Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/18/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
940 AM MST THU JUL 16 2015
.SYNOPSIS...
AFTERNOON SHOWERS AND THUNDERSTORMS WILL BECOME MORE COMMON ACROSS
THE REGION LATER THIS WEEK AS TROPICAL MOISTURE ASSOCIATED WITH
HURRICANE DOLORES MOVES INTO THE DESERT SOUTHWEST. THIS WILL ALSO
RESULT IN CLOUDY SKIES AND BELOW NORMAL TEMPERATURES THIS WEEKEND.
SOMEWHAT DRIER AIR WILL MOVE INTO THE REGION EARLY NEXT WEEK WITH
STORM CHANCES MIGRATING TO THE HIGHER TERRAIN LOCATIONS EAST OF
PHOENIX.
&&
.DISCUSSION...
MOSTLY CLEAR SKIES ACROSS THE CENTRAL DESERTS AND SOUTHEAST
CALIFORNIA THIS MORNING. TEMPERATURES ARE RUNNING VERY CLOSE TO THIS
TIME YESTERDAY WITH DEWPOINTS A HANDFUL OF DEGREES HIGHER THAN
YESTERDAY. 12Z SOUNDING OUT OF TUCSON SHOWS A MARGINAL INCREASE IN
MOISTURE...STRETCHING FARTHER UP THE COLUMN...WHILE THE PHOENIX
SOUNDING HAS THE OPPOSITE OBSERVATION WITH MORE OF THE MOISTURE
CONFINED TO THE BOUNDARY LAYER/LOWER LEVELS AND SLIGHT DECREASE IN
PWAT MOISTURE.
INTERPRETING THE WATER VAPOR IMAGERY THIS MORNING...CURRENT HURRICANE
DOLORES REMAINS LOCATED OFF THE SOUTHWEST COAST OF BAJA AND IS
PROJECTED TO MOVE TO THE NORTHWEST OVER THE NEXT 48 HOURS. AN AREA OF
DEFORMATION IN THE MID-LEVEL WIND FIELDS SETTLES IN ACROSS NORTHERN
SONORA AND BAJA THROUGH SATURDAY WITH A SOUTHWESTERLY FLOW...AIDING
IN MOISTURE ADVECTION FROM DOLORES. TURNING ATTENTION TO THE
EAST...A TROPICAL UPPER TROPOSPHERIC TROUGH CAN BE IDENTIFIED IN THE
WESTERN GULF OF MEXICO. AN INVERTED TROUGH WILL HELP ADVECT THIS
FEATURE NORTHWESTWARD TOWARDS ARIZONA BY SATURDAY. THIS COULD BE THE
DRIVING FACTOR TO BRING THE DYNAMICS NEEDED TO DEVELOP CONVECTION.
IN THE SHORT TERM FOR NOW...THE FORECAST IS IN GOOD SHAPE.
.PREVIOUS DISCUSSION.../ISSUED AT 245 AM MST 16 JULY/...
EARLY MORNING WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY FLOW ACROSS
THE REGION...WITH A PLUME OF MOISTURE STRETCHING ACROSS EASTERN
ARIZONA INTO MUCH OF NEW MEXICO. UPPER LEVEL MOISTURE ASSOCIATED WITH
HURRICANE DOLORES IS ALSO EVIDENT ACROSS SOUTHERN BAJA THIS MORNING
AND BLENDED TPW IMAGERY SUGGESTS PWATS ARE ALREADY APPROACHING
1.5-1.7+ INCHES SOUTH OF THE INTERNATIONAL BORDER. ACROSS THE DESERTS
THIS MORNING...ISOLATED CONVECTION CONTINUES TO PERCOLATE SOUTH OF
PHOENIX AS OF 09Z WITH A WEAK WESTWARD- PROGRESSING OUTFLOW BOUNDARY
SERVING AS THE TRIGGER. SPC MESOANALYSIS AND RAP SOUNDINGS SUGGEST
THERE`S APPROXIMATELY 300-500 J/KG OF ELEVATED CAPE IN THE ATMOSPHERE
TO WORK WITH. IN THE VERY SHORT TERM...I`LL HANG ONTO ISOLATED
SHOWERS AND THUNDERSTORMS IN THE FORECAST UNTIL DAYBREAK /AT WHICH
POINT MOST OF THE OUTFLOWS SHOULD HAVE LOST THEIR MOMENTUM/.
SHORT TERM CONVECTIVE ALLOWING MODELS SUGGEST A FAIRLY LOW-GRADE
MONSOON DAY TODAY WITH SHOWERS/STORMS DEVELOPING IN THE
CLIMATOLOGICALLY FAVORED AREAS NORTH/EAST OF PHOENIX...AS WELL AS ON
THE HIGHER PEAKS SOUTH OF GILA BEND. INHERITED POPS KEPT MOST OF THE
ACTIVITY OUT OF THE PHOENIX AREA UNTIL AFTER 00Z AND THIS STILL
SEEMS REASONABLE. IF ANYTHING FIRES OVER THE PHOENIX METRO...IT`LL
BE COURTESY OF COLLIDING OUTFLOWS AS HAS BEEN THE CASE FOR THE PAST
FEW DAYS.
MOISTURE FROM DOLORES IS FORECAST TO MOVE INTO ARIZONA AT SOME POINT
DURING THE DAY FRIDAY...RESULTING IN A NOTICEABLE INCREASE IN
HUMIDITIES. DETERMINISTIC GUIDANCE FROM THE EUROPEAN/GFS/NAM ALL
SUGGEST PWATS WILL CLIMB TO AROUND 1.6-1.8 INCHES ACROSS THE AREA
/POSSIBLY AS HIGH AS 2 INCHES AROUND YUMA/ FRIDAY NIGHT. PROBABILISTIC
GUIDANCE IS ALSO SUGGESTING SIMILAR VALUES...LEADING TO A CONTINUED HIGH
CONFIDENCE FORECAST THAT UNUSUALLY HIGH AMOUNTS OF MOISTURE /VALUES
APPROACHING THE 97-99TH PERCENTILE/ WILL RESIDE ACROSS THE AREA THIS
WEEKEND. OBVIOUSLY...ELEVATED MOISTURE IS ONLY ONE-THIRD OF THE
CONVECTIVE PUZZLE BUT ALL GUIDANCE SUGGESTS A MARKED JUMP IN MLCAPES
FRIDAY AFTERNOON/EVENING ON THE LEADING EDGE OF THE AFOREMENTIONED
MOISTURE ADVECTION. EXACTLY WHAT FORCING MECHANISM WILL TRIGGER
CONVECTION IS STILL TO BE DETERMINED...BUT THERE`S A FEW SUBTLE
CIRCULATIONS IN THE 500-700MB LAYER OVER SONORA PER THE NAM/GFS
FORECAST THAT I`VE RAISED POPS A BIT FRIDAY AFTERNOON/EVENING. SOME
OF THE GUIDANCE SUGGESTS CONVECTION WILL DEVELOP LATE FRIDAY
NIGHT/SATURDAY MORNING AND I RETAINED ELEVATED POPS THROUGH THIS
PERIOD AS WELL.
SATURDAY IS PROBABLY BE THE MOST CHALLENGING DAY TO FIGURE OUT...AS
ELEVATED PWATS AND DEBRIS CLOUD COVER SHOULD BE ESTABLISHED ACROSS
THE AREA...NOT TO MENTION THE ATMOSPHERE COULD BE CONTAMINATED FROM
CONVECTION THE NIGHT BEFORE. MEANWHILE TEMPERATURES ALOFT WILL BE
WARMING TO AROUND -6 TO -7 C AT 500MB AND FORECAST PROFILES APPEAR
TO BE RELATIVELY STABLE. ANY SORT OF REMNANT MCV FROM STORMS THE
NIGHT BEFORE COULD SERVE AT THE FOCAL POINT FOR ADDITIONAL SHOWERS
ON SATURDAY BUT OVERALL IT MAY END UP BEING A CLOUDY/MUGGY DAY WITH
OCCASIONAL SHOWERS AND A RUMBLE OR TWO OF THUNDER. AS NEARLY ALL
DETERMINISTIC AND PROBABILISTIC PAINT IN 50-70 POPS ACROSS THE AREA
SATURDAY...I`VE FOLLOWED THIS TREND AND INCREASED OUR POPS AS WELL.
EXACT TIMING OF WHERE/WHEN STORMS WILL FORM IS DIFFICULT TO PIN
DOWN...SO IN REALITY THE POPS ARE LIKELY SPREAD OUT OVER TOO LARGE
OF AN AREA. MADE SURE TO INDICATE ELEVATED VALUES ACROSS SOUTHWEST
ARIZONA/SOUTHEAST CALIFORNIA AS WELL AS THEY WILL ALSO SEE WELL
ABOVE NORMAL PRECIP CHANCES THIS WEEKEND. MANY OF THE ABOVE
ARGUMENTS ARE ALSO VALID DURING THE DAY SUNDAY. HIGH CONFIDENCE IN
ELEVATED MOISTURE. LOW CONFIDENCE IN EXACT PLACEMENT/TIMING OF
SHOWERS.
BY MONDAY THE FLOW ALOFT TAKES A TURN OUT OF THE SOUTHWEST WHICH
WILL BEGIN A SLOW PERIOD OF DRY ADVECTION /ESPECIALLY ACROSS
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA/. THIS TREND IS SUPPORTED
BY THE DETERMINISTIC/PROBABILISTIC GUIDANCE AND IS EXPECTED TO
CONTINUE THROUGH MOST OF NEXT WEEK WITH MOISTURE/INSTABILITY/PRECIP
CHANCES MIGRATING AWAY FROM THE DESERTS AND INTO THE MOUNTAINS.
CERTAINLY NOT TO SAY THE DESERTS WILL BE DRYING OUT ENTIRELY...BUT
THERE`S A CLEAR EASTWARD SHIFT IN ALL OF THE KEY PARAMETERS FROM
MONDAY ONWARD. WILL MAINTAIN CLIMO-LIKE POPS THROUGHOUT THE EXTENDED
PORTION OF THE FORECAST...WITH A SMALL NUDGE UPWARD LATE NEXT WEEK
WHEN THE FLOW TAKES ON IT`S MORE TYPICAL SOUTHEASTERLY DIRECTION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
LIGHT TYPICAL EASTERLY AM WINDS WILL TRANSITION TO W-SW HEADINGS BY
THE EARLY AFTERNOON...WITH SOME ELEVATED BREEZES PSBL DURING PEAK
AFTERNOON HEATING. MORNING SCT-BKN DEBRIS CLOUDS WILL CONTINUE TO
DISSIPATE AND THIN WITH AFTN SKIES HOSTING SOME FEW-SCT CU FIELDS
GNLY 10KFT OR ABOVE. STORM ACTIVITY PSBL AGAIN ON THE SOUTHERN
PERIPHERY OF THE PHX METRO AND OVER THE HIGHER TERRAIN TO THE
EAST...WITH INITIAL IMPACT BEING STORM OUTFLOW INTRUSION AND
SUBSEQUENT WIND SHIFTS. INTERSECTING OUTFLOWS MAY SUPPORT POP-UP
SHOWER ACTIVITY OVERNIGHT...HEDGED WITH VCSH IN THE KIWA 12Z TAF
OVERNIGHT FOR NOW.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR SKIES AND MOSTLY LIGHT AM WINDS TO CONTINUE FOR KIPL AND KBLH.
SOUTH TO SOUTHEASTERLY WINDS INCREASING DURING THE DAY WITH SOME
GUSTINESS IN THE 15-20KT RANGE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A DEEP TROPICAL MOISTURE PLUME...COURTESY OF CURRENT EASTERN PACIFIC
TROPICAL CYCLONE DOLORES...WILL CONTINUE TO STREAM INTO THE
SOUTHWEST REGION SIGNIFICANTLY BOOSTING RAIN AND STORM CHANCES FOR
SATURDAY AND SUNDAY. NOTE...ONLY THE ASSOCIATED MOISTURE FROM THE
SYSTEM WILL MOVE INTO THE AREA...NOT THE ACTUAL CIRCULATION ITSELF.
UNDER SIGNIFICANT CLOUD COVER...DAYTIME HIGHS OVER THE WEEKEND WILL
STRUGGLE TO HIT THE CENTURY MARK...EVEN FOR THE WARMEST LOWEST
DESERT LOCALES. CONDITIONS WILL GRADUALLY DRY OUT AND WARM UP BY
EARLY NEXT WEEK AS DRIER FLOW ALOFT OUT OF THE WEST TRANSITIONS INTO
THE AREA
&&
.SPOTTER INFORMATION STATEMENT...
STORM CONDITIONS OVER THE WEEKEND MAY WARRANT SPOTTER DEPLOYMENT.
SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS
ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...DEWEY
PREVIOUS DISCUSSION...LEINS
AVIATION...NOTLE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
500 AM MST THU JUL 16 2015
.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
AFTERNOON SHOWERS AND THUNDERSTORMS WILL BECOME MORE COMMON ACROSS
THE REGION LATER THIS WEEK AS TROPICAL MOISTURE ASSOCIATED WITH
HURRICANE DOLORES MOVES INTO THE DESERT SOUTHWEST. THIS WILL ALSO
RESULT IN CLOUDY SKIES AND BELOW NORMAL TEMPERATURES THIS WEEKEND.
SOMEWHAT DRIER AIR WILL MOVE INTO THE REGION EARLY NEXT WEEK WITH
STORM CHANCES MIGRATING TO THE HIGHER TERRAIN LOCATIONS EAST OF
PHOENIX.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY FLOW ACROSS
THE REGION...WITH A PLUME OF MOISTURE STRETCHING ACROSS EASTERN
ARIZONA INTO MUCH OF NEW MEXICO. UPPER LEVEL MOISTURE ASSOCIATED
WITH HURRICANE DOLORES IS ALSO EVIDENT ACROSS SOUTHERN BAJA THIS
MORNING AND BLENDED TPW IMAGERY SUGGESTS PWATS ARE ALREADY
APPROACHING 1.5-1.7+ INCHES SOUTH OF THE INTERNATIONAL BORDER.
ACROSS THE DESERTS THIS MORNING...ISOLATED CONVECTION CONTINUES TO
PERCOLATE SOUTH OF PHOENIX AS OF 09Z WITH A WEAK WESTWARD-
PROGRESSING OUTFLOW BOUNDARY SERVING AS THE TRIGGER. SPC
MESOANALYSIS AND RAP SOUNDINGS SUGGEST THERE`S APPROXIMATELY 300-500
J/KG OF ELEVATED CAPE IN THE ATMOSPHERE TO WORK WITH. IN THE VERY
SHORT TERM...I`LL HANG ONTO ISOLATED SHOWERS AND THUNDERSTORMS IN
THE FORECAST UNTIL DAYBREAK /AT WHICH POINT MOST OF THE OUTFLOWS
SHOULD HAVE LOST THEIR MOMENTUM/.
SHORT TERM CONVECTIVE ALLOWING MODELS SUGGEST A FAIRLY LOW-GRADE
MONSOON DAY TODAY WITH SHOWERS/STORMS DEVELOPING IN THE
CLIMATOLOGICALLY FAVORED AREAS NORTH/EAST OF PHOENIX...AS WELL AS ON
THE HIGHER PEAKS SOUTH OF GILA BEND. INHERITED POPS KEPT MOST OF THE
ACTIVITY OUT OF THE PHOENIX AREA UNTIL AFTER 00Z AND THIS STILL
SEEMS REASONABLE. IF ANYTHING FIRES OVER THE PHOENIX METRO...IT`LL
BE COURTESY OF COLLIDING OUTFLOWS AS HAS BEEN THE CASE FOR THE PAST
FEW DAYS.
MOISTURE FROM DOLORES IS FORECAST TO MOVE INTO ARIZONA AT SOME POINT
DURING THE DAY FRIDAY...RESULTING IN A NOTICEABLE INCREASE IN
HUMIDITIES. DETERMINISTIC GUIDANCE FROM THE EUROPEAN/GFS/NAM ALL
SUGGEST PWATS WILL CLIMB TO AROUND 1.6-1.8 INCHES ACROSS THE AREA
/POSSIBLY AS HIGH AS 2 INCHES AROUND YUMA/ FRIDAY NIGHT. PROBABILISTIC
GUIDANCE IS ALSO SUGGESTING SIMILAR VALUES...LEADING TO A CONTINUED HIGH
CONFIDENCE FORECAST THAT UNUSUALLY HIGH AMOUNTS OF MOISTURE /VALUES
APPROACHING THE 97-99TH PERCENTILE/ WILL RESIDE ACROSS THE AREA THIS
WEEKEND. OBVIOUSLY...ELEVATED MOISTURE IS ONLY ONE-THIRD OF THE
CONVECTIVE PUZZLE BUT ALL GUIDANCE SUGGESTS A MARKED JUMP IN MLCAPES
FRIDAY AFTERNOON/EVENING ON THE LEADING EDGE OF THE AFOREMENTIONED
MOISTURE ADVECTION. EXACTLY WHAT FORCING MECHANISM WILL TRIGGER
CONVECTION IS STILL TO BE DETERMINED...BUT THERE`S A FEW SUBTLE
CIRCULATIONS IN THE 500-700MB LAYER OVER SONORA PER THE NAM/GFS
FORECAST THAT I`VE RAISED POPS A BIT FRIDAY AFTERNOON/EVENING. SOME
OF THE GUIDANCE SUGGESTS CONVECTION WILL DEVELOP LATE FRIDAY
NIGHT/SATURDAY MORNING AND I RETAINED ELEVATED POPS THROUGH THIS
PERIOD AS WELL.
SATURDAY IS PROBABLY BE THE MOST CHALLENGING DAY TO FIGURE OUT...AS
ELEVATED PWATS AND DEBRIS CLOUD COVER SHOULD BE ESTABLISHED ACROSS
THE AREA...NOT TO MENTION THE ATMOSPHERE COULD BE CONTAMINATED FROM
CONVECTION THE NIGHT BEFORE. MEANWHILE TEMPERATURES ALOFT WILL BE
WARMING TO AROUND -6 TO -7 C AT 500MB AND FORECAST PROFILES APPEAR
TO BE RELATIVELY STABLE. ANY SORT OF REMNANT MCV FROM STORMS THE
NIGHT BEFORE COULD SERVE AT THE FOCAL POINT FOR ADDITIONAL SHOWERS
ON SATURDAY BUT OVERALL IT MAY END UP BEING A CLOUDY/MUGGY DAY WITH
OCCASIONAL SHOWERS AND A RUMBLE OR TWO OF THUNDER. AS NEARLY ALL
DETERMINISTIC AND PROBABILISTIC PAINT IN 50-70 POPS ACROSS THE AREA
SATURDAY...I`VE FOLLOWED THIS TREND AND INCREASED OUR POPS AS WELL.
EXACT TIMING OF WHERE/WHEN STORMS WILL FORM IS DIFFICULT TO PIN
DOWN...SO IN REALITY THE POPS ARE LIKELY SPREAD OUT OVER TOO LARGE
OF AN AREA. MADE SURE TO INDICATE ELEVATED VALUES ACROSS SOUTHWEST
ARIZONA/SOUTHEAST CALIFORNIA AS WELL AS THEY WILL ALSO SEE WELL
ABOVE NORMAL PRECIP CHANCES THIS WEEKEND. MANY OF THE ABOVE
ARGUMENTS ARE ALSO VALID DURING THE DAY SUNDAY. HIGH CONFIDENCE IN
ELEVATED MOISTURE. LOW CONFIDENCE IN EXACT PLACEMENT/TIMING OF
SHOWERS.
BY MONDAY THE FLOW ALOFT TAKES A TURN OUT OF THE SOUTHWEST WHICH
WILL BEGIN A SLOW PERIOD OF DRY ADVECTION /ESPECIALLY ACROSS
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA/. THIS TREND IS SUPPORTED
BY THE DETERMINISTIC/PROBABILISTIC GUIDANCE AND IS EXPECTED TO
CONTINUE THROUGH MOST OF NEXT WEEK WITH MOISTURE/INSTABILITY/PRECIP
CHANCES MIGRATING AWAY FROM THE DESERTS AND INTO THE MOUNTAINS.
CERTAINLY NOT TO SAY THE DESERTS WILL BE DRYING OUT ENTIRELY...BUT
THERE`S A CLEAR EASTWARD SHIFT IN ALL OF THE KEY PARAMETERS FROM
MONDAY ONWARD. WILL MAINTAIN CLIMO-LIKE POPS THROUGHOUT THE EXTENDED
PORTION OF THE FORECAST...WITH A SMALL NUDGE UPWARD LATE NEXT WEEK
WHEN THE FLOW TAKES ON IT`S MORE TYPICAL SOUTHEASTERLY DIRECTION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
LIGHT TYPICAL EASTERLY AM WINDS WILL TRANSITION TO W-SW HEADINGS BY
THE EARLY AFTERNOON...WITH SOME ELEVATED BREEZES PSBL DURING PEAK
AFTERNOON HEATING. MORNING SCT-BKN DEBRIS CLOUDS WILL CONTINUE TO
DISSIPATE AND THIN WITH AFTN SKIES HOSTING SOME FEW-SCT CU FIELDS
GNLY 10KFT OR ABOVE. STORM ACTIVITY PSBL AGAIN ON THE SOUTHERN
PERIPHERY OF THE PHX METRO AND OVER THE HIGHER TERRAIN TO THE
EAST...WITH INITIAL IMPACT BEING STORM OUTFLOW INTRUSION AND
SUBSEQUENT WIND SHIFTS. INTERSECTING OUTFLOWS MAY SUPPORT POP-UP
SHOWER ACTIVITY OVERNIGHT...HEDGED WITH VCSH IN THE KIWA 12Z TAF
OVERNIGHT FOR NOW.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR SKIES AND MOSTLY LIGHT AM WINDS TO CONTINUE FOR KIPL AND KBLH.
SOUTH TO SOUTHEASTERLY WINDS INCREASING DURING THE DAY WITH SOME
GUSTINESS IN THE 15-20KT RANGE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A DEEP TROPICAL MOISTURE PLUME...COURTESY OF CURRENT EASTERN PACIFIC
TROPICAL CYCLONE DOLORES...WILL CONTINUE TO STREAM INTO THE
SOUTHWEST REGION SIGNIFICANTLY BOOSTING RAIN AND STORM CHANCES FOR
SATURDAY AND SUNDAY. NOTE...ONLY THE ASSOCIATED MOISTURE FROM THE
SYSTEM WILL MOVE INTO THE AREA...NOT THE ACTUAL CIRCULATION ITSELF.
UNDER SIGNIFICANT CLOUD COVER...DAYTIME HIGHS OVER THE WEEKEND WILL
STRUGGLE TO HIT THE CENTURY MARK...EVEN FOR THE WARMEST LOWEST
DESERT LOCALES. CONDITIONS WILL GRADUALLY DRY OUT AND WARM UP BY
EARLY NEXT WEEK AS DRIER FLOW ALOFT OUT OF THE WEST TRANSITIONS INTO
THE AREA
&&
.SPOTTER INFORMATION STATEMENT...
STORM CONDITIONS OVER THE WEEKEND MAY WARRANT SPOTTER DEPLOYMENT.
SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS
ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
245 AM MST THU JUL 16 2015
.SYNOPSIS...
AFTERNOON SHOWERS AND THUNDERSTORMS WILL BECOME MORE COMMON ACROSS
THE REGION LATER THIS WEEK AS TROPICAL MOISTURE ASSOCIATED WITH
HURRICANE DOLORES MOVES INTO THE DESERT SOUTHWEST. THIS WILL ALSO
RESULT IN CLOUDY SKIES AND BELOW NORMAL TEMPERATURES THIS WEEKEND.
SOMEWHAT DRIER AIR WILL MOVE INTO THE REGION EARLY NEXT WEEK WITH
STORM CHANCES MIGRATING TO THE HIGHER TERRAIN LOCATIONS EAST OF
PHOENIX.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY FLOW ACROSS
THE REGION...WITH A PLUME OF MOISTURE STRETCHING ACROSS EASTERN
ARIZONA INTO MUCH OF NEW MEXICO. UPPER LEVEL MOISTURE ASSOCIATED WITH
HURRICANE DOLORES IS ALSO EVIDENT ACROSS SOUTHERN BAJA THIS MORNING
AND BLENDED TPW IMAGERY SUGGESTS PWATS ARE ALREADY APPROACHING
1.5-1.7+ INCHES SOUTH OF THE INTERNATIONAL BORDER. ACROSS THE
DESERTS THIS MORNING...ISOLATED CONVECTION CONTINUES TO PERCOLATE
SOUTH OF PHOENIX AS OF 09Z WITH A WEAK WESTWARD-PROGRESSING OUTFLOW
BOUNDARY SERVING AS THE TRIGGER. SPC MESOANALYSIS AND RAP SOUNDINGS
SUGGEST THERE`S APPROXIMATELY 300-500 J/KG OF ELEVATED CAPE IN THE
ATMOSPHERE TO WORK WITH. IN THE VERY SHORT TERM...I`LL HANG ONTO
ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST UNTIL DAYBREAK /AT
WHICH POINT MOST OF THE OUTFLOWS SHOULD HAVE LOST THEIR MOMENTUM/.
SHORT TERM CONVECTIVE ALLOWING MODELS SUGGEST A FAIRLY LOW-GRADE
MONSOON DAY TODAY WITH SHOWERS/STORMS DEVELOPING IN THE
CLIMATOLOGICALLY FAVORED AREAS NORTH/EAST OF PHOENIX...AS WELL AS ON
THE HIGHER PEAKS SOUTH OF GILA BEND. INHERITED POPS KEPT MOST OF THE
ACTIVITY OUT OF THE PHOENIX AREA UNTIL AFTER 00Z AND THIS STILL SEEMS
REASONABLE. IF ANYTHING FIRES OVER THE PHOENIX METRO...IT`LL BE
COURTESY OF COLLIDING OUTFLOWS AS HAS BEEN THE CASE FOR THE PAST FEW
DAYS.
MOISTURE FROM DOLORES IS FORECAST TO MOVE INTO ARIZONA AT SOME POINT
DURING THE DAY FRIDAY...RESULTING IN A NOTICEABLE INCREASE IN
HUMIDITIES. DETERMINISTIC GUIDANCE FROM THE EUROPEAN/GFS/NAM ALL
SUGGEST PWATS WILL CLIMB TO AROUND 1.6-1.8 INCHES ACROSS THE AREA
/POSSIBLY AS HIGH AS 2 INCHES AROUND YUMA/ FRIDAY NIGHT. PROBABILISTIC
GUIDANCE IS ALSO SUGGESTING SIMILAR VALUES...LEADING TO A CONTINUED HIGH
CONFIDENCE FORECAST THAT UNUSUALLY HIGH AMOUNTS OF MOISTURE /VALUES
APPROACHING THE 97-99TH PERCENTILE/ WILL RESIDE ACROSS THE AREA THIS
WEEKEND. OBVIOUSLY...ELEVATED MOISTURE IS ONLY ONE-THIRD OF THE
CONVECTIVE PUZZLE BUT ALL GUIDANCE SUGGESTS A MARKED JUMP IN MLCAPES
FRIDAY AFTERNOON/EVENING ON THE LEADING EDGE OF THE AFOREMENTIONED MOISTURE
ADVECTION. EXACTLY WHAT FORCING MECHANISM WILL TRIGGER CONVECTION IS
STILL TO BE DETERMINED...BUT THERE`S A FEW SUBTLE CIRCULATIONS IN THE
500-700MB LAYER OVER SONORA PER THE NAM/GFS FORECAST THAT I`VE RAISED
POPS A BIT FRIDAY AFTERNOON/EVENING. SOME OF THE GUIDANCE SUGGESTS
CONVECTION WILL DEVELOP LATE FRIDAY NIGHT/SATURDAY MORNING AND I
RETAINED ELEVATED POPS THROUGH THIS PERIOD AS WELL.
SATURDAY IS PROBABLY BE THE MOST CHALLENGING DAY TO FIGURE OUT...AS
ELEVATED PWATS AND DEBRIS CLOUD COVER SHOULD BE ESTABLISHED ACROSS
THE AREA...NOT TO MENTION THE ATMOSPHERE COULD BE CONTAMINATED FROM
CONVECTION THE NIGHT BEFORE. MEANWHILE TEMPERATURES ALOFT WILL BE
WARMING TO AROUND -6 TO -7 C AT 500MB AND FORECAST PROFILES APPEAR TO
BE RELATIVELY STABLE. ANY SORT OF REMNANT MCV FROM STORMS THE NIGHT
BEFORE COULD SERVE AT THE FOCAL POINT FOR ADDITIONAL SHOWERS ON
SATURDAY BUT OVERALL IT MAY END UP BEING A CLOUDY/MUGGY DAY WITH
OCCASIONAL SHOWERS AND A RUMBLE OR TWO OF THUNDER. AS NEARLY ALL
DETERMINISTIC AND PROBABILISTIC PAINT IN 50-70 POPS ACROSS THE AREA
SATURDAY...I`VE FOLLOWED THIS TREND AND INCREASED OUR POPS AS WELL.
EXACT TIMING OF WHERE/WHEN STORMS WILL FORM IS DIFFICULT TO PIN
DOWN...SO IN REALITY THE POPS ARE LIKELY SPREAD OUT OVER TOO LARGE OF
AN AREA. MADE SURE TO INDICATE ELEVATED VALUES ACROSS SOUTHWEST
ARIZONA/SOUTHEAST CALIFORNIA AS WELL AS THEY WILL ALSO SEE WELL ABOVE
NORMAL PRECIP CHANCES THIS WEEKEND. MANY OF THE ABOVE ARGUMENTS ARE
ALSO VALID DURING THE DAY SUNDAY. HIGH CONFIDENCE IN ELEVATED
MOISTURE. LOW CONFIDENCE IN EXACT PLACEMENT/TIMING OF SHOWERS.
BY MONDAY THE FLOW ALOFT TAKES A TURN OUT OF THE SOUTHWEST WHICH WILL
BEGIN A SLOW PERIOD OF DRY ADVECTION /ESPECIALLY ACROSS SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA/. THIS TREND IS SUPPORTED BY THE
DETERMINISTIC/PROBABILISTIC GUIDANCE AND IS EXPECTED TO CONTINUE
THROUGH MOST OF NEXT WEEK WITH MOISTURE/INSTABILITY/PRECIP CHANCES
MIGRATING AWAY FROM THE DESERTS AND INTO THE MOUNTAINS. CERTAINLY NOT
TO SAY THE DESERTS WILL BE DRYING OUT ENTIRELY...BUT THERE`S A CLEAR
EASTWARD SHIFT IN ALL OF THE KEY PARAMETERS FROM MONDAY ONWARD. WILL
MAINTAIN CLIMO-LIKE POPS THROUGHOUT THE EXTENDED PORTION OF THE
FORECAST...WITH A SMALL NUDGE UPWARD LATE NEXT WEEK WHEN THE FLOW
TAKES ON IT`S MORE TYPICAL SOUTHEASTERLY DIRECTION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
DEBRIS CLOUDS GENERALLY AOA 10KFT WILL CONTINUE TO THIN OUT
OVERNIGHT LEADING TO MOSTLY CLEAR SKIES THURSDAY MORNING AND
AFTERNOON. OTHER THAN A FEW WEAK COLLIDING OUTFLOW BOUNDARIES FROM
EARLIER DISTANT THUNDERSTORMS THAT WILL DISRUPT EXPECTED DIURNAL
DIRECTIONS...WINDS WILL BE LIGHT THROUGH 18Z THURSDAY AT ALL
TERMINALS. DRIER MORE STABLE CONDITIONS OVER CENTRAL DESERTS WILL
KEEP THUNDERSTORMS WELL SOUTH AND EAST OF TERMINALS THURSDAY
AFTERNOON.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR SKIES AND LIGHT WINDS WILL PREVAIL OVER THE AREA THROUGH AT
LEAST THURSDAY MORNING. MAY SEE SOME ENHANCED WEST-SOUTHWEST WIND AT
KIPL THROUGH 08-09Z TONIGHT WITH SPEEDS UP TO 15KT OR SO...AND
SOUTHERLY WINDS INCREASING AT KBLH AFTER 17Z THURSDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A HURRICANE MOVING NORTHWEST OFF THE COAST OF BAJA CALIFORNIA WILL
SHED SIGNIFICANT TROPICAL MOISTURE WHICH IS EXPECTED TO MOVE BODILY
INLAND AND INTO ARIZONA AND SOUTHEAST CALIFORNIA. THIS WILL LEAD TO
A SHARP INCREASE IN HUMIDITY AS WELL AS HIGHLY ELEVATED CHANCES FOR
SHOWERS AND EMBEDDED THUNDERSTORMS EACH DAY WITH THE BEST RAIN
CHANCES ON THE WEEKEND. TEMPERATURES WILL LOWER MARKEDLY WITH HIGHS
OVER THE WEEKEND FALLING INTO THE 90S OR AROUND 100 DEGREES.
SOMEWHAT DRIER AND WARMED CONDITIONS ARE POSSIBLE MONDAY INTO
TUESDAY AS MOISTURE VALUES START TO FALL OFF. BREEZY TO LOCALLY
WINDY SOUTH TO SOUTHWEST WINDS ARE EXPECTED FRIDAY ESPECIALLY OVER
THE WESTERN DESERTS...WITH WINDS TO GRADUALLY TAPER OFF OVER THE
WEEKEND.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS MAY BE NEEDED THIS WEEKEND.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MEYERS
FIRE WEATHER...HIRSCH/CB
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
511 PM PDT FRI JUL 17 2015
...UPDATE FOR BLOWING DUST ADVISORY...
.SYNOPSIS...
HIGH PRESSURE BUILDING ALOFT WILL BRING SLIGHT WARMING TODAY WITH
MOSTLY SUNNY SKIES. TROPICAL MOISTURE FROM TROPICAL CYCLONE DOLORES
WILL BRING CLOUDS...WARM AND MUGGY CONDITIONS...AND ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS THIS WEEKEND. SOME REMNANT
MOISTURE WILL BRING THE CHANCE FOR AFTERNOON AND EARLY EVENING
THUNDERSTORMS AND SHOWERS FOR THE MOUNTAINS AND DESERTS MONDAY.
GRADUALLY DRIER FOR TUESDAY THROUGH FRIDAY OF NEXT WEEK ALONG WITH A
RETURN OF THE NIGHT AND MORNING COASTAL AND WESTERN VALLEY LOW
CLOUDS AND PATCHY FOG.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
QUICK UPDATE FOR BLOWING DUST HEADING INTO THE ANZA BORREGO DESERT
AND THE SOUTHERN COACHELLA VALLEY...COMING FROM THUNDERSTORMS IN
IMPERIAL COUNTY.
FROM PREVIOUS DISCUSSION...
MARINE LAYER STRATUS WAS A BIT SHALLOWER THIS MORNING...AS EARLIER
VISIBLE SATELLITE SHOWED LOW CLOUDS COVERING THE COAST AND WESTERN
VALLEYS...BUT NOT QUITE INTO THE INLAND EMPIRE. THE 12Z MIRAMAR
SOUNDING SHOWED AN 8 DEG C INVERSION AT AROUND 2300 FEET MSL...WITH
SOUTHWEST FLOW ALOFT. STRATUS HAS CLEARED OUT NICELY ACCORDING TO
THE LATEST VISIBLE IMAGES. WITH A RIDGE BUILDING IN
ALOFT...TEMPERATURES CURRENTLY ARE A 3-7 DEGREES HIGHER THAN AT THIS
TIME YESTERDAY.
DOLORES IS NOW A TROPICAL STORM AND LOCATED 420 MILES WEST OF CABO
SAN LUCAS AS IT CONTINUES TO MOVE TO THE WEST-NORTHWEST. AS THE
RIDGE TO THE EAST CONTINUES TO EXPAND WESTWARD INTO SOUTHERN
CALIFORNIA AND BAJA...IT WILL STEER DOLORES TO MORE OF A NORTHWEST
MOVEMENT THROUGH THIS WEEKEND...EVENTUALLY REACHING A POINT 200-300
MILES WEST OF NORTHERN BAJA BY LATE SUNDAY NIGHT AS IT BECOMES A
REMNANT LOW OR TROPICAL DEPRESSION. INCREASING MOISTURE...SOME FROM
DOLORES AND SOME FROM NORTHWEST MEXICO...WILL ADVECT INTO THE REGION
STARTING TONIGHT AND CONTINUING THROUGH SUNDAY...RESULTING IN
PLENTIFUL CLOUDS...INCREASINGLY HUMID AND MUGGY CONDITIONS...AND
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FROM THE COASTAL
WATERS TO THE DESERTS. GFS...NAM AND WRF SHOW PRECIPITABLE WATER
INCREASING TO 1.7-1.9 INCHES BY LATE SATURDAY AFTERNOON...AND
CONTINUING NEAR THOSE VALUES THROUGH SUNDAY. STARTING TONIGHT AND
CONTINUING THROUGH SUNDAY...THE BUFKIT FORECAST SOUNDINGS FROM THE
NAM AND GFS SHOW ELEVATED CAPE...WHICH INDICATES THAT THERE IS
ELEVATED INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS.
THERE WILL BE SMALL INCREASES IN MOISTURE THIS AFTERNOON UNDER
SOUTHWEST FLOW ALOFT...RESULTING IN SOME CUMULUS OVER THE MOUNTAINS
AND HIGH DESERTS. THE 19Z HRRR SHOWS SOME CONVECTION SPARKING OFF
THIS AFTERNOON OVER IMPERIAL COUNTY...WITH POSSIBLY SOME SPILLING
INTO OUR LOWER DESERTS...BUT CONFIDENCE IS LOW...ESPECIALLY WITH HOW
POOR THE 19Z HRRR INITIALIZED. MOISTURE CONTINUES TO INCREASE LATE
TONIGHT INTO SATURDAY MORNING...BUT NOT QUITE AS MUCH AS FOR THAT
TIME-PERIOD AS MODELS HAVE SHOWN PREVIOUSLY. NONE OF THE HIGH-RES
MODELS SHOW MUCH OF ANY ACCUMULATIONS DURING THAT TIME.
THUS...SHOWER/THUNDERSTORM CHANCES FOR OVERNIGHT TONIGHT ARE NOT
GREAT...BUT WILL KEEP IT IN THE FORECAST FOR NOW. IT MAY START OUT
AS MOSTLY VIRGA OR SPRINKLES. THEN...WE START TO SEE THE GOOD SURGE
OF MOISTURE COMING IN DURING SATURDAY AFTERNOON...WITH THE MAJORITY
OF MOISTURE LOCATED IN THE 700-300 MB LAYER...AND SOME ENHANCED
MOISTURE REACHING DOWN TO 850 MB. AT THAT TIME...A WEAK WAVE MAY
MOVE OVER THE AREA TO HELP TRIGGER SOME ELEVATED CONVECTION.
ALSO...IF THERE IS ENOUGH CLEARING OVER THE MOUNTAINS TO ALLOW FOR
DAY-TIME HEATING INDUCED INSTABILITY...THAT WOULD ALSO HELP
THUNDERSTORMS/SHOWERS TO SPARK OVER THE MOUNTAINS AND DESERTS. WRF
SHOWS THE WINDS ALOFT BEING SOMEWHAT WEAK...WHICH MEANS THE
POSSIBILITY OF SLOW MOVING STORMS AND AN INCREASED FLASH FLOOD
THREAT FOR SATURDAY...BUT THE GFS INDICATES STRONGER WINDS ALOFT AND
FASTER MOVING STORMS. FOR SATURDAY NIGHT INTO SUNDAY MORNING...THE
NAM...WRF AND CANSAC WRF SHOW SCATTERED TO WIDESPREAD PRECIPITATION
OVER THE AREA WITH AN UPPER LEVEL WAVE MOVING OVER THE AREA FROM THE
SOUTH. THE MOISTURE ALSO REACHES THE SURFACE BY THIS TIME ACCORDING
TO MODEL CROSS-SECTIONS. GOING TO SUNDAY AFTERNOON...LOOKS LIKE SOME
OF THE UPPER LEVEL MOISTURE CLEARS OUT...WHICH COULD RESULT IN
BETTER CLEARING OF CLOUDS AND MORE SUNSHINE. THIS WOULD HELP ENHANCE
CHANCES FOR THUNDERSTORMS AND SHOWERS FOR THE MOUNTAINS AND DESERTS
THAT AFTERNOON AND EARLY EVENING...WITH SOUTHWESTERLY FLOW ALOFT
CONTINUING. WINDS ALOFT OF 15-20 KT SHOULD KEEP STORMS MOVING
QUICKLY ENOUGH FOR THERE NOT TO BE A BIG FLASH FLOOD THREAT...WITH
THE FRESH MOUNTAIN BURN SCARS BEING OF BIGGEST CONCERN. FOR
MONDAY...THERE WILL STILL BE ENOUGH MOISTURE AROUND TO PRODUCE A
CHANCE FOR THUNDERSTORMS AND SHOWERS OVER THE MOUNTAINS AND DESERTS
DURING THE AFTERNOON AND EARLY EVENING HOURS.
FOR SUNDAY AND MONDAY...THE CLOSENESS OF THE REMNANT LOW OF DOLORES
COULD CREATE AN OFFSHORE FLOW SCENARIO WHICH COULD HELP TO HEAT UP
THE AREAS WEST OF THE MOUNTAINS. THIS...IN ADDITION TO SURFACE
DEWPOINTS POSSIBLY RISING INTO THE THE UPPER 60S/LOW 70S FOR THE
COAST AND VALLEYS...WILL RESULT IN HOT AND MUGGY CONDITIONS
SUNDAY...AND MONDAY AS WELL. FINALLY...ALL THE MOISTURE IN THE MID-
TO-HIGH LEVELS MAY INHIBIT NIGHT AND MORNING MARINE LAYER LOW
STRATUS/FOG FORMATION...WITH PATCHY LOW CLOUDS AT BEST.
DRY CONDITIONS LOOK TO PREVAIL NEXT TUESDAY THROUGH FRIDAY UNDER
SOUTHWEST FLOW ALOFT AS THE RIDGE GETS NUDGED EAST BY A TROUGH ALONG
THE WEST COAST...WITH DAY-TIME HIGHS SEVERAL DEGREES BELOW NORMAL.
EXPECT THE NIGHT AND MORNING MARINE LAYER CLOUDS TO RETURN FOR THE
COAST AND PORTIONS OF THE VALLEYS.
&&
.AVIATION...
172030Z...COAST/VALLEYS...VFR CONDITIONS THROUGH THIS EVENING.
PATCHY STRATUS...WITH BASES FROM 1500-1800 FT MSL AND TOPS TO 2500
FT MSL...WILL DEVELOP ALONG THE COAST/VALLEYS TONIGHT. HIGH/MID
CLOUDS MOVING INTO THE REGION TONIGHT THROUGH SATURDAY WILL HELP
MAKE THE LOW CLOUDS MORE PATCHY. SHRA/TSRA WILL BEGIN TO DEVELOP
ACROSS THE AREA LATE TOMORROW MORNING AND CONTINUE THROUGH THE END
OF THE WEEKEND. FORECASTER CONFIDENCE IN CLOUD FORECAST IS MODERATE
TO HIGH.
MTNS/DESERTS...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH THIS
EVENING. INCREASING MID/HIGH CLOUDS LATE THIS EVENING THROUGH
SATURDAY MORNING. OCCASIONAL WESTERLY WIND GUSTS TO 40 KT WILL
CREATE MOSTLY MDT UDDFS AND LLWS OVER AND EAST OF THE MTNS...MAINLY
THIS AFTN AND EVENING. CHANCE OF SHRA/TSRA SATURDAY LATE MORNING
THROUGH THE END OF THE WEEKEND.
&&
.MARINE...
130 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH THIS
EVENING. CHANCE OF THUNDERSTORMS SATURDAY THROUGH SUNDAY OVER THE
COASTAL WATERS. GUSTY AND ERRATIC WINDS...CLOUD-TO-WATER LIGHTNING
AND ROUGH SEAS MAY ACCOMPANY ANY THUNDERSTORMS. CONDITIONS WILL
IMPROVE BY SUNDAY NIGHT.
&&
.BEACHES...
130 PM...A 5 FT/11 SEC SOUTHERLY SWELL FROM TROPICAL CYCLONE DOLORES
WILL REACH PARTS OF ORANGE COUNTY AND NORTHERN SAN DIEGO COUNTY
SATURDAY INTO SUNDAY. ELEVATED SURF OF 5 TO 7 FT...WITH ISOLATED
SETS TO 8 FT...WILL BE LIKELY ALONG SOUTH FACING BEACHES OF ORANGE
COUNTY AND NORTHERN SAN DIEGO COUNTY. STRONG RIP CURRENTS ARE
EXPECTED THROUGH THE WEEKEND.
ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE SATURDAY THROUGH
SUNDAY AT THE BEACHES. LIGHTNING...GUSTY AND ERRATIC WINDS...AND
HEAVY DOWNPOURS ARE POSSIBLE WHERE STORMS DEVELOP. A BEACH HAZARDS
STATEMENT IS IN EFFECT THROUGH THE PERIOD.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH MONDAY EVENING
FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL
AREAS.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE/BEACHES...JJT
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
351 PM PDT THU JUL 16 2015
.SYNOPSIS...
GRADUAL COOLING TREND FRIDAY INTO THIS WEEKEND AS DAYTIME HIGHS
BECOME MORE SEASONAL. TROPICAL MOISTURE FROM HURRICANE DOLORES
MAY BRING A THREAT OF SHOWERS EARLY NEXT WEEK MAINLY IN THE
MOUNTAINS.
&&
.DISCUSSION...
THUNDERSTORMS HAVE DEVELOPED OVER THE SIERRA CREST FROM PLUMAS
COUNTY SOUTHWARD. MOST OF THESE CELLS ARE STAYING FAIRLY
STATIONARY NEAR THE CREST THIS AFTERNOON. THE HRRR MODEL INDICATES
THAT THEY SHOULD DRIFT EASTWARD AFTER 7 PM.
AS OF 3 PM VALLEY HIGHS WERE RANGING 93 TO 105. THE SACRAMENTO
METRO REGION IS AROUND 93-95 DEGREES WHILE REDDING IS THE HOT
WINNER AT 105 THIS HOUR. ADDITIONAL HEATING BY A DEGREE OR TWO MAY
OCCUR IN THE NEXT FEW HOURS.
SLIGHT COOLING BEGINS TOMORROW (FRIDAY) AS AN UPPER LEVEL TROUGH
GLANCES FAR NORCAL ON FRIDAY AND SATURDAY. IT MAY EVEN BRING SOME
ISOLATED SHOWERS TO THE MOUNTAINS IN PLUMAS AND SHASTA COUNTIES
FRIDAY NIGHT INTO SATURDAY. OVER THE WEEKEND, DAYTIME HIGHS WILL
BE WITHIN A COUPLE OF DEGREES OF NORMAL.
THE NEXT FOCUS IN WEATHER WILL BE HOW REMNANT MOISTURE FROM
HURRICANE DOLORES COULD MOVE INTO OUR REGION EARLY NEXT WEEK. THE
ECMWF CONTINUES TO BE THE MORE PROGRESSIVE MODEL SHOWING SHOWER
ACTIVITY IN THE SOUTHERN PORTION OF OUR CWA ON SUNDAY AND THEN
SPREADING NORTHWARD ON MONDAY. THE GFS IS STILL A BIT SLOWER AND
SHOWS LESS IMPACT TO OUR AREA. FOR THE SHORT-TERM PERIOD, HAVE
KEPT THE FORECAST TRENDING WITH THE ECMWF WITH HIGHEST PROBABILITY
OF SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS. IF SHOWERS DEVELOP
IN THE VALLEY, THEY WOULD LIKELY STAY SOUTH OF INTERSTATE 80. JBB
&&
.EXTENDED DISCUSSION (MONDAY THROUGH THURSDAY)
SUBTROPICAL MOISTURE WILL BRING THE POTENTIAL FOR MOUNTAIN SHOWERS
AND THUNDERSTORMS ON MONDAY AND TUESDAY. PART OF THIS WILL BE
REMNANTS OF DOLORES. THE BEST POTENTIAL WILL BE ALONG THE CREST,
ESPECIALLY SOUTH OF I80. DRIER SOUTHWEST FLOW IS EXPECTED FOR MID
WEEK, WITH MAINLY DRY WEATHER FOR THE FORECAST AREA. NEAR NORMAL
TEMPERATURES ARE EXPECTED DROPPING TO BELOW NORMAL FOR MID TO
LATE NEXT WEEK AS A FAIRLY DEEP TROUGH APPROACHES. LOOKING OUT
LATE IN THE WEEK, THERE IS THE POTENTIAL FOR SOME SHOWERS OVER
THE NORTHERN MOUNTAINS LATE IN THE WEEK. EK
&&
.AVIATION...
VFR CONDITIONS AT TAF SITES NEXT 24 HOURS. MARINE STRATUS MAY
CAUSE MVFR CIGS INVOF CARQUINEZ STRAIT THRU 18Z. CHANCE OF
AFTERNOON THUNDERSTORMS NEAR SIERRA CREST SOUTH OF LAKE TAHOE.
WINDS GENERALLY UNDER 15 KTS EXCEPT FOR GUSTS UP TO 30 KTS INVOF
OF DELTA.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1139 AM MDT THU JUL 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT THU JUL 16 2015
DRYING AND WARMING TREND IS EXPECTED TODAY AS MONSOON PLUME
SHIFTS EASTWARD. STILL SUFFICIENT RESIDUAL MOISTURE AND AN APPARENT
WEAK WAVE BACK ACROSS ERN UT/WRN CO THAT WILL MOVE ACROSS THE AREA
AND TRIGGER SOME ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS. SFC DEW POINTS DROP BACK INTO THE 30S AND 40S
ACROSS THE MOUNTAINS AND I-25 CORRIDOR TODAY WHICH WILL REALLY LIMIT
CAPE VALUES AND STORM STRENGTHS. MAIN THREAT WITH THUNDERSTORMS FOR
WESTERN PORTIONS OF THE AREA WILL BE LIGHTNING AND GUSTY
WINDS...THOUGH SOME OF THE ISOLATED STRONGER STORMS COULD PRODUCE
SOME MODERATE TO LOCALLY HEAVY RAINFALL. STRONGEST STORMS TODAY
COULD BE ACROSS THE FAR SOUTHEAST CORNER OF THE STATE WHERE AXIS OF
HIGHER DEW POINTS MAY HANG IN. IF DEW POINTS CAN STAY IN THE MID TO
UPPER 50S...THEN CAPE VALUES COULD BE ON THE ORDER OF 1000 J/KG OR A
LITTLE BETTER. GFS...RAP13 AND LATEST RUNS OF THE HRRR ARE TRENDING
DRIER WITH SFC DEW POINTS THOUGH...AND IF THIS OCCURS THEN STORM
STRENGTHS WILL BE LOWER. OTHER HIGH RES MODELS...INCLUDING NMM AND
ARW LEAN TOWARDS THE NAM12. WILL MAINTAIN SOME SLIGHTLY HIGHER POPS
ALONG THE SOUTHERN PORTIONS OF THE FORECAST AREA WHERE CONVERGENCE
ALONG SFC TROF AXIS MAY STILL LINGER. COULD SEE A MARGINALLY STRONG
STORM OR TWO DOWN THAT WAY THIS AFTERNOON. OTHERWISE...TEMPERATURES
WILL WARM A FEW DEGREES OVER THOSE OF YESTERDAY.
THUNDERSTORMS WILL DIMINISH DURING THE EVENING HOURS FOR MOST AREAS
WITH CONVECTIVE DEBRIS CLOUDINESS EXPECTED TO DIMINISH MORE QUICKLY.
THIS WILL RESULT IN LOW TEMPERATURES ON THE COOLER SIDE OF THE
SPECTRUM COMPARED TO RECENT DAYS. -KT
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 500 AM MDT THU JUL 16 2015
NOT MANY CHANGES NEEDING TO EXISTING FORECAST DURING THE LONGER
TERM WITH THE MAIN METEOROLOGICAL ISSUES BEING TEMPERATURES AND
INCREASING PRECIPITATION POTENTIAL(INCLUDING THE POTENTIAL FOR
LOCALLY HEAVY RAIN AS WELL AS STRONG TO POSSIBLY SEVERE STORMS AT
TIMES)...PRIMARILY FROM LATER THIS WEEKEND INTO EARLY NEXT WEEK.
UPPER RIDGE IS STILL EXPECTED TO REMAIN CENTERED OVER NORTHEASTERN
TEXAS INTO EARLY NEXT WEEK ALLOWING DEEPER ATMOSPHERIC MOISTURE
TO CONTINUE OVER MANY SECTIONS OF THE FORECAST DISTRICT DURING
THIS TIME-FRAME. UPPER RIDGE THEN ATTEMPTS TO BUILD WEST TOWARDS
COLORADO BY MIDDLE ON NEXT WEEK.
IN ADDITION...A STRONGER UPPER DISTURBANCE IS STILL EXPECTED TO
IMPACT THE FORECAST DISTRICT BY EARLY NEXT WEEK IN COMBINATION
WITH NORTH TO NORTHEASTERLY SURFACE SURGES MOVING ACROSS EASTERN
SECTIONS FROM THIS WEEKEND INTO EARLY NEXT WEEK.
COOLER TEMPERATURES AS WELL AS INCREASING PRECIPITATION IS
ANTICIPATED FROM LATER THIS WEEKEND INTO EARLY NEXT WEEK. LOCALLY
HEAVY RAINFALL AS WELL AS STRONG TO SEVERE STORMS WILL ALSO BE
POSSIBLE DURING THIS TIME-FRAME...PRIMARILY OVER EASTERN SECTIONS
OF THE CWFA. IN ADDITION...STRONG TO POTENTIALLY SEVERE
THUNDERSTORMS(PRIMARILY OVER EASTERN SECTIONS) RE ANTICIPATED
OVER PORTIONS OF THE FORECAST DISTRICT FROM LATER THIS WEEKEND
INTO EARLY NEXT WEEK.
FINALLY...NEAR TO ABOVE SEASONAL MID TO LATER JULY TEMPERATURES
SHOULD BE NOTED OVER THE MAJORITY OF THE FORECAST DISTRICT FROM
FRIDAY INTO SATURDAY NIGHT WITH BELOW SEASONAL
TEMPERATURES(ESPECIALLY OVER EASTERN SECTIONS) ANTICIPATED FROM
SUNDAY INTO EARLY NEXT WEEK...BEFORE TEMPERATURES BEGIN WARMING
AGAIN BY MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1135 AM MDT THU JUL 16 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES TODAY AND TONIGHT.
TSRA WILL DEVELOP OVER THE MOUNTAINS 18Z-20Z...THEN DRIFT
EASTWARD POTENTIALLY IMPACTING KCOS AND KALS IN THE LATE
AFTERNOON/EARLY EVENING. LOW LEVELS WILL BE FAIRLY DRY...WITH
ERRATIC WIND GUSTS UP TO 40 KTS AND BRIEF RAINFALL THE PRIMARY
STORM THREATS. HAVEN`T INCLUDED A VCTS AT KPUB...THOUGH GUSTY
OUTFLOOW WINDS WILL BE POSSIBLE. THUNDERSTORMS WILL DIMINISH
DURING THE EVENING WITH LIGHT DIURNALLY DRIVEN WINDS EXPECTED
OVERNIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
500 AM MDT THU JUL 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT THU JUL 16 2015
DRYING AND WARMING TREND IS EXPECTED TODAY AS MONSOON PLUME
SHIFTS EASTWARD. STILL SUFFICIENT RESIDUAL MOISTURE AND AN APPARENT
WEAK WAVE BACK ACROSS ERN UT/WRN CO THAT WILL MOVE ACROSS THE AREA
AND TRIGGER SOME ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS. SFC DEW POINTS DROP BACK INTO THE 30S AND 40S
ACROSS THE MOUNTAINS AND I-25 CORRIDOR TODAY WHICH WILL REALLY LIMIT
CAPE VALUES AND STORM STRENGTHS. MAIN THREAT WITH THUNDERSTORMS FOR
WESTERN PORTIONS OF THE AREA WILL BE LIGHTNING AND GUSTY
WINDS...THOUGH SOME OF THE ISOLATED STRONGER STORMS COULD PRODUCE
SOME MODERATE TO LOCALLY HEAVY RAINFALL. STRONGEST STORMS TODAY
COULD BE ACROSS THE FAR SOUTHEAST CORNER OF THE STATE WHERE AXIS OF
HIGHER DEW POINTS MAY HANG IN. IF DEW POINTS CAN STAY IN THE MID TO
UPPER 50S...THEN CAPE VALUES COULD BE ON THE ORDER OF 1000 J/KG OR A
LITTLE BETTER. GFS...RAP13 AND LATEST RUNS OF THE HRRR ARE TRENDING
DRIER WITH SFC DEW POINTS THOUGH...AND IF THIS OCCURS THEN STORM
STRENGTHS WILL BE LOWER. OTHER HIGH RES MODELS...INCLUDING NMM AND
ARW LEAN TOWARDS THE NAM12. WILL MAINTAIN SOME SLIGHTLY HIGHER POPS
ALONG THE SOUTHERN PORTIONS OF THE FORECAST AREA WHERE CONVERGENCE
ALONG SFC TROF AXIS MAY STILL LINGER. COULD SEE A MARGINALLY STRONG
STORM OR TWO DOWN THAT WAY THIS AFTERNOON. OTHERWISE...TEMPERATURES
WILL WARM A FEW DEGREES OVER THOSE OF YESTERDAY.
THUNDERSTORMS WILL DIMINISH DURING THE EVENING HOURS FOR MOST AREAS
WITH CONVECTIVE DEBRIS CLOUDINESS EXPECTED TO DIMINISH MORE QUICKLY.
THIS WILL RESULT IN LOW TEMPERATURES ON THE COOLER SIDE OF THE
SPECTRUM COMPARED TO RECENT DAYS. -KT
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 500 AM MDT THU JUL 16 2015
NOT MANY CHANGES NEEDING TO EXISTING FORECAST DURING THE LONGER
TERM WITH THE MAIN METEOROLOGICAL ISSUES BEING TEMPERATURES AND
INCREASING PRECIPITATION POTENTIAL(INCLUDING THE POTENTIAL FOR
LOCALLY HEAVY RAIN AS WELL AS STRONG TO POSSIBLY SEVERE STORMS AT
TIMES)...PRIMARILY FROM LATER THIS WEEKEND INTO EARLY NEXT WEEK.
UPPER RIDGE IS STILL EXPECTED TO REMAIN CENTERED OVER NORTHEASTERN
TEXAS INTO EARLY NEXT WEEK ALLOWING DEEPER ATMOSPHERIC MOISTURE
TO CONTINUE OVER MANY SECTIONS OF THE FORECAST DISTRICT DURING
THIS TIME-FRAME. UPPER RIDGE THEN ATTEMPTS TO BUILD WEST TOWARDS
COLORADO BY MIDDLE ON NEXT WEEK.
IN ADDITION...A STRONGER UPPER DISTURBANCE IS STILL EXPECTED TO
IMPACT THE FORECAST DISTRICT BY EARLY NEXT WEEK IN COMBINATION
WITH NORTH TO NORTHEASTERLY SURFACE SURGES MOVING ACROSS EASTERN
SECTIONS FROM THIS WEEKEND INTO EARLY NEXT WEEK.
COOLER TEMPERATURES AS WELL AS INCREASING PRECIPITATION IS
ANTICIPATED FROM LATER THIS WEEKEND INTO EARLY NEXT WEEK. LOCALLY
HEAVY RAINFALL AS WELL AS STRONG TO SEVERE STORMS WILL ALSO BE
POSSIBLE DURING THIS TIME-FRAME...PRIMARILY OVER EASTERN SECTIONS
OF THE CWFA. IN ADDITION...STRONG TO POTENTIALLY SEVERE
THUNDERSTORMS(PRIMARILY OVER EASTERN SECTIONS) RE ANTICIPATED
OVER PORTIONS OF THE FORECAST DISTRICT FROM LATER THIS WEEKEND
INTO EARLY NEXT WEEK.
FINALLY...NEAR TO ABOVE SEASONAL MID TO LATER JULY TEMPERATURES
SHOULD BE NOTED OVER THE MAJORITY OF THE FORECAST DISTRICT FROM
FRIDAY INTO SATURDAY NIGHT WITH BELOW SEASONAL
TEMPERATURES(ESPECIALLY OVER EASTERN SECTIONS) ANTICIPATED FROM
SUNDAY INTO EARLY NEXT WEEK...BEFORE TEMPERATURES BEGIN WARMING
AGAIN BY MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 500 AM MDT THU JUL 16 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES TODAY. THUNDERSTORMS
WILL DEVELOP OVER THE MOUNTAINS AROUND 18Z...THEN DRIFT EASTWARD
POTENTIALLY AFFECTING THE KCOS AND KALS TERMINALS IN THE LATE
AFTERNOON/EARLY EVENING. WITH THUNDERSTORM COVERAGE EXPECTED TO BE
LESS THAN YESTERDAY...WILL LIMIT MENTION OF VCTS TO JUST KALS AND
KCOS FOR NOW...THOUGH THERE WILL BE ISOLATED STORMS DRIFTING
EASTWARD ON THE PLAINS THROUGH THE EVENING HOURS. ERRATIC WIND
GUSTS UP TO 40 KTS AND BRIEF RAINFALL WILL BE THE PRIMARY STORM
THREATS. THUNDERSTORMS WILL DIMINISH DURING THE EVENING WITH LIGHT
DIURNALLY DRIVEN WINDS EXPECTED OVERNIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
239 AM MDT THU JUL 16 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 238 AM MDT THU JUL 16 2015
THE FLOW ALOFT WILL REMAIN WLY TODAY THRU TONIGHT. WATER VAPOR
SHOWS SOME DRIER AIR MOVING INTO WRN CO WHICH WILL MOVE ACROSS THE
AREA DURING THE DAY. THIS IS ALREADY SHOWING UP IN THE IPW SENSORS
WHICH HAVE DROPPED AROUND A QUARTER INCH IN THE LAST 6 HOURS.
HOWEVER THERE WILL STILL BE ENOUGH MOISTURE AROUND FOR ISOLD TO
WDLY SCT STORMS OVER THE HIGHER TERRAIN THIS AFTN. OUTFLOW
BOUNDARIES FM THESE STORMS MAY EVENTUALLY TRIGGER SOME ISOLD
ACTIVITY OVER NERN CO AS WELL THRU THE AFTN HOURS INTO THE EARLY
EVENING. WITH LESS CAPE THIS AFTN STORMS SHOULD NOT BE AS STG AS
YESTERDAY. AS FOR HIGHS 850-700 TEMPS RISE A FEW DEGREES TODAY SO
EXPECT READINGS IN THE UPPER 80S TO MID 90S ACROSS NERN CO.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 238 AM MDT THU JUL 16 2015
STORMS BECOME ISOLATED TO THE HIGHER TERRAIN TOWARD THE END OF THE
WEEK BUT INCREASE OVER THE PLAINS FOR THE START OF NEXT WEEK AS
SUBTROPICAL MOISTURE RETURNS TO THE STATE.
THURSDAY NIGHT INTO EARLY SUNDAY A LARGE HIGH PRESSURE SYSTEM SITS
OVER MUCH OF THE SOUTHERN PORTIONS OF THE CONUS WHILE A LOW PRESSURE
SYSTEM STRENGTHENS OVER CANADA AND THE PACIFIC NW. THIS LOW PRESSURE
SYSTEM WILL DIP AN UPPER TROUGH SOUTH TOWARD THE REGION OVER THE
WEEKEND. THIS PATTERN WILL BRING WEST TO SW UPPER LEVEL FLOW OVER
THE STATE. MOISTURE LEVELS WILL DECREASE SLIGHTLY WITH THE WESTERLY
EXTENSION OF THE RIDGE. THIS WILL HELP TO DECREASE STORM COVERAGE
FOR THE LATTER HALF OF THE WEEK. HOWEVER OVER THE HIGHER TERRAIN
WITH THE HELP OF OROGRAPHICS ALONG WITH LINGERING MOISTURE WILL HELP
TO CONTINUE AFTERNOON CONVECTION IN THE MOUNTAINS AND PORTIONS OF
THE PALMER DIVIDE. HIGH TEMPERATURES FOR FRIDAY WILL BE IN THE MID
90S WITH UPPER 80S EXPECTED FOR SATURDAY. SATURDAY WILL BRING
ANOTHER CHANCE FOR SOME SCATTERED THUNDERSTORMS OVER THE MOUNTAINS
AND ISOLATED OVER THE EASTERN PLAINS. MAIN THREATS WILL BE GUSTY
WINDS WITH BRIEF MODERATE TO HEAVY RAIN.
SUNDAY INTO MONDAY SHOW MODELS BRINGING THE COLD FRONT SOUTH WITH
THE EXTENSION OF THE UPPER LEVEL TROUGH SUNDAY MORNING. MOISTURE AND
FAVORABLE UPSLOPE NE FLOW DEEPENS OVER THE NE BY 12Z SUNDAY
INCREASING STORM COVERAGE. TEMPERATURES FOR SUNDAY WILL BE COOLER
THAN PREVIOUS DAYS WITH HIGHS IN THE UPPER 70S TO LOWER 80S. STORMS
COULD PRODUCE MODERATE TO HEAVY RAIN AS PW VALUES ARE OVER AN INCH
WITH THE RETURN OF SUBTROPICAL MOISTURE ALONG WITH SOME HAIL. SHEAR
VALUES ARE MODERATE IN THE 40S WITH DECENT CAPE SO CANNOT RULE OUT
THE POTENTIAL FOR SEVERE AT THIS POINT FOR SUNDAY AFTERNOON IF
ENOUGH HEATING IS PROVIDED. FOR MONDAY AS THE RIDGE PUSHES NORTH MID
LEVEL STABILITY WILL HELP TO KEEP STORMS ISOLATED WITH INCREASING
TEMPERATURES BACK INTO THE UPPER 80S. INCREASED COVERAGE WILL REMAIN
OVER THE HIGHER TERRAIN WITH OROGRAPHIC EFFECTS.
FOR TUESDAY AND WEDNESDAY THE UPPER LEVEL RIDGE CONTINUE TO PUSH
NORTH BRINGING DRIER AND WARMER CONDITIONS TO THE REGION. LINGERING
MOISTURE WILL STILL ALLOW FOR DIURNAL THUNDERSTORM DEVELOPMENT IN
THE AFTERNOON OVER THE MOUNTAINS WITH LITTLE MOVEMENT OVER THE
PLAINS GIVEN THE ADDED STABILITY. TEMPERATURES WILL BE AROUND NORMAL
WITH HIGHS IN THE UPPER 80S.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 238 AM MDT THU JUL 16 2015
WINDS WERE DRAINAGE EARLY THIS MORNING AND BOTH THE RAP AND HRRR
KEEP THEM LIGHT S TO SSW THRU 18Z. BY MID TO LATE AFTN THERE WILL
PROBABLY BE A WIND SHIFT TO MORE WLY AS OUTFLOW BOUNDARIES FM HIGH
BASED CONVECTION OVER THE HIGHER TERRAIN MOVE ACROSS. THERE COULD
BE AN ISOLD TSTM OR TWO ALONG THE BNDRY HOWEVER DO NOT EXPECT A
REPEAT OF YESTERDAY SO WILL JUST MENTION VCTS IN THE TAF. FOR THIS
EVENING TSTM THREAT SHOULD END BY 02Z. AS FOR WINDS THEY SHOULD
TREND BACK TO DRAINAGE BY 03Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...BOWEN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1027 AM EDT THU JUL 16 2015
.SYNOPSIS...
HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES THROUGH TONIGHT. THE
HIGH MOVES OFFSHORE ON FRIDAY. A WARM FRONT WILL APPROACH FRIDAY
NIGHT AND PUSH THROUGH DURING SATURDAY. A TROUGH OF LOW PRESSURE
WILL REMAIN OVER THE REGION THROUGH THE WEEKEND. A COLD FRONT THEN
APPROACHES MONDAY AND PASSES THROUGH DURING THE AFTERNOON AND
NIGHTTIME HOURS. WEAK HIGH PRESSURE FOLLOWS FOR THE MID WEEK
PERIOD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST ON TRACK. WIND FIELDS WERE ADJUSTED WITH HRRR AND LAMP
DATA TO DEPICT AFTERNOON SEA BREEZE. TIMING THOUGHT IS PROBABLY
TOO FAST.
OTHERWISE...STRONG 1018 MB HIGH OVER LAKE HURON WILL SLOWLY TRACK
TO THE EAST TODAY. SFC DEWPOINTS IN THE UPPER 40S/LOWER 50S UNDER
CLEAR SKIES. HIGHS IN THE UPPER 70S TO LOWER 80S...WITH THE
WARMEST TEMPS ACROSS NYC/NORTHEAST NJ AND ACROSS PORTIONS OF
INTERIOR CT.
THERE IS A MODERATE RISK FOR RIP CURRENTS AT OCEAN BEACHES TODAY.
WAVES STILL AT 5 FT FROM THE BUOY JUST OFFSHORE FIRE ISLAND
(44094). SOME UPWELLING FROM THE NORTH WINDS HAS LOWERED SST`S
INTO THE UPPER 60S AT THE OCEAN BEACHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WITH THE CENTER OF THE HIGH PASSING FROM NORTHERN NY STATE TO
CAPE COD TONIGHT...CAN EXPECT CLEAR SKIES AND LIGHT WINDS. THE
URBAN HEAT ISLAND EFFECT WILL RESULT IN LOWS IN THE UPPER 60S
ACROSS NYC AND PORTIONS OF NORTHEAST NJ...WHILE MOST OF THE CWA
WILL DROP INTO THE LOW 60S. STRONG RADIATIONAL COOLING CONDS WILL
DEVELOP ACROSS OUTLYING PORTIONS OF THE LOWER HUDSON
VALLEY...INTERIOR PORTIONS OF SOUTHERN CT...AND THE PINE BARRENS
OF LONG ISLAND...WHERE LOWS WILL DROP INTO THE LOW 50S.
RETURN FLOW DEVELOPS ON FRIDAY AS HIGH PRES MOVES OFFSHORE AND A
COLD FRONT APPROACHES FROM THE WEST. HUMIDITY LEVELS WILL BEGIN TO
CREEP UP AS SFC DEWPOINTS APPROACH 60. HIGHS WILL BE A FEW DEGREES
SHY OF NORMAL FOR THIS TIME OF THE YEAR...TOPPING OFF IN THE UPPER
70S TO LOWER 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WARM FRONT APPROACHES FRIDAY NIGHT...BRINGING THE CHANCE OF
SHOWERS TO MOST OF THE REGION...BUT FOCUSED MORE TOWARD THE LATE
NIGHT HOURS.
THE WARM FRONT LIFTS DURING SATURDAY. WE DESTABILIZE...AND WITH A
TROUGH RUNNING THROUGH THE CWA...SOME MOISTURE CONVERGENCE AND
CAPE PROBABLY PRODUCES SCATTERED SHOWERS AND THUNDERSTORMS. SOME
STORMS COULD BE STRONG AS THE WIND PROFILE VEERS WITH HEIGHT...BUT
A LIMITING FACTOR FOR SEVERE STORMS IS WEAK SPEED SHEAR/MARGINAL
WIND SPEEDS ALOFT. AN INVERTED-V PROFILE IN THE LOW LEVELS
ALTHOUGH COULD HELP PRODUCE A STRONG GUST OR TWO. MAV/NAM MOS
BLEND LOOKED GOOD FOR HIGHS.
SUNDAY APPEARS TO BE SIMILAR TO SUNDAY WITH THE SETUP. THE TROUGH
REMAINS IN A SIMILAR POSITION...BUT QPF FIELDS WOULD SUGGEST A
BETTER CHANCE OF SHOWERS/STORMS FOR THE NW HALF OF THE
CWA...CLOSER TO THE TROUGH WHERE MOISTURE CONVERGENCE WOULD BE
BEST. WILL THEREFORE LIMIT POPS TO SLIGHT CHC FOR LONG ISLAND AND
SE CT.
FOR MONDAY AND MONDAY NIGHT...THE TROUGH AND TRAILING COLD FRONT
WILL SERVE AS FOCUSES FOR STORM DEVELOPMENT. CAPE AND SHEAR ARE
SUFFICIENT FOR STRONG TO POTENTIALLY SEVERE STORMS. THE LIMITING
FACTOR FOR SEVERE APPEARS TO BE THE POTENTIAL FOR BKN-OVC SKY
CONDS...HOLDING BACK CAPE. IF THERE ARE FEWER CLOUDS THAN
CURRENTLY FORECAST...CAPE COULD BE RATHER SIGNIFICANT WITH SEVERE
STORMS A MUCH GREATER CONCERN. HIGH TEMPS COULD ALSO END UP A FEW
DEGREES WARMER THAN CURRENTLY FORECAST AS MODELS SHOW 850 TEMPS
INCREASING TO 18-19C. HEAT INDICES WOULD ALSO THEREFORE CLIMB INTO
THE MID AND UPPER 90S FOR SOME SPOTS.
MODEL CONSENSUS HAS THE COLD FRONT TO THE EAST BY TUESDAY MORNING
AND WEAK HIGH PRESSURE LIKELY KEEPING US DRY FOR TUESDAY AND
WEDNESDAY. HIGHS MOSTLY IN THE MID AND UPPER 80S BOTH DAYS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE BUILDS INTO THE REGION WITH VFR THROUGH THE TAF
PERIOD.
N-NNE FLOW GUSTING TO NEAR 20 KT DIMINISHES THIS AFTERNOON TO
AROUND 10 KT OR LESS. A VEERING OF WINDS TO SE-S FLOW OCCURS THIS
AFTERNOON AS SEA BREEZES DEVELOP AND MOVE IN FOR COASTAL 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: GUSTS MAY BE OCCASIONAL THIS AFTERNOON.
TIMING OF SOUTHERLY WINDS MAY OFF BY 1-2 HOURS.
KLGA FCSTER COMMENTS: GUSTS MAY BE OCCASIONAL THIS AFTERNOON.
TIMING OF SOUTHERLY WINDS MAY OFF BY 1-2 HOURS.
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS POSSIBLE THIS AFTERNOON.
TIMING OF SOUTHERLY WINDS MAY OFF BY 1-2 HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS POSSIBLE THIS AFTERNOON.
TIMING OF SOUTHERLY WINDS MAY OFF BY 1-2 HOURS.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS POSSIBLE THIS AFTERNOON.
TIMING OF SOUTHERLY WINDS MAY OFF BY 1-2 HOURS.
KISP FCSTER COMMENTS: GUSTS MAY BE OCCASIONAL THIS AFTERNOON.
TIMING OF SOUTHERLY WINDS MAY OFF BY 1-2 HOURS.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRI...VFR.
.SAT-MON...MVFR OR LOWER POSSIBLE IN SCT SHRA/TSRA.
&&
.MARINE...
SMALL CRAFT ADVISORY CONDS WILL CONTINUE ON THE OCEAN WATERS INTO
THIS EVENING. 25 KT WIND GUSTS WILL DIMINISH SHORTLY...BUT SEAS
WILL REMAIN ELEVATED AT 4-6 FT ON THE OCEAN THROUGH THE AFTERNOON
BEFORE SUBSIDING BELOW SCA CRITERIA THIS EVENING.
SUB-SCA CONDS ON TAP FOR FRIDAY AS HIGH PRES PASSES NORTH OF THE
WATERS.
QUIET WITH RESPECT TO PREVAILING WINDS/SEAS FROM FRI NIGHT
THROUGH MON NIGHT. TSTMS COULD POSE LOCAL HAZARDS ON SAT.
&&
.HYDROLOGY...
NO HYDROLOGIC PROBLEMS THROUGH FRIDAY NIGHT WITH DRY WEATHER
FORECAST.
TSTMS SAT AFTERNOON THROUGH MON NIGHT COULD PRODUCE LOCALLY HEAVY
RAINFALL.
&&
.EQUIPMENT...
NOAA WEATHER RADIO WEEKLY TEST WILL BE CONDUCTED TODAY AT 11AM.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...JC/MPS
NEAR TERM...TONGUE
SHORT TERM...MPS
LONG TERM...JC
AVIATION...BC/JM
MARINE...JC/MPS
HYDROLOGY...JC/MPS
EQUIPMENT...JM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
343 PM EDT THU JUL 16 2015
.DISCUSSION...
CURRENTLY-TONIGHT...QUITE A BIT OF THE AREA HAS HAD A
SHOWER/STORM/OUTFLOW BOUNDARY. HOWEVER...THE EARLIER ONSET TODAY
WILL ALLOW FOR OUTFLOW BOUNDARIES TO GENERATE ADDITIONAL STORMS
THROUGH EARLY EVENING WHERE POCKETS OF INSTABILITY WILL LINGER.
THE LATEST HRRR SHOWS SOME RAINFALL INTO LATE EVENING...WITH
EMBEDDED THUNDER...FROM BREVARD TO OKEECHOBEE AND THE TREASURE
COAST. MOS POPS ARE AROUND 50 PERCENT THERE...SO WILL KEEP CHANCE
POPS UNTIL LATE EVENING WITH SLIGHT CHANCE ELSEWHERE. NO RAINFALL
IS EXPECTED OVERNIGHT.
FRI-SAT...PERSISTENT WET PATTERN INTO THE WEEKEND AS A DEEP
FRONTAL TROF EXTENDING FROM HUDSON BAY TO THE NORTHEAST GULF OF
MEXICO DRIFTS SEAWARD AND KEEPS THE ATLANTIC RIDGE AXIS SUPPRESSED
OVER SOUTH FLORIDA. WEST/SOUTHWEST FLOW WILL PREVAIL THROUGH THE
1000-700 MB LAYER...PINNING THE EAST COAST SEA BREEZE OVER THE
COASTAL COUNTIES WHERE IT WILL BE THE FOCUS FOR SCATTERED/NUMEROUS
SHOWERS AND STORMS. MEANWHILE...AN 850-300 MB ANTICYCLONE WILL
PUSH ACROSS THE LOWER MISSISSIPPI VALLEY AND NUDGE ITS WAY INTO
THE DEEP SOUTH...INTERACTING WITH THE FRONTAL TROF TO PROVIDE A
NORTH NORTHEAST FLOW ABV 500 MB.
THE MID/UPPER LEVEL WINDS WILL TAP AN AIRMASS OVER THE DEEP SOUTH
WITH RATHER WARM MID LEVEL TEMPS...RESULTING IN 700 MB TEMPS
EXPECTED TO WARM TO AROUND 9C WITH 500 MB TEMPS HOVERING AROUND
-6C. THE RESULTING LAPSE RATES BETWEEN 5.0-6.0C/KM THRU THE LAYER
WILL LIMIT OVERALL STORM POTENTIAL. EVEN SO...PRECIP CHANCES WILL
BE 50-60PCT AREAWIDE AS A PREFRONTAL MOISTURE BAND SETS UP ACROSS
CENTRAL FL AND KEEPS PWATS AT OR ABOVE 2.0". STORMS WILL GENERATE
LOCAL HEAVY RAIN AS THE 850-500 MB STEERING FLOW...ALREADY
WEAKENED BY THE DEEP FRONTAL TROF...REMAINS LARGELY AT OR BELOW 10KTS.
THE WEST/SOUTHWEST FLOW WILL KEEP MAX TEMPS AT OR ABOVE CLIMO WITH
AFTERNOON READINGS IN THE LOWER-MID 90S. SURFACE DEW POINTS IN
THE LOWER-MID 70S WILL KEEP MIN TEMPS ABOUT HALF A CATEGORY
HIGHER (MID-UPPER 70S).
SUN-THU...STAGNANT WEATHER PATTERN INTO THE MIDDLE OF NEXT WEEK
AS A WEAK REFLECTION OF THE FRONTAL TROF PERSISTS OFF THE
SOUTHEAST COAST AND PREVENTS THE ATLANTIC RIDGE AXIS FROM LINKING
UP WITH THE ANTICYCLONE OVER THE DEEP SOUTH. THE RESULTING COL
WILL KEEP MEAN WINDS THROUGH THE COLUMN AT OR BELOW 10 KNOTS...WITH
WEST/SOUTHWEST FLOW PERSISTING THROUGH THE 1000-700 MB LAYER. DEEP
MOISTURE WILL REMAIN TRAPPED BELOW THE COL WHILE THE ATLANTIC
RIDGE AXIS REMAINS SUPPRESSED SOUTH OF THE I-4 CORRIDOR.
THE WEAK ENVIRONMENTAL FLOW WILL ALLOW BOTH EAST AND WEST COAST
SEA BREEZES TO FORM BY MIDDAY AND PUSH WELL INLAND. THE LIGHT
WESTERLY FLOW THROUGH THE 1000-700 MB LAYER WILL ALLOW STORMS TO
CONCENTRATE OVER THE EAST FLORIDA PENINSULA...THOUGH THE WEAK
STEERING WINDS SHOULD KEEP COVERAGE AT OR BELOW 50 PERCENT. TEMPS
NEAR OR SLIGHTLY ABOVE AVERAGE FOR MID SUMMER.
&&
.AVIATION...
THE QUITE EARLY ONSET OF CONVECTION SHOULD LEAD TO A WORKED OVER
ATMOSPHERE BY SUNSET...SO WE ARE EXPECTING STRONG STORMS TO BE OVER
BY THEN. SOME LINGERING STRATIFORM RAIN WITH EMBEDDED LIGHTNING
STRIKES MAY PERSIST A LITTLE AFTER DARK FROM TIX-MLB SOUTHWARD TO
SUA. THEN THE OVERNIGHT PERIOD WILL BE MAINLY VFR.
A VERY MOIST AIR MASS ON FRI WILL LEAD TO EARLY ONSET OF CONVECTION
AGAIN. THE WEST TO EAST STEERING FLOW MAY BE A LITTLE WEAKER...
PUSHING BACK THE ONSET TIME SLIGHTLY OVER THE INTERIOR. A SEA
BREEZE COULD ALSO FORM AND BE PINNED CLOSE TO THE COAST...SO STORM
INTENSITY MAY INCREASE A NOTCH FOR THE COASTAL TERMINALS.
&&
.MARINE...
TONIGHT-FRI...SURFACE RIDGE AXIS WILL STAY SOUTH OF THE WATERS BUT
OVERALL THE PRESSURE GRADIENT SHOULD EASE AS FRONTAL TROUGH TO
THE NORTH WEAKENS. SOUTHWEST FLOW SHOULD BE NEAR 15 KNOTS OFFSHORE
TONIGHT BUT THEN DECREASE TO 10 KNOTS ON FRI. THE MAIN ISSUE FOR
MARINERS WILL CONTINUE TO BE OFFSHORE MOVING STORMS...MAINLY IN
THE AFTERNOON...BUT A FEW COULD AFFECT COASTAL SECTIONS LATE IN
THE MORNING TOO.
WEEKEND-TUE...LITTLE CHANGE IN THE MOIST PATTERN WITH SURFACE
RIDGE AXIS STAYING QUASI STEADY STATE JUST SOUTH OF THE WATERS.
THIS WILL MAINTAIN THE SOUTHWEST WIND FLOW REGIME. SPEEDS WILL BE
MAINLY 10 KNOTS OR LESS THIS WEEKEND...SO THERE SHOULD BE A SEA
BREEZE DEVELOPING. WITH THE MOIST AIR MASS...THIS WILL LIKELY
LEAD TO STRONG BOUNDARY INTERACTIONS IN THE AFTERNOON WITH A
CONTINUATION OF OUR DAILY SPECIAL MARINE WARNINGS FOR STRONG
STORMS. THE PRESSURE GRADIENT IS SHOWN TIGHTENING UP A BIT MON-
TUE WITH SOUTHWEST WINDS CLOSE TO 15 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 75 91 74 91 / 30 60 30 50
MCO 75 92 75 93 / 20 60 30 60
MLB 74 92 75 91 / 40 60 40 60
VRB 74 92 73 91 / 40 60 40 60
LEE 76 90 77 92 / 20 60 30 50
SFB 76 92 75 92 / 20 60 30 60
ORL 76 92 76 92 / 20 60 30 60
FPR 72 91 73 91 / 40 60 40 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...SEDLOCK
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
921 AM EDT THU JUL 16 2015
.DISCUSSION...
TODAY...MORNING CANAVERAL SOUNDING AND GPS DATA SHOW PRECIPITABLE
WATER VALUES AROUND 2 INCHES. THERE WERE ALREADY SCATTERED SHOWERS
AND ISOLATED STORMS ALONG AND JUST INLAND OF THE WEST COAST.
SOUNDING DATA AND RAP ANALYSIS SHOW MID LEVEL TEMPS HAVE WARMED TO
AROUND MINUS 6 CELSIUS. HOWEVER...WATER VAPOR SHOWS SOME MID LEVEL
DRYING HAS WORKED DOWN INTO NORTHERN SECTIONS AND WAS ERODING CLOUD
DECK ACROSS THE SOUTH. THE COMBINATION OF VERY MOIST LOW LEVELS AND
DRIER MID LEVEL AIR WILL KEEP POTENTIAL CONVECTIVE INSTABILITY
ELEVATED. THE FLOW IN THE LOW LEVELS WILL BE TOO GREAT TO ALLOW A
SEA BREEZE...BUT LOCALIZED OUTFLOW BOUNDARY INTERACTIONS SHOULD
GENERATE A FEW STRONG STORMS AGAIN. THE MAIN HAZARD WILL BE FROM
STRONG WIND GUSTS AND BRIEF BURSTS OF FREQUENT LIGHTNING STRIKES IN
THE MORE INTENSE STORMS.
AFTER LOOKING AT THE HRRR/LOCAL WRF MODELS...AND WITH THE POTENTIAL
FOR GUSTY OUTFLOW WINDS...THINK THAT OUR CURRENT FORECAST SHOWING
50 PERCENT RAIN CHANCES ACROSS THE NORTH INTERIOR AND AROUND 60
PERCENT ELSEWHERE STILL LOOKS REASONABLE.
&&
.AVIATION...NO CHANGE TO PREVIOUS THINKING
W/SW FLOW WILL PERSIST TODAY WITH SCT TO NMRS TSRA DEVELOPING THIS
AFTN WITH THE GREATEST COVERAGE NEAR THE COAST SOUTH OF THE CAPE
EXPECTED. STRONG DOWNBURST WINDS 35 TO 45 KNOTS WILL BE THE PRIMARY
THREAT WITH FREQUENT LIGHTNING STRIKES. INCLUDED 2HR TEMPO GROUPS
FOR MVFR CONDS IN TSRA RANGING FROM 16Z-20Z AT ALL TERMINALS.
SOUTHERN TERMINALS (MLB-SUA) MAY SEE PREVAILING RA WITH VCTS INTO
THE EARLY EVENING...THEN VFR.
&&
.MARINE...
TODAY...NO CHANGE TO PREVIOUS THINKING
WEST TO SOUTHWEST FLOW 10-15 KNOTS WILL CONTINUE. SEAS NEAR THE
COAST AROUND 1 FT AND UP TO 3 FT WELL OFFSHORE WITH A BIT OF A WIND
CHOP. THE PRIMARY CONCERN WILL BE SCATTERED TO NUMEROUS LIGHTNING
STORMS PUSHING OFFSHORE DURING THE AFTN. COVERAGE LOOKS HIGHER FROM
THE CAPE SOUTHWARD BUT ANY STORM WILL BE CAPABLE OF PRODUCING WIND
GUSTS OF 35 TO 45 KNOTS SO ONE OR MORE SPECIAL MARINE WARNINGS WILL
PROBABLY BE ISSUED FOR PORTIONS OF THE INTRACOASTAL AND ADJ ATLC
WATERS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...SEDLOCK
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
716 AM EDT THU JUL 16 2015
.Aviation...
[Through 12Z Friday] The forecast reasoning from earlier this
morning largely still holds true. In general, VFR conditions will
prevail other than IFR visibilities in and near thunderstorms.
Some storms could have gusty winds over 30 knots. The terminals
most likely to be impacted would be ECP and TLH, anytime prior to
00Z. DHN and VLD may be affected as well, but that would be more
likely in the afternoon hours. Isolated storms are possible near
Albany, but the lower chances preclude a mention of VCTS in the
TAF at this time.
&&
.Prev Discussion [430 AM EDT]...
.Near Term [Through Today]...
It looks like another day with fairly high convective coverage, this
time across the southern half of the area and the coastal waters of
the Gulf of Mexico. There are already signs of renewed convective
initiation near the coastline of Taylor and Dixie Counties in the
Florida Big Bend at 08Z. This is occurring in a region of enhanced 0-
2km moisture flux convergence per RAP analysis, and that area of
convergence is expected to persist over the next several hours into
the mid-morning. Convection-allowing models (CAM) are almost
unanimous in developing widespread convection between 10Z and 15Z,
generally south of a Panama City to Madison FL line. This is the
area we have inserted 60-80% PoPs for the early-mid morning. After
that, additional convective development should occur along sea-
breeze boundaries and around the periphery of any convective cloud
shield lingering from the morning hours. Showers and storms should
be more isolated across the northern half of our area.
One concern with the morning round of storms in the coastal Big Bend
and Panhandle is localized very heavy rainfall and possible flash
flooding. Our local ensemble of CAMs has several members producing
over 6" of rain in a 6-hr period (or less) this morning. The average
QPF in Gulf, Franklin, and Dixie Counties is as high as 2".
Regarding the possibility of higher-end amounts, the derived
neighborhood probability (for today) of over 6" of rain from the
ensemble in the coastal Florida Panhandle and Big Bend is around
30%. With 6-hour flash flood guidance from SERFC around 5-6", we
felt there was enough of a chance of flash flooding to warrant a
Flash Flood Watch for those areas. Outside of the flash flooding
threat, there will be the possibility for some isolated severe
storms again today - particularly in our Florida zones that can
receive more substantial heating in the morning and early
afternoon.
.Short Term [Tonight Through Saturday]...
The trough along the U.S. East Coast will lift away to the east
allowing the ridge over Texas to build back to the east. This
should reduce the chances for organized MCSs to organize and work
their way southward into the forecast area. We will still be
dealing with a very unstable air mass south of the cold front
which should stall across the northernmost portions of the
forecast area tonight and then gradually dissipate. Evening PoPs
will be much higher well south of the front across the coastal FL
zones where the flash flood watch will be maintained into the
overnight hours. For Friday and Saturday, we will settle back into
a more typical summer pattern with scattered mainly afternoon and
evening thunderstorms, a few of which could reach strong to
marginally severe limits. Temps will generally be 2-5 degrees
above normal.
.Long Term [Saturday Night Through Thursday]...
The upper ridge over the Lower Mississippi Valley will wobble back
to the west over Texas by Monday as some short wave energy begins
to move off the Mid Atlantic coast. This may open up the
possibility for northwest flow to become re-established by then,
but at this time it does not look very pronounced. A surface
trough will be over or near the forecast area for much of the
period. PoPs will be near climo (40-50%) through the period. Temps
will remain above normal.
.Marine...
The pressure gradient across the northeastern Gulf of Mexico will
remain tighter than is typical for mid summer. The result will be
a continuation of WSW winds around 15 knots through tonight.
Conditions will be unsettled over the waters during this time with
a few rounds of strong to severe storms possible. By Friday, winds
will finally drop back to seasonal speeds with daily enhancements
each afternoon and evening in the sea breeze through the weekend
and into next week.
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days across the area.
.Hydrology...
There will be the potential for localized very heavy rainfall today,
and possibly again late tonight and into early Friday, across parts
of the Florida Panhandle and Big Bend. The greatest chance for
rainfall amounts exceeding 6 inches through Friday would be in the
lower portions of river basins (closer to the Gulf of Mexico).
Therefore, the threat of widespread river flooding is not
particularly high, but some smaller streams in the Florida
Panhandle, and perhaps rivers such as the Steinhatchee River and
Econfina River in the Florida Big Bend could be affected. The main
threat from the localized heavy rainfall would be flash flooding of
urban or low lying areas.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 92 75 95 76 95 / 60 30 40 30 40
Panama City 87 80 90 80 90 / 60 30 40 30 40
Dothan 95 76 97 76 97 / 50 20 30 20 30
Albany 95 75 96 75 95 / 30 20 30 20 30
Valdosta 93 74 95 74 95 / 70 30 40 30 40
Cross City 88 75 92 74 93 / 80 60 50 30 50
Apalachicola 89 79 92 79 92 / 80 40 40 40 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...FLASH FLOOD WATCH through Friday morning FOR Calhoun-Coastal Bay-
Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal
Jefferson-Coastal Taylor-Coastal Wakulla-Inland Bay-Inland
Dixie-Inland Franklin-Inland Gulf-Inland Taylor-Inland
Wakulla-Lafayette-Liberty.
HIGH RIP CURRENT RISK through late tonight FOR Coastal Bay-
Coastal Gulf.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
430 AM EDT THU JUL 16 2015
.Near Term [Through Today]...
It looks like another day with fairly high convective coverage, this
time across the southern half of the area and the coastal waters of
the Gulf of Mexico. There are already signs of renewed convective
initiation near the coastline of Taylor and Dixie Counties in the
Florida Big Bend at 08Z. This is occurring in a region of enhanced 0-
2km moisture flux convergence per RAP analysis, and that area of
convergence is expected to persist over the next several hours into
the mid-morning. Convection-allowing models (CAM) are almost
unanimous in developing widespread convection between 10Z and 15Z,
generally south of a Panama City to Madison FL line. This is the
area we have inserted 60-80% PoPs for the early-mid morning. After
that, additional convective development should occur along sea-
breeze boundaries and around the periphery of any convective cloud
shield lingering from the morning hours. Showers and storms should
be more isolated across the northern half of our area.
One concern with the morning round of storms in the coastal Big Bend
and Panhandle is localized very heavy rainfall and possible flash
flooding. Our local ensemble of CAMs has several members producing
over 6" of rain in a 6-hr period (or less) this morning. The average
QPF in Gulf, Franklin, and Dixie Counties is as high as 2".
Regarding the possibility of higher-end amounts, the derived
neighborhood probability (for today) of over 6" of rain from the
ensemble in the coastal Florida Panhandle and Big Bend is around
30%. With 6-hour flash flood guidance from SERFC around 5-6", we
felt there was enough of a chance of flash flooding to warrant a
Flash Flood Watch for those areas. Outside of the flash flooding
threat, there will be the possibility for some isolated severe
storms again today - particularly in our Florida zones that can
receive more substantial heating in the morning and early
afternoon.
.Short Term [Tonight Through Saturday]...
The trough along the U.S. East Coast will lift away to the east
allowing the ridge over Texas to build back to the east. This
should reduce the chances for organized MCSs to organize and work
their way southward into the forecast area. We will still be
dealing with a very unstable air mass south of the cold front
which should stall across the northernmost portions of the
forecast area tonight and then gradually dissipate. Evening PoPs
will be much higher well south of the front across the coastal FL
zones where the flash flood watch will be maintained into the
overnight hours. For Friday and Saturday, we will settle back into
a more typical summer pattern with scattered mainly afternoon and
evening thunderstorms, a few of which could reach strong to
marginally severe limits. Temps will generally be 2-5 degrees
above normal.
.Long Term [Saturday Night Through Thursday]...
The upper ridge over the Lower Mississippi Valley will wobble back
to the west over Texas by Monday as some short wave energy begins
to move off the Mid Atlantic coast. This may open up the
possibility for northwest flow to become re-established by then,
but at this time it does not look very pronounced. A surface
trough will be over or near the forecast area for much of the
period. PoPs will be near climo (40-50%) through the period. Temps
will remain above normal.
&&
.Aviation...
[Through 06Z Friday] In general, VFR conditions will prevail,
although scattered thunderstorms are expected across the area once
again. Visibility in and near storms may be reduced to IFR levels,
and some storms could have gusty winds over 30 knots. The
terminals most likely to be impacted would be ECP and TLH, from
anytime after 12Z through approximately 00Z. DHN and VLD may be
affected as well, but that would be more likely in the afternoon
hours. Isolated storms are possible near Albany, but the lower
chances preclude a mention of VCTS in the TAF at this time.
&&
.Marine...
The pressure gradient across the northeastern Gulf of Mexico will
remain tighter than is typical for mid summer. The result will be
a continuation of WSW winds around 15 knots through tonight.
Conditions will be unsettled over the waters during this time with
a few rounds of strong to severe storms possible. By Friday, winds
will finally drop back to seasonal speeds with daily enhancements
each afternoon and evening in the sea breeze through the weekend
and into next week.
&&
.Fire Weather...
Hazardous fire weather conditions are not expected over the next
several days across the area.
&&
.Hydrology...
There will be the potential for localized very heavy rainfall today,
and possibly again late tonight and into early Friday, across parts
of the Florida Panhandle and Big Bend. The greatest chance for
rainfall amounts exceeding 6 inches through Friday would be in the
lower portions of river basins (closer to the Gulf of Mexico).
Therefore, the threat of widespread river flooding is not
particularly high, but some smaller streams in the Florida
Panhandle, and perhaps rivers such as the Steinhatchee River and
Econfina River in the Florida Big Bend could be affected. The main
threat from the localized heavy rainfall would be flash flooding of
urban or low lying areas.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 92 75 95 76 95 / 60 30 40 30 40
Panama City 87 80 90 80 90 / 60 30 40 30 40
Dothan 95 76 97 76 97 / 50 20 30 20 30
Albany 95 75 96 75 95 / 30 20 30 20 30
Valdosta 93 74 95 74 95 / 70 30 40 30 40
Cross City 88 75 92 74 93 / 80 60 50 30 50
Apalachicola 89 79 92 79 92 / 80 40 40 40 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...FLASH FLOOD WATCH through Friday morning FOR Calhoun-Coastal Bay-
Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal
Jefferson-Coastal Taylor-Coastal Wakulla-Inland Bay-Inland
Dixie-Inland Franklin-Inland Gulf-Inland Taylor-Inland
Wakulla-Lafayette-Liberty.
HIGH RIP CURRENT RISK through Friday morning for Coastal
Bay-Coastal Gulf.
GA...NONE. AL...NONE. GM...NONE. &&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
247 PM CDT THU JUL 16 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 246 PM CDT THU JUL 16 2015
REMNANTS OF EARLIER MCS HAVE EXITED THE FORECAST AREA...AND BREAKS
IN THE CLOUD COVER ARE BECOMING MORE FREQUENT ACROSS MUCH OF THE CWA
THIS AFTERNOON EXCEPT THE FAR NORTHWEST. CAP IS QUICKLY ERODING TO
OUR WEST...AND SPC MESOANALYSIS SHOWING CAPE`S ABOVE 3000 J/KG AS
CLOSE AS THE MISSISSIPPI RIVER. VISIBLE SATELLITE IMAGERY STARTING
SO SHOW SOME AGITATION TO THE CUMULUS CLOUDS ACROSS NORTH CENTRAL
MISSOURI AND SOUTH CENTRAL IOWA...IN AN AREA WHERE THE HRRR HAS BEEN
PERSISTENT IN STARTING UP THE NEXT ROUND OF CONVECTION. ITS SOLUTION
EXPANDS THE CONVECTION NORTHEAST INTO NORTH CENTRAL ILLINOIS THROUGH
VERY LATE AFTERNOON...WITH THE LATEST SOLUTIONS FAVORING AN EASTWARD
SPREAD NORTH OF THE I-72 CORRIDOR THROUGH THE EVENING. OTHER HIGH-
RESOLUTION MODELS SUCH AS THE NMM AND ARW ALSO FAVOR THE NORTHERN
THIRD OF THE STATE...WITH LESSER OF A SOUTHWEST EXTENT. THUS...WILL
FOCUS THE HIGHEST POP`S ACROSS THE NORTHERN THIRD OF THE FORECAST
AREA.
AFTER COLLABORATION WITH WFO CHICAGO...HAVE EXPANDED THE FLASH FLOOD
WATCH A TAD SOUTHWARD AND THEN EAST THROUGH CHAMPAIGN AND VERMILION
COUNTIES. PRECIPITABLE WATER VALUES ANALYZED OVER 2 INCHES ACROSS
NORTHERN MISSOURI...AND THIS WILL BE SHIFTING EAST WITH TIME.
MESOSCALE MODELS FOCUS THE HIGHEST RAIN TOTALS ACROSS THE NORTHWEST
CWA...BUT PARTS OF THE FAR NORTHEAST HAVE ALSO HAD A FEW INCHES OVER
THE LAST SEVERAL DAYS AND ARE A BIT MORE FLOOD PRONE. MOST OF THE
NORTH HALF OF ILLINOIS IS IN A SLIGHT RISK OF FLASH FLOODING PER
GUIDANCE FROM WPC.
&&
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 246 PM CDT THU JUL 16 2015
SPOTTY SHOWERS/STORMS POSSIBLE FRIDAY ACROSS CENTRAL AND SOUTHEAST
ILLINOIS WITH A WEAK SURFACE BOUNDARY IN THE VICINITY. HOWEVER, THE
PRIMARY THEME AS WE HEAD INTO FRIDAY AFTERNOON (AS WELL AS SATURDAY
AND SUNDAY AFTERNOON) IS THE VERY WARM HEAT INDEX VALUES. THE
SOUTHWESTERLY LOW LEVEL THAT DEVELOPS ACROSS THE AREA TONIGHT WILL
LINGER THROUGH MOST OF THE WEEKEND, TRANSPORTING CONSIDERABLE HEAT
AND HUMIDITY INTO THE AREA. DAYTIME HIGHS AROUND 90S ARE LIKELY
THROUGH SUNDAY, WITH 850 MB TEMPERATURES IN THE LOWER 20S, AND
SURFACE DEW POINTS SHOULD BE WELL INTO THE 70S. THIS HEAT AND
HUMIDITY WILL COMBINE TO PRODUCE HEAT INDEX VALUES FROM 100-105 OR A
LITTLE WARMER DURING PEAK HEATING TIMES. THIS IS CLOSE TO HEAT
ADVISORY LEVELS, AND AN ADVISORY MAY BE NEEDED. HOWEVER, OPTED TO
HOLD OFF UNTIL HEAT INDEX VALUES ARE MORE SOLIDLY 105 OR BETTER.
FORECAST SOUNDINGS SUGGEST THE LOCAL AIRMASS SHOULD BE MOSTLY CAPPED
TO SURFACE BASED CONVECTION INTO SUNDAY (PRONOUNCED WARM LAYER JUST
ABOVE 850 MB). HOWEVER, ELEVATED STORM CHANCES WILL INCREASE
SATURDAY NIGHT AS WARM ADVECTION ALOFT INCREASES AHEAD OF AN
APPROACHING SHORT WAVE. THIS WAVE WILL DRIVE A FRONT THROUGH THE
AREA ON SUNDAY, PRODUCING THE HIGHEST CHANCES FOR SHOWERS/STORMS OF
THE NEXT FEW DAYS (ASIDE FROM TONIGHT). THE STRENGTH OF THIS SYSTEM
ALSO SUPPORTS SOME STRONG TO SEVERE STORMS SUNDAY INTO SUNDAY NIGHT.
SLIGHTLY COOLER AND LESS HUMID CONDITIONS ARE EXPECTED BEHIND
SUNDAY`S SYSTEM FOR THE REMAINDER OF THE FORECAST PERIOD. THE
SOUTHWARD PASSAGE OF THE FRONT WITH SUNDAY`S SYSTEM WILL ALSO HELP
TO SHUNT THE BEST SHOWER/STORM CHANCES TO OUR SOUTH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1222 PM CDT THU JUL 16 2015
CONVECTIVE COMPLEX THAT HAS BEEN TRAVERSING CENTRAL ILLINOIS THIS
MORNING HAS BEEN FADING...AND ONLY SOME LINGERING VCTS EXPECTED
FROM IT AT KCMI OVER THE NEXT HOUR OR SO. WILL BE WATCHING FOR
SOME RENEWED SHOWER/STORM DEVELOPMENT AROUND MID AFTERNOON FROM
NORTHERN ILLINOIS TO NORTHERN MISSOURI. HAVE ADDED A TEMPO PERIOD
OF MVFR CONDITIONS AT KPIA LATE AFTERNOON...BUT CONFIDENCE
ELSEWHERE IS NOT STRONG ENOUGH TO GO MORE THAN VCTS AT THIS TIME.
CURRENTLY THINKING THAT THE THREAT FOR THUNDERSTORMS SHOULD BE OUT
OF THE TAF SITES BY 06Z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT FRIDAY FOR ILZ027>031-036>038-
041>046.
&&
$$
SHORT TERM...GEELHART
LONG TERM...BAK
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
ISSUED BY NATIONAL WEATHER SERVICE NORTHERN INDIANA
1251 PM EDT THU JUL 16 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 354 AM EDT THU JUL 16 2015
HIGH PRESSURE AND DRY WEATHER TODAY WILL BE SHORT-LIVED AS A WARM
FRONT AND AN UPPER WAVE BRING CHANCES FOR THUNDERSTORMS BACK TO
NORTHWESTERN PARTS OF CENTRAL INDIANA LATE TODAY AND TONIGHT. A MORE
PROGRESSIVE PATTERN WILL SET UP ACROSS THE NORTHERN U.S. AND THIS
WILL SET INDIANA UP FOR CHANCES FOR THUNDERSTORMS EVERY DAY. HIGH
TEMPERATURES WILL CLIMB INTO THE 90S FOR FRIDAY THROUGH THE WEEKEND
AND HEAT INDEX VALUES COULD EXCEED 100.
&&
.NEAR TERM /TODAY/...
ISSUED AT 354 AM EDT THU JUL 16 2015
CURRENT RADAR MOSAIC SHOWS SOME SHOWERS ACROSS NORTHWESTERN ILLINOIS
MOVING EAST. CURRENT HRRR AND NAM BRING THESE SHOWERS INTO THE
FORECAST AREA THIS MORNING/EARLY AFTERNOON BUT RAP/GFS DO NOT. GIVEN
THE SHORTWAVE MOVING THROUGH ALOFT CAN/T RULE OUT A SHOWER IN
CENTRAL INDIANA THIS MORNING...BUT THINK POSSIBILITY COULD BE BETTER
FOR A BRIEF SPRINKLE GIVEN DRIER AIR MASS HERE. BROUGHT ISOLATED
SPRINKLES INTO PARTS OF THE AREA BY LATE MORNING.
BY LATE AFTERNOON A STRONGER SHORTWAVE WILL APPROACH FROM THE
NORTHWEST. MODELS HAVE TRENDED A LITTLE QUICKER WITH THIS WAVE THE
PAST FEW RUNS SO WILL INCLUDE SOME POPS BEFORE 0Z IN THE
NORTHWEST...BUT STILL LOOKS LIKE THE MAJORITY OF THE FORCING FROM
THIS WAVE WILL ARRIVE DURING THE TONIGHT PERIOD.
FOR HIGH TEMPERATURES FAVORED WARMER MAV NUMBERS AND WENT UP A BIT
FROM THERE IN THE SOUTH BASED ON YESTERDAY HIGH TEMPERATURES
EXCEEDING GUIDANCE AND TODAY GETTING SOME WARM ADVECTION BY THE
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 354 AM EDT THU JUL 16 2015
FORECAST FOCUS IS ON HIGH TEMPERATURES AND THUNDERSTORM CHANCES.
GUIDANCE NUMBERS ARE FAIRLY SIMILAR FOR TEMPERATURES AND GENERALLY
USED A CONSENSUS...BUT WITH POPS THERE ARE SOME DIFFERENCES IN THE
NUMBERS DUE MOSTLY TO TIMING DISCREPANCIES.
A SHORTWAVE WILL APPROACH TONIGHT FROM THE NORTHWEST AND BRING
ENOUGH FORCING WITH IT TO BRING CHANCES FOR THUNDERSTORMS TO ABOUT
THE NORTHERN HALF OR SO OF THE AREA. A WARM FRONT MOVING THROUGH AS
WELL WILL HELP WITH THE FORCING AND BEHIND IT MORE WARM MOIST AIR
WILL FLOW INTO CENTRAL INDIANA. NOT CERTAIN RADAR WILL BE CLEAR
FRIDAY MORNING GIVEN THE VARIETY IN TIMING OF THE SHORTWAVE IN THE
OPERATIONAL MODELS WILL KEEP A SLIGHT CHANCE IN THE MORNING. BY
AFTERNOON INCREASING INSTABILITY WITH TEMPERATURES ACROSS CENTRAL
INDIANA IN THE UPPER 80S TO LOWER 90S AND DEW POINTS RETURNING TO
AROUND 70 SHOULD SEE SOME STORMS DEVELOP IN THE AFTERNOON/EVENING
HOURS. AS THE UPPER RIDGE ACROSS THE SOUTHERN U.S. FLATTENS AND
ALLOWS PROGRESSIVE FLOW PATTERN TO BECOME ESTABLISHED ACROSS THE
NORTHERN U.S. FOR THE REST OF THE SHORT TERM EXPECT TO SEE CHANCES
FOR THUNDERSTORMS THROUGHOUT WITH WEAK SHORTWAVES MOVING QUICKLY
THROUGH THE MAIN FLOW TO INTERACT WITH THE HOT HUMID AIRMASS.
ISOLATED SEVERE POP UP STORMS WILL BE POSSIBLE DURING THE DAYS WITH
LARGE AMOUNTS OF INSTABILITY BUT LITTLE IN THE WAY OF SHEAR.
AIR AND SOIL MOISTURE WILL SERVE TO PREVENT TEMPERATURES FROM
GETTING ANY WARMER THAN THE LOW TO MID 90S EVEN WITH WARM ADVECTION
AND PLENTY OF SUNSHINE. THIS SAID GUIDANCE SEEMS TO BE HANDLING THE
SITUATION WELL AND GENERALLY STILL USED CONSENSUS NUMBERS. HEAT
INDEX VALUES WILL LIKELY REACH THE UPPER 90S TO AROUND 100 DEGREE
MARK... AND COULD APPROACH/EXCEED 105 DEGREES ESPECIALLY IN THE
SOUTH AT TIMES FRIDAY THROUGH SUNDAY AND WILL NEED TO MONITOR FOR
POSSIBLE ADVISORY ISSUANCE WITH LATER FORECASTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 318 AM EDT THU JUL 16 2015
MAIN HIGHLIGHTS FOR THE EXTENDED ARE EXPECTED TO BE THE HEAT ON
SUNDAY ALONG WITH THUNDERSTORM CHANCES LATE IN THE WEEK INTO EARLY
NEXT WEEK ASSOCIATED WITH A COLD FRONT THAT MOVES DROP SOUTHEAST
ACROSS CENTRAL INDIANA EARLY MONDAY. STAGNANT UPPER RIDGE OVER THE
SOUTHERN PLAINS SHOULD SUPPLY A NORTHWEST UPPER FLOW TO THE OHIO
VALLEY. ANY WAVE COULD TRIGGER A THUNDERSTORM OR TWO...BUT BEST
CHANCES SHOULD BE WITH THE FRONT.
850 MILLIBAR TEMPERATURES IN THE LOWER 20S CELSIUS AND COMPRESSIONAL
HEATING...AHEAD OF THE COLD FRONT...SHOULD ALLOW TEMPERATURES TO
REACH THE LOWER 90S AT MOST SPOTS SUNDAY. THE HEAT INDEX COULD REACH
105 AT TIMES SOUTH OF BLOOMINGTON. FRONTAL PASSAGE SHOULD THEN
RESULT IN NOT AS WARM OR HUMID WEATHER BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR 161800Z TAF ISSUANCE/...
ISSUED AT 1248 PM EDT THU JUL 16 2015
WARM FRONT SHIFTING EASTWARD ACROSS THE FORECAST AREA. CLOUDS WILL
LOWER SOMEWHAT AND ISOLD -SHRA POSSIBLE IN/CLOSE TO TAF LOCATION.
MINIMAL IMPACT ON FLIGHTS AND HAVE KEPT OUT OF TAF ISSUANCE.
CONVECTION FORMS OVER IA/IL DURING THE OVERNIGHT. WITH FAST WESTERLY
FLOW EXPECT TO SEE THIS CONVECTION ENTER THE FORECAST AREA AFTER
12Z. WILL BE MONITORING MODEL TRENDS FOR POTENTIAL UPDATES TO TAF TO
INCLUDE -TS. EVEN WITH THE CONVECTION MOVING EASTWARD STILL DO NOT
ANTICIPATE WIDESPREAD LIFR CONDITIONS...HOWEVER IFR CIGS AND VSBY
POSSIBLE LATE TONIGHT/EARLY FRIDAY.
LIGHT SOUTHEAST WINDS THROUGH FIRST HALF OF THE TAF. WINDS SHIFT TO
SOUTHERLY AND INCREASE OVERNIGHT THROUGH END OF FORECAST PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...LEWIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
610 AM EDT THU JUL 16 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 354 AM EDT THU JUL 16 2015
HIGH PRESSURE AND DRY WEATHER TODAY WILL BE SHORT-LIVED AS A WARM
FRONT AND AN UPPER WAVE BRING CHANCES FOR THUNDERSTORMS BACK TO
NORTHWESTERN PARTS OF CENTRAL INDIANA LATE TODAY AND TONIGHT. A MORE
PROGRESSIVE PATTERN WILL SET UP ACROSS THE NORTHERN U.S. AND THIS
WILL SET INDIANA UP FOR CHANCES FOR THUNDERSTORMS EVERY DAY. HIGH
TEMPERATURES WILL CLIMB INTO THE 90S FOR FRIDAY THROUGH THE WEEKEND
AND HEAT INDEX VALUES COULD EXCEED 100.
&&
.NEAR TERM /TODAY/...
ISSUED AT 354 AM EDT THU JUL 16 2015
CURRENT RADAR MOSAIC SHOWS SOME SHOWERS ACROSS NORTHWESTERN ILLINOIS
MOVING EAST. CURRENT HRRR AND NAM BRING THESE SHOWERS INTO THE
FORECAST AREA THIS MORNING/EARLY AFTERNOON BUT RAP/GFS DO NOT. GIVEN
THE SHORTWAVE MOVING THROUGH ALOFT CAN/T RULE OUT A SHOWER IN
CENTRAL INDIANA THIS MORNING...BUT THINK POSSIBILITY COULD BE BETTER
FOR A BRIEF SPRINKLE GIVEN DRIER AIR MASS HERE. BROUGHT ISOLATED
SPRINKLES INTO PARTS OF THE AREA BY LATE MORNING.
BY LATE AFTERNOON A STRONGER SHORTWAVE WILL APPROACH FROM THE
NORTHWEST. MODELS HAVE TRENDED A LITTLE QUICKER WITH THIS WAVE THE
PAST FEW RUNS SO WILL INCLUDE SOME POPS BEFORE 0Z IN THE
NORTHWEST...BUT STILL LOOKS LIKE THE MAJORITY OF THE FORCING FROM
THIS WAVE WILL ARRIVE DURING THE TONIGHT PERIOD.
FOR HIGH TEMPERATURES FAVORED WARMER MAV NUMBERS AND WENT UP A BIT
FROM THERE IN THE SOUTH BASED ON YESTERDAY HIGH TEMPERATURES
EXCEEDING GUIDANCE AND TODAY GETTING SOME WARM ADVECTION BY THE
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 354 AM EDT THU JUL 16 2015
FORECAST FOCUS IS ON HIGH TEMPERATURES AND THUNDERSTORM CHANCES.
GUIDANCE NUMBERS ARE FAIRLY SIMILAR FOR TEMPERATURES AND GENERALLY
USED A CONSENSUS...BUT WITH POPS THERE ARE SOME DIFFERENCES IN THE
NUMBERS DUE MOSTLY TO TIMING DISCREPANCIES.
A SHORTWAVE WILL APPROACH TONIGHT FROM THE NORTHWEST AND BRING
ENOUGH FORCING WITH IT TO BRING CHANCES FOR THUNDERSTORMS TO ABOUT
THE NORTHERN HALF OR SO OF THE AREA. A WARM FRONT MOVING THROUGH AS
WELL WILL HELP WITH THE FORCING AND BEHIND IT MORE WARM MOIST AIR
WILL FLOW INTO CENTRAL INDIANA. NOT CERTAIN RADAR WILL BE CLEAR
FRIDAY MORNING GIVEN THE VARIETY IN TIMING OF THE SHORTWAVE IN THE
OPERATIONAL MODELS WILL KEEP A SLIGHT CHANCE IN THE MORNING. BY
AFTERNOON INCREASING INSTABILITY WITH TEMPERATURES ACROSS CENTRAL
INDIANA IN THE UPPER 80S TO LOWER 90S AND DEW POINTS RETURNING TO
AROUND 70 SHOULD SEE SOME STORMS DEVELOP IN THE AFTERNOON/EVENING
HOURS. AS THE UPPER RIDGE ACROSS THE SOUTHERN U.S. FLATTENS AND
ALLOWS PROGRESSIVE FLOW PATTERN TO BECOME ESTABLISHED ACROSS THE
NORTHERN U.S. FOR THE REST OF THE SHORT TERM EXPECT TO SEE CHANCES
FOR THUNDERSTORMS THROUGHOUT WITH WEAK SHORTWAVES MOVING QUICKLY
THROUGH THE MAIN FLOW TO INTERACT WITH THE HOT HUMID AIRMASS.
ISOLATED SEVERE POP UP STORMS WILL BE POSSIBLE DURING THE DAYS WITH
LARGE AMOUNTS OF INSTABILITY BUT LITTLE IN THE WAY OF SHEAR.
AIR AND SOIL MOISTURE WILL SERVE TO PREVENT TEMPERATURES FROM
GETTING ANY WARMER THAN THE LOW TO MID 90S EVEN WITH WARM ADVECTION
AND PLENTY OF SUNSHINE. THIS SAID GUIDANCE SEEMS TO BE HANDLING THE
SITUATION WELL AND GENERALLY STILL USED CONSENSUS NUMBERS. HEAT
INDEX VALUES WILL LIKELY REACH THE UPPER 90S TO AROUND 100 DEGREE
MARK... AND COULD APPROACH/EXCEED 105 DEGREES ESPECIALLY IN THE
SOUTH AT TIMES FRIDAY THROUGH SUNDAY AND WILL NEED TO MONITOR FOR
POSSIBLE ADVISORY ISSUANCE WITH LATER FORECASTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 318 AM EDT THU JUL 16 2015
MAIN HIGHLIGHTS FOR THE EXTENDED ARE EXPECTED TO BE THE HEAT ON
SUNDAY ALONG WITH THUNDERSTORM CHANCES LATE IN THE WEEK INTO EARLY
NEXT WEEK ASSOCIATED WITH A COLD FRONT THAT MOVES DROP SOUTHEAST
ACROSS CENTRAL INDIANA EARLY MONDAY. STAGNANT UPPER RIDGE OVER THE
SOUTHERN PLAINS SHOULD SUPPLY A NORTHWEST UPPER FLOW TO THE OHIO
VALLEY. ANY WAVE COULD TRIGGER A THUNDERSTORM OR TWO...BUT BEST
CHANCES SHOULD BE WITH THE FRONT.
850 MILLIBAR TEMPERATURES IN THE LOWER 20S CELSIUS AND COMPRESSIONAL
HEATING...AHEAD OF THE COLD FRONT...SHOULD ALLOW TEMPERATURES TO
REACH THE LOWER 90S AT MOST SPOTS SUNDAY. THE HEAT INDEX COULD REACH
105 AT TIMES SOUTH OF BLOOMINGTON. FRONTAL PASSAGE SHOULD THEN
RESULT IN NOT AS WARM OR HUMID WEATHER BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR 161200Z TAF ISSUANCE/...
ISSUED AT 610 AM EDT THU JUL 16 2015
GOOD CONFIDENCE THAT ANY BRIEF MVFR FOG SHOULD BE OVER BY ISSUANCE
TIME. UPPER WAVE IN ZONAL FLOW AND CONVECTIVE DEBRIS FROM NORTHERN
MISSOURI AND IOWA STORMS WILL BRING A MID DECK ACROSS THE TERMINALS
THROUGH THE PERIOD. DO NOT EXPECT A LOT OF DIURNAL CU WITH
CONVECTIVE TEMPERATURES OVER 100 DEGREES AND APPROACHING WARM FRONT
WELL TO THE WEST. THE FRONT SHOULD MOVE TO NEAR
LAF...TONIGHT...HOWEVER AND COULD BRING A STORM OR TWO THERE AFTER
00Z AND IND AND HUF AFTER 03Z. EVEN SO...COVERAGE EXPECTED TO BE LOW
ENOUGH TO LEAVE A MENTION OUT...ESPECIALLY WITH IT BEING 12 PLUS
HOURS OUT. WILL TRY AGAIN FOR THE 18Z OR 00Z TAFS TO SEE IF WE CAN
FIND A PERIOD OF OPPORTUNITY REGARDING THUNDERSTORMS.
SOUTHEAST WINDS WILL BECOME SOUTH THIS MORNING LESS THAN 10 KNOTS.
WINDS SHOULD PICK UP A BIT AT IND AFTER 12Z FRIDAY AS THEY SWITCH TO
THE SOUTHWEST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
356 AM EDT THU JUL 16 2015
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 354 AM EDT THU JUL 16 2015
HIGH PRESSURE AND DRY WEATHER TODAY WILL BE SHORT-LIVED AS A WARM
FRONT AND AN UPPER WAVE BRING CHANCES FOR THUNDERSTORMS BACK TO
NORTHWESTERN PARTS OF CENTRAL INDIANA LATE TODAY AND TONIGHT. A MORE
PROGRESSIVE PATTERN WILL SET UP ACROSS THE NORTHERN U.S. AND THIS
WILL SET INDIANA UP FOR CHANCES FOR THUNDERSTORMS EVERY DAY. HIGH
TEMPERATURES WILL CLIMB INTO THE 90S FOR FRIDAY THROUGH THE WEEKEND
AND HEAT INDEX VALUES COULD EXCEED 100.
&&
.NEAR TERM /TODAY/...
ISSUED AT 354 AM EDT THU JUL 16 2015
CURRENT RADAR MOSAIC SHOWS SOME SHOWERS ACROSS NORTHWESTERN ILLINOIS
MOVING EAST. CURRENT HRRR AND NAM BRING THESE SHOWERS INTO THE
FORECAST AREA THIS MORNING/EARLY AFTERNOON BUT RAP/GFS DO NOT. GIVEN
THE SHORTWAVE MOVING THROUGH ALOFT CAN/T RULE OUT A SHOWER IN
CENTRAL INDIANA THIS MORNING...BUT THINK POSSIBILITY COULD BE BETTER
FOR A BRIEF SPRINKLE GIVEN DRIER AIR MASS HERE. BROUGHT ISOLATED
SPRINKLES INTO PARTS OF THE AREA BY LATE MORNING.
BY LATE AFTERNOON A STRONGER SHORTWAVE WILL APPROACH FROM THE
NORTHWEST. MODELS HAVE TRENDED A LITTLE QUICKER WITH THIS WAVE THE
PAST FEW RUNS SO WILL INCLUDE SOME POPS BEFORE 0Z IN THE
NORTHWEST...BUT STILL LOOKS LIKE THE MAJORITY OF THE FORCING FROM
THIS WAVE WILL ARRIVE DURING THE TONIGHT PERIOD.
FOR HIGH TEMPERATURES FAVORED WARMER MAV NUMBERS AND WENT UP A BIT
FROM THERE IN THE SOUTH BASED ON YESTERDAY HIGH TEMPERATURES
EXCEEDING GUIDANCE AND TODAY GETTING SOME WARM ADVECTION BY THE
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 354 AM EDT THU JUL 16 2015
FORECAST FOCUS IS ON HIGH TEMPERATURES AND THUNDERSTORM CHANCES.
GUIDANCE NUMBERS ARE FAIRLY SIMILAR FOR TEMPERATURES AND GENERALLY
USED A CONSENSUS...BUT WITH POPS THERE ARE SOME DIFFERENCES IN THE
NUMBERS DUE MOSTLY TO TIMING DISCREPANCIES.
A SHORTWAVE WILL APPROACH TONIGHT FROM THE NORTHWEST AND BRING
ENOUGH FORCING WITH IT TO BRING CHANCES FOR THUNDERSTORMS TO ABOUT
THE NORTHERN HALF OR SO OF THE AREA. A WARM FRONT MOVING THROUGH AS
WELL WILL HELP WITH THE FORCING AND BEHIND IT MORE WARM MOIST AIR
WILL FLOW INTO CENTRAL INDIANA. NOT CERTAIN RADAR WILL BE CLEAR
FRIDAY MORNING GIVEN THE VARIETY IN TIMING OF THE SHORTWAVE IN THE
OPERATIONAL MODELS WILL KEEP A SLIGHT CHANCE IN THE MORNING. BY
AFTERNOON INCREASING INSTABILITY WITH TEMPERATURES ACROSS CENTRAL
INDIANA IN THE UPPER 80S TO LOWER 90S AND DEW POINTS RETURNING TO
AROUND 70 SHOULD SEE SOME STORMS DEVELOP IN THE AFTERNOON/EVENING
HOURS. AS THE UPPER RIDGE ACROSS THE SOUTHERN U.S. FLATTENS AND
ALLOWS PROGRESSIVE FLOW PATTERN TO BECOME ESTABLISHED ACROSS THE
NORTHERN U.S. FOR THE REST OF THE SHORT TERM EXPECT TO SEE CHANCES
FOR THUNDERSTORMS THROUGHOUT WITH WEAK SHORTWAVES MOVING QUICKLY
THROUGH THE MAIN FLOW TO INTERACT WITH THE HOT HUMID AIRMASS.
ISOLATED SEVERE POP UP STORMS WILL BE POSSIBLE DURING THE DAYS WITH
LARGE AMOUNTS OF INSTABILITY BUT LITTLE IN THE WAY OF SHEAR.
