Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/18/12
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1020 PM EDT TUE JUL 17 2012
.SYNOPSIS...
HOT AND HUMID WEATHER WILL PERSIST THROUGH WEDNESDAY. A COLD FRONT
WILL BRING A ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT WHICH WILL BREAK THE HEAT
AND HUMIDITY. SOME STORMS MAY CONTAIN STRONG WINDS AND HEAVY
DOWNPOURS. SEASONABLE TEMPERATURES AND LOWER HUMIDITY WILL FOLLOW
THURSDAY INTO SATURDAY. WARMER AND MORE HUMID CONDITIONS WILL
RETURN SUNDAY INTO MONDAY ALONG AND AHEAD OF ANOTHER COLD FRONT.
&&
.NEAR TERM /UNTIL 5 AM WEDNESDAY MORNING/...
1030 PM UPDATE...
SHOWERS/TSTMS IN EASTERN NEW YORK MOVING EAST-SOUTHEAST TOWARD
SOUTHERN VT/SOUTHERN NH/NORTHWEST MASS. WE HAVE ADJUSTED POPS IN
OUR NORTHWEST AREAS TO LIKELY WITH VALUES DIMINISHING SOUTH AND
EAST. CHANCE POPS EXTEND TO NORTHEAST MASS NORTH OF BOSTON THROUGH
1 AM. HRRR FORECAST REFLECTIVITY ACTUALLY FOLLOWS THIS LINE OF
THOUGHT. ANTICIPATE THAT THE PCPN WILL DIMINISH AFTER 1 AM AS IT
MOVES INTO DIMINISHING SURFACE BASED CAPE...BUT LESS THAN CERTAIN
DUE TO MOISTURE POOLING OVER EASTERN NY.
OTHERWISE EXPECT A VERY WARM AND MUGGY NIGHT AHEAD WITH INCREASING
DEW PTS AS BLYR MIXING SUBSIDES AND SSW WINDS BECOME MORE WSW /WARM
LAND TRAJECTORY/. PATCHY FOG POSSIBLE BUT THIS LAND TRAJECTORY WIND
DIRECTION SHOULD LIMIT AREAL COVERAGE OF ANY FOG.
&&
.SHORT TERM /5 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WED...
FRONTAL BOUNDARY SAGS SOUTHWARD INTO SOUTHERN NEW ENGLAND.
SUFFICIENT FRONTAL SCALE FORCING AND WEAK SYNOPTIC SCALE LIFT FOR
WIDESPREAD SHOWERS AND TSTMS DURING THE AFTERNOON...ESPECIALLY
ACROSS CT/RI AND SOUTH OF I-90 IN MA. MID LEVEL TEMPS BEGIN TO COOL
SO CAP/LID SHOULD ERODE PROMOTING STRONG UPDRAFTS ALONG WITH ML
CAPES OF 1500-2500J/KG. THIS COMBINED WITH STRONG DEEP LAYER SHEAR
AND INVERTED V SIGNATURE ON MODEL SOUNDINGS SUPPORT RISK OF STRONG
TO DAMAGING WINDS. IN ADDITION PWATS CLIMBING TO +2 STD ABOVE
CLIMO..K INDICES MU30S ALONG WITH MID LEVEL FLOW BECOMING PARALLEL
TO FRONT SUGGEST HEAVY DOWNPOURS ALONG WITH A RISK OF FLASH FLOODING
ESPECIALLY IN THE URBAN AREAS OF HFD-PVD-EWB.
HOTTEST TEMPS WED WILL BE ACROSS CT/RI AND SOUTHEAST MA AWAY FROM
THE IMMEDIATE SHORE AS THIS AREA WILL RECEIVE THE LONGEST DURATION
OF SUNSHINE WITH CLOUDS ADVANCING FROM NORTH TO SOUTH. SO ANOTHER
ROUND OF +90 TEMPS ESP OVER CT/RI AND SOUTH OF I-90 IN MA.
WED NIGHT...
FRONTAL BOUNDARY WILL BE SLOW TO MOVE OFFSHORE SO EXPECTING STRONG
STORMS INTO THE EVENING. AS BLYR COOLS RISK OF DAMAGING WINDS WILL
LIKELY DIMINISH BUT FLASH FLOOD THREAT WILL CONTINUE AS FRONTAL WAVE
TRIES TO DEVELOP ON THE BOUNDARY. SO RELIEF FROM HEAT AND HUMIDTY
UNTIL SOMETIME THU AS AIRMASS CHANGE WON/T HAPPEN UNTIL THEN.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* SHOWERS AND THUNDERSTORMS SLIDE SOUTH THURSDAY
* SEASONABLE AND LESS HUMID CONDITIONS PERSIST INTO SATURDAY
* HEAT AND HUMIDITY BUILD BACK NORTH SUNDAY
* COLD FRONT WITH SHOWERS AND THUNDERSTORMS EXPECTED MONDAY
THURSDAY AND THURSDAY NIGHT...
SFC COLD FRNT SLIDES GRADUALLY S OF NEW ENGLAND REMAINING A FOCUS OF
SHOWERS AND THUNDERSTORMS. ITS PLAUSIBLE TO SEE ACTIVITY LINGER
INITIALLY ALONG THE S SHORELINE...RENEWED AGAIN DURING THE EVNG.
BOUNDARY LYR WILL BE WELL-MIXED BEYOND H85...AND HEIGHT FALLS WILL
PROCEED AROUND H5 AS THE MAIN TROF AXIS AND ATTENDANT SHRTWV ENERGY
SLIDES S THRU NEW ENGLAND INTO FRI MORN. SLGT CHC POPS WARRANTED.
SFC HIGH PRES BUILDING OUT OF CANADA WITH ATTENDANT COOLER AIRMASS.
SFC TEMPS LIKELY COOLER /MAY SEE SOME EFFECTIVE NOCTURNAL COOLING
DURING THE EVNG PDS/.
FRIDAY AND SATURDAY...
THERE IS SOME HINT WITHIN FCST GUIDANCE OF ISOLATED SHOWER ACTIVITY
TO DEVELOP ACROSS THE INTERIOR FOR FRIDAY INTO EARLY SATURDAY
/MORESO WITH THE 12Z GFS/. BUT IN EVALUATING...WHILE THE MAIN H5
TROF AXIS SWEEPS ACROSS THE RGN...HEIGHT RISES ARE APPARENT AS SFC
HIGH PRES REMAINS OVER S NEW ENGLAND SQUEEZED BETWEEN TWO DISTURBED
WX SYSTEMS. AGREE WITH PREV FORECASTERS ANALYSIS OF PREVAILING NWLY
FLOW OF A CONTINENTAL POLAR AIRMASS USHERING DRIER AND COOLER AIR
ACROSS THE RGN THRU THE ATMOS COLUMN. IN ADDITION FEEL SUBSIDENCE
WILL BE IN CONTROL KEEPING THE RGN DRY. VERY COMFORTABLE TEMPS
ANTICIPATED. WINDS BECOMING SLY LATE SAT INTO SUN MORN AS SFC HIGH
PRES SHIFTS OFFSHORE.
SUNDAY INTO MONDAY...
SFC COLD FRNT WITH ATTENDANT TROF AXIS ALOFT SWEEPS ACROSS NEW
ENGLAND AROUND MONDAY MORNING /THERE IS SOME MDL DISCREPANCY ON
TIMING AND EVOLUTION/. SLY FLOW ALONG AND AHEAD SHOULD ADVECT
SLIGHTLY WARMER AND HUMID CONDITIONS ACROSS NEW ENGLAND. THUS
SHOWERS AND THUNDERSTORMS ARE ANTICIPATED THOUGH THE NATURE AND
SEVERITY OF WHICH REMAINS UNCERTAIN.
INTO THE MIDWEEK...
HIGH PRES BUILDS BACK ACROSS INTO NEW ENGLAND AS ANOTHER AREA OF LOW
PRES AND ATTENDANT COLD FRNT SWEEPS THROUGH THE GREAT LAKES RGN.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE TO HIGH CONFIDENCE.
PREVAILING VFR. TSRA EXPECTED TO IMPACT S NH INTO NRN MA THROUGH
05Z. BETTER CHC FOR SHRA-TSRA TO BEGIN AROUND 15Z INTO THE EARLY
EVNG PD ALONG AND AHEAD OF A COLD FRNT THAT WILL DROP S OF NEW
ENGLAND CLOSER TOWARDS MIDNIGHT. TSRA MAY BECOME STRONG TO SEVERE
WITH THE MAIN THREATS BEING DAMAGING WINDS AND HEAVY DOWNPOURS.
INTERMITTANT GUSTY WINDS AND VSBY IMPACTS ARE TO BE EXPECTED...YET
CONFIDENCE ON SPECIFICS IS LOW. IMPROVED CONDITIONS INTO THURS.
KBOS TAF...MODERATE TO HIGH CONFIDENCE.
VFR WITH SOUTHWEST FLOW THROUGH THE NIGHT. AREA OF SHOWERS/TSTMS
WILL MOVE ACROSS NH AND NORTHERN MASS. CURRENTLY EXPECT THESE TO
PASS NORTH OF BOSTON THROUGH 06Z BUT WILL BE WATCHING. QUIET THE
REMAINDER OF THE NIGHT. SEA-BREEZE PSBL INTO THE MIDDAY PD WITH
RENEWED THREAT OF SHRA/TSTM MIDDAY AND AFTERNOON.
KBDL TAF...MODERATE TO HIGH CONFIDENCE.
INCREASING RISK OF STRONG TO SEVERE TSRA TOWARDS THE MIDDAY INTO
AFTN PD. DAMAGING WINDS PSBL WITH HEAVY DOWNPOURS WHICH WILL
LIKELY LEAD TO VSBY IMPACTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND THURSDAY NIGHT...
MODERATE TO HIGH CONFIDENCE VFR. SOME LINGERING SHRA FOR THE S
SHORELINE TERMINALS.
FRIDAY AND SATURDAY...
HIGH CONFIDENCE VFR. LGT AND VRB WINDS. SEA-BREEZES ALONG SHORELINES.
SUNDAY...
HIGH CONFIDENCE VFR. RETURN SLY FLOW. APPROACHING COLD FRNT. PSBL
SHRA/TSRA YET LOW CONFIDENCE.
&&
.MARINE...
TONIGHT...
SCA ALLOWED TO EXPIRE. WINDS AND SEAS SHOULD DIMINISH OVERNIGHT.
LOW RISK OF AN ISOLATED TSTM FROM THROUGH 2 AM ON THE WATERS NORTH
OF BOSTON. OTHERWISE DRY WEATHER.
WED...
LGT/VRB WINDS AS FRONTAL BOUNDARY/COLD FRONT SAGS SOUTH INTO THE
WATERS. TSTMS WILL BECOME NUMEROUS DURING THE AFTN AND A FEW STRONG
STORMS LIKELY WITH GUSTY WINDS AND HEAVY DOWNPOURS.
WED NIGHT...
COLD FRONT SAGS SLOWLY SOUTH...SO TSTMS WILL CONTINUE ACROSS THE
SOUTHERN WATERS. A FEW STRONG TSTMS POSSIBLE.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND THURSDAY NIGHT...
A MODEST NELY FLOW AROUND 15 KTS WILL RESULT IN 5 FT SEAS FOR THE
OUTER MARKERS TO THE FAR OFFSHORE WATERS S/SE OF CAPE COD. EXPECTING
CONTINUED SCT SHOWERS/THUNDERSTORMS FOR THE EARLY PD...PUSHING S
THRU THE DAY AND WELL OFFSHORE BY EVNG.
FRIDAY INTO SUNDAY...
HIGH PRES IN CONTROL. ELY FLOW AROUND 10-15 KTS WITH SEAS REMAINING
BELOW 5 FT. WINDS WILL GRADUALLY TRANSITION OUT OF THE S LATE SAT
INTO SUN.
&&
.CLIMATE...
RECORD HIGHS FOR TUE JUL 17...
BOS...98 IN 1999 AND PREVIOUS YEARS
PVD...97 IN 1999 AND PREVIOUS YEARS
BDL...97 IN 1999
ORH...93 IN 1900
RECORD HIGHS FOR WED JUL 18...
BOS...98...1982
ORH...93...1982 AND PREVIOUS YEARS
BDL...99...1982
PVD...98...1999 AND PREVIOUS YEARS
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ020>024.
NH...NONE.
RI...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR RIZ002>008.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...WTB/NOCERA/SIPPRELL
SHORT TERM...NOCERA
LONG TERM...SIPPRELL
AVIATION...NOCERA/SIPPRELL
MARINE...NOCERA/SIPPRELL
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1018 PM EDT TUE JUL 17 2012
.SYNOPSIS...
HOT AND HUMID WEATHER WILL PERSIST THROUGH WEDNESDAY. A COLD FRONT
WILL BRING A ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT WHICH WILL BREAK THE HEAT
AND HUMIDITY. SOME STORMS MAY CONTAIN STRONG WINDS AND HEAVY
DOWNPOURS. SEASONABLE TEMPERATURES AND LOWER HUMIDITY WILL FOLLOW
THURSDAY INTO SATURDAY. WARMER AND MORE HUMID CONDITIONS WILL
RETURN SUNDAY INTO MONDAY ALONG AND AHEAD OF ANOTHER COLD FRONT.
&&
.NEAR TERM /UNTIL 5 AM WEDNESDAY MORNING/...
1030 PM UPDATE...
SHOWERS/TSTMS IN EASTERN NEW YORK MOVING EAST-SOUTHEAST TOWARD
SOUTHERN VT/SOUTHERN NH/NORTHWEST MASS. WE HAVE ADJUSTED POPS IN
OUR NORTHWEST AREAS TO LIKELY WITH VALUES DIMINISHING SOUTH AND
EAST. CHANCE POPS EXTEND TO NORTHEAST MASS NORTH OF BOSTON THROUGH
1 AM. HRRR FORECAST REFLECTIVITY ACTUALLY FOLLOWS THIS LINE OF
THOUGHT. ANTICIPATE THAT THE PCPN WILL DIMINISH AFTER 1 AM AS IT
MOVES INTO DIMINISHING SURFACE BASED CAPE...BUT LESS THAN CERTAIN
DUE TO MOISTURE POOLING OVER EASTERN NY.
OTHERWISE EXPECT A VERY WARM AND MUGGY NIGHT AHEAD WITH INCREASING
DEW PTS AS BLYR MIXING SUBSIDES AND SSW WINDS BECOME MORE WSW /WARM
LAND TRAJECTORY/. PATCHY FOG POSSIBLE BUT THIS LAND TRAJECTORY WIND
DIRECTION SHOULD LIMIT AREAL COVERAGE OF ANY FOG.
&&
.SHORT TERM /5 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WED...
FRONTAL BOUNDARY SAGS SOUTHWARD INTO SOUTHERN NEW ENGLAND.
SUFFICIENT FRONTAL SCALE FORCING AND WEAK SYNOPTIC SCALE LIFT FOR
WIDESPREAD SHOWERS AND TSTMS DURING THE AFTERNOON...ESPECIALLY
ACROSS CT/RI AND SOUTH OF I-90 IN MA. MID LEVEL TEMPS BEGIN TO COOL
SO CAP/LID SHOULD ERODE PROMOTING STRONG UPDRAFTS ALONG WITH ML
CAPES OF 1500-2500J/KG. THIS COMBINED WITH STRONG DEEP LAYER SHEAR
AND INVERTED V SIGNATURE ON MODEL SOUNDINGS SUPPORT RISK OF STRONG
TO DAMAGING WINDS. IN ADDITION PWATS CLIMBING TO +2 STD ABOVE
CLIMO..K INDICES MU30S ALONG WITH MID LEVEL FLOW BECOMING PARALLEL
TO FRONT SUGGEST HEAVY DOWNPOURS ALONG WITH A RISK OF FLASH FLOODING
ESPECIALLY IN THE URBAN AREAS OF HFD-PVD-EWB.
HOTTEST TEMPS WED WILL BE ACROSS CT/RI AND SOUTHEAST MA AWAY FROM
THE IMMEDIATE SHORE AS THIS AREA WILL RECEIVE THE LONGEST DURATION
OF SUNSHINE WITH CLOUDS ADVANCING FROM NORTH TO SOUTH. SO ANOTHER
ROUND OF +90 TEMPS ESP OVER CT/RI AND SOUTH OF I-90 IN MA.
WED NIGHT...
FRONTAL BOUNDARY WILL BE SLOW TO MOVE OFFSHORE SO EXPECTING STRONG
STORMS INTO THE EVENING. AS BLYR COOLS RISK OF DAMAGING WINDS WILL
LIKELY DIMINISH BUT FLASH FLOOD THREAT WILL CONTINUE AS FRONTAL WAVE
TRIES TO DEVELOP ON THE BOUNDARY. SO RELIEF FROM HEAT AND HUMIDTY
UNTIL SOMETIME THU AS AIRMASS CHANGE WON/T HAPPEN UNTIL THEN.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* SHOWERS AND THUNDERSTORMS SLIDE SOUTH THURSDAY
* SEASONABLE AND LESS HUMID CONDITIONS PERSIST INTO SATURDAY
* HEAT AND HUMIDITY BUILD BACK NORTH SUNDAY
* COLD FRONT WITH SHOWERS AND THUNDERSTORMS EXPECTED MONDAY
THURSDAY AND THURSDAY NIGHT...
SFC COLD FRNT SLIDES GRADUALLY S OF NEW ENGLAND REMAINING A FOCUS OF
SHOWERS AND THUNDERSTORMS. ITS PLAUSIBLE TO SEE ACTIVITY LINGER
INITIALLY ALONG THE S SHORELINE...RENEWED AGAIN DURING THE EVNG.
BOUNDARY LYR WILL BE WELL-MIXED BEYOND H85...AND HEIGHT FALLS WILL
PROCEED AROUND H5 AS THE MAIN TROF AXIS AND ATTENDANT SHRTWV ENERGY
SLIDES S THRU NEW ENGLAND INTO FRI MORN. SLGT CHC POPS WARRANTED.
SFC HIGH PRES BUILDING OUT OF CANADA WITH ATTENDANT COOLER AIRMASS.
SFC TEMPS LIKELY COOLER /MAY SEE SOME EFFECTIVE NOCTURNAL COOLING
DURING THE EVNG PDS/.
FRIDAY AND SATURDAY...
THERE IS SOME HINT WITHIN FCST GUIDANCE OF ISOLATED SHOWER ACTIVITY
TO DEVELOP ACROSS THE INTERIOR FOR FRIDAY INTO EARLY SATURDAY
/MORESO WITH THE 12Z GFS/. BUT IN EVALUATING...WHILE THE MAIN H5
TROF AXIS SWEEPS ACROSS THE RGN...HEIGHT RISES ARE APPARENT AS SFC
HIGH PRES REMAINS OVER S NEW ENGLAND SQUEEZED BETWEEN TWO DISTURBED
WX SYSTEMS. AGREE WITH PREV FORECASTERS ANALYSIS OF PREVAILING NWLY
FLOW OF A CONTINENTAL POLAR AIRMASS USHERING DRIER AND COOLER AIR
ACROSS THE RGN THRU THE ATMOS COLUMN. IN ADDITION FEEL SUBSIDENCE
WILL BE IN CONTROL KEEPING THE RGN DRY. VERY COMFORTABLE TEMPS
ANTICIPATED. WINDS BECOMING SLY LATE SAT INTO SUN MORN AS SFC HIGH
PRES SHIFTS OFFSHORE.
SUNDAY INTO MONDAY...
SFC COLD FRNT WITH ATTENDANT TROF AXIS ALOFT SWEEPS ACROSS NEW
ENGLAND AROUND MONDAY MORNING /THERE IS SOME MDL DISCREPANCY ON
TIMING AND EVOLUTION/. SLY FLOW ALONG AND AHEAD SHOULD ADVECT
SLIGHTLY WARMER AND HUMID CONDITIONS ACROSS NEW ENGLAND. THUS
SHOWERS AND THUNDERSTORMS ARE ANTICIPATED THOUGH THE NATURE AND
SEVERITY OF WHICH REMAINS UNCERTAIN.
INTO THE MIDWEEK...
HIGH PRES BUILDS BACK ACROSS INTO NEW ENGLAND AS ANOTHER AREA OF LOW
PRES AND ATTENDANT COLD FRNT SWEEPS THROUGH THE GREAT LAKES RGN.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE TO HIGH CONFIDENCE.
PREVAILING VFR. TSRA EXPECTED TO IMPACT S NH INTO NRN MA THROUGH
05Z. BETTER CHC FOR SHRA-TSRA TO BEGIN AROUND 15Z INTO THE EARLY
EVNG PD ALONG AND AHEAD OF A COLD FRNT THAT WILL DROP S OF NEW
ENGLAND CLOSER TOWARDS MIDNIGHT. TSRA MAY BECOME STRONG TO SEVERE
WITH THE MAIN THREATS BEING DAMAGING WINDS AND HEAVY DOWNPOURS.
INTERMITTANT GUSTY WINDS AND VSBY IMPACTS ARE TO BE EXPECTED...YET
CONFIDENCE ON SPECIFICS IS LOW. IMPROVED CONDITIONS INTO THURS.
KBOS TAF...MODERATE TO HIGH CONFIDENCE.
VFR WITH SOUTHWEST FLOW THROUGH THE NIGHT. AREA OF SHOWERS/TSTMS
WILL MOVE ACROSS NH AND NORTHERN MASS. CURRENTLY EXPECT THESE TO
PASS NORTH OF BOSTON THROUGH 06Z BUT WILL BE WATCHING. QUIET THE
REMAINDER OF THE NIGHT. SEA-BREEZE PSBL INTO THE MIDDAY PD WITH
RENEWED THREAT OF SHRA/TSTM MIDDAY AND AFTERNOON.
KBDL TAF...MODERATE TO HIGH CONFIDENCE.
INCREASING RISK OF STRONG TO SEVERE TSRA TOWARDS THE MIDDAY INTO
AFTN PD. DAMAGING WINDS PSBL WITH HEAVY DOWNPOURS WHICH WILL
LIKELY LEAD TO VSBY IMPACTS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND THURSDAY NIGHT...
MODERATE TO HIGH CONFIDENCE VFR. SOME LINGERING SHRA FOR THE S
SHORELINE TERMINALS.
FRIDAY AND SATURDAY...
HIGH CONFIDENCE VFR. LGT AND VRB WINDS. SEA-BREEZES ALONG SHORELINES.
SUNDAY...
HIGH CONFIDENCE VFR. RETURN SLY FLOW. APPROACHING COLD FRNT. PSBL
SHRA/TSRA YET LOW CONFIDENCE.
&&
.MARINE...
TONIGHT...
SCA ALLOWED TO EXPIRE. WINDS AND SEAS SHOULD DIMINISH OVERNIGHT.
LOW RISK OF AN ISOLATED TSTM FROM THROUGH 2 AM ON THE WATERS NORTH
OF BOSTON. OTHERWISE DRY WEATHER.
WED...
LGT/VRB WINDS AS FRONTAL BOUNDARY/COLD FRONT SAGS SOUTH INTO THE
WATERS. TSTMS WILL BECOME NUMEROUS DURING THE AFTN AND A FEW STRONG
STORMS LIKELY WITH GUSTY WINDS AND HEAVY DOWNPOURS.
WED NIGHT...
COLD FRONT SAGS SLOWLY SOUTH...SO TSTMS WILL CONTINUE ACROSS THE
SOUTHERN WATERS. A FEW STRONG TSTMS POSSIBLE.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY AND THURSDAY NIGHT...
A MODEST NELY FLOW AROUND 15 KTS WILL RESULT IN 5 FT SEAS FOR THE
OUTER MARKERS TO THE FAR OFFSHORE WATERS S/SE OF CAPE COD. EXPECTING
CONTINUED SCT SHOWERS/THUNDERSTORMS FOR THE EARLY PD...PUSHING S
THRU THE DAY AND WELL OFFSHORE BY EVNG.
FRIDAY INTO SUNDAY...
HIGH PRES IN CONTROL. ELY FLOW AROUND 10-15 KTS WITH SEAS REMAINING
BELOW 5 FT. WINDS WILL GRADUALLY TRANSITION OUT OF THE S LATE SAT
INTO SUN.
&&
.CLIMATE...
RECORD HIGHS FOR TUE JUL 17...
BOS...98 IN 1999 AND PREVIOUS YEARS
PVD...97 IN 1999 AND PREVIOUS YEARS
BDL...97 IN 1999
ORH...93 IN 1900
RECORD HIGHS FOR WED JUL 18...
BOS...98...1982
ORH...93...1982 AND PREVIOUS YEARS
BDL...99...1982
PVD...98...1999 AND PREVIOUS YEARS
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ020>024.
NH...NONE.
RI...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR RIZ002>008.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
ANZ230>237-251.
&&
$$
SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...WTB/NOCERA/SIPPRELL
SHORT TERM...NOCERA
LONG TERM...SIPPRELL
AVIATION...NOCERA/SIPPRELL
MARINE...NOCERA/SIPPRELL
CLIMATE...
AREA FORECAST DISCUSSION
NWS ALBANY NY
759 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 745 PM...HEAT ADVISORY HAS BEEN ALLOWED TO EXPIRE. NO OTHER
CHANGES AT THIS TIME.
AS OF 7 PM...CONTINUING TO WATCH CONVECTIVE TRENDS ACROSS PORTIONS
OF THE DACKS. LATEST MESOSCALE ANALYSIS REVEALS AN OUTFLOW BOUNDARY
ACROSS THE TUG HILL...INTO NORTHERN HERKIMER AND HAMILTON COUNTIES.
SBCAPES ARE NEAR 2000 J/KG AND 0-6KM SHEAR WAS BETWEEN 40-50KTS.
FURTHER SOUTH OF THIS CONVECTION...SBCAPES ARE A BIT HIGHER BUT SO
ARE THE MID LEVEL TEMPS WITH 700MB TEMPS AT +10C TO +12C PER SPC/RAP
HOURLY UPDATES. SO THE QUESTION REMAINS JUST HOW FAR SOUTH THIS
CONVECTION WILL MAKE IT BEFORE WE LOSE THE DAYTIME HEATING AND/OR IT
OUTRUNS THE BETTER SHEAR PROFILES. SO FOR THIS UPDATE...WE WILL
DECREASE POPS THROUGH THE EVENING. HOWEVER...THE FRONTAL BOUNDARY
CONTINUES TO SLOWLY SAG SOUTHWARD OVERNIGHT SO WE CAN NOT RULE OUT
ADDITIONAL CONVECTION OVERNIGHT. THE HRRR REFLECTIVITY FORECASTS
SUGGEST WE COULD SEE SOME ADDITIONAL CONVECTION OVERNIGHT ACROSS THE
MOHAWK VALLEY AND INTO THE CAPITAL REGION.
AS FOR TEMPERATURES...THE COMBINATION OF AN ANTICYLONIC RIDGE SEEN
IN THE H2O VAPOR AND DOWNSLOPING FROM THE SOUTHWEST WIND
TRAJECTORIES...MAY AREAS IN THE VALLEYS QUICKLY CLIMBED INTO THE MID
AND UPPER 90S WITH DEWPOINT POOLING INTO THE HUDSON RIVER VALLEY.
GIVEN A RATHER MUGGY EVENING...WE WILL HOLD ONTO THE HEAT ADVISORY
AT THIS TIME.
PREV DISC...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AFTER A LATE NIGHT LUL IN CONVECTION MDL SUITE IN AGREEMENT WITH
CDFNT BEGINNING THE DAY IN MHWK VLY AND CONTINUING SWRD.
CONVECTION FIRES MID DAY...WITH MAIN THREAT S & E OF ALB. WITH S
AREAS IN BETTER JET DYNAMICS...JUXTAPOSED TO CDFNT AND CAPES
REBUILDING TO 1500-3000 J/KG ASSORTED GUIDANCE INDICATES THE
LIKELY LOCATIONS FOR A SVR CONVECTION THREAT WILL BE SOUTH OF
ALBANY.
VARIATIONS IN CLOUD COVER COULD DAMPEN THIS RESPONSE AND LOCAL WRF
DOESN`T GET CONVECTION WELL ORGANIZED TILL ITS STRADDLING THE
SOUTH TIER OF COUNTIES WED.
WITH PWATS STILL IN THE 1.50-2.00 INCH RANGE SOUTH SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA.
FURTHER N WED TEMPS WILL REMAIN ABV NORMALS ONE MORE DAY BUT
DRIER AIR WILL BE FILTERING INTO N TIER WITH CLEARING.
WED NT CDFNT MOVES S OF FCA...MOST OF AREA CLEARS AND DRIES..HWVR
CLOUDS MAY LINGER OVER S PTNS OF FCA. WHAT WILL BE VERY NOTICEABLE
IS DEPARTURE OF HUMIDITY AS TD DROP INTO 50S.
BY THU LARGE SFC HIGH BUILDS SE INTO FCA FM ONT/HUD BAY WITH FAIR
AND SEASONABLE CONDS ACROSS ENTIRE FCA INTO THU NT.
A RECENT WRINKLE IN NAM/GFS IS THE FORMATION OF A WAVE ALONG THE
STALLED FRONT TO OUR SOUTH LATE THU AND FRI OVER S VA. WHILE NOT
AS VIGOROUS AS THE 06UTC RUNS,..THE CURRENT SUITE BRINGS INCRG
CLOUDS AND CHC -SHRA TO S TIER OF FCA LATE FRI.
WILL POPULATE THIS PERIOD WITH MET/MAV BLEND AS GUID IN CLOSE
AGREEMENT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A NICE START TO THE WEEKEND AS A RIDGE OF HIGH PRESSURE WILL BE OVER
THE REGION ON SATURDAY. THE GFS WANTS TO LINGER ONTO THE UPPER TROF
AXIS AND RESULTS IN ISOLATED CONVECTION ACROSS THE REGION.
HOWEVER...THE GFS ALSO HINTS AT RISING HEIGHTS WHICH IS ALONG THE
SAME AS OTHER GLOBAL GUIDANCE. WE WILL RETAIN THE DRY FORECAST
ALONG WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES.
THEN TRENDS ON SUNDAY ARE BECOMING A LITTLE MORE ACTIVE...BUT NOT A
WASHOUT. ANOTHER SHORTWAVE WITHIN THE NORTHWEST FLOW REGIME ALOFT
IS EXPECTED TO TRACK TOWARD THE GREAT LAKES REGION LATER ON SUNDAY.
AT THIS TIME...WE WILL INTRODUCE A SLIGHT CHANCE FOR CONVECTION AND
CONTINUE TO MONITOR TRENDS. BY SUNDAY NIGHT...ALL OF THE AVAILABLE
GUIDANCE SUGGESTS A PV ANOMALY CROSSES THE REGION. WE WILL HAVE THE
HIGHER POPS...30-40 PERCENT...AT THIS TIME ACROSS MOST OF THE REGION
SUNDAY NIGHT.
BY MONDAY...THAT PV ANOMALY DOES TRACK EAST YET THE CYCLONIC FLOW
REGIME REMAINS IN PLACE. THE ECMWF/DGEX WANTS TO LINGER A SURFACE
TROUGH ACROSS THE REGION WHILE THE GFS IS THE MOST AGGRESSIVE TO
CLEAR OUT OF OUR SOUTHERN COUNTIES. HPC GUIDANCE IS SOMEWHAT IN THE
MIDDLE OF THE GUIDANCE ENVELOPE AND HAVE FOLLOWED THE GUIDANCE
CLOSELY. TEMPERATURES AND DEWPOINTS WILL BE ON THE CLIMB AS WELL AS
WE AVERAGE TOWARD ABOVE NORMAL INTO EARLY NEXT WEEK.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS HAVE BEEN CONFINED TO FAR NORTHERN AREAS
TODAY AS A COLD FRONT DROPS SOUTH FROM CANADA. AN ISOLATED
THUNDERSTORM IS NOT OUT OF THE QUESTION FURTHER SOUTH BUT QUESTION
IS HOW FAR SOUTH DO STORMS MOVE? BEST CHANCE AT KGFL LATE THIS
EVENING BUT ENOUGH UNCERTAINTY TO LEAVE OUT OF TAF. MODELS SHOW MOST
CONVECTION DYING OUT OVERNIGHT BUT SOME ISOLATED RAIN SHOWERS AND
FOG AND STRATO CU EXPECTED AS MOISTURE POOLS AHEAD OF COLD FRONT.
FOR TOMORROW...COLD FRONT CONTINUES TO MOVE SOUTH WITH BEST CHANCE
OF SHOWERS/THUNDERSTORMS OVER SOUTHERN AREAS AS COLD FRONT CONTINUES
SOUTH BEFORE CLEARING AREA DURING EVENING.
WEST SOUTHWEST WINDS 10 TO 15 KTS THIS EVENING SUBSIDING TO 3 TO 6
KTS OVERNIGHT. FOR WEDNESDAY...WINDS WEST TO NORTHWEST BECOMING
NORTHWEST TO NORTH AT 5 TO 10 KTS.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTM.
&&
.FIRE WEATHER...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL INCREASE TO 80 TO 100 PERCENT
TONIGHT..AND RECOVER TO 40-60 PERCENT WEDNESDAY AFTERNOON. VALES
WEDNESDAY WILL INCREASE TO 60-80 PERCENT.
SOUTHWEST WINDS 10 TO 15 MPH WITH HIGHER GUSTS WILL BECOME LIGHT
AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM THE
WEST NORTHWEST TO 5 TO 15 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TONIGHT INTO WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A
SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN THE
1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
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...SNYDER
NEAR TERM...BGM/SNYDER
SHORT TERM...SNYDER
LONG TERM...BGM
AVIATION...SND
FIRE WEATHER...SNYDER
HYDROLOGY...WASULA/SNYDER
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
721 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 7 PM...CONTINUING TO WATCH CONVECTIVE TRENDS ACROSS PORTIONS
OF THE DACKS. LATEST MESOSCALE ANALYSIS REVEALS AN OUTFLOW BOUNDARY
ACROSS THE TUG HILL...INTO NORTHERN HERKIMER AND HAMILTON COUNTIES.
SBCAPES ARE NEAR 2000 J/KG AND 0-6KM SHEAR WAS BETWEEN 40-50KTS.
FURTHER SOUTH OF THIS CONVECTION...SBCAPES ARE A BIT HIGHER BUT SO
ARE THE MID LEVEL TEMPS WITH 700MB TEMPS AT +10C TO +12C PER SPC/RAP
HOURLY UPDATES. SO THE QUESTION REMAINS JUST HOW FAR SOUTH THIS
CONVECTION WILL MAKE IT BEFORE WE LOSE THE DAYTIME HEATING AND/OR IT
OUTRUNS THE BETTER SHEAR PROFILES. SO FOR THIS UPDATE...WE WILL
DECREASE POPS THROUGH THE EVENING. HOWEVER...THE FRONTAL BOUNDARY
CONTINUES TO SLOWLY SAG SOUTHWARD OVERNIGHT SO WE CAN NOT RULE OUT
ADDITIONAL CONVECTION OVERNIGHT. THE HRRR REFLECTIVITY FORECASTS
SUGGEST WE COULD SEE SOME ADDITIONAL CONVECTION OVERNIGHT ACROSS THE
MOHAWK VALLEY AND INTO THE CAPITAL REGION.
AS FOR TEMPERATURES...THE COMBINATION OF AN ANTICYLONIC RIDGE SEEN
IN THE H2O VAPOR AND DOWNSLOPING FROM THE SOUTHWEST WIND
TRAJECTORIES...MAY AREAS IN THE VALLEYS QUICKLY CLIMBED INTO THE MID
AND UPPER 90S WITH DEWPOINT POOLING INTO THE HUDSON RIVER VALLEY.
GIVEN A RATHER MUGGY EVENING...WE WILL HOLD ONTO THE HEAT ADVISORY
AT THIS TIME.
PREV DISC...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AFTER A LATE NIGHT LUL IN CONVECTION MDL SUITE IN AGREEMENT WITH
CDFNT BEGINNING THE DAY IN MHWK VLY AND CONTINUING SWRD.
CONVECTION FIRES MID DAY...WITH MAIN THREAT S & E OF ALB. WITH S
AREAS IN BETTER JET DYNAMICS...JUXTAPOSED TO CDFNT AND CAPES
REBUILDING TO 1500-3000 J/KG ASSORTED GUIDANCE INDICATES THE
LIKELY LOCATIONS FOR A SVR CONVECTION THREAT WILL BE SOUTH OF
ALBANY.
VARIATIONS IN CLOUD COVER COULD DAMPEN THIS RESPONSE AND LOCAL WRF
DOESN`T GET CONVECTION WELL ORGANIZED TILL ITS STRADDLING THE
SOUTH TIER OF COUNTIES WED.
WITH PWATS STILL IN THE 1.50-2.00 INCH RANGE SOUTH SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA.
FURTHER N WED TEMPS WILL REMAIN ABV NORMALS ONE MORE DAY BUT
DRIER AIR WILL BE FILTERING INTO N TIER WITH CLEARING.
WED NT CDFNT MOVES S OF FCA...MOST OF AREA CLEARS AND DRIES..HWVR
CLOUDS MAY LINGER OVER S PTNS OF FCA. WHAT WILL BE VERY NOTICEABLE
IS DEPARTURE OF HUMIDITY AS TD DROP INTO 50S.
BY THU LARGE SFC HIGH BUILDS SE INTO FCA FM ONT/HUD BAY WITH FAIR
AND SEASONABLE CONDS ACROSS ENTIRE FCA INTO THU NT.
A RECENT WRINKLE IN NAM/GFS IS THE FORMATION OF A WAVE ALONG THE
STALLED FRONT TO OUR SOUTH LATE THU AND FRI OVER S VA. WHILE NOT
AS VIGOROUS AS THE 06UTC RUNS,..THE CURRENT SUITE BRINGS INCRG
CLOUDS AND CHC -SHRA TO S TIER OF FCA LATE FRI.
WILL POPULATE THIS PERIOD WITH MET/MAV BLEND AS GUID IN CLOSE
AGREEMENT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A NICE START TO THE WEEKEND AS A RIDGE OF HIGH PRESSURE WILL BE OVER
THE REGION ON SATURDAY. THE GFS WANTS TO LINGER ONTO THE UPPER TROF
AXIS AND RESULTS IN ISOLATED CONVECTION ACROSS THE REGION.
HOWEVER...THE GFS ALSO HINTS AT RISING HEIGHTS WHICH IS ALONG THE
SAME AS OTHER GLOBAL GUIDANCE. WE WILL RETAIN THE DRY FORECAST
ALONG WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES.
THEN TRENDS ON SUNDAY ARE BECOMING A LITTLE MORE ACTIVE...BUT NOT A
WASHOUT. ANOTHER SHORTWAVE WITHIN THE NORTHWEST FLOW REGIME ALOFT
IS EXPECTED TO TRACK TOWARD THE GREAT LAKES REGION LATER ON SUNDAY.
AT THIS TIME...WE WILL INTRODUCE A SLIGHT CHANCE FOR CONVECTION AND
CONTINUE TO MONITOR TRENDS. BY SUNDAY NIGHT...ALL OF THE AVAILABLE
GUIDANCE SUGGESTS A PV ANOMALY CROSSES THE REGION. WE WILL HAVE THE
HIGHER POPS...30-40 PERCENT...AT THIS TIME ACROSS MOST OF THE REGION
SUNDAY NIGHT.
BY MONDAY...THAT PV ANOMALY DOES TRACK EAST YET THE CYCLONIC FLOW
REGIME REMAINS IN PLACE. THE ECMWF/DGEX WANTS TO LINGER A SURFACE
TROUGH ACROSS THE REGION WHILE THE GFS IS THE MOST AGGRESSIVE TO
CLEAR OUT OF OUR SOUTHERN COUNTIES. HPC GUIDANCE IS SOMEWHAT IN THE
MIDDLE OF THE GUIDANCE ENVELOPE AND HAVE FOLLOWED THE GUIDANCE
CLOSELY. TEMPERATURES AND DEWPOINTS WILL BE ON THE CLIMB AS WELL AS
WE AVERAGE TOWARD ABOVE NORMAL INTO EARLY NEXT WEEK.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS HAVE BEEN CONFINED TO FAR NORTHERN AREAS
TODAY AS A COLD FRONT DROPS SOUTH FROM CANADA. AN ISOLATED
THUNDERSTORM IS NOT OUT OF THE QUESTION FURTHER SOUTH BUT QUESTION
IS HOW FAR SOUTH DO STORMS MOVE? BEST CHANCE AT KGFL LATE THIS
EVENING BUT ENOUGH UNCERTAINTY TO LEAVE OUT OF TAF. MODELS SHOW MOST
CONVECTION DYING OUT OVERNIGHT BUT SOME ISOLATED RAIN SHOWERS AND
FOG AND STRATO CU EXPECTED AS MOISTURE POOLS AHEAD OF COLD FRONT.
FOR TOMORROW...COLD FRONT CONTINUES TO MOVE SOUTH WITH BEST CHANCE
OF SHOWERS/THUNDERSTORMS OVER SOUTHERN AREAS AS COLD FRONT CONTINUES
SOUTH BEFORE CLEARING AREA DURING EVENING.
WEST SOUTHWEST WINDS 10 TO 15 KTS THIS EVENING SUBSIDING TO 3 TO 6
KTS OVERNIGHT. FOR WEDNESDAY...WINDS WEST TO NORTHWEST BECOMING
NORTHWEST TO NORTH AT 5 TO 10 KTS.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTM.
&&
.FIRE WEATHER...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL INCREASE TO 80 TO 100 PERCENT
TONIGHT..AND RECOVER TO 40-60 PERCENT WEDNESDAY AFTERNOON. VALES
WEDNESDAY WILL INCREASE TO 60-80 PERCENT.
SOUTHWEST WINDS 10 TO 15 MPH WITH HIGHER GUSTS WILL BECOME LIGHT
AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM THE
WEST NORTHWEST TO 5 TO 15 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TONIGHT INTO WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A
SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN THE
1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
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...SNYDER
NEAR TERM...BGM/SNYDER
SHORT TERM...SNYDER
LONG TERM...BGM
AVIATION...SND
FIRE WEATHER...SNYDER
HYDROLOGY...WASULA/SNYDER
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
715 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 7 PM...CONTINUING TO WATCH CONVECTIVE TRENDS ACROSS PORTIONS
OF THE DACKS. LATEST MESOSCALE ANALYSIS REVEALS AN OUTFLOW BOUNDARY
ACROSS THE TUG HILL...INTO NORTHERN HERKIMER AND HAMILTON COUNTIES.
SBCAPES ARE NEAR 2000 J/KG AND 0-6KM SHEAR WAS BETWEEN 40-50KTS.
FURTHER SOUTH OF THIS CONVECTION...SBCAPES ARE A BIT HIGHER BUT SO
ARE THE MID LEVEL TEMPS WITH 700MB TEMPS AT +10C TO +12C PER SPC/RAP
HOURLY UPDATES. SO THE QUESTION REMAINS JUST HOW FAR SOUTH THIS
CONVECTION WILL MAKE IT BEFORE WE LOSE THE DAYTIME HEATING AND/OR IT
OUTRUNS THE BETTER SHEAR PROFILES. SO FOR THIS UPDATE...WE WILL
DECREASE POPS THROUGH THE EVENING. HOWEVER...THE FRONTAL BOUNDARY
CONTINUES TO SLOWLY SAG SOUTHWARD OVERNIGHT SO WE CAN NOT RULE OUT
ADDITIONAL CONVECTION OVERNIGHT. THE HRRR REFLECTIVITY FORECASTS
SUGGEST WE COULD SEE SOME ADDITIONAL CONVECTION OVERNIGHT ACROSS THE
MOHAWK VALLEY AND INTO THE CAPITAL REGION.
AS FOR TEMPERATURES...THE COMBINATION OF AN ANTICYLONIC RIDGE SEEN
IN THE H2O VAPOR AND DOWNSLOPING FROM THE SOUTHWEST WIND
TRAJECTORIES...MAY AREAS IN THE VALLEYS QUICKLY CLIMBED INTO THE MID
AND UPPER 90S WITH DEWPOINT POOLING INTO THE HUDSON RIVER VALLEY.
GIVEN A RATHER MUGGY EVENING...WE WILL HOLD ONTO THE HEAT ADVISORY
AT THIS TIME.
PREV DISC...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AFTER A LATE NIGHT LUL IN CONVECTION MDL SUITE IN AGREEMENT WITH
CDFNT BEGINNING THE DAY IN MHWK VLY AND CONTINUING SWRD.
CONVECTION FIRES MID DAY...WITH MAIN THREAT S & E OF ALB. WITH S
AREAS IN BETTER JET DYNAMICS...JUXTAPOSED TO CDFNT AND CAPES
REBUILDING TO 1500-3000 J/KG ASSORTED GUIDANCE INDICATES THE
LIKELY LOCATIONS FOR A SVR CONVECTION THREAT WILL BE SOUTH OF
ALBANY.
VARIATIONS IN CLOUD COVER COULD DAMPEN THIS RESPONSE AND LOCAL WRF
DOESN`T GET CONVECTION WELL ORGANIZED TILL ITS STRADDLING THE
SOUTH TIER OF COUNTIES WED.
WITH PWATS STILL IN THE 1.50-2.00 INCH RANGE SOUTH SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA.
FURTHER N WED TEMPS WILL REMAIN ABV NORMALS ONE MORE DAY BUT
DRIER AIR WILL BE FILTERING INTO N TIER WITH CLEARING.
WED NT CDFNT MOVES S OF FCA...MOST OF AREA CLEARS AND DRIES..HWVR
CLOUDS MAY LINGER OVER S PTNS OF FCA. WHAT WILL BE VERY NOTICEABLE
IS DEPARTURE OF HUMIDITY AS TD DROP INTO 50S.
BY THU LARGE SFC HIGH BUILDS SE INTO FCA FM ONT/HUD BAY WITH FAIR
AND SEASONABLE CONDS ACROSS ENTIRE FCA INTO THU NT.
A RECENT WRINKLE IN NAM/GFS IS THE FORMATION OF A WAVE ALONG THE
STALLED FRONT TO OUR SOUTH LATE THU AND FRI OVER S VA. WHILE NOT
AS VIGOROUS AS THE 06UTC RUNS,..THE CURRENT SUITE BRINGS INCRG
CLOUDS AND CHC -SHRA TO S TIER OF FCA LATE FRI.
WILL POPULATE THIS PERIOD WITH MET/MAV BLEND AS GUID IN CLOSE
AGREEMENT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A NICE START TO THE WEEKEND AS A RIDGE OF HIGH PRESSURE WILL BE OVER
THE REGION ON SATURDAY. THE GFS WANTS TO LINGER ONTO THE UPPER TROF
AXIS AND RESULTS IN ISOLATED CONVECTION ACROSS THE REGION.
HOWEVER...THE GFS ALSO HINTS AT RISING HEIGHTS WHICH IS ALONG THE
SAME AS OTHER GLOBAL GUIDANCE. WE WILL RETAIN THE DRY FORECAST
ALONG WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES.
THEN TRENDS ON SUNDAY ARE BECOMING A LITTLE MORE ACTIVE...BUT NOT A
WASHOUT. ANOTHER SHORTWAVE WITHIN THE NORTHWEST FLOW REGIME ALOFT
IS EXPECTED TO TRACK TOWARD THE GREAT LAKES REGION LATER ON SUNDAY.
AT THIS TIME...WE WILL INTRODUCE A SLIGHT CHANCE FOR CONVECTION AND
CONTINUE TO MONITOR TRENDS. BY SUNDAY NIGHT...ALL OF THE AVAILABLE
GUIDANCE SUGGESTS A PV ANOMALY CROSSES THE REGION. WE WILL HAVE THE
HIGHER POPS...30-40 PERCENT...AT THIS TIME ACROSS MOST OF THE REGION
SUNDAY NIGHT.
BY MONDAY...THAT PV ANOMALY DOES TRACK EAST YET THE CYCLONIC FLOW
REGIME REMAINS IN PLACE. THE ECMWF/DGEX WANTS TO LINGER A SURFACE
TROUGH ACROSS THE REGION WHILE THE GFS IS THE MOST AGGRESSIVE TO
CLEAR OUT OF OUR SOUTHERN COUNTIES. HPC GUIDANCE IS SOMEWHAT IN THE
MIDDLE OF THE GUIDANCE ENVELOPE AND HAVE FOLLOWED THE GUIDANCE
CLOSELY. TEMPERATURES AND DEWPOINTS WILL BE ON THE CLIMB AS WELL AS
WE AVERAGE TOWARD ABOVE NORMAL INTO EARLY NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS WILL BE PRIMARILY CONFINED TO FAR NORTHERN
AREAS LATER TODAY AND TONIGHT AS A COLD FRONT DROPS SOUTH FROM
CANADA. AN ISOLATED THUNDERSTORM IS NOT OUT OF THE QUESTION FURTHER
SOUTH BUT TO LOW OF PROBABILITY TO MENTION IN A TAF. INCREASING
SOUTHWEST WINDS ARE EXPECTED TO RESULT IN DOWNSLOPING IN THE HUDSON
VALLEY WHICH SHOULD ALSO HELP LIMIT CONVECTIVE ACTIVITY FOR MOST OF
THE TAF SITES. THE BEST CHANCE OF THUNDERSTORMS WILL BE AT KGFL LATE
THIS AFTERNOON INTO EARLY THIS EVENING. MODELS SHOW MOST CONVECTION
DYING OUT OVERNIGHT BUT SOME ISOLATED RAIN SHOWERS AND FOG AND
STRATO CU EXPECTED AS MOISTURE POOLS AHEAD OF COLD FRONT. FOR
TOMORROW...COLD FRONT CONTINUES TO MOVE SOUTH WITH BEST CHANCE OF
THUNDERSTORMS OVER SOUTHERN AREAS AS COLD FRONT CONTINUES SOUTH.
SOUTHWEST WINDS 10 TO 15 KTS BY AFTERNOON SUBSIDING TO 3 TO 6 KTS
THIS EVENING. FOR WEDNESDAY...WINDS WEST TO NORTHWEST BECOMING
NORTHWEST TO NORTH AT 5 TO 10 KTS.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTM.
&&
.FIRE WEATHER...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL INCREASE TO 80 TO 100 PERCENT
TONIGHT..AND RECOVER TO 40-60 PERCENT WEDNESDAY AFTERNOON. VALES
WEDNESDAY WILL INCREASE TO 60-80 PERCENT.
SOUTHWEST WINDS 10 TO 15 MPH WITH HIGHER GUSTS WILL BECOME LIGHT
AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM THE
WEST NORTHWEST TO 5 TO 15 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TONIGHT INTO WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A
SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN THE
1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
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...SNYDER
NEAR TERM...BGM/SNYDER
SHORT TERM...SNYDER
LONG TERM...BGM
AVIATION...
FIRE WEATHER...SNYDER
HYDROLOGY...WASULA/SNYDER
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
418 PM EDT MON JUL 16 2012
.SYNOPSIS...
HOT CONDITIONS WILL PREVAIL ACROSS THE REGION ON TUESDAY. A COLD
FRONT WILL APPROACH FROM THE NORTH TUESDAY AFTERNOON AND EVENING.
THE FRONT WILL BE A SLOW MOVER...NOT CLEARING THE AREA UNTIL
WEDNESDAY AFTERNOON. HIGH PRESSURE WILL BUILD INTO NEW YORK AND
NEW ENGLAND FROM HUDSON/S BAY TO END THE WEEK...WITH FAIR DRY
WEATHER...MUCH MORE COMFORTABLE HUMIDITY...AND NEAR NORMAL
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ISOLATED SHOWERS HAVE STARTED TO DIMINISH ACROSS THE REGION. HAVE
NOT NOTED ANY THUNDER YET. HI RES RUC LOOKS TO BE OVERDONE
THROUGH THE EVENING WITH PERSISTENT SHRA AND TSRA. HAVE ALLOWED
FOR ISOLATED SHRA/TSRA INTO THE EVENING...THEN MAINLY DRY
OVERNIGHT. WILL CONTINUE WITH MENTION OF PATCHY FOG.
MAV/MET BLEND FOR OVERNIGHT LOWS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
LOW PRESSURE WILL TRACK ACROSS QUEBEC ON TUESDAY. TOWARD SUNRISE
THERE IS A SLIGHT CHANCE OF SOME SHRA/TSRA ACROSS FAR NORTHERN
ZONES. BETTER PRECIP WILL BE ALIGNED WITH LOW LEVEL JET THAT
PUSHES INTO ONTARIO AND QUEBEC. AS THE LOW TRACKS EASTWARD A WARM
FRONT WILL SWEEP ACROSS THE REGION. 850MB TEMPS WILL RISE TO 20C
OR HIGHER ON TUESDAY. A COLD FRONT TRAILING THE LOW WILL BEGIN A
SLOW SAG INTO NORTHERN NEW YORK AND NEW ENGLAND. SPC HAS NORTHERN
TIER OF CWA IN SLIGHT RISK FOR TOMORROW. NAM IS PARTICULARLY
AGGRESSIVE WITH SURFACE BASED CAPES UPWARDS OF 3000 J/KG BY
AFTERNOON ACROSS HAMILTON/HERKIMER COUNTIES. SHEAR IS 30-40
KNOTS...SO AMPLE DYNAMICS AVAILABLE TO FUEL SOME SEVERE STORMS.
GFS SOMEWHAT LESS EXCITED ABOVE INSTABILITY. NAM SURFACE DEW
POINTS ARE PROBABLY A COUPLE OF DEGREES TO HIGH. EVEN
SO...COMBINATION OF MODERATE CAPE AND SUFFICIENT DYNAMICS NEEDS TO
BE RESPECTED. IN ADDITION...PRECIPITABLE WATERS INCREASE TO NEAR
TWO INCHES TOMORROW ACROSS MUCH OF THE CWA...AND REMAIN THERE
THROUGH WEDNESDAY. SO...ANY STORMS THAT DEVELOP...COULD DELIVER A
GOOD SOAKING...ALTHOUGH STEERING WINDS ARE RESPECTABLE...SO STORMS
SHOULD CONTINUE TO MOVE ALONG. WITH THESE IDEAS IN MIND...HAVE
INSERTED MENTION OF SEVERE POTENTIAL FOR
HERKIMER...HAMILTON...WARREN COUNTY...AND WILL INCLUDE IN HWO. AS FAR
AS TEMPS GO TOMORROW...MAV/MET GUIDANCE HAS COME INTO PRETTY GOOD
AGREEMENT ON MAX TEMPS AND DEW POINTS. FOR NOW...HAVE NOT ISSUED
ANY HEAT ADVISORIES AS DEW POINTS LOOK TO REMAIN IN THE 60S EVEN
AS TEMPERATURES CLIMB INTO THE MID 90S MOST VALLEY LOCATIONS.
FRONT WILL CONTINUE TO MOVE SLOWLY SOUTH TUESDAY NIGHT INTO
WEDNESDAY. WITH TEMPERATURES REMAINING WARM ON TUESDAY
NIGHT...COULD STILL SEE ONGOING THUNDERSTORM ACTIVITY ACROSS THE
NORTHERN CWA. BY WEDNESDAY FRONT WILL MOVE THROUGH SOUTHERN HALF
OF THE CWA. NAM IS AGGRESSIVE IN PAINTING A SWATH OF HIGH CAPE
ACROSS SOUTHERN HALF OF THE CWA LATE WEDNESDAY MORNING INTO
AFTERNOON. THERE IS POTENTIAL HERE AGAIN FOR SEVERE STORMS AS 0-6
KM WILL BE RESPECTABLE 30-40 KNOTS...COMBINED WITH MODERATE TO HIGH
INSTABILITY. SPC DAY 3 HAS THIS AREA IN /SEE TEXT/ WITH 5 PERCENT
PROBABILITY FOR SEVERE. NO ENHANCED WORDING IN ZONES AT THIS
TIME...BUT WILL BE MENTIONED IN HWO. DEPENDING ON TIMING OF
FRONT/CLOUDS/PRECIP ANOTHER HOT DAY IS POSSIBLE FOR THE AREA SOUTH
OF THE CAPITAL DISTRICT. FORECAST HEAT INDICES REACH TO NEAR 100
IN THE MID HUDSON VALLEY. SO WILL HIGHLIGHT THIS THREAT IN HWO
TOO.
FRONT WILL CLEAR CWA BY WEDNESDAY AFTERNOON.
DRIER/COOLER AIR WILL FILTER INTO THE REGION FOR THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A TRANQUIL PERIOD OF WEATHER IS EXPECTED WITH TEMPERATURES AVERAGING
NEAR TO SLIGHTLY BELOW NORMAL.
UPPER LEVEL TROUGH AXIS WILL DIVE SOUTHWARD THROUGH THE END OF THIS
WEEK WITH THE DEEPER MOISTURE PROFILES ASSOCIATED WITH THE FRONT
SOUTH OF THE CWFA. DEWPOINTS WILL BE RATHER COMFORTABLE AS 850MB
TEMPS SETTLE BACK TO AOA +10C/+12C INTO THE WEEKEND. SURFACE
PRESSURES BUILD TO AT LEAST 1020MB WITH EXPECTATIONS OF A FEW
DIURNALLY DRIVEN CU AND A MOCLR SKY AT NIGHT. MOS/HPC MODEL BLEND
GUIDANCE WAS UTILIZED WITH TOPOGRAPHIC EFFECTS IMPLEMENTED FOR THE
HIGHER TERRAIN WITH RESPECT TO TEMPERATURES.
AS THE SURFACE HIGH SLIDES SOUTHWARD TOWARD THE MID ATLANTIC SUNDAY
NIGHT...A WARM FRONT ADVANCES EAST FOR THE START OF NEXT WEEK. THIS
WILL INCREASE OUR THERMAL PROFILES AS RETURN TO INCREASING SURFACE
TEMPERATURES AND DEWPOINTS.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
SCATTERED SHOWERS HAVE DEVELOPED ACROSS THE FORECAST AREA. KGFL HAD A
LIGHT RAIN SHOWER AND ONLY RECORDED A TRACE OF PRECIPITATION. LEFT
RAIN SHOWERS/TSRA OUT OF TAFS FOR TODAY. LOW PROBABILITY THAT ANY
TAF SITE WILL SEE EVEN MVFR FROM A SHOWER THIS AFTERNOON BUT A
SHOWER/TSRA IS POSSIBLE.
EXPECT SOME FOG TONIGHT BUT CLOUD COVER MAY MODULATE HOW WIDESPREAD
AND HOW DENSE. THICK CIRRUS FROM UPSTREAM CONVECTIVE COMPLEX MAY
PREVENT DENSE FOG FROM FORMING AS IT PREVENTS STRONG RADIATIONAL
COOLING. PLENTY OF ATMOSPHERIC MOISTURE AROUND...SO TAF SITES THAT
CLEAR OUT OVERNIGHT WILL SEE FOG. FOR NOW FORECAST GENERALLY 2-4
MILES VISBY WITH FOG LATER TONIGHT EARLY MORNING.
WEST TO NORTHWEST WINDS AT 8-12 KTS BY MIDDAY AND THEN LIGHT AND
VARIABLE AGAIN TONIGHT. TOMORROW...SOUTHWEST WINDS 5 TO 10 MPH.
OUTLOOK...
MON-WED...VFR/MVFR. ISOLD-SCT SHOWERS/TSTMS.
THU-FRI...VFR...NO SIG WX.
&&
.FIRE WEATHER...
ISOLATED SHOWERS WILL TAPER OFF THIS EVENING. ON TUESDAY...SHOWERS
AND THUNDERSTORMS ARE POSSIBLE LATE IN THE DAY INTO WEDNESDAY. THESE
COULD BRING ANOTHER 0.5 TO 1.0 INCH OF RAIN TO MANY AREAS.
WEAK HIGH PRESSURE WILL CREST OVER THE NORTHEAST TODAY AND TONIGHT.
TUESDAY AND WEDNESDAY A STRONG BACK DOOR COLD FRONT WILL SLOWLY DROP
FROM THE SAINT LAWRENCE VALLEY TO THE NEW ENGLAND
COAST...RESULTING IN SHOWERS AND THUNDERSTORMS.
RELATIVE HUMIDITY VALUES WILL BE 90-100 PERCENT TONIGHT AND
TUESDAY NIGHT WITH PATCHY FOG...RECOVERING TO THE MODERATE LEVELS
OF 40 TO 60 PERCENT TUESDAY AFTERNOON.
&&
.HYDROLOGY...
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE LIKELY LATER TUESDAY
INTO WEDNESDAY. ALTHOUGH NO RIVER FLOODING IS EXPECTED...THESE
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL.
SO...THE THREAT OF SOME URBAN OR SMALL STREAM FLOODING WILL
ACCOMPANY ANY THUNDERSTORMS THAT DEVELOP.
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...OKEEFE
NEAR TERM...OKEEFE
SHORT TERM...OKEEFE
LONG TERM...BGM
AVIATION...SND
FIRE WEATHER...OKEEFE
HYDROLOGY...OKEEFE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
712 AM EDT MON JUL 16 2012
.SYNOPSIS...
HOT AND HUMID WEATHER WILL PERSIST THROUGH WEDNESDAY...WITH
TUESDAY BEING THE HOTTEST DAY THIS WEEK. A COLD FRONT WILL BRING A
ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY. SEASONABLE
TEMPERATURES AND LOWER HUMIDITY WILL FOLLOW THURSDAY INTO NEXT
WEEKEND AS A HIGH PRESSURE BUILDS IN FROM CANADA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
ALL SHOWERS HAVE LEFT THE AREA. EXPECT PATCHY FOG...MAINLY MID CT
RIVER VALLEY AREA...TO DISSIPATE BY MID MORNING. ALTHOUGH HRR AND
OTHER MESOSCALE MODELS SUGGESTING POPCORN CONVECTION...CONCUR WITH
PRIOR FORECAST REASONING THAT RIDGING BEHIND SHORT WAVE TROF AND
UNIMPRESSIVE LOW TO MID LEVEL LAPSE RATES SUGGEST AFTERNOON
CONVECTION UNLIKELY TODAY. CANNOT RULE OUT AN ISOLATED SHOWER
ALONG SEA BREEZE BOUNDARY OR OVER HIGHER TERRAIN BUT DOES NOT EVEN
SEEM TO WARRANT SLIGHT CHANCE. PRIOR FORECAST OF TEMPS LOOKS TO BE
ON TRACK.
SMALL LINE OF SHOWERS/STORMS FORMED ALONG S COAST EARLY THIS
MORNING IN AN AREA OF GOOD MOISTURE CONVERGENCE AND LEFTOVER
INSTABILITY. MAIN THREAT WITH THESE STORMS IS BRIEFLY HEAVY
RAIN...AND THEY WILL EXIT COAST BY 4 AM.
OTHERWISE CLOUDS AND PATCHY FOG WILL PREVAIL THROUGH DAYBREAK DUE
TO LIGHT WINDS AND PLENTY OF LOW LEVEL MOISTURE. WEAK COLD FRONT
IN WESTERN NEW ENGLAND WILL REACH COAST AROUND SUNRISE. THIS WILL
PROMOTE RAPID CLEARING AS DRIER AIR WORKS INTO NEW ENGLAND ON W/NW
WINDS.
ISSUE FOR TODAY IS POTENTIAL FOR AFTERNOON CONVECTION. MODELS ALL
WANT TO REDEVELOP SHOWERS/STORMS TO VARIOUS DEGREES. 00Z GFS
DEVELOPS ACTIVITY ALONG SECONDARY FRONT BUT KEEPS MUCH OF IT TO
OUR N...00Z NAM FOCUSES DEVELOPING ALONG SEA BREEZE FRONT IN
EASTERN MA BUT BRINGS MORE ACTIVITY IN THIS EVENING FROM NW...AND
3KM HRRR DEVELOPS SCATTERED SHOWERS ACROSS INTERIOR.
WHILE THERE SEEMS TO BE ENOUGH LOW LEVEL MOISTURE...RIDGING ON
BACKSIDE OF DEPARTING SHORT WAVE AND WARMING ALOFT SHOULD PREVENT
MUCH FROM DEVELOPING THIS AFTERNOON. FORECAST CAPE IS ALSO MEAGER
AS ARE LAPSE RATES. OUR THINKING IS COVERAGE WOULD BE ISOLATED AT
BEST AND PRIMARILY FOCUSED NEAR E MA SEA BREEZE FRONT AS WELL AS
ACROSS FAR INTERIOR /NEAR BERKSHIRES/ DUE TO APPROACH OF SECONDARY
FRONT. WE WILL KEEP POPS BELOW SLIGHT CHANCE BUT HAVE HIGHER /10%/
VALUES IN THESE AREAS.
FORECAST HIGHS ARE A BLEND OF NAM/GFS MOS...RANGING FROM 80S ON
CAPE COD AND ISLANDS TO LOWER AND MID 90S ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
WEAK SURFACE RIDGE MOVES INTO REGION TONIGHT. CLEAR SKIES AND
LIGHT WINDS SHOULD ALLOW FOR PATCHY FOG...ESPECIALLY NEAR S COAST
WHERE FLOW TURNS BACK TO SW.
QUESTION FOR TUE IS WHETHER OR NOT WE SEE RECORD WARMTH. CERTAINLY
HAVE POTENTIAL FOR 100-DEGREE READINGS AWAY FROM S COAST AS
TEMPERATURES ALOFT WARM SIGNIFICANTLY /AROUND +20C AT 850 MB/.
HOWEVER MODELS SHOW POTENTIAL FOR UPSTREAM CONVECTION TONIGHT WHICH
MAY END UP BRINGING CONSIDERABLE MID AND HIGH CLOUDS INTO SOUTHERN
NEW ENGLAND...PUTTING A LID ON HEATING. THIS DIFFERENCE IS REFLECTED
IN WARMER NAM MOS WHICH HAS HIGHS AROUND 100 FOR MUCH OF AREA...WHILE
GFS MOS SEEMS TO HAVE CAUGHT ON TO DEBRIS CLOUDINESS AND HAS HIGHS
CLOSER TO 90.
GIVEN THIS UNCERTAINTY WE WILL SPLIT DIFFERENCE BUT LEAN CLOSER
TO WARMER NAM MOS GIVEN SUCH WARM TEMPERATURES ALOFT...GENERALLY
MID TO UPPER 90S AWAY FROM S COAST. MIXING SHOULD ALLOW DEWPOINTS
TO FALL INTO LOW TO MID 60S TUE AFTERNOON...SO HEAT INDEX VALUES
ARE EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA /100-104
DEGREES/.
RECORD HIGHS FOR TUE ARE LISTED BELOW IN THE CLIMATE SECTION.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...AFTER RECORD OR NEAR RECORD WARMTH ON TUE...A COLD
FRONT WILL MOVE THROUGH THE REGION WED AND WED NIGHT. REFRESHINGLY
COOLER AND DRIER AIR WILL FINISH OUT THE WEEK AS HIGH PRESSURE
MOVES FROM ONTARIO TO NEW ENGLAND. THE DRY WEATHER WILL CONTINUE
THROUGH THIS WEEKEND.
16/00Z GUIDANCE ARE TRENDING MORE AGGRESSIVE IN DEVELOPING A WEAK
LOW PRESSURE ALONG A COLD FRONTAL BOUNDARY SOUTH OF NEW ENGLAND
THURSDAY MORNING. THE TIMING AND STRENGTH OF THIS LOW PRESSURE ARE
STILL QUESTIONABLE BASED ON THE 00Z GEFS MEMBERS. DECIDED TO SLOW
THE EXIT OF PRECIPITATION THURSDAY MORNING SLIGHTLY...BUT STILL
THINK MOST OF THE DAY WILL BE DRY NORTH OF I-90.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...A COLD FRONT WILL BE
MOVING THROUGH THE AREA FROM NW TO SE. MODEL CONSENSUS IS FOR IT
TO HAVE MOVED THROUGH SOUTHERN NH AROUND DAYBREAK WED...WITH A
CHANCE OF A SHOWER OR THUNDERSTORM IN NW MA AND SOUTHERN NH LATE
TUE NIGHT. BY WED AFTERNOON...THE ATMOSPHERE WILL BE MOST UNSTABLE
OVER CT...RI...AND SE MA WHERE WE HAVE FORECAST 40-45 PERCENT
CHANCES OF THUNDERSTORMS. THE MID LEVELS WILL STILL BE QUITE WARM
WHICH WILL CUT DOWN ON THE THREAT OF SEVERE STORMS. HOWEVER...WITH
THE HEAT AND HUMIDITY...A FRONT CAUSING FORCING...AND BULK SHEAR
VALUES OF 30-40 KT...A FEW COULD REACH SEVERE THRESHOLDS. THE
CHANCE WILL CONTINUE WELL INTO WED NIGHT ALONG THE SOUTH COAST.
BUT SKIES WILL BE CLEARING ESPECIALLY FROM THE MASS PIKE
NORTHWARD.
THURSDAY THROUGH SUNDAY...
HIGH PRESSURE BRINGS MOSTLY SUNNY DAYS AND MOSTLY CLEAR NIGHTS
WITH SEASONABLE TEMPERATURES. HIGHS MAINLY IN THE 80S. GREAT
SLEEPING WEATHER WITH NIGHTTIME LOWS MAINLY IN THE 50S TO LOWER
60S.
THE COOLEST OF THE DAYS MAY BE ON FRIDAY...WITH 850 MB
TEMPERATURES DOWN TO +9C TO +10C ON BOTH ECMWF AND GFS. IF IS
POSSIBLE THAT MAX TEMPERATURES REMAIN IN THE MID TO UPPER 70S
ACROSS SOME AREAS.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
SHOULD SEE RAPID IMPROVEMENT OF LOW CIGS/VSBY OVER CAPE AND
ISLANDS AS WELL AS MID CT RIVER VALLEY TO VFR 12Z-15Z. WINDS
NW THIS MORNING BUT AFTERNOON SEA BREEZES LIKELY IN A LARGE SCALE
GRADIENT THAT SLACKENS DURING THE DAY.
LOW POTENTIAL FOR ISOLATED SHOWERS/TSTM AGAIN 18Z-22Z MAINLY IN
EASTERN MA NEAR SEA BREEZE FRONT...BUT CONFIDENCE IS LOW.
VFR TONIGHT AND TUE...ALTHOUGH IFR/LIFR EXPECTED ONCE AGAIN AROUND
CAPE COD AND ISLANDS THIS EVENING INTO TUE MORNING AS FOG/LOW
CLOUDS REFORM WITH CONTINUED SW FLOW.
KBOS TAF...HIGH CONFIDENCE. SEA BREEZE EXPECTED TO INITIATE 16Z-
18Z. ISOLATED SHOWER/TSTM 18Z-22Z NOT OUT OF THE QUESTION BUT NOT
ALL THAT LIKELY.
KBDL TAF...MODERATE TO HIGH CONFIDENCE. MAY SEE PERIOD OF MIFR
VSBYS IN FOG PATCHES LATE TONIGHT.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...
WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR POSSIBLE IN EARLY
MORNING FOG/LOW CLOUDS...THEN VFR/MVFR DURING THE DAY. A FEW TSTMS
MAY BRING BRIEF IFR CONDITIONS IN HEAVY RAIN ESPECIALLY ACROSS
CT/RI/SE MA. CHANCE TSTMS CONTINUING THROUGH WED NIGHT ALONG THE
SOUTH COAST.
THURSDAY AND FRIDAY...HIGH CONFIDENCE VFR.
&&
.MARINE...
HIGH CONFIDENCE THROUGH TUE WITH NO HEADLINES ANTICIPATED. SW FLOW
15KT OR LESS EXPECTED WHICH SHOULD SLOWLY BUILD SEAS ON S COASTAL
WATERS TO 3 OR 4 FT S OF ISLANDS. UNDERCUT WAVEWATCH GUIDANCE
WHICH HAS BEEN RUNNING TOO HIGH IN THIS PATTERN.
MAIN CONCERN IS FOR AREAS OF DENSE FOG TONIGHT INTO TUE MORNING ON
S COASTAL WATERS DUE TO PERSISTENT SW FLOW.
OUTLOOK...WEDNESDAY THROUGH FRIDAY
MODERATE CONFIDENCE DUE TO TIMING OF A COLD FRONT WEDNESDAY. THIS
WILL IMPACT THE STRENGTH OF THE SOUTHWEST FLOW.
SEAS BUILD AGAIN WED AHEAD OF AN APPROACHING COLD FRONT...LOW
RISK OF 5 FOOT SEAS ACROSS THE SOUTHERN OUTER COASTAL WATERS. THIS
FRONT IS EXPECTED TO BRING SCATTERED SHOWERS AND THUNDERSTORMS WED
AND WED NIGHT.
SEAS ARE FORECAST TO REMAIN 3 TO 4 FT AS A RESULT OF NE WINDS THU
AND FRI. THE NE WINDS COULD GUST UP TO 20 KT AT TIMES.
&&
.CLIMATE...
RECORD HIGHS FOR TUE JUL 17:
BOS...98 IN 1999 AND PREVIOUS YEARS
PVD...97 IN 1999 AND PREVIOUS YEARS
BDL...97 IN 1999
ORH...93 IN 1900
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/JWD
NEAR TERM...JWD/THOMPSON
SHORT TERM...JWD
LONG TERM...BELK
AVIATION...BELK/JWD/THOMPSON
MARINE...BELK/JWD
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
422 AM EDT MON JUL 16 2012
.SYNOPSIS...
HOT AND HUMID WEATHER WILL PERSIST THROUGH WEDNESDAY...WITH
TUESDAY BEING THE HOTTEST DAY THIS WEEK. A COLD FRONT WILL BRING A
ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY. SEASONABLE
TEMPERATURES AND LOWER HUMIDITY WILL FOLLOW THURSDAY INTO NEXT
WEEKEND AS A HIGH PRESSURE BUILDS IN FROM CANADA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SMALL LINE OF SHOWERS/STORMS FORMED ALONG S COAST EARLY THIS
MORNING IN AN AREA OF GOOD MOISTURE CONVERGENCE AND LEFTOVER
INSTABILITY. MAIN THREAT WITH THESE STORMS IS BRIEFLY HEAVY
RAIN...AND THEY WILL EXIT COAST BY 4 AM.
OTHERWISE CLOUDS AND PATCHY FOG WILL PREVAIL THROUGH DAYBREAK DUE
TO LIGHT WINDS AND PLENTY OF LOW LEVEL MOISTURE. WEAK COLD FRONT
IN WESTERN NEW ENGLAND WILL REACH COAST AROUND SUNRISE. THIS WILL
PROMOTE RAPID CLEARING AS DRIER AIR WORKS INTO NEW ENGLAND ON W/NW
WINDS.
ISSUE FOR TODAY IS POTENTIAL FOR AFTERNOON CONVECTION. MODELS ALL
WANT TO REDEVELOP SHOWERS/STORMS TO VARIOUS DEGREES. 00Z GFS
DEVELOPS ACTIVITY ALONG SECONDARY FRONT BUT KEEPS MUCH OF IT TO
OUR N...00Z NAM FOCUSES DEVELOPING ALONG SEA BREEZE FRONT IN
EASTERN MA BUT BRINGS MORE ACTIVITY IN THIS EVENING FROM NW...AND
3KM HRRR DEVELOPS SCATTERED SHOWERS ACROSS INTERIOR.
WHILE THERE SEEMS TO BE ENOUGH LOW LEVEL MOISTURE...RIDGING ON
BACKSIDE OF DEPARTING SHORT WAVE AND WARMING ALOFT SHOULD PREVENT
MUCH FROM DEVELOPING THIS AFTERNOON. FORECAST CAPE IS ALSO MEAGER
AS ARE LAPSE RATES. OUR THINKING IS COVERAGE WOULD BE ISOLATED AT
BEST AND PRIMARILY FOCUSED NEAR E MA SEA BREEZE FRONT AS WELL AS
ACROSS FAR INTERIOR /NEAR BERKSHIRES/ DUE TO APPROACH OF SECONDARY
FRONT. WE WILL KEEP POPS BELOW SLIGHT CHANCE BUT HAVE HIGHER /10%/
VALUES IN THESE AREAS.
FORECAST HIGHS ARE A BLEND OF NAM/GFS MOS...RANGING FROM 80S ON
CAPE COD AND ISLANDS TO LOWER AND MID 90S ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
WEAK SURFACE RIDGE MOVES INTO REGION TONIGHT. CLEAR SKIES AND
LIGHT WINDS SHOULD ALLOW FOR PATCHY FOG...ESPECIALLY NEAR S COAST
WHERE FLOW TURNS BACK TO SW.
QUESTION FOR TUE IS WHETHER OR NOT WE SEE RECORD WARMTH. CERTAINLY
HAVE POTENTIAL FOR 100-DEGREE READINGS AWAY FROM S COAST AS
TEMPERATURES ALOFT WARM SIGNIFICANTLY /AROUND +20C AT 850 MB/.
HOWEVER MODELS SHOW POTENTIAL FOR UPSTREAM CONVECTION TONIGHT WHICH
MAY END UP BRINGING CONSIDERABLE MID AND HIGH CLOUDS INTO SOUTHERN
NEW ENGLAND...PUTTING A LID ON HEATING. THIS DIFFERENCE IS REFLECTED
IN WARMER NAM MOS WHICH HAS HIGHS AROUND 100 FOR MUCH OF AREA...WHILE
GFS MOS SEEMS TO HAVE CAUGHT ON TO DEBRIS CLOUDINESS AND HAS HIGHS
CLOSER TO 90.
GIVEN THIS UNCERTAINTY WE WILL SPLIT DIFFERENCE BUT LEAN CLOSER
TO WARMER NAM MOS GIVEN SUCH WARM TEMPERATURES ALOFT...GENERALLY
MID TO UPPER 90S AWAY FROM S COAST. MIXING SHOULD ALLOW DEWPOINTS
TO FALL INTO LOW TO MID 60S TUE AFTERNOON...SO HEAT INDEX VALUES
ARE EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA /100-104
DEGREES/.
RECORD HIGHS FOR TUE ARE LISTED BELOW IN THE CLIMATE SECTION.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...AFTER RECORD OR NEAR RECORD WARMTH ON TUE...A COLD
FRONT WILL MOVE THROUGH THE REGION WED AND WED NIGHT. REFRESHINGLY
COOLER AND DRIER AIR WILL FINISH OUT THE WEEK AS HIGH PRESSURE
MOVES FROM ONTARIO TO NEW ENGLAND. THE DRY WEATHER WILL CONTINUE
THROUGH THIS WEEKEND.
16/00Z GUIDANCE ARE TRENDING MORE AGGRESSIVE IN DEVELOPING A WEAK
LOW PRESSURE ALONG A COLD FRONTAL BOUNDARY SOUTH OF NEW ENGLAND
THURSDAY MORNING. THE TIMING AND STRENGTH OF THIS LOW PRESSURE ARE
STILL QUESTIONABLE BASED ON THE 00Z GEFS MEMBERS. DECIDED TO SLOW
THE EXIT OF PRECIPITATION THURSDAY MORNING SLIGHTLY...BUT STILL
THINK MOST OF THE DAY WILL BE DRY NORTH OF I-90.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...A COLD FRONT WILL BE
MOVING THROUGH THE AREA FROM NW TO SE. MODEL CONSENSUS IS FOR IT
TO HAVE MOVED THROUGH SOUTHERN NH AROUND DAYBREAK WED...WITH A
CHANCE OF A SHOWER OR THUNDERSTORM IN NW MA AND SOUTHERN NH LATE
TUE NIGHT. BY WED AFTERNOON...THE ATMOSPHERE WILL BE MOST UNSTABLE
OVER CT...RI...AND SE MA WHERE WE HAVE FORECAST 40-45 PERCENT
CHANCES OF THUNDERSTORMS. THE MID LEVELS WILL STILL BE QUITE WARM
WHICH WILL CUT DOWN ON THE THREAT OF SEVERE STORMS. HOWEVER...WITH
THE HEAT AND HUMIDITY...A FRONT CAUSING FORCING...AND BULK SHEAR
VALUES OF 30-40 KT...A FEW COULD REACH SEVERE THRESHOLDS. THE
CHANCE WILL CONTINUE WELL INTO WED NIGHT ALONG THE SOUTH COAST.
BUT SKIES WILL BE CLEARING ESPECIALLY FROM THE MASS PIKE
NORTHWARD.
THURSDAY THROUGH SUNDAY...
HIGH PRESSURE BRINGS MOSTLY SUNNY DAYS AND MOSTLY CLEAR NIGHTS
WITH SEASONABLE TEMPERATURES. HIGHS MAINLY IN THE 80S. GREAT
SLEEPING WEATHER WITH NIGHTTIME LOWS MAINLY IN THE 50S TO LOWER
60S.
THE COOLEST OF THE DAYS MAY BE ON FRIDAY...WITH 850 MB
TEMPERATURES DOWN TO +9C TO +10C ON BOTH ECMWF AND GFS. IF IS
POSSIBLE THAT MAX TEMPERATURES REMAIN IN THE MID TO UPPER 70S
ACROSS SOME AREAS.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
SCT TSTMS WILL AFFECT CAPE COD AND ISLANDS THROUGH 08Z WITH
BRIEFLY HEAVY RAIN. OTHERWISE IFR/LIFR WILL PERSIST OVER SE NEW
ENGLAND THROUGH 12Z WITH AREAS OF MVFR CIGS ELSEWHERE. SHOULD SEE
RAPID IMPROVEMENT TO VFR 12Z-15Z AS WINDS SHIFT TO NW.
POTENTIAL FOR ISOLATED SHOWERS/TSTM AGAIN 18Z-22Z MAINLY IN
EASTERN MA NEAR SEA BREEZE FRONT...BUT CONFIDENCE IS LOW.
VFR TONIGHT AND TUE...ALTHOUGH IFR/LIFR EXPECTED ONCE AGAIN AROUND
CAPE COD AND ISLANDS THIS EVENING INTO TUE MORNING AS FOG/LOW
CLOUDS REFORM WITH CONTINUED SW FLOW.
KBOS TAF...HIGH CONFIDENCE. SEA BREEZE EXPECTED 16Z-18Z. MAY SEE
ISOLATED SHOWER/TSTM 18Z-22Z.
KBDL TAF...MODERATE CONFIDENCE. MAY SEE BRIEF PERIOD OF IFR CIGS
BEFORE DAYBREAK.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...
WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR POSSIBLE IN EARLY
MORNING FOG/LOW CLOUDS...THEN VFR/MVFR DURING THE DAY. A FEW TSTMS
MAY BRING BRIEF IFR CONDITIONS IN HEAVY RAIN ESPECIALLY ACROSS
CT/RI/SE MA. CHANCE TSTMS CONTINUING THROUGH WED NIGHT ALONG THE
SOUTH COAST.
THURSDAY AND FRIDAY...HIGH CONFIDENCE VFR.
&&
.MARINE...
HIGH CONFIDENCE THROUGH TUE WITH NO HEADLINES ANTICIPATED. SW FLOW
15KT OR LESS EXPECTED WHICH SHOULD SLOWLY BUILD SEAS ON S COASTAL
WATERS TO 3 OR 4 FT S OF ISLANDS. UNDERCUT WAVEWATCH GUIDANCE
WHICH HAS BEEN RUNNING TOO HIGH IN THIS PATTERN.
MAIN CONCERN IS FOR AREAS OF DENSE FOG TONIGHT INTO TUE MORNING ON
S COASTAL WATERS DUE TO PERSISTENT SW FLOW.
OUTLOOK...WEDNESDAY THROUGH FRIDAY
MODERATE CONFIDENCE DUE TO TIMING OF A COLD FRONT WEDNESDAY. THIS
WILL IMPACT THE STRENGTH OF THE SOUTHWEST FLOW.
SEAS BUILD AGAIN WED AHEAD OF AN APPROACHING COLD FRONT...LOW
RISK OF 5 FOOT SEAS ACROSS THE SOUTHERN OUTER COASTAL WATERS. THIS
FRONT IS EXPECTED TO BRING SCATTERED SHOWERS AND THUNDERSTORMS WED
AND WED NIGHT.
SEAS ARE FORECAST TO REMAIN 3 TO 4 FT AS A RESULT OF NE WINDS THU
AND FRI. THE NE WINDS COULD GUST UP TO 20 KT AT TIMES.
&&
.CLIMATE...
RECORD HIGHS FOR TUE JUL 17:
BOS...98 IN 1999 AND PREVIOUS YEARS
PVD...97 IN 1999 AND PREVIOUS YEARS
BDL...97 IN 1999
ORH...93 IN 1900
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JWD/BELK
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...BELK
AVIATION...JWD/BELK
MARINE...JWD/BELK
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
255 AM EDT MON JUL 16 2012
.SYNOPSIS...
HOT AND HUMID WEATHER WILL PERSIST THROUGH WEDNESDAY...WITH
TUESDAY BEING THE HOTTEST DAY OF THE WEEK. A COLD FRONT WILL
LIKELY BRING A ROUND OF SHOWERS AND THUNDERSTORMS WEDNESDAY.
SEASONABLE TEMPERATURES AND LOWER HUMIDITY WILL FOLLOW THURSDAY
INTO NEXT WEEKEND AS HIGH PRESSURE BUILDS IN FROM CANADA.
&&
.NEAR TERM /THROUGH TODAY/...
SMALL LINE OF SHOWERS/STORMS FORMED ALONG S COAST EARLY THIS
MORNING IN AN AREA OF GOOD MOISTURE CONVERGENCE AND LEFTOVER
INSTABILITY. MAIN THREAT WITH THESE STORMS IS BRIEFLY HEAVY
RAIN...AND THEY WILL EXIT COAST BY 4 AM.
OTHERWISE CLOUDS AND PATCHY FOG WILL PREVAIL THROUGH DAYBREAK DUE
TO LIGHT WINDS AND PLENTY OF LOW LEVEL MOISTURE. WEAK COLD FRONT
IN WESTERN NEW ENGLAND WILL REACH COAST AROUND SUNRISE. THIS WILL
PROMOTE RAPID CLEARING AS DRIER AIR WORKS INTO NEW ENGLAND ON W/NW
WINDS.
ISSUE FOR TODAY IS POTENTIAL FOR AFTERNOON CONVECTION. MODELS ALL
WANT TO REDEVELOP SHOWERS/STORMS TO VARIOUS DEGREES. 00Z GFS
DEVELOPS ACTIVITY ALONG SECONDARY FRONT BUT KEEPS MUCH OF IT TO
OUR N...00Z NAM FOCUSES DEVELOPING ALONG SEA BREEZE FRONT IN
EASTERN MA BUT BRINGS MORE ACTIVITY IN THIS EVENING FROM NW...AND
3KM HRRR DEVELOPS SCATTERED SHOWERS ACROSS INTERIOR.
WHILE THERE SEEMS TO BE ENOUGH LOW LEVEL MOISTURE...RIDGING ON
BACKSIDE OF DEPARTING SHORT WAVE AND WARMING ALOFT SHOULD PREVENT
MUCH FROM DEVELOPING THIS AFTERNOON. FORECAST CAPE IS ALSO MEAGER
AS ARE LAPSE RATES. OUR THINKING IS COVERAGE WOULD BE ISOLATED AT
BEST AND PRIMARILY FOCUSED NEAR E MA SEA BREEZE FRONT AS WELL AS
ACROSS FAR INTERIOR /NEAR BERKSHIRES/ DUE TO APPROACH OF SECONDARY
FRONT. WE WILL KEEP POPS BELOW SLIGHT CHANCE BUT HAVE HIGHER /10%/
VALUES IN THESE AREAS.
FORECAST HIGHS ARE A BLEND OF NAM/GFS MOS...RANGING FROM 80S ON
CAPE COD AND ISLANDS TO LOWER AND MID 90S ELSEWHERE.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
WEAK SURFACE RIDGE MOVES INTO REGION TONIGHT. CLEAR SKIES AND
LIGHT WINDS SHOULD ALLOW FOR PATCHY FOG...ESPECIALLY NEAR S COAST
WHERE FLOW TURNS BACK TO SW.
QUESTION FOR TUE IS WHETHER OR NOT WE SEE RECORD WARMTH. CERTAINLY
HAVE POTENTIAL FOR 100-DEGREE READINGS AWAY FROM S COAST AS
TEMPERATURES ALOFT WARM SIGNIFICANTLY /AROUND +20C AT 850 MB/.
HOWEVER MODELS SHOW POTENTIAL FOR UPSTREAM CONVECTION TONIGHT WHICH
MAY END UP BRINGING CONSIDERABLE MID AND HIGH CLOUDS INTO SOUTHERN
NEW ENGLAND...PUTTING A LID ON HEATING. THIS DIFFERENCE IS REFLECTED
IN WARMER NAM MOS WHICH HAS HIGHS AROUND 100 FOR MUCH OF AREA...WHILE
GFS MOS SEEMS TO HAVE CAUGHT ON TO DEBRIS CLOUDINESS AND HAS HIGHS
CLOSER TO 90.
GIVEN THIS UNCERTAINTY WE WILL SPLIT DIFFERENCE BUT LEAN CLOSER
TO WARMER NAM MOS GIVEN SUCH WARM TEMPERATURES ALOFT...GENERALLY
MID TO UPPER 90S AWAY FROM S COAST. MIXING SHOULD ALLOW DEWPOINTS
TO FALL INTO LOW TO MID 60S TUE AFTERNOON...SO HEAT INDEX VALUES
ARE EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA /100-104
DEGREES/.
RECORD HIGHS FOR TUE ARE LISTED BELOW IN THE CLIMATE SECTION.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...AFTER RECORD OR NEAR RECORD WARMTH ON TUE... A COLD
FRONT WILL MOVE THROUGH THE REGION WED AND WED NIGHT. REFRESHINGLY
COOLER AND DRIER AIR WILL FINISH OUT THE WEEK AS HIGH PRESSURE
MOVES FROM ONTARIO TO NEW ENGLAND. THE DRY WEATHER WILL CONTINUE
THROUGH THE WEEKEND.
TUESDAY...
WESTERLY DOWNSLOPE FLOW...COMBINED WITH 925 MB TEMPS WARMING TO
BETWEEN +25C AND +28C... WILL LEAD TO RECORD OR NEAR RECORD HIGH
TEMPERATURES /SEE CLIMATE SECTION BELOW/. MADE NO CHANGES TO
CURRENT MAX TEMP FORECAST SINCE IT IS A COMPROMISE BETWEEN THE HOT
NAM WHICH GIVES 101 TO BDL...AND THE COOLER GFS WHICH HAS 94 FOR
BDL. IF A SEA BREEZE FORMS AT BOSTON...IT WOULD LIKELY BE BRIEF
AND IN THE LATE MORNING/VERY EARLY AFTERNOON. 925 MB WINDS ARE 10
KT ON GFS AT 18Z BUT 15 KT ON NAM. THEY INCREASE TO 20 AND 25 KT
RESPECTIVELY BY 00Z WED...WHICH SHOULD STOP ANY SEA BREEZES.
700 MB TEMPS WARM TO +10C TO +12C WHICH SHOULD EFFECTIVELY PUT A
LID ON ANY CONVECTION...SO HAVE A DRY DAY FORECAST.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
A COLD FRONT WILL BE MOVING THROUGH THE AREA FROM NW TO SE.
MODEL CONSENSUS IS FOR IT TO HAVE MOVED THROUGH SOUTHERN NH AROUND
DAYBREAK WED...WITH A CHANCE OF A SHOWER OR THUNDERSTORM IN NW MA
AND SOUTHERN NH LATE TUE NIGHT. BY WED AFTERNOON...THE ATMOSPHERE
WILL BE MOST UNSTABLE OVER CT...RI...AND SE MA WHERE WE HAVE
FORECAST 40-45 PERCENT CHANCES OF THUNDERSTORMS. THE MID LEVELS
WILL STILL BE QUITE WARM WHICH WILL CUT DOWN ON THE THREAT OF
SEVERE STORMS. HOWEVER...WITH THE HEAT AND HUMIDITY...A FRONT
CAUSING FORCING...AND BULK SHEAR VALUES OF 30-40 KT...A FEW COULD
REACH SEVERE THRESHOLDS. THE CHANCE WILL CONTINUE WELL INTO WED
NIGHT ALONG THE SOUTH COAST. BUT SKIES WILL BE CLEARING ESPECIALLY
FROM THE MASS PIKE NORTHWARD.
THURSDAY THROUGH SUNDAY...
HIGH PRESSURE BRINGS MOSTLY SUNNY DAYS AND MOSTLY CLEAR NIGHTS
WITH SEASONABLE TEMPERATURES. HIGHS MAINLY IN THE 80S. GREAT
SLEEPING WEATHER WITH NIGHTTIME LOWS MAINLY IN THE 50S TO LOWER
60S.
THE COOLEST OF THE DAYS MAY BE ON FRIDAY...WITH 850 MB
TEMPERATURES DOWN TO +9C TO +10C ON BOTH ECMWF AND GFS. POSSIBLE
THAT MAX TEMPS REMAIN IN THE MID TO UPPER 70S IN SOME AREAS.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
SCT TSTMS WILL AFFECT CAPE COD AND ISLANDS THROUGH 08Z WITH
BRIEFLY HEAVY RAIN. OTHERWISE IFR/LIFR WILL PERSIST OVER SE NEW
ENGLAND THROUGH 12Z WITH AREAS OF MVFR CIGS ELSEWHERE. SHOULD SEE
RAPID IMPROVEMENT TO VFR 12Z-15Z AS WINDS SHIFT TO NW.
POTENTIAL FOR ISOLATED SHOWERS/TSTM AGAIN 18Z-22Z MAINLY IN
EASTERN MA NEAR SEA BREEZE FRONT...BUT CONFIDENCE IS LOW.
VFR TONIGHT AND TUE...ALTHOUGH IFR/LIFR EXPECTED ONCE AGAIN AROUND
CAPE COD AND ISLANDS THIS EVENING INTO TUE MORNING AS FOG/LOW
CLOUDS REFORM WITH CONTINUED SW FLOW.
KBOS TAF...HIGH CONFIDENCE. SEA BREEZE EXPECTED 16Z-18Z. MAY SEE
ISOLATED SHOWER/TSTM 18Z-22Z.
KBDL TAF...MODERATE CONFIDENCE. MAY SEE BRIEF PERIOD OF IFR CIGS
BEFORE DAYBREAK.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...
WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR POSSIBLE IN EARLY
MORNING FOG/LOW CLOUDS...THEN VFR/MVFR DURING THE DAY. A FEW TSTMS
MAY BRING BRIEF IFR CONDITIONS IN HEAVY RAIN ESPECIALLY IN
CT/RI/SE MA. CHANCE TSTMS CONTINUING THROUGH WED NIGHT ALONG THE
SOUTH COAST.
THURSDAY AND FRIDAY...HIGH CONFIDENCE VFR.
&&
.MARINE...
HIGH CONFIDENCE THROUGH TUE WITH NO HEADLINES ANTICIPATED. SW FLOW
15KT OR LESS EXPECTED WHICH SHOULD SLOWLY BUILD SEAS ON S COASTAL
WATERS TO 3 OR 4 FT S OF ISLANDS. UNDERCUT WAVEWATCH GUIDANCE
WHICH HAS BEEN RUNNING TOO HIGH IN THIS PATTERN.
MAIN CONCERN IS FOR AREAS OF DENSE FOG TONIGHT INTO TUE MORNING ON
S COASTAL WATERS DUE TO PERSISTENT SW FLOW.
OUTLOOK...WEDNESDAY THROUGH FRIDAY
MODERATE CONFIDENCE DUE TO TIMING OF A COLD FRONT WEDNESDAY. THIS
WILL IMPACT THE STRENGTH OF THE SOUTHWEST FLOW.
SEAS BUILD AGAIN WED AHEAD OF AN APPROACHING COLD FRONT...LOW
RISK OF 5 FOOT SEAS ACROSS THE SOUTHERN OUTER COASTAL WATERS. THIS
FRONT IS EXPECTED TO BRING SCATTERED SHOWERS AND THUNDERSTORMS WED
AND WED NIGHT.
SEAS ARE FORECAST TO REMAIN 3 TO 4 FT AS A RESULT OF NE WINDS THU
AND FRI. THE NE WINDS COULD GUST TO 20 KT AT TIMES.
&&
.CLIMATE...
RECORD HIGHS FOR TUE JUL 17:
BOS...98 IN 1999 AND PREVIOUS YEARS
PVD...97 IN 1999 AND PREVIOUS YEARS
BDL...97 IN 1999
ORH...93 IN 1900
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...GAF
AVIATION...BELK/JWD
MARINE...BELK/JWD
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
330 AM EDT MON JUL 16 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A COMPLEX UPPER LEVEL
PATTERN IN THE VICINITY OF THE LOCAL AREA. WE FIND A DOUBLE TUTT
(TROPICAL UPPER TROPOSPHERIC TROUGH) LOW FEATURE WITH ONE LOW CENTER
JUST OFF THE JACKSONVILLE COAST...AND ANOTHER MOVING WESTWARD OVER
THE SE GULF OF MEXICO. THE TUTT CELL OFF THE JACKSONVILLE COAST IS
PROGGED BY ALMOST ALL GUIDANCE TO BECOME THE DOMINANT UPPER FEATURE
TODAY AS IT MOVES SLOWLY WESTWARD OVER THE NORTHERN FLORIDA
PENINSULA. THE OTHER UPPER LOW WILL CONTINUE TO HELP ENHANCE THE
CONVECTION SEEN ACROSS THE SOUTHERN COASTAL WATERS FOR THE REMAINDER
OF THE NIGHT...BUT SHOULD BE SLOWLY LOSING INFLUENCE THEREAFTER.
DEEP COLUMN MOISTURE WITH PW VALUES OVER 2" ARE SEEN OVER CENTRAL
AND SOUTHERN FL. SOME WEAK DRYING IS EVIDENT IN SATELLITE IMAGERY
PUSHING SOUTHWARD INTO NORTH FLORIDA AROUND THE WESTERN PERIPHERY OF
THE TUTT CIRCULATION. THIS TREND IS LIKELY TO HELP PROVIDE MORE SUN
OVER THE NORTHERN ZONES THIS MORNING. OF NOTE...DETECTING SOME
LIGHTNING FLASHES UNDERNEATH THE CORE OF THE TUTT CELL OFF
JACKSONVILLE EARLY THIS MORNING...INDICATIVE OF SOME RATHER COLD
MID-LEVEL TEMPS ASSOCIATED WITH THIS FEATURE. THIS COLDER AIRMASS
MAY BECOME A PLAYER OVER OUR NORTHERN COUNTIES LATE THIS
AFTERNOON/EVENING IN TERMS OF ENHANCING CONVECTIVE UPDRAFTS.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS IS ACROSS THE SOUTH-CENTRAL
FL PENINSULA EARLY THIS MORNING...HOWEVER THE DEGREE OF CONVECTION
ALONG THE SE FL COAST AND IN THE SE GULF ARE RESULTING IN A RATHER
MESSY PRESSURE ANALYSIS.
&&
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
TODAY...TUTT CELL CENTER WILL SLOWLY PUSH WEST/WSW FROM OFF THE
JACKSONVILLE COAST THIS MORNING TO A POSITION OVER NORTHERN FLORIDA
THIS EVENING. THE COMPLEX PATTERN WILL MAKE PUTTING SPATIAL AND
TEMPORAL DETAIL INTO THE CONVECTIVE FORECAST DIFFICULT. LETS JUST
SAY THAT RAIN CHANCES WILL REMAIN HIGH. THESE RAIN CHANCES WILL BE
ASSOCIATED WITH THE HIGH COLUMN MOISTURE OVER THE SOUTHERN
ZONES...AND MORE TIED TO THE SYNOPTIC SUPPORT OF THE APPROACHING
TUTT OVER THE NORTHERN ZONES. AS MENTIONED IN THE SYNOPSIS...AIRMASS
CHANGE ROTATING AROUND THE TUTT WILL ACTUALLY ALLOW FOR QUITE A BIT
OF SUNSHINE OVER THE NORTHERN ZONES THIS MORNING...WITH CONVECTIVE
CLOUDS FILLING IN LATER. THE SOUTHERN HALF OF THE AREA LOOKS TO SEE
MORE IN THE WAY OF CLOUDS THROUGH THE DAY. THE MOIST COLUMN...WEAK
LAPSE RATES SHOULD LEAD TO QUITE A BIT OF SHOWER/STORMS COVERAGE
SOUTH OF TAMPA BAY...BUT WITH LESS VIGOROUS CONVECTION AND LESS
OVERALL LIGHTNING. OVER THE NORTHERN ZONES...THE APPROACH OF THE
TUTT CENTER WILL DELIVER MID-LEVEL CAA FROM THE NORTHEAST. IN
FACT...H5 TEMPS OF -9C TO -10C ARE PROGGED TO ARRIVE THIS EVENING.
THESE TEMPS ARE ON THE COLD SIDE FOR JULY...AND MAY ENHANCE THE
POTENTIAL FOR A FEW STRONG/SEVERE STORMS LATE THIS AFTERNOON AND
INTO THE EVENING HOURS. SOMEWHAT UNUSUAL FOR LATE JULY...BUT WE MAY
DEVELOP A HAIL THREAT WITH THE STRONGER STORMS IF THESE PROGGED
TEMPERATURES/LAPSE RATES VERIFY.
TONIGHT...DIURNAL CONVECTION WILL SLOWLY FADE...ALTHOUGH A FEW
STRONGER STORMS OVER THE NORTHERN ZONES WILL CONTINUE TO BE A THREAT
FOR A FEW HOURS AFTER SUNSET. THE SYNOPTIC SUPPORT FROM THE UPPER
LOW AND A FAVORED SW LOW LEVEL FLOW SHOULD RESULT IN NOCTURNAL
OFFSHORE CONVECTION PUSHING BACK TOWARD THE COASTAL ZONES DURING THE
LATE NIGHT HOURS. WILL KEEP CHANCE POPS IN THE GRIDS ALONG THE COAST.
TUESDAY LOOKS TO BE A TRANSITION DAY BETWEEN MONDAY`S DISTURBED
PATTERN AND ONE FEATURING STACKED RIDGING FOR THE MIDDLE AND LATER
PART OF THE WEEK. UPPER LOW BEGINS TO LIFT OUT TO THE NORTH ALLOWING
A MORE DEFINED SUBTROPICAL RIDGE TO REBUILD OVER THE SOUTHERN FL
PENINSULA. SCATTERED SHOWERS SHOULD CONTINUE TO MOVE ASHORE DURING
THE MORNING HOURS WITHIN THE SW FLOW...HOWEVER AS THE SEA-BREEZE
BECOMES ESTABLISHED AND PUSHES INLAND...THE GREATER THREAT FOR
SHOWERS/STORMS IS ANTICIPATED TO ALSO TRANSLATE INLAND AWAY FROM THE
COAST.
WEDNESDAY...H5 HEIGHT WILL BUILD THROUGH THE DAY AS UPPER RIDGING
EXPANDS WESTWARD OVER THE PENINSULA/EASTERN GULF. AT THE SAME
TIME...THE SUBTROPICAL SURFACE RIDGE WILL BECOME WELL ESTABLISHED
WITH AN AXIS TO THE SOUTH OF TAMPA BAY. THIS PATTERN WILL LEAD TO A
FAIRLY TYPICAL SUMMER DAY FOR OUR AREA. SW FLOW AROUND THE RIDGE
AXIS WILL LEAD TO A FEW SCATTERED SHOWERS/STORMS DURING THE
MORNING/EARLY AFTERNOON CLOSE TO THE COAST...WITH MAJORITY OF THE
ACTIVITY PUSHING INLAND BY THE LATER PORTION OF THE DAY. DUE TO THE
GREATER SUPPRESSION UNDERNEATH THE RIDGE...WILL ALSO BE LOOKING FOR
TEMPERATURES TO BEGIN CREEPING BACK UP. CURRENT GRIDS SHOWING A
RETURN TO MID 90S FOR INLAND AREAS ALONG/SOUTH OF THE I-4 CORRIDOR.
&&
.LONG TERM (THURSDAY THROUGH NEXT MONDAY)...
STRONG SUBTROPICAL RIDGING OVER THE ATLANTIC WILL EXTEND WESTWARD
ACROSS CENTRAL FLORIDA THROUGH THE PERIOD. IN GENERAL...THIS WILL
RESULT IN ABOVE NORMAL TEMPERATURES EACH AFTERNOON WITH BELOW NORMAL
RAIN CHANCES. 00Z GFS SHOWS A DRY SLOT OF AIR MOVING OVER THE REGION
ON FRIDAY WHICH WILL DECREASE OUR RAIN CHANCES TO LESS THAN 30
PERCENT ACROSS THE ENTIRE AREA.
LATE FRIDAY INTO SATURDAY...A DEEPENING EASTERN U.S. TROUGH WILL
CREATE A WEAKNESS IN THE SUBTROPICAL RIDGE BUT THE MOISTURE IS SLOW
TO RETURN FROM THE SOUTH. BY LATER IN THE DAY ON SATURDAY AND
ESPECIALLY ON SUNDAY...PRECIPITABLE WATERS RETURN TO NEAR TWO
INCHES. MEX GUIDANCE STILL SHOWS BELOW NORMAL RAIN CHANCES...MOST
LIKELY DUE TO THE INFLUENCE OF THE UPPER-LEVEL RIDGE. I WILL FOLLOW
GUIDANCE FOR NOW SINCE WE ARE TALKING ABOUT DAYS 6 AND 7...BUT WOULD
NOT BE SURPRISED IF WE END UP NEEDING TO RAISE WEEKEND RAIN CHANCES
IN FUTURE FORECASTS.
