACKED LOW PRESSURE SYSTEM DRIFTING SLOWLY EAST FROM ONTARIO ACROSS THE UPPER GREAT LAKES REGION. THIS DEEPER MOISTURE AND COLD ADVECTION WILL LEAD TO LAKE ENHANCED RAIN SHOWERS FOR AREAS DOWNWIND OF LAKE SUPERIOR IN A WNW WIND FLOW. 8H TEMPS DROPPING TO 3C WEST AND 5-6C EAST LATE TONIGHT IN A WESTERLY FLOW WILL LEAD TO AN INCREASE IN COVERAGE OF LAKE EFFECT RAIN SHOWERS LATE TONIGHT OVER THE WRN U.P. AND EVEN CARRYING INTO THE HURON MOUNTAINS AS CONVECTIVE BOUNDARY LAYER WINDS INCREASE TOWARD 30KTS BEHIND THE SYSTEM. THE COLD ADVECTION WILL RESULT IN LAKE DELTA-T VALUES 10-13C SUFFICIENT FOR LAKE ENHANCED RAIN IN STRONGLY CYCLONIC WESTERLY FLOW. WILL CONTINUE LIKELY TO CATEGORICAL POPS OVER THESE AREAS TONIGHT INTO MONDAY. WINDS VEERING MORE NW DURING THE DAY ON MONDAY WILL BRING LAKE EFFECT RAIN SHOWERS INTO ERN COUNTIES OF UPPER MI SO HAVE CORRESPONDINGLY BUMPED UP POPS THERE TO HIGH LIKELY/CATEGORICAL ON MONDAY AS WELL. THE REST OF THE CWA WILL SEE ISOLD TO SCT LAKE EFFECT SHOWERS LATE TONIGHT INTO MONDAY. TEMPS WILL BE DROPPING QUICKLY TONIGHT WITH THE CAA IN THE WAKE OF THE SYSTEM. EXPECT LOWS RANGING FROM THE UPPER 40S INTERIOR WEST TO MID 50S NEAR THE GREAT LAKES SHORELINES. MONDAY WILL FEEL MORE LIKE OCTOBER AS TEMPS ONLY RISE A FEW DEGREES WITH MOST READINGS STAYING IN THE 50S. RECORD LOW MAXIMUM TEMPS ON MONDAY WILL BE IN JEOPARDY AT A NUMBER OF SITES. DEEP MIXING FROM COLD ADVECTION WILL ALLOW FOR BREEZY CONDITIONS ACROSS THE CWA THROUGH MUCH OF THE PERIOD. IT WILL BE WINDY OVER THE KEWEENAW PENINSULA (ESPECIALLY THE PORTAGE CANAL) WITH THE FAVORED WESTERLY WIND DIRECTION AND MORE UNSTABLE FLOW OFF LAKE SUPERIOR SO EXPECT THE POTENTIAL FOR WINDS GUSTING 35-40 MPH AT SOME OF THE MORE EXPOSED LOCATIONS OVER THE KEWEENAW. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 443 PM EDT SUN AUG 23 2015 DAMP AND FALL-LIKE CONDITIONS WILL GIVE WAY TO MODERATION TOWARD MORE SEASONAL WEATHER BY THU INTO THE WEEKEND. A DEEP CLOSED MID- UPPER LEVEL LOW JUST EAST OF LAKE SUPERIOR AT 00Z/TUE WILL GRAUDALLY FILL AND MOVE TO QUEBEC BY WED. RIDGING WILL THEN PUSH BACK TOWARD THE WESTERN LAKES BY THU INTO THE WEEKEND. MON NIGHT INTO TUE...DEEP MOIST CYCLONIC FLOW IN THE WAKE OF THE MID LEVEL LOW WILL BRING SCT/ISOLD -SHRA TO MOST OF THE CWA. HOWEVER...WITH 850 MB TEMPS INTO THE 3C-5C RANGE AND LAKE WATER TEMPS NEAR 16C...LAKE ENHANCED RAIN WILL BRING MORE SIGNFICANT RAIN...WITH LIKELY TO CATEGORICAL POPS...TO LOCATIONS FAVORED BY WNW LOW LEVEL FLOW SUCH AS NW UPPER MI AND AREAS EAST OF MARQUETTE. UPSLOPE FLOW WILL ALSO HELP TO BOOST PCPN AMOUNTS OVER THE HIGHER TERRAIN. HIGH TEMPS WILL REMAIN IN THE UPPER 50S OVER THE NW HALF TO THE LOW AND MID 60S OVER THE SOUTH. TUE NIGHT AND WED...AS THE MID LEVEL LOW SHIFTS TO THE EAST...MODELS SUGGEST THAT LOW LEVEL WINDS WILL GRADUALLY VEER TO THE NNW AS 850 TEMPS CLIMB TO NEAR 7C BY 12Z/WED. THIS SHOULD BRING GREATER -SHRA COVERAGE INTO N CNTRL UPPER MI EVEN AS THE AMOUNTS DIMINISH. EXPECT THE PCPN TO DIMINISH AND END WED AS THE DEEP MOISTURE SHIFTS TO THE EAST. MAX TEMPS ARE EXPECTED REBOUND BACK INTO THE MID TO UPPER 60S. WED NIGHT INTO THU...WITH FAVORABLE RADIATIONAL COOLING CONDITIONS AS THE SFC RIDGE BUILDS INTO THE AREA AND PWAT VALUES BLO 0.5 INCH...EXPECT INLAND MIN TEMPS INTO THE MID 40S INLAND. ABUNDANT SUNSHINE THU SHOULD PUSH TEMPS BACK TO SEASONAL AVERAGES IN THE LOWER TO MID 70S. FRI-SUN...UNCERTAINTY INCREASES DUE TO MODEL DIFFERENCES IN HANDLING THE POSITION OF THE SFC FRONT AND IMPACT OF A SHRTWV MOVING OUT OF THE PLAINS. EXPECT TEMPS NEAR OR ABOVE NORMAL WITH HIGHS INTO THE MID AND UPPER 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 100 PM EDT SUN AUG 23 2015 THE BAND OF SHOWERS/THUNDERSTORMS AHEAD OF A COLD FRONT HAS ALREADY EXITED E OF THE TAF SITES. DRIER AIR IMMEDIATELY BEHIND THE COLD FRONT HAS RESULTED IN A PERIOD OF VFR CONDITIONS AT KIWD AND KCMX IN THE WAKE OF SHOWERS AND WILL RESULT IN A PERIOD OF VFR CONDITIONS AT KSAW AS WELL THIS AFTERNOON. BUT AN AREA OF MOISTER LLVL AIR WRAPPING BACK INTO THE REGION FM NRN MN WL BRING A RETURN OF MVFR CIGS THIS AFTN AT IWD AND CMX WITH INCRSG UPSLOPE W WIND ARND DEEP LO PRES IN NW ONTARIO. GUSTY W WINDS NEAR 30 KTS AND MVFR CONDITIONS WL DOMINATE IWD/CMX TNGT. STRONG WINDS MAY ALSO ALLOW SOME SCT SHRA AND PREDOMINANT MVFR CONDITIONS TO CARRY E INTO KSAW BY THIS EVENING AS WELL DESPITE DOWNSLOPE WEST FLOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 401 PM EDT SUN AUG 23 2015 A FALL LIKE LOW PRESSURE SYSTEM CURRENTLY TO THE NORTH OF THE LAKE OF THE WOODS WILL BRING WINDY CONDITIONS TO LAKE SUPERIOR THROUGH THE FIRST HALF OF THE UPCOMING WORK WEEK AS IT SLOWLY MOVES EAST ACROSS NORTHERN ONTARIO. GUSTY SOUTHERLY WINDS WILL CONTINUE THIS MORNING AHEAD OF A COLD FRONT OVER WESTERN LAKE SUPERIOR...BUT AS IT MOVES EAST ACROSS THE REST OF THE LAKE TODAY IT WILL SHIFT WINDS TO THE WEST AND LEAD TO GALES TO 35 KNOTS FOR PORTIONS OF WESTERN LAKE SUPERIOR THIS AFTERNOON AND EXPANDING ACROSS THE REST OF THE WESTERN HALF OF THE LAKE TONIGHT AND CONTINUING INTO MONDAY. WITH THE LOW SLOWLY WEAKENING MONDAY NIGHT INTO TUESDAY AS IT NEARS JAMES BAY...THE WINDS WILL GRADUALLY DIMINISH AND TURN TO THE NORTHWEST. HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES REGION FOR WEDNESDAY AND THURSDAY..WHICH WILL LOWER WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 2 AM TO 8 PM EDT MONDAY FOR LSZ265. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 5 PM EDT /4 PM CDT/ MONDAY FOR LSZ240>244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...JLB AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EDT SUN AUG 23 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 401 PM EDT SUN AUG 23 2015 12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW POTENT SHRTWV/ CUTOFF H5 LO LIFTING NORTH OF THE MN ARROWHEAD THIS AFTERNOON INTO ONTARIO. THIS POTENT SYSTEM CAUSED 00Z-12Z H5 HGT FALLS OF 160M AT KINL AND 120-140M HGT FALLS OVER UPPER MI. STRONG UPPER DIFFLUENCE/DPVA AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF THIS FEATURE AND AHEAD OF THE ASSOCIATED COLD FRONTAL PASSAGE RESULTED IN A LINE OF HEAVY SHOWERS AND STRONG STORMS MOVING ACROSS UPPER MI THIS MORNING INTO THE AFTERNOON HOURS. THE MAIN LINE OF SHOWERS HAS EXITED E OF MOST OF THE CWA...BUT THERE WAS STILL SOME LINGERING SCATTERED SHOWERS AHEAD OF THE FRONTAL BOUNDARY WHICH WAS APPROXIMATELY ALONG A LINE FROM MUNISING TO GARDEN IN PAST HOUR. SOME SCATTERED SHOWERS WERE ALSO BEGINNING TO WORK INTO THE FAR WRN CWA THIS PAST HOUR WITH WRAPAROUND MOISTURE MOVING IN ON BACKSIDE OF ONTARIO LOW. TONIGHT AND MONDAY...SCATTERED SHOWERS OVER THE EASTERN THIRD OF THE CWA SHOULD END BETWEEN 22-00Z THIS EVENING AS FRONT EXITS THE AREA. ATTENTION WILL THEN TURN TO WRAPAROUND MOISTURE AND STRONG COLD ADVECTION ON THE BACKSIDE OF NEARLY VERICALLY STACKED LOW PRESSURE SYSTEM DRIFTING SLOWLY EAST FROM ONTARIO ACROSS THE UPPER GREAT LAKES REGION. THIS DEEPER MOISTURE AND COLD ADVECTION WILL LEAD TO LAKE ENHANCED RAIN SHOWERS FOR AREAS DOWNWIND OF LAKE SUPERIOR IN A WNW WIND FLOW. 8H TEMPS DROPPING TO 3C WEST AND 5-6C EAST LATE TONIGHT IN A WESTERLY FLOW WILL LEAD TO AN INCREASE IN COVERAGE OF LAKE EFFECT RAIN SHOWERS LATE TONIGHT OVER THE WRN U.P. AND EVEN CARRYING INTO THE HURON MOUNTAINS AS CONVECTIVE BOUNDARY LAYER WINDS INCREASE TOWARD 30KTS BEHIND THE SYSTEM. THE COLD ADVECTION WILL RESULT IN LAKE DELTA-T VALUES 10-13C SUFFICIENT FOR LAKE ENHANCED RAIN IN STRONGLY CYCLONIC WESTERLY FLOW. WILL CONTINUE LIKELY TO CATEGORICAL POPS OVER THESE AREAS TONIGHT INTO MONDAY. WINDS VEERING MORE NW DURING THE DAY ON MONDAY WILL BRING LAKE EFFECT RAIN SHOWERS INTO ERN COUNTIES OF UPPER MI SO HAVE CORRESPONDINGLY BUMPED UP POPS THERE TO HIGH LIKELY/CATEGORICAL ON MONDAY AS WELL. THE REST OF THE CWA WILL SEE ISOLD TO SCT LAKE EFFECT SHOWERS LATE TONIGHT INTO MONDAY. TEMPS WILL BE DROPPING QUICKLY TONIGHT WITH THE CAA IN THE WAKE OF THE SYSTEM. EXPECT LOWS RANGING FROM THE UPPER 40S INTERIOR WEST TO MID 50S NEAR THE GREAT LAKES SHORELINES. MONDAY WILL FEEL MORE LIKE OCTOBER AS TEMPS ONLY RISE A FEW DEGREES WITH MOST READINGS STAYING IN THE 50S. RECORD LOW MAXIMUM TEMPS ON MONDAY WILL BE IN JEOPARDY AT A NUMBER OF SITES. DEEP MIXING FROM COLD ADVECTION WILL ALLOW FOR BREEZY CONDITIONS ACROSS THE CWA THROUGH MUCH OF THE PERIOD. IT WILL BE WINDY OVER THE KEWEENAW PENINSULA (ESPECIALLY THE PORTAGE CANAL) WITH THE FAVORED WESTERLY WIND DIRECTION AND MORE UNSTABLE FLOW OFF LAKE SUPERIOR SO EXPECT THE POTENTIAL FOR WINDS GUSTING 35-40 MPH AT SOME OF THE MORE EXPOSED LOCATIONS OVER THE KEWEENAW. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 312 AM EDT SUN AUG 23 2015 THE NEARLY VERTICALLY STACKED SURFACE AND UPPER LOW AT 12Z MONDAY WILL BE SLOWLY MOVING EAST ACROSS NORTHERN ONTARIO AND WILL CONTINUE THAT PATH THROUGH TUESDAY NIGHT BEFORE FINALLY BECOMING CAUGHT UP IN THE NORTHERN STREAM FLOW AND QUICKLY LIFTING NORTHEAST THROUGH QUEBEC ON WEDNESDAY/THURSDAY. THIS WILL LEAD TO A VERY FALL LIKE START TO THE WORK WEEK WITH BREEZY WEST-NORTHWEST WINDS...PERIODS OF LAKE EFFECT/ENHANCED RAIN AND TEMPERATURES WELL BELOW NORMAL. WITH ABUNDANT MOISTURE WRAPPING AROUND THE UPPER/SURFACE LOW...EXPECT PLENTY OF LOW CLOUDS (AND SCATTERED TO NUMEROUS SHOWERS) ACROSS THE U.P. FOR MONDAY INTO AT LEAST WEDNESDAY MORNING. THE MAIN QUESTION WILL BE HOW COLD THE 850MB TEMPS WILL BE TO THE SOUTHWEST OF THE LOW IN ONTARIO. MODELS VARY IN THE EXACT VALUE...WITH THE NAM THE COLDEST AT 0-1C AND THE REST IN THE 2.5-4C RANGE FOR MONDAY AND THEN GRADUALLY WARMING THROUGH TUESDAY. THE EXACT VALUE DOESN/T MATTER TOO MUCH...AS THE TEMPERATURES ALOFT WILL BE COLD ENOUGH FOR LAKE ENHANCED/EFFECT RAIN WITH WESTERN LAKE SUPERIOR TEMPERATURES AROUND 15-17C. THEREFORE...WILL SHOW LIKELY TO DEFINITE VALUES FOR THE FAVORED WEST-NORTHWEST WIND AREAS ON MONDAY AND TRANSITION TO MORE NORTHWESTERLY FOR MONDAY NIGHT INTO TUESDAY. IN ADDITION...WILL HAVE THE HIGHEST POPS OVER THE FAVORED UPSLOPE LOCATIONS FOR THE MONDAY INTO TUESDAY PERIOD (AREAS FROM THE SPINE OF THE KEWEENAW THROUGH IRONWOOD). THAT UPSLOPE FORCING WILL BE DUE TO THE WEST-NORTHWEST WINDS ON MONDAY AND THEN TRANSITION TO MORE NORTHWESTERLY ON MONDAY NIGHT AS THE SURFACE-850MB LOW SHIFTS EAST AND CLOSER TO JAMES BAY AND THE SURFACE TROUGH MOVES EAST ACROSS THE UPPER GREAT LAKES. THAT NORTHWESTERLY LOW LEVEL FLOW WILL CONTINUE INTO WEDNESDAY...POTENTIALLY TURNING A LITTLE MORE NORTH-NORTHWEST. THE STRONGEST WINDS WILL OCCUR MONDAY INTO MONDAY NIGHT (GUSTS OF 20- 30KTS OVER THE WESTERN U.P.) WITH THE TIGHTEST PRESSURE GRADIENT AS THE SURFACE LOW IS JUST TO THE NORTH OF LAKE SUPERIOR. THEN THE WINDS WILL GRADUALLY DIMINISH TUESDAY INTO WEDNESDAY AS THE LOW WEAKENS/BROADENS AS IT MOVES INTO NORTHEAST ONTARIO. THE THIRD ITEM OF NOTE TO START THE WEEK WILL BE THE VERY FALL LIKE HIGHS ACROSS THE AREA ON MONDAY. WITH PLENTY OF CLOUDS AND SHOWERS...HAVE OPTED TO FOLLOW THE RAW MODELS FOR HIGHS ON MONDAY...WHICH GIVES LOW-MID 50S OVER THE WEST AND MID-UPPER 50S OVER THE EAST. THIS IS ABOUT 20 DEGREES BELOW NORMAL AND IN SOME AREAS THEY WILL BE NEARING RECORD COLD HIGH TEMPERATURES. THE RECORD FOR OUR OFFICE IS 56 DEGREES (1978/1971) AND WE WILL BE NEAR THAT BOTH AT MIDNIGHT TONIGHT AND AGAIN WITH THE HIGH ON MONDAY AFTERNOON. LOOKING AT THE TIME SHIFTED COOP DATA (NEED TO USE 8/25 VALUES)...MANY SITES HAVE RECORD VALUES IN THE 50S AND SOME OF THE MORE NOTABLE ONES ARE...IRONWOOD 55 IN 1915...HOUGHTON 53 IN 1987 (MIDNIGHT-MIDNIGHT)...IRON MOUNTAIN 59 IN 1940...MUNISING 57 IN 1940...AND 55 IN NEWBERRY IN 1917. THUS...WITH THE GOING FORECAST HIGH TEMPERATURES...THERE WILL BE SEVERAL SPOTS THAT WILL BE NEAR RECORD LOW MAXIMUM VALUES. TEMPERATURES WILL WARM A FEW DEGREES FOR TUESDAY...BUT HIGHS WILL STILL BE IN THE UPPER 50S AND LOWER 60S. DRY AIR FROM THE HIGH BUILDING INTO THE PLAINS ON WEDNESDAY WILL FINALLY BRING AN END TO THE PROLONGED PERIOD OF CLOUDS AND SHOWERS FROM WEST TO EAST ON WEDNESDAY (ALTHOUGH THE CLOUDS MAY LINGER OVER THE FAR EAST INTO THE EVENING HOURS). THAT HIGH PRESSURE RIDGE WILL MOVE OVER THE AREA WEDNESDAY NIGHT AND REMAIN INTO THURSDAY. CLEARING SKIES AND LIGHT WINDS ON WEDNESDAY NIGHT WILL LEAD TO A GOOD RADIATIONAL COOLING NIGHT ACROSS THE AREA AND HAVE LOWER LOWS SOME FROM THE PREVIOUS FORECAST (CLOSER TO THE MEX AND GEM VALUES WHICH TEND TO PERFORM BETTER IN THOSE SITUATIONS). ABUNDANT SUNSHINE ON THURSDAY WILL LEAD TO HIGHS RETURNING TO MORE NORMAL VALUES FOR LATE AUGUST. FINALLY...A COLD FRONT WILL DROP SOUTHEAST ACROSS THE UPPER GREAT LAKES LATE THURSDAY NIGHT INTO FRIDAY...BRINGING A CHANCE FOR SHOWERS/THUNDERSTORMS TO THE U.P.. THINK THE COVERAGE/AMOUNTS WILL LIMITED DUE TO THE LACK OF RETURN FLOW AND EXISTING DRY AIR. THUS...WON/T GO MORE THAN LOW CHANCE POPS FOR NOW AS THE FRONT MOVES THROUGH. A WEAK RIDGE LOOKS TO MOVE OVER THE AREA FOR SATURDAY BEHIND THE FRONT AND SHOULD LEAD TO A DRY DAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 100 PM EDT SUN AUG 23 2015 THE BAND OF SHOWERS/THUNDERSTORMS AHEAD OF A COLD FRONT HAS ALREADY EXITED E OF THE TAF SITES. DRIER AIR IMMEDIATELY BEHIND THE COLD FRONT HAS RESULTED IN A PERIOD OF VFR CONDITIONS AT KIWD AND KCMX IN THE WAKE OF SHOWERS AND WILL RESULT IN A PERIOD OF VFR CONDITIONS AT KSAW AS WELL THIS AFTERNOON. BUT AN AREA OF MOISTER LLVL AIR WRAPPING BACK INTO THE REGION FM NRN MN WL BRING A RETURN OF MVFR CIGS THIS AFTN AT IWD AND CMX WITH INCRSG UPSLOPE W WIND ARND DEEP LO PRES IN NW ONTARIO. GUSTY W WINDS NEAR 30 KTS AND MVFR CONDITIONS WL DOMINATE IWD/CMX TNGT. STRONG WINDS MAY ALSO ALLOW SOME SCT SHRA AND PREDOMINANT MVFR CONDITIONS TO CARRY E INTO KSAW BY THIS EVENING AS WELL DESPITE DOWNSLOPE WEST FLOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 401 PM EDT SUN AUG 23 2015 A FALL LIKE LOW PRESSURE SYSTEM CURRENTLY TO THE NORTH OF THE LAKE OF THE WOODS WILL BRING WINDY CONDITIONS TO LAKE SUPERIOR THROUGH THE FIRST HALF OF THE UPCOMING WORK WEEK AS IT SLOWLY MOVES EAST ACROSS NORTHERN ONTARIO. GUSTY SOUTHERLY WINDS WILL CONTINUE THIS MORNING AHEAD OF A COLD FRONT OVER WESTERN LAKE SUPERIOR...BUT AS IT MOVES EAST ACROSS THE REST OF THE LAKE TODAY IT WILL SHIFT WINDS TO THE WEST AND LEAD TO GALES TO 35 KNOTS FOR PORTIONS OF WESTERN LAKE SUPERIOR THIS AFTERNOON AND EXPANDING ACROSS THE REST OF THE WESTERN HALF OF THE LAKE TONIGHT AND CONTINUING INTO MONDAY. WITH THE LOW SLOWLY WEAKENING MONDAY NIGHT INTO TUESDAY AS IT NEARS JAMES BAY...THE WINDS WILL GRADUALLY DIMINISH AND TURN TO THE NORTHWEST. HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES REGION FOR WEDNESDAY AND THURSDAY..WHICH WILL LOWER WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 2 AM TO 8 PM EDT MONDAY FOR LSZ265. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 5 PM EDT /4 PM CDT/ MONDAY FOR LSZ240>244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
142 PM EDT SUN AUG 23 2015 .UPDATE... ISSUED AT 134 PM EDT SUN AUG 23 2015 LINE OF THUNDERSTORMS IS MOVING ACROSS N LOWER ATTM, WITH THE A MORE STRATIFORM PORTION IN E UPPER. NO CHANGES EXPECTED DURING THE NEXT HOUR OR TWO IN THE FORECAST AS IT LOOKS LIKE THE STORM TIMING IS ABOUT WHAT WE HAVE IN THE FORECAST. UPDATE ISSUED AT 939 AM EDT SUN AUG 23 2015 COLD FRONT AND THUNDERSTORMS ASSOCIATED WITH THE FRONT IS MAKING PROGRESS TO AND ACROSS LAKE MICHIGAN AT THE MOMENT. UPDATED THE POPS TO SLOW THE TIMING DOWN JUST A BIT BASED ON THE RADAR TRENDS AND THE HRRR WHICH SEEMED TO LINE UP PRETTY WELL AT 11Z WITH THE CURRENT TRENDS. WILL CONTINUE TO UPDATE AGGRESSIVELY WITH THE TIMING OVER THE NEXT FEW HOURS AS THE FRONT MOVES ACROSS THE REGION. LATER HRRR RUNS SEEM TO GO ALONG AS WELL WITH THE CURRENT RADAR TRENDS FROM KGRB AND KAPX. OTHERWISE, TEMPERATURES SEEM TO BE FALLING ALONG WITH THE CURRENT THINKING. && .NEAR TERM...(TODAY THROUGH TONIGHT) ISSUED AT 326 AM EDT SUN AUG 23 2015 HIGH IMPACT WEATHER: BAND OF SHOWERS AND STORMS. A FEW SEVERE POSSIBLE. SYNOPTIC PATTERN AND OBSERVATIONS: EARLY MORNING ANALYSIS..A VERY IMPRESSIVE SHORTWAVE HAS CLOSED OFF WHILE WORKING INTO MN. THE ASSOCIATED SFC LOW PRESSURE WAS FILLING IN WESTERN ONTARIO...WITH A COLD FRONT DRAPED SOUTHWARD THROUGH NW WISCONSIN AND IA. A BAND OF SHOWERS AND STORMS CONTINUES TO SLOWLY PROGRESS EAST...WITHIN AXIS OF HIGH THETA-E AND SUPPORTED BY A SWATH OF UPPER LEVEL DIVERGENCE IN A DOUBLE JET STRUCTURE. LAPSE RATES NOT IMPRESSIVE...BUT DYNAMICAL FORCING IS ENOUGH TO CONTINUE STORMS INTO THE NIGHT. ACROSS NRN MICHIGAN...AN EARLIER WING OF HIGHER THETA-E AT 850MB HAS SLOWLY LIFTED NNE...WHILE A CORRIDOR OF DRIER/LOWER THETA-E WAS WORKING INTO THE REGION. SKIES WERE CLEAR WITH ONLY SOME THIN CIRRUS ENCROACHING. TEMPERATURES WERE IN THE 60S. SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER: QUITE A CHANGE IN THE WEATHER IS IN STORE. FIRST OFF...THE UPSTREAM COLD FRONT WILL CROSS NRN MICHIGAN MID-LATE MORNING THROUGH EARLY THIS EVENING. ONE VORTICITY MAX WILL LIFT NE INTO THE WESTERN CWA THIS MORNING...AND ANOTHER THIS AFTERNOON...ROUNDING THE BASE OF THE CLOSED/NEGATIVELY TILTED UPPER TROUGH. WE DO GET INTO SOME UPPER DIVERGENCE WITH A LEFT FRONT EXIT REGION...OF A JET ON THE SRN PERIPHERY OF THE UPPER TROUGH...BUT FORCING MAINLY APPLIED BY DPVA AND LOW LEVEL CONVERGENCE. LAPSE RATES ARE LESS THAN DESIRABLE AT 5.5 TO 6.0 C/KM. SFC BASED DEW POINTS WILL ONLY BE IN THE MIDDLE 50S WITHIN THE DRIER AIR/SWATH OF LOWER THETA-E AIR...BUT DEW POINTS WILL POOL IN THE LOWER HALF OF THE 60S ALONG THE FRONT WHICH ARRIVES MID-LATE MORNING ACROSS THE WESTERN CWA...AND THIS AFTERNOON ACROSS NE LOWER. HEATING WILL BE DIFFICULT TO COME BY IN THE WESTERN CWA...WITH CLOUDS INCREASING TOO EARLY FOR MUCH HEATING WHERE HIGHS WILL BE IN THE LOWER 70S. ACROSS NE LOWER...SUNSHINE WILL BE ABLE TO WARM TEMPERATURES INTO THE UPPER 70S AROUND 80F. BY THE TIME THE FRONT ARRIVES WITH THE BETTER LOW LEVEL MOISTURE...CAPE WILL BE IN THE 800-1200 J/KM RANGE. NOT OVERLAY FANTASTIC...AND 0-6 KM BULK SHEAR WITH THE STORMS WILL BE MARGINAL FOR ANY ORGANIZED CONVECTION...25-30KTS. ALL-IN-ALL...A FEW STORMS MAY BE ABLE TO BECOME SEVERE...MAINLY M-32 SOUTH AND MOSTLY EAST OF I-75. DAMAGING WINDS THE MAIN THREAT...BUT STRONGER CELLS WILL BE ABLE TO PRODUCE AT LEAST SOME HAIL. BEHIND THE FRONT...SOME SCATTERED SHOWERS ARE LIKELY...BUT DEEPER MOISTURE STRIPS OUT WITH A POSSIBLE A PERIOD OF CLEARING. COOLER LOW LEVEL AIR AND DEEPER LOWER LEVEL MOISTURE ADVECTION THROUGH THE NIGHT. THE DEEPEST MOISTURE WILL REMAIN TO OUR NW...BUT WE HAVE ENOUGH OVERNIGHT TO COMBINE WITH H8 TEMPS CRASHING INTO THE SINGLE DIGITS FOR THE DEVELOPMENT OF LAKE EFFECT RAIN SHOWERS. NOT ONLY THAT...BUT THE INSTABILITY DEEPENS OVER THE LAKES (500-700 J/KG) AND THERE WILL BE AT LEAST A CHANCE FOR A RUMBLE OF THUNDER OR TWO. THIS WILL PRIMARILY BE WSW FLOW REGIMES...ACROSS FAR NW LOWER...THROUGH THE STRAITS...AND OVER TO DRUMMOND ISLAND. HIGHS WILL RANGE FROM THE LOWER 70S WEST TO THE UPPER 70S EAST. LOWS TONIGHT GENERALLY IN THE MIDDLE 50S AND GUSTY ALONG THE LAKE MICHIGAN COAST. && .SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT) ISSUED AT 326 AM EDT SUN AUG 23 2015 HIGH IMPACT WEATHER POTENTIAL: BESIDES JUST BEING DOWNRIGHT CHILLY MONDAY AND TUESDAY...STILL MONITORING WATERSPOUT POTENTIAL FOR BOTH THESE DAYS (WHICH WILL BE COVERED IN THE MARINE SECTION TO FOLLOW). PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: PATTERN GETTING SET TO BECOME QUITE THE AMPLIFIED ONE...WITH MAIN PLAYER DRIVING SUCH AMPLIFICATION BEING STRONG UPPER JET CORE/ATTENDANT MID LEVEL WAVE DIGGING INTO THE UPPER MISSISSIPPI VALLEY EARLY THIS MORNING. THIS SYSTEM WILL HELP CARVE OUT AN ANOMALOUSLY DEEP (FOR THE TIME OF YEAR AT LEAST) AND CHILLY MID LEVEL LOW...WHICH WILL CENTER ITSELF RIGHT OVER THE NORTHERN LAKES AND SOUTHERN CANADA THROUGH AT LEAST THE FIRST HALF OF THIS UPCOMING WORK WEEK. PRIMARY FORECAST CONCERNS/CHALLENGES: ADDRESSING MULTIPLE PERIODS OF LAKE ENHANCED SHOWERS. TEMPERATURE TRENDS THROUGH THE FORECAST. ADDRESSING WATERSPOUT POTENTIAL. DETAILS: UPPER LEVEL LOW...CHECK. COOL TEMPERATURES...CHECK. GUSTY WINDS...CHECK. LAKE ENHANCED RAIN SHOWERS...CHECK. YUP...IT ALL ADDS UP...OCTOBER WEATHER HERE IN THE END OF AUGUST. THAT`S MONDAY`S AND TUESDAY`S WEATHER FOLKS...AND EVEN A COOL WEATHER FAN LIKE MYSELF HAS TO SAY ITS NOT LOOKING PLEASANT. BLAME IT ALL ON THAT CURRENT MINNESOTA WAVE...WITH IT AND A NICE UPPER LEVEL COUPLED JET HELPING CARVE OUT THAT DEEP LOW MENTIONED EARLIER. DEEP CYCLONIC FLOW AROUND IT...COUPLED WITH EXCELLENT LOW LEVEL MOISTURE AND PERIODS OF UPWARD QG SUPPORT WILL BE MORE THAN ENOUGH TO KICK OFF SOME SHOWERS. ADD IN INCREASING LAKE MOISTURE CONTRIBUTION AS H8 TEMPS FALL INTO THE MID SINGLE DIGITS AND DIURNALLY DRIVEN ENHANCEMENT AWAY FROM THE LAKES...AND NUMEROUS TO WIDESPREAD SHOWERS APPEARS A PRETTY GOOD BET. DAYTIME FORECASTER TRENDED TOWARD THIS MORE WET LOOKING SCENARIO...AND SIMPLY SEE NO REASON TO DEVIATE FROM IT. IT IS NOT COMPLETELY OUT OF THE QUESTION FOR SOME LAKE PRODUCED THUNDERSTORMS ...PARTICULARLY MONDAY AND MONDAY EVENING WHEN NAM-WRF BUFKIT SOUNDINGS SHOW IN EXCESS OF 500 J/KG OF LAKE INDUCED CAPE AND EQUILIBRIUM LEVELS OVER 20 KFT. IF STORMS DO FORM...SOME SMALL HAIL IS INDEED POSSIBLE WITH WET BULB ZERO HEIGHTS AT ONLY ABOUT 6KFT. AS MENTIONED...IT`S GONNA BE DOWNRIGHT CHILLY FOR AUGUST...WITH CLOUDS...SHOWERS...AND AN UNSEASONABLY COOL AIRMASS KEEPING HIGHS MOSTLY IN THE 60S. AS HAS BEEN MENTIONED THE LAST FEW DAYS...COULD EASILY SEE PARTS OF EASTERN UPPER AND THE HIGHLAND OF NORTHERN LOWER FAILING TO BREAK 60 DEGREES...ESPECIALLY ON TUESDAY. IT REALLY WON`T MATTER...WITH PRETTY GUSTY WINDS MAKING IT FEEL IN THE 50S ACROSS MUCH OF THE AREA. && .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 326 AM EDT SUN AUG 23 2015 WHILE SLOWLY WANING...TROUGHING AND COOL WEATHER CONTINUE TO DOMINATE HEADING RIGHT INTO WEDNESDAY. LAKE PROCESSES WILL CONTINUE...ALTHOUGH SLOWLY WEAKENING WITH TIME AS COLD CORE ANOMALIES RELAX AND FORCING DEPARTS. ANY BREAK LATER WEDNESDAY NIGHT AND THURSDAY WILL BE SHORT- LIVED AS FAST MOVING WAVE DIVES THROUGH NORTHWEST FLOW ALOFT...WITH IT AND ITS ATTENDANT COLD FRONT RETURNING A SHOWER THREAT FRIDAY INTO THE START OF SATURDAY. WHILE NOT NEAR AS COOL AS EARLIER IN THE WEEK... TEMPERATURES WILL CONTINUE TO RUN AT LEAST A FEW DEGREES BELOW NORMAL. MARINE...STILL CONCERNED ABOUT WATERSPOUT POTENTIAL...ESPECIALLY LATER MONDAY INTO MONDAY NIGHT WHEN LAKE-INDUCED CAPE IS MAXIMIZED...PERHAPS EXCEEDING 500 J/KG WITH EQUILIBRIUM LEVELS UP NEAR 20KFT. WHILE THIS MAY BE A TOUCH AGGRESSIVE...WITH DEEP TROUGHING AND SEVERAL WAVES/SURFACE TROUGHS TO ENHANCE CONVERGENCE...GOTTA BELIEVE THERE IS SOME POTENTIAL. WILL NOT INTRODUCE THIS WORDING TO THE OFFICIAL FORECAST JUST YET...USING THE LATEST HAZARDOUS WEATHER OUTLOOK TO EXPRESS THIS CONCERN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 134 PM EDT SUN AUG 23 2015 MVFR TO POSSIBLE IFR NEAR THE THUNDERSTORMS. THE BACK EDGE OF THE STORMS IS NEARING TVC AT THE MOMENT AND IS THROUGH MBL. WILL EXPECT THAT THE STORMS WILL BE OF THE LAKE HURON SHORE BY 00Z. AFTER THAT, SIGNIFICANT COOLING WILL TAKE PLACE, ESPECIALLY AT 850 MB. THE COOLING WILL LEAD TO RAIN SHOWERS LATER TONIGHT. AS THE COLDER AIR SPREADS MORE INTO NORTHERN MICHIGAN, THE RAIN SHOWERS WILL CONTINUE TO SPREAD OUT OVER NW LOWER MICHIGAN. WITH THE RAIN SHOWERS IT LOOKS LIKE MVFR CIGS, AND OCCASIONAL MVFR VSBYS. && .MARINE... ISSUED AT 326 AM EDT SUN AUG 23 2015 SOUTHERLY WINDS ARE INCREASING ACROSS THE LAKES AHEAD OF AN APPROACHING COLD FRONT...WHICH WILL CROSS THE REGION TODAY AND THIS EVENING. ADVISORY LEVEL GUSTS ARE EXPECTED AT ALL NEARSHORES...BUT AS WE REMAIN IN A TIGHT GRADIENT BEHIND THE FRONT...IN STRONG COLD ADVECTION...ADVISORY LEVEL GUSTS ARE A BETTER BET. THE FRONT WILL BRING A BAND OF SHOWERS AND STORMS...SOME OF WHICH MAY BE STRONG WITH SOME GUSTY WINDS AND HAIL. STRONG COLD ADVECTION CONTINUES INTO MONDAY WITH LAKE EFFECT RAIN SHOWERS (AND A FEW RUMBLES OF THUNDER AGAIN POSSIBLE). OTHER ISSUES COME ABOUT...LIKE THE NEED TO MONITOR FOR POSSIBLE WATERSPOUTS...ESPECIALLY LATER MONDAY THROUGH TUESDAY. SIMPLE PATTERN RECOGNITION OF ANOMALOUSLY DEEP MID AND UPPER LEVEL LOW CENTERED NEARBY THIS TIME OF YEAR SURE SUPPORTS SUCH. EARLY INDICATIONS OF SEVERAL VORT LOBES/ATTENDANT SURFACE TROUGHS ROTATING AROUND PARENT CIRCULATION...FURTHER ENHANCING LOW LEVEL CONVERGENCE. LAKE INDUCED EQUILIBRIUM LEVELS SOARING TO OVER 20 KFT DURING THIS PERIOD...WHICH FAVORS UPPER LEVEL LOW ASSOCIATED WATERSPOUTS PER THE SZILAGYI WATERSPOUT NOMOGRAM. WILL STILL NOT SPECIFICALLY INTRODUCE THIS POTENTIAL IN THE FORECAST...BUT VERY WELL MAY NEED TO IN LATER FORECASTS. && .APX WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR MIZ008-015-016- 019>021-025-031. LH...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR LMZ323-341-342- 344>346. LS...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LSZ321-322. && $$ UPDATE...JSL NEAR TERM...SMD SHORT TERM...MSB LONG TERM...MSB AVIATION...JSL MARINE...SMD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1001 AM EDT SUN AUG 23 2015 .UPDATE... ISSUED AT 939 AM EDT SUN AUG 23 2015 COLD FRONT AND THUNDERSTORMS ASSOCIATED WITH THE FRONT IS MAKING PROGRESS TO AND ACROSS LAKE MICHIGAN AT THE MOMENT. UPDATED THE POPS TO SLOW THE TIMING DOWN JUST A BIT BASED ON THE RADAR TRENDS AND THE HRRR WHICH SEEMED TO LINE UP PRETTY WELL AT 11Z WITH THE CURRENT TRENDS. WILL CONTINUE TO UPDATE AGGRESSIVELY WITH THE TIMING OVER THE NEXT FEW HOURS AS THE FRONT MOVES ACROSS THE REGION. LATER HRRR RUNS SEEM TO GO ALONG AS WELL WITH THE CURRENT RADAR TRENDS FROM KGRB AND KAPX. OTHERWISE, TEMPERATURES SEEM TO BE FALLING ALONG WITH THE CURRENT THINKING. && .NEAR TERM...(TODAY THROUGH TONIGHT) ISSUED AT 326 AM EDT SUN AUG 23 2015 HIGH IMPACT WEATHER: BAND OF SHOWERS AND STORMS. A FEW SEVERE POSSIBLE. SYNOPTIC PATTERN AND OBSERVATIONS: EARLY MORNING ANALYSIS..A VERY IMPRESSIVE SHORTWAVE HAS CLOSED OFF WHILE WORKING INTO MN. THE ASSOCIATED SFC LOW PRESSURE WAS FILLING IN WESTERN ONTARIO...WITH A COLD FRONT DRAPED SOUTHWARD THROUGH NW WISCONSIN AND IA. A BAND OF SHOWERS AND STORMS CONTINUES TO SLOWLY PROGRESS EAST...WITHIN AXIS OF HIGH THETA-E AND SUPPORTED BY A SWATH OF UPPER LEVEL DIVERGENCE IN A DOUBLE JET STRUCTURE. LAPSE RATES NOT IMPRESSIVE...BUT DYNAMICAL FORCING IS ENOUGH TO CONTINUE STORMS INTO THE NIGHT. ACROSS NRN MICHIGAN...AN EARLIER WING OF HIGHER THETA-E AT 850MB HAS SLOWLY LIFTED NNE...WHILE A CORRIDOR OF DRIER/LOWER THETA-E WAS WORKING INTO THE REGION. SKIES WERE CLEAR WITH ONLY SOME THIN CIRRUS ENCROACHING. TEMPERATURES WERE IN THE 60S. SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER: QUITE A CHANGE IN THE WEATHER IS IN STORE. FIRST OFF...THE UPSTREAM COLD FRONT WILL CROSS NRN MICHIGAN MID-LATE MORNING THROUGH EARLY THIS EVENING. ONE VORTICITY MAX WILL LIFT NE INTO THE WESTERN CWA THIS MORNING...AND ANOTHER THIS AFTERNOON...ROUNDING THE BASE OF THE CLOSED/NEGATIVELY TILTED UPPER TROUGH. WE DO GET INTO SOME UPPER DIVERGENCE WITH A LEFT FRONT EXIT REGION...OF A JET ON THE SRN PERIPHERY OF THE UPPER TROUGH...BUT FORCING MAINLY APPLIED BY DPVA AND LOW LEVEL CONVERGENCE. LAPSE RATES ARE LESS THAN DESIRABLE AT 5.5 TO 6.0 C/KM. SFC BASED DEW POINTS WILL ONLY BE IN THE MIDDLE 50S WITHIN THE DRIER AIR/SWATH OF LOWER THETA-E AIR...BUT DEW POINTS WILL POOL IN THE LOWER HALF OF THE 60S ALONG THE FRONT WHICH ARRIVES MID-LATE MORNING ACROSS THE WESTERN CWA...AND THIS AFTERNOON ACROSS NE LOWER. HEATING WILL BE DIFFICULT TO COME BY IN THE WESTERN CWA...WITH CLOUDS INCREASING TOO EARLY FOR MUCH HEATING WHERE HIGHS WILL BE IN THE LOWER 70S. ACROSS NE LOWER...SUNSHINE WILL BE ABLE TO WARM TEMPERATURES INTO THE UPPER 70S AROUND 80F. BY THE TIME THE FRONT ARRIVES WITH THE BETTER LOW LEVEL MOISTURE...CAPE WILL BE IN THE 800-1200 J/KM RANGE. NOT OVERLAY FANTASTIC...AND 0-6 KM BULK SHEAR WITH THE STORMS WILL BE MARGINAL FOR ANY ORGANIZED CONVECTION...25-30KTS. ALL-IN-ALL...A FEW STORMS MAY BE ABLE TO BECOME SEVERE...MAINLY M-32 SOUTH AND MOSTLY EAST OF I-75. DAMAGING WINDS THE MAIN THREAT...BUT STRONGER CELLS WILL BE ABLE TO PRODUCE AT LEAST SOME HAIL. BEHIND THE FRONT...SOME SCATTERED SHOWERS ARE LIKELY...BUT DEEPER MOISTURE STRIPS OUT WITH A POSSIBLE A PERIOD OF CLEARING. COOLER LOW LEVEL AIR AND DEEPER LOWER LEVEL MOISTURE ADVECTION THROUGH THE NIGHT. THE DEEPEST MOISTURE WILL REMAIN TO OUR NW...BUT WE HAVE ENOUGH OVERNIGHT TO COMBINE WITH H8 TEMPS CRASHING INTO THE SINGLE DIGITS FOR THE DEVELOPMENT OF LAKE EFFECT RAIN SHOWERS. NOT ONLY THAT...BUT THE INSTABILITY DEEPENS OVER THE LAKES (500-700 J/KG) AND THERE WILL BE AT LEAST A CHANCE FOR A RUMBLE OF THUNDER OR TWO. THIS WILL PRIMARILY BE WSW FLOW REGIMES...ACROSS FAR NW LOWER...THROUGH THE STRAITS...AND OVER TO DRUMMOND ISLAND. HIGHS WILL RANGE FROM THE LOWER 70S WEST TO THE UPPER 70S EAST. LOWS TONIGHT GENERALLY IN THE MIDDLE 50S AND GUSTY ALONG THE LAKE MICHIGAN COAST. && .SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT) ISSUED AT 326 AM EDT SUN AUG 23 2015 HIGH IMPACT WEATHER POTENTIAL: BESIDES JUST BEING DOWNRIGHT CHILLY MONDAY AND TUESDAY...STILL MONITORING WATERSPOUT POTENTIAL FOR BOTH THESE DAYS (WHICH WILL BE COVERED IN THE MARINE SECTION TO FOLLOW). PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: PATTERN GETTING SET TO BECOME QUITE THE AMPLIFIED ONE...WITH MAIN PLAYER DRIVING SUCH AMPLIFICATION BEING STRONG UPPER JET CORE/ATTENDANT MID LEVEL WAVE DIGGING INTO THE UPPER MISSISSIPPI VALLEY EARLY THIS MORNING. THIS SYSTEM WILL HELP CARVE OUT AN ANOMALOUSLY DEEP (FOR THE TIME OF YEAR AT LEAST) AND CHILLY MID LEVEL LOW...WHICH WILL CENTER ITSELF RIGHT OVER THE NORTHERN LAKES AND SOUTHERN CANADA THROUGH AT LEAST THE FIRST HALF OF THIS UPCOMING WORK WEEK. PRIMARY FORECAST CONCERNS/CHALLENGES: ADDRESSING MULTIPLE PERIODS OF LAKE ENHANCED SHOWERS. TEMPERATURE TRENDS THROUGH THE FORECAST. ADDRESSING WATERSPOUT POTENTIAL. DETAILS: UPPER LEVEL LOW...CHECK. COOL TEMPERATURES...CHECK. GUSTY WINDS...CHECK. LAKE ENHANCED RAIN SHOWERS...CHECK. YUP...IT ALL ADDS UP...OCTOBER WEATHER HERE IN THE END OF AUGUST. THAT`S MONDAY`S AND TUESDAY`S WEATHER FOLKS...AND EVEN A COOL WEATHER FAN LIKE MYSELF HAS TO SAY ITS NOT LOOKING PLEASANT. BLAME IT ALL ON THAT CURRENT MINNESOTA WAVE...WITH IT AND A NICE UPPER LEVEL COUPLED JET HELPING CARVE OUT THAT DEEP LOW MENTIONED EARLIER. DEEP CYCLONIC FLOW AROUND IT...COUPLED WITH EXCELLENT LOW LEVEL MOISTURE AND PERIODS OF UPWARD QG SUPPORT WILL BE MORE THAN ENOUGH TO KICK OFF SOME SHOWERS. ADD IN INCREASING LAKE MOISTURE CONTRIBUTION AS H8 TEMPS FALL INTO THE MID SINGLE DIGITS AND DIURNALLY DRIVEN ENHANCEMENT AWAY FROM THE LAKES...AND NUMEROUS TO WIDESPREAD SHOWERS APPEARS A PRETTY GOOD BET. DAYTIME FORECASTER TRENDED TOWARD THIS MORE WET LOOKING SCENARIO...AND SIMPLY SEE NO REASON TO DEVIATE FROM IT. IT IS NOT COMPLETELY OUT OF THE QUESTION FOR SOME LAKE PRODUCED THUNDERSTORMS ...PARTICULARLY MONDAY AND MONDAY EVENING WHEN NAM-WRF BUFKIT SOUNDINGS SHOW IN EXCESS OF 500 J/KG OF LAKE INDUCED CAPE AND EQUILIBRIUM LEVELS OVER 20 KFT. IF STORMS DO FORM...SOME SMALL HAIL IS INDEED POSSIBLE WITH WET BULB ZERO HEIGHTS AT ONLY ABOUT 6KFT. AS MENTIONED...IT`S GONNA BE DOWNRIGHT CHILLY FOR AUGUST...WITH CLOUDS...SHOWERS...AND AN UNSEASONABLY COOL AIRMASS KEEPING HIGHS MOSTLY IN THE 60S. AS HAS BEEN MENTIONED THE LAST FEW DAYS...COULD EASILY SEE PARTS OF EASTERN UPPER AND THE HIGHLAND OF NORTHERN LOWER FAILING TO BREAK 60 DEGREES...ESPECIALLY ON TUESDAY. IT REALLY WON`T MATTER...WITH PRETTY GUSTY WINDS MAKING IT FEEL IN THE 50S ACROSS MUCH OF THE AREA. && .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 326 AM EDT SUN AUG 23 2015 WHILE SLOWLY WANING...TROUGHING AND COOL WEATHER CONTINUE TO DOMINATE HEADING RIGHT INTO WEDNESDAY. LAKE PROCESSES WILL CONTINUE...ALTHOUGH SLOWLY WEAKENING WITH TIME AS COLD CORE ANOMALIES RELAX AND FORCING DEPARTS. ANY BREAK LATER WEDNESDAY NIGHT AND THURSDAY WILL BE SHORT- LIVED AS FAST MOVING WAVE DIVES THROUGH NORTHWEST FLOW ALOFT...WITH IT AND ITS ATTENDANT COLD FRONT RETURNING A SHOWER THREAT FRIDAY INTO THE START OF SATURDAY. WHILE NOT NEAR AS COOL AS EARLIER IN THE WEEK... TEMPERATURES WILL CONTINUE TO RUN AT LEAST A FEW DEGREES BELOW NORMAL. MARINE...STILL CONCERNED ABOUT WATERSPOUT POTENTIAL...ESPECIALLY LATER MONDAY INTO MONDAY NIGHT WHEN LAKE-INDUCED CAPE IS MAXIMIZED...PERHAPS EXCEEDING 500 J/KG WITH EQUILIBRIUM LEVELS UP NEAR 20KFT. WHILE THIS MAY BE A TOUCH AGGRESSIVE...WITH DEEP TROUGHING AND SEVERAL WAVES/SURFACE TROUGHS TO ENHANCE CONVERGENCE...GOTTA BELIEVE THERE IS SOME POTENTIAL. WILL NOT INTRODUCE THIS WORDING TO THE OFFICIAL FORECAST JUST YET...USING THE LATEST HAZARDOUS WEATHER OUTLOOK TO EXPRESS THIS CONCERN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 641 AM EDT SUN AUG 23 2015 ...BAND OF SHOWERS WITH A FEW STORMS AND PERIODS OF MVFR ON THE WAY... A WEDGE OF DRY AIR OVER THE REGION WILL ALLOW FOR A SUNNY START TO THE DAY. A COLD FRONT THEN PUSHES THROUGH NRN MICHIGAN THROUGH THE DAY BRINGING A BAND OF SHOWERS AND A HANDFUL OF STORMS...A FEW OF WHICH HAVE A SLIGHT CHANCE OF BECOMING SEVERE ACROSS APN. THE PRIMARY THREAT IS DAMAGING WINDS...SOME STRONGER CELLS COULD PRODUCE SOME HAIL. THIS BAND ARRIVES IN NW LOWER LATE THIS MORNING...AND ACROSS APN LATE AFTERNOON/EARLY EVENING. PERIODS OF MVFR CIGS AND POSSIBLY VSBY WILL ACCOMPANY THE BAND OF SHOWERS...AS WILL ALSO BE POSSIBLE IN THE COOL AIR BEHIND THE FRONT. CONTINUED COOLING TONIGHT WILL BRING THE DEVELOPMENT OF LAKE EFFECT RAIN SHOWERS TO PLN. S/SW WINDS WILL BE GUSTY INITIALLY AHEAD OF THE FRONT...LONGEST PERIOD OF GUSTINESS ACROSS APN. GUSTS MAY DISAPPEAR FOR AWHILE WITHIN THE BAND OF RAIN...BUT WILL PICK UP AGAIN BEHIND THE FRONT OUT OF THE W/NW. THIS GUSTY CONDITION WILL CONTINUE ACROSS NW LOWER THROUGH TONIGHT. && .MARINE... ISSUED AT 326 AM EDT SUN AUG 23 2015 SOUTHERLY WINDS ARE INCREASING ACROSS THE LAKES AHEAD OF AN APPROACHING COLD FRONT...WHICH WILL CROSS THE REGION TODAY AND THIS EVENING. ADVISORY LEVEL GUSTS ARE EXPECTED AT ALL NEARSHORES...BUT AS WE REMAIN IN A TIGHT GRADIENT BEHIND THE FRONT...IN STRONG COLD ADVECTION...ADVISORY LEVEL GUSTS ARE A BETTER BET. THE FRONT WILL BRING A BAND OF SHOWERS AND STORMS...SOME OF WHICH MAY BE STRONG WITH SOME GUSTY WINDS AND HAIL. STRONG COLD ADVECTION CONTINUES INTO MONDAY WITH LAKE EFFECT RAIN SHOWERS (AND A FEW RUMBLES OF THUNDER AGAIN POSSIBLE). OTHER ISSUES COME ABOUT...LIKE THE NEED TO MONITOR FOR POSSIBLE WATERSPOUTS...ESPECIALLY LATER MONDAY THROUGH TUESDAY. SIMPLE PATTERN RECOGNITION OF ANOMALOUSLY DEEP MID AND UPPER LEVEL LOW CENTERED NEARBY THIS TIME OF YEAR SURE SUPPORTS SUCH. EARLY INDICATIONS OF SEVERAL VORT LOBES/ATTENDANT SURFACE TROUGHS ROTATING AROUND PARENT CIRCULATION...FURTHER ENHANCING LOW LEVEL CONVERGENCE. LAKE INDUCED EQUILIBRIUM LEVELS SOARING TO OVER 20 KFT DURING THIS PERIOD...WHICH FAVORS UPPER LEVEL LOW ASSOCIATED WATERSPOUTS PER THE SZILAGYI WATERSPOUT NOMOGRAM. WILL STILL NOT SPECIFICALLY INTRODUCE THIS POTENTIAL IN THE FORECAST...BUT VERY WELL MAY NEED TO IN LATER FORECASTS. && .APX WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR MIZ008-015-016- 019>021-025-031. LH...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR LMZ323-341-342- 344>346. LS...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LSZ321-322. && $$ UPDATE...JSL NEAR TERM...SMD SHORT TERM...MSB LONG TERM...MSB AVIATION...SMD MARINE...SMD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
728 AM EDT SUN AUG 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 401 AM EDT SUN AUG 23 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV/ CUTOFF H5 LO DRIFTING INTO WRN MN. THIS DISTURBANCE CAUSED 12Z-24Z H5/H3 HGT FALLS OF 150M/220M AT BISMARCK. SHARPLY DIFFLUENT UPR FLOW/AREA OF DPVA AND SHARP DEEP LYR QVECTOR CNVGC IN ADVANCE OF THIS FEATURE AND OVER ATTENDANT COLD FNT/WARM CONVEYOR BELT MSTR RIBBON /00Z PWAT 1.50 INCH TO AS HI AS 1.93 INCH AT INL WITHIN THIS MSTR BAND/ IS SUPPORTING BAND OF SCT-NMRS SHOWERS/TS STRETCHING FM THE MN ARROWHEAD/ADJOINING ONTARIO THRU WRN LK SUP INTO THE MID MS RIVER VALLEY. THE 00Z GRB RAOB WAS RELATIVELY DRY AND CAPPED...SO THE WX OVER UPR MI IN ADVANCE OF THE FNT/SHOWERS HAS BEEN RELATIVELY QUIET EXCEPT FOR GUSTY S WINDS UNDER THE TIGHT PRES GRADIENT BTWN RETREATING HI PRES OVER THE NE STATES AND 995MB SFC LO DRIFTING NEWD IN NW ONTARIO. AS THE SHOWERS HAVE MOVED E TOWARD UPR MI INTO THIS MORE STABLE AIRMASS IN THE PRESENCE OF NOCTURNAL COOLING...THE LTG INTENSITY HAS DIMINISHED. LOOKING FARTHER TO THE W...A WELL DEFINED DRY SLOT HAS ENDED THE PCPN FARTHER W IN MN...BUT MORE SHOWERS AND EVEN A FEW TS ARE EVIDENT OVER THE DAKOTAS MOVING INTO FAR WRN MN UNDER SHARP COMMA HEAD CLD MASS ASSOCIATED WITH THE SHRTWV. MAIN FCST CONCERNS TODAY WL BE ON TIMING/COVERAGE OF WARM CONVEYOR BELT SHOWERS/TS AND THEN WRAP ARND MSTR/SHOWERS TNGT AS CUTOFF LO IN MN DRIFTS TO THE E AND OVER NRN LK SUP BY 12Z MON. STRONG WNW WINDS WL IMPACT MAINLY THE WRN ZNS LATE TODAY/TNGT UNDER THE TIGHTER PRES GRADIENT ON THE SW FLANK OF DEEP SFC LO PRES STACKED UNDER THE CLOSED UPR LO. TODAY...AS CLOSED/STACKED LO DRIFTS TO JUST NW OF THUNDER BAY BY 00Z...SFC COLD FNT IS FCST TO REACH IWD BY 12Z...CENTRAL UPR MI BY 18Z AND THEN NEWBERRY BY 00Z. AREA OF DPVA/DEEP LYR QVECTOR CNVGC AND SHARP UPR DVGC IN LEFT EXIT OF SUPPORTING H3 JET MAX MOVING E ON THE SRN FLANK OF THE CLOSED LO OVER THE WARM CONVEYOR BELT MSTR RIBBON AHEAD OF THE FNT SHOULD SUPPORT RELATIVELY NARROW BAND OF NMRS SHOWERS. EXPECT THESE SHOWERS...WITH SOME EMBEDDED TS MAINTAINED BY HEALTHY DYNAMIC FORCING DESPITE MODEST MUCAPE NO MORE THAN 200-400 J/KG...TO SWING W-E ACRS THE CWA WITH THE FNT. ARRIVAL OF DRY SLOTTING BEHIND THE FROPA/WARM CONVEYOR BELT WL BRING A QUICK DIMINISHING TREND TO THE PCPN. SOME PREVIOUS MODELS HAD SUGGESTED DAYTIME HEATING IN THE PRESENCE OF LINGERING DEEP LYR QVECTOR CNVGC WITHIN THE DRY SLOT MIGHT RESULT IN MORE INSTABILITY SHOWERS/TS... BUT FCST SDNGS NOW INDICATE THE DRYING WL BE TOO OVERWHELMING. AREA OF BACKWASH MSTR UNDER CYC W FLOW NOW PUSHING INTO WRN MN WL THEN OVERSPREAD THE W HALF. AS H85 TEMPS FALL TOWARD 5-6C OVER THE W BY 00Z IN THE STRONG LLVL CAA...LLVL LAPSE RATES WL INCRS AND ALLOW FOR EXTENSIVE SC/SOME SHOWERS/MORE EFFICIENT MIXING OF 30-35KT H925 W WINDS TO THE SFC. TEMPS ARE LIKELY TO FALL THIS AFTN OVER THE W WITH THE CAA/CLDY SKIES. TNGT...THE CLOSED/STACKED LO IS FCST TO DRIFT SLOWLY SE AND OVER NRN LK SUP BY 12Z MON. THE TIGHTER PRES GRADIENT/H925 W WINDS UP TO 30- 35KTS UNDER THE H85 THERMAL TROF ON THE SW FLANK OF THE SFC LO ARE FCST TO IMPACT MAINLY THE W AND SCENTRAL CWA AND RESULT IN SOME GUSTY WINDS...ESPECIALLY AT EXPOSED LOCATIONS NEAR LK SUP. H85 TEMPS AS LO AS 2-4C /WATER TEMPS OVER WRN LK SUP ARE AS HI AS 15-17C/ ADVECTING INTO THE FAR W WL SUPPORT SOME LK EFFECT SHOWERS OVER MAINLY THE HIER TERRAIN OF THE NW HALF. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 312 AM EDT SUN AUG 23 2015 THE NEARLY VERTICALLY STACKED SURFACE AND UPPER LOW AT 12Z MONDAY WILL BE SLOWLY MOVING EAST ACROSS NORTHERN ONTARIO AND WILL CONTINUE THAT PATH THROUGH TUESDAY NIGHT BEFORE FINALLY BECOMING CAUGHT UP IN THE NORTHERN STREAM FLOW AND QUICKLY LIFTING NORTHEAST THROUGH QUEBEC ON WEDNESDAY/THURSDAY. THIS WILL LEAD TO A VERY FALL LIKE START TO THE WORK WEEK WITH BREEZY WEST-NORTHWEST WINDS...PERIODS OF LAKE EFFECT/ENHANCED RAIN AND TEMPERATURES WELL BELOW NORMAL. WITH ABUNDANT MOISTURE WRAPPING AROUND THE UPPER/SURFACE LOW...EXPECT PLENTY OF LOW CLOUDS (AND SCATTERED TO NUMEROUS SHOWERS) ACROSS THE U.P. FOR MONDAY INTO AT LEAST WEDNESDAY MORNING. THE MAIN QUESTION WILL BE HOW COLD THE 850MB TEMPS WILL BE TO THE SOUTHWEST OF THE LOW IN ONTARIO. MODELS VARY IN THE EXACT VALUE...WITH THE NAM THE COLDEST AT 0-1C AND THE REST IN THE 2.5-4C RANGE FOR MONDAY AND THEN GRADUALLY WARMING THROUGH TUESDAY. THE EXACT VALUE DOESN/T MATTER TOO MUCH...AS THE TEMPERATURES ALOFT WILL BE COLD ENOUGH FOR LAKE ENHANCED/EFFECT RAIN WITH WESTERN LAKE SUPERIOR TEMPERATURES AROUND 15-17C. THEREFORE...WILL SHOW LIKELY TO DEFINITE VALUES FOR THE FAVORED WEST-NORTHWEST WIND AREAS ON MONDAY AND TRANSITION TO MORE NORTHWESTERLY FOR MONDAY NIGHT INTO TUESDAY. IN ADDITION...WILL HAVE THE HIGHEST POPS OVER THE FAVORED UPSLOPE LOCATIONS FOR THE MONDAY INTO TUESDAY PERIOD (AREAS FROM THE SPINE OF THE KEWEENAW THROUGH IRONWOOD). THAT UPSLOPE FORCING WILL BE DUE TO THE WEST-NORTHWEST WINDS ON MONDAY AND THEN TRANSITION TO MORE NORTHWESTERLY ON MONDAY NIGHT AS THE SURFACE-850MB LOW SHIFTS EAST AND CLOSER TO JAMES BAY AND THE SURFACE TROUGH MOVES EAST ACROSS THE UPPER GREAT LAKES. THAT NORTHWESTERLY LOW LEVEL FLOW WILL CONTINUE INTO WEDNESDAY...POTENTIALLY TURNING A LITTLE MORE NORTH-NORTHWEST. THE STRONGEST WINDS WILL OCCUR MONDAY INTO MONDAY NIGHT (GUSTS OF 20- 30KTS OVER THE WESTERN U.P.) WITH THE TIGHTEST PRESSURE GRADIENT AS THE SURFACE LOW IS JUST TO THE NORTH OF LAKE SUPERIOR. THEN THE WINDS WILL GRADUALLY DIMINISH TUESDAY INTO WEDNESDAY AS THE LOW WEAKENS/BROADENS AS IT MOVES INTO NORTHEAST ONTARIO. THE THIRD ITEM OF NOTE TO START THE WEEK WILL BE THE VERY FALL LIKE HIGHS ACROSS THE AREA ON MONDAY. WITH PLENTY OF CLOUDS AND SHOWERS...HAVE OPTED TO FOLLOW THE RAW MODELS FOR HIGHS ON MONDAY...WHICH GIVES LOW-MID 50S OVER THE WEST AND MID-UPPER 50S OVER THE EAST. THIS IS ABOUT 20 DEGREES BELOW NORMAL AND IN SOME AREAS THEY WILL BE NEARING RECORD COLD HIGH TEMPERATURES. THE RECORD FOR OUR OFFICE IS 56 DEGREES (1978/1971) AND WE WILL BE NEAR THAT BOTH AT MIDNIGHT TONIGHT AND AGAIN WITH THE HIGH ON MONDAY AFTERNOON. LOOKING AT THE TIME SHIFTED COOP DATA (NEED TO USE 8/25 VALUES)...MANY SITES HAVE RECORD VALUES IN THE 50S AND SOME OF THE MORE NOTABLE ONES ARE...IRONWOOD 55 IN 1915...HOUGHTON 53 IN 1987 (MIDNIGHT-MIDNIGHT)...IRON MOUNTAIN 59 IN 1940...MUNISING 57 IN 1940...AND 55 IN NEWBERRY IN 1917. THUS...WITH THE GOING FORECAST HIGH TEMPERATURES...THERE WILL BE SEVERAL SPOTS THAT WILL BE NEAR RECORD LOW MAXIMUM VALUES. TEMPERATURES WILL WARM A FEW DEGREES FOR TUESDAY...BUT HIGHS WILL STILL BE IN THE UPPER 50S AND LOWER 60S. DRY AIR FROM THE HIGH BUILDING INTO THE PLAINS ON WEDNESDAY WILL FINALLY BRING AN END TO THE PROLONGED PERIOD OF CLOUDS AND SHOWERS FROM WEST TO EAST ON WEDNESDAY (ALTHOUGH THE CLOUDS MAY LINGER OVER THE FAR EAST INTO THE EVENING HOURS). THAT HIGH PRESSURE RIDGE WILL MOVE OVER THE AREA WEDNESDAY NIGHT AND REMAIN INTO THURSDAY. CLEARING SKIES AND LIGHT WINDS ON WEDNESDAY NIGHT WILL LEAD TO A GOOD RADIATIONAL COOLING NIGHT ACROSS THE AREA AND HAVE LOWER LOWS SOME FROM THE PREVIOUS FORECAST (CLOSER TO THE MEX AND GEM VALUES WHICH TEND TO PERFORM BETTER IN THOSE SITUATIONS). ABUNDANT SUNSHINE ON THURSDAY WILL LEAD TO HIGHS RETURNING TO MORE NORMAL VALUES FOR LATE AUGUST. FINALLY...A COLD FRONT WILL DROP SOUTHEAST ACROSS THE UPPER GREAT LAKES LATE THURSDAY NIGHT INTO FRIDAY...BRINGING A CHANCE FOR SHOWERS/THUNDERSTORMS TO THE U.P.. THINK THE COVERAGE/AMOUNTS WILL LIMITED DUE TO THE LACK OF RETURN FLOW AND EXISTING DRY AIR. THUS...WON/T GO MORE THAN LOW CHANCE POPS FOR NOW AS THE FRONT MOVES THROUGH. A WEAK RIDGE LOOKS TO MOVE OVER THE AREA FOR SATURDAY BEHIND THE FRONT AND SHOULD LEAD TO A DRY DAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 727 AM EDT SUN AUG 23 2015 A BAND OF SHOWERS/PERHAPS AN EMBEDDED TS AHEAD OF A COLD FNT WL RESULT IN A PERIOD OF MVFR CIGS TO CMX AND SAW THIS MRNG BEFORE SURGE OF DRY AIR AHEAD OF VIGOROUS SHRTWV APRCHG FM THE W ALLOWS FOR A PERIOD OF VFR CONDITIONS THAT WL BE MOVING INTO IWD AT TAF ISSUANCE. BUT AREA OF MOISTER LLVL AIR MOVING E THRU MN WL BRING A RETURN OF MVFR CIGS THIS AFTN AT IWD AND THEN CMX WITH INCRSG UPSLOPE W WIND ARND DEEP LO PRES IN NW ONTARIO. GUSTY W WINDS AND MVFR CONDITIONS WL DOMINATE IWD/CMX TNGT. DOWNSLOPE NATURE OF THIS FLOW AT SAW SUGGESTS VFR WX WL PREDOMINATE THERE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 312 AM EDT SUN AUG 23 2015 A FALL LIKE LOW PRESSURE SYSTEM CURRENTLY TO THE NORTH OF THE LAKE OF THE WOODS WILL BRING WINDY CONDITIONS TO LAKE SUPERIOR THROUGH THE FIRST HALF OF THE UPCOMING WORK WEEK AS IT SLOWLY MOVES EAST ACROSS NORTHERN ONTARIO. GUSTY SOUTHERLY WINDS WILL CONTINUE THIS MORNING AHEAD OF A COLD FRONT OVER WESTERN LAKE SUPERIOR...BUT AS IT MOVES EAST ACROSS THE REST OF THE LAKE TODAY IT WILL SHIFT WINDS TO THE WEST AND LEAD TO GALES TO 35 KNOTS FOR PORTIONS OF WESTERN LAKE SUPERIOR THIS AFTERNOON AND EXPANDING ACROSS THE REST OF THE WESTERN HALF OF THE LAKE TONIGHT AND CONTINUING INTO MONDAY. WITH THE LOW SLOWLY WEAKENING MONDAY NIGHT INTO TUESDAY AS IT NEARS JAMES BAY...THE WINDS WILL GRADUALLY DIMINISH AND TURN TO THE NORTHWEST. HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES REGION FOR WEDNESDAY AND THURSDAY..WHICH WILL LOWER WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 2 PM EDT /1 PM CDT/ THIS AFTERNOON TO 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 2 AM TO 8 PM EDT MONDAY FOR LSZ265. GALE WARNING FROM 8 PM EDT /7 PM CDT/ THIS EVENING TO 5 PM EDT /4 PM CDT/ MONDAY FOR LSZ240>244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 AM EDT SUN AUG 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 401 AM EDT SUN AUG 23 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV/ CUTOFF H5 LO DRIFTING INTO WRN MN. THIS DISTURBANCE CAUSED 12Z-24Z H5/H3 HGT FALLS OF 150M/220M AT BISMARCK. SHARPLY DIFFLUENT UPR FLOW/AREA OF DPVA AND SHARP DEEP LYR QVECTOR CNVGC IN ADVANCE OF THIS FEATURE AND OVER ATTENDANT COLD FNT/WARM CONVEYOR BELT MSTR RIBBON /00Z PWAT 1.50 INCH TO AS HI AS 1.93 INCH AT INL WITHIN THIS MSTR BAND/ IS SUPPORTING BAND OF SCT-NMRS SHOWERS/TS STRETCHING FM THE MN ARROWHEAD/ADJOINING ONTARIO THRU WRN LK SUP INTO THE MID MS RIVER VALLEY. THE 00Z GRB RAOB WAS RELATIVELY DRY AND CAPPED...SO THE WX OVER UPR MI IN ADVANCE OF THE FNT/SHOWERS HAS BEEN RELATIVELY QUIET EXCEPT FOR GUSTY S WINDS UNDER THE TIGHT PRES GRADIENT BTWN RETREATING HI PRES OVER THE NE STATES AND 995MB SFC LO DRIFTING NEWD IN NW ONTARIO. AS THE SHOWERS HAVE MOVED E TOWARD UPR MI INTO THIS MORE STABLE AIRMASS IN THE PRESENCE OF NOCTURNAL COOLING...THE LTG INTENSITY HAS DIMINISHED. LOOKING FARTHER TO THE W...A WELL DEFINED DRY SLOT HAS ENDED THE PCPN FARTHER W IN MN...BUT MORE SHOWERS AND EVEN A FEW TS ARE EVIDENT OVER THE DAKOTAS MOVING INTO FAR WRN MN UNDER SHARP COMMA HEAD CLD MASS ASSOCIATED WITH THE SHRTWV. MAIN FCST CONCERNS TODAY WL BE ON TIMING/COVERAGE OF WARM CONVEYOR BELT SHOWERS/TS AND THEN WRAP ARND MSTR/SHOWERS TNGT AS CUTOFF LO IN MN DRIFTS TO THE E AND OVER NRN LK SUP BY 12Z MON. STRONG WNW WINDS WL IMPACT MAINLY THE WRN ZNS LATE TODAY/TNGT UNDER THE TIGHTER PRES GRADIENT ON THE SW FLANK OF DEEP SFC LO PRES STACKED UNDER THE CLOSED UPR LO. TODAY...AS CLOSED/STACKED LO DRIFTS TO JUST NW OF THUNDER BAY BY 00Z...SFC COLD FNT IS FCST TO REACH IWD BY 12Z...CENTRAL UPR MI BY 18Z AND THEN NEWBERRY BY 00Z. AREA OF DPVA/DEEP LYR QVECTOR CNVGC AND SHARP UPR DVGC IN LEFT EXIT OF SUPPORTING H3 JET MAX MOVING E ON THE SRN FLANK OF THE CLOSED LO OVER THE WARM CONVEYOR BELT MSTR RIBBON AHEAD OF THE FNT SHOULD SUPPORT RELATIVELY NARROW BAND OF NMRS SHOWERS. EXPECT THESE SHOWERS...WITH SOME EMBEDDED TS MAINTAINED BY HEALTHY DYNAMIC FORCING DESPITE MODEST MUCAPE NO MORE THAN 200-400 J/KG...TO SWING W-E ACRS THE CWA WITH THE FNT. ARRIVAL OF DRY SLOTTING BEHIND THE FROPA/WARM CONVEYOR BELT WL BRING A QUICK DIMINISHING TREND TO THE PCPN. SOME PREVIOUS MODELS HAD SUGGESTED DAYTIME HEATING IN THE PRESENCE OF LINGERING DEEP LYR QVECTOR CNVGC WITHIN THE DRY SLOT MIGHT RESULT IN MORE INSTABILITY SHOWERS/TS... BUT FCST SDNGS NOW INDICATE THE DRYING WL BE TOO OVERWHELMING. AREA OF BACKWASH MSTR UNDER CYC W FLOW NOW PUSHING INTO WRN MN WL THEN OVERSPREAD THE W HALF. AS H85 TEMPS FALL TOWARD 5-6C OVER THE W BY 00Z IN THE STRONG LLVL CAA...LLVL LAPSE RATES WL INCRS AND ALLOW FOR EXTENSIVE SC/SOME SHOWERS/MORE EFFICIENT MIXING OF 30-35KT H925 W WINDS TO THE SFC. TEMPS ARE LIKELY TO FALL THIS AFTN OVER THE W WITH THE CAA/CLDY SKIES. TNGT...THE CLOSED/STACKED LO IS FCST TO DRIFT SLOWLY SE AND OVER NRN LK SUP BY 12Z MON. THE TIGHTER PRES GRADIENT/H925 W WINDS UP TO 30- 35KTS UNDER THE H85 THERMAL TROF ON THE SW FLANK OF THE SFC LO ARE FCST TO IMPACT MAINLY THE W AND SCENTRAL CWA AND RESULT IN SOME GUSTY WINDS...ESPECIALLY AT EXPOSED LOCATIONS NEAR LK SUP. H85 TEMPS AS LO AS 2-4C /WATER TEMPS OVER WRN LK SUP ARE AS HI AS 15-17C/ ADVECTING INTO THE FAR W WL SUPPORT SOME LK EFFECT SHOWERS OVER MAINLY THE HIER TERRAIN OF THE NW HALF. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 312 AM EDT SUN AUG 23 2015 THE NEARLY VERTICALLY STACKED SURFACE AND UPPER LOW AT 12Z MONDAY WILL BE SLOWLY MOVING EAST ACROSS NORTHERN ONTARIO AND WILL CONTINUE THAT PATH THROUGH TUESDAY NIGHT BEFORE FINALLY BECOMING CAUGHT UP IN THE NORTHERN STREAM FLOW AND QUICKLY LIFTING NORTHEAST THROUGH QUEBEC ON WEDNESDAY/THURSDAY. THIS WILL LEAD TO A VERY FALL LIKE START TO THE WORK WEEK WITH BREEZY WEST-NORTHWEST WINDS...PERIODS OF LAKE EFFECT/ENHANCED RAIN AND TEMPERATURES WELL BELOW NORMAL. WITH ABUNDANT MOISTURE WRAPPING AROUND THE UPPER/SURFACE LOW...EXPECT PLENTY OF LOW CLOUDS (AND SCATTERED TO NUMEROUS SHOWERS) ACROSS THE U.P. FOR MONDAY INTO AT LEAST WEDNESDAY MORNING. THE MAIN QUESTION WILL BE HOW COLD THE 850MB TEMPS WILL BE TO THE SOUTHWEST OF THE LOW IN ONTARIO. MODELS VARY IN THE EXACT VALUE...WITH THE NAM THE COLDEST AT 0-1C AND THE REST IN THE 2.5-4C RANGE FOR MONDAY AND THEN GRADUALLY WARMING THROUGH TUESDAY. THE EXACT VALUE DOESN/T MATTER TOO MUCH...AS THE TEMPERATURES ALOFT WILL BE COLD ENOUGH FOR LAKE ENHANCED/EFFECT RAIN WITH WESTERN LAKE SUPERIOR TEMPERATURES AROUND 15-17C. THEREFORE...WILL SHOW LIKELY TO DEFINITE VALUES FOR THE FAVORED WEST-NORTHWEST WIND AREAS ON MONDAY AND TRANSITION TO MORE NORTHWESTERLY FOR MONDAY NIGHT INTO TUESDAY. IN ADDITION...WILL HAVE THE HIGHEST POPS OVER THE FAVORED UPSLOPE LOCATIONS FOR THE MONDAY INTO TUESDAY PERIOD (AREAS FROM THE SPINE OF THE KEWEENAW THROUGH IRONWOOD). THAT UPSLOPE FORCING WILL BE DUE TO THE WEST-NORTHWEST WINDS ON MONDAY AND THEN TRANSITION TO MORE NORTHWESTERLY ON MONDAY NIGHT AS THE SURFACE-850MB LOW SHIFTS EAST AND CLOSER TO JAMES BAY AND THE SURFACE TROUGH MOVES EAST ACROSS THE UPPER GREAT LAKES. THAT NORTHWESTERLY LOW LEVEL FLOW WILL CONTINUE INTO WEDNESDAY...POTENTIALLY TURNING A LITTLE MORE NORTH-NORTHWEST. THE STRONGEST WINDS WILL OCCUR MONDAY INTO MONDAY NIGHT (GUSTS OF 20- 30KTS OVER THE WESTERN U.P.) WITH THE TIGHTEST PRESSURE GRADIENT AS THE SURFACE LOW IS JUST TO THE NORTH OF LAKE SUPERIOR. THEN THE WINDS WILL GRADUALLY DIMINISH TUESDAY INTO WEDNESDAY AS THE LOW WEAKENS/BROADENS AS IT MOVES INTO NORTHEAST ONTARIO. THE THIRD ITEM OF NOTE TO START THE WEEK WILL BE THE VERY FALL LIKE HIGHS ACROSS THE AREA ON MONDAY. WITH PLENTY OF CLOUDS AND SHOWERS...HAVE OPTED TO FOLLOW THE RAW MODELS FOR HIGHS ON MONDAY...WHICH GIVES LOW-MID 50S OVER THE WEST AND MID-UPPER 50S OVER THE EAST. THIS IS ABOUT 20 DEGREES BELOW NORMAL AND IN SOME AREAS THEY WILL BE NEARING RECORD COLD HIGH TEMPERATURES. THE RECORD FOR OUR OFFICE IS 56 DEGREES (1978/1971) AND WE WILL BE NEAR THAT BOTH AT MIDNIGHT TONIGHT AND AGAIN WITH THE HIGH ON MONDAY AFTERNOON. LOOKING AT THE TIME SHIFTED COOP DATA (NEED TO USE 8/25 VALUES)...MANY SITES HAVE RECORD VALUES IN THE 50S AND SOME OF THE MORE NOTABLE ONES ARE...IRONWOOD 55 IN 1915...HOUGHTON 53 IN 1987 (MIDNIGHT-MIDNIGHT)...IRON MOUNTAIN 59 IN 1940...MUNISING 57 IN 1940...AND 55 IN NEWBERRY IN 1917. THUS...WITH THE GOING FORECAST HIGH TEMPERATURES...THERE WILL BE SEVERAL SPOTS THAT WILL BE NEAR RECORD LOW MAXIMUM VALUES. TEMPERATURES WILL WARM A FEW DEGREES FOR TUESDAY...BUT HIGHS WILL STILL BE IN THE UPPER 50S AND LOWER 60S. DRY AIR FROM THE HIGH BUILDING INTO THE PLAINS ON WEDNESDAY WILL FINALLY BRING AN END TO THE PROLONGED PERIOD OF CLOUDS AND SHOWERS FROM WEST TO EAST ON WEDNESDAY (ALTHOUGH THE CLOUDS MAY LINGER OVER THE FAR EAST INTO THE EVENING HOURS). THAT HIGH PRESSURE RIDGE WILL MOVE OVER THE AREA WEDNESDAY NIGHT AND REMAIN INTO THURSDAY. CLEARING SKIES AND LIGHT WINDS ON WEDNESDAY NIGHT WILL LEAD TO A GOOD RADIATIONAL COOLING NIGHT ACROSS THE AREA AND HAVE LOWER LOWS SOME FROM THE PREVIOUS FORECAST (CLOSER TO THE MEX AND GEM VALUES WHICH TEND TO PERFORM BETTER IN THOSE SITUATIONS). ABUNDANT SUNSHINE ON THURSDAY WILL LEAD TO HIGHS RETURNING TO MORE NORMAL VALUES FOR LATE AUGUST. FINALLY...A COLD FRONT WILL DROP SOUTHEAST ACROSS THE UPPER GREAT LAKES LATE THURSDAY NIGHT INTO FRIDAY...BRINGING A CHANCE FOR SHOWERS/THUNDERSTORMS TO THE U.P.. THINK THE COVERAGE/AMOUNTS WILL LIMITED DUE TO THE LACK OF RETURN FLOW AND EXISTING DRY AIR. THUS...WON/T GO MORE THAN LOW CHANCE POPS FOR NOW AS THE FRONT MOVES THROUGH. A WEAK RIDGE LOOKS TO MOVE OVER THE AREA FOR SATURDAY BEHIND THE FRONT AND SHOULD LEAD TO A DRY DAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 124 AM EDT SUN AUG 23 2015 S-SW WINDS WILL REMAIN GUSTY INTO THE OVERNIGHT TO 25-30KT THEN SLOWLY DIMINISH PRIOR TO DAYBREAK SUNDAY...BEFORE INCREASING AGAIN BEHIND A COLD FRONTAL PASSAGE. EXPECT VFR CONDITIONS TO LOWER TO MVFR LATE TONIGHT WITH THE ARRIVAL OF SHRA/TSRA ALONG APPROACHING COLD FRONT FROM THE W. ALTHOUGH SOME BRIEF IMPROVEMENT TO VFR MAY HAPPEN AT IWD LATE SUN MORNING AND AT SAW IN THE AFTERNOON...WRAP AROUND MOISTURE AND SCATTERED LAKE-ENHANCED SHRA WILL LIKELY BRING CEILINGS BACK TO MVFR BY LATE AFTERNOON/SUN EVENING AT IWD AND CMX IN ONSHORE WESTERLY FLOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 312 AM EDT SUN AUG 23 2015 A FALL LIKE LOW PRESSURE SYSTEM CURRENTLY TO THE NORTH OF THE LAKE OF THE WOODS WILL BRING WINDY CONDITIONS TO LAKE SUPERIOR THROUGH THE FIRST HALF OF THE UPCOMING WORK WEEK AS IT SLOWLY MOVES EAST ACROSS NORTHERN ONTARIO. GUSTY SOUTHERLY WINDS WILL CONTINUE THIS MORNING AHEAD OF A COLD FRONT OVER WESTERN LAKE SUPERIOR...BUT AS IT MOVES EAST ACROSS THE REST OF THE LAKE TODAY IT WILL SHIFT WINDS TO THE WEST AND LEAD TO GALES TO 35 KNOTS FOR PORTIONS OF WESTERN LAKE SUPERIOR THIS AFTERNOON AND EXPANDING ACROSS THE REST OF THE WESTERN HALF OF THE LAKE TONIGHT AND CONTINUING INTO MONDAY. WITH THE LOW SLOWLY WEAKENING MONDAY NIGHT INTO TUESDAY AS IT NEARS JAMES BAY...THE WINDS WILL GRADUALLY DIMINISH AND TURN TO THE NORTHWEST. HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES REGION FOR WEDNESDAY AND THURSDAY..WHICH WILL LOWER WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 2 PM EDT /1 PM CDT/ THIS AFTERNOON TO 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162-263-264. GALE WARNING FROM 2 AM TO 8 PM EDT MONDAY FOR LSZ265. GALE WARNING FROM 8 PM THIS EVENING TO 5 PM EDT MONDAY FOR LSZ243-244. GALE WARNING FROM 8 AM EDT /7 AM CDT/ TO 5 PM EDT /4 PM CDT/ MONDAY FOR LSZ240>242. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...VOSS MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 AM EDT SUN AUG 23 2015 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/MARINE .SYNOPSIS... ISSUED AT 330 AM EDT SUN AUG 23 2015 A COLD FRONT WILL MOVE EAST THROUGH LOWER MICHIGAN TODAY BRINGING A PERIOD OF SHOWERS AND THUNDERSTORMS AND USHERING IN FALL LIKE WEATHER. COOL AND BREEZY CONDITIONS WITH CONSIDERABLE CLOUDINESS AND SCATTERED SHOWERS CAN BE EXPECTED MONDAY THROUGH WEDNESDAY WITH HIGHS STRUGGLING TO REACH 70 DEGREES. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 330 AM EDT SUN AUG 23 2015 THE FOCUS IN THE SHORT TERM CONTINUES TO BE ON CONVECTIVE POTENTIAL TODAY AND THE MARGINAL RISK OF A FEW STRONG TO SEVERE STORMS. LATEST GUIDANCE SHOWS A RATHER NARROW NORTH-SOUTH ORIENTED BAND OF INSTABILITY... ONLY ABOUT 50 MILES WIDE... MARCHING EAST THROUGH THE AREA TODAY AHEAD OF APPROACHING SFC COLD FRONT. MU CAPES WITHIN THIS BAND MAX OUT AROUND 1000 J/KG...REACHING THE LAKESHORE AROUND NOON AND EXITING THE LANSING/JACKSON AREA AROUND 6-7 PM. HIGH POPS FOR SHOWERS AND TSTMS...GREATER THAN 60-70 PCT...APPEAR TO BE IN ORDER TODAY AS SHORTWAVE ROTATES TROUGH BASE OF INCREASINGLY NEGATIVELY TILTED UPR TROUGH PIVOTING NE THROUGH MN/WI. HOWEVER THERE IS ONLY ABOUT A 3-4 HOUR WINDOW WHEN SHOWERS AND TSTMS WILL BE IMPACTING ANY GIVEN LOCATION. AS FAR AS SEVERE WEATHER POTENTIAL... MARGINAL IS CERTAINLY THE APPROPRIATE TERM. THE BETTER STRONG DEEP LAYER SHEAR IN EXCESS OF 50 KTS LAGS BEHIND THE COLD FRONT... BUT STILL ROUGHLY 35 KTS IS PROGGED TO BE CONICIDENT WITH THE NARROW RIBBON OF INSTABILITY AND THIS DOES SUPPORT THE POTENTIAL FOR A FEW ORGANIZED STORMS. RUC FCST SOUNDINGS SHOW SKINNY CAPE PROFILES AND MARGINAL MID LEVEL LAPSE RATES OF ONLY AROUND 6 C/KM SUGGESTING WEAK UPDRAFT POTENTIAL. BELIEVE THE MAIN THREAT FOR A FEW STRONG OR PERHAPS SEVERE CELLS TO DEVELOP IS EAST OF HIGHWAY 131 THIS AFTERNOON. THIS IS WHERE BETTER CHANCE OF STONGER INSOLATION EXISTS THAT COULD OVERCOME WEAK CIN AND YIELD DECENT SFC BASED INSTABILITY. MAIN THREAT IS LOCALIZED DAMAGING WIND GUSTS. THE REST OF THE FCST IS PRETTY STRAIGHTFORWARD. DEEP CYCLONIC FLOW AND STRONG COLD ADVECTION... COMBINED WITH LAKE INDUCED INSTABILITY... WILL YIELD EXTENSIVE STRATO CUMULUS CLOUDS MONDAY INTO TUESDAY ALONG WITH SCATTERED TO NUMERSOU RAIN SHOWERS. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 AM EDT SUN AUG 23 2015 THE TREND OVER THE PAST DAY HAS BEEN FOR THE COOLER AIR AND RAIN SHOWER ACTIVITY TO LINGER OVER THE AREA A BIT LONGER INTO THE LONG TERM. THIS OCCURS AS THE UPPER LOW HOLDS IN FOR AT LEAST ANOTHER DAY AND IS REINFORCED BY ADDITIONAL SHORT WAVE ACTIVITY DIVING IN ON ITS BACKSIDE. THIS WILL HOLD SHOWER ACTIVITY INTO WED ALONG WITH TEMPS STRUGGLING TO REACH 70 WITH H850 TEMPS REMAINING BELOW 8C. LATEST MODEL TRENDS DO PUSH OUT THE LOW BY THU AND ALLOW THE AREA TO DRY OUT AND TEMPS TO MODERATE A BIT AS WE BECOME UNDER THE INFLUENCE OF THE CONFLUENCE DOWNSTREAM OF THE UPPER RIDGE AXIS TO OUR WEST. THIS DRY WEATHER COULD LAST INTO FRI...HOWEVER THE CHC OF RAIN WILL BE GRADUALLY INCREASING THROUGH FRI AND FRI NIGHT. THE INCREASE IN RAIN CHCS THROUGH FRI AND FRI NIGHT AND INTO SAT COMES AS A RESULT OF ADDITIONAL SHORT WAVE ENERGY DIVING SE OUT OF CANADA AND BRINGING A COLD FRONT IN. THERE ARE SOME DISCREPANCIES WITH REGARD TO THE TIMING DEPENDING ON THE POTENTIAL DEVELOPMENT OF THE WAVE INTO A LOW VIA THE ECMWF. WE ARE NOT BETTING ON THIS SOLUTION YET AS THE EURO TENDS TO OVERDEVELOP DEVELOPING SYSTEMS. SOME WARMER AIR WILL COME IN AHEAD OF THIS WAVE AND ASSOCIATED SFC FRONT FOR EARLY NEXT WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 152 AM EDT SUN AUG 23 2015 OUR MAIN FOCUS WITH THIS SET OF FCSTS CONTINUES TO BE THE SHOWERS AND STORMS THAT ARE EXPECTED TO ACCOMPANY THE COLD FRONT MAINLY THIS AFTERNOON INTO EARLY THIS EVENING. THE WEATHER SHOULD BE QUIET UNTIL THE RAIN MOVES IN WITH VFR CONDITIONS EXPECTED THROUGH MOST OF THE MORNING. WE ARE EXPECTING THAT THE SHOWERS WILL BEGIN TO MOVE IN ACROSS THE LAKESHORE TOWARD LATE MORNING...AND THEN SPREAD EAST THROUGH THE AFTERNOON. WE ARE EXPECTING MAINLY SHOWERS FOR THE WRN TERMINALS WITH A CHC OF THUNDER. THE ERN TERMINALS WILL HAVE A BETTER THREAT FOR THUNDER WITH SOME DIURNAL HEATING. MVFR WILL BE LIKELY IN THE SHOWERS/STORMS WITH SOME SPOTTY IFR POSSIBLE. SHOWERS/STORMS WILL LIKELY MOVE OUT AFTER ONLY IMPACTING ANY ONE LOCATION FOR A FEW HOURS. IT LOOKS LIKE ALL OF THE RAIN SHOULD BE EAST OF THE TERMINALS BY 23-00Z. SKIES WILL CLEAR AND SOME GUSTY WINDS WILL BE POSSIBLE BEFORE SUNSET. WINDS SHOULD THEN DECOUPLE. && .MARINE... ISSUED AT 330 AM EDT SUN AUG 23 2015 NO CHANGES ARE PLANNED TO THE ONGOING MARINE HEADLINES. INITIALLY WINDS GET CRANKING THIS MORNING OUT OF THE SOUTH AHEAD OF THE COLD FRONT... CAUSING HIGHEST WAVES NORTH OF HOLLAND. THEN THE WEST WINDS BEHIND THE FRONT YIELD WIDESPREAD 6-8 FOOTERS AREA WIDE TONIGHT THROUGH MONDAY NIGHT. THE OTHER MARINE CONCERN IS FOR WATERSPOUT POTENTIAL ON TUESDAY AS THE WIND SPEEDS DIMINISH A BIT. && .HYDROLOGY... ISSUED AT 1111 AM EDT SAT AUG 22 2015 CONCERNS FOR FLOODING REMAIN LOW OVER THE NEXT WEEK. RAIN CHANCES ARE FAIRLY LIMITED TO SUNDAY WITH MONDAY INTO TUESDAY MAINLY BEING THE LIGHT AND SCATTERED VARIETY. TOTALS CONTINUE TO BE IN THE BALLPARK OF HALF AN INCH FOR THE PERIOD SPANNING SUNDAY TO TUESDAY. DRY WEATHER SETTLES IN AGAIN ONCE THE SYSTEM DEPARTS TO THE NORTH AND EAST. RAINFALL IS EXPECTED TO DO NOTHING MORE THAN A BENEFICIAL SOAKING FOR THE FORECAST AREA. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM 8 AM EDT THIS MORNING THROUGH MONDAY EVENING FOR MIZ037-043-050-056-064-071. LM...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 8 PM EDT MONDAY FOR LMZ844>849. && $$ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...NJJ AVIATION...NJJ HYDROLOGY...JAM MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GAYLORD MI
205 AM EDT SUN AUG 23 2015 .UPDATE... ISSUED AT 1051 PM EDT SAT AUG 22 2015 SKIES REMAIN CLEAR ACROSS OUR ENTIRE CWA LATE THIS EVENING BETWEEN HIGH PRESSURE CENTERED EAST OF MICHIGAN AND A STRONG COLD FRONT NOW MOVING INTO THRU THE UPPER MISSISSIPPI VALLEY. LONG LINE OF STRONG/SVR CONVECTION REMAINS ALONG AND JUST AHEAD OF THE FRONT. LEADING EDGE OF THIS CONVECTION IS STILL WELL WEST OF OUR CWA OVER WRN WISCONSIN. LATEST NAM12...RAP13 AND HRRR ALL SUGGEST THAT THIS CONVECTION WILL NOT REACH OUR CWA UNTIL AFTER 12...ACTUALLY MORE TOWARD 15Z. DO EXPECT SOME INCREASE IN MID/HIGH CLOUDS FOR THE FAR WRN SECTIONS OF OUR CWA OVERNIGHT AS ASSOCIATED CLOUD COVER REMAINS CLOSE TO THE FRONT ITSELF. && .NEAR TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 328 PM EDT SAT AUG 22 2015 HIGH IMPACT WEATHER: NONE OVERVIEW...THE MAIN CONCERN WITH THE FORECAST PACKAGE IS THE STORMS SYSTEM WEST OF US. THE MAIN LOW IS CURRENTLY SOUTH OF LAKE WINNIPEG, WITH A WARM FRONT THAT JUTS EAST, IN NW ONTARIO, AND A COLD FRONT THAT STRETCHES SOUTH INTO EASTERN NORTH DAKOTA, TO A SFC LOW IN SOUTH DAKOTA, THEN SOUTHWEST THROUGH NEBRASKA AND WEST BACK INTO THE INTERMOUNTAIN WEST. AT 500 MB, THE TROUGH TO THE WEST, JUST BEHIND THE SFC LOW, HAS AN AXIS THAT RUNS ALONG THE MONTANA/ND BOARDER AND ANOTHER SHORTWAVE TROUGH MOVING THROUGH THE UPPER MISSISSIPPI VALLEY. OTHERWISE HIGH PRESSURE CENTERED OVER THE LOWER GREAT LAKES WITH THE RETURN FLOW JUST GETTING INTO THE UPPER GREAT LAKES, AND WARMING THE REGION AND PROVIDING THE MOISTURE. TONIGHT...ISOLATED RAIN SHOWERS IN NE LOWER WILL CONTINUE UNTIL ABOUT SUN DOWN, SINCE THE MAIN REASON IS FROM THE DIURNAL CU. AS THESE DIMINISH, THE CLOUDS WILL BEGIN TO CLEAR OUT AS WELL PRODUCING A MAINLY QUIET, CLEAR SKY, WITH A LIGHT WARM BREEZE OVERNIGHT. TEMPERATURES DON`T LOOK LIKE THEY WILL FALL MUCH AS THE RETURN FLOW CONTINUES PUMP WARM AIR INTO THE REGION. IT COULD ALSO HAPPEN THAT THE TEMPERATURES FALL A BIT, AND FLAT LINE IN THE MID TO UPPER 60S OVERNIGHT, BUT IT SEEMS THAT TEMPERATURES WILL FALL INTO THE LOWER TO MID 60S FIRST. AFTER 09Z, WE SHOULD START TO SEE SOME HIGHER CLOUDS ADVANCING INTO THE WESTERN COUNTIES AHEAD OF THE SHOWERS AND THUNDERSTORMS ASSOCIATED WITH COLD FRONT. THERE IS A SMALL CHANCE THAT A SHOWER MAY RUN INTO MANISTEE OR FRANKFORT BETWEEN 09Z AND 12Z, BUT THINK THAT THE MOISTURE AND INSTABILITY LOOKS WEAK AT THIS POINT, SO WILL KEEP IT TO THE WEST SIDE OF LAKE MICHIGAN. && .SHORT TERM...(SUNDAY THROUGH TUESDAY) ISSUED AT 328 PM EDT SAT AUG 22 2015 HIGH IMPACT WEATHER: STRONGER STORMS SUNDAY...WATERSPOUT POTENTIAL MONDAY-MONDAY NIGHT. PATTERN OVERVIEW/FORECAST: LONG WAVE TROUGH HAS SET UP SHOP ACROSS WESTERN CANADA...DIPPING INTO THE NRN CONUS COURTESY OF TWO DISTINCT WAVES ROTATING THROUGH THE LARGER SCALE MEAN TROUGH. ONE PRONOUNCED WAVE IN THE GULF OF ALASKA DELIVERING ACTIVE WEATHER TO THE WEST COAST OF CANADA. SECOND STRONG WAVE (AND OUR MORE IMMEDIATE CONCERN) ADVANCING THROUGH THE NRN PLAINS/SOUTH-CENTRAL CANADA REGION. STRONG UPPER JET STREAK IS DIGGING INTO THE BACKSIDE OF THE WAVE AS A WEDGE OF SUBSTANTIALLY COLDER AIR DIVES THROUGH THE NRN ROCKIES AND HEADING INTO THE NRN PLAINS (AND EVENTUALLY...US). CORRESPONDING DEEPENING SFC LOW IS LOCATED OVER THE DAKOTAS AND ATTENDING COLD FRONT STRETCHING BACK INTO THE ROCKIES. NRN PLAINS WAVE IS FORECAST TO GO "NEGATIVE TILT" AND CARVE OUT A RATHER IMPRESSIVE (AND PSEUDO-CUTOFF) CLOSED LOW OVER THE GREAT LAKES HEADING INTO MONDAY. THIS WILL DELIVER A RATHER UNSEASONABLY COLD POCKET OF AIR TO THE GREAT LAKES AND MIDWEST (SREF GUIDANCE DELIVERS A CORE OF +2C TO +4C 850 MB AIR RIGHT OVER NRN MICHIGAN MONDAY NIGHT INTO TUESDAY). HOWEVER...MEAN LONG WAVE TROUGH IS FORECAST TO REMAIN LARGELY ACROSS WESTERN (OR NORTHWESTERN) NOAM THROUGH THE UPCOMING WEEK...SUGGESTING OUR IMPENDING DIVE INTO EARLY FALL-LIKE WEATHER WILL BE SHORT LIVED AND SHOULD EVENTUALLY TRANSITION BACK OUT TO MORE SEASONABLE READINGS BY LATE IN THE WEEK. SUNDAY...NEGATIVELY TILTED SHORT WAVE TROUGH AXIS WILL BE SWINGING UP THROUGH THE WESTERN GREAT LAKES/NRN MICHIGAN THROUGH THE COURSE OF THE DAY. PARENT OCCLUDING LOW PRESSURE CENTER ADVANCES SLOWLY INTO ONTARIO WITH ATTENDING OCCLUDING/COLD FRONT SLIDING ACROSS THE CWA...MAINLY DURING THE AFTERNOON PER CURRENT GUIDANCE TIMING. AHEAD OF THE FRONT...NARROW AXIS OF MOISTURE/INSTABILITY WILL BE NOSING UP THROUGH THE CWA AHEAD OF THE FRONT AND THERE SHOULD BE PLENTY OF FORCING (UPPER LEVEL HEIGHT FALLS AND LOW LEVEL CONVERGENCE) TO MARCH A TIGHT NARROW CORRIDOR OF SHOWERS AND THUNDERSTORMS ACROSS THE CWA...LATE MORNING THROUGH THE AFTERNOON. HAVE ADDED SOME 3- HOURLY TIMING DETAIL TO THE FORECAST FOR SUNDAY BUT OF COURSE THAT IS SUBJECT TO CHANGE. BUT IN ESSENCE...ANTICIPATED SHOWERS/STORMS TO IMPACT THE WESTERN HALF OF THE CWA THROUGH MIDDAY AND EASTERN HALF DURING THE AFTERNOON INTO EARLY EVENING. SEVERE WEATHER POTENTIAL...DECENT FORCING AND MODESTLY STRONGER WINDS ALOFT/30-40 KNOTS 0-6KM BULK SHEAR COULD SUPPORT SOME STRONGER UPDRAFTS PARTICULARLY DOWN TOWARD SAGINAW BAY INTO SRN LOWER MICHIGAN. INSTABILITY IS NOT SO IMPRESSIVE HOWEVER...BUT GIVEN THE STRONG DYNAMICS/KINEMATICS...CERTAINLY CANNOT RULE OUT A MARGINAL SEVERE WEATHER THREAT TOMORROW AFTERNOON...ESPECIALLY ACROSS THE S/SE PART OF THE CWA WHERE BEST INSTABILITY AND STRONGER SHEAR WILL BE FOUND. SUNDAY NIGHT-TUESDAY...SIMPLY STATED...TURNING FALL-LIKE WITH RAIN SHOWERS. SORT OF A TRANSITION PERIOD SUNDAY NIGHT THROUGH EARLY MONDAY AS COLD FRONT AND NARROW LINE OF SHOWERS/STORMS EXIT ACROSS LAKE HURON EARLY SUNDAY EVENING...AND WE GET SOME SEMBLANCE OF A DRY SLOT SLIPPING THROUGH THE REGION THROUGH MONDAY MORNING. CORE OF COLDEST AIR ARRIVES MONDAY NIGHT...BUT INITIAL COLD ADVECTION BEHIND THE FRONT DROPS LOW LEVEL TEMPS (H8) TO AROUND 7C SUNDAY NIGHT. AND WITH SOME BETTER MOISTURE STARTING TO ROTATE THROUGH UPPER MICHIGAN/NRN LAKE MICHIGAN...WILL PROBABLY SEE SOME LAKE EFFECT/ENHANCED RAIN SHOWERS GET GOING AS EARLY AS SUNDAY NIGHT THROUGH MONDAY MORNING. BUT THE REALLY GOOD STUFF WILL RAMP UP LATER MONDAY AND MONDAY NIGHT AS SECONDARY SFC TROUGH/COLD FRONT SWINGS THROUGH USHERING IN EVEN COLDER AIR (<4C) AND (MORE IMPORTANTLY) SOME QG-FORCING FOR ASCENT AND BETTER MOISTURE. LAKE EFFECT/HEATING INDUCED RAIN SHOWERS SHOULD REALLY TAKE OFF MONDAY AFTERNOON AND PERSIST THROUGH MONDAY NIGHT AS WELL AS MUCH OF TUESDAY. WILL CARRY SOME HEFTY POPS ACROSS MUCH OF THE CWA THROUGH THAT TIME WITH AN EMPHASIS ACROSS THE USUAL W-NW LAKE EFFECT AREAS. DON/T HAVE SMALL HAIL/GRAUPEL MENTIONED JUST YET BECAUSE THE NEEDED INSTABILITY JUST DOESN/T APPEAR TO BE THERE. BUT SOMETHING TO KEEP IN MIND AS WELL. TEMPS...STILL RELATIVELY WARM ON SUNDAY. COLDER AIR SPILLS IN SUNDAY NIGHT AND WE THEN STRUGGLE IN THE 60S BOTH MONDAY AND TUESDAY FOR MOST AREAS. TUESDAY IS THE "COLDEST" AND I WOULDN/T BE SURPRISED TO SEE A FEW SPOTS (GAYLORD) NOT MAKE IT OUT OF THE 50S (HAVE UNDERCUT ALL GUIDANCE MAX TEMPS FOR TUESDAY). && .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 328 PM EDT SAT AUG 22 2015 RAIN CHANCES WILL BEGIN TO DIMINISH FOR EASTERN PARTS OF THE STATE TUESDAY NIGHT GOING INTO WEDNESDAY AS THE CUTOFF LOW OVER ONTARIO LIFTS INTO QUEBEC. HOWEVER...WILL HAVE TO DIVERGE A BIT FROM BLENDED MODEL GUIDANCE GOING INTO THURSDAY FOR WESTERN PORTIONS OF THE STATE. WITH SUFFICIENT MOISTURE LOOKING TO STAY AROUND...AND H8 TEMPS REMAINING LOW ENOUGH FOR LAKE PROCESSES TO KICK IN...WILL ADD CHANCE POPS FOR SOME POSSIBLE LAKE EFFECT SHOWERS TO STICK AROUND THROUGH THURSDAY. WILL ALSO LEAVE CHANCE POPS OVER THE WEEKEND...AS A QUICK MOVING SHORTWAVE DIVING THROUGH CANADA AND A COLD FRONT ATTENDANT TO LOW PRESSURE NEAR HUDSON BAY TRANSITING THE AREA COULD HELP TO KICK OFF SOME SHOWERS. AFTER A COUPLE OF COOL DAYS...TEMPERATURES SHOULD MODERATE THROUGH THE EXTENDED PERIOD GETTING BACK TO NEAR NORMAL FOR MOST AREAS BY SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 157 AM EDT SUN AUG 23 2015 ...STORMS AND PERIODS OF MVFR ON THE WAY... A WEDGE OF DRY AIR WILL WORK INTO THE REGION THROUGH DAYBREAK KEEPING SKIES CLEAR. A COLD FRONT THEN PUSHES THROUGH NRN MICHIGAN THROUGH THE DAY BRINGING A BAND OF SHOWERS AND STORMS...A FEW OF WHICH MAY BE ABLE TO BECOME SEVERE WITH DAMAGING WINDS BEING THE MAIN THREAT...SOME STRONGER CELLS COULD PRODUCE SOME HAIL. THIS BAND ARRIVES NW LOWER MID TO LATE MORNING...AND ACROSS APN MID TO LATE AFTERNOON. THE BAND OF SHOWERS AS WELL AS IN THE COOL AIR BEHIND THE FRONT WILL BRING PERIODIC MVFR CIGS AND VSBYS. SUNDAY NIGHT CONTINUED COOLING WILL BRING THE DEVELOPMENT OF LAKE EFFECT RAIN SHOWERS TO PLN. S/SW WINDS WILL BE GUSTY INITIALLY AHEAD OF THE FRONT...LONGEST PERIOD OF GUSTINESS ACROSS APN. GUSTS MAY DISAPPEAR FOR AWHILE WITHIN THE BAND OF RAIN...BUT WILL PICK UP AGAIN BEHIND THE FRONT OUT OF THE W/NW. THIS GUSTY CONDITION WILL CONTINUE ACROSS NW LOWER THROUGH SUNDAY NIGHT. && .MARINE... ISSUED AT 328 PM EDT SAT AUG 22 2015 TONIGHT THROUGH MONDAY...WINDS TONIGHT WILL BEGIN TO INCREASE ESPECIALLY AFTER 06Z/SUN AS THE SFC HIGH MOVES EAST AND THE GRADIENT TIGHTENS THROUGH THE NIGHT. BY SUNDAY MORNING (AROUND 12Z) THE WINDS SHOULD BE HIGH ENOUGH ALONG THE LAKE MICHIGAN AND SHORE AND IN WHITEFISH BAY FOR SMALL CRAFT ADVISORIES. WITH THE COLD FRONT MOVING ACROSS THE LAKE SUNDAY MORNING, AND THEN ACROSS NORTHERN MICHIGAN DURING THE DAY, WILL EXPECT THAT LAKE HURON WILL GET IN ON THE ACT, SO SMALL CRAFT ADVISORIES WILL BE ADDED FOR THERE AS WELL. THE ADVISORIES WILL CONTINUE INTO THE NIGHT POST-FRONTAL, ALTHOUGH WITH THE SFC LOW MOVING OVER LAKE SUPERIOR, THE GRADIENT WILL SLACKEN SO THE SMALL CRAFT WON`T BE NEEDED FOR WHITEFISH BAY AND THE ST. MARY`S RIVER. IT LOOKS LIKE WE WILL PROBABLY NEED TO CONTINUE THE ADVISORIES INTO MONDAY AS THE GRADIENT STILL LOOKS FAIRLY TIGHT OVER N LOWER. IN ADDITION TO THE GUSTY WINDS/HIGHER WAVES...AN UNSEASONABLY COLD AIRMASS WILL SLIP ACROSS THE GREAT LAKES MONDAY THROUGH TUESDAY...DELIVERING WIDESPREAD LAKE EFFECT RAIN SHOWERS. WATERSPOUTS WILL ALSO BE A POSSIBILITY WITH THE BEST TIMEFRAME LOOKING TO BE MONDAY AFTERNOON THROUGH MONDAY NIGHT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 6 AM EDT MONDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 AM EDT MONDAY FOR LMZ323-341-342-344>346. LS...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR LSZ321-322. && $$ UPDATE...MLR NEAR TERM...JSL SHORT TERM...ADAM LONG TERM...ALM AVIATION...SMD MARINE...ADAM
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1239 PM CDT SUN AUG 23 2015 .UPDATE... ISSUED AT 1228 PM CDT SUN AUG 23 2015 ANOTHER UPDATE FOR POPS/QPF/TEMPS TO MATCH TRENDS. HELD ONTO CLOUD COVER IN THE SOUTH AND WEST A BIT LONGER WITH THIS UPDATE AS WELL. A FEW AUTOMATED GAUGES WERE REPORTING MORE THAN FOUR TENTHS OF AN INCH OF RAIN THIS MORNING AS THE SHOWERS MOVED THROUGH...SO NUDGED QPF HIGHER. ALSO PUSHED THE HIGHER POPS A LITTLE FARTHER EASTWARD THROUGH THIS AFTERNOON. UPDATE ISSUED AT 918 AM CDT SUN AUG 23 2015 MINOR UPDATE TO INCREASE POPS/QPF AND ADJUST HOURLY AND MAX TEMPS DOWN SLIGHTLY TO BETTER MATCH TRENDS. AREA OF SHOWERS HAS EXPANDED OVER MN ZONES IN THE PAST FEW HOURS...SO HAVE INCREASED POPS OVER THOSE AREAS. THINK SCATTERED VERY LIGHT SHOWERS WILL AFFECT NW WI TOO...SO NUDGED POPS UP THERE AS WELL. TOOK QPF A LITTLE HIGHER... ESPECIALLY THROUGH 18Z TO BETTER ACCOUNT FOR RADAR TRENDS. TEMPS WERE NOT RECOVERING AS QUICKLY AS GOING FORECAST SUGGESTED...SO TAMPED TEMPS DOWN AND CLOSER TO HRRR GUIDANCE. UPDATE ISSUED AT 638 AM CDT SUN AUG 23 2015 UPDATED FOR THE NEW 12Z AVIATION DISCUSSION BELOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT SUN AUG 23 2015 THE STRONG SURFACE LOW OVER NORTHWEST ONTARIO WITH A COLD FRONT EXTENDING SOUTH ACROSS THE FORECAST AREA AND DOWN INTO WESTERN WISCONSIN AND INTO IOWA. A TROUGH AXIS ALSO EXTENDS DOWN INTO THE RED RIVER VALLEY TO EASTERN SOUTH DAKOTA. ABOVE THIS...A TROWAL EXTENDS INTO NORTHERN MINNESOTA WITH AN AREA OF SHOWERS AND SOME THUNDERSTORMS. THE ASSOCIATED UPPER LOW IS OVER NORTHERN MINNESOTA. THIS WHOLE SYSTEM WILL MOVE SLOWLY NORTHEAST TODAY AND TONIGHT...BECOMING MORE STACKED WITH TIME AND MORE CUT OFF AT UPPER LEVELS. THIS IS GOING TO LEAVE US WITH CYCLONIC FLOW AND PLENTY OF SHOWERS AND CLOUD COVER. THE TROWAL IS GOING TO ROTATE ACROSS THE NORTHERN FORECAST AREA TODAY...AND EVEN THIS EVENING BEFORE WEAKENING OVERNIGHT. HAVE KEPT POPS HIGHEST ALONG THE NORTHERN BORDER CLOSEST TO THE SURFACE LOW AND UNDER THE TROWAL...BUT TAPER OFF TO DRY OR SLIGHT CHANCE TO THE SOUTH. THIS IS ALSO GOING TO KEEP TEMPERATURES VERY COOL...WITH HIGHS ONLY IN THE UPPER 50S NORTH TO LOW 60S SOUTH. THEN...TONIGHT THE CLOUD COVER IS GOING TO PULL EAST SOME...AND ALONG WITH THE STRONG COLD AIR ADVECTION ALLOW TEMPERATURES TO DROP INTO THE 40S OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 347 AM CDT SUN AUG 23 2015 A DEEP AREA OF LOW PRESSURE NORTH OF LAKE SUPERIOR WILL GRADUALLY SHIFT INTO FAR NE ONTARIO FROM MONDAY MORNING THROUGH TUESDAY...THEN HEAD INTO WESTERN QUEBEC ON WEDNESDAY. THIS LOW WILL CONTINUE TO BRING THE NORTHLAND A PROLONGED PERIOD OF COOL AND BREEZY NORTHERLY FLOW FOR THE EARLY PART OF THE WEEK...BUT WITH A TRANSITION TO SUNNY AND SEASONABLY WARM WEATHER BY WEDNESDAY WHEN HIGH PRESSURE MOVES INTO THE REGION. THIS WILL BRING A GRADUAL DAILY WARMING TREND INTO THE MIDDLE OF THE WEEK...WITH HIGHS OF 10 TO 15 DEGREES BELOW NORMAL ON MONDAY BECOMING NEAR NORMAL BY WEDNESDAY. ISOLATED TO SCATTERED RAIN SHOWERS ARE EXPECTED OVER THE NORTHERN AND EASTERN FORECAST AREA FOR MONDAY DUE TO THE DAYTIME HEATING AND RESULTING LOW LEVEL LAPSE RATES. SHOWERS ARE ALSO POSSIBLE TUESDAY...BUT MAINLY OVER THE ARROWHEAD. SOUTHERLY RETURN FLOW WILL DEVELOP THURSDAY...CONTINUING THE WARMING TREND. SUNNY SKIES AND THE SOUTHERLY BREEZE SHOULD ALLOW HIGHS TO REACH SLIGHTLY ABOVE NORMAL. A SHORTWAVE TROUGH PASSAGE COULD BRING SHOWERS AND STORMS LATE THURSDAY INTO FRIDAY. THE MODELS ARE LACKING AGREEMENT FOR THE END OF THE WEEK. THE GFS HAS A WARM FRONT NEAR THE SOUTHERN FORECAST AREA AND ASSOCIATED PCPN FOR FRIDAY NIGHT AND SATURDAY...WHILE THE ECMWF HAS SURFACE HIGH PRESSURE OVER MINNESOTA AND WISCONSIN WITH MOSTLY DRY WEATHER FOR THE NORTHLAND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1228 PM CDT SUN AUG 23 2015 WIDESPREAD MVFR CIGS ACROSS THE REGION TODAY WITH A STRONG PUSH OF COLD AIR FROM THE NORTH KEEPING A LAYER OF STRATO-CU AROUND THROUGH AT LEAST THE NEXT 24 HOURS. COULD SEE A FEW SHOWERS MIXED IN AT TIMES...ESPECIALLY FROM INL TO HIB TO HYR. GUSTY WEST/NW WINDS WILL PERSIST THROUGH THE PERIOD AS WELL WITH NOT MUCH RELIEF THROUGH THE OVERNIGHT HOURS. && .PRELIMINARY POINT TEMPS/POPS... DLH 59 48 58 48 / 100 60 20 20 INL 57 43 56 45 / 100 70 30 0 BRD 61 49 66 48 / 60 20 0 0 HYR 61 48 60 47 / 80 30 10 0 ASX 64 48 59 51 / 100 40 20 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT MONDAY FOR LSZ121-140>148. && $$ UPDATE...HUYCK SHORT TERM...LE LONG TERM...GROCHOCINSKI AVIATION...TENTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
919 AM CDT SUN AUG 23 2015 .UPDATE... ISSUED AT 918 AM CDT SUN AUG 23 2015 MINOR UPDATE TO INCREASE POPS/QPF AND ADJUST HOURLY AND MAX TEMPS DOWN SLIGHTLY TO BETTER MATCH TRENDS. AREA OF SHOWERS HAS EXPANDED OVER MN ZONES IN THE PAST FEW HOURS...SO HAVE INCREASED POPS OVER THOSE AREAS. THINK SCATTERED VERY LIGHT SHOWERS WILL AFFECT NW WI TOO...SO NUDGED POPS UP THERE AS WELL. TOOK QPF A LITTLE HIGHER... ESPECIALLY THROUGH 18Z TO BETTER ACCOUNT FOR RADAR TRENDS. TEMPS WERE NOT RECOVERING AS QUICKLY AS GOING FORECAST SUGGESTED...SO TAMPED TEMPS DOWN AND CLOSER TO HRRR GUIDANCE. UPDATE ISSUED AT 638 AM CDT SUN AUG 23 2015 UPDATED FOR THE NEW 12Z AVIATION DISCUSSION BELOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT SUN AUG 23 2015 THE STRONG SURFACE LOW OVER NORTHWEST ONTARIO WITH A COLD FRONT EXTENDING SOUTH ACROSS THE FORECAST AREA AND DOWN INTO WESTERN WISCONSIN AND INTO IOWA. A TROUGH AXIS ALSO EXTENDS DOWN INTO THE RED RIVER VALLEY TO EASTERN SOUTH DAKOTA. ABOVE THIS...A TROWAL EXTENDS INTO NORTHERN MINNESOTA WITH AN AREA OF SHOWERS AND SOME THUNDERSTORMS. THE ASSOCIATED UPPER LOW IS OVER NORTHERN MINNESOTA. THIS WHOLE SYSTEM WILL MOVE SLOWLY NORTHEAST TODAY AND TONIGHT...BECOMING MORE STACKED WITH TIME AND MORE CUT OFF AT UPPER LEVELS. THIS IS GOING TO LEAVE US WITH CYCLONIC FLOW AND PLENTY OF SHOWERS AND CLOUD COVER. THE TROWAL IS GOING TO ROTATE ACROSS THE NORTHERN FORECAST AREA TODAY...AND EVEN THIS EVENING BEFORE WEAKENING OVERNIGHT. HAVE KEPT POPS HIGHEST ALONG THE NORTHERN BORDER CLOSEST TO THE SURFACE LOW AND UNDER THE TROWAL...BUT TAPER OFF TO DRY OR SLIGHT CHANCE TO THE SOUTH. THIS IS ALSO GOING TO KEEP TEMPERATURES VERY COOL...WITH HIGHS ONLY IN THE UPPER 50S NORTH TO LOW 60S SOUTH. THEN...TONIGHT THE CLOUD COVER IS GOING TO PULL EAST SOME...AND ALONG WITH THE STRONG COLD AIR ADVECTION ALLOW TEMPERATURES TO DROP INTO THE 40S OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 347 AM CDT SUN AUG 23 2015 A DEEP AREA OF LOW PRESSURE NORTH OF LAKE SUPERIOR WILL GRADUALLY SHIFT INTO FAR NE ONTARIO FROM MONDAY MORNING THROUGH TUESDAY...THEN HEAD INTO WESTERN QUEBEC ON WEDNESDAY. THIS LOW WILL CONTINUE TO BRING THE NORTHLAND A PROLONGED PERIOD OF COOL AND BREEZY NORTHERLY FLOW FOR THE EARLY PART OF THE WEEK...BUT WITH A TRANSITION TO SUNNY AND SEASONABLY WARM WEATHER BY WEDNESDAY WHEN HIGH PRESSURE MOVES INTO THE REGION. THIS WILL BRING A GRADUAL DAILY WARMING TREND INTO THE MIDDLE OF THE WEEK...WITH HIGHS OF 10 TO 15 DEGREES BELOW NORMAL ON MONDAY BECOMING NEAR NORMAL BY WEDNESDAY. ISOLATED TO SCATTERED RAIN SHOWERS ARE EXPECTED OVER THE NORTHERN AND EASTERN FORECAST AREA FOR MONDAY DUE TO THE DAYTIME HEATING AND RESULTING LOW LEVEL LAPSE RATES. SHOWERS ARE ALSO POSSIBLE TUESDAY...BUT MAINLY OVER THE ARROWHEAD. SOUTHERLY RETURN FLOW WILL DEVELOP THURSDAY...CONTINUING THE WARMING TREND. SUNNY SKIES AND THE SOUTHERLY BREEZE SHOULD ALLOW HIGHS TO REACH SLIGHTLY ABOVE NORMAL. A SHORTWAVE TROUGH PASSAGE COULD BRING SHOWERS AND STORMS LATE THURSDAY INTO FRIDAY. THE MODELS ARE LACKING AGREEMENT FOR THE END OF THE WEEK. THE GFS HAS A WARM FRONT NEAR THE SOUTHERN FORECAST AREA AND ASSOCIATED PCPN FOR FRIDAY NIGHT AND SATURDAY...WHILE THE ECMWF HAS SURFACE HIGH PRESSURE OVER MINNESOTA AND WISCONSIN WITH MOSTLY DRY WEATHER FOR THE NORTHLAND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 638 AM CDT SUN AUG 23 2015 GUSTY WNW WINDS...IFR/MVFR CEILINGS...AND RAINS SHOWERS WILL DEVELOP THIS MORNING AS AN UPPER LEVEL LOW OVER FAR NORTHERN MINNESOTA LIFTS INTO NW ONTARIO. THE CEILINGS SHOULD LIFT FOR MOST TERMINALS WITH A TRANSITION BACK TO VFR BY LATER THIS AFTERNOON. HOWEVER...KINL WILL LIKELY REMAIN MVFR. WIND GUSTS COULD EXCEED 35 KNOTS THIS AFTERNOON AND EVENING AS COOL AIR POURS OUT OF CANADA. THE CEILINGS WILL LIKELY LOWER AGAIN TONIGHT BACK TO MVFR. HOWEVER...KBRD WILL LIKELY CLEAR TO VFR. THE CEILINGS WILL INHIBIT RADIATIONAL COOLING...AND COULD HELP MAINTAIN THE GUSTY WINDS WELL INTO THE EVENING. WHEREAS THE WINDS SHOULD SIGNIFICANTLY WEAKEN AT KBRD DUE TO THE CLEARING SKIES. && .PRELIMINARY POINT TEMPS/POPS... DLH 61 48 58 48 / 90 50 20 20 INL 59 43 56 45 / 90 80 30 0 BRD 63 49 66 48 / 60 10 0 0 HYR 62 48 60 47 / 50 20 10 0 ASX 65 48 59 51 / 60 30 20 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT MONDAY FOR LSZ121-140>148. && $$ UPDATE...HUYCK SHORT TERM...LE LONG TERM...GROCHOCINSKI AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1007 PM EDT MON AUG 24 2015 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL CROSS THE AREA FROM TODAY THROUGH TUESDAY BRINGING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS. AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE OVER THE GREAT LAKES REGION THROUGH MID WEEK, AND PROVIDE FOR UNSETTLED WEATHER IN THE NORTHEAST. LATER IN THE WEEK THE UPPER LEVEL LOW WILL MAKE ITS MOVE EAST, CONTINUING THE CHANCES FOR RAIN. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 1006 PM EDT MONDAY...EARLIER STRONG THUNDERSTORM WHICH DEVELOPED VICINITY OF NEWCOMB NY HAS WEAKENED A BIT, BUT IS NOW OVER THE NY SIDE OF CHAMPLAIN VALLEY NEAR PLATTSBURGH. STILL A GOOD AMOUNT OF LIGHTNING OCCURRING DESPITE SCANT INSTABILITY AND IS PRODUCING LOCALIZED OUTFLOW (NORTHERLY GUSTS TO 21 KNOTS RECENTLY OBSERVED AT BTV AIRPORT). THAT ONGOING THUNDERSTORM WILL CONTINUE TO LIFT NORTHWARD INTO CANADA WITHIN THE NEXT HOUR OR SO, WITH REMNANT SHOWERS SPREADING INTO THE VT SIDE OF THE CHAMPLAIN VALLEY. MEANWHILE, ADDITIONAL SHOWERS AND ISOLATED STORMS ARE EVIDENT IN COMPOSITE RADAR IMAGERY FROM ALBANY TO EAST OF BINGHAMTON NY. LATEST HRRR CONTINUES TO SUGGEST THAT THIS RENEWED DEVELOPMENT WILL SPREAD NORTH-NORTHEAST INTO SOUTHERN VT AND SOUTHERN CHAMPLAIN VALLEY REGION THROUGH OVERNIGHT AS THE FRONT SLOWS/STALLS. POPS STILL GENERALLY ON TRACK, SO NO CHANGES TO POPS OR WX WITH THIS UPDATE. UPDATED THE FORECAST WITH CURRENT OBSERVATIONAL DATA. LOWS 50S TO MID 60S, WARMEST IN VT WITH GREATER CLOUD COVER. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 358 PM EDT MONDAY... THE FRONT REMAINS IN EASTERN VERMONT TUESDAY BEFORE EVENTUALLY MOVING EAST INTO NH TUESDAY AFTERNOON. MODELS INDICATING THERE WILL STILL BE SOME INSTABILITY OF 500-1000 J/KG CAPE EAST OF THE GREEEN MOUNTAINS SO KEEPING SHOWERS AND THUNDERSTORMS IN THE FORECAST THERE DECREASING TO A SLIGHT CHANCE FURTHER WEST. HIGHS MAINLY IN THE 70S TO NEAR 80. THE FRONT PUSHES EAST OF THE REGION TUESDAY NIGHT BUT THERE MAY BE SOME LAKE EFFECT RAIN SHOWERS DEVELOPING OVER LAKE ONTARIO AS COOLER AIR MOVES OVER THE WARM WATERS OF THE LAKE. THESE SHOWERS WILL BE MAINLY IN SOUTHERN AND WESTERN ST. LAWRENCE COUNTY AND WESTERN ADIRONDACKS. LOW TEMPS MAINLY IN THE 50S. COOLER WEATHER EXPECTED WEDNESDAY AND WEDNESDAY NIGHT WITH CYCLONIC FLOW AND COOL AIR ALOFT. THERE IS ALSO A CHANCE OF SHOWERS OR SPRINKLES ACROSS THE NORTH WITH A LITTLE BIT OF INSTABILITY IN THE AFTERNOON AND EVENING. HIGHS IN THE 70S. LOWS IN THE 50S. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 405 PM EDT MONDAY...ECMWF AND GFS MODELS IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. AN UPPER TROUGH WILL MOVE ACROSS THE REGION ON THURSDAY...SO HAVE CONTINUED TO CARRY CHANCE POPS FOR SHOWERS ON THURSDAY. A RIDGE OF HIGH PRESSURE WILL BUILD NORTHEAST FROM THE OHIO VALLEY THURSDAY NIGHT. THIS RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SUNDAY. THUS...HAVE GONE WITH A DRY FORECAST FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. ON MONDAY...ECMWF AND GFS MODELS SHOW SOME DIFFERENCES WITH THE ECMWF SHOWING A BUILDING UPPER RIDGE AND CONTINUED DRY WEATHER. THE GFS MODEL ON MONDAY SHOWING WESTERLIES OVER THE REGION ALONG WITH A SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS. FORECASTER CONFIDENCE IS LOW FOR MONDAY...SO HAVE JUST GONE WITH SUPER-BLEND SLIGHT CHANCE POPS ON MONDAY. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... THROUGH 00Z WEDNESDAY...WEAK AND RELATIVELY SLOW-MOVING COLD FRONT IS ASSOCIATED WITH ISOLD SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NRN ADIRONDACKS AT 2330Z. THIS ACTIVITY WILL GRADUALLY SHIFT EWD INTO WRN VT...POSSIBILIY AFFECTING BTV/RUT 02-04Z. ANY IMPACTS WILL BE BRIEF AT THE TERMINALS. GENERALLY LOOKING AT VFR CONDITIONS OUTSIDE OF SHOWER/TSTM ACTIVITY. SCT- BKN050-070 CONDITIONS FOR THE BALANCE OF THE OVERNIGHT HOURS SHOULD PRECLUDE FOG FORMATION. DURING THE DAYLIGHT HRS TUESDAY...ISOLD SHOWERS/TSTMS REMAIN POSSIBLE ACROSS ERN VT...GENERALLY EAST OF THE TAF LOCATIONS. WINDS GENERALLY LIGHT SW 5-8 KTS. OUTLOOK 00Z WEDNESDAY THROUGH SATURDAY... 00Z WEDNESDAY THROUGH 00Z FRIDAY...MAINLY VFR WITH BRIEF MVFR IN SHOWERS WITH SLOW MOVING FRONT AND UPPER LOW OVER CANADA IN THE VICINITY. COVERAGE OF ACTIVITY SHOULD BE MOST FOCUSED DURING THE AFTERNOON AND EARLY EVENING HOURS EACH DAY. 00Z FRIDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED UNDER A RIDGE OF HIGH PRESSURE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...LOCONTO/SISSON SHORT TERM...SISSON LONG TERM...WGH AVIATION...BANACOS/WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
733 PM EDT MON AUG 24 2015 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL CROSS THE AREA FROM TODAY THROUGH TUESDAY BRINGING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS. AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE OVER THE GREAT LAKES REGION THROUGH MID WEEK, AND PROVIDE FOR UNSETTLED WEATHER IN THE NORTHEAST. LATER IN THE WEEK THE UPPER LEVEL LOW WILL MAKE ITS MOVE EAST, CONTINUING THE CHANCES FOR RAIN. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 706 PM EDT MONDAY...FRONT WHICH EXTENDS FROM THE ADIRONDACKS TO THE POCONOS REGION OF PA CONTINUES TO PUSH TOWARD THE CHAMPLAIN VALLEY. WHILE SHOWER/THUNDERSTORM ACTIVITY IN THE NORTHERN ADIRONDACKS HAS BEEN FEW AND FAR BETWEEN UP TO THIS POINT, A GREATER CONVECTIVE COVERAGE EXISTS FROM THE CENTRAL ADIRONDACKS SOUTHWARD TO THE PA BORDER. INSTABILITY IS A BIT HIGHER IN THIS REGION, SURFACE WINDS ARE MORE BACKED ALLOWING FOR BETTER LOW- LEVEL CONVERGENCE AND IN A REGION OF FAVORABLE UPPER- LEVEL DIVERGENCE. INSTABILITY ALREADY IS PRETTY LIMITED WITH AROUND 1000 J/KG AND INCREASING CONVECTIVE INHIBITION DUE TO CLOUD SHIELD AND SETTING SUN. RECENT HRRR AND 12Z WRF- ARW SIMULATED REFLECTIVITY PROGS HAS THE IDEA THAT AT LEAST SHOWERS WILL RE- DEVELOP IN THE CHAMPLAIN VALLEY AS THE FRONT BEGINS TO STALL AFTER MIDNIGHT. EXPECT THE GREATEST COVERAGE OF SHOWERS/STORMS THROUGH MIDNIGHT TO BE WITH SOUTHERN EXTENT (PRIMARILY ESSEX NY INTO ADDISON/RUTLAND COUNTIES VT) THROUGH MIDNIGHT, WITH A FURTHER INCREASE AFTER MIDNIGHT. BASED ON RADAR TRENDS TO THE SOUTH AND INCREASE IN SHOWER/POSSIBLE STORM COVERAGE AFTER MIDNIGHT, ONLY CHANGES WERE TO ADJUST POPS A BIT BASED ON RADAR TRENDS AND GO WITH AREAL COVERAGE WORDING FOR SHOWERS/STORMS. LOW TEMPS MAINLY IN THE 60S BUT A FEW 50S IN NORTHERN NY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 358 PM EDT MONDAY... THE FRONT REMAINS IN EASTERN VERMONT TUESDAY BEFORE EVENTUALLY MOVING EAST INTO NH TUESDAY AFTERNOON. MODELS INDICATING THERE WILL STILL BE SOME INSTABILITY OF 500-1000 J/KG CAPE EAST OF THE GREEEN MOUNTAINS SO KEEPING SHOWERS AND THUNDERSTORMS IN THE FORECAST THERE DECREASING TO A SLIGHT CHANCE FURTHER WEST. HIGHS MAINLY IN THE 70S TO NEAR 80. THE FRONT PUSHES EAST OF THE REGION TUESDAY NIGHT BUT THERE MAY BE SOME LAKE EFFECT RAIN SHOWERS DEVELOPING OVER LAKE ONTARIO AS COOLER AIR MOVES OVER THE WARM WATERS OF THE LAKE. THESE SHOWERS WILL BE MAINLY IN SOUTHERN AND WESTERN ST. LAWRENCE COUNTY AND WESTERN ADIRONDACKS. LOW TEMPS MAINLY IN THE 50S. COOLER WEATHER EXPECTED WEDNESDAY AND WEDNESDAY NIGHT WITH CYCLONIC FLOW AND COOL AIR ALOFT. THERE IS ALSO A CHANCE OF SHOWERS OR SPRINKLES ACROSS THE NORTH WITH A LITTLE BIT OF INSTABILITY IN THE AFTERNOON AND EVENING. HIGHS IN THE 70S. LOWS IN THE 50S. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 405 PM EDT MONDAY...ECMWF AND GFS MODELS IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. AN UPPER TROUGH WILL MOVE ACROSS THE REGION ON THURSDAY...SO HAVE CONTINUED TO CARRY CHANCE POPS FOR SHOWERS ON THURSDAY. A RIDGE OF HIGH PRESSURE WILL BUILD NORTHEAST FROM THE OHIO VALLEY THURSDAY NIGHT. THIS RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SUNDAY. THUS...HAVE GONE WITH A DRY FORECAST FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. ON MONDAY...ECMWF AND GFS MODELS SHOW SOME DIFFERENCES WITH THE ECMWF SHOWING A BUILDING UPPER RIDGE AND CONTINUED DRY WEATHER. THE GFS MODEL ON MONDAY SHOWING WESTERLIES OVER THE REGION ALONG WITH A SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS. FORECASTER CONFIDENCE IS LOW FOR MONDAY...SO HAVE JUST GONE WITH SUPER-BLEND SLIGHT CHANCE POPS ON MONDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... THROUGH 00Z WEDNESDAY...WEAK AND RELATIVELY SLOW-MOVING COLD FRONT IS ASSOCIATED WITH ISOLD SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NRN ADIRONDACKS AT 2330Z. THIS ACTIVITY WILL GRADUALLY SHIFT EWD INTO WRN VT...POSSIBILIY AFFECTING BTV/RUT 02-04Z. ANY IMPACTS WILL BE BRIEF AT THE TERMINALS. GENERALLY LOOKING AT VFR CONDITIONS OUTSIDE OF SHOWER/TSTM ACTIVITY. SCT- BKN050-070 CONDITIONS FOR THE BALANCE OF THE OVERNIGHT HOURS SHOULD PRECLUDE FOG FORMATION. DURING THE DAYLIGHT HRS TUESDAY...ISOLD SHOWERS/TSTMS REMAIN POSSIBLE ACROSS ERN VT...GENERALLY EAST OF THE TAF LOCATIONS. WINDS GENERALLY LIGHT SW 5-8 KTS. OUTLOOK 00Z WEDNESDAY THROUGH SATURDAY... 00Z WEDNESDAY THROUGH 00Z FRIDAY...MAINLY VFR WITH BRIEF MVFR IN SHOWERS WITH SLOW MOVING FRONT AND UPPER LOW OVER CANADA IN THE VICINITY. COVERAGE OF ACTIVITY SHOULD BE MOST FOCUSED DURING THE AFTERNOON AND EARLY EVENING HOURS EACH DAY. 00Z FRIDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED UNDER A RIDGE OF HIGH PRESSURE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...LOCONTO/SISSON SHORT TERM...SISSON LONG TERM...WGH AVIATION...BANACOS/WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
707 PM EDT MON AUG 24 2015 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL CROSS THE AREA FROM TODAY THROUGH TUESDAY BRINGING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS. AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE OVER THE GREAT LAKES REGION THROUGH MID WEEK, AND PROVIDE FOR UNSETTLED WEATHER IN THE NORTHEAST. LATER IN THE WEEK THE UPPER LEVEL LOW WILL MAKE ITS MOVE EAST, CONTINUING THE CHANCES FOR RAIN. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 706 PM EDT MONDAY...FRONT WHICH EXTENDS FROM THE ADIRONDACKS TO THE POCONOS REGION OF PA CONTINUES TO PUSH TOWARD THE CHAMPLAIN VALLEY. WHILE SHOWER/THUNDERSTORM ACTIVITY IN THE NORTHERN ADIRONDACKS HAS BEEN FEW AND FAR BETWEEN UP TO THIS POINT, A GREATER CONVECTIVE COVERAGE EXISTS FROM THE CENTRAL ADIRONDACKS SOUTHWARD TO THE PA BORDER. INSTABILITY IS A BIT HIGHER IN THIS REGION, SURFACE WINDS ARE MORE BACKED ALLOWING FOR BETTER LOW- LEVEL CONVERGENCE AND IN A REGION OF FAVORABLE UPPER- LEVEL DIVERGENCE. INSTABILITY ALREADY IS PRETTY LIMITED WITH AROUND 1000 J/KG AND INCREASING CONVECTIVE INHIBITION DUE TO CLOUD SHIELD AND SETTING SUN. RECENT HRRR AND 12Z WRF- ARW SIMULATED REFLECTIVITY PROGS HAS THE IDEA THAT AT LEAST SHOWERS WILL RE- DEVELOP IN THE CHAMPLAIN VALLEY AS THE FRONT BEGINS TO STALL AFTER MIDNIGHT. EXPECT THE GREATEST COVERAGE OF SHOWERS/STORMS THROUGH MIDNIGHT TO BE WITH SOUTHERN EXTENT (PRIMARILY ESSEX NY INTO ADDISON/RUTLAND COUNTIES VT) THROUGH MIDNIGHT, WITH A FURTHER INCREASE AFTER MIDNIGHT. BASED ON RADAR TRENDS TO THE SOUTH AND INCREASE IN SHOWER/POSSIBLE STORM COVERAGE AFTER MIDNIGHT, ONLY CHANGES WERE TO ADJUST POPS A BIT BASED ON RADAR TRENDS AND GO WITH AREAL COVERAGE WORDING FOR SHOWERS/STORMS. LOW TEMPS MAINLY IN THE 60S BUT A FEW 50S IN NORTHERN NY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 358 PM EDT MONDAY... THE FRONT REMAINS IN EASTERN VERMONT TUESDAY BEFORE EVENTUALLY MOVING EAST INTO NH TUESDAY AFTERNOON. MODELS INDICATING THERE WILL STILL BE SOME INSTABILITY OF 500-1000 J/KG CAPE EAST OF THE GREEEN MOUNTAINS SO KEEPING SHOWERS AND THUNDERSTORMS IN THE FORECAST THERE DECREASING TO A SLIGHT CHANCE FURTHER WEST. HIGHS MAINLY IN THE 70S TO NEAR 80. THE FRONT PUSHES EAST OF THE REGION TUESDAY NIGHT BUT THERE MAY BE SOME LAKE EFFECT RAIN SHOWERS DEVELOPING OVER LAKE ONTARIO AS COOLER AIR MOVES OVER THE WARM WATERS OF THE LAKE. THESE SHOWERS WILL BE MAINLY IN SOUTHERN AND WESTERN ST. LAWRENCE COUNTY AND WESTERN ADIRONDACKS. LOW TEMPS MAINLY IN THE 50S. COOLER WEATHER EXPECTED WEDNESDAY AND WEDNESDAY NIGHT WITH CYCLONIC FLOW AND COOL AIR ALOFT. THERE IS ALSO A CHANCE OF SHOWERS OR SPRINKLES ACROSS THE NORTH WITH A LITTLE BIT OF INSTABILITY IN THE AFTERNOON AND EVENING. HIGHS IN THE 70S. LOWS IN THE 50S. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 405 PM EDT MONDAY...ECMWF AND GFS MODELS IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. AN UPPER TROUGH WILL MOVE ACROSS THE REGION ON THURSDAY...SO HAVE CONTINUED TO CARRY CHANCE POPS FOR SHOWERS ON THURSDAY. A RIDGE OF HIGH PRESSURE WILL BUILD NORTHEAST FROM THE OHIO VALLEY THURSDAY NIGHT. THIS RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SUNDAY. THUS...HAVE GONE WITH A DRY FORECAST FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. ON MONDAY...ECMWF AND GFS MODELS SHOW SOME DIFFERENCES WITH THE ECMWF SHOWING A BUILDING UPPER RIDGE AND CONTINUED DRY WEATHER. THE GFS MODEL ON MONDAY SHOWING WESTERLIES OVER THE REGION ALONG WITH A SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS. FORECASTER CONFIDENCE IS LOW FOR MONDAY...SO HAVE JUST GONE WITH SUPER-BLEND SLIGHT CHANCE POPS ON MONDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... THROUGH 18Z TUESDAY...A WEAK FRONTAL SYSTEM OVER THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK AT 18Z MONDAY WILL MOVE SLOWLY EAST THROUGH THE PERIOD. EXPECTING MAINLY VFR CONDITIONS THROUGH THE PERIOD. ANY LIGHT RAIN SHOWER ACTIVITY WITH THE FRONTAL SYSTEM WILL NOT CAUSE ANY VISIBILITY RESTRICTIONS...WITH VISIBILITIES EXPECTED TO BE 6 STATUTE MILES OR GREATER. OUTLOOK 18Z TUESDAY THROUGH SATURDAY... 18Z TUESDAY THROUGH 00Z FRIDAY...MAINLY VFR WITH BRIEF MVFR IN SHOWERS WITH SLOW MOVING FRONT AND UPPER LOW OVER CANADA IN THE VICINITY. COVERAGE OF ACTIVITY SHOULD BE MOST FOCUSED DURING THE AFTERNOON AND EARLY EVENING HOURS EACH DAY. 00Z FRIDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED UNDER A RIDGE OF HIGH PRESSURE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...LOCONTO/SISSON SHORT TERM...SISSON LONG TERM...WGH AVIATION...WGH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1031 PM EDT MON AUG 24 2015 .SYNOPSIS... HIGH PRESSURE WILL BE CENTERED OFF THE NORTH CAROLINA COAST TONIGHT. A WEAK COLD FRONT APPROACHES FROM THE WEST LATE TONIGHT THEN WILL STALL OVER THE AREA TUESDAY AND WEDNESDAY. THE FRONT WILL THEN SLOWLY MOVE OFF THE COAST WEDNESDAY NIGHT AND THURSDAY BUT LINGER JUST OFFSHORE INTO FRIDAY. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 1030 PM MONDAY...MOST OF THE FORECAST IS IN GOOD SHAPE. MADE ADJUSTMENTS TO SHOW CURRENT TRENDS WITH T/TD AND POPS. THE LATEST SFC ANALYSIS IS SHOWING THE COLD FRONT OVER THE WESTERN PART OF NC. ALL THE SHOWERS/THUNDERSTORMS WE HAD THIS EVENING HAVE DIMINISHED OVER THE COASTAL PLAINS. LATEST 3KM HRRR SHOWS NO PRECIP FOR MOST OF THE OVERNIGHT...THEREFORE HAVE DELETED POPS. HI-RES MODEL INTRODUCES SHOWERS AGAIN AROUND 10Z AND ADDED SLIGHT CHANCE. EXPECT WIDESPREAD HIGH CLOUDINESS WILL HOLD MINIMUM TEMPERATURES IN THE 70S OVERNIGHT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... AS OF 220 PM MONDAY...SHORT WAVE ENERGY ROTATING AROUND STACKED LOW OVER NORTHERN GREAT LAKES WILL BEGIN TO CARVE OUT AN EASTERN TROF ON TUESDAY. THE BETTER UPPER SUPPORT WITH A WEAK SFC BNDRY LINGERING OVER THE AREA WILL HELP CONVECTIVE DEVELOPMENT WITH THE CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS INCREASING WITH DIURNAL HEATING, ESPECIALLY OVER INLAND AREAS ATTENDANT THE STALLING SFC FRONT. SEVERE TSTORM CHANCES APPEAR LIMITED GIVEN MARGINAL INSTABILITY AND WIND SHEAR, BUT A FEW HEAVIER DOWNPOURS CUD DEVELOP PER INCREASING PRECIPITABLE WATER. CLOUDS/PRECIP WILL RETARD TEMPERATURE RISES BUT A FEW 90 DEGREE READINGS POSSIBLE INLAND IF ANY PROLONGED SUNNY BREAKS DEVELOP. OTHERWISE MAINLY UPPER 80S INLAND WITH MID 80S COAST. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... AS OF 340 PM MONDAY...AN UPPER LOW NORTH OF THE GREAT LAKES WILL SHIFT EAST INTO WESTERN QUEBEC TUESDAY NIGHT INTO WEDNESDAY, ALLOWING THE UPPER TROUGH AXIS TO SHIFT EAST INTO NC BY THURSDAY THOUGH DEAMPLIFYING AS IT CROSSES THE CAROLINAS LATE THURSDAY INTO THURSDAY NIGHT. AT THE SURFACE, A WEAK FRONT WILL CROSS THROUGH EASTERN NC LATE TUESDAY NIGHT/EARLY WEDNESDAY MORNING THEN STALL OFF THE COAST LATE WEDNESDAY THROUGH FRIDAY. MAINTAINED CHANCE POPS TUESDAY NIGHT WITH FRONTAL PASSAGE, THEN SLIGHT CHANCE TO CHANCE POPS WEDNESDAY WHEN MODEST MOISTURE AND INSTABILITY SHOULD YIELD ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS ACROSS EASTERN NC. CONTINUED SLIGHT CHANCE POPS INLAND WITH CHANCE POPS ALONG THE COAST WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE BOUNDARY REMAINS STALLED OFFSHORE, WITH LIGHT NORTHEAST WIND LIKELY ADVECTING MOISTURE ACROSS THE REGION. THE SURFACE HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO SATURDAY. AN UPPER RIDGE SOUTH OF BERMUDA WILL BUILD WEST TOWARDS THE SOUTHEASTERN COAST SATURDAY THROUGH EARLY NEXT WEEK, WITH GUIDANCE NOT INDICATING ANY SIGNIFICANT SHORTWAVES CROSSING THE REGION FOR THE FAR EXTENDED PERIOD. ONLY A SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS FRIDAY AFTERNOON, THEN MOISTURE BECOMES LIMITED TO THE FAR EASTERN PORTIONS OF EASTERN NC/COAST. HEDGED CLOSER TO DIURNAL CONVECTIVE SCENARIO FOR SUNDAY/MONDAY AFTERNOONS, WITH MOSTLY DRY CONDITIONS FOR INLAND LOCATIONS EACH NIGHT. CONTINUED LACK OF AGREEMENT IN LONG RANGE GUIDANCE BASED ON THE LATEST 12Z RUN. TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... SHORT TERM /THROUGH 00Z WEDNESDAY/...VFR CONDITIONS SHOULD PREVAIL AGAIN OVERNIGHT. SOME BRIEF MVFR EXPECTED AT KPGV AND KISO WHICH PICKED UP SOME RAIN THIS AFTERNOON AND EVENING. VFR CONDITIONS OUTSIDE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY AND HAVE INCLUDED A VICINITY THUNDER AT ALL OF THE TAF SITES. LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 340 PM MON...SCATTERED CONVECTION POSSIBLE FOR ALL TERMINALS WITH ASSOCIATED SUB-VFR CIGS/VSBYS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A WEAK COLD FRONT WILL SHIFT THROUGH THE REGION TUESDAY NIGHT INTO WEDNESDAY, THEN LINGER OFFSHORE THROUGH THURSDAY. PREDOMINANT VFR CONDITIONS EXPECTED THURSDAY NIGHT THROUGH SATURDAY. && .MARINE... SHORT TERM /THROUGH TUESDAY/... AS OF 1030 PM MONDAY...MINOR ADJUSTMENTS MADE TO WINDS AND SEAS FOR REFLECT CURRENT TRENDS. LATEST BUOY OBS ARE SHOWING S/SE 10 KNOTS OR LESS ACROSS ALL THE WATERS WITH SEAS 2 TO 3 FT. WINDS WILL VEER TO MORE S/SW LATE TONIGHT OR EARLY TUESDAY. A WEAK COLD FRONT WILL STALL OVER INLAND AREAS ON TUESDAY. A WEAK PRESSURE GRADIENT WILL PERSIST ALONG THE COAST ON TUESDAY WITH S/SW WINDS REMAINING 10 KT OR LESS. SEAS MAINLY 2 TO 3 FT IN LONG PERIOD SWELL THROUGH TUESDAY. LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 345 PM MON...A WEAK COLD FRONT WILL CROSS THE EASTERN NC COASTAL WATERS WEDNESDAY MORNING, THEN LINGER OFFSHORE THROUGH FRIDAY, PRODUCING NE WINDS 10 KT OR LESS THROUGH THURSDAY, THEN SOME 5-15 KT FRIDAY INTO FRIDAY NIGHT. HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY, SHIFTING WINDS MORE EASTERLY SATURDAY. SEAS WILL RANGE 1-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR THE OUTER CENTRAL WATERS FRIDAY THROUGH SATURDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...CTC/BM SHORT TERM...BTC LONG TERM...DAG AVIATION...CTC/DAG/LEP MARINE...BTC/CTC/DAG/BM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