AIR AND SOIL MOISTURE WILL SERVE TO PREVENT TEMPERATURES FROM
GETTING ANY WARMER THAN THE LOW TO MID 90S EVEN WITH WARM ADVECTION
AND PLENTY OF SUNSHINE. THIS SAID GUIDANCE SEEMS TO BE HANDLING THE
SITUATION WELL AND GENERALLY STILL USED CONSENSUS NUMBERS. HEAT
INDEX VALUES WILL LIKELY REACH THE UPPER 90S TO AROUND 100 DEGREE
MARK... AND COULD APPROACH/EXCEED 105 DEGREES ESPECIALLY IN THE
SOUTH AT TIMES FRIDAY THROUGH SUNDAY AND WILL NEED TO MONITOR FOR
POSSIBLE ADVISORY ISSUANCE WITH LATER FORECASTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 318 AM EDT THU JUL 16 2015
MAIN HIGHLIGHTS FOR THE EXTENDED ARE EXPECTED TO BE THE HEAT ON
SUNDAY ALONG WITH THUNDERSTORM CHANCES LATE IN THE WEEK INTO EARLY
NEXT WEEK ASSOCIATED WITH A COLD FRONT THAT MOVES DROP SOUTHEAST
ACROSS CENTRAL INDIANA EARLY MONDAY. STAGNANT UPPER RIDGE OVER THE
SOUTHERN PLAINS SHOULD SUPPLY A NORTHWEST UPPER FLOW TO THE OHIO
VALLEY. ANY WAVE COULD TRIGGER A THUNDERSTORM OR TWO...BUT BEST
CHANCES SHOULD BE WITH THE FRONT.
850 MILLIBAR TEMPERATURES IN THE LOWER 20S CELSIUS AND COMPRESSIONAL
HEATING...AHEAD OF THE COLD FRONT...SHOULD ALLOW TEMPERATURES TO
REACH THE LOWER 90S AT MOST SPOTS SUNDAY. THE HEAT INDEX COULD REACH
105 AT TIMES SOUTH OF BLOOMINGTON. FRONTAL PASSAGE SHOULD THEN
RESULT IN NOT AS WARM OR HUMID WEATHER BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR 160000Z TAFS/...
ISSUED AT 1205 AM EDT THU JUL 16 2015
TAFS MAINLY VFR WITH THE EXCEPTION OF A BRIEF 3 TO 4 HOUR PERIOD OF
BR MVFR AT MOST OF THE TERMINALS SAVE FOR IND...WITH LIFR POSSIBLE
AT SOME OF THE OUTLYING SITES...ESPECIALLY BMG/HUF WHICH WERE
TEMPO/D DOWN TO LIFR (2SM BR) FROM 08-12Z BASED ON CALM WINDS AND
-1/-2 OR LESS DEW POINT DEPRESSIONS.
SUNSHINE LATER THIS MORNING WILL GIVE WAY TO DEVELOPING CUMULUS BY
EARLY THIS AFTERNOON...BUT ALSO EXPECT SOME MID CLOUD DEVELOPMENT AS
WELL AS A RESULT OF WARM MOIST AIR BEGINNING TO RETURN TO THE
REGION. POSSIBLE SHOWERS FROM A SYSTEM MOVING ACROSS THE NORTH
SHOULD NOT HAVE AN IMPACT ON THE TAF SITES EXCEPT FOR AN INCREASE IN
CLOUD COVERAGE.
WINDS WILL BE LIGHT AND NORTHERLY EARLY...THEN BECOMING LIGHT TO CALM
VERY EARLY THIS MORNING. AND FINALLY PICKING UP OUT OF THE S/SE BY
15-16Z AT OR BELOW 8-10 KT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
601 AM CDT THU JUL 16 2015
.MESOSCALE UPDATE...
ISSUED AT 519 AM CDT THU JUL 16 2015
SATELLITE TRENDS INDICATE CLOUD TOPS HAVE WARMED FROM -75 CELSIUS IN
THE MCS ACROSS IOWA. HOWEVER...THE MCS DID CYCLE THROUGH ANOTHER
COOLING/WARMING/COOLING TREND IN THE 04-08Z TIME FRAME.
VWP FROM SURROUNDING RADAR SITES INDICATE 850MB INFLOW INTO THE
MCS HAS INCREASED TO 35-40 KNOTS SO THE MCS IS LIKELY AT MATURITY
AND SHOULD START A SLOW DECAY SHORTLY AFTER SUNRISE AS THE LLJ
BEGINS TO WEAKEN. CORFIDI VECTORS INDICATE THE MCS SHOULD
CONTINUE SLOWLY MOVING TO THE EAST OR JUST A LITTLE NORTH OF EAST.
RADAR HAS 1 HOUR RAINFALL RATES OF 1.3 TO 1.5 INCHES/HOUR WITH
SMALL POCKETS OF 1.5 TO 2.0 INCHES/HOUR FROM KEOKUK COUNTY SOUTH
TO VAN BUREN COUNTY THAT ARE MOVING EAST. RAP MODEL TRENDS HAVE
THE BACKWARD AND FORWARD CORFIDI VECTORS NEARLY PERPENDICULAR TO
EACH OTHER ACROSS SOUTHEAST IOWA AND INTO WEST CENTRAL ILLINOIS.
THUS THE RISK OF ANY FLASH FLOODING DEVELOPING WOULD BE HIGHER
THERE.
BASED ON THE CURRENT 1 HOUR FLASH FLOOD GUIDANCE...IF RAINFALL
RATES REMAIN AT OR BELOW 1.5 INCHES/HOUR THE GROUND SHOULD BE ABLE
TO HANDLE THE CURRENT ROUND OF RAIN BUT THERE WOULD BE AREAS OF
STANDING WATER. URBAN AREAS MAY SEE PROBLEMS WITH SOME STREET
FLOODING.
IF THE RAP MODEL TRENDS ARE CORRECT...IT APPEARS THERE WILL BE A
BREAK IN THE RAIN ONCE THE CURRENT MCS DISSIPATES.
HOWEVER...BOUNDARIES AND THE COLD POOL LEFT OVER FROM THIS MCS
WOULD THEN BE THE FOCUS POINTS FOR THE DIURNAL CONVECTION THAT
DEVELOPS THIS AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 358 AM CDT THU JUL 16 2015
AT 330 AM CDT...MID-LEVEL CLOUDS HAVE OVERSPREAD
EASTERN IOWA/WESTERN ILLINOIS/NORTHEASTERN MISSOURI DOWNSTREAM OF
A SLOW MOVING CLUSTER OF SHOWERS AND THUNDERSTORMS IN SOUTH-
CENTRAL IOWA AND NORTHWEST MISSOURI. SO FAR TONIGHT...ANY
THUNDERSTORM ACTIVITY HAS REMAINED WEST OF THE DVN CWA BUT ONE
RELATIVELY LARGE COMPLEX IS ONLY ABOUT ONE TIER OF COUNTIES TO THE
WEST AND IS SLOWLY LIFTING NORTHEAST.
A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE COUNTIES ROUGHLY
ALONG AND SOUTH OF HIGHWAY 30...BUT DOES NOT INCLUDE LINN OR
BENTON COUNTIES. THE WATCH IS IN EFFECT THROUGH LATE TONIGHT.
THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FOR THE COUNTIES ALONG AND SOUTH OF A HIGHWAY 30.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT THU JUL 16 2015
TODAY AND TONIGHT...ROUNDS OF SHOWERS AND THUNDERSTORMS ARE
LIKELY. THE FIRST WAVE WILL MOVE FROM WEST TO EAST ACROSS THE
FORECAST AREA THIS MORNING PRODUCING HEAVY RAINFALL RATES IN
EXCESS OF 1 INCH PER HOUR MOSTLY WEST OF THE MISSISSIPPI AND SOUTH
OF I-80. A SECONDARY DISTURBANCE...CURRENTLY SITUATED OVER KANSAS
AND NEBRASKA IS FORECAST TO TRAVERSE THROUGH E IOWA/NE MISSOURI/W
ILLINOIS... SCATTERED CONVECTIVE REDEVELOPMENT IS LIKELY AS THE
DISTURBANCE MOVES THROUGH.
ANALYSIS OF SYNOPTIC AND HI-RES MODELS COMBINED WITH ANTICIPATED
CAPE GRADIENTS AND SFC BASED DESTABILIZATION FAVORS AREAS SOUTH OF
I-80 TO HAVE THE HIGHEST PROBABILITIES FOR SCATTERED STRONG TO
SEVERE THUNDERSTORMS AND ZONES OF FLASH FLOODING.
PWATS ARE FORECAST NEAR 2 INCHES...MUCAPE VALUES BETWEEN 1500-3000
J/KG...BUT 0-6KM SHEAR ONLY NEAR 35 KTS POSSIBLY 40 KTS. THEREFORE
THE GREATEST SEVERE WEATHER RISKS TODAY ARE FIRST FLASH FLOODING
AND SECOND DAMAGING WIND GUSTS...WITH A LITTLE LOWER THREAT FOR
LARGE HAIL. STORM MOTION VECTORS INDICATE GENERAL PROPAGATION THIS
AFTN AND EVENING ARE 30 MPH...ALTHOUGH BACK- BUILDING VECTORS
SUGGEST CONTINUAL REDEVELOPMENT INTO ANY THUNDERSTORM COMPLEX FROM
A SOUTHERLY DIRECTION WHICH CONCEPTUALLY MAKES SENSE GIVEN
ORIENTATION OF 850MB MOISTURE TRANSPORT VECTORS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 358 AM CDT THU JUL 16 2015
A PERIOD OF VERY WARM AND HUMID WEATHER WILL BE SEEN FROM FRIDAY
THROUGH SATURDAY NIGHT AND POSSIBLY INTO SUNDAY.
VERY WARM AND HUMID CONDITIONS WILL BE SEEN ACROSS THE AREA ON
FRIDAY. HEADLINES FOR HEAT WILL PROBABLY BE NEEDED FOR AREAS ALONG
AND SOUTH OF HIGHWAY 30. MOST MODELS POINT TO FRIDAY BEING DRY.
HOWEVER...ISOLATED DIURNAL CONVECTION CANNOT BE COMPLETELY RULED OUT.
FRIDAY NIGHT INTO SATURDAY IS MORE UNCERTAIN. SOME MODELS ARE
SUGGESTING A THUNDERSTORM COMPLEX MOVING FROM MINNESOTA INTO
SOUTHERN WISCONSIN FRIDAY NIGHT...CATCHING THE THE FAR NORTH. OTHER
MODELS KEEP THE AREA DRY. IF STORMS MOVE ACROSS THE FAR NORTH FRIDAY
NIGHT...THEN BOUNDARIES CREATED BY THOSE STORMS WOULD HELP CREATE
ADDITIONAL STORMS ACROSS THE AREA ON SATURDAY.
HEADLINES FOR HEAT APPEAR TO BE NEEDED SATURDAY FOR AREAS SOUTH OF
HIGHWAY 30. HOWEVER...IF STORMS DEVELOP FRIDAY NIGHT AND CONTINUE
INTO SATURDAY...HEAT HEADLINES BECOME MORE UNCERTAIN.
SATURDAY NIGHT A COLD FRONT APPROACHES THE AREA FROM THE PLAINS.
WARM AND HUMID AIR ACROSS THE AREA SHOULD RESULT IN ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS DEVELOPING.
SUNDAY ON...THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS
SUNDAY/SUNDAY NIGHT AS ANOTHER COLD FRONT MOVES THROUGH THE AREA.
THERE ARE DISAGREEMENTS AMONG THE MODELS AS TO WHEN THE FRONT WILL
MOVE THROUGH THE AREA. VERY WARM AND HUMID CONDITIONS WILL BE SEEN
AHEAD OF THE FRONT WITH HEAT INDEX READING APPROACHING 100.
THE WEATHER ON MONDAY WILL DEPEND UPON WHEN THE COLD FRONT MOVES
THROUGH THE AREA. IF THE FRONT MOVES THROUGH ON SUNDAY...THEN MONDAY
COULD EASILY END UP BEING DRY. IF THE FRONT MOVES THROUGH SUNDAY
NIGHT THEN LINGERING RAIN MAY BE SEEN ACROSS THE AREA ON MONDAY.
AS SUCH THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS ON
MONDAY FOR THE POTENTIAL OF LINGERING RAIN. TEMPERATURES WILL BE
COOLER THAN NORMAL.
MONDAY NIGHT/TUESDAY IS CURRENTLY LOOKING DRY AS HIGH PRESSURE MOVES
THROUGH THE MIDWEST. HOWEVER...THERE ARE SOME WEAK DISTURBANCES
ALOFT MOVING THROUGH THAT MIGHT GENERATE SOME ISOLATED CONVECTION.
TUESDAY NIGHT/WEDNESDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS
FOR THE AREA. THERE ARE SOME WEAK UPPER LEVEL DISTURBANCES PROJECTED
TO MOVE THROUGH THE AREA THAT MIGHT GENERATE SOME SHOWERS AND
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1148 PM CDT WED JUL 15 2015
MCS CURRENTLY DEVELOPING ACRS NORTHWESTERN MO INTO SOUTHWESTERN IA
WILL COME ACRS AND PROBABLY BE A BIG IMPACT AT MOST OF THE TAF
SITES EXCEPT MAYBE DBQ WITH MVFR TO IFR CONDITIONS FROM
THUNDERSTORMS AND POSSIBLE HEAVY RAIN REDUCING VSBYS AFTER 3 AM
CDT. IF THIS ACTIVITY CAN MOVE OUT OF THE AREA BY LATE MORNING...
A POSSIBLE VFR MIDDAY INTO EARLY AFTERNOON BEFORE MORE SCTRD
STORMS WILL BE POSSIBLE IN THE VCNTY OF MOST OF THE AIRPORTS
DURING THE LATER AFTERNOON INTO THE EVENING HOURS. SOME OF THESE
STORMS COULD BE ON THE STRONG SIDE. EAST TO SOUTHEAST WINDS
OVERNIGHT...SOUTHEASTERLY THU MORNING AND THEN POSSIBLY BECOMING
SOUTHERLY AND GUSTY UP TO 20 KTS BY THU AFTERNOON. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR CEDAR-CLINTON-DES
MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-LEE-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR BUREAU-HANCOCK-
HENDERSON-HENRY IL-MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-
WARREN-WHITESIDE.
MO...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...08
AVIATION...12
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1240 AM CDT THU JUL 16 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 327 PM CDT WED JUL 15 2015
CHALLENGING FORECAST FOR THE OVERNIGHT. TWO DISTINCT VORTICITY
MAXIMUM OVER THE REGION THIS AFTERNOON...ONE ASSOCIATED WITH THE
H500 SHORTWAVE IN EASTERN NEBRASKA AND THE OTHER FARTHER SOUTH OVER
NORTHWEST MISSOURI. TO COMPLICATE MATTERS A WEAK SFC LOW AND TROUGH
EXTEND FROM SOUTH CENTRAL NEBRASKA TO NORTHEAST IOWA. SYNOPTIC SCALE
MODELS HAVE BEEN FAIRLY CONSISTENT WITH FORCING INCREASING OVER
WEST CENTRAL TO NORTHEAST IOWA BY 12Z...FOCUSING AN EXPANDING AREA
OF MODERATE TO HEAVY RAINFALL IN THIS LOCATION. OF THESE THE EURO
HAS TRENDED SLIGHTLY FARTHER SOUTH WITH WIDESPREAD COVERAGE OF
RAINFALL. THE HRRR IS CONCENTRATING THE LIONS SHARE OF FORCING
OVER SOUTHERN IOWA TONIGHT...RIGHT ON THE NORTHERN EDGE OF MORE
ROBUST INSTABILITY. WITH BOTH VORT MAXES PLAYING A ROLE IN THE
OVERNIGHT FORECAST...IT LOOKS LIKE AN AREA OF MODERATE TO
POTENTIALLY LOCALLY HEAVY RAINFALL WILL OCCUR FROM WEST CENTRAL
TOWARD NORTHEAST WITH A SECONDARY MAXIMUM OVER THE SOUTHERN
SECTIONS SOUTH OF INTERSTATE 80...EAST TO ABOUT I35 AGAIN THIS
AREA COULD SEE LOCALLY HEAVY RAINFALL. WITH THE MAXIMUM
INSTABILITY SOUTH OF IOWA NOW...THE SOUTHERN AREAS SHOULD FILL IN
LATER THIS EVENING AS THE H850 LOW LEVEL JET OF 30 TO 40KT
INCREASES AFTER 03-04Z. PRECIPITABLE WATER VALUES ARE EXPECTED TO
INCREASE TO NEARLY 2 INCHES BY 06Z OVER MUCH OF THE REGION WITH
WARM CLOUD DEPTHS IN EXCESS OF 13KFT...PROMOTING EFFICIENT
RAINFALL PROCESSES. THE DAY1 CONVECTIVE OUTLOOK HAS BEEN INCREASED
FOR A SLIGHT RISK ACROSS THE SOUTH WITH SOME POTENTIAL FOR SEVERE
STORMS SOUTHWEST/WEST THROUGH THE EVENING HOURS...THOUGH MAIN
CONCERNS REMAIN POTENTIAL FOR LOCALLY HEAVY RAINFALL. WITH FLASH
FLOOD GUIDANCE BETWEEN 2 TO 3 INCHES PER 3 HOURS OVER THE
WEST/SOUTHWEST...WE MAY SEE SOME LOCALIZED FLASH FLOODING OVER
PORTIONS OF WESTERN/SOUTHWEST SECTIONS TONIGHT. FOR NOW HAVE HELD
OFF ON HEADLINES DUE TO SOME UNCERTAINTIES IN THE DEVELOPMENT OF
CONVECTION AND EVENTUAL EVOLUTION. LOWS WILL HOLD IN THE UPPER 60S
TO LOWER 70S WITH UNCOMFORTABLE DEW POINTS NEAR THE SAME VALUES.
WINDS WILL INCREASE A BIT FROM THE SOUTH DURING THE OVERNIGHT
HOURS.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 327 PM CDT WED JUL 15 2015
THE STORM SYSTEM SET TO AFFECT THE AREA TONIGHT...AS DISCUSSED AT
LENGTH IN THE SHORT TERM SECTION ABOVE...WILL CLEAR OUT TO THE
EAST ON THURSDAY MORNING. LARGE SCALE MODELS ARE A BIT SLOWER WITH
THIS CLEARING...WHILE THE HIGH RESOLUTION MODELS ARE SOMEWHAT
FASTER WHICH IS MORE CONSISTENT WITH CLIMATOLOGY IN THIS SYNOPTIC
SET UP. FURTHERMORE THERE ARE INDICATIONS THAT A WEAK UPPER
IMPULSE MOVING IN BEHIND THE INITIAL WAVE...COMBINED WITH
AFTERNOON DESTABILIZATION AND LINGERING OUTFLOW BOUNDARIES FROM
MORNING CONVECTION...MAY LEAD TO SOME ISOLATED STORM REDEVELOPMENT
LATE IN THE DAY OR THURSDAY EVENING. AS A RESULT OF ALL OF THESE
FACTORS...MAINTAINED A FAIRLY RAPID CLEARING OF HIGHER POPS TO THE
EAST ON THURSDAY MORNING BUT HELD SOME LOWER POPS BACK IN THE
SOUTH AND WEST AT TIMES MAINLY THURSDAY EVENING. ALSO MAINTAINED
SOME FOG MENTION LATE THURSDAY NIGHT/EARLY FRIDAY MORNING GIVEN
THE LIGHT AND VARIABLE WINDS EXPECTED ALONG WITH CLEARING SKIES
AND WET GROUND/HIGH DEWPOINTS.
BY FRIDAY SOUTHERLY SURFACE WINDS WILL RETURN TO THE AREA...WITH
500 MB FLOW TURNING TO WEST SOUTHWEST AND A FRONTAL BOUNDARY
DEVELOPING WELL TO OUR NORTHWEST ACROSS SOUTH DAKOTA AND
MINNESOTA. THIS BOUNDARY WILL LIKELY PROVIDE THE IMPETUS FOR
THUNDERSTORM DEVELOPMENT FRIDAY EVENING AND FRIDAY NIGHT...BUT
THIS SHOULD LARGELY STAY NORTH OF OUR FORECAST AREA. ALSO...THERE
MAY BE SOME PEAK HEATING STORM DEVELOPMENT ACROSS OUR AREA IN THE
WARM SECTOR FRIDAY AFTERNOON AND EVENING...HOWEVER A GENERAL LACK
OF FORCING OR FOCUS MECHANISM PROHIBIT INTRODUCING POPS AT THIS
TIME. FRIDAY WILL ALSO SEE A RETURN OF MORE HEAT AND HUMIDITY...AS
LOW LEVEL WARM AIR AND MOISTURE ADVECTION BENEATH INCREASING
TEMPERATURES ALOFT PROMOTE HIGH TEMPERATURES IN THE LOWER 90S WITH
HEAT INDEX VALUES APPROACHING 100 LATE IN THE DAY. SATURDAY WILL
BE QUITE SIMILAR...WITH HOT AND HUMID CONDITIONS AND A LOW CHANCE
OF WARM SECTOR THUNDERSTORMS THAT WOULD BE ISOLATED IF THEY
DEVELOP.
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT THE FORECAST WILL BE
DOMINATED BY THE APPROACH AND PASSAGE OF THE AFOREMENTIONED
FRONTAL BOUNDARY FROM NORTHWEST TO SOUTHEAST. A WARM AND VERY
UNSTABLE AIRMASS AHEAD OF THE FRONT WILL PROMOTE VIGOROUS
THUNDERSTORM DEVELOPMENT PARTICULARLY SUNDAY AFTERNOON AND
EVENING...WITH BULK SHEAR FORECASTS CERTAINLY SUPPORTING SOME
SEVERE WEATHER THREAT WITH THE ADVANCING FRONTAL ZONE.
HOWEVER...SIGNIFICANT DIFFERENCES IN THE TIMING OF THIS PASSAGE
REMAIN AMONG THE VARIOUS MODELS. THE ECMWF HAS BEEN STICKING TO
ITS GUNS FOR THE LAST THREE RUNS WITH A MUCH FASTER PASSAGE AND
THE GFS HAS BEEN SLOWLY COMING AROUND IN THAT DIRECTION. IF THIS
OCCURS...IT WOULD RESULT IN SOMEWHAT COOLER HIGHS SUNDAY AND SHIFT
ANY SEVERE WEATHER POTENTIAL MORE ACROSS SOUTHERN AND EASTERN IOWA
RATHER THAN FURTHER NORTHWEST. FOR NOW THE UNCERTAINTY IN THIS
EVOLUTION RESULTS IN SEVERAL PERIODS OF CHANCE POPS WITH NO
LIKELIES INTRODUCED AS OF YET...BUT ONCE THE DETAILS OF TIMING
BECOME CLEARER THEN HIGHER POPS WILL NEED TO BE INTRODUCED IN ONE
OR MORE OF THE PERIODS FROM SATURDAY NIGHT THROUGH SUNDAY
NIGHT...AND SUNDAY HIGH TEMPERATURES MAY NEED TO BE ADJUSTED
FURTHER AS WELL.
AS ROUGHLY ZONAL STEERING FLOW PERSISTS INTO EARLY NEXT WEEK
TEMPERATURES BEHIND THE SUNDAY COOL FRONT WILL SLOWLY MODERATE AND
LOW RAIN CHANCES WILL PERSIST. GIVEN THE DIFFICULTY IN PREDICTING
ANY SUBTLE IMPULSES TYPICALLY MOVING THROUGH SUCH FLOW AT THIS
TIME RANGE...HAVE MAINTAINED ONLY LOW POPS AT TIMES IN THE LATTER
PART OF THE EXTENDED FORECAST PERIOD.
&&
.AVIATION...16/06Z
ISSUED AT 1237 AM CDT THU JUL 16 2015
STRONG THETA-E ADVECTION ONGOING THROUGH THE EARLY MORNING HOURS
WITH LLJ POINTED INTO IOWA. ANTICIPATE WIDESPREAD CONVECTION
THROUGH DAYBREAK ON THURSDAY WITH PRECIPITATION ENDING FROM WEST
TO EAST DURING THE MORNING. EXPECTED VFR CONDITIONS TO DETERIORATE
OVERNIGHT WITH MVFR TO IFR CONDITIONS BECOMING WIDESPREAD DURING
THE EARLY MORNING HOURS WITH NUMEROUS SHOWERS AND THUNDERSTORMS.
THESE CONDITIONS WILL PERSIST INTO THE MORNING BEFORE GRADUALLY
LIFTING CEILINGS BY AFTERNOON WILL ALLOW FOR VFR CONDITIONS ONCE
MORE. SURFACE WINDS WILL INCREASE FROM THE EAST SOUTHEAST
OVERNIGHT AND CONTINUE INTO THURSDAY BEFORE SWITCHING TO THE SOUTH
AND SOUTHWEST AS A FRONT LIFT NORTH INTO THE STATE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR ADAIR-ADAMS-
APPANOOSE-AUDUBON-CASS-CLARKE-DALLAS-DAVIS-DECATUR-GUTHRIE-
JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-POWESHIEK-
RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.
&&
$$
SHORT TERM...REV
LONG TERM...LEE
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
221 AM MDT THU JUL 16 2015
.UPDATE...
ISSUED AT 846 PM MDT WED JUL 15 2015
UPDATED THE FORECAST TO INCORPORATE LATEST THUNDERSTORM MOVEMENT
AND COVERAGE TRENDS. LATEST HRRR RUN SEEMS TO BE CAPTURING THE
MOVEMENT AND TIMING OF THUNDERSTORMS ACROSS EASTERN COLORADO
FAIRLY WELL AT THE MOMENT...SO DECIDED TO INCORPORATE THE SOLUTION
INTO THE FORECAST. THE CURRENT LINE OF STORMS ACROSS EASTERN
COLORADO SHOULD SHIFT EASTWARD AND HOLD TOGETHER FOR NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA IN THE NEXT FEW HOURS AND LAST
THROUGH ABOUT 3 MDT/4 CDT BEFORE EXITING THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 142 PM MDT WED JUL 15 2015
AS OF 2 PM CDT...1 PM MDT...SKIES ACROSS THE TRI-STATE REGION PARTLY
TO MOSTLY CLOUD WITH LOW DAYTIME CUMULUS PRESENT. TEMPERATURES ARE
IN THE 80S TO NEAR 90 IN A FEW PLACES. WINDS ARE FAIRLY LIGHT AND
VARIABLE. AT THE SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM
EASTERN NEBRASKA...ACROSS THE TRI-STATE REGION AND SOUTH INTO
EASTERN NEW MEXICO. THIS HAS LED TO THE LIGHT WINDS THIS AFTERNOON.
ALOFT...A HIGH PRESSURE RIDGE IS CENTERED OVER TEXAS. A FEW SUBTLE
MONSOON-TYPE IMPULSES WERE MOVING NORTH ON THE WESTERN RIDGE
PERIPHERY. ONE IN PARTICULAR IS LOCATED OVER NEW MEXICO...HEADING
NORTH-NORTHEAST INTO SOUTHEAST COLORADO. IT IS THIS SHORTWAVE TROUGH
THAT IS LIKELY THE FORCING FOR THIS EVENING`S THUNDERSTORMS. LATEST
SATELLITE AND WSR-88D RADAR DATA INDICATES A FEW STORMS BEGINNING TO
DEVELOP OVER SOUTH CENTRAL AND SOUTHEAST COLORADO.
THIS AFTERNOON AND EVENING...ANTICIPATE TWO AREAS OF THUNDERSTORM
DEVELOPMENT. THE FIRST AREA...WHERE ONLY A FEW ISOLATED STORMS ARE
POSSIBLE DUE TO A STRONG CAP...IS LOCATED ALONG THE TROUGH AXIS
LOCATED OVER PRIMARILY NORTHWEST KANSAS. THE SECOND AREA OF
DEVELOPMENT...WHICH POSSESSES A MUCH BETTER CHANCE FOR
PRECIPITATION...HAS BEGUN OVER COLORADO. LATEST HIGH RESOLUTION
GUIDANCE INDICATES THE COLORADO STORMS WILL MOVE NORTHEAST INTO THE
REGION THIS EVENING AFTER CONSOLIDATION INTO AN MCS. MOST STORMS
SHOULD MOVE OUT BY MIDNIGHT WITH QUIET WEATHER RETURNING BEHIND THE
STORMS.
AS FOR SEVERE WEATHER CHANCES...ISOLATED CONVECTION OVER NORTHWEST
KANSAS POSES THE HIGHEST THREAT FOR SEVERE WEATHER. AN ATMOSPHERE
CHARACTERIZED BY SBCAPE OF 1500-2500 J/KG...850-500 MB LAPSE RATES
OF 6.5-7.5 C/KM...AND DCAPE POTENTIALLY AS HIGH AS 1000 J/KG WILL
PROVIDE A FAVORABLE ATMOSPHERE FOR SEVERE THUNDERSTORMS. HOWEVER...
WIND SHEAR PARAMETERS DEFINITELY LEAVE SOMETHING TO BE DESIRED AS
0-6 KM BULK SHEAR IS PROJECTED TO BE A MEAGER 20-30 KTS WITH 0-3 KM
HELICITY REACHING A MAXIMUM OF 125 M2/S2. THEREFORE...FEEL THAT THE
PRIMARY SEVERE WEATHER THREAT WILL OCCUR WITH ANY ISOLATED
CONVECTION THAT DEVELOPS THIS AFTERNOON OVER NORTHWEST KANSAS. THE
PRIMARY THREATS WITH THESE MORE PULSE-LIKE STORMS WILL BE LARGE HAIL
AND DAMAGING WINDS. PRECIPITABLE WATER READINGS PROJECTED IN THE
1.50"-1.75" RANGE INDICATE A HEAVY RAIN THREAT. STORMS THIS EVENING
SHOULD BE MORE PROGRESSIVE IN NATURE AS A RESULT OF COLD POOL
FORMATION BUT ISOLATED STORMS THIS AFTERNOON MAY MOVE AT A SNAILS
PACE. THEREFORE...CAN NOT RULE OUT AN INSTANCE OF FLASH FLOODING.
FOR TOMORROW...STORMS SHOULD NOT BE AS NUMEROUS DUE TO LACK OF A
MORE NOTICEABLE SHORTWAVE TROUGH AND RIDGE INTENSIFICATION.
THUNDERSTORMS MAY DEVELOP ALONG SURFACE TROUGH AND ANY REMNANT
OUTFLOW BOUNDARIES OVER NORTHWEST KANSAS AND EAST CENTRAL COLORADO.
DRY AIR ADVECTION SHOULD PREVENT HIGHER ATMOSPHERIC INSTABILITY FROM
BEING REALIZED SO DO NOT ANTICIPATE MUCH OF A SEVERE WEATHER THREAT.
ALSO...WITH LESS CLOUD COVER AND THE RIDGE BUILDING...HOTTER
TEMPERATURES ARE ASSURED. FORECAST HIGHS TOMORROW ARE GENERALLY
3-5 DEGREES WARMER THAN TODAY IN MOST LOCATIONS. DRY AIR ADVECTION
SHOULD LEAD TO A DROP IN DEWPOINT TEMPERATURES. THIS SHOULD PREVENT
HEAT INDEX READINGS FROM REACHING THE 105 DEGREE CRITERIA FOR A HEAT
ADVISORY.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 220 AM MDT THU JUL 16 2015
THE GFS AND EUROPEAN ARE IN BETTER AGREEMENT THAN YESTERDAY FOR THE
FORECAST PERIOD. THERE ARE STILL SOME UNCERTAINTIES WITH PRECIPITATION
TIMING DUE TO THE DIFFERENCES BETWEEN THE MODELS...BUT THERE IS
MOISTURE BEING PUMPED UP INTO THE CWA FROM THE SOUTHWESTERN MONSOON...
WHICH WILL AID IN PRECIPITATION CHANCES. BEST CHANCES FOR STORMS LOOK
TO BE SUNDAY AND TUESDAY/WEDNESDAY WITH 700 MB SHORTWAVES PUSHING
THROUGH THE CWA...AS WELL AS A FRONTAL PASSAGE SUNDAY AND A STRONGER
SHORTWAVE TROUGH LATER IN THE WEEK.
BOTH MODELS HAVE A STRONG SOUTHEASTERN RIDGE THAT WILL START TO PUSH
WEST AS THE WEEK PROGRESSES. THIS RIDGE IS A BIG FACTOR ON HOW EACH
MODEL HANDLES PRECIPITATION. THE GFS STILL HAS A NORTHWESTERN TROUGH
THAT LINGERS A LITTLE LONGER ON SUNDAY THAN THE TROUGH IN THE
EUROPEAN...WHICH HAS THE RIDGE A LITTLE STRONGER THAT PUSHES THE TROUGH
MORE NORTHERLY AND INTO CANADA.
AS FAR AS SUNDAY GOES...THE GFS HAS STRONG BULK SHEARING AROUND 60 KTS
FROM 12Z SUN TO 00Z MON. THE SURFACE CAPES ARE NOT SIGNIFICANT...BUT
THE EUROPEAN HAS SURFACE CAPES AROUND 2000 J/KG BUT NO BULK SHEARING
DURING THE SAME TIME FRAME. FOR WEDNESDAY AT 00Z THE GFS HAS BULK
SHEARING AROUND 50 KTS AND SURFACE CAPES AROUND 2300 J/KG. THE EUROPEAN
DOES NOT HAVE SIGNIFICANT VALUES FOR SURFACE CAPES OR BULK SHEARING AT
00Z WED...BUT SURFACE CAPES ARE SOMEWHAT IMPRESSIVE TUES AT 18Z. ALONG
WITH THE SHORTWAVES AND MOISTURE MOVING INTO THE CWA...TIMING IS
QUESTIONABLE FOR PRECIPITATION BUT IS MORE PROBABLE THESE DAYS.
WITH A COLD FRONT MOVING THROUGH THE CWA SATURDAY NIGHT/SUNDAY
MORNING...HIGH TEMPERATURES WILL BE COOLER IN THE HIGH 70S TO HIGH 80S
SUNDAY. THERE WILL BE A SLIGHT INCREASE IN HIGH TEMPERATURES MONDAY
THROUGH WEDNESDAY BUT TEMPERATURES WILL STILL BE IN THE HIGH 80S TO LOW
90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1134 PM MDT WED JUL 15 2015
A COMPLEX OF THUNDERSTORMS MOVING ACROSS THE TRI STATE AREA WILL
AFFECT THE TERMINALS FOR THE NEXT 1-2 HOURS BRINGING GUSTY WINDS
AND HEAVY RAINFALL AT TIMES. THUNDERSTORMS WILL AFFECT KGLD
DIRECTLY...BUT STORMS SHOULD MISS KMCK AND REMAIN IN THE VICINITY.
ONCE THE STORMS MOVE PAST THE TERMINALS EARLY IN THE PERIOD...VFR
CEILINGS AND VISIBILITIES ARE EXPECTED FOR THE REST OF THE PERIOD
FOR BOTH KMCK AND KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MK
SHORT TERM...RRH
LONG TERM...CLT
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
219 AM MDT THU JUL 16 2015
.UPDATE...
ISSUED AT 846 PM MDT WED JUL 15 2015
UPDATED THE FORECAST TO INCORPORATE LATEST THUNDERSTORM MOVEMENT
AND COVERAGE TRENDS. LATEST HRRR RUN SEEMS TO BE CAPTURING THE
MOVEMENT AND TIMING OF THUNDERSTORMS ACROSS EASTERN COLORADO
FAIRLY WELL AT THE MOMENT...SO DECIDED TO INCORPORATE THE SOLUTION
INTO THE FORECAST. THE CURRENT LINE OF STORMS ACROSS EASTERN
COLORADO SHOULD SHIFT EASTWARD AND HOLD TOGETHER FOR NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA IN THE NEXT FEW HOURS AND LAST
THROUGH ABOUT 3 MDT/4 CDT BEFORE EXITING THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 142 PM MDT WED JUL 15 2015
AS OF 2 PM CDT...1 PM MDT...SKIES ACROSS THE TRI-STATE REGION PARTLY
TO MOSTLY CLOUD WITH LOW DAYTIME CUMULUS PRESENT. TEMPERATURES ARE
IN THE 80S TO NEAR 90 IN A FEW PLACES. WINDS ARE FAIRLY LIGHT AND
VARIABLE. AT THE SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM
EASTERN NEBRASKA...ACROSS THE TRI-STATE REGION AND SOUTH INTO
EASTERN NEW MEXICO. THIS HAS LED TO THE LIGHT WINDS THIS AFTERNOON.
ALOFT...A HIGH PRESSURE RIDGE IS CENTERED OVER TEXAS. A FEW SUBTLE
MONSOON-TYPE IMPULSES WERE MOVING NORTH ON THE WESTERN RIDGE
PERIPHERY. ONE IN PARTICULAR IS LOCATED OVER NEW MEXICO...HEADING
NORTH-NORTHEAST INTO SOUTHEAST COLORADO. IT IS THIS SHORTWAVE TROUGH
THAT IS LIKELY THE FORCING FOR THIS EVENING`S THUNDERSTORMS. LATEST
SATELLITE AND WSR-88D RADAR DATA INDICATES A FEW STORMS BEGINNING TO
DEVELOP OVER SOUTH CENTRAL AND SOUTHEAST COLORADO.
THIS AFTERNOON AND EVENING...ANTICIPATE TWO AREAS OF THUNDERSTORM
DEVELOPMENT. THE FIRST AREA...WHERE ONLY A FEW ISOLATED STORMS ARE
POSSIBLE DUE TO A STRONG CAP...IS LOCATED ALONG THE TROUGH AXIS
LOCATED OVER PRIMARILY NORTHWEST KANSAS. THE SECOND AREA OF
DEVELOPMENT...WHICH POSSESSES A MUCH BETTER CHANCE FOR
PRECIPITATION...HAS BEGUN OVER COLORADO. LATEST HIGH RESOLUTION
GUIDANCE INDICATES THE COLORADO STORMS WILL MOVE NORTHEAST INTO THE
REGION THIS EVENING AFTER CONSOLIDATION INTO AN MCS. MOST STORMS
SHOULD MOVE OUT BY MIDNIGHT WITH QUIET WEATHER RETURNING BEHIND THE
STORMS.
AS FOR SEVERE WEATHER CHANCES...ISOLATED CONVECTION OVER NORTHWEST
KANSAS POSES THE HIGHEST THREAT FOR SEVERE WEATHER. AN ATMOSPHERE
CHARACTERIZED BY SBCAPE OF 1500-2500 J/KG...850-500 MB LAPSE RATES
OF 6.5-7.5 C/KM...AND DCAPE POTENTIALLY AS HIGH AS 1000 J/KG WILL
PROVIDE A FAVORABLE ATMOSPHERE FOR SEVERE THUNDERSTORMS. HOWEVER...
WIND SHEAR PARAMETERS DEFINITELY LEAVE SOMETHING TO BE DESIRED AS
0-6 KM BULK SHEAR IS PROJECTED TO BE A MEAGER 20-30 KTS WITH 0-3 KM
HELICITY REACHING A MAXIMUM OF 125 M2/S2. THEREFORE...FEEL THAT THE
PRIMARY SEVERE WEATHER THREAT WILL OCCUR WITH ANY ISOLATED
CONVECTION THAT DEVELOPS THIS AFTERNOON OVER NORTHWEST KANSAS. THE
PRIMARY THREATS WITH THESE MORE PULSE-LIKE STORMS WILL BE LARGE HAIL
AND DAMAGING WINDS. PRECIPITABLE WATER READINGS PROJECTED IN THE
1.50"-1.75" RANGE INDICATE A HEAVY RAIN THREAT. STORMS THIS EVENING
SHOULD BE MORE PROGRESSIVE IN NATURE AS A RESULT OF COLD POOL
FORMATION BUT ISOLATED STORMS THIS AFTERNOON MAY MOVE AT A SNAILS
PACE. THEREFORE...CAN NOT RULE OUT AN INSTANCE OF FLASH FLOODING.
FOR TOMORROW...STORMS SHOULD NOT BE AS NUMEROUS DUE TO LACK OF A
MORE NOTICEABLE SHORTWAVE TROUGH AND RIDGE INTENSIFICATION.
THUNDERSTORMS MAY DEVELOP ALONG SURFACE TROUGH AND ANY REMNANT
OUTFLOW BOUNDARIES OVER NORTHWEST KANSAS AND EAST CENTRAL COLORADO.
DRY AIR ADVECTION SHOULD PREVENT HIGHER ATMOSPHERIC INSTABILITY FROM
BEING REALIZED SO DO NOT ANTICIPATE MUCH OF A SEVERE WEATHER THREAT.
ALSO...WITH LESS CLOUD COVER AND THE RIDGE BUILDING...HOTTER
TEMPERATURES ARE ASSURED. FORECAST HIGHS TOMORROW ARE GENERALLY
3-5 DEGREES WARMER THAN TODAY IN MOST LOCATIONS. DRY AIR ADVECTION
SHOULD LEAD TO A DROP IN DEWPOINT TEMPERATURES. THIS SHOULD PREVENT
HEAT INDEX READINGS FROM REACHING THE 105 DEGREE CRITERIA FOR A HEAT
ADVISORY.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 218 AM MDT THU
JUL 16 2015
THE GFS AND EUROPEAN ARE IN BETTER AGREEMENT THAN YESTERDAY FOR THE
FORECAST PERIOD. THERE ARE STILL SOME UNCERTAINTIES WITH PRECIPITATION
TIMING DUE TO THE DIFFERENCES BETWEEN THE MODELS...BUT THERE IS
MOISTURE BEING PUMPED UP INTO THE CWA FROM THE SOUTHWESTERN MONSOON...
WHICH WILL AID IN PRECIPITATION CHANCES. BEST CHANCES FOR STORMS LOOK
TO BE SUNDAY AND TUESDAY/WEDNESDAY WITH 700 MB SHORTWAVES PUSHING
THROUGH THE CWA...AS WELL AS A FRONTAL PASSAGE SUNDAY AND A STRONGER
SHORTWAVE TROUGH LATER IN THE WEEK.
BOTH MODELS HAVE A STRONG SOUTHEASTERN RIDGE THAT WILL START TO PUSH
WEST AS THE WEEK PROGRESSES. THIS RIDGE IS A BIG FACTOR ON HOW EACH
MODEL HANDLES PRECIPITATION. THE GFS STILL HAS A NORTHWESTERN TROUGH
THAT LINGERS A LITTLE LONGER ON SUNDAY THAN THE TROUGH IN THE
EUROPEAN...WHICH HAS THE RIDGE A LITTLE STRONGER THAT PUSHES THE TROUGH
MORE NORTHERLY AND INTO CANADA.
AS FAR AS SUNDAY GOES...THE GFS HAS STRONG BULK SHEARING AROUND 60 KTS
FROM 12Z SUN TO 00Z MON. THE SURFACE CAPES ARE NOT SIGNIFICANT...BUT
THE EUROPEAN HAS SURFACE CAPES AROUND 2000 J/KG BUT NO BULK SHEARING
DURING THE SAME TIME FRAME. FOR WEDNESDAY AT 00Z THE GFS HAS BULK
SHEARING AROUND 50 KTS AND SURFACE CAPES AROUND 2300 J/KG. THE EUROPEAN
DOES NOT HAVE SIGNIFICANT VALUES FOR SURFACE CAPES OR BULK SHEARING AT
00Z WED...BUT SURFACE CAPES ARE SOMEWHAT IMPRESSIVE TUES AT 18Z. ALONG
WITH THE SHORTWAVES AND MOISTURE MOVING INTO THE CWA...TIMING IS
QUESTIONABLE FOR PRECIPITATION BUT IS MORE PROBABLE THESE DAYS.
WITH A COLD FRONT MOVING THROUGH THE CWA SATURDAY NIGHT/SUNDAY
MORNING...HIGH TEMPERATURES WILL BE COOLER IN THE HIGH 70S TO HIGH 80S
SUNDAY. THERE WILL BE A SLIGHT INCREASE IN HIGH TEMPERATURES MONDAY
THROUGH WEDNESDAY BUT TEMPERATURES WILL STILL BE IN THE HIGH 80S TO LOW
90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1134 PM MDT WED JUL 15 2015
A COMPLEX OF THUNDERSTORMS MOVING ACROSS THE TRI STATE AREA WILL
AFFECT THE TERMINALS FOR THE NEXT 1-2 HOURS BRINGING GUSTY WINDS
AND HEAVY RAINFALL AT TIMES. THUNDERSTORMS WILL AFFECT KGLD
DIRECTLY...BUT STORMS SHOULD MISS KMCK AND REMAIN IN THE VICINITY.
ONCE THE STORMS MOVE PAST THE TERMINALS EARLY IN THE PERIOD...VFR
CEILINGS AND VISIBILITIES ARE EXPECTED FOR THE REST OF THE PERIOD
FOR BOTH KMCK AND KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MK
SHORT TERM...RRH
LONG TERM...CLT
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1144 PM MDT WED JUL 15 2015
.UPDATE...
ISSUED AT 846 PM MDT WED JUL 15 2015
UPDATED THE FORECAST TO INCORPORATE LATEST THUNDERSTORM MOVEMENT
AND COVERAGE TRENDS. LATEST HRRR RUN SEEMS TO BE CAPTURING THE
MOVEMENT AND TIMING OF THUNDERSTORMS ACROSS EASTERN COLORADO
FAIRLY WELL AT THE MOMENT...SO DECIDED TO INCORPORATE THE SOLUTION
INTO THE FORECAST. THE CURRENT LINE OF STORMS ACROSS EASTERN
COLORADO SHOULD SHIFT EASTWARD AND HOLD TOGETHER FOR NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA IN THE NEXT FEW HOURS AND LAST
THROUGH ABOUT 3 MDT/4 CDT BEFORE EXITING THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 142 PM MDT WED JUL 15 2015
AS OF 2 PM CDT...1 PM MDT...SKIES ACROSS THE TRI-STATE REGION PARTLY
TO MOSTLY CLOUD WITH LOW DAYTIME CUMULUS PRESENT. TEMPERATURES ARE
IN THE 80S TO NEAR 90 IN A FEW PLACES. WINDS ARE FAIRLY LIGHT AND
VARIABLE. AT THE SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM
EASTERN NEBRASKA...ACROSS THE TRI-STATE REGION AND SOUTH INTO
EASTERN NEW MEXICO. THIS HAS LED TO THE LIGHT WINDS THIS AFTERNOON.
ALOFT...A HIGH PRESSURE RIDGE IS CENTERED OVER TEXAS. A FEW SUBTLE
MONSOON-TYPE IMPULSES WERE MOVING NORTH ON THE WESTERN RIDGE
PERIPHERY. ONE IN PARTICULAR IS LOCATED OVER NEW MEXICO...HEADING
NORTH-NORTHEAST INTO SOUTHEAST COLORADO. IT IS THIS SHORTWAVE TROUGH
THAT IS LIKELY THE FORCING FOR THIS EVENING`S THUNDERSTORMS. LATEST
SATELLITE AND WSR-88D RADAR DATA INDICATES A FEW STORMS BEGINNING TO
DEVELOP OVER SOUTH CENTRAL AND SOUTHEAST COLORADO.
THIS AFTERNOON AND EVENING...ANTICIPATE TWO AREAS OF THUNDERSTORM
DEVELOPMENT. THE FIRST AREA...WHERE ONLY A FEW ISOLATED STORMS ARE
POSSIBLE DUE TO A STRONG CAP...IS LOCATED ALONG THE TROUGH AXIS
LOCATED OVER PRIMARILY NORTHWEST KANSAS. THE SECOND AREA OF
DEVELOPMENT...WHICH POSSESSES A MUCH BETTER CHANCE FOR
PRECIPITATION...HAS BEGUN OVER COLORADO. LATEST HIGH RESOLUTION
GUIDANCE INDICATES THE COLORADO STORMS WILL MOVE NORTHEAST INTO THE
REGION THIS EVENING AFTER CONSOLIDATION INTO AN MCS. MOST STORMS
SHOULD MOVE OUT BY MIDNIGHT WITH QUIET WEATHER RETURNING BEHIND THE
STORMS.
AS FOR SEVERE WEATHER CHANCES...ISOLATED CONVECTION OVER NORTHWEST
KANSAS POSES THE HIGHEST THREAT FOR SEVERE WEATHER. AN ATMOSPHERE
CHARACTERIZED BY SBCAPE OF 1500-2500 J/KG...850-500 MB LAPSE RATES
OF 6.5-7.5 C/KM...AND DCAPE POTENTIALLY AS HIGH AS 1000 J/KG WILL
PROVIDE A FAVORABLE ATMOSPHERE FOR SEVERE THUNDERSTORMS. HOWEVER...
WIND SHEAR PARAMETERS DEFINITELY LEAVE SOMETHING TO BE DESIRED AS
0-6 KM BULK SHEAR IS PROJECTED TO BE A MEAGER 20-30 KTS WITH 0-3 KM
HELICITY REACHING A MAXIMUM OF 125 M2/S2. THEREFORE...FEEL THAT THE
PRIMARY SEVERE WEATHER THREAT WILL OCCUR WITH ANY ISOLATED
CONVECTION THAT DEVELOPS THIS AFTERNOON OVER NORTHWEST KANSAS. THE
PRIMARY THREATS WITH THESE MORE PULSE-LIKE STORMS WILL BE LARGE HAIL
AND DAMAGING WINDS. PRECIPITABLE WATER READINGS PROJECTED IN THE
1.50"-1.75" RANGE INDICATE A HEAVY RAIN THREAT. STORMS THIS EVENING
SHOULD BE MORE PROGRESSIVE IN NATURE AS A RESULT OF COLD POOL
FORMATION BUT ISOLATED STORMS THIS AFTERNOON MAY MOVE AT A SNAILS
PACE. THEREFORE...CAN NOT RULE OUT AN INSTANCE OF FLASH FLOODING.
FOR TOMORROW...STORMS SHOULD NOT BE AS NUMEROUS DUE TO LACK OF A
MORE NOTICEABLE SHORTWAVE TROUGH AND RIDGE INTENSIFICATION.
THUNDERSTORMS MAY DEVELOP ALONG SURFACE TROUGH AND ANY REMNANT
OUTFLOW BOUNDARIES OVER NORTHWEST KANSAS AND EAST CENTRAL COLORADO.
DRY AIR ADVECTION SHOULD PREVENT HIGHER ATMOSPHERIC INSTABILITY FROM
BEING REALIZED SO DO NOT ANTICIPATE MUCH OF A SEVERE WEATHER THREAT.
ALSO...WITH LESS CLOUD COVER AND THE RIDGE BUILDING...HOTTER
TEMPERATURES ARE ASSURED. FORECAST HIGHS TOMORROW ARE GENERALLY
3-5 DEGREES WARMER THAN TODAY IN MOST LOCATIONS. DRY AIR ADVECTION
SHOULD LEAD TO A DROP IN DEWPOINT TEMPERATURES. THIS SHOULD PREVENT
HEAT INDEX READINGS FROM REACHING THE 105 DEGREE CRITERIA FOR A HEAT
ADVISORY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED JUL 15 2015
MONSOON MOISTURE WILL CONTINUE TO PROVIDE THE TRI-STATE AREA WITH
DECENT LOW TO MID LEVEL MOISTURE THROUGH THE PERIOD. IT WILL BE
DIFFICULT TO TIME SMALL SCALE FEATURES THAT WOULD INTERACT WITH
THE MOISTURE TO PRODUCE THUNDERSTORMS.
THE GFS AND ECMWF ARE IN BETTER AGREEMENT THIS AFTERNOON. THEY
INDICATE A NUMBER OF 500 MB SHORT WAVE TROUGHS THAT COULD PROVIDE
AMPLE ASCENT FOR STORMS. THE MOST SIGNIFICANT SHORT WAVE TROUGH IS
PROGGED TO ARRIVE SATURDAY EVENING. THAT FEATURE WILL PUSH A COLD
FRONT ACROSS THE AREA SATURDAY NIGHT AND SUNDAY. OF ALL THE DAYS IN
THE EXTENDED PERIOD...SUNDAY LOOKS TO HAVE THE BEST CHANCE OF
STORMS DUE TO SURFACE CONVERGENCE NEAR THE FRONT. HOWEVER...ANY
SHORT WAVE TROUGH MOVING ACROSS THE AREA MIGHT BE ENOUGH TO
PRODUCE STORMS AS THE AIR MASS WILL BE MOIST AND UNSTABLE. BOTTOM
LINE...NOT A LOT OF CONFIDENCE IN THE FORECAST AND THIS IS NOTED
BY A BROAD BRUSH CONVECTIVE FORECAST FOR MOST OF THE DAYS.
TEMPERATURES WILL BE ABOVE NORMAL FRIDAY AND SATURDAY AS 850 MB
TEMPERATURES RISE TO 32 DEGREES CELSIUS. APPARENT TEMPERATURES BOTH
AFTERNOONS WILL RANGE FROM 100-105 OVER THE EASTERN
COUNTIES...NEAR HEAT ADVISORY CRITERIA. THE COLD FRONT SUNDAY WILL
DROP TEMPERATURES CONSIDERABLY UNTIL THEY REBOUND AFTER TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1134 PM MDT WED JUL 15 2015
A COMPLEX OF THUNDERSTORMS MOVING ACROSS THE TRI STATE AREA WILL
AFFECT THE TERMINALS FOR THE NEXT 1-2 HOURS BRINGING GUSTY WINDS
AND HEAVY RAINFALL AT TIMES. THUNDERSTORMS WILL AFFECT KGLD
DIRECTLY...BUT STORMS SHOULD MISS KMCK AND REMAIN IN THE VICINITY.
ONCE THE STORMS MOVE PAST THE TERMINALS EARLY IN THE PERIOD...VFR
CEILINGS AND VISIBILITIES ARE EXPECTED FOR THE REST OF THE PERIOD
FOR BOTH KMCK AND KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MK
SHORT TERM...RRH
LONG TERM...MENTZER
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GRAY ME
108 AM EDT THU JUL 16 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH WELL OFF THE COAST OVERNIGHT...INTRODUCING A
MUCH DRIER AIR MASS TO THE REGION. COOLER AIR WILL ALSO FILTER IN
FROM THE NORTH...WITH READINGS FALLING INTO THE 40S AND 50S. HIGH
PRESSURE WILL FOLLOW FOR THURSDAY AND THURSDAY NIGHT...BRINGING
QUIET WEATHER. THE HIGH WILL SHIFT OFFSHORE OVER THE WEEKEND
ALLOWING FOR A WARMER AND MORE MOIST AIRMASS TO MOVE IN...POSSIBLY
ASSOCIATED WITH SHOWERS AND THUNDERSTORMS. THIS ACTIVITY COULD
PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
108 AM...MINOR ESTF UPDATE TO REFLECT CURRENT SATELLITE TREND AND
INGEST THE LATEST MESONET INTO FIRST PERIOD GRIDS.
PREV DISC...
610 PM...MINOR ESTF UPDATE TO REFLECT CURRENT RADAR TRENDS... AND
TO INGEST THE 22Z MESONET INTO FIRST PERIOD GRIDS. SCATTERED
CONVECTION CONTINUES TO FIRE OVER EASTERN ROCKINGHAM COUNTY ALONG
CONVERGENCE ZONE...BUT EXPECT THIS ACTIVITY TO END NEXT 1 TO 2
HOURS WITH LOSS OF HEATING AND PER LATEST HRRR OUTPUT.
PREV DISC...
COLD FRONT CONTINUES ITS MARCH THRU THE FORECAST AREA...AND IS
CLEARING THE WESTERN MAINE COAST AT THIS HOUR. THE ONLY PORTION
OF THE FORECAST AREA REMAINING IN THE WARM SECTOR IS SOUTHEAST
NH...WHICH WILL ONLY BE FOR THE NEXT COUPLE OF HOURS AT MOST.
ANY REMAINING POP WILL CONFINED TO THIS AREA OF NH...WITH RAPID
DRYING FROM THE N.
DEWPOINTS ARE DROPPING INTO THE 50S AS THE DRIER AIR MASS WORKS
INTO THE REGION. AIR MASS IS SEASONABLY COOL...BUT THE CENTER OF
THE COLDEST TEMPERATURES ALOFT WILL DELAY IN ARRIVING UNTIL LATE
THURSDAY INTO FRIDAY. THUS WENT SLIGHTLY WARMER THAN GUIDANCE
TONIGHT...AS COLD ADVECTION WILL KEEP A SOMEWHAT MIXED BOUNDARY
LAYER.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE SETTLES OVER THE REGION THURSDAY AND THURSDAY NIGHT.
IT WILL BE A SPECTACULAR DAY THURSDAY...AS WARM TEMPERATURES
COMBINE WITH LOW DEWPOINTS FOR A VERY COMFORTABLE SUMMER DAY. NW
BREEZE WILL WEAKEN...ESPECIALLY LATE IN THE DAY...ALLOWING SEA
BREEZE TO PUSH INLAND LATE IN THE AFTERNOON.
WITH SKIES CLEAR AND WINDS LIGHT...TEMPERATURES WILL TUMBLE AFTER
SUNSET THURSDAY. UNDERCUT MODEL GUIDANCE...ESPECIALLY NORTHERN
VALLEYS...AS IDEAL RADIATIONAL COOLING CONDITIONS SET UP. ALSO
EXPECT VALLEY FOG TO BE MORE PREVALENT THURSDAY NIGHT...AS LACK
OF GRADIENT WILL REDUCE ANY POTENTIAL MIXING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE MOVES EAST ON FRIDAY SETTING UP RETURN SOUTHERLY
LOW LEVEL FLOW OVER THE REGION. THIS WILL BRING IN SLIGHTLY WARMER
AND MORE HUMID AIR FOR FRIDAY THOUGH IT SHOULD REMAIN A DRY DAY.
A SHORTWAVE TROUGH MOVING QUICKLY THROUGH SOUTHERN CANADA WILL
SEND A WEAK SURFACE LOW PRESSURE SYSTEM THROUGH THE NORTHERN GREAT
LAKES AND EASTWARD ALONG THE CANADIAN BORDER INTO MAINE BY
SATURDAY. EXPECT SHOWERS ASSOCIATED WITH THIS SYSTEM TO ARRIVE AS
EARLY AS FRIDAY NIGHT OR EARLY SATURDAY MORNING. THE BEST CHANCE
OF RAIN AND THE HEAVIEST PRECIPITATION WILL BE IN NORTHERN AREAS
WHERE A WARM FRONT MAY BECOME ESTABLISHED. SOUTH OF THIS WARM
FRONT... LOW LEVEL MOISTURE MAY COMBINE WITH DECREASING
TEMPERATURES ALOFT WITHIN THE SHORTWAVE TROUGH TO PRODUCE DIURNAL
INSTABILITY FOR THUNDERSTORMS MAINLY OVER NEW HAMPSHIRE. WIND
SHEAR IS A BIT MARGINAL FOR SEVERE THUNDERSTORMS BUT THEY CANNOT
BE RULED OUT.
SURFACE LOW WILL DROP SOUTHEAST INTO THE GULF OF MAINE BY SUNDAY
MORNING AS UPPER LEVEL RIDGING BUILDS TO THE WEST AND NORTH. COULD
STILL SEE A FEW SHOWERS ON SUNDAY AS THE LOW LINGERS NEARBY
ESPECIALLY OVER COASTAL MAINE. TEMPERATURES REACH THE 70S BUT WILL
RISE INTO THE 80S OVER SOUTHERN NEW HAMPSHIRE FURTHER AWAY FROM
THE MARITIME AIR ASSOCIATED WITH THE OFFSHORE LOW.
AS LOW PRESSURE WEAKENS IT IS ALSO SHOVED FURTHER SOUTHEAST BY A
BUILDING SURFACE HIGH OVER THE CANADIAN MARITIMES. THIS WILL SET
UP AN EASTERLY FLOW OVER MAINE AND EASTERN NEW HAMPSHIRE ON
MONDAY... WITH LOW CLOUDS BECOMING LIKELY ALONG WITH A CHANCE OF
DRIZZLE OR LIGHT SHOWERS. TEMPERATURES ARE CURRENTLY FORECAST TO
REACH THE 70S THOUGH THIS MIGHT BE A LITTLE ON THE HIGH SIDE IF
MOIST EASTERLY FLOW KEEPS THE COOL AIR AND LOW CLOUDS IN MOST OF
THE DAY.
THE NEXT LARGER SCALE FRONTAL SYSTEM MOVES IN FROM THE WEST ON
TUESDAY... WITH ANOTHER ROUND OF SHOWERS EXPECTED AS IT DOES SO.
THERE ARE SOME TIMING DIFFERENCES AMONG THE MODELS WHICH GIVE SOME
UNCERTAINTY. IF THE TIMING LINES UP RIGHT... THERE COULD BE
THUNDERSTORMS FORMING ALONG AND AHEAD OF THE FRONT ON TUESDAY.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND COULD LEAD TO A
PERIOD OF DRIER WEATHER.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
SHORT TERM...HIGH PRESSURE BUILDS IN TONIGHT...PROVIDING QUIET
WEATHER THRU THURSDAY NIGHT. ONLY POTENTIAL RESTRICTIONS WILL BE
IN VALLEY FOG. MODEL GUIDANCE SUGGESTS LEB AND HIE WILL DROP TO
IFR OR LOWER TONIGHT. HOWEVER...FEEL THAT AS COOLER AIR MASS
ADVECTS IN THE MODELED COOL TEMPERATURES AND FOG WILL HAVE A
HARDER TIME DEVELOPING. BEST CHANCE FOR VALLEY FOG APPEARS TO BE
THURSDAY NIGHT AND FRIDAY MORNING...AS HIGH PRESSURE SETTLES
OVERHEAD AND WINDS GO CALM.
LONG TERM...SHOULD SEE VFR CONDITIONS THROUGH FRIDAY. SOME SHOWERS
BEGIN ARRIVING LATE FRIDAY NIGHT AND COULD BRING MVFR OR IFR
CONDITIONS AT TIMES THROUGH SATURDAY NIGHT. GRADUALLY IMPROVING
CONDITIONS ON SUNDAY. AN EASTERLY FLOW ON MONDAY MAY BRING IN SOME
LOWER CLOUDS AND FOG OR DRIZZLE TO LOCATIONS EAST OF THE
MOUNTAINS.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA THROUGH THURSDAY NIGHT...ALTHOUGH SEAS MAY APPROACH 5 FT
ON THE OUTER WATERS TONIGHT...MAINLY DUE TO SWELL.
LONG TERM...A PROLONGED SOUTHERLY FLOW MAY ALLOW WAVE HEIGHTS TO
INCREASE TO 5 FEET OR HIGHER MAINLY OVER THE EASTERN WATERS BY
SATURDAY NIGHT. THIS SHOULD DIMINISH WITH TIME ON SUNDAY AS WEAK
LOW PRESSURE MOVES SOUTHEAST THROUGH THE GULF OF MAINE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
646 AM EDT THU JUL 16 2015
.SYNOPSIS...
DRY CONDITIONS AND SLIGHTLY BELOW NORMAL TEMPERATURES TODAY AS HIGH
PRESSURE BUILDS IN FROM THE NORTH. HIGH PRESSURE SLIDES OFF THE
COAST FRIDAY. A WARM FRONT LIFTS THROUGH THE REGION SATURDAY...WITH
CHANCES FOR SHOWERS AND THUNDERSTORMS RETURNING. THE NEXT COLD FRONT
REACHES THE MID ATLANTIC EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT HAS PUSHED SOUTH OF THE AREA EARLY THIS MORNING AS HIGH
PRESSURE BUILDS IN FROM THE NORTHWEST. SHORTWAVE VISIBLE ON EARLY
MORNING GOES WV IMAGERY CURRENTLY DROPPING OVER THE REGION. RAP
GUIDANCE PICKING UP ON THE ENERGY WELL...DROPPING IT OVER ERN VA
ATTM. REMNANT MOISTURE ALONG THE COAST WITH ADDED LOW-LEVEL
CONVERGENCE HAS PRODUCED AN AREA OF SHOWERS OVER THE LOWER BAY AND
EXTREME SE VA/NE NC. RAP GUIDANCE INDICATES THAT THE SHOWERS WILL
DISSIPATE OVER LAND AS THE LOW LEVELS STABILIZE AND MOISTURE PUSHES
OFFSHORE. HAVE MAINTAINED ISOLATED TO SCATTERED SHOWERS THRU 7 AM.
OTHERWISE...CLOUDY CONDITIONS PERSIST ALONG THE COAST WITH A MOSTLY
CLEAR SKY INLAND.
FOR TODAY...TROUGH AXIS PUSHES OFFSHORE WITH FLOW ALOFT BECOMING
NWLY. THIS WILL HELP DRY THE MID-UPPER LEVELS...WITH PWATS PROGGED
TO DROP AOB 1 INCH. SFC WINDS BECOME NNE AS HIGH PRESSURE BUILDS
INTO NEW ENGLAND...RIDGING SWWD INTO THE LOCAL AREA. DRY CONDITIONS
ARE EXPECTED. LOWER THICKNESSES COMPARED TO 24 HRS AGO AND H85 TEMPS
AROUND 15-17C WILL TRANSLATE TO TEMPS IN THE LOW TO MID 80S. ONSHORE
FLOW WILL RESULT IN TEMPS AROUND 80 NEAR THE COAST. A PARTLY CLOUDY
SKY IS EXPECTED OVER THE ERN HALF OF THE LOCAL AREA AS BUFR
SOUNDINGS INDICATE HIGH RH VALUES AT THE BASE OF THE SUBSIDENCE
INVERSION. MOSTLY SUNNY SKIES EXPECTED WRN HALF.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
CONTINUED DRY WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES TONIGHT AS
HIGH PRESSURE REMAINS RIDGED OVER THE LOCAL AREA. LOWS GENERALLY IN
THE LOW TO MID 60S INLAND TO UPPER 60S SE COUNTIES. HIGH PRESSURE
SLIDES OFF THE NE AND MID-ATLANTIC COASTS FRIDAY. HIGH PRESSURE
ALOFT BUILDS EWD OVER THE SRN PLAINS INTO THE GULF
STATES...RESULTING IN INCREASING HEIGHTS OVER THE MID-ATLANTIC
REGION. THICKNESSES REBOUND FRI...AS H85 TEMPS WARM TO 18-20C. THIS
TRANSLATES TO HIGHS IN THE MID-UPPER 80S INLAND...BUT REMAINING
COOLER NEAR THE COAST THANKS TO ONSHORE FLOW. WHILE MOISTURE RETURNS
TO THE REGION...LACK OF APPRECIABLE FORCING AND WARM TEMPS ALOFT
WILL KEEP MEASURABLE PRECIP CONFINED TO UPSLOPE
SHOWERS/THUNDERSTORMS OVER THE CENTRAL APPALACHIANS. WILL MAINTAIN
DRY FORECAST FRI WITH A PARTLY CLOUDY SKY.
DRY FORECAST CONTINUES FRI NIGHT AS UPPER/SFC HIGH PRESSURE REMAINS
OVER THE REGION. A WEAK AREA OF LOW PRESSURE LIFTS INTO NEW ENGLAND
SAT MORNING...PRODUCING PRESSURE FALLS ON THE LEE SIDE OF THE
MOUNTAINS. ADDED LOW-LEVEL CONVERGENCE TO GO ALONG WITH
MOIST/UNSTABLE AIR MASS (PWATS AROUND 2 INCHES) AND PERTURBATIONS IN
NWLY FLOW ALOFT WILL RESULT IN SCATTERED SHOWERS/THUNDERSTORMS SAT
AFTERNOON AND EVENING. WARMING TREND CONTINUES...WITH HIGHS IN THE
LOW TO MID 90S (SLIGHTLY COOLER ALONG THE COAST).
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BUILDING HEIGHTS ALOFT OVER THE WEEKEND/EARLY NEXT WEEK AS BROAD
UPPER RIDGE SLIDES EAST FROM THE PLAINS...AND SFC HIGH PRESSURE
LINGERS ALONG THE EASTERN SEABOARD/JUST OFFSHORE. THIS WILL
BRING GRADUALLY INCREASING TEMPS/RH THROUGH THE PERIOD AS RETURN
(SSW) FLOW SETS UP LATE IN THE WEEKEND INTO EARLY NEXT WEEK. PCPN
WILL BECOMES A BIT MORE DIURNALLY DRIVEN IN NATURE DURING THIS
PERIOD, WITH THE WEAK LLVL HEIGHT FALLS ALLOWING A LEE TROUGH TO
DEVELOP TO THE WEST...WHICH SHOULD BE THE FOCUS FOR SOME SCT
SHRAS EACH AFTN SUN/MON (BEST FORCING REMAINS TO OUR NNW BOTH
DAYS).
BEST RAIN CHANCES FOR THE PERIOD COME ON TUESDAY AS SFC BOUNDARY
APPROACHES FROM THE WEST AND UPPER LEVEL PATTERN RETURNING TO A
FAMILIAR SETUP AS TROUGH DIGS SOUTH FROM THE GREAT LAKES REGION
TOWARDS THE LOCAL AREA. HIGH TEMPERATURES IN UPPER 80S TO LOW 90S
SUNDAY...INCREASING INTO THE MID 90S MONDAY AND TUESDAY. EARLY
MORNING LOWS GENERALLY 70-75F.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR CNDTNS XPCTD...HOWEVER DATA SUPPORTS A BKN TO OCNL OVC SC
DECK BTWN 4-5K FT ALONG AND EAST OF THE CHES BAY THROUGH 00Z.
CHALLENGING FORECAST AFTER 00Z AS MODELS OFFER UP DIFFERENT SOLNS
WRT CLOUD COVERAGE ALONG THE COAST. NAM MOST AGGRESSIVE WITH EVEN
SOME FOG DVLPNG AFTR MIDNIGHT WHILE THE GFS SCATTERS OUT THE SC
CLOUD DECK WITH PTCHY FOG DVLPNG. WENT WITH A BLEND FOR THE 12Z
ISSUANCE AND SCT OUT THE CLOUD DECK ACROSS SERN TAF SITES BUT KEPT
A BKN CLOUD DECK AT SBY THROUGH 06Z. PTCHY FOG PSBL...BUT CONFIDENCE
NOT HIGH ENUF TO PUT IN FCST ATTM.
OUTLOOK...DRY WEATHER XPCTD FRIDAY. HIGH PRESSURE MOVES OFFSHORE
SATURDAY THROUGH TUESDAY RESULTING IN INCREASING HUMIDITY AND A
LOW CHC OF DIURNAL CONVECTION EACH DAY. HIGHEST CHANCE MONDAY.
&&
.MARINE...
NRLY SURGE BEHIND COLD FRONT CAME IN RTHR QUICK WITH WINDS BEHIND
LINE OF SHWRS / CD FRNT GUSTING BTWN 20-25 KTS OVR THE SRN CHES BAY.
SURGE PROGGED TO CONT FOR NEXT SVRL HRS WITH GUSTS TO 20 KTS SO WILL
KEEP SCA FOR CHES BAY GOING THRU 14Z. SCA`S ACROSS THE CSTL WTRS
LOOKING MARGINAL AND MAINLY FOR SEAS BLDG TO 5 FT OUT NR 20 NM.
WINDS / SEAS ALL SUBSIDE BLO SCA LEVELS THIS EVENING AS THE GRDNT
RELAXES. NE FLOW BECOMES E FRI THEN S FRI NIGHT THRU SAT AS HIGH PRS
MOVES OFF NEW ENDLAND COAST. WINDS/SEAS REMAIN BLO SCA LEVELS. SWLY
FLOW XPCTD SUN AND MON WITH CHCS FOR DIURNAL CONVECTION EACH DAY.
MODERATE RIP CURRENT RISK TODAY DUE TO ONSHORE FLOW WITH SURF ZONE
WAVES BTWN 3-4 FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
ANZ630>632.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ650-
652-654-656-658.
&&
$$
SYNOPSIS...SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...MAM
AVIATION...MPR
MARINE...MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
352 AM EDT THU JUL 16 2015
.SYNOPSIS...
DRY CONDITIONS AND SLIGHTLY BELOW NORMAL TEMPERATURES TODAY AS HIGH
PRESSURE BUILDS IN FROM THE NORTH. HIGH PRESSURE SLIDES OFF THE
COAST FRIDAY. A WARM FRONT LIFTS THROUGH THE REGION SATURDAY...WITH
CHANCES FOR SHOWERS AND THUNDERSTORMS RETURNING. THE NEXT COLD FRONT
REACHES THE MID ATLANTIC EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT HAS PUSHED SOUTH OF THE AREA EARLY THIS MORNING AS HIGH
PRESSURE BUILDS IN FROM THE NORTHWEST. SHORTWAVE VISIBLE ON EARLY
MORNING GOES WV IMAGERY CURRENTLY DROPPING OVER THE REGION. RAP
GUIDANCE PICKING UP ON THE ENERGY WELL...DROPPING IT OVER ERN VA
ATTM. REMNANT MOISTURE ALONG THE COAST WITH ADDED LOW-LEVEL
CONVERGENCE HAS PRODUCED AN AREA OF SHOWERS OVER THE LOWER BAY AND
EXTREME SE VA/NE NC. RAP GUIDANCE INDICATES THAT THE SHOWERS WILL
DISSIPATE OVER LAND AS THE LOW LEVELS STABILIZE AND MOISTURE PUSHES
OFFSHORE. HAVE MAINTAINED ISOLATED TO SCATTERED SHOWERS THRU 7 AM.
OTHERWISE...CLOUDY CONDITIONS PERSIST ALONG THE COAST WITH A MOSTLY
CLEAR SKY INLAND.
FOR TODAY...TROUGH AXIS PUSHES OFFSHORE WITH FLOW ALOFT BECOMING
NWLY. THIS WILL HELP DRY THE MID-UPPER LEVELS...WITH PWATS PROGGED
TO DROP AOB 1 INCH. SFC WINDS BECOME NNE AS HIGH PRESSURE BUILDS
INTO NEW ENGLAND...RIDGING SWWD INTO THE LOCAL AREA. DRY CONDITIONS
ARE EXPECTED. LOWER THICKNESSES COMPARED TO 24 HRS AGO AND H85 TEMPS
AROUND 15-17C WILL TRANSLATE TO TEMPS IN THE LOW TO MID 80S. ONSHORE
FLOW WILL RESULT IN TEMPS AROUND 80 NEAR THE COAST. A PARTLY CLOUDY
SKY IS EXPECTED OVER THE ERN HALF OF THE LOCAL AREA AS BUFR
SOUNDINGS INDICATE HIGH RH VALUES AT THE BASE OF THE SUBSIDENCE
INVERSION. MOSTLY SUNNY SKIES EXPECTED WRN HALF.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
CONTINUED DRY WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES TONIGHT AS
HIGH PRESSURE REMAINS RIDGED OVER THE LOCAL AREA. LOWS GENERALLY IN
THE LOW TO MID 60S INLAND TO UPPER 60S SE COUNTIES. HIGH PRESSURE
SLIDES OFF THE NE AND MID-ATLANTIC COASTS FRIDAY. HIGH PRESSURE
ALOFT BUILDS EWD OVER THE SRN PLAINS INTO THE GULF
STATES...RESULTING IN INCREASING HEIGHTS OVER THE MID-ATLANTIC
REGION. THICKNESSES REBOUND FRI...AS H85 TEMPS WARM TO 18-20C. THIS
TRANSLATES TO HIGHS IN THE MID-UPPER 80S INLAND...BUT REMAINING
COOLER NEAR THE COAST THANKS TO ONSHORE FLOW. WHILE MOISTURE RETURNS
TO THE REGION...LACK OF APPRECIABLE FORCING AND WARM TEMPS ALOFT
WILL KEEP MEASURABLE PRECIP CONFINED TO UPSLOPE
SHOWERS/THUNDERSTORMS OVER THE CENTRAL APPALACHIANS. WILL MAINTAIN
DRY FORECAST FRI WITH A PARTLY CLOUDY SKY.
DRY FORECAST CONTINUES FRI NIGHT AS UPPER/SFC HIGH PRESSURE REMAINS
OVER THE REGION. A WEAK AREA OF LOW PRESSURE LIFTS INTO NEW ENGLAND
SAT MORNING...PRODUCING PRESSURE FALLS ON THE LEE SIDE OF THE
MOUNTAINS. ADDED LOW-LEVEL CONVERGENCE TO GO ALONG WITH
MOIST/UNSTABLE AIR MASS (PWATS AROUND 2 INCHES) AND PERTURBATIONS IN
NWLY FLOW ALOFT WILL RESULT IN SCATTERED SHOWERS/THUNDERSTORMS SAT
AFTERNOON AND EVENING. WARMING TREND CONTINUES...WITH HIGHS IN THE
LOW TO MID 90S (SLIGHTLY COOLER ALONG THE COAST).
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BUILDING HEIGHTS ALOFT OVER THE WEEKEND/EARLY NEXT WEEK AS BROAD
UPPER RIDGE SLIDES EAST FROM THE PLAINS...AND SFC HIGH PRESSURE
LINGERS ALONG THE EASTERN SEABOARD/JUST OFFSHORE. THIS WILL
BRING GRADUALLY INCREASING TEMPS/RH THROUGH THE PERIOD AS RETURN
(SSW) FLOW SETS UP LATE IN THE WEEKEND INTO EARLY NEXT WEEK. PCPN
WILL BECOMES A BIT MORE DIURNALLY DRIVEN IN NATURE DURING THIS
PERIOD, WITH THE WEAK LLVL HEIGHT FALLS ALLOWING A LEE TROUGH TO
DEVELOP TO THE WEST...WHICH SHOULD BE THE FOCUS FOR SOME SCT
SHRAS EACH AFTN SUN/MON (BEST FORCING REMAINS TO OUR NNW BOTH
DAYS).
BEST RAIN CHANCES FOR THE PERIOD COME ON TUESDAY AS SFC BOUNDARY
APPROACHES FROM THE WEST AND UPPER LEVEL PATTERN RETURNING TO A
FAMILIAR SETUP AS TROUGH DIGS SOUTH FROM THE GREAT LAKES REGION
TOWARDS THE LOCAL AREA. HIGH TEMPERATURES IN UPPER 80S TO LOW 90S
SUNDAY...INCREASING INTO THE MID 90S MONDAY AND TUESDAY. EARLY
MORNING LOWS GENERALLY 70-75F.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SCT SHWRS HAVE DVLPD ACROSS SERN VA IN ASSCTD WITH A WEAK S/W
ALONG THE ACTUAL COLD FRONT. GIVEN LTST RADAR TRENDS...WENT AHEAD
WITH A VCSH FOR PHF AND TEMPO SHWRS FOR THE 06-08Z TIME FRAME.
HIGH RES MODELS HAVE THESE SHWRS DSTPG BEFORE THEY GET TO ECG SO
KEPT PCPN OUT OF THE ECG TAF ATTM. OTW...WND SHIFT TO THE NORTH
BEHIND FROPA NEXT FEW HRS WITH THE BKN SC DECK SCATTERING OUT.
VFR CNDTNS XPCTD AFTR SR...HOWEVER DATA SUPPORTS A BKN TO OCNL OVC
SC DECK BTWN 4-5K FT ALONG AND EAST OF THE CHES BAY DURING THE
DAYLIGHT HRS. CAN`T EVEN RULE OUT A SCT SHWR THIS AFTRN...BUT
CONFIDENCE NOT HIGH ENUF TO PUT ANY PCPN INTO THE CSTL TAFS ATTM.
CLRG SKIES WITH DMNSHG WNDS XPCTD AFTR 00Z.
OUTLOOK...DRY WEATHER XPCTD FIDAY. HIGH PRESSURE MOVES OFFSHORE
SATURDAY THROUGH TUESDAY RESULTING IN INCREASING HUMIDITY AND A
LOW CHC OF DIURNAL CONVECTION EACH DAY. HIGHEST CHANCE MONDAY.
&&
.MARINE...
NRLY SURGE BEHIND COLD FRONT CAME IN RTHR QUICK WITH WINDS BEHIND
LINE OF SHWRS / CD FRNT GUSTING BTWN 20-25 KTS OVR THE SRN CHES BAY.
SURGE PROGGED TO CONT FOR NEXT SVRL HRS WITH GUSTS TO 20 KTS SO WILL
KEEP SCA FOR CHES BAY GOING THRU 14Z. SCA`S ACROSS THE CSTL WTRS
LOOKING MARGINAL AND MAINLY FOR SEAS BLDG TO 5 FT OUT NR 20 NM.
WINDS / SEAS ALL SUBSIDE BLO SCA LEVELS THIS EVENING AS THE GRDNT
RELAXES. NE FLOW BECOMES E FRI THEN S FRI NIGHT THRU SAT AS HIGH PRS
MOVES OFF NEW ENDLAND COAST. WINDS/SEAS REMAIN BLO SCA LEVELS. SWLY
FLOW XPCTD SUN AND MON WITH CHCS FOR DIURNAL CONVECTION EACH DAY.
MODERATE RIP CURRENT RISK TODAY DUE TO ONSHORE FLOW WITH SURF ZONE
WAVES BTWN 3-4 FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
ANZ630>632.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ650-
652-654-656-658.
&&
$$
SYNOPSIS...SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...MAM
AVIATION...MPR
MARINE...MPR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
815 PM EDT FRI JUL 17 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EDT FRI JUL 17 2015
A FEW SHOWERS AND STORMS WILL BE POSSIBLE LATE THIS AFTERNOON SOUTH
AND EAST OF INTERSTATE 69. THESE WILL MOVE OUT QUICKLY BY EARLY
EVENING.
HEAT AND HUMIDITY WILL BUILD IN ACROSS THE AREA THROUGH THE DAY ON
SATURDAY. TEMPERATURES ARE EXPECTED TO WARM INTO THE LOWER 90S SOUTH
WHILE HEAT INDICES WILL BE AROUND 100 DEGREES. THERE IS A SLIGHT
CHANCE OF A SHOWER OR STORM SATURDAY. A BETTER CHANCE OF STORMS WILL
COME IN LATER SATURDAY NIGHT AND SUNDAY AS A COLD FRONT PUSHES
THROUGH THE AREA. COOLER AND SOMEWHAT DRIER AIR WILL FILTER IN FOR
THE BEGINNING OF THE WORK WEEK NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI JUL 17 2015
OUR BIGGEST CONCERNS IN THE FCST THROUGH SUN NIGHT ARE THE STORM
CHCS THROUGH THE PERIOD...ALONG WITH THE HEAT POTENTIAL FOR SAT. A
HEAT ADVISORY WILL BE ISSUED WITH THIS FCST PACKAGE FOR THE SRN HALF
OF THE CWFA.
WE HAVE A FEW SHOWERS/STORMS THAT WILL REMAIN POSSIBLE LATE THIS
AFTERNOON MAINLY SOUTH AND EAST OF INTERSTATE 69. WE ARE WATCHING AN
ENHANCED CU FIELD THAT STRETCHES ROUGHLY FROM MIDLAND COUNTY TO EAST
OF SOUTH HAVEN. THIS IS AHEAD OF A WEAK TROUGH DROPPING SOUTHEAST
THROUGH THE AREA ALONG WITH SOME ENHANCEMENT OCCURRING DUE TO THE
WRLY FLOW OFF OF COOLER LAKE MICHIGAN. SOUTH OF THIS LINE...MU CAPES
ARE AROUND 3000 J/KG. DEEP LAYER SHEAR STILL LOOKS TO BE LACKING A
BIT...BUT WE COULD SEE SOME STRONGER PULSE TYPE STORMS POSSIBLE
BEFORE THEY MOVE OUT EARLY THIS EVENING.
THE NEXT LOW CHC OF SOME SHOWERS AND MAYBE A STORM WOULD COME ON SAT
MORNING...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA. A COMPLEX OF
STORMS IS FCST TO DEVELOP/EXPAND ACROSS MN THIS EVENING AHEAD OF A
DEVELOPING LLJ/MOISTURE TRANSPORT THERE. THERE ARE SOME MODELS LIKE
THE HRRR AND NSSL WRF THAT BRING THIS E/SE AFTER DAYBREAK SAT
MORNING. THIS SEEMS PLAUSIBLE WITH DEEP LAYER THICKNESSES EXPECTED
TO BE ORIENTED THIS WAY AND A DEEP LAYER INSTABILITY GRADIENT VERY
SIMILAR. THE LLJ WEAKENS BY THE TIME IT GETS HERE...SO WE EXPECT IT
WOULD BE IN THE DECAYING STAGES IF IT MAKES IT HERE.
ONCE THE DECAYING LINE OF SHOWERS/STORMS IS OUT OF THE PICTURE...THE
HEAT WILL BE THE STORY. ASSUMING THERE IS NOT A PROBLEM WITH
CLEARING CLOUDS OUT SAT MORNING AND SOME POSSIBLE FOG...WE SHOULD
WARM UP QUICKLY AND DEW POINTS WILL REMAIN GENERALLY IN THE LOWER
70S. WE ARE LOOKING AT HEAT INDICES AROUND 100F ROUGHLY OVER THE SRN
HALF OF THE CWFA AWAY FROM THE IMMEDIATE LAKESHORE. WE CAN NOT RULE
OUT A POP UP STORM SAT AFTERNOON WITH A POSSIBLE OUTFLOW BOUNDARY
FLOATING AROUND AND POSSIBLE MU CAPES OF 5000 J/KG. WE LOOK VERY
CAPPED...SO THE CHCS OF A STORM ARE LIMITED TO ABOUT 10-20 PCT.
ANYTHING THAT POPS WOULD HAVE THE POTENTIAL TO BECOME SEVERE WITH
THE EXTREME INSTABILITY AVAILABLE...EVEN WITH WEAK SHEAR VALUES
AROUND 20 KNOTS.
THE BETTER CHC FOR STORMS WILL ROLL IN SAT NIGHT AND THEN MOVE OUT
LATER ON SUN. THE BEST MOISTURE TRANSPORT AND LLJ AHEAD OF THE FRONT
WILL DRIFT IN FROM THE NW SAT NIGHT. THIS WILL BRING SOME HIGHER
CHCS ACROSS THE NW PORTION OF THE AREA. THIS WILL BE ON THE EDGE OF
THE CAP AND WILL FOLLOW THE EDGE OF STRONG INSTABILITY. LARGE HAIL
WILL BE POSSIBLE...AND IT WILL HAVE THE POTENTIAL TO HAVE SOME
DAMAGING WINDS AND BE BETTER ORGANIZED AS A BETTER WIND FIELD ALOFT
MOVES IN. ADDITIONAL STORMS FIRING ALONG THE FRONT WILL HAVE THAT
POTENTIAL THEN ON SUN IF THE FRONT IS STILL IN THE AREA. IF THE
FRONT CLEARS THE CWFA SOONER RATHER THAN LATER ON SUN...THE SEVERE
THREAT WILL BE LOWER.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI JUL 17 2015
IN GENERAL NEXT WEEK LOOKS VERY SUMMER LIKE WITH HIGHS MAINLY IN THE
LOWER TO MID 80S AND LOWS IN THE MID 50S TO MID 60S. CHANCES FOR
SHOWERS AND THUNDERSTORMS LOOK RELATIVELY LOW.
CONFIDENCE IS HIGH THAT MONDAY WILL BE SUNNY AND LESS HUMID. A WEAK
COLD FRONT IS SHOWN TO DROP SOUTH THROUGH THE STATE ON TUESDAY
ALTHOUGH SOME TIMING DIFFERENCE EXISTS WITH THE ECMWF MUCH QUICKER
THAN THE GFS. EITHER WAY THE COVERAGE OF CONVECTION IS EXPECTED TO
BE LIMITED IN SW LWR MI WITH BETTER POPS IN ERN LWR MI WHERE BETTER
CONVERGENCE IS PROGGED.
HIGH PRESSURE IS EXPECTED TO DOMINATE ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AS WELL. THE ECMWF IS A BIT MORE BULLISH THAN THE GFS WITH
THE RETURN OF WAA RELATED PRECIP...AIDED BY A SHORTWAVE ALOFT...
ALREADY SHOWING QPF ON THURSDAY. THE GFS MEANWHILE WANTS TO HOLD THE
SFC RIDGE AND DRY AIR THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 815 PM EDT FRI JUL 17 2015
VFR CONDITIONS EARLY THIS EVENING...THEN SOME FOG IS EXPECTED WITH
MVFR CONDITIONS BY 06Z AND AREAS OF IFR BY 12Z. THE FOG SHOULD
LIFT BY 14Z WITH VSBYS IN THE 5 TO 6 NM RANGE THROUGH THE
AFTERNOON.
ISOLATED THUNDERSTORMS ARE POSSIBLE SATURDAY AFTERNOON...BUT WERE
NOT INCLUDED IN THE FORECAST AS COVERAGE IS EXPECTED TO BE LOW.
WINDS WILL BE SOUTHWEST AROUND AOB 10 KNOTS.
&&
.MARINE...
ISSUED AT 330 PM EDT FRI JUL 17 2015
WE HAVE EXPANDED THE MARINE DENSE FOG ADVISORY THROUGH SAT NIGHT FOR
THE TIME BEING. VISIBLE SATELLITE IMAGERY THIS AFTERNOON COMBINED
WITH WEB CAMS ALONG THE SHORE SHOW FAIRLY DENSE FOG AT MOST
LOCATIONS. CONDITIONS ARE NOT QUITE AS BAD AT SOUTH HAVEN...BUT IT
HAS EXPANDED SOUTH THIS AFTERNOON AS WINDS HAVE GONE WRLY. EVEN
HIGHER DEW POINTS MOVING IN WITH DIMINISHING WINDS WILL KEEP THE
POTENTIAL HIGH THROUGH AT LEAST SAT NIGHT.
WINDS DO NOT LOOK TO BE A PROBLEM UNTIL AT LEAST SATURDAY NIGHT IF
NOT SUNDAY. A CORE OF WINDS ALOFT AHEAD OF THE INCOMING COLD FRONT
COULD RAMP WINDS UP SAT NIGHT...HOWEVER THIS IS ALWAYS TRICKY WITH
WARMER AIR OVER THE COOLER WATERS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TO 9 PM EDT SATURDAY FOR MIZ056>059-
064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...OSTUNO
HYDROLOGY...CAS
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
659 PM CDT FRI JUL 17 2015
.UPDATE...
ISSUED AT 659 PM CDT FRI JUL 17 2015
HAVE DELAYED THE ONSET OF SHOWERS AND STORMS CLOSER TO MIDNIGHT
OVER THE WESTERN THIRD OF THE FORECAST AREA PER THE LATEST HRRR.
AS SUCH...DELAYED OVER THE REST OF THE REGION TO AFTER MIDNIGHT.
OTHER MINOR ADJUSTMENTS HAVE BEEN MADE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
FORECAST FOCUS IN THE SHORT TERM WILL BE ON STORM
CHANCES...STRENGTH...AND POTENTIAL FOR HEAVY RAIN.
A FRONTAL BOUNDARY STRETCHED FROM SOUTHERN MANITOBA THROUGH THE
RED RIVER VALLEY INTO SOUTH DAKOTA AS OF LATE AFTERNOON AND WILL
MOVE EAST OVERNIGHT MOVING INTO CENTRAL MINNESOTA BY 12Z
SATURDAY...THEN JUST CLEARING OUR EASTERN CWA BY 00Z SUN. WATER
VAPOR IMAGERY SHOWED AN UPPER LOW OVER SOUTHERN SK...AND THIS IS
FORECAST TO TRACK ALONG AND JUST NORTH OF THE INTERNATIONAL
BORDER...LAGGING THE FRONT.
SHOWERS/STORMS WILL CONTINUE TO DEVELOP ALONG THE FRONT THIS
AFTERNOON INTO TONIGHT MOVING INTO THE NORTHLAND. THE MODELS WERE
OFFERING VARIOUS SOLUTIONS AS TO HOW FAR EAST THE RAIN WILL MAKE
IT TONIGHT...AND WE BLENDED THE HRRR WITH THE GFS/NAM/ECMWF.
MLCAPE VALUES HAVE BEEN CLIMBING THIS AFTERNOON AND WERE FROM
500 OVER THE ARROWHEAD TO 1500 J/KG ACROSS OUR SOUTHERN ZONES AS
OF THE 19Z SPC MESOANALYSIS. THE HIGHEST CAPE AND NOSE OF THE LLJ
WILL REMAIN SOUTH OF OUR CWA TONIGHT AND THE HRRR SEEMS TO HAVE A
GOOD HANDLE ON DEVELOPING STRONG TO SEVERE STORMS NEAR OR JUST
SOUTH OF OUR CWA THIS EVENING. A STRONG TO SEVERE STORM WILL
REMAIN POSSIBLE OVERNIGHT OVER OUR AREA...BUT CHANCES WILL BE
HIGHEST SOUTH. WE HAVE BEEN QUITE CONCERNED ABOUT ANOTHER ROUND OF
HEAVY RAIN TONIGHT IN AREAS THAT RECEIVED HEAVY RAIN FRIDAY/FRIDAY
EVENING...MAINLY FROM NORTHERN CASS COUNTY NNE TO NORTHERN SAINT
LOUIS COUNTY. PWAT VALUES RISE TO 1.5 TO 1.7 INCHES AGAIN
TONIGHT. WE THOUGHT ABOUT ISSUING A FLASH FLOOD WATCH...BUT IT
DOES NOT APPEAR THAT TRAINING THUNDERSTORMS WILL BE AS BIG A
THREAT AS LAST NIGHT. THE HRRR/NMM/ARW HIGH RES SOLUTIONS SUPPORT
A MORE PROGRESSIVE NATURE TO THE STORMS WITH THE STRONGEST STORMS
SOUTH. WE WILL HAVE TO MONITOR CLOSELY AS 2 TO 4 INCHES OF RAIN
FELL FROM NORTHERN CASS TO KOOCHICHING COUNTIES YESTERDAY INTO THE
EVENING. THE EVENING SHIFT WILL HAVE TO MONITOR STORM
MODE/STRENGTH AND MAY HAVE TO ISSUE HEADLINES IF NEEDED.
SHOWERS/STORMS SHOULD BE ONGOING IN SPOTS SATURDAY MORNING...THEN
MAY WEAKEN OR MOVE OFF LATE MORNING. ADDITIONAL STORMS WILL
DEVELOP ALONG THE FRONT SATURDAY AFTERNOON AND THEY COULD BE
SEVERE...MAINLY OVER PORTIONS OF NORTHWEST WISCONSIN WHERE A MOIST
UNSTABLE AIRMASS WILL BE IN PLACE. DEWPOINTS AHEAD OF THE FRONT
WILL BE FROM 65 TO AROUND 70...THEN DROP BEHIND IT. MOST AREAS
SHOULD RISE INTO THE UPPER 70S TO MID 80S ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
SATURDAY NIGHT...A COLD FRONT WILL FINISH MOVING THROUGH THE
NORTHLAND IN THE LATE EVENING...WHILE AN UPPER LEVEL TROUGH OVER
MANITOBA/ONTARIO LIFTS THROUGH THE REGION. THERE COULD BE LINGERING
SHOWERS AND STORMS IN NW WISCONSIN AND FAR NORTHERN MINNESOTA BEFORE
MIDNIGHT.
SUNDAY...WARMER AIR WILL BEGIN TO FILTER BACK INTO THE NORTHLAND
WITH THE WESTERLY FLOW. THE NAM12 SOUNDINGS INDICATE BREEZY
CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. MOST OF THE
MODELS ARE DRY...BUT THE SREF IS INDICATING LOW PCPN CHANCES...SO
ADDED THE SREF TO THE MODEL BLEND TO GIVE LOW CHANCES OF SHOWERS AND
STORMS OVER NORTHERN MINNESOTA.
MONDAY...THE MODELS ARE NOT IN GOOD AGREEMENT...BUT GENERALLY
INDICATE ANOTHER COLD FRONT WILL MOVE FROM NW TO SE THROUGH THE
FORECAST AREA. THE ECMWF IS ABOUT 12 TO 18 HOURS FASTER THAN THE GFS
AND GEM. THE TIMING OF THE FRONT HAS IMPLICATIONS ON TEMPERATURES
AND PCPN CHANCES. SINCE THE ECMWF FRONT PASSAGE IS DURING THE WEE
HOURS OF MONDAY MORNING...IT DOES NOT HAVE THE INSTABILITY AND PCPN
THAT THE GFS AND GEM ARE INDICATING WITH THE AFTERNOON/EVENING
PASSAGE TIMEFRAME. THE GFS HAS MUCH HOTTER TEMPERATURES FOR
MONDAY...PARTLY SINCE ITS COLD FRONT PASSAGE IS NOT UNTIL MONDAY
NIGHT. USED A BLEND OF THE GFS/GEM/ECMWF/SREF.
TUESDAY...HIGH PRESSURE WILL LIKELY KEEP THE NORTHLAND DRY AND A BIT
COOLER FOR THIS DAY. TEMPERATURES WILL LIKELY BE SEASONAL NORMALS
WITH HIGHS IN THE UPPER 70S.
WEDNESDAY AND THURSDAY...THE MODELS ARE IN POOR AGREEMENT...BUT
GENERALLY SUGGEST A WARM AND HUMID SOUTHERLY LOW LEVEL FLOW PATTERN
SETTING UP DURING THIS TIME. THIS COULD BEGIN TO BRING WARMER AND
UNSTABLE AIR INTO THE REGION. SHOWERS AND THUNDERSTORMS ARE
POSSIBLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 631 PM CDT FRI JUL 17 2015
VFR AT THE OUTSET OF THE FORECAST. CIRRUS CLOUDS WILL OVERSPREAD
THE TERMINALS TONIGHT. SHOWERS AND THUNDERSTORMS WILL APPROACH BRD
AND INL AROUND 07Z AND THEN MOVE THROUGH THE REST OF THE TERMINALS
BY 17Z. SOME MVFR VSBYS MAY ACCOMPANY THE STRONGER STORMS. AFTER
18Z...THE STORMS DEPART WITH VFR AND GUSTY SFC WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 66 82 60 81 / 40 50 10 10
INL 61 79 57 78 / 70 50 10 20
BRD 66 83 59 84 / 60 20 0 10
HYR 65 85 60 81 / 40 50 0 10
ASX 63 85 61 81 / 30 50 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
631 PM CDT FRI JUL 17 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
FORECAST FOCUS IN THE SHORT TERM WILL BE ON STORM
CHANCES...STRENGTH...AND POTENTIAL FOR HEAVY RAIN.
AS OF 3 PM SHOWERS AND STORMS WERE MOVING NORTHEAST THROUGH
NORTHWEST MINNESOTA TOWARD KOOCHICHING COUNTY. THE STORMS HAVE
WEAKENED AS THEY HAVE MOVED OUT OF NORTHWEST MINNESOTA AND MOST
OF THE CAMS HAVE SHOWN THIS TREND...ALTHOUGH THE PRECIP IS FURTHER
EAST THAN MOST HAD IT AT THIS TIME. A FRONTAL BOUNDARY STRETCHED
FROM SOUTHERN MANITOBA THROUGH THE RED RIVER VALLEY INTO SOUTH
DAKOTA AS OF LATE AFTERNOON AND WILL MOVE EAST OVERNIGHT MOVING
INTO CENTRAL MINNESOTA BY 12Z SATURDAY...THEN JUST CLEARING OUR
EASTERN CWA BY 00Z SUN. WATER VAPOR IMAGERY SHOWED AN UPPER LOW
OVER SOUTHERN SK...AND THIS IS FORECAST TO TRACK ALONG AND JUST
NORTH OF THE INTERNATIONAL BORDER...LAGGING THE FRONT.
SHOWERS/STORMS WILL CONTINUE TO DEVELOP ALONG THE FRONT THIS
AFTERNOON INTO TONIGHT MOVING INTO THE NORTHLAND. THE MODELS WERE
OFFERING VARIOUS SOLUTIONS AS TO HOW FAR EAST THE RAIN WILL MAKE
IT TONIGHT...AND WE BLENDED THE HRRR WITH THE GFS/NAM/ECMWF.
MLCAPE VALUES HAVE BEEN CLIMBING THIS AFTERNOON AND WERE FROM
500 OVER THE ARROWHEAD TO 1500 J/KG ACROSS OUR SOUTHERN ZONES AS
OF THE 19Z SPC MESOANALYSIS. THE HIGHEST CAPE AND NOSE OF THE LLJ
WILL REMAIN SOUTH OF OUR CWA TONIGHT AND THE HRRR SEEMS TO HAVE A
GOOD HANDLE ON DEVELOPING STRONG TO SEVERE STORMS NEAR OR JUST
SOUTH OF OUR CWA THIS EVENING. A STRONG TO SEVERE STORM WILL
REMAIN POSSIBLE OVERNIGHT OVER OUR AREA...BUT CHANCES WILL BE
HIGHEST SOUTH. WE HAVE BEEN QUITE CONCERNED ABOUT ANOTHER ROUND OF
HEAVY RAIN TONIGHT IN AREAS THAT RECEIVED HEAVY RAIN FRIDAY/FRIDAY
EVENING...MAINLY FROM NORTHERN CASS COUNTY NNE TO NORTHERN SAINT
LOUIS COUNTY. PWAT VALUES RISE TO 1.5 TO 1.7 INCHES AGAIN
TONIGHT. WE THOUGHT ABOUT ISSUING A FLASH FLOOD WATCH...BUT IT
DOES NOT APPEAR THAT TRAINING THUNDERSTORMS WILL BE AS BIG A
THREAT AS LAST NIGHT. THE HRRR/NMM/ARW HIGH RES SOLUTIONS SUPPORT
A MORE PROGRESSIVE NATURE TO THE STORMS WITH THE STRONGEST STORMS
SOUTH. WE WILL HAVE TO MONITOR CLOSELY AS 2 TO 4 INCHES OF RAIN
FELL FROM NORTHERN CASS TO KOOCHICHING COUNTIES YESTERDAY INTO THE
EVENING. THE EVENING SHIFT WILL HAVE TO MONITOR STORM
MODE/STRENGTH AND MAY HAVE TO ISSUE HEADLINES IF NEEDED.
SHOWERS/STORMS SHOULD BE ONGOING IN SPOTS SATURDAY MORNING...THEN
MAY WEAKEN OR MOVE OFF LATE MORNING. ADDITIONAL STORMS WILL
DEVELOP ALONG THE FRONT SATURDAY AFTERNOON AND THEY COULD BE
SEVERE...MAINLY OVER PORTIONS OF NORTHWEST WISCONSIN WHERE A MOIST
UNSTABLE AIRMASS WILL BE IN PLACE. DEWPOINTS AHEAD OF THE FRONT
WILL BE FROM 65 TO AROUND 70...THEN DROP BEHIND IT. MOST AREAS
SHOULD RISE INTO THE UPPER 70S TO MID 80S ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
SATURDAY NIGHT...A COLD FRONT WILL FINISH MOVING THROUGH THE
NORTHLAND IN THE LATE EVENING...WHILE AN UPPER LEVEL TROUGH OVER
MANITOBA/ONTARIO LIFTS THROUGH THE REGION. THERE COULD BE LINGERING
SHOWERS AND STORMS IN NW WISCONSIN AND FAR NORTHERN MINNESOTA BEFORE
MIDNIGHT.
SUNDAY...WARMER AIR WILL BEGIN TO FILTER BACK INTO THE NORTHLAND
WITH THE WESTERLY FLOW. THE NAM12 SOUNDINGS INDICATE BREEZY
CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. MOST OF THE
MODELS ARE DRY...BUT THE SREF IS INDICATING LOW PCPN CHANCES...SO
ADDED THE SREF TO THE MODEL BLEND TO GIVE LOW CHANCES OF SHOWERS AND
STORMS OVER NORTHERN MINNESOTA.
MONDAY...THE MODELS ARE NOT IN GOOD AGREEMENT...BUT GENERALLY
INDICATE ANOTHER COLD FRONT WILL MOVE FROM NW TO SE THROUGH THE
FORECAST AREA. THE ECMWF IS ABOUT 12 TO 18 HOURS FASTER THAN THE GFS
AND GEM. THE TIMING OF THE FRONT HAS IMPLICATIONS ON TEMPERATURES
AND PCPN CHANCES. SINCE THE ECMWF FRONT PASSAGE IS DURING THE WEE
HOURS OF MONDAY MORNING...IT DOES NOT HAVE THE INSTABILITY AND PCPN
THAT THE GFS AND GEM ARE INDICATING WITH THE AFTERNOON/EVENING
PASSAGE TIMEFRAME. THE GFS HAS MUCH HOTTER TEMPERATURES FOR
MONDAY...PARTLY SINCE ITS COLD FRONT PASSAGE IS NOT UNTIL MONDAY
NIGHT. USED A BLEND OF THE GFS/GEM/ECMWF/SREF.
TUESDAY...HIGH PRESSURE WILL LIKELY KEEP THE NORTHLAND DRY AND A BIT
COOLER FOR THIS DAY. TEMPERATURES WILL LIKELY BE SEASONAL NORMALS
WITH HIGHS IN THE UPPER 70S.
WEDNESDAY AND THURSDAY...THE MODELS ARE IN POOR AGREEMENT...BUT
GENERALLY SUGGEST A WARM AND HUMID SOUTHERLY LOW LEVEL FLOW PATTERN
SETTING UP DURING THIS TIME. THIS COULD BEGIN TO BRING WARMER AND
UNSTABLE AIR INTO THE REGION. SHOWERS AND THUNDERSTORMS ARE
POSSIBLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 631 PM CDT FRI JUL 17 2015
VFR AT THE OUTSET OF THE FORECAST. CIRRUS CLOUDS WILL OVERSPREAD
THE TERMINALS TONIGHT. SHOWERS AND THUNDERSTORMS WILL APPROACH BRD
AND INL AROUND 07Z AND THEN MOVE THROUGH THE REST OF THE TERMINALS
BY 17Z. SOME MVFR VSBYS MAY ACCOMPANY THE STRONGER STORMS. AFTER
18Z...THE STORMS DEPART WITH VFR AND GUSTY SFC WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 65 82 60 81 / 40 50 10 10
INL 61 79 57 78 / 70 50 10 20
BRD 66 83 59 84 / 60 20 0 10
HYR 65 85 60 81 / 40 50 0 10
ASX 63 85 61 81 / 30 50 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION...UPDATE
NWS JACKSON MS
958 AM CDT THU JUL 16 2015
.UPDATE...SUBTLE EVIDENCE THIS MORNING THAT CONVECTION FROM LATE
YESTERDAY LEFT A LOW LEVEL MOISTURE CONVERGENCE BOUNDARY DRAPED
ACROSS THE REGION FROM AROUND GWO SE TO AROUND MEI. RAP ANALYSIS
SHOWS RATHER POTENT THETAE RIDGE AT 850MB OVERTOP OF THIS BOUNDARY
WITH EVEN THE 12Z JAN SOUNDING (WEST OF THIS AXIS) DEPICTING MUCH
LESS CAPPING AND BETTER LAPSE RATES THAN WAS THE CASE YESTERDAY
MORNING. THE UPPER RIDGE CENTER SEEMS TO BE LOCATED JUST A LITTLE
WEST OF THE MS RIVER BUT WV IMAGERY SHOW SOME WEAK DISTURBANCES
COULD SLIDE DOWN THE EAST SIDE OF THIS RIDGE TO INTERACT WITH THE
AFOREMENTIONED BOUNDARY LATER ON THIS AFTERNOON. PREVIOUS SHIFT HAD
20 TO 30 POPS CO-LOCATED WITH THIS BOUNDARY THIS AFTERNOON BUT GIVEN
ABOVE EVIDENCE AND LATEST HRRR PICKING UP BETTER ON ACTIVITY I WILL
BUMP UP POPS SOME 5 TO 15 POINTS IN EASTERN ZONES. IN
ADDITION...PEAK SBCAPE NUMBERS ARE EXPECTED TO BE NEAR 5000 J/KG
AROUND THIS CONVERGENT AXIS LATER THIS AFTERNOON WITH OTHER
PARAMETERS ALSO SOMEWHAT CONDUCIVE FOR MICROBURST DEVELOPMENT. WITH
THIS IN MIND INCLUDED A LIMITED RISK FOR SEVERE STORMS FOR
NORTHEASTERN ZONES OF THE CWA.
AS FOR TEMPS AND HEAT...NO CHANGES WERE MADE TO THE PREVIOUS
FORECASTER`S EXPECTATIONS IN THAT REGARD. OF COURSE LATE-DAY
THUNDERSTORMS COULD PROVIDE A LITTLE RELIEF IN NORTHEASTERN ZONES
(MUCH LIKE YESTERDAY)...BUT WILL LIKELY COME TOO LATE TO SPARE FROM
THE WORST OF THE AFTERNOON HEAT. STILL ANTICIPATING PARTS OF THE
ARKLAMISS DELTA TO SEE APPARENT TEMPS PEAK A LITTLE ABOVE 110 THIS
AFTERNOON SO HEAT WARNING THERE SEEMS WARRANTED. WILL LIKELY AT
LEAST MAKE SOME FINE-SCALE ADJUSTMENTS TO HEAT PRODUCTS FOR THE
AFTERNOON PACKAGE AFTER SEEING THE WAY THINGS PLAY OUT THROUGH THE
BULK OF THE DAYLIGHT HOURS./BB/
&&
.AVIATION...SCT SHRA/TSRA ARE EXPECTED ACROSS EAST MS THIS
AFTERNOON, WHICH MAY BRING BRIEF CATEGORICAL REDUCTIONS ALONG WITH
GUSTY WINDS AT GTR, MEI, AND HBG. OTHERWISE, VFR CONDITIONS WILL
PREVAIL THROUGH THE TAF PERIOD. /DL/
&&
.PREV DISCUSSION... /ISSUED 413 AM CDT THU JUL 16 2015/
DISCUSSION...
SHORT TERM (TODAY THROUGH FRIDAY NIGHT)...THE HEAT WAVE CONTINUES
THROUGH THE SHORT TERM AS THE MID/UPPER RIDGE BEGINS TO BUILD
FARTHER EASTWARD, BECOMING CENTERED NEAR AND JUST WEST OF THE
FORECAST AREA. THOUGH CONVERGENCE IS WEAKENING ALONG THE SURFACE
TROUGH WHICH WAS A FOCUS FOR CONVECTIVE DEVELOPMENT WED AFTERNOON/
EVENING, THIS FEATURE REMAINS POSITIONED THIS MORNING FROM NORTH MS
INTO AL. IT WILL BE COLLOCATED WITH GREATER MID LEVEL (AND FOR THAT
MATTER, DEEP LAYER) MOISTURE TODAY, AND SHOULD AID IN THE DEVELOPMENT
OF ISOLATED TO SCATTERED CONVECTION EAST OF I-55 THIS AFTERNOON.
GIVEN THE CONSIDERABLE INSTABILITY THAT WILL EXIST, A FEW OF THESE
STORMS COULD BE ON THE STRONG SIDE, BUT THE THREAT IS TOO CONDITIONAL
TO INCLUDE IN HAZARD PRODUCTS AT THIS POINT. DIURNAL CONVECTION
SHOULD BE MORE LIMITED TO THE SOUTHEASTERN QUADRANT OF THE AREA ON
FRIDAY AS THE RIDGE CONTINUES TO BUILD IN.
TEMPERATURE-WISE, MOS MAX TEMP OFFERINGS CONTINUE TO APPEAR
UNREALISTICALLY HIGH BY A DEGREE OR TWO AS DEWPOINTS HAVE BEEN
STAYING WELL UP INTO THE 70S IN MOST AREAS (SAVE FOR THE SOUTHEAST).
ON THE OTHER HAND, IN HOUSE MODEL BLENDS APPEARED TOO LOW FOR TODAY.
THUS OPTED TO TAKE A PERSISTENCE APPROACH FOR TODAY`S HIGHS...MAKING
JUST A FEW TWEAKS FROM YESTERDAY`S OBSERVED MAX. THIS ALONG WITH
FORECAST DEWPOINTS (ALSO BASED SOMEWHAT ON PERSISTENCE) YIELDED HEAT
INDICES OVER 110 ACROSS PORTIONS OF THE DELTA. READINGS OF THIS
MAGNITUDE HAVE BEEN OBSERVED OFF AND ON OVER THE PAST FEW DAYS OVER
THE NORTHERN HALF OF THE CWA, BUT MOST PERSISTENTLY IN THIS
PARTICULAR AREA. SEE LITTLE REASON WHY THAT WOULD CHANGE TODAY,
THEREFORE, AN EXCESSIVE HEAT WARNING HAS BEEN POSTED FOR A PORTION
OF THE ARKLAMISS DELTA THROUGH 00Z. BEYOND THAT TIME, WILL KEEP THE
EXISTING HEAT ADVISORY, THOUGH AN UPGRADE MAY EVENTUALLY BE NEEDED
FOR FRIDAY AS WELL. THE HEAT ADVISORY WAS ALSO EXPANDED SOUTHWARD BY
A ROW OF COUNTIES AND PARISHES EFFECTIVE THROUGH FRIDAY. /DL/
LONG TERM (SATURDAY THROUGH WEDNESDAY)...THE HEAT AND HUMIDITY WILL
REMAIN THE FOCUS THROUGH THE LONG TERM. SOME OF THE HOTTEST
TEMPERATURES THROUGH NEXT WEEK ARE EXPECTED SATURDAY THROUGH MONDAY
WHERE ENSEMBLE GUIDANCE SUGGESTS SITES WILL APPROACH THE CENTURY MARK
ACROSS OUR NORTH EACH AFTERNOON. COMBINED WITH CONTINUED HIGH
HUMIDITY HEAT INDEX VALUES WILL PEAK AROUND 110 EACH DAY SATURDAY
THROUGH MONDAY WARRANTING AT LEAST A CONTINUATION OF A HEAT ADVISORY
AND/OR AN EXCESSIVE HEAT WARNING FOR PORTIONS OF THE AREA.
COME SATURDAY MODELS ARE IN GOOD AGREEMENT THAT A LARGE 594DAM RIDGE
AXIS WILL EXTEND OVER OUR CWA FROM THE SOUTHERN PLAINS. A 1015MB
SURFACE RIDGE IS EXPECTED TO BE ALONG THE NORTHERN GULF RESULTING IN
A LOW LEVEL SOUTHWEST TO WEST FLOW ACROSS OUR CWA. THIS FLOW IS NOT
FAVORABLE FOR SEA BREEZE ACTIVITY INTO OUR CWA BUT THE BEST CHANCE
FOR ANY STORM IN OUR CWA WILL BE THE SOUTHERN ZONES THROUGH THE
WEEKEND. MODEL RUN ACCUMULATIONS THROUGH THE WEEK SHOW NO RAINFALL
OVER OUR NORTHEAST LOUISIANA PARISHES AND PORTIONS OF THE DELTA
WITH ONLY LIGHT AMOUNTS ACROSS THE NORTH AND SOUTH. MONDAY A
SHORTWAVE WILL SWING ACROSS THE NORTHERN FRINGES OF THE LARGE MID
LEVEL RIDGE AND TRY TO DROP AN ASSOCIATED COLD FRONT OUR WAY. THE
FRONT LOOKS TO STALL WELL NORTH OF OUR AREA BUT SOME CLOUD COVER AND
RAIN MAY TRACK OVER OUR NORTHEAST ZONES AS A RESULT ON TUESDAY. THE
MID LEVEL RIDGE WILL WEAKEN SOME TUESDAY AND WEDNESDAY ALLOWING FOR
A LITTLE MORE AFTERNOON AND EVENING CONVECTION IN THE SOUTH AS WELL.
/22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 96 77 96 77 / 17 13 10 5
MERIDIAN 95 75 95 75 / 35 24 16 7
VICKSBURG 95 75 95 75 / 9 5 7 4
HATTIESBURG 95 77 95 77 / 24 20 25 12
NATCHEZ 93 74 93 74 / 9 5 11 5
GREENVILLE 97 77 96 77 / 11 7 5 3
GREENWOOD 95 76 95 76 / 21 14 6 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR MSZ027>033-036>060.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR MSZ018-
019-025-026-034-035.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT FRIDAY FOR
MSZ018-019-025-026-034-035.
LA...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR LAZ007>009-015-016-
023>026.
AR...HEAT ADVISORY UNTIL 7 PM CDT FRIDAY FOR ARZ074-075.
&&
$$
BB/15/DL/22
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
931 PM CDT FRI JUL 17 2015
.UPDATE:
ISSUED AT 931 PM CDT FRI JUL 17 2015
THUNDERSTORMS HAVE MOVED EAST OUT OF THE AREA AND RAP MASS FIELDS
NOT SHOWING ANY LIKELIHOOD OF REDEVELOPMENT OVERNIGHT. HAVE KEPT
WITH THE DRY FORECAST. STILL LOOKS LIKE A WARM AND MUGGY NIGHT AS
CURRENT DEWPOINTS ARE IN THE MID-UPPER 70S IN MOST AREAS WITH
CURRENT TEMPERATURES STILL IN THE 80S.
BRITT
&&
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 239 PM CDT FRI JUL 17 2015
PESKY NARROW BAND OF CONVECTION FROM NORTHERN OZARKS TO S
SECTIONS OF STL METRO HAS BEEN FINALLY BEGUN TO WEAKEN OVER THE
PAST HOUR OR SO, WHILE CONVECTION OVER SOUTHERN IL HAS
INTENSIFIED JUST A BIT AS IT ENCOUNTERS A SLIGHTLY MORE FAVORABLE
ENVIRONMENT/SLIGHTLY COOLER MID LEVEL TEMPS. WILL MAINTAIN SOME
SLIGHT CHANCE POPS FOR VERY EARLY THIS EVENING FOR SOUTHEAST
SECTIONS OF THE CWA...DUE TO THE COMBINATION OF CURRENT ACTIVITY
AS WELL AS POTENTIAL FOR SOME OF THE WEAKENING UPSTREAM
CONVECTION OVER SW MO ADVECTING INTO THE AREA. OTHERWISE AND
ELSEWHERE...DRY WEATHER IS FORECAST WITH THE EMPHASIS REMAINING
ON THE WARM AND MUGGY JULY AIRMASS. HAVE GONE WITH LOWS IN THE
70S, BUT ITS CERTAINLY POSSIBLE THAT HEAT ISLAND OF STL METRO MAY
HAVE TROUBLE DIPPING BELOW 80.
TRUETT
.LONG TERM: (SATURDAY THROUGH NEXT FRIDAY)
ISSUED AT 239 PM CDT FRI JUL 17 2015
OPPRESSIVELY HOT AND HUMID CONDITIONS WILL LIKELY CONTINUE ACROSS
MOST OF THE AREA THROUGH SUNDAY EVENING UNTIL A COLD FRONT EDGES
INTO MO/IL ON SUNDAY NIGHT. NO CHANGES WERE MADE TO THE EXISTING
HEAT ADVISORY.
A WEAK VORT MAX ACCOMPANYING THE COLD FRONT SHOULD SUPPORT SCT
SH/TS AHEAD OF THE FRONT ON LATE SUNDAY AFTERNOON FOLLOWED BY
INCREASINGLY ELEVATED CONVECTION INVOF THE FRONT ON SUNDAY NIGHT
INTO MONDAY. MODELS SHOW THAT THE FRONT WILL BE MOVING INTO AN
ENVIRONMENT WITH AROUND 2000 J/KG OF CAPE AND 20-30 KTS OF 0-6 KM
SHEAR AS WELL AS 2" PWAT AND H7-H5 LAPSE RATES OF 6-6.5 DEG
C/KM...THEREFORE STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ON
SUNDAY AFTN/EVE.
ADDITIONAL VORT MAXES OR MCVS COULD SUPPORT ISO-SCT SH/TS EARLY
NEXT WEEK DURING A BRIEF PERIOD OF NW FLOW ALOFT UNTIL THE UPPER
RIDGE RE-ESTABLISHES ITSELF BY MID/LATE WEEK.
KANOFSKY
&&
.AVIATION: (FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 622 PM CDT FRI JUL 17 2015
VFR AND DRY THRU THE PERIOD. SLY TO SWLY WINDS ARE EXPECTED TO
PERSIST. LLWS MAY NEED TO BE ADDED FOR LATE TONIGHT FOR COU AND
UIN...BUT CURRENTLY LOOKS BELOW CRITERIA.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR CRAWFORD
MO-IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR KNOX MO-LEWIS MO-
MARION MO-MONROE MO-PIKE MO-RALLS MO-SHELBY MO.
IL...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR BOND IL-
CLINTON IL-FAYETTE IL-MARION IL-MONTGOMERY IL-RANDOLPH IL-
WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR CALHOUN IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-ST. CLAIR IL.
HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR ADAMS IL-BROWN IL-PIKE
IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1134 PM CDT WED JUL 15 2015
.UPDATE:
ISSUED AT 944 PM CDT WED JUL 15 2015
CONVECTION HAS BEGUN TO DEVELOP ACROSS PARTS OF NORTHWEST MO AND
SOUTHWEST IA IN AN AREA OF LOW LEVEL WARM AIR ADVECTION ON THE
NOSE OF A SOUTHERLY LOW LEVEL JET, AND AHEAD OF A SHORTWAVE
MOVING EASTWARD THROUGH SOUTHERN NEBRASKA. THIS ACTIVITY SHOULD
CONTINUE TO DEVELOP INTO AN MCS AND MOVE ACROSS SOUTHERN IA AND
NORTHERN MO. THE LATEST HRRR MODEL RUN KEEPS MOST OF THE
CONVECTION NORTH AND WEST OF OUR FORECAST AREA THROUGH 12Z EARLY
THIS MORNING, BUT WILL CONTINUE WITH LIKELY POPS LATE TONIGHT
ACROSS A PORTION OF NORTHEAST MO AS THE LATEST NAM MODEL RUN HAS
ITS QPF FURTHER SOUTH, AND THERE WILL BE THE POTENTIAL FOR THE
CONVECTIVE COMPLEX TO BEGIN DROPPING SOUTHEASTWARD AS IT MOVES
FURTHER EAST INTO NORTHEAST MO AND SOUTHEAST IA LATE TONIGHT. THE
ACTIVITY MAY WEAKEN SOME AS IT GETS FURTHER EAST INTO SLIGHTLY
LESS FAVORABLE MOISTURE AND INSTABILITY NEAR THE SOUTHWESTERN
PERIPHERY OF THE SURFACE RIDGE CENTERED OVER THE GREAT LAKES
REGION.
GKS
&&
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 253 PM CDT WED JUL 15 2015
UPPER RIDGE REMAINS IN PLACE OVERNIGHT. FRONTAL BNDRY THAT PASSED
THRU THE FA YESTERDAY/LAST EVNG WILL BEGIN LIFTING BACK NORTH
TONIGHT IN RESPONSE TO AN AREA OF LOW PRESSURE LIFTING NE OUT OF THE
PLAINS. SHRAS/TSTMS SHOULD BE ONGOING AT THE BEGINNING OF THE PRD
ALONG THE FRONT FROM WRN MO INTO S CNTRL MO WITH ACTIVITY SLIDING SE
ALONG THE BNDRY. DON`T EXPECT MUCH ACTIVITY IN OUR CWA BUT BORDER
WITH SGF MAY GET BRUSHED LATE THIS AFTN INTO THIS EVNG. FOCUS THEN
SHIFTS NORTH AS AN MCS ASSOC WITH THE AFOREMENTIONED SFC LOW TRACKS
FROM THE CNTRL PLAINS THIS EVNG INTO THE UPPER MIDWEST BY TOMORROW.
THERE SHOULD BE A WAA WING OF PRECIP EMANATING FROM THE STHRN SIDE
OF THE MCS AFFECTING THE NTHRN PORTION OF THE CWA OVERNIGHT. THIS
ACTIVITY SHOULD MOVE EAST OF THE FA THURSDAY MORNING.
2%
.LONG TERM: (THURSDAY THROUGH NEXT WEDNESDAY)
ISSUED AT 253 PM CDT WED JUL 15 2015
THURSDAY-FRIDAY NIGHT
THERE SHOULD BE A BIT OF A BREAK IN THE PRECIP FROM LATE THURSDAY
MRNG INTO THE AFTN BEFORE ADDTNL CONVECTION DEVELOPS ALONG THE
ADVANCING WARM FRONT. THIS ACTIVITY SHOULD LIFT NE OF THE FA
THURSDAY EVNG ALONG WITH THE BNDRY...BUT THERE COULD BE LINGERING
PRECIP ACROSS NE MO AND W CNTRL IL INTO THE OVERNIGHT HRS. NOT
EXPECTING WIDESPREAD SVR TSTMS AS THE BEST SHEAR IS FCST TO REMAIN
ALONG AND NORTH OF THE IA/MO BORDER BUT CAN/T RULE OUT AN ISLD
STRONG/SVR STORM.
UPPER FLOW FLATTENS AND BECOMES ZONAL BY THURSDAY NIGHT. PASSAGE OF
THE WARM FRONT SIGNALS THE START OF THE NEXT WARMING TREND. 850MB
TEMPS RISE INTO THE LOWER 20S BY FRIDAY WHICH CLIMATOLOGICALLY
CORRESPONDED TO SFC TEMPS IN THE LOW/MID 90S. MOS GUIDANCE WAS IN
GOOD AGREEMENT WRT TEMPS SO USED A BLEND.
SATURDAY-TUESDAY
UPPER LVL RIDGE REASSERTS ITSELF OVER THE WKND BCMNG CENTERED OVER
STHRN AR/NTHRN LA SO EXPECTED A TYPICAL MID JULY WKND WITH TEMPS IN
THE 90S AND PLENTY OF HUMIDITY. THE GFS HAS COME INTO BETTER
AGREEMENT WITH THE ECMWF WRT HOW TO HANDLE ENERGY ASSOC WITH A
CLOSED LOW TRACKING ACROSS CANADA OVER THE WKND. THE GFS IS NOW
CLOSER TO THE ECMWF/S FASTER SOLUTION WRT SHORT WAVE ENERGY. MAIN
ENERGY ASSOC WITH THE SHORT WAVE IS EXPECTED TO PASS NORTH OF THE
CWA BUT THIS FEATURE SHOULD HELP FLATTEN THE RIDGE AND SHIFT THE
CENTER OF THE UPPER LVL RIDGE WEST ACROSS TX FOR EARLY NEXT
WEEK...WHICH MEANS THE REGION IS FCST TO REMAIN UNDER ZONAL FLOW
INTO MID-WEEK. THE SHORT WAVE WILL ALSO BE RESPONSIBLE FOR
DROPPING A COLD FRONT INTO THE AREA SUNDAY EVNG...WHICH WILL ALSO
BE THE NEXT CHANCE FOR PRECIP ACROSS THE AREA. THE BNDRY SHOULD
CLEAR THE STHRN ZONES MONDAY NIGHT. HIGH PRESSURE SLIDES EAST
TUESDAY NIGHT ALLOWING RETURN FLOW TO COMMENCE.