&&
.AVIATION...
EXPECT THUNDERSTORMS TO DEVELOP DURING THE LATE MORNING OR EARLY
AFTERNOON HOURS AND MOVE SOUTH OR SOUTHEAST ACROSS THE REGION. THERE
IS A GOOD CHANCE THAT ALL OF THE TERMINALS WILL SEE A PERIOD OF MVFR
OR IFR CONDITIONS IN THUNDERSTORMS THIS AFTERNOON...BUT CONFIDENCE
IN TIMING TOO LOW TO INCLUDE TEMPO GROUPS AT THIS TIME.
&&
.MARINE...
LIGHT AND VARIABLE FLOW EXPECTED TODAY WITH SOME ENHANCEMENT ONSHORE
NEAR THE COAST DURING THE AFTERNOON HOURS. THE SUBTROPICAL RIDGE
AXIS WILL THEN BECOME WELL ESTABLISHED DURING THE MIDDLE AND LATER
PORTION OF THE WEEK...WITH AN AXIS NEAR OR JUST SOUTH OF TAMPA BAY.
THIS RIDGE POSITION WILL KEEP WINDS AND SEAS LOW THROUGH THE WEEK.
NEARSHORE FLOW WILL GENERALLY BE OFFSHORE DURING THE LATE
NIGHT/MORNING HOURS AND THEN SWITCH ONSHORE DURING THE AFTERNOON AND
EVENING HOURS WITH SEA-BREEZE DEVELOPMENT.
&&
.FIRE WEATHER..
NO SIGNIFICANT FIRE WEATHER CONCERNS ANTICIPATED THROUGH THE MIDDLE
OF THE WEEK AS RELATIVE HUMIDITY LEVELS REMAIN ABOVE CRITICAL VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 75 89 76 / 60 40 40 20
FMY 89 74 91 75 / 60 30 40 20
GIF 91 74 91 75 / 70 40 60 30
SRQ 88 76 89 76 / 60 40 40 20
BKV 90 71 91 71 / 60 40 50 30
SPG 88 77 89 78 / 60 40 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WEATHER...MROCZKA
AVIATION/LONG TERM...JILLSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1035 PM EDT TUE JUL 17 2012
.UPDATE...
HAVE LEFT SLIGHT CHANCE POPS ACROSS THE CWA FOR THE REMAINDER OF THE
NIGHT...EXCEPT CHANCE FOR AREAS NORTH OF ATLANTA TO ATHENS. SOME
CONVECTION DEVELOPING NEAR CHATTANOOGA AND DRIFTING SOUTH. RAIN
COOLED AIR HAS REACHED THE FORECAST MIN TEMPERATURES IN A FEW AREAS.
SO HAVE LOWERED THE OVERNIGHT MINS A BIT. OTHERWISE NO CHANGES.
41
.PREVIOUS...
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
PRIMARY CONCERN IS COVERAGE OF TSRA THIS AFTERNOON AND EVOLUTION
THIS EVENING. SO FAR TODAY...CONVECTION CLOSELY FOLLOWING MORNING
HRRR RUNS WITH ONE COMPLEX MOVING THROUGH EAST AND NOW SOUTHERN
PARTS OF ATL METRO. OTHER SCT STORMS ACROSS WESTCENTRAL AND FAR NE
GA. HRRR DID PROG ABUNDANT CONVECTION OVER NW GA TO NRN AL ALONG
CUMBERLAND PLATEAU AFTER 21Z WHICH IS NOT PANNING OUT SO FAR.
EXPECT TSRA TO CONTINUE TO PUSH SLOWLY SSW. HEAVY RAIN HAS BEEN
OCCURRING BUT FORTUNATELY...NO ONE AREA IS APPROACHING FFG.
EXPECTION TSRA TO WEAKEN SOME AFTER 6PM AND DISSIPATE BY 9PM.
UPPER LOW OVER NRN FL CONTINUES TO BE PRIMARY FEATURE. THIS LOW
PROGGED BY ALL MODELS TO DRIFT NORTH TONIGHT AND TOMORROW AS IT
GETS PICKED UP BY WEAK WESTERLIES WHICH DRIFT INTO THE MID
ATLANTIC WED. IMPACT FOR CWA IS HIGH MEAN RH AND CONTINUED DIURNAL
CONVECTION WITH NO PREFERENCE FOR ANY ONE LOCATION. CHC POPS
APPEAR MOST APPROPRIATE. ISOLD SVR STORMS AGAIN LIKELY. IF WE GET
MORE CLOUDS OR MORNING PRECIP WED...WILL SEE LESS THAN TODAY.
HAVE TWEAKED MAX TEMP GUIDANCE UP A LITTLE BASED ON RECENT TRENDS
AND MORE ISOLATED AFTERNOON CONVECTION THAN MODELS DEPICTING.
GUIDANCE BLEND WORKING WELL WITH SLIGHT UPWARD ADJUSTMENT FOR MIN
TEMPS.
SNELSON
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MINOR DISCREPANCIES IN MODEL SOLUTIONS FOR THE LONG TERM BUT OVERALL
DECENT GENERAL CONSENSUS. GFS HAS GREATER AMOUNTS OF MOISTURE THAN
THE ECMWF FOR MUCH OF THE FORECAST PERIOD AND SLIGHT DIFFERENCES IN
LOCATION OF THE SFC FRONT PROGGED TO DIP SOUTHWARD INTO THE AREA FOR
THE WEEKEND. DUE TO UNCERTAINTY WITH LOCATION OF THIS BOUNDARY THIS
LATE IN THE FORECAST PERIOD... HAVE MAINTAINED CURRENT FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
BAKER
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
&&
AVIATION...
00Z UPDATE...
MAY BE SOME LINGERING THUNDER FOR MCN AND CSG FOR ANOTHER COUPLE OF
HOURS...OTHERWISE CONVECTION APPEARS TO BE OVER FOR THE NIGHT.
SHOULD BE VFR CEILINGS OVERNIGHT BUT MAY HAVE SOME SCATTERED MVFR
STRATUS 10Z TO 13Z DUE TO AVAILABLE LOW LEVEL MOISTURE. VISIBILITY
UNRESTRICTED EXCEP LOCAL IFR IN FOG AFTER 06Z. WINDS VARIABLE 5KT OR
LESS OVERNIGHT BECOMING WEST TO NORTHWEST 5 TO 10KT AFTER 14Z
WEDNESDAY. SIMILAR PATTERN TOMORROW WITH MAINLY AFTERNOON TSRA.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE ON FORMATION OF MORNING STRATUS.
MEDIUMM TO HIGH ON ALL OTHER ELEMENTS
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 95 71 94 / 20 40 30 40
ATLANTA 74 92 73 91 / 20 50 30 40
BLAIRSVILLE 67 88 68 87 / 20 40 30 50
CARTERSVILLE 69 93 70 92 / 20 50 30 50
COLUMBUS 75 94 73 92 / 30 50 40 50
GAINESVILLE 72 93 72 91 / 20 40 30 50
MACON 73 94 72 93 / 30 50 30 40
ROME 70 94 71 92 / 20 50 30 50
PEACHTREE CITY 70 93 70 91 / 20 50 40 40
VIDALIA 74 94 74 95 / 30 50 40 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...41
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
745 PM EDT TUE JUL 17 2012
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
PRIMARY CONCERN IS COVERAGE OF TSRA THIS AFTERNOON AND EVOLUTION
THIS EVENING. SO FAR TODAY...CONVECTION CLOSELY FOLLOWING MORNING
HRRR RUNS WITH ONE COMPLEX MOVING THROUGH EAST AND NOW SOUTHERN
PARTS OF ATL METRO. OTHER SCT STORMS ACROSS WESTCENTRAL AND FAR NE
GA. HRRR DID PROG ABUNDANT CONVECTION OVER NW GA TO NRN AL ALONG
CUMBERLAND PLATEAU AFTER 21Z WHICH IS NOT PANNING OUT SO FAR.
EXPECT TSRA TO CONTINUE TO PUSH SLOWLY SSW. HEAVY RAIN HAS BEEN
OCCURRING BUT FORTUNATELY...NO ONE AREA IS APPROACHING FFG.
EXPECTION TSRA TO WEAKEN SOME AFTER 6PM AND DISSIPATE BY 9PM.
UPPER LOW OVER NRN FL CONTINUES TO BE PRIMARY FEATURE. THIS LOW
PROGGED BY ALL MODELS TO DRIFT NORTH TONIGHT AND TOMORROW AS IT
GETS PICKED UP BY WEAK WESTERLIES WHICH DRIFT INTO THE MID
ATLANTIC WED. IMPACT FOR CWA IS HIGH MEAN RH AND CONTINUED DIURNAL
CONVECTION WITH NO PREFERENCE FOR ANY ONE LOCATION. CHC POPS
APPEAR MOST APPROPRIATE. ISOLD SVR STORMS AGAIN LIKELY. IF WE GET
MORE CLOUDS OR MORNING PRECIP WED...WILL SEE LESS THAN TODAY.
HAVE TWEAKED MAX TEMP GUIDANCE UP A LITTLE BASED ON RECENT TRENDS
AND MORE ISOLATED AFTERNOON CONVECTION THAN MODELS DEPICTING.
GUIDANCE BLEND WORKING WELL WITH SLIGHT UPWARD ADJUSTMENT FOR MIN
TEMPS.
SNELSON
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MINOR DISCREPANCIES IN MODEL SOLUTIONS FOR THE LONG TERM BUT OVERALL
DECENT GENERAL CONSENSUS. GFS HAS GREATER AMOUNTS OF MOISTURE THAN
THE ECMWF FOR MUCH OF THE FORECAST PERIOD AND SLIGHT DIFFERENCES IN
LOCATION OF THE SFC FRONT PROGGED TO DIP SOUTHWARD INTO THE AREA FOR
THE WEEKEND. DUE TO UNCERTAINTY WITH LOCATION OF THIS BOUNDARY THIS
LATE IN THE FORECAST PERIOD... HAVE MAINTAINED CURRENT FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
BAKER
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
&&
AVIATION...
00Z UPDATE...
MAY BE SOME LINGERING THUNDER FOR MCN AND CSG FOR ANOTHER COUPLE OF
HOURS...OTHERWISE CONVECTION APPEARS TO BE OVER FOR THE NIGHT.
SHOULD BE VFR CEILINGS OVERNIGHT BUT MAY HAVE SOME SCATTERED MVFR
STRATUS 10Z TO 13Z DUE TO AVAILABLE LOW LEVEL MOISTURE. VISIBILITY
UNRESTRICTED EXCEP LOCAL IFR IN FOG AFTER 06Z. WINDS VARIABLE 5KT OR
LESS OVERNIGHT BECOMING WEST TO NORTHWEST 5 TO 10KT AFTER 14Z
WEDNESDAY. SIMILAR PATTERN TOMORROW WITH MAINLY AFTERNOON TSRA.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE ON FORMATION OF MORNING STRATUS.
MEDIUMM TO HIGH ON ALL OTHER ELEMENTS
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 95 71 94 / 20 40 30 40
ATLANTA 74 92 73 91 / 20 50 30 40
BLAIRSVILLE 67 88 68 87 / 20 40 30 50
CARTERSVILLE 69 93 70 92 / 20 50 30 50
COLUMBUS 75 94 73 92 / 30 50 40 50
GAINESVILLE 72 93 72 91 / 20 40 30 50
MACON 73 94 72 93 / 30 50 30 40
ROME 70 94 71 92 / 20 50 30 50
PEACHTREE CITY 70 93 70 91 / 20 50 40 40
VIDALIA 74 94 74 95 / 30 50 40 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...41
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1255 PM CDT MON JUL 16 2012
.DISCUSSION...
ISSUED 1045 AM CDT MON JUL 16 2012
FORECAST GENERALLY ON TRACK TODAY AND THE ONLY UPDATE THAT
WE MAY DO IS TO ADD SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
IN SOUTHEAST IL (SE OF I-70) THIS AFTERNOON WHERE SCATTERED
CUMULUS CLOUDS HAVE DEVELOPED BY LATE MORNING. NAM MODEL KEEPS IT
DRY OVER CENTRAL AND SE IL WHILE HRRR MODEL DEVELOPS SCATTERED
CONVECTION ACROSS CWA THIS AFTERNOON THOUGH THINK THIS IS WAY
OVERDONE ESPECIALLY OVER CENTRAL IL WHERE ITS STILL SUNNY. SREF
MODELS HAS SOME QPF OVER SOUTHERN AREAS THIS AFTERNOON. HOT AND
HUMID TODAY WITH HIGHS IN THE MID TO UPPER 90S. THIS HEAT COMBINED
WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S WILL GIVE HEAT
INDICES AROUND 100F THIS AFTERNOON. EVEN HOTTER TUESDAY WITH HIGHS
NEAR 100F AND HEAT INDICES PEAKING FROM 100-105F TUESDAY AFTERNOON.
HUETTL
&&
.AVIATION...
ISSUED 1250 PM CDT MON JUL 16 2012
DIURNALLY DRIVEN SCATTERED TO OCCASIONALLY BROKEN CUMULUS CLOUDS
OF 4-6K FT EXPECTED THIS AFTERNOON (AS LOW WAS 3K FT AT BMI EARLY
AFTERNOON) TO DISSIPATE AT SUNSET (01-02Z). ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON SHOULD STAY SE OF THE CENTRAL IL TAF
SITES WITH POPS LESS THAN 20% OVER CENTRAL IL. SCATTERED CUMULUS
CLOUDS 3-5K FT TO REDEVELOP AFTER 15Z/10 AM TUE ACROSS CENTRAL IL
IN HUMID AIR MASS WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S.
SW WINDS NEAR 10 KTS THIS AFTERNOON TO LIGHTEN UP A FEW KNOTS BY
SUNSET AND THEN BACK TO NEAR 10 KTS BY 15Z/10 AM TUE MORNING. IL
WILL STAY SANDWICHED IN TROPICAL AIR MASS BETWEEN WEAK HIGH
PRESSURE OF 1019 MB OVER THE TN VALLEY...WHILE 1003 MB LOW
PRESSURE ALONG THE MN/CANADA BORDER WITH A FRONTAL BOUNDARY FROM
THE NORTHERN GREAT LAKES INTO CENTRAL SD WHERE THERE IS A 1005 MB
LOW PRESSURE.
KH
&&
.PREV DISCUSSION...
ISSUED 248 AM CDT MON JUL 16 2012
EVENING UPPER AIR ANALYSIS SHOWS LARGE RIDGE OF HIGH PRESSURE
DOMINATING MUCH OF THE CONUS...WITH TROUGHING EVIDENT WEST OF THE
ROCKIES AND ACROSS NEW ENGLAND. 850MB TEMPS BENEATH THE RIDGE AXIS
WERE AT OR ABOVE 30C ACROSS THE WESTERN DAKOTAS INTO
NEBRASKA...RESULTING IN HIGH TEMPS WELL ABOVE 100 DEGREES
YESTERDAY AFTERNOON.
SHORT TERM...TODAY THROUGH WEDNESDAY
HEART OF HOT AIRMASS CENTERED OVER THE PLAINS WILL BEGIN TO SHIFT
FURTHER EASTWARD TODAY...WITH 850MB TEMPS PROGGED TO RISE INTO THE
20 TO 22C RANGE ACROSS CENTRAL ILLINOIS. THIS WILL ALLOW HIGH TEMPS
TO REACH THE MIDDLE TO UPPER 90S. DEWPOINTS WILL GENERALLY BE IN
THE UPPER 60S TO AROUND 70...PRODUCING PEAK AFTERNOON HEAT INDEX
VALUES OF AROUND 100. EVEN HOTTER WEATHER IS IN STORE FOR
TUESDAY...AS THERMAL RIDGE AXIS AHEAD OF APPROACHING COLD FRONT
BOOSTS 850MB TEMPS TO BETWEEN 22 AND 24C. HIGH TEMPERATURES ON
TUESDAY WILL EASILY REACH THE UPPER 90S...WITH MANY LOCATIONS
ACROSS THE W/NW KILX CWA REACHING THE 100 DEGREE MARK. DESPITE THE
INTENSE HEAT...DEWPOINTS WILL MIX INTO THE UPPER 60S DURING THE
AFTERNOON...KEEPING THE HEAT INDEX JUST BELOW ADVISORY CRITERIA IN
THE 100 TO 105 DEGREE RANGE.
MODELS CONTINUE TO ADVERTISE A TEMPORARY SUPPRESSION OF THE
CENTRAL CONUS RIDGE BY MID-WEEK...AS DEEP UPPER LOW CURRENTLY OVER
HUDSON BAY SHIFTS SOUTHEASTWARD INTO QUEBEC/NORTHERN NEW ENGLAND.
THIS WILL HELP PUSH A WEAK COLD FRONT SOUTHWARD INTO ILLINOIS ON
WEDNESDAY. 00Z 16 JUL NAM/ECMWF HAVE BOTH CONTINUED THE WELL
ESTABLISHED SLOWING TREND...KEEPING FRONT TO THE NORTH UNTIL
WEDNESDAY NIGHT/THURSDAY. AS SUCH...HAVE ADJUSTED POPS TO KEEP
WEDNESDAY MORNING DRY...WITH SCATTERED SHOWERS/STORMS DEVELOPING
BY AFTERNOON. HIGHEST RAIN CHANCES WILL BE FOCUSED ALONG/NORTH OF
I-74...WITH CHANCES TAPERING DOWN FURTHER S/SW. DUE TO ADDITIONAL
CLOUDS AND SCATTERED PRECIP...TEMPS WILL BE A COUPLE OF DEGREES
COOLER ON WEDNESDAY. HOWEVER...DUE TO MOISTURE POOLING IN THE
VICINITY OF THE APPROACHING BOUNDARY...HUMIDITY LEVELS WILL BE
HIGHER. THIS COULD POTENTIALLY PUSH HEAT INDEX VALUES ABOVE
ADVISORY CRITERIA ACROSS THE SE CWA WEDNESDAY AFTERNOON.
LONG TERM...THURSDAY THROUGH SUNDAY
MAIN QUESTION IN THE EXTENDED CONTINUES TO BE HOW FAR SOUTH THE
BOUNDARY WILL REACH BEFORE STALLING OUT AND EVENTUALLY DISSIPATING.
GFS CONTINUES TO BE THE MOST AGGRESSIVE WITH ITS SOUTHWARD
PUSH...TAKING THE FRONT S/SW OF THE AREA BY THURSDAY NIGHT/FRIDAY.
GIVEN DOMINANT UPPER RIDGE ACROSS THE CENTER OF THE COUNTRY...THIS
SEEMS QUITE UNLIKELY. PREFER THE LESS AGGRESSIVE ECMWF/CANADIAN
SOLUTION...WHICH STALLS THE BOUNDARY ACROSS CENTRAL ILLINOIS
THROUGH FRIDAY...BEFORE WASHING IT OUT OVER THE WEEKEND AS UPPER
HEIGHTS BEGIN TO BUILD. WITH BOUNDARY PRESENT IN A HOT/HUMID
AIRMASS...THINK CHANCE POPS ARE WARRANTED BOTH THURSDAY AND
FRIDAY. AFTER THAT...WILL GO WITH A HOT AND DRY FORECAST NEXT
WEEKEND...WITH HIGHS WELL INTO THE 90S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1043 AM CDT MON JUL 16 2012
.DISCUSSION...
ISSUED 1045 AM CDT MON JUL 16 2012
FORECAST GENERALLY ON TRACK TODAY AND THE ONLY UPDATE THAT
WE MAY DO IS TO ADD SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
IN SOUTHEAST IL (SE OF I-70) THIS AFTERNOON WHERE SCATTERED
CUMULUS CLOUDS HAVE DEVELOPED BY LATE MORNING. NAM MODEL KEEPS IT
DRY OVER CENTRAL AND SE IL WHILE HRRR MODEL DEVELOPS SCATTERED
CONVECTION ACROSS CWA THIS AFTERNOON THOUGH THINK THIS IS WAY
OVERDONE ESPECIALLY OVER CENTRAL IL WHERE ITS STILL SUNNY. SREF
MODELS HAS SOME QPF OVER SOUTHERN AREAS THIS AFTERNOON. HOT AND
HUMID TODAY WITH HIGHS IN THE MID TO UPPER 90S. THIS HEAT COMBINED
WITH DEWPOINTS IN THE UPPER 60S AND LOWER 70S WILL GIVE HEAT
INDICES AROUND 100F THIS AFTERNOON. EVEN HOTTER TUESDAY WITH HIGHS
NEAR 100F AND HEAT INDICES PEAKING FROM 100-105F TUESDAY AFTERNOON.
HUETTL
&&
.AVIATION...
ISSUED 700 AM CDT MON JUL 16 2012...FOR THE 12Z TAFS
VFR CONDITIONS ARE EXPECTED THROUGH 12Z TUES UNDER HOT AND HUMID
HIGH PRESSURE. SOME LIGHT FOG MAY FORM LATER TONIGHT...BUT ONLY A
BRIEF PERIOD OF MVFR FOG IS ALL THAT WOULD OCCUR. WE KEPT FOG OUT
OF THE TAFS AS IT HAS BEEN VERY SPORADIC IN THIS AIRMASS SO FAR.
WINDS WILL REMAIN SOUTH-SOUTHWEST THROUGH TUES NIGHT...WITH SOME
AFTERNOON SUSTAINED WINDS OF 10-12KT POSSIBLE.
ANY CUMULUS FORMATION TODAY SHOULD REMAIN SCT. EVEN IF A BRIEF
BROKEN DECK FORMS...IT WILL BE AT VFR LEVELS.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 248 AM CDT MON JUL 16 2012
EVENING UPPER AIR ANALYSIS SHOWS LARGE RIDGE OF HIGH PRESSURE
DOMINATING MUCH OF THE CONUS...WITH TROUGHING EVIDENT WEST OF THE
ROCKIES AND ACROSS NEW ENGLAND. 850MB TEMPS BENEATH THE RIDGE AXIS
WERE AT OR ABOVE 30C ACROSS THE WESTERN DAKOTAS INTO
NEBRASKA...RESULTING IN HIGH TEMPS WELL ABOVE 100 DEGREES
YESTERDAY AFTERNOON.
SHORT TERM...TODAY THROUGH WEDNESDAY
HEART OF HOT AIRMASS CENTERED OVER THE PLAINS WILL BEGIN TO SHIFT
FURTHER EASTWARD TODAY...WITH 850MB TEMPS PROGGED TO RISE INTO THE
20 TO 22C RANGE ACROSS CENTRAL ILLINOIS. THIS WILL ALLOW HIGH TEMPS
TO REACH THE MIDDLE TO UPPER 90S. DEWPOINTS WILL GENERALLY BE IN
THE UPPER 60S TO AROUND 70...PRODUCING PEAK AFTERNOON HEAT INDEX
VALUES OF AROUND 100. EVEN HOTTER WEATHER IS IN STORE FOR
TUESDAY...AS THERMAL RIDGE AXIS AHEAD OF APPROACHING COLD FRONT
BOOSTS 850MB TEMPS TO BETWEEN 22 AND 24C. HIGH TEMPERATURES ON
TUESDAY WILL EASILY REACH THE UPPER 90S...WITH MANY LOCATIONS
ACROSS THE W/NW KILX CWA REACHING THE 100 DEGREE MARK. DESPITE THE
INTENSE HEAT...DEWPOINTS WILL MIX INTO THE UPPER 60S DURING THE
AFTERNOON...KEEPING THE HEAT INDEX JUST BELOW ADVISORY CRITERIA IN
THE 100 TO 105 DEGREE RANGE.
MODELS CONTINUE TO ADVERTISE A TEMPORARY SUPPRESSION OF THE
CENTRAL CONUS RIDGE BY MID-WEEK...AS DEEP UPPER LOW CURRENTLY OVER
HUDSON BAY SHIFTS SOUTHEASTWARD INTO QUEBEC/NORTHERN NEW ENGLAND.
THIS WILL HELP PUSH A WEAK COLD FRONT SOUTHWARD INTO ILLINOIS ON
WEDNESDAY. 00Z 16 JUL NAM/ECMWF HAVE BOTH CONTINUED THE WELL
ESTABLISHED SLOWING TREND...KEEPING FRONT TO THE NORTH UNTIL
WEDNESDAY NIGHT/THURSDAY. AS SUCH...HAVE ADJUSTED POPS TO KEEP
WEDNESDAY MORNING DRY...WITH SCATTERED SHOWERS/STORMS DEVELOPING
BY AFTERNOON. HIGHEST RAIN CHANCES WILL BE FOCUSED ALONG/NORTH OF
I-74...WITH CHANCES TAPERING DOWN FURTHER S/SW. DUE TO ADDITIONAL
CLOUDS AND SCATTERED PRECIP...TEMPS WILL BE A COUPLE OF DEGREES
COOLER ON WEDNESDAY. HOWEVER...DUE TO MOISTURE POOLING IN THE
VICINITY OF THE APPROACHING BOUNDARY...HUMIDITY LEVELS WILL BE
HIGHER. THIS COULD POTENTIALLY PUSH HEAT INDEX VALUES ABOVE
ADVISORY CRITERIA ACROSS THE SE CWA WEDNESDAY AFTERNOON.
LONG TERM...THURSDAY THROUGH SUNDAY
MAIN QUESTION IN THE EXTENDED CONTINUES TO BE HOW FAR SOUTH THE
BOUNDARY WILL REACH BEFORE STALLING OUT AND EVENTUALLY DISSIPATING.
GFS CONTINUES TO BE THE MOST AGGRESSIVE WITH ITS SOUTHWARD
PUSH...TAKING THE FRONT S/SW OF THE AREA BY THURSDAY NIGHT/FRIDAY.
GIVEN DOMINANT UPPER RIDGE ACROSS THE CENTER OF THE COUNTRY...THIS
SEEMS QUITE UNLIKELY. PREFER THE LESS AGGRESSIVE ECMWF/CANADIAN
SOLUTION...WHICH STALLS THE BOUNDARY ACROSS CENTRAL ILLINOIS
THROUGH FRIDAY...BEFORE WASHING IT OUT OVER THE WEEKEND AS UPPER
HEIGHTS BEGIN TO BUILD. WITH BOUNDARY PRESENT IN A HOT/HUMID
AIRMASS...THINK CHANCE POPS ARE WARRANTED BOTH THURSDAY AND
FRIDAY. AFTER THAT...WILL GO WITH A HOT AND DRY FORECAST NEXT
WEEKEND...WITH HIGHS WELL INTO THE 90S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
342 PM EDT MON JUL 16 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST OUT OF THE GREAT LAKES AND THROUGH
SOUTHERN CANADA ON TUESDAY. A COLD FRONT WILL PUSH ACROSS NEW
ENGLAND DURING THE EVENING ON TUESDAY WITH SHOWERS AND
THUNDERSTORMS EXPECTED IN THE HOT AND HUMID AIR MASS AHEAD OF THE
FRONT. THE FRONT MOVES FULLY THROUGH THE REGION ON WEDNESDAY WITH
COOLER AND DRIER AIR BEHIND IT. HIGH PRESSURE BUILDS DOWN OUT OF
CANADA THROUGH THE END OF THE WEEK. ANOTHER DISTURBANCE IS
FORECAST TO APPROACH NEW ENGLAND EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST HRRR MODEL RUNS CONTINUE TO CAPTURE CONVECTION DRIFTING
SOUTHEAST OUT OF THE INTERIOR THIS AFTERNOON. THIS PRECIPITATION
SHOULD WIND DOWN AFTER SUNSET THIS EVENING. MCS OVER THE GREAT
LAKES CONTINUES TO WEAKEN AND HEAD RAPIDLY EAST TOWARDS OUR
REGION. THIS WILL SPILL ADDITIONAL CLOUD COVER TO THE REGION LATE
TONIGHT.
PATCHY FOG WILL DEVELOP OVER THE MARINE LAYER AND ACROSS THE
INTERIOR VALLEYS OVERNIGHT. USED A BLEND OF MAV/MET NUMBERS FOR
OVERNIGHT MINS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
STRONG WARM AIR ADVECTION WILL BE PRESENT OVER WESTERN PORTIONS OF
THE FORECAST AREA BY AROUND 12Z. THIS MAY TRIGGER A FEW SHOWERS
OR THUNDERSTORMS DURING THE EARLY MORNING HOURS.
A BLAST OF VERY WARM AIR WILL ENTER THE REGION WITH SOUTHERN ZONES
PEAKING OUT AT OR ABOVE +20C AT 850MB. THIS WILL ALLOW MID/UPPER
90S TO SOUTHERN INTERIOR SECTIONS. WITH CURRENT DEW POINTS FORECAST
TO BE IN THE MID 60S IN THIS LOCATION TOMORROW AFTERNOON...EXPECT
HEAT INDEX VALUES TO BE CLOSE TO 100 DEGREES. CURRENT GRIDS ARE
FORECAST TO BE JUST BELOW THE HEAT ADVISORY CRITERIA FOR A FEW
HOURS TUESDAY AFTERNOON. THEREFORE...WILL NOT BE ISSUING HEAT
ADVISORIES AT THIS TIME.
A ROUND OF STRONG TO SEVERE STORMS IS EXPECT TO ROLL OUT OF
NORTHERN AREAS DURING THE MID/LATE AFTERNOON HOURS. SPC HAS US IN
SLIGHT RISK. WITH INSTABILITY VALUES INCREASING...EXPECT POSSIBLE
LARGE HAIL...DAMAGING WINDS AND LOCALLY VERY HEAVY RAINFALL. HAVE
ADDED THIS ENHANCED WORDING TO MUCH OF THE NORTHERN HALF OF THE
FORECAST AREA. TRICK WILL BE THE TIMING OF THE SURFACE COLD FRONT
AND ANY PRE-FRONTAL TROUGHS. DIRECTIONAL SHEAR ACROSS MUCH OF MAINE
WILL ALSO BE FAVORABLE FOR A FEW ISOLATED TORNADOES IF CONDITIONS
LINE UP JUST RIGHT WITH LOW LEVEL SOUTHERLY WINDS AND MID/UPPER
LEVEL WESTERLIES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...MODEL DISCREPANCIES ARE
THE KEY TO THE WEDNESDAY FORECAST. MODEL TRENDS HAVE BEEN SLOWING
THE SOUTHWARD PROGRESSION OF THE FRONT...LEAVING THE SOUTHERN HALF
OF NEW HAMPSHIRE AND FAR SOUTHWESTERN MAINE SUSCEPTIBLE TO ANOTHER
OPPORTUNITY FOR THUNDERSTORMS ALONG THE FRONT WEDNESDAY AFTERNOON.
AT THIS TIME THERE IS STILL ENOUGH UNCERTAINTY NOT TO BITE ON ANY
SEVERE WEATHER POTENTIAL BUT IT BEARS WATCHING AS THIS WILL BE A
POTENT FRONT WITH A LOT OF HEATING OUT AHEAD OF IT.
BEYOND LINGERING SHOWERS ON WEDNESDAY NIGHT...THE FRONT CLEARS AND
HIGH PRESSURE BUILDS OVER THE AREA AS A COOL UPPER TROUGH CARVES
OUT OVER NEW ENGLAND AND THE CANADIAN MARITIMES. AS THE TROUGH
MOVES OFFSHORE ON SUNDAY...HEIGHTS AND TEMPERATURES RISE AS WILL
THE HUMIDITY INTO MONDAY...WITH ANOTHER DISTURBANCE APPROACHING BY
TUESDAY. A MIX OF THE HPC AND GRIDDED MOS GUIDANCE WAS USED FOR
THE MEDIUM RANGE FORECAST.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM...MAINLY VFR CONDITIONS THIS EVENING. HOWEVER THERE
WILL BE IFR CONDITIONS IN QUICK PASSING SHOWERS. PATCHY FOG WILL
DEVELOP AROUND MIDNIGHT. LOCALLY LIFR CONDITIONS IN STRONG STORMS
TUESDAY AFTERNOON AND EVENING...MAINLY OVER NORTHERN AREAS.
LONG TERM...ON WEDNESDAY...SOUTHERN MAINE AND SOUTHERN AND
CENTRAL NEW HAMPSHIRE ARE EXPECTED TO SEE ADDITIONAL PRECIPITATION
AND MVFR/IFR CONDITIONS AS THE FRONT SLOWLY SAGS THROUGH THE AREA.
HIGH PRESSURE BUILDS OVER THE AREA FOR VFR CLEAR CONDITIONS
THURSDAY THROUGH SATURDAY.
&&
.MARINE...
SHORT TERM...WEAK LOW PRESSURE MOVES OUT OF THE GULF OF MAINE
TONIGHT WITH LIGHT WINDS AND SEAS. WINDS INCREASE OUT OF THE SOUTH
ON TUESDAY AHEAD OF A COLD FRONT. GUSTS MAY APPROACH 25 KT BY
TUESDAY AFTERNOON.
LONG TERM...EXPECT THE SEAS TO SUBSIDE AND WINDS TO DIMINISH ON
WEDNESDAY WITH THE PASSAGE OF THE FRONT. WINDS AND SEAS RELAX EVEN
FURTHER LATE IN THE WEEK AS HIGH PRESSURE BUILDS IN.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIMBLE
NEAR TERM...CANNON
SHORT TERM...CANNON
LONG TERM...ST JEAN
AVIATION...CANNON/ST JEAN
MARINE...KIMBLE/ST JEAN
AREA FORECAST DISCUSSION
NWS GRAY ME
132 PM EDT MON JUL 16 2012
.SYNOPSIS...
LOW PRESSURE WILL WEAKEN AS IT MOVES EAST OUT OF THE GULF OF MAINE
THIS AFTERNOON. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD OVER THE
AREA TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON
TUESDAY AND WILL CROSS THE REGION TUESDAY NIGHT. HIGH PRESSURE
WILL BUILD IN FROM THE NORTHWEST WEDNESDAY THROUGH SATURDAY AND
WILL MOVE OFFSHORE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
NO SIGNIF CHANGES TO THE LATEST GRID PACKAGE. HAVE UPPED POPS AS
BRIEF SHOWERS AND A FEW ISOLD TSTMS WILL CONTINUE TO MOVE SE
EMBEDDED IN A WEAK NW FLOW. LATEST HRRR MDL RUN APPEARS TO HAVE A
GOOD HANDLE ON THIS CONVECTION.
TEMPS WILL CONT TO CLIMB THRU THE MID AND UPPER 80S OVER INLAND
AREAS FOR THE NEXT FEW HOURS. A FEW LOCATIONS IN SRN NH WILL
APPROACH OR EXCEED 90 DEGREES PER LATEST OBS.
PREV DISC...
SHORTWAVE WILL PUSH EAST OF THE FORECAST AREA EARLY TODAY.
SHOWER ACTIVITY ASSOCIATED WITH THIS SYSTEM WILL GRADUALLY WIND
DOWN THROUGH DAYBREAK. LOW CLOUDS AND AREAS OF FOG WILL GRADUALLY
CLEAR OUT THROUGH MID MORNING WITH HAZY SUNSHINE DEVELOPING ACROSS
MUCH OF THE FORECAST AREA BY AFTERNOON. AFTERNOON SHOWERS AND
THUNDERSTORMS WILL DEVELOP IN THE MODERATELY UNSTABLE ATMOSPHERE
WITH THE BEST CHANCE OF PRECIPITATION IN NORTHERN ZONES. LOOKING
FOR HIGHS RANGING THROUGH THE 80S TO NEAR 90 WITH A DEVELOPING SEA
BREEZE KEEPING COASTAL AREAS SOMEWHAT COOLER.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
SHOWERS AND THUNDERSTORMS WILL GRADUALLY DIMINISH THIS EVENING
WITH THE LOSS OF DAYTIME HEATING. WILL SEE VARIABLE CLOUDINESS AS
A WEAK RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. WILL BE
ANOTHER MILD NIGHT WITH LOWS RANGING THROUGH THE 60S.
COLD FRONT WILL APPROACH FROM THE NORTHWEST ON TUESDAY. EXPECT
AFTERNOON SHOWERS AND THUNDERSTORMS TO DEVELOP IN NORTHERN ZONES
IN THE AFTERNOON. INCREASING SHEAR AND INSTABILITY AHEAD OF THE
FRONT WILL SET THE STAGE FOR SOME STRONG AFTERNOON AND EVENING
THUNDERSTORMS IN THE NORTH AND THESE WILL SHIFT INTO CENTRAL
PORTIONS OF MAINE AND NEW HAMPSHIRE BY LATE IN THE DAY. WILL BE
ANOTHER HOT ONE WITH TEMPS RANGING THROUGH THE 80S TO NEAR 90.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A CD FNT MOVES THRU TUESDAY NGT AND EARLY WEDNESDAY WITH SHRA AND
TSTM ACTIVITY. BEST CHC ACROSS N/MT ZONES. FNT MOVES OUT TO SEA
WEDNESDAY AS THE AIR MASS BEGINS TO CHANGE WITH LOWER TEMPS AND
HUMIDITY MOVING IN. SHOULD STILL BE A WRM DAY...BUT NOT
EXCESSIVELY HOT WITH THE DROP IN HUMIDITY MORE NOTICEABLE...THOUGH
THIS MAY TAKE AWHILE OVER MORE SRN/COASTAL AREAS DURING THE DAY.
HIGH PRES BUILDS DOWN FROM CANADA WEDNESDAY NGT THRU SATURDAY NGT
BRINGING MORE PLEASANT SUMMER WX WITH NEAR SEASONABLE DAYTIME
TEMPS AND AT OR BELOW NORMAL OVERNIGHT LOWS WITH COMFORTABLE DEW
POINTS/HUMIDITY LEVELS. THERE WILL BE A BROAD DISORGANIZED UPR LVL
TROF MOVING THRU FRIDAY INTO SATURDAY WHICH WILL LIKELY CAUSE SOME
INSTABILITY CLOUDS BUT IT SHOULD BE MAINLY DRY THOUGH AN ISOLD
-SHRA MAY BE PSBL.
UPR LVL RIDGE BUILDING IN AS THE SFC HIGH MOVES OFF TO OUR SE
ALLOWING A SURGE OF WARMER AND MORE HUMID AIR TO MOVE IN ON W SW
FLOW ON SUNDAY. SHOULD SEE A RETURN TO VERY WRM AND HUMID
CONDITIONS.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR
TUESDAY NGT AND WEDNESDAY. FOR REST OF THE LONG TERM FCST USED
GMOS...EXCEPT USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX
AND MIN TEMPS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM...VFR CONDS FOR THE REST OF TDA...EXCEPT LCLY MVFR IN
ANY BRIEF SHOWERS AND ISOLD TSTMS.
LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...A CD FNT MOVES THRU
TUESDAY NGT AND EARLY WEDNESDAY WITH SCT SHRA/TSTMS WITH MVFR TO
PSBL IFR CONDITIONS.
&&
.MARINE...
SHORT TERM...NO FLAGS.
LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...WINDS AND SEAS WILL
STAY BELOW SCA LEVELS THRU THE LONG TERM FCST PERIOD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
753 PM EDT TUE JUL 17 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
COLD FRONT IS WELL TO THE SOUTH OF UPPER MICHIGAN AS PORTIONS OF
SOUTHERN WICSONSIN AND LOWER MICHIGAN CONTINUE TO BAKE. YET...DRY
DAY THAT WAS SUPPOSED TO BE OVER MOST OF THE AREA HAS HAD TOUGH TIME
TAKING SHAPE. MAIN CULPRIT FOR THE SHRA CURRENTLY ROAMING CNTRL UPR
MICHIGAN SEEMS TO HAVE BEEN A SUBTLE H6-H5 JET STREAK ALONG WITH
RIBBON OF LINGERING HIGHER H7 DWPNTS ACROSS THE AREA. ADDITIONAL
LIFT IS PROVIDED BY A WEAK SHORTWAVE NOW PUSHING INTO WESTERN LK
SUPERIOR. BULK OF ANY TSRA HAVE STAYED OVR NORTHERN WISCONSIN ALONG
NORTH EDGE OF 1-6KM MUCAPE GRADIENT. SHRA IN THE NORTH HAVE NOT
BEEN ALL THAT HEAVY...WITH ONLY A FEW HUNDREDTHS OBSERVED AT RAIN
GAGES OVR WESTERN UPR MICHIGAN THIS AFTN. EXPECT ALL THE MENTIONED
FORCING MECHANISMS TO DRIFT SOUTH OUT OF THE AREA EARLY THIS EVENING
AND HAVE PUT AN END TO POPS AT THAT TIME. RAPID REFRESH RUC MODEL
/HRRR/ WHICH DID NOT DO WELL SHOWING THE SHRA/TSRA FOR MUCH OF THE
MORNING FINALLY CAUGHT ON BY EARLY THIS AFTN...AND FCSTS A SIMILAR
FATE TO PRECIP THIS EVENING.
CLEARING SKIES THEN EXPECTED FM NORTHWEST TO SOUTHEAST THROUGH THE
EVENING. THINK THE CLEARING COULD LEAD TO FOG OVERNIGHT TONIGHT
THROUGH EARLY WEDNESDAY MORNING. PLUSES FOR FOG FORMATION ARE ADDED
SFC MOISTURE FROM THE RAIN TODAY/MINIMAL MIXING OR DRYING TODAY
ALONG WITH FAIRLY LIGHT WINDS/COOLING TEMPS. BEST CHANCE FOR FOG
WILL BE OVER WEST HALF AND ALSO WHERE NORTHEAST WINDS UPSLOPE
/HIGHER TERRAIN OF WEST AND NORTH CENTRAL/. LOOKS LIKE AM ON MY
OWN ON THIS ONE THOUGH AS NO GUIDANCE HAS REALLY ANY HINT OF FOG
TONIGHT. GIVEN THOSE SIGNALS...IT IS TOUGH TO GO WITH ANYTHING MORE
THAN PATCHY FOG AT THIS POINT.
IF ANY FOG/STRATUS DEVELOPS TONIGHT IT WILL DEPART SHORTLY AFTER
SUNRISE ON WEDNESDAY MORNING SINCE IT WILL SFC BASED/SHALLOW. WITH
MAINLY SUNNY SKIES FOR THE AFTN HIGH TEMPS SHOULD RISE WELL INTO
THE 70S MOST AREAS WITH EVEN SOME LOWER 80S POSSIBLE TOWARD THE
WISCONSIN BORDER. DAYTIME MIXING WILL RESULT IN LESS HUMID
CONDITIONS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
AREA WILL BE BETWEEN TWO UPPER TROUGHS ON WED NIGHT...ONE OVER
QUEBEC AND THE OTHER OVER THE PAC NW. THIS WILL LEAD TO A RIDGE
OVER THE NRN PLAINS AND CANADIAN PRAIRIES THAT WILL TRY TO PUSH
EAST TOWARDS THE CWA...BUT WILL BE HELD OFF REINFORCING NRN STREAM
WAVES ATTEMPTING TO KEEP THE UPPER TORUGH OVER QUEBEC. THIS WILL
PUT THE CWA ON THE EDGE OF THE WARM TEMPS THIS WEEKEND...UNTIL THE
UPPER RIDGE FINALLY MOVES OVERHEAD DURING THE BEGINNING OF NEXT
WEEK.
CANADIAN HIGH PRESSURE RIDGE WILL BE OVER UPPER MI ON WED NIGHT AND
THEN GRADUALLY SHIFT SOUTHEAST THROUGH THE REST OF THE WORK WEEK AS
THE TROUGH OVER QUEBEC MOVES INTO THE NEW ENGLAND STATES. MODELS
CONSISTENT ON A SHORTWAVE SLIDING THROUGH THE FLOW ON WED NIGHT INTO
THURS...BUT VARY CONSIDERABLY ON THE LOCATION/INTENSITY. ECMWF IS
THE FARTHEST N AND STRONGEST WITH THE LLVL WAA OVER NRN WI...WHILE
THE REST OF THE MODELS ARE MUCH WEAKER WITH THE WAA AND FARTHER SW.
DRY AIR DOES TRY TO BREAK DOWN THE MOISTURE IN THE MID LVLS OVER THE
SW HALF OF THE CWA WED NIGHT INTO THURS MORNING...BEFORE DIMINISHING
IN THE AFTN. LLVL DRY AIR WILL LIKELY KEEP IT MID CLOUDS AND WITH
THE BEST FORCING LIKELY STAYING TO THE S...WANTED TO KEEP POPS
IN NRN WI. BUT WITH 12Z ECMWF CONTINUING TO SHOW PCPN MAKING IT
INTO UPPER MI...WILL CONTINUE MENTION SLIGHT CHANCES JUST OVER
THE WI BORDER.
OTHERWISE...HIGH PRESSURE RIDGE AND DRY CANADIAN AIR WILL KEEP THE
AREA MOSTLY/PARTLY CLEAR INTO FRI. TEMPS WILL BE SLIGHTLY ABOVE
NORMAL ON THURS AND THEN WARM SLIGHTLY ON FRI...AS WARM AIR ALOFT
STARTS TO WORK E AND BACK OVER THE CWA.
NRN STREAM WAVE SLIDING THROUGH CNTRL CANADA FRI NIGHT AND INTO NRN
ONTARIO WILL TRY TO PUSH A COLD FRONT TOWARDS THE AREA ON SAT INTO
SUN. IT ACTUALLY MOVES INTO NRN MN ON FRI...BUT STALLS AS IT
RUNS INTO THE SFC HIGH OVER UPPER MI. WITH IT BEING A GOOD WAYS AWAY
FROM IT/S SOURCE...AND LIMITED CONVERGENCE...EXPECT PCPN TO BE
SCATTERED ALONG THE FRONT. THUS...WILL CONTINUE TO MENTION SLIGHT
AND LOW CHANCE POPS FRI NIGHT INTO SUN. FRONT FINALLY SLIDES S OF
THE AREA ON SUN NIGHT AND WILL END PCPN CHANCE AT THAT POINT.
UPPER RIDGE THEN REALLY BUILDS IN MON/TUES AS ANOTHER CANADIAN HIGH
PRESSURE RIDGE SLIDES INTO THE AREA. THERE ARE A FEW
WEAK SHORTWAVES TRYING TO ROUND THE RIDGE...BUT WITH LITTLE
TO NO INSTABILITY...WILL KEEP THE FORECAST DRY FOR MON AND
MON NIGHT. ANOTHER COLD FRONT WILL LIKELY APPROACH THE UPPER GREAT
LAKES LATE TUES AFTN AND INTO WED...SO HAVE BROUGHT IN CHANCES
OVER THE WEST. HIGHS ARE STILL EXPECTED TO BE ABOVE NORMAL THROUGH
THE PERIOD...IN THE 80S AND LOW 90S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 752 PM EDT TUE JUL 17 2012
THERE IS SOME CONCERN THAT FOG MAY DEVELOP TONIGHT AFTER ADDED
MOISTURE FROM LIGHT SHOWERS TODAY AND AS NIGHTTIME COOLING LEADS
TO BASED INVERSION. THE BEST CHANCE FOR FOG WILL BE AT KSAW WITH
IDEAL UPSLOPE LOW-LEVELS WIND FCST. THERE IS POTENTIAL FOR
CONDITIONS TO FALL BLO ALTERNATE MINS OVERNIGHT TONIGHT.
HOWEVER...CONFIDENCE IS LOW GIVEN SLOW INFLUX OF DRIER AIR INTO THE
REGION WITH WEAK LOW LEVEL ACYC FLOW. ELSEWHERE...LIGHTER FOG IS
POSSIBLE AS WINDS ARE NOT AS FAVORABLE FOR UPSLOPE. IF WINDS BECOME
LIGHT ENOUGH THOUGH...COULD SEE PATCHY DENSE FOG AT KIWD AND KCMX AS
WELL. VFR CONDITIONS ARE EXPECTED AFTER ANY LOW CLOUDS/FOG DIMINISH
WEDNESDAY MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 343 PM EDT TUE JUL 17 2012
HIGH PRES BUILDING S TOWARD THE UPPER LAKES WILL ARRIVE IN FULL
FORCE LATE TONIGHT INTO WEDNESDAY. THE HIGH WILL REMAIN OVERHEAD
THROUGH THE UPCOMING WEEKEND...SO WINDS WILL BE ON THE LIGHT SIDE...
MAINLY LESS THAN 15 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 PM EDT MON JUL 16 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EDT MON JUL 16 2012
MAIN FCST CONCERNS IN THE SHORT TERM WILL BE THE HOT WEATHER TODAY
AND WHETHER OR NOT ANY CONVECTION DEVELOPS TODAY/TONIGHT. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE FAR WRN CONUS
WITH A BROAD RIDGE DOWNSTREAM ACROSS THE CNTRL CONUS. AS
EXPECTED...SHORTWAVE ENERGY RIDING AROUND THE RIDGE IS CURRENTLY
SUPPORTING SHRA/TSRA ACROSS SRN MANITOBA INTO NRN MN AND ADJACENT
NRN ONTARIO. IN RESPONSE TO THE SHORTWAVE ENERGY...A STRONG
LOW-LEVEL JET (50-60KT PER LATEST RUC ANALYSIS) IS ALIGNED FROM
NCNTRL NEBRASKA TO NW MN AND IS THE MAIN DRIVER FOR THE CONVECTION.
THE LOW-LEVEL JET WILL VEER AND TRANSLATE ACROSS THE UPPER LAKES
TODAY. AS HAS BEEN THE CASE OVER THE LAST COUPLE OF DAYS...THE GFS
CONTINUES TO BE FARTHER S WITH THE NOSE OF THE LOW-LEVEL JET
COMPARED TO OTHER GUIDANCE...RESULTING IN MORE WIDESPREAD PCPN
ACROSS THE FCST AREA TODAY. GIVEN THE OVERWHELMING CONSENSUS OF
OTHER MODEL GUIDANCE...WILL LEAN AWAY FROM THE GFS SCENARIO TODAY.
THUS...EXPECT MAIN AREA OF SHRA/TSRA TO SLIDE ACROSS NRN LAKE
SUPERIOR/NRN ONTARIO WHERE LOW-LEVEL JET RIDING OVERTOP MARINE LAYER
WILL CONTINUE TO YIELD RATHER STRONG FORCING. THAT SAID...AS IS
CURRENTLY OCCURRING TO THE W...CAN`T RULE OUT ISOLD/SCT SHRA/TSRA
ACROSS MAINLY NRN UPPER MI AND THE KEWEENAW IN PARTICULAR AS THE
AXIS OF THE LOW-LEVEL JET TRANSLATES ACROSS THE AREA. IF STRONGER
CONVECTION PASSES OVER LAKE SUPERIOR TODAY...OUTFLOW ENHANCED BY THE
MARINE LAYER COULD SET UP A SHARP SFC BOUNDARY THAT PUSHES S INTO
NRN UPPER MI. THAT COULD THEN BECOME A FOCUS FOR CONVECTIVE
DEVELOPMENT THIS AFTN. WILL BE SOMETHING TO MONITOR DURING THE DAY.
WITH 1000-1500J/KG OF MLCAPE PER NAM (GFS IS OVERLY MOIST IN THE
LOW-LEVELS) AND 35-45KT OF DEEP LAYER SHEAR...ISOLD SVR WX IS
POSSIBLE IF STORMS DO OCCUR TODAY.
AS FOR TEMPS...WITH S TO SW WINDS INCREASING TODAY...MOST AREAS WITH
THE EXCEPTION OF LOCATIONS CLOSE TO LAKE MICHIGAN AND POSSIBLY THE
KEWEENAW PENINSULA SHOULD HAVE NO PROBLEM REACHING THE LOW/MID 90S
TODAY PER MIXING TO AROUND 800MB ON NAM FCST SOUNDINGS. THESE TEMPS
ARE INLINE WITH WHAT WAS OBSERVED UPSTREAM FROM IA TO THE DAKOTAS
YESTERDAY. IT COULD BE A LITTLE WARMER IF THERE IS LESS CLOUD COVER
AND MIXING HEIGHTS BUILD A BIT HIGHER. RECORD HIGH OF 93 HERE AT THE
OFFICE MAY FALL. AT THIS POINT...EXPECT HOT CONDITIONS RIGHT TO THE
LAKE SUPERIOR SHORE...WITH LOCAL EXCEPTIONS AROUND THE KEWEENAW.
HOWEVER...IF SHRA/TSRA MOVING ACROSS LAKE SUPERIOR PUSH
OUTFLOW/MARINE LAYER S...TEMPS WILL OBVIOUSLY END UP LOWER THAN
CURRENTLY EXPECTED CLOSE TO THE LAKE. AS WAS THE CASE UPSTREAM
YESTERDAY...MIXING SHOULD HELP KEEP DWPTS IN CHECK AND PREVENT
AGGRAVATING THE HEAT WITH HIGHER APPARENT TEMPS. LEANED TOWARD THE
NAM IDEA WITH DWPTS GENERALLY IN THE LOW/MID 60S OVER THE W HALF OR
SO OF UPPER MI. HIGHER DWPTS WILL BE FOUND OVER THE ERN FCST AREA
DOWNWIND OF LAKE MICHIGAN...BUT TEMPS THERE WILL ALSO BE A LITTLE
LWR THAN OVER THE W. AS MIXING HEIGHTS BUILD AND TAP INTO LOW-LEVEL
JET...SHOULD SEE WIND GUSTS TO AROUND 30 MPH OR SO FOR AT LEAST A
FEW HRS THIS AFTN...ESPECIALLY OVER THE W HALF WHERE MIXING HEIGHTS
WILL BE GREATEST.
WEAK LOW PRES WILL CROSS LAKE SUPERIOR TONIGHT WITH COLD FRONT THEN
DROPPING S BEHIND IT. WHILE MANY MODELS THE LAST COUPLE OF DAYS HAD
INDICATED A GOOD AMOUNT OF PCPN MIGHT FALL ASSOCIATED WITH THIS
FROPA...RECENT GUIDANCE NOW INDICATES THE FROPA WILL BE MAINLY DRY.
PART OF THE ISSUE MAY BE THAT THE LOW-LEVEL JET WILL HAVE VEERED
WRLY WITH NOSE WELL OFF TO THE E...LIMITING IMPORTANT NIGHTTIME
FORCING FROM THE LOW-LEVEL JET HERE. IN ANY EVENT...PREVIOUS FCST
IDEA OF SLIGHT CHC/LOW CHC POPS APPEARS ON TRACK FOR NOW. FOG WHICH
COVERED MUCH OF LAKE SUPERIOR YESTERDAY AND IS NOW PUSHING BACK TO
THE N UNDER DEVELOPING SRLY FLOW MAY SWEEP BACK S WITH FROPA
TONIGHT...OR FOG MAY REDEVELOP AS COOLER MARINE LAYER SINKS S AND
ENCOUNTERS HIGHER DWPTS TOWARD SHORE AND IN UPSLOPING INTO UPPER MI.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 546 AM EDT MON JUL 16 2012
THE UPPER GREAT LAKES WILL BEGIN TO LOSE THE INFLUENCE OF THE LARGE
500MB LOW SPINNING ACROSS N QUEBEC...AS IT SLOWLY HEADS OFF INTO THE
ATLANTIC ON THURSDAY. THE SFC LOW SHOULD BE JUST SE OF THE
CWA...STRETCHING FROM N QUEBEC...THROUGH N LAKE HURON...TO S
CENTRAL/SE SD. DRIER CANADIAN HIGH PRESSURE WILL THE BUILD IN BEHIND
THE COLD FRONT. WITH BOOKEND LOWS OVER CANADA AND THE FAR N
U.S...THE 500MB RIDGE SHOULD BE ABLE TO BUILD BACK ACROSS THE
CENTRAL PLAINS BY MID WEEK...AND CONTINUE TO BUILD ACROSS THE UPPER
GREAT LAKES THROUGH AT LEAST SATURDAY.
BOTH 15/12Z RUNS OF THE CANADIAN AND ECMWF DEVELOPED AFTERNOON AND
EARLY EVENING SHOWERS NEAR THE WI BORDER THURSDAY. WILL ADJUST POPS
UP SLIGHTLY IN THIS AREA...BUT WILL FAVOR AN INCREASE IN SKY COVER
INSTEAD OF INCREASING POPS TO ANYTHING ABOVE SLIGHT CHANCE YET...AS
A RELATIVELY WEAK WAVE SLIDES IN ON THE NW FLOW ALOFT.
EXPECT MAINLY NORTHERLY FLOW TO DOMINATE OFF LAKE SUPERIOR...BEFORE
THE SFC HIGH SHIFTS TO OUR E FROM THURSDAY ON. WHILE TEMPERATURES
WILL BE ON THE INCREASE AGAIN TO MORE UNCOMFORTABLE LEVELS ACROSS
THE CENTRAL PLAINS...UPPER MI WILL BE PROTECTED FROM THE HEAT.
THE CANADIAN/ECMWF/ AND GFS ALL HAVE THE 500MB TROUGH OVER THE
PACIFIC NORTHWEST EJECTING NORTHEASTWARD...ATTEMPTING TO ROUND THE
HIGH AMPLITUDE RIDGE ACROSS THE NORTHERN PLAINS AND CENTRAL CANADA.
AS EXPECTED...TIMING OF THIS FEATURE AT 100 PLUS HOURS VARIES
SIGNIFICANTLY. THE 15/12Z CANADIAN WAS THE FASTEST...WITH THE 15/12Z
ECMWF BEING THE SLOWEST /SLOWER THAN THE CANADIAN BY OVER 18 HOURS
BY SATURDAY/. AS A RESULT OF THE DIFFERENCES...WILL RUN CLOSER TO
MODEL CONSENSUS FOR THE UPCOMING WEEKEND. WEEKEND TEMPS SHOULD
SLOWLY CLIMB BACK INTO THE UPPER 80S AND LOW 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 135 PM EDT MON JUL 16 2012
AS LOW-LEVEL JET SHIFTS ACROSS THE AREA TODAY...BUILDING MIXING
HEIGHTS WILL TAP STRONGER WINDS LEADING TO S TO SW WINDS GUSTING
20-30KT... PARTICULARLY AT KIWD/KSAW. COLD FRONT WILL DROP S ACROSS
THE AREA TONIGHT. SINCE FOG HAS BEEN PRESENT OVER LAKE
SUPERIOR...WIND SHIFT TO THE N SHOULD BRING IFR/POTENTIAL LIFR
CONDITIONS TO ALL SITES AFTER FROPA TONIGHT. VERY LOW CONFIDENCE IN
ANY PCPN ACCOMPANYING FRONT...SO PCPN WAS NOT MENTIONED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 546 AM EDT MON JUL 16 2012
MAIN FCST ISSUE IS MARINE FOG. AS OPPOSED TO 24HRS AGO WHEN
SATELLITE IMAGERY PROVIDED A GOOD VIEW OF FOG/STRATUS OVER THE
LAKE...MID/HIGH CLOUDS ARE OBSCURING THE FOG THIS MORNING. SO...WILL
ASSUME THAT WITH DEVELOPING SRLY FLOW THE FOG IS ADVECTING N ACROSS
THE LAKE WITH VIS IMPROVING FROM THE S. HAVE THUS OPTED TO LET DENSE
FOG ADVY EXPIRE AS SCHEDULED AT 10Z. AS COLD FRONT DROPS ACROSS LAKE
SUPERIOR TONIGHT...FOG MAY AGAIN BECOME AN ISSUE AT LEAST FOR A
TIME...ESPECIALLY IF MORE RAINFALL OCCURS ACROSS THE LAKE. AS DRIER
AIR BEGINS TO MAKE INROADS LATE TONIGHT/TUE...EXPECT FOG TO FINALLY
DISSIPATE.
AS FOR WINDS...LOCALLY GUSTY S-SW WINDS OF 20-25KT WILL BE POSSIBLE
AT TIMES IN THE NEARSHORE AREAS OF SRN LAKE SUPERIOR TODAY AS
SOUTHERLY WINDS INCREASE AHEAD OF APPROACHING LOW PRES. ALSO...A
PERIOD OF STRONGER WINDS POTENTIALLY UPWARDS OF 25KT OR SO MAY OCCUR
IN THE VCNTY OF THE COLD FRONT DROPPING ACROSS THE LAKE LATE THIS
AFTN AND THIS EVENING. OTHERWISE...WINDS SHOULD BE MOSTLY UNDER
20KT. WITH HIGH PRES DOMINATING WED-FRI...WINDS WILL LIKELY BE UNDER
15KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 8 AM EDT TUESDAY FOR LSZ244-245-263-264-
266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...TITUS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
742 AM EDT MON JUL 16 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EDT MON JUL 16 2012
MAIN FCST CONCERNS IN THE SHORT TERM WILL BE THE HOT WEATHER TODAY
AND WHETHER OR NOT ANY CONVECTION DEVELOPS TODAY/TONIGHT. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE FAR WRN CONUS
WITH A BROAD RIDGE DOWNSTREAM ACROSS THE CNTRL CONUS. AS
EXPECTED...SHORTWAVE ENERGY RIDING AROUND THE RIDGE IS CURRENTLY
SUPPORTING SHRA/TSRA ACROSS SRN MANITOBA INTO NRN MN AND ADJACENT
NRN ONTARIO. IN RESPONSE TO THE SHORTWAVE ENERGY...A STRONG
LOW-LEVEL JET (50-60KT PER LATEST RUC ANALYSIS) IS ALIGNED FROM
NCNTRL NEBRASKA TO NW MN AND IS THE MAIN DRIVER FOR THE CONVECTION.
THE LOW-LEVEL JET WILL VEER AND TRANSLATE ACROSS THE UPPER LAKES
TODAY. AS HAS BEEN THE CASE OVER THE LAST COUPLE OF DAYS...THE GFS
CONTINUES TO BE FARTHER S WITH THE NOSE OF THE LOW-LEVEL JET
COMPARED TO OTHER GUIDANCE...RESULTING IN MORE WIDESPREAD PCPN
ACROSS THE FCST AREA TODAY. GIVEN THE OVERWHELMING CONSENSUS OF
OTHER MODEL GUIDANCE...WILL LEAN AWAY FROM THE GFS SCENARIO TODAY.
THUS...EXPECT MAIN AREA OF SHRA/TSRA TO SLIDE ACROSS NRN LAKE
SUPERIOR/NRN ONTARIO WHERE LOW-LEVEL JET RIDING OVERTOP MARINE LAYER
WILL CONTINUE TO YIELD RATHER STRONG FORCING. THAT SAID...AS IS
CURRENTLY OCCURRING TO THE W...CAN`T RULE OUT ISOLD/SCT SHRA/TSRA
ACROSS MAINLY NRN UPPER MI AND THE KEWEENAW IN PARTICULAR AS THE
AXIS OF THE LOW-LEVEL JET TRANSLATES ACROSS THE AREA. IF STRONGER
CONVECTION PASSES OVER LAKE SUPERIOR TODAY...OUTFLOW ENHANCED BY THE
MARINE LAYER COULD SET UP A SHARP SFC BOUNDARY THAT PUSHES S INTO
NRN UPPER MI. THAT COULD THEN BECOME A FOCUS FOR CONVECTIVE
DEVELOPMENT THIS AFTN. WILL BE SOMETHING TO MONITOR DURING THE DAY.
WITH 1000-1500J/KG OF MLCAPE PER NAM (GFS IS OVERLY MOIST IN THE
LOW-LEVELS) AND 35-45KT OF DEEP LAYER SHEAR...ISOLD SVR WX IS
POSSIBLE IF STORMS DO OCCUR TODAY.
AS FOR TEMPS...WITH S TO SW WINDS INCREASING TODAY...MOST AREAS WITH
THE EXCEPTION OF LOCATIONS CLOSE TO LAKE MICHIGAN AND POSSIBLY THE
KEWEENAW PENINSULA SHOULD HAVE NO PROBLEM REACHING THE LOW/MID 90S
TODAY PER MIXING TO AROUND 800MB ON NAM FCST SOUNDINGS. THESE TEMPS
ARE INLINE WITH WHAT WAS OBSERVED UPSTREAM FROM IA TO THE DAKOTAS
YESTERDAY. IT COULD BE A LITTLE WARMER IF THERE IS LESS CLOUD COVER
AND MIXING HEIGHTS BUILD A BIT HIGHER. RECORD HIGH OF 93 HERE AT THE
OFFICE MAY FALL. AT THIS POINT...EXPECT HOT CONDITIONS RIGHT TO THE
LAKE SUPERIOR SHORE...WITH LOCAL EXCEPTIONS AROUND THE KEWEENAW.
HOWEVER...IF SHRA/TSRA MOVING ACROSS LAKE SUPERIOR PUSH
OUTFLOW/MARINE LAYER S...TEMPS WILL OBVIOUSLY END UP LOWER THAN
CURRENTLY EXPECTED CLOSE TO THE LAKE. AS WAS THE CASE UPSTREAM
YESTERDAY...MIXING SHOULD HELP KEEP DWPTS IN CHECK AND PREVENT
AGGRAVATING THE HEAT WITH HIGHER APPARENT TEMPS. LEANED TOWARD THE
NAM IDEA WITH DWPTS GENERALLY IN THE LOW/MID 60S OVER THE W HALF OR
SO OF UPPER MI. HIGHER DWPTS WILL BE FOUND OVER THE ERN FCST AREA
DOWNWIND OF LAKE MICHIGAN...BUT TEMPS THERE WILL ALSO BE A LITTLE
LWR THAN OVER THE W. AS MIXING HEIGHTS BUILD AND TAP INTO LOW-LEVEL
JET...SHOULD SEE WIND GUSTS TO AROUND 30 MPH OR SO FOR AT LEAST A
FEW HRS THIS AFTN...ESPECIALLY OVER THE W HALF WHERE MIXING HEIGHTS
WILL BE GREATEST.
WEAK LOW PRES WILL CROSS LAKE SUPERIOR TONIGHT WITH COLD FRONT THEN
DROPPING S BEHIND IT. WHILE MANY MODELS THE LAST COUPLE OF DAYS HAD
INDICATED A GOOD AMOUNT OF PCPN MIGHT FALL ASSOCIATED WITH THIS
FROPA...RECENT GUIDANCE NOW INDICATES THE FROPA WILL BE MAINLY DRY.
PART OF THE ISSUE MAY BE THAT THE LOW-LEVEL JET WILL HAVE VEERED
WRLY WITH NOSE WELL OFF TO THE E...LIMITING IMPORTANT NIGHTTIME
FORCING FROM THE LOW-LEVEL JET HERE. IN ANY EVENT...PREVIOUS FCST
IDEA OF SLIGHT CHC/LOW CHC POPS APPEARS ON TRACK FOR NOW. FOG WHICH
COVERED MUCH OF LAKE SUPERIOR YESTERDAY AND IS NOW PUSHING BACK TO
THE N UNDER DEVELOPING SRLY FLOW MAY SWEEP BACK S WITH FROPA
TONIGHT...OR FOG MAY REDEVELOP AS COOLER MARINE LAYER SINKS S AND
ENCOUNTERS HIGHER DWPTS TOWARD SHORE AND IN UPSLOPING INTO UPPER MI.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 546 AM EDT MON JUL 16 2012
THE UPPER GREAT LAKES WILL BEGIN TO LOSE THE INFLUENCE OF THE LARGE
500MB LOW SPINNING ACROSS N QUEBEC...AS IT SLOWLY HEADS OFF INTO THE
ATLANTIC ON THURSDAY. THE SFC LOW SHOULD BE JUST SE OF THE
CWA...STRETCHING FROM N QUEBEC...THROUGH N LAKE HURON...TO S
CENTRAL/SE SD. DRIER CANADIAN HIGH PRESSURE WILL THE BUILD IN BEHIND
THE COLD FRONT. WITH BOOKEND LOWS OVER CANADA AND THE FAR N
U.S...THE 500MB RIDGE SHOULD BE ABLE TO BUILD BACK ACROSS THE
CENTRAL PLAINS BY MID WEEK...AND CONTINUE TO BUILD ACROSS THE UPPER
GREAT LAKES THROUGH AT LEAST SATURDAY.
BOTH 15/12Z RUNS OF THE CANADIAN AND ECMWF DEVELOPED AFTERNOON AND
EARLY EVENING SHOWERS NEAR THE WI BORDER THURSDAY. WILL ADJUST POPS
UP SLIGHTLY IN THIS AREA...BUT WILL FAVOR AN INCREASE IN SKY COVER
INSTEAD OF INCREASING POPS TO ANYTHING ABOVE SLIGHT CHANCE YET...AS
A RELATIVELY WEAK WAVE SLIDES IN ON THE NW FLOW ALOFT.
EXPECT MAINLY NORTHERLY FLOW TO DOMINATE OFF LAKE SUPERIOR...BEFORE
THE SFC HIGH SHIFTS TO OUR E FROM THURSDAY ON. WHILE TEMPERATURES
WILL BE ON THE INCREASE AGAIN TO MORE UNCOMFORTABLE LEVELS ACROSS
THE CENTRAL PLAINS...UPPER MI WILL BE PROTECTED FROM THE HEAT.
THE CANADIAN/ECMWF/ AND GFS ALL HAVE THE 500MB TROUGH OVER THE
PACIFIC NORTHWEST EJECTING NORTHEASTWARD...ATTEMPTING TO ROUND THE
HIGH AMPLITUDE RIDGE ACROSS THE NORTHERN PLAINS AND CENTRAL CANADA.
AS EXPECTED...TIMING OF THIS FEATURE AT 100 PLUS HOURS VARIES
SIGNIFICANTLY. THE 15/12Z CANADIAN WAS THE FASTEST...WITH THE 15/12Z
ECMWF BEING THE SLOWEST /SLOWER THAN THE CANADIAN BY OVER 18 HOURS
BY SATURDAY/. AS A RESULT OF THE DIFFERENCES...WILL RUN CLOSER TO
MODEL CONSENSUS FOR THE UPCOMING WEEKEND. WEEKEND TEMPS SHOULD
SLOWLY CLIMB BACK INTO THE UPPER 80S AND LOW 90S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON JUL 16 2012
FOG/VLIFR CONDITIONS SETTLED INTO KCMX OVERNIGHT. FOG SHOULD LIFT IN
THE NEXT COUPLE OF HRS WITH A RETURN TO VFR. ATTENTION THEN TURNS TO
SHRA/TSRA ASSOCIATED WITH LOW-LEVEL JET TO THE W IN MN. THERE IS
UNCERTAINTY IN HOW MUCH OF THIS PCPN WILL HOLD TOGETHER AS IT SHIFTS
E...BUT RIGHT NOW TRENDS/LATEST MODEL GUIDANCE SUGGEST AT LEAST A
VCNTY SHRA MENTION IS WARRANTED FOR THIS MORNING AT KCMX. PCPN
SHOULD STAY N OF KIWD/KSAW WITH VFR CONDITIONS THE RULE. AS
LOW-LEVEL JET SHIFTS ACROSS THE AREA TODAY...BUILDING MIXING HEIGHTS
WILL TAP STRONGER WINDS LEADING TO S TO SW WINDS GUSTING 20-30KT...
PARTICULARLY AT KIWD/KSAW. COLD FRONT WILL DROP S ACROSS THE AREA
TONIGHT. SINCE FOG HAS BEEN PRESENT OVER LAKE SUPERIOR...WIND SHIFT
TO THE N SHOULD BRING IFR/POTENTIAL LIFR CONDITIONS TO ALL SITES
AFTER FROPA TONIGHT. VERY LOW CONFIDENCE IN ANY PCPN ACCOMPANYING
FRONT...SO PCPN WAS NOT MENTIONED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 546 AM EDT MON JUL 16 2012
MAIN FCST ISSUE IS MARINE FOG. AS OPPOSED TO 24HRS AGO WHEN
SATELLITE IMAGERY PROVIDED A GOOD VIEW OF FOG/STRATUS OVER THE
LAKE...MID/HIGH CLOUDS ARE OBSCURING THE FOG THIS MORNING. SO...WILL
ASSUME THAT WITH DEVELOPING SRLY FLOW THE FOG IS ADVECTING N ACROSS
THE LAKE WITH VIS IMPROVING FROM THE S. HAVE THUS OPTED TO LET DENSE
FOG ADVY EXPIRE AS SCHEDULED AT 10Z. AS COLD FRONT DROPS ACROSS LAKE
SUPERIOR TONIGHT...FOG MAY AGAIN BECOME AN ISSUE AT LEAST FOR A
TIME...ESPECIALLY IF MORE RAINFALL OCCURS ACROSS THE LAKE. AS DRIER
AIR BEGINS TO MAKE INROADS LATE TONIGHT/TUE...EXPECT FOG TO FINALLY
DISSIPATE.
AS FOR WINDS...LOCALLY GUSTY S-SW WINDS OF 20-25KT WILL BE POSSIBLE
AT TIMES IN THE NEARSHORE AREAS OF SRN LAKE SUPERIOR TODAY AS
SOUTHERLY WINDS INCREASE AHEAD OF APPROACHING LOW PRES. ALSO...A
PERIOD OF STRONGER WINDS POTENTIALLY UPWARDS OF 25KT OR SO MAY OCCUR
IN THE VCNTY OF THE COLD FRONT DROPPING ACROSS THE LAKE LATE THIS
AFTN AND THIS EVENING. OTHERWISE...WINDS SHOULD BE MOSTLY UNDER
20KT. WITH HIGH PRES DOMINATING WED-FRI...WINDS WILL LIKELY BE UNDER
15KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
548 AM EDT MON JUL 16 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EDT MON JUL 16 2012
MAIN FCST CONCERNS IN THE SHORT TERM WILL BE THE HOT WEATHER TODAY
AND WHETHER OR NOT ANY CONVECTION DEVELOPS TODAY/TONIGHT. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE FAR WRN CONUS
WITH A BROAD RIDGE DOWNSTREAM ACROSS THE CNTRL CONUS. AS
EXPECTED...SHORTWAVE ENERGY RIDING AROUND THE RIDGE IS CURRENTLY
SUPPORTING SHRA/TSRA ACROSS SRN MANITOBA INTO NRN MN AND ADJACENT
NRN ONTARIO. IN RESPONSE TO THE SHORTWAVE ENERGY...A STRONG
LOW-LEVEL JET (50-60KT PER LATEST RUC ANALYSIS) IS ALIGNED FROM
NCNTRL NEBRASKA TO NW MN AND IS THE MAIN DRIVER FOR THE CONVECTION.
THE LOW-LEVEL JET WILL VEER AND TRANSLATE ACROSS THE UPPER LAKES
TODAY. AS HAS BEEN THE CASE OVER THE LAST COUPLE OF DAYS...THE GFS
CONTINUES TO BE FARTHER S WITH THE NOSE OF THE LOW-LEVEL JET
COMPARED TO OTHER GUIDANCE...RESULTING IN MORE WIDESPREAD PCPN
ACROSS THE FCST AREA TODAY. GIVEN THE OVERWHELMING CONSENSUS OF
OTHER MODEL GUIDANCE...WILL LEAN AWAY FROM THE GFS SCENARIO TODAY.
THUS...EXPECT MAIN AREA OF SHRA/TSRA TO SLIDE ACROSS NRN LAKE
SUPERIOR/NRN ONTARIO WHERE LOW-LEVEL JET RIDING OVERTOP MARINE LAYER
WILL CONTINUE TO YIELD RATHER STRONG FORCING. THAT SAID...AS IS
CURRENTLY OCCURRING TO THE W...CAN`T RULE OUT ISOLD/SCT SHRA/TSRA
ACROSS MAINLY NRN UPPER MI AND THE KEWEENAW IN PARTICULAR AS THE
AXIS OF THE LOW-LEVEL JET TRANSLATES ACROSS THE AREA. IF STRONGER
CONVECTION PASSES OVER LAKE SUPERIOR TODAY...OUTFLOW ENHANCED BY THE
MARINE LAYER COULD SET UP A SHARP SFC BOUNDARY THAT PUSHES S INTO
NRN UPPER MI. THAT COULD THEN BECOME A FOCUS FOR CONVECTIVE
DEVELOPMENT THIS AFTN. WILL BE SOMETHING TO MONITOR DURING THE DAY.
WITH 1000-1500J/KG OF MLCAPE PER NAM (GFS IS OVERLY MOIST IN THE
LOW-LEVELS) AND 35-45KT OF DEEP LAYER SHEAR...ISOLD SVR WX IS
POSSIBLE IF STORMS DO OCCUR TODAY.
AS FOR TEMPS...WITH S TO SW WINDS INCREASING TODAY...MOST AREAS WITH
THE EXCEPTION OF LOCATIONS CLOSE TO LAKE MICHIGAN AND POSSIBLY THE
KEWEENAW PENINSULA SHOULD HAVE NO PROBLEM REACHING THE LOW/MID 90S
TODAY PER MIXING TO AROUND 800MB ON NAM FCST SOUNDINGS. THESE TEMPS
ARE INLINE WITH WHAT WAS OBSERVED UPSTREAM FROM IA TO THE DAKOTAS
YESTERDAY. IT COULD BE A LITTLE WARMER IF THERE IS LESS CLOUD COVER
AND MIXING HEIGHTS BUILD A BIT HIGHER. RECORD HIGH OF 93 HERE AT THE
OFFICE MAY FALL. AT THIS POINT...EXPECT HOT CONDITIONS RIGHT TO THE
LAKE SUPERIOR SHORE...WITH LOCAL EXCEPTIONS AROUND THE KEWEENAW.
HOWEVER...IF SHRA/TSRA MOVING ACROSS LAKE SUPERIOR PUSH
OUTFLOW/MARINE LAYER S...TEMPS WILL OBVIOUSLY END UP LOWER THAN
CURRENTLY EXPECTED CLOSE TO THE LAKE. AS WAS THE CASE UPSTREAM
YESTERDAY...MIXING SHOULD HELP KEEP DWPTS IN CHECK AND PREVENT
AGGRAVATING THE HEAT WITH HIGHER APPARENT TEMPS. LEANED TOWARD THE
NAM IDEA WITH DWPTS GENERALLY IN THE LOW/MID 60S OVER THE W HALF OR
SO OF UPPER MI. HIGHER DWPTS WILL BE FOUND OVER THE ERN FCST AREA
DOWNWIND OF LAKE MICHIGAN...BUT TEMPS THERE WILL ALSO BE A LITTLE
LWR THAN OVER THE W. AS MIXING HEIGHTS BUILD AND TAP INTO LOW-LEVEL
JET...SHOULD SEE WIND GUSTS TO AROUND 30 MPH OR SO FOR AT LEAST A
FEW HRS THIS AFTN...ESPECIALLY OVER THE W HALF WHERE MIXING HEIGHTS
WILL BE GREATEST.
WEAK LOW PRES WILL CROSS LAKE SUPERIOR TONIGHT WITH COLD FRONT THEN
DROPPING S BEHIND IT. WHILE MANY MODELS THE LAST COUPLE OF DAYS HAD
INDICATED A GOOD AMOUNT OF PCPN MIGHT FALL ASSOCIATED WITH THIS
FROPA...RECENT GUIDANCE NOW INDICATES THE FROPA WILL BE MAINLY DRY.
PART OF THE ISSUE MAY BE THAT THE LOW-LEVEL JET WILL HAVE VEERED
WRLY WITH NOSE WELL OFF TO THE E...LIMITING IMPORTANT NIGHTTIME
FORCING FROM THE LOW-LEVEL JET HERE. IN ANY EVENT...PREVIOUS FCST
IDEA OF SLIGHT CHC/LOW CHC POPS APPEARS ON TRACK FOR NOW. FOG WHICH
COVERED MUCH OF LAKE SUPERIOR YESTERDAY AND IS NOW PUSHING BACK TO
THE N UNDER DEVELOPING SRLY FLOW MAY SWEEP BACK S WITH FROPA
TONIGHT...OR FOG MAY REDEVELOP AS COOLER MARINE LAYER SINKS S AND
ENCOUNTERS HIGHER DWPTS TOWARD SHORE AND IN UPSLOPING INTO UPPER MI.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 546 AM EDT MON JUL 16 2012
THE UPPER GREAT LAKES WILL BEGIN TO LOSE THE INFLUENCE OF THE LARGE
500MB LOW SPINNING ACROSS N QUEBEC...AS IT SLOWLY HEADS OFF INTO THE
ATLANTIC ON THURSDAY. THE SFC LOW SHOULD BE JUST SE OF THE
CWA...STRETCHING FROM N QUEBEC...THROUGH N LAKE HURON...TO S
CENTRAL/SE SD. DRIER CANADIAN HIGH PRESSURE WILL THE BUILD IN BEHIND
THE COLD FRONT. WITH BOOKEND LOWS OVER CANADA AND THE FAR N
U.S...THE 500MB RIDGE SHOULD BE ABLE TO BUILD BACK ACROSS THE
CENTRAL PLAINS BY MID WEEK...AND CONTINUE TO BUILD ACROSS THE UPPER
GREAT LAKES THROUGH AT LEAST SATURDAY.
BOTH 15/12Z RUNS OF THE CANADIAN AND ECMWF DEVELOPED AFTERNOON AND
EARLY EVENING SHOWERS NEAR THE WI BORDER THURSDAY. WILL ADJUST POPS
UP SLIGHTLY IN THIS AREA...BUT WILL FAVOR AN INCREASE IN SKY COVER
INSTEAD OF INCREASING POPS TO ANYTHING ABOVE SLIGHT CHANCE YET...AS
A RELATIVELY WEAK WAVE SLIDES IN ON THE NW FLOW ALOFT.
EXPECT MAINLY NORTHERLY FLOW TO DOMINATE OFF LAKE SUPERIOR...BEFORE
THE SFC HIGH SHIFTS TO OUR E FROM THURSDAY ON. WHILE TEMPERATURES
WILL BE ON THE INCREASE AGAIN TO MORE UNCOMFORTABLE LEVELS ACROSS
THE CENTRAL PLAINS...UPPER MI WILL BE PROTECTED FROM THE HEAT.
THE CANADIAN/ECMWF/ AND GFS ALL HAVE THE 500MB TROUGH OVER THE
PACIFIC NORTHWEST EJECTING NORTHEASTWARD...ATTEMPTING TO ROUND THE
HIGH AMPLITUDE RIDGE ACROSS THE NORTHERN PLAINS AND CENTRAL CANADA.
AS EXPECTED...TIMING OF THIS FEATURE AT 100 PLUS HOURS VARIES
SIGNIFICANTLY. THE 15/12Z CANADIAN WAS THE FASTEST...WITH THE 15/12Z
ECMWF BEING THE SLOWEST /SLOWER THAN THE CANADIAN BY OVER 18 HOURS
BY SATURDAY/. AS A RESULT OF THE DIFFERENCES...WILL RUN CLOSER TO
MODEL CONSENSUS FOR THE UPCOMING WEEKEND. WEEKEND TEMPS SHOULD
SLOWLY CLIMB BACK INTO THE UPPER 80S AND LOW 90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 137 AM EDT MON JUL 16 2012
MAINLY VFR CONDITIONS THROUGH THE PERIOD...AS THE DEVELOPING WARM
FRONT TONIGHT IS EXPECTED TO STAY TO THE N OF THE AREA.
HAVE SOME CONCERN WITH FOG/STRATUS OVER LK SUPERIOR AND IT/S
POSSIBLE EFFECT ON KCMX/KIWD. CURRENT THINKING CONTINUES TO BE THAT
IT SHOULD NOT AFFECT KIWD DUE TO INCREASING SWRLY FLOW OVERNIGHT. KCMX
IS TRICKY. WITH WINDS BECOMING ERLY OVERNIGHT...COULD SEE THE
FOG/STRATUS OVER LK SUPERIOR MOVE IN AND QUICKLY BRING CIGS/VSBYS
DOWN. INDICATIONS ARE THAT IT IS A STRATUS DECK...BUT THE LIGHT
UPSLOPE FLOW WOULD HELP VSBYS GO DOWN. DO NOT HAVE ENOUGH CONFIDENCE
TO HIT THE LOW CLOUDS/VSBYS HARD...SO WILL MENTION MVFR VSBY AND
SCT003 FOR NOW. MID AND HIGH CLOUDS MIGHT PREVENT THIS FROM HAPPENING
OVERNIGHT THOUGH...BUT CONFIDENCE CONTINUES TO BE LOW WITH THIS SITE
FINALLY...WINDS COULD GET QUITE GUSTY...TO 35KTS...OUT OF THE SSW IN
THE AFTERNOON AND PUT THIS INTO ALL TAFS WITH GUSTY WINDS TO 30 KTS.
BY EVENING...A COLD FRONT WILL BE MOVING THROUGH THE AREA AND WINDS
WILL COME DOWN AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 546 AM EDT MON JUL 16 2012
MAIN FCST ISSUE IS MARINE FOG. AS OPPOSED TO 24HRS AGO WHEN
SATELLITE IMAGERY PROVIDED A GOOD VIEW OF FOG/STRATUS OVER THE
LAKE...MID/HIGH CLOUDS ARE OBSCURING THE FOG THIS MORNING. SO...WILL
ASSUME THAT WITH DEVELOPING SRLY FLOW THE FOG IS ADVECTING N ACROSS
THE LAKE WITH VIS IMPROVING FROM THE S. HAVE THUS OPTED TO LET DENSE
FOG ADVY EXPIRE AS SCHEDULED AT 10Z. AS COLD FRONT DROPS ACROSS LAKE
SUPERIOR TONIGHT...FOG MAY AGAIN BECOME AN ISSUE AT LEAST FOR A
TIME...ESPECIALLY IF MORE RAINFALL OCCURS ACROSS THE LAKE. AS DRIER
AIR BEGINS TO MAKE INROADS LATE TONIGHT/TUE...EXPECT FOG TO FINALLY
DISSIPATE.
AS FOR WINDS...LOCALLY GUSTY S-SW WINDS OF 20-25KT WILL BE POSSIBLE
AT TIMES IN THE NEARSHORE AREAS OF SRN LAKE SUPERIOR TODAY AS
SOUTHERLY WINDS INCREASE AHEAD OF APPROACHING LOW PRES. ALSO...A
PERIOD OF STRONGER WINDS POTENTIALLY UPWARDS OF 25KT OR SO MAY OCCUR
IN THE VCNTY OF THE COLD FRONT DROPPING ACROSS THE LAKE LATE THIS
AFTN AND THIS EVENING. OTHERWISE...WINDS SHOULD BE MOSTLY UNDER
20KT. WITH HIGH PRES DOMINATING WED-FRI...WINDS WILL LIKELY BE UNDER
15KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR LSZ244-
245-263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1137 AM CDT MON JUL 16 2012
.UPDATE...
SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP WITHIN THE NEXT HOUR
OR TWO OVER SOUTHERN AND CENTRAL MISSOURI. HAVE DECIDED TO
INCREASE POPS UP TO 30 PERCENT.
12Z RAOB FROM SPRINGFIELD MEASURED A TROPICAL AIRMASS...WITH
PRECIPITABLE WATER AT 1.67 INCHES. THIS IS A SWEET SPOT FOR A
DECENT FREQUENCY OF AFTERNOON PULSE THUNDERSTORMS FOR SOUTHERN AND
CENTRAL MISSOURI.
MIXED LAYER CAPES ARE NOW EXCEEDING 1500 J/KG ACROSS MOST OF THE
REGION. SATELLITE SHOWS A DENSE AGITATED FIELD OF CUMULUS...WITH
UPDRAFTS LIKELY TO EXCEED THE LEVEL OF FREE CONVECTION SOON.
THERE ARE A COUPLE OF FACTORS THAT COULD AFFECT THE STRENGTH OF
TODAYS STORMS. LAPSE RATES ARE FAIRLY LOW DUE TO WARM MID LEVEL
TEMPERATURES. MEANWHILE...UPPER LEVEL SUPPRESSION IS ONGOING AS
THE SUMMERTIME RIDGE OF HIGH PRESSURE HOVERS CLOSER TO SOUTHERN
MISSOURI.
WE STILL BELIEVE THAT STRONG STORMS ARE STILL POSSIBLE WITHIN
THIS ENVIRONMENT..AS THE RAP NOW ANALYZES THETA E DIFFERENTIALS
EXCEEDING 30 DEGREES K. WILL BE MONITORING RADAR CLOSELY THROUGH
THE AFTERNOON.
CRAMER
&&
.AVIATION...
PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL
NEED TO MONITOR RADAR TRENDS THROUGH THIS AFTERNOON AND EVENING.
SCATTERED THUNDERSTORMS ARE LIKELY...AS A TROPICAL LIKE AIRMASS
NOW EXISTS OVER THE REGION.
A FEW DOWNBURSTS CAN NOT BE RULED OUT WITH SOME OF THE STRONGER
STORMS.
OTHERWISE...A FIELD OF CUMULUS CLOUDS HAS DEVELOPED AROUND 3000
FEET. THESE CEILINGS WILL LIKELY RISE THROUGH THE AFTERNOON AS
TEMPERATURES WARM INTO THE 90S.
WINDS WILL BE LIGHT AND MOSTLY FROM THE SOUTH TO SOUTHWEST THROUGH
THE AFTERNOON...BECOMING LIGHT AND VARIABLE LATER TONIGHT.
STORMS WILL DISSIPATE THROUGH THE EVENING HOURS...LEAVING FAIR
WEATHER CONDITIONS TONIGHT AND TOMORROW MORNING.
CRAMER
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
754 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL DROP SOUTH ACROSS THE AREA TONIGHT AND
BRING SCATTERED SHOWERS AND THUNDERSTORMS. BEHIND THE FRONT...
CANADIAN HIGH PRESSURE WILL BRING A WELCOME CHANGE TO COOLER
CONDITIONS WEDNESDAY THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
A COLD FRONT DROPPING SOUTHWARD FROM CANADA IS MOVING ACROSS LAKE
ONTARIO THIS EVENING...WITH THE BOUNDARY FORECAST TO DROP
SOUTHWARD ACROSS WESTERN NEW YORK LATE THIS EVENING AND OVERNIGHT.
THUS FAR...SHOWERS AND THUNDERSTORMS HAVE BEEN SCATTERED IN
NATURE...AND MAINLY CONFINED EAST OF LAKE ONTARIO. THIS
SAID...STORMS WHICH HAVE DEVELOPED HAVE BEEN QUITE STRONG. EXPECT
THE LOSS OF DAYTIME HEATING...AND A WEAKENING WIND FIELD ALOFT
WILL DIMINISH THE SEVERE WEATHER POTENTIAL WITH TIME...HOWEVER
STORMS STILL BEAR WATCHING THIS EVENING...ESPECIALLY EAST OF LAKE
ONTARIO.
OTHERWISE...THE BIG QUESTION IS WILL BUFFALO...ROCHESTER...AND THE
REST OF WESTERN NEW YORK RECEIVE ANY RAIN WITH THIS FRONT. AT THIS
TIME...CHANCES APPEAR TO BE DIMINISHING...AS THERE IS LIMITED
SHOWERS ALONG THE FRONT EARLY THIS EVENING. EVEN STILL...MOST
MODEL GUIDANCE (NAM/GFS/RGEM) AND THE HRRR ALL SUGGEST SOME RE-
DEVELOPMENT OF SHOWERS SOUTH OF LAKE ONTARIO THIS EVENING. BUT THE
HRRR ALSO INDICATES THIS WILL LIKELY BE SCATTERED IN NATURE AS
WELL...SO MANY LOCATIONS STILL MAY MISS OUT ON ANY MEASURABLE RAINFALL.
OTHERWISE...WARM AND RATHER HUMID CONDITIONS WILL BE THE RULE TONIGHT WITH MANY
LOCATIONS ACROSS THE LAKE PLAINS EXPECT TO STAY ABOVE 70 DEGREES.
ON WEDNESDAY...THE COLD FRONT IS FORECAST TO STALL SOUTH OF THE NEW
YORK/PA BORDER WHILE A WEAK WAVE MOVES EAST ALONG THE BOUNDARY.
A MOIST NORTHERLY FLOW LINGERING BEHIND THE FRONT...COMBINED WITH
ADDITIONAL LIFT FROM A PASSING UPPER LEVEL JET STREAK...COULD STILL
STILL RESULT IN A FEW MORE SHOWERS AND POSSIBLE THUNDERSTORMS FOR
AREAS MAINLY SOUTH OF THE THRUWAY. WILL MAINTAIN THE HIGHEST POPS
ACROSS THE SOUTHERN TIER WHICH WILL BE CLOSER TO DEEPER LOW LEVEL
MOISTURE AND FAVORABLE INSTABILITY.
THE INCREASED CLOUD COVER AND LINGERING CHANCES FOR PCPN WILL BRING
WELCOME RELIEF FROM THIS AFTERNOON`S OPPRESSIVE CONDITIONS. EXPECT
TEMPERATURES TO RANGE FROM THE UPPER 70S TO THE MID 80S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
WEDNESDAY NIGHT THE SLOW SOUTHWARD PUSH TO THE COLD FRONT WILL
LIKELY START THIS PERIOD WITH THE COLD FRONT DRAPED JUST TO THE
SOUTH OF THE STATE BORDER. AN ANAFRONTAL STRUCTURE WILL LEAD TO A
FEW SHOWERS AND PERHAPS A RUMBLE OF THUNDER LINGERING ACROSS THE
SOUTHERN TIER THROUGH THE EVENING HOURS. AS COOLER AIR ADVECTS
SOUTHWARD ACROSS THE EASTERN GREAT LAKES A MORE COMFORTABLE NIGHT
WILL BE HAD ACROSS THE NORTH COUNTRY AND AREAS JUST SOUTH OF THE
LAKE ONTARIO SHORELINE ALONG WITH LOWERING DEW POINTS. SOME PATCHY
FOG AND LOW CLOUDS ARE POSSIBLE ACROSS THE SOUTHERN TWO TIERS OF
COUNTIES BEHIND THE COLD FRONT WEDNESDAY NIGHT WHERE DEWPOINTS WILL
BE SLOW TO FALL.
THURSDAY HIGH PRESSURE WILL PUSH SOUTHWARD FROM NEAR JAMES BAY
BRINGING A COMFORTABLE DAY WITH MOSTLY SUNNY SKIES TO THE
NORTH...WHILE TO THE SOUTH WHERE LOW LEVEL MOISTURE WILL LINGER A
PARTLY SUNNY SKY IS LIKELY. TEMPERATURES AT 850 HPA AVERAGE 10 TO
14C ACROSS THE AREA WHICH WILL PROMOTE AFTERNOON HIGHS IN THE UPPER
70S TO AROUND 80. THOUGH THESE TEMPERATURES ARE ONLY A FEW DEGREES
COOLER THAN WEDNESDAY...THE DRIER AIR WITH DEWPOINTS ABOUT 10
DEGREES LOWER WILL MAKE FOR A COMFORTABLE DAY.
THURSDAY NIGHT A COMPLEX OF THUNDERSTORMS IS EXPECTED TO FORM
UPSTREAM OVER THE WESTERN GREAT LAKES. THE AXIS OF THETA-E ALONG
WITH THE SE ORIENTATION OF 1000-500 THICKNESS LINES SUGGEST THAT
THESE THUNDERSTORMS SHOULD DIVE SOUTHEASTWARD AND REMAIN JUST TO THE
WEST AND SOUTH OF THE SOUTHERN TIER. WILL CONTINUE A DRY FORECAST
THOUGH SOME MID AND HIGH LEVEL CLOUDS MAY STREAM ACROSS PORTIONS OF
WESTERN NEW YORK. OTHERWISE EXPECT A MAINLY CLEAR SKY THURSDAY NIGHT
ALLOWING FOR TEMPERATURES TO DROP BACK INTO THE LOWER 50S ACROSS THE
INLAND SOUTHERN TIER AND NORTH COUNTRY...TO AROUND 60 CLOSER TO THE
LAKES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THIS TIME PERIOD WILL LARGELY BE DRY...THOUGH A WEAK FRONTAL
BOUNDARY COULD BRING SOME SPOTTY SHOWERS AND THUNDERSTORMS TOWARDS
THE END OF THE WEEKEND/BEGINNING OF THE WORK WEEK. TEMPERATURES WILL
AVERAGE AROUND NORMAL FOR THE TIME PERIOD AND NO EXTREME HEAT
EXPECTED.
THE LARGE SCALE PATTERN FOR THIS TIME PERIOD PLACES A BROAD RIDGE OF
HIGH PRESSURE OVER THE CENTRAL US/ROCKIES WITH SHORT WAVE TROUGHS
ROUNDING THE RIDGE AND CROSSING THE EASTERN GREAT LAKES THROUGH THE
PERIOD.
FOR FRIDAY A GENERAL TROUGH WILL BE ACROSS NEW ENGLAND AND THE
EASTERN GREAT LAKES REGION. MOISTURE IS MARGINAL AND WITH PLENTY OF
DRY AIR IN THE LOW TO MID LEVELS BELOW THIS MOISTURE WILL MAINTAIN
THE DRY FORECAST WITH A MIX OF SUN AND CLOUDS. WITH THIS NORTHERLY
FLOW EXPECT AFTERNOON TEMPERATURES TO REMAIN BELOW NORMAL...WITH
COMFORTABLE SUMMER HIGHS IN THE MID TO UPPER 70S.
ON SATURDAY BOTH THE 12Z ECMWF AND GFS BRING A RIDGE ALOFT ACROSS
THE REGION BEHIND A SHORT WAVE THAT IS EXITING ACROSS NEW ENGLAND
AND OVER THE WESTERN ATLANTIC. WITH AMPLE DRY AIR EXPECT MOSTLY
SUNNY SKIES AND AFTERNOON TEMPERATURES SEVERAL DEGREES WARMER. AIR
TEMPERATURES OF LOW TO MID 80S WILL BE COMMON...AND THOUGH DEW
POINTS WILL BE RISING MOST AREAS SHOULD STAY BELOW 60...SO WE SHOULD
STILL REMAIN COMFORTABLE.
ON SUNDAY BOTH THE ECMWF AND GFS BRING THE CREST OF WARMTH ALOFT
ACROSS THE REGION WITH 850 HPA TEMPERATURES REACHING +15 TO +18C.
BEHIND THE UPPER LEVEL RIDGE CLOUDS WILL LIKELY INCREASE SOME AS
WELL...LEAVING TEMPERATURES SUNDAY SIMILAR TO SATURDAY. AN UPPER
LEVEL SHORT WAVE ACROSS SOUTHERN CANADA WILL CLIP/NEAR THE NORTH
COUNTRY SUNDAY WITH A SLIGHT CHANCE FOR A SHOWER OR ISOLATED
THUNDERSTORMS. THOUGH TEMPERATURES SUNDAY WILL BE SIMILAR TO
SATURDAY THE DEW POINT WILL BE HIGHER...WITH A MORE NOTICEABLE FEEL
OF HUMIDITY TO THE AIR. DEW POINTS WILL LIKELY CLIMB INTO THE 60S ON
SUNDAY.
ON MONDAY BOTH THE ECMWF AND GFS BRING A WEAK FRONTAL BOUNDARY
ACROSS THE REGION FROM THE NORTHERN GREAT LAKES. WITH THE BUILDING
MOISTURE AHEAD OF THIS FRONT A SHOWER OR THUNDERSTORM IS POSSIBLE
LATE SUNDAY NIGHT AND INTO MONDAY. GIVEN OUR DRY SPELL AND THE
WEAKNESS OF THIS FRONTAL BOUNDARY WILL JUST GO WITH LOW CHC POPS.
SOUTHWESTERLY WINDS AHEAD OF THIS FRONTAL BOUNDARY WILL MAINTAIN
SLIGHTLY WARMER THAN NORMAL TEMPERATURES FOR OUR REGION WITH
AFTERNOON HIGHS IN THE 80S
TUESDAY BOTH THE GFS AND ECMWF BRING DRIER AIR ACROSS THE REGION
WITH HIGH PRESSURE FOLLOWING THE WEAK FRONTAL BOUNDARY. SLIGHTLY
COOLER...BUT MORE NOTICEABLE LOWER DEWPOINTS ON TUESDAY WITH A
RETURN TO PLENTY OF SUNSHINE.
OVERNIGHT LOWS WILL GENERALLY FALL BACK INTO THE 60S...WITH THE
WARMEST NIGHT LIKELY SUNDAY NIGHT AHEAD OF THE WEAK COLD FRONT...AND
COOLEST MORNINGS FRIDAY AND SATURDAY WITH MAINLY CLEAR SKIES...LOW
DEW POINTS AND LIGHT WINDS.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR CONDITIONS THIS EVENING AS A COLD FRONT DROPS
FROM NORTH TO SOUTH...AND ACROSS THE REGION TODAY. THUNDERSTORMS
WILL LIKELY BE QUITE SCATTERED IN NATURE...BUT IF ONE DOES HAPPEN
TO CROSS A TAF SITE IT WOULD LIKELY RESULT IN A BRIEF BUT ABRUPT
LOWERING OF CONDITIONS.
WINDS WILL SHIFT BEHIND THIS FRONT LATER TONIGHT...DIMINISHING THE
CHANCE FOR ANY RAIN. HOWEVER...THERE STILL WILL BE SOME MOISTURE
IN THE BOUNDARY LAYER...AND WHILE DRIER AIR WILL BUILD IN...THERE
WILL BE A LIMITED POTENTIAL FOR FOG TONIGHT AT SOME LOCATIONS.
AFTER THIS...EXPECT MAINLY VFR CONDITIONS NORTH OF I-90 AT
BUF/IAG/ROC/ART. AFTERNOON SHOWERS AND THUNDERSTORMS MAY DEVELOP
AT JHW...NEAR WHERE THE BOUNDARY WILL BE STALLED.
OUTLOOK...
THURSDAY THROUGH SUNDAY...MAINLY VFR.
&&
.MARINE...
LOW PRESSURE TRACKING ACROSS THE ST LAWRENCE RIVER WILL MOVE TO THE
EAST AND DRAG A COLD FRONT SOUTH ACROSS THE LOWER LAKES TONIGHT. THE
TIGHT PRESSURE GRADIENT SOUTH OF THE FRONT WILL RESULT IN SCA
CONDITIONS THROUGH THE EVENING. SCATTERED SHOWERS AND THUNDERSTORMS
WILL ALSO ACCOMPANY THE FRONT THIS EVENING AND TONIGHT.
HIGH PRESSURE FOLLOWING THE DEPARTING COLD FRONT WILL RESULT IN
CALMER CONDITIONS WEDNESDAY THROUGH FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
LOZ044-045.
&&
$$
SYNOPSIS...TJP
NEAR TERM...APFFEL/TJP
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...APFFEL
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
514 PM EDT MON JUL 16 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND WESTWARD ACROSS THE AREA
THROUGH THE MIDDLE OF THE WEEK. A COLD FRONT WILL APPROACH FROM
THE NORTH LATE IN THE WEEK AND COULD LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 500 PM MONDAY...NO CHANGES IN SYNOPTIC OR MESOSCALE FORECAST
REASONING...JUST ISSUED A REACTIVE UPDATE TO TRACK THE HEAVIEST
CONCENTRATION OF SHOWERS AND THUNDERSTORMS AND HIGHLIGHT THOSE AREAS
WITH 60-80 PERCENT POPS FOR THE NEXT FEW HOURS. HRRR MODEL SHOWS
ACTIVITY PREFERENTIALLY BUILDING SOUTHWEST INTO THE AREA SOUTH OF
FLORENCE AND WEST OF THE SEABREEZE BOUNDARY SHORTLY. PREVIOUS
DISCUSSION FROM 200 PM FOLLOWS...
THE APPROACH OF A RATHER POTENT MID-LEVEL SHORTWAVE TROUGH HAS
HELPED TO INCREASE THE COVERAGE OF SHOWERS AND THUNDERSTORMS ALONG
THE DEVELOPING PIEDMONT TROUGH THIS AFTERNOON. THIS ACTIVITY HAS
SLOWLY SAGGED INTO THE NORTHERN PEE DEE REGION AND WILL MOVE INTO
THE I-95 CORRIDOR BY 3-4 PM. POPS HAVE BEEN RAISED TO LIKELY ACROSS
THIS REGION. SOME OF THE HIGH RESOLUTION NEAR-TERM MODELS ARE
INDICATING THE CONVECTION WILL EXPAND/MOVE ALL THE WAY TO THE COAST
BY THIS EVE. THIS IS NOT IMPOSSIBLE...SHOULD A LARGE ENOUGH COLD
POOL DEVELOP WHICH WOULD HELP TO DRIVE CONVECTION ALL THE WAY TO THE
COAST. HOWEVER...THIS IS NOT THE PREFERRED SOLUTION AT THIS TIME.
FOR NOW...WILL INCLUDE MID CHANCE/GOOD CHANCE POPS AS FAR EAST AS
THE SLOWLY INLAND PROPAGATING SEABREEZE. LOWEST POPS WILL BE
FORECAST ON THE MARINE SIDE OF THE SEABREEZE WHERE LIFT AND
INSTABILITY WILL BE LEAST.