731 PM EDT MON AUG 24 2015 .SYNOPSIS... HIGH PRESSURE WILL BE CENTERED OFF THE NORTH CAROLINA COAST TONIGHT. A WEAK COLD FRONT APPROACHES FROM THE WEST LATE TONIGHT THEN WILL STALL OVER THE AREA TUESDAY AND WEDNESDAY. THE FRONT WILL THEN SLOWLY MOVE OFF THE COAST WEDNESDAY NIGHT AND THURSDAY BUT LINGER JUST OFFSHORE INTO FRIDAY. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 715 PM MONDAY...BAND OF SHOWERS/THUNDERSTORMS GRADUALLY DIMINISHING OVER THE COASTAL PLAINS. LATEST 3KM HRRR SHOWS MOST ACTIVITY GONE BY 02Z OR SO. WILL CARRY A 30% POP WEST OF HIGHWAY 17 UNTIL 02Z THEN LITTLE POP UNTIL LATE TONIGHT GIVEN WEAK FORCING. WIDESPREAD HIGH CLOUDINESS WILL HOLD MINIMUM TEMPERATURES IN THE 70S OVERNIGHT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... AS OF 220 PM MONDAY...SHORT WAVE ENERGY ROTATING AROUND STACKED LOW OVER NORTHERN GREAT LAKES WILL BEGIN TO CARVE OUT AN EASTERN TROF ON TUESDAY. THE BETTER UPPER SUPPORT WITH A WEAK SFC BNDRY LINGERING OVER THE AREA WILL HELP CONVECTIVE DEVELOPMENT WITH THE CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS INCREASING WITH DIURNAL HEATING, ESPECIALLY OVER INLAND AREAS ATTENDANT THE STALLING SFC FRONT. SEVERE TSTORM CHANCES APPEAR LIMITED GIVEN MARGINAL INSTABILITY AND WIND SHEAR, BUT A FEW HEAVIER DOWNPOURS CUD DEVELOP PER INCREASING PRECIPITABLE WATER. CLOUDS/PRECIP WILL RETARD TEMPERATURE RISES BUT A FEW 90 DEGREE READINGS POSSIBLE INLAND IF ANY PROLONGED SUNNY BREAKS DEVELOP. OTHERWISE MAINLY UPPER 80S INLAND WITH MID 80S COAST. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... AS OF 340 PM MONDAY...AN UPPER LOW NORTH OF THE GREAT LAKES WILL SHIFT EAST INTO WESTERN QUEBEC TUESDAY NIGHT INTO WEDNESDAY, ALLOWING THE UPPER TROUGH AXIS TO SHIFT EAST INTO NC BY THURSDAY THOUGH DEAMPLIFYING AS IT CROSSES THE CAROLINAS LATE THURSDAY INTO THURSDAY NIGHT. AT THE SURFACE, A WEAK FRONT WILL CROSS THROUGH EASTERN NC LATE TUESDAY NIGHT/EARLY WEDNESDAY MORNING THEN STALL OFF THE COAST LATE WEDNESDAY THROUGH FRIDAY. MAINTAINED CHANCE POPS TUESDAY NIGHT WITH FRONTAL PASSAGE, THEN SLIGHT CHANCE TO CHANCE POPS WEDNESDAY WHEN MODEST MOISTURE AND INSTABILITY SHOULD YIELD ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS ACROSS EASTERN NC. CONTINUED SLIGHT CHANCE POPS INLAND WITH CHANCE POPS ALONG THE COAST WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE BOUNDARY REMAINS STALLED OFFSHORE, WITH LIGHT NORTHEAST WIND LIKELY ADVECTING MOISTURE ACROSS THE REGION. THE SURFACE HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO SATURDAY. AN UPPER RIDGE SOUTH OF BERMUDA WILL BUILD WEST TOWARDS THE SOUTHEASTERN COAST SATURDAY THROUGH EARLY NEXT WEEK, WITH GUIDANCE NOT INDICATING ANY SIGNIFICANT SHORTWAVES CROSSING THE REGION FOR THE FAR EXTENDED PERIOD. ONLY A SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS FRIDAY AFTERNOON, THEN MOISTURE BECOMES LIMITED TO THE FAR EASTERN PORTIONS OF EASTERN NC/COAST. HEDGED CLOSER TO DIURNAL CONVECTIVE SCENARIO FOR SUNDAY/MONDAY AFTERNOONS, WITH MOSTLY DRY CONDITIONS FOR INLAND LOCATIONS EACH NIGHT. CONTINUED LACK OF AGREEMENT IN LONG RANGE GUIDANCE BASED ON THE LATEST 12Z RUN. TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... SHORT TERM /THROUGH 00Z WEDNESDAY/...VFR CONDITIONS SHOULD PREVAIL AGAIN OVERNIGHT. SOME BRIEF MVFR EXPECTED AT KPGV AND KISO WHICH PICKED UP SOME RAIN THIS AFTERNOON AND EVENING. VFR CONDITIONS OUTSIDE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY AND HAVE INCLUDED A VICINITY THUNDER AT ALL OF THE TAF SITES. LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 340 PM MON...SCATTERED CONVECTION POSSIBLE FOR ALL TERMINALS WITH ASSOCIATED SUB-VFR CIGS/VSBYS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A WEAK COLD FRONT WILL SHIFT THROUGH THE REGION TUESDAY NIGHT INTO WEDNESDAY, THEN LINGER OFFSHORE THROUGH THURSDAY. PREDOMINANT VFR CONDITIONS EXPECTED THURSDAY NIGHT THROUGH SATURDAY. && .MARINE... SHORT TERM /THROUGH TUESDAY/... AS OF 730 PM MONDAY...LIGHT SOUTHEAST WINDS ON ALL AREAS WATERS THIS EVENING AT LESS THAN 10 KNOTS WITH SEAS 2 TO 3 FEET. THE WINDS WILL VEER TO MORE S/SW LATE TONIGHT OR EARLY TUESDAY. A WEAK COLD FRONT WILL STALL OVER INLAND AREAS ON TUESDAY. A WEAK PRESSURE GRADIENT WILL PERSIST ALONG THE COAST ON TUESDAY WITH S/SW WINDS REMAINING 10 KT OR LESS. SEAS MAINLY 2 TO 3 FT IN LONG PERIOD SWELL THROUGH TUESDAY. LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 345 PM MON...A WEAK COLD FRONT WILL CROSS THE EASTERN NC COASTAL WATERS WEDNESDAY MORNING, THEN LINGER OFFSHORE THROUGH FRIDAY, PRODUCING NE WINDS 10 KT OR LESS THROUGH THURSDAY, THEN SOME 5-15 KT FRIDAY INTO FRIDAY NIGHT. HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY, SHIFTING WINDS MORE EASTERLY SATURDAY. SEAS WILL RANGE 1-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR THE OUTER CENTRAL WATERS FRIDAY THROUGH SATURDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...CTC SHORT TERM...BTC LONG TERM...DAG AVIATION...CTC/DAG/LEP MARINE...BTC/CTC/DAG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
119 AM CDT SUN AUG 23 2015 .UPDATE... ISSUED AT 119 AM CDT SUN AUG 23 2015 WINDS CONTINUE TO SLOWLY DIMINISH IN WESTERN PARTS OF THE STATE...WHILE THE STRONGER WINDS HAVE NOW REACHED AREAS FROM THE TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY. ALLOWED THE WIND HEADLINES TO EXPIRE IN MUCH OF THE WEST AND CENTRAL...BUT OPTED TO HOLD ONTO THE WIND ADVISORY INTO SUNDAY AFTERNOON IN OUR EAST. MOMENTUM TRANSFER FROM BUFR SOUNDINGS SUGGEST WINDS WILL CONTINUE AT ADVISORY LEVELS FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY INTO SUNDAY AFTERNOON. THERE COULD BE A BRIEF DECREASE IN WINDS TOWARDS SUNRISE...BUT WINDS SHOULD PICK UP AGAIN AS MIXING INCREASES. THIS LINES UP WELL WITH THE CURRENT HEADLINE IN PLACE FROM FGF. BLENDED IN CURRENT CONDITIONS AND RAN A TIME LAGGED ENSEMBLE OF THE HRRR FOR POPS. THIS CONTINUES A GRADUAL DECREASE IN PRECIPITATION CHANCES FROM WEST TO EAST EARLY THIS MORNING. UPDATE ISSUED AT 1008 PM CDT SAT AUG 22 2015 QUICK UPDATE TO EXPIRE THE WIND HAZARDS IN THE WEST. ALSO UPDATED POPS BASED ON LATEST RADAR TRENDS. UPDATE ISSUED AT 833 PM CDT SAT AUG 22 2015 CURRENTLY...UPPER LEVEL LOW IS SITUATED BETWEEN BISMARCK AND JAMESTOWN...WITH THE SURFACE LOW WELL TO THE EAST. STRONG PRESSURE RISES OVER WESTERN MINNESOTA BEHIND THE SURFACE FRONT...AND ALSO OVER NORTHWEST NORTH DAKOTA BEHIND THE UPPER LEVEL LOW. A SMALL AREA OF PRESSURE FALLS ASSOCIATED WITH THE UPPER LOW CURRENTLY RESIDE OVER SOUTH CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY. THINK ONCE THIS TRACKS OFF TO THE EAST...WE WILL STILL SEE SOME STRONG WINDS ACROSS CENTRAL NORTH DAKOTA LATE THIS EVENING. WILL THEY BE HWW CRITERIA? PROBABLY NOT WITH GUSTS BUT THINK WE COULD STILL SEE SOME SUSTAINED WINDS AROUND TO 40 MPH. CURRENT HWW FOR THE SOUTHWEST AND SOUTH CENTRAL EXPIRES AT 10 PM. THINK ITS SAFE TO LET THE HWW EXPIRE AT 10 ACROSS THE SOUTHWEST...THIS IS WHEN THE WIND ADVISORY ALSO EXPIRES IN THE NORTHWEST. COULD EXPIRE THE HWW IN THE SOUTH CENTRAL AND REPLACE IT WITH A WIND ADVISORY. BUT WHAT WE WILL DO IS EXTEND THE HWW IN THE SOUTH CENTRAL THROUGH 06Z (1 AM CDT). THINK THE POTENTIAL IS STILL THERE FOR SOME STRONG WINDS...PLUS THINK THIS WOULD CUT SOME OF THE CONFUSION OF EXPIRING ONE HAZARD AND ISSUING ANOTHER. FARTHER TO THE EAST...WILL ALSO EXTEND THE WIND ADVISORY IN THE EAST THROUGH 09Z (4 AM CDT). HAVE ADJUSTED POPS BASED ON LATEST ITERATIONS OF THE RAP/HRRR. THIS LINES UP WELL WITH CURRENT TRENDS. IT WOULD ALSO END PRECIPITATION IN THE TURTLE MOUNTAINS AND JAMES RIVER BASIN A FEW HOURS EARLIER THAN PREVIOUSLY FORECAST. ALL IN ALL...A WET AND WINDY FORECAST ACROSS CENTRAL NORTH DAKOTA. HOWEVER...THE RAIN HAS ENDED IN THE FAR WEST AND WINDS ARE STARTING TO DIMINISH. UPDATE ISSUED AT 644 PM CDT SAT AUG 22 2015 SURFACE LOW PRESSURE IN NORTHERN MINNESOTA WITH UPPER LEVEL LOW TRACKING THROUGH CENTRAL NORTH DAKOTA. MAIN UPDATE WAS TO ADJUST POPS BASED ON CURRENT RADAR AND EXTRAPOLATION. CURRENTLY A PRETTY LARGE DRY SLOT OVER CENTRAL AND EASTERN NORTH DAKOTA. HOWEVER...MOISTURE ASSOCIATED WITH THE UPPER LOW OVER WESTERN NORTH DAKOTA IS JUST MAKING ITS WAY TO THE HIGHWAY 83 CORRIDOR AND WILL CONTINUE TO TRACK EASTWARD THIS EVENING. WINDS REMAIN STRONG WITH THE TIGHT PRESSURE GRADIENT. THE UPPER LOW IS PRODUCING SOME PRESSURE FALLS OVER CENTRAL NORTH DAKOTA WHICH IS HINDERING THE STRONGER WINDS...BUT AS THE LOW MOVES EAST...ADDITIONAL PRESSURE RISES ARE POISED TO MOVE INTO CENTRAL NORTH DAKOTA. THUS EXPECT WINDS TO REMAIN STRONG OR EVEN PICK UP ACROSS CENTRAL NORTH DAKOTA THIS EVENING. NO CHANGES TO THE CURRENT HAZARDS. PNS WAS SENT EARLIER WITH HIGHEST GUSTS THROUGH 5 PM CDT. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 333 PM CDT SAT AUG 22 2015 WILL UPGRADE THE WIND ADVISORY TO A HIGH WIND WARNING SOUTH CENTRAL FOR THE REST OF THE AFTERNOON AND THIS EVENING. MODEL SOUNDINGS SHOW THE BEST MOMENTUM TRANSFER WILL BEGIN LATE THIS AFTERNOON AND THIS EVENING SOUTH CENTRAL. WITH THE DRY SLOT SHOWING UP IN SAT IMAGES FEEL THIS WILL BE REALIZED MAINLY EARL THIS EVENING SOUTH CENTRAL. OTHERWISE REMAINDER OF THE ADVISORY REMAINS IN EFFECT FOR THIS EVENING NORTH THROUGH THE EAST. ON SUNDAY...WINDS WILL BE GREATLY DIMINISHED AND SKIES WILL BE CLEARING. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 333 PM CDT SAT AUG 22 2015 THE STRONG LOW PRESSURE SYSTEM ASSOCIATED WITH THE WINDY AND SHOWERY DAY SATURDAY AND SATURDAY NIGHT...WITH WINDS CONTINUING SUNDAY...WILL BE EXITING THE REGION. THEN A WESTERN RIDGE BUILDS BRINGING SEASONABLE AUGUST WEATHER TO OUR AREA THROUGH THE UPCOMING WEEK. SUNDAY EVENING THE STRONG LOW PRESSURE SYSTEM IS FORECAST TO BE CENTERED OVER SOUTHWESTERN ONTARIO...WITH HIGH PRESSURE SETTLING OVER THE DAKOTAS THROUGH THE NIGHT. LIGHT WINDS AND CLEAR SKIES WILL ALLOW TEMPERATURES TO DROP INTO THE 40S ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA...WITH A FEW AREAS POSSIBLY DIPPING INTO THE UPPER 30S. THE BUILDING WESTERN RIDGE WILL BRING A WARMING TREND...WITH HIGHS MONDAY FROM 70 TO 80...TO 80 TO 90 BY THURSDAY. ON THURSDAY AND FRIDAY THERE IS A CHANCE OF THUNDERSTORMS WITH SOME UPPER LEVEL ENERGY IMPULSES MOVING THROUGH THE RIDGE ACROSS THE CENTRAL ROCKIES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 119 AM CDT SUN AUG 23 2015 CONDITIONS SHOULD CONTINUE TO IMPROVE FROM WEST TO EAST EARLY THIS SUNDAY MORNING. SHOWERS WITH REDUCED VISIBILITIES WILL CONTINUE AT KJMS FOR ANOTHER COUPLE HOURS...WITH VFR CONDITIONS THEN EXPECTED. WINDS SHOULD REMAIN GUSTY THROUGH SUNDAY AFTERNOON...BUT WILL DIMINISH SUNDAY EVENING. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ005-013-023- 025-036-037-047-048-050-051. && $$ UPDATE...CK SHORT TERM...WAA LONG TERM...JV AVIATION...CK
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
331 PM CDT SUN AUG 23 2015 .DISCUSSION... FRONTAL BOUNDARY IS CURRENTLY LOCATED OVER THE MO BOOTHEEL. THIS FEATURE IS MOVING OUR WAY AND THERE MAY BE JUST ENOUGH INSTABILITY IN PLACE TO ALLOW FOR REDEVELOPMENT OF SOME CONVECTIVE ACTIVITY LATE THIS AFTERNOON AND INTO THIS EVENING...BEST CHANCE ALONG THE PLATEAU. HRRR AND MODEL DATA BOTH CONCUR THAT SOME REDEVELOPMENT IS POSSIBLE. STORMS SHOULD REMAIN BELOW STRONG LIMITS HOWEVER. LATE TONIGHT...DRIER AIR WILL BEGIN WORKING IN. ENOUGH LOW LEVEL MOISTURE MAY REMAIN SO AS TO PRODUCE SOME PATCHY FOG LATE ACROSS THE PLATEAU AND SOUTH. GOING FORWARD...SFC HIGH WILL BUILD IN AND BRING WITH IT A DRY AIRMASS WITH BELOW NORMAL TEMPS. THERMAL TROUGHING WILL BE IN PLACE WITH 850 MB TEMPS HOLDING GENERALLY IN THE 11C-14C RANGE. SO...WE WILL SEE LOW TEMPERATURES IN THE 50S FOR MON NT AND TUES NT WITH HIGHS IN THE LOWER 80S WEST OF PLATEAU. HUMIDITY LEVELS WILL BE LOW WITH DEWPOINTS IN THE LOWER TO MID 50S. IN THE EXT FCST...THERMAL TROUGH WILL REMAIN IN PLACE THROUGH THURSDAY. SOUTHERLY RETURN FLOW NOT EXPECTED BEFORE FRIDAY SO WE WILL SEE A CONTINUATION OF DRY CONDITIONS AND BELOW NORMAL TEMPS. A WARMING TREND WILL COMMENCE BY SATURDAY AND SUNDAY AS UPPER RIDGING BEGINS TO RETURN WITH THE THERMAL TROUGHING LIFTING OUT. HIGH TEMPS BY SUNDAY WILL REACH BACK UP TOWARD THE UPPER 80S...WEST OF PLATEAU. WILL OPT TO INCLUDE LOW POPS FOR SUNDAY AS JUST ENOUGH RETURN MOISTURE LENDS A HAND TOWARD INCREASING OUR CAPE/CAP RATIOS. .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 68 84 57 80 / 20 0 0 0 CLARKSVILLE 62 82 54 80 / 20 0 0 0 CROSSVILLE 66 79 53 77 / 30 10 0 0 COLUMBIA 67 84 56 81 / 20 0 0 0 LAWRENCEBURG 68 83 58 80 / 20 0 0 0 WAVERLY 63 83 55 80 / 20 0 0 0 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
619 PM CDT MON AUG 24 2015 .AVIATION... /00Z TAFS/ A thunderstorm outflow boundary approaching KABI from the east will bring east wind gusts to 18 KTS 00Z to 1Z. Also added VCTS to KABI as a few storms may develop off the outflow boundary. Isolated to scattered thunderstorms possible again Tuesday afternoon...as a secondary weak cold front moves into the region. Will leave mention of storms out of terminals at this time, but coverage may become high enough for mention of VCTS. && .PREV DISCUSSION... /ISSUED 329 PM CDT MON AUG 24 2015/ SHORT TERM... (Tonight and Tuesday) A weak cold front is stalled generally along a line from near Barnhart...to Eldorado...to Brady. A cumulus field has developed this afternoon in the vicinity of the front. The HRRR continues to depict isolated to scattered shower and thunderstorm activity in the vicinity of the boundary this afternoon and early evening. Uncertainty remains on the extent of convection this afternoon, but slight chance PoPs were kept for much of the area, with the best chance across the southern two thirds of the area. Locally heavy rainfall will be possible, as very slow movement is expected. In addition, isolated downbursts will be possible. Most of the convection is expected to dissipate shortly after sunset, with the loss of daytime heating. Overnight lows will generally be in the 70s, although a few locations may drop into the upper 60s. Models continue to indicate an upper level disturbance moving across the area Tuesday in the north flow aloft. This in combination with what is left of the dissipating cold front will result in isolated to scattered showers and thunderstorms Tuesday afternoon, with the best chance across the eastern half of the region. Highs will generally be in the mid to upper 90s. Daniels LONG TERM... (Tuesday night through next Monday) The extended portion of the forecast will be mainly dry, and continued hot with temperatures averaging 5 or more degrees above normal through next weekend. Decided to keep slight chance PoPs going through Tuesday evening as a weak front continues to ease southward. The best chances by Tuesday evening should be generally south of a San Saba to Eldorado line where the front is expected to move to by the evening hours. Once again, if these storms develop, the main hazards will be gusty winds, and dangerous lightning. Have also kept very low end slight chance PoPs Wednesday afternoon and early evening as remnant outflow boundaries possibly left behind by Tuesday`s activity could result in isolated showers or storms Wednesday afternoon. From Thursday through the weekend, the upper level ridge over the southwestern U. S. will keep our weather hot and dry. Have nudged afternoon highs up a degree or two for the second half of the week as the ridge takes control, allowing the atmosphere to warm. Another cold front could possibly move into the area next weekend, but models show it struggling to make progress southward after reaching west central Texas, so will just trend temperatures downward a couple degrees next weekend into Monday for now. 20 && .PRELIMINARY POINT TEMPS/POPS... Abilene 72 95 72 97 / 10 20 10 5 San Angelo 72 98 71 100 / 20 20 10 10 Junction 71 97 70 98 / 20 30 20 20 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ 99/99/04
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
236 PM CDT SUN AUG 23 2015 .SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)... FOR THE REST OF THE AFTERNOON...MAY SEE A STRAY ISOLATED SHOWER OR THUNDERSTORM IN LAVACA AND/OR DEWITT COUNTIES THIS AFTERNOON. AMPLE INSTABILITY AND MOISTURE ARE PRESENT IN THE COASTAL PLAINS FOR ISOLATED HEAVY THUNDERSTORMS BUT ARE LACKING MUCH OTHER THAN HEATING TO GET PARCELS OFF THE SURFACE. NOT MUCH CAPPING IS CURRENTLY PRESENT BUT LOW TO MID LEVEL WARMING WAS ADVERTISED IN THE RAP SOUNDINGS SO THIS SHOULD STAY ISOLATED. ONLY MENTIONED SOME ISO THUNDER WITH SUB 20 PERCENT POPS IN THIS VICINITY AS A RESULT. ISOLATED ACTIVITY IN MEXICO AND IN THE BIG BEND AREA SHOULD STAY AWAY FROM THE CWA THIS AFTERNOON/EVENING. THE FRONTAL SYSTEM RESPONSIBLE IS PROGGED TO BEGIN KNOCKING ON THE DOORSTEP MONDAY MORNING AND SHOULD RESULT IN SOME CLOUD COVER AND SLIGHT CHANCE POPS FOR THE NORTHERN THIRD OF THE AREA MONDAY. NOTHING HAZARDOUS IS EXPECTED THOUGH. && .LONG TERM (TUESDAY THROUGH SUNDAY)... THE FOCUS OF THE LONG TERM IS ON THE PROSPECT FOR CHC POPS TUESDAY. A COLD FRONT WILL PUSH SOUTHWARD ACROSS THE MS RIVER VALLEY AND PROVIDE A SIMILAR PATTERN TO A FEW THIS SUMMER THAT HAVE RESULTED IN APPRECIABLE RAINFALL FOR THE CWA. AS THE COLD FRONT PROGRESSES WESTWARD INTO EAST TEXAS...MODELS ARE SHOWING VARYING AMOUNTS OF QPF GENERATION...MOSTLY DUE TO DISAGREEMENT IN AVAILABLE MOISTURE AND FRONTAL STRENGTH. THE MOST BULLISH MODEL AS FAR AS QPF GENERATION GOES IS THE ECMWF AS IT CAPTURES REMNANT MOISTURE UNDER THE RIDGE DUE TO THE FRONTAL SYSTEM CURRENTLY IN PLACE. THE GFS DOES NOT PRESCRIBE TO THIS AT ALL AND THE NAM GIVES AN EASTERN PREFERENCE WHERE MOISTURE IS MORE PLENTIFUL. HAVE FAVORED THE NAM DEPICTION THIS PACKAGE AND WPC QPF SEEMS TO AGREE. THEREFORE OPTED FOR THE CHC POPS TO MOSTLY ALONG AND EAST OF THE I35 CORRIDOR AND NORTH OF THE I10 CORRIDOR. MAY NEED SOME ADJUSTING FARTHER SOUTH OF THE COLD FRONT CAN PUSH A BIT FARTHER SOUTH...WHICH IS POSSIBLE GIVEN PREVIOUS SYSTEMS WE HAVE SEEN SO FAR. BEYOND THE TUESDAY TIME FRAME...UPPER LEVEL RIDGE PATTERN IS IN AGREEMENT IN BOTH EURO AND GFS MODELS. GFS ENSEMBLES SHOW IMPRESSIVE AGREEMENT FROM PERTURBATION TO PERTURBATION AS WELL FOR OVER 100 HOURS OUT. CONTINUE TO BE SKEPTICAL OF EURO ADVERTISEMENT OF QPF STRETCHING FROM THE GULF INTO THE CWA THROUGH WEDNESDAY. AN EAGLE EYE WILL ENSUE ON THE ECMWF ENTERING THE WEEK FOR POSSIBLE WEDNESDAY CHANGES TO THE POP FORECAST. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 76 99 77 100 75 / - 20 - 30 10 AUSTIN BERGSTROM INTL AIRPORT 74 99 75 99 73 / - 20 - 30 10 NEW BRAUNFELS MUNI AIRPORT 76 100 75 100 74 / - - - 20 - BURNET MUNI AIRPORT 76 97 75 98 73 / - 20 10 30 10 DEL RIO INTL AIRPORT 77 100 77 101 76 / - - 0 10 0 GEORGETOWN MUNI AIRPORT 76 99 76 99 74 / - 20 10 30 10 HONDO MUNI AIRPORT 73 99 74 99 73 / - - 0 10 - SAN MARCOS MUNI AIRPORT 76 99 76 99 74 / - - - 30 10 LA GRANGE - FAYETTE REGIONAL 77 99 76 99 74 / - - 10 30 10 SAN ANTONIO INTL AIRPORT 78 99 77 99 76 / - - - 20 - STINSON MUNI AIRPORT 76 100 76 100 76 / - - 0 20 - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...RUNYEN SYNOPTIC/GRIDS...TB3 PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
102 PM CDT SUN AUG 23 2015 .AVIATION... ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS THE SOUTH PLAINS OVER THE PAST HOUR WITH ACTIVITY EXPECTED TO CONTINUE IN THE VICINITY OF KPVW AND KLBB THROUGH THE LATE AFTERNOON. MVFR CIGS ARE EXPECTED TO ERODE BY MID AFTERNOON AT KPVW AND KCDS...WIND GUSTS UP TO 25-30 MPH CAN BE EXPECTED WITH ANY THUNDERSTORMS...WITH SUSTAINED WINDS OUT OF THE NORTHEAST AROUND 15 MPH AT ALL TERMINALS INTO THE EVENING. && .PREV DISCUSSION... /ISSUED 1209 PM CDT SUN AUG 23 2015/ UPDATE... A FEW SHOWERS AND T-STORMS ARE DEVELOPING ACROSS THE CENTRAL AND EASTERN SOUTH PLAINS TO THE NORTH OF THE COLD FRONT WHICH IS JUST EXITING OUR SRN ZONES. WE HAVE ADDED AN ISOLATED MENTION TO THE FORECAST THROUGH THE AFTERNOON FOR ROUGHLY THE SRN 2/3RDS OF THE FORECAST AREA. SOME BRIEF HEAVY DOWNPOURS WILL BE POSSIBLE UNDERNEATH THESE CELLS. PREV DISCUSSION... /ISSUED 402 AM CDT SUN AUG 23 2015/ SHORT TERM... CANADIAN FRONT AT 4 AM WAS MAKING STEADY PROGRESS SOUTH ACROSS THE SOUTHERN PANHANDLE AND AT ITS PRESENT MOTION OF 25-30 MPH SHOULD BE IN LUBBOCK BY SUNRISE. STRONGEST PRESSURE RISES WERE FOCUSING ACROSS THE WESTERN PANHANDLE WHERE EARLIER DALHART OBSERVED LOWER VISBYS AND BLOWING DUST FROM NORTHERLY GUSTS OVER 30 MPH. ASIDE FROM A FEW SCANT SHOWERS AND STORMS IN THE ENHANCED POST-FRONTAL UPSLOPE REGIME OF NERN NM...PRECIP CHANCES ARE SHAPING UP QUITE POOR GIVEN AN OVERALL ABSENCE OF PRE AND POST-FRONTAL CLOUDS. WORSE...REGIONAL VWP DATA SHOW THAT THE LLJ HAS VEERED SW /NOW PARALLEL TO THE FRONT/ WHICH IS FURTHER HURTING OPPORTUNITIES FOR DEEPER CONVERGENCE AND SATURATED ASCENT. IN LIGHT OF THESE UNFAVORABLE FACTORS...EARLIER CHANCE POPS WERE SHOWN THE DOOR. AN ERRANT SHOWER MAY STILL SNEAK INTO OUR NW ZONES FROM THE MORE FAVORABLE NELY UPSLOPE FLOW IN ERN NM...BUT ODDS ARE LOOKING QUITE LONG FOR MEASURABLE PRECIP THIS A.M. THE FRONT IS LIKELY TO STALL IN THE PERMIAN BASIN THIS AFTERNOON AS THE SURFACE HIGH HOLDS UP IN THE NRN PANHANDLE. ALTHOUGH NELY WINDS WILL ADVECT AN AXIS OF RICH POST-FRONTAL DEWPOINTS INTO OUR SERN COUNTIES FROM OKLAHOMA...MOST MODEL SOUNDINGS NORTH OF THE FRONT SHOW TOO MUCH CINH EVEN WITH WARMER TEMPS FROM A REDUCED COVERAGE OF CLOUDS. DID RETAIN A SLIVER OF LOW POPS IN OUR SOUTHERN ROW OF COUNTIES GIVEN THEIR PROXIMITY TO THE BOUNDARY... BUT EVEN THIS MAY BE TOO OPTIMISTIC. TONIGHT...SOME MODELS ARE EAGER TO CONVECT IN A SHALLOW AND WEAK ISENTROPIC REGIME...THOUGH THIS POSSIBILITY SEEMS OVERDONE GIVEN NO BACKGROUND ASSISTANCE AND AN EASTERLY LLJ TAKING AIM WELL TO OUR SW ALONG THE UPPER TRANS PECOS. A LINGERING SWATH OF MID-LEVEL MOISTURE EVIDENT ON WATER VAPOR ACROSS SRN NM SEEMS A MORE LIKELY LOCATION FOR POPS IN THE NEXT 24 HOURS...SO POPS TONIGHT WERE REMOVED OVER ALL BUT OUR FAR SW COUNTIES. ASIDE FROM NUDGING HIGH TEMPS UPWARD TODAY...NO MAJOR CHANGES TO TEMPS WERE NECESSARY. LONG TERM... CONCERNS ABOUT PRECIPITATION CHANCES CONTINUE INTO THE DAY MONDAY AS THE STALLED BOUNDARY STARTS TO MOVE NORTHWARD AS A WARM FRONT THROUGH THE DAY. AGAIN THERE IS A LACK OF ANY KIND OF SYNOPTIC SCALE FORCING TO AID IN LIFTING PARCELS THROUGH THE DAY. AS THE WARM FRONT MOVES ACROSS THE AREA...MODELS DO INCREASE MID-LEVEL MOISTURE SOME RESULTING IN AT LEAST A BIT OF ELEVATED INSTABILITY LATE IN THE AFTERNOON. WITH THE FRONT MOVING NORTHWARD THROUGH THE DAY...ANY LOW-LEVEL FOCUS FOR STORM DEVELOPMENT WILL GRADUALLY SHIFT NORTH AND EASTWARD AND HAVE DROPPED POPS AND ADJUSTED THEM TO FAVOR THE ROLLING PLAINS BY MONDAY EVENING WHERE DEEPER MOISTURE WILL RESIDE. THE NAM ALSO HOLDS THE FRONT UP ACROSS THE ROLLING PLAINS INTO TUESDAY MORNING WITH WEAK PRESSURE RISES BUT CONDITIONS WILL CONTINUE TO BECOME LESS AND LESS FAVORABLE THROUGH THE DAY AS THE RIDGE BUILDS BACK EASTWARD AND AS A STRENGTHENING UPPER- LEVEL JET DEVELOPS EAST OF THE FORECAST AREA INCREASING SUBSIDENCE ALOFT AT THE SAME TIME. FORECAST FOR THE MIDDLE PART OF THE WEEK IS SEASONABLY HOT AND DRY WITH THE RIDGE GRADUALLY BUILDING IN ALOFT...WITH HEIGHTS AT THEIR GREATEST ON TUESDAY AND WEDNESDAY. A SLIGHT SHIFT IN THE RIDGE TO THE WEST IS STILL EXPECTED FOR THE END OF THE WEEK WHICH WILL PLACE US IN NORTHWEST FLOW ALOFT. THERE ARE STILL INDICATIONS OF A COUPLE OF SHORTWAVES MOVING SOUTHEAST ACROSS THE REGION FOR THURSDAY NIGHT AND FRIDAY NIGHT WHICH COULD BRING A RETURN OF SLIGHT CHANCE POPS BOTH THOSE DAYS ALONG WITH SLIGHTLY COOLER HIGH TEMPERATURES. THE PROSPECTS FOR ANOTHER COOL FRONT FOR THE END OF THE WEEK DO NOT LOOK QUITE AS GOOD AS THE GFS HAS BACKED OFF ON THIS POSSIBILITY WHILE THE ECMWF HINTS AT A VERY WEAK BOUNDARY ARRIVING SATURDAY. JORDAN LUB WATCHES/WARNINGS/ADVISORIES... NONE. $$ && .PRELIMINARY POINT TEMPS/POPS... FRIONA 58 86 62 91 / 10 20 10 10 TULIA 60 85 63 90 / 10 20 20 20 PLAINVIEW 60 85 64 91 / 10 20 10 20 LEVELLAND 63 86 65 91 / 10 20 10 10 LUBBOCK 63 87 66 92 / 10 20 10 20 DENVER CITY 65 87 65 91 / 20 20 10 10 BROWNFIELD 65 87 67 91 / 10 20 10 10 CHILDRESS 67 87 67 93 / 10 20 20 20 SPUR 67 88 67 94 / 10 20 20 20 ASPERMONT 71 92 71 96 / 10 20 20 20 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
Area Forecast Discussion National Weather Service Midland/Odessa TX 1255 PM CDT SUN AUG 23 2015 .DISCUSSION... Please see the 23/18Z forecast discussion below. && .AVIATION... VFR conditions will for the most part prevail across all area terminals through 24/18Z. A quasi-stationary cold front (presently extending from about 20 S KGDP - KINK - Lamesa) will serve as the focus for scattered TSRA this afternoon, with coverage extending into the evening as moist upglide commences above this front after sunset. As such, have gone pessimistic at KCNM, KHOB, and KINK where TEMPOs are warranted. MVFR visibility in TSRA and wind gusts to 40 kts are possible at these locales. Storms are firing over the Davis Mountains and may eventually impact KFST during the late afternoon hours, with similar MVFR visibility and wind gusts to 40 kts (maybe more here, depending on how much heating occurs over the Pecos River valley). At this time we don`t see a strong enough signal at KPEQ to introduce TEMPO TSRA here, but will monitor. Less of a chance at KMAF, although a few of the past HRRR runs indicate some spotty -SHRA/TSRA in the late afternoon/evening hours over the Permian Basin. Bears watch. Conditions will gradually improve around midnight local time, with a lot of convective debris overhead. There are indications that moist upslope on the east side of the Guadalupes/Delawares will produce MVFR to IFR conditions toward daybreak Monday. Have kept VFR conditions at KCNM and KPEQ and will await further data. && .PREV DISCUSSION... /issued 626 AM CDT SUN AUG 23 2015/ DISCUSSION... See 12z aviation discussion below. AVIATION... VFR conditions are expected for the next 24 hours. Showers and thunderstorms are possible this afternoon across the area especially for CNM and HOB. Light and variable winds will come around to the north beginning this morning as a cold front moves into the area around 15z. The strongest winds appear to be at CNM and winds are expected to shift to the east this afternoon. Winds will likely be variable with some gusts. PREV DISCUSSION... /issued 415 AM CDT SUN AUG 23 2015/ DISCUSSION... WV imagery shows an upper-lvl ridge extending across the srn CONUS, from SoCal to the Florida. To the north, a trough was ejecting into nrn MN. Closer to home, sfc obs and area radars show a cold front moving thru the Texas Panhandle, trailing the trough. This feature looks much weaker/shallower than last week`s front, w/only modest pressure rises along the front. Models differ somewhat on how far it makes it into the FA, w/the NAM bringing it into mid-CWA, whereas the GFS and ECMWF stall it a little further north. Going w/the NAM, it looks as though the front will stall diurnally this afternoon, before retreating north just a little overnight as a 25-30kt LLJ develops. This will be the main focus for convection, w/best chances over SE NM along the front this afternoon. If the GFS pans out, SE NM could see significant rainfall. Otherwise, thicknesses should bottom out Monday, but temps will remain above-normal Monday afternoon before the ridge intensifies over the SW CONUS later in the week, pushing temps once more into the upper 90s most locations. Unfortunately, models keep the theta- e ridge to the west, affording little chances of rain in the extended. MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. $$ && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 70
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1137 PM CDT SAT AUG 22 2015 .AVIATION... /06Z TAFS/ CONCERNS: NONE. HAVE REMOVED MVFR CIGS AT WACO AFTER 12Z SUNDAY AS IT APPEARS BOUNDARY LAYER FLOW IS TOO WEAK AND LAYER IS TOO DRY FOR STRATUS IN THE MORNING. OTHERWISE...VFR WITH S-SE FLOW 10-15 KTS THROUGHOUT. AS FOR POSSIBLE WEAK COLD FROPA...MODELS DISAGREE QUITE A BIT WITH THE GFS WAY FASTER THAN THE ECMWF OR NAM MOS GUIDANCE. BEING THERE THE FRONT WILL LOST UPPER SUPPORT AND STRONG AUGUST HEATING...HAVE OPTED FOR THE LATTER TWO GUIDANCES WHICH IS WELL BEYOND THE 30 HR PERIOD FOR DFW. CONVECTIVE CHANCES 24 HOURS WILL BE TOO ISOLATED AND SHOULD REMAIN CLOSER TO THE RED RIVER VALLEY FOR ANY MENTION AT DFW AIRPORTS. 05/ && .UPDATE... THE OUTFLOW BOUNDARY ALONG THE EASTERN RED RIVER COUNTIES HAS DISSIPATED AND WINDS HAVE RETURNED TO THE SOUTH. ALL HI-RES MODELS DO NOT SHOW ANY CONVECTION IN THE CWA OVERNIGHT AND HAVE REMOVED POPS AREA WIDE. TTU WRF AND HRRR MODELS DO NOT BRING THE FRONT SOUTH OF THE RED RIVER UNTIL LATE SUNDAY AFTERNOON. THUS WE HAVE LOWERED POPS TO 20 PERCENT SUNDAY MORNING ALONG THE RED RIVER VALLEY...AND 20-30 PERCENT SUNDAY AFTERNOON ALONG AND NORTH OF I-20. THE MOST FAVORED AREA FOR CONVECTION SUNDAY AFTERNOON AND EVENING SHOULD BE THOSE COUNTIES EAST OF A GAINESVILLE TO DENTON LINE. 75 && .PREV DISCUSSION... /ISSUED 324 PM CDT SAT AUG 22 2015/ A COMPLEX OF THUNDERSTORMS ASSOCIATED WITH A SHORT WAVE WILL CONTINUE MOVING ACROSS EXTREME EASTERN OKLAHOMA AND ARKANSAS THIS AFTERNOON. SOME OF THESE STORMS WILL MOVE SOUTHEAST OF THE MAIN COMPLEX ON AN OUTFLOW BOUNDARY AND AFFECT THE NORTHEAST ZONES THROUGH LATE AFTERNOON. A FEW SHOWERS AND THUNDERSTORMS ARE ALSO POSSIBLE ACROSS THE SOUTHEAST ZONES OF NORTH TEXAS THROUGH SUNSET WHERE MOISTURE AND INSTABILITY ARE THE MOST ABUNDANT. THIS ACTIVITY SHOULD DISSIPATE WITH THE LOSS OF SURFACE HEATING. AFTER SUNSET...A QUIET...WARM AND HUMID NIGHT IS STORE WITH OVERNIGHT LOWS FROM THE MID 70S TO AROUND 80. A COLD FRONT WILL MOVE ACROSS THE CENTRAL PLAINS OVERNIGHT AND SUNDAY MORNING AND REACH THE RED RIVER AROUND MIDDAY. WEAK FORCING FOR ASCENT MAY RESULT IN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE NORTHERN HALF OF NORTH TEXAS SUNDAY AFTERNOON/SUNDAY NIGHT. HOWEVER...WEAK LARGE SCALE SUBSIDENCE MAY LIMIT OR EVEN PREVENT STORMS FROM FORMING. THEREFORE...WE WILL KEEP ONLY 20 TO 30 PERCENT POPS IN THE FORECAST. THE COLD FRONT WILL MOVE SLOWLY THROUGH NORTH TEXAS MONDAY THROUGH TUESDAY AND WILL WARRANT THE MENTION OF SOME LOW POPS. THE FRONT WILL ALSO BRING A FEW MORE CLOUDS BUT ONLY SLIGHTLY COOLER TEMPERATURES. UPPER LEVEL HIGH PRESSURE WILL REMAIN CENTERED OVER ARIZONA AND NEW MEXICO WEDNESDAY THROUGH THE WEEKEND WHICH WILL KEEP NORTH TEXAS IN DRY NORTH TO NORTHWEST FLOW ALOFT. THE EXTENDED MODELS HAVE BEEN ADVERTISING A WEAK SHORT WAVE ON THE NORTHEASTERN PERIPHERY OF THE UPPER RIDGE APPROACHING THE RED RIVER ON FRIDAY. HOWEVER...MOISTURE SHOULD BE VERY LIMITED WHEN THE SHORT WAVE ARRIVES AND PRECIPITATION SEEMS UNLIKELY AT THIS TIME. SEASONABLY WARM TEMPERATURES ARE EXPECTED WEDNESDAY THROUGH THE WEEKEND WITH HIGHS IN THE LOWER AND MIDDLE 90S AND LOWS IN THE 70S. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 79 98 75 95 74 / 5 20 20 20 20 WACO, TX 78 99 77 99 74 / 5 5 5 20 20 PARIS, TX 74 95 72 91 69 / 10 30 40 20 20 DENTON, TX 78 97 70 92 71 / 5 20 30 20 20 MCKINNEY, TX 77 97 73 93 69 / 5 30 30 20 20 DALLAS, TX 80 99 77 96 76 / 5 20 20 20 20 TERRELL, TX 78 99 73 97 71 / 5 20 20 20 20 CORSICANA, TX 78 98 76 99 75 / 5 10 10 20 20 TEMPLE, TX 76 98 76 99 75 / 0 5 5 20 10 MINERAL WELLS, TX 74 99 71 94 70 / 5 10 20 20 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 05/75
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1133 PM CDT SAT AUG 22 2015 .AVIATION... /06Z TAFS/ Low to mid 70s dew points in the Hill Country were advecting northward toward the I-10 corridor at 5Z, and expect to see stratus with MVFR ceilings at KSOA and KJCT for 2-3 hours after sunrise. An isolated shower or thunderstorm possible a weak cold front approaches KABI late Sunday evening, but the best potential will be Monday. Will not include VCTS at KABI due to sparse thunderstorm coverage. && .PREV DISCUSSION... /ISSUED 641 PM CDT SAT AUG 22 2015/ AVIATION... /00Z TAFS/ MVFR stratus likely along the I-20 corridor, affecting KSOA and KJCT late tonight through mid morning Sunday. Otherwise VFR with southeast to south winds 12 KTs or less. PREV DISCUSSION... /ISSUED 318 PM CDT SAT AUG 22 2015/ SHORT TERM... (Tonight and Sunday) A few diurnal thunderstorms have developed over the Davis Mountains this afternoon with only sparse cu field and a few high clouds over West Central TX. Temperatures have warmed into the mid/upper 90s with dewpoints holding in the low/mid 60s. Generally quiet weather conditions are expected tonight across the area with the cu field dissipating with the setting sun. The HRRR has been insistent on developing some convection west of San Angelo late this afternoon, but this solution has been dismissed as an outlier, especially given the lack of a focused cu field this afternoon. Tonight, expect temperatures to drop into the mid 70s with southerly winds remaining in the 6-12 mph range. Winds could become gusty for a few hours tonight, especially in the higher terrain as the low-level jet sets up. A weak cold front will move south into the Big Country on Sunday. The general consensus is that this front will move as far south as a Sterling City to Eastland line by early afternoon, likely stalling out for the remainder of the day. Temperatures are expected to be a few degrees cooler (low/mid 90s) behind this boundary, with highs likely in the mid/upper 90s to the south. Scattered showers and thunderstorms are expected to develop during the afternoon in the vicinity of this cold front. While organized severe weather is not anticipated, high cloud bases will yield a potential microburst environment. Johnson LONG TERM... (Sunday night through Saturday) A weak cold front will be located across the Big Country Sunday evening, then slowly move south. Along and behind the front, isolated to scattered showers will be possible, with the best chance north of Interstate 20. The front will slowly progress south reaching the Concho Valley/Heartland Monday morning. The front will serve as the focus for additional isolated showers and thunderstorms on Monday, mainly north of a Mertzon, to Menard, to Mason line. Much of the rest of the extended forecast will be characterized by an upper level ridge centered over the Desert Southwest, with West Central Texas in northwest to north flow aloft. The forecast generally looks to remain dry, but given the northerly flow aloft, any embedded upper level shortwave troughs (disturbances) could result in at least isolated convection for portions of the area. The first opportunity for showers and thunderstorms will be Tuesday as disturbance in the northwest flow aloft traverses the area. This is depicted most aggressively by the ECMWF, with the best PoPs across the eastern half of the area. The next opportunity for rainfall will be Friday into next weekend, as another cold front approaches the area. The best PoPs look to be across the Big Country at this time. In conclusion, the timing and strength of any disturbances is hard to pinpoint this far in advance, but the overall theme for the upcoming week is for dry conditions to persist. Temperatures through much of the upcoming work week will be above normal. Highs will generally be in the mid to upper 90s, although a few locations may approach the century mark, especially during the first part of the week. Overnight lows will generally be in the 70s, with a few locations dropping into the upper 60s. Daniels && .PRELIMINARY POINT TEMPS/POPS... Abilene 76 97 73 94 / 5 20 30 20 San Angelo 76 101 74 98 / 5 10 10 20 Junction 75 99 74 98 / 5 5 5 10 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ 99/99/04
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
947 PM EDT MON AUG 24 2015 .SYNOPSIS... HIGH PRESSURE WILL START MOVING INTO THE AREA TONIGHT BEHIND AN EXITING COLD FRONT. HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR WEATHER PATTERN WITH DRIER AIR THROUGH AT LEAST THURSDAY. && .NEAR TERM /THROUGH TUESDAY/... AS OF 945 PM EDT MONDAY... ISOLATED SHOWERS WILL STILL BE POSSIBLE THROUGH MIDNIGHT ACROSS PARTS OF SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH CAROLINA. LITTLE CHANGE IS BEING MADE TO THE OVERALL FORECAST. MINOR ADJUSTMENTS WERE MADE TO THE TEMPERATURE AND DEW POINT TRENDS THROUGH MIDNIGHT BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS OF COOLING AND DRYING AIR. AS OF 630 PM EDT MONDAY... KFCX 88D RADAR WAS DETECTING ISOLATED SHOWERS...AND EVEN MORE ISOLATED...THUNDERSTORMS ACROSS PARTS OF SOUTHSIDE VIRGINIA. THIS ACTIVITY WAS LOCATED ALONG AND EAST OF A COLD FRONT THAT IS MOVING THROUGH THE AREA...CURRENTLY NEAR A MARTINSVILLE TO LYNCHBURG LINE. THE CONVECTION WILL CONTINUE MAKING PROGRESS EASTWARD INTO THE EVENING HOURS...AND EXIT THE REGION BETWEEN 1000 PM AND 1100 PM. HAVE MADE MINOR ADJUSTMENTS TO THE FORECAST CHANCE OF PRECIPITATION FOR THE NEXT COUPLE OF HOURS. HAVE FOCUSED ON PUTTING HIGHER POPS IMMEDIATELY DOWNSTREAM OF THE CURRENT ACTIVITY WHERE CONFIDENCE IN A CONTINUATION OF THE PRECIPITATION IS HIGHEST. AS OF 310 PM EDT MONDAY... SURFACE COLD FRONT IN THE WESTERN MOUNTAINS THIS AFTERNOON WILL TRAVEL EAST THIS EVENING INTO TONIGHT. PRE-FRONTAL TROUGH IN THE PIEDMONT TRIGGERING SCATTERED CONVECTION IN THE MOIST UNSTABLE AIR. SPC MESOSCALE ANALYSIS AT 18Z INDICATED SFC BASED CAPES FROM 1 TO 2K J/KG EAST OF THE BLUE RIDGE MOUNTAINS. THE DEEP LAYER MOISTURE FLUX CONVERGENCE WAS ENHANCED JUST EAST OF BLUE RIDGE MOUNTAINS. THE DAY ONE CONVECTIVE OUTLOOK KEEPS OUR AREA IN GENERAL THUNDERSTORMS. THE BETTER THREAT FOR STRONGER AND MORE ORGANIZED CONVECTION REMAINS TO OUR NORTH WITH THE BETTER DYNAMICS. AN ISOLATED PULSE STRONG THUNDERSTORM MAY BE POSSIBLE IN THE EAST...BUT GIVEN MARGINAL INSTABILITY...LACK OF ROBUST UPDRAFTS AND WEST FLOW...SEVERE WEATHER IS NOT EXPECTED. DEEP LAYER SHEAR WILL REMAIN INSUFFICIENT FOR SEVERE CONVECTIVE ORGANIZATION. LEANED POPS TOWARDS HRRR FOR THIS AFTERNOON INTO THIS EVENING...THEN BLENDED ISC GRIDS TOWARDS SUPERBLEND FOR TONIGHT INTO TUESDAY. THE COLD FRONT WILL SLOW AND STALL TO OUR EAST ALONG THE COASTAL PLAIN TONIGHT INTO TUESDAY...AS A WAVE OF LOW PRESSURE LIFTS NORTHWARD ALONG THE BOUNDARY. HIGH PRESSURE WILL BUILD EAST INTO OUR REGION TONIGHT INTO TUESDAY. DRIER AIR WILL LAG A FEW HOURS AS USUAL BEHIND THE MAIN FRONT...BUT SHARP DEWPOINT DROPS NOTED IN THE OHIO VALLEY. SHAPED LOW TEMPERATURES IN THE WESTERN MOUNTAINS TO COOLER COOP MOS VALUES. IT SHOULD BE A GOOD NIGHT TO OPEN THE WINDOWS WITH LOW TEMPERATURES FROM THE UPPER 40S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT CLOSER TO FRONTAL BOUNDARY. ALOFT THE UPPER PATTERN CONTINUES WITH AN EASTERN TROF AND GREAT LAKES CLOSED LOW SLOWING TRAVELING EAST TUESDAY. UNDER PLENTY OF SUNSHINE...HIGH TEMPERATURES WILL BE BELOW NORMAL WITH READINGS FROM THE UPPER 60S IN THE NORTHWEST MOUNTAINS TO THE MID 80S IN THE PIEDMONT. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 230 PM EDT MONDAY... LARGE LONGWAVE UPPER TROUGH FOR LATE AUGUST WILL BE SLIDING EAST ACROSS THE REGION DURING THE WEEK ALLOWING COOL SURFACE HIGH PRESSURE TO BUILD INTO AND NORTH OF THE AREA BY THURSDAY. THIS SHOULD KEEP OVERALL SUBSIDENCE IN PLACE PER DEEPER MOISTURE TO THE EAST ALONG THE RESIDUAL FRONT...WITH LOW LEVEL DRY AIR SUPPORTIVE OF COOL NIGHTS AND MOSTLY SUNNY DAYS THROUGH THE PERIOD. HOWEVER MID LEVEL SHORTWAVE ENERGY ROTATING THROUGH THE 5H TROUGH WILL HAVE TO BE WATCHED FOR POSSIBLE INTERACTION WITH MOISTURE TO THE EAST ESPECIALLY LATE IN THE PERIOD...AND EARLY ON FOR MORE UPSLOPE INDUCED CLOUDS WEST EARLY WEDNESDAY. GIVEN THAT LATEST FORECAST SOUNDINGS CONTINUE TO SHOW PLENTY OF LOW LEVEL DRY AIR IN PLACE WILL ONLY BOOST CLOUDS A BIT AND LEAVE OUT POPS FOR NOW. OTHERWISE TEMPS THE MAIN CONCERN GIVEN THE ARRIVAL OF THE COOLEST AIR ALOFT WEDNESDAY MORNING...AND SUBSEQUENT REINFORCING POCKETS OF 85H COOL ADVECTION INTO THURSDAY. HOWEVER TIMING OF SHORTWAVE ENERGY EARLY WEDNESDAY SUGGESTS PERHAPS MORE UPSLOPE CLOUDS FAR WEST AND SOME MIXING OUTSIDE OF THE VALLEYS GIVEN THE SURFACE HIGH STILL WELL UPSTREAM. THUS BUMPED UP LOWS A CATEGORY OR SO WEDNESDAY MORNING WITH ONLY THE DEEPEST VALLEYS SEEING A FEW 40S AND MAINLY 50S ELSEWHERE. NOT QUITE AS COOL THURSDAY MORNING BUT STILL 50S WEST TO LOW 60S EAST GIVEN A SLIGHT REBOUND IN DEWPOINTS OUT EAST. EXPECT HIGHS TO RECOVER TO JUST BELOW SEASONAL LEVELS PENDING HEATING OF DRY AIR SO TRENDED CLOSER TO THE LATEST MOS BLEND FOR HIGHS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 1245 PM EDT MONDAY... UPPER TROUGH WILL BE LIFTING OUT ACROSS THE REGION LATE IN THE WEEK RESULTING IN BRIEF ZONAL 5H FLOW BEFORE ANOTHER WEAKER SHORTWAVE TROUGH DROPS SE AROUND THE UPPER RIDGE TO THE WEST AND INTO THE AREA EARLY NEXT WEEK. THIS SHOULD ALLOW A RATHER LARGE AREA OF HIGH PRESSURE TO THE NORTH LATE IN THE WEEK TO SETTLE SOUTH AND OVERHEAD DURING THE WEEKEND BEFORE WEAKENING INTO NEXT WEEK. MOST MODELS DEPICT THIS SCENARIO IN KEEPING DEEPER MOISTURE WITH THE OLD FRONT NEAR THE COAST WITH PERHAPS THE REMNANT WAVE OF DANNY SPAWNING A WEAK LOW OFF THE SOUTHEAST COAST EARLY NEXT WEEK. HOWEVER GUIDANCE ALSO INDICATES JUST ENOUGH TROPICAL MOISTURE RETURN BY DAYS 6/7 UNDER THE WEAKENING SURFACE RIDGE AND SLIGHT COOLING ALOFT TO BRING A RETURN OF LEAST SOME DIURNAL ISOLATED/SCATTERED MAINLY MOUNTAIN CONVECTION FROM LATE SATURDAY INTO MONDAY. OTRW SHOULD BE MAINLY DRY WITH SEASONAL TEMPS EARLY IN THE PERIOD...THEN A REBOUND TOWARD HOTTER AND MORE HUMID CONDITIONS BY EARLY NEXT WEEK...WITH HIGHS 80S TO PERHAPS NEAR 90 SOUTHEAST AS RETURN FLOW DEVELOPS. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... AS OF 730 PM EDT MONDAY... GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF VALID PERIOD. A DRY AIR MASS WILL SPREAD EASTWARD ACROSS THE REGION OVERNIGHT...WITH THE LAST VESTIGES OF THE HIGHER DEWPOINT/RH VALUES ACROSS THE PIEDMONT BEING PUSHED FURTHER EAST TOWARD THE COAST BY TUESDAY. ISOLATED SHRA/TSRA ASSOCIATED WITH THE PRE- FRONTAL TROUGH ACROSS THE PIEDMONT WILL DISSIPATE QUICKLY WITHIN THE NEXT HOUR. OTHERWISE...EXPECTING MOSTLY SKC/SCT250 OVERNIGHT...THEN SKC EAST TO FEW STRATOCUMULUS WEST IN THE 050-060 RANGE TUESDAY AFTERNOON. ONLY POSSIBILITY OF MARRING AN OTHERWISE VFR FORECAST THROUGH THE TAF VALID PERIOD IS PATCHY RADIATIONAL FOG LATE TONIGHT/EARLY TUESDAY MORNING. THIS HAS ONLY BEEN INTRODUCED FOR LWB AT THIS POINT...BUT WILL NEED TO KEEP AN EYE ON LYH/BCB AS THE NIGHT PROGRESSES. FOR LWB HAVE ONLY ADVERTISED MVFR...BUT GIVEN EXPECTED LOWS WELL DOWN INTO THE 50S/UPPER 40S...A BRIEF WINDOW OF IFR CANNOT BE COMPLETELY RULED OUT. WINDS...MOSTLY CALM/VRB03KT PIEDMONT AND WNW 3-5KTS WEST OF THE BLUE RIDGE OVERNIGHT...THEN WNW 5-9KTS ALL AREAS AFT 14Z TUE. HIGH CONFIDENCE IN A VFR FORECAST THROUGHOUT THE TAF VALID PERIOD...EXCEPT MEDIUM TO HIGH BECAUSE OF GROUND FOG POTENTIAL LWB/BCB/LYH 08Z-14Z TUE. MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION/SPEED THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... HIGH PRESSURE CONTROLS OUR WEATHER THROUGH MIDWEEK KEEPING IT VFR. MAY SEE SOME LATE NIGHT/EARLY MORNING PATCHY FOG THAT DISSIPATES QUICKLY AFTER SUNRISE IN THE FAVORED TERMINALS LWB/BCB. INCREASED CHANCES FOR SHOWERS/THUNDERSTORMS EARLY NEXT WEEK AS MOISTURE FROM THE SOUTHEAST STATES WORKS ITS WAY NORTHWARD INTO THE EASTERN U.S. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS/KK/WP NEAR TERM...DS/KK SHORT TERM...JH LONG TERM...JH AVIATION...KK/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