THE HEAT IS EXPECTED TO LAST THRU THE WKND WITH HIGHS IN THE
90S...COUPLED WITH DPS IN THE 70S...MEANS THAT A HEAT HEADLINE WILL
LIKELY BE NEEDED OVER THE WKND. THE COLD FRONT IS FCST TO DROP 850MB
TEMPS INTO THE UPPER TEENS TO NEAR 20. THAT WILL HELP TEMPS TO
RETURN TO NEAR NORMAL WITH HIGHS IN THE MID 80S TO LOW 90S AND LOWS
IN THE UPPER 60S TO LOWER 70S.
2%
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1120 PM CDT WED JUL 15 2015
THUNDERSTORMS HAVE ALREADY DEVELOPED OVER NORTHERN MISSOURI LATE
THIS EVENING AND ARE EXPECTED TO TO MOVE EAST AND NORTHEAST
THROUGH THE MORNING HOURS. THEY SHOULD AFFECT KUIN, SO HAVE ADDED
VCTS AND TEMPO GROUPS FOR -SHRA AT THIS TERMINAL. CHANCES REMAIN
TOO LOW AT KCOU AND THE ST. LOUIS METRO TAF SITES TO WARRANT
INCLUDING AT THOSE TERMINALS AT THIS POINT. THESE STORMS ARE
FORMING AHEAD OF A WARM FRONT THAT WILL MOVE NORTH OF THE AREA BY
MIDDAY ON THURSDAY. THE EAST TO SOUTHEASTERLY WINDS OVER THE AREA
CURRENTLY WILL VEER SOUTHERLY BEHIND THE FRONT.
SPECIFICS FOR KSTL: EXPECT DRY AND VFR CONDITIONS THROUGH THE TAF
PERIOD. THUNDERSTORMS ARE EXPECTED TO STAY WELL NORTH OF THE
TERMINAL THIS MORNING, SO HAVE NOT ADDED THEM TO THE TERMINAL. A
WARM FRONT WILL PASS THROUGH THE TERMINAL BY LATE MORNING CAUSING
EASTERLY WINDS TO VEER TO THE SOUTH.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
846 PM MDT FRI JUL 17 2015
.UPDATE...
VERY LITTLE CHANGE TO THE GOING FORECAST. JUST ADJUSTED SKY
COVER...DEWPOINTS AND WINDS TO GET CLOSER TO LATEST OBSERVED AND
MODEL TRENDS. AT 02Z...COLD FRONT WAS FROM NEAR KMLS TO LITTLE
BIGHORN TO BURNT MOUNTAIN. MAIN EFFECTS FROM FRONTAL PASSAGE WERE
GUSTY NW WINDS AND FALLING TEMPERATURES AND DEWPOINTS. WIND GUSTS
WILL DIMINISH AFTER 06Z WHEN AREA OF PRESSURE RISES MOVES S OF THE
FORECAST AREA PER LATEST RUC AND WRF. INSTABILITY WAS LOW...WITH
POCKETS OF 500 J/KG OF CAPE OVER SE MT AND SHERIDAN COUNTY WY.
MESOANALYSIS ALSO INDICATED A FEW AREAS OF 40-50 KT OF SHEAR OVER
THESE AREAS. A FEW SHOWERS AND THUNDERSTORMS WERE MOVING E THROUGH
THE SOUTHERN PORTION OF THE NE BIGHORNS AT 0230Z...AND OCCASIONAL
WEAK ECHOES HAVE BEEN MOVING THROUGH SE MT THIS EVENING. THE
PRECIPITATION WAS BEING CAUSED BY SHORTWAVE ENERGY MOVING IN FROM
A TROUGH OVER THE PACIFIC NW AND AROUND THE UPPER LOW OVER
SASKATCHEWAN...AS WELL AS SOME FRONTOGENESIS. ADDITIONAL ENERGY
WAS MOVING INTO THE NW ZONES. THE FRONTOGENESIS AND SHORTWAVE
ENERGY WILL WEAKEN OVERNIGHT. POP FORECAST FOCUS SHIFTS FROM SE
MT...SHERIDAN COUNTY AND THE SW MOUNTAINS...TO THE NW ZONES
OVERNIGHT WHICH LOOKED REASONABLE GIVEN THE ABOVE.
MORE SHORTWAVE ENERGY WILL MOVE INTO THE AREA FROM THE PACIFIC NW
TROUGH ON SAT SUPPORTING CHANCES FOR PRECIPITATION. ARTHUR
&&
.SHORT TERM...VALID FOR SAT AND SUN...
UPPER LOW NOW OVER SASKATCHEWAN IS MOVING VERY SLOWLY...WITH
TROWAL BRINGING INCREASED CLOUD COVER AND SOME PCPN OVER NORTHWEST
MT. SECOND REMARKABLY COOL AFTERNOON IN A ROW FOR CUT BANK WITH 52
DEGREES AND RAIN AT 1 PM. IN OUR CWA...THERE REMAINS A NARROW BAND
OF BROKEN SHOWERS FROM THE BIGHORN MTNS TO EKALAKA AND BAKER. THIS
ACTIVITY HAS BEEN SLOWLY DIMINISHING AS IT MOVES SOUTHEAST...AS
EXPECTED...BUT COULD SEE SOME LATE AFTERNOON DEVELOPMENT IN OUR
EAST NEAR SFC TROF AND IN A MOISTER AIRMASS. MIXING HAS INCREASED
AND WE ARE TAPPING INTO DRY MID LEVEL AIR OVER OUR NORTHWEST PARTS
WITH GUSTS AND DEWPTS IN THE 30S AT LIVINGSTON AND JUDITH GAP.
EXPECT AN INCREASED W-NW WIND TO PUSH EAST ACROSS THE PLAINS AS
NEXT CANADIAN COLD FRONT APPROACHES. FROPA WILL REACH BILLINGS
BRINGING ENHANCED NW WINDS BY EARLY THIS EVENING...BUT NOT ANY
SHOWER ACTIVITY PER THE DRY AIRMASS. TROWAL TO OUR NW WILL PUSH
SLOWLY SOUTH AND BRING SOME LIGHT PCPN TO OUR NW PARTS LATER
TONIGHT...BUT OTHERWISE A DRIER DOWNSLOPE WIND WILL PREVAIL FOR
MOST OF OUR CWA TONIGHT. CANADIAN FROPA WILL BRING A REINFORCING
SHOT OF SEASONABLY COOL AIR AND WE SHOULD SEE LOW TEMPS BACK TO
THE UPPER 40S TO MID 50S TONIGHT.
NORTHERN ROCKIES TROF WILL SPLIT WITH ENERGY DROPPING INTO THE
NORTHERN GREAT BASIN TOMORROW. OUR EAST SHOULD SEE STABLE
CONDITIONS UNDER CONFLUENT FLOW ALOFT...AND A MINIMAL CHANCE OF
SHOWERS. BETTER POTENTIAL FOR SHOWERS OR ISOLD TSTMS WILL BE OVER
OUR WESTERN MTNS AND FOOTHILLS UNDER COOLER AIR ALOFT...WITH
LIFTED INDICES NEAR -1C. TOMORROW SHOULD BE THE COOLEST DAY OF THE
CURRENT COOL SPELL WITH HIGHS IN THE 70S...FOLLOWED BY ANOTHER
SEASONABLY CHILLY NIGHT...THOUGH DAILY RECORDS FOR THE 19TH SEEM
TOO COOL TO REACH.
PV FROM GREAT BASIN TROF WILL TRACK ACROSS NORTHERN WY ON SUNDAY.
THIS WILL BE ENOUGH FOR A DIURNAL CHANCE OF SHOWERS/TSTMS OVER OUR
SOUTHERN HIGH TERRAIN AND PERHAPS SHERIDAN. FURTHER NORTH...A
DRIER WEST WIND SHOULD KEEP THE REMAINDER OF OUR CWA DRY WITH
EXPECTATION OF SOME HIGH-BASED CUMULUS ON SUNDAY SO HAVE ADJUSTED
POPS DOWN. THIS INCLUDES BILLINGS. DOWNSLOPE WARMING SHOULD ALLOW
FOR TEMPS BACK NEAR NORMAL AND IN THE MID TO UPPER 80S.
JKL
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
GLOBAL MODELS ARE IN DECENT AGREEMENT WITH KEEPING THE LONG TERM
WARM WITH DAILY CHANCES FOR THUNDERSTORMS. MONDAY SHOULD BE THE QUIETEST
DAY OF THE PERIOD AS WE WILL STILL BE UNDER THE INFLUENCE OF A
BUILDING RIDGE. AS THIS RIDGE BUILDS IT SHOULD BE PUSHED EASTWARD
BY A DIGGING TROUGH IN THE PACIFIC NORTHWEST. SOME MONSOONAL
MOISTURE COMBINED WITH SOUTHWESTERLY FLOW ALOFT SHOULD ALLOW
DECENT MOISTURE TO MAKE IT INTO THE AREA FROM TUESDAY ONWARD TO FUEL
AFTERNOON THUNDERSTORM DEVELOPMENT. TOWARDS THE END OF THE PERIOD
THE PACIFIC TROUGH CONTINUES TO AMPLIFY AND BETTER SHEAR/DYNAMICS
COULD INCREASE CHANCES FOR RAIN AND STRONGER THUNDERSTORMS
COMPARED TO MON...TUE AND WED. TEMPS AND RAIN CHANCES SHOULD BE
ABOVE CLIMATOLOGY THROUGH THE EXTENDED.
DOBBS
&&
.AVIATION...
PARTLY TO MOSTLY CLOUDY SKIES WILL PREVAIL FOR THE REMAINDER OF
THE AFTERNOON AND THROUGHOUT THE OVERNIGHT HOURS. AN ISOLATED
SHOWER AND MVFR CONDITION WILL BE POSSIBLE...MAINLY OVER THE
MOUNTAINS AND ADJACENT FOOTHILLS. OTHERWISE...VFR CONDITIONS WILL
PREVAIL. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 053/076 054/087 061/088 059/090 060/089 059/086 058/080
12/T 21/B 02/T 22/T 23/T 32/T 33/T
LVM 048/073 047/085 053/083 053/084 052/083 053/081 051/075
14/T 31/U 12/T 22/T 24/T 44/T 43/T
HDN 053/077 052/089 057/090 059/092 059/091 058/089 058/085
12/T 21/B 11/B 22/T 23/T 32/T 33/T
MLS 055/077 055/089 061/090 060/093 062/092 061/089 062/088
22/T 10/U 01/B 22/T 22/T 22/T 23/T
4BQ 055/076 053/087 059/089 058/092 060/090 059/089 058/090
22/T 11/B 11/B 12/T 32/T 22/T 23/T
BHK 053/074 052/085 058/087 055/087 059/089 058/085 058/088
21/N 10/U 01/B 22/T 32/T 22/T 23/T
SHR 050/071 047/083 054/084 054/087 055/086 054/085 055/085
23/T 32/T 12/T 22/T 33/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
635 PM CDT FRI JUL 17 2015
.SYNOPSIS...
ISSUED AT 320 PM CDT FRI JUL 17 2015
BROAD UPPER LEVEL RIDGE ACROSS THE SOUTHERN PLAINS AND SOUTHEASTERN
CONUS. MEANWHILE A UPPER LEVEL LOW IS MOVING ACROSS THE SOUTHERN
PLAINS OF CANADA WITH A TRAILING TROUGH OVER THE NORTHERN/CENTRAL
ROCKIES. SFC COLD FRONT IS PUSHING ACROSS THE NORTHERN HIGH PLAINS
THIS AFTERNOON. TEMPS ALONG AND AHEAD OF THE FRONT ARE IN THE MID
90S TO NEAR 100 WITH UPPER 70S TO MID 80S BEHIND THE FRONT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 320 PM CDT FRI JUL 17 2015
THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THE VICINITY OF THE FRONT
THIS EVENING AND CONTINUE OVER NIGHT AS THE FRONT PUSHES EAST.
MEANWHILE A SUBTLE MID LEVEL DISTURBANCE LIFTS IN THE WEST/SOUTHWEST
FLOW ACROSS NORTHEAST CO INTO SW NEB...WHICH WILL BE ANOTHER AREA OF
THUNDERSTORMS.
THE SFC LOW IS LOCATED IN S DAKOTA AND IS WHERE THE BEST SHEAR IS
LOCATED...HOWEVER STILL DECENT INTO NORTHERN NEBR WITH THE FRONT.
MODELS IN AGREEMENT WITH STORMS /WHICH HAVE ALREADY FIRED TO THE
WEST/ WILL CONTINUE TO INCREASE IN COVERAGE MOVE ACROSS THE AREA.
ROTATING STORMS ARE POSSIBLE AND SOME SEVERE WEATHER IS ANTICIPATED.
MOISTURE IS ON THE INCREASE WITH PWATS CLIMBING ABOVE 1.25 INCHES
AND LOCALLY BRIEF HEAVY RAINFALL WILL BE POSSIBLE. STORM MOTION IS
SHOULD BE FAIRLY QUICKLY AT 20 PLUS MPH.
AHEAD OF THE FRONT WITH THE SUBTLE WAVE A FEW ISOLATED TO SCATTERED
STORMS ARE EXPECTED. MODELS VARY GREATLY ON COVERAGE WHICH LEADS TO
A LOWER CONFIDENCE POP FORECAST. SHEAR NOT AS IMPRESSIVE AS FURTHER
NORTH...STILL 25 TO 35 KTS. MODELS HAVE CAPE VALUES AT 1000 TO 1500
J/KG SO SOME ISOLATED SEVERE CANNOT BE RULED OUT.
OVERNIGHT THE STORMS QUICKLY PUSH TO THE EAST WITH STORMS LAST TO
EXIT NORTH CENTRAL IN THE MORNING. LOWS COOLEST /UPPER 50S/ IN THE
WEST WHERE CLEARING WILL DEVELOP FIRST WHILE LOWER TO MID 60S
BENEATH THE LINGERING CLOUD COVER.
TOMORROW COOLER BEHIND THE FRONT WITH MOST AREAS IN THE 80S. MODELS
DEVELOP STORMS OVER THE HIGHER TERRAIN FOR THE AFTERNOON BUT EXPECT
THE AFTERNOON TO REMAIN DRY FOR OUR CWA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 PM CDT FRI JUL 17 2015
SAT NIGHT AND SUNDAY...STALLED FRONTAL POSITION WILL BE KEY TO
LOCATION OF NEW THUNDERSTORM DEVELOPMENT...AND MODELS HAVE THEIR
DIFFERENCES IN HOW THEY HANDLE THIS DEVELOPMENT OR LACK THEREOF. THE
GEM IS AN OUTLIER IN THAT IT DEVELOPS CONVECTION ALONG THE SFC FRONT
IN KS...WHILE OTHER MAIN MODELS DEVELOP TSRA IN THE POST-FRONTAL
UPSLOPE AREA CLOSER TO THE NEXT PV ANOMALY TO CONTRIBUTE TO THE
DEVELOPMENT WHICH SAGS SWD INTO WY SAT NIGHT. ASSUMING THERE IS ONLY
SUBTLE WAVES AVAILABLE TO INTERACT DIRECTLY TO ENHANCE CONVERGENCE
ALONG THE SFC FRONT...AND INSUFFICIENT FOR DEEP...MOIST
CONVECTION...WILL SIDE WITH THE POST-FRONTAL ENVIRONMENT AS MOST
FAVORABLE DUE TO THE BETTER UPPER FORCING TO FOCUS DEVLOPMENT ALONG
THE HIGHER TERRAIN AND BETTER ASSOCIATED SHEAR. ANY STORMS WOULD
THEN MOVE INTO THE WRN AND SOUTHERN FCST AREA SAT NIGHT. IN THIS
SCENARIO THE SRN AND WRN ZONES WOULD BE FAVORED AS HIGHEST CHANCES
AND THE FCST WAS TAILORED THAT WAY. MODELS SOMEWHAT SIMILAR IN
DEVELOPING WEAK INSTABILITY IN THE PANHANDLE BY SUNDAY AFTERNOON.
HOWEVER UPPER SUPPORT UNCLEAR AT THIS TIME SO EVEN WITH BETTER
THERMODYNAMIC POTENTIAL POSP SLIGHTLY LOWER FOR SUNDAY NIGHT. TEMPS
WOULD BE COOLER ON SUNDAY...ESPECIALLY IN THE SOUTH WHERE CLOUD
COVER FROM CONVECTIVE DEBRIS WOULD LINGER.
MON-THU...ON THE HEMISPHERIC SCALE...AS ONE UPPER LOW MOVES OVER THE
EXISTING RIDGE IN THE NORTH PACIFIC...A MORE IMPRESSIVE UPPER LOW
ROTATES NORTHEASTWARD AND DEEPENS IN THE BERING SEA THROUGH THE
WEEKEND. THE RESPONSE IS TO RETROGRADE THE UPPER RIDGE AXIS FROM
NEAR 140W TO NEAR 160W. THIS ALLOWS THE PREVIOUSLY MENTIONED UPPER
LOW TO MOVE SEWD ALONG THE BC COAST AND INTO THE PAC NW. THIS IN
TURN WILL SHIFT THE REMNANTS OF TS DOLORES EWD INTO THE CENTRAL CA
COAST. THE PV ANOMALY ASSOCIATED WITH DOLORES WILL MOVE EWD ACROSS
THE CENTRAL ROCKIES THROUGH MID WEEK. IN ADDITION...MID AND HIGH LEVEL
MOISTURE...AS EVIDENCED BY MOISTURE TRANSPORT VECTORS AND MIXING
RATIOS ON THE 320K SFC...WILL ALSO PROGRESS EWD ACROSS THE ROCKIES
AND INTO THE CENTRAL PLAINS BY LATE TUES INTO WED. ALTHOUGH MODELS
DIFFER SOMEWHAT WITH DETAILS...ESPECIALLY LOW LEVEL MOISTURE
AVAILABILITY...THUNDERSTORM CHANCES WILL INCREASE WITH BETTER UPPER
FORCING POTENTIAL IN THIS SETUP. ALSO...PW VALUES INCREASE TO NEAR
THE 90TH PERCENTILE BY LATE TUES AND WED THANKS TO THE INCREASE OF
MID LEVEL MOISTURE. COLD FRONTAL PASSAGE ON MONDAY WILL DRY THE LOW
LEVELS SIGNIFICANTLY /MODELS SUGGESTING U30S TO L40S DEW POINTS/ BUT
LOW LEVEL MOISTURE WILL EVENTUALLY RETURN TUES INTO WED AS RETURN
SRLY FLOW INCREASES. TEMPS WILL BE WARM ON MONDAY DESPITE EARLY
FRONTAL PASSAGE THANKS TO A DRIER AIRMASS IN PLACE...COOLING FOR
TUEASDAY AND WED...THEN RETURNING TO ABOVE AVE FOR THE REMAINDER OF
NEXT WEEK AS A TRANSITORY UPPER RIDGE BUILDS AHEAD OF THE NEXT LOW
PRESSURE SYSTEM WHICH FORMS IN THE WEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 635 PM CDT FRI JUL 17 2015
THE ONGOING TSTM ACTIVITY SHOULD GRADUALLY EXIT FROM WEST TO EAST
OVERNIGHT CLEARING THE ERN EDGE OF THE FCST AREA AROUND 07Z-09Z.
THE RAP AND NAM SUGGEST A BROAD AREA OF MVFR CIGS AND COLD AIR
STRATUS FORMING ACROSS WRN/NCNTL NEB 06Z-15Z. BUT THIS IS NOT
SUPPORTED BY THE SREF SO WE WILL WAIT A BIT ON INCORPORATING THIS
INTO THE FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...JWS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
358 AM CDT THU JUL 16 2015
.SYNOPSIS...
ISSUED AT 355 AM CDT THU JUL 16 2015
AT 08Z...A SMALL AREA OF SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE
EAST FROM AROUND THE THEDFORD AREA. A LARGE AREA OF ORGANIZED
SHOWERS AND THUNDERSTORMS CONTINUES TO MOVE NORTHEAST FROM PORTIONS
OF NRN KS AND SERN NEBR ACROSS WRN AND CNTRL IA AND NRN MO.
TEMPERATURES IN WRN NEBR RANGE FROM THE MID 60S TO LOW 70S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU JUL 16 2015
TODAY...ONGOING SMALL AREA OF SHOWERS AND THUNDERSTORMS AROUND
THEDFORD WILL CONTINUE TO MOVE EAST THIS MORNING AS WELL AS ISOLATED
SHOWERS OR THUNDERSTORMS IN FRONTIER AND CUSTER COUNTY. WILL CARRY A
SLIGHT CHANCE FOR THIS ACTIVITY TO CONTINUE UNTIL 15Z NEAR AND EAST
OF ONEILL THROUGH BROKEN BOW. THEN...AS A SURFACE TROUGH ADVANCES
EAST ACROSS WRN NEBR...THIS WILL BRING DOWNSLOPING WESTERLY WINDS UP
TO 10 KTS AND LOWER DEWPOINTS IN THE UPPER 40S TO LOWER 50S TO SWRN
NEBR AND PORTIONS OF THE CENTRAL SANDHILLS THIS AFTERNOON.
COINCIDING WITH PEAK HEATING...MOST SHORT TERM MODELS INDICATE
ISOLATED THUNDERSTORMS WILL ATTEMPT TO DEVELOP ALONG A DRYLINE
LOCATED NEAR WRN BOYD...HOLT AND WHEELER COUNTY. HIGHS TODAY WILL
WARM TO NEAR 90 NRN NEBR TO AROUND 95 I80 CORRIDOR AND SOUTH. SKIES
TO BE MOSTLY SUNNY WEST...AS OVERCAST SKIES IN THE EAST EARLY THIS
MORNING BECOME PARTLY TO MOSTLY SUNNY BY MIDDAY.
LOOKING SYNOPTICALLY ACROSS THE CONUS...THE UPPER RIDGE WILL BE
CENTERED OVER EAST TEXAS WITH A CLOSED LOW INDICATED IN ALBERTA
CANADA. UPPER FLOW NEARLY ZONAL FROM THE CENTRAL ROCKIES AND CENTRAL
PLAINS REGION. MONSOONAL MOISTURE WILL CONTINUE TO EXIST ACROSS THE
FOUR CORNERS REGION.
TONIGHT...SURFACE DEWPOINTS WILL RECOVER AND INCREASE TO TO NEAR 55
WEST AND 65 EAST. A DRY FORECAST...WITH ANY EARLY EVENING
THUNDERSTORMS EXPECTED TO RESIDE IN EASTERN NEBRASKA. LOWS FROM NEAR
60 ERN PNHDL TO NEAR 65 EAST. UPPER FLOW WILL REMAIN NEARLY ZONAL AS
AN UPPER TROUGH BEGINS TO DROP INTO THE PACIFIC NW EASTWARD INTO
MONTANA. SKIES TO REMAIN MOSTLY CLEAR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU JUL 16 2015
CHANCES FOR THUNDERSTORMS WILL BE THE MAIN FORECAST CHALLENGE DURING
THIS PERIOD...AS OVERALL MODEL AGREEMENT IS POOR IN REGARDS TO THE
TIMING OF POSSIBLE STORMS. THE MODELS DO SEEM TO BE IN GOOD
AGREEMENT SYNOPTICALLY...WITH THE SOUTHERN PLAINS UPPER LEVEL RIDGE
GRADUALLY EXPANDING AND BUILDING NORTHWARD INTO THE CENTRAL PLAINS
NEXT WEEK. THEY ALSO INDICATE A POTENT SHORTWAVE ALOFT TRANSLATING
EASTWARD ACROSS THE NORTHERN PLAINS/CANADA THIS WEEKEND. THIS WILL
DRIVE A COLD FRONT SOUTH ACROSS THE AREA...WITH AT LEAST A CHANCE
FOR SCATTERED THUNDERSTORMS AND COOLER TEMPERATURES BY SUNDAY.
LATEST INDICATIONS ARE THAT HIGHS SUNDAY MAY ONLY REACH THE UPPER
70S DUE TO A COMBINATION OF CLOUD COVER AND WEAK COLD AIR ADVECTION.
NEXT WEEK...MONDAY AND BEYOND...IS WHERE THE TIMING OF POSSIBLE
STORMS BECOMES DIFFICULT. THE FLOW ALOFT WILL BE WESTERLY ACROSS OUR
AREA ON NORTHERN EDGE OF THE SOUTHERN PLAINS UPPER LEVEL RIDGE. THE
WILDCARD FOR NEXT WEEK IS HURRICANE DOLORES. THE MODEL CONSENSUS IS
THAT DOLORES WILL MOVE NORTHWARD OFF THE WEST COAST OF BAJA
CALIFORNIA...EVENTUALLY MOVING ONSHORE CALIFORNIA SOMETIME EARLY TO
MIDWEEK. OF COURSE WHEN IT DOES MOVE ONSHORE THE WEST COAST IT WILL
BE IN A GREATLY WEAKENED STATE...WITH ONLY MID AND UPPER LEVEL
SUBTROPICAL MOISTURE REMAINING. THE WILD CARD IS HOW ALL THIS MID
AND UPPER LEVEL MOISTURE WILL BECOME ENTRAINED INTO THE WESTERLY
FLOW ALOFT AS IT MOVES EAST ACROSS THE CENTRAL PLAINS. THIS WILL
LIKELY ENHANCE CONVECTIVE CHANCES...BUT MODELS ARE IN POOR AGREEMENT
ON THE TIMING OF UPPER WAVES THAT WILL SERVE TO FOCUS TSTM
DEVELOPMENT. SO AT THIS POINT IT IS HARD TO PINPOINT WHEN THE HIGHER
CHANCES WILL BE...AND WILL OPT TO JUST CARRY LOW CHANCE POPS TUESDAY
AND BEYOND AS BOTH LOW LEVEL MOISTURE FROM THE SOUTHEAST AND THE
AFOREMENTIONED MID AND UPPER LEVEL MOISTURE WILL BE ON THE INCREASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1113 PM CDT WED JUL 15 2015
ISOLATED THUNDERSTORM COVERAGE IS EXPECTED...MAINLY WEST OF
HIGHWAY 61 AS STORMS WILL BE ENCOUNTERING MORE STABLE AIR AS THEY
MOVE EAST THROUGH THE PANHANDLE. THE SREF AND RAP SUGGEST STRATUS
AND PATCHY FOG MAY DEVELOP TONIGHT NEAR AND EAST OF HIGHWAY 83.
BURNOFF SHOULD OCCUR BY 15Z THURSDAY. OTHERWISE VFR IS EXPECTED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1113 PM CDT WED JUL 15 2015
.SYNOPSIS...
ISSUED AT 257 PM CDT WED JUL 15 2015
STAGNANT UPPER LEVEL SYNOPTIC PATTERN PERSISTS AS OF WEDNESDAY
AFTERNOON AS AN AREA OF HIGH PRESSURE PRESSURE REMAINS ANCHORED OVER
THE SOUTHERN PLAINS WITH A RIDGE AXIS UP THE CENTRAL CONUS...AND
LONG WAVE TROUGHS OVER THE WESTERN CONUS AND THE EAST COAST. AT THE
SURFACE A WEAK AREA OF LOW PRESSURE WAS CENTERED OVER NORTHERN
KANSAS WITH A WARM FRONT STRETCHED EASTWARD. LIGHT SOUTHEASTERLY
WIND NORTH OF THE LOW PRESSURE HAS STEADILY ADVECTED LOW LEVEL
MOISTURE BACK WESTWARD INTO THE SANDHILLS REGION THROUGH THE DAY. AN
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS HAS SLOWLY MOVED
NORTH ACROSS NORTHERN NEBRASKA THROUGH THE DAY. AS OF 20Z
REDEVELOPMENT OF ISOLATED STORMS IN THE NEBRASKA PANHANDLE WAS NOTED
ON RADAR.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 257 PM CDT WED JUL 15 2015
AREA OF SHOWERS AND STORMS ACROSS NORTHERN NEBRASKA WILL CONTINUE TO
SLOWLY PUSH NORTH. MODELS HAVE GENERALLY BEEN TOO AGGRESSIVE WITH
THE SPATIAL COVERAGE OF PRECIP THROUGH THE MORNING AND
AFTERNOON...AND THIS LOWERS CONFIDENCE IN THE FORECAST GOING
FORWARD. CLEARING TO THE SOUTHWEST HAS ALLOWED FOR TEMPERATURES TO
REACH INTO THE LOW 80S WITH SOUTHWEST WIND ADVECTING HIGHER
DEWPOINTS FROM THE MID 60S TO LOW 70S INTO WESTERN AND NORTH CENTRAL
NEBRASKA. STEEP LOW LEVEL LAPSE RATES AND MLCAPE VALUES RIGHT AROUND
1000-1500 J/KG SHOULD BE ENOUGH TO SPARK THE REDEVELOPMENT OF SOME
SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EVENING AS A WEAK
PV ANOMALY EJECTS NORTHEAST OUT OF SOUTHERN COLORADO. SO FAR TODAY
ISOLATED WEAK SHOWERS HAVE DEVELOPED MAINLY IN AREAS WHERE LOW LEVEL
MOISTURE CONVERGENCE IS ENHANCED ALONG REMNANT OUTFLOW BOUNDARIES
FROM CONVECTION LAST NIGHT AND THIS MORNING. THESE AREAS WILL
CONTINUE TO BE FAVORED AS INITIATION POINTS FOR POSSIBLE ISOLATED TO
SCATTERED DEEP CONVECTION THROUGH THIS EVENING...AS WELL AS THE
PANHANDLE AND WESTERN SANDHILLS WHERE DAYTIME HEATING HAS WORKED TO
ELIMINATE SURFACE BASED INHIBITION. A STRONG TO SEVERE STORM CANNOT
BE RULED OUT...BUT OBSERVATIONS AND TRENDS THROUGH THE DAY INDICATE
THAT MID LEVEL LAPSE RATES HAVE STRUGGLED TO RECOVER FROM EARLIER
CONVECTION...WHICH WILL LIKELY LIMIT THE LOCAL SEVERE POTENTIAL.
SREF...NAM...AND MOST HI-RES MODELS GENERALLY FAVOR AN AREA EAST OF
A NORTH PLATTE TO TAYLOR LINE FOR ANY SEVERE POTENTIAL LATER
TODAY...BUT THE GREATEST THREAT WILL STAY EAST OF THE CWA WHERE DEEP
LAYER SHEAR IS MUCH MORE FAVORABLE.
POPS CLEAR OUT EARLY IN THE OVERNIGHT HOURS AS DRIER AIR IN
THE MID TO UPPER LEVELS ADVECTS INTO THE CENTRAL HIGH PLAINS. FLOW
BECOMES QUASI-ZONAL ALOFT AS THE SOUTHERN PLAINS RIDGE CONTINUES TO
SLOWLY DE-AMPLIFY. MONSOONAL MOISTURE TAP SAGS SOUTH OF THE CWA WITH
CLEAR SKIES AND STRONG INSOLATION EXPECTED. WEAK FRONT TRACKS EAST
ACROSS THE STATE BUT MODELS HAVE TRENDED DRY OVER THE FORECAST AREA
DUE TO LITTLE UPPER LEVEL SUPPORT AND LIMITED MOISTURE. WARMING
TEMPERATURES FROM 850MB TO 700MB AND DEEP BOUNDARY LAYER MIXING WILL
PUSH HIGHS INTO THE UPPER 90S IN PARTS OF SOUTHWEST NEBRASKA.
TEMPERATURES WILL STAY 5 TO 10 DEGREES COOLER FURTHER NORTH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 257 PM CDT WED JUL 15 2015
THE EXTENDED PERIODS WILL LARGELY REMAIN UNDER THE INFLUENCE OF
BROAD HIGH PRESSURE THAT IS POISED TO REMAIN ACROSS THE SOUTHERN
PLAINS. MONSOONAL MOISTURE IS SHOWN TO BE PULLED NORTH AND
EVENTUALLY EAST AROUND THE HIGH...FIRST ACROSS THE CENTRAL ROCKIES
AND LATER ONTO THE PLAINS AS AN AREA OF LOW PRESSURE DEEPENS OVER
THE PAC NW LATE THIS WEEK AND WEEKEND. THE GFS AND EC DIFFER ON THE
HANDLING OF THE PAC NW TROUGH...SO BEYOND SATURDAY...THE FORECAST
GETS A BIT MUDDLED. REGARDLESS...THE MOISTURE WILL COMBINE WITH
PERIODIC ATMOSPHERIC IMPULSES AND FRONTAL PASSAGES TO PROVIDE FOR
CHANCES OF THUNDER. WILL RETAIN SLIGHT CHANCE POPS FRIDAY EVENING
INTO SATURDAY MORNING WHEN A STRONG NORTHERN STREAM SHORTWAVE PULLS
A COLD FRONT THROUGH THE CWA. THE FRONT MORE OR LESS WASHES OUT
SATURDAY...BUT ANOTHER STRONGER FRONT ARRIVES SATURDAY EVENING INTO
SUNDAY...SPARKING OFF ADDITIONAL THUNDERSTORM CHANCES. TEMPERATURES
WILL BE NOTICEABLY COOLER ON SUNDAY...WITH HIGHS IN THE LOWER 80S.
THUNDERSTORM CHANCES DECREASE EARLY NEXT WEEK AS THE REGION SITS IN
A POST FRONTAL REGIME WITH HIGH PRESSURE PARKED TO THE SOUTH OF THE
FORECAST AREA. WILL CONTINUE TO NEED TO WATCH THE MONSOONAL PLUME
AS IT WRAPS NORTHEAST AROUND THE HIGH...ANY SUBTLE IMPULSE WOULD
PROVIDE FOR THE RETURN OF SHOWERS OR THUNDERSTORMS...BUT WIDESPREAD
QPF IS NOT LIKELY EARLY NEXT WEEK. AFTER THE BRIEF COOLDOWN ON
SUNDAY...TEMPERATURES WILL REBOUND EARLY NEXT WEEK AND REMAIN
SEASONAL THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1113 PM CDT WED JUL 15 2015
ISOLATED THUNDERSTORM COVERAGE IS EXPECTED...MAINLY WEST OF
HIGHWAY 61 AS STORMS WILL BE ENCOUNTERING MORE STABLE AIR AS THEY
MOVE EAST THROUGH THE PANHANDLE. THE SREF AND RAP SUGGEST STRATUS
AND PATCHY FOG MAY DEVELOP TONIGHT NEAR AND EAST OF HIGHWAY 83.
BURNOFF SHOULD OCCUR BY 15Z THURSDAY. OTHERWISE VFR IS EXPECTED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MARTIN
SHORT TERM...MARTIN
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1020 AM PDT THU JUL 16 2015
.SYNOPSIS...A DRY SOUTHWEST FLOW ALOFT WILL GRADUALLY GIVE WAY TO
MOISTURE ASSOCIATED WITH HURRICANE DOLORES MOVING UP FROM THE GULF
OF CALIFORNIA FRIDAY THROUGH THE WEEKEND. THIS WILL RESULT IN PLENTY
OF CLOUDS ALONG WITH THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS...SOME OF WHICH COULD PRODUCE LOCALLY HEAVY RAIN.
DRIER CONDITIONS WILL RETURN BY THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...NO IMMEDIATE CHANGES NEEDED WITH THE FORECAST AREA UNDER A
CLEAR SKY AND SIMILAR CONDITIONS TO YESTERDAY. THE FOCUS WILL BE ON
THE MOISTURE SURGE THIS WEEKEND AND THE LATEST AVAILABLE MODEL
SOLUTIONS SUPPORT THE GENERAL TRENDS IN THE INHERITED FORECAST. WILL
BE DOING SOME FINE TUNING AS MORE DATA ROLLS IN.
&&
.PREV DISCUSSION...
245 AM PDT THU JUL 16 2015
.SHORT TERM...THROUGH SATURDAY NIGHT.
DRY SOUTHWESTERLY FLOW PERSISTS TODAY WITH MOISTURE FROM THE SOUTH
TRYING TO SEEP IN ALONG THE COLORADO RIVER BUT STRUGGLING TO MAKE
MUCH NORTHWARD PROGRESS. VAD WIND PROFILER FROM YUMA INDICATES THE
CURRENT MOISTURE SURGE IS FAIRLY SHALLOW SO WE WILL NEED TO WAIT AT
LEAST ANOTHER DAY BEFORE ANY SUBSTANTIAL MOISTURE INCREASE IMPACTS
THE AREA. THE FORECAST FOR TODAY IS A DRY AND WARM ONE WITH THE ONLY
CHANCE FOR PRECIPITATION LIMITED TO THE SIERRA WHERE SEVERAL MEMBERS
OF MODEL GUIDANCE AS WELL AS EARLY MORNING RUNS OF THE HRRR BREAK
OUT SOME ACTIVITY THIS AFTERNOON WEST OF BISHOP. THIS SEEMS
REASONABLE WITH A WEAK UPPER LEVEL CIRCULATION MOVING ACROSS CENTRAL
CALIFORNIA THIS AFTERNOON...SO I ADDED SLIGHT CHANCES FOR THUNDER TO
THAT AREA TO ACCOUNT FOR THIS. WE WILL ALSO NEED TO WATCH FAR
NORTHEASTERN MOHAVE COUNTY NEAR PIPE SPRING NATIONAL MONUMENT WHERE
SOME ISOLATED LIGHT SHOWER ACTIVITY COULD DEVELOP LATE IN THE
EVENING...BUT I BELIEVE BETTER CHANCES WILL BE JUST EAST OF THE AREA
AND I HAVE LEFT POPS OUT OF THE FORECAST FOR NOW.
ON FRIDAY...SIGNIFICANT CHANGES WILL BEGIN TO TAKE SHAPE AS THE MUCH
ANTICIPATED GULF SURGE COURTESY OF HURRICANE DOLORES BEGINS TO CREEP
INTO SOUTHERN PORTIONS OF THE FORECAST AREA. IN FACT...BY FRIDAY
AFTERNOON PRECIPITABLE WATER VALUES ENCROACHING 1.50 INCHES WILL BE
NUDGING INTO THE LAKE HAVASU AREA WITH OVER ONE INCH ALL THE WAY UP
TO LAKE MEAD. THIS WILL MAKE SHOWERS AND THUNDERSTORMS A GOOD
POSSIBILITY PARTICULARLY ACROSS MOHAVE COUNTY...BUT ALSO AS FAR WEST
AS LAKE MEAD...NEEDLES...AND LAKE HAVASU. I PULLED POPS A BIT
FURTHER WEST TO ACCOUNT FOR THIS. IN ADDITION...SOME WESTERLY SHEAR
WILL BE IN PLACE SO SOME PULSE SEVERE STORMS WILL BE POSSIBLE
CONTAINING GUSTY WINDS AND SMALL HAIL IN ADDITION TO THE THREAT OF
FLASH FLOODING.
MOISTURE WILL CONTINUE TO FLOOD INTO THE AREA FRIDAY NIGHT INTO
SATURDAY MORNING...AT WHICH POINT THE ATMOSPHERE WILL BE QUITE MOIST
FROM I-15 SOUTH AND EAST. WIDESPREAD CLOUDS AND POCKETS OF RAIN
COULD HINDER INSTABILITY SOMEWHAT BUT THE PERSISTENT SOUTHWESTERLY
SHEAR HAS ME CONCERNED ABOUT OROGRAPHIC ENHANCEMENT OF PRECIPITATION
WITHIN A VERY MOIST AIRMASS...PARTICULARLY ACROSS MOHAVE COUNTY.
FLASH FLOODING RISK WILL NEED TO BE MONITORED CAREFULLY FRIDAY
AFTERNOON THROUGH SATURDAY. OTHERWISE...GRAY AND GLOOMY DAY
EXPECTED ELSEWHERE WITH CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS
PARTICULARLY ALONG AND SOUTH OF INTERSTATE 15.
.LONG TERM...SUNDAY THROUGH WEDNESDAY.
MOISTURE THAT GETS DRAWN NORTHWARD INTO THE REGION FRIDAY-SATURDAY
WILL STILL BE IN PLAY SUNDAY AND MONDAY. THERE REMAINS DIFFERENCES
BETWEEN MODELS IN THE HANDLING OF A TROUGH MOVING THROUGH THE
NORTHERN ROCKIES/PAC NW. THE MAJOR DIFFERENCE IS IN THE HANDLING OF
A PIECE OF ENERGY WHICH IS LEFT BEHIND OVER NORTHERN
CALIFORNIA/NORTHERN NEVADA SUNDAY AS TROUGH SHEARS OUT TO THE EAST.
ALSO...THE ECMWF STILL TAKES THE MID-LEVEL REMNANT CIRCULATION FROM
DOLORES PHASING IT WITH THE AFOREMENTIONED ENERGY OVER NORTHERN
CALIFORNIA MONDAY. THE GFS KEEPS THE FEATURES SEPARATE DEPICTING A
TROUGH OVER NEVADA WITH THE REMNANTS OF DOLORES WEST OF SOUTHERN
CALIFORNIA. BETTER THAN AVERAGE CONFIDENCE IN SEEING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS BOTH DAYS. MORE UNCERTAINTY
EXIST TUESDAY AND WEDNESDAY DUE TO THE HANDLING OF THE REMNANTS OF
DOLORES. HOWEVER IT LOOKS LIKE AN INCREASING SOUTHWEST FLOW SHOULD
BRING A DECREASE IN STORM COVERAGE CONFINING ANY MENTION OF STORMS
TO MOHAVE COUNTY AND NORTHERN LINCOLN COUNTY TUESDAY AND WEDNESDAY.
INCREASED CLOUD COVER AND HIGHER HUMIDITIES WILL SUPPRESS
TEMPERATURES ON SUNDAY AND MONDAY. READINGS WILL WARM CLOSER TO
NORMAL ON TUESDAY AND WEDNESDAY. BEYOND WEDNESDAY, MODELS SHOWING
ANOTHER TROPICAL SYSTEM MOVING NORTHWEST PARALLEL TO THE BAJA
PENINSULA NEXT FRIDAY AND SATURDAY. COULD NEXT WEEKEND BE SIMILAR TO
THIS WEEKEND. STAY TUNED!
&&
.AVIATION...FOR MCCARRAN...SUNNY AND DRY TODAY WITH PREDOMINANTLY
SOUTHERLY WINDS ONCE AGAIN. A PERIOD OF VARIABILITY WITH LIGHT
EASTERLY COMPONENTS WILL EXIST BETWEEN 15Z AND 20Z BEFORE A PUSH OF
STRONGER SOUTH-SOUTHWESTERLY WINDS OVERTAKES THE VALLEY OF 10-15KTS
WITH GUSTS TO 25KTS. WIND SPEEDS WILL DECREASE AFTER SUNSET.
INCREASING SHOWER AND THUNDERSTORM ACTIVITY EXPECTED FRIDAY ONWARD.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...MOSTLY CLEAR CONDITIONS EXPECTED ACROSS THE REGION WITH
ISOLATED THUNDERSTORMS POSSIBLE ALONG THE SIERRA NEAR KBIH. SOUTH
WINDS OF 10-15KTS WIH GUSTS TO 25 KTS WILL BE POSSIBLE ACROSS THE
REGION WHICH WILL DECREASE AFTER SUNSET. INCREASING SHOWER AND
THUNDERSTORM ACTIVITY EXPECTED FRIDAY ONWARD....ESPECIALLY EAST AND
SOUTH A KDAG-KLAS-KSGU LINE.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...ADAIR
SHORT TERM/AVIATION...OUTLER
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
245 AM PDT THU JUL 16 2015
.SYNOPSIS...A DRY SOUTHWEST FLOW ALOFT WILL GRADUALLY GIVE WAY TO
MOISTURE ASSOCIATED WITH HURRICANE DOLORES MOVING UP FROM THE GULF
OF CALIFORNIA FRIDAY THROUGH THE WEEKEND. THIS WILL RESULT IN PLENTY
OF CLOUDS ALONG WITH THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS...SOME OF WHICH COULD PRODUCE LOCALLY HEAVY RAIN.
DRIER CONDITIONS WILL RETURN BY THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...THROUGH SATURDAY NIGHT.
DRY SOUTHWESTERLY FLOW PERSISTS TODAY WITH MOISTURE FROM THE SOUTH
TRYING TO SEEP IN ALONG THE COLORADO RIVER BUT STRUGGLING TO MAKE
MUCH NORTHWARD PROGRESS. VAD WIND PROFILER FROM YUMA INDICATES THE
CURRENT MOISTURE SURGE IS FAIRLY SHALLOW SO WE WILL NEED TO WAIT AT
LEAST ANOTHER DAY BEFORE ANY SUBSTANCIAL MOISTURE INCREASE IMPACTS
THE AREA. THE FORECAST FOR TODAY IS A DRY AND WARM ONE WITH THE ONLY
CHANCE FOR PRECIPITATION LIMITED TO THE SIERRA WHERE SEVERAL MEMBERS
OF MODEL GUIDANCE AS WELL AS EARLY MORNING RUNS OF THE HRRR BREAK
OUT SOME ACTIVITY THIS AFTERNOON WEST OF BISHOP. THIS SEEMS
REASONABLE WITH A WEAK UPPER LEVEL CIRCULATION MOVING ACROSS CENTRAL
CALIFORNIA THIS AFTERNOON...SO I ADDED SLIGHT CHANCES FOR THUNDER TO
THAT AREA TO ACCOUNT FOR THIS. WE WILL ALSO NEED TO WATCH FAR
NORTHEASTERN MOHAVE COUNTY NEAR PIPE SPRING NATIONAL MONUMENT WHERE
SOME ISOLATED LIGHT SHOWER ACTIVITY COULD DEVELOP LATE IN THE
EVENING...BUT I BELIEVE BETTER CHANCES WILL BE JUST EAST OF THE AREA
AND I HAVE LEFT POPS OUT OF THE FORECAST FOR NOW.
ON FRIDAY...SIGNIFICANT CHANGES WILL BEGIN TO TAKE SHAPE AS THE MUCH
ANTICIPATED GULF SURGE COURTESY OF HURRICANE DOLORES BEGINS TO CREEP
INTO SOUTHERN PORTIONS OF THE FORECAST AREA. IN FACT...BY FRIDAY
AFTERNOON PRECIPITABLE WATER VALUES ENCROACHING 1.50 INCHES WILL BE
NUDGING INTO THE LAKE HAVASU AREA WITH OVER ONE INCH ALL THE WAY UP
TO LAKE MEAD. THIS WILL MAKE SHOWERS AND THUNDERSTORMS A GOOD
POSSIBILITY PARTICULARLY ACROSS MOHAVE COUNTY...BUT ALSO AS FAR WEST
AS LAKE MEAD...NEEDLES...AND LAKE HAVASU. I PULLED POPS A BIT
FURTHER WEST TO ACCOUNT FOR THIS. IN ADDITION...SOME WESTERLY SHEAR
WILL BE IN PLACE SO SOME PULSE SEVERE STORMS WILL BE POSSIBLE
CONTAINING GUSTY WINDS AND SMALL HAIL IN ADDITION TO THE THREAT OF
FLASH FLOODING.
MOISTURE WILL CONTINUE TO FLOOD INTO THE AREA FRIDAY NIGHT INTO
SATURDAY MORNING...AT WHICH POINT THE ATMOSPHERE WILL BE QUITE MOIST
FROM I-15 SOUTH AND EAST. WIDESPREAD CLOUDS AND POCKETS OF RAIN
COULD HINDER INSTABILITY SOMEWHAT BUT THE PERSISTENT SOUTHWESTERLY
SHEAR HAS ME CONCERNED ABOUT OROGRAPHIC ENHANCEMENT OF PRECIPITATION
WITHIN A VERY MOIST AIRMASS...PARTICULARLY ACROSS MOHAVE COUNTY.
FLASH FLOODING RISK WILL NEED TO BE MONITORED CAREFULLY FRIDAY
AFTERNOON THROUGH SATURDAY. OTHERWISE...GRAY AND GLOOMY DAY
EXPECTED ELSEWHERE WITH CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS
PARTICULARLY ALONG AND SOUTH OF INTERSTATE 15.
.LONG TERM...SUNDAY THROUGH WEDNESDAY.
MOISTURE THAT GETS DRAWN NORTHWARD INTO THE REGION FRIDAY-SATURDAY
WILL STILL BE IN PLAY SUNDAY AND MONDAY. THERE REMAINS DIFFERENCES
BETWEEN MODELS IN THE HANDLING OF A TROUGH MOVING THROUGH THE
NORTHERN ROCKIES/PAC NW. THE MAJOR DIFFERENCE IS IN THE HANDLING OF
A PIECE OF ENERGY WHICH IS LEFT BEHIND OVER NORTHERN
CALIFORNIA/NORTHERN NEVADA SUNDAY AS TROUGH SHEARS OUT TO THE EAST.
ALSO...THE ECMWF STILL TAKES THE MID-LEVEL REMNANT CIRCULATION FROM
DOLORES PHASING IT WITH THE AFOREMENTIONED ENERGY OVER NORTHERN
CALIFORNIA MONDAY. THE GFS KEEPS THE FEATURES SEPARATE DEPICTING A
TROUGH OVER NEVADA WITH THE REMNANTS OF DOLORES WEST OF SOUTHERN
CALIFORNIA. BETTER THAN AVERAGE CONFIDENCE IN SEEING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS BOTH DAYS. MORE UNCERTAINTY
EXIST TUESDAY AND WEDNESDAY DUE TO THE HANDLING OF THE REMNANTS OF
DOLORES. HOWEVER IT LOOKS LIKE AN INCREASING SOUTHWEST FLOW SHOULD
BRING A DECREASE IN STORM COVERAGE CONFINING ANY MENTION OF STORMS
TO MOHAVE COUNTY AND NORTHERN LINCOLN COUNTY TUESDAY AND WEDNESDAY.
INCREASED CLOUD COVER AND HIGHER HUMIDITIES WILL SUPPRESS
TEMPERATURES ON SUNDAY AND MONDAY. READINGS WILL WARM CLOSER TO
NORMAL ON TUESDAY AND WEDNESDAY. BEYOND WEDNESDAY, MODELS SHOWING
ANOTHER TROPICAL SYSTEM MOVING NORTHWEST PARALLEL TO THE BAJA
PENINSULA NEXT FRIDAY AND SATURDAY. COULD NEXT WEEKEND BE SIMILAR TO
THIS WEEKEND. STAY TUNED!
&&
.AVIATION...FOR MCCARRAN...SUNNY AND DRY TODAY WITH PREDOMINANTLY
SOUTHERLY WINDS ONCE AGAIN. A PERIOD OF VARIABILITY WITH LIGHT
EASTERLY COMPONENTS WILL EXIST BETWEEN 15Z AND 20Z BEFORE A PUSH OF
STRONGER SOUTH-SOUTHWESTERLY WINDS OVERTAKES THE VALLEY OF 10-15KTS
WITH GUSTS TO 25KTS. WIND SPEEDS WILL DECREASE AFTER SUNSET.
INCREASING SHOWER AND THUNDERSTORM ACTIVITY EXPECTED FRIDAY ONWARD.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...MOSTLY CLEAR CONDITIONS EXPECTED ACROSS THE REGION WITH
ISOLATED THUNDERSTORMS POSSIBLE ALONG THE SIERRA NEAR KBIH. SOUTH
WINDS OF 10-15KTS WIH GUSTS TO 25 KTS WILL BE POSSIBLE ACROSS THE
REGION WHICH WILL DECREASE AFTER SUNSET. INCREASING SHOWER AND
THUNDERSTORM ACTIVITY EXPECTED FRIDAY ONWARD....ESPECIALLY EAST AND
SOUTH A KDAG-KLAS-KSGU LINE.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...OUTLER
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1033 PM EDT FRI JUL 17 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
AS OF 1033 PM EDT FRIDAY...THOUGH VIRGA OR VERY LIGHT SHOWERS
PREVAIL ACROSS MUCH OF VERMONT, STEADIER BAND OF RAIN HAS
DEVELOPED EXTENDING ALONG A MSS-SLK-GFL LINE AND WILL MOVE
EASTWARD INTO THE CHAMPLAIN VALLEY BEFORE MIDNIGHT, AND ACROSS THE
REST OF VERMONT AFTER MIDNIGHT. IN THE WAKE OF THIS WARM- FRONTAL
RAIN IS MORE SPOTTY, SCATTERED SHOWERS. UPSTREAM DETROIT RAOB
SHOWS SOME STEEPER MID- LEVEL LAPSE RATES IN A BROADLY CYCLONIC
WEST FLOW. THE LATEST RAP FORECAST PICKS UP ON THESE STEEPER LAPSE
RATES IN ITS DEPICTION OF WEAK NEGATIVE SHOWALTER INDICES
ADVECTING IN THROUGH THE OVERNIGHT. REGARDING POPS AND WEATHER,
I`VE ADDED IN SLIGHT CHANCE THUNDER TO THE GRIDS AFTER MIDNIGHT
ONCE THE MORE FOCUSED WARM FRONTAL RAIN LIFTS EAST.
CURRENT TEMPS GENERALLY IN THE MID 60S TO LOW 70S, WITH SOME
SLIGHT INCREASE IN DEWPOINTS SINCE EARLY EVENING - INTO THE UPPER
50S TO MID 60S. TEMPS WILL BE VERY SLOW TO FALL GIVEN SOUTH
WINDS, WARM ADVECTION REGIME AND OVERCAST SKIES. DEWPOINTS WILL
ALSO GRADUALLY BE ON THE CLIMB WITH MANY AREAS LIKELY TO BE IN THE
60S BY SUNRISE. SO ITS GOING TO BE AN INCREASINGLY MORE HUMID
NIGHT, WITH LOWS IN THE 60S.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS WITH MID-HIGH CEILINGS WILL
QUICKLY LOWER WITH ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z
AND 03Z SATURDAY. CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR
FOR A BRIEF PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION
AFTER 09-12Z WITH MVFR CIGS TRENDING TO VFR BY 18Z. HOWEVER...SOME
-SHRA/-TSRA MAY DEVELOP AFT 18Z BUT ARE NOT CURRENTLY IN TAFS DUE
TO UNCERTAINTY IN COVERAGE/TIME. SOUTHERLY WINDS 5-10KTS THRU 12Z
AND UP TO 15-20 KTS IN CHAMPLAON VALLEY AFT 12Z SAT.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND
THUNDERSTORMS, MAINLY ACROSS VT ENDING.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT
KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR
FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE
AFTERNOON -SHRA.
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...LOCONTO
SHORT TERM...DEAL
LONG TERM...LAHIFF
AVIATION...LAHIFF/SLW
MARINE...MV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
818 PM EDT FRI JUL 17 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 9 AM SATURDAY MORNING/...
AS OF 712 PM EDT FRIDAY...DESPITE A REASONABLE ENOUGH COMPOSITE
RADAR PRESENTATION AND SUFFICIENT LIFT OWING TO WARM-FRONTAL
ASCENT, THERE REALLY HASN`T BEEN MUCH IN THE WAY OF QPF (AS
CONFIRMED BY UPSTREAM METARS) WITH THE RADAR RETURNS. ACROSS
WESTERN/CENTRAL NY STATE, I COULD ONLY FIND ROC AND ART AS THE
ONLY LOCATIONS WHICH HAVE ACTUALLY MEASURED. SUB-CLOUD DRY AIR
RESULTING IN VIRGA PROBABLY ACCOUNTS FOR SOME OF THAT, AND IT
LOOKS TO BE ONE OF THOSE HIGH-POP/LOW-QPF TYPE SCENARIOS THAN A
REAL WETTING RAINFALL. USING THESE TRENDS, I`VE DECIDED TO LOWER
QPF THROUGH MIDNIGHT BY ROUGHLY HALF (0.05" - 0.20"), BUT ALSO GO
WITH OCCASIONAL SHOWERS THROUGH MIDNIGHT. USED LATEST HRRR TO
GUIDE TIMING - WHICH BRINGS OCCASIONAL SHOWERS THROUGH MIDNIGHT
ACROSS THE NORTH COUNTRY. ANY LEFTOVER SHOWERS THEN BECOME MORE
SPOTTY OVERNIGHT AS THE WARM FRONT LIFTS EAST.
WARM-AIR AND MOISTURE ADVECTION ALSO WILL BE STEADILY INCREASING,
WITH A NOTICEABLE INCREASE IN DEWPOINTS (INTO THE 60S) AFTER
MIDNIGHT. LOWS LOOKED A BIT LOW GIVEN A SOUTH WIND, AFOREMENTIONED
WARM ADVECTION AND OVERCAST SKIES, SO I DID RAISE THESE BY A FEW
DEGREES USING A CONSENSUS BLEND. THAT BRINGS LOWS INTO THE 60S,
COOLEST IN THE NORTHEAST KINGDOM WITH INCREASING HUMIDITY LEVELS
THROUGH SUNRISE.
&&
.SHORT TERM /9 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS WITH MID-HIGH CEILINGS WILL
QUICKLY LOWER WITH ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z
AND 03Z SATURDAY. CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR
FOR A BRIEF PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION
AFTER 09-12Z WITH MVFR CIGS TRENDING TO VFR BY 18Z. HOWEVER...SOME
-SHRA/-TSRA MAY DEVELOP AFT 18Z BUT ARE NOT CURRENTLY IN TAFS DUE
TO UNCERTAINTY IN COVERAGE/TIME. SOUTHERLY WINDS 5-10KTS THRU 12Z
AND UP TO 15-20 KTS IN CHAMPLAON VALLEY AFT 12Z SAT.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND
THUNDERSTORMS, MAINLY ACROSS VT ENDING.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT
KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR
FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE
AFTERNOON -SHRA.
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...DEAL/LOCONTO/MV
SHORT TERM...DEAL
LONG TERM...LAHIFF
AVIATION...LAHIFF/SLW
MARINE...MV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
713 PM EDT FRI JUL 17 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 712 PM EDT FRIDAY...DESPITE A REASONABLE ENOUGH COMPOSITE
RADAR PRESENTATION AND SUFFICIENT LIFT OWING TO WARM-FRONTAL
ASCENT, THERE REALLY HASN`T BEEN MUCH IN THE WAY OF QPF (AS
CONFIRMED BY UPSTREAM METARS) WITH THE RADAR RETURNS. ACROSS
WESTERN/CENTRAL NY STATE, I COULD ONLY FIND ROC AND ART AS THE
ONLY LOCATIONS WHICH HAVE ACTUALLY MEASURED. SUB-CLOUD DRY AIR
RESULTING IN VIRGA PROBABLY ACCOUNTS FOR SOME OF THAT, AND IT
LOOKS TO BE ONE OF THOSE HIGH-POP/LOW-QPF TYPE SCENARIOS THAN A
REAL WETTING RAINFALL. USING THESE TRENDS, I`VE DECIDED TO LOWER
QPF THROUGH MIDNIGHT BY ROUGHLY HALF (0.05" - 0.20"), BUT ALSO GO
WITH OCCASIONAL SHOWERS THROUGH MIDNIGHT. USED LATEST HRRR TO
GUIDE TIMING - WHICH BRINGS OCCASIONAL SHOWERS THROUGH MIDNIGHT
ACROSS THE NORTH COUNTRY. ANY LEFTOVER SHOWERS THEN BECOME MORE
SPOTTY OVERNIGHT AS THE WARM FRONT LIFTS EAST.
WARM-AIR AND MOISTURE ADVECTION ALSO WILL BE STEADILY INCREASING,
WITH A NOTICEABLE INCREASE IN DEWPOINTS (INTO THE 60S) AFTER
MIDNIGHT. LOWS LOOKED A BIT LOW GIVEN A SOUTH WIND, AFOREMENTIONED
WARM ADVECTION AND OVERCAST SKIES, SO I DID RAISE THESE BY A FEW
DEGREES USING A CONSENSUS BLEND. THAT BRINGS LOWS INTO THE 60S,
COOLEST IN THE NORTHEAST KINGDOM WITH INCREASING HUMIDITY LEVELS
THROUGH SUNRISE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY NIGHT/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION
THROUGH THE DAYLIGHT HOURS WITH MID-HIGH CLOUDS CONTINUING TO
INCREASE AND SLOWLY LOWER FROM WEST TO EAST AHEAD OF A WARM FRONT.
ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z AND 03Z SATURDAY, WITH
CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR FOR A BRIEF
PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION AFTER 09-12Z
WITH MVFR CIGS TRENDING TO VFR BY 18Z. SOUTHERLY WINDS SLIGHTLY
GUSTY THIS AFTERNOON, LIGHTER 5-10KTS AFTER 00Z.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND THUNDERSTORMS, MAINLY
ACROSS VT.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE AFTERNOON -SHRA.
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...DEAL/LOCONTO/MV
SHORT TERM...DEAL
LONG TERM...LAHIFF
AVIATION...LAHIFF
MARINE...MV
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
957 AM EDT THU JUL 16 2015
.SYNOPSIS...
COLD FRONT WILL CONTINUE TO PROGRESS OFF THE COAST AND STALL
OFFSHORE THIS MORNING. WEAK HIGH PRESSURE WILL BRING SEASONABLE
TEMPS AND MOSTLY DRY WEATHER THROUGH FRIDAY. AN UPPER RIDGE WILL
COMBINE WITH BERMUDA HIGH PRESSURE BEGINNING SATURDAY TO BRING A
RETURN OF HEAT AND HUMIDITY WITH AFTERNOON THUNDERSTORMS THROUGH
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM THURSDAY...12Z SOUNDINGS FROM MHX/CHS INDICATE
MARGINAL INSTABILITY AND SUFFICIENT LOW-LEVEL MOISTURE TO SUPPORT
WIDELY SCATTERED CONVECTION THIS AFTERNOON. MLCAPE MODIFIES TO
1500 J/KG WITH A LI TO -4C WITH MAX TEMPS EXPECTED TO REACH LOW
90S. ANY DEVELOPMENT IS EXPECTED TO REMAIN SUB-SEVERE AND INITIATE
ALONG SURFACE BASED BOUNDARIES SUCH AS THE RESULTANT SEA BREEZE
AND POSSIBLE OUTFLOWS...AND IN THE VICINITY OF THE FRONTAL
BOUNDARY WHICH HAD ALREADY PUSHED JUST SOUTH OF THE CWA AS OF
12Z. ANY TWEAKS TO THE CURRENT FORECAST WILL BE MINOR.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...ANOTHER GORGEOUS MID-JULY DAY EXPECTED
FRIDAY WITH SEASONABLE TEMPS AND RELATIVELY LOWERED HUMIDITY THANKS
TO DRY W/NW FLOW THROUGH MUCH OF THE COLUMN AND STILL COOL NE
SURFACE FLOW BEHIND WEDNESDAY NIGHTS COLD FRONT. SOUNDINGS SHOW
PWATS DOWN TO 1.5 INCHES OR LESS...WHICH COMBINED WITH SUBSIDENCE
BENEATH AN AMPLIFYING MID-LEVEL RIDGE WILL INHIBIT CONVECTION FRIDAY
WHILE PERMITTING AMPLE SUNSHINE. TEMPS FRIDAY WILL BE A DEGREE OR
TWO EITHER SIDE OF 90 FOR HIGHS...AND IN THE LOW 70S FOR MINS.
500MB RIDGE EXPANDS FROM THE ARKLATEX REGION SATURDAY...BULGING NE
INTO THE MID-ATLANTIC. THIS DRIVES INCREASING HEIGHTS
LOCALLY...WHICH COMBINE WITH SLOWLY RETURNING SW FLOW AROUND BERMUDA
HIGH PRESSURE TO CREATE A SIGNIFICANTLY WARMER AND MORE HUMID DAY
SATURDAY. THE RIDGING ALOFT WILL TEND TO SQUELCH MOST
CONVECTION...BUT SCHC POP IS NEEDED ALONG THE TYPICAL BOUNDARIES DUE
TO STRONG SURFACE HEATING CREATING A HIGHLY UNSTABLE COLUMN. DO NOT
EXPECTED MORE THAN ISOLATED COVERAGE DUE TO THE RIDGING ALOFT...BUT
A FEW STORMS ALONG THE SEA BREEZE AND PIEDMONT TROUGH ARE
POSSIBLE...WANING AFTER DARK IN THE USUAL FASHION. HIGHS SATURDAY
WILL BE ABOUT 3-5 DEGREES WARMER THAN FRIDAY...MID 90S WEST OF I-95
TO AROUND 90 AT THE COAST. LOWS WILL AGAIN DROP INTO THE LOW
70S...MID 70S AT THE BEACHES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...RIDGING CENTERED OVER THE NW GULF COAST
REGION WILL EXPAND ACROSS MOST OF THE SOUTHERN TIER THIS COMING
WEEK...WITH A SLIGHTLY SW TO NE RIDGE AXIS CREATING ABOVE NORMAL
TEMPS LOCALLY. AS THE RIDGE CENTER REMAINS WEST OF THE
CAROLINAS...MID-LEVEL FLOW WILL BE GENERALLY W/NW THROUGH WEDNESDAY
SO WEAK IMPULSES EMBEDDED WITHIN THE FLOW WILL HELP SPAWN CONVECTION
EACH AFTN/EVE...BUT NO SIGNIFICANT FORCING APPEARS ON THE HORIZON
AND ONLY TYPICAL SUMMERTIME ACTIVITY IS EXPECTED. WITH HEIGHTS
BULGING ALOFT TEMPS WILL BE WELL ABOVE NORMAL MOST OF NEXT WEEK WITH
WIDESPREAD MID-90S EACH AFTN AWAY FROM THE COAST...AND LOWS IN THE
MID 70S. A TROUGH/COLD FRONT WILL APPROACH AT THE TAIL END OF THE
PERIOD BUT ANY IMPACTS LOOK TO HOLD OFF UNTIL BEYOND THE EXTENDED.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...ANY PATCHY MVFR FOG WILL QUICKLY MIX OUT WITHIN THE
HOUR. FRONTAL BOUNDARY SOUTH OF THE REGION WILL LIKELY STAY THERE
WHILE IT SLOWLY WEAKENS. THE HRRR MODEL SHOWS SEA BREEZE ACTIVITY
THIS AFTERNOON. THINK IT WILL BE QUITE ISOLATED IN NATURE. POST
FRONTAL NORTHEAST WINDS WILL SHIFT MORE EASTERLY THIS AFTERNOON. ANY
CONVECTION WILL FORM INLAND FROM THE COASTAL TERMINALS.
EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE OVER THE WEEKEND DUE TO
DIURNALLY DRIVEN CONVECTION. OTHERWISE EXPECT VFR THROUGHOUT THE
EXTENDED.
&&
.MARINE...
AS OF 945 AM THURSDAY...COLD FRONT WAS ANALYZED JUST SOUTH OF THE
SOUTH SANTEE RIVER AT 12Z. A GRADUAL SHIFT FROM NORTHEAST TO EAST
WINDS WILL OCCUR FROM NORTH TO SOUTH THROUGH THE AFTERNOON WITH
WIND SPEEDS REMAINING 10 KNOTS OR LESS. BUOY OBS INDICATE SEAS
AROUND 3 FT THIS MORNING AND LITTLE CHANGE IN WAVE HEIGHT IS
EXPECTED THROUGH TONIGHT. CHANCE FOR CONVECTION IS LOW OVER THE
WATERS...HOWEVER WIDELY SCATTERED SHOWERS AND TSTMS ARE POSSIBLE
ALONG THE SEA BREEZE. WITH A WEAK STEERING FLOW OUT OF THE NW TO N
THROUGH THE AFTERNOON...ANY SEA BREEZE DEVELOPMENT STANDS A CHANCE
OF DRIFTING OFF THE COAST.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM
THURSDAY...COLD FRONT WILL BE WELL SOUTH OF THE WATERS
FRIDAY...LEAVING NE WINDS IN ITS WAKE. SPEEDS WILL BE RELATIVELY
LIGHT HOWEVER...LESS THAN 10 KTS...AS NO SIGNIFICANT COOL SURGE IS
EXPECTED. THE GRADIENT WILL WEAKEN SLOWLY ON FRIDAY SUCH THAT
WINDS WILL BECOME LIGHT AND VARIABLE FRIDAY NIGHT INTO SATURDAY
BEFORE BERMUDA HIGH PRESSURE RETURNS WITH SW WINDS AROUND 10 KTS
DEVELOPING LATE IN THE PERIOD. THANKS TO THESE LIGHT WINDS AND
LACK OF ANY MEANINGFUL SWELL...SEAS WILL BE 2-3 FT THROUGH THE
PERIOD...ALTHOUGH THE PRIMARY WAVE GROUP WILL VARY SIGNIFICANTLY
WITH A NE WIND CHOP PREDOMINANT FRIDAY...BECOMING SOUTHERLY LATE.
LONG TERM /SUNDAY THROUGH MONDAY/
AS OF 300 AM THURSDAY...RETURN TO TYPICAL SUMMER CONDITIONS FOR THE
EXTENDED AS BERMUDA HIGH PRESSURE AND THE PIEDMONT TROUGH BECOME THE
DOMINANT INFLUENCES ON THE COASTAL WATERS. SW WINDS WILL BE THE RULE
THROUGH THE EXTENDED...WITH SPEEDS AROUND 10 KTS...BUT REACHING UP
TO 15 KTS IN THE EVENINGS AS THE GRADIENT PINCHES EAST OF THE
PIEDMONT TROUGH. SEAS WILL BE 2-4 FT WITH A SE GROUND SWELL AND SW
WIND WAVE THE PRIMARY GROUPS CREATING THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...CRM
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...REK/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
625 AM EDT THU JUL 16 2015
.SYNOPSIS...
COLD FRONT WILL CONTINUE TO PROGRESS OFF THE COAST AND STALL
OFFSHORE THIS MORNING. WEAK HIGH PRESSURE WILL BRING SEASONABLE
TEMPS AND MOSTLY DRY WEATHER THROUGH FRIDAY. AN UPPER RIDGE WILL
COMBINE WITH BERMUDA HIGH PRESSURE BEGINNING SATURDAY TO BRING A
RETURN OF HEAT AND HUMIDITY WITH AFTERNOON THUNDERSTORMS THROUGH
NEXT WEEK
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 605 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SURFACE OBS SHOW COLD FRONT IN PROCESS OF MOVING OFFSHORE EARLY
THIS MORNING. A CONSENSUS OF GUIDANCE HAS FRONT STALLING EAST AND
SOUTH OF THE FORECAST AREA LATER TODAY. THERE IS LITTLE IN THE WAY
OF COLD ADVECTION WITH THIS FEATURE ALTHOUGH THERE ARE SOME LOWER
DEWPOINT VALUES ADVECTING IN BEHIND THE FRONT. MAINLY IT WILL BE A
WIND SHIFT WITH THE FORECAST AREA EXPERIENCING LIGHT NE TO
EASTERLY WINDS TODAY AND TONIGHT. GIVEN THAT WE ARE EXPERIENCING
COLD FROPA...HOWEVER MODEST IT MAY BE...HAVE OPTED TO KEEP TODAYS
TEMPERATURES ON THE LOW SIDE OF GUIDANCE...LOWER THAN RECENTLY
EXPERIENCED AND RIGHT AROUND CLIMO.
CONVECTION WILL HAVE A TOUGH TIME GETTING GOING TODAY WITH AN UPPER
RIDGE BUILDING IN AND EXTENSIVE DRYING ALOFT. HOWEVER...MODEL
SOUNDINGS SHOW STEEP LOW LEVEL LAPSE RATES AND ADEQUATE LOW-LEVEL
MOISTURE ALONG WITH SOME MODEST INSTABILITY. SO...INTRODUCING SLIGHT
CHANCE POPS FOR MOST OF THE AREA FOR THIS AFTERNOON AND EVENING WITH
THE BEST CHANCES OVER OUR COASTAL COUNTIES. THESE COUNTIES WILL BE
CLOSEST IN VICINITY TO THE STALLED FRONT AND ALSO WILL BE UNDER THE
INFLUENCE OF A RESULTANT SEA BREEZE FRONT THAT LIKELY WILL REMAIN
PINNED NEAR THE COAST. EXPECT THAT ANY CONVECTION WILL BE MODEST AND
SHORT-LIVED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...ANOTHER GORGEOUS MID-JULY DAY EXPECTED
FRIDAY WITH SEASONABLE TEMPS AND RELATIVELY LOWERED HUMIDITY THANKS
TO DRY W/NW FLOW THROUGH MUCH OF THE COLUMN AND STILL COOL NE
SURFACE FLOW BEHIND WEDNESDAY NIGHTS COLD FRONT. SOUNDINGS SHOW
PWATS DOWN TO 1.5 INCHES OR LESS...WHICH COMBINED WITH SUBSIDENCE
BENEATH AN AMPLIFYING MID-LEVEL RIDGE WILL INHIBIT CONVECTION FRIDAY
WHILE PERMITTING AMPLE SUNSHINE. TEMPS FRIDAY WILL BE A DEGREE OR
TWO EITHER SIDE OF 90 FOR HIGHS...AND IN THE LOW 70S FOR MINS.
500MB RIDGE EXPANDS FROM THE ARKLATEX REGION SATURDAY...BULGING NE
INTO THE MID-ATLANTIC. THIS DRIVES INCREASING HEIGHTS
LOCALLY...WHICH COMBINE WITH SLOWLY RETURNING SW FLOW AROUND BERMUDA
HIGH PRESSURE TO CREATE A SIGNIFICANTLY WARMER AND MORE HUMID DAY
SATURDAY. THE RIDGING ALOFT WILL TEND TO SQUELCH MOST
CONVECTION...BUT SCHC POP IS NEEDED ALONG THE TYPICAL BOUNDARIES DUE
TO STRONG SURFACE HEATING CREATING A HIGHLY UNSTABLE COLUMN. DO NOT
EXPECTED MORE THAN ISOLATED COVERAGE DUE TO THE RIDGING ALOFT...BUT
A FEW STORMS ALONG THE SEA BREEZE AND PIEDMONT TROUGH ARE
POSSIBLE...WANING AFTER DARK IN THE USUAL FASHION. HIGHS SATURDAY
WILL BE ABOUT 3-5 DEGREES WARMER THAN FRIDAY...MID 90S WEST OF I-95
TO AROUND 90 AT THE COAST. LOWS WILL AGAIN DROP INTO THE LOW
70S...MID 70S AT THE BEACHES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...RIDGING CENTERED OVER THE NW GULF COAST
REGION WILL EXPAND ACROSS MOST OF THE SOUTHERN TIER THIS COMING
WEEK...WITH A SLIGHTLY SW TO NE RIDGE AXIS CREATING ABOVE NORMAL
TEMPS LOCALLY. AS THE RIDGE CENTER REMAINS WEST OF THE
CAROLINAS...MID-LEVEL FLOW WILL BE GENERALLY W/NW THROUGH WEDNESDAY
SO WEAK IMPULSES EMBEDDED WITHIN THE FLOW WILL HELP SPAWN CONVECTION
EACH AFTN/EVE...BUT NO SIGNIFICANT FORCING APPEARS ON THE HORIZON
AND ONLY TYPICAL SUMMERTIME ACTIVITY IS EXPECTED. WITH HEIGHTS
BULGING ALOFT TEMPS WILL BE WELL ABOVE NORMAL MOST OF NEXT WEEK WITH
WIDESPREAD MID-90S EACH AFTN AWAY FROM THE COAST...AND LOWS IN THE
MID 70S. A TROUGH/COLD FRONT WILL APPROACH AT THE TAIL END OF THE
PERIOD BUT ANY IMPACTS LOOK TO HOLD OFF UNTIL BEYOND THE EXTENDED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...ANY PATCHY MVFR FOG WILL QUICKLY MIX OUT WITHIN THE
HOUR. FRONTAL BOUNDARY SOUTH OF THE REGION WILL LIKELY STAY THERE
WHILE IT SLOWLY WEAKENS. THE HRRR MODEL SHOWS SEA BREEZE ACTIVITY
THIS AFTERNOON. THINK IT WILL BE QUITE ISOLATED IN NATURE. POST
FRONTAL NORTHEAST WINDS WILL SHIFT MORE EASTERLY THIS AFTERNOON. ANY
CONVECTION WILL FORM INLAND FROM THE COASTAL TERMINALS.
EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE OVER THE WEEKEND DUE TO
DIURNALLY DRIVEN CONVECTION. OTHERWISE EXPECT VFR THROUGHOUT THE
EXTENDED.
&&
.MARINE...
AS OF 605 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
COLD FRONT IN PROCESS OF MOVING OFFSHORE AND SHOULD BE EAST AND
SOUTH OF THE WATERS BY DAYBREAK. AS THERE IS NO REAL COLD SURGE
FOLLOWING FROPA AND GRADIENT WILL REMAIN SLACK EXPECT THAT WINDS
WILL BE LIGHT THROUGH THE NEAR TERM...TURNING NORTH LATER THIS
MORNING AND EASTERLY THIS AFTERNOON AND OVERNIGHT. SEAS WILL
SETTLE IN THE 2 TO 3 FT RANGE BY LATE THIS MORNING.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...COLD FRONT WILL BE WELL SOUTH OF THE WATERS
FRIDAY...LEAVING NE WINDS IN ITS WAKE. SPEEDS WILL BE RELATIVELY
LIGHT HOWEVER...LESS THAN 10 KTS...AS NO SIGNIFICANT COOL SURGE IS
EXPECTED. THE GRADIENT WILL WEAKEN SLOWLY ON FRIDAY SUCH THAT WINDS
WILL BECOME LIGHT AND VARIABLE FRIDAY NIGHT INTO SATURDAY BEFORE
BERMUDA HIGH PRESSURE RETURNS WITH SW WINDS AROUND 10 KTS DEVELOPING
LATE IN THE PERIOD. THANKS TO THESE LIGHT WINDS AND LACK OF ANY
MEANINGFUL SWELL...SEAS WILL BE 2-3 FT THROUGH THE PERIOD...ALTHOUGH
THE PRIMARY WAVE GROUP WILL VARY SIGNIFICANTLY WITH A NE WIND CHOP
PREDOMINANT FRIDAY...BECOMING SOUTHERLY LATE.
LONG TERM /SUNDAY THROUGH MONDAY/
AS OF 300 AM THURSDAY...RETURN TO TYPICAL SUMMER CONDITIONS FOR THE
EXTENDED AS BERMUDA HIGH PRESSURE AND THE PIEDMONT TROUGH BECOME THE
DOMINANT INFLUENCES ON THE COASTAL WATERS. SW WINDS WILL BE THE RULE
THROUGH THE EXTENDED...WITH SPEEDS AROUND 10 KTS...BUT REACHING UP
TO 15 KTS IN THE EVENINGS AS THE GRADIENT PINCHES EAST OF THE
PIEDMONT TROUGH. SEAS WILL BE 2-4 FT WITH A SE GROUND SWELL AND SW
WIND WAVE THE PRIMARY GROUPS CREATING THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...43
MARINE...REK/JDW
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
246 PM CDT THU JUL 16 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 245 PM CDT THU JUL 16 2015
THE MAIN CHALLENGE WILL BE CONVECTIVE/SEVERE CHANCES THROUGH
FRIDAY. THE CAM MODELS ARE IN PRETTY GOOD AGREEMENT...AND THE
CONSISTENT HRRR HAS A GOOD HANDLE ON THINGS THROUGH THIS EVENING.
WILL LEAN ON THE GFS THEREAFTER WITH BETTER SHEAR AROUND FRI
AFTERNOON/EVENING.
FOR LATE THIS AFTERNOON AND TONIGHT...A STRONG SHORTWAVE WILL MOVE
FROM WEST TO EAST. THERE WILL BE MLCAPES AROUND 1500 J/KG IN THE
SOUTH AND 500-1000J/KG NORTH. MID LEVEL LAPSE RATES ARE NOT TOO
STEEP IN THE NORTH...AND A BIT BETTER SOUTH. THERE HAS ALSO BEEN
PLENTY OF CLOUDS/PRECIP THAT HAS HINDERED WARMING WITH CONVECTIVE
TEMPS AROUND 80. THERE COULD BE A WINDOW WHERE AREAS HEAT OUT
SOME THIS AFTERNOON...AND THERE IS STILL A MARGINAL RISK FOR
SEVERE STORMS WITH THE BEST THREAT IN THE SOUTH CLOSER TO SLIGHTLY
BETTER SHEAR/INSTABILITY.
ON FRIDAY...A SPEED MAX WILL APPROACH FROM THE WEST WITH AMPLE
INSTABILITY OVERSPREADING THE AREA. A SFC LOW WILL TRACK NEAR THE
ND/SD BORDER AROUND 00Z...AND THE POTENTIAL FOR SOME MORE SEVERE
WEATHER IS POSSIBLE. SPC HAS A SLIGHT RISK NEAR THE SOUTH FA AND
MARGINAL RISK TO THE NORTH. THERE SHOULD BE MORE HEATING ON FRIDAY
AHEAD OF THE NEXT SHORTWAVE...ALONG WITH MORE SHEAR...SO POTENTIAL
FOR MORE WIDEPSREAD SEVERE CLOSE OR INTO THE FA ON FRIDAY
AFTERNOON INTO THE OVERNIGHT POSSIBLE. THERE IS A 45-50KT LLJ
FRIDAY NIGHT INTO THE MN COUNTIES...SO SEVERE THREAT COULD PERSIST
THROUGH MUCH OF THE NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 245 PM CDT THU JUL 16 2015
ON SATURDAY...MORNING CONVECTION SHOULD QUICKLY MOVE INTO THE
NORTH AND EAST BY AFTERNOON BEHIND A COLD FRONT. MUCH OF THE
REGION WILL BE DRY SAT AFTERNOON WITH COOLER AIR ALOFT AND TEMPS
IN THE MID/UPPER 70S NORTH TO AROUND 80 SOUTH. IT COULD GET A BIT
BREEZY FROM THE W/NW SAT AFTERNOON WITH PWATS FALLING BELOW 1
INCH.
FOR SUNDAY...IT SHOULD BE DRY WITH TEMPS A BIT WARMER THAN SAT.
WESTERLY FLOW SHOULD PERSIST ALONG WITH PLENTY OF SUNSHINE.
FOR SUN THROUGH THU...HIGH PRESSURE WILL GIVE GENERALLY DRY
CONDITIONS SUN NIGHT INTO MONDAY. A WEAK FRONT WILL DROP SOUTH
THROUGH NRN MINNESOTA LATE MONDAY AND MONDAY EVE GIVING A LOW
RISK OF T-STORMS MAINLY EAST OF THE RED RIVER. MAINLY DRY AGAIN
TUESDAY. NEXT SHORT WAVE OF ANY SIGNIFICANCE IS DUE WED WITH BEST
CHANCES FOR T-STORMS AT THAT TIME. TEMPS TO RUN CLOSE TO NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1220 PM CDT THU JUL 16 2015
LINGERING LOW END MVFR CIGS PRESENT FROM THIS MORNING
SHOULD BREAK UP THIS AFTERNOON IN NW MN GIVING WAY TO A VFR MOSTLY
MID CLOUD DECK. AREA OF RAIN AND T-STORMS MOVING NORTHEAST THRU
NCNTRL MN AFFECTING TVF/BJI TAF SITES THRU 20Z OR SO. ADDITIONAL
CONVECTION FOR THIS LATE AFTN-EARLY EVE IS QUESTIONABLE IN TERMS OF
COVERAGE AND INTENSITY SO KEPT VCTS IN MOST SITES EXCEPT DVL WHICH
SHOULD SEE A WIND SHIFT MID AFTN TO THE WEST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...DK
LONG TERM...DK/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1244 PM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 1220 PM CDT THU JUL 16 2015
NO CHANGES NEEDED...WITH THE MARGINAL RISK FOR SEVERE STORMS THIS
AFTERNOON AND EVENING STILL FORECAST.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
WIDESPREAD DEEP CONVECTION IS OCCURRING ACROSS NORTHEASTERN
ND...EXTENDING BACK INTO CENTRAL AND SOUTHERN ND...AHEAD OF A WEAK
MID LEVEL /H7-H5/ TROF. MUCAPE VALUES OF 500-1000 J/KG NOW ACROSS
ERN ND WILL SLOWLY TRANSLATE EWD AND INCREASE THROUGH THE
DAY...SUPPORTING CONTINUED DEEP CONVECTION ACROSS THE RRV AND
INTO NORTHERN MN THROUGHOUT THE FORENOON AND INTO THE AFTERNOON
AND EARLY EVENING.
PATCHY SUNSHINE AND ASSOCIATED SURFACE HEATING IS MOST LIKELY
ACROSS THE SOUTHERN RED RIVER BASIN...AND WILL PROVIDE SOME
INTENSIFICATION OF A WEAK SURFACE TROF THERE AND FOCUS FOR
STRONGER STORMS TO DEVELOP THROUGH THE AFTERNOON. NAM12 AND RAP13
BOTH SHOW UPWARDS OF 1000 J/KG OF CAPE IN THE 0-2KM FROM 18-21Z
THIS AFTERNOON ACROSS SERN ND...WITH HIGH VALUES TRANSLATING INTO
WCNTRL MN FROM LATE AFTERNOON INTO EARLY EVENING. HRRR AND NSSL
CAMS SHOW THE POSSIBILITY FOR SOME DISTINCTLY STRONGER CELLS IN
THE SOUTHERN RRV /19-22Z/ ...CONSISTENT WITH SPC DY1 CONVECTIVE
OUTLOOK AND MARGINAL RISK FOR SEVERE WEATHER THERE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
FRIDAY NIGHT THROUGH SATURDAY...UPPER LEVEL SHORTWAVE TROF SWINGS
FROM EAST FLANK OF THE CANADIAN ROCKIES AND ACROSS THE NORTHERN
PLAINS THROUGH THE PERIOD SO WIDEPSREAD WETTING RAINS AND THUNDER
ARE TO BE EXPECTED...MAINLY FRIDAY EVENING INTO EARLY SATURDAY.
SURFACE TROF AXIS ACROSS THE SOUTHERN FA COULD PROVIDE A FOCUS
FOR SOME STRONGER STORMS THERE. SPC CONVECTIVE OUTLOOK AGAIN
MAINTAINS A MARGINAL TO SLIGHT RISK FOR SEVERE THUNDERSTORMS
ACROSS THE FAR SOUTHERN EDGE OF THE FA FROM DY2 INTO DY3.
SUNDAY THROUGH WEDNESDAY... MODELS IN GOOD AGREEMENT WITH
POSITIONING OF UPPER LEVEL FEATURES AS THE PATTERN BECOMES A
LITTLE MORE UNSETTLED. OTHERWISE...A LOW PRESSURE SYSTEM IS
EXPECTED TO CROSS THE NRN PLAINS ON MONDAY BRINGING SHOWERS AND
THUNDERSTORMS AHEAD OF IT...WITH A BIT COOLER AND DRIER AIR BEHIND
IT AS THE ASSOCIATED UPPER TROF MOVES THROUGH. LOOK FOR SFC HIGH
PRESSURE TO SHIFT OVER THE AREA BEHIND THE SYSTEM BRINGING MORE
TRANQUIL CONDITIONS THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1220 PM CDT THU JUL 16 2015
LINGERING LOW END MVFR CIGS PRESENT FROM THIS MORNING
SHOULD BREAK UP THIS AFTERNOON IN NW MN GIVING WAY TO A VFR MOSTLY
MID CLOUD DECK. AREA OF RAIN AND T-STORMS MOVING NORTHEAST THRU
NCNTRL MN AFFECTING TVF/BJI TAF SITES THRU 20Z OR SO. ADDITIONAL
CONVECTION FOR THIS LATE AFTN-EARLY EVE IS QUESTIONABLE IN TERMS OF
COVERAGE AND INTENSITY SO KEPT VCTS IN MOST SITES EXCEPT DVL WHICH
SHOULD SEE A WIND SHIFT MID AFTN TO THE WEST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...GUST
LONG TERM...GUST/HOPKINS
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1239 PM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 1232 PM CDT THU JUL 16 2015
THUNDERSTORMS CONTINUE TO DEVELOP OVER PORTIONS OF SOUTH CENTRAL
NORTH DAKOTA INTO THE JAMES RIVER VALLEY. EXPECT THIS TREND TO
CONTINUE THROUGH THE AFTERNOON AS A SHORT WAVE PUSHES INTO THE
AREA. LATEST MODEL GUIDANCE STILL SUGGESTS THIS AREA TO HAVE THE
GREATEST INSTABILITY...THUS A POTENTIAL SEVERE THREAT.
UPDATE ISSUED AT 844 AM CDT THU JUL 16 2015
BROAD AREA OF THUNDERSTORMS CONTINUES TO PUSH INTO EASTERN NORTH
DAKOTA WHILE THE NEXT SHORT WAVE PUSHES THROUGH EASTERN MONTANA
INTO FAR WESTERN NORTH DAKOTA. LATEST HIGH-RES MODELS SHOW
CONVECTION RE-DEVELOPING IN THE EARLY AFTERNOON OVER PORTIONS OF
CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY. GREATEST
INSTABILITY REMAINS OVER PORTIONS OF THE JAMES RIVER VALLEY BUT
THEN WORKS EAST SO THERE MAY BE A BRIEF SEVERE THREAT THIS
AFTERNOON.
UPDATE ISSUED AT 633 AM CDT THU JUL 16 2015
QUICK UPDATE TO BLEND RADAR TRENDS THROUGH 1130 UTC TO THE TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS THROUGH THE
AFTERNOON. THE RESULT IS TO CONFINE POPS THE REMAINDER OF THE DAY
GENERALLY TO ALONG AND EAST OF HIGHWAY 83 AS SUBSIDENCE INCREASES
WEST IN THE WAKE OF THE SHORTWAVE TROUGH CURRENTLY CENTERED ON THE
NORTH DAKOTA AND MONTANA BORDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 200 AM CDT THU JUL 16 2015
FOCUS IN THE SHORT TERM IS ON THE THUNDERSTORMS OVER THE AREA
EARLY THIS MORNING AND HOW QUICKLY THUNDERSTORMS WILL PUSH EAST OF
THE AREA.
REFLECTIVITY AS OF 07 UTC WAS SHOWING PRECIPITATION RAPIDLY
DIMINISHING ACROSS THE NORTH WITH A FEW STORMS AMPLIFYING ACROSS
THE SOUTH. MESO-ANALYSIS SUGGESTS THAT SOUTHERN STORMS ARE TAPPING
INTO THE GREATER AMOUNTS OF CAPE AVAILABLE IN THE REGION ALONG
WITH A THIN BAND OF 850 MB MOISTURE TRANSPORT FLOWING NORTH ALONG
AND EAST OF THE MISSOURI RIVER. THE STORM JUST SOUTH OF BISMARCK
IS PRODUCING SOME HEAVY RAINFALL AMOUNTS WARRANTING A FLOOD
ADVISORY. WHILE A FEW STORMS THIS MORNING MAY PRODUCE HEAVY
RAIN...SMALL HAIL AND SOME GUSTY WINDS...DO NOT SEE ANY REACHING
SEVERE LIMITS AT THIS TIME. DEEP LAYER SHEAR IS STILL LACKING IN
THE AREA AND EXPECT THESE STORMS TO BE SLOW MOVING AND RELATIVELY
SHORT LIVED.
AS FOR THUNDERSTORMS EXITING CENTRAL AND WESTERN NORTH DAKOTA
TODAY THE NAM...ECMWF..AND GFS 00 UTC RUNS HAVE COME INTO BETTER
AGREEMENT. AT THIS TIME THE MODELS HAVE THE UPPER LEVEL SHORTWAVE
CENTERED OVER THE DAKOTA MINNESOTA BORDER BY 00 UTC FRIDAY. WHILE
THIS ROUND OF THUNDERSTORMS IS EXPECTED TO PUSH EAST OF THE JAMES
RIVER VALLEY BY 00 UTC FRIDAY ANOTHER ROUND OF THUNDERSTORMS WILL
IMPACT WESTERN NORTH DAKOTA LATE THURSDAY NIGHT FROM A DEEPENING
TROUGH OVER THE ROCKIES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 200 AM CDT THU JUL 16 2015
A TRANSITION TO A LESS ACTIVE THUNDERSTORM PATTERN HIGHLIGHTS THE
EXTENDED FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON ONE MORE ROUND OF THUNDERSTORMS ACROSS MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA FRIDAY MORNING AND INTO THE
EARLY AFTERNOON AHEAD OF THE FIRST OF TWO COLD FRONTS. ML CAPE
AND SHEAR PROFILES SUGGEST A FEW STORMS COULD BE STRONG TO SEVERE
ACROSS CENTRAL NORTH DAKOTA FRIDAY...AND THIS POTENTIAL WILL HAVE
TO BE MONITORED. THEREAFTER....A DRY SLOT ASSOCIATED WITH A
DEEPENING CLOSED LOW ACROSS SASKATCHEWAN IS FORECAST TO OVERTAKE
MUCH OF THE STATE FRIDAY NIGHT INTO SATURDAY...WITH THE ARRIVAL OF
THE SECONDARY REINFORCING COLD FRONT ON SATURDAY. AT THIS
TIME...FOCUSED THUNDERSTORM CHANCES NEAR THE INTERNATIONAL BORDER
IN ASSOCIATION WITH THE AFOREMENTIONED LOW. INTO NEXT WEEK UNDER
NORTHWEST FLOW ALOFT...RELATIVELY COOLER AND DRIER WEATHER
COMPARED TO THE PAST SEVERAL DAYS IS EXPECTED TO PREVAIL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM CDT THU JUL 16 2015
LCL MVFR CIGS WILL CONTINUE INTO EARLY AFTERNOON OVER PORTIONS OF
SOUTH CENTRAL NORTH DAKOTA BEFORE IMPROVING. THUNDERSTORMS WILL
CONTINUE TO DEVELOP OVER FAR CENTRAL INTO EASTERN NORTH DAKOTA
THIS AFTERNOON...PUSHING EAST BY EVENING. ANOTHER DISTURBANCE
APPROACHES LATE TONIGHT...BRINGING THUNDERSTORM CHANCES EARLY
FRIDAY MORNING TO WESTERN NORTH DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...AYD
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
941 AM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 939 AM CDT THU JUL 16 2015
NO MAJOR CHANGES NEEDED THIS MORNING. SEVERE STORMS WILL HINGE ON
HOW MUCH SUNSHINE WE GET...AND THERE ARE PLENTY OF CLOUDS AROUND
AND PRECIP...SO HEATING HAS BEEN LIMITED THUS FAR. THE MAIN SEVERE
POTENTIAL COULD BE LATE THIS AFTERNOON OR EVEN THIS EVENING INTO
TONIGHT ONCE STRONGER SHORTWAVE MOVES THROUGH.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
WIDESPREAD DEEP CONVECTION IS OCCURRING ACROSS NORTHEASTERN
ND...EXTENDING BACK INTO CENTRAL AND SOUTHERN ND...AHEAD OF A WEAK
MID LEVEL /H7-H5/ TROF. MUCAPE VALUES OF 500-1000 J/KG NOW ACROSS
ERN ND WILL SLOWLY TRANSLATE EWD AND INCREASE THROUGH THE
DAY...SUPPORTING CONTINUED DEEP CONVECTION ACROSS THE RRV AND
INTO NORTHERN MN THROUGHOUT THE FORENOON AND INTO THE AFTERNOON
AND EARLY EVENING.
PATCHY SUNSHINE AND ASSOCIATED SURFACE HEATING IS MOST LIKELY
ACROSS THE SOUTHERN RED RIVER BASIN...AND WILL PROVIDE SOME
INTENSIFICATION OF A WEAK SURFACE TROF THERE AND FOCUS FOR
STRONGER STORMS TO DEVELOP THROUGH THE AFTERNOON. NAM12 AND RAP13
BOTH SHOW UPWARDS OF 1000 J/KG OF CAPE IN THE 0-2KM FROM 18-21Z
THIS AFTERNOON ACROSS SERN ND...WITH HIGH VALUES TRANSLATING INTO
WCNTRL MN FROM LATE AFTERNOON INTO EARLY EVENING. HRRR AND NSSL
CAMS SHOW THE POSSIBILITY FOR SOME DISTINCTLY STRONGER CELLS IN
THE SOUTHERN RRV /19-22Z/ ...CONSISTENT WITH SPC DY1 CONVECTIVE
OUTLOOK AND MARGINAL RISK FOR SEVERE WEATHER THERE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
FRIDAY NIGHT THROUGH SATURDAY...UPPER LEVEL SHORTWAVE TROF SWINGS
FROM EAST FLANK OF THE CANADIAN ROCKIES AND ACROSS THE NORTHERN
PLAINS THROUGH THE PERIOD SO WIDEPSREAD WETTING RAINS AND THUNDER
ARE TO BE EXPECTED...MAINLY FRIDAY EVENING INTO EARLY SATURDAY.
SURFACE TROF AXIS ACROSS THE SOUTHERN FA COULD PROVIDE A FOCUS
FOR SOME STRONGER STORMS THERE. SPC CONVECTIVE OUTLOOK AGAIN
MAINTAINS A MARGINAL TO SLIGHT RISK FOR SEVERE THUNDERSTORMS
ACROSS THE FAR SOUTHERN EDGE OF THE FA FROM DY2 INTO DY3.
SUNDAY THROUGH WEDNESDAY... MODELS IN GOOD AGREEMENT WITH
POSITIONING OF UPPER LEVEL FEATURES AS THE PATTERN BECOMES A
LITTLE MORE UNSETTLED. OTHERWISE...A LOW PRESSURE SYSTEM IS
EXPECTED TO CROSS THE NRN PLAINS ON MONDAY BRINGING SHOWERS AND
THUNDERSTORMS AHEAD OF IT...WITH A BIT COOLER AND DRIER AIR BEHIND
IT AS THE ASSOCIATED UPPER TROF MOVES THROUGH. LOOK FOR SFC HIGH
PRESSURE TO SHIFT OVER THE AREA BEHIND THE SYSTEM BRINGING MORE
TRANQUIL CONDITIONS THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 640 AM CDT THU JUL 16 2015
MAINLY VFR CONDITIONS EXPECTED WITH CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THIS EVENING. WINDS WILL BE FROM A SOUTHERLY
DIRECTION FOR MUCH OF TODAY...WITH A WESTERLY WIND SHIFT MOVING
INTO THE DEVILS LAKE AREA BY THIS AFTERNOON SPREADING EAST
OVERNIGHT. MORE ORGANIZED STORMS ARE POSSIBLE THIS AFTERNOON
THROUGHOUT THE REGION...WITH GUSTY WINDS ALSO POSSIBLE NEAR
STRONGER STORMS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...GUST
LONG TERM...GUST/HOPKINS
AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
938 AM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 844 AM CDT THU JUL 16 2015
BROAD AREA OF THUNDERSTORMS CONTINUES TO PUSH INTO EASTERN NORTH
DAKOTA WHILE THE NEXT SHORT WAVE PUSHES THROUGH EASTERN MONTANA
INTO FAR WESTERN NORTH DAKOTA. LATEST HIGH-RES MODELS SHOW
CONVECTION RE-DEVELOPING IN THE EARLY AFTERNOON OVER PORTIONS OF
CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY. GREATEST
INSTABILITY REMAINS OVER PORTIONS OF THE JAMES RIVER VALLEY BUT
THEN WORKS EAST SO THERE MAY BE A BRIEF SEVERE THREAT THIS
AFTERNOON.
UPDATE ISSUED AT 633 AM CDT THU JUL 16 2015
QUICK UPDATE TO BLEND RADAR TRENDS THROUGH 1130 UTC TO THE TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS THROUGH THE
AFTERNOON. THE RESULT IS TO CONFINE POPS THE REMAINDER OF THE DAY
GENERALLY TO ALONG AND EAST OF HIGHWAY 83 AS SUBSIDENCE INCREASES
WEST IN THE WAKE OF THE SHORTWAVE TROUGH CURRENTLY CENTERED ON THE
NORTH DAKOTA AND MONTANA BORDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 200 AM CDT THU JUL 16 2015
FOCUS IN THE SHORT TERM IS ON THE THUNDERSTORMS OVER THE AREA
EARLY THIS MORNING AND HOW QUICKLY THUNDERSTORMS WILL PUSH EAST OF
THE AREA.
REFLECTIVITY AS OF 07 UTC WAS SHOWING PRECIPITATION RAPIDLY
DIMINISHING ACROSS THE NORTH WITH A FEW STORMS AMPLIFYING ACROSS
THE SOUTH. MESO-ANALYSIS SUGGESTS THAT SOUTHERN STORMS ARE TAPPING
INTO THE GREATER AMOUNTS OF CAPE AVAILABLE IN THE REGION ALONG
WITH A THIN BAND OF 850 MB MOISTURE TRANSPORT FLOWING NORTH ALONG
AND EAST OF THE MISSOURI RIVER. THE STORM JUST SOUTH OF BISMARCK
IS PRODUCING SOME HEAVY RAINFALL AMOUNTS WARRANTING A FLOOD
ADVISORY. WHILE A FEW STORMS THIS MORNING MAY PRODUCE HEAVY
RAIN...SMALL HAIL AND SOME GUSTY WINDS...DO NOT SEE ANY REACHING
SEVERE LIMITS AT THIS TIME. DEEP LAYER SHEAR IS STILL LACKING IN
THE AREA AND EXPECT THESE STORMS TO BE SLOW MOVING AND RELATIVELY
SHORT LIVED.
AS FOR THUNDERSTORMS EXITING CENTRAL AND WESTERN NORTH DAKOTA
TODAY THE NAM...ECMWF..AND GFS 00 UTC RUNS HAVE COME INTO BETTER
AGREEMENT. AT THIS TIME THE MODELS HAVE THE UPPER LEVEL SHORTWAVE
CENTERED OVER THE DAKOTA MINNESOTA BORDER BY 00 UTC FRIDAY. WHILE
THIS ROUND OF THUNDERSTORMS IS EXPECTED TO PUSH EAST OF THE JAMES
RIVER VALLEY BY 00 UTC FRIDAY ANOTHER ROUND OF THUNDERSTORMS WILL
IMPACT WESTERN NORTH DAKOTA LATE THURSDAY NIGHT FROM A DEEPENING
TROUGH OVER THE ROCKIES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 200 AM CDT THU JUL 16 2015
A TRANSITION TO A LESS ACTIVE THUNDERSTORM PATTERN HIGHLIGHTS THE
EXTENDED FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON ONE MORE ROUND OF THUNDERSTORMS ACROSS MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA FRIDAY MORNING AND INTO THE
EARLY AFTERNOON AHEAD OF THE FIRST OF TWO COLD FRONTS. ML CAPE
AND SHEAR PROFILES SUGGEST A FEW STORMS COULD BE STRONG TO SEVERE
ACROSS CENTRAL NORTH DAKOTA FRIDAY...AND THIS POTENTIAL WILL HAVE
TO BE MONITORED. THEREAFTER....A DRY SLOT ASSOCIATED WITH A
DEEPENING CLOSED LOW ACROSS SASKATCHEWAN IS FORECAST TO OVERTAKE
MUCH OF THE STATE FRIDAY NIGHT INTO SATURDAY...WITH THE ARRIVAL OF
THE SECONDARY REINFORCING COLD FRONT ON SATURDAY. AT THIS
TIME...FOCUSED THUNDERSTORM CHANCES NEAR THE INTERNATIONAL BORDER
IN ASSOCIATION WITH THE AFOREMENTIONED LOW. INTO NEXT WEEK UNDER
NORTHWEST FLOW ALOFT...RELATIVELY COOLER AND DRIER WEATHER
COMPARED TO THE PAST SEVERAL DAYS IS EXPECTED TO PREVAIL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 633 AM CDT THU JUL 16 2015
AN AREA OF SHOWERS AND THUNDERSTORMS REMAIN ACROSS SOUTH CENTRAL
NORTH DAKOTA THIS MORNING. THROUGH THE MORNING THIS AREA OF
SHOWERS AND THUNDERSTORMS WILL MOVE EAST AND IMPACT KJMS...AND
REDEVELOPMENT ON THE BACK EDGE COULD IMPACT KBIS. OTHERWISE
THUNDERSTORMS WILL BE SCATTERED FOR THE REMAINDER OF THE DAY
ACROSS CENTRAL NORTH DAKOTA. LOW CLOUDS AND SOME FOG HAVE
DEVELOPED BEHIND THE SHOWERS THIS MORNING. COVERAGE AT THIS TIME
IS SCATTERED...HOWEVER...AT TIMES CONDITIONS COULD DROP TO IFR OR
EVEN LIFR THROUGH THE EARLY MORNING. CONDITIONS WILL IMPROVE LATER
IN THE MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
641 AM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 640 AM CDT THU JUL 16 2015
NO MAJOR CHANGES NEEDED FOR THIS UPDATE. AN AREA OF SHOWERS
ORIENTED FROM SW TO NE INTO NORTHEAST ND CONTINUES TO SLOWLY
DISSIPATE. THERE IS A STRONGER SHORTWAVE EVIDENT ON WATER VAPOR
MOVING INTO SW ND THIS MORNING. EXPECT THIS TO AID MORE STORMS
THIS AFTERNOON...SOME SEVERE WITH A MARGINAL RISK IN PLACE FOR THE
ENTIRE REGION.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
WIDESPREAD DEEP CONVECTION IS OCCURRING ACROSS NORTHEASTERN
ND...EXTENDING BACK INTO CENTRAL AND SOUTHERN ND...AHEAD OF A WEAK
MID LEVEL /H7-H5/ TROF. MUCAPE VALUES OF 500-1000 J/KG NOW ACROSS
ERN ND WILL SLOWLY TRANSLATE EWD AND INCREASE THROUGH THE
DAY...SUPPORTING CONTINUED DEEP CONVECTION ACROSS THE RRV AND
INTO NORTHERN MN THROUGHOUT THE FORENOON AND INTO THE AFTERNOON
AND EARLY EVENING.
PATCHY SUNSHINE AND ASSOCIATED SURFACE HEATING IS MOST LIKELY
ACROSS THE SOUTHERN RED RIVER BASIN...AND WILL PROVIDE SOME
INTENSIFICATION OF A WEAK SURFACE TROF THERE AND FOCUS FOR
STRONGER STORMS TO DEVELOP THROUGH THE AFTERNOON. NAM12 AND RAP13
BOTH SHOW UPWARDS OF 1000 J/KG OF CAPE IN THE 0-2KM FROM 18-21Z
THIS AFTERNOON ACROSS SERN ND...WITH HIGH VALUES TRANSLATING INTO
WCNTRL MN FROM LATE AFTERNOON INTO EARLY EVENING. HRRR AND NSSL
CAMS SHOW THE POSSIBILITY FOR SOME DISTINCTLY STRONGER CELLS IN
THE SOUTHERN RRV /19-22Z/ ...CONSISTENT WITH SPC DY1 CONVECTIVE
OUTLOOK AND MARGINAL RISK FOR SEVERE WEATHER THERE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
FRIDAY NIGHT THROUGH SATURDAY...UPPER LEVEL SHORTWAVE TROF SWINGS
FROM EAST FLANK OF THE CANADIAN ROCKIES AND ACROSS THE NORTHERN
PLAINS THROUGH THE PERIOD SO WIDEPSREAD WETTING RAINS AND THUNDER
ARE TO BE EXPECTED...MAINLY FRIDAY EVENING INTO EARLY SATURDAY.
SURFACE TROF AXIS ACROSS THE SOUTHERN FA COULD PROVIDE A FOCUS
FOR SOME STRONGER STORMS THERE. SPC CONVECTIVE OUTLOOK AGAIN
MAINTAINS A MARGINAL TO SLIGHT RISK FOR SEVERE THUNDERSTORMS
ACROSS THE FAR SOUTHERN EDGE OF THE FA FROM DY2 INTO DY3.
SUNDAY THROUGH WEDNESDAY... MODELS IN GOOD AGREEMENT WITH
POSITIONING OF UPPER LEVEL FEATURES AS THE PATTERN BECOMES A
LITTLE MORE UNSETTLED. OTHERWISE...A LOW PRESSURE SYSTEM IS
EXPECTED TO CROSS THE NRN PLAINS ON MONDAY BRINGING SHOWERS AND
THUNDERSTORMS AHEAD OF IT...WITH A BIT COOLER AND DRIER AIR BEHIND
IT AS THE ASSOCIATED UPPER TROF MOVES THROUGH. LOOK FOR SFC HIGH
PRESSURE TO SHIFT OVER THE AREA BEHIND THE SYSTEM BRINGING MORE
TRANQUIL CONDITIONS THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 640 AM CDT THU JUL 16 2015
MAINLY VFR CONDITIONS EXPECTED WITH CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THIS EVENING. WINDS WILL BE FROM A SOUTHERLY
DIRECTION FOR MUCH OF TODAY...WITH A WESTERLY WIND SHIFT MOVING
INTO THE DEVILS LAKE AREA BY THIS AFTERNOON SPREADING EAST
OVERNIGHT. MORE ORGANIZED STORMS ARE POSSIBLE THIS AFTERNOON
THROUGHOUT THE REGION...WITH GUSTY WINDS ALSO POSSIBLE NEAR
STRONGER STORMS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...GUST
LONG TERM...GUST/HOPKINS
AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
639 AM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 633 AM CDT THU JUL 16 2015
QUICK UPDATE TO BLEND RADAR TRENDS THROUGH 1130 UTC TO THE TIME
LAGGED ENSEMBLE OF THE 08-10 UTC HRRR ITERATIONS THROUGH THE
AFTERNOON. THE RESULT IS TO CONFINE POPS THE REMAINDER OF THE DAY
GENERALLY TO ALONG AND EAST OF HIGHWAY 83 AS SUBSIDENCE INCREASES
WEST IN THE WAKE OF THE SHORTWAVE TROUGH CURRENTLY CENTERED ON THE
NORTH DAKOTA AND MONTANA BORDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 200 AM CDT THU JUL 16 2015
FOCUS IN THE SHORT TERM IS ON THE THUNDERSTORMS OVER THE AREA
EARLY THIS MORNING AND HOW QUICKLY THUNDERSTORMS WILL PUSH EAST OF
THE AREA.
REFLECTIVITY AS OF 07 UTC WAS SHOWING PRECIPITATION RAPIDLY
DIMINISHING ACROSS THE NORTH WITH A FEW STORMS AMPLIFYING ACROSS
THE SOUTH. MESO-ANALYSIS SUGGESTS THAT SOUTHERN STORMS ARE TAPPING
INTO THE GREATER AMOUNTS OF CAPE AVAILABLE IN THE REGION ALONG
WITH A THIN BAND OF 850 MB MOISTURE TRANSPORT FLOWING NORTH ALONG
AND EAST OF THE MISSOURI RIVER. THE STORM JUST SOUTH OF BISMARCK
IS PRODUCING SOME HEAVY RAINFALL AMOUNTS WARRANTING A FLOOD
ADVISORY. WHILE A FEW STORMS THIS MORNING MAY PRODUCE HEAVY
RAIN...SMALL HAIL AND SOME GUSTY WINDS...DO NOT SEE ANY REACHING
SEVERE LIMITS AT THIS TIME. DEEP LAYER SHEAR IS STILL LACKING IN
THE AREA AND EXPECT THESE STORMS TO BE SLOW MOVING AND RELATIVELY
SHORT LIVED.
AS FOR THUNDERSTORMS EXITING CENTRAL AND WESTERN NORTH DAKOTA
TODAY THE NAM...ECMWF..AND GFS 00 UTC RUNS HAVE COME INTO BETTER
AGREEMENT. AT THIS TIME THE MODELS HAVE THE UPPER LEVEL SHORTWAVE
CENTERED OVER THE DAKOTA MINNESOTA BORDER BY 00 UTC FRIDAY. WHILE
THIS ROUND OF THUNDERSTORMS IS EXPECTED TO PUSH EAST OF THE JAMES
RIVER VALLEY BY 00 UTC FRIDAY ANOTHER ROUND OF THUNDERSTORMS WILL
IMPACT WESTERN NORTH DAKOTA LATE THURSDAY NIGHT FROM A DEEPENING
TROUGH OVER THE ROCKIES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 200 AM CDT THU JUL 16 2015
A TRANSITION TO A LESS ACTIVE THUNDERSTORM PATTERN HIGHLIGHTS THE
EXTENDED FORECAST.
THE 00 UTC GLOBAL DETERMINISTIC AND ENSEMBLE SUITES ARE IN
AGREEMENT ON ONE MORE ROUND OF THUNDERSTORMS ACROSS MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA FRIDAY MORNING AND INTO THE
EARLY AFTERNOON AHEAD OF THE FIRST OF TWO COLD FRONTS. ML CAPE
AND SHEAR PROFILES SUGGEST A FEW STORMS COULD BE STRONG TO SEVERE
ACROSS CENTRAL NORTH DAKOTA FRIDAY...AND THIS POTENTIAL WILL HAVE
TO BE MONITORED. THEREAFTER....A DRY SLOT ASSOCIATED WITH A
DEEPENING CLOSED LOW ACROSS SASKATCHEWAN IS FORECAST TO OVERTAKE
MUCH OF THE STATE FRIDAY NIGHT INTO SATURDAY...WITH THE ARRIVAL OF
THE SECONDARY REINFORCING COLD FRONT ON SATURDAY. AT THIS
TIME...FOCUSED THUNDERSTORM CHANCES NEAR THE INTERNATIONAL BORDER
IN ASSOCIATION WITH THE AFOREMENTIONED LOW. INTO NEXT WEEK UNDER
NORTHWEST FLOW ALOFT...RELATIVELY COOLER AND DRIER WEATHER
COMPARED TO THE PAST SEVERAL DAYS IS EXPECTED TO PREVAIL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 633 AM CDT THU JUL 16 2015
AN AREA OF SHOWERS AND THUNDERSTORMS REMAIN ACROSS SOUTH CENTRAL
NORTH DAKOTA THIS MORNING. THROUGH THE MORNING THIS AREA OF
SHOWERS AND THUNDERSTORMS WILL MOVE EAST AND IMPACT KJMS...AND
REDEVELOPMENT ON THE BACK EDGE COULD IMPACT KBIS. OTHERWISE
THUNDERSTORMS WILL BE SCATTERED FOR THE REMAINDER OF THE DAY
ACROSS CENTRAL NORTH DAKOTA. LOW CLOUDS AND SOME FOG HAVE
DEVELOPED BEHIND THE SHOWERS THIS MORNING. COVERAGE AT THIS TIME
IS SCATTERED...HOWEVER...AT TIMES CONDITIONS COULD DROP TO IFR OR
EVEN LIFR THROUGH THE EARLY MORNING. CONDITIONS WILL IMPROVE LATER
IN THE MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...MM
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
416 AM CDT THU JUL 16 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
WIDESPREAD DEEP CONVECTION IS OCCURRING ACROSS NORTHEASTERN
ND...EXTENDING BACK INTO CENTRAL AND SOUTHERN ND...AHEAD OF A WEAK
MID LEVEL /H7-H5/ TROF. MUCAPE VALUES OF 500-1000 J/KG NOW ACROSS
ERN ND WILL SLOWLY TRANSLATE EWD AND INCREASE THROUGH THE
DAY...SUPPORTING CONTINUED DEEP CONVECTION ACROSS THE RRV AND
INTO NORTHERN MN THROUGHOUT THE FORENOON AND INTO THE AFTERNOON
AND EARLY EVENING.
PATCHY SUNSHINE AND ASSOCIATED SURFACE HEATING IS MOST LIKELY
ACROSS THE SOUTHERN RED RIVER BASIN...AND WILL PROVIDE SOME
INTENSIFICATION OF A WEAK SURFACE TROF THERE AND FOCUS FOR
STRONGER STORMS TO DEVELOP THROUGH THE AFTERNOON. NAM12 AND RAP13
BOTH SHOW UPWARDS OF 1000 J/KG OF CAPE IN THE 0-2KM FROM 18-21Z
THIS AFTERNOON ACROSS SERN ND...WITH HIGH VALUES TRANSLATING INTO
WCNTRL MN FROM LATE AFTERNOON INTO EARLY EVENING. HRRR AND NSSL
CAMS SHOW THE POSSIBILITY FOR SOME DISTINCTLY STRONGER CELLS IN
THE SOUTHERN RRV /19-22Z/ ...CONSISTENT WITH SPC DY1 CONVECTIVE
OUTLOOK AND MARGINAL RISK FOR SEVERE WEATHER THERE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU JUL 16 2015
FRIDAY NIGHT THROUGH SATURDAY...UPPER LEVEL SHORTWAVE TROF SWINGS
FROM EAST FLANK OF THE CANADIAN ROCKIES AND ACROSS THE NORTHERN
PLAINS THROUGH THE PERIOD SO WIDEPSREAD WETTING RAINS AND THUNDER
ARE TO BE EXPECTED...MAINLY FRIDAY EVENING INTO EARLY SATURDAY.
SURFACE TROF AXIS ACROSS THE SOUTHERN FA COULD PROVIDE A FOCUS
FOR SOME STRNGER STORMS THERE. SPC CONVECTIVE OUTLOOK AGAIN MAINTAINS
A MARGINAL TO SLIGHT RISK FOR SEVERE THUNDERSTORMS ACROSS THE FAR
SOUTHERN EDGE OF THE FA FROM DY2 INTO DY3.
SUNDAY THROUGH WEDNESDAY... MODELS IN GOOD AGREEMENT WITH
POSITIONING OF UPPER LEVEL FEATURES AS THE PATTERN BECOMES A
LITTLE MORE UNSETTLED. OTHERWISE...A LOW PRESSURE SYSTEM IS
EXPECTED TO CROSS THE NRN PLAINS ON MONDAY BRINGING SHOWERS AND
THUNDERSTORMS AHEAD OF IT...WITH A BIT COOLER AND DRIER AIR BEHIND
IT AS THE ASSOCIATED UPPER TROF MOVES THROUGH. LOOK FOR SFC HIGH
PRESSURE TO SHIFT OVER THE AREA BEHIND THE SYSTEM BRINGING MORE
TRANQUIL CONDITIONS THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CDT WED JUL 15 2015
THUNDERSTORM POTENTIAL THE MAIN AVIATION CONCERN. MOST ACTIVITY
THROUGH THE EARLY MORNING HOURS SHOULD REMAIN ALG AND NORTH OF
DVL- GFK- TVF LINE...WITH SCT THUNDERTSORM ACTIVITY STEADILY
MOVING INTO SERN ND THROUGH THE LATE MORNING. THUNDER CHANCES
INCREASE THROUGH THE DAY...MAINLY ACROSS THE NORTHERN RRV AND
NORTHWESTERN MN...WITH SCT ACTIVITY ACROSS THE OUTHERN RRV AND
WEST CENTRAL MN. MOST ALL ACTIVITY MOVING INTO NCNTRL MN BY EARLY
EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...GUST
LONG TERM...GUST/HOPKINS
AVIATION...TG/GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 AM CDT THU JUL 16 2015
.UPDATE...
ISSUED AT 1226 AM CDT THU JUL 16 2015
RECENT REFLECTIVITY HAS SHOWN STORMS ARE RAPIDLY DECREASING IN
INTENSITY...HOWEVER SHOWERS AND THUNDERSTORMS ARE STILL WIDESPREAD
ACROSS THE AREA. DO NOT ANTICIPATE ANY STRENGTHENING THROUGH THE
NIGHT AS STORMS PROGRESS EAST. OTHERWISE NO UPDATE TO PREVIOUS
FORECAST.
UPDATE ISSUED AT 919 PM CDT WED JUL 15 2015
ADJUSTED SHORT TERM POPS THROUGH THE NIGHT BASED ON CURRENT RADAR
TRENDS AND HRRR GUIDANCE...WHICH SEEMED TO HAVE A DECENT HANDLE ON
CURRENT CONVECTION. WATER VAPOR IMAGERY SHOWS SHORTWAVE MOVING
THROUGH MONTANA/WYOMING WHICH WILL CONTINUE TO SUPPORT CONVECTION
THROUGH THE NIGHT...WITH A GRADUAL DECREASE FROM WEST TO EAST. RECENT
TREND HAS BEEN FOR A SLIGHT WEAKENING IN CONVECTION...ALTHOUGH SPC
MESO PAGE SHOWS MU CAPE OF 2000-3000J/KG OVER MUCH OF THE CWA WITH
MARGINAL SHEAR IN PLACE. MAY STILL SEE SOME STRONG STORMS DEVELOP.
UPDATE ISSUED AT 519 PM CDT WED JUL 15 2015
NO SIGNIFICANT CHANGES TO THE GOING FORECAST. SCATTERED
THUNDERSTORMS CONTINUE OVER EASTERN MONTANA INTO THE WESTERN
DAKOTAS. SHORTWAVE IMPULSES MOVING THROUGH SOUTHWEST UPPER LEVEL
FLOW WILL CONTINUE TO PROVIDE SUPPORT FOR THUNDERSTORM DEVELOPMENT
IN A MOIST UNSTABLE AIRMASS OVER WESTERN AND CENTRAL NORTH DAKOTA
WITH AROUND 30 KTS OF 0-6KM SHEAR. THINK THE THREAT OF STRONG TO
POSSIBLY SEVERE STORMS WILL CONTINUE THROUGH THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 205 PM CDT WED JUL 15 2015
CURRENT SURFACE ANALYSIS PLACES WEAK LOW OVER SOUTHEAST MONTANA
INTO SOUTHWEST NORTH DAKOTA WITH LIGHT SOUTHERLY FLOW OVER MUCH OF THE
AREA. UPPER LEVEL ANALYSIS PLACES HIGH OVER THE SOUTHERN PLAINS
WITH RIDGE EXTENDING TO THE NORTH TOWARDS THE UPPER MIDWEST. A
VARIETY OF SHORT WAVES NOTED SLIDING UP SOUTHWESTERLY FLOW.
CURRENT WAVE OVER OUR AREA CONTINUES TO PRODUCE CONVECTION MAINLY
OVER THE JAMES RIVER VALLEY...WHILE A PAIR OF WAVES OVER EASTERN
MONTANA INTO NORTHERN WYOMING CONTINUE THEIR APPROACH...WITH A
VARIETY OF ADDITIONAL WAVES BEHIND.
FOR THE REST OF THIS AFTERNOON INTO THIS EVENING...THUNDERSTORMS
WILL CONTINUE TO DEVELOP OVER THE AREA THROUGH THIS AFTERNOON INTO
TONIGHT AS THE PARADE OF SHORT WAVES LIFT THROUGH THE REGION.
LATEST GUIDANCE STILL SUGGEST HIGHER INSTABILITY (2-3 KJ/KG) OVER
MUCH OF THE AREA THOUGH SHEAR IS MARGINAL...GREATEST TO THE NORTH.
WITH THAT SAID...WILL HAVE TO MONITOR FOR LARGE HAIL/STRONG WIND
THREAT INTO THIS EVENING. ANOTHER THING THAT WILL NEED TO BE
MONITORED IS THE LOCALIZED POTENTIAL FOR HEAVY RAIN...ESPECIALLY
IN TRAINING STORMS...AS ATMOSPHERE IS QUITE WET WITH MODELS
ESTIMATING PRECIPITABLE WATER VALUES ~160 PERCENT OF NORMAL.
ON THURSDAY...SHOWERS/THUNDERSTORMS WILL CONTINUE AS THE LAST OF
THE SHORT WAVES MAKES ITS WAY THROUGH THE REGION. MARGINAL
INSTABILITY EXPECTED OVER THE JAMES RIVER VALLEY...WITH LOWER
VALUES EXPECTED ELSEWHERE. THEREFORE...EXPECT THE SEVERE THREAT TO
BE QUITE LIMITED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 205 PM CDT WED JUL 15 2015
AN ACTIVE WEATHER PATTERN CONTINUES TO HIGHLIGHT THE EXTENDED
FORECAST.
MODELS REMAIN IN AGREEMENT EARLY IN THE LONG TERM PERIOD REGARDING A
TROUGH OVER THE ROCKIES WITH ZONAL TO SOUTHWESTERLY FLOW ALOFT OVER
NORTH DAKOTA. THURSDAY NIGHT INTO SATURDAY A STRONGER SHORTWAVE OVER
ALBERTA/SASKATCHEWAN MOVES EAST TOWARDS NORTH DAKOTA/MANITOBA...AND
LIFTS NORTHEASTWARD INTO ONTARIO SATURDAY AFTERNOON/NIGHT. HAVE
BETTER CHANCES OF THUNDERSTORMS THROUGH SATURDAY...THEN CHANCES ARE
BETTER FOR MORE ISOLATED SHOWERS AND THUNDERSTORMS SATURDAY NIGHT
AND SUNDAY.
THE MODELS THEN DEVELOP A DEEPENING UPPER LEVEL LOW OVER NORTHERN
CANADA...AND BRING THE WESTERLIES AND HENCE THE JET STREAM FARTHER
NORTH INTO SOUTHERN/CENTRAL CANADA. THIS RESULTS IN A MORE WEAKER
AND ZONAL FLOW EARLY NEXT WEEK WITH LOW OR NO CHANCES OF
PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1226 AM CDT THU JUL 16 2015
SHOWERS AND THUNDERSTORMS WERE SPREAD ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. DO NOT ANTICIPATE ANY STRONG STORMS THROUGH THE
NIGHT HOWEVER THUNDERSTORMS COULD IMPACT ANY OF THE 5 TERMINALS IN
WESTERN AND CENTRAL NORTH DAKOTA. STORMS WILL DIMINISH THROUGH THE
DAY FROM WEST TO EAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MM
SHORT TERM...JJS
LONG TERM...JV
AVIATION...MM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
730 PM EDT FRI JUL 17 2015
.SYNOPSIS...
SOUTHERLY FLOW PROVIDES WARMER AND MORE HUMID WEATHER WITH WEAK
DISTURBANCES ALOFT CAUSING SOME ISOLATED AFTERNOON/OVERNIGHT
CONVECTION. COLD FRONT IN VICINITY EARLY IN WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
730 PM UPDATE...CONVECTION CURRENTLY NEAR KCVG IS GRADUALLY
DRIFTING SOUTHEAST. HRRR SHOWS THIS CLUSTER WEAKENING AND MAINLY
STAYING TO OUR SW...BUT DID UPDATE POPS WITH CHANCE POPS INTO KY
COUNTIES BY LATE EVENING. REDUCED POPS AND CHANCE OF THUNDER
ACROSS THE NORTH...ALTHOUGH STILL HAD TO LEAVE SOME IN WITH UPPER
LEVEL DISTURBANCE MOVING THROUGH.