THE MAIN RISK WILL CONTINUE TO BE TORRENTIAL DOWNPOURS...ESPECIALLY
WHERE SLOW MOVING THUNDERSTORMS TRAIN GIVEN VERY WEAK/ALMOST NON-
EXISTENT STEERING FLOW. THUNDERSTORMS WILL ALSO CONTAIN FREQUENT
LIGHTNING. WHERE THUNDERSTORMS ORGANIZE...PONDING OF WATER IN
LOW-LYING AND POOR DRAINAGE AREAS IS EXPECTED AS RAINFALL AMOUNTS
REACH OR EXCEED 2 INCHES. DOWNDRAFT CAPE VALUES ARE NOT PARTICULARLY
IMPRESSIVE...BUT PRECIPITATION LOADING MAY RESULT IN A
WET-MICROBURST OR TWO...CAPABLE OF STRONG TO POSSIBLY DAMAGING
WINDS. SMALL SIZE HAIL IS A REMOTE POSSIBILITY IN THE STRONGEST
STORMS.
THUNDERSTORMS ARE EXPECTED TO DIMINISH WITH LOSS OF HEATING AND AS
MID-LEVEL SHORTWAVE TROUGH LIFTS OUT...POPS WILL DROP SMARTLY AFTER
DARK. HOWEVER...MAY SEE ISOLATED LATE NIGHT SHOWERS/THUNDER
REDEVELOP ALONG THE COASTAL LAND BREEZE.
LOWS TONIGHT WILL BE IN THE LOWER TO MID 70S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 140 PM MONDAY...UPPER RIDGING GRADUALLY STRENGTHENS OVERHEAD
DURING THE PERIOD...BUT SUBTLE WEAKNESSES AND UPPER IMPULSES WILL
CONTINUE SHOWER/THUNDERSTORM CHANCES EACH DAY.
INTERESTING UPPER LOW EASILY VISIBLE ON WV IMAGERY TODAY WILL MOVE
WESTWARD INTO FL/GA AT THE BEGINNING OF THE PERIOD BEFORE DRIFTING
NORTHEAST AND WEAKENING THROUGH WEDNESDAY. EVEN AS UPPER RIDGE
BUILDS EAST FROM THE PLAINS STATES...THIS UPPER LOW WILL KEEP
RELATIVELY LOWER HEIGHTS ACROSS THE SOUTHEAST AND HENCE UPPER
RIDGING WILL NOT HAVE THE CONVECTION-SQUELCHING EFFECT IT USUALLY
DOES. AT THE SURFACE...BERMUDA HIGH PRESSURE WILL SIT OFFSHORE WHILE
THERMAL PIEDMONT TROUGH DEVELOPS AND STRENGTHENS EACH DAY. THESE
TOGETHER KEEP THE CAROLINAS IN A LOW-LEVEL SW RETURN FLOW REGIME
WHICH WILL TRANSPORT WARMTH AND MOISTURE INTO THE AREA. THIS ALL
TOGETHER MEANS WARMING TEMPS AND DECENT AFTN CONVECTION CHANCES EACH
DAY DURING THE SHORT TERM.
MORE SPECIFICALLY...DIURNAL CONVECTION TUESDAY LOOKS RATHER
LIKELY...ESPECIALLY ACROSS SOUTHERN ZONES WHICH WILL BE CLOSER TO
THE UPPER COLD POOL. GUIDANCE SHOWS SUBTLE THICKNESS INCREASE FROM
THE NORTH TUESDAY AS RIDGE BUILDS EAST...AND THIS COULD LIMIT
DIURNAL ACTIVITY...BUT SBCAPE OF NEAR 2000 J/KG AND TEMPS RISING
INTO THE LOW 90S SHOULD STILL SUPPORT PIEDMONT TROUGH/SEA BREEZE
ACTIVITY AND WILL CARRY SCHC POP NORTH...CHC SOUTH. A SIMILAR DAY ON
WEDNESDAY ALTHOUGH SOME DRY AIR IS PROGGED TO WORK INTO THE MID
LEVELS...SURFACE TEMPS RISING WELL INTO THE 90S SHOULD SUPPORT SEA
BREEZE AND PIEDMONT TROUGH CONVECTION ONCE AGAIN SO WILL CARRY
LOW-CHC POP WEDNESDAY AREA-WIDE. AM NOT ANTICIPATING ANYTHING MORE
THAN TYPICAL SUMMERTIME PULSE CONVECTION...BUT HIGH PWATS WILL
SUPPORT A HEAVY RAIN THREAT...WHILE PRECIP LOADING AND WEAK
INVERTED-V SIGNATURES COULD SUPPORT AN ISOLATED WET DOWNBURST.
MINS EACH NIGHT WILL FALL ONLY INTO THE MID 70S ON CONTINUED SW FLOW.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 140 PM MONDAY...WEAKNESS IN THE H5 PATTERN WILL EXIST ACROSS
THE REGION THROUGH THE WEEKEND LEADING TO A SOMEWHAT UNSETTLED
PATTERN...ESPECIALLY GIVEN VERY HIGH PRECIPITABLE WATER VALUES SHOWN
TO SPREAD INTO THE AREA. THUS CONVECTION IS A GOOD BET EACH DAY WITH
MAX HEATING...TIED TO AN INLAND TROUGH AND THE SEA BREEZE FRONT.
TOWARD THE WEEKEND...A WEAK FRONT MAY PUSH INTO THE AREA AND STALL
CAUSING AN ADDITIONAL FOCUS FOR STORMS. DURING THE EXTENDED PERIOD
THE WARMEST HIGHS ARE EXPECTED THURSDAY FOLLOWED BY A SLIGHT COOLING
TREND INTO THE WEEKEND GIVEN THE PROXIMITY OF THE AFOREMENTIONED
FRONT. MEANWHILE...MIN TEMPERATURES SHOULD BE AROUND CLIMO THROUGH
THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...ISOLATED SHOWERS SHOULD DEVELOP OVER THE NEXT SEVERAL
HOURS ALONG THE SEA BREEZE. THE PROBABILITY OF SHOWERS AT THE
COASTAL TERMINALS IS LOW AND WILL JUST MENTION VCSH IN TAFS.
SCATTERED CONVECTION...DEVELOPING ALONG THE PIEDMONT TROUGH...MAY
AFFECT FLO AND LBT THIS AFTERNOON AND EARLY EVE. CONFIDENCE HAS
INCREASED AND WILL INDICATE VCTS/TEMPO SHOWERS AT FLO/LBT. ALTHOUGH
THE CHANCE OF IFR IS LOW...CONVECTION WILL BE SLOW MOVING. IF A CELL
PARKS ITSELF OVER A TERMINAL...THEN IFR CONDITIONS COULD OCCUR AND
PERSIST FOR QUITE AWHILE.
CONVECTION SHOULD DISSIPATE THIS EVENING...BUT COULD REDEVELOP
OVERNIGHT OVER THE COASTAL WATERS. AFTER SUNRISE...EXPECT SCATTERED
LOW CLOUDS WITH BROKEN MID/UPPER CLOUDINESS ACROSS THE TERMINALS.
ANY SIGNIFICANT PRECIPITATION SHOULD HOLD OFF UNTIL LATE IN THE TAF
VALID PERIOD.
EXTENDED OUTLOOK...CHANCE OF AFTERNOON SHOWERS AND MORNING FOG EACH
DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM MONDAY...BERMUDA HIGH PRESSURE ANCHORED OFFSHORE WILL
KEEP SOUTHWEST WINDS IN THE 10 TO 15 KT RANGE THROUGH THE NEAR
TERM. SEAS WILL BE HIGHER THAN WOULD BE EXPECTED FROM THESE
GENERALLY LIGHT WINDS DUE TO A PERSISTENT 9 TO 10 SECOND ESE SWELL
IN THE 3 TO 4 FT RANGE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 140 PM MONDAY...BERMUDA HIGH PRESSURE OFFSHORE AND PIEDMONT
TROUGH INLAND WILL KEEP THE COASTAL WATERS SANDWICHED WITH A PINCHED
PRESSURE GRADIENT THROUGH THE PERIOD. THIS MEANS THAT SW FLOW WILL
PERSIST...INCREASING FROM AROUND 10 KTS EARLY TUESDAY...TO 10-15 KTS
EARLY WEDNESDAY...POSSIBLY UP TO 20 KTS LATE WEDNESDAY NEAR THE 20NM
BOUNDARY. SEAS WILL BE FORCED BY A COMBINATION OF A 3FT/9SEC SE
SWELL AND A 2FT/4 SEC SW WIND WAVE. TOGETHER...THESE WILL CREATE 3-5
FT SEAS...THE HIGHEST NEAR THE 20NM BOUNDARY OF THE NORTHERN 2
MARINE ZONES.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 140 PM MONDAY...THE PRESSURE GRADIENT BETWEEN BERMUDA HIGH
PRESSURE AND INLAND TROUGH WILL SUPPORT DECENT SOUTHWEST FLOW DURING
THURSDAY...POSSIBLY REACHING EXERCISE CAUTION LEVELS. THE STRONGER
SW FLOW WILL PERSIST INTO FRIDAY...THEN WILL VEER TO A WESTERLY
DIRECTION AND WEAKEN FRIDAY NIGHT AHEAD OF A SOUTHWARD MOVING FRONT.
THE EVENTUAL SOUTHWARD LOCATION OF THE FRONT IS IN QUESTION...BUT IF
IT DOES MOVE ACROSS THE WATERS SATURDAY THEN THE FLOW WILL BECOME
NORTHEASTERLY IN ITS WAKE. SEAS WILL BE HIGHEST THURSDAY INTO FRIDAY
DOMINATED BY THE HIGHER FREQUENCY SOUTHERLY WAVES. THESE WAVES WILL
MASK A WEAKENING EAST-SOUTHEAST SWELL THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...JDW
LONG TERM...SRP
AVIATION...MRR/RJD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
646 AM EDT MON JUL 16 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE CAROLINAS FROM THE
WESTERN ATLANTIC THROUGH MID WEEK AS A TROUGH OF LOW PRESSURE
LINGERS INLAND. A COLD FRONT WILL APPROACH FROM THE NORTH
THURSDAY AND FRIDAY...THEN STALL OVER OR JUST SOUTH OF THE AREA
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM MONDAY...SOME HIGHER CLOUDS AFFECTING THE
NORTHWESTERN HALF OF THE CWA THIS MORNING. REMAINDER OF THE AREA
IS GENERALLY CLEAR AND MUGGY WITH TEMPERATURES IN THE LOWER AND
MIDDLE 70S AS SOUTHERLY FLOW AROUND BERMUDA HIGH CONTINUES. UPPER
TROUGH AXIS EXTENDING FROM PENNSYLVANIA INTO NORTHERN NORTH
CAROLINA WILL MOVE EAST TODAY WITH SOME EMBEDDED SHORTWAVE ENERGY
TO CROSS OUR NORTHERN CWA. THIS UPPER ENERGY COUPLED WITH A
THERMALLY- INDUCED TROUGH ACROSS THE PIEDMONT WILL LEAD TO A
DECENT COVERAGE OF SHOWERS AND TSTMS ACROSS ROUGHLY THE
NORTHWESTERN HALF OF THE CWA TODAY. THE RAP CONTINUES TO INDICATE CAPE
VALUES OF 2500 TO 3000 J/KG ACROSS THE NORTHERN COUNTIES AND BOTH
THE GFS AND GEMS SHOW THE BEST CHANCE OF MEASURABLE PRECIPITATION
OVER THE NORTHERN THIRD OR SO OF OUR CWA. WHILE EASTERN NC IS NOT
OUTLOOKED BY SPC...WOULD NOT BE SURPRISED TO SEE SOME LOCALLY
STRONG STORMS IN THE AFOREMENTIONED NORTHERN AREAS ESPECIALLY THIS
AFTERNOON AND EVENING. FOLLOWED A PERSISTENCE ROUTE FOR MAXIMUM
TEMPERATURES WITH MOST MAX TEMPERATURES IN THE 86 TO 90 DEGREE
RANGE FOR TODAY. POPS WILL RANGE FROM HIGH CHANCE NORTH AND
NORTHEAST...TAPERING TO SLIGHT CHC ALONG THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 335 AM MONDAY...PER LATEST RUNS OF MOST ALL OF THE SHORT-
RANGE MODELS...PRECIPITATION ENDS QUICKLY WITH LOSS OF HEATING
TONIGHT...WITH MINIMAL COVERAGE AFTER 03Z. VERY SIMILAR
TEMPERATURES TONIGHT TO THE PAST SEVERAL NIGHT...RANGING FROM 73
TO 78 DEGREES WITH THE WARMER READINGS NEAR THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 330 AM MON...SCT AFTERNOON SEA BREEZE CONVECTION WILL
HIGHLIGHT THE TUE/WED TIME PERIOD. A WET PATTERN APPEARS TO BE
UNFOLDING FOR THE END OF THE WEEK AND INTO THE WEEKEND.
WEAK TROUGHING WILL BE IN PLACE TUE AND INTO WED...SETTING THE
STAGE FOR SCT AFTERNOON THUNDERSTORMS EACH DAY...FOCUSED ALONG
TYPICAL HWY 17 CORRIDOR. LOW LEVEL THICKNESSES WILL BE AROUND
1425M...WHICH WOULD TRANSLATE TO AFTERNOON HIGHS AROUND 90 EACH
DAY.
MODELS IN GOOD AGREEMENT ON SYNOPTIC REGIME LATE THIS COMING
WEEK...WITH AMPLIFYING CENTRAL CONUS RIDGE...TRANSLATING TO
TROUGHING IN THE EASTERN CONUS. TIMING OF SFC COLD FRONT MOVING
INTO EASTERN NC LOOKS TO BE SOMETIME LATE THUR/EARLY FRI. LATEST
16/00Z ECMWF INDICATES SFC COLD FRONT STALLING ACROSS EASTERN NC
WHICH WOULD BRING BOUTS OF THUNDERSHOWERS ACROSS THE AREA
THROUGH THE WEEKEND. INC POPS TO THE HIGH CHANCE RANGE THROUGH AT
LEAST THE BEGINNING OF THE WEEKEND...AS THIS SOLN HAS SUPPORT FROM
16/00Z GEM. OPERATIONAL GFS PUSHES THE FRONT JUST SOUTH OF THE
AREA THIS WEEKEND...WHICH WOULD PUSH PRECIP AXIS JUST TO THE SOUTH
OF THE CWA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 00Z TUESDAY/...
AS OF 645 AM MONDAY...IT APPEARS THAT LOW-LEVEL MIXING IN THE FORM
OF SOUTHWEST WINDS OF 3 TO 5 KNOTS WILL KEEP ANY EARLY MORNING FOG
FROM DEVELOPING AT THE TAF SITES THIS MORNING. CONVECTIVE ACTIVITY
EXPECTED MON AFTN OVER OUR NORTHERN CWA AND WILL ADD A VCTS AT THE
PGV TAF.
LONG TERM /MON NIGHT THROUGH FRI/
AS OF 330 AM MON...VFR CONDITIONS ARE EXPECTED FOR MOST OF THE
PERIOD. THERE WILL BE SCATTERED LATE DAY/EARLY EVENING CONVECTION
TUE-WED. LATE NIGHT/EARLY MORNING FOG/STRATUS WILL BE POSSIBLE
ESPECIALLY IN AREAS THAT RECEIVE SIGNIFICANT RAINFALL. BETTER CHANCE
OF WIDESPREAD THUNDERSTORMS ARRIVES LATE THUR THROUGH FRI AND
POSSIBLY INTO THE WEEKEND...AS A FRONT PUSHES INTO THE AREA FROM THE
NORTH AND STALLS OVER OR JUST SOUTH OF THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 645 AM MONDAY...CONTINUING TO SEE SOUTHWEST WINDS OF 10 TO
15 KNOTS WITH OCCASIONAL GUSTS TO 20 KNOTS THIS MORNING. THIS
PATTERN WILL HOLD THROUGH TONIGHT AS GRADIENT BETWEEN INLAND
TROUGH AND BERMUDA HIGH HOLDS. SEAS WILL GENERALLY BE 3 TO 4 FEET
TODAY WITH A FEW 5 FOOT SEAS LIKELY LATER IN THE DAY AND TONIGHT.
NO SIGNIFICANT CHANGES TO THE CURRENT MARINE FORECAST.
LONG TERM /MON NIGHT THROUGH FRI/
AS OF 330 AM MON...INLAND TROF/BERMUDA HIGH PRESSURE PATTERN WILL
PRODUCE TYPICAL SW FLOW OVER AREA DURING PERIOD. SW WINDS GENERALLY
AROUND 15 KT TUESDAY THROUGH MIDWEEK...WITH SOME SPEEDS UP TO 20 KT
POSSIBLE ESP MIDWEEK INTO THUR AS GRADIENT INC JUST A BIT. SEAS WILL
GENERALLY BE 2 TO 3 FEET NEAR SHORE WITH 4 TO 5 FEET FOR THE OUTER
WATERS. COULD SEE 6 FT SEAS FOR OUTER CENTRAL WATERS WATERS LATE WED
THROUGH THE END OF THE WEEK. COLD FRONT WILL PASS THROUGH LATE FRI
INTO EARLY WEEKEND...WITH WINDS BECOMING NORTHEASTERLY BEHIND THE
FRONTAL PASSAGE. FRONT WILL STALL ACROSS THE AREA WATERS KEEPING A
THREAT FOR THUNDERSTORMS THROUGH THE WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
338 AM EDT MON JUL 16 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE CAROLINAS FROM THE
WESTERN ATLANTIC THROUGH MID WEEK AS A TROUGH OF LOW PRESSURE
LINGERS INLAND. A COLD FRONT WILL APPROACH FROM THE NORTH
THURSDAY AND FRIDAY...THEN STALL OVER OR JUST SOUTH OF THE AREA
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM MONDAY...BERMUDA RIDGE CONTINUES AT THE SURFACE
PROVIDING WARM MOIST AIR INTO EASTERN NORTH CAROLINA. WEAK 500 MB
LOW IS SPINNING OFF THE GEORGIA/FLORIDA COAST WHILE A 500 MB
TROUGH AXIS EXTENDS FROM WESTERN PENNSYLVANIA DOWN ACROSS WEST
VIRGINIA INTO FAR NORTHWESTERN NORTH CAROLINA. THIS TROUGH WILL
CONTINUE TOWARD THE EAST WITH EMBEDDED SHORTWAVES TO CROSS OUR
NORTHERN CWA. THIS UPPER ENERGY COUPLED WITH A THERMALLY-INDUCED
TROUGH ACROSS THE PIEDMONT WILL LEAD TO A DECENT COVERAGE OF
SHOWERS AND TSTMS ACROSS ROUGHLY THE NORTHWESTERN HALF OF THE CWA
TODAY. THE RAP INDICATES CAPE VALUES OF 2500 TO 3000 J/KG ACROSS
THE NORTHERN COUNTIES AND BOTH THE GFS AND GEMS SHOW THE BEST
CHANCE OF MEASURABLE PRECIPITATION OVER THE NORTHERN THIRD OR SO
OF OUR CWA. WHILE EASTERN NC IS NOT OUTLOOKED BY SPC...WOULD NOT
BE SURPRISED TO SEE SOME LOCALLY STRONG STORMS IN THE
AFOREMENTIONED NORTHERN AREAS ESPECIALLY THIS AFTERNOON AND
EVENING. FOLLOWED A PERSISTENCE ROUTE FOR MAXIMUM TEMPERATURES
WITH MOST MAX TEMPERATURES IN THE 86 TO 90 DEGREE RANGE FOR TODAY.
POPS WILL RANGE FROM HIGH CHANCE NORTH AND NORTHEAST...TAPERING TO
SLIGHT CHC ALONG THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 335 AM MONDAY...PER LATEST RUNS OF MOST ALL OF THE SHORT-
RANGE MODELS...PRECIPITATION ENDS QUICKLY WITH LOSS OF HEATING
TONIGHT...WITH MINIMAL COVERAGE AFTER 03Z. VERY SIMILAR
TEMPERATURES TONIGHT TO THE PAST SEVERAL NIGHT...RANGING FROM 73
TO 78 DEGREES WITH THE WARMER READINGS NEAR THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 330 AM MON...SCT AFTERNOON SEA BREEZE CONVECTION WILL
HIGHLIGHT THE TUE/WED TIME PERIOD. A WET PATTERN APPEARS TO BE
UNFOLDING FOR THE END OF THE WEEK AND INTO THE WEEKEND.
WEAK TROUGHING WILL BE IN PLACE TUE AND INTO WED...SETTING THE
STAGE FOR SCT AFTERNOON THUNDERSTORMS EACH DAY...FOCUSED ALONG
TYPICAL HWY 17 CORRIDOR. LOW LEVEL THICKNESSES WILL BE AROUND
1425M...WHICH WOULD TRANSLATE TO AFTERNOON HIGHS AROUND 90 EACH
DAY.
MODELS IN GOOD AGREEMENT ON SYNOPTIC REGIME LATE THIS COMING
WEEK...WITH AMPLIFYING CENTRAL CONUS RIDGE...TRANSLATING TO
TROUGHING IN THE EASTERN CONUS. TIMING OF SFC COLD FRONT MOVING
INTO EASTERN NC LOOKS TO BE SOMETIME LATE THUR/EARLY FRI. LATEST
16/00Z ECMWF INDICATES SFC COLD FRONT STALLING ACROSS EASTERN NC
...WHICH WOULD BRING BOUTS OF THUNDERSHOWERS ACROSS THE AREA
THROUGH THE WEEKEND. INC POPS TO THE HIGH CHANCE RANGE THROUGH AT
LEAST THE BEGINNING OF THE WEEKEND...AS THIS SOLN HAS SUPPORT FROM
16/00Z GEM. OPERATIONAL GFS PUSHES THE FRONT JUST SOUTH OF THE
AREA THIS WEEKEND...WHICH WOULD PUSH PRECIP AXIS JUST TO THE SOUTH
OF THE CWA.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 00Z TUESDAY/...
AS OF 1240 AM MONDAY...NO CHANGES IN CURRENT THINKING FOR AVIATION.
A LIGHT SOUTHWEST WINDS OF 3 TO 6 KNOTS AT THE TAF SITES SHOULD
PROVIDE ENOUGH MIXING TO KEEP CHANGES OF LATE NIGHT FOG AND
STRATUS MINIMAL...ALTHOUGH CANNOT COMPLETELY RULE OUT A PATCH OR
TWO OF FOG TOWARD MORNING. CONVECTIVE ACTIVITY EXPECTED MON AFTN
BUT MAINLY SCATTERED COVERAGE SO NO TAF MENTION AS YET UNTIL
TIMING/COVERAGE CAN BE BETTER RESOLVED.
LONG TERM /MON NIGHT THROUGH FRI/
AS OF 330 AM MON...VFR CONDITIONS ARE EXPECTED FOR MOST OF THE
PERIOD. THERE WILL BE SCATTERED LATE DAY/EARLY EVENING CONVECTION
TUE-WED. LATE NIGHT/EARLY MORNING FOG/STRATUS WILL BE POSSIBLE
ESPECIALLY IN AREAS THAT RECEIVE SIGNIFICANT RAINFALL. BETTER CHANCE
OF WIDESPREAD THUNDERSTORMS ARRIVES LATE THUR THROUGH FRI AND
POSSIBLY INTO THE WEEKEND...AS A FRONT PUSHES INTO THE AREA FROM THE
NORTH AND STALLS OVER OR JUST SOUTH OF THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 335 AM MONDAY...SOUTHWEST WINDS OF 10 TO 15 KNOTS WITH
OCCASIONAL GUSTS TO 20 KNOTS WILL CONTINUE TODAY AND TONIGHT.
GRADIENT BETWEEN BERMUDA HIGH AND SURFACE TROUGH INLAND WILL KEEP
THE SOUTHWEST WINDS GUSTY AT TIMES. SEAS ARE GENERALLY 3 TO 4 FEET
BUT WILL SEE SOME OCCASIONAL 5 FOOTERS ESPECIALLY LATE THIS
AFTERNOON AND TONIGHT PER LATEST WAVEWATCH AND LOCAL SWAN MODEL
WHICH ARE IN GOOD AGREEMENT AT THIS TIME.
LONG TERM /MON NIGHT THROUGH FRI/
AS OF 330 AM MON...INLAND TROF/BERMUDA HIGH PRESSURE PATTERN WILL
PRODUCE TYPICAL SW FLOW OVER AREA DURING PERIOD. SW WINDS GENERALLY
AROUND 15 KT TUESDAY THROUGH MIDWEEK...WITH SOME SPEEDS UP TO 20 KT
POSSIBLE ESP MIDWEEK INTO THUR AS GRADIENT INC JUST A BIT. SEAS WILL
GENERALLY BE 2 TO 3 FEET NEAR SHORE WITH 4 TO 5 FEET FOR THE OUTER
WATERS. COULD SEE 6 FT SEAS FOR OUTER CENTRAL WATERS WATERS LATE WED
THROUGH THE END OF THE WEEK. COLD FRONT WILL PASS THROUGH LATE FRI
INTO EARLY WEEKEND...WITH WINDS BECOMING NORTHEASTERLY BEHIND THE
FRONTAL PASSAGE. FRONT WILL STALL ACROSS THE AREA WATERS KEEPING A
THREAT FOR THUNDERSTORMS THROUGH THE WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1242 AM EDT MON JUL 16 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE CAROLINAS FROM THE
WESTERN ATLANTIC THROUGH MID WEEK WITH A TROUGH OF LOW PRESSURE
INLAND. A COLD FRONT WILL APPROACH FROM THE NORTH THURSDAY AND
FRIDAY...THEN STALL OVER THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1235 AM MONDAY...BERMUDA RIDGE CONTINUES TO HOLD PROVIDING A
LIGHT SW FLOW ACROSS THE REGION TONIGHT. SKIES ARE GENERALLY CLEAR
AND TEMPERATURES ARE HOVERING IN THE MIDDLE 70S TO LOWER 80S AREA-
WIDE. LATEST RAP HINTS AT SOME LIGHT PRECIPITATION NEAR THE SOUNDS
TOWARD MORNING...BUT WILL KEEP THE PRECIP OUT AT THIS TIME GIVEN
LACK OF FORCING. NO SIGNIFICANT CHANGES TO FORECAST EXCEPT TO
REMOVE SMALL POPS OFFSHORE...AS SKIES HAVE GONE CLEAR IN THE
OFFSHORE WATERS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
AS OF 300 PM SUNDAY...BERMUDA HIGH/PIEDMONT TROF PATTERN WILL
CONTINUE AT SFC ON MONDAY...BUT MODELS INDICATE UPR SHRT WV WILL
MOVE IN FROM NW DURING AFTN. THIS FEATURE WILL PROVIDE ADDITIONAL
TRIGGER FOR SCT CONVECTIVE DEVELOPMENT DURING AFTN INTO EARLY
EVENING...MAINLY FOR INLAND SECTIONS. A FEW STRONGER STORMS LIKELY
WITH FCST SOUNDINGS INDICATING PRECIP WATER BACK TO AROUND 2
INCHES...LI`S -5 TO -7 AND CAPES NEAR 3500. CONTINUED PREVIOUS FCST
POPS OF 40 INLAND TO 20 COAST. LATEST MOS GDNC IN GOOD AGREEMENT ON
MAX TEMPS FROM LOWER 90S INLAND TO UPR 80S COAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AS OF 3 PM SUN...THE 12Z GFS/00Z ECMWF ARE IN RATHER CLOSE
AGREEMENT THROUGH THE MIDDLE OF THE WEEK...WITH THE ECMWF LOOKING
BETTER THAN THE GFS IN ITS HANDLING OF THE BACKDOOR FRONT LATE
THIS WEEK INTO THE WEEKEND. PATTERN WILL REMAIN THE SAME THROUGH
MIDWEEK...HIGH PRESSURE CENTERED IN THE SOUTH ATLANTIC WITH A WEAK
TROF OVER THE CENTRAL PART OF THE STATE. CONVECTION WILL BE
PRIMARILY SEABREEZE DRIVEN...DISSIPATING QUICKLY WITH SUNSET AND
ONLY ISOLATED SHOWERS OVER THE COASTAL WATERS EACH NIGHT. POPS
WILL BE NO HIGHER THAN 30 PERCENT. HOWEVER...BY THURSDAY A
BACKDOOR COLD FRONT WILL APPROACH FROM THE NORTH WITH AN
ACCOMPANYING INCREASE IN POPS TO THE 30-50 PERCENT RANGE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 00Z TUESDAY/...
AS OF 1240 AM MONDAY...NO CHANGES IN CURRENT THINKING. A LIGHT
SOUTHWEST WINDS OF 3 TO 6 KNOTS AT THE TAF SITES SHOULD PROVIDE
ENOUGH MIXING TO KEEP CHANGES OF LATE NIGHT FOG AND STRATUS
MINIMAL...ALTHOUGH CANNOT COMPLETELY RULE OUT A PATCH OR TWO OF
FOG TOWARD MORNING. CONVECTIVE ACTIVITY EXPECTED MON AFTN BUT
MAINLY SCATTERED COVERAGE SO NO TAF MENTION AS YET UNTIL
TIMING/COVERAGE CAN BE BETTER RESOLVED.
LONG TERM /MON NIGHT THROUGH FRI/
AS OF 3 PM SUN...GENERALLY VFR THROUGH THE PERIOD. CONVECTION WILL
BE MAINLY WIDELY SCATTERED THROUGH WEDNESDAY AND LIMITED TO THE
MID-AFTERNOON AND EVENING HOURS. A BACKDOOR COLD FRONT WILL
APPROACH FROM THE NORTH ON THURSDAY WITH SHOWERS AND THUNDERSTORMS
BECOMING MORE NUMEROUS AND POSSIBLE BOTH DAY AND NIGHT. SURFACE
WINDS WILL CONTINUE FROM THE SOUTHWEST GENERALLY 10 KNOTS OR LESS.
&&
.MARINE...
SHORT TERM /THROUGH MONDAY/...
AS OF 1240 AM MONDAY...MODERATE SOUTHWEST WINDS OF 15 TO 20 KNOTS
CONTINUE ON THE SOUNDS AND COASTAL WATERS EARLY THIS MORNING. THIS
GRADIENT WILL REMAIN TIGHT BETWEEN THE BERMUDA HIGH WELL OFFSHORE
AND A TROUGH INLAND. LATEST MODELS SUPPORT PREVIOUS FCST THINKING
WITH THESE SPEEDS CONTINUING OVER AREA THROUGH MONDAY. SWAN AND
WW3 IN GOOD AGREEMENT WITH COMBINED SEAS OF 2-5 FT.
LONG TERM /MON NIGHT THROUGH FRI/
AS OF 3 PM SUN...00Z ECMWF AND 12Z GFS/NAM IN VERY CLOSE AGREEMENT
THROUGH THE END OF THE WEEK AND USED AN OVERALL BLEND OF THE THREE
FOR THE MARINE WINDS. SOUTHWEST FLOW WILL CONTINUE WITH HIGH
PRESSURE CENTERED IN THE SOUTH ATLANTIC. A BACKDOOR COLD FRONT
WILL APPROACH FROM THE NORTH THURSDAY AND DROP IN THE COASTAL
WATERS ON FRIDAY. WIND SPEEDS WILL CONTINUE GENERALLY 10-15 KNOTS
FOR MONDAY AND TUESDAY. WINDS WILL INCREASE WEDNESDAY AND THURSDAY
AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF THE FRONT...THEN
DIMINISH ON FRIDAY AS THE FRONT SETTLES IN. USED THE 12Z WAVEWATCH
FOR SEAS...WHICH INCREASE TO MARGINAL SMALL CRAFT WEDNESDAY NIGHT
INTO THURSDAY NIGHT MAINLY FOR THE WATERS FROM CAPE HATTERAS
SOUTH. SEAS WILL SUBSIDE ON FRIDAY AS WINDS DIMINISH.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...HSA
AVIATION...CTC//BTC/HSA
MARINE...CTC/BTC/HSA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1001 PM CDT TUE JUL 17 2012
.SHORT TERM...
ADJUSTED SKY AND TEMPERATURE TO MATCH TRENDS. SCATTERED TO
ISOLATED THUNDERSTORMS OVER THE SOUTHWEST AND WEST CENTRAL
PORTIONS OF THE STATE. STORMS ARE MARGINALLY SEVERE SOUTHWEST AND
AND WITH HEAVY RAIN WEST CENTRAL. CONTINUED SMALL STREAM ADVISORY
FOR GOLDEN VALLEY COUNTY WITH ONE SEVERE STORM TRACKING EAST ALONG
SOUTH DAKOTA BORDER IN ADAMS COUNTY. UPSHOT IS NO BIG CHANGES.
.AVIATION...
HAVE FOLLOWED HRRR MODEL IN ESTIMATING WEST TO EAST TIMING OF BEST
THUNDERSTORM CHANCES OVERNIGHT AT KBIS/KISN/KMOT/KDIK...WHERE VCTS
GROUPS HAVE BEEN INCLUDED. SOME MVFR FOG COULD ALSO OCCUR AT
KJMS/KBIS DURING THE EARLY MORNING HOURS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HW
AVIATION...RK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
816 PM CDT TUE JUL 17 2012
.DISCUSSION...
MADE SOME ADJUSTMENTS TO POPS AND WEATHER FOR CURRENT TRENDS...AND
TO INCREASE OVERNIGHT ACROSS THE NORTH. A COMPLEX OF STORMS IN NW
SOUTH DAKOTA MAY SKIRT THE SOUTHERN COUNTIES...AND A LINE OF
STORMS IS ALSO MOVING INTO NE MONTANA...POTENTIALLY IMPACTING THE
FORECAST AREA LATER TONIGHT. THE OVERALL ENVIRONMENT FOR SEVERE
WEATHER IS NOT VERY FAVORABLE...WITH RELATIVELY WEAK DEEP LAYER
SHEAR AND LIMITED INSTABILITY. SPC HAS DROPPED THE WESTERN AND
SOUTHERN COUNTIES FROM THE DAY 1 SLIGHT RISK AREA. HOWEVER...THERE
IS STILL PLENTY OF MOISTURE...AND TRAINING CELLS IN GOLDEN VALLEY
COUNTY PROMPTED A SMALL STREAM FLOOD ADVISORY. AN ISOLATED SEVERE
STORM CAN`T BE COMPLETELY DISCOUNTED TONIGHT.
&&
.AVIATION...
HAVE FOLLOWED HRRR MODEL IN ESTIMATING WEST TO EAST TIMING OF BEST
THUNDERSTORM CHANCES OVERNIGHT AT KBIS/KISN/KMOT/KDIK...WHERE VCTS
GROUPS HAVE BEEN INCLUDED. SOME MVFR FOG COULD ALSO OCCUR AT
KJMS/KBIS DURING THE EARLY MORNING HOURS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION/AVIATION...RK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
403 PM EDT MON JUL 16 2012
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO THE REGION
TODAY PROVIDING DRY...BUT CONTINUED VERY WARM AND HUMID CONDITIONS
WHICH WILL LAST THROUGH MID WEEK. A COLD FRONT WILL USHER IN A
COOLER...AND MUCH DRIER AIRMASS LATER THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LOW CLOUD SHIELD HAS BROKEN UP TO A FIELD OF SCT-BKN CU...WITH
SOME ENHANCED CU EVIDENT OVER NERN PA. THIS IS IN AN AREA OF WEAK
MOISTURE CONVERGENCE AND CAPES AROUND 2000J ACCORDING TO LATEST
RAP ANALYSIS. 14Z HRRR STILL WANTS TO POP OFF A FEW SMALL CELLS
OVER MY EASTERN ZONES...AND I CAN`T DISCOUNT THEM TOTALLY GIVEN
THE INSTABILITY...BUT MID LEVEL TEMPS ARE ALREADY QUITE WARM AND
IT WILL BE HARD TO PUSH PARCELS THROUGH THE CAP WITH SUCH WEAK
FORCING. SO WHILE AN ISOLATED STORM IS NOT OUT OF THE
QUESTION...COVERAGE IS EXPECTED TO BE MUCH LESS THAN 20% SO WILL
STICK WITH THE DRY FCST AND HANDLE ANY ROGUE STORMS THAT MAY FORM
WITH SHORT TERM UPDATES.
M/CLEAR SKIES SHOULD PREVAIL EARLY TONIGHT WITH SOME INC IN
CLOUDS PSBL OVR THE NRN TIER MTNS TWD DAYBREAK AS LOW PRES TRACKS
EWD FM THE UPPER GRT LKS ACRS SRN ONT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
TUESDAY WILL BE HOT AND HUMID AS A BIG SURGE IN HEAT SLIDES EAST
COURTESY OF A SFC HIGH OFF TO OUR SOUTH. A BULLS-EYE OF PLUS 2-3
ST DEVIATION 850 MB TEMPS...AROUND 22C...AND A SLIGHTLY ANOMALOUS
WESTERLY 925-850 MB DOWNSLOPING FLOW WILL RESULT IN A PEAK IN THE
UPCOMING MINI HEAT WAVE TUESDAY AFTERNOON.
A HEAT ADVISORY FOR TUESDAY FROM 16-23Z WAS ISSUED EARLIER THIS
MORNING AFTER COORDINATION WITH WFOS LWX AND PHI. MAX TEMPS WILL
REACH THE 90S IN ALL VALLEY LOCATIONS TUESDAY AFTERNOON...AND WILL
BE IN THE 95-97F RANGE ACROSS MUCH OF THE LOWER SUSQ VALLEY. HEAT
INDICES WILL PEAK AT 100-102F. EVEN ACROSS THE NRN AND WESTERN
MTNS...TEMPS WILL TOP OUT BETWEEN 87-90F.
AN EAST-WEST RIBBON OF WARM 700MB TEMPS IN THE 10-12C RANGE WILL
CAP OFF CONVECTION TUESDAY AFTERNOON AND EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE MEAT OF THE WEATHER ACTION IN THE FORM OF HEAT...HUMIDITY...AND
AN APPROACHING POTENT COLD FRONT WILL OCCUR WEDNESDAY AFTERNOON AND
EVENING. THE COMBINATION OF THESE ELEMENTS WITH A BELT OF MDTLY
STRONG WESTERLY WINDS OF 30-35KTS AT 700 MB WILL CREATE A FAVORABLE
SETUP FOR STRONG TO POTENTIALLY SEVERE TSRA DURING THIS TIME PERIOD.
THE FRONTAL BOUNDARY WILL SAG SLOWLY TO THE SOUTH ACROSS THE STATE
LATE WEDNESDAY AND WED NIGHT...WITH LATEST GUIDANCE SUGGESTING A
WEAKER SOUTHWARD PUSH OF THE FRONT. THIS MAY KEEP SHOWERS LINGER
INTO THURSDAY.
A SECONDARY PUSH OF DEEPER/COOLER AIR WILL OCCUR THURSDAY WITH LLVL
WINDS VEERING ALL THE WAY AROUND TO THE NNE BY LATE IN THE DAY
THURSDAY.
THE SOUTHERN THIRD OF THE STATE STANDS THE BEST CHC TO SEE A SHOWER
/OR AFTERNOON TSRA/ THURSDAY AS THE NRN EDGE OF HIGH PWAT AIR /IN
THE 44-48MM RANGE/ WILL STAY NEAR THE MASON/DIXON LINE.
FOR LATER THURSDAY NIGHT THROUGH SATURDAY...A LARGE AREA OF
ANOMALOUSLY DRY PWAT AIR /IN THE 16-20MM RANGE/ SINKS SOUTH FROM
ONTARIO CANADA. THIS REFRESHING AIRMASS WILL SUPPLY US WITH LITTLE
OR NOR CHC FOR RAIN DURING THIS PORTION OF THE EXTENDED FCST PERIOD.
HIGH TEMPS WEDNESDAY /RANGING FROM THE U70S NW...TO 92-94F SE/ WILL
BE A GOOD 4-6 DEG F ABOVE NORMAL IN MOST LOCATIONS...EXCEPT FOR
PERHAPS PORTIONS OF THE NRN MTNS WHERE SHOWERS MAY SPREAD INTO THE
AREA DURING THE LATE MORNING AFTERNOON HOURS...ROBBING SEVERAL HOURS
OF HEATING.
AFTERNOON HIGH TEMPS WILL TREND DOWN GRADUALLY THURSDAY THROUGH
SATURDAY /BACK TO AROUND NORMAL/. NIGHTTIME LOWS WILL BECOME QUITE
CHILLY...WITH A FEW OF THE COLDER LOCATIONS NEAR AND TO THE EAST OF
KBFD SEEING A 48 OR 49F DAYBREAK TEMP.
FRIDAY AND SATURDAY WILL BE MAINLY DRY PER THE 00Z GEFS AND EC MODEL.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
ALL TERMINALS ARE VFR AS OF MID DAY...AND WILL CONTINUE THAT WAY
INTO THE OVERNIGHT..
AN ISOLATED SHRA/TSRA IS POSSIBLE OVR ERN SXNS...BUT POINT-
PROBABILITIES ARE ESTIMATED TO BE LESS THAN 20 PCT AT BEST...AND
THEREFORE WILL NOT MENTION IN TAFS.
HIGH PRES WILL PROVIDE VFR CONDS OVERNIGHT...WITH SOME PATCHY FOG
POSSIBLE TWD DAYBREAK TUES. THE NEXT CHANCE FOR SIGNIFICANT WX
WILL COME ON WEDNESDAY...AS AN APPROACHING COLD FRONT TRIGGERS SCT
STG-SVR TSTMS. HIGH PRES WILL DOMINATE THE WEATHER PATTERN FOR THE
END OF THE WEEK.
OUTLOOK...
TUE...VFR. NO SIG WX.
WED...SCT TSTM IMPACTS LKLY ASSOCD WITH COLD FROPA.
THU-SAT...VFR. NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR PAZ036-056-057-
059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
142 PM EDT MON JUL 16 2012
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO THE REGION
TODAY PROVIDING DRY...BUT CONTINUED VERY WARM AND HUMID CONDITIONS
WHICH WILL LAST THROUGH MID WEEK. A COLD FRONT WILL USHER IN A
COOLER...AND MUCH DRIER AIRMASS THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW CLOUD SHIELD HAS BROKEN UP TO A FIELD OF SCT-BKN CU...WITH
SOME ENHANCED CU EVIDENT OVER NERN PA. THIS IS IN AN AREA OF WEAK
MOISTURE CONVERGENCE AND CAPES AROUND 2000J ACCORDING TO LATEST
RAP ANALYSIS. 14Z HRRR STILL WANTS TO POP OFF A FEW SMALL CELLS
OVER MY EASTERN ZONES...AND I CAN`T DISCOUNT THEM TOTALLY GIVEN
THE INSTABILITY...BUT MID LEVEL TEMPS ARE ALREADY QUITE WARM AND
IT WILL BE HARD TO PUSH PARCELS THROUGH THE CAP WITH SUCH WEAK
FORCING. SO WHILE AN ISOLATED STORM IS NOT OUT OF THE
QUESTION...COVERAGE IS EXPECTED TO BE MUCH LESS THAN 20% SO WILL
STICK WITH THE DRY FCST AND HANDLE ANY ROGUE STORMS THAT MAY FORM
WITH SHORT TERM UPDATES.
M/CLEAR SKIES SHOULD PREVAIL EARLY TONIGHT WITH SOME INC IN
CLOUDS PSBL OVR THE NRN TIER MTNS TWD DAYBREAK AS LOW PRES TRACKS
EWD FM THE UPPER GRT LKS ACRS SRN ONT.
&&
.SHORT TERM /TUESDAY/...
TUESDAY WILL BE HOT AND HUMID AS A BIG SURGE IN HEAT SLIDES EAST
COURTESY OF A SFC HIGH OFF TO OUR SOUTH. A BULLS-EYE OF PLUS 2-3
ST DEVIATION 850 MB TEMPS...AROUND 22C...AND A SLIGHTLY ANOMALOUS
WESTERLY 925-850 MB DOWNSLOPING FLOW WILL RESULT IN A PEAK IN THE
UPCOMING MINI HEAT WAVE TUESDAY AFTERNOON.
A HEAT ADVISORY FOR TUESDAY FROM 16-23Z WAS ISSUED EARLIER THIS
MORNING AFTER COORDINATION WITH WFOS LWX AND PHI. MAX TEMPS WILL
REACH THE 90S IN ALL VALLEY LOCATIONS TUESDAY AFTERNOON...AND WILL
BE IN THE 95-97F RANGE ACROSS MUCH OF THE LOWER SUSQ VALLEY. HEAT
INDICES WILL PEAK AT 100-102F. EVEN ACROSS THE NRN AND WESTERN
MTNS...TEMPS WILL TOP OUT BETWEEN 87-90F.
AN EAST-WEST RIBBON OF WARM 700MB TEMPS IN THE 10-12C RANGE WILL
CAP OFF CONVECTION TUESDAY AFTERNOON AND EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE MEAT OF THE WEATHER ACTION IN THE FORM OF HEAT...HUMIDITY...AND
AN APPROACHING POTENT COLD FRONT WILL OCCUR WEDNESDAY AFTERNOON AND
EVENING. THE COMBINATION OF THESE ELEMENTS WITH A BELT OF MDTLY
STRONG WESTERLY WINDS OF 30-35KTS AT 700 MB WILL CREATE A FAVORABLE
SETUP FOR STRONG TO POTENTIALLY SEVERE TSRA DURING THIS TIME PERIOD.
THE FRONTAL BOUNDARY WILL SAG SLOWLY TO THE SOUTH ACROSS THE STATE
LATE WEDNESDAY AND WED NIGHT.
A SECONDARY PUSH OF DEEPER/COOLER AIR WILL OCCUR THURSDAY WITH LLVL
WINDS VEERING ALL THE WAY AROUND TO THE NNE BY LATE IN THE DAY
THURSDAY.
THE SOUTHERN THIRD OF THE STATE STANDS THE BEST CHC TO SEE A SHOWER
/OR AFTERNOON TSRA/ THURSDAY AS THE NRN EDGE OF HIGH PWAT AIR /IN
THE 44-48MM RANGE/ WILL STAY NEAR THE MASON/DIXON LINE.
FOR LATER THURSDAY NIGHT THROUGH SATURDAY...A LARGE AREA OF
ANOMALOUSLY DRY PWAT AIR /IN THE 16-20MM RANGE/ SINKS SOUTH FROM
ONTARIO CANADA. THIS REFRESHING AIRMASS WILL SUPPLY US WITH LITTLE
OR NOR CHC FOR RAIN DURING THIS PORTION OF THE EXTENDED FCST PERIOD.
HIGH TEMPS WEDNESDAY /RANGING FROM THE U70S NW...TO 92-94F SE/ WILL
BE A GOOD 4-6 DEG F ABOVE NORMAL IN MOST LOCATIONS...EXCEPT FOR
PERHAPS PORTIONS OF THE NRN MTNS WHERE SHOWERS MAY SPREAD INTO THE
AREA DURING THE LATE MORNING AFTERNOON HOURS...ROBBING SEVERAL HOURS
OF HEATING.
AFTERNOON HIGH TEMPS WILL TREND DOWN GRADUALLY THURSDAY THROUGH
SATURDAY /BACK TO AROUND NORMAL/. NIGHTTIME LOWS WILL BECOME QUITE
CHILLY...WITH A FEW OF THE COLDER LOCATIONS NEAR AND TO THE EAST OF
KBFD SEEING A 48 OR 49F DAYBREAK TEMP.
FRIDAY AND SATURDAY WILL BE MAINLY DRY PER THE 00Z GEFS AND EC MODEL.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
ALL TERMINALS ARE VFR AS OF MID DAY...AND WILL CONTINUE THAT WAY
INTO THE OVERNIGHT..
AN ISOLATED SHRA/TSRA IS POSSIBLE OVR ERN SXNS...BUT POINT-
PROBABILITIES ARE ESTIMATED TO BE LESS THAN 20 PCT AT BEST...AND
THEREFORE WILL NOT MENTION IN TAFS.
HIGH PRES WILL PROVIDE VFR CONDS OVERNIGHT...WITH SOME PATCHY FOG
POSSIBLE TWD DAYBREAK TUES. THE NEXT CHANCE FOR SIGNIFICANT WX
WILL COME ON WEDNESDAY...AS AN APPROACHING COLD FRONT TRIGGERS SCT
STG-SVR TSTMS. HIGH PRES WILL DOMINATE THE WEATHER PATTERN FOR THE
END OF THE WEEK.
OUTLOOK...
TUE...VFR. NO SIG WX.
WED...SCT TSTM IMPACTS LKLY ASSOCD WITH COLD FROPA.
THU-SAT...VFR. NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR PAZ036-056-057-
059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1114 AM EDT MON JUL 16 2012
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO THE REGION TODAY
PROVIDING DRY...BUT CONTINUED VERY WARM CONDITIONS WHICH WILL
LAST THROUGH MID WEEK. A COLD FRONT WILL USHER IN A COOLER...AND
MUCH DRIER AIRMASS THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RESIDUAL LOW CLOUDS WILL CONTINUE TO BURN OFF UNDER THE STRONG MID
SUMMER SUN. AS WARMER AIR SURGES IN ALOFT...EXPECT CONTINUED
STABILIZATION. THE OPERATIONAL GFS...HIGH RES ARW AND HRRR ALL
SHOW POTENTIAL FOR A FEW CELLS TO POP OVER ERN ZONES IN THE
AFTERNOON. BUT NEW NAM AND 09Z SREF SHOW NO RAIN AFTER 18Z SO WILL
KEEP THE DRY LESS THAN 20% POP FORECAST WE HAVE AT THIS TIME.
M/CLEAR SKIES SHOULD PREVAIL EARLY TONIGHT WITH SOME INC IN
CLOUDS PSBL OVR THE NRN TIER MTNS TWD DAYBREAK AS LOW PRES TRACKS
EWD FM THE UPPER GRT LKS ACRS SRN ONT.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
SFC HIGH PRESSURE OFF TO OUR SOUTH...A BULLS-EYE OF PLUS 2-3 ST
DEVIATION 850 MB TEMPS / AROUND 22C/...AND A SLIGHTLY ANOMALOUS
WESTERLY 925-850 MB DOWNSLOPING WESTERLY FLOW WILL RESULT IN A PEAK
OF THE UPCOMING MINI HEAT WAVE TUESDAY AFTERNOON.
A HEAT ADVISORY /FOR TUESDAY FROM 16-23Z/ WAS ISSUED EARLIER THIS
MORNING AFTER COORDINATION WITH WFOS LWX AND PHI. MAX TEMPS WILL
REACH THE 90S IN ALL VALLEY LOCATIONS TUESDAY AFTERNOON...AND WILL
BE IN THE 95-97F RANGE ACROSS MUCH OF THE LOWER SUSQ VALLEY. HEAT
INDICES WILL PEAK AT 100-102F. EVEN ACROSS THE NRN AND WESTERN
MTNS...TEMPS WILL TOP OUT BETWEEN 87-90F.
AN EAST/WEST RIBBON OF WARM 700MB TEMPS AROUND 10C SHOULD CAP OFF
PRACTICALLY ALL CONVECTION TUESDAY AFTERNOON AND EVENING...BUT THE
SW AND FAR NRN MTNS WILL SEE SLIGHTLY COOLER MID LEVEL TEMPS...WHICH
COULD COMBINE WITH SOME OROGRAPHIC LIFT TO BREAK THE CAP AND YIELD A
FEW ISOLATED SHRA/TSRA AFTER 18Z.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MEAT OF THE WEATHER ACTION IN THE FORM OF HEAT...HUMIDITY...AND
AN APPROACHING POTENT COLD FRONT WILL OCCUR WEDNESDAY AFTERNOON AND
EVENING. THE COMBINATION OF THESE ELEMENTS WITH A BELT OF MDTLY
STRONG WESTERLY WINDS OF 30-35KTS AT 700 MB WILL CREATE A FAVORABLE
SETUP FOR STRONG TO POTENTIALLY SEVERE TSRA DURING THIS TIME PERIOD.
THE FRONTAL BOUNDARY WILL SAG SLOWLY TO THE SOUTH ACROSS THE STATE
LATE WEDNESDAY AND WED NIGHT.
A SECONDARY PUSH OF DEEPER/COOLER AIR WILL OCCUR THURSDAY WITH LLVL
WINDS VEERING ALL THE WAY AROUND TO THE NNE BY LATE IN THE DAY
THURSDAY.
THE SOUTHERN THIRD OF THE STATE STANDS THE BEST CHC TO SEE A SHOWER
/OR AFTERNOON TSRA/ THURSDAY AS THE NRN EDGE OF HIGH PWAT AIR /IN
THE 44-48MM RANGE/ WILL STAY NEAR THE MASON/DIXON LINE.
FOR LATER THURSDAY NIGHT THROUGH SATURDAY...A LARGE AREA OF
ANOMALOUSLY DRY PWAT AIR /IN THE 16-20MM RANGE/ SINKS SOUTH FROM
ONTARIO CANADA. THIS REFRESHING AIRMASS WILL SUPPLY US WITH LITTLE
OR NOR CHC FOR RAIN DURING THIS PORTION OF THE EXTENDED FCST PERIOD.
HIGH TEMPS WEDNESDAY /RANGING FROM THE U70S NW...TO 92-94F SE/ WILL
BE A GOOD 4-6 DEG F ABOVE NORMAL IN MOST LOCATIONS...EXCEPT FOR
PERHAPS PORTIONS OF THE NRN MTNS WHERE SHOWERS MAY SPREAD INTO THE
AREA DURING THE LATE MORNING AFTERNOON HOURS...ROBBING SEVERAL HOURS
OF HEATING.
AFTERNOON HIGH TEMPS WILL TREND DOWN GRADUALLY THURSDAY THROUGH
SATURDAY /BACK TO AROUND NORMAL/. NIGHTTIME LOWS WILL BECOME QUITE
CHILLY...WITH A FEW OF THE COLDER LOCATIONS NEAR AND TO THE EAST OF
KBFD SEEING A 48 OR 49F DAYBREAK TEMP.
FRIDAY AND SATURDAY WILL BE MAINLY DRY PER THE 00Z GEFS AND EC MODEL.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
EARLY MORNING FOG AND STRATUS WILL GIVE WAY TO VFR FLYING BY MID
DAY. AN ISOLATED SHRA/TSRA IS POSSIBLE OVR ERN SXNS...BUT POINT-
PROBABILITIES ARE ESTIMATED TO BE LESS THAN 20 PCT AT BEST...AND
THEREFORE WILL NOT MENTION IN TAFS.
HIGH PRES WILL PROVIDE VFR CONDS OVERNIGHT...WITH SOME PATCHY FOG
POSSIBLE TWD DAYBREAK TUES. THE NEXT CHANCE FOR SIGNIFICANT WX
WILL COME ON WEDNESDAY...AS AN APPROACHING COLD FRONT TRIGGERS SCT
STG-SVR TSTMS. HIGH PRES WILL DOMINATE THE WEATHER PATTERN FOR THE
END OF THE WEEK.
OUTLOOK...
TUE...VFR. NO SIG WX.
WED...SCT TSTM IMPACTS LKLY ASSOCD WITH COLD FROPA.
THU-FRI...VFR. NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR PAZ036-056-057-
059-063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
538 AM EDT MON JUL 16 2012
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO THE REGION TODAY
PROVIDING DRY...BUT VERY WARM CONDITIONS. HOT AIR WILL SURGE INTO
PENNSYLVANIA TUESDAY WITH HEAT INDICES AROUND THE 100 DEG MARK
ACROSS THE LOWER SUSQUEHANNA VALLEY AND ADJACENT SOUTHEASTERN PA. A
STRONG COLD FRONT WILL TRIGGER SHOWERS AND THUNDERSTORMS WEDNESDAY
AS IT PUSHES THROUGH THE STATE AND USHERS IN A COOLER...AND MUCH
DRIER AIRMASS THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLUSTER OF TSTMS ACRS NRN CAMBRIA COUNTY CONTINUES TO PUSH SEWD
EARLY THIS MORNING...PREVIOUSLY SHOWING NO SIGNS OF WEAKENING WITH
IR CLOUD TOPS COOLING TO AROUND -60C. RECENT RADAR AND IR SATL
TRENDS SUGGEST A SLIGHT WEAKENING IN THE LAST 30 MINUTES. THESE
STORMS...APPEAR TO BE ASSOCD WITH MINI S/W MCV-LIKE FEATURE ON SRN
END OF UPPER TROF/H5 VORT AXIS. PBZ RELAYED REPORT OF 1.5" OF HVY
RNFL IN 45 MINUTES AS THE STORMS WENT THRU PUNXY...BUT NO HAIL OR
WIND DESPITE DECENT BASE VELOCITIES 35-40KTS AND ELEVATED
REFLECTIVITY CORE ESPECIALLY FOR THIS TIME OF NIGHT. STORM IS LKLY
ELEVATED DUE TO DIURNALLY COOLED AND VERY MOIST/STABLE BLYR. MESO
MDLS HAVE NOT DONE WELL WITH THE CURRENT TSTM CLUSTER...AND THE
LATEST HRRR WEAKENS THIS FEATURE AS IT MOVES SWD INTO THE S-CENTRAL
MTNS BTWN 09-12Z. ASIDE FROM THIS AREA OF TSTMS...LOW CIGS/STRATUS
AND FOG ARE THE OTHER ISSUE FOR THE EARLY MORNING.
SFC HIGH WILL RIDGE EWD FM THE UPPER OH VLY INTO WRN PA BY EARLY
THIS AFTN AND KEEP THINGS DRY. HOWEVER OVR THE ERN 1/3RD OF THE
CWA...CAN`T RULE OUT AN ISOLD TSTM THIS AFTN NEAR LEE TROF AXIS BUT
OVERALL PROB IS BLW 20 PCT. A RELATIVE MINIMUM IN PWATS WILL BE
CENTERED OVR PA AT 17/00Z BEFORE INC AGAIN OVERNIGHT AS PATTERN
STARTS TO LOOK MORE LIKE RING OF FIRE. M/CLEAR SKIES SHOULD PREVAIL
EARLY TONIGHT WITH SOME INC IN CLOUDS PSBL OVR THE NW MTNS TWD
DAYBREAK AS WARM FNT PUSHES E/SEWD FM THE LWR GRT LKS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
SFC HIGH PRESSURE OFF TO OUR SOUTH...A BULLSEYE OF PLUS 2-3 ST
DEVIATION 850 MB TEMPS / AROUND 22C/...AND A SLIGHTLY ANOMALOUS
WESTERLY 925-850 MB DOWNSLOPING WESTERLY FLOW WILL RESULT IN A PEAK
OF THE UPCOMING MINI HEAT WAVE TUESDAY AFTERNOON.
A HEAT ADVISORY /FOR TUESDAY FROM 16-23Z/ WAS ISSUED EARLIER THIS
MORNING AFTER COORDINATION WITH WFOS LWX AND PHI. MAX TEMPS WILL
REACH THE 90S IN ALL VALLEY LOCATIONS TUESDAY AFTERNOON...AND WILL
BE IN THE 95-97F RANGE ACROSS MUCH OF THE LOWER SUSQ VALLEY. HEAT
INDICES WILL PEAK AT 100-102F. EVEN ACROSS THE NRN AND WESTERN
MTNS...TEMPS WILL TOP OUT BETWEEN 87-90F.
AN EAST/WEST RIBBON OF WARM 700MB TEMPS AROUND 10C SHOULD CAP OFF
PRACTICALLY ALL CONVECTION TUESDAY AFTERNOON AND EVENING...BUT THE
SW AND FAR NRN MTNS WILL SEE SLIGHTLY COOLER MID LEVEL TEMPS...WHICH
COULD COMBINE WITH SOME OROGRAPHIC LIFT TO BREAK THE CAP AND YIELD A
FEW ISOLATED SHRA/TSRA AFTER 18Z.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MEAT OF THE WEATHER ACTION IN THE FORM OF HEAT...HUMIDITY...AND
AN APPROACHING POTENT COLD FRONT WILL OCCUR WEDNESDAY AFTERNOON AND
EVENING. THE COMBINATION OF THESE ELEMENTS WITH A BELT OF MDTLY
STRONG WESTERLY WINDS OF 30-35KTS AT 700 MB WILL CREATE A FAVORABLE
SETUP FOR STRONG TO POTENTIALLY SEVERE TSRA DURING THIS TIME PERIOD.
THE FRONTAL BOUNDARY WILL SAG SLOWLY TO THE SOUTH ACROSS THE STATE
LATE WEDNESDAY AND WED NIGHT.
A SECONDARY PUSH OF DEEPER/COOLER AIR WILL OCCUR THURSDAY WITH LLVL
WINDS VEERING ALL THE WAY AROUND TO THE NNE BY LATE IN THE DAY
THURSDAY.
THE SOUTHERN THIRD OF THE STATE STANDS THE BEST CHC TO SEE A SHOWER
/OR AFTERNOON TSRA/ THURSDAY AS THE NRN EDGE OF HIGH PWAT AIR /IN
THE 44-48MM RANGE/ WILL STAY NEAR THE MASON/DIXON LINE.
FOR LATER THURSDAY NIGHT THROUGH SATURDAY...A LARGE AREA OF
ANOMALOUSLY DRY PWAT AIR /IN THE 16-20MM RANGE/ SINKS SOUTH FROM
ONTARIO CANADA. THIS REFRESHING AIRMASS WILL SUPPLY US WITH LITTLE
OR NOR CHC FOR RAIN DURING THIS PORTION OF THE EXTENDED FCST PERIOD.
HIGH TEMPS WEDNESDAY /RANGING FROM THE U70S NW...TO 92-94F SE/ WILL
BE A GOOD 4-6 DEG F ABOVE NORMAL IN MOST LOCATIONS...EXCEPT FOR
PERHAPS PORTIONS OF THE NRN MTNS WHERE SHOWERS MAY SPREAD INTO THE
AREA DURING THE LATE MORNING AFTERNOON HOURS...ROBBING SEVERAL HOURS
OF HEATING.
AFTERNOON HIGH TEMPS WILL TREND DOWN GRADUALLY THURSDAY THROUGH
SATURDAY /BACK TO AROUND NORMAL/. NIGHTTIME LOWS WILL BECOME QUITE
CHILLY...WITH A FEW OF THE COLDER LOCATIONS NEAR AND TO THE EAST OF
KBFD SEEING A 48 OR 49F DAYBREAK TEMP.
FRIDAY AND SATURDAY WILL BE MAINLY DRY PER THE 00Z GEFS AND EC MODEL.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
EARLY MORNING FOG AND STRATUS /MVFR OF LIFR CONDS/ WILL GIVE WAY
TO VFR FLYING BY LATE MORNING/EARLY AFTN. AN ISOLATED SHRA/TSRA
IS POSSIBLE OVR ERN SXNS...BUT POINT-PROBABILITIES ARE 20 PCT AT
BEST AND THEREFORE WILL NOT MENTION IN TAFS. HIGH PRES WILL
PROVIDE MAINLY VFR CONDS OVERNIGHT...WITH SOME PATCHY FOG POSSIBLE
TWD DAYBREAK TUES. THE NEXT CHANCE FOR SIGNIFICANT WX WILL COME
ON WEDNESDAY...AS AN APPROACHING COLD FRONT TRIGGERS SCT STG TO
POSSIBLY SVR SHRA/TSRA. HIGH PRES WILL DOMINATE THE WEATHER
PATTERN FOR THE END OF THE WEEK.
OUTLOOK...
TUE...VFR. NO SIG WX.
WED...SCT TSTM IMPACTS LKLY ASSOCD WITH COLD FROPA.
THU-FRI...VFR. NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR PAZ036-056-057-
059-063>066.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
459 AM EDT MON JUL 16 2012
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO THE REGION TODAY
PROVIDING DRY...BUT VERY WARM CONDITIONS. HOT AIR WILL SURGE INTO
PENNSYLVANIA TUESDAY WITH HEAT INDICES AROUND THE 100 DEG MARK
ACROSS THE LOWER SUSQUEHANNA VALLEY AND ADJACENT SOUTHEASTERN PA. A
STRONG COLD FRONT WILL TRIGGER SHOWERS AND THUNDERSTORMS WEDNESDAY
AS IT PUSHES THROUGH THE STATE AND USHERS IN A COOLER...AND MUCH
DRIER AIRMASS THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLUSTER OF TSTMS ACRS NRN CAMBRIA COUNTY CONTINUES TO PUSH SEWD
EARLY THIS MORNING...PREVIOUSLY SHOWING NO SIGNS OF WEAKENING WITH
IR CLOUD TOPS COOLING TO AROUND -60C. RECENT RADAR AND IR SATL
TRENDS SUGGEST A SLIGHT WEAKENING IN THE LAST 30 MINUTES. THESE
STORMS...APPEAR TO BE ASSOCD WITH MINI S/W MCV-LIKE FEATURE ON SRN
END OF UPPER TROF/H5 VORT AXIS. PBZ RELAYED REPORT OF 1.5" OF HVY
RNFL IN 45 MINUTES AS THE STORMS WENT THRU PUNXY...BUT NO HAIL OR
WIND DESPITE DECENT BASE VELOCITIES 35-40KTS AND ELEVATED
REFLECTIVITY CORE ESPECIALLY FOR THIS TIME OF NIGHT. STORM IS LKLY
ELEVATED DUE TO DIURNALLY COOLED AND VERY MOIST/STABLE BLYR. MESO
MDLS HAVE NOT DONE WELL WITH THE CURRENT TSTM CLUSTER...AND THE
LATEST HRRR WEAKENS THIS FEATURE AS IT MOVES SWD INTO THE S-CENTRAL
MTNS BTWN 09-12Z. ASIDE FROM THIS AREA OF TSTMS...LOW CIGS/STRATUS
AND FOG ARE THE OTHER ISSUE FOR THE EARLY MORNING.
SFC HIGH WILL RIDGE EWD FM THE UPPER OH VLY INTO WRN PA BY EARLY
THIS AFTN AND KEEP THINGS DRY. HOWEVER OVR THE ERN 1/3RD OF THE
CWA...CAN`T RULE OUT AN ISOLD TSTM THIS AFTN NEAR LEE TROF AXIS BUT
OVERALL PROB IS BLW 20 PCT. A RELATIVE MINIMUM IN PWATS WILL BE
CENTERED OVR PA AT 17/00Z BEFORE INC AGAIN OVERNIGHT AS PATTERN
STARTS TO LOOK MORE LIKE RING OF FIRE. M/CLEAR SKIES SHOULD PREVAIL
EARLY TONIGHT WITH SOME INC IN CLOUDS PSBL OVR THE NW MTNS TWD
DAYBREAK AS WARM FNT PUSHES E/SEWD FM THE LWR GRT LKS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
SFC HIGH PRESSURE OFF TO OUR SOUTH...A BULLSEYE OF PLUS 2-3 ST
DEVIATION 850 MB TEMPS / AROUND 22C/...AND A SLIGHTLY ANOMALOUS
WESTERLY 925-850 MB DOWNSLOPING WESTERLY FLOW WILL RESULT IN A PEAK
OF THE UPCOMING MINI HEAT WAVE TUESDAY AFTERNOON.
A HEAT ADVISORY /FOR TUESDAY FROM 16-23Z/ WAS ISSUED EARLIER THIS
MORNING AFTER COORDINATION WITH WFOS LWX AND PHI. MAX TEMPS WILL
REACH THE 90S IN ALL VALLEY LOCATIONS TUESDAY AFTERNOON...AND WILL
BE IN THE 95-97F RANGE ACROSS MUCH OF THE LOWER SUSQ VALLEY. HEAT
INDICES WILL PEAK AT 100-102F. EVEN ACROSS THE NRN AND WESTERN
MTNS...TEMPS WILL TOP OUT BETWEEN 87-90F.
AN EAST/WEST RIBBON OF WARM 700MB TEMPS AROUND 10C SHOULD CAP OFF
PRACTICALLY ALL CONVECTION TUESDAY AFTERNOON AND EVENING...BUT THE
SW AND FAR NRN MTNS WILL SEE SLIGHTLY COOLER MID LEVEL TEMPS...WHICH
COULD COMBINE WITH SOME OROGRAPHIC LIFT TO BREAK THE CAP AND YIELD A
FEW ISOLATED SHRA/TSRA AFTER 18Z.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MEAT OF THE WEATHER ACTION IN THE FORM OF HEAT...HUMIDITY...AND
AN APPROACHING POTENT COLD FRONT WILL OCCUR WEDNESDAY AFTERNOON AND
EVENING. THE COMBINATION OF THESE ELEMENTS WITH A BELT OF MDTLY
STRONG WESTERLY WINDS OF 30-35KTS AT 700 MB WILL CREATE A FAVORABLE
SETUP FOR STRONG TO POTENTIALLY SEVERE TSRA DURING THIS TIME PERIOD.
THE FRONTAL BOUNDARY WILL SAG SLOWLY TO THE SOUTH ACROSS THE STATE
LATE WEDNESDAY AND WED NIGHT.
A SECONDARY PUSH OF DEEPER/COOLER AIR WILL OCCUR THURSDAY WITH LLVL
WINDS VEERING ALL THE WAY AROUND TO THE NNE BY LATE IN THE DAY
THURSDAY.
THE SOUTHERN THIRD OF THE STATE STANDS THE BEST CHC TO SEE A SHOWER
/OR AFTERNOON TSRA/ THURSDAY AS THE NRN EDGE OF HIGH PWAT AIR /IN
THE 44-48MM RANGE/ WILL STAY NEAR THE MASON/DIXON LINE.
FOR LATER THURSDAY NIGHT THROUGH SATURDAY...A LARGE AREA OF
ANOMALOUSLY DRY PWAT AIR /IN THE 16-20MM RANGE/ SINKS SOUTH FROM
ONTARIO CANADA. THIS REFRESHING AIRMASS WILL SUPPLY US WITH LITTLE
OR NOR CHC FOR RAIN DURING THIS PORTION OF THE EXTENDED FCST PERIOD.
HIGH TEMPS WEDNESDAY /RANGING FROM THE U70S NW...TO 92-94F SE/ WILL
BE A GOOD 4-6 DEG F ABOVE NORMAL IN MOST LOCATIONS...EXCEPT FOR
PERHAPS PORTIONS OF THE NRN MTNS WHERE SHOWERS MAY SPREAD INTO THE
AREA DURING THE LATE MORNING AFTERNOON HOURS...ROBBING SEVERAL HOURS
OF HEATING.
AFTERNOON HIGH TEMPS WILL TREND DOWN GRADUALLY THURSDAY THROUGH
SATURDAY /BACK TO AROUND NORMAL/. NIGHTTIME LOWS WILL BECOME QUITE
CHILLY...WITH A FEW OF THE COLDER LOCATIONS NEAR AND TO THE EAST OF
KBFD SEEING A 48 OR 49F DAYBREAK TEMP.
FRIDAY AND SATURDAY WILL BE MAINLY DRY PER THE 00Z GEFS AND EC MODEL.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
REDUCED VSBYS IN PATCHY 2-3SM IS POSSIBLE EARLY TODAY...AND
SOME LOW CLOUDINESS MAY FORM...ESPECIALLY ACROSS THE WESTERN
HIGHLANDS /JST AND BFD/ AS THE LLVL FLOW BECOMES LIGHT WESTERLY AND
UPSLOPE.
THE BALANCE OF TODAY WILL GENERALLY BE VFR AFTER ANY MORNING FOG
AND LOW CLOUDS BURN OFF. AN ISOLATED AFTN SHRA/TSRA IS
POSSIBLE...BUT MAINLY ACROSS THE SOUTH.
THE NEXT CHANCE FOR SIGNIFICANT WX WILL COME ON WEDNESDAY...AS AN
APPROACHING COLD FRONT TRIGGERS SCT SHRA/TSRA.
OUTLOOK...
TUE...VFR.
WED...SCT TSTM IMPACTS LKLY ASSOCD WITH COLD FROPA.
THU-FRI...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR PAZ036-056-057-
059-063>066.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT
AVIATION...LAMBERT/STEINBUGL
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1052 PM CDT MON JUL 16 2012
.DISCUSSION.../ISSUED AT 852 PM CDT/
ISOLATED CONVECTION HAS DEVELOPED ALONG A WEAK CONVERGENCE BOUNDARY
THAT REMAINS RATHER STATIONARY FROM NEAR GREGORY COUNTY TO SIOUX
FALLS TO WINDOM. THE MORE ROBUST CONVECTION IS VERY SLOWLY TRACKING
NORTHEAST JUST WEST AND SOUTHWEST OF THE FORECAST AREA WHERE A MINOR
WAVE HAS EJECTED OUT OF WYOMING AND HAS MOVED INTO NORTH CENTRAL
NEBRASKA. THIS WILL LIKELY REMAIN THE FOCUS OF THUNDERSTORM ACTIVITY
THROUGH THE EVENING AS IT SLOWLY SPREADS INTO THE JAMES RIVER AREA
WHILE ANY DEVELOPMENT ALONG THE BOUNDARY TO THE EAST WILL REMAIN
ISOLATED AND VERY SHORT LIVED IN NATURE. OVERNIGHT...EXPECT
PRECIPITATION CHANCES TO SPREAD EAST INTO AREAS ALONG AND NORTH OF
I90...ALTHOUGH THE LOSS OF DAYTIME HEATING COULD ALLOW CONVECTION TO
DIMINISH PAST MIDNIGHT. ALTHOUGH LAPSE RATES ARE QUITE HIGH...SHEAR
REMAINS QUITE LOW THIS EVENING WHICH WILL KEEP THE SEVERE WEATHER
POTENTIAL MINIMAL...ESPECIALLY AFTER MIDNIGHT.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH 00Z THURSDAY. DIFFICLUT
FORECAST WITH CHANCES OF SCATTERED CONVECTION THROUGH THE FORECAST
PERIOD...WITH LITTLE IN THE WAY OF FORCING TO FOCUS ON. WITH LOW
CONFIDENCE IN AREAL COVERAGE AND TIMING...HAVE OPTED FOR CONVECTION
FREE TAFS WITH THE POTENTIAL FOR AMENDMENTS. BEST CHANCES FOR
THUNDERSTORMS THROUGH 14Z WILL BE WEST OF THE JAMES RIVER VALLEY
INCLUDING KHON. THEREAFTER...POTENTIAL FOR STORMS SHIFTS EAST AFTER
00Z/19TH EAST OF I-29.
&&
.PREV DISCUSSION.../ISSUED AT 407 PM CDT/
A HOT AND HUMID DAY CURRENTLY UNDERWAY WITH TEMPERATURES WELL INTO
THE 90S AND DEWPOINTS IN THE 60S. FRONTAL BOUNDARY CURRENTLY
SITUATED AROUND HIGHWAY 14...SHOULD SLOWLY MOVE SOUTH THIS EVENING.
ATMOSPHERE REMAINS CAPPED OVER THE AREA...DESPITE MLCAPE OVER 3500
J/KG NORTH OF THE BOUNDARY. INTERESTINGLY...CU HAS FORMED FURTHER
SOUTHWEST ACROSS NEBRASKA AND NEAR THE MISSOURI RIVER. IT SEEMS
LIKELY THE ATMOSPHERE HAS MIXED ALL THE WAY THROUGH THE CAP IN THESE
AREAS. THIS IS EVIDENT BY THE LOWER DEWPOINTS IN THE 40S AND 50S IN
THESE AREAS. SO WHILE THIS MIXING HAS ERODED THE CAP...IT HAS ALSO
ERODED MUCH OF THE INSTABILITY...HENCE THE LACK OF OF SIGNIFICANT
UPGROWTH. EXPECT THIS TO CONTINUE TO BE THE CASE THROUGH THE EVENING
WITH ONLY AN ISOLATED SHOWER OR THUNDERSTORM WITH THAT CU. SEEMS
MORE PROBABLE THAT CONVECTION DEVELOPS WEST OF OUR CWA ALONG THE
OTHER BOUNDARY. THESE STORMS SHOULD PROPAGATE TOWARDS OUR WESTERN
CWA THIS EVENING...POSSIBLY IMPACTING LOCATIONS WEST OF THE JAMES
RIVER. WILL ALSO HAVE TO MONITOR DEVELOPMENT ALONG THE BACKDOOR
BOUNDARY AS IT DROPS SOUTH THROUGH THE CWA. HRRR AND NAM SEEM TO BE
OVERDOING CONVECTION CHANCES WITH THIS BOUNDARY...BUT CANT RULE OUT
A FEW STORMS WITH ABUNDANT LOW LEVEL MOISTURE POOLING AROUND THE
BOUNDARY.
UPPER LEVEL FORCING AND DEEPER MOISTURE SHOULD MOVE ACROSS THE CWA
AFTER MIDNIGHT TONIGHT. SO EVEN IF NO SURFACE CONVECTION GETS GOING
THIS EVENING...SHOULD HAVE A CHANCE OF ELEVATED STORMS LATER TONIGHT
NORTH OF THE BOUNDARY IN AREA OF LOW LEVEL THETAE ADVECTION. THIS
CONVECTION WILL LIKELY STAY GENERALLY FROM HIGHWAY 34 AND POINTS
NORTH...WITH THE ECMWF ACTUALLY KEEPING IT NORTH OF THE CWA...SO DID
NOT GO ANY HIGHER THAT 30 TO 40 POPS. LOWS TONIGHT WILL STAY
MILD...GENERALLY LOW TO MID 70S.
WEDNESDAY WILL BE ANOTHER HOT ONE ACROSS MUCH OF THE REGION...WITH
HIGHS IN THE 90S EVERYWHERE BUT SOUTHWEST MINNESOTA. DEWPOINTS WILL
LIKELY BE HIGHER THAN TODAY...ESPECIALLY ALONG AND EAST OF
INTERSTATE 29...WHERE VALUES IN THE LOW 70S ARE LIKELY. THIS WILL
MAKE FOR ANOTHER DAY OF VERY HIGH HEAT INDICES...SO WENT AHEAD AND
ISSUED A HEAT ADVISORY FOR AREAS MOST LIKELY TO HAVE A HEAT INDEX
OVER 100. THE ABOVE MENTIONED WAVE WILL CONTINUE TO PUSH EAST
WEDNESDAY. BY THIS TIME BEST CHANCE OF CONVECTION SHOULD BE
GENERALLY EAST OF INTERSTATE 29. AREAS TO THE WEST WILL BE UNDER AN
AREA OF LARGE SCALE SUBSIDENCE AND SHOULD REMAIN CAPPED. INITIAL
CONVECTION SHOULD EB ELEVATED...BUT IF THE WAVE MOVES SLOW ENOUGH WE
SHOULD SEE A TRANSITION TO SURFACE BASED CONVECTION BY AFTERNOON. IF
THIS HAPPENS...WOULD BE MOST LIKELY OVER SOUTHWEST MINNESOTA AND
PORTIONS OF NORTHWEST IOWA. COULD SEE A COUPLE SEVERE STORMS DURING
THE AFTERNOON...WITH A BIT BETTER SHEAR EXPECTED. /CHENARD
ANY CONVECTION THAT DEVELOPS ON WEDNESDAY AFTERNOON MAY LINGER INTO
THE EVENING ACROSS NW IOWA AND SW MN. MODELS DO SHOW A SECOND WEAK
WAVE MOVING SOUTHEAST ACROSS MINNESOTA ON WEDNESDAY NIGHT. THIS MAY
RESULT IN MORE STORMS DEVELOPING INTO SOUTHWEST MINNESOTA AFTER
SUNSET. AGAIN...ANY STORM DEVELOPMENT WILL BE SOMEWHAT ISOLATED. ANY
STORMS SHOULD MOVE EAST BY DAWN ON THURSDAY. OTHERWISE...EASTERLY
FLOW IS EXPECTED ACROSS THE AREA THROUGH THE EVENING. THIS WILL
BRING A BIT COOLER AIR INTO THE AREA...ALLOWING LOWS TO DROP BELOW
70 DEGREES IN SW MN AND BETWEEN 70 AND 75 DEGREES ELSEWHERE.
THE UPPER LEVEL RIDGE WILL BUILD ACROSS THE AREA THURSDAY AND
FRIDAY. AS HEIGHTS RISE AT 500 MB...THE SURFACE RIDGE WILL
STRENGTHEN OVER THE GREAT LAKES. THIS WILL KEEP WINDS OUT OF THE
EAST DURING THE DAY. HOWEVER...MOSTLY SUNNY SKIES ARE EXPECTED AND
THE AIR MASS REMAINS VERY WARM. TEMPERATURES ARE EXPECTED TO BE
SIMILAR TO WEDNESDAY FROM AROUND 90 IN SOUTHWEST MINNESOTA TO AROUND
100 IN SOUTH CENTRAL SD. CLEAR SKIES AND RELATIVELY LIGHT WINDS ARE
AGAIN EXPECTED THURSDAY NIGHT. LOWS WILL BE SIMILAR TO WEDNESDAY
NIGHT FROM THE UPPER 60S IN SOUTHWEST MINNESOTA TO 70 TO 75
ELSEWHERE.
THE REMAINDER OF THE FORECAST WILL REALLY FOCUS ON THE RETURN OF THE
HEAT. OVERALL...THE GFS AND ECMWF ARE VERY SIMILAR ON THE STRENGTH
AND DURATION OF THIS RIDGE. BY EARLY NEXT WEEK THEY BOTH HAVE A
FAIRLY STRONG WAVE MOVE ALONG THE CANADIAN BORDER. THEY ALSO SHOW
THE RIDGE VERY SLOWLY BREAKING DOWN BY TUESDAY OR WEDNESDAY ALTHOUGH
OVERALL THE RIDGE REMAINS OVER THE CENTRAL UNITED STATES THROUGH THE
MIDDLE NEXT WEEK SO NO SIGNIFICANT BREAK IN THE HEAT IS REALLY
EXPECTED FOR THE NEXT 7 DAYS. IN TERMS OF PRECIPITATION...BOTH
MODELS SHOW A WEAK SYSTEM MOVING ACROSS THE DAKOTAS ON SUNDAY BUT IT
REMAINS VERY WARM ALOFT OVER SOUTHERN SOUTH DAKOTA AND THE LARGE
SCALE FORCING FOR ASCENT REMAIN CLOSER TO THE CANADIAN BORDER. SO
WHILE WE HAVE KEPT A 20 TO 30 PERCENT CHANCE OF PRECIPITATION FOR
SUNDAY AND SUNDAY NIGHT...THE CONVECTION DOES NOT LOOK TO BE
WIDESPREAD AT THIS POINT AND MOST AREAS WILL LIKELY NOT SEE ANY RAIN
FROM THIS SYSTEM. GOING INTO NEXT WEEK...THERE DOES NOT APPEAR TO BE
ANY REAL CHANCE OF WIDESPREAD RAINFALL INTO THE MIDDLE OF NEXT
WEEK.
LOOKING AT DAY TO DAY...FRIDAY WILL SEE THE HEAT SPREAD INTO THE
JAMES VALLEY WITH HIGHS AROUND 100. TO THE EAST HIGHS WILL RANGE
FROM THE LOWER 90S AROUND HIGHWAY 71 IN MINNESOTA AND IOWA...TO THE
MID TO UPPER 90S IN THE REMAINDER OF SOUTHEAST SOUTH DAKOTA. AFTER
FRIDAY...LOWS SATURDAY MORNING THROUGH TUESDAY MORNING WILL BE IN
THE LOWER TO MID 70S. HIGHS ON SATURDAY AND SUNDAY WILL BE SIMILAR
TO FRIDAY GENERALLY IN THE LOWER 90S IN SOUTHEAST MINNESOTA TO AT OR
ABOVE 100 WEST OF THE JAMES RIVER. IF THERE ARE LESS CLOUDS OR THE
SURFACE HIGH RETREATS MORE QUICKLY...TEMPERATURES BOTH DAYS COULD BE
2 TO 5 DEGREES WARMER...RESULTING IN HIGHS APPROACHING 100 OVER MUCH
OF THE AREA. A WEAK BOUNDARY WILL GO THROUGH SUNDAY EVENING AND
THIS MAY BRING A BIT COOLER AIR INTO THE AREA. HOWEVER...HOW COOL
THE AIR WILL BE AND HOW LONG IT REMAINS IS VERY UNCERTAIN AT THIS
POINT. FOR NOW...FORECAST HIGHS ONLY 3 TO 5 DEGREES COOLER THAN THE
WEEKEND WHICH MEANS 90S LOOK TO PERSIST THROUGH TUESDAY. IF THE
FRONT RETREATS BACK TO THE NORTH MORE QUICKLY...PER THE 12Z
ECMWF...HIGHS COULD BE BACK OVER 100 DEGREES IN PARTS OF THE AREA BY
TUESDAY./SCHUMACHER
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
852 PM CDT MON JUL 16 2012
.DISCUSSION.../ISSUED AT 852 PM CDT/
ISOLATED CONVECTION HAS DEVELOPED ALONG A WEAK CONVERGENCE BOUNDARY
THAT REMAINS RATHER STATIONARY FROM NEAR GREGORY COUNTY TO SIOUX
FALLS TO WINDOM. THE MORE ROBUST CONVECTION IS VERY SLOWLY TRACKING
NORTHEAST JUST WEST AND SOUTHWEST OF THE FORECAST AREA WHERE A MINOR
WAVE HAS EJECTED OUT OF WYOMING AND HAS MOVED INTO NORTH CENTRAL
NEBRASKA. THIS WILL LIKELY REMAIN THE FOCUS OF THUNDERSTORM ACTIVITY
THROUGH THE EVENING AS IT SLOWLY SPREADS INTO THE JAMES RIVER AREA
WHILE ANY DEVELOPMENT ALONG THE BOUNDARY TO THE EAST WILL REMAIN
ISOLATED AND VERY SHORT LIVED IN NATURE. OVERNIGHT...EXPECT
PRECIPITATION CHANCES TO SPREAD EAST INTO AREAS ALONG AND NORTH OF
I90...ALTHOUGH THE LOSS OF DAYTIME HEATING COULD ALLOW CONVECTION TO
DIMINISH PAST MIDNIGHT. ALTHOUGH LAPSE RATES ARE QUITE HIGH...SHEAR
REMAINS QUITE LOW THIS EVENING WHICH WILL KEEP THE SEVERE WEATHER
POTENTIAL MINIMAL...ESPECIALLY AFTER MIDNIGHT.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH 00Z THURSDAY. FRONT
SLOWLY PROGRESSING SOUTH ACROSS THE CWA AT THIS TIME. ISOLATED
SURFACE BASED CONVECTION DEVELOPING ACROSS THE AREA...BUT CONFIDENCE
IN IT REACHING ANY OF THE PARTICULAR AIRPORTS LOW ENOUGH THAT IT WAS
LEFT OUT OF THE FORECAST. THERE IS SOME ELEVATED CONVERGENCE TONIGHT
WITH THE I-90 CORRIDOR LOCATED ON THE NOSE OF THE LOW LEVEL JET.
POTENTIAL FOR STORMS TO AFFECT I-90 AND HIGHWAY 14 CORRIDOR BUT
AGAIN CONFIDENCE IS TOO LOW TO INCLUDE IN THE FORECAST. SMALL CHANCE
A FEW OF THESE STORMS FORM FURTHER SOUTH WEDNESDAY MORNING AND EARLY
AFTERNOON CLOSER TO KFSD AND KSUX...BUT PROBABILITY AND TIMING
CONFIDENCE TOO LOW TO INCLUDE IN TAF. MODEL SOUNDINGS ARE QUICK TO
GO CONVECTIVE...BUT APPEAR TO BE TOO QUICK TO BREAK DOWN THE
ELEVATED INVERSION ALOFT. IF CONVECTION WAS ABLE TO DEVELOP BEST
CHANCES WOULD BE IN THE 17-21Z TIMEFRAME FOR INITIATION.
&&
.PREV DISCUSSION.../ISSUED AT 407 PM CDT/
A HOT AND HUMID DAY CURRENTLY UNDERWAY WITH TEMPERATURES WELL INTO
THE 90S AND DEWPOINTS IN THE 60S. FRONTAL BOUNDARY CURRENTLY
SITUATED AROUND HIGHWAY 14...SHOULD SLOWLY MOVE SOUTH THIS EVENING.
ATMOSPHERE REMAINS CAPPED OVER THE AREA...DESPITE MLCAPE OVER 3500
J/KG NORTH OF THE BOUNDARY. INTERESTINGLY...CU HAS FORMED FURTHER
SOUTHWEST ACROSS NEBRASKA AND NEAR THE MISSOURI RIVER. IT SEEMS
LIKELY THE ATMOSPHERE HAS MIXED ALL THE WAY THROUGH THE CAP IN THESE
AREAS. THIS IS EVIDENT BY THE LOWER DEWPOINTS IN THE 40S AND 50S IN
THESE AREAS. SO WHILE THIS MIXING HAS ERODED THE CAP...IT HAS ALSO
ERODED MUCH OF THE INSTABILITY...HENCE THE LACK OF OF SIGNIFICANT
UPGROWTH. EXPECT THIS TO CONTINUE TO BE THE CASE THROUGH THE EVENING
WITH ONLY AN ISOLATED SHOWER OR THUNDERSTORM WITH THAT CU. SEEMS
MORE PROBABLE THAT CONVECTION DEVELOPS WEST OF OUR CWA ALONG THE
OTHER BOUNDARY. THESE STORMS SHOULD PROPAGATE TOWARDS OUR WESTERN
CWA THIS EVENING...POSSIBLY IMPACTING LOCATIONS WEST OF THE JAMES
RIVER. WILL ALSO HAVE TO MONITOR DEVELOPMENT ALONG THE BACKDOOR
BOUNDARY AS IT DROPS SOUTH THROUGH THE CWA. HRRR AND NAM SEEM TO BE
OVERDOING CONVECTION CHANCES WITH THIS BOUNDARY...BUT CANT RULE OUT
A FEW STORMS WITH ABUNDANT LOW LEVEL MOISTURE POOLING AROUND THE
BOUNDARY.
UPPER LEVEL FORCING AND DEEPER MOISTURE SHOULD MOVE ACROSS THE CWA
AFTER MIDNIGHT TONIGHT. SO EVEN IF NO SURFACE CONVECTION GETS GOING
THIS EVENING...SHOULD HAVE A CHANCE OF ELEVATED STORMS LATER TONIGHT
NORTH OF THE BOUNDARY IN AREA OF LOW LEVEL THETAE ADVECTION. THIS
CONVECTION WILL LIKELY STAY GENERALLY FROM HIGHWAY 34 AND POINTS
NORTH...WITH THE ECMWF ACTUALLY KEEPING IT NORTH OF THE CWA...SO DID
NOT GO ANY HIGHER THAT 30 TO 40 POPS. LOWS TONIGHT WILL STAY
MILD...GENERALLY LOW TO MID 70S.
WEDNESDAY WILL BE ANOTHER HOT ONE ACROSS MUCH OF THE REGION...WITH
HIGHS IN THE 90S EVERYWHERE BUT SOUTHWEST MINNESOTA. DEWPOINTS WILL
LIKELY BE HIGHER THAN TODAY...ESPECIALLY ALONG AND EAST OF
INTERSTATE 29...WHERE VALUES IN THE LOW 70S ARE LIKELY. THIS WILL
MAKE FOR ANOTHER DAY OF VERY HIGH HEAT INDICES...SO WENT AHEAD AND
ISSUED A HEAT ADVISORY FOR AREAS MOST LIKELY TO HAVE A HEAT INDEX
OVER 100. THE ABOVE MENTIONED WAVE WILL CONTINUE TO PUSH EAST
WEDNESDAY. BY THIS TIME BEST CHANCE OF CONVECTION SHOULD BE
GENERALLY EAST OF INTERSTATE 29. AREAS TO THE WEST WILL BE UNDER AN
AREA OF LARGE SCALE SUBSIDENCE AND SHOULD REMAIN CAPPED. INITIAL
CONVECTION SHOULD EB ELEVATED...BUT IF THE WAVE MOVES SLOW ENOUGH WE
SHOULD SEE A TRANSITION TO SURFACE BASED CONVECTION BY AFTERNOON. IF
THIS HAPPENS...WOULD BE MOST LIKELY OVER SOUTHWEST MINNESOTA AND
PORTIONS OF NORTHWEST IOWA. COULD SEE A COUPLE SEVERE STORMS DURING
THE AFTERNOON...WITH A BIT BETTER SHEAR EXPECTED. /CHENARD
ANY CONVECTION THAT DEVELOPS ON WEDNESDAY AFTERNOON MAY LINGER INTO
THE EVENING ACROSS NW IOWA AND SW MN. MODELS DO SHOW A SECOND WEAK
WAVE MOVING SOUTHEAST ACROSS MINNESOTA ON WEDNESDAY NIGHT. THIS MAY
RESULT IN MORE STORMS DEVELOPING INTO SOUTHWEST MINNESOTA AFTER
SUNSET. AGAIN...ANY STORM DEVELOPMENT WILL BE SOMEWHAT ISOLATED. ANY
STORMS SHOULD MOVE EAST BY DAWN ON THURSDAY. OTHERWISE...EASTERLY
FLOW IS EXPECTED ACROSS THE AREA THROUGH THE EVENING. THIS WILL
BRING A BIT COOLER AIR INTO THE AREA...ALLOWING LOWS TO DROP BELOW
70 DEGREES IN SW MN AND BETWEEN 70 AND 75 DEGREES ELSEWHERE.
THE UPPER LEVEL RIDGE WILL BUILD ACROSS THE AREA THURSDAY AND
FRIDAY. AS HEIGHTS RISE AT 500 MB...THE SURFACE RIDGE WILL
STRENGTHEN OVER THE GREAT LAKES. THIS WILL KEEP WINDS OUT OF THE
EAST DURING THE DAY. HOWEVER...MOSTLY SUNNY SKIES ARE EXPECTED AND
THE AIR MASS REMAINS VERY WARM. TEMPERATURES ARE EXPECTED TO BE
SIMILAR TO WEDNESDAY FROM AROUND 90 IN SOUTHWEST MINNESOTA TO AROUND
100 IN SOUTH CENTRAL SD. CLEAR SKIES AND RELATIVELY LIGHT WINDS ARE
AGAIN EXPECTED THURSDAY NIGHT. LOWS WILL BE SIMILAR TO WEDNESDAY
NIGHT FROM THE UPPER 60S IN SOUTHWEST MINNESOTA TO 70 TO 75
ELSEWHERE.
THE REMAINDER OF THE FORECAST WILL REALLY FOCUS ON THE RETURN OF THE
HEAT. OVERALL...THE GFS AND ECMWF ARE VERY SIMILAR ON THE STRENGTH
AND DURATION OF THIS RIDGE. BY EARLY NEXT WEEK THEY BOTH HAVE A
FAIRLY STRONG WAVE MOVE ALONG THE CANADIAN BORDER. THEY ALSO SHOW
THE RIDGE VERY SLOWLY BREAKING DOWN BY TUESDAY OR WEDNESDAY ALTHOUGH
OVERALL THE RIDGE REMAINS OVER THE CENTRAL UNITED STATES THROUGH THE
MIDDLE NEXT WEEK SO NO SIGNIFICANT BREAK IN THE HEAT IS REALLY
EXPECTED FOR THE NEXT 7 DAYS. IN TERMS OF PRECIPITATION...BOTH
MODELS SHOW A WEAK SYSTEM MOVING ACROSS THE DAKOTAS ON SUNDAY BUT IT
REMAINS VERY WARM ALOFT OVER SOUTHERN SOUTH DAKOTA AND THE LARGE
SCALE FORCING FOR ASCENT REMAIN CLOSER TO THE CANADIAN BORDER. SO
WHILE WE HAVE KEPT A 20 TO 30 PERCENT CHANCE OF PRECIPITATION FOR
SUNDAY AND SUNDAY NIGHT...THE CONVECTION DOES NOT LOOK TO BE
WIDESPREAD AT THIS POINT AND MOST AREAS WILL LIKELY NOT SEE ANY RAIN
FROM THIS SYSTEM. GOING INTO NEXT WEEK...THERE DOES NOT APPEAR TO BE
ANY REAL CHANCE OF WIDESPREAD RAINFALL INTO THE MIDDLE OF NEXT
WEEK.
LOOKING AT DAY TO DAY...FRIDAY WILL SEE THE HEAT SPREAD INTO THE
JAMES VALLEY WITH HIGHS AROUND 100. TO THE EAST HIGHS WILL RANGE
FROM THE LOWER 90S AROUND HIGHWAY 71 IN MINNESOTA AND IOWA...TO THE
MID TO UPPER 90S IN THE REMAINDER OF SOUTHEAST SOUTH DAKOTA. AFTER
FRIDAY...LOWS SATURDAY MORNING THROUGH TUESDAY MORNING WILL BE IN
THE LOWER TO MID 70S. HIGHS ON SATURDAY AND SUNDAY WILL BE SIMILAR
TO FRIDAY GENERALLY IN THE LOWER 90S IN SOUTHEAST MINNESOTA TO AT OR
ABOVE 100 WEST OF THE JAMES RIVER. IF THERE ARE LESS CLOUDS OR THE
SURFACE HIGH RETREATS MORE QUICKLY...TEMPERATURES BOTH DAYS COULD BE
2 TO 5 DEGREES WARMER...RESULTING IN HIGHS APPROACHING 100 OVER MUCH
OF THE AREA. A WEAK BOUNDARY WILL GO THROUGH SUNDAY EVENING AND
THIS MAY BRING A BIT COOLER AIR INTO THE AREA. HOWEVER...HOW COOL
THE AIR WILL BE AND HOW LONG IT REMAINS IS VERY UNCERTAIN AT THIS
POINT. FOR NOW...FORECAST HIGHS ONLY 3 TO 5 DEGREES COOLER THAN THE
WEEKEND WHICH MEANS 90S LOOK TO PERSIST THROUGH TUESDAY. IF THE
FRONT RETREATS BACK TO THE NORTH MORE QUICKLY...PER THE 12Z
ECMWF...HIGHS COULD BE BACK OVER 100 DEGREES IN PARTS OF THE AREA BY
TUESDAY./SCHUMACHER
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
632 PM CDT MON JUL 16 2012
.DISCUSSION.../ISSUED AT 407 PM CDT/
A HOT AND HUMID DAY CURRENTLY UNDERWAY WITH TEMPERATURES WELL INTO
THE 90S AND DEWPOINTS IN THE 60S. FRONTAL BOUNDARY CURRENTLY
SITUATED AROUND HIGHWAY 14...SHOULD SLOWLY MOVE SOUTH THIS EVENING.
ATMOSPHERE REMAINS CAPPED OVER THE AREA...DESPITE MLCAPE OVER 3500
J/KG NORTH OF THE BOUNDARY. INTERESTINGLY...CU HAS FORMED FURTHER
SOUTHWEST ACROSS NEBRASKA AND NEAR THE MISSOURI RIVER. IT SEEMS
LIKELY THE ATMOSPHERE HAS MIXED ALL THE WAY THROUGH THE CAP IN THESE
AREAS. THIS IS EVIDENT BY THE LOWER DEWPOINTS IN THE 40S AND 50S IN
THESE AREAS. SO WHILE THIS MIXING HAS ERODED THE CAP...IT HAS ALSO
ERODED MUCH OF THE INSTABILITY...HENCE THE LACK OF OF SIGNIFICANT
UPGROWTH. EXPECT THIS TO CONTINUE TO BE THE CASE THROUGH THE EVENING
WITH ONLY AN ISOLATED SHOWER OR THUNDERSTORM WITH THAT CU. SEEMS
MORE PROBABLE THAT CONVECTION DEVELOPS WEST OF OUR CWA ALONG THE
OTHER BOUNDARY. THESE STORMS SHOULD PROPAGATE TOWARDS OUR WESTERN
CWA THIS EVENING...POSSIBLY IMPACTING LOCATIONS WEST OF THE JAMES
RIVER. WILL ALSO HAVE TO MONITOR DEVELOPMENT ALONG THE BACKDOOR
BOUNDARY AS IT DROPS SOUTH THROUGH THE CWA. HRRR AND NAM SEEM TO BE
OVERDOING CONVECTION CHANCES WITH THIS BOUNDARY...BUT CANT RULE OUT
A FEW STORMS WITH ABUNDANT LOW LEVEL MOISTURE POOLING AROUND THE
BOUNDARY.
UPPER LEVEL FORCING AND DEEPER MOISTURE SHOULD MOVE ACROSS THE CWA
AFTER MIDNIGHT TONIGHT. SO EVEN IF NO SURFACE CONVECTION GETS GOING
THIS EVENING...SHOULD HAVE A CHANCE OF ELEVATED STORMS LATER TONIGHT
NORTH OF THE BOUNDARY IN AREA OF LOW LEVEL THETAE ADVECTION. THIS
CONVECTION WILL LIKELY STAY GENERALLY FROM HIGHWAY 34 AND POINTS
NORTH...WITH THE ECMWF ACTUALLY KEEPING IT NORTH OF THE CWA...SO DID
NOT GO ANY HIGHER THAT 30 TO 40 POPS. LOWS TONIGHT WILL STAY
MILD...GENERALLY LOW TO MID 70S.
WEDNESDAY WILL BE ANOTHER HOT ONE ACROSS MUCH OF THE REGION...WITH
HIGHS IN THE 90S EVERYWHERE BUT SOUTHWEST MINNESOTA. DEWPOINTS WILL
LIKELY BE HIGHER THAN TODAY...ESPECIALLY ALONG AND EAST OF
INTERSTATE 29...WHERE VALUES IN THE LOW 70S ARE LIKELY. THIS WILL
MAKE FOR ANOTHER DAY OF VERY HIGH HEAT INDICES...SO WENT AHEAD AND
ISSUED A HEAT ADVISORY FOR AREAS MOST LIKELY TO HAVE A HEAT INDEX
OVER 100. THE ABOVE MENTIONED WAVE WILL CONTINUE TO PUSH EAST
WEDNESDAY. BY THIS TIME BEST CHANCE OF CONVECTION SHOULD BE
GENERALLY EAST OF INTERSTATE 29. AREAS TO THE WEST WILL BE UNDER AN
AREA OF LARGE SCALE SUBSIDENCE AND SHOULD REMAIN CAPPED. INITIAL
CONVECTION SHOULD EB ELEVATED...BUT IF THE WAVE MOVES SLOW ENOUGH WE
SHOULD SEE A TRANSITION TO SURFACE BASED CONVECTION BY AFTERNOON. IF
THIS HAPPENS...WOULD BE MOST LIKELY OVER SOUTHWEST MINNESOTA AND
PORTIONS OF NORTHWEST IOWA. COULD SEE A COUPLE SEVERE STORMS DURING
THE AFTERNOON...WITH A BIT BETTER SHEAR EXPECTED. /CHENARD
ANY CONVECTION THAT DEVELOPS ON WEDNESDAY AFTERNOON MAY LINGER INTO
THE EVENING ACROSS NW IOWA AND SW MN. MODELS DO SHOW A SECOND WEAK
WAVE MOVING SOUTHEAST ACROSS MINNESOTA ON WEDNESDAY NIGHT. THIS MAY
RESULT IN MORE STORMS DEVELOPING INTO SOUTHWEST MINNESOTA AFTER
SUNSET. AGAIN...ANY STORM DEVELOPMENT WILL BE SOMEWHAT ISOLATED. ANY
STORMS SHOULD MOVE EAST BY DAWN ON THURSDAY. OTHERWISE...EASTERLY
FLOW IS EXPECTED ACROSS THE AREA THROUGH THE EVENING. THIS WILL
BRING A BIT COOLER AIR INTO THE AREA...ALLOWING LOWS TO DROP BELOW
70 DEGREES IN SW MN ANAD BETWEEN 70 AND 75 DEGREES ELSEWHERE.
THE UPPER LEVEL RIDGE WILL BUILD ACROSS THE AREA THURSDAY AND
FRIDAY. AS HEIGHTS RISE AT 500 MB...THE SURFACE RIDGE WILL
STRENGTHEN OVER THE GREAT LAKES. THIS WILL KEEP WINDS OUT OF THE
EAST DURING THE DAY. HOWEVER...MOSTLY SUNNY SKIES ARE EXPECTED AND
THE AIR MASS REMAINS VERY WARM. TEMPERATURES ARE EXPECTED TO BE
SIMILAR TO WEDNESDAY FROM AROUND 90 IN SOUTHWEST MINNESOTA TO AROUND
100 IN SOUTH CENTRAL SD. CLEAR SKIES AND RELTIAVELY LIGHT WINDS ARE
AGAIN EXPECTED THURSDAY NIGHT. LOWS WILL BE SIMLAR TO WEDNESDAY
NIGHT FROM THE UPPER 60S IN SOUTHWEST MINNESOTA TO 70 TO 75
ELSEWHERE.