738 PM EDT MON AUG 24 2015 .SYNOPSIS... A COLD FRONT WILL TRACK ACROSS THE AREA THIS EVENING...EXITING THE PIEDMONT BY MIDNIGHT TONIGHT. HIGH PRESSURE WILL THEN EXTEND EASTWARD FROM THE PLAINS TUESDAY INTO THURSDAY...BRING A DRIER AIRMASS. && .NEAR TERM /THROUGH TUESDAY/... AS OF 630 PM EDT MONDAY... KFCX 88D RADAR WAS DETECTING ISOLATED SHOWERS...AND EVEN MORE ISOLATED...THUNDERSTORMS ACROSS PARTS OF SOUTHSIDE VIRGINIA. THIS ACTIVITY WAS LOCATED ALONG AND EAST OF A COLD FRONT THAT IS MOVING THROUGH THE AREA...CURRENTLY NEAR A MARTINSVILLE TO LYNCHBURG LINE. THE CONVECTION WILL CONTINUE MAKING PROGRESS EASTWARD INTO THE EVENING HOURS...AND EXIT THE REGION BETWEEN 1000 PM AND 1100 PM. HAVE MADE MINOR ADJUSTMENTS TO THE FORECAST CHANCE OF PRECIPITATION FOR THE NEXT COUPLE OF HOURS. HAVE FOCUSED ON PUTTING HIGHER POPS IMMEDIATELY DOWNSTREAM OF THE CURRENT ACTIVITY WHERE CONFIDENCE IN A CONTINUATION OF THE PRECIPITATION IS HIGHEST. AS OF 310 PM EDT MONDAY... SURFACE COLD FRONT IN THE WESTERN MOUNTAINS THIS AFTERNOON WILL TRAVEL EAST THIS EVENING INTO TONIGHT. PRE-FRONTAL TROUGH IN THE PIEDMONT TRIGGERING SCATTERED CONVECTION IN THE MOIST UNSTABLE AIR. SPC MESOSCALE ANALYSIS AT 18Z INDICATED SFC BASED CAPES FROM 1 TO 2K J/KG EAST OF THE BLUE RIDGE MOUNTAINS. THE DEEP LAYER MOISTURE FLUX CONVERGENCE WAS ENHANCED JUST EAST OF BLUE RIDGE MOUNTAINS. THE DAY ONE CONVECTIVE OUTLOOK KEEPS OUR AREA IN GENERAL THUNDERSTORMS. THE BETTER THREAT FOR STRONGER AND MORE ORGANIZED CONVECTION REMAINS TO OUR NORTH WITH THE BETTER DYNAMICS. AN ISOLATED PULSE STRONG THUNDERSTORM MAY BE POSSIBLE IN THE EAST...BUT GIVEN MARGINAL INSTABILITY...LACK OF ROBUST UPDRAFTS AND WEST FLOW...SEVERE WEATHER IS NOT EXPECTED. DEEP LAYER SHEAR WILL REMAIN INSUFFICIENT FOR SEVERE CONVECTIVE ORGANIZATION. LEANED POPS TOWARDS HRRR FOR THIS AFTERNOON INTO THIS EVENING...THEN BLENDED ISC GRIDS TOWARDS SUPERBLEND FOR TONIGHT INTO TUESDAY. THE COLD FRONT WILL SLOW AND STALL TO OUR EAST ALONG THE COASTAL PLAIN TONIGHT INTO TUESDAY...AS A WAVE OF LOW PRESSURE LIFTS NORTHWARD ALONG THE BOUNDARY. HIGH PRESSURE WILL BUILD EAST INTO OUR REGION TONIGHT INTO TUESDAY. DRIER AIR WILL LAG A FEW HOURS AS USUAL BEHIND THE MAIN FRONT...BUT SHARP DEWPOINT DROPS NOTED IN THE OHIO VALLEY. SHAPED LOW TEMPERATURES IN THE WESTERN MOUNTAINS TO COOLER COOP MOS VALUES. IT SHOULD BE A GOOD NIGHT TO OPEN THE WINDOWS WITH LOW TEMPERATURES FROM THE UPPER 40S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT CLOSER TO FRONTAL BOUNDARY. ALOFT THE UPPER PATTERN CONTINUES WITH AN EASTERN TROF AND GREAT LAKES CLOSED LOW SLOWING TRAVELING EAST TUESDAY. UNDER PLENTY OF SUNSHINE...HIGH TEMPERATURES WILL BE BELOW NORMAL WITH READINGS FROM THE UPPER 60S IN THE NORTHWEST MOUNTAINS TO THE MID 80S IN THE PIEDMONT. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 230 PM EDT MONDAY... LARGE LONGWAVE UPPER TROUGH FOR LATE AUGUST WILL BE SLIDING EAST ACROSS THE REGION DURING THE WEEK ALLOWING COOL SURFACE HIGH PRESSURE TO BUILD INTO AND NORTH OF THE AREA BY THURSDAY. THIS SHOULD KEEP OVERALL SUBSIDENCE IN PLACE PER DEEPER MOISTURE TO THE EAST ALONG THE RESIDUAL FRONT...WITH LOW LEVEL DRY AIR SUPPORTIVE OF COOL NIGHTS AND MOSTLY SUNNY DAYS THROUGH THE PERIOD. HOWEVER MID LEVEL SHORTWAVE ENERGY ROTATING THROUGH THE 5H TROUGH WILL HAVE TO BE WATCHED FOR POSSIBLE INTERACTION WITH MOISTURE TO THE EAST ESPECIALLY LATE IN THE PERIOD...AND EARLY ON FOR MORE UPSLOPE INDUCED CLOUDS WEST EARLY WEDNESDAY. GIVEN THAT LATEST FORECAST SOUNDINGS CONTINUE TO SHOW PLENTY OF LOW LEVEL DRY AIR IN PLACE WILL ONLY BOOST CLOUDS A BIT AND LEAVE OUT POPS FOR NOW. OTHERWISE TEMPS THE MAIN CONCERN GIVEN THE ARRIVAL OF THE COOLEST AIR ALOFT WEDNESDAY MORNING...AND SUBSEQUENT REINFORCING POCKETS OF 85H COOL ADVECTION INTO THURSDAY. HOWEVER TIMING OF SHORTWAVE ENERGY EARLY WEDNESDAY SUGGESTS PERHAPS MORE UPSLOPE CLOUDS FAR WEST AND SOME MIXING OUTSIDE OF THE VALLEYS GIVEN THE SURFACE HIGH STILL WELL UPSTREAM. THUS BUMPED UP LOWS A CATEGORY OR SO WEDNESDAY MORNING WITH ONLY THE DEEPEST VALLEYS SEEING A FEW 40S AND MAINLY 50S ELSEWHERE. NOT QUITE AS COOL THURSDAY MORNING BUT STILL 50S WEST TO LOW 60S EAST GIVEN A SLIGHT REBOUND IN DEWPOINTS OUT EAST. EXPECT HIGHS TO RECOVER TO JUST BELOW SEASONAL LEVELS PENDING HEATING OF DRY AIR SO TRENDED CLOSER TO THE LATEST MOS BLEND FOR HIGHS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 1245 PM EDT MONDAY... UPPER TROUGH WILL BE LIFTING OUT ACROSS THE REGION LATE IN THE WEEK RESULTING IN BRIEF ZONAL 5H FLOW BEFORE ANOTHER WEAKER SHORTWAVE TROUGH DROPS SE AROUND THE UPPER RIDGE TO THE WEST AND INTO THE AREA EARLY NEXT WEEK. THIS SHOULD ALLOW A RATHER LARGE AREA OF HIGH PRESSURE TO THE NORTH LATE IN THE WEEK TO SETTLE SOUTH AND OVERHEAD DURING THE WEEKEND BEFORE WEAKENING INTO NEXT WEEK. MOST MODELS DEPICT THIS SCENARIO IN KEEPING DEEPER MOISTURE WITH THE OLD FRONT NEAR THE COAST WITH PERHAPS THE REMNANT WAVE OF DANNY SPAWNING A WEAK LOW OFF THE SOUTHEAST COAST EARLY NEXT WEEK. HOWEVER GUIDANCE ALSO INDICATES JUST ENOUGH TROPICAL MOISTURE RETURN BY DAYS 6/7 UNDER THE WEAKENING SURFACE RIDGE AND SLIGHT COOLING ALOFT TO BRING A RETURN OF LEAST SOME DIURNAL ISOLATED/SCATTERED MAINLY MOUNTAIN CONVECTION FROM LATE SATURDAY INTO MONDAY. OTRW SHOULD BE MAINLY DRY WITH SEASONAL TEMPS EARLY IN THE PERIOD...THEN A REBOUND TOWARD HOTTER AND MORE HUMID CONDITIONS BY EARLY NEXT WEEK...WITH HIGHS 80S TO PERHAPS NEAR 90 SOUTHEAST AS RETURN FLOW DEVELOPS. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 730 PM EDT MONDAY... GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF VALID PERIOD. A DRY AIR MASS WILL SPREAD EASTWARD ACROSS THE REGION OVERNIGHT...WITH THE LAST VESTIGES OF THE HIGHER DEWPOINT/RH VALUES ACROSS THE PIEDMONT BEING PUSHED FURTHER EAST TOWARD THE COAST BY TUESDAY. ISOLATED SHRA/TSRA ASSOCIATED WITH THE PRE- FRONTAL TROUGH ACROSS THE PIEDMONT WILL DISSIPATE QUICKLY WITHIN THE NEXT HOUR. OTHERWISE...EXPECTING MOSTLY SKC/SCT250 OVERNIGHT...THEN SKC EAST TO FEW STRATOCUMULUS WEST IN THE 050-060 RANGE TUESDAY AFTERNOON. ONLY POSSIBILITY OF MARRING AN OTHERWISE VFR FORECAST THROUGH THE TAF VALID PERIOD IS PATCHY RADIATIONAL FOG LATE TONIGHT/EARLY TUESDAY MORNING. THIS HAS ONLY BEEN INTRODUCED FOR LWB AT THIS POINT...BUT WILL NEED TO KEEP AN EYE ON LYH/BCB AS THE NIGHT PROGRESSES. FOR LWB HAVE ONLY ADVERTISED MVFR...BUT GIVEN EXPECTED LOWS WELL DOWN INTO THE 50S/UPPER 40S...A BRIEF WINDOW OF IFR CANNOT BE COMPLETELY RULED OUT. WINDS...MOSTLY CALM/VRB03KT PIEDMONT AND WNW 3-5KTS WEST OF THE BLUE RIDGE OVERNIGHT...THEN WNW 5-9KTS ALL AREAS AFT 14Z TUE. HIGH CONFIDENCE IN A VFR FORECAST THROUGHOUT THE TAF VALID PERIOD...EXCEPT MEDIUM TO HIGH BECAUSE OF GROUND FOG POTENTIAL LWB/BCB/LYH 08Z-14Z TUE. MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION/SPEED THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... HIGH PRESSURE CONTROLS OUR WEATHER THROUGH MIDWEEK KEEPING IT VFR. MAY SEE SOME LATE NIGHT/EARLY MORNING PATCHY FOG THAT DISSIPATES QUICKLY AFTER SUNRISE IN THE FAVORED TERMINALS LWB/BCB. INCREASED CHANCES FOR SHOWERS/THUNDERSTORMS EARLY NEXT WEEK AS MOISTURE FROM THE SOUTHEAST STATES WORKS ITS WAY NORTHWARD INTO THE EASTERN U.S. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...KK/WP NEAR TERM...DS/KK SHORT TERM...JH LONG TERM...JH AVIATION...KK/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
218 PM EDT SUN AUG 23 2015 .SYNOPSIS... HIGH PRESSURE HEADS EAST TODAY WITH A COLD FRONT PRESSING INTO THE OHIO AND TENNESSEE VALLEYS. THE FRONT MOVES ACROSS US MONDAY...WITH A LARGE HIGH SHIFTING OVER THE NORTHERN PLAINS. THIS HIGH WILL GIVE US LOWER HUMIDITIES FOR MID TO LATE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM EDT SUNDAY... FOR TODAY...WE WILL SEE THE WESTERN FORECAST AREA REMAIN IN THE HIGHER THETA-E AIR AHEAD OF A STRONGER SHORTWAVE OVER WESTERN TENN THIS MORNING. THIS WAVE IS EXPECTED TO SHIFT EAST INTO THE SMOKYS/GA AREA BY MID AFTERNOON. SW FLOW AHEAD OF IT WILL AID IN MOISTURE ADVECTION. CLOUD COVER WILL BE PROBLEMATIC IN TERMS OF CONVECTION BUT THINK WILL BE ENOUGH SUNSHINE TO ALLOW CONVECTIVE TEMPS TO BE EXCEEDED...WITH THUNDERSTORMS A GOOD BET OVER THE NORTH CAROLINA MOUNTAINS AND FOOTHILLS NW INTO SW VA/SRN WV BY LATE AFTERNOON. WITH THE 10 AM UPDATE...DECREASED RAIN CHANCES FOR THE MORNING ACROSS THE MOUNTAINS...WITH RAIN CHANCES INCREASING DURING THE AFTERNOON. RAINFALL WILL BE MAINLY SHOWER ACTIVITY...BUT WITH A FEW THUNDERSTORMS DEVELOPING AS WE APPROACH MAX AFTERNOON HEATING. FOLLOWED A COMBINATION OF THE LOCAL WRF AND HRRR WEATHER FORECAST MODELS...WHICH DEPICTS BEST LIFT AND CONCENTRATION OF SHOWERS AND STORMS OVER THE MOUNTAINS SOUTH OF HIGHWAY 460...THEN START TO BLEND IN THE 0Z GFS/NAM AFTER MID AFTERNOON. BELIEVE THE PIEDMONT AREA EAST OF LYNCHBURG AND DANVILLE WILL SEE LITTLE TO NONE AS AXIS OF SFC RIDGE KEEPS THINGS SUPPRESSED. FOR HIGHS TODAY...MADE ONLY MINOR CHANGES TO THE TEMPERATURE FORECAST BASED ON CLOUD COVER. EXPECT SEASONAL TEMPS FROM THE MID TO UPPER 70S HIGHER TERRAIN OF NC TO LOWER 80S OVER MOST OF THE WESTERN CWA...WITH MID TO UPPER 80S FROM ROANOKE EAST. TONIGHT...THE UPPER WAVE PIVOTS EAST AND WE SHOULD SEE THINGS DRY OUT. MAY STILL ALLOW FOR A FEW SHOWERS ALONG THE BLUE RIDGE LATE EVENING. NEXT THREAT WILL BE MAINLY AFTER THIS PERIOD WITH THE COLD FRONT MONDAY...SO HAVE SLIGHT CHANCE POPS INTO THE WV MOUNTAIN AROUND DAWN MONDAY. SOME DIFFERENCES IN CLOUD COVER TONIGHT...BUT OVERALL SHOULD BE CLEARING FOR MOST WITH CLOUDS INCREASING AGAIN LATE IN THE WEST. LOWS WITH HUMIDITY STAYING UP WILL BE IN THE 60S. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... AS OF 315 AM EDT SUNDAY... THE UPPER PATTERN WILL BE FIRMLY ESTABLISHED IN AN AMPLIFIED EASTERN TROF/WESTERN RIDGE WITH A CLOSED LOW MEANDERING THROUGH THE GREAT LAKES REGION. THIS WILL KEEP THE HEAT LOCKED UP OUT WEST AND GIVE US SOME PLEASANT LATE SUMMER WEATHER FOR THE MIDDLE OF THE WEEK. HOWEVER...TO GET TO THIS PLEASANT WEATHER WE HAVE TO GET ON THE OTHER SIDE OF A COLD FRONT BEING DRAGGED THROUGH THE REGION ON MONDAY BY A LARGE SURFACE LOW OVER SOUTHERN CANADA. THE FRONT WILL ARRIVE IN THE WEST A BIT TO EARLY TO ACCESS SIGNIFICANT DIURNAL INSTABILITY...BUT AREAS EAST OF THE BLUE RIDGE WILL BE ABLE TO HEAT UP CONSIDERABLY RIGHT AHEAD OF THE FRONT. THUS...EXPECT THE FRONT WILL ENTER FROM THE WEST IN THE MORNING THEN JUMP TO THE LEE TROF EAST OF THE BLUE RIDGE FOR THE AFTERNOON AND KEEP MOST OF THE CONVECTIVE ACTIVITY ACROSS THE PIEDMONT. WILL INDICATE THIS IN THE GRIDS WITH HIGHEST POPS EAST AND SOMEWHAT LOWER POPS THROUGH THE MIDDLE. THE SEVERE THREAT IS LOW AS SUPPORTING SYNOPTIC DYNAMICS ARE LARGELY ABSENT BUT THE AIRMASS WILL BE QUITE JUICY AHEAD OF THE FRONT SO LOCALLY HEAVY RAIN WILL BE A POSSIBILITY. THE FRONT LOOKS TO PUSH OFF TO THE EAST MONDAY EVENING FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING IN FROM THE NORTHERN PLAINS. TEMPERATURES ON MONDAY WILL WARM INTO THE LOWER 90S ACROSS THE PIEDMONT AHEAD OF THE FRONT...BUT TO THE WEST READINGS WILL BE TEMPERED BY THE EARLY ARRIVAL OF THE FRONT AND WILL PEAK IN THE UPPER 70S/AROUND 80. HIGHS TUESDAY AND WEDNESDAY WILL BE SEASONABLE TO SLIGHTLY BELOW NORMAL WITH LOW HUMIDITY. EXPECT LOW/MID 80S EAST AND GENERALLY MIDDLE 70S WEST. THE COOLNESS BEHIND THE FRONT WILL REALLY BE FELT IN LOW TEMPERATURES WITH READINGS NEAR 60 EAST TO LOWER 50S WEST AND SOME 40S IN THE VALLEYS MAKING FOR DEPARTURES OF 5F TO 10F BELOW NORMAL. && .LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 220 PM EDT SATURDAY... AN UPPER LEVEL TROUGH WILL KEEP THE REGION RELATIVELY COOL AND DRY THROUGH THE REST OF THE WEEK. THE TROUGH AXIS WILL REMAIN OVER THE OHIO-TENN VALLEY WEDNESDAY...THEN PIVOT OVER THE APPALACHIANS ON THURSDAY. IF ENOUGH MOISTURE IS AVAILABLE...A FEW MOUNTAIN SHOWERS MAY DEVELOP THURSDAY AND MORE SCATTERED COVERAGE FRIDAY AND SATURDAY AFTERNOON. AVERAGE AFTERNOON TEMPERATURES WILL BE CLOSE TO SEASONAL LEVELS WITH ABUNDANT SUNSHINE AND DRY AIR. OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT WILL RUN COOLER THAN NORMAL BY 10F OR SO. OVERNIGHT LOWS WILL DROP INTO THE 50S WITH SOME MOUNTAIN VALLEYS DIPPING INTO THE 40S. OVERNIGHT LOWS WILL RETURN TO NORMAL BY THE WEEKEND. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... AS OF 200 PM EDT SUNDAY... RADAR INDICATES SCATTERED SHOWERS ACROSS THE HIGHLANDS OF NORTH CAROLINA INTO WESTERN VIRGINIA AND EXTREME SOUTHEAST WEST VIRGINIA... SO FAR ONLY PASSING NEAR KBLF. RAPID UPDATE MODELS INDICATE THAT A FEW OF THESE SHOWERS WILL INTENSIFY INTO THUNDERSTORMS FROM TIME TO TIME THROUGH EARLY EVENING...AS COVERAGE OF RAINFALL SPREADS NORTH AND EAST...POTENTIALLY CLIPPING KLWB...KBCB AND PERHAPS KROA DURING THE EVENING. MAIN CONCERN IS LOCALLY HEAVY RAIN WITH THIS ACTIVITY...WHICH WILL REDUCE SURFACE VISIBILITIES TO LESS THAN 1SM FOR BRIEF PERIODS OF TIME. CONVECTION WILL FADE WITH LOSS OF HEATING DURING LATE EVENING. OVERNIGHT...EXPECT ANOTHER ROUND OF PATCHY FOG...MAINLY IN THE RIVER VALLEYS AND OVER AREAS THAT RECEIVED SIGNIFICANT RAINFALL THIS AFTERNOON. MID LEVEL CLOUDS MOVING IN AHEAD OF AN APPROACHING COLD FRONT WILL KEEP FOG LOCALIZED. A COLD FRONT WILL PASS FROM WEST TO EAST ACROSS THE CENTRAL APPALACHIANS ON MONDAY. 12Z MODEL GUIDANCE MAINTAINS ONLY MODEST COVERAGE OF SHOWER ACTIVITY AHEAD OF THE FRONT...AND WITH LIMITED INSTABILITY...THUNDERSTORM ACTIVITY IS EXPECTED TO BE ISOLATED TO WIDELY SCATTERED AT BEST. OVERALL...VFR CONDITIONS ARE EXPECTED... ALTHOUGH ANY LOCALLY HEAVY RAIN WILL REDUCE VISIBILITIES FOR BRIEF PERIODS OF TIME. DRIER AIR WILL RETURN TO THE AREA WITH FRONTAL PASSAGE...RESULTING IN A DECREASE IN CLOUD COVER. EXTENDED AVIATION DISCUSSION... SURFACE HIGH PRESSURE BUILDS INTO THE AREA FOR THE TUESDAY THROUGH THURSDAY TIME PERIOD. MOST AREAS SHOULD EXPERIENCE VFR CONDITIONS. LATE NIGHT/EARLY MORNING PATCHY FOG WILL BE POSSIBLE...BUT ANY THAT FORMS SHOULD DISSIPATE QUICKLY AFTER SUNRISE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...NF/WP SHORT TERM...MBS LONG TERM...RCS AVIATION...NF/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1216 PM CDT SUN AUG 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CDT SUN AUG 23 2015 MOST OF THE FORECAST SHIFT WAS SPENT TRYING TO BUILD IN DETAILS ON THE TRENDS IN THE WEATHER FROM THE STRONG CYCLONE OVER THE NORTHERN PART OF THE REGION. OVERALL...DIDNT GET THE STRENGTH OF STORMS OUT OF THE SYSTEM...AND MARGINAL WIND SHEAR AT BEST AND THIN INSTABILITY TONGUE HAD MUCH TO DO WITH THAT. GOES WATER VAPOR SHOWING THE VIGOROUS SHORTWAVE TROUGH EJECTING E-NE TOWARD KDLH AT 07Z WITH DEFORMATION PRECIPITATION SEEN ACROSS ND IN REGIONAL RADARS. LOCALLY...THE COLD FRONT IS PUSHING TOWARD ERN WI WITH LIGHT SHRA AHEAD OF THE FRONT AND SOME POST-FRONTAL SHRA ABOUT A COUNTY FURTHER WEST. MULTIPLE FRONTOGENETIC BANDS INDICATED IN THE RAP IN THE LOWER LEVELS. THESE WILL CONTINUE EAST AND OUT OF THE FORECAST AREA DURING THE EARLY MORNING HOURS. CLOUDS AND LOW-LEVEL SECONDARY TROUGH/FRONTAL AXIS ALONG MN/DAKOTAS BORDER IS SHIFTING TOWARD THE AREA AS WELL. AS THE SURFACE LOW SHIFTS EAST THROUGH SOUTHERN MANITOBA TODAY AND FILLS...MANY OF THE FORCING FEATURES WEAKEN...INCLUDING THE MN TROUGH AXIS AND CONVERGENCE ALONG IT. THE SYSTEM BECOMES A BROAD CYCLONIC FLOW SCENARIO WITH ONLY A WEAK REMNANT TROUGH AFFECTING NRN WI LATER THIS MORNING AND AFTERNOON. HAVE BROUGHT SOME ISO-SCT SHRA BACK IN ALONG AND NORTH OF I-94 FOR MAINLY THE 17-22Z WINDOW. THERE IS SOME SUGGESTION IN THE HI-RES MODELS THAT THIS COULD ALSO AFFECT CENTRAL WI. HAVE ALSO CONTINUED AFTERNOON WIND GUSTS OF 25-35 MPH...REMAINING BELOW WIND ADVISORY CRITERIA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 300 AM CDT SUN AUG 23 2015 CONFIDENCE IS ABOVE AVERAGE THROUGH THURSDAY WITH QUIET WEATHER EXPECTED AND BELOW NORMAL TEMPERATURES. ALONG AND NORTH OF I-94 TEMPERATURES WILL BE MUCH BELOW NORMAL. MONDAY WILL BE THE COLDEST DAY BEFORE MODERATION SLOWLY OCCURS...ESPECIALLY WEDNESDAY ON. HAVE LOWERED THE TEMPERATURES IN THE NORTH DOWN A NOTCH INTO THE UPPER 50S FOR HIGHS MONDAY AS THE COLD AIR POCKET SLIPS THROUGH UNDER THICK CLOUDS. ON MONDAY..MAY HAVE TO TREND TOWARD HIGHER SHRA CHANCES NORTHEAST OF I-94 MONDAY AFTERNOON DEPENDING ON THE TRACK OF WELL AGREED UPON SHORTWAVE TROUGH ENERGY. THIS WAVE IS ACTUALLY THE CURRENT MN VORTEX ROTATING AROUND THE LONGER WAVE TROUGH AND BACK IN FROM THE NORTH MONDAY. CURRENTLY THE TRACK APPEARS TO FAVOR NORTHEASTERN WI FOR SHRA...BUT WILL KEEP WATCH AS DIURNAL TIMING IS IDEAL FOR ENHANCED SHRA COVERAGE. MONDAY AGAIN WILL SEE GUSTY NORTHWEST WINDS OF 25-30 MPH IN THE AFTERNOON. RIDGE BUILDING THEN BEGINS AND DOMINATES THROUGH THURSDAY. SOME DIFFERENCES SHOW UP FRIDAY AND INTO SATURDAY. SOME RETURN FLOW WARMING OCCURS AND THE GFS IS MORE AGGRESSIVE WITH RIDGE BUILDING OVER THE NORTHERN CONUS. THE 23.00Z CANADIAN/ECMWF AND 21.18Z DGEX SOLUTIONS ARE AT ODDS WITH THE 23.00Z GFS...AS THEY ALL HAVE A CUTOFF LOW DRIFTING E/SE THROUGH NEB/IA LATE IN THE WEEK. HOWEVER...THE 23.00Z GEFS DOES HAVE SOME MEMBERS THAT PICK UP ON THE LOW AS WELL...SO IT LOOKS LIKE THAT MAY BE A BETTER SOLUTION FOR LATE WEEK. THIS WOULD BRING SOME RAIN CHANCES POSSIBLY CLOSE OR INTO THE AREA. WILL HAVE TO LET THIS ALL SHAKE OUT...AND WENT WITH CONSENSUS BLEND WHICH TURNS INTO SLIGHT && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1216 PM CDT SUN AUG 23 2015 A SFC THRU UPPER LEVEL LOW OVER SOUTHWEST ONT AT MID-DAY WILL MOVE SLOWLY EAST ACROSS ONT THRU TONIGHT/MON. WESTERN EDGE OF THE MVFR/ VFR STRATO-CU DECK WRAPPED AROUND THE SOUTHWEST SIDE OF THIS LOW WAS NEAR I-35 AT 17Z. DISTANCE-SPEED TOOL MOVES THIS EAST OF KRST BETWEEN 20-21Z AND THRU KLSE AROUND 00Z THIS EVENING. ONCE THESE CLOUDS EXIT...GOOD...BUT BREEZY/WINDY...VFR CONDITIONS EXPECTED THRU TONIGHT/MON MORNING. WEST-NORTHWEST WINDS 15-20KT G25-30KT WILL DIMINISH WITH SUNSET TO 10-15KTS FOR TONIGHT/EARLY MON MORNING. BY MID MORNING DIURNAL WARMING/MIXING WILL INCREASE WINDS TO AROUND 30015G25KT. SOUNDINGS SHOWING AS MUCH AS 30-35KTS OF WIND IN THE TOP OF THE MIXED LAYER BY LATE MORNING/EARLY MON AFTERNOON. WINDS AFTER 16-17Z MON INTO THE AFTERNOON HOURS EXPECTED TO BE AROUND 30020G30KT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM....BAUMGARDT AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
649 AM CDT SUN AUG 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CDT SUN AUG 23 2015 MOST OF THE FORECAST SHIFT WAS SPENT TRYING TO BUILD IN DETAILS ON THE TRENDS IN THE WEATHER FROM THE STRONG CYCLONE OVER THE NORTHERN PART OF THE REGION. OVERALL...DIDNT GET THE STRENGTH OF STORMS OUT OF THE SYSTEM...AND MARGINAL WIND SHEAR AT BEST AND THIN INSTABILITY TONGUE HAD MUCH TO DO WITH THAT. GOES WATER VAPOR SHOWING THE VIGOROUS SHORTWAVE TROUGH EJECTING E-NE TOWARD KDLH AT 07Z WITH DEFORMATION PRECIPITATION SEEN ACROSS ND IN REGIONAL RADARS. LOCALLY...THE COLD FRONT IS PUSHING TOWARD ERN WI WITH LIGHT SHRA AHEAD OF THE FRONT AND SOME POST-FRONTAL SHRA ABOUT A COUNTY FURTHER WEST. MULTIPLE FRONTOGENETIC BANDS INDICATED IN THE RAP IN THE LOWER LEVELS. THESE WILL CONTINUE EAST AND OUT OF THE FORECAST AREA DURING THE EARLY MORNING HOURS. CLOUDS AND LOW-LEVEL SECONDARY TROUGH/FRONTAL AXIS ALONG MN/DAKOTAS BORDER IS SHIFTING TOWARD THE AREA AS WELL. AS THE SURFACE LOW SHIFTS EAST THROUGH SOUTHERN MANITOBA TODAY AND FILLS...MANY OF THE FORCING FEATURES WEAKEN...INCLUDING THE MN TROUGH AXIS AND CONVERGENCE ALONG IT. THE SYSTEM BECOMES A BROAD CYCLONIC FLOW SCENARIO WITH ONLY A WEAK REMNANT TROUGH AFFECTING NRN WI LATER THIS MORNING AND AFTERNOON. HAVE BROUGHT SOME ISO-SCT SHRA BACK IN ALONG AND NORTH OF I-94 FOR MAINLY THE 17-22Z WINDOW. THERE IS SOME SUGGESTION IN THE HI-RES MODELS THAT THIS COULD ALSO AFFECT CENTRAL WI. HAVE ALSO CONTINUED AFTERNOON WIND GUSTS OF 25-35 MPH...REMAINING BELOW WIND ADVISORY CRITERIA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 300 AM CDT SUN AUG 23 2015 CONFIDENCE IS ABOVE AVERAGE THROUGH THURSDAY WITH QUIET WEATHER EXPECTED AND BELOW NORMAL TEMPERATURES. ALONG AND NORTH OF I-94 TEMPERATURES WILL BE MUCH BELOW NORMAL. MONDAY WILL BE THE COLDEST DAY BEFORE MODERATION SLOWLY OCCURS...ESPECIALLY WEDNESDAY ON. HAVE LOWERED THE TEMPERATURES IN THE NORTH DOWN A NOTCH INTO THE UPPER 50S FOR HIGHS MONDAY AS THE COLD AIR POCKET SLIPS THROUGH UNDER THICK CLOUDS. ON MONDAY..MAY HAVE TO TREND TOWARD HIGHER SHRA CHANCES NORTHEAST OF I-94 MONDAY AFTERNOON DEPENDING ON THE TRACK OF WELL AGREED UPON SHORTWAVE TROUGH ENERGY. THIS WAVE IS ACTUALLY THE CURRENT MN VORTEX ROTATING AROUND THE LONGER WAVE TROUGH AND BACK IN FROM THE NORTH MONDAY. CURRENTLY THE TRACK APPEARS TO FAVOR NORTHEASTERN WI FOR SHRA...BUT WILL KEEP WATCH AS DIURNAL TIMING IS IDEAL FOR ENHANCED SHRA COVERAGE. MONDAY AGAIN WILL SEE GUSTY NORTHWEST WINDS OF 25-30 MPH IN THE AFTERNOON. RIDGE BUILDING THEN BEGINS AND DOMINATES THROUGH THURSDAY. SOME DIFFERENCES SHOW UP FRIDAY AND INTO SATURDAY. SOME RETURN FLOW WARMING OCCURS AND THE GFS IS MORE AGGRESSIVE WITH RIDGE BUILDING OVER THE NORTHERN CONUS. THE 23.00Z CANADIAN/ECMWF AND 21.18Z DGEX SOLUTIONS ARE AT ODDS WITH THE 23.00Z GFS...AS THEY ALL HAVE A CUTOFF LOW DRIFTING E/SE THROUGH NEB/IA LATE IN THE WEEK. HOWEVER...THE 23.00Z GEFS DOES HAVE SOME MEMBERS THAT PICK UP ON THE LOW AS WELL...SO IT LOOKS LIKE THAT MAY BE A BETTER SOLUTION FOR LATE WEEK. THIS WOULD BRING SOME RAIN CHANCES POSSIBLY CLOSE OR INTO THE AREA. WILL HAVE TO LET THIS ALL SHAKE OUT...AND WENT WITH CONSENSUS BLEND WHICH TURNS INTO SLIGHT && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 648 AM CDT SUN AUG 23 2015 AN UPPER LEVEL WILL MOVE NORTHEAST ACROSS NORTHERN MINNESOTA AND WESTERN ONTARIO THROUGH TONIGHT. THIS LOW WILL PRODUCE A BROKEN DECK OF MVFR CLOUDS THROUGH EARLY AFTERNOON...AND A 3 TO 5K DECK OF CLOUDS FROM MID AFTERNOON INTO THE EVENING AT THE TAF SITES. A TIGHT PRESSURE GRADIENT WILL PRODUCE SUSTAINED WEST WINDS OF 15 TO 25 KNOTS...AND WIND GUSTS IN THE 25 TO 35 KNOT RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 AM CDT SUN AUG 23 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CDT SUN AUG 23 2015 MOST OF THE FORECAST SHIFT WAS SPENT TRYING TO BUILD IN DETAILS ON THE TRENDS IN THE WEATHER FROM THE STRONG CYCLONE OVER THE NORTHERN PART OF THE REGION. OVERALL...DIDNT GET THE STRENGTH OF STORMS OUT OF THE SYSTEM...AND MARGINAL WIND SHEAR AT BEST AND THIN INSTABILITY TONGUE HAD MUCH TO DO WITH THAT. GOES WATER VAPOR SHOWING THE VIGOROUS SHORTWAVE TROUGH EJECTING E-NE TOWARD KDLH AT 07Z WITH DEFORMATION PRECIPITATION SEEN ACROSS ND IN REGIONAL RADARS. LOCALLY...THE COLD FRONT IS PUSHING TOWARD ERN WI WITH LIGHT SHRA AHEAD OF THE FRONT AND SOME POST-FRONTAL SHRA ABOUT A COUNTY FURTHER WEST. MULTIPLE FRONTOGENETIC BANDS INDICATED IN THE RAP IN THE LOWER LEVELS. THESE WILL CONTINUE EAST AND OUT OF THE FORECAST AREA DURING THE EARLY MORNING HOURS. CLOUDS AND LOW-LEVEL SECONDARY TROUGH/FRONTAL AXIS ALONG MN/DAKOTAS BORDER IS SHIFTING TOWARD THE AREA AS WELL. AS THE SURFACE LOW SHIFTS EAST THROUGH SOUTHERN MANITOBA TODAY AND FILLS...MANY OF THE FORCING FEATURES WEAKEN...INCLUDING THE MN TROUGH AXIS AND CONVERGENCE ALONG IT. THE SYSTEM BECOMES A BROAD CYCLONIC FLOW SCENARIO WITH ONLY A WEAK REMNANT TROUGH AFFECTING NRN WI LATER THIS MORNING AND AFTERNOON. HAVE BROUGHT SOME ISO-SCT SHRA BACK IN ALONG AND NORTH OF I-94 FOR MAINLY THE 17-22Z WINDOW. THERE IS SOME SUGGESTION IN THE HI-RES MODELS THAT THIS COULD ALSO AFFECT CENTRAL WI. HAVE ALSO CONTINUED AFTERNOON WIND GUSTS OF 25-35 MPH...REMAINING BELOW WIND ADVISORY CRITERIA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 300 AM CDT SUN AUG 23 2015 CONFIDENCE IS ABOVE AVERAGE THROUGH THURSDAY WITH QUIET WEATHER EXPECTED AND BELOW NORMAL TEMPERATURES. ALONG AND NORTH OF I-94 TEMPERATURES WILL BE MUCH BELOW NORMAL. MONDAY WILL BE THE COLDEST DAY BEFORE MODERATION SLOWLY OCCURS...ESPECIALLY WEDNESDAY ON. HAVE LOWERED THE TEMPERATURES IN THE NORTH DOWN A NOTCH INTO THE UPPER 50S FOR HIGHS MONDAY AS THE COLD AIR POCKET SLIPS THROUGH UNDER THICK CLOUDS. ON MONDAY..MAY HAVE TO TREND TOWARD HIGHER SHRA CHANCES NORTHEAST OF I-94 MONDAY AFTERNOON DEPENDING ON THE TRACK OF WELL AGREED UPON SHORTWAVE TROUGH ENERGY. THIS WAVE IS ACTUALLY THE CURRENT MN VORTEX ROTATING AROUND THE LONGER WAVE TROUGH AND BACK IN FROM THE NORTH MONDAY. CURRENTLY THE TRACK APPEARS TO FAVOR NORTHEASTERN WI FOR SHRA...BUT WILL KEEP WATCH AS DIURNAL TIMING IS IDEAL FOR ENHANCED SHRA COVERAGE. MONDAY AGAIN WILL SEE GUSTY NORTHWEST WINDS OF 25-30 MPH IN THE AFTERNOON. RIDGE BUILDING THEN BEGINS AND DOMINATES THROUGH THURSDAY. SOME DIFFERENCES SHOW UP FRIDAY AND INTO SATURDAY. SOME RETURN FLOW WARMING OCCURS AND THE GFS IS MORE AGGRESSIVE WITH RIDGE BUILDING OVER THE NORTHERN CONUS. THE 23.00Z CANADIAN/ECMWF AND 21.18Z DGEX SOLUTIONS ARE AT ODDS WITH THE 23.00Z GFS...AS THEY ALL HAVE A CUTOFF LOW DRIFTING E/SE THROUGH NEB/IA LATE IN THE WEEK. HOWEVER...THE 23.00Z GEFS DOES HAVE SOME MEMBERS THAT PICK UP ON THE LOW AS WELL...SO IT LOOKS LIKE THAT MAY BE A BETTER SOLUTION FOR LATE WEEK. THIS WOULD BRING SOME RAIN CHANCES POSSIBLY CLOSE OR INTO THE AREA. WILL HAVE TO LET THIS ALL SHAKE OUT...AND WENT WITH CONSENSUS BLEND WHICH TURNS INTO SLIGHT CHANCES FOR RAIN AND HIGHS RETURNING TO NEAR NORMAL BY SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1137 PM CDT SAT AUG 22 2015 MAINLY MVFR TO VFR CONDITIONS AS COLD FRONT PUSHES THROUGH AREA OVERNIGHT. AREA OF SHOWERS AND THUNDERSTORMS ALONG AND BEHIND FRONT HAS GENERATED SOME LOCALIZED IFR CONDITIONS...BUT THIS ENTIRE AREA WILL SWING THROUGH THE NEXT FEW HOURS. THERE WILL BE A BRIEF DRY SLOT TO CONTEND WITH...BUT THEN SOME CLOUDS TO DEAL WITH ON BACK SIDE OF SHORT WAVE AS IT CONTINUES EAST. HAVE ATTEMPTED TO TIME THIS INTO TAF SITES BUT NOT OVERLY CONFIDENT HOW FAR SOUTH CLOUD SHIELD WILL GET OR LAST. STRONG WEST TO NORTHWEST WINDS ON BACK SIDE OF SYSTEM AS WELL ON SUNDAY...BUT SKIES SHOULD CLEAR AND WINDS SHOULD SUBSIDE HEADING INTO SUNDAY EVENING LEADING UP TO AN EXTENDED PERIOD OF VFR WEATHER IT APPEARS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1035 PM MST MON AUG 24 2015 .UPDATE...UPDATED AVIATION DISCUSSION... .SYNOPSIS... HIGH PRESSURE HAS BECOME REESTABLISHED TO THE NORTHEAST OF ARIZONA...WHICH WILL RESULT IN HIGHER THAN NORMAL RAIN CHANCES ACROSS THE LOWER DESERTS THROUGH TUESDAY. DRIER CONDITIONS WILL SLOWLY RETURN BY THE MIDDLE AND END OF THE WEEK ALONG WITH ABOVE NORMAL TEMPERATURES. WELL ABOVE NORMAL TEMPERATURES ARE POSSIBLE BY THE WEEKEND. && .DISCUSSION... A BIT OF A DOWN-DAY MONSOON-WISE ACROSS SOUTH-CENTRAL ARIZO0NA SO FAR HIS EVENING WHEN COMPARED WITH YESTERDAY. ALTHOUGH THUNDERSTORMS DID DEVELOP AS FORECAST ACROSS THE RIM COUNTY AND WHITE MOUNTAINS THIS AFTERNOON...WITH THESE STORMS TRYING TO MOVE INTO THE LOWER ELEVATIONS...DRIER AIR IN THE MID-LEVELS OF THE ATMOSPHERE THAT WAS ADVECTED SOUTHWESTWARD INTO THE LOWER DESERTS OF SOUTH-CENTRAL ARIZONA HAS SO FAR KEPT THUNDERSTORM ACTIVITY QUITE LIMITED ACROSS THE LOWER DESERTS...WITH MOST OF THE ACTIVITY LIMITED TO EXTREME NORTH AND NORTHWEST MARICOPA COUNTY. GIVEN THESE TRENDS...HAVE DECIDED TO CUT BACK POPS FOR THE REST OF THE EVENING ACROSS THE LOWER DESERTS. AS FAR AS THE FORECAST FOR THE REST OF THE NIGHT AND EARLY TUESDAY...HAVE DECIDED TO LEAVE OUR CURRENT ELEVATED POPS ALONE ACROSS SOUTHWEST AZ LATER TONIGHT AND EARLY TUESDAY...SINCE THE LATEST HIGH-RES MODEL RUNS CONTINUE TO SHOW DEBRIS CLOUDS AND SHOWERS FROM STORMS OVER NORTHERN MEXICO MOVING NORTHWARD AS A WEAK SHORTWAVE MOVES INTO THE REGION...WITH THESE SAME MODELS SHOWING MORE THUNDERSTORM DEVELOPMENT TUESDAY AFTERNOON OVER SOUTH-CENTRAL AZ. && .PREVIOUS DISCUSSION... PREDOMINANT MIDLEVEL SUBTROPICAL HIGH PRESSURE HAS BECOME ESTABLISHED OVER FAR SOUTHEAST UTAH THIS AFTERNOON...WITH A COMBINATION OF WEAK MCVS AND INVERTED TROUGHS ROTATING ABOUT THE SRN PERIPHERY OF THIS ANTI-CYCLONE IN NRN MEXICO. 12Z REGIONAL SOUNDINGS DEPICTED EROSION OF CAPPING ALOFT WITH MOIST H5 TEMPERATURES COOLING TO -7C TO -8C YIELDING MIDLEVEL LAPSE RATES STEEPER THAN USUAL FOR THE MONSOON SEASON. ON THE OTHER HAND...SFC- H7 MOISTURE LEVELS WERE SAMPLED SLIGHTLY LOWER THAN THE PAST COUPLES DAYS (ONLY 10-11 G/KG) LEADING TO MLCAPES SUBSTANTIALLY LOWER ONLY AROUND 500 J/KG. SEVERAL CONFLICTING SIGNALS REGARDING CONVECTIVE COVERAGE AND PROPAGATION THIS AFTERNOON AND EVENING. OBJECTIVELY ANALYZED DEEP EASTERLY OR NORTHEASTERLY FLOW WOULD GENERALLY PROMOTE DEEPER OUTFLOW BOUNDARIES MARCHING INTO LOWER ELEVATIONS FROM HIGH TERRAIN STORM INITIATION POINTS. HOWEVER...THE NORTHEASTERLY TRAJECTORY HAS ACTUALLY BEEN ADVECTING SLIGHTLY DRIER AIR OVER HIGH TERRAIN...LOWERING INSTABILITY AND HINDERING ORGANIZED STORM FORMATION. STRONGER JET LEVEL DIFFLUENCE WAS LOCATED IN NRN MEXICO...AND SHOULD BEGIN FORMULATING NORTHWARD BUT POSSIBLY NOT UNTIL LATER THIS EVENING AIDING IN LARGE SCALE ASCENT. MORNING TRENDS IN THE HRRR AS WELL AS 12Z LOCAL WRF CORES SUGGESTED INCREASING CONFIDENCE OF DEEP CONVECTION ERUPTING THROUGHOUT THE MOGOLLON RIM AND WHITE MOUNTAINS...WITH FAVORABLE STEERING FLOW BRINGING DEEP OUTFLOWS AND LINEAR ASCENT TOWARDS THE PHOENIX METRO. HOWEVER...LATEST HRRR TRENDS AND EARLY/MID AFTERNOON RADAR IMAGERY YIELD HIGHER UNCERTAINTY ESPECIALLY WITH SFC DEWPOINTS NOW FALLING INTO THE MID/UPPER 50S. SHOULD MORE BACKED WINDS UPSTREAM AT H7 AND BETTER MOISTURE IN THIS LAYER BE ADVECTED WESTWARD...THAN MORE WIDESPREAD THUNDERSTORMS WOULD BE POSSIBLE. REGARDLESS...ANY ACTIVITY AFFECTING CNTRL ARIZONA MAY BE MORE DELAYED INTO THE EVENING HOURS. BY TUESDAY AND WEDNESDAY...THE THREAT FOR SCATTERED SHOWER AND STORM ACTIVITY WILL CONTINUE NEARLY AREAWIDE...PEAKING TUESDAY AS A MORE PRONOUNCED UPSTREAM INVERTED TROUGH AND SYNOPTIC SCALE UPPER DIVERGENCE ROTATES THROUGH THE FORECAST AREA. MODELS INDICATE DEEP MOISTURE PROFILES PUSHING BEHIND CONVECTIVE OUTFLOW EARLY TUESDAY MORNING...WITH PWATS IN A 1.75 TO 2 INCH RANGE (NEARLY THE 90TH PERCENTILE OF NAEFS MEAN). ALONG WITH THE ELEVATED POP CHANCES...SIGNIFICANT DAYTIME CLOUD COVER SHOULD WORK TO LIMIT DAYTIME HIGHS...OR AT LEAST DRAWING THEM BACK TO SEASONAL NORMALS /104 FOR PHOENIX AND 106 FOR YUMA/. HIGH TEMPERATURES COULD EASILY BE COOLER FOR LOCALES AFFECTED BY THICKER CLOUD COVER AND RAIN- COOLED OUTFLOWS...AND BUFR SOUNDINGS AND ENSEMBLE MAJORITY MODEL OUTPUT SUPPORT SUB-100 DEGREE HIGHS OVER MUCH OF SOUTHEAST CALIFORNIA. PRECIPITATION CHANCES WILL BEGIN TO DECREASE WEST TO EAST ON WEDNESDAY AND FOCUS MORE ACROSS THE FOUR CORNERS REGION AS THE AFOREMENTIONED TROUGH/SHORTWAVE SHIFTS NORTH IN RESPONSE TO THE REPOSITIONING RIDGE CENTER. THE RIDGE WILL BEGIN TO TRANSITION ACROSS NM DURING THE DAY WEDNESDAY AND GRADUALLY SINK SOUTHWARD INTO OLD MEXICO LATE WEDNESDAY INTO THURSDAY. ML AND UL FLOW WILL GRADUALLY TAKE UP SOUTHWESTERLY HEADINGS AGAIN...ONLY SLOWLY THINNING AND DRAWING DOWN MOISTURE THROUGH THE COLUMN. AS A RESULT...POP CHANCES START DECREASING MORE NOTABLY BEGINNING THURSDAY. AS THE UPPER HIGH SETTLES BACK TO OUR SOUTH AND DEWPOINTS/PWATS CONTINUE TO THIN...AIRMASS TEMPERATURES BEGIN TO WARM PROMPTING SFC TEMPERATURES TO ABOVE NORMAL READINGS BY THURSDAY AND THROUGH THE WEEKEND. THE WARMEST WESTERN DESERTS...INCLUDING EL CENTRO...YUMA AND TACNA...COULD HIT THE 110F MARK BY FRIDAY AND A DEGREE OR TWO WARMER BY THE WEEKEND. MEANWHILE LOCATIONS AROUND SOUTH-CENTRAL AZ...INCLUDING THE PHX METRO AND GILA BEND...COULD POTENTIALLY REACH THE 110F MARK BY THE WEEKEND. OVER THE LAST NORMAL PERIOD /1981- 2010/ THE AVERAGE LAST 110F DAY IN PHOENIX FALLS ON AUGUST 26TH /SEPTEMBER 6TH FOR YUMA/. WE COULD CERTAINLY PUSH PAST THE AVERAGE LAST DAY IN THE PHOENIX AREA BY THE WEEKEND...AND WORK TO CINCH THE TOP SPOT FOR THE WARMEST AUGUST ON RECORD AT BOTH LOCALES TO CLOSE OUT THE MONTH. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... AFTER A COUPLE MORE HOURS OF LIGHT WESTERLY WINDS AT KPHX AND KSDL...DUE TO OUTFLOW FROM DECAYING THUNDERSTORMS OVER NW MARICOPA COUNTY...WINDS ARE EXPECTED TO BECOME SOUTHEASTERLY FOR THE REST OF THE NIGHT AND INTO EARLY TUESDAY. CHANCES FOR THUNDERSTORMS INCREASE AGAIN ON TUESDAY AFTERNOON/EVENING...WHICH IS REFLECTED BY A WIND SHIFT AND VCTS IN THE TAFS. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... CLOUDS...AND A FEW LIGHT SHOWERS/THUNDERSTORMS FROM THE REMAINS OVER THUNDERSTORMS THAT ARE NOW OVER EXTREME SOUTHERN AZ AND NORTHERN MEXICO ARE EXPECTED TO MOVE OVER THE TAF SITES LATER TONIGHT AND EARLY TUESDAY...WHICH IS REFLECTED IN VCSH IN THE TAFS. THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS AGAIN ON TUESDAY AFTERNOON/EVENING...BUT CONFIDENCE IS TOO LOW TO INCLUDE TS IN THE TAFS...AT THIS TIME. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... WEDNESDAY THROUGH SUNDAY... ISOLATED SHOWERS AND THUNDERSTORMS WILL PERSIST WEDNESDAY AS FAR WEST AS SOUTHERN CALIFORNIA AS MOISTURE REMAINS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM. THEREAFTER...THE GENERAL TREND WILL BE TOWARDS DRIER AND WARMER CONDITIONS AS HIGH PRESSURE DRIFTS BACK TO THE SOUTH AND WEST. THE RESULTING SOUTHWESTERLY FLOW WILL RELEGATE ISOLATED STORM ACTIVITY PRIMARILY TO THE HIGHER TERRAIN OF EASTERN ARIZONA THURSDAY AND FRIDAY. ABOVE NORMAL TEMPERATURES AND BELOW NORMAL HUMIDITIES ARE EXPECTED BY FRIDAY AND WILL CONTINUE THROUGH THE WEEKEND. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT AND TERRAIN- DRIVEN AND CONSEQUENTLY AN ELEVATED FIRE DANGER IS NOT ANTICIPATED. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/MO/NOLTE AVIATION...PERCHA FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
327 AM EDT TUE AUG 25 2015 .SYNOPSIS... A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TODAY AS IT STALLS IN EASTERN NEW YORK. THE FRONT CROSSES SOUTHERN NEW ENGLAND TONIGHT MOVING OFFSHORE WEDNESDAY. MAINLY DRY AND SEASONABLE WEATHER WITH COMFORTABLE HUMIDITY LEVELS IS EXPECTED WEDNESDAY THROUGH SATURDAY. HUMIDITY AND ABOVE AVERAGE TEMPS RETURN FOR THE BEGINNING OF NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... *** A FEW STRONG TO SEVERE THUNDERSTORMS POSSIBLE IN INTERIOR SNE TODAY *** THROUGH 12Z...AREA OF SHOWERS AND A FEW TSTMS MOVING INTO W MA EARLY THIS MORNING. ACTIVITY IS ELEVATED AND HRRR INDICATES A WEAKENING TREND THROUGH DAYBREAK. MEANWHILE...A FEW SHOWERS DEVELOPING S OF THE COAST ASSOCD WITH MODEST SB INSTABILITY WITH STRONGER CONVECTION WELL S OF THE ISLANDS AND MOVING NE. THIS ACTIVITY MAY CLIP OUTER CAPE AND ACK BEFORE DAYBREAK...BUT HRRR SUGGESTS BULK OF THIS CONVECTION WILL SLIDE JUST TO THE E. TODAY...CLOSED UPPER LOW S OF JAMES BAY WITH MEAN TROF ACROSS GT LAKES AND SW CYCLONIC FLOW ACROSS NEW ENG. SFC COLD FRONT EXPECTED TO STALL INVOF HUDSON VALLEY AS IT IS PARALLEL TO UPPER FLOW. MAIN CONCERN FOR TODAY IS THE POTENTIAL FOR STRONG TO SEVERE TSTMS. MODELS SHOW A RAPID INCREASE IN INSTABILITY AFTER 12Z WITH CAPES 1000-2000 J/KG DEVELOPING...FOCUSED ACROSS THE INTERIOR. 0-6KM SHEAR INCREASES TO 35-40 KT SO EXPECT A FEW STRONG TO SEVERE TSTMS TO DEVELOP WITH POTENTIAL FOR ORGANIZED SEVERE WEATHER AND POSSIBLY A FEW SUPERCELLS GIVEN MAGNITUDE OF SHEAR/INSTABILITY. 0-1KM HELICITY IS NOT IMPRESSIVE BUT UPPER LEVEL PATTERN OF CLOSED LOW OVER SE CANADA FITS CLIMATOLOGY OF WEAK SNE TORNADOES SO CANT RULE OUT AN ISOLD BRIEF SPINUP. HI-RES GUIDANCE SHOWS ACTIVITY INCREASING DURING THE MORNING ACROSS W MA AND N CT THEN MOVING E INTO THE AFTERNOON. WHILE WE CANT RULE OUT A SHOWER OR TSTM IN THE COASTAL PLAIN...IT APPEARS MOST OF THE CONVECTION WILL REMAIN WEST OF BOS-PVD CORRIDOR TODAY. THE UNCERTAINTY FOR THE AFTERNOON IS THE EXTENT OF A POSSIBLE SECOND ROUND OF CONVECTION DEVELOPING IN W NEW ENG AS MID LEVEL DRYING WILL BE MOVING IN FROM THE WEST AND THIS COULD SUPPRESS ACTIVITY LATER IN THE AFTERNOON. LOWER CONFIDENCE ON POSSIBLE LATE DAY CONVECTION. IT WILL BE A RATHER HUMID DAY WITH DEWPOINTS INTO THE UPPER 60S TO LOWER 70S. && .SHORT TERM /TONIGHT/... COLD FRONT WILL BE MOVING EAST ACROSS SNE TONIGHT. MODELS SHOW INSTABILITY PERSISTING THROUGH THE NIGHT AND EVENTUALLY BECOMING FOCUSED ACROSS E NEW ENG LATE TONIGHT. A FEW EVENING STORMS POSSIBLE...BUT MID LEVEL DRYING MOVING IN FROM THE WEST AND RAPIDLY DECREASING KI WILL SUPPRESS ACTIVITY WITH ANY CONVECTION AFTER MIDNIGHT BEING CONFINED TO E NEW ENG IN HIGHER KI AXIS. PATCHY LATE NIGHT FOG EXPECTED. MIN TEMPS MOSTLY IN THE 60S...WITH SOME UPPER 50S W MA. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * MAINLY DRY/SEASONABLE WITH COMFORTABLE HUMIDITY WED THROUGH SAT * ABOVE NORMAL TEMPS AND HUMIDITY LOOKS TO RETURN EARLY NEXT WEEK OVERVIEW... 00Z GUIDANCE IS IN GOOD AGREEMENT FOR THIS PORTION OF THE FORECAST. THERE ARE SOME UNCERTAINTY WITH REGARDS TO THE STRENGTH OF A FEW PASSING SHORTWAVES BUT THIS SHOULD NOT IMPACT THE OVERALL TREND IN THE FORECAST. HIGH PRESSURE WILL REMAIN OVER THE REGION UNTIL SUNDAY BEFORE MOVING OFFSHORE. A WEAK WAVE ON SUNDAY MAY BRING A FEW SHOWERS WHILE HIGH PRESSURE WILL BUILD RIGHT BEHIND THIS WAVE. DAILIES... WEDNESDAY INTO SATURDAY...HIGH CONFIDENCE. BULK OF THE PRECIP TUESDAY/TUESDAY NIGHT WILL BE OFFSHORE BY WEDNESDAY MORNING. HOWEVER...BECAUSE THIS FRONT IS SLOW MOVING AND WITH CYCLONIC FLOW ALOFT...COULD SEE LINGERING SHOWERS ACROSS EASTERN MASS DURING THE DAY. COLD FRONT SHOULD BE OFFSHORE BY THE LATE AFTERNOON AND BEHIND IT COMFORTABLE TEMPS AND HUMIDITY. UPPER LEVEL PATTERN WILL TURN FROM TROUGH TO ZONAL AS SURFACE HIGH PRESSURE BUILDS ACROSS THE NORTHEAST. THIS WILL KEEP NEAR NORMAL TEMPS AND LOW HUMIDITY THROUGH THE REMAINDER OF THE PERIOD. SUNDAY AND BEYOND...LOW CONFIDENCE. GUIDANCE BEGINS TO DIVERGE DURING THIS PERIOD AS THERE ARE SOME UNCERTAINTIES ON THE STRENGTHS OF EACH SHORTWAVE MOVING THROUGH THE FLOW. FOR NOW APPEARS THAT A STRETCHED SHORTWAVE WILL PASS SOUTHERN NEW ENGLAND...AND COMBINED WITH SOUTHERLY WINDS/INCREASING HUMIDITY THIS COULD TRIGGER A FEW LIGHT SHOWERS LATE SATURDAY NIGHT INTO SUNDAY. TEMPERATURES WILL BEGIN TO TREND ABOVE AVERAGE STARTING ON SUNDAY AND INTO THE FIRST WEEK OF SCHOOL FOR SOME. BOTH MODELS AND ENSEMBLES ARE HINTING AT UPPER 80S TO LOW 90S FOR THE WORK-WEEK AS UPPER LEVEL RIDGE TRIES TO BUILD. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/... THROUGH 12Z...WIDESPREAD MVFR/IFR STRATUS NEAR THE S COAST WITH VFR MIXED WITH AREAS OF LOWER CIGS FURTHER INLAND. FOG NOT PREVALENT AND WITH SOUTHERLY FLOW EXPECT PATCHY FOG TO BE CONFINED MOSTLY TO THE SOUTH COAST. WIDELY SCT SHOWERS/TSTMS MOVING INTO W MA AND NW CT. TODAY...MODERATE CONFIDENCE. AREAS OF MVFR/IFR STRATUS IN THE MORNING...IMPROVING TO VFR. SCT SHOWERS/TSTMS WITH BRIEF MVFR/IFR EXPECTED IN THE MORNING W MA AND N CT...WITH A SECOND ROUND OF ACTIVITY POSSIBLE IN THE AFTERNOON...MAINLY INTERIOR. TONIGHT...MODERATE CONFIDENCE. EVENING SHOWERS/TSTMS WITH BRIEF MVFR/IFR POSSIBLE. MAY SEE SOME CONVECTION LINGER ACROSS E NEW ENG OVERNIGHT. PATCHY FOG DEVELOPING OVERNIGHT. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY THROUGH SATURDAY...VFR CONDITIONS. COULD SEE WEAK SEA BREEZES ALONG THE COASTLINES. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE. TODAY...S WINDS LESS THAN 20 KT WITH SEAS BELOW SCA. LOCALLY POOR VSBYS IN MORNING FOG. SCT SHOWERS AND ISOLD TSTMS SE WATERS THIS MORNING. TONIGHT...LIGHT S WINDS WITH SEAS BELOW SCA. VSBYS REDUCED IN PATCHY FOG. OUTLOOK /WEDNESDAY THROUGH SATURDAY/...HIGH CONFIDENCE. A PERIOD OF QUIET BOATING WEATHER IS EXPECTED THANKS TO BUILDING HIGH PRES. WINDS OUT OF THE W-NW THROUGH FRI...SHIFTING TO THE S BY SAT OR SUN. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/DUNTEN NEAR TERM...KJC SHORT TERM...KJC LONG TERM...DUNTEN AVIATION...KJC/DUNTEN MARINE...KJC/DUNTEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
158 AM EDT TUE AUG 25 2015 .SYNOPSIS... COLD FRONT APPROACHES FROM THE WEST TONIGHT AND CROSSES NEW ENGLAND TUESDAY NIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THIS FRONT. MAINLY DRY AND SEASONABLE WEATHER WITH COMFORTABLE HUMIDITY LEVELS FOLLOWS WEDNESDAY THROUGH SATURDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 150 AM UPDATE... A FEW SHOWERS AND ISOLD TSTMS MOVING NE INTO W MA AND HRRR BRINGS SOME CONVECTION INTO THE CT VALLEY EARLY THIS MORNING. MEANWHILE...AREA OF SHOWERS/ISOLD TSTMS WELL S OF THE ISLANDS ASSOCD WITH HIGHER THETA-E AIR LIFTING NE AND MAY CLIP THE OUTER CAPE AND ISLANDS BEFORE DAYBREAK. UPDATED POPS TO REFLECT LATEST RADAR AND HI-RES GUIDANCE TRENDS. PREVIOUS DISCUSSION... WIDELY SCT SHOWERS/TSTMS CONFINED TO THE WEST OF NEW ENG FROM E NY TO NE PA. ACTIVITY IS NOT MAKING MUCH PROGRESS EAST AS IT TRACKS SLOWLY NE. HRRR AND HIRES ARW BRING SOME ELEVATED CONVECTION INTO FAR W NEW ENG VERY LATE TONIGHT. IN ADDITION...WATCHING AREA OF SHOWERS WELL TO THE S ASSOCD WITH HIGHER THETA-E AIR AND SOME ELEVATED INSTABILITY. MODELS BRING THIS NWD ACROSS CAPE/ISLANDS LATE TONIGHT SO CANT RULE AN ISOLD SHOWER HERE OVERNIGHT AS WELL. OTHERWISE...MAINLY DRY OVERNIGHT. CURRENTLY WE HAVE 1000-1500 J/KG OF SBCAPE OFFSHORE TO THE S. MODELS BRING UP TO 1000 J/KG ACROSS SE NEW ENG TOWARD 12Z SO WILL HAVE TO WATCH FOR POSSIBLE DEVELOPMENT NEAR THE S COAST BUT THERE IS NO FORCING MECHANISM. STRATUS HAS DEVELOPED ALONG THE S COAST AND WITH LIGHT SOUTHERLY FLOW MAY SEE THIS ADVECT FURTHER NWD ACROSS SNE. PATCHY FOG POSSIBLE AS WELL...ESPECIALLY NEAR THE S COAST. A WARM AND HUMID NIGHT WITH MINS UPPER 60S TO AROUND 70 WITH SIMILAR DEWPOINTS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 AM WEDNESDAY/... CLOSED UPPER LOW MOVES TO EASTERN CANADA WITH CYCLONIC FLOW ACROSS THE EASTERN USA. SURFACE COLD FRONT IS FORECAST IN/NEAR THE HUDSON VALLEY AND ROUGHLY PARALLEL TO THE UPPER FLOW. THE GFS IS A LITTLE MORE PROGRESSIVE THAN THE ECMWF BUT BOTH HOLD THE FRONT EITHER SIDE OF THE NEW ENGLAND BORDER TUESDAY EVENING. BOTH MODELS THEN SWEEP THE FRONT EAST ACROSS NEW ENGLAND TUESDAY NIGHT. STABILITY PARAMETERS ARE FAVORABLE FOR CONVECTION WITH TOTALS MID TO UPPER 40S/LI AROUND ZERO/SBCAPE 1000-3000 J/KG. WIND FIELDS ALOFT ALSO PICK UP WITH SPEEDS NEAR 20 KNOTS AT 850 MB AND 40 KNOTS AT 500 MB. THE MOST FAVORABLE AREA FOR CONVECTION WOULD BE WESTERN/CENTRAL MASS AND POSSIBLY PARTS OF NORTHERN CT. THE BEST MODE OF DAMAGING WEATHER WOULD BE STRONG WIND GUSTS. WILL THERE BE A MORNING ROUND OF SHOWERS/TSTMS? BOTH THE GFS AND ECMWF INDICATE INCREASED SBCAPE OVER RI AND SOUTHEAST MASS AT 12Z. COULD BE A QUICK MORNING BURST. MAIN EVENT SHOULD BE FARTHER WEST IN THE AFTERNOON/EVENING. COLD FRONT THEN SLIPS THROUGH DURING TUESDAY NIGHT WITH SHOWERS/TSTMS ENDING...AND DRIER AIR FILTERING IN FROM THE WEST. PRECIPITABLE WATER VALUES WILL BE 1.5 TO 1.75 INCHES...SO LOCALLY HEAVY DOWNPOURS POSSIBLE. TEMPS AT 900 MB ARE EQUIV TO 13C AT 850 MB...MAX SFC TEMPS IN THE LOW TO MID 80S EXCEPT COOLER ALONG THE COAST AND IN THE HIGHER HILLS. MIN SFC TEMPS SHOULD REMAIN IN THE 60S IN THE EAST BUT WILL REACH THE UPPER 50S IN WESTERN MASS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * MAINLY DRY/SEASONABLE WITH COMFORTABLE HUMIDITY WED THROUGH SAT * ABOVE NORMAL TEMPS AND HUMIDITY LOOKS TO RETURN EARLY NEXT WEEK OVERVIEW AND MODEL PREFERENCES... 24.12Z MODEL GUIDANCE IS SHOWING LITTLE DIFFERENCE THROUGH MUCH OF THE LONG TERM. AT THE VERY LEAST ANY DIFFERENCES ARE MINIMAL ENOUGH SO AS NOT TO IMPACT THE FORECAST SIGNIFICANTLY. AT THE VERY LEAST...THE PATTERN SHIFT WE HAVE BEEN WAITING FOR NOW FOR ALMOST A WEEK IS AT HAND. UPPER LVL CUTOFF MOVES INTO QUEBEC/LABRADOR ALTHOUGH WITH A SLIGHT REMNANT OF THE ATTENDANT TROF ACROSS THE NE CONUS THROUGH THE END OF THE WEEK. A ZONAL FLOW PATTERN WILL FINALLY DEFINE MUCH OF THE NRN PERIPHERY OF THE CONUS...WITH DRIER CP AIRMASS DRAW INTO NEW ENGLAND. NOTING A SLIGHT SLACKENING OF THE MASS FIELDS TO THE S BY LATE IN THE WEEKEND...WHICH COULD SHIFT THE FLOW PATTERN INCREASING TEMPS/DWPTS AND A RISK FOR SCT PRECIPITATION. WITH THE AGREEMENT...A BLEND OF OPERATIONAL GUIDANCE WILL BE USED. DETAILS... WED... MODELS CONTINUE TO INDICATE THE POSSIBILITY OF WEAK CYCLOGENESIS IN THE GULF OF MAINE ALONG THE SLOW MOVING COLD FRONT. COMBINE THIS WITH STRONG CYCLONIC/COLD UPPER FLOW WITH THE UPPER LVL CUTOFF MAKING IT/S CLOSEST PASS...AND WILL LIKELY SEE A FAIR AMOUNT OF DIURNAL AND LEFTOVER CLOUD COVER THROUGH THE DAY...ALTHOUGH IT WILL LIKELY REMAIN DRY. A SPOT SHOWER CAN/T BE RULED OUT AS BUFKIT DATA SUPPORTS A WEAK UNSTABLE LATER NEAR THE TOP OF THE BL WHICH COULD BE JUST ENOUGH TO SQUEEZE OUT WHAT LITTLE MOISTURE IS THERE. IN SPITE OF THE -10 TO -11C H5 TEMPERATURES...FEEL RISK FOR SMALL HAIL IS LOW IN SPITE OF THE GOOD SETUP AS THERE IS A FAIRLY PRONOUNCED WARM LAYER BETWEEN H8 AND H6. H85 TEMPERATURES BETWEEN 12 AND 14C SHOULD BE REALIZED AT LEAST...SO TEMPERATURES NEAR SEASONAL LEVELS /UPPER 70S AND LOW 80S/ ARE EXPECTED. THE BEST NEWS...DWPTS MAINLY IN THE 50S. THU AND FRI... PLEASANT CONDITIONS. LITTLE CHANGE IN MID LEVEL TEMPERATURES SUGGEST HIGHS REMAIN NEAR NORMAL. LOW DWPTS IN THE 50S...AND MAY EVEN DIP INTO THE 40S LOCALLY. OVERNIGHT MINS IN THE 50S. SAT AND SUN... ZONAL FLOW BUT WITH SRN NEW ENGLAND ON THE ANTICYCLONIC SHEAR SIDE. THEREFORE...FEEL THAT GFS IS A BIT OVERDONE TRYING TO BRING ABOUT SHRA ACTIVITY EACH AFTERNOON. FOR NOW WILL CONTINUE WITH NIL POPS. INCREASING MID LVL TEMPS AND MOISTURE ARE EXPECTED...ALTHOUGH ONLY SLIGHTLY THROUGH THE WEEKEND. EARLY NEXT WEEK... A STRONGER SHORTWAVE WILL ATTEMPT TO PHASE WITH THE SLACKENED MASS FIELDS S OF THE REGION. THIS MAY LEAD TO A SHIFT IN THE PATTERN SUCH THAT WARMING/MOISTENING IS EXPECTED. THE SFC REFLECTION LOOKS TO BE A WEAK WARM FRONT...WHICH COULD INCREASE THE RISK FOR SHRA/TSTORMS BY THIS TIME PERIOD. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/... THROUGH 12Z...WIDESPREAD MVFR/IFR STRATUS NEAR THE S COAST WITH VFR MIXED WITH AREAS OF LOWER CIGS FURTHER INLAND. FOG NOT PREVALENT AND WITH SOUTHERLY FLOW EXPECT PATCHY FOG TO BE CONFINED MOSTLY TO THE SOUTH COAST. WIDELY SCT SHOWERS/TSTMS MOVING INTO W MA AND NW CT. TODAY...MODERATE CONFIDENCE. AREAS OF MVFR/IFR STRATUS IN THE MORNING...IMPROVING TO VFR. SCT SHOWERS/TSTMS WITH BRIEF MVFR/IFR EXPECTED IN THE MORNING W MA AND N CT...WITH A SECOND ROUND OF ACTIVITY POSSIBLE IN THE AFTERNOON...MAINLY INTERIOR. TONIGHT...MODERATE CONFIDENCE. EVENING SHOWERS/TSTMS WITH BRIEF MVFR/IFR POSSIBLE. MAY SEE SOME CONVECTION LINGER ACROSS E NEW ENG OVERNIGHT. PATCHY FOG DEVELOPING OVERNIGHT. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR CONDITIONS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...MODERATE TO HIGH CONFIDENCE. TONIGHT...HIGH CONFIDENCE. SOUTH TO SOUTH WINDS 10-15 KT OR LESS. SEAS BELOW 5 FT. AREAS OF FOG WITH POOR VISIBILITY. SHOWERS/SCATTERED TSTMS MAY REACH THE WATERS TOWARD MORNING. TUESDAY...WINDS IN ANY TSTMS MAY GUST TO NEAR 35 KNOTS. LOCALLY POOR VSBYS IN MORNING FOG. OTHERWISE WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS. OUTLOOK /WEDNESDAY THROUGH SATURDAY/...HIGH CONFIDENCE. A PERIOD OF QUIET BOATING WEATHER IS EXPECTED THANKS TO SLOW MOVING HIGH PRES WHICH WILL GRADUALLY BUILD OVER THE WATERS THROUGH THE PERIOD. WINDS OUT OF THE W-NW THROUGH FRI...SHIFTING TO THE S SOMEWHAT BY SAT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/DOODY NEAR TERM...KJC SHORT TERM...WTB LONG TERM...DOODY AVIATION...KJC/DOODY MARINE...WTB/DOODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