PREVIOUS DISCUSSION...RADAR AND MODELS ARE IN REASONABLE
AGREEMENT TO START THINGS OFF. MODELS VARY ON THEIR
REPRESENTATIONS FOR CONVECTION TONIGHT...BUT BY AND LARGE THE
CONSENSUS IS TO DRIFT SCATTERED CELLS DOWN THROUGH OUR FORECAST
AREA IN THE LATE AFTERNOON AND EVENING HOURS. THEY MAY EVEN LINGER
IN TO THE EARLY MORNING HOURS ON SATURDAY. THE FORCING FOR THESE
CELLS APPEARS WEAK WHICH WILL MAKE FOR A TOUGH FORECAST IN
TIMING/LOCATION OF THE LARGEST THREAT. ZONAL FLOW MAY INCREASE THE
THREAT FOR TRAINING IN AREAS THAT DO RECEIVE RAINFALL...WHICH IS
OF CONCERN DUE TO THE LOW FLASH FLOOD GUIDANCE FOLLOWING THIS PAST
WEEKS ACTIVE PATTERN. THE GOOD NEWS IS THE BULLSEYE APPEARS TO BE
RELEGATED TO THE MORE TOLERANT NORTHERN AREAS OF OUR FORECAST
AREA. OVERALL...THE THREAT FOR FLASH FLOODING IS LOW...BUT NOT
NEGLIGIBLE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
HEAT AND HUMIDITY WILL BE ON THE INCREASE ON SUNDAY. WITH HIGH
TEMPERATURES FORECAST TO BE IN THE UPPER 80S TO LOWER 90S ACROSS
THE REGION...AND DEW POINTS IN THE MID 70S...HEAT INDICES COULD
APPROACH THE UPPER 90S TO LOWER 100S. ELECTED TO GO AHEAD AND ADD
A MENTION OF A POSSIBLE HEAT ADVISORY FOR SUNDAY AFTERNOON INTO
THE HWO...FOR SOUTHEAST OH...NE KY...AND ADJACENT WV ZONES.
A COLD FRONT WILL GRADUALLY APPROACH THE AREA ON SUNDAY...WITH
SHOWERS AND THUNDERSTORMS INCREASING AS IT DOES SO. WITH THE HIGH
MOISTURE CONTENT OF THE AIR...AND OVERALL RELATIVELY WEAK
FLOW...THERE IS THE POSSIBILITY FOR FLASH FLOODING CONCERNS.
HIGHLIGHTED IN THE HWO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
COLD FRONT WILL MOVE INTO THE AREA ON MONDAY. THERE IS THE
POTENTIAL FOR A FEW STRONG TO SEVERE STORMS ON MONDAY...BUT THIS
IS STILL UP IN THE AIR A BIT...AND WILL RELY SOMEWHAT ON TIMING OF
FRONT. FRONTAL BOUNDARY WILL EVENTUALLY STALL OUT ACROSS THE
SOUTHERN HALF OF THE AREA BRIEFLY...BEFORE SAGGING SOUTH LATER IN
THE DAY ON TUESDAY. HOWEVER...ANOTHER SYSTEM WILL AFFECT THE AREA
MID TO LATE WEEK. THUS...HEADING INTO YET ANOTHER WET
PERIOD...WITH THE POTENTIAL FOR CONTINUED WATER PROBLEMS.
HIGHLIGHTED IN THE HWO.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
AREA OF MID AND UPPER CLOUDS...WITH SOME SHOWERS OR STORMS WILL
DRIFT ACROSS CWA THROUGH THE NIGHT. DESPITE MODEL GUIDANCE
SUGGESTING DENSE FOG ACROSS THE LOWLANDS WITH OUR CURRENT SOUPY
NEAR 70 DP AIR...THINK WE WILL KEEP ENOUGH FLOW AND HAVE CLOUD
COVER TO REDUCE CHANCES OF DENSE FOG. DID INCLUDE IT AT EKN. WITH
THAT SAID...SHOULD A SHOWER HIT A TAF SITE THAT COULD CHANGE
THINGS. EXPECT A BRIEF PERIOD OF MVFR CIGS AROUND TO JUST AFTER
SUNRISE AT SOUTHERN AND MOUNTAINOUS SITES. THEN VFR SHOULD PREVAIL
THROUGH THE DAY...ALTHOUGH DID INCLUDE VCTS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z
SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS...DENSE FOG COULD FORM IN THE VERY HUMID AIR.
MAY NEED TO ADD SHRA OR TSRA AS PATH OF CONVECTION TO OUR WEST
BECOMES MORE CERTAIN.
AFTER 00Z SUNDAY...IFR IN MORE WIDESPREAD SHOWERS/STORMS SUNDAY
NIGHT OR MONDAY NEAR FRONT.
&&
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JB/30/JW
NEAR TERM...MZ/JW
SHORT TERM...SL
LONG TERM...SL
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS MEDFORD OR
830 PM PDT FRI JUL 17 2015
.DISCUSSION...NO UPDATES PLANNED THIS EVENING. A RATHER SHARP
UPPER TROUGH IS BACKING IN OVER US FROM NORTHEAST OREGON THIS
EVENING. THE ASSOCIATED CUMULUS FIELD HAS THE LOOK OF A FRONT, AND
THE SURFACE PRESSURE PATTERNS ARE ALSO FRONTAL LIKE, BUT ALL THE
COOL ADVECTION IS OCCURRING ALOFT. WE HAVEN`T HAD ANY RADAR
RETURNS IN OUR FORECAST AREA YET, BUT THE 18/00Z NAM AND LATEST
RAP RUNS STILL SHOWS SOME SHOWER AND THUNDERSTORM POTENTIAL OVER
SOUTHERN LAKE COUNTY INTO MODOC COUNTY. THE HRRR SHOWS IT ALL
DEVELOPING SOUTH OF US. AT ANY RATE, IT IS CERTAINLY STILL WORTHY
OF THE SLIGHT CHANCE POPS WE HAVE IN THESE AREAS TONIGHT.
SOME INTERESTING OBSERVATIONS FROM BROOKINGS: THE CHETCO EFFECT
AND ITS EAST WIND BROUGHT A VERY HOT DAY TO THE CITY TODAY WITH
TEMPERATURES IN THE MID 90S BY NOON. THEN THE WIND CHANGED
DIRECTION TO THE NORTH AND TEMPERATURES COOLED BACK INTO THE 80S
THIS AFTERNOON. IN THE LAST HOUR THE WIND SWITCHED TO SOUTH, AND
WITH THE AIR COMING DIRECTLY OFF THE OCEAN, IT`S SUDDENLY IN THE
UPPER 60S. DRAMATIC TEMPERATURE CHANGES ARE NOT UNHEARD OF IN
BROOKINGS, BUT THAT`S A PRETTY BIG SWING! IT`S ALSO AN INDICATION
THAT THE THERMAL TROUGH IS SHIFTING INLAND, AND WILL RESULT IN
COOLER WEATHER TOMORROW FOR THE CURRY COAST. BY CONTRAST, THE
THERMAL TROUGH WILL BRING HOTTER WEATHER TO THE INTERIOR AREAS
TOMORROW AS IT SHIFTS INLAND. -WRIGHT
&&
.AVIATION...FOR THE 18/00Z TAF CYCLE... MODERATE EAST WINDS ACROSS
THE RIDGES OF THE COASTAL MOUNTAINS WILL PERSIST THROUGH SATURDAY
MORNING. THEY ARE EXPECTED TO KEEP FOG AND MARINE STRATUS FROM
FORMING ALONG THE COAST AND MAY PRODUCE LOW LEVEL TURBULENCE THIS
EVENING IN THE BROOKINGS AREA. VFR WITH SCATTERED COVERAGE OF CIRRUS
CLOUDS WILL PERSIST DURING THE NEXT 24 HOURS. /DW
&&
.MARINE...UPDATED 500 PM PDT, FRIDAY, 17 JULY 2015...A THERMAL
TROUGH WILL BRING STRONG NORTH WINDS AND VERY STEEP WIND DRIVEN SEAS
TO A PEAK THIS EVENING. WINDS WILL DIMINISH BUT REMAIN MODERATE OVER
THE OUTER WATERS INTO SATURDAY AFTERNOON WHILE SEAS REMAIN STEEP
THROUGH SATURDAY EVENING. SEAS ON SATURDAY WILL TRANSITION FROM
BEING DOMINATED BY WIND WAVES TO A FRESH NORTHWEST SWELL WHILE WINDS
BECOME WEAK NEAR SHORE SOUTH OF CAPE BLANCO. SEAS WILL THEN DIMINISH
SATURDAY NIGHT INTO EARLY WEDNESDAY WHILE WINDS WILL BE WEAK
SATURDAY NIGHT INTO MONDAY. THERE IS UNCERTAINTY REGARDING HOW SOON
STRONGER NORTHERLY WINDS WILL REDEVELOP. THE NAM IS THE WEAKEST
SOLUTION AND INDICATES WINDS WILL REMAIN WEAK INTO MONDAY EVENING
WHILE THE 18Z GFS IS STRONGER WITH WINDS IN THE OUTER WATERS SOUTH
OF CAPE BLANCO DURING MONDAY AFTERNOON AND EVENING...THOUGH IT DOES
KEEP SPEEDS BELOW ADVISORY LEVELS. WILL GO WITH A MODEL BLEND FOR
NOW. /DW
&&
.PREV DISCUSSION... /ISSUED 252 PM PDT FRI JUL 17 2015/
DISCUSSION... A WEAK UPPER LEVEL SYSTEM BRUSHES THE FAR SOUTHEAST
CORNER OF THE FORECAST AREA OVERNIGHT TONIGHT...BUT WITH
NORTHEASTERLY FLOW OVER THE ENTIRE REGION MOISTURE WILL BE LIMITED
AND HAVE KEPT JUST SLIGHT CHANCE POPS MOSTLY JUST IN MODOC COUNTY
TONIGHT. HEIGHTS RISE BEHIND THIS EXITING SYSTEM WITH OFFSHORE
FLOW CONTINUING THROUGH SATURDAY MORNING. THIS WILL BRING
QUICK HEATING WITH HIGH TEMPERATURES NEARING OR TOPPING 100
DEGREES SATURDAY. SUNDAY WILL SEE ONSHORE FLOW ACROSS THE EAST
SIDE BY THE AFTERNOON...BUT WITH THE MORNING STARTING WARM
SUNDAY`S HIGH TEMPERATURES SHOULD BE SIMILAR TO SATURDAY`S.
LINGERING MOISTURE BEHIND THE EXITING SYSTEM SATURDAY WILL BRING
INSTABILITY TO THE SOUTHEAST PORTIONS OF THE FORECAST AREA
SATURDAY AFTERNOON...BUT WITH A DRY LAYER MOVING IN IN NORTHERLY
FLOW THIS SHOULD BE OUT OF THE AREA EARLY IN THE EVENING. THE
UPPER LEVEL RIDGE SLOWLY WEAKENS NEXT WEEK...WITH SLOW COOLING FOR
THE EARLY PART OF THE WORK WEEK. ON WEDNESDAY THE UPPER TROUGH
DEEPENS CONSIDERABLY WITH TEMPERATURES DROPPING MORE TOWARDS
NORMAL MID WEEK. MODELS ARE SHOWING SOME DIFFERENCES IN THE TIMING
OF THE UPPER TROUGH PASSAGE TOWARDS THE END OF THE WORK WEEK WITH
THE BEST CHANCES OF PRECIPITATION LOOKING TO BE THURSDAY BEFORE
THE UPPER TROUGH SHIFTS EAST. SVEN
FIRE WEATHER...UPDATED 200 PM PDT, FRIDAY 17 JULY 2015... EAST
WINDS WITH LOW RELATIVE HUMIDITIES CONTINUE THIS AFTERNOON ALONG AND
NEAR THE CURRY COUNTY COAST. WHILE RELATIVE HUMIDITIES HAVE
GENERALLY BEEN VERY LOW IN FIRE WEATHER ZONE 618, RECOVERIES LAST
NIGHT WERE HIGH ENOUGH TO PREVENT RED FLAG WARNING CONDITIONS. EVEN
AT RED MOUND, THE RECOVERY OF 30% WAS RIGHT ON THE EDGE OF THE
RECOVERY FOR EAST WIND CRITERIA. TONIGHT IT APPEARS THAT RELATIVE
HUMIDITIES WILL BE AT RED FLAG WARNING LEVELS WITH SOME OF THE RIDGE
TOPS ONLY EXPECTED TO RECOVER INTO THE 25-29% RANGE, BUT EAST WINDS
ARE EXPECTED TO DIMINISH BELOW THE 15MPH+ GUSTING TO 30MPH+
CRITERIA. THUS, WE`LL CONTINUE TO HEADLINE NEAR CRITICAL CONDITIONS,
BUT FOREGO A WARNING.
OTHERWISE, AN UPPER LEVEL LOW MOVING INTO NORTHEASTERN CALIFORNIA
WILL BRING WITH IT THE POSSIBILITY OF THUNDERSTORMS LATE TONIGHT
THROUGH SATURDAY EVENING. THE GREATEST THREAT OF THUNDERSTORMS IN
THIS AREA IS SATURDAY AFTERNOON AND EVENING, BUT THERE IS A SLIGHT
POSSIBILITY ACTIVITY COULD BREAK OUT EARLY SATURDAY MORNING AS UPPER
LEVEL ENERGY ARRIVE FROM THE NORTHEAST. HOWEVER, MOST GUIDANCE KEEPS
THIS INITIAL AREA WEAK AND SOUTH OF OUR FIRE WEATHER ZONES. THE
GREATEST THREAT IS OVER THE MODOC, BUT THERE IS A LESSER THREAT
EXTENDING NORTHWESTWARD INTO THE MEDICINE LAKE TO MOUNT SHASTA AREA
IN FIRE WEATHER ZONES 282 AND 284, AS WELL. THESE STORMS ARE
EXPECTED TO BE ISOLATED AND SHOULD MOVE GENERALLY NORTHWEST TO
SOUTHEAST AT ONLY 5-10 MPH. THEY WILL CAPABLE OF LIGHT TO MODERATE
RAINFALL AND SMALL HAIL.
THE THREAT FOR THUNDERSTORMS DIMINISHES ON SUNDAY. THERE IS AN
OUTSIDE CHANCE OF A THUNDERSTORM OVER THE SOUTHEASTERN CORNER OF FWZ
285. FOR MONDAY WE MAY NEED TO ADD SOME ISOLATED STORMS FROM THE
TRINITY ALPS TO ABOUT LAKEVIEW, AS TODAY`S MODELS HAVE TRENDED IN
THAT DIRECTION. AN UPPER LEVEL TROUGH MOVING IN MID-LATE WEEK WILL
BRING WITH IT A THREAT OF GUSTY WINDS OVER THE CASCADES AND EAST
SIDE AHEAD OF IT TUESDAY INTO WEDNESDAY, AS WELL AS A THREAT FOR
ISOLATED THUNDERSTORMS OVER PORTIONS OF FREMONT-WINEMA NATIONAL
FOREST CENTERED ON ABOUT THURSDAY. IT SHOULD BE NOTED THERE IS ONLY
LOW CONFIDENCE IN THE TIMING OF FEATURES WITH THIS TROUGH AROUND THE
MIDDLE OF NEXT WEEK. BTL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 AM PDT SATURDAY FOR
PZZ350-356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT SATURDAY
FOR PZZ350-356.
GALE WARNING UNTIL 2 AM PDT SATURDAY FOR PZZ356-376.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT SATURDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT SATURDAY FOR
PZZ370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT SATURDAY
FOR PZZ370-376.
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
943 PM EDT FRI JUL 17 2015
.SYNOPSIS...
WARMER AND MUCH MORE HUMID CONDITIONS WILL PREVAIL THROUGH THE
WEEKEND AS AN UPPER LEVEL RIDGE BUILDS OVER THE NORTHEAST CONUS
THIS WEEKEND. A SHORT WAVE PASSING TO THE NORTH WILL PUSH A COLD
FRONT THROUGH PENNSYLVANIA ON MONDAY. HIGH PRESSURE IS LIKELY TO
BUILD SOUTHEAST INTO PENNSYLVANIA WEDNESDAY OR THURSDAY OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
930 PM UPDATE...
SHRA/TSRA ON TRACK AND SLIDING INTO THE WRN MTNS. OVERALL...TIMING
AND COVERAGE REMAIN SIMILAR. DECENT SOUTH WIND STILL GOING FOR
THIS TIME OF NIGHT...AS 925MB WINDS INCREASE TO 30 KTS OUT OF THE
SSE FOR THE NEXT FEW HOURS AHEAD OF THIS SHORT WAVE. TEMPS WILL
STAY UP IN THE M60S TO L70S FOR THE NIGHT. MUGGY IS THE WORD.
WELCOME BACK SUMMER.
6 PM UPDATE...
ALL CONVECTION OVERHEAD AND INTO WESTERN OHIO HAS DISSIPATED. NEXT
FORCING DOES NOT COME ALONG FOR 3-5 MORE HOURS WHEN A SHORT WAVE
TROUGH MOVES INTO PA FROM THE WEST. CURRENT RADAR OVER NW OHIO
DEPICTS A SMALL CLUSTER OF STORMS WHERE THE FORCING MAY BE
GREATEST AT THIS TIME. MORE STORMS ARE FORMING BACK IN FAR LWR MI.
DEWPOINTS ARE IN THE M70S IN C OH...AND ARE CLIMBING INTO THE U60S
HERE. HAVE DIPPED POPS INITIALLY THIS EVENING...THEN BROUGHT THEM
BACK TO THE GOING FCST FOR AFTER MIDNIGHT AND INTO THE MORNING -
GENERALLY ISOLD/SCT POPS. THE MAIN FOCUS WILL BE ON THAT AREA OF
SHRA/TSRA MOVING IN FROM THE W/NW. WILL TRY SOME ROUGH TIMING TO
CAPTURE THAT FEATURE.
PREV...
MOISTURE FLOWING RAPIDLY BACK INTO THE REGION THIS AFTERNOON...WITH
NOTICEABLE STICKINESS RETURNING AS DEWPOINTS RISE THROUGH THE 60S
THROUGHOUT. BROAD MCV LIFTING ACROSS THE FINGERLAKES REGION AND
LAKE ONTARIO IS MAINTAINING WIDESPREAD SHOWERS NORTH OF THE PA/NY
BORDER THIS AFTERNOON...WITH A TRAILING LINE OF SHOWERS ALONG AN
UPPER SHEAR AXIS THAT EXTENDS INTO WEST CENTRAL PA. SHOWERS ALONG
THIS SOUTHERN FLANK HAVE BEEN WEAKENING FOR THE LAST SEVERAL
HOURS...MUCH AS THE HRRR DEPICTED. STILL... EXPECT ISOLD TO SCT
SHRA TO CROSS THE NORTHWEST AND WEST CENTRAL MOUNTAINS THROUGH MID
AFTERNOON AND THEN ISOLATED ACTIVITY TO PUSH INTO THE CENTRAL
MOUNTAINS AND LAUREL HIGHLANDS WITH JUST A SLIGHT CHANCE OF A
THUNDERSTORM IN SOME SPOTS.
OTHERWISE...LOTS OF MID LEVEL DEBRIS FROM THE UPSTREAM CONVECTION
OVER OHIO IS KEEPING MY FAR NORTHWEST NEARLY OVERCAST...WHILE
PARTLY TO MOSTLY CLOUDY SKIES ARE DISTRIBUTED OVER THE REMAINDER
OF CENTRAL PA. AS THE SHEAR AXIS CROSSES CENTRAL PA AND EXITS TO
THE EAST BY 04Z...WE SHOULD SEE PARTIAL CLEARING THROUGHOUT. SOME
AREAS OF VALLEY FOG ARE POSSIBLE.
ANOTHER ROUND OF SHOWERS IS POSSIBLE AFT 04Z AS ANOTHER UPSTREAM
SHORTWAVE LIFTS INTO ONTARIO FROM THE EASTERN GLAKS. NOTICEABLE
INCREASE IN HUMIDITY TONIGHT WITH A MUCH WARMER NIGHT THAN THOSE
RECENTLY...WITH MIN TEMPS MOSTLY IN THE M/U60S.
&&
.SHORT TERM /7 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
BOUNDARY LAYER MOISTURE CONTINUES TO INCREASE ON SATURDAY...WITH
RIDGING ALOFT COUNTERACTING THE POTENTIAL DESTABILIZATION OF
INCREASING SFC DEWPOINTS AND HEAT. STILL SHOULD SEE ISOLD TO LCLLY
SCT AFTERNOON CONVECTION FIRING OVER THE HIGHER TERRAIN...BUT WITH
NO SHEAR TO ORGANIZE...NOT EXPECTING ANY SIGNIFICANT IMPACTS. JUST
ANOTHER NON-DRY DAY TO ADD TO THE PILE WE`VE ACCUMULATED THIS
SUMMER. HEATING OF VERY WARM/UNSTABLE AIR MASS IN THE WARM SECTOR
SHIELD MODERATE CAPES BY AFTN...BUT AGAIN TRIGGER WILL BE THE
LIMITING FACTOR. MODEL OUTPUT INDICATES A DECENT LIKELIHOOD OF LEE
TROF OVER SOUTHEAST PA...WHICH APPEARS TO BE THE MAIN FOCUS FOR
INITIATION OTHER THAN ELEVATED HEAT SOURCES. IF INSTABILITY CAN
BE RELEASED...MODERATE CAPES AND RELATIVELY WEAK SHEAR IN MDL DATA
DOES YIELD A LOW END THREAT OF ISOLD PULSE TYPE SVR STORMS.
HIGHEST POPS WILL BE INDICATED OVER THE SOUTHEAST IN VICINITY OF
THE LEE TROF. SPC HAS US IN GENERAL THUNDER AREA FOR DAY 2.
WESTERN AREAS WILL ONLY SEE A SLIGHT CHC TO LOW CHC OF A PASSING
SHOWER OR THUNDERSTORM IN THE AFTERNOON OR EVENING.
BOUNDARY LAYER WARMING SUPPORTS WIDESPREAD HIGHS OF 85 TO 90. THIS
COMBINED WITH SFC DEWPOINTS RISING TO AROUND 70 OR THE LOWER 70S
WILL CREATE HEAT INDICES IN THE MID TO UPPER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE RETURN TO MORE SUMMERLIKE WEATHER WILL CONTINUE ON
SUNDAY...AS 850HPA TEMPS RISE TO +2SD BY SUNDAY AFTN. AS TEMPS
CONTINUE TO WARM AND HUMIDITY CONTINUES TO CLIMB...HEAT INDICES
WILL APPROACH 100F /BORDERLINE HEAT ADVISORY CRITERIA/ IN THE
LOWER SUSQUEHANNA VALLEY SUNDAY AFTN.
A COLD FRONT WILL CROSS CENTRAL PA SUN NIGHT/EARLY
MONDAY...ACCOMPANIED BY A CHC FOR SHRA/TSRA. THE TIMING OF THE
FRONT EARLY IN THE DAY MAY BE A LIMITING FACTOR FOR SEVERE WX.
BEHIND THE FRONT...TEMPS WILL BE /SLIGHTLY/ COOLER AND THERE WILL
BE A RESPITE FROM THE MUGGINESS.
HIGH PRESSURE WILL ATTEMPT TO BUILD OVERHEAD LATE NEXT
WEEK...BEHIND ANOTHER WEAK COLD FRONT THAT IS FORECAST TO SETTLE
ACROSS CENTRAL PA NEXT WEDNESDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
A NON-TRIVIAL INFLUX OF LOW LEVEL MOISTURE IS MOVING INTO THE
STATE THIS EVENING. DEWPOINTS HAVE INCREASED INTO THE UPPER 60S
OVER THE WEST AND THIS WILL SPREAD EAST OVERNIGHT.
THIS MOISTURE WILL ALLOW FOR A LOWERING OF BOTH CEILINGS AND
VISIBILITY INTO THE IFR CATEGORY AROUND 06Z/18JUL...AND PERSIST
TO JUST AFTER SUNRISE. SHORT RANGE ENSEMBLE FORECASTS INDICATE A
LINE OF SHOWERS MOVING ACROSS THE STATE BETWEEN 06Z/18JUL AND
10Z/18JUL. ADDED VCSH TO THE CENTRAL AND WESTERN TAFS FOR A SHORT
PERIOD OVERNIGHT TO ACCOUNT FOR THIS.
CONDITIONS DRY OUT FOR THE DAYTIME HOURS ON SATURDAY WITH VFR
CEILINGS AND VISIBILITIES. AN ISOLATED SHOWER IS POSSIBLE AS
DEWPOINTS REMAIN NEAR 70...HOWEVER NOT ENOUGH COVERAGE TO PLACE
IN THE EXTENDED PORTION OF THE FORECAST.
OUTLOOK...
SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE-WED...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...EVANEGO
AVIATION...TYBURSKI
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
754 PM EDT FRI JUL 17 2015
.SYNOPSIS...
WARMER AND MUCH MORE HUMID CONDITIONS WILL PREVAIL TONIGHT
THROUGH THIS WEEKEND AS AN UPPER LEVEL RIDGE BUILDS OVER THE
NORTHEAST CONUS THIS WEEKEND. A SHORTWAVE PASSING TO THE NORTH
WILL PUSH A COLD FRONT THROUGH PENNSYLVANIA ON MONDAY. HIGH
PRESSURE IS LIKELY TO BUILD SOUTHEAST INTO PENNSYLVANIA WEDNESDAY
OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
6 PM UPDATE...
ALL CONVECTION OVERHEAD AND INTO WESTERN OHIO HAS DISSIPATED. NEXT
FORCING DOES NOT COME ALONG FOR 3-5 MORE HOURS WHEN A SHORT WAVE
TROUGH MOVES INTO PA FROM THE WEST. CURRENT RADAR OVER NW OHIO
DEPICTS A SMALL CLUSTER OF STORMS WHERE THE FORCING MAY BE
GREATEST AT THIS TIME. MORE STORMS ARE FORMING BACK IN FAR LWR MI.
DEWPOINTS ARE IN THE M70S IN C OH...AND ARE CLIMBING INTO THE U60S
HERE. HAVE DIPPED POPS INITIALLY THIS EVENING...THEN BROUGHT THEM
BACK TO THE GOING FCST FOR AFTER MIDNIGHT AND INTO THE MORNING -
GENERALLY ISOLD/SCT POPS. THE MAIN FOCUS WILL BE ON THAT AREA OF
SHRA/TSRA MOVING IN FROM THE W/NW. WILL TRY SOME ROUGH TIMING TO
CAPTURE THAT FEATURE.
PREV...
MOISTURE FLOWING RAPIDLY BACK INTO THE REGION THIS AFTERNOON...WITH
NOTICEABLE STICKINESS RETURNING AS DEWPOINTS RISE THROUGH THE 60S
THROUGHOUT. BROAD MCV LIFTING ACROSS THE FINGERLAKES REGION AND
LAKE ONTARIO IS MAINTAINING WIDESPREAD SHOWERS NORTH OF THE PA/NY
BORDER THIS AFTERNOON...WITH A TRAILING LINE OF SHOWERS ALONG AN
UPPER SHEAR AXIS THAT EXTENDS INTO WEST CENTRAL PA. SHOWERS ALONG
THIS SOUTHERN FLANK HAVE BEEN WEAKENING FOR THE LAST SEVERAL
HOURS...MUCH AS THE HRRR DEPICTED. STILL... EXPECT ISOLD TO SCT
SHRA TO CROSS THE NORTHWEST AND WEST CENTRAL MOUNTAINS THROUGH MID
AFTERNOON AND THEN ISOLATED ACTIVITY TO PUSH INTO THE CENTRAL
MOUNTAINS AND LAUREL HIGHLANDS WITH JUST A SLIGHT CHANCE OF A
THUNDERSTORM IN SOME SPOTS.
OTHERWISE...LOTS OF MID LEVEL DEBRIS FROM THE UPSTREAM CONVECTION
OVER OHIO IS KEEPING MY FAR NORTHWEST NEARLY OVERCAST...WHILE
PARTLY TO MOSTLY CLOUDY SKIES ARE DISTRIBUTED OVER THE REMAINDER
OF CENTRAL PA. AS THE SHEAR AXIS CROSSES CENTRAL PA AND EXITS TO
THE EAST BY 04Z...WE SHOULD SEE PARTIAL CLEARING THROUGHOUT. SOME
AREAS OF VALLEY FOG ARE POSSIBLE.
ANOTHER ROUND OF SHOWERS IS POSSIBLE AFT 04Z AS ANOTHER UPSTREAM
SHORTWAVE LIFTS INTO ONTARIO FROM THE EASTERN GLAKS. NOTICEABLE
INCREASE IN HUMIDITY TONIGHT WITH A MUCH WARMER NIGHT THAN THOSE
RECENTLY...WITH MIN TEMPS MOSTLY IN THE M/U60S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
BOUNDARY LAYER MOISTURE CONTINUES TO INCREASE ON SATURDAY...WITH
RIDGING ALOFT COUNTERACTING THE POTENTIAL DESTABILIZATION OF
INCREASING SFC DEWPOINTS AND HEAT. STILL SHOULD SEE ISOLD TO LCLLY
SCT AFTERNOON CONVECTION FIRING OVER THE HIGHER TERRAIN...BUT WITH
NO SHEAR TO ORGANIZE...NOT EXPECTING ANY SIGNIFICANT IMPACTS. JUST
ANOTHER NON-DRY DAY TO ADD TO THE PILE WE`VE ACCUMULATED THIS
SUMMER. HEATING OF VERY WARM/UNSTABLE AIR MASS IN THE WARM SECTOR
SHIELD MODERATE CAPES BY AFTN...BUT AGAIN TRIGGER WILL BE THE
LIMITING FACTOR. MODEL OUTPUT INDICATES A DECENT LIKELIHOOD OF LEE
TROF OVER SOUTHEAST PA...WHICH APPEARS TO BE THE MAIN FOCUS FOR
INITIATION OTHER THAN ELEVATED HEAT SOURCES. IF INSTABILITY CAN
BE RELEASED...MODERATE CAPES AND RELATIVELY WEAK SHEAR IN MDL DATA
DOES YIELD A LOW END THREAT OF ISOLD PULSE TYPE SVR STORMS.
HIGHEST POPS WILL BE INDICATED OVER THE SOUTHEAST IN VICINITY OF
THE LEE TROF. SPC HAS US IN GENERAL THUNDER AREA FOR DAY 2.
WESTERN AREAS WILL ONLY SEE A SLIGHT CHC TO LOW CHC OF A PASSING
SHOWER OR THUNDERSTORM IN THE AFTERNOON OR EVENING.
BOUNDARY LAYER WARMING SUPPORTS WIDESPREAD HIGHS OF 85 TO 90. THIS
COMBINED WITH SFC DEWPOINTS RISING TO AROUND 70 OR THE LOWER 70S
WILL CREATE HEAT INDICES IN THE MID TO UPPER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE RETURN TO MORE SUMMERLIKE WEATHER WILL CONTINUE ON
SUNDAY...AS 850HPA TEMPS RISE TO +2SD BY SUNDAY AFTN. AS TEMPS
CONTINUE TO WARM AND HUMIDITY CONTINUES TO CLIMB...HEAT INDICES
WILL APPROACH 100F /BORDERLINE HEAT ADVISORY CRITERIA/ IN THE
LOWER SUSQUEHANNA VALLEY SUNDAY AFTN.
A COLD FRONT WILL CROSS CENTRAL PA SUN NIGHT/EARLY
MONDAY...ACCOMPANIED BY A CHC FOR SHRA/TSRA. THE TIMING OF THE
FRONT EARLY IN THE DAY MAY BE A LIMITING FACTOR FOR SEVERE WX.
BEHIND THE FRONT...TEMPS WILL BE /SLIGHTLY/ COOLER AND THERE WILL
BE A RESPITE FROM THE MUGGINESS.
HIGH PRESSURE WILL ATTEMPT TO BUILD OVERHEAD LATE NEXT
WEEK...BEHIND ANOTHER WEAK COLD FRONT THAT IS FORECAST TO SETTLE
ACROSS CENTRAL PA NEXT WEDNESDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
A NON-TRIVIAL INFLUX OF LOW LEVEL MOISTURE IS MOVING INTO THE
STATE THIS EVENING. DEWPOINTS HAVE INCREASED INTO THE UPPER 60S
OVER THE WEST AND THIS WILL SPREAD EAST OVERNIGHT.
THIS MOISTURE WILL ALLOW FOR A LOWERING OF BOTH CEILINGS AND
VISIBILITY INTO THE IFR CATEGORY AROUND 06Z/18JUL...AND PERSIST
TO JUST AFTER SUNRISE. SHORT RANGE ENSEMBLE FORECASTS INDICATE A
LINE OF SHOWERS MOVING ACROSS THE STATE BETWEEN 06Z/18JUL AND
10Z/18JUL. ADDED VCSH TO THE CENTRAL AND WESTERN TAFS FOR A SHORT
PERIOD OVERNIGHT TO ACCOUNT FOR THIS.
CONDITIONS DRY OUT FOR THE DAYTIME HOURS ON SATURDAY WITH VFR
CEILINGS AND VISIBILITIES. AN ISOLATED SHOWER IS POSSIBLE AS
DEWPOINTS REMAIN NEAR 70...HOWEVER NOT ENOUGH COVERAGE TO PLACE
IN THE EXTENDED PORTION OF THE FORECAST.
OUTLOOK...
SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE-WED...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...EVANEGO
AVIATION...TYBURSKI
EQUIPMENT...
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1005 AM EDT THU JUL 16 2015
.DISCUSSION...
EARLY MORNING FOG HAS DISSIPATED...AND MOSTLY SUNNY SKIES ARE
EXPECTED FOR THE REST OF THE DAY. CONVECTIVE DEVELOPMENT POTENTIAL
APPEARS SLIM TO NIL TODAY AS 12Z RAOBS AROUND THE REGION ALL SHOW
A STRONG INVERSION BETWEEN 850 AND 700 MB. THE NAM AND HRRR SHOW
SOME DEVELOPMENT ALONG THE MOUNTAINS...WHICH MAY BE OVERDONE BUT
WILL CONTINUE WITH THE MENTION OF SLIGHT CHANCE POPS IN THOSE
AREAS. TEMPERATURES ARE ON TRACK SO FAR...SO NO UPDATE WILL BE
NEEDED.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
117 AM EDT THU JUL 16 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD NORTH OF THE REGION LATER
TONIGHT AND THURSDAY...REACHING THE MID ATLANTIC COAST THURSDAY
NIGHT INTO FRIDAY. THIS WILL BRING SOMEWHAT COOLER AND LESS HUMID
AIR TO THE REGION OVERNIGHT AND THURSDAY. UPPER LEVEL HIGH
PRESSURE WILL BUILD EAST INTO THE AREA THIS WEEKEND RESULTING IN
HOTTER AND MORE HUMID WEATHER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 112 AM EDT THURSDAY...
UPDATING TO EXPAND POPS BETWEEN LYH AND DAN GIVEN CONTINUED
PERSISTENT NATURE TO SLOW MOVING SHOWERS CURRENTLY ONGOING OUT
EAST. LATEST HRRR SHOWS MOST OF THIS COVERAGE FADING WELL BEFORE
DAYBREAK BUT GIVEN STRENGTH OF THE LOW LEVEL THETA-E INTO
SOUTHSIDE VA MAY ACTUALLY SEE THINGS INCREASE OVER THE NEXT COUPLE
OF HOURS AS THE FLOW TURNS MORE EASTERLY. THIS SIMILAR TO THE
LATEST NAM WHICH HAS SOME ISOLATED SHRA PERSISTING AND SHIFTING SW
INTO THE MORNING.
PREVIOUS DISCUSSION AS OF 1030 PM EDT WEDNESDAY...
SEEING ISOLATED POCKETS OF LIGHT SHOWERS IN THE PIEDMONT FADING.
THE LATEST HRRR/00Z NAM HANG ONTO A FEW SHOWERS FOR THE NEXT
COUPLE HOURS TRAVERSING THE FOOTHILLS OF VA AND NEAR THE BLUE
RIDGE. OTHERWISE A QUIET NIGHT AS SFC HIGH MOVES EAST ACROSS THE
GREAT LAKES INTO NEW YORK/QUEBEC. DEWPOINTS IN THE 50S POISED
ACROSS NRN OHIO INTO PA AND MAY SPILL SWD TOWARD THE ALLEGHANY
HIGHLANDS BY MORNING...BUT MOST PLACES STILL STUCK IN THE 60S. NOT
CHANGING TO OVERNIGHT LOWS MUCH FROM THE LOWER 60S MOUNTAINS TO
UPPER 60S PIEDMONT. PATCHY FOG TIL 800 AM OVER THE MTNS AS WELL
ADDED TO GRIDS...UNDER PARTLY CLOUDY SKIES.
BUFKIT SHOWED ONLY A SHALLOW LAYER OF MOISTURE LEFT BY THURSDAY
AFTERNOON. 12Z LOCAL WRF WAS SHOWING NORTH TO NORTHEAST SURFACE
WINDS BY THURSDAY BY 12Z THURSDAY WITH LOWER DEW POINTS PUSHING
SOUTH INTO THE PIEDMONT. SOME OTHER MODEL NOT AS AGGRESSIVE WITH
THE DRIER AIR BUT WILL STILL HAVE LOWER DEW POINTS IN THE EASTERN
COUNTY WARNING AREA LATE TONIGHT AND THURSDAY.
HAVE ISOLATED SHOWERS IN THE FAR SOUTHWEST ON THURSDAY AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 115 PM EDT WEDNESDAY...
OUR FORECAST WILL CONTINUE TO BE PRIMARILY A DRY ONE THROUGH FRIDAY.
HIGH PRESSURE WILL STILL BE IN CONTROL OF OUR WEATHER
PATTERN...ALTHOUGH THE CENTER OF IT SILL START TO HEAD EAST IN
ADVANCE OF OUR NEXT GREAT LAKES REGION SHORTWAVE TROUGH. ENOUGH
RETURN FLOW MOISTURE WILL INTERSECT THE CREST OF THE BLUE RIDGE.
THIS WILL DAYTIME HEATING MAY BE ENOUGH TO PRODUCE SOME ISOLATED
SHOWERS AND STORMS BY FRIDAY AFTERNOON. ANY THAT FORM ARE EXPECT TO
DISSIPATE AFTER SUNSET.
FRIDAY NIGHT INTO SATURDAY NIGHT...WE WILL SEE A PATTERN CHANGE WITH
THE UPPER RIDGE OVER THE EAST COAST RETROGRADING THE MIDDLE
MISSISSIPPI VALLEY. THIS WILL ALLOW FOR THE NORTHERN JET TO ADVECT A
SHORTWAVE TROUGH FROM THE GREAT LAKES REGION INTO AND THROUGH OUR
REGION. ANTICIPATE AN INCREASE IN ISOLATED TO SCATTERED SHOWERS AND
STORMS LATE FRIDAY NIGHT IN THE WEST. ACTIVITY WILL INCREASE WITH
THE HEATING OF THE DAY ON SATURDAY...AND TRAVERSE THE REGION FROM
WEST TO EAST. BY SATURDAY NIGHT...THE BULK OF THE ACTIVITY WILL BE
EAST OF OUR REGION...BUT RESIDUAL MOISTURE AND A CONTINUATION OF
NORTHWEST...UPSLOPE FLOW IN THE WEST WILL HELP MAINTAIN SOME
ISOLATED TO SCATTERED SHOWERS AND STORMS INTO LATE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 145 PM EDT WEDNESDAY...
WE WILL REMAIN IN A PATTERN OF UNSETTLED WEATHER THROUGH MOST...IF
NOT ALL...OF THIS PORTION OF THE FORECAST. WITH THE UPPER RIDGE
CENTERED TO OUR WEST...DAYTIME HEATING WILL BE ENOUGH TO GENERATE
SOME ISOLATED TO SCATTERED SHOWERS AND STORMS ACROSS THE AREA...ALL
WHILE TEMPERATURES SLOWLY CLIMB IN ADVANCE OF OUR NEXT COLD FRONT.
TEMPERATURES WILL BE ON THE HOT SIDE ON MONDAY. HIGHS IN THE
MOUNTAINS WILL BE IN THE MID TO UPPER 80S WITH LOW TO MID 90S ACROSS
THE PIEDMONT. PARTS OF SOUTHSIDE VIRGINIA MAY EXPERIENCE HEAT INDEX
VALUES AROUND OR A LITTLE OVER 100 DEGREES. WHILE TEMPERATURES WILL
BE A LITTLE COOLER ACROSS THE MOUNTAINS ON TUESDAY...SIMILAR HIGH
TEMPERATURES AND HEAT INDEX VALUES ARE EXPECTED ACROSS THE PIEDMONT.
SMALL PIECES OF ENERGY WITHIN THE OVERALL NORTHWEST FLOW MAY PROMPT
LOCALIZED INCREASES IN COVERAGE OF THE PRECIPITATION SUNDAY THROUGH
MONDAY.
GUIDANCE IS FAIRLY CONSISTENT ON A COLD FRONT MOVING INTO THE AREA
LATE MONDAY NIGHT INTO TUESDAY...MOVING EAST OF THE AREA TUESDAY
EVENING. WHAT IS NOT CONSISTENT IS HOW QUICKLY...AND HOW FAR
GEOGRAPHICALLY...IT PROGRESSES OUT OF THE AREA WITH HIGH PRESSURE
BUILDING IN BEHIND IT. THE GFS OFFERS A SOLUTIONS THAT STALLS THE
FRONT OVER THE AREA WITH SHOWERS AND STORMS CONTINUING ACROSS MUCH
OF THE AREA ON WEDNESDAY. THE ECWMF ALLOWS FOR PROGRESS OF THE FRONT
OFF THE EAST COAST BY TUESDAY EVENING...WITH DRIER AND COOLER HIGH
PRESSURE FIRMLY OVER THE AREA BY WEDNESDAY. OUR FORECAST WILL
REFLECT THAT OF THE SLOWER SOLUTION WITH PRECIPITATION CONTINUING
INTO WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 100 AM EDT THURSDAY...
CLOUD COVER CONTINUES TO EXPAND WITH CIGS LOWERING ACROSS THE
REGION TONIGHT AIDED BY WEAK LOW LEVEL CONVERGENCE AND DEVELOPING
EASTERLY FLOW. ALSO SEEING ISOLATED SHRA PERSIST ALONG THE KLYH-
KDAN CORRIDOR WHERE MSAS SHOWS AN AXIS OF MUCH HIGHER LOW LEVEL
THETA-E NORTH OF THE SURFACE FRONT TO THE SOUTH. EXPECT THESE
SHOWERS TO LINGER FOR AT LEAST A FEW MORE HOURS PER LATEST HRRR
WITH SOME OF THIS POSSIBLY AFFECTING BOTH KDAN/KLYH SO INCLUDING A
VCSH THROUGH ABOUT DAYBREAK.
OTRW EXPECTING CIGS TO LOWER INTO LOW END VFR OR MVFR MOST
LOCATIONS GIVEN EXPANDING STRATO-CU UNDER THE INVERSION ALOFT OVERNIGHT
WITH IFR/LIFR AT KBLF IN STRATUS/FOG. FOG REMAINS TRICKY ELSEWHERE
AS THE CLOUD CANOPY EXPANDS AND LIMITS RADIATIONAL COOLING MOST
SPOTS. THINK COULD STILL SEE SOME MVFR TYPE VSBYS AT KLWB/KBCB BUT
LOW CONFIDENCE UNDER NE FLOW AS WELL SO KEPT BUMPED VSBYS UP A
NOTCH THERE AND LEFT OUT MENTION IN THE EAST.
LOW CONFIDENCE AS TO HOW FAST CEILINGS AT KLWB AND KBLF WILL
IMPROVE THURSDAY MORNING UNDER LIGHT EASTERLY FLOW. BUT WILL HAVE
ALL SITES VFR IN THE 13-15Z TIME FRAME AS SHOULD SEE CIGS MIX OUT
EARLY ON AS MODELS SHOW BETTER DRYING FROM THE NORTH DEVELOPING.
EXTENDED AVIATION DISCUSSION...
VFR THURSDAY NIGHT INTO FRIDAY. NOT EXPECTING ANY ORGANIZED
PRECIPITATION FOR THE LATER HALF OF THE WEEK.
WITH OPPORTUNITY FOR CLEARING TO TAKE PLACE AT NIGHT...WILL HAVE
SOME MORNING FOG/LOW CLOUDS ISSUES IN THE MOUNTAIN VALLEYS...AND
GROUND FOG FOR THE LOW LYING AREAS OF THE FOOTHILLS AND PIEDMONT.
OVERALL CONDITIONS HOWEVER SHOULD BE MAINLY VFR.
WIDELY SCATTERED MORE DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS
RETURN TO THE REGION ON SATURDAY AND SUNDAY WITH POSSIBLY MORE
WIDESPREAD COVERAGE ON MONDAY AHEAD OF THE NEXT COLD FRONT. MVFR
TO IFR CONDITIONS ARE POSSIBLE WITH ANY OF THE STORMS. OTHERWISE
VFR CEILINGS AND VISIBILITIES ARE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...AMS/JH/WP
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 254 PM CDT THU JUL 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE UPPER
FLOW BACKING THIS AFTERNOON AS A SHORTWAVE TROUGH LIFTS NORTHEAST
INTO WISCONSIN. THIS SHORTWAVE IN COMBO WITH A LLJ IS PRODUCING A
BAND OF SHOWERS THAT IS MOVING INTO CENTRAL WISCONSIN. THE BACKING
FLOW ALOFT IS ALSO PUSHING A SURFACE WARM FRONT NORTHEAST ACROSS THE
CENTRAL PLAINS. PLENTY OF LOW CEILINGS NORTH OF THE WARM FRONT AND
BEHIND THE BAND OF SHOWERS. FORECAST CONCERNS INCLUDE PRECIP TRENDS
TONIGHT AND MAX TEMPS ON FRIDAY.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE NORTHEAST ACROSS NORTHEAST
WISCONSIN THIS EVENING. THE LATEST SHORT RANGE MODELS ARE QUITE
AMBITIOUS CRANKING OUT RAINFALL OVER EAST-CENTRAL WISCONSIN...BUT
THE AIRMASS IS QUITE STABLE OVER THE REGION AT THE MOMENT. THOUGH
MOISTURE IS PLENTIFUL...IT WILL BE TOUGH TO GET HEAVY RAINFALL
WITHOUT INSTABILITY OR STRONG FORCING...AND BOTH APPEAR TO BE
ABSENT. BUT WILL STILL GO WITH PRECIP CHANCES IN THE 60-80% RANGE
THIS EVENING WITH AROUND A QUARTER INCH OF RAINFALL. AS THE RAIN
EXITS LATE IN THE EVENING OR EARLY OVERNIGHT...CLOUDS SHOULD LOWER
AND CREATE A WIDESPREAD OVERCAST DECK WITH SOME LOWER VSBYS IN MIST.
LOWS WILL BE MORE MILD AS A RESULT...AND WENT WITH MINS IN THE UPPER
50S TO LOWER 60S.
FRIDAY...THE WARM FRONT WILL STALL OVER CENTRAL WISCONSIN BUT
SHORTWAVE RIDGING WILL BE MOVING OVERHEAD WHICH WILL INCREASE
SUBSIDENCE ALOFT. AS A RESULT...THINK THE DAY WILL BE A DRY ONE
THOUGH WILL START OFF RATHER CLOUDY. THESE CLOUDS SHOULD LIFT BY
MID TO LATE MORNING. THEN CONDITIONS TURN WARM AND MUGGY WITH HIGHS
IN THE LOW TO MID 80S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 254 PM CDT THU JUL 16 2015
ZONAL FLOW WITH FAIRLY STRONG WINDS ALOFT FOR MID SUMMER IS EXPECTED
MOST OF THE TIME DURING THIS PERIOD...WITH A FEW SHORTWAVES MOVING
THROUGH EVERY TWO OR THREE DAYS.
THE FIRST ONE COMES THROUGH SATURDAY AFTERNOON AND EVENING WITH
ASSOCIATED SURFACE FRONT. SOUTHERLY FLOW WILL BRING WARM AND HUMID
AIR UP INTO WISCONSIN WITH MODELS FORECASTING HIGH TEMPERATURES IN
THE UPPER 80S TO LOW 90S WITH DEWPOINTS AROUND 70F. THE MODELS
HAVE BEEN A BIT TOO WARM SO FAR THIS SEASON SO NOT SURE IF 90F IS
LIKELY OR NOT. IF IT DOES GET THAT WARM WITH 70F DEWPOINTS HEAT INDICES
WILL BE CLOSE TO ADVISORY CRITERIA OF 100F. FORECAST CAPE OF 3000
J/KG SATURDAY AFTERNOON WILL PRESENT A SEVERE THUNDERSTORM THREAT.
SLIGHTLY COOLER AND DRIER AIR WILL ARRIVE SUNDAY AND MONDAY WITH
TEMPERATURES JUST A COUPLE DEGREES ABOVE NORMAL. ANOTHER SHORTWAVE
TROUGH COMES BY MONDAY NIGHT OR TUESDAY WITH ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS FOLLOWED BY DRY WEATHER WEDNESDAY AND
THURSDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1156 AM CDT THU JUL 16 2015
MID AND UPPER LEVEL CLOUDS CONTINUE TO STREAM IN AHEAD OF AN
APPROACHING WARM FRONT AND WEAK UPPER DISTURBANCE. LOOK FOR CIGS TO
LOWER FROM SOUTHWEST TO NORTHEAST THIS AFTERNOON...ALONG WITH
SHOWERS SPREADING INTO CENTRAL WISCONSIN EARLY IN THE TAF PERIOD.
THESE SHOWERS AND ISOLD T-STORMS WILL MOVE INTO THE FOX VALLEY AND
LAKESHORE AREAS LATE THIS AFTERNOON. CIGS WILL CONTINUE TO LOWER
THIS EVENING IN THE RAINFALL. WIDESPREAD IFR/LIFR CIGS ARE POSSIBLE
OVERNIGHT ALONG THE WARM FRONT UNTIL THE CLOUDS MIX OUT BY MID TO
LATE MORNING ON FRIDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
614 AM CDT THU JUL 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT THU JUL 16 2015
MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES TODAY/THIS
EVENING...FOG LATER TONIGHT.
06Z DATA ANALYSIS HAD HIGH PRESSURE CENTERED OVER THE EASTERN GREAT
LAKES AND LOW PRESSURE IN THE CENTRAL/NORTHERN PLAINS. SOUTHERLY
FLOW/MOISTURE ADVECTION BETWEEN THE TWO WAS SPREADING NORTH ACROSS
IA/MN. LOW LEVEL JET AND STRONGER OF THE MOISTURE RETURN/CONVERGENCE
WAS OVER WESTERN IA...WHERE CONVECTION WAS FIRING AND SPREADING
SLOWLY EAST AND NORTH. STRONGER OF THE CONVECTION WAS NEAR THE MO/IA
BORDER...IN THE STRONGER MOISTURE FLOW AND CLOSER TO THE CAPE POOL.
CONVECTION ACROSS CENTRAL/NORTHERN IA MAINLY SHRA WITH ISOLATED
TSRA...IN AN AREA OF DIVERGENCE/LIFT ALOFT AHEAD A SHORTWAVE OVER
EASTERN NEB. ELSEWHERE...CLOUDS WERE INCREASING ACROSS WI/MN WITH
SHRA/TSRA MOVING ACROSS ND WITH/AHEAD OF ANOTHER STRONGER SHORTWAVE.
NO PROBLEMS NOTED WITH 16.00Z MODEL INITIALIZATIONS. HOWEVER WEAKER
GRADIENT/HGT FIELDS AT MANY LEVELS THIS TIME OF YEAR DO ALLOW FOR
SUBTLE DIFFERENCES AMONG THE INITIALIZATIONS. MODELS IN GOOD
AGREEMENT TO MOVE A SHORTWAVE OVER EASTERN IA TO SOUTHERN LK MI BY
12Z THIS MORNING...THEN DIFFER ON DETAILS OF ENERGY TO FOLLOW IT AND
MOVE ACROSS THE AREA LATER TODAY. BETTER AGREEMENT AGAIN ON THE ND
SHORTWAVE TO MOVE INTO NORTHWEST MN BY 00Z THEN INTO SOUTHWEST ONT
TONIGHT. OVERALL TREND IS TOWARD A TIGHTER CONSENSUS TODAY/TONIGHT.
BUT...DETAIL DIFFERENCES ON THE SHORTWAVE ENERGY MOVING ACROSS THE
REGION TODAY/THIS EVENING AND THEIR IMPACTS ON SHRA/TSRA EVOLUTION
LEAD TO AVERAGE CONFIDENCE IN THE SHORT-TERM THIS CYCLE.
FOR THE SHORT TERM...SHORTWAVE DIFFERENCES TODAY INTO THIS EVENING
LEAD TO A VARIETY OF CONVECTIVE OUTCOMES ACROSS THE FCST AREA.
OVERALL CONSENSUS IS A STRONG SOUTHWARD SHIFT OF SHRA/TSRA CHANCES
AND HEAVER PRECIP FROM MODEL RUNS OF 15.00Z. THIS PLAYING OUT
ALREADY THIS MORNING WITH TSRA COMPLEX IN SOUTHWEST IA MARKING THE
NOSE OF THE LOW LEVEL JET AND STRONGER MOISTURE TRANSPORT/
CONVERGENCE. THIS COMPLEX INTERCEPTING MUCH OF THE MOISTURE/CAPE
THIS MORNING AS IT MOVES ACROSS CENTRAL/SOUTHERN IA WITH THE VEERING
LOW LEVEL JET. DEEPER MOISTURE/HIGHER PW AIRMASS DOES LOOK TO MAKE
IT INTO THE FCST AREA BUT THE STRONGER LOW LEVEL THERMO-DYNAMIC
FORCING NOW TRENDS SOUTH OF THE FCST AREA...WITH LESSER PRECIP
CHANCES/AMOUNTS ACROSS THE AREA TODAY...TIED TO PASSING WEAK
SHORTWAVES. BULK OF BOTH STANDARD AND HI-RES/WRF MODELS NOW SPREAD A
WEAKENING BAND OF SHRA/TSRA EAST/NORTHEAST ACROSS THE FCST AREA
TODAY...WEAKENING AS THE BAND MOVES AWAY FROM THE STRONGER LOW LEVEL
THERMO-DYNAMIC FORCING. SHIFTING HIGHER PRECIP CHANCES TODAY TO THE
SOUTH HALF OF THE FCST AREA ALONG WITH HIGHER RAIN AMOUNTS. ANY
SEVERE TSRA THREAT TODAY SHIFTS SOUTH OF THE FCST AREA AS WELL...
WITH GENERALLY LIMITED CAPE INTO THE AREA EVEN BY 00Z. ND SHORTWAVE
AND ITS FORCING/LIFT STAY WELL NORTH OF THE FCST AREA TONIGHT WITH
PASSAGE OF THE SFC-MID LEVEL TROUGH AXIS AROUND 06Z. CONTINUED TO
TREND PRECIP CHANCE DOWN FROM WEST TO EAST THRU THE EVENING WITH
MAINLY A DRY FCST OVERNIGHT. SOME DRYING/SUBSIDENCE INDICATED IN THE
WAKE OF THE PASSING TROUGH AXIS...FOR DECREASING CLOUDS OVERNIGHT.
WITH LIGHT WINDS...SOME CLEARING AND RESIDUAL BOUNDARY LAYER
MOISTURE CONTINUED THE PATCHY FOG MENTION AFTER 06Z TONIGHT TO ABOUT
12Z FRI MORNING. USED A BLEND OF THE GUIDANCE HIGHS/LOWS FOR
TODAY/TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 358 AM CDT THU JUL 16 2015
MAIN FCST CONCERNS FOR FRI THRU SAT NIGHT...SHRA/TSRA CHANCES FRI
NIGHT THRU SAT NIGHT...SEVERE TSRA RISK SAT AFTERNOON/EVENING...
TEMPERATURES.
MODEL RUNS OF 16.00Z IN GOOD AGREEMENT FOR WEAK SHORTWAVE RIDGING TO
MOVE ACROSS THE UPPER MIDWEST FRI. THIS IS SHORT-LIVED AS MODELS
QUICKLY BRING THE NEXT STRONGER SHORTWAVE ENERGY INTO ND BY 12Z
SAT...THEN TRACK THIS EAST ALONG THE US/CAN BORDER SAT/SAT NIGHT AND
LOWER HGTS ACROSS THE REGION. TREND FAVORS FASTER OF THE EARLIER
MODEL RUNS WITH THIS SHORTWAVE/TROUGH. SMALLER SCALE SHORTWAVE
DETAIL DIFFERENCES ALSO NOTED IN THIS PERIOD...HAVING POTENTIAL
IMPACTS ON TIMING/LOCATION OF CONVECTION FRI NIGHT THRU SAT NIGHT.
FAVORING THE MODEL CONSENSUS...FCST CONFIDENCE FOR FRI THRU SAT
NIGHT IS AVERAGE THIS CYCLE.
THIS PERIOD STARTS OUT WITH WEAK BUT DRIER HIGH PRESSURE AND THE
SHORTWAVE RIDGING ALOFT MOVING ACROSS THE REGION. LITTLE IN THE WAY
OF FORCING/LIFT SIGNALS SEEN ON FRI. BUFKIT SOUNDINGS SHOWING SOME
CAPPING/CIN REMAINS OVER THE AREA ON FRI WITH SOME OF THE DRIER 900-
850MB AIR MIXING DOWN AND SFC DEW POINTS MORE IN THE MID 60S TO
AROUND 70 VS. THE 70S SHOWN IN THE NAM/GFS SFC DEW POINT PROGS. LEFT
FRI DRY. A WARM AIRMASS OVER THE AREA FRI WITH 925MB TEMPS
SUPPORTING HIGHS IN THE MID 80S TO AROUND 90S. WITH DEW POINTS
AROUND 70...FRI AFTERNOON HEAT INDICES CLIMB INTO THE 90-95 RANGE
FOR MUCH OF THE AREA. DEEPER MOISTURE ALREADY STARTS TO RETURN FRI
NIGHT...AHEAD OF THE TROUGH MOVING INTO ND. PLENTY OF DETAIL
DIFFERENCES WHERE ANY STRONGER LOWER LEVEL FORCING/CONVERGENCE MAY
FOCUS BUT SOME 20-40 PERCENT SHRA/TSRA CHANCES ACROSS MAINLY THE
NORTHWEST HALF OF THE FCST AREA FRI NIGHT REASONABLE FOR NOW. MORE
FOCUSED LOW LEVEL FORCING/CONVERGENCE/LIFT LOOKING TO MOVE
INTO/ACROSS THE FCST AREA SAT/SAT NIGHT WITH APPROACH/PASSAGE OF THE
SFC-805MB FRONT/TROUGH BEING DRAGGED EAST BY THE LOW/TROUGH MOVING
ACROSS SOUTHERN CAN. PW VALUES BACK IN THE 2 INCH RANGE AHEAD OF
THIS FRONT/TOUGH BY 00Z SUN. THIS WITH MUCAPE IN THE 2K-4K J/KG
RANGE SAT AFTERNOON AND 0-6KM SHEAR INCREASING INTO THE 30-40KT
RANGE. THE STRONGER SHEAR MORE SAT NIGHT WITH APPROACH OF THE
TROUGH. BUFKIT SOUNDING SHOWING SOME CAPPING SAT AFTERNOON...RATHER
WEAK BY LATE IN THE DAY. AS IN SWODY3 STRONG TO POTENTIALLY SEVERE
TSRA WITH THIS SYSTEM MAY BE MORE SAT NIGHT AS THE SFC-850MB FRONT/
TROUGH MOVE IN. GIVEN DETAIL DIFFERENCES...STAYED WITH CONSENSUS 20-
50 PERCENT SHRA/ TSRA CHANCES SAT...HIGHEST NORTH...THEN CONTINUED
THE 50-60 PERCENT CHANCES SAT NIGHT. SAT TO BE ANOTHER WARM/MUGGY
DAY WITH HEAT INDICES IN THE 90-100 RANGE BY AFTERNOON. FAVORED A
BLEND OF THE GUIDANCE HIGHS/LOWS FOR FRI THRU SAT NIGHT.
FOR SUNDAY THRU WEDNESDAY...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...LINGERING SHRA/TSRA CHANCES
SUNDAY...RETURNING SHRA/TSRA CHANCES TUE NIGHT/WED.
MEDIUM RANGE MODELS OF 16.00Z OFFER REASONABLE AGREEMENT ON THE MID
LEVEL TROUGH DROPPING ACROSS THE REGION SUNDAY AND A SECONDARY
SHORTWAVE TO DROP ACROSS THE REGION SUN NIGHT. AREA IS UNDER A
MUDDIED NORTHWEST FLOW MON INTO TUE...WITH THE FLOW TRANSITIONING TO
QUASI-ZONAL FOR WED. THE USUAL SHORTWAVE DETAIL DIFFERENCES ARE
PRESENT...ESPECIALLY BY MON INTO WED. COMING OUT OF UNCERTAINTIES
WITH THE SYSTEM FOR TODAY AND AGAIN SAT/SAT NIGHT...FCST CONFIDENCE
IN THE DAY 4-7 PERIOD IS AVERAGE AT BEST THIS CYCLE.
PASSING TROUGH SAT NIGHT SWEEPS THE DEEPER MOISTURE/HIGHER PW
AIRMASS OUT OF THE REGION...WITH MORE SEASONABLE TEMPERATURES AND
MOISTURE OVER THE AREA FOR SUN-WED. THIS UNDER THE MUDDIED NORTHWEST
FLOW ALOFT. SUN-TUE TRENDS DRIER UNDER THE NORTHWEST FLOW ALOFT BUT
THIS FAR FROM CERTAIN WITH POTENTIAL FOR SHORTWAVES TO RIPPLE
SOUTHEAST THRU THIS FLOW AND ACROSS THE AREA. WILL HAVE TO WATCH
TIMING OF THE SAT NIGHT FRONT/TROUGH...WITH POTENTIAL FOR IT TO SLOW
AND NOT PASS UNTIL SUNDAY. LINGERING SHRA/TSRA CHANCES ACROSS THE
SOUTHEAST 2/3 OF THE FCST AREA SUN GOOD FOR NOW. COOLER HIGH
PRESSURE THEN LOOKS TO SETTLE ACROSS THE REGION FOR SUN NIGHT/MON
WITH A SLOW WARMUP/RETURN OF MOISTURE MON NIGHT INTO WED AS THE HIGH
MOVES SOUTH AND THE NEST TROUGH/FRONT APPROACHES FROM THE NORTHWEST.
SMALL SHRA/TSRA CHANCES TUE NIGHT/WED AS THIS TROUGH WOULD APPROACH/
MOVE INTO THE REGION OKAY FOR NOW. GIVEN THE LESSER CONFIDENCE IN
THE DAY 4-7 PERIOD...STAYED WITH THE MODEL/ENSEMBLE CONSENSUS
HIGHS/LOWS FOR SUN-WED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 614 AM CDT THU JUL 16 2015
AN AREA OF SHOWERS WAS ADVANCING SLOWLY TO THE NORTHEAST THIS
MORNING. EXTRAPOLATING OUT THE LEADING EDGE PUTS IT INTO KRST
AROUND 13Z AND TO KLSE AT 14Z OR SO. INITIALLY NOT EXPECTING ANY
VISIBILITY REDUCTIONS WITH VFR CEILINGS BUT AFTER A COUPLE HOURS
OF THE LIGHT RAIN COULD SEE SOME MVFR CONDITIONS DEVELOP. THE
16.09Z RAP FORECAST SOUNDINGS DO NOT DEVELOP ANY CAPE FOR EITHER
SITE SO WILL KEEP IT JUST SHOWERS FOR NOW. THE 16.09Z HRRR SEEMS
TO HAVE A GOOD HANDLE ON THESE SHOWERS AND SUGGESTS THE BACK EDGE
WILL MOVE THROUGH EITHER LATE THIS MORNING OR VERY EARLY THIS
AFTERNOON. THAT VERY WELL COULD BE ALL THE RAIN FOR TODAY AS THE
16.00Z AND 16.06Z MESO-MODELS SUGGEST THAT ANY REDEVELOPMENT THIS
AFTERNOON WOULD BE SOUTHEAST OF BOTH TAF SITES. THE 16.06Z GFS
SUGGESTS THE MVFR DECK SHOULD SCATTER OUT THIS EVENING SETTING UP
THE POTENTIAL FOR FOG OVERNIGHT. STILL SOME UNCERTAINTY ON THIS AS
THE WINDS SHOULD COME AROUND TO THE SOUTHWEST TO WEST TO HELP KEEP
THE BOUNDARY LAYER MIXED...ESPECIALLY AT KRST SO WILL ONLY GO DOWN
TO A MVFR VISIBILITY OVERNIGHT. THE WINDS AT KLSE MAY DECOUPLE
MORE IN THE VALLEY WHICH COULD ALLOW THE VISIBILITY TO GO TO IFR
FOR A WHILE...BUT CONFIDENCE ON THIS IS LOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
309 AM MDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 308 AM MDT SAT JUL 18 2015
SWLY FLOW ALOFT WILL BE OVER THE AREA TODAY THRU TONIGHT. AT THE
SFC A WK SURGE MOVED ACROSS NERN CO LAST EVENING BUT HAS PRETTY
MIXED OUT THE LAST FEW HOURS. OVERALL AM GETTING CONFLICTING
SIGNALS ON HOW THE SFC PTRN IS GOING TO EVOLVE THIS AFTN. THE NAM
AND HIRES MODEL WANT TO BRING ANOTHER SURGE INTO NERN CO BY MIDDAY
WHILE THE HRRR AND RAP KEEP THIS BNDRY FURTHER NORTH OVER SERN WY
AND WRN NE THRU THE AFTN HOURS. AS A RESULT DEWPOINTS MIX OUT INTO
THE 30S AND 40S IN THE RAP AND HRRR WHILE THE NAM AND HIRES KEEP
THEM IN THE 50S. FURTHERMORE THIS LEADS TO LARGE DIFFERENCES IN
FCST CAPE BY MID TO AFTN WITH 2000 J/KG OR MORE ACROSS NERN CO AS
SHOWN BY THE NAM WITH 500-1000 J/KG IN THE HRRR AND RAP. ANOTHER
PROBLEM TO CONSIDER IS THAT EVEN IF THE NAM IS CORRECT WITH THE MUCH
HIGHER CAPE VALUES IT HAS A DECENT CAP IN PLACE THRU THE AFTN ACROSS
ALL OF NERN CO. IN ADDITION THERE IS SOME MID LVL DESCENT SHOWN AS
WELL THRU THE AFTN HOURS WHICH COULD LIMIT TSTM ACTIVITY AS WELL.
AT THIS POINT THERE ARE SO MANY CONFLICTING SIGNALS EVEN IF I ADJUST
THINGS I COULD GO IN THE WRONG DIRECTION SO WILL LEAVE INHERITED
POPS ALONE FOR THE AFTN HOURS. NATURALLY IF THE HIGHER CAPE VALUES
ARE IN PLACE AND THE CAP IS BKN THERE WOULD CERTAINLY BE THE
POTENTIAL FOR SOME SVR STORMS DUE TO FAVORABLE SHEAR. CIPS GUIDANCE
SHOWS THE HIGHEST POTENTIAL OVER THE NERN PLAINS MAINLY NE OF A LINE
FROM BRIGGSDALE TO WIGGINS TO LAST CHANCE.
OVER THE HIGHER TERRAIN STORMS WILL BE HIGH BASED AND PRODUCE GUSTY
WINDS BUT LIMITED RAINFALL. MEANWHILE ANOTHER PROBLEM FOR TODAY IS
HIGH TEMPERATURES. DEPENDING ON THE TIMING OF THE COOL FNT HIGHS
COULD EASILY RISE BACK INTO THE LOWER TO MID 90S ACROSS NERN CO IF
THE FNT IS SLOWER LIKE THE RAP/HRRR SHOW. FOR NOW WILL KEEP
READINGS IN THE MID 80S TO NR 90 HOWEVER THEY MAY END UP BEING TOO
COOL.
FOR THIS EVENING LOW LVL MOISTURE WILL INCREASE OVER THE PLAINS
BEHIN THE COOL FNT AS SOME WK MID LVL ASCENT MOVE ACROSS. THIS
SHOULD LEAD TO A BETTER CHC OF STORMS ACROSS NERN CO WITH SOME OF
THE ACTIVITY POSSIBLY LINGERING AFTER MIDNIGHT OVER THE FAR NERN
PLAINS. ONCE AGAIN THERE WILL BE THE POTENTIAL FOR A FEW SVR
STORMS ALONG WITH SOME HEAVY RAINFALL WELL DUE TO INCREASING
PRECIPITABLE WATER VALUES. LATE TONIGHT WITH SEE AREAS OF STRATUS
DVLP OVER MUCH OF NERN CO DUE TO UPSLOPE FLOW AND INCREASING LOW
LVL MOISTURE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 308 AM MDT SAT JUL 18 2015
INCREASED MOISTURE THROUGH THE BEGINNING OF THE WEEK WILL INCREASE
CONVECTION WITH SLIGHTLY BELOW AVERAGE TEMPERATURES. LOOK FOR DRIER
AND WARMER CONDITIONS TOWARD THE END OF THE WEEK.
SUNDAY WILL BRING MOSTLY CLOUDY CONDITIONS WITH SLIGHTLY COOLER
TEMPERATURES DUE IN PART TO A FRONT THAT WILL PUSH THROUGH THE
REGION EARLIER IN THE MORNING. MOISTURE PW VALUES WILL INCREASE ABOVE
1 INCH WITH ENHANCED UPSLOPE FLOW. WARMING AND THEREFORE CONVECTION
WILL BE INHIBITED THROUGH THE DAY BY CLOUD COVER AND MID LEVEL
STABILITY. WILL MAINTAIN SCATTERED STORMS OVER THE MOUNTAINS WITH
ONLY ISOLATED ON THE PLAINS TOWARD THE LATE AFTERNOON AND EVENING.
MAIN THREATS WILL BE HEAVY RAIN AND WINDS WITH THE STORMS.
SUNDAY NIGHT INTO MONDAY WILL SEE STORMS CONTINUING INTO EARLY
MORNING BEFORE DISSIPATING. WESTERLY UPPER LEVEL FLOW INCREASES WITH
A SLIGHT DROP IN PW VALUES AS THE MOISTURE GETS CUTS OFF.
HOWEVER...WITH LINGERING MOISTURE IN THE MOUNTAINS WILL MAINTAIN
INCREASED POPS FOR MONDAY AS AFTERNOON OROGRAPHICS COULD HELP SPARK
SOME CONVECTION IN THE AFTERNOON. HIGHS FOR MONDAY WILL INCREASE
SLIGHTLY FROM SUNDAY INTO THE MID 80S.
TUESDAY AND WEDNESDAY...THE UPPER LEVEL RIDGE THAT IS DOMINATING THE
SOUTHERN PORTIONS OF THE CONUS WILL START TO BREAK DOWN AND MOVE
SOUTH ONCE AGAIN INCREASING SUBTROPICAL MOISTURE OVER THE REGION
TUESDAY AFTERNOON INTO WEDNESDAY. THERE WILL BE INCREASED STORM
COVERAGE TUESDAY AND WEDNESDAY AFTERNOONS. CAPE VALUES ARE NOT
IMPRESSIVE BUT SOME BRIEF HEAVY RAIN AND HIGH WINDS WILL BE POSSIBLE
WITH STORM DEVELOPMENT.
THURSDAY INTO THE START OF THE WEEKEND...MODELS ARE SHOWING A DRIER
AND WARMER PATTERN TAKING PLACE. TEMPERATURES WILL INCREASE INTO THE
LOWER 90S BY THE END OF THE WEEK. WILL KEEP A SLIGHT CHANCE OF
STORMS IN THE MOUNTAINS BUT AT THIS POINT DO NOT SEE MUCH POTENTIAL
FOR DEVELOPMENT OVER THE PLAINS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 308 AM MDT SAT JUL 18 2015
WINDS WERE SWLY EARLY THIS MORNING HOWEVER VWP SHOWS THEM NELY JUST
ABOVE THE BNDRY LYR SO EXPECT ONCE MIXING OCCURS THEY WILL BECOME
MORE NELY BY 16Z AND THEN GRADUALLY MORE SELY BY EARLY AFTN.
CONFIDENCE IN TSTM FCST THIS AFTN NOT HIGH AS EXPLAINED ABV. IF LOW
LVL MOISTURE IS LACKING MAY SEE A FEW HIGH BASED STORMS BY 21Z WITH
GUSTY WINDS FOR A FEW HOURS. MEANWHILE DEPENDING ON TIMING OF COOL
FNT COULD SEE A BETTER CHC OF STRONGER STORMS IN THE 00Z-03Z TIME
PERIOD WITH MVFR CONDITIONS POSSIBLE. WINDS THIS EVENING SHOULD
BECOME MORE E OR NE WITH THE POTENTIAL FOR STRATUS AND SOME FOG LATE
TONIGHT INTO SUN MORNING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...BOWEN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
454 AM EDT SAT JUL 18 2015
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS MUCH OF THE SOUTHERN
TIER OF THE CONUS UNDER THE DOMAIN OF A LARGE ELONGATED REGION OF
MID/UPPER LEVEL RIDGING. THIS RIDGE IS CENTERED OVER THE LOWER MS
VALLEY...PLACING FLORIDA ON THE FAR EASTERN PERIPHERY OF THE
CIRCULATION. WV IMAGERY SHOWS ABUNDANT MID/UPPER LEVEL MOISTURE IN
PLACE OVERHEAD...AND THIS WAS CONFIRMED WITH THE 18/00Z KTBW
SOUNDING PROFILE WHICH MEASURED THE PW VALUE AT OVER 2.1". THE
PROFILE ALSO SHOWED THE DEEPER MOISTURE EXTENDING DOWN INTO THE
LOWER LEVELS OF THE TROP...WHERE THE FLOW WAS MORE WESTERLY OFF
THE GULF. OVERALL THE ATMOSPHERIC PROFILE SAMPLED LAST NIGHT AND
FORECAST THROUGH THE WEEKEND IS ONE THAT IS UNSTABLE AND CONDUCIVE
TO THE DEVELOPMENT OF NUMEROUS SHOWERS/STORMS...AND ALSO
CONDUCIVE TO HEAVY RAINFALL POTENTIAL. THEREFORE THE GREATEST
WEATHER THREAT OVER THE WEEKEND WILL BE THE POTENTIAL FOR HEAVY
RAINFALL OVER AREAS THAT HAVE ALREADY SEEN SIGNIFICANT TOTALS THE
PAST SEVERAL DAYS. FROM DAY TO DAY IT IS DIFFICULT TO DETERMINE
JUST WHERE THE BEST POTENTIAL FOR TRAINING STORMS MAY SET UP OFF
THE GULF...BUT IT IS POSSIBLE THAT ONCE THE CONVECTIVE PATTERN
BECOMES MORE CLEAR LATER THIS MORNING...THAT SIMILAR TO
FRIDAY...FLOOD WATCHES MAY BECOME NECESSARY FOR PARTS OF THE
REGION.
AS OF JUST AFTER 400 AM EDT...RADAR WAS SHOWING RENEWED SHOWER
ACTIVITY BEGINNING TO MIGRATE BACK ONSHORE INTO THE TAMPA BAY
AREA...WITH MORE NUMEROUS CONVECTION OVER THE OFFSHORE WATERS TO
THE SOUTH OF CEDAR KEY. BASED ON THE PATTERN AND ENSEMBLE
GUIDANCE...WOULD EXPECT THE TREND TO BE INCREASING COVERAGE OF
SHOWERS/STORMS DURING THE NEXT SEVERAL HOURS...ESPECIALLY NEAR THE
COAST.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
A MESSY AND SHOWERY PATTERN REMAIN IN PLACE...AND WILL REMAIN IN
PLACE THROUGH THE WEEKEND. MUCH OF THE REGION RESIDES UNDER AN
ENVIRONMENT OF DEEP LAYER MOISTURE WITH A LOW LEVEL FLOW FROM THE
WEST/SOUTHWEST OFF THE GULF OF MEXICO. THIS PATTERN IS FAVORABLE
FOR SCT-NMRS SHOWERS AND STORMS TO DEVELOP EARLY IN THE MORNING
OVER THE COASTAL WATERS AND MIGRATE ONSHORE THROUGHOUT THE
MORNING. DIURNAL HEATING AND OUTFLOW FROM THE MORNING COASTAL
CONVECTION THEN GETS CONVECTION GOING BY MIDDAY (IF NOT
BEFORE) OVER THE INTERIOR ZONES. THERE WILL BE SOME DRIER AIR
ABOVE THE SURFACE TRYING TO ADVECT DOWN TOWARD THE NORTHERN NATURE
COAST...BUT IT APPEARS THAT THIS PUSH WILL STALL JUST TO OUR
NORTH...OR POSSIBLY SNEAK FAR ENOUGH SOUTH TO DECREASE THE RAIN
CHANCES FOR LEVY COUNTY. ELSEWHERE...WE ARE IN THE MOISTURE AND
THE FORECAST WILL BE FOR OFF AND ON SHOWERS.
AS MENTIONED ABOVE...THE PW VALUES ACROSS THE REGION ON FAIRLY
HIGH. THE 00Z KTBW SOUNDING SHOWED A PW VALUE OVER THE 90TH
PERCENTILE OF VALUES FOR THE MIDDLE OF JULY...AND MANY OF THE
GUIDANCE MEMBERS SHOW THIS VALUE INCREASING FURTHER TODAY.
THEREFORE...THE POTENTIAL IS THERE FOR SOME OF THE SHOWERS TO
PRODUCE VERY HEAVY RAINFALL...ESPECIALLY IF WE END UP WITH ANY
TRAINING BANDS OF STORMS...WHICH DO TEND TO BE FAVORED WITHIN THE
OBSERVED SOUTHWEST FLOW. LOCATIONS THAT ARE UNLUCKY ENOUGH TO END
UP UNDER ONE OF THESE BANDS CAN QUICKLY ACCUMULATE SEVERAL INCHES
OF RAINFALL AND SEE LOCALIZED FLOODING. RADAR TREND WILL BE
MONITORED CLOSELY THROUGH THE DAY FOR THIS POTENTIAL.
THINGS WILL TEND TO DRY OUT FOR A WHILE DURING THE LATER EVENING
HOURS TONIGHT BEFORE WE ONCE AGAIN SEE SHOWERS DEVELOPING OVER THE
EASTERN GULF AND MIGRATING TOWARD THE COAST IN THE PRE-DAWN HOURS.
MUCH OF THE AREA SHOULD BE ONCE AGAIN DODGING OFF AND ON SHOWERS
FOR SUNDAY WITH LIKELY POPS AS SOME POINT DURING THE DAY. SUNDAY
WILL BE THE DAY WHERE SOME POTENTIAL FOR DRIER AIR MAY TRY AND
SETTLE DOWN INTO THE NORTHERN NATURE COAST...AND MAY BE ABLE TO
LOWER POPS FURTHER FOR LEVY COUNTY AS CONFIDENCE IN THE SOUTHWARD
EXTENT OF DRIER AIR ALOFT INCREASES. SIMILAR TO TODAY...THE
HIGHEST RAIN CHANCES NEAR THE COAST WILL BE IN THE MORNING...WITH
THE HIGHEST RAIN CHANCES MIGRATING TO THE INLAND ZONES FOR THE
SECOND HALF OF THE DAY.
THE HIGHER COVERAGE OF SHOWERS AND CLOUDS WILL TEND TO KEEP
TEMPERATURES DOWN THIS WEEKEND. THOSE AREA THAT SEE SEVERAL ROUNDS
OF SHOWERS WILL LIKELY HOLD IN THE 80S. SO WILL SAY DAYTIME TEMPS
AT OR BELOW NORMAL THROUGH THE WEEKEND...WITH OVERNIGHT LOWS RIGHT
ABOUT WHERE THEY SHOULD BE FOR THE MIDDLE OF JULY.
FINAL NOTE...THE PERSISTENT SOUTHWESTERLY FLOW OVER THE EASTERN
GULF OF MEXICO HAS THE BUOYS OFFSHORE RUNNING AROUND 3 FEET EARLY
THIS MORNING. THESE VALUES HAVE BEEN SHOWN TO BE SUFFICIENT FOR AN
ENHANCED RIP CURRENT RISK DURING SOUTHWEST FLOW AND WILL ISSUE A
HIGH RISK OF RIP CURRENTS FOR BEACHES SOUTH OF TARPON SPRINGS
THROUGH THIS EVENING.
&&
.LONG TERM (SUNDAY NIGHT - FRIDAY)...
THE OVERALL PATTERN DURING THE LONG TERM PERIOD WILL NOT SEE
SIGNIFICANT CHANGE FROM DAY TO DAY...WITH A BROAD UPPER LEVEL RIDGE
CENTERED OVER THE GULF COAST...AND THE SURFACE SUBTROPICAL RIDGE
AXIS HANGING AROUND THE FLORIDA STRAITS. AS A RESULT...PERSISTENT
SOUTHWESTERLY TO WESTERLY LOW LEVEL FLOW LOOKS LIKELY TO REMAIN IN
CONTROL OF THE AREA THROUGH THE END OF NEXT WEEK. SOUTHWEST FLOW
TYPICALLY BRINGS SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE GULF
DURING THE OVERNIGHT AND MORNING HOURS AND MOVING INTO THE COAST
DURING THE MORNING AND AFTERNOON. AREAS FARTHER INLAND GENERALLY DO
NOT SEE THEIR HIGHEST STORM COVERAGE UNTIL LATE IN THE AFTERNOON AND
EARLY EVENING. THUNDERSTORMS WILL DIE DOWN A COUPLE HOURS AFTER
SUNSET...BEFORE THE PATTERN REPEATS WITH FRESH STORMS DEVELOPING
OVER THE GULF SHORTLY THEREAFTER. WITH THIS STAGNANT PATTERN...SOME
AREAS ALONG THE COAST CAN EASILY SEE PERIODS OF HEAVY RAINFALL
REPEATED MULTIPLE DAYS...INCREASING THE RISK OF FLOODING.
MOISTURE WILL BE READILY AVAILABLE...WITH MODEL PRECIPITABLE WATER
VALUES FORECAST TO REMAIN BETWEEN 1.75 AND 2.25 INCHES THROUGH THE
PERIOD. NOT ONLY WILL THIS ALLOW FOR THE WET PATTERN TO
CONTINUE...BUT WILL ALSO KEEP SKIES A BIT CLOUDIER THAN USUAL FOR
LATE JULY. AS A RESULT HIGH TEMPERATURES MAY HAVE A HARD TIME
REACHING GUIDANCE...ALTHOUGH A BRIEF BREAK IN THE CLOUDS DURING THE
AFTERNOON WILL BE SUFFICIENT TO LET TEMPERATURES SOAR. IN
GENERAL...HIGHS ARE EXPECTED TO RANGE FROM THE MID 80S TO AROUND 90
EACH DAY...WITH LOWS EACH MORNING GENERALLY IN THE 70S.
&&
.AVIATION...
GENERAL VFR CONDITIONS ARE OBSERVED ACROSS THE REGION EARLY THIS
MORNING UNDER A DECAYING CIRRUS SHIELD FROM THE CONVECTION ON
FRIDAY. NEW SHOWERS/STORMS ARE ALREADY FORMING AND PUSHING ONSHORE
FROM TAMPA DOWN TOWARD FORT MYERS. EXPECT THE TERMINALS TO BE IN
AND OUT OF SHOWERS/STORMS THROUGH THE DAY...WITH THE POTENTIAL FOR
THE MOST WIDESPREAD SHOWER ACTIVITY THIS MORNING OCCURRING FROM
KTPA/KPIE DOWN TO KSRQ.
&&
.MARINE...
THE FORECAST WATERS WILL REMAIN BETWEEN A WEAK TROUGH OF LOW
PRESSURE TO OUR NORTH...AND THE SUBTROPICAL SURFACE RIDGE TO OUR
SOUTH THROUGH THE EARLY PORTION OF NEXT WEEK. THIS PATTERN WILL
CONTINUE TO PROVIDE THE REGION WITH A LARGE SCALE SOUTHWEST FLOW.
ALTHOUGH WINDS AND SEAS ARE EXPECTED TO GENERALLY REMAIN BELOW
HEADLINE CRITERIA...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL CREATE LOCALLY HIGHER WIND GUSTS AND ROUGHER
SEAS.
&&
.FIRE WEATHER...
ABUNDANT LOW LEVEL MOISTURE AND ABOVE NORMAL RAIN CHANCES WILL
PREVENT ANY SIGNIFICANT FIRE WEATHER CONCERNS THROUGH THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS.
FOG POTENTIAL...NO SIGNIFICANT FOG IS ANTICIPATED THROUGH THE
WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 78 89 78 / 70 40 60 30
FMY 91 76 91 76 / 50 40 60 30
GIF 91 75 91 75 / 70 50 60 30
SRQ 87 78 88 77 / 70 50 60 30
BKV 89 74 90 74 / 70 40 60 30
SPG 88 79 89 79 / 70 40 60 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR COASTAL
CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA
LONG TERM...FLEMING
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
430 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN
PLAINS...ESPECIALLY IN THE NORTH PART OF THE FORECAST AREA.
EXPECT AN INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH
THIS UPPER FEATURE. THERE WILL ALSO BE SOME CONVERGENCE INTO THE
LEE-SIDE TROUGH IN THE FORECAST AREA. THE HRRR AND ARW DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTH PART OF THE FORECAST AREA
DURING THE MID TO LATE AFTERNOON WITH A SOUTHEASTWARD MOVEMENT.
THE HIGH-RESOLUTION MODELS HAD CONSIDERABLE COVERAGE IN THE NORTH
SECTION BUT LESS COVERAGE IN THE REST OF THE AREA DURING THE
AFTERNOON INTO THE EVENING. BASED ON THE INITIAL DRYNESS AND
LINGERING UPPER RIDGING THUNDERSTORM COVERAGE MAY REMAIN LIMITED.
WE FORECASTED THE HIGHER CHANCE IN THE NORTH PART BASED ON THE
HIGH-RESOLUTION MODELS AND MORE PRONOUNCED INFLUENCE OF THE MID-
LEVEL SHORTWAVE TROUGH. THE NAM INDICATED SURFACE-BASED LI/S -6 TO
-7 TODAY. THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE
SOUNDING INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF
THE THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE
BASED ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH MAY ALSO STALL
IN THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN SUPPORTS
ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS. THE
GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8 DEGREES
ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT FOG 09Z-14Z IMPROVING TO VFR BY 16Z.
WINDS WILL BE LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A
WEAK SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO WILL
LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
205 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN PLAINS.
EXPECT SOME INCREASE IN MOISTURE AND INSTABILITY. THERE WILL ALSO
BE SOME CONVERGENCE INTO THE LEE-SIDE TROUGH. THE HRRR DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTHWEST PART OF THE FORECAST AREA
EARLY THIS AFTERNOON WITH A SOUTHEASTWARD MOVEMENT INTO MUCH OF
THE REMAINING AREA DURING THE REST OF THE AFTERNOON. BASED ON THE
INITIAL DRYNESS AND LINGERING UPPER RIDGING THIS COVERAGE MAY BE
OVERDONE BUT WE DID LEAN TOWARD THE HIGHER GUIDANCE POPS OF AROUND
30 PERCENT. THE NAM INDICATED SURFACE-BASED LI/S -6 TO -7 TODAY.
THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE SOUNDING
INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF THE
THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE BASED
ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH MAY ALSO STALL
IN THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN SUPPORTS
ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS. THE
GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8 DEGREES
ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT FOG 09Z-14Z IMPROVING TO VFR BY 16Z.
WINDS WILL BE LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A
WEAK SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO WILL
LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
333 AM CDT SAT JUL 18 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
&&
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1150 PM CDT FRI JUL 17 2015
DEWPOINTS ARE QUITE HIGH ACROSS THE AREA AND WITH TEMPS FALLING TO
CLOSE TO DEWPOINTS AND WINDS BECOMING LIGHTER SOME...BELIEVE SOME
LIGHT FOG IS POSSIBLE OVERNIGHT. BELIEVE PIA/BMI/CMI WILL BE THE
SITES WHERE LIGHT FOG OF 4-5SM WILL BE PREDOMINATE. DEC AND SPI
WILL ONLY SEE A TEMPO GROUP AS TEMP/DWPT SPREADS ARE 6-8DEGREES
RIGHT NOW. OTHER THAN THE LIGHT FOG...WILL HAVE VFR CONDITIONS AT
ALL SITES REMAINDER OF THE PERIOD TOMORROW. WITH LOTS OF MOISTURE
AROUND...STILL THINK SOME CU IS POSSIBLE BUT SHOULD JUST BE
SCATTERED DURING THE DAY. CLOUDS WILL DISSIPATE DURING THE EVENING
BUT MODELS TRYING TO BRING IN SOME SCATTERED MID CLOUDS DURING
THE EVENING HOURS. WINDS WILL BE SOUTHERLY OVERNIGHT BUT THEN
BECOME SOUTHWESTERLY TOMORROW DURING THE DAY. DIRECTION LOOKS
VARIABLE TOMORROW EVENING BUT WIND SPEEDS SHOULD REMAIN 4-5KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
ILZ044>046-054>057-061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
442 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 116 AM EDT SAT JUL 18 2015
TODAY WILL BE VERY HOT AND HUMID ACROSS THE REGION. TEMPERATURES
WILL QUICKLY WARM INTO THE 80S THIS MORNING AND LOWER TO MIDDLE
90S THIS AFTERNOON. IT WILL BE VERY MUGGY AND THIS WILL MAKE IT
FEEL LIKE 100 TO 110 THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
A LATE AFTERNOON THUNDERSTORM BUT BETTER CHANCES TONIGHT AND
SUNDAY. IT WILL REMAIN WARM AND MUGGY TONIGHT WITH TEMPERATURES
STAYING IN THE 80S THIS EVENING AND LOWS ONLY IN THE 70S
OVERNIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 116 AM EDT SAT JUL 18 2015
CIRRUS BLOWOFF FROM UPSTREAM CONVECTION IN IL KEEPING KSBN CLOUDY
EARLY THIS MORNING AND THIS WILL INHIBIT BR DEVELOPMENT
INITIALLY. CLOUDS APPROACHING KFWA AS WELL. SATELLITE SHOWS SOME
THINNING BUT STILL OVC. ONCE SKIES PARTIALLY CLEAR SHOULD SEE
SOME MVFR BR DEVELOP WITH LIGHT WINDS. THIS WILL QUICKLY MIX AFTER
SUNRISE WITH SOUTHWEST WINDS 5 TO 10 KNOTS. A SLIGHT CHANCE FOR A
POP UP TSRA THIS AFTERNOON WITH HEAT BUT BUILDING RIDGE AND CAP
SHOULD KEEP THIS VERY ISOLATED AND TOO SMALL OF A CHANCE TO
MENTION IN TAFS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY FROM NOON EDT /11 AM CDT/ TODAY TO 9 PM EDT /8 PM
CDT/ THIS EVENING FOR INZ003>009-012>018-020-022>027-
032>034.
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ077>081.
OH...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
416 AM CDT SAT JUL 18 2015
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONVECTIVE TRENDS THROUGHOUT THE DAY WILL BE THE PRIMARY FORECAST
CHALLENGE ALONG WITH THE SUBSEQUENT TRICKLE DOWN EFFECT TO THE
REMAINDER FORECAST ELEMENTS. OVERNIGHT THUNDERSTORMS FROM NORTHERN
IOWA AND INTO SOUTHERN MINNESOTA HAVE PUSHED AN OUTFLOW BOUNDARY
THROUGH THE NORTHWEST HALF OF THE STATE AND HAS BROUGHT A SWITCH TO
NORTHWEST WINDS AND HAS DROPPED DEWPOINTS INTO THE LOW TO MID 60S.
VERY GUSTY WINDS HAVE MAINTAINED OVER FAR NORTHWEST IOWA THE PAST
SEVERAL HOURS...ESPECIALLY AROUND THE STORM LAKE AREA WHERE GUSTS
HAVE BEEN AROUND 50 MPH. THE LATEST OB FROM STORM LAKE WITH A WIND
GUST TO 74 MPH SEEMS RELATED TO A HEAT BURST AS THE TEMPERATURE
JUMPED 15 DEGREES WHILE DEWPOINTS DROPPED TO 52. WILL NEED TO
MONITOR TO SEE IF THIS PHENOMENON BECOMES MORE WIDESPREAD.
CONVECTIVE TRENDS THROUGH THE MID MORNING HOURS SHOULD GRADUALLY
DIMINISH EXCEPT FOR POSSIBLE STORMS OVER FAR SOUTHWEST IOWA.
CONVECTIVE DEBRIS WILL BE AROUND FOR AT LEAST A PORTION THIS MORNING
AND WILL HELP SLOW TEMPERATURES OVER AT LEAST CENTRAL AND NORTHERN
IOWA. DEWPOINTS SHOULD RECOVER BY LATE MORNING AND INTO THE
AFTERNOON WITH SOME POOLING OCCURRING ALONG AND AHEAD OF A BOUNDARY
MOVING INTO NORTHWEST IOWA THIS AFTERNOON. POSSIBLE DEWPOINTS COULD
JUMP INTO THE UPPER 70S ALONG THE BOUNDARY. THE BEST CHANCE FOR
THUNDERSTORMS WILL BE ALONG THE BOUNDARY BY THIS AFTERNOON AS IT
SINKS INTO CENTRAL IOWA.
WILL BE ISSUING A HEAT ADVISORY AGAIN FOR THE SOUTHERN THREE TIER OF
COUNTIES WHERE HEAT INDEX VALUES SHOULD AGAIN BE NEAR 105. CURRENT
FORECAST FOR DSM WOULD PLACE THE METRO IN A 3RD STRAIGHT WITH MOIST
TROPICAL PLUS AIR MASS. THE MAIN UNCERTAINTY FOR INTERSTATE 80 AND
NORTH IS CLOUD COVER THROUGH THE DAY WHICH VERY WELL COULD KEEP
TEMPERATURES COOLER THAN FRIDAY THOUGH DEWPOINTS WILL BE SIMILAR.
.LONG TERM /TONIGHT THROUGH FRIDAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONCERN FOR BEGINNING OF PERIOD WILL BE WITH PRECIPITATION CHANCES
AND THREAT FOR SEVERE WEATHER TONIGHT. MODELS...INCLUDING HIGH
RES...CONTINUE TO HOLD OFF ON PRECIPITATION DEVELOPMENT UNTIL
CLOSER TO 06Z...EXPECTING CAP TO REMAIN IN PLACE THROUGH AFTERNOON
AND EARLY EVENING BEFORE LLJ BEINGS TO INFLUENCE THE AREA.
HOWEVER...HAVE KEPT POPS IN THROUGH THE BEGINNING OF
PERIOD...EXPECTING ONGOING PRECIPITATION ACROSS THE AREA. BEST
CHANCES THROUGHOUT THE OVERNIGHT PERIOD WILL BE FOCUSED ALONG AND
SOUTH OF BOUNDARY...EXPECTED TO BE GENERALLY ACROSS SOUTHERN
PORTIONS OF THE CWA. WILL SEE A THREAT FOR HEAVY RAINFALL AGAIN IN
THIS AREA...WITH PWAT VALUES NEAR 1.9 INCHES AND GOOD WARM CLOUD
DEPTHS. MAY SEE POTENTIAL FOR FLASH FLOODING IN THE SOUTH
OVERNIGHT...BUT WILL HOLD OFF ON HEADLINES WITH PLACEMENT OF
PRECIPITATION STILL A BIT UNCERTAIN WITH SPEED OF BOUNDARY AND
POTENTIAL FOR REMNANTS OF OVERNIGHT CONVECTION TO INFLUENCE
CONVECTION. SHEAR WILL BE SOMEWHAT LACKING...BUT EXPECT
INSTABILITY TO BE STRONG ENOUGH TO OVERCOME LACKING SHEAR...MUCH
LIKE TONIGHT...TO WARRANT CHANCES FOR SEVERE THUNDERSTORMS EARLY
IN THE PERIOD.
BOUNDARY WILL PUSH SLOWLY SOUTH WITH PRECIPITATION CHANCES
LINGERING ALONG IT THROUGH SUNDAY MORNING IN THE SOUTH.
HOWEVER...MAY HAVE HELD ONTO CHANCES TOO LONG. WILL SEE A BREAK IN
HOT AND MUGGY CONDITIONS WITH A COOLER AIR MASS WORKING
IN...THOUGH TEMPS WILL STILL BE NEAR NORMAL....IN THE 80S. WAVE
WILL PUSH EAST THROUGH MOSTLY ZONAL FLOW FOR BEGINNING OF THE
WORK WEEK. HAVE INTRODUCED POPS FOR MONDAY WITH SYSTEM PUSHING
EAST...AND MODELS IN GOOD AGREEMENT ON TIMING AND PLACEMENT.
FORCING IS WEAK AND DO NOT HAVE HIGH CONFIDENCE. WEAK SURFACE HIGH
WILL KEEP CONDITIONS DRY UNTIL RIDGE BEGINS TO PUSH EAST FOR MID
WEEK. MODELS ARE NOT IN GOOD AGREEMENT WITH THIS SYSTEM. ECMWF IS
MUCH SLOWER...WITH BOTH ECMWF AND GEM KEEPING PRECIPITATION NORTH
AND SOUTH OF IOWA. GFS CONTINUES TO BRING SYSTEM THROUGH
IOWA...THOUGH BEST FORCING IS FURTHER SOUTH INTO MISSOURI.
THEREFORE...DO NOT HAVE HIGH CONFIDENCE AGAIN IN PRECIPITATION
CHANCES...BUT HAVE KEPT TRENDED TOWARDS THE GFS ATTM. WITH RIDGE
CONDITIONS WILL WARM FRIDAY...THOUGH WILL BE SHORT LIVED WITH
SECOND SYSTEM PUSHING EAST LATE FRIDAY...WITH ADDITIONAL
PRECIPITATION CHANCES INTO SATURDAY. AGAIN...NOT GOOD AGREEMENT ON
TIMING BETWEEN MODELS...AND HAVE BLENDED FOR NOW.
&&
.AVIATION...18/06Z
ISSUED AT 1203 AM CDT SAT JUL 18 2015
MCS OVER NEBRASKA WILL MOVE ACROSS IOWA OVERNIGHT...THOUGH
INSTABILITY REMAINS HIGH...LACK ORGANIZED SHEAR SHOULD RESULT IN
GRADUAL WEAKENING AS THE SYSTEM MOVES EAST NORTHEAST. HAVE ADDED
VCTS/VCSH BASED ON TIMING OF HRRR AND CURRENT TRENDS THROUGH 12Z.
OUTFLOW BOUNDARY TO LAY DOWN ACROSS CENTRAL/NORTHERN IOWA WHICH
WILL RESULT IN REDEVELOPMENT BETWEEN 18-21Z. EXACT TIMING AND
COVERAGE STILL IN QUESTION...SO CONFIDENCE LIMITED. IF STORMS HOLD
TOGETHER THROUGH 12Z...POSSIBLY SOME STRONG GUSTS NEAR KFOD AND
KMCW. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR ADAIR-ADAMS-APPANOOSE-CASS-CLARKE-DAVIS-DECATUR-LUCAS-
MADISON-MAHASKA-MARION-MONROE-RINGGOLD-TAYLOR-UNION-WAPELLO-
WARREN-WAYNE.
&&
$$
SHORT TERM...DONAVON
LONG TERM...AWB
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1207 AM CDT SAT JUL 18 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 346 PM CDT FRI JUL 17 2015
AHEAD OF AN ADVANCING FRONT IN THE PLAINS...TEMPERATURES THIS
AFTERNOON HAVE WARMED TO THE THE LOWER AND MID 90S. DEWPOINTS
HAVE DECREASED THIS AFTERNOON IN SEVERAL LOCATIONS WITH SLIGHTLY
DRIER AIR MIXING DOWN TO THE SURFACE. HEAT INDEX VALUES HAVE RANGED
NEAR 100 TO 105 WITH THE HIGHEST HEAT INDICES IN SOUTHERN IOWA.
UPPER TROUGH NOTED ON WATER VAPOR IMAGERY WILL DIG INTO THE NORTHERN
PLAINS TONIGHT. THUNDERSTORMS WILL CONTINUE TO DEVELOP OVERNIGHT IN
THE NORTHERN PLAINS ALONG ADVANCING FRONT. THUNDERSTORM CHANCES
INCREASE AFTER MIDNIGHT ACROSS NORTH CENTRAL IOWA THROUGH DAY BREAK
WITH THE ARRIVAL OF THE FRONT. INSTABILITY AND SHEAR SUPPORT A
MARGINAL RISK FOR A FEW STRONG TO SEVERE THUNDERSTORMS.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 346 PM CDT FRI JUL 17 2015
SATURDAY WILL BE HOT AND HUMID WITH SEVERE WEATHER POTENTIAL AT
TIMES...THEN THE FOLLOWING SEVERAL DAYS WILL SEE COOLER AND MOSTLY
DRY WEATHER. BY SUNRISE SATURDAY A POTENT 500 MB TROUGH WILL BE
SWINGING ACROSS NORTH DAKOTA AND SOUTHERN CANADA...PUSHING A
SURFACE COOL FRONT DOWN INTO FAR NORTHWESTERN IOWA. AS THE 500 MB
TROUGH MOVES RAPIDLY EASTWARD THE SURFACE FRONT WILL GRADUALLY SAG
INTO OUR AREA...LIKELY LYING ACROSS CENTRAL OR NORTHERN IOWA BY
AROUND 21Z. PRIOR TO THIS TIME...MODEST SOUTH SOUTHWEST SURFACE
FLOW AND MOISTURE POOLING SOUTH OF THE BOUNDARY WILL MAKE FOR
ANOTHER HOT AND VERY MUGGY DAY. THERE IS SOME QUESTION AS TO
WHETHER CONVECTION LATE TONIGHT ACROSS THE FAR NORTH WILL LEAVE
CONVECTIVE DEBRIS BEHIND BY MID MORNING SATURDAY...AND WHETHER IT
MAY PULL THE SYNOPTIC FRONT FURTHER SOUTH WITH IT THAN THE MODELS
ARE INDICATING. ALSO...THE ECMWF AND NAM HAVE PERSISTENTLY BEEN
DRIBBLING QPF AND MORE WIDESPREAD CLOUD COVER ACROSS CENTRAL IOWA
THROUGH THE DAY...WHICH WOULD OBVIOUSLY LIMIT DIURNAL HEATING.
HOWEVER...FORECAST SOUNDINGS INDICATE MOSTLY SUNNY SKIES AND A
CAPPING INVERSION FOR MOST OF THE DAY...WITH MOST HIGH RESOLUTION
MODELS SHOWING DRY CONDITIONS WHICH WILL PROMOTE MORE WARMING. FOR
NOW HAVE MAINTAINED A HIGH TEMPERATURE FORECAST CLOSE TO WHAT WAS
INHERITED...YIELDING PEAK HEAT INDEX VALUES IN THE 102 TO 104
RANGE ACROSS OUR SOUTH/SOUTHEAST COUNTIES. NO ADVISORY IS
THEREFORE BEING ISSUED AT THIS TIME...BUT THE OVERNIGHT SHIFT WILL
REASSESS SHORT TERM TRENDS AND MAKE A DETERMINATION AS TO WHETHER
OR NOT ONE WILL BE NECESSARY.
THERE WILL CLEARLY BE A VERY UNSTABLE AIRMASS AHEAD OF THE
APPROACHING FRONTAL BOUNDARY BY SATURDAY AFTERNOON. MOST OF THE
SUPPORTIVE DYNAMIC FORCING ASSOCIATED WITH THE UPPER LEVEL SYSTEM
WILL BE OFF TO OUR NORTHEAST AS THE 500 MB TROUGH DEPARTS...WHILE
ACROSS CENTRAL IOWA BULK SHEAR OF ABOUT 30 KNOTS IS FORECAST. THIS
SHOULD RESULT IN A THERMODYNAMICALLY DOMINANT SEVERE WEATHER
THREAT...WITH SCREAMING INSTABILITY AND THE BOUNDARY PROVIDING A
FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORMS DESPITE THE
RELATIVE LACK OF UPPER SUPPORT. THE CONVECTIVE OUTLOOK FROM SPC
DESCRIBES THIS THREAT WELL. IT IS ALSO WORTH NOTING THAT THE
GFS...NMM AND ARW MODELS ARE NOT DEVELOPING ANY CONVECTION ACROSS
OUR AREA UNTIL AFTER SUNSET SATURDAY NIGHT WHEN THE LOW LEVEL JET
DEVELOPS. GFS FORECAST SOUNDINGS SHOW THE REASON...WITH A WARM
NUBBIN DEVELOPING AS AN EML MOVES IN FROM THE SOUTHWEST SATURDAY
AFTERNOON AND JUST BARELY KEEPING US CAPPED. THUS WE ARE LEFT WITH
AN ALL OR NOTHING FORECAST FOR THUNDERSTORMS SATURDAY AFTERNOON
AND EVENING...LIKELY BOOM OR BUST AS WE WILL EITHER STAY CAPPED
AND SEE SUNNY SKIES OR BREAK THE CAP AND HAVE MULTIPLE SEVERE
THUNDERSTORMS. FOR NOW HAVE DELAYED THE HIGHER POPS UNTIL AROUND
00Z BUT MAINTAINED 50 TO 60 PERCENT CHANCES ACROSS THE AREA IN
DEFERENCE TO THE VERY REAL SEVERE WEATHER THREAT AND A DESIRE TO
NOT FLIP FLOP THE FORECAST...PLUS IT SEEMS MORE LIKELY THAN NOT
THAT THE CAP WILL BREAK AND THUNDERSTORMS WILL DEVELOP. BY
SATURDAY NIGHT THE FRONT WILL HAVE MOVED SOUTH...LIKELY AIDED BY
CONVECTION...INTO SOUTHERN IOWA AND DOWN TOWARD THE MISSOURI
BORDER. IT IS INCREASINGLY PROBABLE THAT AS THE NOCTURNAL LOW
LEVEL JET DEVELOPS AND FEEDS INTO THE BOUNDARY FROM THE SOUTHWEST
IT WILL PROMOTE REGENERATION OF THUNDERSTORMS WITH A HEAVY RAIN
AND FLOODING THREAT. HOWEVER...AT THIS TIME IT IS DIFFICULT TO
DETERMINE WHETHER THIS WILL OCCUR IN OUR AREA OR DOWN IN NORTHERN
MISSOURI. HAVE MAINTAINED LIKELY POPS IN OUR FAR SOUTH TO ACCOUNT
FOR THIS...WITH THE BOUNDARY AND STORMS LIKELY PUSHING DOWN OUT OF
OUR AREA BY LATE MORNING OR MIDDAY SUNDAY.
AFTER COOLER AND QUIET WEATHER SUNDAY NIGHT...IT APPEARS THAT A
COMPACT BUT ROBUST 500 MB SHORTWAVE WILL MOVE QUICKLY ACROSS THE
AREA ON MONDAY AND MONDAY NIGHT...AND MAY GENERATE ADDITIONAL
THUNDERSTORMS ACROSS THE AREA. WHILE THERE IS DECENT FORCING FOR
CONVECTION...INSTABILITY WILL BE QUITE LIMITED AND CONFIDENCE IS
NOT HIGH IN THUNDERSTORM CHANCES RESULTING IN JUST SLIGHT CHANCE
POPS ACROSS THE NORTHERN HALF. ANY STORMS THAT DO OCCUR WILL NOT
POSE MUCH OF A SEVERE WEATHER THREAT. BEHIND THE MONDAY SHORTWAVE
A REINFORCING SHOT OF COOL AIR WILL PUSH SOUTHWARD INTO THE REGION
AS A LARGE HIGH PRESSURE CENTER BUILDS DOWN THE NORTHERN HIGH
PLAINS. THIS WILL KEEP US COOL AND DRY THROUGH TUESDAY. THEREAFTER
A ROUGHLY ZONAL STEERING PATTERN WILL PERSIST...WITH SLOWLY
MODERATING TEMPERATURES AND PERIODIC THUNDERSTORM CHANCES THROUGH
THE REMAINDER OF NEXT WEEK.
&&
.AVIATION...18/06Z
ISSUED AT 1203 AM CDT SAT JUL 18 2015
MCS OVER NEBRASKA WILL MOVE ACROSS IOWA OVERNIGHT...THOUGH
INSTABILITY REMAINS HIGH...LACK ORGANIZED SHEAR SHOULD RESULT IN
GRADUAL WEAKENING AS THE SYSTEM MOVES EAST NORTHEAST. HAVE ADDED
VCTS/VCSH BASED ON TIMING OF HRRR AND CURRENT TRENDS THROUGH 12Z.
OUTFLOW BOUNDARY TO LAY DOWN ACROSS CENTRAL/NORTHERN IOWA WHICH
WILL RESULT IN REDEVELOPMENT BETWEEN 18-21Z. EXACT TIMING AND
COVERAGE STILL IN QUESTION...SO CONFIDENCE LIMITED. IF STORMS HOLD
TOGETHER THROUGH 12Z...POSSIBLY SOME STRONG GUSTS NEAR KFOD AND
KMCW. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ANGLE
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION
NWS PADUCAH KY
343 AM CDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THE CONSENSUS OF THE 00Z MODEL CYCLE IS THAT THE UPPER-LEVEL RIDGE
WILL HOLD STRONG ACROSS THE REGION THROUGH THE WEEKEND...AND THEN
IT WILL BE SUPPRESSED TO THE SOUTH/SOUTHWEST ON MONDAY. THE HEAT
ADVISORY LOOKS GOOD FOR TODAY AND SUNDAY. AT THIS TIME...DO NOT
SEE ANYTHING THAT WOULD INDICATE A NEED TO UPGRADE TO A WARNING.
THE MAIN CONCERN IS THE POTENTIAL FOR AT LEAST THE SOUTHERN HALF
OF THE AREA TO NEED A CONTINUATION INTO MONDAY. SINCE THE ENTIRE
AREA HAD 100+ HEAT INDICES YESTERDAY/FRIDAY...MONDAY WOULD BE THE
FOURTH CONSECUTIVE DAY OF 100+ HEAT INDICES WHICH WOULD SUPPORT A
CONTINUATION...EVEN IF ONLY 100-105 IS FORECAST. CONFIDENCE IN THE
MONDAY FORECAST IS QUITE LOW DUE TO A WEAK COLD FRONT AND
ASSOCIATED CONVECTION THAT IS EXPECTED TO BE DRAPED ACROSS THE
REGION. WILL LEAVE THE ADVISORY AS IS FOR NOW. AN UPDATED PRODUCT
WILL BE OUT BY 4 AM.
THE HRRR AND THE NMM AND ARW WRF RUNS ALL DEVELOP SOME ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS OVER ROUGHLY THE EASTERN HALF OF
THE FORECAST AREA FROM MIDDAY TODAY THROUGH THIS AFTERNOON. THIS
WOULD BE DIURNAL ACTIVITY IN A VERY WEAK FLOW REGIME...SO A PULSY
STRONG STORM WILL BE POSSIBLE WITH ISOLATED STRONG WINDS...BUT
ORGANIZED SEVERE WEATHER IS NOT EXPECTED.
POPS WILL BE INCREASING FROM THE NORTH THROUGH THE DAY SUNDAY AND
MUCH OF SUNDAY NIGHT...AS A COLD FRONT APPROACHES THE REGION. THE
CONSENSUS OF 00Z GUIDANCE BRINGS THE FRONT INTO THE AREA IN THE
LATE EVENING AND PUSHES IT THROUGH THE ENTIRE AREA BY 15Z MONDAY.
WILL HAVE POPS UP TO LOW-END LIKELY LEVELS WITH THE FRONT ALONG
THE I-64 CORRIDOR SUNDAY NIGHT. SUNDAY IS LIKELY TO BE DRY...BUT
20-30 POPS ARE FORECAST MAINLY IN THE NORTH JUST TO BE SAFE. POPS
MONDAY WILL BE IN THE CHANCE RANGE DUE TO UNCERTAINTIES IN
FRONTAL LOCATION AND DIURNAL HEATING.
THE FLOW INCREASES SIGNIFICANTLY LATE SUNDAY NIGHT INTO
MONDAY...SO STORMS IN THIS PERIOD WILL LIKELY BE MORE ORGANIZED. A
FEW SEVERE STORMS WITH DAMAGING WINDS WILL BE POSSIBLE. OF COURSE
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING WILL ACCOMPANY ANY
THUNDERSTORMS THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THIS EXTENDED FORECAST PACKAGE WOULD BE MORE FRUSTRATING TO DEAL
WITH CONSIDERING THE DAY TO DAY VARIATIONS OF THE DETERMINISTIC
GUIDANCE...PARTICULARLY THE GFS DETERMINISTIC MODEL. WITH THIS
PARTICULAR FORECAST PACKAGE...HAD TO FIGHT AGAINST THE EMPHASIS OF
THE DETERMINISTIC GFS GUIDANCE TO RETROGRADE THE SOUTHERN U.S. RIDGE
LATER IN THE WEEK TO ALLOW FOR FASTER AND SLIGHTLY WETTER FLOW AHEAD
OF THE RIDGE.
LOOKING AT THE WESTERN REGION FORECASTER CONFIDENCE TOOLKIT...THE
ENSEMBLE GUIDANCE...EVEN THE GFS ENSEMBLE CONTINUE TO HINT THAT THE
SOUTHERN U.S. RIDGE WILL REMAIN DOMINANT AND WILL NOT RETROGRADE
LATTER IN THE WEEK. CIPS AND OTHER ANALYSIS/ANALOG/ENSEMBLE PLOTS
CONTINUE TO HINT THAT NEXT WEEKEND /JULY 25-26/ WILL BE THE WARMEST
AND DRIEST SO FAR THIS SUMMER. I WOULD NOT BE SURPRISED IF A SPOT OR
TWO IN SOUTHEAST MISSOURI REACHES 98-100...ESPECIALLY BY NEXT
SATURDAY OR SUNDAY.
WITH THE ADJUSTMENT OF THE GRIDDED FORECAST TOWARD THE WARMER AND
DRIER SOLUTION...ADJUSTED DEWPOINTS DOWNWARD 1-2 DEGREES AND LOWERED
OPAQUE CLOUD COVER INTO THE PARTLY CLOUDY CATEGORY VERSUS MOSTLY
CLOUDY. ALL OF THESE CHANGES WILL SUGGEST AND SUPPORT GREATER
EVAPORATION AND INSOLATION...LEADING TO A LONGER DRY SPELL FOR THE
REGION.
FROM A HEAT STANDPOINT...IT LOOKS LIKE NEXT SATURDAY WILL BRING A
RETURN TO A HEAT ADVISORY (OR HIGHER) TO SOUTHEAST MISSOURI...WITH
HEAT INDEX VALUES NEAR 110 WIDESPREAD ON THAT DAY. SUNDAY DOES NOT
LOOK MUCH BETTER.
THERE REMAINS SOME CHALLENGE AS TO THE IMPACT AND COVERAGE OF
PRECIPITATION TUESDAY THROUGH THURSDAY OF NEXT WEEK.
HOWEVER...DEPENDING ON THE INTERPLAY BETWEEN THE RIDGE AND THE FAST
ZONAL FLOW JUST NORTH OF THE RIDGE...THE WFO PAH FORECAST AREA MAY
STILL SEE SOME CONVECTIVE ACTIVITY THROUGH THURSDAY.
&&
.AVIATION...
ISSUED AT 615 PM CDT FRI JUL 17 2015
HIGH PRESSURE AT THE SURFACE AND ALOFT WILL PRODUCE DRY CONDITIONS
FOR ALL SITES THROUGH THE PERIOD. ANY CLOUD COVER THAT MAY OCCUR
FROM TIME TO TIME WILL BE VFR. WINDS WILL CONTINUE OUT OF THE SOUTH
SOUTHWEST TO SOUTHWEST GENERALLY AOB 10 KNOTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
ILZ075>078-080>094.
MO...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
MOZ076-086-087-100-107>112-114.
IN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
INZ081-082-085>088.
KY...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...SMITH
AVIATION...DB
AREA FORECAST DISCUSSION
NWS JACKSON KY
313 AM EDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 130 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS WILL PUSH ON THROUGH OVERNIGHT WITH
SOME SHARP REDUCTIONS IN VISIBILITIES IN THE STRONGER SHOWERS AND
STORMS. IT LOOKS LIKE SHOWERS AND STORMS WILL STAY JUST NORTH OF
KSME AND KLOZ...BUT CLOSE ENOUGH TO LEAVE IN A VCTS.
HOWEVER...KJKL AND KSJS WILL BE IN THE MAIN PATH OF THIS
COMPLEX...SO BEST CHANCES FOR REDUCED VISIBILITIES. WHILE SOME
SHOWERS WILL PERSIST AT KSYM...CONDITIONS SHOULD REMAIN VFR.
SHOWERS AND STORMS WILL MOVE ON OUT BY DAYBREAK...LEAVING BEHIND
VFR CONDITIONS. HOWEVER...THE THREAT OF A ROGUE SHOWER OR STORM
WILL CONTINUE...BUT CONFIDENCE IS LOW ENOUGH TO LEAVE OUT OF THE
TAFS PRESENTLY. WILL HOLD WITH A VFR FORECAST FOR THE DAYLIGHT
PORTION OF THE TAF.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
250 AM EDT SAT JUL 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
LONG TERM DISCUSSION WILL FOLLOW SHORTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 130 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS WILL PUSH ON THROUGH OVERNIGHT WITH
SOME SHARP REDUCTIONS IN VISIBILITIES IN THE STRONGER SHOWERS AND
STORMS. IT LOOKS LIKE SHOWERS AND STORMS WILL STAY JUST NORTH OF
KSME AND KLOZ...BUT CLOSE ENOUGH TO LEAVE IN A VCTS.
HOWEVER...KJKL AND KSJS WILL BE IN THE MAIN PATH OF THIS
COMPLEX...SO BEST CHANCES FOR REDUCED VISIBILITIES. WHILE SOME
SHOWERS WILL PERSIST AT KSYM...CONDITIONS SHOULD REMAIN VFR.
SHOWERS AND STORMS WILL MOVE ON OUT BY DAYBREAK...LEAVING BEHIND
VFR CONDITIONS. HOWEVER...THE THREAT OF A ROGUE SHOWER OR STORM
WILL CONTINUE...BUT CONFIDENCE IS LOW ENOUGH TO LEAVE OUT OF THE
TAFS PRESENTLY. WILL HOLD WITH A VFR FORECAST FOR THE DAYLIGHT
PORTION OF THE TAF.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
155 AM EDT SAT JUL 18 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EDT FRI JUL 17 2015
A FEW SHOWERS AND STORMS WILL BE POSSIBLE LATE THIS AFTERNOON SOUTH
AND EAST OF INTERSTATE 69. THESE WILL MOVE OUT QUICKLY BY EARLY
EVENING.
HEAT AND HUMIDITY WILL BUILD IN ACROSS THE AREA THROUGH THE DAY ON
SATURDAY. TEMPERATURES ARE EXPECTED TO WARM INTO THE LOWER 90S SOUTH
WHILE HEAT INDICES WILL BE AROUND 100 DEGREES. THERE IS A SLIGHT
CHANCE OF A SHOWER OR STORM SATURDAY. A BETTER CHANCE OF STORMS WILL
COME IN LATER SATURDAY NIGHT AND SUNDAY AS A COLD FRONT PUSHES
THROUGH THE AREA. COOLER AND SOMEWHAT DRIER AIR WILL FILTER IN FOR
THE BEGINNING OF THE WORK WEEK NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI JUL 17 2015
OUR BIGGEST CONCERNS IN THE FCST THROUGH SUN NIGHT ARE THE STORM
CHCS THROUGH THE PERIOD...ALONG WITH THE HEAT POTENTIAL FOR SAT. A
HEAT ADVISORY WILL BE ISSUED WITH THIS FCST PACKAGE FOR THE SRN HALF
OF THE CWFA.
WE HAVE A FEW SHOWERS/STORMS THAT WILL REMAIN POSSIBLE LATE THIS
AFTERNOON MAINLY SOUTH AND EAST OF INTERSTATE 69. WE ARE WATCHING AN
ENHANCED CU FIELD THAT STRETCHES ROUGHLY FROM MIDLAND COUNTY TO EAST
OF SOUTH HAVEN. THIS IS AHEAD OF A WEAK TROUGH DROPPING SOUTHEAST
THROUGH THE AREA ALONG WITH SOME ENHANCEMENT OCCURRING DUE TO THE
WRLY FLOW OFF OF COOLER LAKE MICHIGAN. SOUTH OF THIS LINE...MU CAPES
ARE AROUND 3000 J/KG. DEEP LAYER SHEAR STILL LOOKS TO BE LACKING A
BIT...BUT WE COULD SEE SOME STRONGER PULSE TYPE STORMS POSSIBLE
BEFORE THEY MOVE OUT EARLY THIS EVENING.
THE NEXT LOW CHC OF SOME SHOWERS AND MAYBE A STORM WOULD COME ON SAT
MORNING...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA. A COMPLEX OF
STORMS IS FCST TO DEVELOP/EXPAND ACROSS MN THIS EVENING AHEAD OF A
DEVELOPING LLJ/MOISTURE TRANSPORT THERE. THERE ARE SOME MODELS LIKE
THE HRRR AND NSSL WRF THAT BRING THIS E/SE AFTER DAYBREAK SAT
MORNING. THIS SEEMS PLAUSIBLE WITH DEEP LAYER THICKNESSES EXPECTED
TO BE ORIENTED THIS WAY AND A DEEP LAYER INSTABILITY GRADIENT VERY
SIMILAR. THE LLJ WEAKENS BY THE TIME IT GETS HERE...SO WE EXPECT IT
WOULD BE IN THE DECAYING STAGES IF IT MAKES IT HERE.
ONCE THE DECAYING LINE OF SHOWERS/STORMS IS OUT OF THE PICTURE...THE
HEAT WILL BE THE STORY. ASSUMING THERE IS NOT A PROBLEM WITH
CLEARING CLOUDS OUT SAT MORNING AND SOME POSSIBLE FOG...WE SHOULD
WARM UP QUICKLY AND DEW POINTS WILL REMAIN GENERALLY IN THE LOWER
70S. WE ARE LOOKING AT HEAT INDICES AROUND 100F ROUGHLY OVER THE SRN
HALF OF THE CWFA AWAY FROM THE IMMEDIATE LAKESHORE. WE CAN NOT RULE
OUT A POP UP STORM SAT AFTERNOON WITH A POSSIBLE OUTFLOW BOUNDARY
FLOATING AROUND AND POSSIBLE MU CAPES OF 5000 J/KG. WE LOOK VERY
CAPPED...SO THE CHCS OF A STORM ARE LIMITED TO ABOUT 10-20 PCT.
ANYTHING THAT POPS WOULD HAVE THE POTENTIAL TO BECOME SEVERE WITH
THE EXTREME INSTABILITY AVAILABLE...EVEN WITH WEAK SHEAR VALUES
AROUND 20 KNOTS.
THE BETTER CHC FOR STORMS WILL ROLL IN SAT NIGHT AND THEN MOVE OUT
LATER ON SUN. THE BEST MOISTURE TRANSPORT AND LLJ AHEAD OF THE FRONT
WILL DRIFT IN FROM THE NW SAT NIGHT. THIS WILL BRING SOME HIGHER
CHCS ACROSS THE NW PORTION OF THE AREA. THIS WILL BE ON THE EDGE OF
THE CAP AND WILL FOLLOW THE EDGE OF STRONG INSTABILITY. LARGE HAIL
WILL BE POSSIBLE...AND IT WILL HAVE THE POTENTIAL TO HAVE SOME
DAMAGING WINDS AND BE BETTER ORGANIZED AS A BETTER WIND FIELD ALOFT
MOVES IN. ADDITIONAL STORMS FIRING ALONG THE FRONT WILL HAVE THAT
POTENTIAL THEN ON SUN IF THE FRONT IS STILL IN THE AREA. IF THE
FRONT CLEARS THE CWFA SOONER RATHER THAN LATER ON SUN...THE SEVERE
THREAT WILL BE LOWER.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI JUL 17 2015
IN GENERAL NEXT WEEK LOOKS VERY SUMMER LIKE WITH HIGHS MAINLY IN THE
LOWER TO MID 80S AND LOWS IN THE MID 50S TO MID 60S. CHANCES FOR
SHOWERS AND THUNDERSTORMS LOOK RELATIVELY LOW.
CONFIDENCE IS HIGH THAT MONDAY WILL BE SUNNY AND LESS HUMID. A WEAK
COLD FRONT IS SHOWN TO DROP SOUTH THROUGH THE STATE ON TUESDAY
ALTHOUGH SOME TIMING DIFFERENCE EXISTS WITH THE ECMWF MUCH QUICKER
THAN THE GFS. EITHER WAY THE COVERAGE OF CONVECTION IS EXPECTED TO
BE LIMITED IN SW LWR MI WITH BETTER POPS IN ERN LWR MI WHERE BETTER
CONVERGENCE IS PROGGED.
HIGH PRESSURE IS EXPECTED TO DOMINATE ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AS WELL. THE ECMWF IS A BIT MORE BULLISH THAN THE GFS WITH
THE RETURN OF WAA RELATED PRECIP...AIDED BY A SHORTWAVE ALOFT...
ALREADY SHOWING QPF ON THURSDAY. THE GFS MEANWHILE WANTS TO HOLD THE
SFC RIDGE AND DRY AIR THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 153 AM EDT SAT JUL 18 2015
GIVEN HIGH DEWPOINTS AND LIGHT WIND...WE/LL SEE FOG DEVELOP PRIOR
TO SUNRISE. MVFR VSBYS EXPECTED. ALTHOUGH NOT IN THE TAFS...WE
COULD ALSO SEE SOME PCPN THIS MORNING AS A THUNDERSTORM COMPLEX
OVER MINNESOTA MOVES EAST. THINKING IS THAT IT WILL DISSIPATE
SOMEWHAT AND BE MAINLY NORTH OF THE TAF SITES...BUT NOT DEFINITE
ABOUT THAT. MORE SHOWERS/STORMS POSSIBLE THIS AFTERNOON AND
EVENING AS A COLD FRONT MOVES EAST TOWARD LOWER MICHIGAN.
&&
.MARINE...