THE REMAINDER OF THE FORECAST WILL REALLY FOCUS ON THE RETURN OF THE
HEAT. OVERALL...THE GFS AND ECMWF ARE VERY SIMILAR ON THE STRENGTH
AND DURATION OF THIS RIDGE. BY EARLY NEXT WEEK THEY BOTH HAVE A
FAIRLY STRONG WAVE MOVE ALONG THE CANADIAN BORDER. THEY ALSO SHOW
THE RIDGE VERY SLOWLY BREAKING DOWN BY TUESDAY OR WEDNESDAY ALTHOUGH
OVERALL THE RIDGE REMAINS OVER THE CENTRAL UNITED STATES THROUGH THE
MIDDLE NEXT WEEK SO NO SIGNIFICANT BREAK IN THE HEAT IS REALLY
EXPECTED FOR THE NEXT 7 DAYS. IN TERMS OF PRECIPITATION...BOTH
MODELS SHOW A WEAK SYSTEM MOVING ACROSS THE DAKOTAS ON SUNDAY BUT IT
REMAINS VERY WARM ALOFT OVER SOUTHERN SOUTH DAKOTA AND THE LARGE
SCALE FORCING FOR ASCENT REMAIN CLOSER TO THE CANADIAN BORDER. SO
WHILE WE HAVE KEPT A 20 TO 30 PERCENT CHANCE OF PRECIPATION FOR
SUNDAY AND SUNDAY NIGHT...THE CONVECTION DOES NOT LOOK TO BE
WIDESPREAD AT THIS POINT AND MOST AREAS WILL LIKELY NOT SEE ANY RAIN
FROM THIS SYSTEM. GOING INTO NEXT WEEK...THERE DOES NOT APPEAR TO BE
ANY REAL CHANCE OF WIDESPREAD RAINFALL INTO THE MIDDLE OF NEXT
WEEK.
LOOKING AT DAY TO DAY...FRIDAY WILL SEE THE HEAT SPREAD INTO THE
JAMES VALLEY WITH HIGHS AROUND 100. TO THE EAST HIGHS WILL RANGE
FROM THE LOWER 90S AROUND HIGHWAY 71 IN MINNESOTA AND IOWA...TO THE
MID TO UPPER 90S IN THE REMAINDER OF SOUTHEAST SOUTH DAKOTA. AFTER
FRIDAY...LOWS SATURDAY MORNING THROUGH TUESDAY MORNING WILL BE IN
THE LOWER TO MID 70S. HIGHS ON SATURDAY AND SUNDAY WILL BE SIMILAR
TO FRIDAY GENERALLY IN THE LOWER 90S IN SOUTHEAST MINNESOTA TO AT OR
ABOVE 100 WEST OF THE JAMES RIVER. IF THERE ARE LESS CLOUDS OR THE
SURFACE HIGH RETREATS MORE QUICKLY...TEMPERATURES BOTH DAYS COULD BE
2 TO 5 DEGREES WARMER...RESULTING IN HIGHS APPROACHING 100 OVER MUCH
OF THE AREA. A WEAK BOUNDARY WILL GO THROUGH SUNDAY EVENING AND
THIS MAY BRING A BIT COOLER AIR INTO THE AREA. HOWEVER...HOW COOL
THE AIR WILL BE AND HOW LONG IT REMAINS IS VERY UNCERTAIN AT THIS
POINT. FOR NOW...FORECAST HIGHS ONLY 3 TO 5 DEGREES COOLER THAN THE
WEEKEND WHICH MEANS 90S LOOK TO PERSIST THROUGH TUESDAY. IF THE
FRONT RETREATS BACK TO THE NORTH MORE QUICKLY...PER THE 12Z
ECMWF...HIGHS COULD BE BACK OVER 100 DEGREES IN PARTS OF THE AREA BY
TUESDAY./SCHUMACHER
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH 00Z THURSDAY. FRONT
SLOWLY PROGRESSING SOUTH ACROSS THE CWA AT THIS TIME. ISOLATED
SURFACE BASED CONVECTION DEVELOPING ACROSS THE AREA...BUT CONFIDENCE
IN IT REACHING ANY OF THE PARTICULAR AIRPORTS LOW ENOUGH THAT IT WAS
LEFT OUT OF THE FORECAST. THERE IS SOME ELEVATED CONVERGENCE TONIGHT
WITH THE I-90 CORRIDOR LOCATED ON THE NOSE OF THE LOW LEVEL JET.
POTENTIAL FOR STORMS TO AFFECT I-90 AND HIGHWAY 14 CORRIDOR BUT
AGAIN CONFIDENCE IS TOO LOW TO INCLUDE IN THE FORECAST. SMALL CHANCE
A FEW OF THESE STORMS FORM FURTHER SOUTH WEDNESDAY MORNING AND EARLY
AFTERNOON CLOSER TO KFSD AND KSUX...BUT PROBABILITY AND TIMING
CONFIDENCE TOO LOW TO INCLUDE IN TAF. MODEL SOUNDINGS ARE QUICK TO
GO CONVECTIVE...BUT APPEAR TO BE TOO QUICK TO BREAK DOWN THE
ELEVATED INVERSION ALOFT. IF CONVECTION WAS ABLE TO DEVELOP BEST
CHANCES WOULD BE IN THE 17-21Z TIMEFRAME FOR INITIATION.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1254 PM CDT MON JUL 16 2012
.UPDATE...FOR AVIATION.
&&
.AVIATION...18Z TAFS.
SCT TRW PLAT W/TSTM TEMPO 19-22Z KCSV. ISO CELLS IN DAVISION CO
W/VCTS KBNA...SCT040CB KCSV. ANOTHER QUIET NGT TNGT W/IFR FOG
POSSIBLE LATE AT KCKV AND KCSV.
&&
.PREV DISCUSSION... /ISSUED 913 AM CDT MON JUL 16 2012/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT
REGIONAL RADAR AND SATELLITE IMAGERY WITH THE BEST CHANCE OF SCT
SHWRS/TSTMS DURING THE AFTERNOON HRS. LATEST HIGH RESOLUTION RAPID
REFRESH SHORT TERM MODEL SHOWING SCT SHWRS/TSTMS DEVELOPING RAPIDLY
AFTER CONVECTIVE TEMP HAS BEEN REACHED. ON THE 12Z MON KOHX
SOUNDING IT IS LISTED AT 88 DEGREES...WHICH SHOULD GENERALLY BE
REACHED BY THE MAJORITY OF THE LOCATIONS BY THE NOON TIME HR.
CURRENT TEMPS IN LINE WITH FORECASTED HIGH VALUES AND THUS MADE NO
CHANGES IN THESE AT THIS TIME.
PREV DISCUSSION.../ISSUED 606 AM CDT MON JUL 16 2012/
AVIATION...FOR 12Z TAF PACKAGE...
FG AT KCKV SHALL BEGIN TO LET UP IN THE NEXT FEW HOURS.
THUNDERSTORM DEVELOPMENT WILL OCCUR LIKELY BY 17Z. HEAVY RAIN MAY
REDUCE VISIBILITIES AT TERMINALS IF IMPACTED BY STORMS. BY 00Z VFR
CONDITIONS SHOULD RETURN FOR ALL THREE TERMINALS. BR WILL BE
POSSIBLE AT KCSV AFTER 06Z.
PREV DISCUSSION... /ISSUED 411 AM CDT MON JUL 16 2012/
DISCUSSION...
IR SATELLITE THIS MORNING IS INDICATING STRONG SUBSIDENCE ALONG THE
MS RIVER VALLEY AND ALTHOUGH RUC/NAM/HRRR INSIST ON BREAKING OUT
SHOWERS ALONG A SWATH OF DECENT DEEP MOISTURE ADVECTION BASICALLY
CIRCLING THE ANTICYCLONE CENTER...IT APPEARS THAT THE SUBSIDENCE IS
OVERTAKING ANY LIFT BEING GENERATED BY WEAK LOW LEVEL FLOW. THIS
LIKELY MEANS THAT CONVECTION WILL HAVE TO WAIT TILL DIURNAL HEATING
BEGINS. WITH THIS SUBSIDENCE UNDER THE HIGH PRESSURE CENTER WHICH IS
DRAPED OVER MOST OF THE TN VALLEY...THINK THAT IT WILL TAKE A BIT
LONGER FOR CONVECTION TO OCCUR...PERHAPS AROUND 18Z TODAY AS TEMPS
RISE. ALTHOUGH...NOT MUCH CLOUD COVER TO SPEAK OF SO TEMPS MAY RISE
QUICKLY TODAY...RISING INTO THE 90S BY 17Z. LATEST HRRR BREAKS OUT
SCATTERED THUNDER AROUND THIS TIME. LOTS OF SBCAPE AND PRETTY GOOD
LAPSE RATES ON THE FORECAST SOUNDINGS BY 18Z SO LOCALLY HEAVY RAIN
AND GUSTY WINDS WILL ONCE AGAIN BE A CONCERN.
IN THE EXTENDED...THE ANTICYCLONE THAT HAS BEEN FEEDING THE
SOUTHEAST CONUS WITH SUCH RICH MOISTURE WILL SLOWLY TRANSLATE
WESTWARD AND MIX WITH THE DRIER RIDGE OVER THE MIDWEST. THIS WILL
TRANSITION OUR H5 FLOW TO NORTHWEST BY MID WEEK. GFS NEVER LETS UP
THE DEEP MOISTURE HOWEVER NAM SEEMS TO PROGRESSIVELY DRY OUT THE
COLUMN WHICH MAKES MORE SENSE FOR THIS CONTINUED HIGH PRESSURE AND
WEAKER GULF MOISTURE ADVECTION. SINCE GFS IS SO AGGRESSIVE WITH
POPS...DECIDED TO SIDE WITH THE DRIER NAM/ECMWF. THIS MEANS HIGHS IN
THE MID 90S BY MID WEEK AND HEAT INDEXES IN THE TRIPLE DIGITS. AT
THE MOMENT IT LOOKS LIKE WE WILL BE 3-4 DEGREES BELOW ADVISORY
CRITERIA FOR NASHVILLE AND EAST. HOWEVER WESTERN COUNTIES WILL
COME CLOSE. WILL LET DAY SHIFT MAKE DECISION ON ANY ADVISORIES.
BY THE END OF THE WEEK...A POSSIBILITY OF A BACKDOOR COLD FRONT
BEING EJECTED FROM A SOUTHEASTERN MOVING H5 LOW FROM THE CANADIAN
SIDE OF THE GREAT LAKES IS THE BIGGEST QUESTION MARK. ECMWF AND GFS
HAVE BOTH SLOWED TO DELAY THIS PASSAGE UNTIL SATURDAY AFTERNOON
HOWEVER THE GFS PLOWS RIGHT THROUGH THE MID STATE WHILE ECMWF STALLS
THE FRONT JUST NORTH OF THE CWA. SINCE THIS UNCERTAINTY EXISTS IN
THE MODELS ATTM...WILL STICK WITH THE FAVORING OF THE ECMWF AND
LEAVE THE EXTENDED RELATIVELY UNCHANGED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
913 AM CDT MON JUL 16 2012
.UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT
REGIONAL RADAR AND SATELLITE IMAGERY WITH THE BEST CHANCE OF SCT
SHWRS/TSTMS DURING THE AFTERNOON HRS. LATEST HIGH RESOLUTION RAPID
REFRESH SHORT TERM MODEL SHOWING SCT SHWRS/TSTMS DEVELOPING RAPIDLY
AFTER CONVECTIVE TEMP HAS BEEN REACHED. ON THE 12Z MON KOHX
SOUNDING IT IS LISTED AT 88 DEGREES...WHICH SHOULD GENERALLY BE
REACHED BY THE MAJORITY OF THE LOCATIONS BY THE NOON TIME HR.
CURRENT TEMPS IN LINE WITH FORECASTED HIGH VALUES AND THUS MADE NO
CHANGES IN THESE AT THIS TIME.
&&
.PREV DISCUSSION.../ISSUED 606 AM CDT MON JUL 16 2012/
AVIATION...FOR 12Z TAF PACKAGE...
FG AT KCKV SHALL BEGIN TO LET UP IN THE NEXT FEW HOURS.
THUNDERSTORM DEVELOPMENT WILL OCCUR LIKELY BY 17Z. HEAVY RAIN MAY
REDUCE VISIBILITIES AT TERMINALS IF IMPACTED BY STORMS. BY 00Z VFR
CONDITIONS SHOULD RETURN FOR ALL THREE TERMINALS. BR WILL BE
POSSIBLE AT KCSV AFTER 06Z.
PREV DISCUSSION... /ISSUED 411 AM CDT MON JUL 16 2012/
DISCUSSION...
IR SATELLITE THIS MORNING IS INDICATING STRONG SUBSIDENCE ALONG THE
MS RIVER VALLEY AND ALTHOUGH RUC/NAM/HRRR INSIST ON BREAKING OUT
SHOWERS ALONG A SWATH OF DECENT DEEP MOISTURE ADVECTION BASICALLY
CIRCLING THE ANTICYCLONE CENTER...IT APPEARS THAT THE SUBSIDENCE IS
OVERTAKING ANY LIFT BEING GENERATED BY WEAK LOW LEVEL FLOW. THIS
LIKELY MEANS THAT CONVECTION WILL HAVE TO WAIT TILL DIURNAL HEATING
BEGINS. WITH THIS SUBSIDENCE UNDER THE HIGH PRESSURE CENTER WHICH IS
DRAPED OVER MOST OF THE TN VALLEY...THINK THAT IT WILL TAKE A BIT
LONGER FOR CONVECTION TO OCCUR...PERHAPS AROUND 18Z TODAY AS TEMPS
RISE. ALTHOUGH...NOT MUCH CLOUD COVER TO SPEAK OF SO TEMPS MAY RISE
QUICKLY TODAY...RISING INTO THE 90S BY 17Z. LATEST HRRR BREAKS OUT
SCATTERED THUNDER AROUND THIS TIME. LOTS OF SBCAPE AND PRETTY GOOD
LAPSE RATES ON THE FORECAST SOUNDINGS BY 18Z SO LOCALLY HEAVY RAIN
AND GUSTY WINDS WILL ONCE AGAIN BE A CONCERN.
IN THE EXTENDED...THE ANTICYCLONE THAT HAS BEEN FEEDING THE
SOUTHEAST CONUS WITH SUCH RICH MOISTURE WILL SLOWLY TRANSLATE
WESTWARD AND MIX WITH THE DRIER RIDGE OVER THE MIDWEST. THIS WILL
TRANSITION OUR H5 FLOW TO NORTHWEST BY MID WEEK. GFS NEVER LETS UP
THE DEEP MOISTURE HOWEVER NAM SEEMS TO PROGRESSIVELY DRY OUT THE
COLUMN WHICH MAKES MORE SENSE FOR THIS CONTINUED HIGH PRESSURE AND
WEAKER GULF MOISTURE ADVECTION. SINCE GFS IS SO AGGRESSIVE WITH
POPS...DECIDED TO SIDE WITH THE DRIER NAM/ECMWF. THIS MEANS HIGHS IN
THE MID 90S BY MID WEEK AND HEAT INDEXES IN THE TRIPLE DIGITS. AT
THE MOMENT IT LOOKS LIKE WE WILL BE 3-4 DEGREES BELOW ADVISORY
CRITERIA FOR NASHVILLE AND EAST. HOWEVER WESTERN COUNTIES WILL
COME CLOSE. WILL LET DAY SHIFT MAKE DECISION ON ANY ADVISORIES.
BY THE END OF THE WEEK...A POSSIBILITY OF A BACKDOOR COLD FRONT
BEING EJECTED FROM A SOUTHEASTERN MOVING H5 LOW FROM THE CANADIAN
SIDE OF THE GREAT LAKES IS THE BIGGEST QUESTION MARK. ECMWF AND GFS
HAVE BOTH SLOWED TO DELAY THIS PASSAGE UNTIL SATURDAY AFTERNOON
HOWEVER THE GFS PLOWS RIGHT THROUGH THE MID STATE WHILE ECMWF STALLS
THE FRONT JUST NORTH OF THE CWA. SINCE THIS UNCERTAINTY EXISTS IN
THE MODELS ATTM...WILL STICK WITH THE FAVORING OF THE ECMWF AND
LEAVE THE EXTENDED RELATIVELY UNCHANGED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
606 AM CDT MON JUL 16 2012
.AVIATION...FOR 12Z TAF PACKAGE...
FG AT KCKV SHALL BEGIN TO LET UP IN THE NEXT FEW HOURS.
THUNDERSTORM DEVELOPMENT WILL OCCUR LIKELY BY 17Z. HEAVY RAIN MAY
REDUCE VISIBILITIES AT TERMINALS IF IMPACTED BY STORMS. BY 00Z VFR
CONDITIONS SHOULD RETURN FOR ALL THREE TERMINALS. BR WILL BE
POSSIBLE AT KCSV AFTER 06Z.
&&
.PREV DISCUSSION... /ISSUED 411 AM CDT MON JUL 16 2012/
DISCUSSION...
IR SATELLITE THIS MORNING IS INDICATING STRONG SUBSIDENCE ALONG THE
MS RIVER VALLEY AND ALTHOUGH RUC/NAM/HRRR INSIST ON BREAKING OUT
SHOWERS ALONG A SWATH OF DECENT DEEP MOISTURE ADVECTION BASICALLY
CIRCLING THE ANTICYCLONE CENTER...IT APPEARS THAT THE SUBSIDENCE IS
OVERTAKING ANY LIFT BEING GENERATED BY WEAK LOW LEVEL FLOW. THIS
LIKELY MEANS THAT CONVECTION WILL HAVE TO WAIT TILL DIURNAL HEATING
BEGINS. WITH THIS SUBSIDENCE UNDER THE HIGH PRESSURE CENTER WHICH IS
DRAPED OVER MOST OF THE TN VALLEY...THINK THAT IT WILL TAKE A BIT
LONGER FOR CONVECTION TO OCCUR...PERHAPS AROUND 18Z TODAY AS TEMPS
RISE. ALTHOUGH...NOT MUCH CLOUD COVER TO SPEAK OF SO TEMPS MAY RISE
QUICKLY TODAY...RISING INTO THE 90S BY 17Z. LATEST HRRR BREAKS OUT
SCATTERED THUNDER AROUND THIS TIME. LOTS OF SBCAPE AND PRETTY GOOD
LAPSE RATES ON THE FORECAST SOUNDINGS BY 18Z SO LOCALLY HEAVY RAIN
AND GUSTY WINDS WILL ONCE AGAIN BE A CONCERN.
IN THE EXTENDED...THE ANTICYCLONE THAT HAS BEEN FEEDING THE
SOUTHEAST CONUS WITH SUCH RICH MOISTURE WILL SLOWLY TRANSLATE
WESTWARD AND MIX WITH THE DRIER RIDGE OVER THE MIDWEST. THIS WILL
TRANSITION OUR H5 FLOW TO NORTHWEST BY MID WEEK. GFS NEVER LETS UP
THE DEEP MOISTURE HOWEVER NAM SEEMS TO PROGRESSIVELY DRY OUT THE
COLUMN WHICH MAKES MORE SENSE FOR THIS CONTINUED HIGH PRESSURE AND
WEAKER GULF MOISTURE ADVECTION. SINCE GFS IS SO AGGRESSIVE WITH
POPS...DECIDED TO SIDE WITH THE DRIER NAM/ECMWF. THIS MEANS HIGHS IN
THE MID 90S BY MID WEEK AND HEAT INDEXES IN THE TRIPLE DIGITS. AT
THE MOMENT IT LOOKS LIKE WE WILL BE 3-4 DEGREES BELOW ADVISORY
CRITERIA FOR NASHVILLE AND EAST. HOWEVER WESTERN COUNTIES WILL
COME CLOSE. WILL LET DAY SHIFT MAKE DECISION ON ANY ADVISORIES.
BY THE END OF THE WEEK...A POSSIBILITY OF A BACKDOOR COLD FRONT
BEING EJECTED FROM A SOUTHEASTERN MOVING H5 LOW FROM THE CANADIAN
SIDE OF THE GREAT LAKES IS THE BIGGEST QUESTION MARK. ECMWF AND GFS
HAVE BOTH SLOWED TO DELAY THIS PASSAGE UNTIL SATURDAY AFTERNOON
HOWEVER THE GFS PLOWS RIGHT THROUGH THE MID STATE WHILE ECMWF STALLS
THE FRONT JUST NORTH OF THE CWA. SINCE THIS UNCERTAINTY EXISTS IN
THE MODELS ATTM...WILL STICK WITH THE FAVORING OF THE ECMWF AND
LEAVE THE EXTENDED RELATIVELY UNCHANGED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
411 AM CDT MON JUL 16 2012
.DISCUSSION...
IR SATELLITE THIS MORNING IS INDICATING STRONG SUBSIDENCE ALONG THE
MS RIVER VALLEY AND ALTHOUGH RUC/NAM/HRRR INSIST ON BREAKING OUT
SHOWERS ALONG A SWATH OF DECENT DEEP MOISTURE ADVECTION BASICALLY
CIRCLING THE ANTICYCLONE CENTER...IT APPEARS THAT THE SUBSIDENCE IS
OVERTAKING ANY LIFT BEING GENERATED BY WEAK LOW LEVEL FLOW. THIS
LIKELY MEANS THAT CONVECTION WILL HAVE TO WAIT TILL DIURNAL HEATING
BEGINS. WITH THIS SUBSIDENCE UNDER THE HIGH PRESSURE CENTER WHICH IS
DRAPED OVER MOST OF THE TN VALLEY...THINK THAT IT WILL TAKE A BIT
LONGER FOR CONVECTION TO OCCUR...PERHAPS AROUND 18Z TODAY AS TEMPS
RISE. ALTHOUGH...NOT MUCH CLOUD COVER TO SPEAK OF SO TEMPS MAY RISE
QUICKLY TODAY...RISING INTO THE 90S BY 17Z. LATEST HRRR BREAKS OUT
SCATTERED THUNDER AROUND THIS TIME. LOTS OF SBCAPE AND PRETTY GOOD
LAPSE RATES ON THE FORECAST SOUNDINGS BY 18Z SO LOCALLY HEAVY RAIN
AND GUSTY WINDS WILL ONCE AGAIN BE A CONCERN.
IN THE EXTENDED...THE ANTICYCLONE THAT HAS BEEN FEEDING THE
SOUTHEAST CONUS WITH SUCH RICH MOISTURE WILL SLOWLY TRANSLATE
WESTWARD AND MIX WITH THE DRIER RIDGE OVER THE MIDWEST. THIS WILL
TRANSITION OUR H5 FLOW TO NORTHWEST BY MID WEEK. GFS NEVER LETS UP
THE DEEP MOISTURE HOWEVER NAM SEEMS TO PROGRESSIVELY DRY OUT THE
COLUMN WHICH MAKES MORE SENSE FOR THIS CONTINUED HIGH PRESSURE AND
WEAKER GULF MOISTURE ADVECTION. SINCE GFS IS SO AGGRESSIVE WITH
POPS...DECIDED TO SIDE WITH THE DRIER NAM/ECMWF. THIS MEANS HIGHS IN
THE MID 90S BY MID WEEK AND HEAT INDEXES IN THE TRIPLE DIGITS. AT
THE MOMENT IT LOOKS LIKE WE WILL BE 3-4 DEGREES BELOW ADVISORY
CRITERIA FOR NASHVILLE AND EAST. HOWEVER WESTERN COUNTIES WILL
COME CLOSE. WILL LET DAY SHIFT MAKE DECISION ON ANY ADVISORIES.
BY THE END OF THE WEEK...A POSSIBILITY OF A BACKDOOR COLD FRONT
BEING EJECTED FROM A SOUTHEASTERN MOVING H5 LOW FROM THE CANADIAN
SIDE OF THE GREAT LAKES IS THE BIGGEST QUESTION MARK. ECMWF AND GFS
HAVE BOTH SLOWED TO DELAY THIS PASSAGE UNTIL SATURDAY AFTERNOON
HOWEVER THE GFS PLOWS RIGHT THROUGH THE MID STATE WHILE ECMWF STALLS
THE FRONT JUST NORTH OF THE CWA. SINCE THIS UNCERTAINTY EXISTS IN
THE MODELS ATTM...WILL STICK WITH THE FAVORING OF THE ECMWF AND
LEAVE THE EXTENDED RELATIVELY UNCHANGED.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 94 71 94 73 / 30 05 30 10
CLARKSVILLE 94 71 94 73 / 30 05 30 10
CROSSVILLE 89 67 89 69 / 30 20 30 10
COLUMBIA 94 71 95 72 / 20 05 30 10
LAWRENCEBURG 94 71 95 72 / 20 05 30 10
WAVERLY 94 71 95 73 / 30 05 30 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1220 AM CDT MON JUL 16 2012
.UPDATE... /ISSUED 907 PM CDT SUN JUL 15 2012/
SKIES ARE CLEAR TO PARTLY CLOUDY THIS EVENING WITH TEMPERATURES
RANGING FROM THE LOWER 70S TO LOWER 80S. WHAT LITTLE SHOWER
ACTIVITY THAT REMAINS OVER THE FORECAST AREA IS FALLING APART AND
THERE SHOULD BE NO MORE PRECIPITATION BY 10 PM. WILL UPDATE
FORECAST TO REMOVE EVENING WORDING OTHERWISE FORECAST IS ON TRACK
AND NO OTHER CHANGES ARE NEEDED.
ARS
&&
.DISCUSSION... /ISSUED 333 PM CDT SUN JUL 15 2012/
CURRENTLY...UPPER LEVEL RIDING IS PUSHING BACK INTO THE REGION
FROM THE EAST WHICH HAS PUSHED THE MOISTURE AXIS THAT CONTAINS
PWAT VALUES GREATER THAN 2 INCHES TO THE WESTERN HALF OF THE
MIDSOUTH. AN OUTFLOW BOUNDARY PUSHING NORTH INTO NW MS IS
PRODUCING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH
ISOLATED TO SCATTERED CONVECTION ACROSS EASTERN ARKANSAS AND THE
MO BOOTHEEL. DRIER AIR WORKING INTO THE EASTERN HALF HAS SEVERELY
LIMITED AREAL COVERAGE EAST OF MEMPHIS FOR NOW. TEMPS ARE
GENERALLY IN THE MID AND UPPER 80S THOUGH A FEW READINGS ABOVE 90
CAN BE FOUND ACROSS NE MS AND SE PARTS OF WEST TN.
TONIGHT...BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO BE ACROSS THE WESTERN HALF OF THE MIDSOUTH THROUGH EARLY
EVENING WITH LESS COVERAGE TO THE EAST. SOME OF STORMS WILL
CONTAIN VERY HEAVY RAINFALL AND GUSTY WINDS. CONVECTION IS MAINLY
SURFACE HEATING BASED SO ACTIVITY WILL DISSIPATE QUICKLY THIS
EVENING AND THIS IS CONFIRMED NICELY BY THE LATEST HRRR RUN.
TEMPS WILL BE SIMILAR TO THE PAST SEVERAL NIGHT WITH LOWS IN THE
70 TO 75 DEGREE RANGE.
MONDAY THROUGH WEDNESDAY...UPPER RIDGE WILL BE OVER THE AREA AND
TEMPS WILL START TO HEAT UP INTO THE MID 90S BY TUESDAY AND
WEDNESDAY. SURFACE DEWPOINTS SHOULD REMAIN IN AT LEAST THE LOWER
70S WHICH MAY PRODUCE HEAT INDEX VALUES NEAR ADVISORY LEVELS BY
MIDWEEK. EVEN WITH THE UPPER RIDGE OVER THE AREA THE MID LEVEL
CAPPING WILL NOT BE STRONG ENOUGH TO COMPLETELY SHUT OFF
CONVECTION...THOUGH AREAL COVERAGE WILL BE LOWER AS PWAT VALUES
FALL. OVERNIGHT LOWS WILL BE TRENDING UP AS WELL.
THURSDAY THROUGH SUNDAY...UPPER RIDGE MAY WEAKEN SLIGHTLY AS AN
UPPER TROF MOVING THROUGH THE NORTHEAST/EASTERN GREAT LAKES SENDS
A BACK DOOR COLD FRONT INTO THE OHIO VALLEY. 12Z MODELS ARE NOT IN
VERY GOOD AGREEMENT ATTM. THE 12Z GFS LEANS TOWARD MORE UPPER
LEVEL RIDGING. MEANWHILE THE ECMWF DEVELOPS A CLOSED 500 MB LOW
OVER THE EASTERN OHIO VALLEY BY SUNDAY AFTERNOON. HAVE GENERALLY
GONE WITH A COMPROMISE BETWEEN THE COOLER/WETTER ECMWF AND THE
WARMER/DRIER GFS.
SJM
&&
.AVIATION...
06Z TAF CYCLE
THINK FOG FORMATION MAY BE A PROBLEM FOR AVIATION AS THE NIGHT WEARS
ON WITH CLOUD COVER HAVING DIMINISHED...LIGHT WINDS AND A WET
GROUND IN MOST LOCATIONS FROM RECENT RAINS. HAVE ALREADY UPDATED THE
TAFS EARLIER SUNDAY EVENING TO BEEF UP MENTION OF FOG WITH THE
POSSIBILITY OF IFR CONDITIONS BY LATE TONIGHT. FOG GRADUALLY
DISSIPATING AFTER SUNRISE BUT LOW CLOUDS ARE EXPECTED TO KEEP
CONDITIONS MVFR UNTIL ABOUT 16/17Z...THEN CONDITIONS IMPROVING TO
VFR.
UPPER LEVEL RIDGE WILL STRENGTHEN OVER THE MIDSOUTH MONDAY HELPING
TO SUPPRESS CONVECTION ALTHOUGH CAN NOT RULE OUT A FEW TSRA WITH
DAYTIME HEATING. HOWEVER...THINK THE PROBABILITY IS TOO LOW TO
MENTION TSRA IN ANY OF THE TAFS FOR MONDAY ATTM.
LIGHT WINDS TONIGHT. WINDS MONDAY BECOMING S-SW 6-10 KTS DIMINISHING
TO 5 KTS OR LESS AFTER 17/01Z.
JCL/KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 76 95 77 96 / 10 20 10 20
MKL 72 94 72 95 / 10 20 10 30
JBR 74 95 75 96 / 10 20 10 20
TUP 74 94 74 94 / 10 30 10 40
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
826 PM CDT TUE JUL 17 2012
.UPDATE...
DRY...SINKING AIR ALOFT ROTATING AROUND THE UPPER LOW TO OUR
SOUTH AND ATOP THE SOUTH PLAINS HAS PROVEN TOO MUCH TO SUPPORT
CONVECTIVE INITIATION LOCALLY THIS AFTERNOON OR EARLY THIS
EVENING. HENCE...HAVE REMOVED THE LOW THUNDER MENTION FOR MOST OF
THE CENTRAL AND EASTERN ZONES FOR THE REMAINDER OF THE NIGHT.
HOWEVER...A SMALL CLUSTER OF STORMS HAS ORGANIZED FROM NORTHEAST
NEW MEXICO INTO THE WEST-CENTRAL TEXAS PANHANDLE AND THIS ACTIVITY
WAS SAGGING SLOWLY SOUTHWARD AND COULD POTENTIALLY AFFECT THE
NORTHWEST LATER TONIGHT...IF IT CAN HOLD TOGETHER. THUS...HAVE
MAINTAINED A SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE NORTHWEST
ZONES. OTHERWISE...HAVE MADE A FEW OTHER MINOR ADJUSTMENTS TO THE
SHORT TERM GRIDS TO BETTER REFLECT THE MOST RECENT OBSERVATIONS
AND EXPECTED TRENDS. UPDATED PRODUCTS HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 637 PM CDT TUE JUL 17 2012/
AVIATION...
VFR ENTIRE CYCLE AT BOTH KLBB AND KCDS. CHANCE OF A ROGUE TS
TOO LOW TO MENTION ATTM.
PREV DISCUSSION... /ISSUED 336 PM CDT TUE JUL 17 2012/
SHORT TERM...
PRECIPITATION THIS MORNING WAS NOT AS EXTENSIVE AS YESTERDAY AND WAS
ALSO LIMITED TO NEAR THE TX/NM STATE LINE. 12Z MODELS WERE NOT
GENERATING MUCH PRECIPITATION AS WELL WITH THE NAM BEING THE ONLY
MODEL WITH POPS OVER PORTIONS OF THE FORECAST AREA. HRRR RUNS THROUGH
14Z WERE ALSO NOT BREAKING OUT PRECIPITATION OVER THE REGION BUT THE
LATEST RUNS SINCE 15Z ARE SHOWING SOME CONVECTION OVER THE ROLLING
PLAINS WHILE LEAVING THE SOUTH PLAINS HIGH AND DRY. HARD TO TELL
HOW THINGS WILL PLAY OUT AS WV SATELLITE LOOP SHOWS DRIER AIR
PUSHING INTO THE REGION ALOFT AND MODELS INDICATE CAP HAS
STRENGTHENED JUST A BIT AS WELL. WILL KEEP BEST CHANCES FOR PRECIP
TONIGHT NEAR THE STATE LINE WHICH IS CLOSER TO THE MID-LEVEL
MOISTURE AXIS AND BETTER LAPSE RATES. ONE OTHER ISSUE IS THE
UPPER-LEVEL LOW WHICH IS STARTING TO SLOWLY DRIFT TO THE NORTHWEST
OVER THE LAST COUPLE OF HOURS. DEPENDING ON HOW CLOSE THIS GETS TO
THE REGION...THIS MAY HELP INITIATE A FEW STORMS LATER THIS
EVENING. AS A RESULT...WILL KEEP MENTION OF ISOLATED POPS OVER THE
ROLLING PLAINS AND THE EASTERN/CENTRAL SOUTH PLAINS THROUGH THE
NIGHT. WITH THE UPPER LOW MOVING WEST AND THE RIDGE PUSHING BACK
OVER THE AREA...POP CHANCES DECREASE TOMORROW EVEN MORE WITH
TEMPERATURES A FEW DEGREES WARMER THAN TODAY.
JORDAN
LONG TERM...
UA RIDGE WILL COMMENCE TO BUILD ACROSS THE CENTRAL PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING...WHERE THE MONSOONAL MOISTURE PLUME WILL BE
CAPABLE OF BENDING EASTWARD TOWARDS THE SOUTHWESTERN TEXAS PANHANDLE
AND FAR WESTERN SOUTH PLAINS. LATEST MODEL RUNS HAVE BACKED OFF ON
SHOWING PRECIP DEVELOPING ACROSS THE AFOREMENTIONED AREAS...AS IT
GETS SHUNTED WESTWARD QUICKER THAN PREVIOUS RUNS. MID-LEVEL
INSTABILITY DROP TO 50-100 J/KG AND PWATS ALSO DECLINE TO AOA 1.00
INCH. WILL GO AHEAD AND MAINTAIN POPS TO JUST WEST OF THE TEXAS
STATE LINE. THEREAFTER...THE UA RIDGE ACROSS THE CENTRAL PLAINS WILL
BE THE DOMINATE SYNOPTIC FEATURE FOR THE SOUTHERN PLAINS...AS SLOWLY
INCREASING HEIGHT FIELDS WILL PROMOTE TEMPS TO WARM ABOVE SEASONAL
NORMS BY THE WEEKEND /MID 90S ON THE CAPROCK TO TRIPLE DIGITS OFF
THE CAPROCK/....AND LARGE SCALE SUBSIDENCE WILL MITIGATE STORM
POTENTIAL. THEREAFTER...BOTH THE GFS AND ECMWF HINT AT THE CENTER OF
THE UA RIDGE TRANSLATING EAST TOWARDS THE CENTRAL MISSISSIPPI VALLEY
EARLY NEXT WEEK. AN EASTERLY WAVE IS EXHIBITED BRUSHING ACROSS THE
SOUTHERN LOCALES ON TUESDAY. THE SAID MODELS ARE VOID OF
PRECIP...GIVEN THIS WEAKNESS IS DISPLAYED TO BE RELATIVELY WEAK.
WILL NEED TO KEEP AN EYE ON HOW THE SYNOPTIC PATTERN EVOLVES AND
WHETHER OR NOT THIS EASTERLY WAVE WILL INDEED PROVE TO BE
INCONSEQUENTIAL FOR THE SOUTHERN PLAINS...OR TURN OUT TO BE A
SYNOPTIC SPARK FOR CI.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 62 93 64 92 65 / 20 10 10 10 10
TULIA 64 94 66 93 67 / 20 10 10 10 10
PLAINVIEW 67 94 67 92 68 / 10 10 10 0 0
LEVELLAND 65 94 67 93 67 / 10 10 10 0 0
LUBBOCK 69 95 68 94 69 / 10 10 10 0 0
DENVER CITY 64 93 67 92 66 / 10 10 10 10 10
BROWNFIELD 65 93 67 92 67 / 10 10 10 0 0
CHILDRESS 70 99 72 99 73 / 10 10 10 0 0
SPUR 66 96 69 95 70 / 10 10 10 0 0
ASPERMONT 71 99 72 98 72 / 10 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/23
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
637 PM CDT TUE JUL 17 2012
.AVIATION...
VFR ENTIRE CYCLE AT BOTH KLBB AND KCDS. CHANCE OF A ROGUE TS
TOO LOW TO MENTION ATTM.
&&
.PREV DISCUSSION... /ISSUED 336 PM CDT TUE JUL 17 2012/
SHORT TERM...
PRECIPITATION THIS MORNING WAS NOT AS EXTENSIVE AS YESTERDAY AND WAS
ALSO LIMITED TO NEAR THE TX/NM STATE LINE. 12Z MODELS WERE NOT
GENERATING MUCH PRECIPITATION AS WELL WITH THE NAM BEING THE ONLY
MODEL WITH POPS OVER PORTIONS OF THE FORECAST AREA. HRRR RUNS THROUGH
14Z WERE ALSO NOT BREAKING OUT PRECIPITATION OVER THE REGION BUT THE
LATEST RUNS SINCE 15Z ARE SHOWING SOME CONVECTION OVER THE ROLLING
PLAINS WHILE LEAVING THE SOUTH PLAINS HIGH AND DRY. HARD TO TELL
HOW THINGS WILL PLAY OUT AS WV SATELLITE LOOP SHOWS DRIER AIR
PUSHING INTO THE REGION ALOFT AND MODELS INDICATE CAP HAS
STRENGTHENED JUST A BIT AS WELL. WILL KEEP BEST CHANCES FOR PRECIP
TONIGHT NEAR THE STATE LINE WHICH IS CLOSER TO THE MID-LEVEL
MOISTURE AXIS AND BETTER LAPSE RATES. ONE OTHER ISSUE IS THE
UPPER-LEVEL LOW WHICH IS STARTING TO SLOWLY DRIFT TO THE NORTHWEST
OVER THE LAST COUPLE OF HOURS. DEPENDING ON HOW CLOSE THIS GETS TO
THE REGION...THIS MAY HELP INITIATE A FEW STORMS LATER THIS
EVENING. AS A RESULT...WILL KEEP MENTION OF ISOLATED POPS OVER THE
ROLLING PLAINS AND THE EASTERN/CENTRAL SOUTH PLAINS THROUGH THE
NIGHT. WITH THE UPPER LOW MOVING WEST AND THE RIDGE PUSHING BACK
OVER THE AREA...POP CHANCES DECREASE TOMORROW EVEN MORE WITH
TEMPERATURES A FEW DEGREES WARMER THAN TODAY.
JORDAN
LONG TERM...
UA RIDGE WILL COMMENCE TO BUILD ACROSS THE CENTRAL PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING...WHERE THE MONSOONAL MOISTURE PLUME WILL BE
CAPABLE OF BENDING EASTWARD TOWARDS THE SOUTHWESTERN TEXAS PANHANDLE
AND FAR WESTERN SOUTH PLAINS. LATEST MODEL RUNS HAVE BACKED OFF ON
SHOWING PRECIP DEVELOPING ACROSS THE AFOREMENTIONED AREAS...AS IT
GETS SHUNTED WESTWARD QUICKER THAN PREVIOUS RUNS. MID-LEVEL
INSTABILITY DROP TO 50-100 J/KG AND PWATS ALSO DECLINE TO AOA 1.00
INCH. WILL GO AHEAD AND MAINTAIN POPS TO JUST WEST OF THE TEXAS
STATE LINE. THEREAFTER...THE UA RIDGE ACROSS THE CENTRAL PLAINS WILL
BE THE DOMINATE SYNOPTIC FEATURE FOR THE SOUTHERN PLAINS...AS SLOWLY
INCREASING HEIGHT FIELDS WILL PROMOTE TEMPS TO WARM ABOVE SEASONAL
NORMS BY THE WEEKEND /MID 90S ON THE CAPROCK TO TRIPLE DIGITS OFF
THE CAPROCK/....AND LARGE SCALE SUBSIDENCE WILL MITIGATE STORM
POTENTIAL. THEREAFTER...BOTH THE GFS AND ECMWF HINT AT THE CENTER OF
THE UA RIDGE TRANSLATING EAST TOWARDS THE CENTRAL MISSISSIPPI VALLEY
EARLY NEXT WEEK. AN EASTERLY WAVE IS EXHIBITED BRUSHING ACROSS THE
SOUTHERN LOCALES ON TUESDAY. THE SAID MODELS ARE VOID OF
PRECIP...GIVEN THIS WEAKNESS IS DISPLAYED TO BE RELATIVELY WEAK.
WILL NEED TO KEEP AN EYE ON HOW THE SYNOPTIC PATTERN EVOLVES AND
WHETHER OR NOT THIS EASTERLY WAVE WILL INDEED PROVE TO BE
INCONSEQUENTIAL FOR THE SOUTHERN PLAINS...OR TURN OUT TO BE A
SYNOPTIC SPARK FOR CI.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 62 93 64 92 65 / 20 10 10 10 10
TULIA 64 94 66 93 67 / 20 10 10 10 10
PLAINVIEW 67 94 67 92 68 / 10 10 10 0 0
LEVELLAND 65 94 67 93 67 / 20 10 10 0 0
LUBBOCK 69 95 68 94 69 / 10 10 10 0 0
DENVER CITY 64 93 67 92 66 / 20 10 10 10 10
BROWNFIELD 65 93 67 92 67 / 20 10 10 0 0
CHILDRESS 70 99 72 99 73 / 10 10 10 0 0
SPUR 66 96 69 95 70 / 10 10 10 0 0
ASPERMONT 71 99 72 98 72 / 10 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/26
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
227 PM CDT MON JUL 16 2012
.DISCUSSION...
ACCAS OUTSIDE IS DEVELOPING INTO ELEVATED SHOWERS AND
THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON. THE LATEST RUC IS
DOING A GOOD JOB DEPICTING THIS PRECIP...BUT IS ALSO INDICATING IT
WILL QUICKLY DISSIPATE AFTER 00Z. THUS HAVE INCLUDED PRE-FIRST
PERIOD POPS IN THE ZONES FORECAST TO CAPTURE THE EARLY POPS WHICH
DECREASE LATER THIS EVENING. THE DRY SUB-CLOUD LAYER COULD ALLOW
FOR GUSTY WINDS NEAR THE THUNDERSTORMS...BUT VERY LITTLE SHEAR
WILL PREVENT ANY SERIOUS THREAT FOR SEVERE THUNDERSTORMS.
RAIN CHANCES WILL CONTINUE THE NEXT SEVERAL DAYS AS AN UPPER LEVEL
LOW SLOWLY MOVES WEST ACROSS TEXAS AND INTO THE DESERT SOUTHWEST.
RAIN CHANCES WILL BE GREATEST TOMORROW...THEN WILL BE CONCENTRATED
WEST OF THE PECOS RIVER BEFORE ENDING LATE IN THE WEEK.
TEMPERATURES WILL BE AT OR SLIGHTLY BELOW NORMAL DEPENDING ON
PRECIP AND CLOUD COVERAGE...THEN WILL INCREASE ON THURSDAY AS THE
LOW EXITS AND UPPER HEIGHTS INCREASE IN RESPONSE TO A BUILDING
RIDGE.
HENNIG
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 70 94 69 93 / 10 30 10 10
BIG SPRING TX 72 95 70 95 / 10 30 10 10
CARLSBAD NM 69 97 68 96 / 10 30 20 30
DRYDEN TX 73 94 72 92 / 10 30 20 10
FORT STOCKTON TX 71 95 70 92 / 20 30 20 10
GUADALUPE PASS TX 67 85 65 86 / 20 30 30 30
HOBBS NM 66 94 66 91 / 10 30 20 10
MARFA TX 60 85 60 87 / 20 40 40 30
MIDLAND INTL AIRPORT TX 71 94 70 94 / 10 30 10 10
ODESSA TX 73 94 71 93 / 10 30 10 10
WINK TX 74 98 72 95 / 10 30 20 10
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
05/10
AREA FORECAST DISCUSSION
NWS SPOKANE WA
426 PM PDT Tue Jul 17 2012
.SYNOPSIS...
An unusually strong and moist upper level low will continue to
dominate our weather through Thursday. The presence of this low
will equate to localized showers and thunderstorms each day with
heavy rain at times. Another strong upper level low is expected
to move into the region via the Gulf of Alaska Thursday night and
Friday and will bring a better chance of thunderstorms. The
possibility of showers and thunderstorms will remain over the
northern mountains through the weekend...otherwise the forecast
will be dry.
&&
.DISCUSSION...
Tonight...A large closed low will remain along the Northern
California coast with southerly flow ahead of this low over the
Inland Northwest. The wave that brought thunderstorms to the
region Monday night and Tuesday will continue to pull away from
the area into Southern British Columbia through the evening.
Another wave over Oregon will weaken as it moves north into
Washington this evening. Net result for tonight should be much
less lightning activity compared to last night. However there is
plenty of instability this afternoon with surface based CAPES as
of 1 pm per LAPS data of 1500-2000 J/KG. A lack of forcing and a
weak cap has limited thunderstorm activity south of Highway 2
today but some cells are developing across Northeast Oregon, the
Blues, and Camas Prairie this afternoon that will be tracking
north tonight. These may weaken when coming off the higher terrain
but potential also exists for an outflow boundary to tap into the
strong instability for thunderstorms propagating north from the
Blues into the Palouse, Lewiston area, Upper Columbia Basin,
Spokane, and Coeur D`Alene areas. HRRR which has been handling the
convection reasonably well today suggests a better potential for
storms to come off the mountains and impact Pullman and Lewiston
so will indicate better thunder chances here and only slight
chance mention from Moses Lake to Spokane. This activity will
weaken after sunset although a lingering area of mid level
instability could trigger a stray thunderstorm overnight from the
Blues to the Central Panhandle Mountains. A secondary weak wave
with less instability will track across Southern BC overnight
which could bring a few showers to areas near the Canadian border.
Also with very moist low levels and a trend towards clearing skies
overnight will likely see some patchy fog in the northern valleys
as well as the Idaho Panhandle valleys. JW
Wednesday through Friday Evening...The models are actually in
pretty good agreement after showing numerous solution changes
over the past 2-3 days. The closed low that has been cut-off from
any steering flow will remain nearly stationary through Thursday.
Meanwhile the first upper level trough that was thought to nudge
the closed low out of the region will track meekly through
northern BC. A secondary low currently near the Aleutian chain
will track into the Gulf of Alaska. This low is progged by the
models to gain strength and result in the closed low getting
ejected northeast through the Pacific Northwest late Thursday
night and Friday. There are still some minor timing issues, but
this is the second run in a row for the majority of the models to
show this solution.
Wednesday through Thursday...As mentioned above the closed low
will continue to remain nearly stationary along the southwest
Oregon coast. Pacific moisture will continue to wrap around the
low and move into the Inland Northwest. The atmosphere will
remain unstable, however the difference from the past few days is
there will not be any robust short wave disturbances moving
through the region. Therefore convection for the area will rely on
surface based heating and orographics for shower and thunderstorm
initiation. So while showers and Thunderstorms are expected, they
should not be as widespread and should not be as active. Meanwhile
the models are indicating the passage of the closed low will hold
off 24 hours until Friday. Therefore temperatures for Thursday
have been increased with highs remaining warmer then normals.
Thursday night through Friday evening. The stronger secondary
upper level low is now progged by the models to begin pushing the
closed low inland Thursday night and Friday. There will be
abundant moisture to work with as PW`s will be well above an inch
which is 150-180 percent of normal. The trough becomes negatively
tilted through the night. This pattern is good for very active
thunderstorms and there is no reason not to think this will happen Thursday
night ad Friday. Instability parameters and 0-6km wind shear will
definitely be in place and the kicker will be provided by a mid-
level cold front that tracks from near the Washington/Oregon
Cascades at 06z Friday and is mainly east of the the forecast area
by Friday afternoon. Nocturnal thunderstorms tend to be high
based with gusty outflow winds and the chance of medium to large
hail. This should be case again Thursday and Friday, however
because of the amounts of moisture expected locally heavy rain will
result in localized urban and small stream flooding. Debris flows
will also be possible. /Tobin
Friday night through Tuesday: An upper level low pressure system
that kicks out the cut off low over the region for Friday will
make its way across British Columbia through this period. There
is some question how far south this low will actually get amongst
the latest 00Z model runs. The GFS keeps the low north of the
region; the Canadian is much further south with the center of the
low tracking right across eastern WA; and the ECMWF is right in
the middle, but is the strongest of the three. How far south this
low actually tracks will determine how much precipitation we get,
if any.
The Canadian model does not track this low very well and
actually retrogrades it a bit Monday into Tuesday. This idea does
not make any sense, especially since this low pressure system is
not expected to be cut off from the Polar Jet stream unlike the
past systems we have been experiencing. Thus, the Canadian run was
thrown out of my decision making process. The GEFS ensemble mean
is a nice compromise between the 00Z GFS and ECMWF operational
runs. This would swing the low pressure system through the region
Sunday afternoon through Monday afternoon. Kept a mention of a
slight chance of showers across the northern mountains. We could
see some thunderstorms, but it looks like the best instability
will remain to our north where British Columbia will have the best
shot at thunderstorms. This low will draw up some monsoonal
moisture from the south as well, but this moisture looks as if it will
remain to our south. However, we may see some showers and
thunderstorms that could track southwest to northeast from the
Northeast Blue Mountains into the Central Panhandle. Confidence is
too low to mention showers or thunderstorms across these areas at
this time. If this low decides to track even further south, then
temperatures will need to be lowered even more, but for now went
with temperatures near normal through Monday.
The general long wave trend after Monday continues to indicate that
there will be very little movement of the strong ridge of higher
pressure over the central United States and over the eastern
Pacific. This will allow the possibility for more weather systems
to dive southward over the eastern Pacific high down into the Pac
NW. At this time, I don`t see any other strong low pressure
systems that will track into the region after Monday. This should
result in more of a zonal flow pattern over the Northwest. It
looks like we will be lacking moisture, which should result in a
fairly dry forecast after Monday. We should see temperatures warming a
bit with highs slight above average for Tuesday. /SVH
&&
.AVIATION...
00Z TAFS: Convective showers and thunderstorms will continue to
develop over the Blue Mountains and track north towards KPUW/KLWS
and used VCTS to account for possible thunderstorms at these
terminals. These storms may survive the trip north to KGEG- KSFF-
KCOE but confidence is lower of storms impacting these sites with
the main threat being from 00z-04z. This activity should wind down
after 04z as the lower atmosphere stabilizes with the loss of day
time heating. Convection will develop again during the heating of
the day Wednesday with a slight chance of -TSRA affecting any TAF
site. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 87 62 89 62 82 / 20 20 20 30 30 50
Coeur d`Alene 61 86 59 89 60 80 / 20 20 20 30 30 60
Pullman 58 86 56 86 58 81 / 40 20 20 30 30 20
Lewiston 67 94 65 95 68 91 / 40 30 30 30 30 20
Colville 60 90 59 90 58 85 / 30 20 30 30 30 60
Sandpoint 58 85 56 89 55 79 / 20 20 20 30 30 60
Kellogg 60 85 57 90 57 82 / 20 20 20 30 30 60
Moses Lake 64 93 62 93 63 89 / 20 20 10 20 30 50
Wenatchee 68 92 65 94 65 88 / 20 20 10 20 40 40
Omak 64 94 62 95 62 88 / 30 20 10 20 40 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1104 PM PDT Sun Jul 15 2012
.SYNOPSIS...
Slow moving thunderstorms will bring locally heavy rain and the
potential for localized flooding to portions eastern Washington
tonight. Upper level low pressure will remain over the Pacific
Northwest Monday, Tuesday and Wednesday bringing humid conditions
and the chance for thunderstorms. Drier weather should return to
the region Thursday or Friday through next weekend.
&&
.DISCUSSION...
Main update was to adjust PoPs across the Palouse and eastern
Columbia Basin. Radar mosaic shows an area of showers and
thunderstorms moving north out of northeast Oregon. The RUC has the
best handle on these storms and indicates that this area will take
a turn to the northwest overnight. Continued easterly low level
flow will keep the threat of showers and a few thunderstorms going
over the western half of the forecast area through Monday evening.
The heaviest rainfall has diminished so all flood products have
been taken down or allowed to expire. /Kelch
&&
.AVIATION...
06Z TAFS: Scattered showers and thunderstorms will affect eastern
WA overnight. The most favored area will be west of KLWS/KPUW. The
main hazard from these storms will be very heavy rainfall and
possibly small hail. These storms will move northwest, affecting
the KMWH/KEAT sites by 10Z. Another round of convection will
develop Monday afternoon. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 60 87 65 88 65 83 / 20 20 30 20 40 50
Coeur d`Alene 58 86 62 87 62 82 / 10 20 30 40 40 50
Pullman 56 84 62 85 60 81 / 30 20 40 40 50 40
Lewiston 65 92 68 94 68 90 / 20 20 30 30 30 40
Colville 57 88 61 89 62 86 / 10 20 20 40 40 50
Sandpoint 56 84 59 85 59 81 / 10 20 30 50 40 50
Kellogg 57 86 59 86 58 81 / 10 20 30 40 40 60
Moses Lake 59 88 65 94 65 88 / 30 30 30 20 20 40
Wenatchee 62 87 67 94 68 88 / 40 30 20 30 30 40
Omak 61 93 66 94 66 90 / 30 20 20 30 30 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
706 PM CDT TUE JUL 17 2012
.SHORT TERM...THROUGH THURSDAY NIGHT
248 PM CDT TUE JUL 17 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A COLD FRONT ACROSS SOUTHERN
MINNESOTA INTO CENTRAL WISCONSIN. REGIONAL RADARS INDICATE STORMS
HAVE DEVELOPED NORTH OF THE FRONT ACROSS WISCONSIN.
THE CONVECTION ACROSS WISCONSIN HAS DEVELOPED IN RESPONSE TO A
WEAK SHORT WAVE TROUGH THAT DEVELOPED OUT OF THE STORMS OVER THE
DAKOTAS LAST NIGHT. THIS IS ALSO BEING AIDED BY THE RIGHT ENTRACE
REGION OF THE UPPER LEVEL JET OVER LAKE SUPERIOR. THE BEST CAPE
EXISTS ALONG AND AHEAD OF THE FRONT WITH AN AXIS OF 2500 J/KG OF
ML CAPE FROM CENTRAL INTO EAST CENTRAL WISCONSIN. AS THE WAVE
MOVES EAST THIS AFTERNOON...WOULD EXPECT THE CONVECTION TO
GRADUALLY SINK TO THE SOUTHEAST TOWARD THE HIGHER CAPE BUT MOST
SHOULD REMAIN BEHIND THE FRONT WHERE THERE IS NO CAP IN PLACE. THE
17.12Z HI-RES ARW AND 17.15Z HRRR SHOW THIS TREND OCCURRING WITH
THE BEST CHANCE OF ANYTHING CLIPPING THE AREA IN THE I94 CORRIDOR.
AFTER THIS EVENING THROUGH WEDNESDAY...ANY ACTIVITY THAT DEVELOPS
WILL BE CLOSELY TIED TO THE POSITION OF THE FRONT. THE 17.12Z
MODELS ALL HAVE DIFFERENT SOLUTIONS ON HOW FAR SOUTH THE FRONT
WILL GET BEFORE STALLING OUT. THE NAM AND GFS TAKE THE FRONT INTO
CENTRAL IOWA AND NORTHERN ILLINOIS TONIGHT WHILE THE 17.00Z ECMWF
HAS THE FRONT FROM NORTHERN IOWA ALONG THE WISCONSIN/ILLINOIS
BORDER. ALL THE MODELS SHOW JUST A SLOW SOUTHWARD DRIFT TO THE
FRONT WEDNESDAY. AT THIS POINT...NOT EXPECTING ANY SHORT WAVE
TROUGHS TO INTERACT WITH THE FRONT...BUT THAT COULD CHANGE IF
CONVECTION DEVELOPS OVER THE HIGH PLAINS TUESDAY NIGHT.
THE MODELS THEN DO SHOW A SHORT WAVE TROUGH COMING OUT OF THE FLOW
OVER THE ROCKIES AND TOPPING THE UPPER LEVEL RIDGE AND MOVING
ACROSS MINNESOTA AND WISCONSIN. AGAIN...THE POSITION OF THE FRONT
WILL HAVE A BIG IMPACT ON WHERE ANY CONVECTION MAY DEVELOP. WOULD
BE MORE ENTHUSED ABOUT THE RAIN CHANCES WITH THIS WAVE IF THERE
WAS ANY MOISTURE TRANSPORT OF SIGNIFIGANCE WITH THE WAVE. WITH THE
LACK OF RETURNING MOISTURE AND ANECEDENT DRY CONDTIONS...HAVE HELD
THE RAIN CHANCES FOR WEDNESDAY NIGHT AROUND 40 PERCENT. AS THIS
WAVE THEN EXITS OFF TO THE EAST THURSDAY...EXPECT THE RAIN TO MOVE
EAST AS WELL DURING THE DAY WITH A DRY THURSDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NORTH.
.LONG TERM...FRIDAY THROUGH TUESDAY
248 PM CDT TUE JUL 17 2012
THE HIGH THEN LOOKS TO REMAIN OVER THE AREA INTO THE START OF THE
WEEKEND BEFORE THE NEXT FRONT STARTS TO SINK INTO THE AREA.
CURRENT INDICATIONS ARE THAT THIS FRONT WILL MOVE SOUTH ACROSS THE
AREA FROM SATURDAY NIGHT THROUGH MONDAY. THE UPPER LEVEL RIDGE IS
STILL EXPECTED TO BE ANCHORED OVER THE CENTRAL PART OF THE COUNTRY
WITH THE BULK OF THE SHORT WAVE ENERGY RIDING UP OVER THE RIDGE
ACROSS SOUTHERN CANADA. NOT OUT OF THE REALM OF POSSIBILITY THAT
ONE OF THESE WAVES COULD TEMPORARILY FLATTEN THE RIDGE AND GET
INTO THE AREA...BUT WOULD NOT COUNT ON THIS HAPPENING. THUS ANY
RAIN WITH THE FRONT SHOULD STAY ON THE SCATTERED SIDE.
&&
.AVIATION...TONIGHT AND WEDNESDAY
657 PM CDT TUE JUL 17 2012
FRONTAL BOUNDARY LOOKS TO HAVE PASSED KLSE...AND SHOULD BE THROUGH
KRST IN THE NEXT FEW HOURS. CAPPING INVERSION LOOKS TO HAVE KEPT
THE THREAT FOR THUNDERSTORMS AT BAY FOR THE TIME BEING...WITH THE
FOCUS TO THE EAST OF THE TAF SITES. BUT WITH THE FRONT NEARBY...
WILL HAVE TO WATCH FOR ANY NEEDED CHANGES. OVERNIGHT...MODEL
GUIDANCE WAS TRYING TO HINT AT LIGHT FOG/MIST...BUT MODELS ALSO
HAD SOME RAIN IN THE AREA THIS EVENING ADDING MOISTURE. DO NOT
HAVE HIGH CONFIDENCE IN THIS SO REMOVED FROM THE TAFS. BEYOND
THAT...CONCERN BECOMES IF ANY CONVECTION FIRES AGAIN TOMORROW
AFTERNOON. THINK THIS IS POSSIBLE...BUT TIMING AND LOCATION ARE
DIFFICULT TO PIN DOWN. FOR NOW...JUST WENT WITH VCTS AND WILL
ATTEMPT TO REFINE FOR 06Z ISSUANCE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
248 PM CDT TUE JUL 17 2012
WI...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR WIZ041>044-053>055-
061.
MN...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ094>096.
IA...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...MW
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
247 PM CDT MON JUL 16 2012
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE MOVING EAST OVER WESTERN LAKE SUPERIOR AND THE ARROWHEAD OF
MINNESOTA. WIDELY SCT SHOWERS AND ISOLATED THUNDERSTORMS HAVE
SLOWLY BEEN FIZZLING IN THE WARM ADVECTION CORRIDOR AHEAD OF THE LOW
OVER THE UPPER PENINSULA AND FAR NORTHWEST WISCONSIN. MID-LEVEL
CONVERGENT CLOUD BAND STILL EXISTS ALL THE WAY TO THE DAKOTAS AND
WILL LEAVE A MENTION OF AN ISOLATED SHOWER OVER FAR N-C WISCONSIN
THROUGH THE REST OF THE AFTERNOON. THE COLD FRONT EXTENDING WEST
OVER THE NORTHERN PLAINS REMAINS MOSTLY INACTIVE SO FAR. THE OTHER
MAIN STORY HAS BEEN THE HEAT TODAY. MOST PLACES IN THE HEAT
ADVISORY ARE IN THE MID TO UPPER 90S AND WITH A FEW MORE HOURS OF
HEATING...HAVE NO PLANS TO TAKE DOWN THE HEADLINES. AS THE COLD
FRONT SLOWLY DROPS SOUTH ACROSS THE REGION OVER THE NEXT 24
HOURS...THUNDERSTORMS CHANCES AND HEAT RELATED HEADLINES ARE THE
MAIN FORECAST CONCERNS.
TONIGHT...LOW PRESSURE OVER NORTHERN MINNESOTA WILL MOVE EAST OVER
LAKE SUPERIOR AND INTO SOUTHEAST ONTARIO. TRAILING COLD FRONT WILL
SLOWLY DROP SOUTH INTO NORTHERN WISCONSIN LATE THIS EVENING AND
ACROSS MUCH OF NORTHERN WISCONSIN AFTER MIDNIGHT. AHEAD OF
FRONT...BAND OF ISENTROPIC ASCENT AND WEAK CONVERGENCE ON THE 310K
SURFACE...AS NOTED BY THE MID-LEVEL CLOUD BAND OVER CENTRAL
MINNESOTA AND THE UPPER PENINSULA...WILL DROP SOUTH ACROSS NORTHERN
WISCONSIN THIS EVENING. WILL LEAVE A SLIGHT CHANCE OF SHOWERS TO
ACCOUNT FOR THIS POSSIBILITY. TEND TO THINK BETTER CHANCES OF
PRECIPITATION WILL OCCUR AFTER MIDNIGHT THOUGH. LATEST MODELS
INDICATED THAT THE SHORTWAVE OVER SOUTHERN SASKATCHEWAN WILL SHEAR
AS IT MOVES ACROSS SW ONTARIO LATE. RIGHT REAR QUAD OF A JET STREAK
WILL BECOME COINCIDENT WITH THE ELEVATED FRONT WHERE CAPES WILL
REACH OVER 1000 J/KG WHEN LIFTED FROM 750MB. ADDITIONALLY...WILL
ALSO HAVE MODERATE 850-700MB FGEN OVER NORTHERN WISCONSIN AS WELL.
THE LATEST HIRES-WRF SHOWS SHOWERS AND STORMS DEVELOPING OVER THE
NORTHERN PLAINS THIS EVENING...WHERE THE AFOREMENTIONED FORCING WILL
EXIST...BEFORE MOVING EAST WITH THE FORCING INTO NORTHERN WISCONSIN
LATE. AS A RESULT...WILL KEEP LOW END CHANCE WORDING OVER N-C
WISCONSIN LIKE THE PREVIOUS FORECAST SHOWED...BUT BRING THE SLIGHT
CHANCES OF SHOWERS FARTHER SOUTH THIS EVENING. SHOULD BE A WARM AND
MUGGY NIGHT WITH LOWS MAINLY IN THE 70S EXCEPT OVER FAR N-C
WISCONSIN.
TUESDAY...THE COLD FRONT WILL DROP SOUTH THROUGH THE DAY AND FINALLY
CLEAR THE SOUTHERN CWA BETWEEN 21-00Z. POTENTIAL FOR SHOWERS AND
STORMS WILL CARRY OVER FROM LATE TONIGHT INTO TUESDAY MORNING NORTH
OF ROUTE 29. IN THE AFTERNOON...SURFACE BASED CONVECTION BECOMES A
POSSIBILITY THOUGH IT DOES CONTINUE TO LOOK MARGINAL. DESPITE MOST
MODELS SPITTING OUT PRECIP TOMORROW...THERE WILL BE CAPPING TO
OVERCOME ESPECIALLY IF DEWPOINTS MIX OUT AGAIN. THINK MOISTURE
POOLING ALONG THE FRONT WILL HELP MITIGATE THAT ISSUE SOMEWHAT
TOMORROW SO WILL LEAVE A LOW CHANCE OF STORMS OVER THE SOUTHERN HALF
OF FORECAST AREA. GIVEN THE MAGNITUDE OF THE CAPES (GREATER THAN
2000 J/KG)...ISOLD SVR WILL BE POSSIBLE BUT THE BETTER WIND FIELDS
WILL EXIST BEHIND THE FRONT SO STILL NOT EXPECTING ANY WIDESPREAD
POTENTIAL. WITH THE FRONT NOT CLEARING CENTRAL WISCONSIN UNTIL LATE
IN THE DAY...TEMPS WILL SOAR ONCE AGAIN TOMORROW. MID TO UPPER 90S
LOOKS DOABLE BUT WITH MORE HUMIDITY THANKS TO THE MOISTURE POOLING
ALONG THE BOUNDARY. WILL EXTEND THE HEAT ADVISORY FOR THE HOT SPOTS OF
WAUPACA AND WAUSHARA COUNTIES...AND ALSO FOR WINNEBAGO. WINDS DO
TURN NE BEHIND THE FRONT...AND SHOULD BRING COOLER LAKE AIR INTO THE
NORTHERN FOX VALLEY AND LAKE SHORE COUNTIES BEFORE POINTS FARTHER
WEST.
.LONG TERM...THU NGT THRU NXT MON. THREE MAIN DETAILS TO DECIPHER
DURING THE EXTENDED PERIOD. FIRST...HOW LONG WL ANY PCPN HANG
AROUND TUE NGT AS THE CDFNT CONTS TO SLOWLY SAG SWD? SECOND...WHAT
ARE THE PCPN CHCS WED NGT/THU WITH THE PASSAGE OF A MID-LEVEL
SHORTWAVE? LASTLY...WHAT IS THE TIMING OF SHORTWAVE ENERGY
EJECTING EWD FROM THE PACIFIC NW UPR TROF FOR NXT WEEKEND? TEMPS
WL COOL TO AROUND NORMAL MID-WEEK...BUT BEGIN A SLOW UPTICK TOWARD
NXT WEEKEND WITH ANOTHER ROUND OF 90+ MAX TEMPS.
THE WEST TO EAST ORIENTATED CDFNT WL SLOWLY SINK TOWARD THE WI/IL
BORDER TUE NGT WITH FRONTOGENETICALLY FORCED POST-FRONTAL SHWRS/
TSTMS CNTRL/E-CNTRL WI THRU MUCH OF THE NGT. MAY EVEN NEED TO
CARRY A SLGT CHC POP OVER PARTS OF THE NORTH DEPENDING ON HOW FAR
SOUTH THE FNT GETS ON TUE. COOLER AIR FILTERING INTO THE REGION WL
ALLOW FOR TEMPS TO DROP INTO THE 50S NORTH...60 TO 65 DEGS
ELSEWHERE.
ENUF OF A NW FLOW ALOFT STILL IN PLACE ON WED TO SEND THE CDFNT
INTO NRN IL...BUT WL HAVE TO WATCH FOR LINGERING PCPN CHCS WED
MORNING OVER CNTRL/E-CNTRL WI. A WEAK AREA OF HI PRES IS THEN FCST
TO MOVE INTO NRN SECTIONS OF THE GREAT LKS AND BRING DRIER AIR
INTO NE WI ON E-NE WINDS BY WED AFTERNOON. TEMPS THROUGHOUT THE
FCST AREA WL BE MUCH CLOSER TO NORMAL FOR MID-JULY WITH MOST
LOCATIONS IN THE LWR TO MID 80S AND DEW PTS SETTLING INTO THE 50S.
SOME MODEL DISCREPANCY ARISES WED NGT AS THE ECMWF MAINTAINS A
FAVORABLE FRONTOGENETICAL FORCING SIGNAL ACROSS THE SRN HALF OF
WI...WHILE THE MAJORITY OF THE OTHER MDLS SUGGEST THAT THIS WL NOT
OCCUR. SINCE THE ECMWF HAS BEEN HINTING AT THIS FOR A WHILE NOW...
DO NOT WISH TO DISCOUNT IT...THUS HAVE ADDED A SMALL POP FOR CNTRL
WI AFTER MIDNGT. A WEAK/LITTLE MID-LEVEL SHORTWAVE IS FCST TO DROP
SE FROM THE UPR MS VALLEY TOWARD IL ON THU ALONG THE BAROCLINIC
ZONE AIDED BY THE RIGHT ENTRANCE REGION OF THE UPR JET. WHILE THE
MDLS GENERALLY AGREE ON THIS SCENARIO...PCPN CHCS LOOK MINIMAL
BASED ON A LACK OF SFC FEATURE AND INSTABILITY. ACTUAL MDL QPF
LOCATION ALSO VARY FROM NRN WI TO SRN WI TO NONE AT ALL...THUS
A LOW END POP WL SUFFICE WITH MOST AREAS AGAIN MISSING OUT ON MUCH
NEEDED RAINFALL.
THIS SHORTWAVE SHOULD HAVE PULLED FAR ENUF AWAY BY THU EVENING
SUCH THAT THE SLGT CHC POPS WERE REMOVED. OTHERWISE...MAIN STORY
FOR THU NGT INTO FRI WL BE THE RISING UPR HEIGHTS AS THE LARGE AND
DOMINANT UPR RDG OVER THE CNTRL CONUS EDGES A BIT FARTHER EAST.
LOOK FOR MAX TEMPS ON FRI TO START EDGING UPWARD WITH READINGS
RANGING FROM THE LWR 80S NORTH/LAKESHORE TO THE MID TO UPR 80S
CNTRL/E-CNTRL WI.
FCST CONTINUITY BREAKS DOWN NXT WEEKEND BETWEEN OPERATIONAL MDLS
AND ENSEMBLE MEANS. THE GFS/CANADIAN MDLS WANT TO QUICKLY RACE A
PIECE OF MID-LEVEL ENERGY EWD ACROSS EXTREME SRN CANADA BEFORE
TURNING SE INTO THE WRN GREAT LKS AS EARLY AS SAT. THE ECMWF IS
MUCH SLOWER (BY 18 HOURS). MEANWHILE...THE ECMWF AND GFS ENSEMBLE
MEANS ARE EVEN SLOWER YET. THIS PLACES PLENTY OF DOUBT AS TO
EXACTLY WHEN TO BRING THE NXT CHC OF PCPN TO THE FCST AREA.
BETWEEN THE KNOWN FAST BIAS OF THE GFS COUPLED WITH THE LOCATION
OF THE UPR RDG (POKING NE TOWARD WI)...FEEL THE SLOWER WAY IS THE
PROPER CALL. THEREFORE...HAVE KEPT SAT DRY AND VERY WARM WITH MAX
TEMPS RANGING FROM THE MID 80S TO LWR 90S.
WL NEED TO CARRY SOME SORT OF POP FOR SAT NGT INTO SUNDAY AS THE
MID-LEVEL ENERGY FINALLY DOES REACH THE WRN GREAT LKS ACCOMPANIED
BY A WEAK CDFNT. IT WOULD APPEAR THAT THE BETTER CHCS OF ACTUALLY
SEEING MEASURABLE PCPN WL AGAIN BE ACROSS THE NORTH WHERE THE CAP
IS WEAKER AND THE FNT APPROACHES AT PEAK HEATING. THE FNT REACHES
CNTRL/E-CNTRL WI SUNDAY NGT WHICH IS TYPICALLY NOT GOOD TIMING
WITH THE LOSS OF HEATING. IF THE FNT IS STILL CLOSE ENUF HEADED
INTO MON...THERE WOULD BE A POTENTIAL OF SEEING SHWRS/TSTMS
DEVELOP OVER SRN SECTIONS OF THE FCST AREA.
&&
.AVIATION...LOW PRESSURE WILL BE PASSING OVER LAKE SUPERIOR TODAY.
SW WINDS WILL BE GUSTY THIS AFTERNOON WITH GUSTS UP TO 25 OR
POSSIBLY EVEN 30 KTS POSSIBLE OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN. GUSTY WINDS WILL DIMINISH THIS EVENING AS A COOL FRONT
TRAILING BEHIND THE SURFACE LOW SLOWLY SHIFTS SOUTH OVER NORTH
WISCONSIN. MARGINAL POTENTIAL FOR LLWS...MAINLY OVER CENTRAL AND
EAST-CENTRAL WISCONSIN. PLENTY OF UNCERTAINTY FOR SHOWERS AND
THUNDERSTORMS ALONG THE FRONT TONIGHT INTO TOMORROW. LATEST
THINKING IS FOR ISOLATED TO SCT COVERAGE OVER NORTHERN WISCONSIN
LATE TONIGHT INTO TOMORROW MORNING...AND ISOLATED COVERAGE OVER
CENTRAL AND EAST-CENTRAL WISCONSIN TOMORROW AFTERNOON. COVERAGE AT
THIS TIME REMAINS MARGINAL ENOUGH TO EXCLUDE FROM TAFS.
MPC
&&
.MARINE...THE COOL FRONT CROSSING THE AREA TUE WL LIKELY HAVE A
SIG IMPACT ON BOATERS ON THE LAKE AND BAY. TIMING STILL A LITTLE
DIFFICULT TO GAUGE...BUT BALLPARKING IT WOULD HAVE A WIND SHIFT
OCCURRING BETWEEN 19-21Z. BUT EXPECT WLY WINDS OF 5-10 KTS AHEAD OF
THE FRONT TO ABRUPTLY SHIFT TO THE NE...WITH GUSTS OF 25-30 KTS FOR
A COUPLE HRS AFTER FROPA. THAT COULD ALSO RESULT IN SEAS QUICKLY
GETTING VERY CHOPPY. SHORT DURATION OF THE CONDITIONS AND THE ABRUPT
ONSET SUGGEST SITN PROBABLY BEST HANDLED WITH MARINE WX STATEMENT
RATHER THAN A SMALL CRAFT ADVISORY. BUT ADDED MENTION OF CONDITIONS
INTO HWO TO GIVE BOATERS A HEADS-UP ON THE SITN IF THEY ARE PLANNING
TO GO OUT ON THE LAKE OR BAY TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR WIZ037-045-048.
HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR WIZ020-021-030-031-
035-036-038>040-049-050-073-074.
&&
$$
MPC/AK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1143 PM CDT SUN JUL 15 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED ON THE MONTANA-NORTH DAKOTA BORDER AND ITS ASSOCIATED WARM
FRONT EXTENDING ACROSS THE DAKOTAS. YESTERDAYS UPPER TROUGH HAS
MOVED TO THE EASTERN GREAT LAKES. WISCONSIN LIES BETWEEN THESE TWO
FEATURES IN A REGION OF BUILDING HEIGHTS ALOFT. DIURNAL CU HAS
POPPED OVER CENTRAL AND NORTH-CENTRAL WISCONSIN AND AREA RADARS HAVE
DETECTED A SOLE SPRINKLE THAT DEVELOPED EARLIER OVER THE
PORTAGE/WAUPACA BORDER. THE CU LOOKS RATHER FEISTY SO WILL ADD AN
ISOLATED SPRINKLE MENTION FOR THE REST OF THE AFTERNOON. AS THE MID-LEVEL
RIDGE BUILDS INTO OUR AREA...THE MAIN FORECAST CONCERNS INCLUDE
CLOUDS AND TEMPS INCLUDING HEAT HEADLINES OVER THE NEXT 24 HOURS.
TONIGHT...LOW PRESSURE WILL MOVE NE OVER THE NORTHERN PLAINS AND
HIGH PRESSURE WILL REMAIN CENTERED OVER THE SE CONUS. UPSTREAM
MID-DECK AND CIRRUS WILL LIKELY MAKE IT AT LEAST OVER THE NORTHERN
HALF OF THE FORECAST AREA TONIGHT AND LIGHT AND VARIABLE WINDS AT
THE SURFACE WILL PICK UP LATE. THESE CONDITIONS POINT TOWARDS
A WARMER NIGHT AND WILL GO WITH LOWS RANGING THROUGH THE 60S.
MONDAY...UPSTREAM LOW PRESSURE WILL MOVE EAST OVER NORTHERN
MINNESOTA AND WESTERN LAKE SUPERIOR. AS THIS OCCURS...A COLD FRONT
WILL SAG INTO NORTHWEST WISCONSIN LATE IN THE DAY...BUT AIRMASS
AHEAD OF THE FRONT IS PRETTY DRY...SO THINKING THERE IS SLIM CHANCES
OF A COOLING THUNDERSTORM. WILL LEAVE A SLIGHT CHANCE OVER FAR
NORTHERN VILAS IN CASE A ROGUE STORM DECIDES TO MAKE A RUN TOWARDS
THE NORTHERN TIP OF THE COUNTY. OTHERWISE...THE HEAT WILL BE THE
MAIN STORY TOMORROW. THE LATEST GUIDANCE SHOWS 850MB TEMPS IN THE
24-25C RANGE WHICH WOULD PUT HIGHS NEAR 100F. A TIGHTENING PRESSURE
GRADIENT WILL SUPPORT GOOD MIXING GREATER THAN 800MB...AND HELP TO
MIX OUT DEWPOINTS INTO THE LOW TO MID 60S. BUT THE GOOD MIXING ALSO
SUPPORTS GOING ON THE WARM SIDE OF GUIDANCE...WHICH PLACES HIGHS IN
THE MID TO UPPER 90S OVER CENTRAL AND EAST-CENTRAL WISCONSIN...AND
LOW TO MID 90S FARTHER NORTH. SOME 100S WILL LIKELY BE REACHED IN
THE HOT SPOTS AROUND WAUPACA AND WAUSHARA. ONLY CONCERN WITH TEMPS
IS THE MID AND HIGH LEVEL MOISTURE UPSTREAM...THOUGH ITS TOUGH TO
GAUGE HOW THICK IT WILL BE TOMORROW. BECAUSE DEWPOINTS WILL LIKELY
BE MIXING OUT...THINK HEAT INDICES MAY STRUGGLE TO REACH ADVISORY CRITERIA
OVER CENTRAL WISCONSIN. NONETHELESS...NO POINT IN CANCELLING
HEADLINES AT THIS POINT AS POTENTIAL WILL STILL BE THERE AND IT WILL
BE VERY HOT.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY.
CONTINUE TO DEAL WITH FLUCTUATIONS IN POSITION/STRENGTH OF STRONG
CENTRAL U.S. RIDGE WITH SYSTEMS EJECTING OUT OF WESTERN TROF THROUGH
CANADA. TEMPERATURES EXPECTED TO START OUT WARM...THEN RETURN TO
NEAR NORMAL LEVELS BEFORE HEATING UP AGAIN ON THE WEEKEND.
INITIALLY WILL BE DEALING WITH COOL FRONT MOVING INTO/THROUGH CWA
MONDAY NIGHT AND TUESDAY. MAIN FORCING WITH UPPER JET REMAINS OVER
THE NORTH...PULLS OUT TUE NIGHT. SOME INSTABILITY...THOUGH
LIMITED. NAM STRONGER WITH SURFACE LOW...FASTER WITH FRONT
PASSING...AND SHOWS DRY FRONTAL PASSAGE. EC ON SLOWER END OF
GUIDANCE WITH SYSTEM AND FOR PAST TWO RUNS SUGGESTS MCS/S MAY MOVE ALONG
FRONT TUE NIGHT/WED OVER SOUTHERN HALF OF STATE. NOT SEEING ANY SIG
FORCING FOR SCENARIO...EXCEPT FOR SOME RELATIVELY WEAK WAA OVER
MN/SD. FEW TEMPS/HEAT INDICES REACH ADVISORY LEVELS TUE AFTN OVER
THE SOUTH...BUT WILL NOT EXTEND CURRENT ADVISORY GIVEN CLOUD/PCPN
CONCERNS. CWA REMAINS ON EDGE OF SEE TEXT BY SPC FOR MONDAY NIGHT
INTO TUE NIGHT. SHEAR IS LIMITED...THOUGH COULD SEE SOME GUSTY
WINDS AND MARGINAL HAIL WITH SOME TO THE STORMS IF THEY DEVELOP.
FRONT WILL SAG SOUTH INTO NORTHERN ILLINOIS ON WEDNESDAY WITH DRY
CANADIAN HIGH PRESSURE MOVING IN FOR WED-FRI PERIOD.
SPREAD SEEN IN ENSEMBLES FOR THE WEEKEND...WITH RIDGE
POSITION/STRENGTH...THOUGH MEANS SUGGEST GOING ON THE WARM
SIDE.
&&
.AVIATION...VFR EXPECTED TONIGHT AND MONDAY WITH JUST SOME MIDDLE
AND HIGH CLOUDS AND AN ISOLATED SHOWER POSSIBLE. SUNNY AND HOT
WEATHER IS EXPECTED MONDAY.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 9 PM CDT MONDAY FOR WIZ020-021-030-
031-035>040-045-048>050-073-074.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1108 PM MDT TUE JUL 17 2012
.AVIATION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE ACROSS THE
SOUTHEAST COLORADO PLAINS UNTIL A LITTLE AFTER MIDNIGHT. CONDITIONS
WEDNESDAY LOOK VERY SIMILAR TO TUESDAY WITH CHANCES FOR AFTERNOON
THUNDERSTORMS MOST AREAS AFTER 18Z. PRIMARY STORM THREATS WILL
INCLUDE LIGHTNING...WIND GUSTS TO AROUND 45 MPH...HEAVY RAIN AND
POCKETS OF SMALL HAIL. MVFR CONDITIONS POSSIBLE WITH STORMS. LOCAL
IFR CONDITIONS POSSIBLE UNDER MOST INTENSE CELLS. LW
&&
.PREV DISCUSSION... /ISSUED 317 PM MDT TUE JUL 17 2012/
SHORT TERM...
(TONIGHT AND WEDNESDAY)
CURRENT WATER VAPOR IMAGERY TELLING THE STORY WITH MUCH DRIER AIR
ACROSS WESTERN COLORADO MOVING INTO CENTRAL AND EASTERN COLORADO
ALONG WITH SUBSIDENCE ASSOCIATED WITH UPPER LEVEL RIDGING ACROSS THE
SOUTHERN HIGH PLAINS AND SOUTHERN ROCKIES BUILDING INTO THE CENTRAL
ROCKIES...HAS HELPED TO TAME CONVECTION ACROSS THE AREA THROUGH THE
EARLY AFTERNOON. REGIONAL RADARS STILL INDICATING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN...WITH
THE BEST COVERAGE ACROSS THE SOUTHWEST AND CENTRAL MTS AT THIS TIME.
RADAR DATA ALSO INDICATING A FEW CELLS POPPING ACROSS KIOWA COUNTY AT
THIS TIME. SATELLITE AND VISUAL INSPECTION INDICATING CU ACROSS THE
EASTERN MTS SHOWING MORE VERTICAL DEVELOPMENT AS WELL. AT THE
SFC...WEAK FRONTAL BOUNDARY HAS PUSHED THROUGH ALL OF THE SOUTHEAST
PLAINS WITH LATEST DATA INDICATING LOWER PRESSURES ACROSS THE LEE OF
THE ROCKIES AT THIS TIME.
TONIGHT...WITH A FEW MORE HOURS OF HEATING ALONG WITH WINDS BECOMING
MORE UPSLOPE ACROSS THE EASTERN PLAINS...SHOULD CONTINUE TO SEE
ISOLATED TO SCATTERED STORMS FIRING ACROSS THE HIGHER TERRAIN
THROUGH THE EARLY EVENING...WITH A FEW STORMS FIRING ACROSS THE
IMMEDIATE ADJACENT PLAINS THROUGH THE FAR SE PLAINS. LATEST HIGHER
RESOLUTION HRRR MODEL CONTINUES TO INDICATE SCATTERED STORMS FIRING
ACROSS THE PIKES PEAK REGION THROUGH THE EARLY EVENING WITH THE
DEVELOPING LOW LEVEL UPSLOPE. THIS STILL POSES A THREAT FOR LOCALLY
HEAVY RAINFALL WITH WEAK WESTERLY FLOW ALOFT ACROSS THE EASTERN MTS
AT THIS TIME. NOT AS CONCERNED WITH THE HEAVY RAIN THREAT ACROSS
WESTERN PORTIONS OF THE AREA WITH FLOW ALOFT A TAD FASTER WITH DEW
PTS DOWN INTO THE 30S AT THIS TIME. CLEARING SKIES EXPECTED THROUGH
THE OVERNIGHT AND HAVE FOLLOWED CLOSER TO THE COOLER SIDE OF
GUIDANCE FOR OVERNIGHT LOWS.
WEDNESDAY...UPPER LEVEL RIDGING CONTINUES TO BUILD ACROSS THE
CENTRAL ROCKIES AND INTO THE NORTHERN ROCKIES WITH UPPER FLOW
BECOMING MORE SOUTHERLY ACROSS WESTERN PORTIONS OF THE AREA AND
MORE NORTHERLY ACROSS EASTERN PORTIONS OF THE STATE...THOUGH
REMAINING WEAK. MOISTURE PLUME ACROSS EASTERN COLORADO GETS PUSHED
SOUTH AND EAST OF THE AREA...THOUGH ENOUGH MOISTURE TO REMAIN
UNDERNEATH BUILDING RIDGE TO SUPPORT MORE ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE AREA...WITH BEST COVERAGE OVER
THE HIGHER TERRAIN. LATEST NAM CONTINUES TO INDICATED STORMS FIRING
ALONG OLD BOUNDARY ACROSS THE NEW MEXICO BORDER IN THE LATE
AFTERNOON WITH THE GFS KEEPING THE BOUNDARY WELL SOUTH OF THE AREA.
AT ANY RATE...HAVE KEPT ISOLATED POPS ACROSS THE FAR SOUTHEAST
PLAINS WITH CONVECTIVE TEMPS IN THE MID 90S BEING REACHED. WITH
DRIER AIR ACROSS REGION...HEAVY RAIN THREAT DIMINISHES...THOUGH A
LOCALLY HEAVY RAINER WILL STILL BE POSSIBLE WITH THE WEAK FLOW ALOFT.
TEMPERATURES LOOK TO BE AROUND OR SLIGHTLY WARMER THAN TODAY. -MW
LONG TERM...
STAGNANT WX PATTERN WILL BE OVER THE REGION DURING THIS FCST PD.
CENTER OF MID LVL HI PRESSURE SYSTEM WILL DEVELOP PRETTY MUCH OVER
THE E PLAINS OF CO. THIS WILL FORCE THE MAIN MSTR PLUME TO THE WEST
OF THE FCST AREA...GENERALLY FROM THE CONTDVD ON WEST. EAST OF THE
CONTDVD IT WILL GENERALLY BE DRY...ESPECIALLY OVER THE PLAINS. WITH
THE HIGH DIRECTLY OVERHEAD...MAX TEMPERATURES ON THE PLAINS WILL
LIKELY GET UP INTO THE 100S AND REMAIN THERE THROUGHOUT THE FCST PD.
OVERALL THROUGH THIS FCST PD...I EXPECT SCTD AFTERNOON POPS OVER
THE CONTDVD...ISOLD POPS OVER THE REST OF THE MTNS AND VALLEYS...AND
HOT AND DRY ELSEWHERE.
GIVEN THE LOCATION OF THE MID LEVEL HIGH PRESSURE CELL DURING THIS
PERIOD...THE PROBABILITY OF FLASH FLOODING OVER THE WALDO BURN SCAR
WILL LIKELY BE LESS THAN NORMAL. /34
AVIATION...
ISOLATED TO SCATTERED STORMS TO REMAIN POSSIBLE ACROSS THE HIGHER
TERRAIN THROUGH THE EARLY EVENING...WITH A FEW STORMS SPREAD EAST
ACROSS THE IMMEDIATE ADJACENT PLAINS. BEST CHANCES OF AFFECTING
TERMINALS STILL REMAINS AT COS THROUGH 02Z WITH BRIEF MVFR CIGS AND
VIS ALONG WITH GUSTY OUTFLOW WINDS OF 25-35KTS POSSIBLE WITH STORMS.
VFR CONDITIONS WITH CLEARING SKIES AFT 06Z. AFTERNOON CONVECTION
TOMORROW TO REMAIN MORE OVER THE HIGHER TERRAIN. -MW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
50/27
AREA FORECAST DISCUSSION
NWS NEW YORK NY
508 AM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OUTSIDE OF A FEW ISOLATED SHOWERS THIS MORNING FROM INTERACTION
BETWEEN LOW LEVEL JET AND APPROACHING MID LEVEL DISTURBANCE...DRY
WEATHER EXPECTED WITH RELATIVELY WARM CONDITIONS THIS MORNING.
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF A VERY HOT
AIRMASS...DAY START OUT VERY WARM AND LARGE CAPE IN THE 2000 TO
4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL WARMING. SHEAR
OF 30 KT 0-6KM WITH WETBULB ZERO HEIGHTS OF 13-14 KFT. MENTIONED
GUSTY WINDS AND SMALL HAIL WITH SOME CELLS POSSIBLY GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES
WIDESPREAD...AT LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE
ENOUGH SUN TO HAVE HIGHS WELL INTO THE 90S AND WITH VERY MOIST
AIRMASS CONVEYED BY PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER
70S...HEAT INDICES ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW
YORK CITY AS WELL AS URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST
OF NE NJ AND WESTERN LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IF ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. SHEAR OF 25
TO 30 KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE
HAIL AND GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO
POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
FOR TONIGHT...BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT. IN THE UPPER
LEVELS AT 500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE
TROUGH SETTING UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER
GUIDANCE FOR HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING
ANY THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN IN THE VICINITY THIS
MORNING...THEN A COLD FRONT MOVES INTO THE TERMINALS DURING THE
AFTERNOON...MOVING SOUTH THIS EVENING.
MAINLY VFR OUTSIDE OF TSTMS...ALTHOUGH HZ MAY RESTRICT VSBY TO
AROUND 6SM ACROSS COASTAL TERMINALS. OCCASIONAL GUSTY SW WINDS AT
NYC/NJ TERMINALS FROM MID MORNING ON.
ISOLATED TSTMS POSSIBLE BY LATE MORNING...BECOMING LIKELY IN THE
EARLY AFTERNOON AND CONTINUING INTO THE EARLY EVENING. THREAT OF
GUSTY WINDS...HAIL AND HEAVY RAINFALL EXISTS WITH STONGER
CONVECTION. CONVECTION EXPECTED TO TAPER AND WEAKEN DURING THROUGH
THE EVENING HOURS.
HYBRID SEABREEZE AND SW FLOW ACROSS COASTAL TERMINALS THIS
AFTERNOON.
...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: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. HYBRID SEABREEZE/SW FLOW THIS AFTERNOON.
KLGA FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS.
KEWR FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING
THROUGH THE AFTERNOON.
KHPN FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING
THROUGH THE AFTERNOON.
KISP FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. HYBRID SEABREEZE/SW FLOW THIS AFTERNOON.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.LATE TONIGHT...MAINLY VFR...EXCEPT PATCHY GROUND FOG ACROSS
OUTLYING TERMINALS.
.THURSDAY-THURSDAY EVENING...VFR. SCATTERED SHOWERS POSSIBLE.
.LATE THURSDAY NIGHT-SATURDAY MORNING...CEILINGS 1500 FT TO 2500 FT
POSSIBLE...BEST CHANCE AT SOUTHERN/COASTAL TERMINALS.
.SATURDAY AFTERNOON-SUNDAY...VFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE ACROSS OCEAN WATERS LATER
TODAY AND TONIGHT. HOWEVER...KEPT SEAS BELOW 5 FT SINCE WAVEWATCH
INITIALLY ABOUT A FOOT TOO HIGH. SUB SCA EXPECTED ON THURSDAY AND
THURSDAY NIGHT.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVSY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NYZ071-078-080-177-179.
NJ... HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NJZ004-006-103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...NV
MARINE...24/JM
HYDROLOGY...24/JM
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
440 AM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OUTSIDE OF A FEW ISOLATED SHOWERS THIS MORNING FROM INTERACTION
BETWEEN LOW LEVEL JET AND APPROACHING MID LEVEL DISTURBANCE...DRY
WEATHER EXPECTED WITH RELATIVELY WARM CONDITIONS THIS MORNING.
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF A VERY HOT
AIRMASS...DAY START OUT VERY WARM AND LARGE CAPE IN THE 2000 TO
4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL WARMING. SHEAR
OF 30 KT 0-6KM WITH WETBULB ZERO HEIGHTS OF 13-14 KFT. MENTIONED
GUSTY WINDS AND SMALL HAIL WITH SOME CELLS POSSIBLY GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES WIDESPREAD...AT
LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE ENOUGH SUN TO HAVE
HIGHS WELL INTO THE 90S AND WITH VERY MOIST AIRMASS CONVEYED BY
PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER 70S...HEAT INDICES
ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW YORK CITY AS WELL AS
URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST OF NE NJ AND WESTERN
LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IF ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. SHEAR OF 25
TO 30 KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE
HAIL AND GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO
POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
FOR TONIGHT...BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT. IN THE UPPER
LEVELS AT 500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE
TROUGH SETTING UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER
GUIDANCE FOR HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING
ANY THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN IN THE VICINITY INTO WEDNESDAY
MORNING...THEN A COLD FRONT MOVES INTO THE TERMINALS DURING THE
AFTERNOON...MOVING SOUTH WEDNESDAY EVENING.
MAINLY VFR OUTSIDE OF TSTMS...ALTHOUGH HZ MAY RESTRICT VSBY TO
AROUND 6SM. OCCASIONAL GUSTY SW WINDS AT NYC/NJ TERMINALS FROM MID
MORNING ON.
THUNDERSTORMS WILL BECOME LIKELY BY EARLY AFTERNOON AND CONTINUE
INTO THE EARLY EVENING...WITH THE THREAT OF GUSTY WINDS...HAIL
AND HEAVY RAINFALL. CONVECTION EXPECTED TO TAPER AND WEAKEN DURING
THROUGH THE EVENING HOURS.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.LATE TONIGHT...MAINLY VFR...EXCEPT PATCHY GROUND FOG ACROSS
OUTLYING TERMINALS.
.THURSDAY-THURSDAY EVENING...VFR. SCATTERED SHOWERS POSSIBLE.
.LATE THURSDAY NIGHT-SATURDAY MORNING...CEILINGS 1500 FT TO 2500 FT
POSSIBLE...BEST CHANCE AT SOUTHERN/COASTAL TERMINALS.
.SATURDAY AFTERNOON-SUNDAY...VFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE ACROSS OCEAN WATERS LATER
TODAY AND TONIGHT. HOWEVER...KEPT SEAS BELOW 5 FT SINCE WAVEWATCH
INITIALLY ABOUT A FOOT TOO HIGH. SUB SCA EXPECTED ON THURSDAY AND
THURSDAY NIGHT.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVSY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NYZ071-078-080-177-179.
NJ... HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NJZ004-006-103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...NV
MARINE...24/JM
HYDROLOGY...JM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
424 AM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OUTSIDE OF A FEW ISOLATED SHOWERS THIS MORNING FROM INTERACTION
BETWEEN LOW LEVEL JET AND APPROACHING MID LEVEL DISTURBANCE...DRY
WEATHER EXPECTED WITH RELATIVELY WARM CONDITIONS THIS MORNING.
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF A VERY HOT
AIRMASS...DAY START OUT VERY WARM AND LARGE CAPE IN THE 2000 TO
4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL WARMING. SHEAR
OF 30 KT 0-6KM WITH WETBULB ZERO HEIGHTS OF 13-14 KFT. MENTIONED
GUSTY WINDS AND SMALL HAIL WITH SOME CELLS POSSIBLY GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES WIDESPREAD...AT
LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE ENOUGH SUN TO HAVE
HIGHS WELL INTO THE 90S AND WITH VERY MOIST AIRMASS CONVEYED BY
PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER 70S...HEAT INDICES
ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW YORK CITY AS WELL AS
URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST OF NE NJ AND WESTERN
LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IF ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. SHEAR OF 25
TO 30 KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE
HAIL AND GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO
POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
FOR TONIGHT...BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT. IN THE UPPER
LEVELS AT 500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE
TROUGH SETTING UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER
GUIDANCE FOR HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING
ANY THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN IN THE VICINITY INTO WEDNESDAY
MORNING...THEN A COLD FRONT MOVES INTO THE TERMINALS DURING THE
AFTERNOON...MOVING SOUTH WEDNESDAY EVENING.
MAINLY VFR OUTSIDE OF TSTMS...ALTHOUGH HZ MAY RESTRICT VSBY TO
AROUND 6SM. OCCASIONAL GUSTY SW WINDS AT NYC/NJ TERMINALS FROM MID
MORNING ON.
THUNDERSTORMS WILL BECOME LIKELY BY EARLY AFTERNOON AND CONTINUE
INTO THE EARLY EVENING...WITH THE THREAT OF GUSTY WINDS...HAIL
AND HEAVY RAINFALL. CONVECTION EXPECTED TO TAPER AND WEAKEN DURING
THROUGH THE EVENING HOURS.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.LATE TONIGHT...MAINLY VFR...EXCEPT PATCHY GROUND FOG ACROSS
OUTLYING TERMINALS.
.THURSDAY-THURSDAY EVENING...VFR. SCATTERED SHOWERS POSSIBLE.
.LATE THURSDAY NIGHT-SATURDAY MORNING...CEILINGS 1500 FT TO 2500 FT
POSSIBLE...BEST CHANCE AT SOUTHERN/COASTAL TERMINALS.
.SATURDAY AFTERNOON-SUNDAY...VFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE ACROSS OCEAN WATERS LATER
TODAY AND TONIGHT. HOWEVER...KEPT SEAS BELOW 5 FT SINCE WAVEWATCH
INITIALLY ABOUT A FOOT TOO HIGH. SUB SCA EXPECTED ON THURSDAY AND
THURSDAY NIGHT.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVSY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NYZ071-078-080-177-179.
NJ... HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NJZ004-006-103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...NV
MARINE...24/JM
HYDROLOGY...JM
AREA FORECAST DISCUSSION
NWS ALBANY NY
411 AM EDT WED JUL 18 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY MOVE SOUTHWARD ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND TODAY WITH SOME SHOWERS AND THUNDERSTORMS. A
BROAD AREA OF HIGH PRESSURE WILL BUILD IN FROM JAMES BAY TONIGHT
INTO THURSDAY WITH SEASONABLE TEMPERATURES AND LESS HUMID
CONDITIONS. A DISTURBANCE MOVING ALONG THE OLD FRONTAL BOUNDARY
OVER THE UPPER MID ATLANTIC REGION MAY BRING A FEW SHOWERS TO
LOCATIONS SOUTH OF THE CAPITAL REGION THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 4 AM EDT...ONE MORE HUMID DAY IS EXPECTED ACROSS ERN NY AND
WRN NEW ENGLAND...AS RELIEF IS ON THE WAY WITH A COLD FRONT SLOWLY
MOVING S/SE FROM THE ST LAWRENCE RIVER VALLEY THIS MORNING. A
MOIST AIR MASS IS IN PLACE WITH SFC DEWPTS IN THE M60S TO L70S
OVER THE FCST AREA. A LULL IN THE CONVECTIVE ACTIVITY HAS OCCURRED
OVER THE PAST FEW HOURS...BUT CONVECTIVE INITIATION SHOULD
INCREASE QUICKLY IN THE LATE MORNING AND EARLY PM.
GENERAL THINKING HAS NOT CHANGED TOO MUCH WITH THE BEST DEEP SHEAR
AND INSTABILITY COMPOSITE OVERLAYS FROM THE NAM/GFS FOR LOCATIONS
JUST SOUTH AND EAST OF THE CAPITAL DISTRICT FOR POSSIBLE SVR WX TODAY.
CAUTION HAS TOO BE USED WITH THE GFS INSTABILITY CHARTS...AS SFC
DEWPTS ARE WELL INTO THE M70S OVER A LARGE CHUNK OF THE AREA SOUTH
OF ALBANY. A CORRECTION TO U60S TO L70S STILL YIELDS SBCAPE VALUES
IN THE 1000-2000 J/KG WITH SLIGHTLY HIGHER AMOUNTS. THE DEEP SHEAR
VALUES ARE ON THE NORTH SIDE OF THE BOUNDARY WITH 45-60
KTS. HOWEVER...0-6 KM BULK SHEAR VALUES ON THE NAM/GFS ARE STILL
30-40 KT FROM ALY SOUTH AND EAST. THERE MAY BE ENOUGH CONVERGENCE
AND LIFT WITH THE BOUNDARY FOR A FEW STRONG TO SEVERE STORMS. WE
ARE GOING TO DEVIATE SLIGHTLY FROM THE LATEST DAY 1 GRAPHIC...AND
FOCUS ON THE SEVERE THREAT FOR MAINLY THE ERN CATSKILLS...MID
HUDSON VALLEY...CNTRL AND SRN TACONICS...BERKSHIRES...AND NW CT.
THE COUNTIES WE WILL HIGHLIGHT IN THE HWO WILL BE
GREENE...ULSTER...COLUMBIA...DUTCHESS...BERKSHIRE...AND
LITCHFIELD.
PWAT VALUES WILL STILL BE IN THE 1.50-2.00 INCH RANGE FROM THE
CAPITAL REGION...MOHAWK VALLEY SOUTH AND EAST. SOME LOCALLY HEAVY
DOWNPOURS WILL BE POSSIBLE...AND SOME LOCATIONS COULD GET A QUICK
INCH OR TWO OF RAIN. FLASH FLOODING IS NOT EXPECTED. ALSO...THE
STRONG FLOW ALOFT SHOULD CONTINUE TO MOVE THE CONVECTION ALONG
DURING THE DAY.
CONVECTIVE INITIATION SHOULD OCCUR QUICKER TODAY WITH AN ERODING
CAP...AND THE CLOSER PROXIMITY OF THE FRONTAL BOUNDARY. THE
THUNDERSTORMS SHOULD POP UP AS SOON AS THE LATE MORNING IN THE
CNTRL-NRN PORTIONS OF CWA...AND SPREAD SOUTH OF ALY. WE KEPT THE
HIGHEST CHC TO LIKELY POPS FROM ALY SOUTH AND EAST DURING THE AFTERNOON.
HEAT INDICES/APPARENT TEMPS WILL GET INTO THE MID AND U90S OVER
PORTIONS OF THE MID HUDSON VALLEY...AND LITCHFIELD COUNTY...BUT
THEY SHOULD FALL SHY OF ADVISORY LEVELS WITH THE SHOWERS AND
THUNDERSTORMS MOVING IN. LATEST HIRES WRF HAS THE MOST ROBUST
CONVECTION WITH THE COMPOSITE REF PRODUCT GRAZING SRN DUTCHESS...AND
LITCHFIELD COUNTIES AFTER 21Z...THE LATEST HRRR IS A LITTLE BIT
FURTHER NORTH...BUT STILL SOUTH OF THE CAPITAL REGION...BUT HAS
THE STRONGER CONVECTION IMPACTING THE AREA BTWN 18Z-21Z. DAMAGING
WIND GUSTS WOULD BE THE MAIN THREAT WITH POTENTIAL BOWING SEGMENTS
WITH UNIDIRECTIONAL SHEAR PROFILES ON THE MODEL SOUNDINGS.
MAX TEMPS WILL RANGE FROM THE M80S TO L90S IN THE VALLEYS...WITH
SOME U70S OVER THE NRN MTNS TO LOWER TO MID80S OVER THE HILLS AND
MTNS SOUTH OF ALBANY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT...THE FRONT DIPS SOUTH OF THE FORECAST AREA WITH THE ISOLD-
SCT SHOWER AND THUNDERSTORM ACTIVITY ENDING BY AROUND MIDNIGHT FOR
THE SRN MOST ZONES. THE LOW LEVEL COLD ADVECTION WILL ALLOW H850
TEMPS TO LOWER TO 10 TO 14C FROM THE CAPITAL REGION NORTH AND
WEST...AND 14-17C TO THE SOUTH AND EAST. THE SKIES SHOULD CLEAR
OVERNIGHT...AND LOWS WILL BE IN THE U40S TO M50S NORTH OF
ALY...AND U50S TO L60S SOUTH AND EAST.
THURSDAY...A VERY NICE DAY IS SHAPING UP WITH STRONG SUBSIDENCE
IN WAKE OF THE FRONT...AND A LARGE SFC ANTICYCLONE BUILDING IN
FROM ONTARIO AND JAMES BAY. FEW-SCT FAIR WX CUMULUS WILL BE
AROUND...AND DECENT MIXING WILL ALLOW MAX TEMPS TO BE IN THE LOWER
TO M80S IN THE VALLEYS...AND MAINLY 70S OVER THE HILLS AND MTNS
/SOME U60S TOO/.