313 AM CDT TUE AUG 25 2015 .SHORT TERM...(TODAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 DEEP UPPER TROF FOR LATE AUGUST SITUATED JUST NORTH OF LAKE HURON EARLY THIS MORNING IS FORECAST TO SLOWLY EDGE EAST OVER THE NEXT FEW DAYS. MEANWHILE...SEVERAL WEAK SHORTWAVES ROTATING SOUTHEAST INTO THE LOWER GREAT LAKES WITH ONE SUCH FEATURE NOW PUSHING ACROSS SOUTH CENTRAL LAKE MICHIGAN. THIS WAVE MAY HAVE BEEN RESPONSIBLE FOR PUSHING THE STRATOCUMULUS DECK A BIT FURTHER SOUTH THAN ANTICIPATED LATE YESTERDAY THROUGH EARLY THIS MORNING. AS THE WEAK UPPER LEVEL DISTURBANCE PUSHES FURTHER OFF TO OUR EAST WE SHOULD SEE THE CLOUD DECK CONTINUE THIN OUT ACROSS OUR NORTHERN COUNTIES. HOWEVER, ADDITIONAL PIECES OF ENERGY ARE SEEN ROTATING SOUTHWARD AROUND THE LARGE UPPER LOW AND THAT COMBINED WITH DAYTIME HEATING MAY LEAD TO A LEAST SOME SCATTERED CLOUD COVER ACROSS THE NORTH LATER THIS MORNING INTO THE AFTERNOON HOURS. RAP FORECAST SOUNDINGS ONCE AGAIN INDICATING SOME STEEP LOW AND MID LEVEL LAPSE RATES ASSOCIATED WITH THE BROAD CYCLONIC FLOW OVER THE REGION WHICH WILL LEAD TO SOME GUSTY WEST TO NORTHWEST WINDS LATE THIS MORNING THRU THIS AFTERNOON. 850 MB TEMPS A FEW DEGREES COOLER THAN WHAT WE HAD AROUND OUR AREA YESTERDAY WHICH SHOULD PRODUCE AFTERNOON HIGHS MOSTLY IN THE MIDDLE 70S. && .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 QUIET FORECAST AT LEAST UNTIL THE END OF THE WORK WEEK WITH HIGH TEMPS SLIGHTLY BELOW NORMAL, BUT SLOWLY WARMING THROUGH THE END OF THE WEEK AHEAD OF THE NEXT SYSTEM. OVERNIGHT LOWS ALSO ON THE COOL SIDE AT LEAST UNTIL THE CLOUDS INCREASE SOMEWHAT AHEAD OF THE NEXT SYSTEM THURSDAY NIGHT IN THE NORTHWEST. PRECIP ASSOCIATED WITH THE UPPER LEVEL WAVE, HOWEVER, NOT ANTICIPATED TO IMPACT CENTRAL ILLINOIS UNTIL FRIDAY NIGHT/SATURDAY MORNING. SOME SLIGHT CHANCES CREEPING INTO NW OF THE ILLINOIS RIVER VALLEY FOR FRIDAY, WITH CHANCES INCREASING THROUGH THE OVERNIGHT AND INTO SAT MORNING. UPPER LEVEL DISTURBANCE IS DIFFUSE AND SLOW MOVING IN BOTH THE GFS AND THE ECMWF. THE NAM IS STARTING TO COME IN A LITTLE MORE COMPACT AND QUICKER, SO NOT OVERLY CONFIDENT WITH ANY PARTICULAR SOLUTION. THE GFS AND ECMWF HAVE BEEN BACK AND FORTH ENOUGH OVER THE LAST SEVERAL SYNOPTIC RUNS THAT CONSENSUS IS WEAK. ALSO NOT INCLINED TO LEAVE CHANCE POPS IN THE FORECAST ALL THE WAY THROUGH THE WEEKEND WITH THAT SLOW OF A SYSTEM. FOR NOW, WILL KEEP THE CONCENTRATION TO SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1144 PM CDT MON AUG 24 2015 QUIET/VFR CONDTIONS EXPECTED TO PREVAIL ACROSS THE CENTRAL ILLINOIS TERMINALS THROUGH THE 06Z TAF VALID TIME. LOW CLOUDS SPINNING AROUND A LOW PRESSURE SYSTEM, CENTERED OVER NORTHERN ONTARIO, ARE SPILLING A LITTLE FURTHER SOUTH THAN PREVIOUSLY ANTICIPATED. THIS IS RESULTING IN CIGS FOR MUCH OF TONIGHT AT KPIA, KBMI, AND KCMI, BUT THEY SHOULD STILL REMAIN WELL INTO THE VFR CATEGORY. WEST TO NORTHWEST WINDS EXPECTED THROUGH THE PERIOD, WITH GUSTY WINDS DEVELOPING FOR MUCH OF THE DAYTIME HOURS TUESDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...BAK
AREA FORECAST DISCUSSION
NWS JACKSON KY
345 AM EDT TUE AUG 25 2015 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM EDT TUE AUG 25 2015 06Z SFC ANALYSIS SHOWS A LARGE AREA OF COOL AND DRY HIGH PRESSURE BUILDING INTO THE OHIO VALLEY FROM THE NORTHWEST. THIS HAS KEPT THE SKIES MOSTLY CLEAR DURING THE NIGHT AND ALLOWED FOR A GOOD NIGHT OF RADIATIONAL COOLING BELOW THE INVERSION. AS IS TYPICAL... THIS HAS RESULTED IN A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT RANGING FROM THE MID 50S IN SHELTERED LOCATIONS TO THE LOWER 60S ON THE RIDGES. DEWPOINTS MEANWHILE ARE IN THE LOW TO MID 50S ACROSS THE CWA WITH LIGHT WINDS FROM THE WEST ABOVE THE INVERSION. JUST A HINT OF VALLEY FOG IS NOTED IN THE MONTICELLO OBSERVATION AND IN SOME OF THE WEB CAMS. THE MODELS REMAIN IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THE ALL ARE VERY SIMILAR WITH THE DEEP... AND CLOSED...LOW SLOWLY MOVING INTO SOUTHEAST CANADA AND THE EASTERN GREAT LAKES TODAY THROUGH WEDNESDAY. THIS WILL PLACE THE OHIO VALLEY AND KENTUCKY IN THE MIDST OF LOW HEIGHTS WHILE WEAK PACKETS OF ENERGY MOVE BY AT MID LEVELS IN BROAD NORTHWEST FLOW. GIVEN THE MINUSCULE MODEL SPREAD WILL USE A GENERAL BLEND SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12. CAPITAL WEATHER WILL BE THE RULE THROUGH THE SHORT TERM WITH MINIMAL CLOUDS...LOW AFTERNOON HUMIDITIES...AND COOL NIGHTS. THE SFC HIGH PRESSURE WILL SPREAD OVER KENTUCKY AND KEEP THE BULK OF ANY CLOUDS...ASSOCIATED WITH THE PASSING UPPER LOW...TO A MINIMUM. HIGHS WILL END UP IN THE MID 70S FOR MOST SPOTS TODAY AND WEDNESDAY. AT NIGHT...LOOK FOR A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP IN CONJUNCTION WITH AN INVERSION SETTING UP. CANNOT RULE OUT PATCHY FOG IN THE MORE SHELTERED LOCATIONS TOWARDS DAWN THIS MORNING AND AGAIN ON WEDNESDAY MORNING. THE COOL AIR MAY SET A RECORD LOW TONIGHT AT JKL...CURRENTLY A MILD 58 DEGREES FROM 1984...BUT PROBABLY LOZ/S 46 DEGREE RECORD FROM 1966 WILL STAY OUT OF REACH. AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THIS EVENING BEFORE INITIATING WITH THE SUPERBLEND INTO WEDNESDAY EVENING. DID MAKE SOME DECENT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEN EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD... IN LINE WITH MOS GUIDANCE. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 333 AM EDT TUE AUG 25 2015 SFC HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL PROVIDE US WITH PLEASANT WEATHER FOR THE BEGINNING OF THE EXTENDED PERIOD. HOWEVER THIS WILL BE SHORT LIVED AS THE HIGH IS EXPECTED TO MOVE OFF TO THE EAST BY SATURDAY. THIS WILL ALLOW FOR WEAK RETURN FLOW TO USHER IN LL MOISTURE...HIGHER DEWPOINTS AND WARMER TEMPERATURES FOR THE WEEKEND. AN UPPER LEVEL SHORTWAVE AND ASSOCIATED FRONT WILL APPROACH THE AREA FROM THE PLAINS...BRINGING RENEWED CHANCES FOR PRECIP EACH AFTERNOON SATURDAY THROUGH MONDAY. THE BEST CHANCE FOR MEASURABLE PRECIP WILL LIKELY BE ON MONDAY AS THE UPPER LEVEL WAVE MOVES THROUGH OUR REGION. HOWEVER...THERE ARE SOME DIFFERENCES ON HOW THE MODELS HANDLE THIS UPPER LEVEL FEATURE...WHICH WILL ULTIMATELY DETERMINE HOW MUCH PRECIP WE COULD GET. SO FOR NOW HAVE STUCK CLOSE TO THE CR SUPERBLEND AND MAINTAINED SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES WILL BEGIN BELOW NORMAL ON THURSDAY BUT THEN GRADUALLY WARM THROUGH THE REST OF THE EXTENDED PERIOD WITH HIGHS RETURNING TO THE MID TO UPPER 80S BY MONDAY. HUMIDITY WILL FOLLOW THE SAME TREND...WITH DEWPOINTS INCREASING INTO THE MID 60S BY SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 220 AM EDT TUE AUG 25 2015 HIGH PRESSURE IS CONTINUING TO NOSE INTO EASTERN KY THIS NIGHT. THIS IS BRINGING DRIER AIR AND CLEAR SKIES TO THE REGION... TRANSLATING TO VFR CONDITIONS. THESE VFR CONDITIONS ARE EXPECTED TO THE PREVAIL THROUGH THE PERIOD AS THE HIGH FURTHER BUILDS OVER THE REGION. THE ONLY EXCEPTION MAY BE SOME PATCHY RIVER VALLEY FOG...BUT THIS IS NOT EXPECTED TO AFFECT ANY OF THE TAF SITES. WINDS WILL REMAIN LIGHT THROUGH 06Z WEDNESDAY...FROM THE WEST TO NORTHWEST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...JVM AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 AM EDT TUE AUG 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT TUE AUG 25 2015 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UNSEASONABLY DEEP CLOSED LO IN ONTARIO JUST NE OF LK SUP DRIFTING SLOWLY TO THE E... WITH SHARP CYC FLOW ARND THIS FEATURE DOMINATING THE GREAT LKS. LOCAL RAOBS INDICATE THE SFC-H7 LYR IS QUITE MOIST WITH H925...H85 AND H7 DEWPT DEPRESSIONS AT INL AND E NO MORE THAN A FEW DEGREES C. THERE ARE ALSO TWO SHRTWVS OF NOTE ROTATING ARND THE LARGER SCALE FEATURE. THE FIRST OF THESE IS NOW HEADING INTO NRN LK MI AT THE BEGINNING OF THE SHIFT AND TAKING THE MORE WIDESPREAD SHOWERS THAT HAD IMPACTED THE ERN CWA LAST EVNG TO THE SE WITH IT. IN THE WAKE OF THIS DISTURBANCE...SFC OBS AND THE MQT 88D INDICATE RELATIVELY FEW SHOWERS...MAINLY JUST SOME DRIZZLE...LINGER OVER UPR MI EARLY THIS MRNG DESPITE THE MOIST LLVLS AND SHARP CYC NW FLOW. THE CULPRITS APPEAR TO BE LARGER SCALE QVECTOR DVGC TO THE W OF THE CLOSED LO AND BEHIND THE DEPARTING SHRTWV AND RATHER SHARP H875-85 INVRN SHOWN ON THE 00Z INL/YPL RAOBS ASSOCIATED WITH THESE NEGATIVE DYNAMICS/HGT RISES THAT IS LIMITING THE LK EFFECT COMPONENT TO THE NE OF H85 THERMAL TROF CENTERED ON AN AXIS FM INL TO GRB. 00Z H85 TEMPS WERE 3C AT INL AND GRB...BUT 10C AT YPL. WV IMAGERY/RAP ANALYSIS INDICATE ANOTHER SHRTWV ROTATING SWD TO THE W OF THE CLOSED LO IS DROPPING THRU NW ONTARIO. THE LATEST THUNDER BAY RADAR SHOWS AN AREA OF MORE NMRS SHOWERS OVER LK NIPIGON MOVING INTO NRN LK SUP. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS ASSOCIATED SHRTWV ROTATING SWD ARND SLOWLY DEPARTING CLOSED LO. TODAY...WHILE ONTARIO SHRTWV MOVING TO THE S IS ON TRACK TO MOVE INTO NRN LK SUP THIS MRNG...MODELS INDICATE DEEP LYR QVECTOR DVGC AND HGT RISES...FCST TO BE ABOUT 50M BTWN 12Z-24Z TODAY...LEFT IN THE WAKE OF THE CLOSED LO WL DOMINATE. SO ALTHOUGH FCST PROFILES INDICATE SOME DEEPENING MSTR THRU THIS MRNG...THEY ALSO SHOW A NEAR ABSENCE OF ANY UVV...IN FACT MAINLY LARGE SCALE SUBSIDENCE THAT WL MAINTAIN THE INVRN NEAR H85 AND LIMIT POPS. THE ERN CWA HAS A BETTER CHC TO SEE THE HIER POPS...AS THIS AREA WL BE CLOSER TO THE DEPARTING DISTURBANCE/WEAKER SUBSIDENCE WITH AT LEAST SOME UVV/ SHARPER CYC FLOW AND DOWNSTREAM OF LK SUP IN PERSISTENT NW FLOW THAT WL ACCENTUATE LLVL CNVGC. GIVEN THESE NEGATIVES...TENDED TO LOWER GOING POPS. PLENTY OF LO CLDS WL LIMIT THE DIURNAL TEMP RECOVERY AGAIN DESPITE SLOWLY MODERATING H85 TEMPS THAT WL ALLOW FOR A WARMER DAY THAN YDAY. THE STEADY/GUSTY NW WINDS WL CONTINUE TO WHIP UP HI WAVES ON LAKE SUP...RESULTING IN A HI SWIM RISK FOR MARQUETTE AND ALGER COUNTIES. TNGT...WITH CONTINUED SLOW HGT RISES/DEEP LYR QVECTOR DVGC/WEAKENING LLVL CYC FLOW TO THE W OF WEAKENING CLOSED LO THAT IS FCST TO LIFT NE TOWARD THE S END OF JAMES BAY BY 12Z WED...EXPECT DIMINISHING POPS. THIS TREND WL BE MOST PRONOUNCED OVER THE W...WHERE THE LLVL FLOW WL BECOME MORE ACYC CLOSER TO APRCHG SFC HI PRES MOVING INTO MN. LINGERING LO CLDS WL LIMIT THE DIURNAL TEMP FALL. EXPECT THE COOLEST OVERNGT LOWS TOWARD THE MID 40S OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLRG LATE WITH THE APRCH OF THE SFC HI PRES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 251 AM EDT TUE AUG 25 2015 COULD SEE SOME ISOLATES SHOWERS OVER THE ERN CWA WED MORNING AS NW WINDS AND 850MB TEMPS OF 5-6C ALLOW FOR LAKE ENHANCED RAIN...BUT OVERALL FORCING WILL BE WEAK. HIGH PRESSURE MOVING IN WILL BRING AN END TO RAIN POTENTIAL BY WED AFTERNOON. HIGHS WED IN THE 60S WILL COMBINE WITH GOOD RADIATIONAL COOLING...DRY CONDITIONS AND LIGHT WINDS WED NIGHT TO BRING LOWS IN THE 40S INLAND...WITH A FEW SPOTS IN THE UPPER 30S. SW FLOW AS THE HIGH MOVES OUT WILL BRING 850MB TEMPS UP TO 14C BY THE END OF THE DAY THU...RESULTING IN NEAR NORMAL HIGHS IN THE LOW TO MID 70S. DRY WEATHER PERSISTS THROUGH THU. MODELS CONTINUE TO INDICATE A COLD FRONT MOVING S FROM CANADA AND INTO THE CWA THU NIGHT AND FRI WHILE A SHORTWAVE RIDES DOWN NW FLOW AND PASSES OVER OR NEAR THE CWA. MODELS HAVE BEEN VARIABLE WITH SOLUTIONS FOR THIS TIME PERIOD...BUT THE ECMWF HAS BEEN THE MOST STEADY. OVERALL...CHANCES FOR SHOWERS AND THUNDERSTORMS SEEM REASONABLE. PRECIP IS QUESTIONABLE FOR SAT...BUT COULD SEE SOME SHOWERS IF SHORTWAVE ENERGY MOVES THROUGH. LEFT SLIGHT CHANCE POPS FOR NOW. TEMPS LOOK SIMILAR TO FRI. TEMPS LOOK TO BE ABOVE NORMAL SUN AND MON WITH DRY WEATHER AS RIDGING BUILDS OVER THE AREA. HIGHS SHOULD RANGE FROM THE MID/UPPER 70S TO LOW 80S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 124 AM EDT TUE AUG 25 2015 A GUSTY NW FLOW OF COOL...MOIST AIR AROUND LOW PRES TO THE NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO KIWD/KCMX/KSAW THRU MUCH OF THE FCST PERIOD. IN GENERAL...KCMX WILL SEE THE WORST CONDITIONS...WITH OCCASIONAL HEAVIER SHRA AND SOME PERIODS OF IFR CONDITIONS AT TIMES MAINLY THIS MORNING DUE TO A MORE PRONOUNCED UPSLOPE WIND COMPONENT. ALSO EXPECT THE STRONGEST WINDS AT THE MORE EXPOSED KCMX TERMINAL. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT TUE AUG 25 2015 SHARP PRES GRADIENT ON THE WESTERN FLANK OF DEEP LO PRES MOVING THRU ONTARIO TO THE E OF LAKE SUPERIOR WILL MAINTAIN NW WINDS UP TO 30 KTS TODAY. THE PASSAGE OF A DISTURBANCE THIS MORNING MAY CAUSE SOME GALE FORCE GUSTS IN A CORRIDOR OVER THE CENTRAL LAKE. BUT AS THE LO TO THE E WEAKENS AND MOVES TOWARD JAMES BAY TONIGHT...APPROACHING HI PRES/WEAKENING PRES GRADIENT WILL CAUSE WINDS TO DIMINISH W-E. AS THE HI MOVES OVER THE UPPER LAKES LATE WED/WED NIGHT...EXPECT WINDS TO FALL UNDER 20 KTS. A RELATIVELY FLAT PRES GRADIENT WILL DOMINATE LATE WEEK INTO THE WEEKEND...SO WINDS FOR THE MOST PART SHOULD BE UNDER 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
252 AM EDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 440 PM EDT MON AUG 24 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN UNSEASONABLY DEEP MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION WITH 500MB HEIGHT ANOMALIES OF 2.5 STANDARD DEVIATIONS BELOW THE LONG TERM LATE AUG AVG. SEVERAL SHORTWAVES ARE ROTATING AROUND THE CIRCULATION. ONE IS JUST E OF LAKE SUPERIOR...ANOTHER IS NEAR LAKE NIPIGON AND A THIRD IS MOVING ACROSS WRN UPPER MI. SHRA HAD NOT BEEN AS NMRS AS EXPECTED OVER UPPER MI UNTIL RECENTLY WHEN SHORTWAVE REACHED WRN UPPER MI. FOR MUCH OF THE DAY OVER LAKE SUPERIOR...THERE HAD BEEN A RATHER SOLID BAND OF SHRA...EXTENDING FROM AROUND LAKE NIPIGON SE AND E TO ERN LAKE SUPERIOR IN SHARP CYCLONIC FLOW/ZONE OF WAA/RATHER FOCUSED THETA-E ADVECTION. 850MB THERMAL TROF WITH 850MB TEMPS AS LOW AS 1C AT KINL PER 12Z RAOBS RUNS FROM NRN MN INTO NRN WI/SRN UPPER MI AND TOWARD LWR MI. ON LATEST WATER VAPOR IMAGERY...SHORTWAVE NEAR LAKE NIPIGON LOOKS QUITE VIGOROUS...AND CANADIAN RADARS SHOW DECENT SHIELD OF SHRA ADVANCING S WITH FEATURE. THUS...EXPECT ANOTHER INCREASE IN SHRA COVERAGE OVER THE W IN THE NEXT FEW HRS. MEANWHILE...SHORTWAVE CURRENTLY MOVING ACROSS WRN UPPER MI WILL SPREAD INCREASED SHRA ACTIVITY EASTWARD INTO THE ERN FCST AREA. AT THE SAME TIME... VEERING WINDS WILL HELP PUSH THE SHRA OVER THE ERN LAKE SE INTO THE ERN FCST AREA AS WELL. LAKE NIPIGON SHORTWAVE WILL THEN CONTINUE TO AID SHRA ACTIVITY OVER THE E THRU LATE EVENING INTO AT LEAST THE EARLY OVERNIGHT. OTHERWISE...DEEP CYCLONIC FLOW AND WEAK WAA WILL CONTINUE TO SUPPORT SCT/NMRS SHRA OVERNIGHT. 850MB TEMPS WILL BE LOW ENOUGH...ESPECIALLY ALONG SRN PORTIONS OF LAKE SUPERIOR WHERE WARMEST WATER RESIDES...TO ADD A LAKE COMPONENT TO PCPN AS WELL. UPSLOPE COMPONENT TO PCPN WILL BE GREATEST OVER THE WRN FCST AREA. ALTHOUGH MID LEVEL LOW DRIFTS FARTHER E ON TUE AND HEIGHT RISES CONTINUE...LINGERING DEEP CYCLONIC FLOW/UPSLOPING AND SOME LAKE COMPONENT WILL KEEP SHRA GOING...ESPECIALLY IN THE AREAS NORMALLY FAVORED BY NW WINDS OFF LAKE SUPERIOR. HOWEVER...COVERAGE OF SHRA SHOULD TEND TO SHOW SOME DIMINISHING TREND DURING THE DAY. IT WILL BE ANOTHER UNSEASONABLY COOL DAY UNDER ABUNDANT CLOUD COVER. COOLEST CONDITIONS (MID 50S FOR MAX TEMPS) WILL BE ACROSS THE HIGHER TERRAIN AND WHERE PCPN IS MOST FREQUENT. NEW RECORD LOW MAX TEMPS MAY BE SET AT SOME LOCATIONS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 251 AM EDT TUE AUG 25 2015 COULD SEE SOME ISOLATES SHOWERS OVER THE ERN CWA WED MORNING AS NW WINDS AND 850MB TEMPS OF 5-6C ALLOW FOR LAKE ENHANCED RAIN...BUT OVERALL FORCING WILL BE WEAK. HIGH PRESSURE MOVING IN WILL BRING AN END TO RAIN POTENTIAL BY WED AFTERNOON. HIGHS WED IN THE 60S WILL COMBINE WITH GOOD RADIATIONAL COOLING...DRY CONDITIONS AND LIGHT WINDS WED NIGHT TO BRING LOWS IN THE 40S INLAND...WITH A FEW SPOTS IN THE UPPER 30S. SW FLOW AS THE HIGH MOVES OUT WILL BRING 850MB TEMPS UP TO 14C BY THE END OF THE DAY THU...RESULTING IN NEAR NORMAL HIGHS IN THE LOW TO MID 70S. DRY WEATHER PERSISTS THROUGH THU. MODELS CONTINUE TO INDICATE A COLD FRONT MOVING S FROM CANADA AND INTO THE CWA THU NIGHT AND FRI WHILE A SHORTWAVE RIDES DOWN NW FLOW AND PASSES OVER OR NEAR THE CWA. MODELS HAVE BEEN VARIABLE WITH SOLUTIONS FOR THIS TIME PERIOD...BUT THE ECMWF HAS BEEN THE MOST STEADY. OVERALL...CHANCES FOR SHOWERS AND THUNDERSTORMS SEEM REASONABLE. PRECIP IS QUESTIONABLE FOR SAT...BUT COULD SEE SOME SHOWERS IF SHORTWAVE ENERGY MOVES THROUGH. LEFT SLIGHT CHANCE POPS FOR NOW. TEMPS LOOK SIMILAR TO FRI. TEMPS LOOK TO BE ABOVE NORMAL SUN AND MON WITH DRY WEATHER AS RIDGING BUILDS OVER THE AREA. HIGHS SHOULD RANGE FROM THE MID/UPPER 70S TO LOW 80S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 124 AM EDT TUE AUG 25 2015 A GUSTY NW FLOW OF COOL...MOIST AIR AROUND LOW PRES TO THE NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO KIWD/KCMX/KSAW THRU MUCH OF THE FCST PERIOD. IN GENERAL...KCMX WILL SEE THE WORST CONDITIONS...WITH OCCASIONAL HEAVIER SHRA AND SOME PERIODS OF IFR CONDITIONS AT TIMES MAINLY THIS MORNING DUE TO A MORE PRONOUNCED UPSLOPE WIND COMPONENT. ALSO EXPECT THE STRONGEST WINDS AT THE MORE EXPOSED KCMX TERMINAL. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 455 AM EDT MON AUG 24 2015 AN UNSEASONABLY DEEP LO PRES JUST N OF THUNDER BAY EARLY THIS MORNING WILL DRIFT SLOWLY TO THE ESE THRU TUE. UNDER THE SHARPER PRES GRADIENT ON THE SW FLANK OF THIS LO WHERE THE SURGE OF COOLER AIR IS MOST PRONOUNCED AND DESTABLIZATION IS GREATEST...WNW GALES UP TO 35 KTS WILL CONTINUE OVER THE SW HALF OF THE LAKE THRU THE AFTN. CANCELLED THE GALE WARNING FOR THE NCENTRAL PORTION OF THE LAKE AS THIS AREA HAS FALLEN UNDER A SLACKER GRADIENT CLOSER TO THE LO PRES. ADDED A MENTION OF WATERSPOUTS OVER THE EASTERN PORTION OF THE LAKE WHERE WATER TEMPERATURES ARE WARMEST AND WINDS MAY BE WEAKER FOR A TIME TODAY AHEAD OF AN APPROACHING LO PRES TROUGH MOVING AROUND THE LO JUST TO THE N. AS THE LO CONTINUES E OF LAKE SUPERIOR TONIGHT/TUE...NW GALES TO 35 KTS WILL BE POSSIBLE OVER MAINLY THE CENTRAL PORTION OF THE LAKE WHERE GUIDANCE HINTS THE PRES GRADIENT WILL BE SHARPEST. AS THE LO MOVES FARTHER TO THE E AND HI PRES TO THE W APPROACHES...THE PRES GRADIENT AND WINDS WILL DIMINISH W-E ON TUE NIGHT/WED. WINDS WILL BE UNDER 20 KTS FOR WED NIGHT THRU FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 440 PM EDT MON AUG 24 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN UNSEASONABLY DEEP MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION WITH 500MB HEIGHT ANOMALIES OF 2.5 STANDARD DEVIATIONS BELOW THE LONG TERM LATE AUG AVG. SEVERAL SHORTWAVES ARE ROTATING AROUND THE CIRCULATION. ONE IS JUST E OF LAKE SUPERIOR...ANOTHER IS NEAR LAKE NIPIGON AND A THIRD IS MOVING ACROSS WRN UPPER MI. SHRA HAD NOT BEEN AS NMRS AS EXPECTED OVER UPPER MI UNTIL RECENTLY WHEN SHORTWAVE REACHED WRN UPPER MI. FOR MUCH OF THE DAY OVER LAKE SUPERIOR...THERE HAD BEEN A RATHER SOLID BAND OF SHRA...EXTENDING FROM AROUND LAKE NIPIGON SE AND E TO ERN LAKE SUPERIOR IN SHARP CYCLONIC FLOW/ZONE OF WAA/RATHER FOCUSED THETA-E ADVECTION. 850MB THERMAL TROF WITH 850MB TEMPS AS LOW AS 1C AT KINL PER 12Z RAOBS RUNS FROM NRN MN INTO NRN WI/SRN UPPER MI AND TOWARD LWR MI. ON LATEST WATER VAPOR IMAGERY...SHORTWAVE NEAR LAKE NIPIGON LOOKS QUITE VIGOROUS...AND CANADIAN RADARS SHOW DECENT SHIELD OF SHRA ADVANCING S WITH FEATURE. THUS...EXPECT ANOTHER INCREASE IN SHRA COVERAGE OVER THE W IN THE NEXT FEW HRS. MEANWHILE...SHORTWAVE CURRENTLY MOVING ACROSS WRN UPPER MI WILL SPREAD INCREASED SHRA ACTIVITY EASTWARD INTO THE ERN FCST AREA. AT THE SAME TIME... VEERING WINDS WILL HELP PUSH THE SHRA OVER THE ERN LAKE SE INTO THE ERN FCST AREA AS WELL. LAKE NIPIGON SHORTWAVE WILL THEN CONTINUE TO AID SHRA ACTIVITY OVER THE E THRU LATE EVENING INTO AT LEAST THE EARLY OVERNIGHT. OTHERWISE...DEEP CYCLONIC FLOW AND WEAK WAA WILL CONTINUE TO SUPPORT SCT/NMRS SHRA OVERNIGHT. 850MB TEMPS WILL BE LOW ENOUGH...ESPECIALLY ALONG SRN PORTIONS OF LAKE SUPERIOR WHERE WARMEST WATER RESIDES...TO ADD A LAKE COMPONENT TO PCPN AS WELL. UPSLOPE COMPONENT TO PCPN WILL BE GREATEST OVER THE WRN FCST AREA. ALTHOUGH MID LEVEL LOW DRIFTS FARTHER E ON TUE AND HEIGHT RISES CONTINUE...LINGERING DEEP CYCLONIC FLOW/UPSLOPING AND SOME LAKE COMPONENT WILL KEEP SHRA GOING...ESPECIALLY IN THE AREAS NORMALLY FAVORED BY NW WINDS OFF LAKE SUPERIOR. HOWEVER...COVERAGE OF SHRA SHOULD TEND TO SHOW SOME DIMINISHING TREND DURING THE DAY. IT WILL BE ANOTHER UNSEASONABLY COOL DAY UNDER ABUNDANT CLOUD COVER. COOLEST CONDITIONS (MID 50S FOR MAX TEMPS) WILL BE ACROSS THE HIGHER TERRAIN AND WHERE PCPN IS MOST FREQUENT. NEW RECORD LOW MAX TEMPS MAY BE SET AT SOME LOCATIONS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 429 PM EDT MON AUG 24 2015 DAMP AND FALL-LIKE CONDITIONS WILL GIVE WAY TO MODERATION TOWARD MORE SEASONAL WEATHER BY THU INTO THE WEEKEND. A DEEP CLOSED MID/UPPER LEVEL LOW SOUTH OF JAMES BAY WILL GRADUALLY FILL AND MOVE INTO QUEBEC WED. RIDGING WILL THEN PUSH BACK TOWARD THE WESTERN LAKES BY THU INTO THE WEEKEND. TUE NIGHT AND WED...AS THE MID LEVEL LOW SHIFTS TO THE EAST...MODELS SUGGEST THAT MAINLY NNW FLOW WITH 330-340 WINDS WILL PREVAIL WITH 850 MB TEMPS REMAINING AROUND 6C INTO EARLY WED. WITH THE NNW FLOW AND MOST FAVORABLE MOISTURE OVER THE CNTRL AND ERN LAKE...EXPECT THE GREATEST -SHRA COVERAGE INTO N CNTRL UPPER MI EVEN AS THE AMOUNTS DIMINISH. THE PCPN WILL DIMINISH AND END WED AS THE DEEP MOISTURE SHIFTS TO THE EAST. MAX TEMPS ARE EXPECTED REBOUND BACK INTO THE MID TO UPPER 60S. WED NIGHT INTO THU...WITH FAVORABLE RADIATIONAL COOLING CONDITIONS AS THE SFC RIDGE BUILDS INTO THE AREA AND PWAT VALUES BLO 0.5 INCH...EXPECT INLAND MIN TEMPS INTO THE MID 40S INLAND. ABUNDANT SUNSHINE THU SHOULD PUSH TEMPS BACK TO SEASONAL AVERAGES IN THE LOWER TO MID 70S. FRI-MON...UNCERTAINTY INCREASES DUE TO MODEL DIFFERENCES IN HANDLING THE POSITION OF THE SFC FRONT AND IMPACT OF A SHRTWV MOVING OUT OF THE PLAINS. THE ECMWF HAS BEEN THE MOST CONSISTENT IN KEEPING MOST OF THE PCPN WITH THIS FEATURE SOUTH AND WEST OF WI. THIS WOULD ALLOW A WEAK SFC FRONT/TROUGH TO SLIDE TOWARD OR INTO UPPER MI. THE FRONT COMBINED WITH THE POTENTIAL FOR WNW FLOW SHRTWVS SUPPORTS CONTINUED CHANCE SHRA/TSRA POPS FRI INTO FRI NIGHT. THE MODELS HAVE TRENDED AWAY FROM PCPN FOR SAT INTO MON AS THE MID LEVEL RIDGE BUILDS INTO THE REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 124 AM EDT TUE AUG 25 2015 A GUSTY NW FLOW OF COOL...MOIST AIR AROUND LOW PRES TO THE NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO KIWD/KCMX/KSAW THRU MUCH OF THE FCST PERIOD. IN GENERAL...KCMX WILL SEE THE WORST CONDITIONS...WITH OCCASIONAL HEAVIER SHRA AND SOME PERIODS OF IFR CONDITIONS AT TIMES MAINLY THIS MORNING DUE TO A MORE PRONOUNCED UPSLOPE WIND COMPONENT. ALSO EXPECT THE STRONGEST WINDS AT THE MORE EXPOSED KCMX TERMINAL. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 455 AM EDT MON AUG 24 2015 AN UNSEASONABLY DEEP LO PRES JUST N OF THUNDER BAY EARLY THIS MORNING WILL DRIFT SLOWLY TO THE ESE THRU TUE. UNDER THE SHARPER PRES GRADIENT ON THE SW FLANK OF THIS LO WHERE THE SURGE OF COOLER AIR IS MOST PRONOUNCED AND DESTABLIZATION IS GREATEST...WNW GALES UP TO 35 KTS WILL CONTINUE OVER THE SW HALF OF THE LAKE THRU THE AFTN. CANCELLED THE GALE WARNING FOR THE NCENTRAL PORTION OF THE LAKE AS THIS AREA HAS FALLEN UNDER A SLACKER GRADIENT CLOSER TO THE LO PRES. ADDED A MENTION OF WATERSPOUTS OVER THE EASTERN PORTION OF THE LAKE WHERE WATER TEMPERATURES ARE WARMEST AND WINDS MAY BE WEAKER FOR A TIME TODAY AHEAD OF AN APPROACHING LO PRES TROUGH MOVING AROUND THE LO JUST TO THE N. AS THE LO CONTINUES E OF LAKE SUPERIOR TONIGHT/TUE...NW GALES TO 35 KTS WILL BE POSSIBLE OVER MAINLY THE CENTRAL PORTION OF THE LAKE WHERE GUIDANCE HINTS THE PRES GRADIENT WILL BE SHARPEST. AS THE LO MOVES FARTHER TO THE E AND HI PRES TO THE W APPROACHES...THE PRES GRADIENT AND WINDS WILL DIMINISH W-E ON TUE NIGHT/WED. WINDS WILL BE UNDER 20 KTS FOR WED NIGHT THRU FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLB AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
126 AM EDT TUE AUG 25 2015 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL CROSS THE AREA FROM TODAY THROUGH TUESDAY BRINGING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS. AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE OVER THE GREAT LAKES REGION THROUGH MID WEEK, AND PROVIDE FOR UNSETTLED WEATHER IN THE NORTHEAST. LATER IN THE WEEK THE UPPER LEVEL LOW WILL MAKE ITS MOVE EAST, CONTINUING THE CHANCES FOR RAIN. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1006 PM EDT MONDAY...EARLIER STRONG THUNDERSTORM WHICH DEVELOPED VICINITY OF NEWCOMB NY HAS WEAKENED A BIT, BUT IS NOW OVER THE NY SIDE OF CHAMPLAIN VALLEY NEAR PLATTSBURGH. STILL A GOOD AMOUNT OF LIGHTNING OCCURRING DESPITE SCANT INSTABILITY AND IS PRODUCING LOCALIZED OUTFLOW (NORTHERLY GUSTS TO 21 KNOTS RECENTLY OBSERVED AT BTV AIRPORT). THAT ONGOING THUNDERSTORM WILL CONTINUE TO LIFT NORTHWARD INTO CANADA WITHIN THE NEXT HOUR OR SO, WITH REMNANT SHOWERS SPREADING INTO THE VT SIDE OF THE CHAMPLAIN VALLEY. MEANWHILE, ADDITIONAL SHOWERS AND ISOLATED STORMS ARE EVIDENT IN COMPOSITE RADAR IMAGERY FROM ALBANY TO EAST OF BINGHAMTON NY. LATEST HRRR CONTINUES TO SUGGEST THAT THIS RENEWED DEVELOPMENT WILL SPREAD NORTH-NORTHEAST INTO SOUTHERN VT AND SOUTHERN CHAMPLAIN VALLEY REGION THROUGH OVERNIGHT AS THE FRONT SLOWS/STALLS. POPS STILL GENERALLY ON TRACK, SO NO CHANGES TO POPS OR WX WITH THIS UPDATE. UPDATED THE FORECAST WITH CURRENT OBSERVATIONAL DATA. LOWS 50S TO MID 60S, WARMEST IN VT WITH GREATER CLOUD COVER. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... AS OF 358 PM EDT MONDAY... THE FRONT REMAINS IN EASTERN VERMONT TUESDAY BEFORE EVENTUALLY MOVING EAST INTO NH TUESDAY AFTERNOON. MODELS INDICATING THERE WILL STILL BE SOME INSTABILITY OF 500-1000 J/KG CAPE EAST OF THE GREEN MOUNTAINS SO KEEPING SHOWERS AND THUNDERSTORMS IN THE FORECAST THERE DECREASING TO A SLIGHT CHANCE FURTHER WEST. HIGHS MAINLY IN THE 70S TO NEAR 80. THE FRONT PUSHES EAST OF THE REGION TUESDAY NIGHT BUT THERE MAY BE SOME LAKE EFFECT RAIN SHOWERS DEVELOPING OVER LAKE ONTARIO AS COOLER AIR MOVES OVER THE WARM WATERS OF THE LAKE. THESE SHOWERS WILL BE MAINLY IN SOUTHERN AND WESTERN ST. LAWRENCE COUNTY AND WESTERN ADIRONDACKS. LOW TEMPS MAINLY IN THE 50S. COOLER WEATHER EXPECTED WEDNESDAY AND WEDNESDAY NIGHT WITH CYCLONIC FLOW AND COOL AIR ALOFT. THERE IS ALSO A CHANCE OF SHOWERS OR SPRINKLES ACROSS THE NORTH WITH A LITTLE BIT OF INSTABILITY IN THE AFTERNOON AND EVENING. HIGHS IN THE 70S. LOWS IN THE 50S. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 405 PM EDT MONDAY...ECMWF AND GFS MODELS IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. AN UPPER TROUGH WILL MOVE ACROSS THE REGION ON THURSDAY...SO HAVE CONTINUED TO CARRY CHANCE POPS FOR SHOWERS ON THURSDAY. A RIDGE OF HIGH PRESSURE WILL BUILD NORTHEAST FROM THE OHIO VALLEY THURSDAY NIGHT. THIS RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SUNDAY. THUS...HAVE GONE WITH A DRY FORECAST FROM THURSDAY NIGHT THROUGH SUNDAY NIGHT. ON MONDAY...ECMWF AND GFS MODELS SHOW SOME DIFFERENCES WITH THE ECMWF SHOWING A BUILDING UPPER RIDGE AND CONTINUED DRY WEATHER. THE GFS MODEL ON MONDAY SHOWING WESTERLIES OVER THE REGION ALONG WITH A SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS. FORECASTER CONFIDENCE IS LOW FOR MONDAY...SO HAVE JUST GONE WITH SUPER-BLEND SLIGHT CHANCE POPS ON MONDAY. && .AVIATION /05Z TUESDAY THROUGH SATURDAY/... THROUGH 06Z WEDNESDAY...ISOLATED SHOWERS, AND AN OCCASIONAL EMBEDDED THUNDERSTORM, CONTINUE TO EMERGE ALONG SLOW MOVING COLD FRONT DRAPED ACROSS CENTRAL VERMONT INTO THE UPPER HUDSON VALLEY AND CATSKILLS. BEST CHANCES FOR SHOWERS TO AFFECT TERMINALS AT KMPV AND KRUT. ANY IMPACTS WILL BE BRIEF AT THE TERMINALS. GENERALLY LOOKING AT VFR CONDITIONS OUTSIDE OF SHOWER/TSTM ACTIVITY. MOSTLY CLOUDY SKIES AT 040-080 SHOULD PRECLUDE FOG FORMATION, WITH EXCEPTION OF BRIEF CLEARING AT KSLK WITH INTERMITTENT MVFR VISIBILITIES EARLY THIS MORNING. MORE ISOLATED SHOWERS/TSTMS DEVELOPMENT EXPECTED DURING THE DAY TUESDAY, MAINLY ACROSS ERN VT AND EXPECTED TO AFFECT KMPV AND POSSIBLY KRUT. WINDS GENERALLY LIGHT SW 5-8 KTS. AFTER SUNSET...WINDS WILL BECOME LIGHT AND VRB AT LESS THAN 5KTS WITH SOME CLEARING SETTLING IN INTO THE EVENING AS SHOWERS EXPECTED TO DIMINISH IN COVERAGE. OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY... 06Z WEDNESDAY THROUGH 00Z FRIDAY...MAINLY VFR WITH BRIEF MVFR IN SHOWERS WITH SLOW MOVING FRONT AND UPPER LOW OVER CANADA IN THE VICINITY. COVERAGE OF ACTIVITY SHOULD BE MOST FOCUSED DURING THE AFTERNOON AND EARLY EVENING HOURS EACH DAY. 00Z FRIDAY THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED UNDER A RIDGE OF HIGH PRESSURE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...LOCONTO/SISSON SHORT TERM...SISSON LONG TERM...WGH AVIATION...KGM
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
344 AM EDT TUE AUG 25 2015 .SYNOPSIS... A SERIES OF TROUGHS OF LOW PRESSURE WILL ROTATE SOUTHEAST ACROSS LAKE ERIE INTO WEDNESDAY THEN HIGH PRESSURE WILL MOVE EAST ACROSS THE REGION THURSDAY INTO SATURDAY THEN SETTLE OVER VIRGINIA INTO EARLY NEXT WEEK. WEAK LOW PRESSURE SHOULD MOVE UP THE LOWER OHIO VALLEY SUNDAY INTO MONDAY AND DISSIPATE. && .NEAR TERM /UNTIL 6 PM TUESDAY EVENING/... THE FIRST IN A SERIES OF WEAK TROUGHS IS MOVING SE ACROSS THE AREA WITH ANOTHER EXPECTED TO BE NEAR LAKE ERIE BY 00Z THIS EVENING. 850 MB TEMPS WILL STAY COOL ENOUGH TODAY TO ALLOW FOR SOME LAKE EFFECT SHRA. THE TROUGHS WILL ACT A FOCUSING MECHANISMS FOR MORE CONCENTRATED BANDS OF SHRA. THE ONLY MODEL THAT SHOW ANY RAIN OUTSIDE OF THE SNOWBELT AREA IS THE HRRR BUT THATS NOT UNEXPECTED SINCE THE HRRR CAN GENERATE PRECIP FROM ANY PARTLY CLOUDY SITUATION. CURRENT FORECAST POPS LOOK REASONABLE SO LITTLE TO CHANGE. MORE WIDESPREAD CLOUDS TODAY WILL ONLY ALLOW HIGHS TO GET BACK INTO A 67 TO 72 DEGREE RANGE WITH THE COOLER READINGS IN THE EAST PART OF THE SNOWBELT. && .SHORT TERM /6 PM TUESDAY THROUGH FRIDAY NIGHT/... THE NEXT WEAK TROUGH SHOULD DROP SE ACROSS THE CWA TONIGHT. BETTER MOISTURE WILL BE IN PLACE IN THE LOWER LEVELS SO THE THREAT FOR LIGHT SHRA/SPRINKLE SHOULD SPREAD OUT A LITTLE MORE OUTSIDE OF THE SNOWBELT AND THIS WILL REMAIN THE CASE THRU WED AS THE AXIS OF THE UPPER TROUGH MOVES SE ACROSS THE CWA. WITH SUNSET WED EVE...THE THREAT FOR SHRA SHOULD RETREAT INTO THE EASTERN PART OF THE SNOWBELT AND CONTINUE TO SHRINK THRU THU AS HIGH PRESSURE FINALLY MOVES OVER THE AREA. THE HIGH SHOULD PROVIDE DRY CONDITIONS THU NIGHT THRU FRI NIGHT. TEMPS WILL CONTINUE BELOW NORMAL THRU THU NIGHT THEN START TO MODERATE CLOSER TO NORMAL ON FRI IN RESPONSE TO ABUNDANT SUNSHINE AND WINDS BECOMING LIGHT SE. && .LONG TERM /SATURDAY THROUGH MONDAY/... HEIGHTS ARE PROGGED TO RISE ACROSS THE EASTERN HALF OF THE COUNTRY LATE IN THE WEEK INTO NEXT WEEK. THE FLY IN THE OINTMENT IS AN UPPER TROUGH THAT IS PROGGED TO DRIFT ACROSS THE MIDWEST AND LOWER GREAT LAKES. THE MODELS HAVE BEEN RELATIVELY CONSISTENT WITH THIS FEATURE. THE SURFACE PROGS ON THE MODELS LOOK AS THOUGH A WEAK COLD FRONT WILL DROP ACROSS ONTARIO AND NEW ENGLAND WHILE A WARM FRONT DEVELOPS OVER THE OHIO VALLEY. THE ATMOSPHERE WILL START OUT QUITE STABLE AND DRY AND IT MAY TAKE A WHILE TO MOISTEN THINGS UP. WILL CONTINUE TO FORECAST A SLIGHT CHANCE FOR SHOWERS/STORMS ACROSS NORTHWEST OHIO ON SATURDAY WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE FORECAST AREA ON SUNDAY. NOT SURE IF THE SYSTEM WILL BE GONE ON MONDAY OR NOT. TEMPERATURES WILL RECOVER AS THE RIDGE BUILDS ALOFT. TEMPERATURES MAY BE SUPPRESSED SOMEWHAT ON SATURDAY AND SUNDAY DEPENDING ON THE AMOUNT OF CLOUDS AND SHOWERS BUT THE TREND WILL BE UPWARD. HIGHS SHOULD BE ABOVE NORMAL THIS WEEKEND AND ESPECIALLY INTO NEXT WEEK. SUMMER IS NOT OVER YET. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... TROUGH OF LOW PRESSURE WILL DROP ACROSS LAKE ERIE EARLY THIS MORNING WITH A FEW SHOWERS. MOST AREAS WILL LIKELY NOT SEE MUCH MORE THAN A SPRINKLE EXCEPT ACROSS EXTREME NORTHEAST OH AND NORTHWEST PA WHERE THERE MAY BE A BRIEF MVFR VISIBILITY DURING THE HEAVIER SHOWERS. COLD ENOUGH ALOFT FOR LAKE EFFECT CLOUDS TODAY. A FEW LAKE EFFECT SHOWERS COULD LINGER EXTREME NE OH/NW PA ANYTIME TODAY BUT THE SHOWERS WILL BE MORE LIKELY AGAIN EARLY TONIGHT (TUE NIGHT) AS THE NEXT SURFACE TROUGH DROPS ACROSS LAKE ERIE IN THE NORTHWEST FLOW. OUTLOOK...NON VFR POSSIBLE EXTREME NORTHEAST OH AND NORTHWEST PA WEDNESDAY INTO THURSDAY MORNING. && .MARINE... JUST ENOUGH WIND IS LIKELY ON LAKE ERIE TODAY TO KEEP THE SMALL CRAFT ADVISORY IN EFFECT FROM THE ISLANDS EAST. THE GRADIENT WILL GRADUALLY WEAKEN TODAY BUT THE FAVORABLE WIND DIRECTION FROM THE WEST SOUTHWEST AND THE COLD ADVECTION SHOULD BE ENOUGH TO KEEP THE WAVES UP AROUND 3 TO 4 FEET MUCH OF THE DAY ON THE CENTRAL AND EASTERN BASIN. THE NEXT TROUGH OF LOW PRESSURE WILL SWING THROUGH TONIGHT. THE WIND MAY INCREASE FOR A COUPLE OF HOURS WITH THE PASSAGE OF THE TROUGH BUT THE OVERALL WIND SPEEDS MAY NOT BE STRONG ENOUGH FOR ENOUGH DURATION FOR A SMALL CRAFT ADVISORY. IT WILL BE CLOSE THOUGH AND SMALL CRAFT OPERATORS SHOULD MONITOR THE FORECAST AND THE WEATHER. A WATERSPOUT IS POSSIBLE JUST ABOUT ANYTIME INTO THURSDAY MORNING BUT ESPECIALLY THIS MORNING AND AGAIN TONIGHT WITH THE PASSAGE OF THE TROUGH. HIGH PRESSURE WILL BUILD EAST ACROSS THE LOWER LAKES BY THURSDAY AND WINDS SHOULD DIMINISH FROM WEST TO EAST AND VEER MORE NORTHERLY. THE FLOW SHOULD COME AROUND FROM THE SOUTH BY FRIDAY AS THE HIGH SHIFTS EAST. HIGH PRESSURE TO THE NORTH OF LAKE ERIE COULD CAUSE A LIGHT EAST TO NORTHEAST FLOW TO DEVELOP FOR A WHILE THIS WEEKEND BUT WIND SPEEDS SHOULD BE RELATIVELY LIGHT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LEZ144>149. SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LEZ142-143. && $$ SYNOPSIS...ADAMS NEAR TERM...ADAMS SHORT TERM...ADAMS LONG TERM...KOSARIK AVIATION...KOSARIK MARINE...KOSARIK
AREA FORECAST DISCUSSION...COR
NWS HOUSTON/GALVESTON TX
442 AM CDT TUE AUG 25 2015 .DISCUSSION... NORTHWESTERN FLOW PATTERN SET UP OVER TEXAS WITH THE 5H RIDGE CENTERED OVER THE FOUR CORNERS REGION. ENERGY OVER THE RED RIVER VALLEY SLIDING DOWN WITHIN THIS FLOW IS BEGINNING TO FIRE EARLY MORNING CONVECTION JUST SOUTH OF THE RIVER IN EXTREME NORTHEASTERN STATE. A WEAK COLD FRONT...OR AN OUTFLOW BOUNDARY PROPAGATING FROM NORTHEASTERN CONVECTION...WILL BE ENTERING OUR HEATED AND STILL VERY MOIST ENVIRONMENT (~2 INCH PWS) FROM LATE MORNING ONWARD. THE PROGGED BACKGROUND THERMODYNAMICS ARE RIPE ENOUGH TO SUPPORT STRONG...TO BORDERLINE SEVERE...AFTERNOON THUNDERSTORMS WITH THE INVERTED-V NATURE TO SOUNDINGS INDICATIVE OF A WIND THREAT. ALTHOUGH OF NOT MUCH USE OF LATE...SHORT TERM HIGH RESOLUTION MODELING THAT HAS INITIALIZED SOMEWHAT DECENTLY THIS MORNING ...SUCH AS THE HRRR AND NAM12 TO SOME DEGREE...DEVELOP MID- AFTERNOON CONVECTION OVER THE NORTHWESTERN CWA AND SWATH STORM CLUSTERS NORTHEAST TO SOUTHWEST DOWN ACROSS THE MAJORITY OF THE CWA THROUGH THE AFTERNOON INTO EARLY EVENING HOURS. CONSIDERING WE ARE WITHIN AN UNWORKED OVER...UNSTABLE AIR MASS WITH AN APPROACHING BOUNDARY REACHING OUR DOORSTEP DURING THE BEST HEAT-OF-THE DAY TIME FRAME POSSIBLY INTERACTING WITH A NORTHERN ADVANCING SEA BREEZE...WILL GO AHEAD AND TAKE THE BAIT WITH THE ABOVE SCENARIO AND TAKE POPS UP TO MODERATE CHANCE. REGION REMAINS WITHIN THIS NORTHERN FLOW PATTERN AT MID-WEEK WITH THE COOLEST MID-LEVEL AIR TO HOLD OFF FROM ADVECTING IN UNTIL LATE WEDNESDAY...OR ONCE WINDS VEER MORE AROUND TO THE EAST. ONCE THIS EVENING`S PRECIPITATION WANES...THE NEXT SEVERAL DAYS WILL REMAIN DRY PER THE SLOW EASTERN MOVEMENT OF THE WESTERN RIDGE ASSERTING ITS SUBSIDENT INFLUENCE OVER THE STATE THROUGH SATURDAY. MOSTLY SUNNY TO PARTLY CLOUDY SKIES WITH RETURN FLOW LATE IN THE WORK WEEK WILL SPELL SUBSEQUENT DAILY HOT CONDITIONS. LESSENED HUMIDITY WITH THE ADVECTION OF A MUCH DRIER NORTHEASTERN AIR MASS THAT WILL BE CERTAINLY FELT IN THE EARLY THURSDAY AND FRIDAY MORNING HOURS...OVERNIGHT SURFACE TEMPERATURES WILL FALL INTO THE AVERAGE MID TO UPPER 60S WITH LOW 60S IN THE NOTORIOUS COOL SPOTS. DRY AIR WILL MAKE FOR INTERIOR AFTERNOON HEAT IN THE MID TO UPPER 90S WITH HEAT INDICES STICKING CLOSE TO AMBIENT TEMPERATURES AND ARE NOT FORECAST TO REACH THE CENTURY MARK THROUGH EARLY NEXT WEEK. SOUTHERN FORECAST AREA RAIN CHANCES WILL BEGIN TO CLIMB FROM SUNDAY ONWARD AS A MISSISSIPPI VALLEY TROUGH DOWNSTREAM OF DESERT SW RIDGING BEGINS TO SCOOT A BIT WEST AND TAP INTO A RELATIVELY HIGHER NEAR 1.5 INCH AIR MASS. 31 && .MARINE... LIGHT WINDS AND LOW SEAS SHOULD MOSTLY REMAIN IN PLACE THE NEXT COUPLE OF DAYS. A WEAK FRONTAL BOUNDARY POSITIONED IN EAST TEXAS AND LOUISIANA...ALONG WITH THE SEA BREEZE...COULD PROVIDE A FOCUS FOR SCT TSTMS TODAY. WINDS/SEAS HIGHER IN AND NEAR STORMS. THE FRONT SHOULD PUSH INTO THE WATERS TONIGHT WITH ENE WINDS IN ITS WAKE. WINDS WILL GRADUALLY VEER TO THE SE THURS NIGHT AND CONTINUE INTO THE WEEKEND. 47 && .AVIATION... SOMEWHAT OF A LOW CONFIDENCE FCST GIVEN WIDE VARIETY OF GUIDANCE. MAIN FCST ISSUE WILL BE TSTM POTENTIAL. WILL NEED TO KEEP AN EYE ON TSTMS CURRENTLY DEVELOPING IN N/NE TX AS THESE COULD EXPAND SSE ALONG A WEAK FRONTAL BOUNDARY STRETCHED ACROSS E TX/LA WITH DAYTIME HEATING...EVENTUALLY SAGGING INTO SE TX. CONVECTIVE TEMPS SOMEWHERE BETWEEN 92-95 & THINK MAIN THREAT PERIOD FOR AREA TAFS WILL BE 18-24Z. ATMOS PROFILE SUGGESTS STRONG WINDS POSSIBLE IN THE MORE SIGNIFICANT CELLS. METRO AIRPORTS WILL ALSO NEED TO KEEP AN EYE ON SEA BREEZE POSITION...AS POTENTIAL COLLISIONS BETWEEN INCOMING STORMS AND THIS FEATURE AND/OR ASSOCIATED PRECIP WILL FURTHER ENHANCE STORM STRENGTH. DUE TO UNCERTAINTY - WILL LIKELY KEEP THE VCTS`S GOING IN THE 12Z PACKAGE AND AMEND WHEN NEEDED. OUTSIDE ANY TSTMS...ANTICIPATE MOSTLY VFR CONDITIONS. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 98 74 95 68 98 / 40 20 10 10 0 HOUSTON (IAH) 98 74 95 69 96 / 40 20 10 10 0 GALVESTON (GLS) 91 81 90 78 92 / 30 20 10 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...31/47
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1138 PM CDT MON AUG 24 2015 .AVIATION... /06Z TAFS/ Thunderstorms south of San Angelo were rapidly weakening at 0430Z and should dissipate by 6Z. Isolated to scattered showers and thunderstorms are again possible Tuesday afternoon and evening, and added VCTS to all West Central Texas terminals. Strong winds in excess of 40 KTS and IFR visibilities in heavy rain are possible if a strong storm moves over a terminal. Outside of the thunderstorms VFR conditions expected with wind speeds less than 10 KTS. && .PREV DISCUSSION... /ISSUED 619 PM CDT MON AUG 24 2015/ AVIATION... /00Z TAFS/ A thunderstorm outflow boundary approaching KABI from the east will bring east wind gusts to 18 KTS 00Z to 1Z. Also added VCTS to KABI as a few storms may develop off the outflow boundary. Isolated to scattered thunderstorms possible again Tuesday afternoon...as a secondary weak cold front moves into the region. Will leave mention of storms out of terminals at this time, but coverage may become high enough for mention of VCTS. PREV DISCUSSION... /ISSUED 329 PM CDT MON AUG 24 2015/ SHORT TERM... (Tonight and Tuesday) A weak cold front is stalled generally along a line from near Barnhart...to Eldorado...to Brady. A cumulus field has developed this afternoon in the vicinity of the front. The HRRR continues to depict isolated to scattered shower and thunderstorm activity in the vicinity of the boundary this afternoon and early evening. Uncertainty remains on the extent of convection this afternoon, but slight chance PoPs were kept for much of the area, with the best chance across the southern two thirds of the area. Locally heavy rainfall will be possible, as very slow movement is expected. In addition, isolated downbursts will be possible. Most of the convection is expected to dissipate shortly after sunset, with the loss of daytime heating. Overnight lows will generally be in the 70s, although a few locations may drop into the upper 60s. Models continue to indicate an upper level disturbance moving across the area Tuesday in the north flow aloft. This in combination with what is left of the dissipating cold front will result in isolated to scattered showers and thunderstorms Tuesday afternoon, with the best chance across the eastern half of the region. Highs will generally be in the mid to upper 90s. Daniels LONG TERM... (Tuesday night through next Monday) The extended portion of the forecast will be mainly dry, and continued hot with temperatures averaging 5 or more degrees above normal through next weekend. Decided to keep slight chance PoPs going through Tuesday evening as a weak front continues to ease southward. The best chances by Tuesday evening should be generally south of a San Saba to Eldorado line where the front is expected to move to by the evening hours. Once again, if these storms develop, the main hazards will be gusty winds, and dangerous lightning. Have also kept very low end slight chance PoPs Wednesday afternoon and early evening as remnant outflow boundaries possibly left behind by Tuesday`s activity could result in isolated showers or storms Wednesday afternoon. From Thursday through the weekend, the upper level ridge over the southwestern U. S. will keep our weather hot and dry. Have nudged afternoon highs up a degree or two for the second half of the week as the ridge takes control, allowing the atmosphere to warm. Another cold front could possibly move into the area next weekend, but models show it struggling to make progress southward after reaching west central Texas, so will just trend temperatures downward a couple degrees next weekend into Monday for now. 20 && .PRELIMINARY POINT TEMPS/POPS... Abilene 72 95 72 97 / 10 20 10 5 San Angelo 72 98 71 100 / 20 20 10 10 Junction 71 97 70 98 / 20 30 20 20 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ 99/99/04
AREA FORECAST DISCUSSION
NWS ALBANY NY
808 AM EDT TUE AUG 25 2015 .SYNOPSIS... A COLD FRONT OVER THE MOHAWK VALLEY THIS MORNING WILL DRIFT SLOWLY EAST TODAY ACROSS THE ALBANY FORECAST AREA...RESULTING IN SCATTERED SHOWERS AND THUNDERSTORMS. A LARGE MID LEVEL WEATHER DISTURBANCE WILL MOVE FROM THE UPPER GREAT LAKES INTO NORTHERN QUEBEC OVER THE NEXT FEW DAYS. IT WILL USHER COOLER LESS HUMID AIR INTO THE REGION WEDNESDAY AND THURSDAY AS WELL AS SCATTERED MAINLY AFTERNOON SHOWERS NORTH AND WEST OF THE CAPITAL DISTRICT. THURSDAY NIGHT INTO WEEKS END HIGH PRESSURE WILL BUILD INTO OUR REGION WITH MAINLY FAIR WEATHER AND SEASONABLE TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... AS OF 808 AM EDT...AREA OF HEAVY SHOWERS AND THUNDERSTORMS MOVING FROM BERKSHIRE COUNTY MA NORTHEAST THROUGH SOUTHERN VERMONT. KPSF REPORTED 0.41 INCHES OF RAIN IN ONE HOUR...AND SOME AREAS MAY HAVE SEEN AN INCH IN AN HOUR BASED ON RADAR ESTIMATES. RADAR IS ESTIMATING UP TO 2 INCHES OF RAIN SO FAR IN SOME LOCATIONS SO HAVE ISSUED A FLOOD ADVISORY FOR AREAS WITH HEAVY RAIN FOR MINOR FLOODING. LOOKING AT CURRENT DEWPOINTS...THE SURFACE COLD FRONT HAS MADE PROGRESS THROUGH BURLINGTON VERMONT...ROME NEW YORK AND MAYBE AS FAR EAST AS BINGHAMTON NY. 850 FRONT LOOKS TO LIE ALONG SIMILAR LINE BASED ON CURRENT RAP ANALYSIS. ANYWHERE EAST OF THAT LINE HAS A SHOT FOR SHOWERS AND THUNDERSTORMS TODAY DUE TO SUNS HEATING A MODERATELY STRONG FRONTOGENETICAL FORCING FROM COLD FRONT. FURTHER WEST...DRIER AIR SHOULD KEEP THESE AREAS DRY FROM THE MOHAWK VALLEY NORTH AND WEST. TEMPERATURES RANGED FROM THE LOW 50S BEHIND THE PASSING FRONT IN OUR WESTERN AREAS TO LOW 70S FAR SOUTHEAST...OUT AHEAD OF THE FRONT. A 70 KNOT JET STREAK SW TO NE OVER CENTRAL NEW YORK THIS MORNING MOVES TO LONG ISLAND BY 22Z TUESDAY LOOKS TO PLACE EASTERN PART OF OUR FORECAST AREA IN A FAVORABLE AREA FOR SOME UPPER LEVEL DIVERGENCE. LOCAL MODELS STILL SHOW SOME CONVECTION INITIATION BY TUESDAY AFTERNOON...SOME STORMS THAT DO DEVELOP COULD BE STRONG TO ISOLATED SEVERE RIGHT ALONG THE FRONT WHERE THE BEST SUPPORT FOR THUNDERSTORM LIFT WILL BE. THE STORM PREDICTION CENTER HAS MARGINAL FOR SEVERE THUNDERSTORMS TO THE EAST OF THE HUDSON VALLEY. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER AND MID 70S NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION TO UPPER 70S AND LOWER 80S FROM THE CAPITAL REGION POINTS SOUTH AND EAST. FOR TONIGHT...SLIGHTLY COOLER AND DRIER AIR SHOULD WORK INTO THE REGION. STILL HAVE SOME LOW/SLIGHT CHANCE POPS INTO EARLY EVENING TO THE EAST OF THE HUDSON VALLEY...BUT THEN IT LOOKS DRY EVERYWHERE LATER TONIGHT WITH A CLEAR TO PARTLY CLOUDY SKY. TEMPERATURES WILL DIP BACK INTO THE 50S EVERYWHERE. THERE MIGHT BE SOME PATCHY VALLEY FOG BUT A BREEZE MIGHT BE ENOUGH TO PREVENT THAT UNLESS THOSE AREAS RECEIVE A FAIR AMOUNT OF RAINFALL TODAY. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... MODELS SUITE (GEM/GFS/ECMWF/NAM) IS LARGELY IN AGREEMENT OVER FLA DURING THIS PERIOD. 500HPA CUT OFF OPENS INTO A PROGRESSIVE TROF TO OUR NORTH NR JAMES BAY WED...AND DRAGS THE TROF AXIS ACROSS THE RAN WED INTO THU. AT THE SFC HIGH PRESSURE BUILDS IN THE WAKE OF THIS TROF OVER THE GRTLKS...AND SURGES EAST INTO NY/NEW ENG LATE THU INTO FRI. MUCH OF WED FLA IS IN DRY SLOT ON SE QUADRANT OF CUTOFF SYSTEM...FR DIURNAL HEATING...COOLING ALOFT PARTICULARLY N & W OF ALB ALONG WITH ELEVATED TURN WILL RESULT IN SCT AFTN -SHRA WED OVER THE ADIRONDACKS...AND ISOLD -SHRA N & W OF ALBANY THU AS THE TROF MOVES THROUGH. DIURNALLY DRIVEN SCT-BKN CU WILL BE THE RULE DURING THE DAYLIGHT HOURS WITH GENERALLY SCT CLOUDS AT NIGHT. OTHERWISE A MOSTLY FAIR PERIOD WITH COMFORTABLE HUMIDITY AND TEMPS TRENDING NR TO SLIGHTLY LO NORMALS. THU NT INTO FRI WILL SEE RISING 500 HPA GUTS AND BUILDING SFC HIGH PRESSURE OVER THE NE. SKIES WILL CLEAR THU ENG...AND WITH LARGE SCALE SUBSIDENCE FRI WILL BE MOSTLY SUNNY WITH LOW HUMIDITY AND UMPS NR NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THE MODELS MORE OR LESS AGREE ON THE BIG PICTURE...OF RISING 500HPA GUTS AS LARGE 500 HPA RIDGE BUILDS OVER THE EASTERN US BY THE END OF THE PERIOD. AT THE SFC HIGH PRESSURE RESIDES OVER THE EASTERN SEABOARD...WHOSE CENTER SHIFTS SLIGHTLY. WPC/ECMWF/GEM ARE PRETTY MUCH DRY ACROSS THE FLA THRU THIS PERIOD...THE GFS HAS A SHEARING SHORT WV ME ACROSS THE NE WITH A SUGGESTION OF SCT CONVECTION SAT AND SUN AS WELL AS MORE CLOUDS. NUMEROUS GFS ENSEMBLE MEMBERS PRODUCE THE BULK OF THIS QPF SAT NT. SO THERES BEEN SOME SIGNAL ABOUT THIS SHORT WV FOR SEVERAL RUNS...ALTHOUGH PLACEMENT AND RESPONSE HAS VARIED...ITS WORTH MENTIONING CHC OF AFTN ENG TSTM SAT WHERE THE SIGNAL IS STRONGEST. ODOR IT WILL BE A DRY WARM LATE SUMMER PERIOD WITH TEMPS RUNNING 3-5 DEG ABS NORMALS...WITH A CONTINUED SIGNAL FM THE MODELS SUITE AND 8-14 DAY OUTLOOKS FOR BUILDING WARMTH INTO THE LABOR DAY WEEKEND. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... A SLOW MOVING COLD FRONT CONTINUES TO PRODUCE SCATTERED SHOWERS/THUNDERSTORMS EAST OF THE HUDSON RIVER. DUE TO ASOS PROBLEMS WILL CONTINUE WITH AID NOT ASKED AT KGFL. LOOK FOR BRIEF TIMES OF MVFR AND EVEN IFR...ESPECIALLY AT KPOU AND KPSF THROUGH ABOUT 14Z. OTHERWISE IT WILL BE MAINLY VFR CONDITIONS TODAY WITH THE LOWER CLOUDS DISSIPATING BY 14Z OR SO. WE WILL BE LEFT WITH SCT-BKN CU BASES WELL OVER 3000 FEET. HOWEVER...WE WILL CONTINUE WITH VCSH THROUGH SUNSET AS THERE IS A CHANCE MORE THUNDERSTORMS WILL DEVELOP...ESPECIALLY AT FROM HUDSON VALLEY EAST. ANY OF THESE STORMS COULD BE LOCALLY STRONG TO SEVERE AGAIN EAST OF THE HUDSON VALLEY. THE WIND WILL BECOME WESTERLY WITH TIME TODAY...5-10 MPH. TONIGHT...WILL BE DRY WITH A CLEAR TO PARTLY CLOUDY SKY. SOME FOG MIGHT DEVELOP IN THE USUAL SPOTS...MAINLY KGFL AND KPSF. FOR NOW...WILL INCLUDE SOME IFR FOG IN THOSE PLACES. OUTLOOK... WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. THURSDAY NIGHT-FRI NT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. SATURDAY NIGHT-SUN: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A COLD FRONT OVER THE HUDSON VALLEY THIS MORNING WILL DRIFT SLOWLY EAST REACHING THE NEW ENGLAND COAST OVERNIGHT...RESULTING IN SCATTERED SHOWERS AND THUNDERSTORMS TODAY. A LARGE MID LEVEL WEATHER DISTURBANCE WILL MOVE FROM THE UPPER GREAT LAKES INTO NORTHERN QUEBEC OVER THE NEXT FEW DAYS. IT WILL USHER COOLER LESS HUMID AIR INTO THE REGION WEDNESDAY AND THURSDAY AS WELL AS SCATTERED MAINLY AFTERNOON SHOWERS NORTH AND WEST OF THE CAPITAL DISTRICT. THURSDAY NIGHT INTO WEEKS END HIGH PRESSURE WILL BUILD INTO OUR REGION WITH MAINLY FAIR WEATHER AND WARMING TEMPERATURES. RH VALUES WILL BE FROM 80 TO NEAR 100 DURING THE OVERNIGHT HOURS AND FROM 50 TO 60 THIS AFTERNOON AND 45 TO 55 WEDNESDAY AFTERNOON. WINDS WILL BE LIGHT AND VARIABLE TODAY AND TONIGHT BECOMING WEST AROUND 10 MPH WEDNESDAY. && .HYDROLOGY... NO HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH MONDAY. SCATTERED SHOWERS AND STORMS ARE EXPECTED TODAY. OTHER THAN SOME SCATTERED LIGHT SHOWERS IN THE ADIRONDACKS WEDNESDAY AND THURSDAY AFTERNOON IT WILL BE MAINLY DRY. THE ENTIRE REGION WILL RECEIVE UNDER A HALF AN INCH OF RAINFALL THROUGH SATURDAY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SND/SNYDER NEAR TERM...SND/HWJIV SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...SND/HWJIV FIRE WEATHER...SNYDER HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