ISSUED AT 330 PM EDT FRI JUL 17 2015
WE HAVE EXPANDED THE MARINE DENSE FOG ADVISORY THROUGH SAT NIGHT FOR
THE TIME BEING. VISIBLE SATELLITE IMAGERY THIS AFTERNOON COMBINED
WITH WEB CAMS ALONG THE SHORE SHOW FAIRLY DENSE FOG AT MOST
LOCATIONS. CONDITIONS ARE NOT QUITE AS BAD AT SOUTH HAVEN...BUT IT
HAS EXPANDED SOUTH THIS AFTERNOON AS WINDS HAVE GONE WRLY. EVEN
HIGHER DEW POINTS MOVING IN WITH DIMINISHING WINDS WILL KEEP THE
POTENTIAL HIGH THROUGH AT LEAST SAT NIGHT.
WINDS DO NOT LOOK TO BE A PROBLEM UNTIL AT LEAST SATURDAY NIGHT IF
NOT SUNDAY. A CORE OF WINDS ALOFT AHEAD OF THE INCOMING COLD FRONT
COULD RAMP WINDS UP SAT NIGHT...HOWEVER THIS IS ALWAYS TRICKY WITH
WARMER AIR OVER THE COOLER WATERS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ056>059-064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...04
HYDROLOGY...CAS
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
1230 AM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 659 PM CDT FRI JUL 17 2015
HAVE DELAYED THE ONSET OF SHOWERS AND STORMS CLOSER TO MIDNIGHT
OVER THE WESTERN THIRD OF THE FORECAST AREA PER THE LATEST HRRR.
AS SUCH...DELAYED OVER THE REST OF THE REGION TO AFTER MIDNIGHT.
OTHER MINOR ADJUSTMENTS HAVE BEEN MADE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
FORECAST FOCUS IN THE SHORT TERM WILL BE ON STORM
CHANCES...STRENGTH...AND POTENTIAL FOR HEAVY RAIN.
A FRONTAL BOUNDARY STRETCHED FROM SOUTHERN MANITOBA THROUGH THE
RED RIVER VALLEY INTO SOUTH DAKOTA AS OF LATE AFTERNOON AND WILL
MOVE EAST OVERNIGHT MOVING INTO CENTRAL MINNESOTA BY 12Z
SATURDAY...THEN JUST CLEARING OUR EASTERN CWA BY 00Z SUN. WATER
VAPOR IMAGERY SHOWED AN UPPER LOW OVER SOUTHERN SK...AND THIS IS
FORECAST TO TRACK ALONG AND JUST NORTH OF THE INTERNATIONAL
BORDER...LAGGING THE FRONT.
SHOWERS/STORMS WILL CONTINUE TO DEVELOP ALONG THE FRONT THIS
AFTERNOON INTO TONIGHT MOVING INTO THE NORTHLAND. THE MODELS WERE
OFFERING VARIOUS SOLUTIONS AS TO HOW FAR EAST THE RAIN WILL MAKE
IT TONIGHT...AND WE BLENDED THE HRRR WITH THE GFS/NAM/ECMWF.
MLCAPE VALUES HAVE BEEN CLIMBING THIS AFTERNOON AND WERE FROM
500 OVER THE ARROWHEAD TO 1500 J/KG ACROSS OUR SOUTHERN ZONES AS
OF THE 19Z SPC MESOANALYSIS. THE HIGHEST CAPE AND NOSE OF THE LLJ
WILL REMAIN SOUTH OF OUR CWA TONIGHT AND THE HRRR SEEMS TO HAVE A
GOOD HANDLE ON DEVELOPING STRONG TO SEVERE STORMS NEAR OR JUST
SOUTH OF OUR CWA THIS EVENING. A STRONG TO SEVERE STORM WILL
REMAIN POSSIBLE OVERNIGHT OVER OUR AREA...BUT CHANCES WILL BE
HIGHEST SOUTH. WE HAVE BEEN QUITE CONCERNED ABOUT ANOTHER ROUND OF
HEAVY RAIN TONIGHT IN AREAS THAT RECEIVED HEAVY RAIN FRIDAY/FRIDAY
EVENING...MAINLY FROM NORTHERN CASS COUNTY NNE TO NORTHERN SAINT
LOUIS COUNTY. PWAT VALUES RISE TO 1.5 TO 1.7 INCHES AGAIN
TONIGHT. WE THOUGHT ABOUT ISSUING A FLASH FLOOD WATCH...BUT IT
DOES NOT APPEAR THAT TRAINING THUNDERSTORMS WILL BE AS BIG A
THREAT AS LAST NIGHT. THE HRRR/NMM/ARW HIGH RES SOLUTIONS SUPPORT
A MORE PROGRESSIVE NATURE TO THE STORMS WITH THE STRONGEST STORMS
SOUTH. WE WILL HAVE TO MONITOR CLOSELY AS 2 TO 4 INCHES OF RAIN
FELL FROM NORTHERN CASS TO KOOCHICHING COUNTIES YESTERDAY INTO THE
EVENING. THE EVENING SHIFT WILL HAVE TO MONITOR STORM
MODE/STRENGTH AND MAY HAVE TO ISSUE HEADLINES IF NEEDED.
SHOWERS/STORMS SHOULD BE ONGOING IN SPOTS SATURDAY MORNING...THEN
MAY WEAKEN OR MOVE OFF LATE MORNING. ADDITIONAL STORMS WILL
DEVELOP ALONG THE FRONT SATURDAY AFTERNOON AND THEY COULD BE
SEVERE...MAINLY OVER PORTIONS OF NORTHWEST WISCONSIN WHERE A MOIST
UNSTABLE AIRMASS WILL BE IN PLACE. DEWPOINTS AHEAD OF THE FRONT
WILL BE FROM 65 TO AROUND 70...THEN DROP BEHIND IT. MOST AREAS
SHOULD RISE INTO THE UPPER 70S TO MID 80S ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI JUL 17 2015
SATURDAY NIGHT...A COLD FRONT WILL FINISH MOVING THROUGH THE
NORTHLAND IN THE LATE EVENING...WHILE AN UPPER LEVEL TROUGH OVER
MANITOBA/ONTARIO LIFTS THROUGH THE REGION. THERE COULD BE LINGERING
SHOWERS AND STORMS IN NW WISCONSIN AND FAR NORTHERN MINNESOTA BEFORE
MIDNIGHT.
SUNDAY...WARMER AIR WILL BEGIN TO FILTER BACK INTO THE NORTHLAND
WITH THE WESTERLY FLOW. THE NAM12 SOUNDINGS INDICATE BREEZY
CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. MOST OF THE
MODELS ARE DRY...BUT THE SREF IS INDICATING LOW PCPN CHANCES...SO
ADDED THE SREF TO THE MODEL BLEND TO GIVE LOW CHANCES OF SHOWERS AND
STORMS OVER NORTHERN MINNESOTA.
MONDAY...THE MODELS ARE NOT IN GOOD AGREEMENT...BUT GENERALLY
INDICATE ANOTHER COLD FRONT WILL MOVE FROM NW TO SE THROUGH THE
FORECAST AREA. THE ECMWF IS ABOUT 12 TO 18 HOURS FASTER THAN THE GFS
AND GEM. THE TIMING OF THE FRONT HAS IMPLICATIONS ON TEMPERATURES
AND PCPN CHANCES. SINCE THE ECMWF FRONT PASSAGE IS DURING THE WEE
HOURS OF MONDAY MORNING...IT DOES NOT HAVE THE INSTABILITY AND PCPN
THAT THE GFS AND GEM ARE INDICATING WITH THE AFTERNOON/EVENING
PASSAGE TIMEFRAME. THE GFS HAS MUCH HOTTER TEMPERATURES FOR
MONDAY...PARTLY SINCE ITS COLD FRONT PASSAGE IS NOT UNTIL MONDAY
NIGHT. USED A BLEND OF THE GFS/GEM/ECMWF/SREF.
TUESDAY...HIGH PRESSURE WILL LIKELY KEEP THE NORTHLAND DRY AND A BIT
COOLER FOR THIS DAY. TEMPERATURES WILL LIKELY BE SEASONAL NORMALS
WITH HIGHS IN THE UPPER 70S.
WEDNESDAY AND THURSDAY...THE MODELS ARE IN POOR AGREEMENT...BUT
GENERALLY SUGGEST A WARM AND HUMID SOUTHERLY LOW LEVEL FLOW PATTERN
SETTING UP DURING THIS TIME. THIS COULD BEGIN TO BRING WARMER AND
UNSTABLE AIR INTO THE REGION. SHOWERS AND THUNDERSTORMS ARE
POSSIBLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1229 AM CDT SAT JUL 18 2015
THUNDERSTORMS APPEAR TO BE SOUTH OF THE TERMINALS THROUGH THE
FORECAST AND HAVE ADJUSTED ACCORDINGLY. HAVE A MENTION OF LIGHT
RAIN/VCSH HOWEVER AT ALL TERMINALS. LOOKING FOR VFR THROUGH THE
FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 60 81 62 83 / 10 10 0 10
INL 57 78 60 79 / 10 20 10 20
BRD 59 84 62 85 / 0 10 0 10
HYR 60 81 60 83 / 0 10 0 20
ASX 61 81 61 84 / 10 10 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
410 AM CDT SAT JUL 18 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 410 AM CDT SAT JUL 18 2015
FIRST FORECAST CHALLENGE FOR TODAY IS POPS. SEEING EXPANDING
COVERAGE IN ISOLATED TO WIDELY SCATTERED CONVECTION OVER WEST
CENTRAL/NORTHWEST MISSOURI AT THIS TIME. HRRR SEEMS TO BE HANDLING
THIS WAA PRECIP THE BEST AT THE MOMENT, BUT LATEST RUNS OF THE RAP
DO SEEM TO BE CATCHING UP. FORECAST SOUNDINGS SHOW THE PROVERBIAL
CAP OF FORGED STEEL DEVELOPING...SO SURFACE BASED CONVECTION LOOKS
PRETTY UNLIKELY. MY GUT FEELING IS THAT THE HRRR IS TOO AGGRESSIVE
IN BOTH AREAL COVERAGE AND LONGEVITY IN KEEPING PRECIP GOING THROUGH
LATE MORNING AND EARLY AFTERNOON...AND THE RAP MAY NOT BE AGGRESSIVE
ENOUGH, SO I WENT SOMEWHERE IN BETWEEN INCREASING POPS TO SLIGHT
CHANCE ACROSS CENTRAL AND NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS.
SECOND CHALLENGE IS TEMPERATURES...AND THE HEAT ADVISORY WHICH IS
ALREADY IN EFFECT. OBVIOUSLY, PRECIPITATION AND CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TODAY. IF THE HRRR IS MORE RIGHT
THAN WRONG TODAY, THEN ITS UNLIKELY THAT TEMPERATURES WILL HIT THE
MID AND UPPER 90S AS PER THE CURRENT FORECAST. STUCK WITH THE
WARMER FORECAST AND USED A BLEND OF GUIDANCE FOR HIGHS...LEANING
TOWARD A MIX-DOWN OF 850MB GFS TEMPERATURES. NO CHANGE TO THE HEAT
HEADLINES IS ANTICIPATED AT THIS TIME WITH THE CAVEAT THAT THIS
MORNING`S PRECIP DOESN`T DEVELOP INTO SOMETHING MORE SUBSTANTIAL.
CARNEY
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT JUL 18 2015
HEAT REMAINS THE PRIMARY FORECAST CONCERN THRU SUNDAY...AND PERHAPS
INTO MONDAY.
UPPER LEVEL RIDGE DOMINATING THE SOUTHERN CONUS WILL CONTINUE TO
COMMAND A STRONG INFLUENCE INTO OUR REGION INTO SUNDAY...BUT IS
EXPECTED TO BEGIN TO BREAKDOWN A BIT FROM THE NORTH AS THE FIRST IN
A SERIES OF UPPER LEVEL DISTURBANCES PASS THRU. AT THE SURFACE...
THIS WILL EQUATE TO OUR REGION REMAINING IN A S-SW FLOW INTO
SUNDAY...WITH A COLD FRONT DROPPING DOWN MAINLY FROM THE AFTERNOON
HOURS ONWARD. WHILE THIS FRONT IS EXPECTED TO SETTLE ACROSS
SOUTHERN MO AND FAR SOUTHERN IL BY SUNDAY NIGHT...THERE IS
INCREASING EVIDENCE IN THE MODELS THAT THIS FIRST FRONT WILL
DISSOLVE SUNDAY NIGHT WITH A SW FLOW RESUMING ALREADY ON MONDAY IN
TIME FOR ANOTHER FRONT TO DROP DOWN DURING THE AFTERNOON.
REFERENCE SHORT-TERM DISCUSSION ON HEAT FORECAST FOR TODAY.
THE DANGEROUS HEAT AND HUMIDITY IS STILL EXPECTED TO CONTINUE INTO
SUNDAY FOR MUCH OF OUR REGION...ENOUGH TO WARRANT MAINTAINING A HEAT
ADVISORY...ALTHOUGH WITH INCREASING UNCERTAINTY ON ITS NORTHERN
PERIPHERY...AS WHAT LOOKS TO BE A NOCTURNAL CONVECTIVE EVENT WILL
TAKE HOLD FOR LATE TONIGHT AND CARRY INTO SUNDAY MORNING FOR AREAS
MAINLY NORTH OF I-70. THIS WILL BRING WITH IT THE ASSOCIATED DEBRIS
CLOUD THAT WILL PROBABLY LINGER INTO SUNDAY AFTERNOON AND FURTHER
COMPLICATE TEMPS AND HEAT INDEX VALUES WITH A DECENT GRADIENT
SOMEWHERE IN THE VICINITY OF I-70... ALL THE WHILE WITH THE SURFACE
COLD FRONT DROPPING INTO THIS AREA AS WELL DURING THE AFTERNOON.
SOME AREAS MAY EVENTUALLY NEED TO BE LOPPED OFF FROM THE HEAT
ADVISORY BUT THE CONFIDENCE FOR DOING IT THIS PACKAGE IS NOT THERE.
TO FURTHER COMPLICATE THINGS...THE POSSIBLE DISSOLUTION OF THE FRONT
SUNDAY NIGHT AND RETURN OF THE HEAT ALREADY BY MONDAY MAY
NECESSITATE AN EXTENSION OF THE HEAT ADVISORY FOR PARTS OF OUR AREA
INTO MONDAY. BUT AGAIN...THE CONFIDENCE FOR DOING IT WITH THIS
PACKAGE IS SIMPLY NOT THERE AT THIS TIME.
FOCUS THEN SHIFTS TO RAIN CHCS AND SEVERE POTENTIAL FOR EARLY NEXT
WEEK.
THE NOCTURNAL CONVECTIVE EVENT FOR AREAS NORTH OF I-70 WILL HAVE
POTENTIAL FOR SEVERE STORMS PERHAPS ALONG THE FAR NORTHERN CWA FOR A
WINDOW OF TIME THIS EVENING. SEVERE STORM POTENTIAL ON SUNDAY WILL
BE HIGHLY DEPENDENT ON EXACTLY WHAT HAPPENS THE NIGHT BEFORE BUT
ENOUGH INSTABILITY SHOULD BE PRESENT FOR AT LEAST AN ISOLATED SEVERE
STORM THREAT. MORE OR LESS THE SAME ON MONDAY WITH A NEW FRONT AND
SIMILAR INSTABILITY IN PLACE.
THE LINGERING FRONTAL BOUNDARY THRU TUESDAY WILL KEEP RAIN CHANCES
GOING. WE MAY SEE A BRIEF REPRIEVE LATE TUESDAY THRU WEDNESDAY WITH
INFLUENCE OF SURFACE HI PRESSURE BUT A WARM FRONT LATE WEDNESDAY
NIGHT INTO THURSDAY WILL ALLOW FOR THE RETURN OF RAIN CHANCES INTO
THE AREA.
ANOTHER ROUND OF HEAT REMAINS ON TAP FOR PERHAPS AS EARLY AS
THURSDAY AFTERNOON...BUT MODEL CONSENSUS AGREES TO DELAY A DAY INTO
FRIDAY AND NEXT WEEKEND.
TES
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1157 PM CDT FRI JUL 17 2015
VFR AND DRY THRU THE TAF PERIOD. HAVE ADDED LLWS FOR COU AND UIN
OVERNIGHT. OTHERWISE...WINDS WILL BE SLY AND BECOME SWLY SHORTLY
AFTER SUNRISE AS MIXING OCCURS. COU AND UIN MAY SEE GUSTS TO
AROUND 20 KTS DURING THE AFTERNOON.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR CRAWFORD MO-
IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KNOX MO-LEWIS MO-
MARION MO-MONROE MO-PIKE MO-RALLS MO-SHELBY MO.
IL...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR BOND IL-
CLINTON IL-FAYETTE IL-MARION IL-MONTGOMERY IL-RANDOLPH IL-
WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR CALHOUN IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-ST. CLAIR IL.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ADAMS IL-BROWN IL-
PIKE IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1159 PM CDT FRI JUL 17 2015
.UPDATE:
ISSUED AT 931 PM CDT FRI JUL 17 2015
THUNDERSTORMS HAVE MOVED EAST OUT OF THE AREA AND RAP MASS FIELDS
NOT SHOWING ANY LIKELIHOOD OF REDEVELOPMENT OVERNIGHT. HAVE KEPT
WITH THE DRY FORECAST. STILL LOOKS LIKE A WARM AND MUGGY NIGHT AS
CURRENT DEWPOINTS ARE IN THE MID-UPPER 70S IN MOST AREAS WITH
CURRENT TEMPERATURES STILL IN THE 80S.
BRITT
&&
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 239 PM CDT FRI JUL 17 2015
PESKY NARROW BAND OF CONVECTION FROM NORTHERN OZARKS TO S
SECTIONS OF STL METRO HAS BEEN FINALLY BEGUN TO WEAKEN OVER THE
PAST HOUR OR SO, WHILE CONVECTION OVER SOUTHERN IL HAS
INTENSIFIED JUST A BIT AS IT ENCOUNTERS A SLIGHTLY MORE FAVORABLE
ENVIRONMENT/SLIGHTLY COOLER MID LEVEL TEMPS. WILL MAINTAIN SOME
SLIGHT CHANCE POPS FOR VERY EARLY THIS EVENING FOR SOUTHEAST
SECTIONS OF THE CWA...DUE TO THE COMBINATION OF CURRENT ACTIVITY
AS WELL AS POTENTIAL FOR SOME OF THE WEAKENING UPSTREAM
CONVECTION OVER SW MO ADVECTING INTO THE AREA. OTHERWISE AND
ELSEWHERE...DRY WEATHER IS FORECAST WITH THE EMPHASIS REMAINING
ON THE WARM AND MUGGY JULY AIRMASS. HAVE GONE WITH LOWS IN THE
70S, BUT ITS CERTAINLY POSSIBLE THAT HEAT ISLAND OF STL METRO MAY
HAVE TROUBLE DIPPING BELOW 80.
TRUETT
.LONG TERM: (SATURDAY THROUGH NEXT FRIDAY)
ISSUED AT 239 PM CDT FRI JUL 17 2015
OPPRESSIVELY HOT AND HUMID CONDITIONS WILL LIKELY CONTINUE ACROSS
MOST OF THE AREA THROUGH SUNDAY EVENING UNTIL A COLD FRONT EDGES
INTO MO/IL ON SUNDAY NIGHT. NO CHANGES WERE MADE TO THE EXISTING
HEAT ADVISORY.
A WEAK VORT MAX ACCOMPANYING THE COLD FRONT SHOULD SUPPORT SCT
SH/TS AHEAD OF THE FRONT ON LATE SUNDAY AFTERNOON FOLLOWED BY
INCREASINGLY ELEVATED CONVECTION INVOF THE FRONT ON SUNDAY NIGHT
INTO MONDAY. MODELS SHOW THAT THE FRONT WILL BE MOVING INTO AN
ENVIRONMENT WITH AROUND 2000 J/KG OF CAPE AND 20-30 KTS OF 0-6 KM
SHEAR AS WELL AS 2" PWAT AND H7-H5 LAPSE RATES OF 6-6.5 DEG
C/KM...THEREFORE STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ON
SUNDAY AFTN/EVE.
ADDITIONAL VORT MAXES OR MCVS COULD SUPPORT ISO-SCT SH/TS EARLY
NEXT WEEK DURING A BRIEF PERIOD OF NW FLOW ALOFT UNTIL THE UPPER
RIDGE RE-ESTABLISHES ITSELF BY MID/LATE WEEK.
KANOFSKY
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1157 PM CDT FRI JUL 17 2015
VFR AND DRY THRU THE TAF PERIOD. HAVE ADDED LLWS FOR COU AND UIN
OVERNIGHT. OTHERWISE...WINDS WILL BE SLY AND BECOME SWLY SHORTLY
AFTER SUNRISE AS MIXING OCCURS. COU AND UIN MAY SEE GUSTS TO
AROUND 20 KTS DURING THE AFTERNOON.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR CRAWFORD
MO-IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR KNOX MO-LEWIS MO-
MARION MO-MONROE MO-PIKE MO-RALLS MO-SHELBY MO.
IL...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR BOND IL-
CLINTON IL-FAYETTE IL-MARION IL-MONTGOMERY IL-RANDOLPH IL-
WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR CALHOUN IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-ST. CLAIR IL.
HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR ADAMS IL-BROWN IL-PIKE
IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
420 AM EDT SAT JUL 18 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1241 AM EDT SATURDAY...THOUGH VIRGA OR VERY LIGHT SHOWERS
PREVAIL ACROSS MUCH OF VERMONT, STEADIER BAND OF RAIN HAS
DEVELOPED EXTENDING ALONG A MSS-SLK-GFL LINE AND WILL MOVE
EASTWARD INTO THE CHAMPLAIN VALLEY BEFORE MIDNIGHT, AND ACROSS THE
REST OF VERMONT AFTER MIDNIGHT. IN THE WAKE OF THIS WARM- FRONTAL
RAIN IS MORE SPOTTY, SCATTERED SHOWERS. UPSTREAM DETROIT RAOB
SHOWS SOME STEEPER MID- LEVEL LAPSE RATES IN A BROADLY CYCLONIC
WEST FLOW. THE LATEST RAP FORECAST PICKS UP ON THESE STEEPER LAPSE
RATES IN ITS DEPICTION OF WEAK NEGATIVE SHOWALTER INDICES
ADVECTING IN THROUGH THE OVERNIGHT. REGARDING POPS AND WEATHER,
I`VE ADDED IN SLIGHT CHANCE THUNDER TO THE GRIDS AFTER MIDNIGHT
ONCE THE MORE FOCUSED WARM FRONTAL RAIN LIFTS EAST.
CURRENT TEMPS GENERALLY IN THE MID 60S TO LOW 70S, WITH SOME
SLIGHT INCREASE IN DEWPOINTS SINCE EARLY EVENING - INTO THE UPPER
50S TO MID 60S. TEMPS WILL BE VERY SLOW TO FALL GIVEN SOUTH
WINDS, WARM ADVECTION REGIME AND OVERCAST SKIES. DEWPOINTS WILL
ALSO GRADUALLY BE ON THE CLIMB WITH MANY AREAS LIKELY TO BE IN THE
60S BY SUNRISE. SO ITS GOING TO BE AN INCREASINGLY MORE HUMID
NIGHT, WITH LOWS IN THE 60S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. CHANCE OF
SHOWERS INCREASES DURING TUESDAY AS SHORTWAVE TROUGH TROUGH AND
ASSOCIATED SURFACE COLD FRONT ADVANCE RAPIDLY EAST FROM THE GREAT
LAKES. SOME WEAK INSTABILITY INDICATED...SO HAVE INCLUDED SLIGHT
CHANCE THUNDER. CLOUDS WILL PREVENT TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. SHOWERS TAPER
OFF TUESDAY NIGHT WITH PASSAGE OF FRONT AND TROUGH. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW MORE AFTERNOON SHOWERS. SURFACE HIGH PRESSURE BUILDS IN
FOR LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...WIDESPREAD SHOWERS ACROSS THE REGION WILL
TAPER OFF FROM WEST TO EAST 08Z-12Z. VISIBILITIES LOWERING TO MVFR
AT TIMES IN PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS
LOWERING THROUGH THE NIGHT TO MVFR ALL SITES WITH IFR POSSIBLE
SLK/MPV AND POSSIBLY MSS. CEILINGS IMPROVE TO MVFR ALL SITES
12Z-16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN
VALLEY EAST. SOUTHERLY WINDS 5-10 KNOTS THRU 12Z AND UP TO 15-20
KNOTS IN CHAMPLAIN VALLEY AFT 12Z SAT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
12Z TUE - 00Z THU...MAINLY VFR. CHANCE AFTERNOON SHOWERS/THUNDERSTORMS
BOTH DAYS WITH BRIEF MVFR POSSIBLE..
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO
SHORT TERM...DEAL
LONG TERM...RJS
AVIATION...RJS
MARINE...MV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
159 AM EDT SAT JUL 18 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1241 AM EDT SATURDAY...THOUGH VIRGA OR VERY LIGHT SHOWERS
PREVAIL ACROSS MUCH OF VERMONT, STEADIER BAND OF RAIN HAS
DEVELOPED EXTENDING ALONG A MSS-SLK-GFL LINE AND WILL MOVE
EASTWARD INTO THE CHAMPLAIN VALLEY BEFORE MIDNIGHT, AND ACROSS THE
REST OF VERMONT AFTER MIDNIGHT. IN THE WAKE OF THIS WARM- FRONTAL
RAIN IS MORE SPOTTY, SCATTERED SHOWERS. UPSTREAM DETROIT RAOB
SHOWS SOME STEEPER MID- LEVEL LAPSE RATES IN A BROADLY CYCLONIC
WEST FLOW. THE LATEST RAP FORECAST PICKS UP ON THESE STEEPER LAPSE
RATES IN ITS DEPICTION OF WEAK NEGATIVE SHOWALTER INDICES
ADVECTING IN THROUGH THE OVERNIGHT. REGARDING POPS AND WEATHER,
I`VE ADDED IN SLIGHT CHANCE THUNDER TO THE GRIDS AFTER MIDNIGHT
ONCE THE MORE FOCUSED WARM FRONTAL RAIN LIFTS EAST.
CURRENT TEMPS GENERALLY IN THE MID 60S TO LOW 70S, WITH SOME
SLIGHT INCREASE IN DEWPOINTS SINCE EARLY EVENING - INTO THE UPPER
50S TO MID 60S. TEMPS WILL BE VERY SLOW TO FALL GIVEN SOUTH
WINDS, WARM ADVECTION REGIME AND OVERCAST SKIES. DEWPOINTS WILL
ALSO GRADUALLY BE ON THE CLIMB WITH MANY AREAS LIKELY TO BE IN THE
60S BY SUNRISE. SO ITS GOING TO BE AN INCREASINGLY MORE HUMID
NIGHT, WITH LOWS IN THE 60S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...WIDESPREAD SHOWERS ACROSS THE REGION WILL
TAPER OFF FROM WEST TO EAST 08Z-12Z. VISIBILITIES LOWERING TO MVFR
AT TIMES IN PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS
LOWERING THROUGH THE NIGHT TO MVFR ALL SITES WITH IFR POSSIBLE
SLK/MPV AND POSSIBLY MSS. CEILINGS IMPROVE TO MVFR ALL SITES
12Z-16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN
VALLEY EAST. SOUTHERLY WINDS 5-10 KNOTS THRU 12Z AND UP TO 15-20
KNOTS IN CHAMPLAIN VALLEY AFT 12Z SAT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
18Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL KMPV/KSLK.
12Z TUE - 00Z THU...MAINLY VFR. CHANCE AFTERNOON SHOWERS/THUNDERSTORMS
BOTH DAYS WITH BRIEF MVFR POSSIBLE..
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO
SHORT TERM...DEAL
LONG TERM...LAHIFF
AVIATION...RJS
MARINE...MV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1241 AM EDT SAT JUL 18 2015
.SYNOPSIS...
EXPECT AN ACTIVE WEEKEND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
WITH THE POTENTIAL FOR HEAVY RAINFALL. THE HEAVIEST RAIN WILL FALL
AHEAD OF A COLD FRONT THAT MOVES THROUGH THE AREA MONDAY. ANOTHER
FRONT WILL BRING A CHANCE OF SHOWERS AGAIN MID WEEK. AHEAD OF THE
COLD FRONT THIS WEEKEND HOT AND HUMID TEMPERATURES ARE EXPECTED
WITH TEMPERATURES APPROACHING 90 DEGREES IN THE VALLEYS.
TEMPERATURES BEHIND THE FRONT WILL TREND BACK TOWARDS MORE
SEASONABLE HIGHS NEAR 80 AND LOWS NEAR 60.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1241 AM EDT SATURDAY...THOUGH VIRGA OR VERY LIGHT SHOWERS
PREVAIL ACROSS MUCH OF VERMONT, STEADIER BAND OF RAIN HAS
DEVELOPED EXTENDING ALONG A MSS-SLK-GFL LINE AND WILL MOVE
EASTWARD INTO THE CHAMPLAIN VALLEY BEFORE MIDNIGHT, AND ACROSS THE
REST OF VERMONT AFTER MIDNIGHT. IN THE WAKE OF THIS WARM- FRONTAL
RAIN IS MORE SPOTTY, SCATTERED SHOWERS. UPSTREAM DETROIT RAOB
SHOWS SOME STEEPER MID- LEVEL LAPSE RATES IN A BROADLY CYCLONIC
WEST FLOW. THE LATEST RAP FORECAST PICKS UP ON THESE STEEPER LAPSE
RATES IN ITS DEPICTION OF WEAK NEGATIVE SHOWALTER INDICES
ADVECTING IN THROUGH THE OVERNIGHT. REGARDING POPS AND WEATHER,
I`VE ADDED IN SLIGHT CHANCE THUNDER TO THE GRIDS AFTER MIDNIGHT
ONCE THE MORE FOCUSED WARM FRONTAL RAIN LIFTS EAST.
CURRENT TEMPS GENERALLY IN THE MID 60S TO LOW 70S, WITH SOME
SLIGHT INCREASE IN DEWPOINTS SINCE EARLY EVENING - INTO THE UPPER
50S TO MID 60S. TEMPS WILL BE VERY SLOW TO FALL GIVEN SOUTH
WINDS, WARM ADVECTION REGIME AND OVERCAST SKIES. DEWPOINTS WILL
ALSO GRADUALLY BE ON THE CLIMB WITH MANY AREAS LIKELY TO BE IN THE
60S BY SUNRISE. SO ITS GOING TO BE AN INCREASINGLY MORE HUMID
NIGHT, WITH LOWS IN THE 60S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 343 PM EDT FRIDAY...TOMORROW IS STILL EXPECTED TO BE AN
ACTIVE DAY WITH SHOWERS AND THUNDERSTORMS STILL PROGRESSING ACROSS
THE REGION BEHIND THE WARM FRONT. THE WARM ADVECTION SHOWERS
SHOULD COME TO AN END SOME TIME IN THE MORNING WITH A CHANCE FOR
SOME LIGHT CLEARING. THE BEST CHANCE FOR CLEARING WILL BE ACROSS
NORTHERN NEW YORK AND NORTHERN VERMONT. AS THE SOUTHERLY WINDS
CONTINUE TO BRING IN MORE WARMER MOIST AIR EXPECT TOMORROW TO BE
QUITE MUGGY WITH SURFACE DEWPOINTS INCREASING TO THE UPPER 60S TO
NEAR 70 IN THE VALLEYS. THE HIGH DEW POINTS WILL COMBINE WITH
TEMPS AROUND 80 TO GENERATE 1500-2000 J/KG OF CAPE ALONG THE
INTERNATIONAL BORDER. WITH SURFACE CONVERGENCE INCREASING AS A
UPPER LEVEL SHORTWAVE VORT CROSSES THE NORTH COUNTRY EXPECT THERE
TO BE POTENTIAL FOR SOME STRONGER STORMS TO DEVELOP. I CONTINUED
THE MENTION OF HEAVY RAIN AND POTENTIAL FOR GUSTY WINDS IN THE
FORECAST BASED ON MODERATE 0-6KM SHEAR OF 30-40KTS AND THE
ENHANCED SURFACE AND ELEVATED INSTABILITY. EXPECT SCATTERED
SOUTHWESTWARD MOVING STORMS TO SLOWLY MOVE ACROSS THE AREA IN THE
AFTERNOON WITH RELATIVELY LIGHT CORFIDI VECTORS NORTHWEST AT 5-10KNOTS.
GIVEN THE LIGHT DIRECTIONAL WINDS AS THE PWATS INCREASE TO 2.0"
TOMORROW SOME OF THE STORMS COULD PRODUCE HEAVY RAINFALL AND
PRODUCE PONDING IN AREAS OF POOR DRAINAGE AND IN URBAN AREAS.
AS WE LOSE THE DIURNAL HEATING SATURDAY NIGHT EXPECT SHOWERS TO
DISSIPATE OVERNIGHT BEFORE FIRING AGAIN IN EARNEST BY MID MORNING
SUNDAY. SUNDAY WILL SEE CONTINUED HIGH DEWPOINTS WITH PLENTY OF
LOW LEVEL MOISTURE AND AS THE SHORTWAVE CLEARS THE REGION ON
SATURDAY EVENING EXPECT BETTER CLEARING ON SUNDAY MORNING. THE
RESULT OF THAT WILL BE AN EVEN BETTER CHANCE FOR SLOW MOVING
SHOWERS ON SUNDAY WITH DAYTIME TEMPERATURES IN THE UPPER 80S
APPROACHING NEAR 90 DEGREES IN THE SAINT LAWRENCE AND CHAMPLAIN
VALLEY. WITH WEAK SHEAR IN THE 0-6KM PROFILE I ANTICIPATE THE
THREAT FOR STRONG STORMS TO BE MINOR BUT WITH THE SURFACE
INSTABILITY STILL QUITE LARGE RANGING FROM 2000-3000 J/KG CAPE
OVER NORTHERN NEW YORK BY MID DAY ON SUNDAY STRONG TO SEVERE
STORMS CANT BE RULED OUT. DECENT LAPSE RATES IN THE 700-500MB
LAYER SHOW EVIDENCE OF A WELL DEVELOPED EML MOVING INTO THE AREA
SO THE THREAT OF HEAVY RAIN WILL CONTINUE SUNDAY AFTERNOON INTO
SUNDAY EVENING.
PWATS WILL BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL INTO SUNDAY
EVENING SO THE THREAT OF ISOLATE FLASH FLOODING IS POSSIBLE AND
THUS I WENT AHEAD AND UPDATED THE FORECAST TO SHOW THE ENHANCED
WORDING OF HEAVY RAINFALL FOR SUNDAY AFTERNOON AND SUNDAY EVENING
AHEAD OF THE COLD FRONT THAT PASSES THROUGH ON MONDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...SURFACE COLD FRONT SHIFTING THROUGH THE
FORECAST AREA MONDAY MORNING WITH PRECIPITATION EXITING FROM WEST
TO EAST THROUGH THE DAY. MAX TEMPS WILL BE TRICKY WITH UNCERTAINTY
IN THE EXACT FROPA TIMING, BUT GIVEN THE WARM OVERNIGHT TEMPERATURES
ANY CLEARING IN THE AFTERNOON SHOULD ALLOW TEMPS TO REBOUND INTO
THE LOWER 80S.
DRIER CONDITIONS RETURN FOR MONDAY NIGHT THROUGH TUESDAY NIGHT AS A
WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. A FEW WEAK
DISTURBANCES IN FLOW ALOFT COMBINED WITH SOME AFTERNOON INSTABILITY
MAY BE ENOUGH TO PRODUCE SOME SHOWERS OVER THE HIGHER TERRAIN
TUESDAY/WEDNESDAY, BUT OTHERWISE DRY WEATHER IS EXPECTED THROUGH THE
END OF THE WORK WEEK. TEMPS WILL RUN RIGHT AROUND NORMAL, MAYBE JUST
A FEW DEGREES ABOVE WITH HIGHS GENERALLY IN THE UPPER 70S TO MID 80S
AND LOWS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS WITH MID-HIGH CEILINGS WILL
QUICKLY LOWER WITH ASSOCIATED PRECIP/SHOWERS DEVELOP BETWEEN 00Z
AND 03Z SATURDAY. CIGS LOWERING TO MVFR AREA-WIDE AND LOCALLY IFR
FOR A BRIEF PERIOD AT KSLK/KMPV. PRECIP SHIFTS OUT OF THE REGION
AFTER 09-12Z WITH MVFR CIGS TRENDING TO VFR BY 18Z. HOWEVER...SOME
-SHRA/-TSRA MAY DEVELOP AFT 18Z BUT ARE NOT CURRENTLY IN TAFS DUE
TO UNCERTAINTY IN COVERAGE/TIME. SOUTHERLY WINDS 5-10KTS THRU 12Z
AND UP TO 15-20 KTS IN CHAMPLAON VALLEY AFT 12Z SAT.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SAT - 06Z SUN...VFR/MVFR. SCATTERED SHOWERS AND
THUNDERSTORMS, MAINLY ACROSS VT ENDING.
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG POSSIBLE AT
KMPV/KSLK.
18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS.
18Z MON - 12Z WED...MAINLY VFR. EARLY MORNING IFR
FOG POSSIBLE AT KMPV/KSLK.
12Z WED - 00Z THU...MAINLY VFR. CHANCE
AFTERNOON -SHRA.
&&
.MARINE...
AS OF 252 PM EDT FRIDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN AFTER 8PM LASTING THROUGH THE OVERNIGHT HOURS. WIND
WAVES ARE EXPECTED TO REACH 2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO
SHORT TERM...DEAL
LONG TERM...LAHIFF
AVIATION...LAHIFF/SLW
MARINE...MV
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 AM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 305 AM SATURDAY...
TODAY: COMPLEX OF SHOWERS AND STORMS IS STILL GOING THIS MORNING
OVER PORTIONS OF EASTERN KY. HOWEVER... THE COMPLEX OF SHOWERS AND
STORMS IS SHOWING A DOWNWARD TREND IN INTENSITY AS IT SHIFTS EAST
AND SOUTHWARD. THE LATEST HRRR SHOWS THIS DISTURBANCE CONTINUING TO
WEAKEN THIS MORNING AS IT APPROACHES THE AREA. HOWEVER... AS THE
REMNANTS OF THE MCS MOVE ACROSS THE AREA LATE THIS MORNING AND INTO
THE AFTERNOON EXPECT WE SHOULD SEE REDEVELOPMENT ALONG AND AHEAD OF
THIS FEATURE... AND ALONG THE DEVELOPING LEE SIDE SURFACE TROUGH
ACROSS THE AREA FROM SW TO NE. WHILE THE LATEST HRRR SHOWS POSSIBLY
SOME ISOLATED CONVECTION DEVELOPING BY AS EARLY AS 12Z ACROSS THE
PIEDMONT... THINK THE BULK OF THE CONVECTION SHOULD OCCUR FROM THE
AFTERNOON INTO THE EVENING... DEVELOPING FIRST ACROSS THE PIEDMONT
(PROBABLY WESTERN PIEDMONT) THEN EXPANDING EAST AND SOUTHWARD.
THUS... WILL GO WITH SOLID CHANCE POPS FOR TODAY... EXPECTING
SCATTERED SHOWERS AND STORMS. WITH REGARD TO THE POTENTIAL FOR SVR
STORMS. MLCAPE VALUES ARE EXPECTED TO RANGE FROM GENERALLY 1000-2000
J/KG ACROSS THE AREA BY AFTERNOON AS THE AIRMASS CONTINUES TO
MOISTEN AND WARM IN THE WAKE OF THE DEPARTING SURFACE HIGH.
HOWEVER... DEEP LAYER SHEAR VALUES SHOULD GENERALLY BE LESS THAN 20-
25 KTS. THUS... WHILE WE COULD SEE SOME MULTICELLULAR ACTIVITY...
DONT EXPECT A LARGE LINE OF STORMS TO CROSS THE AREA. THE LATEST SPC
DAY 1 CONVECTIVE OUTLOOK HAS CENTRAL NC IN THE MARGINAL CATEGORY (A
FEW STRONG TO SEVERE STORMS POSSIBLE)... WHICH SEEMS REASONABLE
GIVEN THE ABOVE MENTIONED SETUP... WITH THE MAIN THREAT FROM
DAMAGING WIND GUSTS.
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 125 AM SATURDAY...
24-HR TAF PERIOD: VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL
THIS MORNING AND INTO EARLY THIS AFTERNOON AT MOST LOCATIONS.
HOWEVER... WE COULD SEE SOME PATCHY FOG DEVELOP THIS MORNING DURING
THE PRE-DAWN HOURS ACROSS THE COASTAL PLAIN AND SANDHILLS. FOG PRONE
KRWI APPEARS TO STAND THE BEST CHANCE OF SEEING SOME TEMPORARY SUB-
VFR VISBYS... THUS HAVE INTRODUCED A TEMPO GROUP BETWEEN 08-11Z THIS
MORNING FOR SUB-VFR VISBYS AT KRWI. ISOLATED TO SCATTERED SHOWERS
AND STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING WITH
THE APPROACH OF A MID LEVEL DISTURBANCE FROM THE NORTHWEST. GIVEN
CONFIDENCE IS NOT HIGH IN NARROWING DOWN AN EXACT TIME AND COVERAGE
YET... HAVE ELECTED TO INCLUDE A PROB30 GROUP FOR THIS AFTERNOON
INTO THE EVENING FOR ALL SITES... WITH GUSTY WINDS AND SUB-VFR
CONDITIONS POSSIBLE WITH ANY STORMS.
LOOKING AHEAD: WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH
EARLY/MID NEXT WEEK...A RELATIVELY ENERGETIC SUMMER-TIME PATTERN IN
WHICH DIURNAL CONVECTION WILL POSE THE GREATEST CONCERN TO AVIATION.
NON-DIURNAL (I.E. OVERNIGHT) CONVECTION CANNOT BE RULED OUT IN THE
PRESENCE OF NW FLOW ALOFT...I.E. IF UPSTREAM MESOSCALE CONVECTIVE
SYSTEMS (MCS`S) PROPAGATE INTO THE REGION. MORNING STRATUS AND/OR
FOG WILL ALSO BE POSSIBLE EACH DAY GIVEN SEASONABLE MOISTURE...
PERIODS OF WEAK WARM ADVECTION... AND THE PRESENCE OF CONVECTION
DURING THE LATE EVENING HOURS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
249 AM EDT SAT JUL 18 2015
.SYNOPSIS...
HOT AND HUMID FOR THE WEEKEND. SOME AFTERNOON THUNDERSTORMS
POSSIBLE. COLD FRONT IN VICINITY EARLY IN WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
NAM DOES NOT HAVE THE COMPLEX MOVING THROUGH EARLY THIS MORNING...SO
NOT SURE THAT THE MOISTURE FIELDS ARE REPRESENTATIVE AT LATER TIMES.
THEREFORE WILL RELY MORE ON THE HRRR AND THE GFS WHICH HANDLE THE
COMPLEX A BIT BETTER...THOUGH NOT PERFECTLY. THIS WILL ALLOW FOR
SOME THUNDERSTORMS TODAY...BUT DRY AIR PUNCHING IN FROM THE WEST
WILL LIMIT ACTIVITY TO THE MOUNTAINS BY LATER THIS AFTERNOON. THIS
DRY AIR WILL ALSO CAP THE AREA DURING THE EVENING AND OVERNIGHT
HOURS. WITH THE MOIST GROUND...MET MOS LOOKS WAY TO HIGH FOR TODAYS
HIGHS. WILL STAY CLOSER TO THE GFS MOS.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/... A VERY SIMILAR DAY AS TODAY
IS EXPECTED ON SUNDAY WITH JUST AN ISOLATED SHOT A SHOWER OR STORM
AND MAINLY OVER THE HIGH TERRAIN. BY SUNDAY EVENING...A S/W TROF AND
ASSOCIATED COLD FRONT WILL MAKE A RUN INTO THE AREA WITH A LINE OF
SHOWERS AND STORMS...SOME OF WHICH MAY BE ON THE STRONG SIDE OVER SE
OH. HAVE SOME LIKELY POPS OVER MUCH OF THE AREA SUNDAY NIGHT UNTIL
THE TROF CAN PASS AND THE FRONT SLIP S. WHILE THE UPPER LEVEL
DISTURBANCE PASSES SAFELY THRU...THE SAME CANNOT BE SAID FOR THE
SURFACE BOUNDARY WHICH WILL RETURN N INTO THE AREA LATE MONDAY AND
BECOME NEARLY QUASI STATIONARY. THIS COMBINED WITH GOOD INSTABILITY
AND SOME PERTURBATIONS IN THE UPPER LEVEL FLOW...MEANS A RENEWED
FLASH FLOOD THREAT MONDAY NIGHT AND TUESDAY.
THINK BEST SHOT OF REACHING HEAT ADV CRITERIA ON SUNDAY WOULD
GENERALLY BE ALONG AND S OF I64. OTHERWISE...UPPER 80S TO LOW 90S
COMBINED WITH DEWPOINTS IN THE LOW 70S MEANS HEAT INDICES IN THE MID
TO UPPER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
COLD FRONT WILL MOVE INTO THE AREA ON MONDAY. THERE IS THE
POTENTIAL FOR A FEW STRONG TO SEVERE STORMS ON MONDAY...BUT THIS
IS STILL UP IN THE AIR A BIT...AND WILL RELY SOMEWHAT ON TIMING OF
FRONT. FRONTAL BOUNDARY WILL EVENTUALLY STALL OUT ACROSS THE
SOUTHERN HALF OF THE AREA BRIEFLY...BEFORE SAGGING SOUTH LATER IN
THE DAY ON TUESDAY. HOWEVER...ANOTHER SYSTEM WILL AFFECT THE AREA
MID TO LATE WEEK. THUS...HEADING INTO YET ANOTHER WET
PERIOD...WITH THE POTENTIAL FOR CONTINUED WATER PROBLEMS.
HIGHLIGHTED IN THE HWO.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
THE REMAINS OF A COMPLEX WILL MOVE THROUGH EASTERN KY...SOUTHERN
WV...AND SOUTHWESTERN VA EARLY THIS MORNING. SOME HEAVIER
THUNDERSTORMS COULD BRIEFLY CAUSE SOME IFR OR MVFR CONDITIONS...BUT
VFR CONDITIONS WILL PREVAIL FOR THE MAJORITY OF THE TIME.
A CUMULUS DECK WILL THEN FORM ON SATURDAY...STARTING A BIT LOWER
THAN NORMAL DUE TO THE HIGH HUMIDITY. SOME SCATTERED AFTERNOON
THUNDERSTORMS CAN BE EXPECTED IN THE MOUNTAINS. THESE ARE NOT
EXPECTED TO LINGER INTO THE EVENING HOURS AS DRY AIR WILL PUSH IN
FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS...DUE TO THE SCATTERED AND LIMITED NATURE OF ANY
IFR/MVFR CONDITIONS IN HEAVY RAIN THIS MORNING...THESE CONDITIONS
ARE NOT INCLUDED IN THE BKW TAF...JUST LIGHTER PRECIPITATION.
AFTER 06Z SUNDAY...
IFR IN MORE WIDESPREAD SHOWERS/STORMS SUNDAY NIGHT OR MONDAY NEAR
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...SL
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
308 AM EDT SAT JUL 18 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE NORTHEAST CONUS THIS
WEEKEND. A SHORT WAVE PASSING TO THE NORTH WILL PUSH A COLD FRONT
THROUGH PENNSYLVANIA ON MONDAY. HIGH PRESSURE IS LIKELY TO BUILD
SOUTHEAST INTO PENNSYLVANIA WEDNESDAY OR THURSDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
HEAVY SHRA/TSRA FIRING OVR THE CENTRAL MTNS AT NOSE OF LL JET AS
OF 06Z. HIGH PWATS AND TRAINING CELLS POSE AT THREAT OF LOCALIZED
FLOODING ALONG THE I-80 CORRIDOR BTWN 06Z-09Z. HOWEVER...NEAR TERM
MDL DATA SUGGESTS LL JET AND ASSOC CONVECTION WILL WEAKEN AND PUSH
EAST OF THE CWA BY ARND DAWN. RADAR TRENDS AND LATEST HRRR SUPPORT
CAT TO LIKELY POPS ALONG THE I-80 CORRIDOR DURING THE PRE-DAWN
HOURS AND MUCH LOWER POPS OVER SOUTHERN PA AND THE N TIER.
TEMPS WON/T FALL MUCH FROM 06Z READINGS DUE TO HIGH HUMIDITY NOW
COVERING THE AREA. EXPECT MIN TEMPS ARND 70F ACROSS ALL OF CENTRAL
PA.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM SUNDAY/...
SHORTWAVE SHOULD HAVE PASSED EAST OF THE REGION BY DAWN...LEAVING
CENTRAL PA IN A REGION OF WEAK LG SCALE FORCING. EXPECT A DRY
MORNING OVR NEARLY THE ENTIRE AREA. HOWEVER...HEATING OF
MOIST/UNSTABLE AIR MASS SHOULD SPAWN SCT PM CONVECTION...WITH
GREATEST COVERAGE LIKELY ALONG AXIS OF HIGHEST PWATS OVER EASTERN
PA. ARRIVAL OF UPPER RIDGE AXIS AND ASSOC WARM TEMPS ALOFT SHOULD
LIMIT COVERAGE OF ANY STORMS ACROSS THE NW COUNTIES.
MODEL CAPES ABOUT AS HIGH AS WE SEE IN PA...BTWN 3000-5000 J/KG
SAT AFTN. HIGH CAPE AND WEAK SHEAR IMPLIES A LOW END THREAT OF
ISOLD PULSE TYPE SVR STORMS. SPC HAS ENTIRE AREA IN MGRL RISK.
BOUNDARY LAYER WARMING SUPPORTS WIDESPREAD HIGHS OF 85 TO 90. THIS
COMBINED WITH SFC DEWPOINTS IN THE LOWER 70S SHOULD CREATE HEAT
INDICES AS HIGH AS THE MID 90S IN THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE RETURN TO MORE SUMMERLIKE WEATHER WILL CONTINUE ON
SUNDAY...AS 850HPA TEMPS RISE TO +2SD BY SUNDAY AFTN. AS TEMPS
CONTINUE TO WARM AND HUMIDITY CONTINUES TO CLIMB...HEAT INDICES
WILL APPROACH 100F /BORDERLINE HEAT ADVISORY CRITERIA/ IN THE
LOWER SUSQUEHANNA VALLEY SUNDAY AFTN.
A COLD FRONT WILL CROSS CENTRAL PA SUN NIGHT/EARLY
MONDAY...ACCOMPANIED BY A CHC FOR SHRA/TSRA. THE TIMING OF THE
FRONT EARLY IN THE DAY MAY BE A LIMITING FACTOR FOR SEVERE WX.
BEHIND THE FRONT...TEMPS WILL BE /SLIGHTLY/ COOLER AND THERE WILL
BE A RESPITE FROM THE MUGGINESS.
HIGH PRESSURE WILL ATTEMPT TO BUILD OVERHEAD LATE NEXT
WEEK...BEHIND ANOTHER WEAK COLD FRONT THAT IS FORECAST TO SETTLE
ACROSS CENTRAL PA NEXT WEDNESDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
ACTIVE CLUSTER OF THUNDERSTORMS ACROSS CENTRAL AREAS OF THE REGION
TONIGHT. EARLIER...STORMS MOVED THROUGH KBFD AND KUNV. THE NEWLY
DEVELOPING STORMS WILL MAINLY BE SOUTH OF KBFD AND NORTH OF KAOO.
KUNV AND EVENTUALLY KIPT WILL AGAIN BE AFFECTED BY A ROUND OF
SHRA/TSRA.
INCREASED LOW LEVEL MOISTURE FROM THE CONVECTION...COUPLED WITH
LIGHT WINDS WILL LEAD TO OVERALL DEVELOPMENT OF LOWER CIGS ACROSS
MUCH OF THE REGION. EVEN THE LOWER SUSQUEHANNA VALLEY WITH AN
INFLUX OF LOW LEVEL MOISTURE HAS SEEN CIGS DROP INTO MVFR RANGE.
THIS WILL BE THE TREND OVERNIGHT...WITH WIDESPREAD MVFR TO IFR
CONDITIONS IN LOWER CLOUDS AND FOG. THERE MAY BE SOME LOCALLY
LOWER CONDITIONS IN ANY THUNDERSTORM ACTIVITY.
MOST IMPACTED HAS
BEEN KUNV...BUT BEFORE THE NIGHT IS OVER...KAOO AND KJST COULD
ALSO GET INTO THE SHRA/TSRA ACTION.
CONDITIONS DRY OUT FOR THE DAYTIME HOURS ON SATURDAY WITH VFR
CEILINGS AND VISIBILITIES RETURNING BY 13Z-15Z. AN ISOLATED
SHOWER OR THUNDERSTORM IS POSSIBLE AS DEWPOINTS REMAIN NEAR
70...HOWEVER NOT ENOUGH COVERAGE TO PLACE IN THE EXTENDED PORTION
OF THE FORECAST.
OUTLOOK...
SUN...SCT...MAINLY PM TSRA IMPACTS POSSIBLE.
MON...MORE NUMEROUS SHOWERS/TSRA LIKELY AS A COLD FRONT PUSHES
EAST ACROSS THE REGION.
TUE-WED...IMPROVING CONDS AS HIGH PRESSURE DOMINATING.
&&
.EQUIPMENT...
THE KBFD OBSERVATIONS ARE NOT AVAILABLE LONG-LINE DUE TO AN FAA COMMS
PROBLEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...EVANEGO
AVIATION...JUNG/TYBURSKI
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
303 AM CDT SAT JUL 18 2015
.DISCUSSION...
LINGERING MOISTURE LEVELS AND A SLIGHT WEAKNESS ALOFT MIGHT BE ENOUGH
TO GENERATE SOME SHOWERS AND POSSIBLE THUNDERSTORMS AGAIN TODAY...BUT
DO THINK COVERAGE WILL BE LESS THAN WHAT PARTS OF THE AREA SAW ON FRIDAY.
SPC`S LATEST DAY 1 CONVECTIVE OUTLOOK HAS PARTS OF OUR AREA IN GENERAL
THUNDER ONCE AGAIN...AND THE HRRR RUNS COMING IN SO FAR EARLY THIS MORNING
DO SHOW SOME ACTIVITY DEVELOPING DURING THE DAY. SO WILL CARRY 20% POPS
FOR THE COUNTIES GENERALLY ALONG AND SOUTH OF THE HIGHWAY 59 CORRIDOR.
WILL GO BACK TO A DRY FORECAST BEGINNING THIS EVENING AND CONTINUING
ON FOR THE REST OF THE WEEKEND AND THROUGHOUT THE UPCOMING WEEK AS
IT LOOKS LIKE MID/UPPER LEVEL RIDGING WILL BE STRONG ENOUGH TO KEEP
THE MAJORITY OF OUR AREA VERY WARM AND DRY. EVEN THOUGH WE WILL CONTINUE
TO SEE HEAT INDEX VALUES ACROSS A MAJORITY OF OUR AREA UNDER HEAT ADVISORY
LEVELS...US AND OUR PARTNERS WILL NEED TO CONTINUE TO GET THE WORD OUT
ON HEAT SAFETY.
FOR JULY 1-17...GALVESTON`S AVERAGE TEMPERATURE HAS BEEN 85.7 DEGREES.
IF THIS VALUE HOLDS FOR THE REST OF THE MONTH...JULY 2015 WOULD GO
DOWN AS THE 8TH WARMEST JULY ON RECORD. IN ADDITION...THEIR RAINFALL
TOTAL FOR THE MONTH OF 0.23 INCHES WOULD GO DOWN AS THE 7TH DRIEST
JULY ON RECORD. 42
&&
.MARINE...
HIGH PRESSURE CONTINUES TO RESIDE OVER THE GULF THE NEXT SEVERAL
DAYS AFFORDING A LIGHT SOUTHWEST TO SOUTHEAST WIND...PERIODS OF
WEEKEND SCATTERED SHOWERS. A SLIGHTLY TIGHTER LAND AND SEA THERMAL
GRADIENT WILL STRENGTHEN WINDS A BIT DURING THE OVERNIGHT HOURS.
SEAS WILL GENERALLY REMAIN AT OR UNDER THREE FEET...WITH AVERAGE
FOUR HEIGHTS WHERE THIS MORE MODERATE LATE EVENING INTO EARLY
MORNING ONSHORE FETCH EXISTS. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 76 97 76 98 / 10 0 0 0 10
HOUSTON (IAH) 96 77 97 76 97 / 20 0 10 0 10
GALVESTON (GLS) 91 82 91 81 92 / 20 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
320 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 101 AM EDT SATURDAY...
VFR ACROSS THE REGION WILL GRADUALLY GIVE WAY TO LOWERING CIGS
OVER THE WESTERN MOUNTAINS OVERNIGHT AND ALONG THE BLUE RIDGE
PRIOR TO DAYBREAK. LEADING OUTFLOW DRIVEN SHRA/TSRA MAY PUSH INTO
THE KBLF/KLWB CORRIDOR PRIOR TO DAWN WITH MVFR CIGS AND POSSIBLY A
PERIOD OF MVFR/IFR VSBYS PENDING HOW FAR EAST ANY OF THE RESIDUAL
CONVECTION MAKES IT. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO
KBCB AND KROA. THUS INCLUDED A TEMPO GROUP AT KBLF/KLWB FOR LOWER
VSBYS/CIGS WITHIN SHRA/TSRA...AND ADDED A VCSH FARTHER EAST TO
THE BLUE RIDGE IN LINE WITH THE LATEST HRRR OUTPUT.
SOME OF THESE WEAKENING SHOWERS MAY PUSH INTO EASTERN SECTIONS
SATURDAY MORNING WITH PLENTY OF DEBRIS CLOUDS MAKING FOR LINGERING
LOW END VFR TO MVFR CIGS OVER THE WEST THROUGH MIDDAY SATURDAY.
SHOULD FINALLY SEE A RETURN TO VFR FOR A WHILE SATURDAY AFTERNOON
AS HEATING WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN
THE LEE OF THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES
WITH AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE
MID DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON
AROUND 4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST
AND ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR
HEATING TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
112 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER SATURDAY
AFTERNOON. ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE
NORTHWEST BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW
PRESSURE RIDE ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT
WEEK. THIS WILL CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS
THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 920 PM EDT FRIDAY...
00Z RNK SOUNDING SHOWING AMPLE SBCAPE OF 3200 J/KG...BUT LACKING
MOISTURE AND TRIGGERING MECHANISM. ATTM...RADAR IS CLEAR EXCEPT
FOR A LEADING EDGE OF SHOWERS/STORMS FROM UPSTREAM CONVECTION
MOVING TOWARD HTS WV. A THETA-E RIDGE PROTRUDES TOWARD THE
GREENBRIER VALLEY THIS EVENING SOME MOISTURE CONVERGENCE...SO KEPT
SLIGHT CHANCE IN THIS AREA TIL MIDNIGHT THEN SHOULD GRADUALLY SEE
THE UPSTREAM SHOWERS AND STORMS MOVE INTO THE MTNS AFTER
MIDNIGHT...BUT IN A WEAKENED STATE.
THE TEMPS AND DEWPOINTS REMAIN ELEVATED...AND LOWS TONIGHT ON
TRACK FOR MID 60S MTNS TO LOWER 70S PIEDMONT...AS CLOUDS INCREASE
OVERNIGHT.
PREVIOUS DISCUSSION ISSUED EARLIER THIS AFTERNOON...
MAIN FOCUS THROUGH THIS PERIOD WILL BE ON A SHORT WAVE...CURRENTLY
MOVING THROUGH THE GREAT LAKES. THE MAIN DYNAMICS FROM THIS SYSTEM
WILL TRACK TO OUR NORTHEAST AS A BROAD UPPER RIDGE REMAINS ACROSS
THE ENTIRE SOUTHERN U.S. HOWEVER...THUNDERSTORMS DEVELOPING ACROSS
IN/OH THIS AFTERNOON HAVE THE POTENTIAL TO DRIFT SOUTHEAST
OVERNIGHT...AS INDICATED BY SEVERAL OF THE SYNOPTIC-SCALE MODELS.
THE MESO-SCALE MODELS ARE IN LESS AGREEMENT ABOUT THIS...HINGING
MORE ON DIURNAL DEVELOPMENT ACROSS THE MOUNTAINS...WHICH AS OF
THIS WRITING HAS FAILED TO MATERIALIZE. THE SOLUTION PRESENTED BY
THE GFS...AND SEVERAL OF THE SYNOPTIC MODELS...SEEMS PLAUSIBLE
GIVEN THE PATTERN AND RECENT TREND OF THIS IN RECENT WEEKS.
THEREFORE...CURRENT THINKING IS THAT A REMNANT MCS/CONVECTIVE
COMPLEX WILL DRIFT INTO THE WV MOUNTAINS AFTER MIDNIGHT...THEN
DIMINISH AS IT ATTEMPTS TO CROSS THE MOUNTAINS. NOT REALLY
EXPECTING MUCH MORE THAN A FEW LIGHT SHOWERS TO MAKE IT EAST OF
THE MOUNTAINS AND MOST LIGHTNING/THUNDER SHOULD BE GONE BY THE
11Z-12Z TIME FRAME.
SATURDAYS FORECAST DEPENDS LARGELY ON THE ABOVE SCENARIO UNFOLDING
AS EXPECTED. CONSIDERABLE CONVECTIVE CLOUD DEBRIS AND EVEN LIGHT
SHOWERS SHOULD BE LINGERING AT DAYBREAK AND SHORTLY THEREAFTER
ACROSS THE WESTERN PART OF THE CWA...WEST OF THE BLUE RIDGE. THIS
CLOUD COVER...COMBINED WITH THE BETTER UPPER-LEVEL DYNAMICS
SHIFTING INTO THE PIEDMONT/NC AREA BY AFTERNOON...SHOULD LEAVE THE
NORTHWEST HALF OF THE CWA CLOUDY AND MAINLY CONVECTIVE FREE
THROUGH MUCH OF THE DAY UNTIL PERHAPS ISOLATED DIURNAL ACTIVITY
DEVELOPS ACROSS THE MOUNTAINS LATER IN THE DAY. HOWEVER...EAST AND
SOUTH OF THE BLUE RIDGE...WOULD EXPECT MORE WIDESPREAD CONVECTION
TO DEVELOP FROM DIFFERENTIAL HEATING ON THE EDGE OF MORNING CLOUD
DEBRIS...AND IN AN AREA OF BETTER HEATING AND INSTABILITY. THERE
COULD POSSIBLE EVEN BE A FEW STRONG TO SEVERE THUNDERSTORMS IN
THIS AREA DURING THE AFTERNOON...BUT CONFIDENCE IS LOW IN THIS AND
SPC DOES NOT CURRENTLY HAVE ANY AREA HIGHLIGHTED FOR SUCH. ONLY
SLIGHTLY BETTER THAN A PULSE-TYPE THUNDERSTORM ENVIRONMENT. ANY
CONVECTION WILL DRIFT SOUTH OF THE CWA SHORTLY AFTER SUNSET.
TEMPERATURES WILL BE MOSTLY ABOVE NORMAL THROUGH THE PERIOD.
CONSIDERABLE CLOUD COVER TONIGHT WILL LIMIT COOLING WEST AND
LIKELY RADIATIONAL FOG AS WELL. WESTERN AREAS MAY REMAIN A TAD
COOLER SATURDAY THAN TODAY BECAUSE OF CLOUD COVER...BUT LATE
AFTERNOON BREAKS COULD ALLOW TEMPERATURES TO RECOVER FAIRLY
QUICKLY. 850MB TEMPS HOVER NEAR +20C...OF SLIGHTLY HIGHER
PIEDMONT...SO THERE IS LITTLE COOLING TO BE HAD OTHER THAN CLOUDS
AND PRECIPITATION.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 300 PM EDT FRIDAY...
SUBTROPICAL RIDGING OVER THE WESTERN GULF COAST REGION WILL BUILD
EAST THROUGH THE PERIOD...WHILE SOUTHWESTERLY WINDFLOW IN THE LOW
LEVELS WILL CONTINUE TO DRAW WARM HUMID AIR UP THE APPALACHIAN
CHAIN. AS SUCH...WE CAN EXPECT TEMPERATURES FOR SUNDAY AND MONDAY TO
BE SOME OF THE WARMEST OUR AREA HAS EXPERIENCED THIS SUMMER AS
AFTERNOON HIGHS RANGE FROM THE MID/UPPER 80S ACROSS THE MOUNTAINS...
TO THE LOW/MID 90S ACROSS THE PIEDMONT...PERHAPS A FEW UPPER 90S
ACROSS THE SOUTHSIDE. THESE TEMPERATURES WILL PUSH HEAT INDICES INTO
THE 100F TO 105F RANGE BOTH DAY EAST OF A DANVILLE TO LYNCHBURG
LINE...AND WE MAY BE ISSUING OUR FIRST HEAT ADVISORIES OF THE
YEAR. OVERNIGHTS WILL BE ON THE WARM AND MUGGY SIDE...WITH LOWS
RANGING FROM THE MID 60S TO THE LOW 70S AREAWIDE.
NOT MUCH SUPPORT FOR MORE THAN SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY FOR SUNDAY...MAINLY ACROSS THE MOUNTAINS DURING THE
AFTERNOON AND EARLY EVENING...BUT PERHAPS WITH A FEW STORMS DRIFTING
ACROSS THE PIEDMONT BEFORE SUNSET. INSTABILITY WILL REMAIN
MARGINAL...WITH CAPES RISING TO AROUND ~1500 J/KG...WHICH WILL
SUPPORT A FEW STRONG STORMS.
EXPECT MORE WIDESPREAD CONVECTION ON MONDAY HOWEVER DUE TO STRONGER
SURFACE CONVERGENCE AS A COLD FRONT SINKS SOUTH TOWARD OUR AREA.
UPPER LEVEL WINDS REMAIN WEAK...BUT WITH DEEPER MOISTURE POOLING
ACROSS OUR AREA AHEAD OF THE FRONT PUSHING PRECIPITABLE WATER VALUES
TO THE 1.5 TO 1.8 INCH RANGE FOR OUR AREA...LOOKING AT BETTER
CHANCES FOR PRECIPITATION LOADING TO ENHANCE THUNDERSTORMS
DOWNDRAFTS. COMBINE THAT WITH CAPES EXCEEDING 2000 J/KG...AND ITS
LOOKING LIKE A DECENT CHANCE FOR SOME STORMS TO BECOME SEVERE. THE
COLD FRONT WILL CONTINUE TO SINK SOUTH INTO THE EVENING...EVENTUALLY
SETTLING SOMEWHERE OVER OR AROUND OUR AREA BY DAWN TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 101 AM EDT SATURDAY...
VFR ACROSS THE REGION WILL GRADUALLY GIVE WAY TO LOWERING CIGS
OVER THE WESTERN MOUNTAINS OVERNIGHT AND ALONG THE BLUE RIDGE
PRIOR TO DAYBREAK. LEADING OUTFLOW DRIVEN SHRA/TSRA MAY PUSH INTO
THE KBLF/KLWB CORRIDOR PRIOR TO DAWN WITH MVFR CIGS AND POSSIBLY A
PERIOD OF MVFR/IFR VSBYS PENDING HOW FAR EAST ANY OF THE RESIDUAL
CONVECTION MAKES IT. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO
KBCB AND KROA. THUS INCLUDED A TEMPO GROUP AT KBLF/KLWB FOR LOWER
VSBYS/CIGS WITHIN SHRA/TSRA...AND ADDED A VCSH FARTHER EAST TO
THE BLUE RIDGE IN LINE WITH THE LATEST HRRR OUTPUT.
SOME OF THESE WEAKENING SHOWERS MAY PUSH INTO EASTERN SECTIONS
SATURDAY MORNING WITH PLENTY OF DEBRIS CLOUDS MAKING FOR LINGERING
LOW END VFR TO MVFR CIGS OVER THE WEST THROUGH MIDDAY SATURDAY.
SHOULD FINALLY SEE A RETURN TO VFR FOR A WHILE SATURDAY AFTERNOON
AS HEATING WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN
THE LEE OF THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES
WITH AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE
MID DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON
AROUND 4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST
AND ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR
HEATING TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...RAB/WP
SHORT TERM...NF
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
624 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN
PLAINS...ESPECIALLY IN THE NORTH PART OF THE FORECAST AREA.
EXPECT AN INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH
THIS UPPER FEATURE. THERE WILL ALSO BE SOME CONVERGENCE INTO THE
LEE-SIDE TROUGH IN THE FORECAST AREA. THE HRRR AND ARW DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTH PART OF THE FORECAST AREA
DURING THE MID TO LATE AFTERNOON WITH A SOUTHEASTWARD MOVEMENT.
THE HIGH-RESOLUTION MODELS HAD CONSIDERABLE COVERAGE IN THE NORTH
SECTION BUT LESS COVERAGE IN THE REST OF THE AREA DURING THE
AFTERNOON INTO THE EVENING. BASED ON THE INITIAL DRYNESS AND
LINGERING UPPER RIDGING THUNDERSTORM COVERAGE MAY REMAIN LIMITED.
WE FORECASTED THE HIGHER CHANCE IN THE NORTH PART BASED ON THE
HIGH-RESOLUTION MODELS AND MORE PRONOUNCED INFLUENCE OF THE MID-
LEVEL SHORTWAVE TROUGH. THE NAM INDICATED SURFACE-BASED LI/S -6 TO
-7 TODAY. THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE
SOUNDING INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF
THE THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE
BASED ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH OR FRONT MAY ALSO
STALL NEAR THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN
SUPPORTS ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS.
THE GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8
DEGREES ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT IMPROVING TO VFR BY 15Z. WINDS WILL BE
LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A WEAK
SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO
WILL LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
613 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A SURFACE PRESSURE TROUGH WILL BE IN THE FORECAST AREA THROUGH
SUNDAY. ALOFT...HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE
SOUTHERN PLAINS. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES
WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MID-LEVEL SHORTWAVE TROUGH SHOWN BY THE WATER VAPOR IMAGERY
OVER THE OHIO VALLEY EARLY THIS MORNING SHOULD HELP WEAKEN THE
RIDGING EXTENDING INTO THE FORECAST AREA FROM THE SOUTHERN
PLAINS...ESPECIALLY IN THE NORTH PART OF THE FORECAST AREA.
EXPECT AN INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH
THIS UPPER FEATURE. THERE WILL ALSO BE SOME CONVERGENCE INTO THE
LEE-SIDE TROUGH IN THE FORECAST AREA. THE HRRR AND ARW DISPLAYED
THUNDERSTORMS MOVING INTO THE NORTH PART OF THE FORECAST AREA
DURING THE MID TO LATE AFTERNOON WITH A SOUTHEASTWARD MOVEMENT.
THE HIGH-RESOLUTION MODELS HAD CONSIDERABLE COVERAGE IN THE NORTH
SECTION BUT LESS COVERAGE IN THE REST OF THE AREA DURING THE
AFTERNOON INTO THE EVENING. BASED ON THE INITIAL DRYNESS AND
LINGERING UPPER RIDGING THUNDERSTORM COVERAGE MAY REMAIN LIMITED.
WE FORECASTED THE HIGHER CHANCE IN THE NORTH PART BASED ON THE
HIGH-RESOLUTION MODELS AND MORE PRONOUNCED INFLUENCE OF THE MID-
LEVEL SHORTWAVE TROUGH. THE NAM INDICATED SURFACE-BASED LI/S -6 TO
-7 TODAY. THE MODERATE INSTABILITY WITH AN INVERTED-V TYPE
SOUNDING INDICATES A POSSIBILITY OF DAMAGING WIND WITH A FEW OF
THE THUNDERSTORMS. LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE
BASED ON THE DRY ENVIRONMENT AND RECENT BIAS.
THUNDERSTORM COVERAGE SHOULD DIMINISH TONIGHT WITH THE LOSS OF
HEATING. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MODELS DISPLAY A LEE-SIDE TROUGH IN THE FORECAST AREA. STRONG
HEATING WITH CONVERGENCE INTO THIS FEATURE SUPPORTS THUNDERSTORMS...
BUT UPPER RIDGING EXTENDING INTO THE AREA FROM THE WEST SHOULD
LIMIT COVERAGE. USED THE GUIDANCE CONSENSUS FOR THE POP FORECAST.
THE GUIDANCE WAS CLOSE WITH THE TEMPERATURES. IT WILL REMAIN HOT
WITH HIGHS NEAR 100 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MEDIUM-RANGE MODELS DISPLAY UPPER-LEVEL RIDGING ALONG THE
SOUTHERN TIER OF THE NATION BUT THE RIDGING APPEARS SOMEWHAT
WEAKER OVER THE FORECAST AREA. THE MODELS SHOW LEE-SIDE TROUGHING
DURING MUCH OF THE PERIOD. A PRE-FRONTAL TROUGH OR FRONT MAY ALSO
STALL NEAR THE AREA DURING THE MIDDLE OF THE WEEK. THE PATTERN
SUPPORTS ABOVE NORMAL TEMPERATURES WITH SCATTERED THUNDERSTORMS.
THE GFS...ECMWF...AND EKD MOS HAVE TEMPERATURES MAINLY 4 TO 8
DEGREES ABOVE NORMAL WITH POPS 10 TO 40 PERCENT DURING THE PERIOD.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
EXPECTED STRATUS AND LIGHT FOG 09Z-14Z IMPROVING TO VFR BY 16Z.
WINDS WILL BE LIGHT AND VARIABLE IN WEAK PRESSURE PATTERN ALTHOUGH A
WEAK SURFACE TROUGH MAY DEVELOP OVER THE MIDLANDS BY THIS AFTERNOON.
MODELS INDICATING SCATTERED CONVECTION DEVELOPING LATER THIS
AFTERNOON...BUT LOW CONFIDENCE IN TIMING AND AREAL COVERAGE SO WILL
LEAVE OUT OF TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BRIEF MVFR/IFR POSSIBLE SUNDAY THROUGH
WEDNESDAY IN DIURNALLY DRIVEN CONVECTION. FOG/STRATUS POSSIBLE EACH
MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1051 AM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1051 AM CDT SAT JUL 18 2015
MCS THAT DEVELOPED OVER SOUTHEAST NEBRASKA/NORTHWEST MISSOURI
EARLIER THIS MORNING CONTINUES TO TRACK EASTWARD AND IS NOW
APPROACHING THE MISSISSIPPI RIVER. IR SATELLITE HAS SHOWN WARMING
CLOUD TOPS WHILE 15-MINUTE LIGHTNING DATA HAS BEEN CONSISTENTLY
DECREASING OVER THE PAST COUPLE OF HOURS. DESPITE THE DISTINCT
DIURNAL WEAKENING TREND...LIGHT RAIN IS SPILLING INTO WEST-CENTRAL
ILLINOIS. MOST MODELS ARE NOT HANDLING THE CURRENT SITUATION
PARTICULARLY WELL...WITH THE 12Z NAM SHOWING THE SYSTEM COMPLETELY
DISSIPATING BEFORE IT REACHES CENTRAL ILLINOIS. MEANWHILE...THE
LATEST HRRR TAKES THE DIMINISHING PRECIP AREA INTO THE HEART OF
THE KILX CWA EARLY THIS AFTERNOON...WITH WIDELY SCATTERED
THUNDERSTORMS DEVELOPING AHEAD OF THE SYSTEM ACROSS EAST-CENTRAL
AND SOUTHEAST ILLINOIS. THINK THIS MAY BE A LITTLE TOO
AGGRESSIVE...SO HAVE FOLLOWED THE RAPID REFRESH MOST CLOSELY FOR
THE SHORT-TERM FORECAST. AS A RESULT...HAVE INCREASED POPS ACROSS
THE W/SW CWA GENERALLY WEST OF THE I-55 CORRIDOR LATE THIS MORNING
INTO THE EARLY AFTERNOON AS THE SYSTEM CROSSES THE MISSISSIPPI
RIVER. THINK IT WILL GRADUALLY FIZZLE...LEAVING BEHIND A MID/HIGH
OVERCAST THROUGH MID-AFTERNOON. FURTHER E/SE...THINK ISOLATED
THUNDERSTORMS WILL DEVELOP ALONG/E OF I-57 THIS AFTERNOON AS
OUTFLOW BOUNDARY INTERACTS WITH VERY UNSTABLE AIRMASS. MAIN STORY
TODAY WILL BE THE HEAT AND HUMIDITY. DESPITE CLOUD COVER FROM MCS
TEMPORARILY HALTING THE TEMP RISE LATE THIS MORNING INTO THE EARLY
AFTERNOON ACROSS THE WESTERN HALF OF THE AREA...A RETURN TO
PARTIAL SUNSHINE LATER IN THE DAY WILL RESULT IN HIGH TEMPS IN THE
LOWER TO MIDDLE 90S ACROSS THE BOARD. HEAT INDEX VALUES WILL
EXCEED ADVISORY CRITERIA...RANGING FROM 105 TO 110.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT JUL 18 2015
OTHER THAN THE POSSIBILITY FOR A BRIEF PERIOD OF MVFR VSBYS IN
FOG/HZ OVER THE NEXT COUPLE OF HOURS...VFR CONDITIONS ARE EXPECTED
FOR THE REMAINDER OF THIS FORECAST PERIOD. LARGE COMPLEX OF
THUNDERSTORMS TRACKING EAST OVER SOUTHERN WISCONSIN ARE EXPECTED
TO REMAIN NORTH OF THE TAF SITES THIS MORNING. HOWEVER...THE
OUTFLOW BOUNDARY ASSOCIATED WITH THE STORMS WILL PUSH ACROSS
PARTS OF NORTHERN AND NORTHEAST ILLINOIS AND MAY PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT LATER TODAY. IN ADDITION...A MUCH
SMALLER AREA OF SHOWERS WAS LOCATED OVER WEST CENTRAL MISSOURI
WITH MODELS SUGGESTING A DECREASE IN AREAL COVERAGE AS THE
SHOWERS APPROACH EASTERN MISSOURI.
WE SHOULD SEE AT LEAST SCATTERED CUMULUS DEVELOP BY LATE MORNING
WITH A FEW OF THE FORECAST SOUNDINGS SUGGESTING SCT-BKN CIGS AT
BMI AND CMI. HOWEVER...RAP SOUNDINGS AND TIME HEIGHT CROSS
SECTIONS DO NOT INDICATE THE DEPTH OF THE MOISTURE TO BE THAT
SIGNIFICANT TODAY...SO WILL CARRY SCATTERED CU WITH BASES IN
THE 3000-4000 FOOT RANGE WITH SOME SCT-BKN CIRRUS ABOVE THE
CUMULUS. MAY SEE A COMPLEX OF STORMS DEVELOP LATE TODAY ALONG
THE AFOREMENTIONED REMNANT OUTFLOW BOUNDARY WITH THE STORMS THEN
FORECAST TO SHIFT SOUTH-SOUTHEAST. HOWEVER...THAT SCENARIO THIS
FAR OUT IS A LOW CONFIDENCE FORECAST SO WILL ONLY CARRY A VCTS
ACROSS THE NORTH AFTER 22Z.
SURFACE WINDS TODAY WILL BE FROM THE SOUTH TO SOUTHWEST AT 10 TO
15 KTS WITH AN OCCASIONAL GUST UP TO 20 KTS POSSIBLE DURING THE
AFTERNOON. SOUTH WINDS ARE EXPECTED TONIGHT AT 7 TO 12 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ044>046-054>057-
061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
UPDATE...BARNES
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
957 AM CDT SAT JUL 18 2015
.UPDATE...
957 AM CDT
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.SHORT TERM...
408 AM CDT
TODAY THROUGH SUNDAY...
HEAT...HUMIDITY AND TIMING/COVERAGE OF THUNDERSTORMS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM PERIOD.
A VERY WARM AND HUMID AIR MASS REMAINS IN PLACE ACROSS THE
FORECAST AREA EARLY THIS MORNING...WITH LOW LEVEL THERMAL RIDGE TO
BUILD INTO THE REGION TODAY ON PERSISTENT SOUTH-SOUTHWEST LOW
LEVEL FLOW. LOW LEVEL THERMAL PROGS FROM VARIOUS MODELS SUPPORT
AFTERNOON TEMPS IN THE LOW-MID 90S ACROSS THE CWA...WITH DEW
POINTS IN THE MID-UPPER 70S EXPECTED TO YIELD PEAK AFTERNOON HEAT
INDICES IN THE 105-110 DEGREE RANGE. A HEAT ADVISORY REMAINS IN
EFFECT FOR THE ENTIRE CWA WITH NO CHANGES AT THIS TIME.
SOME COMPLICATIONS EXIST WITH THE FORECAST HOWEVER...PRIMARILY
WITH THE POTENTIAL FOR OUTFLOW FROM MCS CURRENTLY TRACKING ACROSS
WISCONSIN AND ALSO WITH THE POTENTIAL FOR THUNDERSTORMS ACROSS
PORTIONS OF THE CWA TODAY. CONVECTION-ALLOWING GUIDANCE HAS NOT
BEEN HANDLING THE UPPER MIDWEST MCS VERY WELL OVERNIGHT...THOUGH
SOME MODELS PARTICULARLY THE 00Z ARW/NMM-EAST RUNS DO DEPICT A
SOMEWHAT SIMILAR BOWING MCS ACROSS WI...TURNING IT SOUTHEAST A BIT
ACROSS LAKE MICHIGAN THIS MORNING. THIS SEEMS FAIRLY
REASONABLE...AS SPC MESOANALYSIS DEPICTS AN MUCAPE AXIS OF
2000-4000 J/KG FROM THE UPPER MISSISSIPPI VALLEY SOUTHEAST INTO
NORTHERN IL AT 08Z...REASONABLY STEEP MID-LEVEL LAPSE RATES...AND
A 850-300 MB THICKNESS GRADIENT WHICH WOULD FAVOR A SOUTHEASTWARD
PROPAGATION. THE QUESTION IS HOW FAR SOUTH CONVECTION DEVELOPS
ALONG THE IL/WI BORDER AREA THIS MORNING...AND HOW MUCH OF AN
EFFECT OUTFLOW BOUNDARIES NOTED ACROSS EASTERN IA AND LIKELY FROM
SOUTHERN WI WILL HAVE ON OUR TEMP AND DEW POINT TRENDS TODAY.
CURRENT THINKING IS THAT SCATTERED STORMS ALONG SOUTHERN PERIPHERY
OF THE MCS MAY SCRAPE ALONG THE IL/WI BORDER AREA EARLY THIS
AM...MOVING EAST OF THE THE AREA BY MID-LATE MORNING WHICH SHOULD
ALLOW DISSIPATION OF HIGH CLOUDS AND RECOVERY OF TEMPS AND DEW
POINTS BACK INTO FORECAST RANGE THIS AFTERNOON.
ADDITIONAL THUNDERSTORMS ARE EXPECTED BY THIS EVENING...AS A COLD
FRONT TRAILING FROM LOW PRESSURE OVER ONTARIO APPROACHES AND
EVENTUALLY PASSES ON SUNDAY. WHILE MOST GUIDANCE DEPICTS A
SCENARIO OF STORMS INITIATING ALONG/AHEAD OF THE FRONT ACROSS
WISCONSIN AND IOWA THIS AFTERNOON AND MOVING INTO THE AREA THIS
EVENING... LINGERING OUTFLOW BOUNDARIES MAY PROVIDE FOCUS FOR
ISOLATED TO SCATTERED STORMS TO DEVELOP OVER PORTIONS OF THE AREA
THIS AFTERNOON. ONE POSSIBLE FOCUS WOULD BE THE OUTFLOW BOUNDARY
FROM THIS MORNINGS MCS...WHICH WILL LIKELY BE SOMEWHERE OVER FAR
NORTHERN IL THIS AFTERNOON. THUS HAVE ADDED SOME CHANCE POPS BY
EARLY THIS AFTERNOON ACROSS NORTHERN IL. THUNDERSTORM CHANCES WILL
CONTINUE TONIGHT AS THE FRONT MOVES SLOWLY INTO THE REGION...AS
WELL AS ON SUNDAY AS THE BOUNDARY SAGS SOUTH AND EVENTUALLY
SETTLES SOUTH OF THE AREA SUNDAY EVENING. THE WARM/MOIST AIR
MASS...COMBINED WITH OUR LOCATION ALONG THE SOUTHERN PERIPHERY OF
FASTER WESTERLY FLOW ALOFT...WILL SET THE STAGE FOR THE POTENTIAL
FOR SEVERE THUNDERSTORMS MAINLY THIS AFTERNOON/EVENING...AND AGAIN
SUNDAY AFTERNOON. THE ENTIRE CWA IS IN SPC DAY 1 SLIGHT RISK...AND
A DAY 2 SLIGHT RISK MAINLY ACROSS THE SOUTHERN HALF. DAMAGING
WINDS WILL BE THE PRIMARY SEVERE HAZARD...THOUGH LOCALLY BACKED
WINDS ALONG OUTFLOW BOUNDARIES WOULD PRESENT A LOW TORNADO RISK AS
WELL. HIGH PWAT AIRMASS WILL CONTINUE TO PRODUCE TORRENTIAL
RAINFALL AND POTENTIAL FLOODING WITH STORMS AS WELL.
RATZER
&&
.LONG TERM...
415 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
FRONT SLIPS SOUTH OF AREA SUNDAY NIGHT WITH THUNDERSTORM THREAT
ENDING FROM NORTH TO SOUTH DURING THE EVENING ACROSS THE SOUTHEAST
HALF OF THE FORECAST AREA. WEAK HIGH PRESSURE SPREADS ACROSS CENTRAL
IL AND IN BEHIND THE FRONT LATER SUNDAY NIGHT.
FAST WEST-NORTHWEST FLOW ALOFT CONTINUES HOWEVER...WITH A SHORT WAVE
PROGGED TO DIG ACROSS THE WESTERN LAKES AREA MONDAY NIGHT INTO
TUESDAY MORNING...WITH THE PASSAGE OF ANOTHER WEAKER COLD FRONT.
WEAK RETURN FLOW SETS UP MONDAY NIGHT...WITH GUIDANCE SHOWING QUITE
A BIT OF SPREAD IN TIMING AND COVERAGE OF PRECIP INTO TUESDAY. HAVE
MAINTAINED SLIGHT CHANCE POPS DURING THE DAY TUESDAY FROM PREVIOUS
FORECAST FOR NOW WITH HOPEFULLY BETTER MODEL AGREEMENT IN THE
DETAILS AS THE PERIOD DRAWS NEARER.
SURFACE HIGH PRESSURE ONCE AGAIN BUILDS INTO THE AREA TUESDAY NIGHT
AND WEDNESDAY...AS UPPER RIDGE BEGINS TO REBUILD ACROSS THE CENTRAL
CONUS. THIS LOOKS TO PROVIDE A DRY MID-WEEK PERIOD WITH
NEAR/SLIGHTLY BELOW NORMAL TEMPS GENERALLY IN THE LOW 80S. MEDIUM
RANGE GUIDANCE ARE THEN IN DECENT AGREEMENT IN BRINGING A SHORT WAVE
THROUGH THE RIDGE AND ACROSS THE MIDWEST THURSDAY...WITH RETURN FLOW
AND THE NEXT CHANCE OF SHOWER/THUNDERSTORMS DEVELOPING IN ADVANCE AS
THE SURFACE HIGH MOVES OFF TO THE EAST.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE/GUST FRONT SHIFTS WINDS TO NE WITH A BRIEF PERIOD OF
GUSTS TO 16 KT AT ORD ARND 1430Z. BRIEF PERIOD OF MVFR CIGS
BEHIND THE WIND SHIFT. LOW CONFIDENCE IN A WIND SHIFT AT MDW.
* GUSTY SW WINDS WITH GUSTS ARND 20 KT THIS AFTN.
* TSRA IS PSBL THIS AFTN AND AGAIN THIS EVENING WITH SHRA
OVERNIGHT INTO SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 12Z...
A GUST FRONT FROM THE CONVECTION OVER WI IS SHIFTING SOUTH THROUGH
NORTHERN IL. IT APPEARED TO BE WEAKENING UNTIL A LAKE BREEZE
COMPONENT MERGED WITH IT AND BROUGHT IT BACK TO LIFE. WINDS AT PWK
BRIEFLY TURNED TO 03009G16KT SO THINKING ORD WILL SEE A BRIEF
PERIOD OF GUSTY NE WINDS. THINKING THE BOUNDARY SHOULD WEAKEN
BEFORE IT REACHES MDW AND GYY. THIS BOUNDARY WILL LIKELY BE THE
FOCUS FOR TSRA THIS AFTN SO PUT A TEMPO IN ALL OF THE TAFS FOR
TSRA EARLY THIS AFTN. HAVE MEDIUM CONFIDENCE IN
TIMING...COVERAGE...AND OCCURRENCE AND PLAN TO GET MORE SPECIFIC
IN TIME IN FUTURE UPDATES AS CONDITIONS IMPROVE AND CONFIDENCE
INCREASES.
PREVIOUS DISCUSSION...12Z...
A MESSY FORECAST SITUATION TODAY WITH LOTS OF POTENTIAL PITFALLS.
THE GENERAL PATTERN OF SSWLY-SWLY FLOW IN A VERY WARM/MOIST/
UNSTABLE AIRMASS. DEEPER LAYER MIXING TODAY SHOULD ALLOW STRONG
WINDS TO REACH THE SFC...WITH PREVAILING GUSTS OF 15-20KT.
HOWEVER...IT IS THE FINER SCALE DETAILS THAT HAVE THE POTENTIAL TO
BRING QUICK CHANGES. TWO WELL DEFINED OUTFLOW BOUNDARIES ARE
APPROACHING THE REGION...ONE MOVING EWD THROUGH ERN IOWA AND
ANOTHER DROPPING SEWD THROUGH SRN WISCONSIN. THE OUTFLOW BOUNDARY
DROPPING OUT OF WISCONSIN WILL BE THE INITIAL CONCERN. TIMING THE
BOUNDARY FROM THE LATEST RADAR IMAGERY SUGGESTS THAT IT COULD MOVE
THROUGH RFD AT ARND 13Z AND THR CHICAGO AREA ARND 14Z...SHOULD IT
HOLD TOGETHER. GIVEN THAT UNCERTAINTY...HAVE NOT TRIED TO TIME IT
IN THE LATEST TAF ISSUANCE...BUT THERE IS THE POTENTIAL FOR AN
ABRUPT WIND SHIFT TO NWLY WITH GUSTS TO 30KT.
THERE ALSO CONTINUES TO BE OCNL SCT SHRA/TSRA DEVELOPMENT IN THE
WARM ADVECTION ZONE AHEAD OF THE APPROACHING COLD FRONT. THERE
WILL BE THE POTENTIAL FOR ISOLD ACTIVITY THROUGH THE DAY TODAY
GIVEN THE UNSTABLE ENVIRONMENT. THE ADDITION OF MULTIPLE OUTFLOW
BOUNDARIES LEFT FROM YESTERDAYS ACTIVITY OVER THE REGION AS WELL
AS NEW BOUNDARIES MOVING INTO THE REGION WILL KEEP THE POTENTIAL
FOR ADDITIONAL TSRA TODAY...THOUGH CONFIDENCE IN TIMING...COVERAGE
AND LOCATION IS HIGHLY UNCERTAIN AND MUCH TOO LOW TO TRY AND PIN
DOWN IN THE TAFS AT THIS TIME.
THERE IS A LITTLE BETTER CONFIDENCE IN MORE WIDESPREAD...ORGANIZED
SHRA AND TSRA TONIGHT THIS EVENING AND TONIGHT WITH THE FRONTAL
PASSAGE. WHILE THERE IS STILL SOME TIMING DIFFERENCES AMONG THE
MODEL GUIDANCE AS TO THE EXACT TIMING OF THE FRONT...THE MOST
FAVORABLE TIME FOR MORE ORGANIZED ACTIVITY WILL BE THROUGH THE
EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN WINDS FOLLOWING LAKE BREEZE/GUST FRONT
AT ORD...LOW CONFIDENCE IN HOW LONG NE GUSTS WILL LAST AND HOW
LONG IT WILL TAKE TO GET BACK TO GUSTY SW WINDS. LOW CONFIDENCE
IN A WIND SHIFT AT MDW.
* MEDIUM CONFIDENCE IN TSRA TIMING...OCCURRENCE AND COVERAGE THIS
AFTN.
* MEDIUM CONFIDENCE ON TS DETAILS ASSOCIATED WITH THE COLD FRONT
MOVING THROUGH THE REGION THIS EVENING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
8 PM SATURDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ020-ILZ022 UNTIL 8 PM SATURDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
607 AM CDT SAT JUL 18 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT JUL 18 2015
OTHER THAN THE POSSIBILITY FOR A BRIEF PERIOD OF MVFR VSBYS IN
FOG/HZ OVER THE NEXT COUPLE OF HOURS...VFR CONDITIONS ARE EXPECTED
FOR THE REMAINDER OF THIS FORECAST PERIOD. LARGE COMPLEX OF
THUNDERSTORMS TRACKING EAST OVER SOUTHERN WISCONSIN ARE EXPECTED
TO REMAIN NORTH OF THE TAF SITES THIS MORNING. HOWEVER...THE
OUTFLOW BOUNDARY ASSOCIATED WITH THE STORMS WILL PUSH ACROSS
PARTS OF NORTHERN AND NORTHEAST ILLINOIS AND MAY PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT LATER TODAY. IN ADDITION...A MUCH
SMALLER AREA OF SHOWERS WAS LOCATED OVER WEST CENTRAL MISSOURI
WITH MODELS SUGGESTING A DECREASE IN AREAL COVERAGE AS THE
SHOWERS APPROACH EASTERN MISSOURI.
WE SHOULD SEE AT LEAST SCATTERED CUMULUS DEVELOP BY LATE MORNING
WITH A FEW OF THE FORECAST SOUNDINGS SUGGESTING SCT-BKN CIGS AT
BMI AND CMI. HOWEVER...RAP SOUNDINGS AND TIME HEIGHT CROSS
SECTIONS DO NOT INDICATE THE DEPTH OF THE MOISTURE TO BE THAT
SIGNIFICANT TODAY...SO WILL CARRY SCATTERED CU WITH BASES IN
THE 3000-4000 FOOT RANGE WITH SOME SCT-BKN CIRRUS ABOVE THE
CUMULUS. MAY SEE A COMPLEX OF STORMS DEVELOP LATE TODAY ALONG
THE AFOREMENTIONED REMNANT OUTFLOW BOUNDARY WITH THE STORMS THEN
FORECAST TO SHIFT SOUTH-SOUTHEAST. HOWEVER...THAT SCENARIO THIS
FAR OUT IS A LOW CONFIDENCE FORECAST SO WILL ONLY CARRY A VCTS
ACROSS THE NORTH AFTER 22Z.
SURFACE WINDS TODAY WILL BE FROM THE SOUTH TO SOUTHWEST AT 10 TO
15 KTS WITH AN OCCASIONAL GUST UP TO 20 KTS POSSIBLE DURING THE
AFTERNOON. SOUTH WINDS ARE EXPECTED TONIGHT AT 7 TO 12 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
ILZ044>046-054>057-061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1036 AM EDT SAT JUL 18 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 344 AM EDT SAT JUL 18 2015
A STRONG UPPER LEVEL RIDGE NOSING INTO THE AREA WILL MAKE FOR THE
HOTTEST DAY OF THE YEAR THUS FAR ACROSS CENTRAL INDIANA...WITH
HIGH TEMPERATURES IN THE LOW TO MID 90S AND HEAT INDEX VALUES IN
THE MID 100S. THE VERY HOT AND HUMID AIRMASS MAY ALLOW FOR
THUNDERSTORM DEVELOPMENT IN THE HEAT OF THE DAY ALONG REMNANT
BOUNDARIES FROM PRIOR CONVECTION. A MORE ORGANIZED FRONTAL SYSTEM
WILL APPROACH FROM THE NORTHWEST LATE TONIGHT AND DROP THROUGH THE
AREA SUNDAY INTO SUNDAY NIGHT...WITH STORMS LIKELY. THIS FRONTAL
BOUNDARY WILL BRING TEMPERATURES CLOSER TO NORMAL NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 18 2015
.UPDATE...DROPPED TEMPERATURES SLIGHTLY SOME AREAS BASED ON CURRENT
TEMPERATURES AND WET GROUND. HOWEVER LOWER 90S WITH HEAT INDEX VALUES
FROM 101 TO 107 STILL LOOK GOOD. RAP SOUNDINGS LOOK MOSTLY CAPPED...
BUT I WOULD NOT RULE OUT AN ISOLATED THUNDERSTORM. NO OTHER UPDATES
ARE NEEDED AT THIS TIME.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HEIGHTS RISE ACROSS THE AREA TODAY AS THE RIDGE STRENGTHENS TO OUR
SOUTH...BUT WITH RESIDUAL BOUNDARIES FROM PRIOR CONVECTION AND A
VERY HOT AND HUMID AIRMASS IN PLACE...WITH DEWPOINTS WELL INTO THE
70S...WILL HAVE TO CARRY AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON AND EVENING. OTHERWISE HEAT IS THE SIGNIFICANT
FORECAST VARIABLE.
CONSENSUS NUMBERS HAVE BEEN RUNNING COOL LATELY AND THIS LOOKS TO
BE THE CASE AGAIN. HAVE BUMPED THEM UP AT LEAST A COUPLE OF
DEGREES...AND EXPECT HIGHS TO REACH THE LOW TO MID 90S ACROSS THE
AREA. COUPLED WITH THE EXTREMELY HIGH DEWPOINTS...HEAT INDEX
VALUES WILL LIKELY REACH THE MID 100S. THIS IS COVERED WELL BY
PREVIOUSLY ISSUED HEAT ADVISORY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 344 AM EDT SAT JUL 18 2015
STORMS FROM PEAK HEATING MAY LINGER INTO THE EVENING...AND THEN
ACROSS THE NORTH WILL REQUIRE POPS LATE TONIGHT AS THE FRONT
BEGINS TO APPROACH THE AREA. LIKELY POPS WILL BE REQUIRED SUNDAY
INTO SUNDAY NIGHT AS THIS BOUNDARY DROPS THROUGH THE AREA. AREA IS
OUTLOOKED DAY 2 AND THIS APPEARS REASONABLE. CHANCE POPS WILL BE
REQUIRED ACROSS THE SOUTH ON MONDAY NEARER THE LINGERING FRONTAL
BOUNDARY...AND THEN ACROSS THE ENTIRE AREA MONDAY NIGHT AS AN
UPPER LEVEL WAVE APPROACHES AND THE BOUNDARY BEGINS TO SHIFT BACK
NORTH.
CONSENSUS NUMBERS CONTINUE TO RUN COOL ON MAX TEMPS AND HAVE
ADJUSTED ACCORDINGLY. MIN TEMPS APPEAR MORE REASONABLE.
TEMPERATURES WILL BEGIN A GRADUAL RETURN TO MORE NORMAL NUMBERS
TOWARD THE END OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 334 AM EDT SAT JUL 18 2015
UPPER RIDGE WILL RECENTER OVER THE HIGH PLAINS EARLY IN THE PERIOD
BEFORE SHIFTING BACK EAST AND EXPANDING INTO THE MISSISSIPPI
VALLEY BY NEXT WEEKEND AS AN UPPER LOW SHIFTS EAST INTO THE
CANADIAN MARITIMES. THIS WILL KEEP THE REGION ON THE RIDGE
PERIPHERY WITHIN A NORTHWEST FLOW PATTERN WITH AT LEAST A FEW
OPPORTUNITIES FOR STORMS.
GOOD CHANCE FOR SCATTERED STORMS TUESDAY WITH THE FRONTAL
BOUNDARY DROPPING SOUTH THROUGH THE OHIO VALLEY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT AND SHOULD PROVIDE AT LEAST A BRIEF
BREAK FROM THE STORMY WEATHER MIDWEEK. CONVECTIVE CHANCES WILL
RETURN THURSDAY AND FRIDAY AS A WARM FRONT APPROACHES FROM THE
WEST. APPEARS NOW THE POTENTIAL FOR HOTTER TEMPERATURES WILL HOLD
OFF UNTIL THE WEEKEND...WITH HIGHS PRIMARILY IN THE 80S THROUGH
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 181200Z TAF ISSUANCE/...
ISSUED AT 1034 AM EDT SAT JUL 18 2015
1430Z UPDATE...NO CHANGES ARE NEEDED AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.
VFR CONDITIONS ANTICIPATED FOR MUCH OF THE FORECAST PERIOD. MVFR
VISIBILITIES POSSIBLE LATE TONIGHT AT KLAF.
STILL HAVE POCKETS OF STRATOCU LINGERING UNDERNEATH CIRRUS
STREAMING INTO THE REGION FROM THE NORTH AND WEST. SHOULD SEE
STRATOCU MIX AND LIFT INTO A SCATTERED VFR CU FIELD BY MIDDAY WITH
SOME HIGHER CLOUDS. CONVECTIVE POTENTIAL LOOKS LOWER DURING THE
DAYLIGHT HOURS AS RIDGING ALOFT AND MID LEVEL TEMPERATURES BOTH
INCREASE THROUGH THE DAY. WITH STRONG INSTABILITY PRESENT ACROSS
CENTRAL INDIANA...EXPECT ISOLATED CONVECTION WILL DEVELOP DURING
PEAK HEATING IN THE AFTERNOON AND EVENING. W/SW WINDS WILL PEAK AT
10-15KTS THIS AFTERNOON.
EVEN LOWER UNCERTAINTY FOR TONIGHT WITH RESPECT TO POTENTIAL
IMPACTS FROM LARGER CONVECTIVE CLUSTER EXPECTED TO DEVELOP OVER
THE WESTERN GREAT LAKES BY EARLY EVENING. WRF GUIDANCE TRACKING
THIS ACTIVITY INTO THE NORTHERN FORECAST AREA BEFORE WEAKENING
TONIGHT WHICH LOOKS ENTIRELY PLAUSIBLE CONSIDERING STEERING
CURRENTS ALOFT. HIGHEST CONFIDENCE IN IMPACTS AT KLAF AND HAVE
INTRODUCED A VCTS MENTION AFTER 06Z. COULD SEE STORMS TRACK
FURTHER INTO THE AREA LATE TONIGHT AND IMPACT THE OTHER THREE
SITES...BUT CONFIDENCE IN THIS OCCURRING IS LOW WITH HIGHER
HEIGHTS AND WARMER AIR ALOFT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JH
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...SMF/RYAN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1021 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 116 AM EDT SAT JUL 18 2015
TODAY WILL BE VERY HOT AND HUMID ACROSS THE REGION. TEMPERATURES
WILL QUICKLY WARM INTO THE 80S THIS MORNING AND LOWER TO MIDDLE
90S THIS AFTERNOON. IT WILL BE VERY MUGGY AND THIS WILL MAKE IT
FEEL LIKE 100 TO 110 THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
A LATE AFTERNOON THUNDERSTORM BUT BETTER CHANCES TONIGHT AND
SUNDAY. IT WILL REMAIN WARM AND MUGGY TONIGHT WITH TEMPERATURES
STAYING IN THE 80S THIS EVENING AND LOWS ONLY IN THE 70S
OVERNIGHT.
&&
.UPDATE...
ISSUED AT 1013 AM EDT SAT JUL 18 2015
MAIN ADJUSTMENT W/ THIS FCST UPDATE IS TO INCREASE POPS ACROSS SRN
LWR MI AND FAR NE IN/NW OH THROUGH EARLY AFTN...AS WEAKENING MCS
DROPS SOUTHEAST FROM LK MI THIS MORNING. HI-RES MODEL GUIDANCES
DOING A VERY POOR JOB HANDLING THE EVOLUTION OF THIS
LINE...HOWEVER RADAR TRENDS SUGGEST IT WILL HOLD TOGETHER IN SOME
FORM INTO THE NORTHERN PART OF THE FCST AREA. SEVERE THREAT LOOKS
LOW AT THIS POINT...WITH RECENT UPSTREAM OBS SUGGESTING WIND
GUSTS AROUND 30 TO 40 MPH OVER THE LAST HOUR OR SO.
BIGGER CHALLENGE WILL BE THE IMPACT OF THIS LINE OF STORMS AND ITS
ATTENDANT OUTFLOW ON AFTN POPS...AS AIRMASS ACROSS NRN IN BECOMES
INCREASINGLY UNSTABLE INTO THE AFTN. FOR NOW...CONTINUED WITH
ISO/SLIGHT CHANCE MENTION THROUGH THE AFTN...WITH A SLIGHTLY
HIGHER POP NOTED ALONG/NORTH OF US 6...WHERE OUTFLOW IS EXPECTED
TO ANCHOR. ANOTHER CHALLENGE THE IMPACT OF THESE STORMS ON AFTN HI
TEMPS/HEAT INDICES. FOR NOW...MADE NO MAJOR CHANGES TO
TEMPS...ALTHOUGH DIURNAL HEATING WILL BE SLOWED/DELAYED WITH THIS
PRECIP AND CLOUD COVER...ESPECIALLY NORTH OF US 6. WILL CONTINUE
TO MONITOR TEMPERATURE AND CONVECTIVE TRENDS THROUGH THE MORNING
AND MAKE ADJUSTMENTS TO THE FCST THROUGHOUT THE DAY AS NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 637 AM EDT SAT JUL 18 2015
VFR CONDITIONS TO START THE PERIOD BUT UNCERTAINTY WITH TSRA
CHANCES THIS AFTERNOON AND OVERNIGHT. STRONG CAP EXPECTED TODAY
WITH HEAT BUT OUTFLOW BOUNDARIES FROM UPSTREAM CONVECTION AS WELL
AS POSSIBLE CONVECTIVELY INDUCED SHORT WAVE COULD BE ENOUGH TO
WEAKEN CAP LATE AFTERNOON AND EVENING WITH PLENTY OF INSTABILITY
FOR STRONG TSRA DEVELOPMENT. LOW CONFIDENCE IN COVERAGE...TIMING
AND LOCATION SO DID NOT ADD TSRA TO TAFS WITH THIS PACKAGE. KEPT
CONDITIONS VFR BUT MVFR AND IFR POSSIBLE WITH ANY TSRA THAT DO
DEVELOP.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
INZ003>009-012>018-020-022>027-032>034.
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ077>081.
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ001-002-004-005-
015-016-024-025.
LM...NONE.
&&
$$
UPDATE...NG
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1014 AM EDT SAT JUL 18 2015
.UPDATE... NEAR TERM FOR THE REST OF TODAY HAS BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 344 AM EDT SAT JUL 18 2015
A STRONG UPPER LEVEL RIDGE NOSING INTO THE AREA WILL MAKE FOR THE
HOTTEST DAY OF THE YEAR THUS FAR ACROSS CENTRAL INDIANA...WITH
HIGH TEMPERATURES IN THE LOW TO MID 90S AND HEAT INDEX VALUES IN
THE MID 100S. THE VERY HOT AND HUMID AIRMASS MAY ALLOW FOR
THUNDERSTORM DEVELOPMENT IN THE HEAT OF THE DAY ALONG REMNANT
BOUNDARIES FROM PRIOR CONVECTION. A MORE ORGANIZED FRONTAL SYSTEM
WILL APPROACH FROM THE NORTHWEST LATE TONIGHT AND DROP THROUGH THE
AREA SUNDAY INTO SUNDAY NIGHT...WITH STORMS LIKELY. THIS FRONTAL
BOUNDARY WILL BRING TEMPERATURES CLOSER TO NORMAL NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 18 2015
.UPDATE...DROPPED TEMPERATURES SLIGHTLY SOME AREAS BASED ON CURRENT
TEMPERATURES AND WET GROUND. HOWEVER LOWER 90S WITH HEAT INDEX VALUES
FROM 101 TO 107 STILL LOOK GOOD. RAP SOUNDINGS LOOK MOSTLY CAPPED...
BUT I WOULD NOT RULE OUT AN ISOLATED THUNDERSTORM. NO OTHER UPDATES
ARE NEEDED AT THIS TIME.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HEIGHTS RISE ACROSS THE AREA TODAY AS THE RIDGE STRENGTHENS TO OUR
SOUTH...BUT WITH RESIDUAL BOUNDARIES FROM PRIOR CONVECTION AND A
VERY HOT AND HUMID AIRMASS IN PLACE...WITH DEWPOINTS WELL INTO THE
70S...WILL HAVE TO CARRY AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON AND EVENING. OTHERWISE HEAT IS THE SIGNIFICANT
FORECAST VARIABLE.
CONSENSUS NUMBERS HAVE BEEN RUNNING COOL LATELY AND THIS LOOKS TO
BE THE CASE AGAIN. HAVE BUMPED THEM UP AT LEAST A COUPLE OF
DEGREES...AND EXPECT HIGHS TO REACH THE LOW TO MID 90S ACROSS THE
AREA. COUPLED WITH THE EXTREMELY HIGH DEWPOINTS...HEAT INDEX
VALUES WILL LIKELY REACH THE MID 100S. THIS IS COVERED WELL BY
PREVIOUSLY ISSUED HEAT ADVISORY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 344 AM EDT SAT JUL 18 2015
STORMS FROM PEAK HEATING MAY LINGER INTO THE EVENING...AND THEN
ACROSS THE NORTH WILL REQUIRE POPS LATE TONIGHT AS THE FRONT
BEGINS TO APPROACH THE AREA. LIKELY POPS WILL BE REQUIRED SUNDAY
INTO SUNDAY NIGHT AS THIS BOUNDARY DROPS THROUGH THE AREA. AREA IS
OUTLOOKED DAY 2 AND THIS APPEARS REASONABLE. CHANCE POPS WILL BE
REQUIRED ACROSS THE SOUTH ON MONDAY NEARER THE LINGERING FRONTAL
BOUNDARY...AND THEN ACROSS THE ENTIRE AREA MONDAY NIGHT AS AN
UPPER LEVEL WAVE APPROACHES AND THE BOUNDARY BEGINS TO SHIFT BACK
NORTH.
CONSENSUS NUMBERS CONTINUE TO RUN COOL ON MAX TEMPS AND HAVE
ADJUSTED ACCORDINGLY. MIN TEMPS APPEAR MORE REASONABLE.
TEMPERATURES WILL BEGIN A GRADUAL RETURN TO MORE NORMAL NUMBERS
TOWARD THE END OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 334 AM EDT SAT JUL 18 2015
UPPER RIDGE WILL RECENTER OVER THE HIGH PLAINS EARLY IN THE PERIOD
BEFORE SHIFTING BACK EAST AND EXPANDING INTO THE MISSISSIPPI
VALLEY BY NEXT WEEKEND AS AN UPPER LOW SHIFTS EAST INTO THE
CANADIAN MARITIMES. THIS WILL KEEP THE REGION ON THE RIDGE
PERIPHERY WITHIN A NORTHWEST FLOW PATTERN WITH AT LEAST A FEW
OPPORTUNITIES FOR STORMS.
GOOD CHANCE FOR SCATTERED STORMS TUESDAY WITH THE FRONTAL
BOUNDARY DROPPING SOUTH THROUGH THE OHIO VALLEY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT AND SHOULD PROVIDE AT LEAST A BRIEF
BREAK FROM THE STORMY WEATHER MIDWEEK. CONVECTIVE CHANCES WILL
RETURN THURSDAY AND FRIDAY AS A WARM FRONT APPROACHES FROM THE
WEST. APPEARS NOW THE POTENTIAL FOR HOTTER TEMPERATURES WILL HOLD
OFF UNTIL THE WEEKEND...WITH HIGHS PRIMARILY IN THE 80S THROUGH
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 181200Z TAF ISSUANCE/...
ISSUED AT 710 AM EDT SAT JUL 18 2015
VFR CONDITIONS ANTICIPATED FOR MUCH OF THE FORECAST PERIOD. MVFR
VISIBILITIES POSSIBLE LATE TONIGHT AT KLAF.
STILL HAVE POCKETS OF STRATOCU LINGERING UNDERNEATH CIRRUS
STREAMING INTO THE REGION FROM THE NORTH AND WEST. SHOULD SEE
STRATOCU MIX AND LIFT INTO A SCATTERED VFR CU FIELD BY MIDDAY WITH
SOME HIGHER CLOUDS. CONVECTIVE POTENTIAL LOOKS LOWER DURING THE
DAYLIGHT HOURS AS RIDGING ALOFT AND MID LEVEL TEMPERATURES BOTH
INCREASE THROUGH THE DAY. WITH STRONG INSTABILITY PRESENT ACROSS
CENTRAL INDIANA...EXPECT ISOLATED CONVECTION WILL DEVELOP DURING
PEAK HEATING IN THE AFTERNOON AND EVENING. W/SW WINDS WILL PEAK AT
10-15KTS THIS AFTERNOON.
EVEN LOWER UNCERTAINTY FOR TONIGHT WITH RESPECT TO POTENTIAL
IMPACTS FROM LARGER CONVECTIVE CLUSTER EXPECTED TO DEVELOP OVER
THE WESTERN GREAT LAKES BY EARLY EVENING. WRF GUIDANCE TRACKING
THIS ACTIVITY INTO THE NORTHERN FORECAST AREA BEFORE WEAKENING
TONIGHT WHICH LOOKS ENTIRELY PLAUSIBLE CONSIDERING STEERING
CURRENTS ALOFT. HIGHEST CONFIDENCE IN IMPACTS AT KLAF AND HAVE
INTRODUCED A VCTS MENTION AFTER 06Z. COULD SEE STORMS TRACK
FURTHER INTO THE AREA LATE TONIGHT AND IMPACT THE OTHER THREE
SITES...BUT CONFIDENCE IN THIS OCCURRING IS LOW WITH HIGHER
HEIGHTS AND WARMER AIR ALOFT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JH
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
642 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 116 AM EDT SAT JUL 18 2015
TODAY WILL BE VERY HOT AND HUMID ACROSS THE REGION. TEMPERATURES
WILL QUICKLY WARM INTO THE 80S THIS MORNING AND LOWER TO MIDDLE
90S THIS AFTERNOON. IT WILL BE VERY MUGGY AND THIS WILL MAKE IT
FEEL LIKE 100 TO 110 THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
A LATE AFTERNOON THUNDERSTORM BUT BETTER CHANCES TONIGHT AND
SUNDAY. IT WILL REMAIN WARM AND MUGGY TONIGHT WITH TEMPERATURES
STAYING IN THE 80S THIS EVENING AND LOWS ONLY IN THE 70S
OVERNIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 637 AM EDT SAT JUL 18 2015
VFR CONDITIONS TO START THE PERIOD BUT UNCERTAINTY WITH TSRA
CHANCES THIS AFTERNOON AND OVERNIGHT. STRONG CAP EXPECTED TODAY
WITH HEAT BUT OUTFLOW BOUNDARIES FROM UPSTREAM CONVECTION AS WELL
AS POSSIBLE CONVECTIVELY INDUCED SHORT WAVE COULD BE ENOUGH TO
WEAKEN CAP LATE AFTERNOON AND EVENING WITH PLENTY OF INSTABILITY
FOR STRONG TSRA DEVELOPMENT. LOW CONFIDENCE IN COVERAGE...TIMING
AND LOCATION SO DID NOT ADD TSRA TO TAFS WITH THIS PACKAGE. KEPT
CONDITIONS VFR BUT MVFR AND IFR POSSIBLE WITH ANY TSRA THAT DO
DEVELOP.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY FROM NOON EDT /11 AM CDT/ TODAY TO 9 PM EDT /8 PM
CDT/ THIS EVENING FOR INZ003>009-012>018-020-022>027-
032>034.
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ077>081.
OH...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS JACKSON KY
925 AM EDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 925 AM EDT SAT JUL 18 2015
WENT AHEAD AND UPDATED THE POPS TO INCLUDE ISOLATED CHANCES ACROSS
THE BOARD BY THIS AFTERNOON. WHILE THERE IS NOTHING GOING ON
ACROSS THE CWA AT THE MOMENT...SHOWERS ARE ALREADY STARTING TO POP
JUST TO OUR NORTH...SO DIDN/T FEEL COMFORTABLE NOT INCLUDING SOME
POSSIBILITY THAT OUR NORTHERN CWA WOULD SEE SOME OF THIS SHOWER
ACTIVITY. STILL THINK THE BEST ACTIVITY WILL DEVELOP ACROSS THE
SOUTHWEST CWA CLOSER TO THE LOCATION OF THE BOUNDARY...SO UPPED
POPS HERE AS WELL TO HIGH END ISOLATED. OVERALL...STILL EXPECT IT
TO BE A VERY HIT AND MISS DAY WITH ONLY LIGHT ACCUMULATIONS
EXPECTED UNDER THE SHOWERS THAT DO DEVELOP. BUT GIVEN THE CURRENT
RADAR WITH SHOWERS POPPING UP AND THE LATEST HI RES
MODELS...WANTED TO GO AHEAD AND INCLUDE EVERYONE IN THE ISOLATED
POTENTIAL.
THAT BEING SAID...THIS UPDATE ALSO INCLUDED AN UPDATE TO THE SKY
COVER...ESPECIALLY FOR THE MORNING HOURS AS HIGH CLOUDS ARE
ALREADY STARTING TO BUILD ACROSS THE AREA. INCREASED CLOUD
COVERAGE THROUGH THE AFTERNOON...BUT CHANGES WERE ONLY
MINOR...WITH FORECAST GROUPS NOW READING PARTLY CLOUDY INSTEAD OF
MOSTLY SUNNY BY THIS AFTERNOON WHEN SOME OF THE DIURNAL CLOUDS
BEGIN DEVELOPING. THIS WAS SUPPORTED BY THE LATEST NAM12 FORECAST
SOUNDINGS...AS WELL AS THE LATEST GFS40 FORECAST SOUNDING...THOUGH
CLOUD LAYERS MAY BE A BIT THINNER ACCORDING TO THE GFS.
FINALLY...ADJUSTED TEMPERATURES FOR TODAY SLIGHTLY. EVEN IF SOME
CLOUD COVER DEVELOPS...DON/T THINK IT WILL HAMPER THE WARM UP TOO
MUCH. AS SUCH...COUNTIES IN THE SW OF THE CWA ARE ALREADY SHOOTING
TO NEAR AND ABOVE 80 DEGREES...AS ARE A FEW IN THE NE CWA. WENT
AHEAD AND BUMPED UP HIGH TEMPERATURES FOR THESE LOCATION A COUPLE
DEGREES HIGHER...TO AROUND 92 INSTEAD OF 90. THIS ALSO MATCHED UP
BETTER WITH THE NEIGHBORING OFFICES WHO HAVE LOW TO MID 90S
FORECAST. WILL CONTINUE TO MONITOR TEMPS THROUGHOUT THE DAY IN
CASE ANY MORE ADJUSTMENTS/UPDATES ARE NEEDED...AS HIGH HUMIDITY
VALUES WILL PLAY A ROLE IN SOME POTENTIALLY PROBLEMATIC HEAT
INDEXES ACROSS THE REGION.
UPDATE ISSUED AT 736 AM EDT SAT JUL 18 2015
LAST OF THE EARLY MORNING SHOWERS HAVE PUSHED OUT OF THE
REGION...WITH DRY WEATHER LIKELY SETTING IN FOR THE REST OF THE
MORNING. HRRR HAS BEEN CONSISTENT ON SHOWING SOME REDEVELOPMENT
ACROSS EASTERN KENTUCKY THROUGH THE MORNING HOURS...BUT HAVE SEEN
NO EVIDENCE OF THIS HAPPENING YET. THUS...WILL MAINTAIN DRY
WEATHER OVER THE NEXT SEVERAL HOURS...BEFORE BRING SOME ISOLATED
SHOWERS/STORMS BACK IN THIS AFTERNOON WITH PEAK HEATING. MAIN AREA
OF FOCUS WILL BE A LEFT OVER OUTFLOW BOUNDARY THAT PUSHES SOUTH
ACROSS SOUTHERN KENTUCKY OVERNIGHT. THIS WILL BEAR WATCHING AS WE
HEAD INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 736 AM EDT SAT JUL 18 2015
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH TODAY AND MOST OF
TONIGHT. HOWEVER...FOG SHOULD BE A LITTLE MORE ROBUST TONIGHT AS
SKIES HAVE A BETTER CHANCE OF CLEARING. THIS WOULD ALLOW LOCALLY
DENSE VALLEY FOG TO FORM. THE FOG COULD LIFT ONTO THE RIDGES
BEFORE DISSIPATING TOWARDS DAYBREAK SUNDAY. THUS...WILL GO WITH
FOG AT ALL THE TAF SITES FOR LATE TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
642 AM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 642 AM CDT SAT JUL 18 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THE CONSENSUS OF THE 00Z MODEL CYCLE IS THAT THE UPPER-LEVEL RIDGE
WILL HOLD STRONG ACROSS THE REGION THROUGH THE WEEKEND...AND THEN
IT WILL BE SUPPRESSED TO THE SOUTH/SOUTHWEST ON MONDAY. THE HEAT
ADVISORY LOOKS GOOD FOR TODAY AND SUNDAY. AT THIS TIME...DO NOT
SEE ANYTHING THAT WOULD INDICATE A NEED TO UPGRADE TO A WARNING.
THE MAIN CONCERN IS THE POTENTIAL FOR AT LEAST THE SOUTHERN HALF
OF THE AREA TO NEED A CONTINUATION INTO MONDAY. SINCE THE ENTIRE
AREA HAD 100+ HEAT INDICES YESTERDAY/FRIDAY...MONDAY WOULD BE THE
FOURTH CONSECUTIVE DAY OF 100+ HEAT INDICES WHICH WOULD SUPPORT A
CONTINUATION...EVEN IF ONLY 100-105 IS FORECAST. CONFIDENCE IN THE
MONDAY FORECAST IS QUITE LOW DUE TO A WEAK COLD FRONT AND
ASSOCIATED CONVECTION THAT IS EXPECTED TO BE DRAPED ACROSS THE
REGION. WILL LEAVE THE ADVISORY AS IS FOR NOW. AN UPDATED PRODUCT
WILL BE OUT BY 4 AM.
THE HRRR AND THE NMM AND ARW WRF RUNS ALL DEVELOP SOME ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS OVER ROUGHLY THE EASTERN HALF OF
THE FORECAST AREA FROM MIDDAY TODAY THROUGH THIS AFTERNOON. THIS
WOULD BE DIURNAL ACTIVITY IN A VERY WEAK FLOW REGIME...SO A PULSY
STRONG STORM WILL BE POSSIBLE WITH ISOLATED STRONG WINDS...BUT
ORGANIZED SEVERE WEATHER IS NOT EXPECTED.
POPS WILL BE INCREASING FROM THE NORTH THROUGH THE DAY SUNDAY AND
MUCH OF SUNDAY NIGHT...AS A COLD FRONT APPROACHES THE REGION. THE
CONSENSUS OF 00Z GUIDANCE BRINGS THE FRONT INTO THE AREA IN THE
LATE EVENING AND PUSHES IT THROUGH THE ENTIRE AREA BY 15Z MONDAY.
WILL HAVE POPS UP TO LOW-END LIKELY LEVELS WITH THE FRONT ALONG
THE I-64 CORRIDOR SUNDAY NIGHT. SUNDAY IS LIKELY TO BE DRY...BUT
20-30 POPS ARE FORECAST MAINLY IN THE NORTH JUST TO BE SAFE. POPS
MONDAY WILL BE IN THE CHANCE RANGE DUE TO UNCERTAINTIES IN
FRONTAL LOCATION AND DIURNAL HEATING.
THE FLOW INCREASES SIGNIFICANTLY LATE SUNDAY NIGHT INTO
MONDAY...SO STORMS IN THIS PERIOD WILL LIKELY BE MORE ORGANIZED. A
FEW SEVERE STORMS WITH DAMAGING WINDS WILL BE POSSIBLE. OF COURSE
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING WILL ACCOMPANY ANY
THUNDERSTORMS THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THIS EXTENDED FORECAST PACKAGE WOULD BE MORE FRUSTRATING TO DEAL
WITH CONSIDERING THE DAY TO DAY VARIATIONS OF THE DETERMINISTIC
GUIDANCE...PARTICULARLY THE GFS DETERMINISTIC MODEL. WITH THIS
PARTICULAR FORECAST PACKAGE...HAD TO FIGHT AGAINST THE EMPHASIS OF
THE DETERMINISTIC GFS GUIDANCE TO RETROGRADE THE SOUTHERN U.S. RIDGE
LATER IN THE WEEK TO ALLOW FOR FASTER AND SLIGHTLY WETTER FLOW AHEAD
OF THE RIDGE.
LOOKING AT THE WESTERN REGION FORECASTER CONFIDENCE TOOLKIT...THE
ENSEMBLE GUIDANCE...EVEN THE GFS ENSEMBLE CONTINUE TO HINT THAT THE
SOUTHERN U.S. RIDGE WILL REMAIN DOMINANT AND WILL NOT RETROGRADE
LATTER IN THE WEEK. CIPS AND OTHER ANALYSIS/ANALOG/ENSEMBLE PLOTS
CONTINUE TO HINT THAT NEXT WEEKEND /JULY 25-26/ WILL BE THE WARMEST
AND DRIEST SO FAR THIS SUMMER. I WOULD NOT BE SURPRISED IF A SPOT OR
TWO IN SOUTHEAST MISSOURI REACHES 98-100...ESPECIALLY BY NEXT
SATURDAY OR SUNDAY.
WITH THE ADJUSTMENT OF THE GRIDDED FORECAST TOWARD THE WARMER AND
DRIER SOLUTION...ADJUSTED DEWPOINTS DOWNWARD 1-2 DEGREES AND LOWERED
OPAQUE CLOUD COVER INTO THE PARTLY CLOUDY CATEGORY VERSUS MOSTLY
CLOUDY. ALL OF THESE CHANGES WILL SUGGEST AND SUPPORT GREATER
EVAPORATION AND INSOLATION...LEADING TO A LONGER DRY SPELL FOR THE
REGION.
FROM A HEAT STANDPOINT...IT LOOKS LIKE NEXT SATURDAY WILL BRING A
RETURN TO A HEAT ADVISORY (OR HIGHER) TO SOUTHEAST MISSOURI...WITH
HEAT INDEX VALUES NEAR 110 WIDESPREAD ON THAT DAY. SUNDAY DOES NOT
LOOK MUCH BETTER.
THERE REMAINS SOME CHALLENGE AS TO THE IMPACT AND COVERAGE OF
PRECIPITATION TUESDAY THROUGH THURSDAY OF NEXT WEEK.