THURSDAY NIGHT...H500 UPPER LOW CONTINUES TO LIFT N/NE INTO THE
CANADIAN MARITIMES WITH BROAD SFC HIGH CONTINUING TO RIDGE IN FROM
JAMES BAY. FRONTAL BOUNDARY FROM WED...BECOMES STATIONARY OVER THE
MID ATLANTIC REGION. THE NAM/GFS/ECMWF/CAN GUIDANCE ALL SHOW A
DISTURBANCE MOVING ALONG THE BOUNDARY...WITH SOME THERMAL
ADVECTION SHOWERS GETTING INTO THE MID HUDSON VALLEY. WE PLACED
SOME SLIGHT CHC POPS FOR SHOWERS WELL SOUTH OF THE CAPITAL
REGION...OTHERWISE IT SHOULD BE A COOL AND COMFORTABLE EVENING
WITH LOWS IN THE 50S...EXCEPT FOR SOME 40S OVER THE SRN
DACKS...AND SRN GREENS...AND SOME L60S OVER THE MID HUDSON VALLEY.
FRI-FRI NIGHT...CLOUDS CONTINUE TO SPILL NORTH WITH THE WAVE
RIDING THE FRONTAL BOUNDARY OVER THE MID ATLANTIC REGION. THE SREF
POPS STILL REMAIN LOW IN THE SLIGHT CHC CATEGORY. WEAK THETA-E
ADVECTION AND ISENTROPIC LIFT COULD ALLOW A FEW-SCT SHOWERS SOUTH
OF THE CAPITAL REGION. MAX TEMPS WILL ACTUALLY BE WARMER FROM THE
CAPITAL REGION NORTH...WHERE MORE SUNSHINE MAY OCCUR. THE CLOUDS
AND ISOLD-SCT SHOWERS SHOULD CLEAR FRI NIGHT...AS THE SFC RIDGE
BUILDS BACK IN. TEMPS MAY ACTUALLY RUN A SHADE BELOW NORMAL THIS
DAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE LONG TERM PERIOD IS EXPECTED TO START DRY WITH THE POSSIBILITY
OF SOME UNSETTLED WEATHER LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
TEMPS AND HUMIDITY WILL START TO INCREASE SLOWLY AS THE RIDGE OF
HIGH PRESSURE SLIDES OFF THE EASTERN SEABOARD AND A RETURN FLOW
STARTS TO DEVELOP. DRY WEATHER IS EXPECTED TO CONTINUE THROUGH
SUNDAY MORNING WITH WIDELY SCATTERED TO SCATTERED SHOWERS DEVELOPING
SUNDAY AFTERNOON AND CONTINUING INTO SUNDAY EVENING AS A COLD FRONT
DROPS SOUTHEAST TOWARD THE SAINT LAWRENCE VALLEY. EXPECT A BETTER
CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY EVENING AS
THE COLD FRONT WORKS SOUTHEASTWARD THROUGH THE FA ENDING UP ACROSS
SOUTHEAST NY AND SOUTHERN NEW ENGLAND TUESDAY MORNING.
H8 TEMPS ARE EXPECTED TO RISE FROM +10 TO +11 C SATURDAY MORNING TO
+15 TO +17 C LATE SUNDAY AHEAD OF THE COLD FRONT AND THEN DROP TO
+10 TO +14 C BY LATE TUESDAY IN THE WAKE OF THE COLD FRONT.
EXPECT HIGHS ON SATURDAY TO BE IN THE MID 70S TO LOWER 80S...UPPER
70S TO MID 80S ON SUNDAY AND MONDAY...AND LOWER 70S TO MID 80S ON
TUESDAY. LOWS ARE GENERALLY EXPECTED TO BE IN THE MID 50S TO MID
60S...SATURDAY NIGHT THROUGH MONDAY NIGHT.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
MOST OF THE CONVECTION FOR THE TAF SITES HAS ENDED FOR THE NIGHT
EXCEPT AT KGFL WHERE ONE LAST ROUND OF SHOWERS AND THUNDERSTORMS
IS EXPECTED TO MOVE THROUGH BTWN 06Z AND 08Z. IT WILL CONTINUE TO
REMAIN VERY HUMID OVERNIGHT WITH MAINLY VFR/MVFR CONDITIONS WITH
SOME FOG AND HAZE MAINLY AFTER 08Z. FOR TODAY...EXPECT BEST CHANCE
OF SHOWERS AND THUNDERSTORMS WILL BE ACROSS SOUTHERN AREAS AHEAD
OF THE COLD FRONT WITH CLEARING EXPECTED AT THE TAF SITES DURING
THE EVENING.
LIGHT AND VARIABLE WINDS OVERNIGHT WILL BECOME WEST TO NORTHWEST
TODAY AND THEN EVENTUALLY NORTHWEST TO NORTH AT 5 TO 10 KTS IN THE
WAKE OF THE COLD FRONT. THE EXCEPTION WILL BE AT KPOU WHERE
SOUTHWEST WINDS AT 4-6 KTS THROUGH THIS AFTERNOON WILL BECOME
NORTH AT AROUND 3 KTS EARLY THIS EVENING. WINDS AT ALL THE TAF
SITES WILL THEN BECOME LIGHT AND VARIABLE BY MID TO LATE EVENING.
OUTLOOK...
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTMS.
&&
.FIRE WEATHER...
A COLD FRONT WILL SLOWLY MOVE SOUTHWARD ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND TODAY WITH SOME SHOWERS AND THUNDERSTORMS. A
BROAD AREA OF HIGH PRESSURE WILL BUILD IN FROM JAMES BAY TONIGHT
INTO THURSDAY WITH SEASONABLE TEMPERATURES AND LESS HUMID
CONDITIONS.
RELATIVE HUMIDITY VALUES WILL LOWER TO 40-70 PERCENT TODAY...AND
RECOVER TO 90 TO 100 PERCENT TONIGHT. EXPECT MINIMUM RH VALUES OF
25 TO 50 PERCENT THURSDAY AFTERNOON.
THE WINDS WILL BE FROM THE WEST OR NORTHWEST AT 5 TO 15 MPH
TODAY...AND DECREASE TO LESS THAN 10 MPH TONIGHT. NORTH WINDS OF 5
TO 15 MPH WILL BE COMMON ON THURSDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TODAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A SHORT PERIOD OF
ANOMALOUSLY HIGH PRECIPITATELY WATER VALUES IN THE 1.5 TO 2 INCH
RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR DRAINAGE FLOODING
IS POSSIBLE ESPECIALLY FROM THE CAPITAL REGION SOUTH. ZONAL FLASH FLOOD
GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE POTENTIAL FOR FLASH
FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO SERVICE AREA.
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...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION...RESENT
NWS TAMPA BAY RUSKIN FL
417 AM EDT WED JUL 18 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RUC ANALYSIS CONTINUES TO SHOW OUR REGION
LOCATED WITHIN AN UPPER LEVEL WEAKNESS BETWEEN A RIDGE OF HIGH
PRESSURE OVER THE LOWER/MIDDLE MS VALLEY...AND ANOTHER RIDGE CENTER
OFF THE SOUTHEAST CONUS COAST. THE WEAKNESS IS DOMINATED BY A
STUBBORN TUTT CELL WHICH IS VERY SLOWLY MIGRATING NORTHWARD INTO
SOUTHERN GEORGIA EARLY THIS MORNING. OUR FORECAST AREA (ESPECIALLY
THE NORTHERN ZONES) REMAIN UNDER THE SOUTHERN PERIPHERY OF THIS
CIRCULATION ALONG WITH PERIODIC IMPULSES OF SYNOPTIC SUPPORT FOR
ENHANCED LIFT. THE ATMOSPHERIC COLUMN WITHIN THIS WEAKNESS IS RATHER
MOIST WITH PW VALUES OF 2"+.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS REMAINS ALIGNED OVER THE
SOUTHERN HALF OF THE FL PENINSULA INTO THE SE GULF OF MEXICO. A
FAVORED SW FLOW AROUND THIS RIDGE ALONG WITH SOME ENHANCED SUPPORT
FROM THE UPPER TUTT CELL IS FORCING A SCATTERING OF CONVECTION EARLY
THIS MORNING OVER THE NORTHERN AND CENTRAL COASTAL WATERS. THE
1000-700MB FLOW TO THE NORTH OF TAMPA BAY IS HELPING TO MIGRATE SOME
OF THIS ACTIVITY BACK TOWARD THE NATURE COAST. WILL KEEP SCT SHOWERS
IN THE FORECAST ALONG THE COAST FROM PINELLAS NORTHWARD.
FURTHER SOUTH...THE INFLUENCE OF THE UPPER TUTT IS MUCH LESS. THIS
TIME OF YEAR THE UNSTABLE LOWER LEVELS OVER THE GULF COMBINED WITH
ANY LATE NIGHT OFFSHORE WIND COMPONENT MAY STILL FIRE A FEW STORMS
OVER THE SOUTHERN COASTAL WATERS...HOWEVER A LOW LEVEL FLOW MORE
PARALLEL TO THE COAST SHOULD KEEP MOST OF THIS POTENTIAL ACTIVITY
FROM MIGRATING BACK TO THE BEACHES.
&&
.SHORT TERM (TODAY THROUGH FRIDAY)...
TODAY...UPPER LEVEL WEAKNESS/TUTT CELL IS PROGGED TO OPEN UP AND
CONTINUE TO SLOWLY LIFT NORTH. THIS PROGRESSION WILL ALLOW THE UPPER
RIDGE TO OUR EAST TO BEGIN BUILDING BACK TOWARD THE REGION. OVERALL
WILL SEE A SLOW RISE IN H5 HEIGHTS THROUGH THE DAY...HOWEVER THE
RIDGE AXIS AND ANY SIGNIFICANT SUPPRESSION WILL REMAIN WELL TO OUR
SOUTH. WITH A MOIST COLUMN IN PLACE...WILL EXPECT AT LEAST A CLIMO
DISTRIBUTION OF SHOWERS AND STORMS THROUGH THE DAY. HIGHEST COVERAGE
OF SHOWERS LIKELY TO OCCUR ALONG AND NORTH OF THE I-4 CORRIDOR IN
CLOSER PROXIMITY TO CYCLONIC FLOW/SYNOPTIC SUPPORT ASSOCIATED WITH
THE DEPARTING TUTT. SOUTH OF THE TAMPA BAY AREA ALONG THE
COAST...SHOULD SEE A DECENT SEA-BREEZE CIRCULATION DEVELOP AND HELP
TO PUSH MUCH OF THE DIURNAL CONVECTION INLAND FROM THE BEACHES AFTER
THE MIDDLE AFTERNOON HOURS.
TONIGHT...UPPER LEVEL RIDGING WILL CONTINUE TO BUILD INTO MAINLY THE
CENTRAL AND SOUTHERN PORTIONS OF THE PENINSULA...WITH A DRIER AND
MORE HOSTILE COLUMN FOR DEEP CONVECTION BEGINNING TO ARRIVE FROM THE
SOUTH AND SOUTHEAST. UPPER LEVEL WEAKNESS/TROUGHING WILL BASICALLY
STALL UP OVER THE FL PANHANDLE REGION...AND THEN REMAIN IN POSITION
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD. THIS PATTERN WILL
PUT OUR NORTHERN ZONES (NATURE COAST) IN THE TRANSITION ZONES
BETWEEN THE LESS FAVORABLE CONVECTIVE REGIME TO THE SOUTH AND A VERY
FAVORABLE CONVECTIVE REGIME NORTH AND WEST OF THE SUWANNEE RIVER
VALLEY. WITH THIS IN MIND WILL ONCE AGAIN HIGHLIGHT NOCTURNAL
SHOWERS/STORMS DEVELOPING OVER THE NORTHERN COASTAL WATERS...THEN
MIGRATING BACK TOWARD THE COAST DURING THE LATE NIGHT HOURS. BEST
CHANCES TO SEE THIS LATE NIGHT CONVECTION WILL BE ALONG COASTAL
LEVY/CITRUS COUNTIES.
THURSDAY...UPPER RIDGE AXIS AND ENHANCED SUPPRESSION WILL CONTINUE
OVER THE SOUTHERN HALF OF THE AREA. WILL KEEP THE HIGHEST RAIN
CHANCES (35-50%) ALONG AND NORTH OF THE I-4 CORRIDOR...AND THE
HIGHEST TEMPERATURES (MIDDLE 90S) FURTHER SOUTH. FROM THE TAMPA BAY
AREA AND SOUTHWARD...GOOD CHANCE TO SEE THE SEA-BREEZE CLEAR OUT ANY
WIDELY SCT SHOWERS FROM THE BEACHES BY MID-AFTERNOON.
FRIDAY...LOOKS TO BE THE LEAST ACTIVE DAY OF THE WORK WEEK IN TERMS
OF CONVECTION. WILL HIGHLIGHT A 30% CHANCE FOR WIDELY SCT STORMS
OVER THE FAR NORTHERN ZONES TOWARD THE SUWANNEE RIVER VALLEY...WITH
ONLY ISOLATED 20% SHOWERS FOR THE MAJORITY OF THE AREA. WITH BOTH
THE UPPER AND SURFACE RIDGE AXIS LIFTING NORTH OF THE FORT MYERS
AREA...WOULD NOT BE SURPRISED TO SEE A BIT BETTER CHANCE FOR LATE
DAY STORMS DOWN TOWARD CHARLOTTE/LEE COUNTIES...BUT WILL ONLY
HIGHLIGHT A 30% CHANCE FOR NOW. THE BIGGER STORY FOR FRIDAY WILL BE
THE TEMPERATURES. MANY LOCATIONS AWAY FROM THE BEACHES WILL SEE THE
MERCURY SOAR INTO THE MIDDLE 90S...WITH NORMALLY HOTTER LOCATIONS OF
HARDEE/DE SOTO/HIGHLANDS COUNTIES REACHING THE UPPER 90S.
&&
.LONG TERM (SATURDAY THROUGH NEXT WEDNESDAY)...
OVERALL THE GLOBAL MODELS HAVE NOT CHANGED MUCH. A STRONG
SUB-TROPICAL RIDGE WILL STRETCH WESTWARD FROM THE ATLANTIC TO
CENTRAL FLORIDA THROUGH THE PERIOD. THE DRIER AIR WILL BE RETREATING
NORTHWARD FRIDAY NIGHT WITH HIGHER PRECIPITABLE WATERS RETURNING
FROM SOUTH TO NORTH ON SATURDAY. ONCE AGAIN MEX POPS ARE QUITE
LOW...SO WILL CONTINUE TO JUST SHOW A SLIGHT CHANCE OF AFTERNOON
STORMS ON SATURDAY.
ON SUNDAY...PRECIPITABLE WATERS RISE TO WELL OVER 2 INCHES FOLLOWING
A THE PASSAGE OF A WEAK TROPICAL WAVE. THIS SHOULD ALLOW RAIN
CHANCES TO RETURN TO NORMAL WITH 40 TO 50 PERCENT CHANCES DURING THE
AFTERNOON HOURS.
DRY AIR BEGINS TO MOVE BACK IN FROM THE SOUTH ON MONDAY WITH RAIN
CHANCES DECREASING TO ONLY 20 TO 30 PERCENT AGAIN BY TUESDAY.
IT WILL BE QUITE HOT ON SATURDAY WITH WIDESPREAD MID 90S LIKELY AWAY
FROM THE COAST. ADDITIONAL CLOUD COVER AND SHOWER ACTIVITY WILL KEEP
IT A COUPLE OF DEGREES COOLER ON SUNDAY...THEN THE MID 90S RETURN
AGAIN WITH THE DRIER AIR IN PLACE BY TUESDAY.
&&
.AVIATION...
MAINLY VFR CONDITIONS EXPECTED THROUGH MID-MORNING WEDNESDAY WITH
SOME MVFR OR IFR CONDITIONS POSSIBLE 15Z TO 00Z AS SHOWERS AND
THUNDERSTORMS REDEVELOP WITH HEATING. COVERAGE AND TIMING OF SHOWERS
STILL NOT CERTAIN SO WILL HANDLE WITH VCTS AT THIS TIME.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL REMAIN ALIGNED OVER THE SOUTHERN AND
CENTRAL WATERS THROUGH THE NEXT SEVERAL DAYS. THIS POSITION WILL
KEEP WINDS AND SEAS BELOW HEADLINE CRITERIA INTO THE UPCOMING
WEEKEND. THE BEST CHANCES FOR SCATTERED SHOWERS AND STORMS OVER THE
COASTAL WATERS WILL BE FROM TAMPA BAY NORTHWARD ALONG THE NATURE
COAST.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ANTICIPATED THROUGH FRIDAY.
ALTHOUGH TEMPERATURES WILL BE INCREASING EACH AFTERNOON FOR THE NEXT
SEVERAL DAYS...RELATIVE HUMIDITY LEVELS ARE STILL FORECAST TO
GENERALLY REMAIN ABOVE CRITICAL VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 77 92 78 / 50 20 20 10
FMY 91 76 93 76 / 30 20 20 10
GIF 91 76 95 75 / 50 30 40 20
SRQ 89 76 91 76 / 50 20 20 10
BKV 90 72 93 73 / 60 20 30 10
SPG 88 78 91 80 / 50 20 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION/LONG TERM...JILLSON
AREA FORECAST DISCUSSION...RESENT
NWS TAMPA BAY RUSKIN FL
340 AM EDT WED JUL 18 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RUC ANALYSIS CONTINUES TO SHOW OUR REGION
LOCATED WITHIN AN UPPER LEVEL WEAKNESS BETWEEN A RIDGE OF HIGH
PRESSURE OVER THE LOWER/MIDDLE MS VALLEY...AND ANOTHER RIDGE CENTER
OFF THE SOUTHEAST CONUS COAST. THE WEAKNESS IS DOMINATED BY A
STUBBORN TUTT CELL WHICH IS VERY SLOWLY MIGRATING NORTHWARD INTO
SOUTHERN GEORGIA EARLY THIS MORNING. OUR FORECAST AREA (ESPECIALLY
THE NORTHERN ZONES) REMAIN UNDER THE SOUTHERN PERIPHERY OF THIS
CIRCULATION ALONG WITH PERIODIC IMPULSES OF SYNOPTIC SUPPORT FOR
ENHANCED LIFT. THE ATMOSPHERIC COLUMN WITHIN THIS WEAKNESS IS RATHER
MOIST WITH PW VALUES OF 2"+.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS REMAINS ALIGNED OVER THE
SOUTHERN HALF OF THE FL PENINSULA INTO THE SE GULF OF MEXICO. A
FAVORED SW FLOW AROUND THIS RIDGE ALONG WITH SOME ENHANCED SUPPORT
FROM THE UPPER TUTT CELL IS FORCING A SCATTERING OF CONVECTION EARLY
THIS MORNING OVER THE NORTHERN AND CENTRAL COASTAL WATERS. THE
1000-700MB FLOW TO THE NORTH OF TAMPA BAY IS HELPING TO MIGRATE SOME
OF THIS ACTIVITY BACK TOWARD THE NATURE COAST. WILL KEEP SCT SHOWERS
IN THE FORECAST ALONG THE COAST FROM PINELLAS NORTHWARD.
FURTHER SOUTH...THE INFLUENCE OF THE UPPER TUTT IS MUCH LESS. THIS
TIME OF YEAR THE UNSTABLE LOWER LEVELS OVER THE GULF COMBINED WITH
ANY LATE NIGHT OFFSHORE WIND COMPONENT MAY STILL FIRE A FEW STORMS
OVER THE SOUTHERN COASTAL WATERS...HOWEVER A LOW LEVEL FLOW MORE
PARALLEL TO THE COAST SHOULD KEEP MOST OF THIS POTENTIAL ACTIVITY
FROM MIGRATING BACK TO THE BEACHES.
&&
.SHORT TERM (TODAY THROUGH FRIDAY)...
TODAY...UPPER LEVEL WEAKNESS/TUTT CELL IS PROGGED TO OPEN UP AND
CONTINUE TO SLOWLY LIFT NORTH. THIS PROGRESSION WILL ALLOW THE UPPER
RIDGE TO OUR EAST TO BEGIN BUILDING BACK TOWARD THE REGION. OVERALL
WILL SEE A SLOW RISE IN H5 HEIGHTS THROUGH THE DAY...HOWEVER THE
RIDGE AXIS AND ANY SIGNIFICANT SUPPRESSION WILL REMAIN WELL TO OUR
SOUTH. WITH A MOIST COLUMN IN PLACE...WILL EXPECT AT LEAST A CLIMO
DISTRIBUTION OF SHOWERS AND STORMS THROUGH THE DAY. HIGHEST COVERAGE
OF SHOWERS LIKELY TO OCCUR ALONG AND NORTH OF THE I-4 CORRIDOR IN
CLOSER PROXIMITY TO CYCLONIC FLOW/SYNOPTIC SUPPORT ASSOCIATED WITH
THE DEPARTING TUTT. SOUTH OF THE TAMPA BAY AREA ALONG THE
COAST...SHOULD SEE A DECENT SEA-BREEZE CIRCULATION DEVELOP AND HELP
TO PUSH MUCH OF THE DIURNAL CONVECTION INLAND FROM THE BEACHES AFTER
THE MIDDLE AFTERNOON HOURS.
TONIGHT...UPPER LEVEL RIDGING WILL CONTINUE TO BUILD INTO MAINLY THE
CENTRAL AND SOUTHERN PORTIONS OF THE PENINSULA...WITH A DRIER AND
MORE HOSTILE COLUMN FOR DEEP CONVECTION BEGINNING TO ARRIVE FROM THE
SOUTH AND SOUTHEAST. UPPER LEVEL WEAKNESS/TROUGHING WILL BASICALLY
STALL UP OVER THE FL PANHANDLE REGION...AND THEN REMAIN IN POSITION
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD. THIS PATTERN WILL
PUT OUR NORTHERN ZONES (NATURE COAST) IN THE TRANSITION ZONES
BETWEEN THE LESS FAVORABLE CONVECTIVE REGIME TO THE SOUTH AND A VERY
FAVORABLE CONVECTIVE REGIME NORTH AND WEST OF THE SUWANNEE RIVER
VALLEY. WITH THIS IN MIND WILL ONCE AGAIN HIGHLIGHT NOCTURNAL
SHOWERS/STORMS DEVELOPING OVER THE NORTHERN COASTAL WATERS...THEN
MIGRATING BACK TOWARD THE COAST DURING THE LATE NIGHT HOURS. BEST
CHANCES TO SEE THIS LATE NIGHT CONVECTION WILL BE ALONG COASTAL
LEVY/CITRUS COUNTIES.
THURSDAY...UPPER RIDGE AXIS AND ENHANCED SUPPRESSION WILL CONTINUE
OVER THE SOUTHERN HALF OF THE AREA. WILL KEEP THE HIGHEST RAIN
CHANCES (35-50%) ALONG AND NORTH OF THE I-4 CORRIDOR...AND THE
HIGHEST TEMPERATURES (MIDDLE 90S) FURTHER SOUTH. FROM THE TAMPA BAY
AREA AND SOUTHWARD...GOOD CHANCE TO SEE THE SEA-BREEZE CLEAR OUT ANY
WIDELY SCT SHOWERS FROM THE BEACHES BY MID-AFTERNOON.
FRIDAY...LOOKS TO BE THE LEAST ACTIVE DAY OF THE WORK WEEK IN TERMS
OF CONVECTION. WILL HIGHLIGHT A 30% CHANCE FOR WIDELY SCT STORMS
OVER THE FAR NORTHERN ZONES TOWARD THE SUWANNEE RIVER VALLEY...WITH
ONLY ISOLATED 20% SHOWERS FOR THE MAJORITY OF THE AREA. WITH BOTH
THE UPPER AND SURFACE RIDGE AXIS LIFTING NORTH OF THE FORT MYERS
AREA...WOULD NOT BE SURPRISED TO SEE A BIT BETTER CHANCE FOR LATE
DAY STORMS DOWN TOWARD CHARLOTTE/LEE COUNTIES...BUT WILL ONLY
HIGHLIGHT A 30% CHANCE FOR NOW. THE BIGGER STORY FOR FRIDAY WILL BE
THE TEMPERATURES. MANY LOCATIONS AWAY FROM THE BEACHES WILL SEE THE
MERCURY SOAR INTO THE MIDDLE 90S...WITH NORMALLY HOTTER LOCATIONS OF
HARDEE/DE SOTO/HIGHLANDS COUNTIES REACHING THE UPPER 90S.
&&
.LONG TERM (SATURDAY THROUGH NEXT WEDNESDAY)...
OVERALL THE GLOBAL MODELS HAVE NOT CHANGED MUCH. A STRONG
SUB-TROPICAL RIDGE WILL STRETCH WESTWARD FROM THE ATLANTIC TO
CENTRAL FLORIDA THROUGH THE PERIOD. THE DRIER AIR WILL BE RETREATING
NORTHWARD FRIDAY NIGHT WITH HIGHER PRECIPITABLE WATERS RETURNING
FROM SOUTH TO NORTH ON SATURDAY. ONCE AGAIN MEX POPS ARE QUITE
LOW...SO WILL CONTINUE TO JUST SHOW A SLIGHT CHANCE OF AFTERNOON
STORMS ON SATURDAY.
ON SUNDAY...PRECIPITABLE WATERS RISE TO WELL OVER 2 INCHES FOLLOWING
A THE PASSAGE OF A WEAK TROPICAL WAVE. THIS SHOULD ALLOW RAIN
CHANCES TO RETURN TO NORMAL WITH 40 TO 50 PERCENT CHANCES DURING THE
AFTERNOON HOURS.
DRY AIR BEGINS TO MOVE BACK IN FROM THE SOUTH ON MONDAY WITH RAIN
CHANCES DECREASING TO ONLY 20 TO 30 PERCENT AGAIN BY TUESDAY.
IT WILL BE QUITE HOT ON SATURDAY WITH WIDESPREAD MID 90S LIKELY AWAY
FROM THE COAST. ADDITIONAL CLOUD COVER AND SHOWER ACTIVITY WILL KEEP
IT A COUPLE OF DEGREES COOLER ON SUNDAY...THEN THE MID 90S RETURN
AGAIN WITH THE DRIER AIR IN PLACE BY TUESDAY.
&&
.AVIATION...
MAINLY VFR CONDITIONS EXPECTED THROUGH MID-MORNING WEDNESDAY WITH
SOME MVFR OR IFR CONDITIONS POSSIBLE 15Z TO 00Z AS SHOWERS AND
THUNDERSTORMS REDEVELOP WITH HEATING. COVERAGE AND TIMING OF SHOWERS
STILL NOT CERTAIN SO WILL HANDLE WITH VCTS AT THIS TIME.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL REMAIN ALIGNED OVER THE SOUTHERN AND
CENTRAL WATERS THROUGH THE NEXT SEVERAL DAYS. THIS POSITION WILL
KEEP WINDS AND SEAS BELOW HEADLINE CRITERIA INTO THE UPCOMING
WEEKEND. THE BEST CHANCES FOR SCATTERED SHOWERS AND STORMS OVER THE
COASTAL WATERS WILL BE FROM TAMPA BAY NORTHWARD ALONG THE NATURE
COAST.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ANTICIPATED THROUGH FRIDAY.
ALTHOUGH TEMPERATURES WILL BE INCREASING EACH AFTERNOON FOR THE NEXT
SEVERAL DAYS...RELATIVE HUMIDITY LEVELS ARE STILL FORECAST TO
GENERALLY REMAIN ABOVE CRITICAL VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 77 92 78 / 50 20 20 10
FMY 91 76 93 76 / 30 20 20 10
GIF 91 76 95 75 / 50 30 40 20
SRQ 89 76 91 76 / 50 20 20 10
BKV 90 72 93 73 / 60 20 30 10
SPG 88 78 91 80 / 50 20 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION/LONG TERM...JILLSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
125 AM EDT WED JUL 18 2012
.UPDATE...
/ISSUED AT 1035 PM EDT TUE JUL 17 2012/
HAVE LEFT SLIGHT CHANCE POPS ACROSS THE CWA FOR THE REMAINDER OF THE
NIGHT...EXCEPT CHANCE FOR AREAS NORTH OF ATLANTA TO ATHENS. SOME
CONVECTION DEVELOPING NEAR CHATTANOOGA AND DRIFTING SOUTH. RAIN
COOLED AIR HAS REACHED THE FORECAST MIN TEMPERATURES IN A FEW AREAS.
SO HAVE LOWERED THE OVERNIGHT MINS A BIT. OTHERWISE NO CHANGES.
41
&&
.PREVIOUS...
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 408 PM EDT TUE JUL 17 2012/
PRIMARY CONCERN IS COVERAGE OF TSRA THIS AFTERNOON AND EVOLUTION
THIS EVENING. SO FAR TODAY...CONVECTION CLOSELY FOLLOWING MORNING
HRRR RUNS WITH ONE COMPLEX MOVING THROUGH EAST AND NOW SOUTHERN
PARTS OF ATL METRO. OTHER SCT STORMS ACROSS WESTCENTRAL AND FAR NE
GA. HRRR DID PROG ABUNDANT CONVECTION OVER NW GA TO NRN AL ALONG
CUMBERLAND PLATEAU AFTER 21Z WHICH IS NOT PANNING OUT SO FAR.
EXPECT TSRA TO CONTINUE TO PUSH SLOWLY SSW. HEAVY RAIN HAS BEEN
OCCURRING BUT FORTUNATELY...NO ONE AREA IS APPROACHING FFG.
EXPECTION TSRA TO WEAKEN SOME AFTER 6PM AND DISSIPATE BY 9PM.
UPPER LOW OVER NRN FL CONTINUES TO BE PRIMARY FEATURE. THIS LOW
PROGGED BY ALL MODELS TO DRIFT NORTH TONIGHT AND TOMORROW AS IT
GETS PICKED UP BY WEAK WESTERLIES WHICH DRIFT INTO THE MID
ATLANTIC WED. IMPACT FOR CWA IS HIGH MEAN RH AND CONTINUED DIURNAL
CONVECTION WITH NO PREFERENCE FOR ANY ONE LOCATION. CHC POPS
APPEAR MOST APPROPRIATE. ISOLD SVR STORMS AGAIN LIKELY. IF WE GET
MORE CLOUDS OR MORNING PRECIP WED...WILL SEE LESS THAN TODAY.
HAVE TWEAKED MAX TEMP GUIDANCE UP A LITTLE BASED ON RECENT TRENDS
AND MORE ISOLATED AFTERNOON CONVECTION THAN MODELS DEPICTING.
GUIDANCE BLEND WORKING WELL WITH SLIGHT UPWARD ADJUSTMENT FOR MIN
TEMPS.
SNELSON
.LONG TERM /THURSDAY THROUGH TUESDAY/...
/ISSUED AT 408 PM EDT TUE JUL 17 2012/
MINOR DISCREPANCIES IN MODEL SOLUTIONS FOR THE LONG TERM BUT OVERALL
DECENT GENERAL CONSENSUS. GFS HAS GREATER AMOUNTS OF MOISTURE THAN
THE ECMWF FOR MUCH OF THE FORECAST PERIOD AND SLIGHT DIFFERENCES IN
LOCATION OF THE SFC FRONT PROGGED TO DIP SOUTHWARD INTO THE AREA FOR
THE WEEKEND. DUE TO UNCERTAINTY WITH LOCATION OF THIS BOUNDARY THIS
LATE IN THE FORECAST PERIOD... HAVE MAINTAINED CURRENT FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
BAKER
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
&&
.AVIATION...
06Z UPDATE...
CONVECTION OVER NORTHWEST GA SHOULD REMAIN NORTHWEST OF THE ATL AREA
TAFS AND WILL NOT POSE A THREAT. PRETTY MUCH A PERSISTENCE FORECAST
WITH VFR CONDITIONS EXCEPT IN AFTERNOON THUNDERSTORMS THAT COULD
LINGER INTO THE EVENING. EXPECT ABOUT THE SAME AMOUNT OF COVERAGE AS
YESTERDAY AND WILL THEREFORE GO WITH PREDOMINANT TSRA FROM 18Z TO
22Z. THERE COULD BE SOME MORNING STRATUS AND WILL MAINTAIN THE
MENTION OF 5SM SCT015 EARLY THIS MORNING.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON FORMATION OF MORNING STRATUS AND OF TIMING OF CONVECTION.
HIGH ON ALL OTHER ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 95 71 94 / 20 40 30 40
ATLANTA 74 92 73 91 / 20 50 30 40
BLAIRSVILLE 67 88 68 87 / 20 40 30 50
CARTERSVILLE 69 93 70 92 / 20 50 30 50
COLUMBUS 75 94 73 92 / 30 50 40 50
GAINESVILLE 72 93 72 91 / 20 40 30 50
MACON 73 94 72 93 / 30 50 30 40
ROME 70 94 71 92 / 20 50 30 50
PEACHTREE CITY 70 93 70 91 / 20 50 40 40
VIDALIA 74 94 74 95 / 30 50 40 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...41
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
433 AM CDT WED JUL 18 2012
.DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEW POINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.CLIMATE...
305 PM CDT...
RECORDS FOR TODAY JULY 17TH ARE AS FOLLOWS:
CHICAGO RECORD HIGH: 100 /1942/
ROCKFORD RECORD HIGH: 104 /1936/
CHICAGO RECORD WARM LOW: 80 /1878/
ROCKFORD RECORD WARM LOW: 76 /1982/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
TIMING OF ARRIVAL COLD FRONTAL PASSAGE ACROSS TERMINALS.
POTENTIAL FOR CONVECTIVE ACTIVITY ALONG AND AHEAD OF COLD FRONT
TODAY AS WELL AS ELEVATED CONVECTION POST FRONTAL DURING THE
OVERNIGHT.
TRS
//DISCUSSION...UPDATED 06Z...
KLOT...TORD AND TMDW RADARS SHOWED THE OUTFLOW BOUNDARY THAT
ORIGINATED FROM THUNDERSTORMS OVER E CENTRAL WI AND CENTRAL LAKE
MI CONTINUED TO DROP S DURING THE EVENING FROM NORTHEASTERN TO
SOUTHEASTERN COOK CO. BURNHAM HARBOR AND MDW BRIEFLY SHOWING
LIGHT N-NNE WINDS 04-05Z BUT HAVE ALREADY SWITCHED BACK TO A
LIGHT SW FLOW.
COLD FRONT AT 05Z WAS LOCATED E-W ACROSS SOUTHERN LOWER MI AND
SOUTHERN LAKE MI TO FAR SOUTHEASTERN WI THEN CURVED WNW TO
SOUTHERN MN. MAIN AREA OF CONVECTION WAS FROM E CENTRAL WI ESE
ACROSS LAKE MI TO W CENTRAL LOWER MI. THIS WAS POST FRONTAL WHERE
ELEVATED CAPE STILL IN PLACE AS A SHORT WAVE MOVED ESE FROM MN
ACROSS CENTRAL WI DURING TUE AFTERNOON AND EVENING.
LATEST MODEL RUNS HAVE THE COLD FRONT SINKING S ACROSS THE STATE
LINE DURING THE OVERNIGHT AND EARLY MORNING...AND PUSHING ACROSS
THE CHI AREA TERMINALS AROUND 13Z. WITH ONLY A HOUR OR TWO OF
HEATING BEFORE THE ARRIVAL AND A LACK OF MID OR UPPER LEVEL
SUPPORT TO NOT SEE ANY SIGNIFICANT POTENTIAL FOR CONVECTIVE
DEVELOPMENT BEFORE THE FRONT PASSES BY THE TERMINALS.
UPSTREAM...A FEW SHORT NARROW LINE SEGMENTS OF SHOWERS AND
THUNDERSTORMS WERE OCCURRING FROM W CENTRAL WI ACROSS CENTRAL MN
TO NW SD. THE SE WERE OCCURRING ALONG THE LEADING EDGE OF THE
TIGHT 850HPA THERMAL GRADIENT. THIS THERMAL GRADIENT DOES MIGRATE
SOUTHWARD TODAY BUT MODELS SHOW IT TO MOVING INTO FAR NE IL TIL
THIS AFTERNOON. CANNOT TOTALLY RULE OUT AN ISOLATED OR WIDELY
SCATTERED THUNDERSTORMS ASSOCIATED WITH THIS BAROCLINIC ZONE
DURING THE AFTERNOON AT OR IN THE VC OF THE CHI TERMINALS BUT
LOCATIONS ALONG THE COLD FRONT LOOK TO BE BETTER CANDIDATES FOR
SEEING SIGNIFICANT CONVECTION LATER TODAY WHERE LOW LEVEL DEW
POINT POOLING AND CONVERGENCE MAXIMIZE CAPE VALUES FROM SE TO S
TO SW AND W OF THE CHI AREA.
FURTHER UP STEAM...MORE SHOWERS AND THUNDERSTORMS WERE OCCURRING
IN CENTRAL SD AS A MORE WELL DEFINED SHORT WAVE TROUGH WAS MOVING
E FROM WESTERN SD AND NEB. THE SHORT WAVE TROUGH AXIS IS PROGGED
TO REACH W CENTRAL WI...SE MN AND EASTERN IA BY 00Z AND TO DROP
ESE ACROSS SOUTHERN WI AS WELL AND NORTHERN AND W CENTRAL
OVERNIGHT. THIS WILL BRING A CHANCE OF SHOWERS AND THUNDERSHOWERS
TO THE LOCAL TERMINALS DURING THE LATE NIGHT AND EARLY MORNING
HOURS OF THU.
WITH THE COLD FRONT SLIPPING S OF THE TERMINALS DURING THE FIRST
PART OF TODAY AND THE SOUTHERN PORTION OF A LARGE RIDGE OF HIGH
PRESSURE BUILDING SE OVER THE UPPER GREAT LAKES LOCAL WINDS
EXPECTED TO BE OUT OF THE NE THOUGH GENERALLY AOB 10KT AS
GRADIENT BEHIND THE FRONT IS SHOWN TO BE PRETTY WEAK.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
HIGH CONFIDENCE IN FORECAST WIND TRENDS.
MODERATE CONFIDENCE IS CONVECTIVE ACTIVITY TO NOT AFFECT
IMMEDIATE CHI VC TODAY.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHC TSRA...ELSE VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHC TSRA...ELSE VFR.
BMD
&&
.MARINE...
432 AM CDT
A COLD FRONT TRAILS FROM LOW PRESSURE OVER THE GULF OF ST.
LAWRENCE ACROSS SOUTHERN LOWER MI...FAR SOUTHERN LAKE MI AND FAR
NORTHERN IL EARLY THIS MORNING. THE COLD FRONT WILL CONTINUE TO
MOVE SLOWLY SOUTHWARD TODAY AND TONIGHT...EXTENDING FROM CENTRAL
IN ACROSS IL TO CENTRAL IA BY THURSDAY MORNING. HIGH PRESSURE OF
WILL BUILD SE FROM HUDSON BAY AND ONTARIO BEHIND THE COLD
FRONT...SPREADING ACROSS THE GREAT LAKES TODAY AND TONIGHT. LOW
PRESSURE WILL RIDE ALONG THE FRONTAL BOUNDARY FROM IA TO THE
UPPER OH VALLEY DURING THU WHILE A RIDGE OF HIGH PRESSURE REMAINS
OVER THE GREAT LAKES. LOW PRESSURE WILL BE TRACKING E FROM CENTRAL
CANADA TO HUDSON BAY THU NIGHT THROUGH FRI NIGHT WHILE THE RIDGE
OVER THE GREAT LAKES SHIFTS S OVER THE NORTHEASTERN U.S. AND THE
MIDWEST. THE COLD FRONT TRAILING FROM THE CANADIAN LOW WILL DROP S
ACROSS NORTHERN LAKE MI SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
323 AM CDT WED JUL 18 2012
.DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEWPOINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.CLIMATE...
305 PM CDT...
RECORDS FOR TODAY JULY 17TH ARE AS FOLLOWS:
CHICAGO RECORD HIGH: 100 /1942/
ROCKFORD RECORD HIGH: 104 /1936/
CHICAGO RECORD WARM LOW: 80 /1878/
ROCKFORD RECORD WARM LOW: 76 /1982/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
TIMING OF ARRIVAL COLD FRONTAL PASSAGE ACROSS TERMINALS.
POTENTIAL FOR CONVECTIVE ACTIVITY ALONG AND AHEAD OF COLD FRONT
TODAY AS WELL AS ELEVATED CONVECTION POST FRONTAL DURING THE
OVERNIGHT.
TRS
//DISCUSSION...UPDATED 06Z...
KLOT...TORD AND TMDW RADARS SHOWED THE OUTFLOW BOUNDARY THAT
ORIGINATED FROM THUNDERSTORMS OVER E CENTRAL WI AND CENTRAL LAKE
MI CONTINUED TO DROP S DURING THE EVENING FROM NORTHEASTERN TO
SOUTHEASTERN COOK CO. BURNHAM HARBOR AND MDW BRIEFLY SHOWING
LIGHT N-NNE WINDS 04-05Z BUT HAVE ALREADY SWITCHED BACK TO A
LIGHT SW FLOW.
COLD FRONT AT 05Z WAS LOCATED E-W ACROSS SOUTHERN LOWER MI AND
SOUTHERN LAKE MI TO FAR SOUTHEASTERN WI THEN CURVED WNW TO
SOUTHERN MN. MAIN AREA OF CONVECTION WAS FROM E CENTRAL WI ESE
ACROSS LAKE MI TO W CENTRAL LOWER MI. THIS WAS POST FRONTAL WHERE
ELEVATED CAPE STILL IN PLACE AS A SHORT WAVE MOVED ESE FROM MN
ACROSS CENTRAL WI DURING TUE AFTERNOON AND EVENING.
LATEST MODEL RUNS HAVE THE COLD FRONT SINKING S ACROSS THE STATE
LINE DURING THE OVERNIGHT AND EARLY MORNING...AND PUSHING ACROSS
THE CHI AREA TERMINALS AROUND 13Z. WITH ONLY A HOUR OR TWO OF
HEATING BEFORE THE ARRIVAL AND A LACK OF MID OR UPPER LEVEL
SUPPORT TO NOT SEE ANY SIGNIFICANT POTENTIAL FOR CONVECTIVE
DEVELOPMENT BEFORE THE FRONT PASSES BY THE TERMINALS.
UPSTREAM...A FEW SHORT NARROW LINE SEGMENTS OF SHOWERS AND
THUNDERSTORMS WERE OCCURRING FROM W CENTRAL WI ACROSS CENTRAL MN
TO NW SD. THE SE WERE OCCURRING ALONG THE LEADING EDGE OF THE
TIGHT 850HPA THERMAL GRADIENT. THIS THERMAL GRADIENT DOES MIGRATE
SOUTHWARD TODAY BUT MODELS SHOW IT TO MOVING INTO FAR NE IL TIL
THIS AFTERNOON. CANNOT TOTALLY RULE OUT AN ISOLATED OR WIDELY
SCATTERED THUNDERSTORMS ASSOCIATED WITH THIS BAROCLINIC ZONE
DURING THE AFTERNOON AT OR IN THE VC OF THE CHI TERMINALS BUT
LOCATIONS ALONG THE COLD FRONT LOOK TO BE BETTER CANDIDATES FOR
SEEING SIGNIFICANT CONVECTION LATER TODAY WHERE LOW LEVEL DEW
POINT POOLING AND CONVERGENCE MAXIMIZE CAPE VALUES FROM SE TO S
TO SW AND W OF THE CHI AREA.
FURTHER UP STEAM...MORE SHOWERS AND THUNDERSTORMS WERE OCCURRING
IN CENTRAL SD AS A MORE WELL DEFINED SHORT WAVE TROUGH WAS MOVING
E FROM WESTERN SD AND NEB. THE SHORT WAVE TROUGH AXIS IS PROGGED
TO REACH W CENTRAL WI...SE MN AND EASTERN IA BY 00Z AND TO DROP
ESE ACROSS SOUTHERN WI AS WELL AND NORTHERN AND W CENTRAL
OVERNIGHT. THIS WILL BRING A CHANCE OF SHOWERS AND THUNDERSHOWERS
TO THE LOCAL TERMINALS DURING THE LATE NIGHT AND EARLY MORNING
HOURS OF THU.
WITH THE COLD FRONT SLIPPING S OF THE TERMINALS DURING THE FIRST
PART OF TODAY AND THE SOUTHERN PORTION OF A LARGE RIDGE OF HIGH
PRESSURE BUILDING SE OVER THE UPPER GREAT LAKES LOCAL WINDS
EXPECTED TO BE OUT OF THE NE THOUGH GENERALLY AOB 10KT AS
GRADIENT BEHIND THE FRONT IS SHOWN TO BE PRETTY WEAK.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
HIGH CONFIDENCE IN FORECAST WIND TRENDS.
MODERATE CONFIDENCE IS CONVECTIVE ACTIVITY TO NOT AFFECT
IMMEDIATE CHI VC TODAY.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHC TSRA...ELSE VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHC TSRA...ELSE VFR.
BMD
&&
.MARINE...
354 PM CDT
THE PRIMARY MARINE CONCERN IS FOR RELATIVELY STRONG NORTH AND
NORTHEAST WINDS OVER THE LAKE AFTER A COOL FRONT PUSHES SOUTH OF
THE LAKE TONIGHT. WITH A MARGINALLY COOLER AIR MASS MOVING OVER
THE VERY WARM LAKE WATERS...COULD SEE SOME GUSTS IN THE 20 TO 25
KT RANGE FROM LATE TONIGHT THROUGH WEDNESDAY NIGHT...ESPECIALLY
FOR THE CENTRAL AND SOUTHERN PORTION OF THE LAKE. THIS WILL ALLOW
FOR WAVES TO BUILD TO THE 3 TO 7 FT RANGE WHERE THE STRONGEST
WINDS OCCUR. HIGH PRESSURE BUILDING OVER THE LAKES REGION THURSDAY
WILL BRING ANOTHER DAY OF MODEST...UP TO 20 KT EAST TO NORTHEAST
FLOW. THEN PRIMARILY LIGHTER WINDS CAN BE EXPECTED FRIDAY AND
SATURDAY WITH THE HIGH OVERHEAD. LATER SATURDAY AND SUNDAY...THE
HIGH PRESSURE WILL SLIDE EAST...BRINGING SOUTH AND SOUTHWEST
WINDS.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
344 AM CDT WED JUL 18 2012
...UPDATED FOR LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1211 AM CDT WED JUL 18 2012
A -17C 500MB LOW WAS LOCATED OVER NORTHERN CALIFORNIA AS OF 00Z
WEDNESDAY. STRONGEST 250MB WINDS AROUND THIS UPPER LOW EXTENDED FROM
THE BASE OF THIS UPPER LOW NORTHEASTWARD INTO EASTERN
OREGON/SOUTHWEST IDAHO. AN UPPER LEVEL RIDGE EXTENDED FROM NORTHERN
NEW MEXICO INTO EASTERN WYOMING AT 00Z WEDNESDAY WITH THE CENTER
OF THIS ANTICYCLONIC FLOW APPEARING TO BE LOCATED OVER SOUTHERN
COLORADO BASED ON 500MB ANALYSIS. A TROUGH OF LOW PRESSURE AT THE
SURFACE AT 01Z EXTENDED FROM NORTH CENTRAL KANSAS INTO SOUTHEAST
COLORADO. THE LATEST RADAR LOOP, AS OF 05Z, INDICATED THAT SEVERAL
OUTFLOW BOUNDARIES FROM THE CONVECTION THAT DEVELOPED EARLIER THIS
EVENING NEAR THIS BOUNDARY WERE NOW LOCATED ACROSS WESTERN AND
NORTH CENTRAL KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 226 AM CDT WED JUL 18 2012
CLOUDS INCREASING IN AREAL COVERAGE EARLY THIS MORNING NEAR A
500MB DEFORMATION ZONE/COL BASED ON 00Z ANALYSIS. ALL THE MODELS
PICK UP ON THIS FEATHER AND INCREASE 700MB RELATIVE HUMIDITY
VALUES EARLY THIS MORNING. THE HRRR EVEN SUGGESTS SOME LIGHT
PRECIPITATION WILL BE POSSIBLE. BASED ON LATEST RADAR TRENDS WILL
FOLLOW THE HRRR AND INTRODUCE SOME LIGHT PRECIPITATION EARLY THIS
MORNING IN SOUTH CENTRAL KANSAS.
AN UPPER LEVEL RIDGE WILL THEN BUILD ACROSS THE CENTRAL AND
NORTHERN ROCKIES LATER TODAY AS THE CENTER OF THIS HIGH, LOCATED
OVER COLORADO, MOVES VERY LITTLE. MODELS REMAIN IN GOOD AGREEMENT
IN MOVING A SURFACE BOUNDARY ACROSS WESTERN KANSAS DURING THE EARLY
MORNING HOURS AND BY THE EARLY AFTERNOON THIS BOUNDARY IS EXPECTED
TO EXTEND FROM HAYS TO GARDEN CITY TO NEAR ELKHART. FORECAST MODEL
SOUNDINGS NEAR THIS SURFACE TROUGH INDICATED SOME MID LEVEL
INSTABILITY AND MOISTURE IN THE 700-600MB LEVEL WILL BE PRESENT AS
AN UPPER LEVEL DISTURBANCE ROTATES AROUND THE UPPER HIGH AND
CROSSES INTO WESTERN KANSAS. GIVEN THE ESTIMATED TIMING OF THIS
UPPER LEVEL DISTURBANCE ALONG WITH WHERE THE BETTER THE LATE DAY
INSTABILITY IS EXPECTED WILL INCREASE THE PRECIPITATION CHANCES
NEAR THE SURFACE BOUNDARY LATE THIS AFTERNOON...ESPECIALLY IN
NORTH CENTRAL KANSAS. THE INVERTED V TYPE OF SOUNDINGS CONTINUE TO
SUGGEST THE PREVIOUS SHIFT HAD THE RIGHT IDEA WITH THE PRIMARY
HAZARD BEING WINDS GUSTY UP TO 45 MPH AND CLOUD TO GROUND
LIGHTNING.
CLOUD COVER THIS AFTERNOON WILL PLAY AN IMPORTANT ROLE ON
TEMPERATURES TODAY. MIXING DOWN THE NAM AND ECMWF 850MB
TEMPERATURES AT 00Z THURSDAY SUGGESTS HIGHS WILL BE MAINLY IN THE
100 TO 104 DEGREE RANGE. INCREASING AFTERNOON CLOUDS AHEAD OF THE
UPPER LEVEL DISTURBANCE HOWEVER MAY RESULT IN KEEPING TEMPERATURES
SEVERAL DEGREES COOLER THAN THIS. AT THIS TIME THERE STILL APPEARS
TO BE A DECENT AMOUNT OF AFTERNOON SUNSHINE SO WILL CONTINUE TO
TREND TOWARDS THE WARMER NAM/ECMWF SOLUTION WHICH HAPPENS TO BE
VERY SIMILAR TO THE PREVIOUS FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 337 AM CDT WED JUL 18 2012
THE GENERAL UPPER-LEVEL PATTERN THROUGH JULY 25TH WILL FEATURE
UPPER-LEVEL RIDGING OVER KANSAS AND UPPER-LEVEL SHORTWAVE TROUGHS
POSITIONED FAR TO THE NORTH AND WEST OF KANSAS ACROSS THE NORTHERN
ROCKIES AND SOUTHERN CANADA. HOT WEATHER WILL PERSIST THROUGHOUT THIS
PERIOD. 500MB HEIGHTS ARE PROGGED TO RISE THIS WEEK FROM 589 TO
596 DM AND THIS IMPLIES LOW TO MID-LEVEL WARMING GIVEN THAT SEA
LEVEL PRESSURE VALUES ARE EXPECTED TO CHANGE VERY LITTLE. SO HIGHS
SHOULD BE WELL OVER 100 FOR MOST OF SOUTHWEST KANSAS, EXCEPT
CLOSER TO 100 NEAR THE COLORADO BORDER. SOME READINGS NEAR
107-109F ARE POSSIBLE BY MONDAY AND TUESDAY.
THE SLOW MOVING FRONTAL BOUNDARY MENTIONED IN THE SHORT TERM DISCUSSION
THAT IS CURRENTLY OVER NORTHWEST KANSAS WILL STALL OUT IN THE MIDDLE
OF THE UPPER-LEVEL RIDGE AXIS SOMEWHERE OVER SOUTHWEST KANSAS ON
THURSDAY. THEREFORE, THERE IS A SMALL CHANCE FOR THUNDERSTORMS
WHEREVER THIS BOUNDARY STALLS OUT AND THIS IS HARD TO PINPOINT AT
THIS TIME. SO SMALL CHANCES FOR STORMS WERE INTRODUCED FOR MUCH OF
THE FORECAST AREA. EVEN THOUGH THE LOW-LEVEL MOISTURE IS MIXING
OUT IN THE HOT PLUME AS IT TRIES TO MOVE NORTHWARD INTO THE
PLAINS, SOME SURFACE BASED CAPE BETWEEN 400 AND 800 J/KG, ALONG
WITH MODEST LOW-LEVEL CONVERGENCE AND STRONG SURFACE HEATING MAY
BE ENOUGH TO INITIATE A FEW HIGH BASED THUNDERSTORMS. GIVEN THE
LOW CAPE VALUES, VERY LOW VERTICAL WIND SHEAR AND HIGH CLOUD
BASES, THE MAIN THREAT WITH THESE STORMS IS GUSTY WINDS AS HIGH AS
50 MPH AS WELL AS ANY CLOUD TO GROUND LIGHTNING.
AFTER THURSDAY, THERE IS LITTLE IN THE WAY OF HOPE FOR THUNDERSTORMS
THROUGH JULY 25TH GIVEN THE AFOREMENTIONED STRONG UPPER-LEVEL
RIDGING AND ABSENCE OF FRONTS. HOWEVER, THE LONGER RANGE MODELS
ARE OFTEN UNABLE TO RESOLVE SMALLER SCALE BOUNDARIES THAT COULD
SERVE TO INITIATE ISOLATED THUNDERSTORMS. BUT IT IS PROBABLY SAFE
TO SAY THAT WIDESPREAD BENEFICIAL RAINS ARE HIGHLY UNLIKELY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1211 AM CDT WED JUL 18 2012
VARIABLE WINDS CAN BE EXPECTED OVER THE NEXT SEVERAL HOURS AS
SEVERAL OUTFLOW BOUNDARIES CROSS WESTERN KANSAS. AFTER 9Z THE
WINDS ARE EXPECTED TO BECOME SOUTH AGAIN AT AROUND 10KTS. ONLY MID
LEVEL MOISTURE WILL ACCOMPANY AN UPPER LEVEL DISTURBANCE AS IT
CROSSES WESTERN KANSAS EARLY THIS MORNING. IN ADDITION A FEW
WIDELY SCATTERED SHOWERS WILL BE POSSIBLE IN THE HAYS AREA THROUGH
08Z. AFTER 12Z A TROUGH OF LOW PRESSURE WILL SLOWLY MOVE EAST
ACROSS WESTERN KANSAS AND BY 21Z THIS BOUNDARY IS EXPECTED TO
EXTEND FROM NEAR HAYS TO GARDEN CITY. ALONG THIS BOUNDARY WIDELY
SCATTERED THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND
EARLY THIS EVENING...ESPECIALLY IN NORTH CENTRAL KANSAS NEAR HAYS
BETWEEN 21Z AND 03Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 72 103 74 / 20 20 20 20
GCK 100 69 101 73 / 20 20 20 10
EHA 98 70 100 72 / 10 20 0 0
LBL 101 69 101 73 / 10 20 10 0
HYS 104 73 106 76 / 20 20 20 20
P28 104 73 105 77 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
229 AM CDT WED JUL 18 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1211 AM CDT WED JUL 18 2012
A -17C 500MB LOW WAS LOCATED OVER NORTHERN CALIFORNIA AS OF 00Z
WEDNESDAY. STRONGEST 250MB WINDS AROUND THIS UPPER LOW EXTENDED FROM
THE BASE OF THIS UPPER LOW NORTHEASTWARD INTO EASTERN
OREGON/SOUTHWEST IDAHO. AN UPPER LEVEL RIDGE EXTENDED FROM NORTHERN
NEW MEXICO INTO EASTERN WYOMING AT 00Z WEDNESDAY WITH THE CENTER
OF THIS ANTICYCLONIC FLOW APPEARING TO BE LOCATED OVER SOUTHERN
COLORADO BASED ON 500MB ANALYSIS. A TROUGH OF LOW PRESSURE AT THE
SURFACE AT 01Z EXTENDED FROM NORTH CENTRAL KANSAS INTO SOUTHEAST
COLORADO. THE LATEST RADAR LOOP, AS OF 05Z, INDICATED THAT SEVERAL
OUTFLOW BOUNDARIES FROM THE CONVECTION THAT DEVELOPED EARLIER THIS
EVENING NEAR THIS BOUNDARY WERE NOW LOCATED ACROSS WESTERN AND
NORTH CENTRAL KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 226 AM CDT WED JUL 18 2012
CLOUDS INCREASING IN AREAL COVERAGE EARLY THIS MORNING NEAR A
500MB DEFORMATION ZONE/COL BASED ON 00Z ANALYSIS. ALL THE MODELS
PICK UP ON THIS FEATHER AND INCREASE 700MB RELATIVE HUMIDITY
VALUES EARLY THIS MORNING. THE HRRR EVEN SUGGESTS SOME LIGHT
PRECIPITATION WILL BE POSSIBLE. BASED ON LATEST RADAR TRENDS WILL
FOLLOW THE HRRR AND INTRODUCE SOME LIGHT PRECIPITATION EARLY THIS
MORNING IN SOUTH CENTRAL KANSAS.
AN UPPER LEVEL RIDGE WILL THEN BUILD ACROSS THE CENTRAL AND
NORTHERN ROCKIES LATER TODAY AS THE CENTER OF THIS HIGH, LOCATED
OVER COLORADO, MOVES VERY LITTLE. MODELS REMAIN IN GOOD AGREEMENT
IN MOVING A SURFACE BOUNDARY ACROSS WESTERN KANSAS DURING THE EARLY
MORNING HOURS AND BY THE EARLY AFTERNOON THIS BOUNDARY IS EXPECTED
TO EXTEND FROM HAYS TO GARDEN CITY TO NEAR ELKHART. FORECAST MODEL
SOUNDINGS NEAR THIS SURFACE TROUGH INDICATED SOME MID LEVEL
INSTABILITY AND MOISTURE IN THE 700-600MB LEVEL WILL BE PRESENT AS
AN UPPER LEVEL DISTURBANCE ROTATES AROUND THE UPPER HIGH AND
CROSSES INTO WESTERN KANSAS. GIVEN THE ESTIMATED TIMING OF THIS
UPPER LEVEL DISTURBANCE ALONG WITH WHERE THE BETTER THE LATE DAY
INSTABILITY IS EXPECTED WILL INCREASE THE PRECIPITATION CHANCES
NEAR THE SURFACE BOUNDARY LATE THIS AFTERNOON...ESPECIALLY IN
NORTH CENTRAL KANSAS. THE INVERTED V TYPE OF SOUNDINGS CONTINUE TO
SUGGEST THE PREVIOUS SHIFT HAD THE RIGHT IDEA WITH THE PRIMARY
HAZARD BEING WINDS GUSTY UP TO 45 MPH AND CLOUD TO GROUND
LIGHTNING.
CLOUD COVER THIS AFTERNOON WILL PLAY AN IMPORTANT ROLE ON
TEMPERATURES TODAY. MIXING DOWN THE NAM AND ECMWF 850MB
TEMPERATURES AT 00Z THURSDAY SUGGESTS HIGHS WILL BE MAINLY IN THE
100 TO 104 DEGREE RANGE. INCREASING AFTERNOON CLOUDS AHEAD OF THE
UPPER LEVEL DISTURBANCE HOWEVER MAY RESULT IN KEEPING TEMPERATURES
SEVERAL DEGREES COOLER THAN THIS. AT THIS TIME THERE STILL APPEARS
TO BE A DECENT AMOUNT OF AFTERNOON SUNSHINE SO WILL CONTINUE TO
TREND TOWARDS THE WARMER NAM/ECMWF SOLUTION WHICH HAPPENS TO BE
VERY SIMILAR TO THE PREVIOUS FORECAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 238 PM CDT TUE JUL 17 2012
ALOFT, THE PERSISTENT STRONG UPPER LEVEL HIGH PRESSURE AREA, FROM
THE 700, 500, AND 300MB LEVELS AND UPWARDS, WILL REMAIN OVER
KANSAS AND NOT VENTURE TOO FAR THROUGH DAY 7. THIS WILL KEEP HOT
TEMPERATURES GOING THROUGH AT LEAST THE DAY 7 PERIOD, WITH LITTLE
OR NO RELIEF FROM ANY RAIN. MAXIMUM TEMPERATURES WILL AVERAGE
AROUND 100 TO 102F IN THE WEST NEAR THE COLORADO LINE, AND FROM
THE 103 TO 105F RANGE IN THE EASTERN FORECAST AREA NEAR HAYS,
LARNED, PRATT AND MEDICINE LODGE. THE 850MB-1000MB THICKNESS
VALUES FROM THE ECMWF AND GFS MODELS RANGE FROM ABOUT 1440M IN OUR
WEST ZONES TO 1556M IN OUR EAST THURSDAY. BASICALLY, THOSE SAME
RANGES EXIST FROM FRIDAY THROUGH MONDAY. WITH THIS SAID, THERE
COULD BE AN HEAT ADVISORY WARRANTED A DAY OR TWO FOR OUR EASTERN-
MOST COUNTIES FOR A SMALL PERIOD OF THE AFTERNOONS, BUT EXACTLY
WHERE AND HOW LARGE OF AN AREA TO INCLUDE WILL NEED TO BE TAILORED
LATER, AS EACH DAY APPROACHES. FURTHER, DUE TO DEW POINTS ONLY IN
THE MID TO UPPER 50S, THE HEAT INDEX VALUES OF 105F WILL BE HARD
TO REACH. MINIMUM TEMPERATURES WILL BE ELEVATED, AND GENERALLY
RANGE FROM THE LOWER 70S IN OUR WEST ZONES ALONG THE COLORADO
BORDER TO THE UPPER 70S IN OUR EAST NEAR LARNED, PRATT, AND
MEDICINE LODGE.
IN THE NEAR TERM OF THE EXTENDED PERIOD, WEDNESDAY EVENING WILL SEE
A SLIGHT CHANCE FOR THUNDERSTORMS IN OUR NORTHWEST, BASICALLY
NORTHWEST A HAYS TO LIBERAL LINE. A TROUGH OF LOW PRESSURE WILL BE
OVER WESTERN KANSAS WEDNESDAY, AND THE HEATING FROM THE AFTERNOON
WILL PROBABLY TRIGGER WIDELY SCATTERED STORMS WEDNESDAY AFTERNOON
AND LAST INTO THE EVENING. I PLAN TO LEAVE THE PREVIOUS FORECAST
GOING, DIMINISHING POPS TO LESS THAN 14 PERCENT BY 10 PM CDT. SINCE
ANY OT THESE STORMS WILL LIKELY BE HIGH BASED, THE QPF AMOUNTS WILL
BE ON THE VERY LIGHT SIDE AROUND 0.01-INCH. AFTER WEDNESDAY NIGHT,
NO POPS WILL BE IN THE EXTENDED FORECAST, AND ALL MEDIUM RANGE
MODELS SUPPORT THIS DRY FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1211 AM CDT WED JUL 18 2012
VARIABLE WINDS CAN BE EXPECTED OVER THE NEXT SEVERAL HOURS AS
SEVERAL OUTFLOW BOUNDARIES CROSS WESTERN KANSAS. AFTER 9Z THE
WINDS ARE EXPECTED TO BECOME SOUTH AGAIN AT AROUND 10KTS. ONLY MID
LEVEL MOISTURE WILL ACCOMPANY AN UPPER LEVEL DISTURBANCE AS IT
CROSSES WESTERN KANSAS EARLY THIS MORNING. IN ADDITION A FEW
WIDELY SCATTERED SHOWERS WILL BE POSSIBLE IN THE HAYS AREA THROUGH
08Z. AFTER 12Z A TROUGH OF LOW PRESSURE WILL SLOWLY MOVE EAST
ACROSS WESTERN KANSAS AND BY 21Z THIS BOUNDARY IS EXPECTED TO
EXTEND FROM NEAR HAYS TO GARDEN CITY. ALONG THIS BOUNDARY WIDELY
SCATTERED THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND
EARLY THIS EVENING...ESPECIALLY IN NORTH CENTRAL KANSAS NEAR HAYS
BETWEEN 21Z AND 03Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 72 102 74 / 20 20 0 0
GCK 100 69 101 73 / 20 20 0 0
EHA 98 70 100 72 / 10 20 0 0
LBL 101 69 101 73 / 10 20 0 0
HYS 104 73 105 76 / 20 20 0 10
P28 104 73 103 77 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...BURKE
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1206 AM EDT WED JUL 18 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
COLD FRONT IS WELL TO THE SOUTH OF UPPER MICHIGAN AS PORTIONS OF
SOUTHERN WICSONSIN AND LOWER MICHIGAN CONTINUE TO BAKE. YET...DRY
DAY THAT WAS SUPPOSED TO BE OVER MOST OF THE AREA HAS HAD TOUGH TIME
TAKING SHAPE. MAIN CULPRIT FOR THE SHRA CURRENTLY ROAMING CNTRL UPR
MICHIGAN SEEMS TO HAVE BEEN A SUBTLE H6-H5 JET STREAK ALONG WITH
RIBBON OF LINGERING HIGHER H7 DWPNTS ACROSS THE AREA. ADDITIONAL
LIFT IS PROVIDED BY A WEAK SHORTWAVE NOW PUSHING INTO WESTERN LK
SUPERIOR. BULK OF ANY TSRA HAVE STAYED OVR NORTHERN WISCONSIN ALONG
NORTH EDGE OF 1-6KM MUCAPE GRADIENT. SHRA IN THE NORTH HAVE NOT
BEEN ALL THAT HEAVY...WITH ONLY A FEW HUNDREDTHS OBSERVED AT RAIN
GAGES OVR WESTERN UPR MICHIGAN THIS AFTN. EXPECT ALL THE MENTIONED
FORCING MECHANISMS TO DRIFT SOUTH OUT OF THE AREA EARLY THIS EVENING
AND HAVE PUT AN END TO POPS AT THAT TIME. RAPID REFRESH RUC MODEL
/HRRR/ WHICH DID NOT DO WELL SHOWING THE SHRA/TSRA FOR MUCH OF THE
MORNING FINALLY CAUGHT ON BY EARLY THIS AFTN...AND FCSTS A SIMILAR
FATE TO PRECIP THIS EVENING.
CLEARING SKIES THEN EXPECTED FM NORTHWEST TO SOUTHEAST THROUGH THE
EVENING. THINK THE CLEARING COULD LEAD TO FOG OVERNIGHT TONIGHT
THROUGH EARLY WEDNESDAY MORNING. PLUSES FOR FOG FORMATION ARE ADDED
SFC MOISTURE FROM THE RAIN TODAY/MINIMAL MIXING OR DRYING TODAY
ALONG WITH FAIRLY LIGHT WINDS/COOLING TEMPS. BEST CHANCE FOR FOG
WILL BE OVER WEST HALF AND ALSO WHERE NORTHEAST WINDS UPSLOPE
/HIGHER TERRAIN OF WEST AND NORTH CENTRAL/. LOOKS LIKE AM ON MY
OWN ON THIS ONE THOUGH AS NO GUIDANCE HAS REALLY ANY HINT OF FOG
TONIGHT. GIVEN THOSE SIGNALS...IT IS TOUGH TO GO WITH ANYTHING MORE
THAN PATCHY FOG AT THIS POINT.
IF ANY FOG/STRATUS DEVELOPS TONIGHT IT WILL DEPART SHORTLY AFTER
SUNRISE ON WEDNESDAY MORNING SINCE IT WILL SFC BASED/SHALLOW. WITH
MAINLY SUNNY SKIES FOR THE AFTN HIGH TEMPS SHOULD RISE WELL INTO
THE 70S MOST AREAS WITH EVEN SOME LOWER 80S POSSIBLE TOWARD THE
WISCONSIN BORDER. DAYTIME MIXING WILL RESULT IN LESS HUMID
CONDITIONS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
AREA WILL BE BETWEEN TWO UPPER TROUGHS ON WED NIGHT...ONE OVER
QUEBEC AND THE OTHER OVER THE PAC NW. THIS WILL LEAD TO A RIDGE
OVER THE NRN PLAINS AND CANADIAN PRAIRIES THAT WILL TRY TO PUSH
EAST TOWARDS THE CWA...BUT WILL BE HELD OFF REINFORCING NRN STREAM
WAVES ATTEMPTING TO KEEP THE UPPER TORUGH OVER QUEBEC. THIS WILL
PUT THE CWA ON THE EDGE OF THE WARM TEMPS THIS WEEKEND...UNTIL THE
UPPER RIDGE FINALLY MOVES OVERHEAD DURING THE BEGINNING OF NEXT
WEEK.
CANADIAN HIGH PRESSURE RIDGE WILL BE OVER UPPER MI ON WED NIGHT AND
THEN GRADUALLY SHIFT SOUTHEAST THROUGH THE REST OF THE WORK WEEK AS
THE TROUGH OVER QUEBEC MOVES INTO THE NEW ENGLAND STATES. MODELS
CONSISTENT ON A SHORTWAVE SLIDING THROUGH THE FLOW ON WED NIGHT INTO
THURS...BUT VARY CONSIDERABLY ON THE LOCATION/INTENSITY. ECMWF IS
THE FARTHEST N AND STRONGEST WITH THE LLVL WAA OVER NRN WI...WHILE
THE REST OF THE MODELS ARE MUCH WEAKER WITH THE WAA AND FARTHER SW.
DRY AIR DOES TRY TO BREAK DOWN THE MOISTURE IN THE MID LVLS OVER THE
SW HALF OF THE CWA WED NIGHT INTO THURS MORNING...BEFORE DIMINISHING
IN THE AFTN. LLVL DRY AIR WILL LIKELY KEEP IT MID CLOUDS AND WITH
THE BEST FORCING LIKELY STAYING TO THE S...WANTED TO KEEP POPS
IN NRN WI. BUT WITH 12Z ECMWF CONTINUING TO SHOW PCPN MAKING IT
INTO UPPER MI...WILL CONTINUE MENTION SLIGHT CHANCES JUST OVER
THE WI BORDER.
OTHERWISE...HIGH PRESSURE RIDGE AND DRY CANADIAN AIR WILL KEEP THE
AREA MOSTLY/PARTLY CLEAR INTO FRI. TEMPS WILL BE SLIGHTLY ABOVE
NORMAL ON THURS AND THEN WARM SLIGHTLY ON FRI...AS WARM AIR ALOFT
STARTS TO WORK E AND BACK OVER THE CWA.
NRN STREAM WAVE SLIDING THROUGH CNTRL CANADA FRI NIGHT AND INTO NRN
ONTARIO WILL TRY TO PUSH A COLD FRONT TOWARDS THE AREA ON SAT INTO
SUN. IT ACTUALLY MOVES INTO NRN MN ON FRI...BUT STALLS AS IT
RUNS INTO THE SFC HIGH OVER UPPER MI. WITH IT BEING A GOOD WAYS AWAY
FROM IT/S SOURCE...AND LIMITED CONVERGENCE...EXPECT PCPN TO BE
SCATTERED ALONG THE FRONT. THUS...WILL CONTINUE TO MENTION SLIGHT
AND LOW CHANCE POPS FRI NIGHT INTO SUN. FRONT FINALLY SLIDES S OF
THE AREA ON SUN NIGHT AND WILL END PCPN CHANCE AT THAT POINT.
UPPER RIDGE THEN REALLY BUILDS IN MON/TUES AS ANOTHER CANADIAN HIGH
PRESSURE RIDGE SLIDES INTO THE AREA. THERE ARE A FEW
WEAK SHORTWAVES TRYING TO ROUND THE RIDGE...BUT WITH LITTLE
TO NO INSTABILITY...WILL KEEP THE FORECAST DRY FOR MON AND
MON NIGHT. ANOTHER COLD FRONT WILL LIKELY APPROACH THE UPPER GREAT
LAKES LATE TUES AFTN AND INTO WED...SO HAVE BROUGHT IN CHANCES
OVER THE WEST. HIGHS ARE STILL EXPECTED TO BE ABOVE NORMAL THROUGH
THE PERIOD...IN THE 80S AND LOW 90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1206 AM EDT WED JUL 18 2012
THERE IS SOME CONCERN THAT FOG MAY DEVELOP TONIGHT AFTER ADDED
MOISTURE FROM LIGHT SHOWERS TODAY AND AS NIGHTTIME COOLING LEADS
TO BASED INVERSION. THE BEST CHANCE FOR FOG WILL BE AT KSAW WITH
IDEAL UPSLOPE LOW-LEVELS WIND FCST. PATCHY GROUND FOG MAY ALSO
AFFECT KIWD. HOWEVER...CONFIDENCE IS LOW GIVEN SLOW INFLUX OF DRIER
AIR INTO THE REGION WITH WEAK LOW LEVEL ACYC FLOW. A PERIOD OF MID
CLOUDS WILL ALSO LIMIT RADIATIONAL COOLING AT KCMX. VFR CONDITIONS
ARE EXPECTED AFTER ANY LOW CLOUDS/FOG DIMINISH WEDNESDAY MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 343 PM EDT TUE JUL 17 2012
HIGH PRES BUILDING S TOWARD THE UPPER LAKES WILL ARRIVE IN FULL
FORCE LATE TONIGHT INTO WEDNESDAY. THE HIGH WILL REMAIN OVERHEAD
THROUGH THE UPCOMING WEEKEND...SO WINDS WILL BE ON THE LIGHT SIDE...
MAINLY LESS THAN 15 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
409 AM CDT WED JUL 18 2012
.DISCUSSION...
SFC-925MB FRONT DOWN ALONG THE IOWA BORDER THIS MORNING...BUT H85
FRONT BISECTS THE THE MPX CWA FROM THE MADISON AREA OVER TO CHIP
FALLS/EAU CLAIRE. HAVE BEEN SEEING VERY WEAK THETA-E ADVECTION
NORTH OF THIS BOUNDARY AND THAT COMBINED WITH PWATS UP AROUND 2
INCHES AND MUCAPE AROUND 1500 J/KG HAS ALLOWED FOR SCATTERED
CONVECTION NORTH OF THIS H85 BOUNDARY FROM NE SODAK OVER TO GREEN
BAY. THIS WAA REGIME IS IN RESPONSE TO A SHORTWAVE THAT CAN
ACTUALLY BE SEEN ON A RADAR MOSAIC...WITH A NICE SPIN IN THE
REFLECTIVITY DOWN AROUND YANKTON...SD. THE RAP HAS ALSO BEEN
SHOWING A NICE PV ANOMALY ACROSS ERN SODAK THAT HAS HELPED
GENERATE MORE WIDESPREAD CONVECTION THERE. AS WE GO THROUGH THE
DAY...BOUTS OF SCT CONVECTION WILL CONTINUE TO OCCUR THROUGH THE
MORNING WITHIN THE WEAK CORRIDOR OF H85 THETA-E ADVECTION FROM
MAINLY CENTRAL MN INTO CENTRAL WI. THE 18.05 HRRR REFLECTIVITY
FORECAST PROBABLY HAS THE RIGHT IDEA FOR THIS MORNING...JUST
DISPLACED A LITTLE TOO FAR NORTH. AS THE AFTERNOON ROLLS
AROUND...THE PV ANOMALY WILL BEGIN WORKING ACROSS THE SRN HALF OF
THE MPX AREA. HAVE MAINLY 40 TO 50 POPS WORKING ACROSS THE AREA
FROM WRN MN INTO WRN WI THOUGH TONIGHT AS THIS PV FEATURE MOVES
ACROSS. MAY NEED TO BUMP UP POPS MORE AS THIS UPPER FEATURE HAS
HAD LITTLE TROUBLE FORCING CONVECTION OVERNIGHT. AS FOR SVR
POTENTIAL WITH THIS ACTIVITY...LACK OF SHEAR COMBINED WITH
FREEZING LEVELS OVER 14K FEET WILL KEEP THE SVR POTENTIAL PRETTY
MINIMAL WITH THE MAIN THREAT BEING FROM GUSTS WINDS IF WE CAN GET
ROBUST ENOUGH STORMS TO RAPIDLY COLLAPSE.
BESIDE RECEIVING SOME MUCH NEEDED RAIN...THIS WAVE WILL ALSO
PROVIDE CLOUD COVER AND COOLER TEMPS ACROSS MOST OF THE CWA FOR
TODAY. THE ONLY EXCEPTION WILL BE ACROSS SRN MN. +28C 925MB TEMPS
WILL NOT BE TOO FAR AWAY FROM THE I-90 CORRIDOR...AND IF THEY DO
NOT SEE MUCH IN THE WAY OF CLOUD COVER BY THE AFTERNOON...THEN
WILL BE ANOTHER LOWER TO MIDDLE 90S DAY DOWN THERE. DEPENDING ON
CLOUD COVER DURATION...MAY HAVE SOME AREAS STAY IN THE 70S FOR
HIGHS TODAY...ESPECIALLY IN THE NORTHEAST SECTION OF THE
CWA...WHERE TEMPS THROUGH H85 WILL BE A BIT COOLER TO BEGIN WITH.
THESE COOLER TEMPS WILL CONTINUE INTO THURSDAY...FOR WRN WI AT
LEAST...AS STRONG NW FLOW SETS IN ALOFT BEHIND TODAYS SHORTWAVE.
FOR FRIDAY THROUGH TUESDAY...THE BIG PLAYER HERE WILL BE THE
STRONG UPPER RIDGE WE HAVE SEEN ALL SUMMER WAFFLING ACROSS THE
CONUS. BY THURSDAY...ANOTHER 595+DM H5 HIGH WILL BE BUILDING
ACROSS THE HIGH PLAINS WITH THE HEAT BUBBLE WE BEAT BACK SOME
TODAY RAPIDLY REBUILDING TO THE WEST. THIS H5 RIDGE WILL SLOWLY
SHIFT INTO THE CENTRAL PLAINS FROM THE WEEKEND INTO EARLY NEXT
WEEK. UP HERE...THE MPX CWA LOOKS TO BE SITTING NEAR THE NRN
PERIPHERY OF THE RIDGE. THE WARMEST DAYS OF THIS PERIOD LOOK TO BE
FRIDAY/SATURDAY AS THE NAM/ECMWF SHOW 594DM H5 HEIGHTS BUILDING UP
INTO CENTRAL MN INTO WRN WI. THE NAM IN PARTICULAR IS RATHER
AGGRESSIVE WITH WAA INTO THE AREA THESE DAYS...WITH ITS 925-850MB
TEMPS INDICATING ANOTHER ROUND OF UPPER 90S TO 102/3 TYPE HIGHS
BEING POSSIBLE BOTH DAYS. DID BUMP HIGHS UP SOME...ESPECIALLY FOR
FRIDAY...BUT MOST MODELS SHOW A NOCTURNAL CONVECTIVE SYSTEM FIRING
OFF TO THE NORTH FRI NIGHT...THAT MAY TRY TO LAY DOWN INTO NRN
SECTIONS OF THE MPX CWA SATURDAY. GIVEN THE UNCERTAINTIES WITH
CLOUD COVER FOR SATURDAY...WAS A BIT MORE CONSERVATIVE WITH HIGHS
THEN. DUE TO PROXIMITY TO UPPER RIDGE...THE MPX AREA WILL BE PRONE
TO ANY RING OF FIRE CONVECTION SATURDAY THROUGH MONDAY. BY
TUESDAY...BOTH THE ECMWF AND GFS CONTINUE TO SHOW A STRONGER COLD
FRONT SWEEPING ACROSS THE AREA...WHICH AT THIS POINT REPRESENTS
THE BEST CHANCES FOR RAIN AFTER TODAY. THIS FRONT ALSO LOOKS TO
PROVIDE ANOTHER 2 OR 3 DAY REPRIEVE FROM THE HEAT AS WELL.
&&
.AVIATION.../06Z TAF ISSUANCE/
TSRA/S ARE BEGINNING TO DEVELOP AS OF 430Z ACROSS PORTIONS OF S MN
AND EASTERN SD. THIS WILL BE THE MAIN AVIATION CONCERN IN THE
FIRST 6-9 HRS AS A COMPLEX OF TSRA/S ARE EXPECTED TO DEVELOP ACROSS
NE SD/WC MN...AND MOVE E-SE ACROSS SOUTHERN MN DURING THE MORNING
HRS.
ALTHOUGH SHORT TERM MODELS HAVE BEEN TRYING TO DEVELOP SHRA/TSRA
ACROSS SOUTHERN MN WITH EACH RUN...THE LATEST /01Z/ SEEMS TO HAVE
A HANDLE ON TSRA DEVELOP ACROSS SD. BASED ON THE LATEST MODEL
/RAP/ REFLECTIVITY FORECAST OVERNIGHT...WILL INTRODUCE A
TEMPORARY PERIOD OF SHRA/TSRA FOR AXN STARTING AT 8Z. STC/RWF WILL
FOLLOW ARND 10-12Z...WITH MSP/RNH ARND 12-14Z. THIS IS HIGHLY
DEPENDENT ON THE LATEST MODEL RUN AND CURRENT RADAR RETURNS. CHGS
IN VSBY/CIGS WILL LIKELY HAPPEN OVERNIGHT AS THIS COMPLEX OF
STORMS BEGINS TO ORGANIZE ACROSS NE SD/WC MN.
DUE TO VERY HIGH MOISTURE CONTENT...RAINFALL RATES WILL BE HIGH.
THEREFORE...IFR VSBYS ARE LIKELY...BUT TOO MANY UNCERTAINTIES TO
ADVERTISE IN THE CURRENT TAF PERIOD. WINDS WILL BE GENERALLY FROM
THE E/NE EARLY THIS MORNING...THEN MORE E/SE DURING THE DAY. DUE
TO UNCERTAINTIES OF THE COMPLEX OF STORMS DEVELOPING OVERNIGHT...WILL
ONLY CONCENTRATE ON THE FIRST 6-12 HRS OF THE TAF PERIOD. BEYOND
18Z...THERE WILL LIKELY BE ANOTHER CHC OF TSRA/SHRA ACROSS MPX TAF
SITES.
MSP...BASED ON THE CURRENT TRENDS OF THE RAP/RADAR RETURNS ACROSS
SD...WILL INTRODUCE A TEMPORARY PERIOD OF SHRA/TSRA AFT 12Z WITH
MVFR VSBYS. CIGS WILL LIKELY HOLD IN THE VFR RANGE...WITH ONLY
BRIEF PERIODS OF CIGS BELOW 2.5K. THE BEST TIME PERIOD FOR
SHRA/TSRA WILL OCCUR BETWEEN 12-15Z. WINDS WILL BE GENERALLY FROM
THE NE/E THRU 12Z...THEN MORE E/SE DURING THE DAY...BEFORE TURNING
BACK TO MORE EASTERLY OVERNIGHT.
OUTLOOK...
WED NIGHT/EARLY THU CHGS OF SHRA/TSRA WITH MAINLY VFR CIGS. BRIEF
PERIODS OF MVFR/IFR VSBYS IN HEAVIER RAINFALL.
THU/FRI/SAT. MAINLY VFR. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JLT
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
142 AM EDT WED JUL 18 2012
.SYNOPSIS...
AFTER A DAY OF RECORD OR NEAR RECORD HEAT...A COLD FRONT WILL SLIP
SOUTH TO TRIGGER SCATTERED THUNDERSTORMS ACROSS PORTIONS OF CENTRAL
NEW YORK TONIGHT...MAINLY ALONG THE NEW YORK THRUWAY REGION...SOME
OF WHICH COULD BE SEVERE. THE FRONT WILL CONTINUE TO PUSH SOUTH
FOR ADDITIONAL POSSIBLE SEVERE THUNDERSTORMS FOR MAINLY SOUTHERN
NEW YORK AND NORTHEAST PENNSYLVANIA WEDNESDAY. COOLER AND DRIER
AIR WILL BUILD IN BEHIND THE FRONT THURSDAY AND FRIDAY...FOLLOWED
BY WARMING TEMPERATURES OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1 AM UPDATE...
04Z SUBJECTIVE SURFACE ANALYSIS PLACES MAIN COLD FRONT ALONG A
HAMILTON, ON...TO TRENTON, ON...TO WATERTOWN LINE. AHEAD OF THIS
BOUNDARY OVERALL CONVECTIVE ACTIVITY HAS SHOWN A NOTICEABLE
WEAKENING TREND IN RECENT HRS AS MAIN MID-LEVEL FORCING REMAINS
WELL NORTH OF THE FCST AREA. EARLIER...RADAR TRENDS SHOWED RENEWED
CONVECTION JUST NORTH OF THE LAKE ONTARIO SHORE...HOWEVER NO NEW
DEVELOPMENT IS APPARENT WITHIN THE LAST HR OR SO. REGIONAL HIGH-
RES CONVECTION ALLOWING MODELS SUGGEST A CONTINUED WEAKENING TREND
OVERNIGHT AS MAIN COLD FRONT CONTINUES TO OUTRUN ANY MID-LEVEL
SUPPORT WHICH SHOULD JUST SKIRT NORTHERN PORTIONS OF OUR FCST
AREA. IN FACT...LATEST WATER VAPOR IMAGERY SHOWS A NICE SHORTWAVE
TROUGH LOCATED JUST NORTH OF LAKE HURON...WHICH IS JUST A BIT TOO
FAR NORTH TO HAVE ANY APPRECIABLE AFFECT ON CONVECTIVE TRENDS
ACROSS OUR REGION. THAT SAID...CONSIDERING RECENT RADAR TRENDS AND
GUIDANCE FROM REGIONAL HIGH-RES MODELS TO INCLUDE THE HRRR AND
WRF-ARW...HAVE ELECTED TO LOWER POPS FOR THE REMAINDER OF THE
MORNING HRS AS NOCTURNAL STABILIZATION PROCESSES CONTINUE. DESPITE
THIS...EXPECT THE FRONT TO GRADUALLY SINK THROUGH THE FINGER LAKES
INTO THE SOUTHERN TIER BY MORNING. AFTER 12Z...CONVECTION WILL
ONCE AGAIN DEVELOP ALONG THE BOUNDARY AS DAYTIME HEATING ONCE
AGAIN COMMENCES. WILL FURTHER INVESTIGATE SEVERE POTENTIAL PRIOR
TO THE NEXT UPDATE HOWEVER INITIAL IMPRESSIONS SUGGEST BEST
FORCING WILL AGAIN REMAIN NORTH OF THE AREA WHICH MAY INHIBIT
WIDESPREAD SEVERE COVERAGE.
10 PM UPDATE... CONVECTIVE COVERAGE HAS INCREASED A BIT SINCE
EARLIER THIS EVE ACRS UPSTATE NY...JUST S OF THE SFC FRNT...AND
ALG THE LEADING EDGE OF THE BETTER INSTAB (ML CAPES OF 1000-2000
ATTM STILL OVER MOST OF THE CWA). HOWEVER...THE STGR STORMS/DEEPER
CORES SEEM TO BE CLOSELY TIED TO A CONVERGENCE BNDRY NEAR THE S SHORE OF
LK ONT...WITH A GENERAL WEAKENING TREND NOTED SO FAR ONCE THEY
PUSH FARTHER INLAND.
AS THE SFC FRNT CONTS GRADUALLY SWD OVERNIGHT AND A WELL DEFINED
UPR-LVL WAVE COMES ACRS LK HURON/SRN ONT/FAR NRN NY...WE THINK AN
AREA OF SHRA/TSRA WILL SLOWLY PENETRATE FARTHER SWD ACRS CNY...AND
PERHAPS THE FAR NRN TIER OF PA TWDS DAYBREAK. IN
GENERAL...COVERAGE SHOULD LESSEN WITH SWD EXTENT...AS THE STORMS
OUTRUN THE BETTER FORCED ASCENT AND MORE PRONOUNCED DEEP-LYRD
SHEAR OFF TO THE N. OVERALL...THE SVR THREAT SEEMS MARGINAL...BUT
AN ISOLD STG/SVR STORM CAN`T BE RULED OUT...AND WE`LL CONTINUE TO
MONITOR DEVELOPMENTS.
PREV DISC... 7 PM UPDATE... CONDS REMAIN VERY QUIET ATTM
THROUGHOUT CNY/NE PA. THE AMS IS MODERATELY UNSTABLE (ML CAPES OF
1000-2000...AND LOCALLY HIGHER)...BUT LARGE-SCALE SUPPORT IS
LACKING. ACTIVE CONVECTION REMAINS CONFINED MUCH CLOSER TO THE SFC
FRNTL BNDRY...AND ALSO FORCING FROM A SERIES OF UPR-LVL
WAVES...FROM WI/NRN MI EWD THROUGH SRN ONT AND FAR UPSTATE NY.
AS THE NGT PROGRESSES...WE STILL EXPECT THAT THE SFC FRNT WILL CONTINUE
ITS SLOW SWD PUSH...AND ALSO THAT A WELL DEFINED UPR-LVL PV LOBE
WILL TRACK ESEWD FROM THE NRN LKS RGN TWDS UPSTATE NY AFTER 06Z.
ALTHOUGH AVAILABLE INSTABILITY SHOULD BE SOMEWHAT LESS BY
THEN...THERE WILL LIKELY BE ENOUGH OF IT (ML CAPES STILL NEAR OR
ABV 1000) TO INITIATE SOMEWHAT BETTER COVERAGE OF
SHRA/TSRA...GIVEN IMPROVED LIFT FROM JUST MENTIONED SYSTEMS.
POP/WX GRIDS WERE TWEAKED TO INDICATE ONLY ISOLD COVERAGE IN THE
FAR N THROUGH MUCH OF THE EVE (03-06Z)...WITH SCTD CONVECTION
COMING IN FROM WNW TO ESE IN THE 06-10Z TIME FRAME. OVERALL...WE
FEEL THE SVR THREAT IS SOMEWHAT LIMITED...BUT COMBINATION OF
LINGERING INSTAB...IMPROVING DEEP-LYRD SHEAR (0-6 KM VALUES OF
30-40 KT)...AND BETTER FORCED ASCENT COULD CONCEIVABLY TRIGGER A
FEW STG/SVR STORMS LATER TNT. WE`LL CONTINUE TO MONITOR.
JUST MINOR CHGS MADE TO NEAR-TERM TEMP/DEW PT GRIDS EARLY THIS EVE.
EARLIER DISC... 300 PM UPDATE... SEVERE THUNDERSTORM WATCH REMAINS IN
EFFECT UNTIL 9 PM FOR ONEIDA COUNTY...THOUGH IT WILL TAKE UNTIL
NEAR THE END OF THAT WATCH /PERHAPS EVEN AFTER/ FOR THE THREAT TO
PEAK. HEAT ADVISORY ALSO REMAINS IN EFFECT FOR THE LAKE PLAIN TO
MOHAWK VALLEY WHERE HEAT INDICES ARE NEAR OR SLIGHTLY ABOVE 100
DEGREES. ACTUAL TEMPERATURE IN SYRACUSE WITH DOWNSLOPING MANAGED
TO HIT 100 DEGREES SO FAR...EASILY SHATTERING THE DAILY
RECORD...AND GETTING ONLY 2 DEGREES FROM THE ALL TIME RECORD OF
102 SET JULY 9 1936.
FORECAST UPDATED FOR ANTICIPATED EVOLUTION OF CONVECTIVE
DEVELOPMENT...ESPECIALLY NY THRUWAY REGION...THOUGH DELAYED BY A
COUPLE HOURS DEEPER INTO THE EVENING FOR PEAK CHANCES. SURFACE
FRONT EXTENDS ROUGHLY ALONG THE ST. LAWRENCE VALLEY...THROUGH
ONTARIO /JUST NORTH OF LAKE ONTARIO/...BACK TO LAKE HURON AND
CENTRAL LOWER MICHIGAN. IT IS SET TO SAG SLOWLY SOUTH THROUGH
THE AREA LATE THIS EVENING THROUGH MIDDAY WEDNESDAY. SOUTH OF THE
FRONT...ATMOSPHERE WILL BE VERY WARM NOT JUST AT THE SURFACE BUT ALSO
MID LEVELS...INCLUDING 850 MB AT LEAST 23 DEG CELSIUS. THIS MID LEVEL
FOR NOW IS KEEPING CONVECTIVE INHIBITION OVER THE AREA. LATE EVENING
INTO TONIGHT...WE LOSE DIURNAL HEATING BUT CONDITIONS ALOFT BECOME
MORE FAVORABLE WITH WINDS AT UPPER LEVELS GOING FROM CONVERGENT TO
MORE NEUTRAL...AND MID LEVEL LAPSE RATES INCREASE. THE BIG QUESTION IS
WHETHER CONVECTION CAN INITIATE UPSTREAM /PERHAPS FROM THE WAVE
NOW IN UPPER WISCONSIN-NORTHERN MICHIGAN/...AND HOW FAR WILL IT
CARRY THROUGH THE AREA. THE ONE CERTAINTY HERE...IS THAT WITH
INVERTED-V IN THE LOW LEVELS...AND 35-50 KT OF SHEAR THROUGHOUT
THE 2KM-6KM LAYER...CONVECTION WILL BE CAPABLE OF STRONG
WINDS...WHILE LARGE HAIL AND ISOLATED TORNADOES ARE NOT AS LIKELY
BUT ALSO NOT OUT OF THE QUESTION.
BEST CHANCES WILL BE LATE THIS EVENING ACROSS THE NORTHERN
ZONES...ESPECIALLY ALONG AXIS OF THE NEW YORK THRUWAY...AND
PERHAPS EDGING FARTHER SOUTH TO AT LEAST FINGER LAKES-CATSKILLS
AXIS OVERNIGHT AS IT DIMINISHES WITH DECREASING INSTABILITY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
315 PM UPDATE...
STORM PREDICTION CENTER PLACES SOUTHERN TIER/CATSKILLS AND
NORTHEAST PENNSYLVANIA IN SLIGHT RISK FOR SEVERE WEATHER...WITH 30
PCT DAMAGING WIND RISK CONTOUR INCLUDING MUCH OF NORTHEAST PA.
UPPER DIVERGENCE COINCIDES WITH FRONTAL PASSAGE IN THE MORNING
HOURS...YET LOW LEVEL CONVERGENCE AND DIURNAL HEATING PEAK AS THE
FRONT IS HEADING OUT OF THE AREA. SHEAR IS NOT AS STRONG
WEDNESDAY...AS COMPARED TO THIS AFTERNOON/TONIGHT...BUT OVERALL
LOOKING QUITE ACTIVE FOR THE SOUTHERN HALF OF THE AREA LATE
MORNING INTO EARLY AFTERNOON. ALSO EXPECTING EARLIER INITIATION OF
CONVECTION BECAUSE OF FAVORABLE UPPER LEVEL SUPPORT.
LOWER ELEVATIONS IN THE SOUTHERN ZONES COULD STILL MANAGE 90
DEGREES WITH UNCOMFORTABLE UPPER 60S/NEAR 70 DEW POINTS...BUT
OTHERWISE TURNING COOLER CENTRAL AND NORTH...AS FRONT CONTINUES
TO SLIDE SOUTH...AND DEW POINTS DROP. ANY LINGERING CONVECTION
WEDNESDAY EVENING QUICKLY SHIFTS SOUTH. LOWS IN UPPER 50S NORTH TO
MID-UPPER 60S SOUTH BY DAWN THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
1 PM UPDATE...
COLD FRONT PUSHES SOUTHEAST THROUGH PA AND NJ THURSDAY WITH SURFACE
HIGH PRESSURE BUILDING INTO NY. UPPER LEVEL TROUGH IS OVER NEW
ENGLAND AND PULLING AWAY TO THE NORTHEAST. BY MIDDAY FRI A
SHORT-WAVE APPROACHES AND MAY HELP TO TRIGGER SOME SHOWERS ACROSS
THE POCONO AREA AND WYOMING VALLEY. WEAK RIDGING DURING THE DAY
SATURDAY WITH FAIR SKIES AND HIGHS IN THE MID 80S. WARM FRONT MOVES
THROUGH SATURDAY NIGHT WITH BRINGING SOME CLOUDS AND A CHANCE OF
TSTMS EAST OF LAKE ONTARIO INTO ONEIDA COUNTY. SUNDAY A COLD FRONT
AND UPPER LEVEL TROUGH APPROACH BRINGING A CHANCE FOR SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON INTO MONDAY AS A WEAK COLD FRONT
MOVES SOUTHEAST ACROSS THE REGION. HIGH PRESSURE BUILDS IN TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
COLD FNT DROPPING THRU THE FCST AREA THIS MRNG. NIGHT TIME AIR IS
STABILIZING THE SNDG DESPITE THE FNT. SO...STILL A CHANCE OF SOME
MVFR SHRS UP NORHT ALONG WITH SOME LGT FOG...OTRW GNRL VFR CONDS
OVRNGT INTO EARLY WED. FNT CONTS SWRD ON WED AND MAY TRIGGER SOME
AFTN CONV OVER THE CNTRL AND SRN SITES LDG TO BRIEF REDUCTIONS IN
CIG AND VSBYS. DRIER AIR BHD THE FNT WILL MAINTAIN VFR CONDS THRU
THE END OF THE TAF PD.
OUTLOOK...
THU/FRI/SAT...VFR...EXCEPT FOR POSSIBLE IFR EARLY MORNING VALLEY
FOG...MAINLY KELM.
SUN...VFR...CHC MVFR IN SHWR/TSTM AFTERNOON.
&&
.CLIMATE...
SYRACUSE SHATTERED DAILY RECORD OF 94 DEGREES...BY HITTING AT
LEAST 100 DEGREES AS OF 3 PM...ONLY A COUPLE DEGREES AWAY FROM ALL
TIME RECORD OF 102 SET JULY 9 1936. BINGHAMTON AIRPORT IS
CURRENTLY TIED WITH THE DAILY RECORD AS OF 320 PM /91 DEGREES/.
DAILY RECORD FOR AVOCA IS 96 DEGREES...WHICH WILL BE A CLOSE CALL.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/MLJ/MDP
SHORT TERM...MDP
LONG TERM...BMW
AVIATION...DGM/DJN
CLIMATE...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
105 AM EDT WED JUL 18 2012
.SYNOPSIS...
AFTER A DAY OF RECORD OR NEAR RECORD HEAT...A COLD FRONT WILL SLIP
SOUTH TO TRIGGER SCATTERED THUNDERSTORMS ACROSS PORTIONS OF CENTRAL
NEW YORK TONIGHT...MAINLY ALONG THE NEW YORK THRUWAY REGION...SOME
OF WHICH COULD BE SEVERE. THE FRONT WILL CONTINUE TO PUSH SOUTH
FOR ADDITIONAL POSSIBLE SEVERE THUNDERSTORMS FOR MAINLY SOUTHERN
NEW YORK AND NORTHEAST PENNSYLVANIA WEDNESDAY. COOLER AND DRIER
AIR WILL BUILD IN BEHIND THE FRONT THURSDAY AND FRIDAY...FOLLOWED
BY WARMING TEMPERATURES OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1 AM UPDATE...
04Z SUBJECTIVE SURFACE ANALYSIS PLACES MAIN COLD FRONT ALONG A
HAMILTON, ON...TO TRENTON, ON...TO WATERTOWN LINE. AHEAD OF THIS
BOUNDARY OVERALL CONVECTIVE ACTIVITY HAS SHOWN A NOTICEABLE
WEAKENING TREND IN RECENT HRS AS MAIN MID-LEVEL FORCING REMAINS
WELL NORTH OF THE FCST AREA. EARLIER...RADAR TRENDS SHOWED RENEWED
CONVECTION JUST NORTH OF THE LAKE ONTARIO SHORE...HOWEVER NO NEW
DEVELOPMENT IS APPARENT WITHIN THE LAST HR OR SO. REGIONAL HIGH-
RES CONVECTION ALLOWING MODELS SUGGEST A CONTINUED WEAKENING TREND
OVERNIGHT AS MAIN COLD FRONT CONTINUES TO OUTRUN ANY MID-LEVEL
SUPPORT WHICH SHOULD JUST SKIRT NORTHERN PORTIONS OF OUR FCST
AREA. IN FACT...LATEST WATER VAPOR IMAGERY SHOWS A NICE SHORTWAVE
TROUGH LOCATED JUST NORTH OF LAKE HURON...WHICH IS JUST A BIT TOO
FAR NORTH TO HAVE ANY APPRECIABLE AFFECT ON CONVECTIVE TRENDS
ACROSS OUR REGION. THAT SAID...CONSIDERING RECENT RADAR TRENDS AND
GUIDANCE FROM REGIONAL HIGH-RES MODELS TO INCLUDE THE HRRR AND
WRF-ARW...HAVE ELECTED TO LOWER POPS FOR THE REMAINDER OF THE
MORNING HRS AS NOCTURNAL STABILIZATION PROCESSES CONTINUE. DESPITE
THIS...EXPECT THE FRONT TO GRADUALLY SINK THROUGH THE FINGER LAKES
INTO THE SOUTHERN TIER BY MORNING. AFTER 12Z...CONVECTION WILL
ONCE AGAIN DEVELOP ALONG THE BOUNDARY AS DAYTIME HEATING ONCE
AGAIN COMMENCES. WILL FURTHER INVESTIGATE SEVERE POTENTIAL PRIOR
TO THE NEXT UPDATE HOWEVER INITIAL IMPRESSIONS SUGGEST BEST
FORCING WILL AGAIN REMAIN NORTH OF THE AREA WHICH MAY INHIBIT
WIDESPREAD SEVERE COVERAGE.
10 PM UPDATE... CONVECTIVE COVERAGE HAS INCREASED A BIT SINCE
EARLIER THIS EVE ACRS UPSTATE NY...JUST S OF THE SFC FRNT...AND
ALG THE LEADING EDGE OF THE BETTER INSTAB (ML CAPES OF 1000-2000
ATTM STILL OVER MOST OF THE CWA). HOWEVER...THE STGR STORMS/DEEPER
CORES SEEM TO BE CLOSELY TIED TO A CONVERGENCE BNDRY NEAR THE S SHORE OF
LK ONT...WITH A GENERAL WEAKENING TREND NOTED SO FAR ONCE THEY
PUSH FARTHER INLAND.
AS THE SFC FRNT CONTS GRADUALLY SWD OVERNIGHT AND A WELL DEFINED
UPR-LVL WAVE COMES ACRS LK HURON/SRN ONT/FAR NRN NY...WE THINK AN
AREA OF SHRA/TSRA WILL SLOWLY PENETRATE FARTHER SWD ACRS CNY...AND
PERHAPS THE FAR NRN TIER OF PA TWDS DAYBREAK. IN
GENERAL...COVERAGE SHOULD LESSEN WITH SWD EXTENT...AS THE STORMS
OUTRUN THE BETTER FORCED ASCENT AND MORE PRONOUNCED DEEP-LYRD
SHEAR OFF TO THE N. OVERALL...THE SVR THREAT SEEMS MARGINAL...BUT
AN ISOLD STG/SVR STORM CAN`T BE RULED OUT...AND WE`LL CONTINUE TO
MONITOR DEVELOPMENTS.
PREV DISC... 7 PM UPDATE... CONDS REMAIN VERY QUIET ATTM
THROUGHOUT CNY/NE PA. THE AMS IS MODERATELY UNSTABLE (ML CAPES OF
1000-2000...AND LOCALLY HIGHER)...BUT LARGE-SCALE SUPPORT IS
LACKING. ACTIVE CONVECTION REMAINS CONFINED MUCH CLOSER TO THE SFC
FRNTL BNDRY...AND ALSO FORCING FROM A SERIES OF UPR-LVL
WAVES...FROM WI/NRN MI EWD THROUGH SRN ONT AND FAR UPSTATE NY.
AS THE NGT PROGRESSES...WE STILL EXPECT THAT THE SFC FRNT WILL CONTINUE
ITS SLOW SWD PUSH...AND ALSO THAT A WELL DEFINED UPR-LVL PV LOBE
WILL TRACK ESEWD FROM THE NRN LKS RGN TWDS UPSTATE NY AFTER 06Z.
ALTHOUGH AVAILABLE INSTABILITY SHOULD BE SOMEWHAT LESS BY
THEN...THERE WILL LIKELY BE ENOUGH OF IT (ML CAPES STILL NEAR OR
ABV 1000) TO INITIATE SOMEWHAT BETTER COVERAGE OF
SHRA/TSRA...GIVEN IMPROVED LIFT FROM JUST MENTIONED SYSTEMS.