658 AM EDT TUE AUG 25 2015 .SYNOPSIS... A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TODAY AS IT STALLS IN EASTERN NEW YORK. THE FRONT CROSSES SOUTHERN NEW ENGLAND TONIGHT MOVING OFFSHORE WEDNESDAY. MAINLY DRY AND SEASONABLE WEATHER WITH COMFORTABLE HUMIDITY LEVELS IS EXPECTED WEDNESDAY THROUGH SATURDAY. HUMIDITY AND ABOVE AVERAGE TEMPS RETURN FOR THE BEGINNING OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... *** A FEW STRONG TO SEVERE THUNDERSTORMS POSSIBLE IN INTERIOR SNE TODAY *** 700 AM UPDATE... COLD FRONT IS STILL SITUATED WELL OUT BY BGM THIS MORNING AND WILL SLOWLY MOVE EASTWARD TODAY. OTHERWISE A BATCH OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED ACROSS THE BERKSHIRES AND WILL MOVE NORTHEAST INTO NEW HAMPSHIRE. CAPE VALUES HAVE STARTED TO INCREASE ACROSS THE CT VALLEY AND WITH K VALUES WELL ABOVE 34 ANTICIPATE THUNDERSTORMS TO CONTINUE TO DEVELOP...IE BACK BUILD FROM CURRENT CONVECTION. IN FACT THE LATEST HRRR KEEPS PRECIP GOING ACROSS THE WESTERN PORTION OF THE CWA OVER THE NEXT FEW HOURS. ALTHOUGH PWATS ARE AROUND 1.5 INCHES...IF THESE STORMS BACKBUILD...COULD SEE FLOODING ISSUES. CURRENTLY THE STORMS ACROSS FRANKLIN AND HAMPSHIRE COUNTY IS SHOWING OVER 2 INCHES HAS FALLEN WITHIN AN HOUR! INSTABILITY IS PROGGED TO INCREASE OVER THE NEXT FEW HOURS SO ANTICIPATE STRONG TO SEVERE STORM POTENTIAL CLOSER TO 10-11 AM AND LAST THROUGH MUCH OF THE DAY. PREVIOUS DISCUSSION... TODAY...CLOSED UPPER LOW S OF JAMES BAY WITH MEAN TROF ACROSS GT LAKES AND SW CYCLONIC FLOW ACROSS NEW ENG. SFC COLD FRONT EXPECTED TO STALL INVOF HUDSON VALLEY AS IT IS PARALLEL TO UPPER FLOW. MAIN CONCERN FOR TODAY IS THE POTENTIAL FOR STRONG TO SEVERE TSTMS. MODELS SHOW A RAPID INCREASE IN INSTABILITY AFTER 12Z WITH CAPES 1000-2000 J/KG DEVELOPING...FOCUSED ACROSS THE INTERIOR. 0-6KM SHEAR INCREASES TO 35-40 KT SO EXPECT A FEW STRONG TO SEVERE TSTMS TO DEVELOP WITH POTENTIAL FOR ORGANIZED SEVERE WEATHER AND POSSIBLY A FEW SUPERCELLS GIVEN MAGNITUDE OF SHEAR/INSTABILITY. 0-1KM HELICITY IS NOT IMPRESSIVE BUT UPPER LEVEL PATTERN OF CLOSED LOW OVER SE CANADA FITS CLIMATOLOGY OF WEAK SNE TORNADOES SO CANT RULE OUT AN ISOLD BRIEF SPINUP. HI-RES GUIDANCE SHOWS ACTIVITY INCREASING DURING THE MORNING ACROSS W MA AND N CT THEN MOVING E INTO THE AFTERNOON. WHILE WE CANT RULE OUT A SHOWER OR TSTM IN THE COASTAL PLAIN...IT APPEARS MOST OF THE CONVECTION WILL REMAIN WEST OF BOS-PVD CORRIDOR TODAY. THE UNCERTAINTY FOR THE AFTERNOON IS THE EXTENT OF A POSSIBLE SECOND ROUND OF CONVECTION DEVELOPING IN W NEW ENG AS MID LEVEL DRYING WILL BE MOVING IN FROM THE WEST AND THIS COULD SUPPRESS ACTIVITY LATER IN THE AFTERNOON. LOWER CONFIDENCE ON POSSIBLE LATE DAY CONVECTION. IT WILL BE A RATHER HUMID DAY WITH DEWPOINTS INTO THE UPPER 60S TO LOWER 70S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... COLD FRONT WILL BE MOVING EAST ACROSS SNE TONIGHT. MODELS SHOW INSTABILITY PERSISTING THROUGH THE NIGHT AND EVENTUALLY BECOMING FOCUSED ACROSS E NEW ENG LATE TONIGHT. A FEW EVENING STORMS POSSIBLE...BUT MID LEVEL DRYING MOVING IN FROM THE WEST AND RAPIDLY DECREASING KI WILL SUPPRESS ACTIVITY WITH ANY CONVECTION AFTER MIDNIGHT BEING CONFINED TO E NEW ENG IN HIGHER KI AXIS. PATCHY LATE NIGHT FOG EXPECTED. MIN TEMPS MOSTLY IN THE 60S...WITH SOME UPPER 50S W MA. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * MAINLY DRY/SEASONABLE WITH COMFORTABLE HUMIDITY WED THROUGH SAT * ABOVE NORMAL TEMPS AND HUMIDITY LOOKS TO RETURN EARLY NEXT WEEK OVERVIEW... 00Z GUIDANCE IS IN GOOD AGREEMENT FOR THIS PORTION OF THE FORECAST. THERE ARE SOME UNCERTAINTY WITH REGARDS TO THE STRENGTH OF A FEW PASSING SHORTWAVES BUT THIS SHOULD NOT IMPACT THE OVERALL TREND IN THE FORECAST. HIGH PRESSURE WILL REMAIN OVER THE REGION UNTIL SUNDAY BEFORE MOVING OFFSHORE. A WEAK WAVE ON SUNDAY MAY BRING A FEW SHOWERS WHILE HIGH PRESSURE WILL BUILD RIGHT BEHIND THIS WAVE. DAILIES... WEDNESDAY INTO SATURDAY...HIGH CONFIDENCE. BULK OF THE PRECIP TUESDAY/TUESDAY NIGHT WILL BE OFFSHORE BY WEDNESDAY MORNING. HOWEVER...BECAUSE THIS FRONT IS SLOW MOVING AND WITH CYCLONIC FLOW ALOFT...COULD SEE LINGERING SHOWERS ACROSS EASTERN MASS DURING THE DAY. COLD FRONT SHOULD BE OFFSHORE BY THE LATE AFTERNOON AND BEHIND IT COMFORTABLE TEMPS AND HUMIDITY. UPPER LEVEL PATTERN WILL TURN FROM TROUGH TO ZONAL AS SURFACE HIGH PRESSURE BUILDS ACROSS THE NORTHEAST. THIS WILL KEEP NEAR NORMAL TEMPS AND LOW HUMIDITY THROUGH THE REMAINDER OF THE PERIOD. SUNDAY AND BEYOND...LOW CONFIDENCE. GUIDANCE BEGINS TO DIVERGE DURING THIS PERIOD AS THERE ARE SOME UNCERTAINTIES ON THE STRENGTHS OF EACH SHORTWAVE MOVING THROUGH THE FLOW. FOR NOW APPEARS THAT A STRETCHED SHORTWAVE WILL PASS SOUTHERN NEW ENGLAND...AND COMBINED WITH SOUTHERLY WINDS/INCREASING HUMIDITY THIS COULD TRIGGER A FEW LIGHT SHOWERS LATE SATURDAY NIGHT INTO SUNDAY. TEMPERATURES WILL BEGIN TO TREND ABOVE AVERAGE STARTING ON SUNDAY AND INTO THE FIRST WEEK OF SCHOOL FOR SOME. BOTH MODELS AND ENSEMBLES ARE HINTING AT UPPER 80S TO LOW 90S FOR THE WORK-WEEK AS UPPER LEVEL RIDGE TRIES TO BUILD. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/... TODAY...MODERATE CONFIDENCE. AREAS OF MVFR/IFR STRATUS WILL IMPROVE TO VFR AROUND 13/14Z. SCT SHOWERS/TSTMS WITH BRIEF MVFR/IFR EXPECTED IN THE MORNING W MA AND N CT...WITH A SECOND ROUND OF ACTIVITY POSSIBLE IN THE AFTERNOON...MAINLY INTERIOR. TONIGHT...MODERATE CONFIDENCE. EVENING SHOWERS/TSTMS WITH BRIEF MVFR/IFR POSSIBLE. MAY SEE SOME CONVECTION LINGER ACROSS E NEW ENG OVERNIGHT. PATCHY FOG DEVELOPING OVERNIGHT. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY THROUGH SATURDAY...VFR CONDITIONS. COULD SEE WEAK SEA BREEZES ALONG THE COASTLINES. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE. TODAY...S WINDS LESS THAN 20 KT WITH SEAS BELOW SCA. LOCALLY POOR VSBYS IN MORNING FOG. SCT SHOWERS AND ISOLD TSTMS SE WATERS THIS MORNING. TONIGHT...LIGHT S WINDS WITH SEAS BELOW SCA. VSBYS REDUCED IN PATCHY FOG. OUTLOOK /WEDNESDAY THROUGH SATURDAY/...HIGH CONFIDENCE. A PERIOD OF QUIET BOATING WEATHER IS EXPECTED THANKS TO BUILDING HIGH PRES. WINDS OUT OF THE W-NW THROUGH FRI...SHIFTING TO THE S BY SAT OR SUN. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/DUNTEN NEAR TERM...KJC/DUNTEN SHORT TERM...KJC LONG TERM...DUNTEN AVIATION...KJC/DUNTEN MARINE...KJC/DUNTEN
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
953 AM EDT TUE AUG 25 2015 ...Isolated strong-severe storms possible this afternoon in the FL Big Bend and south central GA... .Near Term [Through Today]... The 8 am EDT regional surface analysis showed a cold front extending southwestward from a weak low pressure center near Columbia SC, through Marianna, FL, then west-southwestward to the LA coast. Vapor imagery and upper air data showed a long wave trough over much of the eastern CONUS, with a weak upper level +PV anomaly over northern MS & AL. Until this short wave translates through our region, the cold front will make slow progress for the remainder of today. Pre-season cold front passages are often tricky, and this one is no different. The latest ECAM, NSSLECAM, and HRRR have trended much higher for PoPs today ahead of the cold front. They show the FL Big Bend sea breeze front, developing mid-late afternoon due to the mean opposing 1000-700 mb wind, colliding with the synoptic cold front near or south of I-10. With ample moisture, especially in the boundary layer, we expect scattered to numerous thunderstorms from Tallahassee east and southward. The only limiting factor will perhaps be some residual dry air above 700 mb. When we modify the 8 am Tallahassee sounding using our forecast afternoon temperature and dewpoint, we get a MLCAPE of 3,000, which is very high. The ECAM shows a 30% chance of strong updrafts ahead of the cold front, and 700-500 mb lapse rates will be around 6.1 C/km, which is a bit steeper than climo. Delta-theta values will be in the 25-30K range. All of this suggests a chance for isolated pulse severe storms. However, it`s unclear if, and how much, the dry air above 700 mb may retard the updraft speed and depth, which is why we still believe the threat for severe storms is only about 5% within 25 miles of a point. && .Aviation... [Through 12Z Wednesday] With the latest guidance trending upward for PoPs around KTLH and KVLD, we will be adding TSRA to the 18z TAF package. Gusty winds and poor cigs/Vis are likely in these storms. Otherwise, we expect VFR conditions through the period. && .Prev Discussion [345 AM EDT]... .Short Term [Tonight Through Thursday]... An upper level trough will remain in place over much of the eastern CONUS with surface high pressure centered over the lower Missouri River valley extending well to the southeast and into central Alabama. This high pressure will continue to push southeastward into our area, bringing in a slightly cooler and much drier airmass. This will allow mostly clear skies, cooler temperatures and only a slight chance (20%) for showers and thunderstorms in south central Georgia and the eastern Florida Big Bend. Temperatures will be in the low- mid 60s in southeast Alabama and southwest Georgia Wednesday and Thursday morning warming into the upper 80s to around 90 during the day. Further south and east, morning lows will be in the upper 60s to low 70s and afternoon highs will peak in the low 90s. .Long Term [Thursday Night Through Tuesday]... As surface high pressure shifts northeastward at the end of the workweek and a +PV anomaly breaks off of the upper level trough over the southeast, deep layer steering flow will shift to the south and begin to bring a return of moisture to the area. Chances for afternoon showers and thunderstorms will return to around 20-40% starting Friday, with the highest chances still over south central Georgia and the Florida Big Bend. Highs will be in the upper 80s to low 90s and morning lows will be in upper 60s to low-mid 70s. .Marine... A tighter pressure gradient in place today associated with a dry cold front will mean north-northwest winds approaching cautionary conditions over the western waters through Thursday morning. After that, the gradient will weaken and winds and seas will return to lower levels. .Fire Weather... Red flag conditions are not expected. Some lower relative humidity values, falling below 40% in some places, are expected over the next couple days with lower chances of rainfall. .Hydrology... With all rivers below flood stage and significant rain not expected, there are no hydrology concerns. && .Preliminary Point Temps/PoPs... Tallahassee 95 71 92 66 93 / 50 10 10 0 10 Panama City 90 71 87 70 86 / 10 0 0 0 10 Dothan 92 63 87 64 89 / 0 0 0 0 0 Albany 93 64 90 65 92 / 10 0 0 0 10 Valdosta 93 69 91 67 93 / 50 10 10 10 10 Cross City 95 75 91 73 90 / 30 20 20 20 20 Apalachicola 92 73 89 70 88 / 30 10 0 0 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AL...NONE. GM...NONE. && $$ NEAR TERM...FOURNIER SHORT TERM...MOORE LONG TERM...MOORE AVIATION...FOURNIER MARINE...MOORE FIRE WEATHER...LAMERS HYDROLOGY...WESTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
945 AM CDT TUE AUG 25 2015 .UPDATE... ISSUED AT 945 AM CDT TUE AUG 25 2015 RATHER COOL START TO THE DAY...WITH SEVERAL LOCATIONS FALLING BELOW 50 DEGREES. TEMPERATURES REBOUNDING NICELY THIS MORNING WITH SUNSHINE PREVAILING...MAINLY IN THE LOWER TO MID 60S AT 9 AM. AS THE UPPER LOW CONTINUES TO SPIN OVER EASTERN ONTARIO...THE LARGE STRATOCUMULUS SHIELD EXTENDING SOUTH ACROSS THE GREAT LAKES WILL EDGE INTO THE NORTHERN PARTS OF THE FORECAST AREA LATER THIS MORNING. THE EXISTING FORECAST HAD THESE ASPECTS UNDER CONTROL...AND LITTLE CHANGE WAS NEEDED. && .SHORT TERM...(TODAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 DEEP UPPER TROF FOR LATE AUGUST SITUATED JUST NORTH OF LAKE HURON EARLY THIS MORNING IS FORECAST TO SLOWLY EDGE EAST OVER THE NEXT FEW DAYS. MEANWHILE...SEVERAL WEAK SHORTWAVES ROTATING SOUTHEAST INTO THE LOWER GREAT LAKES WITH ONE SUCH FEATURE NOW PUSHING ACROSS SOUTH CENTRAL LAKE MICHIGAN. THIS WAVE MAY HAVE BEEN RESPONSIBLE FOR PUSHING THE STRATOCUMULUS DECK A BIT FURTHER SOUTH THAN ANTICIPATED LATE YESTERDAY THROUGH EARLY THIS MORNING. AS THE WEAK UPPER LEVEL DISTURBANCE PUSHES FURTHER OFF TO OUR EAST WE SHOULD SEE THE CLOUD DECK CONTINUE THIN OUT ACROSS OUR NORTHERN COUNTIES. HOWEVER, ADDITIONAL PIECES OF ENERGY ARE SEEN ROTATING SOUTHWARD AROUND THE LARGE UPPER LOW AND THAT COMBINED WITH DAYTIME HEATING MAY LEAD TO A LEAST SOME SCATTERED CLOUD COVER ACROSS THE NORTH LATER THIS MORNING INTO THE AFTERNOON HOURS. RAP FORECAST SOUNDINGS ONCE AGAIN INDICATING SOME STEEP LOW AND MID LEVEL LAPSE RATES ASSOCIATED WITH THE BROAD CYCLONIC FLOW OVER THE REGION WHICH WILL LEAD TO SOME GUSTY WEST TO NORTHWEST WINDS LATE THIS MORNING THRU THIS AFTERNOON. 850 MB TEMPS A FEW DEGREES COOLER THAN WHAT WE HAD AROUND OUR AREA YESTERDAY WHICH SHOULD PRODUCE AFTERNOON HIGHS MOSTLY IN THE MIDDLE 70S. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 QUIET FORECAST AT LEAST UNTIL THE END OF THE WORK WEEK WITH HIGH TEMPS SLIGHTLY BELOW NORMAL, BUT SLOWLY WARMING THROUGH THE END OF THE WEEK AHEAD OF THE NEXT SYSTEM. OVERNIGHT LOWS ALSO ON THE COOL SIDE AT LEAST UNTIL THE CLOUDS INCREASE SOMEWHAT AHEAD OF THE NEXT SYSTEM THURSDAY NIGHT IN THE NORTHWEST. PRECIP ASSOCIATED WITH THE UPPER LEVEL WAVE, HOWEVER, NOT ANTICIPATED TO IMPACT CENTRAL ILLINOIS UNTIL FRIDAY NIGHT/SATURDAY MORNING. SOME SLIGHT CHANCES CREEPING INTO NW OF THE ILLINOIS RIVER VALLEY FOR FRIDAY, WITH CHANCES INCREASING THROUGH THE OVERNIGHT AND INTO SAT MORNING. UPPER LEVEL DISTURBANCE IS DIFFUSE AND SLOW MOVING IN BOTH THE GFS AND THE ECMWF. THE NAM IS STARTING TO COME IN A LITTLE MORE COMPACT AND QUICKER, SO NOT OVERLY CONFIDENT WITH ANY PARTICULAR SOLUTION. THE GFS AND ECMWF HAVE BEEN BACK AND FORTH ENOUGH OVER THE LAST SEVERAL SYNOPTIC RUNS THAT CONSENSUS IS WEAK. ALSO NOT INCLINED TO LEAVE CHANCE POPS IN THE FORECAST ALL THE WAY THROUGH THE WEEKEND WITH THAT SLOW OF A SYSTEM. FOR NOW, WILL KEEP THE CONCENTRATION TO SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 600 AM CDT TUE AUG 25 2015 VFR CONDITIONS ARE EXPECTED THIS FORECAST PERIOD. A LARGE AREA OF HIGH PRESSURE OFF TO OUR NORTHWEST WILL SLOWLY BUILD SOUTHEAST INTO THE REGION OVER THE NEXT 24 HOURS KEEPING THE WEATHER ON THE QUIET SIDE. ABOUT THE ONLY CONCERN WILL BE WITH ANOTHER BAND OF VFR CIGS OVER PARTS OF SOUTHEAST MN AND WESTERN WI WHICH WILL SLIP SOUTHEAST AND AFFECT AT LEAST OUR NORTHERN TAF SITES LATER THIS MORNING THRU THIS AFTERNOON. CLOUD BASES LOOK TO BE IN THE 4000 TO 5000 FOOT RANGE BASED ON FORECAST SOUNDINGS FOR KPIA AND KBMI LATE THIS MORNING INTO THE AFTERNOON HOURS. AT THIS TIME WILL HOLD ON TO SCATTERED CLOUDS FOR THIS TIME FRAME BUT MAY NEED TO INCLUDE A TEMPO GROUP FOR OUR NORTHERN TAFS IF A MORE SOUTHWARD PUSH IS OBSERVED WITH THE CLOUD DECK TO OUR NORTH. SURFACE WINDS WILL ONCE AGAIN BECOME GUSTY OUT OF A NORTHWEST DIRECTION LATER THIS MORNING INTO THIS AFTERNOON. PREVAILING WIND SPEEDS WILL AVERAGE FROM 10 TO 15 KTS WITH A FEW GUSTS UP TO 20 KTS AT TIMES THRU THIS AFTERNOON BEFORE QUICKLY DIMINISHING BY 00Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEELHART SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
600 AM CDT TUE AUG 25 2015 .SHORT TERM...(TODAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 DEEP UPPER TROF FOR LATE AUGUST SITUATED JUST NORTH OF LAKE HURON EARLY THIS MORNING IS FORECAST TO SLOWLY EDGE EAST OVER THE NEXT FEW DAYS. MEANWHILE...SEVERAL WEAK SHORTWAVES ROTATING SOUTHEAST INTO THE LOWER GREAT LAKES WITH ONE SUCH FEATURE NOW PUSHING ACROSS SOUTH CENTRAL LAKE MICHIGAN. THIS WAVE MAY HAVE BEEN RESPONSIBLE FOR PUSHING THE STRATOCUMULUS DECK A BIT FURTHER SOUTH THAN ANTICIPATED LATE YESTERDAY THROUGH EARLY THIS MORNING. AS THE WEAK UPPER LEVEL DISTURBANCE PUSHES FURTHER OFF TO OUR EAST WE SHOULD SEE THE CLOUD DECK CONTINUE THIN OUT ACROSS OUR NORTHERN COUNTIES. HOWEVER, ADDITIONAL PIECES OF ENERGY ARE SEEN ROTATING SOUTHWARD AROUND THE LARGE UPPER LOW AND THAT COMBINED WITH DAYTIME HEATING MAY LEAD TO A LEAST SOME SCATTERED CLOUD COVER ACROSS THE NORTH LATER THIS MORNING INTO THE AFTERNOON HOURS. RAP FORECAST SOUNDINGS ONCE AGAIN INDICATING SOME STEEP LOW AND MID LEVEL LAPSE RATES ASSOCIATED WITH THE BROAD CYCLONIC FLOW OVER THE REGION WHICH WILL LEAD TO SOME GUSTY WEST TO NORTHWEST WINDS LATE THIS MORNING THRU THIS AFTERNOON. 850 MB TEMPS A FEW DEGREES COOLER THAN WHAT WE HAD AROUND OUR AREA YESTERDAY WHICH SHOULD PRODUCE AFTERNOON HIGHS MOSTLY IN THE MIDDLE 70S. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 QUIET FORECAST AT LEAST UNTIL THE END OF THE WORK WEEK WITH HIGH TEMPS SLIGHTLY BELOW NORMAL, BUT SLOWLY WARMING THROUGH THE END OF THE WEEK AHEAD OF THE NEXT SYSTEM. OVERNIGHT LOWS ALSO ON THE COOL SIDE AT LEAST UNTIL THE CLOUDS INCREASE SOMEWHAT AHEAD OF THE NEXT SYSTEM THURSDAY NIGHT IN THE NORTHWEST. PRECIP ASSOCIATED WITH THE UPPER LEVEL WAVE, HOWEVER, NOT ANTICIPATED TO IMPACT CENTRAL ILLINOIS UNTIL FRIDAY NIGHT/SATURDAY MORNING. SOME SLIGHT CHANCES CREEPING INTO NW OF THE ILLINOIS RIVER VALLEY FOR FRIDAY, WITH CHANCES INCREASING THROUGH THE OVERNIGHT AND INTO SAT MORNING. UPPER LEVEL DISTURBANCE IS DIFFUSE AND SLOW MOVING IN BOTH THE GFS AND THE ECMWF. THE NAM IS STARTING TO COME IN A LITTLE MORE COMPACT AND QUICKER, SO NOT OVERLY CONFIDENT WITH ANY PARTICULAR SOLUTION. THE GFS AND ECMWF HAVE BEEN BACK AND FORTH ENOUGH OVER THE LAST SEVERAL SYNOPTIC RUNS THAT CONSENSUS IS WEAK. ALSO NOT INCLINED TO LEAVE CHANCE POPS IN THE FORECAST ALL THE WAY THROUGH THE WEEKEND WITH THAT SLOW OF A SYSTEM. FOR NOW, WILL KEEP THE CONCENTRATION TO SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 600 AM CDT TUE AUG 25 2015 VFR CONDITIONS ARE EXPECTED THIS FORECAST PERIOD. A LARGE AREA OF HIGH PRESSURE OFF TO OUR NORTHWEST WILL SLOWLY BUILD SOUTHEAST INTO THE REGION OVER THE NEXT 24 HOURS KEEPING THE WEATHER ON THE QUIET SIDE. ABOUT THE ONLY CONCERN WILL BE WITH ANOTHER BAND OF VFR CIGS OVER PARTS OF SOUTHEAST MN AND WESTERN WI WHICH WILL SLIP SOUTHEAST AND AFFECT AT LEAST OUR NORTHERN TAF SITES LATER THIS MORNING THRU THIS AFTERNOON. CLOUD BASES LOOK TO BE IN THE 4000 TO 5000 FOOT RANGE BASED ON FORECAST SOUNDINGS FOR KPIA AND KBMI LATE THIS MORNING INTO THE AFTERNOON HOURS. AT THIS TIME WILL HOLD ON TO SCATTERED CLOUDS FOR THIS TIME FRAME BUT MAY NEED TO INCLUDE A TEMPO GROUP FOR OUR NORTHERN TAFS IF A MORE SOUTHWARD PUSH IS OBSERVED WITH THE CLOUD DECK TO OUR NORTH. SURFACE WINDS WILL ONCE AGAIN BECOME GUSTY OUT OF A NORTHWEST DIRECTION LATER THIS MORNING INTO THIS AFTERNOON. PREVAILING WIND SPEEDS WILL AVERAGE FROM 10 TO 15 KTS WITH A FEW GUSTS UP TO 20 KTS AT TIMES THRU THIS AFTERNOON BEFORE QUICKLY DIMINISHING BY 00Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1004 AM EDT TUE AUG 25 2015 .UPDATE... ISSUED AT 1003 AM EDT TUE AUG 25 2015 UPDATED NDFD HOURLY TEMPERATURE AND DEWPOINTS BASED ON LATEST OBSERVATIONAL TRENDS AND REMOVED THE MORNING FOG FROM THE ZFP. UPDATE ISSUED AT 720 AM EDT TUE AUG 25 2015 DID A QUICK UPDATE TO THE GRIDS USING THE LATEST OBS AND TRENDS FOR THE T AND TD GRIDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM EDT TUE AUG 25 2015 06Z SFC ANALYSIS SHOWS A LARGE AREA OF COOL AND DRY HIGH PRESSURE BUILDING INTO THE OHIO VALLEY FROM THE NORTHWEST. THIS HAS KEPT THE SKIES MOSTLY CLEAR DURING THE NIGHT AND ALLOWED FOR A GOOD NIGHT OF RADIATIONAL COOLING BELOW THE INVERSION. AS IS TYPICAL... THIS HAS RESULTED IN A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT RANGING FROM THE MID 50S IN SHELTERED LOCATIONS TO THE LOWER 60S ON THE RIDGES. DEWPOINTS MEANWHILE ARE IN THE LOW TO MID 50S ACROSS THE CWA WITH LIGHT WINDS FROM THE WEST ABOVE THE INVERSION. JUST A HINT OF VALLEY FOG IS NOTED IN THE MONTICELLO OBSERVATION AND IN SOME OF THE WEB CAMS. THE MODELS REMAIN IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THE ALL ARE VERY SIMILAR WITH THE DEEP... AND CLOSED...LOW SLOWLY MOVING INTO SOUTHEAST CANADA AND THE EASTERN GREAT LAKES TODAY THROUGH WEDNESDAY. THIS WILL PLACE THE OHIO VALLEY AND KENTUCKY IN THE MIDST OF LOW HEIGHTS WHILE WEAK PACKETS OF ENERGY MOVE BY AT MID LEVELS IN BROAD NORTHWEST FLOW. GIVEN THE MINUSCULE MODEL SPREAD WILL USE A GENERAL BLEND SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12. CAPITAL WEATHER WILL BE THE RULE THROUGH THE SHORT TERM WITH MINIMAL CLOUDS...LOW AFTERNOON HUMIDITIES...AND COOL NIGHTS. THE SFC HIGH PRESSURE WILL SPREAD OVER KENTUCKY AND KEEP THE BULK OF ANY CLOUDS...ASSOCIATED WITH THE PASSING UPPER LOW...TO A MINIMUM. HIGHS WILL END UP IN THE MID 70S FOR MOST SPOTS TODAY AND WEDNESDAY. AT NIGHT...LOOK FOR A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP IN CONJUNCTION WITH AN INVERSION SETTING UP. CANNOT RULE OUT PATCHY FOG IN THE MORE SHELTERED LOCATIONS TOWARDS DAWN THIS MORNING AND AGAIN ON WEDNESDAY MORNING. THE COOL AIR MAY SET A RECORD LOW TONIGHT AT JKL...CURRENTLY A MILD 58 DEGREES FROM 1984...BUT PROBABLY LOZ/S 46 DEGREE RECORD FROM 1966 WILL STAY OUT OF REACH. AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THIS EVENING BEFORE INITIATING WITH THE SUPERBLEND INTO WEDNESDAY EVENING. DID MAKE SOME DECENT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEN EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD... IN LINE WITH MOS GUIDANCE. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 333 AM EDT TUE AUG 25 2015 SFC HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL PROVIDE US WITH PLEASANT WEATHER FOR THE BEGINNING OF THE EXTENDED PERIOD. HOWEVER THIS WILL BE SHORT LIVED AS THE HIGH IS EXPECTED TO MOVE OFF TO THE EAST BY SATURDAY. THIS WILL ALLOW FOR WEAK RETURN FLOW TO USHER IN LL MOISTURE...HIGHER DEWPOINTS AND WARMER TEMPERATURES FOR THE WEEKEND. AN UPPER LEVEL SHORTWAVE AND ASSOCIATED FRONT WILL APPROACH THE AREA FROM THE PLAINS...BRINGING RENEWED CHANCES FOR PRECIP EACH AFTERNOON SATURDAY THROUGH MONDAY. THE BEST CHANCE FOR MEASURABLE PRECIP WILL LIKELY BE ON MONDAY AS THE UPPER LEVEL WAVE MOVES THROUGH OUR REGION. HOWEVER...THERE ARE SOME DIFFERENCES ON HOW THE MODELS HANDLE THIS UPPER LEVEL FEATURE...WHICH WILL ULTIMATELY DETERMINE HOW MUCH PRECIP WE COULD GET. SO FOR NOW HAVE STUCK CLOSE TO THE CR SUPERBLEND AND MAINTAINED SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES WILL BEGIN BELOW NORMAL ON THURSDAY BUT THEN GRADUALLY WARM THROUGH THE REST OF THE EXTENDED PERIOD WITH HIGHS RETURNING TO THE MID TO UPPER 80S BY MONDAY. HUMIDITY WILL FOLLOW THE SAME TREND...WITH DEWPOINTS INCREASING INTO THE MID 60S BY SUNDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 750 AM EDT TUE AUG 25 2015 HIGH PRESSURE IS CONTINUING TO NOSE INTO EASTERN KENTUCKY TODAY. THIS IS BRINGING DRIER AIR AND CLEAR SKIES TO THE REGION... TRANSLATING TO MOSTLY VFR CONDITIONS. THESE VFR CONDITIONS ARE EXPECTED TO THE PREVAIL THROUGH THE PERIOD AS THE HIGH FURTHER BUILDS OVER THE REGION. THE ONLY EXCEPTION IS SOME PATCHY DENSE FOG THAT HAS SHOWN UP IN THE FAR SOUTHERN PARTS OF THE AREA AFFECTING THE SME SITE LIKELY THROUGH AROUND 13Z. HAVE ALSO ADDED SOME MVFR FOG TO JUST SME FOR WEDNESDAY MORNING. WINDS WILL REMAIN LIGHT THROUGH 12Z WEDNESDAY...GENERALLY FROM WEST TO NORTHWEST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...JVM AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
750 AM EDT TUE AUG 25 2015 .UPDATE... ISSUED AT 720 AM EDT TUE AUG 25 2015 DID A QUICK UPDATE TO THE GRIDS USING THE LATEST OBS AND TRENDS FOR THE T AND TD GRIDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM EDT TUE AUG 25 2015 06Z SFC ANALYSIS SHOWS A LARGE AREA OF COOL AND DRY HIGH PRESSURE BUILDING INTO THE OHIO VALLEY FROM THE NORTHWEST. THIS HAS KEPT THE SKIES MOSTLY CLEAR DURING THE NIGHT AND ALLOWED FOR A GOOD NIGHT OF RADIATIONAL COOLING BELOW THE INVERSION. AS IS TYPICAL... THIS HAS RESULTED IN A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT RANGING FROM THE MID 50S IN SHELTERED LOCATIONS TO THE LOWER 60S ON THE RIDGES. DEWPOINTS MEANWHILE ARE IN THE LOW TO MID 50S ACROSS THE CWA WITH LIGHT WINDS FROM THE WEST ABOVE THE INVERSION. JUST A HINT OF VALLEY FOG IS NOTED IN THE MONTICELLO OBSERVATION AND IN SOME OF THE WEB CAMS. THE MODELS REMAIN IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THE ALL ARE VERY SIMILAR WITH THE DEEP... AND CLOSED...LOW SLOWLY MOVING INTO SOUTHEAST CANADA AND THE EASTERN GREAT LAKES TODAY THROUGH WEDNESDAY. THIS WILL PLACE THE OHIO VALLEY AND KENTUCKY IN THE MIDST OF LOW HEIGHTS WHILE WEAK PACKETS OF ENERGY MOVE BY AT MID LEVELS IN BROAD NORTHWEST FLOW. GIVEN THE MINUSCULE MODEL SPREAD WILL USE A GENERAL BLEND SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12. CAPITAL WEATHER WILL BE THE RULE THROUGH THE SHORT TERM WITH MINIMAL CLOUDS...LOW AFTERNOON HUMIDITIES...AND COOL NIGHTS. THE SFC HIGH PRESSURE WILL SPREAD OVER KENTUCKY AND KEEP THE BULK OF ANY CLOUDS...ASSOCIATED WITH THE PASSING UPPER LOW...TO A MINIMUM. HIGHS WILL END UP IN THE MID 70S FOR MOST SPOTS TODAY AND WEDNESDAY. AT NIGHT...LOOK FOR A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP IN CONJUNCTION WITH AN INVERSION SETTING UP. CANNOT RULE OUT PATCHY FOG IN THE MORE SHELTERED LOCATIONS TOWARDS DAWN THIS MORNING AND AGAIN ON WEDNESDAY MORNING. THE COOL AIR MAY SET A RECORD LOW TONIGHT AT JKL...CURRENTLY A MILD 58 DEGREES FROM 1984...BUT PROBABLY LOZ/S 46 DEGREE RECORD FROM 1966 WILL STAY OUT OF REACH. AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THIS EVENING BEFORE INITIATING WITH THE SUPERBLEND INTO WEDNESDAY EVENING. DID MAKE SOME DECENT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEN EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD... IN LINE WITH MOS GUIDANCE. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 333 AM EDT TUE AUG 25 2015 SFC HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL PROVIDE US WITH PLEASANT WEATHER FOR THE BEGINNING OF THE EXTENDED PERIOD. HOWEVER THIS WILL BE SHORT LIVED AS THE HIGH IS EXPECTED TO MOVE OFF TO THE EAST BY SATURDAY. THIS WILL ALLOW FOR WEAK RETURN FLOW TO USHER IN LL MOISTURE...HIGHER DEWPOINTS AND WARMER TEMPERATURES FOR THE WEEKEND. AN UPPER LEVEL SHORTWAVE AND ASSOCIATED FRONT WILL APPROACH THE AREA FROM THE PLAINS...BRINGING RENEWED CHANCES FOR PRECIP EACH AFTERNOON SATURDAY THROUGH MONDAY. THE BEST CHANCE FOR MEASURABLE PRECIP WILL LIKELY BE ON MONDAY AS THE UPPER LEVEL WAVE MOVES THROUGH OUR REGION. HOWEVER...THERE ARE SOME DIFFERENCES ON HOW THE MODELS HANDLE THIS UPPER LEVEL FEATURE...WHICH WILL ULTIMATELY DETERMINE HOW MUCH PRECIP WE COULD GET. SO FOR NOW HAVE STUCK CLOSE TO THE CR SUPERBLEND AND MAINTAINED SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES WILL BEGIN BELOW NORMAL ON THURSDAY BUT THEN GRADUALLY WARM THROUGH THE REST OF THE EXTENDED PERIOD WITH HIGHS RETURNING TO THE MID TO UPPER 80S BY MONDAY. HUMIDITY WILL FOLLOW THE SAME TREND...WITH DEWPOINTS INCREASING INTO THE MID 60S BY SUNDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 750 AM EDT TUE AUG 25 2015 HIGH PRESSURE IS CONTINUING TO NOSE INTO EASTERN KENTUCKY TODAY. THIS IS BRINGING DRIER AIR AND CLEAR SKIES TO THE REGION... TRANSLATING TO MOSTLY VFR CONDITIONS. THESE VFR CONDITIONS ARE EXPECTED TO THE PREVAIL THROUGH THE PERIOD AS THE HIGH FURTHER BUILDS OVER THE REGION. THE ONLY EXCEPTION IS SOME PATCHY DENSE FOG THAT HAS SHOWN UP IN THE FAR SOUTHERN PARTS OF THE AREA AFFECTING THE SME SITE LIKELY THROUGH AROUND 13Z. HAVE ALSO ADDED SOME MVFR FOG TO JUST SME FOR WEDNESDAY MORNING. WINDS WILL REMAIN LIGHT THROUGH 12Z WEDNESDAY...GENERALLY FROM WEST TO NORTHWEST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...JVM AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
728 AM EDT TUE AUG 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT TUE AUG 25 2015 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UNSEASONABLY DEEP CLOSED LO IN ONTARIO JUST NE OF LK SUP DRIFTING SLOWLY TO THE E... WITH SHARP CYC FLOW ARND THIS FEATURE DOMINATING THE GREAT LKS. LOCAL RAOBS INDICATE THE SFC-H7 LYR IS QUITE MOIST WITH H925...H85 AND H7 DEWPT DEPRESSIONS AT INL AND E NO MORE THAN A FEW DEGREES C. THERE ARE ALSO TWO SHRTWVS OF NOTE ROTATING ARND THE LARGER SCALE FEATURE. THE FIRST OF THESE IS NOW HEADING INTO NRN LK MI AT THE BEGINNING OF THE SHIFT AND TAKING THE MORE WIDESPREAD SHOWERS THAT HAD IMPACTED THE ERN CWA LAST EVNG TO THE SE WITH IT. IN THE WAKE OF THIS DISTURBANCE...SFC OBS AND THE MQT 88D INDICATE RELATIVELY FEW SHOWERS...MAINLY JUST SOME DRIZZLE...LINGER OVER UPR MI EARLY THIS MRNG DESPITE THE MOIST LLVLS AND SHARP CYC NW FLOW. THE CULPRITS APPEAR TO BE LARGER SCALE QVECTOR DVGC TO THE W OF THE CLOSED LO AND BEHIND THE DEPARTING SHRTWV AND RATHER SHARP H875-85 INVRN SHOWN ON THE 00Z INL/YPL RAOBS ASSOCIATED WITH THESE NEGATIVE DYNAMICS/HGT RISES THAT IS LIMITING THE LK EFFECT COMPONENT TO THE NE OF H85 THERMAL TROF CENTERED ON AN AXIS FM INL TO GRB. 00Z H85 TEMPS WERE 3C AT INL AND GRB...BUT 10C AT YPL. WV IMAGERY/RAP ANALYSIS INDICATE ANOTHER SHRTWV ROTATING SWD TO THE W OF THE CLOSED LO IS DROPPING THRU NW ONTARIO. THE LATEST THUNDER BAY RADAR SHOWS AN AREA OF MORE NMRS SHOWERS OVER LK NIPIGON MOVING INTO NRN LK SUP. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS ASSOCIATED SHRTWV ROTATING SWD ARND SLOWLY DEPARTING CLOSED LO. TODAY...WHILE ONTARIO SHRTWV MOVING TO THE S IS ON TRACK TO MOVE INTO NRN LK SUP THIS MRNG...MODELS INDICATE DEEP LYR QVECTOR DVGC AND HGT RISES...FCST TO BE ABOUT 50M BTWN 12Z-24Z TODAY...LEFT IN THE WAKE OF THE CLOSED LO WL DOMINATE. SO ALTHOUGH FCST PROFILES INDICATE SOME DEEPENING MSTR THRU THIS MRNG...THEY ALSO SHOW A NEAR ABSENCE OF ANY UVV...IN FACT MAINLY LARGE SCALE SUBSIDENCE THAT WL MAINTAIN THE INVRN NEAR H85 AND LIMIT POPS. THE ERN CWA HAS A BETTER CHC TO SEE THE HIER POPS...AS THIS AREA WL BE CLOSER TO THE DEPARTING DISTURBANCE/WEAKER SUBSIDENCE WITH AT LEAST SOME UVV/ SHARPER CYC FLOW AND DOWNSTREAM OF LK SUP IN PERSISTENT NW FLOW THAT WL ACCENTUATE LLVL CNVGC. GIVEN THESE NEGATIVES...TENDED TO LOWER GOING POPS. PLENTY OF LO CLDS WL LIMIT THE DIURNAL TEMP RECOVERY AGAIN DESPITE SLOWLY MODERATING H85 TEMPS THAT WL ALLOW FOR A WARMER DAY THAN YDAY. THE STEADY/GUSTY NW WINDS WL CONTINUE TO WHIP UP HI WAVES ON LAKE SUP...RESULTING IN A HI SWIM RISK FOR MARQUETTE AND ALGER COUNTIES. TNGT...WITH CONTINUED SLOW HGT RISES/DEEP LYR QVECTOR DVGC/WEAKENING LLVL CYC FLOW TO THE W OF WEAKENING CLOSED LO THAT IS FCST TO LIFT NE TOWARD THE S END OF JAMES BAY BY 12Z WED...EXPECT DIMINISHING POPS. THIS TREND WL BE MOST PRONOUNCED OVER THE W...WHERE THE LLVL FLOW WL BECOME MORE ACYC CLOSER TO APRCHG SFC HI PRES MOVING INTO MN. LINGERING LO CLDS WL LIMIT THE DIURNAL TEMP FALL. EXPECT THE COOLEST OVERNGT LOWS TOWARD THE MID 40S OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLRG LATE WITH THE APRCH OF THE SFC HI PRES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 251 AM EDT TUE AUG 25 2015 COULD SEE SOME ISOLATES SHOWERS OVER THE ERN CWA WED MORNING AS NW WINDS AND 850MB TEMPS OF 5-6C ALLOW FOR LAKE ENHANCED RAIN...BUT OVERALL FORCING WILL BE WEAK. HIGH PRESSURE MOVING IN WILL BRING AN END TO RAIN POTENTIAL BY WED AFTERNOON. HIGHS WED IN THE 60S WILL COMBINE WITH GOOD RADIATIONAL COOLING...DRY CONDITIONS AND LIGHT WINDS WED NIGHT TO BRING LOWS IN THE 40S INLAND...WITH A FEW SPOTS IN THE UPPER 30S. SW FLOW AS THE HIGH MOVES OUT WILL BRING 850MB TEMPS UP TO 14C BY THE END OF THE DAY THU...RESULTING IN NEAR NORMAL HIGHS IN THE LOW TO MID 70S. DRY WEATHER PERSISTS THROUGH THU. MODELS CONTINUE TO INDICATE A COLD FRONT MOVING S FROM CANADA AND INTO THE CWA THU NIGHT AND FRI WHILE A SHORTWAVE RIDES DOWN NW FLOW AND PASSES OVER OR NEAR THE CWA. MODELS HAVE BEEN VARIABLE WITH SOLUTIONS FOR THIS TIME PERIOD...BUT THE ECMWF HAS BEEN THE MOST STEADY. OVERALL...CHANCES FOR SHOWERS AND THUNDERSTORMS SEEM REASONABLE. PRECIP IS QUESTIONABLE FOR SAT...BUT COULD SEE SOME SHOWERS IF SHORTWAVE ENERGY MOVES THROUGH. LEFT SLIGHT CHANCE POPS FOR NOW. TEMPS LOOK SIMILAR TO FRI. TEMPS LOOK TO BE ABOVE NORMAL SUN AND MON WITH DRY WEATHER AS RIDGING BUILDS OVER THE AREA. HIGHS SHOULD RANGE FROM THE MID/UPPER 70S TO LOW 80S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 726 AM EDT TUE AUG 25 2015 A GUSTY NW FLOW OF COOL...MOIST AIR AROUND LO PRES TO THE NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO THE TAF SITES THIS FCST PERIOD. THE ONE EXCEPTION WL BE AT IWD TNGT...WHEN THE CLOSER APRCH OF HI PRES AND SOME DRYING/A WEAKENING OF THE LLVL CYC FLOW WL LIKELY ALLOW AN IMPROVEMENT TO MARGINAL VFR. SOME -SHRA/-DZ ASSOCIATED WITH A PASSING UPR DISTURBANCE THIS MRNG MAY BRING SOME BRIEF IFR CONDITIONS TO MAINLY CMX...BUT THIS POTENTIAL WL DIMINISH BY LATE MRNG FOLLOWING THE PASSAGE OF THAT DISTURBANCE. THE STRONGEST WIND GUSTS UP TO 25 KTS WL OCCUR AT THE MORE EXPOSED CMX SITE THRU TODAY...BUT EVEN THERE THE WINDS WL DIMINISH THIS EVNG WITH LOSS OF HEATING/SLOWLY WEAKENING PRES GRADIENT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT TUE AUG 25 2015 SHARP PRES GRADIENT ON THE WESTERN FLANK OF DEEP LO PRES MOVING THRU ONTARIO TO THE E OF LAKE SUPERIOR WILL MAINTAIN NW WINDS UP TO 30 KTS TODAY. THE PASSAGE OF A DISTURBANCE THIS MORNING MAY CAUSE SOME GALE FORCE GUSTS IN A CORRIDOR OVER THE CENTRAL LAKE. BUT AS THE LO TO THE E WEAKENS AND MOVES TOWARD JAMES BAY TONIGHT...APPROACHING HI PRES/WEAKENING PRES GRADIENT WILL CAUSE WINDS TO DIMINISH W-E. AS THE HI MOVES OVER THE UPPER LAKES LATE WED/WED NIGHT...EXPECT WINDS TO FALL UNDER 20 KTS. A RELATIVELY FLAT PRES GRADIENT WILL DOMINATE LATE WEEK INTO THE WEEKEND...SO WINDS FOR THE MOST PART SHOULD BE UNDER 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...BEACH HAZARDS STATEMENT INTO THIS EVENING FOR MIZ005-006. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 AM EDT TUE AUG 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT TUE AUG 25 2015 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UNSEASONABLY DEEP CLOSED LO IN ONTARIO JUST NE OF LK SUP DRIFTING SLOWLY TO THE E... WITH SHARP CYC FLOW ARND THIS FEATURE DOMINATING THE GREAT LKS. LOCAL RAOBS INDICATE THE SFC-H7 LYR IS QUITE MOIST WITH H925...H85 AND H7 DEWPT DEPRESSIONS AT INL AND E NO MORE THAN A FEW DEGREES C. THERE ARE ALSO TWO SHRTWVS OF NOTE ROTATING ARND THE LARGER SCALE FEATURE. THE FIRST OF THESE IS NOW HEADING INTO NRN LK MI AT THE BEGINNING OF THE SHIFT AND TAKING THE MORE WIDESPREAD SHOWERS THAT HAD IMPACTED THE ERN CWA LAST EVNG TO THE SE WITH IT. IN THE WAKE OF THIS DISTURBANCE...SFC OBS AND THE MQT 88D INDICATE RELATIVELY FEW SHOWERS...MAINLY JUST SOME DRIZZLE...LINGER OVER UPR MI EARLY THIS MRNG DESPITE THE MOIST LLVLS AND SHARP CYC NW FLOW. THE CULPRITS APPEAR TO BE LARGER SCALE QVECTOR DVGC TO THE W OF THE CLOSED LO AND BEHIND THE DEPARTING SHRTWV AND RATHER SHARP H875-85 INVRN SHOWN ON THE 00Z INL/YPL RAOBS ASSOCIATED WITH THESE NEGATIVE DYNAMICS/HGT RISES THAT IS LIMITING THE LK EFFECT COMPONENT TO THE NE OF H85 THERMAL TROF CENTERED ON AN AXIS FM INL TO GRB. 00Z H85 TEMPS WERE 3C AT INL AND GRB...BUT 10C AT YPL. WV IMAGERY/RAP ANALYSIS INDICATE ANOTHER SHRTWV ROTATING SWD TO THE W OF THE CLOSED LO IS DROPPING THRU NW ONTARIO. THE LATEST THUNDER BAY RADAR SHOWS AN AREA OF MORE NMRS SHOWERS OVER LK NIPIGON MOVING INTO NRN LK SUP. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS ASSOCIATED SHRTWV ROTATING SWD ARND SLOWLY DEPARTING CLOSED LO. TODAY...WHILE ONTARIO SHRTWV MOVING TO THE S IS ON TRACK TO MOVE INTO NRN LK SUP THIS MRNG...MODELS INDICATE DEEP LYR QVECTOR DVGC AND HGT RISES...FCST TO BE ABOUT 50M BTWN 12Z-24Z TODAY...LEFT IN THE WAKE OF THE CLOSED LO WL DOMINATE. SO ALTHOUGH FCST PROFILES INDICATE SOME DEEPENING MSTR THRU THIS MRNG...THEY ALSO SHOW A NEAR ABSENCE OF ANY UVV...IN FACT MAINLY LARGE SCALE SUBSIDENCE THAT WL MAINTAIN THE INVRN NEAR H85 AND LIMIT POPS. THE ERN CWA HAS A BETTER CHC TO SEE THE HIER POPS...AS THIS AREA WL BE CLOSER TO THE DEPARTING DISTURBANCE/WEAKER SUBSIDENCE WITH AT LEAST SOME UVV/ SHARPER CYC FLOW AND DOWNSTREAM OF LK SUP IN PERSISTENT NW FLOW THAT WL ACCENTUATE LLVL CNVGC. GIVEN THESE NEGATIVES...TENDED TO LOWER GOING POPS. PLENTY OF LO CLDS WL LIMIT THE DIURNAL TEMP RECOVERY AGAIN DESPITE SLOWLY MODERATING H85 TEMPS THAT WL ALLOW FOR A WARMER DAY THAN YDAY. THE STEADY/GUSTY NW WINDS WL CONTINUE TO WHIP UP HI WAVES ON LAKE SUP...RESULTING IN A HI SWIM RISK FOR MARQUETTE AND ALGER COUNTIES. TNGT...WITH CONTINUED SLOW HGT RISES/DEEP LYR QVECTOR DVGC/WEAKENING LLVL CYC FLOW TO THE W OF WEAKENING CLOSED LO THAT IS FCST TO LIFT NE TOWARD THE S END OF JAMES BAY BY 12Z WED...EXPECT DIMINISHING POPS. THIS TREND WL BE MOST PRONOUNCED OVER THE W...WHERE THE LLVL FLOW WL BECOME MORE ACYC CLOSER TO APRCHG SFC HI PRES MOVING INTO MN. LINGERING LO CLDS WL LIMIT THE DIURNAL TEMP FALL. EXPECT THE COOLEST OVERNGT LOWS TOWARD THE MID 40S OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLRG LATE WITH THE APRCH OF THE SFC HI PRES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 251 AM EDT TUE AUG 25 2015 COULD SEE SOME ISOLATES SHOWERS OVER THE ERN CWA WED MORNING AS NW WINDS AND 850MB TEMPS OF 5-6C ALLOW FOR LAKE ENHANCED RAIN...BUT OVERALL FORCING WILL BE WEAK. HIGH PRESSURE MOVING IN WILL BRING AN END TO RAIN POTENTIAL BY WED AFTERNOON. HIGHS WED IN THE 60S WILL COMBINE WITH GOOD RADIATIONAL COOLING...DRY CONDITIONS AND LIGHT WINDS WED NIGHT TO BRING LOWS IN THE 40S INLAND...WITH A FEW SPOTS IN THE UPPER 30S. SW FLOW AS THE HIGH MOVES OUT WILL BRING 850MB TEMPS UP TO 14C BY THE END OF THE DAY THU...RESULTING IN NEAR NORMAL HIGHS IN THE LOW TO MID 70S. DRY WEATHER PERSISTS THROUGH THU. MODELS CONTINUE TO INDICATE A COLD FRONT MOVING S FROM CANADA AND INTO THE CWA THU NIGHT AND FRI WHILE A SHORTWAVE RIDES DOWN NW FLOW AND PASSES OVER OR NEAR THE CWA. MODELS HAVE BEEN VARIABLE WITH SOLUTIONS FOR THIS TIME PERIOD...BUT THE ECMWF HAS BEEN THE MOST STEADY. OVERALL...CHANCES FOR SHOWERS AND THUNDERSTORMS SEEM REASONABLE. PRECIP IS QUESTIONABLE FOR SAT...BUT COULD SEE SOME SHOWERS IF SHORTWAVE ENERGY MOVES THROUGH. LEFT SLIGHT CHANCE POPS FOR NOW. TEMPS LOOK SIMILAR TO FRI. TEMPS LOOK TO BE ABOVE NORMAL SUN AND MON WITH DRY WEATHER AS RIDGING BUILDS OVER THE AREA. HIGHS SHOULD RANGE FROM THE MID/UPPER 70S TO LOW 80S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 724 AM EDT TUE AUG 25 2015 A GUSTY NW FLOW OF COOL...MOIST AIR AROUND LO PRES TO THE NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO THE TAF SITES THIS FCST PERIOD. THE ONE EXCEPTION WL BE AT IWD TNGT...WHEN THE CLOSER APRCH OF HI PRES AND SOME DRYING/A WEAKENING OF THE LLVL CYC FLOW WL LIKELY ALLOW AN IMPROVEMENT TO MARGINAL VFR. SOME -SHRA/-DZ ASSOCIATED WITH A PASSING UPR DISTURBANCE THIS MRNG MAY BRING SOME BRIEF IFR CONDITIONS TO MAINLY CMX...BUT THIS POTENTIAL WL DIMINISH BY LATE MRNG FOLLOWING THE PASSAGE OF THAT DISTURBANCE. THE STRONGEST WIND GUSTS UP TO 25 KTS WL OCCUR AT THE MORE EXPOSED CMX SITE THRU TODAY...BUT EVEN THERE THE WINDS WL DIMINISH THIS EVNG WITH LOSS OF HEATING/SLOWLY WEAKENING PRES GRADIENT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT TUE AUG 25 2015 SHARP PRES GRADIENT ON THE WESTERN FLANK OF DEEP LO PRES MOVING THRU ONTARIO TO THE E OF LAKE SUPERIOR WILL MAINTAIN NW WINDS UP TO 30 KTS TODAY. THE PASSAGE OF A DISTURBANCE THIS MORNING MAY CAUSE SOME GALE FORCE GUSTS IN A CORRIDOR OVER THE CENTRAL LAKE. BUT AS THE LO TO THE E WEAKENS AND MOVES TOWARD JAMES BAY TONIGHT...APPROACHING HI PRES/WEAKENING PRES GRADIENT WILL CAUSE WINDS TO DIMINISH W-E. AS THE HI MOVES OVER THE UPPER LAKES LATE WED/WED NIGHT...EXPECT WINDS TO FALL UNDER 20 KTS. A RELATIVELY FLAT PRES GRADIENT WILL DOMINATE LATE WEEK INTO THE WEEKEND...SO WINDS FOR THE MOST PART SHOULD BE UNDER 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1051 AM CDT TUE AUG 25 2015 .UPDATE...COMPLEX OF STORMS ACROSS NORTHEAST TEXAS CONTINUE TO DROP SOUTH LATE THIS MORNING INTO EAST TEXAS. AN ASSOCIATED OUTFLOW/FRONTAL BOUNDARY ON THE SOUTHWEST SIDE OF THE COMPLEX STRETCHES ALONG ROUGHLY A HILLSBORO TO MADISONVILLE LINE...AND WILL CONTINUE TO PUSH SOUTHWEST INTO NORTHERN AND EASTERN PORTIONS OF THE CWA BY EARLY AFTERNOON. INITIALIZATION BY SEVERAL MODELS WAS POOR...BUT LATEST FEW RUNS OF THE HRRR APPEARS TO BE TRENDING BETTER. AS CONVECTIVE TEMPERATURES ARE REACHED EARLY TO MID AFTERNOON...AND WITH FORCING ASSOCIATED WITH BOUNDARY DROPPING SOUTHWEST...EXPECT ISOLATED TO SCATTERED SHOWERS AND STORMS DEVELOPING NORTH OF A FREDERICKSBURG TO SAN MARCOS TO LA GRANGE LINE...BETWEEN 1 AND 3 PM AS DEPICTED BY HRRR. OUTFLOW FROM STORMS SHOULD CONTINUE TO AID IN PUSHING THE BOUNDARY SOUTH AND WEST THROUGH THE LATE AFTERNOON...SOUTH OF I-10. BUFR SOUNDINGS SUPPORTIVE OF A FEW STRONGER DOWNDRAFTS...WITH FORECAST DCAPE VALUES OF 1300-1500 J/KG...CURRENTLY HANDLED AND MENTIONED IN THE HWO. && .PREV DISCUSSION... /ISSUED 649 AM CDT TUE AUG 25 2015/ AVIATION... /12Z TAF UPDATE/ TAF SITES SHOULD SEE VFR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW AREAS WITH VSBY RESTRICTIONS NEAR THUNDERSTORMS. THE GREATER STORM IMPACTS MAY BE GUSTY WINDS THAT COULD EXCEED 30 KNOTS IN SOME CASES. HI-RES MODELS TIME THE AREA OF CONVECTION FASTER THAN THE SYNOPTIC MODELS...AND THE CLUSTER OF STORMS OVER NE TX WOULD SUGGEST THAT THIS TIMING IS BETTER. COLLECTIVE OUTFLOWS FROM THE CONVECTION SHOULD LEAVE LIGHT WINDS AND LIMITED CLOUDS IN LOW LEVELS FOR THE REMAINDER OF THE TAF PERIOD. THIS ASSUMES THAT MOST RAINFALL AMOUNTS WILL BE SPORADIC AND WELL BELOW 1/2 INCH. PREV DISCUSSION... /ISSUED 357 AM CDT TUE AUG 25 2015/ SHORT TERM (TODAY THROUGH WEDNESDAY)... MID TO UPPER LEVEL RIDGE ALONG A ROCKIES INTO TEXAS AXIS SHIFTS TO A CENTRAL HIGH PLAINS INTO NORTHERN MEXICO AXIS BY WEDNESDAY AS A MID TO UPPER LEVEL TROUGH DEEPENS OVER THE EASTERN STATES. THIS ALLOWS A POOL OF DEEPER MOISTURE WITH PWS OF 1.5 TO 1.9 INCHES ALONG A FRONTAL ZONE OVER NORTHERN TEXAS TO DRIFT TO THE SOUTHWEST INTO SOUTH CENTRAL TEXAS TODAY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ON DAYTIME HEATING OVER NORTHEAST INTO CENTRAL TEXAS THIS MORNING. THEY THEN SPREAD TO THE SOUTH AND WEST ACROSS THE HILL COUNTRY AND SOUTH CENTRAL TEXAS THIS AFTERNOON AS OUTFLOW BOUNDARIES PROVIDE THE UPWARD FORCING FOR ADDITIONAL DEVELOPMENT. FORECAST SOUNDINGS AND CONVECTIVE PARAMETERS INDICATE STRONG WIND GUSTS ARE POSSIBLE. HIGH PWS INDICATE LOCALLY HEAVY DOWNPOURS WITH RAINFALL AMOUNTS UP TO ONE INCH OR SO ARE POSSIBLE. SHOWERS AND THUNDERSTORMS WANE WITH LOSS OF DAYTIME HEATING AFTER SUNSET AND SHOULD BE GONE BY MIDNIGHT. THE POOL OF MOISTURE BEGINS TO DRY FROM THE NORTHEAST AS IT DRIFTS TO THE WEST OVER SOUTH CENTRAL TEXAS ON WEDNESDAY. ONLY ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE. EACH OF MODELS APPEARS TO FAVOR A DIFFERENT AREA FOR QPF AND HAVE BROADBRUSHED THE SLIGHT CHANCES. DAYTIME TEMPERATURES CONTINUE TO BE ABOVE NORMAL. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)... MID TO UPPER LEVEL RIDGE SHIFTS TO A SOUTHWESTERN STATES INTO WESTERN TEXAS AXIS THURSDAY THROUGH SATURDAY AS A MID TO UPPER LEVEL SHORT WAVE RIDES OVER THE TOP OF IT INTO THE TROUGH OVER THE EASTERN STATES. THE POOL OF MOISTURE MOVES OFF TO THE WEST INTO MEXICO WITH PWS FALLING TO AN INCH OR LESS. NO RAIN IS EXPECTED THURSDAY THROUGH SATURDAY. AN INVERTED TROUGH PER GFS AND UPPER LOW PER ECMWF ARE FORECAST TO DEVELOP AND DRIFT TO THE WEST INTO TEXAS BY MONDAY. MOISTURE LEVELS WILL INCREASE LEADING TO SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS NEAR THE COASTAL PLAINS ON MONDAY. BEYOND THIS FORECAST...THE EVOLUTION OF THIS SYSTEM WILL DETERMINE RAIN CHANCES FOR THE MIDDLE TO END OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 100 75 98 73 98 / 30 20 20 - 0 AUSTIN BERGSTROM INTL AIRPORT 99 73 96 70 97 / 30 20 20 - 0 NEW BRAUNFELS MUNI AIRPORT 101 74 99 72 99 / 30 20 20 - 0 BURNET MUNI AIRPORT 97 73 96 72 97 / 30 20 20 - 0 DEL RIO INTL AIRPORT 101 76 101 77 101 / 20 20 20 10 0 GEORGETOWN MUNI AIRPORT 98 74 97 71 97 / 30 20 20 - 0 HONDO MUNI AIRPORT 100 73 99 72 98 / 20 20 20 10 0 SAN MARCOS MUNI AIRPORT 100 74 97 72 97 / 30 20 20 - 0 LA GRANGE - FAYETTE REGIONAL 99 74 96 71 97 / 30 20 20 - 0 SAN ANTONIO INTL AIRPORT 100 76 99 74 98 / 30 20 20 - 0 STINSON MUNI AIRPORT 100 76 99 73 99 / 30 20 20 - 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...24 SYNOPTIC/GRIDS...RUNYEN PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS TUCSON AZ