HOWEVER...DEPENDING ON THE INTERPLAY BETWEEN THE RIDGE AND THE FAST
ZONAL FLOW JUST NORTH OF THE RIDGE...THE WFO PAH FORECAST AREA MAY
STILL SEE SOME CONVECTIVE ACTIVITY THROUGH THURSDAY.
&&
.AVIATION...
ISSUED AT 642 AM CDT SAT JUL 18 2015
A FEW CU AND LIGHT SOUTH WINDS WILL BE THE RULE FOR THIS VFR
FORECAST. AN ISOLATED THUNDERSTORM WILL BE POSSIBLE THIS
AFTERNOON MAINLY NEAR KOWB AND POSSIBLY KEVV. WILL ADD TS TO THE
TAFS IF/WHEN IT BECOMES MORE OBVIOUS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
ILZ075>078-080>094.
MO...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
MOZ076-086-087-100-107>112-114.
IN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
INZ081-082-085>088.
KY...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT SUNDAY FOR
KYZ001>022.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...SMITH
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
736 AM EDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 736 AM EDT SAT JUL 18 2015
LAST OF THE EARLY MORNING SHOWERS HAVE PUSHED OUT OF THE
REGION...WITH DRY WEATHER LIKELY SETTING IN FOR THE REST OF THE
MORNING. HRRR HAS BEEN CONSISTENT ON SHOWING SOME REDEVELOPMENT
ACROSS EASTERN KENTUCKY THROUGH THE MORNING HOURS...BUT HAVE SEEN
NO EVIDENCE OF THIS HAPPENING YET. THUS...WILL MAINTAIN DRY
WEATHER OVER THE NEXT SEVERAL HOURS...BEFORE BRING SOME ISOLATED
SHOWERS/STORMS BACK IN THIS AFTERNOON WITH PEAK HEATING. MAIN AREA
OF FOCUS WILL BE A LEFT OVER OUTFLOW BOUNDARY THAT PUSHES SOUTH
ACROSS SOUTHERN KENTUCKY OVERNIGHT. THIS WILL BEAR WATCHING AS WE
HEAD INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 736 AM EDT SAT JUL 18 2015
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH TODAY AND MOST OF
TONIGHT. HOWEVER...FOG SHOULD BE A LITTLE MORE ROBUST TONIGHT AS
SKIES HAVE A BETTER CHANCE OF CLEARING. THIS WOULD ALLOW LOCALLY
DENSE VALLEY FOG TO FORM. THE FOG COULD LIFT ONTO THE RIDGES
BEFORE DISSIPATING TOWARDS DAYBREAK SUNDAY. THUS...WILL GO WITH
FOG AT ALL THE TAF SITES FOR LATE TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1107 AM EDT SAT JUL 18 2015
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 1105 AM EDT SAT JUL 18 2015
A DECREASING LINE OF SHOWERS AND THUNDERSTORMS IS MOVING TO THE
EAST SOUTHEAST AT ABOUT 35 MPH ACROSS CENTRAL LOWER MICHIGAN. THE
LINE CURRENTLY EXTENDS FROM GRATIOT COUNTY TO EATON COUNTY AND ON
TO KALAMAZOO COUNTY. AN AREA OF LIGHT RAIN IS MOVING THROUGH
BEHIND THE LINE OF STORMS.
&&
.SYNOPSIS...
ISSUED AT 329 AM EDT SAT JUL 18 2015
TODAY WILL BE THE HOTTEST DAY OF THE YEAR WITH HIGH
TEMPERATURES IN THE LOWER MID 90S INLAND OF LAKE MICHIGAN AND IT
WILL EASILY BE VERY HUMID. THE COMBINATION OF THESE WILL RESULT
IN SIGNIFICANT HEAT STRESS FOR THOSE OUTSIDE THIS AFTERNOON IN
SOUTHWEST MICHIGAN. THERE IS A GOOD CHANCE OF THUNDERSTORMS
TONIGHT AHEAD OF A COLD FRONT THAT COMES THROUGH SUNDAY MORNING. A
SECOND COLD FRONT WILL BRING YET COOLER AIR FOR THE MIDDLE OF THIS
COMING WEEK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
THE PRIMARY QUESTION IS WHAT HAPPENS TO THE MCS CROSSING MINNESOTAINTO
WISCONSIN THIS MORNING? DOES IT REACH LOWER MICHIGAN BY MIDDAY OR
DOES IF DISSIPATE? THEN NEXT QUESTION IS WILL THERE BE
THUNDERSTORMS AHEAD OF THE COLD FRONT TONIGHT? FINALLY WILL THE
TEMPERATURE REALLY MAKE IT IN TO THE LOWER TO MID 90S INLAND OF
LAKE MICHIGAN THIS AFTERNOON?
GIVEN THE SHORTWAVE RIDGING OVER LOWER MICHIGAN TODAY... AND
LOOKING AT MODEL SOUNDING IT WOULD SEEM THE AIR SHOULD BE TO DRY
ALOFT FOR THE UPSTREAM CONVECTION TO REACH LOWER MICHIGAN THIS
AFTERNOON. STILL WE WILL HAVE SURFACE BASE CAPES OVER 2500 J/KG
THIS AFTERNOON SO THE STORMS CAN NOT BE RULED OUT TOTALLY. AS A
RESULT I HAVE LOW CHANCE POPS JUST IN CASE.
THE NAM HAS 1000/925 MB THICKNESS VALUES HIGH ENOUGH FOR HIGHS IN
THE MID 90S. THE ONLY QUESTION IS WILL THERE BE TO MUCH CLOUD
COVER. GIVEN THE SHORTWAVE RIDGING I AM THINKING ANY MCS RELATEDCLOUDS
SHOULD QUICKLY MIX OUT BY MIDDAY.
IT WOULD SEE WE DO HAVE A GOOD SHOT AT THUNDERSTORMS TONIGHT GIVEN
THE COLD FRONT IS COMING THROUGH. PROBLEM IS THE UPPER JET LAGS
BEHIND.
IT WOULD BE MOSTLY SUNNY AND COOLER MONDAY BEHIND THE FRONT WITH
HIGH PRESSURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
A COUPLE OF COLD FRONTS WILL MOVE THROUGH LOWER MICHIGAN NEXT WEEK
WHICH WILL KEEP TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL; HIGHS
AROUND 80 ARE EXPECTED.
A WEAK COLD FRONT WILL MOVE SOUTH THROUGH THE CWA MONDAY NIGHT BUT
GIVEN THE TIMING AND NW FLOW ALOFT WE DON/T SEE MUCH PCPN DURING
THAT TIME. THEN HIGH PRESSURE BUILDS INTO THE GREAT LAKES FOR A FEW
DAYS RESULTING IN PARTLY CLOUDY SKIES. MUCH LESS HUMIDITY IS
EXPECTED WITH DEWPOINTS IN THE UPPER 50S TOO. THE ECMWF/GFS SHOW A
SHORT WAVE COMING THROUGH THURSDAY/THURSDAY NIGHT IN CONJUNCTION
WITH SOUTH FLOW DEVELOP AND THIS MAY PRODUCE SOME LIGHT PCPN...BUT
CONFIDENCE IS LOW ON THIS HAPPENING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 741 AM EDT SAT JUL 18 2015
THE LINE THUNDERSTORMS OVER WISCONSIN IS HEADING EAST AROUND 40
MPH AND WOULD REACH THE MKG TAF SITE AROUND 1430Z BASED ON OUR
TIMING TOOL. THEY WOULD REACH THE GRAND RAPIDS AROUND 1530Z. USING
THE EXPERIMENTAL VERSION OF THE HRRR (WHICH HAS BEEN DOING VERY
NICELY WITH THE LOCATION AND TIMING OF THESE STORMS ALL NIGHT)
BRINGS THE STORMS INTO SOUTHWEST MICHIGAN AROUND 12Z-13Z THEN
DISPATES THEM TOTALLY BY 15Z. SEEMS THE STORMS WOULD GET TO THE
MKG TAF SITE BEFORE THEY DISIPATE SO I INCLUDED THEM IN THE MKG
TAF.
ONCE THE LINE IS THROUGH SKIES SHOULD BE MOSTLY SUNNY TODAY AS I
EXPECT THE THICK LAYERED CLOUDS FROM THE MCS TO MIX OUT BY LATE
MORNING. A SECOND LINE IS EXPECTED TO FORM LATE THIS AFTERNOON AND
MOVE ONSHORE AROUND 23Z OR SO. I PUT THESE STORMS IN THE TAF
FORECAST TOO AS THE HRRR HAS BEEN CONSISTANT IN FORECASTING THEST
STORM TOO. AFTER THE STORMS MOVE THROUGH I EXPECT VFR CIGS/VSBY
THROUGH SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 329 AM EDT SAT JUL 18 2015
I KEPT THE MARINE DESNE FOG ADVISORY DUE TO THE HIGH DEW POINTS.
WE MAY NEED TO LOOK AT A SMALL CRAFT ADVIOSY SUNDAY FOR WINDS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ056>059-064>067-
071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
MESOSCALE...63
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...04
AVIATION...WDM
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
854 AM EDT SAT JUL 18 2015
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 853 AM EDT SAT JUL 18 2015
A LINE OF STRONG TO SEVERE THUNDERSTORMS IS CURRENTLY MOVING ON
SHORE JUST NORTH OF MUSKEGON TO NEAR LUDINGTON AT AROUND 45 MPH.
THE LINE IS MOVING INTO MORE STABLE AIR AND I EXPECT THE LINE TO
WEAKEN AS IT MOVES ONSHORE. STILL THE STORMS ARE EXPECTED HAVE
STRONG WIND GUSTS AS THEY MOVE ON SHORE. LOCALLY HEAVY RAIN IS
ALSO EXPECTED.
&&
.SYNOPSIS...
ISSUED AT 329 AM EDT SAT JUL 18 2015
TODAY WILL BE THE HOTTEST DAY OF THE YEAR WITH HIGH
TEMPERATURES IN THE LOWER MID 90S INLAND OF LAKE MICHIGAN AND IT
WILL EASILY BE VERY HUMID. THE COMBINATION OF THESE WILL RESULT
IN SIGNIFICANT HEAT STRESS FOR THOSE OUTSIDE THIS AFTERNOON IN
SOUTHWEST MICHIGAN. THERE IS A GOOD CHANCE OF THUNDERSTORMS
TONIGHT AHEAD OF A COLD FRONT THAT COMES THROUGH SUNDAY MORNING. A
SECOND COLD FRONT WILL BRING YET COOLER AIR FOR THE MIDDLE OF THIS
COMING WEEK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
THE PRIMARY QUESTION IS WHAT HAPPENS TO THE MCS CROSSING MINNESOTAINTO
WISCONSIN THIS MORNING? DOES IT REACH LOWER MICHIGAN BY MIDDAY OR
DOES IF DISSIPATE? THEN NEXT QUESTION IS WILL THERE BE
THUNDERSTORMS AHEAD OF THE COLD FRONT TONIGHT? FINALLY WILL THE
TEMPERATURE REALLY MAKE IT IN TO THE LOWER TO MID 90S INLAND OF
LAKE MICHIGAN THIS AFTERNOON?
GIVEN THE SHORTWAVE RIDGING OVER LOWER MICHIGAN TODAY... AND
LOOKING AT MODEL SOUNDING IT WOULD SEEM THE AIR SHOULD BE TO DRY
ALOFT FOR THE UPSTREAM CONVECTION TO REACH LOWER MICHIGAN THIS
AFTERNOON. STILL WE WILL HAVE SURFACE BASE CAPES OVER 2500 J/KG
THIS AFTERNOON SO THE STORMS CAN NOT BE RULED OUT TOTALLY. AS A
RESULT I HAVE LOW CHANCE POPS JUST IN CASE.
THE NAM HAS 1000/925 MB THICKNESS VALUES HIGH ENOUGH FOR HIGHS IN
THE MID 90S. THE ONLY QUESTION IS WILL THERE BE TO MUCH CLOUD
COVER. GIVEN THE SHORTWAVE RIDGING I AM THINKING ANY MCS RELATEDCLOUDS
SHOULD QUICKLY MIX OUT BY MIDDAY.
IT WOULD SEE WE DO HAVE A GOOD SHOT AT THUNDERSTORMS TONIGHT GIVEN
THE COLD FRONT IS COMING THROUGH. PROBLEM IS THE UPPER JET LAGS
BEHIND.
IT WOULD BE MOSTLY SUNNY AND COOLER MONDAY BEHIND THE FRONT WITH
HIGH PRESSURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
A COUPLE OF COLD FRONTS WILL MOVE THROUGH LOWER MICHIGAN NEXT WEEK
WHICH WILL KEEP TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL; HIGHS
AROUND 80 ARE EXPECTED.
A WEAK COLD FRONT WILL MOVE SOUTH THROUGH THE CWA MONDAY NIGHT BUT
GIVEN THE TIMING AND NW FLOW ALOFT WE DON/T SEE MUCH PCPN DURING
THAT TIME. THEN HIGH PRESSURE BUILDS INTO THE GREAT LAKES FOR A FEW
DAYS RESULTING IN PARTLY CLOUDY SKIES. MUCH LESS HUMIDITY IS
EXPECTED WITH DEWPOINTS IN THE UPPER 50S TOO. THE ECMWF/GFS SHOW A
SHORT WAVE COMING THROUGH THURSDAY/THURSDAY NIGHT IN CONJUNCTION
WITH SOUTH FLOW DEVELOP AND THIS MAY PRODUCE SOME LIGHT PCPN...BUT
CONFIDENCE IS LOW ON THIS HAPPENING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 741 AM EDT SAT JUL 18 2015
THE LINE THUNDERSTORMS OVER WISCONSIN IS HEADING EAST AROUND 40
MPH AND WOULD REACH THE MKG TAF SITE AROUND 1430Z BASED ON OUR
TIMING TOOL. THEY WOULD REACH THE GRAND RAPIDS AROUND 1530Z. USING
THE EXPERIMENTAL VERSION OF THE HRRR (WHICH HAS BEEN DOING VERY
NICELY WITH THE LOCATION AND TIMING OF THESE STORMS ALL NIGHT)
BRINGS THE STORMS INTO SOUTHWEST MICHIGAN AROUND 12Z-13Z THEN
DISPATES THEM TOTALLY BY 15Z. SEEMS THE STORMS WOULD GET TO THE
MKG TAF SITE BEFORE THEY DISIPATE SO I INCLUDED THEM IN THE MKG
TAF.
ONCE THE LINE IS THROUGH SKIES SHOULD BE MOSTLY SUNNY TODAY AS I
EXPECT THE THICK LAYERED CLOUDS FROM THE MCS TO MIX OUT BY LATE
MORNING. A SECOND LINE IS EXPECTED TO FORM LATE THIS AFTERNOON AND
MOVE ONSHORE AROUND 23Z OR SO. I PUT THESE STORMS IN THE TAF
FORECAST TOO AS THE HRRR HAS BEEN CONSISTANT IN FORECASTING THEST
STORM TOO. AFTER THE STORMS MOVE THROUGH I EXPECT VFR CIGS/VSBY
THROUGH SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 329 AM EDT SAT JUL 18 2015
I KEPT THE MARINE DESNE FOG ADVISORY DUE TO THE HIGH DEW POINTS.
WE MAY NEED TO LOOK AT A SMALL CRAFT ADVIOSY SUNDAY FOR WINDS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ056>059-064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
MESOSCALE...WDM
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...04
AVIATION...WDM
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
741 AM EDT SAT JUL 18 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 AM EDT SAT JUL 18 2015
TODAY WILL BE THE HOTTEST DAY OF THE YEAR WITH HIGH
TEMPERATURES IN THE LOWER MID 90S INLAND OF LAKE MICHIGAN AND IT
WILL EASILY BE VERY HUMID. THE COMBINATION OF THESE WILL RESULT
IN SIGNIFICANT HEAT STRESS FOR THOSE OUTSIDE THIS AFTERNOON IN
SOUTHWEST MICHIGAN. THERE IS A GOOD CHANCE OF THUNDERSTORMS
TONIGHT AHEAD OF A COLD FRONT THAT COMES THROUGH SUNDAY MORNING. A
SECOND COLD FRONT WILL BRING YET COOLER AIR FOR THE MIDDLE OF THIS
COMING WEEK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
THE PRIMARY QUESTION IS WHAT HAPPENS TO THE MCS CROSSING MINNESOTAINTO
WISCONSIN THIS MORNING? DOES IT REACH LOWER MICHIGAN BY MIDDAY OR
DOES IF DISSIPATE? THEN NEXT QUESTION IS WILL THERE BE
THUNDERSTORMS AHEAD OF THE COLD FRONT TONIGHT? FINALLY WILL THE
TEMPERATURE REALLY MAKE IT IN TO THE LOWER TO MID 90S INLAND OF
LAKE MICHIGAN THIS AFTERNOON?
GIVEN THE SHORTWAVE RIDGING OVER LOWER MICHIGAN TODAY... AND
LOOKING AT MODEL SOUNDING IT WOULD SEEM THE AIR SHOULD BE TO DRY
ALOFT FOR THE UPSTREAM CONVECTION TO REACH LOWER MICHIGAN THIS
AFTERNOON. STILL WE WILL HAVE SURFACE BASE CAPES OVER 2500 J/KG
THIS AFTERNOON SO THE STORMS CAN NOT BE RULED OUT TOTALLY. AS A
RESULT I HAVE LOW CHANCE POPS JUST IN CASE.
THE NAM HAS 1000/925 MB THICKNESS VALUES HIGH ENOUGH FOR HIGHS IN
THE MID 90S. THE ONLY QUESTION IS WILL THERE BE TO MUCH CLOUD
COVER. GIVEN THE SHORTWAVE RIDGING I AM THINKING ANY MCS RELATEDCLOUDS
SHOULD QUICKLY MIX OUT BY MIDDAY.
IT WOULD SEE WE DO HAVE A GOOD SHOT AT THUNDERSTORMS TONIGHT GIVEN
THE COLD FRONT IS COMING THROUGH. PROBLEM IS THE UPPER JET LAGS
BEHIND.
IT WOULD BE MOSTLY SUNNY AND COOLER MONDAY BEHIND THE FRONT WITH
HIGH PRESSURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 329 AM EDT SAT JUL 18 2015
A COUPLE OF COLD FRONTS WILL MOVE THROUGH LOWER MICHIGAN NEXT WEEK
WHICH WILL KEEP TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL; HIGHS
AROUND 80 ARE EXPECTED.
A WEAK COLD FRONT WILL MOVE SOUTH THROUGH THE CWA MONDAY NIGHT BUT
GIVEN THE TIMING AND NW FLOW ALOFT WE DON/T SEE MUCH PCPN DURING
THAT TIME. THEN HIGH PRESSURE BUILDS INTO THE GREAT LAKES FOR A FEW
DAYS RESULTING IN PARTLY CLOUDY SKIES. MUCH LESS HUMIDITY IS
EXPECTED WITH DEWPOINTS IN THE UPPER 50S TOO. THE ECMWF/GFS SHOW A
SHORT WAVE COMING THROUGH THURSDAY/THURSDAY NIGHT IN CONJUNCTION
WITH SOUTH FLOW DEVELOP AND THIS MAY PRODUCE SOME LIGHT PCPN...BUT
CONFIDENCE IS LOW ON THIS HAPPENING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 741 AM EDT SAT JUL 18 2015
THE LINE THUNDERSTORMS OVER WISCONSIN IS HEADING EAST AROUND 40
MPH AND WOULD REACH THE MKG TAF SITE AROUND 1430Z BASED ON OUR
TIMING TOOL. THEY WOULD REACH THE GRAND RAPIDS AROUND 1530Z. USING
THE EXPERIMENTAL VERSION OF THE HRRR (WHICH HAS BEEN DOING VERY
NICELY WITH THE LOCATION AND TIMING OF THESE STORMS ALL NIGHT)
BRINGS THE STORMS INTO SOUTHWEST MICHIGAN AROUND 12Z-13Z THEN
DISPATES THEM TOTALLY BY 15Z. SEEMS THE STORMS WOULD GET TO THE
MKG TAF SITE BEFORE THEY DISIPATE SO I INCLUDED THEM IN THE MKG
TAF.
ONCE THE LINE IS THROUGH SKIES SHOULD BE MOSTLY SUNNY TODAY AS I
EXPECT THE THICK LAYERED CLOUDS FROM THE MCS TO MIX OUT BY LATE
MORNING. A SECOND LINE IS EXPECTED TO FORM LATE THIS AFTERNOON AND
MOVE ONSHORE AROUND 23Z OR SO. I PUT THESE STORMS IN THE TAF
FORECAST TOO AS THE HRRR HAS BEEN CONSISTANT IN FORECASTING THEST
STORM TOO. AFTER THE STORMS MOVE THROUGH I EXPECT VFR CIGS/VSBY
THROUGH SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 329 AM EDT SAT JUL 18 2015
I KEPT THE MARINE DESNE FOG ADVISORY DUE TO THE HIGH DEW POINTS.
WE MAY NEED TO LOOK AT A SMALL CRAFT ADVIOSY SUNDAY FOR WINDS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT FRI JUL 17 2015
STREAMFLOWS AT MOST OF OUR RIVER GAUGES ARE RUNNING WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THUNDERSTORMS THIS WEEKEND MAY PRODUCE
LOCALLY HEAVY RAINFALL... WHICH WOULD LEAD TO SHORT DURATION URBAN
AND LOW LYING AREA FLOODING. A FEW RIVERS COULD RISE OUT OF THEIR
BANKS IF HEAVY RAIN FALLS WITHIN CERTAIN DRAINAGE BASINS. THE MOST
SUSCEPTIBLE RIVERS TO FLOODING WILL BE THE ONES THAT WERE AFFECTED
BY HEAVY RAIN LAST MONTH... GENERALLY THE UPPER PORTION OF THE GRAND
RIVER BASIN (IONIA-LANSING-JACKSON AREAS) AND THE KALAMAZOO BASIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ056>059-064>067-071>074.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...04
AVIATION...WDM
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
650 AM CDT SAT JUL 18 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 410 AM CDT SAT JUL 18 2015
FIRST FORECAST CHALLENGE FOR TODAY IS POPS. SEEING EXPANDING
COVERAGE IN ISOLATED TO WIDELY SCATTERED CONVECTION OVER WEST
CENTRAL/NORTHWEST MISSOURI AT THIS TIME. HRRR SEEMS TO BE HANDLING
THIS WAA PRECIP THE BEST AT THE MOMENT, BUT LATEST RUNS OF THE RAP
DO SEEM TO BE CATCHING UP. FORECAST SOUNDINGS SHOW THE PROVERBIAL
CAP OF FORGED STEEL DEVELOPING...SO SURFACE BASED CONVECTION LOOKS
PRETTY UNLIKELY. MY GUT FEELING IS THAT THE HRRR IS TOO AGGRESSIVE
IN BOTH AREAL COVERAGE AND LONGEVITY IN KEEPING PRECIP GOING THROUGH
LATE MORNING AND EARLY AFTERNOON...AND THE RAP MAY NOT BE AGGRESSIVE
ENOUGH, SO I WENT SOMEWHERE IN BETWEEN INCREASING POPS TO SLIGHT
CHANCE ACROSS CENTRAL AND NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS.
SECOND CHALLENGE IS TEMPERATURES...AND THE HEAT ADVISORY WHICH IS
ALREADY IN EFFECT. OBVIOUSLY, PRECIPITATION AND CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TODAY. IF THE HRRR IS MORE RIGHT
THAN WRONG TODAY, THEN ITS UNLIKELY THAT TEMPERATURES WILL HIT THE
MID AND UPPER 90S AS PER THE CURRENT FORECAST. STUCK WITH THE
WARMER FORECAST AND USED A BLEND OF GUIDANCE FOR HIGHS...LEANING
TOWARD A MIX-DOWN OF 850MB GFS TEMPERATURES. NO CHANGE TO THE HEAT
HEADLINES IS ANTICIPATED AT THIS TIME WITH THE CAVEAT THAT THIS
MORNING`S PRECIP DOESN`T DEVELOP INTO SOMETHING MORE SUBSTANTIAL.
CARNEY
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT JUL 18 2015
HEAT REMAINS THE PRIMARY FORECAST CONCERN THRU SUNDAY...AND PERHAPS
INTO MONDAY.
UPPER LEVEL RIDGE DOMINATING THE SOUTHERN CONUS WILL CONTINUE TO
COMMAND A STRONG INFLUENCE INTO OUR REGION INTO SUNDAY...BUT IS
EXPECTED TO BEGIN TO BREAKDOWN A BIT FROM THE NORTH AS THE FIRST IN
A SERIES OF UPPER LEVEL DISTURBANCES PASS THRU. AT THE SURFACE...
THIS WILL EQUATE TO OUR REGION REMAINING IN A S-SW FLOW INTO
SUNDAY...WITH A COLD FRONT DROPPING DOWN MAINLY FROM THE AFTERNOON
HOURS ONWARD. WHILE THIS FRONT IS EXPECTED TO SETTLE ACROSS
SOUTHERN MO AND FAR SOUTHERN IL BY SUNDAY NIGHT...THERE IS
INCREASING EVIDENCE IN THE MODELS THAT THIS FIRST FRONT WILL
DISSOLVE SUNDAY NIGHT WITH A SW FLOW RESUMING ALREADY ON MONDAY IN
TIME FOR ANOTHER FRONT TO DROP DOWN DURING THE AFTERNOON.
REFERENCE SHORT-TERM DISCUSSION ON HEAT FORECAST FOR TODAY.
THE DANGEROUS HEAT AND HUMIDITY IS STILL EXPECTED TO CONTINUE INTO
SUNDAY FOR MUCH OF OUR REGION...ENOUGH TO WARRANT MAINTAINING A HEAT
ADVISORY...ALTHOUGH WITH INCREASING UNCERTAINTY ON ITS NORTHERN
PERIPHERY...AS WHAT LOOKS TO BE A NOCTURNAL CONVECTIVE EVENT WILL
TAKE HOLD FOR LATE TONIGHT AND CARRY INTO SUNDAY MORNING FOR AREAS
MAINLY NORTH OF I-70. THIS WILL BRING WITH IT THE ASSOCIATED DEBRIS
CLOUD THAT WILL PROBABLY LINGER INTO SUNDAY AFTERNOON AND FURTHER
COMPLICATE TEMPS AND HEAT INDEX VALUES WITH A DECENT GRADIENT
SOMEWHERE IN THE VICINITY OF I-70... ALL THE WHILE WITH THE SURFACE
COLD FRONT DROPPING INTO THIS AREA AS WELL DURING THE AFTERNOON.
SOME AREAS MAY EVENTUALLY NEED TO BE LOPPED OFF FROM THE HEAT
ADVISORY BUT THE CONFIDENCE FOR DOING IT THIS PACKAGE IS NOT THERE.
TO FURTHER COMPLICATE THINGS...THE POSSIBLE DISSOLUTION OF THE FRONT
SUNDAY NIGHT AND RETURN OF THE HEAT ALREADY BY MONDAY MAY
NECESSITATE AN EXTENSION OF THE HEAT ADVISORY FOR PARTS OF OUR AREA
INTO MONDAY. BUT AGAIN...THE CONFIDENCE FOR DOING IT WITH THIS
PACKAGE IS SIMPLY NOT THERE AT THIS TIME.
FOCUS THEN SHIFTS TO RAIN CHCS AND SEVERE POTENTIAL FOR EARLY NEXT
WEEK.
THE NOCTURNAL CONVECTIVE EVENT FOR AREAS NORTH OF I-70 WILL HAVE
POTENTIAL FOR SEVERE STORMS PERHAPS ALONG THE FAR NORTHERN CWA FOR A
WINDOW OF TIME THIS EVENING. SEVERE STORM POTENTIAL ON SUNDAY WILL
BE HIGHLY DEPENDENT ON EXACTLY WHAT HAPPENS THE NIGHT BEFORE BUT
ENOUGH INSTABILITY SHOULD BE PRESENT FOR AT LEAST AN ISOLATED SEVERE
STORM THREAT. MORE OR LESS THE SAME ON MONDAY WITH A NEW FRONT AND
SIMILAR INSTABILITY IN PLACE.
THE LINGERING FRONTAL BOUNDARY THRU TUESDAY WILL KEEP RAIN CHANCES
GOING. WE MAY SEE A BRIEF REPRIEVE LATE TUESDAY THRU WEDNESDAY WITH
INFLUENCE OF SURFACE HI PRESSURE BUT A WARM FRONT LATE WEDNESDAY
NIGHT INTO THURSDAY WILL ALLOW FOR THE RETURN OF RAIN CHANCES INTO
THE AREA.
ANOTHER ROUND OF HEAT REMAINS ON TAP FOR PERHAPS AS EARLY AS
THURSDAY AFTERNOON...BUT MODEL CONSENSUS AGREES TO DELAY A DAY INTO
FRIDAY AND NEXT WEEKEND.
TES
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 630 AM CDT SAT JUL 18 2015
VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL TODAY ACROSS THE
AREA. SCATTERED SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL
CONTINUE TO MOVE EAST INTO CENTRAL AND NORTHEAST MISSOURI THIS
MORNING. LATEST THINKING IS THAT THE HEAVIEST PRECIP WILL STAY
WELL WEST OF THE AREA TODAY...AND THAT THE MAJORITY OF THE RAIN
SHOULD DISSIPATE THROUGH THE LATE MORNING AND EARLY AFTERNOON.
THERE WILL BE A BETTER CHANCE OF STORMS ACROSS NORTHERN PORTIONS
OF THE AREA THIS EVENING AND OVERNIGHT AHEAD OF AN APPROACHING
COLD FRONT. VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL OUTSIDE
OF THE STORMS.
SPECIFICS FOR KSTL:
EXPECT VFR FLIGHT CONDITIONS TO PREVAIL TODAY AND INTO TONIGHT AT
LAMBERT. SHOWERS OVER WESTERN/CENTRAL MISSOURI SHOULD DISSIPATE
BEFORE REACHING THE TERMINAL; BUT I CAN`T TOTALLY RULE OUT A STRAY
SHOWER OR THUNDERSTORM. WIND WILL SHIFT FROM A WEST-SOUTHWEST TO A
SOUTHERLY DIRECTION TODAY, UNFORTUNATELY THIS MEANS THE WIND WILL
PROBABLY BE VERY NEARLY A DIRECT CTOSSWIND FOR THE MAIN RUNWAYS
DURING SOME PERIOD THIS AFTERNOON. THINK LAMBERT WILL BE FAR
ENOUGH SOUTH TO AVOID ANY STORMS TONIGHT, BUT THE CHANCES FOR
STORMS WILL INCREASE AFTER 12Z SUNDAY MORNING.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR CRAWFORD MO-
IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-
LINCOLN MO-MONITEAU MO-MONTGOMERY MO-OSAGE MO-ST. CHARLES
MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KNOX MO-LEWIS MO-
MARION MO-MONROE MO-PIKE MO-RALLS MO-SHELBY MO.
IL...HEAT ADVISORY FROM NOON TODAY TO 8 PM CDT SUNDAY FOR BOND IL-
CLINTON IL-FAYETTE IL-MARION IL-MONTGOMERY IL-RANDOLPH IL-
WASHINGTON IL.
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR CALHOUN IL-GREENE IL-
JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-ST. CLAIR IL.
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ADAMS IL-BROWN IL-
PIKE IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1101 AM EDT SAT JUL 18 2015
.SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON,
WITH THE HIGHEST CHANCES ACROSS NORTHEAST PENNSYLVANIA AND THE
CATSKILLS. AFTER THE THUNDERSTORMS DIE DOWN THIS EVENING A VERY
HUMID AND WARM AIR MASS WILL BE IN PLACE. HIGHS SUNDAY WILL TOP 90
DEGREES IN MANY AREAS WITH HEAT INDICES APPROACHING 100 DEGREES
DUE TO THE HIGH HUMIDITY. THE INCREASE IN HEAT AND HUMIDITY ALONG
WITH A COLD FRONT MAY PRODUCE STRONG STORMS SUNDAY AFTERNOON AND
NIGHT. MORE COMFORTABLE AIR RETURNS TO THE AREA BY EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST KBGM RADAR SHOWS JUST A FEW ISOLATED SHRA IN PARTS OF THE
WESTERN CATSKILLS AND EXTREME NE PA AT THIS TIME WITH A FEW
SHRA/TSRA IN THE ALLEGHENIES OF WRN NY AND NC PA. LARGE SCALE
MOSAIC RADAR IMAGERY SHOWS AN MCS MOVING ACRS LAKE MICHIGAN AND
LWR MICHIGAN. THE HRRR...WRF_ARW...WRF_NMM...RAP AND NAM ALL SHOW
THAT THIS MCS WILL DIVE SE AND FALL APART AS DIURNAL HEATING
KICKS IN AND DISRUPTS THE INFLOW INTO THIS FEATURE. MODELS ALSO
SHOW ANOTHER SHORT WAVE PASSING ACRS NY AND PA THIS AFTERNOON
WHICH COULD BE CONVECTIVELY INDUCED BY THIS MCS. IN ADDTN...MODEL
MIXED LAYER CAPES THIS AFTERNOON VARY FROM 3000 TO 4000 J/KG ON
THE LATEST NAM...TO 2000-3000 J/KG ON THE WRF_NMM....TO 1000 TO
2000 J/KG ON THE HRRR AND WRF_ARW. THE GFS HAS AROUND 1000 J/KG.
VISIBLE SATELLITE IMAGERY ALSO SHOWS BREAKS AND DESTABILIZATION
BEGINNING TO TAKE PLACE. THE WATER VAPOR AND 7.4 MICRON IMAGERY
SHOWS A LOT OF DRY AIR ADVECTING OVER NY AND PA AS WELL LATE THIS
MORNING WITH STRG MID-LVL SUBSDC AT PRESENT. AS THIS SMALL SHORT
WAVE WORKS E THIS AFTERNOON THERE WILL BE SOME ASCENT AND ALL HI
RES CONVECTION ALLOWING MODELS POP MOST OF THE CONVECTION AS PER
MODEL RADAR IMAGERY FROM SC NY TO NE PA. SO HAVE HIGHEST POPS THIS
AFTERNOON INTO EARLY EVENING IN NE PA/SERN NY AND LEAST (SLGHT CHC
TO LO CHC) ON THE LAKE ONTARIO PLAIN.
THE 0-1, 0-3 AND 0-6 KM BULK SHEARS ARE NOT THAT IMPRESSIVE THIS
AFTERNOON RUNNING 15 KNOTS, 20 KNOTS AND 20 KNOTS RESPECTIVELY.
BUT GIVEN CAPES THERE CUD BE A FEW ISOLATED SVR STORMS WITH LARGE
HAIL AND MICROBURST WINDS GIVEN THE DRIER AIR ALOFT. SO WILL CONT
TO MENTION IN HWO FOR THIS AFTERNOON AND EVENING AND FOCUS ON NE
PA TO THE WRN CATSKILLS AND CONCUR WITH SPC MARGINAL RISK.
AFTER CONVECTION DIES DOWN THIS EVENING...WE HAVE SKIES CLEARING
WITH PATCHY FOG DEVELOPING LATE. HOWEVER LATEST RAP SUGGESTS MORE
CONVECTION LATE TONIGHT. OTHER 12Z MODELS SO FAR DO NOT. FOR NOW
WILL KEEP LATE TONIGHT DRY. BUT WILL HAVE TO REASSESS AS MORE
GUIDC COMES IN.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
430 AM UPDATE...
HOT AND HUMID, JUST LIKE SUMMER SHOULD BE. THAT SUMS UP SUNDAY.
DID LITTLE WITH TEMPS, WITH MOST OF THE LOWER ELEVATIONS IN THE
90-92 RANGE, AND ELEVATIONS 84 TO 88. WITH DEWPOINTS NEAR 70, HEAT
INDICES WILL BE IN THE MID TO UPPER 90S, WITH NEAR 100 POSSIBLE IN
THE METRO AREAS OF CNY AND NEPA. EXCELLENT HWO FROM YESTERDAY WAS
KEPT IN TACT FOR THE HEAT THREAT. IN ADDITION FROM JUST 24 HOURS
AGO, THREAT FOR STORMS LATER SUNDAY LOOKS A BIT HIGHER. BEST SHEAR
STILL LOOKS TO BE LATER SUNDAY NIGHT BUT WE SHOULD HAVE MORE OF A
TRIGGER SUNDAY AFTERNOON AND CAPES AGAIN AVERAGE 1000 TO 2000
J/KG.
BOTH THE EURO AND GFS CLEAR US OUT PRETTY QUICKLY MONDAY SO
BESIDES AN EARLY SHOWER, I CLEARED POPS FROM MONDAY AFTERNOON AS
COMFORTABLE AIR SETTLES IN.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE. MINOR CHANGES. IN GENERAL DRY AND AT OR
SLIGHTLY WARMER THAN NORMAL.
NO BIG SYSTEMS WITH WEAK HIGH PRESSURE TUESDAY AND THURSDAY. 20
POPS FOR WEDNESDAY WITH A WEAK FRONT. ANOTHER FRONT DROPS SOUTH
IN THE NW FLOW ALOFT ON FRIDAY WITH CHANCE POPS. MODELS DIFFER ON
THE DETAILS OF THE 2 RAIN MAKERS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHRT WV AND SFC TROF IS TRIGGERING SOME SHWRS AND ISLTD TRWS THIS
MRNG RESULTING IN BRIEF MVFR CIGS AND VSBYS. WV WILL PASS IN THE
NEXT CPL HRS LVG VFR CONDS. SECOND WV WILL TRIGGER SOME SHWRS ARND
MIDDAY WITH PSBL BRIEF LWRG INTO MVFR AS WELL. BALANCE OF THE DAY
WILL CONT VFR CONDS. OVRNGT...LWRD CIGS AND VSBY PSBL IN THE
STABLE CONDS...WITH LIFR PSBL IN ELM IN DENSE FOG.
.OUTLOOK...
SAT THRU MON...A FEW RESTRICTIONS FROM SCT SHRA-
TSRA...ESPECIALLY WITH FRONTAL PASSAGE LATE SUN NGT-EARLY MON.
TUE/WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/HEDEN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...TAC
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
745 AM EDT SAT JUL 18 2015
.SYNOPSIS...
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
WEEKEND. SOME STORMS MAY BE STRONG WITH GUSTY WINDS AND HEAVY
RAINFALL. BEST CHANCE FOR HEAVY RAIN WILL BE SUNDAY NIGHT AHEAD OF
A COLD FRONT WHICH WILL CROSS THE AREA VERY EARLY MONDAY MORNING.
WARMER THAN NORMAL TEMPERATURES THIS WEEKEND WILL TREND BACK
TOWARDS SEASONAL NORMALS DURING THE WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 723 AM EDT SATURDAY...SHOWERS AND THUNDERSTORMS ARE
CURRENTLY MOVING ACROSS NORTHERN VERMONT AND OUT OF OUR AREA. 7 AM
TEMPERATURES WERE GENERALLY IN THE 60S TO AROUND 70 WITH A LOT OF
OVERCAST CLOUD COVER IN PLACE. WITHOUT A LOT OF CLEARING...WILL BE
TOUGH TO GET ENOUGH INSTABILITY FOR SEVERE STORMS. AT THIS POINT
THINK THERE WILL STILL BE SOME AFTERNOON SHOWERS ACROSS
VERMONT...BUT NOT ANTICIPATING ANY SEVERE STORMS. VERY HEAVY RAIN
REMAINS A THREAT WITH PWATS VERY HIGH. ONLY HRRR HAS A DECENT
HANDLE ON CONVECTION ACROSS WESTERN NEW YORK AT THIS TIME. IT
TRACKS THIS ACTIVITY SOUTH OF OUR FORECAST AREA...BUT DOES DEVELOP
SOME SCATTERED SHOWERS ACROSS OUR AREA ANYHOW...DOES NOT LOOK
PARTICULARLY CONVECTIVE...BUT DO EXPECT LIGHTNING AS WE HAVE
ALREADY HAD SOME CONVECTION IN THE EARLY MORNING HOURS TODAY.
STILL FEEL BEST CHANCE FOR CONVECTION WILL BE ACROSS NORTHEASTERN
VERMONT...CLOSEST TO PASSAGE OF SHORTWAVE THIS AFTERNOON AND
EVENING. PREVIOUS DISCUSSION FOLLOWS.
OUR REGION WILL REMAIN IN THE WARM SECTOR TODAY WITH WARM FRONT
NORTH OF OUR AREA AND COLD FRONT STILL OFF TO OUR NORTHWEST.
SHOWERS MOVING ACROSS THE AREA EARLY THIS MORNING WILL PUSH
EASTWARD OUT OF OUR AREA. THERE WILL BE A BREAK IN
PRECIPITATION...AND PROBABLY SOME BREAKS IN THE CLOUDS AS WELL.
ANY SUNSHINE SHOULD HELP TO FURTHER DESTABILIZE THE ENVIRONMENT.
MODELS CONTINUE TO INDICATE MODEST CAPE IN THE AREA. THIS
AFTERNOON WILL SEE PWATS OVER 1.5 INCHES. A STRONG SHORTWAVE
PASSES JUST NORTHEAST OF OUR AREA. FEEL THAT FORCING WITH THIS
FEATURE AND UNSTABLE ENVIRONMENT ALREADY IN PLACE ALONG WITH
SURFACE HEATING WILL FIRE UP SOME STORMS...MAINLY ACROSS OUR
NORTHERN VERMONT ZONES. ANY THUNDERSTORM WILL PRESENT THE
POSSIBILITY OF SOME VERY HEAVY RAIN. THERE`S ALSO SOME DECENT 0-6
KM SHEAR AND HAVE CONTINUED WITH MENTION OF GUSTY WINDS AS
WELL...MAINLY FROM 15Z THRU 02Z.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH MONDAY/...
AS OF 441 AM EDT SATURDAY...TONIGHT WILL BRING A SHORT BREAK IN
THE THUNDERSTORM ACTION BEFORE ANOTHER ROUND ON SUNDAY.
TEMPERATURES WILL BE PRETTY MILD OVERNIGHT WITH AMPLE CLOUD COVER
IN PLACE STILL. ANY SHOWERS REMAINING WILL DISSIPATE WITH LOSS OF
DAYTIME HEATING AND SHORTWAVE ENERGY MOVING PAST OUR AREA. CAN
POTENTIALLY SEE SOME CLEARING BY SUNDAY MORNING WHICH WILL ADD TO
INSTABILITY FOR SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON. PWATS
STILL VERY HIGH...EVEN NEARING 2 INCHES ON SUNDAY AFTERNOON. NOT
MUCH OF A SURFACE FEATURE THOUGH...COLD FRONT WILL STILL BE WELL
WEST OF OUR FORECAST AREA. TEMPERATURES WILL BE WARMER ON
SUNDAY...EDGING INTO THE MID 80S ACROSS MUCH OF THE AREA. MODELS
ONCE AGAIN BRING SOME DECENT CAPE INTO OUR AREA. THERE WILL BE
LESS SHEAR SUNDAY THAN THERE WAS TODAY THOUGH. SHOWERS WILL
CONTINUE INTO THE OVERNIGHT AS COLD FRONT APPROACHES AND CROSSES
THE AREA EARLY MONDAY MORNING. SUNDAY NIGHT MAY ACTUALLY BE THE
BEST CHANCE FOR ANY WIDESPREAD PRECIPITATION IN THE SHORT TERM.
HAVE MENTIONED LIKELY POPS. HEAVY RAIN CONTINUES TO BE A
POSSIBILITY. MODELS ARE NOW SHOWING A QUICKER EXIT FOR THE SHOWERS
MONDAY MORNING AND MONDAY LOOKS TO BE MOSTLY DRY...HAVE LOWERED
POPS. TEMPERATURES WILL BE NEAR SEASONAL NORMALS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. CHANCE OF
SHOWERS INCREASES DURING TUESDAY AS SHORTWAVE TROUGH TROUGH AND
ASSOCIATED SURFACE COLD FRONT ADVANCE RAPIDLY EAST FROM THE GREAT
LAKES. SOME WEAK INSTABILITY INDICATED...SO HAVE INCLUDED SLIGHT
CHANCE THUNDER. CLOUDS WILL PREVENT TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. SHOWERS TAPER
OFF TUESDAY NIGHT WITH PASSAGE OF FRONT AND TROUGH. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW MORE AFTERNOON SHOWERS. SURFACE HIGH PRESSURE BUILDS IN
FOR LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...SCATTERED SHOWERS WILL TAPER OFF FROM WEST
TO EAST THROUGH 14Z. VISIBILITIES LOWERING TO MVFR AT TIMES IN
PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS MAINLY MVFR WITH
SOME IFR AT SLK/MPV THIS MORNING. CEILINGS IMPROVE TO MVFR ALL
SITES BY 16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN
VALLEY EAST. SOUTHERLY WINDS 5-10 KNOTS TODAY EXCEPT GUSTING
AROUND 20 KNOTS IN CHAMPLAIN VALLEY. WINDS BECOME LIGHT AND
VARIABLE TONIGHT. EXPECT SOME MVFR CONDITIONS TO DEVELOP AFTER
04Z WITH POSSIBLE IFR IN FOG AT MPV/SLK.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...
12Z SUN - 18Z SUN...MAINLY VFR.
18Z SUN - 12Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND THUNDERSTORMS.
12Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z THU...MAINLY VFR. CHANCE AFTERNOON
SHOWERS/THUNDERSTORMS BOTH DAYS WITH BRIEF MVFR POSSIBLE.
&&
.MARINE...
AS OF 730 AM EDT SATURDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN THROUGH AROUND NOON. WIND WAVES ARE EXPECTED TO REACH
2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
MARINE...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
733 AM EDT SAT JUL 18 2015
.SYNOPSIS...
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
WEEKEND. SOME STORMS MAY BE STRONG WITH GUSTY WINDS AND HEAVY
RAINFALL. BEST CHANCE FOR HEAVY RAIN WILL BE SUNDAY NIGHT AHEAD OF
A COLD FRONT WHICH WILL CROSS THE AREA VERY EARLY MONDAY MORNING.
WARMER THAN NORMAL TEMPERATURES THIS WEEKEND WILL TREND BACK
TOWARDS SEASONAL NORMALS DURING THE WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 723 AM EDT SATURDAY...SHOWERS AND THUNDERSTORMS ARE
CURRENTLY MOVING ACROSS NORTHERN VERMONT AND OUT OF OUR AREA. 7 AM
TEMPERATURES WERE GENERALLY IN THE 60S TO AROUND 70 WITH A LOT OF
OVERCAST CLOUD COVER IN PLACE. WITHOUT A LOT OF CLEARING...WILL BE
TOUGH TO GET ENOUGH INSTABILITY FOR SEVERE STORMS. AT THIS POINT
THINK THERE WILL STILL BE SOME AFTERNOON SHOWERS ACROSS
VERMONT...BUT NOT ANTICIPATING ANY SEVERE STORMS. VERY HEAVY RAIN
REMAINS A THREAT WITH PWATS VERY HIGH. ONLY HRRR HAS A DECENT
HANDLE ON CONVECTION ACROSS WESTERN NEW YORK AT THIS TIME. IT
TRACKS THIS ACTIVITY SOUTH OF OUR FORECAST AREA...BUT DOES DEVELOP
SOME SCATTERED SHOWERS ACROSS OUR AREA ANYHOW...DOES NOT LOOK
PARTICULARLY CONVECTIVE...BUT DO EXPECT LIGHTNING AS WE HAVE
ALREADY HAD SOME CONVECTION IN THE EARLY MORNING HOURS TODAY.
STILL FEEL BEST CHANCE FOR CONVECTION WILL BE ACROSS NORTHEASTERN
VERMONT...CLOSEST TO PASSAGE OF SHORTWAVE THIS AFTERNOON AND
EVENING. PREVIOUS DISCUSSION FOLLOWS.
OUR REGION WILL REMAIN IN THE WARM SECTOR TODAY WITH WARM FRONT
NORTH OF OUR AREA AND COLD FRONT STILL OFF TO OUR NORTHWEST.
SHOWERS MOVING ACROSS THE AREA EARLY THIS MORNING WILL PUSH
EASTWARD OUT OF OUR AREA. THERE WILL BE A BREAK IN
PRECIPITATION...AND PROBABLY SOME BREAKS IN THE CLOUDS AS WELL.
ANY SUNSHINE SHOULD HELP TO FURTHER DESTABILIZE THE ENVIRONMENT.
MODELS CONTINUE TO INDICATE MODEST CAPE IN THE AREA. THIS
AFTERNOON WILL SEE PWATS OVER 1.5 INCHES. A STRONG SHORTWAVE
PASSES JUST NORTHEAST OF OUR AREA. FEEL THAT FORCING WITH THIS
FEATURE AND UNSTABLE ENVIRONMENT ALREADY IN PLACE ALONG WITH
SURFACE HEATING WILL FIRE UP SOME STORMS...MAINLY ACROSS OUR
NORTHERN VERMONT ZONES. ANY THUNDERSTORM WILL PRESENT THE
POSSIBILITY OF SOME VERY HEAVY RAIN. THERE`S ALSO SOME DECENT 0-6
KM SHEAR AND HAVE CONTINUED WITH MENTION OF GUSTY WINDS AS
WELL...MAINLY FROM 15Z THRU 02Z.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH MONDAY/...
AS OF 441 AM EDT SATURDAY...TONIGHT WILL BRING A SHORT BREAK IN
THE THUNDERSTORM ACTION BEFORE ANOTHER ROUND ON SUNDAY.
TEMPERATURES WILL BE PRETTY MILD OVERNIGHT WITH AMPLE CLOUD COVER
IN PLACE STILL. ANY SHOWERS REMAINING WILL DISSIPATE WITH LOSS OF
DAYTIME HEATING AND SHORTWAVE ENERGY MOVING PAST OUR AREA. CAN
POTENTIALLY SEE SOME CLEARING BY SUNDAY MORNING WHICH WILL ADD TO
INSTABILITY FOR SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON. PWATS
STILL VERY HIGH...EVEN NEARING 2 INCHES ON SUNDAY AFTERNOON. NOT
MUCH OF A SURFACE FEATURE THOUGH...COLD FRONT WILL STILL BE WELL
WEST OF OUR FORECAST AREA. TEMPERATURES WILL BE WARMER ON
SUNDAY...EDGING INTO THE MID 80S ACROSS MUCH OF THE AREA. MODELS
ONCE AGAIN BRING SOME DECENT CAPE INTO OUR AREA. THERE WILL BE
LESS SHEAR SUNDAY THAN THERE WAS TODAY THOUGH. SHOWERS WILL
CONTINUE INTO THE OVERNIGHT AS COLD FRONT APPROACHES AND CROSSES
THE AREA EARLY MONDAY MORNING. SUNDAY NIGHT MAY ACTUALLY BE THE
BEST CHANCE FOR ANY WIDESPREAD PRECIPITATION IN THE SHORT TERM.
HAVE MENTIONED LIKELY POPS. HEAVY RAIN CONTINUES TO BE A
POSSIBILITY. MODELS ARE NOW SHOWING A QUICKER EXIT FOR THE SHOWERS
MONDAY MORNING AND MONDAY LOOKS TO BE MOSTLY DRY...HAVE LOWERED
POPS. TEMPERATURES WILL BE NEAR SEASONAL NORMALS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. CHANCE OF
SHOWERS INCREASES DURING TUESDAY AS SHORTWAVE TROUGH TROUGH AND
ASSOCIATED SURFACE COLD FRONT ADVANCE RAPIDLY EAST FROM THE GREAT
LAKES. SOME WEAK INSTABILITY INDICATED...SO HAVE INCLUDED SLIGHT
CHANCE THUNDER. CLOUDS WILL PREVENT TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. SHOWERS TAPER
OFF TUESDAY NIGHT WITH PASSAGE OF FRONT AND TROUGH. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW MORE AFTERNOON SHOWERS. SURFACE HIGH PRESSURE BUILDS IN
FOR LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...WIDESPREAD SHOWERS ACROSS THE REGION WILL
TAPER OFF FROM WEST TO EAST 08Z-12Z. VISIBILITIES LOWERING TO MVFR
AT TIMES IN PRECIPITATION AND SOME LIGHT FOG/MIST. CEILINGS
LOWERING THROUGH THE NIGHT TO MVFR ALL SITES WITH IFR POSSIBLE
SLK/MPV AND POSSIBLY MSS. CEILINGS IMPROVE TO MVFR ALL SITES 12Z-
16Z AND TO MAINLY VFR BY 18Z. SCATTERED SHOWERS AND THUNDERSTORMS
POSSIBLE THIS AFTERNOON...MAINLY FROM CHAMPLAIN VALLEY EAST.
SOUTHERLY WINDS 5-10 KNOTS THRU 12Z AND UP TO 15-20 KNOTS IN
CHAMPLAIN VALLEY AFT 12Z SAT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 18Z SUN...MAINLY VFR. EARLY MORNING IFR FOG PSBL
KMPV/KSLK. 18Z SUN - 18Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS. 18Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR
FOG PSBL KMPV/KSLK. 12Z TUE - 00Z THU...MAINLY VFR. CHANCE
AFTERNOON SHOWERS/THUNDERSTORMS BOTH DAYS WITH BRIEF MVFR
POSSIBLE..
&&
.MARINE...
AS OF 730 AM EDT SATURDAY...A LAKE WIND ADVISORY IS CURRENTLY IN
EFFECT. STRONG SOUTHERLY WINDS 25-30 KNOTS ARE EXPECTED OVER LAKE
CHAMPLAIN THROUGH AROUND NOON. WIND WAVES ARE EXPECTED TO REACH
2-4 FEET DURING THIS EVENT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
MARINE...NEILES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1023 AM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1015 AM SATURDAY...
EARLIER COMPLEX OF SHOWERS MOVING INTO THE TRIAD HAS ALL BUT
DIMINISHED THIS HOUR WITH A BAD OF CLOUDS REMAINING FROM THE
FOOTHILLS...JUST NOW MOVING INTO THE NW PIEDMONT. NOT A LOT OF
ENHANCEMENT ON THE VISIBLE PICTURE AT THIS TIME AND THE HRRR HAS
BACKED OFF ON ALL PRECIPITATION UNTIL AROUND 17Z WHEN TEMPERATURES
RISE ENOUGH TO START GETTING CONVECTIVE INITIATION ACROSS THE AREA.
CONVECTION SHOULD BEGIN AS SCATTERED SHOWERS ACROSS MUCH OF THE CWA
BUT THEN A PUSH FROM A SHORTWAVE ENTERING THE TRIAD AFTER 18Z COULD
BEGIN TO ORGANIZE STORMS A LITTLE MORE. WITH BULK SHEAR VALUES IN
THE 20-25 KT RANGE AND INSTABILITY BETWEEN 1000-1500 J/KG WOULD
EXPECT SOME KIND OF LINEAR MULTICELLULAR FEATURE WHICH WILL WORK
THROUGH THE CWA FROM NW TO SE THIS AFTERNOON AND INTO THE EARLY
EVENING HOURS. EXPECT THE BEST UPPER LEVEL SUPPORT FROM 500 MB
VORTICITY TO MOVE THROUGH THE TRIANGLE AREA MID AFTERNOON AND THE I-
95 CORRIDOR BY EARLY EVENING. SPC CURRENTLY HAS THE AREA UNDER A
MARGINAL RISK FOR ANY SEVERE STORMS WITH DAMAGING WINDS THE PRIMARY
THREAT. ANY SEVERE ACTIVITY THIS AFTERNOON SHOULD REMAIN ISOLATED.
PREVIOUS DISCUSSION FOLLOWS. -ELLIS
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA. -BSD
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
24-HR TAF PERIOD: VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL
THIS MORNING AND INTO EARLY THIS AFTERNOON AT MOST LOCATIONS.
HOWEVER... WE COULD SEE SOME ISOLATED SHOWERS THIS MORNING ACROSS
THE PIEDMONT (MAINLY KGSO/KINT/KRDU). ISOLATED TO SCATTERED SHOWERS
AND STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING WITH
THE APPROACH OF A MID LEVEL DISTURBANCE FROM THE NORTHWEST. IT NOW
APPEARS THE DISTURBANCE SHOULD MOVE ACROSS THE AREA IN A NORTHWEST
TO SOUTHEAST FASHION... WITH SHOWERS AND STORMS POSSIBLE IN THE
TRIAD BY EARLY AFTERNOON... TO MID TO LATE AFTERNOON ACROSS THE
SOUTHEASTERN PORTION OF THE AREA (KFAY). ANY STORMS WILL HAVE THE
POTENTIAL TO PRODUCE GUSTY WINDS AND SUB-VFR CONDITIONS. EXPECT ANY
SHOWERS AND STORMS SHOULD GENERALLY END BY MID EVENING... WITH ONLY
A SLIGHT CHANCE OF A FEW SHOWERS OVERNIGHT... ALONG WITH A SMALL
CHANCE OF PATCHY FOG.
LOOKING AHEAD: WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH
EARLY/MID NEXT WEEK...A RELATIVELY ENERGETIC SUMMER-TIME PATTERN IN
WHICH DIURNAL CONVECTION WILL POSE THE GREATEST CONCERN TO AVIATION.
NON-DIURNAL (I.E. OVERNIGHT) CONVECTION CANNOT BE RULED OUT IN THE
PRESENCE OF NW FLOW ALOFT...I.E. IF UPSTREAM MESOSCALE CONVECTIVE
SYSTEMS (MCS`S) PROPAGATE INTO THE REGION. MORNING STRATUS AND/OR
FOG WILL ALSO BE POSSIBLE EACH DAY GIVEN SEASONABLE MOISTURE...
PERIODS OF WEAK WARM ADVECTION... AND THE PRESENCE OF CONVECTION
DURING THE LATE EVENING HOURS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...ELLIS/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
700 AM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 305 AM SATURDAY...
TODAY: COMPLEX OF SHOWERS AND STORMS IS STILL GOING THIS MORNING
OVER PORTIONS OF EASTERN KY. HOWEVER... THE COMPLEX OF SHOWERS AND
STORMS IS SHOWING A DOWNWARD TREND IN INTENSITY AS IT SHIFTS EAST
AND SOUTHWARD. THE LATEST HRRR SHOWS THIS DISTURBANCE CONTINUING TO
WEAKEN THIS MORNING AS IT APPROACHES THE AREA. HOWEVER... AS THE
REMNANTS OF THE MCS MOVE ACROSS THE AREA LATE THIS MORNING AND INTO
THE AFTERNOON EXPECT WE SHOULD SEE REDEVELOPMENT ALONG AND AHEAD OF
THIS FEATURE... AND ALONG THE DEVELOPING LEE SIDE SURFACE TROUGH
ACROSS THE AREA FROM SW TO NE. WHILE THE LATEST HRRR SHOWS POSSIBLY
SOME ISOLATED CONVECTION DEVELOPING BY AS EARLY AS 12Z ACROSS THE
PIEDMONT... THINK THE BULK OF THE CONVECTION SHOULD OCCUR FROM THE
AFTERNOON INTO THE EVENING... DEVELOPING FIRST ACROSS THE PIEDMONT
(PROBABLY WESTERN PIEDMONT) THEN EXPANDING EAST AND SOUTHWARD.
THUS... WILL GO WITH SOLID CHANCE POPS FOR TODAY... EXPECTING
SCATTERED SHOWERS AND STORMS. WITH REGARD TO THE POTENTIAL FOR SVR
STORMS. MLCAPE VALUES ARE EXPECTED TO RANGE FROM GENERALLY 1000-2000
J/KG ACROSS THE AREA BY AFTERNOON AS THE AIRMASS CONTINUES TO
MOISTEN AND WARM IN THE WAKE OF THE DEPARTING SURFACE HIGH.
HOWEVER... DEEP LAYER SHEAR VALUES SHOULD GENERALLY BE LESS THAN 20-
25 KTS. THUS... WHILE WE COULD SEE SOME MULTICELLULAR ACTIVITY...
DONT EXPECT A LARGE LINE OF STORMS TO CROSS THE AREA. THE LATEST SPC
DAY 1 CONVECTIVE OUTLOOK HAS CENTRAL NC IN THE MARGINAL CATEGORY (A
FEW STRONG TO SEVERE STORMS POSSIBLE)... WHICH SEEMS REASONABLE
GIVEN THE ABOVE MENTIONED SETUP... WITH THE MAIN THREAT FROM
DAMAGING WIND GUSTS.
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
24-HR TAF PERIOD: VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL
THIS MORNING AND INTO EARLY THIS AFTERNOON AT MOST LOCATIONS.
HOWEVER... WE COULD SEE SOME ISOLATED SHOWERS THIS MORNING ACROSS
THE PIEDMONT (MAINLY KGSO/KINT/KRDU). ISOLATED TO SCATTERED SHOWERS
AND STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING WITH
THE APPROACH OF A MID LEVEL DISTURBANCE FROM THE NORTHWEST. IT NOW
APPEARS THE DISTURBANCE SHOULD MOVE ACROSS THE AREA IN A NORTHWEST
TO SOUTHEAST FASHION... WITH SHOWERS AND STORMS POSSIBLE IN THE
TRIAD BY EARLY AFTERNOON... TO MID TO LATE AFTERNOON ACROSS THE
SOUTHEASTERN PORTION OF THE AREA (KFAY). ANY STORMS WILL HAVE THE
POTENTIAL TO PRODUCE GUSTY WINDS AND SUB-VFR CONDITIONS. EXPECT ANY
SHOWERS AND STORMS SHOULD GENERALLY END BY MID EVENING... WITH ONLY
A SLIGHT CHANCE OF A FEW SHOWERS OVERNIGHT... ALONG WITH A SMALL
CHANCE OF PATCHY FOG.
LOOKING AHEAD: WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH
EARLY/MID NEXT WEEK...A RELATIVELY ENERGETIC SUMMER-TIME PATTERN IN
WHICH DIURNAL CONVECTION WILL POSE THE GREATEST CONCERN TO AVIATION.
NON-DIURNAL (I.E. OVERNIGHT) CONVECTION CANNOT BE RULED OUT IN THE
PRESENCE OF NW FLOW ALOFT...I.E. IF UPSTREAM MESOSCALE CONVECTIVE
SYSTEMS (MCS`S) PROPAGATE INTO THE REGION. MORNING STRATUS AND/OR
FOG WILL ALSO BE POSSIBLE EACH DAY GIVEN SEASONABLE MOISTURE...
PERIODS OF WEAK WARM ADVECTION... AND THE PRESENCE OF CONVECTION
DURING THE LATE EVENING HOURS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
932 AM EDT SAT JUL 18 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY AND TONIGHT.
A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE LOCAL AREA SUNDAY
EVENING AND NIGHT. A STRONGER AREA OF HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT FOR THE START OF THE NEW WORKWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REMNANTS OF THE OVERNIGHT MCS SYSTEM ARE MOVING SOUTHEAST ACROSS
LAKE MICHIGAN. THE SYSTEM IS WEAKENING BUT LAYING OUTFLOW
BOUNDARIES OVER LOWER MICHIGAN. SPC DISCUSSION INDICATES NEW
THUNDERSTORM DEVELOPMENT MAY OCCUR ON THESE BOUNDARIES LATER THIS
AFTERNOON. THE HRRR MODEL SUPPORTS THIS AND INDICATES SOME
THUNDERSTORMS MAY REACH NW OHIO BY MID AFTERNOON. I HAVE ADDED A
SLIGHT CHANCE OF THUNDERSTORMS FOR THIS AFTERNOON FOR THE
NORTHWEST PART OF OUR COUNTY WARNING AREA. I WILL MONITOR THE
TRENDS AND THE PRECIPITATION CHANCES MAY NEED TO BE INCREASED WITH
THE NEXT UPDATE. TEMPERATURES APPEAR TO BE ON TRACK. 12Z DTX
SOUNDING INDICATES A MAX TEMP OF 88 WITH FULL SUN. THE ONLY
LIMITING FACTOR COULD BE THE CLOUD COVER FROM THE MCS. HOWEVER
WITH DEWPOINTS IN THE MID 70S AND THE RECENT COOL
SPELL...TEMPERATURES NEAR HEAT INDEX CRITERIA WILL FEEL VERY
UNCOMFORTABLE FOR MOST. I WILL LEAVE THE HEAT ADVISORY UNCHANGED.
PREVIOUS FORECAST...
THE SLIGHTLY DRIER AIR THAT WAS OVER INDIANA EARLIER IN THE NIGHT
HAS SPREAD ACROSS NW OHIO. THIS HAS CAUSED DEWPOINTS TO DIP INTO
THE MIDDLE 60S. THIS DRYING WILL BE BRIEF AS DEWPOINTS WILL CLIMB
BACK INTO THE 70S SHORTLY. SOME DEBRIS CLOUDS FROM THE CONVECTION
OVER WISCONSIN WILL EVENTUALLY FIND THEIR WAY TO THE AREA. THESE
SHOULD BE THIN SO NO CHANGES TO TEMPS.
PREVIOUS...NO CHANGES TO THE HEAT ADVISORY TODAY. WESTERN AREAS
WILL REACH MINIMAL CRITERIA. EXPECT SURFACE DEWPOINTS TO SURGE
INTO THE MIDDLE 70S BY 18Z. MIXING LATE IN THE AFTERNOON MAY CAUSE
THEM TO DROP BACK INTO THE LOWER 70S. GIVEN HOW GREEN AND MOIST IT
IS AT GROUND LEVEL CANNOT SEE TEMPS GETTING WARMER THAN GUIDANCE
NUMBERS TODAY. ABOUT THE WEST HALF OF THE AREA SHOULD REACH 90
WITH UPPER 80S MOST OF THE REST OF THE AREA.
THE NEXT CHALLENGE TODAY WILL BE PRECIP CHANCES. CURRENTLY A FEW
STORMS OVER EASTERN LAKE ERIE. THESE MAY CLIP NW PA THE NEXT FEW
HOURS. AFTER THAT AM GOING TO TRY FOR A DRY FORECAST. EVEN THOUGH THERE
WILL BE VERY IMPRESSIVE CAPES OF 4000 J/KG LATER TODAY DO NOT SEE
A SUITABLE LIFTING MECHANISM. IT IS POSSIBLE THAT THE LAKE BREEZE
BOUNDARY COULD KICK OFF A FEW STORMS BUT GIVEN THE FACT THAT 700MB
TEMPS WILL REACH PLUS 10 TODAY...THE ATMOSPHERE WILL BE CAPPED. DO
EXPECT A FEW POP UPS THIS AFTERNOON BUT COVERAGE WILL BE NO MORE
THAN 5 PERCENT SO COMFORTABLE GOING DRY. THE CURRENT ACTIVITY NEAR
CHICAGO SHOULD DISSIPATE AND ACTIVITY MOVING INTO WISCONSIN SHOULD
PASS TO THE NORTH IF IT HOLDS TOGETHER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HUMID AIR WILL REMAIN OVER THE AREA TONIGHT AND SUNDAY. WILL START
TO SEE INCREASING PRECIP CHANCES LATE TONIGHT AS MID LEVELS BEGIN
TO SLOWLY COOL. BETTER CHANCES WILL COME SUNDAY AFTERNOON AND
EVENING AS A COLD FRONT APPROACHES FROM THE NORTHWEST. THIS FRONT
WILL BE SOUTH OF THE AREA BY DAYBREAK MONDAY. THE AREA WILL BE
OUTLOOKED FOR SEVERE WEATHER WITH THE FRONTAL PASSAGE AND THIS
SEEMS REASONABLE GIVEN THE AIRMASS. THE AREA COULD SEE A SQUALL
LINE DEVELOP AND MOVE THROUGH LATE SUNDAY. HAVE BUMPED PRECIP
CHANCES TO THE LIKELY CATEGORY ALL AREAS BASED ON THIS SCENARIO.
BY DAYBREAK MONDAY THE ENTIRE AREA SHOULD BE DRY. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION RESULTING IN DRY WEATHER THROUGH
THE END OF THE PERIOD.
GIVEN THE PRECIP AND MORE CLOUDS EXPECTED ON SUNDAY...TEMPS WILL
BE A TAD COOLER THAN TODAY. SHOULD NOT NEED ANY HEAT HEADLINES.
THE AIRMASS BEHIND THE FRONT DOES NOT APPEAR TO BE QUITE AS COOL
AS EARLIER THOUGHT SO HAVE BUMPED HIGH TEMPS UP A LITTLE FOR
MONDAY AND A FEW DEGREES FOR TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
STRETCH OF DRY WEATHER SEEMS TO BE SETTING UP FOR THE LONG RANGE.
MODELS CONTINUE TO BE IN GOOD AGREEMENT FOR WEDNESDAY WITH SURFACE
HIGH PRESSURE MOVING SE OVER THE ENTIRE AREA. MODELS NOW INDICATE
SURFACE HIGH TO REMAIN OVER THE AREA INTO THE WEEKEND. YDY ECMWF
HAD SHORT WAVE MOVING ACROSS THE AREA ON FRIDAY. NOW THE ECMWF IS
COMING INTO LINE WITH THE GFS...KEEPING HIGH PRESSURE OVER THE
ENTIRE AREA INTO NEXT WEEKEND. SO HAVE REMOVED ALL MENTION OF
PRECIP FOR THE LONG RANGE FORECAST.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
PREDOMINATELY VFR CONDITIONS WILL CONTINUE TODAY. THIS AFTERNOON
CAPES SOAR TO 5,000 J/KG. HOWEVER WELL CAPED AT 700MB WITH NO
DISCERNIBLE TRIGGER. THAT SAID COULD SEE ISOLATED TSRA POP UP
ALMOST ANYWHERE THIS AFTERNOON...HOWEVER DID NOT PUT ANY TSRA IN
TAF BECAUSE IS SHOULD BE ISOLATED.
&&
.MARINE...
POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS TODAY...BUT
OTHER THAN THAT THE LAKE WILL BE RATHER QUIET THIS WEEKEND AS HIGH
PRESSURE REMAINS OVER THE OHIO VALLEY. MODELS CONTINUE TO HOLD OFF
NEXT COLD FRONT UNTIL MONDAY. CONDITIONS MAY GET CHOPPY FOR A TIME
AS WIND SPEEDS INCREASE TO 15 KNOTS...BUT WILL REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ003-006>009-
017>019-027-028-036.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...GARNET
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
607 AM EDT SAT JUL 18 2015
.SYNOPSIS...
HOT AND HUMID FOR THE WEEKEND. SOME AFTERNOON THUNDERSTORMS
POSSIBLE. COLD FRONT IN VICINITY EARLY IN WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
NAM DOES NOT HAVE THE COMPLEX MOVING THROUGH EARLY THIS MORNING...SO
NOT SURE THAT THE MOISTURE FIELDS ARE REPRESENTATIVE AT LATER TIMES.
THEREFORE WILL RELY MORE ON THE HRRR AND THE GFS WHICH HANDLE THE
COMPLEX A BIT BETTER...THOUGH NOT PERFECTLY. THIS WILL ALLOW FOR
SOME THUNDERSTORMS TODAY...BUT DRY AIR PUNCHING IN FROM THE WEST
WILL LIMIT ACTIVITY TO THE MOUNTAINS BY LATER THIS AFTERNOON. THIS
DRY AIR WILL ALSO CAP THE AREA DURING THE EVENING AND OVERNIGHT
HOURS. WITH THE MOIST GROUND...MET MOS LOOKS WAY TO HIGH FOR TODAYS
HIGHS. WILL STAY CLOSER TO THE GFS MOS.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
A VERY SIMILAR DAY AS TODAY
IS EXPECTED ON SUNDAY WITH JUST AN ISOLATED SHOT A SHOWER OR STORM
AND MAINLY OVER THE HIGH TERRAIN. BY SUNDAY EVENING...A S/W TROF AND
ASSOCIATED COLD FRONT WILL MAKE A RUN INTO THE AREA WITH A LINE OF
SHOWERS AND STORMS...SOME OF WHICH MAY BE ON THE STRONG SIDE OVER SE
OH. HAVE SOME LIKELY POPS OVER MUCH OF THE AREA SUNDAY NIGHT UNTIL
THE TROF CAN PASS AND THE FRONT SLIP S. WHILE THE UPPER LEVEL
DISTURBANCE PASSES SAFELY THRU...THE SAME CANNOT BE SAID FOR THE
SURFACE BOUNDARY WHICH WILL RETURN N INTO THE AREA LATE MONDAY AND
BECOME NEARLY QUASI STATIONARY. THIS COMBINED WITH GOOD INSTABILITY
AND SOME PERTURBATIONS IN THE UPPER LEVEL FLOW...MEANS A RENEWED
FLASH FLOOD THREAT MONDAY NIGHT AND TUESDAY.
THINK BEST SHOT OF REACHING HEAT ADV CRITERIA ON SUNDAY WOULD
GENERALLY BE ALONG AND S OF I64. OTHERWISE...UPPER 80S TO LOW 90S
COMBINED WITH DEWPOINTS IN THE LOW 70S MEANS HEAT INDICES IN THE MID
TO UPPER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
COLD FRONT WILL MOVE INTO THE AREA ON MONDAY. THERE IS THE
POTENTIAL FOR A FEW STRONG TO SEVERE STORMS ON MONDAY...BUT THIS
IS STILL UP IN THE AIR A BIT...AND WILL RELY SOMEWHAT ON TIMING OF
FRONT. FRONTAL BOUNDARY WILL EVENTUALLY STALL OUT ACROSS THE
SOUTHERN HALF OF THE AREA BRIEFLY...BEFORE SAGGING SOUTH LATER IN
THE DAY ON TUESDAY. HOWEVER...ANOTHER SYSTEM WILL AFFECT THE AREA
MID TO LATE WEEK. THUS...HEADING INTO YET ANOTHER WET
PERIOD...WITH THE POTENTIAL FOR CONTINUED WATER PROBLEMS.
HIGHLIGHTED IN THE HWO.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SOME SHOWERS AND THUNDERSTORMS WILL CAUSE SOME BRIEF RESTRICTIONS
EARLY THIS MORNING...OTHERWISE GENERALLY VFR CONDITIONS WILL
PREVAIL.A CUMULUS DECK WILL THEN FORM TODAY...STARTING A BIT
LOWER THAN NORMAL DUE TO THE HIGH HUMIDITY. SOME SCATTERED AFTERNOON
THUNDERSTORMS CAN BE EXPECTED IN THE MOUNTAINS. THESE ARE NOT
EXPECTED TO LINGER INTO THE EVENING HOURS AS DRY AIR WILL PUSH IN
FROM THE WEST. SOME MVFR FOG IS POSSIBLE SATURDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS...
DUE TO THE SCATTERED AND LIMITED NATURE OF ANY IFR/MVFR CONDITIONS
IN SHOWERS AND THUNDERSTORMS...SPECIFIC CONDITIONS ARE NOT INCLUDED
IN THE TAFS.
AFTER 12 SUNDAY...
IFR IN MORE WIDESPREAD SHOWERS/STORMS SUNDAY NIGHT OR MONDAY NEAR
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...SL
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
953 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT SATURDAY...
LITTLE REMAINS OF THE EARLIER DYING MCS THAT ENTERED THE REGION
EARLIER THIS MORNING. AT BEST...ISOLATED TO PATCHY LIGHT RAIN
SHOWERS WERE STILL NEAR AND NORTHEAST OF ROANOKE VIRGINIA ALONG
THE INTERSTATE-81 CORRIDOR. PLENTY OF RESIDUAL CLOUD COVER
CONTINUES TO EXIST ACROSS THE CENTRAL PORTION OF THE FORECAST
AREA...AND IS SLOW DRIFTING EASTWARD. THE FAR WESTERN AND
SOUTHEASTERN PARTS OF THE AREA ARE RECEIVING MOSTLY SUNNY TO SUNNY
CONDITIONS. IT WILL BE THESE TWO LOCATIONS THAT WILL HAVE THE BEST
OPPORTUNITY OF SHOWER AND THUNDERSTORM DEVELOPMENT HEADING INTO
THE AFTERNOON HOURS. WHILE THE CENTRAL PORTION OF THE AREA WILL
EVENTUALLY HAVE SOME SUNSHINE...IT WILL BE LATER IN THE DAY...AND
THIS REGION WILL BE SLOWER TO EXPERIENCE SURFACE BASED CONVECTION
DEVELOP. THAT IS NOT TO SAY THAT ACTIVITY THAT FORMS IN THE WEST
MAY NOT MOVE INTO CENTRAL PORTIONS LATER THIS AFTERNOON. THE
LATEST FORECAST UPDATE WILL REFLECT NO MAJOR CHANGES IN THE BIG
PICTURE TODAY. HOWEVER...IN THE NEAR TERM...A GREATER DISTINCTION
HAS BEEN MADE WHERE NO PRECIPITATION IS EXPECTED OVER THE NEXT FEW
HOURS VERSUS WHERE SCATTERED ACTIVITY IS EXPECTED. LIKEWISE...A
SIMILAR DISTINCTION HAS BEEN MADE TO CLOUDY VERSUS MOSTLY SUNNY TO
SUNNY AREAS.
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 AM EDT SATURDAY...
CLUSTERS OF SHRA/TSRA CONTINUE OVER PARTS OF THE MOUNTAINS EARLY
THIS MORNING...BUT MAINLY REMOVED FROM ANY OF THE TAF SITES.
EXPECT A FEW ADDED SHOWERS MAY AFFECT KBLF/KLWB THROUGH MID
MORNING SO INCLUDING MAINLY A VCSH/VCTS FOR A COUPLE MORE HOURS
THIS MORNING. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO KBCB
AND KROA BUT TOO IFFY TO INCLUDE A VCSH MENTION FOR NOW.
ADDITIONAL SHOWER DEVELOPMENT MAY PUSH INTO EASTERN SECTIONS
THIS MORNING AS WELL WITH DEBRIS CLOUDS MAKING FOR LINGERING LOW
END VFR TO MVFR CIGS OVER THE WEST AND THROUGH MIDDAY. SHOULD
FINALLY SEE A RETURN TO VFR FOR A WHILE THIS AFTERNOON AS HEATING
WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN THE LEE OF
THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES WITH
AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE MID
DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON AROUND
4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST AND
ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR HEATING
TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
ANY LINGERING SHOWERS SHOULD EXIT THE EAST/SOUTH THIS EVENING
FOLLOWED BY CLEARING SKIES UNDER LIGHT WINDS. THIS MAY LEAD TO FOG
DEVELOPMENT ESPCLY IN THE VALLEYS OVERNIGHT AND AT ANY LOCATION
THAT SEES HEAVIER DOWNPOURS TODAY. APPEARS KLWB LIKELY TO DROP
DOWN TO LIFR IN FOG/STRATUS WITH MVFR TO IFR AT KBCB AND PERHAPS A
PERIOD OF MVFR OR WORSE AT KLYH/KDAN LATE TONIGHT.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
654 AM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 AM EDT SATURDAY...
CLUSTERS OF SHRA/TSRA CONTINUE OVER PARTS OF THE MOUNTAINS EARLY
THIS MORNING...BUT MAINLY REMOVED FROM ANY OF THE TAF SITES.
EXPECT A FEW ADDED SHOWERS MAY AFFECT KBLF/KLWB THROUGH MID
MORNING SO INCLUDING MAINLY A VCSH/VCTS FOR A COUPLE MORE HOURS
THIS MORNING. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO KBCB
AND KROA BUT TOO IFFY TO INCLUDE A VCSH MENTION FOR NOW.
ADDITIONAL SHOWER DEVELOPMENT MAY PUSH INTO EASTERN SECTIONS
THIS MORNING AS WELL WITH DEBRIS CLOUDS MAKING FOR LINGERING LOW
END VFR TO MVFR CIGS OVER THE WEST AND THROUGH MIDDAY. SHOULD
FINALLY SEE A RETURN TO VFR FOR A WHILE THIS AFTERNOON AS HEATING
WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN THE LEE OF
THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES WITH
AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE MID
DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON AROUND
4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST AND
ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR HEATING
TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
ANY LINGERING SHOWERS SHOULD EXIT THE EAST/SOUTH THIS EVENING
FOLLOWED BY CLEARING SKIES UNDER LIGHT WINDS. THIS MAY LEAD TO FOG
DEVELOPMENT ESPCLY IN THE VALLEYS OVERNIGHT AND AT ANY LOCATION
THAT SEES HEAVIER DOWNPOURS TODAY. APPEARS KLWB LIKELY TO DROP
DOWN TO LIFR IN FOG/STRATUS WITH MVFR TO IFR AT KBCB AND PERHAPS A
PERIOD OF MVFR OR WORSE AT KLYH/KDAN LATE TONIGHT.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS PUEBLO CO
310 PM MDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 310 PM MDT SAT JUL 18 2015
...A WET DAY LIKELY TOMORROW AFTERNOON...
CURRENTLY...
TWO DISTURBANCES OF NOTE...THE FIRST WAS MOVING OVER THE CENTRAL
PART OF COLORADO. A BROAD LINE OF SHOWERS AND THUNDERSTORMS EXTENDED
NNE-SSW WITH THIS DISTURBANCE AND WAS LOCATED OVER THE CENTRAL PART
OF THE STATE. THE 2ND DISTURBANCE WAS OVER SOUTHERN CALIF/LAS VEGAS
REGION. QUITE A BIT OF CONVECTION WAS ASSOCIATED WITH THIS 2ND
DISTURBANCE.
REST OF TODAY AND TONIGHT...
COULD SEE 2 MCS`S DEVELOP LATE THIS AFTERNOON/EVENING. THE FIRST
WILL BE OVER NE CO AND THE 2ND COULD BE FARTHER SOUTH OVER SE
COLORADO. ALTHOUGH BEST FORCING IS LIFTING OFF NORTHEAST TOWARDS NE
CO...THE BETTER INSTABILITY IS LOCATED OVER SE COLO. NEW 18Z NAM IS
CATCHING ON TO THIS POSSIBILITY. HRRR ALSO SHOWS MODEST TO STRONGER
CONVECTION EXTENDING N-S ALONG THE HI PLAINS LATER THIS EVENING. 12
GFS WAS NOT SHOWING MUCH OF ANYTHING OVER THE HI PLAINS ADJ TO COLO
LATER THIS EVENING. ATTM...I HAVE HI ISOLD POPS ALONG MOST OF THE I-
25 CORRIDOR BECOMING SCTD POPS OVER THE FAR EASTERN PLAINS LATER
THIS EVENING.
PRECIP WILL LIKELY LINGER INTO THE EARLY MORNING HOURS ALL AREAS
GIVEN THE MOISTURE PLUME OVER THE REGION...AND HAVE KEPT LOW POPS
MOST AREAS.
WE COULD STILL SEE A FEW MARGINAL SEVERE STORMS TODAY ACROSS THE
REGION...ESPECIALLY EL PASO AND THE FAR E PLAINS.
TOMORROW...
QUITE A BIT OF CLOUDS WILL LIKELY BE OVER THE REGION TOMORROW
MORNING. GUIDANCE IS NOT SHOWING ANY LOW CIGS GIVEN THE WIND
FLOW...BUT IF THE MCS`S BECOME QUITE STRONG THEN SOME LOW STRATUS
COULD DEVELOP OVER THE REGION EARLY TOMORROW.
TOMORROW THE GUIDANCE IS RATHER HIGH WITH POPS MOVING OVER THE
REGION...AND GIVEN THE WELL DEFINED DISTURBANCE OVER THE CALIF
REGION...THESE VALUES ARE WARRANTED. PRECIP SHOULD DEVELOP RATHER
EARLY IN THE MTNS AND MOVE EASTWARD W/TIME. I PAINTED HIGH
SCTD/LIKELY POPS OVER THE MTNS...ESPECIALLY THE CONTDVD. FLASH
FLOODING OVER THE HI TRRN COULD OCCUR...BUT WILL DEFER TO LATER
SHIFTS TO ISSUE ANY HILITES.
FOR THE PLAINS...ALTHOUGH ALL GUIDANCE BLOWS UP CONVECTION OVER THE
HI PLAINS TOMORROW...THEY ARE HAVING A PROBLEM WITH LOCATION. EC HAS
THE MCS BLOWING UP RELATIVELY EARLY OVER EAST CENTRAL CO...THE NAM
APPEARS TO ONCE AGAIN DEVELOP A COUPLE OF MCS`S OVER THE HI PLAINS
WHILE THE GFS IS OVER NE COLORADO. WPC HAS THE BULLSEYE OVER EC
COLO. FOR NOW PAINTED SCTD POPS OVER THE PLAINS BY LATE AFTERNOON
TOMORROW. WE WILL ALSO LIKELY SEE SOME HEAVY RAIN LATE TOMORROW
AFTERNOON OVER THE LOWER ELEVATIONS AND HAVE PAINTED MDT RAIN IN THE
NDFD.
STRONG TO MARGINALLY SVR STORMS WILL ONCE AGAIN BE POSSIBLE TOMORROW
AFTERNOON ACROSS THE REGION. /HODANISH
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 310 PM MDT SAT JUL 18 2015
LITTLE CHANGE TO THE EXPECTED WEATHER TREND THROUGH THE
EXTENDED...WITH A SLIGHTLY SLOWER PROGRESSION OF THE REMNANTS OF
TROPICAL STORM DOLORES.
SUNDAY NIGHT THROUGH TUESDAY...THE FLAT UPPER RIDGE WILL REMAIN
LOCKED OVER THE SOUTHERN U.S. THROUGH THE EXTENDED PERIOD...BUT A
COUPLE OF DISTURBANCES WILL KEEP THE PATTERN ACTIVE THROUGH TUE.
FIRST...AN UPPER SHORTWAVE WILL CROSS MT AND WY SUN EVE...PUSHING A
FRONT DOWN ACROSS THE PALMER DVD AND SOUTHEASTERN PLAINS ON MON. THE
SECOND FEATURE WILL BE THE REMNANTS OF DOLORES...WHICH IS FORECAST
TO TRACK EAST ACROSS THE GREAT BASIN ON MON AND COLORADO ON TUE.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH AFTN AND EVE
ACROSS ALL OF THE FORECAST AREA...WITH LINGERING ISOLATED ACTIVITY
INTO THE NIGHT. ACROSS THE MTS AND IMMEDIATELY ADJACENT
PLAINS...CONVECTION WILL BE LIKELY THROUGH THE AFTN AND EARLY EVE
HOURS. THIS INCREASED ACTIVITY AND CLOUD COVER IS EXPECTED TO KEEP
MAX TEMPS BELOW NORMAL...WITH 80S ACROSS THE PLAINS AND 70S FOR THE
HIGH VALLEYS SUNDAY THROUGH TUESDAY. THERE IS THE POTENTIAL FOR
HEAVIER RAINFALL EACH DAY THROUGH THE LATE AFTN AND EARLY EVE
HOURS...SO THERE WILL BE THE HEIGHTENED THREAT OF FLASH FLOODING FOR
AREA BURN SCARS.
WEDNESDAY THROUGH SATURDAY...A MORE WEST TO SOUTHWEST FLOW ALOFT
THEN DEVELOPS ACROSS THE 4 CORNERS STARTING WED AND LASTING INTO THE
WEEKEND...AS UPPER HIGH PRESSURE REACHES BACK ACROSS NM AND AZ...AND
ANOTHER UPPER LOW PRES TROUGH STARTS TO DIG DOWN OVER THE PAC NW.
WED LOOKS TO BE A TRANSITIONAL DAY FOR THE WEATHER PATTERN...SO PCPN
CHANCES WILL BE ON THE DECREASE WED AS TEMPS START TO GRADUALLY
WARM. MODELS INDICATE THE AVAILABLE MOISTURE TAP WILL BE SUPPRESSED
TO THE SOUTH OF CO THROUGH THIS PERIOD...WITH JUST ISOLATED DIURNAL
MOUNTAIN CONVECTION FORECAST. TEMPS WILL WARM BACK UP TO NEAR
SEASONAL NORMS...WITH MAX READINGS IN THE 90S FOR THE PLAINS AND 80S
FOR THE HIGH VALLEYS. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 310 PM MDT SAT JUL 18 2015
KCOS...TSRA ARE LIKELY LATER THIS AFTERNOON/EARLY EVENING. GUSTY
WINDS AND BRIEF HEAVY RAIN AND POSSIBLY SMALL HAIL POSSIBLE. SHOULD
SEE VFR TONIGHT AND TOMORROW...BUT WILL ONCE AGAIN SEE SOME MORE
TSRA BY TOMORROW AFTERNOON AT COLORADO SPRINGS.
KPUB...ISOLD TSRA POSSIBLE THIS LATE AFTERNOON AND EVENING. WE WILL
LIKELY SEE A GUST FRONT MOVE ACROSS THE REGION EARLY THIS EVENING
ASSOCIATED WITH THE CONVECTION. OTHERWISE VFR EXPECTED. MORE TSRA
ACTIVITY IS LIKELY TOMORROW AFTERNOON.
KALS...LOTS OF MOISTURE AROUND IN THE MTNS AND ISOLD TO SCTD TSRA
WILL OCCUR THIS AFTERNOON AND TOMORROW AFTERNOON. SHOULD SEE VFR
OUTSIDE THE STRONGER TSRA ACTIVITY. GUSTY WINDS WILL BE POSSIBLE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOORE
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1016 AM MDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 952 AM MDT SAT JUL 18 2015
EARLY MORNING LIGHTNING THIS MORNING IN UTAH ABOUT THE HEAD INTO
WESTERN COLORADO...BUT ALL QUIET IN EASTERN COLORADO. ONE WEAK
FRONT CAME OVERNIGHT...AND THERE ARE SOME PRESSURE RISES IN
EASTERN WYOMING AND NORTHWEST NEBRASKA THAT MAY BE ASSOCIATED WITH
ANOTHER WEAK FRONT.
MODELS DO NOT HAVE CONVECTION ON THE PLAINS UNTIL MID
AFTERNOON...AND HAVE SLOWED THE ARRIVAL OF THUNDERSTORMS ON THE
PLAINS THIS AFTERNOON. STILL LOOKS LIKE WE WILL HAVE SCATTERED TO
LIKELY THUNDERSTORMS IN NORTHEAST COLORADO BY THIS EVENING...AND
SOME OF THOSE STORMS BORDERING GOODLAND AREA MAY LINGER LATE. NAM
IS RATHER EXCITABLE WITH CAPES OVER 2000 TONIGHT OVER NORTHEAST
COLORADO...WILL BE INTERESTING TO SEE WHAT OTHER 12Z MODELS DO.
INITIAL THOUGHT IS SPC SLIGHT RISK APPEARS TO BE A BIT TOO FAR
WEST.
MODELS SHOW GOOD EASTERLY FLOW THIS EVENING AND GOOD
SATURATION OF THE BOUNDARY AREA...SO STRATUS AND PATCHY FOG
LOOKING VERY POSSIBLE AFTER 09Z OVER MUCH OF EASTERN COLORADO.
THESE CLOUDS SHOULD LINGER THROUGH MID MORNING MONDAY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 308 AM MDT SAT JUL 18 2015
SWLY FLOW ALOFT WILL BE OVER THE AREA TODAY THRU TONIGHT. AT THE
SFC A WK SURGE MOVED ACROSS NERN CO LAST EVENING BUT HAS PRETTY
MIXED OUT THE LAST FEW HOURS. OVERALL AM GETTING CONFLICTING
SIGNALS ON HOW THE SFC PTRN IS GOING TO EVOLVE THIS AFTN. THE NAM
AND HIRES MODEL WANT TO BRING ANOTHER SURGE INTO NERN CO BY MIDDAY
WHILE THE HRRR AND RAP KEEP THIS BNDRY FURTHER NORTH OVER SERN WY
AND WRN NE THRU THE AFTN HOURS. AS A RESULT DEWPOINTS MIX OUT INTO
THE 30S AND 40S IN THE RAP AND HRRR WHILE THE NAM AND HIRES KEEP
THEM IN THE 50S. FURTHERMORE THIS LEADS TO LARGE DIFFERENCES IN
FCST CAPE BY MID TO AFTN WITH 2000 J/KG OR MORE ACROSS NERN CO AS
SHOWN BY THE NAM WITH 500-1000 J/KG IN THE HRRR AND RAP. ANOTHER
PROBLEM TO CONSIDER IS THAT EVEN IF THE NAM IS CORRECT WITH THE MUCH
HIGHER CAPE VALUES IT HAS A DECENT CAP IN PLACE THRU THE AFTN ACROSS
ALL OF NERN CO. IN ADDITION THERE IS SOME MID LVL DESCENT SHOWN AS
WELL THRU THE AFTN HOURS WHICH COULD LIMIT TSTM ACTIVITY AS WELL.
AT THIS POINT THERE ARE SO MANY CONFLICTING SIGNALS EVEN IF I ADJUST
THINGS I COULD GO IN THE WRONG DIRECTION SO WILL LEAVE INHERITED
POPS ALONE FOR THE AFTN HOURS. NATURALLY IF THE HIGHER CAPE VALUES
ARE IN PLACE AND THE CAP IS BKN THERE WOULD CERTAINLY BE THE
POTENTIAL FOR SOME SVR STORMS DUE TO FAVORABLE SHEAR. CIPS GUIDANCE
SHOWS THE HIGHEST POTENTIAL OVER THE NERN PLAINS MAINLY NE OF A LINE
FROM BRIGGSDALE TO WIGGINS TO LAST CHANCE.
OVER THE HIGHER TERRAIN STORMS WILL BE HIGH BASED AND PRODUCE GUSTY
WINDS BUT LIMITED RAINFALL. MEANWHILE ANOTHER PROBLEM FOR TODAY IS
HIGH TEMPERATURES. DEPENDING ON THE TIMING OF THE COOL FNT HIGHS
COULD EASILY RISE BACK INTO THE LOWER TO MID 90S ACROSS NERN CO IF
THE FNT IS SLOWER LIKE THE RAP/HRRR SHOW. FOR NOW WILL KEEP
READINGS IN THE MID 80S TO NR 90 HOWEVER THEY MAY END UP BEING TOO
COOL.
FOR THIS EVENING LOW LVL MOISTURE WILL INCREASE OVER THE PLAINS
BEHIN THE COOL FNT AS SOME WK MID LVL ASCENT MOVE ACROSS. THIS
SHOULD LEAD TO A BETTER CHC OF STORMS ACROSS NERN CO WITH SOME OF
THE ACTIVITY POSSIBLY LINGERING AFTER MIDNIGHT OVER THE FAR NERN
PLAINS. ONCE AGAIN THERE WILL BE THE POTENTIAL FOR A FEW SVR
STORMS ALONG WITH SOME HEAVY RAINFALL WELL DUE TO INCREASING
PRECIPITABLE WATER VALUES. LATE TONIGHT WITH SEE AREAS OF STRATUS
DVLP OVER MUCH OF NERN CO DUE TO UPSLOPE FLOW AND INCREASING LOW
LVL MOISTURE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 308 AM MDT SAT JUL 18 2015
INCREASED MOISTURE THROUGH THE BEGINNING OF THE WEEK WILL INCREASE
CONVECTION WITH SLIGHTLY BELOW AVERAGE TEMPERATURES. LOOK FOR DRIER
AND WARMER CONDITIONS TOWARD THE END OF THE WEEK.
SUNDAY WILL BRING MOSTLY CLOUDY CONDITIONS WITH SLIGHTLY COOLER
TEMPERATURES DUE IN PART TO A FRONT THAT WILL PUSH THROUGH THE
REGION EARLIER IN THE MORNING. MOISTURE PW VALUES WILL INCREASE ABOVE
1 INCH WITH ENHANCED UPSLOPE FLOW. WARMING AND THEREFORE CONVECTION
WILL BE INHIBITED THROUGH THE DAY BY CLOUD COVER AND MID LEVEL
STABILITY. WILL MAINTAIN SCATTERED STORMS OVER THE MOUNTAINS WITH
ONLY ISOLATED ON THE PLAINS TOWARD THE LATE AFTERNOON AND EVENING.
MAIN THREATS WILL BE HEAVY RAIN AND WINDS WITH THE STORMS.
SUNDAY NIGHT INTO MONDAY WILL SEE STORMS CONTINUING INTO EARLY
MORNING BEFORE DISSIPATING. WESTERLY UPPER LEVEL FLOW INCREASES WITH
A SLIGHT DROP IN PW VALUES AS THE MOISTURE GETS CUTS OFF.
HOWEVER...WITH LINGERING MOISTURE IN THE MOUNTAINS WILL MAINTAIN
INCREASED POPS FOR MONDAY AS AFTERNOON OROGRAPHICS COULD HELP SPARK
SOME CONVECTION IN THE AFTERNOON. HIGHS FOR MONDAY WILL INCREASE
SLIGHTLY FROM SUNDAY INTO THE MID 80S.
TUESDAY AND WEDNESDAY...THE UPPER LEVEL RIDGE THAT IS DOMINATING THE
SOUTHERN PORTIONS OF THE CONUS WILL START TO BREAK DOWN AND MOVE
SOUTH ONCE AGAIN INCREASING SUBTROPICAL MOISTURE OVER THE REGION
TUESDAY AFTERNOON INTO WEDNESDAY. THERE WILL BE INCREASED STORM
COVERAGE TUESDAY AND WEDNESDAY AFTERNOONS. CAPE VALUES ARE NOT
IMPRESSIVE BUT SOME BRIEF HEAVY RAIN AND HIGH WINDS WILL BE POSSIBLE
WITH STORM DEVELOPMENT.
THURSDAY INTO THE START OF THE WEEKEND...MODELS ARE SHOWING A DRIER
AND WARMER PATTERN TAKING PLACE. TEMPERATURES WILL INCREASE INTO THE
LOWER 90S BY THE END OF THE WEEK. WILL KEEP A SLIGHT CHANCE OF
STORMS IN THE MOUNTAINS BUT AT THIS POINT DO NOT SEE MUCH POTENTIAL
FOR DEVELOPMENT OVER THE PLAINS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 308 AM MDT SAT JUL 18 2015
WITHIN THE NEXT HOUR SURFACE WINDS WILL BECOME EASTERLY TURNING
SOUTHEASTLY THIS AFTERNOON. THUNDERSTORMS WILL DEVELOP OVER THE
HIGH TERRAIN AFTER 17Z...AND SPREAD TO THE LOWER ELEVATIONS AFTER
21Z. RIGHT NOW IT LOOKS LIKE SEVERE WEATHER WILL BE OVER THE FAR
NORTHEAST PLAINS...BUT THUNDERSTORMS COULD PRODUCE GUSTY OUTFLOW
WINDS TO 45 MPH THIS BETWEEN 21Z AND 02Z. AFTER 09Z TONIGHT AREAS
OF LOW STRATUS AND PATCHY FOG SHOULD DEVELOP OVER MUCH OF THE
AREA. IF THIS DEVELOPS EXPECT IFR CEILINGS THAT WILL LINGER UNTIL
MID MORNING SUNDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RTG
SHORT TERM...RPK
LONG TERM...BOWEN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
554 PM CDT SAT JUL 18 2015
.MESOSCALE DISCUSSION...
324 PM CDT
MAIN COMPLEX OF THUNDERSTORMS HAS SHIFTED EAST INTO SOUTHWEST
LOWER MICHIGAN AND NORTHWEST INDIANA...HOWEVER SOME STRONGER
STORMS CONTINUE TO PULSE UP FURTHER WEST ACROSS SOUTHERN
COOK/DUPAGE/WILL COUNTIES AND STRETCHING EAST INTO NORTHWEST
INDIANA. A BOUNDARY WAS SLIDING SOUTH ACROSS KANE/DUPAGE/SOUTHERN
COOK COUNTIES...WITH CONSIDERABLE HELICITY FOCUSED ALONG THIS
FEATURE. WINDS TO THE SOUTH OF THE BOUNDARY ARE SOUTHERLY WITH A
CONSIDERABLY WARM/MOIST AIRMASS FEEDING DEW POINTS IN THE MID/UPR
70S NORTHEAST. VISIBLE IMAGERY INDICATES THE CUMULUS FIELD ALONG
AND SOUTH OF THE BOUNDARY ARE NOT GROWING VERTICALLY...HOWEVER IT
IS POSSIBLE THAT AS THE BOUNDARY MOVES INTO THIS CUMULUS LAYER
THAT ADDITIONAL GROWTH MAY OCCUR.
GIVEN HOW UNSTABLE THE ATMOSPHERE REMAINS IN THIS AREA AND
STRETCHING INTO NORTHWEST INDIANA...IT IS PLAUSIBLE THAT RAPID
GROWTH COULD OCCUR AND WITH THE ENHANCED HELICITY THE UPDRAFTS
COULD ROTATE AND PRODUCE A TORNADO OR TWO. FURTHER WEST WINDS HAVE
VEERED TO THE WEST...WHICH HAS DIMINISHED THE TOR THREAT.
SUBSIDENCE WAS BEING NOTED AS DEW POINTS HAVE FALLEN INTO THE
LOWER 70S TO A FEW UPPER 60S ACROSS FAR WESTCENTRAL IL.
BEACHLER
&&
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* OUTFLOW HAS MOVED SOUTH OF THE TERMMINALS... NORTH WINDS
EXPECTED TO PERSIST THROUGH 23000-2330Z BEFORE SOUTHWEST WINDS
RESTABLISH.
* TSRA EXITING THE AREA BEWTEEN 22-23Z.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
ED F
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM TO HIGH CONFIDENCE IN TSRA EXITING TERMINAL AREAS BY
23Z.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
518 PM CDT SAT JUL 18 2015
.MESOSCALE DISCUSSION...
324 PM CDT
THUNDERSTORMS RAPIDLY DEVELOPED ACROSS NORTH/NORTHEAST IL THIS
AFTERNOON...AS A CUMULUS FIELD BEGAN TO COLLIDE WITH THE LAKE
BOUNDARY THAT HAD PUSHED WEST. THIS CONVERGENCE ZONE ADDED TO THE
LIFT...COUPLED WITH IMPRESSIVE MLCAPE VALUES...AND PARCELS WERE
ABLE TO ASCEND RAPIDLY THROUGH A VERY MOIST AND UNSTABLE
ENVIRONMENT. JUST SOUTH OF THE CHICAGO METRO AREA DEW POINTS HAVE
POOLED TO AROUND 80 DEG THIS AFTERNOON...WITH SFC WINDS ACROSS
NORTHWEST INDIANA SLIGHTLY BACKED TO THE SOUTH.
ALONG WITH THE RAPID ASCEND OF PARCELS AND DEVELOPING
UPDRAFTS...THE CONVGENCE ZONE HAS ALSO ALLOWED FOR INCREASED LOW
LEVEL HELICITY. THIS REINFORCES THE RISK FOR SOME ROTATING
UPDRAFTS AND ISOLATED TORNADO HAZARD THIS AFTERNOON/EARLY EVENING.
THE MAIN LOCATIONS FOR THE NEXT COUPLE OF HOURS CONTINUES TO BE
THE FAR NORTHEAST IL/NORTHWEST IN AREAS...INCLUDING THE CHICAGO
METRO AREA SPILLING INTO LAKE MICHIGAN.
AS FOR CONTINUED DEVELOPMENT...HI-RES GUIDANCE DIFFERS ON HOW THE
NEXT FEW HOURS WILL UNFOLD. THE LATEST HRRR SOLUTIONS SUGGEST THE
CLUSTER ACROSS FAR NORTHEAST IL WILL SLIDE SOUTHEAST ALONG THE
CONVERGENCE ZONE AND MAINTAIN STRENGTH INTO NORTHWEST IN...WITH
LITTLE ADDITIONAL DEVELOPMENT. HOWEVER...AS ELUDED TO EARLIER
ABOUT DIFFERING SOLUTIONS RAP AND LOCAL ARW8KM SUGGEST SOME NEW
DEVELOPMENT FURTHER WEST. INVESTIGATING THE VISIBLE IMAGERY AND
THE CUMULUS FIELD WEST OF THE CURRENT CONVECTION LOOKS TO BE LESS
VERTICAL...AND POSSIBLY EVEN THINNING SLIGHTLY. DEW POINTS IN A
FEW UPSTREAM AREAS HAVE ALSO MIXED DOWN TO THE LOW 70S/UPR 60S
WITH WINDS VEERING TO THE WEST AND BECOMING MORE UNIFORM.
BEACHLER
&&
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* OUTFLOW HAS MOVED SOUTH OF THE TERMMINALS... NORTH WINDS
EXPECTED TO PERSIST THROUGH 23000-2330Z BEFORE SOUTHWEST WINDS
RESTABLISH.
* TSRA EXITING THE AREA BEWTEEN 22-23Z.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
ED F
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM TO HIGH CONFIDENCE IN TSRA EXITING TERMINAL AREAS BY
23Z.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 PM CDT SAT JUL 18 2015
.MESOSCALE DISCUSSION...
324 PM CDT
THUNDERSTORMS RAPIDLY DEVELOPED ACROSS NORTH/NORTHEAST IL THIS
AFTERNOON...AS A CUMULUS FIELD BEGAN TO COLLIDE WITH THE LAKE
BOUNDARY THAT HAD PUSHED WEST. THIS CONVERGENCE ZONE ADDED TO THE
LIFT...COUPLED WITH IMPRESSIVE MLCAPE VALUES...AND PARCELS WERE
ABLE TO ASCEND RAPIDLY THROUGH A VERY MOIST AND UNSTABLE
ENVIRONMENT. JUST SOUTH OF THE CHICAGO METRO AREA DEW POINTS HAVE
POOLED TO AROUND 80 DEG THIS AFTERNOON...WITH SFC WINDS ACROSS
NORTHWEST INDIANA SLIGHTLY BACKED TO THE SOUTH.
ALONG WITH THE RAPID ASCEND OF PARCELS AND DEVELOPING
UPDRAFTS...THE CONVGENCE ZONE HAS ALSO ALLOWED FOR INCREASED LOW
LEVEL HELICITY. THIS REINFORCES THE RISK FOR SOME ROTATING
UPDRAFTS AND ISOLATED TORNADO HAZARD THIS AFTERNOON/EARLY EVENING.
THE MAIN LOCATIONS FOR THE NEXT COUPLE OF HOURS CONTINUES TO BE
THE FAR NORTHEAST IL/NORTHWEST IN AREAS...INCLUDING THE CHICAGO
METRO AREA SPILLING INTO LAKE MICHIGAN.
AS FOR CONTINUED DEVELOPMENT...HI-RES GUIDANCE DIFFERS ON HOW THE
NEXT FEW HOURS WILL UNFOLD. THE LATEST HRRR SOLUTIONS SUGGEST THE
CLUSTER ACROSS FAR NORTHEAST IL WILL SLIDE SOUTHEAST ALONG THE
CONVERGENCE ZONE AND MAINTAIN STRENGTH INTO NORTHWEST IN...WITH
LITTLE ADDITIONAL DEVELOPMENT. HOWEVER...AS ELUDED TO EARLIER
ABOUT DIFFERING SOLUTIONS RAP AND LOCAL ARW8KM SUGGEST SOME NEW
DEVELOPMENT FURTHER WEST. INVESTIGATING THE VISIBLE IMAGERY AND
THE CUMULUS FIELD WEST OF THE CURRENT CONVECTION LOOKS TO BE LESS
VERTICAL...AND POSSIBLY EVEN THINNING SLIGHTLY. DEW POINTS IN A
FEW UPSTREAM AREAS HAVE ALSO MIXED DOWN TO THE LOW 70S/UPR 60S
WITH WINDS VEERING TO THE WEST AND BECOMING MORE UNIFORM.
BEACHLER
&&
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN AND GUST TO
ARND 20 KT BEHIND THE THUNDERSTORMS. GUSTS DIMINISH THIS
EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* HIGH CONFIDENCE IN TS THIS AFTN INTO THIS EVENING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
239 PM CDT SAT JUL 18 2015
.SHORT TERM...
957 AM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN AND GUST TO
ARND 20 KT BEHIND THE THUNDERSTORMS. GUSTS DIMINISH THIS
EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* HIGH CONFIDENCE IN TS THIS AFTN INTO THIS EVENING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
236 PM CDT SAT JUL 18 2015
.SHORT TERM...
957 AM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTHEAST WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN. GUSTS
DIMINISH THIS EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM-HIGH CONFIDENCE IN TS OCCURRING AND THE POSSIBILITY OF
STRONG TO SEVERE STORMS. MEDIUM COVERAGE IN TSRA OVER THE
TERMINALS AND EXACT TIMING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
230 PM CDT SAT JUL 18 2015
.SHORT TERM...
957 AM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTHEAST WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN. GUSTS
DIMINISH THIS EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM-HIGH CONFIDENCE IN TS OCCURRING AND THE POSSIBILITY OF
STRONG TO SEVERE STORMS. MEDIUM COVERAGE IN TSRA OVER THE
TERMINALS AND EXACT TIMING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL MIDNIGHT SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT SUNDAY.
HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1252 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1051 AM CDT SAT JUL 18 2015
MCS THAT DEVELOPED OVER SOUTHEAST NEBRASKA/NORTHWEST MISSOURI
EARLIER THIS MORNING CONTINUES TO TRACK EASTWARD AND IS NOW
APPROACHING THE MISSISSIPPI RIVER. IR SATELLITE HAS SHOWN WARMING
CLOUD TOPS WHILE 15-MINUTE LIGHTNING DATA HAS BEEN CONSISTENTLY
DECREASING OVER THE PAST COUPLE OF HOURS. DESPITE THE DISTINCT
DIURNAL WEAKENING TREND...LIGHT RAIN IS SPILLING INTO WEST-CENTRAL
ILLINOIS. MOST MODELS ARE NOT HANDLING THE CURRENT SITUATION
PARTICULARLY WELL...WITH THE 12Z NAM SHOWING THE SYSTEM COMPLETELY
DISSIPATING BEFORE IT REACHES CENTRAL ILLINOIS. MEANWHILE...THE
LATEST HRRR TAKES THE DIMINISHING PRECIP AREA INTO THE HEART OF
THE KILX CWA EARLY THIS AFTERNOON...WITH WIDELY SCATTERED
THUNDERSTORMS DEVELOPING AHEAD OF THE SYSTEM ACROSS EAST-CENTRAL
AND SOUTHEAST ILLINOIS. THINK THIS MAY BE A LITTLE TOO
AGGRESSIVE...SO HAVE FOLLOWED THE RAPID REFRESH MOST CLOSELY FOR
THE SHORT-TERM FORECAST. AS A RESULT...HAVE INCREASED POPS ACROSS
THE W/SW CWA GENERALLY WEST OF THE I-55 CORRIDOR LATE THIS MORNING
INTO THE EARLY AFTERNOON AS THE SYSTEM CROSSES THE MISSISSIPPI
RIVER. THINK IT WILL GRADUALLY FIZZLE...LEAVING BEHIND A MID/HIGH
OVERCAST THROUGH MID-AFTERNOON. FURTHER E/SE...THINK ISOLATED
THUNDERSTORMS WILL DEVELOP ALONG/E OF I-57 THIS AFTERNOON AS
OUTFLOW BOUNDARY INTERACTS WITH VERY UNSTABLE AIRMASS. MAIN STORY
TODAY WILL BE THE HEAT AND HUMIDITY. DESPITE CLOUD COVER FROM MCS
TEMPORARILY HALTING THE TEMP RISE LATE THIS MORNING INTO THE EARLY
AFTERNOON ACROSS THE WESTERN HALF OF THE AREA...A RETURN TO
PARTIAL SUNSHINE LATER IN THE DAY WILL RESULT IN HIGH TEMPS IN THE
LOWER TO MIDDLE 90S ACROSS THE BOARD. HEAT INDEX VALUES WILL
EXCEED ADVISORY CRITERIA...RANGING FROM 105 TO 110.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
LATEST SURFACE ANALYSIS INDICATING A LARGE POOL OF MID TO UPPER 70
DEGREE DEW POINTS SITUATED OVER MOST OF CENTRAL IL WEST THROUGH
EASTERN IOWA. LARGE COMPLEX OF STORMS OVER MINNESOTA AND NORTHERN
IOWA INTO WESTERN WISCONSIN WILL TRACK EAST WITH MOST OF THE HIGH
RESOLUTION MODELS SUGGESTING A REMNANT OUTFLOW BOUNDARY WILL TRACK
EAST AND SOUTHEAST INTO NORTHERN IL BY THIS AFTERNOON AND EVENING.
MEANWHILE...A WEAK SHORTWAVE OVER EASTERN KS HAS HELPED TO PRODUCE
SOME SCATTERED CONVECTION OVER FAR NORTHWEST MISSOURI WITH THE
LATEST HRRR MODEL BRINGING SOME OF THAT PRECIP INTO OUR AREA THIS
AFTERNOON. NOT VERY CONFIDENT ON HOW THE HRRR MODEL HAS BEEN
HANDLING THE PRECIP/CONVECTIVE TRENDS OVER THE PAST SEVERAL DAYS,
ESPECIALLY AFTER ABOUT 6 TO 8 HOURS INTO THE FORECAST WHERE IT IS
WAY OVERBLOWN WITH RESPECT TO CONVECTIVE COVERAGE/INTENSITY. NOT
SURE IF THAT IS A BY-PRODUCT OF THE ADDED EVAPO-TRANSPIRATION OVER
THE MIDWEST...BUT IT HAS HAD A POOR TRACK RECORD FOR A FEW DAYS NOW
AND AM HESITANT TO TAKE ITS SOLUTION AND RUN WITH IT FOR LATER
TODAY.
WE WILL ADD SLIGHT CHANCES ACROSS THE SOUTHEAST THIS AFTERNOON AS
THE COMBINATION OF THE WEAK UPPER LEVEL WAVE TRACKING ACROSS THE
AREA THIS AFTERNOON COMBINED WITH PEAK HEATING AND MIXED LAYER CAPES
IN THE 2500-3000 J/G RANGE MAY BE ENOUGH TO PRODUCE ISOLATED STORMS.
FURTHER NORTH...CONVECTION THAT FIRED OVER NORTHEAST IL AND FINALLY
DISSPATED A FEW HOURS AGO LOOKS TO HAVE PUSHED A WEAK BOUNDARY TO
OUR FAR NORTHEAST COUNTIES...WHICH MAY BE ENOUGH TO PRODUCE AN
ISOLATED STORM THIS AFTERNOON. FOR NOW...WILL HOLD OFF MENTIONING
ANYTHING ACROSS OUR NORTHEAST BUT WE MAY NEED TO ADD LATER THIS
MORNING IF WE SEE SOME RATHER ROBUST CUMULUS DEVELOP ACROSS THE
AREA. FORECAST SOUNDINGS SHOWING AFTERNOON TEMPERATURES SHOULD WARM
SEVERAL DEGREES FROM WHAT WE SAW YESTERDAY AFTERNOOON...MEANING
LOW TO MID 90S FOR HIGHS AND HEAT INDEX VALUES OF 103-109 DEGREES.
WILL CONTINUE WITH THE HEAT ADVISORY THRU EARLY THIS EVENING.
THE COMPLEX OF STORMS TO OUR NORTHWEST EARLY THIS MORNING WILL TRACK
EAST AND A BIT SOUTHEAST AND AS MENTIONED ABOVE...WILL DRAG A OUTFLOW
BOUNDARY EAST/SE INTO NORTHERN IL LATE THIS AFTERNOON WHICH SHOULD BE
ENOUGH TO PRODUCE SCATTERED STORMS. MOST OF THE DETERMINISTIC MODELS
SUGGEST A SOUTHEAST PUSH TO THE STORM CLUSTER LATE THIS AFTERNOON SO
HAVE INCLUDED SLIGHT CHANCES IN OUR FAR NORTHWEST AFTER 21Z/4PM.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 332 AM CDT SAT JUL 18 2015
NOT MANY CHANGES IN THE MID RANGE OF THE FORECAST. WARM TEMPS
CONTINUE TONIGHT WITH PRECIP AND RESIDUAL CLOUD COVER KEEPING ANY
COOLING TO A MINIMUM AS PREFRONTAL PRECIP EDGES INTO THE REGION FROM
THE NW. FRONT ON TRACK TO PUSH THROUGH THE REGION ON SUNDAY AND SO
FAR, THE MODELS ARE PERSISTENT WITH SOME QPF WELL AHEAD OF THE SFC
BOUNDARY. IF THAT TREND CONTINUES, THE TEMPS IN THE FAR EAST AND
SOUTHEAST MAY REMAIN JUST COOL ENOUGH TO KEEP THE HEAT ADVISORY OUT
OF SUNDAY, ALTHOUGH SOME OF THE GUIDANCE HAS TEMPS IN THE SE RATHER
WARM ALONG AND SOUTH OF INTERSTATE 70. NOT ENTIRELY CONVINCED THAT
THE HEADLINE WILL NOT BE EXTENDED...BUT SO FAR THE HEAT INDICES ARE
REMAINING JUST SUB ADVSY LEVEL.
SUNDAY SHOWERS AND THUNDERSTORMS ALSO POTENTIALLY PROBLEMATIC WITH A
WARM AND HUMID AIRMASS OUT AHEAD OF A BOUNDARY, SPC HAS PUT ALL OF
CENTRAL ILLINOIS IN A SLIGHT RISK FOR DAY 2. OVERNIGHT STORMS
TONIGHT MAY ALSO PROVIDE SOME OUTFLOW BOUNDARIES FOR FOCUS OF MORE
STORMS BEFORE THE ACTUAL FROPA. SHEAR MAINLY UNIDIRECTIONAL AND
LIKELY TO BE MORE OF A WIND AND HAIL THREAT AT THIS TIME. A LOT OF
THE SEVERE THREAT WILL BE DICTATED BY THE PREV NIGHT CONVECTION AND
WHAT IS LEFTOVER SUNDAY MORNING TO LIMIT THE ATMOSPHERE RECHARGING.
SUNDAY NIGHT THE PRECIP SHIFTS TO THE SOUTH WITH THE BOUNDARY
SLOWING A IT LOSES ITS PUSH ALOFT AND GETS HUNG UP IN MORE PARALLEL
FLOW. MONDAY/MONDAY NIGHT WILL SEE THE HIGHER POPS IN THE SOUTH,
ALTHOUGH THERE HAS BEEN SOME WAVERING AS TO WHERE THE BOUNDARY WILL
STALL AS ANOTHER WAVE EJECTS OUT OF THE WEST AND RIPPLES UP THE
BOUNDARY REMAINS. SIMILAR PATTERN TO HOW THIS SUMMER HAS BEEN GOING
SO FAR. ECMWF LINGERING PRECIP INTO TUESDAY AND THE SUPERBLEND
HANGING ONTO THE PRECIP. WILL LIKELY REMOVE SHOULD THE OTHER MODELS
CONTINUE THE DRYING TREND TO TUES/WED AS A WEAK NWRLY FLOW
ESTABLISHES ALOFT. A GENERAL WARMING TREND CONTINUES THROUGH THE
WEEK AS THE NEXT PATTERN SHIFT LINES UP FOR THE END OF THE WEEK WITH
A RETURN OF PRECIP CHANCES MOVES IN THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1252 PM CDT SAT JUL 18 2015
CONVECTIVE INITIATION IS CURRENTLY TAKING PLACE AHEAD OF AN
APPROACHING SHORT-WAVE TROUGH ACROSS NORTHEAST IOWA INTO NORTHWEST
ILLINOIS. THESE STORMS SHOULD CONTINUE TO DEVELOP/EXPAND E/SE
ALONG AN OLD OUTFLOW BOUNDARY ACROSS NORTHERN ILLINOIS THIS
AFTERNOON. BASED ON LATEST RADAR IMAGERY AND POSITION OF
OUTFLOW...THINK THESE STORMS WILL STAY NORTH OF THE CENTRAL
ILLINOIS TERMINALS AS THEY TRACK INTO THE CHICAGO AREA BY MID TO
LATE AFTERNOON. AFTER THAT...ADDITIONAL STORMS WILL LIKELY DEVELOP
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST LATER
TONIGHT. 12Z NAM SUGGESTS SCATTERED STORMS ARRIVING AT KPIA AFTER
03Z...THEN AFTER 09Z/10Z FURTHER SOUTHEAST AT KDEC AND KCMI. DUE
TO TIMING AND AREAL COVERAGE UNCERTAINTIES WILL ONLY INCLUDE VCTS
IN THE TAFS AT THIS TIME.
&&
.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.
&&
$$
UPDATE...BARNES
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1251 PM CDT SAT JUL 18 2015
.UPDATE...
957 AM CDT
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.SHORT TERM...
408 AM CDT
TODAY THROUGH SUNDAY...
HEAT...HUMIDITY AND TIMING/COVERAGE OF THUNDERSTORMS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM PERIOD.
A VERY WARM AND HUMID AIR MASS REMAINS IN PLACE ACROSS THE
FORECAST AREA EARLY THIS MORNING...WITH LOW LEVEL THERMAL RIDGE TO
BUILD INTO THE REGION TODAY ON PERSISTENT SOUTH-SOUTHWEST LOW
LEVEL FLOW. LOW LEVEL THERMAL PROGS FROM VARIOUS MODELS SUPPORT
AFTERNOON TEMPS IN THE LOW-MID 90S ACROSS THE CWA...WITH DEW
POINTS IN THE MID-UPPER 70S EXPECTED TO YIELD PEAK AFTERNOON HEAT
INDICES IN THE 105-110 DEGREE RANGE. A HEAT ADVISORY REMAINS IN
EFFECT FOR THE ENTIRE CWA WITH NO CHANGES AT THIS TIME.
SOME COMPLICATIONS EXIST WITH THE FORECAST HOWEVER...PRIMARILY
WITH THE POTENTIAL FOR OUTFLOW FROM MCS CURRENTLY TRACKING ACROSS
WISCONSIN AND ALSO WITH THE POTENTIAL FOR THUNDERSTORMS ACROSS
PORTIONS OF THE CWA TODAY. CONVECTION-ALLOWING GUIDANCE HAS NOT
BEEN HANDLING THE UPPER MIDWEST MCS VERY WELL OVERNIGHT...THOUGH
SOME MODELS PARTICULARLY THE 00Z ARW/NMM-EAST RUNS DO DEPICT A
SOMEWHAT SIMILAR BOWING MCS ACROSS WI...TURNING IT SOUTHEAST A BIT
ACROSS LAKE MICHIGAN THIS MORNING. THIS SEEMS FAIRLY
REASONABLE...AS SPC MESOANALYSIS DEPICTS AN MUCAPE AXIS OF
2000-4000 J/KG FROM THE UPPER MISSISSIPPI VALLEY SOUTHEAST INTO
NORTHERN IL AT 08Z...REASONABLY STEEP MID-LEVEL LAPSE RATES...AND
A 850-300 MB THICKNESS GRADIENT WHICH WOULD FAVOR A SOUTHEASTWARD
PROPAGATION. THE QUESTION IS HOW FAR SOUTH CONVECTION DEVELOPS
ALONG THE IL/WI BORDER AREA THIS MORNING...AND HOW MUCH OF AN
EFFECT OUTFLOW BOUNDARIES NOTED ACROSS EASTERN IA AND LIKELY FROM
SOUTHERN WI WILL HAVE ON OUR TEMP AND DEW POINT TRENDS TODAY.
CURRENT THINKING IS THAT SCATTERED STORMS ALONG SOUTHERN PERIPHERY
OF THE MCS MAY SCRAPE ALONG THE IL/WI BORDER AREA EARLY THIS
AM...MOVING EAST OF THE THE AREA BY MID-LATE MORNING WHICH SHOULD
ALLOW DISSIPATION OF HIGH CLOUDS AND RECOVERY OF TEMPS AND DEW
POINTS BACK INTO FORECAST RANGE THIS AFTERNOON.
ADDITIONAL THUNDERSTORMS ARE EXPECTED BY THIS EVENING...AS A COLD
FRONT TRAILING FROM LOW PRESSURE OVER ONTARIO APPROACHES AND
EVENTUALLY PASSES ON SUNDAY. WHILE MOST GUIDANCE DEPICTS A
SCENARIO OF STORMS INITIATING ALONG/AHEAD OF THE FRONT ACROSS
WISCONSIN AND IOWA THIS AFTERNOON AND MOVING INTO THE AREA THIS
EVENING... LINGERING OUTFLOW BOUNDARIES MAY PROVIDE FOCUS FOR
ISOLATED TO SCATTERED STORMS TO DEVELOP OVER PORTIONS OF THE AREA
THIS AFTERNOON. ONE POSSIBLE FOCUS WOULD BE THE OUTFLOW BOUNDARY
FROM THIS MORNINGS MCS...WHICH WILL LIKELY BE SOMEWHERE OVER FAR
NORTHERN IL THIS AFTERNOON. THUS HAVE ADDED SOME CHANCE POPS BY
EARLY THIS AFTERNOON ACROSS NORTHERN IL. THUNDERSTORM CHANCES WILL
CONTINUE TONIGHT AS THE FRONT MOVES SLOWLY INTO THE REGION...AS
WELL AS ON SUNDAY AS THE BOUNDARY SAGS SOUTH AND EVENTUALLY
SETTLES SOUTH OF THE AREA SUNDAY EVENING. THE WARM/MOIST AIR
MASS...COMBINED WITH OUR LOCATION ALONG THE SOUTHERN PERIPHERY OF
FASTER WESTERLY FLOW ALOFT...WILL SET THE STAGE FOR THE POTENTIAL
FOR SEVERE THUNDERSTORMS MAINLY THIS AFTERNOON/EVENING...AND AGAIN
SUNDAY AFTERNOON. THE ENTIRE CWA IS IN SPC DAY 1 SLIGHT RISK...AND
A DAY 2 SLIGHT RISK MAINLY ACROSS THE SOUTHERN HALF. DAMAGING
WINDS WILL BE THE PRIMARY SEVERE HAZARD...THOUGH LOCALLY BACKED
WINDS ALONG OUTFLOW BOUNDARIES WOULD PRESENT A LOW TORNADO RISK AS
WELL. HIGH PWAT AIRMASS WILL CONTINUE TO PRODUCE TORRENTIAL
RAINFALL AND POTENTIAL FLOODING WITH STORMS AS WELL.
RATZER
&&
.LONG TERM...
415 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
FRONT SLIPS SOUTH OF AREA SUNDAY NIGHT WITH THUNDERSTORM THREAT
ENDING FROM NORTH TO SOUTH DURING THE EVENING ACROSS THE SOUTHEAST
HALF OF THE FORECAST AREA. WEAK HIGH PRESSURE SPREADS ACROSS CENTRAL
IL AND IN BEHIND THE FRONT LATER SUNDAY NIGHT.