POP/WX GRIDS WERE TWEAKED TO INDICATE ONLY ISOLD COVERAGE IN THE
FAR N THROUGH MUCH OF THE EVE (03-06Z)...WITH SCTD CONVECTION
COMING IN FROM WNW TO ESE IN THE 06-10Z TIME FRAME. OVERALL...WE
FEEL THE SVR THREAT IS SOMEWHAT LIMITED...BUT COMBINATION OF
LINGERING INSTAB...IMPROVING DEEP-LYRD SHEAR (0-6 KM VALUES OF
30-40 KT)...AND BETTER FORCED ASCENT COULD CONCEIVABLY TRIGGER A
FEW STG/SVR STORMS LATER TNT. WE`LL CONTINUE TO MONITOR.
JUST MINOR CHGS MADE TO NEAR-TERM TEMP/DEW PT GRIDS EARLY THIS EVE.
EARLIER DISC... 300 PM UPDATE... SEVERE THUNDERSTORM WATCH REMAINS IN
EFFECT UNTIL 9 PM FOR ONEIDA COUNTY...THOUGH IT WILL TAKE UNTIL
NEAR THE END OF THAT WATCH /PERHAPS EVEN AFTER/ FOR THE THREAT TO
PEAK. HEAT ADVISORY ALSO REMAINS IN EFFECT FOR THE LAKE PLAIN TO
MOHAWK VALLEY WHERE HEAT INDICES ARE NEAR OR SLIGHTLY ABOVE 100
DEGREES. ACTUAL TEMPERATURE IN SYRACUSE WITH DOWNSLOPING MANAGED
TO HIT 100 DEGREES SO FAR...EASILY SHATTERING THE DAILY
RECORD...AND GETTING ONLY 2 DEGREES FROM THE ALL TIME RECORD OF
102 SET JULY 9 1936.
FORECAST UPDATED FOR ANTICIPATED EVOLUTION OF CONVECTIVE
DEVELOPMENT...ESPECIALLY NY THRUWAY REGION...THOUGH DELAYED BY A
COUPLE HOURS DEEPER INTO THE EVENING FOR PEAK CHANCES. SURFACE
FRONT EXTENDS ROUGHLY ALONG THE ST. LAWRENCE VALLEY...THROUGH
ONTARIO /JUST NORTH OF LAKE ONTARIO/...BACK TO LAKE HURON AND
CENTRAL LOWER MICHIGAN. IT IS SET TO SAG SLOWLY SOUTH THROUGH
THE AREA LATE THIS EVENING THROUGH MIDDAY WEDNESDAY. SOUTH OF THE
FRONT...ATMOSPHERE WILL BE VERY WARM NOT JUST AT THE SURFACE BUT ALSO
MID LEVELS...INCLUDING 850 MB AT LEAST 23 DEG CELSIUS. THIS MID LEVEL
FOR NOW IS KEEPING CONVECTIVE INHIBITION OVER THE AREA. LATE EVENING
INTO TONIGHT...WE LOSE DIURNAL HEATING BUT CONDITIONS ALOFT BECOME
MORE FAVORABLE WITH WINDS AT UPPER LEVELS GOING FROM CONVERGENT TO
MORE NEUTRAL...AND MID LEVEL LAPSE RATES INCREASE. THE BIG QUESTION IS
WHETHER CONVECTION CAN INITIATE UPSTREAM /PERHAPS FROM THE WAVE
NOW IN UPPER WISCONSIN-NORTHERN MICHIGAN/...AND HOW FAR WILL IT
CARRY THROUGH THE AREA. THE ONE CERTAINTY HERE...IS THAT WITH
INVERTED-V IN THE LOW LEVELS...AND 35-50 KT OF SHEAR THROUGHOUT
THE 2KM-6KM LAYER...CONVECTION WILL BE CAPABLE OF STRONG
WINDS...WHILE LARGE HAIL AND ISOLATED TORNADOES ARE NOT AS LIKELY
BUT ALSO NOT OUT OF THE QUESTION.
BEST CHANCES WILL BE LATE THIS EVENING ACROSS THE NORTHERN
ZONES...ESPECIALLY ALONG AXIS OF THE NEW YORK THRUWAY...AND
PERHAPS EDGING FARTHER SOUTH TO AT LEAST FINGER LAKES-CATSKILLS
AXIS OVERNIGHT AS IT DIMINISHES WITH DECREASING INSTABILITY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
315 PM UPDATE...
STORM PREDICTION CENTER PLACES SOUTHERN TIER/CATSKILLS AND
NORTHEAST PENNSYLVANIA IN SLIGHT RISK FOR SEVERE WEATHER...WITH 30
PCT DAMAGING WIND RISK CONTOUR INCLUDING MUCH OF NORTHEAST PA.
UPPER DIVERGENCE COINCIDES WITH FRONTAL PASSAGE IN THE MORNING
HOURS...YET LOW LEVEL CONVERGENCE AND DIURNAL HEATING PEAK AS THE
FRONT IS HEADING OUT OF THE AREA. SHEAR IS NOT AS STRONG
WEDNESDAY...AS COMPARED TO THIS AFTERNOON/TONIGHT...BUT OVERALL
LOOKING QUITE ACTIVE FOR THE SOUTHERN HALF OF THE AREA LATE
MORNING INTO EARLY AFTERNOON. ALSO EXPECTING EARLIER INITIATION OF
CONVECTION BECAUSE OF FAVORABLE UPPER LEVEL SUPPORT.
LOWER ELEVATIONS IN THE SOUTHERN ZONES COULD STILL MANAGE 90
DEGREES WITH UNCOMFORTABLE UPPER 60S/NEAR 70 DEW POINTS...BUT
OTHERWISE TURNING COOLER CENTRAL AND NORTH...AS FRONT CONTINUES
TO SLIDE SOUTH...AND DEW POINTS DROP. ANY LINGERING CONVECTION
WEDNESDAY EVENING QUICKLY SHIFTS SOUTH. LOWS IN UPPER 50S NORTH TO
MID-UPPER 60S SOUTH BY DAWN THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
1 PM UPDATE...
COLD FRONT PUSHES SOUTHEAST THROUGH PA AND NJ THURSDAY WITH SURFACE
HIGH PRESSURE BUILDING INTO NY. UPPER LEVEL TROUGH IS OVER NEW
ENGLAND AND PULLING AWAY TO THE NORTHEAST. BY MIDDAY FRI A
SHORT-WAVE APPROACHES AND MAY HELP TO TRIGGER SOME SHOWERS ACROSS
THE POCONO AREA AND WYOMING VALLEY. WEAK RIDGING DURING THE DAY
SATURDAY WITH FAIR SKIES AND HIGHS IN THE MID 80S. WARM FRONT MOVES
THROUGH SATURDAY NIGHT WITH BRINGING SOME CLOUDS AND A CHANCE OF
TSTMS EAST OF LAKE ONTARIO INTO ONEIDA COUNTY. SUNDAY A COLD FRONT
AND UPPER LEVEL TROUGH APPROACH BRINGING A CHANCE FOR SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON INTO MONDAY AS A WEAK COLD FRONT
MOVES SOUTHEAST ACROSS THE REGION. HIGH PRESSURE BUILDS IN TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VIS SATL IMAGERY SHOWS VFR ACROSS ALL TAF SITES WITH SCT-BKN MID
TO HIGH CLDS ACRS KSYR AND KRME. THERE WERE A FEW CU FADING AWAY
ACROSS OF THE REST OF C NY AND NE PA. FOR THE NEXT 6
HOURS...EXPECT SCT TSRA TO WORK SOUTHWARD AND BE AROUND KSYR 4-6Z
AND KRME 5-7Z. MOST OF THE DEEPEST CONVECTION WAS EAST AND NORTH
OF KRME AND KSYR. LATER TONIGHT MORE SCT TSRA CUD REACH INTO C NY
WELL AFTER MIDNIGHT BUT UNSURE ABOVE COVERAGE AND PROBABILITIES SO
LEFT OUT OF KITH...KBGM AND KELM TAFS. FOR KAVP VERY SMALL CHANCES
OF CONVECTION OVERNIGHT.
A FRONT WILL DROP SOUTH AND CROSS KRME...AND KSYR. THERE IS A
CHANCE OF A ST/SC LAYER BEHIND THIS FRONT WHICH CUD BE MVFR OR
JUST ABV MVFR. FOR NOW WENT 3500 FEET CIGS. THESE CLDS SHUD MIX
OUT PRETTY QUICKLY AND THE REST OF THE PD SHUD BE VFR WITH ONLY A
FEW CU AND MAYBE SOME CI IN THESE AREAS.
FARTHER SOUTH...CD FRNT MOVING SOUTH WILL DEVELOP MORE CONVECTION WITH A
CHC FOR MVFR VSBY WED PM FROM TSRA. BELIEVE CONVECTION WILL INITIATE
ARND KITH AND GROW AND BECOME MORE WIDESPREAD AS IT TRACKS
SOUTHWARD. WENT FOR PROB30 TSRA MVFR AT KITH...KBGM...KELM AND
KAVP AT THIS TIME. TIMING 16-20Z KITH...18-22Z KBGM AND KELM AND
20-24Z AT KAVP. A LOT OF UNCERTAINTIES EXIST AS TO INTENSITY...FLIGHT
CATEGORY AND TIMING SO PLAYED IT AS PROB30 AND MVFR FOR NOW. LATER
SHIFTS CAN REFINE.
WINDS WERE PRESENTLY GUSTY SW 10-20KT WHICH SHUD SUBSIDE AFTER
SUNSET. THEN WINDS WILL SHIFT TO THE N-NW AT KSYR...KRME AND KITH
WED AM AND BY WED PM FARTHER SOUTH.
OUTLOOK...
WED NGT...POSSIBLE MVFR/IFR RESTRICTIONS FROM FOG.
THU/FRI/SAT...VFR...EXCEPT FOR POSSIBLE IFR EARLY MORNING VALLEY
FOG...MAINLY KELM.
SUN...VFR...CHC MVFR IN SHWR/TSTM AFTERNOON.
&&
.CLIMATE...
SYRACUSE SHATTERED DAILY RECORD OF 94 DEGREES...BY HITTING AT
LEAST 100 DEGREES AS OF 3 PM...ONLY A COUPLE DEGREES AWAY FROM ALL
TIME RECORD OF 102 SET JULY 9 1936. BINGHAMTON AIRPORT IS
CURRENTLY TIED WITH THE DAILY RECORD AS OF 320 PM /91 DEGREES/.
DAILY RECORD FOR AVOCA IS 96 DEGREES...WHICH WILL BE A CLOSE CALL.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...CMG/MLJ/MDP
SHORT TERM...MDP
LONG TERM...BMW
AVIATION...DJN
CLIMATE...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
429 AM CDT WED JUL 18 2012
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
FORECAST HIGHLIGHTS WILL BE HOT AND HUMID CONDITIONS THROUGH THE
PERIOD ALONG WITH CHANCES FOR THUNDERSTORMS. WILL USE AN OVERALL
BLEND.
CURRENTLY...MID LEVEL S/WV TROUGH LIFTING EAST-NORTHEAST ACROSS THE
NORTHERN PLAINS. A BLEND OF THE 00Z GFS AND 05Z HRRR SEEMS TO
CAPTURE REALITY THE BEST WITH OTHER MODELS JUNK. BASED ON THE HRRR
OUTPUT AND LATEST RADAR IMAGERY...WILL MAINTAIN HIGHER POPS WEST
INTO NORTH CENTRAL NEAR THE TRACK OF THE WAVE...AND OVER MY FAR
SOUTHEAST WITH ADDITIONAL STRONG THUNDERSTORMS DEVELOPING INTO
NORTHEAST SOUTH DAKOTA ALONG A SFC TROUGH AXIS. ELSEWHERE OPTED TO
KEEP AT LEAST A SLIGHT CHANCE FOR THUNDER WITH PLENTY OF INSTABILITY
PRESENT ALONG WITH THE WAVE PASSAGE. WHILE THE OVERALL THREAT FOR
SEVERE STORMS THIS MORNING IS LOW...NOT ENTIRELY OUT OF THE
QUESTION. MOST STORMS SHOULD BE HEAVY RAINERS THOUGH WITH PWATS
STILL AT OR ABOVE 1.5 INCHES.
AFTER 12Z MODELS HAVE PRECIPITATION ENDING FROM WEST TO EAST AS THE
S/WV PUSHES FARTHER EAST AND AS A RIDGE OF HIGH PRESSURE BUILDS IN
ACROSS THE WEST. FOR THE 12-18Z PERIOD...WILL KEEP HIGHER POPS NORTH
CENTRAL AND EAST WITH LOWER POPS WEST FOR ANY LINGERING CONVECTION.
MODELS HINT AT AFTERNOON THUNDERSTORMS DEVELOPING EAST OF HIGHWAY 83
SO WILL MAINTAIN CHANCE POPS. MID LEVEL FORCING PRETTY MUCH
NONEXISTENT SO THINKING IS THE THREAT FOR ORGANIZED CONVECTION WILL
BE LOW TODAY AND MAINLY DIURNAL. LITTLE ACTIVITY EARLY TO MID
EVENING WITH THE RIDGE ALOFT SO WILL KEEP THINGS DRY. TEMPERATURES
MUCH WARMER TODAY AS WE SHOULD SEE PLENTY OF SUNSHINE ALONG WITH WAA
AHEAD OF THE RIDGE.
BOTH THE NAM AND GFS INDICATE A LOW LEVEL JET DEVELOPING LATE
TONIGHT WEST INTO NORTH CENTRAL WITH THE WARM FRONT ADVANCING EAST.
WITH THE WAA WILL SEE INCREASING ELEVATED INSTABILITY AS WELL. WHILE
ALL OTHER GUIDANCE IS DRY...THE NAM DOES PAINT SOME QPF IN THIS AREA
SO OPTED TO THROW IN A SLIGHT CHANCE OF THUNDER 06-12Z LATE
TONIGHT/EARLY THURSDAY MORNING.
LOTS OF UNCERTAINTY REGARDING THUNDERSTORM CHANCES THURSDAY AND
THURSDAY NIGHT. PLENTY OF UNSTABLE AIR ALONG WITH A WEAK AREA OF LOW
PRESSURE ACROSS THE LOCAL AREA. MID LEVEL FORCING QUESTIONABLE WITH
THE UPPER LEVEL RIDGE ALOFT. ANY RIDGE RIDER WAVE WOULD BE
SUFFICIENT TO TRIGGER STORMS. WILL KEEP A SLIGHT CHANCE ALL
LOCATIONS FOR THIS TIMEFRAME FOR NOW. VERY HOT AND HUMID THURSDAY
AFTERNOON BEHIND THE WARM FRONT. WHILE 100 DEGREES IS IN THE
FORECAST WEST AND FAR SOUTH CENTRAL...MODELS ARE TRYING TO BRING IN
DRIER AIR IN THE FORM OF DEWPOINTS IN THE 50S. THIS WOULD ACTUALLY
KNOCK DOWN THE HEAT INDEX TO SUB-HEAT ADVISORY LEVELS BELOW 100.
WILL CONTINUE TO MONITOR.
.LONG TERM...FRIDAY THROUGH TUESDAY...
ABOVE NORMAL TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH THE
EXTENDED.
THE MAIN FEATURE THIS EXTENDED PERIOD IS A BROAD RIDGE ACROSS THE
CENTRAL AND NORTHERN PLAINS THAT WILL REMAIN IN PLACE THROUGH THE
WEEKEND. SEVERAL SHORT WAVE TROUGHS MOVE ACROSS THE TOP OF THE RIDGE
KEEPING THE WEATHER ACTIVE THOUGH THE WEEKEND. BY EARLY NEXT WEEK
THE RIDGE BEGINS TO FLATTEN AS MORE SIGNIFICANT SHORTWAVE ENERGY
ENTERING THE NORTHWEST US BEGINS TO MOVE EAST. THE EUROPEAN IS
FASTER THAN THE GFS ON THIS SHORTWAVE BY TUESDAY...BUT NEVERTHELESS
THERE SHOULD BE AN ACTIVE WEATHER PATTERN EXTENDING INTO NEXT WEEK.
ON FRIDAY...THE GFS/NAM BOTH BRING IN A BACKDOOR COLD FRONT
ASSOCIATED WITH A CANADIAN RIDGE RIDER...WHICH WILL MAKE HIGH
TEMPERATURES A BIT TRICKY ON FRIDAY...AND FRIDAY NOW LOOKS A BIT
COOLER THAN THURSDAY DOES....ESPECIALLY NORTH. THE FRONTAL BOUNDARY
ALSO WILL BE THE FOCUS FOR THUNDERSTORMS...MAINLY FRIDAY NIGHT INTO
SATURDAY.
&&
.AVIATION...
AT 4 AM CDT...FROM THE 06Z ISSUANCE
A SURFACE FRONTAL BOUNDARY EXTENDED FROM CENTRAL MONTANA TO
NORTHEAST WYOMING...INTO A LOW IN EASTERN SOUTH DAKOTA. SHOWERS AND
THUNDERSTORMS CONTINUE ACROSS WEST AND CENTRAL NORTH DAKOTA EARLY
WEDNESDAY MORNING...IMPACTING KBIS/KISN/KMOT. AFTER 15Z EXPECT THE
NIGHTTIME THUNDERSTORMS TO DISSIPATE LEAVING VFR CONDITIONS AT ALL
TAF SITES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NH
LONG TERM/AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
128 AM CDT WED JUL 18 2012
.DISCUSSION...
MID LEVEL S/WV TROUGH NOW LIFTING INTO WESTERN NORTH DAKOTA.
LEANED ON THE HRRR MODEL FOR THIS UPDATE WITH IT BEING THE ONLY
MODEL CAPTURING REALITY AT THIS TIME. BASED ON THE HRRR OUTPUT AND
LATEST RADAR IMAGERY...THIS LED ME TO GO LIKELY POPS THROUGH 09Z
FAR WEST WITH THE LINE OF CONVECTION NOW MOVING INTO WESTERN NORTH
DAKOTA. AFTER 09Z THUNDERSTORMS ARE EXPECTED TO BE MORE
CONCENTRATED OVER MY NORTH CLOSER TO THE BEST FORCING OF THE MID
LEVEL WAVE. WILL GO WITH A 50 POP HERE FOR NOW 09-18Z. ADDITIONAL
THUNDERSTORMS DEVELOPING OVER SOUTH DAKOTA ALONG A SFC TROUGH
AXIS. A FEW OF THESE STORMS COULD IMPACT MY FAR SOUTHEAST SO
INCREASED POPS HERE. ELSEWHERE OPTED TO KEEP A SLIGHT CHANCE FOR
THUNDER IN WITH PLENTY OF INSTABILITY PRESENT ALONG WITH THE WAVE
PASSAGE.
MODELS HINT AT AFTERNOON THUNDERSTORMS EAST OF HIGHWAY 83...WITH
LITTLE ACTIVITY AFTER 00Z. PREVIOUS FORECAST LOOKS GOOD WITH THIS
SO ONLY MINOR EDITS WERE MADE.
BOTH THE NAM AND GFS INDICATE A LLJ DEVELOPING LATE TONIGHT WEST
INTO NORTH CENTRAL. WHILE ALL OTHER GUIDANCE IS DRY...THE NAM DOES
PAINT SOME QPF IN THIS AREA. OPTED TO THROW IN A SLIGHT CHANCE OF
THUNDER 06-12Z WED NIGHT/EARLY THURSDAY MORNING.
&&
.AVIATION...18/06Z ISSUANCE...
SHOWERS AND THUNDERSTORMS WILL LIKELY IMPACT ALL TAF SITES BUT
POSSIBLY KJMS OVERNIGHT. BASED ON UPSTREAM OBS...HAVE INCLUDED A
TEMPO FOR GUSTY WINDS AND REDUCED VSBY IN TSRA AT KISN FROM 06Z-08Z.
MVFR TO POSSIBLY IFR FOG ALSO EXPECTED AFTER THE STORMS MOVE
THROUGH...MAINLY AT KBIS/KDIK/KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
AVIATION...RK
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1143 PM CDT TUE JUL 17 2012
.AVIATION...
VFR CONDITIONS NEXT 24 HOURS AS HIGH PRESSURE MOVES INTO THE
REGION. THERE IS A LOW RISK OF TSRA AT KLBB THIS MORNING AS A
COMPLEX ACROSS NORTHEASTERN NEW MEXICO EDGES SOUTHWARD.
&&
.PREV DISCUSSION... /ISSUED 1129 PM CDT TUE JUL 17 2012/
UPDATE...
SMALL CLUSTER OF STORMS...FROM NEAR SAN JON TO BROADVIEW TO
GLENRIO...CONTINUES TO PROPAGATE SOUTHWARD...AND NOW APPEARS IT
MAY PERSIST INTO THE FAR NORTHWESTERN ZONES. THUS...HAVE REFINED
POPS SLIGHTLY AND EXTENDED BEYOND 06Z ACROSS THE FAR NORTHWESTERN
ZONES. REMAINDER OF THE FORECAST REMAINS ON TRACK AND HAS BEEN
MAINTAINED.
PREV DISCUSSION... /ISSUED 336 PM CDT TUE JUL 17 2012/
SHORT TERM...
PRECIPITATION THIS MORNING WAS NOT AS EXTENSIVE AS YESTERDAY AND WAS
ALSO LIMITED TO NEAR THE TX/NM STATE LINE. 12Z MODELS WERE NOT
GENERATING MUCH PRECIPITATION AS WELL WITH THE NAM BEING THE ONLY
MODEL WITH POPS OVER PORTIONS OF THE FORECAST AREA. HRRR RUNS THROUGH
14Z WERE ALSO NOT BREAKING OUT PRECIPITATION OVER THE REGION BUT THE
LATEST RUNS SINCE 15Z ARE SHOWING SOME CONVECTION OVER THE ROLLING
PLAINS WHILE LEAVING THE SOUTH PLAINS HIGH AND DRY. HARD TO TELL
HOW THINGS WILL PLAY OUT AS WV SATELLITE LOOP SHOWS DRIER AIR
PUSHING INTO THE REGION ALOFT AND MODELS INDICATE CAP HAS
STRENGTHENED JUST A BIT AS WELL. WILL KEEP BEST CHANCES FOR PRECIP
TONIGHT NEAR THE STATE LINE WHICH IS CLOSER TO THE MID-LEVEL
MOISTURE AXIS AND BETTER LAPSE RATES. ONE OTHER ISSUE IS THE
UPPER-LEVEL LOW WHICH IS STARTING TO SLOWLY DRIFT TO THE NORTHWEST
OVER THE LAST COUPLE OF HOURS. DEPENDING ON HOW CLOSE THIS GETS TO
THE REGION...THIS MAY HELP INITIATE A FEW STORMS LATER THIS
EVENING. AS A RESULT...WILL KEEP MENTION OF ISOLATED POPS OVER THE
ROLLING PLAINS AND THE EASTERN/CENTRAL SOUTH PLAINS THROUGH THE
NIGHT. WITH THE UPPER LOW MOVING WEST AND THE RIDGE PUSHING BACK
OVER THE AREA...POP CHANCES DECREASE TOMORROW EVEN MORE WITH
TEMPERATURES A FEW DEGREES WARMER THAN TODAY.
JORDAN
LONG TERM...
UA RIDGE WILL COMMENCE TO BUILD ACROSS THE CENTRAL PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING...WHERE THE MONSOONAL MOISTURE PLUME WILL BE
CAPABLE OF BENDING EASTWARD TOWARDS THE SOUTHWESTERN TEXAS PANHANDLE
AND FAR WESTERN SOUTH PLAINS. LATEST MODEL RUNS HAVE BACKED OFF ON
SHOWING PRECIP DEVELOPING ACROSS THE AFOREMENTIONED AREAS...AS IT
GETS SHUNTED WESTWARD QUICKER THAN PREVIOUS RUNS. MID-LEVEL
INSTABILITY DROP TO 50-100 J/KG AND PWATS ALSO DECLINE TO AOA 1.00
INCH. WILL GO AHEAD AND MAINTAIN POPS TO JUST WEST OF THE TEXAS
STATE LINE. THEREAFTER...THE UA RIDGE ACROSS THE CENTRAL PLAINS WILL
BE THE DOMINATE SYNOPTIC FEATURE FOR THE SOUTHERN PLAINS...AS SLOWLY
INCREASING HEIGHT FIELDS WILL PROMOTE TEMPS TO WARM ABOVE SEASONAL
NORMS BY THE WEEKEND /MID 90S ON THE CAPROCK TO TRIPLE DIGITS OFF
THE CAPROCK/....AND LARGE SCALE SUBSIDENCE WILL MITIGATE STORM
POTENTIAL. THEREAFTER...BOTH THE GFS AND ECMWF HINT AT THE CENTER OF
THE UA RIDGE TRANSLATING EAST TOWARDS THE CENTRAL MISSISSIPPI VALLEY
EARLY NEXT WEEK. AN EASTERLY WAVE IS EXHIBITED BRUSHING ACROSS THE
SOUTHERN LOCALES ON TUESDAY. THE SAID MODELS ARE VOID OF
PRECIP...GIVEN THIS WEAKNESS IS DISPLAYED TO BE RELATIVELY WEAK.
WILL NEED TO KEEP AN EYE ON HOW THE SYNOPTIC PATTERN EVOLVES AND
WHETHER OR NOT THIS EASTERLY WAVE WILL INDEED PROVE TO BE
INCONSEQUENTIAL FOR THE SOUTHERN PLAINS...OR TURN OUT TO BE A
SYNOPTIC SPARK FOR CI.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 62 93 64 92 65 / 20 10 10 10 10
TULIA 64 94 66 93 67 / 10 10 10 10 10
PLAINVIEW 67 94 67 92 68 / 10 10 10 0 0
LEVELLAND 65 94 67 93 67 / 10 10 10 0 0
LUBBOCK 69 95 68 94 69 / 10 10 10 0 0
DENVER CITY 64 93 67 92 66 / 10 10 10 10 10
BROWNFIELD 65 93 67 92 67 / 10 10 10 0 0
CHILDRESS 70 99 72 99 73 / 10 10 10 0 0
SPUR 66 96 69 95 70 / 10 10 10 0 0
ASPERMONT 71 99 72 98 72 / 10 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/26
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1129 PM CDT TUE JUL 17 2012
.UPDATE...
SMALL CLUSTER OF STORMS...FROM NEAR SAN JON TO BROADVIEW TO
GLENRIO...CONTINUES TO PROPAGATE SOUTHWARD...AND NOW APPEARS IT
MAY PERSIST INTO THE FAR NORTHWESTERN ZONES. THUS...HAVE REFINED
POPS SLIGHTLY AND EXTENDED BEYOND 06Z ACROSS THE FAR NORTHWESTERN
ZONES. REMAINDER OF THE FORECAST REMAINS ON TRACK AND HAS BEEN
MAINTAINED.
&&
.PREV DISCUSSION... /ISSUED 826 PM CDT TUE JUL 17 2012/
UPDATE...
DRY...SINKING AIR ALOFT ROTATING AROUND THE UPPER LOW TO OUR
SOUTH AND ATOP THE SOUTH PLAINS HAS PROVEN TOO MUCH TO SUPPORT
CONVECTIVE INITIATION LOCALLY THIS AFTERNOON OR EARLY THIS
EVENING. HENCE...HAVE REMOVED THE LOW THUNDER MENTION FOR MOST OF
THE CENTRAL AND EASTERN ZONES FOR THE REMAINDER OF THE NIGHT.
HOWEVER...A SMALL CLUSTER OF STORMS HAS ORGANIZED FROM NORTHEAST
NEW MEXICO INTO THE WEST-CENTRAL TEXAS PANHANDLE AND THIS ACTIVITY
WAS SAGGING SLOWLY SOUTHWARD AND COULD POTENTIALLY AFFECT THE
NORTHWEST LATER TONIGHT...IF IT CAN HOLD TOGETHER. THUS...HAVE
MAINTAINED A SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE NORTHWEST
ZONES. OTHERWISE...HAVE MADE A FEW OTHER MINOR ADJUSTMENTS TO THE
SHORT TERM GRIDS TO BETTER REFLECT THE MOST RECENT OBSERVATIONS
AND EXPECTED TRENDS. UPDATED PRODUCTS HAVE BEEN SENT.
PREV DISCUSSION... /ISSUED 637 PM CDT TUE JUL 17 2012/
AVIATION...
VFR ENTIRE CYCLE AT BOTH KLBB AND KCDS. CHANCE OF A ROGUE TS
TOO LOW TO MENTION ATTM.
PREV DISCUSSION... /ISSUED 336 PM CDT TUE JUL 17 2012/
SHORT TERM...
PRECIPITATION THIS MORNING WAS NOT AS EXTENSIVE AS YESTERDAY AND WAS
ALSO LIMITED TO NEAR THE TX/NM STATE LINE. 12Z MODELS WERE NOT
GENERATING MUCH PRECIPITATION AS WELL WITH THE NAM BEING THE ONLY
MODEL WITH POPS OVER PORTIONS OF THE FORECAST AREA. HRRR RUNS THROUGH
14Z WERE ALSO NOT BREAKING OUT PRECIPITATION OVER THE REGION BUT THE
LATEST RUNS SINCE 15Z ARE SHOWING SOME CONVECTION OVER THE ROLLING
PLAINS WHILE LEAVING THE SOUTH PLAINS HIGH AND DRY. HARD TO TELL
HOW THINGS WILL PLAY OUT AS WV SATELLITE LOOP SHOWS DRIER AIR
PUSHING INTO THE REGION ALOFT AND MODELS INDICATE CAP HAS
STRENGTHENED JUST A BIT AS WELL. WILL KEEP BEST CHANCES FOR PRECIP
TONIGHT NEAR THE STATE LINE WHICH IS CLOSER TO THE MID-LEVEL
MOISTURE AXIS AND BETTER LAPSE RATES. ONE OTHER ISSUE IS THE
UPPER-LEVEL LOW WHICH IS STARTING TO SLOWLY DRIFT TO THE NORTHWEST
OVER THE LAST COUPLE OF HOURS. DEPENDING ON HOW CLOSE THIS GETS TO
THE REGION...THIS MAY HELP INITIATE A FEW STORMS LATER THIS
EVENING. AS A RESULT...WILL KEEP MENTION OF ISOLATED POPS OVER THE
ROLLING PLAINS AND THE EASTERN/CENTRAL SOUTH PLAINS THROUGH THE
NIGHT. WITH THE UPPER LOW MOVING WEST AND THE RIDGE PUSHING BACK
OVER THE AREA...POP CHANCES DECREASE TOMORROW EVEN MORE WITH
TEMPERATURES A FEW DEGREES WARMER THAN TODAY.
JORDAN
LONG TERM...
UA RIDGE WILL COMMENCE TO BUILD ACROSS THE CENTRAL PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING...WHERE THE MONSOONAL MOISTURE PLUME WILL BE
CAPABLE OF BENDING EASTWARD TOWARDS THE SOUTHWESTERN TEXAS PANHANDLE
AND FAR WESTERN SOUTH PLAINS. LATEST MODEL RUNS HAVE BACKED OFF ON
SHOWING PRECIP DEVELOPING ACROSS THE AFOREMENTIONED AREAS...AS IT
GETS SHUNTED WESTWARD QUICKER THAN PREVIOUS RUNS. MID-LEVEL
INSTABILITY DROP TO 50-100 J/KG AND PWATS ALSO DECLINE TO AOA 1.00
INCH. WILL GO AHEAD AND MAINTAIN POPS TO JUST WEST OF THE TEXAS
STATE LINE. THEREAFTER...THE UA RIDGE ACROSS THE CENTRAL PLAINS WILL
BE THE DOMINATE SYNOPTIC FEATURE FOR THE SOUTHERN PLAINS...AS SLOWLY
INCREASING HEIGHT FIELDS WILL PROMOTE TEMPS TO WARM ABOVE SEASONAL
NORMS BY THE WEEKEND /MID 90S ON THE CAPROCK TO TRIPLE DIGITS OFF
THE CAPROCK/....AND LARGE SCALE SUBSIDENCE WILL MITIGATE STORM
POTENTIAL. THEREAFTER...BOTH THE GFS AND ECMWF HINT AT THE CENTER OF
THE UA RIDGE TRANSLATING EAST TOWARDS THE CENTRAL MISSISSIPPI VALLEY
EARLY NEXT WEEK. AN EASTERLY WAVE IS EXHIBITED BRUSHING ACROSS THE
SOUTHERN LOCALES ON TUESDAY. THE SAID MODELS ARE VOID OF
PRECIP...GIVEN THIS WEAKNESS IS DISPLAYED TO BE RELATIVELY WEAK.
WILL NEED TO KEEP AN EYE ON HOW THE SYNOPTIC PATTERN EVOLVES AND
WHETHER OR NOT THIS EASTERLY WAVE WILL INDEED PROVE TO BE
INCONSEQUENTIAL FOR THE SOUTHERN PLAINS...OR TURN OUT TO BE A
SYNOPTIC SPARK FOR CI.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 62 93 64 92 65 / 20 10 10 10 10
TULIA 64 94 66 93 67 / 10 10 10 10 10
PLAINVIEW 67 94 67 92 68 / 10 10 10 0 0
LEVELLAND 65 94 67 93 67 / 10 10 10 0 0
LUBBOCK 69 95 68 94 69 / 10 10 10 0 0
DENVER CITY 64 93 67 92 66 / 10 10 10 10 10
BROWNFIELD 65 93 67 92 67 / 10 10 10 0 0
CHILDRESS 70 99 72 99 73 / 10 10 10 0 0
SPUR 66 96 69 95 70 / 10 10 10 0 0
ASPERMONT 71 99 72 98 72 / 10 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/23
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1158 PM CDT TUE JUL 17 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE SURFACE
COLD FRONT STRETCHING FROM ABOUT WISCONSIN RAPIDS TO APPLETON TO
KEWAUNEE EARLY THIS AFTERNOON. ELEVATED CONVECTION MOVED INTO N-C
WISCONSIN THIS MORNING IN A REGION OF UPPER DIVERGENCE...MID-LEVEL
FGEN...AND POSSIBLY AHEAD OF A WEAK MCV. ADDITIONAL CONVECTION HAS
JUST RECENTLY DEVELOPMENT IN THE WARM SECTOR OVER CENTRAL AND
EAST-CENTRAL WISCONSIN AND WILL NEED TO WATCH THIS AREA FOR SEVERE
DEVELOPMENT. WITH ML CAPES APPROACHING 2000 J/KG...INHIBITION HAS
BEEN ERODING THIS AFTERNOON AND THINK AN ISOLATED SEVERE STORM
REMAINS POSSIBLE GENERALLY SOUTH OF A MARSHFIELD TO GREEN BAY LINE.
THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. PRECIP
TRENDS THROUGH TONIGHT ARE THE MAIN FORECAST CONCERNS.
TONIGHT...AS THE UPPER FLOW VEERS TO THE NORTHWEST...THE SURFACE
COLD FRONT WILL GET DRIVEN SOUTH FROM CENTRAL WISCONSIN TO NORTHERN
ILLINOIS. THE 850MB FRONT WILL NOT BE SO QUICK AND WILL LINGER
ALONG THE ROUTE 29 CORRIDOR THROUGH THE EVENING BEFORE SHIFTING TO
THE SOUTH. THOUGH UPPER DIVERGENCE PULLS OUT BY THIS
EVENING...850-700MB FGEN WILL LINGER ALONG THE FRONTAL SLOPE AND
THEN PUSH SOUTH LATE TONIGHT. ANY SURFACE BASED STORMS WILL BE
MOVING SOUTH OF THE FORECAST AREA EARLY THIS EVENING...BUT THE
CONVERGENT FLOW AND MID-LEVEL FGEN WILL KEEP SCATTERED POTENTIAL OF
SHOWERS AND STORMS GOING THROUGH THE NIGHT OVER CENTRAL AND
EAST-CENTRAL WISCONSIN. DO THINK STORM COVERAGE AND INTENSITY WILL
DIMINISH WITH LOSS OF HEATING...SO THE POSSIBILITY OF SEVERE
CONVECTION MAY ONLY OCCUR UNTIL EARLY THIS EVENING. COOLER AND
DRIER AIR WILL BE ARRIVING BEHIND THE FRONT AND TEMPS WILL BE
FALLING INTO THE LOWER 50S NORTH TO MID 60S SOUTH.
WEDNESDAY...A SLIGHT CHANCE OF SHOWERS WILL LINGER ACROSS CENTRAL
WISCONSIN AND THE SOUTHERN FOX VALLEY IN THE MORNING...BUT ELEVATED
CONVERGENCE HAS WEAKENED ENOUGH BY THIS TIME THAT DO NOT THINK THERE
WILL BE MANY ECHOES AROUND. AS A RESULT...WENT DRY FOR THE
AFTERNOON. NORTHERN AND NORTHEAST WISCONSIN WILL ENJOY A COOLER AND
LESS HUMID DAY UNDER PARTLY TO MOSTLY SUNNY CONDITIONS...WITH HIGHS
RANGING FROM THE UPPER 70S TO MID 80S. A FEW UPPER 80S WILL STILL
BE POSSIBLE OVER CENTRAL WISCONSIN.
.LONG TERM...WED NGT THRU NXT TUE. THE LARGE SCALE PATTERN IS
EXPECTED TO CONSIST OF A STRONG/PERSISTENT UPR RDG ALOFT OVER THE
CNTRL ROCKIES/CNTRL PLAINS AND AN UPR TROF OVER THE ERN CONUS.
BIGGEST FCST ISSUE REMAINS THE HANDLING OF SHORTWAVE TROFS MOVING
FROM THE NE PACIFIC...THRU SRN CANADA...THEN DROPPING SE INTO THE
ERN UPR TROF. EACH OF THESE SHORTWAVE TROFS WL BE ACCOMPANIED BY A
WEAK CDFNT WHICH ARE FCST TO DROP INTO WI AND EVENTUALLY STALL AS
THEY ENCOUNTER THE UPR RDG. ANY PCPN CHCS WL BE TIED TO THESE
CDFNTS...BUT AT LEAST WE WL HAVE A COUPLE CHCS FOR PCPN IN THE
EXTENDED PERIOD. TEMPS WL REMAIN ABOVE NORMAL UNTIL FURTHERN
NOTICE.
WHILE THE SFC BOUNDARY REMAINS QUASI-STNRY ACROSS CNTRL IA/NRN IL
WED NGT...THE 8H BOUNDARY TO SIT ACROSS SRN WI WITH A TIGHT
BAROCLINIC ZONE IN THE VCNTY OF THE 8H BOUNDARY. A SHORTWAVE TROF
IS FCST TO MOVE INTO THE WRN GREAT LKS BRINGING MODEST LEVELS OF
FRONTOGENETICAL FORCING INTO THE SRN HALF OF WI. BEST CONVERGENCE
SHOULD BE OVER SRN WI AS WELL...BUT CLOSE ENUF TO WARRANT CHC POPS
OVER CNTRL/E-CNTRL WI. NRN WI APPEARS TO BE TOO FAR AWAY FROM THE
PRIMARY FORCING/LIFT...THUS WL ONLY MENTION SLGT CHC POPS FOR THE
FAR NORTH.
PCPN CHCS ACROSS CNTRL/E-CNTRL WI SHOULD GRADUALLY DIMINISH THU
MORNING AS THE SHORTWAVE TROF BEGINS TO PULL AWAY FROM THE REGION.
A WEAK AREA OF HI PRES IS THEN SET TO BUILD SOUTH INTO THE NRN/WRN
GREAT LKS THU AFTERNOON AND BRING SOME MIXED SUNSHINE BACK TO NE
WI. MAX TEMPS ARE EXPECTED TO BE CLOSE TO SEASONAL NORMALS WITH
PLENTY OF LOCATIONS REACHING THE 80 TO 85 DEG RANGE (COOLER
LAKESIDE).
AS THE HI PRES SETTLES OVER THE REGION THU NGT...QUIET AND MORE
COMFORTABLE CONDITIONS WL EXIST AS COOLER/DRIER AIR FILTERS INTO
NE WI. UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS...THU NGT APPEARS
TO BE THE COOLEST NGT OF THE EXTENDED PERIOD WITH READINGS DIPPING
INTO THE LWR 50S NORTH...AROUND 60 DEGS E-CNTRL WI. NE WI TO STILL
RESIDE IN A NW FLOW ALOFT THRU FRI WITH THE BACK EDGE OF HI PRES
REACHING INTO WI. CLOCKWISE CIRCULATION AROUND THE SFC HI WL BRING
SOME COOLING TO THE LAKESHORE ON E-SE WINDS. THE REST OF THE FCST
AREA TO SEE MORE OF A S-SE WIND AND WITH PLENTY OF SUNSHINE
ANTICIPATED...TEMPS WL BEGIN TO GET WARM ONCE AGAIN AS READINGS
REACH THE MID TO UPR 80S.
ATTENTION TURNS TO OUR NORTH AND WEST FRI NGT WHERE A CDFNT WL
ATTEMPT TO PUSH SE INTO THE WRN GREAT LKS. AS HAS BEEN THE CASE OF
LATE...ANY CDFNT HAS BEEN A SLOW MOVER AND THIS LATEST ONE IS NO
DIFFERENT. LATEST MDL TIMING HAS THIS FNT ONLY REACHING NRN
SECTIONS OF THE GREAT LKS BY SAT AFTERNOON...THUS HAVE MAINTAINED
A DRY FRI NGT AND ONLY A MINIMAL POP FOR THE NORTH ON SAT. A MORE
PREVAILING S-SW WIND WL BRING WARMER/MORE HUMID AIR MASS INTO WI
WITH MAX TEMPS ON SAT AGAIN FLIRTING WITH 90 DEGS AND DEW POINTS
IN THE MID 60S. THE SLOW NATURE OF THIS CDFNT IS EVIDENT AS THE
MDLS NOW DO NOT BRING THE BOUNDARY INTO NRN WI UNTIL SUNDAY. BROAD
LOW-LEVEL WAA COUPLED WITH INCREASING INSTABILITY (CAPES BETWEEN
1K AND 2K J/KG/LI`S AROUND -4)...PLENTY OF MOISTURE (DEW POINTS
IN THE MID TO UPR 60S) AND THE FNT ITSELF SHOULD BE ABLE TO
GENERATE AT LEAST A CHC FOR SHWRS/TSTMS ESPECIALLY OVER THE NORTH.
TEMPS FOR SUNDAY MAY BE TRICKY DEPENDING ON THE AMOUNT OF CLOUD
COVER/EXTENT OF ANY PCPN...BUT DUE TO THE EXPECTED WARM START TO
THE DAY...ANOTHER VERY WARM DAY ON TAP WITH PLENTY OF UPR 80S TO
LWR 90S OVER THE REGION.
THE CDFNT IS PROGGED TO SLOWLY SAG THRU CNTRL/E-CNTRL WI SUNDAY
NGT...BUT WITH THE LOSS OF DAYTIME HEATING...THE SHWR/TSTM
ACTIVITY MAY BECOME MORE WIDELY SCATTERED WITH TIME. ANY PCPN CHCS
FOR MON WL BE FOCUSED OVER THE SRN HALF OF WI AS THE FNT GRINDS TO
A HALT AS IT HITS THE UPR RDG. TEMPS ARE FCST TO BE A BIT COOLER
BY MON WITH LOWER DEW POINTS OVER THE NORTH AS DRIER AIR TRIES TO
PUSH INTO THE AREA. WINDS ARE FCST TO BACK SW ONCE AGAIN BY NXT
TUE AHEAD OF THE NXT CDFNT WHICH IS EXPECTED TO MOVE ACROSS THE
UPR MS VALLEY. BETTER UPR SUPPORT TO BE SITUATED WELL TO OUR NORTH
WHERE A PROMINENT SHORTWAVE TROF TO BE SITUATED. NEVERTHELESS...MAY
NEED TO CARRY SOME SORT OF POP ACROSS PORTIONS OF THE FCST AREA TO
ACCOUNT FOR INCREASING LOW-LEVEL WAA/INSTABILITY PARAMETERS.
&&
.AVIATION...NEARLY WEST TO EAST BANDS OF CONVECTION WILL LINGER
THIS WEDNESDAY MORNING OVER CENTRAL AND EAST CENTRAL WISCONSIN.
MVFR CIGS AND VSBYS WILL BE ASSOCIATED WITH THE SHOWERS AND
STORMS. ACROSS NORTHERN WISCONSIN...PATCHY MVFR VSBYS DUE TO FOG
POSSIBLE THROUGH 14Z. OTHERWISE VFR CONDITIONS WILL PREVAIL TODAY.
SHOWERS AND STORMS WILL BE ON THE INCREASE WEDNESDAY NIGHT.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1153 PM CDT TUE JUL 17 2012
.SHORT TERM...THROUGH THURSDAY NIGHT
248 PM CDT TUE JUL 17 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A COLD FRONT ACROSS SOUTHERN
MINNESOTA INTO CENTRAL WISCONSIN. REGIONAL RADARS INDICATE STORMS
HAVE DEVELOPED NORTH OF THE FRONT ACROSS WISCONSIN.
THE CONVECTION ACROSS WISCONSIN HAS DEVELOPED IN RESPONSE TO A
WEAK SHORT WAVE TROUGH THAT DEVELOPED OUT OF THE STORMS OVER THE
DAKOTAS LAST NIGHT. THIS IS ALSO BEING AIDED BY THE RIGHT ENTRACE
REGION OF THE UPPER LEVEL JET OVER LAKE SUPERIOR. THE BEST CAPE
EXISTS ALONG AND AHEAD OF THE FRONT WITH AN AXIS OF 2500 J/KG OF
ML CAPE FROM CENTRAL INTO EAST CENTRAL WISCONSIN. AS THE WAVE
MOVES EAST THIS AFTERNOON...WOULD EXPECT THE CONVECTION TO
GRADUALLY SINK TO THE SOUTHEAST TOWARD THE HIGHER CAPE BUT MOST
SHOULD REMAIN BEHIND THE FRONT WHERE THERE IS NO CAP IN PLACE. THE
17.12Z HI-RES ARW AND 17.15Z HRRR SHOW THIS TREND OCCURRING WITH
THE BEST CHANCE OF ANYTHING CLIPPING THE AREA IN THE I94 CORRIDOR.
AFTER THIS EVENING THROUGH WEDNESDAY...ANY ACTIVITY THAT DEVELOPS
WILL BE CLOSELY TIED TO THE POSITION OF THE FRONT. THE 17.12Z
MODELS ALL HAVE DIFFERENT SOLUTIONS ON HOW FAR SOUTH THE FRONT
WILL GET BEFORE STALLING OUT. THE NAM AND GFS TAKE THE FRONT INTO
CENTRAL IOWA AND NORTHERN ILLINOIS TONIGHT WHILE THE 17.00Z ECMWF
HAS THE FRONT FROM NORTHERN IOWA ALONG THE WISCONSIN/ILLINOIS
BORDER. ALL THE MODELS SHOW JUST A SLOW SOUTHWARD DRIFT TO THE
FRONT WEDNESDAY. AT THIS POINT...NOT EXPECTING ANY SHORT WAVE
TROUGHS TO INTERACT WITH THE FRONT...BUT THAT COULD CHANGE IF
CONVECTION DEVELOPS OVER THE HIGH PLAINS TUESDAY NIGHT.
THE MODELS THEN DO SHOW A SHORT WAVE TROUGH COMING OUT OF THE FLOW
OVER THE ROCKIES AND TOPPING THE UPPER LEVEL RIDGE AND MOVING
ACROSS MINNESOTA AND WISCONSIN. AGAIN...THE POSITION OF THE FRONT
WILL HAVE A BIG IMPACT ON WHERE ANY CONVECTION MAY DEVELOP. WOULD
BE MORE ENTHUSED ABOUT THE RAIN CHANCES WITH THIS WAVE IF THERE
WAS ANY MOISTURE TRANSPORT OF SIGNIFIGANCE WITH THE WAVE. WITH THE
LACK OF RETURNING MOISTURE AND ANECEDENT DRY CONDTIONS...HAVE HELD
THE RAIN CHANCES FOR WEDNESDAY NIGHT AROUND 40 PERCENT. AS THIS
WAVE THEN EXITS OFF TO THE EAST THURSDAY...EXPECT THE RAIN TO MOVE
EAST AS WELL DURING THE DAY WITH A DRY THURSDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NORTH.
.LONG TERM...FRIDAY THROUGH TUESDAY
248 PM CDT TUE JUL 17 2012
THE HIGH THEN LOOKS TO REMAIN OVER THE AREA INTO THE START OF THE
WEEKEND BEFORE THE NEXT FRONT STARTS TO SINK INTO THE AREA.
CURRENT INDICATIONS ARE THAT THIS FRONT WILL MOVE SOUTH ACROSS THE
AREA FROM SATURDAY NIGHT THROUGH MONDAY. THE UPPER LEVEL RIDGE IS
STILL EXPECTED TO BE ANCHORED OVER THE CENTRAL PART OF THE COUNTRY
WITH THE BULK OF THE SHORT WAVE ENERGY RIDING UP OVER THE RIDGE
ACROSS SOUTHERN CANADA. NOT OUT OF THE REALM OF POSSIBILITY THAT
ONE OF THESE WAVES COULD TEMPORARILY FLATTEN THE RIDGE AND GET
INTO THE AREA...BUT WOULD NOT COUNT ON THIS HAPPENING. THUS ANY
RAIN WITH THE FRONT SHOULD STAY ON THE SCATTERED SIDE.
&&
.AVIATION...THROUGH 06Z THURSDAY
1151 PM CDT TUE JUL 17 2012
FRONTAL BOUNDARY CONTINUES TO MEANDER NEARBY THE TAF SITES...MAKING
CONVECTIVE FORECAST DIFFICULT. ATTEMPTED TO NARROW DOWN THE MOST
LIKELY TIMING FOR ANY CONVECTION WITH VCTS. MODEL GUIDANCE CONTINUES
TO HINT AT THE POSSIBILITY FOR LIGHT FOG/MIST...BUT DID NOT ADD AS
IT LOOKS TO BE VERY LOW PROBABILITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
248 PM CDT TUE JUL 17 2012
WI...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR WIZ041>044-053>055-
061.
MN...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ094>096.
IA...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...MW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1103 AM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MADE SOME MINOR UPDATES TO THE GRIDS THIS MORNING TO INCREASE
CLOUD COVER AND ADD SLGT CHC POPS FOR A FEW SHRA THAT HAVE
DEVELOPED WITHIN ZONE OF ENHANCED MID LEVEL LIFT ACROSS CT/LI.
THIS SHOULD MOVE OFF TO THE E WITH A FEW HRS OF SUNSHINE EXPECTED.
ONLY OTHER CHANGE TO THE FORECAST WAS TO INCREASE MAX TEMPS ACROSS
LI BY 1-2 DEGREES. MAX TEMPS REALLY CLIMBING FAST...AND ARE
ALREADY WITHIN A FEW DEGREES OF MAX TEMPS ELSEWHERE SO THESE MAY
NEED TO BE ADJUSTED UPWARD. LOOKS LIKE AN ACTIVE AFTERNOON WITH CAP
RAPIDLY ERODING. AREA REMAINS IN A SLIGHT RISK FROM SPC. SEE BELOW
FOR DETAILS ON WHAT IS EXPECTED.
OTHERWISE...A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO
THE REGION THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF
A VERY HOT AIR MASS...DAY STARTS OUT VERY WARM AND LARGE CAPE IN
THE 2000 TO 4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL
WARMING. SHEAR OF 30 KT 0-6KM WITH WET BULB ZERO HEIGHTS OF 13-14
KFT. MENTIONED GUSTY WINDS AND SMALL HAIL WITH SOME CELLS HAVING A
SLIGHT CHANCE OF GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES
WIDESPREAD...AT LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE
ENOUGH SUN TO HAVE HIGHS WELL INTO THE 90S AND WITH VERY MOIST
AIR MASS CONVEYED BY PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER
70S...HEAT INDICES ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW
YORK CITY AS WELL AS URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST
OF NE NJ AND WESTERN LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IS ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. FURTHER
DEVELOPMENT OF CONVECTION COULD ALSO OCCUR FROM CONVERGENCE ALONG
THE SEA BREEZE BOUNDARY ESPECIALLY WITH ANY OUTFLOW BOUNDARIES FROM
CONVECTION MOVING IN FROM THE NORTH AND WEST. WIND SHEAR OF 25 TO 30
KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE HAIL AND
GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO CAN BE EXPECTED
WITH THUNDERSTORMS THAT FORM. THIS IS CONSIDERED ESPECIALLY SINCE
THE FLOW WILL BE NEARLY PARALLEL FROM LOW TO MID LEVELS WHICH WOULD
ALLOW FOR TRAINING OF CELLS. THE CONVECTIVE MODE LOOKS TO BE SQUALL
LINE TO BOW ECHOES.
THERE IS A MODERATE RISK FOR RIP CURRENTS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...RELATIVELY BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE AS PWATS REMAIN NEAR 2 INCHES.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME LINGERING SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT.
POPS ARE AT SLIGHT CHANCE WITH MODEL UNCERTAINTY DUE TO DIFFERENCES
IN QPF FIELDS AND RUN TO RUN INCONSISTENCY. IN THE UPPER LEVELS AT
500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE TROUGH SETTING
UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER GUIDANCE FOR
HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING ANY
THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL APPROACH THIS AFTERNOON...AND PASS TO THE SOUTH
TONIGHT.
MAINLY VFR OUTSIDE OF TSTMS...ALTHOUGH HZ IS RESTRICTING VSBY TO
5SM AT KGON. HYBRID SEA BREEZE/SW FLOW ACROSS COASTAL TERMINALS
THIS AFTERNOON. WINDS BECOMING NW AND WEAKENING IN WAKE OF COLD
FRONTAL PASSAGE LATE THIS EVENING/TONIGHT.
TSTM DEVELOPMENT THIS AFTERNOON/EVENING HAS SOME UNCERTAINTIES.
IT NOW APPEARS THAT THERE MAY BE MULTIPLE ROUNDS OF STORMS...ONE
EARLY THIS AFTERNOON AS STORMS DEVELOP INVOF A PRE-FRONTAL LOW
PRESSURE TROUGH ALREADY IN PLACE OVER THE REGION...THEN A SECOND
ROUND LATE IN THE DAY AS THE COLD FRONT ENTERS THE AREA. TSTM FCST
IN AMENDED TAF ADDRESSES ON THE FIRST ROUND...AND THE 18Z TAF
WILL BETTER ADDRESS THE SECOND ROUND AS CONFIDENCE LEVEL INCREASES
ONE WAY OR THE OTHER. THREAT OF STRONG WINDS AND CONVECTIVE
LLWS...HAIL AND HEAVY RAINFALL EXISTS WITH STRONGER CONVECTION.
CONVECTION EXPECTED TO TAPER AND WEAKEN THIS EVENING.
MAINLY VFR IN WAKE OF COLD FROPA...EXCEPT PATCHY GROUND FOG ACROSS
OUTLYING TERMINALS.
...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: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
HYBRID SEA BREEZE/SW FLOW THIS AFTERNOON.
KLGA FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
KEWR FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING THROUGH THE AFTERNOON.
KHPN FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING THROUGH THE AFTERNOON.
KISP FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 17Z.
HYBRID SEA BREEZE/SW FLOW THIS AFTERNOON.
OUTLOOK FOR 12Z THU THROUGH SUN...
.THU-THU EVENING...VFR. SCT SHOWERS POSSIBLE.
.LATE THU NIGHT-SAT MORNING...MVFR CIGS POSSIBLE...BEST CHANCE AT
SOUTHERN/COASTAL TERMINALS.
.SAT AFTERNOON-SUN...VFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE AT TIMES ACROSS OUTER OCEAN
WATERS IN THE SHORT TERM THROUGH THURSDAY NIGHT. HOWEVER...KEPT
OCEAN SEAS BELOW 5 FT SINCE WAVEWATCH INITIALLY ABOUT A FOOT TOO
HIGH COMPARED TO OBS.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/4 TO 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ071>075-078-
080-176>179.
NJ...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NJZ004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...GS/JM
SHORT TERM...JM
LONG TERM...24
AVIATION...GOODMAN/NV
MARINE...24/JM
HYDROLOGY...24/JM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
741 AM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST GENERALLY ON TRACK WITH JUST SLIGHT DOWNWARD ADJUSTMENTS
WITH SOME TEMPS EARLY THIS MORNING AND CLOUD COVERAGE. DRY WEATHER
EXPECTED WITH RELATIVELY WARM CONDITIONS THIS MORNING.
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF A VERY HOT
AIRMASS...DAY STARTS OUT VERY WARM AND LARGE CAPE IN THE 2000 TO
4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL WARMING. SHEAR
OF 30 KT 0-6KM WITH WETBULB ZERO HEIGHTS OF 13-14 KFT. MENTIONED
GUSTY WINDS AND SMALL HAIL WITH SOME CELLS HAVING A SLIGHT CHANCE
OF GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES
WIDESPREAD...AT LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE
ENOUGH SUN TO HAVE HIGHS WELL INTO THE 90S AND WITH VERY MOIST
AIRMASS CONVEYED BY PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER
70S...HEAT INDICES ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW
YORK CITY AS WELL AS URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST
OF NE NJ AND WESTERN LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IS ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. FURTHER
DEVELOPMENT OF CONVECTION COULD ALSO OCCUR FROM CONVERGENCE ALONG
THE SEA BREEZE BOUNDARY ESPECIALLY WITH ANY OUTFLOW BOUNDARIES FROM
CONVECTION MOVING IN FROM THE NORTH AND WEST. WIND SHEAR OF 25 TO 30
KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE HAIL AND
GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO CAN BE EXPECTED
WITH THUNDERSTORMS THAT FORM. THIS IS CONSIDERED ESPECIALLY SINCE
THE FLOW WILL BE NEARLY PARALLEL FROM LOW TO MID LEVELS WHICH WOULD
ALLOW FOR TRAINING OF CELLS. THE CONVECTIVE MODE LOOKS TO BE SQUALL
LINE TO BOW ECHOES.
THERE IS A MODERATE RISK FOR RIP CURRENTS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...RELATIVELY BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE AS PWATS REMAIN NEAR 2 INCHES.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME LINGERING SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT.
POPS ARE AT SLIGHT CHANCE WITH MODEL UNCERTAINTY DUE TO DIFFERENCES
IN QPF FIELDS AND RUN TO RUN INCONSISTENCY. IN THE UPPER LEVELS AT
500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE TROUGH SETTING
UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER GUIDANCE FOR
HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING ANY
THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT MOVES INTO THE TERMINALS DURING THE AFTERNOON...MOVING
SOUTH THIS EVENING.
MAINLY VFR OUTSIDE OF TSTMS...ALTHOUGH HZ MAY RESTRICT VSBY TO
AROUND 6SM ACROSS COASTAL TERMINALS. OCCASIONAL GUSTY SW WINDS AT
NYC/NJ TERMINALS THIS MORNING THROUGH AFTERNOON. HYBRID
SEABREEZE/SW FLOW ACROSS COASTAL TERMINALS THIS
AFTERNOON. WINDS BECOMING NW AND WEAKENING IN WAKE OF COLD FRONTAL
PASSAGE LATE THIS EVENING/TONIGHT.
CONVECTION DEVELOPMENT IN COSPA APPEARS TO BE A BIT TOO SLOW. CCFP
LOOKS REASONABLE THROUGH 17Z WITH EXPECTATION FOR ISOLATED TSTMS
COVERAGE FROM LATE MORNING THROUGH 17Z. THEN THUNDERSTORM
COVERAGE EXPECTED TO INCREASE TO NUMEROUS THROUGH THE AFTERNOON
AND INTO THE EARLY EVENING. THREAT OF GUSTY WINDS...HAIL AND HEAVY
RAINFALL EXISTS WITH STRONGER CONVECTION. CONVECTION EXPECTED TO
TAPER AND WEAKEN DURING THROUGH THE EVENING HOURS.
MAINLY VFR IN WAKE OF COLD FRONTAL PASSAGE...EXCEPT PATCHY GROUND
FOG ACROSS OUTLYING TERMINALS.
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: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
HYBRID SEABREEZE/SW FLOW THIS AFTERNOON.
KLGA FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
KEWR FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING THROUGH THE AFTERNOON.
KHPN FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING THROUGH THE AFTERNOON.
KISP FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
HYBRID SEABREEZE/SW FLOW THIS AFTERNOON.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
.THURSDAY-THURSDAY EVENING...VFR. SCATTERED SHOWERS POSSIBLE.
.LATE THURSDAY NIGHT-SATURDAY MORNING...CEILINGS 1500 FT TO 2500 FT
POSSIBLE...BEST CHANCE AT SOUTHERN/COASTAL TERMINALS.
.SATURDAY AFTERNOON-SUNDAY...VFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE AT TIMES ACROSS OUTER OCEAN
WATERS IN THE SHORT TERM THROUGH THURSDAY NIGHT. HOWEVER...KEPT
OCEAN SEAS BELOW 5 FT SINCE WAVEWATCH INITIALLY ABOUT A FOOT TOO
HIGH COMPARED TO OBS.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVSY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/4 TO 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ071-078-080-
177-179.
NJ... HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NJZ004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...NV
MARINE...24/JM
HYDROLOGY...24/JM
AREA FORECAST DISCUSSION
NWS ALBANY NY
658 AM EDT WED JUL 18 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY MOVE SOUTHWARD ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND TODAY WITH SOME SHOWERS AND THUNDERSTORMS. A
BROAD AREA OF HIGH PRESSURE WILL BUILD IN FROM JAMES BAY TONIGHT
INTO THURSDAY WITH SEASONABLE TEMPERATURES AND LESS HUMID
CONDITIONS. A DISTURBANCE MOVING ALONG THE OLD FRONTAL BOUNDARY
OVER THE UPPER MID ATLANTIC REGION MAY BRING A FEW SHOWERS TO
LOCATIONS SOUTH OF THE CAPITAL REGION THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 650 AM EDT...COLD FRONT CONTINUES TO GRADUALLY MOVE SOUTH
ACROSS THE REGION THIS MORNING ALONG ROUGHLY A KCLE-KROC-KGFL-KPWM
AXIS. THE DEWPT BOUNDARY LAGS FURTHER NORTH AND WEST NEAR THE ST
LAWRENCE RIVER VALLEY. THE RADAR IS CURRENTLY QUIET...BUT WITH
PARTLY CLOUDY CONDITIONS FROM ALY SOUTH AND EAST...SOME ISOLD-SCT
SHOWERS/TSTMS WILL LIKELY DEVELOP NEAR THE MOHAWK RIVER VALLEY
BTWEEN 7 AM AND 10 AM. HOURLY T/TD/RH/APPARENT TEMPS RETRENDED
BASED ON OBSERVATIONS.
ONE MORE HUMID DAY IS EXPECTED ACROSS ERN NY AND
WRN NEW ENGLAND...AS RELIEF IS ON THE WAY. A MOIST AIR MASS IS IN
PLACE WITH SFC DEWPTS IN THE M60S TO L70S OVER THE FCST AREA. A
LULL IN THE CONVECTIVE ACTIVITY HAS OCCURRED OVER THE PAST FEW
HOURS...BUT CONVECTIVE INITIATION SHOULD INCREASE QUICKLY IN THE
LATE MORNING AND EARLY PM.
GENERAL THINKING HAS NOT CHANGED TOO MUCH WITH THE BEST DEEP SHEAR
AND INSTABILITY COMPOSITE OVERLAYS FROM THE NAM/GFS FOR LOCATIONS
JUST SOUTH AND EAST OF THE CAPITAL DISTRICT FOR POSSIBLE SVR WX TODAY.
CAUTION HAS TOO BE USED WITH THE GFS INSTABILITY CHARTS...AS SFC
DEWPTS ARE WELL INTO THE M70S OVER A LARGE CHUNK OF THE AREA SOUTH
OF ALBANY. A CORRECTION TO U60S TO L70S STILL YIELDS SBCAPE VALUES
IN THE 1000-2000 J/KG WITH SLIGHTLY HIGHER AMOUNTS. THE DEEP SHEAR
VALUES ARE ON THE NORTH SIDE OF THE BOUNDARY WITH 45-60
KTS. HOWEVER...0-6 KM BULK SHEAR VALUES ON THE NAM/GFS ARE STILL
30-40 KT FROM ALY SOUTH AND EAST. THERE MAY BE ENOUGH CONVERGENCE
AND LIFT WITH THE BOUNDARY FOR A FEW STRONG TO SEVERE STORMS. WE
ARE GOING TO DEVIATE SLIGHTLY FROM THE LATEST DAY 1 GRAPHIC...AND
FOCUS ON THE SEVERE THREAT FOR MAINLY THE ERN CATSKILLS...MID
HUDSON VALLEY...CNTRL AND SRN TACONICS...BERKSHIRES...AND NW CT.
THE COUNTIES WE WILL HIGHLIGHT IN THE HWO WILL BE
GREENE...ULSTER...COLUMBIA...DUTCHESS...BERKSHIRE...AND
LITCHFIELD.
PWAT VALUES WILL STILL BE IN THE 1.50-2.00 INCH RANGE FROM THE
CAPITAL REGION...MOHAWK VALLEY SOUTH AND EAST. SOME LOCALLY HEAVY
DOWNPOURS WILL BE POSSIBLE...AND SOME LOCATIONS COULD GET A QUICK
INCH OR TWO OF RAIN. FLASH FLOODING IS NOT EXPECTED. ALSO...THE
STRONG FLOW ALOFT SHOULD CONTINUE TO MOVE THE CONVECTION ALONG
DURING THE DAY.
CONVECTIVE INITIATION SHOULD OCCUR QUICKER TODAY WITH AN ERODING
CAP...AND THE CLOSER PROXIMITY OF THE FRONTAL BOUNDARY. THE
THUNDERSTORMS SHOULD POP UP AS SOON AS THE LATE MORNING IN THE
CNTRL-NRN PORTIONS OF CWA...AND SPREAD SOUTH OF ALY. WE KEPT THE
HIGHEST CHC TO LIKELY POPS FROM ALY SOUTH AND EAST DURING THE AFTERNOON.
HEAT INDICES/APPARENT TEMPS WILL GET INTO THE MID AND U90S OVER
PORTIONS OF THE MID HUDSON VALLEY...AND LITCHFIELD COUNTY...BUT
THEY SHOULD FALL SHY OF ADVISORY LEVELS WITH THE SHOWERS AND
THUNDERSTORMS MOVING IN. LATEST HIRES WRF HAS THE MOST ROBUST
CONVECTION WITH THE COMPOSITE REF PRODUCT GRAZING SRN DUTCHESS...AND
LITCHFIELD COUNTIES AFTER 21Z...THE LATEST HRRR IS A LITTLE BIT
FURTHER NORTH...BUT STILL SOUTH OF THE CAPITAL REGION...BUT HAS
THE STRONGER CONVECTION IMPACTING THE AREA BTWN 18Z-21Z. DAMAGING
WIND GUSTS WOULD BE THE MAIN THREAT WITH POTENTIAL BOWING SEGMENTS
WITH UNIDIRECTIONAL SHEAR PROFILES ON THE MODEL SOUNDINGS.
MAX TEMPS WILL RANGE FROM THE M80S TO L90S IN THE VALLEYS...WITH
SOME U70S OVER THE NRN MTNS TO LOWER TO MID80S OVER THE HILLS AND
MTNS SOUTH OF ALBANY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT...THE FRONT DIPS SOUTH OF THE FORECAST AREA WITH THE ISOLD-
SCT SHOWER AND THUNDERSTORM ACTIVITY ENDING BY AROUND MIDNIGHT FOR
THE SRN MOST ZONES. THE LOW LEVEL COLD ADVECTION WILL ALLOW H850
TEMPS TO LOWER TO 10 TO 14C FROM THE CAPITAL REGION NORTH AND
WEST...AND 14-17C TO THE SOUTH AND EAST. THE SKIES SHOULD CLEAR
OVERNIGHT...AND LOWS WILL BE IN THE U40S TO M50S NORTH OF
ALY...AND U50S TO L60S SOUTH AND EAST.
THURSDAY...A VERY NICE DAY IS SHAPING UP WITH STRONG SUBSIDENCE
IN WAKE OF THE FRONT...AND A LARGE SFC ANTICYCLONE BUILDING IN
FROM ONTARIO AND JAMES BAY. FEW-SCT FAIR WX CUMULUS WILL BE
AROUND...AND DECENT MIXING WILL ALLOW MAX TEMPS TO BE IN THE LOWER
TO M80S IN THE VALLEYS...AND MAINLY 70S OVER THE HILLS AND MTNS
/SOME U60S TOO/.
THURSDAY NIGHT...H500 UPPER LOW CONTINUES TO LIFT N/NE INTO THE
CANADIAN MARITIMES WITH BROAD SFC HIGH CONTINUING TO RIDGE IN FROM
JAMES BAY. FRONTAL BOUNDARY FROM WED...BECOMES STATIONARY OVER THE
MID ATLANTIC REGION. THE NAM/GFS/ECMWF/CAN GUIDANCE ALL SHOW A
DISTURBANCE MOVING ALONG THE BOUNDARY...WITH SOME THERMAL
ADVECTION SHOWERS GETTING INTO THE MID HUDSON VALLEY. WE PLACED
SOME SLIGHT CHC POPS FOR SHOWERS WELL SOUTH OF THE CAPITAL
REGION...OTHERWISE IT SHOULD BE A COOL AND COMFORTABLE EVENING
WITH LOWS IN THE 50S...EXCEPT FOR SOME 40S OVER THE SRN
DACKS...AND SRN GREENS...AND SOME L60S OVER THE MID HUDSON VALLEY.
FRI-FRI NIGHT...CLOUDS CONTINUE TO SPILL NORTH WITH THE WAVE
RIDING THE FRONTAL BOUNDARY OVER THE MID ATLANTIC REGION. THE SREF
POPS STILL REMAIN LOW IN THE SLIGHT CHC CATEGORY. WEAK THETA-E
ADVECTION AND ISENTROPIC LIFT COULD ALLOW A FEW-SCT SHOWERS SOUTH
OF THE CAPITAL REGION. MAX TEMPS WILL ACTUALLY BE WARMER FROM THE
CAPITAL REGION NORTH...WHERE MORE SUNSHINE MAY OCCUR. THE CLOUDS
AND ISOLD-SCT SHOWERS SHOULD CLEAR FRI NIGHT...AS THE SFC RIDGE
BUILDS BACK IN. TEMPS MAY ACTUALLY RUN A SHADE BELOW NORMAL THIS
DAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE LONG TERM PERIOD IS EXPECTED TO START DRY WITH THE POSSIBILITY
OF SOME UNSETTLED WEATHER LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
TEMPS AND HUMIDITY WILL START TO INCREASE SLOWLY AS THE RIDGE OF
HIGH PRESSURE SLIDES OFF THE EASTERN SEABOARD AND A RETURN FLOW
STARTS TO DEVELOP. DRY WEATHER IS EXPECTED TO CONTINUE THROUGH
SUNDAY MORNING WITH WIDELY SCATTERED TO SCATTERED SHOWERS DEVELOPING
SUNDAY AFTERNOON AND CONTINUING INTO SUNDAY EVENING AS A COLD FRONT
DROPS SOUTHEAST TOWARD THE SAINT LAWRENCE VALLEY. EXPECT A BETTER
CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY EVENING AS
THE COLD FRONT WORKS SOUTHEASTWARD THROUGH THE FA ENDING UP ACROSS
SOUTHEAST NY AND SOUTHERN NEW ENGLAND TUESDAY MORNING.
H8 TEMPS ARE EXPECTED TO RISE FROM +10 TO +11 C SATURDAY MORNING TO
+15 TO +17 C LATE SUNDAY AHEAD OF THE COLD FRONT AND THEN DROP TO
+10 TO +14 C BY LATE TUESDAY IN THE WAKE OF THE COLD FRONT.
EXPECT HIGHS ON SATURDAY TO BE IN THE MID 70S TO LOWER 80S...UPPER
70S TO MID 80S ON SUNDAY AND MONDAY...AND LOWER 70S TO MID 80S ON
TUESDAY. LOWS ARE GENERALLY EXPECTED TO BE IN THE MID 50S TO MID
60S...SATURDAY NIGHT THROUGH MONDAY NIGHT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE UNTIL THE PASSAGE OF A
COLD FRONT LATE TODAY. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS
WILL BE ACROSS SOUTHERN AREAS AHEAD OF THE COLD FRONT THIS AFTERNOON
WITH CLEARING EXPECTED AT THE TAF SITES DURING THE EVENING.
WINDS WILL BECOME WEST TO NORTHWEST TODAY AND THEN EVENTUALLY
NORTHWEST TO NORTH AT 5 TO 10 KTS IN THE WAKE OF THE COLD FRONT. THE
EXCEPTION WILL BE AT KPOU WHERE SOUTHWEST WINDS AT 4-6 KTS ARE
EXPECTED THROUGH THIS AFTERNOON WILL BECOME NORTH AT AROUND 3 KTS
EARLY THIS EVENING. WINDS AT ALL THE TAF SITES WILL THEN BECOME
LIGHT AND VARIABLE BY MID TO LATE EVENING.
OUTLOOK...
THU-SAT..NO SIG WX.
SUN...VFR...SLIGHT CHC AFTERNOON TSTMS.
&&
.FIRE WEATHER...
A COLD FRONT WILL SLOWLY MOVE SOUTHWARD ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND TODAY WITH SOME SHOWERS AND THUNDERSTORMS. A
BROAD AREA OF HIGH PRESSURE WILL BUILD IN FROM JAMES BAY TONIGHT
INTO THURSDAY WITH SEASONABLE TEMPERATURES AND LESS HUMID
CONDITIONS.
RELATIVE HUMIDITY VALUES WILL LOWER TO 40-70 PERCENT TODAY...AND
RECOVER TO 90 TO 100 PERCENT TONIGHT. EXPECT MINIMUM RH VALUES OF
25 TO 50 PERCENT THURSDAY AFTERNOON.
THE WINDS WILL BE FROM THE WEST OR NORTHWEST AT 5 TO 15 MPH
TODAY...AND DECREASE TO LESS THAN 10 MPH TONIGHT. NORTH WINDS OF 5
TO 15 MPH WILL BE COMMON ON THURSDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TODAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A SHORT PERIOD OF
ANOMALOUSLY HIGH PRECIPITATELY WATER VALUES IN THE 1.5 TO 2 INCH
RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR DRAINAGE FLOODING
IS POSSIBLE ESPECIALLY FROM THE CAPITAL REGION SOUTH. ZONAL FLASH FLOOD
GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE POTENTIAL FOR FLASH
FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO SERVICE AREA.
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...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
650 AM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST GENERALLY ON TRACK WITH JUST SLIGHT DOWNWARD ADJUSTMENTS
WITH SOME TEMPS EARLY THIS MORNING AND CLOUD COVERAGE. DRY WEATHER
EXPECTED WITH RELATIVELY WARM CONDITIONS THIS MORNING.
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF A VERY HOT
AIRMASS...DAY STARTS OUT VERY WARM AND LARGE CAPE IN THE 2000 TO
4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL WARMING. SHEAR
OF 30 KT 0-6KM WITH WETBULB ZERO HEIGHTS OF 13-14 KFT. MENTIONED
GUSTY WINDS AND SMALL HAIL WITH SOME CELLS HAVING A SLIGHT CHANCE
OF GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES
WIDESPREAD...AT LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE
ENOUGH SUN TO HAVE HIGHS WELL INTO THE 90S AND WITH VERY MOIST
AIRMASS CONVEYED BY PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER
70S...HEAT INDICES ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW
YORK CITY AS WELL AS URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST
OF NE NJ AND WESTERN LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IS ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. FURTHER
DEVELOPMENT OF CONVECTION COULD ALSO OCCUR FROM CONVERGENCE ALONG
THE SEA BREEZE BOUNDARY ESPECIALLY WITH ANY OUTFLOW BOUNDARIES FROM
CONVECTION MOVING IN FROM THE NORTH AND WEST. WIND SHEAR OF 25 TO 30
KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE HAIL AND
GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO CAN BE EXPECTED
WITH THUNDERSTORMS THAT FORM. THIS IS CONSIDERED ESPECIALLY SINCE
THE FLOW WILL BE NEARLY PARALLEL FROM LOW TO MID LEVELS WHICH WOULD
ALLOW FOR TRAINING OF CELLS. THE CONVECTIVE MODE LOOKS TO BE SQUALL
LINE TO BOW ECHOES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...RELATIVELY BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE AS PWATS REMAIN NEAR 2 INCHES.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME LINGERING SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT.
POPS ARE AT SLIGHT CHANCE WITH MODEL UNCERTAINTY DUE TO DIFFERENCES
IN QPF FIELDS AND RUN TO RUN INCONSISTENCY. IN THE UPPER LEVELS AT
500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE TROUGH SETTING
UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER GUIDANCE FOR
HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING ANY
THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN IN THE VICINITY THIS
MORNING...THEN A COLD FRONT MOVES INTO THE TERMINALS DURING THE
AFTERNOON...MOVING SOUTH THIS EVENING.
MAINLY VFR OUTSIDE OF TSTMS...ALTHOUGH HZ MAY RESTRICT VSBY TO
AROUND 6SM ACROSS COASTAL TERMINALS. OCCASIONAL GUSTY SW WINDS AT
NYC/NJ TERMINALS FROM MID MORNING ON.
ISOLATED TSTMS POSSIBLE BY LATE MORNING...BECOMING LIKELY IN THE
EARLY AFTERNOON AND CONTINUING INTO THE EARLY EVENING. THREAT OF
GUSTY WINDS...HAIL AND HEAVY RAINFALL EXISTS WITH STRONGER
CONVECTION. CONVECTION EXPECTED TO TAPER AND WEAKEN DURING THROUGH
THE EVENING HOURS.
HYBRID SEABREEZE AND SW FLOW ACROSS COASTAL TERMINALS THIS
AFTERNOON.
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: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. HYBRID SEABREEZE/SW FLOW THIS AFTERNOON.
KLGA FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS.
KEWR FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING
THROUGH THE AFTERNOON.
KHPN FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING
THROUGH THE AFTERNOON.
KISP FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. HYBRID SEABREEZE/SW FLOW THIS AFTERNOON.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.LATE TONIGHT...MAINLY VFR...EXCEPT PATCHY GROUND FOG ACROSS
OUTLYING TERMINALS.
.THURSDAY-THURSDAY EVENING...VFR. SCATTERED SHOWERS POSSIBLE.
.LATE THURSDAY NIGHT-SATURDAY MORNING...CEILINGS 1500 FT TO 2500 FT
POSSIBLE...BEST CHANCE AT SOUTHERN/COASTAL TERMINALS.
.SATURDAY AFTERNOON-SUNDAY...VFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE AT TIMES ACROSS OUTER OCEAN
WATERS IN THE SHORT TERM THROUGH THURSDAY NIGHT. HOWEVER...KEPT
OCEAN SEAS BELOW 5 FT SINCE WAVEWATCH INITIALLY ABOUT A FOOT TOO
HIGH COMPARED TO OBS.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVSY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/4 TO 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NYZ071-078-080-177-179.
NJ...HEAT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NJZ004-006-103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...NV
MARINE...24/JM
HYDROLOGY...24/JM
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1046 AM EDT WED JUL 18 2012
.UPDATE...
NOT MUCH IN THE WAY OF CHANGES TO THE FORECAST THIS MORNING.
CLOUD COVERAGE HAS SLOWED HOURLY TEMPS SO DID MAKE ADJUSTMENTS TO
HOURLY TRENDS. THERE ARE SOME BREAKS IN THE CLOUDS ACROSS THE CWA
SO DID NOT ADJUST MAX TEMPS FOR NOW. AS PREVIOUSLY NOTED
THOUGH....RAIN TODAY WILL HAVE AN IMPACT ON WHETHER ALL SITES
REACH THEIR FORECAST MAX TEMPS...TO LOCALIZED THOUGH FOR
ADJUSTMENTS AT THIS TIME.
HAVE ALREADY SEEN ACTIVITY ALL MORNING...BUT STILL EXPECTING MORE
COVERAGE BY THIS AFTERNOON...UNCERTAINTY THOUGH IN BEING ABLE TO
NARROW DOWN TIMING ANY FURTHER. WRF NMM AND HRRR /ALTHOUGH THE
HRRR RUN ISNT FOR THE MOST RECENT TIME PERIOD/ SUGGEST BEST
CHANCES OF RAIN THROUGH ABOUT MID AFTERNOON WHEREAS THE LOCAL WRF
MODEL SUGGESTS THE BEST CHANCE OF POPS DURING THE LATE AFTERNOON
INTO THE EVENING.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
/ISSUED AT 350 AM EDT WED JUL 18 2012/
MODELS ARE MAINTAINING GOOD AGREEMENT THROUGH 48 HOURS. THE H5 LOW
OVER THE GA/FL BORDER WILL DRIFT INTO SOUTH/CENTRAL GEORGIA TODAY
AND THEN STALL AND DISSIPATE...OPENING UP INTO A WEAK TROUGH THAT
WILL REMAIN OVER THE CWA ON THURSDAY. THIS WILL CONTINUE TO BRING
ATLANTIC MOISTURE INTO THE CWA THROUGH THE SHORT TERM. WEAK UPPER
IMPULSES WILL CONTINUE ACROSS THE REGION THROUGH THE SHORT TERM AS
WELL...AND GIVEN THE AMOUNT OF COVERAGE OF CONVECTION OVER THE PAST
2 DAYS...SEE NO REASON WHY THERE WOULD BE LESS TODAY...THEREFORE
WILL INCREASE POPS TO LIKELY THIS AFTERNOON. MODELS ARE GIVING 50/60
POPS ON THURSDAY AND AGAIN SEE NO REASON TO GO LESS. AS FOR THE
NIGHTTIME PERIODS...AS WITH EARLY THIS MORNING...CONVECTION REMAINS
A POSSIBILITY. POCKETS OF WARM AIR COUPLED WITH THE UPPER
IMPULSES...WILL BE ENOUGH TO AID IN ISOLATED CONVECTION PAST
MIDNIGHT SO WILL CONTINUE WITH 20 POPS AFTER MIDNIGHT TONIGHT AND
THURSDAY NIGHT.
TEMPS ARE TRICKY AS AREAS THAT RECEIVE RAIN EARLY MAY STRUGGLE TO
GET OUT OF THE UPPER 80S...HOWEVER A DELAY IN RAIN OR NO RAIN AT ALL
COULD PUSH TEMPS INTO THE LOW AND MID 90S. WILL THEREFORE NOT STRAY
TOO FAR FROM GUIDANCE...WHICH IS VERY CLOSE TO PERSISTENCE...AND GO
WITH MAX TEMPS IN THE LOW TO MID 90S BOTH TODAY AND THURSDAY.
NIGHTTIME LOWS WILL REMAIN QUITE WARM AND MUGGY.
17
LONG TERM /FRIDAY THROUGH TUESDAY/...
/ISSUED AT 350 AM EDT WED JUL 18 2012/
EXTENDED PERIOD MODEL AGREEMENT DECENT WITH REMAINS OF UPPER LEVEL
LOW PRESSURE SYSTEM AND ASSOCIATED SURFACE TROUGH POSITIONED
ACROSS NORTH AND CENTRAL GEORGIA ON FRIDAY AS SURFACE LOW DEVELOPS
OVER THE CAROLINAS. THIS LOW WILL CONTINUALLY ADD MOISTURE TO AN
ALREADY MOIST ENVIRONMENT...AND EXPECTING GOOD PRECIP
COVERAGE...ESPECIALLY ACROSS NORTH GEORGIA. AS A RESULT...HAVE
GONE WITH LIKELY POPS NORTH...DIMINISHING TO GOOD CHANCE POPS
FURTHER SOUTH. BY SATURDAY...FRONTAL BOUNDARY SAGGING OUT OF THE
TENNESSEE VALLEY IS EXPECTED TO PUSH INTO NORTH AND CENTRAL
GEORGIA...KEEPING AMPLE MOISTURE ALIGNED ALONG THE FRONT. HAVE
GONE WITH LIKELY POPS ACROSS THE MIDDLE CWA...HIGHLIGHTING FRONT
PROGRESSION. THIS AREA OF LIKELY POPS IS SUBJECT TO CHANGE AS
SATURDAY APPROACHES DUE TO MODEL UNCERTAINTY WITH TIMING AND
LOCATION OF THE BOUNDARY. FOR FRIDAY AND SATURDAY...ENHANCED
CONVECTION IS EXPECTED TO BE COUPLED WITH DIURNAL HEATING...SO
HAVE DIMINISHED POPS SOMEWHAT INTO THE OVERNIGHT HOURS.
BY EARLY NEXT WEEK...HIGH PRESSURE OVER THE WESTERN ATLANTIC
ATTEMPTS TO NOSE BACK INTO THE REGION...WITH THE FLOW AROUND THE
RIDGE PULLING GULF MOISTURE INTO THE STATE. MEANWHILE...MODELS
SHOWING ANOTHER SHORTWAVE PUSHING INTO THE REGION WITH LEE SIDE
SURFACE TROUGH SETTING UP ALONG THE APPALACHIANS ASSOCIATED WITH
LOW PRESSURE OVER THE CANADIAN MARITIMES. AS A RESULT OF THESE
FEATURES...HAVE GENERALLY GONE WITH CHANCE POPS THROUGH THE
REMAINDER OF THE EXTENDED FORECAST PERIOD.
AS FOR TEMPERATURES...MODELS CONSISTENT WITH SHOWING COOLER 850MB
TEMPERATURES...SOMEWHERE IN THE 16.5 TO 17.5 RANGE...INTO THE
WEEKEND...AND WITH INCREASED PRECIP ACTIVITY AND PLENTY OF CLOUD
COVER...HAVE TENDED TOWARDS SLIGHTLY COOLER AFTERNOON HIGH
TEMPERATURES CLOSER TO SEASONAL NORMS. BY NEXT WEEK...WITH FLOW
OFF THE NORTHERN GULF ANTICIPATED BY MONDAY...850MB TEMPS WARM
2-2.5C...AND HAVE GONE WITH LOW 90 HIGHS MONDAY THROUGH WEDNESDAY.
WITH THE MOIST ENVIRONMENT PERSISTING THROUGH THE
WEEK...HEAVY RAIN STILL REMAINS A THREAT IN CONVECTION. FORECAST
SOUNDINGS SHOWING NEAR 2.0 INCH PWS INTO THE WEEKEND. QPF FOR
FRIDAY THROUGH SUNDAY MORNING IS EXPECTED TO BE WIDESPREAD 1-1.5
INCHES...WITH LOCALLY HEAVIER AMOUNTS.
31
AVIATION...
12Z UPDATE...
/ISSUED 729 AM EDT WED JUL 18 2012/
NEW CONVECTION ALONG THE AL/GA BORDER WEST OF ATL PROBABLY IN
RESPONSE TO OUTFLOW AND THE UPPER LOW. THIS COULD BE THE START OF
ANOTHER ACTIVE DAY AND WILL MAINTAIN PREDOMINANT TSRA OVER THE
FORECAST AREA BY 18Z WITH VCSH BEGINNING AROUND 14Z. CONVECTION
SHOULD DISSIPATE WITH THE LOSS OF DAYTIME HEATING TONIGHT. WINDS
WILL REMAIN ON THE WEST SIDE LESS THAN 10 KTS...BECOMING CALM
TONIGHT.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON TIMING OF CONVECTION.
HIGH ON ALL OTHER ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 71 93 73 / 60 40 60 30
ATLANTA 92 72 92 73 / 60 40 60 30
BLAIRSVILLE 85 67 85 69 / 60 40 60 30
CARTERSVILLE 92 70 92 71 / 60 40 60 30
COLUMBUS 94 73 93 73 / 60 40 60 30
GAINESVILLE 91 71 91 72 / 60 40 60 30
MACON 94 72 94 73 / 60 40 60 30
ROME 93 71 93 73 / 60 40 60 30
PEACHTREE CITY 92 71 92 71 / 60 40 60 30
VIDALIA 92 74 92 75 / 60 40 60 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...11
SHORT TERM...17
LONG TERM....31
AVIATION...17
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT WED JUL 18 2012
.DISCUSSION...
ISSUED 1045 AM CDT WED JUL 18 2012
AFTER LOOKING AT THE LATEST RUC...NAM12...4KM WRF MODELS WILL BE
UPDATING THE FORECAST TO INCREASE CHANCES OF SHOWERS AND
THUNDERSTORMS IN EASTERN IL. ALSO RAISED HIGHS A DEGREE OR TWO
ACROSS NORTHERN AREAS THIS AFTERNOON. HIGHS GENERALLY IN THE UPPER
90S TO NEAR 100 DEGREES THIS AFTERNOON WITH HEAT INDICES PEAKING
AROUND 105F...SO WILL CONTINUE THE HEAT ADVISORY ACROSS THE AREA
THROUGH 7 PM TODAY. VERY ISOLATED SHOWERS LATE THIS MORNING SE OF
DECATUR WHILE BRUNT OF CONVECTION SO FAR TODAY HAS BEEN OVER
SOUTHERN LAKE MI INTO LOWER MI AND NORTHERN INDIANA. THIS
CONVECTION CLOSER TIED TO A FRONTAL BOUNDARY OVER NORTHERN IL/IN
WHICH MODELS SLOWLY SAG THIS FRONT SOUTH TOWARD PEORIA THIS EVENING.
A STRONGER SHORT WAVE OVER THE DAKOTAS IS FORECAST TO TRACK ESE
ALONG THE BOUNDARY OVER NORTHERN IL TONIGHT KEEPING HIGHER CHANCES
OF SHOWERS AND THUNDERSTORMS JUST TO OUR NORTH. SPC EXPANDED
SLIGHT RISK OF SEVERE STORMS INTO CENTRAL IL FROM MID AFTERNOON
INTO THIS EVENING WHILE BEST CHANCE OF SEVERE STORMS WILL BE JUST
TO OUR NORTH.
HUETTL
&&
.AVIATION...
ISSUED 649 AM CDT WED JUL 18 2012...FOR THE 12Z TAFS
STORM CHANCES ACROSS CENTRAL ILLINOIS WILL INCREASE AFTER 18Z
BASED ON UPSTREAM EVENTS YESTERDAY NEAR THE APPROACHING COLD
FRONT... AND HRRR AND 4KM WRF OUTPUT FROM LAST NIGHT. TO DIMINISH
THE AMOUNT OF HOURS WITH THUNDER IN THE TAFS...WE KEPT ONLY A
MENTION OF VCSH FROM 18Z-24Z. THE LOCATION AND COVERAGE OF STORMS
WILL BY HIGHLY VARIABLE...AND STORM MOTION WILL BE VERY SLOW
OVERALL. SO THE CHANCE OF ANY STORMS HITTING THE TAF SITES
DIRECTLY MAY BE ON THE LOWER SIDE. THE CU FIELD FORMATIONS LATER
THIS MORNING SHOULD POINT TOWARD STORM LOCATIONS FOR THE 18Z TAFS.
PREVAIL WINDS WILL REMAIN SOUTHWEST BELOW 10KT AS THE COLD FRONT
TO THE NORTH REMAINS A CONVERGENT AREA DRAWING WINDS FROM THE
SOUTH. VISIBILITY WILL REMAIN VFR EXCEPT DURING THUNDERSTORMS. WE
KEPT VFR CONDITIONS FOR THE ENTIRE TAF PERIOD FOR NOW.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 259 AM CDT WED JUL 18 2012
LATEST UPPER AIR ANALYSIS FEATURES A LARGE RIDGE OF HIGH PRESSURE
DOMINATING THE CENTRAL AND SOUTHERN CONUS...WHILE A DEEP LOW SPINS
OVER NORTHERN QUEBEC. SHORT-WAVE TROUGH IS EVIDENT ON WATER VAPOR
IMAGERY EJECTING EASTWARD OUT OF THE NORTHERN ROCKIES. AT THE
SURFACE...MAIN BAROCLINIC ZONE EXTENDS FROM THE SOUTHERN GREAT
LAKES INTO THE NORTHERN PLAINS.
SHORT TERM...TODAY THROUGH FRIDAY
FRONT WILL MAKE SLOW PROGRESS SOUTHWARD TODAY...APPROACHING THE
I-74 CORRIDOR TOWARD EVENING. SCATTERED CONVECTION HAS MAINLY BEEN
OCCURRING ALONG AND NORTH OF THE BOUNDARY OVERNIGHT...AND THINK
THIS TREND WILL CONTINUE TODAY AS WELL. AS A RESULT...HIGHEST POPS
WILL BE CONCENTRATED ACROSS THE FAR NORTHERN KILX CWA THIS
AFTERNOON...WITH RAIN CHANCES DIMINISHING FURTHER SOUTHWEST AWAY
FROM THE BOUNDARY. WITH LITTLE OR NO UPPER SUPPORT...THINK AREAL
COVERAGE OF PRECIP WILL BE RATHER MINIMAL INITIALLY...WITH 30
PERCENT COVERAGE ALONG/NORTH OF I-74. GIVEN RELATIVELY HIGH
PRECIPITABLE WATER VALUES OF 1.50 TO 1.75 AND SLOW STORM
MOVEMENT...ANY CONVECTION THAT FIRES WILL BE CAPABLE OF PRODUCING
LOCALLY HEAVY RAINFALL IN A FEW SPOTS. OUTSIDE OF CONVECTION...IT
WILL BE ANOTHER VERY HOT DAY. HIGH TEMPS WILL BE HELD DOWN A FEW
DEGREES ACROSS THE NORTH DUE TO CLOUDS AND PRECIP...BUT WILL BE
JUST AS HOT OR EVEN HOTTER THAN YESTERDAY ACROSS THE SOUTH. HIGHS
WILL MAINLY BE IN THE MIDDLE TO UPPER 90S...WITH A FEW READINGS
AROUND 100 ALONG AND SOUTHWEST OF A JACKSONVILLE...TO ROBINSON
LINE. RESULTING HEAT INDEX VALUES WILL ONCE AGAIN BE AROUND 105
DEGREES...THEREFORE HEAT ADVISORY WILL CONTINUE THROUGH THE DAY.
SHORT-WAVE CURRENTLY PUSHING INTO THE WESTERN DAKOTAS WILL
APPROACH FROM THE NORTHWEST LATE TONIGHT INTO THURSDAY...PROVIDING
STRONGER SYNOPTIC LIFT AND SOMEWHAT BETTER AREAL COVERAGE OF
PRECIP. NAM12 AND SEVERAL DIFFERENT VERSIONS OF THE WRF ARE SUGGESTING
AN ORGANIZED CLUSTER OF STORMS MAY DEVELOP AHEAD OF THE ADVANCING
UPPER WAVE ACROSS IOWA TONIGHT...THEN SLIDE E/SE INTO NORTHERN
ILLINOIS THURSDAY MORNING. HAVE THEREFORE BUMPED POPS UP TO 40S
ACROSS THE N/NW CWA AFTER MIDNIGHT TONIGHT. MAIN QUESTION FURTHER
SOUTH ACROSS THE REMAINDER OF THE AREA WILL BE IF ADDITIONAL
CONVECTION CAN DEVELOP ALONG THE REMNANTS OF THIS FEATURE OR ALONG
ITS ACCOMPANYING OUTFLOW BOUNDARY THURSDAY AFTERNOON. MOST LIKELY
SCENARIO WOULD RESULT IN RE-DEVELOPMENT OF SCATTERED STORMS ACROSS
EAST-CENTRAL AND SOUTHEAST ILLINOIS. DAY 2 CONVECTIVE OUTLOOK FROM
SPC SUPPORTS THIS THEORY...AS AREAS ALONG/EAST OF I-55 ARE IN A
SLIGHT RISK FOR SEVERE. DUE TO UNCERTAINTIES CONCERNING MCS
DEVELOPMENT TONIGHT AND EVENTUAL LOCATION OF ITS OUTFLOW...WILL
CARRY 40 POPS ACROSS THE BOARD ON THURSDAY.
ONCE THE UPPER WAVE WORKS ITS WAY FURTHER EASTWARD...THE
STATIONARY FRONTAL BOUNDARY WILL GET PUSHED OUT OF THE AREA BY
LATE THURSDAY NIGHT OR FRIDAY MORNING. HAVE ADJUSTED POPS
ACCORDINGLY...WITH LINGERING LOW CHANCES EVERYWHERE THURSDAY
NIGHT...THEN JUST ACROSS THE FAR SOUTHEAST ON FRIDAY. AIRMASS
BEHIND THE FRONT WILL BE SLIGHTLY COOLER/LESS HUMID...RESULTING
IN HIGHS IN THE UPPER 80S AND LOWER 90S ON FRIDAY.
LONG TERM...SATURDAY THROUGH TUESDAY
STILL SOME QUESTION REGARDING EXACT POSITION OF PREVAILING UPPER
RIDGE IN THE EXTENDED...HOWEVER MODEL CONSENSUS KEEPS IT PRETTY
MUCH LOCKED IN PLACE ACROSS THE CENTRAL PLAINS. THIS WILL ENSURE
HEART OF HOTTEST AIRMASS STAYS WEST OF THE MISSISSIPPI RIVER
THROUGH EARLY NEXT WEEK. TEMPS FURTHER EAST ACROSS CENTRAL
ILLINOIS WILL STILL BE VERY HOT...BUT READINGS WILL REMAIN BELOW
100 DEGREES IN THE MIDDLE TO UPPER 90S. AS ANOTHER UPPER LOW MOVES
ACROSS CANADA AND DIGS INTO QUEBEC/NORTHERN NEW ENGLAND BY EARLY
NEXT WEEK...ANOTHER FRONT MAY GET SHUNTED SOUTHWARD TOWARD THE
MIDWEST. GIVEN STRENGTH OF RIDGE...AM SKEPTICAL TO BRING BOUNDARY
AND ASSOCIATED PRECIP CHANCES TOO FAR SOUTHWARD. AS A RESULT...AM
MAINTAINING A HOT/DRY FORECAST THROUGH TUESDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
918 AM CDT WED JUL 18 2012
.DISCUSSION...
558 AM CDT
LATEST RADAR/SURFACE OBS SHOW FRONTAL BOUNDARY STRETCHING FROM
NEAR DUBUQUE TO MORRIS TO NEAR VALPARAISO AT 530 AM WHICH HAD
SURGED SOUTHWARD OVER THE LAST HOUR. RADAR MOSAIC SHOWS ANOTHER
BOUNDARY FROM NEAR JANESVILLE TO CHICAGO. THIS BOUNDARY IS
COINCIDENT WITH SPOTTY CONVECTION NEAR MADISON AND A FEW SMALL
CELLS OVER SOUTHERN LAKE MICHIGAN. THE MAIN AREA OF CONVECTION
REMAINS MORE CLOSELY TIED TO THE MID LEVEL BAROCLINIC ZONE RUNNING
FROM THE TWIN CITIES INTO CENTRAL LOWER MICHIGAN. HIGH RES NEAR
TERM GUIDANCE SHOWS SOME INTERESTING SOLUTIONS IN TERMS OF
WINDS/BOUNDARY PLACEMENT INTO THE AFTERNOON. THE RAP AND THE HRRR
BOTH DEPICT THE CURRENT EXPANSE OF NORTHEAST WINDS BEHIND THE
FIRST BOUNDARY BUT THEN TURN WINDS ACROSS MUCH OF THE AREA
SOUTHWESTERLY THIS MORNING WITH A BOUNDARY SETTING UP FROM NEAR
ROCKFORD TO JOLIET TO RENSSELAER OR SO. THIS IS AN INTERESTING
PROGRESSION OF THINGS IF THIS INITIAL BOUNDARY WERE THE TRUE COLD
FRONT. LOCAL WRF SHOWS A SIMILAR THOUGH LESS PRONOUNCED TREND.
ASSUMING THIS BOUNDARY IS THE COLD FRONT IT IS POSSIBLE THAT IT
DOES MOVE BACK NORTHWARD INTO THE MIDDLE OF THE DAY IN RESPONSE TO
THE UPPER TROUGH MOVING TOWARD THE MID/UPPER MISSISSIPPI RIVER
VALLEY GIVEN THAT THE WESTERN EXTENT OF THE FRONT IS IN NORTHWEST
IOWA CLOSER TO WHERE THE UPPER TROUGH AXIS IS NOW. ANOTHER
SCENARIO IS THAT THE INITIAL BOUNDARY WAS SOME SORT OF SHALLOW
OUTFLOW WHICH MIXES OUT THIS MORNING AND THE MAIN FRONT IS THE
BOUNDARY CLOSER TO THE CHICAGO AREA DESCRIBED ABOVE. LOOKING AT
THE VAD WIND PROFILES FROM LOT AND MKX THEY SHOW SIMILAR DEPTHS OF
NORTHEAST WINDS SO IT SEEMS THAT THIS IS A LESS LIKELY SCENARIO.
WILL KEEP THE FORECAST MORE OR LESS AS-IS FOR NOW. OTHERWISE...SPOTTY
SHRA/TSRA DEVELOPMENT IS POSSIBLE BUT THE BULK OF THE NEAR TERM
ACTIVITY LOOKS TO REMAIN TO THE NORTH OVER THE NEXT FEW HOURS.
MDB
//PREV DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEW POINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* PSBL ISOLATED SHRA/TSRA BRUSHING TERMINALS THROUGH EARLY THIS AFTN.
* NE WINDS ARND 6 TO 8 KT THROUGH DURATION OF THE DAY.
BEACHLER
//DISCUSSION...UPDATED 12Z...
OUTFLOW FROM CENTRAL WI THUNDERSTORMS MOVES S OVER SE WI AND
SOUTHERN LAKE MI DURING THE LATE EVENING WITH ANOTHER OUTFLOW
DOING THE SAME DURING THE OVERNIGHT. APPEARS THAT ACTUAL SURFACE
FRONT HAS SLIPPED ACROSS FAR NE IL AROUND SUNRISE WITH RADAR
COMPOSITE SHOWING A BOUNDARY FROM AROUND DOWNTOWN CHI WNW ACROSS
THE WI BORDER N OF RFD AND THEN NORTHWESTWARD TO S OF MSN.
THUNDERSTORMS DEVELOPED IN S CENTRAL WI DURING THE PREDAWN N OF
THE BOUNDARY WHILE ELEVATED THUNDERSTORMS HAVE CONTINUED ACROSS
CENTRAL WI ANS ESE FROM GRB ACROSS CENTRAL LAKE MI AND CENTRAL
LOWER MI.
WESTERN EXTENT OF CENTRAL WI ACTIVITY IS SHOWING A GENERAL
DOWNWARD TREND AS ONE SHORT WAVE MOVES FROM E CENTRAL WI INTO W
CENTRAL WI. FURTHER UPSTREAM...A LARGER AREA OF THUNDERSTORMS WAS
MOVING FROM EASTERN SD INTO W CENTRAL AND SE MN AS A MORE WELL
DEFINED SHORT WAVE PUSHES ENE FROM THE WESTERN DAKOTAS.
SHORTER TERM CONCERN IS PROSPECTS OF THUNDERSTORMS ALONG/NEAR THE
SURFACE FRONT ACROSS NE AND FAR N CENTRAL IL INTO S CENTRAL WI.
MODELS GENERALLY SHOW THE FRONT MAKING A LITTLE FURTHER SOUTHWARD
PROGRESS THIS MORNING TO S OF THE CHI TERMINALS. DUE TO
UNCERTAINTY IN TS TO CONTINUE TO DEVELOP IN ASSOCIATION WITH THE
FRONT HAVE INCLUDED A VCTS IN THE TAFORS FOR THIS AFTERNOON AS
PROBABILITY OF ACTUALLY OCCURRING AND TERMINAL IS LOW.
IN THE OUTER PERIOD OF THE TAFORS CONCERN IS PROSPECTS FOR TS
WITH THE NORTHERN PLAINS SHORT WAVE. THE SHORT WAVE TROUGH AXIS
IS PROGGED TO REACH W CENTRAL WI...SE MN AND EASTERN IA BY 00Z
AND TO DROP ESE ACROSS SOUTHERN WI AS WELL AND NORTHERN AND W
CENTRAL OVERNIGHT. PERSISTENT POST FRONTAL CONVECTION THE LAST
COUPLE DAYS FROM THE NORTHERN PLAINS E ACROSS THE WESTERN GREAT
LAKES HAS BEEN OCCURRING WHERE ELEVATED CAPE HAS BEEN IN PLACE.
WITH MODELS SUGGESTING THAT THIS ELEVATED CAPE WILL SHIFT S WITH
TIME FEEL THERE IS A BETTER CHANCE OF SHOWERS AND THUNDERSHOWERS
AT THE LOCAL TERMINALS DURING THE LATE NIGHT AND EARLY MORNING
HOURS OF THU THUS THE PROB30 NEAR/AROUND SUNRISE THU.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN TS COVERAGE AND TIMING.
* MEDIUM CONFIDENCE IN ENDING OF TS/SHRA.
* LOW CONFIDENCE IN PRECIP DEVELOPMENT OVERNIGHT INTO EARLY THUR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...
FRI THROUGH TUE...VFR. NO SIG WX.
TRS
&&
.MARINE...
432 AM CDT
A COLD FRONT TRAILS FROM LOW PRESSURE OVER THE GULF OF ST.
