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:
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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