FAST WEST-NORTHWEST FLOW ALOFT CONTINUES HOWEVER...WITH A SHORT WAVE
PROGGED TO DIG ACROSS THE WESTERN LAKES AREA MONDAY NIGHT INTO
TUESDAY MORNING...WITH THE PASSAGE OF ANOTHER WEAKER COLD FRONT.
WEAK RETURN FLOW SETS UP MONDAY NIGHT...WITH GUIDANCE SHOWING QUITE
A BIT OF SPREAD IN TIMING AND COVERAGE OF PRECIP INTO TUESDAY. HAVE
MAINTAINED SLIGHT CHANCE POPS DURING THE DAY TUESDAY FROM PREVIOUS
FORECAST FOR NOW WITH HOPEFULLY BETTER MODEL AGREEMENT IN THE
DETAILS AS THE PERIOD DRAWS NEARER.
SURFACE HIGH PRESSURE ONCE AGAIN BUILDS INTO THE AREA TUESDAY NIGHT
AND WEDNESDAY...AS UPPER RIDGE BEGINS TO REBUILD ACROSS THE CENTRAL
CONUS. THIS LOOKS TO PROVIDE A DRY MID-WEEK PERIOD WITH
NEAR/SLIGHTLY BELOW NORMAL TEMPS GENERALLY IN THE LOW 80S. MEDIUM
RANGE GUIDANCE ARE THEN IN DECENT AGREEMENT IN BRINGING A SHORT WAVE
THROUGH THE RIDGE AND ACROSS THE MIDWEST THURSDAY...WITH RETURN FLOW
AND THE NEXT CHANCE OF SHOWER/THUNDERSTORMS DEVELOPING IN ADVANCE AS
THE SURFACE HIGH MOVES OFF TO THE EAST.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTHEAST WINDS CONTINUE TO VEER TO SOUTHWEST THIS AFTN. GUSTS
DIMINISH THIS EVENING.
* PERIODS OF TSRA WITH HEAVY RAIN EXPECTED THIS AFTN. STRONG TO
SEVERE STORMS PROBABLE.
* ANOTHER ROUND OF SHRA AND PERHAPS SOME EMBEDDED TSRA EARLY
SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
A GUST FRONT FROM THE CONVECTION EARLIER THIS MORNING HAS STALLED
FROM BELVIDERE IL THROUGH HIGHLAND INDIANA. WINDS NORTHEAST OF THE
BOUNDARY ARE SLOWLY VEERING FROM NE OR E TO SE...AND EXPECTING
SOUTHWEST WINDS EARLY THIS AFTN. CONDITIONS CONTINUE TO IMPROVE
FOR STORMS. STORMS SHOULD FORM ALONG THE BOUNDARY AND AHEAD OF THE
UPPER LEVEL DISTURBANCE CURRENTLY OVER IOWA THAT IS SHIFTING EAST.
STRONG TO SEVERE STORMS ARE PROBABLE. WHILE CONFIDENCE IS MEDIUM
IN COVERAGE...TIMING...AND EXACT LOCATION...HAVE HIGH CONFIDENCE
THAT THERE SHOULD BE ENOUGH CONVECTION AROUND TO DISRUPT AIR
TRAFFIC. ALL STORMS WILL ALSO PRODUCE TORRENTIAL DOWNPOURS WHICH
WILL LIMIT VISIBILITY.
TSRA PUSHES EAST OF THE TERMINALS THIS EVENING WITH SOUTHWEST
WINDS LESS THAN 15 KT. A COLD FRONT SINKS SOUTHEAST THROUGH THE
REGION SUNDAY MORNING. SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
SHOULD FORM AHEAD OF IT BUT THE NUMBER OF THUNDERSTORMS WILL BE
LIMITED BY HOW STABLE WE ARE BEHIND THIS AFTERNOON/S
THUNDERSTORMS. WINDS SHIFT TO NORTHWEST BEHIND THE COLD FRONT WITH
VFR CONDITIONS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM-HIGH CONFIDENCE IN TS OCCURRING AND THE POSSIBILITY OF
STRONG TO SEVERE STORMS. MEDIUM COVERAGE IN TSRA OVER THE
TERMINALS AND EXACT TIMING.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF -SHRA AND VCTS EARLY
SUNDAY MORNING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1113 AM CDT SAT JUL 18 2015
.UPDATE...
957 AM CDT
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.SHORT TERM...
408 AM CDT
TODAY THROUGH SUNDAY...
HEAT...HUMIDITY AND TIMING/COVERAGE OF THUNDERSTORMS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM PERIOD.
A VERY WARM AND HUMID AIR MASS REMAINS IN PLACE ACROSS THE
FORECAST AREA EARLY THIS MORNING...WITH LOW LEVEL THERMAL RIDGE TO
BUILD INTO THE REGION TODAY ON PERSISTENT SOUTH-SOUTHWEST LOW
LEVEL FLOW. LOW LEVEL THERMAL PROGS FROM VARIOUS MODELS SUPPORT
AFTERNOON TEMPS IN THE LOW-MID 90S ACROSS THE CWA...WITH DEW
POINTS IN THE MID-UPPER 70S EXPECTED TO YIELD PEAK AFTERNOON HEAT
INDICES IN THE 105-110 DEGREE RANGE. A HEAT ADVISORY REMAINS IN
EFFECT FOR THE ENTIRE CWA WITH NO CHANGES AT THIS TIME.
SOME COMPLICATIONS EXIST WITH THE FORECAST HOWEVER...PRIMARILY
WITH THE POTENTIAL FOR OUTFLOW FROM MCS CURRENTLY TRACKING ACROSS
WISCONSIN AND ALSO WITH THE POTENTIAL FOR THUNDERSTORMS ACROSS
PORTIONS OF THE CWA TODAY. CONVECTION-ALLOWING GUIDANCE HAS NOT
BEEN HANDLING THE UPPER MIDWEST MCS VERY WELL OVERNIGHT...THOUGH
SOME MODELS PARTICULARLY THE 00Z ARW/NMM-EAST RUNS DO DEPICT A
SOMEWHAT SIMILAR BOWING MCS ACROSS WI...TURNING IT SOUTHEAST A BIT
ACROSS LAKE MICHIGAN THIS MORNING. THIS SEEMS FAIRLY
REASONABLE...AS SPC MESOANALYSIS DEPICTS AN MUCAPE AXIS OF
2000-4000 J/KG FROM THE UPPER MISSISSIPPI VALLEY SOUTHEAST INTO
NORTHERN IL AT 08Z...REASONABLY STEEP MID-LEVEL LAPSE RATES...AND
A 850-300 MB THICKNESS GRADIENT WHICH WOULD FAVOR A SOUTHEASTWARD
PROPAGATION. THE QUESTION IS HOW FAR SOUTH CONVECTION DEVELOPS
ALONG THE IL/WI BORDER AREA THIS MORNING...AND HOW MUCH OF AN
EFFECT OUTFLOW BOUNDARIES NOTED ACROSS EASTERN IA AND LIKELY FROM
SOUTHERN WI WILL HAVE ON OUR TEMP AND DEW POINT TRENDS TODAY.
CURRENT THINKING IS THAT SCATTERED STORMS ALONG SOUTHERN PERIPHERY
OF THE MCS MAY SCRAPE ALONG THE IL/WI BORDER AREA EARLY THIS
AM...MOVING EAST OF THE THE AREA BY MID-LATE MORNING WHICH SHOULD
ALLOW DISSIPATION OF HIGH CLOUDS AND RECOVERY OF TEMPS AND DEW
POINTS BACK INTO FORECAST RANGE THIS AFTERNOON.
ADDITIONAL THUNDERSTORMS ARE EXPECTED BY THIS EVENING...AS A COLD
FRONT TRAILING FROM LOW PRESSURE OVER ONTARIO APPROACHES AND
EVENTUALLY PASSES ON SUNDAY. WHILE MOST GUIDANCE DEPICTS A
SCENARIO OF STORMS INITIATING ALONG/AHEAD OF THE FRONT ACROSS
WISCONSIN AND IOWA THIS AFTERNOON AND MOVING INTO THE AREA THIS
EVENING... LINGERING OUTFLOW BOUNDARIES MAY PROVIDE FOCUS FOR
ISOLATED TO SCATTERED STORMS TO DEVELOP OVER PORTIONS OF THE AREA
THIS AFTERNOON. ONE POSSIBLE FOCUS WOULD BE THE OUTFLOW BOUNDARY
FROM THIS MORNINGS MCS...WHICH WILL LIKELY BE SOMEWHERE OVER FAR
NORTHERN IL THIS AFTERNOON. THUS HAVE ADDED SOME CHANCE POPS BY
EARLY THIS AFTERNOON ACROSS NORTHERN IL. THUNDERSTORM CHANCES WILL
CONTINUE TONIGHT AS THE FRONT MOVES SLOWLY INTO THE REGION...AS
WELL AS ON SUNDAY AS THE BOUNDARY SAGS SOUTH AND EVENTUALLY
SETTLES SOUTH OF THE AREA SUNDAY EVENING. THE WARM/MOIST AIR
MASS...COMBINED WITH OUR LOCATION ALONG THE SOUTHERN PERIPHERY OF
FASTER WESTERLY FLOW ALOFT...WILL SET THE STAGE FOR THE POTENTIAL
FOR SEVERE THUNDERSTORMS MAINLY THIS AFTERNOON/EVENING...AND AGAIN
SUNDAY AFTERNOON. THE ENTIRE CWA IS IN SPC DAY 1 SLIGHT RISK...AND
A DAY 2 SLIGHT RISK MAINLY ACROSS THE SOUTHERN HALF. DAMAGING
WINDS WILL BE THE PRIMARY SEVERE HAZARD...THOUGH LOCALLY BACKED
WINDS ALONG OUTFLOW BOUNDARIES WOULD PRESENT A LOW TORNADO RISK AS
WELL. HIGH PWAT AIRMASS WILL CONTINUE TO PRODUCE TORRENTIAL
RAINFALL AND POTENTIAL FLOODING WITH STORMS AS WELL.
RATZER
&&
.LONG TERM...
415 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
FRONT SLIPS SOUTH OF AREA SUNDAY NIGHT WITH THUNDERSTORM THREAT
ENDING FROM NORTH TO SOUTH DURING THE EVENING ACROSS THE SOUTHEAST
HALF OF THE FORECAST AREA. WEAK HIGH PRESSURE SPREADS ACROSS CENTRAL
IL AND IN BEHIND THE FRONT LATER SUNDAY NIGHT.
FAST WEST-NORTHWEST FLOW ALOFT CONTINUES HOWEVER...WITH A SHORT WAVE
PROGGED TO DIG ACROSS THE WESTERN LAKES AREA MONDAY NIGHT INTO
TUESDAY MORNING...WITH THE PASSAGE OF ANOTHER WEAKER COLD FRONT.
WEAK RETURN FLOW SETS UP MONDAY NIGHT...WITH GUIDANCE SHOWING QUITE
A BIT OF SPREAD IN TIMING AND COVERAGE OF PRECIP INTO TUESDAY. HAVE
MAINTAINED SLIGHT CHANCE POPS DURING THE DAY TUESDAY FROM PREVIOUS
FORECAST FOR NOW WITH HOPEFULLY BETTER MODEL AGREEMENT IN THE
DETAILS AS THE PERIOD DRAWS NEARER.
SURFACE HIGH PRESSURE ONCE AGAIN BUILDS INTO THE AREA TUESDAY NIGHT
AND WEDNESDAY...AS UPPER RIDGE BEGINS TO REBUILD ACROSS THE CENTRAL
CONUS. THIS LOOKS TO PROVIDE A DRY MID-WEEK PERIOD WITH
NEAR/SLIGHTLY BELOW NORMAL TEMPS GENERALLY IN THE LOW 80S. MEDIUM
RANGE GUIDANCE ARE THEN IN DECENT AGREEMENT IN BRINGING A SHORT WAVE
THROUGH THE RIDGE AND ACROSS THE MIDWEST THURSDAY...WITH RETURN FLOW
AND THE NEXT CHANCE OF SHOWER/THUNDERSTORMS DEVELOPING IN ADVANCE AS
THE SURFACE HIGH MOVES OFF TO THE EAST.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NE WINDS ARND 15 KT WITH OCNL GUSTS TO 20 KT EXPECTED FOR THE
NEXT HOUR OR SO. WINDS THEN SLOWLY VEER BACK TO SW THROUGH THE
EARLY AFTN.
* GUSTY SW WINDS WITH GUSTS ARND 20 KT THIS AFTN.
* TSRA EXPECTED THIS AFTN AND EVENING WITH SHRA OVERNIGHT INTO
SUNDAY MORNING. STRONG TO SEVERE STORMS ARE PROBABLE THIS AFTN.
JEE
//DISCUSSION...UPDATED 16Z...
THE GUST FRONT IS STILL GOING STRONG AND WE ARE NOW FOCUSING ON TS
DEVELOPMENT ALONG IT AND OTHER BOUNDARIES ACROSS THE REGION THIS
AFTN. THINKING THE NE WINDS BEHIND THE GUST FRONT WILL SLOWLY VEER
BACK TO SW INTO THIS AFTN. AT THE SAME TIME INSTABILITY IS
INCREASING ACROSS THE REGION AND EXPECTING STORMS TO FIRE ALONG
THE AFOREMENTIONED BOUNDARIES. EXACT TIMING...LOCATION...AND
TS COVERAGE ARE STILL VERY FUZZY BECAUSE NO PIECE OF GUIDANCE IS
ACCURATELY PORTRAYING WHAT IS HAPPENING NOW. STRONG TO SEVERE
STORMS ARE PROBABLE THIS AFTN.
PREVIOUS DISCUSSION...12Z...
A MESSY FORECAST SITUATION TODAY WITH LOTS OF POTENTIAL PITFALLS.
THE GENERAL PATTERN OF SSWLY-SWLY FLOW IN A VERY WARM/MOIST/
UNSTABLE AIRMASS. DEEPER LAYER MIXING TODAY SHOULD ALLOW STRONG
WINDS TO REACH THE SFC...WITH PREVAILING GUSTS OF 15-20KT.
HOWEVER...IT IS THE FINER SCALE DETAILS THAT HAVE THE POTENTIAL TO
BRING QUICK CHANGES. TWO WELL DEFINED OUTFLOW BOUNDARIES ARE
APPROACHING THE REGION...ONE MOVING EWD THROUGH ERN IOWA AND
ANOTHER DROPPING SEWD THROUGH SRN WISCONSIN. THE OUTFLOW BOUNDARY
DROPPING OUT OF WISCONSIN WILL BE THE INITIAL CONCERN. TIMING THE
BOUNDARY FROM THE LATEST RADAR IMAGERY SUGGESTS THAT IT COULD MOVE
THROUGH RFD AT ARND 13Z AND THR CHICAGO AREA ARND 14Z...SHOULD IT
HOLD TOGETHER. GIVEN THAT UNCERTAINTY...HAVE NOT TRIED TO TIME IT
IN THE LATEST TAF ISSUANCE...BUT THERE IS THE POTENTIAL FOR AN
ABRUPT WIND SHIFT TO NWLY WITH GUSTS TO 30KT.
THERE ALSO CONTINUES TO BE OCNL SCT SHRA/TSRA DEVELOPMENT IN THE
WARM ADVECTION ZONE AHEAD OF THE APPROACHING COLD FRONT. THERE
WILL BE THE POTENTIAL FOR ISOLD ACTIVITY THROUGH THE DAY TODAY
GIVEN THE UNSTABLE ENVIRONMENT. THE ADDITION OF MULTIPLE OUTFLOW
BOUNDARIES LEFT FROM YESTERDAYS ACTIVITY OVER THE REGION AS WELL
AS NEW BOUNDARIES MOVING INTO THE REGION WILL KEEP THE POTENTIAL
FOR ADDITIONAL TSRA TODAY...THOUGH CONFIDENCE IN TIMING...COVERAGE
AND LOCATION IS HIGHLY UNCERTAIN AND MUCH TOO LOW TO TRY AND PIN
DOWN IN THE TAFS AT THIS TIME.
THERE IS A LITTLE BETTER CONFIDENCE IN MORE WIDESPREAD...ORGANIZED
SHRA AND TSRA TONIGHT THIS EVENING AND TONIGHT WITH THE FRONTAL
PASSAGE. WHILE THERE IS STILL SOME TIMING DIFFERENCES AMONG THE
MODEL GUIDANCE AS TO THE EXACT TIMING OF THE FRONT...THE MOST
FAVORABLE TIME FOR MORE ORGANIZED ACTIVITY WILL BE THROUGH THE
EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-LOW CONFIDENCE IN HOW LONG NE GUSTS WILL LAST AND HOW
LONG IT WILL TAKE TO GET BACK TO GUSTY SW WINDS.
* MEDIUM CONFIDENCE IN TSRA TIMING...OCCURRENCE AND COVERAGE THIS
AFTN.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR. WX NIL.
MONDAY...VFR. WX NIL.
TUESDAY...SLIGHT CHANCE TSRA IN THE AFTERNOON.
WEDNESDAY...VFR. WX NIL.
THURSDAY...CHANCE TSRA.
FRIDAY...VFR/WX NIL EARLY. CHANCE TSRA OVERNIGHT.
KREIN
&&
.MARINE...
350 AM CDT
HIGH DEW POINT AIR MAY CONTINUE TO PRODUCE SOME FOG OVER THE OPEN
WATERS OF THE LAKE INTO EARLY SATURDAY MORNING. OTHERWISE...
SOUTH TO SOUTHWEST FLOW OVER THE LAKE SHOULD INCREASE TO ARND
15-25KT THIS AFTERNOON AND TONIGHT AS A COLD FRONT ASSOCIATED WITH
LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES TO HUDSON BAY.
THE FRONT SHOULD PUSH ACROSS THE LAKE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL BEING DIMINISHING WLY FLOW TO THE LAKE...BUT ANOTHER COLD
FRONT DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY MONDAY WILL
BRING ANOTHER ROUND OF INCREASING SWLY WINDS INTO MONDAY EVENING
BEFORE THE COLD FRONT PUSHES ACROSS THE LAKE LATE MONDAY NIGHT
INTO EARLY TUESDAY MORNING. A LARGE AREA OF WEAK HIGH PRESSURE IS
EXPECTED TO SPREAD ACROSS THE GREAT LAKES REGION BY TUESDAY NIGHT.
THE HIGH PRESSURE SHOULD REMAIN NEARLY STATIONARY OVER THE GREAT
LAKES REGION THROUGH MUCH OF NEXT WEEK...BRINGING AN EXTENDED
PERIOD OF LIGHT AND VARIABLE WINDS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM SATURDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
SATURDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
413 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 141 PM EDT SAT JUL 18 2015
HOT AND HUMID CONDITIONS WILL CONTINUE ACROSS THE REGION.
TEMPERATURES WILL WARM INTO THE 80S TO MIDDLE 90S THIS AFTERNOON.
HEAT INDEX VALUES FROM 100 TO 110 ARE POSSIBLE THIS AFTERNOON.
THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORM THIS AFTERNOON
THROUGH TONIGHT AND AGAIN ON SUNDAY. IT WILL REMAIN WARM AND MUGGY
TONIGHT WITH LOWS ONLY DROPPING INTO THE 70S OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 412 PM EDT SAT JUL 18 2015
MORNING/EARLY AFTERNOON MCS IS CURRENTLY PUSHING OUT OF LOCAL
FORECAST AREA TO THE EAST. THIS HAS PRODUCED A NOTICABLE OUTFLOW
BOUNDARY CURRENTLY EXTENDING FROM MICHIGAN CITY SE TO PORTLAND.
HAVE REMOVED MANY OF THE COUNTIES NORTH OF THIS OUTFLOW FROM THE
HEAT ADVISORY...ESPECIALLY EAST OF A WARSAW TO THREE RIVERS LINE.
WHILE TEMPERATURES MAY RECOVER INTO THE MID 80S...HEAT INDICES
SHOULD REMAIN BELOW CRITERIA. ELSEWHERE...TEMPERATURES WILL HOVER
AROUND 90 WITH HEAT INDICES AROUND 100...SO THE HEAT ADVISORY WILL
CONTINUE INTO THE EVENING.
CURRENTLY MONITORING UPSTREAM CONVECTIVE TRENDS ACROSS NRN IL. HI
RES GUIDANCE HAS BEEN LITTLE HELP TODAY REGARDING CONVECTIVE
TRENDS...HOWEVER LATEST RADAR DATA SHOWS ORGANIZATION ACROSS FAR NW
IL/SRN WI. HRRR SUGGEST CONTINUED WARM SECTOR STORM DEVELOPMENT
FURTHER SOUTH FROM EAST CENTRAL IL INTO WESTERN IN. THESE STORMS MAY
POSE AN ISOLATED SEVERE WEATHER THREAT...WITH DAMAGING WINDS AND
HEAVY RAINFALL THE MAIN THREAT. FURTHER INTEREST LIES WITH THE
ORGANIZATION ACROSS NRN IL. ANTICIPATE THAT THIS FEATURE MAY
PROPAGATE E/SE TOWARDS THE AREA BETWEEN 22Z AND 01Z...RIDING ALONG
THE APPRECIABLE INSTABILITY GRADIENT DEMARCATED BY THE
AFOREMENTIONED OUTFLOW BOUNDARY. SBCAPE VALUES BUILDING TO 4000
TO 6000 J/KG SOUTH OF THIS OUTFLOW W/ MID LVL LAPSE RATES NEAR 6.5
C/KM. EFFECTIVE SHEAR VALUES ARE MARGINAL...FROM 20-30 KTS ACROSS
THE AREA...HOWEVER IF THIS LINE CAN ORGANIZE...WHICH IT APPEARS TO
BE DOING AS I WRITE THIS...SHOULD BE SUFFICIENT TO MAINTAIN INTO
THE NORTHWEST PART OF THE AREA AROUND 00Z AS A SQUALL LINE/BOW
ECHO. THIS WOULD PRODUCE A BETTER THREAT FOR DAMAGING
WINDS...POTENTIALLY SIGNIFICANT...ROUGHLY ALONG THE OUTFLOW
BOUNDARY FROM MICHIGAN CITY TO JUST SOUTH OF FORT WAYNE. OF
COURSE...WITH THIS OUTFLOW BOUNDARY SITUATED ACROSS THE AREA...ANY
STORMS THAT PROPAGATE ALONG IT WILL MAINTAIN A HIGHER TORNADO RISK
W/ ENHANCED LOW LVL SHEAR. HAVE REFLECTED THIS IN THE GRIDS WITH A
DAMAGING WIND MENTION...FROM NW TO SE ACROSS THE FORECAST AREA
FROM 22Z TO 03Z. WILL BE MONITORING THIS CLOSELY OVER THE NEXT
SEVERAL HOURS.
FORECAST PICTURE BECOMES SOMEWHAT MUDDLED AFTER 06Z...AND WILL HINGE
ON CONVECTIVE EVOLUTION BETWEEN NOW AND THEN. LARGER SCALE FRONT
WILL PUSH SE INTO THE AREA BY TOMORROW MORNING. HAVE BACKED OFF POPS
A BIT...ESPECIALLY NW...LATE TONIGHT THROUGH SUNDAY. HIGHEST POPS
ARE CURRENTLY SUNDAY AFTN AS THE FRONT IS LAYED OUT FROM SW TO NE
ACROSS THE FCST AREA. HIGH TEMPS SUNDAY WERE CUT JUST A BIT AS
WELL...MAINLY ACROSS THE NW PORTION OF THE FORECAST AREA. THERE MAY
BE A FEW LOCATIONS THAT HAVE HEAT INDICES APPROACH 100
TOMORROW...MAINLY SOUTH AND EAST OF FORT WAYNE. HOWEVER...WITH
UNCERTAINTY IN THE PRECIP EVOLUTION AND TEMPS...WILL HOLD OFF ON ANY
HEAT HEADLINES RIGHT NOW FOR SUNDAY.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 412 PM EDT SAT JUL 18 2015
CDFNT EXPECTED TO BE MOVG THROUGH SERN PORTION OF CWA SUNDAY
EVE WITH TSTMS PSBL ALONG IT IN THE EVE. SFC HIGH SHOULD BUILD
INTO THE AREA MONDAY PROVIDING FAIR WX. MID LEVEL CUT-OFF LOW OVER
IDAHO THIS AFTN IS EXPECTED TO SHEAR EASTWARD ACROSS THE MID MS/OH
VALLEY MONDAY NIGHT/TUE BRINGING A CHC OF SHOWERS TO THE AREA.
RIDGING EXPECTED TO MOVE ACROSS THE AREA WED-FRI RESULTING IN FAIR
WX WITH A SLOW WARMING TREND. RETURN FLOW BEHIND THE SFC HIGH
COMBINING WITH A WK SHRTWV TOPPING UPR RIDGE MAY BRING TSTMS BACK
INTO THE AREA ON SATURDAY. OVERALL... TEMPS EXPECTED TO BE A BIT
BLO NORMAL DURING THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 141 PM EDT SAT JUL 18 2015
HIGHLY UNCERTAIN TAF PD WITH THUNDERSTORMS NORTH OF KFWA EARLY
THIS AFTERNOON. EXPECT OUTFLOW BOUNDARY NOTED ON RADAR TO SHIFT
SOUTH THROUGH KFWA OVER THE FIRST COUPLE HOURS OF THE TAF
PD...WITH WINDS SHIFTING FROM THE NORTH AND BRIEF MVFR CIGS. NO
TSRA MENTION AT THIS TIME GIVEN UNCERTAINTY WITH TRACK OF CURRENT
STORMS...HOWEVER WILL MONITOR CLOSELY THROUGH 21Z AND AMEND KFWA
IF NEEDED.
ADDITIONAL THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON INTO EVENING
AS AFOREMENTIONED OUTFLOW BOUNDARY REMAINS INVOF KSBN AND KFWA.
RIGHT NOW...HANDLED TAF FCST WITH VCTS MENTION...SIMILAR TO
YESTERDAY`S SETUP. WILL MONITOR THROUGH THE EVENING AND AMEND IF
TSRA ACTIVITY MATERIALIZES AND IS EXPECTED TO IMPACT TERMINALS.
OTHERWISE...VFR CONDS GENERALLY EXPECTED AFTER 02Z...WITH TSRA
CHANCES CONTINUING LATE IN THE FCST PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
INZ003>005-012>016-020-022>027-032>034.
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ077-078.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY/NG
SHORT TERM...NG
LONG TERM...JT
AVIATION...NG
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
149 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISSUED AT 141 PM EDT SAT JUL 18 2015
HOT AND HUMID CONDITIONS WILL CONTINUE ACROSS THE REGION.
TEMPERATURES WILL WARM INTO THE 80S TO MIDDLE 90S THIS AFTERNOON.
HEAT INDEX VALUES FROM 100 TO 110 ARE POSSIBLE THIS AFTERNOON.
THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORM THIS AFTERNOON
THROUGH TONIGHT AND AGAIN ON SUNDAY. IT WILL REMAIN WARM AND MUGGY
TONIGHT WITH LOWS ONLY DROPPING INTO THE 70S OVERNIGHT.
&&
.UPDATE...
ISSUED AT 1013 AM EDT SAT JUL 18 2015
MAIN ADJUSTMENT W/ THIS FCST UPDATE IS TO INCREASE POPS ACROSS SRN
LWR MI AND FAR NE IN/NW OH THROUGH EARLY AFTN...AS WEAKENING MCS
DROPS SOUTHEAST FROM LK MI THIS MORNING. HI-RES MODEL GUIDANCES
DOING A VERY POOR JOB HANDLING THE EVOLUTION OF THIS
LINE...HOWEVER RADAR TRENDS SUGGEST IT WILL HOLD TOGETHER IN SOME
FORM INTO THE NORTHERN PART OF THE FCST AREA. SEVERE THREAT LOOKS
LOW AT THIS POINT...WITH RECENT UPSTREAM OBS SUGGESTING WIND
GUSTS AROUND 30 TO 40 MPH OVER THE LAST HOUR OR SO.
BIGGER CHALLENGE WILL BE THE IMPACT OF THIS LINE OF STORMS AND ITS
ATTENDANT OUTFLOW ON AFTN POPS...AS AIRMASS ACROSS NRN IN BECOMES
INCREASINGLY UNSTABLE INTO THE AFTN. FOR NOW...CONTINUED WITH
ISO/SLIGHT CHANCE MENTION THROUGH THE AFTN...WITH A SLIGHTLY
HIGHER POP NOTED ALONG/NORTH OF US 6...WHERE OUTFLOW IS EXPECTED
TO ANCHOR. ANOTHER CHALLENGE THE IMPACT OF THESE STORMS ON AFTN HI
TEMPS/HEAT INDICES. FOR NOW...MADE NO MAJOR CHANGES TO
TEMPS...ALTHOUGH DIURNAL HEATING WILL BE SLOWED/DELAYED WITH THIS
PRECIP AND CLOUD COVER...ESPECIALLY NORTH OF US 6. WILL CONTINUE
TO MONITOR TEMPERATURE AND CONVECTIVE TRENDS THROUGH THE MORNING
AND MAKE ADJUSTMENTS TO THE FCST THROUGHOUT THE DAY AS NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT JUL 18 2015
HEAT AND HUMIDITY ARE FIRST ISSUES TO DEAL WITH IN THE
SHORT TERM PERIOD FOLLOWED BY TSRA CHANCES THIS AFTERNOON AND
TONIGHT. SEVERAL AREAS OF UPSTREAM CONVECTION WILL BE PROBLEMATIC
FOR OUR AREA BOTH IN TERMS OF CLOUD COVER AND ANY CONVECTIVELY
ENHANCED SHORT WAVES THAT PROPAGATE EAST LATER TODAY AND TONIGHT.
PERSISTENT AREA OF TSRA HAS BEEN ONGOING MOST OF THE NIGHT IN THE
CHICAGO AREA AND THIS HAS KEPT ANVIL CLOUDS OVER NORTHERN INDIANA
AND NORTHWEST OHIO. EXPECT THIS CONVECTION TO DIMINISH TOWARD
SUNRISE AND CLOUD COVER TO THIN BUT SATELLITE SHOWING CIRRUS FROM
MN/IA CONVECTION PROGRESSING TOWARD THE AREA. SHOULD SEE THIS THIN
AS WELL BUT THIN VEIL OF CLOUDS TO LIKELY PERSIST TODAY AND INHIBIT
TEMP RISE BY A COUPLE DEGREES. STILL SHOULD SEE HIGHS REACH LOWER
90S MOST AREAS WITH MID 90S POSSIBLE IF CIRRUS REMAINS THIN THROUGH
THE DAY. DEW POINTS STILL EXPECTED TO RISE WELL INTO THE MIDDLE AND
UPPER 70S BUT MIX A BIT IN AFTERNOON BACK TO LOWER 70S. NO REAL
CHANGE TO GOING HEAT ADVISORY AS APPARENT TEMPS WILL STILL BE
BETWEEN 100 AND 105 WITH SOME AREAS REACHING 110.
THE HEAT AND HUMIDITY WILL HELP PUSH MUCAPES TO BETWEEN 4000-5000
J/KG THIS AFTERNOON. DEEP LAYER SHEAR REMAINS WEAK UNTIL LATER
TONIGHT WHEN WESTERLIES SINK CLOSER TO THE AREA. HOWEVER...LARGE
AMOUNT OF INSTABILITY AND WEAK CAP MAY ALLOW AN ISOLATED TSRA TO
DEVELOP DURING PEAK HEATING. OTHER ISSUE WILL BE EVOLUTION AND
PROPAGATION OF UPSTREAM MESOSCALE CONVECTIVE SYSTEMS. NMM AND ARW
WANT TO BRING SOME CONVECTION INTO NORTHERN AREAS THIS AFTERNOON.
LATEST RUNS OF HRRR AND RAP HAVE BEEN INCONSISTENT FROM RUN TO RUN.
LATEST HRRR BRINGS A LINE OF CONVECTION INTO THE NORTH EARLY THIS
EVENING. WILL CONTINUE WITH SLIGHT CHANCE POPS THIS AFTERNOON FOR
ANY PULSE STORMS THAT CAN BREAK CAP WITH HELP OF ANY WEAK SHORT
WAVES. RAISED POPS TO CHANCE CATEGORY THIS EVENING AND OVERNIGHT FOR
POSSIBLE MCS DEVELOPMENT.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT JUL 18 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING AND COVERAGE OF
STORMS AND THE CHANCE FOR ANOTHER DAY OF EXCESSIVE HEAT ON SUNDAY.
A COLD FRONT ASSOCIATED WITH A POSITIVELY TILTED UPPER TROF WILL
MOVE EAST TOWARD THE UPPER GREAT LAKES REGION. THERE IS MUCH
UNCERTAINTY CONCERNING THE LOCATION OF ONGOING CONVECTION AND
EARLIER STORM OUTFLOW BOUNDARIES THAT MAY ACCENTUATE THE
FRONT...OR CAUSE ANY THERMAL GRADIENT TO BECOME MORE DIFFUSE. HAVE
MAINTAINED LIKELY CHANCES FOR STORMS SUNDAY...WITH THE MENTION OF
THE CHANCE FOR HEAVY RAIN GIVEN THE APPROACH OF THE FRONT DURING
THE TIME OF PEAK HEATING DURING THE DAY. FOR NOW...HAVE HEAT
INDICES RISING INTO THE 90S...BUT STAYING JUST SHY OF THE CRITERIA
FOR A HEAT ADVISORY. GIVEN THESE PARAMETERS WITH THE INCREASE OF
MID LEVEL WINDS...THERE IS THE CHANCE SOME STORMS COULD BECOME
SEVERE. OTHERWISE...THE UPPER LEVEL RIDGE OVER THE SOUTH WILL
BUILD WEST...WITH PLENTY OF ENERGY TOPPING THE RIDGE OVER OUR
AREA. IN THIS REGARD...KEPT THE MENTION OF A CHANCE FOR STORMS
THURSDAY AND THURSDAY NIGHT. TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 141 PM EDT SAT JUL 18 2015
HIGHLY UNCERTAIN TAF PD WITH THUNDERSTORMS NORTH OF KFWA EARLY
THIS AFTERNOON. EXPECT OUTFLOW BOUNDARY NOTED ON RADAR TO SHIFT
SOUTH THROUGH KFWA OVER THE FIRST COUPLE HOURS OF THE TAF
PD...WITH WINDS SHIFTING FROM THE NORTH AND BRIEF MVFR CIGS. NO
TSRA MENTION AT THIS TIME GIVEN UNCERTAINTY WITH TRACK OF CURRENT
STORMS...HOWEVER WILL MONITOR CLOSELY THROUGH 21Z AND AMEND KFWA
IF NEEDED.
ADDITIONAL THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON INTO EVENING
AS AFOREMENTIONED OUTFLOW BOUNDARY REMAINS INVOF KSBN AND KFWA.
RIGHT NOW...HANDLED TAF FCST WITH VCTS MENTION...SIMILAR TO
YESTERDAY`S SETUP. WILL MONITOR THROUGH THE EVENING AND AMEND IF
TSRA ACTIVITY MATERIALIZES AND IS EXPECTED TO IMPACT TERMINALS.
OTHERWISE...VFR CONDS GENERALLY EXPECTED AFTER 02Z...WITH TSRA
CHANCES CONTINUING LATE IN THE FCST PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...HEAT ADVISORY UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
INZ003>009-012>018-020-022>027-032>034.
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ077>081.
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ001-002-004-005-
015-016-024-025.
LM...NONE.
&&
$$
UPDATE...NG
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...NG
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
146 PM EDT SAT JUL 18 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 344 AM EDT SAT JUL 18 2015
A STRONG UPPER LEVEL RIDGE NOSING INTO THE AREA WILL MAKE FOR THE
HOTTEST DAY OF THE YEAR THUS FAR ACROSS CENTRAL INDIANA...WITH
HIGH TEMPERATURES IN THE LOW TO MID 90S AND HEAT INDEX VALUES IN
THE MID 100S. THE VERY HOT AND HUMID AIRMASS MAY ALLOW FOR
THUNDERSTORM DEVELOPMENT IN THE HEAT OF THE DAY ALONG REMNANT
BOUNDARIES FROM PRIOR CONVECTION. A MORE ORGANIZED FRONTAL SYSTEM
WILL APPROACH FROM THE NORTHWEST LATE TONIGHT AND DROP THROUGH THE
AREA SUNDAY INTO SUNDAY NIGHT...WITH STORMS LIKELY. THIS FRONTAL
BOUNDARY WILL BRING TEMPERATURES CLOSER TO NORMAL NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1014 AM EDT SAT JUL 18 2015
.UPDATE...DROPPED TEMPERATURES SLIGHTLY SOME AREAS BASED ON CURRENT
TEMPERATURES AND WET GROUND. HOWEVER LOWER 90S WITH HEAT INDEX VALUES
FROM 101 TO 107 STILL LOOK GOOD. RAP SOUNDINGS LOOK MOSTLY CAPPED...
BUT I WOULD NOT RULE OUT AN ISOLATED THUNDERSTORM. NO OTHER UPDATES
ARE NEEDED AT THIS TIME.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HEIGHTS RISE ACROSS THE AREA TODAY AS THE RIDGE STRENGTHENS TO OUR
SOUTH...BUT WITH RESIDUAL BOUNDARIES FROM PRIOR CONVECTION AND A
VERY HOT AND HUMID AIRMASS IN PLACE...WITH DEWPOINTS WELL INTO THE
70S...WILL HAVE TO CARRY AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON AND EVENING. OTHERWISE HEAT IS THE SIGNIFICANT
FORECAST VARIABLE.
CONSENSUS NUMBERS HAVE BEEN RUNNING COOL LATELY AND THIS LOOKS TO
BE THE CASE AGAIN. HAVE BUMPED THEM UP AT LEAST A COUPLE OF
DEGREES...AND EXPECT HIGHS TO REACH THE LOW TO MID 90S ACROSS THE
AREA. COUPLED WITH THE EXTREMELY HIGH DEWPOINTS...HEAT INDEX
VALUES WILL LIKELY REACH THE MID 100S. THIS IS COVERED WELL BY
PREVIOUSLY ISSUED HEAT ADVISORY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 344 AM EDT SAT JUL 18 2015
STORMS FROM PEAK HEATING MAY LINGER INTO THE EVENING...AND THEN
ACROSS THE NORTH WILL REQUIRE POPS LATE TONIGHT AS THE FRONT
BEGINS TO APPROACH THE AREA. LIKELY POPS WILL BE REQUIRED SUNDAY
INTO SUNDAY NIGHT AS THIS BOUNDARY DROPS THROUGH THE AREA. AREA IS
OUTLOOKED DAY 2 AND THIS APPEARS REASONABLE. CHANCE POPS WILL BE
REQUIRED ACROSS THE SOUTH ON MONDAY NEARER THE LINGERING FRONTAL
BOUNDARY...AND THEN ACROSS THE ENTIRE AREA MONDAY NIGHT AS AN
UPPER LEVEL WAVE APPROACHES AND THE BOUNDARY BEGINS TO SHIFT BACK
NORTH.
CONSENSUS NUMBERS CONTINUE TO RUN COOL ON MAX TEMPS AND HAVE
ADJUSTED ACCORDINGLY. MIN TEMPS APPEAR MORE REASONABLE.
TEMPERATURES WILL BEGIN A GRADUAL RETURN TO MORE NORMAL NUMBERS
TOWARD THE END OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 334 AM EDT SAT JUL 18 2015
UPPER RIDGE WILL RECENTER OVER THE HIGH PLAINS EARLY IN THE PERIOD
BEFORE SHIFTING BACK EAST AND EXPANDING INTO THE MISSISSIPPI
VALLEY BY NEXT WEEKEND AS AN UPPER LOW SHIFTS EAST INTO THE
CANADIAN MARITIMES. THIS WILL KEEP THE REGION ON THE RIDGE
PERIPHERY WITHIN A NORTHWEST FLOW PATTERN WITH AT LEAST A FEW
OPPORTUNITIES FOR STORMS.
GOOD CHANCE FOR SCATTERED STORMS TUESDAY WITH THE FRONTAL
BOUNDARY DROPPING SOUTH THROUGH THE OHIO VALLEY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT AND SHOULD PROVIDE AT LEAST A BRIEF
BREAK FROM THE STORMY WEATHER MIDWEEK. CONVECTIVE CHANCES WILL
RETURN THURSDAY AND FRIDAY AS A WARM FRONT APPROACHES FROM THE
WEST. APPEARS NOW THE POTENTIAL FOR HOTTER TEMPERATURES WILL HOLD
OFF UNTIL THE WEEKEND...WITH HIGHS PRIMARILY IN THE 80S THROUGH
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 181800Z TAF ISSUANCE/...
ISSUED AT 131 PM EDT SAT JUL 18 2015
VFR CONDITIONS ANTICIPATED FOR MUCH OF THE FORECAST PERIOD.
HOWEVER MVFR VISIBILITIES ARE POSSIBLE LATE TONIGHT AT THE
OUTLYING TAF SITES AND LOWER FLIGHT CATEGORIES ARE ALSO POSSIBLE
IF ANY SHOWERS DEVELOP OVER THE AREA.
THE NEXT 24 HOURS IS VERY HARD TO FORECAST FOR SO FORECASTER
CONFIDENCE IS VERY LOW AS MODELS ARE ALL IN DISAGREEMENT IN SOME
FORM...MEANWHILE THE ENVIRONMENT MAY BECOME CONDITIONALLY UNSTABLE
ENOUGH TO NOT ONLY SUPPORT SHOWERS...BUT THUNDERSTORMS/CONVECTION
AS WELL EARLY THIS EVENING. FOR NOW WENT WITH SCATTERED SHOWERS
BEGINNING AROUND 21Z FOR THE WESTERN MOST SITES AND LEFT THIS IN
THROUGH EARLY THIS EVENING...THEN WENT DRY FOR THE OVERNIGHT.
SOME OF THE OUTLYING SITES WHICH ARE VERY MOISTURE LADEN AND COULD
SEE SOME CLEARING OF SKIES AND LIGHT TO CALM WINDS MAY HAVE SOME
MVFR BR EARLY SUNDAY MORNING. THEN BETTER CHANCE FOR SHOWERS AND
STORMS COMES LATER ON SUNDAY...WHICH WAS INDICATED WITH -SHRA AND
VCTS AT THIS TIME...SINCE PROJECTING WHEN AND WHERE A THUNDERSTORM
WILL OCCUR THIS FAR OUT IN TIME IS VERY DIFFICULT...BUT THE
POTENTIAL IS DEFINITELY THERE AND CONFIDENCE IS MUCH HIGHER FOR
PRECIP AND STORM CHANCES WITH A FRONTAL PASSAGE ON SUNDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JH
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS DES MOINES IA
331 PM CDT SAT JUL 18 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 328 PM CDT SAT JUL 18 2015
PRIMARY CONCERN WILL OBVIOUSLY REMAIN CONVECTIVE TRENDS INTO THE
NIGHT. IA CONTINUES TO BE INFLUENCED BY MODERATE WESTERLIES
UNDER MANITOBA SHORT WAVE TROUGH. STREAM OF WEAK SHORT WAVES
CONTINUES TO RIDE THIS FLOW FROM CO INTO IA WITH ONLY WEAK FORCING
NOTED IN OBJECTIVE RAP ANALYSIS AND SUBJECTIVE GLANCE AT WATER
VAPOR IMAGERY. 19Z SURFACE ANALYSIS SHOWS TWO AREAS OF GENESIS
CONCERN...ONE ALONG TRUE COLD FRONT MOVING THROUGH SIOUXLAND AREA
AND SECOND WITH TROUGH SW-NE THROUGH THE HEART OF IA. FORMER
AIRMASS IS UNCAPPED WITH CU DEVELOPMENT STARTING WITH SHOWERS OVER
SWRN MN...BUT RELATIVELY WEAK INSTABILITY...1000 J/G. THE LATTER
AIRMASS IS MORE UNSTABLE...2-3K J/KG...BUT STILL CAPPED WITH NON-
DESCRIPT CONVERGENCE. SOME CU HAS BEEN TRYING TO FORM IN THIS AREA
BUT LOOKS UNORGANIZED. FOR SENSIBLE WEATHER THIS MEANS PULLING LOW
END POPS INTO NWRN IA FOR A BIT...AND KEEPING PREVIOUSLY LOWERED
CHANCE POPS SE. MOST MODEL GUIDANCE SUGGESTS OUR BEST POTENTIAL
MAY BE FAR SOUTH LATER INTO THE NIGHT AS NOCTURNAL WARM ADVECTION
MATURES. RELATIVELY HIGHER EFFECTIVE SHEAR CONTINUES TO OVERSPREAD
IA...SO ANYTHING THE DOES GO COULD BECOME SEVERE WITH LARGE HAIL
AND DAMAGING WINDS THE HIGHEST THREATS WITH WEAK LOW LEVEL
KINEMATICS.
REGARDING THE PRESENT HEAT ADVISORY...WILL CANCEL SHORTLY AS 20Z
HEAT INDICES ARE NOT EVEN WITHIN 10 DEGREES OF CRITERIA WITH TEMPS
STRUGGLING TO TOP 90. A FEW SPOTS MAY JUST TOP 100F HI...BUT
THIS WOULD NOT SEEM TO JUSTIFY CURRENT WIDESPREAD HEADLINE.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 328 PM CDT SAT JUL 18 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SEVERE WEATHER POTENTIAL
LATE SUNDAY NIGHT INTO MONDAY AND TEMPERATURES THROUGH THE REST OF
THE WEEK. MODELS ARE IN DISARRAY WITH TIMING AND LOCATION OF THE
CONVECTION SUNDAY NIGHT THROUGH MONDAY AND LEANED TOWARD A BLEND
OF THE ECMWF/GFS/NAM.
SUNDAY INTO MONDAY...LARGE UPPER LEVEL RIDGE HOLDING IN PLACE OVER
THE LOWER MISSISSIPPI RIVER VALLEY AND SOUTHERN PLAINS WITH AN
UPPER LOW SLOWLY MOVING OVER ONTARIO SUNDAY AND MONDAY. THIS
PLACES IOWA GENERALLY IN ZONAL FLOW ALOFT WITH A SHORTWAVE TO CUT
ACROSS THE STATE EARLY MONDAY AHEAD OF A COLD FRONT TO PUSH
THROUGH LATER IN THE DAY. NAM AND ECMWF ARE FURTHER SOUTH WITH THE
SHORTWAVE THAN THE GFS AND THUS THE BULLSEYE OF QPF IS IN NORTHERN
MISSOURI. COLD FRONT LOOKS TO PUSH ACROSS THE STATE AND CLEAR THE
FORECAST AREA BY 00Z TUESDAY AT THE LATEST. NOT CONFIDENT THE
ATMOSPHERE WILL HAVE TIME TO DESTABILIZE AHEAD OF THE COLD FRONT
ONCE THE MORNING CONVECTION HAS CLEARED TO THE EAST MONDAY.
THINKING TIMING DIFFERENCE OF SHORTWAVE AND COLD FROPA ARE
MINIMAL...THUS ANY SEVERE WEATHER POTENTIAL MORE LIKELY WITH THE
SHORTWAVE. SHEAR IS UNIDIRECTIONAL AND INSTABILITY REMAINS LIMITED
EVEN AHEAD OF THE SHORTWAVE...SO ANY THREAT SEVERE THREAT WOULD BE
DAMAGING WINDS.
TUESDAY THROUGH FRIDAY...SURFACE HIGH PRESSURE AND LARGE UPPER
LEVEL RIDGE BUILD INTO THE STATE AND DOMINATE THROUGH MUCH OF
THE WORK WEEK. TRENDED TOWARD A DRIER FORECAST WITH THE ONLY
SIGNIFICANT CHANCE OF RAIN WEDNESDAY NIGHT INTO THURSDAY. WEAK
SHORTWAVE RIDES THE UPPER RIDGE BUT LOOKS TO DISSIPATE AS IT MOVES
EAST INTO IOWA THURSDAY. TRENDED DRIER THURSDAY OVER MUCH OF THE
AREA. TEMPERATURES REMAIN FAIRLY COOL THROUGHOUT THE WEEK WITH THE
COOLEST NIGHT ANTICIPATED ON TUESDAY NIGHT. LOWERED MINIMUM
TEMPERATURES DURING THIS TIME WITH DECENT RADIATIONAL COOLING
SETTING UP.
&&
.AVIATION...18/18Z
ISSUED AT 1256 PM CDT SAT JUL 18 2015
VFR THROUGH THE PERIOD UNTIL CONVECTIVE TRENDS BECOME MORE
CLEAR. STILL ANTICIPATING SOME SCATTERED STORMS WILL DEVELOP
DURING THE LATE AFTERNOON OR EVENING HOURS SOUTH AND EAST
SECTIONS...BUT CONFIDENCE IS LOW SO NO CHANGES BEYOND VFR VCTS
WORDING FOR NOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...PODRAZIK
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1258 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1256 PM CDT SAT JUL 18 2015
OBJECTIVE ANALYSIS AT 1730Z WOULD SUGGEST FAVORABLE CONVERGENCE
AND UNCAPPED INSTABILITY IS HAVING DIFFICULTY COMING TOGETHER AT
THE MOMENT. RECENT RAP 0-1KM MOISTURE CONVERGENCE DOES ARC
BACKWARD FROM IL/WI MAX INTO S CENTRAL IA...BUT MUCH OF THIS
STILL HAS APPRECIABLE MLCINH IN OUR FORECAST AREA THIS FAR WEST.
MLCAPES ARE UNCAPPED FROM IL INTO WATERLOO WITH VALUES UP TO 2000
J/KG...BUT FAIRLY UNIFORM SWLY WINDS RESULT IN LITTLE CONVERGENCE
INTO NERN SECTIONS. FORECAST SOUNDINGS AND HI RES CONVECTION
ALLOWING MODELS ALL SUGGEST ANY GENESIS IN CENTRAL IA MAY TAKE
AWHILE DUE TO CAP. 17Z SUBJECTIVE SURFACE ANALYSIS SHOWS TRUE COLD
FRONT STILL UPSTREAM NW OF THE SIOUXLAND AREA WITH MORE OF A
PRESSURE TROUGH AND WEAK CONVERGENCE FROM KS INTO IA. THUS EARLY
AFTERNOON UPDATE WILL LIKELY PUSH BACK TIMING ON CONVECTIVE
INITIATION.
&&
.SHORT TERM /TODAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONVECTIVE TRENDS THROUGHOUT THE DAY WILL BE THE PRIMARY FORECAST
CHALLENGE ALONG WITH THE SUBSEQUENT TRICKLE DOWN EFFECT TO THE
REMAINDER FORECAST ELEMENTS. OVERNIGHT THUNDERSTORMS FROM NORTHERN
IOWA AND INTO SOUTHERN MINNESOTA HAVE PUSHED AN OUTFLOW BOUNDARY
THROUGH THE NORTHWEST HALF OF THE STATE AND HAS BROUGHT A SWITCH TO
NORTHWEST WINDS AND HAS DROPPED DEWPOINTS INTO THE LOW TO MID 60S.
VERY GUSTY WINDS HAVE MAINTAINED OVER FAR NORTHWEST IOWA THE PAST
SEVERAL HOURS...ESPECIALLY AROUND THE STORM LAKE AREA WHERE GUSTS
HAVE BEEN AROUND 50 MPH. THE LATEST OB FROM STORM LAKE WITH A WIND
GUST TO 74 MPH SEEMS RELATED TO A HEAT BURST AS THE TEMPERATURE
JUMPED 15 DEGREES WHILE DEWPOINTS DROPPED TO 52. WILL NEED TO
MONITOR TO SEE IF THIS PHENOMENON BECOMES MORE WIDESPREAD.
CONVECTIVE TRENDS THROUGH THE MID MORNING HOURS SHOULD GRADUALLY
DIMINISH EXCEPT FOR POSSIBLE STORMS OVER FAR SOUTHWEST IOWA.
CONVECTIVE DEBRIS WILL BE AROUND FOR AT LEAST A PORTION THIS MORNING
AND WILL HELP SLOW TEMPERATURES OVER AT LEAST CENTRAL AND NORTHERN
IOWA. DEWPOINTS SHOULD RECOVER BY LATE MORNING AND INTO THE
AFTERNOON WITH SOME POOLING OCCURRING ALONG AND AHEAD OF A BOUNDARY
MOVING INTO NORTHWEST IOWA THIS AFTERNOON. POSSIBLE DEWPOINTS COULD
JUMP INTO THE UPPER 70S ALONG THE BOUNDARY. THE BEST CHANCE FOR
THUNDERSTORMS WILL BE ALONG THE BOUNDARY BY THIS AFTERNOON AS IT
SINKS INTO CENTRAL IOWA.
WILL BE ISSUING A HEAT ADVISORY AGAIN FOR THE SOUTHERN THREE TIER OF
COUNTIES WHERE HEAT INDEX VALUES SHOULD AGAIN BE NEAR 105. CURRENT
FORECAST FOR DSM WOULD PLACE THE METRO IN A 3RD STRAIGHT WITH MOIST
TROPICAL PLUS AIR MASS. THE MAIN UNCERTAINTY FOR INTERSTATE 80 AND
NORTH IS CLOUD COVER THROUGH THE DAY WHICH VERY WELL COULD KEEP
TEMPERATURES COOLER THAN FRIDAY THOUGH DEWPOINTS WILL BE SIMILAR.
.LONG TERM /TONIGHT THROUGH FRIDAY/...
ISSUED AT 355 AM CDT SAT JUL 18 2015
CONCERN FOR BEGINNING OF PERIOD WILL BE WITH PRECIPITATION CHANCES
AND THREAT FOR SEVERE WEATHER TONIGHT. MODELS...INCLUDING HIGH
RES...CONTINUE TO HOLD OFF ON PRECIPITATION DEVELOPMENT UNTIL
CLOSER TO 06Z...EXPECTING CAP TO REMAIN IN PLACE THROUGH AFTERNOON
AND EARLY EVENING BEFORE LLJ BEINGS TO INFLUENCE THE AREA.
HOWEVER...HAVE KEPT POPS IN THROUGH THE BEGINNING OF
PERIOD...EXPECTING ONGOING PRECIPITATION ACROSS THE AREA. BEST
CHANCES THROUGHOUT THE OVERNIGHT PERIOD WILL BE FOCUSED ALONG AND
SOUTH OF BOUNDARY...EXPECTED TO BE GENERALLY ACROSS SOUTHERN
PORTIONS OF THE CWA. WILL SEE A THREAT FOR HEAVY RAINFALL AGAIN IN
THIS AREA...WITH PWAT VALUES NEAR 1.9 INCHES AND GOOD WARM CLOUD
DEPTHS. MAY SEE POTENTIAL FOR FLASH FLOODING IN THE SOUTH
OVERNIGHT...BUT WILL HOLD OFF ON HEADLINES WITH PLACEMENT OF
PRECIPITATION STILL A BIT UNCERTAIN WITH SPEED OF BOUNDARY AND
POTENTIAL FOR REMNANTS OF OVERNIGHT CONVECTION TO INFLUENCE
CONVECTION. SHEAR WILL BE SOMEWHAT LACKING...BUT EXPECT
INSTABILITY TO BE STRONG ENOUGH TO OVERCOME LACKING SHEAR...MUCH
LIKE TONIGHT...TO WARRANT CHANCES FOR SEVERE THUNDERSTORMS EARLY
IN THE PERIOD.
BOUNDARY WILL PUSH SLOWLY SOUTH WITH PRECIPITATION CHANCES
LINGERING ALONG IT THROUGH SUNDAY MORNING IN THE SOUTH.
HOWEVER...MAY HAVE HELD ONTO CHANCES TOO LONG. WILL SEE A BREAK IN
HOT AND MUGGY CONDITIONS WITH A COOLER AIR MASS WORKING
IN...THOUGH TEMPS WILL STILL BE NEAR NORMAL....IN THE 80S. WAVE
WILL PUSH EAST THROUGH MOSTLY ZONAL FLOW FOR BEGINNING OF THE
WORK WEEK. HAVE INTRODUCED POPS FOR MONDAY WITH SYSTEM PUSHING
EAST...AND MODELS IN GOOD AGREEMENT ON TIMING AND PLACEMENT.
FORCING IS WEAK AND DO NOT HAVE HIGH CONFIDENCE. WEAK SURFACE HIGH
WILL KEEP CONDITIONS DRY UNTIL RIDGE BEGINS TO PUSH EAST FOR MID
WEEK. MODELS ARE NOT IN GOOD AGREEMENT WITH THIS SYSTEM. ECMWF IS
MUCH SLOWER...WITH BOTH ECMWF AND GEM KEEPING PRECIPITATION NORTH
AND SOUTH OF IOWA. GFS CONTINUES TO BRING SYSTEM THROUGH
IOWA...THOUGH BEST FORCING IS FURTHER SOUTH INTO MISSOURI.
THEREFORE...DO NOT HAVE HIGH CONFIDENCE AGAIN IN PRECIPITATION
CHANCES...BUT HAVE KEPT TRENDED TOWARDS THE GFS ATTM. WITH RIDGE
CONDITIONS WILL WARM FRIDAY...THOUGH WILL BE SHORT LIVED WITH
SECOND SYSTEM PUSHING EAST LATE FRIDAY...WITH ADDITIONAL
PRECIPITATION CHANCES INTO SATURDAY. AGAIN...NOT GOOD AGREEMENT ON
TIMING BETWEEN MODELS...AND HAVE BLENDED FOR NOW.
&&
.AVIATION...18/18Z
ISSUED AT 1256 PM CDT SAT JUL 18 2015
VFR THROUGH THE PERIOD UNTIL CONVECTIVE TRENDS BECOME MORE
CLEAR. STILL ANTICIPATING SOME SCATTERED STORMS WILL DEVELOP
DURING THE LATE AFTERNOON OR EVENING HOURS SOUTH AND EAST
SECTIONS...BUT CONFIDENCE IS LOW SO NO CHANGES BEYOND VFR VCTS
WORDING FOR NOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ADAIR-ADAMS-
APPANOOSE-CASS-CLARKE-DALLAS-DAVIS-DECATUR-JASPER-LUCAS-MADISON-
MAHASKA-MARION-MONROE-POLK-POWESHIEK-RINGGOLD-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE.
&&
$$
UPDATE...SMALL
SHORT TERM...DONAVON
LONG TERM...AWB
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS JACKSON KY
134 PM EDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 925 AM EDT SAT JUL 18 2015
WENT AHEAD AND UPDATED THE POPS TO INCLUDE ISOLATED CHANCES ACROSS
THE BOARD BY THIS AFTERNOON. WHILE THERE IS NOTHING GOING ON
ACROSS THE CWA AT THE MOMENT...SHOWERS ARE ALREADY STARTING TO POP
JUST TO OUR NORTH...SO DIDN/T FEEL COMFORTABLE NOT INCLUDING SOME
POSSIBILITY THAT OUR NORTHERN CWA WOULD SEE SOME OF THIS SHOWER
ACTIVITY. STILL THINK THE BEST ACTIVITY WILL DEVELOP ACROSS THE
SOUTHWEST CWA CLOSER TO THE LOCATION OF THE BOUNDARY...SO UPPED
POPS HERE AS WELL TO HIGH END ISOLATED. OVERALL...STILL EXPECT IT
TO BE A VERY HIT AND MISS DAY WITH ONLY LIGHT ACCUMULATIONS
EXPECTED UNDER THE SHOWERS THAT DO DEVELOP. BUT GIVEN THE CURRENT
RADAR WITH SHOWERS POPPING UP AND THE LATEST HI RES
MODELS...WANTED TO GO AHEAD AND INCLUDE EVERYONE IN THE ISOLATED
POTENTIAL.
THAT BEING SAID...THIS UPDATE ALSO INCLUDED AN UPDATE TO THE SKY
COVER...ESPECIALLY FOR THE MORNING HOURS AS HIGH CLOUDS ARE
ALREADY STARTING TO BUILD ACROSS THE AREA. INCREASED CLOUD
COVERAGE THROUGH THE AFTERNOON...BUT CHANGES WERE ONLY
MINOR...WITH FORECAST GROUPS NOW READING PARTLY CLOUDY INSTEAD OF
MOSTLY SUNNY BY THIS AFTERNOON WHEN SOME OF THE DIURNAL CLOUDS
BEGIN DEVELOPING. THIS WAS SUPPORTED BY THE LATEST NAM12 FORECAST
SOUNDINGS...AS WELL AS THE LATEST GFS40 FORECAST SOUNDING...THOUGH
CLOUD LAYERS MAY BE A BIT THINNER ACCORDING TO THE GFS.
FINALLY...ADJUSTED TEMPERATURES FOR TODAY SLIGHTLY. EVEN IF SOME
CLOUD COVER DEVELOPS...DON/T THINK IT WILL HAMPER THE WARM UP TOO
MUCH. AS SUCH...COUNTIES IN THE SW OF THE CWA ARE ALREADY SHOOTING
TO NEAR AND ABOVE 80 DEGREES...AS ARE A FEW IN THE NE CWA. WENT
AHEAD AND BUMPED UP HIGH TEMPERATURES FOR THESE LOCATION A COUPLE
DEGREES HIGHER...TO AROUND 92 INSTEAD OF 90. THIS ALSO MATCHED UP
BETTER WITH THE NEIGHBORING OFFICES WHO HAVE LOW TO MID 90S
FORECAST. WILL CONTINUE TO MONITOR TEMPS THROUGHOUT THE DAY IN
CASE ANY MORE ADJUSTMENTS/UPDATES ARE NEEDED...AS HIGH HUMIDITY
VALUES WILL PLAY A ROLE IN SOME POTENTIALLY PROBLEMATIC HEAT
INDEXES ACROSS THE REGION.
UPDATE ISSUED AT 736 AM EDT SAT JUL 18 2015
LAST OF THE EARLY MORNING SHOWERS HAVE PUSHED OUT OF THE
REGION...WITH DRY WEATHER LIKELY SETTING IN FOR THE REST OF THE
MORNING. HRRR HAS BEEN CONSISTENT ON SHOWING SOME REDEVELOPMENT
ACROSS EASTERN KENTUCKY THROUGH THE MORNING HOURS...BUT HAVE SEEN
NO EVIDENCE OF THIS HAPPENING YET. THUS...WILL MAINTAIN DRY
WEATHER OVER THE NEXT SEVERAL HOURS...BEFORE BRING SOME ISOLATED
SHOWERS/STORMS BACK IN THIS AFTERNOON WITH PEAK HEATING. MAIN AREA
OF FOCUS WILL BE A LEFT OVER OUTFLOW BOUNDARY THAT PUSHES SOUTH
ACROSS SOUTHERN KENTUCKY OVERNIGHT. THIS WILL BEAR WATCHING AS WE
HEAD INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 250 AM EDT SAT JUL 18 2015
COMPLEX OF SHOWERS AND STORMS HAS WEAKENED CONSIDERABLY OVER THE
PAST FEW HOURS AS IT PUSHED INTO EASTERN KENTUCKY. BASED ON RADAR
TRENDS...IT LOOKS AS IF THE COMPLEX MIGHT SET UP A BOUNDARY ACROSS
SOUTHERN KENTUCKY...WHICH COULD TRIGGER ADDITIONAL SHOWER/STORMS
THROUGH DAYBREAK. THIS IDEA SEEMS TO BE WHAT THE LATEST HRRR IS
TRYING TO LATCH ONTO. HOWEVER...HI RES MODELS CONTINUE TO PERFORM
POORLY WITH VERY LITTLE CONSISTENCY. THUS...SHOWER/STORM CHANCES
WILL REMAIN LOW GIVEN THE DEGREE OF UNCERTAINTY. IT DOES LOOK LIKE
WE MAY END UP IN A HOLE OF SORTS TODAY...WITH CONVECTION STAYING
EAST/SOUTH/WEST OF THE AREA. THUS...WE COULD MANAGE A DRY DAY.
HOWEVER...WILL MAINTAIN SOME SLIGHT CHANCES GIVEN THE UNCERTAINTY.
BY TONIGHT...INSTABILITY SHOULD WANE AND RIDGE AXIS SHOULD PLANT
ITSELF OVER THE REGION. THUS...LOOKS LIKE A MUCH QUIETER NIGHT
TONIGHT. THE CLEAR SKIES AND LIGHT WINDS COULD YIELD SOME FOG
POTENTIAL IN THE VALLEYS.
ON SUNDAY...STILL NOT MUCH GOING ON WITH THE WEATHER. WE COULD SEE
A FEW SHOWERS OR STORMS POP UP WITH THE DAYTIME HEATING...BUT
SHOULD BE NOTHING WIDESPREAD AND ONLY WARRANTS A SLIGHT CHANCE AT
THIS POINT.
TEMPERATURES WILL REMAIN NEAR GUIDANCE OVER THE NEXT 36
HOURS...WITH HIGHS NEAR 90 WHICH CERTAINLY IS NOT UNCOMMON FOR
THIS TIME OF YEAR. HUMIDITY LEVELS WILL ALSO REMAIN ELEVATED
THROUGH THE WEEKEND...BUT ALSO FAIRLY TYPICAL FOR THIS TIME OF
YEAR. REGARDLESS...WITH THE SPS FOR HEAT ALREADY OUT...WILL JUST
RIDE WITH IT FOR NOW. IT DOES NOT LOOK LIKE WE WILL GET CLOSE TO
HEAT ADVISORY CRITERIA...ESPECIALLY GIVEN THAT TEMPERATURES MAY
NOT OVERACHIEVE GIVEN THE DEGREE OF GROUND SATURATION FROM RECENT
RAINS...WHICH MAY PUT THE CLAMPS ON HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM EDT SAT JUL 18 2015
NOT THE BEST OF AGREEMENT AMONGST THE GFS AND ECMWF MODELS THIS GO
ROUND. THE EXTENDED PORTION OF THE FORECAST WAS DERIVED FROM A
SLIGHTLY MODIFIED VERSION OF THE EXTENDED MODEL BLEND DATA. IN
GENERAL...THE FORECAST FOR THE UPCOMING WEEK IS SET TO FEATURE
PERIODS OF SHOWERS AND STORMS...MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE BEST CHANCE FOR RAIN AT THIS TIME APPEARS TO BE
MONDAY THROUGH TUESDAY...WHEN A FRONTAL BOUNDARY IS FORECAST TO
STALL ACROSS THE AREA. THE FRONT SHOULD FINALLY MAKE A
SOUTHEASTWARD PUSH ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...ALLOWING RAIN CHANCES TO DECREASE ACCORDINGLY. BY
WEDNESDAY MORNING...ONLY ISOLATED SHOWERS AND STORMS SHOULD
LINGER ACROSS EASTERN KENTUCKY. THAT TREND IS EXPECTED TO CONTINUE
THROUGH FRIDAY NIGHT...AS THE FRONT MAY STALL OUT JUST TO OUR
SOUTH...ALLOWING FOR A FEW SHOWERS AND STORMS TO FORM AS MOISTURE
FROM THE GULF OF MEXICO RIDES UP AND OVER THE BOUNDARY.
TEMPERATURES THROUGH OUT THE PERIOD WILL BE WARM AND MUGGY. DAY
TIME HIGHS WILL TOP OUT MOSTLY IN THE MID TO UPPER 80S...WITH A
FEW LOCATIONS PERHAPS BREAKING 90 ON MONDAY. OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 60S AND LOWER 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 134 PM EDT SAT JUL 18 2015
A FEW POP UP SHOWERS AND THUNDERSTORMS WILL LIKELY CONTINUE
THROUGHOUT THE REMAINDER OF THE AFTERNOON. AS OF NOW...THEY ARE
NOT IMPACTING ANY TAF SITES...AND GIVEN THEIR LIMITED COVERAGE
AREA AND LIFESPAN...CHOSE NOT TO INCLUDE IN TAFS AT THIS TIME. IF
A SHOWER DOES IMPACT A TAF SITE...EXPECT ONLY A BRIEF REDUCTION
IN VISIBILITY. AS WE LOSE DAYTIME HEATING...THESE SHOWERS AND
THUNDERSTORMS WILL DISSIPATE AND HIGH PRESSURE WILL TAKE CONTROL.
THIS WILL ALLOW SKIES TO CLEAR SOME...BUT WILL ALSO TRAP LLVL
MOISTURE NEAR THE SURFACE AND LEAD TO SOME DECENT FOG
DEVELOPMENT...ESPECIALLY IN THE VALLEYS. THE FOG MAY LIFT ONTO THE
RIDGES AND AFFECT THE TAF SITES BEFORE DISSIPATING NEAR AND JUST
AFTER DAWN SUNDAY. AS SUCH...INCLUDED SOME IFR AND POSSIBLE LIFR
CONDITIONS FOR A COUPLE HOURS NEAR DAWN IN THE TAF. FOR
TOMORROW...HEAT AND HUMIDITY WILL CONTINUE...WITH SOME AFTERNOON
CONVECTION POSSIBLE ONCE MORE...ESPECIALLY IN THE FAR EASTERN
PORTION OF THE STATE. GIVEN THE LOW CONFIDENCE ON TIMING AND
LOCATION...CHOSE TO KEEP OUT OF TAFS. OTHERWISE...VFR CONDITIONS
ARE EXPECTED ACROSS THE BOARD WITH GENERALLY LIGHT WSW WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...KAS
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1228 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1228 PM CDT SAT JUL 18 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 18Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THE CONSENSUS OF THE 00Z MODEL CYCLE IS THAT THE UPPER-LEVEL RIDGE
WILL HOLD STRONG ACROSS THE REGION THROUGH THE WEEKEND...AND THEN
IT WILL BE SUPPRESSED TO THE SOUTH/SOUTHWEST ON MONDAY. THE HEAT
ADVISORY LOOKS GOOD FOR TODAY AND SUNDAY. AT THIS TIME...DO NOT
SEE ANYTHING THAT WOULD INDICATE A NEED TO UPGRADE TO A WARNING.
THE MAIN CONCERN IS THE POTENTIAL FOR AT LEAST THE SOUTHERN HALF
OF THE AREA TO NEED A CONTINUATION INTO MONDAY. SINCE THE ENTIRE
AREA HAD 100+ HEAT INDICES YESTERDAY/FRIDAY...MONDAY WOULD BE THE
FOURTH CONSECUTIVE DAY OF 100+ HEAT INDICES WHICH WOULD SUPPORT A
CONTINUATION...EVEN IF ONLY 100-105 IS FORECAST. CONFIDENCE IN THE
MONDAY FORECAST IS QUITE LOW DUE TO A WEAK COLD FRONT AND
ASSOCIATED CONVECTION THAT IS EXPECTED TO BE DRAPED ACROSS THE
REGION. WILL LEAVE THE ADVISORY AS IS FOR NOW. AN UPDATED PRODUCT
WILL BE OUT BY 4 AM.
THE HRRR AND THE NMM AND ARW WRF RUNS ALL DEVELOP SOME ISOLATED TO
WIDELY SCATTERED THUNDERSTORMS OVER ROUGHLY THE EASTERN HALF OF
THE FORECAST AREA FROM MIDDAY TODAY THROUGH THIS AFTERNOON. THIS
WOULD BE DIURNAL ACTIVITY IN A VERY WEAK FLOW REGIME...SO A PULSY
STRONG STORM WILL BE POSSIBLE WITH ISOLATED STRONG WINDS...BUT
ORGANIZED SEVERE WEATHER IS NOT EXPECTED.
POPS WILL BE INCREASING FROM THE NORTH THROUGH THE DAY SUNDAY AND
MUCH OF SUNDAY NIGHT...AS A COLD FRONT APPROACHES THE REGION. THE
CONSENSUS OF 00Z GUIDANCE BRINGS THE FRONT INTO THE AREA IN THE
LATE EVENING AND PUSHES IT THROUGH THE ENTIRE AREA BY 15Z MONDAY.
WILL HAVE POPS UP TO LOW-END LIKELY LEVELS WITH THE FRONT ALONG
THE I-64 CORRIDOR SUNDAY NIGHT. SUNDAY IS LIKELY TO BE DRY...BUT
20-30 POPS ARE FORECAST MAINLY IN THE NORTH JUST TO BE SAFE. POPS
MONDAY WILL BE IN THE CHANCE RANGE DUE TO UNCERTAINTIES IN
FRONTAL LOCATION AND DIURNAL HEATING.
THE FLOW INCREASES SIGNIFICANTLY LATE SUNDAY NIGHT INTO
MONDAY...SO STORMS IN THIS PERIOD WILL LIKELY BE MORE ORGANIZED. A
FEW SEVERE STORMS WITH DAMAGING WINDS WILL BE POSSIBLE. OF COURSE
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING WILL ACCOMPANY ANY
THUNDERSTORMS THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 343 AM CDT SAT JUL 18 2015
THIS EXTENDED FORECAST PACKAGE WOULD BE MORE FRUSTRATING TO DEAL
WITH CONSIDERING THE DAY TO DAY VARIATIONS OF THE DETERMINISTIC
GUIDANCE...PARTICULARLY THE GFS DETERMINISTIC MODEL. WITH THIS
PARTICULAR FORECAST PACKAGE...HAD TO FIGHT AGAINST THE EMPHASIS OF
THE DETERMINISTIC GFS GUIDANCE TO RETROGRADE THE SOUTHERN U.S. RIDGE
LATER IN THE WEEK TO ALLOW FOR FASTER AND SLIGHTLY WETTER FLOW AHEAD
OF THE RIDGE.
LOOKING AT THE WESTERN REGION FORECASTER CONFIDENCE TOOLKIT...THE
ENSEMBLE GUIDANCE...EVEN THE GFS ENSEMBLE CONTINUE TO HINT THAT THE
SOUTHERN U.S. RIDGE WILL REMAIN DOMINANT AND WILL NOT RETROGRADE
LATTER IN THE WEEK. CIPS AND OTHER ANALYSIS/ANALOG/ENSEMBLE PLOTS
CONTINUE TO HINT THAT NEXT WEEKEND /JULY 25-26/ WILL BE THE WARMEST
AND DRIEST SO FAR THIS SUMMER. I WOULD NOT BE SURPRISED IF A SPOT OR
TWO IN SOUTHEAST MISSOURI REACHES 98-100...ESPECIALLY BY NEXT
SATURDAY OR SUNDAY.
WITH THE ADJUSTMENT OF THE GRIDDED FORECAST TOWARD THE WARMER AND
DRIER SOLUTION...ADJUSTED DEWPOINTS DOWNWARD 1-2 DEGREES AND LOWERED
OPAQUE CLOUD COVER INTO THE PARTLY CLOUDY CATEGORY VERSUS MOSTLY
CLOUDY. ALL OF THESE CHANGES WILL SUGGEST AND SUPPORT GREATER
EVAPORATION AND INSOLATION...LEADING TO A LONGER DRY SPELL FOR THE
REGION.
FROM A HEAT STANDPOINT...IT LOOKS LIKE NEXT SATURDAY WILL BRING A
RETURN TO A HEAT ADVISORY (OR HIGHER) TO SOUTHEAST MISSOURI...WITH
HEAT INDEX VALUES NEAR 110 WIDESPREAD ON THAT DAY. SUNDAY DOES NOT
LOOK MUCH BETTER.
THERE REMAINS SOME CHALLENGE AS TO THE IMPACT AND COVERAGE OF
PRECIPITATION TUESDAY THROUGH THURSDAY OF NEXT WEEK.
HOWEVER...DEPENDING ON THE INTERPLAY BETWEEN THE RIDGE AND THE FAST
ZONAL FLOW JUST NORTH OF THE RIDGE...THE WFO PAH FORECAST AREA MAY
STILL SEE SOME CONVECTIVE ACTIVITY THROUGH THURSDAY.
&&
.AVIATION...
ISSUED AT 1228 PM CDT SAT JUL 18 2015
A RIDGE OF HIGH PRESSURE ALOFT SHOULD PRECLUDE THE DEVELOPMENT OF
CONVECTION AND KEEP ALL SITES VFR THROUGH THE PERIOD. SOUTHWEST
WINDS AT 8-14 KNOTS WILL DROP OFF TO AOB 5 KNOTS AROUND 00Z...THEN
SWING AROUND TO WESTERLY AOB 5 KNOTS MAINLY AFTER 15Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR ILZ075>078-080>094.
MO...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR MOZ076-086-087-100-
107>112-114.
IN...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR INZ081-082-085>088.
KY...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...SMITH
AVIATION...JP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
354 PM EDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 326 PM EDT SAT JUL 18 2015
NAM SHOWS A 500 MB TROUGH IN THE NORTHERN PLAINS THIS MORNING THAT
MOVES EAST TODAY AND THROUGH THE AREA TONIGHT.
COMPLICATED FORECAST CONTINUES AS NAM...HRR AND RUC ALL POINT TO NO
REDEVELOPMENT OF CONVECTION THIS AFTERNOON AND EVENING. PROBLEM IS
NONE OF THOSE MODELS ALSO HANDLED THE MCV/QLCS THAT WENT THROUGH
SOUTH OF HERE THIS MORNING EITHER. CANADIAN POINTS TO REDEVELOPMENT
THIS AFTERNOON ALONG WITH GFS AND ECMWF. TO COMPLICATE THINGS
FURTHER...THE 12Z MPX SOUNDING IS FAIRLY DRY AND CAPPED WHILE THE
12Z INL SOUNDING IS UNSTABLE AND MOIST. CONFIDENCE IS LOW THOUGH
WITH THIS FORECAST AND APPEARS THAT THE DRIER AND CAPPED MODEL
SOLUTION SEEMS TO BE VERIFYING AND WILL GO WITH THAT SCENARIO. ONLY
PROBLEM IS THAT IF SOMETHING WOULD GO...IT WOULD GO SEVERE IN A
HURRY AS STRONGER SHEAR AND STRONGER WINDS ARE FORECASTED TO COME IN
LATE THIS AFTERNOON...BUT WITH CAPPED ATMOSPHERE OVER THE
AREA...THINKING IS CUTTING POPS TO SLIGHT CHANCE IS THE WAY TO GO
WITH COLD FRONT COMING THROUGH THIS EVENING AND WILL GO SLIGHT
CHANCE IN CASE SOMETHING IS ABLE TO BREAK THAT CAP. STILL THINK
SMALL HAIL AND WIND GUSTS ARE POSSIBLE
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. CUT BACK ON THE POPS THIS AFTERNOON AND TONIGHT AND
WENT SLIGHT CHANCE ONLY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 353 PM EDT SAT JUL 18 2015
SUNDAY NIGHT THROUGH MONDAY NIGHT...AN UPPER LEVEL 500MB CLOSED LOW
AND ASSOCIATED SURFACE LOW WILL REMAIN NEARLY STATIONARY OVER HUDSON
BAY THROUGH THIS TIME PERIOD. THE MAIN IMPACTS FROM THIS WILL COME
FROM A SHORTWAVE AND SURFACE TROUGH/COLD FRONT...STRETCHING
SOUTHWEST INTO NORTHWEST MN SUNDAY NIGHT. THESE FEATURES WILL SLIDE
TO THE EAST...CROSSING THE U.P. BETWEEN 18Z/20 AND 00Z/21. THE VORT
MAX IS PROGGED TO REMAIN OVER LAKE SUPERIOR AND FARTHER NORTH OF
THE U.P. THIS CAN ALSO BE SEEN BY OVERLAYING DEEP LAYER 850MB-300MB
QCONV WITH DEEP LAYER RH. THERE WILL NOT BE A LOT OF MOISTURE TO
WORK WITH LIMITING THE POPS TO SLIGHT CHANCE DURING THIS TIME
PERIOD...AGAIN...THE BEST CHANCES WILL BE MONDAY AFTERNOON INTO THE
EARLY EVENING HOURS...DURING FRONTAL PASSAGE. HIGH TEMPERATURES
MONDAY AFTERNOON WILL WARM INTO THE MID 80S AHEAD OF THE COLD FRONT
AS 850MB TEMPS WARM TO AROUND 18C TO 19C...BEFORE COOLING FROM WEST
TO EAST LATE IN THE AFTERNOON INTO THE EVENING.
TUESDAY THROUGH WEDNESDAY NIGHT...AN ADDITIONAL...VERY WEAK WAVE
WILL SLIDE TO THE NORTH OF THE U.P. LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT LITTLE TO NO PRECIP IS EXPECTED FROM THIS
SYSTEM WITH CONTINUED LIMITED MOISTURE AROUND ALONG WITH VERY WEAK
FORCING. ADDITIONALLY...A SURFACE RIDGE WILL BEGIN BUILDING INTO THE
REGION BRINGING ANTICYCLONIC FLOW ALONG WITH EVEN DRYER AIR. THIS
HIGH PRESSURE CENTER WILL CONTINUE TO SLIDE ACROSS THE UPPER GREAT
LAKES REGION TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT ALLOWING FOR
MAINLY DRY CONDITIONS UNDER A MOSTLY CLEAR TO PARTLY CLOUDY SKY.
850MB TEMPS WILL FALL TO AROUND 12C TO 13C TUESDAY AFTERNOON AND
WEDNESDAY AFTERNOON ALLOWING TEMPERATURES TO COOL BACK TO THE MID
70S...WHICH IS CLOSE TO NORMAL FOR THIS TIME OF YEAR.
THURSDAY THROUGH SATURDAY...MODELS SHOW AN UPPER LEVEL 500MB RIDGE
AXIS SLIDING ACROSS THE UPPER GREAT LAKES REGION THURSDAY INTO
THURSDAY NIGHT IN ADVANCE OF A DEVELOPING LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT...ALLOWING TEMPERATURES TO WARM ONCE AGAIN.
THE COLD FRONT IS EXPECTED TO SLIDE ACROSS THE AREA FRIDAY AFTERNOON
THROUGH SATURDAY BRINGING THE NEXT...WIDESPREAD...CHANCE FOR SHOWERS
AND THUNDERSTORMS. AT THIS POINT DECIDED TO STICK WITH A CONSENSUS
OF THE MODELS DURING THIS TIME PERIOD...WHICH SEEMED REASONABLE WITH
TIMING OF THE FRONT. AS IS USUALLY THE CASE...BEING THIS FAR THERE
WILL LIKELY NEED TO BE ADJUSTMENTS TO TIMING AND INTENSITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 121 PM EDT SAT JUL 18 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. CURRENT
THINKING IS WE WILL STAY CAPPED THIS AFTERNOON AND EVENING WHICH
WOULD PREVENT CONVECTION FROM BREAKING OUT AS A COLD FRONT PASSES
THROUGH THIS EVENING. CONFIDENCE IS LOW THOUGH AS COMPUTER MODELS
DID POORLY WITH COMPLEX THAT WENT TO THE SOUTH OF THE AREA THIS
MORNING AND SOME ARE INDICATING REDEVELOPMENT THIS AFTERNOON AND
SOME ARE DRY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT SAT JUL 18 2015
ALTHOUGH WINDS WILL BE UNDER 20 KTS INTO TNGT... STRONGER WINDS WILL
BE POSSIBLE IN THUNDERSTORMS TODAY INTO TONIGHT AHEAD OF AN
APPROACHING COLD FRONT AS WATER TEMPS ARE WARMING UP...WHICH WILL
LIMIT LOW-LEVEL STABILITY AND INCREASE THE CHANCE STRONGER WINDS
WILL BE TRANSPORTED TO THE SURFACE. THEN TIGHTENING PRES GRADIENT
BEHIND THE COLD FRONT CROSSING THE LAKE TONIGHT AND BETWEEN HI PRES
MOVING THRU THE NCENTRAL PLAINS AND LO PRES OVER HUDSON BAY WILL
BRING SOME WSW WINDS AS HI AS 25 KTS FROM LATE TONIGHT AND SUN. THE
BEST CHANCE FOR MORE PERSISTENT...STRONGER WINDS WILL BE OVER THE W
AND NCENTRAL PORTIONS BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE
TERRAIN WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER SUN NIGHT WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT
DOMINATES NEXT WEEK. RATHER HUMID AIR WILL CAUSE SOME FOG OVER
MAINLY THE COOLER WATERS OF NORTHERN LAKE SUPERIOR THROUGH MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...KEC
AVIATION...07
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
326 PM EDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 326 PM EDT SAT JUL 18 2015
NAM SHOWS A 500 MB TROUGH IN THE NORTHERN PLAINS THIS MORNING THAT
MOVES EAST TODAY AND THROUGH THE AREA TONIGHT.
COMPLICATED FORECAST CONTINUES AS NAM...HRR AND RUC ALL POINT TO NO
REDEVELOPMENT OF CONVECTION THIS AFTERNOON AND EVENING. PROBLEM IS
NONE OF THOSE MODELS ALSO HANDLED THE MCV/QLCS THAT WENT THROUGH
SOUTH OF HERE THIS MORNING EITHER. CANADIAN POINTS TO REDEVELOPMENT
THIS AFTERNOON ALONG WITH GFS AND ECMWF. TO COMPLICATE THINGS
FURTHER...THE 12Z MPX SOUNDING IS FAIRLY DRY AND CAPPED WHILE THE
12Z INL SOUNDING IS UNSTABLE AND MOIST. CONFIDENCE IS LOW THOUGH
WITH THIS FORECAST AND APPEARS THAT THE DRIER AND CAPPED MODEL
SOLUTION SEEMS TO BE VERIFYING AND WILL GO WITH THAT SCENARIO. ONLY
PROBLEM IS THAT IF SOMETHING WOULD GO...IT WOULD GO SEVERE IN A
HURRY AS STRONGER SHEAR AND STRONGER WINDS ARE FORECASTED TO COME IN
LATE THIS AFTERNOON...BUT WITH CAPPED ATMOSPHERE OVER THE
AREA...THINKING IS CUTTING POPS TO SLIGHT CHANCE IS THE WAY TO GO
WITH COLD FRONT COMING THROUGH THIS EVENING AND WILL GO SLIGHT
CHANCE IN CASE SOMETHING IS ABLE TO BREAK THAT CAP. STILL THINK
SMALL HAIL AND WIND GUSTS ARE POSSIBLE
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. CUT BACK ON THE POPS THIS AFTERNOON AND TONIGHT AND
WENT SLIGHT CHANCE ONLY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 357 AM EDT SAT JUL 18 2015
UPR MI WL BE DOMINATED BY A PROGRESSIVE WNW FLOW ALOFT BTWN UPR RDG
OVER THE SRN CONUS AND SOME TROFFING OVER ERN CANADA FOR MUCH OF THE
COMING MEDIUM/EXTENED FCST PERIOD. TIMING DISTURBANCES MOVING THRU
THIS FLOW AND THEIR IMPACT ON UPR MI WL BE THE PRIMARY FCST CONCERNS.
SUN...ARRIVAL OF LARGER SCALE QVECTOR DVGC/SUBSIDENCE...MID LVL
DRYING AND OVERALL ACYC WNW FLOW BEHIND DEPARTING COLD FROPA...
EXPECT A MOSUNNY DAY. WITH H85 TEMPS FCST TO REACH WITHIN A FEW
DEGREES OF 14C...TEMPS SHOULD TOP OUT IN THE 80 TO 85 RANGE AWAY FM
THE COOLING INFLUENCE OF LK SUP. A STEADY/GUSTY W WIND UNDER FAIRLY
TIGHT PRES GRADIENT TO THE NE OF SFC HI PRES CENTER MOVING TOWARD
THE MID MS RIVER VALLEY WL MAKE THE AIR FEEL A BIT COOLER.
SUN NGT...MODELS INDICATE ANOTHER SHRTWV/SFC LO EMBEDDED IN THE WNW
FLOW ALF WL TRACK THRU NW ONTARIO. SINCE THE BULK OF THE DPVA/LARGER
SCALE FORCING AND DEEP MOISTENING WL STAY TO THE N WITH DRY AIR
LINGERING OVER THE CWA...WL CARRY LO CHC POPS NO FARTHER S THAN NRN
LK SUP. SINCE THE SFC HI PRES CENTER WL BE WELL TO THE S...SHARPER
PRES GRADIENT BTWN THE LO TO THE N/STEADY W FLOW WL TEND TO LIMIT
THE DIURNAL TEMP DROP EVEN THOUGH SKIES WL BE CLR OVER THE S/PCLDY
TO THE N.
MON/MON NGT...FOLLOWING PASSAGE OF ONTARIO SHRTWV/SFC LO TO THE E...
ATTENDANT COLD FNT IS FCST TO MOVE INTO THE FAR NW CWA LATE IN THE
DAY AND THEN CROSS UPR MI ON MON NGT. WITH AN ABSENCE OF ANY SGFNT
MSTR INFLOW...POPS ACCOMPANYING THE FROPA WL BE LIMITED EVEN IF THE
MODELS THAT SHOW A STRONGER TRAILING SHRTWV/POCKET OF SHARPER DEEP
LYR QVECTOR CNVGC CATCHING UP TO THE FNT ARE CORRECT. SINCE THE FNT
WL BE AT LEAST APRCHG THE NW CWA LATE IN THE DAY WHEN DIURNAL
HEATING WL STILL BE A FACTOR...SEEMS LIKE THE BEST SHOT FOR SOME SCT
SHOWERS/TS WL BE IN THAT AREA. COMBINATION OF NEGATIVE H85 THETA E
ADVECTION/LARGER SCALE DRYING AND NOCTURNAL COOLING WL CAUSE ANY
SHOWERS TO DIMINISH OVERNGT. THE WARMEST TEMPS ON MON AFTN WL BE
OVER THE SCNTRL AWAY FM LK MI MODERATION. FCST H85 THERMAL RDG IN
THE 15-17C RANGE WL SUPPORT MAX TEMPS WELL INTO THE 80S.
TUE/WED...MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT SHOWING SFC HI
PRES/SOMEWHAT COOLER AIR UNDER NW FLOW ALF TO THE W OF UPR TROF
DEEPENING INTO QUEBEC WL DOMINATE DURING THIS TIME. H85 TEMPS ARE
FCST TO BE ABOUT 11C ON TUE AFTN AND 13-14C ON WED...SUPPORTING HI
TEMPS MAINLY IN THE 70S AWAY FM LK COOLING. WITH PWAT FCST AS LO AS
0.75 INCH AND LIGHT WINDS ON TUE NGT UNDER THE INCOMING HI PRES...
SOME OF THE COOLER INTERIOR SPOTS COULD SEE LO TEMPS DROP INTO THE
40S.
WED NGT THRU FRI...IN GENERAL...THE EXTENDED RANGE GUIDANCE POINT TO
A BLDG UPR RDG OVER CENTRAL NAMERICA EXPANDING INTO THE GREAT LKS AS
TROF IN QUEBEC EDGES SLOWLY TO THE E. SHRTWV FCST TO RIDE THRU THE
UPR MIDWEST TO THE E OF THE BLDG RDG IN THE PLAINS WL SUPPORT SOME
CHC POPS WED NGT THRU THU...BUT MODEL TRENDS TOWARD A WEAKER SHRTWV/
MORE RESILIENT UPR HGTS/HIER MSLP OVER THE CWA SUGGEST PCPN CHCS ARE
LOWER THAN WHAT APPEARED IN PREVIOUS SHIFTS. BLDG HI PRES UNDER THE
ARPCHG RDG SHOULD BRING MAINLY DRY WX FOR FRI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 121 PM EDT SAT JUL 18 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. CURRENT
THINKING IS WE WILL STAY CAPPED THIS AFTERNOON AND EVENING WHICH
WOULD PREVENT CONVECTION FROM BREAKING OUT AS A COLD FRONT PASSES
THROUGH THIS EVENING. CONFIDENCE IS LOW THOUGH AS COMPUTER MODELS
DID POORLY WITH COMPLEX THAT WENT TO THE SOUTH OF THE AREA THIS
MORNING AND SOME ARE INDICATING REDEVELOPMENT THIS AFTERNOON AND
SOME ARE DRY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT SAT JUL 18 2015
ALTHOUGH WINDS WILL BE UNDER 20 KTS INTO TNGT... STRONGER WINDS WILL
BE POSSIBLE IN THUNDERSTORMS TODAY INTO TONIGHT AHEAD OF AN
APPROACHING COLD FRONT AS WATER TEMPS ARE WARMING UP...WHICH WILL
LIMIT LOW-LEVEL STABILITY AND INCREASE THE CHANCE STRONGER WINDS
WILL BE TRANSPORTED TO THE SURFACE. THEN TIGHTENING PRES GRADIENT
BEHIND THE COLD FRONT CROSSING THE LAKE TONIGHT AND BETWEEN HI PRES
MOVING THRU THE NCENTRAL PLAINS AND LO PRES OVER HUDSON BAY WILL
BRING SOME WSW WINDS AS HI AS 25 KTS FROM LATE TONIGHT AND SUN. THE
BEST CHANCE FOR MORE PERSISTENT...STRONGER WINDS WILL BE OVER THE W
AND NCENTRAL PORTIONS BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE
TERRAIN WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER SUN NIGHT WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT
DOMINATES NEXT WEEK. RATHER HUMID AIR WILL CAUSE SOME FOG OVER
MAINLY THE COOLER WATERS OF NORTHERN LAKE SUPERIOR THROUGH MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...KC
AVIATION...07
MARINE...07
AREA FORECAST DISCUSSION
NWS DULUTH MN
341 PM CDT SAT JUL 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT JUL 18 2015
CONCERN FOR THE SHORT TERM IS PRECIP CHANCES THIS EVENING.
CURRENT SURFACE ANALYSIS INDICATES THUNDERSTORMS JUST NORTH OF THE
ARROWHEAD IN SOUTHERN CANADA. HRRR INDICATES THERE COULD BE SOME
SPOTTY PRECIP ACROSS THE BORDERLAND THIS EVENING BEHIND THE FRONT
AND A WEAK SHORTWAVE MOVE THROUGH THE REGION. FOR THE REST OF THE
FORECAST AREA THIS AFTERNOON...SKIES WILL STAY PARTLY CLOUDY AS
THE FRONT (IN NW WI AT 20Z) WILL CONTINUE TO MOVE THROUGH THE AREA.
IF ANY PRECIP DEVELOPS...IT WILL BE WIDELY SCATTERED. THE 12Z MPX
SOUNDING WAS CAPPED AND THERE IS NOT MUCH VERTICAL DEVELOPMENT TO
THE CLOUDS AS INDICATED BY OBSERVATION AND SATELLITE. ALL OF THE FORECAST
AREA WILL SEE CLEAR TO PARTLY CLOUDY SKIES LATER THIS EVENING
THROUGH THE OVERNIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE
REGION LATE TONIGHT AND WILL CAUSE PARTLY TO MOSTLY SUNNY SKIES ON
SUNDAY WITH LESS HUMID CONDITIONS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT JUL 18 2015
SUNDAY NIGHT...A COLD FRONT WILL MOVE INTO NORTHERN MINNESOTA
SUNDAY EVENING...THEN FINISH MOVING THROUGH THE REST OF THE
NORTHLAND OVERNIGHT INTO MONDAY MORNING. THE
GEM/GFS/ECMWF/NAM/SREF/WRF ARE INDICATING THE POTENTIAL FOR PCPN
OVER THE NORTHERN FORECAST AREA WITH THE PASSAGE OF THE COLD
FRONT. THE GEM IS THE MOST AGGRESSIVE WITH PCPN. THERE COULD BE
ENOUGH INSTABILITY FROM THE DAYTIME HEATING LEFT OVER IN THE
EVENING FOR THE COLD FRONT TO SET OFF SOME SHOWERS. THE THREAT OF
THUNDER LOOKS TO BE VERY LOW. THE NAM12/SREF/GFS INDICATE NEARLY
NO CAPE. IT APPEARS WARM UPPER LEVEL TEMPERATURES WILL LIMIT
MUCAPE FROM GETTING MUCH MORE THAN 100 OR 200 J/KG. LEFT THUNDER
OUT OF THE FORECAST SINCE THE THREAT OF THUNDER SEEMS SO LOW.
MONDAY...SLIGHTLY COOLER AND LESS HUMID WEATHER IS EXPECTED IN THE
NW FLOW PATTERN. THE CONVECTIVE TEMPERATURES SHOULD BE LOW ENOUGH TO
POP SCATTERED/BROKEN CUMULUS BY THE EARLY AFTERNOON FOR MOST AREAS.
HIGH TEMPERATURES SHOULD RANGE FROM THE LOWER 70S OVER THE NORTH TO
NEAR 80 IN NW WISCONSIN. BUMPED UP THE TEMPERATURE FOR PARK POINT
BEACH TO 83 TO ACCOUNT FOR DOWNSLOPE WARMING.
TUESDAY...HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST...PROVIDING
THE NORTHLAND WITH A SUNNY AND COMFORTABLE DAY. HIGHS SHOULD BE IN
THE MIDDLE 70S.
WEDNESDAY THROUGH FRIDAY...THE GFS/ECMWF/GEM GENERALLY INDICATE AN
UPPER LEVEL RIDGE WILL SHIFT FROM THE WESTERN PLAINS INTO UPPER
MIDWEST DURING THIS TIMEFRAME. THIS WILL BRING A WARMING TREND
THROUGH FRIDAY...WITH HIGHS BUILDING BACK INTO THE 80S FOR THE LATE
WEEK. THE WARM LOW LEVEL SOUTHERLY FLOW PATTERN WILL CAUSE AFTERNOON
AND EARLY EVENING INSTABILITY FROM DAYTIME HEATING...BUT THERE IS
GENERALLY VERY LOW CHANCES OF SHOWERS AND THUNDERSTORMS IN THE
ABSENCE OF ANY SIGNIFICANT FORCING MECHANISM. THERE ARE SOME SIGNS A
SHORTWAVE TROUGH COULD LIFT THROUGH THE NORTHERN PLAINS OR WESTERN
LAKE SUPERIOR REGION SOMETIME WEDNESDAY NIGHT THROUGH FRIDAY...WHICH
WOULD GIVE A BETTER OPPORTUNITY FOR SHOWER AND STORM
DEVELOPMENT...BUT THE MODELS ARE LACKING AGREEMENT ON ITS TIMING.
THE GFS HAS THE SHORTWAVE TROUGH MOVING THROUGH THURSDAY...THE ECMWF
THURSDAY NIGHT...AND THE GEM NOT UNTIL FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1234 PM CDT SAT JUL 18 2015
CONDITIONS HAVE WAFFLED BETWEEN VFR/MFVR THIS MORNING ACROSS OUR
TAF SITES AS 3KFT CIGS HAVE GONE SCATTERED.... THEN BROKEN... THEN
SCATTERED AGAIN. GENERALLY EXPECTING PREVAILING VFR OVER THE NEXT
24 HOURS... BUT HIGH END MVFR WILL NOT BE OUT OF THE QUESTION IN
THE SHORT TERM AS THE DRY COLD FRONT PASSES THROUGH MINNESOTA
TODAY. EXPECT GUSTY SW WINDS UP TO 30 KTS THIS AFTERNOON...
BECOMING LIGHTER OUT OF THE WEST OVERNIGHT... BUT STILL PERSISTING
AT 5 TO 10 KTS BEFORE BECOMING GUSTY AGAIN TOMORROW AFTER 15Z.
THERE WILL BE A CHANCE OF SCATTERED SHOWERS AS THE FRONT MOVES
THROUGH TODAY... BUT LATEST ANALYSIS FROM THE HRRR KEEPS SHOWER
COVERAGE VERY LOW. DUE TO LOW OVERALL SHOWER CONFIDENCE... REMOVED
MENTION OF VCTS FROM HYR... BUT MAY UPDATE TO ADD IT BACK IF
CONDITIONS CHANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 60 79 62 79 / 10 0 0 10
INL 55 78 59 72 / 10 10 40 20
BRD 59 82 64 80 / 10 0 0 10
HYR 59 80 63 80 / 10 0 0 10
ASX 60 80 64 79 / 10 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...STEWART
LONG TERM...GROCHOCINSKI
AVIATION...MCLOVIN
AREA FORECAST DISCUSSION
NWS DULUTH MN
1247 PM CDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1234 PM CDT SAT JUL 18 2015
UPDATED FOR 18Z AVIATION DISCUSSION BELOW
UPDATE ISSUED AT 1003 AM CDT SAT JUL 18 2015
UPDATED TEMP AND PRECIP POP GRIDS BASED ON LATEST LOOK AT MODELS
AND CURRENT OBS. AT 15Z...COLD FRONT EXTENDED FROM CDD TO AIT TO
LJF. IT SHOULD REACH THE TWIN PORTS AROUND 17Z AND AN ASX-HYR
LINE BY 22Z. SATELLITE WAVE SHOWS CLOUDS AHEAD OF THE FRONT
EXTENDING FROM DLH TO CHG WHICH SHOWS SOME LIFT OCCURRING IN THAT
AREA. THAT LINE WILL BE THE FOCUS OF ANY DEVELOPMENT OF
THUNDERSTORMS. THE 13Z DAY ONE CONVECTIVE OUTLOOK PULLED THE
MARGINALAND SLIGHT RISK INTO SOUTHERN WISCONSIN. SPC INDICATED
THERE WILL NOT BE ANY ORGANIZED SEVERE THUNDERSTORMS BUT THERE
COULD BE AN ISOLATED SVR THUNDERSTORM WITH HAIL AND DAMAGING
WINDS. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT SAT JUL 18 2015
STRONG MCS EARLY THIS MORNING OVER SOUTHEAST MN/WESTERN WI
CONTINUING TO MOVE EAST...PRODUCING SOME SIGNIFICANT WIND DAMAGE
THERE. THE STRATIFORM RAIN ON THE NORTH SIDE OF THIS MCS IS
AFFECTING MY SOUTHERN CWA...WHICH IS EXPECTED TO CONTINUE TO SLIDE
EAST FOR THE NEXT FEW HOURS...AND HAVE PUT IN SOME HIGH POPS FOR
THIS. THIS IS ALL AHEAD OF A MESO LOW OVER CENTRAL MN...WHICH
SHOULD CONTINUE TO SWEEP EAST AS WELL. ANOTHER AREA OF SHOWERS AND
THUNDERSTORMS HAS DEVELOPED OVER NORTHWEST MINNESOTA... WHICH IS
SLOWLY DRIFTING NORTHEAST INDICATIVE OF ITS ELEVATED NATURE IN A
MID LEVEL CONVERGENCE AND FRONTOGENESIS ZONE. THE MAIN SURFACE LOW
IS STILL OVER SOUTHERN SASKATCHEWAN AND IS ASSOCIATED WITH THE
UPPER LOW ALSO OVER THE REGION. AS THE MAIN SURFACE LOW MOVES EAST
TODAY WE WILL GET ADDITIONAL DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS IN VICINITY OF ANY SURFACE BOUNDARY THE NEXT 12-18
HOURS BEFORE THE MAIN SURFACE LOW AND COLD FRONT SWEEP EAST. UNTIL
THEN...THE MAIN AXIS OF INSTABILITY HAS BEEN ASSOCIATED WITH THE
OVERNIGHT MCS...AND WHILE ANOTHER MAY DEVELOP UP INTO THE CWA THIS
MORNING...IT WILL NOT GET AS UNSTABLE BEFORE BEING SWEPT EAST BY
EARLY AFTERNOON...DESPITE VERY GOOD SHEAR. THUS...SEVERE THREAT
FOR THE CWA IS LOOKING PRETTY MINIMAL...THOUGH IF THE TIMING IS
JUST RIGHT THE SOUTHEAST CORNER IS MOST AT RISK AS DEPICTED IN
THE DAY ONE SPC OUTLOOK. MAX TEMPERATURES TO GET VERY WARM WITH
DEEP MIXING AND A FAIR AMOUNT OF SUNSHINE CONTRIBUTING TO HIGHS
RANGING FROM AROUND 80 AROUND INL...TO THE MID 80S OVER NW WI.
TONIGHT AND SUNDAY GET MUCH QUIETER WITH THE COLD FRONT EAST OF
THE AREA AND WESTERLIES BRINGING IN COOLER AND DRIER AIR. SUNDAY
TO HAVE HIGHS IN THE MID 70S TO LOW 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 AM CDT SAT JUL 18 2015
A WEAK COLD FRONT WILL DROP IN FROM THE NORTH LATE SUNDAY NIGHT AND
THROUGH THE DAY MONDAY...PRODUCING ADDITIONAL CLOUD COVER OVER MUCH
OF THE REGION AND A CHANCE OF SHOWERS AND A FEW WEAK THUNDERSTORMS.
THE MOST FAVORABLE AREA TO SEE PRECIPITATION WILL BE ACROSS THE
ARROWHEAD AND INTO NW WI. HIGH PRESSURE AT THE SURFACE AND RIDGING
ALOFT WILL COMBINE WITH DRY AIR MOVING IN TO KEEP CONDITIONS QUIET
MONDAY NIGHT THROUGH TUESDAY NIGHT. THERE WILL BE INCREASING CHANCES
FOR SHOWERS AND STORMS ON WED...BUT CONFIDENCE IS LOW AT THIS TIME
DUE TO DISAGREEMENT AMONG MODEL GUIDANCE. A MORE DOMINANT HIGH
BUILDS IN THURSDAY AND FRIDAY WITH A RETURN TO THE ACTIVE PATTERN BY
THE WEEKEND WITH MORE SHOWERS AND STORMS.
TEMPERATURES WILL STILL BE WARM BUT NOT AS HUMID ON MONDAY WITH
HIGHS TOPPING OUT IN THE LOWER TO MID 80S. NOTICEABLY COOLER
CONDITIONS WILL BE FELT ON TUESDAY...IN THE MID 70S...BUT THROUGH
THE REST OF THE WEEK A GRADUALLY WARMING TREND WILL DEVELOP WITH
HIGHS IN THE LOWER 80S BY FRIDAY. OVERNIGHT LOWS WILL REMAIN MILD IN
THE 50S AND 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1234 PM CDT SAT JUL 18 2015
CONDITIONS HAVE WAFFLED BETWEEN VFR/MFVR THIS MORNING ACROSS OUR
TAF SITES AS 3KFT CIGS HAVE GONE SCATTERED.... THEN BROKEN... THEN
SCATTERED AGAIN. GENERALLY EXPECTING PREVAILING VFR OVER THE NEXT
24 HOURS... BUT HIGH END MVFR WILL NOT BE OUT OF THE QUESTION IN
THE SHORT TERM AS THE DRY COLD FRONT PASSES THROUGH MINNESOTA
TODAY. EXPECT GUSTY SW WINDS UP TO 30 KTS THIS AFTERNOON...
BECOMING LIGHTER OUT OF THE WEST OVERNIGHT... BUT STILL PERSISTING
AT 5 TO 10 KTS BEFORE BECOMING GUSTY AGAIN TOMORROW AFTER 15Z.
THERE WILL BE A CHANCE OF SCATTERED SHOWERS AS THE FRONT MOVES
THROUGH TODAY... BUT LATEST ANALYSIS FROM THE HRRR KEEPS SHOWER
COVERAGE VERY LOW. DUE TO LOW OVERALL SHOWER CONFIDENCE... REMOVED
MENTION OF VCTS FROM HYR... BUT MAY UPDATE TO ADD IT BACK IF
CONDITIONS CHANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 83 60 78 62 / 20 10 0 0
INL 79 55 77 59 / 40 10 10 10
BRD 82 59 80 61 / 10 10 0 0
HYR 84 59 78 60 / 30 10 0 0
ASX 86 60 80 60 / 30 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...LE
LONG TERM...TENTINGER
AVIATION...MCLOVIN
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
122 PM CDT SAT JUL 18 2015
.UPDATE:
ISSUED AT 112 PM CDT SAT JUL 18 2015
WITH LINGERING CLOUD COVER AND SCATTERED SHOWERS, ISOLATED
THUNDERSTORMS OVER PORTIONS OF THE FORECAST AREA, HAVE CANCELLED
SOME OF THE HEAT ADVISORY. THE ADVISORY HAS BEEN CANCELLED FOR
AREAS ALONG AND NORTH OF A COLUMBIA, MO TO MONTGOMERY CITY, MO TO
PITTSFIELD, IL LINE. OTHERWISE, ADJUSTED HIGH TEMPS FOR EVERYONE
ELSE DOWN A DEGREE OR TWO DUE TO THE CLOUD COVER, BUT STILL EXPECT
HEAT INDICES IN THE 100 TO 109 DEGREE RANGE THIS AFTERNOON.
BYRD
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 410 AM CDT SAT JUL 18 2015
FIRST FORECAST CHALLENGE FOR TODAY IS POPS. SEEING EXPANDING
COVERAGE IN ISOLATED TO WIDELY SCATTERED CONVECTION OVER WEST
CENTRAL/NORTHWEST MISSOURI AT THIS TIME. HRRR SEEMS TO BE HANDLING
THIS WAA PRECIP THE BEST AT THE MOMENT, BUT LATEST RUNS OF THE RAP
DO SEEM TO BE CATCHING UP. FORECAST SOUNDINGS SHOW THE PROVERBIAL
CAP OF FORGED STEEL DEVELOPING...SO SURFACE BASED CONVECTION LOOKS
PRETTY UNLIKELY. MY GUT FEELING IS THAT THE HRRR IS TOO AGGRESSIVE
IN BOTH AREAL COVERAGE AND LONGEVITY IN KEEPING PRECIP GOING THROUGH
LATE MORNING AND EARLY AFTERNOON...AND THE RAP MAY NOT BE AGGRESSIVE
ENOUGH, SO I WENT SOMEWHERE IN BETWEEN INCREASING POPS TO SLIGHT
CHANCE ACROSS CENTRAL AND NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS.
SECOND CHALLENGE IS TEMPERATURES...AND THE HEAT ADVISORY WHICH IS
ALREADY IN EFFECT. OBVIOUSLY, PRECIPITATION AND CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TODAY. IF THE HRRR IS MORE RIGHT
THAN WRONG TODAY, THEN ITS UNLIKELY THAT TEMPERATURES WILL HIT THE
MID AND UPPER 90S AS PER THE CURRENT FORECAST. STUCK WITH THE
WARMER FORECAST AND USED A BLEND OF GUIDANCE FOR HIGHS...LEANING
TOWARD A MIX-DOWN OF 850MB GFS TEMPERATURES. NO CHANGE TO THE HEAT
HEADLINES IS ANTICIPATED AT THIS TIME WITH THE CAVEAT THAT THIS
MORNING`S PRECIP DOESN`T DEVELOP INTO SOMETHING MORE SUBSTANTIAL.
CARNEY
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT JUL 18 2015
HEAT REMAINS THE PRIMARY FORECAST CONCERN THRU SUNDAY...AND PERHAPS
INTO MONDAY.
UPPER LEVEL RIDGE DOMINATING THE SOUTHERN CONUS WILL CONTINUE TO
COMMAND A STRONG INFLUENCE INTO OUR REGION INTO SUNDAY...BUT IS
EXPECTED TO BEGIN TO BREAKDOWN A BIT FROM THE NORTH AS THE FIRST IN
A SERIES OF UPPER LEVEL DISTURBANCES PASS THRU. AT THE SURFACE...
THIS WILL EQUATE TO OUR REGION REMAINING IN A S-SW FLOW INTO
SUNDAY...WITH A COLD FRONT DROPPING DOWN MAINLY FROM THE AFTERNOON
HOURS ONWARD. WHILE THIS FRONT IS EXPECTED TO SETTLE ACROSS
SOUTHERN MO AND FAR SOUTHERN IL BY SUNDAY NIGHT...THERE IS
INCREASING EVIDENCE IN THE MODELS THAT THIS FIRST FRONT WILL
DISSOLVE SUNDAY NIGHT WITH A SW FLOW RESUMING ALREADY ON MONDAY IN
TIME FOR ANOTHER FRONT TO DROP DOWN DURING THE AFTERNOON.
REFERENCE SHORT-TERM DISCUSSION ON HEAT FORECAST FOR TODAY.
THE DANGEROUS HEAT AND HUMIDITY IS STILL EXPECTED TO CONTINUE INTO
SUNDAY FOR MUCH OF OUR REGION...ENOUGH TO WARRANT MAINTAINING A HEAT
ADVISORY...ALTHOUGH WITH INCREASING UNCERTAINTY ON ITS NORTHERN
PERIPHERY...AS WHAT LOOKS TO BE A NOCTURNAL CONVECTIVE EVENT WILL
TAKE HOLD FOR LATE TONIGHT AND CARRY INTO SUNDAY MORNING FOR AREAS
MAINLY NORTH OF I-70. THIS WILL BRING WITH IT THE ASSOCIATED DEBRIS
CLOUD THAT WILL PROBABLY LINGER INTO SUNDAY AFTERNOON AND FURTHER
COMPLICATE TEMPS AND HEAT INDEX VALUES WITH A DECENT GRADIENT
SOMEWHERE IN THE VICINITY OF I-70... ALL THE WHILE WITH THE SURFACE
COLD FRONT DROPPING INTO THIS AREA AS WELL DURING THE AFTERNOON.
SOME AREAS MAY EVENTUALLY NEED TO BE LOPPED OFF FROM THE HEAT
ADVISORY BUT THE CONFIDENCE FOR DOING IT THIS PACKAGE IS NOT THERE.
TO FURTHER COMPLICATE THINGS...THE POSSIBLE DISSOLUTION OF THE FRONT
SUNDAY NIGHT AND RETURN OF THE HEAT ALREADY BY MONDAY MAY
NECESSITATE AN EXTENSION OF THE HEAT ADVISORY FOR PARTS OF OUR AREA
INTO MONDAY. BUT AGAIN...THE CONFIDENCE FOR DOING IT WITH THIS
PACKAGE IS SIMPLY NOT THERE AT THIS TIME.
FOCUS THEN SHIFTS TO RAIN CHCS AND SEVERE POTENTIAL FOR EARLY NEXT
WEEK.
THE NOCTURNAL CONVECTIVE EVENT FOR AREAS NORTH OF I-70 WILL HAVE
POTENTIAL FOR SEVERE STORMS PERHAPS ALONG THE FAR NORTHERN CWA FOR A
WINDOW OF TIME THIS EVENING. SEVERE STORM POTENTIAL ON SUNDAY WILL
BE HIGHLY DEPENDENT ON EXACTLY WHAT HAPPENS THE NIGHT BEFORE BUT
ENOUGH INSTABILITY SHOULD BE PRESENT FOR AT LEAST AN ISOLATED SEVERE
STORM THREAT. MORE OR LESS THE SAME ON MONDAY WITH A NEW FRONT AND
SIMILAR INSTABILITY IN PLACE.
THE LINGERING FRONTAL BOUNDARY THRU TUESDAY WILL KEEP RAIN CHANCES
GOING. WE MAY SEE A BRIEF REPRIEVE LATE TUESDAY THRU WEDNESDAY WITH
INFLUENCE OF SURFACE HI PRESSURE BUT A WARM FRONT LATE WEDNESDAY
NIGHT INTO THURSDAY WILL ALLOW FOR THE RETURN OF RAIN CHANCES INTO
THE AREA.
ANOTHER ROUND OF HEAT REMAINS ON TAP FOR PERHAPS AS EARLY AS
THURSDAY AFTERNOON...BUT MODEL CONSENSUS AGREES TO DELAY A DAY INTO
FRIDAY AND NEXT WEEKEND.
TES
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 112 PM CDT SAT JUL 18 2015
DECAYING MCS IS KEEPING MID AND HIGH CLOUDS OVER TAF SITES THIS
AFTERNOON. DID ADD VICINITY SHOWER MENTION TO KUIN AND KCOU
THROUGH 19Z SATURDAY. OTHERWISE, NEXT CHANCE FOR ACTIVITY WILL BE
LATE TONIGHT/EARLY SUNDAY MORNING AS FRONTAL BOUNDARY APPROACHES
REGION. FRONT TO MOVE THROUGH KUIN BY 12Z SUNDAY AND THROUGH I-70
CORRIDOR TAFS BETWEEN 15Z-16Z SUNDAY WITH SOUTH WINDS VEERING TO
THE WEST WITH FRONTAL PASSAGE. MOST SITES JUST HAVE VICINITY
THUNDERSTORM MENTION IN WITH FRONT, THOUGH DID KEEP TEMPO MENTION
FOR KUIN AS THEY REMAIN IN A MORE FAVORABLE REGION FOR STORMS.
SPECIFICS FOR KSTL:
DECAYING MCS IS KEEPING MID AND HIGH CLOUDS OVER TAF SITES THIS
AFTERNOON. NEXT CHANCE FOR ACTIVITY WILL BE LATE TONIGHT/EARLY
SUNDAY MORNING AS FRONTAL BOUNDARY APPROACHES METRO AREA. FRONT
TO MOVE THROUGH METRO AREA BY 16Z SUNDAY WITH SOUTH WINDS VEERING
TO THE WEST WITH FRONTAL PASSAGE. JUST HAVE VICINITY THUNDERSTORM
MENTION IN WITH FRONT FOR NOW AS COVERAGE AND TIMING HARD TO PIN
DOWN.
BYRD
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR COLE MO-CRAWFORD MO-
FRANKLIN MO-GASCONADE MO-IRON MO-JEFFERSON MO-LINCOLN MO-
MADISON MO-MONITEAU MO-OSAGE MO-REYNOLDS MO-ST. CHARLES MO-
ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE.
GENEVIEVE MO-WARREN MO-WASHINGTON MO.
IL...HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR BOND IL-CALHOUN IL-
CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-
MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-RANDOLPH IL-
ST. CLAIR IL-WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1144 AM MDT SAT JUL 18 2015
.AVIATION...
18Z TAF CYCLE
MID LEVEL CLOUDS ACROSS WESTERN AND NORTHERN NEW MEXICO WILL
GRADUALLY THIN AS MID DAY CONVECTION STARTS TO DEVELOP.
THUNDERSTORMS AND SHOWERS TO DEVELOP A LITTLE LATER TODAY...AROUND
20Z...OVER THE WESTERN AND HIGHER TERRAIN THEN MOVE EAST
NORTHEAST. THUNDERSTORMS WILL DIMINISH IN THE EVENING WITH A
TRANSITION TO MOSTLY SHOWERS ACROSS THE NORTHWEST THIRD OF THE
FORECAST AREA. ANY THUNDERSTORM WILL BE CAPABLE OF PRODUCING MVFR
CIGS AND VISIBILITIES AND SOME OCCASIONAL MOUNTAIN OBSCURATIONS.
GRADUAL CLEARING OF ANOTHER MID LEVEL DECK EARLY ON SUNDAY. VFR
CONDITIONS EXPECTED OUTSIDE OF THUNDERSTORMS.
05
&&
.PREV DISCUSSION...1119 AM MDT SAT JUL 18 2015...
.UPDATE...
THICK CLOUD COVER WHICH WAS IN PLACE YESTERDAY HAS THINNED
TODAY...THEREFORE RAISED MOST HIGH TEMPERATURES FOR THIS
AFTERNOON. CONSEQUENTLY CONVECTION GETTING STARTED A BIT EARLIER
SO INCREASED POPS AT BIT NORTHERN MTS AND A LITTLE FARTHER EAST
INTO THE PLAINS PER LATEST RAP AND HRRR. UPDATED ZFP JUST
TRANSMITTED.
&&
.PREV DISCUSSION...331 AM MDT SAT JUL 18 2015...
.SYNOPSIS...
THE REMNANT CIRCULATION OF FORMER HURRICANE DOLORES WILL PASS WEST
THAN NORTH OF NEW MEXICO TODAY THROUGH EARLY NEXT WEEK...BUT IT
WILL STEER A RICH MONSOON MOISTURE PLUME OVER NEW MEXICO.
PRECIPITATION INTENSITY AND COVERAGE WILL INCREASE LATE TODAY AND
TONIGHT ACROSS WESTERN NEW MEXICO...THEN ALSO FARTHER EAST
SUNDAY AND MONDAY AS THE MOISTURE MOVES MORE DIRECTLY OVERHEAD.
SUNDAY NIGHT AND MONDAY A BACK DOOR COLD FRONT WILL PENETRATE
NORTHEAST AND EAST CENTRAL AREAS...HELPING TO TRIGGER
THUNDERSTORMS THERE. DRIER AIR WILL BEGIN TO MOVE INTO WESTERN
AREAS FROM THE WEST TUESDAY...BUT CENTRAL AND EASTERN AREAS SHOULD
HOLD ONTO ENOUGH MOISTURE FOR ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. TEMPERATURES THROUGH THIS
PERIOD WILL GENERALLY BE NEAR AND BELOW NORMAL...EXCEPT FOR SOME
ABOVE NORMAL READINGS ACROSS PARTS OF THE PLAINS TODAY THROUGH
SUNDAY.
&&
.DISCUSSION...
MODELS CONTINUE TO PROG A LONG WAVE TROUGH OVER THE WEST COAST
THROUGH THE EXTENDED. THE UPPER HIGH EAST OF NM WILL HELP STEER
THE RICH PLUM OF MONSOON MOISTURE OVER NM LATE SATURDAY THROUGH
TUESDAY. A SHORTWAVE TROUGH IS FORECAST TO EJECT EAST
NORTHEASTWARD ACROSS THE NORTHERN ROCKIES LATE TODAY THROUGH
SUNDAY...HELPING TO SPREAD THE MONSOON MOISTURE PLUME OVER NM AND
CO FROM AZ AND UT. THIS FIRST TROUGH WILL SEND THE AFOREMENTIONED
BACK DOOR COLD FRONT INTO THE PLAINS. MODELS HAVE BEEN CHANGING
THE TIMING OF THIS FRONT FROM RUN TO RUN...AND THERE IS SOME
UNCERTAINTY ABOUT HOW FAR IT WILL PENETRATE SOUTHWESTWARD INTO NM.
THE REMNANT CIRCULATION FROM FORMER HURRICANE DOLORES IS NOW
FORECAST TO OPEN INTO A TROUGH AND CROSS THE CENTRAL ROCKIES JUST
NORTH OF NM MONDAY NIGHT THROUGH TUESDAY NIGHT. CENTRAL AND
EASTERN AREAS COULD BE QUITE WET TUESDAY AS MOIST LOW LEVEL AIR IS
DRAWN NORTHWESTWARD INTO THE AREA AND THE MONSOON MOISTURE PLUME
IS FOCUSED BY DRIER AIR MOVING IN FROM THE WEST. LOCALLY HEAVY
RAINFALL WILL BE ESPECIALLY LIKELY TUESDAY AFTERNOON AND
EVENING...BUT THE RISK WILL FOR MINOR FLOODING WILL PROBABLY START
IN EARNEST WITH SUNDAY NIGHTS BACK DOOR COLD FRONT. SOME STRONG
TO SEVERE STORMS WILL ALSO BE POSSIBLE MONDAY AND TUESDAY.
44
&&
.FIRE WEATHER...
ABUNDANT MOISTURE ORGANIZING OVER ARIZONA WILL MOVE
EAST INTO WESTERN NEW MEXICO TODAY THEN SLIDE ACROSS CENTRAL AND
EASTERN AREAS SUNDAY THROUGH TUESDAY. HUMIDITIES WILL TREND UP EACH
DAY WHILE HIGH TEMPS REMAIN BELOW NORMAL. A MOIST BACK DOOR FRONTAL
BOUNDARY WILL FLIRT WITH THE NORTHEAST PLAINS SUNDAY AND PROVIDE AN
UPTICK IN STORM COVERAGE WITH HEAVY RAINFALL. THE FRONT WILL GET A
NUDGE TO THE SOUTHWEST SUNDAY NIGHT AND MONDAY WHILE THE MONSOON
MOISTURE PLUME SHIFTS EAST. THIS WILL PROVIDE AN EVEN BETTER SET UP
FOR LARGER FOOTPRINTS OF LOCALLY HEAVY RAINFALL FROM THE CENTRAL MT
CHAIN EAST MONDAY AND TUESDAY.
A RATHER STRONG DRY INTRUSION FOR MID JULY IS THEN ADVERTISED BY
GUIDANCE TO WORK EAST ACROSS AT LEAST WESTERN NM AS EARLY AS
TUESDAY...BUT MORE CONFIDENTLY BY WEDNESDAY. THE UPPER HIGH WILL
ALSO STRENGTHEN OVER TX AND BEGAN DRIFTING WEST TOWARD NM THROUGH
THE END OF THE WEEK. HUMIDITIES ARE EXPECTED TO TREND DOWN WHILE MAX
TEMPS RETURN TO NEAR NORMAL. MANY AREAS MAY SEE MIN RH FALL TO BTWN
15 AND 20 PCT WEDNESDAY AND THURSDAY WITH ONLY ISOLATED STORMS ON
TAP FOR THE HIGH TERRAIN. WHATEVER STORMS DO FORM MAY STILL DROP
DECENT RAINFALL WITH VERY WEAK STORM MOTION.
CONFIDENCE BEYOND THURSDAY IS LOW WITH GUIDANCE INCONSISTENT ON HOW
THE UPPER LEVEL HIGH AND MOISTURE PATTERN EVOLVE. NONETHELESS...NO
SIGNIFICANT BURSTS OF WIDESPREAD HEAVY RAIN APPEAR IN THE EXTENDED
RANGE FOR NOW.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1119 AM MDT SAT JUL 18 2015
.UPDATE...
THICK CLOUD COVER WHICH WAS IN PLACE YESTERDAY HAS THINNED
TODAY...THEREFORE RAISED MOST HIGH TEMPERATURES FOR THIS
AFTERNOON. CONSEQUENTLY CONVECTION GETTING STARTED A BIT EARLIER
SO INCREASED POPS AT BIT NORTHERN MTS AND A LITTLE FARTHER EAST
INTO THE PLAINS PER LATEST RAP AND HRRR. UPDATED ZFP JUST
TRANSMITTED.
&&
.PREV DISCUSSION...546 AM MDT SAT JUL 18 2015...
.AVIATION...
12Z TAF CYCLE
THE CURRENT MID LEVEL DECK OVER NORTHERN/WESTERN NM WILL GIVE WAY
TO -SHRA/TSRA BY LATE DAY AT TERMINALS. RECENT DAYS SUGGEST TIMING
OF IMPACTS AT TAF SITES ON LATER SIDE DUE TO ABUNDANT CLOUD COVER
AND BELOW NORMAL TEMPS. DEVELOPMENT WILL OCCUR NEAR 20-21Z ON THE
HIGH TERRAIN THEN SPAWN ACTIVITY ON OUTFLOW BOUNDARIES INTO LOWER
TERRAIN AREAS. FOCUSED TARGET WINDOW AFT 22Z ALONG AND WEST OF THE
CONT DVD AND NEAR THE SANGRE DE CRISTOS...THEN AFT 00Z FOR CENTRAL
NM AND RIO GRANDE VALLEY. SHRA IN THE EVENING WILL TAPER TO BROKEN
CIGS THRU THE OVERNIGHT. STORM MOTIONS WILL BE E/NE NEAR 10 KTS.