LAWRENCE ACROSS SOUTHERN LOWER MI...FAR SOUTHERN LAKE MI AND FAR
NORTHERN IL EARLY THIS MORNING. THE COLD FRONT WILL CONTINUE TO
MOVE SLOWLY SOUTHWARD TODAY AND TONIGHT...EXTENDING FROM CENTRAL
IN ACROSS IL TO CENTRAL IA BY THURSDAY MORNING. HIGH PRESSURE OF
WILL BUILD SE FROM HUDSON BAY AND ONTARIO BEHIND THE COLD
FRONT...SPREADING ACROSS THE GREAT LAKES TODAY AND TONIGHT. LOW
PRESSURE WILL RIDE ALONG THE FRONTAL BOUNDARY FROM IA TO THE
UPPER OH VALLEY DURING THU WHILE A RIDGE OF HIGH PRESSURE REMAINS
OVER THE GREAT LAKES. LOW PRESSURE WILL BE TRACKING E FROM CENTRAL
CANADA TO HUDSON BAY THU NIGHT THROUGH FRI NIGHT WHILE THE RIDGE
OVER THE GREAT LAKES SHIFTS S OVER THE NORTHEASTERN U.S. AND THE
MIDWEST. THE COLD FRONT TRAILING FROM THE CANADIAN LOW WILL DROP S
ACROSS NORTHERN LAKE MI SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
723 AM CDT WED JUL 18 2012
.DISCUSSION...
558 AM CDT
LATEST RADAR/SURFACE OBS SHOW FRONTAL BOUNDARY STRETCHING FROM
NEAR DUBUQUE TO MORRIS TO NEAR VALPARAISO AT 530 AM WHICH HAD
SURGED SOUTHWARD OVER THE LAST HOUR. RADAR MOSAIC SHOWS ANOTHER
BOUNDARY FROM NEAR JANESVILLE TO CHICAGO. THIS BOUNDARY IS
COINCIDENT WITH SPOTTY CONVECTION NEAR MADISON AND A FEW SMALL
CELLS OVER SOUTHERN LAKE MICHIGAN. THE MAIN AREA OF CONVECTION
REMAINS MORE CLOSELY TIED TO THE MID LEVEL BAROCLINIC ZONE RUNNING
FROM THE TWIN CITIES INTO CENTRAL LOWER MICHIGAN. HIGH RES NEAR
TERM GUIDANCE SHOWS SOME INTERESTING SOLUTIONS IN TERMS OF
WINDS/BOUNDARY PLACEMENT INTO THE AFTERNOON. THE RAP AND THE HRRR
BOTH DEPICT THE CURRENT EXPANSE OF NORTHEAST WINDS BEHIND THE
FIRST BOUNDARY BUT THEN TURN WINDS ACROSS MUCH OF THE AREA
SOUTHWESTERLY THIS MORNING WITH A BOUNDARY SETTING UP FROM NEAR
ROCKFORD TO JOLIET TO RENSSELAER OR SO. THIS IS AN INTERESTING
PROGRESSION OF THINGS IF THIS INITIAL BOUNDARY WERE THE TRUE COLD
FRONT. LOCAL WRF SHOWS A SIMILAR THOUGH LESS PRONOUNCED TREND.
ASSUMING THIS BOUNDARY IS THE COLD FRONT IT IS POSSIBLE THAT IT
DOES MOVE BACK NORTHWARD INTO THE MIDDLE OF THE DAY IN RESPONSE TO
THE UPPER TROUGH MOVING TOWARD THE MID/UPPER MISSISSIPPI RIVER
VALLEY GIVEN THAT THE WESTERN EXTENT OF THE FRONT IS IN NORTHWEST
IOWA CLOSER TO WHERE THE UPPER TROUGH AXIS IS NOW. ANOTHER
SCENARIO IS THAT THE INITIAL BOUNDARY WAS SOME SORT OF SHALLOW
OUTFLOW WHICH MIXES OUT THIS MORNING AND THE MAIN FRONT IS THE
BOUNDARY CLOSER TO THE CHICAGO AREA DESCRIBED ABOVE. LOOKING AT
THE VAD WIND PROFILES FROM LOT AND MKX THEY SHOW SIMILAR DEPTHS OF
NORTHEAST WINDS SO IT SEEMS THAT THIS IS A LESS LIKELY SCENARIO.
WILL KEEP THE FORECAST MORE OR LESS AS-IS FOR NOW. OTHERWISE...SPOTTY
SHRA/TSRA DEVELOPMENT IS POSSIBLE BUT THE BULK OF THE NEAR TERM
ACTIVITY LOOKS TO REMAIN TO THE NORTH OVER THE NEXT FEW HOURS.
MDB
//PREV DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEW POINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
THREAT OF TS THIS AFTERNOON AND AGAIN EARLY THU MORNING.
TRS
//DISCUSSION...UPDATED 12Z...
OUTFLOW FROM CENTRAL WI THUNDERSTORMS MOVES S OVER SE WI AND
SOUTHERN LAKE MI DURING THE LATE EVENING WITH ANOTHER OUTFLOW
DOING THE SAME DURING THE OVERNIGHT. APPEARS THAT ACTUAL SURFACE
FRONT HAS SLIPPED ACROSS FAR NE IL AROUND SUNRISE WITH RADAR
COMPOSITE SHOWING A BOUNDARY FROM AROUND DOWNTOWN CHI WNW ACROSS
THE WI BORDER N OF RFD AND THEN NORTHWESTWARD TO S OF MSN.
THUNDERSTORMS DEVELOPED IN S CENTRAL WI DURING THE PREDAWN N OF
THE BOUNDARY WHILE ELEVATED THUNDERSTORMS HAVE CONTINUED ACROSS
CENTRAL WI ANS ESE FROM GRB ACROSS CENTRAL LAKE MI AND CENTRAL
LOWER MI.
WESTERN EXTENT OF CENTRAL WI ACTIVITY IS SHOWING A GENERAL
DOWNWARD TREND AS ONE SHORT WAVE MOVES FROM E CENTRAL WI INTO W
CENTRAL WI. FURTHER UPSTREAM...A LARGER AREA OF THUNDERSTORMS WAS
MOVING FROM EASTERN SD INTO W CENTRAL AND SE MN AS A MORE WELL
DEFINED SHORT WAVE PUSHES ENE FROM THE WESTERN DAKOTAS.
SHORTER TERM CONCERN IS PROSPECTS OF THUNDERSTORMS ALONG/NEAR THE
SURFACE FRONT ACROSS NE AND FAR N CENTRAL IL INTO S CENTRAL WI.
MODELS GENERALLY SHOW THE FRONT MAKING A LITTLE FURTHER SOUTHWARD
PROGRESS THIS MORNING TO S OF THE CHI TERMINALS. DUE TO
UNCERTAINTY IN TS TO CONTINUE TO DEVELOP IN ASSOCIATION WITH THE
FRONT HAVE INCLUDED A VCTS IN THE TAFORS FOR THIS AFTERNOON AS
PROBABILITY OF ACTUALLY OCCURRING AND TERMINAL IS LOW.
IN THE OUTER PERIOD OF THE TAFORS CONCERN IS PROSPECTS FOR TS
WITH THE NORTHERN PLAINS SHORT WAVE. THE SHORT WAVE TROUGH AXIS
IS PROGGED TO REACH W CENTRAL WI...SE MN AND EASTERN IA BY 00Z
AND TO DROP ESE ACROSS SOUTHERN WI AS WELL AND NORTHERN AND W
CENTRAL OVERNIGHT. PERSISTENT POST FRONTAL CONVECTION THE LAST
COUPLE DAYS FROM THE NORTHERN PLAINS E ACROSS THE WESTERN GREAT
LAKES HAS BEEN OCCURRING WHERE ELEVATED CAPE HAS BEEN IN PLACE.
WITH MODELS SUGGESTING THAT THIS ELEVATED CAPE WILL SHIFT S WITH
TIME FEEL THERE IS A BETTER CHANCE OF SHOWERS AND THUNDERSHOWERS
AT THE LOCAL TERMINALS DURING THE LATE NIGHT AND EARLY MORNING
HOURS OF THU THUS THE PROB30 NEAR/AROUND SUNRISE THU.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
HIGH CONFIDENCE IN WIND FORECAST.
MODERATE CONFIDENCE IN TS IN THE AREA THIS AFTERNOON BUT LOW
CONFIDENCE WILL DIRECTLY AFFECT TERMINALS.
MODERATE CONFIDENCE IS PERIOD OF SHRA AND TSRA OVERNIGHT INTO
EARLY THU MORNING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...
FRI THROUGH TUE...VFR. NO SIG WX.
TRS
&&
.MARINE...
432 AM CDT
A COLD FRONT TRAILS FROM LOW PRESSURE OVER THE GULF OF ST.
LAWRENCE ACROSS SOUTHERN LOWER MI...FAR SOUTHERN LAKE MI AND FAR
NORTHERN IL EARLY THIS MORNING. THE COLD FRONT WILL CONTINUE TO
MOVE SLOWLY SOUTHWARD TODAY AND TONIGHT...EXTENDING FROM CENTRAL
IN ACROSS IL TO CENTRAL IA BY THURSDAY MORNING. HIGH PRESSURE OF
WILL BUILD SE FROM HUDSON BAY AND ONTARIO BEHIND THE COLD
FRONT...SPREADING ACROSS THE GREAT LAKES TODAY AND TONIGHT. LOW
PRESSURE WILL RIDE ALONG THE FRONTAL BOUNDARY FROM IA TO THE
UPPER OH VALLEY DURING THU WHILE A RIDGE OF HIGH PRESSURE REMAINS
OVER THE GREAT LAKES. LOW PRESSURE WILL BE TRACKING E FROM CENTRAL
CANADA TO HUDSON BAY THU NIGHT THROUGH FRI NIGHT WHILE THE RIDGE
OVER THE GREAT LAKES SHIFTS S OVER THE NORTHEASTERN U.S. AND THE
MIDWEST. THE COLD FRONT TRAILING FROM THE CANADIAN LOW WILL DROP S
ACROSS NORTHERN LAKE MI SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
649 AM CDT WED JUL 18 2012
.DISCUSSION...
ISSUED 259 AM CDT WED JUL 18 2012
LATEST UPPER AIR ANALYSIS FEATURES A LARGE RIDGE OF HIGH PRESSURE
DOMINATING THE CENTRAL AND SOUTHERN CONUS...WHILE A DEEP LOW SPINS
OVER NORTHERN QUEBEC. SHORT-WAVE TROUGH IS EVIDENT ON WATER VAPOR
IMAGERY EJECTING EASTWARD OUT OF THE NORTHERN ROCKIES. AT THE
SURFACE...MAIN BAROCLINIC ZONE EXTENDS FROM THE SOUTHERN GREAT
LAKES INTO THE NORTHERN PLAINS.
SHORT TERM...TODAY THROUGH FRIDAY
FRONT WILL MAKE SLOW PROGRESS SOUTHWARD TODAY...APPROACHING THE
I-74 CORRIDOR TOWARD EVENING. SCATTERED CONVECTION HAS MAINLY BEEN
OCCURRING ALONG AND NORTH OF THE BOUNDARY OVERNIGHT...AND THINK
THIS TREND WILL CONTINUE TODAY AS WELL. AS A RESULT...HIGHEST POPS
WILL BE CONCENTRATED ACROSS THE FAR NORTHERN KILX CWA THIS
AFTERNOON...WITH RAIN CHANCES DIMINISHING FURTHER SOUTHWEST AWAY
FROM THE BOUNDARY. WITH LITTLE OR NO UPPER SUPPORT...THINK AREAL
COVERAGE OF PRECIP WILL BE RATHER MINIMAL INITIALLY...WITH 30
PERCENT COVERAGE ALONG/NORTH OF I-74. GIVEN RELATIVELY HIGH
PRECIPITABLE WATER VALUES OF 1.50 TO 1.75 AND SLOW STORM
MOVEMENT...ANY CONVECTION THAT FIRES WILL BE CAPABLE OF PRODUCING
LOCALLY HEAVY RAINFALL IN A FEW SPOTS. OUTSIDE OF CONVECTION...IT
WILL BE ANOTHER VERY HOT DAY. HIGH TEMPS WILL BE HELD DOWN A FEW
DEGREES ACROSS THE NORTH DUE TO CLOUDS AND PRECIP...BUT WILL BE
JUST AS HOT OR EVEN HOTTER THAN YESTERDAY ACROSS THE SOUTH. HIGHS
WILL MAINLY BE IN THE MIDDLE TO UPPER 90S...WITH A FEW READINGS
AROUND 100 ALONG AND SOUTHWEST OF A JACKSONVILLE...TO ROBINSON
LINE. RESULTING HEAT INDEX VALUES WILL ONCE AGAIN BE AROUND 105
DEGREES...THEREFORE HEAT ADVISORY WILL CONTINUE THROUGH THE DAY.
SHORT-WAVE CURRENTLY PUSHING INTO THE WESTERN DAKOTAS WILL
APPROACH FROM THE NORTHWEST LATE TONIGHT INTO THURSDAY...PROVIDING
STRONGER SYNOPTIC LIFT AND SOMEWHAT BETTER AREAL COVERAGE OF
PRECIP. NAM12 AND SEVERAL DIFFERENT VERSIONS OF THE WRF ARE SUGGESTING
AN ORGANIZED CLUSTER OF STORMS MAY DEVELOP AHEAD OF THE ADVANCING
UPPER WAVE ACROSS IOWA TONIGHT...THEN SLIDE E/SE INTO NORTHERN
ILLINOIS THURSDAY MORNING. HAVE THEREFORE BUMPED POPS UP TO 40S
ACROSS THE N/NW CWA AFTER MIDNIGHT TONIGHT. MAIN QUESTION FURTHER
SOUTH ACROSS THE REMAINDER OF THE AREA WILL BE IF ADDITIONAL
CONVECTION CAN DEVELOP ALONG THE REMNANTS OF THIS FEATURE OR ALONG
ITS ACCOMPANYING OUTFLOW BOUNDARY THURSDAY AFTERNOON. MOST LIKELY
SCENARIO WOULD RESULT IN RE-DEVELOPMENT OF SCATTERED STORMS ACROSS
EAST-CENTRAL AND SOUTHEAST ILLINOIS. DAY 2 CONVECTIVE OUTLOOK FROM
SPC SUPPORTS THIS THEORY...AS AREAS ALONG/EAST OF I-55 ARE IN A
SLIGHT RISK FOR SEVERE. DUE TO UNCERTAINTIES CONCERNING MCS
DEVELOPMENT TONIGHT AND EVENTUAL LOCATION OF ITS OUTFLOW...WILL
CARRY 40 POPS ACROSS THE BOARD ON THURSDAY.
ONCE THE UPPER WAVE WORKS ITS WAY FURTHER EASTWARD...THE
STATIONARY FRONTAL BOUNDARY WILL GET PUSHED OUT OF THE AREA BY
LATE THURSDAY NIGHT OR FRIDAY MORNING. HAVE ADJUSTED POPS
ACCORDINGLY...WITH LINGERING LOW CHANCES EVERYWHERE THURSDAY
NIGHT...THEN JUST ACROSS THE FAR SOUTHEAST ON FRIDAY. AIRMASS
BEHIND THE FRONT WILL BE SLIGHTLY COOLER/LESS HUMID...RESULTING
IN HIGHS IN THE UPPER 80S AND LOWER 90S ON FRIDAY.
LONG TERM...SATURDAY THROUGH TUESDAY
STILL SOME QUESTION REGARDING EXACT POSITION OF PREVAILING UPPER
RIDGE IN THE EXTENDED...HOWEVER MODEL CONSENSUS KEEPS IT PRETTY
MUCH LOCKED IN PLACE ACROSS THE CENTRAL PLAINS. THIS WILL ENSURE
HEART OF HOTTEST AIRMASS STAYS WEST OF THE MISSISSIPPI RIVER
THROUGH EARLY NEXT WEEK. TEMPS FURTHER EAST ACROSS CENTRAL
ILLINOIS WILL STILL BE VERY HOT...BUT READINGS WILL REMAIN BELOW
100 DEGREES IN THE MIDDLE TO UPPER 90S. AS ANOTHER UPPER LOW MOVES
ACROSS CANADA AND DIGS INTO QUEBEC/NORTHERN NEW ENGLAND BY EARLY
NEXT WEEK...ANOTHER FRONT MAY GET SHUNTED SOUTHWARD TOWARD THE
MIDWEST. GIVEN STRENGTH OF RIDGE...AM SKEPTICAL TO BRING BOUNDARY
AND ASSOCIATED PRECIP CHANCES TOO FAR SOUTHWARD. AS A RESULT...AM
MAINTAINING A HOT/DRY FORECAST THROUGH TUESDAY.
BARNES
&&
.AVIATION...
ISSUED 649 AM CDT WED JUL 18 2012...FOR THE 12Z TAFS
STORM CHANCES ACROSS CENTRAL ILLINOIS WILL INCREASE AFTER 18Z
BASED ON UPSTREAM EVENTS YESTERDAY NEAR THE APPROACHING COLD
FRONT... AND HRRR AND 4KM WRF OUTPUT FROM LAST NIGHT. TO DIMINISH
THE AMOUNT OF HOURS WITH THUNDER IN THE TAFS...WE KEPT ONLY A
MENTION OF VCSH FROM 18Z-24Z. THE LOCATION AND COVERAGE OF STORMS
WILL BY HIGHLY VARIABLE...AND STORM MOTION WILL BE VERY SLOW
OVERALL. SO THE CHANCE OF ANY STORMS HITTING THE TAF SITES
DIRECTLY MAY BE ON THE LOWER SIDE. THE CU FIELD FORMATIONS LATER
THIS MORNING SHOULD POINT TOWARD STORM LOCATIONS FOR THE 18Z TAFS.
PREVAIL WINDS WILL REMAIN SOUTHWEST BELOW 10KT AS THE COLD FRONT
TO THE NORTH REMAINS A CONVERGENT AREA DRAWING WINDS FROM THE
SOUTH. VISIBILITY WILL REMAIN VFR EXCEPT DURING THUNDERSTORMS. WE
KEPT VFR CONDITIONS FOR THE ENTIRE TAF PERIOD FOR NOW.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
602 AM CDT WED JUL 18 2012
.DISCUSSION...
558 AM CDT
LATEST RADAR/SURFACE OBS SHOW FRONTAL BOUNDARY STRETCHING FROM
NEAR DUBUQUE TO MORRIS TO NEAR VALPARAISO AT 530 AM WHICH HAD
SURGED SOUTHWARD OVER THE LAST HOUR. RADAR MOSAIC SHOWS ANOTHER
BOUNDARY FROM NEAR JANESVILLE TO CHICAGO. THIS BOUNDARY IS
COINCIDENT WITH SPOTTY CONVECTION NEAR MADISON AND A FEW SMALL
CELLS OVER SOUTHERN LAKE MICHIGAN. THE MAIN AREA OF CONVECTION
REMAINS MORE CLOSELY TIED TO THE MID LEVEL BAROCLINIC ZONE RUNNING
FROM THE TWIN CITIES INTO CENTRAL LOWER MICHIGAN. HIGH RES NEAR
TERM GUIDANCE SHOWS SOME INTERESTING SOLUTIONS IN TERMS OF
WINDS/BOUNDARY PLACEMENT INTO THE AFTERNOON. THE RAP AND THE HRRR
BOTH DEPICT THE CURRENT EXPANSE OF NORTHEAST WINDS BEHIND THE
FIRST BOUNDARY BUT THEN TURN WINDS ACROSS MUCH OF THE AREA
SOUTHWESTERLY THIS MORNING WITH A BOUNDARY SETTING UP FROM NEAR
ROCKFORD TO JOLIET TO RENSSELAER OR SO. THIS IS AN INTERESTING
PROGRESSION OF THINGS IF THIS INITIAL BOUNDARY WERE THE TRUE COLD
FRONT. LOCAL WRF SHOWS A SIMILAR THOUGH LESS PRONOUNCED TREND.
ASSUMING THIS BOUNDARY IS THE COLD FRONT IT IS POSSIBLE THAT IT
DOES MOVE BACK NORTHWARD INTO THE MIDDLE OF THE DAY IN RESPONSE TO
THE UPPER TROUGH MOVING TOWARD THE MID/UPPER MISSISSIPPI RIVER
VALLEY GIVEN THAT THE WESTERN EXTENT OF THE FRONT IS IN NORTHWEST
IOWA CLOSER TO WHERE THE UPPER TROUGH AXIS IS NOW. ANOTHER
SCENARIO IS THAT THE INITIAL BOUNDARY WAS SOME SORT OF SHALLOW
OUTFLOW WHICH MIXES OUT THIS MORNING AND THE MAIN FRONT IS THE
BOUNDARY CLOSER TO THE CHICAGO AREA DESCRIBED ABOVE. LOOKING AT
THE VAD WIND PROFILES FROM LOT AND MKX THEY SHOW SIMILAR DEPTHS OF
NORTHEAST WINDS SO IT SEEMS THAT THIS IS A LESS LIKELY SCENARIO.
WILL KEEP THE FORECAST MORE OR LESS AS-IS FOR NOW. OTHERWISE...SPOTTY
SHRA/TSRA DEVELOPMENT IS POSSIBLE BUT THE BULK OF THE NEAR TERM
ACTIVITY LOOKS TO REMAIN TO THE NORTH OVER THE NEXT FEW HOURS.
MDB
&&
.PREV DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEW POINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.CLIMATE...
305 PM CDT...
RECORDS FOR TODAY JULY 17TH ARE AS FOLLOWS:
CHICAGO RECORD HIGH: 100 /1942/
ROCKFORD RECORD HIGH: 104 /1936/
CHICAGO RECORD WARM LOW: 80 /1878/
ROCKFORD RECORD WARM LOW: 76 /1982/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
TIMING OF ARRIVAL COLD FRONTAL PASSAGE ACROSS TERMINALS.
POTENTIAL FOR CONVECTIVE ACTIVITY ALONG AND AHEAD OF COLD FRONT
TODAY AS WELL AS ELEVATED CONVECTION POST FRONTAL DURING THE
OVERNIGHT.
TRS
//DISCUSSION...UPDATED 06Z...
KLOT...TORD AND TMDW RADARS SHOWED THE OUTFLOW BOUNDARY THAT
ORIGINATED FROM THUNDERSTORMS OVER E CENTRAL WI AND CENTRAL LAKE
MI CONTINUED TO DROP S DURING THE EVENING FROM NORTHEASTERN TO
SOUTHEASTERN COOK CO. BURNHAM HARBOR AND MDW BRIEFLY SHOWING
LIGHT N-NNE WINDS 04-05Z BUT HAVE ALREADY SWITCHED BACK TO A
LIGHT SW FLOW.
COLD FRONT AT 05Z WAS LOCATED E-W ACROSS SOUTHERN LOWER MI AND
SOUTHERN LAKE MI TO FAR SOUTHEASTERN WI THEN CURVED WNW TO
SOUTHERN MN. MAIN AREA OF CONVECTION WAS FROM E CENTRAL WI ESE
ACROSS LAKE MI TO W CENTRAL LOWER MI. THIS WAS POST FRONTAL WHERE
ELEVATED CAPE STILL IN PLACE AS A SHORT WAVE MOVED ESE FROM MN
ACROSS CENTRAL WI DURING TUE AFTERNOON AND EVENING.
LATEST MODEL RUNS HAVE THE COLD FRONT SINKING S ACROSS THE STATE
LINE DURING THE OVERNIGHT AND EARLY MORNING...AND PUSHING ACROSS
THE CHI AREA TERMINALS AROUND 13Z. WITH ONLY A HOUR OR TWO OF
HEATING BEFORE THE ARRIVAL AND A LACK OF MID OR UPPER LEVEL
SUPPORT TO NOT SEE ANY SIGNIFICANT POTENTIAL FOR CONVECTIVE
DEVELOPMENT BEFORE THE FRONT PASSES BY THE TERMINALS.
UPSTREAM...A FEW SHORT NARROW LINE SEGMENTS OF SHOWERS AND
THUNDERSTORMS WERE OCCURRING FROM W CENTRAL WI ACROSS CENTRAL MN
TO NW SD. THE SE WERE OCCURRING ALONG THE LEADING EDGE OF THE
TIGHT 850HPA THERMAL GRADIENT. THIS THERMAL GRADIENT DOES MIGRATE
SOUTHWARD TODAY BUT MODELS SHOW IT TO MOVING INTO FAR NE IL TIL
THIS AFTERNOON. CANNOT TOTALLY RULE OUT AN ISOLATED OR WIDELY
SCATTERED THUNDERSTORMS ASSOCIATED WITH THIS BAROCLINIC ZONE
DURING THE AFTERNOON AT OR IN THE VC OF THE CHI TERMINALS BUT
LOCATIONS ALONG THE COLD FRONT LOOK TO BE BETTER CANDIDATES FOR
SEEING SIGNIFICANT CONVECTION LATER TODAY WHERE LOW LEVEL DEW
POINT POOLING AND CONVERGENCE MAXIMIZE CAPE VALUES FROM SE TO S
TO SW AND W OF THE CHI AREA.
FURTHER UP STEAM...MORE SHOWERS AND THUNDERSTORMS WERE OCCURRING
IN CENTRAL SD AS A MORE WELL DEFINED SHORT WAVE TROUGH WAS MOVING
E FROM WESTERN SD AND NEB. THE SHORT WAVE TROUGH AXIS IS PROGGED
TO REACH W CENTRAL WI...SE MN AND EASTERN IA BY 00Z AND TO DROP
ESE ACROSS SOUTHERN WI AS WELL AND NORTHERN AND W CENTRAL
OVERNIGHT. THIS WILL BRING A CHANCE OF SHOWERS AND THUNDERSHOWERS
TO THE LOCAL TERMINALS DURING THE LATE NIGHT AND EARLY MORNING
HOURS OF THU.
WITH THE COLD FRONT SLIPPING S OF THE TERMINALS DURING THE FIRST
PART OF TODAY AND THE SOUTHERN PORTION OF A LARGE RIDGE OF HIGH
PRESSURE BUILDING SE OVER THE UPPER GREAT LAKES LOCAL WINDS
EXPECTED TO BE OUT OF THE NE THOUGH GENERALLY AOB 10KT AS
GRADIENT BEHIND THE FRONT IS SHOWN TO BE PRETTY WEAK.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
HIGH CONFIDENCE IN FORECAST WIND TRENDS.
MODERATE CONFIDENCE IS CONVECTIVE ACTIVITY TO NOT AFFECT
IMMEDIATE CHI VC TODAY.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHC TSRA...ELSE VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHC TSRA...ELSE VFR.
BMD
&&
.MARINE...
432 AM CDT
A COLD FRONT TRAILS FROM LOW PRESSURE OVER THE GULF OF ST.
LAWRENCE ACROSS SOUTHERN LOWER MI...FAR SOUTHERN LAKE MI AND FAR
NORTHERN IL EARLY THIS MORNING. THE COLD FRONT WILL CONTINUE TO
MOVE SLOWLY SOUTHWARD TODAY AND TONIGHT...EXTENDING FROM CENTRAL
IN ACROSS IL TO CENTRAL IA BY THURSDAY MORNING. HIGH PRESSURE OF
WILL BUILD SE FROM HUDSON BAY AND ONTARIO BEHIND THE COLD
FRONT...SPREADING ACROSS THE GREAT LAKES TODAY AND TONIGHT. LOW
PRESSURE WILL RIDE ALONG THE FRONTAL BOUNDARY FROM IA TO THE
UPPER OH VALLEY DURING THU WHILE A RIDGE OF HIGH PRESSURE REMAINS
OVER THE GREAT LAKES. LOW PRESSURE WILL BE TRACKING E FROM CENTRAL
CANADA TO HUDSON BAY THU NIGHT THROUGH FRI NIGHT WHILE THE RIDGE
OVER THE GREAT LAKES SHIFTS S OVER THE NORTHEASTERN U.S. AND THE
MIDWEST. THE COLD FRONT TRAILING FROM THE CANADIAN LOW WILL DROP S
ACROSS NORTHERN LAKE MI SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
917 AM CDT WED JUL 18 2012
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 917 AM CDT WED JUL 18 2012
THE 18.12Z 250 HPA SYNOPTIC MAP SHOWED A 50 TO 60 KT CYCLONIC CIRCULATION
STILL ACROSS THE PACIFIC NORTHWEST AND EXTENDING SOUTHWARD ACROSS NORTHERN
CALIFORNIA. A ~100 KT JET STREAK WAS LOCATED ACROSS SOUTHEASTERN CANADA.
OTHERWISE, FLOW AT JET LEVEL WAS FAIRLY WEAK ACROSS MOST OF THE COUNTRY
AS ONE WOULD EXPECT DURING THE SUMMER. @ 500 HPA, AN ABNORMALLY STRONG
569 DM LOW WAS SPINNING ACROSS NORTHWESTERN CALIFORNIA. A COLD POOL
OF -17 DEG C WAS ASSOCIATED WITH SAID FEATURE. TWO 590 DM HIGH PRESSURE
CENTERS WERE LOCATED CLOSER TO KANSAS. ONE ACROSS THE SOUTHERN ROCKIES
AND THE OTHER ACROSS THE OZARKS. A WEAK CYCLONE WAS FOUND ACROSS GEORGIA.
AT 700/850 HPA, THE WARM/DRY PLUME WAS STILL OBVIOUS ACROSS THE PLAINS
WITH 700 HPA TEMPERATURES RUNNING IN THE 12 TO 13 DEG C RANGE AND 850
HPA TEMPERATURES IN THE 25 TO 26 DEG C RANGE. AT THE SFC, A TROUGH AXIS
WAS LOCATED ACROSS KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 226 AM CDT WED JUL 18 2012
CLOUDS INCREASING IN AREAL COVERAGE EARLY THIS MORNING NEAR A
500MB DEFORMATION ZONE/COL BASED ON 00Z ANALYSIS. ALL THE MODELS
PICK UP ON THIS FEATHER AND INCREASE 700MB RELATIVE HUMIDITY
VALUES EARLY THIS MORNING. THE HRRR EVEN SUGGESTS SOME LIGHT
PRECIPITATION WILL BE POSSIBLE. BASED ON LATEST RADAR TRENDS WILL
FOLLOW THE HRRR AND INTRODUCE SOME LIGHT PRECIPITATION EARLY THIS
MORNING IN SOUTH CENTRAL KANSAS.
AN UPPER LEVEL RIDGE WILL THEN BUILD ACROSS THE CENTRAL AND
NORTHERN ROCKIES LATER TODAY AS THE CENTER OF THIS HIGH, LOCATED
OVER COLORADO, MOVES VERY LITTLE. MODELS REMAIN IN GOOD AGREEMENT
IN MOVING A SURFACE BOUNDARY ACROSS WESTERN KANSAS DURING THE EARLY
MORNING HOURS AND BY THE EARLY AFTERNOON THIS BOUNDARY IS EXPECTED
TO EXTEND FROM HAYS TO GARDEN CITY TO NEAR ELKHART. FORECAST MODEL
SOUNDINGS NEAR THIS SURFACE TROUGH INDICATED SOME MID LEVEL
INSTABILITY AND MOISTURE IN THE 700-600MB LEVEL WILL BE PRESENT AS
AN UPPER LEVEL DISTURBANCE ROTATES AROUND THE UPPER HIGH AND
CROSSES INTO WESTERN KANSAS. GIVEN THE ESTIMATED TIMING OF THIS
UPPER LEVEL DISTURBANCE ALONG WITH WHERE THE BETTER THE LATE DAY
INSTABILITY IS EXPECTED WILL INCREASE THE PRECIPITATION CHANCES
NEAR THE SURFACE BOUNDARY LATE THIS AFTERNOON...ESPECIALLY IN
NORTH CENTRAL KANSAS. THE INVERTED V TYPE OF SOUNDINGS CONTINUE TO
SUGGEST THE PREVIOUS SHIFT HAD THE RIGHT IDEA WITH THE PRIMARY
HAZARD BEING WINDS GUSTY UP TO 45 MPH AND CLOUD TO GROUND
LIGHTNING.
CLOUD COVER THIS AFTERNOON WILL PLAY AN IMPORTANT ROLE ON
TEMPERATURES TODAY. MIXING DOWN THE NAM AND ECMWF 850MB
TEMPERATURES AT 00Z THURSDAY SUGGESTS HIGHS WILL BE MAINLY IN THE
100 TO 104 DEGREE RANGE. INCREASING AFTERNOON CLOUDS AHEAD OF THE
UPPER LEVEL DISTURBANCE HOWEVER MAY RESULT IN KEEPING TEMPERATURES
SEVERAL DEGREES COOLER THAN THIS. AT THIS TIME THERE STILL APPEARS
TO BE A DECENT AMOUNT OF AFTERNOON SUNSHINE SO WILL CONTINUE TO
TREND TOWARDS THE WARMER NAM/ECMWF SOLUTION WHICH HAPPENS TO BE
VERY SIMILAR TO THE PREVIOUS FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 337 AM CDT WED JUL 18 2012
THE GENERAL UPPER-LEVEL PATTERN THROUGH JULY 25TH WILL FEATURE
UPPER-LEVEL RIDGING OVER KANSAS AND UPPER-LEVEL SHORTWAVE TROUGHS
POSITIONED FAR TO THE NORTH AND WEST OF KANSAS ACROSS THE NORTHERN
ROCKIES AND SOUTHERN CANADA. HOT WEATHER WILL PERSIST THROUGHOUT THIS
PERIOD. 500MB HEIGHTS ARE PROGGED TO RISE THIS WEEK FROM 589 TO
596 DM AND THIS IMPLIES LOW TO MID-LEVEL WARMING GIVEN THAT SEA
LEVEL PRESSURE VALUES ARE EXPECTED TO CHANGE VERY LITTLE. SO HIGHS
SHOULD BE WELL OVER 100 FOR MOST OF SOUTHWEST KANSAS, EXCEPT
CLOSER TO 100 NEAR THE COLORADO BORDER. SOME READINGS NEAR
107-109F ARE POSSIBLE BY MONDAY AND TUESDAY.
THE SLOW MOVING FRONTAL BOUNDARY MENTIONED IN THE SHORT TERM DISCUSSION
THAT IS CURRENTLY OVER NORTHWEST KANSAS WILL STALL OUT IN THE MIDDLE
OF THE UPPER-LEVEL RIDGE AXIS SOMEWHERE OVER SOUTHWEST KANSAS ON
THURSDAY. THEREFORE, THERE IS A SMALL CHANCE FOR THUNDERSTORMS
WHEREVER THIS BOUNDARY STALLS OUT AND THIS IS HARD TO PINPOINT AT
THIS TIME. SO SMALL CHANCES FOR STORMS WERE INTRODUCED FOR MUCH OF
THE FORECAST AREA. EVEN THOUGH THE LOW-LEVEL MOISTURE IS MIXING
OUT IN THE HOT PLUME AS IT TRIES TO MOVE NORTHWARD INTO THE
PLAINS, SOME SURFACE BASED CAPE BETWEEN 400 AND 800 J/KG, ALONG
WITH MODEST LOW-LEVEL CONVERGENCE AND STRONG SURFACE HEATING MAY
BE ENOUGH TO INITIATE A FEW HIGH BASED THUNDERSTORMS. GIVEN THE
LOW CAPE VALUES, VERY LOW VERTICAL WIND SHEAR AND HIGH CLOUD
BASES, THE MAIN THREAT WITH THESE STORMS IS GUSTY WINDS AS HIGH AS
50 MPH AS WELL AS ANY CLOUD TO GROUND LIGHTNING.
AFTER THURSDAY, THERE IS LITTLE IN THE WAY OF HOPE FOR THUNDERSTORMS
THROUGH JULY 25TH GIVEN THE AFOREMENTIONED STRONG UPPER-LEVEL
RIDGING AND ABSENCE OF FRONTS. HOWEVER, THE LONGER RANGE MODELS
ARE OFTEN UNABLE TO RESOLVE SMALLER SCALE BOUNDARIES THAT COULD
SERVE TO INITIATE ISOLATED THUNDERSTORMS. BUT IT IS PROBABLY SAFE
TO SAY THAT WIDESPREAD BENEFICIAL RAINS ARE HIGHLY UNLIKELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 657 AM CDT WED JUL 18 2012
LIGHT SOUTHWESTERLY WINDS WILL BECOME LIGHT AS A WEAK FRONT STALLS OUT
ACROSS THE TAF SITES THIS AFTERNOON. ISOLATED THUNDERSTORMS MAY
DEVELOP AFTER 21Z ALONG THIS FRONT IN VICINITY OF THE TAF SITES.
VFR CONDITIONS WILL PREVAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 72 103 74 / 10 20 20 20
GCK 100 69 101 73 / 20 20 20 10
EHA 98 70 100 72 / 10 20 0 0
LBL 101 69 101 73 / 10 20 10 0
HYS 104 73 106 76 / 20 20 20 20
P28 104 73 105 77 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
659 AM CDT WED JUL 18 2012
...UPDATED FOR AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1211 AM CDT WED JUL 18 2012
A -17C 500MB LOW WAS LOCATED OVER NORTHERN CALIFORNIA AS OF 00Z
WEDNESDAY. STRONGEST 250MB WINDS AROUND THIS UPPER LOW EXTENDED FROM
THE BASE OF THIS UPPER LOW NORTHEASTWARD INTO EASTERN
OREGON/SOUTHWEST IDAHO. AN UPPER LEVEL RIDGE EXTENDED FROM NORTHERN
NEW MEXICO INTO EASTERN WYOMING AT 00Z WEDNESDAY WITH THE CENTER
OF THIS ANTICYCLONIC FLOW APPEARING TO BE LOCATED OVER SOUTHERN
COLORADO BASED ON 500MB ANALYSIS. A TROUGH OF LOW PRESSURE AT THE
SURFACE AT 01Z EXTENDED FROM NORTH CENTRAL KANSAS INTO SOUTHEAST
COLORADO. THE LATEST RADAR LOOP, AS OF 05Z, INDICATED THAT SEVERAL
OUTFLOW BOUNDARIES FROM THE CONVECTION THAT DEVELOPED EARLIER THIS
EVENING NEAR THIS BOUNDARY WERE NOW LOCATED ACROSS WESTERN AND
NORTH CENTRAL KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 226 AM CDT WED JUL 18 2012
CLOUDS INCREASING IN AREAL COVERAGE EARLY THIS MORNING NEAR A
500MB DEFORMATION ZONE/COL BASED ON 00Z ANALYSIS. ALL THE MODELS
PICK UP ON THIS FEATHER AND INCREASE 700MB RELATIVE HUMIDITY
VALUES EARLY THIS MORNING. THE HRRR EVEN SUGGESTS SOME LIGHT
PRECIPITATION WILL BE POSSIBLE. BASED ON LATEST RADAR TRENDS WILL
FOLLOW THE HRRR AND INTRODUCE SOME LIGHT PRECIPITATION EARLY THIS
MORNING IN SOUTH CENTRAL KANSAS.
AN UPPER LEVEL RIDGE WILL THEN BUILD ACROSS THE CENTRAL AND
NORTHERN ROCKIES LATER TODAY AS THE CENTER OF THIS HIGH, LOCATED
OVER COLORADO, MOVES VERY LITTLE. MODELS REMAIN IN GOOD AGREEMENT
IN MOVING A SURFACE BOUNDARY ACROSS WESTERN KANSAS DURING THE EARLY
MORNING HOURS AND BY THE EARLY AFTERNOON THIS BOUNDARY IS EXPECTED
TO EXTEND FROM HAYS TO GARDEN CITY TO NEAR ELKHART. FORECAST MODEL
SOUNDINGS NEAR THIS SURFACE TROUGH INDICATED SOME MID LEVEL
INSTABILITY AND MOISTURE IN THE 700-600MB LEVEL WILL BE PRESENT AS
AN UPPER LEVEL DISTURBANCE ROTATES AROUND THE UPPER HIGH AND
CROSSES INTO WESTERN KANSAS. GIVEN THE ESTIMATED TIMING OF THIS
UPPER LEVEL DISTURBANCE ALONG WITH WHERE THE BETTER THE LATE DAY
INSTABILITY IS EXPECTED WILL INCREASE THE PRECIPITATION CHANCES
NEAR THE SURFACE BOUNDARY LATE THIS AFTERNOON...ESPECIALLY IN
NORTH CENTRAL KANSAS. THE INVERTED V TYPE OF SOUNDINGS CONTINUE TO
SUGGEST THE PREVIOUS SHIFT HAD THE RIGHT IDEA WITH THE PRIMARY
HAZARD BEING WINDS GUSTY UP TO 45 MPH AND CLOUD TO GROUND
LIGHTNING.
CLOUD COVER THIS AFTERNOON WILL PLAY AN IMPORTANT ROLE ON
TEMPERATURES TODAY. MIXING DOWN THE NAM AND ECMWF 850MB
TEMPERATURES AT 00Z THURSDAY SUGGESTS HIGHS WILL BE MAINLY IN THE
100 TO 104 DEGREE RANGE. INCREASING AFTERNOON CLOUDS AHEAD OF THE
UPPER LEVEL DISTURBANCE HOWEVER MAY RESULT IN KEEPING TEMPERATURES
SEVERAL DEGREES COOLER THAN THIS. AT THIS TIME THERE STILL APPEARS
TO BE A DECENT AMOUNT OF AFTERNOON SUNSHINE SO WILL CONTINUE TO
TREND TOWARDS THE WARMER NAM/ECMWF SOLUTION WHICH HAPPENS TO BE
VERY SIMILAR TO THE PREVIOUS FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 337 AM CDT WED JUL 18 2012
THE GENERAL UPPER-LEVEL PATTERN THROUGH JULY 25TH WILL FEATURE
UPPER-LEVEL RIDGING OVER KANSAS AND UPPER-LEVEL SHORTWAVE TROUGHS
POSITIONED FAR TO THE NORTH AND WEST OF KANSAS ACROSS THE NORTHERN
ROCKIES AND SOUTHERN CANADA. HOT WEATHER WILL PERSIST THROUGHOUT THIS
PERIOD. 500MB HEIGHTS ARE PROGGED TO RISE THIS WEEK FROM 589 TO
596 DM AND THIS IMPLIES LOW TO MID-LEVEL WARMING GIVEN THAT SEA
LEVEL PRESSURE VALUES ARE EXPECTED TO CHANGE VERY LITTLE. SO HIGHS
SHOULD BE WELL OVER 100 FOR MOST OF SOUTHWEST KANSAS, EXCEPT
CLOSER TO 100 NEAR THE COLORADO BORDER. SOME READINGS NEAR
107-109F ARE POSSIBLE BY MONDAY AND TUESDAY.
THE SLOW MOVING FRONTAL BOUNDARY MENTIONED IN THE SHORT TERM DISCUSSION
THAT IS CURRENTLY OVER NORTHWEST KANSAS WILL STALL OUT IN THE MIDDLE
OF THE UPPER-LEVEL RIDGE AXIS SOMEWHERE OVER SOUTHWEST KANSAS ON
THURSDAY. THEREFORE, THERE IS A SMALL CHANCE FOR THUNDERSTORMS
WHEREVER THIS BOUNDARY STALLS OUT AND THIS IS HARD TO PINPOINT AT
THIS TIME. SO SMALL CHANCES FOR STORMS WERE INTRODUCED FOR MUCH OF
THE FORECAST AREA. EVEN THOUGH THE LOW-LEVEL MOISTURE IS MIXING
OUT IN THE HOT PLUME AS IT TRIES TO MOVE NORTHWARD INTO THE
PLAINS, SOME SURFACE BASED CAPE BETWEEN 400 AND 800 J/KG, ALONG
WITH MODEST LOW-LEVEL CONVERGENCE AND STRONG SURFACE HEATING MAY
BE ENOUGH TO INITIATE A FEW HIGH BASED THUNDERSTORMS. GIVEN THE
LOW CAPE VALUES, VERY LOW VERTICAL WIND SHEAR AND HIGH CLOUD
BASES, THE MAIN THREAT WITH THESE STORMS IS GUSTY WINDS AS HIGH AS
50 MPH AS WELL AS ANY CLOUD TO GROUND LIGHTNING.
AFTER THURSDAY, THERE IS LITTLE IN THE WAY OF HOPE FOR THUNDERSTORMS
THROUGH JULY 25TH GIVEN THE AFOREMENTIONED STRONG UPPER-LEVEL
RIDGING AND ABSENCE OF FRONTS. HOWEVER, THE LONGER RANGE MODELS
ARE OFTEN UNABLE TO RESOLVE SMALLER SCALE BOUNDARIES THAT COULD
SERVE TO INITIATE ISOLATED THUNDERSTORMS. BUT IT IS PROBABLY SAFE
TO SAY THAT WIDESPREAD BENEFICIAL RAINS ARE HIGHLY UNLIKELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 657 AM CDT WED JUL 18 2012
LIGHT SOUTHWESTERLY WINDS WILL BECOME LIGHT AS A WEAK FRONT STALLS OUT
ACROSS THE TAF SITES THIS AFTERNOON. ISOLATED THUNDERSTORMS MAY
DEVELOP AFTER 21Z ALONG THIS FRONT IN VICINITY OF THE TAF SITES.
VFR CONDITIONS WILL PREVAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 72 103 74 / 10 20 20 20
GCK 100 69 101 73 / 20 20 20 10
EHA 98 70 100 72 / 10 20 0 0
LBL 101 69 101 73 / 10 20 10 0
HYS 104 73 106 76 / 20 20 20 20
P28 104 73 105 77 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
630 AM CDT WED JUL 18 2012
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
&&
.DISCUSSION.../ISSUED 409 AM CDT/
SFC-925MB FRONT DOWN ALONG THE IOWA BORDER THIS MORNING...BUT H85
FRONT BISECTS THE THE MPX CWA FROM THE MADISON AREA OVER TO CHIP
FALLS/EAU CLAIRE. HAVE BEEN SEEING VERY WEAK THETA-E ADVECTION
NORTH OF THIS BOUNDARY AND THAT COMBINED WITH PWATS UP AROUND 2
INCHES AND MUCAPE AROUND 1500 J/KG HAS ALLOWED FOR SCATTERED
CONVECTION NORTH OF THIS H85 BOUNDARY FROM NE SODAK OVER TO GREEN
BAY. THIS WAA REGIME IS IN RESPONSE TO A SHORTWAVE THAT CAN
ACTUALLY BE SEEN ON A RADAR MOSAIC...WITH A NICE SPIN IN THE
REFLECTIVITY DOWN AROUND YANKTON...SD. THE RAP HAS ALSO BEEN
SHOWING A NICE PV ANOMALY ACROSS ERN SODAK THAT HAS HELPED
GENERATE MORE WIDESPREAD CONVECTION THERE. AS WE GO THROUGH THE
DAY...BOUTS OF SCT CONVECTION WILL CONTINUE TO OCCUR THROUGH THE
MORNING WITHIN THE WEAK CORRIDOR OF H85 THETA-E ADVECTION FROM
MAINLY CENTRAL MN INTO CENTRAL WI. THE 18.05 HRRR REFLECTIVITY
FORECAST PROBABLY HAS THE RIGHT IDEA FOR THIS MORNING...JUST
DISPLACED A LITTLE TOO FAR NORTH. AS THE AFTERNOON ROLLS
AROUND...THE PV ANOMALY WILL BEGIN WORKING ACROSS THE SRN HALF OF
THE MPX AREA. HAVE MAINLY 40 TO 50 POPS WORKING ACROSS THE AREA
FROM WRN MN INTO WRN WI THOUGH TONIGHT AS THIS PV FEATURE MOVES
ACROSS. MAY NEED TO BUMP UP POPS MORE AS THIS UPPER FEATURE HAS
HAD LITTLE TROUBLE FORCING CONVECTION OVERNIGHT. AS FOR SVR
POTENTIAL WITH THIS ACTIVITY...LACK OF SHEAR COMBINED WITH
FREEZING LEVELS OVER 14K FEET WILL KEEP THE SVR POTENTIAL PRETTY
MINIMAL WITH THE MAIN THREAT BEING FROM GUSTS WINDS IF WE CAN GET
ROBUST ENOUGH STORMS TO RAPIDLY COLLAPSE.
BESIDE RECEIVING SOME MUCH NEEDED RAIN...THIS WAVE WILL ALSO
PROVIDE CLOUD COVER AND COOLER TEMPS ACROSS MOST OF THE CWA FOR
TODAY. THE ONLY EXCEPTION WILL BE ACROSS SRN MN. +28C 925MB TEMPS
WILL NOT BE TOO FAR AWAY FROM THE I-90 CORRIDOR...AND IF THEY DO
NOT SEE MUCH IN THE WAY OF CLOUD COVER BY THE AFTERNOON...THEN
WILL BE ANOTHER LOWER TO MIDDLE 90S DAY DOWN THERE. DEPENDING ON
CLOUD COVER DURATION...MAY HAVE SOME AREAS STAY IN THE 70S FOR
HIGHS TODAY...ESPECIALLY IN THE NORTHEAST SECTION OF THE
CWA...WHERE TEMPS THROUGH H85 WILL BE A BIT COOLER TO BEGIN WITH.
THESE COOLER TEMPS WILL CONTINUE INTO THURSDAY...FOR WRN WI AT
LEAST...AS STRONG NW FLOW SETS IN ALOFT BEHIND TODAYS SHORTWAVE.
FOR FRIDAY THROUGH TUESDAY...THE BIG PLAYER HERE WILL BE THE
STRONG UPPER RIDGE WE HAVE SEEN ALL SUMMER WAFFLING ACROSS THE
CONUS. BY THURSDAY...ANOTHER 595+DM H5 HIGH WILL BE BUILDING
ACROSS THE HIGH PLAINS WITH THE HEAT BUBBLE WE BEAT BACK SOME
TODAY RAPIDLY REBUILDING TO THE WEST. THIS H5 RIDGE WILL SLOWLY
SHIFT INTO THE CENTRAL PLAINS FROM THE WEEKEND INTO EARLY NEXT
WEEK. UP HERE...THE MPX CWA LOOKS TO BE SITTING NEAR THE NRN
PERIPHERY OF THE RIDGE. THE WARMEST DAYS OF THIS PERIOD LOOK TO BE
FRIDAY/SATURDAY AS THE NAM/ECMWF SHOW 594DM H5 HEIGHTS BUILDING UP
INTO CENTRAL MN INTO WRN WI. THE NAM IN PARTICULAR IS RATHER
AGGRESSIVE WITH WAA INTO THE AREA THESE DAYS...WITH ITS 925-850MB
TEMPS INDICATING ANOTHER ROUND OF UPPER 90S TO 102/3 TYPE HIGHS
BEING POSSIBLE BOTH DAYS. DID BUMP HIGHS UP SOME...ESPECIALLY FOR
FRIDAY...BUT MOST MODELS SHOW A NOCTURNAL CONVECTIVE SYSTEM FIRING
OFF TO THE NORTH FRI NIGHT...THAT MAY TRY TO LAY DOWN INTO NRN
SECTIONS OF THE MPX CWA SATURDAY. GIVEN THE UNCERTAINTIES WITH
CLOUD COVER FOR SATURDAY...WAS A BIT MORE CONSERVATIVE WITH HIGHS
THEN. DUE TO PROXIMITY TO UPPER RIDGE...THE MPX AREA WILL BE PRONE
TO ANY RING OF FIRE CONVECTION SATURDAY THROUGH MONDAY. BY
TUESDAY...BOTH THE ECMWF AND GFS CONTINUE TO SHOW A STRONGER COLD
FRONT SWEEPING ACROSS THE AREA...WHICH AT THIS POINT REPRESENTS
THE BEST CHANCES FOR RAIN AFTER TODAY. THIS FRONT ALSO LOOKS TO
PROVIDE ANOTHER 2 OR 3 DAY REPRIEVE FROM THE HEAT AS WELL.
&&
.AVIATION.../12Z TAF ISSUANCE/
THE COMPLEX OF SHOWERS AND THUNDERSTORMS OVER ERN SD WILL CONTINUE TO
EXPAND INTO WEST/CENTRAL MN THIS MORNING...AS A SHORTWAVE LIFTS
INTO THE AREA AND INTERACTS WITH THE BOUNDARY OVER SOUTHERN MN.
HAVE INCLUDED ASSOCIATED PERIODS OF SHOWERS AND
THUNDERSTORMS...ALONG WITH MVFR CIGS/VSBYS. EAST WINDS AROUND OR
JUST BELOW 10 KTS WILL PREVAIL TODAY...AND THEN DECREASE BELOW 5
KTS TONIGHT. THERE COULD BE SOME LIGHT FOG DEVELOPMENT AFTER 09Z
THU AS WELL.
MSP...A FLEETING SHRA CANNOT BE RULED OUT PRIOR TO 14Z...BUT THE
MAIN WINDOW OF TIME FOR SHRA/TS IS EXPECTED TO BE BETWEEN 15Z AND
20Z. PERIODS OF MVFR CIGS/VSBYS WILL BE POSSIBLE WITH THE
ACTIVITY. WHILE ISOLD SHOWERS APPEAR POSSIBLE THIS
AFTERNOON...ACTIVITY SHOULD WANE AFTER 21Z. EAST WINDS AROUND 10
KTS WILL PREVAIL TODAY...AND DECREASE BELOW 5 KTS AFTER 06Z...WHEN
LIGHT FOG FORMATION AND MVFR VSBYS APPEAR POSSIBLE.
OUTLOOK...
WED NIGHT/EARLY THU...CHC OF BR AND ASSOCIATED MVFR CIGS BETWEEN
08Z AND 12Z. THU/FRI...VFR. SAT...VFR BUT INCREASING HIGH CLOUDS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/LS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1021 AM EDT WED JUL 18 2012
.SYNOPSIS...
A COLD FRONT LOCATED JUST SOUTH OF NEW YORK STATE WILL CONTINUE TO
TO DRIFT SLOWLY TO THE SOUTH THIS AFTERNOON. SOMEWHAT MOIST AND
UNSTABLE AIR LINGERING NORTH OF THE FRONT WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO THE SOUTHERN TIER AND UPPER GENESEE
VALLEY...WHILE AREAS TO THE NORTH SEE SOME INCREASE IN SUNSHINE.
CANADIAN HIGH PRESSURE WILL BRING A WELCOME CHANGE TO COOLER AND
LESS HUMID CONDITIONS TONIGHT THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST SURFACE MAP SHOWS THE COLD FRONT SITUATED JUST SOUTH OF
THE NEW YORK/PA BORDER. THE MOIST NORTHERLY FLOW LINGERING BEHIND
THE FRONT IS GENERATING A FAIR AMOUNT OF CLOUDS SOUTH OF LAKE
ONTARIO...BUT AS SOMEWHAT DRIER AIR ADVECTS SOUTH OF THE LAKE THIS
AFTERNOON...EXPECT TO SEE A GRADUAL NORTH TO SOUTH DECREASE IN
CLOUDS. THE EXCEPTION TO THIS GENERAL TREND WILL BE ACROSS THE
SOUTHERN TIER AND PARTS OF THE UPPER GENESEE VALLEY WHERE THE RISK
FOR CONVECTION WILL CONTINUE TODAY. THE MAIN CULPRIT IS AN AREA OF
FAVORABLE LOW LEVEL MOISTURE CONVERGENCE AND INSTABILITY CENTERED
ALONG AN ELEVATED FRONT THAT STRETCHES FROM CENTRAL MICHIGAN TO LAKE
ERIE. THE LATEST GUIDANCE SUGGESTS THAT THE EASTERN END OF THIS
ELEVATED INSTABILITY AXIS WILL WORKS INTO THE SOUTHERN TIER LATER
THIS MORNING AND REMAIN IN PLACE THROUGH A GOOD PART OF THE
AFTERNOON. BASED ON THE LATEST RADAR TRENDS...THE CONVECTION THAT IS
CURRENTLY OVER EASTERN LAKE ERIE WILL BE ADVECTING ACROSS
CHAUTAUQUA COUNTY BY LATE MORNING. AFTER THAT...EXPECT SCATTERED
SHOWERS/THUNDERSTORMS TO SPREAD MORE TO THE EAST AND POSSIBLY IMPACT
PARTS OF THE UPPER GENESEE VALLEY...A TREND THE LATEST HRRR PICKS UP
ON. IN TERMS OF THE STRENGTH OF THE CONVECTION...IT STILL LOOKS
LIKE THE MOST UNSTABLE AIR WILL REMAIN SOUTH OF THE NEW YORK BORDER
EVEN THOUGH THE MORE FAVORABLE EFFECTIVE SHEAR WILL BE IN PLACE OVER
OUR CWA. BASED ON THESE TRENDS...WILL KEEP THE HIGHEST CHANCE POPS
FOR MEASURABLE PCPN OVER THE SOUTHERN TIER.
TEMPERATURES TODAY WILL BE A BIT COOLER THAN THE HOT AND HUMID
CONDITIONS OBSERVED ON TUESDAY...ALTHOUGH HUMIDITY LEVELS WILL STILL
BE IN THE UNCOMFORTABLE RANGE.
TONIGHT...CANADIAN HIGH PRESSURE CENTERED OVER THE HUDSON BAY WILL
BUILD IN BEHIND THE FRONT. EXPECTING CLEAR SKIES ACROSS MUCH OF THE
FORECAST AREA EXCEPT FOR MAYBE LINGERING CLOUDINESS ACROSS THE
SOUTHERN TIER FROM AFTERNOON STORMS. MUCH MORE COMFORTABLE SLEEPING
TEMPERATURES WILL OCCUR OVERNIGHT ALLOWING FOR THOSE AIR
CONDITIONERS TO TAKE A BREAK. TEMPS FALLING INTO THE LOW TO MID 60S
FOR WESTERN NY TO UPPER 50S ACROSS THE NORTH COUNTRY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
CANADIAN HIGH PRESSURE CENTERED NEAR JAMES BAY WILL NOSE DOWN
ACROSS WESTERN AND CENTRAL NEW YORK THURSDAY...THEN GRADUALLY
SHIFT TO THE SOUTHEAST AS THE TROUGH OVER QUEBEC MOVES INTO THE
NEW ENGLAND STATES. PLENTY OF DRY AIR SUGGESTED ACROSS NORTHERN
SECTIONS FOR SUNNY/MOSTLY SUNNY FORECAST...WHILE A BIT MORE
MOISTURE ACROSS THE SOUTHERN HALF OF THE AREA IN CLOSER PROXIMITY
TO FRONTAL BOUNDARY LINGERING TO THE SOUTH AND WEST OF THE AREA.
NOTICEABLY COOLER DAY WITH HIGHS GENERALLY IN THE MID TO UPPER
70S.
00Z MODELS SIGNALS ARE SIMILAR WITH IMPLIED MESOSCALE
DETAILS/EVOLUTION UNCERTAIN...WITH RESPECT TO THE PLACEMENT OF
UPSTREAM CONVECTION ALONG WHAT SHOULD BE AN ACTIVE SURFACE
FRONTAL ZONE JUST OFF TO OUR SOUTH AND WEST THROUGH THE REST OF
THE SHORT TERM PERIOD. SOME MODEL SUGGESTION THAT CONVECTIVE
COMPLEXES WILL RIDE ALONG THE FRONTAL ZONE FROM THE SOUTHERN
GREAT LAKES THROUGH THE OHIO VALLEY...WITH THE NORTHERN EXTENT OF
THIS CONVECTION POTENTIALLY SHIFTING NORTHWARD INTO SOUTHERN
PORTIONS OF THE AREA. AT THIS TIME...PREFER TO GIVE MORE WEIGHT
TO A PERSISTENCE DRY FORECAST WITH THE CANADIAN HIGH SHIFTING
CONVECTIVE CHANCES OFF TO OUR SOUTH. SEASONABLE TEMPERATURES
REMAINING FRIDAY WITH MOST HIGHS IN THE UPPER 70S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THIS TIME PERIOD WILL LARGELY BE DRY...THOUGH A WEAK FRONTAL
BOUNDARY COULD BRING SOME SPOTTY SHOWERS AND THUNDERSTORMS TOWARDS
THE END OF THE WEEKEND/BEGINNING OF THE WORK WEEK. TEMPERATURES WILL
AVERAGE AROUND NORMAL FOR THE TIME PERIOD AND NO EXTREME HEAT
EXPECTED.
THE LARGE SCALE PATTERN FOR THIS TIME PERIOD PLACES A BROAD RIDGE OF
HIGH PRESSURE OVER THE CENTRAL US/ROCKIES WITH SHORT WAVE TROUGHS
ROUNDING THE RIDGE AND CROSSING THE EASTERN GREAT LAKES THROUGH THE
PERIOD.
FOR FRIDAY A GENERAL TROUGH WILL BE ACROSS NEW ENGLAND AND THE
EASTERN GREAT LAKES REGION. MOISTURE IS MARGINAL AND WITH PLENTY OF
DRY AIR IN THE LOW TO MID LEVELS BELOW THIS MOISTURE WILL MAINTAIN
THE DRY FORECAST WITH A MIX OF SUN AND CLOUDS. WITH THIS NORTHERLY
FLOW EXPECT AFTERNOON TEMPERATURES TO REMAIN BELOW NORMAL...WITH
COMFORTABLE SUMMER HIGHS IN THE MID TO UPPER 70S.
ON SATURDAY BOTH THE 12Z ECMWF AND GFS BRING A RIDGE ALOFT ACROSS
THE REGION BEHIND A SHORT WAVE THAT IS EXITING ACROSS NEW ENGLAND
AND OVER THE WESTERN ATLANTIC. WITH AMPLE DRY AIR EXPECT MOSTLY
SUNNY SKIES AND AFTERNOON TEMPERATURES SEVERAL DEGREES WARMER. AIR
TEMPERATURES OF LOW TO MID 80S WILL BE COMMON...AND THOUGH DEW
POINTS WILL BE RISING MOST AREAS SHOULD STAY BELOW 60...SO WE SHOULD
STILL REMAIN COMFORTABLE.
ON SUNDAY BOTH THE ECMWF AND GFS BRING THE CREST OF WARMTH ALOFT
ACROSS THE REGION WITH 850 HPA TEMPERATURES REACHING +15 TO +18C.
BEHIND THE UPPER LEVEL RIDGE CLOUDS WILL LIKELY INCREASE SOME AS
WELL...LEAVING TEMPERATURES SUNDAY SIMILAR TO SATURDAY. AN UPPER
LEVEL SHORT WAVE ACROSS SOUTHERN CANADA WILL CLIP/NEAR THE NORTH
COUNTRY SUNDAY WITH A SLIGHT CHANCE FOR A SHOWER OR ISOLATED
THUNDERSTORMS. THOUGH TEMPERATURES SUNDAY WILL BE SIMILAR TO
SATURDAY THE DEW POINT WILL BE HIGHER...WITH A MORE NOTICEABLE FEEL
OF HUMIDITY TO THE AIR. DEW POINTS WILL LIKELY CLIMB INTO THE 60S ON
SUNDAY.
ON MONDAY BOTH THE ECMWF AND GFS BRING A WEAK FRONTAL BOUNDARY
ACROSS THE REGION FROM THE NORTHERN GREAT LAKES. WITH THE BUILDING
MOISTURE AHEAD OF THIS FRONT A SHOWER OR THUNDERSTORM IS POSSIBLE
LATE SUNDAY NIGHT AND INTO MONDAY. GIVEN OUR DRY SPELL AND THE
WEAKNESS OF THIS FRONTAL BOUNDARY WILL JUST GO WITH LOW CHC POPS.
SOUTHWESTERLY WINDS AHEAD OF THIS FRONTAL BOUNDARY WILL MAINTAIN
SLIGHTLY WARMER THAN NORMAL TEMPERATURES FOR OUR REGION WITH
AFTERNOON HIGHS IN THE 80S
TUESDAY BOTH THE GFS AND ECMWF BRING DRIER AIR ACROSS THE REGION
WITH HIGH PRESSURE FOLLOWING THE WEAK FRONTAL BOUNDARY. SLIGHTLY
COOLER...BUT MORE NOTICEABLE LOWER DEWPOINTS ON TUESDAY WITH A
RETURN TO PLENTY OF SUNSHINE.
OVERNIGHT LOWS WILL GENERALLY FALL BACK INTO THE 60S...WITH THE
WARMEST NIGHT LIKELY SUNDAY NIGHT AHEAD OF THE WEAK COLD FRONT...AND
COOLEST MORNINGS FRIDAY AND SATURDAY WITH MAINLY CLEAR SKIES...LOW
DEW POINTS AND LIGHT WINDS.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR CONDITIONS...WITH KROC SEEING MVFR CIGS THIS
MORNING IN LOWER CLOUDS NORTH OF A COLD FRONT. ISOLATED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ACROSS WESTERN NY NEAR THE FRONT WITH
MORE SCATTERED ACTIVITY DEVELOPING ACROSS THE SOUTHERN TIER LATER
THIS AFTERNOON. ALL SITES WILL SEE CLEARING SKIES GOING INTO TONIGHT
AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT. LAMP AND GFS MOS
GUIDANCE INDICATE POSSIBLE LOW VIS TONIGHT IN FOG AFTER 08Z.
INCLUDED 4SM FOR NOW IN THE TAF UNTIL CONFIDENCE INCREASES. IF KJHW
DOES PICK UP SOME RAIN FROM STORMS TODAY THEN FOG MORE LIKELY
TONIGHT.
OUTLOOK...
THURSDAY THROUGH SUNDAY...MAINLY VFR.
&&
.MARINE...
A COLD FRONT IS SOUTH OF LAKE ONTARIO ACROSS WESTERN NY TODAY WITH
SCATTERED TO SHOWERS AND THUNDERSTORMS OCCUR ACROSS LAKE ERIE THIS
AFTERNOON. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD IN ACROSS NEW
YORK INTO THE WEEKEND AND CALM CONDITIONS WILL PREVAIL ACROSS BOTH
LAKES. NO SCA CONDITIONS EXPECTED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH/TJP
NEAR TERM...SMITH/TJP
SHORT TERM...TMA
LONG TERM...THOMAS
AVIATION...SMITH
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
736 AM EDT WED JUL 18 2012
.SYNOPSIS...
A COLD FRONT OVER LOWER MICHIGAN WILL MOVE SOUTHEAST ACROSS THE AREA
LATER TODAY AND THEN BECOME STATIONARY ACROSS CENTRAL OHIO
TONIGHT AND THURSDAY. THE FRONT WILL REACH THE OHIO RIVER LATE THURSDAY
NIGHT. HIGH PRESSURE OVER CENTRAL CANADA WILL SLOWLY BUILD TOWARD
THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT WILL BE MOVING IN FROM THE NORTH TODAY. A WEAK SHORT
WAVE IS MOVING THROUGH THE NORTHEAST COUNTIES AND IT IS CAUSING
SOME ISOLATED SHOWERS AND THUNDERSTORMS. THE MAIN THREAT SHOULD BE
LATE THIS MORNING AND IN THE AFTERNOON. THE AIRMASS IS UNSTABLE
AND IT DOES LOOK LIKE WE WILL GET SOME HEATING IN THE MORNING. THE
CONVECTIVE TEMPERATURES ARE NEAR 90...SO THE CUMULUS WILL DEVELOP
QUICKLY AND I THINK THE THUNDERSTORMS WILL ALSO DEVELOP FAST. SOME
THUNDERSTORMS COULD EVEN MOVE IN FROM MICHIGAN...HOWEVER...I THINK
MOST OF THEM WILL DEVELOP OVER THE FORECAST AREA. THE AIRMASS IS
UNSTABLE ENOUGH AND WITH THE FRONT APPROACHING SOME OF THE
THUNDERSTORMS COULD BE SEVERE. THE THUNDERSTORMS COULD BEGIN
DEVELOPING AS EARLY AS 10 AM AND SEVERE THUNDERSTORMS WILL BE
LIKELY ESPECIALLY THIS AFTERNOON. THE HRRR MODEL IS A LITTLE
SLOW IN DEVELOPING THE THUNDERSTORMS. THE MAIN THREAT OF ANY
SEVERE WX WILL BE WIND AND HAIL. FAIRLY CONFIDENT THAT A SEVERE
THUNDERSTORM WATCH WILL BE ISSUED TODAY FOR A LARGE PART OF THE
FORECAST AREA.
WENT A LITTLE COOLER ON SOME OF THE HIGHS IN THE NORTH BECAUSE OF
THE EXPECTED CLOUD COVER AND QUICK THUNDERSTORM DEVELOPMENT. AREAS
FROM FINDLAY THROUGH UPPER SANDUSKY TO MARION TO MOUNT VERNON WILL
BE CLOSE TO HEAT ADVISORY CRITERIA...MAINLY UP TO 99. BECAUSE OF
THAT WILL NOT ISSUE A HEAT ADVISORY. IF THE CLOUDS DO NOT DEVELOP
AS EXPECTED A HEAT ADVISORY MAY HAVE TO BE ISSUED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
EXPECTING THE THREAT OF THUNDERSTORMS TO DECREASE QUICKLY FROM THE
NORTH THIS EVENING. THURSDAY IS A TOUGH FORECAST. THE NAM KEEPS THE FRONT
VERY CLOSE TO THE REGION AND IF THAT IS CORRECT THAT WOULD MEAN A
LOT OF SHOWERS AND THUNDERSTORMS ACROSS THE WHOLE FORECAST AREA.
GOING MORE WITH THE GFS AND ECMWF AND WILL KEEP THE HIGHS POPS
ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. AS THE FRONT SAGS
SOUTH THURSDAY NIGHT THE THREAT OF THUNDERSTORMS WILL DECREASE
FROM NORTH TO SOUTH. FRIDAY INTO SATURDAY NIGHT WILL BE DRY AS
HIGH PRESSURE BUILDS IN FROM CANADA. USED A BLEND OF GUIDANCE FOR
THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
HIGH PRESSURE OVER THE OHIO VALLEY WILL KEEP SUNDAY QUIET. A FRONTAL
BOUNDARY WILL BE LURKING ACROSS THE CENTRAL LAKES...BUT TIMING THIS
INTO OUR AREA IS STILL DIFFICULT. WILL STICK WITH THE PREVIOUS
FORECAST AND HAVE CHANCE POPS FOR MONDAY. TEMPERATURES WILL BE
WARMING INTO THE UPPER 80S/NEAR 90 FOR SUN-MON. IF FRONT COMES
THROUGH OR IS NEARBY STILL WITH CLOUD COVER...EXPECTING SLIGHTLY
COOLER TUE. HIGH PRESSURE WILL BE NORTH OF THE AREA.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SLOWING AND WEAKENING COLD FRONT TO SAG SOUTH ACROSS THE AREA
TODAY. LATEST ANALYSIS PLACES IT ACROSS NORTHERN OHIO...BUT THERE
IS SOME CONVECTION BEHIND IT. CONVECTION SHOULD QUICKLY POP UP
LATER THIS MORNING SOUTH OF THE FRONT INTO THE EARLY AFTERNOON
WITH AMPLE INSTABILITY. HAVE CONTINUED THE VCTS MENTION AT THIS
POINT...BUT ALSO ADDED A TEMPO FOR THOSE SITES MOST LIKELY TO GET
TS TODAY. THERE MAY BE A ROGUE SHRA/TS BEFORE THIS...BUT TOO
ISOLATED TO MENTION. SOME SEVERE POTENTIAL WITH STRONG GUSTY
WINDS. HAVE WRAPPED UP CONVECTION BY LATE AFTERNOON NORTH TO MID
EVENING SOUTH. IT REALLY APPEARS THAT CONVECTION WILL BUBBLE UP
EARLY...BE SCATTERED TO NUMEROUS...AND THEN BE OVER. FRONT MAY BE
DIFFUSE AT THIS POINT AND THERE WILL BE LITTLE ALOFT TO SUPPORT
MUCH. WINDS WILL BE RELATIVELY LIGHT TODAY AND WIND SHIFT HARD TO
TIME. THE REST OF WEDNESDAY NIGHT SHOULD BE QUIET. THOSE PLACES
THAT DO GET PRECIP RUN THE POTENTIAL FOR FOG WEDNESDAY
NIGHT/THURSDAY MORNING. WINDS WILL BE LIGHT/VARIABLE AT THIS POINT
AND LOW LEVEL MOISTURE WILL STILL BE PRESENT...BUT WE MAY HAVE A
FAIR AMOUNT OF MID/HIGH CLOUDS TO INHIBIT FOG. FOR NOW HAVE 3-6SM BR.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WITH BR/FG LATE TONIGHT INTO
EARLY THURSDAY. A CHANCE OF NON-VFR THURSDAY...MAINLY WEST AND
SOUTH OF KMFD IN SHRA/TS.
&&
.MARINE...
COLD FRONT SINKING SOUTH ACROSS THE LAKE THIS MORNING. SOME
SHOWERS/TS ASSOCIATED WITH IT...BUT MOST OF THE ACTIVITY WILL BE
INLAND. WINDS WILL BE LIGHT FROM THE NORTH AFTER THE FRONT. HIGH
PRESSURE BUILDS ACROSS ONTARIO FOR THU-FRI...SHIFTING EAST SAT/SUN.
THIS WILL PRODUCE A PERIOD OF NORTHEAST FLOW. THIS PERSISTENT FLOW
DOWN THE LENGTH OF THE LAKE WILL LIKELY MAKE THE ISLANDS A LITTLE
CHOPPY. WILL GO WITH AN AVERAGE OF 4 FOOTERS...A SMALL CRAFT ADV MAY
BE NEEDED THU/FRI. COULD DEFINITELY SEE 15 KNOTS...POSSIBLY UPWARDS
OF 20 KNOTS. BY SATURDAY WINDS RELAX AND BY SUNDAY SHIFT TO COME OUT
OF THE SOUTH.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
639 AM EDT WED JUL 18 2012
.SYNOPSIS...
A COLD FRONT OVER LOWER MICHIGAN WILL MOVE SOUTHEAST ACROSS THE AREA
LATER TODAY AND THEN BECOME STATIONARY ACROSS CENTRAL OHIO
TONIGHT AND THURSDAY. THE FRONT WILL REACH THE OHIO RIVER LATE THURSDAY
NIGHT. HIGH PRESSURE OVER CENTRAL CANADA WILL SLOWLY BUILD TOWARD
THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT WILL BE MOVING IN FROM THE NORTH TODAY. A WEAK SHORT
WAVE IS MOVING THROUGH THE NORTHEAST COUNTIES AND IT IS CAUSING
SOME ISOLATED SHOWERS AND THUNDERSTORMS. THE MAIN THREAT SHOULD BE
LATE THIS MORNING AND IN THE AFTERNOON. THE AIRMASS IS UNSTABLE
AND IT DOES LOOK LIKE WE WILL GET SOME HEATING IN THE MORNING. THE
CONVECTIVE TEMPERATURES ARE NEAR 90...SO THE CUMULUS WILL DEVELOP
QUICKLY AND I THINK THE THUNDERSTORMS WILL ALSO DEVELOP FAST. SOME
THUNDERSTORMS COULD EVEN MOVE IN FROM MICHIGAN...HOWEVER...I THINK
MOST OF THEM WILL DEVELOP OVER THE FORECAST AREA. THE AIRMASS IS
UNSTABLE ENOUGH AND WITH THE FRONT APPROACHING SOME OF THE
THUNDERSTORMS COULD BE SEVERE. THE THUNDERSTORMS COULD BEGIN
DEVELOPING AS EARLY AS 10 AM AND SEVERE THUNDERSTORMS WILL BE
LIKELY ESPECIALLY THIS AFTERNOON. THE HRRR MODEL IS A LITTLE
SLOW IN DEVELOPING THE THUNDERSTORMS. THE MAIN THREAT OF ANY
SEVERE WX WILL BE WIND AND HAIL. FAIRLY CONFIDENT THAT A SEVERE
THUNDERSTORM WATCH WILL BE ISSUED TODAY FOR A LARGE PART OF THE
FORECAST AREA.
WENT A LITTLE COOLER ON SOME OF THE HIGHS IN THE NORTH BECAUSE OF
THE EXPECTED CLOUD COVER AND QUICK THUNDERSTORM DEVELOPMENT. AREAS
FROM FINDLAY THROUGH UPPER SANDUSKY TO MARION TO MOUNT VERNON WILL
BE CLOSE TO HEAT ADVISORY CRITERIA...MAINLY UP TO 99. BECAUSE OF
THAT WILL NOT ISSUE A HEAT ADVISORY. IF THE CLOUDS DO NOT DEVELOP
AS EXPECTED A HEAT ADVISORY MAY HAVE TO BE ISSUED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
EXPECTING THE THREAT OF THUNDERSTORMS TO DECREASE QUICKLY FROM THE
NORTH THIS EVENING. THURSDAY IS A TOUGH FORECAST. THE NAM KEEPS THE FRONT
VERY CLOSE TO THE REGION AND IF THAT IS CORRECT THAT WOULD MEAN A
LOT OF SHOWERS AND THUNDERSTORMS ACROSS THE WHOLE FORECAST AREA.
GOING MORE WITH THE GFS AND ECMWF AND WILL KEEP THE HIGHS POPS
ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. AS THE FRONT SAGS
SOUTH THURSDAY NIGHT THE THREAT OF THUNDERSTORMS WILL DECREASE
FROM NORTH TO SOUTH. FRIDAY INTO SATURDAY NIGHT WILL BE DRY AS
HIGH PRESSURE BUILDS IN FROM CANADA. USED A BLEND OF GUIDANCE FOR
THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
HIGH PRESSURE OVER THE OHIO VALLEY WILL KEEP SUNDAY QUIET. A FRONTAL
BOUNDARY WILL BE LURKING ACROSS THE CENTRAL LAKES...BUT TIMING THIS
INTO OUR AREA IS STILL DIFFICULT. WILL STICK WITH THE PREVIOUS
FORECAST AND HAVE CHANCE POPS FOR MONDAY. TEMPERATURES WILL BE
WARMING INTO THE UPPER 80S/NEAR 90 FOR SUN-MON. IF FRONT COMES
THROUGH OR IS NEARBY STILL WITH CLOUD COVER...EXPECTING SLIGHTLY
COOLER TUE. HIGH PRESSURE WILL BE NORTH OF THE AREA.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SLOWING AND WEAKENING COLD FRONT TO SAG SOUTH ACROSS THE AREA
TODAY. CONVECTION SHOULD QUICKLY POP UP LATER THIS MORNING INTO
THE EARLY AFTERNOON WITH AMPLE INSTABILITY. HAVE CONTINUED THE
VCTS MENTION AT THIS POINT...BUT HAVE MOVED UP THE TIME. THERE MAY
BE A ROGUE SHRA/TS BEFORE THIS...BUT TOO ISOLATED TO MENTION. SOME
SEVERE POTENTIAL WITH STRONG GUSTY WINDS. HAVE WRAPPED UP
CONVECTION BY LATE AFTERNOON NORTH TO MID EVENING SOUTH. IT REALLY
APPEARS THAT CONVECTION WILL BUBBLE UP EARLY...BE SCATTERED TO
NUMEROUS...AND THEN BE OVER. FRONT MAY BE DIFFUSE AT THIS POINT
AND THERE WILL BE LITTLE ALOFT TO SUPPORT MUCH. WINDS WILL BE
RELATIVELY LIGHT TODAY AND WIND SHIFT HARD TO TIME. THE REST OF
WEDNESDAY NIGHT SHOULD BE QUIET. THOSE PLACES THAT DO GET PRECIP
RUN THE POTENTIAL FOR FOG WEDNESDAY NIGHT/THURSDAY MORNING. WINDS
WILL BE LIGHT/VARIABLE AT THIS POINT AND LOW LEVEL MOISTURE WILL
STILL BE PRESENT. FOR NOW HAVE 6SM BR.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE WITH BR/FG LATE TONIGHT INTO
EARLY THURSDAY. A CHANCE OF NON-VFR THURSDAY...MAINLY WEST AND
SOUTH OF KMFD IN SHRA/TS.
&&
.MARINE...
COLD FRONT SINKING SOUTH ACROSS THE LAKE THIS MORNING. SOME
SHOWERS/TS ASSOCIATED WITH IT...BUT MOST OF THE ACTIVITY WILL BE
INLAND. WINDS WILL BE LIGHT FROM THE NORTH AFTER THE FRONT. HIGH
PRESSURE BUILDS ACROSS ONTARIO FOR THU-FRI...SHIFTING EAST SAT/SUN.
THIS WILL PRODUCE A PERIOD OF NORTHEAST FLOW. THIS PERSISTENT FLOW
DOWN THE LENGTH OF THE LAKE WILL LIKELY MAKE THE ISLANDS A LITTLE
CHOPPY. WILL GO WITH AN AVERAGE OF 4 FOOTERS...A SMALL CRAFT ADV MAY
BE NEEDED THU/FRI. COULD DEFINITELY SEE 15 KNOTS...POSSIBLY UPWARDS
OF 20 KNOTS. BY SATURDAY WINDS RELAX AND BY SUNDAY SHIFT TO COME OUT
OF THE SOUTH.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1116 AM EDT WED JUL 18 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTHWARD THROUGH CENTRAL PENNSYLVANIA
THIS AFTERNOON AND EVENING. THERE IS A THREAT FOR SEVERE
THUNDERSTORMS UNTIL THE FRONT CAN GET TO THE MASON DIXON LINE THIS
EVENING. THE FRONT WILL THEN BECOME NEARLY STATIONARY ALONG THE
BORDER AND MAINTAIN UNSETTLED WEATHER ACROSS THE SOUTHERN HALF OF
THE KEYSTONE STATE THURSDAY AND FRIDAY. IMPROVING CONDITIONS
SHOULD ARRIVE BY THE WEEKEND AS HIGH PRESSURE PUSHES THE FRONTAL
ZONE SOUTHWARD.
&&
.NEAR TERM /THROUGH TONIGHT/...
TEMPS TO 90F ALREADY IN THE LOWER SUSQ...AND M80S EVERYWHERE ELSE.
CAPES CLIMBING AS THE HEAT BUILDS WITH 70+ DEWPOINTS. CLUSTER OF
WEAK TSTORMS MOVING INTO THE CENTRAL MTS ATTM LOOK LIKE THEY WILL
CONTINUE WITH LITTLE CHANGE IN ATMOS IN ADVANCE OF THE STORMS.
ADDITIONAL CU POPPING SIGNALING LLVL INSTABILITY. WIND SHIFT
ALREADY AT BFD AND FKL AND ONLY WEAK CONVERGENCE THERE. THE BEST
CONVERGENCE IS INTO THAT CLUSTER OF CELLS. RUC FINALLY HAS A
HANDLE ON CURRENT CONVECTION AND CONTINUES TO FLARE UP MOST STORMS
ALONG THE FRONT AS IT DROPS SWRD THROUGH THE CENTRAL MTS AND INTO
THE SRN TIER LATER THIS AFTN AND EVENING.
THE ENTIRE CWA REMAINS IN THE SPC D1 CATEGORICAL SLIGHT RISK WITH
THE PRIMARY SVR TSTM HAZARDS BEING DAMAGING WINDS AND LARGE HAIL.
STRONGER MID-UPPER LVL WINDS WILL REMAIN NORTH OF THE LEADING
FRONTAL BOUNDARY. HOWEVER 25-35KTS OF EFFECTIVE SHEAR AND DEEP
LAYER WLY FLOW WILL FAVOR BOTH MULTI AND SUPER CELLULAR STRUCTURES
WITH SOME LINEAR/BOWING LINE SEGMENTS. WEAK 0-1KM SHEAR AND HIGH
LCL/S SUGGEST THAT THE ENVIRONMENT IS LIKELY NOT CONDUCIVE FOR
TORNADOES.
SHOWER/TSTM ACTIVITY ACROSS THE SOUTH SHOULD LINGER INTO THE 03Z
TIMEFRAME BEFORE WEAKENING AND GRADUALLY DISSIPATING INTO TONIGHT.
LLVL THETA-E AND PWAT GRADIENT SUGGESTS THAT THE E-W FRONTAL ZONE
WILL STALL JUST SOUTH OF I-80...WITH THE BEST CHC FOR ADDNL PCPN
OVER THE SRN 1/2 OF THE CWA OVERNIGHT.
HIGHS TODAY WILL AVG +10 DEGREES ABOVE MID JULY CLIMATE
NORMALS...RANGING FROM THE MID-UPPER 80S IN THE NRN/WRN MTNS TO
LOW-MID 90S ACRS THE CENTRAL-SRN VALLEYS. A HEAT ADVY REMAINS IN
EFFECT FOR THE LWR SUSQ VLY...WHERE HEAT INDEX VALUES WILL PEAK IN
THE LOW 100S DURING THE MID-LATE AFTN.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
MDL DATA INDICATES QUASI-STATIONARY EAST/WEST FRONT WILL BISECT
THE STATE ON THURSDAY. DIURNAL HEATING OF MOIST AIR MASS SOUTH OF
FRONT SHOULD RESULT NUMEROUS TSRA SOUTH OF I-80 BY AFTN. SVR
THREAT NOT PARTICULARLY HIGH...GIVEN WEAK SHEAR. HOWEVER...MODERATE
CAPES SUGGEST A FEW STRONG PULSE-TYPE STORMS ARE POSSIBLE OVER THE
SOUTH. NR HAVE PAINTED A SHARP DECREASE IN POPS IN DRIER AIR MASS
ACROSS NORTHERN PA. DESPITE MCLDY SKIES ACROSS THE SOUTHERN HALF
OF THE STATE...TEMPS STILL LIKELY TO BE A BIT ABV SEASONAL NORMS
ON THURSDAY. ENS MEAN 850MB TEMPS SUPPORT HIGHS FROM THE L80S OVR
THE ALLEGHENY PLATEAU...TO THE U80S IN THE SUSQ VALLEY.
LATEST MDL GUIDANCE A BIT STRONGER WITH SHORTWAVE TROF DROPPING
INTO THE OHIO VALLEY LATE THIS WEEK. THE RESULTING SFC WAVE WILL
LIKELY SPREAD AN OVERRUNNING RAINFALL INTO SOUTHERN PA LATE THU
NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
POTENTIAL EXISTS FOR A SUBSTANTIAL RAINFALL ACROSS SOUTHERN PA
FRIDAY...AS SLOW MOVING WAVE OF LOW PRESSURE PASSES SOUTH OF THE
MASON DIXON LINE. 00Z GEFS INDICATING AN ANOMALOUS EASTERLY LL JET
AND PWATS FOCUSED ALONG THE S TIER COUNTIES...A SIGNAL FOR
SIGNIFICANT PRECIP. CURRENT GEFS MEAN QPF BTWN FRI AND FRI NITE IS
ARND AN INCH OVR THE S TIER. ALTHOUGH LIGHTER AMTS ARE EXPECTED
FURTHER NORTH...BULK OF MDL DATA SUGGESTS SOME RAIN IS LIKELY FOR
ALL BUT THE N TIER. HAVE RAISED POPS ACCORDINGLY. CLOUD COVER AND
RAIN SHOULD RESULT IN A COOL FRIDAY WITH TEMPS ACROSS THE CENTRAL
MTNS LIKELY ONLY REACHING THE L70S.
CONFIDENCE OF A DRY WEEKEND STILL HIGH...AS ALL MED RANGE
GUIDANCE PUSHES TROF AND ASSOC SFC LOW EAST OF THE AREA. CAN/T
RULE OUT AN ISOLD PM TSRA ACROSS THE S TIER SATURDAY IN VICINITY
OF STALLED FRONTAL BNDRY NR THE MASON DIXON. TEMPS SHOULD START
THE WEEKEND NR NORMAL...THEN A WARMING TREND EXPECTED SUNDAY...AS
SFC HIGH PASSES EAST OF PA AND RETURN SW FLOW OVERSPREADS THE
REGION.
A DRY NW FLOW PATTERN APPEARS LIKELY EARLY NEXT WEEK WITH TEMPS A
BIT ABV SEASONAL NORMS BASED ON ENS MEAN 850 TEMPS. A COUPLE OF
SHORTWAVES DIVING SE ACROSS THE REGION COULD BRING A SHRA/TSRA TO
PARTS OF THE AREA MON/TUE. HOWEVER...GEFS PWATS NOT IMPRESSIVE...SO
SIG RAINFALL SEEMS UNLIKELY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
COLD FRONT PUSHING SOUTH SEEMS TO BE PAST KBFD AT THIS TIME...BUT
SHOWERS TO THE NW WILL KEEP MENTION OF SHRA THERE FOR EARLY THIS
AFTN. MOISTURE HIGH SO REDUCTIONS TO IFR POSSIBLE IF THE HEAVIEST
DOWNPOURS MOVE RIGHT OVER ANY OF THE LOCAL TERMINALS.
HOWEVER...THE RISK FOR IFR IS SO LOW/VAGUE THAT I WON/T DROP ANY
SPECIFIC TERMINAL TO IFR EVEN TEMPO FOR THE TIME BEING.
THE FRONT WILL TRIGGER NMRS TSTMS INTO THE EVE HOURS. SOME STORMS
MAY BE STG-SVR WITH LOCALIZED CONVECTIVE WIND/HAIL THREATS. THE
FRONTAL BOUNDARY WILL BECOME NEARLY STATIONARY NEAR THE PA/MD
BORDER THUR- FRI...KEEPING UNSETTLED CONDS ACRS S-CENTRAL PA. A
MOIST EAST/SOUTHEAST UPSLOPE FLOW WILL DEVELOP AS HIGH PRES BUILDS
ACRS SE CANADA...AND LKLY BRING LOWER CIGS OCNL SHRA/TSRA TO SRN
AIRFIELDS THRU THE END OF THE WEEK. HIGH PRES SHOULD FINALLY TAKE
CONTROL OF THE REGIONAL WEATHER PATTERN AND BRING WDSPRD VFR OVER
THE WEEKEND.
OUTLOOK...
FRI...MVFR WITH OCNL -RA CENTRAL/SOUTH.
SAT-SUN...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR PAZ036-056-057-
059-063>066.
&&
$$
SYNOPSIS...DANGELO/STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DANGELO/STEINBUGL
AREA FORECAST DISCUSSION
NWS NEW YORK NY
251 PM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED GRIDS TO INCREASE MAX TEMPS. HEAT ADVISORY HAS BEEN
EXPANDED TO ALL BUT SOUTHERN MIDDLESEX/NEW LONDON COUNTIES PER
OBS. ADDED ENHANCED SEVERE TSTM WORDING TO THE FORECAST AS SPC HAS
ISSUED SEVERE TSTM WATCH TIL 9PM. MAX TEMPS HAVE LIKELY BEEN
REACHED IN MOST PLACES AS TSTMS ARE DEVELOPING RAPIDLY. SOME
RECORD HIGHS NEARED OR EXCEEDED...SEE CLIMATE SECTION BELOW.
OTHERWISE...A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO
THE REGION THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF
A VERY HOT AIR MASS...DAY STARTS OUT VERY WARM AND LARGE CAPE IN
THE 2000 TO 4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL
WARMING. SHEAR OF 30 KT 0-6KM WITH WET BULB ZERO HEIGHTS OF 13-14
KFT. MENTIONED GUSTY WINDS AND SMALL HAIL WITH SOME CELLS HAVING A
SLIGHT CHANCE OF GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES
WIDESPREAD...AT LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE
ENOUGH SUN TO HAVE HIGHS WELL INTO THE 90S AND WITH VERY MOIST
AIR MASS CONVEYED BY PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER
70S...HEAT INDICES ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW
YORK CITY AS WELL AS URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST
OF NE NJ AND WESTERN LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IS ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. FURTHER
DEVELOPMENT OF CONVECTION COULD ALSO OCCUR FROM CONVERGENCE ALONG
THE SEA BREEZE BOUNDARY ESPECIALLY WITH ANY OUTFLOW BOUNDARIES FROM
CONVECTION MOVING IN FROM THE NORTH AND WEST. WIND SHEAR OF 25 TO 30
KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE HAIL AND
GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO CAN BE EXPECTED
WITH THUNDERSTORMS THAT FORM. THIS IS CONSIDERED ESPECIALLY SINCE
THE FLOW WILL BE NEARLY PARALLEL FROM LOW TO MID LEVELS WHICH WOULD
ALLOW FOR TRAINING OF CELLS. THE CONVECTIVE MODE LOOKS TO BE SQUALL
LINE TO BOW ECHOES.
THERE IS A MODERATE RISK FOR RIP CURRENTS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...RELATIVELY BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE AS PWATS REMAIN NEAR 2 INCHES.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME LINGERING SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT.
POPS ARE AT SLIGHT CHANCE WITH MODEL UNCERTAINTY DUE TO DIFFERENCES
IN QPF FIELDS AND RUN TO RUN INCONSISTENCY. IN THE UPPER LEVELS AT
500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE TROUGH SETTING
UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER GUIDANCE FOR
HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING ANY
THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A COLD FRONT WILL APPROACH THIS AFTERNOON...AND PASS TO THE SOUTH
TONIGHT.
AT 1815Z...RADAR SHOWED BKN LINE OF STRONG TO SEVERE TSTMS
EXTENDING ACROSS NW NJ...THE LOWER HUDSON VALLEY AND CT...WITH
MORE ISOLD ACTIVITY ALONG THE NORTH SHORE OF LONG ISLAND...ALL
MOVING E TO E-SE. MAIN IMPACTS BEFORE 21Z WILL BE JUST NORTH OF
THE NYC METRO TERMINALS AT KHPN/KBDR...BUT GUST FRONT FROM THESE
STORMS SHOULD ALSO IMPACT KTEB/KLGA WITH A WIND SHIFT FROM THE
NW. MAIN IMPACT TO NYC METRO TERMINALS WILL ARRIVE AFTER 21Z AS
STORMS OVER EASTERN/NE PA AND FAR WRN NJ APPROACH. THREAT OF
STRONG WINDS AND CONVECTIVE LLWS...HAIL AND HEAVY RAINFALL
EXISTS...AND COULD CONTINUE UNTIL 00Z-01Z.
MAINLY VFR LATER THIS EVENING AFTER CONVECTION WEAKENS AND PASSES
TO THE SOUTH...WITH LIGHT N FLOW DEVELOPING AFTER COLD FROPA.
CANNOT RULE OUT SOME PATCHY GROUND FOG AT OUTLYING TERMINALS.
...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: MAIN IMPACTS FROM TSTMS 22Z-01Z.
KLGA FCSTER COMMENTS: MAIN IMPACTS FROM TSTMS 22Z-01Z.
KEWR FCSTER COMMENTS: MAIN IMPACTS FROM TSTMS 21Z-24Z.
KTEB FCSTER COMMENTS: MAIN IMPACTS FROM TSTMS 21Z-24Z.
KHPN FCSTER COMMENTS:
KISP FCSTER COMMENTS: MAIN IMPACTS FROM TSTMS 23Z-01Z.
OUTLOOK FOR 18Z THU THROUGH MON...
.THU AFTERNOON-EVENING...VFR. ISOLD SHOWERS POSSIBLE.
.LATE THU NIGHT-SAT MORNING...SCAT SHOWERS AND MVFR CONDS
POSSIBLE...BEST CHANCE AT SOUTHERN/COASTAL TERMINALS.
.SAT AFTERNOON-SUN NIGHT...VFR.
.MON...CHANCE OF TSTMS.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE AT TIMES ACROSS OUTER OCEAN
WATERS IN THE SHORT TERM THROUGH THURSDAY NIGHT. HOWEVER...KEPT
OCEAN SEAS BELOW 5 FT SINCE WAVEWATCH INITIALLY ABOUT A FOOT TOO
HIGH COMPARED TO OBS.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/4 TO 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.CLIMATE...
NEWARK HAS BROKEN THEIR RECORD HIGH TODAY WITH A MAX OF 103 DEGREES SO
FAR. LA GUARDIA ARPT HAS HIT 100 DEGREES...WHICH TIES THEIR RECORD.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ005>010.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ067>075-
078>081-176>179.
NJ...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NJZ002-004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...GOODMAN
MARINE...24/JM
HYDROLOGY...24/JM
CLIMATE...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
102 PM EDT WED JUL 18 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO THE REGION
THIS AFTERNOON AND SOUTH OF THE REGION LATE TONIGHT INTO THURSDAY.
THE FRONT WILL THEN STALL WITH A WEAK AREA OF LOW PRESSURE MOVING
ALONG IT. LOW PRESSURE PASSES TO THE SOUTH ON FRIDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH THROUGH THE WEEKEND. ANOTHER
COLD FRONT WILL TRACK ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED GRIDS TO INCREASE MAX TEMPS. HEAT ADVISORY HAS BEEN
EXPANDED TO ALL BUT SOUTHERN MIDDLESEX/NEW LONDON COUNTIES PER
OBS. ADDED ENHANCED SEVERE TSTM WORDING TO THE FORECAST AS SPC HAS
ISSUED SEVERE TSTM WATCH TIL 9PM. MAX TEMPS HAVE LIKELY BEEN
REACHED IN MOST PLACES AS TSTMS ARE DEVELOPING RAPIDLY. SOME
RECORD HIGHS NEARED OR EXCEEDED...SEE CLIMATE SECTION BELOW.
OTHERWISE...A SLOW MOVING COLD FRONT FROM THE NORTH WILL MOVE INTO
THE REGION THIS AFTERNOON. WITH THE REGION BEING ON THE NE EDGE OF
A VERY HOT AIR MASS...DAY STARTS OUT VERY WARM AND LARGE CAPE IN
THE 2000 TO 4000 J/KG RANGE IS EXPECTED TO BUILD WITH DIURNAL
WARMING. SHEAR OF 30 KT 0-6KM WITH WET BULB ZERO HEIGHTS OF 13-14
KFT. MENTIONED GUSTY WINDS AND SMALL HAIL WITH SOME CELLS HAVING A
SLIGHT CHANCE OF GOING SEVERE.
BEFORE COVERAGE OF SHOWERS AND THUNDERSTORMS BECOMES
WIDESPREAD...AT LEAST SOUTHERN PORTIONS OF THE REGION WILL SEE
ENOUGH SUN TO HAVE HIGHS WELL INTO THE 90S AND WITH VERY MOIST
AIR MASS CONVEYED BY PWATS NEAR 2 INCHES AND DEWPOINTS IN THE LOWER
70S...HEAT INDICES ARE EXPECTED TO BE NEAR 100 DEGREES FOR NEW
YORK CITY AS WELL AS URBAN SECTIONS OF SOUTHERN WESTCHESTER...MOST
OF NE NJ AND WESTERN LONG ISLAND.
FARTHER UP NORTH IN LOWER HUDSON VALLEY AND SOUTHERN CT WILL DEPEND
ON HOW FAST CONVECTION DEVELOPS AND THE INHERENT MITIGATION OF
DIURNAL WARMTH ASSOCIATED WITH EXPANDING CIRRUS CLOUD SHIELD OF
CONVECTION. RIGHT NOW...KEPT THEM LOWER WITHOUT HEAT ADVISORY BUT
HEAT INDICES ARE EXPECTED TO REACH MID TO UPPER 90S BEFORE
CONVECTION INCREASES SUBSTANTIALLY IN COVERAGE THIS AFTERNOON.
WILL START OFF THE HEAT ADVISORY LATE THIS MORNING BY 10 AM SINCE WE
WILL BE COMMENCING THE DIURNAL PERIOD AT A MUCH WARMER TEMPERATURE
THIS MORNING. MOST MODELS START TO BRING IN THE SHOWERS AND
THUNDERSTORMS BY 18Z ACROSS THE NORTHERN TIER AND BY 00Z ACROSS THE
ENTIRE AREA. ONLY EXCEPTION IS ECMWF WHICH HAS CONSISTENTLY HELD
BACK CONVECTION FOR LONG ISLAND UNTIL AFTER 00Z THU.
BASED ON MESOSCALE MODELS OF HRRR AND NSSL WRF...STRENGTHENING
CONVECTIVE CELLS START FIRING UP ALONG ACROSS THE ALLEGHENY PLATEAU
AND THE HUDSON VALLEY AROUND 17Z AFTER WHICH THEY WILL BE ON A
SOUTHEAST TRACK GOING INTO THE LOCAL FORECAST REGION. FURTHER
DEVELOPMENT OF CONVECTION COULD ALSO OCCUR FROM CONVERGENCE ALONG
THE SEA BREEZE BOUNDARY ESPECIALLY WITH ANY OUTFLOW BOUNDARIES FROM
CONVECTION MOVING IN FROM THE NORTH AND WEST. WIND SHEAR OF 25 TO 30
KT FROM 0-6 KM WILL ALLOW FOR SOME THUNDERSTORMS TO PRODUCE HAIL AND
GUSTY WINDS. PWATS NEAR 2 INCHES SO HEAVY RAIN ALSO CAN BE EXPECTED
WITH THUNDERSTORMS THAT FORM. THIS IS CONSIDERED ESPECIALLY SINCE
THE FLOW WILL BE NEARLY PARALLEL FROM LOW TO MID LEVELS WHICH WOULD
ALLOW FOR TRAINING OF CELLS. THE CONVECTIVE MODE LOOKS TO BE SQUALL
LINE TO BOW ECHOES.
THERE IS A MODERATE RISK FOR RIP CURRENTS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...RELATIVELY BETTER SHEAR ARRIVES WITH WINDS ALOFT AT 250MB
INCREASING AN EXTRA 10KT...PROMOTING GREATER DIVERGENCE. SOME
GREATER HEIGHT FALLS AT 500MB WILL ALSO IMPLY SOME GREATER SYNOPTIC
FORCING. THEREFORE EVEN THOUGH CAPE WILL BE ON A LOWERING
TREND...SOME THUNDERSTORMS WILL STILL MAINTAIN STRONG INTENSITIES
WITH HEAVY RAIN ALSO STILL POSSIBLE AS PWATS REMAIN NEAR 2 INCHES.
THE FRONT MOVES THROUGH LATE IN THE EVENING AND THEN SOUTH OF LONG
ISLAND GOING INTO THURSDAY. THE FRONT STALLS WITH A WEAK AREA OF LOW
PRESSURE MOVING IT. SOUTHERN PORTIONS OF THE FORECAST AREA COULD SEE
SOME LINGERING SHOWERS FROM TIME TO TIME ON THURSDAY AS A RESULT.
POPS ARE AT SLIGHT CHANCE WITH MODEL UNCERTAINTY DUE TO DIFFERENCES
IN QPF FIELDS AND RUN TO RUN INCONSISTENCY. IN THE UPPER LEVELS AT
500MB...THE AREA WILL BE IN A NW FLOW WITH A LONGWAVE TROUGH SETTING
UP ACROSS THE NORTHEAST. WENT WITH MORE OF THE COOLER GUIDANCE FOR
HIGHS CONSIDERING THE MORE EASTERLY FLOW. NOT EXPECTING ANY
THUNDERSTORMS WITH THIS ACTIVITY WITH MORE STABLE SFC CONDITIONS
FORECAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A MEAN TROUGH WILL REMAIN OVER THE NE CONUS THROUGH THE PERIOD WHILE
A PERSISTENT AND STRONG RIDGE ALOFT REMAINS ENTRENCHED OVER THE
PLAINS AND ROCKIES.
COLD FRONT SLOWLY PRESSES SOUTHWARD THROUGH THE MID ATLANTIC STATES
THROUGH FRIDAY WITH CANADIAN HIGH PRES BUILDING IN FROM THE N. AN
AREA OF LOW PRES IS FORECAST TO DEVELOP ON THE FRONT THU NIGHT AND
PASS TO THE S FRI MORNING WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH ALOFT. AN EASTERLY FLOW WILL MOISTEN LOW LEVELS WITH THE CHC
OF SHOWERS ON FRI. MODELS HAVE BEEN CONSISTENT WITH THIS FOR THE
LAST DAY...SO HAVE ADDED CHC POPS TO THE FORECAST. ABUNDANT CLOUD
COVER AND ONSHORE FLOW WILL RESULT IN A MUCH COOLER DAY ACROSS THE
AREA WITH HIGHS ONLY EXPECTED TO REACH THE UPPER 70S AT MOST
LOCATIONS. AS THE FRONT SINKS FURTHER S LATER FRI AND FRI NIGHT
DRIER AND MORE STABLE AIR WILL WORK IN FROM THE N AND E WITH DRY
WEATHER AND SEASONABLE THROUGH THE WEEKEND.
WAA ENSUES EARLY NEXT WEEK WITH H85 TEMPS RISING INTO THE UPPER
TEENS ON MON RESULTING IN TEMPS RISING A FEW DEGREES ABOVE NORMAL
LEVELS MON. PRE-FRONTAL TROUGH MAY TRIGGER ISOLD-SCT STORMS MON AFTN
AS COLD FRONT APPROACHES FROM THE NW. TYPICAL GFS IS FASTER THAN THE
EC WITH THE FROPA SO HAVE COMPROMISED THE TIMING WITH IT COMING
THROUGH TUE MORNING. DRY AND SEASONABLE WEATHER COURTESY OF HIGH
PRES THEN BUILDS BACK IN OVER THE AREA.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A COLD FRONT WILL APPROACH THIS AFTERNOON...AND PASS TO THE SOUTH
TONIGHT.
MAINLY VFR OUTSIDE OF TSTMS...ALTHOUGH HZ IS RESTRICTING VSBY TO
5SM AT KGON. HYBRID SEA BREEZE/SW FLOW ACROSS COASTAL TERMINALS
THIS AFTERNOON. WINDS BECOMING NW AND WEAKENING IN WAKE OF COLD
FRONTAL PASSAGE LATE THIS EVENING/TONIGHT.
TSTM DEVELOPMENT THIS AFTERNOON/EVENING HAS SOME UNCERTAINTIES.
IT NOW APPEARS THAT THERE MAY BE MULTIPLE ROUNDS OF STORMS...ONE
EARLY THIS AFTERNOON AS STORMS DEVELOP INVOF A PRE-FRONTAL LOW
PRESSURE TROUGH ALREADY IN PLACE OVER THE REGION...THEN A SECOND
ROUND LATE IN THE DAY AS THE COLD FRONT ENTERS THE AREA. TSTM FCST
IN AMENDED TAF ADDRESSES ON THE FIRST ROUND...AND THE 18Z TAF
WILL BETTER ADDRESS THE SECOND ROUND AS CONFIDENCE LEVEL INCREASES
ONE WAY OR THE OTHER. THREAT OF STRONG WINDS AND CONVECTIVE
LLWS...HAIL AND HEAVY RAINFALL EXISTS WITH STRONGER CONVECTION.
CONVECTION EXPECTED TO TAPER AND WEAKEN THIS EVENING.
MAINLY VFR IN WAKE OF COLD FROPA...EXCEPT PATCHY GROUND FOG ACROSS
OUTLYING TERMINALS.
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: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
HYBRID SEA BREEZE/SW FLOW THIS AFTERNOON.
KLGA FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
KEWR FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING THROUGH THE AFTERNOON.
KHPN FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 16Z.
OCCASIONAL GUSTS POSSIBLE FROM LATE MORNING THROUGH THE AFTERNOON.
KISP FCSTER COMMENTS: MODERATE CONFIDENCE ON CONVECTION OCCURRING
AT SOME POINT DURING THE AFTERNOON...BUT LOW CONFIDENCE IN EXACT
TIMING IN THE TAFS. ISOLATED CONVECTION POSSIBLE AS EARLY AS 17Z.
HYBRID SEA BREEZE/SW FLOW THIS AFTERNOON.
OUTLOOK FOR 12Z THU THROUGH SUN...
.THU-THU EVENING...VFR. SCT SHOWERS POSSIBLE.
.LATE THU NIGHT-SAT MORNING...MVFR CIGS POSSIBLE...BEST CHANCE AT
SOUTHERN/COASTAL TERMINALS.
.SAT AFTERNOON-SUN...VFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS ARE POSSIBLE AT TIMES ACROSS OUTER OCEAN
WATERS IN THE SHORT TERM THROUGH THURSDAY NIGHT. HOWEVER...KEPT
OCEAN SEAS BELOW 5 FT SINCE WAVEWATCH INITIALLY ABOUT A FOOT TOO
HIGH COMPARED TO OBS.
MARGINAL SCA CONDS ARE POSSIBLE ON THE OCEAN WATERS FRI/FRI NIGHT
WITH AN INCREASING EASTERLY FLOW BETWEEN HIGH PRES BUILDING IN FROM
THE N AND LOW PRES PASSING TO THE S. A RELATIVELY LIGHT SE-S FLOW
WILL THEN PREVAIL WITH SUB-ADVY CONDS THEREAFTER. HAVE CUT A FT OFF
OF WAVEWATCH GUIDANCE THROUGH THE PERIOD AS IT CONTINUES TO RUN
HIGH.
&&
.HYDROLOGY...
NO PRECIPITATION IS EXPECTED INTO THIS MORNING.
FLASH FLOODING IS POSSIBLE WITH ANY TRAINING CONVECTION THIS
AFTERNOON AND EVENING AS PWATS INCREASE TO AROUND 2 INCHES AND
STEERING FLOW NEARLY ALIGNS WITH FRONTAL BOUNDARY. A BASIN AVERAGE
QPF OF AROUND 1/4 TO 1/2 INCH IS POSSIBLE ACROSS THE AREA...WITH
LOCALIZED AMOUNTS IN EXCESS OF 2 INCHES POSSIBLE WITH ANY TRAINING
CONVECTION.
&&
.CLIMATE...
NEWARK HAS BROKEN THEIR RECORD HIGH TODAY WITH A MAX OF 103 DEGREES SO
FAR. LA GUARDIA ARPT HAS HIT 100 DEGREES...WHICH TIES THEIR RECORD.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ005>010.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ067>075-
078>081-176>179.
NJ...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NJZ002-004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...GS
SHORT TERM...JM LONG TERM...24
AVIATION...GOODMAN/NV
MARINE...24/JM
HYDROLOGY...24/JM
CLIMATE...TM/GS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
612 PM EDT WED JUL 18 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH THE
WEEK...WHILE A WEAK TROUGH OF LOW PRESSURE LINGERS INLAND THROUGH
FRIDAY. A COLD FRONT WILL APPROACH FROM THE NORTH SATURDAY...YET
DISSIPATE SUNDAY AS THE ATLANTIC HIGH BUILDS BACK INTO THE AREA.
A LEE SIDE TROUGH WILL DEVELOP AGAIN FOR NEXT TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RECENTLY UPDATED OUR GRIDDED AND TEXT PRODUCTS TO KEEP UP WITH TRENDS
IN TEMPERATURES AND CONVECTIVE TRENDS. OVERALL IT/S LOOKING LIKE
POTENTIAL FOR SCATTERED SHOWERS AND TSTMS IS WANING. OUR WESTERN ZONES
HAVE LITTLE IN THE WAY OF CUMULUS TOWERS PER LATEST VISIBLE DESPITE
GOOD LATE DAY INSOLATION. THE BULK OF THE CONVECTION IS FIRING ON THE
N SIDE OF THE UPPER LOW IN THE LEE SIDE SURFACE TROUGH TO THE NW OF
THE FORECAST AREA.
THE OTHER REGION OF TSTMS WERE DOWN TO THE S OF THE ALTAMAHA RIVER
AND THE RUC RAPID REFRESH WHICH DEPICTS THIS ACTIVITY...GENERALLY
WEAKENS IT IN THE NEXT 1-2 HOURS. OVERALL WE HAVE DIMINISHED POPS TO
15-20 PERCENT IN MANY AREAS. WE MAINTAINED CHANCE POPS TO THE S OF
I-16 IN GEORGIA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THE PERSISTENT TUTT FEATURE WILL GRADUALLY DISSIPATE ON
THURSDAY...LEAVING A BROAD UPPER TROUGH ALONG THE EAST COAST AND AN
ATLANTIC RIDGE OTHERWISE IN CONTROL OF THE PATTERN ALOFT. THE
SURFACE PATTERN WILL BE DEFINED BY AN INLAND TROUGH LINGERING ACROSS
THE CENTRAL CAROLINAS THROUGH FRIDAY...WHILE ATLANTIC HIGH PRESSURE
STRETCHES TOWARD THE COASTLINE INTO THE WEEKEND.
DECENT DEEP LAYER MOISTURE WILL REMAIN OVER THE MID ATLANTIC AND
SOUTHEAST STATES...AS SEEN IN PWAT VALUES NEAR OR SLIGHTLY ABOVE 2
INCHES. WHEN COMBINED WITH WARM TEMPERATURES PEAKING IN THE LOW TO
MID 90S AND MODERATE INSTABILITY...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP BY EARLY AFTERNOON EACH DAY. THERE WILL
BE NUMEROUS BOUNDARIES FOR INITIATING AND ENHANCING
CONVECTION...INCLUDING THE SEA BREEZE...LAKE BREEZES FROM LAKE
MOULTRIE/MARION...DIFFERENTIAL HEATING BOUNDARIES...AS WELL AS
OUTFLOWS THAT DEVELOP ONCE CONVECTION GETS UNDERWAY. A COLD FRONT
WILL BE DESCENDING AND LIKELY STALLING TO THE NORTH BY
SATURDAY...AND CONVECTIVE COVERAGE WILL LIKELY INCREASE ACROSS
NORTHERN AREAS AS A RESULT. EXPECT MAINLY PULSE TYPE STORMS THURSDAY
AND FRIDAY...EXCEPT WHERE BOUNDARY COLLISIONS OCCUR AND POTENTIALLY
INITIATE MULTICELL CLUSTERS. ISOLATED THUNDERSTORMS COULD BECOME
SEVERE...WITH THE MAIN THREATS BEING HEAVY RAINFALL AND WET
DOWNBURSTS PRODUCING LOCALLY DAMAGING WINDS. DEPENDING ON THE
PROXIMITY OF THE FRONT ON SATURDAY...CONVECTION COULD BECOME MORE
ORGANIZED. WILL CONTINUE TO INDICATE PRECIPITATION CHANCES IN THE 30
TO 40 PERCENT RANGE THURSDAY...INCREASING INTO THE 40 PERCENT RANGE
TO NEAR 50 PERCENT FRIDAY AND SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE COLD FRONT TO THE NORTH WILL DISSIPATE SUNDAY...AS ATLANTIC
RIDGING BOTH AT THE SURFACE AND ALOFT BUILDS ACROSS THE AREA INTO
MONDAY. HOWEVER...THE RIDGE ALOFT RETROGRADES WESTWARD FROM THE
ATLANTIC INTO THE NORTHERN GULF BY TUESDAY AND WEDNESDAY...WHILE
AT THE SAME TIME A SURFACE TROUGH AGAIN SETS UP TO THE LEE OF THE
APPALACHIANS. WHILE HEIGHTS ALOFT ARE HIGHER DURING THIS TIME...
THERE IS STILL A WEST AND NORTHWEST FLOW ALOFT TO ALLOW FOR
UPSTREAM CONVECTION TO FORM AND INTERACT WITH LOW LEVEL MESOSCALE
BOUNDARIES. THUS...FEEL OBLIGATED TO HOLD ON TO SLIGHT CHANCE OR
EVEN CHANCE POPS THROUGHOUT THE ENTIRE LONG TERM PERIOD.
CONVECTION WILL BE DIURNALLY DRIVEN...WITH ISOLATED PULSE SEVERE
WEATHER NOT OUT OF THE QUESTION WITHIN THE AFOREMENTIONED WEST AND
NORTHWEST FLOW ALOFT. TEMPERATURES WILL BE NEAR NORMAL VALUES.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
IT APPEARS RISK OF SHOWERS/TSTMS DIMINISHING AT THE TERMINALS WITH
STORMS NOW DISSIPATED. MAINLY VFR UNTIL POSSIBLY ANOTHER ROUND OF
DIURNAL CONVECTION ON THU AFTERNOON.
EXTENDED AVIATION OUTLOOK...THE RISK FOR DIURNAL SHRA/TSRA WILL BE
ENHANCED THURSDAY AND FRIDAY DUE TO AN INLAND TROUGH OF LOW
PRESSURE...AND AGAIN ON SATURDAY IN ADVANCE OF AN APPROACHING COLD
FRONT. PERIODIC MVFR OR LOWER CONDITIONS WILL OCCUR AS A RESULT OF
THE CONVECTION.
&&
.MARINE...
AN ENHANCED GRADIENT BETWEEN AN INLAND TROUGH AND ATLANTIC HIGH
PRESSURE WILL SUPPORT SLIGHTLY HIGHER WINDS AND SEAS ACROSS THE
MARINE ZONES. A TYPICAL SOUTHWEST FLOW WILL PREVAIL THROUGH THE
ENTIRE PERIOD...WITH VEERING AT NIGHT UNDER LAND BREEZE
CIRCULATIONS...AND BACKING DURING THE DAYTIME HOURS WITH THE SEA
BREEZE. THERE WILL BE PERIODIC SURGES...EITHER FROM THE SEA BREEZE
DEVELOPMENT AND/OR FROM NOCTURNAL LOW LEVEL JETTING. AS A
RESULT...WINDS WILL BE AS HIGH AS HIGH AS 15 KT...EVEN
OCCASIONALLY CLOSE TO 20 KT. SEAS WILL GENERALLY HOLD IN THE 2 TO
4 FT RANGE. A WEAK COLD FRONT WILL APPROACH FROM THE NORTH BY THE
WEEKEND...AND WITH WEAK LOW PRESSURE DEVELOPING ALONGSIDE...EXPECT
A WEAKENING PRESSURE GRADIENT TO RESULT.
RIP CURRENTS...A PERSISTENT 2 FT 10 SEC SWELL IS EVIDENT FROM
LOCAL BUOY REPORTS...AND CONSIDERING THE NEW MOON ON THURSDAY...
HAVE EXTENDED A MODERATE RISK FOR RIP CURRENTS FOR ALL AREA
BEACHES THURSDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...79
LONG TERM...RJB
AVIATION...BDC/79
MARINE...JRL/RJB/79
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
153 PM EDT WED JUL 18 2012
.PREV DISCUSSION...
UPDATE...
/ISSUED 1046 AM EDT WED JUL 18 2012/
NOT MUCH IN THE WAY OF CHANGES TO THE FORECAST THIS MORNING.
CLOUD COVERAGE HAS SLOWED HOURLY TEMPS SO DID MAKE ADJUSTMENTS TO
HOURLY TRENDS. THERE ARE SOME BREAKS IN THE CLOUDS ACROSS THE CWA
SO DID NOT ADJUST MAX TEMPS FOR NOW. AS PREVIOUSLY NOTED
THOUGH....RAIN TODAY WILL HAVE AN IMPACT ON WHETHER ALL SITES
REACH THEIR FORECAST MAX TEMPS...TO LOCALIZED THOUGH FOR
ADJUSTMENTS AT THIS TIME.
HAVE ALREADY SEEN ACTIVITY ALL MORNING...BUT STILL EXPECTING MORE
COVERAGE BY THIS AFTERNOON...UNCERTAINTY THOUGH IN BEING ABLE TO
NARROW DOWN TIMING ANY FURTHER. WRF NMM AND HRRR /ALTHOUGH THE
HRRR RUN ISNT FOR THE MOST RECENT TIME PERIOD/ SUGGEST BEST
CHANCES OF RAIN THROUGH ABOUT MID AFTERNOON WHEREAS THE LOCAL WRF
MODEL SUGGESTS THE BEST CHANCE OF POPS DURING THE LATE AFTERNOON
INTO THE EVENING.
11
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
/ISSUED AT 350 AM EDT WED JUL 18 2012/
MODELS ARE MAINTAINING GOOD AGREEMENT THROUGH 48 HOURS. THE H5 LOW
OVER THE GA/FL BORDER WILL DRIFT INTO SOUTH/CENTRAL GEORGIA TODAY
AND THEN STALL AND DISSIPATE...OPENING UP INTO A WEAK TROUGH THAT
WILL REMAIN OVER THE CWA ON THURSDAY. THIS WILL CONTINUE TO BRING
ATLANTIC MOISTURE INTO THE CWA THROUGH THE SHORT TERM. WEAK UPPER
IMPULSES WILL CONTINUE ACROSS THE REGION THROUGH THE SHORT TERM AS
WELL...AND GIVEN THE AMOUNT OF COVERAGE OF CONVECTION OVER THE PAST
2 DAYS...SEE NO REASON WHY THERE WOULD BE LESS TODAY...THEREFORE
WILL INCREASE POPS TO LIKELY THIS AFTERNOON. MODELS ARE GIVING 50/60
POPS ON THURSDAY AND AGAIN SEE NO REASON TO GO LESS. AS FOR THE
NIGHTTIME PERIODS...AS WITH EARLY THIS MORNING...CONVECTION REMAINS
A POSSIBILITY. POCKETS OF WARM AIR COUPLED WITH THE UPPER
IMPULSES...WILL BE ENOUGH TO AID IN ISOLATED CONVECTION PAST
MIDNIGHT SO WILL CONTINUE WITH 20 POPS AFTER MIDNIGHT TONIGHT AND
THURSDAY NIGHT.
TEMPS ARE TRICKY AS AREAS THAT RECEIVE RAIN EARLY MAY STRUGGLE TO
GET OUT OF THE UPPER 80S...HOWEVER A DELAY IN RAIN OR NO RAIN AT ALL
COULD PUSH TEMPS INTO THE LOW AND MID 90S. WILL THEREFORE NOT STRAY
TOO FAR FROM GUIDANCE...WHICH IS VERY CLOSE TO PERSISTENCE...AND GO
WITH MAX TEMPS IN THE LOW TO MID 90S BOTH TODAY AND THURSDAY.
NIGHTTIME LOWS WILL REMAIN QUITE WARM AND MUGGY.
17
LONG TERM /FRIDAY THROUGH TUESDAY/...
/ISSUED AT 350 AM EDT WED JUL 18 2012/
EXTENDED PERIOD MODEL AGREEMENT DECENT WITH REMAINS OF UPPER LEVEL
LOW PRESSURE SYSTEM AND ASSOCIATED SURFACE TROUGH POSITIONED
ACROSS NORTH AND CENTRAL GEORGIA ON FRIDAY AS SURFACE LOW DEVELOPS
OVER THE CAROLINAS. THIS LOW WILL CONTINUALLY ADD MOISTURE TO AN
ALREADY MOIST ENVIRONMENT...AND EXPECTING GOOD PRECIP
COVERAGE...ESPECIALLY ACROSS NORTH GEORGIA. AS A RESULT...HAVE
GONE WITH LIKELY POPS NORTH...DIMINISHING TO GOOD CHANCE POPS
FURTHER SOUTH. BY SATURDAY...FRONTAL BOUNDARY SAGGING OUT OF THE
TENNESSEE VALLEY IS EXPECTED TO PUSH INTO NORTH AND CENTRAL
GEORGIA...KEEPING AMPLE MOISTURE ALIGNED ALONG THE FRONT. HAVE
GONE WITH LIKELY POPS ACROSS THE MIDDLE CWA...HIGHLIGHTING FRONT
PROGRESSION. THIS AREA OF LIKELY POPS IS SUBJECT TO CHANGE AS
SATURDAY APPROACHES DUE TO MODEL UNCERTAINTY WITH TIMING AND
LOCATION OF THE BOUNDARY. FOR FRIDAY AND SATURDAY...ENHANCED
CONVECTION IS EXPECTED TO BE COUPLED WITH DIURNAL HEATING...SO
HAVE DIMINISHED POPS SOMEWHAT INTO THE OVERNIGHT HOURS.
BY EARLY NEXT WEEK...HIGH PRESSURE OVER THE WESTERN ATLANTIC
ATTEMPTS TO NOSE BACK INTO THE REGION...WITH THE FLOW AROUND THE
RIDGE PULLING GULF MOISTURE INTO THE STATE. MEANWHILE...MODELS
SHOWING ANOTHER SHORTWAVE PUSHING INTO THE REGION WITH LEE SIDE
SURFACE TROUGH SETTING UP ALONG THE APPALACHIANS ASSOCIATED WITH
LOW PRESSURE OVER THE CANADIAN MARITIMES. AS A RESULT OF THESE
FEATURES...HAVE GENERALLY GONE WITH CHANCE POPS THROUGH THE
REMAINDER OF THE EXTENDED FORECAST PERIOD.
AS FOR TEMPERATURES...MODELS CONSISTENT WITH SHOWING COOLER 850MB
TEMPERATURES...SOMEWHERE IN THE 16.5 TO 17.5 RANGE...INTO THE
WEEKEND...AND WITH INCREASED PRECIP ACTIVITY AND PLENTY OF CLOUD
COVER...HAVE TENDED TOWARDS SLIGHTLY COOLER AFTERNOON HIGH
TEMPERATURES CLOSER TO SEASONAL NORMS. BY NEXT WEEK...WITH FLOW
OFF THE NORTHERN GULF ANTICIPATED BY MONDAY...850MB TEMPS WARM
2-2.5C...AND HAVE GONE WITH LOW 90 HIGHS MONDAY THROUGH WEDNESDAY.
WITH THE MOIST ENVIRONMENT PERSISTING THROUGH THE
WEEK...HEAVY RAIN STILL REMAINS A THREAT IN CONVECTION. FORECAST
SOUNDINGS SHOWING NEAR 2.0 INCH PWS INTO THE WEEKEND. QPF FOR
FRIDAY THROUGH SUNDAY MORNING IS EXPECTED TO BE WIDESPREAD 1-1.5
INCHES...WITH LOCALLY HEAVIER AMOUNTS.
31
AVIATION...
12Z UPDATE...
/ISSUED 729 AM EDT WED JUL 18 2012/
NEW CONVECTION ALONG THE AL/GA BORDER WEST OF ATL PROBABLY IN
RESPONSE TO OUTFLOW AND THE UPPER LOW. THIS COULD BE THE START OF
ANOTHER ACTIVE DAY AND WILL MAINTAIN PREDOMINANT TSRA OVER THE
FORECAST AREA BY 18Z WITH VCSH BEGINNING AROUND 14Z. CONVECTION
SHOULD DISSIPATE WITH THE LOSS OF DAYTIME HEATING TONIGHT. WINDS
WILL REMAIN ON THE WEST SIDE LESS THAN 10 KTS...BECOMING CALM
TONIGHT.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON TIMING OF CONVECTION.
HIGH ON ALL OTHER ELEMENTS.
17
&&
.AVIATION...
18Z UPDATE...
CONVECTION ALREADY STARTED ACROSS NORTH GEORGIA AND EXPECT IT TO
IMPACT TAF SITES THIS AFTERNOON. TIMING IS UNCERTAIN THOUGH AND IS
THE NEAR TERM CHALLENGE. THINK BEST CHANCES ARE IN THE 20-23Z
RANGE ACROSS THE NORTHERN TAF SITES AND 22-02Z ACROSS THE SOUTHERN
TAF SITES. EVEN THOUGH THERE HAS BEEN SOME VARIABILITY IN THE
WINDS...THEY SHOULD REMAIN ON THE WEST SIDE...EXCEPT FOR IMPACTS
FROM OUTFLOW BOUNDARIES. SOME SITES SAW LOW STRATUS THIS MORNING
AND SOME CONCERN FOR THIS AGAIN TOMORROW MORNING...CONFIDENCE TOO
LOW TO MENTION IN THE TAF THOUGH AT THIS POINT.
//ATL CONFIDENCE...18Z UPDATE...
HIGH ON WIND...EXCEPT NEAR TSRA. MEDIUM CONFIDENCE ON VSBYS AND
CIGS. LOW CONFIDENCE ON TIMING OF TSRA THIS AFTERNOON.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 71 93 73 / 60 40 60 30
ATLANTA 92 72 92 73 / 60 40 60 30
BLAIRSVILLE 85 67 85 69 / 60 40 60 30
CARTERSVILLE 92 70 92 71 / 60 40 60 30
COLUMBUS 94 73 93 73 / 60 40 60 30
GAINESVILLE 91 71 91 72 / 60 40 60 30
MACON 94 72 94 73 / 60 40 60 30
ROME 93 71 93 73 / 60 40 60 30
PEACHTREE CITY 92 71 92 71 / 60 40 60 30
VIDALIA 92 74 92 75 / 60 40 60 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...11
SHORT TERM...17
LONG TERM....31
AVIATION...11
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
301 PM CDT WED JUL 18 2012
.MESOSCALE DISCUSSION...
300 PM CDT
CONTINUE TO SEE PULSE TYPE STORMS FLARING UP THIS AFTERNOON IN THE
AXIS OF GREATEST INSTABILITY WHICH EXTENDS FROM NORTH CENTRAL
INDIANA WNW ACROSS MOST OF OUR CWA TO NORTHEASTERN IOWA. DEEP LAYER
SHEAR REMAINS ANEMIC WITH UNIDIRECTIONAL WESTERLY FLOW AROUND
15-20KT WHICH SHOULD CONTINUE TO RESULT IN MINIMAL STORM
ORGANIZATION...HOWEVER GIVEN THE MODERATELY STRONG INSTABILITY AND
FAIRLY LARGE DOWNDRAFT CAPE VALUES POTENTIAL EXISTS FOR WET
MICROBURSTS THROUGH EARLY EVENING WITH THE MOST INTENSE ONES
POTENTIALLY PRODUCING GENERALLY MARGINALLY SEVERE WIND IN ISOLATED
LOCATIONS. POTENTIAL FOR SEVERE HAIL APPEARS LOW GIVEN WARM
THERMODYNAMIC PROFILES AND WEAK SHEAR. VERY HIGH PRECIPITABLE WATER
VALUES SHOULD ALLOW STORMS TO BE VERY EFFICIENT RAIN PRODUCERS.
IZZI
&&
.DISCUSSION...
558 AM CDT
LATEST RADAR/SURFACE OBS SHOW FRONTAL BOUNDARY STRETCHING FROM
NEAR DUBUQUE TO MORRIS TO NEAR VALPARAISO AT 530 AM WHICH HAD
SURGED SOUTHWARD OVER THE LAST HOUR. RADAR MOSAIC SHOWS ANOTHER
BOUNDARY FROM NEAR JANESVILLE TO CHICAGO. THIS BOUNDARY IS
COINCIDENT WITH SPOTTY CONVECTION NEAR MADISON AND A FEW SMALL
CELLS OVER SOUTHERN LAKE MICHIGAN. THE MAIN AREA OF CONVECTION
REMAINS MORE CLOSELY TIED TO THE MID LEVEL BAROCLINIC ZONE RUNNING
FROM THE TWIN CITIES INTO CENTRAL LOWER MICHIGAN. HIGH RES NEAR
TERM GUIDANCE SHOWS SOME INTERESTING SOLUTIONS IN TERMS OF
WINDS/BOUNDARY PLACEMENT INTO THE AFTERNOON. THE RAP AND THE HRRR
BOTH DEPICT THE CURRENT EXPANSE OF NORTHEAST WINDS BEHIND THE
FIRST BOUNDARY BUT THEN TURN WINDS ACROSS MUCH OF THE AREA
SOUTHWESTERLY THIS MORNING WITH A BOUNDARY SETTING UP FROM NEAR
ROCKFORD TO JOLIET TO RENSSELAER OR SO. THIS IS AN INTERESTING
PROGRESSION OF THINGS IF THIS INITIAL BOUNDARY WERE THE TRUE COLD
FRONT. LOCAL WRF SHOWS A SIMILAR THOUGH LESS PRONOUNCED TREND.
ASSUMING THIS BOUNDARY IS THE COLD FRONT IT IS POSSIBLE THAT IT
DOES MOVE BACK NORTHWARD INTO THE MIDDLE OF THE DAY IN RESPONSE TO
THE UPPER TROUGH MOVING TOWARD THE MID/UPPER MISSISSIPPI RIVER
VALLEY GIVEN THAT THE WESTERN EXTENT OF THE FRONT IS IN NORTHWEST
IOWA CLOSER TO WHERE THE UPPER TROUGH AXIS IS NOW. ANOTHER
SCENARIO IS THAT THE INITIAL BOUNDARY WAS SOME SORT OF SHALLOW
OUTFLOW WHICH MIXES OUT THIS MORNING AND THE MAIN FRONT IS THE
BOUNDARY CLOSER TO THE CHICAGO AREA DESCRIBED ABOVE. LOOKING AT
THE VAD WIND PROFILES FROM LOT AND MKX THEY SHOW SIMILAR DEPTHS OF
NORTHEAST WINDS SO IT SEEMS THAT THIS IS A LESS LIKELY SCENARIO.
WILL KEEP THE FORECAST MORE OR LESS AS-IS FOR NOW. OTHERWISE...SPOTTY
SHRA/TSRA DEVELOPMENT IS POSSIBLE BUT THE BULK OF THE NEAR TERM
ACTIVITY LOOKS TO REMAIN TO THE NORTH OVER THE NEXT FEW HOURS.
MDB
//PREV DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEW POINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ISO SHRA/TSRA DEVELOPING ARND 19Z THROUGH 21-22Z.
* NE WINDS THRU SUNSET...WINDS VEERING SE/S OVERNIGHT.
* ADDTL SHRA/TSRA PSBL ARND DAYBREAK.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VISIBLE IMAGERY THIS AFTN WAS DEPICTING SOME BUILDING CUMULUS
CLOUDS ACROSS NORTHERN IL/NORTHWEST IN. ADDTL DEVELOPMENT WAS
NOTED FURTHER EAST. A FRONTAL BOUNDARY WAS ORIENTED FROM RFD SE
THRU JOT. WINDS NE OF THIS BNDRY WERE FROM THE NE...WHILE WINDS SW
OF THIS WERE SOUTHERLY. GUIDANCE CONTINUES TO SHOW THIS AS THE
FOCAL POINT FOR ISO SHRA/TSRA ARND 19-20Z...THEN CONTINUE THRU
22-23Z. COVERAGE SHUD REMAIN MINIMAL. WINDS WILL THEN VEER SE THIS
EVE/OVERNIGHT...WITH A SECOND AREA OF CONVECTION PSBLY EARLY THUR
MORNING. GUIDANCE HAS CONTINUED TO FOCUS THIS SECOND AREA OF
DEVELOPMENT TOWARDS THE 11-15Z TIMEFRAME...THEN PUSH THE BULK OF
THE LOW/MID LVL MOISTURE EAST...RESULTING IN DRY WEATHER FOR THE
REMAINDER OF THE AFTN THUR. WINDS WILL THEN BACK EAST AND
EVENTUALLY NORTHEAST AS A WEAK LOW PRESSURE SLIDES EAST ACROSS
NORTHERN IL/NORTHWEST IN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN TS COVERAGE AND TIMING.
* MEDIUM CONFIDENCE IN ENDING OF TS/SHRA.
* LOW CONFIDENCE IN PRECIP DEVELOPMENT OVERNIGHT INTO EARLY THUR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...
FRI THROUGH TUE...VFR. NO SIG WX.
TRS
&&
.MARINE...
432 AM CDT
A COLD FRONT TRAILS FROM LOW PRESSURE OVER THE GULF OF ST.
LAWRENCE ACROSS SOUTHERN LOWER MI...FAR SOUTHERN LAKE MI AND FAR
NORTHERN IL EARLY THIS MORNING. THE COLD FRONT WILL CONTINUE TO
MOVE SLOWLY SOUTHWARD TODAY AND TONIGHT...EXTENDING FROM CENTRAL
IN ACROSS IL TO CENTRAL IA BY THURSDAY MORNING. HIGH PRESSURE OF
WILL BUILD SE FROM HUDSON BAY AND ONTARIO BEHIND THE COLD
FRONT...SPREADING ACROSS THE GREAT LAKES TODAY AND TONIGHT. LOW
PRESSURE WILL RIDE ALONG THE FRONTAL BOUNDARY FROM IA TO THE
UPPER OH VALLEY DURING THU WHILE A RIDGE OF HIGH PRESSURE REMAINS
OVER THE GREAT LAKES. LOW PRESSURE WILL BE TRACKING E FROM CENTRAL
CANADA TO HUDSON BAY THU NIGHT THROUGH FRI NIGHT WHILE THE RIDGE
OVER THE GREAT LAKES SHIFTS S OVER THE NORTHEASTERN U.S. AND THE
MIDWEST. THE COLD FRONT TRAILING FROM THE CANADIAN LOW WILL DROP S
ACROSS NORTHERN LAKE MI SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1237 PM CDT WED JUL 18 2012
.DISCUSSION...
558 AM CDT
LATEST RADAR/SURFACE OBS SHOW FRONTAL BOUNDARY STRETCHING FROM
NEAR DUBUQUE TO MORRIS TO NEAR VALPARAISO AT 530 AM WHICH HAD
SURGED SOUTHWARD OVER THE LAST HOUR. RADAR MOSAIC SHOWS ANOTHER
BOUNDARY FROM NEAR JANESVILLE TO CHICAGO. THIS BOUNDARY IS
COINCIDENT WITH SPOTTY CONVECTION NEAR MADISON AND A FEW SMALL
CELLS OVER SOUTHERN LAKE MICHIGAN. THE MAIN AREA OF CONVECTION
REMAINS MORE CLOSELY TIED TO THE MID LEVEL BAROCLINIC ZONE RUNNING
FROM THE TWIN CITIES INTO CENTRAL LOWER MICHIGAN. HIGH RES NEAR
TERM GUIDANCE SHOWS SOME INTERESTING SOLUTIONS IN TERMS OF
WINDS/BOUNDARY PLACEMENT INTO THE AFTERNOON. THE RAP AND THE HRRR
BOTH DEPICT THE CURRENT EXPANSE OF NORTHEAST WINDS BEHIND THE
FIRST BOUNDARY BUT THEN TURN WINDS ACROSS MUCH OF THE AREA
SOUTHWESTERLY THIS MORNING WITH A BOUNDARY SETTING UP FROM NEAR
ROCKFORD TO JOLIET TO RENSSELAER OR SO. THIS IS AN INTERESTING
PROGRESSION OF THINGS IF THIS INITIAL BOUNDARY WERE THE TRUE COLD
FRONT. LOCAL WRF SHOWS A SIMILAR THOUGH LESS PRONOUNCED TREND.
ASSUMING THIS BOUNDARY IS THE COLD FRONT IT IS POSSIBLE THAT IT
DOES MOVE BACK NORTHWARD INTO THE MIDDLE OF THE DAY IN RESPONSE TO
THE UPPER TROUGH MOVING TOWARD THE MID/UPPER MISSISSIPPI RIVER
VALLEY GIVEN THAT THE WESTERN EXTENT OF THE FRONT IS IN NORTHWEST
IOWA CLOSER TO WHERE THE UPPER TROUGH AXIS IS NOW. ANOTHER
SCENARIO IS THAT THE INITIAL BOUNDARY WAS SOME SORT OF SHALLOW
OUTFLOW WHICH MIXES OUT THIS MORNING AND THE MAIN FRONT IS THE
BOUNDARY CLOSER TO THE CHICAGO AREA DESCRIBED ABOVE. LOOKING AT
THE VAD WIND PROFILES FROM LOT AND MKX THEY SHOW SIMILAR DEPTHS OF
NORTHEAST WINDS SO IT SEEMS THAT THIS IS A LESS LIKELY SCENARIO.
WILL KEEP THE FORECAST MORE OR LESS AS-IS FOR NOW. OTHERWISE...SPOTTY
SHRA/TSRA DEVELOPMENT IS POSSIBLE BUT THE BULK OF THE NEAR TERM
ACTIVITY LOOKS TO REMAIN TO THE NORTH OVER THE NEXT FEW HOURS.
MDB
//PREV DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEW POINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ISO SHRA/TSRA DEVELOPING ARND 19Z THROUGH 21-22Z.
* NE WINDS THRU SUNSET...WINDS VEERING SE/S OVERNIGHT.
* ADDTL SHRA/TSRA PSBL ARND DAYBREAK.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VISIBLE IMAGERY THIS AFTN WAS DEPICTING SOME BUILDING CUMULUS
CLOUDS ACROSS NORTHERN IL/NORTHWEST IN. ADDTL DEVELOPMENT WAS
NOTED FURTHER EAST. A FRONTAL BOUNDARY WAS ORIENTED FROM RFD SE
THRU JOT. WINDS NE OF THIS BNDRY WERE FROM THE NE...WHILE WINDS SW
OF THIS WERE SOUTHERLY. GUIDANCE CONTINUES TO SHOW THIS AS THE
FOCAL POINT FOR ISO SHRA/TSRA ARND 19-20Z...THEN CONTINUE THRU
22-23Z. COVERAGE SHUD REMAIN MINIMAL. WINDS WILL THEN VEER SE THIS
EVE/OVERNIGHT...WITH A SECOND AREA OF CONVECTION PSBLY EARLY THUR
MORNING. GUIDANCE HAS CONTINUED TO FOCUS THIS SECOND AREA OF
DEVELOPMENT TOWARDS THE 11-15Z TIMEFRAME...THEN PUSH THE BULK OF
THE LOW/MID LVL MOISTURE EAST...RESULTING IN DRY WEATHER FOR THE
REMAINDER OF THE AFTN THUR. WINDS WILL THEN BACK EAST AND
EVENTUALLY NORTHEAST AS A WEAK LOW PRESSURE SLIDES EAST ACROSS
NORTHERN IL/NORTHWEST IN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN TS COVERAGE AND TIMING.
* MEDIUM CONFIDENCE IN ENDING OF TS/SHRA.
* LOW CONFIDENCE IN PRECIP DEVELOPMENT OVERNIGHT INTO EARLY THUR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...
FRI THROUGH TUE...VFR. NO SIG WX.
TRS
&&
.MARINE...
432 AM CDT
A COLD FRONT TRAILS FROM LOW PRESSURE OVER THE GULF OF ST.
LAWRENCE ACROSS SOUTHERN LOWER MI...FAR SOUTHERN LAKE MI AND FAR
NORTHERN IL EARLY THIS MORNING. THE COLD FRONT WILL CONTINUE TO
MOVE SLOWLY SOUTHWARD TODAY AND TONIGHT...EXTENDING FROM CENTRAL
IN ACROSS IL TO CENTRAL IA BY THURSDAY MORNING. HIGH PRESSURE OF
WILL BUILD SE FROM HUDSON BAY AND ONTARIO BEHIND THE COLD
FRONT...SPREADING ACROSS THE GREAT LAKES TODAY AND TONIGHT. LOW
PRESSURE WILL RIDE ALONG THE FRONTAL BOUNDARY FROM IA TO THE
UPPER OH VALLEY DURING THU WHILE A RIDGE OF HIGH PRESSURE REMAINS
OVER THE GREAT LAKES. LOW PRESSURE WILL BE TRACKING E FROM CENTRAL
CANADA TO HUDSON BAY THU NIGHT THROUGH FRI NIGHT WHILE THE RIDGE
OVER THE GREAT LAKES SHIFTS S OVER THE NORTHEASTERN U.S. AND THE
MIDWEST. THE COLD FRONT TRAILING FROM THE CANADIAN LOW WILL DROP S
ACROSS NORTHERN LAKE MI SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1106 AM CDT WED JUL 18 2012
.DISCUSSION...
558 AM CDT
LATEST RADAR/SURFACE OBS SHOW FRONTAL BOUNDARY STRETCHING FROM
NEAR DUBUQUE TO MORRIS TO NEAR VALPARAISO AT 530 AM WHICH HAD
SURGED SOUTHWARD OVER THE LAST HOUR. RADAR MOSAIC SHOWS ANOTHER
BOUNDARY FROM NEAR JANESVILLE TO CHICAGO. THIS BOUNDARY IS
COINCIDENT WITH SPOTTY CONVECTION NEAR MADISON AND A FEW SMALL
CELLS OVER SOUTHERN LAKE MICHIGAN. THE MAIN AREA OF CONVECTION
REMAINS MORE CLOSELY TIED TO THE MID LEVEL BAROCLINIC ZONE RUNNING
FROM THE TWIN CITIES INTO CENTRAL LOWER MICHIGAN. HIGH RES NEAR
TERM GUIDANCE SHOWS SOME INTERESTING SOLUTIONS IN TERMS OF
WINDS/BOUNDARY PLACEMENT INTO THE AFTERNOON. THE RAP AND THE HRRR
BOTH DEPICT THE CURRENT EXPANSE OF NORTHEAST WINDS BEHIND THE
FIRST BOUNDARY BUT THEN TURN WINDS ACROSS MUCH OF THE AREA
SOUTHWESTERLY THIS MORNING WITH A BOUNDARY SETTING UP FROM NEAR
ROCKFORD TO JOLIET TO RENSSELAER OR SO. THIS IS AN INTERESTING
PROGRESSION OF THINGS IF THIS INITIAL BOUNDARY WERE THE TRUE COLD
FRONT. LOCAL WRF SHOWS A SIMILAR THOUGH LESS PRONOUNCED TREND.
ASSUMING THIS BOUNDARY IS THE COLD FRONT IT IS POSSIBLE THAT IT
DOES MOVE BACK NORTHWARD INTO THE MIDDLE OF THE DAY IN RESPONSE TO
THE UPPER TROUGH MOVING TOWARD THE MID/UPPER MISSISSIPPI RIVER
VALLEY GIVEN THAT THE WESTERN EXTENT OF THE FRONT IS IN NORTHWEST
IOWA CLOSER TO WHERE THE UPPER TROUGH AXIS IS NOW. ANOTHER
SCENARIO IS THAT THE INITIAL BOUNDARY WAS SOME SORT OF SHALLOW
OUTFLOW WHICH MIXES OUT THIS MORNING AND THE MAIN FRONT IS THE
BOUNDARY CLOSER TO THE CHICAGO AREA DESCRIBED ABOVE. LOOKING AT
THE VAD WIND PROFILES FROM LOT AND MKX THEY SHOW SIMILAR DEPTHS OF
NORTHEAST WINDS SO IT SEEMS THAT THIS IS A LESS LIKELY SCENARIO.
WILL KEEP THE FORECAST MORE OR LESS AS-IS FOR NOW. OTHERWISE...SPOTTY
SHRA/TSRA DEVELOPMENT IS POSSIBLE BUT THE BULK OF THE NEAR TERM
ACTIVITY LOOKS TO REMAIN TO THE NORTH OVER THE NEXT FEW HOURS.
MDB
//PREV DISCUSSION...
322 AM CDT
HEAT AND THUNDER CHANCES REMAIN THE MAIN FORECAST CHALLENGES THIS
MORNING. EARLY MORNING WATER VAPOR IMAGERY SHOWS A LARGE CLOSED
UPPER LOW OVER NORTHERN QUEBEC WITH WEAK RIDGING TO ITS WEST
EXTENDING FROM THE CENTRAL PLAINS NORTHWARD INTO NORTHERN MANITOBA.
SEVERAL SHORTWAVES ARE EMBEDDED WITH THE MORE ZONAL PORTION OF THE
RIDGING OVER THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY.
THE MOST NOTABLE IS A VORT MAX OVER SOUTH DAKOTA WHICH IS PART OF A
TROUGH AXIS EXTENDING FROM SOUTHERN ALBERTA INTO NORTHERN NEBRASKA
WHICH IS PUSHING EASTWARD. THIS WILL LIKELY AFFECT THE LOCAL
FORECAST COMING UP TONIGHT/THURSDAY MORNING. TO THE WEST A CLOSED
UPPER LOW HAS STALLED OUT OVER THE WESTERN OREGON/CALIFORNIA BORDER.
AT THE SURFACE...AN OUTFLOW BOUNDARY FROM CONVECTION TO THE NORTH
HAD PUSHED DOWN LAKE MICHIGAN AND INTO NORTHEAST ILLINOIS THIS PAST
EVENING TURNING WINDS NORTHEASTERLY. THIS BOUNDARY HAS WASHED OUT
AS EVIDENCED BY SEVERAL SITES BEHIND WHERE IT PASSED HAVING SWITCHED
AROUND TO A SOUTHWEST WIND. THE COOL FRONT IS NOW JUST NORTH OF
FREEPORT AND JUST SOUTH OF MIDWAY AND IS STILL MOVING SOUTHWARD.
THE MOVEMENT OF THIS FRONT AND THE UPPER SHORT WAVES WILL BE THE
MAIN FEATURES OF NOTE FOR THE SHORT TERM.
TODAY...THE COOL FRONTAL POSITION WILL BE ONE OF THE MAIN CHALLENGES
THROUGH THE DAY AND WILL DICTATE THE TEMP AND PRECIP FORECASTS INTO
THIS EVENING. CURRENTLY...PRECIPITATION IS ASSOCIATED WITH THE MID
LEVEL BAROCLINIC ZONE TRAILING NORTH OF THE FRONT FROM THE TWIN
CITIES ACROSS CENTRAL LAKE MICHIGAN AND ARCHING SOUTHEASTWARD ACROSS
CENTRAL LOWER MICHIGAN. ACTIVITY WILL LIKELY FESTER ALONG THIS ZONE
PERIODICALLY THROUGH THE DAY WITH A SLOW SOUTHWARD MOVEMENT OF THE
MID LEVEL TEMP GRADIENT. AT THIS POINT EXPECT THIS TO BE FOCUSED TO
THE NORTH OF THE CWA. CANNOT COMPLETELY RULE OUT ISOLATED
DEVELOPMENT NEAR THE SURFACE FRONT THIS MORNING BUT CHANCES APPEAR
SLIM. LATEST NAM AND GFS PUT THE FRONT...IN A SOMEWHAT INCOHERENT
STATE...OVER THE FAR SOUTHWESTERN CWA BY EARLY AFTERNOON. LOCAL HIGH
RES GUIDANCE IS A LITTLE SLOWER WITH THE BOUNDARY AND THUS FURTHER
NORTH WITH IT FOR THE AFTERNOON. THE LATEST SURFACE ANALYSIS
SUGGESTS THAT THERE IS A WEAK LOW CENTER OVER NORTHEAST IOWA WHICH
THE RAP ALSO DEPICTS. THE RAP SOLUTION OF THE FRONT SLOWING AND
EVEN PUSHING BACK NORTHWARD SOMEWHAT AS THIS LOW CENTER MOVES
EASTWARD IS PLAUSIBLE. DESPITE THE UNCERTAINTY WITH THE FRONTAL
POSITION THROUGH THE DAY...THE BOUNDARY WILL MOVE INTO HIGHER
DEW POINT AIR ALLOWING FOR SOME POOLING OF MOISTURE AHEAD OF IT
THIS AFTERNOON WHICH IS EXPECTED TO RESULT IN STRONG SURFACE BASED
INSTABILITY ALONG AND SOUTH OF THE FRONT. WITH SOME MIXING
EXPECTED MIXED LAYER INSTABILITY WILL BE LOWER BUT STILL
SUFFICIENT TO SUPPORT STORMS. A SHARP INSTABILITY GRADIENT IS
EXPECTED TO SET UP WITH LATEST THINKING HAVING IT RUN FROM ROUGHLY
ROCKFORD DOWN TOWARDS JOLIET AND EASTWARD TOWARDS RENSSELAER
DURING THE AFTERNOON...WITH EXACT PLACEMENT DEPENDENT ON HOW FAR
SOUTH THE FRONT MOVES. BEYOND RATHER BROAD LOW LEVEL CONVERGENCE
ALONG THE FRONT THERE IS NOT MUCH IN THE WAY OF A LARGER SCALE
TRIGGERING MECHANISM BUT CONVECTIVE TEMPERATURES IN THE MID 90S
SHOULD BE ATTAINABLE SO ISOLATED TO SCATTERED DEVELOPMENT IS
PLAUSIBLE. STORMS THAT DO FORM WILL HAVE AT LEAST SOME SEVERE WIND
POTENTIAL GIVEN THE INVERTED V SOUNDING. EXPECT THAT THE BEST
CHANCE FOR OCCURRENCE IS FROM ROUGHLY ROCKFORD TO JOLIET TO
RENSSELAER SOUTHWARD IN LINE WITH THE EXPECTED INSTABILITY
GRADIENT. HOWEVER...THIS THREAT AREA MAY PUSH SOUTHWESTWARD IF THE
FRONT CAN KEEP SOME FORWARD SPEED THOUGH LATE AFTERNOON. TEMPS ARE
THE NEXT ISSUE...AS INDICATED ABOVE HUMIDITY WILL BE HIGHER THAN
TUESDAY AHEAD OF THE FRONT THANKS TO MOISTURE POOLING. WITH HIGHS
STILL EXPECTED TO BE IN THE MID TO EVEN UPPER 90S SOUTH WILL
MAINTAIN THE HEAT ADVISORY...BUT SOME OF THE NORTHERN PORTIONS OF
IT MAY NOT REACH CRITERIA IF THE FRONT REMAINS ON THE MOVE...OF
CONCERN WOULD BE JASPER AND NEWTON COUNTIES. WILL KEEP THE
ADVISORY GOING AS IS AND LET THE DAY SHIFT MONITOR TEMPS AND TRIM
IF NEEDED. HIGHS NORTH OF THE FRONT WILL BE TRICKIER...BUT BE
RELATIVELY COOLER WITH HIGHS IN THE UPPER 80S TO AROUND
90...THOUGH A NORTHEASTERLY WIND OFF THE LAKE WILL PROBABLY KEEP
LAKESHORE AREAS IN THE MID 80S. DO SEE SOME BUST POTENTIAL ACROSS
THESE AREAS WITH SOME CONCERN THAT FORECAST HIGHS MAY BE A BIT
WARM. IT WILL STILL BE HUMID IN THESE AREAS AS WELL BUT BELOW
ADVISORY LEVELS.
TONIGHT AND THURSDAY...LARGER SCALE FORCING INCREASES TONIGHT...MOST
NOTABLY LATE...AS THE MID LEVEL BAROCLINIC ZONE CURRENTLY NORTH OF THE
AREA RE-ORIENTS FROM WEST TO EAST TO NORTHWEST TO SOUTHEAST AND
SETTLES INTO THE AREA. IN ADDITION...THE WAVE NOTED OVER SOUTH
DAKOTA AND ITS ASSOCIATED TROUGH AXIS IS EXPECTED TO REACH THE AREA
AS IT TURNS SOUTHEASTWARD WITH THE UPPER FLOW BUCKLING AS THE LARGE
QUEBEC UPPER LOW MOVES SOUTHWARD. THE WAVE WILL CROSS THE AREA LATE
TONIGHT INTO THURSDAY MORNING AND WILL A HAVE DECENT CHANCE OF
BRINGING CONVECTION ACROSS THE ENTIRE FORECAST AREA. ITS NOT CLEAR
HOW WIDESPREAD COVERAGE WILL BE HOWEVER BUT THIS CHANCE FOR PRECIP
IS DECENT. LOW CHANCES FOR SCATTERED ACTIVITY WILL BE IN PLACE THIS
EVENING ACROSS THE SOUTHWESTERN CWA WITH LITTLE SUPPORT FOR POPS
NORTHEAST DURING THAT TIME...THOUGH THE BAROCLINIC ZONE MAY BE
GENERATING SOME ACTIVITY JUST TO THE NORTHEAST. PRECIP CHANCES WIND
DOWN THURSDAY AFTERNOON...THOUGH LOW CHANCES CONTINUE SOUTH PERHAPS
THROUGH EARLY EVENING BEFORE THE UPPER FORCING EXITS TO THE
SOUTHEAST AND SURFACE HIGH PRESSURE ARRIVES FROM THE NORTH. HIGHS
THURSDAY WILL RANGE FROM THE MID 80S NORTHEAST WITH FLOW OFF THE
LAKE TO AROUND 90 SOUTHWEST...THOUGH TEMPS MAY NOT REACH THESE
LEVELS TIL LATER IN THE AFTERNOON IF PRECIP IS IN PLACE IN THE
MORNING.
FRIDAY THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BE IN PLACE
FRIDAY WITH THE MAIN UPPER TROUGH ALONG THE EAST COAST AND A BIG
RIDGE OVER THE WESTERN AND CENTRAL U.S...WITH A RIDGE AXIS EXTENDING
NORTHEAST TOWARDS HUDSON BAY AND ANOTHER AIMED NORTHWEST INTO
ALBERTA...WITH A TROUGH PASSING BETWEEN THE TWO OVER NORTHERN
MANITOBA. THIS TROUGH FLATTENS THE EASTERN RIDGE AXIS WHILE A BIG
UPPER LOW ARRIVES OVER WESTERN BRITISH COLUMBIA TO AMPLIFY THE
WESTERN AXIS...THOUGH THERE IS A WEAK TROUGH AHEAD OF IT TO
TEMPORARILY BREAK IT DOWN. THIS RESULTS IN A NORTHWESTERLY FLOW FROM
THE NORTHERN PLAINS INTO THE LOWER GREAT LAKES BY SUNDAY. THE
QUESTION IS HOW FAR SOUTH THIS ACTIVE CORRIDOR OF FLOW WILL BE
PLACED. THE GFS KEEPS THE LOCAL AREA IN THE PATH OF WEAK SHORTWAVES
WHILE THE ECMWF...WHICH IS VERY SIMILAR IN THE OVERALL
PATTERN...KEEPS THE WAVE TRAIN A LITTLE FURTHER NORTHEAST OF HERE
INTO EARLY NEXT WEEK. FRIDAY LOOKS LIKE A RELATIVELY PLEASANT DAY
WITH SURFACE HIGH PRESSURE KEEPING A NORTHEAST WIND IN PLACE AND A
CORRIDOR OF COOLER MID LEVEL AIR...H85 TEMPS AROUND 14C...IN PLACE
BEHIND THE DEPARTING UPPER TROUGH. THIS SHOULD LEAD TO HIGHS IN THE
MID TO UPPER 80S...THOUGH SOME WESTERN AREAS COULD AGAIN TOUCH 90.
SATURDAY STILL LOOKS TO BE DRY BUT THE ABOVE BECOMES MORE OF AN
ISSUE FROM SUNDAY AND BEYOND. POP CHANCES WOULD LIKELY BE LOW
ANYWAYS GIVEN THE NATURE OF THESE EMBEDDED IMPULSES SO WILL
GENERALLY KEEP THE FORECAST DRY FOR NOW. TEMPS WILL BEGIN TO WARM
AGAIN SATURDAY AND SUNDAY...WITH SOME POTENTIAL FOR A BIGGER WARM UP
EARLY NEXT WEEK WITH THE GFS AND ECMWF PAINTING LOW 20S H85 TEMPS AT
VARIOUS TIMES. OVERALL FORECAST CONFIDENCE IN PRECIP POTENTIAL IS
LOW AND LITTLE BIT HIGHER IN TERMS OF A WARMING TREND CONTINUING
INTO EARLY NEXT WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* PSBL ISOLATED SHRA/TSRA BRUSHING TERMINALS THROUGH EARLY THIS AFTN.
* NE WINDS ARND 6 TO 8 KT THROUGH DURATION OF THE DAY.
BEACHLER
//DISCUSSION...UPDATED 12Z...
OUTFLOW FROM CENTRAL WI THUNDERSTORMS MOVES S OVER SE WI AND
SOUTHERN LAKE MI DURING THE LATE EVENING WITH ANOTHER OUTFLOW
DOING THE SAME DURING THE OVERNIGHT. APPEARS THAT ACTUAL SURFACE
FRONT HAS SLIPPED ACROSS FAR NE IL AROUND SUNRISE WITH RADAR
COMPOSITE SHOWING A BOUNDARY FROM AROUND DOWNTOWN CHI WNW ACROSS
THE WI BORDER N OF RFD AND THEN NORTHWESTWARD TO S OF MSN.
THUNDERSTORMS DEVELOPED IN S CENTRAL WI DURING THE PREDAWN N OF
THE BOUNDARY WHILE ELEVATED THUNDERSTORMS HAVE CONTINUED ACROSS
CENTRAL WI ANS ESE FROM GRB ACROSS CENTRAL LAKE MI AND CENTRAL
LOWER MI.
WESTERN EXTENT OF CENTRAL WI ACTIVITY IS SHOWING A GENERAL
DOWNWARD TREND AS ONE SHORT WAVE MOVES FROM E CENTRAL WI INTO W
CENTRAL WI. FURTHER UPSTREAM...A LARGER AREA OF THUNDERSTORMS WAS
MOVING FROM EASTERN SD INTO W CENTRAL AND SE MN AS A MORE WELL
DEFINED SHORT WAVE PUSHES ENE FROM THE WESTERN DAKOTAS.
SHORTER TERM CONCERN IS PROSPECTS OF THUNDERSTORMS ALONG/NEAR THE
SURFACE FRONT ACROSS NE AND FAR N CENTRAL IL INTO S CENTRAL WI.
MODELS GENERALLY SHOW THE FRONT MAKING A LITTLE FURTHER SOUTHWARD
PROGRESS THIS MORNING TO S OF THE CHI TERMINALS. DUE TO
UNCERTAINTY IN TS TO CONTINUE TO DEVELOP IN ASSOCIATION WITH THE
FRONT HAVE INCLUDED A VCTS IN THE TAFORS FOR THIS AFTERNOON AS
PROBABILITY OF ACTUALLY OCCURRING AND TERMINAL IS LOW.
IN THE OUTER PERIOD OF THE TAFORS CONCERN IS PROSPECTS FOR TS
WITH THE NORTHERN PLAINS SHORT WAVE. THE SHORT WAVE TROUGH AXIS
IS PROGGED TO REACH W CENTRAL WI...SE MN AND EASTERN IA BY 00Z
AND TO DROP ESE ACROSS SOUTHERN WI AS WELL AND NORTHERN AND W
CENTRAL OVERNIGHT. PERSISTENT POST FRONTAL CONVECTION THE LAST
COUPLE DAYS FROM THE NORTHERN PLAINS E ACROSS THE WESTERN GREAT
LAKES HAS BEEN OCCURRING WHERE ELEVATED CAPE HAS BEEN IN PLACE.
WITH MODELS SUGGESTING THAT THIS ELEVATED CAPE WILL SHIFT S WITH
TIME FEEL THERE IS A BETTER CHANCE OF SHOWERS AND THUNDERSHOWERS
AT THE LOCAL TERMINALS DURING THE LATE NIGHT AND EARLY MORNING
HOURS OF THU THUS THE PROB30 NEAR/AROUND SUNRISE THU.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN TS COVERAGE AND TIMING.
* MEDIUM CONFIDENCE IN ENDING OF TS/SHRA.
* LOW CONFIDENCE IN PRECIP DEVELOPMENT OVERNIGHT INTO EARLY THUR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...
FRI THROUGH TUE...VFR. NO SIG WX.
TRS
&&
.MARINE...
432 AM CDT
A COLD FRONT TRAILS FROM LOW PRESSURE OVER THE GULF OF ST.
LAWRENCE ACROSS SOUTHERN LOWER MI...FAR SOUTHERN LAKE MI AND FAR
NORTHERN IL EARLY THIS MORNING. THE COLD FRONT WILL CONTINUE TO
MOVE SLOWLY SOUTHWARD TODAY AND TONIGHT...EXTENDING FROM CENTRAL
IN ACROSS IL TO CENTRAL IA BY THURSDAY MORNING. HIGH PRESSURE OF
WILL BUILD SE FROM HUDSON BAY AND ONTARIO BEHIND THE COLD
FRONT...SPREADING ACROSS THE GREAT LAKES TODAY AND TONIGHT. LOW
PRESSURE WILL RIDE ALONG THE FRONTAL BOUNDARY FROM IA TO THE
UPPER OH VALLEY DURING THU WHILE A RIDGE OF HIGH PRESSURE REMAINS
OVER THE GREAT LAKES. LOW PRESSURE WILL BE TRACKING E FROM CENTRAL
CANADA TO HUDSON BAY THU NIGHT THROUGH FRI NIGHT WHILE THE RIDGE
OVER THE GREAT LAKES SHIFTS S OVER THE NORTHEASTERN U.S. AND THE
MIDWEST. THE COLD FRONT TRAILING FROM THE CANADIAN LOW WILL DROP S
ACROSS NORTHERN LAKE MI SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
7 PM WEDNESDAY.
IN...HEAT ADVISORY...INZ010-INZ011-INZ019 UNTIL 7 PM WEDNESDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 PM CDT WED JUL 18 2012
...UPDATE TO AVIATION FOR 18Z TAFS...
.SYNOPSIS...
ISSUED AT 917 AM CDT WED JUL 18 2012
THE 18.12Z 250 HPA SYNOPTIC MAP SHOWED A 50 TO 60 KT CYCLONIC CIRCULATION
STILL ACROSS THE PACIFIC NORTHWEST AND EXTENDING SOUTHWARD ACROSS NORTHERN
CALIFORNIA. A ~100 KT JET STREAK WAS LOCATED ACROSS SOUTHEASTERN CANADA.
OTHERWISE, FLOW AT JET LEVEL WAS FAIRLY WEAK ACROSS MOST OF THE COUNTRY
AS ONE WOULD EXPECT DURING THE SUMMER. @ 500 HPA, AN ABNORMALLY STRONG
569 DM LOW WAS SPINNING ACROSS NORTHWESTERN CALIFORNIA. A COLD POOL
OF -17 DEG C WAS ASSOCIATED WITH SAID FEATURE. TWO 590 DM HIGH PRESSURE
CENTERS WERE LOCATED CLOSER TO KANSAS. ONE ACROSS THE SOUTHERN ROCKIES
AND THE OTHER ACROSS THE OZARKS. A WEAK CYCLONE WAS FOUND ACROSS GEORGIA.
AT 700/850 HPA, THE WARM/DRY PLUME WAS STILL OBVIOUS ACROSS THE PLAINS
WITH 700 HPA TEMPERATURES RUNNING IN THE 12 TO 13 DEG C RANGE AND 850
HPA TEMPERATURES IN THE 25 TO 26 DEG C RANGE. AT THE SFC, A TROUGH AXIS
WAS LOCATED ACROSS KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 226 AM CDT WED JUL 18 2012
CLOUDS INCREASING IN AREAL COVERAGE EARLY THIS MORNING NEAR A
500MB DEFORMATION ZONE/COL BASED ON 00Z ANALYSIS. ALL THE MODELS
PICK UP ON THIS FEATHER AND INCREASE 700MB RELATIVE HUMIDITY
VALUES EARLY THIS MORNING. THE HRRR EVEN SUGGESTS SOME LIGHT
PRECIPITATION WILL BE POSSIBLE. BASED ON LATEST RADAR TRENDS WILL
FOLLOW THE HRRR AND INTRODUCE SOME LIGHT PRECIPITATION EARLY THIS
MORNING IN SOUTH CENTRAL KANSAS.
AN UPPER LEVEL RIDGE WILL THEN BUILD ACROSS THE CENTRAL AND
NORTHERN ROCKIES LATER TODAY AS THE CENTER OF THIS HIGH, LOCATED
OVER COLORADO, MOVES VERY LITTLE. MODELS REMAIN IN GOOD AGREEMENT
IN MOVING A SURFACE BOUNDARY ACROSS WESTERN KANSAS DURING THE EARLY
MORNING HOURS AND BY THE EARLY AFTERNOON THIS BOUNDARY IS EXPECTED
TO EXTEND FROM HAYS TO GARDEN CITY TO NEAR ELKHART. FORECAST MODEL
SOUNDINGS NEAR THIS SURFACE TROUGH INDICATED SOME MID LEVEL
INSTABILITY AND MOISTURE IN THE 700-600MB LEVEL WILL BE PRESENT AS
AN UPPER LEVEL DISTURBANCE ROTATES AROUND THE UPPER HIGH AND
CROSSES INTO WESTERN KANSAS. GIVEN THE ESTIMATED TIMING OF THIS
UPPER LEVEL DISTURBANCE ALONG WITH WHERE THE BETTER THE LATE DAY
INSTABILITY IS EXPECTED WILL INCREASE THE PRECIPITATION CHANCES
NEAR THE SURFACE BOUNDARY LATE THIS AFTERNOON...ESPECIALLY IN
NORTH CENTRAL KANSAS. THE INVERTED V TYPE OF SOUNDINGS CONTINUE TO
SUGGEST THE PREVIOUS SHIFT HAD THE RIGHT IDEA WITH THE PRIMARY
HAZARD BEING WINDS GUSTY UP TO 45 MPH AND CLOUD TO GROUND
LIGHTNING.
CLOUD COVER THIS AFTERNOON WILL PLAY AN IMPORTANT ROLE ON
TEMPERATURES TODAY. MIXING DOWN THE NAM AND ECMWF 850MB
TEMPERATURES AT 00Z THURSDAY SUGGESTS HIGHS WILL BE MAINLY IN THE
100 TO 104 DEGREE RANGE. INCREASING AFTERNOON CLOUDS AHEAD OF THE
UPPER LEVEL DISTURBANCE HOWEVER MAY RESULT IN KEEPING TEMPERATURES
SEVERAL DEGREES COOLER THAN THIS. AT THIS TIME THERE STILL APPEARS
TO BE A DECENT AMOUNT OF AFTERNOON SUNSHINE SO WILL CONTINUE TO
TREND TOWARDS THE WARMER NAM/ECMWF SOLUTION WHICH HAPPENS TO BE
VERY SIMILAR TO THE PREVIOUS FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 337 AM CDT WED JUL 18 2012
THE GENERAL UPPER-LEVEL PATTERN THROUGH JULY 25TH WILL FEATURE
UPPER-LEVEL RIDGING OVER KANSAS AND UPPER-LEVEL SHORTWAVE TROUGHS
POSITIONED FAR TO THE NORTH AND WEST OF KANSAS ACROSS THE NORTHERN
ROCKIES AND SOUTHERN CANADA. HOT WEATHER WILL PERSIST THROUGHOUT THIS
PERIOD. 500MB HEIGHTS ARE PROGGED TO RISE THIS WEEK FROM 589 TO
596 DM AND THIS IMPLIES LOW TO MID-LEVEL WARMING GIVEN THAT SEA
LEVEL PRESSURE VALUES ARE EXPECTED TO CHANGE VERY LITTLE. SO HIGHS
SHOULD BE WELL OVER 100 FOR MOST OF SOUTHWEST KANSAS, EXCEPT
CLOSER TO 100 NEAR THE COLORADO BORDER. SOME READINGS NEAR
107-109F ARE POSSIBLE BY MONDAY AND TUESDAY.
THE SLOW MOVING FRONTAL BOUNDARY MENTIONED IN THE SHORT TERM DISCUSSION
THAT IS CURRENTLY OVER NORTHWEST KANSAS WILL STALL OUT IN THE MIDDLE
OF THE UPPER-LEVEL RIDGE AXIS SOMEWHERE OVER SOUTHWEST KANSAS ON
THURSDAY. THEREFORE, THERE IS A SMALL CHANCE FOR THUNDERSTORMS
WHEREVER THIS BOUNDARY STALLS OUT AND THIS IS HARD TO PINPOINT AT
THIS TIME. SO SMALL CHANCES FOR STORMS WERE INTRODUCED FOR MUCH OF
THE FORECAST AREA. EVEN THOUGH THE LOW-LEVEL MOISTURE IS MIXING
OUT IN THE HOT PLUME AS IT TRIES TO MOVE NORTHWARD INTO THE
PLAINS, SOME SURFACE BASED CAPE BETWEEN 400 AND 800 J/KG, ALONG
WITH MODEST LOW-LEVEL CONVERGENCE AND STRONG SURFACE HEATING MAY
BE ENOUGH TO INITIATE A FEW HIGH BASED THUNDERSTORMS. GIVEN THE
LOW CAPE VALUES, VERY LOW VERTICAL WIND SHEAR AND HIGH CLOUD
BASES, THE MAIN THREAT WITH THESE STORMS IS GUSTY WINDS AS HIGH AS
50 MPH AS WELL AS ANY CLOUD TO GROUND LIGHTNING.
AFTER THURSDAY, THERE IS LITTLE IN THE WAY OF HOPE FOR THUNDERSTORMS
THROUGH JULY 25TH GIVEN THE AFOREMENTIONED STRONG UPPER-LEVEL
RIDGING AND ABSENCE OF FRONTS. HOWEVER, THE LONGER RANGE MODELS
ARE OFTEN UNABLE TO RESOLVE SMALLER SCALE BOUNDARIES THAT COULD
SERVE TO INITIATE ISOLATED THUNDERSTORMS. BUT IT IS PROBABLY SAFE
TO SAY THAT WIDESPREAD BENEFICIAL RAINS ARE HIGHLY UNLIKELY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1200 PM CDT WED JUL 18 2012
A SURFACE TROUGH AXIS BISECTING THE REGION WILL ULTIMATELY LEAD TO
LIGHT AND VARIABLE WINDS TODAY. 5 TO 10 KT SOUTHERLY WINDS EXPECTED
THIS EVENING AS THE TROUGH AXIS REFORMS FARTHER WEST. OTHERWISE, VFR
CIGS EXPECTED TODAY. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON
BUT DON`T THINK ANY REDUCTION IN CIGS WILL RESULT. SINCE THE ACTIVITY
WILL BE VERY ISOLATED...WILL LEAVE TS/CB GROUPS OUT FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 72 103 74 / 10 20 20 20
GCK 100 69 101 73 / 20 20 20 10
EHA 98 70 100 72 / 10 20 0 0
LBL 101 69 101 73 / 10 20 10 0
HYS 104 73 106 76 / 20 20 20 20
P28 104 73 105 77 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
307 PM CDT WED JUL 18 2012
.DISCUSSION...
OVERALL THE LARGE SCALE PATTERN WILL CHANGE LITTLE FOR US OVER
THROUGH THE FORECAST PERIOD... WITH THE BROAD UPPER RIDGE
CONTINUING TO REIGN OVER THE CENTER OF THE CONTINENT. WE WILL
CONTINUE TO SEE ABOVE NORMAL TEMPERATURES AS A RESULT... WITH
CHANCES FOR PCPN AND SLIGHT COOL DOWNS TIED TO SHORTWAVES MOVING
THEIR WAY AROUND THE PERIPHERY OF THE UPPER RIDGE. THE GFS AND
ECMWF ARE IN REMARKABLY GOOD AGREEMENT THROUGH EARLY NEXT WEEK...
SO ALTHOUGH THEY MAY BE WRONG IT IS TOUGH TO DEVIATE TOO FAR FROM
WHAT THEY ARE SHOWING WITH RESPECT TO THE BIG PICTURE. WILL STICK
CLOSER TO THE ECMWF FOR SOME OF THE DETAILS... MAINLY DUE TO THE
LOW LEVEL COOL/WET BIASES IN THE GFS AND WHAT APPEARS TO BE AN
ASSOCIATED WET BIAS. IN THE SHORTER TERM... UTILIZED THE NAM AND
SREF FOR POP/WEATHER CHANCES AND A CONSENSUS APPROACH FOR
TEMPERATURES... BLENDING WITH POTENTIAL MIX-DOWN VALUES FOR HIGHS.
AN ELONGATED SHORTWAVE TROUGH CURRENTLY APPARENT ON WATER VAPOR
IMAGERY AND RAP UPPER LEVEL PV ANALYSES EXTENDS FROM SOUTHERN
MANITOBA INTO EASTERN NEBRASKA. A LOWER LEVEL MCV FEATURE CAN ALSO
BE SEEN MOVING EAST INTO SOUTH CENTRAL MINNESOTA. THE LATTER
FEATURE IS WORKING TO SUPPORT THE CONVECTIVE ACTIVITY CURRENTLY
OVER THE SOUTHERN PART OF THE AREA... WITH AN OUTFLOW BOUNDARY
FROM THIS MORNING/S CONVECTION ASSISTING WITH THINGS OVER
SOUTHEAST MINNESOTA. THE LARGER SCALE FRONT/BAROCLINIC ZONE IS
NEAR THE MINNESOTA/IOWA BORDER... AND SHOULD HELP TO FURTHER FOCUS
ACTIVITY AS WE HEAD INTO THE EVENING AND THE AFOREMENTIONED LARGE
SCALE SHORTWAVE TROUGH WORKS THROUGH THE AREA. MLCAPE VALUES AOA
2000 J/KG ARE PRESENT ACROSS MOST OF THE AREA... SO THERE IS NO
SHORTAGE OF INSTABILITY. WITH SOME FORCING WORKING ACROSS THE AREA
THROUGH THE EVENING HOURS... THINK WE SHOULD CONTINUE TO SEE SOME
SHRA/TSRA UNTIL WE SEE MORE SUBSTANTIAL MID-LEVEL DRYING AND
SUBSIDENCE LATER TONIGHT. ISOLATED SEVERE STORMS ARE STILL
POSSIBLE GIVEN THE DEGREE OF INSTABILITY... BUT WITH THE DEEP
LAYER SHEAR GENERALLY AOB 30 KT... THE POTENTIAL FOR WIDESPREAD
SEVERE WEATHER APPEARS TO BE LIMITED GIVEN LACK OF EXPECTED
ORGANIZATION WITH MOST STORMS. HOWEVER... A FEW STORMS COULD TAKE
ADVANTAGE OF LOCALLY ENHANCED SHEAR OWING TO THEIR STORM MOTION...
SUCH AS SOME OF THE ACTIVITY CURRENTLY OVER SOUTHEAST MINNESOTA...
AND THOSE WOULD BE THE STORMS MOST LIKELY TO GENERATE SEVERE WEATHER.
SURFACE RIDGING AND MID-LEVEL DRYING/SUBSIDENCE WILL BUILD EAST
ACROSS THE CWFA OVERNIGHT... BRINGING ANY LINGERING SHRA/TSRA TO
AN END. THE NEXT CHANCE FOR PCPN THEN LOOKS TO HOLD OFF UNTIL
FRIDAY NIGHT AND SATURDAY AS THE BAROCLINIC ZONE LIFTS BACK NORTH
ACROSS THE AREA. AT THIS POINT... THE BEST CHANCE LOOKS LIKE IT
WILL BE NORTH OF OUR CWFA CLOSER TO THE WARM FRONTAL BOUNDARY...
BUT THERE IS SUFFICIENT UNCERTAINTY IN THE BOUNDARY PLACEMENT TO
INCLUDE A CHANCE FOR SHRA/TSRA OVER THE NORTHERN HALF OR SO OF THE
AREA. THESE CHANCES WILL THEN SAG SOUTH AND EAST SATURDAY NIGHT
INTO SUNDAY AS A WAVE TRAVELS EAST ALONG THE NEARLY STATIONARY WARM
FRONTAL BOUNDARY. WILL INCLUDE SOME CHANCES FOR PCPN FROM MONDAY
NIGHT INTO WEDNESDAY AS WELL... AFTER DRYING THINGS OUT LATE
SUNDAY AND SUNDAY NIGHT... WITH THE ECMWF AND GFS BOTH SUGGESTING
WE WILL BE NEAR THE BAROCLINIC ZONE/RING OF FIRE AROUND THE
PERIPHERY OF THE UPPER RIDGE AS A FEW SHORTWAVES DROP EAST-
SOUTHEAST FROM WESTERN AND CENTRAL CANADA.
&&
.AVIATION.../18Z TAF ISSUANCE/
/ISSUED 152 PM CDT WED JUL 18 2012/
ONE CLUSTER OF THUNDERSTORMS CURRENTLY IN SW MN HEADING TO THE
NORTHEAST COULD CAUSE SOME ISSUES THIS AFTERNOON. THUNDERSTORM
COVERAGE SHOULD LARGELY BE CONFINED TO FAR SOUTHERN MN AND
WESTERN WI BY THIS EVENING. FAIRLY HIGH CONFIDENCE IN A DRY
FORECAST FOR TONIGHT. LINGERING MVFR/IFR STRATUS THIS AFTERNOON
SHOULD EXPAND TONIGHT.
KMSP...MAY HAVE TO UPDATE AT SOME POINT TO HIGHLIGHT THE THUNDER
CHANCES THIS AFTERNOON. WHILE MOST OF THE THUNDERSTORM ACTIVITY
WILL REMAIN SOUTH OF THE AIRPORT. THUNDER IS CERTAINLY A
POSSIBILITY AROUND 22Z. WINDS REMAINING OUT OF THE EAST/NORTHEAST
AND BECOMING LIGHTER NEAR SUNSET.
OUTLOOK...
THU NIGHT/FRI...VFR.
SAT...VFR BUT INCREASING HIGH CLOUDS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
152 PM CDT WED JUL 18 2012
.UPDATE...
UPDATED FOR THE 18Z AVIATION DISCUSSION BELOW.
.DISCUSSION...
SFC-925MB FRONT DOWN ALONG THE IOWA BORDER THIS MORNING...BUT H85
FRONT BISECTS THE THE MPX CWA FROM THE MADISON AREA OVER TO CHIP
FALLS/EAU CLAIRE. HAVE BEEN SEEING VERY WEAK THETA-E ADVECTION
NORTH OF THIS BOUNDARY AND THAT COMBINED WITH PWATS UP AROUND 2
INCHES AND MUCAPE AROUND 1500 J/KG HAS ALLOWED FOR SCATTERED
CONVECTION NORTH OF THIS H85 BOUNDARY FROM NE SODAK OVER TO GREEN
BAY. THIS WAA REGIME IS IN RESPONSE TO A SHORTWAVE THAT CAN
ACTUALLY BE SEEN ON A RADAR MOSAIC...WITH A NICE SPIN IN THE
REFLECTIVITY DOWN AROUND YANKTON...SD. THE RAP HAS ALSO BEEN
SHOWING A NICE PV ANOMALY ACROSS ERN SODAK THAT HAS HELPED
GENERATE MORE WIDESPREAD CONVECTION THERE. AS WE GO THROUGH THE
DAY...BOUTS OF SCT CONVECTION WILL CONTINUE TO OCCUR THROUGH THE
MORNING WITHIN THE WEAK CORRIDOR OF H85 THETA-E ADVECTION FROM
MAINLY CENTRAL MN INTO CENTRAL WI. THE 18.05 HRRR REFLECTIVITY
FORECAST PROBABLY HAS THE RIGHT IDEA FOR THIS MORNING...JUST
DISPLACED A LITTLE TOO FAR NORTH. AS THE AFTERNOON ROLLS
AROUND...THE PV ANOMALY WILL BEGIN WORKING ACROSS THE SRN HALF OF
THE MPX AREA. HAVE MAINLY 40 TO 50 POPS WORKING ACROSS THE AREA
FROM WRN MN INTO WRN WI THOUGH TONIGHT AS THIS PV FEATURE MOVES
ACROSS. MAY NEED TO BUMP UP POPS MORE AS THIS UPPER FEATURE HAS
HAD LITTLE TROUBLE FORCING CONVECTION OVERNIGHT. AS FOR SVR
POTENTIAL WITH THIS ACTIVITY...LACK OF SHEAR COMBINED WITH
FREEZING LEVELS OVER 14K FEET WILL KEEP THE SVR POTENTIAL PRETTY
MINIMAL WITH THE MAIN THREAT BEING FROM GUSTS WINDS IF WE CAN GET
ROBUST ENOUGH STORMS TO RAPIDLY COLLAPSE.
BESIDE RECEIVING SOME MUCH NEEDED RAIN...THIS WAVE WILL ALSO
PROVIDE CLOUD COVER AND COOLER TEMPS ACROSS MOST OF THE CWA FOR
TODAY. THE ONLY EXCEPTION WILL BE ACROSS SRN MN. +28C 925MB TEMPS
WILL NOT BE TOO FAR AWAY FROM THE I-90 CORRIDOR...AND IF THEY DO
NOT SEE MUCH IN THE WAY OF CLOUD COVER BY THE AFTERNOON...THEN
WILL BE ANOTHER LOWER TO MIDDLE 90S DAY DOWN THERE. DEPENDING ON
CLOUD COVER DURATION...MAY HAVE SOME AREAS STAY IN THE 70S FOR
HIGHS TODAY...ESPECIALLY IN THE NORTHEAST SECTION OF THE
CWA...WHERE TEMPS THROUGH H85 WILL BE A BIT COOLER TO BEGIN WITH.
THESE COOLER TEMPS WILL CONTINUE INTO THURSDAY...FOR WRN WI AT
LEAST...AS STRONG NW FLOW SETS IN ALOFT BEHIND TODAYS SHORTWAVE.
FOR FRIDAY THROUGH TUESDAY...THE BIG PLAYER HERE WILL BE THE
STRONG UPPER RIDGE WE HAVE SEEN ALL SUMMER WAFFLING ACROSS THE
CONUS. BY THURSDAY...ANOTHER 595+DM H5 HIGH WILL BE BUILDING
ACROSS THE HIGH PLAINS WITH THE HEAT BUBBLE WE BEAT BACK SOME
TODAY RAPIDLY REBUILDING TO THE WEST. THIS H5 RIDGE WILL SLOWLY
SHIFT INTO THE CENTRAL PLAINS FROM THE WEEKEND INTO EARLY NEXT
WEEK. UP HERE...THE MPX CWA LOOKS TO BE SITTING NEAR THE NRN
PERIPHERY OF THE RIDGE. THE WARMEST DAYS OF THIS PERIOD LOOK TO BE
FRIDAY/SATURDAY AS THE NAM/ECMWF SHOW 594DM H5 HEIGHTS BUILDING UP
INTO CENTRAL MN INTO WRN WI. THE NAM IN PARTICULAR IS RATHER
AGGRESSIVE WITH WAA INTO THE AREA THESE DAYS...WITH ITS 925-850MB
TEMPS INDICATING ANOTHER ROUND OF UPPER 90S TO 102/3 TYPE HIGHS
BEING POSSIBLE BOTH DAYS. DID BUMP HIGHS UP SOME...ESPECIALLY FOR
FRIDAY...BUT MOST MODELS SHOW A NOCTURNAL CONVECTIVE SYSTEM FIRING
OFF TO THE NORTH FRI NIGHT...THAT MAY TRY TO LAY DOWN INTO NRN
SECTIONS OF THE MPX CWA SATURDAY. GIVEN THE UNCERTAINTIES WITH
CLOUD COVER FOR SATURDAY...WAS A BIT MORE CONSERVATIVE WITH HIGHS
THEN. DUE TO PROXIMITY TO UPPER RIDGE...THE MPX AREA WILL BE PRONE
TO ANY RING OF FIRE CONVECTION SATURDAY THROUGH MONDAY. BY
TUESDAY...BOTH THE ECMWF AND GFS CONTINUE TO SHOW A STRONGER COLD
FRONT SWEEPING ACROSS THE AREA...WHICH AT THIS POINT REPRESENTS
THE BEST CHANCES FOR RAIN AFTER TODAY. THIS FRONT ALSO LOOKS TO
PROVIDE ANOTHER 2 OR 3 DAY REPRIEVE FROM THE HEAT AS WELL.
&&
.AVIATION.../18Z TAF ISSUANCE/
ONE CLUSTER OF THUNDERSTORMS CURRENTLY IN SW MN HEADING TO THE
NORTHEAST COULD CAUSE SOME ISSUES THIS AFTERNOON. THUNDERSTORM
COVERAGE SHOULD LARGELY BE CONFINED TO FAR SOUTHERN MN AND
WESTERN WI BY THIS EVENING. FAIRLY HIGH CONFIDENCE IN A DRY
FORECAST FOR TONIGHT. LINGERING MVFR/IFR STRATUS THIS AFTERNOON
SHOULD EXPAND TONIGHT.
KMSP...MAY HAVE TO UPDATE AT SOME POINT TO HIGHLIGHT THE THUNDER
CHANCES THIS AFTERNOON. WHILE MOST OF THE THUNDERSTORM ACTIVITY
WILL REMAIN SOUTH OF THE AIRPORT. THUNDER IS CERTAINLY A
POSSIBILITY AROUND 22Z. WINDS REMAINING OUT OF THE EAST/NORTHEAST
AND BECOMING LIGHTER NEAR SUNSET.
OUTLOOK...
THU NIGHT/FRI...VFR.
SAT...VFR BUT INCREASING HIGH CLOUDS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/CLF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
407 PM CDT WED JUL 18 2012
.SHORT TERM...TODAY THROUGH THURSDAY. WILL KEEP THE VERY SLIGHT
CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGH EARLY
EVENING. THIS IS ONLY A 20 PERCENT CHANCE OF PRECIPITATION. VERY HOT
WEATHER WILL CONTINUE THROUGHOUT THE PERIOD.
VISIBLE SATELLITE IMAGERY DEPICTS AN EXPANDING CU FIELD WITH
DEVELOPING THUNDERSTORMS ACROSS WESTERN NEBRASKA. MOST OF THESE
STORMS WILL DIE PRIOR TO MAKING IT INTO OR CWA. HOWEVER...THERE IS A
SLIGHT CHANCE THAT A FEW OF THESE THUNDERSTORMS MIGHT MAKE IT AS
FAR EAST AS OUR FAR WESTERN ZONES BEFORE DIEING OUT. IT IS HARD TO
PICK OUT BOUNDARIES ON THE SFC MAP WITH THE SFC WINDS BEING VERY
LIGHT AND VARIABLE ACROSS MOST OF OUR CWA. THERE IS A SLIGHTLY
MORE DEFINED SFC BOUNDARY OVER NORTH CENTRAL KANSAS WITH SOUTH
SOUTHWEST WINDS SOUTH OF THE FRONT AND NORTHEAST WINDS NORTH OF
THE FRONT. THE HRRR AND 4KM WRF CONTINUE TO HINT AT THE
POSSIBILITY OF A FEW ISOLATED THUNDERSTORMS OVER OUR CWA EARLY
THIS AFTERNOON. WE HAVE BEEN SEEING A FEW OFF AND ON SHOWERS
ACROSS THE AREA THIS AFTERNOON AND BELIEVE THIS COULD CONTINUE
UNTIL WE LOSE DIURNAL HEATING LATER THIS EVENING.
THE UPPER RIDGE WILL CONTINUE TO BUILD ON THURSDAY AND THIS SHOULD
SHUT DOWN ALL PRECIPITATION CHANCES FOR AWHILE. THEREFORE...EXPECT
DRY CONDITIONS ON THURSDAY AND IT WILL CONTINUE TO BE VERY HOT.
HEAT INDEX VALUES ARE NOT HIGH ENOUGH YET TO PUT NORTHERN ZONES IN
THE HEAT ADVISORY...BUT SOUTHERN ZONES SHOULD ONCE AGAIN SEE
TEMPERATURES/HEAT INDEX VALUES OF 100 TO 105 DEGREES.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE HOT TEMPERATURES AND A CHANCE FOR SOME
THUNDERSTORMS ON WEDNESDAY.
THE UPPER LEVEL RIDGE THAT HAS BEEN THE MAINSTAY ACROSS THE PLAINS
FOR SEVERAL DAYS WILL CONTINUE TO PLAGUE THE FORECAST AREA THROUGH
TUESDAY. TEMPERATURES WILL TOP OUT AROUND 10 DEGREES ABOVE NORMAL.
IN ADDITION TO THE HEAT THE HUMIDITY WILL ALSO CAUSE HEAT INDEX
VALUES TO RISE TO 100 TO 105 FOR NORTH CENTRAL KANSAS AND FAR
SOUTHERN NEBRASKA FOR SATURDAY INTO SUNDAY. THE HEAT CONTINUES
ACROSS THE ENTIRE AREA FOR MONDAY AND TUESDAY...WITH HIGH
TEMPERATURES ACROSS THE AREA EXPECTED TO BE AT OR ABOVE 100 DEGREES.
THERE IS A POTENTIAL FOR A BREAK IN THE HEAT MID WEEK NEXT WEEK. THE
UPPER LEVEL RIDGE FINALLY BREAKS DOWN AS AN UPPER LEVEL WAVE MOVES
THROUGH THE NORTHERN PLAINS. MODELS STILL HAVE SOME DIFFERENCES IN
TIMING AND LOCATION OF THE UPPER WAVE AND THE SURFACE FRONT THAT IS
EXPECTED TO MOVE THROUGH THE AREA. THE GFS IS A LITTLE SLOWER WITH
THE SURFACE FRONT AND A LITTLE FURTHER SOUTH WITH THE UPPER WAVE
THAN THE ECMWF. WILL GO MORE WITH THE SLOWER SOLUTION SINCE THAT IS
TYPICAL OF THE MODELS TO MOVE THINGS THROUGH TOO QUICKLY. WILL HAVE
A CHANCE FOR SOME THUNDERSTORMS IN THE WEST FOR WEDNESDAY AND
TEMPERATURES SHOULD BE A BIT COOLER WITH READINGS ONLY IN THE 90S.
&&
.AVIATION...18Z KGRI TAF. A WEAK SFC FRONTAL BOUNDARY HAS STALLED
ACROSS SOUTH CENTRAL NEBRASKA...AND THE BOUNDARY MAY TRIGGER A FEW
SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON. HOWEVER...THIS
ACTIVITY IS EXPECTED TO BE ISOLATED AND HAS NOT BEEN INCLUDED FOR
THE TERMINAL DUE TO THE LIMITED COVERAGE. WITH THE MEANDERING
BOUNDARY RIGHT OVERHEAD...WINDS WILL BE LIGHT AND VARIABLE THROUGH
TONIGHT. THE WIND WILL BECOME MORE EASTERLY TOMORROW. CLEAR TO
SCATTERED CLOUD COVER IS EXPECTED WITH A CONTINUATION OF VFR
CONDITIONS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR NEZ082>087.
KS...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR KSZ005>007-017>019.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1227 PM CDT WED JUL 18 2012
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
LATEST RADAR IMAGERY SHOWS SCATTERED SHRA/TSRA DEVELOPING ACROSS
MUCH OF THE CWA. MORNING HRRR RUNS SHOW CONTINUED AND FAIRLY
WIDESPREAD CONVECTION THROUGH THE AFTERNOON/EARLY EVENING...AND
WILL MENTION VCTS AT ALL AIRPORTS WITH TEMPO TSRA AT CSV.
AMENDMENTS TO TAFS WILL BE POSSIBLE IF DIRECT TS IMPACTS APPEAR
MORE LIKELY AT CKV/BNA. CONVECTION EXPECTED TO GENERALLY DISSIPATE
AFTER 02Z WITH GRADUAL CLEARING AFTERWARDS...BUT ISOLATED
ACTIVITY MAY CONTINUE THROUGH THE NIGHT AS AIRMASS WILL REMAIN
HIGHLY MOIST/UNSTABLE. PATCHY FOG WITH MVFR/IFR VIS EXPECTED AT
CSV OVERNIGHT. LIGHT WEST TO SOUTHWEST WINDS ANTICIPATED THROUGH
THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1002 AM CDT WED JUL 18 2012/
UPDATE...
DOING A QUICK MORNING UPDATE TO ADJUST HIGH TEMPS GIVEN THAT
MORNING TEMPS ARE OFF TO A HIGHER START THAN GRIDS REFLECTED.
HOWEVER AFTERNOON SCATTERED CONVECTION AND INCREASED CLOUD COVER
WILL HAVE SOME AFFECT ON TEMPS SO ONLY BUMPED UP A DEGREE OR TWO.
OTHERWISE HAVE SLIGHT CHC WORDING THROUGH THE MORNING WITH SCT
CONVECTION THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 542 AM CDT WED JUL 18 2012/
AVIATION 12Z DISCUSSION...
WEAK UPPER TROUGHING ACROSS THE SOUTHEASTERN U.S. WILL COMBINE
WITH HUMID CONDITIONS TO WARRANT A CONTINUATION OF ISOL TO SCT
CONVECTION THROUGH THE TAF PD. OTW...CIGS BELOW 3KFT NOT EXPECTED.
VSBYS WILL REDUCE DOWN TO THE 3-5SM LEVEL GENERALLY AFT 07Z.
DISCUSSION... UPPER HIGHS CONTINUE TO SLOWLY BREAKDOWN AS WEAK
TROUGH AXIS/ IMPULSE PASS NORTH. THIS HAS ALLOWED DEEPER MOISTURE
ADVECTION TO CONTINUE ALTHOUGH CURRENTLY LOW-LEVEL MOISTURE
MODEST. WEAK SHEAR JUST EAST HELPING TO FIRE ISO STORMS VERY NEAR
THE PLATEAU.
MOISTURE WILL CONTINUE TO DEEPEN SOME TODAY AHEAD OF GOOD IMPULSE/
VERY WEAK TROUGH WORKING DOWN TOWARD 00Z. WEAK CAP CURRENTLY EXISTS
BUT WILL LIKELY BREAK PER-18Z. BY THEN...THERMODYNAMIC PARAMETERS
WELL RAMPED UP THUS EXPECT SCT CONVECTION TO START FAIRLY EARLY
TODAY.
CENTER OF ML/UL HIGHS RETROGRADE BACK INTO THE PLAINS TONIGHT AND
HOLD THERE INTO LATER FRIDAY. THIS WILL ALLOW INITIAL WEAK TROUGHS
TO SETTLE OVER THE EASTERN US TONIGHT...BECOMING SHARPER THURSDAY
THROUGH MUCH OF FRIDAY. AMPLE MOISTURE/ENHANCED VERTICAL MOTION
AND PRESENCE OF FRONTAL BOUNDARY BY EARLY FRIDAY SETTING THE AREA
UP FOR PRETTY ACTIVE WX TO END THE WORK WEEK. STEEPENED LAPSE
RATE/STRONGER INSTABILITY ALSO LIKELY TO PRODUCE ISO STRONG-
SEVERE STORMS...ESPECIALLY THURSDAY/THURSDAY NIGHT AS FRONTAL
BOUNDARY DROPS INTO THE TN VALLEY.
FRIDAY NIGHT ML/UL TROUGH PUSHES JUST EAST...SETTING FRONTAL
BOUNDARY/DEEP MOISTURE JUST SOUTH. UPPER RIDGE AXIS AT THIS POINT
SETTLES OVER THE OH VALLEY. THIS WILL BRING A DRY WEEKEND FOR MOST
ACROSS THE MID-STATE BUT THE AREA RETURNS TO A MORE DIURNAL STORM
PATTERN EARLY-MID NEXT WEEK AS MOISTURE CREEPS BACK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
318 PM CDT WED JUL 18 2012
.SHORT TERM...
AGAIN...CONSIDERABLE QUESTIONS REMAIN AS TO WHETHER OR NOT
CONVECTION WILL BE ABLE TO DEVELOP ACROSS THE FORECAST AREA OR NOT.
UPPER LOW CONTINUES TO SPIN JUST SOUTHEAST OF THE BIG BEND OVER THE
RIO GRANDE AND THERE REMAINS SOME ENHANCED MOISTURE OVER THE REGION.
MODELS REMAIN ALL OVER THE PLACE WITH TIMING...COVERAGE...AND HOW
LONG STORMS MAY STAY AROUND /IF/ THEY DEVELOP. HRRR HAS BEEN FAIRLY
CONSISTENT WITH DEVELOPING ISOLATED TO SCATTERED STORMS ALONG AND
EAST OF THE CAPROCK WHILE THE NAM AND TTU WRF ARE DRY. CU FIELD ON
VISIBLE SATELLITE IS A BIT MORE EXTENSIVE THAN THIS TIME YESTERDAY
BUT TAKING A LOOK OUTSIDE SHOWS LITTLE VERTICAL EXTENT FOR NOW.
RADAR IS SHOWING SOME RETURNS ACROSS THE SOUTHWESTERN TEXAS
PANHANDLE INTO EASTERN NEW MEXICO BUT EVEN THESE ARE DISSIPATING
FAIRLY FAST. WILL KEEP THE FORECAST DRY FOR TONIGHT BUT WILL NEED
TO WATCH THROUGH THE LATE AFTERNOON INTO THE EVENING. TEMPERATURES
WILL BE FAIRLY SIMILAR TO TODAY AND THIS MORNING FOR HIGHS AND LOWS
TOMORROW RESPECTIVELY.
JORDAN
&&
.LONG TERM...
UA RIDGE ACROSS COLORADO WILL AMPLIFY AND SHIFT NE TO ACROSS THE
CENTRAL PLAINS ON FRIDAY...AND PERSIST THERE THROUGH THE WEEKEND.
THE MONSOONAL MOISTURE WILL GET NUDGED WEST TO CENTRAL/WESTERN NEW
MEXICO. LARGE SCALE SUBSIDENCE WILL MITIGATE STORM POTENTIAL AND
SLOWLY INCREASING THICKNESS VALUES WILL PROMOTE WARMING TEMPS /UPPER
90S ON THE CAPROCK TO LOWER TRIPLE DIGITS OFF THE CAPROCK/. WILL
NEED TO KEEP AN EYE ON A WEAKNESS/UA IMPULSE ROUNDING THE SOUTHERN
PERIPHERY OF THE SAID RIDGE...AND MOVING ACROSS THE SOUTHERN
PLAINS FRIDAY EVENING/NIGHT. THUS FAR...FORECAST MODELS ARE VOID
OF PRECIP GIVEN A MID LEVEL CAPPING INVERSION AND THIS IMPULSE
APPEARING RELATIVELY WEAK. EARLY NEXT WEEK...BOTH THE GFS AND
ECMWF HINT AT A PACIFIC UA LOW PROPAGATING ENE ACROSS NORTHERN
IDAHO/SOUTHERN ALBERTA. THIS WILL ENCOURAGE THE CENTER OF THE UA
RIDGE TO TRANSLATE SE TO THE SERN CONUS...WHERE IT IS PROGGED TO
REMAIN THROUGH MID-WEEK. AS A RESULT...THE MONSOONAL MOISTURE
PLUME MAY HAVE THE OPPORTUNITY TO NEAR THE WESTERN ZONES.
CONCURRENTLY...AN EASTERLY WAVE IS SHOWN TO MOVE ACROSS THE THE FA
TUESDAY. THE GFS AND ECMWF SOLUTIONS EXHIBIT RATHER LIGHT QPF JUST
EAST AND SE OF THE CWA. WILL NEED TO ANALYZE FUTURE MODEL RUNS TO
SEE IF THIS WAVE WILL TURN OUT TO BE EVEN STRONGER THAN CURRENTLY
INDICATED...AND THUS CREATE CHANCES FOR PRECIP. ATTM...A SILENT
POP FORECAST WILL ENSUE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 94 66 93 67 / 10 0 0 10 10
TULIA 66 94 67 95 68 / 10 0 0 10 10
PLAINVIEW 66 94 68 94 69 / 10 0 0 10 10
LEVELLAND 66 93 66 94 69 / 10 0 0 10 10
LUBBOCK 71 94 68 96 70 / 10 0 0 10 10
DENVER CITY 67 91 66 94 68 / 10 0 0 10 10
BROWNFIELD 67 92 67 95 69 / 10 0 0 10 10
CHILDRESS 71 100 73 101 73 / 10 0 0 10 10
SPUR 70 96 71 98 72 / 10 0 0 10 10
ASPERMONT 73 98 74 101 74 / 10 0 0 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/29
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
226 PM CDT WED JUL 18 2012
.SHORT TERM...TONIGHT AND THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COMPLICATED
SYNOPTIC PATTERN ACROSS THE REGION AT THE MOMENT. FIRST
OFF...REMNANT MCV CONTINUES TO WEAKEN AS IT MOVES NORTHEAST OVER
NORTHWEST WISCONSIN. CAN STILL EXPECT AN AREA OF SHOWERS AND
THUNDERSTORMS MOVING ACROSS NORTH-CENTRAL AND FAR NORTHEAST
WISCONSIN THROUGH LATE AFTERNOON. PERHAPS A BIGGER CONCERN WILL BE
A DEVELOPING CLUSTER OF SHOWERS AND STORMS OVER SOUTHERN MINNESOTA
AND NORTHERN IOWA THAT IS TRACKING NORTHEAST AS WELL. THIS CLUSTER
IS ALSO GETTING THAT MCV LOOK TO IT AND ITS TRACKING IN THE SAME
TRAJECTORY AS THE MCV FARTHER NORTH. THE LATEST TIMING WOULD CALL
FOR THIS NEXT CLUSTER OF STORMS TO MOVE INTO CENTRAL WISCONSIN
AROUND 00Z. OTHERWISE...THE 850MB BAROCLINIC ZONE REMAINS IN PLACE
FROM NW WISCONSIN TO AROUND KEWAUNEE THIS AFTERNOON. AS SHORTWAVE
ENERGY OVER THE PLAINS INTERACTS WITH THIS THERMAL
GRADIENT...THUNDERSTORM CHANCES AND SEVERITY ARE THE MAIN FORECAST
CONCERNS IN THE SHORT TERM.
TONIGHT...MODELS DO NOT HAVE THE CURRENT WEATHER HANDLED VERY
WELL...SO COULDNT REALLY RELY ON ANY PARTICULAR GUIDANCE. MCV
MOVING OVER NORTHWEST WISCONSIN IS PUTTING A MONKEY WRENCH INTO THE
PLANS...THOUGH THINK IT WILL CONTINUE TO GRADUALLY WEAKEN AS IT
MOVES EAST. WHAT IMPACT THIS MCV WILL HAVE ON THUNDERSTORM
DEVELOPMENT FOR TONIGHT IS NOT CLEAR. IT MAY NOT HAVE MUCH IMPACT
ASSUMING THE STRENGTHENING TRENDS OF THE THUNDERSTORM CLUSTER OVER
SOUTHERN MINNESOTA CONTINUE. AS MENTIONED EARLIER...THIS
THUNDERSTORM COMPLEX WILL ARRIVE EARLY THIS EVENING OVER CENTRAL
WISCONSIN BEFORE TRACKING OVER THE FOX VALLEY AND NE WISCONSIN LATER
IN THE EVENING ASSUMING ITS DIRECTION OF TRAVEL DOES NOT CHANGE. IT WILL
ENCOUNTER ELEVATED CAPES TONIGHT FROM ABOUT 500-800 J/KG SO CANNOT
RULE OUT A STORM BECOMING FEISTY AND PRODUCING NEAR SEVERE
WEATHER...BUT ODDS OF ANYTHING SEVERE HAPPENING IS LOW. HEAVY RAIN
LOOKS TO BE THE MAIN THREAT AND 1 TO 2 INCHES OF RAIN APPEARS POSSIBLE.
HAVE BROAD BRUSHED POPS FOR THE 12 HOUR PERIOD TONIGHT AND HAVE
INCREASED THEM TO LIKELY. WITH THE EXPECTED CLOUD COVER AND
STORMS...RAISED LOWS A COUPLE DEGREES.
THURSDAY...THE SHORTWAVE TROUGH WILL PASS ACROSS THE FORECAST AREA
DURING THE MORNING AND HELP PUSH THE 850MB BAROCLINIC ZONE TO THE
SOUTH BY MIDDAY. WITH CONVERGENCE WEAKENING DURING THE AM
HOURS...WILL KEEP POPS LOW TOMORROW MORNING THEN CLEAR THEM OUT FOR
THE AFTERNOON. PLENTY OF MORNING CLOUD COVER...PLUS LINGERING LOW
LEVEL MOISTURE IN COOL EAST FLOW...SHOULD KEEP TEMPERATURES DOWN
AND WILL SHOW HIGHS IN THE MIDDLE TO UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...PCPN TRENDS
AND TEMPERATURES ARE THE MAIN FCST CONCERNS.
WEAK HIGH PRESSURE WILL MOVE THROUGH THE AREA ON THURSDAY NIGHT
AND FRIDAY. A FEW MODELS GENERATE SOME LGT PCPN ACROSS NC WI ON
FRIDAY...DUE TO WAA/ISENT LIFT...INCREASING MOISTURE CONVERGENCE
AND ELEVATED INSTABILITY. CURRENT THINKING IS THAT THIS PCPN WILL
STAY NW OF GRB CWA THROUGH FRIDAY.
A COLD FRONT WILL WORK ITS WAY INTO NORTHERN WI ON FRIDAY NIGHT...
THEN GRADUALLY SAG SOUTH ACROSS THE FORECAST AREA OVER THE WEEKEND.
THIS FRONT SHOULD BE THE FOCUS FOR ISOLD/SCT TSTM DEVELOPMENT.
ALTHOUGH IT IS FAR FROM A CERTAINTY...MODELS ARE SUGGESTING THAT
THE FRONT MAY SAG FAR ENOUGH SOUTH ON MONDAY/MONDAY NIGHT TO ALLOW
WEAK HIGH PRESSURE TO SETTLE INTO NE WI. WILL TAKE A CHANCE ON A
DRY FCST FOR THOSE PERIODS FOR NOW.
LOW PRESSURE EXPECTED TO MOVE ACROSS SOUTHERN CANADA DURING THE
MIDWEEK PERIOD...WITH A COLD FRONT APPROACHING FROM THE NORTHERN
PLAINS. SW FLOW IN ADVANCE OF THE FRONT WILL LIFT THE OLD FRONT
BACK TO NORTH AS A WARM FRONT...BRINGING A SURGE OF WARMER AND
MORE UNSTABLE AIR INTO C/NE WI. WOULD NOT BE SURPRISED IF WE
SEE A PERIOD OR TWO OF ORGANIZED SEVERE WX LATER TUESDAY INTO
WEDNESDAY...AS INCREASING DEEP LAYER SHEAR COMBINES WITH THE
BUILDING INSTABILITY.
TEMPERATURES WILL REMAIN ABOVE NORMAL IN THE 80S TO AROUND 90
DURING THE PERIOD...AS H8 TEMPS STAY IN THE UPPER TEENS TO AROUND
20 C RANGE. WARMER H8 TEMPS ARE POSSIBLY BY NEXT WEDS...BUT TEMPS
MAY HELD BACK SOMEWHAT BY CONVECTION.
&&
.AVIATION...DIFFICULT FORECAST FOR THE AIRPORTS THIS GO
AROUND...MAINLY REVOLVING AROUND TIMING OF SHOWERS AND
THUNDERSTORMS. NEXT ROUND WILL MOVE ACROSS NORTH-CENTRAL AND
NORTHEAST WISCONSIN THIS AFTERNOON AND BRING MVFR CIGS AND POSSIBLY
IFR VSBYS IN THE HEAVIER RAIN CORES. THEREAFTER...THINK WILL SEE A
BREAK FOR A FEW HOURS AS THE NEXT ROUND ORGANIZES OVER THE NORTHERN
PLAINS. TIMING WHEN THIS NEXT ROUND ARRIVES IS MERELY GUESS WORK AT
THIS POINT. BEST GUEST THOUGH IS THIS NEXT ROUND WILL ARRIVE MID TO
LATE EVENING ONWARD WHEN AN UPPER LEVEL DISTURBANCE ARRIVES. THOUGH
NOT EXPECTING SEVERE WEATHER AT THIS TIME...LOWER CIGS CAN BE
EXPECTED WITH THIS NEXT ROUND INTO THE IFR RANGE. SOME IMPROVEMENT
IN CONDITIONS APPEARS LIKELY BY LATE MORNING TOMORROW.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/KIECKBUSCH