340 PM MST TUE AUG 25 2015 .SYNOPSIS...EXPECT SCATTERED THUNDERSTORMS THROUGH THURSDAY. ISOLATED TO SCATTERED THUNDERSTORMS WILL THEN PREVAIL MAINLY FROM TUCSON EAST AND SOUTH FRIDAY INTO EARLY NEXT WEEK. ABOVE NORMAL DAYTIME TEMPERATURES WILL ALSO OCCUR LATER THIS WEEK AND THIS WEEKEND. && .DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE OCCURRING ACROSS SE ARIZONA AT THIS TIME. IR SATELLITE IMAGERY INDICATED CLOUD TOPS WERE COOLING ACROSS THE AREA DURING THE PAST 1-2 HOURS. THE MOST SIGNIFICANT CLOUD TOP COOLING WAS ACROSS ERN PIMA COUNTY AND SOUTHEAST PINAL COUNTY. BASED ON RADAR/SATELLITE TRENDS AS WELL AS SEVERAL HRRR SOLUTIONS...POPS WERE CONFIGURED TO DEPICT SCATTERED TO NUMEROUS SHOWERS/TSTMS THIS EVENING. THE HIGHEST POPS ARE ACROSS WRN/CENTRAL PIMA COUNTY...SOUTH CENTRAL PINAL COUNTY AND THE WHITE MOUNTAINS. THE LOWEST POPS ARE ACROSS FAR SERN SECTIONS. HAVE MAINTAINED ISOLATED TO SCATTERED SHOWERS/TSTMS AREA- WIDE LATE TONIGHT INTO WED MORNING. HIGH PRESSURE ALOFT CENTERED NEAR THE FOUR CORNERS REGION THIS AFTERNOON IS PROGGED TO BECOME CENTERED OVER ERN NEW MEXICO/TEXAS PANHANDLE WED. THIS UPPER HIGH IS THEN PROGGED TO BECOME CENTERED OVER SRN ARIZONA FRI. SCATTERED SHOWERS/TSTMS SHOULD CONTINUE ACROSS MUCH OF THE AREA WED AFTERNOON/EVENING. SCATTERED SHOWERS/TSTMS WILL THEN PREVAIL MAINLY FROM TUCSON EWD/SWD THUR AFTERNOON/EVENING. THE COVERAGE OF SHOWERS/TSTMS WILL BE REDUCED FRI AS THE UPPER HIGH BECOMES POSITIONED OVER THE AREA. HOWEVER...THERE SHOULD BE ENOUGH MOISTURE TO MAINTAIN ISOLATED TO SCATTERED SHOWERS/TSTMS MAINLY EAST OF TUCSON FRI. 25/12Z GFS/ECMWF WERE THEN SIMILAR WITH DEPICTING SW-NE ORIENTED UPPER RIDGE AXIS TO BE OVER SE ARIZONA SAT-TUE. HOWEVER...THESE SOLUTIONS WERE SOMEWHAT MORE ROBUST WITH PROJECTED AVAILABLE MOISTURE VERSUS THEIR PREVIOUS SOLUTIONS. PER COORD WITH NEIGHBORING WFO/S...OPTED TO INCREASE THE INHERITED POPS SOMEWHAT...PARTICULARLY ACROSS ERN SECTIONS. THUS...ISOLATED TO SCATTERED SHOWERS/TSTMS MAINLY FROM TUCSON EWD/SWD WILL PREVAIL SAT-TUE. HAVE CONTINUED WITH PRECIP-FREE CONDITIONS ACROSS WRN PIMA COUNTY. A VERY GRADUAL DAILY WARMING TREND IS FORECAST TO OCCUR THRU SAT FOLLOWED BY A MODEST COOLING TREND SUN-TUE. && .AVIATION...VALID THRU 27/00Z. SCATTERED TO NUMEROUS -TSRA/-SHRA WILL OCCUR THIS EVENING FOLLOWED BY ISOLATED TO SCATTERED -TSRA/-SHRA LATE TONIGHT AND WEDNESDAY MORNING. SCATTERED -TSRA/-SHRA WILL THEN PREVAIL WEDNESDAY AFTERNOON. MVFR CONDITIONS AND BRIEF WIND GUSTS MAINLY TO 40 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL BE MAINLY LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SCATTERED THUNDERSTORMS WILL PREVAIL THROUGH THURSDAY. SOMEWHAT DRIER CONDITIONS WILL THEN PRODUCE ISOLATED TO SCATTERED THUNDERSTORMS MAINLY FROM TUCSON EAST AND SOUTH FRIDAY INTO EARLY NEXT WEEK. A WARMING TREND WILL OCCUR INTO SATURDAY WITH ABOVE NORMAL DAYTIME TEMPERATURES CONTINUING EARLY NEXT WEEK. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
955 AM MST TUE AUG 25 2015 .SYNOPSIS...SCATTERED THUNDERSTORMS WILL PREVAIL THROUGH WEDNESDAY. A DECREASE IN THUNDERSTORM CHANCES WILL THEN OCCUR STARTING THURSDAY AND ESPECIALLY BY THIS WEEKEND AS HIGH PRESSURE ALOFT BUILDS OVER THE AREA. A WARMING TREND WILL ALSO OCCUR DURING THE NEXT SEVERAL DAYS...WITH PERHAPS NEAR RECORD HIGH TEMPERATURES THIS WEEKEND. && .DISCUSSION...IR/VISIBLE SATELLITE IMAGERY INDICATES MOSTLY CLOUDY TO CLOUDY SKIES ACROSS SE ARIZONA AT THIS TIME. VISIBLE SATELLITE IMAGERY DEPICTED A CYCLONIC CIRCULATION FEATURE CENTERED IN NWRN SONORA NW OF HERMOSILLO...AND ANOTHER CYCLONIC CIRCULATION TWIST NEAR GLOBE AZ. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z WERE IN THE LOWER-MID 60S...AND 25/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 1.73 INCHES. THE 25/12Z KTWC SOUNDING ALSO DEPICTED FAIRLY STOUT GENERALLY SLY MID-LEVEL FLOW. 25/12Z UNIV OF AZ WRF-NAM AND SEVERAL HRRR SOLUTIONS WERE SIMILAR WITH DEPICTING SHOWERS/TSTMS TO DEVELOP GENERALLY ACROSS SEVERAL MOUNTAIN CHAINS SOUTH-TO-SOUTHEAST OF TUCSON BY AROUND 19Z. FAIRLY QUICK NORTH-TO-NORTHWEST STORM MOTIONS SHOULD THEN OCCUR THIS AFTERNOON AS PER THESE SOLUTIONS. HAVE OPTED TO INCREASE THE INHERITED GRIDDED DATA POPS FOR THIS AFTERNOON GENERALLY ABOUT 10-20 PERCENT BASED ON THESE SOLUTIONS AS WELL AS COORD WITH NEIGHBORING WFO/S. THUS...SCATTERED TO PERHAPS NUMEROUS SHOWERS/TSTMS SHOULD PREVAIL INTO THIS EVENING FOLLOWED BY ISOLATED SHOWERS/TSTMS LATE TONIGHT. THE MAIN CONCERN WITH SHOWERS/ TSTMS THIS AFTERNOON AND EVENING WILL BE THE POTENTIAL FOR HEAVY RAINFALL. HOWEVER...THE FAIRLY FAST STORM MOTIONS SHOULD MITIGATE THIS THREAT. A BRIEF STRONG WIND GUST OR SO MAY OCCUR...BUT THIS THREAT ALSO APPEARS TO BE FAIRLY MINIMAL. HIGH TEMPS THIS AFTERNOON ARE FORECAST TO GENERALLY BE ABOUT 3-8 DEGS F COOLER VERSUS MON. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 26/18Z. SCATTERED TO NUMEROUS -TSRA/-SHRA WILL OCCUR INTO TUESDAY MORNING. MVFR CONDITIONS AND BRIEF WIND GUSTS MAINLY TO 40 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL BE MAINLY LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL PREVAIL THROUGH WEDNESDAY. A REDUCTION IN THUNDERSTORM ACTIVITY WILL THEN OCCUR THURSDAY...THEN A SLIGHT CHANCE OF THUNDERSTORMS EXISTS MAINLY EAST OF TUCSON FRIDAY THROUGH SUNDAY. THE DRYING TREND WILL PRODUCE A WARMING TREND DURING THE LATTER PART OF THE WEEK...WITH NEAR RECORD HIGH TEMPERATURES POSSIBLE BY THIS WEEKEND. && .PREV DISCUSSION /346 AM MST/...BY WEDNESDAY THE HIGH SHOULD BE OVER THE TEXAS PANHANDLE WITH SOUTH TO SOUTHWEST FLOW ALOFT...WITH STILL PLENTY OF MOISTURE ACROSS THE REGION...WITH PW`S EXPECTED TO RANGE FROM AROUND 1 INCH TO THE EXTREME EAST AND 1.4-1.5 OVER CENTRAL LOCATIONS AND 1.5-1.7 FOR THE WEST. SO...POPS AGAIN SCATTERED IN NATURE FOR ALL BUT EXTREME WESTERN ZONES WHERE JUST ISOLATED. A SIMILAR FORECAST FOR THURSDAY. BY FRIDAY THE HIGH RETROGRADES TO A POSITION NEARLY OVERHEAD AND THIS CONTINUES ON SATURDAY. PW`S PROGGED TO BE 1.0 INCHES EAST...1.2 CENTRAL AND 1.4 WEST. THAT SAID...LOOKING AT MAINLY ISOLATED TO LOW END MAINLY MOUNTAIN STORMS BOTH DAYS FROM TUCSON EASTWARD. BY SUNDAY AND INTO MONDAY HIGH BECOMES ORIENTED SOUTHWEST TO NORTHEAST FROM CENTRAL BAJA ACROSS NORTHERN MEXICO AND INTO EASTERN NEW MEXICO AND WEST TEXAS. THIS IS IN RESPONSE TO AN UPSTREAM TROUGH AND MODELS SHOWING A SLIGHT MOISTURE PLUME ACROSS PARTS OF ARIZONA AND NEW MEXICO WITH AN UPTICK IN ACTIVITY BY MONDAY...MAINLY EAST. FOR TUCSON...HIGHS GENERALLY AT OR SLIGHTLY BELOW NORMAL TODAY... THEN NEAR NORMAL WEDNESDAY. THEREAFTER...HIGHS AROUND 4 TO 8 DEGS ABOVE NORMAL WITH THE WARMEST DAYS FRIDAY THROUGH SUNDAY. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
303 PM MDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 301 PM MDT TUE AUG 25 2015 AN UPR RIDGE REMAINS OVR THE AREA TODAY AND SO FAR THIS AFTERNOON...SHOWERS AND TSTMS HAVE BEEN CONFINED TO PORTIONS OF THE I-25 CORRIDOR...PALMER DVD AND WESTWARD. THE HRRR SHOWS THE POTENTIAL FOR SOME ISOLD SHOWERS/TSTMS TO ALSO DEVELOP OR MOVE OVER THE SERN PLAINS LATER THIS AFTERNOON AND THIS EVENING. MOST OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT...HOWEVER THE HRRR AND NAM SHOW THE POTENTIAL FOR SOME LINGERING ACTIVITY OVR THE SW MTNS THRU THE NIGHT. THE GFS ALSO SHOW SOME LINGERING ACTIVITY AFTER MIDNIGHT OVR THE ERN MTNS. ON WED THE UPR RIDGE REMAINS OVR THE AREA BUT A DISTURBANCE WL MOVE NORTH-NORTHEASTWARD FROM SWRN CO TO NORTH CENTRAL CO DURING THE DAY. THIS IS EXPECTED TO BRING AN INCREASE IN SHOWERS/TSTMS ACTIVITY TO THE CONTDVD. THE MAIN THREAT ALONG THE CONTDVD WL BE HEAVY RAIN...ESPECIALLY OVR THE BURN SCARS. OVR THE SERN PLAINS...DEW POINTS ARE EXPECTED TO ONLY BE IN THE UPPER 30S TO LOWER 40S WED AFTERNOON...AND CONDITIONS SHOULD GENERALLY BE DRY AND HOT AGAIN. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 301 PM MDT TUE AUG 25 2015 ...BEST CHANCE OF RAIN FROM WEDNESDAY NIGHT INTO THURSDAY... ...REST OF THE PERIOD MAINLY HOT AND DRY FOR THE LOWLANDS... ONLY REAL CONCERN IN THE EXTENDED IS WED EVENING...WHEN ONGOING STORMS OVER THE MTS COULD LEAD TO SOME LOCALIZED FLOODING CONCERNS...ESPECIALLY FOR THE BURN SCARS AND AREAS OF STEEP TERRAIN. COULD SEE SOME CONVECTION LINGER THROUGH THE NIGHT INTO THU MORNING. ONE MINOR TREND IN MODEL GUIDANCE IS THAT THERE SHOULD BE A SECONDARY UPPER DISTURBANCE THAT COMES THROUGH THURSDAY AFTERNOON OVER THE PLAINS...AND THIS MIGHT BRING A SLIGHTLY BETTER CHANCE FOR SOME AFTERNOON AND EVENING STORMS FOR THE PLAINS DURING THAT TIME. THE UPPER TROUGH DOES NOT REALLY CLEAR THE CWA UNTIL EARLY FRIDAY. SO WHILE IT STILL LOOKS TO BE FAIRY WARM THU...THERE SHOULD BE A LITTLE BETTER CHANCE OF STORMS...AND AFTER A COLD FRONT MOVES THROUGH THU EVENING IT WILL BE A FEW DEGREES COOLER ON FRI...OR RIGHT AROUND SEASONAL NORMS. REST OF THE EXTENDED FORECAST LOOKS PRETTY UNEVENTFUL. A PERSISTENT RIDGE WILL BE OVER THE DESERT SW...AND THIS WILL KEEP MOST OF THE CWA IN ABOVE AVERAGE TEMPERATURES AND WITH NO WIDESPREAD PRECIP. MOS GUIDANCE FOR THE EXTENDED AT KPUB FOR EXAMPLE IS WITHIN A COUPLE DEGREES FOR THE HIGH TEMPS THROUGH EARLY NEXT WEEK. SHOULD SEE LOWER 90S DOMINATE THE TEMPS FOR THE PLAINS DURING THIS TIME. THE MONSOON WILL BE PRESENT BUT DOES NOT LOOK TERRIBLY ACTIVE. WILL SEE DAILY CHANCES OF AFTERNOON-EVENING STORMS OVER THE MTN AREAS DURING THIS PERIOD. STILL A BIT UNCERTAIN HOW A PACNW TROUGH WILL EVOLVE OVER THE WEEKEND AND INTO NEXT WEEK...BUT MODEL CONSENSUS IS THAT IT WILL LIFT OFF TO THE E-NE OVER THE NRN ROCKIES AND CANADIAN PLAINS...SO THE IMPACT FOR OUR AREA LOOKS MINIMAL. ROSE && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 301 PM MDT TUE AUG 25 2015 VFR CONDITIONS ARE EXPECTED AT THE TAF SITE TONIGHT THROUGH WED AFTERNOON. THERE IS THE CHANCE FOR SOME SHOWERS/TSTMS IN THE VCNTY OF KCOS AND KALS THIS EVENING...AND MAYBE IN THE VCNTY OF KALS WED AFTERNOON. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...28 LONG TERM...ROSE AVIATION...28
AREA FORECAST DISCUSSION
NWS NEW YORK NY
358 PM EDT TUE AUG 25 2015 .SYNOPSIS... A WEAK COLD FRONT SLOWLY MOVES WITHIN THE REGION THIS EVENING...AND EXITS EAST OF THE REGION LATE TONIGHT. A LOW ALONG THE FRONT WILL HOVER NEAR NORTHERN COASTAL NEW ENGLAND WEDNESDAY. HIGH PRESSURE RETURNS FROM THE WEST WEDNESDAY NIGHT. HIGH PRESSURE THEN REMAINS OVER THE REGION THROUGH TUESDAY...BUT A COUPLE OF WEAK TROUGHS ALSO PASS THROUGH DURING THURSDAY AND AGAIN SUNDAY INTO SUNDAY NIGHT. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A COLD FRONT WILL SLOWLY APPROACH THIS EVENING. THE FRONT ONLY MAKES ITS WAY ACROSS NYC AND THE LOWER HUDSON VALLEY BY MID EVENING. THEN IT PROGRESSES EASTWARD ACROSS SOUTHERN CT AND THE REST OF LONG ISLAND GOING INTO THE OVERNIGHT PERIOD. POPS FOR SHOWERS AND THUNDERSTORMS REMAIN...BUT WITH A TREND LOWER COMPARED TO PREVIOUS FORECAST...LOWER THAN 50 PERCENT. THE DRIER AIR AS CONVEYED BY THE LOWER DEWPOINTS ACROSS NYC AND LOCATIONS NORTHWEST IS LOWERING THE INSTABILITY THERE AND DESPITE THE FRONT BEING RIGHT NEAR THAT LOCATION...CONVECTION IS MINIMAL. FARTHER EAST...THERE IS MORE INSTABILITY. RAP SOUNDINGS AT KISP FOR INSTANCE...STILL SHOW A LITTLE MORE THAN 1500 J/KG OF CAPE GOING INTO THE EARLY EVENING HOURS. THE POPS OVERALL INCREASE FARTHER EAST...SO ISOLATED CONVECTION AT MOST FOR LOCATIONS WEST OF LONG ISLAND AND SOUTHWEST CT. THE POPS WILL BE MORE SCATTERED FOR SOUTHEAST CT AND EASTERN LONG ISLAND WITH REGARDS TO CONVECTION THIS EVENING. DRIER AIR SHOULD TAKEOVER BY LATE EVENING...WITH MAINLY DRY CONDITIONS PREVAILING THEREAFTER. A LACK OF UPPER LEVEL FORCING WITH LESS PVA IS PROVING TO KEEP CONVECTION AT A LOWER COVERAGE AND THIS MAY VERY WELL CONTINUE GOING INTO THE EVENING. THE LOWS OVERNIGHT WERE A BLEND OF MET AND ECS...WHICH SHOWED VERY GOOD AGREEMENT. THESE VALUES WILL BE IN THE MID 50S TO MID 60S FOR MOST LOCATIONS...AND UPPER 60S WITHIN NYC. THERE IS A MODERATE RISK FOR RIP CURRENT DEVELOPMENT AT ATLANTIC OCEAN BEACHES INTO THIS EVENING. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... THERE IS LITTLE PROGRESSION IN THE WEATHER PATTERN WEDNESDAY. THE FRONT WEAKENING EAST OF THE REGION WILL HAVE A WEAK LOW HOVERING ALONG IT IN NORTHERN COASTAL NEW ENGLAND. THE LOW EVENTUALLY WILL BECOME WASHED OUT AND MORE A PART OF THE MEAN FLOW. THE RELATIVE MORE PROMINENT FEATURE WILL BE HIGH PRESSURE SLOWLY BUILDING IN FROM THE WEST. THE HIGH TO THE WEST WILL GIVE THE REGION A MORE WESTERLY FLOW THROUGH THE DAY. SEA BREEZES SHOULD STAY CLOSE TO SOUTH COASTAL LOCATIONS WITHOUT MUCH NORTHWARD PROGRESS. DEWPOINTS WILL BE REMARKABLY LOWER...IN THE MID 50S FOR MOST LOCATIONS. OVERALL...TEMPERATURES AT THE SURFACE WILL TREND A FEW DEGREES LOWER THAN THE PREVIOUS DAY. THIS WILL BE DUE TO COLD AIR ADVECTION AS WINDS BACK FROM THE LOWER TO MID LEVELS. WEDNESDAY NIGHT WILL HAVE STRONGER EFFECTS FROM THE HIGH PRESSURE BUILDING IN. THE SUBSIDENCE WILL ALLOW FOR MOSTLY CLEAR SKIES AND WITH LIGHT WINDS...RADIATIONAL COOLING WILL LEAD TO TEMPERATURES BEING A FEW DEGREES LOWER AS WELL COMPARED TO THE PREVIOUS NIGHT. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGH PRESSURE WILL BE THE DOMINANT SURFACE FEATURE ON THURSDAY...BUT A WEAK TROUGH COULD DEVELOP OVER THE EASTERN ZONES AS A TROUGH AXIS ALOFT SHIFTS THROUGH. LOOKS LIKE ONLY DIURNAL CU RESULTS GIVEN THE AVAILABLE MOISTURE...AND PROBABLY MORE COVERAGE OVER THE NORTHERN ZONES VERSUS THE SOUTHERN. MAV/NAM MOS BLEND SEEMED CONSISTENT WITH MIXING DOWN FROM 850MB FOR HIGH TEMPS. DRIER AIR SHIFTS IN ON FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE WEST AND DEEP-LAYERED RIDGING. TEMPS SHOULD BE FAIRLY SIMILAR TO THOSE ON THURSDAY...NEAR NORMAL. SLIGHT RIDING ALOFT CONTINUES ON SATURDAY BEFORE FLATTENING FOR SUNDAY. MEANWHILE...THE SURFACE HIGH CENTER SHIFTS OFFSHORE...AND MODELS SEEM TO NOW AGREE THAT A WEAK COLD FRONT OR TROUGH SHIFTS THROUGH SOMETIME SUNDAY AFTERNOON OR SUNDAY NIGHT. GFS CONTINUES TO BE THE OUTLIER IN BEING AGGRESSIVE WITH RETURN-FLOW MOISTURE AND APPARENT CONVECTIVE FEEDBACK BOTH DAYS. WILL THEREFORE CONTINUE TO KEEP A DRY FORECAST THROUGH THE WEEKEND...ALTHOUGH POPS MIGHT EVENTUALLY BE NEEDED IN THE GRIDS SUNDAY AFTN/NIGHT. HIGH TEMPS A FEW DEGREES ABOVE NORMAL THIS WEEKEND. HIGH PRESSURE REMAINS OFFSHORE ON MONDAY...AND WITH MODELS AGREEING ON RIDING ALOFT...WILL REMOVE SLIGHT CHC POPS FOR MONDAY AND MONDAY NIGHT. RIDGING CONTINUES ALOFT ON TUESDAY...AND FOR NOW IT APPEARS THAT IT REMAINS DRY...BUT WILL NEED TO MONITOR FOR ANY CHANGES IN MOISTURE SURGE AND CONVECTIVE TRIGGERS. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... COLD FRONT WILL MOVE ACROSS THE TERMINALS THIS EVENING FOLLOWED BY HIGH PRESSURE BUILDING THROUGH WEDNESDAY. VFR THROUGH THE FORECAST PERIOD. THE ONLY EXCEPTION IS DURING THE NEXT HOUR OR SO AT KISP WHERE MVFR CIG HAS DEVELOPED. THIS SHOULD IMPROVE BACK TO VFR IN THE 21-22Z TIME FRAME. OTHER THAN AT KSWF...WINDS WILL BE S-SE 10 TO 15 KT AHEAD OF THE FRONT FOR THE REMAINDER OF THE AFTERNOON. FROPA PASSAGE THIS EVENING WILL SHIFT WINDS TO THE W AND NW WITH SLOWLY DIMINISHING SPEEDS OVERNIGHT. AN ISO SHRA/TSRA CANNOT BE RULED OUT INTO THIS EVENING...MAINLY EAST OF NYC METRO TERMINALS. W-NW WINDS 5-10 KT WILL CONTINUE ON WEDNESDAY 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 WIND SHIFT WITH COLD FROPA COULD BE OFF BY +/- 2 TO 3 HOURS. OCCASIONAL GUSTS UP TO 20 KT THROUGH 22Z. KLGA FCSTER COMMENTS: TIMING OF WIND SHIFT WITH COLD FROPA COULD BE OFF BY +/- 2 TO 3 HOURS. OCCASIONAL GUSTS UP TO 20 KT POSSIBLE THROUGH 22Z. KEWR FCSTER COMMENTS: TIMING OF WIND SHIFT WITH COLD FROPA COULD BE OFF BY +/- 2 TO 3 HOURS. OCCASIONAL GUSTS UP TO 20 KT THROUGH 22Z. KTEB FCSTER COMMENTS: TIMING OF WIND SHIFT WITH COLD FROPA COULD BE OFF BY +/- 2 TO 3 HOURS. OCCASIONAL GUSTS UP TO 20 KT THROUGH 22Z. KHPN FCSTER COMMENTS: TIMING OF WIND SHIFT WITH COLD FROPA COULD BE OFF BY +/- 2 TO 3 HOURS. KISP FCSTER COMMENTS: TEMPO MVFR CIG COULD LAST AN HOUR LONGER THAN FORECAST. TIMING OF WIND SHIFT WITH COLD FROPA COULD BE OFF BY +/- 2 TO 3 HOURS. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... .WEDNESDAY AFTERNOON THROUGH SATURDAY...VFR. MORNING W/NW FLOW GIVING WAY TO AFTERNOON W/SW FLOW AND COASTAL SEA BREEZES. .SUNDAY...VFR. && .MARINE... THE COLD FRONT MOVES ACROSS THE WATERS LATE TONIGHT WITH WEAK HIGH PRESSURE BUILDING IN WEDNESDAY INTO WEDNESDAY NIGHT. THE PRESSURE GRADIENT REMAINS WEAK ENOUGH TO KEEP BELOW SCA CONDITIONS THROUGH THE PERIOD. GUSTS UP TO 20 KT WILL DIMINISH OVERNIGHT AND WILL BE MINIMAL THROUGH WEDNESDAY NIGHT. EXPECT SUB SCA CONDITIONS FOR THE REST OF THE FORECAST PERIOD AS A RELATIVELY WEAK PRESSURE GRADIENT REMAINS OVER THE WATERS. && .HYDROLOGY... RAINFALL AMOUNTS IN ISOLATED TO SCATTERED CONVECTION WILL AVERAGE LESS THAN A QUARTER OF AN INCH THROUGH THIS EVENING. MINOR URBAN OR POOR DRAINAGE FLOODING WOULD BE THE MAIN THREAT BUT THE SPEED OF THE THUNDERSTORMS...THIS IS LOOKING TO BE OF CONTINUING LOWERING POSSIBILITY. NO SIGNIFICANT WIDESPREAD RAINFALL IS EXPECTED THROUGH EARLY NEXT WEEK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JC/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...JC AVIATION...DS MARINE...JC/JM HYDROLOGY...JC/JM
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1209 PM CDT TUE AUG 25 2015 .UPDATE... ISSUED AT 945 AM CDT TUE AUG 25 2015 RATHER COOL START TO THE DAY...WITH SEVERAL LOCATIONS FALLING BELOW 50 DEGREES. TEMPERATURES REBOUNDING NICELY THIS MORNING WITH SUNSHINE PREVAILING...MAINLY IN THE LOWER TO MID 60S AT 9 AM. AS THE UPPER LOW CONTINUES TO SPIN OVER EASTERN ONTARIO...THE LARGE STRATOCUMULUS SHIELD EXTENDING SOUTH ACROSS THE GREAT LAKES WILL EDGE INTO THE NORTHERN PARTS OF THE FORECAST AREA LATER THIS MORNING. THE EXISTING FORECAST HAD THESE ASPECTS UNDER CONTROL...AND LITTLE CHANGE WAS NEEDED. && .SHORT TERM...(TODAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 DEEP UPPER TROF FOR LATE AUGUST SITUATED JUST NORTH OF LAKE HURON EARLY THIS MORNING IS FORECAST TO SLOWLY EDGE EAST OVER THE NEXT FEW DAYS. MEANWHILE...SEVERAL WEAK SHORTWAVES ROTATING SOUTHEAST INTO THE LOWER GREAT LAKES WITH ONE SUCH FEATURE NOW PUSHING ACROSS SOUTH CENTRAL LAKE MICHIGAN. THIS WAVE MAY HAVE BEEN RESPONSIBLE FOR PUSHING THE STRATOCUMULUS DECK A BIT FURTHER SOUTH THAN ANTICIPATED LATE YESTERDAY THROUGH EARLY THIS MORNING. AS THE WEAK UPPER LEVEL DISTURBANCE PUSHES FURTHER OFF TO OUR EAST WE SHOULD SEE THE CLOUD DECK CONTINUE THIN OUT ACROSS OUR NORTHERN COUNTIES. HOWEVER, ADDITIONAL PIECES OF ENERGY ARE SEEN ROTATING SOUTHWARD AROUND THE LARGE UPPER LOW AND THAT COMBINED WITH DAYTIME HEATING MAY LEAD TO A LEAST SOME SCATTERED CLOUD COVER ACROSS THE NORTH LATER THIS MORNING INTO THE AFTERNOON HOURS. RAP FORECAST SOUNDINGS ONCE AGAIN INDICATING SOME STEEP LOW AND MID LEVEL LAPSE RATES ASSOCIATED WITH THE BROAD CYCLONIC FLOW OVER THE REGION WHICH WILL LEAD TO SOME GUSTY WEST TO NORTHWEST WINDS LATE THIS MORNING THRU THIS AFTERNOON. 850 MB TEMPS A FEW DEGREES COOLER THAN WHAT WE HAD AROUND OUR AREA YESTERDAY WHICH SHOULD PRODUCE AFTERNOON HIGHS MOSTLY IN THE MIDDLE 70S. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 312 AM CDT TUE AUG 25 2015 QUIET FORECAST AT LEAST UNTIL THE END OF THE WORK WEEK WITH HIGH TEMPS SLIGHTLY BELOW NORMAL, BUT SLOWLY WARMING THROUGH THE END OF THE WEEK AHEAD OF THE NEXT SYSTEM. OVERNIGHT LOWS ALSO ON THE COOL SIDE AT LEAST UNTIL THE CLOUDS INCREASE SOMEWHAT AHEAD OF THE NEXT SYSTEM THURSDAY NIGHT IN THE NORTHWEST. PRECIP ASSOCIATED WITH THE UPPER LEVEL WAVE, HOWEVER, NOT ANTICIPATED TO IMPACT CENTRAL ILLINOIS UNTIL FRIDAY NIGHT/SATURDAY MORNING. SOME SLIGHT CHANCES CREEPING INTO NW OF THE ILLINOIS RIVER VALLEY FOR FRIDAY, WITH CHANCES INCREASING THROUGH THE OVERNIGHT AND INTO SAT MORNING. UPPER LEVEL DISTURBANCE IS DIFFUSE AND SLOW MOVING IN BOTH THE GFS AND THE ECMWF. THE NAM IS STARTING TO COME IN A LITTLE MORE COMPACT AND QUICKER, SO NOT OVERLY CONFIDENT WITH ANY PARTICULAR SOLUTION. THE GFS AND ECMWF HAVE BEEN BACK AND FORTH ENOUGH OVER THE LAST SEVERAL SYNOPTIC RUNS THAT CONSENSUS IS WEAK. ALSO NOT INCLINED TO LEAVE CHANCE POPS IN THE FORECAST ALL THE WAY THROUGH THE WEEKEND WITH THAT SLOW OF A SYSTEM. FOR NOW, WILL KEEP THE CONCENTRATION TO SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1209 PM CDT TUE AUG 25 2015 LITTLE CHANGE REQUIRED TO EXISTING TAF SET. SOME SCATTERED DIURNAL CUMULUS STARTING TO FORM AROUND 4000 FEET FROM KPIA-KHUF... BUT THE MAIN AREA OF CEILINGS STILL IN NORTHERN ILLINOIS AND THE GREAT LAKES...ASSOCIATED WITH LARGE UPPER LOW OVER EASTERN ONTARIO. SOME ADDITIONAL DEVELOPMENT ON THE SOUTHERN FLANK IS OCCURRING... SO SOME BRIEF CEILINGS POSSIBLE KPIA-KCMI CANNOT BE RULED OUT FOR THE NEXT FEW HOURS. CLOUDS EXPECTED TO FADE AWAY WITH SUNSET. WINDS HAVE BEEN GUSTING FROM 12-18 KNOTS AT MOST SITES RECENTLY... AND THIS SHOULD CONTINUE THROUGH LATE MORNING BEFORE SETTLING BACK DOWN. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEELHART SHORT TERM...SMITH LONG TERM...HJS AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
232 PM MDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 201 PM MDT TUE AUG 25 2015 EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS CENTRAL ROCKIES. A PLUME OF MONSOONAL MOISTURE IS ROTATING FROM THE FOUR CORNERS REGION ROTATING INTO THE CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE ACROSS EASTERN COLORADO WITH MAIN AXIS EXTENDING ACROSS SE COLORADO INTO SW KANSAS. THIS AFTERNOON-EVENING...CONVECTIVE INITIATION WILL MAINLY BE ALONG TROUGH AXIS AND ALONG HIGHER TERRAIN IN COLORADO (WEST OF OUR CWA. CURRENTLY VERY HIGH CINH IS PREVENTING LOCAL INITIATION...HOWEVER CAP SHOULD WEAKEN ACROSS WESTERN PARTS OF THE CWA WHERE ISOLATED THUNDERSTORMS WILL BE POSSIBLE. THE AREAS WHERE CAP IS MOST LIKELY TO BREAK ALSO CORRELATE WITH LOWEST CAPE/DRIEST AIR MASS...SO COVERAGE IS LIMITED. BEYOND A VERY SMALL THREAT FOR DRY MICROBURST POTENTIAL...CONFIDENCE IN ANY SEVERE THREAT IS LOW. WEDNESDAY...THERE IS A STRONGER PRECIP SIGNAL THAN TODAY FROM SOME GUIDANCE...HOWEVER SOUNDING ACTUALLY SHOW AN EVEN DRIER AIR MASS AND STRONGER CAP THAN TODAY. VERY HOT AIR MASS WILL SUPPORT HIGHS APPROACHING 100F OVER PARTS OF THE CWA...AND DRY ADIABATIC MIXING MAY SUPPORT RH VALUES AND WINDS NEAR RED FLAG THRESHOLDS. WILL NEED TO MONITOR...PARTICULARLY IN THE WESTERN PART OF THE CWA. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 229 PM MDT TUE AUG 25 2015 A RIDGE WILL RESIDE OVER THE ROCKIES/PLAINS THROUGH FRIDAY. HOWEVER, A SHORTWAVE TROUGH WILL MOVE THROUGH THE RIDGE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THE RIDGE WILL REBUILD OVER THE ROCKIES FRIDAY. A SURFACE TROUGH WILL BE OVER EASTERN COLORADO WEDNESDAY NIGHT AND THEN MOVES EAST ACROSS NORTHWEST KANSAS THURSDAY AND THURSDAY NIGHT. HIGH PRESSURE WILL BUILD INTO NORTHWEST KANSAS BEHIND THE EXITING TROUGH ON FRIDAY. GFS AND NAM MOISTURE IS SLOW MOVING AND STAYS MOSTLY TO THE NORTH AND WEST OF THE FA LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THE GFS INDICATES THE POSSIBILITY OF SOME FORCING AND MOISTURE TO IMPACT THE FA AFTER 06Z THURSDAY AND THEN MOVE ACROSS THE REST OF THE FA THURSDAY. CAPE VALUES ARE LOW SO PRECIPITATION SHOULD BE AS SHOWERS WITH ISOLATED THUNDERSTORMS. MOISTURE AND DYNAMICS MOVE OUT OF THE FA EARLY FRIDAY MORNING. PLAN TO GO WITH SLIGHT CHANCE POPS LATE WEDNESDAY NIGHT/EARLY THURSDAY MORNING. CHANCE POPS LOOK ON TRACK FOR THURSDAY WITH DECREASING POPS FROM WEST TO EAST THURSDAY NIGHT. NIL POPS ARE ON TRACK FOR FRIDAY AS HIGH PRESSURE AND SUBSIDENCE MOVES INTO THE FA. MIN TEMPERATURES SHOULD COOL TO THE MID AND UPPER 60S ACROSS MOST OF THE FA WEDNESDAY NIGHT WITH NEAR 70 IN THE EAST. MIN TEMPERATURES THURSDAY NIGHT WILL BE COOLER WITH READINGS IN THE UPPER 50S IN EASTERN COLORADO TO AROUND 65 IN THE FAR EASTERN FA. MAX TEMPERATURES THURSDAY SHOULD WARM TO THE UPPER 80S/LOWER 90S. READINGS ON FRIDAY SHOULD BE COOLER IN THE MID 80S. IN THE EXTENDED...(FRIDAY NIGHT THROUGH TUESDAY)... A RIDGE OVER THE ROCKIES AND PLAINS WILL KEEP THE WEATHER DRY ACROSS THE FA THROUGH MONDAY. THE RIDGE SHIFTS EAST AND MONSOONAL MOISTURE MOVES UP THE WEST SIDE OF THE RIDGE TO PROVIDE AT LEAST A SLIGHT CHANCE OF PRECIPITATION OVER EASTERN COLORADO MONDAY NIGHT AND TUESDAY. MIN TEMPERATURES WILL RANGE FROM THE UPPER 50S TO AROUND 60 FRIDAY AND SATURDAY NIGHTS AND THE LOWER TO MID 60S SUNDAY AND MONDAY NIGHTS. MAX TEMPERATURES SHOULD WARM TO THE UPPER 80S/LOWER 90S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1139 AM MDT TUE AUG 25 2015 VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. SOME GUIDANCE IS INDICATING MVFR CIGS/VIS DEVELOPING SOUTH OF INTERSTATE 70...POSSIBLY IMPACTING THE KGLD TERMINAL. CONFIDENCE IS TOO LOW AT THIS TIME TO INCLUDE MENTION...AND TREND WILL BE FOR BETTER MOISTURE TO SHIFT EAST OF THE TERMINAL THROUGH THE NIGHT. SOUTHEAST WINDS GENERALLY 10-12KT WILL DECREASE TONIGHT AS SURFACE LOW MOVES EAST. SURFACE GRADIENT INCREASES WEDNESDAY...AND WILL SUPPORT GUSTY WINDS DEVELOPING AT THE END OF THE TAF PERIOD AT KGLD AND OUTSIDE THE TAF PERIOD AT KMCK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
201 PM MDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 201 PM MDT TUE AUG 25 2015 EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS CENTRAL ROCKIES. A PLUME OF MONSOONAL MOISTURE IS ROTATING FROM THE FOUR CORNERS REGION ROTATING INTO THE CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE ACROSS EASTERN COLORADO WITH MAIN AXIS EXTENDING ACROSS SE COLORADO INTO SW KANSAS. THIS AFTERNOON-EVENING...CONVECTIVE INITIATION WILL MAINLY BE ALONG TROUGH AXIS AND ALONG HIGHER TERRAIN IN COLORADO (WEST OF OUR CWA. CURRENTLY VERY HIGH CINH IS PREVENTING LOCAL INITIATION...HOWEVER CAP SHOULD WEAKEN ACROSS WESTERN PARTS OF THE CWA WHERE ISOLATED THUNDERSTORMS WILL BE POSSIBLE. THE AREAS WHERE CAP IS MOST LIKELY TO BREAK ALSO CORRELATE WITH LOWEST CAPE/DRIEST AIR MASS...SO COVERAGE IS LIMITED. BEYOND A VERY SMALL THREAT FOR DRY MICROBURST POTENTIAL...CONFIDENCE IN ANY SEVERE THREAT IS LOW. WEDNESDAY...THERE IS A STRONGER PRECIP SIGNAL THAN TODAY FROM SOME GUIDANCE...HOWEVER SOUNDING ACTUALLY SHOW AN EVEN DRIER AIR MASS AND STRONGER CAP THAN TODAY. VERY HOT AIR MASS WILL SUPPORT HIGHS APPROACHING 100F OVER PARTS OF THE CWA...AND DRY ADIABATIC MIXING MAY SUPPORT RH VALUES AND WINDS NEAR RED FLAG THRESHOLDS. WILL NEED TO MONITOR...PARTICULARLY IN THE WESTERN PART OF THE CWA. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 116 AM MDT TUE AUG 25 2015 RIDGE REMAINS FIRMLY IN PLACE FRIDAY THROUGH TUESDAY HOWEVER A SLOW MOVEMENT TO THE EAST IS EXPECTED TOWARD THE END OF THE FORECAST PERIOD. A FEW LINGERING SHOWERS WILL MAKE THEIR WAY EAST ON FRIDAY MORNING IN THE WAKE OF THURSDAYS TROUGH OF LOW PRESSURE. THE RIDGE WILL THEN BUILD BACK IN LATER ON FRIDAY AND INTO SATURDAY WITH DRY WEATHER EXPECTED FOR FRIDAY AFTERNOON THROUGH MONDAY. A LEE SIDE LOW PRESSURE AREA WILL DEEPEN INTO A WEAK 700MB TROUGH AS WE HEAD INTO TUESDAY. RAIN AND THUNDERSTORM CHANCES WILL BECOME A POSSIBILITY ONCE MORE MAINLY DURING THE LATE AFTERNOON TUESDAY. BOTH THE ECMWF AND GFS ARE IN VERY CLOSE AGREEMENT WITH REGARDS TO THE OVERALL STRUCTURE AND TEMPORAL EVOLUTION OF THE HIGH THROUGH THE ENTIRE FORECAST PERIOD... AS WELL AS THE EVENTUAL MOVEMENT TOWARD THE EAST. TEMPERATURES DURING THE FORECAST PERIOD WILL LIKELY BE AROUND TO JUST ABOVE THE SEASONAL AVERAGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1139 AM MDT TUE AUG 25 2015 VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. SOME GUIDANCE IS INDICATING MVFR CIGS/VIS DEVELOPING SOUTH OF INTERSTATE 70...POSSIBLY IMPACTING THE KGLD TERMINAL. CONFIDENCE IS TOO LOW AT THIS TIME TO INCLUDE MENTION...AND TREND WILL BE FOR BETTER MOISTURE TO SHIFT EAST OF THE TERMINAL THROUGH THE NIGHT. SOUTHEAST WINDS GENERALLY 10-12KT WILL DECREASE TONIGHT AS SURFACE LOW MOVES EAST. SURFACE GRADIENT INCREASES WEDNESDAY...AND WILL SUPPORT GUSTY WINDS DEVELOPING AT THE END OF THE TAF PERIOD AT KGLD AND OUTSIDE THE TAF PERIOD AT KMCK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...TL AVIATION...DR
AREA FORECAST DISCUSSION
NWS JACKSON KY
117 PM EDT TUE AUG 25 2015 .UPDATE... ISSUED AT 1003 AM EDT TUE AUG 25 2015 UPDATED NDFD HOURLY TEMPERATURE AND DEWPOINTS BASED ON LATEST OBSERVATIONAL TRENDS AND REMOVED THE MORNING FOG FROM THE ZFP. UPDATE ISSUED AT 720 AM EDT TUE AUG 25 2015 DID A QUICK UPDATE TO THE GRIDS USING THE LATEST OBS AND TRENDS FOR THE T AND TD GRIDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM EDT TUE AUG 25 2015 06Z SFC ANALYSIS SHOWS A LARGE AREA OF COOL AND DRY HIGH PRESSURE BUILDING INTO THE OHIO VALLEY FROM THE NORTHWEST. THIS HAS KEPT THE SKIES MOSTLY CLEAR DURING THE NIGHT AND ALLOWED FOR A GOOD NIGHT OF RADIATIONAL COOLING BELOW THE INVERSION. AS IS TYPICAL... THIS HAS RESULTED IN A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT RANGING FROM THE MID 50S IN SHELTERED LOCATIONS TO THE LOWER 60S ON THE RIDGES. DEWPOINTS MEANWHILE ARE IN THE LOW TO MID 50S ACROSS THE CWA WITH LIGHT WINDS FROM THE WEST ABOVE THE INVERSION. JUST A HINT OF VALLEY FOG IS NOTED IN THE MONTICELLO OBSERVATION AND IN SOME OF THE WEB CAMS. THE MODELS REMAIN IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THE ALL ARE VERY SIMILAR WITH THE DEEP... AND CLOSED...LOW SLOWLY MOVING INTO SOUTHEAST CANADA AND THE EASTERN GREAT LAKES TODAY THROUGH WEDNESDAY. THIS WILL PLACE THE OHIO VALLEY AND KENTUCKY IN THE MIDST OF LOW HEIGHTS WHILE WEAK PACKETS OF ENERGY MOVE BY AT MID LEVELS IN BROAD NORTHWEST FLOW. GIVEN THE MINUSCULE MODEL SPREAD WILL USE A GENERAL BLEND SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12. CAPITAL WEATHER WILL BE THE RULE THROUGH THE SHORT TERM WITH MINIMAL CLOUDS...LOW AFTERNOON HUMIDITIES...AND COOL NIGHTS. THE SFC HIGH PRESSURE WILL SPREAD OVER KENTUCKY AND KEEP THE BULK OF ANY CLOUDS...ASSOCIATED WITH THE PASSING UPPER LOW...TO A MINIMUM. HIGHS WILL END UP IN THE MID 70S FOR MOST SPOTS TODAY AND WEDNESDAY. AT NIGHT...LOOK FOR A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP IN CONJUNCTION WITH AN INVERSION SETTING UP. CANNOT RULE OUT PATCHY FOG IN THE MORE SHELTERED LOCATIONS TOWARDS DAWN THIS MORNING AND AGAIN ON WEDNESDAY MORNING. THE COOL AIR MAY SET A RECORD LOW TONIGHT AT JKL...CURRENTLY A MILD 58 DEGREES FROM 1984...BUT PROBABLY LOZ/S 46 DEGREE RECORD FROM 1966 WILL STAY OUT OF REACH. AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THIS EVENING BEFORE INITIATING WITH THE SUPERBLEND INTO WEDNESDAY EVENING. DID MAKE SOME DECENT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEN EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD... IN LINE WITH MOS GUIDANCE. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 333 AM EDT TUE AUG 25 2015 SFC HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL PROVIDE US WITH PLEASANT WEATHER FOR THE BEGINNING OF THE EXTENDED PERIOD. HOWEVER THIS WILL BE SHORT LIVED AS THE HIGH IS EXPECTED TO MOVE OFF TO THE EAST BY SATURDAY. THIS WILL ALLOW FOR WEAK RETURN FLOW TO USHER IN LL MOISTURE...HIGHER DEWPOINTS AND WARMER TEMPERATURES FOR THE WEEKEND. AN UPPER LEVEL SHORTWAVE AND ASSOCIATED FRONT WILL APPROACH THE AREA FROM THE PLAINS...BRINGING RENEWED CHANCES FOR PRECIP EACH AFTERNOON SATURDAY THROUGH MONDAY. THE BEST CHANCE FOR MEASURABLE PRECIP WILL LIKELY BE ON MONDAY AS THE UPPER LEVEL WAVE MOVES THROUGH OUR REGION. HOWEVER...THERE ARE SOME DIFFERENCES ON HOW THE MODELS HANDLE THIS UPPER LEVEL FEATURE...WHICH WILL ULTIMATELY DETERMINE HOW MUCH PRECIP WE COULD GET. SO FOR NOW HAVE STUCK CLOSE TO THE CR SUPERBLEND AND MAINTAINED SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES WILL BEGIN BELOW NORMAL ON THURSDAY BUT THEN GRADUALLY WARM THROUGH THE REST OF THE EXTENDED PERIOD WITH HIGHS RETURNING TO THE MID TO UPPER 80S BY MONDAY. HUMIDITY WILL FOLLOW THE SAME TREND...WITH DEWPOINTS INCREASING INTO THE MID 60S BY SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 117 PM EDT TUE AUG 25 2015 HIGH PRESSURE NOSING EAST FROM THE MS VALLEY WILL CONTINUE TO CONTROL THE WEATHER ACROSS EASTERN KY...WITH VFR CONDITIONS PREVAILING. SCATTERED TO BROKEN CLOUD AROUND 5K FEET WILL PREVAIL THROUGH THE REMAINDER OF THE AFTERNOON...AND SIMILAR CONDITIONS ARE EXPECTED AGAIN WEDNESDAY AFTERNOON. CLOUDS WILL DIMINISH TONIGHT AND FOG IS EXPECTED TO FORM LATE TONIGHT...MAINLY IN RIVER VALLEYS AND NEAR STREAMS AND LAKES. FOG AND LOW CEILINGS ARE EXPECTED TO IMPACT SME FOR A FEW HOURS AROUND DAYBREAK WEDNESDAY. FOG IS NOT EXPECTED AT THE OTHER TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...JVM AVIATION...SBH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 411 PM EDT TUE AUG 25 2015 LATEST WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP MID LEVEL LOW CENTERED N OF GEORGIAN BAY DRIFTING EASTWARD. TO THE W...A RIDGE EXTENDS FROM THE SRN ROCKIES N INTO SASKATCHEWAN/MANITOBA. IN THE LINGERING MOIST...CYCLONIC FLOW AROUND THE MID LEVEL LOW...SOME -SHRA/-DZ HAVE PERSISTED ACROSS THE FCST AREA TODAY...AIDED BY NW UPSLOPE FLOW. THERE HAS PROBABLY BEEN SOME LAKE COMPONENT TO THE PCPN AS WELL. WITH CLOUD TOPS WARMING OVER THE LAST SEVERAL HRS PER IR IMAGERY...RADAR HAS SHOWN PCPN COVERAGE/INTENSITY DIMINISHING. UNDER AN OVC CLOUD COVER...IT HAS BEEN ANOTHER UNSEASONABLY COOL DAY FOR LATE AUG. SO FAR...TEMPS HAVE ONLY RISEN TO THE LOW/MID 50S IN THE HIGHER TERRAIN AND WHERE PCPN LINGERS TO AROUND 60 OVER THE FAR SCNTRL. BACK EDGE OF THE CLOUD COVER EXTENDS ROUGHLY FROM DULUTH TO INTERNATIONAL FALLS AND NORTHWARD. AS MID LEVEL LOW AND UPSTREAM RIDGE DRIFT E...EXPECT IMPROVING CONDITIONS DURING THE SHORT TERM PORTION OF THE FCST. MAIN FCST ISSUES WILL BE TIMING THE ENDING OF PCPN AND THE CLEARING TREND. UNDER SLOW HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE AND WEAKENING CYCLONIC FLOW...LINGERING -SHRA/-DZ WILL CONTINUE TO DIMINISH TONIGHT. THIS TREND WILL BE MOST PRONOUNCED OVER THE W...WHERE THE LOW-LEVEL FLOW BECOMES MORE ANTICYCLONIC CLOSER TO APPROACHING SFC HIGH PRES SETTLING OVER MN. LINGERING LOW CLOUDS WILL LIMIT TEMP FALL TONIGHT. EXPECT THE LOWEST MINS (TOWARD THE MID 40S) OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLEARING LATE. IF THERE IS SOME CLEARING...PATCHY FOG COULD DEVELOP. A FEW -SHRA/PATCHY -DZ MAY CONTINUE TO LINGER INTO THE NCNTRL/ERN FCST AREA WED MORNING UNDER ABUNDANT LOW-LEVEL MOISTURE. WITH NEUTRAL TO VERY WEAKLY CYCLONIC LOW-LEVEL FLOW AND AIR MASS TOO WARM FOR LAKE EFFECT PROCESSES...ANY PCPN WILL BE VERY LIGHT. OTHERWISE...APPROACHING HIGH PRES WILL SETTLE OVER UPPER MI BY WED EVENING. MODELS SUGGEST CLEARING WILL ONLY SLOWLY PUSH E ACROSS THE FCST AREA AS THE HIGH ARRIVES AND THERMAL TROF DEPARTS. LARGELY UTILIZED A MODEL CONSENSUS TO CONSTRUCT THE SKY COVER AND THE W TO E CLEARING TREND ON WED. IT MAY NOT BE UNTIL TOWARD SUNSET THAT THE LAST OF THE CLOUDS CLEAR THE ERN FCST AREA. UNDER INCREASING SUNSHINE AND DEPARTURE OF THERMAL TROF...TEMPS WILL BEGIN TO REBOUND. EXPECT HIGHS AROUND 60/LWR 60S E WHERE CLOUDS LINGER LONGEST TO THE UPPER 60S TOWARD THE MI/WI BORDER. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 301 PM EDT TUE AUG 25 2015 GOOD AGREEMENT IN OVERALL LOOK OF LARGE SCALE PATTERN INTO NEXT WEEK. UPPER TROUGHING WITH SLOW MOVING SFC LOW REORGANIZES INTO UPPER LOW OVER HUDSON BAY AND NUNAVUT CANADA BY END OF THE WEEK. EXPECT UPPER RIDGE OVER PACIFIC NORTHWEST TO THE ROCKIES EARLY THIS WEEK TO MOVE ACROSS THE PLAINS TO THE WESTERN GREAT LAKES BY THIS WEEKEND AS TROUGHING DEEPENS AND SETTLES ACROSS WESTERN CANADA AND THE PACIFIC NORTHWEST. CHANCES FOR MUCH RAINFALL IN THIS PATTERN ARE SLIM. STARTING WITH WEDNESDAY NIGHT...HIGH PRESSURE RIDGE SETTLES ACROSS THE AREA SO WINDS WILL BECOME LIGHT. THE LIGHT WINDS AND PWATS DOWN BLO 0.5 INCH SHOULD LEAD TO GOOD RADIATIONAL COOLING. LOWERED MINS INTO THE MIDDLE 30S FOR TYPICAL COLD SPOTS OVER INTERIOR. SOUNDINGS SHOW LOW-LEVEL MOISTENING AS WELL SO THERE MAY BE FOG. ALSO ADDED MENTION OF FROST FOR COLDEST SPOTS. THIS NIGHT APPEARS TO BE TAIL END OF THE FALL LIKE CONDITIONS BEFORE WARMING TREND STARTS UP ON THURSDAY. ONLY NOTABLE CHANCES OF RAIN WOULD BE LATE THURSDAY NIGHT INTO FRIDAY AS WEAK COLD FRONT MAKES BRIEF PUSH ACROSS NORTHWEST ONTARIO AND THE UPPER GREAT LAKES. LARGER SCALE SUPPORT NOT VERY STRONG FOR RAIN OVER UPR MICHIGAN AS UPPER LEVEL SHORTWAVE ENERGY IS GENERALLY DISPLACED OF UPPER LAKES WITH ONE STRONGER SHORTWAVE CROSSING WELL TO THE NORTH OVER NORTHERN MANITOBA AND NORTHERN ONTARIO AND OTHER STRONGER SHORTWAVE SLIDING FM WYOMING/NEBRASKA TO IOWA/NORTHERN ILLINOIS. RESULT IS STRONGEST Q-VECTOR CONVERGENCE/LIFT STAYING OVER NORTHERN ONTARIO AND FM SOUTHERN MINNESOTA TO WISCONSIN AND LOWER MICHIGAN. APPEARS THAT GREATEST MOISTURE INFLOW IN FORM OF H85 THETA-E ADVECTION IS INTERCEPTED BY SOUTHERN SHORTWAVE. NO HELP FM INSTABILITY WITH STRONGER MUCAPE STAYING OVER THE NORTHERN PLAINS THURSDAY NIGHT INTO FRIDAY. BETTER SIGNAL FOR CONVECTION RUNS FM SOUTHERN MINNESOTA TO SOUTHERN WISCONSIN CLOSER TO H85 MOISTURE TRANSPORT. LOWER RANGE CHANCE POPS IS ALL THAT THIS FRONTAL BOUNDARY WARRANTS ATTM FOR THURSDAY NIGHT INTO FRIDAY. WEAKNESS IN THE UPPER LEVEL FLOW...VERY WEAK TROUGHING...LINGERS OVER THE WESTERN GREAT LAKES ON SATURDAY. GFS SOUNDINGS SHOW NARROW LAYER OF LOW-LEVEL MOISTURE BUT THIS IS PROBABLY NOT ENOUGH TO SUPPORT SHOWERS. PROBABLY WILL BE SOME SORT OF ONSHORE COMPONENT TO THE WINDS OVER THE EAST HALF OF CWA CLOSER TO HIGH PRESSURE OVER MUCH OF THE GREAT LAKES. WEST HALF OF CWA SHOULD START TO SEE MORE S/SW WINDS AHEAD OF DEVELOPING TROUGHING IN THE PLAINS. H85 TEMPS COOL A FEW DEGREES COMPARED TO FRIDAY. WARMEST TEMPS ON SATURDAY IN THE LOW-MID 70S SHOULD BE OVER THE WEST WITH LESS INFLUENCE OF GREAT LAKES COOLING AND BETTER CHANCES OF SEEING SOME SUNSHINE. UPPER LEVEL RIDGING TAKES BETTER HOLD ON SUNDAY. SFC WINDS REMAIN LIGHT AS SFC RIDGE IS STILL CLOSE BY TO THE EAST. WITH H85 TEMPS WARMING TO 13-15C...SHOULD SEE READINGS MOST AREAS AT LEAST INTO THE UPPER 70S. LOWER 80S OVER THE WEST WITH LESS LAKE INFLUENCE AND WARMER TEMPS ALOFT. RIDGING ALOFT FIRMLY OVERHEAD ON MONDAY WITH GRADIENT S WIND BTWN HIGH PRESSURE OVER LOWER GREAT LAKES AND NEW ENGLAND AND A LOW PRESSURE TROUGH OVER THE NORTHERN PLAINS. H85 TEMPS VARY WILDLY THOUGH WITH THE ECMWF PUSHING BULK OF WARMTH CLOSER TO THE SFC TROUGH AND OVER NORTHERN ONTARIO /H85 TEMPS UP TO 15C OVER UPR MICHIGAN/ WHILE GFS SHOWS H85 TEMPS PUSHING PAST 22C ACROSS UPR MICHIGAN. BLEND OF GUIDANCE AND SYNOPTIC SETUP ALONE JUSTIFIES CONSENSUS TEMPS TO AT LEAST LOWER 80S. NOT A LOT OF CHANGE FOR FIRST DAY OF SEPTEMBER WITH LINGERING UPPER RIDGE AND APPROACHING SFC FRONT. GFS BRINGS FRONT THROUGH UPPER LAKES QUICKER...BUT EXPECT SLOWER IDEA FM ECMWF GIVEN THE UPPER RIDGE IT WILL BE RUNNING UP AGAINST. DRY WEATHER AND WARMING TEMPS ALOFT AHEAD OF FRONT WITH STRONGER S/SW WINDS WILL GIVE MOST AREAS AWAY FM LK MICHIGAN SHORE A GOOD CHANCE OF SEEING HIGHS INTO MIDDLE OR POSSIBLY UPPER 80S. LOWER TO MIDDLE 80S WITH ONLY SLIGHT CHANCE POPS WILL DO FOR NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 128 PM EDT TUE AUG 25 2015 A NW FLOW OF COOL...MOIST AIR AROUND LOW PRES NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO KIWD/KCMX/KSAW THRU THE AFTN. WINDS THIS AFTN WILL STILL BE GUSTY TO 20KT AT KSAW AND TO 25KT AT KCMX. OCNL -RA AND -DZ ARE POSSIBLE AT KCMX AND ESPECIALLY KSAW THIS AFTN...BUT SHOULDN`T REDUCE VIS BLO VFR. APPROACHING HIGH PRES AND INFLUX OF DRIER AIR MAY ALLOW CIGS TO RISE TO VFR AT KIWD FOR A TIME THIS EVENING BEFORE LOWERING SUBSIDENCE INVERSION BRINGS CIGS BACK TO MVFR OVERNIGHT. AS HIGH PRES CONTINUES TO BUILD INTO THE AREA WED...MVFR CIGS WILL SCATTER OUT AT KIWD/KCMX IN THE MORNING. CLEARING WILL OCCUR LATER IN THE AFTN AT KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 PM EDT TUE AUG 25 2015 WITH LOW PRES NEAR JAMES BAY CONTINUING TO MOVE AWAY FROM THE AREA AND HIGH PRES OVER THE PLAINS APPROACHING...WINDS WILL CONTINUE TO DIMINISH ACROSS LAKE SUPERIOR FROM W TO E TONIGHT AND WED. WINDS TONIGHT WILL GENERALLY RANGE FROM 10-20KT W TO 15-30KT E. WINDS ON WED WILL DIMINISH TO UNDER 15KT W AND UNDER 20KT E BY THE END OF THE AFTN. AS THE HIGH MOVES OVER THE UPPER LAKES WED NIGHT...WINDS WILL BE UNDER 15KT ACROSS LAKE SUPERIOR. WINDS WILL BE MOSTLY UNDER 20KT THU THRU SUN. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...BEACH HAZARDS STATEMENT INTO THIS EVENING FOR MIZ005-006. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
305 PM EDT TUE AUG 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT TUE AUG 25 2015 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UNSEASONABLY DEEP CLOSED LO IN ONTARIO JUST NE OF LK SUP DRIFTING SLOWLY TO THE E... WITH SHARP CYC FLOW ARND THIS FEATURE DOMINATING THE GREAT LKS. LOCAL RAOBS INDICATE THE SFC-H7 LYR IS QUITE MOIST WITH H925...H85 AND H7 DEWPT DEPRESSIONS AT INL AND E NO MORE THAN A FEW DEGREES C. THERE ARE ALSO TWO SHRTWVS OF NOTE ROTATING ARND THE LARGER SCALE FEATURE. THE FIRST OF THESE IS NOW HEADING INTO NRN LK MI AT THE BEGINNING OF THE SHIFT AND TAKING THE MORE WIDESPREAD SHOWERS THAT HAD IMPACTED THE ERN CWA LAST EVNG TO THE SE WITH IT. IN THE WAKE OF THIS DISTURBANCE...SFC OBS AND THE MQT 88D INDICATE RELATIVELY FEW SHOWERS...MAINLY JUST SOME DRIZZLE...LINGER OVER UPR MI EARLY THIS MRNG DESPITE THE MOIST LLVLS AND SHARP CYC NW FLOW. THE CULPRITS APPEAR TO BE LARGER SCALE QVECTOR DVGC TO THE W OF THE CLOSED LO AND BEHIND THE DEPARTING SHRTWV AND RATHER SHARP H875-85 INVRN SHOWN ON THE 00Z INL/YPL RAOBS ASSOCIATED WITH THESE NEGATIVE DYNAMICS/HGT RISES THAT IS LIMITING THE LK EFFECT COMPONENT TO THE NE OF H85 THERMAL TROF CENTERED ON AN AXIS FM INL TO GRB. 00Z H85 TEMPS WERE 3C AT INL AND GRB...BUT 10C AT YPL. WV IMAGERY/RAP ANALYSIS INDICATE ANOTHER SHRTWV ROTATING SWD TO THE W OF THE CLOSED LO IS DROPPING THRU NW ONTARIO. THE LATEST THUNDER BAY RADAR SHOWS AN AREA OF MORE NMRS SHOWERS OVER LK NIPIGON MOVING INTO NRN LK SUP. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS ASSOCIATED SHRTWV ROTATING SWD ARND SLOWLY DEPARTING CLOSED LO. TODAY...WHILE ONTARIO SHRTWV MOVING TO THE S IS ON TRACK TO MOVE INTO NRN LK SUP THIS MRNG...MODELS INDICATE DEEP LYR QVECTOR DVGC AND HGT RISES...FCST TO BE ABOUT 50M BTWN 12Z-24Z TODAY...LEFT IN THE WAKE OF THE CLOSED LO WL DOMINATE. SO ALTHOUGH FCST PROFILES INDICATE SOME DEEPENING MSTR THRU THIS MRNG...THEY ALSO SHOW A NEAR ABSENCE OF ANY UVV...IN FACT MAINLY LARGE SCALE SUBSIDENCE THAT WL MAINTAIN THE INVRN NEAR H85 AND LIMIT POPS. THE ERN CWA HAS A BETTER CHC TO SEE THE HIER POPS...AS THIS AREA WL BE CLOSER TO THE DEPARTING DISTURBANCE/WEAKER SUBSIDENCE WITH AT LEAST SOME UVV/ SHARPER CYC FLOW AND DOWNSTREAM OF LK SUP IN PERSISTENT NW FLOW THAT WL ACCENTUATE LLVL CNVGC. GIVEN THESE NEGATIVES...TENDED TO LOWER GOING POPS. PLENTY OF LO CLDS WL LIMIT THE DIURNAL TEMP RECOVERY AGAIN DESPITE SLOWLY MODERATING H85 TEMPS THAT WL ALLOW FOR A WARMER DAY THAN YDAY. THE STEADY/GUSTY NW WINDS WL CONTINUE TO WHIP UP HI WAVES ON LAKE SUP...RESULTING IN A HI SWIM RISK FOR MARQUETTE AND ALGER COUNTIES. TNGT...WITH CONTINUED SLOW HGT RISES/DEEP LYR QVECTOR DVGC/WEAKENING LLVL CYC FLOW TO THE W OF WEAKENING CLOSED LO THAT IS FCST TO LIFT NE TOWARD THE S END OF JAMES BAY BY 12Z WED...EXPECT DIMINISHING POPS. THIS TREND WL BE MOST PRONOUNCED OVER THE W...WHERE THE LLVL FLOW WL BECOME MORE ACYC CLOSER TO APRCHG SFC HI PRES MOVING INTO MN. LINGERING LO CLDS WL LIMIT THE DIURNAL TEMP FALL. EXPECT THE COOLEST OVERNGT LOWS TOWARD THE MID 40S OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLRG LATE WITH THE APRCH OF THE SFC HI PRES. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 301 PM EDT TUE AUG 25 2015 GOOD AGREEMENT IN OVERALL LOOK OF LARGE SCALE PATTERN INTO NEXT WEEK. UPPER TROUGHING WITH SLOW MOVING SFC LOW REORGANIZES INTO UPPER LOW OVER HUDSON BAY AND NUNAVUT CANADA BY END OF THE WEEK. EXPECT UPPER RIDGE OVER PACIFIC NORTHWEST TO THE ROCKIES EARLY THIS WEEK TO MOVE ACROSS THE PLAINS TO THE WESTERN GREAT LAKES BY THIS WEEKEND AS TROUGHING DEEPENS AND SETTLES ACROSS WESTERN CANADA AND THE PACIFIC NORTHWEST. CHANCES FOR MUCH RAINFALL IN THIS PATTERN ARE SLIM. STARTING WITH WEDNESDAY NIGHT...HIGH PRESSURE RIDGE SETTLES ACROSS THE AREA SO WINDS WILL BECOME LIGHT. THE LIGHT WINDS AND PWATS DOWN BLO 0.5 INCH SHOULD LEAD TO GOOD RADIATIONAL COOLING. LOWERED MINS INTO THE MIDDLE 30S FOR TYPICAL COLD SPOTS OVER INTERIOR. SOUNDINGS SHOW LOW-LEVEL MOISTENING AS WELL SO THERE MAY BE FOG. ALSO ADDED MENTION OF FROST FOR COLDEST SPOTS. THIS NIGHT APPEARS TO BE TAIL END OF THE FALL LIKE CONDITIONS BEFORE WARMING TREND STARTS UP ON THURSDAY. ONLY NOTABLE CHANCES OF RAIN WOULD BE LATE THURSDAY NIGHT INTO FRIDAY AS WEAK COLD FRONT MAKES BRIEF PUSH ACROSS NORTHWEST ONTARIO AND THE UPPER GREAT LAKES. LARGER SCALE SUPPORT NOT VERY STRONG FOR RAIN OVER UPR MICHIGAN AS UPPER LEVEL SHORTWAVE ENERGY IS GENERALLY DISPLACED OF UPPER LAKES WITH ONE STRONGER SHORTWAVE CROSSING WELL TO THE NORTH OVER NORTHERN MANITOBA AND NORTHERN ONTARIO AND OTHER STRONGER SHORTWAVE SLIDING FM WYOMING/NEBRASKA TO IOWA/NORTHERN ILLINOIS. RESULT IS STRONGEST Q-VECTOR CONVERGENCE/LIFT STAYING OVER NORTHERN ONTARIO AND FM SOUTHERN MINNESOTA TO WISCONSIN AND LOWER MICHIGAN. APPEARS THAT GREATEST MOISTURE INFLOW IN FORM OF H85 THETA-E ADVECTION IS INTERCEPTED BY SOUTHERN SHORTWAVE. NO HELP FM INSTABILITY WITH STRONGER MUCAPE STAYING OVER THE NORTHERN PLAINS THURSDAY NIGHT INTO FRIDAY. BETTER SIGNAL FOR CONVECTION RUNS FM SOUTHERN MINNESOTA TO SOUTHERN WISCONSIN CLOSER TO H85 MOISTURE TRANSPORT. LOWER RANGE CHANCE POPS IS ALL THAT THIS FRONTAL BOUNDARY WARRANTS ATTM FOR THURSDAY NIGHT INTO FRIDAY. WEAKNESS IN THE UPPER LEVEL FLOW...VERY WEAK TROUGHING...LINGERS OVER THE WESTERN GREAT LAKES ON SATURDAY. GFS SOUNDINGS SHOW NARROW LAYER OF LOW-LEVEL MOISTURE BUT THIS IS PROBABLY NOT ENOUGH TO SUPPORT SHOWERS. PROBABLY WILL BE SOME SORT OF ONSHORE COMPONENT TO THE WINDS OVER THE EAST HALF OF CWA CLOSER TO HIGH PRESSURE OVER MUCH OF THE GREAT LAKES. WEST HALF OF CWA SHOULD START TO SEE MORE S/SW WINDS AHEAD OF DEVELOPING TROUGHING IN THE PLAINS. H85 TEMPS COOL A FEW DEGREES COMPARED TO FRIDAY. WARMEST TEMPS ON SATURDAY IN THE LOW-MID 70S SHOULD BE OVER THE WEST WITH LESS INFLUENCE OF GREAT LAKES COOLING AND BETTER CHANCES OF SEEING SOME SUNSHINE. UPPER LEVEL RIDGING TAKES BETTER HOLD ON SUNDAY. SFC WINDS REMAIN LIGHT AS SFC RIDGE IS STILL CLOSE BY TO THE EAST. WITH H85 TEMPS WARMING TO 13-15C...SHOULD SEE READINGS MOST AREAS AT LEAST INTO THE UPPER 70S. LOWER 80S OVER THE WEST WITH LESS LAKE INFLUENCE AND WARMER TEMPS ALOFT. RIDGING ALOFT FIRMLY OVERHEAD ON MONDAY WITH GRADIENT S WIND BTWN HIGH PRESSURE OVER LOWER GREAT LAKES AND NEW ENGLAND AND A LOW PRESSURE TROUGH OVER THE NORTHERN PLAINS. H85 TEMPS VARY WILDLY THOUGH WITH THE ECMWF PUSHING BULK OF WARMTH CLOSER TO THE SFC TROUGH AND OVER NORTHERN ONTARIO /H85 TEMPS UP TO 15C OVER UPR MICHIGAN/ WHILE GFS SHOWS H85 TEMPS PUSHING PAST 22C ACROSS UPR MICHIGAN. BLEND OF GUIDANCE AND SYNOPTIC SETUP ALONE JUSTIFIES CONSENSUS TEMPS TO AT LEAST LOWER 80S. NOT A LOT OF CHANGE FOR FIRST DAY OF SEPTEMBER WITH LINGERING UPPER RIDGE AND APPROACHING SFC FRONT. GFS BRINGS FRONT THROUGH UPPER LAKES QUICKER...BUT EXPECT SLOWER IDEA FM ECMWF GIVEN THE UPPER RIDGE IT WILL BE RUNNING UP AGAINST. DRY WEATHER AND WARMING TEMPS ALOFT AHEAD OF FRONT WITH STRONGER S/SW WINDS WILL GIVE MOST AREAS AWAY FM LK MICHIGAN SHORE A GOOD CHANCE OF SEEING HIGHS INTO MIDDLE OR POSSIBLY UPPER 80S. LOWER TO MIDDLE 80S WITH ONLY SLIGHT CHANCE POPS WILL DO FOR NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 128 PM EDT TUE AUG 25 2015 A NW FLOW OF COOL...MOIST AIR AROUND LOW PRES NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO KIWD/KCMX/KSAW THRU THE AFTN. WINDS THIS AFTN WILL STILL BE GUSTY TO 20KT AT KSAW AND TO 25KT AT KCMX. OCNL -RA AND -DZ ARE POSSIBLE AT KCMX AND ESPECIALLY KSAW THIS AFTN...BUT SHOULDN`T REDUCE VIS BLO VFR. APPROACHING HIGH PRES AND INFLUX OF DRIER AIR MAY ALLOW CIGS TO RISE TO VFR AT KIWD FOR A TIME THIS EVENING BEFORE LOWERING SUBSIDENCE INVERSION BRINGS CIGS BACK TO MVFR OVERNIGHT. AS HIGH PRES CONTINUES TO BUILD INTO THE AREA WED...MVFR CIGS WILL SCATTER OUT AT KIWD/KCMX IN THE MORNING. CLEARING WILL OCCUR LATER IN THE AFTN AT KSAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT TUE AUG 25 2015 SHARP PRES GRADIENT ON THE WESTERN FLANK OF DEEP LO PRES MOVING THRU ONTARIO TO THE E OF LAKE SUPERIOR WILL MAINTAIN NW WINDS UP TO 30 KTS TODAY. THE PASSAGE OF A DISTURBANCE THIS MORNING MAY CAUSE SOME GALE FORCE GUSTS IN A CORRIDOR OVER THE CENTRAL LAKE. BUT AS THE LO TO THE E WEAKENS AND MOVES TOWARD JAMES BAY TONIGHT...APPROACHING HI PRES/WEAKENING PRES GRADIENT WILL CAUSE WINDS TO DIMINISH W-E. AS THE HI MOVES OVER THE UPPER LAKES LATE WED/WED NIGHT...EXPECT WINDS TO FALL UNDER 20 KTS. A RELATIVELY FLAT PRES GRADIENT WILL DOMINATE LATE WEEK INTO THE WEEKEND...SO WINDS FOR THE MOST PART SHOULD BE UNDER 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...BEACH HAZARDS STATEMENT INTO THIS EVENING FOR MIZ005-006. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 PM EDT TUE AUG 25 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 409 AM EDT TUE AUG 25 2015 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UNSEASONABLY DEEP CLOSED LO IN ONTARIO JUST NE OF LK SUP DRIFTING SLOWLY TO THE E... WITH SHARP CYC FLOW ARND THIS FEATURE DOMINATING THE GREAT LKS. LOCAL RAOBS INDICATE THE SFC-H7 LYR IS QUITE MOIST WITH H925...H85 AND H7 DEWPT DEPRESSIONS AT INL AND E NO MORE THAN A FEW DEGREES C. THERE ARE ALSO TWO SHRTWVS OF NOTE ROTATING ARND THE LARGER SCALE FEATURE. THE FIRST OF THESE IS NOW HEADING INTO NRN LK MI AT THE BEGINNING OF THE SHIFT AND TAKING THE MORE WIDESPREAD SHOWERS THAT HAD IMPACTED THE ERN CWA LAST EVNG TO THE SE WITH IT. IN THE WAKE OF THIS DISTURBANCE...SFC OBS AND THE MQT 88D INDICATE RELATIVELY FEW SHOWERS...MAINLY JUST SOME DRIZZLE...LINGER OVER UPR MI EARLY THIS MRNG DESPITE THE MOIST LLVLS AND SHARP CYC NW FLOW. THE CULPRITS APPEAR TO BE LARGER SCALE QVECTOR DVGC TO THE W OF THE CLOSED LO AND BEHIND THE DEPARTING SHRTWV AND RATHER SHARP H875-85 INVRN SHOWN ON THE 00Z INL/YPL RAOBS ASSOCIATED WITH THESE NEGATIVE DYNAMICS/HGT RISES THAT IS LIMITING THE LK EFFECT COMPONENT TO THE NE OF H85 THERMAL TROF CENTERED ON AN AXIS FM INL TO GRB. 00Z H85 TEMPS WERE 3C AT INL AND GRB...BUT 10C AT YPL. WV IMAGERY/RAP ANALYSIS INDICATE ANOTHER SHRTWV ROTATING SWD TO THE W OF THE CLOSED LO IS DROPPING THRU NW ONTARIO. THE LATEST THUNDER BAY RADAR SHOWS AN AREA OF MORE NMRS SHOWERS OVER LK NIPIGON MOVING INTO NRN LK SUP. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS ASSOCIATED SHRTWV ROTATING SWD ARND SLOWLY DEPARTING CLOSED LO. TODAY...WHILE ONTARIO SHRTWV MOVING TO THE S IS ON TRACK TO MOVE INTO NRN LK SUP THIS MRNG...MODELS INDICATE DEEP LYR QVECTOR DVGC AND HGT RISES...FCST TO BE ABOUT 50M BTWN 12Z-24Z TODAY...LEFT IN THE WAKE OF THE CLOSED LO WL DOMINATE. SO ALTHOUGH FCST PROFILES INDICATE SOME DEEPENING MSTR THRU THIS MRNG...THEY ALSO SHOW A NEAR ABSENCE OF ANY UVV...IN FACT MAINLY LARGE SCALE SUBSIDENCE THAT WL MAINTAIN THE INVRN NEAR H85 AND LIMIT POPS. THE ERN CWA HAS A BETTER CHC TO SEE THE HIER POPS...AS THIS AREA WL BE CLOSER TO THE DEPARTING DISTURBANCE/WEAKER SUBSIDENCE WITH AT LEAST SOME UVV/ SHARPER CYC FLOW AND DOWNSTREAM OF LK SUP IN PERSISTENT NW FLOW THAT WL ACCENTUATE LLVL CNVGC. GIVEN THESE NEGATIVES...TENDED TO LOWER GOING POPS. PLENTY OF LO CLDS WL LIMIT THE DIURNAL TEMP RECOVERY AGAIN DESPITE SLOWLY MODERATING H85 TEMPS THAT WL ALLOW FOR A WARMER DAY THAN YDAY. THE STEADY/GUSTY NW WINDS WL CONTINUE TO WHIP UP HI WAVES ON LAKE SUP...RESULTING IN A HI SWIM RISK FOR MARQUETTE AND ALGER COUNTIES. TNGT...WITH CONTINUED SLOW HGT RISES/DEEP LYR QVECTOR DVGC/WEAKENING LLVL CYC FLOW TO THE W OF WEAKENING CLOSED LO THAT IS FCST TO LIFT NE TOWARD THE S END OF JAMES BAY BY 12Z WED...EXPECT DIMINISHING POPS. THIS TREND WL BE MOST PRONOUNCED OVER THE W...WHERE THE LLVL FLOW WL BECOME MORE ACYC CLOSER TO APRCHG SFC HI PRES MOVING INTO MN. LINGERING LO CLDS WL LIMIT THE DIURNAL TEMP FALL. EXPECT THE COOLEST OVERNGT LOWS TOWARD THE MID 40S OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLRG LATE WITH THE APRCH OF THE SFC HI PRES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 251 AM EDT TUE AUG 25 2015 COULD SEE SOME ISOLATES SHOWERS OVER THE ERN CWA WED MORNING AS NW WINDS AND 850MB TEMPS OF 5-6C ALLOW FOR LAKE ENHANCED RAIN...BUT OVERALL FORCING WILL BE WEAK. HIGH PRESSURE MOVING IN WILL BRING AN END TO RAIN POTENTIAL BY WED AFTERNOON. HIGHS WED IN THE 60S WILL COMBINE WITH GOOD RADIATIONAL COOLING...DRY CONDITIONS AND LIGHT WINDS WED NIGHT TO BRING LOWS IN THE 40S INLAND...WITH A FEW SPOTS IN THE UPPER 30S. SW FLOW AS THE HIGH MOVES OUT WILL BRING 850MB TEMPS UP TO 14C BY THE END OF THE DAY THU...RESULTING IN NEAR NORMAL HIGHS IN THE LOW TO MID 70S. DRY WEATHER PERSISTS THROUGH THU. MODELS CONTINUE TO INDICATE A COLD FRONT MOVING S FROM CANADA AND INTO THE CWA THU NIGHT AND FRI WHILE A SHORTWAVE RIDES DOWN NW FLOW AND PASSES OVER OR NEAR THE CWA. MODELS HAVE BEEN VARIABLE WITH SOLUTIONS FOR THIS TIME PERIOD...BUT THE ECMWF HAS BEEN THE MOST STEADY. OVERALL...CHANCES FOR SHOWERS AND THUNDERSTORMS SEEM REASONABLE. PRECIP IS QUESTIONABLE FOR SAT...BUT COULD SEE SOME SHOWERS IF SHORTWAVE ENERGY MOVES THROUGH. LEFT SLIGHT CHANCE POPS FOR NOW. TEMPS LOOK SIMILAR TO FRI. TEMPS LOOK TO BE ABOVE NORMAL SUN AND MON WITH DRY WEATHER AS RIDGING BUILDS OVER THE AREA. HIGHS SHOULD RANGE FROM THE MID/UPPER 70S TO LOW 80S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 128 PM EDT TUE AUG 25 2015 A NW FLOW OF COOL...MOIST AIR AROUND LOW PRES NE OF LAKE SUPERIOR WILL BRING PREVAILING MVFR CONDITIONS TO KIWD/KCMX/KSAW THRU THE AFTN. WINDS THIS AFTN WILL STILL BE GUSTY TO 20KT AT KSAW AND TO 25KT AT KCMX. OCNL -RA AND -DZ ARE POSSIBLE AT KCMX AND ESPECIALLY KSAW THIS AFTN...BUT SHOULDN`T REDUCE VIS BLO VFR. APPROACHING HIGH PRES AND INFLUX OF DRIER AIR MAY ALLOW CIGS TO RISE TO VFR AT KIWD FOR A TIME THIS EVENING BEFORE LOWERING SUBSIDENCE INVERSION BRINGS CIGS BACK TO MVFR OVERNIGHT. AS HIGH PRES CONTINUES TO BUILD INTO THE AREA WED...MVFR CIGS WILL SCATTER OUT AT KIWD/KCMX IN THE MORNING. CLEARING WILL OCCUR LATER IN THE AFTN AT KSAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT TUE AUG 25 2015 SHARP PRES GRADIENT ON THE WESTERN FLANK OF DEEP LO PRES MOVING THRU ONTARIO TO THE E OF LAKE SUPERIOR WILL MAINTAIN NW WINDS UP TO 30 KTS TODAY. THE PASSAGE OF A DISTURBANCE THIS MORNING MAY CAUSE SOME GALE FORCE GUSTS IN A CORRIDOR OVER THE CENTRAL LAKE. BUT AS THE LO TO THE E WEAKENS AND MOVES TOWARD JAMES BAY TONIGHT...APPROACHING HI PRES/WEAKENING PRES GRADIENT WILL CAUSE WINDS TO DIMINISH W-E. AS THE HI MOVES OVER THE UPPER LAKES LATE WED/WED NIGHT...EXPECT WINDS TO FALL UNDER 20 KTS. A RELATIVELY FLAT PRES GRADIENT WILL DOMINATE LATE WEEK INTO THE WEEKEND...SO WINDS FOR THE MOST PART SHOULD BE UNDER 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...BEACH HAZARDS STATEMENT INTO THIS EVENING FOR MIZ005-006. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
232 PM PDT TUE AUG 25 2015 .SYNOPSIS...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TONIGHT INTO WEDNESDAY MORNING AS A SERIES OF DISTURBANCES MOVE OVER THE REGION. SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT PRIMARILY THE HIGHER TERRAIN WEDNESDAY AND THURSDAY BEFORE GRADUAL DRYING COMMENCES FRIDAY. DRIER CONDITIONS ARE EXPECTED THROUGH THE WEEKEND. && .SHORT TERM...THROUGH THURSDAY NIGHT. WELL DEFINED VORT MAX WHICH WAS INITIALIZED NEAR PHOENIX THIS MORNING HAS MOVED NORTH TO NEAR PRESCOTT AT MID-AFTERNOON. A LINE OF HEAVIER RAIN SHOWERS AND EMBEDDED THUNDERSTORMS EXTENDS FROM NEAR WIKIEUP NORTH TO PEACH SPRINGS...THEN NORTHEAST TOWARD MT TRUMBULL. LOCALLY HEAVY RAIN HAS OCCURRED WITH THIS LINE IN THE MOUNTAINS NORTHEAST OF WIKIEUP WITH ONE MOHAVE COUNTY FLOOD CONTROL DISTRICT STATION REPORTING ABOUT TWO-THIRDS OF AN INCH. HRRR HAS THE SOUTHERN PORTION OF THE LINE WEAKENING AS IT CONTINUE EAST ACROSS SOUTHERN MOHAVE COUNTY THE REST OF THIS AFTERNOON. THE VORT MAX IS PROGGED TO CONTINUE NORTH INTO SOUTHWEST UTAH BY EARLY WEDNESDAY MORNING. EXPECT A PORTION OF THE NORTHERN LINE TO SEE ADDITIONAL DEVELOPMENT AS IT CONTINUES NORTHWEST THROUGH NORTHERN MOHAVE COUNTY POTENTIALLY AFFECTING PARTS OF NORTHEAST CLARK AND LINCOLN COUNTY THIS EVENING AND OVERNIGHT. ELSEWHERE, PRECIPITATION HAS BEEN LIGHT AND DO NOT FORESEE THIS CHANGING MUCH SO DECIDED TO LOWER POPS TONIGHT FOR SAN BERNARDINO COUNTY AND THE REST OF CLARK COUNTY. MONSOON MOISTURE THAT MOVED INTO THE REGION TUESDAY WILL STILL BE AVAILABLE WEDNESDAY. FORECAST SOUNDINGS STILL SHOWING MORE INSTABILITY TOMORROW. CONVECTION SHOULD BE STRONGLY TERRAIN DRIVEN WITH ISOLATED POCKETS OF HEAVY RAIN POSSIBLE. FLOW ALOFT WILL TURN MORE SOUTHWESTERLY THURSDAY AND FRIDAY ALLOWING FOR GRADUAL DRYING TREND. DID INTRODUCE A SLIGHT CHANCE OF STORMS INTO THE HIGHER TERRAIN OF MOHAVE COUNTY FRIDAY. CLOUDINESS HAS KEPT TEMPERATURES BELOW NORMAL TODAY. MORE SUNSHINE AND DRYING TREND FOR THE REST OF THE WEEK WE WILL SEE TEMPERATURES RETURN TO ABOUT 5 DEGREES ABOVE NORMAL FRIDAY. OUTSIDE OF GUSTY WINDS ASSOCIATED WITH CONVECTION NO SIGNIFICANT WINDS EXPECTED. .LONG TERM...SATURDAY THROUGH TUESDAY. DRIER SOUTHWESTERLY FLOW IS EXPECTED TO SWEEP ACROSS THE REGION FRIDAY...FINALLY SCOURING OUT MOISTURE FROM WEST TO EAST AND EFFECTIVELY ENDING CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY. ALONG WITH BENIGN WEATHER CONDITIONS...THIS WILL YIELD A QUICK WARMUP IN TEMPERATURES WITH AFTERNOON HIGHS RUNNING SEVERAL DEGREES ABOVE AVERAGE ACROSS THE AREA FRIDAY. A SLIGHT CHANGE IN OUR WEATHER COULD BE IN STORE FOR THE WEEKEND AS THE LATEST OPERATIONAL MODELS SHOW GOOD AGREEMENT IN A SHORTWAVE ASSOCIATED WITH AN UPPER LEVEL LOW OFF OF THE PACIFIC NORTHWEST COAST TO EJECT ACROSS THE PACIFIC NORTHWEST AND NORTHERN GREAT BASIN. THIS WILL YIELD A COOLING TREND IN TEMPERATURES AND BREEZY CONDITIONS ACROSS THE SOUTHERN GREAT BASIN AND MOJAVE DESERT THROUGH THE END OF THE WEEKEND. THOUGH GUIDANCE IS MORE IN LINE WITH THE OVERALL EVOLUTION OF THE UPPER LOW TONIGHT...LARGE DISCREPANCIES IN THE OVERALL TIMING AND STRENGTH OF THIS FEATURE CONTINUE TO EXIST TONIGHT. THE 00Z ECMWF OUTPUT IS MUCH MORE PROGRESSIVE AND LESS AMPLIFIED THAN THE 00Z GFS...WHICH IS 24-36 HOURS SLOWER IN TRAVERSING THE UPPER LOW ACROSS THE PACIFIC NORTHWEST/NORTHERN GREAT BASIN. THESE DIFFERENCES YIELD A 3-4 DEGREE TEMPERATURE SPREAD IN NUMERICAL GUIDANCE AFTER SUNDAY...THEREFORE A BLEND OF BOTH SOLUTIONS WAS USED FOR MAX AND MIN FORECASTS FOR MONDAY AND TUESDAY. DESPITE THESE DIFFERENCES...THE BOTTOM LINE IS THAT WE CAN EXPECT DRY...BREEZY...AND COOLER CONDITIONS THROUGH THE END OF THE PERIOD. && .AVIATION...FOR MCCARRAN...DECREASING CHANCES FOR RAIN SHOWERS THROUGH THE REST OF THE AFTERNOON WITH WINDS GENERALLY FROM A SOUTH DIRECTION. HOWEVER THEY MAY SHIFT BACK AND FORTH BETWEEN SOUTHEAST AND SOUTHWEST AT TIMES. SOME OF THE HI-RES MODELS SHOW THE POTENTIAL OF STRONGER SOUTHEAST WINDS POSSIBLY AFFECTING THE LAS VEGAS VALLEY THIS EVENING. CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAF AT THIS TIME. CHANCES FOR SHOWERS WILL INCREASE AGAIN LATE THIS EVENING AND PERSIST THROUGH WEDNESDAY. CIGS WILL DROP FROM 15-20K FEET THIS AFTERNOON TO AROUND 8-10K FEET OVERNIGHT. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...WIDESPREAD CLOUDS WITH CIGS IN THE 10-20K FEET RANGE WILL BE COMMON TODAY ALONG AND EAST OF A KDAG-KTPH LINE. SCATTERED LIGHT SHOWERS AND SPRINKLES WILL BE POSSIBLE EAST OF THIS LINE AS WELL...WITH ISOLATED THUNDERSTORMS POSSIBLE PRIMARILY ACROSS MOHAVE COUNTY. SURFACE WINDS WILL BE GUSTY AND VARIABLE NEAR STORMS BUT OTHERWISE GENERALLY LIGHT AND SOUTHERLY. MODELS INDICATED THE POSSIBILITY IF ENHANCED EAST TO SOUTHEAST WINDS THIS EVENING AND OVERNIGHT MOVING ACROSS THE COLORADO RIVER VALLEY...HOWEVER CONFIDENCE IN STRENGTH AND TIMING IS LOW AT THIS TIME. CIGS ARE EXPECTED TO DECREASE TO 6-10K FEET OVERNIGHT WITH CHANCES FOR STORMS CONTINUING OVERNIGHT AND THROUGH WEDNESDAY. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ SHORT TERM...PIERCE AVIATION...WOLCOTT LONG TERM...PULLIN 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
255 PM EDT TUE AUG 25 2015 .SYNOPSIS... A WEAK COLD FRONT APPROACHES FROM THE WEST TODAY THEN WILL STALL OVER THE AREA TONIGHT AND WEDNESDAY. THE FRONT WILL THEN SLOWLY MOVE OFF THE COAST WEDNESDAY NIGHT AND THURSDAY BUT LINGER JUST OFFSHORE INTO FRIDAY. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THIS WEEKEND. && .NEAR TERM /REST OF TODAY/... AS OF 100 PM TUESDAY...UPDATED TO ADJUST POPS BASED ON LATEST RADAR TRENDS AND PRIMARY HRRR MODEL. WEAK FRONTAL BNDRY HAS PUSHED INTO COASTAL PLAIN WITH SUFFICIENT CONVERGENCE ALONG WITH WEAK SHRT WV ENERGY TO PRODUCE SCT-BKN LINES OF SHOWERS/ISOLD TSTMS GENERALLY ALONG HWY 17. LATEST HRRR MODEL HAS GOOD HANDLE ON THIS ACTIVITY...AND INDICATES ACTIVITY GRADUALLY DEVELOPING NE AND E THROUGH MID AFTN WITH SOME ADDITIONAL DEVELOPMENT NEAR COAST AND ACROSS COASTAL PLAINS TOWARD EVENING. PW AROUND 2 INCHES AND SLOW- MOVING CELLS SUPPORT LOCALLY HEAVY RAIN...AND TRAINING AND POSSIBLY BACK-BUILDING MAY RESULT IN LOCALIZED FLOODING. MINOR ADJUSTMENTS TO TEMPS. /PREVIOUS DISCUSSION/ AS OF 630 AM TUESDAY...A SLOW MOVING UPPER LOW CENTERED OVER SOUTHERN CANADA WILL CONTINUE TO PRODUCE AN UPPER TROUGH OVER THE EASTERN US THROUGH MID WEEK. AT THE SURFACE AN EASTWARD MOVING WEAK COLD FRONT WAS LOCATED OVER CENTRAL NC. THIS FRONT WILL MOVE INTO EASTERN NC THIS AFTERNOON THEN STALL ACROSS THE AREA TONIGHT. THE AIRMASS AHEAD OF THE FRONT WILL CONTINUE TO MOISTEN WITH 850 MB DEWPOINTS IN THE MID TEENS AND PW VALUES AROUND 2" AND MEAN 1000-5000 MB RH AOA 70%. THIS HIGH MOISTURE CONTENT IN CONJUNCTION WITH FRONTAL LIFT AND WEAK MID LEVEL IMPULSES MOVING THROUGH THE UPPER LEVEL TROUGH WILL PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS ESPECIALLY THIS AFTERNOON ALTHOUGH THERE IS SOME SUPPORT FOR SOME ACTIVITY TO DEVELOP THIS MORNING AND RADAR INDICATED A LINE OF SHOWERS DEVELOPING NEAR SUNSET BEACH AND SOME LIGHTER RETURNS OVER THE COASTAL PLAIN. THE HIGH PW VALUES SHOULD SUPPORT THE FORMATION OF CONSIDERABLE CLOUDINESS WITH HEATING AND THIS WILL LIMIT HIGH TEMPERATURES SOME. THE MAIN CONVECTIVE THREAT TODAY WILL BE LOCALLY HEAVY RAINS DUE TO SLOW CELL MOVEMENT AND POSSIBLE TRAINING. HIGHS WILL BE IN THE MID TO UPPER 80S. && .SHORT TERM /TONIGHT/... AS OF 330 AM TUESDAY...THE BEST CHANCE FOR RAIN SHOULD BE IN THE EVENING BUT WITH THE STALLED FRONT OVER THE AREA WILL NEED TO KEEP CHANCE POPS FOR THE ENTIRE NIGHT. LOWS INLAND ARE EXPECTED TO BE IN THE UPPER 60S TO LOWER 70S AND MID 70S BEACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... AS OF 255 PM TUESDAY...AN UPPER LOW NORTH OF THE GREAT LAKES WILL PUSH EAST ACROSS QUEBEC WEDNESDAY INTO THURSDAY, ALLOWING THE UPPER TROUGH AXIS TO SHIFT EAST INTO NC BY THURSDAY THEN DE- AMPLIFYING AS IT CROSSES THE CAROLINAS INTO THURSDAY NIGHT. WEAK ZONAL FLOW DEVELOPS FRIDAY WITH THE UPPER RIDGE OVER BERMUDA BUILDING WEST TOWARDS THE SOUTHEASTERN STATES. AT THE SURFACE, A WEAK FRONT ACROSS EASTERN NC WILL MOVE OFF THE COAST AND STALL WEDNESDAY NIGHT THROUGH FRIDAY. LITTLE CHANGE IN FORECAST REASONING BASED ON 12Z GUIDANCE THROUGH THE PERIOD. UPPER LEVEL JET STRENGTHENS ACROSS THE MID ATLANTIC AND NEW ENGLAND COAST WEDNESDAY NIGHT THROUGH THURSDAY WITH COASTAL AND OFFSHORE AREAS OF EASTERN NC POSITIONED IN THE FAVORABLE RIGHT ENTRANCE REGION OF THE JET. THE FRONTAL BOUNDARY AND DEEPEST MOISTURE REMAINS STALLED OFFSHORE THROUGH THURSDAY NIGHT AND WILL MAINTAIN SLIGHT CHANCE POPS INLAND TO HIGH CHANCE POPS FOR COASTAL SECTIONS. THE UPPER TROUGH LIFTS NORTH OF THE REGION THURSDAY NIGHT WITH THE UPPER RIDGE ACROSS THE WESTERN ATLANTIC BUILDING WEST INTO THE SOUTHEAST FRIDAY THROUGH EARLY NEXT WEEK. MEANWHILE, SURFACE HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO SATURDAY, THEN TRANSITIONS OFFSHORE WITH THE PIEDMONT TROUGH DEVELOPING SUNDAY THROUGH TUESDAY. EXPECT A MORE TYPICAL DIURNALLY DRIVEN, MAINLY ISOLATED SHOWER/THUNDERSTORM PATTERN THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH 18Z WEDNESDAY/... AS OF 130 PM TUESDAY...VFR CONDITIONS EXPECTED OUTSIDE SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. MOIST SOILS, A SATURATED LOW LEVEL AIRMASS AND THE POTENTIAL FOR RADIATIONAL COOLING ARE ALL POINTING TO A HIGHER POTENTIAL FOR FOG AND IFR CONDITIONS AFTER MIDNIGHT THAN WE HAVE SEEN THE PREVIOUS FEW NIGHTS. ANY LOW LEVEL MOISTURE WILL ALSO PROVE DIFFICULT TO MIX OUT IN THE MORNING GIVEN SUCH LIGHT FLOW. SO ANTICIPATE IT MAY LINGER AN HOUR OR TWO AFTER SUNRISE. FLOW WILL BE GENERALLY LIGHT AND VARIABLE THROUGH THE PERIOD. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 245 PM TUESDAY...A WEAK COLD FRONT WILL LINGER OFFSHORE WEDNESDAY NIGHT AND THURSDAY WITH COASTAL TERMINALS HAVING BETTER CHANCES OF BEING IMPACTED BY SHRA/TSRA BRINGING REDUCED CIGS/VSBYS. PREDOMINANT VFR CONDITIONS EXPECTED THURSDAY NIGHT THROUGH SATURDAY WITH ONLY ISOLATED, MAINLY DIURNALLY DRIVEN SHRA/TSRA. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 100 PM TUESDAY...MINOR ADJUSTMENTS TO POPS/WX BUT NO CHANGES TO WINDS/SEAS. /PREVIOUS DISCUSSION/ AS OF 630 AM TUESDAY...LIGHT WESTERLY BECOMING SOUTHERLY FLOW /10 KT OR LESS/ WILL OCCUR ACROSS THE NC WATERS EARLY THIS MORNING AND IS FORECAST TO CONTINUE TONIGHT IN THE WEAK GRADIENT AHEAD OF AN APPROACHING WEAK COLD FRONT. SEAS ARE FORECAST TO REMAIN 2 TO 3 FT THROUGH THE PERIOD MAINLY IN LONG PERIOD SWELL. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 250 PM TUESDAY...A WEAK COLD FRONT WILL LINGER OFFSHORE THROUGH FRIDAY, PRODUCING NE WINDS 10 KT OR LESS THROUGH THURSDAY. E/NE WINDS INCREASE SOME FRIDAY INTO FRIDAY EVENING, AROUND 10 TO 15 KT, AS GRADIENT TIGHTENS DUE TO HIGH PRESSURE BUILDING INTO THE MID-ATLANTIC REGION. THE HIGH WILL SHIFT OFF THE MID-ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY WITH WINDS BECOMING PREDOMINANTLY EASTERLY AROUND 10 KT OR LESS SATURDAY AND SUNDAY, SHIFTING SOUTHEASTERLY LATE SUNDAY. SEAS WILL RANGE 1-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR THE OUTER CENTRAL WATERS FRIDAY THROUGH SUNDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...JME/JBM SHORT TERM...JME LONG TERM...DAG AVIATION...DAG/LEP MARINE...JME/JBM/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
124 PM EDT TUE AUG 25 2015 .SYNOPSIS... A WEAK COLD FRONT APPROACHES FROM THE WEST TODAY THEN WILL STALL OVER THE AREA TONIGHT AND WEDNESDAY. THE FRONT WILL THEN SLOWLY MOVE OFF THE COAST WEDNESDAY NIGHT AND THURSDAY BUT LINGER JUST OFFSHORE INTO FRIDAY. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THIS WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 100 PM TUESDAY...UPDATED TO ADJUST POPS BASED ON LATEST RADAR TRENDS AND PRIMARIY HRRR MODEL. WEAK FRONTAL BNDRY HAS PUSHED INTO COASTAL PLAIN WITH SUFFICIENT CONVERGENCE ALONG WITH WEAK SHRT WV ENERGY TO PRODUCE SCT-BKN LINES OF SHOWERS/ISOLD TSTMS GENERALLY ALONG HWY 17. LATEST HRRR MODEL HAS GOOD HANDLE ON THIS ACTIVITY...AND INDICATES ACTIVITY GRADUALLY DEVELOPING NE AND E THROUGH MID AFTN WITH SOME ADDITIONAL DEVELOPMENT NEAR COAST AND ACROSS COASTAL PLAINS TOWARD EVENING. PW AROUND 2 INCHES AND SLOW-MOVING CELLS SUPPORT LOCALLY HEAVY RAIN...AND TRAINING AND POSSIBLY BACK-BUILDING MAY RESULT IN LOCALIZED FLOODING. MINOR ADJUSTMENTS TO TEMPS. /PREVIOUS DISCUSSION/ AS OF 630 AM TUESDAY...A SLOW MOVING UPPER LOW CENTERED OVER SOUTHERN CANADA WILL CONTINUE TO PRODUCE AN UPPER TROUGH OVER THE EASTERN US THROUGH MID WEEK. AT THE SURFACE AN EASTWARD MOVING WEAK COLD FRONT WAS LOCATED OVER CENTRAL NC. THIS FRONT WILL MOVE INTO EASTERN NC THIS AFTERNOON THEN STALL ACROSS THE AREA TONIGHT. THE AIRMASS AHEAD OF THE FRONT WILL CONTINUE TO MOISTEN WITH 850 MB DEWPOINTS IN THE MID TEENS AND PW VALUES AROUND 2" AND MEAN 1000-5000 MB RH AOA 70%. THIS HIGH MOISTURE CONTENT IN CONJUNCTION WITH FRONTAL LIFT AND WEAK MID LEVEL IMPULSES MOVING THROUGH THE UPPER LEVEL TROUGH WILL PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS ESPECIALLY THIS AFTERNOON ALTHOUGH THERE IS SOME SUPPORT FOR SOME ACTIVITY TO DEVELOP THIS MORNING AND RADAR INDICATED A LINE OF SHOWERS DEVELOPING NEAR SUNSET BEACH AND SOME LIGHTER RETURNS OVER THE COASTAL PLAIN. THE HIGH PW VALUES SHOULD SUPPORT THE FORMATION OF CONSIDERABLE CLOUDINESS WITH HEATING AND THIS WILL LIMIT HIGH TEMPERATURES SOME. THE MAIN CONVECTIVE THREAT TODAY WILL BE LOCALLY HEAVY RAINS DUE TO SLOW CELL MOVEMENT AND POSSIBLE TRAINING. HIGHS WILL BE IN THE MID TO UPPER 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... AS OF 330 AM TUESDAY...THE BEST CHANCE FOR RAIN SHOULD BE IN THE EVENING BUT WITH THE STALLED FRONT OVER THE AREA WILL NEED TO KEEP CHANCE POPS FOR THE ENTIRE NIGHT. LOWS INLAND ARE EXPECTED TO BE IN THE UPPER 60S TO LOWER 70S AND MID 70S BEACHES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 4 AM TUESDAY...AN UPPER LOW NORTH OF THE GREAT LAKES WILL PUSH EAST ACROSS QUEBEC WEDNESDAY INTO THURSDAY, ALLOWING THE UPPER TROUGH AXIS TO SHIFT EAST INTO NC BY THURSDAY THEN DE- AMPLIFYING AS IT CROSSES THE CAROLINAS LATE THURSDAY INTO THURSDAY NIGHT. AT THE SURFACE, A WEAK FRONT ACROSS EASTERN NC EARLY WEDNESDAY MORNING WILL MOVE OFF THE COAST AND STALL LATE WEDNESDAY THROUGH FRIDAY. LITTLE CHANGE IN FORECAST REASONING THROUGH THE PERIOD. CONTINUED CHANCE POPS MOST AREAS WEDNESDAY WHEN MODEST MOISTURE AND INSTABILITY SHOULD YIELD ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS ACROSS EASTERN NC. UPPER LEVEL JET STRENGTHENS ACROSS THE MID ATLANTIC AND NEW ENGLAND COAST WEDNESDAY NIGHT THROUGH THURSDAY WITH COASTAL AND OFFSHORE AREAS OF EASTERN NC POSITIONED IN THE FAVORABLE RIGHT ENTRANCE REGION OF THE JET. THE FRONTAL BOUNDARY AND DEEPEST MOISTURE REMAINS STALLED OFFSHORE THROUGH THURSDAY NIGHT AND HAVE CONTINUED SLIGHT CHANCE POPS INLAND TO HIGH CHANCE POPS COASTAL SECTIONS. THE UPPER TROUGH LIFTS NORTH OF THE REGION THURSDAY NIGHT WITH THE UPPER RIDGE ACROSS THE WESTERN ATLANTIC BUILDING WEST INTO THE SOUTHEAST FRIDAY THROUGH EARLY NEXT WEEK. MEANWHILE, SURFACE HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO SATURDAY, THEN TRANSITIONS OFFSHORE WITH THE PIEDMONT TROUGH DEVELOPING SUNDAY INTO MONDAY. EXPECT A MORE TYPICAL DIURNALLY DRIVEN, MAINLY ISOLATED SHOWER/THUNDERSTORM PATTERN THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/... HORT TERM /THROUGH 18Z WEDNESDAY/... AS OF 130 PM TUESDAY...VFR CONDITIONS EXPECTED OUTSIDE SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. MOIST SOILS, A SATURATED LOW LEVEL AIRMASS AND THE POTENTIAL FOR RADIATIONAL COOLING ARE ALL POINTING TO A HIGHER POTENTIAL FOR FOG AND IFR CONDITIONS AFTER MIDNIGHT THAN WE HAVE SEEN THE PREVIOUS FEW NIGHTS. ANY LOW LEVEL MOISTURE WILL ALSO PROVE DIFFICULT TO MIX OUT IN THE MORNING GIVEN SUCH LIGHT FLOW. SO ANTICIPATE IT MAY LINGER AN HOUR OR TWO AFTER SUNRISE. FLOW WILL BE GENERALLY LIGHT AND VARIABLE THROUGH THE PERIOD. LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 4 AM TUESDAY...SCATTERED CONVECTION POSSIBLE FOR ALL TERMINALS WITH ASSOCIATED SUB-VFR CIGS/VSBYS WEDNESDAY AS A WEAK COLD FRONT SHIFTS THROUGH THE REGION. THE FRONT LINGERS OFFSHORE WEDNESDAY NIGHT AND THURSDAY WITH COASTAL TERMINALS HAVING BETTER CHANCES OF BEING IMPACTED BY SHRA/TSRA BRINGING REDUCED CIGS/VSBYS. PREDOMINANT VFR CONDITIONS EXPECTED THURSDAY NIGHT THROUGH SATURDAY WITH ONLY ISOLATED, MAINLY DIURNALLY DRIVEN SHRA/TSRA. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 100 PM TUESDAY...MINOR ADJUSTMENTS TO POPS/WX BUT NO CHANGES TO WINDS/SEAS. /PREVIOUS DISCUSSION/ AS OF 630 AM TUESDAY...LIGHT WESTERLY BECOMING SOUTHERLY FLOW /10 KT OR LESS/ WILL OCCUR ACROSS THE NC WATERS EARLY THIS MORNING AND IS FORECAST TO CONTINUE TONIGHT IN THE WEAK GRADIENT AHEAD OF AN APPROACHING WEAK COLD FRONT. SEAS ARE FORECAST TO REMAIN 2 TO 3 FT THROUGH THE PERIOD MAINLY IN LONG PERIOD SWELL. LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 4 AM TUESDAY...A WEAK COLD FRONT WILL CROSS THE EASTERN NC COASTAL WATERS WEDNESDAY MORNING, THEN LINGER OFFSHORE THROUGH FRIDAY, PRODUCING NE WINDS 10 KT OR LESS THROUGH THURSDAY. E/NE WINDS INCREASE SOME FRIDAY INTO FRIDAY EVENING, AROUND 10 TO 15 KT, AS GRADIENTS TIGHTEN AS HIGH PRES BUILDS INTO THE MID ATLANTIC. THE HIGH WILL SHIFT OFF THE MID-ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY WITH WINDS BECOMING PREDOMINATELY EASTERLY AROUND 10 KT OR LESS SATURDAY. SEAS WILL RANGE 1-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR THE OUTER CENTRAL WATERS FRIDAY THROUGH SATURDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...JME/JBM SHORT TERM...JME LONG TERM...SK AVIATION...LEP/SK MARINE...JME/JBM/SK
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
308 PM CDT TUE AUG 25 2015 .SHORT TERM... MODEL GUIDANCE HAS NOT HANDLED WELL THE EVOLUTION OF THE CUMULUS FIELD AND ASSOCIATED SHOWER ACTIVITY WHICH HAS BEGUN TO DEVELOP. AS SUCH PATTERN RECOGNITION...WHICH IS IN MUCH BETTER AGREEMENT...IS USED PARTICULARLY THIS EVENING. UPPER LEVEL HIGH CONTINUES TO BE CENTERED JUST WEST OF THE AREA YIELDING A NORTHERLY COMPONENT TO THE LARGE SCALE FLOW. OVER THE NEXT 24 HOURS...THIS WILL TREND NORTHEASTERLY AND PROVIDE FOR DECREASING RAIN CHANCES. ACTIVITY THIS AFTERNOON SHOULD REMAIN SCATTERED TO WIDELY SCATTERED AND TAPER OFF NEAR SUNSET. GIVEN PLENTIFUL INSTABILITY...A FEW STRONG STORMS WILL BE POSSIBLE WITH SMALL HAIL AND WIND GUSTS BEING THE THREAT. HOWEVER...THIS ACTIVITY WILL BE PULSE-LIKE IN NATURE AND NO WIDESPREAD THREAT IS EXPECTED ATTM. .LONG TERM... THE ONLY RIPPLE WORTH NOTING IN THE LONG TERM FORECAST WILL BE A SHORT WAVE AT 500MB ON THURSDAY AND FRIDAY. A SHORT WAVE WILL DEVELOP IN THE ROCKIES AND MOVE OUT ONTO THE PLAINS ON THURSDAY. EFFECTS FOR THE SOUTH PLAINS WILL NOT BE TOO NOTICEABLE. THERE IS ONLY A SLIGHT DEFINITION TO THIS SHORT WAVE AT 250MB BUT MOST LIFT FROM THIS SYSTEM WILL REMAIN TO THE NORTH AND NORTHEAST. WE WILL MOSTLY BE LEFT WITH NORTHWEST FLOW ALOFT LOCALLY. MONSOONAL MOISTURE WILL BEND BACK INTO WEST TEXAS ON THURSDAY IN ADVANCE OF THIS SHORT WAVE. HOWEVER...A SURFACE TROUGH WILL BE POSITIONED WELL WEST OF THE AREA IN NEW MEXICO. A FAVORABLE NORTHWEST FLOW ALOFT MAY BE ABLE TO ADVECT THIS CONVECTIVE ACTIVITY INTO THE AREA. EVEN MORE UNCERTAIN IS THE POSITION OF A COLD FRONT ON FRIDAY. NONETHELESS...TEMPERATURES WILL STILL RUN AT OR ABOVE SEASONAL AVERAGES FOLLOWING THE PASSAGE OF THIS FRONT. THE UPPER RIDGE WILL TAKE A MORE EASTERLY JOG WITH STRONGER LONG WAVE TROUGHING ENTERING THE WEST COAST. MODELS ALSO SHOW AN EASTERLY WAVE TRYING TO UNDERCUT THE RIDGE EARLY NEXT WEEK. BUT THE POSITION OF THE RIDGE MAY BE ABLE TO BRING BACK SOME MONSOONAL TYPE THUNDERSTORMS FROM THE WEST NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 63 90 65 93 / 0 0 0 20 TULIA 63 90 66 94 / 10 0 0 10 PLAINVIEW 64 90 66 94 / 10 0 0 10 LEVELLAND 64 90 66 94 / 10 0 0 10 LUBBOCK 66 92 68 96 / 10 0 0 0 DENVER CITY 65 91 67 94 / 10 0 0 0 BROWNFIELD 65 91 68 95 / 10 0 0 0 CHILDRESS 71 95 72 100 / 10 0 0 0 SPUR 67 94 70 98 / 10 0 0 0 ASPERMONT 69 97 72 101 / 10 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 26/01
  [top] Area Forecast Discussion National Weather Service Midland/Odessa TX 247 PM CDT TUE AUG 25 2015 .DISCUSSION... Short-term focus this evening will be on the potential for isolated thunderstorms over much of west Texas and southeastern New Mexico. CAMS, and in particular the last several HRRR runs, cover much of the Permian Basin in freckles until some cold pool amalgamation promotes a few clusters. Not certain but suspect the HRRR is resolving updrafts; then again, a look to the east seems to support a consensus of the last several HRRR runs as well as the NSSL WRF. Nothing much was resolved over the Guadalupes or over the northwestern Permian Basin/central and northern Lea County where a MOGR CU field is seen in satellite imagery. All this to say that this evening`s PoPs are aligned in such a way to capture most of what the Mark 0 Mod 1 eyeball is seeing. An ingredients-based approach yields very little except for the potential for sub-severe wind gusts should an updraft persist. Look for convective activity to die off around sunset with loss of sensible heating and PBL decoupling. For Wednesday and Thursday, the consensus here is for the upper ridge to strengthen overhead. This means we can expect a warmup of around five degrees over climatology, which puts portions of the Upper Trans Pecos and the Rio Grande valley into triple-digit heat. Unless you`re fortunate enough to be in the mountains where highs will be in the 80s, the rest of us will see highs both days in the mid to upper 90s. Mid-tropospheric drying is trying to work its way southwestward but is balanced out a bit by recycled moisture from the current monsoon burst. Thus we`ll maintain low- order afternoon and evening PoPs for the mountains. Friday gets a little interesting. A short wave trough forming from the monsoon burst becomes entrained in the westerlies Thursday, then amplifies a bit in northwesterly flow aloft over the Midwest. The NAM looks to be a bit overdeveloped here while the GFS and SREF maintain a weaker trough. With the understanding that the SREF, like any ensemble model, is underdispersive and tends to smooth the edges of the ensemble envelope, this solution looks to be closer to what we expect reality to look like 84 hours out. While upper level support will be lacking, modest surface pressure rises in the wake of the aforementioned short wave trough will be enough to send a windshift down across the Texas Panhandle and perhaps become quasi-stationary over the northern Permian Basin by Friday afternoon. Again, an ingredients-based approach argues against anything significant; however, diabatic heating and weak convergence along this boundary should be enough to gin up isolated TSRA Friday afternoon and evening. Going into the weekend and next week, temperatures look to moderate some while cloudiness and afternoon/evening TSRA will remain confined to the eastern fringes of the monsoon, namely over far west Texas and the mountains and adjacent plains of southeastern New Mexico. Out beyond the extended, an expected shift toward a -PNA regime ought to shift the subtropical high east of here, while a shift toward lower heights in the north Atlantic supports carving out an upper level weakness over the southeastern states. This weakness is then carried down into the western Gulf where it becomes a TUTT low, then back north into Texas by next weekend. Rain chances may increase over the region as a result, but all this could come to naught, too. Will take a chance of something than no chance at all. && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 73 96 72 97 / 10 10 10 0 CARLSBAD NM 68 95 67 95 / 10 10 10 10 DRYDEN TX 73 101 73 100 / 10 10 10 0 FORT STOCKTON TX 70 95 71 97 / 10 10 10 0 GUADALUPE PASS TX 67 88 67 89 / 20 10 10 10 HOBBS NM 68 93 67 93 / 10 10 10 0 MARFA TX 58 89 59 89 / 10 10 10 10 MIDLAND INTL AIRPORT TX 71 96 71 98 / 10 10 10 0 ODESSA TX 72 96 72 97 / 10 10 10 0 WINK TX 72 99 72 100 / 10 10 10 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 10/70
PLEASE SEE THE 18Z AVIATION FORECAST DISCUSSION BELOW.

&& .AVIATION... THE MAIN CONCERN THROUGH THIS EVENING WILL BE THE CHANCE FOR CONVECTION ALONG AND BEHIND AN OUTFLOW BOUNDARY SET TO MOVE THROUGH THE REGION. BASED ON RADAR TRENDS AND HI-RES MODELS... WE/LL INCLUDE TEMPO GROUPS FOR OUR SITES ALONG THE I-35 CORRIDOR. TEND TO HAVE A LITTLE HIGHER CONFIDENCE IN TSRA AT AUS AND MAY HAVE TO REMOVE FROM SAT/SSF PENDING RADAR TRENDS. OUT WEST AT KDRT... WE/LL ONLY INCLUDE VCSH AS COVERAGE SHOULD BE ISOLATED. OTHERWISE...VFR CONDITIONS ARE EXPECTED OVERNIGHT AS WINDS RETURN TO A MORE EAST TO SOUTHEASTERLY DIRECTION. && .PREV DISCUSSION... /ISSUED 1051 AM CDT TUE AUG 25 2015/ UPDATE...COMPLEX OF STORMS ACROSS NORTHEAST TEXAS CONTINUE TO DROP SOUTH LATE THIS MORNING INTO EAST TEXAS. AN ASSOCIATED OUTFLOW/FRONTAL BOUNDARY ON THE SOUTHWEST SIDE OF THE COMPLEX STRETCHES ALONG ROUGHLY A HILLSBORO TO MADISONVILLE LINE...AND WILL CONTINUE TO PUSH SOUTHWEST INTO NORTHERN AND EASTERN PORTIONS OF THE CWA BY EARLY AFTERNOON. INITIALIZATION BY SEVERAL MODELS WAS POOR...BUT LATEST FEW RUNS OF THE HRRR APPEARS TO BE TRENDING BETTER. AS CONVECTIVE TEMPERATURES ARE REACHED EARLY TO MID AFTERNOON...AND WITH FORCING ASSOCIATED WITH BOUNDARY DROPPING SOUTHWEST...EXPECT ISOLATED TO SCATTERED SHOWERS AND STORMS DEVELOPING NORTH OF A FREDERICKSBURG TO SAN MARCOS TO LA GRANGE LINE...BETWEEN 1 AND 3 PM AS DEPICTED BY HRRR. OUTFLOW FROM STORMS SHOULD CONTINUE TO AID IN PUSHING THE BOUNDARY SOUTH AND WEST THROUGH THE LATE AFTERNOON...SOUTH OF I-10. BUFR SOUNDINGS SUPPORTIVE OF A FEW STRONGER DOWNDRAFTS...WITH FORECAST DCAPE VALUES OF 1300-1500 J/KG...CURRENTLY HANDLED AND MENTIONED IN THE HWO. PREV DISCUSSION... /ISSUED 357 AM CDT TUE AUG 25 2015/ SHORT TERM (TODAY THROUGH WEDNESDAY)... MID TO UPPER LEVEL RIDGE ALONG A ROCKIES INTO TEXAS AXIS SHIFTS TO A CENTRAL HIGH PLAINS INTO NORTHERN MEXICO AXIS BY WEDNESDAY AS A MID TO UPPER LEVEL TROUGH DEEPENS OVER THE EASTERN STATES. THIS ALLOWS A POOL OF DEEPER MOISTURE WITH PWS OF 1.5 TO 1.9 INCHES ALONG A FRONTAL ZONE OVER NORTHERN TEXAS TO DRIFT TO THE SOUTHWEST INTO SOUTH CENTRAL TEXAS TODAY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ON DAYTIME HEATING OVER NORTHEAST INTO CENTRAL TEXAS THIS MORNING. THEY THEN SPREAD TO THE SOUTH AND WEST ACROSS THE HILL COUNTRY AND SOUTH CENTRAL TEXAS THIS AFTERNOON AS OUTFLOW BOUNDARIES PROVIDE THE UPWARD FORCING FOR ADDITIONAL DEVELOPMENT. FORECAST SOUNDINGS AND CONVECTIVE PARAMETERS INDICATE STRONG WIND GUSTS ARE POSSIBLE. HIGH PWS INDICATE LOCALLY HEAVY DOWNPOURS WITH RAINFALL AMOUNTS UP TO ONE INCH OR SO ARE POSSIBLE. SHOWERS AND THUNDERSTORMS WANE WITH LOSS OF DAYTIME HEATING AFTER SUNSET AND SHOULD BE GONE BY MIDNIGHT. THE POOL OF MOISTURE BEGINS TO DRY FROM THE NORTHEAST AS IT DRIFTS TO THE WEST OVER SOUTH CENTRAL TEXAS ON WEDNESDAY. ONLY ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE. EACH OF MODELS APPEARS TO FAVOR A DIFFERENT AREA FOR QPF AND HAVE BROADBRUSHED THE SLIGHT CHANCES. DAYTIME TEMPERATURES CONTINUE TO BE ABOVE NORMAL. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)... MID TO UPPER LEVEL RIDGE SHIFTS TO A SOUTHWESTERN STATES INTO WESTERN TEXAS AXIS THURSDAY THROUGH SATURDAY AS A MID TO UPPER LEVEL SHORT WAVE RIDES OVER THE TOP OF IT INTO THE TROUGH OVER THE EASTERN STATES. THE POOL OF MOISTURE MOVES OFF TO THE WEST INTO MEXICO WITH PWS FALLING TO AN INCH OR LESS. NO RAIN IS EXPECTED THURSDAY THROUGH SATURDAY. AN INVERTED TROUGH PER GFS AND UPPER LOW PER ECMWF ARE FORECAST TO DEVELOP AND DRIFT TO THE WEST INTO TEXAS BY MONDAY. MOISTURE LEVELS WILL INCREASE LEADING TO SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS NEAR THE COASTAL PLAINS ON MONDAY. BEYOND THIS FORECAST...THE EVOLUTION OF THIS SYSTEM WILL DETERMINE RAIN CHANCES FOR THE MIDDLE TO END OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 75 98 73 98 73 / 10 10 - 0 0 AUSTIN BERGSTROM INTL AIRPORT 73 96 70 97 69 / 10 10 - 0 0 NEW BRAUNFELS MUNI AIRPORT 74 99 72 99 71 / 20 20 - 0 0 BURNET MUNI AIRPORT 73 96 72 97 71 / 10 10 - 0 0 DEL RIO INTL AIRPORT 76 101 77 101 75 / 20 10 10 0 0 GEORGETOWN MUNI AIRPORT 74 97 71 97 71 / 10 10 - 0 0 HONDO MUNI AIRPORT 73 99 72 98 69 / 20 20 10 0 0 SAN MARCOS MUNI AIRPORT 74 97 72 97 71 / 20 20 - 0 0 LA GRANGE - FAYETTE REGIONAL 74 96 71 97 71 / 10 10 - 0 0 SAN ANTONIO INTL AIRPORT 76 99 74 98 72 / 20 20 - 0 0 STINSON MUNI AIRPORT 76 99 73 99 72 / 20 20 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...24 SYNOPTIC/GRIDS...RUNYEN PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1249 PM CDT TUE AUG 25 2015 .DISCUSSION... 18Z TAF DISCUSSION IN AVIATION SECTION. && .AVIATION... ACTIVE RADAR THIS AFTERNOON AS OUTFLOW BOUNDARY HAS PUSHED INTO A MOIST/UNSTABLE AIRMASS RESULTING IN ISO STRONG/SEVERE STORMS. STORMS ARE MULTICELL/PULSE STORMS SO INTENSITIES WILL VARY. HAVE PUT INT VCTS/TSRA FOR ALL TERMINALS AS ALL SHOULD BE IMPACTED BY THIS LINE OF STORMS. LATEST 15Z/16Z HRRR SEEMS TO HAVE A GOOD EVOLUTION ALTHOUGH 1-2HRS BEHIND REALITY. OTHERWISE HRRR PROVIDING GOOD GUIDANCE ON EVOLUTION AND TIMING FOR TAFS. CONVECTION SHOULD BE ENDING 22-00Z THIS EVENING AS STORMS PUSH INTO THE GULF. EXPECT THERE TO BE VFR CIGS OVERNIGHT AND MAYBE SOME GROUND FOG IN RURAL TERMINALS LIKE KCXO. 39 && .PREV DISCUSSION... /ISSUED / DISCUSSION... CONVECTION CONTINUING TO DEVELOP ALONG/NEAR THE FRONTAL BOUNDARY (AND ITS OUTFLOWS) THIS MORNING AS IT MOVES INTO NRN PORTIONS OF THE CWA. NO MAJOR CHANGES WITH THE CURRENT FCST WITH THIS UPDATE AS WE SEEM TO BE ON TRACK WITH POPS/TEMPS. 41 PREV DISCUSSION... NORTHWESTERN FLOW PATTERN SET UP OVER TEXAS WITH THE 5H RIDGE CENTERED OVER THE FOUR CORNERS REGION. ENERGY OVER THE RED RIVER VALLEY SLIDING DOWN WITHIN THIS FLOW IS BEGINNING TO FIRE EARLY MORNING CONVECTION JUST SOUTH OF THE RIVER IN EXTREME NORTHEASTERN STATE. A WEAK COLD FRONT...OR AN OUTFLOW BOUNDARY PROPAGATING FROM NORTHEASTERN CONVECTION...WILL BE ENTERING OUR HEATED AND STILL VERY MOIST ENVIRONMENT (~2 INCH PWS) FROM LATE MORNING ONWARD. THE PROGGED BACKGROUND THERMODYNAMICS ARE RIPE ENOUGH TO SUPPORT STRONG...TO BORDERLINE SEVERE...AFTERNOON THUNDERSTORMS WITH THE INVERTED-V NATURE TO SOUNDINGS INDICATIVE OF A WIND THREAT. ALTHOUGH OF NOT MUCH USE OF LATE...SHORT TERM HIGH RESOLUTION MODELING THAT HAS INITIALIZED SOMEWHAT DECENTLY THIS MORNING .SUCH AS THE HRRR AND NAM12 TO SOME DEGREE...DEVELOP MID- AFTERNOON CONVECTION OVER THE NORTHWESTERN CWA AND SWATH STORM CLUSTERS NORTHEAST TO SOUTHWEST DOWN ACROSS THE MAJORITY OF THE CWA THROUGH THE AFTERNOON INTO EARLY EVENING HOURS. CONSIDERING WE ARE WITHIN AN UNWORKED OVER...UNSTABLE AIR MASS WITH AN APPROACHING BOUNDARY REACHING OUR DOORSTEP DURING THE BEST HEAT-OF-THE DAY TIME FRAME POSSIBLY INTERACTING WITH A NORTHERN ADVANCING SEA BREEZE...WILL GO AHEAD AND TAKE THE BAIT WITH THE ABOVE SCENARIO AND TAKE POPS UP TO MODERATE CHANCE. REGION REMAINS WITHIN THIS NORTHERN FLOW PATTERN AT MID-WEEK WITH THE COOLEST MID-LEVEL AIR TO HOLD OFF FROM ADVECTING IN UNTIL LATE WEDNESDAY...OR ONCE WINDS VEER MORE AROUND TO THE EAST. ONCE THIS EVENING`S PRECIPITATION WANES...THE NEXT SEVERAL DAYS WILL REMAIN DRY PER THE SLOW EASTERN MOVEMENT OF THE WESTERN RIDGE ASSERTING ITS SUBSIDENT INFLUENCE OVER THE STATE THROUGH SATURDAY. MOSTLY SUNNY TO PARTLY CLOUDY SKIES WITH RETURN FLOW LATE IN THE WORK WEEK WILL SPELL SUBSEQUENT DAILY HOT CONDITIONS. LESSENED HUMIDITY WITH THE ADVECTION OF A MUCH DRIER NORTHEASTERN AIR MASS THAT WILL BE CERTAINLY FELT IN THE EARLY THURSDAY AND FRIDAY MORNING HOURS...OVERNIGHT SURFACE TEMPERATURES WILL FALL INTO THE AVERAGE MID TO UPPER 60S WITH LOW 60S IN THE NOTORIOUS COOL SPOTS. DRY AIR WILL MAKE FOR INTERIOR AFTERNOON HEAT IN THE MID TO UPPER 90S WITH HEAT INDICES STICKING CLOSE TO AMBIENT TEMPERATURES AND ARE NOT FORECAST TO REACH THE CENTURY MARK THROUGH EARLY NEXT WEEK. SOUTHERN FORECAST AREA RAIN CHANCES WILL BEGIN TO CLIMB FROM SUNDAY ONWARD AS A MISSISSIPPI VALLEY TROUGH DOWNSTREAM OF DESERT SW RIDGING BEGINS TO SCOOT A BIT WEST AND TAP INTO A RELATIVELY HIGHER NEAR 1.5 INCH AIR MASS. 31 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 96 74 95 68 98 / 40 30 10 10 0 HOUSTON (IAH) 100 74 95 69 96 / 70 30 10 10 0 GALVESTON (GLS) 90 81 90 78 92 / 50 50 10 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...41 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1127 AM CDT TUE AUG 25 2015 .DISCUSSION... CONVECTION CONTINUING TO DEVELOP ALONG/NEAR THE FRONTAL BOUNDARY (AND ITS OUTFLOWS) THIS MORNING AS IT MOVES INTO NRN PORTIONS OF THE CWA. NO MAJOR CHANGES WITH THE CURRENT FCST WITH THIS UPDATE AS WE SEEM TO BE ON TRACK WITH POPS/TEMPS. 41 && .PREV DISCUSSION... NORTHWESTERN FLOW PATTERN SET UP OVER TEXAS WITH THE 5H RIDGE CENTERED OVER THE FOUR CORNERS REGION. ENERGY OVER THE RED RIVER VALLEY SLIDING DOWN WITHIN THIS FLOW IS BEGINNING TO FIRE EARLY MORNING CONVECTION JUST SOUTH OF THE RIVER IN EXTREME NORTHEASTERN STATE. A WEAK COLD FRONT...OR AN OUTFLOW BOUNDARY PROPAGATING FROM NORTHEASTERN CONVECTION...WILL BE ENTERING OUR HEATED AND STILL VERY MOIST ENVIRONMENT (~2 INCH PWS) FROM LATE MORNING ONWARD. THE PROGGED BACKGROUND THERMODYNAMICS ARE RIPE ENOUGH TO SUPPORT STRONG...TO BORDERLINE SEVERE...AFTERNOON THUNDERSTORMS WITH THE INVERTED-V NATURE TO SOUNDINGS INDICATIVE OF A WIND THREAT. ALTHOUGH OF NOT MUCH USE OF LATE...SHORT TERM HIGH RESOLUTION MODELING THAT HAS INITIALIZED SOMEWHAT DECENTLY THIS MORNING ..SUCH AS THE HRRR AND NAM12 TO SOME DEGREE...DEVELOP MID- AFTERNOON CONVECTION OVER THE NORTHWESTERN CWA AND SWATH STORM CLUSTERS NORTHEAST TO SOUTHWEST DOWN ACROSS THE MAJORITY OF THE CWA THROUGH THE AFTERNOON INTO EARLY EVENING HOURS. CONSIDERING WE ARE WITHIN AN UNWORKED OVER...UNSTABLE AIR MASS WITH AN APPROACHING BOUNDARY REACHING OUR DOORSTEP DURING THE BEST HEAT-OF-THE DAY TIME FRAME POSSIBLY INTERACTING WITH A NORTHERN ADVANCING SEA BREEZE...WILL GO AHEAD AND TAKE THE BAIT WITH THE ABOVE SCENARIO AND TAKE POPS UP TO MODERATE CHANCE. REGION REMAINS WITHIN THIS NORTHERN FLOW PATTERN AT MID-WEEK WITH THE COOLEST MID-LEVEL AIR TO HOLD OFF FROM ADVECTING IN UNTIL LATE WEDNESDAY...OR ONCE WINDS VEER MORE AROUND TO THE EAST. ONCE THIS EVENING`S PRECIPITATION WANES...THE NEXT SEVERAL DAYS WILL REMAIN DRY PER THE SLOW EASTERN MOVEMENT OF THE WESTERN RIDGE ASSERTING ITS SUBSIDENT INFLUENCE OVER THE STATE THROUGH SATURDAY. MOSTLY SUNNY TO PARTLY CLOUDY SKIES WITH RETURN FLOW LATE IN THE WORK WEEK WILL SPELL SUBSEQUENT DAILY HOT CONDITIONS. LESSENED HUMIDITY WITH THE ADVECTION OF A MUCH DRIER NORTHEASTERN AIR MASS THAT WILL BE CERTAINLY FELT IN THE EARLY THURSDAY AND FRIDAY MORNING HOURS...OVERNIGHT SURFACE TEMPERATURES WILL FALL INTO THE AVERAGE MID TO UPPER 60S WITH LOW 60S IN THE NOTORIOUS COOL SPOTS. DRY AIR WILL MAKE FOR INTERIOR AFTERNOON HEAT IN THE MID TO UPPER 90S WITH HEAT INDICES STICKING CLOSE TO AMBIENT TEMPERATURES AND ARE NOT FORECAST TO REACH THE CENTURY MARK THROUGH EARLY NEXT WEEK. SOUTHERN FORECAST AREA RAIN CHANCES WILL BEGIN TO CLIMB FROM SUNDAY ONWARD AS A MISSISSIPPI VALLEY TROUGH DOWNSTREAM OF DESERT SW RIDGING BEGINS TO SCOOT A BIT WEST AND TAP INTO A RELATIVELY HIGHER NEAR 1.5 INCH AIR MASS. 31 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 95 68 98 68 / 20 10 10 0 0 HOUSTON (IAH) 74 95 69 96 71 / 20 10 10 0 0 GALVESTON (GLS) 81 90 78 92 80 / 20 10 10 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 PM CDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 325 PM CDT TUE AUG 25 2015 CHALLENGES TONIGHT THROUGH WEDNESDAY INCLUDE CLOUD TRENDS... TEMPERATURES AND FOG POTENTIAL. SOME DIFFERENCES BETWEEN MODELS WITH REGARD TO HOW QUICKLY CLOUDS DISSIPATE AND MOVE OUT TONIGHT... BUT OTHERWISE IN GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION. 25.20Z SURFACE LOW ACROSS SOUTHERN HUDSON BAY WILL FINALLY BEGIN TO LIFT NORTH AND EAST TONIGHT...ALLOWING EXPANSIVE STRATOCUMULUS DECK ACROSS THE ENTIRE GREAT LAKES REGION TO SLOWLY MOVE OUT OF THE FORECAST AREA. 25.18Z RAP 1 KM 90 PERCENT RELATIVE HUMIDITY CONTOUR HAS BEEN A GOOD PROXY TO CURRENT CLOUD COVER AND SHOWS MOST CLOUDS DISSIPATE AND/OR MOVE EAST OF THE FORECAST AREA BY 25.06Z. THIS IDEA IS ALSO SUPPORTED BY LATEST NSSL SYNTHETIC IR...SO EXPECT CLEARING TO OVERSPREAD THE FORECAST AREA OVERNIGHT. WITH LIGHT WINDS DEEPENING TO AROUND 2000 FT AGL BY 25.09Z...THINK SOME VALLEY FOG IS POSSIBLE AND WILL CONTINUE TO MENTION IN LATEST FORECAST. TEMPERATURES TONIGHT WILL BOTTOM OUT FROM THE MID 40S TO LOWER 50S. WEDNESDAY WILL BE MOSTLY SUNNY AND DRY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE UPPER MS RIVER VALLEY. WINDS WILL BE LIGHT FROM THE NORTH-NORTHWEST WITH AFTERNOON HIGHS INTO THE UPPER 60S TO MID 70S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM CDT TUE AUG 25 2015 SURFACE RIDGE AXIS MOVES OVER LAKE MICHIGAN BY 25.12Z...BUT LIGHT WINDS WILL CONTINUE THROUGH THE MORNING...DEEPENING TO NEARLY 6000 FT AGL. FOG POTENTIAL WILL HINGE ON POSSIBLE HIGH CLOUDS...BUT OTHERWISE A GOOD CHANCE AND WILL KEEP MENTION OF PATCHY VALLEY FOG. CLOUD COVER AND SOUTHERLY WINDS WILL INCREASE THROUGH THE DAY ON THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. ANY PRECIPITATION WILL REMAIN WEST OF THE FORECAST AREA...EXCEPT FOR A SMALL CHANCE LATE IN THE EVENING MAINLY WEST OF THE HIGHWAY 52 CORRIDOR. RISING 925 TO 850 HPA TEMPERATURES WILL ALLOW AFTERNOON HIGHS TO REACH THE MID TO UPPER 70S. FRIDAY NOW LIKELY TO BE CLOUDY AND WET AS AN EASTERN PACIFIC TROUGH UNDERCUTS THE WESTERN CONUS 500 HPA RIDGE AND MOVES INTO THE UPPER MIDWEST. 25.12Z MODEL SUITE PRODUCES A WELL DEFINED DEFORMATION PRECIPITATION AXIS ALONG ENHANCED 850 TO 700 HPA FRONTOGENESIS NORTH OF THE SURFACE LOW. ALTHOUGH THE GFS/ECMWF SURFACE LOW TRACKS ARE SIMILAR...MOVING FROM EAST-CENTRAL NE ACROSS SOUTHERN IA THROUGH THE DAY...THE ECMWF PAINTS THE HIGHEST RAINFALL A BIT FARTHER SOUTH COMPARED TO THE GFS/NAM WHICH ARE HIGHEST ACROSS THE FORECAST AREA. THE PAST THREE RUNS OF THE GFS HAVE BEEN SIMILAR...LENDING HIGHER CONFIDENCE TO ITS NORTHERN SOLUTION. WILL INCREASE POPS INTO THE LIKELY CATEGORY ON FRIDAY. HOWEVER...INSTABILITY STILL LOOKS VERY WEAK AND WILL CAP THUNDERSTORM CHANCES TO 20 PERCENT WITH LIGHT TO MODERATE SHOWERS BEING THE DOMINATE MODE. STILL A BIT EARLY TO GET TOO SPECIFIC WITH RAINFALL AMOUNTS...BUT SOME AREAS COULD SEE AMOUNTS IN EXCESS OF AN INCH THROUGH FRIDAY NIGHT. WITH CLOUDS AND RAIN... FRIDAY WILL BE COOL WITH HIGHS IN THE UPPER 60S TO NEAR 70 DEGREES. SOME LINGERING SHOWERS POSSIBLE SATURDAY...ESPECIALLY EAST OF THE MS RIVER...BUT OTHERWISE SHOULD SEE IMPROVING CONDITIONS WITH DECREASING CLOUD COVER AND RAIN CHANCES FROM WEST TO EAST. HIGHS WILL REBOUND BACK INTO THE MID 70S. SUNDAY THROUGH TUESDAY LOOK DRY WITH NO MAJOR SYSTEMS ON THE HORIZON. BIGGER CONCERN WILL BE RISING TEMPERATURES AS 500 HPA RIDGE AXIS FOLDS OVER ACROSS THE UPPER MIDWEST...RESULTING IN TEMPERATURES RISING INTO THE LOWER TO MID 80S BY THE EARLY PART OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1220 PM CDT TUE AUG 25 2015 BACK EDGE OF STUBBORN MVFR STRATOCUMULUS CURRENTLY HUGGING THE MISSISSIPPI RIVER...INCLUDING KLSE AND POINTS EAST. LOOK FOR THIS FIELD OF STRATOCUMULUS TO ERODE EASTWARD THROUGH THE AFTERNOON WITH KLSE SCATTERING OUT AROUND 20Z. BREEZY NORTHWEST WINDS WILL SUBSIDE BY EVENING AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTHERN PLAINS. THE RIDGE OF HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA TONIGHT WITH DECENT DECOUPLING EXPECTED IN THE MISSISSIPPI RIVER VALLEY LATE TONIGHT. AS A RESULT...CONFIDENCE IS FAIRLY HIGH ON SOME FOG DEVELOPMENT ON THE MISSISSIPPI CHANNEL GIVEN LIGHT/VARIABLE WINDS AND CLEAR SKIES BUT LOW CONFIDENCE FOG WILL ACTUALLY SET UP AT KLSE. FOR NOW...WENT WITH P6SM BCFG AT KLSE IN THE 10-14Z TIME FRAME AND WILL LET THE EVENING FORECASTER ASSESS FURTHER. OTHERWISE...VFR CONDITIONS EXPECTED UNDER THE RIDGE OF HIGH PRESSURE THROUGH TOMORROW. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ROGERS LONG TERM...ROGERS AVIATION...DAS