GUYER
&&
.PREV DISCUSSION...331 AM MDT SAT JUL 18 2015...
.SYNOPSIS...
THE REMNANT CIRCULATION OF FORMER HURRICANE DOLORES WILL PASS WEST
THAN NORTH OF NEW MEXICO TODAY THROUGH EARLY NEXT WEEK...BUT IT
WILL STEER A RICH MONSOON MOISTURE PLUME OVER NEW MEXICO.
PRECIPITATION INTENSITY AND COVERAGE WILL INCREASE LATE TODAY AND
TONIGHT ACROSS WESTERN NEW MEXICO...THEN ALSO FARTHER EAST
SUNDAY AND MONDAY AS THE MOISTURE MOVES MORE DIRECTLY OVERHEAD.
SUNDAY NIGHT AND MONDAY A BACK DOOR COLD FRONT WILL PENETRATE
NORTHEAST AND EAST CENTRAL AREAS...HELPING TO TRIGGER
THUNDERSTORMS THERE. DRIER AIR WILL BEGIN TO MOVE INTO WESTERN
AREAS FROM THE WEST TUESDAY...BUT CENTRAL AND EASTERN AREAS SHOULD
HOLD ONTO ENOUGH MOISTURE FOR ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. TEMPERATURES THROUGH THIS
PERIOD WILL GENERALLY BE NEAR AND BELOW NORMAL...EXCEPT FOR SOME
ABOVE NORMAL READINGS ACROSS PARTS OF THE PLAINS TODAY THROUGH
SUNDAY.
&&
.DISCUSSION...
MODELS CONTINUE TO PROG A LONG WAVE TROUGH OVER THE WEST COAST
THROUGH THE EXTENDED. THE UPPER HIGH EAST OF NM WILL HELP STEER
THE RICH PLUM OF MONSOON MOISTURE OVER NM LATE SATURDAY THROUGH
TUESDAY. A SHORTWAVE TROUGH IS FORECAST TO EJECT EAST
NORTHEASTWARD ACROSS THE NORTHERN ROCKIES LATE TODAY THROUGH
SUNDAY...HELPING TO SPREAD THE MONSOON MOISTURE PLUME OVER NM AND
CO FROM AZ AND UT. THIS FIRST TROUGH WILL SEND THE AFOREMENTIONED
BACK DOOR COLD FRONT INTO THE PLAINS. MODELS HAVE BEEN CHANGING
THE TIMING OF THIS FRONT FROM RUN TO RUN...AND THERE IS SOME
UNCERTAINTY ABOUT HOW FAR IT WILL PENETRATE SOUTHWESTWARD INTO NM.
THE REMNANT CIRCULATION FROM FORMER HURRICANE DOLORES IS NOW
FORECAST TO OPEN INTO A TROUGH AND CROSS THE CENTRAL ROCKIES JUST
NORTH OF NM MONDAY NIGHT THROUGH TUESDAY NIGHT. CENTRAL AND
EASTERN AREAS COULD BE QUITE WET TUESDAY AS MOIST LOW LEVEL AIR IS
DRAWN NORTHWESTWARD INTO THE AREA AND THE MONSOON MOISTURE PLUME
IS FOCUSED BY DRIER AIR MOVING IN FROM THE WEST. LOCALLY HEAVY
RAINFALL WILL BE ESPECIALLY LIKELY TUESDAY AFTERNOON AND
EVENING...BUT THE RISK WILL FOR MINOR FLOODING WILL PROBABLY START
IN EARNEST WITH SUNDAY NIGHTS BACK DOOR COLD FRONT. SOME STRONG
TO SEVERE STORMS WILL ALSO BE POSSIBLE MONDAY AND TUESDAY.
44
&&
.FIRE WEATHER...
ABUNDANT MOISTURE ORGANIZING OVER ARIZONA WILL MOVE
EAST INTO WESTERN NEW MEXICO TODAY THEN SLIDE ACROSS CENTRAL AND
EASTERN AREAS SUNDAY THROUGH TUESDAY. HUMIDITIES WILL TREND UP EACH
DAY WHILE HIGH TEMPS REMAIN BELOW NORMAL. A MOIST BACK DOOR FRONTAL
BOUNDARY WILL FLIRT WITH THE NORTHEAST PLAINS SUNDAY AND PROVIDE AN
UPTICK IN STORM COVERAGE WITH HEAVY RAINFALL. THE FRONT WILL GET A
NUDGE TO THE SOUTHWEST SUNDAY NIGHT AND MONDAY WHILE THE MONSOON
MOISTURE PLUME SHIFTS EAST. THIS WILL PROVIDE AN EVEN BETTER SET UP
FOR LARGER FOOTPRINTS OF LOCALLY HEAVY RAINFALL FROM THE CENTRAL MT
CHAIN EAST MONDAY AND TUESDAY.
A RATHER STRONG DRY INTRUSION FOR MID JULY IS THEN ADVERTISED BY
GUIDANCE TO WORK EAST ACROSS AT LEAST WESTERN NM AS EARLY AS
TUESDAY...BUT MORE CONFIDENTLY BY WEDNESDAY. THE UPPER HIGH WILL
ALSO STRENGTHEN OVER TX AND BEGAN DRIFTING WEST TOWARD NM THROUGH
THE END OF THE WEEK. HUMIDITIES ARE EXPECTED TO TREND DOWN WHILE MAX
TEMPS RETURN TO NEAR NORMAL. MANY AREAS MAY SEE MIN RH FALL TO BTWN
15 AND 20 PCT WEDNESDAY AND THURSDAY WITH ONLY ISOLATED STORMS ON
TAP FOR THE HIGH TERRAIN. WHATEVER STORMS DO FORM MAY STILL DROP
DECENT RAINFALL WITH VERY WEAK STORM MOTION.
CONFIDENCE BEYOND THURSDAY IS LOW WITH GUIDANCE INCONSISTENT ON HOW
THE UPPER LEVEL HIGH AND MOISTURE PATTERN EVOLVE. NONETHELESS...NO
SIGNIFICANT BURSTS OF WIDESPREAD HEAVY RAIN APPEAR IN THE EXTENDED
RANGE FOR NOW.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
331 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP INTO
THIS EVENING WITH THE HIGHEST CHANCES ACROSS NORTHEAST
PENNSYLVANIA AND THE CATSKILLS. AFTER THE THUNDERSTORMS DIE DOWN
LATE THIS EVENING A VERY HUMID AND WARM AIR MASS WILL BE IN
PLACE. HIGHS SUNDAY WILL TOP 90 DEGREES IN MANY AREAS WITH HEAT
INDICES IN THE MID TO UPPER 90S DUE TO THE HIGH HUMIDITY. THE
INCREASE IN HEAT AND HUMIDITY ALONG WITH A COLD FRONT COULD PRODUCE
SEVERE THUNDERSTORMS LATER SUNDAY AFTERNOON AND NIGHT. MORE
COMFORTABLE AIR RETURNS TO THE AREA BY EARLY NEXT WEEK AFTER THIS COLD
FRONT PASSES EAST OF THE REGION.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADAR SHOWS ISOLATED SHRA AND TSRA ACROSS CENTRAL NEW YORK. THE
CONVECTION WAS VERY LIMITED IN SCOPE WITH VERY LITTLE COVERAGE.
THE 7.4 MICRON IMAGERY CONTINUES TO SHOW SIGNIFICANT DARKENING IN
NY/PA SUGGESTING MID-LEVEL SUBSDC BEHIND THE SHORT WAVE THAT WAS
PASSING TO OUR EAST. THIS SUBSDC WAS FIGHTING THE CONVECTIVE
HEATING AND UPDRAFTS AS MIXED LAYER CAPES WERE OVER2000 J/KG IN AS
LARGE PART OF C NY AND NE PA. ONCE THIS VERY DARK PATCH PASSES E
OF THE REGION LATER THIS AFTERNOON THE SUBSC WILL LESSEN AND
BELIEVE ACVTY WILL INCREASE IN COVERAGE TO SCT IN NE PA/SC NY AND
REMAIN JUST ISOLATED IN THE NORTH PART OF CENTRAL NY. THIS ACVTY
DOES HAVE A LOT OF CAPE TO WORK WITH...BUT A SIGNIFICANT AMOUNT OF
DRY AIR AT MID TO UPPER LEVELS ALSO WAS HAMPERING DEVELOPMENT PLUS LACK
OF STRG FORCING. HENCE WE DON/T BELIEVE THERE WILL BE ANY
ORGANIZATION AND WE WILL HAVE POPS FROM SLGHT CHC TO CHC WITH THE
HIGHEST CHC IN NE PA/CATSKILLS AND LEAST CHC IN OUR LAKE ONTARIO
PLAIN COUNTIES. WE ARE NOT EXPECTING ANY SEVERE WEATHER WITH THIS
ACVTY. SINCE THE PRESENT ACVTY WAS DIURNALLY DRIVEN IT SHUD
WEAKEN AFTER SUNSET.
THEN SCT SHRA AND TSRA CUD ARRIVE AGAIN BTWN 9Z-12Z SUN OR SO AS
REMNANTS OF CONVECTIVE ACVTY OVER LOWER MICHIGAN ARE PROGGED TO
REACH C NY AS PER RAP AND HRRR. OTHER MODELS HINTS AT THIS TOO. IF
ANY ACVTY REACHES C NY IT WILL WEAKEN AFTER SUNRISE. HAVE SOME
POPS FOR THIS ACVTY AS WELL.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
OUR ATTENTION TURNS TO A POTENTIAL SEVERE WEATHER OUTBREAK FOR
SUNDAY AFTERNOON/NIGHT. THE EURO...GFS...NAM...CMC AS WELL AS
HIGHER RESOLUTION MODELS ALL INDICATE SIGNIFICANT INSTABILITY
DEVELOPING SUNDAY AFTERNOON WITH THE PROJECTED HEAT AND HUMIDITY.
CAPES ON THE HI RES MODELS RANGE FROM 2000-4000 J/KG...LI/S ON
THE EURO ARE BETWEEN -8C AND -10C AT 00Z MON...THE GEM GETS DOWN
TO -8C LI. THIS INSTABILITY OCCURS AS A STRG UPR LVL JET MAX MOVES
INTO THE EASTERN GREAT LAKES BY 00Z MON AND PUSHES A COLD FRONT
INTO THIS AREA AS WELL. AS A RESULT...SHEAR PROFILES LOOK
IMPRESSIVE LATE IN THE DAY AS THIS MID TO UPPER LEVEL WIND MAX
ARRIVES. THIS WHOLE SHORT WAVE WAS RIDING E-SE TWD NY AND PA SUN
PM OVER THE UPPER LEVEL RDG WHICH IS RETROGRADING TO THE SC U.S.
THIS IS A CLASSIC NW FLOW SEVERE WEATHER PATTERN FOR OUR AREA.
GIVEN THE RESULTANT SHEAR PROFILES OF ARND 20 KNOTS 0-1 KM BULK
SHEAR...30-35 KNOTS 0-3 KM AND POTENTIALLY UP TO 50 KNOTS 0-6
KM SHEAR...WE CUD BE LOOKING AT AN EVENT WHERE SUPERCELLS FORM IN
THE EASTERN LAKES WHICH MERGE INTO A SQUALL LINE/DERECHO BY THE
TIME IT REACHES C NY AND NE PA SUN EVE. OUR LOCAL SEVERE WEATHER
CHECKLIST RETURNS A COUPLE OF OUR BIGGER DERECHO EVENTS. CONCUR
WITH SPC EXPANDING SLGHT RISK TO COVER OUR WHOLE AREA LATER SUNDAY
AND SUNDAY NIGHT AND WOULDN`T BE SURPRISED TO SEE THIS UPGRADED
FURTHER IF THE ABOVE MENTIONED PARAMETERS PERSIST ON THE LATER
MODEL RUNS.
IN ADDTN...GIVEN HOW WET IT HAS BEEN LATELY AND THE TROPICAL
CONNECTION THAT THIS NEXT WAVE HAS AS POINTED OUT BY WFO
BUFFALO...IF RAIN RATES ARE HEAVY ENOUGH THERE CUD BE SOME
LOCALIZED FLASH FLOODING. IT IS POSSIBLE THAT THE STORMS ARE
MOVING TOO FAST TO PRECLUDE MAJOR FLASH FLOODING SO JUST MENTIONED
FLASH FLOOD POTENTIAL IN HWO FOR NOW. ALSO MENTIONED POTENTIAL
FOR A SEVERE WEATHER OUTBREAK IN HWO.
LASTLY HEAT INDICES WILL RANGE IN THE MID TO UPPER 90S MOST AREAS
SUNDAY WHICH FALLS SHORT OF OUR HEAT ADVY CRITERIA OF 100F. WE
KEPT MENTION OF HEAT IN HWO FOR GOOD MEASURE.
WE EXPECT ANY ORGANIZED THUNDERSTORMS TO EXIT THE FORECAST AREA
LATE SUNDAY NIGHT WITH WEAK HIGH PRESSURE AND FAIR AND COOLER
WEATEHR FOR MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
230 PM UPDATE...
MONDAY NIGHT A WEAK RIDGE OF HIGH PRESSURE MOVES IN. MODELS BRING
IN A MODERATE STRENGTH SYSTEM WITH A SFC COLD FRONT AND UPPER
LEVEL TROF TUESDAY. MIDDAY FROPA NOT THE BEST FOR HEATING TO HELP
THE INSTABILITY. TIMING HAS CHANGED ON THIS AND STILL SEVERAL DAYS
OUT SO IT COULD CHANGE AGAIN.
FOLLOWED WPC GUIDANCE TUES NGT ON. BIGGEST CHANGE WAS TO LOWER
TEMPS SEVERAL DEGREES. SO NOW TEMPERATURES AT OR SLIGHTLY BELOW
NORMAL. EURO HAS A DEEPER TROF THAT LASTS LONGER.
SHOWERS MOVE OUT TUESDAY EVENING THEN HIGH PRESSURE BUILDS IN THU
AND LASTS INTO SATURDAY. CANADIAN AND EURO SIMILAR BUT GFS HAS
WEAK SYSTEMS MOVING THROUGH THE AREA THE ENTIRE WEEK.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
130 PM UPDATE...
MAINLY VFR INTO MIDDAY SUNDAY.
UP TO 20Z SOME SHOWERS ITH/BGM COULD CAUSE PERIODS OF MVFR CIGS
AND MAYBE VSBY. THESE SHOWERS SHOULD GET INTO AVP 20 TO 23Z WITH
SIMILAR RESULTS.
CLOUDS SHOULD DIMINISH THIS EVE WITH THE LOSS OF HEATING. WINDS
WILL GO LIGHT SO ELM COULD AGAIN HAVE IFR CONDITIONS NEAR FLIGHT
MINIMUMS 9 TO 12Z. BGM/AVP/ITH SHOULD FALL TO MVFR VSBYS WITH THE
SATURATED LOW LEVELS AND THE RAIN TODAY.
SUNDAY CONVECTION SHOULD START AFTER 18Z. LATE TONIGHT TO SUNDAY
MORNING SOME CONVECTIVE DEBRIS MAKE IT INTO THE THE AREA
ESPECIALLY THE NORTH.
SW WINDS SOUTH AND NW WINDS NORTH AT 10 KTS DROP TO LIGHT AND
VARIABLE OR CALM THIS EVENING AND LAST INTO SUNDAY MORNING. SUNDAY
AFTER 14Z SW WINDS AT 5 TO 10 KTS.
.OUTLOOK...
SUN AFTN THRU TUE...A FEW RESTRICTIONS FROM SCT SHRA-
TSRA...ESPECIALLY WITH FRONTAL PASSAGE LATE SUN AND AGAIN TUE.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
250 PM EDT SAT JUL 18 2015
.SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON,
WITH THE HIGHEST CHANCES ACROSS NORTHEAST PENNSYLVANIA AND THE
CATSKILLS. AFTER THE THUNDERSTORMS DIE DOWN THIS EVENING A VERY
HUMID AND WARM AIR MASS WILL BE IN PLACE. HIGHS SUNDAY WILL TOP 90
DEGREES IN MANY AREAS WITH HEAT INDICES APPROACHING 100 DEGREES
DUE TO THE HIGH HUMIDITY. THE INCREASE IN HEAT AND HUMIDITY ALONG
WITH A COLD FRONT MAY PRODUCE STRONG STORMS SUNDAY AFTERNOON AND
NIGHT. MORE COMFORTABLE AIR RETURNS TO THE AREA BY EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST KBGM RADAR SHOWS JUST A FEW ISOLATED SHRA IN PARTS OF THE
WESTERN CATSKILLS AND EXTREME NE PA AT THIS TIME WITH A FEW
SHRA/TSRA IN THE ALLEGHENIES OF WRN NY AND NC PA. LARGE SCALE
MOSAIC RADAR IMAGERY SHOWS AN MCS MOVING ACRS LAKE MICHIGAN AND
LWR MICHIGAN. THE HRRR...WRF_ARW...WRF_NMM...RAP AND NAM ALL SHOW
THAT THIS MCS WILL DIVE SE AND FALL APART AS DIURNAL HEATING
KICKS IN AND DISRUPTS THE INFLOW INTO THIS FEATURE. MODELS ALSO
SHOW ANOTHER SHORT WAVE PASSING ACRS NY AND PA THIS AFTERNOON
WHICH COULD BE CONVECTIVELY INDUCED BY THIS MCS. IN ADDTN...MODEL
MIXED LAYER CAPES THIS AFTERNOON VARY FROM 3000 TO 4000 J/KG ON
THE LATEST NAM...TO 2000-3000 J/KG ON THE WRF_NMM....TO 1000 TO
2000 J/KG ON THE HRRR AND WRF_ARW. THE GFS HAS AROUND 1000 J/KG.
VISIBLE SATELLITE IMAGERY ALSO SHOWS BREAKS AND DESTABILIZATION
BEGINNING TO TAKE PLACE. THE WATER VAPOR AND 7.4 MICRON IMAGERY
SHOWS A LOT OF DRY AIR ADVECTING OVER NY AND PA AS WELL LATE THIS
MORNING WITH STRG MID-LVL SUBSDC AT PRESENT. AS THIS SMALL SHORT
WAVE WORKS E THIS AFTERNOON THERE WILL BE SOME ASCENT AND ALL HI
RES CONVECTION ALLOWING MODELS POP MOST OF THE CONVECTION AS PER
MODEL RADAR IMAGERY FROM SC NY TO NE PA. SO HAVE HIGHEST POPS THIS
AFTERNOON INTO EARLY EVENING IN NE PA/SERN NY AND LEAST (SLGHT CHC
TO LO CHC) ON THE LAKE ONTARIO PLAIN.
THE 0-1, 0-3 AND 0-6 KM BULK SHEARS ARE NOT THAT IMPRESSIVE THIS
AFTERNOON RUNNING 15 KNOTS, 20 KNOTS AND 20 KNOTS RESPECTIVELY.
BUT GIVEN CAPES THERE CUD BE A FEW ISOLATED SVR STORMS WITH LARGE
HAIL AND MICROBURST WINDS GIVEN THE DRIER AIR ALOFT. SO WILL CONT
TO MENTION IN HWO FOR THIS AFTERNOON AND EVENING AND FOCUS ON NE
PA TO THE WRN CATSKILLS AND CONCUR WITH SPC MARGINAL RISK.
AFTER CONVECTION DIES DOWN THIS EVENING...WE HAVE SKIES CLEARING
WITH PATCHY FOG DEVELOPING LATE. HOWEVER LATEST RAP SUGGESTS MORE
CONVECTION LATE TONIGHT. OTHER 12Z MODELS SO FAR DO NOT. FOR NOW
WILL KEEP LATE TONIGHT DRY. BUT WILL HAVE TO REASSESS AS MORE
GUIDC COMES IN.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
430 AM UPDATE...
HOT AND HUMID, JUST LIKE SUMMER SHOULD BE. THAT SUMS UP SUNDAY.
DID LITTLE WITH TEMPS, WITH MOST OF THE LOWER ELEVATIONS IN THE
90-92 RANGE, AND ELEVATIONS 84 TO 88. WITH DEWPOINTS NEAR 70, HEAT
INDICES WILL BE IN THE MID TO UPPER 90S, WITH NEAR 100 POSSIBLE IN
THE METRO AREAS OF CNY AND NEPA. EXCELLENT HWO FROM YESTERDAY WAS
KEPT IN TACT FOR THE HEAT THREAT. IN ADDITION FROM JUST 24 HOURS
AGO, THREAT FOR STORMS LATER SUNDAY LOOKS A BIT HIGHER. BEST SHEAR
STILL LOOKS TO BE LATER SUNDAY NIGHT BUT WE SHOULD HAVE MORE OF A
TRIGGER SUNDAY AFTERNOON AND CAPES AGAIN AVERAGE 1000 TO 2000
J/KG.
BOTH THE EURO AND GFS CLEAR US OUT PRETTY QUICKLY MONDAY SO
BESIDES AN EARLY SHOWER, I CLEARED POPS FROM MONDAY AFTERNOON AS
COMFORTABLE AIR SETTLES IN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
230 PM UPDATE...
MONDAY NIGHT A WEAK RIDGE OF HIGH PRESSURE MOVES IN. MODELS BRING
IN A MODERATE STRENGTH SYSTEM WITH A SFC COLD FRONT AND UPPER
LEVEL TROF TUESDAY. MIDDAY FROPA NOT THE BEST FOR HEATING TO HELP
THE INSTABILITY. TIMING HAS CHANGED ON THIS AND STILL SEVERAL DAYS
OUT SO IT COULD CHANGE AGAIN.
FOLLOWED WPC GUIDANCE TUES NGT ON. BIGGEST CHANGE WAS TO LOWER
TEMPS SEVERAL DEGREES. SO NOW TEMPERATURES AT OR SLIGHTLY BELOW
NORMAL. EURO HAS A DEEPER TROF THAT LASTS LONGER.
SHOWERS MOVE OUT TUESDAY EVENING THEN HIGH PRESSURE BUILDS IN THU
AND LASTS INTO SATURDAY. CANADIAN AND EURO SIMILAR BUT GFS HAS
WEAK SYSTEMS MOVING THROUGH THE AREA THE ENTIRE WEEK.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
130 PM UPDATE...
MAINLY VFR INTO MIDDAY SUNDAY.
UP TO 20Z SOME SHOWERS ITH/BGM COULD CAUSE PERIODS OF MVFR CIGS
AND MAYBE VSBY. THESE SHOWERS SHOULD GET INTO AVP 20 TO 23Z WITH
SIMILAR RESULTS.
CLOUDS SHOULD DIMINISH THIS EVE WITH THE LOSS OF HEATING. WINDS
WILL GO LIGHT SO ELM COULD AGAIN HAVE IFR CONDITIONS NEAR FLIGHT
MINIMUMS 9 TO 12Z. BGM/AVP/ITH SHOULD FALL TO MVFR VSBYS WITH THE
SATURATED LOW LEVELS AND THE RAIN TODAY.
SUNDAY CONVECTION SHOULD START AFTER 18Z. LATE TONIGHT TO SUNDAY
MORNING SOME CONVECTIVE DEBRIS MAKE IT INTO THE THE AREA
ESPECIALLY THE NORTH.
SW WINDS SOUTH AND NW WINDS NORTH AT 10 KTS DROP TO LIGHT AND
VARIABLE OR CALM THIS EVENING AND LAST INTO SUNDAY MORNING. SUNDAY
AFTER 14Z SW WINDS AT 5 TO 10 KTS.
.OUTLOOK...
SUN AFTN THRU TUE...A FEW RESTRICTIONS FROM SCT SHRA-
TSRA...ESPECIALLY WITH FRONTAL PASSAGE LATE SUN AND AGAIN TUE.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/HEDEN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 PM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1015 AM SATURDAY...
EARLIER COMPLEX OF SHOWERS MOVING INTO THE TRIAD HAS ALL BUT
DIMINISHED THIS HOUR WITH A BAD OF CLOUDS REMAINING FROM THE
FOOTHILLS...JUST NOW MOVING INTO THE NW PIEDMONT. NOT A LOT OF
ENHANCEMENT ON THE VISIBLE PICTURE AT THIS TIME AND THE HRRR HAS
BACKED OFF ON ALL PRECIPITATION UNTIL AROUND 17Z WHEN TEMPERATURES
RISE ENOUGH TO START GETTING CONVECTIVE INITIATION ACROSS THE AREA.
CONVECTION SHOULD BEGIN AS SCATTERED SHOWERS ACROSS MUCH OF THE CWA
BUT THEN A PUSH FROM A SHORTWAVE ENTERING THE TRIAD AFTER 18Z COULD
BEGIN TO ORGANIZE STORMS A LITTLE MORE. WITH BULK SHEAR VALUES IN
THE 20-25 KT RANGE AND INSTABILITY BETWEEN 1000-1500 J/KG WOULD
EXPECT SOME KIND OF LINEAR MULTICELLULAR FEATURE WHICH WILL WORK
THROUGH THE CWA FROM NW TO SE THIS AFTERNOON AND INTO THE EARLY
EVENING HOURS. EXPECT THE BEST UPPER LEVEL SUPPORT FROM 500 MB
VORTICITY TO MOVE THROUGH THE TRIANGLE AREA MID AFTERNOON AND THE I-
95 CORRIDOR BY EARLY EVENING. SPC CURRENTLY HAS THE AREA UNDER A
MARGINAL RISK FOR ANY SEVERE STORMS WITH DAMAGING WINDS THE PRIMARY
THREAT. ANY SEVERE ACTIVITY THIS AFTERNOON SHOULD REMAIN ISOLATED.
PREVIOUS DISCUSSION FOLLOWS. -ELLIS
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA. -BSD
&&
.SHORT TERM /SUNDAY NIGHT/...
AS OF 300 AM SATURDAY...
TO BE UPDATED SHORTLY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 310 PM SATURDAY...
MON: HOT WITH LOWER-THAN-USUAL (FOR SUMMERTIME) STORM CHANCES. WE
REMAIN BENEATH NORTHWESTERLY STEERING FLOW... ON THE NE SIDE OF THE
SPRAWLING RIDGE FROM NW MEXICO ACROSS TX AND THE LOWER MISS
VALLEY... BUT THIS FLOW IS VERY LIGHT OVER NC WITH THE STRONGER MID
LEVEL WINDS AND DIFFLUENCE WELL TO OUR NW. A PROMINENT PERTURBATION
CROSSING KS/NRN/MO/IL/OH VALLEY INTO MON EVENING MAY HELP BUILD
SHORTWAVE RIDGING DOWNSTREAM OVER NC MUCH OF THE DAY... AND
ACCORDINGLY THE MODELS ARE FORECASTING LITTLE POTENTIAL BUOYANCY
WITH NC MUCAPE VALUES GENERALLY BELOW 1000 J/KG EVEN AT PEAK
HEATING... ALONG WITH SUB-20 KT DEEP LAYER SHEAR... AND A WARM 500-
300 MB LAYER. A WEAK SURFACE TROUGH WILL HOLD OVER THE COASTAL
PLAIN... AND THIS AREA WITH ITS HIGHER SURFACE DEWPOINTS MAY SEE A
BIT BETTER CHANCE FOR AFTERNOON CONVECTION... BUT STILL MEAGER GIVEN
THE LACK OF STRONG DYNAMIC OR THERMODYNAMIC SUPPORT. ANYTHING THAT
CAN GET GOING MAY GENERATE ENHANCED DOWNDRAFTS GIVEN THE INVERTED-V
FORECAST SOUNDING APPEARANCE AND DCAPE NEARING 1000 J/KG. WILL KEEP
POPS LOW AT 15-30% AT MOST... HIGHEST EAST OF I-95. OUR LOW LEVEL
THICKNESSES SHOULD BE WELL ABOVE NORMAL (BY 15-20 M)... WITH THE MID
LEVEL ANTICYCLONE CENTERED IN THE CLIMATOLOGICALLY IDEAL LOCATION
FOR ATYPICALLY HOT TEMPS IN NC. FOLLOWING THIS AND WITH THE WARMING
TREND OF GUIDANCE... EXPECT HIGHS OF 95-100... A FEW DEGREES SHY OF
THE DAILY RECORD HIGHS. HEAT INDICES COULD REACH 103-104 DEGREES
MAINLY IN THE SOUTHEAST... ALTHOUGH IF DEWPOINTS DON`T SLIP INTO THE
UPPER 60S WITH MIXING... READINGS COULD HIT 105 BRIEFLY. WE MAY SEE
ISOLATED DYING SHOWERS SPILLING OVER FROM THE HIGHER TERRAIN MON
NIGHT. WARM LOWS OF 71-76.
TUE: CONTINUE HOT WITH BETTER STORM CHANCES THAN MON. STILL
ANTICIPATE ABOVE NORMAL TEMPS BUT WILL PROBABLY BE MUTED FROM
MONDAY`S READINGS BY UPSTREAM CONVECTIVE DEBRIS CLOUDS MOVING
OVERHEAD... TRIMMING HEATING A BIT... SO EXPECT TUE HIGHS TO BE A
DEGREE OR TWO LOWER THAN MONDAY`S... DESPITE THICKNESSES COMPARABLE
TO THOSE EXPECTED MONDAY. HEAT INDICES SHOULD ONCE AGAIN APPROACH
103-104 DEGREES IN THE SOUTHEAST. PROJECTED MUCAPE TUE IS STILL
UNIMPRESSIVE... JUST 750-1500 J/KG... WITH MEAGER DEEP LAYER SHEAR
OF AROUND 20 KTS. BUT DYNAMIC FORCING WILL BE ON THE UPSWING AS THE
MID LEVEL LOW OVER QUEBEC DIGS ACROSS THE GREAT LAKES AND
NORTHEAST... PROVIDING SLIGHT DPVA AND HEIGHT FALLS ESPECIALLY LATE
TUE THROUGH TUE NIGHT... IN CONJUNCTION WITH THE SURFACE COLD FRONT
PUSHING IN FROM THE NW. WILL TOP OUT POPS AT 30-40%... ALTHOUGH THIS
MAY RISE IN LATER FORECASTS IF TIMING CAN BE PINNED DOWN.
WED-SAT: MOST OF THE AREA (EXCEPT FOR SE SECTIONS) WILL BE IN A
RELATIVE LULL CONVECTION-WISE AS THE SURFACE FRONT IS EXPECTED TO
SETTLE OVER SRN/ERN NC WITH HIGH PRESSURE STARTING TO BUILD IN FROM
THE NW. WILL KEEP GOOD CHANCE POPS ACROSS THE SOUTH AND EAST WED
WHERE PW VALUES WILL BE NEAR TO ABOVE NORMAL... HOWEVER DRIER AIR
ELSEWHERE SHOULD LIMIT STORM COVERAGE OVER THE NORTH AND WEST WED.
CONVECTION CHANCES LOOK TO RISE THU AND PEAK FRI... AS STRONG
SHORTWAVE ENERGY MOVES ESE INTO THE MIDATLANTIC REGION... INTO THE
MEAN TROUGH BASE... WITH A NORTHWARD SURGE OF THE SURFACE FRONTAL
ZONE. THE INITIALLY LOWER PW VALUES CLIMB BACK UP CLOSE TO 2.0
INCHES ESPECIALLY IN THE SOUTH HALF FRI... AND THIS IS WHERE THE
GREATEST COVERAGE SHOULD BE. THE MID LEVEL TROUGH AXIS AND SURFACE
FRONT SHOULD THEN SETTLE SOUTHEAST OF THE NC... USHERING IN A
SLIGHTLY DRIER AIR MASS TO START THE WEEKEND. THICKNESSES SUGGEST
CONTINUED ABOVE NORMAL TEMPS WED... A COUPLE OF DEGREES COOLER BUT
STILL SLIGHTLY ABOVE NORMAL THU... THEN NEAR NORMAL FRI/SAT. -GIH
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 200 PM SATURDAY...
24 HOUR TAF PERIOD: A LINE OF CONVECTION IS MOVING OVER KRDU AT THIS
TIME AND WILL BE APPROACHING KRWI IN THE NEXT FEW HOURS IF IT HOLDS
TOGETHER. TO THE SOUTH...MORE SCATTERED THUNDERSTORMS WILL APPROACH
THE VICINITY OF KFAY BY 20Z OR SO. WIND GUSTS OF 40-50 KTS ARE
POSSIBLE WITH THESE STORMS BUT THE MAJORITY OF CONVECTION WILL SEE
WIND GUSTS REMAIN UNDER 30 KTS. BEHIND THE LINE...WINDS ARE EXPECTED
TO BRIEFLY GO NORTHWESTERLY BEFORE RETURNING TO A GENERAL
SOUTHEASTERLY FLOW. OVERNIGHT...SOME VFR VISIBILITIES ARE POSSIBLE
AROUND DAYBREAK. WITH NO DISCERNIBLE SHORT WAVE IN THE
AREA...CONVECTIVE COVERAGE SUNDAY AFTERNOON SHOULD BE LESS THAN THIS
AFTERNOON.
LONG TERM: WITH A RETURN TO SOUTHERLY FLOW...EXPECT AN UPTICK IN
DIURNAL COVERAGE OF SHOWERS AND THUNDERSTORMS BEGINNING SATURDAY
AFTERNOON/EVENING AND CONTINUING THROUGH THE END OF THE LONG TERM
WHICH COULD PRESENT SOME ADVERSE CONDITIONS EACH DAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...ELLIS/BSD
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
217 PM EDT SAT JUL 18 2015
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE AREA TODAY AND
REMAIN ACROSS THE REGION INTO NEXT WEEK. AN UPPER LEVEL DISTURBANCE
WILL TRACK SOUTHEASTWARD FROM FROM THE OHIO VALLEY THIS MORNING AND
ACROSS CENTRAL NC THIS AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1015 AM SATURDAY...
EARLIER COMPLEX OF SHOWERS MOVING INTO THE TRIAD HAS ALL BUT
DIMINISHED THIS HOUR WITH A BAD OF CLOUDS REMAINING FROM THE
FOOTHILLS...JUST NOW MOVING INTO THE NW PIEDMONT. NOT A LOT OF
ENHANCEMENT ON THE VISIBLE PICTURE AT THIS TIME AND THE HRRR HAS
BACKED OFF ON ALL PRECIPITATION UNTIL AROUND 17Z WHEN TEMPERATURES
RISE ENOUGH TO START GETTING CONVECTIVE INITIATION ACROSS THE AREA.
CONVECTION SHOULD BEGIN AS SCATTERED SHOWERS ACROSS MUCH OF THE CWA
BUT THEN A PUSH FROM A SHORTWAVE ENTERING THE TRIAD AFTER 18Z COULD
BEGIN TO ORGANIZE STORMS A LITTLE MORE. WITH BULK SHEAR VALUES IN
THE 20-25 KT RANGE AND INSTABILITY BETWEEN 1000-1500 J/KG WOULD
EXPECT SOME KIND OF LINEAR MULTICELLULAR FEATURE WHICH WILL WORK
THROUGH THE CWA FROM NW TO SE THIS AFTERNOON AND INTO THE EARLY
EVENING HOURS. EXPECT THE BEST UPPER LEVEL SUPPORT FROM 500 MB
VORTICITY TO MOVE THROUGH THE TRIANGLE AREA MID AFTERNOON AND THE I-
95 CORRIDOR BY EARLY EVENING. SPC CURRENTLY HAS THE AREA UNDER A
MARGINAL RISK FOR ANY SEVERE STORMS WITH DAMAGING WINDS THE PRIMARY
THREAT. ANY SEVERE ACTIVITY THIS AFTERNOON SHOULD REMAIN ISOLATED.
PREVIOUS DISCUSSION FOLLOWS. -ELLIS
HIGH TEMPS TODAY ARE EXPECTED TO BE LARGELY DEPENDENT ON THE AMOUNT
OF DEBRIS CLOUD COVER FROM THE APPROACHING CONVECTIVE COMPLEX. HAVE
LOWERED PREVIOUS HIGH TEMPS BY A DEGREE OR TWO... GIVEN INCREASING
CLOUD COVER LATER TODAY... ALONG WITH THE DEVELOPMENT OF EXPECTED
STORMS THIS AFTERNOON. THUS... WILL GO WITH HIGH TEMPS IN THE LOWER
TO MID 90S.
TONIGHT AND SUNDAY: ANY LINGERING CONVECTION IS EXPECTED TO PUSH TO
THE SOUTH AND EAST OF THE AREA AND/OR DISSIPATE BY EARLY SUNDAY
MORNING... WITH MID LEVEL FEATURE SHIFTING TO THE SOUTH AND EAST OF
THE AREA. OVERNIGHT LOWS SHOULD BE WARM AGAIN FOR TONIGHT... WITH
LOWS GENERALLY EXPECTED IN THE LOWER TO MID 70S.
THE CENTER OF THE MID LEVEL RIDGE IS EXPECTED TO REMAIN OVER THE
SOUTH CENTRAL U.S. ON SUNDAY... WITH CENTRAL NC ON THE PERIPHERY OF
THE EXTENDING EASTWARD RIDGE AXIS. THIS SHOULD ALLOW FOR A
CONTINUATION OF WEST TO NORTHWEST FLOW ALOFT. HOWEVER... THE LATEST
GUIDANCE DOES NOT SHOW MUCH IN THE WAY OF ANY DISTURBANCES ALOFT
TRACKING ACROSS THE AREA ON SUNDAY. THUS... EXPECT ANY CONVECTIVE
ACTIVITY WILL BE MORE ISOLATED TO WIDELY SCATTERED. THIS COUPLED
WITH SLIGHTLY HIGHER AFTERNOON LOW LEVEL THICKNESS VALUES THAN
TODAYS SHOULD YIELD HIGH TEMPS IN THE MID TO UPPER 90S... WITH
POSSIBLY A FEW LOCATIONS TOUCHING 100 ACROSS THE SOUTH/SOUTHWESTERN
PORTION OF THE FA. -BSD
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
AN EXPANSIVE UPPER LEVEL RIDGE OVER THE SOUTHERN U.S. AND A LEE SIDE
TROUGH OVER THE PIEDMONT WILL PRODUCE HOT AND MOSTLY DRY WEATHER
FACTORS FOR CENTRAL NC ON MONDAY. LOW LEVEL THICKNESSES VARY BETWEEN
1440S TO AROUND 1450M IN THE AFTERNOON...INDICATIVE OF TEMPERATURES
WELL INTO THE 90S AND POSSIBLY REACHING THE CENTURY MARK. WITH SFC
DEWPOINTS IN THE UPPER 60S TO NEAR 70...HEAT INDICES 102-106 WILL BE
COMMON WITH A HEAT ADVISORY POSSIBLY WARRANTED...MAINLY IN THE
SANDHILLS AND SECTIONS OF THE COASTAL PLAIN.
THE SUB-TROPICAL AIR MASS WILL PRODUCE SLIGHT-MODERATE INSTABILITY
BY AFTERNOON WHICH SHOULD INITIATE/SUPPORT A FEW THUNDERSTORMS
THOUGH COVERAGE AT THIS TIME APPEARS TO BE NO WORSE THAN 20-25
PERCENT AT ITS PEAK. WILL STILL NEED TO MONITOR UPSTREAM CONDITIONS
AS ANY CONVECTIVELY INDUCE VORT MAX IN THE NW FLOW WOULD LEAD TO
ENHANCE CONVECTIVE DEVELOPMENT OVER OUR REGION. EXPECT RATHER STEEP
LOW LEVEL LAPSE RATES MONDAY AFTERNOON WHICH SUGGEST A DECENT CHANCE
FOR STRONG GUSTY WINDS IN THE VICINITY OF ANY STORMS THAT OCCUR.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BY TUESDAY...UPPER RIDGE AMPLIFIES OVER THE CENTRAL U.S...EXTENDING
INTO THE NORTHERN PLAINS. THIS AMPLIFICATION WILL DEEPEN A L/W
TROUGH OVER ONTARIO/QUEBEC...INDUCING NWLY FLOW FROM THE GREAT LAKES
INTO THE CAROLINAS. THIS WILL SEND DISTURBANCES INTO OUR REGION AND
AN ENHANCED THREAT FOR SCATTERED CONVECTION BY TUESDAY. TIMING OF
THESE FEATURES DIFFICULT AND MODEL GUIDANCE IS USUALLY A LITTLE
TARDY. FOR NOW WILL MAINTAIN A CHANCE POP ACROSS THE
REGION...FAVORING TUESDAY AFTERNOON-EVENING. TEMPS TUESDAY DEPENDENT
ON TIMING OF SCATTERED CONVECTION AND EXTENT OF DEBRIS CLOUDINESS
UPSTREAM. FOR NOW WILL ADVERTISE MAX TEMPS ABOUT A CATEGORY LOWER
THAN MONDAY`S MAX TEMPS OVER THE NW THIRD WITH COMPARABLE TEMPS
ELSEWHERE.
WEDNESDAY THROUGH FRIDAY... UPPER RIDGE FLATTENS IN RESPONSE TO A
S/W CROSSING THE NORTHERN PLAINS. TUESDAY`S UPPER LEVEL SHEAR AXIS
PROJECTED TO LIE TO OUR SE ON WEDNESDAY WITH MAINLY WEAK ZONAL FLOW
OVERHEAD. THIS SET-UP CHANGES LITTLE ON THURSDAY. THIS SUGGEST HOT
CONDITIONS WITH MAINLY ISOLATED DIURNALLY DRIVEN CONVECTION BOTH
DAYS. MODEL GUIDANCE SUGGEST AN ENHANCED THREAT FOR CONVECTIVE
COVERAGE BY FRIDAY AS ANOTHER MID-UPPER LEVEL S/W APPROACHES FROM
THE NW. WILL GO WITH A CHANCE POP MOST LOCALES FRIDAY AND TEMPS
REMAINING A CATEGORY OR TWO ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 200 PM SATURDAY...
24 HOUR TAF PERIOD: A LINE OF CONVECTION IS MOVING OVER KRDU AT THIS
TIME AND WILL BE APPROACHING KRWI IN THE NEXT FEW HOURS IF IT HOLDS
TOGETHER. TO THE SOUTH...MORE SCATTERED THUNDERSTORMS WILL APPROACH
THE VICINITY OF KFAY BY 20Z OR SO. WIND GUSTS OF 40-50 KTS ARE
POSSIBLE WITH THESE STORMS BUT THE MAJORITY OF CONVECTION WILL SEE
WIND GUSTS REMAIN UNDER 30 KTS. BEHIND THE LINE...WINDS ARE EXPECTED
TO BRIEFLY GO NORTHWESTERLY BEFORE RETURNING TO A GENERAL
SOUTHEASTERLY FLOW. OVERNIGHT...SOME VFR VISIBILITIES ARE POSSIBLE
AROUND DAYBREAK. WITH NO DISCERNIBLE SHORT WAVE IN THE
AREA...CONVECTIVE COVERAGE SUNDAY AFTERNOON SHOULD BE LESS THAN THIS
AFTERNOON.
LONG TERM: WITH A RETURN TO SOUTHERLY FLOW...EXPECT AN UPTICK IN
DIURNAL COVERAGE OF SHOWERS AND THUNDERSTORMS BEGINNING SATURDAY
AFTERNOON/EVENING AND CONTINUING THROUGH THE END OF THE LONG TERM
WHICH COULD PRESENT SOME ADVERSE CONDITIONS EACH DAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...ELLIS/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
328 PM EDT SAT JUL 18 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION ON SUNDAY. HIGH PRESSURE
WILL BUILD OVER NORTHERN OHIO AND NORTHWESTERN PENNSYLVANIA
BRIEFLY ON MONDAY BEFORE ANOTHER COLD FRONT MOVES THROUGH THE
FORECAST AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HEAT ADVISORY IS IN EFFECT THIS EVENING FOR NORTHWEST OHIO. WITH
THE SHOWERS AND THUNDERSTORMS OVER THE AREA AND THE DEBRIS CLOUD
FROM THIS SYSTEM...HEAT INDEX VALUES WILL NOT EXCEED ADVISORY
CRITERIA. I WILL CANCEL THE HEAT ADVISORY WITH THE ISSUANCE OF
THIS FORECAST. SHOWERS AND THUNDERSTORMS ARE MOVING THROUGH THE
NORTHWEST PARTS OF THE FORECAST AREA THIS AFTERNOON. THESE STORMS
HAVE FORMED ON AN OUTFLOW BOUNDARY FROM THUNDERSTORMS OVERNIGHT.
THE HRRR SHOWS THESE STORMS SLOW PROGESSING EAST THIS AFTERNOON
BUT DECREASING IN INTENSITY. THE MODELS SUGGEST THE STORMS SHOULD
FALL APART BEFORE REACHING THE I-71 CORRIDOR. I HAVE PLACED
SCATTERED POPS IN THE FORECAST FOR AREAS WEST OF I-71. THE LAKE
BREEZE IS GENERATING A FEW SHOWERS OVER NORTHWEST PA. BASED ON
CURRENT SATELLITE IMAGERY THESE SHOWERS COULD ALSO EXTENDED INTO
NORTHEAST OHIO. I WILL PLACE SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THESE AREAS. .
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
A COLD FRONT IS EXPECTED TO MOVE ACROSS THE FORECAST
AREA ON SUNDAY. THE UPPER LEVEL SUPPORT WITH THIS FRONT IS FAIRLY
WEAK BUT THERE IS PLENTY OF INSTABILITY IN THE LOWER ATMOSPHERE.
DEW POINTS IN THE 70S ARE WIDESPREAD OVER MUCH OF THE FORECAST AREA.
MODEL GUIDANCE VARIES SLIGHTLY WITH THE POPS ON SUNDAY WITH THE
PASSAGE OF THE FRONT RANGING BETWEEN 30 TO 60 PERCENT. I AM LEANING
TOWARD THE HIGHER POP RANGE WITH THE HIGH DEWPOINT UNSTABLE AIR
MASS. SHOWERS AND THUNDERSTORMS WILL ALSO PRODUCE HEAVY RAIN AND
ISOLATED FLASH FLOODING IS NOT OUT OF THE QUESTION. I DO NOT
BELIEVE THE THREAT IS WIDESPREAD ENOUGH TO WARRANT A FLASH FLOOD
WATCH BUT WE WILL MONITOR THE SITUATION. HIGH PRESSURE WILL BRIEFLY
BUILD OVER THE REGION ON MONDAY. ANOTHER COLD FRONT WILL MOVE
THROUGH THE FORECAST AREA ON TUESDAY. I WILL KEEP THE THUNDERSTORM
PROBABILITIES IN THE SCATTERED CATEGORY FOR TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGH PRESSURE LOOKS TO BE IN CONTROL OF THE WEATHER ACROSS THE
REGION WEDNESDAY THROUGH FRIDAY. HOWEVER WE WILL NEED TO MONITOR THE
LAKE BREEZE THURSDAY INTO FRIDAY FOR THE POTENTIAL FOR SOME ISOLATED
CONVECTION. CHANCES ARE LOW ENOUGH TO KEEP FROM THE ZONES FOR NOW.
OTHERWISE PARTLY CLOUDY/MOSTLY CLEAR CONDITIONS ARE ANTICIPATED.
THE COOL DAY OF THE LONG TERM WILL BE WEDNESDAY WITH HIGHS RANGING
FROM THE MID 70S TO LOWER 80S. WARMER THURSDAY AND FRIDAY WITH HIGHS
VERY CLOSE TO SEASONAL AVERAGES.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
OUTFLOW FROM CONVECTIVE ACTIVITY OVER MICHIGAN WILL AT LEAST MOVE
ACROSS NW OHIO THIS AFTERNOON. MODELS HAVE VERY POOR HANDLE ON
THE EVOLUTION OF THE THUNDERSTORMS INTO THE EVENING. HAVE PLACED
THE MAIN EMPHASIS OF THE CONVECTION TO AN AREA NEAR AND WEST OF A
KCLE TO KMFD LINE THROUGH AROUND 00Z. THINKING IS THAT THE
EASTERN TAF SITES MAY REMAIN DRY BUT WILL CONTINUE TO MONITOR
CLOSELY AND ADJUST AS NEEDED. IFR CONDITIONS ARE ANTICIPATED WITH
THE STRONGER THUNDERSTORMS. THESE STORMS WILL BE CAPABLE OF
PRODUCING GUSTY WINDS AS WELL.
AFTER THESE LEADING THUNDERSTORMS DECREASE AROUND SUNSET OUR
ATTENTION WILL BE BACK TO THE CENTRAL GREAT LAKES AGAIN AS WE
AWAIT ANOTHER MCS TO DEVELOP ALONG AND AHEAD OF A COLD FRONT THAT
WILL IMPACT THE REGION SUNDAY NIGHT INTO MONDAY. OUTFLOW AND
OVERALL BETTER LOW LEVEL FLOW ON SUNDAY SHOULD BE ENOUGH FOR
THUNDER TO REDEVELOP BY LATE MORNING ACROSS NW OHIO.
WINDS WILL GENERALLY BE FROM THE SOUTHWEST AT 10 TO 15 KNOTS BUT
MUCH STRONGER IN AND NEAR THUNDERSTORMS.
OUTLOOK...AREAS OF NON VFR IN SHRA AND TSRA SUNDAY INTO MONDAY
THEN MORE ISOLATED TUE AND WED.
&&
.MARINE...
POTENTIAL FOR SOME THUNDERSTORMS TO MOVE ACROSS THE LAKE OVERNIGHT
INTO SUNDAY AHEAD OF COLD FRONT. THIS WEAK COLD FRONT WILL CROSS
LAKE ERIE LATE SUNDAY NIGHT INTO MONDAY MORNING WITH A BRIEF PERIOD
OF NORTHERLY WINDS. ANOTHER WEAK FRONT WILL MOVE ACROSS THE REGION
MONDAY NIGHT. HIGH PRESSURE WILL FINALLY RETURN TO THE REGION ON
WEDNESDAY AND PERSIST INTO THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GARNET
NEAR TERM...GARNET
SHORT TERM...GARNET
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
302 PM EDT SAT JUL 18 2015
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE THROUGH SUNDAY BEFORE
A COLD FRONT SETTLES SOUTHWARD THROUGH THE AREA AND COOLS AND
DRIES THE AIRMASS ENOUGH TO REMOVE THE DANGEROUS HEAT INDICES THAT
ARE FELT DURING THE WEEKEND. GIVEN AN EXTREMELY WARM AND UNSTABLE
AIRMASS...SHOWERS AND STORMS MAY DEVELOP AT TIMES THROUGH THE
WEEKEND WITH THE POTENTIAL TO BE STRONG TO SEVERE. THE BEST CHANCE
OF WIDESPREAD STORMS WILL BE SUNDAY AFTERNOON AND EVENING...BUT
CHANCES WILL EXIST THROUGH TONIGHT AS WELL.
&&
.NEAR TERM /THROUGH TONIGHT/...
STILL VERY DIFFICULT/LOW CONFIDENCE FORECAST - AS MAJORITY OF
CONVECTION ALLOWING HIGH RESOLUTION GUIDANCE CONTINUES TO STRUGGLE
MIGHTILY WITH THE EXTREMELY UNSTABLE...WEAKLY SHEARED...AND WEAKLY
FORCED ENVIRONMENT OVER THE OHIO VALLEY. DESPITE RISING HEIGHTS
OVER THE OHIO VALLEY TODAY...A CLUSTER OF STORMS HAS MAINTAINED
ITSELF INTO NWRN OHIO AND IS BEING WATCHED FOR GROWTH/DEVELOPMENT
ON PROPAGATING OUTFLOWS WITH MLCAPE IN EXCESS OF 3500 J/KG
ENTRENCHED OVER THE ILN FORECAST AREA VIA DEW POINTS IN THE MID
70S AND TEMPERATURES APPROACHING/AROUND 90F. DESPITE WEAK SHEAR
/0-6KM BULK SHEAR ABOUT 20KTS AND 0-3KM SHEAR FROM 10 TO
15KTS/...THERE IS CONCERN IN THE SHORT TERM FOR STORMS TO GROW
UPSCALE ON COLD-POOL BALANCED SYSTEM WITH INSTBY /DCAPE TO 1500
J/KG/ COMPENSATING FOR LACK OF SHEAR. SHOULD THIS OCCUR IT WOULD
SEEM A EVOLVING LINE OF STORMS MAY AFFECT MUCH OF THE CWA THIS
AFTERNOON INTO THIS EVENING WITH A WIND DAMAGE THREAT.
ALSO A COMPLICATING FACTOR...VERY WEAK/SUBTLE MCV EMINTATING OUT
OF THE CENTRAL MISSISSIPPI VALLEY MAY SPARK N-S BAND OF LOOSELY
ORGANIZED STORMS OVER INDIANA LATER THIS AFTERNOON WHICH MAY MOVE
INTO THE AREA BEFORE DIMINISHING.
LASTLY...SOME INDICATIONS IN SOME OF THE HIGHER RES GUIDANCE OF A
LATE NIGHT MCS/BOW ECHO MOVING FROM THE UPPER MISSISSIPPI VALLEY
INTO THE GREAT LAKES/OHIO VALLEY LATER IN THE NIGHT.
CONFIDENCE IS EXTREMELY LOW GIVEN HRRR INABILITY TO PROPERLY
HANDLE ONGOING CONVECTION...AND VERY POOR HANDLING OF LAST NIGHT/S
WEAKLY FORCED ACTIVITY. THUS...WILL RUN WITH STORM CHANCES MOST
AREAS FROM THE LATE AFTERNOON THROUGH THE NIGHT AND UPDATE
ACCORDINGLY AS OPPORTUNITIES PRESENT TO INCREASE RAIN CHANCES.
A VERY HUMID NIGHT IS EXPECTED /ASSUMING MCS COLD POOLS REMAIN
LOCALIZED/ WITH SOME RECORD HIGH MINIMUM TEMPS POSSIBLE IN THE
METRO AREAS. EXCESSIVE HEAT WARNING CONTINUES ALL NIGHT FOR URBAN
AREAS OF HAMILTON COUNTY...AND HEAT ADVISORIES ELSEWHERE WILL COME
DOWN BY SUNSET.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
EXPECT ANY REMNANT MCS ACTIVITY /LOW CONFIDENCE HERE/ THAT IS
STILL AROUND ON SUNDAY MORNING TO QUICKLY SHIFT OFF AND WEAKEN
LEAVING ANOTHER VERY WARM/HUMID DAY ON TAP. DEW POINTS WILL RALLY
BACK INTO THE MID 70S AHEAD OF MODERATELY STRONG COLD FRONT
APPROACHING THE AREA FROM THE NORTHWEST BY MIDDAY. THINK TEMPS
WILL BE A TOUCH COOLER MOST AREAS...WITH UPPER 80S TO AROUND 90
EXPECTED...AND MAY BE MORE SO IF CLOUD DEBRIS FROM UPSTREAM MCS
ACTIVITY IS APPRECIABLE. THUS...DO NOT FEEL COMFORTABLE EXTENDING
HEAT ADVISORY BEYOND EXTREME SW OHIO...SERN INDIANA...AND NRN KY
WHERE IT IS CURRENTY PLACED. HEAT INDICES AREA-WIDE THOUGH WILL BE
95-100F AND HIGHEST IN THE ADVISORY AREA /LOW 100S LIKELY/.
ADVISORY MAY NEED TO BE EXPANDED NORTH/EAST A BIT IF BETTER
INSOLATION THAN WHAT IS EXPECTED DEVELOPS.
CONVECTION SHOULD INITIATE BY 18Z ACROSS NRN OH BACK INTO INDIANA
AND SINK SSE INTO THE AREA. PRETTY STRONG AGREEMENT IN THE
GUIDANCE OF A FAIRLY SOLID LINE OF STORMS AMIDST STRONG INSTBY BUT
AGAIN MODEST TO MARGINAL SHEAR. WIND DAMAGE TO BE THE MAIN THREAT
BUT 0-3KM SHEAR VECTORS...WHILE IN GOOD ORIENTATION TO THE
FORCING...ARE A LITTLE WEAK IN MAGNITUDE. HOWEVER LIKE RECENT
DAYS...EXTREME INSTBY/DCAPE MAY AUGMENT. MAY ALSO BE A FLASH FLOOD
THREAT GIVEN ORIENTATION OF LINE BUT STORMS SHOULD PROPOGATE TO
SOME DEGREE SO WILL HOLD ON A FLASH FLOOD WATCH FOR NOW. EXPECT
LINE TO SETTLE THROUGH AND OUT OF THE AREA LATER IN THE EVENING
WITH SKIES TURNING CLEAR/PARTLY CLOUDY IN ITS WAKE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
COLD FRONT WILL BE NEAR OR JUST SOUTH OF THE OHIO RIVER BY MONDAY
MORNING WHERE IT WILL BECOME QUASI STATIONARY DURING THE DAY. WEAK
DISTURBANCES WITHIN THE FLOW ALOFT ALONG WITH THE BOUNDARY MEANS
THAT A CHANCE OF SHOWERS AND THUNDERSTORMS HAVE TO BE KEPT INTO THE
FORECAST FOR THESE LOCATIONS.
FOR MONDAY NIGHT INTO TUESDAY NIGHT...HAVE USED A BLEND OF THE NAM-
WRF AND ECMWF FOR TIMING OF NEXT S/WV ENERGY IN DEVELOPING NORTHWEST
FLOW ALOFT ALONG WITH ANOTHER COLD FRONT. AS S/WV ENERGY DIGS EAST
THROUGH THE GREAT LAKES...ANOTHER FRONT WILL GRADUALLY BE PUSHED
SOUTHEAST THROUGH THE REGION. WILL PLACE A CHANCE OF SHOWERS/STORMS
FOR ALL LOCATIONS BY TUESDAY MORNING AND CONTINUE THAT THREAT
THROUGH THE DAY. AS THE FRONT DROPS SOUTH OF THE OHIO RIVER BY
WEDNESDAY MORNING...AND WITH THE LOSS OF DAYTIME HEATING...PCPN
THREAT WILL PUSH SOUTH AND DIMINISH OVERNIGHT.
FOR THE PERIOD WEDNESDAY THROUGH FRIDAY...AS MID LEVEL RIDGE TRIES
TO REASSERT ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY...EXCEPT FOR ALONG
AND SOUTH OF THE OHIO ON WEDNESDAY...WHERE LINGERING INSTABILITY MAY
POP A DIURNAL SHOWER OR STORM.
WILL CONTINUE THE DRY WEATHER INTO SATURDAY BUT BY THAT TIME MODELS
SUGGEST THAT ANOTHER WEAK FRONT MAY ARRIVE BY THEN OR SUNDAY.
TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL THROUGH THURSDAY
WITH MAINLY TYPICAL JULY READINGS BY THE END OF THE WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
WHILE THE ABOVE NEAR-TERM DISCUSSION SHOWS THE THOUGHT PROCESS OF
STORMS DEVELOPING THIS AFTERNOON AND EVENING...PUTTING THEM AT A
POINT WITH ANY CONSIDERABLE CERTAINTY IS DIFFICULT. WILL CONTINUE
TO LEAVE MENTION OF THUNDERSTORMS OUT OF TAFS ATTM BUT USE A VCTS
AT KDAY WHERE THE PROBABILITY IS HIGHER THAN EVERYWHERE ELSE GIVEN
THE EXPECTED SE SLIDE OF AN MCS LATER TONIGHT.
THE MCS IS A LOW PROBABILITY OF OCCURRENCE BUT WILL HAVE A HIGH
IMPACT IF IT DOES. WILL KEEP AN EYE OUT ON UPSTREAM
OBS...PARTICULARLY RADAR AND SATELLITE AND AMEND WHEN THE SYSTEM
DEVELOPS OR MODELS APPEAR TO PICK UP ON WHAT IS BEING FORECAST
RIGHT NOW. EXPECT VFR CONDITIONS UNTIL CONVECTION POPS LATER TODAY
AND WHEN/IF MVFR FOG HITS RIVER VALLEYS AND KLUK TONIGHT.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY THROUGH TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ026-034-035-
042>046-051>056-060>065-072>074-079>082-088.
HEAT ADVISORY UNTIL 8 PM EDT SUNDAY FOR OHZ070-071-078.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SUNDAY FOR OHZ077.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ097>100.
HEAT ADVISORY UNTIL 8 PM EDT SUNDAY FOR KYZ089>096.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ050-058-059.
HEAT ADVISORY UNTIL 8 PM EDT SUNDAY FOR INZ066-073>075-080.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...HICKMAN
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1103 AM CDT SAT JUL 18 2015
.UPDATE...
MORNING FORECAST UPDATE.
&&
.DISCUSSION...
OVERALL NOT A LOT OF CHANGE IN THE FORECAST. PRECIP WATER VALUES
RANGE FROM 1.7 TO 2.0 INCHES BASED ON SOUNDINGS AND GOES SATELLITE
DERIVED DATA. STILL A STRONG ENOUGH RIDGE ALOFT TO LIMIT ACTIVITY
MORE SO THAN YESTERDAY. STILL A SMALL CHANCE FOR A PASSING SHOWER
BUT EXPECT MOST AREAS TO STAY DRY. KEEP RAIN CHANCES AROUND 20
PERCENT BUT MENTION ISO COVERAGE. ONLY OTHER CONCERN WILL BE HEAT
INDEX VALUES. GIVEN ENOUGH DEEP MOISTURE...DO NOT THINK MIXING
WILL BE QUITE ENOUGH TO LOWER DEWPOINTS. TEMPS MAY BE A TAD LOWER
BUT STILL ENOUGH FOR HIGH HEAT INDEX VALUES NEAR 105. AT 16Z MOST
AREAS HAD HEAT INDEX VALUES AROUND 95 TO 103F. OTHERWISE FORECAST
LOOKS ON TRACK.
39
&&
.PREV DISCUSSION... /ISSUED 650 AM CDT SAT JUL 18 2015/
AVIATION...
A REPEAT MVFR DECK ADVANCING IN FROM CENTRAL TEXAS MAY CLIP AND
AFFECT KCLL FOR A COUPLE OF HOURS THIS MORNING. GENERALLY AREAWIDE
VFR THROUGHOUT THE PERIOD. HIGHER MOISTURE WITHIN AN AIR MASS THAT
WILL HEAT UP INTO THE MID 90S WILL LIKELY PRODUCE WIDELY SCATTERED
SHOWERS AND AN ISOLATED THUNDERSTORM. ANY CONVECTIVE ACTIVITY WILL
OCCUR FROM MID MORNING CLOSER TO THE COAST THROUGH THE LATE AFTERNOON
HOURS FURTHER INLAND. MAJORITY OF THE DAY WILL EXPERIENCE FAIR WEATHER
CUMULUS WITH 5-15 KT SOUTHWEST-VEERING-SOUTHERLY NEAR SURFACE WINDS.
31
PREV DISCUSSION... /ISSUED 303 AM CDT SAT JUL 18 2015/
DISCUSSION...
LINGERING MOISTURE LEVELS AND A SLIGHT WEAKNESS ALOFT MIGHT BE ENOUGH
TO GENERATE SOME SHOWERS AND POSSIBLE THUNDERSTORMS AGAIN TODAY...BUT
DO THINK COVERAGE WILL BE LESS THAN WHAT PARTS OF THE AREA SAW ON FRIDAY.
SPC`S LATEST DAY 1 CONVECTIVE OUTLOOK HAS PARTS OF OUR AREA IN GENERAL
THUNDER ONCE AGAIN...AND THE HRRR RUNS COMING IN SO FAR EARLY THIS MORNING
DO SHOW SOME ACTIVITY DEVELOPING DURING THE DAY. SO WILL CARRY 20% POPS
FOR THE COUNTIES GENERALLY ALONG AND SOUTH OF THE HIGHWAY 59 CORRIDOR.
WILL GO BACK TO A DRY FORECAST BEGINNING THIS EVENING AND CONTINUING
ON FOR THE REST OF THE WEEKEND AND THROUGHOUT THE UPCOMING WEEK AS
IT LOOKS LIKE MID/UPPER LEVEL RIDGING WILL BE STRONG ENOUGH TO KEEP
THE MAJORITY OF OUR AREA VERY WARM AND DRY. EVEN THOUGH WE WILL CONTINUE
TO SEE HEAT INDEX VALUES ACROSS A MAJORITY OF OUR AREA UNDER HEAT ADVISORY
LEVELS...US AND OUR PARTNERS WILL NEED TO CONTINUE TO GET THE WORD OUT
ON HEAT SAFETY.
FOR JULY 1-17...GALVESTON`S AVERAGE TEMPERATURE HAS BEEN 85.7 DEGREES.
IF THIS VALUE HOLDS FOR THE REST OF THE MONTH...JULY 2015 WOULD GO
DOWN AS THE 8TH WARMEST JULY ON RECORD. IN ADDITION...THEIR RAINFALL
TOTAL FOR THE MONTH OF 0.23 INCHES WOULD GO DOWN AS THE 7TH DRIEST
JULY ON RECORD. 42
MARINE...
HIGH PRESSURE CONTINUES TO RESIDE OVER THE GULF THE NEXT SEVERAL
DAYS AFFORDING A LIGHT SOUTHWEST TO SOUTHEAST WIND...PERIODS OF
WEEKEND SCATTERED SHOWERS. A SLIGHTLY TIGHTER LAND AND SEA THERMAL
GRADIENT WILL STRENGTHEN WINDS A BIT DURING THE OVERNIGHT HOURS.
SEAS WILL GENERALLY REMAIN AT OR UNDER THREE FEET...WITH AVERAGE
FOUR HEIGHTS WHERE THIS MORE MODERATE LATE EVENING INTO EARLY
MORNING ONSHORE FETCH EXISTS. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 76 97 76 98 / 10 0 0 0 10
HOUSTON (IAH) 96 77 97 76 97 / 20 0 10 0 10
GALVESTON (GLS) 91 82 91 81 92 / 20 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
209 PM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM EDT SATURDAY...
CONVECTION IS STARTING TO TAKE PLACE JUST SOUTH OF THE
FORECAST AREA AND ALSO ACROSS THE FAR SOUTHEAST PART OF THE
FORECAST AREA. THIS REGION HAS BEEN OUTSIDE THE REGION OF
RESIDUAL CLOUD COVER FROM THE CONVECTION EARLY THIS MORNING. THAT
SAME CLOUD COVER HAS BEEN ERODING...AND IN ITS WAKE...AT LEAST
SOME CUMULUS CLOUDS HAVE BEEN FORMING ACROSS PARTS OF SOUTHWEST
VIRGINIA. ANTICIPATING ADDITIONAL DEVELOPMENT THIS AFTERNOON ACROSS
THE FORECAST AREA AS SURFACE HEATING CONTINUES. THE FOCUS FOR THE
BEST COVERAGE IS ACROSS THE PIEDMONT REGION WHERE THE LATEST SPC
DAY ONE CONVECTIVE OUTLOOK STILL PLACES A MARGINAL RISK IN THIS
AREA. HAVE TWEAKED HOURLY TEMPERATURE...DEW POINT AND SKY COVER
BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
MID-AFTERNOON.
AS OF 945 AM EDT SATURDAY...
LITTLE REMAINS OF THE EARLIER DYING MCS THAT ENTERED THE REGION
EARLIER THIS MORNING. AT BEST...ISOLATED TO PATCHY LIGHT RAIN
SHOWERS WERE STILL NEAR AND NORTHEAST OF ROANOKE VIRGINIA ALONG
THE INTERSTATE-81 CORRIDOR. PLENTY OF RESIDUAL CLOUD COVER
CONTINUES TO EXIST ACROSS THE CENTRAL PORTION OF THE FORECAST
AREA...AND IS SLOW DRIFTING EASTWARD. THE FAR WESTERN AND
SOUTHEASTERN PARTS OF THE AREA ARE RECEIVING MOSTLY SUNNY TO SUNNY
CONDITIONS. IT WILL BE THESE TWO LOCATIONS THAT WILL HAVE THE BEST
OPPORTUNITY OF SHOWER AND THUNDERSTORM DEVELOPMENT HEADING INTO
THE AFTERNOON HOURS. WHILE THE CENTRAL PORTION OF THE AREA WILL
EVENTUALLY HAVE SOME SUNSHINE...IT WILL BE LATER IN THE DAY...AND
THIS REGION WILL BE SLOWER TO EXPERIENCE SURFACE BASED CONVECTION
DEVELOP. THAT IS NOT TO SAY THAT ACTIVITY THAT FORMS IN THE WEST
MAY NOT MOVE INTO CENTRAL PORTIONS LATER THIS AFTERNOON. THE
LATEST FORECAST UPDATE WILL REFLECT NO MAJOR CHANGES IN THE BIG
PICTURE TODAY. HOWEVER...IN THE NEAR TERM...A GREATER DISTINCTION
HAS BEEN MADE WHERE NO PRECIPITATION IS EXPECTED OVER THE NEXT FEW
HOURS VERSUS WHERE SCATTERED ACTIVITY IS EXPECTED. LIKEWISE...A
SIMILAR DISTINCTION HAS BEEN MADE TO CLOUDY VERSUS MOSTLY SUNNY TO
SUNNY AREAS.
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 145 PM EDT SATURDAY...
VFR CONDITIONS WILL PREVAIL ACROSS MOST OF THE REGION THROUGH THE
EARLY EVENING HOURS. ISOLATED TO SCATTERED SHOWERS AND STORMS ARE
EXPECTED TO DEVELOP AFTER 20-21Z/4PM-5PM. SOME BRIEF IFR/MVFR
CONDITIONS ARE EXPECTED UNDER THE HEAVY CORES THAT DEVELOP.
ANY SHOWERS OR STORMS THAT CONTINUE INTO THE EVENING HOURS WILL
WILL DISSIPATE BY 03Z/11PM. OVERNIGHT...ANTICIPATE SOME PATCHY
MVFR LIGHT FOG ALONG WITH SOME PATCHY MVFR STRATO-CU TO DEVELOP.
OTHERWISE...VFR CONDITIONS AND LIGHT OR CALM WINDS ARE EXPECTED.
ANY SUB-VFR CONDITIONS WILL IMPROVE TO VFR BY 12-13Z/8AM-9AM.
EXTENDED AVIATION DISCUSSION...
SUNDAY AFTERNOON AND EVENING SHOULD BRING MINIMAL CONVECTION AS A
SHORTWAVE RIDGE SITS OVER THE REGION ALONG A PREVAILING WESTERLY
FLOW.
MONDAY INTO TUESDAY...CONVECTION INCREASES AGAIN ACROSS THE AREA
WITH APPROACH AND PASSAGE OF A SHORTWAVE TROUGH AND ASSOCIATED
COLD FRONT. SUB-VFR CONDITIONS AGAIN WILL ACCOMPANY THE HEAVIER
CONVECTION.
WEDNESDAY...THE FRONTAL BOUNDARY MAY STILL BE CLOSE ENOUGH TO
SOUTHERN PORTION OF THE REGION FOR SOME LINGERING PRECIPITATION
AND SUB-VFR CONDITIONS.
HIGH PRESSURE LOOKS TO TAKE HOLD OF THE WEATHER FOR THE ENTIRE
REGION ON THURSDAY. EARLY MORNING MOUNTAIN AND RIVER VALLEY FOG
WILL BE POSSIBLE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
104 PM EDT SAT JUL 18 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE MOUNTAINS FROM THE
WEST THIS MORNING BEFORE EXITING THE PIEDMONT LATER THIS AFTERNOON.
ANOTHER WEAK FRONT WILL DRIFT INTO THE REGION FROM THE NORTHWEST
BY MONDAY...STALLING NEAR US AS WEAK WAVES OF LOW PRESSURE RIDE
ALONG THE BOUNDARY THROUGH THE FIRST HALF OF NEXT WEEK. THIS WILL
CONTINUE TO RESULT IN WARM AND HUMID CONDITIONS THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM EDT SATURDAY...
CONVECTION IS STARTING TO TAKE PLACE JUST SOUTH OF THE
FORECAST AREA AND ALSO ACROSS THE FAR SOUTHEAST PART OF THE
FORECAST AREA. THIS REGION HAS BEEN OUTSIDE THE REGION OF
RESIDUAL CLOUD COVER FROM THE CONVECTION EARLY THIS MORNING. THAT
SAME CLOUD COVER HAS BEEN ERODING...AND IN ITS WAKE...AT LEAST
SOME CUMULUS CLOUDS HAVE BEEN FORMING ACROSS PARTS OF SOUTHWEST
VIRGINIA. ANTICIPATING ADDITIONAL DEVELOPMENT THIS AFTERNOON ACROSS
THE FORECAST AREA AS SURFACE HEATING CONTINUES. THE FOCUS FOR THE
BEST COVERAGE IS ACROSS THE PIEDMONT REGION WHERE THE LATEST SPC
DAY ONE CONVECTIVE OUTLOOK STILL PLACES A MARGINAL RISK IN THIS
AREA. HAVE TWEAKED HOURLY TEMPERATURE...DEW POINT AND SKY COVER
BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
MID-AFTERNOON.
AS OF 945 AM EDT SATURDAY...
LITTLE REMAINS OF THE EARLIER DYING MCS THAT ENTERED THE REGION
EARLIER THIS MORNING. AT BEST...ISOLATED TO PATCHY LIGHT RAIN
SHOWERS WERE STILL NEAR AND NORTHEAST OF ROANOKE VIRGINIA ALONG
THE INTERSTATE-81 CORRIDOR. PLENTY OF RESIDUAL CLOUD COVER
CONTINUES TO EXIST ACROSS THE CENTRAL PORTION OF THE FORECAST
AREA...AND IS SLOW DRIFTING EASTWARD. THE FAR WESTERN AND
SOUTHEASTERN PARTS OF THE AREA ARE RECEIVING MOSTLY SUNNY TO SUNNY
CONDITIONS. IT WILL BE THESE TWO LOCATIONS THAT WILL HAVE THE BEST
OPPORTUNITY OF SHOWER AND THUNDERSTORM DEVELOPMENT HEADING INTO
THE AFTERNOON HOURS. WHILE THE CENTRAL PORTION OF THE AREA WILL
EVENTUALLY HAVE SOME SUNSHINE...IT WILL BE LATER IN THE DAY...AND
THIS REGION WILL BE SLOWER TO EXPERIENCE SURFACE BASED CONVECTION
DEVELOP. THAT IS NOT TO SAY THAT ACTIVITY THAT FORMS IN THE WEST
MAY NOT MOVE INTO CENTRAL PORTIONS LATER THIS AFTERNOON. THE
LATEST FORECAST UPDATE WILL REFLECT NO MAJOR CHANGES IN THE BIG
PICTURE TODAY. HOWEVER...IN THE NEAR TERM...A GREATER DISTINCTION
HAS BEEN MADE WHERE NO PRECIPITATION IS EXPECTED OVER THE NEXT FEW
HOURS VERSUS WHERE SCATTERED ACTIVITY IS EXPECTED. LIKEWISE...A
SIMILAR DISTINCTION HAS BEEN MADE TO CLOUDY VERSUS MOSTLY SUNNY TO
SUNNY AREAS.
AS OF 227 AM EDT SATURDAY...
MAIN CONCERN INITIALLY WITH RESIDUAL MCS CURRENTLY APPROACHING THE WESTERN
SLOPES AND JUST HOW FAR EAST THIS COMPLEX WILL GET THIS MORNING BEFORE
FADING. LATEST HRRR BRINGS A BAND OF REMNANT CONVECTION INTO THE FAR
WESTERN COUNTIES NEAR DAWN BEFORE SLIDING WEAKER SHOWERS EAST ACROSS
THE BLUE RIDGE...AND INTO THE EAST BEFORE FADING LATER THIS MORNING.
THUS BEEFED UP POPS WESTERN THIRD EARLY ON PENDING TRENDS BUT STAYED
WITH MAINLY CHANCE COVERAGE...EXCEPT LIKELYS MTN EMPIRE REGION
EARLY THIS MORNING FOR NOW GIVEN LESS INSTABILITY SEEN OUTSIDE THE
FAR WEST ATTM.
ONCE THIS FEATURE PASSES EAST...QUESTIONS WITH THE DEGREE OF ADDED
REDEVELOPMENT THIS AFTERNOON AS THE REMNANT MID LEVEL WAVE WORKS
EAST OF THE MOUNTAINS AND ENCOUNTERS THE EASTERN LEE TROF. MAIN
CONCERN IS WITH LACK OF DEEP INSTABILITY AS DEBRIS CLOUD SHIELD IN
THE WAKE OF THE REMNANT MCS COULD LINGER AND HELP INHIBIT ADDED
CONVECTION UNTIL LATE WITH ORGANIZATION LACKING. HOWEVER APPEARS
JUST ENOUGH HEATING/FOCUS TO HELP SCATTERED SHRA/TSRA REDEVELOP
OVER THE FAR WEST INITIALLY WHERE SHOULD SEE MORE SUN
SOONER...WITH COVERAGE HEADING OUT EAST LATER THIS AFTERNOON WHERE
AIDED BY POSSIBLE DIFFERENTIAL HEATING IF THE WESTERLY DOWNSLOPE
IS NOT TOO STRONG. THIS SIMILAR TO THE LATEST NCAR ENSEMBLE
ALTHOUGH SOLUTIONS QUITE VARIED FROM LITTLE ADDED PRECIP BEHIND
THE INITIAL MORNING BATCH PER NAM/CMC/EC...AND A COUPLE HIRES
MODELS...TO MOSTLY OVER THE WEST LIKE THE GFS. FOR NOW WILL LEAVE
IN CHANCE POPS MOST AREAS WITH BEST POTENTIAL FOR STRONGER PULSE
TSRA OVER THE SOUTH AND EAST WHERE FORECAST DCAPES ARE HIGHEST
PROVIDED SUFFICIENT HEATING DESPITE WEAK WIND FIELDS ALOFT. HIGH
TEMPS ALSO A BIT TRICKY GIVEN CLOUD SHIELD/SHRA EARLY AND PERHAPS
ENOUGH SUN TO REACH WARMER LATE DAY HIGHS OUT WEST. GIVEN
CLOUDIER TRENDS...LOWERED HIGHS A CAT OR SO WEST AND LEFT THE EAST
CLOSER TO THE COOLER MAV MOS AT THIS POINT.
WAVE PASSES TONIGHT WITH MOST EVENING CONVECTION LIKELY OVER THE
SOUTH AND EAST UNDER THE EXITING LOBE OF DEEPER MOISTURE. HOWEVER
UPSLOPE FLOW ACROSS THE NW ENOUGH TO KEEP SOME ISOLATED SHRA GOING
THERE OVERNIGHT WITH ONLY ISOLATED RESIDUAL -SHRA POSSIBLE ELSW
AFTER MIDNIGHT UNDER NW FLOW ALOFT AND LACK OF ADDED FOCUS. WILL
STILL BE WARM/MUGGY AS EXPECT MOIST DEWPOINTS AND CLOUDS TO HOLD
LOWS UP CLOSER TO THE 68-73 RANGE OVERALL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 AM EDT SATURDAY...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE ARKLATEX REGION THROUGH
EARLY NEXT WEEK. THE POSITION OF THIS RIDGE MAY SEND A FEW
DISTURBANCES OUR WAY FROM THE MIDWEST...BUT THAT HAS YET TO BE SEEN
WITH THE LATEST MODELS. MODELS SUGGESTING A PULSE STORM ENVIRONMENT
WITH STORMS INITIATING OVER THE MOUNTAINS IN THE AFTERNOON...DRIFTING
EAST TO A LEE TROUGH OVER THE PIEDMONT IN THE EVENING. MODELS ARE A
LITTLE SLOWER WITH A COLD FRONT ENTERING THE OHIO VALLEY MONDAY.
THEREFORE WILL SLOW THE ARRIVAL OF ANY PREFRONTAL CONVECTION
ENTERING THE AREA UNTIL LATE MONDAY NIGHT-TUESDAY.
OUTSIDE OF SOME SCATTERED THUNDERSTORMS EACH AFTERNOON...THE HEAT
WILL BE THE MAIN TOPIC OF WEATHER CONVERSATIONS. TEMPERATURES SUNDAY
AND MONDAY AFTERNOON WILL RUN AROUND 5F WARMER THAN NORMAL...WITH
UPPER 80S WEST TO THE LOW TO MID 90S EAST. DEW POINTS WILL ALSO RUN
WARM AND IN THE UPPER 60S TO LOWER 70S. APPARENT TEMPERATURES...FOR
AT LEAST A FEW HOURS EACH AFTERNOON...WILL FEEL LIKE THE LOWER 90S
ACROSS THE MOUNTAINS AND AROUND 98F-103F ACROSS THE FOOTHILLS AND
PIEDMONT COUNTIES OF NW NC/SW VA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
EXPECT TO START TUESDAY MORNING WITH THE FRONT DRAPED AROUND OUR
AREA. LOW PRESSURE ARRIVING FROM THE WEST DURING THE AFTERNOON AND
EVENING WILL TRIGGER MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
FOR THE AFTERNOON AND EVENING. PASSAGE OF THE LOW ACROSS OUR AREA
WILL HELP PUSH THE FRONT INTO THE CAROLINAS TUESDAY NIGHT.
UPPER LEVEL WINDFLOW WILL TRANSITION TO A WEAK WEST TO EAST PATTERN
FOR THE MIDDLE OF NEXT WEEK...BRINGING A SERIES OF SUBTLE
DISTURBANCES ACROSS THE MID ATLANTIC. AS SUCH...EXPECT A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY...MAINLY THOSE WHICH DEVELOP WITH
DAYTIME HEATING. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 640 AM EDT SATURDAY...
CLUSTERS OF SHRA/TSRA CONTINUE OVER PARTS OF THE MOUNTAINS EARLY
THIS MORNING...BUT MAINLY REMOVED FROM ANY OF THE TAF SITES.
EXPECT A FEW ADDED SHOWERS MAY AFFECT KBLF/KLWB THROUGH MID
MORNING SO INCLUDING MAINLY A VCSH/VCTS FOR A COUPLE MORE HOURS
THIS MORNING. SOME OF THESE SHOWERS MAY ALSO WORK OUT TO KBCB
AND KROA BUT TOO IFFY TO INCLUDE A VCSH MENTION FOR NOW.
ADDITIONAL SHOWER DEVELOPMENT MAY PUSH INTO EASTERN SECTIONS
THIS MORNING AS WELL WITH DEBRIS CLOUDS MAKING FOR LINGERING LOW
END VFR TO MVFR CIGS OVER THE WEST AND THROUGH MIDDAY. SHOULD
FINALLY SEE A RETURN TO VFR FOR A WHILE THIS AFTERNOON AS HEATING
WINS OUT WITH THE BEST THREAT FOR ADDED CONVECTION IN THE LEE OF
THE RIDGES AS THE REMNANT WAVE HEADS EAST AND COMBINES WITH
AFTERNOON HEATING. EXPECT CIGS BY LATE MORNING TO BE IN THE MID
DECK/AC AREA...WITH SCT TO BKN CU FORMING IN THE AFTERNOON AROUND
4-5KFT. KEPT VCTS AT KROA/KLYH/KDAN WHERE POPS ARE HIGHEST AND
ADDED IN AT KBLF AROUND 19Z AND BEYOND GIVEN POTENTIAL FOR HEATING
TO REBOUND BEHIND THE EARLY CLOUD SHIELD/SHRA.
ANY LINGERING SHOWERS SHOULD EXIT THE EAST/SOUTH THIS EVENING
FOLLOWED BY CLEARING SKIES UNDER LIGHT WINDS. THIS MAY LEAD TO FOG
DEVELOPMENT ESPCLY IN THE VALLEYS OVERNIGHT AND AT ANY LOCATION
THAT SEES HEAVIER DOWNPOURS TODAY. APPEARS KLWB LIKELY TO DROP
DOWN TO LIFR IN FOG/STRATUS WITH MVFR TO IFR AT KBCB AND PERHAPS A
PERIOD OF MVFR OR WORSE AT KLYH/KDAN LATE TONIGHT.
EXTENDED AVIATION DISCUSSION...
SUNDAY APPEARS TO BRING A MINIMUM IN CONVECTION WITH SHORT WAVE
RIDGING. MONDAY SHOULD SEE AN INCREASE IN CONVECTION
AGAIN...POTENTIALLY LINGERING INTO TUESDAY WITH WAVES OF LOW
PRESSURE RIDING THROUGH THE REGION IN A WEST TO WEST- NORTHWEST
FLOW. BOUNDARY MAY PUSH FAR ENOUGH SOUTH IN THE WAKE OF THE
CONVECTION TO BRING MAINLY VFR WITH ONLY ISOLATED
AFTERNOON/EVENING SHRA/TSRA ACROSS THE SOUTH ON WEDNESDAY.
OUTSIDE SHRA/TSRA AND EARLY MORNING FOG/LOW CLOUDS...GENERALLY
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RAB/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...AMS/NF
AVIATION...JH/JR/RAB/WP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
253 PM CDT SAT JUL 18 2015
.TONIGHT AND SUNDAY - CONFIDENCE...MEDIUM.
THE LAST OF A SMALL MCS WILL MOVE THROUGH THE FORECAST AREA THIS
EVENING. THE 18.18Z HRRR IS SHOWING DRY CONDITIONS OVERNIGHT ONCE
THIS MCS MOVES OUT. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE
AREA OVERNIGHT AND INTO THE EARLY MORNING HOURS SUNDAY. WINDS WILL
VEER TO A MORE WESTERLY DIRECTION OVERNIGHT AND FROM THE NORTHWEST
BY DAWN. WINDS WILL BE A LITTLE GUSTY AS WINDS REMAIN FROM THE SOUTH
AHEAD OF THE COLD FRONT BOUNDARY. THE COLD FRONT COULD SPARK A
THUNDERSTORM OR TWO AS IT SWINGS THROUGH THE AREA OVERNIGHT...SO
KEPT SLIGHT CHANCE POPS FOR NOW. RAIN CHANCES WILL BE GONE BY LATER
SUNDAY MORNING. EXPECT DRIER CONDITIONS FOR SUNDAY...ALONG WITH
SLOWLY CLEARING SKIES.
.SUNDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
DRY WITH HIGH PRESSURE BRIEFLY MOVING THROUGH. LOWS SHOULD FEEL
MORE REFRESHING THAN WHAT WE/VE SEEN OVER THE PAST FEW NIGHT.
.MONDAY INTO MONDAY NIGHT...FORECAST CONFIDENCE IS
A COLD FRONT WILL DROP IN QUICKLY MONDAY AFTERNOON AND EVENING.
MOISTURE WILL STREAM NORTH AHEAD OF THE FRONT...BUT THE NAM IS
BEING TOO AGGRESSIVE AS USUAL. FOR NOW WILL CARRY CHCY POPS WITH
THIS POSITIVE TILT SYSTEM.
.TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
REFRESHING HIGH PRESSURE BUILDS IN WITH NOTICEABLY LOWER DEW
POINTS AND NEAR NORMAL TEMPERATURES. LOOKS DRY THIS PERIOD.
.THURSDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
A SLOW MOVING TROUGH OF LOW PRESSURE WILL PUSH INTO THE REGION BY
THE END OF NEXT WEEK RAISING A SMALL THREAT...AT LEAST AT THIS
TIME...FOR SHOWERS AND A FEW THUNDERSTORMS. THERE IS PLENTY OF
MODEL DISAGREEMENT SO STAY TUNED.
&&
.AVIATION/00Z TAFS/...
A LINE OF SHOWERS AND THUNDERSTORMS IS MOVING OFF TO THE EAST THIS
AFTERNOON...BRINGING HEAVY RAINS AND REDUCED CIGS AND VSBYS. THIS
LINE WILL AFFECT THE MKE AND ENW TAF SITES LATER THIS AFTERNOON.
CONDITIONS COULD QUICKLY CHANGE FROM VFR TO MVFR AS THIS LINE MOVES
THROUGH. THINGS SHOULD DRY UP ONCE THIS LINE OF STORMS MOVES OUT.
EXPECT WINDS TO SLOWLY VEER OVERNIGHT TO A MORE WESTERLY DIRECTION
AHEAD OF A COLD FRONT EXPECTED TO MOVE THROUGH TONIGHT. AN ISOLATED
THUNDERSTORM IS POSSIBLE TONIGHT AS THIS COLD FRONT MOVES THROUGH.
&&
.MARINE...
A LINE OF THUNDERSTORMS WILL MOVE THROUGH THE NEARSHORE WATERS THIS
AFTERNOON. WINDS COULD BE GUSTY BETWEEN 25 AND 35 KTS AS THIS LINE
MOVES THROUGH. A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT
AND BRING WINDS AROUND TO THE WEST AND NORTHWEST THROUGH THE REST OF
THE WEEKEND.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...JTS
SUNDAY NIGHT THROUGH SATURDAY...DAVIS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1105 AM CDT SAT JUL 18 2015
.UPDATE...
CONTINUED THE HEAT ADVISORY AS IS FOR NOW...FROM NOON UNTIL 8 PM
TODAY ACROSS MOST OF THE AREA. SHOULD GET ENOUGH SUN TO GET HIGHS
TO AROUND 90 DEGREES. DEW POINTS SHOULD ALSO RECOVER INTO THE
LOWER TO MID 70S AT LEAST...WHICH GIVES HEAT INDEX VALUES AROUND
100 DEGREES. ONE CONCERN IS POSSIBLE CONVECTION AND ASSOCIATED
CLOUDS...WHICH WOULD LIMIT HEATING THIS AFTERNOON. ANOTHER CONCERN
IS ONSHORE WINDS LINGERING THIS AFTERNOON NEAR THE LAKE FROM
MILWAUKEE SOUTHWARD...WHICH WOULD LIMIT HIGHS THERE.
A FEW CELLS ARE DEVELOPING IN GRANT COUNTY...AHEAD OF ADVANCING
500 MB VORTICITY MAXIMUM IN NORTHEAST IOWA. THIS FEATURE IS
EXPECTED TO PUSH EAST THROUGH THE AREA THIS AFTERNOON. IN
ADDITION...OUTFLOW BOUNDARY FROM EARLY MORNING STORMS LIES FROM
THE CHICAGO AREA INTO SOUTHERN GRANT COUNTY. COMBINATION OF
OUTFLOW BOUNDARY AND ADVANCING VORTICITY MAXIMUM MAY HELP GENERATE
MORE CELLS OVER THE NEXT HOUR OR TWO.
HRRR MODEL TAKES THESE INITIAL CELLS AND DEVELOPS AN AREA OF
STRONG CONVECTION AS IT MOVES EAST ACROSS THE AREA THIS AFTERNOON.
ONCE CONVECTIVE INHIBITION IS OVERCOME BY EARLY AFTERNOON...SHOULD
SEE STRONG/SEVERE CONVECTION DEVELOP GIVEN STRONG MEAN LAYER CAPE
AND DEEP LAYER SHEAR VALUES. LARGE HAIL AND DAMAGING WINDS WOULD
BE THE MAIN HAZARDS. ANY TORNADO RISK WOULD BE TIED TO THE OUTFLOW
BOUNDARY LOCATION...WHICH AT THIS TIME LOOKS TO REMAIN SOUTH OF
THE AREA.
WILL UPDATE POPS TO REFLECT AFTERNOON TIMING WITH STORMS...WHICH
SHOULD EXIT THE EAST BY AROUND 00Z SUNDAY.
&&
.AVIATION/18Z TAFS/...
POSSIBLE STRONG/SEVERE STORMS MAY PUSH EAST ACROSS SOUTHERN
WISCONSIN THIS AFTERNOON. ALREADY SEEING DEVELOPMENT IN FAR
SOUTHWEST WISCONSIN...AND THIS MAY CONTINUE TO DEVELOP AND BECOME
STRONGER INTO THE AFTERNOON.
MADISON WOULD SEE BEST SHOT OF THIS BETWEEN 18Z AND 21Z
SATURDAY...AND THE EASTERN SITES BETWEEN 20Z SATURDAY AND 00Z
SUNDAY. IFR VISIBILITIES AND MVFR CEILINGS WOULD BE POSSIBLE IN
ANY STORMS...AS WELL AS LARGE HAIL AND STRONG WINDS.
VFR CONDITIONS ARE EXPECTED OTHERWISE THIS AFTERNOON INTO SUNDAY.
MODERATE SOUTH/SOUTHWEST WINDS ARE EXPECTED AT MADISON AND
WAUKESHA...WITH SOUTH/SOUTHEAST WINDS AT MILWAUKEE AND KENOSHA.
WINDS WILL SHIFT TO THE WEST NORTHWEST LATER TONIGHT AFTER COLD
FRONT MOVES THROUGH THE AREA...REMAINING SO ON SUNDAY. SOME
MIDDLE TO HIGH CLOUDS MAY LINGER LATER TONIGHT INTO SUNDAY.
&&
.MARINE...
SOUTH/SOUTHEAST WINDS MAY GUST TO AROUND 20 KNOTS THIS AFTERNOON.
NOT EXPECTING SMALL CRAFT ADVISORY LEVEL WAVES OR GUSTS AT THIS
TIME.
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT SAT JUL 18 2015/
SHORT TERM...
TODAY AND TONIGHT- CONFIDENCE...MEDIUM.
AN ACTIVE WEATHER PATTERN IS EXPECTED FOR TODAY WITH THREE MAIN
FEATURES OF CONCERN.
THE FIRST BEING WITH THE CURRENT MCS ROLLING INTO WESTERN WISCONSIN
WHERE THERE IS A LONG HISTORY OF DAMAGING WINDS ASSOCIATED WITH
IT. THE MAIN UNCERTAINTY IS WITH HOW LONG IT WILL REMAIN AT SEVERE
LEVELS AS IT STARTS TO OUTRUN SOME OF THE BETTER LOW LEVEL
MOISTURE TRANSPORT WHICH IS ANGLED UP TOWARD SOUTHERN MINNESOTA.
18.08Z RAP ANALYSIS SHOWS A HIGHLY UNSTABLE ENVIRONMENT SITUATED
FROM SOUTHEAST MINNESOTA DOWN INTO SOUTHWEST WISCONSIN WHERE 0-3KM
MUCAPE IS AROUND 4000 J/KG. CURRENTLY...THE STRONGEST PART OF THE
LINE IS IN NORTHERN WISCONSIN WHERE THE MCV IS ALONG WITH A BETTER
REAR INFLOW JET...BUT AM EXPECTING THE SOUTHERN PORTION OF THE
LINE TO BE MAINTAINED AND RIDE ALONG THE INSTABILITY GRADIENT
THROUGH SOUTHERN WISCONSIN THIS MORNING. WHETHER IT WILL BE SEVERE
OR NOT IS UNCERTAIN AS IT WILL BE LEAVING THE BETTER LOW LEVEL
MOISTURE TRANSPORT CHANNEL. TRENDS WILL CONTINUE TO BE MONITORED.
CLOUD COVER AND HOW FAST THE MCS MOVES OUT OF THE REGION PLAYS INTO
HOW HOT CONDITIONS WILL BE TODAY. THERE CURRENTLY IS AN EXPANSIVE
UPPER LEVEL CLOUD DECK BLOWING OFF OF THE MCS WHICH COULD SLOW HOW
FAST TEMPERATURES RISE THIS MORNING...PARTICULARLY IF WE HAVE SOME
RAIN MOVE THROUGH. STRONG SOUTHERLY LOW LEVEL FLOW IS EXPECTED TO
HELP CLEAR CONDITIONS OUT GOING INTO THIS AFTERNOON WHICH SHOULD
ALLOW TEMPERATURES TO RISE UP TO 90F OR ABOVE. SURFACE DEW POINTS
ARE ALREADY IN THE LOW 70S WITH THE AIR MASS TO THE SOUTH SHOWING
DEW POINTS IN THE MID TO UPPER 70S. THE EXPECTED COMBINATION OF
TEMPERATURES IN THE 90S AND DEW POINTS IN THE 70S ARE EXPECTED TO
PUSH HEAT INDICES INTO THE 100-104 DEGREE RANGE TODAY ACROSS MUCH OF
THE REGION. FDL AND WASHINGTON COUNTIES LOOK TO BE JUST AS WARM AS
COUNTIES TO THE WEST...SO HAVE ADDED THEM TO THE ADVISORY.
THE FOCUS THEN TURNS TO THE SEVERE POTENTIAL FOR THIS AFTERNOON AND
EVENING AS THE ENVIRONMENT RECHARGES AFTER THE MCS CLEARS. 18.00Z
NAM/GFS/RAP SOUNDINGS ALL SHOW A HIGHLY UNSTABLE/FAT CAPE PROFILE
AHEAD OF A COLD FRONT. THERE DOES APPEAR TO BE SOME WIND SHEAR AS
WELL...MAINLY IN THE LOWEST 3KM...BUT IT DOES EXTEND TO THE TOP
PORTIONS OF THE SOUNDING WHERE AN UPPER LEVEL JET STREAK WILL BE
PROPAGATING EAST INTO THE REGION. LARGE HAIL AND DAMAGING WINDS
LOOK TO BE THE MAIN THREATS DUE TO THE HIGH INSTABILITY/0-3KM
SHEAR...BUT THERE COULD BE A BOUNDARY LEFT OVER FROM THIS MORNINGS
MCS WHICH COULD BE A FOCUS FOR TORNADO DEVELOPMENT. 0-1KM SHEAR
WOULD LIKELY BE MAXIMIZED ALONG THIS BOUNDARY IF THE SOUTHERLY LOW
LEVEL FLOW DOES NOT WIPE IT OUT OR PUSH IT BACK TO THE NORTH.
SOUNDINGS ALSO ARE NOT LOOKING AS CAPPED AS PREVIOUSLY THOUGHT...SO
CONVECTION MAY INITIATE A BIT EARLIER IN THE AFTERNOON THAN
TYPICALLY WOULD OCCUR. THE MAIN WINDOW FOR SEVERE WEATHER APPEARS
TO BE FROM THIS AFTERNOON INTO THE EARLY EVENING HOURS.
SUNDAY... FORECAST CONFIDENCE HIGH.
THE COLD FRONT WILL LIKELY CLEAR SOUTHEAST WI BY MID SUNDAY MORNING.
IT IS A SMALL CHANCE... BUT THUNDERSTORMS COULD EITHER BE ONGOING OR
TRIGGERED BY THE FRONTAL PASSAGE AS IT MOVES THROUGH SOUTHERN WI
SUNDAY MORNING.
PLAN ON QUIET AND MORE COMFORTABLE WEATHER LATER SUNDAY AFTERNOON
AND NIGHT BEHIND THE FRONT. HIGH TEMPS WILL BE COOLER THAN THE
PREVIOUS TWO DAYS... ONLY IN THE LOWER 80S. DEWPOINTS WILL BE
STEADILY FALLING THROUGH THE AFTERNOON. WINDS WILL BE A LITTLE
BREEZY OUT OF THE NORTHWEST SUNDAY AFTERNOON.
LONG TERM...
MONDAY... FORECAST CONFIDENCE MEDIUM.
THE ECMWF AND GFS ARE NOW BRINGING CHANCES FOR SHOWERS AND
THUNDERSTORMS INTO CENTRAL AND SOUTHERN WI MONDAY AFTERNOON AND
NIGHT. THIS IS DUE TO A SHORTWAVE TROUGH AND RIGHT ENTRANCE REGION
OF AN UPPER JET. A COLD FRONT WILL SLIDE SOUTH THROUGH WI LATE
MONDAY NIGHT. THESE FEATURES ARRIVE EARLIER THAN PREVIOUS FORECASTS.
TUESDAY THROUGH FRIDAY... FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE WILL SET UP OVER THE GREAT LAKES REGION FOR MUCH OF
NEXT WEEK. DRY AIR IN PLACE WILL MAKE IT DIFFICULT FOR ANY
SHORTWAVES CROSSING THE AREA TO PRODUCE PRECIP. THE GFS AND ECMWF HAVE
BACKED OFF ON QPF FOR SOUTHERN WI ON WED THROUGH FRI. EXPECT POPS
TO BE CUT BACK IN LATER FORECASTS. THE NEXT REAL CHANCE FOR PRECIP
NOW LOOKS LIKE SATURDAY.
TEMPERATURES WILL REMAIN AROUND NORMAL WITH HIGHS AROUND 80.
AVIATION/12Z TAFS/...
THE MAIN FOCUS AT THE TAF SITES IS WITH TWO POSSIBLE ROUNDS OF
CONVECTION...ONE POSSIBLY COMING THIS MORNING WITH ANOTHER ROUND
POSSIBLE THIS AFTERNOON/EVENING. A LINE OF STORMS CURRENTLY IN WEST
CENTRAL WISCONSIN IS EXPECTED TO TRACK EAST SOUTHEAST THIS MORNING
AND COULD ROLL THROUGH THE REGION AND BRING SOME STRONG WINDS AND
LOW VISIBILITIES ALONG WITH IT. AFTER THAT SYSTEM MOVES
THROUGH...SOUTHERLY WINDS WILL PICK UP DURING THE DAY AS A HOT AND
HUMID AIR MASS CREATES A VERY UNSTABLE ATMOSPHERE FOR THIS AFTERNOON
AND EVENING. ANOTHER ROUND OF STORMS SHOULD DEVELOP AHEAD OF A COLD
FRONT WHICH WILL PUSH THROUGH THIS EVENING. STRONG WINDS AND LOW
VISIBILITY WILL AGAIN BE POSSIBLE WITH THIS ROUND OF STORMS.
MARINE...
TWO ROUNDS OF STORMS MAY AFFECT THE NEARSHORE WATERS OF LAKE
MICHIGAN THIS MORNING AND THEN AGAIN THIS AFTERNOON AND EARLY
EVENING. WINDS WILL BE ON THE INCREASE INTO THIS AFTERNOON OUT OF
THE SOUTH WITH SOME GUSTS POSSIBLY REACHING THE 20 TO 25 KT RANGE.
A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT AND BRING WINDS
AROUND TO THE WEST NORTHWEST THROUGH THE REST OF THE WEEKEND.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR WIZ046-047-051-
056>059-062>072.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...HALBACH
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1238 PM MDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1058 AM MDT SAT JUL 18 2015
FORECAST PRETTY WELL ON TRACK FOR TODAY. MADE SOME MINOR
ADJUSTMENTS TO DECREASE CLOUD COVER SOMEWHAT THIS MORNING AND
EARLY AFTERNOON IN THE EASTERN FORECAST AREA. THE OTHER SMALL
CHANGE WAS TO INCREASE CHANCES FOR THUNDERSTORMS IN FAR SOUTHEAST
WYOMING AND INTO THE NEBRASKA PANHANDLE. INCREASING CONFIDENCE FOR
THE DEVELOPMENT OF THUNDERSTORMS OVER THE HIGHER TERRAIN OF
SOUTHEAST WYOMING BY EARLY THIS AFTERNOON WITH THUNDERSTORMS
INCREASING IN COVERAGE WHILE QUICKLY MOVING EASTWARD.
NUMERICAL MODELS DO HAVE SUBSTANTIAL DIFFERENCES IN THE
PROGRESSION OF THUNDERSTORM ACTIVITY TODAY. TENDED TO LEAN TOWARD
THE HRRR WITH THE FASTER TIMING. THE MAIN REASONS FOR GOING CLOSER
TO THE HRRR IS DUE TO THE STRONG WESTERLY FLOW ALOFT. CAPE VALUES
AROUND 1500 J/KG WILL NOT SUPPORT UPDRAFTS STRONG ENOUGH TO
OVERCOME THE OVERALL SHEAR...SUCH THAT STORMS SHOULD BECOME
OUTFLOW DOMINATE AND MOVE RAPIDLY TO THE EAST. ALTHOUGH THE FIRST
FEW THUNDERSTORMS MAY HAVE SOME SUPERCELL CHARACTERISTICS WITH
LARGE HAIL POSSIBLE...MORE CONCERNED ABOUT THE WIND THREAT TODAY.
STORM MOVEMENT SHOULD BE AROUND 40 MPH AND WHEN COMBINED WITH
STORM RELATIVE WINDS...WOULD NOT BE SURPRISED TO SEE WINDS TO
AROUND 70 MPH INTO THE PLAINS.
MAY SEE A LINE OF THUNDERSTORMS DEVELOP WITH A SQUALL LINE MOVING
OUT OF FAR SOUTHEAST WYOMING INTO THE NEBRASKA BY EARLY THIS
EVENING. THERE IS STILL SOME QUESTION AS TO WHERE A NEARLY
STATIONARY BOUNDARY WILL BE LOCATED THIS AFTERNOON. CURRENTLY IT
LOOKS LIKE IT WILL BE LINED UP ALONG OR JUST NORTH OF INTERSTATE
80 BETWEEN CHEYENNE AND SIDNEY. ALTHOUGH WINDS LOOK TO BE THE MAIN
SEVERE CONCERN TODAY...A SUPERCELL COULD OCCUR WITHIN OR AHEAD OF
ANY SQUALL LINE ON THE STATIONARY BOUNDARY. ANY SUPERCELL WOULD
HAVE AN INCREASED HAIL POTENTIAL AND A REMOTE POTENTIAL FOR
TORNADIC DEVELOPMENT. LCLS ALONG THE FRONT WILL BE BETWEEN
AROUND 4000 FEET SUCH THAT A TORNADO IS POSSIBLE BUT OVERALL
THREAT IS MINIMAL.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 237 AM MDT SAT JUL 18 2015
PREDAWN WATER VAPOR SATELLITE AND OBJECTIVE UPPER AIR ANALYSIS SHOWS
A VIGOROUS MID LEVEL SHORTWAVE TROUGH NOW TRACKING ACROSS EASTERN MT
INTO WESTERN ND. FARTHER WEST...A SEPARATE DISTURBANCE WAS DRIFTING
SOUTHEAST INTO THE GREAT BASIN. MOIST SOUTHWESTERLY FLOW ALOFT WILL
BECOME ESTABLISHED LATER TODAY ACROSS THE CENTRAL ROCKIES WITH GOOD
MONSOONAL MOISTURE STREAMING OVER THE CWA PER RECENT H7-H3 RH PROGS
FROM MOST GUIDANCE. RECENT SURFACE ANALYSIS DATA SHOWS A WEAK COOL
FRONT HAS ALREADY MOVED SOUTH INTO CO...SO EXPECT TEMPERATURES TODAY
TO BE COOLER THAN PREVIOUS DAYS. SFC FLOW SHOULD EVENTUALLY BEGIN TO
TURN MORE UPSLOPE ALONG/EAST OF THE LARAMIE RANGE IN THE AFTN...WITH
LLVL MOISTURE RAPIDLY INCREASING AS A RESULT. IN ADDITION...THE GFS
SHOWS A 100 KT H25 JET STREAK LIFTING INTO CENTRAL WY BY 00Z WITH A
LARGE PART OF THE CWA IN THE FAVORED RRQ. SCATTERED/NUMEROUS SHOWERS
AND TSTMS SHOULD BE THE NET RESULT. TENDENCY IS TO LEAN MORE TOWARD
THE NAM GIVEN THE RECENT DRY BIAS OF THE GFS WITH SURFACE DEW POINTS
5-10 DEGREES TOO LOW IN THE AFTN. DEW POINTS IN THE LOW-MID 50S AND
SURFACE TEMPS IN THE MID 70S YIELD SBCAPE OVER 1500 J/KG AS FAR WEST
AS CHEYENNE...WHICH COMBINED WITH 0 TO 6 KM VERTICAL SHEAR EXCEEDING
50 KTS WOULD SUGGEST SOME SEVERE POTENTIAL. PRIMARY AREA OF CONCERN
WOULD BE THE I80 CORRIDOR BETWEEN CYS-SNY. THE 06Z SPC DAY 1 OUTLOOK
HAS THIS REGION HIGHLIGHTED IN A SLGT RISK. INCREASING LLVL THETA-E
ADVECTION BETWEEN 00Z-06Z WOULD SUGGEST CONVECTION BECOMING FOCUSED
OVER THE SOUTHERN PANHANDLE...WITH THE THREAT TRANSITIONING TO VERY
HEAVY RAIN GIVEN NAM PWATS BETWEEN 1.5 AND 2.0 INCHES.
WHILE MODELS STILL DIFFER IN THE TIMING...THE GENERAL CONSENSUS IS
FOR THE AFOREMENTIONED TROUGH AXIS TO TRANSLATE EASTWARD ACROSS THE
CWA ON SUN. A PLUME OF MONSOONAL MOISTURE WILL REMAIN IN PLACE...SO
AT LEAST ISOLATED AFTERNOON CONVECTION CAN BE EXPECTED. THE 06Z NAM
IS COMING IN MORE BULLISH WITH QPF FIELDS...LIKELY DUE TO ENHANCED
LLVL CONVERGENCE VIA LEE TROUGHING AND LINGERING JET SUPPORT OVER
OUR NORTHERN ZONES. WE MAY NEED TO LOOK INTO BUMPING POPS INTO THE
SCATTERED CATEGORY IF THIS TREND CONTINUES. THIS COULD BE ANOTHER
OPPORTUNITY FOR STRONG/SEVERE STORMS EAST OF THE SFC TROUGH...IF
CLOUD COVER DOES NOT INHIBIT INSTABILITY. SPCS MARGINAL RISK LOOKS
GOOD FOR NOW. FOR MONDAY...THE MODELS ARE STILL HAVING A VERY HARD
TIME HANDLING SHORTWAVES WITHIN AN ACTIVE NORTHERN STREAM. GFS/ECM
CONTINUE TO ADVERTISE THE BATTLE OF TROUGH VS RIDGE...SO CONTINUED
TO KEEP LOW-END POPS OVER THE MOUNTAINS UNTIL WE CAN RESOLVE FINE
SCALE DETAILS.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 310 AM MDT SAT JUL 18 2015
MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO STRUGGLE WITH
SHORTWAVE ENERGY MOVING EASTWARD EMBEDDED IN THE MEAN WESTERLY
FLOW ALOFT. THE GFS IS NOW MUCH MORE PROGRESSIVE WITH THE SECOND
SHORTWAVE FORECAST TO MOVE ACROSS WYOMING ON TUESDAY...WITH
ANOTHER ROUND OF SCATTERED SHOWERS AND TSTORMS MAINLY FOR THE
SOUTHERN TWO THIRDS OF THE FORECAST AREA. THE ECMWF AND GEM ARE
NEARLY 18 HOURS LATER WITH THIS SHORTWAVE AND DO NOT SHOW MUCH IN
THE WAY OF FORCING TUESDAY AND TUESDAY EVENING. THE ECMWF SHOWS
THIS SHORTWAVE CLIPPING THE AREA ON WEDNESDAY HOWEVER AS THE UPPER
LEVEL FLOW BEGINS TO VEER INTO THE NORTHWEST BEHIND THE WEAK UPPER
LEVEL TROUGH. KEPT POP BETWEEN 20 T0 40 PERCENT BOTH
DAYS...ESPECIALLY ALONG AND JUST NORTH OF THE I80 CORRIDOR. AT
THIS POINT...VERY DIFFICULT TO GET SPECIFIC FOR THE MIDDLE OF NEXT
WEEK. TEMPERATURES SHOULD TREND WARMER BY WEDNESDAY...BUT HIGHS
WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF THE YEAR.
BY THE END OF THE WEEK...MODELS SHOW A TYPICAL JULY WEATHER
PATTERN WITH VERY WARM TEMPERATURES AND RIDGING ALOFT EXTENDING
NORTHWARD ACROSS THE CENTRAL ROCKY MOUNTAINS. HIGH TEMPERATURES
IN THE MID 80S TO MID 90S ARE EXPECTED THROUGH THURSDAY AND
FRIDAY. CHANCES OF THUNDERSTORMS ARE UNCLEAR AT THIS TIME SINCE
MODELS IN THE LONG RANGE HAVE STRUGGLED WITH BOUNDARY LAYER
MOISTURE PROFILES THIS SUMMER. CAN NOT RULE OUT ISOLATED
THUNDERSTORMS ACROSS THE MOUNTAINS AND HIGH PLAINS AT THE VERY
LEAST...MAINLY DUE TO TRENDS THE LAST FEW MONTHS. THE GFS
ESPECIALLY HAS HAD THE TENDENCY TO SHOW A VERY DRY BOUNDARY LAYER
IN SOUTHWEST FLOW...SO WILL NOT PUT MUCH FAITH IN THIS SOLUTION AT
THIS TIME. DID INCREASE POP A BIT...BUT KEPT VALUES BELOW 15
PERCENT FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1224 PM MDT SAT JUL 18 2015
MAIN FORECAST CHALLENGE THIS TAF CYCLE IS TRYING TO PIN DOWN
THUNDERSTORM TIMING AND EXTENT THIS AFTERNOON. LATEST MODELS SHOW
CONVECTION INITIATING IN THE VICINTY OF KLAR AND KCYS BETWEEN
19-20Z WITH ADDL DEVELOPMENT THEREAFTER AS STORM MERGE ACROSS THE
ERN PLAINS. FOR NOW...CONFIDENCE IS THE GREATEST IN SEEING
THUNDERSTORM ACTIVITY AT KCYS SO INTRODUCED A TEMPO GROUP THERE
21-01Z. ELSEWHERE...KEPT VCTS MENTION AT MOST OTHER AIRFIELDS THIS
AFTERNOON AND EVEN AS THE ANTICIPATED THUNDERSTORM COMPLEX SHIFTS
EAST INTO WRN NEBRASKA. CONVECTION WILL DEPART W-E DURING THE
EVENING HOURS AND BE OUT OF THE AREA 04-06Z. THE OTHER CHANGE TO
THE FORECAST WAS TO INTRODUCE FOG POTENTIAL AT KCYS...KBFF AND
KSNY 10-15Z. CONFIDENCE IS NOT ALL THAT HIGH IN THIS
OCCURRING...BUT WANTED TO STEER THE TAFS THAT DIRECTION.
&&
.FIRE WEATHER...
ISSUED AT 237 AM MDT SAT JUL 18 2015
MINIMAL FIRE WEATHER CONCERNS. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE TODAY AND TONIGHT...YIELDING A GOOD CHANCE FOR WETTING
RAINS OVER MUCH OF THE AREA. GUSTY/ERRATIC WINDS COULD ACCOMPANY
SOME THUNDERSTORMS. OVERALL CONDITIONS SHOULD REMAIN NON-CRITICAL
THROUGH THE WEEKEND WITH AFTERNOON RH VALUES ABOVE 20 PCT. A TREND
TOWARD WARMER AND DRIER CONDITIONS IS EXPECTED NEXT WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...CAH
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1058 AM MDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 1058 AM MDT SAT JUL 18 2015
FORECAST PRETTY WELL ON TRACK FOR TODAY. MADE SOME MINOR
ADJUSTMENTS TO DECREASE CLOUD COVER SOMEWHAT THIS MORNING AND
EARLY AFTERNOON IN THE EASTERN FORECAST AREA. THE OTHER SMALL
CHANGE WAS TO INCREASE CHANCES FOR THUNDERSTORMS IN FAR SOUTHEAST
WYOMING AND INTO THE NEBRASKA PANHANDLE. INCREASING CONFIDENCE FOR
THE DEVELOPMENT OF THUNDERSTORMS OVER THE HIGHER TERRAIN OF
SOUTHEAST WYOMING BY EARLY THIS AFTERNOON WITH THUNDERSTORMS
INCREASING IN COVERAGE WHILE QUICKLY MOVING EASTWARD.
NUMERICAL MODELS DO HAVE SUBSTANTIAL DIFFERENCES IN THE
PROGRESSION OF THUNDERSTORM ACTIVITY TODAY. TENDED TO LEAN TOWARD
THE HRRR WITH THE FASTER TIMING. THE MAIN REASONS FOR GOING CLOSER
TO THE HRRR IS DUE TO THE STRONG WESTERLY FLOW ALOFT. CAPE VALUES
AROUND 1500 J/KG WILL NOT SUPPORT UPDRAFTS STRONG ENOUGH TO
OVERCOME THE OVERALL SHEAR...SUCH THAT STORMS SHOULD BECOME
OUTFLOW DOMINATE AND MOVE RAPIDLY TO THE EAST. ALTHOUGH THE FIRST
FEW THUNDERSTORMS MAY HAVE SOME SUPERCELL CHARACTERISTICS WITH
LARGE HAIL POSSIBLE...MORE CONCERNED ABOUT THE WIND THREAT TODAY.
STORM MOVEMENT SHOULD BE AROUND 40 MPH AND WHEN COMBINED WITH
STORM RELATIVE WINDS...WOULD NOT BE SURPRISED TO SEE WINDS TO
AROUND 70 MPH INTO THE PLAINS.
MAY SEE A LINE OF THUNDERSTORMS DEVELOP WITH A SQUALL LINE MOVING
OUT OF FAR SOUTHEAST WYOMING INTO THE NEBRASKA BY EARLY THIS
EVENING. THERE IS STILL SOME QUESTION AS TO WHERE A NEARLY
STATIONARY BOUNDARY WILL BE LOCATED THIS AFTERNOON. CURRENTLY IT
LOOKS LIKE IT WILL BE LINED UP ALONG OR JUST NORTH OF INTERSTATE
80 BETWEEN CHEYENNE AND SIDNEY. ALTHOUGH WINDS LOOK TO BE THE MAIN
SEVERE CONCERN TODAY...A SUPERCELL COULD OCCUR WITHIN OR AHEAD OF
ANY SQUALL LINE ON THE STATIONARY BOUNDARY. ANY SUPERCELL WOULD
HAVE AN INCREASED HAIL POTENTIAL AND A REMOTE POTENTIAL FOR
TORNADIC DEVELOPMENT. LCLS ALONG THE FRONT WILL BE BETWEEN
AROUND 4000 FEET SUCH THAT A TORNADO IS POSSIBLE BUT OVERALL
THREAT IS MINIMAL.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 237 AM MDT SAT JUL 18 2015
PREDAWN WATER VAPOR SATELLITE AND OBJECTIVE UPPER AIR ANALYSIS SHOWS
A VIGOROUS MID LEVEL SHORTWAVE TROUGH NOW TRACKING ACROSS EASTERN MT
INTO WESTERN ND. FARTHER WEST...A SEPARATE DISTURBANCE WAS DRIFTING
SOUTHEAST INTO THE GREAT BASIN. MOIST SOUTHWESTERLY FLOW ALOFT WILL
BECOME ESTABLISHED LATER TODAY ACROSS THE CENTRAL ROCKIES WITH GOOD
MONSOONAL MOISTURE STREAMING OVER THE CWA PER RECENT H7-H3 RH PROGS
FROM MOST GUIDANCE. RECENT SURFACE ANALYSIS DATA SHOWS A WEAK COOL
FRONT HAS ALREADY MOVED SOUTH INTO CO...SO EXPECT TEMPERATURES TODAY
TO BE COOLER THAN PREVIOUS DAYS. SFC FLOW SHOULD EVENTUALLY BEGIN TO
TURN MORE UPSLOPE ALONG/EAST OF THE LARAMIE RANGE IN THE AFTN...WITH
LLVL MOISTURE RAPIDLY INCREASING AS A RESULT. IN ADDITION...THE GFS
SHOWS A 100 KT H25 JET STREAK LIFTING INTO CENTRAL WY BY 00Z WITH A
LARGE PART OF THE CWA IN THE FAVORED RRQ. SCATTERED/NUMEROUS SHOWERS
AND TSTMS SHOULD BE THE NET RESULT. TENDENCY IS TO LEAN MORE TOWARD
THE NAM GIVEN THE RECENT DRY BIAS OF THE GFS WITH SURFACE DEW POINTS
5-10 DEGREES TOO LOW IN THE AFTN. DEW POINTS IN THE LOW-MID 50S AND
SURFACE TEMPS IN THE MID 70S YIELD SBCAPE OVER 1500 J/KG AS FAR WEST
AS CHEYENNE...WHICH COMBINED WITH 0 TO 6 KM VERTICAL SHEAR EXCEEDING
50 KTS WOULD SUGGEST SOME SEVERE POTENTIAL. PRIMARY AREA OF CONCERN
WOULD BE THE I80 CORRIDOR BETWEEN CYS-SNY. THE 06Z SPC DAY 1 OUTLOOK
HAS THIS REGION HIGHLIGHTED IN A SLGT RISK. INCREASING LLVL THETA-E
ADVECTION BETWEEN 00Z-06Z WOULD SUGGEST CONVECTION BECOMING FOCUSED
OVER THE SOUTHERN PANHANDLE...WITH THE THREAT TRANSITIONING TO VERY
HEAVY RAIN GIVEN NAM PWATS BETWEEN 1.5 AND 2.0 INCHES.
WHILE MODELS STILL DIFFER IN THE TIMING...THE GENERAL CONSENSUS IS
FOR THE AFOREMENTIONED TROUGH AXIS TO TRANSLATE EASTWARD ACROSS THE
CWA ON SUN. A PLUME OF MONSOONAL MOISTURE WILL REMAIN IN PLACE...SO
AT LEAST ISOLATED AFTERNOON CONVECTION CAN BE EXPECTED. THE 06Z NAM
IS COMING IN MORE BULLISH WITH QPF FIELDS...LIKELY DUE TO ENHANCED
LLVL CONVERGENCE VIA LEE TROUGHING AND LINGERING JET SUPPORT OVER
OUR NORTHERN ZONES. WE MAY NEED TO LOOK INTO BUMPING POPS INTO THE
SCATTERED CATEGORY IF THIS TREND CONTINUES. THIS COULD BE ANOTHER
OPPORTUNITY FOR STRONG/SEVERE STORMS EAST OF THE SFC TROUGH...IF
CLOUD COVER DOES NOT INHIBIT INSTABILITY. SPCS MARGINAL RISK LOOKS
GOOD FOR NOW. FOR MONDAY...THE MODELS ARE STILL HAVING A VERY HARD
TIME HANDLING SHORTWAVES WITHIN AN ACTIVE NORTHERN STREAM. GFS/ECM
CONTINUE TO ADVERTISE THE BATTLE OF TROUGH VS RIDGE...SO CONTINUED
TO KEEP LOW-END POPS OVER THE MOUNTAINS UNTIL WE CAN RESOLVE FINE
SCALE DETAILS.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 310 AM MDT SAT JUL 18 2015
MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO STRUGGLE WITH
SHORTWAVE ENERGY MOVING EASTWARD EMBEDDED IN THE MEAN WESTERLY
FLOW ALOFT. THE GFS IS NOW MUCH MORE PROGRESSIVE WITH THE SECOND
SHORTWAVE FORECAST TO MOVE ACROSS WYOMING ON TUESDAY...WITH
ANOTHER ROUND OF SCATTERED SHOWERS AND TSTORMS MAINLY FOR THE
SOUTHERN TWO THIRDS OF THE FORECAST AREA. THE ECMWF AND GEM ARE
NEARLY 18 HOURS LATER WITH THIS SHORTWAVE AND DO NOT SHOW MUCH IN
THE WAY OF FORCING TUESDAY AND TUESDAY EVENING. THE ECMWF SHOWS
THIS SHORTWAVE CLIPPING THE AREA ON WEDNESDAY HOWEVER AS THE UPPER
LEVEL FLOW BEGINS TO VEER INTO THE NORTHWEST BEHIND THE WEAK UPPER
LEVEL TROUGH. KEPT POP BETWEEN 20 T0 40 PERCENT BOTH
DAYS...ESPECIALLY ALONG AND JUST NORTH OF THE I80 CORRIDOR. AT
THIS POINT...VERY DIFFICULT TO GET SPECIFIC FOR THE MIDDLE OF NEXT
WEEK. TEMPERATURES SHOULD TREND WARMER BY WEDNESDAY...BUT HIGHS
WILL BE NEAR OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF THE YEAR.
BY THE END OF THE WEEK...MODELS SHOW A TYPICAL JULY WEATHER
PATTERN WITH VERY WARM TEMPERATURES AND RIDGING ALOFT EXTENDING
NORTHWARD ACROSS THE CENTRAL ROCKY MOUNTAINS. HIGH TEMPERATURES
IN THE MID 80S TO MID 90S ARE EXPECTED THROUGH THURSDAY AND
FRIDAY. CHANCES OF THUNDERSTORMS ARE UNCLEAR AT THIS TIME SINCE
MODELS IN THE LONG RANGE HAVE STRUGGLED WITH BOUNDARY LAYER
MOISTURE PROFILES THIS SUMMER. CAN NOT RULE OUT ISOLATED
THUNDERSTORMS ACROSS THE MOUNTAINS AND HIGH PLAINS AT THE VERY
LEAST...MAINLY DUE TO TRENDS THE LAST FEW MONTHS. THE GFS
ESPECIALLY HAS HAD THE TENDENCY TO SHOW A VERY DRY BOUNDARY LAYER
IN SOUTHWEST FLOW...SO WILL NOT PUT MUCH FAITH IN THIS SOLUTION AT
THIS TIME. DID INCREASE POP A BIT...BUT KEPT VALUES BELOW 15
PERCENT FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH SATURDAY NIGHT)
ISSUED AT 237 AM MDT SAT JUL 18 2015
VFR CONDITIONS ACROSS THE AREA EARLY THIS MORNING...BUT CAN NOT
RULE OUT THE POSSIBILITY OF SOME LOW STRATUS AND PATCHY FOG ACROSS
WESTERN NEBRASKA THROUGH SUNRISE. KEPT MVFR CONDITIONS FROM KSNY
NORTHWARD TO KBFF AND KAIA UNTIL 15Z. OTHERWISE...WINDS WILL SHIFT
INTO THE EAST OR SOUTHEAST TODAY AS A DISTURBANCE ALOFT MOVES
ACROSS THE AREA. THIS DISTURBANCE COMBINED WITH LLVL MOISTURE WILL
RESULT IN SCATTERED SHOWERS AND TSTORMS BY THIS AFTERNOON ACROSS
SOUTHEAST WYOMING AND WESTERN NEBRASKA. BRIEF MVFR TO NEAR IFR
CONDITIONS ARE POSSIBLE IN AND NEAR THE STRONGEST TSTORMS THROUGH
THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 237 AM MDT SAT JUL 18 2015
MINIMAL FIRE WEATHER CONCERNS. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE TODAY AND TONIGHT...YIELDING A GOOD CHANCE FOR WETTING
RAINS OVER MUCH OF THE AREA. GUSTY/ERRATIC WINDS COULD ACCOMPANY
SOME THUNDERSTORMS. OVERALL CONDITIONS SHOULD REMAIN NON-CRITICAL
THROUGH THE WEEKEND WITH AFTERNOON RH VALUES ABOVE 20 PCT. A TREND
TOWARD WARMER AND DRIER CONDITIONS IS EXPECTED NEXT WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH